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

Deciphering cellular and molecular mechanism of MUC13 mucin involved in cancer cell plasticity and drug resistance

There has been a surge of interest in recent years in understanding the intricate mechanisms underlying cancer progression and treatment resistance. One molecule that has recently emerged in these mechanisms is MUC13 mucin, a transmembrane glycoprotein. Researchers have begun to unravel the molecular complexity of MUC13 and its impact on cancer biology. Studies have shown that MUC13 overexpression can disrupt normal cellular polarity, leading to the acquisition of malignant traits. Furthermore, MUC13 has been associated with increased cancer plasticity, allowing cells to undergo epithelial-mesenchymal transition (EMT) and metastasize. Notably, MUC13 has also been implicated in the development of chemoresistance, rendering cancer cells less responsive to traditional treatment options. Understanding the precise role of MUC13 in cellular plasticity, and chemoresistance could pave the way for the development of targeted therapies to combat cancer progression and enhance treatment efficacy.

The heterogeneity and clonal evolution analysis of the advanced prostate cancer with castration resistance

BACKGROUND

Nowadays, the incidence rate of advanced and metastatic prostate cancer at the first time of diagnosis grows higher in China yearly. At present, androgen deprivation therapy (ADT) is the primary treatment of advanced prostate cancer. However, after several years of ADT, most patients will ultimately progress to castration-resistant prostate cancer (CRPC). Previous studies mainly focus on Caucasian and very few on East Asian patients.

METHODS

In this study, the pre- and post-ADT tumor samples were collected from five Chinese patients with advanced prostate cancer. The whole-exome sequencing, tumor heterogeneity, and clonal evolution pattern were analyzed.

RESULTS

The results showed that the gene mutation pattern and heterogeneity changed significantly after androgen deprivation therapy. Tumor Mutational Burden (TMB) and Copy Number Alteration (CNA) were substantially reduced in the post-treatment group, but the Mutant-allele tumor heterogeneity (MATH), Socio-Demographic Index (SDI), Intratumor heterogeneity (ITH), and weighted Genome Instability Index (wGII) had no significant difference. According to the clone types and characteristics, the presence of main clones in five pre-and post-treatment samples, the clonal evolution pattern can be further classified into two sub-groups (the Homogeneous origin clonal model or the Heterogeneous origin clonal model). The Progression-free survival (PFS) of the patients with the "Homogeneous origin clonal model" was shorter than the "Heterogeneous origin clonal model". The longer PFS might relate to MUC7 and MUC5B mutations repaired. ZNF91 mutation might be responsible for resistance to ADT resistance.

CONCLUSION

Our findings revealed potential genetic regulators to predict the castration resistance and provide insights into the castration resistance processes in advanced prostate cancer. The crosstalk between clonal evolution patterns and tumor microenvironment may also play a role in castration resistance. A multicenter-research including larger populations with different background are needed to confirm our conclusion in the future.

Analysis of MUC6 polymorphisms on the clinicopathologic characteristics of Asian patients with oral squamous cell carcinoma

Head and neck squamous cell carcinomas (HNSCCs) are generally associated with tobacco consumption, alcohol abuse or both. Mucins (MUCs) are high-molecular-weight glycoproteins produced by many epithelial tissues. Many studies have indicated that MUCs play an important role in cancer metastasis. MUC6 expression has been observed in gastric and oncocytic phenotypes and plays an important role during cancer progression. We found that levels of MUC6 are lower in Asian HNCC patients and affect the disease-free survival of HNCC patients. Next, we investigated the combined effect of MUC6 polymorphisms and exposure to environmental carcinogens on the susceptibility to and clinicopathological characteristics of HNCC. Three single-nucleotide polymorphisms (SNPs) of MUC6 (rs7481521, rs6597947 and rs61869016) were analysed using real-time PCR. After adjusting for other co-variants, we found that carrying a CC genotype at MUC6 rs6597947 led to a lower risk of developing oral squamous cell carcinoma (OSCC) than wild-type carriers among non-betel-quid chewers. Moreover, male oral cancer patients who carried the AA + CC genotype at MUC6 rs6597947 had a lower risk of lymph node metastasis than other genotypes, suggesting a significant functional compromise and decompensated disease. Therefore, our findings suggest that genetic variations in MUC6 may correlate to OSCC and indicate the progression in OSCC patients.

Comparison of clinical and pathological features between early-stage gastric-type and intestinal-type differentiated adenocarcinoma: a retrospective study

BACKGROUND

The clinicopathological features and endoscopic characteristics under magnifying endoscopy with narrow band imaging (ME-NBI) between early-stage gastric-type differentiated adenocarcinoma (GDA) and intestinal-type differentiated adenocarcinoma (IDA) remain controversial.

METHODS

Early gastric adenocarcinomas that underwent endoscopic submucosal dissection (ESD) in Nanjing Drum Tower Hospital between August 2017 and August 2021 were included in the present study. GDA cases and IDA cases were selected based on morphology and immunohistochemistry staining of CD10, MUC2, MUC5AC, and MUC6. Clinicopathological data and endoscopic findings in ME-NBI were compared between GDAs and IDAs.

RESULTS

The mucin phenotypes of 657 gastric cancers were gastric (n = 307), intestinal (n = 109), mixed (n = 181) and unclassified (n = 60). No significant difference was observed in terms of gender, age, tumor size, gross type, tumor location, background mucosa, lymphatic invasion, and vascular invasion between patients with GDA and IDA. GDA cases were associated with deeper invasion than IDA cases (p = 0.007). In ME-NBI, GDAs were more likely to exhibit an intralobular loop patten, whereas IDAs were more likely to exhibit a fine network pattern. In addition, the proportion of none-curative resection in GDAs was significantly higher than that in IDAs (p = 0.007).

CONCLUSION

The mucin phenotype of differentiated early gastric adenocarcinoma has clinical significance. GDA was associated with less endoscopically resectability than IDA.

Analysis of MUC6 Genetic Variants on the Clinicopathologic Characteristics of Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the leading malignancy associated with cancer-related deaths worldwide. Many studies have indicated that mucin (MUC) expression plays an important role in cancer metastasis and recurrence. MUC6 expression is observed in gastric and oncocytic phenotypes and may play an important role during cancer progression. We found the level of MUC6 is lower in HCC patients but did not affect the survival of HCC patients. Therefore, in this study, we investigated the combined effect of MUC6 polymorphisms and exposure to environmental carcinogens on the susceptibility to and clinicopathological characteristics of HCC. Three single-nucleotide polymorphisms (SNPs) of MUC6 (rs61869016, rs6597947, and rs7481521) from 1197 healthy controls and 423 HCC patients were analyzed using real-time PCR. After adjusting for other co-variants, we found that carrying a CC genotype at MUC6 rs61869016 had a lower risk of developing HCC than wildtype carriers. Moreover, patients with a smoking habit who carried the C allele of rs61869016 and T allele of rs7481521 had a higher (B or C) Child-Pugh score than other genotypes, suggesting significant functional compromise and decompensated disease. Therefore, our findings suggest that genetic variations in MUC6 may corelate to HCC and indicate progression in HCC patients.

Lactose hydrate can increase the transcellular permeability of β-naphthol in rat jejunum and ileum

BACKGROUND

The unstirred water layer (UWL) is an integral part of the apical surface of mucosal epithelia and comprises mucins (MUC), for which there are many molecular species. Galectins, a family of β-galactoside-binding lectins, form a lattice barrier on surface epithelial cells by interacting with MUC. Lactose inhibits the galectin-MUC interaction. Therefore, the present study investigated the galectin-MUC interaction in the mucosa of the gastrointestinal tract and its role in intestinal barrier functions.

MATERIALS AND RESULTS

The effects of lactose hydrate (LH) on the membrane permeability of the rat small intestine and Caco-2 cells were examined. LH enhanced the membrane permeability of the rat small intestine, which contains the UWL, via a transcellular route, for which the UWL is the rate limiting factor. The membrane permeability of Caco-2 cells, in which the UWL is insufficient, was not affected by LH. The apparent permeability coefficient (P_app) of a paracellular marker was not significantly altered in the rat small intestine or Caco-2 cells treated with LH at any concentration. Furthermore, the P_app of β-naphthol which is a transcellular marker was not significantly altered in Caco-2 cells treated with LH, but was significantly increased in the rat small intestine in a LH concentration-dependent manner.

CONCLUSIONS

The present results demonstrate that the physical barrier has an important function in gastrointestinal membrane permeability, and LH-induced changes increase the transcellular permeability of β-naphthol in rat small intestine.

Whole Exome Sequencing Identifies Two Novel Mutations in a Patient with UC Associated with PSC and SSA

BACKGROUND

Patients diagnosed with ulcerative colitis (UC) associated with primary sclerosis cholangitis (PSC) and sessile serrated adenoma (SSA) are rare. The present study aimed to identify the potential causative gene mutation in a patient with UC associated with PSC and SSA.

METHODS

DNA was extracted from the blood sample and tissue sample of SSA, followed by the whole exome sequencing (WES) analysis. Bioinformatics analysis was utilized to predict the deleteriousness of the identified variants. Multiple sequence alignment and conserved protein domain analyses were performed using online software. Sanger sequencing was used to validate the identified variants. Expression and diagnostic analysis of identified mutated genes was performed in the GSE119600 dataset (peripheral blood samples of PSC and UC) and GSE43841 dataset (tumor samples of SSA).

RESULTS

In the present study, a total of 842 single nucleotide variants (SNVs) in 728 genes were identified in the blood sample. Two variants, integrin beta 4 (ITGB4) (c.C2503G; p.P835A) and a mucin 3A (MUC3A) (c.C1019T; p.P340L), were further analyzed. MUC3A was associated with inflammatory bowel disease. Sanger sequence in blood revealed that the ITGB4 mutation was fully cosegregated with the result of WES in the patient. Additionally, a variant, tumor protein p53 gene (TP53) (c.86delA; p.N29Tfs ^∗ 15) was identified in the tissue sample of SSA. Compared to that in normal controls, ITGB4 was upregulated in both UC and PSC, MUC3A was, respectively, upregulated and downregulated in PSC and UC, and TP53 was downregulated in SSA. ITGB4 and TP53 had a potential diagnostic value for UC, PSC and SSA.

CONCLUSIONS

The present study demonstrated that the ITGB4 (c.C2503G; p.P835A) and MUC3A (c.C1019T; p.P340L) mutations may be the potential causative variants in a patient with UC associated with PSC and SSA. TP53 (c.86delA; p.N29Tfs ^∗ 15) mutation may be associated with SSA in this patient.

Gastric mucin phenotype indicates aggressive biological behaviour in early differentiated gastric adenocarcinomas following endoscopic treatment

Background

The distribution of mucin phenotypes and their relationship with clinicopathological features in early differentiated gastric adenocarcinomas in a Chinese cohort are unknown. We aimed to investigate mucin phenotypes and analyse the relationship between mucin phenotypes and clinicopathological features, especially biological behaviours, in early differentiated gastric adenocarcinomas from endoscopic specimens in a Chinese cohort.

Methods

Immunohistochemical staining of CD10, MUC2, MUC5AC, and MUC6 was performed in 257 tissue samples from patients with early differentiated gastric adenocarcinomas. The tumour location, gross type, tumour size, histological type, depth of invasion, lymphovascular invasion, mucosal background and other clinicopathological parameters were evaluated. The relationship between mucin phenotypes and clinicopathological features was analysed with the chi-square test.

Results

The incidences of gastric, gastrointestinal, intestinal and null phenotypes were 21 %, 56 %, 20 and 3 %, respectively. The mucin phenotypes were related to histology classification (P < 0.05). The proportion of the gastric phenotype became greater during the transition from differentiated to undifferentiated (P < 0.05). Complete intestinal metaplasia was higher in the gastric and intestinal phenotypes than in the gastrointestinal phenotype (P < 0.05). Tumours with poorly differentiated adenocarcinoma were mainly of the gastric phenotype, which was significantly higher than that of purely differentiated tubular adenocarcinoma (P < 0.05), and the depth of invasion in the mixed type was deeper (P < 0.05). Neither recurrence nor metastasis was detected.

Conclusions

The mucin phenotype of early-differentiated gastric adenocarcinoma has clinical implications, and the gastric phenotype has aggressive biological behaviour in early differentiated gastric cancers, especially in those with poorly differentiated adenocarcinoma or papillary adenocarcinoma components.

MUC3A promotes non-small cell lung cancer progression via activating the NFκB pathway and attenuates radiosensitivity

Mucin 3A (MUC3A) is highly expressed in non-small cell lung cancer (NSCLC), but its functions and effects on clinical outcomes are not well understood. Tissue microarray of 92 NSCLC samples indicated that high levels of MUC3A were associated with poor prognosis, advanced staging, and low differentiation. MUC3A knockdown significantly suppressed NSCLC cell proliferation and induced G1/S accumulation via downregulating cell cycle checkpoints. MUC3A knockdown also inhibited tumor growth in vivo and had synergistic effects with radiation. MUC3A knockdown increased radiation-induced DNA double strain breaks and γ-H2AX phosphorylation in NSCLC cells. MUC3A downregulation inhibited the BRCA-1/RAD51 pathway and nucleus translocation of P53 and XCRR6, suggesting that MUC3A promoted DNA damage repair and attenuated radiation sensitivity. MUC3A knockdown also resulted in less nucleus translocation of RELA and P53 in vivo. Immunoprecipitation revealed that MUC3A interacted with RELA and activated the NFκB pathway via promoting RELA phosphorylation and interfering the binding of RELA to IκB. Our studies indicated that MUC3A was a potential oncogene and associated with unfavorable clinical outcomes. NSCLC patients with a high MUC3A level, who should be more frequent follow-up and might benefit less from radiotherapy.

Pathways for the development of multiple epithelial types of intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is categorized into four distinct types: the gastric, intestinal, pancreatobiliary, and oncocytic. Each type is associated with specific clinicopathological features. We aimed to uncover the molecular mechanisms underlying the development of these types of IPMN.

METHODS

We obtained 103 lesions of various types, including 49 gastric, 26 intestinal, 22 pancreatobiliary, and 6 oncocytic lesions, from 43 IPMNs, including 36 with multiple types. Comparative analysis was performed by targeted sequencing of 37 genes in different lesion types within each pancreas.

RESULTS

Gastric-type low-grade lesions were observed in all 36 tumors with multiple types, with 245 mutations identified across all samples. The average number of mutations was significantly different between different lesion grades and types: 1.88 for low-grade lesions, 2.77 for high-grade lesions, and 2.38 for invasive lesions (p = 0.0067); and 1.96 for gastric-type lesion, 2.92 for intestinal-type lesion, 2.73 for pancreatobiliary-type lesion, and 2.17 for oncocytic-type lesion (p = 0.0163). Tracing of mutations between lesions containing multiple types in the same pancreas suggested three developmental pathways, denoted as "progressive", "divergent", and "independent". The progressive and divergent pathways indicate an ancestral lesion that was mostly gastric-type and low-grade may progress or diversify into lesions of other types and/or higher grades. The independent pathway suggests that some high-grade lesions of any type may develop independently.

CONCLUSION

These findings suggest that gastric-type low-grade lesions have a risk of progression into high-grade lesions of other types. Therefore, low-grade gastric-type IPMNs should be under constant surveillance.

Differential MUC22 expression by epigenetic alterations in human lung squamous cell carcinoma and adenocarcinoma

Disruption in mucins (MUCs) is involved in cancer development and metastasis and is thus used as a biomarker. Non‑small cell lung carcinoma (NSCLC) is characterized by heterogeneous genetic and epigenetic alterations. Lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) are the two primary subtypes of NSCLC that require different therapeutic interventions. Here, we report distinct expression and epigenetic alterations in mucin 22 (MUC22), a new MUC family member, in LUSC vs. LUAD. In lung cancer cell lines and tissues, MUC22 was downregulated in LUSC (MUC22Low) but upregulated in LUAD (MUC22High) with co‑expression of MUC21. The aberrant expression of MUC22 was inversely correlated with its promoter hypermethylation in LUSC and hypomethylation in LUAD cells and tissues, respectively. Decreased MUC22 expression in NSCLC cell lines was restored upon treatment with epigenetic modifiers 5‑aza‑2'‑deoxycytidine (5‑Aza) or trichostatin A (TSA), accompanied by reduction in global protein level of histone deacetylase 1 (HDAC1) but increased enrichment of histone H3 lysine 9 acetylation (H3K9ac) specifically in the MUC22 promoter in the SK‑MES‑1 cell line. MUC22 knockdown increased the growth and motility of lung cancer cells and an immortalized human bronchial epithelial BEAS‑2B cell line via NF‑κB activation. Clinically, MUC22Low in LUSC and MUC22High in LUAD were shown to be indicators of unfavorable overall survival for patients with early cancer stages. Our study reveals that changes in MUC22 expression due to epigenetic alterations in NSCLC may have important biological significance and prognostic potential in LUSC when compared to LUAD. Thus, MUC22 expression and epigenetic alterations may be used for molecular subtyping of NSCLC in precision medicine.

Nutrient Digestibility, Growth, Mucosal Barrier Status, and Activity of Leucocytes From Head Kidney of Atlantic Salmon Fed Marine- or Plant-Derived Protein and Lipid Sources

Nutrient digestibility, growth, and mucosal barrier status of fish skin, gills, and distal intestine were studied in Atlantic salmon fed feeds based on marine or plant-derived ingredients. The barrier status was assessed by considering the expression of four mucin genes, five genes that encode antimicrobial proteins, distal intestine micromorphology, and design-based stereology of the midgut epithelium. In addition, the head kidney leukocytes were examined using flow cytometry; to understand the differences in their counts and function. Five experimental feeds containing the main components i) fishmeal and fish oil (BG1), ii) soybean meal (BG2; to induce enteritis), iii) fishmeal as the main protein source and rapeseed oil as the main lipid source (BG3), iv) a mix of plant protein concentrates as the protein sources and fish oil as the lipid source (BG4), and v) plant and marine ingredients in the ratio 70:30 (BG5) were produced for the study. Atlantic salmon with initial weight 72.7 ± 1.2 g was offered the experimental feeds for 65 days. The results revealed that the weights of all fish groups doubled, except for fish fed BG2. Fish fed the BG2 diet had lower blood cholesterol concentration, developed enteritis, had lower expression of muc2 in the distal intestine, and had a compromised barrier status in the intestine. Expression of both the mucin genes and genes that encode antimicrobial peptides were tissue-specific and some were significantly affected by diet. The fish fed BG1 and BG3 had more head kidney lymphocyte-like cells compared to BG5-fed fish, and the phagocytic activity of macrophage-like cells from the head kidney was the highest in fish fed BG1. The intestinal micromorphology and the mucosal mapping suggest two different ways by which plant-based diets can alter the gut barrier status; by either reducing the mucous cell sizes, volumetric densities and barrier status (as noted for BG2) or increasing volumetric density of mucous cells (as observed for BG4 and BG5). The results of the compromised intestinal barrier in fish fed plant ingredients should be further confirmed through transcriptomic and immunohistochemical studies to refine ingredient composition for sustainable and acceptable healthy diets.

Overexpression of MUC16 (CA125) in extramammary Paget's disease

In this study, we identified the mucin-16 (CA125), a well-known disease marker for ovarian cancer, is overexpressed in the lesions of Extramammary Paget’s disease.

The Potential Role and Regulatory Mechanisms of MUC5AC in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is associated with high morbidity and mortality globally. Studies show that airway mucus hypersecretion strongly compromises lung function, leading to frequent hospitalization and mortality, highlighting an urgent need for effective COPD treatments. MUC5AC is known to contribute to severe muco-obstructive lung diseases, worsening COPD pathogenesis. Various pathways are implicated in the aberrant MUC5AC production and secretion MUC5AC. These include signaling pathways associated with mucus-secreting cell differentiation [nuclear factor-κB (NF-κB)and IL-13-STAT6- SAM pointed domain containing E26 transformation-specific transcription factor (SPDEF), as well as epithelial sodium channel (ENaC) and cystic fibrosis transmembrane conductance regulator (CFTR)], and signaling pathways related to mucus transport and excretion-ciliary beat frequency (CBF). Various inhibitors of mucus hypersecretion are in clinical use but have had limited benefits against COPD. Thus, novel therapies targeting airway mucus hypersecretion should be developed for effective management of muco-obstructive lung disease. Here, we systematically review the mechanisms and pathogenesis of airway mucus hypersecretion, with emphasis on multi-target and multi-link intervention strategies for the elucidation of novel inhibitors of airway mucus hypersecretion.

Prognostic value of bone marrow MUC4 expression in acute myeloid leukaemia

Background: Aberrant expression of mucin-4 (MUC4) is present in a variety of solid cancers, but the expression pattern of MUC4 and its clinical relevance in acute myeloid leukaemia (AML) is unknown. We aimed to evaluate the expression level of MUC4 and explore its prognostic value in newly diagnosed adult patients with AML. Methods: Bone marrow from 70 AML patients and 26 healthy donors was obtained. MUC4 levels were quantified by quantitative real-time PCR. Routine blood indices were measured by standard techniques. Results: Bone marrow MUC4 expression levels were significantly elevated in AML patients compared to controls at median (range) 2.77 (0.7-16.6) and 1.14 (0.5-1.99) respectively (p = 0.005). Moreover, lower MUC4 expression was strongly associated with persistent remission (p = 0.001) while higher MUC4 levels were associated with worse overall as well as disease-free survival (p = 0.011 and p = 0.006, respectively). Thus, its level may act as an indicator of disease progression. High MUC4 expression was identified as an independent prognostic predictor for both overall survival and disease-free survival. Conclusion: MUC4 over-expression is an independent predictor of a poor prognosis in AML patients.

MUC15 inhibits cancer metastasis via PI3K/AKT signaling in renal cell carcinoma

Patients with renal cell carcinoma (RCC) often develop distant metastasis and the specific molecular mechanism remains poorly understood. In our study, we demonstrated that MUC15, a subtype of mucins family, could suppress the progression of RCC by inhibiting PI3K/AKT signaling. Firstly, we observed that MUC15 was notably decreased in RCC compared to normal tissue. Furthermore, we showed that MUC15 could negatively modulate the migration and invasion of RCC in vitro and in vivo. Mechanistically, we found that knocking-down of MUC15 could active the PI3K/AKT signaling by increasing the AKT phosphorylation and subsequently increase the mRNA and protein expression of MMP2 and MMP9. Interruption of the AKT pathway with the specific inhibitor LY294002 could reverse the expression of MMPs. Therefore, our study clarify the novel function of MUC15 in RCC, which may provide a new sight to diagnose and prevent RCC metastasis.

Sodium Nitroprusside Enhances Absorption in the Rat Jejunum via the Transcellular Route

It was reported that nitric oxide (NO) donors increased the permeability of water-soluble compounds across intestinal membrane with neither loss of cell viability nor release of lactate dehydrogenase. Therefore, the detail mechanism of action of NO donors on the gastrointestinal membrane has yet to be clarified. We previously reported the possibility of the enhancing effect of the NO donor on the membrane permeability via transcellular route. The purpose of this study is to clarify the mechanism of the membrane permeation-enhancing effect via the transcellular route by sodium nitroprusside (SNP), which is one of the NO donors. The effect of SNP on membrane permeation was examined by the in vitro sac method using rat jejunum. SNP increased the membrane permeation of rhodamine 123 same as using N-acetyl-L-cysteine and dithiothreitol which removes unstirred water layer (UWL). Moreover, SNP increased the membrane permeation of antipyrine and β-naphthol, which are transcellular markers. And it was also investigated the expression levels of mucins (MUCs) which are construction component of UWL and the slight change of MUCs expression by SNP was shown. It was suggested that the expression balance of MUCs is necessary to regulate transcellular permeation, and SNP may affect to UWL. This finding was considered useful for highly lipophilic drugs for which membrane permeation is restricted by the UWL.

The correlation between lncRNAs and Helicobacter pylori in gastric cancer

Helicobacter pylori infection performs a key role in gastric tumorigenesis. Long non-coding RNAs (lncRNAs) have demonstrated a great potential to be regarded as effective malignancy biomarkers for various gastrointestinal diseases including gastric cancer (GC). The present review highlights the relationship between lncRNAs and H. pylori in GC. Several studies have examined not only the involvement of lncRNAs in H. pylori-associated GC progression but also their molecular mechanisms of action. Among the pertinent studies, some have addressed the effects of H. pylori infection on modulatory networks of lncRNAs, while others have evaluated the effects of changes in the expression level of lncRNAs in H. pylori-associated gastric diseases, especially GC. The relationship between lncRNAs and H. pylori was found to be modulated by various molecular pathways.

Systematical Analysis of the Cancer Genome Atlas Database Reveals EMCN/MUC15 Combination as a Prognostic Signature for Gastric Cancer

Digestive cancers-including gastric cancer (GC), colorectal cancer, hepatocellular carcinoma, esophageal cancer, and pancreatic cancer-accounted for 26% of cancer cases and 35% of cancer deaths worldwide in 2018. It is crucial and urgent to develop biomarkers for the diagnosis, prognosis, and therapeutic benefits of digestive cancers, especially for GC, since the incidence of GC is lower only than lung cancer in China, is hard to detect at an early stage, and is associated with poor prognosis. Mucins, glycoproteins encoded by MUC family genes, act as a part of a physical barrier in the digestive tract and participate in various signaling pathways. Some mucins have been used or proposed as biomarkers for carcinomas, such as MUC16 (CA125) and MUC4. However, there are no systematic investigations on the association of MUC family members with diagnoses and clinical outcomes even though relevant data have been largely accumulated in the past decade. By analyzing transcriptomic and clinical data of digestive cancer samples from TCGA involving colon adenocarcinoma (COAD), esophageal carcinoma (ESCA), liver hepatocellular carcinoma (LIHC), stomach adenocarcinoma (STAD), and pancreatic adenocarcinoma (PAAD), it was found that expressions levels of MUC15, MUC13, and MUC21 were individually associated with survival for digestive cancers, and high expressions of EMCN (MUC14) and MUC15 were correlated with poor survival for STAD. Cox regression analysis indicated the predictive power of an EMCN/MUC15 combination for overall survival (OS) of GC patients, which was validated on an independent dataset from GEO. EMCN/MUC15 correlated genes were identified to be enriched in cancer-related processes, such as vasculature development, mitosis, and immunity. Therefore, we propose that an EMCN/MUC15 combination could be a potential prognostic signature for gastric cancer.

Peripheral immune-based biomarkers in cancer immunotherapy: can we realize their predictive potential?

The immunologic landscape of the host and tumor play key roles in determining how patients will benefit from immunotherapy, and a better understanding of these factors could help inform how well a tumor responds to treatment. Recent advances in immunotherapy and in our understanding of the immune system have revolutionized the treatment landscape for many advanced cancers. Notably, the use of immune checkpoint inhibitors has demonstrated durable responses in various malignancies. However, the response to such treatments is variable and currently unpredictable, the availability of predictive biomarkers is limited, and a substantial proportion of patients do not respond to immune checkpoint therapy. Identification and investigation of potential biomarkers that may predict sensitivity to immunotherapy is an area of active research. It is envisaged that a deeper understanding of immunity will aid in harnessing the full potential of immunotherapy, and allow appropriate patients to receive the most appropriate treatments. In addition to the identification of new biomarkers, the platforms and assays required to accurately and reproducibly measure biomarkers play a key role in ensuring consistency of measurement both within and between patients. In this review we discuss the current knowledge in the area of peripheral immune-based biomarkers, drawing information from the results of recent clinical studies of a number of different immunotherapy modalities in the treatment of cancer, including checkpoint inhibitors, bispecific antibodies, chimeric antigen receptor T cells, and anti-cancer vaccines. We also discuss the various technologies and approaches used in detecting and measuring circulatory biomarkers and the ongoing need for harmonization.

Two Opposing Faces of Retinoic Acid: Induction of Stemness or Induction of Differentiation Depending on Cell-Type

Stem cells have the capacity of self-renewal and, through proliferation and differentiation, are responsible for the embryonic development, postnatal development, and the regeneration of tissues in the adult organism. Cancer stem cells, analogous to the physiological stem cells, have the capacity of self-renewal and may account for growth and recurrence of tumors. Development and regeneration of healthy tissues and tumors depend on the balance of different genomic and nongenomic signaling pathways that regulate stem cell quiescence, proliferation, and differentiation. During evolution, this balance became dependent on all-trans retinoic acid (RA), a molecule derived from the environmental factor vitamin A. Here we summarize some recent findings on the prominent role of RA on the proliferation of stem and progenitor cells, in addition to its well-known function as an inductor of cell differentiation. A better understanding of the regulatory mechanisms of stemness and cell differentiation by RA may improve the therapeutic options of this molecule in regenerative medicine and cancer.

Mucins: the Old, the New and the Promising Factors in Hepatobiliary Carcinogenesis

Mucins are large O-glycoproteins with high carbohydrate content and marked diversity in both the apoprotein and the oligosaccharide moieties. All three mucin types, trans-membrane (e.g., MUC1, MUC4, MUC16), secreted (gel-forming) (e.g., MUC2, MUC5AC, MUC6) and soluble (non-gel-forming) (e.g., MUC7, MUC8, MUC9, MUC20), are critical in maintaining cellular functions, particularly those of epithelial surfaces. Their aberrant expression and/or altered subcellular localization is a factor of tumour growth and apoptosis induced by oxidative stress and several anti-cancer agents. Abnormal expression of mucins was observed in human carcinomas that arise in various gastrointestinal organs. It was widely believed that hepatocellular carcinoma (HCC) does not produce mucins, whereas cholangiocarcinoma (CC) or combined HCC-CC may produce these glycoproteins. However, a growing number of reports shows that mucins can be produced by HCC cells that do not exhibit or are yet to undergo, morphological differentiation to biliary phenotypes. Evaluation of mucin expression levels in precursors and early lesions of CC, as well as other types of primary liver cancer (PLC), conducted in in vitro and in vivo models, allowed to discover the mechanisms of their action, as well as their participation in the most important signalling pathways of liver cystogenesis and carcinogenesis. Analysis of mucin expression in PLC has both basic research and clinical value. Mucins may act as oncogenes and tumour-promoting (e.g., MUC1, MUC13), and/or tumour-suppressing factors (e.g., MUC15). Given their role in promoting PLC progression, both classic (MUC1, MUC2, MUC4, MUC5AC, MUC6) and currently tested mucins (e.g., MUC13, MUC15, MUC16) have been proposed to be important diagnostic and prognostic markers. The purpose of this review was to summarize and update the role of classic and currently tested mucins in pathogenesis of PLC, with explaining the mechanisms of their action in HCC carcinogenesis. It also focuses on determination of the diagnostic and prognostic role of these glycoproteins in PLC, especially focusing on HCC, CC and other hepatic tumours with- and without biliary differentiation.

Bromelain inhibits the ability of colorectal cancer cells to proliferate via activation of ROS production and autophagy

Advanced colorectal cancer (CRC) survival rates are still low despite advances in cytotoxic and targeted therapies. The development of new effective or alternative therapies is therefore urgently needed. Bromelain, an extract of pineapple, was shown to have anticancer effects, but its mechanisms in CRC have not been fully explored. Therefore, the roles of bromelain in CRC progression were investigated using different CRC cell lines, a zebrafish model, and a xenograft mouse model. The anticancer mechanisms were explored by assessing the role of bromelain in inducing reactive oxygen species (ROS), superoxide, autophagosomes, and lysosomes. The role of bromelain in the induction of apoptosis was also assessed. It was found that bromelain inhibited CRC cell growth in cell lines and tumor growth in the zebrafish and xenograft mouse models. It also induced high levels of ROS and superoxide, plus autophagosome and lysosome formation. High levels of apoptosis were also induced, which were associated with elevated amounts of apoptotic proteins like apoptotic induction factor, Endo G, and caspases-3, -8, and -9 according to a qPCR analysis. In a Western blot analysis, increases in levels of ATG5/12, beclin, p62, and LC3 conversion rates were found after bromelain treatment. Levels of cleaved caspase-3, caspase-8, caspase-9, and poly(ADP ribose) polymerase (PARP)-1 increased after bromelain exposure. This study explored the role of bromelain in CRC while giving insights into its mechanisms of action. This compound can offer a cheap alternative to current therapies.

Integrative analysis of the cancer genome atlas and cancer cell lines encyclopedia large-scale genomic databases: MUC4/MUC16/MUC20 signature is associated with poor survival in human carcinomas

BACKGROUND

MUC4 is a membrane-bound mucin that promotes carcinogenetic progression and is often proposed as a promising biomarker for various carcinomas. In this manuscript, we analyzed large scale genomic datasets in order to evaluate MUC4 expression, identify genes that are correlated with MUC4 and propose new signatures as a prognostic marker of epithelial cancers.

METHODS

Using cBioportal or SurvExpress tools, we studied MUC4 expression in large-scale genomic public datasets of human cancer (the cancer genome atlas, TCGA) and cancer cell line encyclopedia (CCLE).

RESULTS

We identified 187 co-expressed genes for which the expression is correlated with MUC4 expression. Gene ontology analysis showed they are notably involved in cell adhesion, cell-cell junctions, glycosylation and cell signaling. In addition, we showed that MUC4 expression is correlated with MUC16 and MUC20, two other membrane-bound mucins. We showed that MUC4 expression is associated with a poorer overall survival in TCGA cancers with different localizations including pancreatic cancer, bladder cancer, colon cancer, lung adenocarcinoma, lung squamous adenocarcinoma, skin cancer and stomach cancer. We showed that the combination of MUC4, MUC16 and MUC20 signature is associated with statistically significant reduced overall survival and increased hazard ratio in pancreatic, colon and stomach cancer.

CONCLUSIONS

Altogether, this study provides the link between (i) MUC4 expression and clinical outcome in cancer and (ii) MUC4 expression and correlated genes involved in cell adhesion, cell-cell junctions, glycosylation and cell signaling. We propose the MUC4/MUC16/MUC20^high signature as a marker of poor prognostic for pancreatic, colon and stomach cancers.

Immunohistochemical expression profiles of MUC1 and MUC2 mucins in urothelial tumors of bladder

Background

Mucins may show aberrant expression, localization, and/or glycosylation in multiple malignancies. However, information regarding expression of these mucins is mostly unknown in urothelial tumors.

Aim

This study was conducted for examining the expressions of membrane associated and secreted mucin (MUC1) and a secreted gel-forming mucin (MUC2) in urothelial tumors of the urinary bladder.

Subjects and Methods

Archival transurethral resection materials of 97 urothelial carcinoma cases were reexamined light microscopically and graded according to the 2004 WHO Classification. Pathological stage was given as pTa, pT1, and pT2. Demonstrative sections were recut for immunohistochemistry for MUC1 and MUC2. The results were statistically analyzed, and P < 0.05 was considered statistically significant.

Results

The positivity for MUC1 and MUC2 was 89.7% and 44.3%, respectively. Independent from pathological stage of the tumor, MUC1 expression showed statistically significant correlation with tumor grade (P < 0.05). We did not find any correlation between pathological stage and MUC1 and MUC2 expression (P > 0.05). MUC1 staining pattern in papillary urothelial neoplasm of low malignant potential cases was more commonly apical and superficial (luminal cell layer only). Intermediate cells ± basal cells or isolated cells or islands of tumor cells with cytoplasmic and/or circumferential membrane positivity for MUC1 and MUC2 were more commonly observed in both low- and high-grade carcinomas. The difference between groups in terms of MUC1 and MUC2 staining was statistically significant (P < 0.05).

Conclusions

The staining patterns of both mucins are different between urothelial papillary tumors and may be used to make a differentiation, especially for low-grade papillary urothelial lesions. This difference may also be important in the carcinomatous transformation of urothelial neoplastic and preneoplastic lesions.

Helicobacter pylori infection related long noncoding RNA (lncRNA) AF147447 inhibits gastric cancer proliferation and invasion by targeting MUC2 and up-regulating miR-34c

Long non-coding RNAs (lncRNAs) were shown to play critical roles in cancer biology. We investigated whether H. pylori infection could promote gastric cancer by regulating lncRNAs expression. Differentially expressed lncRNAs between H. pylori positive and negative tissues were identified by microarray and validated by qRT-PCR. Our results indicated that H. pylori positive tissues have a specific profile of lncRNAs. Cell biological assays with siRNA-mediated knockdown or lentivirus vector-mediated over-expression were performed to probe the functional relevance of the lncRNAs. We identified an lncRNA-AF147447 decreased expressed by H. pylori infection, which can inhibit GC proliferation and invasion in vitro and in vivo, act as a tumor suppressor in the development of H. pylori induced GC. LncRNA AF147447 could repress MUC2 expression by direct binding or increasing miR-34c expression. We also found that transcription factor E2F1 could be recruited to lncRNA AF147447 promoter by RNA immunoprecipatation and RNA pull down assays. These findings support a role of lncRNA AF147447 in tumor suppression. This discovery contributes to a better understanding of the importance of the deregulated lncRNAs by H. pylori infection and provides a rationale for the potential development of lncRNA-based targeted approaches for the treatment of H. pylori-related gastric cancer.

Helicobacter pylori infection related long noncoding RNA (lncRNA) AF147447 inhibits gastric cancer proliferation and invasion by targeting MUC2 and up-regulating miR-34c

Long non-coding RNAs (lncRNAs) were shown to play critical roles in cancer biology. We investigated whether H. pylori infection could promote gastric cancer by regulating lncRNAs expression. Differentially expressed lncRNAs between H. pylori positive and negative tissues were identified by microarray and validated by qRT-PCR. Our results indicated that H. pylori positive tissues have a specific profile of lncRNAs. Cell biological assays with siRNA-mediated knockdown or lentivirus vector-mediated over-expression were performed to probe the functional relevance of the lncRNAs. We identified an lncRNA-AF147447 decreased expressed by H. pylori infection, which can inhibit GC proliferation and invasion in vitro and in vivo, act as a tumor suppressor in the development of H. pylori induced GC. LncRNA AF147447 could repress MUC2 expression by direct binding or increasing miR-34c expression. We also found that transcription factor E2F1 could be recruited to lncRNA AF147447 promoter by RNA immunoprecipatation and RNA pull down assays. These findings support a role of lncRNA AF147447 in tumor suppression. This discovery contributes to a better understanding of the importance of the deregulated lncRNAs by H. pylori infection and provides a rationale for the potential development of lncRNA-based targeted approaches for the treatment of H. pylori-related gastric cancer.

Increased expression of MUC3A is associated with poor prognosis in localized clear-cell renal cell carcinoma

MUC3A is a membrane-associated mucin that recent evidence reveals the role of MUC3A in pathogenesis and progression of cancers. To evaluate the association between MUC3A expression with overall survival (OS) and recurrence-free survival (RFS) in patients with localized clear-cell renal cell carcinoma (ccRCC), we retrospectively detected MUC3A expression in samples of 384 postoperative localized ccRCC patients by immunohistochemistry. Median follow-up was 73 months (range: 42 – 74 mo). Overall, 41 patients died, 47 experienced recurrence. High MUC3A expression occurred in 45.8% of localized ccRCC cases, which was significantly associated with high pT-stage, high Fuhrman grade, high frequency of necrosis and LVI, and increased risk of recurrence and death (Logrank test P < 0.001 and P < 0.001, respectively). By multivariate analysis, MUC3A expression was confirmed as an adverse independent prognostic factor for OS and RFS. The prognostic accuracy of UISS, SSIGN, Leibovich models was significantly increased when MUC3A expression was integrated. Meanwhile, MUC3A was enrolled into a newly built nomogram with other factors selected by multivariate analysis. Calibration curves revealed optimal consistency between observations and prognosis. In conclusion, high MUC3A expression is an adverse prognostic biomarker for OS and RFS in postoperative localized ccRCC patients.

Aberrant methylation of MUC1 and MUC4 promoters are potential prognostic biomarkers for pancreatic ductal adenocarcinomas

Pancreatic cancer is still a disease of high mortality despite availability of diagnostic techniques. Mucins (MUC) play crucial roles in carcinogenesis and tumor invasion in pancreatic neoplasms. MUC1 and MUC4 are high molecular weight transmembrane mucins. These are overexpressed in many carcinomas, and high expression of these molecules is a risk factor associated with poor prognosis. We evaluated the methylation status of MUC1 and MUC4 promoter regions in pancreatic tissue samples from 169 patients with various pancreatic lesions by the methylation specific electrophoresis (MSE) method. These results were compared with expression of MUC1 and MUC4, several DNA methylation/demethylation factors (e.g. ten-eleven translocation or TET, and activation-induced cytidine deaminase or AID) and CAIX (carbonic anhydrase IX, as a hypoxia biomarker). These results were also analyzed with clinicopathological features including time of overall survival of PDAC patients. We show that the DNA methylation status of the promoters of MUC1 and MUC4 in pancreatic tissue correlates with the expression of MUC1 and MUC4 mRNA. In addition, the expression of several DNA methylation/demethylation factors show a significant correlation with MUC1 and MUC4 methylation status. Furthermore, CAIX expression significantly correlates with the expression of MUC1 and MUC4. Interestingly, our results indicate that low methylation of MUC1 and/or MUC4 promoters correlates with decreased overall survival. This is the first report to show a relationship between MUC1 and/or MUC4 methylation status and prognosis. Analysis of epigenetic changes in mucin genes may be of diagnostic utility and one of the prognostic predictors for patients with PDAC.

Identification of genes highly downregulated in pancreatic cancer through a meta-analysis of microarray datasets: implications for discovery of novel tumor-suppressor genes and therapeutic targets

PURPOSE

The lack of specific symptoms at early tumor stages, together with a high biological aggressiveness of the tumor contribute to the high mortality rate for pancreatic cancer (PC), which has a 5-year survival rate of about 7%. Recent failures of targeted therapies inhibiting kinase activity in clinical trials have highlighted the need for new approaches towards combating this deadly disease.

METHODS

In this study, we have identified genes that are significantly downregulated in PC, through a meta-analysis of large number of microarray datasets. We have used qRT-PCR to confirm the downregulation of selected genes in a panel of PC cell lines.

RESULTS

This study has yielded several novel candidate tumor-suppressor genes (TSGs) including GNMT, CEL, PLA2G1B and SERPINI2. We highlight the role of GNMT, a methyl transferase associated with the methylation potential of the cell, and CEL, a lipase, as potential therapeutic targets. We have uncovered genetic links to risk factors associated with PC such as smoking and obesity. Genes important for patient survival and prognosis are also discussed, and we confirm the dysregulation of metabolic pathways previously observed in PC.

CONCLUSIONS

While many of the genes downregulated in our dataset are associated with protein products normally produced by the pancreas for excretion, we have uncovered some genes whose downregulation appear to play a more causal role in PC. These genes will assist in providing a better understanding of the disease etiology of PC, and in the search for new therapeutic targets and biomarkers.

Cell membrane-anchored MUC4 promotes tumorigenicity in epithelial carcinomas

The cell surface membrane-bound mucin protein MUC4 promotes tumorigenicity, aggressive behavior, and poor outcomes in various types of epithelial carcinomas, including pancreatic, breast, colon, ovarian, and prostate cancer. This review summarizes the theories and findings regarding MUC4 function, and its role in epithelial carcinogenesis. Based on these insights, we developed an outline of the processes and mechanisms by which MUC4 critically supports the propagation and survival of cancer cells in various epithelial organs. MUC4 may therefore be a useful prognostic and diagnostic tool that improves our ability to eradicate various forms of cancer.

Clinicopathological features of intraductal papillary neoplasms of the bile duct: a comparison with intraductal papillary mucinous neoplasm of the pancreas with reference to subtypes

Intraductal papillary epithelial neoplasms of the pancreatobiliary system (intraductal papillary neoplasm of the bile duct (IPNB) and intraductal papillary mucinous neoplasm (IPMN)) seem to share many clinicopathological features; however, IPNB has not been fully characterized. In order to understand the clinicopathological/immunohistochemical features of IPNB better, we compared 52 cases of IPNB with 42 cases of IPMNs with mural nodules. The IPNB cases were divided into two groups according to their histological similarity and according to five key histological findings. All IPNB and IPMN cases mainly affected middle-aged to elderly people, predominantly men. Mucin hypersecretion was less frequent in IPNB compared to IPMN. Group 2 IPNB more frequently had a higher histopathological grade and more extensive stromal invasion than IPMN. Group 1 IPNB and IPMN were further classified into four subtypes (gastric, intestinal, pancreatobiliary, and oncocytic). Although each subtype of IPNB and IPMN showed similar histology, the immunohistochemical results were different. The gastric type of IPNB was less frequently positive for CDX2, and intestinal IPNB was more frequently positive for MUC1 and less frequently positive for MUC2, MUC5AC, and CDX2 compared to each subtype of IPMN, respectively. In conclusion, IPNB and IPMN have some clinicopathological features in common, but mucin hypersecretion was less frequent both in IPNBs than in IPMN. Group 2 IPNB differed from IPMN in several parameters of tumor aggressiveness. Additional clinicopathological and molecular studies should be performed with respect to the subtypes of IPNB and IPMN.

High mucin 5AC expression predicts adverse postoperative recurrence and survival of patients with clear-cell renal cell carcinoma

Background

Mucin 5AC (MUC5AC), as a member of secreted/gel-forming mucin family, was frequently found to be abnormally expressed in inflammation or malignant diseases. However, the clinic pathologic features and prognostic values of MUC5AC in clear-cell renal cell carcinoma (ccRCC) have not been reported up to now.

Methods

MUC5AC expression was analyzed by immunohistochemistry on tissue microarrays. Kaplan-Meier survival curves, Univariate and Multivariate Cox analysis and newly-established nomogram model were performed to evaluate the prognostic value.

Results

MUC5AC expression was firstly found to be up-regulated in patients with ccRCC, positively associated with tumor size, pN stage, lymphovascular invasion, Fuhrman grade, rahbdoid differentiation, sarcomatoid features, tumor necrosis, ECOG-PS and recurrence. Furthermore, MUC5AC expression might be contributed to risk stratification of ccRCC patients with TNM stage III+IV or Fuhrman grade 3 or 4 for overall survival (OS) and recurrence-free survival (RFS) analysis, and it was demonstrated to be negatively correlated with OS and RFS of ccRCC patients. What's more, MUC5AC was identified as a potential independent adverse prognostic factor; prediction accuracy of MUC5AC-based new nomogram model was drastically improved for OS and RFS of ccRCC patients.

Conclusion

MUC5AC is a promising independent adverse prognostic factor for ccRCC patients, it maybe conducive to postoperative risk stratification and guide treatment in the future.

Predictive biomarkers and effectiveness of MUC1-targeted dendritic-cell-based vaccine in patients with refractory non-small cell lung cancer

BACKGROUND

The dendritic cell (DC)-based vaccine targeting the highly immunogenic tumor antigen, MUC1, has been promising for a cancer immunotherapy; however, predictive biomarkers for beneficial clinical responses of the vaccine remain to be determined.

METHODS

DCs loaded with MUC1-derived peptide were subcutaneously administered to patients with MUC1-positive non-small cell lung cancer (NSCLC) that was refractory to standard anticancer therapies, every 2 weeks. The effectiveness and tolerability of the vaccine were evaluated, and predictive biomarkers of clinical responses were explored.

RESULTS

Between August 2005 and May 2015, 40 patients received the vaccines. The median survival time (MST) after the initial vaccination was 7.4 months, and the 1-year survival rate was 25.0%. The MST for patients who received more than six vaccinations was 9.5 months, and the 1-year survival rate was 39.3%. In this cohort, patients who experienced immune-related adverse events, including skin reactions at the vaccination site and fever, had significantly longer survival times compared with patients without those immune-related adverse events (12.6 versus 6.7 months, p = 0.042). Longer survival times were also observed in patients whose peripheral white blood cells contained >20.0% lymphocytes (12.6 versus 4.5 months; p = 0.014). MUC1-specific cytotoxic immune responses were achieved in all of seven patients analyzed who received six vaccinations.

CONCLUSION

The MUC1-targeted DC-based vaccine induced an antitumor immune response that promoted prolonged survival of patients with refractory NSCLC. The occurrence of immune-related adverse events and having a higher percentage of peripheral lymphocytes were predictive biomarkers of a beneficial clinical response during cancer immunotherapy for NSCLC.

Abrogation of MUC5AC Expression Contributes to the Apoptosis and Cell Cycle Arrest of Colon Cancer Cells

Deregulated expressions of mucins have been found in various malignancies and play a pivotal role in carcinogenesis. MUC5AC, as a secreted mucin, is reported to be aberrantly expressed during epithelial cancer progression, including colon cancer. However, the mechanisms of the oncoprotein MUC5AC in the initiation of colon cancer requires further investigation. Here, we collected colon cancer tissues (n = 20) and corresponding paracancerous tissues (n = 20) and found that the expression of MUC5AC was significantly elevated in colon cancer tissues when compared with the corresponding paracancerous tissues. Immunofluorescence indicated that all colon cancer cell lines, including HT29, SW620, and the normal human intestinal epithelial cells FHC, showed the positive expression of MUC5AC, and SW620 exhibited the highest expression. Moreover, knockdown of MUC5AC in SW620 cells remarkably suppressed cell vitality and promoted apoptosis and G1 cell cycle arrest, resulting in the impaired ability of colony formation. Furthermore, the inhibition of MUC5AC in SW620 cells dramatically repressed the cell migration and invasion. These results demonstrated that MUC5AC as an oncogene could be a promising target in the treatment of colon cancer.

Gastric Proteins MUC5AC and TFF1 as Potential Diagnostic Markers of Colonic Sessile Serrated Adenomas/Polyps

OBJECTIVES

A subset of colon cancers originates from sessile serrated adenomas/polyps (SSA/Ps). Our goal was to identify markers for SSA/Ps that could aid in distinguishing them from hyperplastic polyps (HPs).

METHODS

We performed immunostaining for gastric proteins MUC5AC and TFF1 in formalin-fixed, paraffin-embedded (FFPE) samples of HPs (n = 47), SSA/Ps (n = 37), and normal colon (n = 30).

RESULTS

Control mucosa expressed only trace amounts of MUC5AC and TFF1. HPs exhibited an 11.3- and 11.4-fold increase in MUC5AC and TFF1 expression confined to the upper segments of the crypts near the luminal surface of the polyps. SSA/Ps displayed on average 1.6-fold (MUC5AC, P  < .008) and 1.4-fold (TFF1, P  < .03) higher signal intensity for these markers than HPs, with a dramatic coexpression of MUC5AC and TFF1 typically occupying the entire length of the crypt. Immunoperoxidase results were similar to immunofluorescence staining for both MUC5AC and TFF1.

CONCLUSIONS

Our results suggest that the analysis of expression of MUC5AC and TFF1 may be useful for differentiating SSA/Ps from HPs. We also suggest the possibility that crypt morphology may be at least partly due to overproduction of highly viscous gastric mucins and that these proteins may play a role in the serrated pathway to colon carcinogenesis.

Polymorphisms in microRNA binding sites of mucin genes as predictors of clinical outcome in colorectal cancer patients

Polymorphisms in microRNA (miRNA) binding sites may affect miRNA/target gene interaction, resulting in differential mRNA/protein expression and susceptibility to common diseases. Mucins have been identified as markers of adverse prognosis. We hypothesized that genetic variations in miRNA binding sites located in mucin genes may modulate signaling response and the maintenance of genomic stability ultimately affecting cancer susceptibility, efficacy of chemotherapy and survival. In this study, we analyzed the association of single nucleotide polymorphisms in predicted miRNA target sites (miRSNPs) of mucin genes with colorectal cancer (CRC) risk and clinical outcome. Thirteen miRSNPs in 9 genes were assessed in 1111 cases and 1469 controls. No strongly significant associations were observed in the case-control study. Patients carrying the CC genotype of rs886403 in MUC21 displayed a shorter survival and higher recurrence risk when compared with TT carriers [overall survival (OS): hazard ratios (HR) 1.69; 95% confidence intervals (CI) 1.13-2.46; P = 0.01 and event-free survival (EFS): HR 1.99; 95% CI 1.38-2.84; P = 0.0002, respectively]. The observed associations were more striking after stratification for tumor site (in patients with colon cancer, OS: HR 2.63; 95% CI 1.69-4.10; P < 0.0001 and EFS: HR 2.65; 95% CI 1.72-4.07; P < 0.0001). In contrast, rectal cancer cases carrying the CC genotype of rs4729655 in MUC17 displayed a longer survival (OS: HR 0.27; 95% CI 0.14-0.54; P = 0.0002) than those with the most common genotype. To our knowledge, this is the first study investigating miRSNPs potentially affecting miRNA binding to mucin genes and revealing their impact on CRC susceptibility or patient's survival.

Intraductal Tubulopapillary Neoplasm of the Pancreas Masquerading as Pancreatic Neuroendocrine Carcinoma: Review of the Literature with a Case Report

BACKGROUND

Intraductal tubulopapillary neoplasm of the pancreas (ITPN) is a rare tumor which was first described in 2009. We report a case with cytologic and histologic findings and discuss the pitfalls in diagnosing this entity on cytology.

CASE

An 82-year-old female presented with a pancreatic body mass measuring 3.3 cm. Endoscopic ultrasound-guided fine-needle aspiration showed cells in cohesive clusters with high-grade nuclear atypia. Immunohistochemistry (IHC) showed the neoplastic cells to be positive for CK19, CD56 and chromogranin (focal). Ki-67 was high at 50-60%, and chymotrypsin was negative. On the basis of this pattern of staining, the cytologic diagnosis rendered was 'favors high-grade neuroendocrine carcinoma'. Distal pancreatic resection revealed a cystic 4-cm mass. Histologically, the tumor was seen arising from the duct with a solid growth pattern, tubule formation and papillary structures. IHC showed the tumor to be negative for chromogranin, synaptophysin, CD56, trypsin and chymotrypsin. The Ki-67 index was 70%. The final diagnosis was noninvasive ITPN.

CONCLUSION

We review the literature and discuss the cytomorphologic features and IHC patterns characteristic of this new entity on cytology material in addition to the pitfalls of the cytologic diagnosis.

Low Expression of Mucin-4 Predicts Poor Prognosis in Patients With Clear-Cell Renal Cell Carcinoma

Mucin-4 (MUC4), a member of membrane-bound mucins, has been reported to exert a large variety of distinctive roles in tumorigenesis of different cancers. MUC4 is aberrantly expressed in clear-cell renal cell carcinoma (ccRCC) but its prognostic value is still unveiled. This study aims to assess the clinical significance of MUC4 expression in patients with ccRCC.The expression of MUC4 was assessed by immunohistochemistry in 198 patients with ccRCC who underwent nephrectomy retrospectively in 2003 and 2004. Sixty-seven patients died before the last follow-up in the cohort. Kaplan-Meier method with log-rank test was applied to compare survival curves. Univariate and multivariate Cox regression models were applied to evaluate the prognostic value of MUC4 expression in overall survival (OS). The predictive nomogram was constructed based on the independent prognostic factors. The calibration was built to evaluate the predictive accuracy of nomogram.In patients with ccRCC, MUC4 expression, which was determined to be an independent prognostic indicator for OS (hazard ratio [HR] 3.891; P < 0.001), was negatively associated with tumor size (P = 0.036), Fuhrman grade (P = 0.044), and OS (P < 0.001). The prognostic accuracy of TNM stage, UCLA Integrated Scoring System (UISS), and Mayo clinic stage, size, grade, and necrosis score (SSIGN) prognostic models was improved when MUC4 expression was added. The independent prognostic factors, pT stage, distant metastases, Fuhrman grade, sarcomatoid, and MUC4 expression were integrated to establish a predictive nomogram with high predictive accuracy.MUC4 expression is an independent prognostic factor for OS in patients with ccRCC.

Tumour-associated antigens and their anti-cancer applications

So far, a number of tumour-associated antigens (TAAs), such as heat shock proteins, alpha-fetoprotein, carcino-embryonic antigen and others have been identified in a variety of malignant tumours. Differences in the expression levels of TAAs in cancers compared with normal cells have led to these antigens being investigated as diagnostic and prognostic biomarkers or exciting targets in cancer treatment. Here, we systematically list the current representative TAAs to shed some light on current approaches and challenges for their anti-cancer application in cancer therapy. In this review, we discuss the ongoing pre-clinical studies and clinical development of TAAs in human cancers, and the potential application of these TAAs in the diagnosis and prognosis for cancer treatment.

A case of MUC5AC-positive intraductal neoplasm of the pancreas classified as an intraductal tubulopapillary neoplasm?

This report describes a unique case of intraductal tubulopapillary neoplasm (ITPN) of the pancreas in order to clarify its oncogenesis and more precisely classify pancreatic intraductal neoplasms. A 74-year-old man visited our institution for follow-up of acute pancreatitis. Imaging examinations revealed a hypovascular intraductal mass in the head of the pancreas with progressive dilation of the pancreatic duct, atrophy of the pancreatic parenchyma, and a non-mucinous appearance. A pancreatoduodenectomy was performed to identify this pancreatic intraductal neoplasm. Macroscopically, the tumor was a solid nodular mass with no visibly secreted mucin obstructing the dilated ducts. Histologically, it had a homogeneous appearance with nodules of back-to-back tubular glands and occasional papillary elements, and there were no apparent transitions to areas with less marked cytoarchitectural atypia. Although the intraductal neoplastic growth corresponded to an ITPN, immunohistochemical staining revealed partial positivity for MUC5AC, for which ITPNs are characteristically negative. Somatic mutations in KRAS, GNAS, BRAF, and PIK3CA were not detected. A loss of MUC5AC expression and mutations in KRAS and GNAS are key elements in the diagnosis of ITPN. Thus, it was difficult to distinguish the present case as a pancreatobiliary-type (PB-type) intraductal papillary mucinous neoplasm (IPMN) or a phenotypic variant of ITPN. As it is possible that some cases of PB-type IPMN and ITPN overlap, the precise classification of these rare lesions may require re-evaluation.

Mucin expression in endoscopic ultrasound-guided fine-needle aspiration specimens is a useful prognostic factor in pancreatic ductal adenocarcinoma

OBJECTIVES

The aim of this study was to further examine the utility of mucin (MUC) expression profiles as prognostic factors in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Mucin expression was examined by immunohistochemistry analysis in endoscopic ultrasound-guided fine-needle aspiration specimens obtained from 114 patients with PDAC. The rate of expression of each MUC was compared with clinicopathologic features.

RESULTS

The expression rates of MUCs in cancer lesions were MUC1, 87.7%; MUC2, 0.8%; MUC4, 93.0%; MUC5AC, 78.9%; MUC6, 24.6%; and MUC16, 67.5%. MUC1 and MUC4 were positive, and MUC2 was negative in most PDACs. Patients with advanced stage of PDAC with MUC5AC expression had a significantly better outcome than those who were MUC5AC-negative (P = 0.002). With increasing clinical stage, total MUC6 expression decreased (P for trend = 0.001) and MUC16 cytoplasmic expression increased (P for trend = 0.02). The prognosis of patients with MUC16 cytoplasmic expression was significantly poorer than those without this expression. Multivariate survival analysis revealed that MUC16 cytoplasmic expression was a significant independent predictor of a poor prognosis after adjusting for the effects of other prognostic factors (P = 0.002).

CONCLUSIONS

Mucin expression profiles in ultrasound-guided fine-needle aspiration specimens have excellent diagnostic utility and are useful predictors of outcome in patients with PDAC.

Validation of histomolecular classification utilizing histological subtype, MUC1, and CDX2 for prognostication of resected ampullary adenocarcinoma

Background:

Outcomes for ampullary adenocarcinomas are heterogeneous, and numerous methods of categorisation exist. A histomolecular phenotype based on histology, caudal-type homeodomain transcription factor 2 (CDX2) staining and Mucin 1 (MUC1) staining has recently been tested and validated in two cohorts. We attempt to validate this classification in a large patient population.

Methods:

Tissue samples from 163 patients with resected ampullary adenocarcinoma were classified based on histology and immunohistochemical expression of CDX2 and MUC1. A pancreaticobiliary histomolecular classification (PB) was defined as a sample with pancreaticobiliary histology, positive MUC1 and negative CDX2 expression.

Results:

There were 82 deaths; median follow-up of 32.4 months; and median overall survival of 87.7 (95% CI 42.9–109.5) months. PB comprised 28.2% of the cases. Factors associated with overall survival were histological subtype (P=0.0340); T1/2 vs T3/4 (P=0.001); perineural (P<0.0001) and lymphovascular (P=0.0203) invasion; and histomolecular intestinal histomolecular phenotype (INT) vs PB phenotype (106.4 vs 21.2 months, P<0.0001). Neither MUC1 nor CDX2 was statistically significant, although MUC1 positivity defined as ⩾10% staining was significant (P=0.0023). In multivariate analysis, age (HR 1.03), PB phenotype (HR 2.26) and perineural invasion (PNI; HR 2.26) were associated with poor survival.

Conclusions:

The prognostic ability of histomolecular phenotype has been validated in an independent cohort of ampullary adenocarcinoma patients.

Correlations of Human Epithelial Growth Factor Receptor 2 Overexpression with MUC2, MUC5AC, MUC6, p53, and Clinicopathological Characteristics in Gastric Cancer Patients with Curative Resection

Background. The purpose of this study was to evaluate the relationships between HER2 overexpression in the tumor and MUC2, MUC5AC, MUC6, and p53 status and clinicopathological characteristics of gastric cancer patients. Methods. This retrospective study included 282 consecutive patients with gastric cancer who underwent surgery at the Kosin University Gospel Hospital between April 2011 and December 2012. All tumor samples were examined for HER2 expression by immunohistochemistry (IHC) and MUC2, MUC5AC, MUC6, and p53 expression by staining. A retrospective review of the medical records was conducted to determine the correlation between the presence of HER2 overexpression and clinicopathological factors. Results. The HER2-positive rate was 18.1%. Although no association was found between HER2 expression and MUC5AC, the expression of MUC2, MUC6, and p53 was significantly correlated with HER2 positivity, respectively (P = 0.004, 0.037, 0.002). Multivariate analysis revealed that HER2 overexpression and nodal status were independent prognostic factors. Conclusions. HER2 overexpression in gastric carcinoma is an independent poor prognostic factor.

A comprehensive expression analysis of mucins in appendiceal carcinoma in a multicenter study: MUC3 is a novel prognostic factor

BACKGROUND

Mucins are implicated in survival in various cancers, but there have been no report addressed on survival in appendiceal carcinoma, an uncommon disease with different clinical and pathological features from those of other colon cancers. We aimed to investigate the clinical implications of expression of mucins in appendiceal carcinoma.

METHODS

Expression profiles of MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC6, MUC16 and MUC17 in cancer tissue were examined by immunohistochemistry in 108 cases of surgically resected appendiceal carcinoma.

RESULTS

The following relationships of mucins with clinicopathologic factors were identified: MUC1 with positive lymphatic invasion (p = 0.036); MUC2 with histological type (mucinous carcinoma, p<0.001), superficial invasion depth (p = 0.007), negative venous invasion (p = 0.003), and curative resection (p = 0.019); MUC3 with non-curative resection (p = 0.017); MUC5AC with histological type (mucinous carcinoma, p = 0.002), negative lymphatic invasion (p = 0.021), and negative venous invasion (p = 0.022); and MUC16 with positive lymph node metastasis (p = 0.035), positive venous invasion (p<0.05), and non-curative resection (p = 0.035). A poor prognosis was related to positive lymph node metastasis (p = 0.04), positive lymphatic invasion (p = 0.02), positive venous invasion (p<0.001), non-curative resection (p<0.001), and positive expression of MUC3 (p = 0.004). In multivariate analysis, positive venous invasion (HR: 6.93, 95% CI: 1.93-24.96, p = 0.003), non-curative resection (HR: 10.19, 95% CI: 3.05-34.07, p<0.001) and positive MUC3 expression (HR: 3.37, 95% CI: 1.13-10.03, p = 0.03) were identified as significant independent prognostic factors in patients with appendiceal carcinoma.

CONCLUSIONS

Expression of MUC3 in appendiceal carcinoma is an independent factor for poor prognosis and a useful predictor of outcome in patients with appendiceal carcinoma after surgery.