The ELAVL3/MYCN positive feedback loop provides a therapeutic target for neuroendocrine prostate cancer.

Neuroendocrine prostate cancer is a rapidly progressive and lethal disease characterized by early visceral metastasis, poor prognosis, and limited treatment options. Uncovering the oncogenic mechanisms could lead to the discovery of potential therapeutic avenues. Here, we demonstrate that the RNA-binding protein ELAVL3 is specifically upregulated in neuroendocrine prostate cancer and that overexpression of ELAVL3 alone is sufficient to induce the neuroendocrine phenotype in prostate adenocarcinoma. Mechanistically, ELAVL3 is transcriptionally regulated by MYCN and subsequently binds to and stabilizes MYCN and RICTOR mRNA. Moreover, ELAVL3 is shown to be released in extracellular vesicles and induce neuroendocrine differentiation of adenocarcinoma cells via an intercellular mechanism. Pharmacological inhibition of ELAVL3 with pyrvinium pamoate, an FDA-approved drug, effectively suppresses tumor growth, reduces metastatic risk, and improves survival in neuroendocrine prostate cancer mouse models. Our results identify ELAVL3 as a critical regulator of neuroendocrine differentiation in prostate cancer and propose a drug repurposing strategy for targeted therapies.

Clinical outcomes of immune checkpoint inhibitor plus nab-paclitaxel in metastatic upper tract urothelial carcinoma.

Background: Metastatic upper tract urothelial carcinoma (mUTUC) is a malignant cancer associated with poor prognosis. Few studies have investigated the clinical outcome of a recently developed combination regimen of programmed cell death 1 (PD-1) inhibitor plus nab-paclitaxel in mUTUC. Methods: We retrospectively retrieved data from the electronic medical records of cisplatin-ineligible or cisplatin-refractory mUTUC patients from five participating Chinese centers, who received treatment of PD-1 inhibitor plus nab-paclitaxel between April 2018 and January 2022. Clinical response was assessed according to Response Evaluation Criteria in Solid Tumors criteria version 1.1 (RECIST 1.1). Duration of response (DOR), overall survival (OS), and progression-free survival (PFS) were evaluated by the Kaplan-Meier method. Results: The confirmed overall response rate (ORR) was 14/34 (41.2%), and the disease control rate (DCR) was 24/34 (70.6%). Complete response (CR) was achieved in one case, partial response (PR) in 13 cases (38.2%), stable disease (SD) in 10 cases (29.4%), and progressive disease (PD) occurred in 10 cases (29.4%). After a median follow-up period of 16.0 months [95% confidence interval (CI): 9.9-22.1], 14 deaths were reported, with a median OS of 15.0 months (95% CI: 9.9-20.1); 22 progressions were reported, with a median PFS of 6.0 months (95% CI: 2.4-9.6). Patients with visceral metastasis had a similar PFS [hazard ratio (HR): 1.28, 95% CI: 0.53-3.09, P=0.574) and OS (HR: 1.94, 95% CI: 0.64-5.83, P=0.279] to patients with lymph node metastasis only. Conclusions: This real-world study suggests that PD-1 inhibitor plus nab-paclitaxel is effective in cisplatin-ineligible and cisplatin-refractory mUTUC patients with acceptable toxicity, especially for patients with visceral metastasis.

Comparative analysis of salvage partial nephrectomy versus radical nephrectomy after the failure of initial partial nephrectomy.

OBJECTIVES: To compare the oncologic outcomes and renal function discrepancy of salvage partial nephrectomy (sPN) and salvage radical nephrectomy (sRN) after an initial failed PN. MATERIALS AND METHODS: Retrospective data from multiple centers between 2008 and 2022 were analyzed in this study. Patients who received sPN or sRN after an initial failed PN were identified. Comparative analysis and propensity score matching (PSM) was performed and the RENAL score, tumor size, and pathological T stage at salvage surgery were used to match the 2 groups. Local recurrence-free survival (LRFS) and recurrence-free survival (RFS) were assessed using the Cox proportional hazards model and log-rank tests. Renal function after salvage surgery was assessed using the Wilcoxon rank sum test. RESULTS: A total of 140 patients who underwent salvage surgery were evaluated, of whom 60 were considered for PSM analysis after matching. At a median follow-up of 27.0 months, LRFS and RFS showed no significant difference between sPN and sRN, either before (LRFS, HR = 0.673 [95% CI: 0.171-2.644], P = 0.610; RFS, HR = 0.744 [95% CI: 0.271-1.344], P = 0.595) or after matching (LRFS, HR = 1.080 [95% CI: 0.067-17.30], P = 0.957; RFS, HR = 1.199 [95% CI: 0.241-5.983], P = 0.822). During long-term follow-up, sPN preserved renal function (after matching, eGFR, 71.4 vs. 54.0, P < 0.001) and prevented eGFR loss (after matching: 6.6% vs. 25.6%, P < 0.001). CONCLUSION: Salvage partial nephrectomy offers a better alternative than sRN for recurrence after initial PN, as sPN preserves renal function better while maintaining parallel tumor control and acceptable complication rates.

18 F-FDG PET/CT imaging in neuroendocrine prostate cancer: Relation to histopathology and prognosis.

BACKGROUND: This study aimed to evaluate the effectiveness of 18 F-fluoro-2-deoxy-D-glucose Positron emission tomography/computed tomography (18 F-FDG PET/CT) in predicting prognosis and characterizing the intratumoral glucose uptake of neuroendocrine prostate cancer (NEPC). METHODS: We retrospectively reviewed 189 NEPC patients from two medical centers between January 2009 and April 2021. Of these, 44 patients met the inclusion criteria. The maximum standardized uptake value (SUVmax) was measured to assess the metabolic state of NEPC and comparison were made between different histopathological subtypes. Kaplan-Meier and Cox regression analyses were performed to evaluate the predictive value of SUVmax on overall survival (OS) and progression-free survival (PFS). RESULTS: This study analyzed 44 NEPC patients and found that 13 patients had small cell neuroendocrine carcinoma (SCNC), while 31 were diagnosed with adenocarcinoma with neuroendocrine differentiation (Ad-NED) based on histopathology, and a positive correlation was found between SUVmax and SCNC via Spearman correlation test (rs = 0.60, p < 0.0001). Furthermore, SUVmax demonstrated good diagnostic accuracy in differentiating SCNC from Ad-NED (area under the curve 0.88, 95% confidence interval [CI] 0.76-0.99). Kaplan-Meier survival analyses and univariate analyses revealed that patients with SUVmax > 10.2 had a significantly shorter OS than patients with SUVmax ≤ 10.2 (hazard ratio = 4.83, 95% CI 1.45-16.1, p = 0.01). CONCLUSIONS: The histopathological subtypes in NEPC showed a close correlation with the glucose metabolic activity of primary tumors as assessed by 18 F-FDG PET/CT. High SUVmax values in primary prostate tumors were associated with a worse OS in NEPC patients.

Repurposing ketotifen as a therapeutic strategy for neuroendocrine prostate cancer by targeting the IL-6/STAT3 pathway.

PURPOSE: Neuroendocrine prostate cancer (NEPC), a highly aggressive subtype of prostate cancer displaying resistance to hormone therapy, presents a poor prognosis and limited therapeutic options. Here, we aimed to find novel medication therapies for NEPC and explore the underlying mechanism. METHODS: A high-throughput drug screening utilizing an FDA-approved drug library was performed and ketotifen, an antihistamine agent, was identified as a potential therapeutic candidate for NEPC. The whole-transcriptome sequencing analysis was conducted to explore mechanism of ketotifen inhibitory in NEPC. Multiple cell biology and biochemistry experiments were performed to confirm the inhibitory effect of ketotifen in vitro. A spontaneous NEPC mice model (PBCre4:Ptenf/f;Trp53f/f;Rb1f/f) was used to reveal the inhibitory effect of ketotifen in vivo. RESULTS: Our in vitro experiments demonstrated that ketotifen effectively suppressed neuroendocrine differentiation, reduced cell viability, and reversed the lineage switch via targeting the IL-6/STAT3 pathway. Our in vivo results showed that ketotifen significantly prolonged overall survival and reduced the risk of distant metastases in NEPC mice model. CONCLUSION: Our findings repurpose ketotifen for antitumor applications and endorse its clinical development for NEPC therapy, offering a novel and promising therapeutic strategy for this formidable cancer subtype.

Effectiveness and safety of immune checkpoint inhibitor monotherapy in advanced upper tract urothelial carcinoma: A multicenter, retrospective, real-world study.

INTRODUCTION: The effectiveness and safety of immune checkpoint inhibitor (ICI) monotherapy in advanced upper tract urothelial carcinoma (UTUC) is less reported. METHODS: In total, 106 consecutive advanced UTUC patients receiving ICI monotherapy were collected from nine high volume centers. Clinical outcomes were analyzed according to multiple parameters (e.g., treatment line, metastatic sites). Objective response rate (ORR), overall survival (OS) and progression-free survival (PFS) were captured after ICI initiation. RESULTS: With a median follow-up of 12.0 months, 25 patients in the first-line group and 15 patients in the second-line group died of UTUC. We reported a median OS of 18.0 months, a median PFS of 5.0 months, and an ORR of 38.6% for patients in the first-line group; a median OS of 10.0 months, a median OS of 4.0 months, and an ORR of 27.8% for patients in the second-line group. Complete response was observed in two patients in the first-line group and one patient in the second-line group with a total complete response rate of 2.8%. In the univariate and multivariate analysis, visceral metastasis with a hazard ratio of 2.4 was associate with poor OS. The most common treatment-related adverse events included fatigue (11.3%), pruritus (10.4%), and diarrhea (6.6%). CONCLUSIONS: This real-world study suggests that ICI monotherapy is active and has acceptable toxic effects for unresectable or metastatic UTUC as first-line therapy in cisplatin-ineligible patients or second-line therapy in platinum-refractory patients.

High-throughput drug screening identifies fluoxetine as a potential therapeutic agent for neuroendocrine prostate cancer.

Introduction: Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer with poor prognosis and resistance to hormone therapy, which has limited therapeutic approaches. Therefore, this study aimed to identify a novel treatment for NEPC and provide evidence of its inhibitory effects. Methods: We performed a high-throughput drug screening and identified fluoxetine, originally an FDA-approved antidepressant, as candidate therapeutic agent for NEPC. We carried out both in vitro and in vivo experiments to demonstrate the inhibitory effects of fluoxetine on NEPC models and its mechanism in detail. Results: Our results demonstrated that fluoxetine effectively curbed the neuroendocrine differentiation and inhibited cell viability by targeting the AKT pathway. Preclinical test in NEPC mice model (PBCre4: Ptenf/f; Trp53f/f; Rb1f/f) showed that fluoxetine effectively prolonged the overall survival and reduced the risk of tumor distant metastases. Discussion: This work repurposed fluoxetine for antitumor application, and supported its clinical development for NEPC therapy, which may provide a promising therapeutic strategy.

The efficacy and safety of first-line treatment in cisplatin-ineligible advanced upper tract urothelial carcinoma patients: a comparison of PD-1 inhibitor and carboplatin plus gemcitabine chemotherapy.

Although several programmed cell death (PD)-1 inhibitors are approved for the first-line treatment of advanced urothelial carcinoma, their efficacy remains unknown in cisplatin-ineligible patients with upper tract urothelial carcinoma (UTUC) compared with gemcitabine plus carboplatin. Data for patients with UTUC were retrospectively retrieved from the electronic medical records of nine institutions between 2018 and 2021. Patients considered ineligible for cisplatin who received either PD-1 inhibitors (n = 70) or gemcitabine plus carboplatin (n = 53) were included. Efficacy was assessed using Response Evaluation Criteria in Solid Tumors. Median progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The objective response rate (ORR) was comparable between the PD-1 inhibitor and carboplatin-gemcitabine groups (38.6% versus 41.5%). Median PFS was 5.0 months (95% confidence interval [CI]: 2.0-8.0) in the PD-1 inhibitor group, versus 7.0 months (95% CI: 5.8-8.2) in the carboplatin-gemcitabine group (hazard ratio [HR] = 0.741, 95% CI: 0.485-1.132, p = .166). Median OS was 18 months (95% CI: 4.1-31.9) in the PD-1 inhibitor group, compared with 14 months (95% CI: 12.1-15.9) in the carboplatin-gemcitabine group (HR = 0.731, 95% CI: 0.426-1.256, p = .257). The duration of response was significantly longer in the PD-1 inhibitor group than in the carboplatin-gemcitabine group (not reached vs. 9 months, p < .001). Treatment-related adverse events were less frequent in the PD-1 inhibitor group than in the carboplatin-gemcitabine group (57.1% vs. 77.3%). In conclusion, PD-1 inhibitors displayed promising efficacy with less toxicity and longer DOR in the first-line treatment of UTUC in patients ineligible for cisplatin-based chemotherapy.

Comprehensive analysis of androgen receptor status in prostate cancer with neuroendocrine differentiation.

The androgen receptor (AR) signaling is a key contributor to tumorigenesis and the progression of prostate cancer. A subset of patients may develop neuroendocrine (NE) features, resulting in resistance to androgen deprivation therapy and poor prognosis. In this study, we combined immunostaining and bulk and single-cell transcriptome analyses to better characterize the status of AR in prostate cancer with neuroendocrine differentiation. The exploration of online datasets indicated the existence of ARHIGH/NEHIGH prostate cancer and revealed that these double-high cases are majorly present in castration-resistant prostate cancer with a less neuroendocrine-transdifferentiated state. We then reviewed 8,194 prostate cancer cases with available immunohistochemistry reports and found 2.3% cases (n = 189) that showed at least one of the NE markers (chromogranin A, synaptophysin, and neural cell adhesion molecule 1) being positive in at least 5% of epithelial cells. Within these 189 cases, we observed that 81.0% cases (n = 153) showed AR positive and 19.0% (n = 36) showed AR negative. Patients with AR loss tumors demonstrated a correlation with adverse clinical stages, indicating a trade-off between AR and advanced disease in neuroendocrine differentiation. Using multiplex immunofluorescence staining, we observed the co-localization of AR and NE markers in prostate cancer cells. In addition, data mining of single-cell transcriptome further confirmed the existence of ARHIGH/NEHIGH prostate cancer cells in castration-resistant samples and suggested that AR still exerts its androgen response and anti-apoptotic effect in these double-high cells. Thus, our study provides a better understanding of AR signaling in the cellular plasticity of prostate cancer with neuroendocrine differentiation and allows new insights into the therapeutic development.

Docetaxel remodels prostate cancer immune microenvironment and enhances checkpoint inhibitor-based immunotherapy.

Background: Prostate cancer is usually considered as immune "cold" tumor with poor immunogenic response and low density of tumor-infiltrating immune cells, highlighting the need to explore clinically actionable strategies to sensitize prostate cancer to immunotherapy. In this study, we investigated whether docetaxel-based chemohormonal therapy induces immunologic changes and potentiates checkpoint blockade immunotherapy in prostate cancer. Methods: We performed transcriptome and histopathology analysis to characterize the changes of prostate cancer immune microenvironment before and after docetaxel-based chemohormonal therapy. Furthermore, we investigated the therapeutic benefits and underlying mechanisms of chemohormonal therapy combined with anti-PD1 blockade using cellular experiments and xenograft prostate cancer models. Finally, we performed a retrospective cohort analysis to evaluate the antitumor efficacy of anti-PD1 blockade alone or in combination with docetaxel-based chemotherapy. Results: Histopathology assessments on patient samples confirmed the enrichment of tumor-infiltrating T cells after chemohormonal therapy. Moreover, we found that docetaxel activated the cGAS/STING pathway in prostate cancer, subsequently induced IFN signaling, resulting in lymphocytes infiltration. In a xenograft mouse model, docetaxel-based chemohormonal therapy prompted the intratumoral infiltration of T cells and upregulated the abundance of PD1 and PD-L1, thereby sensitizing mouse tumors to the anti-PD1 blockade. To determine the clinical significance of these results, we retrospectively analyzed a cohort of 30 metastatic castration-resistant prostate cancer patients and found that docetaxel combined with anti-PD1 blockade resulted in better prostate-specific antigen progression-free survival when compared with anti-PD1 blockade alone. Conclusions: Our study demonstrates that docetaxel activates the antitumoral immune response and facilitates T cell infiltration in a cGAS/STING-dependent manner, providing a combination immunotherapy strategy that would improve the clinical benefits of immunotherapy.

Structure guided maturation of a novel humanized anti-HBV antibody and its preclinical development.

We have reported that E6F6, a mouse monoclonal antibody, is a promising treatment option for patients with chronic hepatitis B (CHB). A humanized E6F6 antibody B11 with affinity loss was obtained by CDR-grafting approach. To address this issue, in silico affinity maturation through scanning mutagenesis using CHARMM force field methods was performed on an predicted immune complex model of the B11:HBsAg. We chose four variants with top increased interaction energy for further characterization. The antibody huE6F6-1 within two point mutations (Heavy Chain: Asp65Val; His66Leu) was identified to restore the parental antibody's high binding affinity, neutralization activity, and potent efficacy of viral suppression in vivo. Crystal structure (1.8 Å resolution) based molecular docking proved more stabilized and compact hydrogen bond interactions formed in huE6F6-1.The smaller and dispersed HBV immune complexes of huE6F6-1 by electron microscopy suggested it will have the same therapeutic efficacy as the parental E6F6 mAb. Preclinical study and pharmacokinetics of huE6F6-1 demonstrated that it is a stable and desirable lead candidate to improve the clinical management of CHB. Notably, our structure guided approach may facilitate the humanization and affinity maturation of other rodent antibody candidates during drug development.

A bispecific broadly neutralizing antibody against enterovirus 71 and coxsackievirus A16 with therapeutic potential.

Enterovirus 71 (EV71) and coxsackievirus A16 (CA16) are the major pathogens of hand, foot and mouth disease (HFMD), which affects children worldwide and is often associated with neurological complications. At present, there is no vaccine or cure available for simultaneous EV71 and CA16 infection, posing a great need to develop novel strategies for the treatment of this disease. Here, we engineered four bispecific antibodies using variable fragments of monoclonal antibodies (mAbs) from EV71- and CA16-specific neutralizing antibodies. The engineered bispecific antibody Bs(scFv)4-IgG-1 exhibits remarkable cross-reactivity against EV71 and CA16 and has a more potent cross-neutralization than its parental antibodies. Furthermore, we showed that Bs(scFv)4-IgG-1 conferred 100% therapeutic efficacy against single or mixed EV71 and CA16 infections in mice. Our study provides important insights into bispecific antibody engineering against enterovirus and will inform new curative treatment options for HFMD.

Human cytomegalovirus vaccine development: Immune responses to look into vaccine strategy.

Human cytomegalovirus (HCMV) causes considerable morbidity and disability in high risk, immunocompromised populations including recipients of solid organ transplants, and fetuses whose immune systems are not yet mature. Vaccines aimed at ameliorating the severity of disease and preventing HCMV infection can be categorized into two main approaches of vaccine design, with one focusing on virus modification and the other on individual antigens. However, no candidates in either class have been successful in achieving durable and protective immunity. Recent studies on the natural immune response provide new insight into HCMV vaccine strategy. In particular, studies have demonstrated that the incorporation of a pentameric complex is necessary for a vaccine to generate the potent neutralizing antibodies often seen in seropositive individuals. This review summarizes recent findings in the development of HCMV vaccines and key considerations that should be taken into vaccine design based on improved understanding of natural HCMV immunity.