Dynamic expression of apoptosis-related genes during development of laboratory hepatocellular carcinoma and its relation to apoptosis

AIM： To explore the expression of p53, bcl-2, bax, survivin and the cell apoptosis during the development of tree shrew hepatocellular carcinoma （HCC）, the relationship between expression of these genes, its impact on HCC development, and its relation to cell apoptosis. METHODS： Tree shrew HCC was induced with aflatoxin B1 （AFB1）, and regular biopsy of liver tissues was carried out and the biopsy tissues were collected during cancer inducement. Liver biopsy tissue and HCC tissue were collected from 35 pre-cancerous experimental animals at wk 30 and 60 and at the 30^th, 60^th, and 90^th -wk. Liver biopsy tissues were collected from 13 blank control animals at wk 30, 60, and 90. Expression of p53, bcl-2, bax, and survivin at each stage was examined by immunohistochemistry method. Apoptotic cells were detected in situ by the terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL） technique. RESULTS： The apoptosis rate of normal hepatic cells was extremely low, whereas it increased during the formation of HCC. Expression of the apoptosis-related genes p53, bcl-2, bax, and survivin during the formation of HCC presented an increasing tendency. Expression of p53 did not noticeably relate to that of bcl-2, bax, and survivin, whereas expression of bcl-2 and bax was closely related. In HCC, p53 did not present a distinct relation to cell apoptosis, whereas its high level expression was probably related to liver cell proliferation. Survivin negatively correlated apoptosis index, and its overexpression could inhibit cell apoptosis. CONCLUSION： Apoptosis-related genes p53, bcl-2, bax, and survivin are all related to the occurrence of HCC. The anti-apoptosis effect of bcl-2 is influenced by bax, and ratio bcl/bax reflects more correctly the extent of cell apoptosis.

AAV2-PDE6B restores retinal structure and function in the retinal degeneration 10 mouse model of retinitis pigmentosa by promoting phototransduction and inhibiting apoptosis

Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death.However,there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation.Adeno-associated virus(AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa.The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function.To do this,we injected retinal degeneration 10(rd10)mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark-and light-adapted electroretinogram,optical coherence tomography,and immunofluorescence.Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment,and the results from this analysis were verified by real-time polymerase chain reaction and western blotting.AAV2-PDE6B injection significantly upregulated PDE6βexpression,preserved electroretinogram responses,and preserved outer nuclear layer thickness in rd10 mice.Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception,and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice.Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways.Furthermore,the phototransductionrelated proteins Pde6α,Rom1,Rho,Aldh1a1,and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment.Finally,Bax/Bcl-2,p-ERK/ERK,and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment.Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.

EXPRESSION AND REVERSION OF DRUG RESISTANCE-AND APOPTOSIS-RELATED GENES OF A DDP-RESISTANT LUNG ADENOCARCINOMA CELL LINE

Objective: To investigate the co-expression of drug resistance- and apoptosis-related genes of cisplatin (CDDP)-selected lung adenocarcinoma cell line A 549 DDP for compared to the parental cell line A549, and reverse of drug resistance by antisense s-oligodeoxynucleotides (S-ODNs) of differentially expressed genes. Methods: Sense and antisense S-ODN were transferred into A 549 DDP cells by lipofectin. The expression of drug resistance and apoptosis related genes was examined by RT-PCR, immunocytochemistry and flow cytometry, respectively. Apoptostic cells were identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT)-mediated biotin dUTP nick end-labeling(TUNEL). Drug resistance of tumor cells was detected by a cell viability (MTT) assay. Results: The expression of bcl-2 was positive and that of multidrug resistance-associated protein (MRP) at mRNA and protein level was increased in A 549 DDP compared to A549 cells. MDR1, c-myc and topoisomeras II (TOPO II) were similarly co-expressed in two cell lines. Both cell lines were negative for c-erbB-2 expression. In A 549 DDP cells, the expression of bcl-2 and MRP was significantly inhibited by their respective antisense S-ODNs. Antisense S-ODNs could also decrease significantly drug resistance of A 549 DDP cells to CDDP by promoting cell apoptosis. Conclusion: Both intrinsic and acquired drug resistance were involved in co-expression of multiple MDR-related genes in lung adenocarcinoma. Cooperation of bcl-2 and MRP genes appeared to play an important action to confer the resistance of A 549 DDP cells to CDDP. Their antisense S-ODNs are responsible for the decrease of drug resistance of this cell line by promoting apoptosis.

^(103)Pd-induced apoptosis of proliferative smooth muscle cells in bile ducts of dogs:significance and effects on related genes

BACKGROUND:With the objective of developing a locally- produced radioactive stent,the present study used in vivo animal experiments to explore apoptosis of proliferative smooth muscle cells resulting from facilitation of the expression of genes caused byγ-radiation in order to prevent bile duct restenosis.We therefore explored the effects and significance ofγ-radiation on the activity of caspase-3,Fas and Bcl-2 genes in apoptosis of proliferative smooth muscle cells in the bile duct walls of dogs. METHODS:Twelve dogs were randomly divided into 2 groups(6 in each group).A postinjury bile duct stenosis model was established and radioactive 103 Pd( 103 palladium) or ordinary bile duct stents were implanted into the bile ducts.HE staining,RT-PCR and immunohistochemistry were used to detect the proliferation and apoptosis of bile duct smooth muscle cells in proliferative endomembrane and the expression of related caspase-3,Bcl-2 and Fas genes. RESULTS:The expression of caspase-3 and Fas genes in the bile duct tissues of dogs with radioactive stents was higher than that of dogs with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the bile ducts.The expression of the Bcl-2 gene in the bile duct tissues of dogs with radioactive stents was lower than that in those with ordinary stents.There was significant apoptosis of proliferative smooth muscle cells in the dogs with low Bcl-2 gene expression. CONCLUSIONS:Radiation increases the activity of caspase-3 and Fas genes and is associated with apoptosis. The radioactive 103 Pd stent may facilitate apoptosis of proliferative smooth muscle cells in the bile ducts of dogs by activating these genes.The Bcl-2 gene expression level is correlated with the occurrence of apoptosis and the radiosusceptibility of cells.

Growth arrest-specific gene 2 suppresses hepatocarcinogenesis by intervention of cell cycle and p53-dependent apoptosis

BACKGROUND Growth arrest-specific gene 2(GAS2)plays a role in modulating in reversible growth arrest cell cycle,apoptosis,and cell survival.GAS2 protein is universally expressed in most normal tissues,particularly in the liver,but is depleted in some tumor tissues.However,the functional mechanisms of GAS2 in hepatocellular carcinoma(HCC)are not fully defined.AIM To investigate the function and mechanism of GAS2 in HCC.METHODS GAS2 expression in clinic liver and HCC specimens was analyzed by real-time PCR and western blotting.Cell proliferation was analyzed by counting,MTS,and colony formation assays.Cell cycle analysis was performed by flow cytometry.Cell apoptosis was investigated by Annexin V apoptosis assay and western blotting.RESULTS GAS2 protein expression was lower in HCC than in normal tissues.Overexpression of GAS2 inhibited the proliferation of HCC cells with wide-type p53,while knockdown of GAS2 promoted the proliferation of hepatocytes(P<0.05).Furthermore,GAS2 overexpression impeded the G1-to-S cell cycle transition and arrested more G1 cells,particularly the elevation of sub G1(P<0.01).Apoptosis induced by GAS2 was dependent on p53,which was increased by etoposide addition.The expression of p53 and apoptosis markers was further enhanced when GAS2 was upregulated,but became diminished upon downregulation of GAS2.In the clinic specimen,GAS2 was downregulated in more than 60%of HCCs.The average fold changes of GAS2 expression in tumor tissues were significantly lower than those in paired non-tumor tissues(P<0.05).CONCLUSION GAS2 plays a vital role in HCC cell proliferation and apoptosis,possibly by regulating the cell cycle and p53-dependent apoptosis pathway.

Transretinoic acid inhibits rats gastric epithelial dysplasia induced by N-methyi-N-nitro-N-nitrosoguanidine:influences on cell apoptosis and expression of its regulatory genes

INTRODUCTIONGastric epithelial dysplasia (GED) hypothetically is a straight-forward concept: dysplastic epithelium replacing the normal gastric epithelium of the stomach [1].In the stomach ,like any other segment of the gut ,it is defined as an unequivocal non-invasive epithelial change[2,3].The observation of gastric dysplasia as a cancerous lesion was recognized over a century ago ,but it is only after the advent of gastroscopy that its clinical significance has been stressed[4-7].

Radiation and androgen withdrawal alter expression of apoptosis pathway genes of prostate cancer cells

Aim: To investigate the altered expression of apoptosis pathway genes of prostate cancer cells treated by radiation and androgen withdrawal and whether the combined treatment may induce additive apoptosis. Methods: Androgen sensitive prostate cancer cell line LNCaP was cultured and treated by radiation, androgen withdrawal and combination of the two. Apoptosis was determined using apoptotic cells staining and mononuclear cell direct cytotox-icity assay. The total RNA were extracted and harvested. cDNA probes were prepared and labeled with biotin-16-dUTP and then hybridized to commercially available cDNA arrays, including apoptosis pathway-specific genes. The expression of important gene was further determined using RT-PCR. Results: Radiation induced additive apoptosis of prostate cancer cells; androgen withdrawal exhibited synergetic action. TNFRSF8 variant 2, DFFA, LTbR, mdm2, Myd88, TNFRSF14 and TNFSF4 mRNA were up regulated by radiation, while Survivin and Bar mRNA were down regulated. Mcl-1, TNFRSF14, MyD88 and TNFSF4 mRNA were up regulated by androgen withdrawal, while Bar, Survivin and TRAIL-R3 mRNA were down regulated. Conclusion: Radiation and androgen withdrawal altered the expression of apoptosis pathway genes of prostate cancer cells in different patterns, which may contribute to the additive apoptotic effect induced by the combined treatment.

THE EXPRESSION OF APOPTOSIS RELATED GENES IN THE PROCESS OF CANCERATION OF ATYPICAL HYPERPLASIA OF MAMMARY DUCT

Objective： To investigate the expression of apoptosis related genes p53 and bcl-2 in atypical hyperplasia of mammary duct and the relationship between the gene expression and oncogenesis of breast. Methods： mRNA of apoptosis related gene p53 and bcl-2 were detected by in situ hybridization in 44 cases of atypical ductal hyperplasia. p53 protein expression was detected by immunohistochemistry. The data were compared with those of 6 cases of benign hyperplasia and 26 cases of breast carcinoma. Results： The expression of p53 mRNA was 66.7% in benign hyperplasia, 40% in atypical ductal hyperplasia （55.6% in mild, 41.7% in medium, 26.1% in severe） and 19.2% in carcinoma （of which 21.4% were intraductal carcinoma and 16.7% were invasive）. The expression of p53 protein was negative in benign hyperplasia, 24% in atypical hyperplasia （mild 11.1%, medium 25%, severe 34.8%）, 38.5% in carcinoma （intraductal carcinoma 35.7%, invasive ductal carcinoma 41.7%）. The expression of bcl-2 was negative in benign hyperplasia, 78.6% in intraductal carcinoma, 83.3% in invasive ductal carcinoma. Conclusion： Loss and mutation of p53 gene and excessive expression bcl-2 mRNA were detected in severe atypical ductal hyperplasia.

EFFECTS OF IFN-a COMBINED WITH IL-6 ON GROWTH AND EXPRESSION OF THE GENES RELATED TO CELL-GROWTH AND APOPTOSIS OF BONE MARROW CELLS FROM PATIENTS WITH CML

Objective:To investigate the effects of interferon-a (IFN-a) and IFN-a combined with interleukin-6 (IL-6) on growth and expression of bcr-abl, bcl-2 and c--myc genes in the mononuclear cells (MNCs) from bone marrow (BM) of patients with chronic myelogenous leukemia (CML). Methods: MNCs were collected from BM of the patients with CML in chronic phase by centrifugation in lymphocyte separation medium and cultured in liquid with IFN-a (200U/ml) or IFN-a (200U/ml) plus IL-6 (100 ng/ml). The growing cells were counted every day. The expression levels of b-actin, bcr-abl, bcl-2 and c-myc genes in the MNCs incubated for 24 h were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and relatively quantitative analysis of the amplified fragments by optical density scanning for the bands on gel. Results: The cell growth was markedly suppressed by IFN-a but the degree of cell-growth inhibition was slightly decreased by IL-6 on the basis of IFN-a effect. The expression of bcr-abl chimeric gene was intensely inhibited by IFN-a or IFN-a plus IL-6. The expression of bcl-2 gene was suppressed by either IFN-a or IFN-a plus IL-6, whereas that of c-myc gene was also inhibited by IFN-a but strongly elevated by IL-6 on the basis of IFN-a action. Conclusions: Both IFN-a and IFN-a plus IL-6 can inhibit the expression of anti-apoptosis gene such as bcr-abl and bcl-2 and regulate the expression of the cs.hn.cn gene related to cell proliferation and differentiation such as c-myc. Either IFN-a or IFN-a combined with IL-6 will serve as a trustful strategy of clinical treatment for CML.

Research Progress on Anti-tumor Mechanism of Clearing Heat-Toxin Intervention of Apoptosis-related Proteins

Apoptosis is a spontaneous programmed cell death process,which is closely related to the occurrence and development of tumors.Inducing apoptosis of tumor cells has become an important way of anti-tumor therapy.Studies have found that clearing heat-toxin Chinese medicine has a significant effect on inducing apoptosis,which may be the key mechanism of anti-tumor of Chinese medicine.By reviewing the theoretical origin of anti-tumor TCM of clearing heat-toxin Chinese herbs and the pharmacological research progress of intervening apoptosis-related proteins to promote apoptosis of tumor cells,this paper provides a basis for TCM to induce apoptosis of tumor cells to prevent and treat malignant tumors.

Analysis of in vivo patterns of caspase 3 gene expression in primary hepatocellular carcinoma and its relationship to p21^(WAF1) expression and hepatic apoptosis

AIM To detect the expression of caspase 3gene in primary human hepatocellular carcinoma（HCC）and investigate its relationship to p21WAF1gene expression and HCC apoptosis.METHODS In situ hybridization was employedto determine caspase 3 and p21WAF1expression inHCC.In situ end-labeling was used to detecthepatocytic apoptosis in HCC.RESULTS Twenty-one of 39（53.8%）cases ofHCC were found to express caspase 3transcripts,while 45.2% of HCC failed toexpress caspase 3.Non-cancerous adjacent livertissues showed more positive caspase 3（87.5%,7/8）as compared with HCC（P【0.05）.The expression of caspase 3 is correlated withHCC differentiation,72.2%（13/18）ofmoderately to highly differentiated HCC showedcaspase 3 transcripts positive,while only 38.1%of poorly differentiated HCC harbored caspase 3transcripts（P【0.05）.No relationship wasfound between caspase 3 expression and tumorsize or grade or metastasis,although 52.5%（5/8）of HCC with metastasis were caspase 3positive and a little higher than that with nometastasis（51.6%,P】0.05）.Expression of caspase 3 alone did not affect the apoptosisindex（AI）of HCC.The AI was 7.12%o in caspase3-positive tumors（n=21）,while in caspase 3-negative cases（n=18）6.59%0（P】0.05）.Expression of caspase 3 clearly segregated withp21WAF1positive tumors as compared withp21WAF1-negative cases（16 of 23,69.6% versus5 of 16,31.3%）with statistical significance（P=0.017）.In the cases with positive caspase 3and negative p21WAF1,the Al was found slightlyhigher,but with no statistical significance,thanthat with expression of p21WAF1and caspase 3（7.21‰ vs 6.98‰,P】0.05）.CONCLUSION Loss of caspase 3 expressionmay contribute to HCC carcinogenesis,althoughthe expression of caspase 3 does not correlatewell with cell apoptosis in HCC.p21WAF1may bemerely one of the inhibitors which can reducecaspase 3 mediated cell apoptosis in HCCs.

Apoptosis,proliferation and p53 gene expression of H.pylori associated gastric epithelial lesions

AIM: To study the relationship between Helicobacter pylori (H. pylori) and gastric carcinoma and its possible pathogenesis by H. pylori. METHODS: DNEL technique and immunohistochemical technique were used to study the state of apoptosis, proliferation and p53 gene expression. A total of 100 gastric mucosal biopsy specimens, including 20 normal mucosa, 30 H. pylori-negative and 30 H. pylori-positive gastric precancerous lesions along with 20 gastric carcinomas were studied. RESULTS: There were several apoptotic cells in the superficial epithelium and a few proliferative cells within the neck of gastric glands, and no p53 protein expression in normal mucosa. In gastric carcinoma, there were few apoptotic cells, while there were a large number of proliferative cells, and expression of p53 protein significantly was increased. In the phase of metaplasia, the apoptotic index (AI, 4.36%+/-1.95%), proliferative index (PI, 19.11%+/-6.79%) and positivity of p53 expression (46.7%) in H. pylori-positive group were higher than those in normal mucosa (P【0.01). AI in H. pylori-positive group was higher than that in H. pylori-negative group (3.81%+/-1.76%), PI in H. pylori-positive group was higher than that in H. pylori-negative group (12.25%+/-5.63%, P【0.01). In the phase of dysplasia, AI (2.31%+/-1.10%) in H. pylori-positive group was lower (3.05%+/-1.29%) than that in H. pylori-negative group, but PI (33.89%+/-11.65%) was significantly higher (22.09+/-8018%, P【0.01). In phases of metaplasia, dysplasia and gastric cancer in the H. pylori-positive group, AIs had an evidently graduall decreasing trend (P【0.01), while PIs had an evidently gradual increasing trend (P【0.05 or P【0.01), and there was also a trend of gradual increase in the expression of p53 gene. CONCLUSION: In the course of the formation of gastric carcinoma, proliferation of gastric mucosa can be greatly increased by H. pylori, and H. pylori can induce apoptosis in the phase of metaplasia, but in the phase of dysplasia H. pylori can inhibit cellular apoptosis. And H. pylori infection can strengthen the expression of mutated p53 gene.

Correlation between expression of gastrin, somatostatin and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma

AIM: To explore the correlation between expression of somatostatin (SS), gastrin (GAS) and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma.METHODS: Sixty-two large intestine cancer tissue samples were randomly and retrospectively selected from patients with large intestine carcinoma. Immunohistochemical staining for bcl-2, bax, GAS, SS was performed according to the standard streptavidin-biotin-peroxidase (S-P) method.According to the semi-quantitative integral evaluation, SS and GAS were divided into three groups as follows. Scores1-3 were defined as the low expression group, 4-8 as the intermediate expression group, 9-16 as the high expression group. Bax and bcl-2 protein expressions in different GAS and SS expression groups of large intestine carcinoma were assessed.RESULTS: The positive expression rate of bax had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 9.246; P＜0.05,x2GAS = 6.981). The positive expression rate of bax in SS high (80.0%, 8/10) and intermediate (76.5%, 13/17)expression groups was higher than that in low expression group (40.0%, 14/35) (P＜0.05, x2high vs low = 5.242; P＜0.05,x2middle vs low = 6.097). The positive expression rate of bax in GAS high expression group (27.3%, 3/8) was lower than that in low expression group (69.4%, 25/36) (P＜0.05,x2 = 4.594). However, bax expression in GAS intermediate expression group (46.7%, 7/15) was lower than that in low expression group, but not statistically significant. The positive expression rate of bcl-2 had a prominent difference between SS and GAS high, intermediate and low expression groups (P＜0.05, x2ss = 7.178; P＜0.05, x2GAS = 13.831). The positive expression rate of bcl-2 in GAS high (90.9%, 10/11)and intermediate (86.7%, 13/15) expression groups was higher than that in low expression group (44.4%, 16/36)(P＜0.05,x2high vs low = 5.600; P＜0.05, x2 middle vs low = 7.695).However, the positive expression rate of bcl-2 in SS high (40.0%, 4/10) and intermediate (47.1%, 8/9) expression groups was lower than that in low expression group (77.1%, 27/35)(P＜0.05, x2 high vs low = 4.710; P＜0.05, x2 middle vs low = 4.706).There was a significant positive correlation between the integral ratio of GAS to SS and the integral of bcl-2 (P＜0.01,r=0.340). However, there was a negative correlation between the integral ratio of GAS to the SS and bax the integral of (P＜0.05, r = -0.299).CONCLUSION: The regulation and control of gastrin,somatostatin in cell apoptosis of large intestine carcinoma may be directly related to the abnormal expression of bcl-2, bax.

Knockdown of survivin gene expression by RNAi induces apoptosis in human hepatocellular carcinoma cell line SMMC-7721

AIM: To investigate the survivin gene expression in human hepatocellular carcinoma cell line SMMC-7721 and the effects of survivin gene RNA interference (RNAi) on cell apoptosis and biological behaviors of SMMC-7721 cells. METHODS: Eukaryotic expression vector of survivin gene RNAi and recombinant plasmid pSuppressorNeo-survivin (pSuNeo-SW), were constructed by ligating into the vector, pSupperssorNeo (pSuNeo) digested with restriction enzymes Xba I and Sail and the designed double-chain RNAi primers. A cell model of SMMC-7721 after treatment with RNAi was prepared by transfecting SMMC-7721 cells with the lipofectin transfection method. Strept-avidin-biotin-complex (SABC) immunohistochemical staining and RT-PCR were used to detect survivin gene expressions in SMMC-7721 cells. Flow cytometry was used for the cell cycle analysis. Transmission electron microscopy was performed to determine whether RNAi induced cell apoptosis, and the method of measuring the cell growth curve was utilized to study the growth of SMMC-7721 cells before and after treatment with RNAi. RESULTS: The eukaryotic expression vector of survivin gene RNAi and pSuNeo-SW, were constructed successfully. The expression level of survivin gene in SMMC-7721 cells was observed. After the treatment of RNAi, the expression of survivin gene in SMMC-7721 cells was almost absent, apoptosis index was increased by 15.6%, and the number of cells was decreased in G2/M phase and the cell growth was inhibited. CONCLUSION: RNAi can exert a knockdown of survivin gene expression in SMMC-7721 cells, and induce apoptosis and inhibit the growth of carcinoma cells.

miR-29a up-regulation in AR42J cells contributes to apoptosis via targeting TNFRSF1A gene

AIM: To investigate the expression of mi R-29 a in rat acute pancreatitis and its functional role in AR42 J cell apoptosis.METHODS: Twelve SD rats were divided into a control group and an acute edematous pancreatitis(AEP) group randomly. AEP was induced by intraperitoneal injection of L-arginine(150 mg/kg) in the AEP group and equal volume of 0.9% Na Cl was injected in the control group. The apoptosis of acinar cells in pancreatic tissue was determined by TUNEL assay. mi RNA chip assay was performed to examine the expression of mi RNAs in two groups. Besides, to further explore the role of mi R-29 a in apoptosis in vitro, recombinant rat TNF-α(50 ng/m L) was administered to treat the rat pancreatic acinar cell line AR42 J for inducing AR42 J cell apoptosis. Quantitative real-time PCR(q RT-PCR) was adopted to measure mi R-29 a expression. Then, mi RNA mimic, mi RNA antisense oligonucleotide(AMO) and control vector were used to transfect AR42 J cells. The expression of mi R-29 a was confirmed by q RT-PCR andthe apoptosis rate of AR42 J cells was detected by flow cytometry analysis. Western blot was used to detect the expression of activated caspase3. Moreover, we used bioinformatics software and luciferase assay to test whether TNFRSF1 A was the target gene of mi R-29 a. After transfection, q RT-PCR and Western blot was used to detect the expression of TNFRSF1 A in AR42 J cells after transfection.RESULTS: The expression of mi R-29 a was much higher in the AEP group compared with the control group as displayed by the mi RNA chip assay. After inducing apoptosis of AR42 J cells in vitro, the expression of mi R-29 a was significantly increased by 1.49 ± 0.04 times in comparison with the control group. As revealed by q RT-PCR assay, the expression of mi R-29 a was 2.68 ± 0.56 times higher in the mi R-29 a mimic group relative to the control vector group, accompanied with an obviously increased acinar cell apoptosis rate(42.83 ± 1.25 vs 24.97 ± 0.15, P < 0.05). Moreover, the expression of mi R-29 a in the mi RNA AMO group was 0.46 ± 0.05 times lower than the control vector group, and the cell apoptosis rate was much lower accordingly(17.27 ± 1.36 vs 24.97 ± 0.15, P < 0.05). The results of bioinformatics software and luciferase assay showed that TNFRSF1 A might be a target gene of mi R-29 a. TNFRSF1 A expression was up-regulated in the mi R-29 a mimic group, while the mi R-29 a AMO group showed the reverse trend.CONCLUSION: mi R-29 a might promote the apoptosis of AR42 J cells via up-regulating the expression of its target gene TNFRSF1 A.

Effect of TSLC1 Gene on Proliferation, Invasion and Apoptosis of Human Hepatocellular Carcinoma Cell Line HepG2

The recombinant plasmid pCI-TSLC1 carrying TSLC1 gene was stably transfected into human hepatocellular carcinoma cell line HepG2. Cell proliferation was analyzed by MTT assay. The ability of migration was determined by transwell and FACSort flow cytometry was used to detect the cell cycle distribution and apoptosis. Western blotting revealed that H4 expressed higher amounts of TSLC1 protein than H15 and H0 did. The growth of TSLCl-transfected cells was significantly suppressed in vitro, and the ability of migration was reduced as well. The re-expression of TSLC1 could induce cell apoptosis. It was concluded that TSLC1 strongly inhibited the growth and ability of migration of HepG2 cell line in vitro and also induced apoptosis, suggesting that TSLC 1 could reduce the tumorigenicity of human hepatocellular carcinoma cell line HepG2 in vitro, which provided a basis for further exploring the roles of TSLC1 in hepatocellular cellular carcinoma.

Protein Expression of BLM Gene and Its Apoptosis Sensitivity in Hematopoietic Tumor Cell Strains

Patients with Bloom syndrome （BS） show an immunodeficiency, an enhanced sister chromatid exchanges （SCEs）, a strong genetic instability and an increased predisposition to all. In order to investigate the differential expression of BLM protein in hematopoietic tumor cell strains and study the effects of BLM gene on ultraviolet （UV）- or hydroxyurea （HU）-induced apoptosis, Western blot was used to detect the expression of BLM protein in normal human bone marrow mononuclear cells and 4 kinds of hematopoietic tumor cell strains. The 4 kinds of hematopoietic tumor cells were exposed to UV light with a germicidal UV lamp or treated with 2 mmol/L hydroxyurea and the apoptotic rate was detected by using AnnexinV-FITC. The results showed that these tumor cells expressed BLM protein higher than the normal human bone marrow mononuclear cells （P〈0.01）. In the 4 hematopoietic tumor cells, BLM protein was all specially cleaved in response to UV- or HU-induced apoptosis. The increase of BLM protein expression may play an important role in the development of these tumors, and BLM proteolysis is likely to be a general feature of the apoptotic response.

Targeted IL-24 gene therapy inhibits cancer recurrence after liver tumor resection by inducing tumor cell apoptosis in nude mice

BACKGROUND: Interleukin-24 (IL-24) is a novel candidate tumor suppressor that induces tumor cell apoptosis experimentally in a variety of human malignant cells including liver cancer cells. The present study was conducted to investigate the potential effect of recombinant adeno-associated virus (rAAV)-mediated IL-24 gene therapy on tumor recurrence and metastasis by inducing tumor cell apoptosis in a hepatocellular carcinoma (HCC) model in nude mice. METHODS: We established a recurrent and metastatic HCC model in nude mice and constructed an rAAV vector carrying alpha-fetoprotein (AFP) promoter for expressing the IL-24 gene (rAVV/AFP/IL-24). The vector was administered by regional injection (liver incisal margin). AFP was detected by radiation immunoassay. Histological evaluation of tumor recurrence and metastasis was performed for the liver and lung. The effect of tumor cell apoptosis was confirmed by TUNEL analysis. RESULTS: IL-24 gene therapy prevented tumor recurrence and metastasis, as evidenced by marked decreases in the number of metastatic tumor nodules and tumor volume in the liver and lung. At the same time, serum AFP concentration decreased markedly in the IL-24 group compared with the control or rAAV groups (P<0.05). IL-24 gene therapy inhibited tumor recurrence and metastasis as evidenced by the induction of tumor cell apoptosis. CONCLUSION: The results demonstrated that targeted IL-24 gene therapy was effective in the prevention of postoperative recurrence and metastasis in an HCC nude mice model by induction of tumor cells apoptosis with potential minimum tumor burden.

Possible mechanism for hepatitis B virus X gene to induce apoptosis of hepatocytes

AIM： To investigate the possible mechanism for HBV X gene to induce apoptosis of hepatocyte HL-7702 cells.METHODS： HBV X gene eukaryon expression vector pcDNA3-X was established and transfected into HL-7702 cells by lipid-mediated transfection, including transient and stable transfection. Positive clones were screened by incubating in the selective medium with 600 μg/mL G418 and named HL-7702/HBV-encoded X protein （HBx） cells. The expressions of Fas/FasL, Bax/Bcl-2, and c-myc mRNA were measured by semi-quantitative RT-PCR in HL-7702/HBx and control group, respectively.RESULTS： RT-PCR analysis confirmed that HBV X gene was transfected into HL-7702 cells successfully. By semiquantitative RT-PCR analysis, Bax and c-myc mRNA levels in HL-7702/HBx cells of transient transfection were significantly higher than those in control, FasL and c-myc mRNA levels in HL-7702/HBx cells of stable transfection were significantly higher than those in control, whereas the Bcl-2 mRNA levels in HL-7702/HBx cells of transient and stable transfection were significantly lower than thosein control.CONCLUSION： HBV X gene may promote the apoptosis of hepatocytes by regulating the expressions of Fas/FasL, Bax/Bcl-2, and c-myc gene in a dose-dependent manner.

Melanoma differentiation-associated gene-7, MDA-7/IL-24, selectively induces growth suppression, apoptosis in human hepatocellular carcinoma cell line HepG2 by replication-incompetent adenovirus vector

AIM： To investigate the effect of replication-incompetent adenovirus vector expressing MDA-7/IL-24 on tumor growth and apoptosis in human hepatocellular carcinoma （HCC） cell line HepG2 and normal liver cell line L02. METHODS： We constructed the recombinant replication-incornpetent Ad.rnda-7 virus vector and infected it into the human HCC cell line HepG2 and normal liver cell line L02. RT-PCR was performed to detect the rnRNA expressing in cells, by ELISA was used to detect MDA-7/IL-24 protein expression in the culture supernatant. The effect of apoptosis induced by Ad.rnda-7 was confirmed by Hoechst staining and flow cytometry assay with Annexin-V and PI staining. MTT assay was used to determine growth inhibition of HepG2 cells, and cell-cycle and hypodiploidy analyses were performed by flow cytometry. RESULTS： Recombinant replication-defective virus expressing MDA-7/IL-24 was constructed successfully. RTPCR showed that the Ad.rnda-7 could mediate the expression of the exogenous gene MDA-7/IL-24 into HepG2 and L02. The concentration of MDA-7/IL-24 protein in supernatant was 130 pg/mL and 110 pg/mL in Ad.rnda-7-infected L02 and HepG2 ceils, respectively. Ad.mda-7 infection obviously induced apoptosis （from 2.604±0.72% to 33.64±13.2%, P=0.00012） and growth suppression in HepG2 （inhibition ratio IR=68%） and an increase in the percentage of specific cancer cell types at the G2/M phase of the cell cycle （from 6.44% to 32.29%, P〈 0.01）, but not in L02 cells.CONCLUSION： These results confirm selectively induction of apoptosis and growth suppression by the mda-7/ IL-24 gene with replication-incompetent adenovirus vector in human hepatocellular carcinoma cell line HepG2.