Biological drivers of non-small cell lung cancer (NSCLC) in black patients remain underexplored, with only a small number of studies on race-related differences in actionable mutations and aggregate gene expression. As a result, these efforts have likely missed other important drivers of race-related NSCLC biological and clinical heterogeneity. The proposed work addresses the urgent need to functionally characterize and modulate novel race-related RNA splicing targets in NSCLC for potential therapeutic application. We are the first team to identify alternative RNA splicing differences in NSCLC between patients of African and European ancestry. Specifically, in lung squamous cell carcinomas (LUSCs), the number of race- related differentially spliced genes (DSGs) (4,830) far exceeded the number of genes exhibiting race-related differential aggregate gene expression (DEGs) (267) in the same tissues. Among the DSGs, 17% are reported to be oncogenes, tumor suppressor genes and/or drivers and 355 RNA splicing events within DSGs are associated with LUSC survival. Among the DEGs, 6% are reported to be cancer-related and 18 are associated with LUSC survival. A number of the DSGs and DEGs involve therapeutically targetable signaling pathways. Furthermore, we have mined The Cancer Genome Atlas (TCGA) and have identified DSGs and DEGs in additional LUSCs or lung adenocarcinomas (LUADs).
The aims of the proposed work are to extend this novel area of inquiry with significance for precision oncology in NSCLC by 1) assessing the expression of RNA splice variants and genes encoding trans-acting splicing factors across clinically relevant NSCLC subgroups in patients of African and European ancestry, 2) interrogating the functional significance of prioritized race-related RNA splice variants for the biology of NSCLC, and 3) developing novel splice-switching oligonucleotide (SSO) morpholino drugs to modulate RNA splicing events critical to race-related NSCLC for potential therapeutic application. The rationale for and impact of this study is that it will 1) increase understanding of the molecular mechanisms underlying lung cancer disparities, 2) provide an abundance of novel RNA splicing-related targets for development of new biomarkers and therapeutic agents for NSCLC in patients of African ancestry, 3) when combined with TCGA data, this study will more than double the number of molecularly characterized NSCLC biospecimens from patients of African ancestry, making such data available to the nationwide cohort of scientists conducting research on lung cancer and lung cancer disparities, and 4) position novel RNA splicing-targeted drugs for NSCLC in patients of African ancestry for in vivo studies. Ultimately, such precision oncology interventions and further studies enabled by the molecularly characterized cohort of biospecimens will have the potential to mitigate NSCLC disparities.
African Americans suffer disproportionately from lung cancer; they have the highest number of new cases and deaths from lung cancer and receive diagnoses at a younger age than patients of other races and ethnicities do. Our proposed work focuses on understanding the biological differences between lung cancer from African American and white patients and developing new tools to modulate these differences to treat aggressive lung cancer. Ultimately, these findings will reduce the disproportionate burden from lung cancer among African Americans and improve clinical outcomes for patients of all races and ethnicities with aggressive lung cancer.
