Hyperthermia combined with chemotherapy induce tongue squamous cell carcinoma cell apoptosis by down-regulating HIF-1α and CYPJ expression / 中华放射肿瘤学杂志

ABSTRACT

Objective:The investigate the roles and significance of HIF-1α and CYPJ in tongue squamous cell carcinoma cell (TSCC), and further evaluate the regulatory effect of hyperthermia (HT) on HIF-1α and CYPJ in TSCC cells.Methods:Eighty samples of cancer tissues and adjacent normal tissues from TSCC patients were collected. The expression levels of HIF-1α and CYPJ were detected by immunohistochemistry, Western blotting (WB) and fluorescence quantitative PCR, and the relationship between the expression levels of HIF-1α and CYPJ and clinicopathological characteristics was further analyzed. The expression levels of HIF-1α and CYPJ in Cal-27 cells under normoxic and hypoxic conditions for 24 h when combined with HT (42℃), chemotherapy and both were detected by qPCR and WB. Cell migration was detected by cell scratch test and cell apoptosis was measured by flow cytometry.Results:The expression levels of HIF-1α and CYPJ proteins in the tumor tissues of TSCC patients were higher than those in the adjacent normal tissues, which were significantly correlated with tumor size, TNM stage, differentiation degree and lymph node metastasis in TSCC patients (all P<0.05), whereas they were not correlated with gender or age (all P>0.05). The expression levels of HIF-1α and CYPJ in Cal-27 cells were significantly up-regulated in the hypoxic microenvironment (both P<0.05), which were also significantly enhanced by hyperthermia alone (both P<0.05). Compared with hyperthermia or chemotherapy alone, hyperthermia combined with chemotherapy significantly inhibited the expression of HIF-1α and CYPJ, suppressed cell migration and promoted cell apoptosis (all P<0.05). Conclusions:HIF-1α and CYPJ may be potential biomarkers for TSCC tumorigenicity and prognosis. In addition, tumor recurrence after hyperthermia may be due to the role of hyperthermia in triggering HIF-1α expression, which promotes the growth and survival of tumor cells adaptive to hyperthermia treatment by activating the downstream target genes, while hyperthermia combined with chemotherapy may be a promising treatment for TSCC.