Anoikis-related CTNND1 is associated with immuno-suppressive tumor microenvironment and predicts unfavorable immunotherapeutic outcome in non-small cell lung cancer

Background: Immunotherapy has greatly changed the treatment of advanced non-small cell lung cancer (NSCLC). Anoikis is a programmed cell death process associated with cancer. However, the correlation between anoikis-related genes and the tumor microenvironment (TME) features and immunotherapeutic outcome in NSCLC has not been fully explored. Methods: The bulk and single-cell transcriptome data of NSCLC were downloaded from TCGA and GEO databases. The distribution of anoikis-related genes on different cell types at the single-cell level was analyzed, and these genes specifically expressed by tumor cells and immunotherapy-related were further extracted. Next, the candidate gene CTNND1 was identified and its correlations with the TME features and immunotherapeutic outcome in NSCLC were explored in multiple public cohorts. Finally, an in-house cohort was used to determine the CTNND1 expression and immuno-correlation in NSCLC. Results: At single-cell atlas, we found that anoikis-related genes expressed specifically in tumor cells of NSCLC. By intersecting anoikis-related genes, immunotherapy-associated genes, and the genes expressed in tumor cells, we obtained a special biomarker CTNND1. In addition, cell-cell communication analysis revealed that CTNND1+ tumor cells communicated with immune subpopulations frequently. Moreover, we found that high expression of CTNND1 was related to immuno-suppressive status of NSCLC. The expression of CTNND1 and its immuno-correlation were also validated, and the results showed that CTNND1 was highly expressed in NSCLC tissues and tumors with high CTNND1 expression accompanied with low CD8+ T cells infiltration. Conclusions: Overall, our study reported that CTNND1 can be considered as a novel biomarker for the predication of immunotherapeutic responses and a potential target for NSCLC therapy.

Mechanisms Underlying Rare Inherited Pediatric Retinal Vascular Diseases: FEVR, Norrie Disease, Persistent Fetal Vascular Syndrome

Familial Exudative Vitreoretinopathy (FEVR), Norrie disease, and persistent fetal vascular syndrome (PFVS) are extremely rare retinopathies that are clinically distinct but are unified by abnormal retinal endothelial cell function, and subsequent irregular retinal vascular development and/or aberrant inner blood-retinal-barrier (iBRB) function. The early angiogenesis of the retina and its iBRB is a delicate process that is mediated by the canonical Norrin Wnt-signaling pathway in retinal endothelial cells. Pathogenic variants in genes that play key roles within this pathway, such as NDP, FZD4, TSPAN12, and LRP5, have been associated with the incidence of these retinal diseases. Recent efforts to further elucidate the etiology of these conditions have not only highlighted their multigenic nature but have also resulted in the discovery of pathological variants in additional genes such as CTNNB1, KIF11, and ZNF408, some of which operate outside of the Norrin Wnt-signaling pathway. Recent discoveries of FEVR-linked variants in two other Catenin genes (CTNND1, CTNNA1) and the Endoplasmic Reticulum Membrane Complex Subunit-1 gene (EMC1) suggest that we will continue to find additional genes that impact the neural retinal vasculature, especially in multi-syndromic conditions. The goal of this review is to briefly highlight the current understanding of the roles of their encoded proteins in retinal endothelial cells to understand the essential functional mechanisms that can be altered to cause these very rare pediatric retinal vascular diseases.

Case report: "Major fetal cardiac pathology associated with a novel CTNND1 mutation"

Background

The p120-ctn protein, encoded by CTNND1, is involved in intercellular connections and regulates epithelial-mesenchymal transformation. CTNND1 mutations can lead to blepharocheilodontic syndrome (BCDS). Increasing evidence shows that although BCDS mainly manifests as craniofacial and oral deformities, it can also present as congenital heart disease, limb deformities, and neurodevelopmental disorders.

Case description

We report a prenatal case of a major cardiac malformation at 24⁺³ weeks of gestation. Ultrasound examination revealed a hypoplastic left ventricular, aortic coarctation, and a ventricular septal defect. Genetic analysis of the fetal tissues showed the presence of a novel mutation in CTNND1 (NM_001085458.2: c.566_c.567insG; p.Pro190fs*15), which may lead to premature termination of protein coding, while both the parents harbored wild-type CTNND1. To date, only 15 CTNND1 mutations have been reported in 19 patients worldwide, of which approximately 31% (6/19) had a cardiac phenotype.

Conclusion

To the best of our knowledge, this is the first case report of fetal complicated cardiac malformations caused by this CTNND1 mutation. Our findings provide new clinical references for prenatal diagnosis and suggest an important role for CTNND1 in early cardiac development.

The E3 ubiquitin ligase MIB1 suppresses breast cancer cell migration through regulating CTNND1 protein level

Breast cancer is one of the most common invasive cancers among women. The leading cause of difficulty in treating breast cancer patients is metastasis. Because cell migration is closely related to breast cancer metastasis, elucidating the detailed mechanism by which breast cancer cells promote their migration is crucial for improving the prognosis of patients. In this study, we investigated the relationship between breast cancer cell migration and Mind bomb1 (MIB1), an E3 ubiquitin ligase. We found that the downregulation of MIB1 promotes the cell migration of MCF7, a breast cancer-derived cell line. Furthermore, knockdown of MIB1 caused a reduction in CTNND1 and thereby impaired E-cadherin membrane localization in the cell boundary region. Taken together, our data suggest that MIB1 might play a role in suppressing breast cancer cell migration.

β-cells retain a pool of insulin-containing secretory vesicles regulated by adherens junctions and the cadherin binding protein p120 catenin

The β-cells of the islets of Langerhans are the sole producers of insulin in the human body. In response to rising glucose levels, insulin-containing vesicles inside β-cells fuse with the plasma membrane and release their cargo. However, the mechanisms regulating this process are only partly understood. Previous evidence indicated reductions in α-catenin elevate insulin release, while reductions in β-catenin decrease insulin release. α- and β-catenin contribute to cellular regulation in a range of ways but one is as members of the adherens junction complex and these contribute to the development of cell polarity in b-cells. Therefore, we investigated the effects of adherens junctions on insulin release. We show in INS-1E β-cells knockdown of either E- or N-cadherin had only small effects on insulin secretion, but simultaneous knockout of both cadherins resulted in a significant increase in basal insulin release to the same level as glucose-stimulated release. This double knockdown also significantly attenuated levels of p120 catenin, a cadherin binding partner involved in regulating cadherin turnover. Conversely, reducing p120 catenin levels with siRNA destabilized both E- and N-cadherin, and this was also associated with an increase in levels of insulin secreted from INS-1E cells. Furthermore, there were also changes in these cells consistent with higher insulin release, namely reductions in levels of F-actin and increased intracellular free Ca²⁺ levels in response to KCl-induced membrane depolarization. Taken together, these data provide evidence that adherens junctions play important roles in retaining a pool of insulin secretory vesicles within the cell and establish a role for p120 catenin in regulating this process.

Downregulated circular RNA hsa_circ_0005797 inhibits endometrial cancer by modulating microRNA-298/Catenin delta 1 signaling

Abnormal expression of circular RNA (circRNA) expression has been implicated in endometrial cancer (EC) progression. Thus, investigation of the mechanism of hsa_circ_0005797 during EC etiology may provide new insight into the treatment of EC. In the present study, we found that hsa_circ_0005797 expression was significantly increased in EC biological samples and cell lines, whereas its downregulation inhibited in vitro tumor cells proliferation and invasion phenotypes and suppressed tumor formation in nude mice. In mechanism, we characterized hsa_circ_0005797 as an miR-298 sponge, with CTNND1 identified as a target of miR-298. Our rescue assay data further revealed that hsa_circ_0005797 silencing inhibited EC cells proliferation and invasion via miR-298/CTNND1 signaling. In conclusion, our study confirmed hsa_circ_0005797 is a poor prognostic factor for EC and modulates EC phenotypes by regulating the hsa_circ_000579/miR-298/CTNND1 signaling, which provides potential treatment targets for EC

Silencing CTNND1 Mediates Triple-Negative Breast Cancer Bone Metastasis via Upregulating CXCR4/CXCL12 Axis and Neutrophils Infiltration in Bone

Simple Summary

Distant metastasis, especially bone metastasis, is the major cause of death in breast cancer patients. However, breast cancer patients with bone metastasis are frequently complicated by delayed intervention as clinically bone metastasis cannot be detected early enough. Here, we report that CTNND1 is downregulated in both primary tumors and metastatic bone lesions of patients with triple-negative breast cancer (TNBC). Decreased CTNND1 is a crucial intrinsic contributor to homing to the bones and the survival of the breast cancer cells in the bone microenvironment. Thus, CTNND1 may be a novel biomarker for early predicting bone metastasis of triple-negative breast cancer.

Abstract

Bone metastasis from triple-negative breast cancer (TNBC) frequently results in poorer prognosis than other types of breast cancer due to the delay in diagnosis and intervention, lack of effective treatments and more skeletal-related complications. In the present study, we identified CTNND1 as a most reduced molecule in metastatic bone lesion from TNBC by way of high throughput sequencing of TNBC samples. In vivo experiments revealed that knockdown of CTNND1 enhanced tumor cells metastasis to bones and also increased neutrophils infiltration in bones. In vitro, we demonstrated that knockdown of CTNND1 accelerated epithelial–mesenchymal transformation (EMT) of tumor cells and their recruitment to bones. The involvement by CTNND1 in EMT and bone homing was achieved by upregulating CXCR4 via activating the PI3K/AKT/HIF-1αpathway. Moreover, TNBC cells with reduced expression of CTNND1 elicited cytotoxic T-cells responses through accelerating neutrophils infiltration by secreting more GM-CSF and IL-8. Clinically, patients with triple-negative breast cancer and lower level of CTNND1 had shorter overall survival (OS) and distant metastasis-free survival (DMFS). It was concluded that downregulation of CTNND1 played a critical role in facilitating bone metastasis of TNBC and that CTNND1 might be a potential biomarker for predicting the risk of bone metastases in TNBC.

Effects of advanced glycation end products on neutrophil migration and aggregation in diabetic wounds

Increased accumulation of advanced glycation end products (AGEs) in diabetic skin is closely related to delayed wound healing. Studies have shown that the concentration of AGEs is elevated in the skin tissues and not subcutaneous tissues in refractory diabetic wounds, which suggests there may be a causal relationship between the two. In the present study, in vitro experiments revealed that AGEs activated neutrophils, and the migratory and adhesive functions of neutrophils decreased once AGE levels reached a certain threshold. Different levels of AGE expression differentially affected the function of neutrophils. Messenger RNA (mRNA) sequencing analysis combined with real-time polymerase chain reaction (PCR) showed that poliovirus receptor (PVR/CD155) and CTNND1, which play a role in migration- and adhesion-related signaling pathways, were decreased following AGE stimulation. Consequently, neutrophils cannot effectively stimulate the formation of the inflammatory belt needed to remove necrotic tissues and defend against foreign microorganisms within diabetic chronic wounds. In addition, this phenomenon may be related to the differential accumulation of AGEs in different layers of the skin.

Hydrodynamic forces influence the gene transcription of mechanosensitive intercellular junction associated genes in corneal endothelial cells

Mechanicals forces are known to influence cell behavior. In vivo, the corneal endothelium is under the influence of various mechanical forces, such as intraocular pressure (IOP) and fluid flow. In this study, we used a corneal bioreactor to understand the effect of these hydrodynamic forces on the transcription of intercellular junctions associated genes in the corneal endothelium. Native and tissue-engineered (TE) corneal endothelium were cultured in a corneal bioreactor for 7 days with 16 mmHg IOP and 5 μl/ml of medium flow. RNA was harvested, and gene expression was quantified. Cells that were used to reconstruct the TE corneal endothelia were also seeded on plastic to characterize their morphology by calculating their circularity index. For native endothelia, hydrodynamic forces increased gene expression of GJA1 (connexin 43), CDH2 (N-cadherin), TJP1 (ZO-1), ITGAV (integrin subunit αv), ITGB5 (integrin subunit β5) and CTNND1 (p120-ctn) by 1.68 ± 0.40, 1.10 ± 0.27, 3.80 ± 0.56, 1.82 ± 0.33, 1.32 ± 0.21 and 3.04 ± 0.63, respectively. For TE corneal endothelium, this fold change was 1.72 ± 0.31, 1.58 ± 0.41, 6.18 ± 1.03, 1.80 ± 0.71, 1.77 ± 0.55, 2.42 ± 0.71. Furthermore, gene transcription fold changes (hydrodynamic/control) increased linearly with TE corneal endothelium cells population morphology with r = 0.83 for TJP1 (ZO-1) and r = 0.58 for CTNND1 (p120-ctn). In fact, the more elongated the cells populations were, the greater hydrodynamic conditions increased the transcription of TJP1 (ZO-1) and CTNND1 (p120-ctn). These results suggest that hydrodynamic forces contribute to the maintenance of tight and adherens junctions of native corneal endothelial cells, as well as to the formation of tight and adherens junctions of corneal endothelial cells that are in the process of forming a functional endothelial barrier.

Circular RNA circ_0000043 promotes endometrial carcinoma progression by regulating miR-1271-5p/CTNND1 axis

BACKGROUND

Circular RNAs (circRNAs) are involved in a variety of biological processes, including tumorigenesis. However, the exact role and molecular mechanisms of circ_0000043 in endometrial carcinoma (EC) remain largely unknown.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to determine the expression levels of circ_0000043, microRNA-1271-5p (miR-1271-5p) and catenin delta 1 (CTNND1). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to measure cell proliferation, cell apoptosis and cell cycle distribution, respectively. Cell migration and invasion were assessed by transwell assay. Western blot assay was performed to examine the protein expression of matrix metalloproteinase 2 (MMP2), MMP9 and CTNND1. The interaction between miR-1271-5p and circ_0000043 or CTNND1 was predicted by starBase and confirmed by dual-luciferase reporter assay. The mice xenograft model was established to investigate the role of circ_0000043 in vivo.

RESULTS

Circ_0000043 and CTNND1 were highly expressed and miR-1271-5p was lowly expressed in EC tissues and cells. Knockdown of circ_0000043 inhibited the progression of EC by inhibiting cell proliferation, migration, invasion and tumor growth (in vivo) and promoting apoptosis. MiR-1271-5p was a direct target of circ_0000043 and its inhibition reversed the inhibitory effect of circ_0000043 knockdown on the progression of EC cells. In addition, CTNND1 was a downstream target of miR-1271-5p, and miR-1271-5p overexpression inhibited EC cell proliferation, migration and invasion and induced apoptosis by targeting CTNND1. Moreover, circ_0000043 positively regulated CTNND1 expression by sponging miR-1271-5p.

CONCLUSION

Circ_0000043 knockdown inhibited the progression of EC by regulating miR-1271-5p/CTNND1 axis, which might provide a promising circRNA-targeted therapy for EC.

Long non-coding RNA KCNQ1OT1 up-regulates CTNND1 by sponging miR-329-3p to induce the proliferation, migration, invasion, and inhibit apoptosis of colorectal cancer cells

Background

Long non-coding RNAs (lncRNAs) have been certified to be involved in the occurrence and growth of diverse cancers, including CRC. The purpose of the research was to explore the effects of lncRNA KCNQ1 overlapping transcript 1 (KCNQ1OT1) on proliferation, migration, invasion, and apoptosis in CRC cells and its mechanism.

Methods

The levels of KCNQ1OT1 and miR-329-3p were examined by quantitative real-time polymerase chain reaction (qRT-PCR) in CRC tissues and cells. The mRNA and protein levels of catenin delta-1 (CTNND1) were measured by qRT-PCR and western blot analysis, respectively. The targets of KCNQ1OT1 and miR-329-3p were predicted by online software and confirmed by luciferase reporter assay. The cell proliferation, migration, invasion, and apoptosis were examined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), transwell, and apoptosis assay. The expression levels of CyclinD1, Bcl-2, MMP9, Cleaved-casp-3, and E-cadherin in SW480 and LS1034 cells were gauged by western blot analysis. Xenograft tumor model was structured to prove the biological role of KCNQ1OT1 of CRC in vivo.

Results

The levels of KCNQ1OT1 and CTNND1 were significantly increased in CRC tissues and cells. Knockdown of KCNQ1OT1 suppressed proliferation, migration, invasion, and induced apoptosis in CRC cells. Conversely, CTNND1 overexpression reversed the impact of KCNQ1OT1 knockdown on CRC cells. Moreover, CTNND1 was verified as a direct target of miR-329-3p, and miR-329-3p could specially bind to KCNQ1OT1. Also, the down-regulation of KCNQ1OT1 triggered the CRC progress by up-regulating CTNND1 expression in CRC cells. Besides, KCNQ1OT1 knockdown inhibited CRC tumor growth through the miR-329-3p/CTNND1 axis in vivo.

Conclusion

Our results indicated that KCNQ1OT1 could positively regulate CTNND1 expression by sponging miR-329-3p, thereby boosting the progression of CRC. Our findings provided the underlying therapy targets for CRC.

SNHG29 regulates miR-223-3p/CTNND1 axis to promote glioblastoma progression via Wnt/β-catenin signaling pathway

Background

Glioblastoma has been seen as the most common malignancy of brain tumor. Emerging reports has claimed that SNHG29 (LRRC75A-AS1) was involved in several biological processes via modulation of signaling pathway, and served as an malignant facilitatorin osteosarcoma. However, the specific role of SNHG29 in glioblastoma remains unknown.

Methods

RT-qPCR and microarray were operated to measure genes expression. Western blot was performed to examine protein expression. CCK-8 and colony formation assays were used to evaluate cell proliferation. Cell migration was tested by transwell assay. Nuclear-cytoplasmic fractionation was conducted to locate SNHG29. The binding capacity of miR-223-3p to SNHG29 or CTNND1 3′UTR was verified by RIP and luciferase reporter assay.

Results

SNHG29 presented high expression in glioblastoma to boost cell proliferation, migration and EMT process. In addition, miR-223-3p was validated to bind with SNHG29 after prediction and screening. Furthermore, miR-223-3p was proved to be a negative regulator for its target CTNND1. Then, the inhibition on cell proliferation, migration and EMT process resulted from SNHG29 knockdown was recovered by CTNND1 overexpression. At last, the inhibitive impacts on cell proliferation, migration and EMT process of CTNND1 deficiency was abrogated by LiCl.

Conclusions

In conclusion, SNHG29 regulates miR-223-3p/CTNND1 axis to promote glioblastoma progression via Wnt/β-catenin signaling pathway, offering a potential therapeutic point for glioblastoma patients.

Hsa_circ_0002577 promotes endometrial carcinoma progression via regulating miR-197/CTNND1 axis and activating Wnt/β-catenin pathway

Circular RNA (circRNA) is involved in a wide range of life processes including tumorigenesis. However, the molecular mechanisms of circRNA in endometrial carcinoma (EC) carcinogenesis remain unclear. In the present study, we aimed to investigate the potential modulation of hsa_circ_0002577 on EC progression. Here, we showed that hsa_circ_0002577 expression was significantly upregulated in EC tissues, and high hsa_circ_0002577 expression was associated with advanced FIGO stage, lymph node metastasis, and poor overall survival rate of EC patients. In function assays, we demonstrated that hsa_circ_0002577 knockdown significantly reduced EC cells proliferation, migration, invasion ability in vitro and decreased tumor growth in vivo. In mechanism study, we revealed that hsa_circ_0002577 might act as a sponge for miR-197, and CTNND1 was revealed to be a target gene of miR-197. In addition, we revealed that the oncogenic effects of hsa_circ_0002577 were attributed to the regulation of miR-197/CTNND1/Wnt/β-catenin axis. Taken together, we indicated that hsa_circ_0002577 could play critical functions by hsa_circ_0002577/miR-197/CTNND1/Wnt/β-catenin signaling pathway, which served as a novel therapeutic application for EC treatment.

MicroRNA-143-3p suppresses tumorigenesis by targeting catenin-δ1 in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third most common malignancy in the United States. Mounting microRNAs (miRNAs) have been identified as oncogenes or tumor suppressors in various cancers including CRC.

MATERIALS AND METHODS

The levels of microRNA-143-3p (miR-143-3p) and catenin-δ1 (CTNND1) were determined by RT-qPCR assay. Cell proliferative ability was assessed by Cell Counting Kit-8 assay. Cell migratory and invasive capacities were measured by transwell migration and invasion assay. Luciferase reporter assay was conducted to explore whether miR-143-3p could bind with CTNND1 3'UTR. CTNND1 protein level was determined through Western blot assay. Mouse xenograft models of CRC were established to test the functions and molecular basis of miR-143-3p in the development of CRC in vivo.

RESULTS

Low amounts of miR-143-3p were expressed in CRC tissues and cells. Functional analysis revealed that miR-143-3p overexpression suppressed cell proliferation, migration and invasion in CRC. Molecular mechanism exploration indicated that miR-143-3p directly targeted CTNND1. Moreover, enforced expression of CTNND1 contributed to cell proliferation, migration and invasion in CRC, and CTNND1 silencing exerted opposite effects. Restoration experiments disclosed that CTNND1 upregulation weakened the inhibitory effects of miR-143-3p on CRC cell proliferation, migration and invasion. Additionally, miR-143-3p inhibited the growth of HCT116-derived xenograft tumors by targeting CTNND1 in vivo.

CONCLUSION

miR-143-3p hampered the development and progression of CRC by targeting CTNND1 in vitro and in vivo, deepening our understanding of the functions and molecular basis of miR-143-3p in the tumorigenesis of CRC and providing some candidate prognostic markers or therapeutic targets for CRC.

p120ctn-Mediated Organ Patterning Precedes and Determines Pancreatic Progenitor Fate

The mechanism of how organ shape emerges and specifies cell fate is not understood. Pancreatic duct and endocrine lineages arise in a spatially distinct domain from the acinar lineage. Whether these lineages are pre-determined or settle once these niches have been established remains unknown. Here, we reconcile these two apparently opposing models, demonstrating that pancreatic progenitors re-localize to establish the niche that will determine their ultimate fate. We identify a p120ctn-regulated mechanism for coordination of organ architecture and cellular fate mediated by differential E-cadherin based cell sorting. Reduced p120ctn expression is necessary and sufficient to re-localize a subset of progenitors to the peripheral tip domain, where they acquire an acinar fate. The same mechanism is used re-iteratively during endocrine specification, where it balances the choice between the alpha and beta cell fates. In conclusion, organ patterning is regulated by p120ctn-mediated cellular positioning, which precedes and determines pancreatic progenitor fate.

MicroRNA-298 represses hepatocellular carcinoma progression by inhibiting CTNND1-mediated Wnt/β-catenin signaling

MicroRNAs (miRNAs) are solid factors involved in the initiation and progression of hepatocellular carcinoma (HCC). Recently, miR-298 is recognized as a cancer-associated miRNA in breast, gastric and ovarian cancer. However, the functional role of miR-298 and its underlying mechanism are rarely reported in HCC. Herein, we found that the expression of miR-298 was down-regulated in HCC tissues and cell lines. The in vitro experiments showed that miR-298 overexpression inhibited cell proliferation, migration and invasion, and induced G1 arrest and apoptosis of HCC cells. miR-298 knockdown exerted an opposite effect on these cellular behaviors of HCC cells. Moreover, miR-298 restoration suppressed HCC tumor growth and metastasis in vivo. Additionally, catenin delta 1 (CTNND1) was demonstrated to be a direct target of miR-298 in HCC cells. CTNND1 knockdown led to similar effects with miR-298 overexpression on HCC cell proliferation, cell cycle progression, apoptosis and mobility. CTNND1 restoration reversed miR-298-induced inhibitory effects on HCC cells. Mechanistically, both miR-298 overexpression and CTNND1 knockdown repressed Wnt/β-catenin signaling and resulted in reduced expression of β-catenin, WNT11, Cyclin D1 and MMP7 in HCCLM3 cells. While, CTNND1 restoration abolished miR-298-induced inactivation of Wnt/β-catenin signaling. In conclusion, our findings provide the first evidence that miR-298 suppresses HCC progression at least partially by targeting CTNND1-mediated Wnt/β-catenin signaling. MiR-298 may be a target for new therapies in HCC patients.

Divergent roles of p120-catenin isoforms linked to altered cell viability, proliferation, and invasiveness in carcinogen-induced rat skin tumors

The heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) targets multiple organs for tumorigenesis in the rat, including the colon and the skin. PhIP-induced skin tumors were subjected to mutation screening, which identified genetic changes in Hras (7/40, 17.5%) and Tp53 (2/40, 5%), but not in Ctnnb1, a commonly mutated gene in PhIP-induced colon tumors. Despite the absence of Ctnnb1 mutations, β-catenin was overexpressed in nuclear and plasma membrane fractions from PhIP-induced skin tumors, coinciding with loss of p120-catenin from the plasma membrane, and the appearance of multiple p120-catenin-associated bands in the nuclear extracts. Real-time RT-PCR revealed that p120-catenin isoforms 1 and 4 were upregulated in PhIP-induced skin tumors, whereas p120-catenin isoform 3 was expressed uniformly, compared with adjacent normal-looking tissue. In human epidermoid carcinoma and colon cancer cells, transient transfection of p120-catenin isoform 1A enhanced the viability and cell invasion index, whereas transient transfection of p120-catenin isoform 4A increased cell viability and cell proliferation. Knockdown of p120-catenin revealed a corresponding reduction in the expression of β-catenin and a transcriptionally regulated target, Ccnd1/Cyclin D1. Co-immunoprecipitation experiments identified associations of β-catenin with p120-catenin isoforms in PhIP-induced skin tumors and human cancer cell lines. The results are discussed in the context of therapeutic strategies that might target different p120-catenin isoforms, providing an avenue to circumvent constitutively active β-catenin arising via distinct mechanisms in skin and colon cancer.

Overexpression of CTNND1 in hepatocellular carcinoma promotes carcinous characters through activation of Wnt/β-catenin signaling

Background

Increasing evidence supports the association of CTNND1 with tumor development and progression. However, the mechanism and clinical significance of CTNND1 deregulation in hepatocellular carcinoma (HCC) remains unknown. In this study, we aim to investigate the role of CTNND1 in HCC.

Methods

qRT-PCR and immunohistochemical analyses were used to measure the levels of CTNND1 in HCC specimens and HCC cell lines. CTNND1 and shCTNND1 were transfected into HCC cell lines to investigate its role in HCC. Cell migration and invasion were measured by Transwell and Matrigel analyses in vitro. In vivo metastasis assays were performed in SCID mice.

Results

In clinical HCC samples, we found that CTNND1 expression was significantly up-regulated in cancer lesions compared with paired normal liver tissues. By silencing or overexpressing CTNND1 in HCC cells, we found that CTNND1 could promote cell proliferation, migration, and invasion in vitro. An in-vivo assay showed that CTNND1 dramatically promoted HCC cell tumor formation and metastasis. Moreover, CTNND1 promoted HCC metastasis, at least in part, by indirectly enhancing Wnt/β-catenin signaling. Consistent with these results, the expression of CTNND1 was positively correlated with β-catenin, WNT11, Cyclin D1, and BMP7 expression in human HCC specimens.

Conclusions

Our study provides evidence that CTNND1 functions as a novel tumor oncogene in HCC, and may be a potential therapeutic target for HCC management.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0344-9) contains supplementary material, which is available to authorized users.

Catenin-δ1, negatively regulated by miR-145, promotes tumour aggressiveness in gastric cancer

Increasing evidence supports the association of catenin-δ1 (CTNND1, p120ctn) with tumour development and progression. However, the mechanism and clinical significance of CTNND1 deregulation in gastric cancer remain unknown. The expression level and cellular localization of CTNND1 were determined by immunohistochemistry in 126 human gastric cancer and 50 non-tumourous tissues. The cellular localization of CTNND1 and epithelial cadherin (E-cadherin) were detected by immunofluorescence. Cell proliferation, apoptosis, migration and invasion assays were performed to assess the effect of CTNND1 cDNA or CTNND1 siRNA transfection on gastric cancer cells. Luciferase assay, western blot analysis and in vivo assays were used to determine whether CTNND1 could be regulated by miR-145. The results demonstrate that the cytoplasmic localization of CTNND1 protein, rather than expression level, was indicative of higher clinical stage, positive lymph node metastasis and poorer prognosis in gastric cancers. CTNND1 could promote gastric cancer cell migration and invasion with little effect on cellular proliferation and apoptosis. CTNND1 was proved to be a direct target gene for miR-145. Besides suppressing cytoplasmic CTNND1 expression, miR-145 could recover the membranous localization of CTNND1 and E-cadherin. We conclude that cytoplasmic CTNND1 can serve as an independent prognostic factor for patients with gastric cancers. MiR-145 inhibits invasion of gastric cancer cells not only by down-regulating cytoplasmic CTNND1 expression but also by inducing the translocation of CTNND1 and E-cadherin from the cytoplasm to the cell membrane through down-regulating N-cadherin.