BACKGROUND Claudin 7 is often abnormally expressed in cancers and promotes the progression of some malignancies. However, the role of claudin 7 in stage Ⅱ colorectal cancer(CRC) has not been studied.AIM To assess the...BACKGROUND Claudin 7 is often abnormally expressed in cancers and promotes the progression of some malignancies. However, the role of claudin 7 in stage Ⅱ colorectal cancer(CRC) has not been studied.AIM To assess the expression and prognostic value of claudin 7 in stage Ⅱ CRC.METHODS We retrospectively studied 231 stage Ⅱ CRC patients who underwent radical surgery at our hospital from 2013 to 2014. The protein expression level of claudin7 was assessed and its relationship with clinicopathological features and prognosis was statistically analyzed. The independent prognostic factors were identified by Cox proportional hazards models. A prognostic grading system was constructed to stratify the survival of CRC patients.RESULTS The expression of claudin 7 was significantly reduced in cancer tissues compared with normal tissues(P < 0.001), and its low expression was closely related to recurrence of the disease(P = 0.017). Multivariate analysis confirmed that claudin7 low expression(claudin 7-low)(P = 0.028) and perineural invasion positivity(PNI+)(P = 0.026) were independent predictors of poor disease-free survival(DFS). A prognostic grading system based on the status of claudin 7 and PNI classified the patients into three prognostic grades: grade A(claudin 7-high and PNI-), grade B(claudin 7-low and PNI-, claudin 7-high and PNI+), and grade C(claudin 7-low and PNI+). The DFS was significantly different among the three grades(grade B vs grade A, P = 0.032;grade C vs grade A, P < 0.001;grade C vs grade B, P = 0.040).CONCLUSION Claudin 7 can be used as a new prognostic marker to predict the DFS of patients with stage Ⅱ CRC. The prognostic grading system with the addition of claudin 7 can further improve prognosis stratification of patients.展开更多
BACKGROUND Claudin-7, one of the important components of cellular tight junctions, is currently considered to be expressed abnormally in colorectal inflammation and colorectal cancer. However, there is currently no ef...BACKGROUND Claudin-7, one of the important components of cellular tight junctions, is currently considered to be expressed abnormally in colorectal inflammation and colorectal cancer. However, there is currently no effective animal model to study its specific mechanism. Therefore, we constructed three lines of Claudin-7 knockout mice using the Cre/LoxP system.AIM To determine the function of the tumor suppressor gene Claudin-7 by generating three lines of Claudin-7 gene knockout mice.METHODS We crossed Claudin-7-floxed mice with CMV-Cre, vil1-Cre, and villin-CreERT2 transgenic mice, and the offspring were self-crossed to obtain conventional Claudin-7 knockout mice, conditional(intestinal specific) Claudin-7 knockout mice, and inducible conditional Claudin-7 knockout mice. Intraperitoneal injection of tamoxifen into the inducible conditional Claudin-7 knockout mice can induce the knockout of Claudin-7. PCR and agarose gel electrophoresis were used to identify mouse genotypes, and Western blot was used to confirm the knockout of Claudin-7. The mental state, body length, and survival time of these mice were observed. The dying mice were sacrificed, and hematoxylin-eosin(HE) staining and immunohistochemical staining were performed to observe changes in intestinal structure and proliferation markers.RESULTS We generated Claudin-7-floxed mice and three lines of Claudin-7 gene knockout mice using the Cre/LoxP system successfully. Conventional and intestinal specific Claudin-7 knockout mice were stunted and died during the perinatal period, and intestinal HE staining in these mice revealed mucosal gland structure disappearance and connective tissue hyperplasia with extensive inflammatory cell infiltration. The inducible conditional Claudin-7 knockout mice had a normal phenotype at birth, but after the induction with tamoxifen, they exhibited a dying state. Intestinal HE staining showed significant inflammatory cell infiltration, and atypical hyperplasia and adenoma were also observed. Intestinal immunohistochemistry analysis showed abnormal expression and distribution of Ki67, and the normal intestinal proliferation balance was disrupted. The intestinal crypt size in inducible conditional Claudin-7 knockout mice was increased compared with control mice(small intestine: 54.1 ± 2.96 vs 38.4 ± 1.63;large intestine: 44.7 ± 1.93 vs 27.4 ± 0.60; P < 0.001).CONCLUSION The knockout of Claudin-7 in vivo causes extensive inflammation, atypical hyperplasia, and adenoma in intestinal tissue as well as animal death in mice.Claudin-7 may act as a tumor suppressor gene in the development of colorectal cancer.展开更多
基金Supported by the Beijing Science and Technology Program,No.D171100002617004.
文摘BACKGROUND Claudin 7 is often abnormally expressed in cancers and promotes the progression of some malignancies. However, the role of claudin 7 in stage Ⅱ colorectal cancer(CRC) has not been studied.AIM To assess the expression and prognostic value of claudin 7 in stage Ⅱ CRC.METHODS We retrospectively studied 231 stage Ⅱ CRC patients who underwent radical surgery at our hospital from 2013 to 2014. The protein expression level of claudin7 was assessed and its relationship with clinicopathological features and prognosis was statistically analyzed. The independent prognostic factors were identified by Cox proportional hazards models. A prognostic grading system was constructed to stratify the survival of CRC patients.RESULTS The expression of claudin 7 was significantly reduced in cancer tissues compared with normal tissues(P < 0.001), and its low expression was closely related to recurrence of the disease(P = 0.017). Multivariate analysis confirmed that claudin7 low expression(claudin 7-low)(P = 0.028) and perineural invasion positivity(PNI+)(P = 0.026) were independent predictors of poor disease-free survival(DFS). A prognostic grading system based on the status of claudin 7 and PNI classified the patients into three prognostic grades: grade A(claudin 7-high and PNI-), grade B(claudin 7-low and PNI-, claudin 7-high and PNI+), and grade C(claudin 7-low and PNI+). The DFS was significantly different among the three grades(grade B vs grade A, P = 0.032;grade C vs grade A, P < 0.001;grade C vs grade B, P = 0.040).CONCLUSION Claudin 7 can be used as a new prognostic marker to predict the DFS of patients with stage Ⅱ CRC. The prognostic grading system with the addition of claudin 7 can further improve prognosis stratification of patients.
基金the National Natural Science Foundation of China,No.81372585 and No.81772557Beijing Health System High Level Training Plan of Health Technical Personnel,No.2014-3-048
文摘BACKGROUND Claudin-7, one of the important components of cellular tight junctions, is currently considered to be expressed abnormally in colorectal inflammation and colorectal cancer. However, there is currently no effective animal model to study its specific mechanism. Therefore, we constructed three lines of Claudin-7 knockout mice using the Cre/LoxP system.AIM To determine the function of the tumor suppressor gene Claudin-7 by generating three lines of Claudin-7 gene knockout mice.METHODS We crossed Claudin-7-floxed mice with CMV-Cre, vil1-Cre, and villin-CreERT2 transgenic mice, and the offspring were self-crossed to obtain conventional Claudin-7 knockout mice, conditional(intestinal specific) Claudin-7 knockout mice, and inducible conditional Claudin-7 knockout mice. Intraperitoneal injection of tamoxifen into the inducible conditional Claudin-7 knockout mice can induce the knockout of Claudin-7. PCR and agarose gel electrophoresis were used to identify mouse genotypes, and Western blot was used to confirm the knockout of Claudin-7. The mental state, body length, and survival time of these mice were observed. The dying mice were sacrificed, and hematoxylin-eosin(HE) staining and immunohistochemical staining were performed to observe changes in intestinal structure and proliferation markers.RESULTS We generated Claudin-7-floxed mice and three lines of Claudin-7 gene knockout mice using the Cre/LoxP system successfully. Conventional and intestinal specific Claudin-7 knockout mice were stunted and died during the perinatal period, and intestinal HE staining in these mice revealed mucosal gland structure disappearance and connective tissue hyperplasia with extensive inflammatory cell infiltration. The inducible conditional Claudin-7 knockout mice had a normal phenotype at birth, but after the induction with tamoxifen, they exhibited a dying state. Intestinal HE staining showed significant inflammatory cell infiltration, and atypical hyperplasia and adenoma were also observed. Intestinal immunohistochemistry analysis showed abnormal expression and distribution of Ki67, and the normal intestinal proliferation balance was disrupted. The intestinal crypt size in inducible conditional Claudin-7 knockout mice was increased compared with control mice(small intestine: 54.1 ± 2.96 vs 38.4 ± 1.63;large intestine: 44.7 ± 1.93 vs 27.4 ± 0.60; P < 0.001).CONCLUSION The knockout of Claudin-7 in vivo causes extensive inflammation, atypical hyperplasia, and adenoma in intestinal tissue as well as animal death in mice.Claudin-7 may act as a tumor suppressor gene in the development of colorectal cancer.
