Synthesis and evaluation of novel functionalized beta-lactams as potent anti-melanoma agents targeting PI3K/MAPK and JAK/STAT pathways

Background: Skin cancers represent the most prevalent malignancies in the United States, affecting approximately 9,500 individuals daily and contributing to an annual economic burden exceeding $8.1 billion. Cutaneous melanoma skin cancer (CMSC), accounted for more than one million affected individuals and over 7,600 deaths in the US in 2022. Despite advances in targeted interventions, durable responses remain limited by systemic toxicity, low-bioavailability and rapid development of drug resistance. These challenges highlight the critical need for novel molecular scaffolds with improved pharmacological profiles and multi-target mechanisms. Methods: To address this need, we leverage diversity-oriented synthesis, a powerful approach for creating structurally diverse, drug-like scaffolds with enhanced pharmacological potential. This strategy is becoming increasingly relevant in oncology drug discovery pipelines. A focused library of 40 novel, functionalized beta-lactams were synthesized and screened against human (A375, SK-MEL-28) and murine (B16F10) CMSC cell lines. Cytotoxicity was assessed via IC₅₀ determination, followed by phenotypic and mechanistic assays evaluating clonogenicity, migration, redox modulation, and apoptosis. Results: Several derivatives demonstrated potent anti-melanoma activity, from which two lead molecules, W035 and W038, were selected for detailed characterization. W035 showed IC₅₀ values of 14 μM (B16F10) and 24 μM in A375 cells, while W038 exhibited IC₅₀ values of 24 μM in both A375 and B16F10 cells. Both compounds significantly inhibited colony formation (60% reduction at 0.75×IC₅₀) and suppressed wound closure and migration by 80%, indicating strong anti-metastatic potential. Mechanistically, W035 and W038 disrupted redox homeostasis, evidenced by 50% reduction in intracellular reactive oxygen species, and robustly activated caspase-3/7, confirming induction of apoptotic cell death. ADME profiling using SwissADME web-tool, predicted favorable drug-likeness, including high skin permeation (log Kp), good gastrointestinal absorption, Lipinski rule compliance, optimal lipophilicity (Log P_o/w<5), and favorable biodegradability. SwissTargetPrediction analysis indicated that the lead compounds possess a multi-target melanoma-inhibitory profile involving targeting MAPK, PI3Ks and JAK/STAT signaling pathways. Immunoblotting further therapy dose-dependent downregulation of these targets, indicating convergence on key melanoma signaling nodes. Conclusions: This study identifies rationally designed beta-lactam-based scaffolds with multi-target anti-melanoma activity. The lead compounds modulate apoptotic signaling, redox homeostasis, and MAPK/PI3K and JAK/STAT pathways, supporting rationale their further optimization and preclinical development for melanoma therapy.