Abstract 5704: Curcumin-folate conjugate for increased bioavailability and targeted delivery of curcumin to cancer cells

Abstract

Abstract Specific types of high risk Human Papillomavirus (HR-HPV) types, particularly the HPV type 16 and HPV 18 are known to cause cervical cancer. The expression of two viral oncogenes E6 and E7 responsible for tumorigenic transformation, is mainly dependent on specific host-cell transcription factor, Activator Protein 1 (AP-1) which acts as a signaling epicenter for cervical cancer. Although recently two prophylactic HPV vaccines have been developed, there is no therapeutic molecule available for the treatment of cervical lesions. We demonstrate that Curcumin (Diferuloylmethane), a yellow pigment, used in traditional medicines and present in the dietary spice turmeric (Curcuma longa), can selectively down regulate HPV 18 transcription as well as AP-1 binding activity. Curcumin can also reverse the expression dynamics of c-fos and fra-1 in tumorigenic HeLa cells by mimicking their expression pattern in normal cells. But the bioavailability of curcumin is extremely poor due to its hydrophobicity, rapid metabolism and lack of specificity in targeting cancer cells. Therefore, a folic acid-curcumin conjugate for mutation has been developed by attaching one molecule of curcumin with two molecules of folic acid (Cur-2FA) to make curcumin hydrophilic, enhance its bioavailability and to target only cancer cells which specifically express high level of folate receptors. The effect of both native curcumin and Cur-2FA on HPV and AP-1 has been analyzed in HPV positive cervical cancer and HPV negative breast cancer cell lines, by band shift assay, confocal microscopy, flow cytometry and western blotting including their cytotoxic potential and targeted cellular uptake of curcumin. In comparison to native curcumin, curcumin-2FA has been found to be atleast two times more effective in inducing down regulation of HPV transcription, AP-1 activity and expression of its components particularly c-fos and fra-1. Curcumin-2FA was found to be more potent than curcumin in inducing apoptosis, inhibits tumor cell proliferation and Cur-2FA conjugate was specifically taken up by cancer cells. In mice, curcumin-2FA was more bioavailable and had a longer half-life than curcumin. We demonstrate that this nontoxic low molecular weight curcumin-2Folic acid conjugate formulation specifically targets cancer cells which overexpress high affinity folate receptor and enhanced cellular uptake facilitating increased bioavailability and targeted delivery to cancer cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5704. doi:1538-7445.AM2012-5704