In MCF-7 and MDA-MB-231 cells, TBX20 overexpression significantly enhanced cell proliferation, migration, invasion, and resistance to doxorubicin, while suppressing the expression of mitophagy-related proteins LC3-II/LC3-I, PINK1, and BNIP3.
Abstract
This study aimed to investigate the role and mechanism of T-box transcription factor 20 (TBX20) in doxorubicin resistance in breast cancer cells. RNA-seq data from breast cancer samples in the TCGA database were analyzed. Lentiviral vectors were used to establish TBX20 overexpression and silencing models in MCF-7 and MDA-MB-231 cells. Gene and protein expression were detected by qPCR and Western blot, respectively. Cell viability and the half-maximal inhibitory concentration of doxorubicin were measured using the CCK-8 assay. Apoptosis, migration, and invasion were analyzed by flow cytometry, wound healing assay, and Transwell assay. Mitophagy levels were assessed via immunofluorescence staining and western blotting. ChIP and dual-luciferase reporter assays were performed to validate the transcriptional regulation of ABCC1 by TBX20. Results showed that TCGA data analysis revealed a high expression of TBX20 in breast cancer tissues, which was positively correlated with ABCC1 expression. In MCF-7 and MDA-MB-231 cells, TBX20 overexpression significantly enhanced cell proliferation, migration, invasion, and resistance to doxorubicin, while suppressing the expression of mitophagy-related proteins LC3-II/LC3-I, PINK1, and BNIP3. ChIP and dual-luciferase reporter assays confirmed that TBX20 directly binds to and activates the ABCC1 promoter. Silencing of ABCC1 or restoration of mitophagy by CCCP reversed TBX20 overexpression‑induced doxorubicin resistance. TBX20 enhances the resistance of breast cancer cells to doxorubicin by transcriptionally upregulating ABCC1 and is correlated with the suppression of mitophagy.
GLUT10 is highly expressed in breast cancer and mediates cisplatin resistance by regulating ROS levels, suggesting it may serve as a novel therapeutic target for reversing drug resistance in breast cancer.
Y. Wang, Y. Cai, T. X. Yi et al.· Zhonghua zhong liu za zhi [C...· 0 citations
Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by significant intratumoral heterogeneity and poor prognosis. Our study identified Establishment Factor-Like Protein 2 (EFO2) as a key oncogenic driver of TNBC progression. Using GEO datasets, we identified differentially expressed genes in TNBC. Functional roles of EFO2 were assessed via knockdown in human (MDA-MB-231, HCC1937) and mouse (4 T1, EMT6) TNBC cells, examining proliferation, glycolysis, and co-culture with CD8⁺ T cells. In vivo tumor growth was evaluated. Molecular mechanisms were investigated through co-immunoprecipitation, mutagenesis, luciferase reporter, and ChIP-qPCR assays. We observed that EFO2 was highly expressed in TNBC tissues, and this high expression correlated with shorter patient survival. Functional experiments showed that EFO2 knockdown suppressed tumor growth and proliferation both in vitro and in vivo. Furthermore, EFO2 knockdown inhibited glycolysis, as evidenced by decreased glucose uptake, ATP production, and lactate production. Moreover, EFO2 deficiency enhanced CD8⁺ T cell-mediated cytotoxicity against TNBC cells. Mechanistically, we demonstrated that EFO2 promoted the acetylation of Upstream Transcription Factor 1 (USF1), thereby enhancing transcriptional upregulation of the SLC2A1 promoter, a key glucose transporter. This EFO2/USF1/SLC2A1 signaling axis accelerated glycolysis in TNBC cells, which concurrently sustained tumor proliferation and impaired CD8⁺ T cell effector function, reducing TNBC cell susceptibility to T cell-mediated killing. Our findings identify a novel EFO2/USF1/SLC2A1 signaling axis that modulates glycolytic metabolism and CD8⁺T cell cytotoxicity, positioning EFO2 as a promising therapeutic target for TNBC treatment.
Lin Jia, Liru Li, Junning Peng et al.· Biochemical Pharmacology· 0 citations
BACKGROUND
Epithelial-mesenchymal transition (EMT) and glycolysis contribute to breast cancer (BC). However, the molecular mechanisms underlying these processes require further investigation.
METHODS
Gene abundance was determined using RT-qPCR, Western blotting, and IHC. Cell viability and migration were evaluated using CCK-8 and scratch tests. Co-IP was performed to confirm the RNF125-HDAC1 interaction. Glycolysis-related indicators were detected using commercial kits, the Seahorse XF assay, and Western blotting. The enrichment of H3K27ac in the PGM5 promoter was determined using ChIP.
RESULTS
In BC samples, RNF125 and PGM5 levels were downregulated, whereas HDAC1 expression was upregulated. Upregulation of RNF125 inhibited EMT and glycolysis in BC cells, suppressed tumor growth in subcutaneous tumor-bearing mouse models, and reduced lung metastasis in mice; these effects were counteracted by HDAC1 overexpression. Similarly, PGM5 overexpression suppressed EMT and glycolysis in BC cells; however, this suppression was blocked by HDAC1 overexpression or RNF125 knockdown. Mechanistically, RNF125 promoted HDAC1 ubiquitination, leading to its proteasomal degradation. Moreover, HDAC1 reduced PGM5 expression by inhibiting H3K27ac enrichment at the PGM5 promoter.
CONCLUSION
RNF125 suppressed EMT and glycolysis in BC cells and delayed tumor growth in subcutaneous tumor-bearing mouse models, as well as lung metastasis in mice through modulation of the HDAC1/PGM5 axis.
Yanhong Wei, Zhaohui Tang, P. Luo et al.· Epigenomics· 0 citations