Nuclear expression of glycogen synthase kinase-3β and lack of membranous β-catenin is correlated with poor survival in colon cancer

Identification and validation of metastasis-related gene ZG16 in the prognosis and progression in colorectal cancer

Background

Metastasis remains the leading cause of mortality among colorectal cancer (CRC) patients. Identification of new metastasis-related genes are critical to improve colorectal cancer prognosis.

Methods

Data on mRNA expression in metastatic and primary CRC was obtained from the Gene Expression Omnibus (GEO) database, including GSE81986, GSE41568, GSE71222, GSE21510, and GSE14333. Additionally, data concerning mRNA expression in colon cancer (COAD) and adjacent normal tissues were acquired from The Cancer Genome Atlas (TCGA) database. Hub genes were identified by weighted gene co-expression network analysis (WGCNA) and differential gene expression analysis. Moreover, we assessed the impact of hub gene expression on both overall survival (OS) and disease-free survival (DFS) in patients and identified ZG16 as a potential target. We generated CRC cell lines transfected with lentivirus OE-ZG16 to investigate proliferation, invasion, and migration in vitro. To further elucidate the involvement of ZG16, we utilized gene set enrichment analysis (GSEA) to identify enriched pathways, which were subsequently validated via Western blot analysis.

Results

Five datasets containing primary and metastatic CRC samples from GEO database and CRC samples from TCGA database were included in this study and 29 hub genes were identified by WGCNA and differentially expressed gene (DEG) analysis. Low expression of the hub genes (CLCA1 and ZG16) was associated with poor DFS and OS. We confirmed the low expression of ZG16 in CRC using external database and IHC analysis at both transcriptional and protein levels. In addition, the expression of ZG16 was notably elevated in NCM460 cells in comparison to CRC cell lines. The overexpression of ZG16 in CRC cells has been shown to inhibit the proliferation, invasion, and migration of CRC cells. Furthermore, the overexpression of ZG16 has been found to suppress the activation of the epithelial-mesenchymal transition (EMT) and Wnt/β-catenin signaling pathways in CRC.

Conclusion

ZG16 may serve as a promising therapeutic target for metastatic CRC treatment.

Concurrent targeting of GSK3 and MEK as a therapeutic strategy to treat pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide. However, drug discovery for PDAC treatment has proven complicated, leading to stagnant therapeutic outcomes. Here, we identify Glycogen synthase kinase 3 (GSK3) as a therapeutic target through a whole-body genetic screening utilizing a '4-hit' Drosophila model mimicking the PDAC genotype. Reducing the gene dosage of GSK3 in a whole-body manner or knocking down GSK3 specifically in transformed cells suppressed 4-hit fly lethality, similar to Mitogen-activated protein kinase kinase (MEK), the therapeutic target in PDAC we have recently reported. Consistently, a combination of the GSK3 inhibitor CHIR99021 and the MEK inhibitor trametinib suppressed the phosphorylation of Polo-like kinase 1 (PLK1) as well as the growth of orthotopic human PDAC xenografts in mice. Additionally, reducing PLK1 genetically in 4-hit flies rescued their lethality. Our results reveal a therapeutic vulnerability in PDAC that offers a treatment opportunity for patients by inhibiting multiple targets.

Association of β-Catenin, APC, SMAD3/4, Tp53, and Cyclin D1 Genes in Colorectal Cancer: A Systematic Review and Meta-Analysis

Objectives

Accumulating evidence indicates that the expression and/or variants of several genes play an essential role in the progress of colorectal cancer (CRC). The current study is a meta-analysis undertaken to estimate the prognosis and survival associated with CTNNB1/β-catenin, APC, Wnt, SMAD3/4, TP53, and Cyclin D1 genes among CRC patients.

Methods

The authors searched PubMed, EMBASE, and Science Direct for relevant reports published between 2000 and 2020 and analyzed them to determine any relationship between the (immunohistochemically/sequencing-detected) gene expression and variants of the selected genes and the survival of CRC patients.

Results

The analysis included 34,074 patients from 64 studies. To evaluate association, hazard ratios (HRs) were estimated for overall survival (OS) or disease-free survival (DFS), with a 95% confidence interval (CIs). Pooled results showed that β-catenin overexpression, APC mutation, SMAD-3 or 4 loss of expression, TP53 mutations, and Cyclin D1 expression were associated with shorter OS. β-Catenin overexpression (HR: 0.137 (95% CI: 0.131–0.406)), loss of expression of SMAD3 or 4 (HR: 0.449 (95% CI: 0.146–0.753)), the mutations of TP53 (HR: 0.179 (95% CI: 0.126–0.485)), and Cyclin D1 expression (HR: 0.485 (95% CI: 0.772–0.198)) also presented risk for shorter DFS.

Conclusions

The present meta-analysis indicates that overexpression or underexpression and variants of CTNNB1/β-catenin, APC, SMAD3/4, TP53, and Cyclin D1 genes potentially acted as unfavorable biomarkers for the prognosis of CRC. The Wnt gene was not associated with prognosis.

Essential role of aerobic glycolysis in epithelial-to-mesenchymal transition during carcinogenesis

Epithelial-to-mesenchymal transition (EMT) confers the most lethal characteristics to cancer cells i.e., metastasis and resistance to chemo-and-radio-therapy, and therefore exhibit an appealing target in the field of oncology. Research in the past decade has demonstrated the crucial role of aerobic glycolysis in EMT, which is generally credited as the glucose metabolism for the creation of biomass such as fatty acids, amino acids, and nucleotides thereby providing building blocks for limitless proliferation. In the present review, apart from discussing EMT's evident role in the metastatic process and cancer stemness, we also talked about the vital role of glycolytic enzymes viz. GLUTs, HKs, PGI, PFK-1, aldolase, enolase, PK, LDHA, etc. in the induction of the EMT process in cancerous cells.

Nobiletin Induces Ferroptosis in Human Skin Melanoma Cells Through the GSK3β-Mediated Keap1/Nrf2/HO-1 Signalling Pathway

Melanoma is an aggressive malignant skin tumour with an increasing global incidence. However, current treatments have limitations owing to the acquired tumour drug resistance. Ferroptosis is a recently discovered form of programmed cell death characterised by iron accumulation and lipid peroxidation and plays a critical role in tumour growth inhibition. Recently, ferroptosis inducers have been regarded as a promising therapeutic strategy to overcome apoptosis resistance in tumour cells. In this study, we reported that nobiletin, a natural product isolated from citrus peel, and exhibited antitumour activity by inducing ferroptosis in melanoma cells. Subsequently, we further explored the potential mechanism of nobiletin-induced ferroptosis, and found that the expression level of glycogen synthase kinase 3β (GSK3β) in the skin tissue of patients with melanoma was significantly reduced compared to that in the skin of normal tissue. Additionally, nobiletin increased GSK3β expression in melanoma cells. Moreover, the level of Kelch-like Ech-associated protein-1 (Keap1) was increased, while the level of nuclear factor erythroid 2-related factor 2 (Nrf2), and haem oxygenase-1 (HO-1) was decreased in nobiletin-treated melanoma cells, suggesting that the antioxidant defence system was downregulated. Furthermore, knockdown of GSK3β significantly reduced nobiletin-induced ferroptosis and upregulated the Keap1/Nrf2/HO-1 signalling pathway, while the opposite was observed in cells overexpressing GSK3β. In addition, molecular docking assay results indicated that nobiletin showed strong binding affinities for GSK3β, Keap1, Nrf2, and HO-1. Taken together, our results demonstrated that nobiletin could induce ferroptosis by regulating the GSK3β-mediated Keap1/Nrf2/HO-1 signalling pathway in human melanoma cells. Hence, nobiletin stands as a promising drug candidate for melanoma treatment with development prospects.

Genistein suppresses the inflammation and GSK-3 pathway in an animal model of spontaneous ovarian cancer

Background/aim

Numerous studies show that cancer risk is reduced by consumption of soy-based foods containing genistein, but its effects on the glycogen synthase kinase-3 pathway (GSK-3) in ovarian cancer is unknown. Therefore, we tested the properties of genistein on inflammatory biomarkers and GSK-3 signaling pathways in the ovaries of old laying hens with ovarian cancer.

Materials and methods

A total of 300 laying hens were distributed into three groups as follows: group 1, animals fed a standard diet (comprising 22.39 mg of genistein/kg of diet); groups 2 and 3, animals fed a standard diet reconstituted with supplementation of 400 mg or 800 mg of genistein/kg of diet, respectively.

Results

Genistein modulated the inflammatory biomarkers by decreasing serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) compared with control (p < 0.001). Moreover, it upregulated insulin receptor substrate-1 (p-IRS-1) and protein kinase B (p-AKT), but downregulated GSK-3α and β after treatment. It acts in a dose-dependent manner.

Conclusion

Genistein exhibited an anticancer effect by reducing proinflammatory biomarkers levels and inhibiting GSK-3 expression in the ovaries of old laying hens. It is a potential candidate in the chemoprevention and/or treatment of ovarian cancer.

Scutellarin ameliorates colitis-associated colorectal cancer by suppressing Wnt/β-catenin signaling cascade

Dysregulated Wnt/β-catenin signaling pathway plays a critical role in the pathogenesis of colorectal cancer (CRC). Scutellarin, a flavonoid compound in Scutellaria barbata, has been reported to suppress CRC, with the action mechanism elusive. In this study, Scutellarin was found to inhibit the carcinogenesis of colitis-associated cancer (CAC) in mice caused by azoxymethane/dextran sulfate sodium, with alleviation of pathologic symptoms. Besides, Scutellarin attenuated mouse serum concentrations of TNF-α and IL-6, heightened Bax expression and diminished B-cell lymphoma-2 (Bcl-2) level in CAC tissues of mice, through down-regulating Wnt/β-catenin signaling cascade. In CRC HT-29 cells, Scutellarin retarded the proliferation and migration, induced apoptosis, with boosted Bax expression and decreased Bcl-2 level, which may be attributed to its repression of Wnt/β-catenin signals in HT-29 cells. Our findings demonstrate that Scutellarin may ameliorate colitis-associated colorectal cancer by weakening Wnt/β-catenin signaling cascade.

Characterisation of resistance mechanisms developed by basal cell carcinoma cells in response to repeated cycles of Photodynamic Therapy

Photodynamic Therapy (PDT) with methyl-aminolevulinate acid (MAL-PDT) is being used for the treatment of Basal cell carcinoma (BCC), but recurrences have been reported. In this work, we have evaluated resistance mechanisms to MAL-PDT developed by three BCC cell lines (ASZ, BSZ and CSZ), derived from mice on a ptch+/- background and with or without p53 expression, subjected to 10 cycles of PDT (10thG). The resistant populations showed mesenchymal-like structure and diminished proliferative capacity and size compared to the parental (P) cells. The resistance was dependent on the production of the endogenous photosensitiser protoporphyrin IX in the CSZ cell line and on its cellular localisation in ASZ and BSZ cells. Moreover, resistant cells expressing the p53 gene presented lower proliferation rate and increased expression levels of N-cadherin and Gsk3β (a component of the Wnt/β-catenin pathway) than P cells. In contrast, 10thG cells lacking the p53 gene showed lower levels of expression of Gsk3β in the cytoplasm and of E-cadherin and β-catenin in the membrane. In addition, resistant cells presented higher tumorigenic ability in immunosuppressed mice. Altogether, these results shed light on resistance mechanisms of BCC to PDT and may help to improve the use of this therapeutic approach.

A novel tumor-based epithelial-to-mesenchymal transition score that associates with prognosis and metastasis in patients with Stage II/III colorectal cancer

It is increasingly appreciated that host factors within the tumor center and microenvironment play a key role in dictating colorectal cancer (CRC) outcomes. As a result, the metastatic process has now been defined as a result of epithelial-mesenchymal transition (EMT). Establishment of the role of EMT within the tumor center and its effect on the tumor microenvironment would be beneficial for prognosis and therapeutic intervention in CRC. The present study assessed five immunohistochemical EMT markers within the tumor center on a 185 Stage II/III CRC patient tissue microarray. In 185 patients with CRC, cytoplasmic snail (HR 1.94 95% confidence interval [CI] 1.15-3.29, p = 0.012) and a novel combined EMT score (HR 3.86 95% CI 2.17-6.86, p < 0.001) were associated with decreased cancer-specific survival. The combined EMT score was also associated with increased tumor budding (p = 0.046), and systemic inflammation (p = 0.007), as well as decreased memory T-cells within the stroma (p = 0.030) and at the invasive margin (p = 0.035). Furthermore, the combined EMT score was associated with cancer-specific survival independent of TNM-stage (HR 4.12 95% CI 2.30-7.39, p < 0.001). In conclusion, a novel combined EMT score stratifies patient's survival in Stage II/III CRC and associates with key factors of tumor metastasis. Therefore, the combined EMT score could be used to identify patients at risk of micrometastases and who may benefit from standard adjuvant therapy, potentially in combination with EMT blockade.

Aberrant expression of glycogen synthase kinase-3β in human breast and head and neck cancer

Glycogen Synthase Kinase-3β (GSK-3β), a serine/threonine protein kinase, has been implicated as a potential therapeutic target in human cancer. The objective of the present study was to evaluate aberrant expression of GSK-3β as a potential biomarker in human breast and head and neck cancers. Nuclear/cytosolic fractionation, immunoblotting and immunohistochemical staining was used to study the expression of GSK-3β in human breast and head and neck cancer. Aberrant nuclear accumulation of GSK-3β in five human breast cancer cell lines was demonstrated and in 89/128 (70%) human breast carcinomas, whereas no detectable expression of GSK-3β was found in benign breast tissue. Nuclear GSK-3β expression was associated with HER-2 positive tumors (P=0.02) and non-triple negative breast carcinomas (P=0.0001), although nuclear GSK-3β was observed in some samples across all breast cancer subtypes. Aberrant nuclear expression of GSK-3β was found in 11/15 (73%) squamous cell head and neck carcinomas, whereas weak or no detectable expression of GSK-3β was found in benign salivary gland and other benign head and neck tissues. These results support the hypothesis that aberrant nuclear GSK-3β may represent a potential target for the clinical treatment of human breast and squamous cell carcinoma.

Activation of autophagic flux by epigallocatechin gallate mitigates TRAIL-induced tumor cell apoptosis via down-regulation of death receptors

Epigallocatechin gallate (EGCG) is a major polyphenol in green tea. Recent studies have reported that EGCG can inhibit TRAIL-induced apoptosis and activate autophagic flux in cancer cells. However, the mechanism behind these processes is unclear. The present study found that EGCG prevents tumor cell death by antagonizing the TRAIL pathway and activating autophagy flux. Our results indicate that EGCG dose-dependently inhibits TRAIL-induced apoptosis and decreases the binding of death receptor 4 and 5 (DR4 and 5) to TRAIL. In addition, EGCG activates autophagy flux, which is involved in the inhibition of TRAIL cell death. We confirmed that the protective effect of EGCG can be reversed using genetic and pharmacological tools through re-sensitization to TRAIL. The inhibition of autophagy flux affects not only the re-sensitization of tumor cells to TRAIL, but also the restoration of death receptor proteins. This study demonstrates that EGCG inhibits TRAIL-induced apoptosis through the manipulation of autophagic flux and subsequent decrease in number of death receptors. On the basis of these results, we suggest further consideration of the use of autophagy activators such as EGCG in combination anti-tumor therapy with TRAIL.

The destruction complex of beta-catenin in colorectal carcinoma and colonic adenoma

OBJECTIVE

To evaluate the destruction complex of beta-catenin by the expression of the proteins beta-catetenin, adenomatous polyposis coli, GSK3β, axin and ubiquitin in colorectal carcinoma and colonic adenoma.

METHODS

Tissue samples from 64 patients with colorectal carcinoma and 53 patients with colonic adenoma were analyzed. Tissue microarray blocks and slides were prepared and subjected to immunohistochemistry with polyclonal antibodies in carcinoma, adjacent non-neoplastic mucosa, and adenoma tissues. The immunoreactivity was evaluated by the percentage of positive stained cells and by the intensity assessed through of the stained grade of proteins in the cytoplasm and nucleus of cells. In the statistical analysis, the Spearman correlation coefficient, Student's t, χ2, Mann-Whitney, and McNemar tests, and univariate logistic regression analysis were used.

RESULTS

In colorectal carcinoma, the expressions of beta-catenin and adenomatous polyposis coli proteins were significantly higher than in colonic adenomas (p<0.001 and p<0.0001, respectively). The immunoreactivity of GSK3β, axin 1 and ubiquitin proteins was significantly higher (p=0.03, p=0.039 and p=0.03, respectively) in colorectal carcinoma than in the colonic adenoma and adjacent non-neoplastic mucosa. The immunohistochemistry staining of these proteins did not show significant differences with the clinical and pathological characteristics of colorectal cancer and colonic adenoma.

CONCLUSIONS

These results suggest that, in adenomas, the lower expression of the beta-catenin, axin 1 and GSK3β proteins indicated that the destruction complex of beta-catenin was maintained, while in colorectal carcinoma, the increased expression of beta-catenin, GSK3β, axin 1, and ubiquitin proteins indicated that the destruction complex of beta-catenin was disrupted.

OBJETIVO

Avaliar o complexo de destruição da betacatenina no carcinoma colorretal e no adenoma do colo pela expressão das proteínas betacatenina, adenomatous polyposis coli, GSK3β, axina e ubiquitina.

MÉTODOS

Amostras de tecidos de 64 doentes com carcinoma colorretal e de 53 pacientes com adenoma do colo foram analisadas. Blocos de tecidos foram submetidos ao estudo imuno-histoquímico com anticorpos policlonais nos tecidos do carcinoma, mucosa não neoplásica adjacente e adenoma. A imunorreatividade foi avaliada pela porcentagem de positividade de células coradas e pela intensidade do grau de coloração das proteínas no citoplasma e no núcleo das células. Na análise estatística, foram utilizados o coeficiente de correlação de Spearman, os testes t de Student, χ2, Mann-Whitney e de McNemar, e a análise de regressão logística univariada.

RESULTADOS

No carcinoma colorretal, as expressões da betacatenina e da adenomatous polyposis coli foram significativamente maiores do que em adenomas do colo (p<0,001 e p<0,0001, respectivamente). A imunorreatividade das proteínas GSK3β, axina 1 e ubiquitina foi significativamente maior (p=0,03, p=0,039 e p=0,03, respectivamente) no carcinoma colorretal do que no adenoma e na mucosa não neoplásica adjacente. A coloração imuno-histoquímica dessas proteínas não apresentou diferenças significantes em relação às características clinicopatológicas do câncer colorretal e do adenoma.

CONCLUSÕES

Em adenomas, as menores expressões de betacatenina, axina 1 e GSK3β indicaram que o complexo de destruição da betacatenina estava conservado, enquanto que, no carcinoma colorretal, o aumento das expressões da betacatenina, GSK3β, 1 axina, e ubiquitina indicaram que o complexo de destruição de betacatenina estava alterado.

M2-like macrophages induce colon cancer cell invasion via matrix metalloproteinases

The inflammatory milieu plays an important role in colon cancer development and progression. Previously, we have shown that tumor-associated macrophages (TAMs), an important component of the tumor microenvironment, are enriched in tumors compared with normal tissue and confer a poorer prognosis. In the present study, we found that matrix metallopeptidase-9 (MMP-9), which degrades extracellular matrix proteins, was increased in biopsies from colon cancer patients and in mouse xenografts with SW480 cell-derived tumors. SW480 colon cancer cells exposed to M2-like macrophage-conditioned medium (M2-medium) exhibited increased MMP-9 mRNA, protein expression and gelatinase activity. A similar effect was obtained by the addition of tumor necrosis factor-α (TNFα) and leukotriene D₄ (LTD₄ ). MMP-9 expression and activity were reduced by a TNFα blocking antibody adalimumab and a cysteinyl leukotriene receptor 1 (CysLTR1, the receptor for LTD₄ ) antagonist montelukast. M2-medium also induced changes in the epithelial-mesenchymal transition (EMT) markers E-cadherin, β-catenin, vimentin, and snail in SW480 cells. We also found that both M2-medium and TNFα and LTD₄ induced stabilization/nuclear translocation of β-catenin. Furthermore, we also observed an elongated phenotype that may indicate increased invasiveness, as confirmed in a collagen I invasion assay. M2-medium increased the invasive ability, and a similar effect was also obtained by the addition of TNFα and LTD₄ . The specific MMP inhibitor I or adalimumab and montelukast reduced the number of invasive cells. In conclusion, our findings show that M2-medium enriched in TNFα and LTD₄ promote colon cancer cell invasion via MMP-9 expression and activation and the induction of EMT.

Nuclear expression and/or reduced membranous expression of β-catenin correlate with poor prognosis in colorectal carcinoma: A meta-analysis

BACKGROUND

The differential subcellular localizations of β-catenin (including membrane, cytoplasm, and nucleus) play different roles in the progression of colorectal cancer (CRC). However, the correlation between each subcellular localization of β-catenin and the prognosis of CRC patients remains undetermined.

METHODS

Systematic strategies were applied to search for eligible published studies in the PubMed, Embase, and Web of Science databases. The correlation between each subcellular localizations of β-catenin expression and patients' clinicopathological features or prognosis was analyzed.

RESULTS

Finally, this meta-analysis, including 6238 cases from 34 studies, revealed that β-catenin overexpression in the nucleus (HR: 1.50[95% CI: 1.08-2.10]) or reduced expression of β-catenin in the membrane (HR: 1.33[95% CI: 1.15-1.54]) significantly correlated with lower 5-year overall survival (OS). Conversely, overexpression of β-catenin in the cytoplasm (HR: 1.00[95% CI: 0.85-1.18]) did not show significant association with 5-year OS.

CONCLUSION

This study suggested that β-catenin overexpression in the nucleus or reduced expression in the membrane, but not its overexpression in cytoplasm, could serve as a valuable prognostic predictor for CRC. However, additional large and well-designed prospective studies are required to verify our results.

Gene silencing of USP1 by lentivirus effectively inhibits proliferation and invasion of human osteosarcoma cells

Osteosarcoma is the most frequent malignant bone tumor, affecting the extremities of adolescents and young adults. Ubiquitin-specific protease 1 (USP1) plays a critical role in many cellular processes including proteasome degradation, chromatin remodeling and cell cycle regulation. In the present study, we discovered that USP1 was overexpressed in 26 out of 30 osteosarcoma tissues compared to cartilage tumor tissues and normal bone tissues. We then constructed a lentiviral vector mediating RNA interference (RNAi) targeting USP1 and demonstrated that it significantly suppressed the mRNA and protein expression of the USP1 gene in U2OS cells. Knockdown of USP1 inhibited the growth and colony-forming, as well as significantly reduced the invasiveness of U2OS cells. Western blot analysis indicated that suppression of USP1 downregulated the expression of many proteins including SIK2, MMP-2, GSK-3β, Bcl-2, Stat3, cyclin E1, Notch1, Wnt-1 and cyclin A1. Most of these proteins are associated with tumor genesis and development. RNAi of SIK2 significantly decreased SIK2 protein expression and inhibited the ability of forming colonies, as well as induced apoptosis and reduced the invasiveness of U2OS cells. Collectively, our results suggest that silencing USP1 inhibits cell proliferation and invasion in U2OS cells. Therefore, USP1 may provide a novel therapeutic target for the treatment of osteosarcoma.

Niacin alleviates TRAIL-mediated colon cancer cell death via autophagy flux activation

Niacin, also known as vitamin B₃ or nicotinamide is a water-soluble vitamin that is present in black beans and rice among other foods. Niacin is well known as an inhibitor of metastasis in human breast carcinoma cells but the effect of niacin treatment on TRAIL-mediated apoptosis is unknown. Here, we show that niacin plays an important role in the regulation of autophagic flux and protects tumor cells against TRAIL-mediated apoptosis. Our results indicated that niacin activated autophagic flux in human colon cancer cells and the autophagic flux activation protected tumor cells from TRAIL-induced dysfunction of mitochondrial membrane potential and tumor cell death. We also demonstrated that ATG5 siRNA and autophagy inhibitor blocked the niacin-mediated inhibition of TRAIL-induced apoptosis. Taken together, our study is the first report demonstrating that niacin inhibits TRAIL-induced apoptosis through activation of autophagic flux in human colon cancer cells. And our results also suggest that autophagy inhibitors including genetic and pharmacological tools may be a successful therapeutics during anticancer therapy using TRAIL.

GSK-3β-mediated fatty acid synthesis enhances epithelial to mesenchymal transition of TLR4-activated colorectal cancer cells through regulation of TAp63

Glycogen synthase kinase-3β (GSK-3β) in cancer cells is a critical regulatory component of both cellular metabolism and epithelial-mesenchymal transition (EMT) processes via regulation of the β-catenin/E-cadherin and phosphoinositide 3-kinase (PI3K)/AKT signaling pathway. Lipogenesis of cancer cells also plays a critical role in survival and metastasis. We investigated the role of GSK-3β-mediated intracellular fatty acid synthesis to control EMT in TLR4-activated colorectal cancer cells and the underlying regulatory mechanism. Engagement of TLR4 with lipopolysaccharide (LPS) in colon cancer cells promoted the induction of phosphorylated GSK-3β and related lipogenic enzymes as well as the expression of CD74, CD44 and macrophage inhibitory factor (MIF), but decreased expression of transcriptionally active p63 (TAp63). In addition, targeted inhibition of GSK-3β using SB216763 was accompanied by decreased intracellular fatty acid synthesis and blockage of CD74 and CD44 expression, whereas it reversed the level of TAp63. Although TAp63 overexpression had no effect on the expression of CD74 and CD44 in LPS-treated colon cancer cells, GSK-3β-dependent fatty acid synthesis and invasive activity were significantly suppressed. Notably, inhibition of CD44 or CD74 by siRNA not only attenuated de novo lipogenesis and migratory activity but also restored the expression of TAp63 in LPS-activated colon cancer cells. These results suggest that TAp63-mediated GSK-3β activation induced by TLR4 stimulation triggers migration and invasion of colon cancer cells through the regulation of lipid synthesis and GSK-3β-mediated CD74/CD44 expression could be a target to control fatty acid-related EMT process through the modulation of TAp63 expression.

Non-canonical WNT5A signaling up-regulates the expression of the tumor suppressor 15-PGDH and induces differentiation of colon cancer cells

The tumor suppressor 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is the key enzyme in prostaglandin E₂ catabolism and is down-regulated in colorectal cancer (CRC) tissue. Canonical Wnt signaling is frequently elevated in colon cancers and has been shown to down-regulate 15-PGDH expression. Therefore, we have in the current study investigated if the non-canonical ligand WNT5A relates to increased expression of 15-PGDH in colon cancer cells. In the same cohort of patients, we demonstrated a parallel and significant loss of 15-PGDH and WNT5A protein expression in CRC tissues compared with matched normal colon tissues. Furthermore, patients with low 15-PGDH/WNT5A expression in their tumors showed reduced survival compared with patients with high 15-PGDH/WNT5A expression. To investigate if WNT5A signaling directly affects 15-PGDH expression, we performed in vitro analyses of colon cancer cells (HT-29 and Caco-2). Both cell lines, when treated with recombinant WNT5A (rWNT5A) or Foxy-5, a WNT5A-mimicking peptide, responded by increasing their expression of 15-PGDH mRNA and protein. Our investigations showed that rWNT5A and Foxy-5 induced this increased expression of 15-PGDH through reduced β-catenin signaling as well as increased JNK/AP-1 signaling in colon cancer cells. WNT5A signaling also induced increased 15-PGDH expression in a breast cancer cell line both in vitro and in vivo. In agreement, WNT5A signaling also increased the expression of the differentiation markers sucrose-isomaltase and mucin-2 in colon cancer cells. Our results show that WNT5A signaling regulates 15-PGDH expression, thus uncovering a novel mechanism by which WNT5A acts as a tumor suppressor and suggests that increased 15-PGDH expression could be used as an indicator of a positive response to Foxy-5 in patients treated with this WNT5A agonist.

Role of glycogen synthase kinase-3β inhibitor AZD1080 in ovarian cancer

Background

Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase that plays an important role in cancer tumorigenesis and progression. We investigated the role of the GSK-3β inhibitor AZD1080 in ovarian cancer cell lines.

Methods

A2780 and OVCAR3 ovarian cancer cell lines were exposed to AZD1080, after which cell proliferation, cell cycle, invasion, and migration assays were performed. Phalloidin staining was used to observe lamellipodia formation. Reverse transcription polymerase chain reaction and Western blot were used to assess the respective mRNA and protein expression levels of GSK-3β, CDK2, CDK1, cyclin D1, matrix metalloproteinase-9 (MMP9), and Bcl-xL.

Results

AZD1080 exposure suppressed ovarian cancer cell proliferation, invasion, migration, and lamellipodia formation, and induced G₁ arrest, which was concentration dependent. AZD1080 also significantly downregulated GSK-3β, CDK2, CDK1, cyclin D1, MMP9, and Bcl-xL expression at both mRNA and protein levels.

Conclusion

Taken together, our results demonstrate that the GSK-3β inhibitor AZD1080 suppresses ovarian cancer development and therefore may indicate a new direction for ovarian cancer treatment.

Effects of the GSK-3β inhibitor (2Z,3E)-6-bromoindirubin-3'-oxime upon ovarian cancer cells

Ovarian cancer (OC) is a deadly disease, and despite improvements in treatment, overall 5-year survival is low. Glycogen synthase kinase (GSK)-3β is a multifunctional serine/threonine kinase. We wished to ascertain if the GSK-3β inhibitor (2Z,3E)-6-bromoindirubin-3'-oxime, known as "BIO," can suppress OC development. The OC cell lines A2780 and OVCAR3 were exposed to BIO. At different time points, cell proliferation, apoptosis, cell cycle, and cell invasion/cell migration assays were carried out. Phalloidin staining was undertaken to observe lamellipodia formation. Real-time reverse transcription-polymerase chain reaction and western blotting were used to assess expression of messenger RNA (mRNA) and protein of GSK-3β, cyclin D1, matrix metalloproteinase (MMP)-9, and p21. BIO suppressed the proliferation, invasion, and migration of OC cells; reduced lamellipodia formation; and induced G1 arrest of the cell cycle. BIO exposure led to a significant downregulation of mRNA and protein expression of cyclin D1 and MMP9 in comparison with untreated control cells. In contrast, BIO exposure upregulated mRNA and protein expression of p21 in comparison with untreated control cells. Besides, GSK-3β small interfering RNA (siRNA) transfection in ovarian cancer cells also downregulated GSK-3β, cyclin D1, and MMP9 protein expression while upregulated p21 expression. These data suggest that BIO, as an inhibitor of GSK-3β, can suppress OC development. Therefore, BIO could be a candidate drug for the treatment of OC.

Glycogen synthase kinase-3: a potential preventive target for prostate cancer management

OBJECTIVES

Prostate cancers are the frequently diagnosed cancers in men, and patients with metastatic disease only have 28% chance for 5-year survival. Patients with low-risk tumors are subjected to active surveillance, whereas high-risk cases are actively treated. Unfortunately, there is no cure for patients with late-stage disease. Glycogen synthase kinase-3 (GSK-3, α and β) is a protein serine/threonine kinase and has diverse cellular functions and numerous substrates. We sought to summarize all the studies done with GSK-3 in prostate cancers and to provide a prospective direction for future work.

METHODS AND MATERIALS

A comprehensive search of the literature on the electronic databases PubMed was conducted for the subject terms of GSK-3 and prostate cancer. Gene mutation and expression information was extracted from Oncomine and COSMIC databases. Case reports were not included.

RESULTS

Accumulating evidence indicates that GSK-3α is mainly expressed in low-risk prostate cancers and is related to hormone-dependent androgen receptor (AR)-mediated gene expression, whereas GSK-3β is mainly expressed in high-risk prostate cancers and is related to hormone-independent AR-mediated gene expression. GSK-3 has been demonstrated as a positive regulator in AR transactivation and prostate cancer growth independent of the Wnt/β-catenin pathway. Different types of GSK-3inhibitors including lithium show promising results in suppressing tumor growth in different animal models of prostate cancer. Importantly, clinical use of lithium is associated with reduced cancer incidence in psychiatric patients.

CONCLUSIONS

Taken together, GSK-3 inhibition might be implicated in prostate cancer management as a preventive treatment.

Role of MCP-1 in alcohol-induced aggressiveness of colorectal cancer cells

Epidemiological studies demonstrate that alcohol consumption is associated with an increased risk of colorectal cancer (CRC). In addition to promoting carcinogenesis, alcohol may also accelerate the progression of existing CRC. We hypothesized that alcohol may enhance the aggressiveness of CRC. In this study, we investigated the effect of alcohol on the migration/invasion and metastasis of CRC. Alcohol increased the migration/invasion of colorectal cancer cells (DLD1, HCT116, HT29, and SW480) in a concentration-dependent manner. Among these colon cancer cell lines, HCT116 cells were most responsive while HT29 cells were the least responsive to ethanol-stimulated cell migration/invasion. These in vitro results were supported by animal studies which demonstrated that ethanol enhanced the metastasis of colorectal cancer cells to the liver and lung. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that plays an important role in regulating tumor microenvironment and metastasis. Alcohol increased the expression of MCP-1 and its receptor CCR2 at both protein and mRNA levels. The pattern of alcohol-induced alterations in MCP-1 expression was consistent with its effect on migration/invasion; HCT116 cells displayed the highest up-regulation of MCP-1/CCR2 in response to alcohol exposure. An antagonist of CCR2 blocked alcohol-stimulated migration. Alcohol caused an initial cytosolic accumulation of β-catenin and its subsequent nuclear translocation by inhibiting GSK3β activity. Alcohol stimulated the activity of MCP-1 gene promoter in a β-catenin-dependent manner. Furthermore, knock-down of MCP-1/CCR2 or β-catenin was sufficient to inhibit alcohol-induced cell migration/invasion. Together, these results suggested that alcohol may promote the metastasis of CRC through modulating GSK3β/β-catenin/MCP-1 pathway.

Loss of vinculin and membrane-bound β-catenin promotes metastasis and predicts poor prognosis in colorectal cancer

BACKGROUND

Loss of cell-cell adhesion is important for the development of cancer invasion and metastasis. Vinculin, a key adhesion-related protein, can affect metastasis and prognosis in several tumours. Here, we determined the biological roles of vinculin in the metastasis of colorectal cancer (CRC) and evaluated its clinical significance as a potential disease biomarker.

METHODS

The expression level of vinculin in CRC cell lines and tissues was measured using Real-Time PCR and western blotting. Moreover, vinculin function was analysed using Transwell assays and in vivo metastasis assays in gain- and loss-of-function experiments. Furthermore, the impact of vinculin together with membrane-bound β-catenin on the prognosis of 228 CRC patients was investigated by immunohistochemistry. Additionally, the expression of epithelial-mesenchymal transition (EMT) indicators was verified by immunohistochemistry in CRC tissues obtained from these patients.

RESULT

Vinculin expression was found to be significantly downregulated in highly metastatic CRC cell lines and metastatic tissues. Both in vitro and in vivo experiments showed that vinculin suppressed invasion, migration and metastasis in CRC cells and that this suppression could be attenuated by silencing β-catenin. Moreover, the expression of vinculin and membrane-bound β-catenin were positively correlated in CRC tissues, and lack of vinculin expression emerged as an independent prognostic factor in patients with CRC. Finally, the loss of vinculin and membrane-bound β-catenin was associated with node metastasis, organ metastasis and expression of EMT indicators.

CONCLUSION

Our results suggest that vinculin may play specific roles in the EMT and metastasis of CRC and that loss of vinculin could be used as a prognostic factor for CRC.

6-Bromoindirubin-3'oxime (BIO) decreases proliferation and migration of canine melanoma cell lines

Despite recent therapeutic advances, malignant melanoma is an aggressive tumor in dogs and is associated with a poor outcome. Novel, targeted agents are necessary to improve survival. In this study, 6-bromoindirubin-3'-oxime (BIO), a serine/threonine kinase inhibitor with reported specificity for glycogen synthase kinase-3 beta (GSK-3β) inhibition, was evaluated in vitro in three canine melanoma cell lines (CML-10C2, UCDK9M2, and UCDK9M3) for β-catenin-mediated transcriptional activity, Axin2 gene and protein expression levels, cell proliferation, chemotoxicity, migration and invasion assays. BIO treatment of canine malignant melanoma cell lines at 5 µM for 72 h enhanced β-catenin-mediated transcriptional activity, suggesting GSK-3β inhibition, and reduced cell proliferation and migration. There were no significant effects on invasion, chemotoxicity, or apoptosis. The results suggest that serine/threonine kinases may be viable therapeutic targets for the treatment of canine malignant melanoma.

GSK-3β-regulated N-acetyltransferase 10 is involved in colorectal cancer invasion

PURPOSE

NAT10 (N-acetyltransferase 10) is a nucleolar protein, but may show subcellular redistribution in colorectal carcinoma. In this study, we evaluated membranous staining of NAT10 in colorectal carcinoma and its clinical implications, and explored the mechanism of regulation of NAT10 redistribution.

EXPERIMENTAL DESIGN

The expression and subcellular redistribution of NAT10, β-catenin, E-cadherin, and GSK-3β were evaluated by immunohistochemistry in 222 cases of colorectal carcinoma. Regulation of NAT10 and its influence on cell motility were analyzed with inhibitors of GSK-3β, transfection of wild-type or kinase-inactivated GSK-3β, or expression of various domains of NAT10, and evaluated with immunofluorescence, Western blotting, and Transwell assays.

RESULTS

NAT10 localized mainly in the nucleoli of normal tissues, and was redistributed to the membrane in cancer cells, particularly at the invasive "leading edge" of the tumor. This correlated well with nuclear accumulation of β-catenin (P<0.001; χ2=68.213). In addition, NAT10 membrane staining reflected the depth of invasion and tendency to metastasize (all P values<0.001), and was associated with a poorer prognosis (P=0.023; χ2=5.161). Evaluation of the mechanism involved demonstrated that subcellular redistribution of NAT10 may result from its increased stability and nuclear export, which is brought about by inhibition of GSK-3β. Moreover, redistribution of NAT10 induces alteration of cytoskeletal dynamics and increases cancer cell motility.

CONCLUSION

The subcellular redistribution of NAT10 can be induced by decreases in GSK-3β activity. This redistribution increases cancer cell motility, and is, thus, correlated with invasive potential and poorer clinical outcome. This finding suggests that NAT10 may be a useful prognostic marker and potential therapeutic target in colorectal carcinoma.

Regulation of TRAIL receptor expression by β-catenin in colorectal tumours

Tumour-necrosis-factor-related apoptosis-inducing ligand (TRAIL) is being investigated as a targeted cancer therapeutic and the expression of its pro-apoptotic receptors, DR4 and DR5, increases during colorectal carcinogenesis. This study investigated the role of β-catenin in the regulation of these receptors. In human colorectal adenoma and carcinoma cell lines, downregulation of β-catenin resulted in lower total DR4 and DR5 protein levels. Similarly, cell membrane expression of DR4 and DR5 was reduced after downregulation of β-catenin in colon carcinoma cells, whereas induction of β-catenin in HeLa cells led to increased cell membrane expression of DR4 and DR5. Downregulation of β-catenin decreased the recombinant human TRAIL sensitivity of human colon carcinoma cells. Activation of the transcription factor T-cell factor-4 (TCF-4) is an important function of β-catenin. Dominant-negative TCF-4 overexpression, however, did not significantly affect TRAIL receptor expression or recombinant human TRAIL sensitivity. Human colorectal adenomas (N = 158) with aberrant (cytoplasmic and nuclear) β-catenin expression had a higher percentage of immunohistochemical DR4 and DR5 staining per tumour (mean: 73 and 88%, respectively) than those with membranous β-catenin staining only (mean: 50 and 70%, respectively, P < 0.01 for both). Furthermore, aberrant β-catenin staining co-localized with DR4 and DR5 expression in 92% of adenomas. In 53 human colorectal carcinomas, aberrant β-catenin expression was present in most cases and DR4/5 expression was largely homogenous. Similarly, in adenomas from APC(min) mice, cytoplasmic β-catenin staining co-localized with staining for the murine TRAIL death receptor. In conclusion, the gradual increase in TRAIL receptor expression during colorectal carcinogenesis is at least partially mediated through increased β-catenin expression, independently of TCF-4-signalling.

The inflammatory mediator leukotriene D₄ induces subcellular β-catenin translocation and migration of colon cancer cells

The abnormal activation of the Wnt/β-catenin pathway frequently occurs in colorectal cancer. The nuclear translocation of β-catenin activates the transcription of target genes that promote cell proliferation, survival, and invasion. The pro-inflammatory mediator leukotriene D4 (LTD4) exerts its effects through the CysLT1 receptor. We previously reported an upregulation of CysLT1R in patients with colon cancer, suggesting the importance of leukotrienes in colon cancer. The aim of this study was to investigate the impact of LTD4 on Wnt/β-catenin signaling and its effects on proliferation and migration of colon cancer cells. LTD4 stimulation led to an increase in β-catenin expression, β-catenin nuclear translocation and the subsequent transcription of MYC and CCND1. Furthermore, LTD4 significantly reduced the expression of E-cadherin and β-catenin at the plasma membrane and increased the migration and proliferation of HCT116 colon cancer cells. The effects of LTD4 can be blocked by the inhibition of CysLT1R. Furthermore, LTD4 induced the inhibition of glycogen synthase kinase 3 (GSK)-3β activity, indicating a crosstalk between the G-protein-coupled receptor CysLT1 and the Wnt/β-catenin pathway. In conclusion, LTD4, which can be secreted from macrophages and leukocytes in the tumor microenvironment, induces β-catenin translocation and the activation of β-catenin target genes, resulting in the increased proliferation and migration of colon cancer cells.

SIRT1 Expression Is Associated with Good Prognosis in Colorectal Cancer

Background

Silent mating type information regulation 2 homolog 1 (SIRT1), an NAD+-dependent deacetylase, might act as a tumor promoter by inhibiting p53, but may also as a tumor suppressor by inhibiting several oncogenes such as β-catenin and survivin. Deleted in breast cancer 1 (DBC1) is known as a negative regulator of SIRT1.

Methods

Immunohistochemical expressions of SIRT1, DBC1, β-catenin, surviving, and p53 were evaluated using 2 mm tumor cores from 349 colorectal cancer patients for tissue microarray.

Results

Overexpression of SIRT1, DBC1, survivin, and p53 was seen in 235 (67%), 183 (52%), 193 (55%), and 190 (54%) patients, respectively. Altered expression of β-catenin was identified in 246 (70%) patients. On univariate analysis, overexpression of SIRT1 (p=0.029) and altered expression of β-catenin (p=0.008) were significantly associated with longer overall survival. Expression of SIRT1 was significantly related to DBC1 (p=0.001), β-catenin (p=0.001), and survivin (p=0.002), but not with p53. On multivariate analysis, age, tumor stage, differentiation, and expression of SIRT1 were independent prognostic factors significantly associated with overall survival.

Conclusions

SIRT1 overexpression is a good prognostic factor for colorectal cancer, and SIRT1 may interact with β-catenin and survivin rather than p53.

Interleukin-9 (IL-9) and NPM-ALK each generate mast cell hyperplasia as single 'hit' and cooperate in producing a mastocytosis-like disease in mice

Mast cell neoplasms are characterized by abnormal growth and focal accumulation of mast cells (MC) in one or more organs. Although several cytokines, including stem cell factor (SCF) and interleukin-9 (IL-9) have been implicated in growth of normal MC, little is known about pro-oncogenic molecules and conditions triggering differentiation and growth of MC far enough to lead to the histopathological picture of overt mastocytosis. The anaplastic lymphoma kinase (ALK) has recently been implicated in growth of neoplastic cells in malignant lymphomas. Here, we describe that transplantation of NPM-ALK-transplanted mouse bone marrow progenitors into lethally irradiated IL-9 transgenic mice not only results in lymphoma-formation, but also in the development of a neoplastic disease exhibiting histopathological features of systemic mastocytosis, including multifocal dense MC-infiltrates, occasionally with devastating growth in visceral organs. Transplantation of NPM-ALK-transduced progenitors into normal mice or maintenance of IL-9-transgenic mice without NPM-ALK each resulted in MC hyperplasia, but not in mastocytosis. Neoplastic MC in mice not only displayed IL-9, but also the IL-9 receptor, and the same was found to hold true for human neoplastic MC. Together, our data show that neoplastic MC express IL-9 receptors, that IL-9 and NPM-ALK upregulate MC-production in vivo, and that both'hits' act in concert to induce a mastocytosis-like disease in mice. These data may have pathogenetic and clinical implications and fit well with the observation that neoplastic MC in advanced SM strongly express NPM and multiple "lymphoid" antigens including CD25 and CD30.