American Association for Cancer Research
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FIGURE 2 from Humanized Patient-derived Xenograft Models of Disseminated Ovarian Cancer Recapitulate Key Aspects of the Tumor Immune Environment within the Peritoneal Cavity

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posted on 2024-05-06, 10:20 authored by Mara P. Steinkamp, Irina Lagutina, Kathryn J. Brayer, Fred Schultz, Danielle Burke, Vernon S. Pankratz, Sarah F. Adams, Laurie G. Hudson, Scott A. Ness, Angela Wandinger-Ness

High M-CSF production influences the development of myeloid cells in huNBSGW PDX. A, Diagram of the huPDX study. B, Change in human CD45+ cell populations in peripheral blood before tumor engraftment versus end stage for each mouse (n = 3 mice/group). CD19+ B cells, CD3+ T cells, and CD11b+ myeloid cells make up the majority of human immune cells in the blood. Note that terminal samples from huPDX9 ms3 were not collected as the mouse died unexpectedly overnight. Mouse numbers are listed as ms1–3. C, Average percentage of human myeloid cells in the peripheral blood of huPDX before and after tumor challenge (values are the average ± SD). P values are based on an unpaired two-tailed Student t test. ***, P < 0.0005; **, P < 0.005; *, P < 0.05; n.s., not significant). D, Percentage of CD11b+ human myeloid cells in huPDX ascites fluid at end stage. E, M-CSF concentration in patient ascites fluid measured by ELISA. Samples were assayed in duplicate. Error bars are SD. F, M-CSF concentrations in PDX ascites fluid measured by cytokine array. G, M-CSF gene expression levels in patient samples as determined by RNA-seq analysis of primary patient samples and non-huPDX samples. H, GMCSF concentrations in PDX ascites fluid measured by cytokine array. Black dots represent the value for each sample. Bars are the average level and error bars are SEM. H = humanized NH = non-humanized.


HHS | NIH | National Cancer Institute (NCI)

UNM | School of Medicine, University of New Mexico (UNM SOM)



The importance of the immune microenvironment in ovarian cancer progression, metastasis, and response to therapies has become increasingly clear, especially with the new emphasis on immunotherapies. To leverage the power of patient-derived xenograft (PDX) models within a humanized immune microenvironment, three ovarian cancer PDXs were grown in humanized NBSGW (huNBSGW) mice engrafted with human CD34+ cord blood–derived hematopoietic stem cells. Analysis of cytokine levels in the ascites fluid and identification of infiltrating immune cells in the tumors demonstrated that these humanized PDX (huPDX) established an immune tumor microenvironment similar to what has been reported for patients with ovarian cancer. The lack of human myeloid cell differentiation has been a major setback for humanized mouse models, but our analysis shows that PDX engraftment increases the human myeloid population in the peripheral blood. Analysis of cytokines within the ascites fluid of huPDX revealed high levels of human M-CSF, a key myeloid differentiation factor as well as other elevated cytokines that have previously been identified in ovarian cancer patient ascites fluid including those involved in immune cell differentiation and recruitment. Human tumor-associated macrophages and tumor-infiltrating lymphocytes were detected within the tumors of humanized mice, demonstrating immune cell recruitment to tumors. Comparison of the three huPDX revealed certain differences in cytokine signatures and in the extent of immune cell recruitment. Our studies show that huNBSGW PDX models reconstitute important aspects of the ovarian cancer immune tumor microenvironment, which may recommend these models for preclinical therapeutic trials. huPDX models are ideal preclinical models for testing novel therapies. They reflect the genetic heterogeneity of the patient population, enhance human myeloid differentiation, and recruit immune cells to the tumor microenvironment.