Effect Of Immunomodulating Peptide On Ovarian Cancer SKOV3Cell Apoptosis And Related Gene Expression

Objective To study the effect of immunomodulatory peptide （PGPIPN） on humanovarian cancer skov3cell apoptosis and related gene expression.Method Skov3cells cultured in vitro were cultured with different concentrations ofPGPIPN （10-6¹0-2g/L） for24,48and72h. Inhibitory effect of immunomodulatingpeptide on Skov3proliferation was tested by MTT. The SKOV3cells incubated withPGPIPN were observed by flow cytometric assay （FCM）. Apoptotic bodies of SKOV3cells induced with PGPIPN were observed by Hoechst33258staining. The cDNAmicroarray was used to screen difference expressions of genes relevant to apoptosis.The bax, bcl-x, and caspase-3genes were selected to test their mRNA levels byflurescent quantitative polymerase chain reaction （PCR）. Bax, Bcl-xl and Caspase-3genes were analyzed by Western blot.Results1. PGPIPN could inhibit the proliferation of SKOV3cells and changed the cellcycle, in which PGPIPN at10^-2 and10^-4 g/L after48and72hours significantlydecreased the cell rates in G0/G1phase and increased the cell rates in S phase（P<0.05）.However, PGPIPN didn’t affect human liver LO2cells.2. By Hoechst33258staining,PGPIPN at10^-2 and10^-4 g/L could significantly induce SKOV3cells apoptosis after48and72hours.3. The nuclear chromatin became highly aggregation and appearedhighlighted fluorescent.4. cDNA microarray results showed that compared with thecontrol group, the low dose group have screened1177different genes which contained791up-regulated and386down-regulated genes. The high dose group have screened744different genes which contained486up-regulated and258down-regulatedgenes.5.Compared with the control group, the mRNA levels expression of bax wasincreased with the increase of the concentration PGPIPN （P <0.05）. The mRNA levels expression of bcl-xl was decreased with the increase of the concentration PGPIPN （P<0.01）. The mRNA levels expression of caspase-3was increased with the increase ofthe concentration PGPIPN （P<0.05）.6.Compared with the control group, the proteinexpression of Bax was increased with the increase of the concentration PGPIPN （P<0.05）. The protein expression of Bcl-xl was decreased with the increase of theconcentration PGPIPN （P <0.01）. The protein expression of Caspase-3was increasedwith the increase of the concentration PGPIPN （P<0.05）.Conclusion1.PGPIPN could inhibit SKOV3cells proliferation and induce their apoptosis, but don’t affect normal human cells.2.PGPIPN could induce the cell apoptosis by increasing the expression of bax and decreasing the expression ofbcl-xl, the process of which was partly caspase-dependent.