The expression and significance of Gal-3 and MUC1 in colorectal cancer and colon cancer

Galectins in epithelial-mesenchymal transition: roles and mechanisms contributing to tissue repair, fibrosis and cancer metastasis

Galectins are soluble glycan-binding proteins that interact with a wide range of glycoproteins and glycolipids and modulate a broad spectrum of physiological and pathological processes. The expression and subcellular localization of different galectins vary among tissues and cell types and change during processes of tissue repair, fibrosis and cancer where epithelial cells loss differentiation while acquiring migratory mesenchymal phenotypes. The epithelial-mesenchymal transition (EMT) that occurs in the context of these processes can include modifications of glycosylation patterns of glycolipids and glycoproteins affecting their interactions with galectins. Moreover, overexpression of certain galectins has been involved in the development and different outcomes of EMT. This review focuses on the roles and mechanisms of Galectin-1 (Gal-1), Gal-3, Gal-4, Gal-7 and Gal-8, which have been involved in physiologic and pathogenic EMT contexts.

MUC1 promotes lymph node metastasis in esophageal squamous cell carcinoma by downregulating DNAJB6 expression

BACKGROUND

Aberrant expression of MUC1 correlates with the progression of esophageal squamous cell carcinoma (ESCC), this study aimed to explore the effect of targeting MUC1 by Go-203 on malignant behavior of ESCC and the underlying mechanism.

METHODS AND RESULTS

IHC was used to examine the expression of MUC1 and DNAJB6 in ESCC samples. qRT-PCR and western blotting were used to examine the expression of MUC1 and DNAJB6 in ESCC cell lines. CCK8, wound healing, and transwell assays were used to determine the effect of regulating MUC1/DNAJB6 on the proliferation, migration, and invasion of ESCC cells. The effect of overexpressing/targeting MUC1 on the activation of the AKT/HSF-1 pathway was determined by western blotting. A negative correlation was confirmed between the expression of DNAJB6 and MUC1 in ESCC tissue samples by IHC, and high expression of MUC1 and low expression of DNAJB6 correlated with lymph node metastasis in ESCC patients. Overexpressing MUC1 downregulated the expression of DNAJB6, promoted ESCC proliferation, invasion, migration and activated the AKT pathway, while targeting MUC1 suppressed proliferation, invasion, migration, and the AKT pathway and up-regulated DNAJB6 expression in vitro. Moreover, MUC1 increased the phosphorylation of HSF-1 via the AKT pathway, and inhibiting AKT-HSF-1 increased the expression of DNAJB6 in vitro.

CONCLUSIONS

This study indicated that MUC1 could promote tumorigenesis and metastasis in ESCC by downregulating DNAJB6 expression through AKT-HSF-1 pathway.

The Mucin Family of Proteins: Candidates as Potential Biomarkers for Colon Cancer

Mucins (MUC1-MUC24) are a family of glycoproteins involved in cell signaling and barrier protection. They have been implicated in the progression of numerous malignancies including gastric, pancreatic, ovarian, breast, and lung cancer. Mucins have also been extensively studied with respect to colorectal cancer. They have been found to have diverse expression profiles amongst the normal colon, benign hyperplastic polyps, pre-malignant polyps, and colon cancers. Those expressed in the normal colon include MUC2, MUC3, MUC4, MUC11, MUC12, MUC13, MUC15 (at low levels), and MUC21. Whereas MUC5, MUC6, MUC16, and MUC20 are absent from the normal colon and are expressed in colorectal cancers. MUC1, MUC2, MUC4, MUC5AC, and MUC6 are currently the most widely covered in the literature regarding their role in the progression from normal colonic tissue to cancer.

MCP mediated active targeting calcium phosphate hybrid nanoparticles for the treatment of orthotopic drug-resistant colon cancer

BACKGROUND

Colon cancer is a most common malignant cancer in digestive system, and it is prone to develop resistance to the commonly used chemotherapy drugs, leading to local recurrence and metastasis. Paris saponin VII (PSVII) could not only inhibit the proliferation of colon cancer cells but also effectively induce apoptosis of drug-resistant colon cancer cells and reduce the metastasis of drug-resistant colon cancer cells as well. However, PSVII was insoluble in water and fat. It displayed no selective distribution in body and could cause severe hemolysis. Herein, colon cancer targeting calcium phosphate nanoparticles were developed to carry PSVII to treat drug-resistant colon cancer.

RESULTS

PSVII carboxymethyl-β-cyclodextrin inclusion compound was successfully encapsulated in colon cancer targeting calcium phosphate nanoparticles (PSVII@MCP-CaP) by using modified citrus pectin as stabilizer agent and colon cancer cell targeting moiety. PSVII@MCP-CaP significantly reduced the hemolysis of PSVII. Moreover, by specific accumulating in orthotopic drug-resistant colon cancer tissue, PSVII@MCP-CaP markedly inhibited the growth of orthotopic drug-resistant colon cancer in nude mice. PSVII@MCP-CaP promoted the apoptosis of drug-resistant colon cancer cells through mitochondria-mediated apoptosis pathway. Moreover, PSVII@MCP-CaP significantly inhibited the invasion and migration of drug-resistant colon cancer cells by increasing E-cadherin protein expression and reducing N-cadherin and MMP-9 protein expression.

CONCLUSION

PSVII@MCP-CaP has great potential in the treatment of drug-resistant colon cancer. This study also explores a new method to prepare active targeting calcium phosphate nanoparticles loaded with a fat and water insoluble compound in water.

Beyond Colonoscopy: Exploring New Cell Surface Biomarkers for Detection of Early, Heterogenous Colorectal Lesions

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths among both men and women in the United States. Early detection and surgical removal of high-risk lesions in the colon can prevent disease from developing and spreading. Despite implementation of programs aimed at early detection, screening colonoscopies fail to detect a fraction of potentially aggressive colorectal lesions because of their location or nonobvious morphology. Optical colonoscopies, while highly effective, rely on direct visualization to detect changes on the surface mucosa that are consistent with dysplasia. Recent advances in endoscopy techniques and molecular imaging permit microscale visualization of the colonic mucosa. These technologies can be combined with various molecular probes that recognize and target heterogenous lesion surfaces to achieve early, real-time, and potentially non-invasive, detection of pre-cancerous lesions. The primary goal of this review is to contextualize existing and emergent CRC surface biomarkers and assess each’s potential as a candidate marker for early marker-based detection of CRC lesions. CRC markers that we include were stratified by the level of support gleaned from peer-reviewed publications, abstracts, and databases of both CRC and other cancers. The selected biomarkers, accessible on the cell surface and preferably on the luminal surface of the colon tissue, are organized into three categories: (1) established biomarkers (those with considerable data and high confidence), (2) emerging biomarkers (those with increasing research interest but with less supporting data), and (3) novel candidates (those with very recent data, and/or supportive evidence from other tissue systems). We also present an overview of recent advances in imaging techniques useful for visual detection of surface biomarkers, and discuss the ease with which these methods can be combined with microscopic visualization.

Mucin-1 expression and localization in epithelial cells shows characteristic and distinct patterns in inflammatory bowel diseases and colorectal cancer

Alterations in colonic mucus secretion are linked to the induction and maintenance of inflammation during inflammatory bowel disease (IBD) and its progression to colorectal cancer (CRC). MUC1, a multifunctional glycoprotein, is the best studied cell surface mucin in mouse models of IBD and CRC. However, little information on MUC1 expression and localization in different types of pathologic human colon mucosa is available. In this work, expression and subcellular localization of MUC1 in different types of diseased human colon mucosa from a cohort of Tunisian patients is analyzed and correlated with the type of disorder. Colon tissue samples were obtained from 39 cases of CRC and 18 cases of IBD. 13 cases of normal adjacent colon mucosa tissues served as controls. Biopsies were subjected to immunohistochemical analysis of MUC1 expression. Signals were quantified densitometrically and characterized with regard to tissue and intracellular distribution. Results were then correlated with the different types of colon disorder. Immunohistochemical investigation of MUC1 in a cohort of inflammatory bowel diseases and colorectal cancer showed a significant divergence in the expression of MUC1 in terms intensity (18.96% ± 0.55 vs 27.26% ± 1.24 respectively; P=0.005) and localization between the two types of lesions (30.76% vs 70.96% respectively; P=0.0199). Our findings show divergent characteristic patterns for MUC1 expression and localization in different types of pathologic alterations of the colon mucosa. These results are of potential diagnostic and predictive clinical value.

MiR-206 inhibits proliferation, migration, and invasion of gastric cancer cells by targeting the MUC1 gene

Background

MicroRNAs (miRNAs) can regulate the post-transcriptional level of gene expression. It has been documented that downregulation of miR-206 is significant in human gastric cancer (GC), whereas its role in GC cell biological behaviors, including proliferation, migration, and invasion, has not been thoroughly investigated. MiR-206 levels have a negative association with lymph node metastasis and tumor invasion, and patients with higher miR-206 expression have better prognoses. Functional studies demonstrated that miR-206 overexpression significantly suppresses GC cell proliferation, migration, and invasion, and induces apoptosis in vitro.

Materials and methods

MiR-206 and MUC1 were determined by RNA extraction, quantitative real-time polymerase chain reaction, and luciferase reporter gene assays. The viability of GC cells was tested using the Cell Counting Kit 8 assay. Transwell invasion and migration assays detected GC cancer cell proliferation, invasion, and migration. Flow cytometry was applied to analyze apoptotic cells. FACS analysis was applied to detect the mitochondrial membrane potential of cells. Western blotting assay determined protein levels.

Results

The luciferase reporter gene assay demonstrated that miR-206 might directly bind to the 3'UTR of the MUC1 gene and suppress MUC1 expression. Furthermore, MUCI expression was upregulated and inversely associated with miR-206 levels in GC tissues. More importantly, the miR-206-mediated suppression of proliferation, migration, and invasion, and the induction of apoptosis, were abrogated by MUC1 overexpression.

Conclusion

Our data demonstrated that miR-206 may exert antitumor activities through inhibiting the expression of MUC1, which may serve as an effective and potential target for GC treatment.

MUC1 expression in colorectal carcinoma: Clinicopathological correlation and prognostic significance

INTRODUCTION

MUC1 overexpression has been linked to cancer development and has been associated with a higher stage at diagnosis and presence of lymph node or distant metastases. However, its prognostic significance is still unclear. We aimed to evaluate the relationship between MUC1 expression and prognosis of colorectal carcinoma.

MATERIALS AND METHODS

Immunohistochemical expression of MUC1 in 96 colorectal carcinomas with analysis of potential prognostic influence.

RESULTS

55.2% of patients were women and the mean age was 65.9 years. Tumors were more frequently located in rectum or sigmoid colon (60.4% and 21.9%). Most tumors were T3 (60.3%). 36.9% of patients showed lymph node metastases and 30.2% showed distant metastasis at the time of diagnosis. MUC1 was intensely positive in 46% and negative in 37.9% of tumors. Overall, 61% of patients recurred and 40.4% died during follow-up. 58.5% of tumors of surviving patients were intensely positive for MUC1 and 29.5% were negative, as compared with 28.5% (intense positivity) and 51.4% (negativity) in the group of patients who died (p=0.022). 65% of tumors of patients without recurrences showed intense positivity for MUC1 and 23% of them were negative as compared with 33.9% (intense positivity) and 47% (negativity) in the group of patients who recurred (p=0.019).

CONCLUSIONS

Loss of MUC1 expression was more frequent in cases with disease recurrence or death, as compared with patients with stable disease, in whom intense positivity was more frequently seen. These findings disagree with the majority of previous studies, indicating the need for further investigation.

Differential expression of mucin 1 and mucin 2 in colorectal cancer

AIM

To determine tissue expression (mRNA, protein) of two types of mucins [mucin 1 (MUC1) and mucin 2 (MUC2)] in patients with colorectal cancer (CRC).

METHODS

Expression of membrane-bound mucin (MUC1) and secretory mucin (MUC2) in CRC (mRNA, protein) were analyzed in tissue material including fragments of tumors obtained from CRC patients (n = 34), and fragments of normal colorectal tissue from the same patients (control). The analysis was conducted using real-time quantitative polymerase chain reaction (RT-qPCR) (transcripts), immunohistochemistry (IHC) (apomucins), and the modern approach for morphometric analysis of IHC reaction (HSV filter software). Results on tissue expression of both mucins (mRNA, protein) were compared to histological alterations in colorectal cancer samples and correlated with selected clinical data in the patients. The statistical analysis was conducted using Statistica PL v. 12.0 software.

RESULTS

Significantly higher expression of the MUC1 mRNA in the CRC, compared with the control and the borderline correlation of mRNA expression with MUC1 protein levels in colorectal samples was observed. The expression of apomucins concerned cell membranes (MUC1) and cytoplasm (MUC2) and occurred both in control tissues and in most cancerous samples. There were no significant relationships between MUC1 (mRNA, protein) and the clinicopathological data of patients. MUC2 protein expression was significantly lower as compared to the control, while MUC2 mRNA expression was comparable in both groups. The MUC1/MUC2 ratio was significantly higher in CRC tissues than in the control. The higher expression of MUC2 was a feature of mucinous CRC subtypes, and characterized higher histological stage of tumors. Negative correlations have been obtained between MUC2 and the Ki-67 antigen, as well as between MUC2 and p53 protein expressions in CRC.

CONCLUSION

A combination of tissue overexpression of MUC1, reduced MUC2 expression, and high ratio of MUC1/MUC2 is a factor of poor prognosis in CRC patients. MUC2 tissue expression allows to differentiate mucinous and nonmucinous CRC subtypes.