Epigenetic regulation during cancer transitions across 11 tumour types.

Chromatin accessibility is essential in regulating gene expression and cellular identity, and alterations in accessibility have been implicated in driving cancer initiation, progression and metastasis1-4. Although the genetic contributions to oncogenic transitions have been investigated, epigenetic drivers remain less understood. Here we constructed a pan-cancer epigenetic and transcriptomic atlas using single-nucleus chromatin accessibility data (using single-nucleus assay for transposase-accessible chromatin) from 225 samples and matched single-cell or single-nucleus RNA-sequencing expression data from 206 samples. With over 1 million cells from each platform analysed through the enrichment of accessible chromatin regions, transcription factor motifs and regulons, we identified epigenetic drivers associated with cancer transitions. Some epigenetic drivers appeared in multiple cancers (for example, regulatory regions of ABCC1 and VEGFA; GATA6 and FOX-family motifs), whereas others were cancer specific (for example, regulatory regions of FGF19, ASAP2 and EN1, and the PBX3 motif). Among epigenetically altered pathways, TP53, hypoxia and TNF signalling were linked to cancer initiation, whereas oestrogen response, epithelial-mesenchymal transition and apical junction were tied to metastatic transition. Furthermore, we revealed a marked correlation between enhancer accessibility and gene expression and uncovered cooperation between epigenetic and genetic drivers. This atlas provides a foundation for further investigation of epigenetic dynamics in cancer transitions.

PACT: a pipeline for analysis of circulating tumor DNA.

MOTIVATION: Detection of genomic alterations in circulating tumor DNA (ctDNA) is currently used for active clinical monitoring of cancer progression and treatment response. While methods for analysis of small mutations are more developed, strategies for detecting structural variants (SVs) in ctDNA are limited. Additionally, reproducibly calling small-scale mutations, copy number alterations, and SVs in ctDNA is challenging due to the lack to unified tools for these different classes of variants. RESULTS: We developed a unified pipeline for the analysis of ctDNA [Pipeline for the Analysis of ctDNA (PACT)] that accurately detects SVs and consistently outperformed similar tools when applied to simulated, cell line, and clinical data. We provide PACT in the form of a Common Workflow Language pipeline which can be run by popular workflow management systems in high-performance computing environments. AVAILABILITY AND IMPLEMENTATION: PACT is freely available at https://github.com/ChrisMaherLab/PACT.

Chemerin triggers migration of a CD8 T cell subset with natural killer cell functions.

The recruitment of cells with effector functions into the tumor microenvironment holds potential for delaying cancer progression. We show that subsets of human CD28-effector CD8 T cells, CCR7- CD45RO+ effector memory, and CCR7- CD45RO- effector memory RA phenotypes, express the chemerin receptor CMKLR1 and bind chemerin via the receptor. CMKLR1-expressing human CD8 effector memory T cells present gene, protein, and cytotoxic features of NK cells. Active chemerin promotes chemotaxis of CMKLR1-expressing CD8 effector memory cells and triggers activation of the α4ß1 integrin. In an experimental prostate tumor mouse model, chemerin expression is downregulated in the tumor microenvironment, which is associated with few tumor-infiltrating CD8+ T cells, while forced overexpression of chemerin by mouse prostate cancer cells leads to an accumulation of intra-tumor CD8+ T cells. Furthermore, α4 integrin blockade abrogated the chemerin-dependent recruitment of CD8+ T effector memory cells into implanted prostate tumors in vivo. The results identify a role for chemerin:CMKLR1 in defining a specialized NK-like CD8 T cell, and suggest the use of chemerin-dependent modalities to target effector CMKLR1-expressing T cells to the tumor microenvironment for immunotherapeutic purposes.

Active surveillance of metastatic renal cell carcinoma: Results from a prospective observational study (MaRCC).

BACKGROUND: Systemic therapy (ST) can be deferred in patients who have metastatic renal cell carcinoma (mRCC) and slow-growing metastases. Currently, this subset of patients managed with active surveillance (AS) is not well described in the literature. METHODS: This was a prospective observational study of patients with mRCC across 46 US community and academic centers. The objective was to describe baseline characteristics and demographics of patients with mRCC initially managed by AS, reasons for AS, and patient outcomes. Descriptive statistics were used to characterize demographics, baseline characteristics, and patient-related outcomes. Wilcoxon 2-sample rank-sum tests and χ2 tests were used to assess differences between ST and AS cohorts in continuous and categorical variables, respectively. Kaplan-Meier survival curves were used to assess survival. RESULTS: Of 504 patients, mRCC was initially managed by AS (n = 143) or ST (n = 305); 56 patients were excluded from the analysis. Disease was present in 69% of patients who received AS, whereas the remaining 31% had no evidence of disease. At data cutoff, 72 of 143 patients (50%) in the AS cohort had not received ST. The median overall survival was not reached (95% CI, 122 months to not estimable) in patients who received AS versus 30 months (95% CI, 25-44 months) in those who received ST. Quality of life at baseline was significantly better in patients who were managed with AS versus ST. CONCLUSIONS: AS occurs frequently (32%) in real-world clinical practice and appears to be a safe and appropriate alternative to immediate ST in selected patients.

Clinical Results and Biomarker Analyses of Axitinib and TRC105 versus Axitinib Alone in Patients with Advanced or Metastatic Renal Cell Carcinoma (TRAXAR).

LESSONS LEARNED: The combination of carotuximab with axitinib did not provide a benefit over axitinib monotherapy in patients with metastatic clear cell renal cell carcinoma who had previously progressed on one or more vascular endothelial growth factor (VEGF)-targeted therapies. Exploratory evaluation of pretreatment circulating biomarkers suggested the combination might benefit patients who have low baseline VEGF levels. BACKGROUND: Endoglin is an angiogenic receptor expressed on proliferating tumor vessels and renal cell carcinoma (RCC) stem cells that is implicated as a mechanism of resistance to vascular endothelial growth factor receptor (VEGFR) inhibitors. This study evaluated an antiendoglin monoclonal antibody (carotuximab, TRC105) combined with axitinib in patients with advanced or metastatic clear cell renal cell carcinoma (mccRCC) who had progressed following one or more prior VEGF inhibitors. METHODS: TRAXAR was a multicenter, international randomized 1:1 (stratified by ECOG, 0 vs. 1), phase II study of carotuximab combined with axitinib versus axitinib alone in mccRCC patients who had progressed following one or more prior VEGF inhibitors. The primary endpoint was progression-free survival (PFS) assessed by independent central review (ICR) per RECIST 1.1 RESULTS: A total of 150 patients were randomized. The combination therapy resulted in shorter median PFS by RECIST 1.1 than axitinib monotherapy (6.7 vs. 11.4 months). The combination was tolerated similarly to axitinib monotherapy, and there were no treatment related deaths. Exploratory evaluation of pretreatment circulating biomarkers suggested the combination might benefit patients who have low baseline VEGF levels. CONCLUSION: The combination of carotuximab with axitinib did not demonstrate additional efficacy over single agent axitinib in patients with mccRCC who progressed following one or more prior VEGF inhibitor treatment.

Plasmacytoid dendritic cells transport peripheral antigens to the thymus to promote central tolerance.

Central tolerance can be mediated by peripheral dendritic cells (DCs) that transport innocuous antigens (Ags) to the thymus for presentation to developing T cells, but the responsible DC subsets remained poorly defined. Immature plasmacytoid DCs (pDCs) express CCR9, a chemokine receptor involved in migration of T cell precursors to the thymus. We show here that CCR9 mediated efficient thymic entry of endogenous or i.v. transfused pDCs. pDCs activated by Toll-like receptor (TLR) ligands downregulated CCR9 and lost their ability to home to the thymus. Moreover, endogenous pDCs took up subcutaneously injected fluorescent Ag and, in the absence of TLR signals, transported Ag to the thymus in a CCR9-dependent fashion. Injected, Ag-loaded pDCs effectively deleted Ag-specific thymocytes, and this thymic clonal deletion required CCR9-mediated homing and was prevented by infectious signals. Thus, peripheral pDCs can contribute to immune tolerance through CCR9-dependent transport of peripheral Ags and subsequent deletion of Ag-reactive thymocytes.

Cabozantinib in advanced non-clear-cell renal cell carcinoma: a multicentre, retrospective, cohort study.

BACKGROUND: Cabozantinib is approved for patients with metastatic renal cell carcinoma on the basis of studies done in clear-cell histology. The activity of cabozantinib in patients with non-clear-cell renal cell carcinoma is poorly characterised. We sought to analyse the antitumour activity and toxicity of cabozantinib in advanced non-clear-cell renal cell carcinoma. METHODS: We did a multicentre, international, retrospective cohort study of patients with metastatic non-clear-cell renal cell carcinoma treated with oral cabozantinib during any treatment line at 22 centres: 21 in the USA and one in Belgium. Eligibility required patients with histologically confirmed non-clear-cell renal cell carcinoma who received cabozantinib for metastatic disease during any treatment line roughly between 2015 and 2018. Mixed tumours with a clear-cell histology component were excluded. No other restrictive inclusion criteria were applied. Data were obtained from retrospective chart review by investigators at each institution. Demographic, surgical, pathological, and systemic therapy data were captured with uniform database templates to ensure consistent data collection. The main objectives were to estimate the proportion of patients who achieved an objective response, time to treatment failure, and overall survival after treatment. FINDINGS: Of 112 identified patients with non-clear-cell renal cell carcinoma treated at the participating centres, 66 (59%) had papillary histology, 17 (15%) had Xp11.2 translocation histology, 15 (13%) had unclassified histology, ten (9%) had chromophobe histology, and four (4%) had collecting duct histology. The proportion of patients who achieved an objective response across all histologies was 30 (27%, 95% CI 19-36) of 112 patients. At a median follow-up of 11 months (IQR 6-18), median time to treatment failure was 6·7 months (95% CI 5·5-8·6), median progression-free survival was 7·0 months (5·7-9·0), and median overall survival was 12·0 months (9·2-17·0). The most common adverse events of any grade were fatigue (58 [52%]), and diarrhoea (38 [34%]). The most common grade 3 events were skin toxicity (rash and palmar-plantar erythrodysesthesia; five [4%]) and hypertension (four [4%]). No treatment-related deaths were observed. Across 54 patients with available next-generation sequencing data, the most frequently altered somatic genes were CDKN2A (12 [22%]) and MET (11 [20%]) with responses seen irrespective of mutational status. INTERPRETATION: While we await results from prospective studies, this real-world study provides evidence supporting the antitumour activity and safety of cabozantinib across non-clear-cell renal cell carcinomas. Continued support of international collaborations and prospective ongoing studies targeting non-clear-cell renal cell carcinoma subtypes and specific molecular alterations are warranted to improve outcomes across these rare diseases with few evidence-based treatment options. FUNDING: None.

Immunotherapy in Metastatic Castration-Resistant Prostate Cancer: Past and Future Strategies for Optimization.

PURPOSE OF REVIEW: To date, prostate cancer has been poorly responsive to immunotherapy. In the current review, we summarize and discuss the current literature on the use of vaccine therapy and checkpoint inhibitor immunotherapy in metastatic castration-resistant prostate cancer (mCRPC). RECENT FINDINGS: Sipuleucel-T currently remains the only FDA-approved immunotherapeutic agent for prostate cancer. Single-agent phase 3 vaccine trials with GVAX and PROSTVAC have failed to demonstrate survival benefit to date. Clinical trials using combination approaches, including combination PROSTVAC along with a neoantigen vaccine and checkpoint inhibitor immunotherapy, are ongoing. Checkpoint inhibitor monotherapy clinical trials have demonstrated limited efficacy in advanced prostate cancer, and combination approaches and molecular patient selection are currently under investigation. The optimal use of vaccine therapy and checkpoint inhibitor immunotherapy in metastatic castration-resistant prostate cancer remains to be determined. Ongoing clinical trials will continue to inform future clinical practice.

Contemporary Management of the Newly Diagnosed Prostate Cancer Patient with Metastatic Disease at Presentation.

PURPOSE OF REVIEW: Androgen deprivation therapy (ADT) has been the standard-of-care (SOC) for metastatic hormone-sensitive prostate cancer (mHSPC) since the middle of the twentieth century. Recently, several practice-changing trials have added new therapy options for these patients. Here we review these studies and discuss guidelines on treatment decision-making. RECENT FINDINGS: A trio of studies (GETUG-AFU15, STAMPEDE, CHAARTED) combining docetaxel chemotherapy with ADT all showed clinical benefit of the addition. More recently, the LATITUDE and STAMPEDE-Abiraterone studies established yet another new option for up-front treatment of newly diagnosed metastatic prostate cancer, showing significantly prolonged overall survival (OS) and progression-free survival (PFS) compared to ADT alone in men with high-risk mHSPC. With the recent demonstration that adding either docetaxel or abiraterone plus prednisone to ADT significantly improves survival in mHSPC, physicians are confronted by a growing body of clinical data and treatment regimens. Men with high-volume and/or high-risk metastatic disease should not be treated with ADT alone without strong consideration of docetaxel or abiraterone. The choice of a first-line therapy should be made based on risk stratification, patients' comorbidities, toxicities, quality-of-life (QOL) considerations, and cost.

Treatment of Advanced Prostate Cancer.

Advanced prostate cancer is a heterogenous disease with multiple treatment options. Patients with advanced disease are stratified based evidence of metastasis and sensitivity to hormone therapy. Men with hormone sensitive disease are treated with androgen deprivation therapy and possibly chemotherapy. The treatment options for men with castrate resistant disease are rapidly evolving with multiple recently approved treatment options. Determining the proper sequence and combination of these therapies remains a work in progress.

A Proposal for the Comprehensive Care of Men on Androgen Deprivation Therapy: Recommendations From the Multidisciplinary Prostate Cancer 360 Working Group.

INTRODUCTION: To promote comprehensive care of patients throughout the androgen deprivation therapy (ADT) prescribing process, the Prostate Cancer 360 (PC360) Working Group developed monitoring and management recommendations intended to mitigate or prevent ADT-associated adverse events. METHODS: The PC360 Working Group included 14 interdisciplinary experts with a dedicated clinical interest in prostate cancer and ADT management. The working group defined challenges associated with ADT adverse event management and then collaboratively developed comprehensive care recommendations intended to be practical for ADT prescribers. RESULTS: The PC360 Working Group developed both overarching recommendations for ADT adverse event management and specific recommendations across 5 domains (cardiometabolic, bone, sexual, psychological, and lifestyle). The working group recommends an interdisciplinary, team-based approach wherein the ADT prescriber retains an oversight role for ADT management while empowering patients and their primary and specialty care providers to manage risk factors. The PC360 recommendations also emphasize the importance of proactive patient education that involves partners or other support providers. Recommended monitoring and assessment tools, risk factor management, and patient counseling points are also included for the 5 identified domains, with an emphasis on lifestyle and behavioral interventions that can improve quality of life and reduce the risk for ADT-associated complications. CONCLUSIONS: Comprehensive care of patients receiving ADT requires early and ongoing coordinated management of a variety of health domains, including cardiometabolic, bone, sexual, psychological health. Patient education and primary care provider involvement should begin prior to ADT initiation and continue throughout treatment to improve patient and partner quality of life.

High-Dimensional Analyses Reveal IL15 Enhances Activation of Sipuleucel-T Lymphocyte Subsets and Reverses Immunoresistance.

Sipuleucel-T (sip-T) is the only FDA-approved autologous cellular immunotherapy for metastatic castration-resistant prostate cancer (mCRPC). To elucidate parameters of the response profile to this therapy, we report high-dimensional analyses of sip-T using cytometry by time of flight (CyTOF) and show a lymphoid predominance, with CD3+ T cells constituting the highest proportion (median ∼60%) of sip-T, followed by B cells, and natural killer (NK) and NKT cells. We hypothesized that treatment of sip-T with homeostatic cytokines known to activate/expand effector lymphocytes could augment efficacy against prostate tumors. Of the cytokines tested, IL15 was the most effective at enhancing activation and proliferation of effector lymphocytes, as well as augmenting tumor cytotoxicity in vitro. Co-culture of sip-T with IL15 and control or prostate-relevant antigens showed substantial activation and expansion of CD8+ T cells and NKT cells in an antigen-specific manner. Adoptive transfer of IL15-treated sip-T into NSG mice resulted in more potent prostate tumor growth inhibition compared with control sip-T. Evaluation of tumor-infiltrating lymphocytes revealed a 2- to 14-fold higher influx of sip-T and a significant increase in IFNγ producing CD8+ T cells and NKT cells within the tumor microenvironment in the IL15 group. In conclusion, we put forward evidence that IL15 treatment can enhance the functional antitumor immunity of sip-T, providing rationale for combining IL15 or IL15 agonists with sip-T to treat patients with mCRPC.

Beyond Average: α-Particle Distribution and Dose Heterogeneity in Bone Metastatic Prostate Cancer.

α-particle emitters are emerging as a potent modality for disseminated cancer therapy because of their high linear energy transfer and localized absorbed dose profile. Despite great interest and pharmaceutical development, there is scant information on the distribution of these agents at the scale of the α-particle pathlength. We sought to determine the distribution of clinically approved [223Ra]RaCl2 in bone metastatic castration-resistant prostate cancer at this resolution, for the first time to our knowledge, to inform activity distribution and dose at the near-cell scale. Methods: Biopsy specimens and blood were collected from 7 patients 24 h after administration. 223Ra activity in each sample was recorded, and the microstructure of biopsy specimens was analyzed by micro-CT. Quantitative autoradiography and histopathology were segmented and registered with an automated procedure. Activity distributions by tissue compartment and dosimetry calculations based on the MIRD formalism were performed. Results: We revealed the activity distribution differences across and within patient samples at the macro- and microscopic scales. Microdistribution analysis confirmed localized high-activity regions in a background of low-activity tissue. We evaluated heterogeneous α-particle emission distribution concentrated at bone-tissue interfaces and calculated spatially nonuniform absorbed-dose profiles. Conclusion: Primary patient data of radiopharmaceutical therapy distribution at the small scale revealed that 223Ra uptake is nonuniform. Dose estimates present both opportunities and challenges to enhance patient outcomes and are a first step toward personalized treatment approaches and improved understanding of α-particle radiopharmaceutical therapies.

Evaluating Immune Checkpoint Blockade in Metastatic Castration-Resistant Prostate Cancers with Deleterious CDK12 Alterations in the Phase 2 IMPACT Trial.

PURPOSE: CDK12 inactivation in metastatic castration-resistant prostate cancer (mCRPC) may predict immunotherapy responses. This phase 2 trial evaluated the efficacy of immune checkpoint inhibitor (ICI) therapy in patients with CDK12-altered mCRPC. PATIENTS AND METHODS: Eligible patients had mCRPC with deleterious CDK12 alterations and any prior therapies except ICI. Cohort A received ipilimumab (1 mg/kg) with nivolumab (3 mg/kg) every 3 weeks for up to four cycles, followed by nivolumab 480 mg every 4 weeks. Cohort C received nivolumab alone 480 mg every 4 weeks. Patients with CDK12-altered nonprostate tumors were enrolled in cohort B and not reported. The primary endpoint was a 50% reduction in PSA (PSA50). Key secondary endpoints included PSA progression-free survival, overall survival, objective response rate, and safety. RESULTS: PSA was evaluable in 23 patients in cohort A and 14 in cohort C. Median lines of prior therapy were two in cohorts A and C, including any prior novel hormonal agent (74% and 79%) and chemotherapy (57% and 36%). The PSA50 rate was 9% [95% confidence interval (CI), 1%-28%] in cohort A with two responders; neither had microsatellite instability or a tumor mutational burden >10 mutations/megabase. No PSA50 responses occurred in cohort C. Median PSA progression-free survival was 7.0 months (95% CI, 3.6-11.4) in cohort A and 4.5 months (95% CI, 3.4-13.8) in cohort C. Median overall survival was 9.0 months (95% CI, 6.2-12.3) in cohort A and 13.8 months (95% CI, 3.6-not reached) in cohort C. CONCLUSIONS: There was minimal activity with ICI therapy in patients with CDK12-altered mCRPC.

Three- and Seven-month Prostate-specific Antigen Levels as Prognostic Markers for Overall Survival in Metastatic Hormone-sensitive Prostate Cancer: Results from SWOG S1216, a Phase 3 Randomized Trial of Androgen Deprivation Plus Orteronel or Bicalutamide.

BACKGROUND: A robust decrease in prostate-specific antigen (PSA) in response to androgen deprivation therapy (ADT) has been evaluated as a prognostic factor in patients with metastatic hormone-sensitive prostate cancer (mHSPC) since 2006, but the treatment of mHSPC has since evolved to include intensified therapy. OBJECTIVE: We assessed the association of PSA levels at 3 (PSA-3mo) and 7 (PSA-7mo) mo with overall survival (OS) in patients with mHSPC treated with ADT combined with either bicalutamide or orteronel in the S1216 phase 3 clinical trial. DESIGN, SETTING, AND PARTICIPANTS: PSA responses to treatment of patients in the S1216 trial were categorized as: complete response (CR) if PSA was ≤0.2 ng/ml, partial response if PSA was >0.2 and ≤4 ng/ml, and no response (NR) if PSA was >4 ng/ml. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: A Cox analysis (adjusted for treatment arm and three stratification factors: performance status, severity of disease, and early vs late induction) was used for OS association. While PSA-7mo association was a prespecified objective, PSA-3mo association was also evaluated. RESULTS AND LIMITATIONS: A total of 1251 and 1231 patients from the S1216 study were evaluable for PSA-3mo and PSA-7mo, respectively. A PSA-7mo CR was associated with improved OS compared with NR (HR: 0.20; p < 0.0001). A PSA-3mo CR showed a similar association to NR (HR: 0.34; p < 0.0001). The association of a PSA response with survival did not differ by treatment arm at either time point. CONCLUSIONS: The PSA-3mo and PSA-7mo responses were strongly associated with OS; taken with other emerging prognostic biomarkers, these markers may allow for early identification of patients at the highest risk of death, aid with counseling in clinical practice, and permit design of future clinical trials targeting these patients. PATIENT SUMMARY: A low prostate-specific antigen level at 3 or 7 mo after starting treatment for metastatic hormone-sensitive prostate cancer predicts longer survival regardless of the first treatment given with androgen deprivation therapy.

A Phase 1/2 multicenter trial of DKN-01 as monotherapy or in combination with docetaxel for the treatment of metastatic castration-resistant prostate cancer (mCRPC).

BACKGROUND: Dickkopf-related protein 1 (DKK1) is a Wingless-related integrate site (Wnt) signaling modulator that is upregulated in prostate cancers (PCa) with low androgen receptor expression. DKN-01, an IgG4 that neutralizes DKK1, delays PCa growth in pre-clinical DKK1-expressing models. These data provided the rationale for a clinical trial testing DKN-01 in patients with metastatic castration-resistant PCa (mCRPC). METHODS: This was an investigator-initiated parallel-arm phase 1/2 clinical trial testing DKN-01 alone (monotherapy) or in combination with docetaxel 75 mg/m2 (combination) for men with mCRPC who progressed on ≥1 AR signaling inhibitors. DKK1 status was determined by RNA in-situ expression. The primary endpoint of the phase 1 dose escalation cohorts was the determination of the recommended phase 2 dose (RP2D). The primary endpoint of the phase 2 expansion cohorts was objective response rate by iRECIST criteria in patients treated with the combination. RESULTS: 18 pts were enrolled into the study-10 patients in the monotherapy cohorts and 8 patients in the combination cohorts. No DLTs were observed and DKN-01 600 mg was determined as the RP2D. A best overall response of stable disease occurred in two out of seven (29%) evaluable patients in the monotherapy cohort. In the combination cohort, five out of seven (71%) evaluable patients had a partial response (PR). A median rPFS of 5.7 months was observed in the combination cohort. In the combination cohort, the median tumoral DKK1 expression H-score was 0.75 and the rPFS observed was similar between patients with DKK1 H-score ≥1 versus H-score = 0. CONCLUSION: DKN-01 600 mg was well tolerated. DKK1 blockade has modest anti-tumor activity as a monotherapy for mCRPC. Anti-tumor activity was observed in the combination cohorts, but the response duration was limited. DKK1 expression in the majority of mCRPC is low and did not clearly correlate with anti-tumor activity of DKN-01 plus docetaxel.

Extranodal dissemination of non-Hodgkin lymphoma requires CD47 and is inhibited by anti-CD47 antibody therapy.

Non-Hodgkin lymphoma (NHL) presents as both localized and disseminated disease with spread to secondary sites carrying a worse prognosis. Although pathways driving NHL dissemination have been identified, there are few therapies capable of inhibiting them. Here, we report a novel role for the immunomodulatory protein CD47 in NHL dissemination, and we demonstrate that therapeutic targeting of CD47 can prevent such spread. We developed 2 in vivo lymphoma metastasis models using Raji cells, a human NHL cell line, and primary cells from a lymphoma patient. CD47 expression was required for Raji cell dissemination to the liver in mouse xenotransplants. Targeting of CD47 with a blocking antibody inhibited Raji cell dissemination to major organs, including the central nervous system, and inhibited hematogenous dissemination of primary lymphoma cells. We hypothesized that anti-CD47 antibody-mediated elimination of circulating tumor cells occurred through phagocytosis, a previously described mechanism for blocking anti-CD47 antibodies. As predicted, inhibition of dissemination by anti-CD47 antibodies was dependent on blockade of phagocyte SIRPα and required macrophage effector cells. These results demonstrate that CD47 is required for NHL dissemination, which can be therapeutically targeted with a blocking anti-CD47 antibody. Ultimately, these findings are potentially applicable to the dissemination and metastasis of other solid tumors.

CD137 stimulation enhances the antilymphoma activity of anti-CD20 antibodies.

Antibody-dependent cell-mediated cytotoxicity (ADCC), which is largely mediated by natural killer (NK) cells, is thought to play an important role in the efficacy of rituximab, an anti-CD20 monoclonal antibody (mAb) used to treat patients with B-cell lymphomas. CD137 is a costimulatory molecule expressed on a variety of immune cells after activation, including NK cells. In the present study, we show that an anti-CD137 agonistic mAb enhances the antilymphoma activity of rituximab by enhancing ADCC. Human NK cells up-regulate CD137 after encountering rituximab-coated tumor B cells, and subsequent stimulation of these NK cells with anti-CD137 mAb enhances rituximab-dependent cytotoxicity against the lymphoma cells. In a syngeneic murine lymphoma model and in a xenotransplanted human lymphoma model, sequential administration of anti-CD20 mAb followed by anti-CD137 mAb had potent antilymphoma activity in vivo. These results support a novel, sequential antibody approach against B-cell malignancies by targeting first the tumor and then the host immune system.

Prostate cancer immunotherapy: Improving clinical outcomes with a multi-pronged approach.

Cancer immunotherapy has gained traction in recent years owing to remarkable tumor clearance in some patients. Despite the notable success of immune checkpoint blockade (ICB) in multiple malignancies, engagement of the immune system for targeted prostate cancer (PCa) therapy is still in its infancy. Multiple factors contribute to limited response, including the heterogeneity of PCa, the cold tumor microenvironment, and a low number of neoantigens. Significant effort is being invested in improving immune-based PCa therapies. This review is a summary of the status of immunotherapy in treating PCa, with a discussion of multiple immune modalities, including vaccines, adoptively transferred T cells, and bispecific T cell engagers, some of which are undergoing clinical trials. In addition, this review also focuses on emerging mechanism-based small-molecule tyrosine kinase inhibitors with immune modulatory properties that, either as single agents or in combination with other immunotherapies, have the potential to improve clinical outcomes.

Preservation of Proteins in Human Plasma through Metal-Organic Framework Encapsulation.

Traditional cold chain systems of collection, transportation, and storage of biofluid specimens for eventual analysis pose a huge financial and environmental burden. These systems are impractical in pre-hospital and resource-limited settings, where refrigeration and electricity are not reliable or even available. Here, we develop an innovative technology using metal-organic frameworks (MOFs), a novel class of organic-inorganic hybrids with high thermal stability, as encapsulates for preserving the integrity of protein biomarkers in biofluids under ambient or non-refrigerated storage conditions. We encapsulate prostate-specific antigen (PSA) in whole patient plasma using hydrophilic zeolitic imidazolate framework-90 (ZIF-90) for preservation at 40 °C for 4 weeks and eventual on-demand reconstitution for antibody-based assays with recovery above 95% compared to storage at -20 °C. Without ZIF-90 encapsulation, only 10-30% of the PSA immunoactivity remained. Furthermore, we demonstrate encapsulation of multiple cancer biomarker proteins in whole patient plasma using ZIF-8 or ZIF-90 encapsulants for eventual on-demand reconstitution and analysis after 1 week at 40 °C. Overall, MOF encapsulation of patient biofluids is important as climate change may be affecting the stability and increase costs of maintaining biospecimen cold chain custody for the collection, transportation, and storage of biospecimens prior to analysis or for biobanking regardless of any countries' affluence.