1500

CTNND1

catenin (cadherin-associated protein), delta 1;CTNND1;catenin (cadherin-associated protein), delta 1

cadherin-associated Src substrate|catenin delta-1|p120 catenin

11q11

protein-coding

PURPOSE: Presence of pelvic lymph node metastases is the main prognostic factor in early-stage cervical cancer patients, primarily treated with surgery. Aim of this study was to identify cellular tumor pathways associated with pelvic lymph node metastasis in early-stage cervical cancer. EXPERIMENTAL DESIGN: Gene expression profiles (Affymetrix U133 plus 2.0) of 20 patients with negative (N(0)) and 19 with positive lymph nodes (N(+)), were compared with gene sets that represent all 285 presently available pathway signatures. Validation immunostaining of tumors of 274 consecutive early-stage cervical cancer patients was performed for representatives of the identified pathways. RESULTS: Analysis of 285 pathways resulted in identification of five pathways (TGF-beta, NFAT, ALK, BAD, and PAR1) that were dysregulated in the N(0), and two pathways (beta-catenin and Glycosphingolipid Biosynthesis Neo Lactoseries) in the N(+) group. Class comparison analysis revealed that five of 149 genes that were most significantly differentially expressed between N(0) and N(+) tumors (P < 0.001) were involved in beta-catenin signaling (TCF4, CTNNAL1, CTNND1/p120, DKK3, and WNT5a). Immunohistochemical validation of two well-known cellular tumor pathways (TGF-beta and beta-catenin) confirmed that the TGF-beta pathway (positivity of Smad4) was related to N(0) (OR: 0.20, 95% CI: 0.06-0.66) and the beta-catenin pathway (p120 positivity) to N(+) (OR: 1.79, 95%CI: 1.05-3.05). CONCLUSIONS: Our study provides new, validated insights in the molecular mechanism of lymph node metastasis in cervical cancer. pathway analysis of the microarray expression profile suggested that the TGF-beta and p120-associated noncanonical beta-catenin pathways are important in pelvic lymph node metastasis in early-stage cervical cancer.

delta-Catenin is the only member of the p120 catenin (p120ctn) subfamily whose normal pattern of expression is restricted to the brain. Similar to p120ctn, delta-catenin can bind to the juxtamembrane domain of E-cadherin. We examined the expression of delta-catenin, p120ctn, and E-cadherin using immunohistochemistry in 95 cases of colorectal cancer (CRC) and 15 normal colon tissues. Co-immunoprecipitation was used to examine whether delta-catenin competed with p120ctn to bind E-cadherin in CRC cells. The effects of delta-catenin overexpression or siRNA-mediated knockdown on the proliferation and invasive ability of CRC cells were investigated using the MTT and Matrigel invasion assays. The results showed that positive delta-catenin expression was significantly more frequent in CRC compared to normal colon tissues and associated with poor differentiation, stage III-IV disease, and lymph node metastasis in CRC (all P < 0.05). In two CRC cell lines, delta-catenin bound to E-cadherin in competition with p120ctn. Overexpression of delta-catenin promoted the proliferation and invasion of CRC cells; knockdown of delta-catenin reduced CRC cell proliferation and invasion. In conclusion, we speculate that overexpression of delta-catenin reduces the expression of E-cadherin and alters the balance between E-cadherin and p120ctn, which in turn affects the formation of intercellular adhesions and promotes invasion and metastasis in CRC.

metastatic breast cancer is the major cause of cancer-related death among women in the Western world. Invasive carcinoma cells are able to counteract apoptotic signals in the absence of anchorage, enabling cell survival during invasion and dissemination. Although loss of E-cadherin is a cardinal event in the development and progression of invasive lobular carcinoma (ILC), little is known about the underlying mechanisms that govern these processes. Using a mouse model of human ILC, we show here that cytosolic p120-catenin (p120) regulates tumor growth upon loss of E-cadherin through the induction of anoikis resistance. p120 conferred anchorage independence by indirect activation of Rho/Rock signaling through interaction and inhibition of myosin phosphatase Rho-interacting protein (Mrip), an antagonist of Rho/Rock function. Consistent with these data, primary human ILC samples expressed hallmarks of active Rock signaling, and Rock controlled the anoikis resistance of human ILC cells. Thus, we have linked loss of E-cadherin - an initiating event in ILC development - to Rho/Rock-mediated control of anchorage-independent survival. Because activation of Rho and Rock are strongly linked to cancer progression and are susceptible to pharmacological inhibition, these insights may have clinical implications for the development of tailor-made intervention strategies to better treat invasive and metastatic lobular breast cancer.

p120-catenin, a member of the Armadillo gene family, has emerged as both a master regulator of cadherin stability and an important modulator of small GTPase activities. Therefore, it plays novel roles in tumor malignant phenotype, such as invasion and metastasis. We have reported previously that abnormal expression of p120-catenin is associated with lymph node metastasis in lung squamous cell carcinomas (SCC) and adenocarcinomas. To investigate the role and possible mechanism of p120-catenin in lung cancer, we knocked down p120-catenin using small interfering RNA (siRNA). We found that ablation of p120-catenin reduced the levels of E-cadherin and beta-catenin proteins, as well as the mRNA of beta-catenin. Furthermore, p120-catenin depletion inactivated RhoA, but increased the activity of Cdc42 and Rac1, and promoted proliferation and the invasive ability of lung cancer cells both in vitro and in vivo. Our data reveal that p120-catenin gene knockdown enhances the metastasis of lung cancer cells, probably by either depressing cell-cell adhesion due to lower levels of E-cadherin and beta-catenin, or altering the activity of small GTPase, such as inactivation of RhoA and activation of Cdc42/Rac1.

BACKGROUND: Kaiso is a recently identified transcription factor that binds to p120-catenin (p120ctn), an Armadillo catenin and cell adhesion cofactor. However, clinical studies of human solid tumors have not been reported to investigate relationship between these proteins. METHODS: expression and localization of Kaiso and p120ctn were examined in 196 lung cancer specimens (including 55 cases of paired lymph node metastases and 80 cases with complete follow-up records) by immunohistochemistry. Three lung cancer cell lines, BE1, SPC, and A549 were used to establish p120ctn stably ablated or overexpressed cell lines. Co-immunoprecipitation was used to confirm p120ctn bind Kaiso in lung cancer tissue and cell lines. Localization and expression levels of Kaiso were detected via immunofluorescence, cytoplasmic vs. nuclear fractionation Western blot analysis and reverse transcription-polymerase chain reaction. RESULTS: Cytoplasmic Kaiso expression was evident in 115 (58.7%), and abnormal p120ctn expression was noted in 168 (85.7%). Cytoplasmic Kaiso and abnormal p120ctn expressions were associated with higher degree of malignancy (high-stage and lymph node metastases, all P<0.05). Abnormal p120ctn and cytoplasmic Kaiso expressions were higher in matched autologous nodal metastases than in primary growths. The lung cancer-related 5-year survival rate was significantly lower in patients who were cytoplasmic Kaiso-positive (22.9%; P=0.029) or abnormal p120ctn expression (20.6%; P=0.001). Multivariate analysis showed abnormal p120ctn expression was an independent factor defining the clinicopathological characters of patients. Cytoplasmic Kaiso expression was correlated with cytoplasmic p120ctn, they formed Kaiso-p120ctn complex in lung cancer tissues and cell lines. In addition, p120ctn ablation and overexpression altered Kaiso subcellular localization and protein level. Although both isoforms can regulate subcellular localization and protein levels of Kaiso, we found that only p120ctn isoform 3, but not isoform 1, directly interacts with Kaiso. CONCLUSION: p120ctn and Kaiso might co-participate in the progression and lymph node metastasis of lung cancer. p120ctn regulates expression and localization of Kaiso in lung cancer cells.

Different p120ctn isoforms exert different, even opposing, effects on tumor cell growth depending on the level of E-cadherin expression, but the impact on clinicopathological parameters of lung cancer patients is not clear. Herein, we investigate the correlation between pan-p120ctn, p120ctn isoform 1, and E-cadherin expression and clinicopathological parameters, especially prognosis, of lung cancer patients. Immunohistochemistry on 20 specimens of normal bronchial epthelium revealed that, p120ctn isoform 1 was not expressed at the membrane; only weak cytoplasmic expression was seen. In contrast, both pan-p120ctn and E-cadherin were expressed clearly on the cell membrane or in the cytoplasmic peri-membrane region. However, in squamous cell lung cancer or lung adenocarcinomas, p120ctn isoform 1 over-expressed in the cytoplasm accompany with the abnormal pan-p120ctn and E-cadherin cytoplasm expression. p120ctn isoform 1 over-expression correlated positively with lymph node metastasis, poor differentiation, histological type, and high TNM stage. Cytoplasmic p120ctn isoform 1 expression in metastatic nodules was always higher than in the primary tumor. While the mean survival times of patients with normal p120 ctn isoform 1 or pan-p120ctn expression differed significantly, the mean survival times of patients with abnormal expression were similar. Lymph node metastasis, TNM stage, abnormal pan-p120ctn expression, and p120ctn isoform 1 over-expression were all independent factors affecting the prognosis of lung cancer patients. Over-expression of p120ctn isoform 1 positively correlated with poor prognosis of lung cancer patients, and therefore may be a useful marker of lung cancer patient survival.

OBJECTIVE: To study the expression of E-cadherin and P(120ctn) in nasopharyngeal carcinoma tissues, and to investigate their relationship and the relation with clinico-pathological features. METHOD: Two-step immunohistochemical staining was applied to detect the expression of E-cadherin and P(120ctn) in formalin fixation and paraffin-embedded specimens from 56 cases with nasopharyngeal carcinoma and 15 cases with normal nasopharyngeal epithelia. RESULT: The abnormal expression rates of E-cadherin and P(120ctn) in the 56 cases of NPC tissues were 64.29% and 67.86% respectively, mainly with reduction of expression membrane and with the expression of cytoplasm; 6.67% of the 15 comparative normal cases of nasopharyngitis had abnormal expression of E-cadherin and P(120ctn). The differences were statistically significant. The abnormal expression rates of E-cadherin and P(120ctn) in NPC tissues were 71.43% and 85.71% respectively in low differentiated cancer group, which was obviously higher than the rates-42.86% and 36.29%-in high and middle differentiated cancer group. The 80.00% and 85.00% abnormal expression rate in the group with cervical lymph node metastases was higher than that in the group without cervical lymph node metastases (52.78%, 58.33%). The abnormal expression rate of E-cadherin and P(120ctn) (76.92%, 84.62%) in the third and forth phases was higher than that in the first and second phases (46.66%, 53.33%). The differences were statistically significant (P < 0.05). There were all together 12 co-expression cases of P120ctn) and E-cadherin and 28 abnormal co-expression cases in the 56 cases of NPC tissues, which was of obvious consistency and correlation, with the relevant indexes: rs = 0.5217 and P < 0.01. CONCLUSION: The abnormal expression of E-cadherin and P(120ctn) is closely related to the degree of differentiation, clinical stage and cervical lymph node metastasis, and they join in the process of NPC initiation, progression, invasion and metastasis.

As a member of adherens junction, p120-catenin (p120ctn) plays a major role in cell adhesions through stabilization of E-cadherin. p120ctn is transcriptionally down-regulated in non-small cell lung cancer (NSCLC), although the molecular mechanisms underlying p120ctn repression are incompletely defined. Here we further investigated transcriptional regulation of p120ctn in NSCLC. We prepared a promoter reporter plasmid construct that contained p120ctn promoter region from position -1082 to +320 relative to transcription start site. Through serial deletion mutation analysis of the p120ctn promoter, we pinpointed cis-acting elements involved in regulation of p120ctn. We identified transcription factor SP1 as a transcriptional repressor of p120ctn that directly binds to segment (-9 to +36) of the p120ctn promoter. SP1 can receive multiple signals from several intracellular signaling pathways. Through examination of SP1 binding partners, we identified proto-oncogene c-Crk to be involved in transcriptional down-regulation of p120ctn. RNAi mediated silencing of CRK in A549, H157 and H358 cells increased p120ctn protein levels. On the other hand, over-expression of CRK-I and CRK-II in NSCLC cells down-regulated p120ctn, an effect that was abrogated by simultaneous silencing of SP1. In summary, our data provide evidence for the role of c-Crk proto-oncogene in transcriptional repression of p120ctn that further clarifies the mechanism by which this biochemical signal promotes metastasis in NSCLC.

Gonadotropin-releasing hormone (GnRH) is a potent prometastatic factor in ovarian cancer, but the intracellular signaling events are not well understood. The classical Galpha(q)-phospholipase C signal transduction pathway known to operate in the pituitary is not involved in GnRH actions at non-pituitary targets. Here we showed that GnRH treatment of ovarian cancer cells led to a rapid and remarkable tyrosine phosphorylation of p120 catenin (p120(ctn)), which was mediated by P-cadherin. The use of P-cadherin small interfering RNA or neutralizing antibodies to inhibit P-cadherin expression and function resulted in diminished p120(ctn) activation, confirming that the effect was P-cadherin specific. On exploring how P-cadherin, which lacks intrinsic kinase activity, might regulate the activation of p120(ctn), we found that P-cadherin could induce the ligand-independent activation of insulin-like growth factor-1 receptor (IGF-1R). Inhibition of IGF-1R expression or its activity significantly inhibited GnRH-induced p120(ctn) activation, and the subsequent cell migration and invasion. In addition, we showed that IGF-1R regulation by P-cadherin was associated with complex formation between IGF-1R and P-cadherin, and this regulation was also observed to be in vivo correlated with metastasis. Furthermore, using a mouse model of ovarian cancer metastasis, GnRH receptor knockdown was shown to diminish peritoneal dissemination of tumors and ascites formation. These findings suggest for the first time that GnRH can initiate an outside-in p120(ctn) signal transduction through the cross-talk between P-cadherin and IGF-1R, thus providing a novel molecular mechanism by which GnRH may control the high level of aggressiveness and invasion and metastasis potential that are characteristic of ovarian cancer.