Accelerating PROTACs Discovery Through a Direct-to-Biology Platform Enabled by Modular Photoclick Chemistry.

Proteolysis targeting chimeras (PROTACs) have emerged as a promising strategy for drug discovery and exploring protein functions, offering a revolutionary therapeutic modality. Currently, the predominant approach to PROTACs discovery mainly relies on an empirical design-synthesis-evaluation process involving numerous cycles of labor-intensive synthesis-purification and bioassay data collection. Therefore, the development of innovative methods to expedite PROTAC synthesis and exploration of chemical space remains highly desired. Here, a direct-to-biology strategy is reported to streamline the synthesis of PROTAC libraries on plates, enabling the seamless transfer of reaction products to cell-based bioassays without the need for additional purification. By integrating amide coupling and light-induced primary amines and o-nitrobenzyl alcohols cyclization (PANAC) photoclick chemistry into a plate-based synthetic process, this strategy produces PROTAC libraries with high efficiency and structural diversity. Moreover, by employing this platform for PROTACs screening, we smoothly found potent PROTACs effectively inhibit triple-negative breast cancer (TNBC) cell growth and induce rapid, selective targeted degradation of cyclin-dependent kinase 9 (CDK9). The study introduces a versatile platform for assembling PROTACs on plates, followed by direct biological evaluation. This approach provides a promising opportunity for high-throughput synthesis of PROTAC libraries, thereby enhancing the efficiency of exploring chemical space and accelerating the discovery of PROTACs.

Chemoprevention of metaplasia initiation and carcinogenic progression to esophageal adenocarcinoma by resveratrol supplementation.

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a polyphenol found in the skin of the grape and red wine, has been found to have chemopreventitive effects in some carcinogenic models. The effects of resveratrol on the initiation of Barrett's metaplasia and the carcinogenic progression to esophageal adenocarcinoma have not been evaluated. The aim of this study was to evaluate the effects of resveratrol on the transition from reflux esophagitis to Barrett's metaplasia to dysplasia to esophageal adenocarcinoma in an established rat model. Male Sprague-Dawley rats underwent esophagoduodenal anastomosis as per institutional approved protocol. They were then treated twice weekly with intraperitoneal injection of 7 mg/kg of resveratrol or saline. Additional nonoperated rats served as controls. The rats in each group were assigned to 1, 3, or 5-month subgroups. The distal esophagus was preserved for blinded histopathological examination at the time of harvest. Thirty-one animals in the 5-month resveratrol group showed a decreased severity of esophagitis (P<0.0001), incidence of intestinal metaplasia (P = 0.3567), and incidence of carcinoma (P = 0.4590) as compared with both the saline and nonoperated control groups. In conclusion, morphological characteristics consistent with decreased esophagitis and incidences of metaplasia and esophageal adenocarcinoma were seen on histopathology in the resveratrol group. Resveratrol resulted in a small diminution of the carcinogenic effects and progression to metaplasia, and further human studies are designed to explore the potential anticarcinogenic mechanism.