bims-tucedo Biomed News
on Tumor cell dormancy
Issue of 2022‒03‒13
35 papers selected by
Isabel Puig Borreil
Vall d’Hebron Institute of Oncology

  1. Elife. 2022 Mar 08. pii: e73150. [Epub ahead of print]11
      Mechanical stress is known to fuel several hallmarks of cancer, ranging from genome instability to uncontrolled proliferation or invasion. Cancer cells are constantly challenged by mechanical stresses not only in the primary tumour but also during metastasis. However, this latter has seldom been studied with regards to mechanobiology, in particular resistance to anoikis, a cell death programme triggered by loss of cell adhesion. Here, we show in vitro that migrating breast cancer cells develop resistance to anoikis following their passage through microporous membranes mimicking confined migration (CM), a mechanical constriction that cancer cells encounter during metastasis. This CM-induced resistance was mediated by Inhibitory of Apoptosis Proteins, and sensitivity to anoikis could be restored after their inhibition using second mitochondria-derived activator of caspase (SMAC) mimetics. Anoikis-resistant mechanically stressed cancer cells displayed enhanced cell motility and evasion from natural killer cell-mediated immune surveillance, as well as a marked advantage to form lung metastatic lesions in mice. Our findings reveal that CM increases the metastatic potential of breast cancer cells.
    Keywords:  IAP; anoikis; cancer biology; caspases; cell biology; confinement; human; mechanobiology; metastasis; mouse
  2. Nat Commun. 2022 Mar 07. 13(1): 1199
      Deregulation of the BCL-2 family interaction network ensures cancer resistance to apoptosis and is a major challenge to current treatments. Cancer cells commonly evade apoptosis through upregulation of the BCL-2 anti-apoptotic proteins; however, more resistant cancers also downregulate or inactivate pro-apoptotic proteins to suppress apoptosis. Here, we find that apoptosis resistance in a diverse panel of solid and hematological malignancies is mediated by both overexpression of BCL-XL and an unprimed apoptotic state, limiting direct and indirect activation mechanisms of pro-apoptotic BAX. Both survival mechanisms can be overcome by the combination of an orally bioavailable BAX activator, BTSA1.2 with Navitoclax. The combination demonstrates synergistic efficacy in apoptosis-resistant cancer cells, xenografts, and patient-derived tumors while sparing healthy tissues. Additionally, functional assays and genomic markers are identified to predict sensitive tumors to the combination treatment. These findings advance the understanding of apoptosis resistance mechanisms and demonstrate a novel therapeutic strategy for cancer treatment.
  3. Cancer Res. 2022 Mar 08. pii: canres.1823.2021. [Epub ahead of print]
      Triple-negative breast cancer (TNBC) is the most aggressive and deadly subtype of breast cancer, accounting for 30,000 cases annually in the US. While there are several clinical trials ongoing to identify new agents to treat TNBC, the majority of TNBC patients are treated with anthracycline- or taxane-based chemotherapies in the neoadjuvant setting, followed by surgical resection and adjuvant chemotherapy. While many patients respond well to this approach, as many as 25% will suffer local or metastatic recurrence within five years. Understanding the mechanisms that drive recurrence after chemotherapy treatment is critical to improving survival for patients with TNBC. It is well-established that the extracellular matrix, which provides structure and support to tissues, is a major driver of tumor growth, local invasion and dissemination of cancer cells to distant metastatic sites. In the present study, we show that decellularized extracellular matrix (dECM) obtained from chemotherapy-treated mice increases motility of treatment-naïve breast cancer cells compared to vehicle-treated dECM. Tandem-mass-tag proteomics revealed that anthracycline- and taxane-based chemotherapies induce drug-specific changes in tumor ECM composition. The basement membrane protein collagen IV was significantly upregulated in the ECM of chemotherapy-treated mice and patients treated with neoadjuvant chemotherapy. Collagen IV drove invasion via activation of Src and focal adhesion kinase signaling downstream of integrin α1 and α2, and inhibition of collagen IV-driven signaling decreased motility in chemotherapy-treated dECM. These studies provide a novel mechanism by which chemotherapy may induce metastasis via its effects on ECM composition.
  4. Oncogene. 2022 Mar 09.
      The tumor stroma of pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant and heterogeneous population of cancer-associated fibroblasts (CAFs), which are critically involved in chemoresistance. However, the underlying mechanism of CAFs in chemoresistance is unclear. Here, we show that CAFR, a CAF subset derived from platinum-resistant PDAC patients, assumes an iCAF phenotype and produces more IL8 than CAFS isolated from platinum-sensitive PDAC patients. CAFR-derived IL8 promotes oxaliplatin chemoresistance in PDAC. Based on long noncoding RNA (lncRNA) profiling in tumor cells incubated with CAF-CM, we found that UPK1A-AS1, whose expression is directly induced by IL8/NF-kappa B signaling, functions as a chemoresistance-promoting lncRNA and is critical for active IL8-induced oxaliplatin resistance. Impressively, blocking the activation of UPK1A-AS1 expression increases the oxaliplatin sensitivity of tumor cells in vivo. Mechanistically, UPK1A-AS1 strengthens the interaction between Ku70 and Ku80 to facilitate nonhomologous end joining (NHEJ), thereby enhancing DNA double-strand break (DSB) repair. Clinically, UPK1A-AS1 expression is positively correlated with IL8 expression, a poor chemotherapeutic response and a shorter progression-free survival (PFS) time in advanced PDAC patients. Collectively, our study reveals a lncRNA-mediated mechanism of CAF-derived paracrine IL8-dependent oxaliplatin resistance and highlights UPK1A-AS1 as a potential therapeutic target.
  5. Cancer Res. 2022 Mar 03. pii: canres.CAN-21-3917-A.2021. [Epub ahead of print]
      Constitutive or acquired resistance is a major problem limiting the clinical success of anticancer immunotherapies targeting the PD-1/PD-L1 interaction. Here, we report that the molecular chaperone HSP90 is a key mediator of IFNγ-induced adaptive immune resistance. An unbiased screen of 17 cancer cell lines or primary cancer cells identified novel metabolic agents, especially HSP90 inhibitors, that blocked the upregulation of immune checkpoints (IDO1 and PD-L1) induced by IFNγ. Subsequent quantitative mass spectrometry combined with functional rescue analysis revealed that IFNγ-induced immune checkpoint expression requires increased protein stability of the transcription factor STAT1, mediated by the HSP90-SUGT1 chaperone complex. Expression of dominant-negative HSP90 (D88N) resulted in inhibition of STAT1-mediated IFNγ signaling. The upregulation of IDO1 in cancer cells acted as an immunosuppressive feedback mechanism to limit the proliferation and function of cytotoxic CD8+ T lymphocytes through iron-dependent kynurenine production and subsequent TSPAN5-mediated kynurenine secretion. The effectiveness and safety of combinations of anti-PD-1 immunotherapy with iron chelation or pharmacological inhibitors of HSP90 or IDO1 was confirmed in xenograft, orthotopic, and transgenic mouse models of pancreatic cancer. These findings support the rationale for future clinical trials in which widely used immunotherapies are combined with additional molecules that intercept resistance by iron chelation, IDO1 inhibition, or HSP90 neutralization.
  6. Theranostics. 2022 ;12(5): 2063-2079
      Background: Dietary tyrosine regulating melanoma progression has been well-recognized. However, whether tyrosine-based melanin anabolism contributes to pulmonary and cerebral organotropic colonization of melanoma remains elusive. Furthermore, approaches based on targeting tyrosinase activity to inhibiting multi-organ metastasis of melanoma cells need to be designed and validated. Methods: Patients derived melanoma cells and mouse B16 melanoma cells with different pigmentation were employed in this investigation. Tyrosine content dynamics in tumors and multiple organs during the melanoma progression was monitored, and tyrosine-based melanin synthesis of melanoma cells derived from multi-organ was determined. Additionally, we also adopted RNA-seq, flow cytometry, real-time PCR and composite metastasis mouse model to analyze organotropic colonization and to validate designed therapeutic strategies. Results: B16 melanoma cells with high activity of tyrosinase and sensitivity of tyrosine utilization for melanin synthesis (Tyr-H cells) easily colonized in the lung, while B16 melanoma cells lacking above characteristics (Tyr-L cells) exhibited potent proliferation in the brain. Mechanistically, Tyr-H cells recruited and trained neutrophils and macrophages to establish pulmonary metastatic niche dependent on highly secreted CXCL1 and CXCL2 and an excessive melanosome accumulation-induced cell death. Tyr-L cells enhanced PD-L1 expression in tumor-infiltrated macrophages when they are progressing in the brain. Accordingly, intervention of tyrosinase activity (2-Ethoxybenzamide or hydroquinone) in combination with inhibitors of phagocytosis (GSK343) or chemotaxis (SB225002) suppressed organotropic colonization and significantly improved the survival of melanoma- bearing mice treated with immune checkpoint blockade (PD1 antibody). Conclusions: The heterogeneity of melanoma cells in utilization of tyrosine is associated with organotropic colonization, providing the basis for developing new strategies to combat melanoma.
    Keywords:  Melanoma; immune checkpoint; melanin anabolism; organotropic colonization; tumor heterogeneity
  7. Nat Rev Cancer. 2022 Mar 09.
      Normal cells explore multiple states to survive stresses encountered during development and self-renewal as well as environmental stresses such as starvation, DNA damage, toxins or infection. Cancer cells co-opt normal stress mitigation pathways to survive stresses that accompany tumour initiation, progression, metastasis and immune evasion. Cancer therapies accentuate cancer cell stresses and invoke rapid non-genomic stress mitigation processes that maintain cell viability and thus represent key targetable resistance mechanisms. In this Review, we describe mechanisms by which tumour ecosystems, including cancer cells, immune cells and stroma, adapt to therapeutic stresses and describe three different approaches to exploit stress mitigation processes: (1) interdict stress mitigation to induce cell death; (2) increase stress to induce cellular catastrophe; and (3) exploit emergent vulnerabilities in cancer cells and cells of the tumour microenvironment. We review challenges associated with tumour heterogeneity, prioritizing actionable adaptive responses for optimal therapeutic outcomes, and development of an integrative framework to identify and target vulnerabilities that arise from adaptive responses and engagement of stress mitigation pathways. Finally, we discuss the need to monitor adaptive responses across multiple scales and translation of combination therapies designed to take advantage of adaptive responses and stress mitigation pathways to the clinic.
  8. Cell Rep. 2022 Mar 08. pii: S2211-1247(22)00223-6. [Epub ahead of print]38(10): 110490
      How metastatic cells arise is unclear. Here, we search for the induction of recently characterized pro-metastatic states as a surrogate for the origin of metastasis. Since cell-death-inducing therapies can paradoxically promote metastasis, we ask if such treatments induce pro-metastatic states in human colon cancer cells. We find that post-near-death cells acquire pro-metastatic states (PAMEs) and form distant metastases in vivo. These PAME ("let's go" in Greek) cells exhibit a multifactorial cytokine storm as well as signs of enhanced endoplasmic reticulum (ER) stress and nuclear reprogramming, requiring CXCL8, INSL4, IL32, PERK-CHOP, and NANOG. PAMEs induce neighboring tumor cells to become PAME-induced migratory cells (PIMs): highly migratory cells that re-enact the storm and enhance PAME migration. Metastases are thus proposed to originate from the induction of pro-metastatic states through intrinsic and extrinsic cues in a pro-metastatic tumoral ecosystem, driven by an impending cell-death experience involving ER stress modulation, metastatic reprogramming, and paracrine recruitment via a cytokine storm.
    Keywords:  ER stress; PAME; apoptosis; colon cancer; cytokine storm; metastasis; metastasis-initiating cells; metastatic reprogramming; primary heterogeneity; regulated cell death
  9. Oncogene. 2022 Mar 07.
      The cellular origin of hepatocellular carcinomas (HCC) and the role of Notch1 signalling in HCC initiation are controversial. Herein, we establish Notch1 as a regulator of HCC development and progression. Clinically, high Notch1 expression correlates with enhanced cancer progression, elevated lung metastasis, increased cancer stem cell (CSC)-like cells' gene signature expression, and poor overall survival in HCC patients. Notch1 intracellular domain (N1ICD) overexpression spontaneously transforms rat liver progenitor cells (LPC) into CSC-like cells (WBN1ICD C5) under a selective growth environment, while orthotopic injection of these cells generates liver tumors and spontaneous pulmonary metastasis in an isogenic rat model. Mechanistically, the elevated Notch1 activity increases c-myc expression, which then transcriptionally upregulates VCAM1 expression to activate macrophage dependent HCC transendothelial migration. In vivo, silencing c-myc prohibits the tumorigenicity of WBN1ICD C5 cells, while depletion of VCAM1 reduces spontaneous lung metastasis without affecting primary WBN1ICD C5 orthotopic liver tumor growth. Importantly, depletion of macrophage or blockade of macrophage VCAM1 binding receptor α4β1-integrin reduces the number of WBN1ICD C5 lung nodules in an experimental metastasis model. Overall, our work discovers that the Notch1-c-myc-VCAM1 signaling axis initiates LPC-driven hepatocarcinogenesis and metastasis, providing a preclinical model for HCC study and therapeutic targets for an improved HCC treatment.
  10. J Exp Med. 2022 Apr 04. pii: e20212166. [Epub ahead of print]219(4):
      How to specifically target oncogenic KRAS-driven cancers while sparing normal tissues remains an unmet need in cancer therapy. In this issue of JEM, Jiang et al. (2022. J. Exp. Med. leveraged KRAS-induced iron addiction in cancer cells to design a clever drug delivery approach to enable selective inhibition of KRAS signaling in mutant KRAS tumors but not in normal tissues, offering a new strategy for treating this largely incurable disease.
  11. Nat Commun. 2022 Mar 10. 13(1): 1248
      Microbiota-host interactions play critical roles in colorectal cancer (CRC) progression, however, the underlying mechanisms remain elusive. Here, we uncover that Fusobacterium nucleatum (F. nucleatum) induces a dramatic decline of m6A modifications in CRC cells and patient-derived xenograft (PDX) tissues by downregulation of an m6A methyltransferase METTL3, contributing to inducation of CRC aggressiveness. Mechanistically, we characterized forkhead box D3 (FOXD3) as a transcription factor for METTL3. F. nucleatum activates YAP signaling, inhibits FOXD3 expression, and subsequently reduces METTL3 transcription. Downregulation of METTL3 promotes its target kinesin family member 26B (KIF26B) expression by reducing its m6A levels and diminishing YTHDF2-dependent mRNA degradation, which contributes to F. nucleatum-induced CRC metastasis. Moreover, METTL3 expression is negatively correlated with F. nucleatum and KIF26B levels in CRC tissues. A high expression of KIF26B is also significantly correlated with a shorter survival time of CRC patients. Together, our findings provide insights into modulating human m6A epitranscriptome by gut microbiota, and its significance in CRC progression.
  12. Cell Rep. 2022 Mar 08. pii: S2211-1247(22)00225-X. [Epub ahead of print]38(10): 110492
      Immune checkpoint inhibitor (ICI) therapy is generating remarkable responses in individuals with cancer, but only a small portion of individuals with breast cancer respond well. Here we report that tumor-derived Jagged1 is a key regulator of the tumor immune microenvironment. Jagged1 promotes tumorigenesis in multiple spontaneous mammary tumor models. Through Jagged1-induced Notch activation, tumor cells increase expression and secretion of multiple cytokines to help recruit macrophages into the tumor microenvironment. Educated macrophages crosstalk with tumor-infiltrating T cells to inhibit T cell proliferation and tumoricidal activity. In individuals with triple-negative breast cancer, a high expression level of Jagged1 correlates with increased macrophage infiltration and decreased T cell activity. Co-administration of an ICI PD-1 antibody with a Notch inhibitor significantly inhibits tumor growth in breast cancer models. Our findings establish a distinct signaling cascade by which Jagged1 promotes adaptive immune evasion of tumor cells and provide several possible therapeutic targets.
    Keywords:  CD8(+) T cell; Jagged1; Notch; breast cancer; immune checkpoint inhibitor; macrophage; tumor microenvironment
  13. Oncogene. 2022 Mar 07.
      Mutant p53 (mtp53) can exert cancer-promoting activities via "gain-of-function", which has become a popular research target. Although lots of researchers focus on the tumor-suppressor role for p53, the regulation of mutant p53 remains unknown. Here, we report a mechanism by which mtp53 regulate the transcription of Rab coupling protein (RCP) to influence lung cancer behavior. First, we show that RCP is specifically expressed at high levels in lung cancer tissues and cells, and RCP knockout suppresses tumor growth and metastasis. Further mass spectrometry and functional analysis identify that Sp1, Sp3 and Stat3 are the transcriptional activators of RCP. Moreover, p53 is involved in modulating RCP expression in an Sp1/3 dependent manner. Mechanistically, in contrast to wild-type p53 suppression of RCP transcription by decreasing Sp1/3 proteins, TP53 mutations have changed on Sp1/3 expression via "loss-of-function". Surprisingly, the DNA contact mutants of p53 further robustly enhance their binding ability with Sp1/3 to drive RCP expression through the "gain-of-function" activity. Collectively, we reveal a mechanism by which p53 regulating the transcription of RCP to influence lung cancer progression, which provides new insights for treating p53 mutant lung cancer.
  14. Cancer Res. 2022 Mar 08. pii: canres.2463.2021. [Epub ahead of print]
      Heart failure and cancer are the leading cause of deaths worldwide. While heart failure and cancer have been considered separate diseases, it is becoming evident that they are highly connected and affect each other's outcomes. Recent studies using experimental mouse models have suggested that heart failure promotes tumor progression. The mouse models used involve major irreversible surgery. Here, we induced heart hypertrophy via expression of Activating Transcription Factor 3 (ATF3) in cardiomyocytes followed by cancer cells implantation. Tumors developing in ATF3-transgenic mice grew larger and displayed a more highly metastatic phenotype compared to tumors in wild-type mice. To address whether ATF3 expression or the cardiac outcome are necessary for tumor progression, ATF3 expression was turned off after cardiac hypertrophy development followed by cancer cell implantation. The tumor promotion phenotype as well as the enhancement of metastatic properties were preserved, suggesting that the failing heart per se is sufficient to promote tumor progression. Serum derived from ATF3-transgenic mice enhanced cancer cell proliferation and increased cancer cell metastatic properties in vitro. Using a cytokine array panel, multiple factors responsible for promoting tumor cell proliferation and the metastatic phenotype were identified. Interestingly, the failing heart and the tumor separately and simultaneously contributed to higher levels of these factors in the serum as well as other tissues and organs. These data suggest the existence of intimate crosstalk between the hypertrophied heart and the tumor which is mediated by secreted factors leading to cancer promotion and disease deterioration.
  15. J Immunother Cancer. 2022 Mar;pii: e004029. [Epub ahead of print]10(3):
      BACKGROUND: Platinum resistance is a major challenge in the clinical treatment of advanced ovarian cancer (OC). Accumulating evidence shows that the tumor-promotive M2 macrophage is linked to the limiting chemotherapy efficacy of multiple malignancies including OC. Circular RNAs (circRNAs) are a novel class of non-coding RNAs which function as the critical regulator in biological process of cancer. However, their impact on macrophage polarization and chemoresistance of OC remain unclear.METHODS: Platinum-resistant circRNAs were screened using circRNA deep sequencing and validated using in situ hybridization in OC tissues with or without platinum resistance. The role of circITGB6 in inducing cisplatin (CDDP) resistance was evaluated by clone formation, immunofluorescence and annexin V assays in vitro, and by intraperitoneal tumor model in vivo. The mechanism underlying circITGB6-mediated tumor-associated macrophage (TAM) polarization into M2 phenotype was investigated using RNA pull-down, luciferase reporter, electrophoretic mobility shift, RNA binding protein immunoprecipitation (RIP), ELISA and immunofluorescence assays.
    RESULTS: We identified that a novel circRNA, circITGB6, robustly elevated in tumor tissues and serums from patients with OC with platinum resistance, was correlated with poor prognosis. circITGB6 overexpression promoted an M2 macrophage-dependent CDDP resistance in both vivo and vitro. Mechanistic research determined that circITGB6 directly interacted with IGF2BP2 and FGF9 mRNA to form a circITGB6/IGF2BP2/FGF9 RNA-protein ternary complex in the cytoplasm, thereby stabilizing FGF9 mRNA and inducing polarization of TAMs toward M2 phenotype. Importantly, blocking M2 macrophage polarization with an antisense oligonucleotide targeting circITGB6 markedly reversed the circITGB6-induced CDDP resistance of OC in vivo.
    CONCLUSIONS: This study reveals a novel mechanism for platinum resistance in OC and demonstrates that circITGB6 may serve as a potential prognostic marker and a therapeutic target for patients with OC.
    Keywords:  macrophages; translational medical research; tumor microenvironment
  16. Cancer Res. 2022 Mar 03. pii: canres.2778.2021. [Epub ahead of print]
      The dynamic composition of the tumor microenvironment (TME) can markedly alter the response to targeted therapies for colorectal cancer (CRC). Cancer associated fibroblasts (CAF) are major components of TMEs that can direct and induce infiltration of immunosuppressive cells through secreted cytokines such as CXCL12. Ketogenic diets (KD) can inhibit tumor growth and enhance the anticancer effects of immune checkpoint blockade. However, the role of ketogenesis on the immunosuppressive TME is not known. Here, we show that decreased ketogenesis is a signature of CRC and that an increase in ketogenesis using a KD decreases CXCL12 production in tumors, serum, liver, and lungs. Moreover, increasing ketogenesis by overexpression of the ketogenic enzyme 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) or treatment with the ketone body β-hydroxybutyrate markedly decreased expression of KLF5, which binds the CXCL12 promoter and induces CXCL12 expression in CAFs. KD decreased intratumoral accumulation of immunosuppressive cells, increased infiltration of NK and cytotoxic T cells, and enhanced the anticancer effects of PD-1 blockade in murine-derived CRC. Furthermore, increasing ketogenesis inhibited CRC migration, invasion, and metastasis in vitro and in vivo. Overall, ketogenesis is downregulated in the CRC TME, and increased ketogenesis represses KLF5-dependent CXCL12 expression to improve the immunosuppressive TME, which leads to the enhanced efficacy of immunotherapy and reduced metastasis. Importantly, this work demonstrates that downregulation of de novo ketogenesis in the TME is a critical step in CRC progression.
  17. Oncogene. 2022 Mar 07.
      Oncogenic signalling confers tumour-progression advantages; thus, its pharmacological blockade is the best strategy for cancer chemotherapy. However, drug resistance and heterogeneous dependency of tumour hamper their therapeutic potential, suggesting the necessity for a new ubiquitous modality based on evading drug resistance. Here, we proposed a de novo addiction to oncogenic signalling (Dead-On) concept, wherein specific blockade of target molecules forces cancer cells to develop dependency on an oncogenic signalling. In cervical squamous cell carcinoma cells, Aurora A/B dual blockade elicited rapid addiction to EGFR-Erk signalling, and its pharmacological/genetic inhibition synergistically enhanced anti-cancer activities in vitro, in vivo, and in a patient-derived organoid model. The signal activation was independent of EGFR genetic status, it was triggered by receptor accumulation on the plasma membrane via Rab11-mediated endocytic recycling machinery. These findings support our novel Dead-On concept which may lead to drug discovery as well as expand the adaptation of approved targeted drugs.
  18. Autophagy. 2022 Mar 08. 1-18
      Mitochondrial oxidative phosphorylation (OXPHOS) generates ATP, but OXPHOS also supports biosynthesis during proliferation. In contrast, the role of OXPHOS during quiescence, beyond ATP production, is not well understood. Using mouse models of inducible OXPHOS deficiency in all cell types or specifically in the vascular endothelium that negligibly relies on OXPHOS-derived ATP, we show that selectively during quiescence OXPHOS provides oxidative stress resistance by supporting macroautophagy/autophagy. Mechanistically, OXPHOS constitutively generates low levels of endogenous ROS that induce autophagy via attenuation of ATG4B activity, which provides protection from ROS insult. Physiologically, the OXPHOS-autophagy system (i) protects healthy tissue from toxicity of ROS-based anticancer therapy, and (ii) provides ROS resistance in the endothelium, ameliorating systemic LPS-induced inflammation as well as inflammatory bowel disease. Hence, cells acquired mitochondria during evolution to profit from oxidative metabolism, but also built in an autophagy-based ROS-induced protective mechanism to guard against oxidative stress associated with OXPHOS function during quiescence.Abbreviations: AMPK: AMP-activated protein kinase; AOX: alternative oxidase; Baf A: bafilomycin A1; CI, respiratory complexes I; DCF-DA: 2',7'-dichlordihydrofluorescein diacetate; DHE: dihydroethidium; DSS: dextran sodium sulfate; ΔΨmi: mitochondrial inner membrane potential; EdU: 5-ethynyl-2'-deoxyuridine; ETC: electron transport chain; FA: formaldehyde; HUVEC; human umbilical cord endothelial cells; IBD: inflammatory bowel disease; LC3B: microtubule associated protein 1 light chain 3 beta; LPS: lipopolysaccharide; MEFs: mouse embryonic fibroblasts; MTORC1: mechanistic target of rapamycin kinase complex 1; mtDNA: mitochondrial DNA; NAC: N-acetyl cysteine; OXPHOS: oxidative phosphorylation; PCs: proliferating cells; PE: phosphatidylethanolamine; PEITC: phenethyl isothiocyanate; QCs: quiescent cells; ROS: reactive oxygen species; PLA2: phospholipase A2, WB: western blot.
    Keywords:  ATG4B; biosynthesis; cell death; electron transport chain; endothelial cells; mitochondria; oxidative phosphorylation; oxidative stress; reactive oxygen species
  19. Mol Cancer Res. 2022 Feb 23. pii: molcanres.MCR-21-0781-A.2021. [Epub ahead of print]
      Estrogen receptor-positive (ER+) metastatic tumors contribute to nearly 70% of breast cancer-related deaths. Most patients with ER+ metastatic breast cancer (MBC) undergo treatment with the estrogen receptor antagonist fulvestrant (Fulv) as standard-of-care. Yet, among such patients, metastasis in the liver is associated with reduced overall survival compared to other metastasis sites. The factors underlying the reduced responsiveness of liver metastases to ER-targeting agents remain unknown, impeding the development of more effective treatment approaches to improve outcomes for patients with ER+ liver metastases. We therefore evaluated site-specific changes in MBC cells and determined the mechanisms through which the liver metastatic niche specifically influences ER+ tumor metabolism and drug resistance. We characterized ER activity of MBC cells both in vitro, using a novel system of tissue-specific extracellular matrix hydrogels representing the stroma of ER+ tumor metastatic sites (liver, lung and bone), and in vivo, in liver and lung metastasis mouse models. ER+ metastatic liver tumors and MBC cells grown in liver hydrogels displayed upregulated expression of glucose metabolism enzymes in response to Fulv. Furthermore, differential ERα activity, but not expression, was detected in liver hydrogels. In vivo, increased glucose metabolism led to increased glycogen deposition in liver metastatic tumors, while a fasting-mimicking diet increased efficacy of Fulv treatment to reduce the metastatic burden. Our findings identify a novel mechanism of endocrine resistance driven by the liver tumor microenvironment. Implications: These results may guide the development of dietary strategies to circumvent drug resistance in liver metastasis, with potential applicability in other metastatic diseases.
  20. Cancer Treat Rev. 2022 Mar 01. pii: S0305-7372(22)00036-6. [Epub ahead of print]105 102372
      Thyroid cancer is the most frequently diagnosed endocrine malignancy, with an increasing incidence over the last decades. The recent advances in understanding the molecular mechanisms underlying the carcinogenesis of thyroid cancer have led to a better therapeutic approach of these tumors. This has allowed the development and approval of several drugs during the past decade. The rearranged during transfection [RET] protooncogene encodes a transmembrane receptor tyrosine kinase, which is activated by chromosomal rearrangements or point mutations in multiple malignancies, including thyroid cancer. Selective RET inhibitors have proved their value in the treatment algorithm in molecularly selected patients with significantly high response rates and duration of response. Notwithstanding, there are patients who experiment rapid progression or tumor recurrence after an early response to those targeted therapies, which suggest the existence of primary and acquired mechanisms of resistance that have been largely unknown to date. In the present review, we attempt to provide a comprehensive analysis of the most relevant mechanisms of resistance to RET inhibitors which could help in the development of next generation MKI and RET inhibitors, along with combination strategies with different targeted therapies that could potentially overcome these resistances.
    Keywords:  Medullary thyroid cancer; Papillary thyroid cancer; Poorly differentiated thyroid cancer; RET; RET inhibitors; Thyroid cancer; Tyrosine kinase inhibitors
  21. Nat Chem Biol. 2022 Mar 10.
      Precision oncology presumes an accurate prediction of drug response on the basis of the molecular profile of tumors. However, the extent to which patient-derived tumor organoids recapitulate the response of in vivo tumors to a given drug remains obscure. To gain insights into the pharmacobiology of human colorectal cancer (CRC), we here created a robust drug screening platform for patient-derived colorectal organoids. Application of suspension culture increased organoid scalability, and a refinement of the culture condition enabled incorporation of normal and precursor organoids to high-throughput drug screening. Drug screening identified bromodomain and extra-terminal (BET) bromodomain protein inhibitor as a cancer-selective growth suppressor that targets genes aberrantly activated in CRC. A multi-omics analysis identified an association between checkpoint with forkhead and ring finger domaines (CHFR) silencing and paclitaxel sensitivity, which was further validated by gene engineering of organoids and in xenografts. Our findings highlight the utility of multiparametric validation in enhancing the biological and clinical fidelity of a drug screening system.
  22. J Exp Med. 2022 Apr 04. pii: e20210739. [Epub ahead of print]219(4):
      KRAS mutations drive a quarter of cancer mortality, and most are undruggable. Several inhibitors of the MAPK pathway are FDA approved but poorly tolerated at the doses needed to adequately extinguish RAS/RAF/MAPK signaling in the tumor cell. We found that oncogenic KRAS signaling induced ferrous iron (Fe2+) accumulation early in and throughout mutant KRAS-mediated transformation. We converted an FDA-approved MEK inhibitor into a ferrous iron-activatable drug conjugate (FeADC) and achieved potent MAPK blockade in tumor cells while sparing normal tissues. This innovation allowed sustainable, effective treatment of tumor-bearing animals, with tumor-selective drug activation, producing superior systemic tolerability. Ferrous iron accumulation is an exploitable feature of KRAS transformation, and FeADCs hold promise for improving the treatment of KRAS-driven solid tumors.
  23. J Immunother Cancer. 2022 Mar;pii: e003402. [Epub ahead of print]10(3):
      BACKGROUND: Oncogenes act in a cell-intrinsic way to promote tumorigenesis. Whether oncogenes also have a cell-extrinsic effect on suppressing the immune response to cancer is less well understood.METHODS: We use an in vivo expression screen of known cancer-associated somatic mutations in mouse syngeneic tumor models treated with checkpoint blockade to identify oncogenes that promote immune evasion. We then validated candidates from this screen in vivo and analyzed the tumor immune microenvironment of tumors expressing mutant protein to identify mechanisms of immune evasion.
    RESULTS: We found that expression of a catalytically active mutation in phospho-inositol 3 kinase (PI3K), PIK3CA c.3140A>G (H1047R) confers a selective growth advantage to tumors treated with immunotherapy that is reversed by pharmacological PI3K inhibition. PIK3CA H1047R-expression in tumors decreased the number of CD8+ T cells but increased the number of inhibitory myeloid cells following immunotherapy. Inhibition of myeloid infiltration by pharmacological or genetic modulation of Ccl2 in PIK3CA H1047R tumors restored sensitivity to programmed cell death protein 1 (PD-1) checkpoint blockade.
    CONCLUSIONS: PI3K activation enables tumor immune evasion by promoting an inhibitory myeloid microenvironment. Activating mutations in PI3K may be useful as a biomarker of poor response to immunotherapy. Our data suggest that some oncogenes promote tumorigenesis by enabling tumor cells to avoid clearance by the immune system. Identification of those mechanisms can advance rational combination strategies to increase the efficacy of immunotherapy.
    Keywords:  biomarkers; immune evation; immunotherapy; tumor
  24. Cancer Res. 2022 Mar 01. pii: canres.2176.2021. [Epub ahead of print]
      Biliary cancer has long been known to carry a poor prognosis, yet the molecular pathogenesis of carcinoma of the extrahepatic biliary system and its precursor lesions remains elusive. Here we investigated the role of Kras and canonical Wnt pathways in the tumorigenesis of the extrahepatic bile duct (EHBD) and gall bladder (GB). In mice, concurrent activation of Kras and Wnt pathways induced biliary neoplasms that resembled human intracholecystic papillary-tubular neoplasm (ICPN) and biliary intraepithelial neoplasia (BilIN), putative precursors to invasive biliary cancer. At a low frequency, these lesions progressed to adenocarcinoma in a xenograft model, establishing them as precancerous lesions. Global gene expression analysis revealed increased expression of genes associated with c-Myc and TGF-β pathways in mutant biliary spheroids. Silencing or pharmacological inhibition of c-Myc suppressed proliferation of mutant biliary spheroids, whereas silencing of Smad4/Tgfbr2 or pharmacological inhibition of TGFβ signaling increased proliferation of mutant biliary spheroids and cancer formation in vivo. Human ICPNs displayed activated Kras and Wnt signals and c-Myc and TGFβ pathways. Thus, these data provide direct evidence that concurrent activation of the Kras and canonical Wnt pathways results in formation of ICPN and BilIN, which could develop into biliary cancer.
  25. Drug Resist Updat. 2022 Mar;pii: S1368-7646(22)00021-8. [Epub ahead of print]61 100822
      Cancer cell metabolism including aerobic glycolysis, amino acid and fatty acid metabolism, has been extensively studied. Metabolic reprogramming is a major hallmark of cancer, which promotes cancer cell proliferation, progression and metastasis, as well as provokes resistance to chemotherapeutic drugs. Several signal transduction pathways, such as BCR, MEK/ERK, Notch, NF-κB and PI3K/AKT/mTOR, regulate tumor metabolism, hence promoting tumor cell growth, proliferation and progression. Therefore, targeting metabolic enzymes, metabolites or their signal transduction pathways may constitute a promising therapeutic strategy to enhance cancer treatment efficacy. Diffuse large B-cell lymphoma (DLBCL) is the most aggressive form of non-Hodgkin lymphoma (NHL), and one-third of DLBCL patients suffer from relapsed/refractory disease after chemotherapy. The mechanisms underlying drug resistance are complex, including target gene mutations, metabolic reprogramming, aberrant signal transduction pathways, enhanced drug efflux via overexpression of multidrug efflux transporters like P-glycoprotein, upregulation of anti-apoptotic proteins, drug sequestration and enhanced DND repair. This review delineates the distinct metabolic reprogramming patterns and the association between metabolism and anticancer drug resistance in DLBCL as well as the emerging strategies to surmount chemoresistance in DLBCL.
    Keywords:  cancer drug resistance; diffuse large B cell lymphoma; tumor metabolism
  26. Cancer Discov. 2022 Feb 24. pii: candisc.1006.2021. [Epub ahead of print]
      Brain metastasis is a significant cause of morbidity and mortality in multiple cancer types and represents an unmet clinical need. The mechanisms that mediate metastatic cancer growth in the brain parenchyma are largely unknown. Melanoma, which has the highest rate of brain metastasis among common cancer types, is an ideal model to study how cancer cells adapt to the brain parenchyma. Our unbiased proteomics analysis of melanoma short-term cultures revealed that proteins implicated in neurodegenerative pathologies are differentially expressed in melanoma cells explanted from brain metastases compared to those derived from extracranial metastases. We showed that melanoma cells require amyloid beta (AB) for growth and survival in the brain parenchyma. Melanoma-secreted AB activates surrounding astrocytes to a pro-metastatic, anti-inflammatory phenotype and prevents phagocytosis of melanoma by microglia. Finally, we demonstrate that pharmacological inhibition of AB decreases brain metastatic burden.
  27. Cancer Discov. 2022 Feb 28. pii: candisc.1207.2021. [Epub ahead of print]
      Cutaneous T-cell lymphoma is a rare cancer of skin-homing T-cells. A subgroup of patients develops large cell transformation with rapid progression to an aggressive lymphoma. Here, we investigated the transformed CTCL (tCTCL) tumor ecosystem using integrative multiomics spanning whole exome sequencing (WES), single-cell RNA-seq and immune profiling in a unique cohort of 56 patients. WES of 70 skin biopsies showed high tumor mutation burden, UV signatures that are prognostic for survival, exome-based driver events and most recurrently mutated pathways in tCTCL. Single-cell profiling of 16 tCTCL skin biopsies identified a core oncogenic program with metabolic reprogramming toward oxidative phosphorylation, cellular plasticity, upregulation of MYC and E2F activities and down-regulation of MHC-I suggestive of immune escape. Pharmacologic perturbation using OXPHOS and MYC inhibitors demonstrated potent anti-tumor activities, while immune profiling provided in situ evidence of intercellular communications between malignant T-cells expressing macrophage migration inhibitory factor and macrophages and B-cells expressing CD74.
  28. Cancer Res. 2022 Mar 07. pii: canres.1820.2021. [Epub ahead of print]
      Trastuzumab is the only approved targeted drug for first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (GC), but the high rate of primary resistance and rapid emergence of secondary resistance limit its clinical benefits. We found that trastuzumab-resistant (TR) GC cells exhibited high glycolytic activity, which was controlled by hexokinase 2 (HK2)-dependent glycolysis with a circadian pattern (higher at zeitgeber time 6, lower at zeitgeber time 18). Mechanistically, HK2 circadian oscillation was regulated by a transcriptional complex composed of peroxisome proliferator-activated receptor γ (PPARγ) and the core clock gene PER1. In vivo and in vitro experiments demonstrated that silencing PER1 disrupted the circadian rhythm of PER1-HK2 and reversed trastuzumab resistance. Moreover, metformin, which inhibits glycolysis and PER1, combined with trastuzumab at zeitgeber time 6 significantly improved trastuzumab efficacy in GC. Collectively, these data introduce the circadian clock into trastuzumab therapy and propose a potentially effective chronotherapy strategy to reverse trastuzumab resistance in GC.
  29. Leukemia. 2022 Mar 10.
      Treatment options for patients with relapsed/refractory acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) are scarce. Recurring mutations, such as mutations in isocitrate dehydrogenase-1 and -2 (IDH1/2) are found in subsets of AML and MDS, are therapeutically targeted by mutant enzyme-specific small molecule inhibitors (IDHmi). IDH mutations induce diverse metabolic and epigenetic changes that drive malignant transformation. IDHmi alone are not curative and resistance commonly develops, underscoring the importance of alternate therapeutic options. We were first to report that IDH1/2 mutations induce a homologous recombination (HR) defect, which confers sensitivity to poly (ADP)-ribose polymerase inhibitors (PARPi). Here, we show that the PARPi olaparib is effective against primary patient-derived IDH1/2-mutant AML/ MDS xeno-grafts (PDXs). Olaparib efficiently reduced overall engraftment and leukemia-initiating cell frequency as evident in serial transplantation assays in IDH1/2-mutant but not -wildtype AML/MDS PDXs. Importantly, we show that olaparib is effective in both IDHmi-naïve and -resistant AML PDXs, critical given the high relapse and refractoriness rates to IDHmi. Our pre-clinical studies provide a strong rationale for the translation of PARP inhibition to patients with IDH1/2-mutant AML/ MDS, providing an additional line of therapy for patients who do not respond to or relapse after targeted mutant IDH inhibition.
  30. Mol Cancer. 2022 Mar 10. 21(1): 70
      BACKGROUND: Pancreatic cancer is one of the most lethal cancers worldwide. The IAPs function as E3 ubiquitin ligases and contribute to pancreatic cancer initiation, progression, and metastasis. Although IAP-targeted therapies have been developed and shown anticancer efficacy in preclinical settings, none of them has been approved yet.METHODS: Transcriptome data from public datasets were used to analyze the correlation of IAPs and E2s, and the biological function of E2 UbcH5c in pancreatic cancer. A structure-based virtual screen was used to identify UbcH5c inhibitor, and surface plasmon resonance analysis and cellular thermal shift assays were employed to evaluate the binding affinity. The anticancer activities were demonstrated through in vitro and in vivo assays, while the related mechanisms were explored through transcriptomic and proteomic analyses and confirmed by western blot, immunofluorescence, and qRT-PCR.
    RESULTS: UbcH5c is positively correlated with the expression of IAPs in pancreatic cancer. We further found that UbcH5c is overexpressed and associated with a poor prognosis in pancreatic cancer. We identified a small-molecule UbcH5c inhibitor, termed DHPO, which directly bound to UbcH5c protein. DHPO inhibited cell viability and colony formation, induced apoptosis, and suppressed migration and invasion of pancreatic cancer cells in vitro. The compound inhibited UbcH5c-mediated IκBα degradation and NF-κB activation, which is critical for its anticancer activity. Furthermore, DHPO suppressed the tumor growth and metastasis in two orthotopic pancreatic tumor mouse models.
    CONCLUSIONS: These results indicated that inhibiting UbcH5c is a novel and effective strategy for treating pancreatic cancer and DHPO represents a new class of UbcH5c inhibitor and may be further developed as an anti-pancreatic cancer therapeutic agent.
    Keywords:  IAP; NF-κB; Pancreatic cancer; Small-molecule inhibitor; UbcH5c
  31. Cancer Discov. 2022 Mar 01. 12(3): 604-605
      Isocitrate dehydrogenase 1 mutations (mIDH1) are common in cholangiocarcinoma, but their exact mechanisms in cholangiocarcinoma initiation and maintenance are unclear. In this issue of Cancer Discovery, Wu and colleagues identify immune suppression via TET2 inactivation as the primary means by which mIDH1 maintains cholangiocarcinoma survival, leading to an efficacious new combination of mIDH1 inhibitors and immune checkpoint blockade targeting regulatory T cells. See related article by Wu et al., p. 812 (9).
  32. Cell Rep. 2022 Mar 08. pii: S2211-1247(22)00226-1. [Epub ahead of print]38(10): 110493
      Unlike most cell types, many cancer cells survive at low extracellular pH (pHe), a chemical signature of tumors. Genes that facilitate survival under acid stress are therefore potential targets for cancer therapies. We performed a genome-wide CRISPR-Cas9 cell viability screen at physiological and acidic conditions to systematically identify gene knockouts associated with pH-related fitness defects in colorectal cancer cells. Knockouts of genes involved in oxidative phosphorylation (NDUFS1) and iron-sulfur cluster biogenesis (IBA57, NFU1) grew well at physiological pHe, but underwent profound cell death under acidic conditions. We identified several small-molecule inhibitors of mitochondrial metabolism that can kill cancer cells at low pHe only. Xenografts established from NDUFS1-/- cells grew considerably slower than their wild-type controls, but growth could be stimulated with systemic bicarbonate therapy that lessens the tumoral acid stress. These findings raise the possibility of therapeutically targeting mitochondrial metabolism in combination with acid stress as a cancer treatment option.
    Keywords:  CRISPR-Cas9 screen; acidosis; oxidative phosphorylation; tumor acidity
  33. Proc Natl Acad Sci U S A. 2022 03 15. 119(11): e2117013119
      SignificanceThe study provided a long-sought molecular mechanism that could explain the link between fatty acid metabolism and cancer metastasis. Further understanding may lead to new strategies to inhibit cancer metastasis. The chemical proteomic approach developed here will be useful for discovering other regulatory mechanisms of protein function by small molecule metabolites.
    Keywords:  NME1; NME2; fatty acid; long-chain fatty acyl coenzyme A; tumor metastasis