title: Cell Cycle Modulation of MCF-7 and MDA-MB-231 by a Sub- Fraction of Strobilanthes crispus and its Combination with Tamoxifen.
abstract: BACKGROUND
  Cell cycle regulatory proteins are suitable targets for cancer therapeutic development since genetic alterations in many cancers also affect the functions of these molecules. Strobilanthes crispus (S. crispus) is traditionally known for its potential benefits in treating various ailments. We recently reported that an active sub-fraction of S. crispus leaves (SCS) caused caspase-dependent apoptosis of human breast cancer MCF-7 and MDA-MB-231 cells.
  
  
  METHODS
  Considering the ability of SCS to also promote the activity of the antiestrogen, tamoxifen, we further examined the effect of SCS in modulating cell cycle progression and related proteins in MCF-7 and MDA-MB-231 cells alone and in combination with tamoxifen. Expression of cell cycle- related transcripts was analysed based on a previous microarray dataset.
  
  
  RESULTS
  SCS significantly caused G1 arrest of both types of cells, similar to tamoxifen and this was associated with modulation of cyclin D1, p21 and p53. In combination with tamoxifen, the anticancer effects involved downregulation of ERα protein in MCF-7 cells but appeared independent of an ER-mediated mechanism in MDA-MB-231 cells. Microarray data analysis confirmed the clinical relevance of the proteins studied.
  
  
  CONCLUSIONS
  The current data suggest that SCS growth inhibitory effects are similar to that of the antiestrogen, tamoxifen, further supporting the previously demonstrated cytotoxic and apoptotic actions of both agents.
authors.affiliation: Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia Health Campus, Kubang Kerian, Kelantan, Malaysia E-mail : niksoriani@usm.my, sorianiyaacob@gmail.com.
authors.forename: Nik Soriani
authors.initials: NS
authors.lastname: Yaacob
authors.forename: Nik Nursyazni
authors.initials: NN
authors.lastname: Nik Mohamed Kamal
authors.forename: Kah Keng
authors.initials: KK
authors.lastname: Wong
authors.forename: Mohd Nor
authors.initials: MN
authors.lastname: Norazmi
mesh_terms: D027901:Acanthaceae / Q000737:chemistry*; D000971:Antineoplastic Combined Chemotherapy Protocols; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects*; D018797:Cell Cycle Proteins / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D006801:Humans; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D013629:Tamoxifen / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D018797:Cell Cycle Proteins; D004965:Estrogen Antagonists; D010936:Plant Extracts; D013629:Tamoxifen