miR-205 targets angiogenesis and EMT concurrently in anaplastic thyroid carcinoma.

The current study aims to evaluate for the first time the inhibitory roles of miR-205 in the pathogenesis of anaplastic thyroid carcinoma. In addition, we investigated the mechanisms by which miR-205 regulates angiogenesis and epithelial-to-mesenchymal transition (EMT) in cancer. Two anaplastic thyroid carcinoma cell lines were transfected with the expression vector pCMV-MIR-205 Selected markers of angiogenesis and EMT including vascular endothelial growth factor A (VEGF-A) and zinc finger E-box-binding homeobox 1 (ZEB1) were investigated by Western blot. The interaction of miR-205 expression with EMT and angiogenesis were also investigated by assessment of matrix metalloproteinases 2 and 9 (MMP2 and MMP 9), SNAI1 (Snai1 family zinc finger 1), vimentin, E-cadherin and N-cadherin. The function of miR-205 was further tested with VEGF enzyme-linked immunosorbent assay (ELISA), wound healing, invasion and tube formation assays. Using an animal model, we studied the association of miR-205 with angiogenesis, proliferation and invasion. The following results were obtained. Permanent overexpression of miR-205 significantly suppressed angiogenesis and EMT by simultaneously targeting VEGF-A, ZEB1 and downstream products. Ectopic expression of miR-205 in cancer cells led to decreased migration, invasion and tube formation of endothelial cells. In addition, inhibition of tumour growth, vascularisation and invasion were noted in the mouse tumour xenografts. Our findings provide insights into simultaneous regulatory role of miR-205 in the pathogenesis of anaplastic thyroid carcinoma by suppressing both angiogenesis and EMT. This may open avenues to exploit miR-205 as an alternative cancer therapeutic strategy in the future.

Interactive role of miR-126 on VEGF-A and progression of papillary and undifferentiated thyroid carcinoma.

MicroRNA-126 (miR-126) expression has been shown to be associated with angiogenesis. The aim of the current study is to evaluate the functional roles of miR-126 in dysregulation of VEGF expression and cancer progression in thyroid carcinomas. The expression of VEGF-A and miR-126 were measured in 101 thyroid carcinomas tissues (including 51 conventional papillary thyroid carcinoma, 37 follicular variant of papillary thyroid carcinoma, and 13 undifferentiated thyroid carcinomas), 13 matched lymph nodes with metastatic thyroid carcinoma, 21 benign thyroid tissues, and 5 thyroid carcinoma cell lines (both papillary and undifferentiated carcinomas). Then, exogenous miR-126 was transfected, and the expressions of VEGF-A were determined (Western blot technique). Proliferation assay, cell cycle analysis, and apoptosis assays were used to evaluate the role of miR-126 in these events. Significant underexpression of miR-126 levels in thyroid cancer tissues and cell lines was detected using real-time polymerase chain reaction. Introducing exogenous miR-126 into the cancer cell lines resulted in a significant reduction of VEGF-A protein expression. Marked inhibition in proliferation, cell cycle arrest in G0-G1, and promotion of total apoptosis were also noted. The modulatory role of miR-126 on expression of VEGF-A and its tumor suppressive roles were demonstrated for the first time in thyroid cancer. The current experiments provided specific information on the functional consequences of VEGF manipulation via microRNA on cancer.

Modulatory role of miR-205 in angiogenesis and progression of thyroid cancer.

miR-205 plays a crucial role in angiogenesis and has been found in association with several types of cancers. The aims of this study were to investigate the clinical and functional roles of miR-205 on as the major initiator and modulator of angiogenesis in thyroid cancer. 101 thyroid carcinomas, including 51 conventional and 37 follicular variants of papillary thyroid carcinomas, and 13 undifferentiated thyroid carcinomas in addition to 13 lymph nodes with metastatic thyroid carcinoma were recruited to be compared with 14 nodular goitre and seven normal thyroid tissues. Five thyroid carcinoma cell lines, of papillary and undifferentiated origin with and without history of metastasis, were also used. Expression of vascular endothelial growth factor A (VEGFA) and miR-205 were measured and exogenous miR-205 were transfected to observe the changes of VEGFA (by immunofluorescence and western blot techniques). Proliferation assay, cell cycle analysis and apoptosis assays were also used to evaluate the role of miR-205 in these events. Significant under-expression of miR-205 and over-expression of VEGFA mRNA and protein were noticed in thyroid cancer tissues and cell lines compared to normal thyroid control. Transfection of miR-205 into the cancer cell lines caused significant reduction of VEGFA protein and significant inhibition in cell proliferation, arrest in G0-G1 of the cell cycle and promotion of total apoptosis (P<0.05). The angiogenic and tumour-suppressive roles of miRNA-205 were demonstrated for the first time in thyroid cancer. The current experiments provided specific information on the functional consequences of VEGF manipulation via miRNA on cancer.

The important roles of miR-205 in normal physiology, cancers and as a potential therapeutic target.

Evidences have demonstrated key mediatory roles of microRNA-205 (miR-205) in normal physiology and its aberrant expression in many cancers. Indeed, miR-205 has been identified as both a tumour suppressive and oncogenic miRNA playing crucial roles in tumourigenesis through regulating different cellular pathways such as cell survival, apoptosis, angiogenesis and metastasis. As a tumour suppressor, miR-205 acts as an inhibitor of cell proliferation, migration and invasion. On the other hand, as an oncogene, miR-205 promotes tumour initiation and development. All these functions act through different target genes in various types of cancers. Also, miR-205 displays potential as a therapeutic target for different cancers. To conclude, miR-205 has important clinical and pathological correlations in different cancers and may act as a diagnostic and prognostic marker as well as new molecular target for cancer therapy.

The expression profiles of the galectin gene family in primary and metastatic papillary thyroid carcinoma with particular emphasis on galectin-1 and galectin-3 expression.

INTRODUCTION: Galectin family members have been demonstrated to be abnormally expressed in cancer at the protein and mRNA level. This study investigated the levels of galectin proteins and mRNA expression in a large cohort of patients with papillary thyroid carcinoma and matched lymph node metastases with particular emphasis on galectin-1 and galectin-3. METHODS: mRNA expression of galectin family members (1, 2, 3, 4, 7, 8, 9, 10 and 12) were analysed by real-time polymerase chain reaction in 65 papillary thyroid carcinomas, 30 matched lymph nodes with metastatic papillary thyroid carcinoma and 5 non-cancer thyroid tissues. Galectin-1 and 3 protein expression was determined by immunohistochemistry in these samples. RESULTS: Significant expression differences in all tested galectin family members (1, 2, 3, 4, 7, 8, 9, 10 and 12) were noted for mRNA in papillary thyroid carcinomas, with and without lymph node metastasis. Galectin-1 protein was more strongly expressed than galectin-3 protein in papillary thyroid carcinoma. Galectin-1 protein was found to be overexpressed in 32% of primary papillary thyroid carcinomas. A majority of lymph nodes with metastatic papillary thyroid carcinoma (53%) had significantly increased expression of galectin-1 protein, as did 47% of primaries with metastases. Galectin-1 mRNA levels were decreased in the vast majority (94%) of primary thyroid carcinomas that did not have metastases present. Galectin-3 protein levels were noted to be overexpressed in 15% of primary papillary thyroid carcinomas. In primary papillary thyroid carcinoma with lymph node metastases, 32% had over expression of galectin-3 protein. Overexpression of galectin-3 mRNA was noted in 58% of papillary thyroid carcinomas and 64% of lymph nodes bearing metastatic papillary thyroid carcinoma. Also, primary papillary thyroid carcinoma with lymph node metastases had significantly higher expression of galectin-3 mRNA compared to those without lymph node metastases. CONCLUSION: Galectin family members show altered expression at the mRNA level in papillary thyroid cancers. Overexpression of galectin-1 and 3 proteins were noted in papillary thyroid carcinoma with lymph node metastases. The results presented here demonstrated that galectin-1 and galectin-3 expression have important roles in clinical progression of papillary thyroid carcinoma.