GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

OBJECTIVE: To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry. INTRODUCTION: Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data. METHODS: Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types. RESULTS: Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Fortyseven per cent of prostate adenocarcinomas were positive, as were 29 percent of thyroid, 10 percent of gastric and 5 percent of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42 percent of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6 percent and 9.4 percent of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression. CONCLUSION: Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined.

E-cadherin/beta-catenin expression pattern, clinicopathological parameters and prognosis in gastric carcinomas

Objectives: This study aimed to evaluate the expression pattern of some markers (E-cadherin and â-catenin) related to cellular adhesion and their relationship with histological tumor type according to Laurén’s system, clinicopathological features and patient survival. Material and Methods: We did immunohistochemical analysis in a retrospective series of 446 gastric carcinomas using tissue microarray method (TMA). Clinicopathological features and overall survival data of all patients were retrospectively reviewed from hospital records. For all statistical analyses, p<0.05 was considered significant. Results: The reduced/absent expression of E-cadherin occurred more frequently in diffuse than intestinal type tumors and it was correlated with worse biological behavior and poor prognosis for patients with diffuse type gastric carcinomas. The pattern of â-catenin expression was closely related to histological type and E-cadherin expression. Although patients with nuclear/absent â-catenin immunoreactivity showed worse survival index, no statistical correlation was found with overall survival. In multivariated analysis, only pTNM staging system persisted as independent prognostic marker. Conclusion: In the present study, alterations in E-cadherin/â-catenin complex expression showed significant correlations with clinicopathological parameters, as well as its implications for tumor progression and prognosis in gastric cancer. Our results indicate that markers expression pattern may be a useful marker of differentiation and suggest further investigations of their prognostic relevance to specific histological groups.