Dan Zi

STUB1 suppresses paclitaxel resistance in ovarian cancer through mediating HOXB3 ubiquitination to inhibit PARK7 expression

Paclitaxel (PTX) is a first-line drug for ovarian cancer (OC) treatment. However, the regulatory mechanism of STUB1 on ferroptosis and PTX resistance in OC remains unclear. Genes and proteins levels were evaluated by RT-qPCR, western blot and IHC. Cell viability and proliferation were measured by CCK-8 and clone formation. The changes of mitochondrial morphology were observed under a transmission electron microscope (TEM). Reactive oxygen species (ROS), iron, malondialdehyde (MDA) and glutathione (GSH) were measured using suitable kits. The interactions among STUB1, HOXB3 and PARK7 were validated using Co-IP, and dual luciferase reporter assay. Our study found that STUB1 was decreased and PARK7 was increased in tumor tissue, especially from chemotherapy resistant ovarian cancer tissue and resistant OC cells. STUB1 overexpression or PARK7 silencing suppressed cell growth and promoted ferroptosis in PTX-resistant OC cells, which was reversed by HOXB3 overexpression. Mechanistically, STUB1 mediated ubiquitination of HOXB3 to inhibit HOXB3 expression, and HOXB3 promoted the transcription of PARK7 by binding to the promoter region of PARK7. Furthermore, STUB1 overexpression or PARK7 silencing suppressed tumor formation in nude mice. In short, STUB1 promoted ferroptosis through regulating HOXB3/PARK7 axis, thereby suppressing chemotherapy resistance in OC.

Eukaryotic Initiation Factor 3C Can Affect the Proliferation and Invasion of Ovarian Cancer by Regulating the p53 Signalling Pathway

Background: Eukaryotic Initiation Factor 3C (EIF3C) represents a pivotal translational initiation factor in eukaryotes and has been shown to facilitate the progression of various neoplasms. However, its mechanistic role in ovarian cancer remains elusive. Methods: In this research, the expression of EIF3C in ovarian cancer tissues was investigated using immunohistochemistry. In addition, the assessments were made on changes in cellular proliferation, invasion, and apoptotic abilities by reducing the expression of EIF3C in ovarian cancer cells. By utilizing microarray analysis, a comparison was performed between the downregulated EIF3C group and the control group of ovarian cancer cells, revealing the genes that were expressed differently. Furthermore, the signalling pathways associated with cellular proliferation were validated. The functional role of EIF3C in vivo was investigated using a xenograft tumour model. Results: The immunohistochemical analysis showed that elevated levels of EIF3C are linked to a negative prognosis in patients with ovarian cancer. Suppression of EIF3C greatly hindered the growth and spread of SK-OV-3 and HO-8910 cells while enhancing cellular programmed cell death. Following KEGG and GSEA enrichment analyses of differentially expressed genes, the p53 signalling pathway was found to be associated with EIF3C. Suppression of EIF3C resulted in the upregulation of the p53 signalling pathway, leading to the inhibition of cell proliferation and invasion and the promotion of apoptosis. In vivo experiments demonstrated that EIF3C knockdown suppressed the growth of subcutaneous tumours in nude mice. Conclusion: There is a correlation between overexpression of EIF3C in tumour tissues of ovarian cancer patients and this is associated with a poorer prognosis. By influencing the p53 signaling pathway, EIF3C facilitates the growth and infiltration of cells in ovarian cancer.