[Detection of interferon-induced transmembrane-1 gene expression for clinical diagnosis of colorectal cancer].

OBJECTIVE: To investigate the expression of the interferon-induced transmembrane-1 (IFITM1) gene in colorectal cancer (CRC) tissue and the serum anti-IFITM1 antibody responses of the patients and assess their value in clinical diagnosis of CRC. METHODS: Semi-quantitative RT-PCR was performed to detect IFITM1 mRNA expression in the specimens of normal colonic mucosa, CRC tissue, inflammatory polyps, adenomatous polyps, gastric cancer, esophageal carcinoma and liver cancer tissues. Serum samples were collected from the patients to detect anti-IFITM1 antibody responses using Western blotting. The clinicopathological features of the carcinoma expressing IFITM1 gene were analyzed. RESULTS: IFITM1 mRNA was expressed in 47.4 % (18/38) of the CRC specimens, a rate significantly higher than that in adenomatous polyps [15% (3/20)] and gastric cancer [4.8% (1/21)]; no obvious IFITM1 expression was found in normal colonic mucosa, inflammatory polyp, esophageal carcinoma or liver cancer tissues (P<0.001 or P<0.05). IFITM1 mRNA was strongly expressed in CRC at the expression level of 0.8048-/+0.2273, which was significantly higher than that in adenomatous polyps (0.4447-/+0.0989, P<0.001). No anti-IFITM1 antibody response was detected in healthy human sera, but in the CRC patients, the serum antibody response was detected at the rate of 36.8% (14/38), significantly higher than the rate of 9.5% (2/21) in gastric cancer (P<0.05). No antibody response was detected in esophageal carcinoma, liver cancer, inflammatory polyp or adenomatous polyps. Most of the IFITM1-expressing CRC had a diameter exceeding 5 cm, often invading the serous membrane with metastasis to the lymph nodes and the distant organs; these tumors were identified mostly as well-differentiated adenocarcinoma in Dukes stage C or D. CONCLUSION: IFITM1 gene may play an important role in the pathogenesis, development and metastasis of CRC, and may serve as a potential biomarker for clinical diagnosis of CRC.

[Expression of CD117, CD34, SMA, S-100 protein, Vim and desmin in patients with gastrointestinal stromal tumors].

OBJECTIVE: To investigate the clinicopathological diagnosis and expressions of CD117, CD34, SMA, S-100 protein, Vimentin(Vim) and desmin in gastrointestinal stromal tumors (GISTs). METHODS: A retrospective analysis of the clinical data and the results of various examinations was conducted among 35 patients with pathologically confirmed GISTs undergoing surgical resection. The expressions of CD117, CD34, SMA, S-100, Vim and desmin in the tumor tissues were detected by immunohistochemistry with SP method. RESULTS: In these GIST cases, the tumors were located mostly in the stomach (n=11), small intestines (n=11), and abdominal cavity (n=5). The main clinical manifestations included abdominal distension, abdominal pain, gastrointestinal bleeding, and abdominal masses. The positivity rates of CD117 and CD34 in the tumors were 94.3% and 91.4%, respectively, both significantly higher than those of SMA, S-100, Vim and Desmin (P<0.001), and also higher than that in leiomyoma (P<0.0001). The positivity rate of Desmin was only 2.9% in the tumors, significantly lower than those of CD117 and CD34 (P<0.05) and that in liomyoma (P<0.001). CONCLUSIONS: GISTs occur mostly in the stomach and small intestines, and endoscopy, ultrasound endoscope and CT examination are effective modalities for diagnosis of GISTs. A definite diagnosis of GISTs can be established in the presence of positive expression of CD117 and CD34 and negative expression of Desmin in the tumor.

[Screening and preliminary analysis of colorectal carcinoma-associated antigen genes].

OBJECTIVE: To screen and identify the genes coding for colorectal carcinoma-associated antigen and analyze the bioinformation of their cDNA sequences. METHODS: Immunoscreening of the cDNA phage-display library derived from human colorectal carcinoma was performed with autologous or allogeneic serum antibody from patients with colorectal cancer through SEREX approach. After amplification of the positive phage clones, the phage DNA was extracted and purified with Qiagen kit, and the fragment sizes of the cDNA of positive clones were identified by PCR and EcoR I and Hind III restriction endonucleases. The cDNAs of the positive clones were ligated into pUCm-T vector and sequenced. The bioinformation of cDNA sequences were analyzed against GenBank+EMBL+DDBJ+PDB Sequences Database. RESULTS AND CONCLUSION: Eleven positive clones were obtained after immunoscreening, and the sizes of the cDNA fragments were 1100, 1300, 1000, 2000, 1200, 1200, 700, 900, 600, 1200 and 1000 bp, respectively, representing 9 antigen genes, including 7 with homology with the known genes. Among the 11 obtained positive clones, 3 were the same cDNA having homology with interferon-induced transmembrance protein-1 and possessing anti-proliferation effect; another 6 represented different genes, namely human BAC clone RP11-453E17 whose function have not been cleared, human cartilage-hair hypoplasia region gene responsible for cartilage-hair hypoplasia, human chromosome 5 clone CTD-2030B15 with insertion mutation, human gene similar to anti tumor necrosis factor-alpha antibody light-chain Fab fragment associated with tumor growth, mRNA of human beta-2-microglobulin in relation to tumor cell proliferation, and human aldolase A gene promoting tumor cell proliferation. The other two cDNA sequences were not identified for homology with currently known genes in GenBank, and their functions awaits further investigation.

[PCR amplification, cloning and protein expression of interferon-inducible transmembrane protein-1 gene].

OBJECTIVE: To study the PCR amplification, cloning and protein expression of interferon-inducible transmembrane protein-1 (IFITMP-1) gene. METHODS: With the cDNA fragment containing IFITMP-1 gene as template, IFITMP-1 gene was amplified using Pfu enzyme by means of PCR. After EcoRI and HindIII digestion, the target gene fragment was linked to pUCm-T plasmid and sequenced. The IFITMP-1 gene was cloned into pET-Trx protein expression plasmid, and the condition for protein expression was optimized. RESULTS: The length of the PCR product of IFITMP-1 gene-containing cDNA fragment was about 1000 bp. The IFITMP-1 gene was successfully inserted into pUCm-T plasmid with correct sequence and cloning of the IFITMP-1 gene into the pET-Trx protein expression plasmid was achieved. Expression of the fusion protein of pUCm-T plasmid and IFITMP-1 gene was detected after IPTG induction. CONCLUSION: Successful amplification and cloning of the IFITMP-1 gene and its protein expression may facilitate further study of the role of IFITMP-1 gene in colorectal cancer.

Oral immunization of mice with vaccine of attenuated Salmonella typhimurium expressing Helicobacter pylori urease B subunit.

OBJECTIVE: To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacter pylori (H. pylori) B subunit (UreB) and to determine whether it could be used as an oral vaccine against H. pylori infection. METHODS: Using genomic DNA of H. pylori Sydney strain (SSI) as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LB5000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups (including body weight, gastric inflammation, etc.) were also collected. RESULTS: The sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H. pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-gamma and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed. CONCLUSION: The attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection.

Effects of probiotic on intestinal mucosa of patients with ulcerative colitis.

AIM: To investigate the effects of probiotic on intestinal mucosae of patients with ulcerative colitis (UC), and to evaluate the role of probiotic in preventing the relapse of UC. METHODS: Thirty patients received treatment with sulphasalazine (SASP) and glucocorticoid and then were randomly administered bifid triple viable capsule (BIFICO) (1.26 g/d), or an identical placebo (starch) for 8 wk. Fecal samples were collected for stool culture 2 wk before and after the randomized treatments. The patients were evaluated clinically, endoscopically and histologically after 2 mo of treatment or in case of relapse of UC. p65 and IkappaB expressions were determined by Western blot analysis. DNA-binding activity of NF-kappaB in colonic nuclear extracts was detected by electrophoretic mobility shift assay (EMSA). mRNA expressions of cytokines were identified by semi-quantitative assay, reverse transcriptase- polymerase chain reaction (RT-PCR). RESULTS: Three patients (20%) in the BIFICO group had relapses during 2-mo follow-up period, compared with 14 (93.3%) in placebo group (P<0.01). The concentration of fecal lactobacilli, bifidobacteria was significantly increased in BIFICO-treated group only (P<0.01). The expressions of NF-kappaB p65 and DNA binding activity of NF-kappaB were significantly attenuated in the treatment group than that in control (P<0.05). The mRNA expression of anti-inflammatory cytokines was elevated in comparison with the control group. CONCLUSION: The probiotic could impede the activation of NF-kappaB, decrease the expressions of TNF-alpha and IL-1beta and elevate the expression of IL-10. These results suggest that oral administration of this new probiotic preparation is effective in preventing flare-ups of chronic UC. It may become a prophylactic drug to decrease the relapse of UC.

Establishment of the methods for searching eukaryotic gene cis-regulatory modules.

On the basis of the knowledge of eukaryotic gene regulation, we modified the method in three aspects: (1) Searching the cis-regulatory modules (CRM) according Fasta or Blast sequence with multiple sequence and low E value, followed by mutual scoring of these sequence with Smith-Waterman algorithms and finally by clustering analysis; (2) Searching the transcription factor-binding site using International Union of Pure and Applied Chemistry, Position-Weight Matrix(PWM) and Dyed method; (3) Designing and implementation of data analysis based on the software in Windows 2000 and UNIX using object-oriented technology. The results of analysis of the major histocompatibility complex gene family show that this procedure may accurately locate the regions that contain some of the CRMs.

Effect of eIF-4E inhibition on heparanase mRNA and its expression in colon adenocarcinoma cell.

OBJECTIVE: To verify whether inhibition of the overexpressed eukaryotic initiation factor-4E (eIF-4E) in human colon adenocarcinoma cell line LS-174T may facilitate the degradation of heparanase mRNA and alter the translation and expression levels of heparanase protein. METHODS: A 20-mer antisense s-oligodeoxynucleotide (asODN) targeted against the translation start site of eIF-4E mRNA was introduced into LS-174T cells by means of lipid-mediated DNA-transfection, followed by Western blotting analysis and reverse transcription-PCR to determine eIF-4E protein and mRNA levels, respectively. Northern methods was applied to determine heparanase mRNA expression level, with the alterations of heparanase expression assessed by Western blotting analysis. RESULTS: The 20-mer asODN against eIF-4E specifically and significantly inhibited eIF-4E protein expression, and as a result, a significant reduction in heparanase mRNA level was observed by Northern blotting in conjunction with significantly decreased heparanase protein expression. CONCLUSION: The inhibition of eIF-4E strongly reduces the stability of heparanase mRNA in colon adenocarcinoma cell line LS-174T and results in an apparent reduction in the expression of heparanase protein.

[Construction and identification of the cDNA phage expression library for human colorectal cancer antigens].

OBJECTIVE: To construct a cDNA phage expression library for human colorectal carcinoma antigens. METHODS: After the total RNA was extracted from human colorectal cancer tissues, the single-strand and double-strand cDNA were synthesized through reverse transcriptase PCR and long-distance PCR, with the cDNA fragments smaller than 500 bp removed and the remaining cDNA combined with the right and left arms of dephosphorylated lambdaTriplEx2 phage vector. The recombinant phage were then packaged in vitro by MaxPlax Packaging extract, and a small portion of the packaged phage was used to infect E.coli XL1-Blue. Titer measurement was performed so as to determine the capacity of the library. SfiI restriction endonucleases was used to cut the recombined phage DNA in order to identify the size of inserted cDNA. RESULTS: The constructed cDNA phage expression library for human colorectal cancer antigens consisted of 2.39 x 10(6) pfu/ml bacteriophages with a recombination rate of 97.5% and the length of the inserted cDNA fragment ranged from 600 to 4,000 bp with an average of 1,400 bp. CONCLUSION: The cDNA phage expression library of human colorectal cancer antigens is successfully constructed to meet the currently recognized standards, and can be well applicable in screening cDNA-cloned genes of human colorectal cancer-associated antigens by immunoscreening.

Pleckstrin homology domain of G protein-coupled receptor kinase-2 binds to PKC and affects the activity of PKC kinase.

AIM: To study the detail mechanism of interaction between PKC and GRK(2) and the effect of GRK(2) on activity of PKC. METHODS: The cDNA of pleckstrin homology (PH) domain located in GRK(2) residue 548 to 660 was amplified by PCR with the mRNA of human GRK(2) (beta1-adrenergic receptor kinase) as template isolated from human fresh placenta, the expression vector pGEX-PH inserted with the aboved cDNA sequence for GRK(2) PH domain protein and the expression vectors for GST (glutathion-s-transferase) -GRK(2) PH domain fusion protein, BTK (Bruton's tyrosine kinase) PH domain and GST protein were constructed. The expression of GRK(2) in culture mammalian cells (6 cell lines: PC-3, MDCK, SGC7901, Jurkat cell etc.) was determined by SDS-PAGE and Co-immunoprecipitation. The binding of GRK(2) PH domain, GST-GRK(2) PH domain fusion protein and BTK PH domain to PKC in Vitro were detected by SDS-PAGE and Western blot, upon prolonged stimulation of epinephrine, the binding of GRK(2) to PKC was also detected by western blot and Co-immunoprecipitation. RESULTS: The binding of GRK(2) PH domain to PKC in Vitro was confirmed by western blot, as were the binding upon prolonged stimulation of epinephrine and the binding of BTK PH domain to PKC. In the present study, GRK(2) PH domain was associated with PKC and down-regulated PKC activity, but Btk PH domain up-regulated PKC activity as compared with GRK(2) PH domain. CONCLUSION: GRK(2) can bind with PKC and down-regulated PKC activity.