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.