Endothelin-A receptor in gastric cancer and enhanced antitumor activity of trastuzumab in combination with the endothelin-A receptor antagonist ZD4054

An Update of G-Protein-Coupled Receptor Signaling and Its Deregulation in Gastric Carcinogenesis

G-protein-coupled receptors (GPCRs) belong to a cell surface receptor superfamily responding to a wide range of external signals. The binding of extracellular ligands to GPCRs activates a heterotrimeric G protein and triggers the production of numerous secondary messengers, which transduce the extracellular signals into cellular responses. GPCR signaling is crucial and imperative for maintaining normal tissue homeostasis. High-throughput sequencing analyses revealed the occurrence of the genetic aberrations of GPCRs and G proteins in multiple malignancies. The altered GPCRs/G proteins serve as valuable biomarkers for early diagnosis, prognostic prediction, and pharmacological targets. Furthermore, the dysregulation of GPCR signaling contributes to tumor initiation and development. In this review, we have summarized the research progress of GPCRs and highlighted their mechanisms in gastric cancer (GC). The aberrant activation of GPCRs promotes GC cell proliferation and metastasis, remodels the tumor microenvironment, and boosts immune escape. Through deep investigation, novel therapeutic strategies for targeting GPCR activation have been developed, and the final aim is to eliminate GPCR-driven gastric carcinogenesis.

Design, synthesis and in vitro antiproliferative activity of new thiazolidinedione-1,3,4-oxadiazole hybrids as thymidylate synthase inhibitors

Thymidylate synthase (TS) has been an attention-grabbing area of research for the treatment of cancers due to their role in DNA biosynthesis. In the present study, we have synthesised a library of thiazolidinedione-1,3,4-oxadiazole hybrids as TS inhibitors. All the synthesised hybrids followed Lipinski and Veber rules which indicated good drug likeness properties upon oral administration. Among the synthesised hybrids, compound 9 and 10 displayed 4.5 and 4.4 folds activity of 5-Fluorouracil, respectively against MCF-7 cell line whereas 3.1 and 2.5 folds cytotoxicity against HCT-116 cell line. Furthermore, compound 9 and 10 also inhibited TS enzyme with IC50 = 1.67 and 2.21 µM, respectively. Finally, the docking studies of 9 and 10 were found to be consistent with in vitro TS results. From these studies, compound 9 and 10 has the potential to be developed as TS inhibitors.

Synthesis of New 1, 3, 4-Oxadiazole-Incorporated 1, 2, 3-Triazole Moieties as Potential Anticancer Agents Targeting Thymidylate Synthase and Their Docking Studies

Thymidylate synthase (TS) has emerged as a hot spot in cancer treatment, as it is directly involved in DNA synthesis. In the present article, nine hybrids containing 1,2,3-triazole and 1,3,4-oxadiazole moieties (6–14) were synthesized and evaluated for anticancer and in vitro thymidylate synthase activities. According to in silico pharmacokinetic studies, the synthesized hybrids exhibited good drug likeness properties and bioavailability. The cytotoxicity results indicated that compounds 12 and 13 exhibited remarkable inhibition on the tested Michigan Cancer Foundation (MCF-7) and Human colorectal Carcinoma (HCT-116) cell lines. Compound 12 showed four-fold inhibition to a standard drug, 5-fluoruracil, and comparable inhibition to tamoxifen, whereas compound 13 exerted five-fold activity of tamoxifen and 24-fold activity of 5-fluorouracil for MCF-7 cells. Compounds 12 and 13 inhibited thymidylate synthase enzyme, with an half maximal inhibitory concentration, IC₅₀ of 2.52 µM and 4.38 µM, while a standard drug, pemetrexed, showed IC₅₀ = 6.75 µM. The molecular docking data of compounds 12 and 13 were found to be in support of biological activities data. In conclusion, hybrids (12 and 13) may inhibit thymidylate synthase enzyme, which could play a significant role as a chemotherapeutic agent.