ABSTRACT
Objective Protein arginine methyltransferase 5 (PRMT5),a member of the histone arginine methylation transferase family,is involved in a wide range of biological regulation through ei-ther epigenetic or posttranslational methylation modifications. The pur-pose of the present study was to investigate the effects of PRMT5 on cell proliferation of ovarian cancer cell HO8910. Methods Cell lines HO8910 with PRMT5 overexpression were obtained by transi-ent transfection,which were divided into three groups in the experiment: blank control group (wild-type cell line HO8910),negative control group (HO8910 cells were transfected with pCMV-myc plasmid),and experimental group (HO8910 cells were transfected with pCMV-myc-PRMT5 plasmid). Western blot was used to detect the expression of myc protein,and qRT-PCR was used to detect the ex-pression of PRMT5 mRNA. Cell lines HO8910 with inducible stable knockdown of PRMT5 were established by shRNA interference method,which were divided into four groups: pLKO control group (infected by empty vector lentivirus),pLKO+Dox (100ng/mL) group,shPRMT5 group (infected by PRMT5shRNA lentivirus) and shPRMT5+Dox (100 ng/mL) group. Western blot and qRT-PCR were used to detect the expression of PRMT5 protein and mRNA levels. Dox-induced PRMT5 knockdown was detected by increasing Dox concentration,which includes four groups,Dox 0ng/mL group,Dox 1ng/mL group,Dox 10ng/mL group,Dox 100ng/mL group,and each group was treated for 48 hours. Western blot and qRT-PCR were used to detect the PRMT5 protein and mRNA expression. Colony formation assay,EdU assay,and CCK-8 assay were used to test cells proliferation. The experiment was conducted in two large groups each with two subgroups: PRMT5 knockdown group (Dox-group,Dox+ group),PRMT5 overexpression group (pCMV-myc group,pCMV-myc-PRMT5 group). Western blot was used to detect the effects of PRMT5 expression on proliferation-related proteins. The experiment was conducted in two large groups,PRMT5 knockdown group with four subgroups : Dox 0ng/mL group,Dox 1ng/mL group,Dox 10ng/mL group and Dox 100ng/mL group,and PRMT5 overexpression group with two subgroups (pCMV-myc group and pCMV-myc-PRMT5 group). Results Western blot results showed that the expression of myc was detected in the experimental group in which HO8910 cells were transfected with pCMV-myc-PRMT5,and the expression of PRMT5 mRNA was significantly higher in the experimental group than those in the blank control group and the negative control group (P<0.001) . Western blot and qRT-PCR showed that PRMT5 protein (0.32±0.25) and mRNA expression levels in shPRMT5+Dox group were significantly lower than those of shPRMT5 group (0.89±0.18) (P<0.05). Western blot and qRT-PCR confirmed that PRMT5 protein (0.21±0.24) and mRNA expres-sion in Dox 10ng/mL group and Dox 100ng/mL group (0.08±0.15) were significantly downregulated compared to Dox 0ng/mL group (1.11±0.15) (P<0.05). Colony formation experiments,EdU experiments,and CCK-8 experiments confirmed that the proliferative ca-pacity of cells in Dox+group was lower than that of Dox-group in PRMT5 knockdown group(P<0.05); while in PRMT5 overexpression group,the proliferative capacity of pCMV-myc-PRMT5 group was significantly higher than that of the pCMV-myc group (P<0.05). Western blot results showed that the protein expression of Cyclin D1 was significantly lower in Dox 100 ng/mL group (0.17±0.06) than that in Dox 0 ng/mL group (1.18±0.18) (P<0.05) and the expression of P21 was significantly increased in PRMT5 knockdown group (P<0.05). In the PRMT5 overexpression group,the protein expression of Cyclin D1 in pCMV-myc-PRMT5 group (3.48± 0.22) was higher than that in pCMV-myc group (0.88±0.15) (P<0.05),while the protein expression of P21 (0.08±0.17) were significantly lower than that of pCMV-myc group (4.12±0.10) (P<0.05). Conclusion PRMT5 plays an important role in the proliferation of ovarian cancer cells. Down-regulation of PRMT5 can inhibit cell proliferation and up-regulation of PRMT5 can pro-mote cell proliferation.
ABSTRACT
<p><b>BACKGROUND AND OBJECTIVE</b>Nitric oxide (NO) is involved in many physiologic and pathologic processes. As an important biologic mediator, NO has been the focus of cancer study for its function in tumorigenesis, tumor progression, and death. This study investigated the effect of NO donor sodium nitroprusside (SNP) on the growth and proliferation of gastric cancer cell line AGS.</p><p><b>METHODS</b>The growth inhibition of AGS cells was analyzed using MTT assay. The cell cycle was measured using flow cytometry. The changes of mRNA expression of proliferating cell nuclear antigen (PCNA) and caspase-3 were examined using reverse transcriptase polymerase chain reaction (RT-PCR), and the protein expressions of PCNA and caspase-3 were analyzed using Western blot.</p><p><b>RESULTS</b>Dose-dependent SNP inhibited cell growth and proliferation. When the AGS cells were treated with SNP at 100, 500, 1000, 1500, and 2000 mumol/L for 24 h, the growth inhibition rates were (2.02 +/- 2.96)%, (10.82 +/- 2.21)%, (18.95 +/- 3.35)%, (26.88 +/- 2.54)%, and (42.57 +/- 1.27)%, respectively (P < 0.05). SNP altered the cell cycle in AGS cells. Compared with the control group, treatment with SNP at 100, 500, 1000, 1500, and 2000 mumol/L for 24 h reduced the number of cells in the S phase by 2.29%, 7.8%, 11.34%, 20.49%, and 23.6%, respectively, and enhanced the number of cells in the G1/G0 phases by 3.33%, 9.3%, 13.46%, 21.37%, and 24.73%, respectively (P < 0.05). With the increasing concentration and action time of SNP, the expressions of PCNA mRNA and protein decreased. The expression of caspase-3 mRNA remained unchanged, but procaspase-3 was activated.</p><p><b>CONCLUSION</b>NO not only inhibits cell growth and proliferation, but also induces apoptosis in gastric cancer cells, and such effects of NO showed significant dose-dependent activity.</p>