The HIF-1/PKM2 Feedback Loop in Relation to EGFR Mutational Status in Lung Adenocarcinoma

ObjectiveGene mutations in tumor cells can lead to several unique metabolic phenotypes, which are crucial for the proliferation of cancer cells. EGFR mutation (EGFR-mt) is the main oncogenic driving mutation in lung adenocarcinoma (LUAD). HIF-1 alpha and PKM2 are two key metabolic regulatory proteins that can form a feedback loop and promote cancer growth by promoting glycolysis. Here, the linkage between EGFR mutational status and HIF-1 alpha/PKM2 feedback loop in LUAD were evaluated.MethodsRetrospective study were performed on LUAD patients (n = 89) undergoing first-time therapeutic surgical resection. EGFR mutation was analyzed by real-time PCR. Immunohistochemistry was used to measure the expressions of HIF-1 alpha and PKM2.ResultsWe found that the protein expressions of HIF-1 alpha and PKM2 were significantly higher in LUAD than normal lung tissues. In adenocarcinomas, the two protein expressions were both correlated with worse pTNM stage. Moreover, the correlation between the proteins of HIF-1 alpha/PKM2 feedback loop and the EGFR mutational status were also analyzed. We found that EGFR-mt tumors showed higher HIF-1 alpha and PKM2 proteins compared to tumors with EGFR wild-type. Meanwhile, HIF-1 alpha expression was significantly correlated with higher pTNM stage, and PKM2 showed a similar trend, only in EGFR-mutated tumors. The expression of HIF-1 alpha was positively correlated with PKM2 in LUAD, furthermore, this correlation was mainly in patients with EGFR-mt.ConclusionDifferent expression and clinical features of HIF-1 alpha/PKM2 feedback loop was existed between LUAD and normal lung tissues, especially in EGFR mutational tumors, supporting the relationship between EGFR mutation and the key related proteins of aerobic glycolysis (HIF-1 alpha and PKM2) in lung adenocarcinomas.