Akademik Veri Yönetim Sistemi
Cyprus Journal of Medical Sciences, cilt.10, sa.1, ss.78-82, 2025 (ESCI)
BACKGROUND/AIMS: Exosomes are small vesicles that transport bioactive molecules between cells and play a key role in tumor progression. Hypoxic conditions in tumors promote processes such as angiogenesis, metastasis, and drug resistance, primarily through hypoxia-inducible factors (HIF)-1α and HIF-2α. This study investigates exosome production and stemness properties of cancer cells under hypoxic conditions, in primary and metastatic breast and colon carcinoma cell lines. MATERIALS AND METHODS: Primary breast (MCF7) and colon (Colo320), as well as metastatic breast (M4A4) and colon (Colo741) cancer cell lines, were cultured under hypoxic (3% O2) and normoxic conditions. Exosomes were isolated using the miRCURY™ Exosome Isolation Kit. The distribution of CD9, CD63, CD133, and HIF-1α was analyzed by immunohistochemical staining, and total miRNA was quantified by NanoDrop. RESULTS: Under hypoxia, CD63 expression increased in primary cell lines (MCF7 and Colo320) compared to metastatic lines (M4A4 and Colo741). CD133 immunoreactivity was strong in all cells under hypoxia, while HIF-1α levels remained similar across all conditions. Total miRNA levels in Colo320 and Colo741 were unchanged under hypoxia but increased in MCF7 and decreased in M4A4 under hypoxia. CONCLUSION: Hypoxia significantly enhances exosome secretion and may increase the stemness properties of primary breast and colon cancer cells. Exosomes in the tumor microenvironment could contribute to the malignancy and metastatic potential of aggressive tumors.