AIM:To investigate the inhibitory effects of RNA interference (RNAi) on expression of matrix metalloproteinase-2 (MMP-2) gene and invasiveness and adhesion of human pancreatic cancer cell line,BxPC-3.METHODS:RNAi was ...AIM:To investigate the inhibitory effects of RNA interference (RNAi) on expression of matrix metalloproteinase-2 (MMP-2) gene and invasiveness and adhesion of human pancreatic cancer cell line,BxPC-3.METHODS:RNAi was performed using the vector (pGPU6)-based small interference RNA (siRNA) plasmid gene silence system to specifically knock down MMP-2 expression in pancreatic cancer cell line,BxPC-3. Four groups of different specific target sequence in coding region of MMP-2 and one non-specific sequence were chosen to construct four experimental siRNA plasmids of pGPU6-1,pGPU6-2,pGPU6-3 and pGPU6-4,and one negative control siRNA plasmid of pGPU6 (-). MMP-2 expression was measured by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation and apoptosis were examined by methyl thiazolyl tetrazolium (MTT) and flow cytometry,respectively. The abilities of adhesion and invasion were detected by cell adhesion assay and cell invasion assay using Transwell chambers.RESULTS:The expression of MMP-2 was inhibited and the inhibitory effects of different sequence varied. pGPU6-1 group had the most efficient inhibitory effect,followed by pGPU6-2 and pGPU6-3 groups.Invasiveness and adhesion were more significantly reduced in pGPU6-1,pGPU6-2 and pGPU6-3 groups as compared with pGPU6 (-) and blank control groups. However,no difference concerning cell proliferation and apoptosis was observed after transfection between experiment groups and control groups.CONCLUSION:RNAi against MMP-2 successfully inhibited the mRNA and protein expression of MMP-2 in the pancreatic cancer cell line,BxPC-3,leading to a potent suppression of tumor cell adhesion and invasion without affecting cell proliferation and apoptosis. These findings suggest that the RNAi approach towards MMP-2 may be an effective therapeutic strategy for the clinical management of pancreatic tumor.展开更多
AIM: To investigate the effects of integrin-linked kinase (ILK) on gastric cancer cells both in vitro and in vivo. METHODS: ILK small interfering RNA (siRNA) was transfected into human gastric cancer BGC-823 cel...AIM: To investigate the effects of integrin-linked kinase (ILK) on gastric cancer cells both in vitro and in vivo. METHODS: ILK small interfering RNA (siRNA) was transfected into human gastric cancer BGC-823 cells and ILK expression was monitored by real-time quan- titative polymerase chain reaction, Western blotting analysis and immunocytochemistry. Cell attachment, proliferation, invasion, microfilament dynamics and the secretion of vascular endothelial growth factor (VEGF) were also measured. Gastric cancer cells treated with ILK siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed. RESULTS: Both ILK mRNA and protein levels were significantly down-regulated by ILK siRNA in human gastric cancer cells. This significantly inhibited cell attachment, proliferation and invasion. The knockdown of ILK also disturbed F-actin assembly and reduced VEGF secretion in conditioned medium by 40% (P 〈 0.05). Four weeks after injection of ILK siRNA-transfected gastric cancer cells into nude mice, tumor volume and weight were significantly reduced compared with that of tumors induced by cells treated with non-silencing siRNA or by untreated cells (P 〈 0.05). CONCLUSION: Targeting ILK with siRNA suppresses the growth of gastric cancer cells both in v/tro and /n vivo. ILK plays an important role in gastric cancer progression.展开更多
AIM: To investigate the influence of CO2-insufflation pressure on adhesion, invasion and metastatic potential of colon cancer cells based on adhesion molecules expression. METHODS: With an/n vitro artificial pneumop...AIM: To investigate the influence of CO2-insufflation pressure on adhesion, invasion and metastatic potential of colon cancer cells based on adhesion molecules expression. METHODS: With an/n vitro artificial pneumoperitoneum model, SW1116 human colon carcinoma cells were exposed to CO2-insufflation in 5 different pressure groups: 6 mmHg, 9 mmHg, 12 mmHg, 15 mmHg and control group, respectively for 1 h. Expression of E-cadherin, ICAM-I, CD44 and E-selectin was meas- ured at 0, 12, 24, 48 and 72 h after CO2-insufflation using flow cytometry. The adhesion and invasion capacity of SW1116 cells before and after exposure to CO2-insufflation was detected by cell adhesion/invasion assay in vitro. Each group of cells was injected intraperitoneally into 16 BALB/C mice. The number of visible abdominal cavity tumor nodules, visceral metas-tases and survival of the mice were recorded in each group. RESULTS: The expression of E-cadherin, ICAM-1, CD44 and E-selectin in SWl116 cells were changed significantly following exposure to CO2 insufflation at different pressures (P 〈 0.05). The expression of E-cadherin, CD44 and ICAM-1 decreased with increasing CO2-insufflation pressure. The adhesive/ invasive cells also decreased gradually with increasing pressure as determined by the adhesion/invasion assay. In animal experiments, the number of abdominal cavity tumor nodules in the 15 mmHg group was also significantly lower than that in the 6 mmHg group (29.7± 9.91 vs 41.7±14.90, P = 0.046). However, the survival in each group was not statistically different. CONCLUSION: CO2-insufflation induced a temporary change in the adhesion and invasion capacity of cancer cells in vitro. Higher CO2-insufflation pressure inhibited adhesion, invasion and metastatic potential in vitro and in vivo, which was associated with reduced expression of adhesion molecules.展开更多
A case of intraductal papillary neoplasm of the bile duct (IPNB) arising in a patient with hepatitis B-related liver cirrhosis with hepatocellular carcinoma (HCC) is reported. A 76-year-old man was admitted to our hos...A case of intraductal papillary neoplasm of the bile duct (IPNB) arising in a patient with hepatitis B-related liver cirrhosis with hepatocellular carcinoma (HCC) is reported. A 76-year-old man was admitted to our hospital with recurrent HCC. Laboratory data showed that levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were elevated. He died of progressive hepatic failure. At autopsy,in addition to HCCs,an intraductal papillary proliferation of malignant cholangiocytes with fibrovascular cores was found in the dilated large bile ducts in the left lobe,and this papillary carcinoma was associated with an invasive mucinous carcinoma (invasive IPNB). Interestingly,extensive intraductal spread of the cholangiocarcinoma was found from the reactive bile ductular level to the interlobular bile ducts and septal bile ducts and to the large bile ducts in the left lobe. Neural cell adhesion molecule,a hepatic progenitor cell marker,was detected in IPNB cells. It seems possible in this case that hepatic progenitor cells located in reactive bile ductules in liver cirrhosis may have been responsible for the development of the cholangiocarcinoma and HCC,and that the former could have spread in the intrahepatic bile ducts and eventually formed grossly visible IPNB.展开更多
AIM: To investigate the relationship between Interleu- kin-8 (IL-8) and proliferation, adhesion, migration, inva- sion and chemosensitivity of gastric cancer (GC) cells.
AIM:To investigate the association between single nu-cleotide polymorphisms (SNPs) in intercellular adhesion molecule-1 (ICAM-1) and the risk,biological behavior and prognosis of gastric cancer (GC) in Chinese populat...AIM:To investigate the association between single nu-cleotide polymorphisms (SNPs) in intercellular adhesion molecule-1 (ICAM-1) and the risk,biological behavior and prognosis of gastric cancer (GC) in Chinese population.METHODS:The study group consisted of 332 GC patients and 380 healthy controls.Genotyping was performed using polymerase chain reaction and the results were confirmed by sequencing.The associa-tion of ICAM-1 K469E polymorphisms and the risk of GC were studied,and the correlation of ICAM-1 K469E polymorphisms with the clinicopathological parameters and prognosis of the patients with complete clinical and follow-up data was analyzed.RESULTS:Carriers of AA genotype had a significantly increased risk of GC compared with carriers of AG and GG genotypes [odds ratios:1.36;95% confidence in-terval (CI):1.01-1.84;P=0.041].GC patients with AA genotype were more prone to distant metastasis than those carrying AG and GG genotypes (18.9% vs 7.0%,respectively;P=0.002).In addition,patients at stage Ⅳ had significantly more carriers of AA genotype than those of AG and GG genotype (27.4% vs 16.9%,re-spectively;P=0.046).Follow-up study showed that the overall cumulative survival rate was 23.7% in AA geno-type group and 42.9% in AG and GG genotypes group.In univariate analysis,AA genotype was correlated with the overall cumulative survival (P=0.034).But in multi-variate analysis,ICAM-1 polymorphism was not an inde-pendent prognostic factor for the overall survival (relative risk,1.145;95% CI:0.851-1.540;P=0.370).CONCLUSION:Polymorphisms of ICAM-1 K469E can be a useful biomarker for identifying individuals with higher risk of GC,predicting disease progression,and guiding individualized treatment.展开更多
AIM: To analyse αv integrin expression induced by gas- trin in pancreatic cancer models.METHODS: αv integrin mRNA expression in human pan- creatic cancer cells was analysed using a "cancer genes" array and confi...AIM: To analyse αv integrin expression induced by gas- trin in pancreatic cancer models.METHODS: αv integrin mRNA expression in human pan- creatic cancer cells was analysed using a "cancer genes" array and confirmed by real-time reverse transcription- polymerase chain reaction (PCR). Western blotting and semi-quantitative immunohistochemistry were used to examine protein levels in human pancreatic cancer cell lines and pancreatic tissues, respectively, The role of αv integrin on gastrin-induced cell adhesion was examined using blocking anti-αv integrin monoclonal antibodies. Adherent cells were quantified by staining with crystal violet.RESULTS: Using a "cancer genes" array we identi- fied c^v integrin as a new gastrin target gene in human pancreatic cancer cells. A quantitative real-time PCR approach was used to confirm αv integrin gene expression. We also demonstrate that Src family kinases and the PI 3-kinase, two signalling pathways specifically activated by the CCK-2 receptor (CCK2R), are involved in gastrin-mediated αv integrin expression. In contrast, inhibition of the ERK pathway was without any effect on αv integrin expression induced by gastrin. Our results also show that gastrin modulates cell adhesion via αv integrins. Indeed, in vitro adhesion assays performed on fibronectin show that gastrin significantly increases adhesion of pancreatic cancer cells. The use of blocking anti-αv integrin monoclonal antibodies completely reversed the increase in cell-substrate adhesion induced by gastrin. In addition, we showed in vivo that the targeted CCK2R expression in the pancreas of Elas-CCK2 mice, leads to the overexpression of αv integrin. This process may contribute to pancreatic turnout development observed in these transgenic animals.CONCLUSION: αv integrin is a new gastrin target in pancreatic cancer models and contributes to gastrin effects on cell adhesion.展开更多
To determine the role of corticotropin releasing factor receptor (CRF2) in epithelial permeability and enterocyte cell differentiation.METHODSFor this purpose, we used rat Sprague Dawley and various colon carcinoma ce...To determine the role of corticotropin releasing factor receptor (CRF2) in epithelial permeability and enterocyte cell differentiation.METHODSFor this purpose, we used rat Sprague Dawley and various colon carcinoma cell lines (SW620, HCT8R, HT-29 and Caco-2 cell lines). Expression of CRF2 protein was analyzed by fluorescent immunolabeling in normal rat colon and then by western blot in dissociated colonic epithelial cells and in the lysates of colon carcinoma cell lines or during the early differentiation of HT-29 cells (ten first days). To assess the impact of CRF2 signaling on colonic cell differentiation, HT-29 and Caco-2 cells were exposed to Urocortin 3 recombinant proteins (Ucn3, 100 nmol/L). In some experiments, cells were pre-exposed to the astressin 2b (A2b) a CRF2 antagonist in order to inhibit the action of Ucn3. Intestinal cell differentiation was first analyzed by functional assays: the trans-cellular permeability and the para-cellular permeability were determined by Dextran-FITC intake and measure of the transepithelial electrical resistance respectively. Morphological modifications associated to epithelial dysfunction were analyzed by confocal microscopy after fluorescent labeling of actin (phaloidin-TRITC) and intercellular adhesion proteins such as E-cadherin, p120ctn, occludin and ZO-1. The establishment of mature adherens junctions (AJ) was monitored by following the distribution of AJ proteins in lipid raft fractions, after separation of cell lysates on sucrose gradients. Finally, the mRNA and the protein expression levels of characteristic markers of intestinal epithelial cell (IEC) differentiation such as the transcriptional factor krüppel-like factor 4 (KLF4) or the dipeptidyl peptidase IV (DPPIV) were performed by RT-PCR and western blot respectively. The specific activities of DPPIV and alkaline phosphatase (AP) enzymes were determined by a colorimetric method.RESULTSCRF2 protein is preferentially expressed in undifferentiated epithelial cells from the crypts of colon and in human colon carcinoma cell lines. Furthermore, CRF2 expression is down regulated according to the kinetic of HT-29 cell differentiation. By performing functional assays, we found that Ucn3-induced CRF2 signaling alters both para- and trans-cellular permeability of differentiated HT-29 and Caco-2 cells. These effects are partly mediated by Ucn3-induced morphological changes associated with the disruption of mature AJ in HT-29 cells and tight junctions (TJ) in Caco-2 cells. Ucn3-mediated activation of CRF2 decreases mRNA and protein expression levels of KLF4 a transcription factor involved in IEC differentiation. This signaling is correlated to a down-regulation of key IEC markers such as DPPIV and AP, at both transcriptional and post-transcriptional levels.CONCLUSIONOur findings suggest that CRF2 signaling could modulate IEC differentiation. These mechanisms could be relevant to the stress induced epithelial alterations found in inflammatory bowel diseases.展开更多
基金Supported by Tiantan Hospital Scientific Project Grant Fund
文摘AIM:To investigate the inhibitory effects of RNA interference (RNAi) on expression of matrix metalloproteinase-2 (MMP-2) gene and invasiveness and adhesion of human pancreatic cancer cell line,BxPC-3.METHODS:RNAi was performed using the vector (pGPU6)-based small interference RNA (siRNA) plasmid gene silence system to specifically knock down MMP-2 expression in pancreatic cancer cell line,BxPC-3. Four groups of different specific target sequence in coding region of MMP-2 and one non-specific sequence were chosen to construct four experimental siRNA plasmids of pGPU6-1,pGPU6-2,pGPU6-3 and pGPU6-4,and one negative control siRNA plasmid of pGPU6 (-). MMP-2 expression was measured by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation and apoptosis were examined by methyl thiazolyl tetrazolium (MTT) and flow cytometry,respectively. The abilities of adhesion and invasion were detected by cell adhesion assay and cell invasion assay using Transwell chambers.RESULTS:The expression of MMP-2 was inhibited and the inhibitory effects of different sequence varied. pGPU6-1 group had the most efficient inhibitory effect,followed by pGPU6-2 and pGPU6-3 groups.Invasiveness and adhesion were more significantly reduced in pGPU6-1,pGPU6-2 and pGPU6-3 groups as compared with pGPU6 (-) and blank control groups. However,no difference concerning cell proliferation and apoptosis was observed after transfection between experiment groups and control groups.CONCLUSION:RNAi against MMP-2 successfully inhibited the mRNA and protein expression of MMP-2 in the pancreatic cancer cell line,BxPC-3,leading to a potent suppression of tumor cell adhesion and invasion without affecting cell proliferation and apoptosis. These findings suggest that the RNAi approach towards MMP-2 may be an effective therapeutic strategy for the clinical management of pancreatic tumor.
基金Supported by The grants from the Department of Anesthesiology and Intensive Care of Changhai Hospital,Shanghai,China
文摘AIM: To investigate the effects of integrin-linked kinase (ILK) on gastric cancer cells both in vitro and in vivo. METHODS: ILK small interfering RNA (siRNA) was transfected into human gastric cancer BGC-823 cells and ILK expression was monitored by real-time quan- titative polymerase chain reaction, Western blotting analysis and immunocytochemistry. Cell attachment, proliferation, invasion, microfilament dynamics and the secretion of vascular endothelial growth factor (VEGF) were also measured. Gastric cancer cells treated with ILK siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed. RESULTS: Both ILK mRNA and protein levels were significantly down-regulated by ILK siRNA in human gastric cancer cells. This significantly inhibited cell attachment, proliferation and invasion. The knockdown of ILK also disturbed F-actin assembly and reduced VEGF secretion in conditioned medium by 40% (P 〈 0.05). Four weeks after injection of ILK siRNA-transfected gastric cancer cells into nude mice, tumor volume and weight were significantly reduced compared with that of tumors induced by cells treated with non-silencing siRNA or by untreated cells (P 〈 0.05). CONCLUSION: Targeting ILK with siRNA suppresses the growth of gastric cancer cells both in v/tro and /n vivo. ILK plays an important role in gastric cancer progression.
文摘AIM: To investigate the influence of CO2-insufflation pressure on adhesion, invasion and metastatic potential of colon cancer cells based on adhesion molecules expression. METHODS: With an/n vitro artificial pneumoperitoneum model, SW1116 human colon carcinoma cells were exposed to CO2-insufflation in 5 different pressure groups: 6 mmHg, 9 mmHg, 12 mmHg, 15 mmHg and control group, respectively for 1 h. Expression of E-cadherin, ICAM-I, CD44 and E-selectin was meas- ured at 0, 12, 24, 48 and 72 h after CO2-insufflation using flow cytometry. The adhesion and invasion capacity of SW1116 cells before and after exposure to CO2-insufflation was detected by cell adhesion/invasion assay in vitro. Each group of cells was injected intraperitoneally into 16 BALB/C mice. The number of visible abdominal cavity tumor nodules, visceral metas-tases and survival of the mice were recorded in each group. RESULTS: The expression of E-cadherin, ICAM-1, CD44 and E-selectin in SWl116 cells were changed significantly following exposure to CO2 insufflation at different pressures (P 〈 0.05). The expression of E-cadherin, CD44 and ICAM-1 decreased with increasing CO2-insufflation pressure. The adhesive/ invasive cells also decreased gradually with increasing pressure as determined by the adhesion/invasion assay. In animal experiments, the number of abdominal cavity tumor nodules in the 15 mmHg group was also significantly lower than that in the 6 mmHg group (29.7± 9.91 vs 41.7±14.90, P = 0.046). However, the survival in each group was not statistically different. CONCLUSION: CO2-insufflation induced a temporary change in the adhesion and invasion capacity of cancer cells in vitro. Higher CO2-insufflation pressure inhibited adhesion, invasion and metastatic potential in vitro and in vivo, which was associated with reduced expression of adhesion molecules.
文摘A case of intraductal papillary neoplasm of the bile duct (IPNB) arising in a patient with hepatitis B-related liver cirrhosis with hepatocellular carcinoma (HCC) is reported. A 76-year-old man was admitted to our hospital with recurrent HCC. Laboratory data showed that levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were elevated. He died of progressive hepatic failure. At autopsy,in addition to HCCs,an intraductal papillary proliferation of malignant cholangiocytes with fibrovascular cores was found in the dilated large bile ducts in the left lobe,and this papillary carcinoma was associated with an invasive mucinous carcinoma (invasive IPNB). Interestingly,extensive intraductal spread of the cholangiocarcinoma was found from the reactive bile ductular level to the interlobular bile ducts and septal bile ducts and to the large bile ducts in the left lobe. Neural cell adhesion molecule,a hepatic progenitor cell marker,was detected in IPNB cells. It seems possible in this case that hepatic progenitor cells located in reactive bile ductules in liver cirrhosis may have been responsible for the development of the cholangiocarcinoma and HCC,and that the former could have spread in the intrahepatic bile ducts and eventually formed grossly visible IPNB.
基金Supported by The Fund of Nanjing Medical University Science and Technology Development,No.09NJMUZ30
文摘AIM: To investigate the relationship between Interleu- kin-8 (IL-8) and proliferation, adhesion, migration, inva- sion and chemosensitivity of gastric cancer (GC) cells.
基金Supported by Grants from Beijing Municipal Science and Technology Commission NOVA Program,No.2009BG-02the National High Technology Research and Development Program of China,No.2006AA02A402the Major State Basic Research Program of China,No.2004CB518702
文摘AIM:To investigate the association between single nu-cleotide polymorphisms (SNPs) in intercellular adhesion molecule-1 (ICAM-1) and the risk,biological behavior and prognosis of gastric cancer (GC) in Chinese population.METHODS:The study group consisted of 332 GC patients and 380 healthy controls.Genotyping was performed using polymerase chain reaction and the results were confirmed by sequencing.The associa-tion of ICAM-1 K469E polymorphisms and the risk of GC were studied,and the correlation of ICAM-1 K469E polymorphisms with the clinicopathological parameters and prognosis of the patients with complete clinical and follow-up data was analyzed.RESULTS:Carriers of AA genotype had a significantly increased risk of GC compared with carriers of AG and GG genotypes [odds ratios:1.36;95% confidence in-terval (CI):1.01-1.84;P=0.041].GC patients with AA genotype were more prone to distant metastasis than those carrying AG and GG genotypes (18.9% vs 7.0%,respectively;P=0.002).In addition,patients at stage Ⅳ had significantly more carriers of AA genotype than those of AG and GG genotype (27.4% vs 16.9%,re-spectively;P=0.046).Follow-up study showed that the overall cumulative survival rate was 23.7% in AA geno-type group and 42.9% in AG and GG genotypes group.In univariate analysis,AA genotype was correlated with the overall cumulative survival (P=0.034).But in multi-variate analysis,ICAM-1 polymorphism was not an inde-pendent prognostic factor for the overall survival (relative risk,1.145;95% CI:0.851-1.540;P=0.370).CONCLUSION:Polymorphisms of ICAM-1 K469E can be a useful biomarker for identifying individuals with higher risk of GC,predicting disease progression,and guiding individualized treatment.
文摘AIM: To analyse αv integrin expression induced by gas- trin in pancreatic cancer models.METHODS: αv integrin mRNA expression in human pan- creatic cancer cells was analysed using a "cancer genes" array and confirmed by real-time reverse transcription- polymerase chain reaction (PCR). Western blotting and semi-quantitative immunohistochemistry were used to examine protein levels in human pancreatic cancer cell lines and pancreatic tissues, respectively, The role of αv integrin on gastrin-induced cell adhesion was examined using blocking anti-αv integrin monoclonal antibodies. Adherent cells were quantified by staining with crystal violet.RESULTS: Using a "cancer genes" array we identi- fied c^v integrin as a new gastrin target gene in human pancreatic cancer cells. A quantitative real-time PCR approach was used to confirm αv integrin gene expression. We also demonstrate that Src family kinases and the PI 3-kinase, two signalling pathways specifically activated by the CCK-2 receptor (CCK2R), are involved in gastrin-mediated αv integrin expression. In contrast, inhibition of the ERK pathway was without any effect on αv integrin expression induced by gastrin. Our results also show that gastrin modulates cell adhesion via αv integrins. Indeed, in vitro adhesion assays performed on fibronectin show that gastrin significantly increases adhesion of pancreatic cancer cells. The use of blocking anti-αv integrin monoclonal antibodies completely reversed the increase in cell-substrate adhesion induced by gastrin. In addition, we showed in vivo that the targeted CCK2R expression in the pancreas of Elas-CCK2 mice, leads to the overexpression of αv integrin. This process may contribute to pancreatic turnout development observed in these transgenic animals.CONCLUSION: αv integrin is a new gastrin target in pancreatic cancer models and contributes to gastrin effects on cell adhesion.
基金Supported by grants from Association pour la Recherche sur le Cancer,Ligue Nationale contre le Cancer,No.GEFLUC and No.ESPOIR
文摘To determine the role of corticotropin releasing factor receptor (CRF2) in epithelial permeability and enterocyte cell differentiation.METHODSFor this purpose, we used rat Sprague Dawley and various colon carcinoma cell lines (SW620, HCT8R, HT-29 and Caco-2 cell lines). Expression of CRF2 protein was analyzed by fluorescent immunolabeling in normal rat colon and then by western blot in dissociated colonic epithelial cells and in the lysates of colon carcinoma cell lines or during the early differentiation of HT-29 cells (ten first days). To assess the impact of CRF2 signaling on colonic cell differentiation, HT-29 and Caco-2 cells were exposed to Urocortin 3 recombinant proteins (Ucn3, 100 nmol/L). In some experiments, cells were pre-exposed to the astressin 2b (A2b) a CRF2 antagonist in order to inhibit the action of Ucn3. Intestinal cell differentiation was first analyzed by functional assays: the trans-cellular permeability and the para-cellular permeability were determined by Dextran-FITC intake and measure of the transepithelial electrical resistance respectively. Morphological modifications associated to epithelial dysfunction were analyzed by confocal microscopy after fluorescent labeling of actin (phaloidin-TRITC) and intercellular adhesion proteins such as E-cadherin, p120ctn, occludin and ZO-1. The establishment of mature adherens junctions (AJ) was monitored by following the distribution of AJ proteins in lipid raft fractions, after separation of cell lysates on sucrose gradients. Finally, the mRNA and the protein expression levels of characteristic markers of intestinal epithelial cell (IEC) differentiation such as the transcriptional factor krüppel-like factor 4 (KLF4) or the dipeptidyl peptidase IV (DPPIV) were performed by RT-PCR and western blot respectively. The specific activities of DPPIV and alkaline phosphatase (AP) enzymes were determined by a colorimetric method.RESULTSCRF2 protein is preferentially expressed in undifferentiated epithelial cells from the crypts of colon and in human colon carcinoma cell lines. Furthermore, CRF2 expression is down regulated according to the kinetic of HT-29 cell differentiation. By performing functional assays, we found that Ucn3-induced CRF2 signaling alters both para- and trans-cellular permeability of differentiated HT-29 and Caco-2 cells. These effects are partly mediated by Ucn3-induced morphological changes associated with the disruption of mature AJ in HT-29 cells and tight junctions (TJ) in Caco-2 cells. Ucn3-mediated activation of CRF2 decreases mRNA and protein expression levels of KLF4 a transcription factor involved in IEC differentiation. This signaling is correlated to a down-regulation of key IEC markers such as DPPIV and AP, at both transcriptional and post-transcriptional levels.CONCLUSIONOur findings suggest that CRF2 signaling could modulate IEC differentiation. These mechanisms could be relevant to the stress induced epithelial alterations found in inflammatory bowel diseases.