Biology subjects

Pirkey, A. C.

Publications and source records attributed to Pirkey, A. C..

4 recordsLinked to original sources

bioRxiv2026

Cell Communication Network factor 4 promotes tumor-induced immunosuppression in breast cancer.

Cell Communication Network factor 4 (CCN4/WISP1) is a matricellular protein secreted by cancer cells that is upregulated in essentially all invasive breast cancers and promotes immunosuppression in melanoma. Recent work suggests that limited anti-tumor immunity also associates with poor patient outcomes in patients with breast cancer. Motivated by increased CCN4 correlating with dampened anti-tumor immunity in primary breast cancer, we test for a direct causal link by knocking out CCN4 (CCN4 KO) in the Py230 and Py8119 mouse breast cancer models. Tumor growth is reduced when CCN4 KO breast cancer cells are implanted in immunocompetent but not in immunodeficient mice. Correspondingly in size-matched tumors, CD4+ and CD8+ T cells are significantly increased in CCN4 KO tumors while the myeloid compartment is shifted from polymorphonuclear- to monocytic-myeloid-derived suppressor cells (MDSC). This shift in the MDSC compartment is also associated with a significant reduction in splenomegaly. Among mechanisms linked to local immunosuppression, CCN4 knockout has a similar impact on the secretome of both breast cancer and melanoma cell lines. Overall, our results suggest that CCN4 promotes tumor-induced immunosuppression in the context of breast cancer and is a potential target for therapeutic combinations with immunotherapies.

cancer biology↗

bioRxiv2022

Head-to-head comparison of CCN4, DNMT3A, PTPN11, and SPARC as suppressors of anti-tumor immunity

BackgroundEffective communication between innate and adaptive immunity is essential for mounting an effective antitumor immune response. Emergent cancer cells likely secrete factors that inhibit this communication. To identify such factors, we applied an in vitro workflow that coupled a functional assay with proteomics to a syngeneic mouse model of melanoma known to be resistant to immunotherapies. Collectively, these in vitro results suggested CCN4, DNMT3A, PTPN11, and SPARC as secreted factors that potentially mediate immunosuppression and could potentially become easily accessible targets for novel immunotherapies. The objective of this study was to test for consistent clinical correlates in existing human data and to verify in vivo whether knocking out tumor cell production of these secreted factors improved immune-mediated control of tumor growth. ResultsAnalyses of available human data indicate that high CCN4 expression is associated with reduced survival in primary melanoma patients. High DNMT3A, PTPN11, and SPARC expression showed no association with overall survival. In addition, scRNAseq data from patients with melanoma confirmed CCN4 is expressed by the tumor cells, as opposed to other cells in the tumor microenvironment. An experimental system was created using a CRISPR/Cas9 approach to generate knock out cell lines for each of the four genes of interest using the B16F0 mouse melanoma cell line. In a immunocompetent C57BL/6, DNMT3A, PTPN11, and SPARC knockouts had no effect on overall survival compared to mice challenged with wildtype B16F0 cells while the CCN4 knockout significantly increased survival. This increase in overall survival was lost when the CCN4 knockout cells were injected into severely immunocompromised NSG hosts, indicating that CCN4s effect on the tumor microenvironment is immune mediated. A kinetic analysis leveraging a Markov Chain Monte Carlo approach quantified the various knockouts effect on cells intrinsic growth rate. The analysis shows CCN4 is the only knockout tested that decreased the net proliferation rate in immunocompetent mice compared to wildtype cells. ConclusionsThe results suggest that CCN4 is a mediator of immunosuppression in the melanoma tumor microenvironment and a potential collateral immunotherapy target.

cancer biology↗

bioRxiv2021

Cell Communication Network factor 4 promotes tumor-induced immunosuppression in melanoma

Immune cell composition within the tumor microenvironment is regulated by tumor-derived factors. Cell Communication Network factor 4 (CCN4/WISP1) is a matricellular protein secreted by cancer cells that promotes metastasis by inducing the epithelial-mesenchymal transition. While metastatic dissemination limits patient survival, the absence of anti-tumor immunity also associates with poor patient out-comes with recent work suggesting these two clinical correlates are linked. Motivated by finding that CCN4 was associated with a dampened anti-tumor immune contexture in patients diagnosed with primary melanoma, we tested for a direct causal link by knocking out CCN4 (CCN4-KO) in the B16F0 and YUMM1.7 mouse models for melanoma. Tumor growth was significantly reduced when CCN4-KO melanoma cells were implanted subcutaneously in immunocompetent C57BL/6 mice but not in immunodeficient NSG mice. Correspondingly, the frequency of total CD45+ tumor-infiltrating leukocytes was significantly increased in CCN4-KO tumors, with increased natural killer (NK) and effector CD8+ T cells and reduced myeloid-derived suppressor cells (MDSC). Additionally, the absence of tumor-derived CCN4 was associated with an impaired splenic generation of suppressive granulocytic MDSC. Among mechanisms linked to local immunosuppression, we found CCN4 directly suppressed antigen-induced IFN{gamma} release by CD8+ T cells, promoted glycolysis and consequent lactate release by melanoma cells, and enhanced tumor secretion of MDSC-attracting chemokines like CCL2 and CXCL1. Finally, CCN4-KO in B16F0 and YUMM1.7 melanoma cells complemented the anti-tumor effect of immune checkpoint blockade (ICB) therapy. Overall, our results suggest that CCN4 promotes tumor-induced immunosuppression and is a potential target for therapeutic combinations with ICB. Statement of SignificanceGiven emerging interest in understanding the interplay between functional plasticity and anti-tumor immunity, Cell Communication Network factor 4, a secreted matricellular protein linked to promoting metastasis in melanoma, also suppresses anti-tumor immunity.

cancer biology↗

bioRxiv2020

Data-driven learning how oncogenic gene expression locally alters heterocellular networks

Discovering and developing pharmaceutical drugs increasingly relies on mechanistic mathematical modeling and simulation. In immuno-oncology, models that capture causal relations among genetic drivers of oncogenesis, functional plasticity, and host immunity provide an important complement to wet experiments, given the cellular complexity and dynamics within tumors. Unfortunately, formulating such mechanistic cell-level models currently relies on hand curation by experts, which can bias how data is interpreted or the priority of drug targets. In modeling molecular-level networks, rules and algorithms have been developed to limit a priori biases in formulating mechanistic models. To realize an equivalent approach for cell-level networks, we combined digital cytometry with Bayesian network inference to generate causal models that link an increase in gene expression associated with onco-genesis with alterations in stromal and immune cell subsets directly from bulk transcriptomic datasets. To illustrate, we predicted how an increase in expression of Cell Communication Network factor 4 (CCN4/WISP1) altered the tumor microenvironment using data from patients diagnosed with breast cancer and melanoma. Digital cytometry and network inference predictions were then tested using two immunocompetent mouse models for melanoma, which provided consistent experimental results.

systems biology↗