Hypoxia stimulates the cytoplasmic localization of oncogenic long noncoding RNA LINC00152 in colorectal cancer

Recent studies have indicated that long noncoding RNAs (lncRNAs) play a pivotal role in almost all physiological cellular processes, including every stage of cancer development. Given that hypoxia in the tumor microenvironment is involved in the malignant behavior of tumors, such as invasion and metastasis, we investigated the cytoplasmic and nuclear localization of lncRNAs in colorectal cancer cells. A cell culture under hypoxic conditions revealed several lncRNAs, such as LINC00152, whose levels were increased in the cytoplasm of colorectal cancer cells. A database study indicated that LINC00152 shares microRNA-binding sites, such as miR-138 and miR-193, with the hypoxia-inducible factor 1 (HIF1), thus suggesting that LINC00152 could possibly function as a competing endogenous RNA that can augment Hif1 translation in the cytoplasm of hypoxic colorectal cancer cells. Moreover, the data presented in the studies of surgically resected samples showed that patients with colorectal cancer exhibiting high LINC00152 expression were associated with a worsened survival rate; this supports the suggested oncogenic function of LINC00152 in the cytoplasm under hypoxic conditions. The present study demonstrated that lncRNA networks could provide diagnostic tools and novel therapeutic targets against colorectal cancer cells.