We discovered T-cell clonal expansions in benign prostatic hyperplasia, indicative of a specific adaptive immune response and with implications for disease pathogenesis and new treatments.

Benign prostatic hyperplasia (BPH) is a common condition marked by the enlargement of the prostate gland, which often leads to significant urinary symptoms and a decreased quality of life. The development of clinically relevant animal models is crucial for understanding the pathophysiology of BPH and improving treatment options. This study aims to establish a patient-derived xenograft (PDX) model using benign prostatic tissues to explore the molecular and cellular mechanisms of BPH. PDXs were generated by implanting fresh BPH (transition zone) and paired normal (peripheral zone) prostate tissue from 8 patients under the renal capsule of immunodeficient male mice. Tissue weight, architecture, cellular proliferation, apoptosis, prostate-specific marker expression, and molecular profiles of PDXs were assessed after 1 week and 1, 2, or 3 months of implantation by immunohistochemistry, enzyme-linked immunosorbent assay, transcriptomics, and proteomics. Responses to finasteride, a standard-of-care therapy, were evaluated. PDXs maintained histologic and molecular characteristics of the parental human tissues. BPH, but not normal PDXs, demonstrated significant increases in weight and cellular proliferation, particularly at 1 month. Molecular profiling revealed specific gene and protein expression patterns correlating with BPH pathophysiology. Specifically, an increased immune and stress response was observed at 1 week, followed by increased expression of proliferation markers and BPH-specific stromal signaling molecules, such as BMP5 and CXCL13, at 1 month. Graft stabilization to preimplant characteristics was apparent between 2 and 3 months. Treatment with finasteride reduced proliferation, increased apoptosis, and induced morphologic changes consistent with therapeutic responses observed in human BPH. Our PDX model recapitulates the morphologic, histologic, and molecular features of human BPH, offering a significant advancement in modeling the complex interactions of cell types in BPH microenvironments. These PDXs respond to therapeutic intervention as expected, providing a valuable tool for preclinical testing of new therapeutics that will improve the well-being of BPH patients. (c) 2024 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Abstract Background Loss of AZGP1 expression is a biomarker associated with progression to castration resistance, development of metastasis, and poor disease-specific survival in prostate cancer. However, high expression of AZGP1 cells in prostate cancer has been reported to increase proliferation and invasion. The exact role of AZGP1 in prostate cancer progression remains elusive. Method AZGP1 knockout and overexpressing prostate cancer cells were generated using a lentiviral system. The effects of AZGP1 under- or over-expression in prostate cancer cells were evaluated by in vitro cell proliferation, migration, and invasion assays. Heterozygous AZGP1± mice were obtained from European Mouse Mutant Archive (EMMA), and prostate tissues from homozygous knockout male mice were collected at 2, 6 and 10 months for histological analysis. In vivo xenografts generated from AZGP1 under- or over-expressing prostate cancer cells were used to determine the role of AZGP1 in prostate cancer tumor growth, and subsequent proteomics analysis was conducted to elucidate the mechanisms of AZGP1 action in prostate cancer progression. AZGP1 expression and microvessel density were measured in human prostate cancer samples on a tissue microarray of 215 independent patient samples. Result Neither the knockout nor overexpression of AZGP1 exhibited significant effects on prostate cancer cell proliferation, clonal growth, migration, or invasion in vitro. The prostates of AZGP1−/− mice initially appeared to have grossly normal morphology; however, we observed fibrosis in the periglandular stroma and higher blood vessel density in the mouse prostate by 6 months. In PC3 and DU145 mouse xenografts, over-expression of AZGP1 did not affect tumor growth. Instead, these tumors displayed decreased microvessel density compared to xenografts derived from PC3 and DU145 control cells, suggesting that AZGP1 functions to inhibit angiogenesis in prostate cancer. Proteomics profiling further indicated that, compared to control xenografts, AZGP1 overexpressing PC3 xenografts are enriched with angiogenesis pathway proteins, including YWHAZ, EPHA2, SERPINE1, and PDCD6, MMP9, GPX1, HSPB1, COL18A1, RNH1, and ANXA1. In vitro functional studies show that AZGP1 inhibits human umbilical vein endothelial cell proliferation, migration, tubular formation and branching. Additionally, tumor microarray analysis shows that AZGP1 expression is negatively correlated with blood vessel density in human prostate cancer tissues. Conclusion AZGP1 is a negative regulator of angiogenesis, such that loss of AZGP1 promotes angiogenesis in prostate cancer. AZGP1 likely exerts heterotypical effects on cells in the tumor microenvironment, such as stromal and endothelial cells. This study sheds light on the anti-angiogenic characteristics of AZGP1 in the prostate and provides a rationale to target AZGP1 to inhibit prostate cancer progression.

Abstract AZGP1 is involved in various biological processes, including lipid metabolism, regulation of cell proliferation, migration and invasion, and immune response. The loss of AZGP1 is associated with worse clinical outcomes, and AZGP1 has been indicated as a potential biomarker for prostate cancer. However, the underlying mechanisms of AZGP1 function in prostate cancer are unknown. This study reports AZGP1's pivotal involvement in angiogenesis within the prostate cancer tumor environment. Neither knockout nor overexpression of AZGP1 affects in vitro prostate cancer cell proliferation, migration, or invasion. Morphologically, AZGP1-deficient mouse prostates appear normal, but exhibit increased fibroblast growth in periglandular stroma after 6 months. The overexpression of AZGP1 does not impact the growth of PC3 and DU145 tumors; instead, these tumors significantly reduced microvessel density, suggesting AZGP1 exhibits anti-angiogenic properties. Proteomic profiling shows distinct profile of angiogenesis-related proteins between PC3-AZGP1-OV and PC3 control cells, featuring proteins like PDCD6 and MMP9. This study provides insights into the anti-angiogenic attributes of AZGP1 in prostate cancer, underscoring its potential as a therapeutic target for prostate cancer. Citation Format: Ru Wen, G Edward Wen, Zhengyuan Qiu, Eric E Peterson, Fernando Jose Garcia Marques, Abel Bermudez, Jonathan R Pollack, Hongjuan Zhao, Sharon Pitteri, James Brooks. AZGP1 inhibits angiogenesis in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3007.

Benign prostatic hyperplasia (BPH) is the nodular proliferation of the prostate transition zone in older men, leading to urinary storage and voiding problems that can be recalcitrant to therapy. Decades ago, John McNeal proposed that BPH originates with the "reawakening" of embryonic inductive activity by adult prostate stroma, which spurs new ductal proliferation and branching morphogenesis. Here, by laser microdissection and transcriptional profiling of the BPH stroma adjacent to hyperplastic branching ducts, we identified secreted factors likely mediating stromal induction of prostate glandular epithelium and coinciding processes. The top stromal factors were insulin-like growth factor 1 (IGF1) and CXC chemokine ligand 13 (CXCL13), which we verified by RNA in situ hybridization to be coexpressed in BPH fibroblasts, along with their cognate receptors (IGF1R and CXCR5) on adjacent epithelium. In contrast, IGF1 but not CXCL13 was expressed in human embryonic prostate stroma. Finally, we demonstrated that IGF1 is necessary for the generation of BPH-1 cell spheroids and patient-derived BPH cell organoids in 3D culture. Our findings partially support historic speculations on the etiology of BPH and provide what we believe to be new molecular targets for rational therapies directed against the underlying processes driving BPH.

Background: Prostate cancer (PCa) is highly heterogeneous, and while some tumors remain indolent throughout a patient's lifetime, others are highly aggressive, leading to significant morbidity and death. The current methods for PCa diagnosis and prognosis are highly suboptimal, resulting in over-diagnosis and overtreatment of many clinically insignificant tumors. To understand the nature of PCa heterogeneity, we conducted comprehensive genomic analyses on matched samples of adjacent normal prostate tissue, prostate intraepithelial neoplasia (PIN), and invasive PCa. Methods: To investigate the changes cells undergo during PCa development and progression, we analyzed genomic and transcriptomic alterations in 92 adjacent normal, 80 PIN, and 99 PCa samples from 34 patients. For each sample type, both epithelial and stromal components were analyzed separately using laser capture microdissection of formalin fixed paraffin embedded tissue. Transcriptomic analysis was performed using smart3-SEQ and copy number analysis was performed by low-pass whole genome sequencing (WGS). The samples were analyzed as three separate data sets. Results: We studied the spectrum of molecular changes present in both epithelial and stromal samples. A negative-binomial regression model was used to identify differentially expressed genes between adjacent normal prostate tissue and invasive PCa in epithelium and stroma separately using the discovery data set. The resulting gene lists were used to perform non-negative matrix factorization clustering of all samples in the three datasets separately. This analysis identified two epithelial and two stromal clusters with distinct RNA expression profiles in all three data sets. For invasive PCa samples, all except three epithelial samples and five stromal samples clustered in the ‘invasive-like’ clusters. Similarly for adjacent normal samples, all except three of the epithelial and six of the stromal samples clustered as ‘normal-like’ across the three datasets. For PIN samples, 54% of epithelial and 62% of stromal samples classified as ‘normal-like’. We performed phylogenetic analysis of WGS data and identified PIN lesions with and without clear clonal relation to invasive PCa lesions. Recurrent copy number variations were identified in both PIN and PCa lesions. Conclusion. We identified two distinct epithelial and two distinct stromal expression clusters with ‘invasive-like’ and ‘normal-like’ signatures. WGS analysis revealed recurrent copy number alterations in PIN and PCa lesions, and evidence of clonal relationships between PIN and invasive PCa. These studies provide new insight into PIN biology and the relationship between PIN and invasive PCa. Citation Format: Siri H. Strand, Okyaz Eminaga, Sujay Vennam, Chunfang Zhu, Jason Wang, Sushama Varma, Rosalie Nolley, Christian Kunder, Jonathan Pollack, Andreas Roeder, Karina D. Sorensen, James D. Brooks, Robert B. West. Molecular analysis of matched PIN, invasive prostate cancer, and adjacent normal prostate tissue samples reveal distinct transcriptional signatures and clonal relationships [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A017.

Supplementary Figures S1-S3 from A Gene Expression Signature of Genetic Instability in Colon Cancer

Supplementary Tables 1-3, Figures 1-7 from LYN Is a Mediator of Epithelial-Mesenchymal Transition and a Target of Dasatinib in Breast Cancer

Supplementary Figures 1-3, Tables 1-3 from Steroid Receptor Coactivator-3 Expression in Lung Cancer and Its Role in the Regulation of Cancer Cell Survival and Proliferation

Supplementary Figure 1 from Genomic Profiling Reveals Alternative Genetic Pathways of Prostate Tumorigenesis

Supplementary Table S1 from The Retinoic Acid Synthesis Gene ALDH1a2 Is a Candidate Tumor Suppressor in Prostate Cancer

Supplementary Tables S1-S6 from A Gene Expression Signature of Genetic Instability in Colon Cancer

Supplementary Table S2 from The Retinoic Acid Synthesis Gene ALDH1a2 Is a Candidate Tumor Suppressor in Prostate Cancer

Abstract Genetic instability plays a central role in the development and progression of human cancer. Two major classes of genetic instability, microsatellite instability (MSI) and chromosome instability (microsatellite stable; MSS), are best understood in the context of colon cancer, where MSI tumors represent ∼15% of cases, and compared with MSS tumors, more often arise in the proximal colon and display favorable clinical outcome. To further explore molecular differences, we profiled gene expression in a set of 18 colon cancer cell lines using cDNA microarrays representing ∼21,000 different genes. Supervised analysis identified a robust expression signature distinguishing MSI and MSS samples. As few as eight genes predicted with high accuracy the underlying genetic instability in the original and in three independent sample sets, comprising 13 colon cancer cell lines, 61 colorectal tumors, and 87 gastric tumors. Notably, the MSI signature was retained despite genetically correcting the underlying instability, suggesting the signature reflects a legacy of the tumor having arisen from MSI, rather than sensing the ongoing state of MSI. Our findings support a model in which MSI and MSS preferentially target different genes and pathways in cancer. Further, among the MSI signature genes, our findings implicate a role of elevated metallothionein expression in the clinical behavior of MSI cancers.

Supplementary Figure 2 from Genomic Profiling Reveals Alternative Genetic Pathways of Prostate Tumorigenesis

Ameloblastoma (AB) is an odontogenic tumor that arises from ameloblast-lineage cells. Although relatively uncommon and rarely metastatic, AB tumors are locally invasive and destructive to the jawbone and surrounding structures. Standard-of-care surgical resection often leads to disfigurement, and many tumors will locally recur, necessitating increasingly challenging surgeries. Recent genomic studies of AB have uncovered oncogenic driver mutations, including in the mitogen-activated protein kinase (MAPK) and Hedgehog signaling pathways. Medical therapies targeting those drivers would be a highly desirable alternative or addition to surgery; however, a paucity of existing AB cell lines has stymied clinical translation. To bridge this gap, here we report the establishment of 6 new AB cell lines—generated by “conditional reprogramming”—and their genomic characterization that reveals driver mutations in FGFR2, KRAS, NRAS, BRAF, PIK3CA, and SMO. Furthermore, in proof-of-principle studies, we use the new cell lines to investigate AB oncogene dependency and drug sensitivity. Among our findings, AB cells with KRAS or NRAS mutation (MAPK pathway) are exquisitely sensitive to MEK inhibition, which propels ameloblast differentiation. AB cells with activating SMO-L412F mutation (Hedgehog pathway) are insensitive to vismodegib; however, a distinct small-molecule SMO inhibitor, BMS-833923, significantly reduces both downstream Hedgehog signaling and tumor cell viability. The novel cell line resource enables preclinical studies and promises to speed the translation of new molecularly targeted therapies for the management of ameloblastoma and related odontogenic neoplasms.

Aberrant expression of Ecotropic Viral Integration Site 1 (EVI1) is a hallmark of acute myeloid leukemia (AML) with inv(3) or t(3;3), which is a disease subtype with especially poor outcome. In studying transcriptomes from AML patients with chromosome 3q rearrangements, we identified a significant upregulation of the Nuclear Receptor Interacting Protein 1 (NRIP1) as well as its adjacent non-coding RNA LOC101927745. Utilizing transcriptomic and epigenomic data from over 900 primary samples from patients as well as genetic and transcriptional engineering approaches, we have identified several mechanisms that can lead to upregulation of NRIP1 in AML. We hypothesize that the LOC101927745 transcription start site harbors a context-dependent enhancer that is bound by EVI1, causing upregulation of NRIP1 in AML with chromosome 3 abnormalities. Furthermore, we showed that NRIP1 knockdown negatively affects the proliferation and survival of 3qrearranged AML cells and increases their sensitivity to all-trans retinoic acid, suggesting that NRIP1 is relevant for the pathogenesis of inv(3)/t(3;3) AML and could serve as a novel therapeutic target in myeloid malignancies with 3q abnormalities.

Odontogenic tumors show considerable morphologic heterogeneity and at times the diagnosis can be challenging. Ameloblastoma, the most common odontogenic tumor, can have morphologic similarity to some salivary gland tumors and therefore we sought to identify biomarkers that might aid in the diagnosis by performing transcriptome wide gene expression profiling of 80 odontogenic and salivary gland neoplasms. These data identified the FOXP1/SOX10 expression profile as characteristic of many odontogenic tumors including ameloblastoma but largely absent in salivary gland tumors. We then assessed 173 salivary gland tumors and 108 odontogenic tumors by immunohistochemistry for FOXP1 and SOX10 expression and found that 34/35 (97%) cases of ameloblastomas were diffusely positive for FOXP1 but completely negative for SOX10. None of the basaloid salivary neoplasms (basal cell adenoma, adenoid cystic carcinoma, polymorphous adenocarcinoma, and myoepitheloma) demonstrated FOXP1/SOX10 expression pattern. Taken together, the results of this study suggest that the FOXP1/SOX10 immunophenotype is common in odontogenic tumors including ameloblastoma and might be useful distinguishing these from similar appearing basaloid salivary gland tumors.

This chapter discusses cancer genomics, which is one of the fastest-moving areas of medical research and is having a direct impact on people's lives. Cancer is a disease in which cells divide in excess, generating a lump, known as the primary tumour. A key feature of cancer is that the cells in the lump spread, invading the neighbouring normal tissues and blood and lymphatic vessels, allowing them to colonize distant organs, forming distant secondary tumours. Both primary and secondary tumours may cause symptoms as they penetrate and grow into normal tissues. The genome changes in cancers include single nucleotide changes, amplifications or deletions of regions of chromosomes, and chromosome rearrangements that may join genes together. The chapter considers how understanding the genome of cancer cells can help us prevent and treat cancer, and improve the survival and quality of life of patients.