P-19: Evaluating Expression Pattern of eIF4E as Molecular Biomarker in Thyroid Tumors


Ghanbarian M *, Hoseinpourfeizi M , Khalaj-Kondori M , Shiri S ,

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Objective: Regulation of protein synthesis in early stage of translation depends on the cooperative function of eIF4F complex especially eukaryotic initiation factor 4E (eIF4E) affecting crucial cellular process such as cell cycle progression, cell growth, development and apoptosis by selective upregulating the translation of malignancy-related mRNAs (VEGF, ODC, cyclin D1) through promoting mRNA nucleocytoplasmic transport and/or facilitating ribosome loading during translation initiation. Large body of experimental data implicates eIF4E is in correlation cellular transformation, tumorigenesis and metastatic progression. Considering overexpression level of eIF4E in multiple cancer types, including malignancies of the prostate, breast, stomach, colon, lung, skin, bladder, cervix and the hematopoietic system associated with increasing grade of disease, it has been regarded as a valuable tumor marker for diagnosis and prognosis of thyroid cancer. Evaluating this theory, we have investigated the expression pattern of eIF4E in malignant versus non-malignant thyroid tissues and its association with the clinicopathologic properties of thyroid cancer. Materials and Methods: We used semi-quantitative RT-PCR analysis to examine the expression of eIF4E in 28 papillary carcinoma tissues containing 17 malignant samples and 11 benign samples, 9 nodular goiter and 14 corresponding normal thyroid tissue, adjacent to the malignant lesions. Seven of the 17 papillary carcinomas were considered to be clinically in advanced stage of tumor progression due to their extension and histology. DNA sequencing was used to confirm the identity of amplified fragments. The significancy of the data was analyzed using ANOVA and t test. Results: Our data revealed significant overexpression of eIF4E in tumor samples compared to non-tumor lesions and normal tissues (P<0.05), moreover it’s expression level was notably increased in malignant tumor samples compare to benign tumor samples (p<0.05) and the highest expression observed in advanced stage of malignant tumors. It is noteworthy that expression rate of eIF4E between benign tumors and nodular goiter samples were not significant (p>0.05), however expression level of eIF4E in mentioned groups toward margins were remarkably significant (p<0.05). Conclusion: According to the results of data analysis, differential expression pattern of eIF4E in thyroid tissues is implying its role in neoplastic transformation, tumorgenesis, tumor progression and malignancy, which potentially could have a practical usefulness in diagnosis and/or therapy of thyroid tumors