bims-merabr 2024-11-10 papers

Drug Dev Res. 2024 Nov;85(7): e70004

Knockdown of ENO1 promotes autophagy dependent-ferroptosis and suppresses glycolysis in breast cancer cells via the regulation of CST1.

Guoliang Huang, Lian Lu, Yuhong You, Jie Li, Kaixiang Zhang.

Autophagy-dependent ferroptosis and glycolysis play a significant role in tumor development. α-Enolase (ENO1), a glycolytic enzyme, has been demonstrated to function as a crucial modulator in breast cancer (BC). However, the specific mechanism by which ENO1 influences the ferroptosis and glycolysis of BC remains unclear. qRT-PCR, along with western blot analysis was applied to investigate ENO1 and cystatin SN (CST1) expression in BC cells. Glycolysis level was measured by extracellular acidification rate (ECAR), lactate production, glucose consumption, and western blot analysis. Ferroptosis was evaluated by iron and lipid peroxidation assay, DCFH-DA staining, and western blot analysis. Immunofluorescence, together with western blot analysis was adopted for assessing cell autophagy and mTOR signaling pathway. Cell apoptosis and Ki67 level were measured by TUNEL and immunohistochemistry, respectively. ENO1 had abundant existence in BC cell lines. ENO1 silencing inhibited glycolysis but promoted ferroptosis and autophagy. In addition, autophagy inhibitor 3-MA reversed the impacts of ENO1 silencing on glycolysis and ferroptosis. Meanwhile, mTOR activator MHY1485 demonstrated opposing effects on autophagy. Moreover, CST1 could be extensively found in BC cell lines, and its overexpression reversed the effects of ENO1 silencing on glycolysis and ferroptosis. In vivo experiments illustrated that ENO1 deletion suppressed BC tumor growth, increased the apoptosis rate, restrained cell proliferation, and glycolysis, but promoted ferroptosis and autophagy, as well as reducing CST1 and mTOR signaling. To sum up, ENO1 silencing mediated a utophagy-dependent ferroptosis and glycolysis in BC cells by regulating CST1.

Keywords: breast cancer; cystatin SN; ferroptosis; glycolysis; α‐enolase

DOI: https://doi.org/10.1002/ddr.70004

Mol Carcinog. 2024 Nov 06.

ZNF480 Accelerates Chemotherapy Resistance in Breast Cancer by Competing With TRIM28 and Stabilizing LSD1 to Upregulate the AKT-GSK3β-Snail Pathway.

Xiaowen Ma, Yufeng Jiang, Hangqi Zhao, Yusong Qiu, Zhijian Liu, Xiupeng Zhang, Mingwei Fan, Yong Zhang, Yue Zhang.

Zinc finger protein 480 (ZNF480) may interact with lysine-specific demethylase 1 (LSD1), which is highly expressed in many malignant tumors; however, ZNF480 expression has not previously been investigated in breast cancer. Therefore, we explored the expression and molecular mechanisms of ZNF480 in breast cancer. According to public databases and immunohistochemical staining analysis, ZNF480 is highly expressed in the tissue of patients with breast cancer, and ZNF480 expression is positively correlated with advanced TNM stage (p = 0.036), lymph node metastasis (p = 0.012), and poor prognosis (p = 0.005). ZNF480 overexpression enhances breast cancer cell proliferation, migration, and stemness by activating AKT-GSK3β-Snail signaling both in vitro and in vivo. Moreover, ZNF480 binds to LSD1 through its KRAB domain, thereby activating AKT signaling. Mass spectrometry and co-immunoprecipitation revealed that ZNF480 abrogates ubiquitination degradation and subsequently stabilizes LSD1 through competitive binding with TRIM28. Ipragliflozin was identified as a small-molecule inhibitor of ZNF480 and LSD1 interaction that may block breast cancer progression. Moreover, ZNF480 expression was significantly higher in treatment-resistant patients than in treatment-sensitive patients. Thus, ipragliflozin may neutralize neoadjuvant chemotherapy resistance induced by ZNF480 overexpression. Overall, elevated ZNF480 expression is positively associated with poor patient outcomes. Mechanistically, ZNF480 accelerates proliferation and neoadjuvant chemotherapy resistance in breast cancer cells via the AKT-GSK3β-Snail pathway by interacting with and stabilizing LSD1 in a competitive manner within TRIM28. This research has implications for developing targeted drugs against chemotherapy resistance in breast cancer.

Keywords: Akt; LSD1; ZNF480; breast cancer; chemotherapy

DOI: https://doi.org/10.1002/mc.23837

Clin Breast Cancer. 2024 Sep 26. pii: S1526-8209(24)00265-9. [Epub ahead of print]

RBM15 Drives Breast Cancer Cell Progression and Immune Escape via m6A-Dependent Stabilization of KPNA2 mRNA.

Hu Wang, Yu Cao, Li Zhang, Qian Zhao, Shuangjian Li, Dan Li.

BACKGROUND: Breast cancer is the most frequently diagnosed cancer among women worldwide with high morbidity and mortality. Previous studies have indicated that RNA-binding motif protein-15 (RBM15), an N6-methyladenosine (m6A) writer, is implicated in the growth of breast cancer cells. Herein, we aimed to explore the function and detailed mechanism of RBM15 in breast cancer.
METHODS: In this research, UALCAN databases were applied to analyze the expression of RBM15 or Karyopherin-2 alpha (KPNA2) in BRCA. RBM15 and KPNA2 mRNA levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR) assay. RBM15, KPNA2, and Programmed cell death ligand 1 (PD-L1) protein levels were measured using western blot. Cell proliferation, migration, and invasion were assessed using 5-ethynyl-2'-deoxyuridine (EdU) and Transwell assays. The biological role of RBM15 on breast cancer tumor growth was verified using the xenograft tumor model in vivo. Effects of breast cancer cells on the proliferation and apoptosis of CD8+ T cells were analyzed using flow cytometry. Interaction between RBM15 and KPNA2 was validated using methylated RNA immunoprecipitation (MeRIP) and dual-luciferase reporter assays.
RESULTS: RBM15 and KPNA2 were highly expressed in breast cancer tissues and cell lines. Furthermore, RBM15 silencing might suppress breast cancer cell proliferation, migration, invasion, and lymphocyte immunity in vitro, as well as block tumor growth in vivo. At the molecular level, RBM15 might improve the stability and expression of KPNA2 mRNA via m6A methylation.
CONCLUSION: RBM15 might contribute to the malignant progression and immune escape of breast cancer cells partly by modulating the stability of KPNA2 mRNA, providing a promising therapeutic target for breast cancer.

Keywords: CD8(+) T cells; Cancer immunotherapy; Methyltransferases; PD-L1; Proliferation

DOI: https://doi.org/10.1016/j.clbc.2024.09.006

Breast Cancer Res. 2024 Nov 06. 26(1): 155

PTPN20 promotes metastasis through activating NF-κB signaling in triple-negative breast cancer.

Xiaoxiao Zuo, Xiaohan Zhao, Xiaofei Zhang, Qingyuan Li, Xingyu Jiang, Shumei Huang, Xuwei Chen, Xiangfu Chen, Weihua Jia, Hequn Zou, Dongni Shi, Xueke Qian.

BACKGROUND: Cancer metastasis remains a major challenge in the clinical management of triple-negative breast cancer (TNBC). The NF-κB signaling pathway has been implicated as a crucial factor in the development of metastases, but the underlying molecular mechanisms remain largely unclear.
METHODS: PTPN20 expression was evaluated using data from the Sweden Cancerome Analysis Network-Breast and The Cancer Genome Atlas database, as well as by western blotting and immunohistochemistry in 88 TNBC patients. The ability of PTPN20 to activate NF-κB was assessed by luciferase reporter assays. The effects of PTPN20 overexpression and knockdown via short hairpin RNA were examined in TNBC cell lines by wound healing and transwell matrix penetration assays. Additionally, we analyzed the growth and metastasis abilitiy of 4T1 xenograft tumors in nude mice.
RESULTS: PTPN20 levels were elevated in TNBC cell lines and patient samples compared to controls, and higher protein levels correlated with metastasis-free survival. Overexpression of PTPN20 enhanced migration and invasion in vitro, and promoted lung metastasis in vivo. Our finding revealed that PTPN20 activates NF-κB signaling by dephosphorylating p65 at Ser468, preventing its binding to COMMD1, thereby protecting p65 from degradation. Downregulation of PTPN20 effectively inhibit, while p65 S468A mutant restored the migratory and invasive abilities of TNBC cells.
CONCLUSIONS: Collectively, our results demonstrate that PTPN20 plays a critical role in TNBC metastasis through the activation of NF-κB signaling. We propose that PTPN20 may serve as a novel prognostic marker and potential therapeutic target for the treatment of TNBC.

Keywords: PTPN20; TNBC; metastasis; p65

DOI: https://doi.org/10.1186/s13058-024-01910-w

Sci Rep. 2024 11 07. 14(1): 27029

Adipocytes reprogram the proteome of breast cancer cells in organotypic three-dimensional cell cultures.

Karla Tovar-Hernández, Yarely M Salinas-Vera, Ángeles Carlos-Reyes, Alejandra P García-Hernández, Laurence A Marchat, Gilberto Mandujano-Lázaro, Emmanuel Ríos-Castro, Andrea Velasco-Suárez, Ivonne Mendez-Gómez, Ángeles C Tecalco-Cruz, Eloisa Ibarra-Sierra, César López-Camarillo.

While epidemiological evidence has long linked obesity with an increased risk of breast cancer, the intricate interactions between adipocytes and cancer cells within the tumor microenvironment remain largely uncharted territory. The use of organotypic three-dimensional (3D) cell cultures that more accurately mimic the spatial architecture of tumors represents an innovative approach to this complex issue. In the present study, we investigated the effects of adipocytes on the proteome of Hs578t breast cancer cells cultured in a 3D microenvironment. Using different treatments, we rigorously optimized the experimental conditions to induce the optimal differentiation of 3T3-L1 fibroblasts into mature adipocytes. Then, we grow the Hs578t cells in a simulated microenvironment using an on-top model for organotypic 3D cultures. Our data showed that cancer cells formed 3D stellate-like architectures when grown over an extracellular matrix proteins-enriched scaffold for 48 h. Proteomic profiling using LC-MS/MS mass spectrometry of Hs578t cells grown in 3D conditions with or without the adipocyte-enriched culture discovered 916 unique proteins. Of these, 605 showed no significant changes in abundance, whereas 87 proteins were significantly upregulated and 224 downregulated after interaction with fat cells (p < 0.05, FC > 2.0). Bioinformatic analysis of upregulated proteins indicated that the most enriched GO terms and molecular functions were related to lipids transport, cell differentiation, hypoxia response, and cell junctions. In addition, several modulated proteins have been previously associated with breast cancer progression. Interestingly, lipid transport proteins, including PITPNM2, ATP2C1, ABCA12, HDLBP, and APOB, showed perturbations in their expression, which were also associated with low overall survival in breast cancer patients. Functional studies showed that the knockdown of apolipoprotein B (APOB) expression in Hs578t cells reduced the size of 3D cellular structures. Moreover, APOB-knocked cells cocultured with adipocytes for 48 h exhibited a significant decrease of intracellular lipids, whereas an increase in the adipocytes was found. Our results indicate that the 3D microenvironment and the adipocytes crosstalk reprogram the proteome of breast cancer cells. These data help us understand the environmental effects in gene expression and contribute to discovering novel tumor proteins with potential intervention in breast cancer therapy.

Keywords: 3D cultures; Adipocytes; Breast cancer; Lipids-transport proteins; Proteomics

DOI: https://doi.org/10.1038/s41598-024-76053-1

Clin Breast Cancer. 2024 Oct 16. pii: S1526-8209(24)00280-5. [Epub ahead of print]

USP4/CARM1 Axis Promotes the Malignant Transformation of Breast Cancer Cells by Upregulating SLC7A11 Expression.

Xin Li, Changjiao Yan, Jun Yun, Xin Xu, Hongliang Wei, Xiaolong Xu, Yike Li, Jun Yi.

BACKGROUND: Coactivator associated arginine methyltransferase 1 (CARM1) has been identified as a regulator of breast cancer (BC) progression, yet the underlying mechanisms remain elusive.
METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the mRNA expression of CARM1 and solute carrier family 7 member 11 (SLC7A11). Western blotting was conducted to detect the protein expressions of CARM1, ubiquitin specific peptidase 4 (USP4), and SLC7A11. Cell viability, apoptosis, invasion, and migration were evaluated using CCK-8 assay, flow cytometry, transwell assay, and wound-healing assay, respectively. Fe2+ and GSH levels were determined by colorimetric assay. Fluorescence microscopy and flow cytometry were utilized to quantify reactive oxygen species (ROS) production. Co-immunoprecipitation (Co-IP) assay and cycloheximide (CHX) assay were performed to investigate the relationship between USP4 and CARM1. Xenograft mouse model assay was conducted to validate the effects of USP4 silencing and CARM1 overexpression on the malignant phenotypes of BC cells.
RESULTS: CARM1 and SLC7A11 expression was upregulated in BC tissues and cells when compared with normal breast tissues and cells. Silencing of CARM1 inhibited the malignant phenotypes of BC cells, including decreased cell viability, invasion, and migration and increased cell apoptosis, ferroptosis and oxidative stress. In addition, USP4 stabilized CARM1 protein expression through its deubiquitinating activity. Overexpression of CARM1 attenuated the effects of USP4 silencing in both MCF-7 and MDA-MB-231 cells. Furthermore, silencing of CARM1 reduced SLC7A11 expression, and SLC7A11 overexpression relieved the CARM1 silencing-induced effects. Further, overexpression of CARM1 counteracted the inhibitory effects of USP4 silencing on tumor growth in vivo.
CONCLUSION: Our study reveals a novel mechanism by which USP4-dependent CARM1 promotes the malignant growth of BC cells by interacting with SLC7A11. Targeting this axis may provide a potential therapeutic strategy for BC.

Keywords: BC; CARM1; Deubiquitination; Malignancy; Phenotypes; SLC7A11; Tumor; USP4

DOI: https://doi.org/10.1016/j.clbc.2024.10.001