Developing microRNA Biomarkers for Prostate Cancer
Short, noncoding regulatory stretches of RNA known as microRNA hold promise as prostate cancer biomarkers.
Worldwide, prostate cancer is the most common malignancy diagnosed in men. Early detection remains a challenge, however, as prostate specific antigen (PSA) tests remain controversial and imprecise, contributing to overtreatment. While prognostic and treatment-outcome-predicting molecular biomarkers are available for other cancer types, similar tools have proven elusive for prostate cancer. Several research teams around the world are now developing biomarker microRNAs (miRNAs)—small bits of non-protein-coding RNA involved in gene regulation and typically containing fewer than 25 nucleotides.1,2 miRNAs are dysregulated in different cancer types, including prostate cancers.
miRNAs can be extracted from tissues, blood, serum, plasma, or urine; their short sequence length renders them less fragile and more persistent in tissues and biofluids than longer nucleic acid sequences, which tend to fragment, noted Olorunseun O. Ogunwobi, MD, PhD, an associate professor at Hunter College of the City University of New York.
Structural stability in tissues and biofluids implies improved reproducibility in testing, Dr Ogunwobi noted. These molecules are promising targets for the development of both biomarkers and drug development.
“Understanding their roles in cancers such as their differential expression in the different stages of cancer may result in the discovery of prognostic biomarkers as well as possible therapeutic targets,” he told Cancer Therapy Advisor.
“The 8q24 human chromosomal region contains the long non-protein coding gene locus, PVT1. The PVT1 gene locus is dysregulated in prostate cancer. The PVT1 gene locus encodes six miRNAs: miR-1204, miR-1205, miR-1206, miR-1207-3p, miR-1207-5p and miR-1208.”
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Dr Ogunwobi's laboratory has been working to understand the role of the PVT1 locus and its miRNAs in prostate cancer. They discovered that miR-1207-3p, in particular, is “significantly underexpressed” in prostate cancer cell lines compared to normal prostate epithelial cells. Its increased expression inhibits prostate tumor cell proliferation and migration, and induced apoptosis, his team found.