TRIB2作为ALK重排非小细胞肺癌的治疗脆弱性靶点

Background: Lung cancer remains the leading cause of cancer-related deaths worldwide. Among its molecularly defined subsets, EML4-ALK rearranged non-small cell lung cancer (NSCLC) is a distinct subtype (3-5% of NSCLC), occurring disproportionately in younger, non-smoking patients. Despite the clinical success of next-generation ALK tyrosine kinase inhibitors (TKIs), including alectinib and lorlatinib, most patients eventually experience disease relapse due to adaptive signaling and bypass mechanisms. The prognosis of relapsed ALK-positive NSCLC is poor, underscoring the critical need to identify novel therapeutic targets that drive tumor growth and survival. We have previously demonstrated that TRIB2, a pseudokinase, promotes tumor growth and therapy resistance in tumors treated with targeted therapy. We therefore evaluated TRIB2 expression in ALK-rearranged lung cancer cell lines and assessed the effects of TRIB2 downregulation on tumor cell growth and viability. Methods: TRIB2 expression was assessed, and its functional role was tested using shRNA and CRISPR-Cas9-mediated depletion, and pharmacologic inhibition approaches. Cell viability, apoptosis, and downstream signaling changes were analyzed in vitro, while xenograft studies evaluated tumor growth in vivo . Synergy studies were performed combining TRIB2 inhibition with ALK inhibitors. Results: TRIB2 was found to be highly expressed in ALK-positive cell lines and lung tumors. Genetic inhibition of TRIB2 using shRNA significantly suppressed proliferation and induced apoptosis in ALK-positive NSCLC cells. In vivo , Dox-induced CRISPR-Cas9-mediated depletion of TRIB2 resulted in significant tumor regression in xenograft models, highlighting its critical role in tumor maintenance. Combination studies revealed that TRIB2 inhibition synergized with ALK-TKIs such as alectinib or lorlatinib to more effectively suppress cancer cell growth than either approach alone. Mechanistic studies demonstrated that TRIB2 loss attenuated ALK signaling, reducing phosphorylation of key survival effectors including STAT3, thereby impairing downstream pathways essential for cell survival and tumor progression. Conclusions: This study identifies TRIB2 as a critical survival factor in ALK-rearranged NSCLC and establishes its inhibition as a promising therapeutic strategy. TRIB2 targeting not only disrupts tumor maintenance but also enhances sensitivity to ALK TKIs, offering a potential approach to extend the durability of therapeutic responses. These findings provide strong translational rationale for developing TRIB2-targeted therapies to improve outcomes for patients with ALK-positive lung cancer.