Molecular Oncology最新文献

Malignant ascites is commonly produced in advanced epithelial ovarian cancer (EOC) and serves as unique microenvironment for tumour cells. Acellular ascites fluid (AAF) is rich in signalling molecules and has been proposed to play a role in the induction of chemoresistance. Through in vitro testing of drug sensitivity and by assessing intracellular phosphorylation status in response to mono- and combination treatment of five EOC cell lines after incubation with AAFs derived from 20 different patients, we investigated the chemoresistance-inducing potential of ascites. We show that the addition of AAFs to the culture media of EOC cell lines has the potential to induce resistance to standard-of-care drugs (SCDs). We also show that AAFs induce time- and concentration-dependent activation of downstream signalling to signal transducer and activator of transcription 3 (STAT3), and concomitantly altered phosphorylation of mitogen-activated protein kinase kinase (MEK), phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) and nuclear factor NF-kappa-B (NFκB). Antibodies targeting the interleukin-6 receptor (IL6R) effectively blocked phosphorylation of STAT3 and STAT1. Treatments with SCDs were effective in reducing cell viability in only a third of 30 clinically relevant conditions examined, defined as combinations of drugs, different cell lines and AAFs. Combinations of SCDs and novel therapeutics such as trametinib, fludarabine or rapamycin were superior in another third. Notably, we could nominate effective treatment combinations in almost all conditions except in 4 out of 30 conditions, in which trametinib or fludarabine showed higher efficacy alone. Taken together, our study underscores the importance of the molecular characterisation of individual patients' AAFs and the impact on treatment resistance as providing clinically meaningful information for future precision treatment approaches in EOC.

The HECT-type E3 ubiquitin WWP1 (also known as NEDD4-like E3 ubiquitin-protein ligase WWP1) acts as an oncogenic factor in acute myeloid leukemia (AML) cells. WWP1 overexpression in AML confers a proliferative advantage to leukemic blasts (abnormal immature white blood cells) and counteracts apoptotic cell death and differentiation. In an effort to elucidate the molecular basis of WWP1 oncogenic activities, we identified WWP1 as a previously unknown negative regulator of thioredoxin-interacting protein (TXNIP)-mediated reactive oxygen species (ROS) production in AML cells. TXNIP inhibits the disulfide reductase enzymatic activity of thioredoxin (Trx), impairing its antioxidant function and, ultimately, leading to the disruption of cellular redox homeostasis. In addition, TXNIP restricts cell growth and survival by blocking glucose uptake and metabolism. Here, we found that WWP1 directly interacts with TXNIP, thus promoting its ubiquitin-dependent proteasomal proteolysis. As a result, accumulation of TXNIP in response to WWP1 inactivation in AML blasts reduces Trx activity and increases ROS production, hence inducing cellular oxidative stress. Increased ROS generation in WWP1-depleted cells culminates in DNA strand breaks and subsequent apoptosis. Coherently with TXNIP stabilization following WWP1 inactivation, we also observed an impairment of both glucose up-take and consumption. Hence, a contribution to the increased cell death observed in WWP1-depleted cells also possibly arises from the attenuation of glucose up-take and glycolytic flux resulting from TXNIP accumulation. Future studies are needed to establish whether TXNIP-dependent deregulation of redox homeostasis in WWP1-overexpressing blasts may affect the response of leukemic cells to chemotherapeutic drugs.

Retraction: H. Zhang, T. Liu, S. Yi, L. Gu, and M. Zhou, "Targeting MYCN IRES in MYCN-amplified Neuroblastoma With Mir-375 Inhibits Tumor Growth and Sensitizes Tumor Cells to Radiation," Molecular Oncology 9, no. 7 (2015): 1301-1311, https://doi.org/10.1016/j.molonc.2015.03.005. The above article, published online on 24 March 2015 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Kevin Ryan; FEBS Press; and John Wiley & Sons Ltd. The retraction has been agreed upon following an investigation into concerns raised by a third party, which revealed inappropriate image section duplications within the article (Figure 5B) and between this (Figures 3B and 4B) and another article published by the same group of authors in a different scientific context. The authors were unable to provide a satisfactory explanation and the original raw data, which has led the editors to lose confidence in the data presented. Therefore, the editors consider the conclusions substantially compromised and are retracting the paper.

DNA methylation biomarkers have emerged as promising tools for cancer detection. Common methylation patterns across tumor types allow multi-cancer detection. Droplet digital PCR (ddPCR) has gained considerable attention for methylation detection. However, multi-cancer detection using multiple targets in ddPCR has never been performed before. Therefore, we developed a multiplex ddPCR assay for multi-cancer detection. Based on previous data analyses using The Cancer Genome Atlas (TCGA), we selected differentially methylated targets for eight frequent tumor types (lung, breast, colorectal, prostate, pancreatic, head and neck, liver, and esophageal cancer). Three targets were validated using ddPCR in 103 tumor and 109 normal adjacent fresh frozen samples. Two distinct ddPCR assays were successfully developed. Output data from both assays is combined to obtain a read-out from the three targets together. Our overall ddPCR assay has a cross-validated area under the curve (cvAUC) of 0.948. Performance between distinct cancer types varies, with sensitivities ranging from 53.8% to 100% and specificities ranging from 80% to 100%. Compared to previously published single-target parameters, we show that combining targets can drastically increase sensitivity and specificity, while lowering DNA input. In conclusion, we are the first to report a multi-cancer methylation ddPCR assay, which allows for highly accurate tumor predictions.

Precise regulation of gene expression is essential for proper development and the maintenance of homeostasis in organisms. Studies have shown that some transcriptional regulatory proteins influence gene expression through the formation of dynamic, locally concentrated assemblies known as condensates, while dysregulation of transcriptional condensates was associated with several cancers, such as Ewing sarcoma and AML [Wang Y et al. (2023) Nat Chem Biol 19, 1223-1234; Chandra B et al. (2022) Cancer Discov 12, 1152-1169]. Mutations in the histone acetylation "reader" eleven-nineteen-leukemia (ENL) have been shown to form discrete condensates at endogenous genomic targets, but it remains unclear how ENL mutations drive tumorigenesis and whether it is correlated with their condensate formation property. Liu et al. now show, using a conditional knock-in mouse model, that ENL YEATS domain mutation is a bona fide oncogenic driver for AML. This mutant ENL forms condensates in hematopoietic stem/progenitor cells at the genomic loci of key leukemogenic genes, including Meis1 and Hoxa cluster genes, and disrupting condensate formation via mutagenesis impairs its chromatin and oncogenic function. Furthermore, they show that small-molecule inhibition of the acetyl-binding activity displaces ENL mutant condensates from oncogenic target loci, and this inhibitor significantly impairs the onset and progression of AML driven by mutant ENL in vivo.

Retraction: Y.-J. Li, Z. Yang, Y.-Y. Wang, and Y. Wang, "Long Noncoding RNA ZNF667-AS1 Reduces Tumor Invasion and Metastasis in Cervical Cancer by Counteracting Microrna-93-3p-Dependent PEG3 Downregulation," Molecular Oncology 13, no. 11 (2019): 2375-2392, https://doi.org/10.1002/1878-0261.12565. The above article, published online on 17 October 2019 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Kevin Ryan; FEBS Press; and John Wiley & Sons Ltd. The retraction has been agreed upon following an investigation into concerns raised by a third party, which revealed implausible Western blot data (Figures 5B, L, G and Q), and an image duplication in Figure 6B. The authors' failure to respond with the original raw data has led the editors to lose confidence in the data presented. Therefore, the editors consider the conclusions substantially compromised and are retracting the paper.

Renowned as the predominant form of kidney cancer, clear cell renal cell carcinoma (ccRCC) exhibits susceptibility to immunotherapies due to its specific expression profile as well as notable immune cell infiltration. Despite this, effectively treating metastatic ccRCC remains a significant challenge, necessitating a more profound comprehension of the underlying molecular mechanisms governing its progression. Here, we unveil that the enhanced expression of the RNA-binding protein DNA dC → dU-editing enzyme APOBEC-3C (APOBEC3C; also known as A3C) in ccRCC tissue and ccRCC-derived cell lines serves as a catalyst for tumor growth by amplifying nuclear factor-kappa B (NF-κB) activity. By employing RNA-sequencing and cell-based assays in ccRCC-derived cell lines, we determined that A3C is a stress-responsive factor and crucial for cell survival. Furthermore, we identified that A3C binds and potentially stabilizes messenger RNAs (mRNAs) encoding positive regulators of the NF-κB pathway. Upon A3C depletion, essential subunits of the NF-κB family are abnormally restrained in the cytoplasm, leading to deregulation of NF-κB target genes. Our study illuminates the pivotal role of A3C in promoting ccRCC tumor development, positioning it as a prospective target for future therapeutic strategies.

The ability of cancer cells to change and adapt poses a critical challenge to identifying curative solutions. Tumor evolution has been extensively studied from a genetic perspective, to guide clinicians in selecting the most appropriate therapeutic option based on a patient's mutational profile. However, several studies reported that tumors can evolve toward more aggressive stages or become resistant to therapies without changing their genetic makeup. Indeed, several cell-intrinsic and cell-extrinsic mechanisms contribute to tumor evolution. In this viewpoint, I focus on how chromatin, epigenetic, and transcriptional changes contribute to tumor evolution, allowing cancer cells to transition to different cell states and bypass response to therapies. Although tumor nongenetic evolution is harder to trace and predict, understanding its principles might open new therapeutic opportunities.

Metastatic castration-resistant prostate cancer (mCRPC) is characterized by loss of androgen receptor (AR) sensitivity and oncogenic activation of the PI3K/AKT/mTOR (PAM) pathway. Loss of the PI3K regulator PTEN is frequent during prostate cancer (PC) initiation, progression, and therapeutic resistance. Co-targeting the PAM/AR pathways is a promising mCRPC treatment strategy but is hampered by reciprocal negative feedback inhibition or feedback relief. Most PAM inhibitors selectively spare (or weakly inhibit) one or more key nodes of the PAM pathway, potentiating drug resistance depending on the PAM pathway mutation status of patients. We posited that gedatolisib, a uniformly potent inhibitor of all class I PI3K isoforms, as well as mTORC1 and mTORC2, would be more effective than inhibitors targeting single PAM pathway nodes in PC cells. Using a combination of functional and metabolic assays, we evaluated a panel of PC cell lines with different PTEN/PIK3CA status for their sensitivity to multi-node PAM inhibitors (PI3K/mTOR: gedatolisib, samotolisib) and single-node PAM inhibitors (PI3Kα: alpelisib; AKT: capivasertib; mTOR: everolimus). Gedatolisib induced anti-proliferative and cytotoxic effects with greater potency and efficacy relative to the other PAM inhibitors, independent of PTEN/PIK3CA status. The superior effects of gedatolisib were likely associated with more effective inhibition of critical PAM-controlled cell functions, including cell cycle, survival, protein synthesis, oxygen consumption rate, and glycolysis. Our results indicate that potent and simultaneous blockade of all class I PI3K isoforms, mTORC1, and mTORC2 could circumvent PTEN-dependent resistance. Gedatolisib, as a single agent and in combination with other therapies, reported promising preliminary efficacy and safety in various solid tumor types. Gedatolisib is currently being evaluated in a Phase 1/2 clinical trial in combination with darolutamide in patients with mCRPC previously treated with an AR inhibitor, and in a Phase 3 clinical trial in combination with palbociclib and fulvestrant in patients with HR+/HER2- advanced breast cancer.

Oestrogen receptor alpha (ER; gene symbol ESR1) is the most important prognostic and treatment-predictive biomarker in breast cancer. Drugs targeting oestrogen and ER for endocrine therapy of breast cancer include aromatase inhibitors, the selective ER modulator tamoxifen and the selective ER degrader fulvestrant. Tumours can develop resistance to endocrine therapy through several mechanisms, which is often linked to altered expression of ER. To investigate the role of promoter methylation in the regulation of ESR1 expression, we used bisulfite sequencing to measure methylation at CpG sites in alternative ER promoter regions for six cell line models of fulvestrant resistance. Both CpG methylation and expression of alternative first exons changed dynamically, with striking differences between cell lines that had stable or unstable resistance upon fulvestrant withdrawal. Methylation at some CpG sites was strongly negatively correlated with expression of specific first exons. In a breast tumour cohort, higher relative expression of upstream alternative first exons was associated with worse prognosis in post-menopausal women with ER-positive tumours who received endocrine therapy.