CRC screening methods by using colonoscopies and fecal occult blood tests (FOBT) have improved survival rates by early detection. However, there are still problems by removing the precancerous polyps during colonoscopies procedure, although FOBT testing have less invasion procedure but low sensitive and specific.
 
miRNA as a biomarker for CRC 
Therefore, new non-invasion and accurate biomarkers are needed to improve by evaluating for their potential in this area. Over the last decade, miRNA expression has been proven to examinate the association of CRC incidence and prognosis by detecting not only fecal miRNA but also circulating miRNA as a non-invasion early detection biomarker (Schetter AJ, 2012).
 
Biomarkers from stools
Measuring microRNA in stools provide another non-invasion methods to detect CRC. Both of miR-21 and miR106a with high expression in CRC patients (Link A, 2010). Hypermethylation pattern of miR-34b/c in stools may have promise as a screening tool for distinguishing CRC cases from controls.
 
A potential of circulating markers in CRC patients
Circulating microRNAs can be detected in blood serum or plasma. miR-92 may be a useful marker for disease recurrence after surgical removal of the tumor (Ng EK et al. 2009). miR-141 has been shown to be elevated in metastatic CRC which conjugated with carcinoembryonic antigen (CEA) to detect CRC with distance metastases (Cheng H et al.2011).
Human antigen R (HuR) has been reported to enhanced CRC cancer growth by overexpressing in RNA regulation. miR-155-5p regulated HuR expression by mediating AU-rich elements (AREs) at 3’ UTR region and has showed inhibition of cell migration (Amr Al-Haidari et al. 2018).
 
Angiogenesis as a potential biomarker in CRC
A previous study showed targeting angiogenesis in the CRC treatment is also a common strategy and miRNA involved in several angiogenic pathway. They are stable in biological fluids which been a potential biomarker. The circulating plasma levels of miR-20b, miR-29b and miR-155 as predictors of Bevacizumab treatment in CRC patients. (Paola Ulivi et al. 2018).

TOOLS launched a comprehensive list of miRNA assays that covers miRNAs reported in breast cancer studies. The TOOLS miRNA assay system consists of TOOLS miRNA RT Kit, TOOLS miRNA RT-qPCR primer/probe set, and TOOLS Easy 2X probe qPCR mix. All TOOLS miRNA RT-qPCR primer/probe set are pre-designed, well-validated, and QC. Customized design and production of miRNA RT-qPCR primer/probe set is also available. TOOLS miRNA assay allows rapid, sensitive, and specific profiling the expression of microRNA (miRNA) within the simple 2-step RT-qPCR procedure.
To see the full list of TOOLS miRNA assay and related products, please click TOOLS Life Science Reagents - tools-biotech.com‎.

TOOLS provides well-validated RT-qPCR assay set to CRC associated miRNAs.

Product name miRNA ACC Product name miRNA ACC Product name miRNA ACC Product name miRNA ACC hsa-let-7a-5p MIMAT0000062 hsa-miR-150-5p MIMAT0000451 hsa-miR-210-3p MIMAT0000267 hsa-miR-342-3p MIMAT0000753 hsa-let-7d-5p MIMAT0000065 hsa-miR-15b-5p MIMAT0000417 hsa-miR-214-3p MIMAT0000271 hsa-miR-34a-5p MIMAT0000255 hsa-let-7f-5p MIMAT0000067 hsa-miR-17-3p MIMAT0000071 hsa-miR-215-5p MIMAT0000272 hsa-miR-34c-5p MIMAT0000686 hsa-miR-101-3p MIMAT0000099 hsa-miR-17-5p MIMAT0000070 hsa-miR-21-5p MIMAT0000076 hsa-miR-375-3p MIMAT0000728 hsa-miR-103a-3p MIMAT0000101 hsa-miR-181a-5p MIMAT0000256 hsa-miR-218-5p MIMAT0000275 hsa-miR-378a-3p MIMAT0000732 hsa-miR-106a-5p MIMAT0000103 hsa-miR-181b-5p MIMAT0000257 hsa-miR-222-3p MIMAT0000279 hsa-miR-378a-5p MIMAT0000731 hsa-miR-106b-5p MIMAT0000680 hsa-miR-182-5p MIMAT0000259 hsa-miR-223-3p MIMAT0000280 hsa-mir-409-3p MIMAT0001639 hsa-miR-107 MIMAT0000104 hsa-miR-184 MIMAT0000454 hsa-miR-224-5p MIMAT0000281 hsa-miR-421 MIMAT0003339 hsa-miR-10a-5p MIMAT0000253 hsa-miR-185-5p MIMAT0000455 hsa-miR-23a-3p MIMAT0000078 hsa-miR-423-5p MIMAT0004748 hsa-miR-1207-5p MIMAT0005871 hsa-miR-186-5p MIMAT0000456 hsa-miR-24-3p MIMAT0000080 hsa-miR-425-5p MIMAT0003393 hsa-miR-122-5p MIMAT0000421 hsa-miR-18a-5p MIMAT0000072 hsa-miR-25-3p MIMAT0000081 hsa-miR-429 MIMAT0001536 hsa-miR-125a-5p MIMAT0000443 hsa-miR-18b-5p MIMAT0001412 hsa-miR-26a-5p MIMAT0000082 hsa-miR-451a MIMAT0001631 hsa-miR-125b-5p MIMAT0000423 hsa-miR-192-5p MIMAT0000222 hsa-miR-27a-3p MIMAT0000084 hsa-miR-452-5p MIMAT0001635 hsa-miR-126-5p MIMAT0000444 hsa-miR-193a-5p MIMAT0004614 hsa-miR-27b-3p MIMAT0000419 hsa-miR-455-3p MIMAT0004784 hsa-miR-132-3p MIMAT0000426 hsa-miR-193b-3p MIMAT0002819 hsa-miR-29a-3p MIMAT0000086 hsa-miR-455-5p MIMAT0003150 hsa-miR-133a-3p MIMAT0000427 hsa-miR-194-5p MIMAT0000460 hsa-miR-29a-5p MIMAT0004503 hsa-miR-497-5p MIMAT0002820 hsa-miR-133b MIMAT0000770 hsa-miR-195-5p MIMAT0000461 hsa-miR-29b-3p MIMAT0000100 hsa-miR-501-3p MIMAT0004774 hsa-miR-135a-5p MIMAT0000428 hsa-miR-196a-5p MIMAT0000226 hsa-miR-30a-3p MIMAT0000088 hsa-miR-502-3p MIMAT0004775 hsa-miR-135b-5p MIMAT0000758 hsa-miR-196b-5p MIMAT0001080 hsa-miR-30a-5p MIMAT0000087 hsa-miR-506-3p MIMAT0002878 hsa-miR-139-3p MIMAT0004552 hsa-miR-199a-3p MIMAT0000232 hsa-miR-30b-5p MIMAT0000420 hsa-miR-550a-5p MIMAT0004800 hsa-miR-1-3p MIMAT0000416 hsa-miR-199b-5p MIMAT0000263 hsa-miR-30d-5p MIMAT0000245 hsa-miR-574-3p MIMAT0003239 hsa-miR-140-3p MIMAT0004597 hsa-miR-19a-3p MIMAT0000073 hsa-miR-31-5p MIMAT0000089 hsa-miR-576-5p MIMAT0003241 hsa-miR-141-3p MIMAT0000432 hsa-miR-19b-3p MIMAT0000074 hsa-miR-320d MIMAT0006764 hsa-miR-625-3p MIMAT0004808 hsa-miR-142-3p MIMAT0000434 hsa-miR-200a-3p MIMAT0000682 hsa-miR-324-3p MIMAT0000762 hsa-miR-663a MIMAT0003326 hsa-miR-142-5p MIMAT0000433 hsa-miR-200c-3p MIMAT0000617 hsa-miR-32-5p MIMAT0000090 hsa-miR-765 MIMAT0003945 hsa-miR-143-3p MIMAT0000435 hsa-miR-203a-3p MIMAT0000264 hsa-miR-330-3p MIMAT0000751 hsa-miR-92a-3p MIMAT0000092 hsa-miR-144-3p MIMAT0000436 hsa-mir-204-3p MIMAT0022693 hsa-miR-335-5p MIMAT0000765 hsa-miR-92b-3p MIMAT0003218 hsa-miR-145-5p MIMAT0000437 hsa-miR-204-5p MIMAT0000265 hsa-miR-338-3p MIMAT0000763 hsa-miR-933 MIMAT0004976 hsa-miR-146a-5p MIMAT0000449 hsa-miR-205-5p MIMAT0000266 hsa-miR-33a-5p MIMAT0000091 hsa-miR-93-5p MIMAT0000093 hsa-miR-149-5p MIMAT0000450 hsa-miR-20a-5p MIMAT0000075 hsa-miR-340-5p MIMAT0004692 hsa-miR-9-5p MIMAT0000441

References

• Centers for Disease Control and Prevention. https://www.cdc.gov/cancer/colorectal/
• Graham, J. S. and Cassidy, J. (2012). Adjuvant therapy in colon cancer. Expert Rev. Anticancer Ther. 12, 99-109.
• Rousseau B, et al. Stage II and stage III colon cancer: treatment advances and future directions. Cancer J. 2010;16(3):202–209.
• Schetter AJ, Okayama H, Harris CC. The role of microRNAs in colorectal cancer. Cancer J. 2012 May-Jun;18(3):244-52.
• Fecal MicroRNAs as novel biomarkers for colon cancer screening. Link A, Balaguer F, Shen Y, Nagasaka T, Lozano JJ, Boland CR, Goel A Cancer Epidemiol Biomarkers Prev. 2010 Jul; 19(7):1766-74.
• Differential expression of microRNAs in plasma of patients with colorectal cancer: a potential marker for colorectal cancer screening. Ng EK, Chong WW, Jin H, Lam EK, Shin VY, Yu J, Poon TC, Ng SS, Sung JJ Gut. 2009 Oct; 58(10):1375-81.
• Circulating plasma MiR-141 is a novel biomarker for metastatic colon cancer and predicts poor prognosis. Cheng H, Zhang L, Cogdell DE, Zheng H, Schetter AJ, Nykter M, Harris CC, Chen K, Hamilton SR, Zhang W PLoS One. 2011 Mar 17; 6(3):e17745.
• Al-Haidari A, Algaber A, Madhi R, Syk I, Thorlacius H. MiR-155-5p controls colon cancer cell migration via post-transcriptional regulation of Human Antigen R (HuR). Cancer Lett. 2018 May 1;421:145-151.
• Ulivi, P.; Canale, M.; Passardi, A.; Marisi, G.; Valgiusti, M.; Frassineti, G.L.; Calistri, D.; Amadori, D.; Scarpi, E. Circulating Plasma Levels of miR-20b, miR-29b and miR-155 as Predictors of Bevacizumab Efficacy in Patients with Metastatic Colorectal Cancer. Int. J. Mol. Sci. 2018, 19, 307.