Expression of mucin 1 (MUC1) in esophageal squamous-cell carcinoma: its relationship with prognosis

Analysis of Molecular Genetic Variants of Lgals4 in Esophageal Cancer: A Preliminary Report

Esophageal cancer is the eighth most common cancer worldwide and fourth most common in developing countries. Altered glycosylation pattern of cell membrane molecules along with inflammation is a characteristic attribute of oncogenesis. Galectin-4, a tandem repeat galectin, has shown effect on cancer progression/metastasis in digestive system cancers. This role of galectin-4 can be attributed to variations in LGALS4, gene encoding galectin-4. The present case-control study was designed to analyze four intronic SNPs in LGALS4 with susceptibility toward esophageal cancer.Esophageal cancer cases and age- and gender-matched apparently healthy individuals were recruited for the present study. Genotyping of rs8113319, rs4802886, rs4802887, and rs12610990 was carried out using Sanger sequencing and PCR-RFLP. MedCalc software, SNPStats and SHEsis online platform were used for statistical analysis.Genotypic analyses revealed an overall increased heterozygosity of rs12610990, rs4802886, and rs4802887, and AA genotype of rs8113319 in the study participants. Haplotypic analyses also revealed a predominance of AAAT haplotype in the cases. Moreover, combined presence of wild alleles of rs4802886 and rs4802887 could influence protection toward disease, and combined presence of wild alleles of rs12610990 and rs8113319 could influence disease susceptibility. Furthermore, a strong linkage disequilibrium was also observed between the SNPs. Further studies are underway to validate galectin-4 and its genetic variants as blood-based biomarkers in early disease diagnosis, improving treatment outcome.

Inhibition of MUC1-C entering nuclear suppresses MYC expression and attenuates malignant growth in esophageal squamous cell carcinoma

Background

The mucin 1 (MUC1) heterodimeric protein (N-terminal subunit and C-terminal subunit) is aberrantly overexpressed in esophageal squamous cell carcinoma (ESCC) and has been linked to poor outcomes in this disease. The detailed mechanism(s), however, remains unclear. In this article, we investigate the effects of the MUC1 C-terminal transmembrane subunit (MUC1-C) through the inhibitor GO-201, which inhibits MUC1-C targeting to nuclear.

Patients and methods

The expression of MUC1-C and MYC in the ESCC samples and cell lines was detected by immunohistochemistry, immunofluorescence and western blotting. MYC mRNA level was determined by using quantitative real-time polymerase chain reaction. In addition, Cell Counting Kit-8, clonogenic assay, transwell assay and tumor xenograft in nude mice assay were utilized to determine the role of MUC1-C in proliferation, invasion and migration of ESCC cells.

Results

The level of MUC1-C in nuclear and MYC in whole cells in the ESCC tissue is significantly higher than that in the noncancerous tissue. Treatment of MUC1-C-overexpressing ESCC cells with GO-201 was associated with downregulation of MYC expression and induction of apoptosis. Besides, in vitro and in vivo assays have both shown that inhibiting MUC1-C targeting to the nucleus by the GO-201 significantly decreased the abilities of proliferation, invasion and migration in ESCC cells.

Conclusion

Our findings suggest that MUC1-C targeting to the nucleus plays an important role in suppressing the malignant growth of ESCC and indicate that MUC1-C is a potential target for the treatment of ESCC.

Clinical effect of MUC1 and its relevance to BRAF V600E mutation in papillary thyroid carcinoma: a case-control study

AIM

To investigate the clinical effects of MUC1 on papillary thyroid cancer (PTC) and explore the relationship between MUC1 expression and BRAF mutation.

METHODS

The data of 69 patients subjected to fine-needle aspiration biopsy in our hospital and 486 patient data downloaded from The Cancer Genome Atlas (TCGA) database were used. Univariate and multivariate analyses were performed.

RESULTS

The results on the 486 patients recorded in the TCGA indicated that high MUC1 expression was independently related to BRAF mutation, lymph node metastasis (LNM), and unifocal type. In the 69 fine-needle aspiration biopsy patients with PTC, high MUC1 expression was significantly related to LNM and extrathyroid extension (ETE). The result of Pearson's correlation coefficient showed that BRAF mutation and MUC1 expression were moderately correlated. Moreover, in the subgroup with low MUC1 expression, the patients with BRAF mutation had higher ETE frequency and LNM than those without BRAF mutation. In the subgroup with BRAF mutation, patients with high MUC1 expression exhibited higher ETE frequency than those with low MUC1 expression, and high MUC1 expression occurred in older patients. In the subgroup with BRAF wild-type mutation, patients with high MUC1 expression had a higher incidence of ETE and LNM than those with low expression.

CONCLUSION

We demonstrated that the MUC1 is an important oncogene in PTC and may have great significance on therapeutic cancer vaccine development.

Upregulation of mucin glycoprotein MUC1 in the progression to esophageal adenocarcinoma and therapeutic potential with a targeted photoactive antibody-drug conjugate

BACKGROUND

Mucin glycoprotein 1 (MUC1) is a glycosylated transmembrane protein on epithelial cells. We investigate MUC1 as a therapeutic target in Barrett's epithelium (BE) and esophageal adenocarcinoma (EA) and provide proof of concept for a light based therapy targeting MUC1.

RESULTS

MUC1 was present in 21% and 30% of significantly enriched pathways comparing BE and EA to squamous epithelium respectively. MUC1 gene expression was x2.3 and x2.2 higher in BE (p=<0.001) and EA (p=0.03). MUC1 immunohistochemical expression increased during progression to EA and followed tumor invasion. HuHMFG1 based photosensitive antibody drug conjugates (ADC) showed cell internalization, MUC1 selective and light-dependent cytotoxicity (p=0.0006) and superior toxicity over photosensitizer alone (p=0.0022).

METHODS

Gene set enrichment analysis (GSEA) evaluated pathways during BE and EA development and quantified MUC1 gene expression. Immunohistochemistry and flow cytometry evaluated the anti-MUC1 antibody HuHMFG1 in esophageal cells of varying pathological grade. Confocal microscopy examined HuHMFG1 internalization and HuHMFG1 ADCs were created to deliver a MUC1 targeted phototoxic payload.

CONCLUSIONS

MUC1 is a promising target in EA. Molecular and light based targeting of MUC1 with a photosensitive ADC is effective in vitro and after development may enable treatment of locoregional tumors endoscopically.

TG4010: a vaccine with a therapeutic role in cancer

One of the strategies to enhance immune response against tumors has been the use of vaccines against tumor-associated antigens (TAAs). MUC1 is a TAA that is overexpressed in many malignancies being linked to worse prognosis. Moreover, tumor MUC1 is hypoglycosylated revealing new epitopes that are antigenic and potential T-cell targets. TG4010 is a recombinant viral vaccine targeting MUC1, also encoding for IL-2. TG4010 has been tested in Phase I-II trials demonstrating a consistent safety profile with mild local reactions as main side effect. These studies have confirmed immune responses to the vaccine product. Clinical efficacy has been observed mainly in patients with non-small-cell lung cancer in combination with chemotherapy. Peripheral activated NK cells are currently being validated as biomarkers of response.

Identification of Potential Drug Targets in Cancer Signaling Pathways using Stochastic Logical Models

The investigation of vulnerable components in a signaling pathway can contribute to development of drug therapy addressing aberrations in that pathway. Here, an original signaling pathway is derived from the published literature on breast cancer models. New stochastic logical models are then developed to analyze the vulnerability of the components in multiple signalling sub-pathways involved in this signaling cascade. The computational results are consistent with the experimental results, where the selected proteins were silenced using specific siRNAs and the viability of the cells were analyzed 72 hours after silencing. The genes elF4E and NFkB are found to have nearly no effect on the relative cell viability and the genes JAK2, Stat3, S6K, JUN, FOS, Myc, and Mcl1 are effective candidates to influence the relative cell growth. The vulnerabilities of some targets such as Myc and S6K are found to vary significantly depending on the weights of the sub-pathways; this will be indicative of the chosen target to require customization for therapy. When these targets are utilized, the response of breast cancers from different patients will be highly variable because of the known heterogeneities in signaling pathways among the patients. The targets whose vulnerabilities are invariably high might be more universally acceptable targets.

CCL21-CCR7 promotes the lymph node metastasis of esophageal squamous cell carcinoma by up-regulating MUC1

Background

CCR7 and MUC1 are correlated with lymph node metastasis in ESCC, but the role of MUC1 in the CCR7-induced lymphatic metastasis and the underlying molecular mechanism is still unclear.

Methods

The expression of CCR7 and MUC1 was detected in the ESCC samples by IHC, and the clinical significance of CCR7 and MUC1 in ESCC was analyzed. The expression of CCR7 and MUC1 in ESCC cell lines was detected by qRT-PCR and western blot. The effect of CCL21 on the migration and invasion of ESCC cells was determined by transwell assay. The activity of MUC1 promoter was determined by luciferase reporter assay. The activation of Erk, Akt and Sp1 was detected by western blot and the binding of Sp1 to the MUC1 promoter was determined by ChIP.

Results

The co-expression of CCR7 and MUC1 was detected in 153 ESCC samples by IHC, and both were correlated with lymph node metastasis, regional lymphatic recurrence and poor prognosis. Correspondingly, increasing levels of MUC1 mRNA and protein were detected in the ESCC cell lines KYSE410 and Eca9706 after treatment with CCL21 in a time- and dose-dependent manner. Furthermore, silencing MUC1 could remarkably suppress the invasion and migration of ESCC cells induced by CCL21. Moreover, heterologous CCR7 promoted the invasion and migration of KYSE150 and up-regulated MUC1 expression. Increasing levels of activated ERK1/2 and Akt were detected in KYSE410 after treating the cells with CCL21, and inhibiting the activation of ERK1/2 but not Akt caused the increased transcription of MUC1. Finally, the phosphorylation of Sp1 induced by ERK1/2 and subsequent increases in the binding of Sp1 to the muc1 promoter at −99/−90 were confirmed to cause the up-regulation of MUC1 induced by CCL21-CCR7.

Conclusions

Our findings suggested that MUC1 plays an important role in CCL21-CCR7-induced lymphatic metastasis and may serve as a therapeutic target in ESCC.

Identification of New Candidate Genes and Chemicals Related to Esophageal Cancer Using a Hybrid Interaction Network of Chemicals and Proteins

Cancer is a serious disease responsible for many deaths every year in both developed and developing countries. One reason is that the mechanisms underlying most types of cancer are still mysterious, creating a great block for the design of effective treatments. In this study, we attempted to clarify the mechanism underlying esophageal cancer by searching for novel genes and chemicals. To this end, we constructed a hybrid network containing both proteins and chemicals, and generalized an existing computational method previously used to identify disease genes to identify new candidate genes and chemicals simultaneously. Based on jackknife test, our generalized method outperforms or at least performs at the same level as those obtained by a widely used method - the Random Walk with Restart (RWR). The analysis results of the final obtained genes and chemicals demonstrated that they highly shared gene ontology (GO) terms and KEGG pathways with direct and indirect associations with esophageal cancer. In addition, we also discussed the likelihood of selected candidate genes and chemicals being novel genes and chemicals related to esophageal cancer.

Mechanisms of antitumor and immune-enhancing activities of MUC1/sec, a secreted form of mucin-1

Mucin 1 (MUC1) is a polymorphic type 1 transmembrane protein found on the apical surface of normal cells lining the lumen of ducts and glands. Mucins are thought to provide mucosal protection from environmental exposures and carcinogens. An altered form of the MUC1 glycoprotein, which is hypoglycosylated, is expressed in several types of human cancers. In our laboratory, we have found that transfection of a murine mammary tumor cell line with a human secreted isoform of MUC1 rendered these DA-3 cells (DA-3/sec) incapable of growing in intact BALB/c mice. In contrast, implantation of DA-3 cells transfected with the human transmembrane isoform of MUC1 (DA-3/TM), resulted in tumor formation and ultimately death of the animals, similar to the DA-3 parental line. Importantly, inoculation of the DA-3/sec cells in immunodeficient nude mice resulted in tumor formation, indicating that the MUC1/sec molecule's antitumor activity is immunologically controlled. In this review, we summarize the studies we have performed to elucidate possible mechanisms for the immune-mediated antitumor effect of MUC1/sec and/or a unique peptide present in this mucin. Understanding these mechanisms may provide new immunotherapeutic approaches that could be used to target different types of cancer.

Combination of MUC1 and MUC4 expression predicts clinical outcome in patients with oral squamous cell carcinoma

BACKGROUND

Both MUC1 and MUC4 are high molecular weight glycoproteins and are independent indicators of worse prognosis in many human epithelial cancers including oral squamous cell carcinoma (OSCC). However, there has been no investigation of the clinical importance of the co-expression of MUC1 and MUC4 in OSCC. The aim of this study was to evaluate the co-expression profile of MUC1/MUC4 and analyze the prognostic significance in OSCC.

METHODS

We examined the expression profile of MUC1 and MUC4 in OSCC tissues from 206 patients using immunohistochemistry. The co-expression profile of MUC1/MUC4 and its prognostic significance in OSCC was statistically analyzed.

RESULTS

MUC1 and MUC4 overexpression were strongly correlated with each other (p < 0.0001) and a combination of both MUC1 and MUC4 expression was a powerful indicator for tumor aggressiveness such as tumor size (p = 0.014), lymph node metastasis (0.0001), tumor stage (p = 0.006), diffuse invasion (p = 0.028), and vascular invasion (p = 0.014). The MUC1/MUC4 double-positive patients showed the poorest overall and disease-free survival. Multivariate analysis revealed that MUC1/MUC4 double-positivity was the strong independent prognostic factor for overall and disease-free survival (p = 0.007 and (p = 0.0019), in addition to regional recurrence (p = 0.0025).

CONCLUSIONS

Taken together, these observations indicate that the use of a combination of MUC1/MUC4 can predict outcomes for patients with OSCC. This combination is also a useful marker for predicting regional recurrence. MUC1 and MUC4 may be attractive targets for the selection of treatment methods in OSCC.

The effect of MUC1 rs4072037 functional polymorphism on cancer susceptibility: evidence from published studies

Genome-wide association studies have identified a susceptibility variation MUC1 rs4072037 for gastric cancer in Chinese population. Subsequent case-control studies have reported this association in other populations. However, the results remain controversial and ambiguous. The aim of this study is to provide a precise quantification for the association between MUC1 rs4072037 variation and the risk of cancer. We performed pooled analysis of 10 case-control designed studies including 4,220 cases and 6,384 controls. Odds ratios (OR) and 95% confidence interval (95%CI) were calculated to assess strength of association in overall studies and in subgroup analysis stratified by ethnicity and cancer types. All statistical analyses were performed by Manager 5.0 and Stata 12.0 software. Overall, the MUC1 rs4072037 polymorphism was associated with risk of cancer in all genetic models (G vs A: OR = 0.71, 95%CI: 0.63-0.80, p<0.01; GA vs AA: OR = 0.61, 95%CI:0.55-0.67, p<0.01; GG vs AA: OR = 0.58, 95%CI: 0.47-0.71, p<0.01; AG+AA vs GG: OR = 0.60, 95%CI: 0.55-0.60, p<0.01; GG vs AG+AA: OR = 0.70, 95%CI: 0.58-0.85, p<0.01). Further, subgroup analysis based on ethnicity suggested MUC1 rs4072037 polymorphism had a subtly reduced cancer risk among Asian population, and stratified analysis by cancer types showed significantly decreased risk of gastric cancer in all genetic models. In conclusion, MUC1 rs4072037 polymorphism may be used as potential biomarker for cancer susceptibility particularly for gastric cancer and for Asian population.

Superparamagnetic iron oxide-C595: Potential MR imaging contrast agents for ovarian cancer detection

Superparamagnetic iron oxide nanoparticles (SPIONs), have played an important role in the promotion of image contrast in magnetic resonance imaging modality. The objective of present study is describing SPIONs conjugated with C595 monoclonal antibody (mAb) against MUC1-expressing ovarian cancer (OVCAR3) cell. Magnetic resonance imaging parameters of the prepared nanoconjugate was investigated in vitro: characterization, cell toxicity, flow cytometry, Prussian blue staining, and cellular uptake as well as biodistribution and magnetic resonance signal intensities under in vivo conditions were also investigated. Magnetic resonance imaging and biodistribution results showed good tumor accumulation and detection, no cytotoxicity, and potential selective as anti-ovarian cancer. In conclusion, based on the findings SPIONs-C595 nanosized-probe is potentially, a selective ovarian molecular imaging tool. Further subsequent in vivo studies and clinical trials are warranted.

Host response in tumor diagnosis and prognosis: importance of immunologists and pathologists alliance

Pathologists and immunologists have collaborated over many years in their efforts to understand and properly diagnose cancer. The ability of pathologists to correctly diagnose this disease was facilitated by the development of immunohistology that utilized specificity of antibodies to distinguish between normal cells and cancer cells. Further boost was provided through the advent of monoclonal antibodies. The two disciplines are now together on the brink of a paradigm shift resulting from a better understanding of the importance for cancer diagnosis and prognosis to consider not only the characteristics of the cancer cells, but also the cancer microenvironment reflecting the host response to the disease. This new immunology and pathology alliance named "Immunoscore" will advance research in both disciplines as well as benefit patients.

Clear cell variant of squamous cell carcinoma originating in the esophagus: report of a case with immunohistochemical and oncogenetic analyses

The cutaneous clear cell squamous cell carcinoma (SCC) is a rare tumor thought to be associated with hair follicle or skin appendage differentiation. We report herein a rare variant case of a clear cell SCC originating in the esophagus. A 70-year-old Japanese man was found to have a tumor in the esophagus. The excised neoplasm showed dominance of clear cell over conventional SCC components; the two components in an apparent continuum. The clear cells, regular in size with a moderate nuclear/cytoplasmic ratio and relatively hyperchromatic and centrally located nuclei, were compactly arranged in sheets. Glycogen deposition was apparent on PAS staining with or without diastase digestion and under the electron microscope. The clear cell SCC components were positive for cytokeratin (CK)7, CK8, CK18 and CK19, but were negative for CK5/6 or CK14. Reciprocal staining patterns of CKs were apparent in conventional SCC components. The present case and cutaneous clear cell SCC counterparts share some histopathologic characteristics whereas CKs expression differs between the two. Overexpression of p53 protein, without evidence of any mutation, and reduced p16(INK4a) were noted in both clear cell and conventional SCC components. No mutations of Kras, BRAF or β-catenin genes were found in both tumor components.

Mucins in human neoplasms: clinical pathology, gene expression and diagnostic application

Mucins are high molecular weight glycoproteins that play important roles in carcinogenesis and tumor invasion. Our immunohistochemical studies demonstrated that MUC1 or MUC4 expression is related to the aggressive behavior and poor outcome of human neoplasms. MUC2 is expressed in indolent pancreatobiliary neoplasms, but these tumors sometimes show invasive growth with MUC1 expression in invasive areas. MUC5AC shows de novo high expression in many types of precancerous lesions of pancreatobiliary cancers and is an effective marker for early detection of the neoplasms. The combination of MUC1, MUC2, MUC4 and MUC5AC expression may be useful for early detection and evaluation of the potential for malignancy of pancreatobiliary neoplasms. Regarding the mechanism of mucin expression, we have recently reported that expression of the mucin genes is regulated epigenetically in cancer cell lines, using quantitative MassARRAY analysis, methylation-specific polymerase chain reaction analysis and chromatin immunoprecipitation analysis, with confirmation by the treatment with 5-aza-2'-deoxycytidine and trichostatin A. We have also developed a monoclonal antibody against the MUC1 cytoplasmic tail domain, which has many biological roles. Based on all of the above findings, we suggest that translational research into mucin gene expression mechanisms, including epigenetics, may provide new tools for early and accurate detection of human neoplasms.

Aberrant overexpression of membrane-associated mucin contributes to tumor progression in adult T-cell leukemia/lymphoma cells

Aberrant overexpression of membrane-associated mucin (MUC1) is implicated in the pathogenesis of cancer, particularly of adenocarcinomas. Adult T-cell leukemia/lymphoma (ATL), an aggressive neoplasm etiologically associated with human T-lymphotropic virus type-1 (HTLV-1), exhibits invasive tropism into various organs, resulting in disease progression and resistance to treatment. In the present study, we showed that MUC1 is overexpressed exclusively in cells of ATL among hematological malignancies. Furthermore, increased expression of MUC1 correlated with a poor prognosis, suggesting MUC1 to be a prognostic marker in ATL. Various functional analyses with knockdown experiments using a specific siRNA for MUC1 revealed that MUC1 is involved in cell growth, cell aggregation, and resistance to apoptosis. Although it has been shown that the anti-adhesive properties of MUC1 facilitate migration and metastasis of tumor cells, our findings indicated that MUC1 contributes to cell-cell adhesion. Mucins thus seem to play a role in the pathogenesis and/or progression of ATL.

MUC4: a novel prognostic factor of oral squamous cell carcinoma

MUC4 mucin is now known to be expressed in various normal and cancer tissues. We have previously reported that MUC4 expression is a novel prognostic factor in several malignant tumors; however, it has not been investigated in oral squamous cell carcinoma (OSCC). The aim of our study is to evaluate the prognostic significance of MUC4 expression in OSCC. We examined the expression profile of MUC4 in OSCC tissues from 150 patients using immunohistochemistry. Its prognostic significance in OSCC was statistically analyzed. MUC4 was expressed in 61 of the 150 patients with OSCC. MUC4 expression was significantly correlated with higher T classification (p = 0.0004), positive nodal metastasis (p = 0.049), advanced tumor stage (p = 0.002), diffuse invasion of cancer cells (p = 0.004) and patient's death (p = 0.004) in OSCC. Multivariate analysis showed that MUC4 expression (p = 0.011), tumor location (p = 0.032) and diffuse invasion (p = 0.009) were statistically significant risk factors. Backward stepwise multivariate analysis demonstrated MUC4 expression (p = 0.0015) and diffuse invasion (p = 0.018) to be statistically significant independent risk factors of poor survival in OSCC. The disease-free and overall survival of patients with MUC4 expression was significantly worse than those without MUC4 expression (p < 0.0001 and p = 0.0001). In addition, the MUC4 expression was a significant risk factor for local recurrence and subsequent nodal metastasis in OSCC (p = 0.017 and p = 0.0001). We first report MUC4 overexpression is an independent factor for poor prognosis of patients with OSCC; therefore, patients with OSCC showing positive MUC4 expression should be followed up carefully.

MUC1 induces metastasis in esophageal squamous cell carcinoma by upregulating matrix metalloproteinase 13

Esophagus squamous cell carcinoma (ESCC) is one of the most deadly malignances because of its high frequency of metastasis. Given the associations of MUC1 with ESCC and tumor metastasis, we explored a potential role of MUC1 in ESCC metastasis. Among 40 ESCC and 20 paired normal tissue specimens examined, we found a significant increase of MUC1 expression in ESCC and more importantly, that expression of MUC1 and MMP13 are strongly correlated in patients who had lymph node metastasis. Studies with cell models indicated that overexpression of MUC1 upregulates the expression of MMP13, leading to increased cell migration. In support of a mode of transcriptional regulation, promoter analysis revealed that MUC1 stimulates MMP13 expression through the Runx-2-binding site. The link of MUC1 to cell motility was further confirmed by the finding that depletion of MUC1 resulted in reduced expression of MMP13 and cell migration, invasion and adhesion. Moreover, the loss of cell metastatic potential was rescued by overexpression of MMP13 completely. Collectively, our findings indicate that MUC1 contributes to ESCC metastasis by stimulating MMP13 expression, suggesting MUC1 as a novel diagnostic biomarker and therapeutic target in ESCC.

Epigenetic regulation of mucin genes in human cancers

Mucins are high molecular weight glycoproteins that play important roles in diagnostic and prognostic prediction and in carcinogenesis and tumor invasion. Regulation of expression of mucin genes has been studied extensively, and signaling pathways, transcriptional regulators, and epigenetic modification in promoter regions have been described. Detection of the epigenetic status of cancer-related mucin genes is important for early diagnosis of cancer and for monitoring of tumor behavior and response to targeted therapy. Effects of micro-RNAs on mucin gene expression have also started to emerge. In this review, we discuss the current views on epigenetic mechanisms of regulation of mucin genes (MUC1, MUC2, MUC3A, MUC4, MUC5AC, MUC5B, MUC6, MUC16, and MUC17) and the possible clinical applications of this epigenetic information.

Muc-1 expression may help characterize thyroid nodules but does not predict patients' outcome

Our purpose was to evaluate MUC1 clinical utility in the diagnosis and prognosis of thyroid cancer patients. We studied the protein expression of MUC1 in 289 thyroid carcinomas and 121 noncancerous thyroid nodules. There were 41 follicular carcinomas (FC) and 248 papillary thyroid carcinomas (PTC) including 149 classic (CPTC), 20 tall cell (TCPTC) and 79 follicular variants (FVPTC). In addition, we used a quantitative real-time PCR (q-PCR) method to measure MUC1 mRNA expression levels in 108 carcinomas, 23 hyperplasias, and 19 FA. According to their serum Tg levels and other evidences of recurrence/metastasis, the patients were classified as free-of-disease (185 cases) or bad outcome (56 cases, 10 deaths). MUC1 protein was identified in 80.2% PTC; 48.8% FC; 68.3% FVPTC; 70% TCPTC; 21.8% FA; 30% hyperplasias and 6% normal thyroid tissues. MUC1 distinguished benign from malignant thyroid tissues (sensitivity = 89%; specificity = 53%). MUC1 also differentiated FC from FA (p = 0.0083). q-PCR mRNA expression of MUC1 also distinguished malignant from benign nodules (Mann-Whitney test, p < 0.0001). However, neither IHC nor mRNA MUC1 expression was associated with any clinical or pathological feature of aggressiveness or outcome. We suggest that MUC1 expression may help differentiate follicular patterned thyroid lesions.

The membrane-bound mucins: From cell signalling to transcriptional regulation and expression in epithelial cancers

The membrane-bound mucins belong to an ever-increasing family of O-glycoproteins. Based on their structure and localization at the cell surface they are thought to play important biological roles in cell-cell and cell-matrix interactions, in cell signalling and in modulating biological properties of cancer cells. Among them, MUC1 and MUC4 mucins are best characterized. Their altered expression in cancer (overexpression in the respiratory, gastro-intestinal, urogenital and hepato-biliary tracts) indicates an important role for these membrane-bound mucins in tumour progression, metastasis, cancer cell resistance to chemotherapeutics drugs and as specific markers of epithelial cancer cells. Some mechanisms responsible for MUC1 and MUC4 role in tumour cell properties have been deciphered recently. However, much remains to be done in order to understand the molecular mechanisms and signalling pathways that control the expression of membrane-bound mucins during the different steps of tumour progression toward adenocarcinoma and evaluate their potential as prognostic/diagnostic markers and as therapeutic tools. In this review we focus on the molecular mechanisms and signalling pathways known to control the expression of membrane-bound mucins in cancer. We will discuss the mechanisms of regulation at the promoter level (including genetic and epigenetic modifications) that may be responsible for the mucin altered pattern of expression in epithelial cancers.

Targeted endoscopic imaging

Endoscopy has undergone explosive technological growth in recent years, and with the emergence of targeted imaging, its truly transformative power and impact on medicine lies just over the horizon. Today, our ability to see inside the digestive tract with medical endoscopy is headed toward exciting crossroads. The existing paradigm of making diagnostic decisions based on observing structural changes and identifying anatomic landmarks may soon be replaced by visualizing functional properties and imaging molecular expression. In this novel approach, the presence of intracellular and cell surface targets unique to disease are identified and used to predict the likelihood of mucosal transformation and response to therapy. This strategy could result in the development of new methods for early cancer detection, personalized therapy, and chemoprevention. This targeted approach will require further development of molecular probes and endoscopic instruments, and will need support from the US Food and Drug Administration for streamlined regulatory oversight. Overall, this molecular imaging modality promises to significantly broaden the capabilities of the gastroenterologist by providing a new approach to visualize the mucosa of the digestive tract in a manner that has never been seen before.

Precursor lesions of pancreatic cancer

This review article describes morphological aspects, gene abnormalities, and mucin expression profiles in precursor lesions such as pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and mucinous cystic neoplasm (MCN) of the pancreas, as well as their relation to pancreatic ductal adenocarcinoma (PDAC). The gene abnormalities in precursors of PDAC are summarized as follows: (1) KRAS mutation and p16/CDKN2A inactivation are early events whose frequencies increase with the dysplasia grade in both PanIN and IPMN; (2) TP53 mutation and SMAD4/DPC4 inactivation are late events observed in PanIN3 or carcinomatous change of IPMN in both PanIN and IPMN, although the frequency of the TP53 mutation is lower in IPMN than in PDAC; and (3) also in MCN, KRAS mutation is an early event whose frequency increases with the dysplasia grade, whereas TP53 mutation and SMAD4/DPC4 inactivation are evident only in the carcinoma. The mucin expression profiles in precursors of PDAC are summarized as follows: (1) MUC1 expression increases with the PanIN grade, and is high in PDAC; (2) the expression pattern of MUC2 differs markedly between the major subtypes of IPMN with different malignancy potentials (i.e., IPMN-intestinal type with MUC2+ expression and IPMN-gastric type with MUC2- expression); (3) MUC2 is not expressed in any grade of PanINs, which is useful for differentiating PanIN from intestinal-type IPMN; (4) de novo expression of MUC4, which appears to increase with the dysplasia grade; and (5) high de novo expression of MUC5AC in all grades of PanINs, all types of IPMN, MCN, and PDAC.

Expression profiles of MUC1, MUC2, and MUC4 mucins in human neoplasms and their relationship with biological behavior

Mucins are high molecular weight glycoproteins that play important roles in carcinogenesis or tumor invasion. To clarify the relationship of the expression patterns of mucins in human neoplasms with their biological behavior, we examined the expression profiles of MUC1, MUC2, and MUC4 mucins in various human neoplasms using immunohistochemistry and in situ hybridization, and compared them with clinicopathologic factors including outcome of the patients. MUC1 or MUC4 expression is related with the aggressive behavior of human neoplasms and a poor outcome of the patients. In contrast, MUC2 expression tends to be related with the indolent behavior of human neoplasms and a favorable outcome of the patients, although indolent pancreatobiliary neoplasms sometimes show invasive growth with MUC1 expression in the invasive areas. The expression of MUC2 mucin in indolent pancreatobiliary neoplasms coincided with expression of MUC2 mRNA. Our recent studies to clarify the MUC2 gene regulation mechanism disclosed that DNA methylation and histone modification in the 5' flanking region of the MUC2 promoter may play an important role. Further studies of the epigenetics also in MUC1 and MUC4 gene expression may be needed to understand the relationship between the expression of mucins in human neoplasms with their biological behavior.

Mucin expression profile in pancreatic cancer and the precursor lesions

In this review article, we demonstrate the mucin expression profile in normal tissue, invasive ductal carcinoma (IDC), two subtypes of intraductal papillary-mucinous neoplasm (IPMN dark cell type and IPMN clear cell type), pancreatic intraepithelial neoplasia (PanIN), and mucinous cystic neoplasm (MCN) of the pancreas. In MUC1, there are various glycoforms, such as poorly glycosylated MUC1, sialylated MUC1, and fully glycosylated MUC1. IDCs showed high expression of all the glycoforms of MUC1. IPMNs dark cell type showed no expression or low expression of all the glycoforms of MUC1. IPMNs clear cell type showed low expression of poorly glycosylated MUC1, but expression of sialylated MUC1 and fully glycosylated MUC1. Expression of MUC2 was negative in IDCs, high in IPMNs dark cell type and low in IPMNs clear cell type. MUC5AC was highly expressed in IDCs, IPMNs dark cell type, and IPMNs clear cell type. MUC6 expression was higher in IPMNs clear cell type than in IDCs and IPMNs dark cell type. Our recent study demonstrated that high expression of MUC4 in IDCs is correlated with a poor outcome for patients. In PanINs, expression of both MUC5AC and MUC6 are an early event, whereas up-regulation of MUC1 is a late event. MCNs do not look as if they will show a specific mucin expression profile according to the literature review.

Expression of MUC1 in primary and metastatic human epithelial ovarian cancer and its therapeutic significance

BACKGROUND

MUC1 is associated with cellular transformation and tumorigenicity and is considered as an important tumor-associated antigen (TAA) for cancer therapy. The objective of this study was to evaluate the patterns of MUC1 expression in primary tumors and metastatic lesions in the advanced stages of epithelial ovarian cancers (EOCs) and correlate the expression with clinicopathological features.

METHODS

The expression of MUC1 was examined on frozen tissue sections from primary EOC (n=42), the matched metastatic lesions (n=30) and paraffin-embedded tissue sections from primary EOC (n=60), normal ovarian tissues (n=20) using immunohistochemistry (IHC) by monoclonal antibody (MAb) C595.

RESULTS

The expression of MUC1 was found in 92% (39/42) of EOC and 90% (27/30) of the matched metastatic lesions in frozen tissue sections respectively while the expression of MUC1 was found in 95% (57/60) of EOC and 5% (1/20) of normal ovarian tissues in paraffin-embedded sections respectively. Most of the tumors showed moderate to strong intensity staining while normal ovarian tissues only showed weak intensity staining. The overexpression of MUC1 was significantly associated with various progression parameters such as tumor stage, grade, residual disease status and presence of ascites (P<0.05).

CONCLUSIONS

MUC1 is overexpressed in above 90% of late stage of EOC and of metastatic lesions but not in normal ovarian tissues, and the high expression of MUC1 is correlated with EOC progression. MUC1 antigen may be a useful therapeutic target to prevent the development of incurable, recurrent metastatic EOC.

MUC1, MUC2, MUC4, MUC5AC and MUC6 expression in the progression of prostate cancer

Molecular changes are vital for the development of prognostic markers and therapeutic modalities of prostate cancer (CaP). There is growing interest in mucins as treatment targets in human malignancies, including CaP. The role of their expression in the progression of CaP is however unclear. We examined the expressions MUC1, MUC2, MUC4, MUC5AC and MUC6 in CaP tissues using tissue microarrays (TMAs) to look for tumor-associated antigens (TAAs) for targeted therapy. In this study, 120 paraffin-embedded specimens were selected from patients who underwent radical retro-pubic prostatectomy (RRP) or trans-urethral-resection of the prostate (TURP) for primary, untreated CaP and 10 matched lymph node metastases. A series of MUC monoclonal antibodies (mAbs) was used on TMAs by standard immunohistochemistry. Our results indicate that the over-expression of MUC1 was detected in 58% of primary CaP tissues and 90% of lymph node metastases but not in normal prostate or benign tissues, while the expression of MUC2, MUC4, MUC5AC and MUC6 was found to be negative in both normal and cancer tissues. Of the MUC1 positive tumors 86% were Gleason grade 7 or higher. Over-expression of MUC1 was found in late stage CaP while MUC2, 4, 5AC and 6 were negative in CaP. MUC1 is a TAA that is highly related to tumor progression in CaP patients. This antigen is ideal for targeted therapy to control micrometastases and hormone refractory disease but additional studies are necessary to assess its usefulness in patient biopsies and CaP bone metastases before clinical trial.

Assessment of KL-6 as a tumor marker in patients with hepatocellular carcinoma

AIM: To investigate the clinical significance of KL-6 as a tumor marker of HCC in two different ethnic groups with chronic liver disease consecutively encountered at outpatient clinics.

METHODS: Serum KL-6 was measured by the sandwich enzyme immunoassay method using the KL-6 antibody (Ab) as both the capture and tracer Ab according to the manufacturer’s instructions (Eisai, Tokyo, Japan). Assessment of alpha fetoprotein (AFP) and protein induced vitamin K deficiency or absence (PIVKA-II) was performed in both groups using commercially available kits.

RESULTS: A significantly higher mean serum KL-6 (556±467 U/L) was found in HCC in comparison with non-HCC groups either with (391±176 U/L; P<0.001) or without (361±161 U/L; P<0.001) liver cirrhosis (LC). Serum KL-6 level did not correlate with either AFP or PIVKA-II serU/Levels. Using receiver operating curve analysis for KL-6 as a predictor for HCC showed that the area under the curve was 0.574 (95%CI = 0.50-0.64) and the KL-6 level that gave the best sensitivity (61%) was found to be 334 U/L but according to the manufacturer’s instructions; a cut-off point of 500 U/L was used that showed the highest specificity (80%) in comparison with AFP and PIVKA-II (78% vs 72% respectively). Combining the values of the three markers improved specificity of AFP for HCC diagnosis from 78% for AFP alone; 93% for AFP plus PIVKA-II to 99% for both plus KL-6 value (P<0.001). Mean serum alkaline phosphatase level was significantly higher in KL-6 positive (564±475) in comparison with KL-6 negative (505±469) HCC patients (P = 0.021), but such a difference was not found among non-HCC corresponding groups.

CONCLUSION: KL-6 is suggested as a tumor for HCC. Its positivity may reflect HCC-associated cholestasis and/or local tumor invasion.

MUC4 expression is a novel prognostic factor in patients with invasive ductal carcinoma of the pancreas

BACKGROUND

Many patients with invasive ductal carcinoma of the pancreas (IDC) have a poor outcome. MUC4 expression has been implicated as a marker for diagnosis and progression of IDC, but there are no studies of the relation between MUC4 expression and patient prognosis in IDC.

AIMS

To investigate the prognostic significance of MUC4 expression in IDC.

METHODS

The expression profiles of MUC4, ErbB2, p27, and MUC1 were investigated in IDC tissues from 135 patients by means of immunohistochemistry.

RESULTS

MUC4 was expressed in 43 of the 135 patients with IDC (31.9%). The survival of 21 patients with high MUC4 expression (>20% of neoplastic cells stained) was significantly worse than that of the 114 patients with low MUC4 expression (<20% of neoplastic cells stained) (p = 0.0043). Univariate analysis showed that high MUC4 expression (p = 0.0061), large primary tumour status (>T2) (p = 0.0436), distant metastasis (p = 0.0383), lymphatic invasion (p = 0.0243), and surgical margins (p = 0.0333) were significant risk factors affecting the outcome of patients with IDC. Backward stepwise multivariate analysis showed that MUC4 expression (p = 0.0121), lymph node metastasis (p = 0.0245), and lymphatic invasion (p = 0.0239) were significant independent risk factors. ErbB2, p27, and MUC1 were not independent risk factors.

CONCLUSIONS

This study shows that MUC4 expression in IDC is a new independent factor for poor prognosis and predicts the outcome of patients with IDC.

MUC4 and ErbB2 expression in squamous cell carcinoma of the upper aerodigestive tract: correlation with clinical outcomes

OBJECTIVES/HYPOTHESIS

Expression of the membrane mucin MUC4 has been associated with a variety of malignancies, including squamous cell carcinoma of the upper aerodigestive tract. MUC4 modulates cell signaling pathways as an intramembrane ligand of ErbB2. The hypotheses of the study were that MUC4 expression would correlate with ErbB2 expression and that MUC4 expression would correlate with clinical outcomes in squamous cell carcinoma of the upper aerodigestive tract.

STUDY DESIGN

Retrospective chart review was combined with immunohistochemical analysis of paraffin-embedded tumor specimens from patients treated with initial definitive surgical resection at an academic tertiary care medical center.

METHODS

MUC4 and ErbB2 receptor expression was localized by immunohistochemical studies using archival formalin-fixed and paraffin-embedded tissue. A limited number of fresh-frozen tissues were further analyzed by Western blot. Clinical outcomes and histopathological parameters were determined by retrospective chart review and correlated with immunohistochemical findings.

RESULTS

One hundred fifty-four patients were analyzed with a median follow-up of 12 months among 54 patients who died and 49 months among 100 surviving patients. Membrane expression of MUC4 and ErbB2 was seen in 12% and 13% of tumors, respectively. MUC4 expression was not correlated with pathological grade. A significant correlation was found between MUC4 expression and ErbB2 expression. Multivariate survival analyses revealed that patients whose tumors exhibited MUC4 membrane expression had statistically significant improvement in survival and longer time to recurrence compared with patients whose tumors did not express MUC4 as defined by immunohistochemical staining patterns. No correlations between ErbB2 expression and survival or recurrence were observed.

CONCLUSION

Patients with tumors that retain MUC4 expression exhibit improved survival and decreased recurrence in squamous cell carcinoma of the upper aerodigestive tract. Correlations between MUC4 expression patterns and ErbB2 expression are also observed, suggesting that MUC4-ErbB2 mediated cell signaling pathways may provide insights into this clinical result.

A monoclonal antibody to a carbohydrate epitope expressed on glycolipid and on alpha3beta1 integrin on human esophageal carcinoma

A mouse monoclonal antibody (MAb-9) produced by immunization with a human esophageal carcinoma cell line, TE-2 (derived from undifferentiated squamous cell carcinoma) reacted specifically with about 30% of esophageal carcinoma cell lines and tissue sections from clinical samples. MAb-9 showed minimal reactivity with normal esophageal tissue. (125)I, fluorescent or gold particle labeled MAb-9 bound to TE-2 cell surfaces. (125)I-radiolabeled MAb-9 was used to detect reactive material from cell extracts in Western blot. Treatment of TE-2 membrane proteins with neuraminidase, N-glycanase or O-glycanase reduced antigen detection. Treatment of cells with periodic acid destroyed antibody binding in ELISA. Lipid extracts from cell membranes, containing glycolipids, also reacted with MAb-9. MAb-9 was used to purify target antigen from detergent solubilized membrane proteins and the prominent bands from subsequent gel electrophoresis were trypsin digested and analyzed by mass spectrometry. Peptides from alpha(3) and beta(1) integrin chains were identified. These data indicate that alpha3beta1integrin is prominently expressed on certain esophageal carcinomas and that a specific carbohydrate unit is selectively displayed on the alpha(3) integrin subunit as well as on glycolipid on the cell surface. The alpha3beta1 integrin expressed on A-431 carcinoma cells does not display this carbohydrate epitope and is not detected by MAb-9. Thus, expression of the carbohydrate epitope is the basis for the tumor selective reaction of MAb-9 with a subset of esophageal carcinomas.

Transcriptional regulation of human mucin MUC4 by bile acids in oesophageal cancer cells is promoter-dependent and involves activation of the phosphatidylinositol 3-kinase signalling pathway

Abnormal gastro-oesophageal reflux and bile acids have been linked to the presence of Barrett's oesophageal premalignant lesion associated with an increase in mucin-producing goblet cells and MUC4 mucin gene overexpression. However, the molecular mechanisms underlying the regulation of MUC4 by bile acids are unknown. Since total bile is a complex mixture, we undertook to identify which bile acids are responsible for MUC4 up-regulation by using a wide panel of bile acids and their conjugates. MUC4 apomucin expression was studied by immunohistochemistry both in patient biopsies and OE33 oesophageal cancer cell line. MUC4 mRNA levels and promoter regulation were studied by reverse transcriptase-PCR and transient transfection assays respectively. We show that among the bile acids tested, taurocholic, taurodeoxycholic, taurochenodeoxycholic and glycocholic acids and sodium glycocholate are strong activators of MUC4 expression and that this regulation occurs at the transcriptional level. By using specific pharmacological inhibitors of mitogen-activated protein kinase, phosphatidylinositol 3-kinase, protein kinase A and protein kinase C, we demonstrate that bile acid-mediated up-regulation of MUC4 is promoter-specific and mainly involves activation of phosphatidylinositol 3-kinase. This new mechanism of regulation of MUC4 mucin gene points out an important role for bile acids as key molecules in targeting MUC4 overexpression in early stages of oesophageal carcinogenesis.

Expression of MUC1 (EMA) and E-cadherin in renal cell carcinoma: a systematic immunohistochemical analysis of 188 cases

MUC1 (epithelial membrane antigen) is a membrane-associated mucin known to interfere with both cell-cell and cell-matrix adhesions. Overexpression has been associated with poor prognosis in a variety of cancers. We investigated the expression of MUC1 (using two different antibodies, MA695 and E29) and E-cadherin in renal cell carcinomas (137 conventional, 23 chromophobe, 20 papillary, and eight unclassified tumors) with respect to diagnostic and prognostic significance using a tissue microarray technique. Immunoreactivity was correlated with histological subtype, pT-stage, and grade using the chi2 test or the Fisher's exact test, respectively. Impact on disease-free survival was analyzed using the Kaplan-Meier method and the log-rank test. Immunoreactivity of more than 10% of cancer cells with MA695, E 29, and E-cadherin antibodies was found in 112/133 (84%), 86/133 (65%), and 7/131 (5%) conventional, 20/22 (91%), 19/22 (86%), and 21/22 (95%) chromophobe, 13/20 (65%), 8/20 (40%), and 3/20 (15%) papillary as well as 5/8 (63%), 5/8 (63%), and 4/8 (50%) unclassified carcinomas, respectively. The two different MUC1 antibodies yielded comparable staining results. A diffuse cytoplasmic staining pattern for MUC1 was found exclusively in chromophobe carcinomas, whereas conventional and papillary subtypes showed predominantly membranous staining (P<0.0001). Regarding papillary carcinomas, MUC1 was predominantly associated with type 1 (P=0.0001), and E-cadherin with type 2 (P=0.049) tumors. The cellular staining pattern of MUC1 in conventional tumors was related to pT-stage (P=0.002) and tumor grade (P=0.001): Low-stage (pT1/pT2) and grade (G1/G2) tumors showed a predominantly apical membranous staining, high-stage (pT3a/pT3b) and grade (G3/G4) tumors a predominantly circumferential membranous staining (with or without additional diffuse cytoplasmic immunoreactivity), which, in the conventional subtype, was associated with poor prognosis (P<0.0001). In conclusion, MUC1 and E-cadherin are diagnostically and prognostically useful markers in renal tumor pathology, especially when cellular staining patterns are considered.

Expression of peanut agglutinin-binding mucin-type glycoprotein in human esophageal squamous cell carcinoma as a marker

Background

The TF (Thomson – Friedenreich) blood group antigen behaves as an onco-foetal carcinoma-associated antigen, showing increased expression in malignancies and its detection and quantification can be used in serologic diagnosis mainly in adenocarcinomas. This study was undertaken to analyze the sera and tissue level detectable mucin-type glycoprotein (TF-antigen) by Peanut agglutinin (PNA) and its diagnostic index in serum as well tissues of human esophageal squamous cell carcinoma as marker.

Results

We examined 100 patients for serological analysis by Enzyme Linked Lectin Assay (ELISA) and demonstrated a sensitivity of 87.5%, specificity of 90% and a positive predictive value of 95%. The immuno-histochemical localization of TF antigen by Fluorescence Antigen Technique (FAT) in 25 specimens of normal esophageal squamous epithelium specimens and 92 specimens with different grades of, allowed a quicker and more precise identification of its increased expression and this did not correlate with gender and tumor size. There was a positive correlation between membrane bound TF antigen expression with different histological progression, from well differentiated to poorly differentiated, determined by PNA binding. Specimens showed morphological changes and a pronounced increase in PNA binding in Golgi apparatus, secretory granules of the cytosol of well differentiated and an increased cell membrane labeling in moderately and poorly differentiated, when compared with ESCC and normal tissues.

Conclusion

The authors propose that the expression of TF-antigen in human may play an important role during tumorigenesis establishing it as a chemically well-defined carcinoma-associated antigen. Identification of the circulating TF-antigen as a reactive form and as a cryptic form in the healthy individuals, using PNA-ELLA and Immunohistochemical analysis of TF antigen by FAT is positively correlated with the different histological grades as a simple and cost-effective method for the early diagnosis of ESCC. The present study reveals that, during tumorigenesis, an aberrant glycosylation takes place in Golgi apparatus leading to over secretion of TF antigen into the cytoplasm along with mucin granules and later into cell membrane. We suggest that the further characterization of TF antigen may unravel pathogenetic aspects of this silent disease.

Phase I immunotherapy with a modified vaccinia virus (MVA) expressing human MUC1 as antigen-specific immunotherapy in patients with MUC1-positive advanced cancer

BACKGROUND

The MUC1 protein is a highly glycosylated mucin normally found at the apical surface of mucin-secreting epithelial cells in many types of tissues. MUC1 is expressed, but heavily underglycosylated, in different human tumors. TG4010 is a viral suspension of a recombinant vaccinia vector (MVA) containing DNA sequences coding for the human MUC1 antigen and interleukin-2 (IL-2). This product was developed for use as a vaccine in cancer patients whose tumors express the MUC1 antigen. The objective of the present study was to determine the safety of the product and to define the dose of TG4010 to be used in further clinical trials.

MATERIALS AND METHODS

Thirteen patients with different solid tumors were treated by repeated intramuscular injection with increasing doses of TG4010 in two separate phase I studies, one in Europe (Basel-CR) and one in the United States (UCLA-RF): a total of 6 patients were treated at a dose of 5 x 10(6) pfu, 3 patients at 5 x 10(7) pfu, and 4 patients at 10(8) pfu. Safety, efficacy, and different immunological tests were the endpoints of the study.

RESULTS

Tolerance of TG4010 was excellent, and side effects mainly consisted of injection site pain and influenza-like symptoms. There was no apparent detrimental effect of repeated injections of the vaccinia virus. Four of thirteen evaluable patients showed stabilization of their disease for 6 to 9 months. One lung cancer patient who was initially progressing after the first injections later showed a marked decrease in the size of his metastases that lasted for 14 months. Some T cell proliferative immune responses were seen in five patients.

CONCLUSIONS

The administration of TG4010 was generally well tolerated in patients with metastatic tumors, and transient disease stabilization was observed in several patients, warranting further clinical studies with the product.

Expression of MUC1 in esophageal squamous-cell carcinoma and its relationship with prognosis of patients from Linzhou city, a high incidence area of northern China

AIM: To further characterize the possible relationship between the molecular changes and prognosis of ESC and to elucidate the possible mechanisms involved.

METHODS: 114 specimens of ESC were collected from Linzhou city, and all patients were followed up for more than 5 years after resection. Histopathological analysis and immunohistochemical staining (ABC) were employed to detect the alteration of MUC1.

RESULTS: The positive immunostaining rate for MUC1 was 79% (90/114), and the high-expression rate was 63% (72/114). The mean survival periods (months) of those with high- and low-expression rates of MUC1 were 41 (95%CI: 35, 47) and 52 (95%CI: 45, 59), respectively. Patients in the low-expression group obviously survived longer than those in high-expression group, and the difference was significant (P < 0.05). The expression of MUC1 protein in the esophageal carcinoma specimens with metastasis was stronger than those without metastasis, the difference was also significant (P < 0.05). The stepwise multivariate analysis showed that “differentiation”, “expression of MUC1” and “TNM staging” were the most important factors affecting the prognosis of esophageal carcinoma patients (P < 0.05).

CONCLUSION: A good correlation between the alteration of MUC1 and the regional lymph node metastasis was observed. Furthermore, high-expression of MUC1 was associated with poor prognosis for esophageal cancer patients. These results indicated that MUC1 is a promising biomarker for predicting lymph node metastasis and prognosis in esophageal cancer.

Mucins in gastrointestinal cancers

The mucin family has been under study by molecular biologists, biochemists, pathologists and immunologists interested in cancer because of the role these molecules can play in the diagnosis and treatment of cancer. Immense knowledge has been accumulated, but the high speed of progress in the laboratory has not been matched by the progress towards applying this knowledge in the clinic. For example, specific knowledge of cancer-associated changes in the expression and glycosylation of various mucins, which can aid in the diagnosis as well as prognosis of GI cancers, has not yet led to the use of a panel of anti-mucin antibodies as a standard diagnostic tool. Similarly, many more opportunities exist for using mucin-based therapies than are currently being considered in the clinic. This chapter aimed to highlight some of these opportunities and to interest clinician scientists in exploring them in the near future.

Expression of MUC1 splice variants in benign and malignant ovarian tumours

MUC1 is expressed on the surface of ovarian cancer cells. Nine different splice variants of MUC1 have been described, but no study has reported on the expression of MUC1 isoforms in human ovarian cancer. Our study compares patterns of expression of MUC1 splice variants of malignant and benign ovarian tumours. Ovarian tissue samples were taken from patients with benign ovarian tumours (n = 34) and from patients who had surgery for primary (n = 47) or recurrent (n = 8) ovarian cancer. RT-PCR for MUC1 splice variants A, B, C, D, X, Y, Z, REP and SEC was performed and their expression compared to clinical and histopathologic parameters. Variants A, D, X, Y and Z were more frequently expressed in malignant than in benign tumours. All primary ovarian cancer cases were positive for variant REP but negative for variant SEC. No significant association of the expression of MUC1 splice variants with the response to chemotherapy or patient survival could be demonstrated. Expression of MUC1 splice variants A, D, X, Y, Z and REP is associated with the presence of malignancy, whereas expression of MUC1/SEC is associated with the absence of malignancy.

Decreased expression of E-cadherin and Yamamoto-Kohama's mode of invasion highly correlates with lymph node metastasis in esophageal squamous cell carcinoma

OBJECTIVES

A reduction in cell-cell adhesion in cancer cells is an essential step in the progression from localized malignancy to metastatic disease. E-Cadherin is an important component of cell-cell adhesion molecules and may be a crucial determinant of tumor invasion and metastasis. E-Cadherin expression is reported to be correlated with lymph node metastasis in esophageal squamous cell carcinoma (SCC). The objective of this experiment is to examine the factors that are associated with invasion and metastasis of esophageal SCC.

METHODS

Forty-six cases of esophageal SCC were examined by immunohistochemical staining for E-cadherin. The relationship between E-cadherin-staining patterns, conventional clinicopathological parameters and Yamamoto-Kohama's (Y-K's) mode of invasion were examined.

RESULTS

The expression of E-cadherin on the cell membrane was reduced or lost in some of the esophageal SCC. Lymph node metastasis was highly correlated with the expression pattern of E-cadherin (p = 0.0002) and also highly correlated with Y-K's mode of invasion (p = 0.0078). However, lymph node metastasis was not correlated with any conventional clinicopathological parameters for invasion.

CONCLUSIONS

These results indicate that E-cadherin plays a crucial role in invasion and metastasis in esophageal SCC, and that Y-K's mode of invasion highly reflects the invasiveness and metastatic potentials of esophageal SCC cells. Therefore, examination of the expression of E-cadherin and Y-K's mode of invasion would be helpful in predicting lymph node metastasis in esophageal SCC.

Patterns of episialin/MUC1 expression in endometrial carcinomas and prognostic relevance

AIMS

To investigate episialin/MUC1 expression in the normal, hyperplastic and neoplastic endometrium, and relate patterns of tumour MUC1 reactivity with histopathological characteristics, oestrogen and progesterone receptor (ER and PR) status, bcl-2 and p53 oncoproteins and with clinical behaviour.

METHODS AND RESULTS

We studied 42 normally cycling endometria, 45 endometrial hyperplasias of various forms, and 111 endometrial carcinomas of endometrioid and non-endometrioid cell types with specific monoclonal antibodies employing standard immunohistochemical techniques. The follow-up period ranged from 34 to 182 months with a median of 86 months. Epithelial mucin episialin/MUC1 was consistently expressed in the normal endometrium, following a cyclical pattern: "apical membrane staining" in early and mid-proliferative endometrium; "purely cytoplasmic staining" in late proliferative endometrium; and "cytoplasmic staining with intraluminal secretions" in secretory endometrium. Immunostaining patterns in simple and complex hyperplasia were similar to late proliferative endometrium, while atypical hyperplasias and endometrial carcinomas either simulated patterns of proliferative endometrium or lacked MUC1 reactivity. Membranous MUC1 positivity was statistically more frequent in endometrioid carcinomas compared with carcinomas of non-endometrioid type (P = 0.006). Cytoplasmic MUC1 positivity was significantly associated with poor prognosis, while MUC1-negative carcinomas were associated with PR expression and an improved survival (P=0.04). There was no association of MUC1 patterns with bcl-2 and p53 immunoreactivity or with other histopathological variables.

CONCLUSIONS

Episialin/MUC1 is an integral component of the normal premenopausal endometrium and is probably hormonally regulated. It is frequently expressed in endometrial hyperplasias and carcinomas. The loss of MUC1 expression from endometrial carcinomas is associated with a favourable prognosis.

MUC1, the renaissance molecule

MUC1 is a large, heavily glycosylated mucin expressed on the apical surfaces of most simple, secretory epithelia including the mammary gland, gastrointestinal, respiratory, urinary and reproductive tracts. Although MUC1 was thought to be an epithelial-specific protein, it is now known to be expressed on a variety of hematopoietic cells as well. Mucins function in protection and lubrication of epithelial surfaces. Transmembrane mucins, which contain cytoplasmic tail domains, appear to have additional functions through their abilities to interact with many proteins involved in signal transduction and cell adhesion. The goal of this review is to highlight recent discoveries that suggest that MUC1 may be a multifunctional protein, located on the surfaces of cells as a sensor of the environment, poised to signal to the interior when things go awry.

Mucin gene expression and cell differentiation in human normal, premalignant and malignant esophagus

Esophageal carcinoma includes squamous cell carcinoma and Barrett's adenocarcinoma. The latter usually develops from a premalignant lesion named Barrett's esophagus. MUC genes are known to be specifically expressed in the normal, premalignant and malignant epithelia of various tissues. The aim of this study was to establish the pattern of MUC gene expression in the esophageal mucosa under normal conditions, and under pathological conditions such as squamous cell carcinoma, Barrett's esophagus and adenocarcinoma. Samples of esophageal control mucosa, metaplastic and malignant tissues were obtained from 40 patients undergoing esophagectomy for squamous cell carcinoma (n = 17), or Barrett's esophagus with adenocarcinoma (n = 23). In situ hybridization and northern blot were used with probes specific for the MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, MUC6 and MUC7 genes to assess their expression in these samples. Submucosal glands of control esophageal mucosa expressed MUC5B, whereas MUC1 and MUC4 were found in both control epithelium and squamous cell carcinoma. MUC4 expression correlated with squamous cell differentiation. Barrett's adenocarcinoma exhibited various patterns of MUC gene expression, the strongest being in the well-differentiated mucinous adenocarcinomas. Barrett's metaplasia was also associated with a specific MUC gene expression pattern, since the gastric apomucin mRNAs, MUC5AC and MUC6, were expressed in gastric metaplasia, and the intestinal apomucin mRNAs, MUC3, MUC4 and mostly MUC2, in intestinal metaplasia. Residual expression of gastric apomucin mRNAs was found in intestinal metaplasia. From these results, we conclude that MUC genes can be considered reliable phenotypic markers of the esophageal cell differentiation, thus providing new insight into the development of Barrett's esophagus.

Enhancement of metastatic properties of pancreatic cancer cells by MUC1 gene encoding an anti-adhesion molecule

MUC1 mucin expression has been shown to be associated clinicopathologically with metastasis and poor clinical outcome in a variety of tumors. To further investigate this finding experimentally, human pancreatic cancer S2-013 cells overexpressing MUC1 were used for spontaneous metastatic potential in nude mice. It was found that the number of lung metastases of MUC1 transfectants was significantly higher than that of control cells. To analyze the molecular mechanisms that underlie the increased metastatic activity, in vitro adhesion assays were performed. MUC1 mucin expression enhancedin vitro invasiveness and motility of S2-013 cells, and decreased the binding of S2-013 cells to type I collagen, Type IV collagen and laminin. Similar effects were not observed for cells expressing tandem repeat-deleted MUC1 cDNA. Adhesion properties were abolished by benzyl-alpha-GalNAc treatment, indicating that glycosylation of the extracellular domain of MUC1 was essential for these biological adhesive functions. Our data support the hypothesis that MUC1 expression contributes to the metastatic ability of pancreatic cancer cells.