Study On The Relationship Between IGF2-derived Intrinsic MiR-483 And Colorectal Cancer

Objective:In this study, we detected the expression of IGF2 gene in CRC tissue and matched normal tissues, and miR-483-3p, miR-483-5p in CRC tissue, matched normal tissues and serum of patients with CRC and healthy controls. We evaluated the association between IGF2 genes, miR-483-3p and miR-483-5p expression levels in CRC tissues and matched normal tissues, whose relevance to clinic-pathological characteristics was further investigated. Association between miR-483-3p and miR-483-5p expression levels in serum of patients with CRC and healthy controls were evaluated, either. We also evaluated the feasibility of detecting miR-483-3p and miR-483-5p in tissue and serum samples of patients with CRC. We evaluated the possibility of IGF2-derived intrinsic miR-483 in the diagnosis CRC.Methods:Clinical tissue samples were collected from 77 patients with CRC, serum specimens collected from 55 of those CRC patients and 31 healthy controls. The clinical data of CRC patients were collected. After extracted the total RNA, both IGF2 expression levels in CRC tissues, matched normal tissues and miR-483-3p/5p expression level in CRC tissues, matched normal tissues and serum sample of patients with CRC and healthy controls were detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). We compared IGF2 and miR-483-3p/5p expression levels of CRC tissues versus adjacent normal tissues and miR-483-3p/5p expression levels of CRC serum versus normal serum. The relationship between expression levels of IGF2 gene, miR-483-3p and miR-483-5p in CRC tissues were analyzed.Finally, the sensitivity and specificity of diagnosis for colorectal cancer were evaluated by using receiver operating characteristic (ROC) curve and area under the ROC curve (AUC).Results:Study results demonstrated that IGF2 was significantly higher in CRC tissues compared with their adjacent normal tissues (p<0.05). The expression of miR-483-3p and miR-483-5p was significantly higher in CRC tissues compared with their adjacent normal tissues (p<.0001). We also found strong positive correlation between miR-483-3p and miR-483-5p (rs=0.5507, p< 0.0001). Beside, a positive correlation between IGF2 mRNA with miR-483-3p (rc=0.4984, p< 0.0001) and miR-483-5p (rs=0.6659, p< 0.0001) expression was found. Next, we examined the correlation between the expression of miR-483-3p and miR-483-5p with clinical parameters. No significant association was found between them with gender, age, tumor location and the TNM staging of CRC (p>0.05). Patients with CRC had a significantly higher level of serum miR-483-5p (p<0.05), compared with normal controls, but not miR-483-3p. ROC curve analyses revealed that at a cut-off value that maximizes the sum of sensitivity and specificity, tissue miR-483-3p corresponding sensitivities and specificity for patients with CRC were 76.62% and 62.34%, miR-483-5p had a sensitivity and specificity of 51.59% and 84.42% for CRC, Combining the two markers, the test has a sensitivity of 88.68% for CRC, and a specificity of 52.62%. the AUC for miR-483-3p and miR-483-5p were 0.7333(95%CI: 0.6542 ～ 0.8125;p<0.0001) and 0.7136(95%CI:0.6332～0.7940; p<0.0001), respectively. Serum miR-483-5p and miR-483-3p had AUC of 0.712 (95%CI: 0.6020-0.8220; p=0.0012) and 0.6012 (95%CI:0.4694-0.7329; p=0.1219), respectively. At the cut-off value less than 2.945 for miR-483-3P, the sensitivity and the specificity were 41.94%and 83.64%, respectively. At the cut-off value less than 22.15 for miR-483-5P, the sensitivity and the specificity were 80.65% and 60%, respectively.Conclusion:The expression of IGF2 gene, miR-483-3p and miR-483-5p was significantly higher in CRC tissues, compared with matched normal tissues. There are positive coefficients of correlation between miR-483-3p and miR-483-5p, and a positive correlation between IGF2 mRNA with miR-483-3p and miR-483-5pexpression. No significant association was found between the expression of miR-483-3p and miR-483-5p with gender, age, tumor size, location and the TNM staging of tumor. Patients with CRC had a significantly higher serum miR-483-5p level compared with normal controls, but not miR-483-3p. The detection of IGF2-derived intrinsic miR-483-3p and miR-483-5p in CRC tissues and serum might be a potential novel tool for screening colorectal cancer.