Allyl Isothiocyanate Causes Mitotic Block , Loss of Cell Adhesion and Disrupted Cytoskeletal

Epidemiological evidence indicates that Brassica vegetables protect against colorectal cancer. Brassicas contain glucosinolates, the breakdown products of which exert antiproliferative effects against cancer cells. We have examined the effects of allyl isothiocyanate, a major breakdown product of the glucosinolate sinigrin, on proliferation and death of colorectal cancer cells. HT-29 colorectal cells were exposed to allyl isothiocyanate for 24 h and the number of adherent and detached cells determined. Both populations were analysed for cell cycle characteristics and examined by light and electron microscopy for features of apoptosis and mitosis. Evidence of apoptosis was also determined by flow cytometric analysis of Annexin V staining in the detached population of cells. Allyl isothiocyanate-treated cells were also stained for alpha tubulin. Treatment caused cells to round up after 7 h of exposure and subsequently detach. At 24 h these cells were blocked in mitosis. Detached AITC treated cells showed no signs of apoptosis as assessed by morphological features or by Annexin V staining but they did show evidence of disrupted tubulin. Allyl isothiocyanate inhibits proliferation of cancer cells by causing mitotic block associated with disruption of alpha-tubulin in a manner analogous to a number of chemotherapeutic agents. . To whom correspondence should be addressed UK Tel. 44(0)1603255343 Fax 44(0)1603507723 E-mail: [email protected]., ; a . # Oxford University Press ll rights reserved 200 arcinogenesis C Carcinogenesis Advance Access published March 19, 2004 at Penylvania State U niersity on Feruary 1, 2013 http://carcfordjournals.org/ D ow nladed from