Abstract:

Objective To evaluate the expression levels of serum exosomes miR⁃15b，miR⁃16，miR⁃21 and miR⁃31 in patients with colorectal cancer，and the diagnostic value of single or combined panel for colorectal cancer. Methods A total of 123 patients with colorectal cancer and 117 patients with colorectal adenoma admitted to our hospital from March 2018 to May 2022 were selected as the research objects，and 150 healthy controls were included as the control group. Serum exosomes were extracted and identified，and miR⁃15b，miR⁃16，miR⁃21 and miR ⁃31 in serum exosomes were further extracted and measured by qRT ⁃ PCR. The expression levels of the four miRNAs in each group were compared. The receiver operating characteristic（ROC）curve was drawn to evaluate the diagnostic value of single and combined panel of four miRNAs for colorectal cancer. Results The serum levels of miR ⁃15b，miR ⁃16，miR ⁃21 and miR ⁃31 in colorectal cancer group were higher than those in healthy control group，and the levels of miR⁃15b，miR⁃21 and miR⁃31 were higher than those in colorectal adenoma group（P < 0.05）. The serum levels of miR⁃15b，miR⁃21 and miR⁃31 in stage Ⅲ⁃Ⅳ patients with lymph node invasion and low differentiation were higher than those in stage Ⅰ⁃Ⅱ patients without lymph node invasion and moderate to high differentiation，respectively. The levels of miR ⁃15b，miR ⁃21 and miR ⁃31 were positively correlated with clinical TNM stage and lymph node infiltration，and negatively correlated with the degree of differentiation. Among the four miRNAs，miR ⁃15b was the best index to distinguish rectal cancer from normal subjects，and the sensitivity and specificity were 81.33% and 91.80%，respectively（P < 0.05）. Besides，the combined panel of miR⁃15b，miR⁃21 and miR⁃31 can better distinguish between healthy control group and colorectal cancer. The sensitivity and specificity were 95.06% and 94.44%，respectively（P < 0.05）. Conclusion miR⁃15b，miR⁃16，miR⁃21 and miR⁃31 were abnormally expressed in the peripheral blood serum of patients with colorectal cancer，and the levels of miR⁃15b， miR⁃21 and miR⁃31 were closely related to the onset and progression of colorectal cancer. Moreover，the combined panel model of miR⁃15b，miR⁃21 and miR⁃31 has the potential as a new diagnostic model for colorectal cancer.

Key words:

serum exosomal miRNA, colorectal cancer, miRNA panel, diagnostic value