Prognostic value of nuclear β-catenin overexpression at invasive front in colorectal cancer for synchronous liver metastasis

Angiogenesis-Related Functions of Wnt Signaling in Colorectal Carcinogenesis

Simple Summary

Angiogenesis belongs to the most clinical characteristics of colorectal cancer (CRC) and is strongly linked to the activation of Wnt/β-catenin signaling. The most prominent factors stimulating constitutive activation of this pathway, and in consequence angiogenesis, are genetic alterations (mainly mutations) concerning APC and the β-catenin encoding gene (CTNNB1), detected in a large majority of CRC patients. Wnt/β-catenin signaling is involved in the basic types of vascularization (sprouting and nonsprouting angiogenesis), vasculogenic mimicry as well as the formation of mosaic vessels. The number of known Wnt/β-catenin signaling components and other pathways interacting with Wnt signaling, regulating angiogenesis, and enabling CRC progression continuously increases. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

Abstract

Aberrant activation of the Wnt/Fzd/β-catenin signaling pathway is one of the major molecular mechanisms of colorectal cancer (CRC) development and progression. On the other hand, one of the most common clinical CRC characteristics include high levels of angiogenesis, which is a key event in cancer cell dissemination and distant metastasis. The canonical Wnt/β-catenin downstream signaling regulates the most important pro-angiogenic molecules including vascular endothelial growth factor (VEGF) family members, matrix metalloproteinases (MMPs), and chemokines. Furthermore, mutations of the β-catenin gene associated with nuclear localization of the protein have been mainly detected in microsatellite unstable CRC. Elevated nuclear β-catenin increases the expression of many genes involved in tumor angiogenesis. Factors regulating angiogenesis with the participation of Wnt/β-catenin signaling include different groups of biologically active molecules including Wnt pathway components (e.g., Wnt2, DKK, BCL9 proteins), and non-Wnt pathway factors (e.g., chemoattractant cytokines, enzymatic proteins, and bioactive compounds of plants). Several lines of evidence argue for the use of angiogenesis inhibition in the treatment of CRC. In the context of this paper, components of the Wnt pathway are among the most promising targets for CRC therapy. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

Markers of Cancer Cell Invasion: Are They Good Enough?

Invasion, or directed migration of tumor cells into adjacent tissues, is one of the hallmarks of cancer and the first step towards metastasis. Penetrating to adjacent tissues, tumor cells form the so-called invasive front/edge. The cellular plasticity afforded by different kinds of phenotypic transitions (epithelial-mesenchymal, collective-amoeboid, mesenchymal-amoeboid, and vice versa) significantly contributes to the diversity of cancer cell invasion patterns and mechanisms. Nevertheless, despite the advances in the understanding of invasion, it is problematic to identify tumor cells with the motile phenotype in cancer tissue specimens due to the absence of reliable and acceptable molecular markers. In this review, we summarize the current information about molecules such as extracellular matrix components, factors of epithelial-mesenchymal transition, proteases, cell adhesion, and actin cytoskeleton proteins involved in cell migration and invasion that could be used as invasive markers and discuss their advantages and limitations. Based on the reviewed data, we conclude that future studies focused on the identification of specific invasive markers should use new models one of which may be the intratumor morphological heterogeneity in breast cancer reflecting different patterns of cancer cell invasion.

Molecular and Immunohistochemical Markers with Prognostic and Predictive Significance in Liver Metastases from Colorectal Carcinoma

Despite the significant recent achievements in the diagnosis and treatment of colorectal cancer (CRC), the prognosis of these patients has currently plateaued. During the past few years, the opportunity to consider multiple treatment modalities (including surgery and other locoregional treatments, systemic therapy, and targeted therapy) led to the research of novel prognostic and predictive biomarkers in CRC liver metastases (CRCLM) patients. In this review, we seek to describe the current state of knowledge of CRCLM biomarkers and to outline impending clinical perspectives, in particular focusing on the cutting-edge tools available for their characterization.

Expression of the Hepatocyte Growth Factor and C-Met in Colon Cancer: Correlation with Clinicopathological Features and Overall Survival

Aim and Background

The hepatocyte growth factor (HGF)/c-Met signaling system has been implicated in the development and progression of colon cancer, but the relationship between the expression of HGF or c-MET and clinicopathologic features remains controversial. In the study, we analyzed the expression of HGF and c-Met in colon cancer and assessed the influence of the expression of this growth factor and its receptor on clinical and histological parameters and patient survival.

Methods and Study Design

We investigated the mRNA expression of HGF and c-Met with real-time PCR in 90 unselected colon carcinomas and the corresponding normal mucosa. Furthermore, HGF and c-Met protein expression was investigated with immunohistochemistry in all the samples.

Results

The mRNA and protein expression levels of HGF and c-Met were significantly higher in colon cancer than in matched normal mucosa. The protein level in most of the cases investigated was correlated with the mRNA level. Overexpression of HGF and c-Met, at both protein and mRNA levels, was correlated with depth of invasion, lymph node metastases and overall AJCC stage. According to univariate analysis, the mean survival time was shorter in the HGF-positive and c-Met-positive groups. Multivariate Cox analysis showed that high M stage and the expression of c-Met independently had a negative impact on overall survival.

Conclusions

The HGF/c-Met signaling pathway may be involved in the pathogenesis and progression of colon cancer. C-Met overexpression can be used as a useful parameter to evaluate the prognosis of colon cancer.

Hormophysa triquerta polyphenol, an elixir that deters CXCR4- and COX2-dependent dissemination destiny of treatment-resistant pancreatic cancer cells

Therapy-resistant pancreatic cancer (PC) cells play a crucial role in tumor relapse, recurrence, and metastasis. Recently, we showed the anti-PC potential of an array of seaweed polyphenols and identified efficient drug deliverables. Herein, we investigated the benefit of one such deliverable, Hormophysa triquerta polyphenol (HT-EA), in regulating the dissemination physiognomy of therapy-resistant PC cells in vitro,and residual PC in vivo. Human PC cells exposed to ionizing radiation (IR), with/without HT-EA pre-treatment were examined for the alterations in the tumor invasion/metastasis (TIM) transcriptome (93 genes, QPCR-profiling). Utilizing a mouse model of residual PC, we investigated the benefit of HT-EA in the translation regulation of crucial TIM targets (TMA-IHC). Radiation activated 30, 50, 15, and 38 TIM molecules in surviving Panc-1, Panc-3.27, BxPC3, and MiaPaCa-2 cells. Of these, 15, 44, 12, and 26 molecules were suppressed with HT-EA pre-treatment. CXCR4 and COX2 exhibited cell-line-independent increases after IR, and was completely suppressed with HT-EA, across all PC cells. HT-EA treatment resulted in translational repression of IR-induced CXCR4, COX2, β-catenin, MMP9, Ki-67, BAPX, PhPT-1, MEGF10, and GRB10 in residual PC. Muting CXCR4 or COX2 regulated the migration/invasion potential of IR-surviving cells, while forced expression of CXCR4 or COX2 significantly increased migration/invasion capabilities of PC cells. Further, treatment with HT-EA significantly inhibited IR-induced and CXCR4/COX2 forced expression-induced PC cell migration/invasion. This study (i) documents the TIM blueprint in therapy-resistant PC cells, (ii) defines the role of CXCR4 and COX2 in induced metastatic potential, and (iii) recognizes the potential of HT-EA in deterring the CXCR4/COX2-dependent dissemination destiny of therapy-resistant residual PC cells.

[Impact of preoperative drug therapy on adhesion molecule expression in colorectal cancer liver metastases]

OBJECTIVE

To study E-cadherin and β-catenin expression in colorectal cancer (CRC) liver metastases in order to assess the impact of different drug therapy regimens on the adhesive properties of tumor cells.

MATERIAL AND METHODS

Intraoperative metastatic CRC samples from patients who had received preoperative cytotoxic chemotherapy or combined cytotoxic and targeted anti-VEGF (vascular endothelial growth factor) therapy were immunohistochemically examined using antibodies to E-cadherin and β-catenin. A comparison group consisted of patients who had not received drug therapy.

RESULTS

Combined therapy with cytotoxic and anti-VEGF agents was shown to result in a significant increase in the number of cases of normal membrane localization of E-cadherin as compared with control (p = 0.00043) and cytotoxic therapy-alone (p = 0.01) groups. A comparison of β-catenin levels in three patient groups revealed no significant differences, but addition of an anti-VEGF agent caused some decrease in the number of cases of abnormal nuclear localization of the protein as compared to both the control group and the cytotoxic therapy groups. The comparison of E-cadherin and β-catenin localization in tumor cells showed that a combination of normal E-cadherin membrane localization and β-catenin membrane-cytoplasmic expression prevailed in the combined therapy group compared to the control (p = 0.009) and cytotoxic therapy (p = 0.04) groups.

CONCLUSION

The addition of a targeted anti-VEGF agent to the drug therapy of metastatic CRC has a positive impact on the cadherin-catenin complex, leading to increased intercellular contacts and suppressed β-catenin functioning as a transcription factor that enhances tumor cell proliferation.

Aberrant CXCR4 and β-catenin expression in osteosarcoma correlates with patient survival

To determine the clinical significance of C-X-C chemokine receptor type 4 (CXCR4) and β-catenin in osteosarcoma, their protein expression levels were assessed in 96 osteosarcoma and 20 osteochondroma cases using immunohistochemistry. Additionally, CXCR4 and β-catenin mRNA expression levels were measured in 16 fresh osteosarcoma and 16 adjacent healthy tissue samples using fluorescent reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In the osteosarcoma samples, the positive CXCR4 protein expression rate was significantly higher than the rate in the osteochondroma samples (68.75 vs. 20.00%; P<0.01). Furthermore, β-catenin protein expression was detected in 61.46% of osteosarcoma cases and 25.00% of osteochondroma cases. Similarly, the RT-qPCR data identified increased CXCR4 and β-catenin mRNA expression levels in the osteosarcoma compared with adjacent control tissues. It was determined that CXCR4 (P<0.01) and β-catenin (P<0.05) expression were significantly associated with the clinical Enneking stage, metastasis and survival of osteosarcoma. Furthermore, multivariate analysis identified CXCR4 and β-catenin protein expression levels, as well as clinical stage and metastasis, as significant risk factors for survival in patients with osteosarcoma (P<0.05). In conclusion, the present study determined that CXCR4 and β-catenin are abnormally expressed in osteosarcoma tissues, and, therefore, may be important during osteosarcoma progression.

Expression and mutation pattern of β-catenin and adenomatous polyposis coli in colorectal cancer patients

BACKGROUND AND AIMS

β-Catenin and adenomatous polyposis coli (APC) are major components of the Wnt pathway. This study aimed to investigate the expression of β-catenin and APC in tumors and lymph nodes in colorectal cancer (CRC) patients and the mutational spectrum of the genes coding these proteins.

METHODS

Expression of APC and β-catenin was examined in 124 tumors and 41 lymph nodes. Exon 3 of CTNNB1 and the mutation cluster region (MCR) in exon 15 of the APC gene were screened for mutation by PCR-sequencing.

RESULTS

Nuclear/cytoplasmic immunostaining of β-catenin was detected in 58.1 and 48.8% in tumors and lymph nodes, respectively. In tumors, abnormal expression of β-catenin correlated with tumor size and with those in lymph nodes. Membranous β-catenin expression occurred in 41.9 and 14.6% of tumors and lymph nodes, respectively. In tumors, lack of membranous β-catenin correlated with high invasiveness and metastatic potential. Positive immunostaining for APC was observed in 2 and 14% of tumors and lymph nodes, respectively. Overexpression in nucleus/cytoplasm and lack of membranous β-catenin significantly correlated with a reduced overall survival. Among 25 tumors, four harbour mutation in Ser33 and Ser47 and overexpress the β-catenin in the nucleus/cytoplasm. Mutations were identified in the APC gene in 13 tumors and six mutations were novel.

CONCLUSIONS

Positive association between aberrant expression of β-catenin in the nucleus/cytoplasm of tumors and lymph nodes was observed. Nucleus/cytoplasmic accumulation of β-catenin and loss of membranous expression are related to reduced survival and could serve as a candidate prognostic predictor.

Weichang’an and 5-fluorouracil suppresses colorectal cancer in a mouse model

AIM: To examine the effect of Weichang’an (WCA) and 5-fluorouracil (5-FU) on colorectal tumor and hepatic metastasis in a mouse model.

METHODS: Quantitative determination of hesperidin, the effective component in WCA decoction, was performed using HPLC. In vitro cytotoxicity of WCA was determined by treating HCT-116 cells with WCA diluents or serum extracted from rats that received WCA by oral gavage for 1 wk and MTT assays. Forty-eight nude mice received cecum implantation with tumor blocks subcutaneously amplified from human colon cancer cell line HCT-116. Mice were randomly divided into four treatment groups: control (CON), WCA, 5-FU and combination (WCA + 5-FU). Pathological examination of tumors consisted of tissue sectioning and hematoxylin and eosin staining. Tumor weight and size were measured, and the number of metastatic lesions was counted. Serum carcinoembryonic antigen (CEA) level was determined by ELISA. The expression levels of tumor genesis and metastasis-related proteins β-catenin and matrix metalloproteinase (MMP)-7 were measured by real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR), immunohistochemistry and immunoblotting. Cell fractionation was used to investigate intracellular distribution of β-catenin.

RESULTS: Parenchymal tumors were palpable in the abdomens of nude mice 2 wk post-implantation and orthotopic tumor formation rate was 100% in all groups. 5-FU treatment alone significantly decreased tumor weight compared to the CON group (1.203 ± 0.284 g vs 1.804 ± 0.649 g, P < 0.01). WCA treatment alone reduced the rate of metastasis (50% vs 100%, P < 0.05). Combination treatment of WCA + 5-FU was the most effective, reducing the tumor weight (1.140 ± 0.464 g vs 1.804 ± 0.649 g, P < 0.01) and size (1493.438 ± 740.906 mm³vs 2180.259 ± 816.556 mm³, P < 0.05), the rate of metastases (40% vs 100%, P < 0.01), and serum CEA levels (31.263 ± 7.421 μg/L vs 43.040 ± 11.273 μg/L, P < 0.05). Expression of β-catenin and MMP-7 was decreased in drug-treated groups compared to controls, as detected using real-time quantitative RT-PCR, immunohistochemistry and immunoblotting, respectively. Cell fractionation assays revealed that nuclear translocation of β-catenin was reduced by WCA and/or 5-FU treatments.

CONCLUSION: Combination of WCA with 5-FU significantly inhibited colon tumor growth and hepatic metastases. Decreased expression of β-catenin and MMP-7 may be important.

Immunohistochemical demonstration of alteration of β-catenin during tumor metastasis by different mechanisms according to histology in lung cancer

The protein β-catenin exhibits a dual function in cells, by acting as a major structural component of cell-cell adherens junctions and as a central signaling molecule in the Wnt signaling pathway. However, how the regulation of β-catenin expression during tumor metastasis in non-small cell lung cancer (NSCLC) varies according to histological type remains unclear. To investigate the regulatory mechanism of β-catenin on tumor metastasis, the present study compared the expression of Wnt1, β-catenin and E-cadherin in 41 primary NSCLC tumors and their corresponding metastatic lesions by immunohistochemistry. Altered expression of β-catenin was more frequent in the metastatic tumors (34/41, 82.9%) than in the corresponding primary tumors (24/41, 58.5%; P<0.05). There were 12 cases [nine of adenocarcinoma (ADC) and three of squamous cell carcinoma (SqCC)] that revealed discordant β-catenin expression between the primary tumors and the corresponding metastatic lesions. Of these, 11 cases (11/12, 91.7%; nine ADCs and two SqCCs) demonstrated acquired β-catenin alterations in the metastatic lesions. Subgroup analysis of these nine ADCs revealed that six cases (6/9, 66.7%) were accompanied by E-cadherin loss but no Wnt1 overexpression. Subgroup analysis of the three SqCCs revealed discordant β-catenin expression. Two cases (2/3, 66.7%) demonstrated acquired β-catenin expression during metastatic progression with Wnt1 overexpression but no change in E-cadherin expression. One case of SqCC revealed normal β-catenin expression in the metastasis although the expression was aberrant in the primary tumor. The results of the present study revealed that the changes in β-catenin expression occurred during tumor metastasis by different mechanisms, depending on histological type. The alterations in β-catenin expression may be regulated by a cadherin-catenin system in ADCs with reduced membranous expression of E-cadherin, but mediated by Wnt1 overexpression in SqCCs with cytoplasmic or nuclear transition types.

Cancer stem cell characteristics, ALDH1 expression in the invasive front of nasopharyngeal carcinoma

The invasive tumor front underlies the biological aggressiveness and epithelial-mesenchymal transition (EMT) in various human malignances. However, the molecular and biological characteristics of invasive tumor front in NPC have rarely been described. Additionally, the features of cancer stem cells (CSCs) in the invasive front of tumors and its correlation with EMT also remain elusive. Our study was to investigate the expression of CSCs marker aldehyde dehydrogenase 1 (ALDH1) in the invasive front of nasopharyngeal carcinoma (NPC) and its clinical significance. Immunohistochemistry was mainly used to detect ALDH1 expression in the invasive front of NPC. The relationship between ALDH1 expression and EMT-associated markers was also examined. ALDH1 expression in the invasive front correlated strongly with lymphatic invasion (p<0.001), T classification (p=0.001), M classification (p<0.001), clinical stage (p<0.001), and local recurrence (p=0.008). ALDH1 overexpression in the invasive front contributed to worse survival of NPC, particularly in patients with early stage (T1-T2 or N0-N1) (p<0.001 and p=0.002, respectively), though it was not an independent prognostic factor (p=0.196). Furthermore, in the invasive front of NPC, ALDH1 expression correlated significantly with EMT-related biomarkers E-cadherin (p=0.026), Vimentin (p<0.001), Periostin (p<0.001), and Snail (p<0.001), but not with β-catenin (p=0.143). Our findings demonstrate first that ALDH1 expression in the invasive front links closely with EMT characteristics and tumor aggressiveness, which might provide a useful prognostic marker for NPC patients.

New insight into Ki67 expression at the invasive front in breast cancer

Purpose

To investigate the distribution of Ki67+ cells in breast cancer in relation to clinical-pathological parameters and prognosis.

Materials and Methods

Ki67 expression status was detected in 1,086 breast cancer specimens using immunohistochemistry staining and examining the relationship between the Ki67+ cells' location. Subsequently, clinical-pathological parameters and prognosis were determined.

Results

In total, Ki67 protein expression was found in 781 (71.92%) of the 1,086 breast cancer specimens. Among the 781 Ki67+ cases, 461 were defined as diffuse type and 320 were defined as borderline type. After universal correlation analysis, significant differences were observed in age, histological grade, metastatic nodes, postoperative distant metastasis, and molecular subtype between Ki67+ and Ki67− cases (P = 0.01, 0.001, 0.001, 0.001, and 0.001, respectively). After subgroup analysis, the borderline cases were found to be characterized by a high distant metastasis rate compared to the diffuse cases as well as the Ki67− cases (P = 0.001). No differences were observed between diffuse type or Ki67− cases (P = 0.105). Multivariate analysis showed that age, tumor size, histological grade, lymph node metastasis, molecular subtype, and the Ki67 distribution pattern were observed to be related to postoperative distant metastasis (all P<0.05). Furthermore, borderline type was shown to attain a significantly more distant bone and liver metastasis and worse disease-specific survival than the other types (P = 0.001). In the Cox regression test, the Ki67 distribution pattern was detected as an independent prognostic factor (P = 0.001).

Conclusion

The distribution pattern of Ki67 may be a new independent prognostic factor for breast cancer.

Ursolic acid inhibits growth and metastasis of human colorectal cancer in an orthotopic nude mouse model by targeting multiple cell signaling pathways: chemosensitization with capecitabine

PURPOSE

Development of chemoresistance, poor prognosis, and metastasis often renders the current treatments for colorectal cancer (CRC) ineffective. Whether ursolic acid, a component of numerous medicinal plants, either alone or in combination with capecitabine, can inhibit the growth and metastasis of human CRC was investigated.

EXPERIMENTAL DESIGN

The effect of ursolic acid on proliferation of CRC cell lines was examined by mitochondrial dye uptake assay, apoptosis by esterase staining, NF-κB activation by DNA-binding assay, and protein expression by Western blot. The effect of ursolic acid on the growth and chemosensitization was also examined in orthotopically implanted CRC in nude mice.

RESULTS

We found that ursolic acid inhibited the proliferation of different colon cancer cell lines. This is correlated with inhibition of constitutive NF-κB activation and downregulation of cell survival (Bcl-xL, Bcl-2, cFLIP, and survivin), proliferative (cyclin D1), and metastatic (MMP-9, VEGF, and ICAM-1) proteins. When examined in an orthotopic nude mouse model, ursolic acid significantly inhibited tumor volume, ascites formation, and distant organ metastasis, and this effect was enhanced with capecitabine. Immunohistochemistry of tumor tissue indicated that ursolic acid downregulated biomarkers of proliferation (Ki-67) and microvessel density (CD31). This effect was accompanied by suppression of NF-κB, STAT3, and β-catenin. In addition, ursolic acid suppressed EGF receptor (EGFR) and induced p53 and p21 expression. We also observed bioavailability of ursolic acid in the serum and tissue of animals.

CONCLUSION

Overall, our results show that ursolic acid can inhibit the growth and metastasis of CRC and further enhance the therapeutic effects of capecitabine through the suppression of multiple biomarkers linked to inflammation, proliferation, invasion, angiogenesis, and metastasis.

Wnt/beta-catenin signaling in glioma

Extensive data have shown that Wnt/beta-catenin signaling is associated with various disease pathologies, including an important role in tumorigenesis. Here, we review the regulation of Wnt/beta-catenin signaling in glioma, with particular focus on the expression signatures of the main components in Wnt/beta-catenin signaling, the role of key factors in Wnt/beta-catenin signaling, and crosstalk with other signaling pathways. Finally, we discuss the involvement of microRNAs in Wnt/beta-catenin signaling in glioma. This review reveals new insights into the role of Wnt/beta-catenin signaling in gliomagenesis, and highlights new therapeutic approaches for glioma, based on the modulation of the Wnt/beta-catenin pathway.