scholarly journals Toward understanding of the role of reversibility of phenotypic switching in the evolution of resistance to therapy

2018 ◽  
Vol 382 (24) ◽  
pp. 1586-1600
Author(s):  
D. Horvath ◽  
B. Brutovsky
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Meilin Chan ◽  
Licun Wu ◽  
Zhihong Yun ◽  
Trevor D. McKee ◽  
Michael Cabanero ◽  
...  

AbstractMalignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma.


2013 ◽  
Vol 305 (9) ◽  
pp. H1275-H1280 ◽  
Author(s):  
Yuh Fen Pung ◽  
Wai Johnn Sam ◽  
James P. Hardwick ◽  
Liya Yin ◽  
Vahagn Ohanyan ◽  
...  

Coronary collateral growth is a process involving coordination between growth factors expressed in response to ischemia and mechanical forces. Underlying this response is proliferation of vascular smooth muscle and endothelial cells, resulting in an enlargement in the caliber of arterial-arterial anastomoses, i.e., a collateral vessel, sometimes as much as an order of magnitude. An integral element of this cell proliferation is the process known as phenotypic switching in which cells of a particular phenotype, e.g., contractile vascular smooth muscle, must change their phenotype to proliferate. Phenotypic switching requires that protein synthesis occurs and different kinase signaling pathways become activated, necessitating energy to make the switch. Moreover, kinases, using ATP to phosphorylate their targets, have an energy requirement themselves. Mitochondria play a key role in the energy production that enables phenotypic switching, but under conditions where mitochondrial energy production is constrained, e.g., mitochondrial oxidative stress, this switch is impaired. In addition, we discuss the potential importance of uncoupling proteins as modulators of mitochondrial reactive oxygen species production and bioenergetics, as well as the role of AMP kinase as an energy sensor upstream of mammalian target of rapamycin, the master regulator of protein synthesis.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Wang Zhao ◽  
Shui-Ping Zhao ◽  
Yu-Hong Zhao

MicroRNAs (miRNAs) play an essential role in the onset and development of many cardiovascular diseases. Increasing evidence shows that miRNAs can be used as potential diagnostic biomarkers for cardiovascular diseases, and miRNA-based therapy may be a promising therapy for the treatment of cardiovascular diseases. The microRNA-143/-145 (miR-143/-145) cluster is essential for differentiation of vascular smooth muscle cells (VSMCs) and determines VSMC phenotypic switching. In this review, we summarize the recent progress in knowledge concerning the function of miR-143/-145 in the cardiovascular system and their role in cardiovascular diseases. We discuss the potential role of miR-143/-145 as valuable biomarkers for cardiovascular diseases and explore the potential strategy of targeting miR-143 and miR-145.


NAR Cancer ◽  
2020 ◽  
Vol 2 (3) ◽  
Author(s):  
McKenzie K Grundy ◽  
Ronald J Buckanovich ◽  
Kara A Bernstein

Abstract Regulation of homologous recombination (HR) is central for cancer prevention. However, too little HR can increase cancer incidence, whereas too much HR can drive cancer resistance to therapy. Importantly, therapeutics targeting HR deficiency have demonstrated a profound efficacy in the clinic improving patient outcomes, particularly for breast and ovarian cancer. RAD51 is central to DNA damage repair in the HR pathway. As such, understanding the function and regulation of RAD51 is essential for cancer biology. This review will focus on the role of RAD51 in cancer and beyond and how modulation of its function can be exploited as a cancer therapeutic.


Science ◽  
2019 ◽  
Vol 363 (6433) ◽  
pp. 1319-1326 ◽  
Author(s):  
Joel M. Alves ◽  
Miguel Carneiro ◽  
Jade Y. Cheng ◽  
Ana Lemos de Matos ◽  
Masmudur M. Rahman ◽  
...  

In the 1950s the myxoma virus was released into European rabbit populations in Australia and Europe, decimating populations and resulting in the rapid evolution of resistance. We investigated the genetic basis of resistance by comparing the exomes of rabbits collected before and after the pandemic. We found a strong pattern of parallel evolution, with selection on standing genetic variation favoring the same alleles in Australia, France, and the United Kingdom. Many of these changes occurred in immunity-related genes, supporting a polygenic basis of resistance. We experimentally validated the role of several genes in viral replication and showed that selection acting on an interferon protein has increased the protein’s antiviral effect.


Pain Medicine ◽  
2020 ◽  
Vol 21 (10) ◽  
pp. 2059-2060
Author(s):  
Bruce Rothschild

Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 136 ◽  
Author(s):  
Clodagh O’Neill ◽  
Katie Gilligan ◽  
Róisín Dwyer

Extracellular vesicles (EVs) are nanosized particles released by all cells that have been heralded as novel regulators of cell-to-cell communication. It is becoming increasingly clear that in response to a variety of stress conditions, cells employ EV-mediated intercellular communication to transmit a pro-survival message in the tumor microenvironment and beyond, supporting evasion of cell death and transmitting resistance to therapy. Understanding changes in EV cargo and secretion pattern during cell stress may uncover novel, targetable mechanisms underlying disease progression, metastasis and resistance to therapy. Further, the profile of EVs released into the circulation may provide a circulating biomarker predictive of response to therapy and indicative of microenvironmental conditions linked to disease progression, such as hypoxia. Continued progress in this exciting and rapidly expanding field of research will be dependent upon widespread adoption of transparent reporting standards and implementation of guidelines to establish a consensus on methods of EV isolation, characterisation and nomenclature employed.


2016 ◽  
Vol 39 (2) ◽  
pp. 423-437 ◽  
Author(s):  
Zongqi Zhang ◽  
Yizhu Chen ◽  
Tiantian Zhang ◽  
Lingyu Guo ◽  
Wenlong Yang ◽  
...  

Background/Aims: Smooth muscle cells may dedifferentiate into the synthetic phenotype and promote atherosclerosis. Here, we explored the role of myoendothelial gap junctions in phenotypic switching of human coronary artery smooth muscle cells (HCASMCs) co-cultured with human coronary artery endothelial cells (HCAECs) exposed to shear stress. Methods: HCASMCs and HCAECs were seeded on opposite sides of Transwell inserts, and HCAECs were exposed to laminar shear stress of 12 dyn/cm2 or 5 dyn/cm2. The myoendothelial gap junctions were evaluated by using a multi-photon microscope. Results: In co-culture with HCAECs, HCASMCs exhibited a contractile phenotype, and maintained the expression of differentiation markers MHC and H1-calponin. HCASMCs and HCAECs formed functional intercellular junctions, as evidenced by colocalization of connexin(Cx)40 and Cx43 on cellular projections inside the Transwell membrane and biocytin transfer from HCAECs to HCASMCs. Cx40 siRNA and 18-α-GA attenuated protein expression of MHC and H1-calponin in HCASMCs. Shear stress of 5 dyn/cm2 increased Cx43 and decreased Cx40 expression in HCAECs, and partly inhibited biocytin transfer from HCAECs to HCASMCs, which could be completely blocked by Cx43 siRNA or restored by Cx40 DNA transfected into HCAECs. The exposure of HCAECs to shear stress of 5 dyn/cm2 promoted HCASMC phenotypic switching, manifested by morphological changes, decrease in MHC and H1-calponin expression, and increase in platelet-derived growth factor (PDGF)-BB release, which was partly rescued by Cx43 siRNA or Cx40 DNA or PDGF receptor signaling inhibitor. Conclusions: The exposure of HCAECs to shear stress of 5 dyn/cm2 caused the dysfunction of Cx40/Cx43 heterotypic myoendothelial gap junctions, which may be replaced by homotypic Cx43/Cx43 channels, and induced HCASMC transition to the synthetic phenotype associated with the activation of PDGF receptor signaling, which may contribute to shear stress-associated arteriosclerosis.


Author(s):  
Manish Jain ◽  
Nirav Dhanesha ◽  
Prakash Doddapattar ◽  
Manasa K. Nayak ◽  
Liang Guo ◽  
...  

Objective: The role of glycolytic enzyme PKM (pyruvate kinase M) 2 in smooth muscle cell (SMC) phenotype switching and neointimal hyperplasia is poorly understood. We determined the role of PKM2 in SMC phenotype switching and neointimal hyperplasia. Approach and Results: We show that PKM2 is expressed in the SMC-rich neointima of the murine carotid artery and peri-strut areas in bare-metal stented human coronary arteries. PDGF-BB (platelet-derived growth factor-BB) stimulation upregulates the expression of PKM2 in cultured murine and human coronary SMC. To provide conclusive evidence for PKM2 in SMC function, we generated SMC-specific PKM2 −/− mutant strain. We report that PKM2 deletion in SMC reduces injury-induced neointimal hyperplasia by inhibiting SMC proliferation and migration, suppressing synthetic phenotype, and reducing aerobic glycolysis associated with decreased ERK (extracellular signal-regulated kinase), mTOR, and STAT3 (signal transducer and activator of transcription 3) signaling. Furthermore, we show that nuclear PKM2 interacts with STAT3 and β-catenin and regulates transcription of MEK5 (mitogen/extracellular signal-regulated kinase kinase-5), cyclin D1, GLUT1 (glucose transporter 1), and LDHA (lactate dehydrogenase A). Treatment of human coronary SMC with ML265, an activator that induces PKM2 tetramerization and blocks its nuclear translocation, inhibited proliferation, migration, and phenotypic switching. Perivascular application of PKM2 activator reduced neointimal hyperplasia in mice. Conclusions: These findings reveal that PKM2 is a key regulator of SMC function in vascular remodeling and implicates PKM2 as a potential target to reduce neointimal hyperplasia.


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