Cytoplasmic beta-catenin accumulation is a good prognostic marker in upper and lower gastrointestinal adenocarcinomas

Prevention of epithelial to mesenchymal transition in colorectal carcinoma by regulation of the E-cadherin-β-catenin-vinculin axis

Epithelial to mesenchymal transition (EMT) is compulsory for metastatic dissemination and is stimulated by TGF-β. Although targeting EMT has significant therapeutic potential, very few pharmacological agents have been shown to exert anti-metastatic effects. BI-69A11, a competitive Akt inhibitor, displays anti-tumor activity toward melanoma and colon carcinoma. This study provides molecular and biochemical insights into the effects of BI-69A11 on EMT in colon carcinoma cells in vitro and in vivo. BI-69A11 inhibited metastasis-associated cellular migration, invasion and adhesion by inhibiting the Akt-β-catenin pathway. The underlying mechanism of BI-69A11-mediated inhibition of EMT included suppression of nuclear transport of β-catenin and diminished phosphorylation of β-catenin, which was accompanied by enhanced E-cadherin-β-catenin complex formation at the plasma membrane. Additionally, BI-69A11 caused increased accumulation of vinculin in the plasma membrane, which fortified focal adhesion junctions leading to inhibition of metastasis. BI-69A11 downregulated activation of the TGF-β-induced non-canonical Akt/NF-κB pathway and blocked TGF-β-induced enhanced expression of Snail causing restoration of E-cadherin. Overall, this study enhances our understanding of the molecular mechanism of BI-69A11-induced reversal of EMT in colorectal carcinoma cells in vitro, in vivo and in TGF-β-induced model systems.

Tetrandrine suppresses adhesion, migration and invasion of human colon cancer SW620 cells via inhibition of nuclear factor-κB, matrix metalloproteinase-2 and matrix metalloproteinase-9 signaling pathways

Tetrandrine (TET) exhibits biological activities, including anticancer activity. In Chinese medicine, TET has been used to treat hypertensive and arrhythmic conditions and has been demonstrated to induce cytotoxic effects on human cancer cell lines. However, to the best of the author's knowledge, no previous studies have revealed that TET affects cell metastasis in SW620 human colon cancer cells. The present study demonstrated that TET decreased the cell number and inhibited cell adhesion and mobility of SW620 cells. Furthermore, a wound healing assay was performed to demonstrate that TET suppressed cell movement, and Transwell chamber assays were used to reveal that TET suppressed the cell migration and invasion of SW620 cells. Western blotting demonstrated that TET significantly reduced protein expression levels of SOS Ras/Rac guanine nucleotide exchange factor 1, phosphatidylinositol 3-kinase, growth factor receptor bound protein 2, phosphorylated (p)-c Jun N-terminal kinase 1/2, p-p38, p38, 14-3-3, Rho A, β-catenin, nuclear factor-κB p65, signal transducer and activator of transcription-1 and cyclooxygenase-2, in comparison with untreated SW620 cells. Overall, the results of the present study suggested that TET may be used as a novel anti-metastasis agent for the treatment of human colon cancer in the future.

β-catenin interaction with NHERF1 and RASSF1A methylation in metastatic colorectal cancer patients

There is an increasing need to identify new biomarkers in colorectal cancer (CRC) to further characterize this malignancy. β-catenin plays a central role in the Wnt signaling pathway. It also binds Na⁺/H⁺ exchanger regulating factor 1 (NHERF1) and interacts with the RAS-association domain family 1, isoform A (RASSF1A), but the mechanisms of this possible crosstalk are still not fully understood. In this study, we analyzed for the first time the different subcellular expression of β-catenin, NHERF1, and RASSF1A and their relationships with RASSF1A methylation in the progression of CRC. We assessed immunohistochemical expression and RASSF1A methylation in 51 patients with stage IV colorectal cancer. Biomarker expression analysis was carried out considering the tumor-adjacent normal tissue, the primary tumor, and the paired liver metastases. Regarding the tumor compartment, it was found that cytoplasmic β-catenin expression was positively correlated to membranous (r = 0.3002, p = 0.0323) and nuclear NHERF1 (r = 0.293, p = 0.0368). In the liver metastases, instead, we found a positive correlation of cytoplasmic and nuclear β-catenin expression with RASSF1A methylation (r = 0.4019, p = 0.0068 and r = 0.3194, p = 0.0345, respectively).

In conclusion, our results showed that β-catenin was the crucial protagonist in metastatic CRC through different effector proteins involved in this developing process. In tumor tissues, β-catenin was predominantly associated with NHERF1 in a dynamic context, while interestingly in liver metastases, we noted an increase of its oncogenic function through RASSF1A inactivation.

Kuppen P. Prognostic Significance of Nuclear β-Catenin Expression in Patients with Colorectal Cancer from Iran

Background:

Beta catenin plays a key role in cancer tumorigenesis. However, its prognostic significance in patients with colorectal cancer (CRC) remains controversial. It has been demonstrated that 90% of all tumors have a mutation in individual components of multiple oncogenes in Wnt/β-catenin pathway. Accumulation of nuclear β-catenin in cytoplasm leads to uncontrolled cell proliferation. Thus, nuclear β-catenin accumulation may be a valuable biomarker associated with invasion, metastasis and poor prognosis of CRC.

Objectives:

In this study the prognostic value of beta catenin expression in 165 Iranian CRC patients was evaluated.

Patients and Methods:

In this cross sectional retrospective study immunohistochemistry analyses of formalin-fixed paraffin-embedded (FFPE) tumor tissues were performed to characterize the expression of nuclear β-catenin in a series of 165 Iranian patients with colorectal carcinoma. Heat-induced antigen retrieval using the microwave method was applied for all staining procedures. Staining was scored independently by two observers, and a high level of concordance (90%) was achieved. Statistical analysis was done using the SPSS software for Windows, version 13.0.0 (SPSS Inc., Chicago, IL). Two-tailed P < 0.05 was considered statistically significant.

Results:

The patients consisted of 85 males and 80 females. Eighty-eight patients had primary tumor of the rectum and sigmoid, while 77 patients had primary tumor of the colon. The mean period of follow-up was 47.2 ± 10 months and the median period of follow-up was 38 months (range 6 - 58) for each patient. Of 165 tumors, 32 tumors (19.39 %) showed expression of β-catenin and 133 (80.6 %) were negative for β-catenin expression. Based on our findings the distribution of Microsatellite Instability (MSI) status differed between patients with nuclear β-catenin positive and negative tumors and this difference was significant (P = 0.001). Patients with nuclear β-catenin positive expression profile were found to be younger than patients with negative nuclear β-catenin expression (P = 0.010). Univariate and multivariate analysis showed that tumors with β-catenin expression had a poorer prognosis compared to tumors without β-catenin expression.

Conclusions:

According to our findings, the distribution of nuclear b-catenin expression is a poor prognostic marker in patients with colon cancer.

Reporting in studies of protein biomarkers of prognosis in colorectal cancer in relation to the REMARK guidelines

PURPOSE

The REMARK guidelines give authors comprehensive and specific advice on the complete and transparent reporting of studies of prognostic tumor markers. The aim of this study was to use the REMARK guidelines to evaluate the quality of reporting in a sample of studies assessing tissue-based protein markers for survival after resection of colorectal cancer.

EXPERIMENTAL DESIGN

Eighty pertinent articles were scored according to their conformity to 26 items derived from the REMARK criteria.

RESULTS

Overall, on a scale of adequacy of reporting that potentially ranged from 26 to 78, the median for these studies was 60 (interquartile range 54-64) and several criteria were adequately covered in a large proportion of studies. However, others were either not dealt with or inadequately covered, including description of the study design (35%), definition of survival endpoints (48%), adjuvant therapy (54%), follow-up procedures and time (59%), neoadjuvant therapy (63%), inclusion/exclusion criteria (73%), multivariable modeling methods and results (74%), and discussion of study limitations (85%).

CONCLUSIONS AND CLINICAL RELEVANCE

Inadequacies in presentation militate against comparability among protein marker studies and undermine the generalizability of their findings. The quality of reporting could be improved if journal editors were to require authors to ensure that their work satisfied the REMARK criteria.

Prognostic Significance of β-Catenin, E-Cadherin, and SOX9 in Colorectal Cancer: Results from a Large Population-Representative Series

Robust biomarkers that can precisely stratify patients according to treatment needs are in great demand. The literature is inconclusive for most reported prognostic markers for colorectal cancer (CRC). Hence, adequately reported studies in large representative series are necessary to determine their clinical potential. We investigated the prognostic value of three Wnt signaling-associated proteins, β-catenin, E-cadherin, and SOX9, in a population-representative single-hospital series of 1290 Norwegian CRC patients by performing immunohistochemical analyses of each marker using the tissue microarray technology. Loss of membranous or cytosolic β-catenin and loss of cytosolic E-cadherin protein expression were significantly associated with reduced 5-year survival in 903 patients who underwent major resection (722 evaluable tissue cores) independently of standard clinicopathological high-risk parameters. Pre-specified subgroup analyses demonstrated particular effect for stage IV patients for β-catenin membrane staining (P = 0.018; formal interaction test P = 0.025). Among those who underwent complete resection (714 patients, 568 evaluable), 5-year time-to-recurrence analyses were performed, and stage II patients with loss of cytosolic E-cadherin were identified as an independent high-risk subgroup (P = 0.020, formal interaction test was not significant). Nuclear β-catenin and SOX9 protein, regardless of intracellular location, were not associated with prognosis. In conclusion, the protein expression level of membranous or cytosolic β-catenin and E-cadherin predicts CRC patient subgroups with inferior prognosis.

Prognostic Significance of β-Catenin, E-Cadherin, and SOX9 in Colorectal Cancer: Results from a Large Population-Representative Series

Robust biomarkers that can precisely stratify patients according to treatment needs are in great demand. The literature is inconclusive for most reported prognostic markers for colorectal cancer (CRC). Hence, adequately reported studies in large representative series are necessary to determine their clinical potential. We investigated the prognostic value of three Wnt signaling-associated proteins, β-catenin, E-cadherin, and SOX9, in a population-representative single-hospital series of 1290 Norwegian CRC patients by performing immunohistochemical analyses of each marker using the tissue microarray technology. Loss of membranous or cytosolic β-catenin and loss of cytosolic E-cadherin protein expression were significantly associated with reduced 5-year survival in 903 patients who underwent major resection (722 evaluable tissue cores) independently of standard clinicopathological high-risk parameters. Pre-specified subgroup analyses demonstrated particular effect for stage IV patients for β-catenin membrane staining (P = 0.018; formal interaction test P = 0.025). Among those who underwent complete resection (714 patients, 568 evaluable), 5-year time-to-recurrence analyses were performed, and stage II patients with loss of cytosolic E-cadherin were identified as an independent high-risk subgroup (P = 0.020, formal interaction test was not significant). Nuclear β-catenin and SOX9 protein, regardless of intracellular location, were not associated with prognosis. In conclusion, the protein expression level of membranous or cytosolic β-catenin and E-cadherin predicts CRC patient subgroups with inferior prognosis.

Chemoprevention of colon and small intestinal tumorigenesis in APC(min/+) mice by SHetA2 (NSC721689) without toxicity

The occurrence of intestinal polyps in people at high risk for developing colorectal cancer provides an opportunity to test the efficacy of chemoprevention agents. In this situation of treating otherwise healthy people, the potential for toxicity must be minimal. The small-molecule flexible heteroarotinoid (Flex-Het), called SHetA2, has chemoprevention activity in organotypic cultures in vitro and lack of toxicity at doses capable of inhibiting xenograft tumor growth in vivo. The objective of this study was to evaluate SHetA2 chemoprevention activity and toxicity in the APC(min/+) murine model. Oral administration of SHetA2 at 30 and 60 mg/kg five days per week for 12 weeks significantly reduced development of intestinal polyps by 40% to 60% depending on the dose and sex of the treatment group. Immunohistochemical and Western blot analysis of polyps showed reduced levels of cyclin D1 and proliferating cell nuclear antigen in both SHetA2 treatment groups. Western blot analysis also showed SHetA2 induction of E-cadherin, Bax, and caspase-3 cleavage along with reduction in Bcl-2, COX-2, and VEGF, consistent with SHetA2 regulation of apoptosis, inflammation, and angiogenesis. Neither dose caused weight loss nor gross toxicity in APC(min/+) or wild-type littermates. Magnetic resonance imaging (MRI) of cardiac function showed no evidence of SHetA2 toxicity. SHetA2 did not alter left ventricular wall thickness. In summary, SHetA2 exerts chemoprevention activity without overt or cardiac toxicity in the APC(min/+) model. SHetA2 modulation of biomarkers in colon polyps identifies potential pharmacodynamic endpoints for SHetA2 clinical trials.

Associations of beta-catenin alterations and MSI screening status with expression of key cell cycle regulating proteins and survival from colorectal cancer

Background

Despite their pivotal roles in colorectal carcinogenesis, the interrelationship and prognostic significance of beta-catenin alterations and microsatellite instability (MSI) in colorectal cancer (CRC) needs to be further clarified. In this paper, we studied the associations between beta-catenin overexpression and MSI status with survival from CRC, and with expression of p21, p27, cyclin D1 and p53, in a large, prospective cohort study.

Methods

Immunohistochemical MSI-screening status and expression of p21, p27 and p53 was assessed in tissue microarrays with tumours from 557 cases of incident CRC in the Malmö Diet and Cancer Study. Chi Square and Spearman’s correlation tests were used to explore the associations between beta-catenin expression, MSI status, clinicopathological characteristics and investigative parameters. Kaplan-Meier analysis and Cox proportional hazards modelling were used to assess the relationship between beta-catenin overexpression, MSI status and cancer specific survival (CSS).

Results

Positive MSI screening status was significantly associated with older age, female sex, proximal tumour location, non-metastatic disease, and poor differentiation, and inversely associated with beta-catenin overexpression. Beta-catenin overexpression was significantly associated with distal tumour location, low T-stage and well-differentiated tumours. Patients with MSI tumours had a significantly prolonged CSS in the whole cohort, and in stage III-IV disease, also in multivariable analysis, but not in stage I-II disease. Beta-catenin overexpression was associated with a favourable prognosis in the full cohort and in patients with stage III-IV disease. Neither MSI nor beta-catenin status were predictive for response to adjuvant chemotherapy in curatively treated stage III patients. P53 and p27 expression was positively associated with beta-catenin overexpression and inversely associated with MSI. Cyclin D1 expression was positively associated with MSI and beta-catenin overexpression, and p21 expression was positively associated with MSI but not beta-catenin overexpression.

Conclusions

Findings from this large, prospective cohort study demonstrate that MSI screening status in colorectal cancer is an independent prognostic factor, but not in localized disease, and does not predict response to adjuvant chemotherapy. Beta-catenin overexpression was also associated with favourable outcome but not a treatment predictive factor. Associations of MSI and beta-catenin alterations with other investigative and clinicopathological factors were in line with the expected.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8778585058652609

Wnt signalling in an in vitro niche model for conjunctival progenitor cells

Mimicking an environment in vitro that is more similar to the stem cell niche in vivo, by co-culture of mitotically active conjunctival fibroblasts (HCF) with human conjunctival epithelial cells (HCECs), improves the maintenance of epithelial cells with progenitor cell characteristics during in vitro expansion. However, little is known about the pathways controlling the fate of the epithelial progenitor cells during in vitro culture. In this study, differences in gene expression between this in vitro 'niche' model and standard culture conditions, in which growth-arrested 3 T3 feeder cells and fetal calf serum are used, were explored using a genome level microarray platform, quantitative (q)RT-PCR and western blot. The microarray analysis revealed significant alterations of biological processes involved in cell proliferation, differentiation and cell death. The analysis of stem cell-related pathways indicated changes in expression of genes involved in the Wnt signalling pathway, and further investigation by qPCR revealed significant downregulation of the Wnt ligands Wnt3, Wnt4, Wnt7B and Wnt10A, Wnt receptor proteins FZD1, LRP5, LRP6, ß-catenin and TCF7L1 and important Wnt target genes, such as CCND1, also confirmed by western blot and immunocytochemistry. The results indicate that epithelial cell expansion in the HCEC-HCF co-culture system is accompanied by significant changes in expression of genes involved in the Wnt signalling pathway. This altered pathway activation might be involved in the enhanced maintenance of epithelial progenitor cells in this in vitro 'niche' model.

The expression pattern of aldehyde dehydrogenase 1 (ALDH1) is an independent prognostic marker for low survival in colorectal tumors

BACKGROUND

Aldehyde dehydrogenase-1 (ALDH1) is involved in the regulation of cell proliferation and differentiation. Moreover, it is a marker for cancer stem cells (CSC). As CSCs were shown to be the driving force of tumor progression and metastases we suspected that the expression of ALDH1 correlated with the prognostic 5 year survival of colorectal cancer.

METHODS

ALDH1 expression was analyzed in a highly stratified collective of 186 T3 N0 M0 G2 primary colorectal cancer specimens applying immunohistochemistry. For the analysis a scoring system for the expression of ALDH1 was developed that was aided by the pattern of the subcellular expression of beta-catenin which is a well known indicator for colorectal CSCs.

RESULTS

First, ALDH1 expression could be assigned to two groups which correlated with the absence or presence of nuclear beta-catenin expression. Second, ALDH1 group 2 expression patterning correlated highly significantly with low long term survival (p=0.010) of patients with T3 N0 M0 G2 colorectal cancer. This correlation was found univariately and when applying the multivariate Cox-model.

CONCLUSION

ALDH1 expression pattern is an independent prognostic marker for survival of T3 N0 M0 G2 colorectal cancer patients.

Gastric tuft cells express DCLK1 and are expanded in hyperplasia

Epithelial tuft cells are named after their characteristic microtubule bundles located at the cell apex where these are exposed to the luminal environment. As such, tuft cells are found in multiple organs, including the gastrointestinal (GI) tract where the apical "tuft" is hypothesized to detect and transmit environmental signals. Thus, the goal of our study was to characterize gastric tuft cells during GI tract development, then subsequently in the normal and metaplastic adult stomach. GI tracts from mouse embryos, and newborn and postnatal mice were analyzed. Tuft cells were identified by immunohistochemistry using acetylated-α-tubulin (acTub) antibody to detect the microtubule bundle. Additional tuft cell markers, e.g., doublecortin-like kinase 1 (DCLK1), were used to co-localize with acTub. Tuft cells were quantified in human gastric tissue arrays and in mouse stomachs with or without inflammation. In the developing intestine, tuft cells in both the crypts and villi expressed all markers by E18.5. In the stomach, acTub co-localized with DCLK1 and other established tuft cell markers by E18.5 in the antrum, but not until postnatal day 7 in the corpus, with the highest density of tuft cells clustered at the forestomach ridge. Tuft cell numbers increased in hyperplastic human and mouse stomachs. In the adult GI tract, the tuft cell marker acTub co-expressed with DCKL1 and chemosensory markers, e.g.,TRPM5. In summary, tuft cells appear in the gastric antrum and intestine at E18.5, but their maximal numbers in the corpus are not achieved until after weaning. Tuft cell numbers increase with inflammation, hyperplasia, and metaplasia.

Association of CTNNB1 (beta-catenin) alterations, body mass index, and physical activity with survival in patients with colorectal cancer

CONTEXT

Alterations of the WNT signaling pathway and cadherin-associated protein β 1 (CTNNB1 or β-catenin) have been implicated in colorectal carcinogenesis and metabolic diseases.

OBJECTIVE

To test the hypothesis that CTNNB1 activation in colorectal cancer modifies prognostic associations of body mass index (BMI) and level of postdiagnosis physical activity.

DESIGN, SETTING, AND PATIENTS

Two US prospective cohort studies (Nurses' Health Study and the Health Professionals Follow-up Study) were used to evaluate CTNNB1 localization by immunohistochemistry in 955 patients with stage I, II, III, or IV colon and rectal cancer from 1980 through 2004. A Cox proportional hazards model was used to compute the hazard ratio (HR) for mortality, adjusting for clinical and tumor features, including microsatellite instability, CpG island methylator phenotype, level of long interspersed nucleotide element 1 methylation, mutations in KRAS, BRAF, or PIK3CA, and tumor protein p53.

MAIN OUTCOME MEASURES

Colorectal cancer-specific mortality and overall mortality through June 30, 2009.

RESULTS

In obese patients (BMI ≥30), positive status for nuclear CTNNB1 was associated with significantly better colorectal cancer-specific survival (adjusted HR, 0.24 [95% confidence interval {CI}, 0.12-0.49], P <.001 for interaction; 5-year survival: 0.85 for patients with positive nuclear CTNNB1 status vs 0.78 for those with negative status) and overall survival (adjusted HR, 0.56 [95% CI, 0.35-0.90], P = .03 for interaction; 5-year survival: 0.77 for patients with positive nuclear CTNNB1 status vs 0.74 for those with negative status), while CTNNB1 status was not associated with prognosis among nonobese patients (BMI <30). Among patients with negative status for nuclear CTNNB1 and cancer in stages I, II, or III, postdiagnosis physical activity was associated with better colorectal cancer-specific survival (adjusted HR, 0.33 [95% CI, 0.13-0.81], P = .05 for interaction; 5-year survival: 0.97 for ≥18 vs 0.89 for <18 metabolic equivalent task hours/week), while postdiagnosis physical activity was not associated with colorectal cancer-specific survival among patients with positive status for nuclear CTNNB1 (adjusted HR, 1.07 [95% CI, 0.50-2.30]).

CONCLUSIONS

Among obese patients only, activation of CTNNB1 was associated with better colorectal cancer-specific survival and overall survival. Postdiagnosis physical activity was associated with better colorectal cancer-specific survival only among patients with negative status for nuclear CTNNB1. These molecular pathological epidemiology findings suggest that the effects of alterations in the WNT-CTNNB1 pathway on outcome are modified by BMI and physical activity.

Prognostic relevance of β-catenin expression in T2-3N0M0 esophageal squamous cell carcinoma

AIM: To study the expression of β-catenin in esophageal squamous cell carcinoma (ESCC) at stage T2-3N0M0 and its relation with the prognosis of ESCC patients.

METHODS: Expression of β-catenin in 227 ESCC specimens was detected by immunohistochemistry (IHC). A reproducible semi-quantitative method which takes both staining percentage and intensity into account was applied in IHC scoring, and receiver operating characteristic curve analysis was used to select the cut-off score for high or low IHC reactivity. Then, correlation of β-catenin expression with clinicopathological features and prognosis of ESCC patients was determined.

RESULTS: No significant correlation was observed between β-catenin expression and clinicopathological parameters in terms of gender, age, tumor size, tumor grade, tumor location, depth of invasion and pathological stage. The Kaplan-Meier survival curve showed that the up-regulated expression of β-catenin indicated a poorer post-operative survival rate of ESCC patients at stage T2-3N0M0 (P = 0.004), especially of those with T3 lesions (P = 0.014) or with stage IIB diseases (P = 0.007). Multivariate analysis also confirmed that β-catenin was an independent prognostic factor for the overall survival rate of ESCC patients at stage T2-3N0M0 (relative risk = 1.642, 95% CI: 1.159-2.327, P = 0.005).

CONCLUSION: Elevated β-catenin expression level may be an adverse indicator for the prognosis of ESCC patients at stage T2-3N0M0, especially for those with T3 lesions or stage IIB diseases.