Radiochemotherapy of hepatocarcinoma via lentivirus–mediated transfer of human sodium iodide symporter gene and herpes simplex virus thymidine kinase gene

Radiofrequency hyperthermia-enhanced herpes simplex virus-thymidine kinase/ganciclovir direct intratumoral gene therapy of hepatocellular carcinoma

PURPOSE

To determine the feasibility of using radiofrequency hyperthermia (RFH) and to enhance the therapeutic effect of herpes simplex virus-thymidine kinase/ganciclovir (HSV-TK/GCV) for the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Human HCC cells (HepG2) were first transfected with lentivirus/luciferase. For both in vitro confirmation and in vivo validation, luciferase-labeled HCC cells and HCC tumour xenografts on mice received different treatments: (i) combination therapy of intratumoral HSV-TK/GCV-mediated gene therapy plus magnetic resonance imaging heating guidewire (MRIHG)-mediated RFH; (ii) gene therapy only; (iii) RFH only; and (iv) phosphate-buffered saline (PBS) as control. Cell proliferation was quantified. Tumour changes were monitored by ultrasound imaging and bioluminescence optical imaging before and at days 7 and 14 after treatments, which were correlated with subsequent histology.

RESULTS

In vitro, the lowest cell proliferation was seen in the combination therapy group compared with control groups (29 ± 6% vs. 56 ± 9%, 93 ± 4%, and 100 ± 5%, p < .05). Ultrasound imaging of treated animal xenografts showed smaller relative tumour volume in combination therapy group than those in three control groups (0.74 ± 0.19 vs. 1.79 ± 0.24, 3.14 ± 0.49 and 3.22 ± 0.52, p < .05). Optical imaging demonstrated significant decrease of bioluminescence signals of tumours in the combination therapy group, compared to those in three control groups (1.2 ± 0.1 vs. 1.9 ± 0.2% vs. 3.3 ± 0.6% vs. 3.5 ± 0.4%, p < .05). These imaging findings were correlated well with histologic confirmation.

CONCLUSION

RFH can enhance HSV-TK/GCV-mediated gene therapy of HepG2 cell line and mice human HCC xenografts, which may open new avenues for effective management of HCC using MR/RFH integrated interventional gene therapy.

Dual-modality imaging demonstrates the enhanced antitumoral effect of herpes simplex virus-thymidine kinase/ganciclovir plus gemcitabine combination therapy on cholangiocarcinoma

Herpes simplex virus-thymidine kinase/ganciclovir (HSV-TK/GCV) therapy is one of the most promising therapeutic strategies for the treatment of cholangiocarcinoma, which is the second most common hepatobiliary cancer. The aim of the present study was to evaluate the enhanced therapeutic effects of HSV-TK/GCV with gemcitabine on cholangiocarcinoma. QBC939 cholangiocarcinoma cells and mouse models of cholangiocarcinoma (established via tumor xenografts) received one of the following treatments: i) Gemcitabine therapy (3 µg/ml); ii) HSV-TK/GCV monotherapy; iii) HSV-TK/GCV + gemcitabine; and iv) control group, treated with phosphate-buffered saline. Cell proliferation was quantified using MTT assay and post-treatment tumor alterations were monitored using ultrasound imaging and optical imaging. For the in vitro experiments, the MTT assays demonstrated that the relative cell viabilities in the gene therapy, gemcitabine and gemcitabine + gene groups were 70.37±9.07, 52.64±8.28 and 34.21±6.63%, respectively. For the in vivo experiments, optical imaging indicated significantly decreased optical signals in the combination therapy group, as compared with the gemcitabine and gemcitabine + gene groups (1.68±0.74 vs. 2.27±0.58 and 2.87±0.82, respectively; Р<0.05). As demonstrated by ultrasound imaging, reduced tumor volumes were detected in the combination therapy group, as compared with the three control groups (114.32±17.17 vs. 159±23.74, 201.63±19.26 and 298.23±36.1 mm3, respectively; P<0.05). The results of the present study demonstrated that gemcitabine enhances the antitumoral effects of HSV-TK/GCV on cholangiocarcinoma, which may provide a novel therapeutic strategy for the management and treatment of cholangiocarcinoma using gemcitabine and gene therapy.

Potential Usefulness of Baculovirus-Mediated Sodium-Iodide Symporter Reporter Gene as Non-Invasively Gene Therapy Monitoring in Liver Cancer Cells: An In Vitro Evaluation

Primary liver cancer has one of the highest mortality rates of all cancers, and the main current treatments have a poor prognosis. This study aims to examine the efficiency of baculovirus vectors for transducing target gene into liver cancer cells and to evaluate the feasibility of using baculovirus vectors to deliver the sodium-iodide symporter (NIS) gene as a reporter gene through co-vector administration approach to monitor the expression of the target therapeutic gene in liver cancer gene therapy. We constructed (green fluorescent protein) GFP- and NIS-expressing baculovirus vectors (Bac-GFP and Bac-NIS), and measured the baculovirus transduction efficiency in HepG2 cells and other tumor cells (A549, SW1116 and 8505C), and it showed that the transduction efficiency and target gene expression level rose with increasing viral multiplicity of infection (MOI) in HepG2 cells, and HepG2 cells had a significantly higher transduction efficiency (60.8% at MOI = 200) than other tumor cells. Moreover, the baculovirus transduction was not cytotoxic to HepG2 cells at a higher MOI (MOI = 400). We also performed dynamic iodide uptake trials, and found that Bac-NIS-transduced HepG2 cells exhibited efficient iodide uptake which could be inhibited by sodium perchlorate (NaClO4). And we measured the correlation of fluorescent intensities and 125 I uptake amount in HepG2 cells after co-vector administration with Bac-NIS and Bac-GFP at different MOIs, and found a high correlation coefficient ( r2 = 0.8447), which provides a good basis for successfully evaluating the feasibility of baculovirus-mediated NIS reporter gene monitoring target gene expression in liver cancer therapy. Therefore, this study indicates that baculovirus vector is a potential vehicle for delivering therapeutic genes in studying liver cancer cells. And it is feasible to use a baculovirus vector to deliver NIS gene as a reporter gene to monitor the expression of target genes. It therefore provides an effective approach and a good basis for future baculovirus-mediated therapeutic gene delivering or therapeutic gene expression monitoring in liver cancer cells studies.

Combined RNA interference of adenine nucleotide translocase-2 and ganciclovir therapy in hepatocellular carcinoma

PURPOSE

The purpose of this study was to investigate the anticancer effects of combined RNA interference (RNAi) of the adenine nucleotide translocase-2 (ANT2) gene and ganciclovir (GCV) therapy for treatment of hepatocellular carcinoma cells (Huh 7) in an animal model.

METHODS

The Huh 7/NTG stable cell line was established by transfection of a vector with the human sodium iodide symporter (hNIS), HSV1-sr39 thymidine kinase (tk), and enhanced green florescent protein (EGFP) fusion gene into Huh 7 cells. mRNA expressions of these genes were evaluated by RT-PCR analysis. The functions of hNIS and HSV1-sr39tk were verified with (125)I uptake and (3)H-penciclovir (PCV) uptake tests. EGFP and hNIS expression was confirmed with confocal microscopy after immunocytochemical staining. We treated the tumor cells with ANT2 shRNA or GCV or both ANT2 shRNA and GCV and treated the in vivo mouse model with a Huh 7/NTG tumor xenograft. The therapeutic effects of the in vivo study were assessed with caliper measurements and gamma camera imaging using (99m)Tc-pertechnetate.

RESULTS

Huh 7/NTG cells showed a cell number-dependent increase in (125)I uptake and a 24-fold higher (3)H-PCV uptake compared to parent Huh 7 cells. Huh 7/NTG cells transfected with ANT2 shRNA had lower ANT2 mRNA expression and more impaired proliferation activity than cells transfected with scramble shRNA. Proliferation of Huh 7/NTG cells was also inhibited by GCV treatment. Combined GCV and ANT2 shRNA therapy further inhibited cell proliferation in the in vitro study. The combined therapy with GCV and ANT2 shRNA showed a further decrease in tumor growth in the mouse model.

CONCLUSIONS

Our results suggest that the combined RNA interference with ANT2 and GCV therapy inhibited hepatocellular carcinoma cell proliferation more than single GCV therapy or ANT2 shRNA therapy in vitro and in vivo. Therefore it could be applied treating incurable hepatocellular carcinoma.