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Proceedings of the National Academy of... Jul 2023Type II topoisomerases transiently cleave duplex DNA as part of a strand passage mechanism that helps control chromosomal organization and superstructure. Aberrant DNA...
Type II topoisomerases transiently cleave duplex DNA as part of a strand passage mechanism that helps control chromosomal organization and superstructure. Aberrant DNA cleavage can result in genomic instability, and how topoisomerase activity is controlled to prevent unwanted breaks is poorly understood. Using a genetic screen, we identified mutations in the beta isoform of human topoisomerase II (hTOP2β) that render the enzyme hypersensitive to the chemotherapeutic agent etoposide. Several of these variants were unexpectedly found to display hypercleavage behavior in vitro and to be capable of inducing cell lethality in a DNA repair-deficient background; surprisingly, a subset of these mutations were also observed in sequences from cancer genome databases. Using molecular dynamics simulations and computational network analyses, we found that many of the mutations obtained from the screen map to interfacial points between structurally coupled elements, and that dynamical modeling could be used to identify other damage-inducing alleles present in cancer genome databases. This work establishes that there is an innate link between DNA cleavage predisposition and sensitivity to topoisomerase II poisons, and that certain sequence variants of human type II topoisomerases found in cancer cells can act as DNA-damaging agents. Our findings underscore the potential for hTOP2β to function as a clastogen capable of generating DNA damage that may promote or support cellular transformation.
Topics: Humans; Mutagens; Topoisomerase II Inhibitors; Etoposide; DNA Topoisomerases, Type II; DNA Damage; DNA; Neoplasms
PubMed: 37406101
DOI: 10.1073/pnas.2302064120 -
Haematologica Feb 2024Primary hemophagocytic lymphohistiocytosis (pHLH) is a rare immune disorder and hematopoietic stem cell transplan- tation (HSCT) is the only potentially curative...
Primary hemophagocytic lymphohistiocytosis (pHLH) is a rare immune disorder and hematopoietic stem cell transplan- tation (HSCT) is the only potentially curative treatment. Given the high pre-HSCT mortality of pHLH patients reported in the HLH-2004 study (17%), more regimens to effectively control the disease and form a bridge with HSCT are needed. We conducted a retrospective study of pHLH children treated by ruxolitinib (RUX)-based regimen. Generally, patients received RUX until HSCT or unacceptable toxic side-effect. Methylprednisolone and etoposide were added sequentially when the disease was suboptimally controlled. The primary end point was 1-year overall survival. Twenty-one pHLH patients (12 previously treated and 9 previously untreated) were included with a median follow-up of 1.4 years. At last follow-up, 17 (81.0%) patients were alive with a 1-year overall survival of 90.5% (95% confidence interval: 84.1-96.9). Within the first 8 weeks, all patients had an objective response, of which 19 (90.5%) achieved complete response (CR) and two (9.5%) achieved partial response (PR) as a best response. Seventeen (81.0%) patients received HSCT, of which 13 (76.5%) had CR, three (17.6%) had PR and one (5.9%) had disease reactivation at the time of HSCT. Fifteen (88.2) patients were alive post- HSCT. Notably, eight (38.1%) patients received zero doses of etoposide, suggesting the potential of RUX-based regimen to reduce chemotherapy intensity. Patients tolerated RUX-based regimen well and the most frequently observed adverse events were hematologic adverse events. Overall, RUX-based regimen was effective and safe and could be used as a bridge to HSCT for pHLH children.
Topics: Child; Humans; Lymphohistiocytosis, Hemophagocytic; Treatment Outcome; Retrospective Studies; Etoposide; Hematopoietic Stem Cell Transplantation; Pathologic Complete Response; Nitriles; Pyrazoles; Pyrimidines
PubMed: 37470145
DOI: 10.3324/haematol.2023.283478 -
Journal of Biomolecular Structure &... 2023Natural products have emerged as major leads for the discovery and development of new anti-cancer drugs. The plant-derived anti-cancer drugs account for approximately... (Review)
Review
Natural products have emerged as major leads for the discovery and development of new anti-cancer drugs. The plant-derived anti-cancer drugs account for approximately 60% and the quest for new anti-cancer agents is in progress. Anti-cancer leads have been isolated from plants, animals, marine organisms, and microorganisms from time immemorial. The process of semisynthetic modifications of the parent lead has led to the generation of new anti-cancer agents with improved therapeutic efficacy and minimal side effects. The various chemo-informatics tools, bioinformatics, high-throughput screening, and combinatorial synthesis are able to deliver the new natural product lead molecules. Plant-derived anticancer agents in either late preclinical development or early clinical trials include taxol, vincristine, vinblastine, topotecan, irinotecan, etoposide, paclitaxel, and docetaxel. Similarly, anti-cancer agents from microbial sources include dactinomycin, bleomycin, mitomycin C, and doxorubicin. In this review, we highlighted the importance of natural products leads in the discovery and development of novel anti-cancer agents. The semisynthetic modifications of the parent lead to the new anti-cancer agent are also presented. Further, the leads in the preclinical settings with the potential to become effective anticancer agents are also reviewed.Communicated by Ramaswamy H. Sarma.
PubMed: 36255181
DOI: 10.1080/07391102.2022.2134212 -
International Journal of Gynecological... Sep 2023To evaluate clinicopathologic features and oncologic outcomes of patients with neuroendocrine cervical carcinoma in an institutional neuroendocrine cervical tumor...
OBJECTIVE
To evaluate clinicopathologic features and oncologic outcomes of patients with neuroendocrine cervical carcinoma in an institutional neuroendocrine cervical tumor registry.
METHODS
Retrospective study including patients with neuroendocrine cervical carcinomas diagnosed between 1986 and 2022. Patients were categorized into International Federation of Gynecology and Obstetrics 2018 stage groups: early-stage (IA1-IB2, IIA1); locally advanced (IB3, IIA2-IVA); and advanced (IVB). Clinicopathologic characteristics and oncologic outcomes were evaluated by stage. Survival was compared between patients diagnosed in 1986-2003 and those diagnosed in 2004-2016. Progression-free and overall survival were estimated using the Kaplan-Meier product-limit estimator.
RESULTS
A total of 453 patients was included, 133 (29%) with early-stage, 226 (50%) with locally advanced, and 94 (21%) with advanced disease. Median age was 38 years (range 21-93). Sixty-nine percent (306/453) had pure and 32% (146/453) had mixed histology. The node positivity rate (surgical or radiological detection) was 19% (21/108) for tumors ≤2 cm, 37% (39/105) for tumors >2 to ≤4 cm, and 61% (138/226) for tumors >4 cm (p<0.0001). After primary treatment, rates of complete response were 86% (115/133) for early-stage, 65% (147/226) for locally advanced, and 19% (18/94) for advanced disease (p<0.0001). The recurrence/progression rate was 43% for early-stage, 69% for locally advanced, and 80% for advanced disease (p<0.0001). Five-year progression-free and overall survival rates were 59% (95% CI 50% to 68%) and 71% (95% CI 62% to 80%), respectively, for early-stage, 28% (95% CI 22% to 35%) and 36% (95% CI 29% to 43%), respectively, for locally advanced, and 6% (95% CI 0% to 11%) and 12% (95% CI 5% to 19%), respectively, for advanced disease. For early-stage disease, the 5-year progression-free survival rate was 68% for tumors ≤2 cm and 43% for tumors >2 to ≤4 cm (p=0.0013). Receiving cisplatin/carboplatin plus etoposide (HR=0.33, 95% CI 0.17 to 0.63, p=0.0008) and receiving curative radiotherapy (HR=0.32, 95% CI 0.17 to 0.6, p=0.0004) were positive predictors of survival for patients with advanced disease.
CONCLUSION
Among patients with neuroendocrine cervical carcinomas, overall survival is favorable for patients with early-stage disease. However, most patients present with locally advanced disease, and overall survival remains poor in this subgroup. For patients with advanced disease, receiving cisplatin/carboplatin plus etoposide and curative radiation therapy is associated with improved overall survival.
Topics: Female; Humans; Young Adult; Adult; Middle Aged; Aged; Aged, 80 and over; Uterine Cervical Neoplasms; Prognosis; Retrospective Studies; Cisplatin; Carboplatin; Etoposide; Carcinoma, Neuroendocrine; Neuroendocrine Tumors; Registries; Neoplasm Staging
PubMed: 37567596
DOI: 10.1136/ijgc-2023-004708 -
Nature Communications Dec 2023The function of the mitogen-activated protein kinase signaling pathway is required for the activation of immediate early genes (IEGs), including EGR1 and FOS, for cell...
The function of the mitogen-activated protein kinase signaling pathway is required for the activation of immediate early genes (IEGs), including EGR1 and FOS, for cell growth and proliferation. Recent studies have identified topoisomerase II (TOP2) as one of the important regulators of the transcriptional activation of IEGs. However, the mechanism underlying transcriptional regulation involving TOP2 in IEG activation has remained unknown. Here, we demonstrate that ERK2, but not ERK1, is important for IEG transcriptional activation and report a critical ELK1 binding sequence for ERK2 function at the EGR1 gene. Our data indicate that both ERK1 and ERK2 extensively phosphorylate the C-terminal domain of TOP2B at mutual and distinctive residues. Although both ERK1 and ERK2 enhance the catalytic rate of TOP2B required to relax positive DNA supercoiling, ERK2 delays TOP2B catalysis of negative DNA supercoiling. In addition, ERK1 may relax DNA supercoiling by itself. ERK2 catalytic inhibition or knock-down interferes with transcription and deregulates TOP2B in IEGs. Furthermore, we present the first cryo-EM structure of the human cell-purified TOP2B and etoposide together with the EGR1 transcriptional start site (-30 to +20) that has the strongest affinity to TOP2B within -423 to +332. The structure shows TOP2B-mediated breakage and dramatic bending of the DNA. Transcription is activated by etoposide, while it is inhibited by ICRF193 at EGR1 and FOS, suggesting that TOP2B-mediated DNA break to favor transcriptional activation. Taken together, this study suggests that activated ERK2 phosphorylates TOP2B to regulate TOP2-DNA interactions and favor transcriptional activation in IEGs. We propose that TOP2B association, catalysis, and dissociation on its substrate DNA are important processes for regulating transcription and that ERK2-mediated TOP2B phosphorylation may be key for the catalysis and dissociation steps.
Topics: Humans; DNA; DNA Topoisomerases, Type II; Etoposide; Genes, Immediate-Early; Mitogen-Activated Protein Kinase 1; Phosphorylation; Transcriptional Activation
PubMed: 38097570
DOI: 10.1038/s41467-023-44089-y -
Cellular Signalling Feb 2024The signal transducer and activator of transcription 1 (STAT1) plays a crucial role in regulating tumor progression. However, the mechanisms governing its...
The signal transducer and activator of transcription 1 (STAT1) plays a crucial role in regulating tumor progression. However, the mechanisms governing its phosphorylation and biological functions remain incompletely understood. Here, we present compelling evidence indicating that knockdown of SIRT7 inhibits Smurf1-induced ubiquitination of STAT1, consequently impeding the proteasome pathway degradation of STAT1. This inhibition leads to increased stability of STAT1 and enhanced binding to JAK1. Importantly, SIRT7 exerts a negative regulatory effect on STAT1 activation and IFN-γ/STAT1 signaling in hepatocellular carcinoma (HCC). Etoposide treatment not only facilitates STAT1 activation but also downregulates SIRT7 expression. Notably, knockdown of STAT1 in SIRT7-deficient cells attenuates the increase in cell apoptosis induced by Etoposide treatment. In conclusion, our data shed light on the intricate interplay between ubiquitination, STAT1, SIRT7, and Smurf1, elucidating their impact on STAT1-related signaling. These insights contribute to a more comprehensive understanding of the molecular mechanisms involved in STAT1 regulation and suggest potential avenues for the development of targeted therapies against cancer.
Topics: Humans; Carcinoma, Hepatocellular; Liver Neoplasms; Etoposide; Cell Line, Tumor; Signal Transduction; Phosphorylation; STAT1 Transcription Factor; Sirtuins
PubMed: 38070755
DOI: 10.1016/j.cellsig.2023.111005 -
Cell Death & Disease Jan 2024DNA topoisomerase II (TOP2) is an enzyme that performs a critical function in manipulating DNA topology during replication, transcription, and chromosomal compaction by...
DNA topoisomerase II (TOP2) is an enzyme that performs a critical function in manipulating DNA topology during replication, transcription, and chromosomal compaction by forming a vital intermediate known as the TOP2-DNA cleavage complex (TOP2cc). Although the TOP2cc is often transient, stabilization can be achieved by TOP2 poisons, a family of anti-cancer chemotherapeutic agents targeting TOP2, such as etoposide (VP-16), and then induce double-strand breaks (DSBs) in cellular DNA. TOP2cc first needs to be proteolyzed before it can be processed by TDP2 for the removal of these protein adducts and to produce clean DNA ends necessary for proper repair. However, the mechanism by which TOP2βcc is proteolyzed has not been thoroughly studied. In this study, we report that after exposure to VP-16, MDM2, a RING-type E3 ubiquitin ligase, attaches to TOP2β and initiates polyubiquitination and proteasomal degradation. Mechanistically, during exposure to VP-16, TOP2β binds to DNA to form TOP2βcc, which promotes MDM2 binding and subsequent TOP2β ubiquitination and degradation, and results in a decrease in TOP2βcc levels. Biologically, MDM2 inactivation abrogates TOP2β degradation, stabilizes TOP2βcc, and subsequently increases the number of TOP2β-concealed DSBs, resulting in the rapid death of cancer cells via the apoptotic process. Furthermore, we demonstrate the combination activity of VP-16 and RG7112, an MDM2 inhibitor, in the xenograft tumor model and in situ lung cancer mouse model. Taken together, the results of our research reveal an underlying mechanism by which MDM2 promotes cancer cell survival in the presence of TOP2 poisons by activating proteolysis of TOP2βcc in a p53-independent manner, and provides a rationale for the combination of MDM2 inhibitors with TOP2 poisons for cancer therapy.
Topics: Animals; Humans; Mice; Disease Models, Animal; DNA; DNA Topoisomerases, Type II; DNA-Binding Proteins; Etoposide; Phosphoric Diester Hydrolases; Proteolysis; Proto-Oncogene Proteins c-mdm2; Tumor Suppressor Protein p53
PubMed: 38263255
DOI: 10.1038/s41419-024-06474-3 -
Nintedanib plus Chemotherapy for Small Cell Lung Cancer with Comorbid Idiopathic Pulmonary Fibrosis.Annals of the American Thoracic Society Apr 2024A fatal acute exacerbation (AE) occasionally develops during chemotherapy for small cell lung cancer (SCLC) with comorbid idiopathic pulmonary fibrosis (IPF). This...
A fatal acute exacerbation (AE) occasionally develops during chemotherapy for small cell lung cancer (SCLC) with comorbid idiopathic pulmonary fibrosis (IPF). This study aimed to assess the safety and efficacy of carboplatin, etoposide, and nintedanib combination therapy for unresectable SCLC with comorbid IPF. The NEXT-SHIP study is a multicenter, single-arm, phase 2 trial for unresectable SCLC with IPF (Japan Registry of Clinical Trials registry number jRCTs031190119). The patients received carboplatin, etoposide, and nintedanib (150 mg twice daily). The primary endpoint was the incidence of IPF-AE at 28 days after the last administration of cytotoxic chemotherapy, and the sample size was set at 33 (5.0% expected, 20.0% threshold). A total of 33 patients were registered; 87.9% were male, the median age was 73 years, the median percentage forced vital capacity was 85.2%, and 51.5% had honeycomb lungs. The median observation period was 10.5 months. The incidence of IPF-AE at 28 days after the last administration of cytotoxic chemotherapy was 3.0% (90% confidence interval [CI], 0.2-13.6). The objective response rate was 68.8% (95% CI, 50.0-83.9). The median progression-free survival and overall survival times were 4.2 months (95% CI, 4.2-5.5) and 13.4 months (95% CI, 8.1-21.6), respectively. The most common adverse event of grade 3 or higher was neutropenia (81.8%), followed by leukopenia (39.4%) and thrombocytopenia (30.3%). This study met its primary endpoint regarding the incidence of IPF-AEs with promising results for efficacy. Carboplatin, etoposide, and nintedanib combination therapy may be one of the standard treatment options for SCLC with comorbid IPF.Clinical trial registered with the Japan Registry of Clinical Trials (jRCTs031190119).
Topics: Aged; Female; Humans; Male; Anemia; Antineoplastic Combined Chemotherapy Protocols; Carboplatin; Disease Progression; Etoposide; Idiopathic Pulmonary Fibrosis; Indoles; Lung Neoplasms; Small Cell Lung Carcinoma; Treatment Outcome
PubMed: 38364204
DOI: 10.1513/AnnalsATS.202311-941OC -
Aging Sep 2023Senescent cells (SnCs) have been described to accumulate in osteoarthritis (OA) joint tissues in response to injury, thereby participating in OA development and...
Senescent cells (SnCs) have been described to accumulate in osteoarthritis (OA) joint tissues in response to injury, thereby participating in OA development and progression. However, clinical therapeutic approaches targeting SnCs using senolysis, although promising in preclinical OA models, have not yet proven their efficacy in patients with knee OA. This pitfall may be due to the lack of understanding of the mechanisms underlying chondrocyte senescence. Therefore, our study aimed to generate models of chondrocyte senescence. This study used etoposide, to induce DNA damage-related senescence or chronic exposure to IL-1β to entail inflammation-related senescence in human OA chondrocytes. Several hallmarks of cellular senescence, such as cell cycle arrest, expression of cyclin-dependent kinase inhibitors, DNA damages, and senescence-associated secretory profile were evaluated. Chronic exposure to IL-1β induces only partial expression of senescence markers and does not allow us to conclude on its ability to induce senescence in chondrocytes. On the other hand, etoposide treatment reliably induces DNA damage-related senescence in human articular chondrocytes evidenced by loss of proliferative capacity, DNA damage accumulation, and expression of some SASP components. Etoposide-induced senescence model may help investigate the initiation of cellular senescence in chondrocytes, and provide a useful model to develop therapeutic approaches to target senescence in OA.
Topics: Humans; Chondrocytes; Etoposide; Osteoarthritis, Knee; Biological Transport; DNA Damage
PubMed: 37659108
DOI: 10.18632/aging.204881 -
Journal of Clinical Oncology : Official... Sep 2023Chemotherapeutic exposures are associated with subsequent malignant neoplasm (SMN) risk. The role of genetic susceptibility in chemotherapy-related SMNs should be...
PURPOSE
Chemotherapeutic exposures are associated with subsequent malignant neoplasm (SMN) risk. The role of genetic susceptibility in chemotherapy-related SMNs should be defined as use of radiation therapy (RT) decreases.
PATIENTS AND METHODS
SMNs among long-term childhood cancer survivors of European (EUR; N = 9,895) and African (AFR; N = 718) genetic ancestry from the Childhood Cancer Survivor Study and St Jude Lifetime Cohort Study were evaluated. An externally validated 179-variant polygenic risk score (PRS) associated with pleiotropic adult cancer risk from the UK Biobank Study (N > 400,000) was computed for each survivor. SMN cumulative incidence comparing top and bottom PRS quintiles was estimated, along with hazard ratios (HRs) from proportional hazards models.
RESULTS
A total of 1,594 survivors developed SMNs, with basal cell carcinomas (n = 822), breast cancers (n = 235), and thyroid cancers (n = 221) being the most frequent. Although SMN risk associations with the PRS were extremely modest in RT-exposed EUR survivors (HR, 1.22; = .048; n = 4,630), the increase in 30-year SMN cumulative incidence and HRs comparing top and bottom PRS quintiles was statistically significant among nonirradiated EUR survivors (n = 4,322) treated with alkylating agents (17% 6%; HR, 2.46; < .01), anthracyclines (20% 8%; HR, 2.86; < .001), epipodophyllotoxins (23% 1%; HR, 12.20; < .001), or platinums (46% 7%; HR, 8.58; < .01). This PRS also significantly modified epipodophyllotoxin-related SMN risk among nonirradiated AFR survivors (n = 414; < .01). Improvements in prediction attributable to the PRS were greatest for epipodophyllotoxin-exposed (AUC, 0.71 0.63) and platinum-exposed (AUC,0.68 0.58) survivors.
CONCLUSION
A pleiotropic cancer PRS has strong potential for improving SMN clinical risk stratification among nonirradiated survivors treated with specific chemotherapies. A polygenic risk screening approach may be a valuable complement to an early screening strategy on the basis of treatments and rare cancer-susceptibility mutations.
Topics: Adult; Child; Humans; Female; Cohort Studies; Cancer Survivors; Podophyllotoxin; Neoplasms, Second Primary; Breast Neoplasms; Risk Factors
PubMed: 37459583
DOI: 10.1200/JCO.23.00428