Cancer-specific binary expression system activated in mice by bacteriophage HK022 Integrase

Phage in cancer treatment - Biology of therapeutic phage and screening of tumor targeting peptide

INTRODUCTION

There is a constant drive to improve disease treatments. Much effort has been directed at identifying less immunogenic anti-cancer agents that produce fewer and less severe side effects. For more than a decade, bacteriophages have been discussed as an effective treatment for cancer with an exact mode of delivery.

AREAS COVERED

We review how bacteriophages are used in cancer treatment, the underlying therapeutic mechanisms, and the tumour attacking peptide screening process. The filamentous bacteriophages are an effective vehicle for delivering displayed peptides toward the tumour target. The peptide must be expressed at the appropriate coat protein, and the peptide must be effective enough to disrupt the complex cancer matrix. The present review also sheds light on the dynamic use of phage in cancer treatment, from detection and diagnostics to treatment.

EXPERT OPINION

Phage has a versatile role as a diagnostic and therapeutic tool. By acting as an appropriate recombinant drug, this phage has every potential to replace existing laborious, high capital investing therapies that may at many times result in failure or drastic side effects. One of the most significant challenges would be identifying tumour homing peptides. Although a few have been discovered, the most effective ones are yet to be determined. This therapeutic method plays a significant role in tumour therapy with high accuracy and efficiency, irrespective of the target location.

Anti-cancer binary system activated by bacteriophage HK022 integrase

The binary system presented in this work is based on the bacteriophage HK022 integrase recombinase that activates the expression of a silenced Diphtheria toxin gene, both controlled by the cancer specific hTERT promoter. Using a lung cancer mice model, assays of different apoptotic and anti-apoptotic factors have demonstrated that the Integrase based binary system is highly specific towards cancer cells and more efficient compared to the conventional mono system whose toxin is directly expressed under hTERT. In a mice survival test, this binary system demonstrated longer persistence compared to the untreated and the mono treated ones. The reason underlying the advantage of this binary system over the mono system seems to be an overexpression of various hTERT suppressing factors induced by the mono system.