Dioscin induces demethylation of DAPK-1 and RASSF-alpha genes via the antioxidant capacity, resulting in apoptosis of bladder cancer T24 cells

DNA methylation at CpG rich regions often occurs at tumor suppressor gene promoters, resulting in reduced gene expression and final carcinogenesis. Hypermethylation of tumor suppressor genes, including DAPK-1 and RASSF-1α genes, have been found in patients with bladder carcinoma (BC) in some western countries. Reactive oxygen species (ROS) was reported to play a causative role in gene hypermethylation. In this study, we detected the methylation status and expression of DAPK1 and RASSF-1α genes in tissue samples from Chinese BC pa- tients, using methylation-specific PCR, reverse transcription PCR and western blotting. Further, we examined the ability of dioscin, a natural antioxidant, to regulate methylation status and expression of DAPK-1 and RASSF-1α genes in BC cell lines. In our results, DAPK-1 and RASSF-1α genes showed higher methylation level and lower express level in BC tissues than matched normal tissues. Treatment with dioscin decreased viability of BC 5637 and T24 cells, but not non-cancer bladder epithelial cell, SV-HUC-1. Dioscin triggered demethylation of DAPK1 and RASSF-1α genes in T24 cells and increased the gene and protein expression in 5637 and T24 cells. Both dioscin and substituted antioxidants (N-acetyl cysteine and Vitamin E) decreased intracellular ROS, but the effect of dioscin was abolished by adding H2O2. Similar to dioscin, the substituted antioxidants also induced the gene demethylation and T24 cell apoptosis. Co-treatment with dioscin and H2O2 had no such effects. Collectively, di- of DAPK-1 and RASSF-1α genes via the antioxidant capacity, resulting in apoptosis of bladder cancer T24 cells or inhibitory cell viability

Shear stress attenuates apoptosis due to TNFα, oxidative stress, and serum depletion via death-associated protein kinase (DAPK) expression

BACKGROUND: Misdirected apoptosis in endothelial cells participates in the development of pathological conditions such as atherosclerosis. Tight regulation of apoptosis is necessary to ensure normal cell function. The rate of cell turnover is increased at sites prone to lesion development. Laminar shear stress is protective against atherosclerosis, and helps suppress apoptosis induced by cytokines, oxidative stress, and serum depletion. Current Studies have shown that the pro-apoptotic DAPK expression and function to be regulated in part by shear stress, and that shearing cells already treated with cytokine tumor necrosis factor (TNF) α significantly reduced apoptosis. We investigate further the suppression of endothelial apoptosis by shear stress with other apoptotic triggers, and the involvement of DAPK and caspase 3/7. RESULTS: We have shown that exposure to shear stress (12 dynes/cm(2) for 6 hrs) suppressed endothelial apoptosis triggered by cytokine (TNFα), oxidative stress (H2O2), and serum depletion, either before or after a long term (18 hr) induction. This is correlated with a parallel decrease of DAPK expression and caspase activity compared to non-sheared cells. We found similar modulation of DAPK and apoptosis by shear stress with other pro-apoptotic signals. Changes in DAPK and caspase 3/7 are directly correlated to changes in apoptosis. Interestingly, shear stress applied to cells prior to induction with apoptosis agents resulted in a higher suppression of apoptosis and DAPK and caspase activity, compared to applying shear stress post induction. This is correlated with a higher expression and activation of DAPK in cells sheared at the end of 24-hr experiment. Also, shear stress alone also induced higher apoptosis and DAPK expression, and the effect is sustained even after 18 hrs incubation in static condition, compared to non-sheared cells. CONCLUSIONS: Overall, we show that laminar shear stress inhibits various apoptosis pathways by modulating DAPK activity, as well as caspase activation, in a time-dependent manner. Shear stress could target DAPK as a converging point to exert its effects of suppressing endothelial apoptosis. The temporal shear stress stimulation of DAPK and its role in different apoptosis pathways may help identify key mechanisms of the endothelial mechanotransduction pathway

Epigenetics in diagnosis, prognostic assessment and treatment of cancer:An update

Cancer cells contain multiple genetic and epigenetic changes. The relative specificity of many epigenetic changes for neoplastic cells has allowed the identification of diagnostic, prognostic and predictive biomarkers for a number of solid tumors and hematological malignancies. Moreover, epigenetically-acting drugs are already in routine use for cancer and numerous additional agents are in clinical trials. Here, we review recent progress in the development and application of epigenetic strategies for the diagnosis, risk stratification and treatment of cancer

Evaluation of Cu containing amine oxidase is sera of gastric cancer patients

Introduction: Cupper containing amine oxidase (Cu-AO) catalyzes the deamination of primary amines to corresponding aldehydes in the presence of oxygen with the subsequent release of ammonia and hydrogen peroxide. Cu-AO also is known as soluble vascular adhesion molecule-1 (sVAP-1). It has been shown that the serum level of Cu-AO changes in various cancers. Literature review showed that there was no information on Cu-AO serum concentration among Iranians as well as in gastric cancer patients. The present study was conducted with two major aims 1) determination of Cu-AO concentration in healthy people; 2) to investigate the changes of the enzyme in gastric patients compared to control. Material and method: This investigation as a case–control study included 200 healthy and GC patient volunteers referred to Aras Clinic in Imam Khomeini Hospital. Blood samples were collected and serum was separated and stored at −70 °C until ELISA examinations. Questionnaires were distributed and filled out by both patients and healthy people. Results and conclusion: Present investigation showed that there is no significant change in serum level of Cu-AO in regard to sex, age, smoking and BMI. The serum level of Cu-AO in healthy subjects was higher than values reported in other countries. Whether these finding would open new sights into etiology of high incidence of GC in Ardabil province needs further investigations. Cu-AO levels in serum show a significant decrease in GC patients in relative to controls, this decline in Cu-AO might have been used as a biomarker for gastric cancer diagnosis

Salivary Biomarkers for Oral Squamous Cell Carcinoma Diagnosis and Follow-Up: Current Status and Perspectives

Oral cancer is the sixth most common cancer type in the world, and 90% of it is represented by oral squamous cell carcinoma (OSCC). Despite progress in preventive and therapeutic strategies, delay in OSCC diagnosis remains one of the major causes of high morbidity and mortality; indeed the majority of OSCC has been lately identified in the advanced clinical stage (i.e., III or IV). Moreover, after primary treatment, recurrences and/or metastases are found in more than half of the patients (80% of cases within the first 2 years) and the 5-year survival rate is still lower than 50%, resulting in a serious issue for public health. Currently, histological investigation represents the “gold standard” of OSCC diagnosis; however, recent studies have evaluated the potential use of non-invasive methods, such as “liquid biopsy,” for the detection of diagnostic and prognostic biomarkers in body fluids of oral cancer patients. Saliva is a biofluid containing factors such as cytokines, DNA and RNA molecules, circulating and tissue- derived cells, and extracellular vesicles (EVs) that may be used as biomarkers; their analysis may give us useful information to do early diagnosis of OSCC and improve the prognosis. Therefore, the aim of this review is reporting the most recent data on saliva biomarker detection in saliva liquid biopsy from oral cancer patients, with particular attention to circulating tumor DNA (ctDNA), EVs, and microRNAs (miRNAs). Our results highlight that saliva liquid biopsy has several promising clinical uses in OSCC management; it is painless, accessible, and low cost and represents a very helpful source of diagnostic and prognostic biomarker detection. Even if standardized protocols for isolation, characterization, and evaluation are needed, recent data suggest that saliva may be successfully included in future clinical diagnostic processes, with a considerable impact on early treatment strategies and a favorable outcome

CYP1B1 promotes tumorigenesis via altered expression of CDC20 and DAPK1 genes in renal cell carcinoma.

BackgroundCytochrome P450 1B1 (CYP1B1) has been shown to be up-regulated in many types of cancer including renal cell carcinoma (RCC). Several reports have shown that CYP1B1 can influence the regulation of tumor development; however, its role in RCC has not been well investigated. The aim of the present study was to determine the functional effects of CYP1B1 gene on tumorigenesis in RCC.MethodsExpression of CYP1B1 was determined in RCC cell lines, and tissue microarrays of 96 RCC and 25 normal tissues. To determine the biological significance of CYP1B1 in RCC progression, we silenced the gene in Caki-1 and 769-P cells by RNA interference and performed various functional analyses.ResultsFirst, we confirmed that CYP1B1 protein expression was significantly higher in RCC cell lines compared to normal kidney tissue. This trend was also observed in RCC samples (p < 0.01). Interestingly, CYP1B1 expression was associated with tumor grade and stage. Next, we silenced the gene in Caki-1 and 769-P cells by RNA interference and performed various functional analyses to determine the biological significance of CYP1B1 in RCC progression. Inhibition of CYP1B1 expression resulted in decreased cell proliferation, migration and invasion of RCC cells. In addition, reduction of CYP1B1 induced cellular apoptosis in Caki-1. We also found that these anti-tumor effects on RCC cells caused by CYP1B1 depletion may be due to alteration of CDC20 and DAPK1 expression based on gene microarray and confirmed by real-time PCR. Interestingly, CYP1B1 expression was associated with CDC20 and DAPK1 expression in clinical samples.ConclusionsCYP1B1 may promote RCC development by inducing CDC20 expression and inhibiting apoptosis through the down-regulation of DAPK1. Our results demonstrate that CYP1B1 can be a potential tumor biomarker and a target for anticancer therapy in RCC

Autophagy: a cellular stres and a cell death mechanism (Otofaji: bir hücresel stres yanıtı ve ölüm mekanizması)

Autophagy is a physiological phenomenon responsible for the degradation of long-lived proteins, organelles and cytoplasmic fragments. It allows cellular recycling following lysosomal degradation and helps the cell to survive various stress conditions including starvation, growth factor and oxidative stress. Paradoxically, under certain conditions autophagy may kill the cell through a caspase-independent, non-apoptotic type of cell death (Type II cell death or autophagic cell death). Several lines of evidence point out to a direct connection between classical apoptosis and autophagy. Molecular mechanisms of apoptosis-autophagy connection start to be unraveled. The cross-talk between autophagy and apoptosis seems quite complex but certainly is critical for the development of novel diagnosis, follow-up and treatment modalities in health problems such as cancer, infections and neurodegenerative diseases

TIMP3 and CCNA1 hypermethylation in HNSCC is associated with an increased incidence of second primary tumors

Background: Hypermethylation in the promoter regions is associated with the suppression of gene expression and has been considered a potential molecular marker for several tumor types, including head and neck squamous cell carcinomas (HNSCC).Methods: To evaluate the gene hypermethylation profile as a prognostic marker, this retrospective study used a QMSP approach to determine the methylation status of 19 genes in 70 HNSCC patients.Results: the methylation profile analysis of primary HNSCC revealed that genes CCNA1, DAPK, MGMT, TIMP3 and SFRP1 were frequently hypermethylated, with high specificity and sensitivity. TIMP3 and CCNA1 hypermethylation was significantly associated with lower rates of second primary tumor-free survival (p = 0.007 and p = 0.001; log-rank test, respectively).Conclusion: This study, for the first time, presents CCNA1 and TIMP3 hypermethylation as a helpful tool to identify HNSCC subjects at risk of developing second primary carcinomas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Biol Sci, Lab Mol Canc Biol, BR-04039020 São Paulo, BrazilBarretos Canc Hosp, Stat & Epidemiol Ctr, BR-14784400 Barretos, BrazilAC Camargo Hosp, Dept Head & Neck Surg, BR-01509010 São Paulo, BrazilBarretos Canc Hosp, Dept Head & Neck Surg, BR-14784400 Barretos, BrazilDuke NUS Grad Med Sch, Canc & Stem Cell Biol Program, Singapore 169857, SingaporeUniversidade Federal de São Paulo, Dept Biol Sci, Lab Mol Canc Biol, BR-04039020 São Paulo, BrazilWeb of Scienc

Survie cellulaire : différences et différenciation

Les mécanismes de la régulation de la survie cellulaire et de l’apoptose sont d’une nature très complexe, impliquant de nombreux intervenants et de nombreuses voies de signalisation aussi bien dans la prise de décision de survivre (ou de mourir) que dans l’exécution de l’apoptose proprement dite. Il en va de même pour l’anoïkose, une forme d’apoptose régulée principalement par les interactions cellule-matrice extracellulaire médiées par les intégrines. Or, la survie cellulaire, l’apoptose et l’anoïkose comportent des différences mécanistiques supplémentaires dépendant des tissus et des types cellulaires spécifiquement concernés. Incidemment, des études de la survie cellulaire effectuées dans un tissu particulier, l’épithélium intestinal humain, ont mis au jour un degré additionnel de complexité dans la régulation de ces processus : l’activation de mécanismes distincts selon l’état de différenciation cellulaire.The regulatory mechanisms of cell survival and apoptosis are very complex in nature, implicating numerous players and signaling pathways not only in the decision-making process of surviving (or dying), but as well as in the execution of apoptosis itself. The same complex nature applies with regards to anoikis, a form of apoptosis that is largely regulated by integrin-mediated, cell-extracellular matrix interactions. However, cell survival, apoptosis and anoikis also happen to implicate further mechanistic distinctions according to the specific tissue and/or cell type concerned. Incidentally, recent studies in a particular tissue, the human intestinal epithelium, have unearthed yet another layer of complexity in the regulation of these three cellular processes, namely the implication of differentiation state-specific mechanisms. Although our understanding of the molecular underpinnings of this new concept of differentiation state-distinct regulation of cell survival, apoptosis and/or anoikis is in its infancy, there is already evidence that such principle applies as well to cell types other than intestinal epithelial cells. Further studies on the differentiation state-specific regulation of these three cellular processes, either under normal or physiopathological situations, should prove crucial in increasing our understanding of pathologies which implicate a dysregulation of apoptosis and/or anoikis – such as cancer

The DAXX co-repressor is directly recruited to active regulatory elements genome-wide to regulate autophagy programs in a model of human prostate cancer.

While carcinoma of the prostate is the second most common cause of cancer death in the US, current methods and markers used to predict prostate cancer (PCa) outcome are inadequate. This study was aimed at understanding the genome-wide binding and regulatory role of the DAXX transcriptional repressor, recently implicated in PCa. ChIP-Seq analysis of genome-wide distribution of DAXX in PC3 cells revealed over 59,000 DAXX binding sites, found at regulatory enhancers and promoters. ChIP-Seq analysis of DNA methyltransferase 1 (DNMT1), which is a key epigenetic partner for DAXX repression, revealed that DNMT1 binding was restricted to a small number of DAXX sites. DNMT1 and DAXX bound close to transcriptional activator motifs. DNMT1 sites were found to be dependent on DAXX for recruitment by analyzing DNMT1 ChIP-Seq following DAXX knockdown (K/D), corroborating previous findings that DAXX recruits DNMT1 to repress its target genes. Massively parallel RNA sequencing (RNA-Seq) was used to compare the transcriptomes of WT and DAXX K/D PC3 cells. Genes induced by DAXX K/D included those involved in autophagy, and DAXX ChIP-Seq peaks were found close to the transcription start sites (TSS) of autophagy genes, implying they are more likely to be regulated by DAXX. In conclusion, DAXX binds active regulatory elements and co-localizes with DNMT1 in the prostate cancer genome. Given DAXX's putative regulatory role in autophagy, future studies may consider DAXX as a candidate marker and therapeutic target for prostate cancer