Inhibition of JNK Signaling Overcomes Cancer-Associated Fibroblast-Mediated Immunosuppression and Enhances the Efficacy of Immunotherapy in Bladder Cancer.

Currently, only 20-40% of cancer patients benefit from immune checkpoint inhibitors. Understanding the mechanisms underlying the immunosuppressive tumor microenvironment (TME) and characterizing dynamic changes in the immunological landscape during treatment are critical for improving responsiveness to immunotherapy. Here, we identified JNK signaling in cancer-associated fibroblasts (CAFs) as a regulator of the immunosuppressive tumor microenvironment. Single-cell RNA sequencing of bladder cancer treated with a JNK inhibitor revealed enhanced cytotoxicity and effector functions of CD8+ T cells. In untreated tumors, CAFs interacted frequently with CD8+ T cells and mediated their exhaustion. JNK inhibition abrogated the immunosuppression function of CAFs by downregulating the expression of TSLP, thereby restoring CD8+ T cell cytotoxicity. In addition, blockade of CAF-derived TSLP in combination with anti-PD1 treatment promoted tumor elimination by CD8+ T cells in vivo. Collectively, these results indicate that JNK signaling plays an important immunosuppressive role in the tumor microenvironment by promoting expression of TSLP in CAFs and suggest that inhibiting JNK signaling could be a promising immunotherapeutic strategy for cancer treatment.

Combined Inhibition of PI3K and STAT3 signaling effectively inhibits bladder cancer growth.

Bladder cancer is characterized by aberrant activation of the phosphatidylinositol-3-OH kinase (PI3K) signaling, underscoring the significance of directing therapeutic efforts toward the PI3K pathway as a promising strategy. In this study, we discovered that PI3K serves as a potent therapeutic target for bladder cancer through a high-throughput screening of inhibitory molecules. The PI3K inhibitor demonstrated a robust anti-tumor efficacy, validated both in vitro and in vivo settings. Nevertheless, the feedback activation of JAK1-STAT3 signaling reinstated cell and organoid survival, leading to resistance against the PI3K inhibitor. Mechanistically, the PI3K inhibitor suppresses PTPN11 expression, a negative regulator of the JAK-STAT pathway, thereby activating STAT3. Conversely, restoration of PTPN11 enhances the sensitivity of cancer cells to the PI3K inhibitor. Simultaneous inhibition of both PI3K and STAT3 with small-molecule inhibitors resulted in sustained tumor regression in patient-derived bladder cancer xenografts. These findings advocate for a combinational therapeutic approach targeting both PI3K and STAT3 pathways to achieve enduring cancer eradication in vitro and in vivo, underscoring their promising therapeutic efficacy for treating bladder cancer.

Responsiveness to Platelet Transfusions in Pediatric Patients with Thrombocytopenia: Incidence, Clinical Variables.

BACKGROUND: Refractoriness to platelet transfusion has not been adequately studied in pediatric patients with thrombocytopenia. Our objectives were: (1) to describe the practice of platelet transfusion in pediatric patients with thrombocytopenia of various etiologies; (2) to assess the responsiveness to platelet transfusions and clinical variables affecting platelet transfusions response; and (3) to evaluate incidence of PTR. METHODS: A retrospective study included pediatric patients with thrombocytopenia admitted to a tertiary children's hospital who received ≥ 1 platelet transfusion during hospitalization. Responsiveness was measured by corrected count increment (CCI), poor platelet transfusion response (PPTR), and platelet transfusion refractoriness (PTR). RESULTS: A total of 334 patients were eligible for the study and received 1,164 transfusions, with a median of 2 (IQR: 1 - 5) platelet transfusions. Patients admitted with hematologic malignancies had the highest median number of platelet transfusions (5, IQR: 4 - 10). The median CCI of 1,164 platelet post-transfusions was 17.0 (IQR: 9.4 - 24.6) and the incidence of PPTR was 11.9%. Patients admitted with ITP had the lowest median CCI (7.6, IQR: 1.0 - 12.5) and the highest incidence of PPTR (36.4%, 8/22). Older age of platelet components, low doses of platelet transfusion, increasing number of platelet transfusions (≥ 5), splenomegaly, bleeding, DIC, shock, ECMO supported, and HLA antibody-positive were independent risk factors for PPTR. Finally, the incidence of PTR was 11.4%. CONCLUSIONS: Practical experience of clinicians regarding the use of apheresis platelets in pediatric patients is determined. Highlight that PTR is not a low probability event when apheresis platelets are received in pediatric patients.

The characteristics of blood transfusion and analysis of preoperative factors associated with intraoperative blood transfusion in congenital heart surgery: a case-control study.

PURPOSE: Blood transfusion is a common and life-saving procedure in congenital heart surgery (CHS), and it is critical for patients to identify risk factors prior to surgery. Our objective is to conduct an analysis of the preoperative factors that influence blood use during CHS and to offer guidance on preoperative blood preparation. METHODS: A total of 1550 cases were retrospectively analyzed in our institution between May 2019 and June 2020. We determined whether to employ red blood cells (RBCs), platelets, and plasma as dependent variables; we treated the data from characteristics and laboratory tests as binary data, except for the Risk Adjustment for Congenital Heart Surgery (RACHS) methods as multinomial data, and finally taken into binary logistic regression analysis. RESULTS: The total amounts of transfused RBCs, platelets, and plasma were 850.5 U (N = 713, 46%), 159 U (N = 21, 1.4%), and 1374.2 U (N = 953, 61.5%), respectively. Multivariate analysis found age (OR 0.142, 95% CI 0.099-0.203, P < 0.001), weight (0.170, 0.111-0.262, P < 0.001) RACHS method (RACHS2 vs. RACHS1, 3.444, 2.521-4.704, P < 0.001; RACHS3 vs. RACHS1, 9.333, 4.731-18.412, P < 0.001; RACHS4 vs. RACHS1, 31.327, 2.916-336.546, P = 0.004), and hemoglobin (0.524, 0.315-0.871, P = 0.013) to be independent risk predictors of RBC transfused volume; age (9.911, 1.008-97.417, P = 0.049), weight (0.029, 0.003-0.300, P = 0.029), RACHS method (RACHS3 vs. RACHS1, 13.001, 2.482-68.112, P = 0.002; RACHS4 vs. RACHS1, 59.748, 6.351-562.115, P < 0.001) to be platelets; and age (0.488, 0.352-0.676, P < 0.001), weight (0.252, 0.164-0.386, P < 0.001), RACHS method (RACHS2 vs. RACHS1, 2.931, 2.283-3.764, P < 0.001; RACHS3 vs. RACHS1, 10.754, 4.751-24.342, P < 0.001), APTT (1.628, 1.058-2.503, P = 0.027), and PT (2.174, 1.065-4.435, P = 0.033) to be plasma. CONCLUSION: Although patients' age, weight, routine blood test, coagulation function, and protein levels should all be considered for preparing blood before CHS, the RACHS method is the most important factor influencing intraoperative blood transfused volume and should be considered first in clinical blood preparation.

JNK Signaling Promotes Bladder Cancer Immune Escape by Regulating METTL3-Mediated m6A Modification of PD-L1 mRNA.

The RNA N6-methyladenosine (m6A) writer methyltransferase-like 3 (METTL3) is upregulated in many types of cancer and promotes cancer progression by increasing expression of several oncogenes. Therefore, a better understanding of the mechanisms regulating METTL3 expression and the key targets of METTL3 in cancer cells could provide new therapeutic targets. In this study, we found that activated JNK signaling is associated with increased METTL3 expression in bladder cancer. Knockdown of JNK1 or administration of a JNK inhibitor impaired the binding of c-Jun with the METTL3 promoter, thereby decreasing the expression of METTL3 and global RNA m6A levels. Moreover, RNA m6A sequencing indicated enrichment of m6A in the 3'-UTR of immune checkpoint PD-L1 mRNA, which could be recognized by the m6A reader IGF2BP1 to mediate RNA stability and expression levels of PD-L1. Inhibition of JNK signaling suppressed m6A abundance in PD-L1 mRNA, leading to decreased PD-L1 expression. Functionally, METTL3 was essential for bladder cancer cells to resist the cytotoxicity of CD8+ T cells by regulating PD-L1 expression. Additionally, JNK signaling contributed to tumor immune escape in a METTL3-dependent manner both in vitro and in vivo. These data reveal the JNK/METTL3 axis as a mechanism of aberrant m6A modification and immune regulation in bladder cancer. SIGNIFICANCE: The identification of a novel m6A-dependent mechanism underlying immune system evasion by bladder cancer cells reveals JNK signaling as a potential target for bladder cancer immunotherapy.