Biology subjects

Carraway, K. L.

Publications and source records attributed to Carraway, K. L..

3 recordsLinked to original sources

bioRxiv2022

Transformation of Human Mesenchymal Stem Cells into High-Grade Sarcomas by YAP1 and K-RAS Reflects the Undifferentiated Pleomorphic Sarcoma-Myxofibrosarcoma Disease Spectrum

High-grade complex karyotype sarcomas are a heterogeneous group of more than seventy tumors that vary in histology, clinical course, and patient demographics. Despite these clear differences, these high-grade sarcomas are treated similarly with a uniformly high metastatic rate. Pre-clinical models that allow for rigorous comparisons of distinct human sarcoma subtypes would advance insights into the relationships between sarcomas and inform therapeutic decisions. We describe the robust transformation of human mesenchymal stem cells into multiple subtypes of high-grade sarcoma. Using a pooled genetic screening approach, we identified key drivers and potential modifiers of transformation. YAP1 and KRAS were validated as drivers of two distinct sarcoma subtypes, undifferentiated pleomorphic sarcoma (UPS) and myxofibrosarcoma (MFS), respectively. In addition, the pathology of tumors driven by CDK4 and PIK3CA reflected leiomyosarcoma (LMS) and osteosarcoma (OS) indicating that further iterations of this model could result in additional sarcoma subtypes. Histologically and phenotypically these tumors reflect human sarcomas including the pathognomonic complex karyotype. In addition, CDK4 and PIK3CA driven tumors demonstrated endogenous YAP1 amplification which is seen across a subset of human tumors. While all tumors overlapped transcriptionally with the TCGA sarcoma data, further analysis confirmed that YAP1 and KRAS tumors recapitulate the UPS and MFS subtypes. Co-analysis of TCGA and model tumors support that these sarcoma subtypes lie along a spectrum of disease and adds guidance for further transcriptome-based refinement of sarcoma subtyping. Within complex karyotype sarcomas, there are multiple genetic changes but identifying those that are clinically relevant has been challenging. Comparing differentially expressed genes in YAP1 and KRAS tumors to human UPS and MFS identified the enrichment of oxidative phosphorylation pathways in both YAP1 tumors and UPS. Treatment of a panel of sarcoma cell lines with the combination of an oxidative phosphorylation inhibitor and Hippo pathway inhibitor led to a significant impairment in growth identifying new therapeutic targets. A subset of human UPS tumors showed an even greater enrichment in these pathways indicating this model can be used to identify clinically relevant subtypes. This model can be used to begin to understand pathways and mechanisms driving human sarcoma development, the relationship between sarcoma subtypes and to identify and test new therapeutic vulnerabilities for this aggressive and heterogeneous disease. Statement of SignificanceWe have created the first model to study the development, growth, and metastasis of multiple human sarcoma subtypes. This system can be used as a platform to investigate sarcoma biology and identify new therapeutic targets across a heterogeneous disease.

cancer biology↗

bioRxiv2022

Wnt/PCP signaling mediates breast cancer metastasis by promoting pro-invasive protrusion formation in collectively motile leader cells

As evidence supporting essential roles for collective cell migration in carcinoma metastasis continues to accumulate, a better understanding of the underlying cellular and molecular mechanisms will be critical to translating these findings to the treatment of advanced cancers. Here we report that Wnt/PCP, a non-canonical Wnt signaling pathway, mediates breast cancer collective migration and metastasis. We observe that mammary gland-specific knockout of Vangl2, a tetraspanin-like scaffolding protein required for Wnt5a-induced signaling and motility in cultured breast cancer cell lines, results in a striking decrease in metastatic efficiency but not primary tumor growth in the MMTV-NDL transgenic mouse model of HER2-positive breast cancer. We also observe that expression levels of core Wnt/PCP components Wnt5a, Vangl1 and Vangl2 are selectively elevated in K14-positive leader cells relative to follower cells within a collectively migrating cohort, and that Vangl2 expression selectively promotes RhoA activation in leading edge cells. Moreover, Vangl expression drives collective migration in three-dimensional ex vivo tumor organoids, and Vangl protein specifically accumulates within pro-migratory filamentous actin-rich protrusions of leader cells. Together, our observations point to a model whereby Wnt/PCP upregulation facilitates breast tumor collective cell motility by selectively augmenting the formation pro-migratory protrusions within leader cells.

cancer biology↗

bioRxiv2021

Ligand-induced transmembrane conformational coupling in monomeric EGFR

Single pass cell surface receptors regulate cellular processes by transmitting ligand-encoded signals across the plasma membrane via changes to their extracellular and intracellular conformations. While receptor-receptor interactions are established as key aspects of transmembrane signaling, the contribution from the single helix of a monomeric receptor has been challenging to isolate due to the complexity and ligand-dependence of the receptor-receptor interactions. By combining membrane nanodiscs produced wtih cell-free expression, single-molecule Forster Resonance Energy Transfer measurements, and molecular dynamics simulations, we report that ligand binding induces intracellular conformational changes within monomeric, full-length epidermal growth factor receptor (EGFR). Our observations establish the existence of extracellular/intracellular conformational coupling within a single receptor molecule. We implicate a series of electrostatic interactions in the conformational coupling and find the coupling is inhibited by targeted therapeutics and mutations that also inhibit phosphorylation in cells. Collectively, these results introduce a facile mechanism to link the extracellular and intracellular regions through the single transmembrane helix of monomeric EGFR, and raise the possibility that intramolecular transmembrane conformational changes are common to single-pass membrane proteins.

biophysics↗