Interleukin-8 signaling attenuates TRAIL- and chemotherapy-induced apoptosis through transcriptional regulation of c-FLIP in prostate cancer cells

Chemotherapy-induced interleukin-8 (IL-8) signaling reduces the sensitivity of prostate cancer cells to undergo apoptosis. In this study, we investigated how endogenous and drug-induced IL-8 signaling altered the extrinsic apoptosis pathway by determining the sensitivity of LNCaP and PC3 cells to administration of the death receptor agonist tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL induced concentration-dependent decreases in LNCaP and PC3 cell viability, coincident with increased levels of apoptosis and the potentiation of IL-8 secretion. Administration of recombinant human IL-8 was shown to increase the mRNA transcript levels and expression of c+FLIPL and c-FLIPS, two isoforms of the endogenous caspase-8 inhibitor. Pretreatment with the CXCR2 antagonist AZ10397767 significantly attenuated IL-8-induced c-FLIP mRNA up-regulation whereas inhibition of androgen receptor- and/or nuclear factor-kappa B-mediated transcription attenuated IL-8-induced c-FLIP expression in LNCaP and PC3 cells, respectively. Inhibition of c-FLIP expression was shown to induce spontaneous apoptosis in both cell lines and to sensitize these prostate cancer cells to treatment with TRAIL, oxaliplatin, and docetaxel. Coadministration of AZ10397767 also increased the sensitivity of PC3 cells to the apoptosis-inducing effects of recombinant TRAIL, most likely due to the ability of this antagonist to block TRAIL- and IL-8-induced up-regulation of c-FLIP in these cells. We conclude that endogenous and TRAIL-induced IL-8 signaling can modulate the extrinsic apoptosis pathway in prostate cancer cells through direct transcriptional regulation of c-FLIP. Therefore, targeted inhibition of IL-8 signaling or c-FLIP expression in prostate cancer may be an attractive therapeutic strategy to sensitize this stage of disease to chemotherapy.

Vaginal delivery of the recombinant HIV-1 clade-C trimeric gp140 envelope protein CN54gp140 within novel rheologically structured vehicles elicits specific immune responses

Rheologically structured vehicle (RSV) gels were developed as delivery systems for vaginal mucosal vaccination with an HIV-1 envelope glycoprotein (CN54gp140). RSVs comprised a mucoadhesive matrix forming and vaginal fluid absorbing polymer. The mucoadhesive and rheological properties of the RSVs were evaluated in vitro, and the distribution, antigenicity and release of CN54gp140 were analysed by ELISA. CN54gp140 was uniformly distributed within the RSVs and continuously released in vitro in an antigenically intact form over 24 h. Vaginal administration to rabbits induced specific serum IgG, and IgG and IgA in genital tract secretions. The RSVs are a viable delivery modality for vaginal immunization.

Vitamins C and E for prevention of pre-eclampsia in women with type 1 diabetes (DAPIT): a randomised placebo-controlled trial.

Background
Results of several trials of antioxidant use during pregnancy have not shown a reduction in pre-eclampsia, but the eff ect in women with diabetes is unknown. We aimed to assess whether supplementation with vitamins C and E reduced incidence of pre-eclampsia in women with type 1 diabetes.

Methods
We enrolled women from 25 UK antenatal metabolic clinics in a multicentre randomised placebo-controlled trial. Eligibility criteria were type 1 diabetes preceding pregnancy, presentation between 8 weeks’ and 22 weeks’ gestation, singleton pregnancy, and age 16 years or older. Women were randomly allocated in a 1:1 ratio to receive1000 mg vitamin C and 400 IU vitamin E (a-tocopherol) or matched placebo daily until delivery. The randomisation sequence was stratifi ed by centre with balanced blocks of eight patients. All trial personnel and participants were masked to treatment allocation. The primary endpoint was pre-eclampsia, which we defi ned as gestational hypertension with proteinuria. Analysis was by modifi ed intention to treat. This study is registered, ISRCTN27214045.

Findings
Between April, 2003, and June, 2008, 762 women were randomly allocated to treatment groups (379 vitamin supplementation, 383 placebo). The primary endpoint was assessed for 375 women allocated to receive vitamins, and 374 allocated to placebo. Rates of pre-eclampsia did not differ between vitamin (15%, n=57) and placebo (19%, 70)groups (risk ratio 0·81, 95% CI 0·59–1·12). No adverse maternal or neonatal outcomes were reported.

Interpretation
Supplementation with vitamins C and E did not reduce risk of pre-eclampsia in women with type 1 diabetes. However, the possibility that vitamin supplementation might be benefi cial in women with a low antioxidant status at baseline needs further testing.

Optimization of novel acyl pyrrolidine inhibitors of hepatitis C virus RNA-dependent RNA polymerase leading to a development candidate

Optimization of a pyrrolidine-based template using structure-based design and physicochemical considerations has provided a development candidate 20b (3082) with submicromolar potency in the HCV replicon and good pharmacokinetic properties.

Identification of GSK625433: A novel clinical candidate for the treatment of hepatitis C.

Hepatitis C is an infection of the liver caused by a pos. single-stranded RNA virus (HCV) which affects 170 million people worldwide. It is responsible for 40-60% of all liver disease and is the major cause of liver transplants in the United States. The HCV NS5B gene encodes the viral RNA-dependent RNA polymerase which is essential for HCV replication. We have previously reported the identification of acylpyrrolidines as potent inhibitors of NS5B; however their activity is attenuated against genotype 1a. The design of improved broader-spectrum compds., capable of effective inhibition of both genotypes 1b and 1a is desirable. An understanding of the binding site and genotype sequence differences was utilized to design compds. with greatly enhanced genotype 1a and 1b potency. Our studies led to the identification of GSK625433, a potent, homochiral inhibitor of these HCV genotypes in both enzyme and sub-genomic replicon cell-based assays. GSK625433 has a good pharmacokinetic profile in pre-clin. animal species, enabling progression to clin. evaluation.