Abstract 4785
Background
Thymoma and thymic carcinoma (TC) are rare diseases of thymus with relatively good prognosis. Different pathological sub-types of thymoma and TC show clear differences on clinical characteristics, morphology, molecular markers, and prognosis.
Methods
In this study, 26 thymoma and thymic carcinoma patients with most common thymic epithelial tumor subtypes were enrolled, including 2 type A, 6 type AB, 3 type B1, 1 type B1/B2, 5 type B2, 2 type B2/B3, 4 type B3, and 3 type TC patients in total. The frozen tissues of all patients were processed for RNA-seq sequencing.
Results
We used unsupervised clustering to divide all samples into 5 clusters. Four clusters showed clear concordance with pathological subtypes, i.e. cluster AB (5 AB, 1 B1, and 2 B2), cluster B1/B2 (2 B1, 1 B1/B2, and 2B2), cluster B2/B3 (1 B2, 1 B2/B3, and 2B3), and cluster TC (3 TC and 1 A). Only one cluster (1 A, 1 AB, and 2 B3) was labeled as cluster A/AB according to the result of joint clustering analysis with TCGA THYM RNA-seq data. We performed gene function enrichment analysis on highly expressed genes in each cluster. Cluster A showed gene function enrichment on two development related pathways (nervous system development and epithelium development) and cell differentiation. Cluster AB had enriched function of cell proliferation and regulation of cell development. Cluster B1/B2 did not show any enriched functions. Cluster B2/B3 showed gene function enrichment of cell adhesion and regulation of developmental process. CD274 (PD-L1) was also highly expressed in this cluster. Cluster TC had enriched function of several pathways, including cell adhesion, cell migration, cell differentiation, immune system process, immune response, and nervous system development. Moreover, PI3K-Akt signaling pathway, pathway in cancer, and transcriptional misregulation in cancer were also enriched in cluster TC’s highly expressed genes.
Conclusions
Thymic epithelial tumor subtypes show clearly different expression profiles. The highly expressed genes of each subtype relate to development, immune, and cancer related functions. PD-L1 is highly expressed in B2/B3 samples which suggests potential immunotherapy for the subtypes.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Peking Union Medical College Hospital.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5939 - Matrix metalloproteinases and their tissue inhibitors genes abnormal DNA methylation in breast cancer
Presenter: Olga Simonova
Session: Poster Display session 1
Resources:
Abstract
2703 - Uveal melanoma cell lines depend on multiple signaling pathways for survival
Presenter: John Park
Session: Poster Display session 1
Resources:
Abstract
4849 - XAF1 and ZNF313 complex stimulates ER stress-induced apoptosis via direct GRP78 inhibition.
Presenter: Sungchan Jang
Session: Poster Display session 1
Resources:
Abstract
4801 - XAF1 assembles a destructive complex to induce BRCA1-mediated apoptosis via suppressing ERa and switching estrogen function
Presenter: Seung-hun Jang
Session: Poster Display session 1
Resources:
Abstract
3416 - Cancer associated fibroblasts promote cancer progression via Wnt2 secretion in colorectal cancer
Presenter: Hideaki Karasawa
Session: Poster Display session 1
Resources:
Abstract
4273 - Paired-related homeobox 1 overexpression promotes invasion and metastasis and is a prognostic factor for worse disease-free survival in patients with lung cancer
Presenter: Jung-jyh Hung
Session: Poster Display session 1
Resources:
Abstract
4241 - LncRNA-GC1 contributes to gastric cancer chemo-resistance through inhibition of miR-551b-3p and the overexpression of dysbindin
Presenter: Xin Guo
Session: Poster Display session 1
Resources:
Abstract
5388 - GLPG 1790, a new selective EPHA2 inhibitor, is active in colorectal cancer cell lines belonging to the CMS4/mesenchymal-like subtype
Presenter: Pietro Paolo Vitiello
Session: Poster Display session 1
Resources:
Abstract
5208 - Characterisation of growth hormone signal transduction in primary melanoma cell lines
Presenter: Karla Sousa
Session: Poster Display session 1
Resources:
Abstract
3156 - LAPTM5 protein can regulate TGF-β mediated MAPK and Smad signaling pathways in ovarian cancer cell
Presenter: Yan Gao
Session: Poster Display session 1
Resources:
Abstract