Intramuscular electroporation delivery of IL-12 gene for treatment of squamous cell carcinoma located at distant site

Abstract

Gene therapy with IL -12 has been shown to elicit potent systemic antitumor response in a variety of tumors. Although direct intratumoral injection is the most commonly used delivery route for gene therapy of solid tumors, the skeletal muscle has been shown to be an ideal tissue for gene delivery to produce systemic gene expression. We have previously demonstrated that electroporation delivery of a reporter gene to muscle enhances the transfection efficiency and the level of gene expression by two to three logs. We report here that intramuscular ( i.m. ) injection of as little as 10 g of the IL -12 DNA plasmid followed by electroporation prevents squamous cell carcinoma ( SCCVII ) tumor establishment in up to 40% of experimental animals and reduces the volume of established tumors by 75% compared to controls ( P < .05 ) . By comparison, there was no difference in tumor growth observed between IL -12 injection alone and injection of empty vector with or without electroporation. The induction of antitumor activity by i.m. electroporation delivery of the IL -12 gene is associated with an increase in IL -12 expression in muscle and serum. The level of IL -12 expression in muscle and serum was 1500 pg / tibialias muscle and 170 pg / mL serum, respectively, at day 6, after the gene was delivered by electroporation. In contrast, the level of IL -12 when the gene was injected without electroporation was hardly detectable after subtracting the background level of IL -12 detected in naõ Ève mice. The high level of IL -12 expression led to a 170 -fold induction of IFN -expression in serum at day 6 after i.m. electroporation delivery of IL -12 DNA plasmid, which was equal to 1450 pg / mL in the serum. The induction of antitumor activity by i.m. electroporation delivery of the IL -12 gene also correlates with increased CD8 + T -cell population in peripheral blood but not in spleen. Our findings suggest that i.m. delivery of IL -12 gene using electroporation is an effective method of inducing a systemic antitumor response against SCC. Cancer Gene Therapy ( 2001 ) 8, 151 ± 157

Electrotransfer of gene encoding endostatin into normal and neoplastic mouse tissues: Inhibition of primary tumor growth and metastatic spread

“…19 The efficiency of gene transfer by electroporation is greater by several orders of magnitude than that of passive DNA transfer (see Fig 1). Electrotransfer of the endostatin gene into normal tissues ( muscle ) could also be achieved (Fig 4) and several previous studies have indicated that electrotransfer into muscle of other therapeutic genes such as those encoding interleukin -12 (e.g., Hanna et al 34 ) and erythropoietin ( e.g., Rizzuto et al 35 ) or FGF 1 ( e.g., Mir et al 36 ) is very effective. Transfer of the endostatin gene into muscles resulted in augmented levels of circulating endostatin ( Fig 4) and diminished the number of metastatic foci in mouse lungs ( Fig 5) ( see also Blezinger et al 17 ).…”

Local and systemic antitumor effect of intratumoral and peritumoral IL-12 electrogene therapy on murine sarcoma

“…[25][26][27]43,44 Systemic effects on distant tumors include inhibition of tumor growth, antimetastatic effect and induction of long-term systemic immunity to regrowth of new nodules. However, the direct antitumor effect on established tumors after intramuscular EGT delivery is generally less pronounced, compared to intratumoral therapeutic gene application.…”

Long-lasting gene expression by particle-mediated intramuscular transfection modified with bupivacaine: combinatorial gene therapy with IL-12 and IL-18 cDNA against rat sarcoma at a distant site

“…Although the muscle injection of expression plasmids leads to only low levels of gene expression, a few successful studies of gene expression against mouse tumor models using an intramuscular electroporation delivery of cytokine cDNAs (for example, IFN-g and IL-12) have recently been reported. 50,51 In those studies, however, only cytokine expression and tumor inhibition have been evaluated. In the present study, we demonstrated the expression efficiency and duration of luciferase and GFP genes in regenerating muscle using the particle-mediated transfer method, although we could not compare the efficacy between intramuscular electroporation and the gene-gun method.…”