Abstract A22: Hypoxia-mediated translational control of hypoxia inducible factor 1 alpha through aldolase A feedback regulation in lung carcinogenesis

Abstract

Abstract Lung cancer cells grow in-situ during low-oxygen situation and usually results in invasion and is frequently recurrent after therapy. However, the oxygen-mediated translation control of the metabolic events in lung cancer remains largely unknown. By using the integrated transcriptomics data and the shRNA library against glycolytic enzymes, here we identified that Aldolase A (ALDOA) up-regulation is highly correlated with migratory/invasive activity of lung cancer cells and poorer clinical outcomes. Significantly, knockdown of Aldolase A inhibited in vitro and in vivo migratory/invasive activity of lung cancer cell line with high ALDOA expression. Complementary, enforced overexpression of exogenous ALDOA promoted migration/invasion. Furthermore, microarray and Ingenuity pathway analyses reveal that ALDOA-driven lung cancer metastasis likely recruits Hypoxia-inducible factor 1 alpha (HIF1α)-associated signaling pathway. There were no significance changes at the mRNA level of HIF1α in ALDOA two-way models. However, HIF1α protein was found stabilized in hypoxic or normoxic condition through ALDOA overexpression to decrease prolyl hydroxylase (PHD) activity for hydroxylation-form of HIF1α to activate downstream genes including CXCR4, MMP9 in lung carcinogenesis. Interesting, HIF1α also was found to bind hypoxia-response element (HRE) domain of ALDOA to activate its transcription and form a positive feedback loop. IHC staining results further demonstrate that Aldolase A and HIF1α expression is positively correlated in clinical lung cancer tissues and the signature of high-level Aldolase A and HIF1α; expression strongly associates with worst survival probability in lung cancer patients. Our results not only unveil molecular mechanism by which Aldolase A promotes lung cancer metastasis via inducing the HIF1α activity but also provide a novel therapeutic strategy to combat malignant lung cancer via targeting ALDOA. Citation Format: Yu-Chan Chang, Michael Hsiao. Hypoxia-mediated translational control of hypoxia inducible factor 1 alpha through aldolase A feedback regulation in lung carcinogenesis. [abstract]. In: Proceedings of the AACR Special Conference on Translational Control of Cancer: A New Frontier in Cancer Biology and Therapy; 2016 Oct 27-30; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2017;77(6 Suppl):Abstract nr A22.