Anticancer effect of XAV939 is observed by inhibiting lactose dehydrogenase A in a 3-dimensional culture of colorectal cancer cells.

XAV939, a tankyrase inhibitor, exerts an anticancer effect in 3-dimensional (3D) cultured SW480 cells, however this is not exhibited in 2-dimensional (2D) cultured SW480 cells. In the current study, XAV939 induced a 3.7-fold increase in cellular apoptosis in 3D culture but not in the 2D culture. However, no significant changes were indicated in cell cycle distribution in the 2D or 3D culture. Based on the observation that protein expression, which was associated with the glycolytic pathway, was increased in the 3D culture, the effect of XAV939 on the patterns of glycolytic protein expression was assessed. XAV939 was revealed to decrease lactose dehydrogenase A (LDHA) expression in 3D cultured SW480 cells, but only exerted a small effect in the 2D culture. The coadministration of XAV939 with the LDHA inhibitor FX11 decreased proliferation in 3D cultured SW480 cells compared with the single administration of FX11, while there was no additive effect in the 2D culture. The lactate assay also indicated that XAV939 decreased lactate secretion in the 3D cell culture but not in the 2D culture. These results suggest that XAV939 exerts an anticancer effect through inhibition of LDHA in the 3D culture.

Anti-inflammatory effect of a selective 11ß-hydroxysteroid dehydrogenase type 1 inhibitor via the stimulation of heme oxygenase-1 in LPS-activated mice and J774.1 murine macrophages.

11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) converts inactive cortisone to the active cortisol. 11ß-HSD1 may be involved in the resolution of inflammation. In the present study, we investigate the anti-inflammatory effects of 2-(3-benzoyl)-4-hydroxy-1,1-dioxo-2H-1,2-benzothiazine-2-yl-1-phenylethanone (KR-66344), a selective 11ß-HSD1 inhibitor, in lipopolysaccharide (LPS)-activated C57BL/6J mice and macrophages. LPS increased 11ß-HSD1 activity and expression in macrophages, which was inhibited by KR-66344. In addition, KR-66344 increased survival rate in LPS treated C57BL/6J mice. HO-1 mRNA expression level was increased by KR-66344, and this effect was reversed by the HO competitive inhibitor, ZnPP, in macrophages. Moreover, ZnPP reversed the suppression of ROS formation and cell death induced by KR-66344. ZnPP also suppressed animal survival rate in LPS plus KR-66344 treated C57BL/6J mice. In the spleen of LPS-treated mice, KR-66344 prevented cell death via suppression of inflammation, followed by inhibition of ROS, iNOS and COX-2 expression. Furthermore, LPS increased NFκB-p65 and MAPK phosphorylation, and these effects were abolished by pretreatment with KR-66344. Taken together, KR-66344 protects against LPS-induced animal death and spleen injury by inhibition of inflammation via induction of HO-1 and inhibition of 11ß-HSD1 activity. Thus, we concluded that the selective 11ß-HSD1 inhibitor may provide a novel strategy in the prevention/treatment of inflammatory disorders in patients.

Identification of a novel 11ß-HSD1 inhibitor from a high-throughput screen of natural product extracts.

Selective inhibitors of 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) have considerable potential as a treatment for metabolic syndrome including type 2 diabetes mellitus and obesity. To identify 11ß-HSD1 inhibitors, we conducted high-throughput screening (HTS) of active natural product extracts from the Korea Chemical Bank, including Tanshinone I, Tanshinone IIA, and flavanone derivatives, and 2- and 3-phenyl-4H-chromen-4-one. Then Tanshinone IIA and its derivatives were targeted for the development of a lead compound according to the HTS results. However, the mechanism for anti-adipogenic effect through 11ß-HSD1 enzyme inhibition by Tanshinone IIA is not clear. Tanshinone IIA (2a) concentration-dependently inhibited 11ß-HSD1 activity in human and mouse 11ß-HSD1 overexpressed cells and 3T3-L1 adipocytes. Tanshinone IIA (2a) also inhibited 11ß-HSD1 enzyme activities in murine liver and fats. Furthermore, Tanshinone IIA (2a)-suppressed adipocyte differentiation of cortisone-induced adipogenesis in 3T3-L1 cells was associated with the suppression of the cortisone-induced adipogenesis-specific markers mRNA and protein expression. In 3T3-L1 preadipocytes, Tanshinone IIA (2a)-inhibited cortisone induced reactive oxygen species formation in a concentration-dependent manner. Thus, these results support the therapeutic potential of Tanshinone IIA (2a) as a 11ß-HSD1 inhibitor in metabolic syndrome patients.

Lysophosphatidylcholine as an effector of fatty acid-induced insulin resistance.

The mechanism of FFA-induced insulin resistance is not fully understood. We have searched for effector molecules(s) in FFA-induced insulin resistance. Palmitic acid (PA) but not oleic acid (OA) induced insulin resistance in L6 myotubes through C-Jun N-terminal kinase (JNK) and insulin receptor substrate 1 (IRS-1) Ser307 phosphorylation. Inhibitors of ceramide synthesis did not block insulin resistance by PA. However, inhibition of the conversion of PA to lysophosphatidylcholine (LPC) by calcium-independent phospholipase A2 (iPLA2) inhibitors, such as bromoenol lactone (BEL) or palmitoyl trifluoromethyl ketone (PACOCF3), prevented insulin resistance by PA. iPLA2 inhibitors or iPLA2 small interfering RNA (siRNA) attenuated JNK or IRS-1 Ser307 phosphorylation by PA. PA treatment increased LPC content, which was reversed by iPLA2 inhibitors or iPLA2 siRNA. The intracellular DAG level was increased by iPLA2 inhibitors, despite ameliorated insulin resistance. Pertussis toxin (PTX), which inhibits LPC action through the G-protein coupled receptor (GPCR)/Gα(i), reversed insulin resistance by PA. BEL administration ameliorated insulin resistance and diabetes in db/db mice. JNK and IRS-1Ser307 phosphorylation in the liver and muscle of db/db mice was attenuated by BEL. LPC content was increased in the liver and muscle of db/db mice, which was suppressed by BEL. These findings implicate LPC as an important lipid intermediate that links saturated fatty acids to insulin resistance.

Synthesis and 11ß hydroxysteroid dehydrogenase 1 inhibition of thiazolidine derivatives with an adamantyl group.

A new series of thiazolidine derivatives with an adamantyl group was synthesized and evaluated for their ability to inhibit 11ß-hydroxysteroid dehydrogenase 1 (11ß-HSD1). Our initial compound 5a showed a weak inhibitory activity. Significant improvements in potency were achieved by substituent modification. The potent compound 8g (E) showed good in vitro inhibitory activity toward human 11ß-HSD1, selectivity toward 11ß-HSD2, metabolic stability, pharmacokinetic, and safety profile. Furthermore, this compound significantly inhibited 11ß-HSD1 activity in rat and monkey models, and showed improved glycemic control in KKAy mice.