Dong Jihua

Growth-inhibiting and apoptosis-inducing effects of Tanshinone II A on human gastric carcinoma cells.

To explore the effects of Tanshinone II A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inhibiting effect of Tanshinone II A on MKN-45 cells. The effect of Tanshinone II A on the cell cycle and apoptosis of MKN-45 cells were examined by propidium iodide (PI) staining and flow cytometry. Semi-quantitative RT-PCR was used to further verify the expression of p53 and bcl-2 gene after exposure to Tanshinone A in MKN-45 cells. The results showed that Tanshinone A significantly inhibited the growth and proliferation of MKN-45 cells in a dose-and time-dependent manner (P<0.05). Tanshinone A arrested MKN-45 cells in G2/M phase which led to an obvious accumulation of G2/M phase cells while decreased number of G0/G1 phase cells. This resulted in apoptosis of MKN-45 cells and the apoptosis rate was as high as 43.91% after treatment with 2.0 μg/mL Tanshinone II A for 96 h. It was also found that Tanshinone II A up-regulated expression of p53 gene and down-regulated expression of bcl-2 gene. The cytostatic and antiproliferative effect of Tanshinone II A makes it a promising anticancer agent for the treatment of gastric carcinoma.SummaryTo explore the effects of Tanshinone II A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inhibiting effect of Tanshinone II A on MKN-45 cells. The effect of Tanshinone II A on the cell cycle and apoptosis of MKN-45 cells were examined by propidium iodide (PI) staining and flow cytometry. Semi-quantitative RT-PCR was used to further verify the expression of p53 and bcl-2 gene after exposure to Tanshinone A in MKN-45 cells. The results showed that Tanshinone A significantly inhibited the growth and proliferation of MKN-45 cells in a dose-and time-dependent manner (P<0.05). Tanshinone A arrested MKN-45 cells in G2/M phase which led to an obvious accumulation of G2/M phase cells while decreased number of G0/G1 phase cells. This resulted in apoptosis of MKN-45 cells and the apoptosis rate was as high as 43.91% after treatment with 2.0 μg/mL Tanshinone II A for 96 h. It was also found that Tanshinone II A up-regulated expression of p53 gene and down-regulated expression of bcl-2 gene. The cytostatic and antiproliferative effect of Tanshinone II A makes it a promising anticancer agent for the treatment of gastric carcinoma.

Expression and significance of Oct4 in bladder cancer

SummaryIn order to detect the expression of Oct4 in bladder cancer tissue and cell line BIU-87, immunohistochemistry was used in 49 bladder cancer biopsy samples and immunofluorescence and reverse transcription-PCR were performed on bladder cancer cell line BIU-87. Forty of 49 bladder cancer samples showed the expression of Oct4 in about 0.6% cancer cells. The positive rate and density of Oct4 expression had no obvious relationship with the grade, recurrence or metastasis of bladder cancer (P>0.05). A few Oct4 positive cells were found in bladder cancer cell line BIU-87, which was also confirmed by RT-PCR. This study indicated the existence of few Oct4 positive cells in bladder cancer, which may be the bladder cancer stem cells. This study may provide the foundation for isolation and identification of bladder cancer stem cells.In order to detect the expression of Oct4 in bladder cancer tissue and cell line BIU-87, immunohistochemistry was used in 49 bladder cancer biopsy samples and immunofluorescence and reverse transcription-PCR were performed on bladder cancer cell line BIU-87. Forty of 49 bladder cancer samples showed the expression of Oct4 in about 0.6% cancer cells. The positive rate and density of Oct4 expression had no obvious relationship with the grade, recurrence or metastasis of bladder cancer (P>0.05). A few Oct4 positive cells were found in bladder cancer cell line BIU-87, which was also confirmed by RT-PCR. This study indicated the existence of few Oct4 positive cells in bladder cancer, which may be the bladder cancer stem cells. This study may provide the foundation for isolation and identification of bladder cancer stem cells.

Preparation of curcumin prodrugs and theirin vitro anti-tumor activities

SummaryThe curcumin prodrugs, which could be selectively activated in tumor cells, were prepared to establish a basis for the targeted chemotherapy for cancer. On the basis of the molecular structure of curcumin, the N-maleoyl-L-valine-curcumin (NVC), N-maleoyl- glycine-curcumin (NGC) were chemically synthesized and identified by IR and NMR spectroscopy. After treatment with these two prodrugs for 6–24 h, the rates of growth inhibition on human bladder cancer EJ cells and renal tubular epithelial (HKC) cells were detected by MTT colorimetry. Our results showed that after the treatment with 20 μmol/L–40 μmol/L NVC and NGC for 6–24 h, the growth inhibitory effects on EJ cells were 6.71%–65.13% (P<0.05), 10.96%–73.01% (P<0.05), respectively, in both dose- and time-dependent manners. When compared with the curcumin of same concentrations, the growth inhibitory effects of these two prodrugs on HKC cells were significantly decreased (P<0.01). It is concluded that activation of curcumin prodrugs via hydrolysis functions of cellular esterase could inhibit the growth activities of tumor cells, and reduce the side effects on normal diploid cells. This provided a novel strategy for further exploration of tumor-targeted chemotherapeutic drugs.

Expression of cytokines IL-2, IL-10 and TNF-α in mice with herpes simplex viral encephalitis

SummaryThe expression of the cytokines IL-2, IL-10, TNF-α and their roles in mice with herpes simplex viral encephalitis (HSE) were studied. By using semiquantitative reverse transcription polymerase chain reaction (RT-PCR), the expressions of IL-2, IL-10, and TNF-α mRNA in control group, HSE group and acyclovir (ACV)-treated group were detected and the pathological changes of brain were observed. It was found that after HSV1 infection, the cerebral lesions of haemorrhage and necrosis in mice were observed under the microscopy, and the levels of IL-2, IL-10 and TNF-α were increased remarkably. After treatment with ACV after HSV1 infection, the cerebral lesions in mice were improved, the level of IL-2 maintained stable, IL-10 was increased consistently, and TNF-α was decreased significantly as compared with those in HSE group. In acute HSE, many cytokines are upregulated, including IL-2, IL-10 and TNF-α to eliminate virus and TH1 type response is dominant. In convalescence, there is a shift in the cytokine expression profile from TH1 profile to TH2 profile and the shift can inhibit the overexpression of immune response in animals. ACV has remarkable effects in the treatment of HSE.

Antiviral Effect of Interferon-Induced Guanylate Binding Protein-1 against Coxsackie Virus and Hepatitis B Virus B3 in Vitro

Guanylate binding protein-1(GBP-1) is an interferon-induced protein. To observe its antiviral effect against Hepatitis B virus (HBV) and Coxsackie virus B3 (CVB3), we constructed an eukaryotic expression vector of human GBP-1(hGBP-1). Full-length encoding sequence of hGBP-1 was amplified by long chain RT-PCR and inserted into a pCR2.1 vector, then subcloned into a pCDNA3.1(−) vector. Recombinant hGBP-1 plasmids and pHBV1.3 carrying 1.3-fold genome of HBV were contransfected into HepG2 cells, and inhibition effect of hGBP-1 against HBV replication was observed. Hela cells transfected with recombinant hGBP-1 plasmids were challenged with CVB3, and viral yield in cultures were detected. The results indicated that recombinant eukaryotic expression plasmid of hGBP-1 was constructed successfully and the hGBP-1 gene carried in this plasmid could be efficiently expressed in HepG2 cells and Hela cells. hGBP-1 inhibit CVB3 but not HBV replication in vitro. These results demonstrate that hGBP-1 mediates an antiviral effect against CVB3 but not HBV and perhaps plays an important role in the interferon-mediated antiviral response against CVB3.

Expression of IL-1β and TNF-α in MCMV myocarditis and its role

SummaryIn order to study the expression of IL-1β and TNF-α in the myocardium of MCMV myocarditis and their role in the myocardial damages, 60 BALB/C mice of 4 weeks were randomly divided into two groups: 36 were injected intraperitoneally with MCMV and 24 served as control group. Immunohistochemistry was used to detect IL-1β and TNF-α expression in the myocardium, and myocardial lesions were observed histopathologically. Histopathological study on the myocardium from infected mice revealed focal or diffuse lesions characterized by inflammatory cells and degeneration or necrosis of myocytes. The myocardial lesion score showed the degree of inflammatory cell infiltration was slight in MCMV myocarditis. The positive staining signals for IL-1β and TNF-α proteins which mainly located in the infiltrating inflammatory cells and degenerative or necrotic myocytes were markedly detectable whereas there were no positive findings in the myocardium of control mice. IL-1β and TNF-α was expressed in the myocardium of viral myocarditis murine model induced by MCMV. IL-1β and TNF-α may play an important role in the pathogenesis of viral myocarditis,

Vascular endothelial growth factor165-regulated nasopharyngeal carcinoma cell lines invasion and migration involve expression and activation of matrix metalloproteinase-2

The effect of vascular endothelial growth factor (VEGF) overexpression on matrix metalloproteinase-2 (MMP-2) in nasopharyngeal carcinoma (NPC) cells in vitro and the possible mechanism involved were investigated, and the correlation between the expression of VEGF and MMP-2 in NPC evaluated. The NPC cells were transfected with PAd-trackVEGF165 plasmid. The expression levels of VEGF and MMP-2 mRNA and protein in NPC cells were detected by semi-quantitative RT-PCR and Western blot respectively. It was found that the expression of VEGF and MMP-2 mRNA and protein was significantly increased in NPC cells after transfection of VEGF165. It was concluded that the expression of VEGF was correlated to the in vitro invasion of NPC cells, and the induction of MMP-2 by VEGF was a key process of NPC cell invasion.

Experimental Study on AT1-receptor-peptide-induced Myocardial Immune Damage in Rat

SummaryIn order to investigate the immunological damage in rat immunized with ATI-receptor peptide. 18 male Wistar rats were divided into two groups: immunized-group (n=12), each rat was immunized with 150 μg AT1-receptor petide coupled to bovine serum albumin, together with Freund’s adjuvant. Control group (n=6), sham-immunized, “immunized liquid” was same as immunized-group except ATI-receptor peptide. Systolic blood pressure (SBP) was measured by using the tail-cuff technique, antibody against ATI-receptor peptide detected by using ELISA method, and left ventricular myocardium and renal cortex sections were observed under light and electron microscopy. There was no significant difference in SBP and light microscopic observation of the tissue sections between the immunized-group and control group. The O.D. value of anti-ATI-receptor peptide antiserum was significantly higher in the immunized-group than in the rats before immunization and control group (P<0.01). Positive rate in the immunized-group was 100%, while 0% in the control group. Ultramicroscopic morphology showed potential myocardial injury, including: increase in number of mitochondria, swelling of many mitochondria with reduction in number or absence of their cristae and cristolysis, disorder of the cardiac myofibrils, and myofibrillar disruption and myocytolysis. And lysosomes were increased in renal tubular epithelia. The ATI-receptor peptide could induce to generate the antibody against ATI-receptor peptide and lead to myocardial and renal damage in rats.

Cloning of human Uroplakin II gene from Chinese transitional cell carcinoma of bladder and construction of its eukaryotic expression vector

SummaryTo clone Uroplakin II gene from Chinese transitional cell carcinoma (TCC) of bladder and construct its eukaryotic expression vector, the molecular cloning method was used to extract total RNA from a GIII/T3N0M0 tissue sample of the bladder TCC patients. The primers were designed by Primer 5.0, software. Full length cDNA of Uroplakin II gene was amplified by reverse transcription polymerase chain reaction (RT-PCR), assayed by nucleic acid sequencing and then inserted betweenXba I andHindIII restrictive sites of eukaryotic expression vector pcDNA3.0. The recombinant was assayed by restricted enzyme digestion. Under the induction of Lipofectamine 2000, the recombinant was transfected into Uroplakin II negative bladder cancer cell line EJ. Cellular expression levels of Uroplakin II were detected by RT-PCR. The nucleic acid sequencing results indicated that Chinese Uroplakin II cDNA (555 bp) was successfully cloned. The BLAST analysis demonstrated that the cloned sequence is 100% homologous with sequences reported overseas. The GenBank accession number AY455312 was also registered. The results of restricted enzyme digestion indicated that eukaryotic vector pcDNA-UP II for Uroplakin II, was successfully constructed. After being transferred with pcDNA-UP II for 72 h, cellular Uroplakin II mRNA levels were significantly improved (P<0.01). It is concluded that human Uroplakin II gene was successfully cloned from Chinese TCC tissues, which provided a basis for further exploration of the roles of Uroplakin II gene in TCC biological behaviors and potential strategies for targeted biological therapy of TCC.

INHIBITION OF ACTIVATED K-RAS GENE BY SIRNA EXPRESSION CASSETTES IN HUMAN PANCREATIC CARCINOMA CELL LINE MIAPACA-2

Objective: To construct the small interfering RNA(siRNA) expression cassettes (SECs) targeting activated K-ras gene sequence and investigate the effects of SECs on K-ras gene in human pancreatic cancer cell line MIAPaCa-2. Methods: Three different sites of SECs were constructed by PCR. The K1/siRNA, K2/siRNA and K3/siRNA were located at the site 194, 491 and 327, respectively. They were transfected into MiaPaCa-2 cells by liposome to inhibit the expression of activated K-ras. In the interfering groups of site 194, 491, we observed the cytopathic effect of confluent MiaPaCa-2 cells after they were incubated for 48 hours, and detected the apoptosis in cells by FACS, then we tested the alternation of K-ras gene in confluent MiaPaCa-2 cells by RT-PCR, immunofluorescence and western blot, respectively. Results: Introductions of the K1/siRNA and K2/siRNA against K-ras into MiaPaCa-2 cells led to cytopathic effect, slower proliferation and increased apoptosis, while the appearances of control MiaPaCa-2 cells remained well. The number of apoptotic cells increased compared with control cells. RT-PCR, immunofluorescence and western blot showed the effects of inhibited expression of activated K-ras gene by RNA interference in the K1/siRNA and K2/siRNA groups. We also found that the introduction of K3/siRNA had no effect on MiaPaCa-2 cells. Conclusion: K1/siRNA and K2/siRNA can inhibit the expression of activated K-ras and decrease the growth of MiaPaCa-2 cells, while K3/siRNA has no such effect, demonstrating that the suppression of tumor growth by siRNA is sequence-specific. We conclude that K-ras is involved in maintenance of tumor growth of human pancreatic cancer, and SECs against K-ras expression may be a powerful tool to be used therapeutically against human pancreatic cancer.