ABSTRACT
<p><b>OBJECTIVE</b>To construct a human testis cDNA library for yeast two-hybrid screening.</p><p><b>METHODS</b>Human normal testis mRNA was purified from total RNA, and ds cDNA was synthesized and amplified using primers SMART III and CDS III oligo (dT) as the base of recombination. The purified PCR products and linearized plasmid pGADT7-Rec were co-transformed into the competent yeast Y187 and recombined by yeast homologous recombinase in the yeast cells to form an active cyclic plasmid. All the clones growing on the SD/-Leu plates were harvested to constitute a human testis cDNA library.</p><p><b>RESULTS</b>We constructed a human testis cDNA library with high multiplication and adequate capacity, from which 2.0 x 10(6) recombinants were obtained. The amplified PCR fragments were between 0.3 kb and 4.0 kb in length.</p><p><b>CONCLUSION</b>The yeast two-hybrid cDNA library of human testis was successfully constructed by the Clontech SMART method, which has prepared a ground for further studies on the molecular mechanism of spermatogenesis.</p>
Subject(s)
Humans , Male , DNA Primers , Genetics , DNA, Complementary , Gene Library , Hybridization, Genetic , Plasmids , Testis , Two-Hybrid System TechniquesABSTRACT
<p><b>OBJECTIVE</b>To screen and identify PIAS2-interacting proteins from the mouse spermatogonial cDNA library using the yeast two-hybrid system, and to investigate the action mechanism of PIAS2 in spermatogenesis.</p><p><b>METHODS</b>With pGBKT7-PIAS2 as a bait plasmid, the positive clones interacting with pGBKT7-PIAS2 were screened from the mouse spermatogonial cDNA library, the inserted fragments were sequenced and underwent bioinformatic analysis, and their interaction was verified using the yeast two-hybrid system.</p><p><b>RESULTS</b>Through screening, sequencing, homology analysis and yeast two-hybrid verification, we obtained 8 different candidate proteins interacting with PIAS2, including Cyfip2, Psmb3, Nmel, nischarin, Ints10, Nsun5, Gnb211 and Ndufaf3.</p><p><b>CONCLUSION</b>Eight different genes were successfully obtained using the yeast two-hybrid system, and their encoding proteins interacted with PIAS2, which might be related with male fertility regulation. Our findings have offered some new clues to the action mechanism of PIAS2 in spermatogenesis.</p>
Subject(s)
Animals , Male , Mice , Base Sequence , Gene Library , Protein Binding , Protein Inhibitors of Activated STAT , Genetics , Protein Interaction Domains and Motifs , Spermatogenesis , Genetics , Spermatogonia , Metabolism , Two-Hybrid System TechniquesABSTRACT
<p><b>BACKGROUND</b>We have previously found that connective tissue growth factor (CTGF) is highly expressed in a rat model of liver cancer. Here, we examined expression of CTGF in human hepatocellular carcinoma (HCC) cells and its effect on cell growth.</p><p><b>METHODS</b>Real-time PCR was used to observe expression of CTGF in human HCC cell lines HepG2, SMMC-7721, MHCC-97H and LO2. siRNA for the CTGF gene was designed, synthesized and cloned into a Plk0.1-GFP-SP6 vector to construct a lentivirus-mediated shRNA/CTGF. CTGF mRNA and protein expression in HepG2 cells treated by CTGF-specific shRNA was evaluated by real-time PCR and Western blotting. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was utilized to evaluate the growth effect, and a colony formation assay was used for observing clonogenic growth. In vivo, tumor cell proliferation was evaluated in a nude mouse model of xenotransplantation. Statistical significance was determined by t test for comparison between two groups, or analysis of variance (ANOVA) for multiple groups.</p><p><b>RESULTS</b>Immunohistochemical staining of CTGF was seen in 35 of 40 HCC samples (87.5%). CTGF was overexpressed 5-fold in 20 HCC tissues, compared with surrounding non-tumor liver tissue. CTGF mRNA level was 5 - 8-fold higher in HepG2, SMMC-7721 and MHCC-97H than in LO2 cells. This indicated that the inhibition rate of cell growth was 43% after knockdown of CTGF expression (P < 0.05). Soft agar colony formation assay showed that siRNA mediated knockdown of CTGF inhibited colony formation in soft agar of HepG2 cells (P < 0.05). The volume of tumors from CTGF-shRNA-expressing cells only accounted for 35% of the tumors from the scrambled control-infected HepG2 cells (P < 0.05).</p><p><b>CONCLUSIONS</b>CTGF was overexpressed in human HCC cells and downregulation of CTGF inhibited HCC growth in vitro and in vivo. Knockdown of CTGF may be a potential therapeutic strategy for treatment of HCC.</p>