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P1.04 - Immunooncology (Not CME Accredited Session) (ID 936)
- Event: WCLC 2018
- Type: Poster Viewing in the Exhibit Hall
- Presentations: 1
- Coordinates: 9/24/2018, 16:45 - 18:00, Exhibit Hall
P1.04-01 - Impact of Chromatin Remodeling Genes Including SMARCA2 and PBRM1 on Neoantigen and Immune Landscape of NSCLC (ID 12593)
16:45 - 18:00 | Author(s): Lihua Zou
Epigenetic changes in tumors and their microenvironment immune cells have been the recent focus of cancer research. Aberrations in SWI/SNF complexes within the chromatin remodeling machine may play a major role in carcinogenesis. However, little is known about their impact on neoantigen and the immune landscape of NSCLC.a9ded1e5ce5d75814730bb4caaf49419 Method
Patients were divided into two groups; Mut group (at least one mutation in 27 SWI/SNF complex subunit genes including SMARCA2 and PBRM1) and NoMut group (no SWI/SNF mutations). We analyzed genomic, transcriptomic data from the TCGA database including patients with adenocarcinoma (ADC, n=515) and squamous cell carcinoma (SQCC, n=501) of lung cancer. The tumor immune landscape was analyzed using the signatures derived from 812 ‘immune metagenes’ (Angelova, M. et al, 2015). We analyzed neoantigen burden and immune landscape between two groups. RNA expression of the above genes were compared. Patients were also divided by the expression levels of the above genes (1st quartile vs 4th quartile).4c3880bb027f159e801041b1021e88e8 Result
Mut group (142 samples, 14%) showed significant higher neoantigen burden compared with NoMut group in ADC and SQCC (mean 32.17/15.22 and 34.75/19.83 mutation/mbp, respectively, both P<0.01). In addition, the Mut group demonstrated higher infiltration of activated CD8 T cells compared with the NoMut group in ADC (39%/25%, P<0.01). However, there was no significant difference between two groups in SQCC (32%/27%, P=0.42).
For two representative genes (SMARCA2 and PBRM1), lower expression of the two genes were associated with higher infiltration of activate CD8 T-cells in ADC (60%/6% and 37%/17%, respectively, both P<0.01) and SQCC (40%/21% and 43%/17%, respectively, both P<0.01). However, there was no difference in neoantigen burden with respect to gene expression in either ADC or SQCC.
Mutation or low expression of chromatin remodeling genes including SMARCA2 and PBRM1 were associated with higher neoantigen burden and higher tumor infiltration of activated CD8 T-cells in human NSCLC.6f8b794f3246b0c1e1780bb4d4d5dc53