Objective Lysine-specific demethylase 1 (LSD1) is a flavin adenine dinucleotide-dependent oxidase, which participates in many biological processes , such as cell proliferation and differentiation and gene activation and repression .The aim of this study was to investigate LSD1 acetylation by histone deacetylase inhib -itor trichostatin A ( TSA) and its effect on TSA-induced apoptosis of ovarian cancer cells . Methods LSD1 shRNA was synthesized and implanted into the pLKO-Tet-On lentiviral vector , which was transfected into HO8910 and SKOV3 ovarian cancer cell lines , and then the transfected cells were screened with 1.5μg/mL puromycin for one week until stable clones were established .The cells were treated for 48 hours with methanol (2 mg/mL, control), TSA (200 nmol/L), TCP (100μmol/L), or TSA+TCP.And in the experiment of RNA interfering the LSD1 expression, the cells were also treated for 48 hours with methanol (2 mg/mL, control), TSA (200 nmol/L), Dox (100 ng/mL), or TSA +Dox.The levels of LSD1 acetylation and its substrate histone H3 lysine 4 dimethylation (H3K4me2) were de-tected by immunoprecipitation (IP) and Western blot.The apoptosis of the cells was determined by Annexin Ⅴ/PI staining and flow cytometry, the transcription levels of the Bax and p21 genes detected by real-time quantitative PCR, and the H3K4me2levels in the promoter regions of Bax and p21 measured by chromatin immunoprecipitation ( ChIP ) .Results In comparison with the methanol control, the TSA group showed significantly increased levels of LSD 1 acetylation in the HO8910(1.00±0.29 vs 5.83±0.46, P<0.01) and SKOV3 cells ( 1.00±0.24 vs 5.07±0.35, P<0.01) as well as that of H3K4me2 ( P<0.01);the total apoptosis rates of HO 8910 and SKOV3 cells were remarkably increased in the TSA, TCP, and TSA+TCP groups (P<0.05), even more significantly in the TSA+TCP than in the TSA and TCP groups ( P<0.05) .The mRNA expressions of Bax and p21 in the HO8910 cells were markedly upregulated in the TSA, Dox, and TSA+Dox groups (P<0.05), even more significantly in the latter than in the former two groups (P<0.05).The TSA group exhibited a higher level of H 3K4me2 than the methanol control in the promoters of Bax(2 .92±0.26 vs 0.68±0.19, P<0.01) and p21 (3.07±0.29 vs 0.93±0.17, P<0.01). Conclusion TSA induces the LSD1 acetylation, while suppression of LSD1 expres-sion and activity may enhance the antitumor activity of TSA .

BACKGROUND AND OBJECTIVENitric 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.

METHODSThe 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.

RESULTSDose-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.

CONCLUSIONNO 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.

Apoptosis ; drug effects ; Caspase 3 ; genetics ; metabolism ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Enzyme Activation ; drug effects ; Gene Expression Regulation, Neoplastic ; Humans ; Nitric Oxide Donors ; pharmacology ; Nitroprusside ; pharmacology ; Proliferating Cell Nuclear Antigen ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Stomach Neoplasms ; metabolism ; pathology

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.

OBJECTIVE: To construct a bi-cistronic co-expression plasmid for mouse interleukin-12 and to observe its expression in vitro or in vivo.METHODS: The full-length cDNA encoding p35 and p40 was cloned into eukaryotic cells expression vector pcDNA 3.1 respectively. Subsequently,the p35 expression unit was inserted into pcDNA 3.1/p40 to produce the bi-cistronic co-expression plasmid in which the p35 and p40 genes were controlled by their own CMV.The plasmid was expressed in vitro and in vivo. RESULTS: The mIL-12 in the supernatant was detected by ELISA after the pCmIL-12 was transfected into COS-7 cells. The activity of NK cells could be augmented by the supernatant in vitro and also by by intradermal delivery of pCmIL-12 in vivo. CONCLUSION: The plasmid constructed by us can express biologically active mIL-12 in vitro and in vivo.

OBJECTIVETo analyze the clinical effect of spinal cord decompression and lavage therapy on chronic cervical spinal cord injury and explore the possible mechanism.

METHODSFifty-seven patients with chronic cervical spinal cord injury treated in our hospital from January, 2008 to January, 2015 were enrolled, including 17 with multilevel cervical disc herniation, 25 with long segmental ossification of the posterior longitudinal ligament, 13 with hypertrophy or calcification of neck ligamentum flavum, and 2 with old cervical fractures. Open-door spinal canal laminoplasty via a posterior approach and decompression in simple extramedullary decompression was performed in 31 cases (group A), and open-door spinal cord incision decompression via a posterior approach, saline irrigation, and spinal canal laminoplasty in intramedullary decompression was performed in 26 cases (group B). The pre-operative cerebrospinal fluid in group B patients was collected to examine the inflammatory factors. All the patients were followed up and evaluated for pre- and postoperative JOA scores to calculate the improvement rate with regular examinations by X-ray, CT or MRI.

RESULTSImaging examinations 2 weeks after the operation showed obvious relief of the primary lesion in both groups, and the improvement of high signals was better in group B than in group A. The mean improvement rate at 12 months after the operation was 52.33% in group A and 61.52% in group B (P<0.05), and the mean JOA score was significantly higher in group B than in group A (14.80∓1.51 vs 13.58∓0.56; P<0.05). Cerebrospinal fluid leakage occurred in 3 cases, epidural hematoma in 2 cases, internal fixation loosening in 1 case in group A; portal shaft fracture and internal fixation loosening occurred in 1 case in group B. Postoperative recovery time was shorter in group B and entered the platform phase in 3 months. The inflammatory factors IFN-γ, IL-17F, IL-6 and sCD40L were all significantly higher than the normal levels after spinal cord injury, and the increment of IL-6 was the most conspicuous (P<0.05).

CONCLUSIONIntramedullary and extramedullary decompression can achieve better outcomes than extramedullary decompression in patients with chronic cervical cord injury. This may be related not only to relieving adhesions and secondary compression by cutting the dura under the microscope, but also to removal of local inflammatory factors.