The Expression And Significance Of IncRNA TUG1and GAS5in Human Colorectal Cancer

Objective: Long chain non coding RNA (lncRNA) is a hot research topicin recent years. Although not coding any proteins, but lncRNAs can regulatethe expression of specific genes through epigenetic regulation. This presentstudy detected the different expression of lncRNA TUG1(taurine upregulatedgene1) and GAS5(growth arrest permanently5) in colorectal cancer andmatched normal tissues. Smooth muscle22alpha (SM22α) protein is a kind ofimportant cytoskeleton-associated protein. Its expression is down-regulated ina variety of malignant tumors. This subject detected the expression of SM22αat mRNA level and protein level in colorectal cancer tissues and normaltissues, and discussed its significances.Methods: We collected colorectal cancer and normal tissues (10cmfrom tumor tissue) from31patients with colorectal cancer. We tested therelative expression of TUG1, GAS5and SM22genes by real-time quantitativeRT-PCR method, respectively.Results:1. The expression of TUG1and GAS5was increased in cancer tissues.The real-time quantitative RT-PCR analysis showed that theTUG1expression levels in cancer tissues of83.87%cases (26/31) was higherthan that in normal tissues. Similarly, the GAS5expression levels in cancertissues in82.14%cases (25/31) was higher than that in normal tissues. Theresults from the paired-samples t test, the expression of both TUG1and GAS5was up-regulated in cancer tissues, compared with normal tissues (P<0.01).2. The correlation between TUG1and GAS5expression and theclinicopathologic features in colorectal cancerAccording to the real-time quantitative RT-PCR results, we analyzed thecorrelation between the expression of TUG1and GAS5and cancer differentiation degree, lymph node invasion, invasion depth and cancerlocation by independent-samples t test, respectively. The results showed thatthere was no significant difference between two them (P>0.05).3. The level of SM22α protein reduced in cancer tissues.The immunohistochemical results showed that the SM22α protein levelsin cancer tissues were lower than that in normal tissues in90.32%of the cases(28/31)(P<0.05), but no differences in the mRNA level (P>0.05). Theexpression of SM22α protein had no correlation with cancer differentiationdegree, lymph node invasion, invasion depth and cancer location (colon orrectum), respectively (P>0.05).Conclusions:1The levels of TUG1and GAS5in colorectal cancer tissues are higherthan that in matched normal tissues.2TUG1and GAS5may be involved in development of colorectalcancer..3The expression of SM22α protein in cancer tissue was lower than thatin matched normal tissue.4SM22α degradation may increase in colorectal cancer.