Molecular Oncology最新文献

Clinical outcomes in ROS1-fusion positive (ROS1+) non-small cell lung cancer (NSCLC) by fusion partner and resistance mechanisms are limited. This cohort study included 56 ROS1+ patients (FISH or NGS confirmed); fusion partners were identified in 27 cases, including CD74 (n = 10), EZR (n = 7), and SDC4 (n = 7). Clinical data were available for 50 patients (median age 62; 51% female; 32% never-smokers). Forty patients received tyrosine kinase inhibitors (TKIs), mostly crizotinib (n = 38). Crizotinib showed a 55% objective response rate (ORR) and a median progression-free survival (mPFS) of 5.3 months. Brain metastases (HR 2.65, 95% CI 1.06-6.60, P = 0.037) and prior chemotherapy (HR 3.17, 95% CI 1.35-7.45, P = 0.008) had a higher risk of progression. Sixteen patients received subsequent lorlatinib, with an ORR of 28% and mPFS of 3.7 months. G2032R and L2026M resistance mutations were identified in four lorlatinib non-responders, and in vitro studies confirmed resistance to lorlatinib. Fusion partners did not affect crizotinib outcomes. Lorlatinib was ineffective against on-target resistance. Real-world data showed lower TKI efficacy than clinical trials, highlighting the role of clinical and molecular factors in treatment response.

Undifferentiated pleomorphic sarcoma (UPS) is a rare cancer with limited systemic treatment options and poor outcomes. To seek novel therapeutic interventions, we undertook mutational analysis of 20 UPS patient tumours, four established UPS cell lines and three patient-derived xenograft (PDX) models. Frequently mutated genes were uncommon; in contrast, copy number (CN) events were common with CN gain frequently observed at genes including JUN, EGFR and CDK6 and loss at WNT8B, RB1 and PTEN. Analysis of overlapping genomic changes between patient tumours and PDX models or cell lines revealed druggable events. A selected panel of drugs targeting these was analysed in in vitro UPS models demonstrating that the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib is synergistic in combination with the fibroblast growth factor receptor (FGFR) inhibitor infigratinib. This was further confirmed to be efficacious in an ex vivo tumour slice model. Taken together, our results demonstrate the rationale for utilising genomic data to identify drug classes targeting druggable events in low-prevalence cancers and indicate that trametinib alone or in combination with infigratinib should be further explored for clinical UPS management.

Melanoma, the deadliest form of skin cancer, poses a significant challenge due to its genetic heterogeneity and high metastatic potential. While cytotoxic T cell (CTL)-based immunotherapies have made remarkable progress in recent years, the therapeutic potential of natural killer-(NK) cells is increasingly recognized. However, resistance mechanisms to both CTL- and NK-cell-mediated immunotherapies hinder effective treatment. To evaluate the exclusive role of NK-cells in anti-melanoma immunity, we performed 2D and 3D co-culture-based cytotoxicity assays under varying conditions. Our findings revealed a protective phenotype in melanoma cells following prolonged exposure to primary NK-cells. By combining experimental data with bioinformatic analyses, we identified key genes and pathways involved in melanoma cell adaptation to NK-cell-mediated killing (NKmK). We found that cytokines such as IFNγ play a major role in suppressing NKmK with MHC II surface expression being a critical factor. Targeting the master regulator CIITA, which governs MHC II expression and is affected by IFNγ, significantly reduced melanoma cell resistance to NKmK. This study provides potential strategies to overcome resistance to NK-cell-based immunotherapies and offers novel insights into melanoma immune escape mechanisms.

While radioactive iodine therapy (RAIT) has been an effective treatment for thyroid cancer, its link to clonal hematopoiesis (CH) has been yet underexplored. In this study, error-corrected sequencing (median depth: 1926×) of 93 CH-related genes was performed from the blood samples of 358 thyroid cancer patients, including 110 controls (no RAIT) and 248 RAIT recipients. RAIT recipients were stratified into low- and high-dose groups using a 7.4 GBq cutoff. Multivariable logistic regression revealed that the high-dose group had a higher CH prevalence with variant allele frequency (VAF) higher than 2% compared to controls, especially in patients aged ≥50 (OR = 2.44, CI = 1.04-6.00, P = 0.04). Thirteen genes had mutations with VAF >2%, with DNMT3A, TET2, and PPM1D being the most common. Notably, only the PPM1D mutations were significantly linked to RAIT, occurring more frequently in the high-dose group (13%) compared to the low-dose group (5%) or controls (2%) at a VAF cutoff of 0.5%. In silico analyses indicated that truncating PPM1D mutations confer a selective advantage under high-dose RAIT and with older age. Although the prognostic implications of PPM1D-mutated CH remain to be further elucidated, these findings offer valuable insights for optimizing RAIT dosing in thyroid cancer patients.

Triple-negative breast cancer (TNBC) remains the breast cancer subtype with the poorest prognosis. While PARP inhibitors (PARPi) effectively target BRCA1/2-mutant TNBCs via synthetic lethality, most TNBCs are BRCA1/2 wild-type. Synergistic drug combinations may expand PARPi efficacy to BRCA-proficient TNBC. To identify new PARPi combinations, we screened a library of 166 FDA-approved oncology drugs for synergy with Olaparib in TNBC cells. We found that Exemestane, an aromatase inhibitor, synergized with Olaparib, significantly decreasing IC₅₀ values and clonogenicity while increasing DNA damage and apoptosis. The mechanistic basis for this synergy was rationalized by the previously unreported ability of Exemestane to induce replication stress via reactive oxygen species (ROS) generation and oxidative stress. This combination had low cytotoxicity toward normal breast epithelial cells, and Exemestane has no reported severe toxicity as a monotherapy. The combination of Olaparib and Exemestane was able to achieve enhanced tumor growth inhibition in a murine xenograft model, greater than either drug employed as a single agent, and GO and KEGG enrichment analysis indicated alterations in pathways associated with cell death in response to Exemestane and Olaparib treatment.

Ovarian cancer (OC) has the highest mortality rate of all gynaecological malignancies, partly attributable to its propensity for chemotherapy resistance. The most common subtype of OC is serous, of which high-grade serous ovarian cancer (HGSOC) is the most lethal subtype. Protein tyrosine phosphatase 4A3 (PTP4A3) overexpression is implicated in tumour cell invasion and metastasis by upregulating the PI3K/Akt/mTORC1 axis. Previously, we reported that PTP4A3 increased the survival of non-serous OC cells by activating the autophagy pathway. Here, we investigated the impact of PTP4A3 on cell proliferation, autophagy and chemoresistance in HGSOC cells and whether targeting PTP4A3 in HGSOC cells that overexpress this phosphatase would sensitise them to existing chemotherapeutic drugs. Gene silencing of PTP4A3 resulted in the upregulation of compensatory mechanisms that overcame the loss of PTP4A3 expression, but this was mitigated by pan-PTP4A inhibition with JMS-053 in HGSOC cells. Moreover, shRNA-mediated silencing of PTP4A3 sensitised HGSOC cells to clinically relevant chemotherapeutic drugs. Overall, we show that compensatory mechanisms from PTP4A1 and PTP4A2 can arise when specifically targeting PTP4A3 in HGSOC and that pan-PTP4A inhibition can overcome those effects.

Reactive oxygen species (ROS) are a diverse group of molecules that serve as both essential signalling mediators and potential drivers of oxidative stress. In tumours, ROS influence critical processes such as proliferation, angiogenesis, metabolic adaptation and therapy resistance. These processes are further modulated by reduced oxygen availability (hypoxia), a defining feature of many solid tumours that can alter redox balance and cellular signalling. The interplay between ROS and hypoxia is highly dynamic, with both factors shaping tumour behaviour in complex and often unpredictable ways. Accurately measuring ROS and tumour oxygenation remains a significant challenge due to their transient nature and variability in levels across different tumour types. In this guide, we provide a comprehensive update on the dynamic interaction between ROS and hypoxia in tumours, evaluate current strategies for ROS detection and discuss emerging therapeutic approaches that target redox vulnerabilities in cancer. Understanding the intricate relationship between ROS and hypoxia is crucial for refining therapeutic strategies and improving patient outcomes.

Mitochondria are essential organelles that regulate various biological processes including metabolism. Beyond their intracellular functions, intercellular mitochondrial transfer has emerged as a novel mechanism of intercellular communication. Notably, an increasing number of studies have reported its occurrence in the tumor microenvironment (TME), where it contributes to tumor progression. While previous studies largely characterized cancer cells as recipients of mitochondria, Cangkrama et al. demonstrated that cancer cells donate their mitochondria to fibroblasts via tunneling nanotubes. The mitochondrial transfer to fibroblasts reprogrammed them into cancer-associated fibroblasts exhibiting combined myofibroblastic and inflammatory characteristics, with enhanced oxidative metabolism and pro-tumorigenic activity. Our group has identified mitochondrial 'hijack' from cancer cells to tumor-infiltrating lymphocytes, leading to an impaired antitumor immunity. These insights underscore the need to recognize cancer cells as mitochondrial donors in the TME capable of reshaping the TME to their own advantage, resembling a dynastic expansion strategy that exerts influence by strategically placing lineages.

Immune checkpoint inhibitors are important for treatment across tumor types but are not universally effective in controlling disease. Early understanding of tumor response, or lack thereof, can inform treatment decisions. This study evaluates changes in circulating tumor DNA (ctDNA) and blood tumor mutational burden (bTMB) for associations with response to programmed cell death 1 ligand 1 (PD-L1) blockade. We sequenced cell-free DNA collected at the start of therapy, on treatment, and at the end of therapy for 153 patients treated with atezolizumab as part of the pan-tumor MyPathway study (NCT02091141). ctDNA tumor fraction (TF) and bTMB were assessed for correlation with progression-free survival (PFS) and overall survival (OS). We found that molecular response (MR, ≥50% decrease in TF at cycle 3 day 1) was associated with improved PFS (9.7 vs 1.5 months from C3D1; HR = 0.27) and OS (21.1 vs 14.3 months from C3D1; HR = 0.44). These findings were consistent when limited to patients with stable disease (SD; PFS HR = 0.55; OS HR = 0.39). bTMB was correlated with tissue-based TMB (tTMB) when TF was high (≥1%), but not with OS in this cohort. In total, 61% of baseline samples had predicted clonal hematopoiesis (CH) variants. No correlation between maximum variant allele frequency (maxVAF) of predicted CH and TF was seen. In summary, MR is associated with outcomes for patients treated with atezolizumab and could stratify patients with SD. While CH was common, maxVAF for CH variants was not associated with ctDNA TF. Quantification of ctDNA enables therapy response monitoring and is critical for interpretation of bTMB as a proxy for tTMB.

The luminal subtype (estrogen receptor-positive, ER+) is the most common and the most heterogeneous type of breast carcinoma (BC) in women. During our study, we determined expression levels of all microRNAs (miRNome) in 101 ER+ BC samples and identified 25 miRNAs being associated with proliferative markers. Using comprehensive in silico analyses we prioritized CHEK1, CDC25A, and CCNE1 as candidate genes affecting the proliferation of ER+ BC, with two microRNAs from the miR-497∼195 cluster identified as their potential regulators. In a cohort of 217 patients, we found a significant association between high expression of CHEK1 and shorter relapse-free survival (RFS) in luminal BC patients treated with adjuvant chemotherapy, especially in patients with luminal A subtype. In patients treated with neoadjuvant therapy, the opposite role for RFS was observed for hsa-miR-195-5p. Subsequently, we confirmed the potency of hsa-miR-195-5p to inhibit the expression of CHEK1 in vitro. Moreover, the specific Chk1 inhibitor rabusertib (LY2603618) significantly enhanced the efficacy of doxorubicin in both ER+ and ER- cell lines. In summary, we have identified the association of a specific miRNA profile with highly proliferative luminal BCs and demonstrated the ability of hsa-miR-195-5p to inhibit CHEK1 expression in BC in vitro, underlining the importance of CHEK1 expression and its inhibition for prognosis and treatment of patients with luminal BCs.