Effects of hypoxia on adiponectin in tongue squamous cell carcinoma / 中国肿瘤临床

ABSTRACT

Objective: Adiponectin (APN) is an endogenous cytokine that mediates the development and progression of various tumors through its receptors (AdipoRs). The present study aimed to detect the expression and distribution of APN and its receptors (AdipoR1 and AdipoR2) in tongue squamous cell carcinoma (TSCC). Moreover, we explored whether the locoregional expression of APN was reg-ulated by HIF-1α in the hypoxic microenvironment. Methods: The expression and distribution of APN and its receptors in TSCC tissues were analyzed by immunohistochemical. Lentiviral expression vector for HIF-1α shRNA was constructed and stably transfected in TSCC cells to knock down HIF-1α expression. The mRNA and protein expression levels of APN and its receptors were detected using RT-PCR and Western blot, respectively, after hypoxic treatment. Results: The locoregional expression of APN and AdipoR1, but not AdipoR2, was upregulated at the early stages of T1, T2, and/or N0 stage, respectively, in tumor tissues compared to that in control paracancer-ous tissues (P<0.05 or P<0.01). The expression of APN and AdipoR1, but not AdipoR2, in TSCC cells was up-regulated on hypoxic treat-ment. Moreover, the expression of APN and AdipoR1 was down-regulated after shRNA knockdown of HIF-1α under hypoxia. Conclu-sions The APN-AdipoR1 signaling pathway was activated and regulated by HIF-1α in the hypoxic environment of TSCC tissues.