Progression in metastasis of colorectal carcinoma / 浙江大学学报·医学版

Globally, the incidence of colorectal carcinoma (CRC) ranks the third among all cancers. The incidence of CRC is continually increasing in China. Invasion and metastasis are the major causes of death. Metastasis is a complex multistep malignant process, including the detachment of tumor cells from the primary site, interaction of tumor cells with the surrounding extracellular matrix, entering into the circulation or lymph system, adhesion to the endothelial cells of vascular wall, migration of tumor cells into secondary sites, angiogenesis and formation of new metastases. This article reviews the recent research progress in aspects of the metastasis related genes, microRNAs, epithelial mesenchymal transition, tumor stem cells, and micro environment of colorectal cancer.

Resistance to apoptosis should not be taken as a hallmark of cancer / 癌症

In the research community, resistance to apoptosis is often considered a hallmark of cancer. However, pathologists who diagnose cancer via microscope often see the opposite. Indeed, increased apoptosis and mitosis are usually observed simultaneously in cancerous lesions. Studies have shown that increased apoptosis is associated with cancer aggressiveness and poor clinical outcome. Furthermore, overexpression of Bcl-2, an antiapoptotic protein, is linked with better survival of cancer patients. Conversely, Bax, CD95, Caspase-3, and other apoptosis-inducing proteins have been found to promote carcinogenesis. This notion of the role of apoptosis in cancer is not new; cancer cells were found to be short-lived 88 years ago. Given these observations, resistance to apoptosis should not be considered a hallmark of cancer.

Infantile DiGeorge syndrome: autopsy diagnosis and clinicopathologic analysis in 5 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate clinicopathological features of DiGeorge syndrome (DGS).</p><p><b>METHOD</b>The clinical features, histological and immunohistochemical findings were analyzed in 5 cases of DGS by autopsy.</p><p><b>RESULTS</b>Five cases of DGS in male infants aged 4 days, 1 month, 7 months, 10 months, and 13 months respectively. Gross and microscopic observations revealed that thymic cortex was depleted of lymphocytes or showed few, dispersed lymphocytes. The thymic medulla showed predominantly epithelial cells with calcified Hassall bodies as well as lymphocyte depletion. T lymphocytes were also scarce in the tonsils, lymph nodes, spleen, and mucosa-associated lymphatic tissue of ileum. In addition, 3 of the 5 patients also showed parathyroid aplasia or dysplasia, and congenital hypertrophy of the ventricular septum.</p><p><b>CONCLUSIONS</b>The pathological changes indicate that clinicians should be aware of defects of immune system if the infants suffer from severe infections. Pathologists should recognize the importance of abnormalities of lymphohematopoietic tissues in the diagnosis of primary immunodeficiency diseases such as DGS.</p>

Construction of a PCR chip for detecting genes associated with metastatic colorectal cancer and its preliminary application / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a PCR chip with a gene panel for predicting and diagnosing metastatic colorectal cancer.</p><p><b>METHODS</b>The PCR chip was constructed by integrating 29 genes related to colorectal cancer metastasis identified by gene chip analysis and 3 housekeeping genes into a gene panel. The PCR chip was used for detecting the mRNA expressions of the integrated genes in colorectal cell lines, cancerous specimen and adjacent normal mucosa. The primers for amplification were refined and optimized by several rounds of preliminary reactions.</p><p><b>RESULTS</b>The PCR chip containing the 29 candidate genes and 3 housekeeping genes was successfully constructed, which showed specific amplifications of the genes. The results of the PCR chip for detecting the mRNA of the 29 genes related to colorectal cancer metastasis showed a concordance rate of 86% (25 out of 29) with the gene chip data. Application of the PCR chip in the examination of the clinical specimens identified 15 differentially expressed genes between metastatic colorectal cancer and colorectal cancer without metastasis.</p><p><b>CONCLUSION</b>The constructed PCR chip is reliable in the prediction of metastasis of colorectal cancer, and provides a molecular means for evaluating the prognosis of colorectal cancer metastasis.</p>

Pathogenic and tumorigenic effect of 1,2-dimethylhydrazine in mouse colon and ovarian / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the pathogenic and tumorigenic effect of 1,2-dimethylhydrazine (DMH) on the colon and ovaries of mice.</p><p><b>METHODS</b>Sixty ICR female mice were randomly divided into groups A and B for intraperitoneal injection of DMH (20 mg/kg) and saline (control) once a week for 24 weeks, respectively. The mice were sacrificed at 12, 16, 20, 24, 28 and 32 weeks after the first DMH injection for pathological examination of the colon and ovaries.</p><p><b>RESULTS</b>In group A, colorectal adenomas were found in 7, colorectal adenocarcinomas in 5, and hemorrhagic lesions of the ovaries with chronic inflammatory in 21 mice. Choriocarcinoma in the ovaries were detected in one mouse at 28 weeks and in another at 32 weeks. No obvious pathological changes were found in group B following the injections.</p><p><b>CONCLUSION</b>Intraperitoneal injection of DMH may induce colon tumors and ovarian diseases in mice.</p>

Impact of LASP-1 expression on proliferation and tumorigenesis of human colorectal cancer cell line SW480 / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of LIM and SH3 protein 1 (LASP-1) expression on the proliferative ability of human colorectal cancer cells in vitro and in vivo.</p><p><b>METHODS</b>RT-PCR and Western blot were used to screen cells of the colorectal cancer cell line with no or with minimal endogenous LASP-1 expression. LASP-1 cDNA with or without GFP was transfected into SW480 colorectal cancer cells with minimal LASP-1 expression. Stable transfectants were established after G418 selection. Cell proliferative capacity was assessed by MTT assay. Tumor growth was visualized by whole-body imaging system.</p><p><b>RESULTS</b>pcDNA3-LASP-1 and pEGFP-LASP-1 vectors were successfully constructed and transfected into the SW480 cells. After comparative study for 7 days, LASP-1 over-expression was found capable of enhancing significantly the proliferation of colorectal cancer cells in vitro. Stable transfectants with GFP expression were inoculated subcutaneously into the nude mice. Tumorigenesis and proliferation ability of LASP-1-overexpressed transfectants were higher than those of the control cells.</p><p><b>CONCLUSION</b>LASP-1 gene expression enhances proliferation of colorectal cancer cells and may serve as a useful marker for colorectal cancer progression.</p>

Celecoxib induces cell cycle arrest and apoptosis in human tongue squamous carcinoma cell line Tca8113 / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of celecoxib on the cell cycle and apoptosis in human tongue squamous cell carcinoma (HTSCC) cell line Tca8113.</p><p><b>METHODS</b>Tca8113 cell line was cultured in the presence of different concentrations of celecoxib. MTT assay was used to measure cell survival rate, and flow cytometry performed to analyze the cell cycle distribution. Annexin V-FITC/PI staining was used to detect the early changes of apoptosis, and transmission electron microscope employed to observe the ultrastructural changes of the apoptotic cells.</p><p><b>RESULTS</b>Celecoxib inhibited the proliferation of Tca8113 cells in a dose-dependent manner, the effect of which was mediated by inducing cell cycle arrest mainly in G1/S phase. Flow cytometry and ultrastructural observation demonstrated an early to late stage changes of the apoptotic cells exposed to increased concentrations of celecoxib.</p><p><b>CONCLUSION</b>Celecoxib dose-dependently inhibits the proliferation of Tca8113 cells by causing cell cycle arrest and inducing apoptosis.</p>

Effect of Celecoxib on cycloxygenase-2 expression and inducing apoptosis in Tca8113 cell lines / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe whether Celecoxib could inhibit the growth, regulate the expression of COX-2 and induce apoptosis of Tca8113 cells.</p><p><b>METHODS</b>Tca8113 cells were incubated with different concentrations of Celecoxib for 24, 48 and 72 h, and MTT was used to calculate growth inhibition rate. The expression of COX-2 protein and mRNA in Tca8113 cells was detected with SP immunohistochemistry staining and fluorescent quantitative real-time RT-PCR. Morphology of apoptosis cells was observed by fluorescence microscopy, and Annexin V-FITC/PI double labeling method was employed to detect early stage cell apoptosis.</p><p><b>RESULTS</b>COX-2 protein was strongly expressed in Tca8113 cells and was suppressed by Celecoxib. The growth and proliferation of Tca8113 cells treated with Celecoxib were inhibited in a dose-dependent manner. Celecoxib treatment resulted in significant increase in apoptosis and early apoptotic rate. Fluorescent quantitative real-time RT-PCR results showed no significant effet on regulating expression of COX-2 mRNA.</p><p><b>CONCLUSION</b>Celecoxib shows a significant effect on inhibiting expression of COX-2 in Tca8113 cells, this is probably related to growth inhibition and inducing apoptosis of Tca8113 cells.</p>

Effects of protein kinase CK2alpha on the proliferation and invasion of human nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of protein kinase CK2alpha expression on the proliferation and invasion of human nasopharyngeal carcinoma and related mechanism.</p><p><b>METHODS</b>RNA interference (RNAi) was used to down-regulate the protein kinase CK2alpha expression in 5-8F cells. The biological behavior of treated cells were analyzed by MTT and in-vitro invasion assays. Cell proliferation cycle was examined by flow cytometry and the phosphorylation status of Akt protein was examined by Western blotting analysis.</p><p><b>RESULTS</b>CK2alpha protein was successfully silenced by siRNA. CK2alpha knockdown significantly decreased the proliferative and invasive abilities of 5-8F cells. Flow cytometry analysis showed that the percentage of cells increased in G(0)/G(1) phase but decreased in S phase. Moreover, the expression of phosphorylated Akt was down-regulated by CK2alpha silencing.</p><p><b>CONCLUSION</b>Protein kinase CK2alpha plays an important role in the proliferation and invasion of nasopharyngeal carcinoma, and may provide a potential therapeutic target against nasopharyngeal cancer.</p>

Expression of ZNF217 in human ovarian cystadenocarcinoma and its clinical significance / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the correlation of ZNF217 expression to the carcinogenesis and progression of human ovarian cancer.</p><p><b>METHODS</b>Immunohistochemistry and real-time RT-PCR were used to detect ZNF217 expression in human ovarian cystadenocarcinoma, ovarian cystadenoma and normal ovary tissues.</p><p><b>RESULTS</b>The expression levels of ZNF217 protein and mRNA in ovarian cystadenocarcinoma was significantly higher than those in matched ovarian cystadenoma and normal tissues (P<0.05). No significant difference was found in the expression between ovarian cystadenoma and normal ovarian tissues (P>0.05). The mRNA expression in the specimens was consistent with the protein expression of ZNF217 (P<0.05).</p><p><b>CONCLUSION</b>ZNF217 gene expression is closely correlated to the occurrence and clinical stages of ovarian carcinomas, suggesting that ZNF217 can be an important candidate gene responsible for the occurrence and progression of ovarian carcinomas.</p>

Expressions of metastatic tumor antigen 1 and hypoxia-inducible-factor l alpha in lung cancer and their clinical significance / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the correlation of the expressions of metastatic tumor antigen 1 (MTA1) and hypoxia-inducible-factor l alpha (HIF-1alpha) to the clinical features of lung cancer.</p><p><b>METHODS</b>The expressions of MTA1 and HIF-1alpha proteins in 59 lung cancer patients were detected by immunohistochemistry.</p><p><b>RESULTS</b>Positive staining of MTA1 and HIF-1alpha was found in 54.24% and 50.85% of the patients, respectively. MTA1 expression was not found to correlated to any of the clinical parameters. HIF-1alpha expression was significantly lower in poorly differentiated than in moderately and well differentiated lung cancer (P<0.05), and a positive association between the expressions of MTA1 and HIF-17alpha were noted (P<0.05).</p><p><b>CONCLUSION</b>MTA1 and HIF-1alpha overexpression occurs in lung cancer possibly as an important factor of lung carcinogenesis. MTA1 may promote lung carcinogenesis by enhancing HIF-1alpha protein activity.</p>

Establishment of a colorectal cancer cell line with PRL-3 and CDH22 gene knock-down by lentivirus-mediated RNA interference / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a colorectal cancer cell line with stable PRL-3 and CDH22 gene knock-down for investigating the role of PRL-3 and CDH22 genes in the carcinogenesis and metastasis of colorectal cancer.</p><p><b>METHODS</b>A recombinant lentiviral vector targeting CDH22 gene was obtained using the pENTRTM/U6 construct and pLenti6/BLOCK-iT (TM)-DEST vector. The recombinant lentivirus was harvested from 293FT cells cotransfected with the optimized ViraPower(TM) Packaging Mix and the pLenti6/BLOCK-iT(TM)-DEST expression construct. SW480/PRL-3- cells were infected with the recombinant lentivirus targeting CDH22, and SW480 cells with stable PRL-3 and CDH22 knock-down were screened by blasticidin selection. PRL-3 expression in the cells was determined by real-time RT-PCR. RESULTS The titer of the lentivirus for the second infection was 8 x 10(5) U/ml. Seventeen positive clones were selected, among which the Clone 1 exhibited substantially down-regulated CDH22 and PRL-3 mRNA expressions.</p><p><b>CONCLUSIONS</b>A human colorectal cancer cell line with stable PRL-3 and CDH22 gene knock-down has been established.</p>

Effects of celecoxib on PGE2 synthesis and COX-2 and VEGF-C mRNA expression in Tca8113 cell lines / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib on prostaglandin E(2) (PGE2) release and vascular endothelial growth factor C (VEGF-C) and COX-2 mRNA expression in Tca8113 cell lines.</p><p><b>METHODS</b>MTT assay was used to analyze the proliferation of Tca8113 cells. The PGE2 level was detected with enzyme-linked immunosorbent assay (ELISA), and the expressions of COX-2 and VEGF-C mRNA were examined with RT-PCR.</p><p><b>RESULTS</b>Celecoxib could induce inhibitory effects on the growth and PGE2 release in Tca8113 cells. The RT-PCR results showed that celecoxib significantly down-regulated the expression of VEGF-C mRNA, but produced a weak effect on COX-2 mRNA expression.</p><p><b>CONCLUSION</b>The inhibitory effect of celecoxib on Tca8113 cell growth and the expressions of VEGF-C and COX-2 may be related to the release of PGE2.</p>

Magnetic resonance myocardial perfusion imaging for evaluating myocardial viability after myocardial infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the value of magnetic resonance (MR) myocardial perfusion imaging (MRMPI) in evaluating the myocardial viability in patients with myocardial infarction.</p><p><b>METHODS</b>MRMPI was performed in 51 patients with myocardial infarction using a 1.5 T MR scanner. All the patients were examined using IR-turbo FLASH sequence during the first-pass and delayed phase 5-30 min after injection of 0.1 mmol/kg Gd-DTPA at the rate of 4 ml/s. The short axis images were acquired during the first-pass, and both the short axis and long axis images were obtained during the delayed phase. The left ventricular wall on the short-axis slice was divided into 8 segments. A correlative study of the results of the rest and stress (99m)Tc single photon emission computed tomography (SPECT) was carried out in 21 patients.</p><p><b>RESULTS</b>In the 51 patients with myocardial infarction, 42(82.3%) showed hypoperfusion during the first-pass imaging and 50(98%) had delayed hyperenhancement. In the 21 patients receiving SPECT, 48 nonviable segments was detected among the 168 segments scanned by (99m)TcSPECT, and MRMPI showed delayed hyperenhancement in all the infracted areas. Of the 120 viable segments detected by rest and stress (99m)Tc SPECT, 97 segments (80.8%) were found to be free of delayed hyperenhancement by MRMPI. With the rest and stress (99m)Tc SPECT as the reference, the sensitivity and the specificity of MRMPI were 100.0% and 80.8%, respectively.</p><p><b>CONCLUSION</b>MRMPI allows effective identification of the myocardial viability and nonviability as well as the severity and extent of the myocardial infraction.</p>

Relationship between Tiam-1 expression and the biological behaviors of nasopharyngeal carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the relationship between the protein expression of T-lymphoma invasion and metastasis gene 1 (Tiam-1) and the biological behaviors of nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>Immunohistochemistry was performed to detect the expressions of Tiam-1 protein in 60 specimens of NPC tissue, 20 specimens of chronic nasopharyngitis (CN) tissue, and 6 tumor tissues from nude mice inoculated with metastatic human NPC cells.</p><p><b>RESULTS</b>The positivity rate and average score for Tiam-1 expression were significantly higher in NPC tissues than in CN tissue (63.33% vs 36.67%, 2.9167 +/- 1.3057 vs 0.7000 +/- 0.9234; chi(2)=20.429, P=0.001; t=7.0162, P=0.0000, respectively). No difference was found in Tiam-1 expression among NPC patients in different T stages (F=2.36, P=0.0811), while the expression differed significantly between the patients with lymph node metastasis and those without metastasis, and also between patients with organ metastasis and those without (P=0.0001). High Tiam-1 expressions were found in the tumor tissues in nude mice inoculated with metastatic NPC cells.</p><p><b>CONCLUSION</b>Tiam-1 expression is closely associated with the invasiveness and metastasis of NPC, indicating that Tiam-1 is an important factor that promotes the invasion and metastasis of NPC.</p>

Clinical and pathological analysis of 8 hereditary nonpolyposis colorectal cancer pedigrees / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the clinical and pathological features of patients with hereditary nonpolyposis colorectal cancer (HNPCC).</p><p><b>METHODS</b>The data of 8 HNPCC pedigrees according with Amsterdam standard II were collected and their pedigree trees were generated.</p><p><b>RESULTS</b>The morbidity of HNPCC was 1.59%. Thirty-one patients were found in the 8 HNPCC pedigrees including 25 with colorectal cancer and 6 with extraintestinal tumors. The 8 probands consisted of 6 female and 2 male patients, among whom 4 were younger than 40 years old, 2 had lesions in the right colon, 3 in the left colon, and 3 in the rectum. The tumors were histologically identified mainly as highly to moderately differentiated adenocarcinoma; all the patients were free of lymph node or distant metastasis. Of the 8 probands, 5 had abnormal expression of MMR protein and only 1 had normal expression.</p><p><b>CONCLUSION</b>The HNPCC probands are characterized by early onset at a young age and high differentiation of the tumor. The members of the pedigrees show a high incidence of the malignancies, and regular examination and timely treatment can be effective in preventing the tumor occurrence and reducing the mortality. Detection of MMR gene mutation can be a crucial approach to raising the diagnostic rate of HNPCC.</p>

To evaluate the neutralizing abilities of anti-dengue virus antibodies with nonstructural protein 1 antigen capture enzyme-linked immunosorbent assay / 中华预防医学杂志

<p><b>OBJECTIVE</b>To produce neutralizing antibodies against envelope protein domain III (EDIII) of dengue virus serotype I (DENV-1) and evaluate the nonstructural protein 1 (NS1) antigen capture enzyme-linked immunosorbent assay (ELISA) for identification of antibody neutralizing abilities.</p><p><b>METHODS</b>Five BALB/c mice and one New Zealand Rabbit were immunized with recombinant EDIII protein of DENV-1 for the production of hybridomas and hyperimmune sera. Indirect ELISA, immunofluorescence assay (IFA) and Western Blot analyses were applied to identify specificity of antibodies. Comparing to plaque reduction neutralization test (PRNT), the new established DENV-1 specific NS1 antigen capture ELISA was used for detecting the neutralizing abilities of these antibody.</p><p><b>RESULTS</b>Four strains of monoclonal antibodies (mAbs) named 1A1, 1B3, 3D3 and 9D6 and one hyperimmune serum of rabbit were obtained, all of which were approved to have neutralizing abilities to DENV-1 with the PRNT titer of 1:1024, 1:512, 1:256, 1:4096 and 1:4096. MAb 3D3 with the lowest neutralization titer in PRNT had not shown neutralizing ability to DENV-1 in NS1 antigen capture ELISA, while MAbs 1A1, 1B3 and 9D6 and the rabbit hyperimmune serum could protect the C6/36 from being infected by DENV-1 with the neutralization titer of 1:32, 1:32, 1:128 and 1:128 in this assay.</p><p><b>CONCLUSION</b>NS1 antigen capture ELISA could be used to identify antibody neutralizing abilities to DENV, it was a faster and more convenient way to screen antibodies with high neutralization titer and might also be used as one of the methods to evaluate the effects of vaccines.</p>

Overexpression of Tiam1 gene and its relationship with invasive and metastatic ability of nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore biological aspects of Tiam1 gene expression in nasopharyngeal carcinoma cells.</p><p><b>METHODS</b>Tiam1/C1199HA expression plasmids were transfected into nasopharyngeal carcinoma cells of C666-1 and CNE1 by lipofectamine2000. RT-PCR, real-time PCR and Western blot Analyses were performed to evaluate the expression of Tiam1 mRNA and protein levels, respectively. In vitro cell adhesion, wound healing and matrigel invasion assays were used to study the biological impact of Tiam1 on cell adhesion, mobility and invasion.</p><p><b>RESULTS</b>Tiam1 over expression significantly increased the abilities of adhesion, migratory and invasion of C666-1 and CNE1 cells, comparing with that of the control untransfected cells (P < 0.05).</p><p><b>CONCLUSION</b>Tiam1 expression correlates with the invasion and metastasis of nasopharyngeal carcinoma cells.</p>

Celecoxib enhances the lethal effects of bleomycin in human tongue squamous carcinoma cell line Tca8113 / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the role of COX-2 inhibitor celecoxib in enhancing the lethal effects of bleomycin in Tca8113 cell line.</p><p><b>METHODS</b>Tca8113 cells were treated with different concentrations of celecoxib and bleomycin for 24, 48, 72 h. Methyl thiazolyl tetrazolium assay was used to calculate cell growth inhibition rate and Jin Zheng Jun's method was used to evaluate the interaction of celecoxib and bleomycin on Tca8113 cells. Flow cytometry was used to evaluate the effects of combined use of celecoxib and bleomycin on cell cycle progress and apoptosis.</p><p><b>RESULTS</b>Low dose of celecoxib (10 micromol/L, < IC(50)) combined with bleomycin showed synergism or additive lethal effect on Tca8113 cell line. Celecoxib could notably enhance the inhibitory effect of bleomycin on Tca8113 cells by blocking cell cycle progress and thus resulting in the increasing G(0)/G(1) cells [(60.93 +/- 0.32)%] distribution and inducing apoptosis [(1.87 +/- 0.11)%].</p><p><b>CONCLUSIONS</b>Low doses of celecoxib could significantly enhance the lethal effect of bleomycin on Tca8113 cells by inhibiting cell growth and proliferation through blocking cell cycle progress and inducing apoptosis. The ways of these interactions on inhibiting Tca8113 cell growth were synergistic or/and additive.</p>

Construction of a lentiviral vector for RNA interference of human CDH22 gene and its gene silencing effect in SW480 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a lentiviral expression vector for RNA interference of human CDH22 gene, and assess its gene silencing effect in colorectal cancer cells to provide a basis for investigating the role of CDH22 gene in the signaling pathway involved in human colorectal carcinoma metastasis.</p><p><b>METHODS</b>Human CDH22 gene short hairpin RNA (shRNA) sequence was designed using a software available on-line. After synthesis and annealing, the double-stranded oligonucleotides (dsOligoe) were cloned into the pENTR(TM)/U6 plasmid followed by sequence analysis. A positive clone was subcloned into pLenti6/BLOCK-iT(TM)-DEST vector and transformed into stb13 competent cells, with also verification by sequencing. The recombinant lentivirus was harvested from 293FT cells contransfected with the positive recombined plasmid and lentiviral packing materials. SW480 cells were infected with the recombinant lentivirus and the cells with stable CDH22 knock-down were screened by blasticidin selection. CDH22 expression in the cells was determined by real-time reverse transcription-polymerase chain reaction.</p><p><b>RESULTS</b>A recombinant lentiviral vector expressing shRNAs against CDH22 gene was obtained and confirmed by DNA sequencing. Fifteen clones of SW480 cells infected with the recombinant lentivirus were selected, and clone 11 exhibited substantial knock-down of CDH22 mRNA expression.</p><p><b>CONCLUSION</b>The lentiviral shRNA expression vector targeting human CDH22 gene capable of stable CDH22 gene knock-down in SW480 cells has been successfully constructed, which provides a basis for further study of the relationship between human colorectal carcinoma and CDH22 gene.</p>