Primary results of patients with genitourinary malignancies presented at a Molecular Tumor Board.

PURPOSE: Personalized medicine poses great opportunities and challenges. While therapeutic landscape markedly expands, descriptions about status, clinical implementation and real-world benefits of precision oncology and molecular tumor boards (MTB) remain sparse, particularly in the field of genitourinary (GU) cancer. Hence, this study characterized urological MTB cases to better understand the potential role of MTB in uro-oncology. METHODS: We analyzed patients with complete data sets being reviewed at an MTB from January 2019 to October 2022, focusing on results of molecular analysis and treatment recommendations. RESULTS: We evaluated 102 patients with GU cancer with a mean patient age of 61.7 years. Prostate cancer (PCa) was the most frequent entity with 52.9% (54/102), followed by bladder cancer (18.6%, 19/102) and renal cell carcinoma (14.7%, 15/102). On average, case presentation at MTB took place 54.9 months after initial diagnosis and after 2.7 previous lines of therapy. During the study period 49.0% (50/102) of patients deceased. Additional MTB-based treatment recommendations were achieved in a majority of 68.6% (70/102) of patients, with a recommendation for targeted therapy in 64.3% (45/70) of these patients. Only 6.7% (3/45) of patients - due to different reasons - received the recommended MTB-based therapy tough, with 33% (1/3) of patients reaching disease control. Throughout the MTB study period, GU cancer case presentations and treatment recommendations increased, while the time interval between initial presentation and final therapy recommendation were decreasing over time. CONCLUSION: Presentation of uro-oncological patients at the MTB is a highly valuable measure for clinical decision-making. Prospectively, earlier presentation of patients at the MTB and changing legislative issues regarding comprehensive molecular testing and targeted treatment approval might further improve patients' benefits from comprehensive molecular diagnostics.

MDM2 Inhibition Enhances Immune Checkpoint Inhibitor Efficacy by Increasing IL15 and MHC Class II Production.

The treatment of patients with metastatic melanoma with immune checkpoint inhibitors (ICI) leads to impressive response rates but primary and secondary resistance to ICI reduces progression-free survival. Novel strategies that interfere with resistance mechanisms are key to further improve patient outcome during ICI therapy. P53 is often inactivated by mouse-double-minute-2 (MDM2), which may decrease immunogenicity of melanoma cells. We analyzed primary patient-derived melanoma cell lines, performed bulk sequencing analysis of patient-derived melanoma samples, and used melanoma mouse models to investigate the role of MDM2-inhibition for enhanced ICI therapy. We found increased expression of IL15 and MHC-II in murine melanoma cells upon p53 induction by MDM2-inhibition. MDM2-inhibitor induced MHC-II and IL15-production, which was p53 dependent as Tp53 knockdown blocked the effect. Lack of IL15-receptor in hematopoietic cells or IL15 neutralization reduced the MDM2-inhibition/p53-induction-mediated antitumor immunity. P53 induction by MDM2-inhibition caused anti-melanoma immune memory as T cells isolated from MDM2-inhibitor-treated melanoma-bearing mice exhibited anti-melanoma activity in secondary melanoma-bearing mice. In patient-derived melanoma cells p53 induction by MDM2-inhibition increased IL15 and MHC-II. IL15 and CIITA expressions were associated with a more favorable prognosis in patients bearing WT but not TP53-mutated melanoma. IMPLICATIONS: MDM2-inhibition represents a novel strategy to enhance IL15 and MHC-II-production, which disrupts the immunosuppressive tumor microenvironment. On the basis of our findings, a clinical trial combining MDM2-inhibition with anti-PD-1 immunotherapy for metastatic melanoma is planned.

Calpain-mediated cleavage generates a ZBTB18 N-terminal product that regulates HIF1A signaling and glioblastoma metabolism.

Proteolytic cleavage is an important post-translational mechanism to increase protein variability and functionality. In cancer, this process can be deregulated to shut off tumor-suppressive functions. Here, we report that in glioblastoma (GBM), the tumor suppressor ZBTB18 is targeted for protein cleavage by the intracellular protease calpain. The N-terminal (Nte) ZBTB18 cleaved fragment localizes to the cytoplasm and thus, is unable to exert the gene expression repressive function of the uncleaved protein. Mass spectrometry (MS) analysis indicates that the Nte ZBTB18 short form (SF) interacts with C-terminal (Cte) binding proteins 1 and 2 (CTBP1/2), which appear to be involved in HIF1A signaling activation. In fact, we show that the new ZBTB18 product activates HIF1A-regulated genes, which in turn lead to increased lipid uptake, lipid droplets (LD) accumulation, and enhanced metabolic activity. We propose that calpain-mediated ZBTB18 cleavage represents a new mechanism to counteract ZBTB18 tumor suppression and increase tumor-promoting functions in GBM cells.

Early assessment of circulating tumor DNA after curative-intent resection predicts tumor recurrence in early-stage and locally advanced non-small-cell lung cancer.

Circulating tumor DNA (ctDNA) has demonstrated great potential as a noninvasive biomarker to assess minimal residual disease (MRD) and profile tumor genotypes in patients with non-small-cell lung cancer (NSCLC). However, little is known about its dynamics during and after tumor resection, or its potential for predicting clinical outcomes. Here, we applied a targeted-capture high-throughput sequencing approach to profile ctDNA at various disease milestones and assessed its predictive value in patients with early-stage and locally advanced NSCLC. We prospectively enrolled 33 consecutive patients with stage IA to IIIB NSCLC undergoing curative-intent tumor resection (median follow-up: 26.2 months). From 21 patients, we serially collected 96 plasma samples before surgery, during surgery, 1-2 weeks postsurgery, and during follow-up. Deep next-generation sequencing using unique molecular identifiers was performed to identify and quantify tumor-specific mutations in ctDNA. Twelve patients (57%) had detectable mutations in ctDNA before tumor resection. Both ctDNA detection rates and ctDNA concentrations were significantly higher in plasma obtained during surgery compared with presurgical specimens (57% versus 19% ctDNA detection rate, and 12.47 versus 6.64 ng·mL-1 , respectively). Four patients (19%) remained ctDNA-positive at 1-2 weeks after surgery, with all of them (100%) experiencing disease progression at later time points. In contrast, only 4 out of 12 ctDNA-negative patients (33%) after surgery experienced relapse during follow-up. Positive ctDNA in early postoperative plasma samples was associated with shorter progression-free survival (P = 0.013) and overall survival (P = 0.004). Our findings suggest that, in early-stage and locally advanced NSCLC, intraoperative plasma sampling results in high ctDNA detection rates and that ctDNA positivity early after resection identifies patients at risk for relapse.

Kindlin-3 maintains marginal zone B cells but confines follicular B cell activation and differentiation.

Integrin-mediated interactions between hematopoietic cells and their microenvironment are important for the development and function of immune cells. Here, the role of the integrin adaptor Kindlin-3 in B cell homeostasis is studied. Comparing the individual steps of B cell development in B cell-specific Kindlin-3 or alpha4 integrin knockout mice, we found in both conditions a phenotype of reduced late immature, mature, and recirculating B cells in the bone marrow. In the spleen, constitutive B cell-specific Kindlin-3 knockout caused a loss of marginal zone B cells and an unexpected expansion of follicular B cells. Alpha4 integrin deficiency did not induce this phenotype. In Kindlin-3 knockout B cells VLA-4 as well as LFA-1-mediated adhesion was abrogated, and short-term homing of these cells in vivo was redirected to the spleen. Upon inducible Kindlin-3 knockout, marginal zone B cells were lost due to defective retention within 2 weeks, while follicular B cell numbers were unaltered. Kindlin-3 deficient follicular B cells displayed higher IgD, CD40, CD44, CXCR5, and EBI2 levels, and elevated PI3K signaling upon CXCR5 stimulation. They also showed transcriptional signatures of spontaneous follicular B cell activation. This activation manifested in scattered germinal centers in situ, early plasmablasts differentiation, and signs of IgG class switch.

Challenges and Experiences Extending the cBioPortal for Cancer Genomics to a Molecular Tumor Board Platform.

In Molecular Tumor Boards (MTBs), therapy recommendations for cancer patients are discussed. To aid decision-making based on the patient's molecular profile, the research platform cBioPortal was extended based on users' requirements. Additionally, a comprehensive dockerized workflow was developed to support the deployment of cBioPortal and connected services. In this work, we present the challenges and experiences of nearly two years of implementing and deploying an MTB platform based on cBioPortal and compare those to findings of a previous study.

Infection of HeLa cells with Chlamydia trachomatis inhibits protein synthesis and causes multiple changes to host cell pathways.

The obligate intracellular bacterium Chlamydia trachomatis replicates in a cytosolic vacuole in human epithelial cells. Infection of human cells with C. trachomatis causes substantial changes to many host cell-signalling pathways, but the molecular basis of such influence is not well understood. Studies of gene transcription of the infected cell have shown altered transcription of many host cell genes, indicating a transcriptional response of the host cell to the infection. We here describe that infection of HeLa cells with C. trachomatis as well as infection of murine cells with Chlamydia muridarum substantially inhibits protein synthesis of the infected host cell. This inhibition was accompanied by changes to the ribosomal profile of the infected cell indicative of a block of translation initiation, most likely as part of a stress response. The Chlamydia protease-like activity factor (CPAF) also reduced protein synthesis in uninfected cells, although CPAF-deficient C. trachomatis showed no defect in this respect. Analysis of polysomal mRNA as a proxy of actively transcribed mRNA identified a number of biological processes differentially affected by chlamydial infection. Mapping of differentially regulated genes onto a protein interaction network identified nodes of up- and down-regulated networks during chlamydial infection. Proteomic analysis of protein synthesis further suggested translational regulation of host cell functions by chlamydial infection. These results demonstrate reprogramming of the host cell during chlamydial infection through the alteration of protein synthesis.

Microenvironment-Derived Regulation of HIF Signaling Drives Transcriptional Heterogeneity in Glioblastoma Multiforme.

The evolving and highly heterogeneous nature of malignant brain tumors underlies their limited response to therapy and poor prognosis. In addition to genetic alterations, highly dynamic processes, such as transcriptional and metabolic reprogramming, play an important role in the development of tumor heterogeneity. The current study reports an adaptive mechanism in which the metabolic environment of malignant glioma drives transcriptional reprogramming. Multiregional analysis of a glioblastoma patient biopsy revealed a metabolic landscape marked by varying stages of hypoxia and creatine enrichment. Creatine treatment and metabolism was further shown to promote a synergistic effect through upregulation of the glycine cleavage system and chemical regulation of prolyl-hydroxylase domain. Consequently, creatine maintained a reduction of reactive oxygen species and change of the α-ketoglutarate/succinate ratio, leading to an inhibition of HIF signaling in primary tumor cell lines. These effects shifted the transcriptional pattern toward a proneural subtype and reduced the rate of cell migration and invasion in vitroImplications: Transcriptional subclasses of glioblastoma multiforme are heterogeneously distributed within the same tumor. This study uncovered a regulatory function of the tumor microenvironment by metabolism-driven transcriptional reprogramming in infiltrating glioma cells. Mol Cancer Res; 16(4); 655-68. ©2018 AACR.

The use of urinary proteomics in the assessment of suitability of mouse models for ageing.

Ageing is a complex process characterised by a systemic and progressive deterioration of biological functions. As ageing is associated with an increased prevalence of age-related chronic disorders, understanding its underlying molecular mechanisms can pave the way for therapeutic interventions and managing complications. Animal models such as mice are commonly used in ageing research as they have a shorter lifespan in comparison to humans and are also genetically close to humans. To assess the translatability of mouse ageing to human ageing, the urinary proteome in 89 wild-type (C57BL/6) mice aged between 8-96 weeks was investigated using capillary electrophoresis coupled to mass spectrometry (CE-MS). Using age as a continuous variable, 295 peptides significantly correlated with age in mice were identified. To investigate the relevance of using mouse models in human ageing studies, a comparison was performed with a previous correlation analysis using 1227 healthy subjects. In mice and humans, a decrease in urinary excretion of fibrillar collagens and an increase of uromodulin fragments was observed with advanced age. Of the 295 peptides correlating with age, 49 had a strong homology to the respective human age-related peptides. These ortholog peptides including several collagen (N = 44) and uromodulin (N = 5) fragments were used to generate an ageing classifier that was able to discriminate the age among both wild-type mice and healthy subjects. Additionally, the ageing classifier depicted that telomerase knock-out mice were older than their chronological age. Hence, with a focus on ortholog urinary peptides mouse ageing can be translated to human ageing.

Targeting of apoptotic pathways by SMAC or BH3 mimetics distinctly sensitizes paclitaxel-resistant triple negative breast cancer cells.

Standard chemotherapy is the only systemic treatment for triple-negative breast cancer (TNBC), and despite the good initial response, resistance remains a major therapeutic obstacle. Here, we employed a High-Throughput Screen to identify targeted therapies that overcome chemoresistance in TNBC. We applied short-term paclitaxel treatment and screened 320 small-molecule inhibitors of known targets to identify drugs that preferentially and efficiently target paclitaxel-treated TNBC cells. Among these compounds the SMAC mimetics (BV6, Birinapant) and BH3-mimetics (ABT-737/263) were recognized as potent targeted therapy for multiple paclitaxel-residual TNBC cell lines. However, acquired paclitaxel resistance through repeated paclitaxel pulses result in desensitization to BV6, but not to ABT-263, suggesting that short- and long-term paclitaxel resistance are mediated by distinct mechanisms. Gene expression profiling of paclitaxel-residual, -resistant and naïve MDA-MB-231 cells demonstrated that paclitaxel-residual, as opposed to -resistant cells, were characterized by an apoptotic signature, with downregulation of anti-apoptotic genes (BCL2, BIRC5), induction of apoptosis inducers (IL24, PDCD4), and enrichment of TNFα/NF-κB pathway, including upregulation of TNFSF15, coupled with cell-cycle arrest. BIRC5 and FOXM1 downregulation and IL24 induction was also evident in breast cancer patient datasets following taxane treatment. Exposure of naïve or paclitaxel-resistant cells to supernatants of paclitaxel-residual cells sensitized them to BV6, and treatment with TNFα enhanced BV6 potency, suggesting that sensitization to BV6 is mediated, at least partially, by secreted factor(s). Our results suggest that administration of SMAC or BH3 mimetics following short-term paclitaxel treatment could be an effective therapeutic strategy for TNBC, while only BH3-mimetics could effectively overcome long-term paclitaxel resistance.

The small EF-hand Ca2+ binding protein S100A1 increases contractility and Ca2+ cycling in rat cardiac myocytes.

S100A1 is an interesting Ca2+ binding protein with respect to muscle physiology as it is preferentially expressed in cardiac muscle and colocalizes with the sarcolemmal and the sarcoplasmic reticulum membranes as well as with the sarcomere. It is therefore conceivable that S100A1 may play a specific role in the regulation of cardiac Ca2+ homeostasis and contractility. We therefore investigated the impact of adenoviral S100A1 overexpression on fractional shortening (FS%) and systolic Ca2+ transients in adult rat cardiomyocytes as well as of S100A1 protein on SERCA activity in skinned cell preparation. In our setting S100A1 gene transfer increased FS% by 55%, systolic Ca2+ amplitudes by 62%, while S100A1 protein increased SERCA activity by 28%. Importantly, the gain in systolic Ca2+ supply was not only seen on basal conditions but also with isoproterenol-stimulated Ca2+ cycling. Thus, S100A1 enhances cardiac contractility by increasing intracellular Ca2+ fluxes at least in part due to a modulation of SERCA. Since earlier observations demonstrated S100A1 protein levels to be increased in compensatory hypertrophy and significantly downregulated in end stage heart failure, these functional data suggest that S100A1 is a novel determinant of cardiac function whose expression levels are causally related to the prevailing contractile state of the heart.