Taken together, these results suggest that although miR-182 is expressed at higher levels in localized prostate cancer, its levels are lower in aggressive cancers, suggesting a biphasic role for this miRNA that may be exploited for prognostic and/or therapeutic purposes to reduce prostate cancer progression.
In vitro studies revealed that overexpression of miR-182 promoted cell proliferation, colony formation, migration, invasion and inhibited cell apoptosis; in vivo results demonstrated that silencing of miR-182 mediated by inhibitor dramatically reduced prostate cancer xenograft tumor growth.
In this regard, we suggest that miR-182-5p may be a key androgen receptor-regulated factor that contributes to the development and metastasis of Chinese prostate cancers and may be a potential target for the early diagnosis and therapeutic studies of prostate cancer.
RESULTS A total of 162 miRNAs were differentially expressed between normal and prostate cancer samples, including 128 up-regulated and 38 down-regulated ones; hsa-mir-153-2, hsa-mir-92a-1, and hsa-mir-182 (up-regulated); and hsa-mir-29a, hsa-mir-10a, and hsa-mir-221 (down-regulated) were identified as good biomarkers.
Comparing with the other 18 types of cancers listed in The Cancer Genome Atlas Data Portal, we found that the combination of both miRNA-182 and miRNA-200c being up-regulated and miRNA-221 being down-regulated only happens in prostate cancer.
Results show that miR-182 and 187 are promising biomarkers for prostate cancer prognosis to identify patients at risk for progression and for diagnosis to improve the predictive capability of existing biomarkers.
Overexpressed microRNA-182 promotes proliferation and invasion in prostate cancer PC-3 cells by down-regulating N-myc downstream regulated gene 1 (NDRG1).
In conclusion this is the first report documenting that over-expression of miR-182-5p is associated with prostate cancer progression and potentially useful as a prognostic biomarker.