Combined treatment of pancreatic cancer xenograft with 90Y-ITGA6B4-mediated radioimmunotherapy and PI3K/m TOR inhibitor

AIM To investigate the therapeutic effect of combined integrin α6β4-targeted radioimmunotherapy(RIT) and PI3 K/m TOR inhibitor BEZ235 in a pancreatic cancer model.METHODS Phosphorylation of Akt, m TOR, the downstream effectors eukaryotic initiation factor 4 E binding protein 1(4 EBP1) and S6 ribosomal protein(S6) were evaluated in Bx PC-3 human pancreatic cancer cells treated with Yttrium-^(90)(^(90) Y) labeled anti-integrin α6β4 antibody(ITGA6 B4) and BEZ235 by western blotting. The cytotoxic effect of BEZ235 was investigated using a colony formation assay. Therapeutic efficacy enhancement by oral BEZ235 administration was assessed using mice bearing Bx PC-3 xenograft tumors. Tumor volume measurements and immunohistochemical analyses(cell proliferation marker Ki-67, DNA damage marker p-H2 AX and p-4 EBP1 staining) of tumors were performed for evaluation of combined treatment with ^(90) Y-ITGA6 B4 plus BEZ235, or each arm alone.RESULTS We found that phosphorylation of Akt(p-Akt), 4 EBP1(p-4 EBP1) and S6(p-S6) was inhibited by BEZ235. Colony formation in Bx PC-3 cells was additively suppressed by the combination of ^(90) Y-ITGA6 B4 and BEZ235. Pretreatment with BEZ235 before ^(90) Y-ITGA6 B4 exposure resulted in significant reduction of cells plating efficiency(PE)(0.54 ± 0.11 vs 2.81 ± 0.14 with 185 k Bq/m L ^(90) Y-ITGA6 B4 exposure, P < 0.01; 0.39 ± 0.08 vs 1.88 ± 0.09 with 370 k Bq/m L ^(90) Y-ITGA6 B4 exposure, P < 0.01) when 5 × 10~3 cells per dish were plated. In vivo, the combined treatment with ^(90) Y-ITGA6 B4 plus BEZ235 enhanced the inhibition of tumor growth and statistically significant differences of relative tumor volume were observed for 27 d after the treatment start date when compared with the ^(90) Y-ITGA6 B4 single injection treatment(1.03 ± 0.38 vs 1.5 ± 0.15 at Day 27, P < 0.05), and for 41 d when compared with the BEZ235 treatment alone(1.8 ± 0.7 vs 3.14 ± 1.19 at Day 41, P < 0.05). Tumors from treatment groups showed reduction in volumes, decreased Ki-67-positive cells, increased p-H2 AX-positive cells and decreased p-4 EBP1 expression. CONCLUSION The therapeutic efficacy of ^(90) Y-ITGA6 B4-RIT can be improved by combining with dual PI3 K and m TOR inhibitor, BEZ235, in a pancreatic cancer model suggesting potential clinical application.

Biologics:how far can they go in Crohn’s disease?

Crohn’s disease is a chronic gastrointestinal inflammatory disorder,characterized by episodes of relapsing and remitting flares.As the disease mechanism becomes better elucidated,there is a significant increase in the number of available biologic therapies.This article summarizes and synthesizes current Food and Drug Administration-approved biological therapy for Crohn’s disease and examines the positioning of medical therapy as emerging biologics break onto the market.

Biological therapy for ulcerative colitis

Ulcerative colitis(UC)is a major form of inflammatory bowel disease(IBD)worldwide.Better understanding of the pathogenesis of UC has led to the development of novel therapeutic agents that target specific mediators of the inflammatory cascade.A number of biological agents have been approved by the U.S.Food and Drug Administration(FDA)for the treatment of UC and several more are currently in various phases of drug development.The commonly used agents include TNFa antagonists(e.g.infliximab,adalimumab,and golimumab)and anti-integrin agents(vedolizumab).These biological agents have profoundly influenced the management of UC patients,especially those with refractory disease.This paper reviews the currently available knowledge and evidence for the use of various biological agents in the treatment of UC.