Molecular Oncology最新文献

The spindle assembly checkpoint (SAC) delays the metaphase-to-anaphase transition. Aurora kinase A (AURKA) inactivation has been shown to cause premature exit from mitosis in the presence of an unsatisfied SAC. We report for the first time that centromeric AURKA interacts with survivin during prometaphase. Notably, depleting or inhibiting AURKA activity at this stage causes mislocalisation of the CPC and BubR1, which compromises the SAC and can lead to mitotic slippage. Furthermore, we show that AURKA binds directly to the BIR domain of survivin at a position distinct from AURKB and indirectly to it via its C terminus. We find the interaction peaks during prometaphase but persists into late mitosis. Importantly, we demonstrate that cells with high levels of survivin are particularly vulnerable to mitotic slippage induced by the AURKA inhibitor, MLN8237/ Alisertib. Alisertib enables both normal and transformed cells with high levels of survivin to activate the APC/C prematurely, as observed by the destruction of cyclin B and securin. Thus, a high expression of survivin can alter cell fate decisions at mitosis and lead to genetic instability, a key hallmark in cancer.

The detection of actionable mutations in liquid biopsies is a crucial tool for precision oncology in patients with non-small-cell lung cancer (NSCLC). We evaluated actionable alterations using a multigene panel in circulating tumor DNA (ctDNA) from Brazilian NSCLC patients. We analyzed 32 samples from 30 patients with NSCLC, including four samples from a lung cancer screening program. ctDNA isolation and library preparation were performed using the Oncomine Lung cfDNA Assay, which covers 11 actionable genes, and sequenced on an Ion S5 Sequencer. The IonReporter 5.20 software was used for variant calling. Median read coverage reached 80 967, with a detection limit of 0.1%. TP53 (40.6%), KRAS (28.1%), and EGFR (12.5%) were the most frequently mutated genes, particularly in patients who had previously received treatment. BRAF, MAP2K1, PIK3CA, and ALK mutations were observed at lower frequencies (6.2%, 3.1%, 3.1%, and 3.1%, respectively). The EGFR p.T790M mutations related to resistance were identified in a patient who had been previously treated, and the TP53 p.R248Q mutation was discovered in an asymptomatic patient before diagnosis. No variants were observed in NRAS, ROS1, and MET genes. Our data showed that this commercial NGS panel could detect actionable mutations, enabling early detection, treatment monitoring, and disease surveillance.

Hepatic fibrogenesis is characterized by the excessive accumulation of extracellular matrix proteins, ultimately predisposing to hepatocarcinogenesis. The lack of reliable models that faithfully recapitulate early stage fibrogenesis is one of the main limitations in identifying translationally relevant therapeutics. Here, we establish a model using CRISPR/Cas9-mediated TP53 knockout iPSC (endoderm)-derived human hepatic organoids (eHEPOs) to mimic human liver fibrosis. Transcriptomic profiling of TP53KO-eHEPOs revealed enrichment of pathways associated with inflammation, ECM remodeling, and fibrosis, with notable alterations in pivotal fibrotic regulators. We also find increased expression of myofibroblasts and fibrosis markers (PDGFRB, COL1A1, COL3A1, COL11A1) and early liver cancer markers (GPC3 and MUC1). Histological analysis confirmed advanced fibrotic hallmarks and exposure to an exogenous profibrotic environment (pf-ME) further enhanced these fibrotic phenotypes. This model provides a valuable platform for exploring the role of key driver genes, such as TP53, in the initiation and progression of fibrosis, enabling the study of hepatic progenitor cell transformation across diverse microenvironmental contexts. As such, it holds the potential for advancing early stage drug discovery and the identification of novel therapeutic targets for the treatment of liver fibrosis.

Bladder cancer incidence has recently risen, making it the ninth most diagnosed cancer, highlighting an urgent need for novel and effective diagnostic and therapeutic strategies to improve patient outcomes. Here, we report on a secreted glycoprotein, Galectin-3-binding protein (LGALS3BP), as a potential biomarker and therapeutic target for bladder cancer. We found a significantly elevated LGALS3BP expression in bladder cancer tissues, correlating with disease progression. Moreover, urinary and serum levels of LGALS3BP were significantly higher in patients compared to healthy individuals, with a strong correlation observed between elevated urinary protein levels and tumor grade. Of note, LGALS3BP produced by tumor cells treated with a mannosidase I inhibitor, Kifunensine, exhibited increased reactivity to a therapeutic antibody (denoted as "1959"), suggesting that glycosylation of LGALS3BP may influence antibody recognition and protein function. Furthermore, administration of 1959-sss/DM4 antibody-drug conjugate in two xenograft mouse models of human bladder cancer resulted in complete inhibition of tumor growth. In summary, findings presented here highlight LGALS3BP as a promising candidate for further investigation into its potential as a urinary biomarker and a therapeutic target for bladder cancer.

Genetic testing in epithelial ovarian cancer (EOC) in Ontario includes germline next-generation sequencing (NGS) for 19 genes. Additionally, tumor tissue undergoes reflex NGS testing for BRCA1/2 to assess eligibility for PARPi. Although parallel testing confers advantages, this model duplicates healthcare resources. Here, we prospectively assessed the feasibility of tumor-first multigene testing by comparing tumor tissue with germline testing of peripheral blood. An 18-gene NGS panel was used to test tumor and germline DNA (n = 106 patients). In 26 patients, 27 tumor Tier I or II variants were identified, with 16/27 (59%) being germline pathogenic variants (PV) (13 BRCA1/2; 3 other genes) and 11/27 (41%) somatic variants (9 BRCA1/2; 2 other). In 51/106 patients, there were no tumor variants (excluding TP53), of which one patient had a germline BRCA1 copy number variant deletion in exon 12. Tumor-first testing detected variant-positive and variant-negative germline cases in 105/106 patients (99.1%). Among 50 BRCA-negative patients, 14/50 (28%) were homologous recombination deficiency (HRD)-positive. Therefore, we demonstrate that multigene NGS tumor-testing is effective in identifying germline variants in EOC with a < 1% false-negative rate.

Targeted therapy has been established as a therapeutic option for the treatment of metastatic melanoma. Despite initially being very efficient, many tumors develop resistance to targeted therapy, leading to its failure. We previously demonstrated that the neural crest (NC)-associated gene ERRFI1 is highly expressed in metastatic melanoma and correlates with a bad prognosis. Here, we show that the expression of ERRFI1 was upregulated in melanoma and negatively correlated with the expression of melanocytic differentiation markers, such as MITF and TYR. Downregulation of ERRFI1 with the help of siRNA increased the susceptibility of melanoma cells toward BRAF inhibition (BRAFi) and resensitized BRAFi-resistant melanoma cells to BRAFi. Mass spectrometry-based proteomic analysis revealed that ERRFI1 silencing diminished the activation of the mitogen-activated protein kinase (MAPK) and AKT signaling pathways, which usually contribute to drug resistance. Furthermore, we show that miR-200c targeted the 3'UTR of ERRFI1 and reduced its expression, resulting in the resensitization of BRAFi-resistant melanoma cells to BRAFi. Our study results suggest that ERRFI1 could be a potential therapeutic target for the treatment of metastatic melanoma.

Circulating tumor cells (CTCs) play an important role in metastasis formation. Aberrant signaling of oncogenic pathways (e.g., PI3K/AKT/mTOR pathway) drives tumor progression. In this work, the susceptibility of the colon cancer CTC-derived cell line CTC-MCC-41 to AKT and mammalian target of rapamycin (mTOR) inhibitors was evaluated. Additionally, the functional role of the expressed AKT isoforms was characterized in this cell line. The efficacy of the AKT inhibitor MK2206, the mTOR inhibitor RAD001, and the combination was examined in CTC-MCC-41 cells in a murine intracardiac xenotransplantation model. Furthermore, stable isoform-specific AKT1 or AKT2 knockdowns (KDs) as well as AKT1/AKT2 double-KD cells were generated. Differentially regulated proteins and phospho-peptides were identified using liquid chromatography coupled mass spectrometry (LC-MS). CTC-MCC-41 cells showed a high susceptibility for dual targeting of AKT and mTOR in vivo, indicating that selective eradication of CTCs by AKT/mTOR inhibitors may be considered a new treatment option in cancer. KD of AKT1 or AKT2 significantly reduced the proliferation of CTC-MCC-41 cells. AKT KDs share commonly regulated proteins and phospho-proteins, but also regulate a large number uniquely. AKT1/AKT2 double-KD cells show a strongly dysregulated replication machinery, as well as a decrease in cell cycle activity and stem-cell-associated processes, underlining the non-redundant role of AKT isoforms.

Cell-free circulating tumor DNA (ctDNA) has emerged as a promising biomarker for response evaluation in metastatic castration-resistant prostate cancer (mCRPC). The current study evaluated the modified fast aneuploidy screening test-sequencing system (mFast-SeqS), a quick, tumor-agnostic and affordable ctDNA assay that requires a small input of DNA, to generate a genome-wide aneuploidy (GWA) score in mCRPC patients, and correlated this to matched metastatic tumor biopsies. In this prospective multicenter study, GWA scores were evaluated from blood samples of 196 mCRPC patients prior to treatment (baseline) with taxanes (docetaxel and cabazitaxel) and androgen receptor signaling inhibitors (ARSI; abiraterone and enzalutamide), and from 74 mCRPC patients at an early timepoint during treatment (early timepoint; median 21 days). Z-scores per chromosome arm were tested for their association with tumor tissue genomic alterations. We found that a high tumor load in blood (GWA^high) at baseline was associated with poor response to ARSI [HR: 2.63 (95% CI: 1.86-3.72) P < 0.001] but not to taxanes. Interestingly, GWA^high score at the early timepoint was associated with poor response to both ARSIs [HR: 6.73 (95% CI: 2.60-17.42) P < 0.001] and taxanes [2.79 (95% CI: 1.34-5.78) P = 0.006]. A significant interaction in Cox proportional hazards analyses was seen when combining GWA status and type of treatment (at baseline P = 0.008; early timepoint P = 0.018). In summary, detection of ctDNA in blood by mFast-SeqS is cheap, fast and feasible, and could be used at different timepoints as a potential predictor for outcome to ARSI and taxane treatment in mCRPC.

The relative failure of immune checkpoint inhibitors in pancreatic ductal adenocarcinoma (PDAC) despite having a dense, immunosuppressive tumor microenvironment highlights the need to target alternate/escape pathways. We have previously examined C-C chemokine receptor type 9 (CCR9) as a candidate immune checkpoint and developed a targeted, humanized monoclonal antibody (SRB2). Cytotoxicity of SRB2 was evaluated in vitro and in vivo. CCR9 expression on PDAC cells/tissues, immune components of patient-derived organoids (PDOs), and antibody-dependent cell-mediated cytotoxicity were examined. In PANC-1 and MIA PaCa-2 cell lines, we demonstrated highest CCR9 expression; however, no direct cytotoxic effect was observed with SRB2 treatment. In PANC-1 cells, NK cell-mediated cytotoxicity was promoted by SRB2. Dose-dependent SRB2 cytotoxicity was observed in PDAC PDOs. In patient-derived xenograft mouse models, cytotoxicity of SRB2 monotherapy and in combination with oxaliplatin was also shown. In humanized immune-competent mouse models, SRB2 efficacy was similar to other drugs, but two mice in this cohort had complete tumor regression. Our current studies suggest that therapeutic targeting of CCR9 may improve PDAC outcomes, and additional studies are underway to evaluate SRB2 for clinical use.

Medulloblastoma (MB) is the most common malignant tumor in the central nervous system in childhood and regularly metastasizes to the leptomeninges following radiation therapy. Using patient-derived medulloblastoma models and genetically engineered mouse models, Nör et al. observed enhanced inflammation and infiltration of myeloid cells within the brain following irradiation. The authors identified inflammatory cytokines and the resulting breakdown of blood-brain barriers as the main culprits of MB leptomeningeal metastasis. This study demonstrated that targeting inflammation through the use of dexamethasone effectively reduced systemic inflammatory cytokines and the resulting radiation-induced leptomeningeal metastasis.