Determination of carcinogenesis-related target microRNAs in the lung cancer cell model and investigation of its functional effect via RNA interference

Objective: Lung cancer is one of the leading causes of cancer-related deaths worldwide. The development of resistance to conventional treatments such as chemotherapy and radiotherapy, as well as limited success in treating metastatic disease, contribute to poor clinical outcomes. This situation necessitates the development of more effective and targeted therapeutic strategies for lung cancer. Gene silencing holds significant potential in cancer therapy by enabling spesific interventions targeting molecular pathways. In this study, it is aimed to identify target microRNAs associated with carcinogenesis in a lung cancer cell model and to investigate the functional effects of the targets through RNA interference. Material and Methods: In this study, candidate miRNAs with potentital therapeutic relevance were initally identified using the miTED database. The expression level of the selected miRNA was validated using qPCR in A549 (lung cancer) and T2A (healthy) cell lines. Subsequently, anti-miRNA (miRNA inhibitor transfection) was used to silence the selected target miRNA in both healthy and lung cancer models. The effects of this intervention on cell viability, apoptosis, and sensitivity to the conventional chemotherapeutic agent cisplatin were evaluated using cytotoxicity analysis, Annexin V (apoptosis analysis), and cell cycle analysis. Results: In silico analyses from the miTED database revealed the miR-146a-3p was expressed 5.19-fold higher in cancer tissues compared to normal tissues. Compared to healthy cell, miR 146a-3p expression was found to be 4.86-fold higher in the A549 cell line. Silencing of miR 146a-3p in A549 cell reduced cell viability by 19.4% and increased the rate of apoptosis by approximately 20%. When combined with cisplatin treatment, and additional 11% increase in apoptotic cells was observed, indicating enchanced treatment sensitivity. Cell cycle analyses xv revealed that this combination significantly accumulated A549 cells in the G2/M phase and induced arrest at the pre-mitotic checkpoint. Conclusion: These findings suggest that miR-146a-3p may function as an oncogenic miRNA in lung cancer and could servse as a potential molecular target to enhance sensitivity to cisplatin therapy.