The role of tumor-associated macrophages (TAMs) along with the regulatory mechanisms underlying distinct macrophage activation states remain poorly understood in prostate cancer (PCa). Herein, we reported that PCa growth in macrophage-specific Ubc9 deficient mice is substantially suppressed compared to their wild-type littermates, an effect partially ascribed to the augmented CD8⁺ T cell response. Biochemical and molecular analyses revealed that the signal transducer and activator of transcription 4 (STAT4) is a crucial UBC9-mediated SUMOylation target, with lysine residue 350 (K350) as the major modification site. Site-directed mutation of STAT4 (K350R) enhanced its nuclear translocation and stability, thereby facilitating the proinflammatory activation of macrophages. Importantly, administration of UBC9 inhibitor, 2-D08, promoted the antitumor effect of TAMs and increased the expression of PD-1 on CD8⁺ T cells, supporting a synergistic antitumor efficacy once it combined with the immune checkpoint blockade (ICB) therapy. Together, our results demonstrated that ablation of UBC9 could reverse the immunosuppressive phenotype of TAMs via promoting STAT4 mediated macrophage activation and macrophage-CD8⁺ T cell crosstalk, which provides valuable insights to halt the pathogenic process of tumorigenesis.

Background: Novel non-invasive biomarkers are urgently required to improve the diagnostic sensitivity and specificity of prostate cancer (PCa). Therefore, the diagnostic value of following candidate genes (ERG, PCA3, ARV7, PSMA, CK19, and EpCAM) were estimated by testing mRNAs from urinary exosomes of patients with primary PCa.Methods: Exosomes were obtained using size-exclusion chromatography (SEC), out of which RNAs were extracted, then analyzed by quantitative reverse transcription-polymerase chain reaction according to manufacturer’s protocol.Results: The expression of urinary exosomal ERG, PCA3, PSMA, CK19, and EpCAM were significantly increased in patients with PCa compared with healthy males. In addition, the levels of urinary exosomal ERG, ARV7, and PSMA were intimately correlated with the Gleason score in PCa patients (P < 0.05). The receiver operating characteristic curves (ROCs) showed that urinary exosomal ERG, PCA3, PSMA, CK19, and EpCAM were able to distinguish patients with PCa from healthy individuals with the area under the curve (AUC) of 0.782, 0.783, 0.772, 0.731, and 0.739, respectively. Urinary exosomal PCA3 and PSMA distinguished PCa patients from healthy individuals with an AUC of 0.870. Combination of urinary exosomal PCA3, PSMA with serum PSA and PI-RADS achieved higher AUC compared with PSA alone (0.914 and 0.846, respectively). Kaplan-Meier curves demonstrated that PCA3, ARV7, and EpCAM were associated in androgen-deprivation therapy (ADT) failure time which is defined as from the initiation of ADT in hormone-sensitive stage to the development of castration-resistant prostate cancer.Conclusion: These findings suggested that mRNAs from urinary exosomes have the potential in serving as novel and non-invasive indicators for PCa diagnosis and prediction.

Background: The clinical characteristics of coronavirus disease 2019 (COVID-19) have been well-studied, while effective predictors for clinical outcome and research on underlying mechanisms are scarce. Methods: Hospitalized COVID-19 pneumonia patients with definitive clinical outcome (cured or died) were retrospectively studied. The diagnostic performance of the leucocyte subsets and other parameters were compared using the area under the receiver operating characteristic curve (AUC). Further, the correlations between leucocyte subsets and inflammation-related factors associated with clinical outcome were subsequently investigated. Results: Among 95 subjects included, 56 patients were cured, and 39 died. Older age, elevated aspartate aminotransferase, total bilirubin, serum lactate dehydrogenase, blood urea nitrogen, prothrombin time, D-dimer, Procalcitonin, and C-reactive protein levels, decreased albumin, elevated serum cytokines (IL2R, IL6, IL8, IL10, and TNF-α) levels, and a decreased lymphocyte count indicated poor outcome in patients with COVID-19 pneumonia. Lymphocyte subset (lymphocytes, T cells, helper T cells, suppressor T cells, natural killer cells, T cells+B cells+NK cells) counts were positively associated with clinical outcome (AUC: 0.777; AUC: 0.925; AUC: 0.900; AUC: 0.902; AUC: 0.877; AUC: 0.918, resp.). The neutrophil-to-lymphocyte ratio (NLR), neutrophil to T lymphocyte count ratio (NTR), neutrophil percentage to T lymphocyte ratio (NpTR) effectively predicted mortality (AUC: 0.900; AUC: 0.905; AUC: 0.932, resp.). Binary logistic regression showed that NpTR was an independent prognostic factor for mortality. Serum IL6 levels were positively correlated with leucocyte count, neutrophil count, and eosinophil count and negatively correlated with lymphocyte count. Conclusion: These results indicate that leucocyte subsets predict the clinical outcome of patients with COVID-19 pneumonia with high efficiency. Non-self-limiting inflammatory response is involved in the development of fatal pneumonia.

Background: Immune checkpoint inhibitors (ICIs) are the standard of care for metastatic renal cell carcinoma (RCC); however, most patients develop de novo or acquired resistance to ICIs. Oxidative phosphorylation (OXPHOS) has been rarely explored as a potential target for correcting ICI resistance. Methods: We systematically analyzed RNA sequencing and clinical data from CheckMate, JAVELIN Renal 101, and NCT01358721 clinical trials, and clinicopathological data of 25 patients from Tongji Hospital to investigate the relationship between OXPHOS and ICI resistance. The Ndufb8-knockdown Renca cell line was derived to determine the effect of OXPHOS on RCC immunotherapy in vivo. Results: An analysis of the CheckMate series data revealed that high OXPHOS levels are risk factors for ICI in patients with RCC, but are affected by thevon Hippel-Lindau protein (VHL) and hypoxia-inducible factor-1α status. This result is consistent with correlation between clinicopathological characteristics and prognostic observations at our institute. Knockdown of the mitochondrial complex I subunit Ndufb8 of the Renca cell line had no effect on cell growth and migration in vitro, but slowed down cell growth in vivo. Among anti-programmed death ligand 1 (PD-L1)-treated BALB/c mice, shNdufb8 Renca tumors grew slower than shControl Renca tumors and the corresponding mice survived longer. Flow cytometry revealed that CD8⁺ T cells in shNdufb8 Renca tumors, which were exposed to a lower degree of hypoxia and expressed less programmed death-1 (PD-1) and T-cell immunoglobulin domain and mucin domain 3 (TIM-3), secreted more interferon-γ after stimulation. Immunofluorescence demonstrated that the shNdufb8 Renca tumors had a higher proportion of CD8⁺ T cells and the proportion of these cells was lower in the hypoxic area. Conclusions: OXPHOS is a reliable predictor of immunotherapy response in RCC and is more pronounced in metastatic lesions. RCC cells generate a hypoxic tumor microenvironment and inhibit T-cell function through oxidative metabolism, thereby leading to immunotherapy resistance.