Influence of the interaction between long noncoding RNAs and hypoxia on tumorigenesis.

The interaction between cancer and its microenvironment is crucial for survival and development of cancerous cells. Tumor microenvironment is usually under hypoxia, which promotes tumor aggressiveness like growth, angiogenesis, and metastasis. How cancer cells respond to hypoxia and the resultant impact on tumorigenesis are not yet fully explored. Long noncoding RNAs (lncRNAs) have been attracting more and more attention since their functions in regulating gene expression at chromatic, transcriptional, and posttranscriptional levels were found. lncRNAs are dysregulated in cancer and act as oncogenes or tumor suppressors. Moreover, emerging evidence has been provided that the expression of lncRNAs changes with the stimulus of hypoxia and they in turn produce a significant influence on the hypoxia-inducible factor (HIF), the most common transcription regulator in response to hypoxia. In this review, we discuss the recent findings of hypoxia-responsive lncRNAs and summarize their interaction with hypoxia to further understand their roles in cancer growth, metabolism, angiogenesis, and metastasis and their potential for cancer diagnosis and treatment.