Hepatoma cell-specific ganciclovir-mediated toxicity of a lentivirally transduced HSV-TkEGFP fusion protein gene placed under the control of rat alpha-fetoprotein gene regulatory sequences

Abstract

Suicide gene therapy combining herpes simplex virus thymidine kinase gene transfer and ganciclovir administration can be envisioned as a powerful therapeutical approach in the treatment of hepatocellular carcinoma; however, safety issues regarding transgene expression in parenchyma cells have to be addressed. In this study, we constructed LATKW, a lentiviral vector expressing the HSV-TkEGFP gene placed under the control of the promoter elements that control the expression of the rat alpha-fetoprotein, and assayed its specific expression in vitro in hepatocarcinoma and nonhepatocarcinoma human cell lines, and in epidermal growth factor stimulated human primary hepatocytes. Using LATKW, a strong expression of the transgene was found in transduced hepatocarcinoma cells compared to a very low expression in nonhepatocarcinoma human cell lines, as assessed by Northern blot, RT-PCR, FACS analysis and ganciclovir-mediated toxicity assay, and no expression was found in lentivirally transduced normal human hepatocytes. Altogether, these results demonstrate the possibility to use a lentivirally transduced expression unit containing the rat alpha-fetoprotein promoter to restrict the HSV-TK-mediated induced GCV sensitivity to human hepatocarcinoma cells.

Herpes simplex virus thymidine kinase-mediated suicide gene therapy for hepatocellular carcinoma using HIV-1-derived lentiviral vectors

“…Furthermore, even after EGF stimulation, the transduction efficiency, as measured by MFI, of human hepatocytes was still around 40 times lower than that of HCC cells (data not shown). At the end, transcriptional targetting using tumorspecific promoters, such as alphafoeteprotein promoter, may be developed to further increase the safety of lentiviruses [35].…”

Lentiviral vectors for cancer immunotherapy: transforming infectious particles into therapeutics

“…Human hepatocarcinoma cells have been transduced with lentiviruses containing a suicide gene under the control of the a-fetoprotein promoter resulting in specific destruction of these malignant cells. 57 Furthermore, a patient-derived prostate-specific antigen (PSA) promoter inserted into a lentiviral vector has driven efficient transgenic activity in prostate cells with satisfactory efficacy and specificity both in vitro and in vivo. 58 More recently, a PSA promoterbased HIV-1 vector has been used to deliver the diphtheria toxin A gene into prostate cancer cells, resulting in tissue-specific eradication of prostate cancer cells in cell culture and in a mouse tumor model.…”

The promise of lentiviral gene therapy for liver cancer

“…The authors acknowledged the significance of regulating transgene expression in various cell types [27]. LV do offer the potential for modulating transgene expression by substituting constitutive promoters within the vector with tissue-or tumor-specific promoters.…”