Karin Spaink posted this Thursday on the Dutch forum dampforum.nu. Somewhat of a chin-drop to not see the issue also picked up here by now. Her comments and additions in italics, translated from Dutch. The rest attributed by source.
A summary of a new study, published in Oral Oncology 4 Nov 2015, was just posted on Reddit. It suggests vaping is not that harmless, accelerating the degeneration of DNA and diminishing the longevity and vitality of cells, even when using e-liquid without nicotine. Vaping still is much, much safer than smoking, but probably not a great idea for a non-smoker.
PubMed link [summary]: http://www.sciencedirect.com/science/article/pii/S1368837515003620
Full article [just 7 days, so hurry] Wikisend: free file sharing service
1. Summary on Reddit:
Electronic cigarettes induce DNA strand breaks and cell death independently of nicotine in cell lines
Vicky Yua, Mehran Rahimya, Avinaash Korrapatia, Yinan Xuana, Angela E. Zoua, Aswini R. Krishnana, Tzuhan Tsuib, Joseph A. Aguilerac, Sunil Advanic, Laura E. Crotty Alexanderb, Kevin T. Brumunda, Jessica Wang-Rodrigueze, Weg M. Ongkekoa.
Highlights
• Normal and HNSCC cell lines were cultured in e-cigarette vapor pulled through media.
• Cell cultures exposed to e-cigarette vapor show increased DNA double strand breaks.
• E-cigarette vapor induces increased cell death as compared to control.
• E-cigarette vapor decreases clonogenic survival as compared to control.
Objectives
Evaluate the cytotoxicity and genotoxicity of short- and long-term e-cigarette vapor exposure on a panel of normal epithelial and head and neck squamous cell carcinoma (HNSCC) cell lines.
Materials and methods
HaCaT, UMSCC10B, and HN30 were treated with nicotine-containing and nicotine-free vapor extract from two popular e-cigarette brands for periods ranging from 48 h to 8 weeks. Cytotoxicity was assessed using Annexin V flow cytometric analysis, trypan blue exclusion, and clonogenic assays. Genotoxicity in the form of DNA strand breaks was quantified using the neutral comet assay and γ-H2AX immunostaining.
Results
E-cigarette-exposed cells showed significantly reduced cell viability and clonogenic survival, along with increased rates of apoptosis and necrosis, regardless of e-cigarette vapor nicotine content. They also exhibited significantly increased comet tail length and accumulation of γ-H2AX foci, demonstrating increased DNA strand breaks.
Conclusion
E-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent. Further assessment of the potential carcinogenic effects of e-cigarette vapor is urgently needed.
PubMed link [summary]: http://www.sciencedirect.com/science/article/pii/S1368837515003620
Full article [just 7 days, so hurry] Wikisend: free file sharing service
1. Summary on Reddit:
Electronic cigarettes induce DNA strand breaks and cell death independently of nicotine in cell lines. - PubMed
tl;dr: e-cigarette smoke vapor is potentially carcinogenic causing DNA damage (with or without nicotine) and stops cells from reproducing (proliferating) at a normal rate. AKA potentially carcinogenic, and kills lung cells; further study is needed to confirm this. Still better than smoking though
In this experiment, they took epithelial cells (stated above) from the skin (HaCat cell line) and cancerous cells (HNSCC) taken from the oropharynx (laryngeal tumor [HN30]and metastatic lymph node[UMSCC10B]) to test the effects e-liquid mixed at a 30/70 pg/vg ratio on cells and cancerous cells (likely to occur in ex-smokers). They exposed the experimental groups to vapor extract and marlboro red extract and compared this to the control group.
Neutral comet assay: tests tail length to find extent of DNA damage. DNA damage=potentially carcinogenic
Results: ranking from good to bad: control group-healthy cells, no nic e-liquid, nicotine alone, nic+e-liquid (no test group for cigarettes). nic+e-liquid caused up to 1.5x damage when compared to the control group.
H2AX immunostaining: tests amount of DNA double strand breaks (DSB) important because: DSB=potentially carcinogenic
Results: both e-liquids caused DSB's in HaCat cells (1.5x for no nicotine e-liquids and 3x for nicotine e-liquids) and HSNCC lines. They downplay the severity of cigarette smoke but it caused the most amount of DSB's. Best to worst: control, no-nic e-liquids, nic+e-liq/nicotine, cigarettes
Cell cycle analysis (flow cytochemistry): DNA content is analyzed to see if cell cycle is normal/ cells are undergoing normal growth. Cells were treated with e-cig vapor extract for 1 week.
Results: there was a significant increase in cell death during the G1 phase for UMSCC10B and G2 phase for HN30 cells (cancerous cells) unrelated to nicotine content in juices. Put simply, cell's have a hard time growing and reproducing (separating)
Trypin blue: counts cells to see if there are cells dying or if it's not reproducing as much as normal
Results: compared to normal cell proliferation conditions, there was a 5x increase in cell death for non-nicotine juices and a 10x increase in cell death for nicotine juices. Looking at their pictures, cigarettes/nicotine looks just as bad as nicotine e-liquid if not worse but it's just pictures, no way of telling for certain until I can get a cell count.
clonogenic assay: treating HNSCC cells to see if they can survive
Results: increase in cell death ranked best to worst: control healthy cells, no nicotine e-liquid, nicotine e-liquid, cigarette, nicotine.
Apoptotic Assay (annexin v): tests to see the stages/method of cell death. There are two forms, apoptosis which is normal programmed cell death/suicide, and necrosis which is like dropping a balloon in acid and having it dissolve the cell wall and kill the cell (unnatural).
Results: In HaCat (non-cancerous) testing, cells treated with e-liquid experienced an increase in cell apoptosis (suicide) and necrosis (death and disassociation like being blown up). Cigarettes tended to put cells into late apoptosis (induced suicide) whereas e-liquid had more live cells but still had more cells in apoptosis and necrosis than control. The numbers for this test are a little all over the place and not really in line with expected values (in my opinion) so I would disregard this test or take it with a grain of salt Basically, healthy cells die less, e-liquid causes more cell death through necrosis and apoptosis, and cigarettes causes a large amount to go through apoptosis (natural/programmed cell death) but not a lot to go through necrosis (90% of the cells are going through apoptosis, there aren't any cells left to go through necrosis)
ELI5: This study says vaping causes lung and throat cell death and can possibly be carcinogenic (breaks DNA strands). It still show's that vaping is much better than smoking marlboro red's. No smoke is better than any smoke but vaping is better than smoking. More study is needed to see how this affects us and our lungs in vitra.
Edit: everything's posted, I'll proofread later and make sure everything's as right as I can get it. Normally i'm the one laughing at these joke studies but from first glance, this seems to be an extremely robust experiment from a trusted source. That being said, it is slightly biased in that it doesn't say just how harmful cigarettes are compared to vaping but it just tells us that there are risks to vaping. There may be errors (not an md), don't hesitate to message me for questions and whatnots.
2. Summary on PubMed:tl;dr: e-cigarette smoke vapor is potentially carcinogenic causing DNA damage (with or without nicotine) and stops cells from reproducing (proliferating) at a normal rate. AKA potentially carcinogenic, and kills lung cells; further study is needed to confirm this. Still better than smoking though
In this experiment, they took epithelial cells (stated above) from the skin (HaCat cell line) and cancerous cells (HNSCC) taken from the oropharynx (laryngeal tumor [HN30]and metastatic lymph node[UMSCC10B]) to test the effects e-liquid mixed at a 30/70 pg/vg ratio on cells and cancerous cells (likely to occur in ex-smokers). They exposed the experimental groups to vapor extract and marlboro red extract and compared this to the control group.
Neutral comet assay: tests tail length to find extent of DNA damage. DNA damage=potentially carcinogenic
Results: ranking from good to bad: control group-healthy cells, no nic e-liquid, nicotine alone, nic+e-liquid (no test group for cigarettes). nic+e-liquid caused up to 1.5x damage when compared to the control group.
H2AX immunostaining: tests amount of DNA double strand breaks (DSB) important because: DSB=potentially carcinogenic
Results: both e-liquids caused DSB's in HaCat cells (1.5x for no nicotine e-liquids and 3x for nicotine e-liquids) and HSNCC lines. They downplay the severity of cigarette smoke but it caused the most amount of DSB's. Best to worst: control, no-nic e-liquids, nic+e-liq/nicotine, cigarettes
Cell cycle analysis (flow cytochemistry): DNA content is analyzed to see if cell cycle is normal/ cells are undergoing normal growth. Cells were treated with e-cig vapor extract for 1 week.
Results: there was a significant increase in cell death during the G1 phase for UMSCC10B and G2 phase for HN30 cells (cancerous cells) unrelated to nicotine content in juices. Put simply, cell's have a hard time growing and reproducing (separating)
Trypin blue: counts cells to see if there are cells dying or if it's not reproducing as much as normal
Results: compared to normal cell proliferation conditions, there was a 5x increase in cell death for non-nicotine juices and a 10x increase in cell death for nicotine juices. Looking at their pictures, cigarettes/nicotine looks just as bad as nicotine e-liquid if not worse but it's just pictures, no way of telling for certain until I can get a cell count.
clonogenic assay: treating HNSCC cells to see if they can survive
Results: increase in cell death ranked best to worst: control healthy cells, no nicotine e-liquid, nicotine e-liquid, cigarette, nicotine.
Apoptotic Assay (annexin v): tests to see the stages/method of cell death. There are two forms, apoptosis which is normal programmed cell death/suicide, and necrosis which is like dropping a balloon in acid and having it dissolve the cell wall and kill the cell (unnatural).
Results: In HaCat (non-cancerous) testing, cells treated with e-liquid experienced an increase in cell apoptosis (suicide) and necrosis (death and disassociation like being blown up). Cigarettes tended to put cells into late apoptosis (induced suicide) whereas e-liquid had more live cells but still had more cells in apoptosis and necrosis than control. The numbers for this test are a little all over the place and not really in line with expected values (in my opinion) so I would disregard this test or take it with a grain of salt Basically, healthy cells die less, e-liquid causes more cell death through necrosis and apoptosis, and cigarettes causes a large amount to go through apoptosis (natural/programmed cell death) but not a lot to go through necrosis (90% of the cells are going through apoptosis, there aren't any cells left to go through necrosis)
ELI5: This study says vaping causes lung and throat cell death and can possibly be carcinogenic (breaks DNA strands). It still show's that vaping is much better than smoking marlboro red's. No smoke is better than any smoke but vaping is better than smoking. More study is needed to see how this affects us and our lungs in vitra.
Edit: everything's posted, I'll proofread later and make sure everything's as right as I can get it. Normally i'm the one laughing at these joke studies but from first glance, this seems to be an extremely robust experiment from a trusted source. That being said, it is slightly biased in that it doesn't say just how harmful cigarettes are compared to vaping but it just tells us that there are risks to vaping. There may be errors (not an md), don't hesitate to message me for questions and whatnots.
Electronic cigarettes induce DNA strand breaks and cell death independently of nicotine in cell lines
Vicky Yua, Mehran Rahimya, Avinaash Korrapatia, Yinan Xuana, Angela E. Zoua, Aswini R. Krishnana, Tzuhan Tsuib, Joseph A. Aguilerac, Sunil Advanic, Laura E. Crotty Alexanderb, Kevin T. Brumunda, Jessica Wang-Rodrigueze, Weg M. Ongkekoa.
Highlights
• Normal and HNSCC cell lines were cultured in e-cigarette vapor pulled through media.
• Cell cultures exposed to e-cigarette vapor show increased DNA double strand breaks.
• E-cigarette vapor induces increased cell death as compared to control.
• E-cigarette vapor decreases clonogenic survival as compared to control.
Objectives
Evaluate the cytotoxicity and genotoxicity of short- and long-term e-cigarette vapor exposure on a panel of normal epithelial and head and neck squamous cell carcinoma (HNSCC) cell lines.
Materials and methods
HaCaT, UMSCC10B, and HN30 were treated with nicotine-containing and nicotine-free vapor extract from two popular e-cigarette brands for periods ranging from 48 h to 8 weeks. Cytotoxicity was assessed using Annexin V flow cytometric analysis, trypan blue exclusion, and clonogenic assays. Genotoxicity in the form of DNA strand breaks was quantified using the neutral comet assay and γ-H2AX immunostaining.
Results
E-cigarette-exposed cells showed significantly reduced cell viability and clonogenic survival, along with increased rates of apoptosis and necrosis, regardless of e-cigarette vapor nicotine content. They also exhibited significantly increased comet tail length and accumulation of γ-H2AX foci, demonstrating increased DNA strand breaks.
Conclusion
E-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent. Further assessment of the potential carcinogenic effects of e-cigarette vapor is urgently needed.
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