bims-tucedo 2021-02-28 papers

bims-tucedo

Biomed News

on Tumor cell dormancy

Issue of 2021‒02‒28
twenty-six papers selected by
Isabel Puig Borreil
Vall d’Hebron Institute of Oncology

Disseminated cancer cells in breast cancer: mechanism of dissemination and dormancy and emerging insights on therapeutic opportunities.
Loss of optineurin drives cancer immune evasion via palmitoylation-dependent IFNGR1 lysosomal sorting and degradation.
Genomic evolution and diverse models of systemic metastases in colorectal cancer.
Comprehensive mutational analysis of the BRCA1-associated DNA helicase and tumor suppressor, FANCJ/BACH1/BRIP1.
Development and characterization of novel endoxifen-resistant breast cancer cell lines highlight numerous differences from tamoxifen-resistant models.
Network models of primary melanoma microenvironments identify key melanoma regulators underlying prognosis.
Implication of cancer associated fibroblast subtypes on cancer pathogenesis, prognosis, and immunotherapy resistance.
Intraductal xenografts show lobular carcinoma cells rely on their own extracellular matrix and LOXL1.
Acquired cancer cell resistance to T cell bispecific antibodies and CAR T targeting HER2 through JAK2 down-modulation.
PAF remodels the DREAM complex to bypass cell quiescence and promote lung tumorigenesis.
Variability within rare cell states enables multiple paths toward drug resistance.
Liquid biopsy proteomics of uveal melanoma reveals biomarkers associated with metastatic risk.
Bacterial-driven inflammation and mutant BRAF expression combine to promote murine colon tumorigenesis that is sensitive to immune checkpoint therapy.
The pathological significance of LOXL2 in pre-metastatic niche formation of HCC and its related molecular mechanism.
Exosomes in breast cancer - Mechanisms of Action and Clinical Potential.
Targeting EphA2 suppresses hepatocellular carcinoma initiation and progression by dual inhibition of JAK1/STAT3 and AKT signaling.
Functional reconstruction of human AML reveals stem cell origin and vulnerability of treatment-resistant MLL-rearranged leukemia.
5-Fluorouracil efficacy requires anti-tumor immunity triggered by cancer-cell-intrinsic STING.
Pan-cancer transcriptomic predictors of perineural invasion improve occult histopathological detection.
Identification of resistance pathways and therapeutic targets in relapsed multiple myeloma patients through single-cell sequencing.
Nerve growth factor receptor increases the tumor growth and metastatic potential of triple-negative breast cancer cells.
Working Scientist podcast: How to get media coverage for your research.
Free lists of grants and fellowships around the world available online.
Cytoplasmic localization of prostate-specific membrane antigen inhibitors may confer advantages for targeted cancer therapies.
DNA hypomethylating agents increase activation and cytolytic activity of CD8+ T cells.
Spatially mapped single-cell chromatin accessibility.

Semin Cancer Biol. 2021 Feb 21. pii: S1044-579X(21)00027-4. [Epub ahead of print]

Disseminated cancer cells in breast cancer: mechanism of dissemination and dormancy and emerging insights on therapeutic opportunities.

Ganesan Ramamoorthi, Krithika Kodumudi, Corey Gallen, Nadia Nocera Zachariah, Amrita Basu, Gabriella Albert, Amber Beyer, Colin Snyder, Doris Wiener, Ricardo L B Costa, Brian J Czerniecki.

  Metastatic spread in breast cancer patients is the major driver of cancer-related deaths. A unique subset of cells disseminated from pre-invasive or primary tumor lesions are recognized as the main seeds for metastatic outgrowth. Disseminated cancer cells (DCCs) can migrate to distant organs and settle in a dormant state for a prolonged period until they emerge to overt metastases. Understanding the biology of breast cancer cells dissemination, dormancy and reactivation to form overt metastases has become an important focus. In this review, we discuss the recent advancements of molecular pathways involving breast cancer cell dissemination, role of chemokine-chemokine receptor networks in DCCs migration, DCCs phenotypic heterogeneity and unique genes signatures in tumor dormancy, microenvironmental regulation and specific niches that favors DCCs homing and dormancy. In addition, we also discuss recent findings relating to the role of immune response on DCC dissemination and dormancy. With recent advances in the field of immunotherapy/targeted therapy and its beneficial effects in cancer treatment, this review will focus on their impact on DCCs, reversal of stemness, tumor dormancy and metastatic relapse.

Keywords:  Breast cancer; Th1 immune cells and immunotherapy; disseminated cancer cells; metastasis

DOI:  https://doi.org/10.1016/j.semcancer.2021.02.004
Cancer Discov. 2021 Feb 24. pii: candisc.1571.2020. [Epub ahead of print]

Loss of optineurin drives cancer immune evasion via palmitoylation-dependent IFNGR1 lysosomal sorting and degradation.

Wan Du, Fang Hua, Xiong Li, Jian Zhang, Shasha Li, Weichao Wang, Jiajia Zhou, Weimin Wang, Peng Liao, Yijian Yan, Gaopeng Li, Shuang Wei, Sara Grove, Linda Vatan, Witold Zgodzinski, Marek Majewski, Grzegorz Wallner, Haoyan Chen, Ilona Kryczek, Jing-Yuan Fang, Weiping Zou.

Mutations in IFN- and MHC-signaling genes endow immunotherapy resistance. Colorectal cancer patients infrequently exhibit IFN- and MHC-signaling gene mutations, and are generally resistant to immunotherapy. In exploring the integrity of the IFN- and MHC-signaling in colorectal cancer, we found that optineurin was a shared node between the two pathways, and predicted colorectal cancer patient outcome. Loss of optineurin occurred in early stage human colorectal cancer. Immunologically, optineurin deficiency attenuated IFNGR1 and MHC-I expression, impaired T cell-immunity, and diminished immunotherapy efficacy in murine cancer models and cancer patients. Mechanistically, IFNGR1 was S-palmitoylated on Cys122, and AP3D1 bound with and sorted palmitoylated-IFNGR1 to lysosome for degradation. Unexpectedly, optineurin interacted with AP3D1 to prevent palmitoylated-IFNGR1 lysosomal sorting and degradation - thereby maintaining IFNy- and MHC-I-signaling integrity. Furthermore, pharmacologically targeting IFNGR1-palmitoylation stabilized IFNGR1, augmented tumor immunity, and sensitized checkpoint therapy. Thus, loss of optineurin drives immune evasion and intrinsic immunotherapy resistance in colorectal cancer.

DOI: https://doi.org/10.1158/2159-8290.CD-20-1571
Gut. 2021 Feb 25. pii: gutjnl-2020-323703. [Epub ahead of print]

Genomic evolution and diverse models of systemic metastases in colorectal cancer.

Hai-Ning Chen, Yang Shu, Fei Liao, Xue Liao, Hongying Zhang, Yun Qin, Zhu Wang, Maochao Luo, Qiuluo Liu, Zhinan Xue, Minyuan Cao, Shouyue Zhang, Wei-Han Zhang, Qianqian Hou, Xuyang Xia, Han Luo, Yan Zhang, Lie Yang, Jian-Kun Hu, Xianghui Fu, Bo Liu, Hongbo Hu, Canhua Huang, Yong Peng, Wei Cheng, Lunzhi Dai, Li Yang, Wei Zhang, Biao Dong, Yuan Li, Yuquan Wei, Heng Xu, Zong-Guang Zhou.

  OBJECTIVE: The systemic spread of colorectal cancer (CRC) is dominated by the portal system and exhibits diverse patterns of metastasis without systematical genomic investigation. Here, we evaluated the genomic evolution of CRC with multiorgan metastases using multiregion sequencing.DESIGN: Whole-exome sequencing was performed on multiple regions (n=74) of matched primary tumour, adjacent non-cancerous mucosa, liver metastasis and lung metastasis from six patients with CRC. Phylogenetic reconstruction and evolutionary analyses were used to investigate the metastatic seeding pattern and clonal origin. Recurrent driver gene mutations were analysed across patients and validated in two independent cohorts. Metastatic assays were performed to examine the effect of the novel driver gene on the malignant behaviour of CRC cells.
RESULTS: Based on the migration patterns and clonal origins, three models were revealed (sequential, branch-off and diaspora), which not only supported the anatomic assumption that CRC cells spread to lung after clonally expanding in the liver, but also illustrated the direct seeding of extrahepatic metastases from primary tumours independently. Unlike other cancer types, polyphyletic seeding occurs in CRC, which may result in late metastases with intermetastatic driver gene heterogeneity. In cases with rapid dissemination, we found recurrent trunk loss-of-function mutations in ZFP36L2, which is enriched in metastatic CRC and associated with poor overall survival. CRISPR/Cas9-mediated knockout of ZFP36L2 enhances the metastatic potential of CRC cells.
CONCLUSION: Our results provide genomic evidence for metastatic evolution and indicate that biopsy/sequencing of metastases may be considered for patients with CRC with multiorgan or late postoperative metastasis.

Keywords:  colorectal cancer; colorectal metastases; gene mutation

DOI:  https://doi.org/10.1136/gutjnl-2020-323703
Mol Cancer Res. 2021 Feb 22. pii: molcanres.MCR-20-0828-A.2020. [Epub ahead of print]

Comprehensive mutational analysis of the BRCA1-associated DNA helicase and tumor suppressor, FANCJ/BACH1/BRIP1.

Jennifer A Calvo, Briana Fritchman, Desiree Hernandez, Nicole S Persky, Cory M Johannessen, Federica Piccioni, Brian A Kelch, Sharon B Cantor.

FANCJ (BRIP1/BACH1) is a hereditary breast and ovarian cancer (HBOC) gene encoding a DNA helicase. Similar to HBOC genes, BRCA1 and BRCA2, FANCJ is critical for processing DNA inter-strand crosslinks (ICL) induced by chemotherapeutics, such as cisplatin. Consequently, cells deficient in FANCJ or its catalytic activity are sensitive to ICL-inducing agents. Unfortunately, the majority of FANCJ clinical mutations remain uncharacterized, limiting therapeutic opportunities to effectively use cisplatin to treat tumors with mutated FANCJ. Here we sought to perform a comprehensive screen to identify FANCJ loss-of-function (LOF) mutations. We developed a FANCJ lentivirus mutation library representing ~450 patient derived-FANCJ nonsense and missense mutations to introduce FANCJ mutants into FANCJ knockout (K/O) HeLa cells. We performed a high-throughput screen to identify FANCJ LOF mutants that, as compared to wildtype FANCJ, fail to robustly restore resistance to ICL-inducing agents, cisplatin or mitomycin C (MMC). Based on the failure to confer resistance to either cisplatin or MMC, we identified 26 missense and 25 nonsense LOF mutations. Nonsense mutations elucidated a relationship between location of truncation and ICL sensitivity, as the majority of nonsense mutations before amino acid 860 confer ICL sensitivity. Further validation of a subset of LOF mutations confirmed the ability of the screen to identify FANCJ mutations unable to confer ICL resistance. Finally, mapping the location of LOF mutations to a new homology model additional functional information. Implications: We identify 51 FANCJ LOF mutations, providing important classification of FANCJ mutations that will afford additional therapeutic strategies for affected patients.

DOI: https://doi.org/10.1158/1541-7786.MCR-20-0828
Mol Cancer Res. 2021 Feb 24. pii: molcanres.MCR-20-0872-A.2020. [Epub ahead of print]

Development and characterization of novel endoxifen-resistant breast cancer cell lines highlight numerous differences from tamoxifen-resistant models.

Calley J Jones, Malayannan Subramaniam, Michael J Emch, Elizabeth S Bruinsma, James N Ingle, Matthew P Goetz, John R Hawse.

Despite the availability of drugs that target ERα-positive breast cancer, resistance commonly occurs, resulting in relapse, metastasis, and death. Tamoxifen remains the most commonly-prescribed endocrine therapy worldwide, and "tamoxifen resistance" has been extensively studied. However, little consideration has been given to the role of endoxifen, the most abundant active tamoxifen metabolite detected in patients, in driving resistance mechanisms. Endoxifen functions differently from the parent drug and other primary metabolites, including 4-hydroxy-tamoxifen (4HT). Many studies have shown that patients who extensively metabolize tamoxifen into endoxifen have superior outcomes relative to patients who do not, supporting a primary role for endoxifen in driving tamoxifen responses. Therefore, "tamoxifen resistance" may be better modeled by "endoxifen resistance" for some patients. Here, we report the development of novel endoxifen-resistant breast cancer cell lines and have extensively compared these models to 4HT and fulvestrant (ICI)-resistant models. Endoxifen-resistant cells were phenotypically and molecularly distinct from 4HT-resistant cells and more closely resembled ICI-resistant cells overall. Specifically, endoxifen resistance was associated with ERα and PR loss, estrogen insensitivity, unique gene signatures, and striking resistance to most FDA-approved second- and third-line therapies. Given these findings, and the importance of endoxifen in the efficacy of tamoxifen therapy, our data indicate that endoxifen-resistant models may be more clinically relevant than existing models and suggest that a better understanding of endoxifen resistance could substantially improve patient care. Implications: Here we develop and characterize the first endoxifen-resistant models and demonstrate that endoxifen resistance may better model tamoxifen resistance in a subset of patients.

DOI: https://doi.org/10.1158/1541-7786.MCR-20-0872
Nat Commun. 2021 02 22. 12(1): 1214

Network models of primary melanoma microenvironments identify key melanoma regulators underlying prognosis.

Won-Min Song, Praveen Agrawal, Richard Von Itter, Barbara Fontanals-Cirera, Minghui Wang, Xianxiao Zhou, Lara K Mahal, Eva Hernando, Bin Zhang.

Melanoma is the most lethal skin malignancy, driven by genetic and epigenetic alterations in the complex tumour microenvironment. While large-scale molecular profiling of melanoma has identified molecular signatures associated with melanoma progression, comprehensive systems-level modeling remains elusive. This study builds up predictive gene network models of molecular alterations in primary melanoma by integrating large-scale bulk-based multi-omic and single-cell transcriptomic data. Incorporating clinical, epigenetic, and proteomic data into these networks reveals key subnetworks, cell types, and regulators underlying melanoma progression. Tumors with high immune infiltrates are found to be associated with good prognosis, presumably due to induced CD8+ T-cell cytotoxicity, via MYO1F-mediated M1-polarization of macrophages. Seventeen key drivers of the gene subnetworks associated with poor prognosis, including the transcription factor ZNF180, are tested for their pro-tumorigenic effects in vitro. The anti-tumor effect of silencing ZNF180 is further validated using in vivo xenografts. Experimentally validated targets of ZNF180 are enriched in the ZNF180 centered network and the known pathways such as melanoma cell maintenance and immune cell infiltration. The transcriptional networks and their critical regulators provide insights into the molecular mechanisms of melanomagenesis and pave the way for developing therapeutic strategies for melanoma.

DOI: https://doi.org/10.1038/s41467-021-21457-0
Clin Cancer Res. 2021 Feb 23. pii: clincanres.4226.2020. [Epub ahead of print]

Implication of cancer associated fibroblast subtypes on cancer pathogenesis, prognosis, and immunotherapy resistance.

Phillip M Galbo, Xingxing Zang, Deyou Zheng.

PURPOSE: Cancer associated fibroblasts (CAFs) are an important component of the tumor microenvironment (TME), but a systematic investigation of their molecular characteristics and clinical relevance are lacking. Here, we sought to compare CAFs across multiple cancer types to identify critical molecular pathways activated in CAF subtypes, which may contribute to clinical outcome, disease progression, and immunotherapy resistance.EXPERIMENTAL DESIGN: We performed integrated analysis of CAFs from melanoma (MEL), head and neck squamous cell carcinoma (HNSC), and lung cancer (LC), and identified the molecular characteristics that are distinctly active in each CAF subtype. Gene signatures for individual CAF subtypes were identified and used to study the association of subtype abundance with clinical outcome and immunotherapy resistance.
RESULTS: We identified six CAF subtypes (pan-CAFs) shared across cancer types and uncovered the molecular characteristics and genetic pathways distinguishing them. Interestingly, these CAF subtypes express distinct immunosuppressive factors, such as CXCL12 and CXLC14, and stem-cell promoting factor IL-6. Additionally, we identified novel transcriptional drivers (MEF2C, TWIST1, NR1H3, RELB, and FOXM1) key to CAF heterogeneity. Furthermore, we showed that CAF subtypes were associated with different clinical outcomes and uncovered key molecular pathways that could activate or suppress cancer progression or were involved in resistance to anti-PD1 or anti-PD-L1 immunotherapy.
CONCLUSIONS: Our study identifies the molecular characteristics of CAF subtypes shared across several cancer types, implicates cancer types that may benefit from CAF subtype targeted therapies, and identifies specific CAF subtypes associated with immunotherapy resistance.

DOI: https://doi.org/10.1158/1078-0432.CCR-20-4226
EMBO Mol Med. 2021 Feb 22. e13180

Intraductal xenografts show lobular carcinoma cells rely on their own extracellular matrix and LOXL1.

George Sflomos, Laura Battista, Patrick Aouad, Fabio De Martino, Valentina Scabia, Athina Stravodimou, Ayyakkannu Ayyanan, Assia Ifticene-Treboux, , Philipp Bucher, Maryse Fiche, Giovanna Ambrosini, Cathrin Brisken.

  Invasive lobular carcinoma (ILC) is the most frequent special histological subtype of breast cancer, typically characterized by loss of E-cadherin. It has clinical features distinct from other estrogen receptor-positive (ER+ ) breast cancers but the molecular mechanisms underlying its characteristic biology are poorly understood because we lack experimental models to study them. Here, we recapitulate the human disease, including its metastatic pattern, by grafting ILC-derived breast cancer cell lines, SUM-44 PE and MDA-MB-134-VI cells, into the mouse milk ducts. Using patient-derived intraductal xenografts from lobular and non-lobular ER+ HER2- tumors to compare global gene expression, we identify extracellular matrix modulation as a lobular carcinoma cell-intrinsic trait. Analysis of TCGA patient datasets shows matrisome signature is enriched in lobular carcinomas with overexpression of elastin, collagens, and the collagen modifying enzyme LOXL1. Treatment with the pan LOX inhibitor BAPN and silencing of LOXL1 expression decrease tumor growth, invasion, and metastasis by disrupting ECM structure resulting in decreased ER signaling. We conclude that LOXL1 inhibition is a promising therapeutic strategy for ILC.

Keywords:  LOXL1; extracellular matrix; lobular carcinoma; preclinical models; xenografts

DOI:  https://doi.org/10.15252/emmm.202013180
Nat Commun. 2021 02 23. 12(1): 1237

Acquired cancer cell resistance to T cell bispecific antibodies and CAR T targeting HER2 through JAK2 down-modulation.

Enrique J Arenas, Alex Martínez-Sabadell, Irene Rius Ruiz, Macarena Román Alonso, Marta Escorihuela, Antonio Luque, Carlos Alberto Fajardo, Alena Gros, Christian Klein, Joaquín Arribas.

Immunotherapy has raised high expectations in the treatment of virtually every cancer. Many current efforts are focused on ensuring the efficient delivery of active cytotoxic cells to tumors. It is assumed that, once these active cytotoxic cells are correctly engaged to cancer cells, they will unfailingly eliminate the latter, provided that inhibitory factors are in check. T cell bispecific antibodies (TCBs) and chimeric antigen receptors (CARs) offer an opportunity to test this assumption. Using TCB and CARs directed against HER2, here we show that disruption of interferon-gamma signaling confers resistance to killing by active T lymphocytes. The kinase JAK2, which transduces the signal initiated by interferon-gamma, is a component repeatedly disrupted in several independently generated resistant models. Our results unveil a seemingly widespread strategy used by cancer cells to resist clearance by redirected lymphocytes. In addition, they open the possibility that long-term inhibition of interferon-gamma signaling may impair the elimination phase of immunoediting and, thus, promote tumor progression.

DOI: https://doi.org/10.1038/s41467-021-21445-4
Mol Cell. 2021 Feb 17. pii: S1097-2765(21)00087-3. [Epub ahead of print]

PAF remodels the DREAM complex to bypass cell quiescence and promote lung tumorigenesis.

Moon Jong Kim, Christopher Cervantes, Youn-Sang Jung, Xiaoshan Zhang, Jie Zhang, Sung Ho Lee, Sohee Jun, Larisa Litovchick, Wenqi Wang, Junjie Chen, Bingliang Fang, Jae-Il Park.

  The DREAM complex orchestrates cell quiescence and the cell cycle. However, how the DREAM complex is deregulated in cancer remains elusive. Here, we report that PAF (PCLAF/KIAA0101) drives cell quiescence exit to promote lung tumorigenesis by remodeling the DREAM complex. PAF is highly expressed in lung adenocarcinoma (LUAD) and is associated with poor prognosis. Importantly, Paf knockout markedly suppressed LUAD development in mouse models. PAF depletion induced LUAD cell quiescence and growth arrest. PAF is required for the global expression of cell-cycle genes controlled by the repressive DREAM complex. Mechanistically, PAF inhibits DREAM complex formation by binding to RBBP4, a core DREAM subunit, leading to transactivation of DREAM target genes. Furthermore, pharmacological mimicking of PAF-depleted transcriptomes inhibited LUAD tumor growth. Our results unveil how the PAF-remodeled DREAM complex bypasses cell quiescence to promote lung tumorigenesis and suggest that the PAF-DREAM axis may be a therapeutic vulnerability in lung cancer.

Keywords:  Cell Cycle; DREAM complex; KIAA0101; KRAS; PAF; PCLAF; PCNA; RBBP4; cell quiescence; lung cancer

DOI:  https://doi.org/10.1016/j.molcel.2021.02.001
Nat Biotechnol. 2021 Feb 22.

Variability within rare cell states enables multiple paths toward drug resistance.

Benjamin L Emert, Christopher J Cote, Eduardo A Torre, Ian P Dardani, Connie L Jiang, Naveen Jain, Sydney M Shaffer, Arjun Raj.

Molecular differences between individual cells can lead to dramatic differences in cell fate, such as death versus survival of cancer cells upon drug treatment. These originating differences remain largely hidden due to difficulties in determining precisely what variable molecular features lead to which cellular fates. Thus, we developed Rewind, a methodology that combines genetic barcoding with RNA fluorescence in situ hybridization to directly capture rare cells that give rise to cellular behaviors of interest. Applying Rewind to BRAFV600E melanoma, we trace drug-resistant cell fates back to single-cell gene expression differences in their drug-naive precursors (initial frequency of ~1:1,000-1:10,000 cells) and relative persistence of MAP kinase signaling soon after drug treatment. Within this rare subpopulation, we uncover a rich substructure in which molecular differences among several distinct subpopulations predict future differences in phenotypic behavior, such as proliferative capacity of distinct resistant clones after drug treatment. Our results reveal hidden, rare-cell variability that underlies a range of latent phenotypic outcomes upon drug exposure.

DOI: https://doi.org/10.1038/s41587-021-00837-3
Mol Cancer. 2021 Feb 24. 20(1): 39

Liquid biopsy proteomics of uveal melanoma reveals biomarkers associated with metastatic risk.

Gabriel Velez, Huy V Nguyen, Teja Chemudupati, Cassie A Ludwig, Marcus Toral, Sunil Reddy, Prithvi Mruthyunjaya, Vinit B Mahajan.



Keywords:  Biomarker; Cancer; HGFR; Liquid biopsy; Proteomics; SCFR; STAT3; Uveal melanoma; Vitreous

DOI:  https://doi.org/10.1186/s12943-021-01336-4
Cancer Discov. 2021 Feb 25. pii: candisc.0770.2020. [Epub ahead of print]

Bacterial-driven inflammation and mutant BRAF expression combine to promote murine colon tumorigenesis that is sensitive to immune checkpoint therapy.

Christina E DeStefano Shields, James R White, Liam Chung, Alyssa Wenzel, Jessica L Hicks, Ada J Tam, June L Chan, Christine M Dejea, Hongni Fan, John Michel, Ashley R Maiuri, Shruthi Sriramkumar, Ram Podicheti, Douglas B Rusch, Hao Wang, Angelo M De Marzo, Sepideh Besharati, Robert A Anders, Stephen B Baylin, Heather M O'Hagan, Franck Housseau, Cynthia L Sears.

Colorectal cancer (CRC) is multi-faceted with subtypes defined by genetic, histological, and immunologic features which are potentially influenced by inflammation, mutagens, and/or microbiota. CRCs with activating mutations in BRAF are associated with distinct clinical characteristics though the pathogenesis is not well understood. The Wnt-driven multiple intestinal neoplasia (MinApc[triangle]716/+) enterotoxigenic Bacteroides fragilis (ETBF) murine model is characterized by IL-17-dependent, distal colon adenomas. Herein, we report that addition of the BRAFV600E mutation to this model results in emergence of a distinct locus of mid-colon tumors. In ETBF-colonized BRAFV600ELgr5CreMin (BLM) mice, tumors have similarities to human BRAFV600E tumors, including histology, CpG island DNA hypermethylation, and immune signatures. In comparison to Min ETBF tumors, BLM ETBF tumors are infiltrated by CD8+ T cells, express interferon-gamma signatures, and are sensitive to anti-PDL1 treatment. These results provide direct evidence for critical roles of host genetic and microbiota interactions in CRC pathogenesis and sensitivity to immunotherapy.

DOI: https://doi.org/10.1158/2159-8290.CD-20-0770
Eur J Cancer. 2021 Feb 19. pii: S0959-8049(21)00022-8. [Epub ahead of print]147 63-73

The pathological significance of LOXL2 in pre-metastatic niche formation of HCC and its related molecular mechanism.

Sifan Wu, Xiaoxia Xing, Yaohui Wang, Xi Zhang, Miao Li, Mimi Wang, Zhiming Wang, Jie Chen, Dongmei Gao, Yan Zhao, Rongxin Chen, Zhenggang Ren, Kezhi Zhang, Jiefeng Cui.

  OBJECTIVE: The mechanisms underlying the contribution of primary tumour to pre-metastatic niche formation remains largely unknown in hepatocellular carcinoma (HCC). We previously reported that the released LOXL2 from HCC cells under higher stiffness stimulation facilitated the formation of lung pre-metastatic niche. Here, we further clarified the pathological role of LOXL2 in promoting lung pre-metastatic niche formation and lung metastasis occurrence in HCC and its relevant molecular mechanism.METHODS: Using two different animal models and an in vitro system of mechanically tuneable gel mirroring lung tissue stiffness, we explored the underlying mechanism of LOXL2 in pre-metastatic niche formation.
RESULTS: We applied tail vein injection of CM-LV-LOXL2-OEsimulating tumour-released soluble factors to induce lung pre-metastatic niche formation and found that the injected LOXL2 remarkably enhanced CD11b+/CD45+ bone marrow-derived cells (BMDCs) recruitment and fibronectin expression in lung. Subsequently, LOXL2-overexpressed xenograft HCC models validated that tumour-secreted LOXL2 significantly promoted the occurrence of pulmonary metastasis. In vitro, LOXL2 and LOXL2-caused matrix stiffening not only obviously upregulated the expressions of MMP9 and fibronectin in lung fibroblasts, but also evidently increased the number of adherent HCC cells and the expression of chemokine CXCL12. The activation of PI3K-AKT pathway mediated LOXL2-upregulated fibronectin. HCC patients in High-LOXL2 group had higher ratio of tumour recurrence than HCC patients in Low-LOXL2 group, supporting a significance of LOXL2 in HCC progression and unfavourable outcome.
CONCLUSION: Primary tumour-released LOXL2 promotes lung pre-metastatic niche formation and lung metastasis occurrence. LOXL2-caused matrix stiffening synergistically regulates lung pre-metastatic niche formation. Targeting LOXL2-induced lung pre-metastatic niche may be a novel intervention approach against HCC metastasis.

Keywords:  Hepatocellular carcinoma; LOXL2; Pre-metastatic niche

DOI:  https://doi.org/10.1016/j.ejca.2021.01.011
Mol Cancer Res. 2021 Feb 24. pii: molcanres.0952.2020. [Epub ahead of print]

Exosomes in breast cancer - Mechanisms of Action and Clinical Potential.

Tiantong Liu, Jagmohan Hooda, Jennifer M Atkinson, Theresa L Whiteside, Steffi Oesterreich, Adrian V Lee.

Extracellular vesicles (EVs) are a heterogeneous group of cell-derived membrane vesicles comprising apoptotic bodies, microvesicles and small EVs also called as exosomes. Exosomes when initially identified were considered as a waste product but the advancement in research techniques have provided insight into the important roles of exosomes in cell-cell communication, various biological process and disease, including cancer. As an important component of EVs, exosomes contain various biomolecules such as microRNAs (miRs), lipids and proteins that largely reflect the characteristics of their parent cells. Notably, cancer cells generate and secrete many more exosomes than normal cells. A growing body of evidence suggests that exosomes, as mediators of intercellular crosstalk, play a role in tumorigenesis, cancer cell invasion, angiogenesis, tumor microenvironment (TME) formation and cancer metastasis. As we gain more insights into the association between exosomes and cancer, the potential of exosomes for clinical use is becoming more intriguing. This review is focused on the role of exosomes in breast cancer, in terms of breast cancer biology, mechanism of action, potential as biomarkers and therapeutic opportunities.

DOI: https://doi.org/10.1158/1541-7786.MCR-20-0952
Cell Rep. 2021 Feb 23. pii: S2211-1247(21)00078-4. [Epub ahead of print]34(8): 108765

Targeting EphA2 suppresses hepatocellular carcinoma initiation and progression by dual inhibition of JAK1/STAT3 and AKT signaling.

Hao Wang, Wei Hou, Aldeb Perera, Carlee Bettler, Jordan R Beach, Xianzhong Ding, Jun Li, Mitchell F Denning, Asha Dhanarajan, Scott J Cotler, Cara Joyce, Jun Yin, Fowsiyo Ahmed, Lewis R Roberts, Wei Qiu.

  Hepatocellular carcinoma (HCC) remains one of the deadliest malignancies worldwide. One major obstacle to treatment is a lack of effective molecular-targeted therapies. In this study, we find that EphA2 expression and signaling are enriched in human HCC and associated with poor prognosis. Loss of EphA2 suppresses the initiation and growth of HCC both in vitro and in vivo. Furthermore, CRISPR/CAS9-mediated EphA2 inhibition significantly delays tumor development in a genetically engineered murine model of HCC. Mechanistically, we discover that targeting EphA2 suppresses both AKT and JAK1/STAT3 signaling, two separate oncogenic pathways in HCC. We also identify a small molecule kinase inhibitor of EphA2 that suppresses tumor progression in a murine HCC model. Together, our results suggest EphA2 as a promising therapeutic target for HCC.

Keywords:  AKT; EphA2; HCC; JAK1; STAT3

DOI:  https://doi.org/10.1016/j.celrep.2021.108765
Sci Transl Med. 2021 Feb 24. pii: eabc4822. [Epub ahead of print]13(582):

Functional reconstruction of human AML reveals stem cell origin and vulnerability of treatment-resistant MLL-rearranged leukemia.

Bernd B Zeisig, Tsz Kan Fung, Magdalena Zarowiecki, Chiou Tsun Tsai, Huacheng Luo, Boban Stanojevic, Claire Lynn, Anskar Y H Leung, Jan Zuna, Marketa Zaliova, Martin Bornhauser, Malte von Bonin, Boris Lenhard, Suming Huang, Ghulam J Mufti, Chi Wai Eric So.

Chemoresistance remains the major challenge for successful treatment of acute myeloid leukemia (AML). Although recent mouse studies suggest that treatment response of genetically and immunophenotypically indistinguishable AML can be influenced by their different cells of origin, corresponding evidence in human disease is still largely lacking. By combining prospective disease modeling using highly purified human hematopoietic stem or progenitor cells with retrospective deconvolution study of leukemia stem cells (LSCs) from primary patient samples, we identified human hematopoietic stem cells (HSCs) and common myeloid progenitors (CMPs) as two distinctive origins of human AML driven by Mixed Lineage Leukemia (MLL) gene fusions (MLL-AML). Despite LSCs from either MLL-rearranged HSCs or MLL-rearranged CMPs having a mature CD34-/lo/CD38+ immunophenotype in both a humanized mouse model and primary patient samples, the resulting AML cells exhibited contrasting responses to chemotherapy. HSC-derived MLL-AML was highly resistant to chemotherapy and expressed elevated amounts of the multispecific anion transporter ABCC3. Inhibition of ABCC3 by shRNA-mediated knockdown or with small-molecule inhibitor fidaxomicin, currently used for diarrhea associated with Clostridium difficile infection, effectively resensitized HSC-derived MLL-AML toward standard chemotherapeutic drugs. This study not only functionally established two distinctive origins of human LSCs for MLL-AML and their role in mediating chemoresistance but also identified a potential therapeutic avenue for stem cell-associated treatment resistance by repurposing a well-tolerated antidiarrhea drug already used in the clinic.

DOI: https://doi.org/10.1126/scitranslmed.abc4822
EMBO J. 2021 Feb 22. e106065

5-Fluorouracil efficacy requires anti-tumor immunity triggered by cancer-cell-intrinsic STING.

Jingru Tian, Dingyao Zhang, Vadim Kurbatov, Qinrong Wang, Yadong Wang, Dorthy Fang, Lizhen Wu, Marcus Bosenberg, Mandar D Muzumdar, Sajid Khan, Qianjin Lu, Qin Yan, Jun Lu.

  5-Fluorouracil (5-FU) is a widely used chemotherapeutic drug, but the mechanisms underlying 5-FU efficacy in immunocompetent hosts in vivo remain largely elusive. Through modeling 5-FU response of murine colon and melanoma tumors, we report that effective reduction of tumor burden by 5-FU is dependent on anti-tumor immunity triggered by the activation of cancer-cell-intrinsic STING. While the loss of STING does not induce 5-FU resistance in vitro, effective 5-FU responsiveness in vivo requires cancer-cell-intrinsic cGAS, STING, and subsequent type I interferon (IFN) production, as well as IFN-sensing by bone-marrow-derived cells. In the absence of cancer-cell-intrinsic STING, a much higher dose of 5-FU is needed to reduce tumor burden. 5-FU treatment leads to increased intratumoral T cells, and T-cell depletion significantly reduces the efficacy of 5-FU in vivo. In human colorectal specimens, higher STING expression is associated with better survival and responsiveness to chemotherapy. Our results support a model in which 5-FU triggers cancer-cell-initiated anti-tumor immunity to reduce tumor burden, and our findings could be harnessed to improve therapeutic effectiveness and toxicity for colon and other cancers.

Keywords:  5-FU resistance; Dacarbazine; Ifnb; Mb21d1; Tmem173

DOI:  https://doi.org/10.15252/embj.2020106065
Clin Cancer Res. 2021 Feb 25. pii: clincanres.4382.2020. [Epub ahead of print]

Pan-cancer transcriptomic predictors of perineural invasion improve occult histopathological detection.

Jimmy A Guo, Hannah I Hoffman, Stuti Shroff, Peter Chen, Peter G Hwang, Daniel Y Kim, Daniel W Kim, Stephanie W Cheng, Daniel Zhao, Brandon A Mahal, Mohammed Alshalalfa, Andrzej Niemierko, Jennifer Y Wo, Jay S Loeffler, Carlos Fernandez-Del Castillo, Tyler Jacks, Andrew Aguirre, Theodore S Hong, Mari Mino-Kenudson, William L Hwang.

PURPOSE: Perineural invasion (PNI) is associated with aggressive tumor behavior, recurrence, and metastasis, and can influence the administration of adjuvant treatment. However, standard histopathological examination has limited sensitivity in detecting PNI and does not provide insights into its mechanistic underpinnings.EXPERIMENTAL DESIGN: A multi-variate Cox regression was performed to validate associations between PNI and survival in 2029 patients across 12 cancer types. Differential expression and gene set enrichment analysis were used to learn PNI-associated programs. Machine learning models were applied to build a PNI gene expression classifier. A blinded re-review of H&E slides by a board-certified pathologist helped determine whether the classifier could improve occult histopathological detection of PNI.
RESULTS: PNI associated with both poor OS (hazard ratio, 1.73; 95% CI, 1.27-2.36; P < 0.001) and DFS (hazard ratio, 1.79; 95% CI, 1.38-2.32; P < 0.001). Neural-like, pro-survival, and invasive programs were enriched in PNI-positive tumors (Padj < 0.001). Although PNI-associated features likely reflect in part the increased presence of nerves, many differentially-expressed genes mapped specifically to malignant cells from single-cell atlases. A PNI gene expression classifier was derived using random forest and evaluated as a tool for occult histopathological detection. On a blinded H&E re-review of sections initially described as PNI-negative, more specimens were re-annotated as PNI-positive in the high classifier score cohort compared to the low-scoring cohort (P = 0.03, Fisher's exact test).
CONCLUSIONS: This study provides salient biological insights regarding PNI and demonstrates a role for gene expression classifiers to augment detection of histopathological features.

DOI: https://doi.org/10.1158/1078-0432.CCR-20-4382
Nat Med. 2021 Feb 22.

Identification of resistance pathways and therapeutic targets in relapsed multiple myeloma patients through single-cell sequencing.

Yael C Cohen, Mor Zada, Shuang-Yin Wang, Chamutal Bornstein, Eyal David, Adi Moshe, Baoguo Li, Shir Shlomi-Loubaton, Moshe E Gatt, Chamutal Gur, Noa Lavi, Chezi Ganzel, Efrat Luttwak, Evgeni Chubar, Ory Rouvio, Iuliana Vaxman, Oren Pasvolsky, Mouna Ballan, Tamar Tadmor, Anatoly Nemets, Osnat Jarchowcky-Dolberg, Olga Shvetz, Meirav Laiba, Ofer Shpilberg, Najib Dally, Irit Avivi, Assaf Weiner, Ido Amit.

Multiple myeloma (MM) is a neoplastic plasma-cell disorder characterized by clonal proliferation of malignant plasma cells. Despite extensive research, disease heterogeneity within and between treatment-resistant patients is poorly characterized. In the present study, we conduct a prospective, multicenter, single-arm clinical trial (NCT04065789), combined with longitudinal single-cell RNA-sequencing (scRNA-seq) to study the molecular dynamics of MM resistance mechanisms. Newly diagnosed MM patients (41), who either failed to respond or experienced early relapse after a bortezomib-containing induction regimen, were enrolled to evaluate the safety and efficacy of a daratumumab, carfilzomib, lenalidomide and dexamethasone combination. The primary clinical endpoint was safety and tolerability. Secondary endpoints included overall response rate, progression-free survival and overall survival. Treatment was safe and well tolerated; deep and durable responses were achieved. In prespecified exploratory analyses, comparison of 41 primary refractory and early relapsed patients, with 11 healthy subjects and 15 newly diagnosed MM patients, revealed new MM molecular pathways of resistance, including hypoxia tolerance, protein folding and mitochondria respiration, which generalized to larger clinical cohorts (CoMMpass). We found peptidylprolyl isomerase A (PPIA), a central enzyme in the protein-folding response pathway, as a potential new target for resistant MM. CRISPR-Cas9 deletion of PPIA or inhibition of PPIA with a small molecule inhibitor (ciclosporin) significantly sensitizes MM tumor cells to proteasome inhibitors. Together, our study defines a roadmap for integrating scRNA-seq in clinical trials, identifies a signature of highly resistant MM patients and discovers PPIA as a potent therapeutic target for these tumors.

DOI: https://doi.org/10.1038/s41591-021-01232-w
Oncogene. 2021 Feb 24.

Nerve growth factor receptor increases the tumor growth and metastatic potential of triple-negative breast cancer cells.

Renfei Wu, Koukou Li, Mingheng Yuan, Kathy Qian Luo.

Cellular heterogeneity and the lack of metastatic biomarkers limit the diagnosis of and development of therapies for metastatic triple-negative breast cancer (TNBC). Thus, development of new clinically relevant markers is urgently needed. By using RNA-seq analysis, we found that nerve growth factor receptor (NGFR) was highly expressed in metastatic lung clones of MDA-MB-231 cells. This high level of NGFR expression was necessary for TNBC cells to grow into tumor spheres under nonadhesive conditions, resist anoikis, promote primary tumor growth and increase metastasis in mice. NGFR was also expressed at a high level in a greater number of TNBC patients (45%) than non-TNBC patients (23%), enriched in higher grade tumors, and negatively correlated with the overall survival of TNBC patients. Mechanistic analysis indicated that NGFR exerted its prometastatic effects by binding with neurotrophic receptor tyrosine kinase 3 (TrkC) mainly through a ligand-independent manner, which activated the MEK-ERK1-ZEB1 and PI3K-AKT signaling pathways, increased the level of fibronectin, and decreased the expression of PUMA. Notably, we observed that NGFR expression in TrkC-positive metastatic clones reduced cellular sensitivity to anti-Trk therapy. Moreover, WNT family member 5a (WNT5A) and TrkC activated NGFR transcription in a ZEB1-dependent manner. Taken together, this study identified NGFR as a novel driver for transforming TNBC into higher grade metastatic tumors. Our findings provide the basis for the future development of NGFR as a diagnostic and prognostic marker for determining the metastatic potential of TNBC and as a therapeutic target for treating TNBC patients.

DOI: https://doi.org/10.1038/s41388-021-01691-y
Nature. 2020 Feb 27.

Working Scientist podcast: How to get media coverage for your research.

Adam Levy.

DOI: https://doi.org/10.1038/d41586-020-00382-0
Nature. 2020 Feb 28.

Free lists of grants and fellowships around the world available online.

Chris Woolston.



Keywords:  Careers; Databases; Funding

DOI:  https://doi.org/10.1038/d41586-020-00599-z
Cancer Res. 2021 Feb 23. pii: canres.1624.2020. [Epub ahead of print]

Cytoplasmic localization of prostate-specific membrane antigen inhibitors may confer advantages for targeted cancer therapies.

Jessica Matthias, Johann Engelhardt, Martin Schäfer, Ulrike Bauder-Wüst, Philipp T Meyer, Uwe Haberkorn, Matthias Eder, Klaus Kopka, Stefan W Hell, Ann-Christin Eder.

Targeted imaging and therapy approaches based on novel prostate-specific membrane antigen (PSMA) inhibitors have fundamentally changed the treatment regimen of prostate cancer. However, the exact mechanism of PSMA inhibitor internalization has not yet been studied, and the inhibitors' subcellular fate remains elusive. Here we investigated the intracellular distribution of peptidomimetic PSMA inhibitors and of PSMA itself by stimulated emission depletion (STED) nanoscopy, applying a novel non-standard live cell staining protocol. Imaging analysis confirmed PSMA cluster formation at the cell surface of prostate cancer cells and clathrin-dependent endocytosis of PSMA inhibitors. Following the endosomal pathway, PSMA inhibitors accumulated in prostate cancer cells at clinically relevant time points. In contrast to PSMA itself, PSMA inhibitors were found to eventually distribute homogeneously in the cytoplasm, a molecular condition that promises benefits for treatment as cytoplasmic and in particular perinuclear enrichment of the radionuclide carriers may better facilitate the radiation-mediated damage of cancerous cells. This study is the first to reveal the subcellular fate of PSMA/PSMA inhibitor complexes at the nanoscale and aims to inspire the development of new approaches in the field of prostate cancer research, diagnostics, and therapeutics.

DOI: https://doi.org/10.1158/0008-5472.CAN-20-1624
Mol Cell. 2021 Feb 10. pii: S1097-2765(21)00058-7. [Epub ahead of print]

DNA hypomethylating agents increase activation and cytolytic activity of CD8+ T cells.

Helen Loo Yau, Emma Bell, Ilias Ettayebi, Felipe Campos de Almeida, Giselle M Boukhaled, Shu Yi Shen, David Allard, Beatriz Morancho, Sajid A Marhon, Charles A Ishak, Isabela M Gonzaga, Tiago da Silva Medina, Rajat Singhania, Ankur Chakravarthy, Raymond Chen, Parinaz Mehdipour, Sandra Pommey, Christian Klein, Gustavo P Amarante-Mendes, David Roulois, Joaquín Arribas, John Stagg, David G Brooks, Daniel D De Carvalho.

  We demonstrate that DNA hypomethylating agent (HMA) treatment can directly modulate the anti-tumor response and effector function of CD8+ T cells. In vivo HMA treatment promotes CD8+ T cell tumor infiltration and suppresses tumor growth via CD8+ T cell-dependent activity. Ex vivo, HMAs enhance primary human CD8+ T cell activation markers, effector cytokine production, and anti-tumor cytolytic activity. Epigenomic and transcriptomic profiling shows that HMAs vastly regulate T cell activation-related transcriptional networks, culminating with over-activation of NFATc1 short isoforms. Mechanistically, demethylation of an intragenic CpG island immediately downstream to the 3' UTR of the short isoform was associated with antisense transcription and alternative polyadenylation of NFATc1 short isoforms. High-dimensional single-cell mass cytometry analyses reveal a selective effect of HMAs on a subset of human CD8+ T cell subpopulations, increasing both the number and abundance of a granzyme Bhigh, perforinhigh effector subpopulation. Overall, our findings support the use of HMAs as a therapeutic strategy to boost anti-tumor immune response.

Keywords:  CD8+ T cells; DNA methylation; NFATc1; cytolytic activity; decitabine; epigenetic therapy; granzyme B; killing potential

DOI:  https://doi.org/10.1016/j.molcel.2021.01.038
Nat Commun. 2021 02 24. 12(1): 1274

Spatially mapped single-cell chromatin accessibility.

Casey A Thornton, Ryan M Mulqueen, Kristof A Torkenczy, Andrew Nishida, Eve G Lowenstein, Andrew J Fields, Frank J Steemers, Wenri Zhang, Heather L McConnell, Randy L Woltjer, Anusha Mishra, Kevin M Wright, Andrew C Adey.

High-throughput single-cell epigenomic assays can resolve cell type heterogeneity in complex tissues, however, spatial orientation is lost. Here, we present single-cell combinatorial indexing on Microbiopsies Assigned to Positions for the Assay for Transposase Accessible Chromatin, or sciMAP-ATAC, as a method for highly scalable, spatially resolved, single-cell profiling of chromatin states. sciMAP-ATAC produces data of equivalent quality to non-spatial sci-ATAC and retains the positional information of each cell within a 214 micron cubic region, with up to hundreds of tracked positions in a single experiment. We apply sciMAP-ATAC to assess cortical lamination in the adult mouse primary somatosensory cortex and in the human primary visual cortex, where we produce spatial trajectories and integrate our data with non-spatial single-nucleus RNA and other chromatin accessibility single-cell datasets. Finally, we characterize the spatially progressive nature of cerebral ischemic infarction in the mouse brain using a model of transient middle cerebral artery occlusion.

DOI: https://doi.org/10.1038/s41467-021-21515-7