The advanced-stage colon cancer spreads from primary tumor site to distant organs where the colon-unassociated stromal population provides a favorable niche for the growth of tumor cells. The heterocellular interactions between colon cancer cells and colon-unassociated fibroblasts at distant metastatic sites are important, yet these cell-cell interactions for therapeutic strategies for metastatic colon cancer remain underestimated. Recent studies have shown the therapeutic potential of DNA-demethylating epi-drugs 5-azacytidine (AZA) and 5-aza-2'-deoxycytidine (DAC) for the treatment of solid tumors. While the effects of these epi-drugs alone or in combination with other anticancer therapies are well described, the influence of stromal cells and their secretome on cancer cell response to these agents remain elusive. In this study, we determined the effect of normal and senescent colon-unassociated fibroblasts and their conditioned medium on colorectal cancer (CRC) cell response to AZA and DAC using a cell-based DNA demethylation reporter system. Our data show that fibroblasts accelerate cell proliferation and differentially regulate the expression of DNA methylation-regulating enzymes, enhancing DAC-induced demethylation in CRC cells. In contrast, the conditioned medium from senescent fibroblasts that upregulated NF-κB activity altered deoxycytidine kinase levels in drug-untreated CRC cells and abrogated DAC effect on degradation of DNA methyltransferase 1. Similar to 2D cultures, senescent fibroblasts increased DNA demethylation of CRC cells in coculture spheroids, in addition to increasing the stemness of CRC cells. This study presents the first evidence of the effect of normal and senescent stromal cells and their conditioned medium on DNA demethylation by DAC. The data show an increased activity of DAC in high stromal cell cocultures and suggest the potential of the tumor-stroma ratio in predicting the outcome of DNA-demethylating epigenetic cancer therapy.
- Publikační typ
- časopisecké články MeSH
DNA methylation plays a pivotal role in the etiology of cancer by mediating epigenetic silencing of cancer-related genes. Since the relationship between aberrant DNA methylation and cancer has been understood, there has been an explosion of research at developing anti-cancer therapies that work by inhibiting DNA methylation. From the discovery of first DNA hypomethylating drugs in the 1980s to recently discovered second generation pro-drugs, exceedingly large number of studies have been published that describe the DNA hypomethylation-based anti-neoplastic action of these drugs in various stages of the pre-clinical investigation and advanced stages of clinical development. This review is a comprehensive report of the literature published in past 40 years, on so far discovered nucleosidic DNA methylation inhibitors in chronological order. The review will provide a complete insight to the readers about the mechanisms of action, efficacy to demethylate and re-express various cancer-related genes, anti-tumor activity, cytotoxicity profile, stability, and bioavailability of these drugs. The review further presents the far known mechanisms of primary and secondary resistance to azanucleoside drugs. Finally, the review highlights the ubiquitous role of DNA hypomethylating epi-drugs as chemosensitizers and/or priming agents, and recapitulate the combinatorial cancer preventive effects of these drugs with other epigenetic agents, conventional chemo-drugs, or immunotherapies. This comprehensive review analyzes the beneficial characteristics and drawbacks of nucleosidic DNA methylation inhibitors, which will assist the pre-clinical and clinical researchers in the design of future experiments to improve the therapeutic efficacy of these drugs and circumvent the challenges in the path of successful epigenetic therapy.
- MeSH
- antitumorózní látky farmakologie terapeutické užití MeSH
- azacytidin analogy a deriváty farmakologie MeSH
- chemorezistence MeSH
- DNA-(cytosin-5)-methyltransferasa 1 antagonisté a inhibitory MeSH
- lidé MeSH
- metylace DNA účinky léků MeSH
- nukleosidy farmakologie MeSH
- objevování léků * MeSH
- thioguanin farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Aberrant DNA methylation that results in silencing of genes has remained a significant interest in cancer research. Despite major advances, the success of epigenetic therapy is elusive due to narrow therapeutic window. A wide variety of naturally occurring epigenetic agents and synthetic molecules that can alter methylation patterns exist, however, their usefulness in epigenetic therapy remains unknown. This underlines the need for effective tumor models for large-scale screening of drug candidates with potent hypomethylation activity. In this study, we present the development of a cell-based DNA demethylation detection system, which is amenable for high content screening of epigenetic drugs in two-dimensional and three-dimensional cell culture models. Additionally, the detection system also supports the in vivo monitoring of demethylation efficacy of potential lead compounds from in vitro screens in tumor xenografts. The described detection system not only permits the continuous monitoring of demethylation but also of the induced cytostatic/cytotoxic drug effects in live cells, as a function of time. The detection system is fluorescence based and exploits the dominant ability of DNA methylation to inhibit gene transcription, and utilizes FLJ32130 gene, which is silenced on account of promoter hypermethylation in human colorectal cancer. The described work will provide the researchers with an efficient tool for epigenetic drug screens on a high throughput platform and would therefore benefit academic and industrial drug discovery. © 2016 International Society for Advancement of Cytometry.
- MeSH
- antitumorózní látky terapeutické užití MeSH
- epigeneze genetická * MeSH
- kolorektální nádory farmakoterapie genetika MeSH
- lidé MeSH
- metylace DNA účinky léků MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- proliferace buněk účinky léků MeSH
- promotorové oblasti (genetika) MeSH
- regulace genové exprese u nádorů účinky léků MeSH
- xenogenní modely - testy antitumorózní aktivity MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects normal functions of the brain. Currently, AD is one of the leading causes of death in developed countries and the only one of the top ten diseases without a means to prevent, cure, or significantly slow down its progression. Therefore, newer therapeutic concepts are urgently needed to improve survival and the quality of life of AD patients. Microtubule affinity-regulating kinases (MARKs) regulate tau-microtubule binding and play a crucial role in neurons. However, their role in hyperphosphorylation of tau makes them potential druggable target for AD therapy. Despite the relevance of MARKs in AD pathogenesis, only a few small molecules are known to have anti-MARK activity and not much has been done to progress these compounds into therapeutic candidates. But given the diverse role of MARKs, the specificity of novel inhibitors is imperative for their successful translation from bench to bedside. In this regard, a recent co-crystal structure of MARK4 in association with a pyrazolopyrimidine-based inhibitor offers a potential scaffold for the development of more specific MARK inhibitors. In this manuscript, we review the biological role of MARKs in health and disease, and draw attention to the largely unexplored area of MARK inhibitors for AD.
- MeSH
- Alzheimerova nemoc farmakoterapie metabolismus patologie MeSH
- antigeny bakteriální terapeutické užití MeSH
- azepiny chemie terapeutické užití MeSH
- bakteriální proteiny terapeutické užití MeSH
- inhibitory proteinkinas chemie terapeutické užití MeSH
- lidé MeSH
- methylenová modř chemie terapeutické užití MeSH
- neurony metabolismus MeSH
- protein-serin-threoninkinasy antagonisté a inhibitory metabolismus MeSH
- proteiny tau antagonisté a inhibitory metabolismus MeSH
- pyrazoly chemie terapeutické užití MeSH
- pyridiny chemie terapeutické užití MeSH
- pyrroly chemie terapeutické užití MeSH
- staurosporin chemie terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Publikační typ
- abstrakt z konference MeSH
