{'fraction_non_alphanumeric': 0.022819885900570498, 'fraction_numerical': 0.004889975550122249, 'mean_word_length': 5.362694300518135, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Effects of Hypoxia on Proliferation and Apoptosis of Osteosarcoma Cells

Background: Hypoxia can happen during solid tumor growth including osteosarcoma. This study investigated the relationship of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) on osteosarcoma cell growth and apoptosis under hypoxic conditions. Materials and Methods: Human osteosarcoma cells were cultured under normal or hypoxic conditions. Inhibitors of HIF-1α and VEGF were applied to the cells separately or in combination to block the respective proteins. Cell proliferation and apoptosis were examined by MTT and TUNEL assays, and real-time PCR and ELISA were performed for mRNA and protein expression. Results: There was a dramatic decrease of cell proliferation and an elevation of apoptosis under hypoxia. Blockage of HIF-1α and VEGFR enhanced the cell growth retardation and promoted apoptotic changes. Moreover, blockage of HIF-1α significantly eliminated the expression of VEGF in the cell culture media, and vice versa. Conclusion: HIF-1α and VEGF work closely in regulating osteosarcoma cell growth under hypoxic conditions and blockage of either of them may subsequently influence the presence of the other.