m6A-Modified SNRPA Controls Alternative Splicing of ERCC1 Exon 8 to Induce Cisplatin Resistance in Lung Adenocarcinoma

The small molecule drug CBL0137 interferes with DNA damage repair and enhances the sensitivity of NK/T-Cell lymphoma to cisplatin

This study aimed to investigate the in vitro and in vivo antitumor effects and mechanisms of the small molecule anticancer drug CBL0137 in NK/T-cell lymphoma (NKTCL), as well as its efficacy when combined with chemotherapy or immunotherapy. Cell viability assays were performed to evaluate the inhibitory effect of CBL0137 on NKTCL cell proliferation in vitro. Flow cytometry was used to assess the effects of the drug on apoptosis and cell cycle progression. RNA sequencing (RNA-seq) was employed to explore the mechanism of action of CBL0137 in NKTCL, and Western blotting (WB) was used to validate the expression of related proteins. An in vivo xenograft model was used to confirm the antitumor activity of CBL0137. Additionally, immunohistochemistry analysis was conducted to further study tumor tissue. CBL0137 effectively inhibited the proliferation of NKTCL cells in vitro, induced apoptosis, and significantly blocked cell cycle progression. RNA-seq analysis revealed that CBL0137 exerts its antitumor effect primarily by interfering with DNA damage repair. In vivo experiments using xenografted mice confirmed the antitumor activity of CBL0137. CBL0137, when combined with PD-1 antibody, exhibits synergistic antitumor effects in mice, and its combination with cisplatin significantly enhances the sensitivity of NKTCL to cisplatin. CBL0137 inhibits DNA damage repair in NK/T-cell lymphoma and enhances its sensitivity to cisplatin.

A Nucleus-Targeting Ruthenium(II) Complex Induces DNA Condensation in Cisplatin-Resistant Tumor Cells

One of the conventional ways to eradicate tumor cells is to utilize chemotherapy agents, e.g., cisplatin, to induce DNA damage. However, DNA damage repair mechanisms can significantly limit the therapeutic efficacy of cisplatin. These mechanisms enable tumor cells to repair the DNA damage caused by the drug, leading to resistance. Cisplatin and similar drugs bind to specific DNA sites without significantly altering their conformation. As a result, DNA repair enzymes can still attach to and repair the damaged DNA. To address this issue, we designed four Ru(II) complexes (RuC3, RuC6, RuC9, and RuC12) with high positive charges of +8 valence and regulated their nuclear accumulation levels by adjusting the length of alkyl chains. RuC9 exhibits the highest nucleus accumulation level. DNA conformation was significantly altered by inducing DNA condensation through indiscriminately neutralizing the negative charge of the DNA backbone. This significant change prevents DNA-related enzymes from binding to DNA, ultimately leading to the efficient eradication of various tumor cell lines. To the best of our knowledge, it is the first work that kills tumor cells and overcomes cisplatin resistance through inducing DNA condensation.

PKMYT1 kinase ameliorates cisplatin sensitivity in osteosarcoma

Cisplatin (DDP) remains a cornerstone therapy for osteosarcoma (OS); however, pervasive resistance severely limits its clinical efficacy and worsens patient outcomes. Developing strategies to enhance the chemotherapeutic responsiveness of OS cells is therefore of critical importance. Here, we conducted a kinome-wide clustered regularly interspaced short palindromic repeats (CRISPR) screen, coupled with transcriptome sequencing, to identify regulators of DDP sensitivity. This approach revealed protein kinase membrane-associated tyrosine/threonine 1 (PKMYT1) as a key regulator of DDP sensitivity in OS. Subsequent analysis of patient-derived clinical specimens, along with in vitro functional assays, demonstrated that DDP treatment induces the activation of PKMYT1 in OS cells. Importantly, PKMYT1 silencing markedly enhances cellular sensitivity to DDP, indicating its role in promoting chemoresistance. Mechanistically, PKMYT1 induces phosphorylation of nucleophosmin 1 (NPM1) at the S260 site, which competitively impairs NPM1 SUMOylation. This modification interferes with the recruitment of essential DNA damage response factors, including breast cancer suppressor gene 1 (BRCA1), receptor-associated protein 80 (RAP80), and RADiation sensitive protein 51 (RAD51), ultimately affecting double-strand break (DSB) repair. Furthermore, the selective PKMYT1 inhibitor RP6306 was found to synergize with DDP, amplifying its cytotoxic effects in OS cells. Collectively, these findings highlight PKMYT1 as a promising therapeutic target and provide a rationale for combinatorial strategies to overcome DDP resistance in OS.

Alternative Splicing in Lung Adenocarcinoma: From Bench to Bedside

Lung adenocarcinoma (LUAD) is a highly heterogeneous tumor and the most prevalent pathological type of lung cancer. The alternative splicing (AS) of mRNA enables the generation of multiple protein products from a single gene. This is a tightly regulated process that significantly contributes to the proteome diversity in eukaryotes. Recent multi-omics studies have delineated the splicing profiles that underline LUAD tumorigenesis from initiation to metastasis. Such progress holds robust promise to facilitate the development of screening strategies and individualized therapies. Perturbed AS fosters the emergence of novel neoantigen resources and disturbances in the immune microenvironment, which allow new investigations into modulatory targets for LUAD immunotherapy. This review presents an update on the landscape of dysregulated splicing events in LUAD and the associated mechanisms and theranostic perspectives with unique insights into AS-based immunotherapy, such as Chimeric Antigen Receptor T cell therapy. These AS variants can be used in conjunction with current therapeutic modules in LUAD, allowing bench to bedside translation to combat this highly malignant cancer.