STAT3 inhibition with Galiellalactone effectively targets the prostate cancer stem-like cell population."

Cancer stem cells (CSCs) are a small subpopulation of quiescent cells with the potential to differentiate into tumor cells. CSCs are involved in tumor initiation and progression and contribute to treatment failure through their intrinsic resistance to chemo- or radiotherapy, thus representing a substantial concern for cancer treatment. Prostate CSCs’ activity has been shown to be regulated by the transcription factor Signal Transducer and Activator of Transcription 3 (STAT3). Here we investigated the effect of galiellalactone (GL), a direct STAT3 inhibitor, on CSCs derived from prostate cancer patients, on docetaxel-resistant spheres with stem cell characteristics, on CSCs obtained from the DU145 cell line in vitro and on DU145 tumors in vivo. We found that GL significantly reduced the viability of docetaxel-resistant and patient-derived spheres. Moreover, CSCs isolated from DU145 cells were sensitive to low concentrations of GL, and the treatment with GL suppressed their viability and their ability to form colonies and spheres. STAT3 inhibition down regulated transcriptional targets of STAT3 in these cells, indicating STAT3 activity in CSCs. Our results indicate that GL can target the prostate stem cell niche in patient-derived cells, in docetaxel-resistant spheres and in an in vitro model. We conclude that GL represents a promising therapeutic approach for prostate cancer patients, as it reduces the viability of prostate cancer-therapy-resistant cells in both CSCs and non-CSC populations

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)