BAX x Bcl-2 x PARP x caspase 3

A series of pinane-based thiazolidione derivatives were synthesised, and their anti-proliferative effects were investigated by CCK-8 assay. All these compounds exhibited anti-proliferation activity against three glioblastoma cell lines (U87, T98G, and U251). Compound C5 exhibited the strongest inhibition effect against all three cell lines. Through cellular thermal shift (CETSA) assay and drug affinity responsive target stability (DARTS) assay, compound C5 was demonstrated to directly interact with the CDK2 protein. Additional analyses revealed that C5 inhibited cell migration and arrested the cell cycle in glioblastoma cells while also induced mitochondrial apoptosis and autophagy. Immunoblotting analysis indicated that C5 induced the up-regulation of Bax, cleaved caspase 3, cleaved PARP-1, P62, and LC3B, and the down-regulation of Bcl-2, caspase 3, and PARP-1. Importantly, C5 also demonstrated efficacy in a 3D cell culture model. Together, these results highlight the potential of C5 as a lead compound for the development of novel therapies for glioblastoma.

Fritillaria walujewii Regel (Xinjiang Bei-Mu), an authentic ("Dao-di") medicinal herb documented in Chinese pharmacopoeias, is traditionally used to treat respiratory disorders. Its principal steroidal alkaloid, peiminine (PMI), demonstrates significant anticancer activity. Oxaliplatin (Oxa), a first-line chemotherapeutic cornerstone for gastric cancer (GC), is limited clinically by intrinsic chemoresistance. Natural product-derived monomers represent a promising strategy for developing chemosensitizers to overcome such resistance. However, the potential of PMI to counteract Oxa chemoresistance and its underlying mechanisms remain unexplored, warranting comprehensive investigation. To determine the chemosensitizing effects of PMI in combination with Oxa for GC treatment, specifically evaluating its capacity to reverse chemoresistance and enhance therapeutic efficacy.

The effects of PMI combined with Oxa versus Oxa monotherapy on GC cells (HGC27, BGC823, MKN45) were assessed using CCK-8, colony formation, and flow cytometry apoptosis assays to evaluate cell proliferation and apoptosis. Subsequently, qPCR-based apoptosis pathway array and transcriptome sequencing (RNA-seq) were used to differentially expressed apoptosis-related genes and to uncover key signaling pathways mediating PMI-induced Oxa sensitization. The protein expression level of Bcl-2, Bax, PARP, cytochrome c (CYCS), Caspase-3/9, RAS and AKT was determined by Western blot. Finally, the efficacy of PMI+Oxa combination therapy was validated in vivo using both cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models.

PMI (50 μM) synergized with Oxa (2.5 μM), significantly enhancing apoptosis and suppressing proliferation in GC cells. Mechanistically, the combination activated the mitochondrial apoptosis pathway by upregulating Bax and inducing the release of CYCS and the cleavage of caspase-9, caspase-3, and PARP. Concurrently, it suppressed the RAS/PI3K/AKT survival pathway by inhibiting Ras-GTP and phospho-AKT. In CDX models, PMI (2 mg/kg) + Oxa achieved a tumor growth inhibition (TGI) rate of > 80.8 %, compared to 20.4 % for Oxa alone. Strikingly, in PDX models which preserve clinical tumor heterogeneity-the combination induced a TGI of > 70 % without exacerbating systemic toxicity.

PMI is a novel dual-targeting chemosensitizer that overcomes Oxa resistance by simultaneously activating intrinsic apoptosis and inhibiting pro-survival signaling. Its demonstrated efficacy in clinically relevant PDX models highlights its significant translational potential for platinum-resistant GC therapy.

Lung cancer remains a leading cause of cancer‐related mortality, underscoring the urgent need for more effective therapeutic strategies, particularly due to the frequent development of drug resistance. Paclitaxel, a widely used chemotherapeutic agent for non‐small cell lung cancer (NSCLC), often faces resistance that limits its clinical efficacy. Therefore, identifying molecular markers that modulate paclitaxel responsiveness is critical. The ubiquitin‐proteasome system (UPS), which regulates protein homeostasis, plays a role in cancer progression, apoptosis, and drug resistance, with deubiquitinating enzymes (DUBs), serving as key regulators. Recent studies suggest that targeting specific DUBs may enhance drug sensitivity. This study aimed to investigate the expression patterns of DUB genes in response to paclitaxel treatment. Multiplex RT‐PCR and RT‐qPCR analysis revealed that USP1, USP5, USP28, and USP34 were downregulated, whereas USP10 and USP36 were upregulated in paclitaxel‐treated A549 cells. Western blot analysis confirmed changes in protein levels consistent with mRNA expression for all DUBs except USP10 and USP36, which displayed discordant patterns. Furthermore, paclitaxel‐induced apoptosis was verified by altered levels of apoptotic and antiapoptotic proteins including PARP, caspase‐3, Bax, Bcl‐2, Bcl‐XL, and p53. The identification of these DUB genes highlights their potential as biomarkers for predicting drug responsiveness and prognosis during paclitaxel treatment, thereby proposing a new direction for improving the therapeutic efficacy of paclitaxel in NSCLC.