Eradication of hepatocellular carcinoma xenografts by radiolabelled, lipiodol-inducible gene therapy

Local Retention and Combination Effects of Biocompatible Doxorubicin-Loaded and Radioiodine-Labeled Microhydrogels in Cancer Therapy

I-131-labeled chitosan microhydrogels (I-131-CMH) that are retained at an injection site without leaking free I-131 into normal tissue can provide opportunities to improve cancer therapy. This study focuses on the development of doxorubicin-loaded I-131-CMH (Dox-I-131-CMH) for use in radiochemotherapy against cancer. The radiolabeling of I-131-CMH was found to be stable over a period of 2 weeks with no disassociation of free I-131, and Dox showed a sustained release from the CMH. When I-131-CMH were injected into the thigh muscle or tumor tissue, in vivo gamma imaging showed a retention at the injection site with no significant leakage of I-131 into other areas of normal tissue, and after an intrahepatic arterial injection, I-131-CMH were selectively retained in the liver. Dox-I-131-CMH had significant synergistic therapeutic effects of radiation and chemotherapy on mouse breast cancer models. In this regard, Dox-I-131-CMH may be a new alternative agent for cancer therapy.

Baculovirus vector-mediated transfer of sodium iodide symporter and plasminogen kringle 5 genes for tumor radioiodide therapy

Background

Both tumor cells and their supporting endothelial cells should be considered for targeted cell killing when designing cancer treatments. Here we investigated the feasibility of combining radioiodide and antiangiogenic therapies after baculovirus-mediated transfer of genes encoding the sodium iodide symporter (NIS) and plasminogen kringle 5 (K5).

Methods

A recombinant baculovirus containing the NIS gene under control of the human telomerase reverse transcriptase (hTERT) promoter and the K5 gene driven by the early growth response 1 (Egr1) promoter was developed. Dual-luciferase reporter assay was performed to confirm the activation of hTERT transcription. NIS and K5 gene expression were identified by Western blot and Real-Time PCR. Functional NIS activity in baculovirus-infected Hela cells was confirmed by the uptake of ¹²⁵I and cytotoxicity of ¹³¹I. The apoptotic effect of ¹³¹I-induced K5 on baculovirus-infected human umbilical vein endothelial cells (HUVECs) was analyzed by a flow cytometry-based assay. In vivo, NIS reporter gene imaging and therapeutic experiments with ¹³¹I were performed. Finally, the microvessel density (MVD) in tumors after treatment was determined by CD31 immunostaining.

Results

The activation of hTERT transcription was specifically up-regulated in tumor cells. NIS gene expression markedly increased in baculovirus-infected HeLa cells, but not in MRC5 cells. The Hela cells showed a significant increase of ¹²⁵I uptake, which was inhibited by NaClO₄, and a notably decreased cell survival rate by ¹³¹I treatment. Expression of the K5 gene induced by ¹³¹I was elevated in a dose- and time-dependent manner and resulted in the apoptosis of HUVECs. Furthermore, ¹³¹I SPECT imaging clearly showed cervical tumor xenografts infected with recombinant baculovirus. Following therapy, tumor growth was significantly retarded. CD31 immunostaining confirmed a significant decrease of MVD.

Conclusion

The recombinant baculovirus supports a promising strategy of NIS-based raidoiodide therapy combined with K5-based antiangiogenic therapy by targeting both the tumor and its supporting vessels.

Antitumoural hydroxyapatite nanoparticles-mediated hepatoma-targeted trans-arterial embolization gene therapy: in vitro and in vivo studies

BACKGROUND/AIMS

Absence of curative treatment creates urgent need for new strategies for unresectable hepatoma. Based on former discoveries of good liver cell compatibility, safety and tumour-specific inhibition of hydroxyapatite nanoparticles (nHAP), this work tries to make nHAP serve as gene vector in the hepatoma-targeted trans-arterial embolization (TAE) gene therapy to elevate and synergize the therapeutic efficacy of TAE and target gene therapy.

METHOD

Following dosage and ratio optimization, polypolex formed by surface modified nHAP and p53 expressing plasmid was applied in vitro for human hepatoma HePG2 cell, and then in vivo for rabbit hepatic VX2 tumour by injection of polypolex/lipodoil emulsion to the hepatic artery in a tumour-target manner.

RESULTS

In vitro, the polypolex transfected only about 5% HepG2 cells, but can elevate the inhibition of its growth and apoptosis in a much more degree while keeping safe to the normal hepatocyte line, L02. In vivo, the emulsion, with better dispersion than the polypolex and more specific tumour-target than lipiodol, mediated specific 4% p53 expression and antitumoural nanoparticle retention in the target tumour site, also significantly reduced tumour growth and prolonged the animal survival times more than the lipiodol (P < 0.05).

CONCLUSIONS

In all, this new treatment based on nHAP can enhance therapeutic effect of HCC safely both in vitro and in vivo.

Virosome: a novel vector to enable multi-modal strategies for cancer therapy

Despite advancements in treatments, cancer remains a life-threatening disease that is resistant to therapy. Single-modal cancer therapy is often insufficient to provide complete remission. A revolution in cancer therapy may someday be provided by vector-based gene and drug delivery systems. However, it remains difficult to achieve this aim because viral and non-viral vectors have their own advantages and limitations. To overcome these limitations, virosomes have been constructed by combining viral components with non-viral vectors or by using pseudovirions without viral genome replication. Viruses, such as influenza virus, HVJ (hemagglutinating virus of Japan; Sendai virus) and hepatitis B virus, have been used in the construction of virosomes. The HVJ-derived vector is particularly promising due to its highly efficient delivery of DNA, siRNA, proteins and anti-cancer drugs. Furthermore, the HVJ envelope (HVJ-E) vector has intrinsic anti-tumor activities including the activation of multiple anti-tumor immunities and the induction of cancer-selective apoptosis. HVJ-E is currently being clinically used for the treatment of melanoma. A promising multi-modal cancer therapy will be achieved when virosomes with intrinsic anti-tumor activities are utilized as vectors for the delivery of anti-tumor drugs and genes.

Update on non-viral delivery methods for cancer therapy: possibilities of a drug delivery system with anticancer activities beyond delivery as a new therapeutic tool

IMPORTANCE OF THE FIELD

Cancer is the most formidable human disease. Owing to the heterogeneity of cancer, a single-treatment modality is insufficient for the complete elimination of cancer cells. Therapeutic strategies from various aspects are needed for cancer therapy. These therapeutic agents should be carefully selected to enhance multiple therapeutic pathways. Non-viral delivery methods have been utilized to enhance the tumor-selective delivery of therapeutic molecules, including proteins, synthetic oligonucleotides, small compounds and genes.

AREAS COVERED IN THIS REVIEW

As non-viral delivery methods, liposomes and polymer-based delivery materials to target tumors mainly by systemic delivery, physical methods including electroporation, sonoporation, and so on, to locally inject therapeutic molecules, and virosomes to use the viral infectious machinery for the delivery of therapeutic molecules are summarized.

WHAT THE READER WILL GAIN

This article aims to provide an overview of the characteristic properties of each non-viral vector. It will be beneficial to utilize appropriately the vector for cancer treatment.

TAKE HOME MESSAGE

Efficient and minimally invasive vectors are generally considered to be the ideal drug delivery system (DDS). However, against cancer, DDS equipped with antitumor activities may be a therapeutic choice. By combining therapeutic molecules with DDS having antitumor activities, enhancement of the multiple therapeutic pathways may be achieved.

Anti-tumor effect of 125I-UdR in combination with Egr-1 promoter-based IFNγ gene therapy in vivo

Although (125)I-UdR treatment of malignant tumors in animal models and patients has achieved a certain effect, the short half-life of (125)I-UdR in vivo and its cellular uptake only in S phase of the cell cycle are limiting factors with regard to tumor eradication, and therefore its combination with other applications is a promising strategy in cancer therapy. In this study, we show that (125)I-UdR radionuclide therapy in combination with Egr-1 promoter-based IFNγ gene therapy is more effective than (125)I-UdR therapy alone in suppressing tumor growth and extending survival duration in mice bearing H22 hepatomas. Combined therapy could significantly inhibit cell proliferation and tumor angiogenesis, induce apoptosis and enhance cytotoxic activities of splenic CTL of the mice. Our results suggest that (125)I-UdR in combination with Egr-1 promoter-based IFNγ gene therapy may provide novel approaches for cancer treatment.

Combined effects of radiotherapy and endostatin gene therapy in melanoma tumor model

PEgr-Endostatin-EGFP plasmid was constructed to investigate its expression properties induced by ionizing irradiation and the effect of pEgr-Endostatin-EGFP gene-radiotherapy on melanoma tumor-bearing mice. The pEgr-Endostatin-EGFP plasmid was transfected into B16 cell line with liposome. The expression property of endostatin was investigated by RT-PCR and that of EGFP was detected by flow cytometry. Tumor-bearing mice were treated by the plasmid injection and 2 Gy X-irradiation of three fractions. Tumor growth was observed for 18 days after treatment. Change of tumor capillary formation was measured with histochemistry assay at the end of the experiment. The expression of GFP in B16 melanoma cells was detected after X-irradiation with 0.05-20 Gy. Time-course studies showed that the expression of GFP in B16 cells reached its peak at 8 h after irradiation with 2 Gy. The injection of pEgr-Endostatin-EGFP recombinant plasmid into the implanted B16 melanoma in C57BL/6J mice followed by local X-irradiation could significantly inhibit tumor growth with inhibition of intratumor micro-vessel density. The inhibitory effect of pEgr-Endostatin-EGFP gene-radiotherapy on the growth of B16 melanoma is correlated with the marked decrease of intratumoral vascularization. The present data point to the potential of an anti-angiogenic approach in gene-radiotherapy of cancer.

Gene therapy of liver cancer

The application of gene transfer technologies to the treatment of cancer has led to the development of new experimental approaches like gene directed enzyme/pro-drug therapy (GDEPT), inhibition of oncogenes and restoration of tumor-suppressor genes. In addition, gene therapy has a big impact on other fields like cancer immunotherapy, anti-angiogenic therapy and virotherapy. These strategies are being evaluated for the treatment of primary and metastatic liver cancer and some of them have reached clinical phases. We present a review on the basis and the actual status of gene therapy approaches applied to liver cancer.

Non-viral vectors for cancer therapy

Cancers are diverse and often resistant to therapeutic strategies. Gene therapy has yet to meet the promise of a breakthrough in cancer therapy. There are several barriers to overcome in cancer gene therapy. One of the biggest challenges is the design of appropriate vectors. Numerous viral and non-viral methods for gene transfer have been developed for human gene therapy, but both viral and non-viral vectors have limitations and advantages. In this review article, recent improvements in the development of non-viral vectors for delivering gene therapy for the treatment of cancer will be discussed.