Sulforaphane retards the growth of UM-UC-3 xenographs, induces apoptosis, and reduces survivin in athymic mice

Sulforaphane (SFN), an isothiocyanate that exists exclusively in cruciferous vegetables, may be the most promising preventive agent for bladder cancer (BC) to date. We previously observed that SFN dramatically inhibits human BC T24 cells in vitro. Our hypothesis is that SFN may attenuate BC growth. To test our hypothesis, we investigated the effect of SFN on human BC UM-UC-3 cell xenografts implanted into athymic mice. Sulforaphane extract was routinely prepared in our laboratory, and its content was measured with high-performance liquid chromatography. Athymic mice were injected subcutaneously with a UM-UC-3 cell suspension (2.0 x 10(6) cells/200 mu L per mouse) and randomly divided into 2 groups. The positive control group was orally gavaged with water, and the treatment group was orally administered SFN from broccoli sprout (12 mg/kg body weight) for 5 weeks. At the end of the experiment, tumor tissues were harvested and processed for hematoxylin and eosin staining and immunohistochemistry. The average tumor volume decreased from 4.1 +/- 1.67 cm(3) in the positive control mice to 1.5 +/- 0.72 cm(3) in the SFN-treated mice, evidencing an inhibitory rate of 63%. The SFN extract also reduced the appearance of tumors, including karyopyknosis and angiogenesis. Sulforaphane extract induced caspase 3 and cytochrome c expression but reduced the expression of survivin. Sulforaphane extract retards the growth of UM-UC-3 xenografts in vivo, confirming its future potential in BC therapy. (C) 2012 Elsevier Inc. All rights reserved.