Targeting PD-1 in Squamous Cell Carcinoma: Flavonoid-based Therapeutics Unveiled through in silico and in vitro Approaches.

Introduction: Squamous cell carcinoma is a major public health concern, with traditional treatments such as surgery, chemotherapy, and radiation therapy frequently resulting in significant side effects. Immunotherapy targeting checkpoints such as PD-1, CTLA-4, and B7- H3 provides a more specific approach but incurs high costs due to monoclonal antibodies.

Aim and objective: This study aims to investigate the potential of natural flavonoids as lowtoxicity, small molecule-based alternatives targeting the PD-1 immunological checkpoint for SCC treatment. It aims to identify and evaluate flavonoid compounds from the NPACT database for their efficacy through in silico and in vitro screenings.

Method: Employing a comprehensive in silico approach, including SBVS, Drug Likeness, Toxicity Prediction, Consensus Molecular Docking, DFT, and 300 ns MD simulations, this study screened for flavonoids with high affinity to PD-1. Identified lead molecules were further validated through in-vitro assays, such as NRU, to assess their anticancer activities.

Result: The flavonoid NPACT01407 showed high affinity for PD-1, favorable drug-like properties, low toxicity, and effective stability at the active site, along with an optimal IC50 value, highlighting its potential as an effective immunotherapeutic agent for SCC.

Conclusion: The study highlights the potential of the flavonoid molecule NPACT01407 as a promising candidate for the immunotherapeutic treatment of Squamous cell carcinoma. These findings provide a solid basis for further experimental validation and drug development efforts, suggesting a novel, less toxic, and cost-effective approach to cancer treatment.