MGN-3/Biobran, modified arabinoxylan from rice bran, sensitizes human breast cancer cells to chemotherapeutic agent, daunorubicin

Background: MGN-3/Biobran, a modified form of arabinoxylan from rice bran, is a potent biological response modifier (BRM). Our previous studies demonstrated that MGN-3 sensitizes human leukemia cells to death receptor [CD95]-induced apoptosis [Ghoneum M, Gollapudi S. MGN-3 sensitizes human T cell leukemia cells to death receptor (CD95)-induced apoptosis. Cancer Lett 2003;201:41–9]. In this study, we evaluated the chemo-sensitizing activity of MGN-3 against human breast cancer cells (BCCs) in vitro. Methods: BCCs (MCF-7 and HCC70 cells) were cultured with different concentrations of daunorubicin (DNR) (from 1 × 10−9 to 1 × 10−6 M) in the presence or absence of selected concentrations of MGN-3 (100–1000 μg/ml) for 3 days. Cancer cell survival was determined by MTT assay and drug accumulation was determined by flow cytometry. Results: Treatment with MGN-3 increased susceptibility of BCCs to DNR (5.5-fold for MCF-7 and 2.5-fold for HCC70 cells) as compared to BCCs treated with DNR alone. The sensitizing effect of MGN-3 was associated with increased accumulation of DNR in cancer cells. Conclusions: Our data demonstrate that MGN-3 is an effective chemo-sensitizer and may represent a potential novel adjuvant for the treatment of breast cancer.