Pyrroline-5-carboxylate reductase 1 (PYCR1) is an enzyme involved in cell metabolism, which has been shown to be up-regulated in cancers. However, the functions of PYCR1 in prostate cancers (PCa) are still largely unknown. In the present study, we found that PYCR1 was highly expressed in prostate cancer tissues and then knocked down PYCR1 in PCa cell lines (DU145, PC-3 and LNCap) via lentivirus-mediated gene delivery and analyzed its biological function. Both qRT-PCR and western blotting indicated that PYCR1 was suppressed efficiently after sh-PYCR1 infection. Further analysis indicated knockdown of PYCR1 significantly inhibited PCa cell growth and colony formation ability. The inhibition effects on growth were likely due to G2/M-phase arrest and enhanced cell apoptosis, as determined by flow cytometer analysis. At last, we verified the expression levels of cell cycle regulatory proteins, including CDK1, CDK2, CDK4 and Cyclin B1 were all downregulated and cell apoptotic-related proteins, including cleaved caspase 3 and cleaved PARP were increased in PCa cells after PYCR1 knockdown. Furthermore, PYCR1 has been shown not to be directly regulated by androgen receptor (AR) levels. These results show the functions of PYCR1 in PCa tumorigenesis for the first time and suggest that PYCR1 might be a good potential therapy approach for treating PCa.
Prostate cancer PYCR1 Cell proliferation Cell cycle Apoptosis AR signaling
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The authors are thankful for the financial support from the National Natural Science Foundation of China (81272247 and 81372751).
Compliance with ethical standards
Conflict of interest
Conflict of interest relevant to this article was not reported.
Informed consent was obtained from all individual participants included in the study.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional of Fuzhou General Hospital Affiliated to Fujian Medical University.
Figure S1. (A) The gene delivery efficiency of shPYCR1(S1) in LNCap cells. Upper panels, bright field; lower panels, GFP fluorescence (green). Scale bar, 10 μm. (B) Western blotting analysis of PYCR1 protein levels in shPYCR1(S1)-infected LNCap cells. (C) The proliferation levels of LNCap cells after shPYCR1(S1) infection analyzed by the MTT assay. Data are expressed as mean ± standard deviation (SD) of three independent experiments. ***p < 0.001. (D) Western blot analysis of PYCR1 and PSA protein levels in Con, AR inhibitor (Bicalutamide) or AR activator (DHT) treated LNCap cells. (TIFF 1329 kb)
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