It is known that microRNAs (miRNAs) are a class of small, non-coding RNAs that act as key regulators in various physiological and pathological processes. However, the regulatory mechanisms involving miRNAs in prostate cancer remain largely unknown. Here, we found that miR-103 is down-regulated in prostate cancer and closely associated with tumor proliferation and migration. Our objective was to explore the role of the miR-103 in prostate cancer.

In this study, we measured miR-103 level using real-time polymerase chain reaction in the human prostate cancer cell lines, including PC-3, LNCap, 22Rv1, DU145, and the normal prostate epithelium cell line RWPE-1, a total of 25 pairs of primary prostate cancer tissues and adjacent non-cancerous tissues (NCTs) were measured also. In addition, over-expression of miR-103 in prostate cancer cell lines to determine the role of miR-103 in prostate cancer.

We found that miR-103 is down-regulated in prostate cancer and closely associated with tumor proliferation and migration. In addition, over-expression of miR-103 apparently inhibits prostate cancer cell proliferation and migration in vitro. Gain-of-function in vitro experiments further show that miR-103 mimics significantly inhibited prostate cancer cell proliferation, invasion and increase the cell cycle in G1 phase, while promoted cell apoptosis. Subsequent dual-luciferase reporter assay identified one of the proto-oncogene PDCD10 as direct target of miR-103.

Therefore, our data collectively demonstrate that miR-103 is a proto-oncogene miRNA that can suppress prostate cancer proliferation and migration by down-regulating the oncogene PDCD10, indicating that miR-103 may represent a new potential diagnostic and therapeutic target for prostate cancer treatment. Prostate © 2016 Wiley Periodicals, Inc.