Explore the vast range of titles available.

Cribriform prostate cancer, found in both invasive cribriform carcinoma (ICC) and intraductal carcinoma (IDC), is an aggressive histological subtype that is associated with progression to lethal disease. To delineate the molecular and cellular underpinnings of ICC/IDC aggressiveness, this study examines paired ICC/IDC and benign prostate surgical samples by single-cell RNA-sequencing, TCR sequencing, and histology. ICC/IDC cancer cells express genes associated with metastasis and targets with potential for therapeutic intervention. Pathway analyses and ligand/receptor status model cellular interactions among ICC/IDC and the tumor microenvironment (TME) including JAG1/NOTCH. The ICC/IDC TME is hallmarked by increased angiogenesis and immunosuppressive fibroblasts ( CTHRC1 + ASPN + FAP + ENG + ) along with fewer T cells, elevated T cell dysfunction, and increased C1QB + TREM2 + APOE + -M2 macrophages. These findings support that cancer cell intrinsic pathways and a complex immunosuppressive TME contribute to the aggressive phenotype of ICC/IDC. These data highlight potential therapeutic opportunities to restore immune signaling in patients with ICC/IDC that may afford better outcomes. The molecular and cellular underpinnings of cribriform prostate cancer aggressiveness remain to be explored. Here, the authors perform single-cell RNA-sequencing, TCR sequencing and histology and reveal cancer cell intrinsic pathways and an immunosuppressive tumour microenvironment.

The energy that sustains cancer cells is derived preferentially from glycolysis. This metabolic change, the Warburg effect, was one of the first alterations in cancer cells recognized as conferring a survival advantage. Here, we show that p53, one of the most frequently mutated genes in cancers, modulates the balance between the utilization of respiratory and glycolytic pathways. We identify Synthesis of Cytochrome c Oxidase 2 (SCO2) as the downstream mediator of this effect in mice and human cancer cell lines. SCO2 is critical for regulating the cytochrome c oxidase (COX) complex, the major site of oxygen utilization in the eukaryotic cell. Disruption of the SCO2 gene in human cancer cells with wild-type p53 recapitulated the metabolic switch toward glycolysis that is exhibited by p53-deficient cells. That SCO2 couples p53 to mitochondrial respiration provides a possible explanation for the Warburg effect and offers new clues as to how p53 might affect aging and metabolism.

Fibrosis is an important feature of adipose tissue in obese individuals; nevertheless, roles of obesity-associated extracellular matrix (ECM) deposition in breast cancer progression largely remain elusive. Here, we show that expression of Hsp47, a chaperone protein involving collagen secretion, is induced in adipose tissue from obese humans and mice. Adipocyte-specific Hsp47 deletion (Adi-KO) suppresses the high-fat diet (HFD)-induced obesity and mammary tumor progression, accompanied by a reduction in ECM deposition. Matrisome analyses lead to the identification of asporin as a new target of Hsp47 in adipose tissue. Co-immunoprecipitation results confirm that the recruitment of Hsp47 enhances asporin secretion in adipocytes. We further show that knockout of asporin suppresses HFD-induced mammary tumor growth, while exogenous of asporin partially rescues tumor growth in the decellularized mammary gland derived from Hsp47 Adi-KO mice. These results indicate that asporin at least partially mediates Hsp47 function in HFD-associated tumor progression. Digital spatial profiling (DSP) analyses show that Hsp47 depletion significantly increases the accumulation of CD8 T cells in tumor and tumor-associated adipose tissues. These results implicate that Hsp47, along with-it mediated ECM deposition, suppresses the anti-tumor immunity under HFD conditions. These findings reveal Hsp47 as a novel target for mitigating obesity-associated breast cancer progression.

Background/purpose TrkA overexpression occurs in over 20% of breast cancers, including triple-negative breast cancers (TNBC), and has recently been recognized as a potential driver of carcinogenesis. Recent clinical trials of pan-Trk inhibitors have demonstrated targeted activity against tumors harboring NTRK fusions, a relatively rare alteration across human cancers. Despite this success, current clinical trials have not investigated TrkA overexpression as an additional therapeutic target for pan-Trk inhibitors. Here, we evaluate the cancerous phenotypes of TrkA overexpression relative to NTRK1 fusions in human cells and assess response to pharmacologic Trk inhibition. Experimental design/methods To evaluate the clinical utility of TrkA overexpression, a panel of TrkA overexpressing cells were developed via stable transfection of an NTRK1 vector into the non-tumorigenic breast cell lines, MCF10A and hTERT-IMEC. A panel of positive controls was generated via stable transfection with a CD74-NTRK1 fusion vector into MCF10A cells. Cells were assessed via various in vitro and in vivo analyses to determine the transformative potential and targetability of TrkA overexpression. Results TrkA overexpressing cells demonstrated transformative phenotypes similar to Trk fusions, indicating increased oncogenic potential. TrkA overexpressing cells demonstrated growth factor-independent proliferation, increased PI3Kinase and MAPKinase pathway activation, anchorage-independent growth, and increased migratory capacity. These phenotypes were abrogated by the addition of the pan-Trk inhibitor, larotrectinib. In vivo analysis demonstrated increased tumorgenicity and metastatic potential of TrkA overexpressing breast cancer cells. Conclusions Herein, we demonstrate TrkA overexpressing cells show increased tumorgenicity and are sensitive to pan-Trk inhibitors. These data suggest that TrkA overexpression may be an additional target for pan-Trk inhibitors and provide a targeted therapy for breast cancer patients.

BackgroundProstate cancer remains the second leading cause of cancer related death in men. Immune check point blocking antibodies have revolutionized treatment of multiple solid tumors, but results in prostate cancer remain marginal. Previous reports have suggested that local therapies, in particular cryoablation might increase tumor immunogenicity. In this work, we examine potential synergism between tumor cryoabalation and check point blocking antibodies.MethodsFVB/NJ mice were injected subcutaneously into each flank with either 1 × 106 or 0.2 × 106 isogenic hormone sensitive Myc-Cap cells to establish synchronous grafts. Mice were treated with four intraperitoneal injections of anti-PD-1 (10 mg/kg), anti-CTLA-4 (1 mg/kg), or isotype control antibody with or without adjuvant cryoablation of the larger tumor graft and with or without neo-adjuvant androgen deprivation with degarelix (ADT). Mouse survival and growth rates of tumor grafts were measured. The immune dependency of observed oncological effects was evaluated by T cell depletion experiments.ResultsTreatment with anti-CTLA-4 antibody and cryoablation delayed the growth of the distant tumor by 14.8 days (p = 0.0006) and decreased the mortality rate by factor of 4 (p = 0.0003) when compared to cryoablation alone. This synergy was found to be dependent on CD3+ and CD8+ cells. Combining PD-1 blockade with cryoablation did not show a benefit over use of either treatment alone. Addition of ADT to anti-PD1 therapy and cryoablation doubled the time to accelerated growth in the untreated tumors (p = 0.0021) and extended survival when compared to cryoablation combined with ADT in 25% of the mice. Effects of combining anti-PD1 with ADT and cryoablation on mouse survival were obviated by T cell depletion.ConclusionTrimodal therapy consisting of androgen deprivation, cryoablation and PD-1 blockade, as well as the combination of cryoablation and low dose anti-CTLA-4 blockade showed that local therapies with cryoablation could be considered to augment the effects of checkpoint blockade in prostate cancer.

A defining hallmark of primary and metastatic cancers is the migration and invasion of malignant cells. These invasive properties involve altered dynamics of the cytoskeleton and one of its major structural components β-actin. Here we identify AIM1 (absent in melanoma 1) as an actin-binding protein that suppresses pro-invasive properties in benign prostate epithelium. Depletion of AIM1 in prostate epithelial cells increases cytoskeletal remodeling, intracellular traction forces, cell migration and invasion, and anchorage-independent growth. In addition, decreased AIM1 expression results in increased metastatic dissemination in vivo. AIM1 strongly associates with the actin cytoskeleton in prostate epithelial cells in normal tissues, but not in prostate cancers. In addition to a mislocalization of AIM1 from the actin cytoskeleton in invasive cancers, advanced prostate cancers often harbor AIM1 deletion and reduced expression. These findings implicate AIM1 as a key suppressor of invasive phenotypes that becomes dysregulated in primary and metastatic prostate cancer. Invasion of malignant cells involves changes in cytoskeleton dynamics. Here the authors identify absent in melanoma 1 as an actin binding protein and show that it regulates cytoskeletal remodeling and cell migration in prostate epithelial cells, acting as a metastatic suppressor in cancer cells.

Tamoxifen is effective for treating estrogen receptor-alpha (ER) positive breast cancers. However, few molecular mediators of tamoxifen resistance have been elucidated. Here we describe a previously unidentified gene, MACROD2 that confers tamoxifen resistance and estrogen independent growth. We found MACROD2 is amplified and overexpressed in metastatic tamoxifen-resistant tumors. Transgene overexpression of MACROD2 in breast cancer cell lines results in tamoxifen resistance, whereas RNAi-mediated gene knock down reverses this phenotype. MACROD2 overexpression also leads to estrogen independent growth in xenograft assays. Mechanistically, MACROD2 increases p300 binding to estrogen response elements in a subset of ER regulated genes. Primary breast cancers and matched metastases demonstrate MACROD2 expression can change with disease evolution, and increased expression and amplification of MACROD2 in primary tumors is associated with worse overall survival. These studies establish MACROD2 as a key mediator of estrogen independent growth and tamoxifen resistance, as well as a potential novel target for diagnostics and therapy. Significance Despite the widespread use and success of tamoxifen for treating ER-positive breast cancers, overcoming resistance to this drug remains an unmet need in clinical breast oncology. The results presented in this study demonstrate that overexpression of a novel gene, MACROD2 , can mediate tamoxifen resistance and estrogen independent growth in human breast cancers, and that amplification of MACROD2 in primary breast tumors is associated with worse overall survival.

Abtract Clinical circulating cell-free DNA (cfDNA) testing is now routine, however test accuracy remains limited. By understanding the life-cycle of cfDNA, we might identify opportunities to increase test performance. Here, we profile cfDNA release across a 24-cell line panel and utilize a cell-free CRISPR screen (cfCRISPR) to identify mediators of cfDNA release. Our panel outlines two distinct groups of cell lines: one which releases cfDNA fragmented similarly to clinical samples and purported as characteristic of apoptosis, and another which releases larger fragments associated with vesicular or necrotic DNA. Our cfCRISPR screens reveal that genes mediating cfDNA release are primarily involved with apoptosis, but also identify other subsets of genes such as RNA binding proteins as potential regulators of cfDNA release. We observe that both groups of cells lines identified primarily produce cfDNA through apoptosis. These results establish the utility of cfCRISPR, genetically validate apoptosis as a major mediator of DNA release in vitro, and implicate ways to improve cfDNA assays. A novel approach using whole-genome CRISPR-Cas9 screen indicates that apoptosis is the most important mediator of cfDNA release.

The mechanism of how loss of the tumor suppressor p53 can lead to genomic instability is not fully understood. This study demonstrates that under physiologic low levels of proliferation, homozygous loss of tumor protein 53 ( TP53 ) via genome editing, but not common p53 missense mutations, results in an inability to increase expression of N-Myc down-regulated gene 1 ( NDRG1 ) . In turn, failure to upregulate NDRG1 protein under low proliferative states leads to supernumerary centrosome formation, a known mechanism of aneuploidy. These results provide a mechanistic link between loss of TP53 , proliferation, NDRG1 , and genomic instability and help explain how cells with a low proliferative index and p53 loss can acquire additional genetic alterations that lead to cancer. The tumor protein 53 ( TP53 ) tumor suppressor gene is the most frequently somatically altered gene in human cancers. Here we show expression of N-Myc down-regulated gene 1 ( NDRG1 ) is induced by p53 during physiologic low proliferative states, and mediates centrosome homeostasis, thus maintaining genome stability. When placed in physiologic low-proliferating conditions, human TP53 null cells fail to increase expression of NDRG1 compared with isogenic wild-type controls and TP53 R248W knockin cells. Overexpression and RNA interference studies demonstrate that NDRG1 regulates centrosome number and amplification. Mechanistically, NDRG1 physically associates with γ-tubulin, a key component of the centrosome, with reduced association in p53 null cells. Strikingly, TP53 homozygous loss was mutually exclusive of NDRG1 overexpression in over 96% of human cancers, supporting the broad applicability of these results. Our study elucidates a mechanism of how TP53 loss leads to abnormal centrosome numbers and genomic instability mediated by NDRG1 .

Cancer-associated fibroblasts (CAFs) are part of the tumor microenvironment (TME) that enable cancer cells to establish metastases, but the mechanisms of these interactions are not fully known. Herein, we identified a paracrine mechanism in which CAF-secreted asporin (ASPN) activated ErbB signaling and subsequent migration of adjacent prostate cancer cells. Our data support that ASPN bound directly to the ligand binding domain of human epidermal growth factor 3 (HER3) and induced HER2/HER3 heterodimerization and activation of the PI3K, MAPK, and calcium pathways. Genetic and therapeutic inhibition of HER2/HER3 ablated ASPN-induced signaling and migration. Clinically, ASPN was detected in the stroma of HER2/HER3-expressing human metastatic prostate cancer, supporting the clinical relevance of these findings and highlighting a potential therapeutic vulnerability. Antibody-drug conjugate (ADC) therapies designed to target HER2 (trastuzumab-deruxtecan) or HER3 (patritumab-deruxtecan) significantly diminished prostate cancer cell growth in vitro and tumor size in vivo, despite Aspn in the TME. Collectively, these findings indicate ASPN functions as a HER3 ligand to induce cellular migration, and inhibition with anti-HER2 or anti-HER3 ADC therapies highlights potential clinical utility for patients with metastatic castration-resistant prostate cancer that expresses HER2 or HER3.