Novel senolytic and senescence-suppressing compounds overcome senescence-driven chemoresistance in NSCLC

Background Non-small cell lung cancer (NSCLC) is characterized by a high recurrence rate after curative resection of early-stage disease and a poor overall survival. Although targeted therapy and immunotherapy have reshaped the standard-of-care (SOC) of NSCLC, chemotherapy, particularly platinum-doublet regimens, remains a key treatment modality in early-stage, locally advanced and metastatic settings. However, in advanced NSCLC, response rates to platinum-based regimens remain low (15 - 30%) and have reached a plateau in treatment efficacy, underscoring the need for novel therapeutic strategies. Emerging evidence highlights the clinical relevance of cellular senescence in cancer, including NSCLC. Therapy-induced senescence (TIS) is increasingly recognized as a critical determinant of treatment outcome, therapy resistance and disease recurrence. Targeting senescence therefore represents a promising and rapidly evolving area in cancer research. Methods Using our in-house developed high-throughput senescence labeling and classification strategy, we aimed to evaluate TIS induction by multiple SOC NSCLC chemotherapeutic agents. After unraveling the most potent conditions for TIS, we ought to dive further in the TIS phenotype using transcriptomic analysis. Potential senotherapeutic strategies were then identified using transcriptomic drug connectivity analysis. Drug responses of control and TIS conditions to potential novel senolytics were examined by live-cell imaging at the UAntwerp DrugVision.AI screening platform on a Tecan Spark® Cyto. Afterwards, suppression of the TIS phenotype was determined using IHC of canonical senescence markers, being the presence of SA-β-Gal, p21 and p53, and the absence of proliferation marker KI-67. Results Our labeling strategy identified Platinum-based chemotherapeutics, mainly Cisplatin, as the most potent TIS inducers. We subsequently demonstrated selective senolytic activity of the established Bcl-2 inhibitors Venetoclax and Navitoclax, the BAX activator BTSA1 and the thioredoxin reductase inhibitor Auranofin. In addition, potent suppression of TIS was observed with Amiloride, an epithelial sodium channel blocker, and NECA, a non-selective adenosine receptor agonist. Importantly, senescence suppression modulated treatment response, resulting in a significantly increased sensitivity to Venetoclax and Auranofin. Moreover, the expression of the targets of our novel senotherapeutic targets was confirmed on protein level both in cell lines and in neo-adjuvant treated NSCLC patient samples. Conclusions In conclusion, we identified multiple promising and clinically translatable senescence-directed strategies, predominantly involving repurposable agents with well-established safety profiles (i.e., Venetoclax, Auranofin and Amiloride). As such, these drugs could be repurposed either as chemosensitizers to enhance current SOC chemotherapy or as adjuvant senolytic therapy, to overcome TIS-associated therapy resistance and disease recurrence, thereby improving outcome and survival for NSCLC patients.