3,3'-Diindolylmethane

Cell experiment:

The human prostate adenocarcinoma cell lines LNCaP-FGC and PC-3 are grown as adherent monolayers in 10% FBS-DMEM, supplemented with 4.0 g/L glucose and 3.7 g/L sodium bicarbonate in a humidified incubator at 37°C and 5% CO2, and passaged at ~80% confluency. Cultures used in subsequent experiments are at less than 40 passages. Cells grown in stripped conditions are in 5% DCC-FBS-DMEM base supplemented with 4 g/L glucose, 3.7 g/L sodium bicarbonate, and 0.293 g/L L-glutamine. Before the beginning of the treatments, cells are depleted of androgen for 4-7 days in medium composed of DMEM base without phenol red and with 4 g/L glucose and 3.7 g/L sodium bicarbonate. During the depletion period, medium is changed every 48 h. Treatments are administered by the addition of 1 μL of a 1,000-fold concentrated solution of 3,3'-Diindolylmethane in Me2SO/mL of medium. Once the treatment period started, medium is changed daily to counter possible loss of readily metabolized compounds[1].

Animal experiment:

Mice[2] Four-week-old female SPF/VAF immunodeficient mice are injected subcutaneously (s.c.) into the right flank with 0.1 mL Matrigel containing 3.5×106 human gastric cancer cells (SNU-484). The mice are randomized into 2 groups 1 week after tumor implantation: i) the untreated control group (n=5, DMSO in 50 μL PBS daily) and ii) the 3,3'-Diindolylmethane-treated group (n=5, 10 mg/kg in 50 μL PBS once daily). Gastric primary tumors are excised, and the final tumor volume is measured once every 3 days using a caliper and calculated as (width)2×length/2. The experiment is terminated on day 39. Half of the tumor tissue is prepared for western blotting and the other half is snap frozen in liquid nitrogen and stored at −80°C.

References:

[1]. Le HT, et al. Plant-derived 3,3'-Diindolylmethane is a strong androgen antagonist in human prostate cancer cells. J Biol Chem. 2003 Jun 6;278(23):21136-45.
[2]. Li XJ, et al. 3,3'-Diindolylmethane suppresses the growth of gastric cancer cells via activation of the Hippo signaling pathway. Oncol Rep. 2013 Nov;30(5):2419-26.