Neutralizing IL-8 potentiates immune checkpoint blockade efficacy for glioma.

Malignant gliomas are largely refractory to immune checkpoint blockade (ICB) therapy. To explore the underlying immune regulators, we examine the microenvironment in glioma and find that tumor-infiltrating T cells are mainly confined to the perivascular cuffs and express high levels of CCR5, CXCR3, and programmed cell death protein 1 (PD-1). Combined analysis of T cell clustering with T cell receptor (TCR) clone expansion shows that potential tumor-killing T cells are mainly categorized into pre-exhausted/exhausted and effector CD8+ T subsets, as well as cytotoxic CD4+ T subsets. Notably, a distinct subpopulation of CD4+ T cells exhibits innate-like features with preferential interleukin-8 (IL-8) expression. With IL-8-humanized mouse strain, we demonstrate that IL-8-producing CD4+ T, myeloid, and tumor cells orchestrate myeloid-derived suppressor cell infiltration and angiogenesis, which results in enhanced tumor growth but reduced ICB efficacy. Antibody-mediated IL-8 blockade or the inhibition of its receptor, CXCR1/2, unleashes anti-PD-1-mediated antitumor immunity. Our findings thus highlight IL-8 as a combinational immunotherapy target for glioma.

Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging for Monitoring the Immune Response of Immunogenic Chemotherapy.

Objective: To evaluate the predictive value of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in the quantitative assessment of conventional chemotherapy-activated immune responses in mouse tumor models and clinics. Methods: A total of 19 subcutaneous tumor-bearing mice were randomly divided into treated and control groups. Both groups had orderly IVIM DWI examinations before and on days 6 and 12 after the administration of cyclophosphamide (CPA) or saline. Pathologic examinations were performed, including HE staining and immunohistochemistry (IHC). The expressions of immune-related genes in the tumor were measured by qPCR. In addition, six patients with breast cancer requiring neoadjuvant chemotherapy (NACT) also underwent functional MRI examinations and IHC to determine potential antitumor immune response. Results: At the end of the study, the CPA treatment group showed the lowest tumor volume compared to the control group. For pathological examinations, the CPA treatment group showed a lower percentage of CD31 staining (P < 0.01) and Ki-67 staining (P<0.01), and a higher percentage of TUNEL staining (P < 0.01). The tumoral pseudodiffusion coefficient (D*) value showed a positive correlation with the CD31-positive staining rate (r = 0.729, P < 0.0001). The diffusion related parameters (D) value was positively correlated with TUNEL (r = 0.858, P < 0.0001) and negatively correlated with Ki-67 (r = -0.904, P < 0.0001). Moreover, a strong induction of the expression of the immune responses in the CPA treatment group was observed on day 12. D values showed a positive correlation with the Ifnb1-, CD8a-, Mx1-, Cxcl10- (r = 0.868, 0.864, 0.874, and 0.885, respectively, P < 0.0001 for all). Additionally, the functional MRI parameters and IHC results in patients with breast cancer after NACT also showed a close correlation between D value and CD8a (r = 0.631, P = 0.028). Conclusions: The treatment response induced by immunogenic chemotherapy could be effectively evaluated using IVIM-DWI. The D values could be potential, sensitive imaging marker for identifying the antitumor immune response initiated by immunogenic chemotherapy.

METTL3 promotes cell cycle progression via m6A/YTHDF1-dependent regulation of CDC25B translation.

The cell cycle machinery controls cell proliferation and the dysregulation of the cell cycle lies at the heart of carcinogenesis. Thus, exploring the unknown regulators involved in the cell cycle not only contribute to better understanding of cell proliferation but also provide substantial improvement to cancer therapy. In this study, we identified that the expression of methyltransferase METTL3 was upregulated in the M phase. Overexpression of METTL3 facilitated cell cycle progression, induced cell proliferation in vitro and enhanced tumorigenicity in vivo, while knockdown of METTL3 reversed these processes. METTL3 induced CDC25B mRNA m6A modification in the M phase, which accelerated the translation of CDC25B mRNA through YTHDF1-dependent m6A modification. Clinical data analysis showed that METTL3 and CDC25B were highly expressed in cervical cancer. Our work reveals that a new mechanism regulates cell cycle progression through the METTL3/m6A/CDC25B pathway, which provides insight into the critical roles of m6A methylation in the cell cycle.

Intranasal Delivery of Immunotherapeutic Nanoformulations for Treatment of Glioma Through in situ Activation of Immune Response.

PURPOSE: Some chemotherapeutics have been shown to induce both the release of damage-associated molecular patterns (DAMPs) and the production of type I interferon (IFN-I), leading to immunogenic cell death (ICD). However, the standard chemotherapy drug for glioma, temozolomide (TMZ), cannot induce ICD as it cannot activate IFN-I signaling. Moreover, inefficient delivery of immunostimulants across the blood-brain barrier (BBB) is the main obstacle to overcome in order to induce local immune responses in the brain. METHODS: A new oligonucleotide nanoformulation (Au@PP)/poly(I:C)) was constructed by coating gold nanoparticles (AuNPs) with methoxypolyethylene glycol (mPEG)-detachable (d)-polyethyleneimine (PEI) (Au@PP) followed by inducing the formation of electrostatic interactions with polyinosinic-polycytidylic acid (poly(I:C)). Intracranial GL261 tumor-bearing C57BL/6 mice were used to explore the therapeutic outcomes of Au@PP/poly(I:C) plus TMZ in vivo. The anti-tumor immune response in the brain induced by this treatment was analyzed by RNA sequencing and immunohistochemical analyses. RESULTS: Au@PP/poly(I:C) induced IFN-I production after endocytosis into glioma cells in vitro. Additionally, Au@PP/poly(I:C) was efficiently accumulated in the glioma tissue after intranasal administration, which allowed the nanoformulation to enter the brain while bypassing the BBB. Furthermore, Au@PP/poly(I:C) plus TMZ significantly improved the overall survival of the tumor-bearing mice compared with group TMZ only. RNA sequencing and immunohistochemical analyses revealed efficient immune response activation and T lymphocyte infiltration in the Au@PP/poly(I:C) plus TMZ group. CONCLUSION: This study demonstrates that intranasal administration of Au@PP/poly(I:C) combined with TMZ induces ICD, thereby stimulating an in situ immune response to inhibit glioma growth.

Schisandrin B attenuates renal fibrosis via miR-30e-mediated inhibition of EMT.

Tubulointerstitial fibrosis (TIF) is the main pathologic feature of end-stage renal disease. Epithelial-mesenchymal transition (EMT) of proximal tubular cells (PTCs) is one of the most significant features of TIF. MicroRNAs play critical roles during EMT in TIF. However, whether miRNAs can be used as therapeutic targets in TIF therapy remains undetermined. We found that miR-30e, a member of the miR-30 family, is deregulated in TGF-ß1-induced PTCs, TIF mice and human fibrotic kidney tissues. Moreover, transcription factors that induce EMT, such as snail, slug, and Zeb2, were direct targets of miR-30e. Using a cell-based miR-30e promoter luciferase reporter system, Schisandrin B (Sch B) was selected for the enhancement of miR-30e transcriptional activity. Our results indicate that Sch B can decrease the expression of snail, slug, and Zeb2, thereby attenuating the EMT of PTCs during TIF by upregulating miR-30e, both in vivo and in vitro. This study shows that miR-30e can serve as a therapeutic target in the treatment of patients with TIF and that Sch B may potentially be used in therapy against renal fibrosis.

MiR-30c regulates cisplatin-induced apoptosis of renal tubular epithelial cells by targeting Bnip3L and Hspa5.

As a common anticancer drug, cisplatin has been widely used for treating tumors in the clinic. However, its side effects, especially its nephrotoxicity, noticeably restrict the application of cisplatin. Therefore, it is imperative to investigate the mechanism of renal injury and explore the corresponding remedies. In this study, we showed the phenotypes of the renal tubules and epithelial cell death as well as elevated cleaved-caspase3- and TUNEL-positive cells in rats intraperitoneally injected with cisplatin. Similar cisplatin-induced cell apoptosis was found in HK-2 and NRK-52E cells exposed to cisplatin as well. In both models of cisplatin-induced apoptosis in vivo and in vitro, quantitative PCR data displayed reductions in miR-30a-e expression levels, indicating that miR-30 might be involved in regulating cisplatin-induced cell apoptosis. This was further confirmed when the effects of cisplatin-induced cell apoptosis were found to be closely correlated with alterations in miR-30c expression, which were manipulated by transfection of either the miR-30c mimic or miR-30c inhibitor in HK-2 and NRK-52E cells. Using bioinformatics tools, including TargetScan and a gene expression database (Gene Expression Omnibus), Adrb1, Bnip3L, Hspa5 and MAP3K12 were predicted to be putative target genes of miR-30c in cisplatin-induced apoptosis. Subsequently, Bnip3L and Hspa5 were confirmed to be the target genes after determining the expression of these putative genes following manipulation of miR-30c expression levels in HK-2 cells. Taken together, our current experiments reveal that miR-30c is certainly involved in regulating the renal tubular cell apoptosis induced by cisplatin, which might supply a new strategy to minimize cisplatin-induced nephrotoxicity.