USE OF ANTIHER-2 APTAMER FOR SPECIFIC DELIVERY OF MIR-205 IN BREAST CANCER

COIRINI, H.; MARQUEZ LARA, J.P.; VARGAS, M.; BRUNO, M.A.; MESTRE GIMENEZ, M.B.

CABA

Congreso; Reunion Conjunta de Sociedades de Biociencias; 2017

SAIC-SAIB-SAB-y otras sociedades

Epigenetic is the scientific discipline thatstudies the modifications that affect gene expression without altering the DNAsequence. These changes include DNA methylation, histone modifications, andalterations in the expression of small non-coding microRNAs (miRNA), which areinheritable and reversible. The importance of these miRNAs in cancer and itsrole in tumor growth, invasion, angiogenesis and immune evasion has beendemonstrated. Breast cancer is the leading cause of death from tumors in women,accounting for 17.8% of the total cancer incidence in Argentina. Overexpressionof HER-2 is present in approximately 30% of the different types of breastcancer, indicating greater malignancy and invasiveness among the differentclassifications of this cancer. For this reason HER-2 is an attractive targetfor a specific delivery. Expression of miR-205 is decreased in breast tumors.Therefore, we decided to use an aptamer against HER-2, the aptamer wasdeveloped using the standard SELEX technique. The primary sequence of the HB5 aptameris: 5?-AACCGCCCAAATCCCTAAGAGTCTGCACTTGTCATTTTGTATATGTATTTGGTTTTTGGCTCTCACAGACACACTACACGCACA-3?. The aptamer?s Kd for the union with the HER-2 peptide was 18.9 nM, At the 3?end of the aptamer an extension of 23 nucleotides was added in order to bindbiotin with mir-205. In this way, we want to increase its concentration incells with breast cancer, and try to decrease the tumor capacity of thesecells. The specific drug delivery system based on aptamers is a very attractivetherapeutic strategy, since it can increase the efficiency of thechemotherapeutic treatments and reduce the toxicity improving the quality oflife of the patient