Integrated omics profiling identifies hypoxia-regulated genes in HCT116 colon cancer cells.

Hypoxia is associated with poor prognosis in most solid tumors due to its multiple effects on therapy resistance, angiogenesis, apoptotic resistance, and tumor invasion/metastasis. Here we used a comprehensive omics profiling to investigate hypoxia-regulated gene expression in HCT116 colon cancer cells. Quantitative analyses of proteome and secretome were performed in HCT116 cells cultured under hypoxic or normoxic conditions. A total of 5700 proteins were quantified in proteome analysis and 722 proteins were quantified in secretome analysis. Both datasets were combined with the transcriptome and translatome datasets for further analysis. Verification of candidate proteins/genes in this integrated omics analysis was performed using immunoblotting and quantitative real-time RT-PCR analyses. We also performed polysome profiling to assess changes in translational efficiency of hypoxia-induced genes. Notably, several genes were differently regulated at the transcriptional and translational levels in HCT116 cells during hypoxia. Bioinformatics analysis suggested that hypoxia regulates translation of genes involved in extracellular matrix organization, extracellular exosomes, and protein processing in endoplasmic reticulum. Aberrations in these metabolic pathways appear to be correlated with an increased risk of tumor invasion/metastasis.

BIOLOGICAL SIGNIFICANCE: This study integrates transcriptome/translatome and proteome/secretome to analyze gene expression changes in human colon cancer cells under hypoxic conditions. Candidate proteins/genes in this integrated omics analysis were further validated by immunoblotting, quantitative real-time RT-PCR, and polysome profiling. The datasets would be useful to uncover the molecular mechanisms of hypoxia-induced gene regulation in colorectal cancer.