title: Ethanolic extract from Derris scandens Benth mediates radiosensitzation via two distinct modes of cell death in human colon cancer HT-29 cells.
abstract: Enhancing of radioresponsiveness of tumors by using radiosensitizers is a promising approach to increase the efficacy of radiation therapy. Recently, the ethanolic extract of the medicinal plant, Derris scandens Benth has been identified as a potent radiosensitizer of human colon cancer HT29 cells. However, cell death mechanisms underlying radiosensitization activity of D scandens extract have not been identified. Here, we show that treatment of HT-29 cells with D scandens extract in combination with gamma irradiation synergistically sensitizes HT-29 cells to cell lethality by apoptosis and mitotic catastrophe. Furthermore, the extract was found to decrease Erk1/2 activation. These findings suggest that D scandens extract mediates radiosensitization via at least two distinct modes of cell death and silences pro-survival signaling in HT-29 cells.
authors.affiliation: Radiobiology Research Unit, Department of Radiation Technology, Faculty of Allied Health Sciences, Naresuan University, Phitsanulok, Thailand E-mail : aruneeh@nu.ac.th, hematulin_a@yahoo.com.
authors.forename: Arunee
authors.initials: A
authors.lastname: Hematulin
authors.forename: Kornkanok
authors.initials: K
authors.lastname: Ingkaninan
authors.forename: Nanteetip
authors.initials: N
authors.lastname: Limpeanchob
authors.forename: Daniel
authors.initials: D
authors.lastname: Sagan
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy; D029866:Derris / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis; D019073:HT29 Cells; D006801:Humans; D020287:In Situ Nick-End Labeling; D059566:M Phase Cell Cycle Checkpoints / Q000187:drug effects* / Q000528:radiation effects; D010936:Plant Extracts / Q000494:pharmacology; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D011838:Radiation-Sensitizing Agents; D048049:Extracellular Signal-Regulated MAP Kinases