Oncogenesis

Pancreatic ductal adenocarcinoma (PDAC) frequently metastasizes to the liver, which drives patient mortality. CA19-9 is elevated in most PDAC tumors and is widely used as a clinical biomarker. Elevated serum levels are associated with poor outcomes. However, whether CA19-9 functionally contributes to metastatic progression has not been fully defined, in part because mice lack endogenous CA19-9 expression. Here, using syngeneic murine PDAC cells engineered to express CA19-9, we investigated its functional role in liver metastasis. In splenic injection models, CA19-9 expression markedly increased liver metastatic burden by promoting both metastatic seeding and subsequent metastatic outgrowth. In vitro, CA19-9 enhanced tumor cell adhesion to endothelial cells through interaction with E-selectin. Metastatic seeding of CA19-9-expressing cells was reduced by genetic deletion of E-selectin or antibody neutralization of either CA19-9 or E-selectin in vivo. Therapeutic targeting of CA19-9 with a neutralizing antibody markedly reduced liver metastatic burden after metastatic seeding. CA19-9 expression increased AKT signaling in PDAC cells and liver metastases, and CA19-9 levels correlated with AKT activation in human PDAC tissues. These findings show that CA19-9 promotes PDAC liver metastasis through E-selectin-dependent metastatic seeding and AKT-associated metastatic outgrowth, highlighting CA19-9 as a functional mediator of PDAC metastasis and a potential therapeutic target.

PurposeProgastrin, aberrantly expressed in colorectal cancer (CRC), is an established trophic factor for tumour epithelial cells. Whether it also promotes CRC progression by reprogramming stromal fibroblasts remains unclear. We investigated progastrin-induced colonic fibroblast activation and its functional consequences on CRC cell migration. MethodsFibroblast activation was assessed in the colonic mucosa of hGAS mice and in the human normal colonic fibroblast line CCD18Co exposed to synthetic progastrin. The impact of tumour-derived progastrin on epithelial cell motility was analysed using HCT116 cells expressing a control shRNA (shLuc) or a progastrin-targeting shRNA (shPG) in transwell migration assays performed with or without fibroblasts. Candidate paracrine mediators were evaluated by RT-qPCR, ELISA and neutralization experiments, and signalling was interrogated using the PI3K inhibitor LY294002. ResultsColonic fibroblasts from hGAS mice displayed stromal FAP and SMA expression, indicating fibroblast activation in vivo. In CCD18Co cells, progastrin increased FAP and SMA protein levels. Fibroblasts enhanced HCT116 cell migration. This effect was stronger when tumour cells expressed progastrin or when fibroblasts were preconditioned by progastrin-producing HCT116 cells. Progastrin induced CXCL12/SDF-1 and CXCL8/IL-8 expression and secretion by fibroblasts, and neutralization of either chemokine abrogated the additional migratory effect conferred by progastrin-activated fibroblasts. Progastrin triggered sustained Akt phosphorylation in fibroblasts, while PI3K inhibition suppressed CXCL12 and CXCL8 secretion and abolished fibroblast-dependent tumour cell migration. ConclusionThese data identify a stromal dimension of progastrin signalling in CRC and support a model in which tumour-derived progastrin activates colonic fibroblasts and elicits a PI3K/Akt-dependent paracrine programme that enhances CRC cell migration.

BackgroundFibrosis and tumor innervation are two features of the tumor microenvironment (TME) that contribute directly to the lethality of pancreatic ductal adenocarcinoma (PDAC), but their potential interactions have not been explored. Moreover, although it is known that activated Schwann cells (SCs) stimulate cancer cell invasion, it remains unclear how SCs are activated. ObjectiveWe determined how SCs are activated in the pancreatic fibrotic microenvironment. DesignThe correlation between physical features of the microenvironment and SC activation was assessed in human patient samples and in mice by SC c-Jun phosphorylation monitoring, atomic force microscopy and multiphoton live imaging. Several in vitro models in which forces were applied to SCs expressing a reporter for c-Jun phosphorylation and RNA-Seq analysis were used to decipher the cellular and molecular mechanisms of SC activation. ResultsNerves surrounded by stiff stroma present higher SC activation. Intravital imaging shows a matrix dependent SC activation. Mechanical forces on SCs induce c-Jun phosphorylation in SCs in a non-canonical manner that involves a nuclear sensing machinery with the proinflammatory enzyme Phospholipase A2. ConclusionFibrosis enhances the protumorigenic impact of innervation by activating SCs via a mechanism in which nuclear compression triggers non-canonical activation of the AP-1 transcription factor complex. Pancreatic fibrosis alone, without cancer cells, is sufficient to activate SCs, suggesting this mechanism may be common across non-malignant pancreatic diseases. Notably, SCs are more sensitive to mechanical activation than PDAC cells. These findings reveal TME interactions that may guide future microenvironment-targeted PDAC therapies. What is already known on this topicThe pancreatic cancer tumor microenvironment is highly innervated and fibrotic, two components of the tumor microenvironment that regulate tumorigenesis. How they impact each other is unknown. Schwann cells have emerged as a significant protumorigenic player, but the triggers of Schwann cell activation remain undefined. What this study addsWe establish that fibrosis induces Schwann cell activation and characterize the mechanism by which it occurs. We uncovered a mechanical mode of action that deforms nuclear membrane and activates c-Jun in Schwann cells, which contradicts the traditional view of c-Jun activation through a stimulus detected at the plasma membrane. How this study might affect research, practice or policyThis study provides a better understanding of the biology of pancreatic ductal adenocarcinoma and supports the development of novel precision therapies that target the fibrotic microenvironment to impact the protumorigenic effect of tumor innervation.

BackgroundIn RAS-mutant tumors, ERK phosphorylates the mitochondrial fission GTPase DRP1 to promote mitochondrial fission. DRP1 activity is tumor-promoting in pancreatic and other RAS-driven cancers, but its role in therapeutic resistance is unknown. MethodsWe developed a panel of patient-derived pancreatic cancer cell lines resistant to the MEK inhibitor trametinib. We used immunofluorescence imaging, in vitro growth assays and orthotopic xenografts to determine the role of DRP1 in trametinib resistance. ResultsWe find that trametinib-resistant cells exhibit increased expression and phosphorylation of DRP1 compared to sensitive counterparts. Quantitative analysis of mitochondrial structure reveals that mitochondria in resistant cells are morphologically distinct and relatively smaller than sensitive cells treated with trametinib. Genetic and pharmacological inhibition of both c-Myc and CDK6 are sufficient to block DRP1 phosphorylation in resistant cells, suggesting that activation of a c-Myc-CDK6 signaling axis drives reactivation of mitochondrial fission in the absence of MAPK signaling. Importantly, deletion of DRP1 leads to either growth inhibition or re-sensitization to trametinib in resistant lines. ConclusionThese findings suggest DRP1 contributes to drug resistance, and that inhibition of mitochondrial fission might be a promising therapeutic strategy to combat resistance to MAPK and RAS inhibitors.

In the tumor microenvironment (TME), dynamic interactions between cells and soluble factors promote tumor progression. We previously demonstrated that parathyroid hormone-related peptide (PTHrP), a TME-associated cytokine, enhances the aggressive phenotype of HCT116 colorectal cancer (CRC) cells, and that conditioned medium from PTHrP-treated HMEC-1 endothelial stromal cells (CM) induces epithelial-to-mesenchymal transition (EMT) in CRC cells. Here, Western blot analysis showed that CM modulates Met receptor expression and activation and promotes cancer stem cell (CSC) traits in HCT116 cells. Since PTHrP induces CPT-11 chemoresistance through Met signaling, we investigated the involvement of the CM-Met axis in this process. Viability assays revealed that CM increases cell number and confers CPT11 resistance through Met activation. Transforming growth factor beta 1 (TGF{beta}1), upregulated in PTHrP-treated HMEC-1 cells, was evaluated as a potential mediator. Its neutralization reversed the CM-induced increase in cell number but did not affect chemoresistance. In silico analyses revealed differences between CRC and normal tissues related to TGF{beta}1 signaling and Met activation, along with positive correlations among the analyzed markers. Immunohistochemical observation of human samples is consistent with our previous findings. Overall, these findings support a role for PTHrP in promoting CRC aggressiveness through coordinated effects on tumor and stromal compartments

PurposeGlasdegib is a Sonic Hedgehog (SHH) pathway inhibitor used for treating newly diagnosed acute myeloid leukemia in elders or patients unfit for intensive chemotherapy. This study sought to demonstrate growth inhibition and increased apoptosis of B-cell acute lymphoblastic leukemia (B-ALL) in vitro under glasdegib, alone and combined with inotuzumab, using a novel co-culture system and validated chemosensitivity testing model to determine whether glasdegib with and without inotuzumab may represent a promising treatment strategy in B-ALL. MethodsSeven blood and marrow samples from B-ALL patients were co-cultured with HS-5 stromal cells in a co-culturing system designed to mimic the tumor microenvironment to maintain B-ALL cell viability for chemosensitivity testing under glasdegib and inotuzumab. ResultsCo-culturing improved B-ALL viability from four to nine days. Dosage-dependent responses to glasdegib were consistent among B-ALL samples on day four based on culture viability, and varied based on expressions of SSH genes GLI1, GLI3, SMO, and PTCH1. Combination with inotuzumab had varied effects on treatment response. ConclusionCo-culturing B-ALL cells with HS-5 stromal cells improves B-ALL growth and viability. Glasdegib with and without inotuzumab treatments impact the viability of co-cultured B-ALL cells by day four. SHH gene expressions suggest different B-ALL patients may be sensitive or resistant to glasdegib and inotuzumab.

Nutrient availability is a critical environmental factor that influences the metabolism and adaptability of cancer cells, including acute lymphoblastic leukaemia (ALL) cells, prone to relapse in the central nervous system (CNS). Currently available cell culture media contain supraphysiological nutrient levels and do not represent the restricted metabolic environment of CNS-ALL which resides in the leptomeninges surrounded by cerebrospinal fluid (CSF). Therefore, we formulated a novel physiological CSF-like cell culture medium (CSFmax) that recapitulates the unique metabolite composition of the CSF. Through in vitro and in vivo metabolic and functional studies, we demonstrate that ALL cells cultured in CSFmax rewire their metabolism, closely mimicking the metabolic phenotype of CNS-ALL, including their metabolic activity and redox state. Utilising CSFmax, in comparison to conventional nutrient-rich culture media, we identified an essential role for autophagy in ALL adaptation to the CNS niche. This was evident by increased autophagic activity and selective sensitisation of ALL cells to pharmacological inhibition of autophagy and genetic knockout of Unc-51 Like Autophagy Activating Kinase 1 (ULK1) or autophagy related 7 (ATG7). Importantly, using a robust preclinical in vivo model, mice xenografted with ULK1 and ATG7 deficient ALL cells exhibited reduced CNS disease burden when compared to mice xenografted with control cells. Overall, our findings provide strong evidence that physiological CSFmax is superior to current in vitro culture systems in recapitulating the metabolic signature of CNS resident ALL cells. By exploiting this system, we revealed for the first time autophagy as a targetable therapeutic vulnerability in CNS-ALL. Key PointsO_LICulturing ALL cells in bespoke CSF-like medium (CSFmax) recapitulates the metabolic adaptation of ALL cells in the CNS niche C_LIO_LIAutophagy is critical for metabolic adaptation and survival of CNS resident ALL cells C_LI

Breast cancer is the most common malignancy in women, with triple-negative breast cancer (TNBC) representing the most aggressive subtype and carrying a poor metastatic prognosis. Metastasis requires tumor cells to cross the endothelial barrier, a process facilitated by tumor-derived extracellular vesicles (EVs), which can disrupt vascular integrity. Fluid shear stress (FSS), generated by blood flow, shapes endothelial physiology and may influence EV uptake, yet the mechanisms underlying TNBC-derived small EV (sEV) internalization remain unclear. Here, we investigated TNBC sEV-endothelial interactions using combined in silico and in vitro approaches. Human umbilical vein endothelial cells (HUVECs) were cultured under static or FSS conditions (20 dyn/cm{superscript 2}), followed by proteomic profiling and protein-protein interaction analyses with sEV proteomes. Uptake assays employed pharmacological inhibition (Dynasore, M{beta}CD, Pitstop2), Caveolin-1 (CAV-1) and Clathrin Heavy Chain (CLHC), siRNA-mediated knockdown, and junctional interaction analyses via confocal microscopy and co-immunoprecipitation. FSS downregulated proliferation- and angiogenesis-associated proteins while upregulating adhesion and cytoskeletal regulators assessed by proteomics. Network analysis identified clathrin- and caveolin-mediated endocytosis (CME and CavME), integrins, and early endosomes as central mediators of sEV uptake. Functionally, uptake was reduced by Pitstop2, M{beta}CD, and CAV-1/CLHC knockdown under static conditions, but silencing paradoxically enhanced uptake under FSS, suggesting compensatory flow-dependent pathways. Notably, under FSS, sEVs accumulated at endothelial junctions, colocalizing with VE-CAD and associating with CLDN5, indicating a potential disruption mechanism of adherens and tight junctions and consequent endothelial permeability. These findings identify CME and CavME as key uptake routes while underscoring FSS as a critical determinant of endothelial-tumor EV interactions. By revealing junctional targeting of sEVs, this work provides new mechanistic insight into vascular remodeling during metastasis and highlights EV pathways as potential therapeutic targets in TNBC. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/721946v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@f91c5org.highwire.dtl.DTLVardef@2b4dc8org.highwire.dtl.DTLVardef@ff94f1org.highwire.dtl.DTLVardef@18b714b_HPS_FORMAT_FIGEXP M_FIG C_FIG Uptake and localization of sEVs on HUVEC under (a) static and (b) fluid shear-stress conditions. sEVs: Small Extracellular Vesicles. CME: Clathrin-mediated Endocytosis. CavME: Caveolin-mediated Endocytosis. CLDN5: Claudin-5. VE-CAD: Vascular Endothelial Cadherin. FSS: Fluid shear-stress.

Withdrawal StatementThe authors have withdrawn this manuscript to address issues related to data-use permission and authorship review. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

Prostate cancer is a common cancer in males and there is an urgent unmet clinical need to identify new therapies for advanced disease. Aberrant glycosylation is common in prostate cancer and plays a functional role in disease progression. The sialyl-Tn antigen (sTn) has been widely studied in cancer, yet its involvement in prostate cancer remains relatively unexplored. Here, we utilise a novel anti-sTn antibody (L2A5) to comprehensively monitor sTn expression levels in clinical prostate cancer tissues encompassing normal, benign, primary, metastatic castrate-resistant prostate cancer (CRPC), and patient-derived xenografts (PDXs). We show that while sTn is detected at low or negligible levels in normal prostate tissues, it is expressed in 44% of prostate tumours, and prostate cancer patients with high sTn levels have significantly poorer survival times. Analysis of metastatic therapy resistant prostate-derived tumours growing in liver and bone, shows sTn is expressed in 37.5% of cases. Furthermore, we show sTn is expressed in nearly half of PDXs tested, supporting the use of PDX models as tools for testing anti-sTn therapeutic strategies. These findings identify sTn as potential prognostic biomarker and therapeutic target in prostate cancer and lay the groundwork for the development of sTn-targeted precision therapies for advanced disease.

Chronic lymphocytic leukemia (CLL) is a lymphoid neoplasm with very heterogeneous clinical and biological behavior. Among molecular variables, TP53 alterations are well-established adverse prognostic markers; however, MYC activation, which has been linked to disease progression, has not been completely defined in terms of clinical and biological impact, particularly in relation to TP53 status. Here, we investigated the effects of MYC overexpression according to TP53 status using clinical and transcriptomic data from CLL patients and novel cellular models. CLL patients with TP53WT and MYC overexpression exhibited significantly shorter time to first treatment and overall survival, indicating an aggressive disease course comparable to that of patients with TP53 alterations. Consistently, MYC overexpression in in vitro TP53WTmodels was associated with increased proliferation, enrichment of AKT/mTOR signaling and upregulation of genes involved in leukemogenesis and tumor progression such as FOXO6. Moreover, MYC overexpression was associated with increased sensitivity to venetoclax in TP53WT cells. By contrast, the concurrence of MYC overexpression and TP53 dysfunction conferred resistance to conventional CLL therapies such as BCL2 or BTK inhibitors. Of note, we identified a glycolysis inhibitor, in monotherapy or combined with BKT inhibitors, as a potential therapeutic strategy for CLL patients harboring MYC overexpression and TP53 alterations.

Cancer metabolism rewiring is one of the hallmarks of cancer, enabling cancer cell survival in a nutrient deprived microenvironment. Key to this is nutrient scavenging where cancer cells rely on extracellular proteins, including extracellular matrix (ECM) components, to sustain their proliferation. ECM uptake is mediated by 2{beta}1 integrin, however it is not clear how this process is controlled by nutrient availability. Here we demonstrated that amino acid starvation promoted ECM internalisation, by inducing the expression of 2 integrin. Mechanistically, starvation-driven RAS/MAPK pathway activation in cells harbouring oncogenic RAS mutations and mTOR inhibition increased 2 integrin, while the GCN2-depedent integrated stress response was not required. Functionally, elevated 2 integrin levels promoted cell adhesion and migration in nutrient starved cells. Finally, 2 integrin was found upregulated in pancreatic tumours and correlated with poor prognosis in pancreatic adenocarcinoma patients. Together, these data indicate that the nutrient- starved pancreatic cancer microenvironment synergises with KRAS mutation to drive pancreatic cancer aggressiveness.

The PRESERVE trial (NCT04972097) is a prospective, single-arm pivotal IDE study evaluating focal irreversible electroporation (IRE) using the NanoKnife System for intermediate-risk prostate cancer. Men with Gleason Grade Group 2-3 disease underwent focal IRE and were followed for durability of oncologic control and safety. At 24 months, 68 patients completed follow-up with no new treatment failures identified. PSA levels were below baseline in 97% of patients, and one clinically triggered biopsy was negative for cancer. No new device- or procedure-related adverse events occurred beyond 12 months. These findings demonstrate durable efficacy and sustained safety of focal IRE.

Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer and carries the poorest prognosis among all cancers, largely because it is frequently diagnosed at metastatic stages. It is therefore critical to identify reliable markers of preinvasive stages and to decipher the network driving preinvasive lesions to invasive carcinoma. Here, we generated a zebrafish model in which KRASG12D is specifically expressed in pancreatic acinar cells, inducing acinar-to-ductal metaplasia that faithfully mirrors mammalian tumorigenesis. Single cell RNA-seq allowed us to capture transcriptional changes occurring at early stages of the disease. Cross-species comparison with mouse and human scRNAseq transcriptomes revealed a striking conservation of the genes upregulated during metaplasia, triggering common signalling pathways and regulatory programs. Notably, metaplastic cells reactivate a broad set of developmental genes expressed in multipotent pancreatic progenitors. Mapping the acinar-to-cancer trajectories revealed a set of cytoskeletal and migration-related genes specifically upregulated during the late phase of metaplasia, immediately prior to malignant transformation, likely conferring invasive potential to these cells. SCENIC analysis further identified regulatory networks that become progressively activated as cells transition toward cancer, suggesting their involvement in the acquisition of malignant traits. In conclusion, our cross-species comparison demonstrates a high degree of conservation in the molecular mechanisms driving pancreatic cancer progression from early to late stages across evolutionarily distant species, including zebrafish, mouse, and human, highlighting critical pathways that should be targeted to prevent cancer progression. To allow researchers to easily explore gene expression profiles during pancreatic cancer progression across all three species, the datasets are publicly accessible via a user-friendly web platform (https://www.zddm.page.gd/)

Suppressor of cytokine signaling 1 (SOCS1) negative regulates inflammatory cytokine production and attenuates oncogenic growth factor signaling pathways. Reduced SOCS1 protein expression in human prostate cancer correlates with greater disease severity. To define the physiological functions of SOCS1 functions in the prostate, we conditionally ablated Socs1 in prostate epithelial cells of C57BL/6 mice. These Socs1{Delta}PE mice exhibited normal prostate development, maturation and lobular architecture. However, adult Socs1{Delta}PEmice developed progressive epithelial hyperplasia and inflammatory cell infiltration that were temporally and spatially distinct. SOCS1-deficient prostate showed increased epithelial cell proliferation and elevated oxidative stress markers, and prostate organoids recapitulated this hyperplasia phenotype. Diet-induced obesity exacerbated both hyperplasia and inflammation in SOCS1-deficient prostate. Upon transurethral infection with uropathogenic Escherichia coli UPEC1677 expressing the genotoxin colibactin, Socs1{Delta}PE mice developed invasive prostate cancer with complete loss of lobular architecture, whereas control mice developed hyperplasia and pre-neoplastic lesions. In vitro, SOCS1-deficient prostate organoid-derived epithelial cells exhibited increased DNA damage following exposure to UPEC1677. Deletion of the colibactin biosynthetic gene clbP in UPEC1677 abolished its ability to induce DNA damage in SOCS1-deficient cells and to drive prostate cancer in vivo. Proteomic analysis of prostate organoids revealed dysregulation of basal and luminal epithelial lineage markers and signaling pathway proteins that could promote neoplasia in SOCS1-deficient cells. Collectively, these findings establish an essential, epithelial cell-intrinsic role for SOCS1 in maintaining prostate tissue homeostasis by restraining proliferation, regulating lineage plasticity, limiting inflammation and oxidative stress, and conferring protection against genotoxic injury and neoplastic transformation.

Background: Modern therapy for childhood and adolescent leukemia requires accurate risk classification of genomic subtype. Although short-read next-generation sequencing (NGS)- based approaches provide comprehensive clinical diagnostics in limited, highly resourced settings, they remain expensive, slow, and inaccessible to most children worldwide. Transformative approaches are needed to improve diagnostic classification for leukemia globally. Methods: We simultaneously continued to develop an analytical pipeline NASVar (Nanopore variant calling for adaptive sampling), and conducted a multicenter, type-two hybrid clinical validation study of an Oxford Nanopore Technologies (ONT) adaptive-sampling whole-genome sequencing (asWGS) assay across hospitals with varying diagnostic resources. In preparation for implementation, a global panel developed a leukemia-based standardized gene set and consensus laboratory-developed test (LDT) validation guidelines. Measures of assay effectiveness compared to both conventional and orthogonal NGS methods, where available, were simultaneously collected with data to measure the implementation outcomes of feasibility, fidelity, appropriateness, and cost. Results: All four centers successfully completed the LDT validation, with minimal adaptations required for regulatory compliance. A total of 457 specimens were sequenced (331 B-ALL, 83 AML, 43 T-ALL). For the 210 B-ALL cases with locally resolved genomic subtypes defined by DNA alterations, asWGS was 100% concordant (210/210). Cases locally defined as B-other were resolved via asWGS with disease-defining DNA alterations in 47% (49/105) of cases. An additional 41% (43/105) of locally defined B-other cases were classified by incorporation of DNA methylation, and all 16 B-ALL patient-derived xenograft controls were correct, for a total of 96% (318/331) of all B-ALL cases in the cohort resolved with single assay asWGS. For AML, 97% (56/58) of cases with locally resolved genomic subtypes were identified by automated asWGS analysis, while an additional two cases were identified after targeted manual review. At Indus Hospital in Pakistan, the B-ALL and AML diagnostic genomic subtype yield increased from 28% with local standard of care diagnostic testing, to 84% with asWGS. The cost of reagents and consumables in the United States, assuming pooled three-plexing, was $343/sample. Based on the combined hybrid validation results, all centers are independently preparing for clinical return of results. Conclusions: ONT asWGS was successfully validated as a clinical assay in four diverse hospital settings. As a single, multi-omic platform that delivers value across the continuum of high-resource to resource-limited contexts, the approach offers a disruptive solution to address the global equity gap in cancer diagnostics.

Multiple myeloma remains a fatal, incurable disease. Most therapies are targeted to the cancer cell or T cell engagement. Little is known about the supporting myeloma microenvironment and its contribution to tumor fitness. Here, we expand upon the observation of human mast cells in the NSG-hIL6 myeloma patient derived xenograft mouse model to show mast cells decrease time to engraftment, promote increased myeloma engraftment and cause myeloma bone disease. We identify 10 mast cell secreted factors that together improve the survival of patient myeloma cells in vitro. Our results highlight the versatility of the NSG-hIL6 model to study microenvironmental interactions between human bone marrow cells and myeloma and confirm prior suggestions that clinical signs of disease, such as osteolytic lesions, may at least partially be related to non-malignant bone marrow microenvironmental cells, such as mast cells.

Few studies with pre-diagnostic samples have estimated associations between circulating metabolites and risk of advanced prostate cancer. We performed untargeted metabolomic profiling of pre-diagnostic blood samples from 212 advanced prostate cancer cases (stage [&ge;]T3b or lethal during follow-up) and 212 matched controls from the Health Professionals Follow-up Study. 243 metabolites were assayed using liquid chromatography-tandem mass spectrometry (Broad Institute) and met quality control standards. We used multivariable conditional logistic regression to generate odds ratios (OR) and 95% confidence intervals (95%CI) for associations between individual metabolites and risk of advanced prostate cancer, and conducted metabolite set enrichment tests to identify metabolite classes enriched in advanced prostate cancer. Subgroup analyses were conducted by body mass index (BMI) and time between blood draw and diagnosis. Levels of 16 lipid species were nominally associated with advanced prostate cancer at p<0.05, though none were statistically significant after multiple testing correction. The strongest signals were for C56:1 triacylglycerol (TAG; OR: 1.34, 95%CI: 1.07-1.67) and C38:4 diacylglycerol (DAG; OR: 1.27, 95%CI: 1.04-1.55). Enrichment analyses revealed six metabolite classes associated with advanced prostate cancer after multiple testing adjustment, the top four of which were DAGs and TAGs: DAGs overall (P=3.4E-07), unsaturated DAGs (P=5.9E-07), unsaturated TAGs (P=2.3E-06), and TAGs overall (P=2.4E-06). 43 metabolites were nominally associated with advanced prostate cancer among individuals with BMI <25 kg/m2; only three demonstrated nominal associations in individuals with BMI [&ge;]25 kg/m2. These findings suggest associations between circulating pre-diagnostic lipid levels and aggressive prostate cancer risk, particularly in lean individuals.

BackgroundMesothelioma (Me) is an aggressive cancer with limited response to conventional therapies. The tumors harsh microenvironment contributes to immune escape and therapy resistance and the effects of ICIs on Me are still unclear. Adenosine, an immunosuppressive molecule produced from AMP by the enzyme CD73, accumulates in hypoxic tumor areas. Elevated CD73 and adenosine receptor A2B (A2Br) levels on Me cells are linked to worse patient outcomes, indicating their important role in disease progression and potential as targets for treatment. AimThis study characterizes the Me-ME (micro environment) and evaluates the efficacy of TT-4 (A2B inibitor) and AB680 (CD73 inibitor), alone or with aPD-1, using 3D models in vitro and in vivo. MethodsCD73 and A2B receptor levels were quantified in tumor and normal samples using qRT-PCR and IHC. Cells lines were treated with CoCl2 to mimic hypoxia, then CD73, A2Br and related markers were analyzed. MSTO-211H and REN cells were silenced for CD73, grown as spheroids and adenosine release was measured. Co-culture spheroids of MSTO-211H and Jurkat cells were treated with AMP and CD73 inhibitor, then analyzed for viability and immune markers. An orthotopic Me model was established by injecting AB1-B/c-LUC cells and monitored by in vivo imaging. Proteomic analysis of spheroids was conducted to identify proteins and pathways involved. ResultsHypoxia boosts CD73 and A2Br expression in Me cells, leading to adenosine production via CD73. In 3D co-cultures, AB680 lowered Me cell viability and enhanced activation of Jurkat T cells. In mice, combining aPD-1 therapy with A2Br or CD73 inhibitors strongly reduced tumor growth. Proteomics identified 93 proteins influenced by adenosine signaling through A2B. ConclusionTargeting the adenosine pathway alongside PD-1 blockade offers a promising new immunotherapy strategy for Me.

The formation of the premetastatic niche prepares distant tissues for tumor cell engraftment. Endothelial cells are critical mediators of premetastatic niche formation, orchestrating extravasation of circulating tumor cells and critical pro-tumor immune cells, such as neutrophils. In mouse models of breast cancer, we show that primary tumors upregulate the non-signaling chemokine receptor ACKR1 in the endothelium of the lung premetastatic niche. ACKR1-expressing venules were found to be preferential sites of neutrophil and tumor cell localization within lung tissue. A newly generated conditional ACKR1 allele was used to show that endothelial-specific removal of ACKR1 expression significantly reduces metastatic engraftment in the lung. When ACKR1 is activated by tumor-secreted factors, endothelial ACKR1 functions to promote neutrophil recruitment within the lung parenchyma. We conclude that ACKR1 is a critical component of the endothelial response to tumors at the metastatic site of the lung, leading to neutrophil recruitment and promotion of tumor cell metastasis. SUMMARYEndothelial cells play critical roles in breast cancer metastasis. ACKR1 is upregulated in the endothelium of the lung metastatic niche in response to primary mammary tumors. Endothelial ACKR1 expression was found to promote neutrophil infiltration into the metastatic niche and support breast tumor cell metastasis to the lung.