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1.
Nature ; 598(7882): 682-687, 2021 10.
Article in English | MEDLINE | ID: mdl-34671158

ABSTRACT

Tumours use various strategies to evade immune surveillance1,2. Immunotherapies targeting tumour immune evasion such as immune checkpoint blockade have shown considerable efficacy on multiple cancers3,4 but are ineffective for most patients due to primary or acquired resistance5-7. Recent studies showed that some epigenetic regulators suppress anti-tumour immunity2,8-12, suggesting that epigenetic therapies could boost anti-tumour immune responses and overcome resistance to current immunotherapies. Here we show that, in mouse melanoma models, depletion of KDM5B-an H3K4 demethylase that is critical for melanoma maintenance and drug resistance13-15-induces robust adaptive immune responses and enhances responses to immune checkpoint blockade. Mechanistically, KDM5B recruits the H3K9 methyltransferase SETDB1 to repress endogenous retroelements such as MMVL30 in a demethylase-independent manner. Derepression of these retroelements activates cytosolic RNA-sensing and DNA-sensing pathways and the subsequent type-I interferon response, leading to tumour rejection and induction of immune memory. Our results demonstrate that KDM5B suppresses anti-tumour immunity by epigenetic silencing of retroelements. We therefore reveal roles of KDM5B in heterochromatin regulation and immune evasion in melanoma, opening new paths for the development of KDM5B-targeting and SETDB1-targeting therapies to enhance tumour immunogenicity and overcome immunotherapy resistance.


Subject(s)
DNA-Binding Proteins/metabolism , Gene Silencing , Histone-Lysine N-Methyltransferase/metabolism , Jumonji Domain-Containing Histone Demethylases/metabolism , Melanoma/immunology , Retroelements , Tumor Escape , Animals , Cell Line, Tumor , Epigenesis, Genetic , Heterochromatin , Humans , Interferon Type I/immunology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Nuclear Proteins , Repressor Proteins
2.
Breast Cancer Res Treat ; 192(3): 517-527, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35107714

ABSTRACT

PURPOSE: Patients diagnosed with ductal carcinoma in situ (DCIS) face trade-offs when deciding among different treatments, including surgery, radiation, and endocrine therapy. A less chosen option is active monitoring. While evidence from clinical trials is not yet available, observational studies show comparable results for active monitoring and immediate treatment on cancer outcomes in select subgroups of patients. We developed and tested a web-based decision support tool (DST) to help patients explore current knowledge about DCIS and make an informed choice. METHODS: The DST, an interactive web application, was informed by literature reviews and formative work with patients, breast surgeons, and health communication experts. We conducted iterative interviews to evaluate the DST content among women with and without a history of breast cancer, as well as breast cancer experts. For usability testing, we conducted an online survey among women with and without a history of breast cancer. RESULTS: For content evaluation, 5 women with and 10 women without a history of DCIS were interviewed. The sample included 11 White and 4 non-White women, with a mean age of 64 years. The expert sample consisted of 5 attendings and a physician assistant. The feedback was used to add, clarify, or reorganize information in the DST. For usability testing, 22 participants with a mean age of 61 years were recruited including 15 White and 7 Black women and 6 women with a history of DCIS. The mean usability score was 3.7 out of 5. Most participants (86%) found that the DST provided unbiased information about treatments. To improve usability, we reduced the per-page content and added navigation cues. CONCLUSION: Content and usability evaluation showed that the DST helps patients explore trade-offs of active monitoring and immediate treatment. By adopting a personalized approach, the tool will enable informed decisions aligned with patients' values and expectations.


Subject(s)
Breast Neoplasms , Carcinoma, Intraductal, Noninfiltrating , Breast Neoplasms/diagnosis , Breast Neoplasms/therapy , Carcinoma, Intraductal, Noninfiltrating/diagnosis , Carcinoma, Intraductal, Noninfiltrating/therapy , Female , Humans , Internet , Middle Aged , User-Centered Design , User-Computer Interface
3.
Eur J Vasc Endovasc Surg ; 63(3): 446-456, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34887206

ABSTRACT

OBJECTIVE: Intravascular lithotripsy (IVL) is a novel technique for plaque modification during endovascular revascularisation for peripheral artery disease (PAD) with severe calcification. The aim of this paper was to perform a systematic review and meta-analysis of contemporary data to elucidate the efficacy and safety of IVL in lower extremity PAD. DATA SOURCES: A systematic literature search with pre-defined search terms was performed using PubMed, Web of Sciences, OvidSP, and EMBASE. REVIEW METHODS: A meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Patient characteristics, lesion calcification, pre-IVL and post-IVL diameter stenosis, complications, and stent rates were evaluated. RESULTS: Nine studies were included, encompassing a total of 681 patients (769 lesions) with IVL performed for PAD, of which 75.53% (95% confidence interval [CI] 66.08% - 83.03%) of the lesions were reported to have severe calcification. Comparison between pre-IVL and post-IVL diameter stenosis demonstrated a diameter stenosis reduction of 59.3% (95% CI 53.30% - 65.31%). Vascular complications were rare, with flow limiting or type D/E/F dissection occurring in only 1.25% (95% CI 0.60% - 2.61%) of cases. The overall pooled event rate for stent placement was 15.89% (95% CI 5.22% - 39.34%). CONCLUSION: This meta-analysis supports IVL as an effective and safe approach for calcified plaque modification in lower extremity PAD, achieving a diameter stenosis reduction of 59.3% (95% CI 53.30% - 65.31%) with minimal vascular complications. Routine use of this device is not recommended; further high quality evidence is required to elucidate the efficacy of IVL with respect to different clinical characteristics such as lesion location and length, and in comparison with other treatment modalities such as atherectomy.


Subject(s)
Lithotripsy , Peripheral Arterial Disease , Vascular Calcification , Humans , Lithotripsy/adverse effects , Lithotripsy/methods , Lower Extremity , Peripheral Arterial Disease/diagnosis , Peripheral Arterial Disease/therapy , Treatment Outcome , Vascular Calcification/diagnostic imaging , Vascular Calcification/therapy
4.
BMC Med Ethics ; 23(1): 33, 2022 03 25.
Article in English | MEDLINE | ID: mdl-35337310

ABSTRACT

BACKGROUND: In the early stages of the COVID-19 pandemic, many health systems, including those in the UK, developed triage guidelines to manage severe shortages of ventilators. At present, there is an insufficient understanding of how the public views these guidelines, and little evidence on which features of a patient the public believe should and should not be considered in ventilator triage. METHODS: Two surveys were conducted with representative UK samples. In the first survey, 525 participants were asked in an open-ended format to provide features they thought should and should not be considered in allocating ventilators for COVID-19 patients when not enough ventilators are available. In the second survey, 505 participants were presented with 30 features identified from the first study, and were asked if these features should count in favour of a patient with the feature getting a ventilator, count against the patient, or neither. Statistical tests were conducted to determine if a feature was generally considered by participants as morally relevant and whether its mean was non-neutral. RESULTS: In Survey 1, the features of a patient most frequently cited as being morally relevant to determining who would receive access to ventilators were age, general health, prospect of recovery, having dependents, and the severity of COVID symptoms. The features most frequently cited as being morally irrelevant to determining who would receive access to ventilators are race, gender, economic status, religion, social status, age, sexual orientation, and career. In Survey 2, the top three features that participants thought should count in favour of receiving a ventilator were pregnancy, having a chance of dying soon, and having waited for a long time. The top three features that participants thought should count against a patient receiving a ventilator were having committed violent crimes in the past, having unnecessarily engaged in activities with a high risk of COVID-19 infection, and a low chance of survival. CONCLUSIONS: The public generally agreed with existing UK guidelines that allocate ventilators according to medical benefits and that aim to avoid discrimination based on demographic features such as race and gender. However, many participants expressed potentially non-utilitarian concerns, such as inclining to deprioritise ventilator allocation to those who had a criminal history or who contracted the virus by needlessly engaging in high-risk activities.


Subject(s)
COVID-19 , Triage , COVID-19/therapy , Female , Humans , Male , Pandemics , United Kingdom , Ventilators, Mechanical
5.
Hepatology ; 71(4): 1279-1296, 2020 04.
Article in English | MEDLINE | ID: mdl-31469916

ABSTRACT

BACKGROUND AND AIMS: Most tumor cells use aerobic glycolysis (the Warburg effect) to support anabolic growth and promote tumorigenicity and drug resistance. Intriguingly, the molecular mechanisms underlying this phenomenon are not well understood. In this work, using gain-of-function and loss-of-function in vitro studies in patient-derived organoid and cell cultures as well as in vivo positron emission tomography-magnetic resonance imaging animal models, we showed that protein arginine N-methyltransferase 6 (PRMT6) regulates aerobic glycolysis in human hepatocellular carcinoma (HCC) through nuclear relocalization of pyruvate kinase M2 isoform (PKM2), a key regulator of the Warburg effect. APPROACH AND RESULTS: We found PRMT6 to methylate CRAF at arginine 100, interfering with its RAS/RAF binding potential, and therefore altering extracellular signal-regulated kinase (ERK)-mediated PKM2 translocation into the nucleus. This altered PRMT6-ERK-PKM2 signaling axis was further confirmed in both a HCC mouse model with endogenous knockout of PRMT6 as well as in HCC clinical samples. We also identified PRMT6 as a target of hypoxia through the transcriptional repressor element 1-silencing transcription factor, linking PRMT6 with hypoxia in driving glycolytic events. Finally, we showed as a proof of concept the therapeutic potential of using 2-deoxyglucose, a glycolysis inhibitor, to reverse tumorigenicity and sorafenib resistance mediated by PRMT6 deficiency in HCC. CONCLUSIONS: Our findings indicate that the PRMT6-ERK-PKM2 regulatory axis is an important determinant of the Warburg effect in tumor cells, and provide a mechanistic link among tumorigenicity, sorafenib resistance, and glucose metabolism.


Subject(s)
Carcinogenesis , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Nuclear Proteins/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Proto-Oncogene Proteins c-raf/metabolism , Warburg Effect, Oncologic , Active Transport, Cell Nucleus , Cell Nucleus/enzymology , Extracellular Signal-Regulated MAP Kinases/metabolism , Hep G2 Cells , Humans , Methylation , Pyruvate Kinase/metabolism
8.
Emerg Infect Dis ; 23(11): 1852-1855, 2017 11.
Article in English | MEDLINE | ID: mdl-29048294

ABSTRACT

A new recombinant norovirus GII.P16-GII.2 outnumbered pandemic GII.4 as the predominant GII genotype in the winter of 2016-2017 in Hong Kong, China. Half of hospitalized case-patients were older children and adults, including 13 young adults. This emergent norovirus targets a wider age population compared with circulating pandemic GII.4 strains.


Subject(s)
Communicable Diseases, Emerging/epidemiology , Disease Outbreaks , Gastroenteritis/epidemiology , Norovirus/genetics , Adolescent , Adult , Aged , Caliciviridae Infections/epidemiology , Caliciviridae Infections/virology , Child , Child, Preschool , Communicable Diseases, Emerging/virology , Female , Gastroenteritis/virology , Genotype , Hong Kong/epidemiology , Humans , Infant , Male , Middle Aged , Norovirus/isolation & purification , Phylogeny , Reassortant Viruses , Seasons , Young Adult
10.
IEEE J Biomed Health Inform ; 28(5): 2842-2853, 2024 May.
Article in English | MEDLINE | ID: mdl-38446653

ABSTRACT

Kneeosteoarthritis (KOA), as a leading joint disease, can be decided by examining the shapes of patella to spot potential abnormal variations. To assist doctors in the diagnosis of KOA, a robust automatic patella segmentation method is highly demanded in clinical practice. Deep learning methods, especially convolutional neural networks (CNNs) have been widely applied to medical image segmentation in recent years. Nevertheless, poor image quality and limited data still impose challenges to segmentation via CNNs. On the other hand, statistical shape models (SSMs) can generate shape priors which give anatomically reliable segmentation to varying instances. Thus, in this work, we propose an adaptive fusion framework, explicitly combining deep neural networks and anatomical knowledge from SSM for robust patella segmentation. Our adaptive fusion framework will accordingly adjust the weight of segmentation candidates in fusion based on their segmentation performance. We also propose a voxel-wise refinement strategy to make the segmentation of CNNs more anatomically correct. Extensive experiments and thorough assessment have been conducted on various mainstream CNN backbones for patella segmentation in low-data regimes, which demonstrate that our framework can be flexibly attached to a CNN model, significantly improving its performance when labeled training data are limited and input image data are of poor quality.


Subject(s)
Deep Learning , Patella , Tomography, X-Ray Computed , Humans , Patella/diagnostic imaging , Tomography, X-Ray Computed/methods , Algorithms , Image Processing, Computer-Assisted/methods , Neural Networks, Computer
11.
J Orthop Translat ; 45: 100-106, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38524869

ABSTRACT

Osteoarthritis (OA) is one of the fast-growing disability-related diseases worldwide, which has significantly affected the quality of patients' lives and brings about substantial socioeconomic burdens in medical expenditure. There is currently no cure for OA once the bone damage is established. Unfortunately, the existing radiological examination is limited to grading the disease's severity and is insufficient to precisely diagnose OA, detect early OA or predict OA progression. Therefore, there is a pressing need to develop novel approaches in medical image analysis to detect subtle changes for identifying early OA development and rapid progressors. Recently, radiomics has emerged as a unique approach to extracting high-dimensional imaging features that quantitatively characterise visible or hidden information from routine medical images. Radiomics data mining via machine learning has empowered precise diagnoses and prognoses of disease, mainly in oncology. Mounting evidence has shown its great potential in aiding the diagnosis and contributing to the study of musculoskeletal diseases. This paper will summarise the current development of radiomics at the crossroads between engineering and medicine and discuss the application and perspectives of radiomics analysis for OA diagnosis and prognosis. The translational potential of this article: Radiomics is a novel approach used in oncology, and it may also play an essential role in the diagnosis and prognosis of OA. By transforming medical images from qualitative interpretation to quantitative data, radiomics could be the solution for precise early OA detection, progression tracking, and treatment efficacy prediction. Since the application of radiomics in OA is still in the early stages and primarily focuses on fundamental studies, this review may inspire more explorations and bring more promising diagnoses, prognoses, and management results of OA.

12.
Osteoarthr Cartil Open ; 6(2): 100448, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38440779

ABSTRACT

Objective: Knee replacement (KR) is the last-resort treatment for knee osteoarthritis. Although radiographic evidence of tibiofemoral joint has been widely adopted for prognostication, patellofemoral joint has gained little attention and may hold additional value for further improvements. We aimed to quantitatively analyse patellofemoral joint through radiomics analysis of lateral view radiographs for improved KR risk prediction. Design: From the Multicenter Osteoarthritis Study dataset, we retrospectively retrieved the initial-visit lateral left knee radiographs of 2943 patients aged 50 to 79. They were split into training and test cohorts at a 2:1 ratio. A comprehensive set of radiomic features were extracted within the best-performing subregion of patellofemoral joint and combined into a radiomics score (RadScore). A KR risk score, derived from Kellgren-Lawrence grade (KLG) of tibiofemoral joint and RadScore of patellofemoral joint, was developed by multivariate Cox regression and assessed using time-dependent area under receiver operating characteristic curve (AUC). Results: While patellofemoral osteoarthritis (PFOA) was insignificant during multivariate analysis, RadScore was identified as an independent risk factor (multivariate Cox p-value < 0.001) for KR. The subgroup analysis revealed that RadScore was particularly effective in predicting rapid progressor (KR occurrence before 30 months) among early- (KLG < 2) and mid-stage (KLG â€‹= â€‹2) patients. Combining two joints radiographic information, the AUC reached 0.89/0.87 for predicting 60-month KR occurrence. Conclusions: The RadScore of the patellofemoral joint on lateral radiographs emerges as an independent prognostic factor for improving KR prognosis prediction. The KR risk score could be instrumental in managing progressive knee osteoarthritis interventions.

13.
Osteoarthr Cartil Open ; 6(2): 100461, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38558888

ABSTRACT

Background: Joint space width (JSW) is a traditional imaging marker for knee osteoarthritis (OA) severity, but it lacks sensitivity in advanced cases. We propose tibial subchondral bone area (TSBA), a new CT imaging marker to explore its relationship with OA radiographic severity, and to test its performance for classifying surgical decisions between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) compared to JSW. Methods: We collected clinical, radiograph, and CT data from 182 patients who underwent primary knee arthroplasty (73 UKA, 109 TKA). The radiographic severity was scored using Kellgren-Lawrence (KL) grading system. TSBA and JSW were extracted from 3D CT-reconstruction model. We used independent t-test to investigate the relationship between TSBA and KL grade, and binary logistic regression to identify factors associated with TKA risk. The accuracy of TSBA, JSW and established classification model in differentiating between UKA and TKA was assessed using AUC. Results: All parameters exhibited inter- and intra-class coefficients greater than 0.966. Patients with KL grade 4 had significantly larger TSBA than those with KL grade 3. TSBA (0.708 of AUC) was superior to minimal/average JSW (0.547/0.554 of AUC) associated with the risk of receiving TKA. Medial TSBA, together with gender and Knee Society Knee Score, emerged as independent classification factors in multivariate analysis. The overall AUC of composite model for surgical decision-making was 0.822. Conclusion: Tibial subchondral bone area is an independent imaging marker for radiographic severity, and is superior to JSW for surgical decision-making between UKA and TKA in advanced OA patients.

14.
Healthcare (Basel) ; 12(3)2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38338195

ABSTRACT

This study aimed to adapt and validate the Knee Osteoarthritis Fears and Beliefs Questionnaire (KOFBeQ) for Chinese patients, thereby advancing the understanding of fear-avoidance behaviors. Adopting a cross-sectional design, data were collected for 241 subjects (78.8% women; mean age 68.0 ± 7.8 years) across various healthcare settings in Hong Kong. Exploratory factor analysis resulted in an 11-item questionnaire with three distinct subscales, covering fears and beliefs related to physicians and disease (six items), daily living activities (three items), and sports and leisure activities (two items). The overall Cronbach's α coefficient was 0.86, indicating strong internal consistency. The questionnaire exhibited favorable convergent validity. Confirmatory factor analyses confirmed a good model fit. Test-retest reliability analysis indicated a high intraclass correlation coefficient of 0.93 (95% confidence interval: 0.88, 0.96), and a Bland-Altman plot revealed a slight bias in two measurements (0.97 [0.19]) without a systematic trend. The adapted Chinese version of the KOFBeQ demonstrated robust psychometric properties in terms of validity and reliability, providing an effective tool for surveying Chinese patients with knee osteoarthritis. These findings offer valuable insights for clinicians and patients, aiding in informed decision-making and improved rehabilitation strategies.

15.
Trials ; 25(1): 501, 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39039582

ABSTRACT

BACKGROUND: Glaucoma patients with irreversible visual field loss often experience decreased quality of life, impaired mobility, and mental health challenges. Perceptual learning (PL) and transcranial electrical stimulation (tES) have emerged as promising interventions for vision rehabilitation, showing potential in restoring residual visual functions. The Glaucoma Rehabilitation using ElectricAI Transcranial stimulation (GREAT) project aims to investigate whether combining PL and tES is more effective than using either method alone in maximizing the visual function of glaucoma patients. Additionally, the study will assess the impact of these interventions on brain neural activity, blood biomarkers, mobility, mental health, quality of life, and fear of falling. METHODS: The study employs a three-arm, double-blind, randomized, superiority-controlled design. Participants are randomly allocated in a 1:1:1 ratio to one of three groups receiving: (1) real PL and real tES, (2) real PL and sham tES, and (3) placebo PL and sham tES. Each participant undergoes 10 sessions per block (~ 1 h each), with a total of three blocks. Assessments are conducted at six time points: baseline, interim 1, interim 2, post-intervention, 1-month post-intervention, and 2-month post-intervention. The primary outcome is the mean deviation of the 24-2 visual field measured by the Humphrey visual field analyzer. Secondary outcomes include detection rate in the suprathreshold visual field, balance and gait functions, and electrophysiological and biological responses. This study also investigates changes in neurotransmitter metabolism, biomarkers, self-perceived quality of life, and psychological status before and after the intervention. DISCUSSION: The GREAT project is the first study to assess the effectiveness of PL and tES in the rehabilitation of glaucoma. Our findings will offer comprehensive assessments of the impact of these treatments on a wide range of brain and vision-related metrics including visual field, neural activity, biomarkers, mobility, mental health, fear of falling, and quality of life. TRIAL REGISTRATION: ClinicalTrials.gov NCT05874258 . Registered on May 15, 2023.


Subject(s)
Glaucoma , Quality of Life , Transcranial Direct Current Stimulation , Humans , Transcranial Direct Current Stimulation/methods , Double-Blind Method , Glaucoma/physiopathology , Glaucoma/rehabilitation , Visual Fields/physiology , Randomized Controlled Trials as Topic , Treatment Outcome , Male , Middle Aged , Learning , Aged , Female , Vision, Ocular , Visual Perception , Recovery of Function
16.
Cancer Res ; 84(8): 1303-1319, 2024 04 15.
Article in English | MEDLINE | ID: mdl-38359163

ABSTRACT

The majority of EGFR mutant lung adenocarcinomas respond well to EGFR tyrosine kinase inhibitors (TKI). However, most of these responses are partial, with drug-tolerant residual disease remaining even at the time of maximal response. This residual disease can ultimately lead to relapses, which eventually develop in most patients. To investigate the cellular and molecular properties of residual tumor cells in vivo, we leveraged patient-derived xenograft (PDX) models of EGFR mutant lung cancer. Subcutaneous EGFR mutant PDXs were treated with the third-generation TKI osimertinib until maximal tumor regression. Residual tissue inevitably harbored tumor cells that were transcriptionally distinct from bulk pretreatment tumor. Single-cell transcriptional profiling provided evidence of cells matching the profiles of drug-tolerant cells present in the pretreatment tumor. In one of the PDXs analyzed, osimertinib treatment caused dramatic transcriptomic changes that featured upregulation of the neuroendocrine lineage transcription factor ASCL1. Mechanistically, ASCL1 conferred drug tolerance by initiating an epithelial-to-mesenchymal gene-expression program in permissive cellular contexts. This study reveals fundamental insights into the biology of drug tolerance, the plasticity of cells through TKI treatment, and why specific phenotypes are observed only in certain tumors. SIGNIFICANCE: Analysis of residual disease following tyrosine kinase inhibitor treatment identified heterogeneous and context-specific mechanisms of drug tolerance in lung cancer that could lead to the development of strategies to forestall drug resistance. See related commentary by Rumde and Burns, p. 1188.


Subject(s)
Acrylamides , Carcinoma, Non-Small-Cell Lung , Indoles , Lung Neoplasms , Pyrimidines , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , ErbB Receptors/genetics , Drug Resistance, Neoplasm/genetics , Neoplasm Recurrence, Local/drug therapy , Aniline Compounds/pharmacology , Aniline Compounds/therapeutic use , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Mutation , Basic Helix-Loop-Helix Transcription Factors/genetics
17.
Clin Epigenetics ; 15(1): 36, 2023 03 02.
Article in English | MEDLINE | ID: mdl-36864513

ABSTRACT

BACKGROUND: Selenium, an essential trace element, has previously been investigated as a pro-apoptotic and DNA demethylation agent. It sensitizes the response to chemotherapy in patients who were refractory to cytotoxic agents. Meanwhile, ferroptosis is a novel approach to cancer treatment by triggering cell death and reversing drug resistance. The role of selenium in treating cancer cells harboring druggable oncogenic alterations and its underlying mechanism are largely unknown. RESULTS: We treated lung adenocarcinoma cell lines-EGFR-mutant H1975 (H1975 EGFR p.L858R and p.T790M) and KRAS-mutant H358 (H358 KRAS p.G12C), with sodium selenite to examine its effect on cell apoptosis, ferroptosis, and DNA methylation, as well as its interaction with existing targeted therapy, osimertinib, and adagrasib. We observed selenite to be a dual apoptotic and ferroptotic agent on lung cancer cells, associated with the activation of p38-ATF4-DDIT3 axis in the unfolded protein response. Ferroptosis induction was more remarkable in H1975 than H358. Selenite also altered cellular DNA methylation machinery through downregulating DNMT1 and upregulating TET1, though not as a major mechanism of its activity. Low-dose selenite synergized with osimertinib in EGFR-mutant H1975, and with adagrasib in KRAS-mutant H358, with stronger synergism observed in H1975. CONCLUSION: These results suggest that selenite is a potential apoptotic and ferroptotic drug candidate for the treatment of especially EGFR- and potentially KRAS-mutant lung cancer.


Subject(s)
Lung Neoplasms , Selenium , Humans , Selenious Acid , Proto-Oncogene Proteins p21(ras)/genetics , ErbB Receptors/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , DNA Methylation , Mutation , Protein Kinase Inhibitors , Epigenesis, Genetic , Mixed Function Oxygenases , Proto-Oncogene Proteins/genetics
18.
PLoS One ; 18(11): e0292278, 2023.
Article in English | MEDLINE | ID: mdl-37917641

ABSTRACT

Drugs targeting cyclin-dependent kinases 4 and 6 (CDK4/6) are promising new treatments for melanoma and other solid malignancies. In studies on CDK4/6 inhibitor resistance, protein arginine methyltransferase 5 (PRMT5) regulation of alternative splicing was shown to be an important downstream component of the CDK4/6 pathway. However, the full effects of inhibition of CDK4/6 on splicing events in melanoma and the extent to which they are dependent on PRMT5 has not been established. We performed full-length mRNA sequencing on CHL1 and A375 melanoma cell lines treated with the CDK4/6 inhibitor palbociclib and the PRMT5 inhibitor GSK3326595 and analysed data for differential gene expression and differential pre-mRNA splicing induced by these agents. Changes in gene expression and RNA splicing were more extensive under PRMT5 inhibition than under CDK4/6 inhibition. Although PRMT5 inhibition and CDK4/6 inhibition induced common RNA splicing events and gene expression profiles, the majority of events induced by CDK4/6 inhibition were distinct. Our findings indicate CDK4/6 has the ability to regulate alternative splicing in a manner that is distinct from PRMT5 inhibition, resulting in divergent changes in gene expression under each therapy.


Subject(s)
Alternative Splicing , Melanoma , Humans , Protein-Arginine N-Methyltransferases/metabolism , Cell Line, Tumor , Melanoma/drug therapy , Melanoma/genetics , Melanoma/metabolism , RNA Splicing , Cyclin-Dependent Kinase 4/genetics , Cyclin-Dependent Kinase 4/metabolism
20.
BMC Complement Altern Med ; 12: 160, 2012 Sep 19.
Article in English | MEDLINE | ID: mdl-22992293

ABSTRACT

BACKGROUND: Our ongoing research has revealed that total saponins extracted from the medicinal herb Radix Astragali (AST) exhibits significant growth-inhibitory and proapoptotic effects in human cancer cells. In the present study, the potential of AST in controlling angiogenesis was further investigated with elaboration of the underlying molecular mechanism in human colon cancer cell and tumor xenograft. RESULTS: AST decreased the protein level of VEGF and bFGF in HCT 116 colon cancer cells in a time- and dose-dependent manner. Among the Akt/mTOR signal transduction molecules being examined, AST caused PTEN upregulation, reduction in Akt phosphorylation and subsequent activation of mTOR. AST also suppressed the induction of HIF-1α and VEGF under CoCl2-mimicked hypoxia. These effects were intensified by combined treatment of AST with the mTOR inhibitor rapamycin. Despite this, our data also indicate that AST could attenuate cobalt chloride-evoked COX-2 activation, while such effect on COX-2 and its downstream target VEGF was intensified when indomethacin was concurrently treated. The anti-carcinogenic action of AST was further illustrated in HCT 116 xenografted athymic nude mice. AST significantly suppressed tumor growth and reduced serum VEGF level in vivo. In the tumor tissues excised from AST-treated animals, protein level of p-Akt, p-mTOR, VEGF, VEGFR1 and VEGFR2 was down-regulated. Immunohistochemistry has also revealed that AST effectively reduced the level of COX-2 in tumor sections when compared with that in untreated control. CONCLUSION: Taken together, these findings suggest that AST exerts anti-carcinogenic activity in colon cancer cells through modulation of mTOR signaling and downregulation of COX-2, which together reduce VEGF level in tumor cells that could potentially suppress angiogenesis.


Subject(s)
Astragalus Plant/chemistry , Colonic Neoplasms/drug therapy , Colonic Neoplasms/genetics , Saponins/administration & dosage , Vascular Endothelial Growth Factor A/genetics , Animals , Cell Line, Tumor , Cobalt/adverse effects , Colonic Neoplasms/chemically induced , Colonic Neoplasms/metabolism , Cyclooxygenase 2/genetics , Cyclooxygenase 2/metabolism , Down-Regulation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hypoxia/chemically induced , Hypoxia/drug therapy , Hypoxia/genetics , Hypoxia/metabolism , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism , Vascular Endothelial Growth Factor A/metabolism
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