Co-Expression Analysis Reveals Mechanisms Underlying the Varied Roles of NOTCH1 in NSCLC

Abstract

Introduction: Notch receptor family dysregulation can be tumor promoting or suppressing depending on cellular context. Our studies shed light on the mechanistic differences that are responsible for NOTCH1's opposing roles in lung adenocarcinoma and lung squamous cell carcinoma. Methods:We integrated transcriptional patient-derived datasets with gene co-expression analyses to elucidate mechanisms behind NOTCH1 function in subsets of NSCLC. Differential co-expression was examined using hierarchical clustering and principal component analysis. Enrichment analysis was used to examine pathways associated with the underlying transcriptional networks. These pathways were validated in vitro and in vivo. Endogenously epitope-tagged NOTCH1 was used to identify novel interacting proteins.Results: NOTCH1 co-expressed genes in lung adenocarcinoma and squamous carcinoma were distinct and associated with either angiogenesis and immune system pathways or cell cycle control and mitosis pathways, respectively. Tissue culture and xenograft studies of lung adenocarcinoma and lung squamous models with NOTCH1 knockdown showed growth differences and opposing effects on these pathways. Differential NOTCH1 interacting proteins were identified as potential mediators of these differences.Conclusions: Recognition of the opposing role of NOTCH1 in lung cancer, downstream pathways, and interacting proteins in each context may help direct the development of rational NOTCH1 pathway-dependent targeted therapies for specific tumor subsets of NSCLC.

Predicting ROR1/BCL2 combination targeted therapy of small cell carcinoma of the lung

“…To knockdown ROR1 expression, we used ROR1 Mission shRNAs (Sigma, SHCLNG-TRCN0000002024 and SHCLNG-TRCN0000002025) or non-targeting control (Sigma, SHCO16). Lentiviral particles were produced by transfecting 293FT packaging cells with packaging-psPAX2, envelope-pMD2.G and shRNA plasmid as previously described 19 .…”

Differential Co-Expression Analyses Allow the Identification of Critical Signalling Pathways Altered during Tumour Transformation and Progression

“…The opposing roles of the same gene in different cellular contexts, a widespread feature of cancer genes (e.g., Wnt5a, TGFbeta or p63 context-specific oncogenic and tumour-suppressive activity [ 146 , 147 , 148 ]) can be elucidated by this means. Surprisingly, only NOTCH1 has been investigated by differential co-expression, in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) [ 149 ], predicting and then validating it as a pro-proliferative factor in LUAD, while acting as a tumour suppressor in LUSC.…”

The role of developmental signaling pathways in non-small cell lung carcinoma

“…The first Notch receptor variant, Notch-1, has an ambiguous role in NSCLC since its expression is predictive of different outcomes based on the analyzed cancer subtype; while it has a protective role in AC and is associated with longer OS, it does not have a protective role in SCC [53,54]. In AC, Notch-1 correlated with vascular pathways and immune markers while in SCC, it was associated with increased cell proliferation and mitotic genes [55]. Its co-expression with c-met correlated with staging and OS in resected tumors.…”