Investigation of the effect of amniotic fluid-derived exosomes on primary lung cancer cells

Lung cancer is the most common cause of cancer deaths worldwide. Despite treatment methods such as surgery, chemotherapy, and radiotherapy, five-year survival rates for lung cancer are low. In recent years, immunotherapy approaches have gained popularity and hold great promise in cancer treatment. Exosomes are small vesicles of endosomal origin released by cells in response to various physiological and pathological stimuli. Recent studies have shown that exosomes have immunomodulatory effects in the tumor microenvironment and may be used as immunotherapeutic agents in certain types of cancer. In this work, primary non-small cell lung cancer (NSCLC) cells and primary bronchial epithelial cells were treated in vitro with exosomes extracted from amniotic fluid. Characterization of amniotic fluid-derived exosomes was performed using Bicinchoninic Acid (BCA), Nanoparticle Tracking Analysis (NTA), and Transmission Electron Microscopy (TEM), and amniotic fluid-derived exosomes were applied to primary lung cells. The effective dose on primary lung cells was determined using the MTT method, and migration testing, apoptotic effects, cell cycle testing, and immunocytochemistry (ICC) were performed to analyze the expression levels of Bax, Bcl-2, Ki-67, Caspase-3, and Caspase-9 proteins. Amniotic fluid-derived exosomes were found to reduce tumor cell viability in a dose- and time-dependent manner, while increasing bronchial cell viability. In the Annexin V apoptosis assay, exosomes were observed to induce early apoptosis in tumor cells and cause an increase in bronchial cell count. Furthermore, an increase was observed in the apoptosis markers Bax, Caspase-3, and Caspase-9 in tumor cells, while a decrease was observed in the anti-apoptotic marker Bcl-2 and the proliferation marker Ki-67. In bronchial cells, no changes were observed in Caspase-3 and Caspase-9, while increases were seen in Bcl-2 and Ki-67, and a decrease was observed in Bax. Taken together, these results indicate that exosomes derived from amniotic fluid selectively suppress the growth of lung cancer cells while supporting the viability of normal cells.