Targeting MUC4 in pancreatic cancer: miRNAs

EGF-Containing Membrane-Bound Mucins: A Hidden ErbB2 Targeting Pathway?

Membrane-bound mucins belong to a heterogeneous family of large O-glycoproteins involved in numerous cancers and inflammatory diseases of the epithelium. Some of them are also involved in protein-protein interactions, with receptor tyrosine kinase ErbB2, and fundamental and clinical data showed that these complexes have a detrimental impact on cancer outcome, thus raising interest in therapeutic targeting. This paper aims to demonstrate that MUC3, MUC4, MUC12, MUC13, and MUC17 have a common evolutionary origin and share a common structural organization with EGF-like and SEA domains. Theoretical structure-function relationship analysis of the conserved domains indicated that the studied membrane-bound mucins share common biological properties along with potential specific functions. Finally, the potential druggability of these complexes is discussed, revealing ErbB2-related pathways of cell signaling to be targeted.

Mutational burden of resectable pancreatic cancer, as determined by whole transcriptome and whole exome sequencing, predicts a poor prognosis

Despite the genomic characterization of pancreatic cancer (PC), marked advances in the development of prognosis classification and novel therapeutic strategies have yet to come. The present study aimed to better understand the genomic alterations associated with the invasive phenotype of PC, in order to improve patient selection for treatment options. A total of 30 PC samples were analysed by either whole transcriptome (9 samples) or exome sequencing (21 samples) on an Illumina platform (75X2 or 100X2 bp), and the results were matched with normal DNA to identify somatic events. Single nucleotide variants and insertions and deletions were annotated using public databases, and the pathogenicity of the identified variants was defined according to prior knowledge and mutation-prediction tools. A total of 43 recurrently altered genes were identified, which were involved in numerous pathways, including chromatin remodelling and DNA damage repair. In addition, an analysis limited to a subgroup of early stage patients (50% of samples) demonstrated that poor prognosis was significantly associated with a higher number of known PC mutations (P=0.047). Samples from patients with a better overall survival (>25 months) harboured an average of 24 events, whereas samples from patients with an overall survival of <25 months presented an average of 40 mutations. These findings indicated that a complex genetic profile in the early stage of disease may be associated with increased aggressiveness, thus suggesting an urgent requirement for an innovative approach to classify this disease.

Lower Serum Levels of miR-29c-3p and miR-19b-3p as Biomarkers for Alzheimer's Disease

MicroRNAs (miRNAs) are short noncoding RNA that participate in posttranscriptional gene regulation. However, little is understood about the roles of miRNAs in Alzheimer's disease (AD). In this study, we used next-generation sequencing on RNA extracted from the serum samples of 20 AD patients and 20 controls, yielding a total of 72 miRNAs with significantly changed expression levels. Among these candidates, we selected 9 miRNAs with most significant alteration in disease, and validated their expression levels using RT-qPCR analysis on serum samples from 45 AD patients and 40 control subjects. Thus, the serum levels of miR-146a-5p, 106b-3p, 195-5p, 20b-5p, and 497-5p were significantly higher, while those of miR-125b-3p, 29c-3p, 93-5p and 19b-3p were significantly lower in AD patients, compared with control subjects. Two miRNAs, miR-29c-3p and miR-19b-3p, were selected because both RNA deep-sequencing and q-PCR methods indicated lower serum levels of these miRNAs in AD patients. Computational analysis predicted that 3'-untranslated region of signal transduction and activator of transcription 3 (STAT3) mRNA is targeted both by miR-29c-3p and miR-19b-3p. Using SH-SY5Y human neuroblastoma cells, we showed that transfection with miR-29c-3p or miR-19b-3p inhibitor significantly increased STAT3 phosphorylation. Furthermore, Water maze test, which assesses the learning and memory deficits in rodents, showed that escape latency was significantly shorter in AD rats with overexpression of miR-29c-3p or miR-19b-3p than in control AD rats. These results suggest that miR-29c-3p or miR-19b-3p may contribute to the cognitive function. In conclusion, the serum levels of miR-29c-3p and miR-19b-3p are helpful biomarkers for AD.

Mucins: Structural diversity, biosynthesis, its role in pathogenesis and as possible therapeutic targets

Mucins are the main structural components of mucus that create a selective protective barrier for epithelial surface and also execute wide range of other physiological functions. Mucins can be classified into two types, namely secreted mucins and membrane bounded mucins. Alterations in mucin expression or glycosylation and mislocalization have been seen in various types of pathological conditions such as cancers, inflammatory bowel disease and ocular disease, which highlight the importance of mucin in maintaining homeostasis. Hence mucins can be used as attractive target for therapeutic intervention. In this review, we discuss in detail about the structural diversity of mucins; their biosynthesis; its role in pathogenesis; regulation and as possible therapeutic targets.

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.

Mucins in pancreatic cancer: biological role, implications in carcinogenesis and applications in diagnosis and therapy

Pancreatic cancer is the fourth highest cause of cancer mortality in the world. It has very low survival rates owing to late diagnosis resulting from the absence of accurate diagnostic tools and effective therapies. Hence, there is a pressing need to develop new diagnostic and therapeutic tools. In the recent years, there has been new evidence implicating the importance of mucins in pancreatic carcinogenesis. Mucins belong to a group of heavily glycosylated proteins, and are often aberrantly expressed in a number of cancers such as pancreatic cancer. Therefore, this literature review will summarise the role of mucins and mucin expression in pancreatic neoplasms. Subsequently the paper will also discuss the most recent advances in the biological properties of mucins and their role in carcinogenesis and resistance to chemotherapy. Then it will conclude on the newest developments in diagnosis and therapy based on mucins for pancreatic cancer.

Prognostic role of microRNA-203 in various carcinomas: evidence from a meta-analysis involving 13 studies

Growing evidence from recent studies has revealed that microRNA-203 (miR-203) might be an attractive prognostic biomarker for cancer. But controversy still remains. The aim of this meta-analysis was to summarize available evidences and clarify the preliminary predictive value of miR-203 for prognosis in cancer patients. Eligible studies were identified through multiple research strategies in PubMed, EMBASE and Web of Science up to October 2015. Key statistics such as pooled hazard ratios (HR) with 95 % confidence intervals (CIs) were utilized to calculate patient survival. 13 eligible studies with 1600 patients were ultimately enrolled in this meta-analysis. Our results failed to show a significant relation between upregulated miR-203 expression and a favorable overall survival (OS) (HR 1.00, 95 % CI 0.65-1.36) in a random effect model. However, in subgroup analysis, we found that high expression of miR-203 was significantly associated with poor OS in Caucasian patients (HR 1.31, 95 % CI 1.06-1.55). In contrast, for Asian patients, over-expression of miR-203 was an independent prognostic factor for better and OS (HR 0.59, 95 % CI 0.22-0.96). It also suggested that cancer types and miRNA assay method were significant associated with prognosis. The over-expression of miR-203 was effectively predictive of worse prognosis in breast cancer (HR 6.35, 95 % CI 1.34-11.36), pancreatic cancer (HR 1.19, 95 % CI 1.08-1.30), ependymoma (HR 1.35, 95 % CI 1.10-1.61), but for glioma patients, elevated miR-203 is a potential biomarker for predicting better progression of cancer (HR 0.26, 95 % CI -0.02 to 0.54). Besides, for direct miRNA profiling studies, over-expression of miR-203 was an independent prognostic factor for worse OS (HR 6.35, 95 % CI 1.34-11.36). This meta-analysis indicated that ethnicity, tumor type and miRNA assay method mainly contributed to heterogeneity. Considering the insufficient evidence, further relevant studies are warranted.