Purpose: The clinically relevant histone deacetylase inhibitors (HDI) valproic acid (VPA) and suberoylanilide hydroxamic acid exert variable antitumor activities but increase therapeutic efficacy when combined with other agents. The natural endogenous ligand of peroxisome proliferator-activated receptor γ 15-deoxy-Δ 12,14 -prostaglandin J 2 (15d-PGJ 2 ) is a potent antineoplastic agent. Therefore, we investigated whether these HDIs in combination with 15d-PGJ 2 could show synergistic antitumor activity in colon cancer DLD-1 cells. Experimental Design: Cell viability was determined using a Cell Counting Kit-8 assay. Apoptosis and reactive oxygen species (ROS) generation were determined using flow cytometry analysis. Western blotting and real-time reverse transcription-PCR analysis were carried out to investigate the expression of apoptosis-related molecules. Mice bearing DLD-1 xenograft were divided into four groups (n = 5) and injected everyday (i.p.) with diluent, VPA (100 mg/kg), 15d-PGJ 2 (5 mg/kg), or a combination for 25 days.Results: HDI/15d-PGJ 2 cotreatments synergistically induced cell death through caspase-dependent apoptosis in DLD-1 cells. Moreover, HDIs/15d-PGJ 2 caused histone deacetylase inhibition, leading to subsequent ROS generation and endoplasmic reticulum stress to decrease the expression of antiapoptotic molecules Bcl-X L and XIAP and to increase that of proapoptotic molecules CAAT/enhancer binding protein homologous protein and death receptor 5. Additionally, VPA/15d-PGJ 2 cotreatment induced ROS-dependent apoptosis in other malignant tumor cells and was more effective than a VPA or 15d-PGJ 2 monotherapy in vivo.Conclusions: Cotreatments with the clinically relevant HDIs and the endogenous peroxisome proliferator-activated receptor γ ligand 15d-PGJ 2 are promising for the treatment of a broad spectrum of malignant tumors. Clin Cancer Res; 16(8); 2320-32. ©2010 AACR.

Pruritus is known to be a common complication in hepatitis patients, but the exact frequency and degree are not fully elucidated. Thus, we evaluated pruritus of 450 patients with chronic liver disease at our hospital. Pruritus was observed in 240 (53%) of the patients. Pruritus was significantly associated with males (OR = 1.51, P = 0.038) and patients with alkaline phosphatase (ALP) ≥ 200 U/L (OR = 1.56, P = 0.0495) and was significantly less in HBsAg-positive patients (OR = 0.449, P = 0.004). Seasonally, there was no difference in the frequency of pruritus between summer and winter. Of the 24 refractory pruritus patients treated with nalfurafine, 17 (71%) indicated improvement of itch, which is defined as a decrease in the visual analog scale score ≥ 30 mm. Pruritus was improved by nalfurafine both during daytime and nighttime in the Kawashima’s scores evaluation. All patients who received nalfurafine exhibited improved Kawashima’s scores ≥ 1 point during the daytime or nighttime. In conclusion, pruritus occurred in > 50% of patients with chronic liver disease, and predictors of pruritus were males and ALP ≥ 200 U/L. Nalfurafine may be useful for pruritus, regardless of whether daytime or nighttime.

Prolactin (PRL) is an important regulator of multiple biological functions, and the control of PRL expression integrates a wide spectrum of molecules throughout vertebrates. PRL-releasing peptide (PrRP) seems to be an essential stimulator of PRL transcription and secretion in teleost pituitary and peripheral organs. In the amphibious euryhaline mudskipper, the localization of mRNA levels of PrRP and PRL as well as their regulation during acclimation to different environments are closely related. The presence of PrRP-PRL axes in the peripheral organs might suggest an ancient history of this axis prior to the evolution of the hypothalamus-pituitary, and it is possible that the PrRP is an original and primary regulator of PRL. In the euryhaline fishes, the permeability of gut of seawater-acclimated fish is generally greater than that of the freshwater (FW)-acclimated fish. The modification in the epithelial cell renewal system may play an important role in regulation of the permeability. PRL induces the cell proliferation during FW acclimation, whereas cortisol stimulates both cell proliferation and apoptosis. Indeed, a large proportion of the various actions of PRL seem to be associated directly or indirectly with cell proliferation and/or apoptosis, which might be a primary function of PRL.

Abstract. The administration of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is one of the expected cancer therapeutics. However, improvements are required in therapies against TRAIL-resistant tumor cells. We report, here, that the anti-obesity drug orlistat enhances the sensitivity to TRAIL in hormone-refractory prostate cancer (HRPC) cells through two different pathways. The combination of orlistat and TRAIL remarkably induced apoptosis in TRAIL-resistant HRPC, DU145 and PC3 cells. Orlistat induced the expression of death receptor (DR) 5, which is one of the TRAIL receptors, at both the mRNA and protein levels. The suppression of DR5 with siRNA reduced the apoptosis induced by the combination of orlistat and TRAIL, suggesting that the apoptosis was at least partially due to the upregulation of DR5. Although the upregulation by orlistat of CHOP at both mRNA and protein levels was observed in both cell lines, the activation of the DR5 promoter in DU145 cells was CHOP-dependent, but that in PC3 cells was CHOP-independent. Moreover, orlistat induced reactive oxygen species (ROS), and a ROS scavenger diminished the sensitivity to TRAIL through the suppression of CHOP and DR5 expression in both cell lines. These results suggest that there are two pathways of upregulation of DR5 by orlistat, which are the ROS-CHOP pathway and the ROS-direct pathway. In conclusion, orlistat promotes the sensitivity to TRAIL by ROS-mediated pathways in prostate cancer cells, especially in TRAIL-resistant cells. We believe that the combination of orlistat and TRAIL in HRPC is promising as a new chemotherapeutic strategy.