Correlations of MUC15 overexpression with clinicopathological features and prognosis of glioma

MUC16 mutation is associated with tumor grade, clinical features, and prognosis in glioma patients

MUC16 is a member of the attached mucin family that encodes cancer antigen 125 (CA-125), but the association of MUC16 status with grade and subtypes of glioma patients has not yet been established. Data for MUC16 mRNA expression in 37 different cancer types were considered, and genomic data from the Cancer Genome Atlas (TCGA) from 1051 low-grade glioma (LGG) patients and 833 glioblastoma (GBM) patients were analyzed. LGG and GBM has low expression of MUC16, but it is frequently mutated in GBM. Kaplan-Meier survival analysis, glioma subtypes, methylation, and isocitrate dehydrogenase (IDH1) status were all performed. We found that mutated-MUC16 in LGG patients is associated with better prognosis considering overall survival (OS), IDH1, methylation, 1p/19q, and 10q status. Conversely, MUC16 mutation were related with worse prognosis in GBM patients upon analyzing those same parameters. Therefore, MUC16 mutations may assist in glioma diagnosis and prognosis and should be further studied in this tumor type.

The diagnostic and prognostic potential of the EGFR/MUC4/MMP9 axis in glioma patients

Glioblastoma is the most aggressive form of brain cancer, presenting poor prognosis despite current advances in treatment. There is therefore an urgent need for novel biomarkers and therapeutic targets. Interactions between mucin 4 (MUC4) and the epidermal growth factor receptor (EGFR) are involved in carcinogenesis, and may lead to matrix metalloproteinase-9 (MMP9) overexpression, exacerbating cancer cell invasiveness. In this study, the role of MUC4, MMP9, and EGFR in the progression and clinical outcome of glioma patients was investigated. Immunohistochemistry (IHC) and immunofluorescence (IF) in fixed tissue samples of glioma patients were used to evaluate the expression and localization of EGFR, MMP9, and MUC4. Kaplan-Meier survival analysis was also performed to test the prognostic utility of the proteins for glioma patients. The protein levels were assessed with enzyme-linked immunosorbent assay (ELISA) in serum of glioma patients, to further investigate their potential as non-invasive serum biomarkers. We demonstrated that MUC4 and MMP9 are both significantly upregulated during glioma progression. Moreover, MUC4 is co-expressed with MMP9 and EGFR in the proliferative microvasculature of glioblastoma, suggesting a potential role for MUC4 in microvascular proliferation and angiogenesis. The combined high expression of MUC4/MMP9, and MUC4/MMP9/EGFR was associated with poor overall survival (OS). Finally, MMP9 mean protein level was significantly higher in the serum of glioblastoma compared with grade III glioma patients, whereas MUC4 mean protein level was minimally elevated in higher glioma grades (III and IV) compared with control. Our results suggest that MUC4, along with MMP9, might account for glioblastoma progression, representing potential therapeutic targets, and suggesting the 'MUC4/MMP9/EGFR axis' may play a vital role in glioblastoma diagnostics.

High Expression of MUC15 Is Correlated with Poor Prognosis of Pancreatic Cancer and Promotes Migration, Invasion, and Chemo-Resistance In Vitro

BACKGROUND MUC15, one of the hydrophilic glycoproteins that protect wet-surfaced epithelia, has been shown to be involved in tumorigenesis of various tumors. However, the mechanism of MUC15 in pancreatic cancer have not been revealed yet. Our study focused on investigating its clinical significance and function in pancreatic cancer. MATERIAL AND METHODS Using tissue microarrays and immunohistochemical staining, we evaluated MUC15 expression in 92 patients diagnosed with pancreatic ductal adenocarcinoma (PDAC). The correlations between MUC15 expression and clinicopathological variables and prognosis were analyzed. To validate our findings, we analyzed the data from an online database. We then demonstrated its function or mechanism in pancreatic cancer cell lines using transwell assay, cytotoxicity assay, cell apoptotic detection, and western blot. RESULTS The expression level of MUC15 was remarkably increased in PDAC tissues in comparison with para-cancerous tissues, and was associated with poor prognosis. Cytoplasmic MUC15 expression was identified as an independent prognostic indicator for overall survival by multivariate Cox regression analysis. Functionally, overexpressed MUC15 enhanced the migration and invasion ability in cancer cells. In vitro studies revealed that MUC15 enhanced the gemcitabine resistance of pancreatic cancer. Additionally, the regulatory mechanism of MUC15 in PDAC were correlated with ERK and AKT signaling pathways. CONCLUSIONS We performed integrated analysis and revealed that MUC15 is a good prognostic predictor for patients with PDAC. The functional experiments showed that MUC15 contributed to the malignant behaviors of pancreatic cancer in vitro.

Targeting MUC15 Protein in Cancer: Molecular Mechanisms and Therapeutic Perspectives

MUC15, a member of the mucin family, is a heavily glycosylated transmembrane protein with the primary functions of lubricating surfaces, establishing a selective molecular barrier at the epithelium and mediating signal transduction. Aberrant expression of MUC15 plays a crucial role in the progression of multiple diseases, including malignant tumors. MUC15 has been identified as a tumor suppressor, but current evidence indicate its function as an oncogene in different types of cancers. MUC15 has been shown to be involved in the development of cancer and influence cellular growth, adhesion, invasion, metastasis and immune immunomodulation. However, the precise role of MUC15 in tumour development has not been thoroughly clarified. Here, we systematically summarize the structure and function of MUC15 in cancer, and discuss its potential role in cancer treatment.

MUC15 promotes growth and invasion of glioma cells by activating Raf/MEK/ERK pathway

MUC15 is a novel mucin associated with the cell membrane that is overexpressed in human gliomas. Its function in glioma is unclear. In this study, high MUC15 levels were detected in glioma tissues and cells. We found that transfection with MUC15 siRNA in U251 and T98G cells reduced MUC15 expression and decreased cell proliferation, invasion, and migration (P < .05). After transfecting U251 and T98G cells with pcDNA3.1-myc-His-MUC15 plasmid to overexpress MUC15, MUC15 expression was significantly upregulated and cell proliferation, invasion, and migration were increased (P < .05). MUC15 activated the Raf/MEK/ERK signalling pathway and the ERK inhibitor PD98059 partly reversed MUC15-enhanced proliferation, invasion, and migration of glioma cells (P < .05). The results indicate that MUC15 plays a part in glioma tumorigenesis, and the Raf/MEK/ERK signalling is involved in the regulation of MUC15 on glioma cell activity.

Deregulation of cell adhesion molecules is associated with progression and poor outcomes in endometrial cancer: Analysis of The Cancer Genome Atlas data

Cell adhesion molecules (CAMs) determine the behavior of cancer cells during metastasis. Although some CAMs are dysregulated in certain types of cancer and are associated with cancer progression, to the best of our knowledge, a comprehensive study of CAMs has not been undertaken, particularly in endometrial cancer (EC). In the present study the expression of 225 CAMs in EC patients with various clinicopathological phenotypes were evaluated by statistical analysis using publicly available data from The Cancer Genome Atlas database. The Kaplan-Meier method, and univariate and multivariate Cox proportional hazards regression models were used for survival analyses. Among the differentially expressed CAMs that were associated with aggressive clinicopathological phenotypes, 10 CAM genes were independent prognostic factors compared with other clinicopathological prognostic factors, including stage, grade, age, lymph node status, peritoneal cytology and histological subtype. A total of six genes (L1 cell adhesion molecule, mucin 15, cell surface associated, cell adhesion associated, oncogene regulated, immunoglobulin superfamily member 9B, protocadherin 9 and protocadherin β1) were selected for integrative analysis. The six-gene signature was demonstrated to be an independent prognostic factor and could effectively stratify patients with different risks. Patients with more high-expression CAMs had a higher risk of poor overall survival (OS) rate. The mortality risk for patients with elevation of >4 CAMs was 11 times of that in those without elevation of these 6 CAMs. Similar results were obtained when relapse-free survival (RFS) time was used during the analysis. Prognostic reliability of the six-gene model was validated using data of an independent cohort from the International Cancer Genome Consortium. In conclusion, a combination of CAM alterations contributed to progression and aggressiveness of EC. The six-gene signature was effective for predicting worse OS and RFS in patients with EC and could be complementary to the present clinical prognostic criteria.

Upregulation of cell-surface mucin MUC15 in human nasal epithelial cells upon influenza A virus infection

Background

Cell-surface mucins are expressed in apical epithelial cells of the respiratory tract, and contribute a crucial part of the innate immune system. Despite anti-inflammatory or antiviral functions being revealed for certain cell-surface mucins such as MUC1, the roles of other mucins are still poorly understood, especially in viral infections.

Methods

To further identify mucins significant in influenza infection, we screened the expression of mucins in human nasal epithelial cells infected by H3N2 influenza A virus.

Results

We found that the expression of MUC15 was significantly upregulated upon infection, and specific only to active infection. While MUC15 did not interact with virus particles or reduce viral replication directly, positive correlations were observed between MUC15 and inflammatory factors in response to viral infection. Given that the upregulation of MUC15 was only triggered late into infection when immune factors (including cytokines, chemokines, EGFR and phosphorylated ERK) started to peak and plateau, MUC15 may potentially serve an immunomodulatory function later during influenza viral infection.

Conclusions

Our study revealed that MUC15 was one of the few cell-surface mucins induced during influenza infection. While MUC15 did not interact directly with influenza virus, we showed that its increase coincides with the peak of immune activation and thus MUC15 may serve an immunomodulatory role during influenza infection.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4213-y) contains supplementary material, which is available to authorized users.

Genomic alterations in mucins across cancers

The significance of mucins in cancers has led to the development of novel biomarkers and therapeutic agents against cancers. Despite significant advances in the understanding of mucins, systemic investigations into the role of mucins in cancer biology focusing particularly on the histological subtypes and stages, along with other variables, are yet to be carried out to discover potential novel functions and cancer-specific roles. Here, we investigated 11 mucin expressing cancers for DNA mutations, mRNA expression, copy number, methylation, and the impacts these genomic features may have on patient survival by utilizing The Cancer Genome Atlas dataset. We demonstrate that mucin DNA mutations have a significant rate, pattern, and impact on cancer patient survival depending on the tissue of origin. This includes a frequent T112P mutation in MUC1 that is seen in half of the pancreatic MUC1 mutations, as well as being present in other cancers. We also observed a very frequent MUC4 mutation at H4205, which correlated with survival outcomes in patients. Furthermore, we observed significant alterations in mucin mRNA expression in multiple tumor types. Our results demonstrate de novo expression of certain mucins in cancer tissues, including MUC21 in colorectal cancers. We observed a general decrease in promoter methylation for mucins, which correlated with decreased expression of many genes, such as MUC15 in kidney cancers. Lastly, several mucin gene loci demonstrated copy number increase in multiple histological subtypes. Thus, our study presents a comprehensive analysis of genomic alterations in mucins and their corresponding roles in cancer progression.

MiR-215, an activator of the CTNNBIP1/β-catenin pathway, is a marker of poor prognosis in human glioma

MicroRNA-215 (miR-215) promotes tumor growth in various human malignancies. However, its role has not yet been determined in human glioma. Here, we found that levels of miR-215 were higher in glioma tissues than in corresponding non-neoplastic brain tissue. High miR-215 expression was correlated with higher World Health Organization (WHO) grades and shorter overall survival. Multivariate and univariate analysis indicated that miR-215 expression was an independent prognostic factor. We also found that TGF-beta1, phosphorylated beta-catenin, alpha-SMA, and fibronectin were increased in glioma tissues. Additionally, CTNNBIP1, a direct target of miR-215, was decreased in glioma compared to adjacent normal tissue. These data indicate that miR-215 activates Wnt/β-catenin signaling by increasing β-catenin phosphorylation, α-SMA expression, and fibronectin expression. It promotes TGF-β1-induced oncogenesis by suppressing CTNNBIP1 in glioma. In summary, miR-215 is overexpressed in human glioma, is involved in TGF-β1-induced oncogenesis, and can be used as a marker of poor prognosis in glioma patients.

BRCA1/2 mutations perturb telomere biology: characterization of structural and functional abnormalities in vitro and in vivo

BRCA1 mutation is associated with carcinogenesis, especially of breast tissue. Telomere maintenance is crucial for malignant transformation. Being a part of the DNA repair machinery, BRCA1 may be implicated in telomere biology. We explored the role of BRCA1 in telomere maintenance in lymphocytes of BRCA1/2 mutation carriers and in in vitro system by knocking down its expression in non-malignant breast epithelial cells.The results in both systems were similar. BRCA1/2 mutation caused perturbation of telomere homeostasis, shortening of the single stranded telomere overhang and increased the intercellular telomere length variability as well as the number of telomere free chromosomal ends and telomeric circles. These changes resulted in an increased DNA damage status. Telomerase activity, inducibility and expression remained unchanged. BRCA1 mutation resulted also in changes in the binding of shelterin proteins to telomeres. DNMT-1 levels were markedly reduced both in the carriers and in in vitro system. The methylation pattern of the sub-telomeric regions in carriers suggested hypomethylation in chromosome 10. The expression of a distinct set of genes was also changed, some of which may relate to pre-disposition to malignancy.These results show that BRCA gene products have a role in telomere length homeostasis. It is plausible that these perturbations contribute to malignant transformation in BRCA mutants.