Discovery of a potent, orally available tricyclic derivative as a novel BRD4 inhibitor for melanoma.

The epigenetic regulation of the protein bromodomain-containing protein 4 (BRD4) has emerged as a compelling target for cancer treatment. In this study, we outline the discovery of a novel BRD4 inhibitor for melanoma therapy. Our initial finding was that benzimidazole derivative 1, sourced from our library, was a powerful BRD4 inhibitor. However, it exhibited a poor pharmacokinetic (PK) profile. To address this, we conducted a scaffold-hopping procedure with derivative 1, which resulted in the creation of benzimidazolinone derivative 5. This new derivative displayed an improved PK profile. To further enhance the BRD4 inhibitory activity, we attempted to introduce hydrogen bond acceptors. This indeed improved the activity, but at the cost of decreased membrane permeability. Our search for a potent inhibitor with desirable permeability led to the development of tricyclic 18. This compound demonstrated powerful inhibitory activity and a favorable PK profile. More significantly, tricyclic 18 showed antitumor efficacy in a mouse melanoma xenograft model, suggesting that it holds potential as a therapeutic agent for melanoma treatment.

The Reservoir of Persistent Human Papillomavirus Infection; Strategies for Elimination Using Anti-Viral Therapies.

Human Papillomaviruses have co-evolved with their human host, with each of the over 200 known HPV types infecting distinct epithelial niches to cause diverse disease pathologies. Despite the success of prophylactic vaccines in preventing high-risk HPV infection, the development of HPV anti-viral therapies has been hampered by the lack of enzymatic viral functions, and by difficulties in translating the results of in vitro experiments into clinically useful treatment regimes. In this review, we discuss recent advances in anti-HPV drug development, and highlight the importance of understanding persistent HPV infections for future anti-viral design. In the infected epithelial basal layer, HPV genomes are maintained at a very low copy number, with only limited viral gene expression; factors which allow them to hide from the host immune system. However, HPV gene expression confers an elevated proliferative potential, a delayed commitment to differentiation, and preferential persistence of the infected cell in the epithelial basal layer, when compared to their uninfected neighbours. To a large extent, this is driven by the viral E6 protein, which functions in the HPV life cycle as a modulator of epithelial homeostasis. By targeting HPV gene products involved in the maintenance of the viral reservoir, there appears to be new opportunities for the control or elimination of chronic HPV infections.

Phthalate ester-induced thymic stromal lymphopoietin mediates allergic dermatitis in mice.

Recently air pollutants and irritants have been labelled as possible exogenous risk factors for allergic disorders. Although the underlying causes of allergic disorders such as atopic dermatitis and asthma remain unclear, the T helper type 2 (Th2) cell-mediated allergic inflammatory cascade may contribute to their pathogenesis. In the last decade, it has been documented that one of the candidates for triggering Th2 commitment is thymic stromal lymphopoietin (TSLP), the expression of which is up-regulated in the lesions of allergic patients. Here, we describe TSLP function in a fluorescein isothiocyanate (FITC) -induced contact hypersensitivity (CHS) model. A cytokine profile indicated that the model was dominantly mediated by the Th2 milieu. Interestingly, TSLP was increased in the skin during the sensitization phase when stimulated by a solvent, dibutyl phthalate (DBP), but not by FITC hapten or another solvent, acetone. Ear swelling in FITC-induced CHS was totally abrogated by removing DBP from the sensitization or elicitation phase, and was restored by complementary injection of TSLP. Inversely, the ear swelling was suppressed by injection of small interfering RNA against TSLP during the sensitization phase, which was concomitant with decreasing expression of interleukin-4 at the swollen skin site. Taken together, DBP-induced TSLP during the sensitization phase plays a role in establishing FITC-induced CHS and may be one of the causes of Th2 commitment in the model, suggesting that certain environmental toxins, such as DBP, may endow pro-allergic and atopic predisposition in humans or animals.