TH301, a Circadian Clock Modulator, Emerges as a Novel Anti-oncogenic Agent for Human Pancreatic Cancer Cells: the Dispensable Roles of p53, CRY2 and BMAL1 in TH301-induced CDKN1A/p21CIP1/WAF1 Upregulation

Background: Pancreatic Ductal Adeno-Carcinoma (PDAC) is a highly aggressive cancer, with lim-ited treatment options. Disruption of the circadian clock, which regulates key cellular processes, has been implicated in PDAC initiation and progression. Hence, targeting circadian clock components may offer new therapeutic opportunities for the disease. This study investigates the cytopathic ef-fects of TH301, a novel CRY2 stabilizer, on PDAC cells, aiming to evaluate its potential as a novel therapeutic agent. Methods: PDAC cell lines (AsPC-1, BxPC-3 and PANC-1) were treated with TH301, and cell viability, cell cycle progression, apoptosis, autophagy, circadian gene and protein expression profiles were analyzed, using MTT assay, flow cytometry, Western blotting and RT-qPCR technologies. Results: TH301 proved to significantly decrease cell viability and to induce cell cycle arrest at the G1-phase across all PDAC cell lines, and especially the AsPC-1 and BxPC-3 ones, herein examined. It caused dose-dependent apoptosis and autophagy, and it synergized with Chloroquine and Oxaliplatin to enhance anti-oncogenicity. The remarkable induction of p21 by TH301 was shown to follow clock- and p53-independent patterns, thereby indicating the critical engagement of alternative mechanisms. Conclusions: TH301 demonstrates significant anti-cancer activities in PDAC cells, thus serving as a promising, new therapeutic agent, which can also syn-ergize with approved treatment schemes, by targeting pathways beyond circadian clock regulation. Altogether, TH301 likely opens new therapeutic windows for the successful management of pan-creatic cancer, in the clinical practice.