Identification of clinically predictive metagenes that encode components of a network coupling cell shape to transcription by image-omics

Abstract

The associations between clinical phenotypes (tumour grade, survival), and cell phenotypes, such as shape, signalling activity, and gene expression, are the basis for cancer pathology; but the mechanisms explaining these relationships are not always clear. The generation of large datasets containing information regarding cell phenotypes, and clinical data, provides an opportunity to describe these mechanisms. Here we develop an image-omics approach to integrate quantitative cell imaging data, gene expression, and protein-protein interaction data to systematically describe a 'shape-gene network' that couples specific aspects of breast cancer cell shape to signalling and transcriptional events. The actions of this network converge on NF-κB, and support the idea that NF-κB is responsive to mechanical stimuli. By integrating RNAi screening data, we identify components of the shape-gene network that regulate NF-κB in response to cell shape changes. This network was also used to generate metagene models that predict NF-κB activity, and aspects of morphology such as cell area, elongation, and protrusiveness. Critically, these metagenes also have predictive value regarding tumour grade and patient outcomes. Taken together, these data strongly suggest that changes in cell shape, driven by gene expression and/or mechanical forces, can promote breast cancer progression by modulating NF-κB activation. Our findings highlight the importance of integrating phenotypic data at the molecular level (signalling and gene expression), with those at the cellular and tissue levels to better understand breast cancer oncogenesis.