Abstract 1125: TNIK induced chemoradiation resistance in small cell lung cancer

Abstract Chemoradiation (CRT) is the standard first-line therapy for limited stage small cell lung cancer (LS-SCLC), which is characterized by early metastasis, intrinsic-acquired CRT resistance and tumor recurrence. CRT confers a 20-25% 5-year overall survival in patients with LS-SCLC. In this study, we utilized patient-derived xenograft (PDX) models to demonstrate CRT resistance of SCLC and identified CRT resistance candidate genes from various SCLC PDX that represent the majority of molecular subtypes (n=4 that include SCLC-A and SCLC-N subtypes). RNA-seq data identified TNIK (Traf2- and Nck-interacting kinase) as one such gene that is consistently upregulated in SCLC PDXs exposed to CRT compared to single modality treatments. Copy number gains of TNIK were also present in human SCLC samples. Overcoming this CRT resistance is crucial in improving treatment outcomes and patient survival. Genetic depletion or pharmacological inhibition of TNIK reduced the in vitro clonogenic survival of TNIKhigh SCLC cells, NCI-H446 and makes them increasingly sensitive to CRT. In vivo, pharmacological inhibition of TNIK with the inhibitor NCB-0846, enhances the CRT sensitivity of NCI-H446 cell line-derived xenografts (CDX) in NOD SCID immunodeficient mice. Furthermore, pharmacological inhibition of TNIK in vivo demonstrated sensitivity to CRT in LX33 PDX. In conclusion, our results indicate that TNIK plays a role in conferring resistance to CRT in vitro in SCLC cell lines and in vivo in SCLC CDX and PDX models and therefore, can be a potential therapeutic target in limited stage SCLC. Citation Format: Dipanwita Dutta Chowdhury, Eddie Imada, Nick Connis, Triet Nguyen, Jinhee Chang, Danielle Council, Audrey Lafargue, Mohammad Rezaee, Phuoc T. Tran, Luigi Marchionni, Christine L. Hann. TNIK induced chemoradiation resistance in small cell lung cancer abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 1125.