Iranian Biomedical Journal

A Novel Approach to Overcome Cisplatin Resistance in Ovarian Cancer: Revealing the Synergistic Potential of Quercetin-Loaded Solid Lipid Nanoparticles

Ovarian cancer (OC) remains the leading cause of mortality among gynecological cancers, mainly because of resistance to platinum-based chemotherapy, particularly cisplatin. This study investigated the potential of quercetin (QU)-loaded solid lipid nanoparticles (SLNs) to address cisplatin resistance in OC cells. The efficacy of QU-SLN was assessed in vitro on the cisplatin-resistant SK-OV-3 and cisplatin-sensitive A2780s human OC cell lines. Various assays, including cytotoxicity, cell viability, clonogenicity, flow cytometry, quantitative RT-PCR, and wound healing assays, evaluated the combined effects of QU and QU-SLN with cisplatin on cell viability, apoptosis, gene expression levels related to cisplatin resistance, and cell migration. Combining QU-SLN with cisplatin resulted in significantly reduced cell viability and colony formation, accompanied by increased apoptotic rates compared to each treatment alone. Moreover, there was a notable reduction in the expression level of genes associated with cisplatin resistance, particularly ABCG2, MT-2A, GST-pi, and XIAP, in the combined treatment. Wound healing assays indicated that the QU-SLN and cisplatin combination severely impaired OC cell motility compared to cisplatin monotherapy. QU-SLN and cisplatin combination enhances the therapeutic response in cisplatin-resistant OC cells. By reducing cell proliferation, promoting apoptosis, and downregulating drug resistance genes, QU-SLN might present a promising strategy to improve treatment outcomes for OC patients resistant to cisplatin.

Nona-Arginine Mediated Anti-E6 ShRNA Delivery Suppresses the Growth of Hela Cells in vitro

The E6 oncoprotein of HPV plays a crucial role in promoting cell proliferation and inhibiting apoptosis, leading to tumor growth. Non-viral vectors such as nona-arginine (R9) peptides have shown to be potential as carriers for therapeutic molecules. This study aimed to investigate the efficacy of nona-arginine in delivering E6 shRNA and suppressing the E6 gene of HeLa cells in vitro. HeLa cells carrying E6 gene were treated with a complex of nona-arginine and E6 shRNA. The complex was evaluated using gel retardation assay and FESEM microscopy. The optimal N/P ratio for R9 peptide to transfect HeLa cells with luciferase gene was determined. Relative real-time PCR was used to evaluate the efficiency of mRNA suppression efficiency for E6 shRNA, while the effect of E6 shRNA on cell viability was measured using an MTT assay. The results indicated that R9 efficiently binds to shRNA and effectively transfects E6 shRNA complexes at N/P ratios greater than 30. Transfection with R9 and PEI complexes resulted in a significant toxicity compared to the scrambled plasmid, indicating selective toxicity for HeLa cells. Real-time PCR confirmed the reduction of E6 mRNA expression levels in the cells transfected with anti-E6 shRNA. The study suggests that R9 is a promising non-viral gene carrier for transfecting E6 shRNA in vitro, with significant transfection efficiency and minimal toxicity.

EGFR Blockade Reverses Cisplatin Resistance in Human Epithelial Ovarian Cancer Cells

Epithelial ovarian cancer (EOC) is one of the most lethal gynecological malignancy worldwide. Although the majority of EOC patients achieve clinical remission after induction therapy, over 80% relapse and succumb to the chemoresistant disease. Previous investigations have demonstrated the association of epidermal growth factor receptor (EGFR) with resistance to cytotoxic chemotherapies, hormone therapy, and radiotherapy in the cancers. These studies have highlighted the role of EGFR as an attractive therapeutic target in cisplatin-resistant EOC cells. The human ovarian cell lines (SKOV3 and OVCAR3) were cultured according to ATCC recommendations. The MTT assay was used to determine the chemosensitivity of the cell lines in exposure to cisplatin and erlotinib. The qRT-PCR was applied to analyze the mRNA expression of the desired genes. Erlotinib in combination with cisplatin reduced the cell proliferation in the chemoresistant EOC cells in comparison to monotherapy of the drugs (p < 0.05). Moreover, erlotinib/cisplatin combination synergistically decreased the expression of anti-apoptotic and also increased pro-apoptotic genes expression (p < 0.05). Cisplatin alone could increase the expression of multi-drug resistant genes. The data suggested that EGFR and cisplatin drive chemoresistance in the EOC cells through MEKK signal transduction as well as through EGFR/MEKK pathways in the cells, respectively. Our findings propose that EGFR is an attractive therapeutic target in chemoresistant EOC to be exploited in translational oncology, and erlotinib/cisplatin combination treatment is a potential anti-cancer approach to overcome chemoresistance and inhibit the proliferation of the EOC cells.

Anticancer Effect of Enterococcus faecium, Isolated from Vaginal Fluid, on Ovarian Cancer Cells

Given the association between cervicovaginal microbiota and OVC, we investigated the effect of Enterococcus faecium conditioned medium (CM) on OVC (Caov-4) cells. CM was obtained from the bacterium E. faecium isolated from the vagina of healthy women. The Caov-4 cells were treated with varying concentrations of CM that comprised co-cultured bacteria with 0.2, 0.5, 1, 1.5, and 2 OD for 12, 24, and 48 h. The apoptosis and growth of cancer cells were evaluated by 4′,6-diamidino-2-phenylindole (DAPI) staining, flow cytometry, and DNA laddering assay. Moreover, the expression of PTEN, BAX, BCL2, and AKT1 genes were analyzed using real-time PCR. The CM at a concentration of 0.5 OD from the cultured bacteria and incubation time of 48 h showed the highest negative effect on the viability of cancer cells. The CM treatment increased DNA fragmentation and also induced apoptosis in Caov-4 cells. Interestingly, CM could decrease the expression of proapoptotic genes were less, while antiapoptotic genes were more than fluorouracil in the presence of CM. CM of human-derived E. faecium could have an anticancer effect on OVC cells in a concentration- and time-dependent manner. This study demonstrated that E. faecium secretes anticancer substances into the CM, which could directly affect the viability and apoptosis of cancer cells.