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Hollingsworth, M. A.

Publications and source records attributed to Hollingsworth, M. A..

9 recordsLinked to original sources

An Integrated Preclinical Platform for Lethal Neuroendocrine Prostate Cancer from Rapid Autopsy Bone and Liver Metastases.

Treatment-emergent neuroendocrine prostate cancer (NEPC) is an aggressive, therapy-resistant disease arising in up to 20% of castration resistant prostate cancers, yet robust biologically relevant preclinical models remain scarce. Here, we describe a technical blueprint for establishing an integrated platform of patient-derived models from visceral and bone metastases collected through a prostate cancer rapid autopsy program (PC RAP). We report the establishment and characterization of patient-derived xenograft (PDX) models from liver metastasis tissue, liver and bone metastasis-derived organoid lines (PDOs), and corresponding patient-derived organoid xenograft (PDOX) models. In addition, we established, to our knowledge, the first mesenchymal stem cell (MSC) cultures derived from neuroendocrine prostate cancer (NEPC) bone metastases. The PDOs preserved intratumoral heterogeneity, displaying both CRPC-NE and CRPC-adenocarcinoma features. These organoids retained neuroendocrine identity across multiple passages, with transcriptomic profiles concordant with the original patient tissue and matched PDX models generated at our institution and at the National Cancer Institute (NCI Patient-Derived Models Repository). To model the bone metastatic microenvironment, we generated novel organoid-based New Approach Methodologies (NAMs) by co-culturing PDOs with iPSC-derived bone marrow organoids, establishing a physiologically relevant vascularized organotypic model of PC bone metastasis. To extend our studies in vivo, we established preclinical models using the liver and bone metastasis-derived organoid models. The PDOX models were tumorigenic and developed spontaneous lymph node metastases, providing clinically relevant models for investigating lethal NEPC biology. Together, these complementary patient-derived models provide a robust and versatile platform for investigating NEPC biology, metastatic progression, and evaluating new therapeutic strategies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=184 SRC="FIGDIR/small/740121v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@1c641f1org.highwire.dtl.DTLVardef@113696aorg.highwire.dtl.DTLVardef@16dcc72org.highwire.dtl.DTLVardef@1898d9f_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LINovel preclinical models of visceral and bone metastases established from a prostate cancer rapid autopsy program. C_LIO_LIThis study is the first to establish mesenchymal stem cell cultures from NEPC bone metastases. C_LIO_LIPDOs preserve heterogeneity, showing both CRPC-NE and CRPC-Adeno features, with transcriptomic profiles concordant with originator tissue and PDX models. C_LIO_LIPC RAP-derived organoids are tumorigenic in vivo and generate spontaneous lymph node metastases. C_LI

cancer biology↗

An Iron-regulated Signalling Pathway Controls Adipose Browning and Cancer Cachexia

The browning and atrophy of white adipose tissue (WAT) are early events in cachexia, a lethal metabolic disorder affecting nearly half of cancer patients, including those with pancreatic ductal adenocarcinoma (PDA). Using patient-derived specimens and PDA mouse models, we identified perturbations in iron metabolism and proteinaceous methionine oxidation as key initiating events of adipose browning. In particular, the iron influxes that accompany WAT browning induce the activity of methionine sulfoxide reductase A (MSRA), an enzyme that reverses the oxidation of proteinaceous methionine residues. Mechanistically, iron coordination by the conserved iron-binding motifs (E203-xx-H206) of two MSRA polypeptides serves to multimerize, stabilize, and enzymatically activate MSRA. This in turns facilitates adipose browning by maintaining the reduced state of two methionines near the ATP-binding site of Protein Kinase A (PKA). Remarkably, in mouse models of PDA, MsrA deletion impairs WAT browning, significantly mitigates cachexia, and improves the overall survival of tumor-bearing animals. By establishing the iron-MSRA-PKA axis as a key nexus of cancer-associated cachexia, our study offers new perspectives for the treatment of this condition.

cancer biology↗

AI-powered Deep Visual Proteomics reveals critical molecular transitions in pancreatic cancer precursors

Pancreatic ductal adenocarcinoma (PDAC) evolves through non-invasive precursor lesions, yet its earliest molecular events remain unclear. We established the first spatially resolved proteomic atlas of these lesions using Deep Visual Proteomics (DVP). AI-driven computational pathology classified normal ducts, acinar-ductal metaplasia (ADM), and pancreatic intraepithelial neoplasia (PanIN) from cancer-free organ donors (incidental, "iPanINs") and PDAC patients (cancer-associated, "cPanINs"). Laser microdissection of 96 discrete regions containing as few as 100 phenotypically matched cells and ultrasensitive mass spectrometry quantified a total of 8,512 proteins from formalin-fixed tissues. Distinct molecular signatures stratifying cPanINs from iPanINs, and remarkably, many cancer-associated proteins already marked histologically normal epithelium. Four core programs - stress adaptation, immune engagement, metabolic reprogramming, mitochondrial dysfunction - emerged early and intensified during progression. By integrating DVP with AI-guided tissue annotation, we demonstrate that molecular reprogramming precedes histological transformation, creating opportunities for earlier detection and interception of a near-uniformly lethal cancer. SignificanceOur spatially-resolved proteomics atlas uncovers distinct molecular signatures in pancreatic cancer adjacent precursor lesions, clearly diverging from those in incidental, cancer-free pancreatic lesions. Our deep proteomics dataset offers a valuable resource for identifying novel biomarkers and therapeutic targets, informed by the earliest cancer-associated molecular events in archival pancreatic tissues.

cancer biology↗

Spatial Proteomics of the Normal Breast Collagen Stroma: Links to BI-RADS Categories and Body Mass Index

Collagen breast stroma is the basis of increased breast density and a well-established breast cancer risk factor, yet proteomic regulation of normal breast stroma remains poorly defined. This study reports spatial regulation of the collagen proteome in normal breast tissue sections annotated by clinical characteristics. Normal breast samples from the Susan G. Komen tissue bank included data on genetic ancestry (n=40 total; n=20 African ancestry; n=20 European ancestry), body-mass-index (BMI), age, and mammogram density by the Breast Imaging Reporting and Data System (BI-RADS). Multiplexed cell marker staining showed CD44 and COL1A1 markers modulated with BMI. Collagen fiber widths by second harmonic generation (SHG) showed potential contrasts in BMI categories by genetic ancestry. Targeted extracellular matrix proteomics mass spectrometry imaging showed collagen alpha-1(I) chain domain proteome was spatially heterogenous across the normal breast microenvironment with site specific post-translational modification of proline hydroxylation. Signatures computationally extracted from breast stroma reported that 47 collagen peptides distinguished BI-RADS categories (area under the receiver operating curve>0.7; p-value>0.05). Proteomic alterations were found between overweight to obese categories with strong positive associations to BMI by multivariate analysis. This study provides the first spatial analysis of the collagen proteome in normal breast within contexts of cellular markers and clinical characteristics.

cancer biology↗

Pancreatic cancer cachexia is mediated by PTHrP-driven disruption of adipose de novo lipogenesis

Pancreatic cancer patients have the highest rates and most severe forms of cancer cachexia, yet cachexia etiologies remain largely elusive, leading to a lack of effective intervening therapies. Parathyroid hormone-related protein (PTHrP) has been clinically implicated as a putative regulator of cachexia, with serum PTHrP levels correlating with increased weight loss in PDAC patients. Here we show that cachectic PDAC patients have high expression of tumor PTHrP and use a genetically engineered mouse model to functionally demonstrate that loss of PTHrP blocks cachectic wasting, dramatically extending overall survival. The re-expression of PTHrP in lowly cachectic models is sufficient to induce wasting and reduce survival in mice, which is reversed by the conditional deletion of the PTHrP receptor, Pth1r, in adipocytes. Mechanistically, tumor-derived PTHrP suppresses de novo lipogenesis in adipocytes, leading to a molecular rewiring of adipose depots to promote wasting in the cachectic state. Finally, the pharmacological disruption of the PTHrP-PTH1R signaling axis abrogates wasting, highlighting that a targeted disruption of tumor-adipose crosstalk is an effective means to limit cachexia. STATEMENT OF SIGNIFICANCEPancreatic ductal adenocarcinoma (PDAC) is the prototypical cancer type associated with cancer cachexia, a debilitating wasting syndrome marked by adipose tissue loss and muscle atrophy. Herein, we establish that PTHrP is a tumor-derived factor that facilitates cachexia by downregulating de novo lipogenesis in adipocytes and that blocking PTHrP is an effective means to limit wasting in preclinical mouse models.

cancer biology↗

The circadian gene Dec2 promotes pancreatic cancer dormancy by regulating tumor cell antigen presentation to facilitate immune evasion

The mechanisms that regulate cancer dormancy remain poorly understood. Using a mouse model of resectable pancreatic adenocarcinoma (PDAC), we identified Dec2 as a gene that was upregulated in metastatic dormant tumor cells. Deletion of Dec2 from tumor cells substantially increased mouse survival after resection due to an immune-mediated mechanism as the survival benefit was abrogated in immunodeficient conditions. Dec2 promoted immune evasion by repressing multiple components of the MHC-I dependent antigen presentation pathway in tumor cells. Dec2 is a regulator of circadian rhythms, and we found several components of the antigen presentation pathway oscillated in a circadian manner that was lost upon deletion of Dec2. Moreover, T-cell mediated tumor cell killing varied depending on the time of day. We suggest that lowered MHC-I presentation of antigens during rest phase is a natural effect of the circadian clock, which is exploited by Dec2-overexpressing pancreatic tumors to evade the immune system.

cancer biology↗

DHODH inhibition enhances the efficacy of immune checkpoint blockade by increasing cancer cell antigen presentation

Pyrimidine nucleotide biosynthesis is a druggable metabolic dependency of cancer cells, and chemotherapy agents targeting pyrimidine metabolism are the backbone of treatment for many cancers. Dihydroorotate dehydrogenase (DHODH) is an essential enzyme in the de novo pyrimidine biosynthesis pathway that can be targeted by clinically approved inhibitors. However, despite robust preclinical anticancer efficacy, DHODH inhibitors have shown limited single-agent activity in phase 1 and 2 clinical trials. Therefore, novel combination therapy strategies are necessary to realize the potential of these drugs. To search for therapeutic vulnerabilities induced by DHODH inhibition, we examined gene expression changes in cancer cells treated with the potent and selective DHODH inhibitor brequinar (BQ). This revealed that BQ treatment causes upregulation of antigen presentation pathway genes and cell surface MHC class I expression. Mechanistic studies showed that this effect is 1) strictly dependent on pyrimidine nucleotide depletion, 2) independent of canonical antigen presentation pathway transcriptional regulators, and 3) mediated by RNA polymerase II elongation control by positive transcription elongation factor B (P-TEFb). Furthermore, BQ showed impressive single-agent efficacy in the immunocompetent B16F10 melanoma model, and combination treatment with BQ and dual immune checkpoint blockade (anti-CTLA-4 plus anti-PD-1) significantly prolonged mouse survival compared to either therapy alone. Our results have important implications for the clinical development of DHODH inhibitors and provide a rationale for combination therapy with BQ and immune checkpoint blockade.

cancer biology↗

Porcine pancreatic ductal epithelial cells transformed with KRASG12D and SV40T are tumorigenic

We describe our initial studies in the development of an orthotopic, genetically-defined, large animal model of pancreatic cancer. Primary pancreatic epithelial cells were isolated from pancreatic duct of domestic pigs. A transformed cell line was generated from these primary cells with oncogenic KRAS and SV40T. The transformed cell lines outperformed the primary and SV40T immortalized cells in terms of proliferation, population doubling time, soft agar growth, transwell migration and invasion. The transformed cell line grew tumors when injected subcutaneously in nude mice, forming glandular structures and staining for epithelial markers. Future work will include implantation studies of these tumorigenic porcine pancreatic cell lines into the pancreas of allogeneic and autologous pigs. The resultant large animal model of pancreatic cancer could be utilized for preclinical research on diagnostic, interventional, and therapeutic technologies.

cancer biology↗

Generation of tumorigenic porcine pancreatic ductal epithelial cells: toward a large animal model of pancreatic cancer

Background. A large animal model of pancreatic cancer would permit development of diagnostic and interventional technologies not possible in murine models, and also would provide a more biologically-relevant platform for penultimate testing of novel therapies, prior to human testing. Here, we describe our initial studies in the development of an autochthonous, genetically-defined, large animal model of pancreatic cancer, using immunocompetent pigs.\n\nMethods. Primary pancreatic epithelial cells were isolated from pancreatic duct of domestic pigs; epithelial origin was confirmed with immunohistochemistry. Three transformed cell lines subsequently were generated from these primary cells using expression of oncogenic KRAS and dominant negative p53, with/without knockdown of p16 and SMAD4. We tested these cell lines using in vitro and in vivo assays of transformation and tumorigenesis.\n\nResults. The transformed cell lines outperformed the primary cells in terms proliferation, population doubling time, soft agar growth, 2D migration, and Matrigel invasion, with the greatest differences observed when all four genes (KRAS, p53, p16, and SMAD4) were targeted. All three transformed cell lines grew tumors when injected subcutaneously in nude mice, demonstrating undifferentiated morphology, mild desmoplasia, and staining for both epithelial and mesenchymal markers. Injection into the pancreas of nude mice resulted in distant metastases, particularly when all four genes were targeted.\n\nConclusions. Tumorigenic porcine pancreatic cell lines were generated. Inclusion of four genetic \"hits\" (KRAS, p53, p16, and SMAD4) appeared to produce the best results in our in vitro and in vivo assays. The next step will be to perform autologous or syngeneic implantation of these cell lines into the pancreas of immunocompetent pigs. We believe that the resultant large animal model of pancreatic cancer could supplement existing murine models, thus improving preclinical research on diagnostic, interventional, and therapeutic technologies.

cancer biology↗