Enhancing anti-angiogenic immunotherapy for melanoma through injectable metal-organic framework hydrogel co-delivery of combretastatin A4 and poly(I:C).

The interplay between vascularization and macrophage-induced immune suppression plays a crucial role in melanoma treatment. In this study, we propose a novel combination approach to combat melanoma by simultaneously inhibiting tumor vascularization and enhancing macrophage-mediated anti-tumor responses. We investigate the potential of combining combretastatin A4 (CA4), a vascular-disrupting agent, with poly(I:C) (PIC), an immunostimulatory adjuvant. This combination approach effectively suppresses melanoma cell proliferation, disrupts vascularization, and promotes macrophage polarization towards the M1 phenotype for melanoma suppression. To facilitate efficient co-delivery of CA4 and PIC for enhanced anti-angiogenic immunotherapy, we develop an injectable metal-organic framework hydrogel using Zeolitic Imidazolate Framework-8 (ZIF-8) and hyaluronic acid (HA) (ZIF-8/HA). Our findings demonstrate that ZIF-8 enables efficient loading of CA4 and enhances the stability of PIC against RNAase degradation in vitro. Furthermore, the developed co-delivery hydrogel system, PIC/CA4@ZIF-8/HA, exhibits improved rheological properties, good injectability and prolonged drug retention. Importantly, in vivo experiments demonstrate that the PIC/CA4@ZIF-8/HA formulation significantly reduces the dosage and administration frequency while achieving a more pronounced therapeutic effect. It effectively inhibits melanoma growth by suppressing angiogenesis, destroying blood vessels, promoting M1 macrophage infiltration, and demonstrating excellent biocompatibility. In conclusion, our study advances anti-angiogenic immunotherapy for melanoma through the potent combination of PIC/CA4, particularly when administered using the PIC/CA4@ZIF-8/HA formulation. These findings provide a new perspective on clinical anti-angiogenic immunotherapy for melanoma, emphasizing the importance of targeting tumor vascularization and macrophage-mediated immune suppression simultaneously.

A-to-I edited miR-154-p13-5p inhibited cell proliferation and migration and induced apoptosis by targeting LIX1L in the bladder cancer.

With the advancement of RNA sequencing technology, there has been a drive to uncover and elucidate the pivotal role of A-to-I RNA editing events in tumorigenesis. However, A-to-I miRNA editing events have been clearly identified in bladder cancer, the molecular mechanisms underlying their role in bladder cancer remain unclear. In our investigation, we observed a notable under-expression of edited miR-154-p13-5p in bladder cancer (BC) tissues, in contrast to normal counterparts. Remarkably, heightened expression levels of edited miR-154-p13-5p correlated with improved survival outcomes. To assess the impact of modified miR-154-p13-5p, we conducted a string of cell phenotype assays through transfection of the corresponding miRNAs or siRNAs. The results unequivocally demonstrate that edited miR-154-p13-5p exerts a substantial inhibitory influence on proliferation, migration, and induces apoptosis by specifically targeting LIX1L in bladder cancer. Moreover, we observed that the editing of miR-154-p13-5p or LIX1L-siRNAs inhibits the expression of LIX1L, thereby suppressing EMT-related proteins and cell cycle protein CDK2. Simultaneously, an upregulation in the expression levels of Caspase-3 and Cleaved Caspase-3 were also detected. Our research findings suggest that the upregulation of edited miR-154-p13-5p could potentially enhance the prognosis of bladder cancer, thereby presenting molecular biology-based therapeutic strategies.

Decitabine suppresses MDSC-induced immunosuppression through dual functional mechanism and inhibits melanoma metastasis.

Myeloid-derived suppressor cells (MDSCs) play a crucial role in promoting melanoma metastasis. Reprogramming MDSCs into mature M1 macrophages has emerged as a strategy to inhibit metastasis. Decitabine (Dec) is known to eradicate MDSCs and suppress tumor growth. In this study, we provide evidence that Dec not only reduces the MDSC population by inducing apoptosis, arresting cell cycle, and impairing recruitment, but also suppresses their immunosuppressive function by downregulating related genes and facilitating differentiation into M1 macrophages. Transcriptomic analysis of Dec-treated MDSCs revealed a marked downregulation of immunosuppressive genes including S100a9, S100a8, Vegf, Cxcr2, and Nos2. Meanwhile, M1 macrophage-associated genes involved in immune activation were upregulated, such as Ddx58, Isg15, Tap1, Ccl5, Cxcl9, and Cxcl10. Further bioinformatic analysis indicated that Dec promotes MDSC-to-M1 macrophage differentiation and activates innate immune pathways including NOD-like signaling to enhance anti-tumor immunity. Time-course studies implied that Dec upregulates myeloid transcription factor Irf7 to initiate MDSC differentiation and orchestrate the anti-tumor immune response. Collectively, our study unveils a novel dual-functional mechanism of Dec as both a cytotoxic agent reducing MDSCs and an inducer of their differentiation into M1 macrophages, thereby alleviating immunosuppression. This highlights Dec's potential for clinical melanoma metastasis suppression.

Immunologically active ferumoxytol-poly(I : C) nanomaterials inhibit metastatic melanoma by regulating myeloid-derived suppressor cell differentiation.

Nanomaterials have been identified as a potential therapeutic option for targeting myeloid-derived suppressor cells (MDSCs), which are known to play a crucial role in tumor metastasis and treatment resistance. Here, we report a unique immunologically active nanomaterial composed of ferumoxytol and poly(I : C) (FP-NPs) and investigate its immunoregulatory activities on MDSCs in metastatic melanoma. In vivo assays demonstrated that FP-NPs had the ability to significantly impede the progression of metastatic melanoma and decrease the MDSC population in the lungs, spleen, and bone marrow of mice. Both in vivo and in vitro experiments revealed that FP-NPs reduced the number of granulocytic MDSCs and promoted the differentiation of monocytic MDSCs into anti-tumor M1 macrophages. Transcriptome sequencing indicated that FP-NPs significantly altered the expression of several genes involved in immunity. Analysis of Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and quantitative real-time PCR revealed that FP-NPs significantly increased the expression of the myeloid cell differentiation-related gene interferon regulatory factor 7 and activated interferon beta-related signaling pathways, which stimulated the differentiation of MDSCs into M1 macrophages. These findings suggest that FP-NPs, a unique nanomaterial with immunological properties, can induce MDSCs to differentiate into M1 macrophages, potentially offering new treatment prospects for metastatic melanoma in the future.

Lutetium Lu 177 vipivotide tetraxetan for prostate cancer.

On March 23, 2022, the U.S. Food and Drug Administration (FDA) approved Pluvicto (lutetium Lu 177 vipivotide tetraxetan), also known as 177Lu-PSMA-617, for the treatment of adult patients with metastatic castration-resistant prostate cancer (mCRPC) who have highly expressed prostate-specific membrane antigen (PSMA) and have at least one metastatic lesion. It is the first FDA-approved targeted radioligand therapy for eligible men with PSMA-positive mCRPC. Lutetium Lu 177 vipivotide tetraxetan is a radioligand that strongly binds to PSMA, making it ideal for treating cancers of the prostate by targeted radiation, resulting in DNA damage and cell death. PSMA is overexpressed in cancer cells while being lowly expressed in normal tissues, which makes it an ideal theranostic target. As precision medicine advances, this is a thrilling turning point for highly individualized treatments. This review aims to summarize the pharmacology and clinical studies of the novel drug lutetium Lu 177 vipivotide tetraxetan for the treatment of mCRPC, emphasizing its mechanism of action, pharmacokinetics and safety.

Targeted delivery of nuclear targeting probe for bladder cancer using cyclic pentapeptide c(RGDfK) and acridine orange.

PURPOSE: Both cyclic pentapeptide c(RGDfK) and acridine orange (AO) exhibit antitumor effects and cell permeability. This study aimed to evaluate the nuclear targeting efficiency and safety of the nuclear targeting probe for bladder cancer (BCa) synthesized by c(RGDfK) and AO. METHODS: The nuclear targeting probe AO-(cRGDfK)2 was synthesized from AO hydrochloride, azided c(RGDfK), and a near-infrared skeleton synthesized via click chemistry reactions. The effect of the AO-(cRGDfK)2 probe on cell viability was assessed in BCa 5637 cells. The tumor cell targeting efficacy of the AO-(cRGDfK)2 probe was evaluated in BCa cells in vitro and in tumor-bearing mice in vivo. Nuclear-specific accumulation of fluorescence probe in BCa tumor cells was evaluated using laser scanning confocal microscopy (LSCM). Hematoxylin and eosin staining was performed to detect histopathological changes in the spleen, heart, liver, and kidney. RESULTS: The AO-(cRGDfK)2 probe did not cause a significant reduction in cell viability. LSCM analysis showed that AO-(cRGDfK)2 exhibited nuclear-specific ambulation in BCa cells and was not accumulated in 293T cells. Also, this probe efficiently targeted tumor cells in the serum and urine samples. In vivo imaging system of tumor-bearing mice showed that ~ 80% percent of fluorescence signal was accumulated in the tumor sites. The probe did not change histopathology in the heart, liver, spleen, and kidney in tumor-bearing mice after the 21-day treatment. CONCLUSIONS: The AO-(cRGDfK)2 probe exhibited nuclear-specific accumulation in BCa cells without cytotoxicity, which provides an innovative alternative to improve anticancer therapy for BCa.