The methods of LipofectAMINE PLUS mediated transient transfection were similar;

The expression and activity of Aurora kinases are precisely regulated during the cell cycle, since their levels are low in G1/S phase and enhanced in the G2/M phase to be decreased after mitosis. This reduction has been shown to [You must be registered and logged in to see this link.] involve the ubiquitin pro teasome pathway. Alterations in Aurora kinases expression are linked to tumor progression. The genes encoding the Aurora kinases map, in fact, into chromosomal regions that are frequently amplified in different cancer types, and overexpression of each kinase has been detected in tumor cell lines. Moreover, it has been demon strated that the upregulation of Aurora A or B causes defects in chromosome segregation and consequent aneuploidy, and induces cell malignant transformation.

In addition, tumor tissue expression of Aurora A or Aurora B has been shown to be a significant prog nostic factor in several human malignancies, including the non small cell lung, breast, liver, colorectal, ovarian, and head and neck squamous [You must be registered and logged in to see this link.] cell carcinomas. These evidences suggest an important role for Aurora kinases in cancer progression, and structure based drug design has led to the identification of new putative drugs which efficiently inhibit Aurora kinases. This may be of relevance in those cancers which do not respond well to the available antimitotic agents, includ ing a subset of medullary thyroid cancers. The latter arise from the calcitonin producing parafollicular C cells of the thyroid and accounts for about 5 8% of all thyroid cancers. It develops mostly as a sporadic tumor, being hereditary in 20 30% of cases which include the familial MTC and the multiple endocrine neoplasia type 2.

All the hereditary MTC and approximately 50% of the sporadic tumors are caused by dominant autoso mal activating [You must be registered and logged in to see this link.] mutations of the RET proto oncogene. Over the last decades, surgery has remained the only curative therapy, and the overall survival rate of unselected patients ten years after the primary surgery is about 70%, while treatments of recurrent or persistent disease with conventional radiotherapy or chemotherapy are generally of limited value and with no benefit in terms of survival. This implies that patients classification, initial surgical treatment and lack of ade quate post surgical therapy are still major problems in the management of these patients.

In the present study, we investigated the expression of the three Aurora kinases in 26 human MTC and ana lyzed the effects of the Aurora inhibitor MK 0457 on growth and tumorigenicity of the MTC derived cell line TT. Methods Cell line and Materials Thyroid medullary carcinoma derived cell line TT was purchased from Interlab Cell Line Collection. Mouse monoclonal and rabbit polyclonal antibodies against b tubulin and b actin were from Sigma Aldrich Co. Rabbit polyclonal anti Aurora C anti body was generated against a 16 amino acid peptide of the C terminal part of Aurora C by Eurogentec. Mouse monoclonal antibodies against Aurora A and Aurora B were from Abcam. The mouse monoclonal anti body anti phospho histone H3 was from Millipore. The secondary anti rabbit and anti mouse antibodies TRITC and FITC conjugated were from Jack son Laboratories.