Genetically engineered myeloid cells rebalance the core immune suppression program in metastasis.

Metastasis is the leading cause of cancer-related deaths, and greater knowledge of the metastatic microenvironment is necessary to effectively target this process. Microenvironmental changes occur at distant sites prior to clinically detectable metastatic disease; however, the key niche regulatory signals during metastatic progression remain poorly characterized. Here, we identify a core immune suppression gene signature in pre-metastatic niche formation that is expressed predominantly by myeloid cells. We target this immune suppression program by utilizing genetically engineered myeloid cells (GEMys) to deliver IL-12 to modulate the metastatic microenvironment. Our data demonstrate that IL12-GEMy treatment reverses immune suppression in the pre-metastatic niche by activating antigen presentation and T cell activation, resulting in reduced metastatic and primary tumor burden and improved survival of tumor-bearing mice. We demonstrate that IL12-GEMys can functionally modulate the core program of immune suppression in the pre-metastatic niche to successfully rebalance the dysregulated metastatic microenvironment in cancer.

Phosphoproteome Integration Reveals Patient-Specific Networks in Prostate Cancer.

We used clinical tissue from lethal metastatic castration-resistant prostate cancer (CRPC) patients obtained at rapid autopsy to evaluate diverse genomic, transcriptomic, and phosphoproteomic datasets for pathway analysis. Using Tied Diffusion through Interacting Events (TieDIE), we integrated differentially expressed master transcriptional regulators, functionally mutated genes, and differentially activated kinases in CRPC tissues to synthesize a robust signaling network consisting of druggable kinase pathways. Using MSigDB hallmark gene sets, six major signaling pathways with phosphorylation of several key residues were significantly enriched in CRPC tumors after incorporation of phosphoproteomic data. Individual autopsy profiles developed using these hallmarks revealed clinically relevant pathway information potentially suitable for patient stratification and targeted therapies in late stage prostate cancer. Here, we describe phosphorylation-based cancer hallmarks using integrated personalized signatures (pCHIPS) that shed light on the diversity of activated signaling pathways in metastatic CRPC while providing an integrative, pathway-based reference for drug prioritization in individual patients.

Massively parallel, computationally guided design of a proenzyme.

Confining the activity of a designed protein to a specific microenvironment would have broad-ranging applications, such as enabling cell type-specific therapeutic action by enzymes while avoiding off-target effects. While many natural enzymes are synthesized as inactive zymogens that can be activated by proteolysis, it has been challenging to redesign any chosen enzyme to be similarly stimulus responsive. Here, we develop a massively parallel computational design, screening, and next-generation sequencing-based approach for proenzyme design. For a model system, we employ carboxypeptidase G2 (CPG2), a clinically approved enzyme that has applications in both the treatment of cancer and controlling drug toxicity. Detailed kinetic characterization of the most effectively designed variants shows that they are inhibited by ∼80% compared to the unmodified protein, and their activity is fully restored following incubation with site-specific proteases. Introducing disulfide bonds between the pro- and catalytic domains based on the design models increases the degree of inhibition to 98% but decreases the degree of restoration of activity by proteolysis. A selected disulfide-containing proenzyme exhibits significantly lower activity relative to the fully activated enzyme when evaluated in cell culture. Structural and thermodynamic characterization provides detailed insights into the prodomain binding and inhibition mechanisms. The described methodology is general and could enable the design of a variety of proproteins with precise spatial regulation.

Gain-of-function mutant p53 activates small GTPase Rac1 through SUMOylation to promote tumor progression.

Tumor suppressor p53 is frequently mutated in human cancer. Mutant p53 often promotes tumor progression through gain-of-function (GOF) mechanisms. However, the mechanisms underlying mutant p53 GOF are not well understood. In this study, we found that mutant p53 activates small GTPase Rac1 as a critical mechanism for mutant p53 GOF to promote tumor progression. Mechanistically, mutant p53 interacts with Rac1 and inhibits its interaction with SUMO-specific protease 1 (SENP1), which in turn inhibits SENP1-mediated de-SUMOylation of Rac1 to activate Rac1. Targeting Rac1 signaling by RNAi, expression of the dominant-negative Rac1 (Rac1 DN), or the specific Rac1 inhibitor NSC23766 greatly inhibits mutant p53 GOF in promoting tumor growth and metastasis. Furthermore, mutant p53 expression is associated with enhanced Rac1 activity in clinical tumor samples. These results uncover a new mechanism for Rac1 activation in tumors and, most importantly, reveal that activation of Rac1 is an unidentified and critical mechanism for mutant p53 GOF in tumorigenesis, which could be targeted for therapy in tumors containing mutant p53.

Metabolic reprogramming ensures cancer cell survival despite oncogenic signaling blockade.

There is limited knowledge about the metabolic reprogramming induced by cancer therapies and how this contributes to therapeutic resistance. Here we show that although inhibition of PI3K-AKT-mTOR signaling markedly decreased glycolysis and restrained tumor growth, these signaling and metabolic restrictions triggered autophagy, which supplied the metabolites required for the maintenance of mitochondrial respiration and redox homeostasis. Specifically, we found that survival of cancer cells was critically dependent on phospholipase A2 (PLA2) to mobilize lysophospholipids and free fatty acids to sustain fatty acid oxidation and oxidative phosphorylation. Consistent with this, we observed significantly increased lipid droplets, with subsequent mobilization to mitochondria. These changes were abrogated in cells deficient for the essential autophagy gene ATG5 Accordingly, inhibition of PLA2 significantly decreased lipid droplets, decreased oxidative phosphorylation, and increased apoptosis. Together, these results describe how treatment-induced autophagy provides nutrients for cancer cell survival and identifies novel cotreatment strategies to override this survival advantage.

Initial Experience Using Laparoscopic HIPEC for Gastric Cancer with Peritoneal Metastasis: Safety and Outcomes.

BACKGROUND: Peritoneal metastases (PM) develop in approximately 20% of patients with gastric cancer (GC). For selected patients, treatment of PM with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results. This report aims to describe the safety and perioperative outcomes of laparoscopic HIPEC for GC/PM. METHODS: This retrospective cohort study evaluated patients who had GC and PM treated with laparoscopic HIPEC (2018-2022). The HIPEC involved cisplatin and mitomycin C (MMC) or MMC alone. The primary end point was perioperative safety. RESULTS: The 22 patients in this study underwent 27 procedures. The mean age was 58 ± 13 years. All the patients were Eastern Cooperative Oncology Group (ECOG) 0 or 1 (55 and 45%, respectively). Five patients underwent a second laparoscopic HIPEC, with a median of 126 days (interquartile range [IQR], 117-166 days) between procedures. The median peritoneal carcinomatosis index (PCI) was 4 (IQR, 2-9), and the median hospital stay was 2 days (IQR, 1-3 days). No 30-day readmissions or complications occurred. Eight patients (36%) underwent gastrectomy (CRS ± HIPEC). After an average follow-up period of 11 months, 7 (32%) of the 22 patients were alive. The median overall survival was 11 months (IQR, 195-739 days) from the initial procedure and 19.3 months (IQR, 431-1204 days) from the diagnosis. CONCLUSIONS: Laparoscopic HIPEC appears to be safe with minimal perioperative complications. Approximately one third of the patients undergoing initial laparoscopic HIPEC ultimately proceeded to cytoreduction and gastrectomy. Preliminary survival data from this highly selected cohort suggest that the addition of laparoscopic HIPEC to systemic chemotherapy does not compromise other treatment options. These initial results suggest that laparoscopic HIPEC may offer benefit to patients with GC and PM and aid in the selection of patients who may benefit from curative-intent resection.

Peritoneal metastases from primary appendiceal and colorectal carcinomas demonstrate distinct molecular identities on comprehensive tumor analysis.

BACKGROUND AND OBJECTIVES: Published data comparing peritoneal metastases from appendiceal cancers (pAC) and colorectal cancers (pCRC) remain sparse. We compared pAC and pCRC using comprehensive tumor profiling (CTP). METHODS: CTP was performed, including next-generation sequencing and analysis of copy number variation (CNV), microsatellite instability (MSI) and tumor mutational burden (TMB). RESULTS: One hundred thirty-six pAC and 348 pCRC samples underwent CTP. The cohorts' age and gender were similar. pCRC demonstrated increased pathogenic variants (PATHs) in APC (48% vs. 3%, p < 0.01), ARID1A (12% vs. 2%, p < 0.01), BRAF (12% vs. 2%, p < 0.01), FBXW7 (7% vs. 2%, p < 0.01), KRAS (52% vs. 41%, p < 0.05), PIK3CA (15% vs. 2%, p < 0.01), and TP53 (53% vs. 23%, p < 0.01), and decreased PATHs in GNAS (8% vs. 31%, p < 0.01). There was no difference in CNV, fusion rate, or MSI. Median TMB was higher in pCRC (5.8 vs. 5.0 mutations per megabase, p = 0.0007). Rates of TMB-high tumors were similar (pAC 2.1% vs. pCRC 9.0%, p = 0.1957). pCRC had significantly more TMB-high tumors at lower thresholds. CONCLUSIONS: Despite a reduced overall TMB, pAC demonstrated mutations distinct from those seen in pCRC. These may serve as discrete biomarkers for future study.

Segmental bile duct resection versus pancreatoduodenectomy for middle and distal third bile duct cancer. A systematic review and meta-analysis of comparative studies.

INTRODUCTION: Data regarding oncologic outcomes of segmental bile duct resection (SBDR) versus pancreatoduodenectomy (PD) for bile duct cancers (BDC) are conflicting. We compared SBDR and PD for BDC utilizing pooled data analysis. MATERIALS AND METHODS: A comprehensive PRISMA 2020 systematic review was performed. Studies comparing SBDR with PD for BDC were included. Pooled mean differences (MD), odds ratios (OR), and risk ratios (RR) with 95% confidence intervals (CI) were calculated. Subgroup analyses were performed. Study quality, bias, heterogeneity, and certainty were analyzed. RESULTS: Twelve studies from 2004 to 2021 were included, comprising 533 SBDR and 1,313 PD. SBDR was associated with positive proximal duct margins (OR 1.56; CI 1.11-2.18; P = .01), and distal duct margins (OR 43.25; CI 10.38-180.16; P < .01). SBDR yielded fewer lymph nodes (MD -6.93 nodes; CI -9.72-4.15; P < .01) and detected fewer nodal metastases (OR 0.72; CI 0.55-0.94; P = .01). SBDR portended less perioperative morbidity (OR 0.31; CI 0.21-0.46; P < .01), but not mortality (OR 0.52; CI 0.20-1.32; P = .17). SBDR was associated with locoregional recurrences (OR 1.88; CI 1.01-3.53; P = .02), and lymph node recurrences (OR 2.13; CI 1.42-3.2; P = .04). SBDR yielded decreased 5-year OS (OR 0.75; CI 0.65-0.85; P < .01). CONCLUSIONS: Despite decreased perioperative morbidity, SBDR appears to provide inferior oncologic control for BDC.

Analysis of the Survival Impact of Postoperative Chemotherapy After Preoperative Chemotherapy and Resection for Gastric Cancer.

BACKGROUND: Perioperative chemotherapy is a standard-of-care treatment for patients with gastric cancer. However, the impact of the postoperative chemotherapy (postCTX) component on overall survival (OS) is not well defined. METHODS: The National Cancer Database (NCDB) 2006-2014 was queried for patients who received preoperative chemotherapy (preCTX) and resection for gastric cancer. Analysis was performed to identify factors influencing receipt of postCTX. The impact of postCTX on OS was evaluated in propensity-matched groups. RESULTS: Among 3449 patients who received preCTX and resection for gastric cancer, 1091 (31.6%) received postCTX. Independent predictors of receiving postCTX were diagnosis after 2010 (odds ratio [OR] 1.985), distal tumor location (OR 1.348), and 15 or more lymph nodes examined (OR 1.214). Predictors of not receiving postCTX were older age (OR 0.985), comorbidity score higher than 1 (OR 0.592), and black race (OR 0.791). After propensity-matching (1091 per group), the median OS was 56.8 months for those who did receive postCTX versus 52.5 months for those who did not (p = 0.131). Subset analysis according to tumor grade, lymphovascular invasion, number of lymph nodes evaluated, T and N class, and AJCC stage identified an improvement in OS for the patients with N1 disease who received postCTX compared with those who did not (79.6 vs 41.3 months; p = 0.025). However, no other subgroup had a significant survival benefit. CONCLUSIONS: Additional postCTX was administered to a minority of patients who received preCTX and gastrectomy for gastric cancer, and its influence on OS appeared to be limited. Future trials should aim to define patients who will benefit from postCTX.

Implications of Conversion during Attempted Minimally Invasive Adrenalectomy for Adrenocortical Carcinoma.

BACKGROUND: Although advocated by some, minimally invasive adrenalectomy (MIA) for adrenocortical carcinoma (ACC) is controversial. Moreover, the oncologic implications for patients requiring conversion to an open procedure during attempted MIA for ACC are not extensively reported. PATIENTS AND METHODS: The National Cancer Database was queried for patients undergoing resection for ACC. Overall survival (OS) for patients undergoing successful MIA was compared with those requiring conversion, and additionally evaluated with a multivariable Cox regression analysis including other factors associated with OS. After propensity matching, those experiencing conversion were further compared with patients who underwent planned open resection. RESULTS: Among 196 patients undergoing attempted MIA for ACC, 38 (19.4%) required conversion. Independent of 90-day postoperative mortality, conversion was associated with significantly reduced OS compared with successful MIA (median 27.9 months versus not reached, p = 0.002). Even for tumors confined to the adrenal, conversion was associated with worse median OS compared with successful MIA (median 34.2 months versus not reached, p = 0.003). After propensity matching for clinicopathologic covariates to establish well-balanced cohorts (N = 38 per group), patients requiring conversion during MIA had significantly worse OS than those having planned open resection (27.9 months versus 50.5 months, p = 0.020). On multivariable analysis for predictors of OS, conversion during MIA (HR 2.32, p = 0.003) was independently associated with mortality. CONCLUSIONS: ACC is a rare tumor for which adequate oncologic resection is the only chance for cure. Given the relatively high rate of conversion and its associated inferior survival, open resection should be considered standard of care for known or suspected ACC.

Computational medicine, present and the future: obstetrics and gynecology perspective.

Medicine is, in its essence, decision making under uncertainty; the decisions are made about tests to be performed and treatments to be administered. Traditionally, the uncertainty in decision making was handled using expertise collected by individual providers and, more recently, systematic appraisal of research in the form of evidence-based medicine. The traditional approach has been used successfully in medicine for a very long time. However, it has substantial limitations because of the complexity of the system of the human body and healthcare. The complex systems are a network of highly coupled components intensely interacting with each other. These interactions give those systems redundancy and thus robustness to failure and, at the same time, equifinality, that is, many different causative pathways leading to the same outcome. The equifinality of the complex systems of the human body and healthcare system demand the individualization of medical care, medicine, and medical decision making. Computational models excel in modeling complex systems and, consequently, enabling individualization of medical decision making and medicine. Computational models are theory- or knowledge-based models, data-driven models, or models that combine both approaches. Data are essential, although to a different degree, for computational models to successfully represent complex systems. The individualized decision making, made possible by the computational modeling of complex systems, has the potential to revolutionize the entire spectrum of medicine from individual patient care to policymaking. This approach allows applying tests and treatments to individuals who receive a net benefit from them, for whom benefits outweigh the risk, rather than treating all individuals in a population because, on average, the population benefits. Thus, the computational modeling-enabled individualization of medical decision making has the potential to both improve health outcomes and decrease the costs of healthcare.

Elevated Serum α-Fetoprotein is Associated with Abbreviated Survival for Patients with Fibrolamellar Hepatocellular Carcinoma Who Undergo a Curative Resection.

BACKGROUND: Fibrolamellar hepatocellular carcinoma (FLC) is a rare variant of hepatocellular carcinoma (HCC), with most clinical data stemming from single-institution series. The variability in the literature lends support for analysis using a large national dataset. In doing so, we sought to (1) define the characteristics and outcomes of patients with FLC; (2) determine factors associated with survival in patients undergoing resection; and (3) compare the overall survival (OS) of patients with FLC with a matched group of patients with HCC. METHODS: The National Cancer Database was queried for patients with FLC, and their clinicopathologic features were recorded. Univariate and multivariate analyses were performed to delineate factors associated with survival. RESULTS: Between 2004 and 2015, 496 patients were diagnosed with FLC, 229 of whom underwent a curative resection. The median OS for patients with FLC undergoing curative resection was 78.5 months. Factors associated with abbreviated OS in this surgical cohort include multiple tumors [hazard ratio (HR) 3.15, p = 0.025], positive regional lymph nodes (HR 2.83, p = 0.023), and elevated serum α-fetoprotein (AFP; HR 2.81, p = 0.034). When the OS of patients with FLC was compared with a matched group of patients with HCC, no difference was detected (p = 0.748); however, patients with FLC and elevated AFP had abbreviated OS compared with patients with HCC and elevated AFP (43 vs. 82 months, p ≤ 0.001). CONCLUSIONS: Elevations in serum AFP occur more frequently than previously documented for patients with FLC and are associated with abbreviated OS. AFP levels may help guide the decision for operative intervention in patients with FLC.

Critical analysis of lymph node examination in patients undergoing curative-intent resection for adrenocortical carcinoma.

BACKGROUND: Adrenocortical carcinoma (ACC) is a rare tumor and the role of lymph node dissection remains ill-defined. This study evaluates the effect of nodal examination on prognosis and survival in patients undergoing curative-intent resection of ACC. METHODS: The National Cancer Database (2004-2015) was queried for patients undergoing margin-negative resection for ACC. Patients with distant metastases, neoadjuvant therapy, multivisceral resection and T4 tumors were excluded. RESULTS: Among 897 patients, 147 (16.4%) had lymph nodes examined. Factors associated with lymph node examination included increasing tumor size (P < .001), extra-adrenal extension (P < .001), open operation (P < .001), and resection at an academic facility (P = .003). Lymph node metastasis was significantly associated with extra-adrenal tumor extension (P = .04). Lymph node harvest, regardless of the number of nodes examined, was not associated with a survival benefit. Median overall survival was incrementally worse with increasing number of positive lymph nodes (88.2 months for N0, 34.9 months for 1-3 positive nodes, and 15.6 months for ≥4 positive nodes, P < .001). CONCLUSIONS: Lymph node harvest and lymph node metastasis were associated with more advanced tumors. Although nodal harvest did not offer a survival advantage, stratifying the nodal staging classification may provide important prognostic information.

Regulated proteolysis of Trop2 drives epithelial hyperplasia and stem cell self-renewal via ß-catenin signaling.

The cell surface protein Trop2 is expressed on immature stem/progenitor-like cells and is overexpressed in many epithelial cancers. However the biological function of Trop2 in tissue maintenance and tumorigenesis remains unclear. In this study, we demonstrate that Trop2 is a regulator of self-renewal, proliferation, and transformation. Trop2 controls these processes through a mechanism of regulated intramembrane proteolysis that leads to cleavage of Trop2, creating two products: the extracellular domain and the intracellular domain. The intracellular domain of Trop2 is released from the membrane and accumulates in the nucleus. Heightened expression of the Trop2 intracellular domain promotes stem/progenitor self-renewal through signaling via ß-catenin and is sufficient to initiate precursor lesions to prostate cancer in vivo. Importantly, we demonstrate that loss of ß-catenin or Trop2 loss-of-function cleavage mutants abrogates Trop2-driven self-renewal and hyperplasia in the prostate. These findings suggest that heightened expression of Trop2 is selected for in epithelial cancers to enhance the stem-like properties of self-renewal and proliferation. Defining the mechanism of Trop2 function in self-renewal and transformation is essential to identify new therapeutic strategies to block Trop2 activation in cancer.

The utilization and impact of adjuvant therapy following neoadjuvant therapy and resection of pancreatic adenocarcinoma: does more really matter?

BACKGROUND: Although neoadjuvant therapy is increasingly administered to patients with pancreatic ductal adenocarcinoma (PDAC), the impact of additional adjuvant therapy (AT) following resection is not well defined. METHODS: The National Cancer Database (NCDB) was queried for patients who received neoadjuvant therapy followed by R0 or R1 resection for PDAC. Factors influencing survival, including the receipt of AT were evaluated. RESULTS: Of patients receiving neoadjuvant therapy and resection 680 (33.8%) received AT and 1331 (66.2%) did not. For R0 resected patients (n = 1800), lymphovascular invasion (HR 1.24, p = 0.034) and increasing N classification (N1: HR 1.27, p = 0.019; N2: HR 1.51, p = 0.004) were associated with increased risk of death while AT was not associated with improved overall survival (OS) (HR 0.88, p = 0.179). Following R1 resection (n = 211), AT was associated with reduced risk of death (HR 0.57, p = 0.038). Within propensity matched cohorts, median OS for patients receiving and not receiving AT was 32.1 and 30.0 months after R0 resection (p = 0.184), and 23.6 and 20.5 months after R1 resection (p = 0.005). CONCLUSION: This analysis demonstrated that AT did not yield OS benefit for patients who had neoadjuvant therapy and R0 resection and a statistically significant, although relatively short, improvement in OS for patients who underwent R1 resection.

Resection and chemotherapy is the optimal treatment approach for patients with clinically node positive intrahepatic cholangiocarcinoma.

BACKGROUND: Clinically lymph node positive (cLNP) intrahepatic cholangiocarcinoma (ICC) carries a poor prognosis, without clear management guidelines for the practicing clinician. We sought to evaluate current practice patterns for cLNP ICC, including associations with survival. METHODS: The National Cancer Database was queried for patients with cLNP ICC, without extrahepatic metastases. RESULTS: We identified 1023 patients with cLNP ICC, 77%% (n = 784) of whom received chemotherapy alone. Resection was undertaken in 23% (n = 239) of patients and was most commonly utilized in combination with chemotherapy (n = 150). Median survival for all patients was 13.6 months. Patients undergoing resection in combination with chemotherapy were associated with an improved survival (22.5 months) as compared to those patients receiving chemotherapy alone (11.9 months) or resection alone (12.4 months) (p < 0.01). Finally, we compared the survival of patients with cLNP ICC with that of patients with pathologically proved lymph node positive (pLNP) ICC, all of whom were treated with resection with chemotherapy, and found no difference in survival (22.5 months-19.3 months, p = 0.99, respectively). CONCLUSIONS: While the decision to pursue resection for ICC is multifactorial and patient specific, the presence of clinically positive LNs should not represent a contraindication.

Laparoscopic Approach to Intrahepatic Cholangiocarcinoma is Associated with an Exacerbation of Inadequate Nodal Staging.

INTRODUCTION: Laparoscopic approach to liver resection is feasible and safe, though its utilization with intrahepatic cholangiocarcinoma (ICC) remains poorly documented. We sought to evaluate the use laparoscopy for ICC, and to examine adherence to oncologic standards. METHODS: The National Cancer Database was queried for patients who underwent resection for ICC. Patients were stratified by laparoscopic (LLR) versus open liver resection (OLR). Clinicopathologic parameters and hospital volumes were recorded. RESULTS: In total, 2309 patients with ICC underwent hepatic resection (1997 OLR, 312 LLR) between 2010 and 2015. LLR increased from 12 to 16% during the study period and was utilized more commonly than OLR for wedge and segmental resections (56% vs. 33%, p < 0.001). Nodal evaluation was performed in 58% of all patients with ICC and was significantly more common in patients undergoing OLR (61%, n = 1210) versus LLR (39%, n = 120), p < 0.001. Of the 120 patients undergoing LLR with any nodal evaluation, 31% (n = 37) had a single node evaluated. Patients who underwent LLR were less likely to have ≥ 6 lymph nodes evaluated compared with those who underwent OLR (9% vs. 15%, respectively, p < 0.001). CONCLUSIONS: The use of laparoscopy for ICC is associated with an exacerbation of inadequate nodal evaluation compared with open resections.

Functional screen identifies kinases driving prostate cancer visceral and bone metastasis.

Mutationally activated kinases play an important role in the progression and metastasis of many cancers. Despite numerous oncogenic alterations implicated in metastatic prostate cancer, mutations of kinases are rare. Several lines of evidence suggest that nonmutated kinases and their pathways are involved in prostate cancer progression, but few kinases have been mechanistically linked to metastasis. Using a mass spectrometry-based phosphoproteomics dataset in concert with gene expression analysis, we selected over 100 kinases potentially implicated in human metastatic prostate cancer for functional evaluation. A primary in vivo screen based on overexpression of candidate kinases in murine prostate cells identified 20 wild-type kinases that promote metastasis. We queried these 20 kinases in a secondary in vivo screen using human prostate cells. Strikingly, all three RAF family members, MERTK, and NTRK2 drove the formation of bone and visceral metastasis confirmed by positron-emission tomography combined with computed tomography imaging and histology. Immunohistochemistry of tissue microarrays indicated that these kinases are highly expressed in human metastatic castration-resistant prostate cancer tissues. Our functional studies reveal the strong capability of select wild-type protein kinases to drive critical steps of the metastatic cascade, and implicate these kinases in possible therapeutic intervention.

Activation of Notch1 synergizes with multiple pathways in promoting castration-resistant prostate cancer.

Metastatic castration-resistant prostate cancer (CRPC) is the primary cause of prostate cancer-specific mortality. Defining new mechanisms that can predict recurrence and drive lethal CRPC is critical. Here, we demonstrate that localized high-risk prostate cancer and metastatic CRPC, but not benign prostate tissues or low/intermediate-risk prostate cancer, express high levels of nuclear Notch homolog 1, translocation-associated (Notch1) receptor intracellular domain. Chronic activation of Notch1 synergizes with multiple oncogenic pathways altered in early disease to promote the development of prostate adenocarcinoma. These tumors display features of epithelial-to-mesenchymal transition, a cellular state associated with increased tumor aggressiveness. Consistent with its activation in clinical CRPC, tumors driven by Notch1 intracellular domain in combination with multiple pathways altered in prostate cancer are metastatic and resistant to androgen deprivation. Our study provides functional evidence that the Notch1 signaling axis synergizes with alternative pathways in promoting metastatic CRPC and may represent a new therapeutic target for advanced prostate cancer.