Delivery of the gene encoding the tumor suppressor Sef into prostate tumors by therapeutic-ultrasound inhibits both tumor angiogenesis and growth

Abstract

Carcinomas constitute over 80% of all human cancer types with no effective therapy for metastatic disease. Here, we demonstrate, for the first time, the efficacy of therapeutic-ultrasound (TUS) to deliver a human tumor suppressor gene, hSef-b, to prostate tumors in vivo. Sef is downregulated in various human carcinomas, in a manner correlating with tumor aggressiveness. In vitro, hSef-b inhibited proliferation of TRAMP C2 cells and attenuated activation of ERK/MAPK and the master transcription factor NF-κB in response to FGF and IL-1/TNF, respectively. In vivo, transfection efficiency of a plasmid co-expressing hSef-b/eGFP into TRAMP C2 tumors was 14.7 ± 2.5% following a single TUS application. Repeated TUS treatments with hSef-b plasmid, significantly suppressed prostate tumor growth (60%) through inhibition of cell proliferation (60%), and reduction in blood vessel density (56%). In accordance, repeated TUS-treatments with hSef-b significantly inhibited in vivo expression of FGF2 and MMP-9. FGF2 is a known mitogen, and both FGF2/MMP-9 are proangiogenic factors. Taken together our results strongly suggest that hSef-b acts in a cell autonomous as well as non-cell autonomous manner. Moreover, the study demonstrates the efficacy of non-viral TUS-based hSef-b gene delivery approach for the treatment of prostate cancer tumors, and possibly other carcinomas where Sef is downregulated.

In vivo gene delivery mediated by non-viral vectors for cancer therapy

“…Since there are several therapeutic ultra sound waves for clinical applications, those which operates at frequencies of 1-3 MHz and use relatively low intensities (0.1-2 W/cm 2 ) could be considered for in vivo transfection. Using such therapeutic-ultrasound (TUS), a human tumor suppressor gene, hSef-b, was successfully transferred to prostate tumors in vivo [141]. These achievements have shown the potential of these routes for further studies towards the clinical translation.…”

Interleukin-17 receptor D (Sef) is a multi-functional regulator of cell signaling

“…Therefore, IL17RD indirectly suppresses the ubiquitination of TRAF6 to inhibit the activation of the canonical NF-κB and non-canonical IRF3 pathways and expression of target genes. With respect to signaling downstream of IL1 ligands from the TIR family, IL17RD regulates activation of the NF-κB pathway downstream of IL1α binding to IL1R, by associating with the IKKβ, IKBα and p50 subunits at the Golgi and restricting pathway activation intracellular domain which is common to both isoforms [43]. Thus, SEF (IL17RD) was defined to have a unique role as a scaffolding protein for components of the canonical NF-κB pathway [18].…”

“…IL17RD was also demonstrated to bind with other components of the NF-κB pathway, including Inhibitory Subunit of NF Kappa B Alpha (IκBα) and IκB kinase (IKKβ), partially through the SEFIR domain and via residues 321–395 respectively [ 18 ]. Accordingly, the hSEF-b isoform has been shown to repress activation of the NF-κB pathway, probably by binding to the NF-κB subunits through the intracellular domain which is common to both isoforms [ 43 ]. Thus, SEF (IL17RD) was defined to have a unique role as a scaffolding protein for components of the canonical NF-κB pathway [ 18 ].…”

“…The hSEF-b isoform was shown to suppress the angiogenic response in prostate cancer cells, suggesting a multimodal function for SEF as a tumor suppressor gene. [ 43 ]. Furthermore, mutations in IL17RD have also been associated with certain non-epithelial cancers, such as medullary thyroid carcinoma (MTC) [ 53 ] and follicular dendritic cell sarcoma (FDCS) [ 54 ] (see Table 1 ), in combination with perturbations in other RTK family members.…”

Recent Advances about Local Gene Delivery by Ultrasound

“…efficiency than conventional nontargeted microbubbles [62]. Mishel et al used ultrasound to mediate hSef-b delivery, another kind of human tumor suppressor gene, and demonstrated the efficacy of gene therapy mediated by ultrasound [63]. Recently, gene delivery by ultrasound was also applied in gene-directed enzyme prodrug therapy (GDEPT).…”