title: Methyl angolensate from callus of Indian redwood induces cytotoxicity in human breast cancer cells.
abstract: OBJECTIVE
  Natural products discovered from medicinal plants have played an important role in the treatment of cancer. Methyl angolensate (MA), a tetranortriterpenoid obtained from the root callus of Indian Redwood tree, Soymida febrifuga Roxb. (A.Juss) was tested for its anticancer properties on breast cancer cells.
  
  
  METHODS
  Cell viability was tested using trypan blue, MTT and LDH assays. Tritiated thymidine assay and flowcytometry were used to study effect of MA on cell proliferation. The activation of apoptosis was checked by annexin V and JC-1 staining followed by FACS analysis. Immunoblotting analysis was used for studying expression of apoptotic and DNA double strand break repair proteins.
  
  
  RESULTS
  We find that MA inhibited the growth of breast cancer cell line, T47D in a time- and dose-dependent manner. MA treatment led to the inhibition of cell proliferation as detected by tritiated thymidine assay and flowcytometry. Further, MA treated cells exhibited typical apoptotic morphological changes and led to the accumulation of subG1 peak in cell cycle distribution. The induction of apoptosis was further confirmed both by annexin V staining and JC1 staining. We also find that MA activates MAP kinase pathway to induce apoptosis. Besides, we find a time dependent activation followed by degradation of DNA double-strand break repair proteins upon treatment with MA.
  
  
  CONCLUSIONS
  These results suggest that MA induces cytotoxicity in breast cancer cells. Further, the altered expression of DSB repair proteins in MA treated cells may control the induction of apoptosis in these cancer cells.
authors.affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore, India.
authors.forename: Kishore K
authors.initials: KK
authors.lastname: Chiruvella
authors.forename: Kuppusamy
authors.initials: K
authors.lastname: Panjamurthy
authors.forename: Bibha
authors.initials: B
authors.lastname: Choudhary
authors.forename: Omana
authors.initials: O
authors.lastname: Joy
authors.forename: Sathees C
authors.initials: SC
authors.lastname: Raghavan
keywords: alternative medicine; cancer therapeutics; double-strand breaks; intrinsic pathway of apoptosis; nonhomologous DNA end-joining