PARP1 rs1136410 Val762Ala contributes to an increased risk of overall cancer in the East Asian population: a meta-analysis.

OBJECTIVES: To investigate the association between poly(ADP-ribose) polymerase 1 (PARP1) rs1136410 Val762Ala and cancer risk in Asian populations, as published findings remain controversial. METHODS: The PubMed and EMBASE databases were searched, and references of identified studies and reviews were screened, to find relevant studies. Meta-analyses were performed to evaluate the association between PARP1 rs1136410 Val762Ala and cancer risk, reported as odds ratio (OR) and 95% confidence interval (CI). RESULTS: A total of 24 studies with 8 926 cases and 15 295 controls were included. Overall, a significant association was found between PARP1 rs1136410 Val762Ala and cancer risk in East Asians (homozygous: OR 1.19, 95% CI 1.06, 1.35; heterozygous: OR 1.10, 95% CI 1.04, 1.17; recessive: OR 1.13, 95% CI 1.02, 1.25; dominant: OR 1.13, 95% CI 1.06, 1.19; and allele comparison: OR 1.09, 95% CI 1.03, 1.15). Stratification analyses by race and cancer type revealed similar results for gastric cancer among the Chinese population. CONCLUSION: The findings suggest that PARP1 rs1136410 Val762Ala may be significantly associated with an increased cancer risk in Asians, particularly the Chinese population.

[Analysis of a pedigree affected with hereditary coagulation factor XII deficiency due to a homozygous 252delAsn deletion of F12 gene].

OBJECTIVE: To analyze the clinical phenotype and genetic basis of a consanguineous pedigree affected with hereditary coagulation factor XII (FXII) deficiency. METHODS: Following extraction of genomic DNA, all exons and flanking regions of F12 gene were subjected to PCR amplification and Sanger sequencing. ClustalX-2.1-win and MutationTaster software was used to analyze the conservation and impact of the variants on protein function. RESULTS: DNA sequencing showed that the proband carried a homozygous g.6753-6755delACA deletion (p.252delAsn) in exon 9 of the F12 gene, for which her father, mother and brother were heterozygous carriers. The same deletion was not found in her sister. CONCLUSION: The homozygous p.252delAsn deletion probably underlies the hereditary FXII deficiency in this pedigree.

Exosomal miR-141-3p regulates osteoblast activity to promote the osteoblastic metastasis of prostate cancer.

Exosomes from cancer cells, which contain microRNA and reach metastasis loci prior to cancer cells, stimulate the formation of a metastatic microenvironment. Previous studies have shown that exosomal miR-141-3p is associated with metastatic prostate cancer (PCa). However, the role and regulatory mechanism of miR-141-3p in the microenvironment of bone metastases require further study. In this study, we performed a series of experiments in vivo and in vitro to determine whether exosomal miR-141-3p from MDA PCa 2b cells regulates osteoblast activity to promote osteoblastic metastasis. We demonstrate that extracts obtained from cell culture supernatants contained exosomes and that miR-141-3p levels were significantly higher in MDA PCa 2b cell exosomes. Via confocal imaging, numerous MDA PCa 2b exosomes were observed to enter osteoblasts, and miR-141-3p was transferred to osteoblasts through MDA PCa 2b exosomes in vitro. Exosomal miR-141-3p from MDA PCa 2b promoted osteoblast activity and increased osteoprotegerin OPG expression. miR-141-3p suppressed the protein levels of the target gene DLC1, indicating its functional significance in activating the p38MAPK pathway. In animal experiments, exosomal miR-141-3p had bone-target specificity and promoted osteoblast activity. Mice injected with miR-141-3p-mimics exosomes developed apparent osteoblastic bone metastasis. Exosomal miR-141-3p from MDA PCa 2b cells promoted osteoblast activity and regulated the microenvironment of bone metastases, which plays an important role in the formation of bone metastases and osteogenesis damage in PCa. Clarifying the specific mechanism of bone metastasis will help generate new possibilities for the treatment of PCa.

A specific aptamer-cell penetrating peptides complex delivered siRNA efficiently and suppressed prostate tumor growth in vivo.

Specific and efficient delivery of siRNA into intended tumor cells remains as a challenge, even though RNAi has been exploited as a new strategy for prostate cancer therapy. This work aims to address both specificity and efficiency of SURVIVIN-siRNA delivery by constructing a therapeutic complex using combinatorial strategies. A fusion protein STD was first expressed to serve as a backbone, consisting of streptavidin, a cell-penetrating peptide called Trans-Activator of Transcription (TAT) and a double-stranded RNA binding domain. A biotinylated Prostate Specific Membrane Antigen (PSMA) specific aptamer A10 and SURVIVIN-siRNA were then linked to STD protein to form the therapeutic complex. This complex could specifically targeted PSMA(+) tumor cells. Compared to lipofectamine and A10-siRNA chimera, it demonstrated higher efficiency in delivering siRNA into target cells by 19.2% and 59.9%, and increased apoptosis by 16.8% and 26.1% respectively. Upon systemic administration, this complex also showed significant efficacy in suppressing tumor growth in athymic mice (p <0.001). We conclude that this therapeutic complex could specifically and efficiently deliver SURVIVIN-siRNA to target cells and suppressed tumor growth in vivo, which indicates its potential to be used as a new strategy in prostate cancer therapy.

Role of soluble programmed death-1 (sPD-1) and sPD-ligand 1 in patients with cystic echinococcosis.

The programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) signaling pathway is a negative regulatory mechanism that inhibits T cell proliferation and cytokine production. Soluble PD-1 (sPD-1) and soluble PD-L1 (sPD-L1), are also involved in regulation of the PD-1/PD-L1 signaling pathway. In the present study, the expression levels of sPD-1 and sPD-L1, as well as those of T helper (Th)1 [including interleukin (IL)-2 and interferon gamma], Th2 (including IL-4, IL-6 and IL-10) and Th17 (including interleukin 17) cell cytokines, were measured in the sera of patients with cystic echinococcosis (CE). Measurements were performed prior to and following after surgery and treatment with cyclic albendazole to investigate the effects of sPD-1 and sPD-L1 in patients with CE. Cytokine expression levels were measured using cytokine bead array and the expression levels of sPD-1 and sPD-L1 were measured using ELISA. In addition, in vitro stimulation was used to detect whether sPD-L1 has a negative regulatory effect on cytokine secretion or homeostasis. The present study observed significantly higher levels of sPD-L1 in patients with CE compared with healthy controls. Significantly elevated levels of Th2 cytokines in the sera of patients with CE were also observed. The results also suggest that there is an imbalanced expression of Th1 and Th2 cells during CE. In addition, it was demonstrated that sPD-1 and sPD-L1 are regulatory factors to the PD-1/PD-L1 signaling pathway, each having opposite effect, suggesting that they regulate the immune response to CE infection by creating a dynamic balance. In conclusion, sPD-L1 may play an important role in maintaining homeostasis in hosts with CE.

Transcriptional and proteomic analyses of two-component response regulators in multidrug-resistant Mycobacterium tuberculosis.

Two-component systems (TCSs) have been reported to exhibit a sensing and responding role under drug stress that induces drug resistance in several bacterial species. However, the relationship between TCSs and multidrug resistance in Mycobacterium tuberculosis has not been comprehensively analysed to date. In this study, 90 M. tuberculosis clinical isolates were analysed using 15-loci mycobacterial interspersed repetitive unit (MIRU)-variable number tandem repeat (VNTR) typing and repetitive extragenic palindromic (rep)-PCR-based DNA fingerprinting. The results showed that all of the isolates were of the Beijing lineage, and strains with a drug-susceptible phenotype had not diverged into similar genotype clusters. Expression analysis of 13 response regulators of TCSs using real-time PCR and tandem mass spectrometry (MS/MS) proteomic analysis demonstrated that four response regulator genes (devR, mtrA, regX3 and Rv3143) were significantly upregulated in multidrug-resistant (MDR) strains compared with the laboratory strain H37Rv as well as drug-susceptible and isoniazid-monoresistant strains (P<0.05). DNA sequencing revealed that the promoter regions of devR, mtrA, regX3 and Rv3143 did not contain any mutations. Moreover, expression of the four genes could be induced by most of the four first-line antitubercular agents. In addition, either deletion or overexpression of devR in Mycobacterium bovis BCG did not alter its sensitivity to the four antitubercular drugs. This suggests that upregulation of devR, which is common in MDR-TB strains, might be induced by drug stress and hypoxic adaptation following the acquisition of multidrug resistance.

[Transcriptional activities of tumor-specific survivin promoter and PSMA promoter and enhancer in human prostate cancer: evaluation and comparison].

OBJECTIVE: To detect and compare the transcriptional activities of prostate-specific membrane antigen (PSMA) promoter and enhancer and survivin promoter in different human prostate cancer cell lines, and to search for some evidence for the targeting gene therapy of human prostate cancer. METHODS: The fragments of the PSMA promoter and enhancer and survivin promoter were amplified by PCR and inserted into pGL3-Basic. The recombinant plasmids were transiently transfected into human prostate cancer cell lines and normal Chang liver cells, and, their transcriptional activities in various cells were determined by measuring the expression of luciferase. RESULTS: The survivin promoter exhibited a higher transcriptional activity than PSMA promoter and enhancer in tumor cell lines, and the S2pro promoter showed the highest activity, reaching one third of that of the CMV promoter. CONCLUSION: The survivin promoter is highly activated in prostate cancer cell lines and may serve as a new tool for the transcriptional targeting gene therapy of prostate cancer.

[Effects of TFDP3 on regulating the autophagy and apoptosis of LNCaP cells].

AIM: To investigate the effect of TFDP3 on prostate cancer cell line LNCaP by transgenic method, and to explore the effect of TFDP3 on regulating the autophay and apoptosis by co-regulation with E2F1. METHODS: LNCaP cells were transfected with pcDNA3.1-TFDP3, pCMV-E2F1-HA or pcDNA3.1 empty vector.The expression of TFDP3, E2F1 and LC3B were detected by real-time PCR after transfection for 24 h. Western blotting was used to monitor the changes in autophagy-associated protein LC3B, Apoptosis of transfected cells were analyzed by flow cytometry. RESULTS: The results showed that activation of TFDP3 upregulates the expression of autophagy genes-microtubule-associated protein-1 light chain-3B (LC3B), and E2F1 antagonizes TFDP3-induced autophagy, and TFDP3 can inhibit E2F1-induced apoptosis. CONCLUSION: TFDP3 upregulates the expression of autophagy gene LC3B and inhibits E2F1-induced apoptosis, and may play an important role in prostate cancer.

Novel immunohistochemical monoclonal antibody against human glucose-regulated protein 78.

Glucose-regulated protein (GRP78), an ER chaperone that belongs to the heat-shock protein (HSP) family, exist in all cells and plays important roles in maintaining cellular homeostasis. GRP78 participates in protein folding, transportation, and degradation. Lack of high affinity antibodies especially monoclonal antibodies (MAbs) suitable for Western blot and immunohistochemical staining has lagged. To gain further insight into its possible functions, we generated a novel MAb specific for hGRP78 in Western blot and immunohistochemistry and localized hGRP78 in some human cancer cell lines and cancer tissues. Immunoreactivity of GRP78 was prominent in Hela, Colo205, and A549 detected by 3F9 in Western blot analysis. 3F9 antibody recognized endogenous GRP78 in human cervical cancer, colonic cancer, esophageal cancer, and lung cancer. Thus, successful production of GRP78 monoclonal antibodies provides a new powerful tool for investigation of GRP78 function.

Evaluation of a new rapid influenza A diagnostic test for detection of pandemic (H1N1) 2009 and seasonal influenza A virus.

BACKGROUND: Rapid influenza A diagnostic tests (RIDTs) play an important role in the clinical setting, especially in the influenza post-pandemic era with three influenza A viruses in circulation. OBJECTIVES: Determine the sensitivity and specificity of a new RIDT (FluA Dot) by comparison with BD Directigen EZ FluA+B and CDC rRT-PCR. STUDY DESIGN: Two sets of experiments were conducted to determine the performance of the new test. (1) Serial dilutions of eight pandemic (H1N1) 2009 (pH1N1) isolates, five seasonal H3N2 isolates, five seasonal H1N1 isolates and three recombinant nucleoproteins were tested by FluA Dot assay, Directigen EZ FluA+B test and CDC real-time RT-PCR. (2) Using CDC rRT-PCR as the gold standard, the clinical sensitivity and specificity of the FluA Dot and Directigen EZ FluA+B were evaluated in nasopharyngeal swab (NPS) specimens of 807 patients presenting with influenza-like illness. RESULTS: The average analytical sensitivity of FluA Dot (0.06 ng/mL for recombinant nucleoproteins and 2.16 ± 0.85 log 10 TCID(50) for viruses) was approximately 10-fold higher than Directigen EZ FluA+B (1-2 ng/mL for recombinant nucleoproteins and 3.54 ± 0.81 log 10 TCID(50) for viruses), and was approximately 10-fold lower than the CDC rRT-PCR (1.09 ± 0.69 log 10 TCID(50) for viruses). Among 807 NPS specimens tested, the sensitivities and specificities of FluA Dot were 91.1% (95%CI: 86.7-94.4%)/99.7% (95%CI: 98.7-99.9%), and the Directigen EZ FluA+B were 71.9% (95%CI: 65.7-77.6%)/99.8%(95%CI: 99.0-99.9%). CONCLUSION: The new test (FluA Dot) exhibit higher sensitivity than Directigen EZ FluA+B both in pH1N1 and seasonal influenza A detection. The promising RIDT can play important roles in influenza diagnosis and therapy.

Inhibition of prostate cancer by suicide gene targeting the FCY1 and HSV-TK genes.

Prostate cancer is one of the most prevalent tumors. The switch of androgen signal dependence makes therapy more complex. Although reports on introduction of a single suicide gene exist, double suicide gene therapy has not been reported yet. In the current study, two suicide genes were constructed in the pIRES plasmid driven by PSMA promoter. 5-FC and GCV combination in vitro led to a higher growth inhibition on prostate cancer compared to a single pro-drug. Retarded xenograft tumor growth was observed in castrated nude mice after double suicide gene activation. Furthermore, decreased metastasis was observed with double suicide gene treatment. These findings suggest that specific double suicide gene strategy could be a potential option for the therapy of prostate cancer.

Knockdown of survivin expression by siRNAs enhances chemosensitivity of prostate cancer cells and attenuates its tumorigenicity.

Survivin, a member of inhibitor of apoptosis family protein, has become an attractive therapeutic target in cancer due to its selective expression in tumor cells and its important roles for tumor cell viability. Here, we show that vector-based small interfering RNAs (siRNAs) silenced survivin expression in prostate cancer cells, resulting in significantly reduced cell proliferation and enhanced apoptosis, and increased the sensitivity of prostate cancer cells (PC-3) to the apoptosis- inducing agent, platinol. Furthermore, PC-3 cells transfected with the siRNA-expressing vector showed lower tumor formation in nude mice xenografts in vivo. These results demonstrated that inhibition of survivin expression by siRNA attenuated the malignant phenotypes of prostate cancer cells, and may provide a novel approach for gene therapy of androgen-independent prostate cancer.

[Immune response induced by Rpf domain from Micrococcus luteus in mice].

AIM: To investigate the immunobiology of Rpf domain from Micrococcus luteus. METHODS: BALB/c mice were immunized with Rpf domain three times at 2-week interval. ELISA was used to detect the title of the anti-Rpf domain antibody titer in the immunized mice sera. The spleen lymphocytes of the immunized mice were separated and the stimulation index (SI) was measured by MTT colorimetry. The levels of secreted IFN-gamma, IL-10 and IL-12 upon specific antigen stimulation was detected by ELISA. The Rpf domain immunized BALB/c mice were intravenously infected with 10(5) CFU MTB H37Rv. The number of CFU in the spleens was determined four weeks after final injection. RESULTS: The titer of the specific antibody in sera of the immunized BALB/c mice was 1:128 000. The SI of Rpf domain immunized group (2.10+/-0.12) was significantly higher than that of saline immunized group (0.90+/-0.21). The lever of IFN-gamma, IL-10 and IL-12 levels in culture supernatant of spleen lymphocytes from the fusion protein immunized mice was (1 126+/-36) ng/L, (368+/-13) ng/L and (289+/-14) ng/L, respectively, which was markedly higher than that of saline immunized group (P<0.01). Compared with normal saline immunized mice (6.64+/-0.13) four weeks after final injection, dramatic reduction in MTB replication was observed in the spleen (5.03+/-0.11) from the BALB/c mice immunized with fusion proteins. CONCLUSION: Rpf domain can be used as a candidate for a new TB vaccine.

[Preparation and characterization of monoclonal antibodies against Micrococcus luteus Rpf domain].

AIM: To express Micrococcus luteus Rpf domain in prokaryotic cells and prepare monoclonal antibodies against Rpf domain. METHODS: The gene encoding Micrococcus luteus Rpf domain was amplified from genome of Micrococcus luteus by polymerase chain reaction(PCR), and inserted into cloning vector pUC-19. After sequenced, Micrococcus luteus Rpf domain gene was subcloned into the expression vector pPro-EXHT and transfected into E.coli DH5alpha. After induced by IPTG, the bacteria controlled by T7 promoter expressed the fused Micrococcus luteus Rpf domain protein with a hexahistidine tail at its N-terminal and the target protein was purified under denaturing conditions. Using this protein as antigen to immunize the BALB/c mice and prepare monoclonal antibodies against Micrococcus luteus Rpf domain. Then specifities and relative affinities of mAbs were identified by ELISA. RESULTS: The fusion protein was purified by metal chelate affinity chromatography under denaturing condition. Three cloned mAbs were prepared from the mice immunized by Rpf domain. All of them could recognize Rpf domain. specifically. CONCLUSION: The prepared mAbs against Rpf domain have strong specificity with high titers, which provides useful tools for further study of the function of Rpf domain in TB prevention.

[Detection of transcriptional activities of tumor-specific survivin promoter in human prostatic carcinoma].

OBJECTIVE: To clone DNA sequence of the survivin promoter and study is transcriptional activities in human prostate cancer cells and normal Chang liver cells. METHODS: The fragment of the survivin promoter was acquired by PCR amplification and inserted into pPRIME vectors to reconstruct a recombinant plasmid named pPRIME-S1pro and pPRIME-S2pro. Then the reconstructed plasmid was transiently transfected into human prostate cancer cells lines LNCaP and normal Chang liver cells. The transcriptional activities of the survivin promoter in various cells was determined by measuring the expression of green fluorescent protein (GFP). RESULTS: The survivin promoter had transcriptional activities in LNCaP cells and the transcriptional activity of the S2pro was much higher that of the S1pro, reaching a level of 39% of the transcriptional activity of the CMV promoter. CONCLUSION: The survivin promoter cloned in the therapy for prostate cancer.

A new Multi-PCR-SSCP assay for simultaneous detection of isoniazid and rifampin resistance in Mycobacterium tuberculosis.

Prompt detection of drug resistance in Mycobacterium tuberculosis is essential for effective control of tuberculosis (TB). We developed a Multi-PCR-SSCP method that detects more than 80% commonly observed isoniazid (INH) and rifampin (RIF) resistance M. tuberculosis in a single assay. The usefulness of the newly developed method was evaluated with 116 clinical isolates of M. tuberculosis. Distinct SSCP patterns were observed for different mutations and the correlation between Multi-PCR-SSCP results and DNA sequencing data was strong. Using the culture-based phenotypic drug susceptibility testing as a reference, the sensitivity of the newly developed Multi-PCR-SSCP assay was determined to be 80% and 81.8% for INH and RIF, respectively. The specificity of the assay was 100% and 92%, for INH and RIF, respectively. Multi-PCR-SSCP provides a rapid and potentially more cost-effective method of detecting multidrug-resistant TB.

[Construction of the eukaryotic expression vector of bioactive fragment of human bactericidal/permeability-increasing protein and its expression in CHO cells].

AIM: To construct the eukaryotic expression vector of the cDNA sequence encoding bioactive N-terminal fragment of human bactericidal/permeability-increasing protein (BPI) and express it in CHO cells. METHODS: Total RNA was extracted from human polymorphonuclear leukocytes (PMN) and subjected to reverse transcription, then the human BPI cDNA gene was amplified by nested PCR. The PCR product was cloned into pUC19 plasmid and confirmed by restriction enzyme digestion and DNA sequencing. Then the specific BPI encoding fragment was subcloned into pcDNA3 plasmid to form pcDNA-BPI(N) eukaryotic expression vector. CHO cells were transfected with the recombinant plasmid and the stable clones were selected by G418. The expression of BPI was identified by immunofluorescent assay. RESULTS: Restriction enzyme digestion and DNA sequence analysis revealed that the sequence encoding signal peptide and bioactive N-terminal fragment of BPI had six nucleotide substitutions, compared with that of the established human BPI sequence. The expression products of the selected CHO positive cell clones were detected by anti-BPI monoclonal antibody. CONCLUSION: The construction of the eukaryotic expression vector of bioactive fragment of human BPI and its successful expression in CHO cells are helpful to further study of the role of BPI.

Immune responses to recombinant Mycobacterium smegmatis expressing fused core protein and preS1 peptide of hepatitis B virus in mice.

Attenuated strains of bacteria have been developed as potential live vectors to express homologous or heterologous antigens of many pathogens for inducing protective immune responses. The non-pathogenic and rapidly growing Mycobacterium smegmatis can be transformed effectively by genes for pathogenic antigens, and has been used as a valuable vector for the development of live vaccines. However, little is known on whether M. smegmatis could be transformed with the genes for HBV antigens and could express those genes, and whether vaccination with recombinant M. smegmatis could induce humoral and cellular immune responses in vivo. Both the core protein and preS1 peptide of the hepatitis B virus (HBV) are immunogenic and can induce cellular and humoral immune responses. This made them ideal platform for the development of new vaccines. In the present study, both recombinant M. smegmatis and DNA vaccines were generated to express the CS1 antigen, a fusion protein that comprises truncated core protein (amino acids 1-155) and preS1 peptide (amino acids 1-55) of HBV. Following vaccination of BALB/c mice with the live recombinant M. smegmatis, the CS1-based DNA vaccine, or controls, antigen-specific humoral and cellular immune responses were characterized. Vaccination with live recombinant M. smegmatis induced a stronger cellular immune response and a longer period of humoral immune response than with the DNA vaccination. These results indicate that the recombinant M. smegmatis can express efficiently immunogenic CS1 antigen of HBV in vivo, and may be used for the prevention of HBV infection.

Guided selection of an anti-gamma-seminoprotein human Fab for antibody directed enzyme prodrug therapy of prostate cancer.

BACKGROUND: The HAMA response is a major challenge when murine antibodies are repeatedly administered for antibody directed enzyme prodrug therapy in vivo. In this study we have achieved humanization of the anti-gamma-seminoprotein E(4)B(7) murine mAb by guided selection. METHODS: Using optimal Ig Fab primers, human Fd and CL gene repertoires were amplified by RT-PCR from PBMCs of prostate cancer patients. The human Lc gene repertoire was first paired with the murine Fd gene of E(4)B(7) mAb to construct a pComb3X hybrid Fab display library. This hybrid library was screened with purified gamma-seminoprotein antigen. The human Fd gene repertoire was then paired with the selected human Lc to construct a fully human Fab library. After four more rounds of panning, completely human Fab antibodies specific for gamma-seminoprotein were selected and further identified. RESULTS: First, using the E(4)B(7) Fd gene as a template, light chain shuffling was achieved by panning the hybrid library. Then, using the selected Lc as a template, a human Fab antibody against gamma-seminoprotein was produced through heavy chain Fd shuffling. Western blotting, ELISA, and flow cytometry results demonstrated that the resulting human Fab antibody resembled the parental E(4)B(7) mAb in that they both recognized the same epitope with similar affinities. Fluorescent cell staining and immunohistochemistry analysis further confirmed that this newly constructed human anti-gamma-seminoprotein Fab antibody indeed specifically bound prostate cancer cells and tissue. CONCLUSIONS: Through guided-selection, we successfully produced a human anti-gamma-seminoprotein Fab antibody. This work lays the foundation for optimal antibody-directed enzyme prodrug therapy of prostate cancer using a fully human Fab antibody.

[Inhibition of survivin gene expression in PC-3 cells by RNAi].

OBJECTIVE: To construct eukaryotic expression vectors by using the pSilencer3. 1-H1 neo vector for inhibiting human survivin gene by RNA interference, and to detect the effect of the silenced survivin gene on PC-3 cells. METHODS: Three target gene segments were synthesized and cloned into the pSilencer3. 1-H1 neo vector respectively to construct three recombinant eukaryotic expression vectors: pSilencer3. 1-SVV1, pSilencer3. 1-SVV2 and pSilencer3. 1-SVV3, which were identified by enzyme digestion analysis and DNA sequencing. Then the PC-3 cells were transfected with the recombinant vectors and the interference effect detected by RT-PCR, Western blot and immunohistochemical staining. The apoptosis index of the PC-3 cells was detected by flow cytometry and their proliferation detected by MTT method. RESULTS: Enzyme digestion analysis and DNA sequencing showed that three target segments were cloned into pSilencer3. 1-H1-neo vectors. The results of RT-PCR, Western blot and immunohistochemical staining indicated that pSilencer3. 1-SVV2 and pSilencer3. 1-SVV3 vectors could knock down the transcription and expression of survivin gene. After transfected with pSilencer3. 1-SVV2 and pSilencer3. 1-SVV3 vectors, the apoptosis index of the PC-3 cells was increased by 10% - 15% and their growth obviously slowly down. CONCLUSION: The transcription and expression of survivin gene were inhibited effectively by the recombinant eukaryotic expression vectors (pSilencer3. 1-SVV2 and pSilencer3. 1-SVV3) in the prostate cancer cell line PC-3. After transfected with pSilencer3. 1-SVV2 and pSilencer3. 1-SVV3 vectors, the apoptosis index of the PC-3 cells was increased and their growth inhibited.