A Gelatinases-targeting scFv-based Fusion Protein Shows Enhanced Antitumour Activity with Endostar against Hepatoma

Single-Chain Fragment Variable: Recent Progress in Cancer Diagnosis and Therapy

Simple Summary

Recombinant antibody fragments have shown remarkable potential as diagnostic and therapeutic tools in the fight against cancer. The single-chain fragment variable (scFv) that contains the complete antigen-binding domains of a whole antibody, has several advantages such as a high specificity and affinity for antigens, a low immunogenicity, and the proven ability to penetrate tumor tissues and diffuse. This review provides an overview of the current studies on the principle, generation, and applications of scFvs, particularly in the diagnosis and therapy of cancer, and underscores their potential use in clinical trials.

Abstract

Cancer remains a public health problem worldwide. Although conventional therapies have led to some excellent outcomes, some patients fail to respond to treatment, they have few therapeutic alternatives and a poor survival prognosis. Several strategies have been proposed to overcome this issue. The most recent approach is immunotherapy, particularly the use of recombinant antibodies and their derivatives, such as the single-chain fragment variable (scFv) containing the complete antigen-binding domains of a whole antibody that successfully targets tumor cells. This review describes the recent progress made with scFvs as a cancer diagnostic and therapeutic tool, with an emphasis on preclinical approaches and their potential use in clinical trials.

An arginine-rich cell penetrating peptide contained anti-gelatinase scFv-LDM fusion protein shows potent antitumor efficacy in pancreatic cancer

Pancreatic cancer (PC) is one of the most dangerous cancers with less than 5% survival rate in 5 years. This study was to evaluate the antitumor activities of dFv-LDP-AE and dFv-R-LDP-AE, two energized fusion protein targeting gelatinases, on pancreatic cancer. The fusion protein dFv-LDP-AE consists of two tandem anti-gelatianses scFv and an enediyne antibiotic lidamycin (LDM) for receptor binding and cell killing. To improve the penetration capability, the fusion protein dFv-LDP-AE was integrated with an arginine-rich cell penetrating peptide (Arg)₉ and then generated the fusion protein dFv-R-LDP-AE. The current study demonstrated that dFv-LDP and dFv-R-LDP had high affinity with the antigen gelatinases and PC cells, the integration of (Arg)₉ could increase the penetration rate of fusion protein in SW-1990 and PANC-1 cells. After enediyne-energized with chromophore of lidamycin, the energized fusion protein dFv-LDP-AE and dFv-R-LDP-AE showed potent cytotoxicity to PC cells and could induced the robust cell apoptosis and necrosis in vitro. Western blot showed that dFv-R-LDP-AE could increase PARP cleavage, and inhibited the expression of VEGF, Cyclin D1, Cox-2 and Bcl-2 in SW-1990 and PANC-1 cells. In vivo, at a tolerated dosage, dFv-LDP, dFv-LDP-AE and dFv-R-LDP-AE inhibited tumor growth by 20.42%, 56.31% (P < 0.01, compared to that of control) and 74.2% (P < 0.05, compared to that of dFv-LDP-AE) in pancreatic cancer SW-1990 xenografted mice, respectively. Moreover, the results of in vivo optical imaging showed that fusion protein dFv-R-LDP displayed prominent accumulation in the tumor in SW-1990 xenografted mice and Capan-2 orthotopic transplanted mice. These results showed that dFv-R-LDP-AE possessed potent antitumor efficacy on PC, which indicating it could be a promising candidate for targeting therapy of PC.