Preclinical Study of Novel Gene Silencer Pyrrole-Imidazole Polyamide Targeting Human TGF-β1 Promoter for Hypertrophic Scars in a Common Marmoset Primate Model

Abstract

We report a preclinical study of a pyrrole-imidazole (PI) polyamide that targets the human transforming growth factor (hTGF)-β1 gene as a novel transcriptional gene silencer in a common marmoset primate model. We designed and then synthesized PI polyamides to target the hTGF-β1 promoter. We examined effects of seven PI polyamides (GB1101-1107) on the expression of hTGF-β1 mRNA stimulated with phorbol 12-myristate 13-acetate (PMA) in human vascular smooth muscle cells. GB1101, GB1105 and GB1106 significantly inhibited hTGF-β1 mRNA expression. We examined GB1101 as a PI polyamide to hTGF-β1 for hypertrophic scars in marmosets in vivo. Injection of GB1101 completely inhibited hypertrophic scar formation at 35 days post-incision and inhibited cellular infiltration, TGF-β1 and vimentin staining, and epidermal thickness. Mismatch polyamide did not affect hypertrophic scarring or histological changes. Epidermis was significantly thinner with GB1101 than with water and mismatch PI polyamides. We developed the PI polyamides for practical ointment medicines for the treatment of hypertrophic scars. FITC-labeled GB1101 with solbase most efficiently distributed in the nuclei of epidermal keratinocytes, completely suppressed hypertropic scarring at 42 days after incision, and considerably inhibited epidermal thickness and vimentin-positive fibroblasts. PI polyamides targeting hTGF-β1 promoter with solbase ointment will be practical medicines for treating hypertrophic scars after surgical operations and skin burns.

Targeting TGF-β Signaling for Therapeutic Gain

“…2; Table 1), including a pyrrole-imidazole polyamide drug that blocks transcription of the TGFB1 target gene (Yao et al 2009;Chen et al 2010;Matsuda et al 2011;Washio et al 2011;Igarashi et al 2015), antisense RNAs that target TGFB1 or TGFB2 mRNAs for degradation (Hau et al 2009;Vallieres 2009;Schlingensiepen et al 2011), antibodies against TGF-b ligands or receptors that block ligand -receptor engagement, and many small molecule ATP-mimetic TbRI kinase inhibitors (Fig. 2).…”

The influence of GSTT/GSTM null genotypes in scarring

“…Pinpointing the mutations which predispose a patient to develop pathological scars offers the possibility of pre-operative planning and primary prophylaxis, thus sparing the need for reintervention or costly and timeconsuming treatments ahead. Furthermore, understanding the molecular basis of scarring is the first step in creating molecular treatment options for keloid scars, as seen with TGF-1 promoter silencing therapy [11].…”

Crosstalk of the Androgen Receptor with Transcriptional Collaborators: Potential Therapeutic Targets for Castration-Resistant Prostate Cancer

“…Matsuda et al showed that PI polyamides accumulated in nuclei of kidney cells in rats and were maintained for about two weeks without any drug delivery system [135,136]. Recently, Igarashi et al [137] studied the possible clinical applications of PI polyamides using a primate model. They developed an ointment including a PI polyamide targeting human transforming growth factor beta (TGF-β) 1 and tested for hypertrophic scars in marmosets.…”

“…They developed an ointment including a PI polyamide targeting human transforming growth factor beta (TGF-β) 1 and tested for hypertrophic scars in marmosets. The PI polyamide bound to keratinocyte nuclei in marmosets and suppressed hypertrophic scarring without any side effects [137]. These reports are fundamental evidence for the clinical application of PI polyamides and increasing interest in their use for AR and some AR collaborative TFs, such as OCT1 and ETS family genes.…”