title: Theaflavins depolymerize microtubule network through tubulin binding and cause apoptosis of cervical carcinoma HeLa cells.
abstract: Here we studied the antiproliferative activity of theaflavins in cervical carcinoma HeLa cells by investigating their effects on cellular microtubules and purified goat brain tubulin. Theaflavins inhibited proliferation of HeLa cells with IC(50) value of 110 ± 2.1 μg/mL (p = < 0.01), caused cell cycle arrest at G(2)/M phase and induced apoptosis with alteration of expression of pro- and antiapoptotic proteins. Along with these antiproliferative activities, theaflavins act as microtubule depolymerizers. Theaflavins disrupted the microtubule network accompanied by alteration of cellular morphology and also decreased the polymeric tubulin mass of the cells. The polymerization of cold treated depolymerized microtubules in HeLa cells was prevented in the presence of theaflavins. In vitro polymerization of purified tubulin into microtubules was also inhibited by theaflavins with an IC(50) value of 78 ± 2.43 μg/mL (P < 0.01). Thus, disruption of cellular microtubule network of HeLa cells through microtubule depolymerization may be one of the possible mechanisms of antiproliferative activity of theaflavins.
authors.affiliation: Department of Biotechnology and Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, WB 700019, India.
authors.forename: Subhendu
authors.initials: S
authors.lastname: Chakrabarty
authors.forename: Amlan
authors.initials: A
authors.lastname: Das
authors.forename: Abhijit
authors.initials: A
authors.lastname: Bhattacharya
authors.forename: Gopal
authors.initials: G
authors.lastname: Chakrabarti
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D044946:Biflavonoids / Q000494:pharmacology*; D002392:Catechin / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects*; D005455:Fluorescent Antibody Technique; D016195:G2 Phase / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D008870:Microtubules / Q000737:chemistry* / Q000187:drug effects; D058105:Polymerization / Q000187:drug effects; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*; D050257:Tubulin Modulators / Q000494:pharmacology
chemical_list: D044946:Biflavonoids; D014404:Tubulin; D050257:Tubulin Modulators; C056068:theaflavin; D002392:Catechin