[Claudin-3 expression in colorectal carcinoma and its significance].

Objective: To investigate the expression of claudin-3 in colorectal carcinoma and its association with the occurrence, progression and prognosis of colorectal cancer.

Methods: Forty surgical specimens of colorectal carcinoma and 22 adjacent normal tissues resected between October, 2010 and January, 2013 at Nanfang Hospital were examined for claudin-3 expression using immunohistochemistry, which was analyzed in association with the clinicopathological parameters and the survival of the patients.

Results: Claudin-3 was expressed mainly on the cell membrane, and its positivity rate was significantly higher in cancer tissues than in normal tissues (92.

Activation of Rho GTPase Cdc42 promotes adhesion and invasion in colorectal cancer cells.

Background: The purpose of this study was to investigate the role of activated Rho GTPase cell division control protein 42 homolog (Cdc42) in colorectal cancer cell adhesion, migration, and invasion.

Material And Methods: The constitutively active form of Cdc42 (GFP-Cdc42L61) or control vector was overexpressed in the colorectal cancer cell line SW480. The localization of active Cdc42 was monitored by immunofluorescence staining, and the effects of active Cdc42 on cell migration and invasion were examined using an attachment assay, a wound healing assay, and a Matrigel migration assay in vitro.

Identification of differential gene expressions in colorectal cancer and polyp by cDNA microarray.

Aim: To screen the differential expressed genes in colorectal cancer and polyp tissue samples.

Methods: Tissue specimens containing 16 cases of colorectal adenocarcinoma and colorectal polyp vs normal mucosae were collected and subjected to cDNA microarray and bioinformatical analyses. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to confirm some of the cDNA microarray data.

[Effect of small interfering RNA targeting Rac1 gene on colony formation of SW480 cells in vitro].

Objective: To construct a vector expressing small interfering RNA (siRNA) against Rac1 gene and observe its effect on soft agar colony formation of SW480 cells in vitro.

Methods: Oligos of 64 base pairs for hairpin RNA targeting Rac1 were chemically synthesized and annealed. The siRNA constructs for Rac1, produced by inserting the annealed oligos into the downstream of H1 promoter of linearized pSUPER, were confirmed by restriction digestion and DNA sequencing.

[Effect of p21-activated kinase-1 on the invasiveness of colorectal carcinoma cells in vitro].

Objective: To observe the effect of p21-activated kinase-1 (PAK1) gene transfection on the invasiveness of human colorectal carcinoma SW480 cells in vitro.

Methods: SW480 cells in routine culture were transfected with the recombinant plasmid EGFP-C1/PAK1 via Lipofectamine(TM) 2000. The expression of PAK1 protein in SW480 cells was detected using Western blotting, and the changes of the invasiveness of SW480 cells were evaluated using Boyden chamber invasion assay.

[Effect of X-ray exposure on soluble tumor necrosis factor receptor-p75 release in hepatocellular carcinoma HepG2 cells in vitro].

Objective: To investigate the effects of X-ray exposure on the release of soluble tumor necrosis factor receptor-p75 (sTNFR-p75) in hepatocellular carcinoma HepG2 cells in vitro.

Methods: Enzyme-linked immunosorbent assay (ELISA) was used to examine the levels of sTNFR-p75 in the supernatants of HepG2 cells before and after X-ray exposure. The cell apoptosis was analyzed by flow cytometry and transmission electron microscope(TEM), and the morphological changes of the cells were examined under optical microscope and transmission electron microscope(TEM).

[Cloning of human migfilin N-terminal domain and preparation of anti-migfilin polyclonal antibody].

Objective: To clone migfilin-N terminal sequence into E.coli and obtain a fusion protein for preparing rabbit polyclonal antibody against migfilin, thereby facilitating the study of the role of migfilin in the biological behavior of colon cancer.

Methods: Based on human migfilin cDNA sequence, a pair of primers was designed to amplify migfilin-N terminal sequence by PCR.

[Role of Rac1 activation in migration and invasion of colorectal cancer cell line SW480].

Objective: To study the role of activation of Rac1 in colorectal cancer cell migration and invasion.

Methods: Rac1 L61 plasmid and control plasmid were transfected into colorectal cancer cell line SW480 cells. Pull down assay by Western blotting was carried out to measure the amount of activited Rac1, and transwell permeable supports were used to assess the migration and invasion of SW480 cells with different activitivity of Rac1.

[X-ray irradiation enhances tumor necrosis factor receptor p55 expression in human colorectal cancer cells and inhibits the release of its soluble form in vitro].

Objective: To investigate the effects of X ray on human colorectal cancer cells for their tumor necrosis factor receptor-p55 (TNFR-p55) expression and release of soluble soluble TNFR-p55 (sTNFR-p55) in vitro.

Methods: The protein expression of TNFR-p55 in Lovo cells exposed to X-ray was detected using immunohistochemistry, and enzyme-linked immunosorbent assay was used to examine the levels of sTNFR-p55 in the supernatants of the cell culture. The cell apoptosis of the exposed cells was analyzed with flow cytometry, and the changes in cell morphology were observed microscopically.

[Short hairpin RNA-mediated survivin gene silencing inhibits invasion and metastasis of human colon carcinoma cell line SW480 in vitro].

Objective: To investigate the effect of short hairpin RNA (shRNA) targeting survivin on adhesion and invasion of human colon carcinoma cell line SW480 in vitro.

Methods: According to the sequence of the coding region of survivin gene, two strings of 19 nucleotides of inverted sequence flanking the loop sequence of two complementary 9-base oligonucleotides were designed and synthesized to prepare the hairpin construct as the DNA templates for the target shRNA. The shRNA templates were cloned into shRNA expression vector pRNAT-U6.

[Expressions of tumor necrosis factor receptor I and II in human gastric carcinoma].

Objective: To study the clinical significance of expressions of tumor necrosis factor receptor I and II(TNFR I and II) and their relationship with clinical pathology in human gastric carcinoma.

Methods: SABC immunohistochemical method was used to examine the expressions of TNFR I and II in 51 cases of gastric carcinoma, 41 adjacent mucosal and 15 normal gastric mucosa tissues.

Results: The positivity rates of TNFR I and II expressions in human gastric carcinoma were significantly higher than those in the adjacent mucosal and normal mucosal tissues, and their expressions were significantly higher in the surrounding mucosa than in the normal tissues.

[Effects of recombinant Helicobacter pylori catalase on oxidative stress in colonic mucosal epithelial cells].

Objective: To investigate the effects of recombinant Helicobacter pylori catalase (rHpCAT)on oxidative stress in rat colonic mucosal epithelial cells.

Methods: Oxidative stress model was established by hydroxyl generated from Fenton reaction in cultured colonic mucosal epithelial cells isolated from normal rats, in the model of which the effects of rHpCAT were observed. The cells were divided into normal control, model, 5-aminosalicylic acid (5-ASA, 0.

[Expression of tumor necrosis factor receptor on peripheral blood mononuclear cells from patients with primary hepatocellular carcinoma and effects of treatment on the expression].

Objective: To conduct an intensive investigation of the abnormal immune status of patients with primary hepatocellular carcinoma and explore the possible mechanism of biotherapy for these patients.

Methods: The expression of tumor necrosis factor receptor (TNFR)I and TNFR II on peripheral blood mononuclear cells (PBMCs) obtained from 30 normal subjects and 31 patients with primary hepatocellular carcinoma were examined by flow cytometry and S-P staining assay. The effects of biotherapy and chemotherapy administered in the patients were also investigated in terms of the changes in the expressions.

Detection of soluble tumor necrosis factor-p55 levels in the serum and ascitic fluid of patients with hepatocellular carcinoma.

Objective: To examine soluble tumor necrosis factor receptor-p55 (sTNFR-p55) levels in the serum and ascitic fluid and investigate the significance of this examination in assessment of the clinical status of patients with primary hepatocellular carcinoma (HCC).

Methods: Enzyme-linked immunosorbent assay (ELISA) was used to examine sTNFR-p55 levels in the serum and ascitic fluid in 25 patients with HCC and 25 with liver cirrhosis (LC).

Results: sTNFR-p55 levels in the serum and ascitic fluid in patients with HCC were significantly higher than those in patients with LC and controls (P=0.