OBJECTIVETo explore the effect of interfering ADAM10 on proliferation and apoptosis of multiple myeloma MM.1S cells, and its possible mechanism.

METHODSFour pairs of shRNA-coding sequences directed against different sites of ADAM10 mRNA were designed and inserted into lentiviral vector plasimd pLVshRNA-EGFP(2A) Puro for constructing the sh/ADAM10-1, sh/ADAM10-2, sh/ADAM10-3, sh/ADAM10-4 and sh/Con. These plasmids and lentiviral packaging plasmids were co-transfected into the packaging cells 293FT, then the virus particles were collected and the viral titer was assayed after concentration, and these viral particles were transfected to MM.1S cells. The flow cytometry was used to sort GFPcells. Real-time quantitative PCR, and Western blot were used to detect the effect of interfering the ADAM10 gene by lentiviral vector mediated shRNA. The proliferation-inhibition curve was plotted by CCK-8 method, the cell viability and apoptosis were detected by flow cytometry with Annexin V and 7-AAD staining, the transcripts of pro-apoptosis gene BAD, BAK, BIK, anti-apoptotic genes BCL-2, c-Myc and Notch1 target gene Hes-1 were detected by real-time PCR.

RESULTSLentivirus vector was successfully constructed, that could specifically interfere ADAM10 expression. Interfering ADAM10 gene could inhibit the MM.1S cell proliferation and induce apoptosis. After the interferencing ADAM10 gene the mRNA levels of pro-apoptosis gene BAD, BAK and BIK were increased, and the mRNA levels of anti-apoptotic genes BCL-2 and c-Myc were reduced. Q-PCR results showed that the mRNA level of Notch1 were increased, but that of Hes-1 were reduced.

CONCLUSIONDown-regulated ADAM10 expression can significantly inhibit multiple myeloma MM.1S cell proliferation and promote the apotosis. Its mechanism may be related to Notch1 signaling pathways.