Integrated analyses of microRNA-29 family and the related combination biomarkers demonstrate their widespread influence on risk, recurrence, metastasis and survival outcome in colorectal cancer.
miR-29a-5p was screened in a CAC mouse model by high-throughput microarray analysis and investigated in human colorectal cancer tissue samples and colon cell lines by quantitative reverse transcription polymerase chain reaction (Q-RTPCR).
Apart from their role in regular metabolism, abnormal profiles of miRNA expression accompany cancer transformation, including colorectal cancer (CRC) metastasis. microRNAs may play a role in each phase of CRC metastasis including angiogenesis, invasion, intravasation, circulation, extravasation and metastatic colonization. microRNA levels may serve as a predictive CRC marker, which was confirmed by the serum level of miR-29a targeting KLF4, a marker of cell stemness, and the plasma level of miR-221 down-regulating c-Kit, Stat5A and ETS1, which are signal transducers and transcription factor, respectively.
Our data indicated that the expression levels of miR-29a (p< 0.001), miR-223 (p< 0.001) and miR-224 (p< 0.001) are significantly lower in feces from CRC patients than these from normal volunteers, whereas their miR-145 levels are not significantly different (p= 0.59).
In summary, LIFR-AS1 serves as a competitive endogenous RNA (ceRNA) for miR-29a to inhibit its expression and up-regulate downstream target TNFAIP3 expression, finally modulating the resistance of CRC to PDT.