Posts Tagged ‘H35’
New Whitley Hypoxystation Video Launched
Don Whitley Scientific are proud to present a new video that showcases our wide range of Whitley Hypoxic Workstations. The video also features comments from renowned researchers, explaining how a Whitley Hypoxystation benefits their research.
The video is another addition to a growing YouTube channel which features similar videos showcasing our wide product range and company values, including anaerobic and microaerobic workstations, customer testimonials, an introduction to Don Whitley Scientific and the level of service on offer for our customers.
Researchers featured in this video
Dr Karen Wright – Dr Karen Wright uses a Whitley H35 Hypoxystation in the cell culture laboratory at Lancaster University to expedite a component of her research, namely culturing human gut cells at low physiological levels of oxygen. – Testimonial in full
Dr Michael Cross – Dr Cross and his group use their H35 HEPA Hypoxystation to test cardiovascular drug toxicity in a cardiac spheroid model under physiologically relevant oxygen tensions and also periods of extreme hypoxia/ischemia. – Testimonial in full
Click here to explore the full range of Whitley Hypoxystations
Contact our sales team for more information on 01274 595728 or email sales@dwscientific.co.uk. For the full range of Whitley products, visit our website at www.dwscientific.co.uk
Hallmarks of Cancer: Sustaining Growth and Resisting Cell Death
In part four of our mini-series describing “Hypoxia and the Hallmarks of Cancer”, we look more closely at how researchers are using the Hypoxystation to delineate the Hallmarks Sustaining Growth and Resisting Cell Death.
Hallmarks of Cancer
Resisting Cell Death
The ability of cells to resist cell death under hypoxic conditions is central to the progression of cancer and the acquisition of resistance to chemotherapy so frequently encountered in tumors. Hypoxia in the tumor microenvironment exerts selective pressure favoring cells that have lost the functionality of apoptosis genes and can expand uncontrollably. Hypoxia also contributes to survival by inducing autophagy, in a pathway involving HIF-1, beclin, BNIP3 and BNIP3L, in which cellular autophagy acts to recycle cellular organelles, satisfy metabolic demand and improve hypoxic tolerance. HIF-1 mediates cell-cycle retardation and arrest, causing hypoxic tumor cells to become resistant to radiotherapies. NF-κB, through its effects on myriad transcription factors, for example through inhibition of cell death signalling, is activated by hypoxia and reactive oxygen species, and also promotes cell survival.
- Chen et al. (2017) “Autophagy enhanced the radioresistance of non-small cell lung cancer by regulating ROS level under hypoxia condition” International Journal of Radiation Biology, 2017 DOI: 10.1080/09553002.2017.1325025
www.tandfonline.com/doi/ref/10.1080/09553002.2017.1325025?scroll=top Hypoxystation user - Audas et al. (2016) “Adaptation to Stressors by Systemic Protein Amyloidogenesis” Developmental Cell 39, 155–168, October 24, 2016
www.cell.com/developmental-cell/fulltext/S1534-5807(16)30598-6?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1534580716305986%3Fshowall%3Dtrue Hypoxystation user - Knoll et al. (2016) “Hypoxia regulates TRAIL sensitivity of colorectal cancer cells through mitochondrial autophagy” Oncotarget. 2016 Jul 5;7(27):41488-41504 www.ncbi.nlm.nih.gov/pubmed/27166192 Hypoxystation user
- Mysore et al. (2016) “A DNA binding Molecule Targeting the Adaptive Hypoxic Response in Multiple Myeloma has Potent Anti tumor Activity” Mol Cancer Res March 2016 14:253-266
www.ncbi.nlm.nih.gov/pmc/articles/PMC4794370/ Hypoxystation user - Rey et al. (2016) “Molecular targeting of hypoxia in radiotherapy” Advanced Drug Delivery Reviews 2016
www.sciencedirect.com/science/article/pii/S0169409X16302769 Hypoxystation user - Tan et al. (2016) “Role of Autophagy as a Survival Mechanism for Hypoxic Cells in Tumors” Neoplasia (2016) 18, 347–355
www.ncbi.nlm.nih.gov/pubmed/27292024 Hypoxystation user - Poillet-Perez et al. (2015) “Interplay between ROS and autophagy in cancer cells, from tumor initiation to cancer therapy“ Redox Biology 4, 184–192
www.sciencedirect.com/science/article/pii/S221323171400127X
Sustaining Growth
Cancer is essentially based on the cells’ inability to “stop” when suppressors signal an end to growth, and the compunction to “go” despite a lack of bonafide growth signals. Hypoxia in the context of cancer, in precipitating genomic instability and mutation, results in numerous inactive tumor suppressor genes and activated growth factor genes, such that the combination of constitutive proliferative signaling and mutated cancer genes leads to sustained growth. HIF and NF-κB regulated pathways involving Notch, mTOR, WNT11, CAIX, and IGF-1, among many others, contribute to sustained growth in cancer as regulation of proliferation derails. Induced by hypoxia-regulated proteins, anabolic pathways for nucleotide and lipid synthesis are ramped up and enable the rapid proliferation typical of cancer.
LITERATURE:
- Thienpont et al (2016) “Tumor hypoxia causes DNA hypermethylation by reducing TET activity” Nature 2016 September 01; 537(7618): 63–68.
www.nature.com/nature/journal/v537/n7618/abs/nature19081.html?foxtrotcallback=true Hypoxystation user - Humtsoe et al. (2016) “ErbB3 upregulation by the HNSCC 3D microenvironment modulates cell survival and growth” Oncogene 35, 1554-1564 (24 March 2016)
www.nature.com/onc/journal/v35/n12/full/onc2015220a.html Hypoxystation user - Alam et al. (2016) “HIF2α contributes to antiestrogen resistance via positive bilateral crosstalk with EGFR in breast cancer cells” Oncotarget, Vol. 7, No. 10 2016
www.impactjournals.com/oncotarget/index.php?journal=oncotarget&page=article&op=view&path%5b%5d=7167&pubmed-linkout=1 Hypoxystation user - Adriaens et al. (2016) “Quantitative analysis of ChIP‑seq data uncovers dynamic and sustained H3K4me3 and H3K27me3 modulation in cancer cells” Epigenetics & Chromatin (2016) 9:48
epigeneticsandchromatin.biomedcentral.com/articles/10.1186/s13072-016-0090-4 Hypoxystation user - Hansson et al. (2016) “Overexpression of functional SLC6A3 in clear cell renal cell carcinoma” Clin Cancer Res. 2016 Sep 23
clincancerres.aacrjournals.org/content/23/8/2105.full-text.pdf Hypoxystation user - Mori et al. (2016) “Induction of WNT11 by hypoxia and hypoxia-inducible factor-1α regulates cell proliferation, migration and invasion” Scientific Reports 6:21520
www.nature.com/articles/srep21520
Visit HypOxygen at Society for Redox Biology and Medicine
From November 16-19, HypOxygen will be exhibiting the Hypoxystation at the annual meeting of the SFRBM in San Francisco, please stop by our booth #4
Please visit HypOxygen to find out how ROS (reactive oxygen species) research is benefitting from the physiological conditions cells experience in the Hypoxystation. The story below, from HypOxygen, looks at research into this line of work.
Increased production of ROS, which is both a symptom and a driver of cancer Hallmarks, can push cancer cells over the cliff of oxygen homeostasis. Compounds adding oxidative pressure can thus be utilized for selective tumor therapy. In their paper “Triggering apoptosis in cancer cells with an analogue of cribrostatin 6 that elevates intracellular ROS” , Hypoxystation users Asby et al. describe their approach to chemically modifying a natural compound from marine sponges, cribrostatin 6, to enhance its cytotoxic potential. They synthesized a modified molecule 8-phenylcribrostatin 6 (8PC6) that was both more potent and more selective for breast cancer cells. Co-author Ali Tavassoli from the University of Southampton says, “We study HIF-1, so working in a hypoxic environment is critical. Besides culturing our cells in the H35, we also harvest proteins and collect RNA inside the chamber. The H35 is very easy to use; the touch screen controls are straightforward and intuitive. We have used the workstation to incubate cells in hypoxia for ~5 days, and the atmosphere remains stable over time.”
Annexin V/7-AAD staining indicated that 8PC6 induces apoptosis in cancer cells. Treatment of MCF7 cancer cells with ROS-sensing dyes and siRNA to knock down ROS-protective TIGAR demonstrated that 8PC6 increases intracellular reactive oxygen species, upsetting the delicate redox balance in highly susceptible cancer cells and leading to cell death. Hypothesizing that reduction of the cribrostatin analogue yields a semi-quinone that reacts with molecular oxygen to generate superoxide, Asby’s group decided to withdraw oxygen from the equation by incubating the MCF7 cells in the Hypoxystation at 1% O2. Pre-incubation and subsequent incubation with increasing doses of 8PC6 in normoxia versus hypoxia showed that, indeed, the IC50 was increased up to 46-fold in hypoxia due to lack of oxygen. The Hypoxystation’s closed workstation format and rigorous control of oxygen, CO2, temperature and humidity facilitates authentic cell behavior as in vivo conditions are replicated. Thus, hypoxia in the workstation equated to significant reduction in the intracellular availability of oxygen for the generation of ROS. For research being conducted on highly hypoxic tumors, the workstation atmosphere represents a close approximation of the actual conditions cells encounter.
Professor Patrick Frost from UCLA speaks to HypOxygen
Patrick Frost, a professor at UCLA recently spoke to our US distributor, HypOxygen, about his work and how it is benefitted by the use of a Whitley H35 Hypoxystation. Professor Frost is investigating how the adaptive hypoxic response in mutiple myeloma cells affects tumor progression, hoping to provide insight into the pathology and chemotherapy resistance of this incurable disease.
Patrick Frost has been using the Whitley H35 Hypoxystation for almost 3 years now, and he does not miss bygone days in the lab: “We started out with just a Plexiglas box, with some valves in it, with a front cover just held on magnetically, placed inside an incubator. We would burn through a 50 L tank of nitrogen in 48 hours. I was never convinced that we had the correct level of oxygen in there”.
Now, despite two groups using the H35 intensely at 0.2 % oxygen, that gas bottle can easily last a month. Dr. Frost says, “If we shut the workstation down, the atmosphere stays stable, we don’t lose the hypoxia. It’s been a year since we replaced the CO2 bottle, and the compressed air.” Don Whitley Scientific has conducted gas consumption studies that show the Whitley H35 Hypoxystation “at rest” uses only 3.5 L of nitrogen gas/24 hour period, 47 and 28 times less than other hypoxia workstations. Part of the reason for the stability of that atmosphere is the annealed, thick acrylic build of the Hypoxystation. Dr. Frost states, “It’s pretty robust, it’s survived a move and a forklift and it never sprung a leak throughout. “
Read more about the Patrick Frost’s investigation here.
Cell Press Webinar: Available On Demand
In last month’s Cell Press webinar, Dr Randall Johnson of the University Cambridge and Dr Hannele Ruohola-Baker of the University of Washington spoke about the role of the hypoxic microenvironment in physiological contexts as diverse as cancer, hypertension and stem cell differentiation. Dr. Johnson described the regulatory functions of the HIF-1α and β isoforms on the hypoxia response, specifically on nitric oxide production via the enzymes inducible NO synthase and arginase 1. Inhibition of HIF-1α results in reduced NO production and can actually decrease tumour metastasis, while alterations in HIF-1β have the opposite effect.
Dr. Ruohola-Baker spoke about the transition of naïve to primed stem cells taking place in the hypoxic environment of the uterus, and about the role of HIF-1α and β in the re-programming of somatic to pluripotent stem cells. Metabolic differences in the stem cell states can be traced to epigenetic factors acting on the HIF pathways. Both talks reflected the importance of conducting any type of cell-based research at parameters which mirror the natural biological state, to allow cell functions to proceed consistently.
Whitley H35 Hypoxystation
Don Whitley Scientific, manufacturers of the Hypoxystation, and our American subsidiary, HypOxygen, were honoured to sponsor this Cell Press webinar, and we want to thank Drs. Johnson and Ruohola-Baker for their excellent talks. The Hypoxystation is designed to create hypoxic conditions within a closed temperature and humidity controlled environment and thus enable researchers to culture cells at physiological conditions mimicking the in vivo situation.
You can now listen to the webinar at your convenience. Click here to register for access.
Words by Dr Burga Kalz Fuller.
Hypoxia and Immunity
The upcoming Cell symposium “Cancer, Inflammation and Immunity” will shine a spotlight on research delineating the complex cross-talk between inflammatory processes, immune response and the development of cancer diseases. Don Whitley Scientific will be exhibiting the Whitley H35 Hypoxystation (pictured right), a controlled environment workstation for low oxygen cell culture, at the meeting on June 14-16 in Sitges, Spain.
As we look forward to the conference, Dr Burga Kalz Fuller, Product Manager at our American distributor, HypOxygen, has summarized five interesting and recent papers concerning hypoxia and its role in immunology and cancer research:
In cancer cells exposed to hypoxia, HIF-1α induced expression of programmed cell death ligand PD-L1, which increased the cells’ resistance to CTL-mediated lysis and contributed to tumoral immune escape. This effect was blocked through administration of glyceryl trinitrate (GTN), an agonist of nitric oxide signalling, suggesting that NO mimetica inhibiting PD-L1 may present a novel cancer therapy strategy.
2. “HIF-mediated innate immune responses: cell signaling and therapeutic implications” Harris et al., Hypoxia 2014:2 47–58
Host defense through innate immune cells takes place in a low oxygen environment where functions as diverse as cytokine secretion and pathogen phagocytosis are modulated by HIF’s. This review summarises the roles of HIF’s in acute and chronic immune response and gives a perspective on therapies targeting the HIF pathway.
Hypoxia is characteristic for sites of inflammation and lesion, and monocytes and other immune cells accumulating in these hypoxic areas are specifically stimulated by the low oxygen environment. Raggi et al. investigated the hypoxic transcriptome and describe members of the CD300 superfamily of immunoregulatory cell surface receptors which are up-regulated in hypoxia.
Hypoxia-signaling pathways which trigger HIF expression act in the immune system to modulate host immune function. In this review, Palazon et al. describe the myriad ways oxygen sensing regulates innate and adaptive immunity.
Mueller-Edenborn’s group shed light on signalling pathways regulating hypoxia and inflammatory responses, which exhibit a surprising degree of cross-talk in colon cancer. Hypoxia attenuated proinflammatory responses by inhibiting translocation of NF-κB into the nucleus, demonstrating yet again that both these aspects of the tumour microenvironment influence therapy response.
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