A histone deacetylase inhibitor enhances expression of genes inhibiting Wnt pathway and augments activity of DNA demethylation reagent against nonsmall-cell lung cancer

Abstract

Development of new inhibitors targeting histone deacetylases (HDACs) with improved efficacy for solid tumor therapy is urgently needed. Here, we report the development of a novel HDAC inhibitor TMU-35435 and verify it as a single agent and in combination treatment with DNA demethylation reagent 5-aza-2'-deoxycytidine (5-aza-dC) in lung cancer preclinical models. TMU-35435 exerted cancer-specific cytotoxicity via mitochondria-mediated apoptosis. Expression microarrays revealed a unique TMU-35435-induced gene networks enriched in biological processes, including "negative regulation of cell proliferation" and "Wnt receptor signaling pathway" compared to FDA-approved HDAC inhibitor SAHA. TMU-35435 inhibited tumor growth with good pharmacokinetic properties and safety features in lung orthotopic and subcutaneously implanted xenograft models. TMU-35435 and 5-aza-dC showed synergistic antitumor effects through reactivation of tumor suppressor genes and those genes encoding negative regulators of Wnt signaling pathway in vitro and in vivo. Some genes showed additive inhibition of DNA methylation upon TMU-35435 and 5-aza-dC combined treatment. Our findings suggested that TMU-35435 is a potential HDAC inhibitor for lung cancer treatment as a single agent and in combination with 5-aza-dC.

Mechanism of Action for HDAC Inhibitors—Insights from Omics Approaches

“…In lung cancer cells that were treated with a novel HDAC inhibitor TMU-35435, microarray analysis identified cell proliferation and the Wnt signaling pathway as enriched biological processes [52]. In H460 human lung carcinoma cells that were treated with butyrate, microarray analysis revealed 32 genes with greater than two-fold increase and 66 genes less than one-third expression level as compared with the untreated cells.…”

Epigenetic events involved in organic cation transporter 1‐dependent impaired response of hepatocellular carcinoma to sorafenib

“…The results showed significant stimulation of hOCT1 expression ( Figure 5B). Because it has been reported that the effect of DAC can be enhanced by histone deacetylase inhibitors (Shieh et al, 2017), HepG2 and HuH7 cells were exposed to 5 mM sodium butyrate, a previously evaluated non-toxic concentration (data not shown), for 24 h, and the hOCT1 expression was measured. Although sodium butyrate alone stimulated hOCT1 expression, the combination with DAC did not further increase hOCT1 expression (data not shown).…”

The role of developmental signaling pathways in non-small cell lung carcinoma

“…TMU-35435 which functions as a histone deacetylase (HDAC) inhibitor successfully induced G 2 /M stage arrest of four different NSCLC cell lines while leaving non-cancerous lung cells intact. Its mode of action was through upregulation of several genes encoding for Wnt inhibitors, possibly by catalyzing the presence of activating acety-lation histone marks [111]. The antitumor effects of norcantharidin consisted of decreased methylation of WIF-1 gene promoters and increased expression of SFRP1.…”