Diffuse expression of MUC1 in metastases of renal clear cell carcinoma as a possible therapeutic target for renal cancer

A MUCINs expression signature impacts overall survival in patients with clear cell renal cell carcinoma

Background

Kidney cancer, especially clear cell renal cell carcinoma (ccRCC), is one of the most common cancers in the urinary system. Previous studies suggested that certain members of MUCINs could serve as independent predictors for the survival of ccRCC patients. None of them, however, is robust enough to predict prognosis accurately.

Objective

To analyze the correlation of MUCINs alterations and their expression levels with the prognosis of ccRCC patients and develop a prognosis‐related predictor.

Methods

We applied whole‐exome sequencing in samples from 22 Chinese ccRCC patients to identify genetic alterations in MUCIN genes and analyzed their genetic alterations, expression, and correlation with survival using the TCGA, GSE73731, and GSE29069 datasets.

Result

Genetic alternations in MUCINs were identified in 91% and 51% of ccRCC patients in our cohort and the TCGA database, respectively. No correlation with survival was found for the genetic alterations. Using unsupervised clustering analysis of gene expression, we identified two major clusters of MUCIN expression patterns. Cluster 1 was characterized by a global overexpression of MUC1, MUC12, MUC13, MUC16, and OVGP1; and cluster 2 was characterized by a global overexpression of MUC4, MUC5B, MUC6, MUC20, EMCN, and MCAM. Patients with cluster 1 expression pattern had significantly shorter overall survival time and worse clinical features, including higher tumor grades and metastasis. Meanwhile, they had a higher level of mutation counts and more infiltrated immune cells, but lower enrichment in angiogenesis signature genes. A five‐MUCINs expression signature was constructed from cluster 1, and notably, it was demonstrated to be associated with shorter overall survival. A similar worse clinical feature, lower angiogenesis but the more immune signature, was identified in samples presented with signature 1. In the validation data set GSE29069, patients with signature 1 were also associated with a trend of poor survival outcomes.

Conclusion

We established a five‐MUCINs expression signature as a new prognostic marker for ccRCC. The distinct tumor microenvironment feature between the two signatures may further affect ccRCC patients’ clinical management.

Differential expression and clinical relevance of MUC1 in renal cell carcinoma metastasis

PURPOSE

To determine the differential expression patterns and prognostic relevance of Mucin-1 (MUC1) expression in clear cell renal cell carcinoma (RCC) metastasis.

METHODS

Tissue microarrays (TMA) from samples of 151 RCC metastases, 61 primary RCCs and corresponding benign renal tissues were immunohistochemically stained for MUC1 and semi-quantitatively evaluated by immunoreactivity scores (IRS). MUC1 differential expression in metastasis, primary RCC and normal tissue were comparatively analyzed. Patient characteristics and clinical follow-up for patients with metastatic RCC (mRCC) were recorded. Correlations of MUC1 expression with mRCC survival were determined.

RESULTS

Median cytoplasmic expression was highest in benign tissue (IRS = 1.04). Primary RCC (0.50) and metastasis (0.12) showed significantly lower cytoplasmic staining intensity. Membranous expression in benign tissue was, however, significantly lower (0.21) compared with primary RCC (0.59) and metastasis (0.57). Notable differences of MUC1 cytoplasmic and membranous expression were observed between different metastasis sites. Significantly higher (P = 0.014) membranous expression was observed in pulmonary versus non-pulmonary lesions, while no significant differences of cytoplasmic MUC1 expression were observed. The prognostic relevance of MUC1 expression in metastatic RCC was limited.

CONCLUSIONS

MUC1 is differentially expressed in benign renal tissue, primary RCC and RCC metastasis. Membranous MUC1 expression was significantly elevated in pulmonary metastases compared to non-pulmonary lesions, which may reflect individual biology and putative response to MUC1-based anti-cancer therapy.

Secondary tumors of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration: a 10-year experience

Determining whether a pancreatic mass is a primary or secondary neoplasm is necessary for appropriate treatment. We reviewed our experience using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for diagnosis of pancreatic tumors to identify clinical and cytopathologic characteristics of metastatic disease. We reviewed all cases of tumors metastatic to the pancreas evaluated at The University of Texas MD Anderson Cancer Center and The Methodist Hospital in Houston, Texas during the period from 2002 to 2012. The review included cytologic specimens, clinical history, radiologic findings, primary tumor type, and clinical follow-up. We identified 66 patients with disease metastatic to the pancreas for which cytologic material was available: 38 (58%) men and 28 (42%) women, with an average age of 63 years (range, 40-89 years). Most metastases (98%) were single lesions, and nearly half were located in the head of the pancreas (30/66). The most common site of origin for these metastases was kidney (27 [41%] cases). Follow-up information was available for 65 (98%) patients, and duration of follow-up ranged from <1 to 10 years (mean, 2.3 years). Thirty-three patients (50%) were alive at the time of the most recent follow-up contact. Of the 25 patients with metastatic renal cell carcinoma, clear cell type, 19 (76%) were alive at the time of the most recent follow-up. It was concluded that metastases may mimic primary pancreatic carcinomas both clinically and cytologically. Ancillary studies in conjunction with clinical history are necessary for the accurate diagnosis of FNAs of secondary pancreatic tumors.

Immunolocalisation of E-cadherin and beta-catenin in human pterygium

AIM

The pterygium represents an invasion of a wing of altered ocular surface tissue into the normal cornea. The head itself is slightly elevated and white, which is the only site of firm adhesion to the globe. The mechanisms of cell proliferation and adhesion in pterygium epithelium, however, are unknown. The aim of this study was to analyse the expression of cell adhesion molecules in pterygium tissues.

METHODS

Six pterygia were surgically removed using the bare-sclera procedure, and two normal corneas and a normal bulbar conjunctiva were also obtained. Formalin-fixed, paraffin-embedded tissues were analysed by immunohistochemistry with anti-E-cadherin and beta-catenin antibodies.

RESULTS

Immunoreactivity for E-cadherin was not detected in the normal cornea and conjunctiva. In contrast, all corneal and conjunctival epithelial cells showed a weak homogeneous immunoreaction for beta-catenin on the cell membrane. In the pterygium head, the thickness was relatively marked compared with the body, and normal conjunctival and corneal epithelia. E-cadherin as well as beta-catenin was heterogeneously expressed in the cell membrane and cytoplasm of a variety of epithelial cells, whereas the expression was less marked in the body. Several epithelial cells showed intense nuclear immunoreactivity for beta-catenin. Immunoreactivity of beta-catenin, but not E-cadherin, was detected in only a few stromal cells, which were less marked than in epithelial cells.

CONCLUSION

It is suggested that E-cadherin and beta-catenin are concentrated in pterygium tissue, and are possibly involved with epithelial proliferation and adhesion.