Abstract:

Objective   To detect the effect and mechanism of miR Let-7a1/f1 on S-adenosylmethionine decarboxylase(AMD1) expression in prostate cancer LNCaP cells. Methods   The pre-miR Let-7a1/f1 sequence was amplified by RT-PCR using RNA from LNCaP cells as the template, and then it was inserted into the pSilencerTM4.1-CMV neo vector to generate pSilencer-let7a1/f1. After pSilencer-let7a1/f1 was transiently transfected into LNCaP cells, expression of miR Let-7a1/f1 was verified by RT-PCR. The effect of miR Let-7a1/f1 on expression of the AMD1 gene was detected by RT-PCR and Western blot. The luciferase reporter vector of AMD1 3′UTR (pMIR-AMD1) was constructed and co-transfected into LNCaP cells with pSilencer-let7a1/f1. Luciferase reporter assay was used to detect the effect of miR Let-7a1/f1 on AMD1 3′-UTR. Results   The sequences of pSilencer-let7a1/f1 and pMIR-AMD1 proved correct by DNA sequencing technique. After pSilencer-let7a1/f1 was transiently transfected into LNCaP cells, expression of miR Let-7a1/f1 was effectively increased; expression of AMD1 mRNA was invariant and expression of the AMD1 protein was downregulated after increased expression of pSilencer-let7a1/f1 in LNCaP cells. The luciferase activity of pMIR-AMD1 was obviously down-regulated by miR Let-7a1/f1. Conclusion   miR Let-7a1/f1 inhibits the translation of AMD1 miR Let-7a1/f1 by action on the AMD1 3′-UTR site in LNCaP cells, and therefore decreases expression of the AMD1 protein.

Key words: miR Let-7a1/f1；Prostatic  neoplasms；Adenosylmethionine decarboxylase