Linc-POU3F3 promotes cell proliferation in gastric cancer via increasing T-reg distribution.

Long noncoding RNA (lncRNA) have been proved to participate in the oncogenesis or development of gastrointestinal tumors. In this study, we aimed to identify the function of lncRNAs in the differentiation of peripheral blood T cells especially the distribution of regulatory T cells (T-reg) in gastric cancer. The distribution of T-reg was detected by flow cytometry. Peripheral blood T-reg cells were significantly up-regulated in plasma samples of gastric cancer patients. LncRNA microarray detection indicated an aberrant expression profiling of lncRNAs in T-reg cells between gastric cancer patients and controls in which linc-POU3F3 was selected as a potential biomarker with the highest fold change value as well as the most stable expression level in each group. In addition, over-expression of linc-POU3F3 elevated Treg distribution in vitro and promoted tumor cell proliferation in the co-culture system. We further found that linc-POU3F3 could recruit TGF-beta which increased the phosphorylation of SMAD2/3. In conclusion, we found that linc-POU3F3 could promote the distribution of Tregs in peripheral blood T cell which caused an enhanced cell proliferation of gastric cancer cells by recruiting TGF-beta as well as activating TGF-beta signal pathway. This finding may provide a theoretical basis for the further exploration of lncRNAs function in immune cell cells of gastric cancer.