cannabisnews.com: Study Finds MJ Ingredient Promotes Tumor Growth Study Finds MJ Ingredient Promotes Tumor Growth Posted by FoM on June 20, 2000 at 11:52:48 PT NIH-National Institute on Drug Abuse Source: Eureka Alert Researchers report in the July 2000 issue of the Journal of Immunology that tetrahydrocannabinol (THC), the major psychoactive component of marijuana, can promote tumor growth by impairing the body's anti-tumor immunity system. While previous research has shown that THC can lower resistance to both bacterial and viral infections, this is the first time that its possible tumor-promoting activity has been reported. A team of researchers at UCLA's Jonsson Cancer Center found in experiments in mice that THC limits immune response by increasing the availability of two forms (IL-10 and TGF-beta) of cytokine, a potent, tumor-specific, immunity suppresser. The authors also suggest that smoking marijuana may be more of a cancer risk than smoking tobacco. The tar portion of marijuana smoke, compared to that of tobacco, contains higher concentrations of carcinogenic hydrocarbons, including benzapyrene, a key factor in promoting human lung cancer. And marijuana smoke deposits four times as much tar in the respiratory tract as does a comparable amount of tobacco, thus increasing exposure to carcinogens. Dr. Steven M. Dubinett, head of the research team that conducted the study, says, "What we already know about marijuana smoke, coupled with our new finding that THC may encourage tumor growth, suggests that regular use of marijuana may increase the risk of respiratory tract cancer and further studies will be needed to evaluate this possibility." The UCLA researchers examined the effects of THC on the immune response to lung cancer in mice. Over a two-week period, the animals were injected four times per week with either THC or a saline solution. Fourteen days after the injections were started, murine Lewis lung cancer and line 1 alveolar cell cancer cells were implanted in the mice. The mice continued to receive THC or saline injections after the tumor cells were implanted, and tumor growth was assessed three times each week. To test the hypothesis that THC impairs tumor-specific immune system response, a group of mice with compromised immune systems was also studied. The researchers found that in the mice with normal immune systems there was significant enhancement of tumor growth, but THC had no effect on tumor growth in the immunodeficient mice. The study also showed that when lymphocytes from the THC-treated mice were injected into untreated mice, the immune deficit was transferred and tumor growth was accelerated in the normal controls. Additionally, the UCLA research team demonstrated that when anti-IL-10 and anti-TGF-beta were administered, there was no acceleration of tumor growth in THC-treated mice. These results suggest that enhanced tumor growth is prompted by THC's ability to stimulate production of IL-10 and TGF-beta, which inhibits anti-tumor immune response. The National Institute on Drug Abuse is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports more than 85 percent of the world's research on the health aspects of drug abuse and addiction. The Institute carries out a large variety of programs to ensure the rapid dissemination of research information and its implementation in policy and practice. Fact sheets on the health effects of drugs of abuse and other topics can be ordered free of charge in English and Spanish by calling NIDA Infofax at 1-888-NIH-NIDA (644-6432) or 1-888-TTY-NIDA (889-6432) for the deaf. These fact sheets and further information on NIDA research and other activities can be found on the NIDA home page at: http://www.drugabuse.gov. (thcrelease) NIH-National Institute on Drug Abuse http://www.nida.nih.gov/NIDAHome1.htmlEmbargoed For Release: June 20, 2000Contact: Michelle MuthE-Mail: mm488g nih.gov301-594-6141Copyright © 2000 EurekAlertRelated Articles & Web Site:Jonsson Cancer Centerhttp://www.cancer.mednet.ucla.edu/Marijuana Helps Tumours Growhttp://cannabisnews.com/news/thread6113.shtmlPot Shrinks Tumors: Government Knew in 74http://cannabisnews.com/news/thread5972.shtmlNew Class Of Chemicals Found To Use Marijuanahttp://cannabisnews.com/news/thread5602.shtmlMarijuana Ingredient Kills Rat Brain Tumors http://cannabisnews.com/news/thread4900.shtmlMarijuana Ingredient May Fight Brain Cancerhttp://cannabisnews.com/news/thread4890.shtmlMarijuana Patch Research For Cancer Patients http://cannabisnews.com/news/thread4385.shtmlResearchers Link Marijuana To Cancerhttp://cannabisnews.com/news/thread4267.shtmlCannabisNews Medical Marijuana Archives:http://cannabisnews.com/news/list/medical.shtml Home Comment Email Register Recent Comments Help Comment #16 posted by Joe in the Know on July 15, 2001 at 18:43:26 PT: canabis NIDA is so wrong. Ralph Waldo Emerson wrote: Beat nature back with a knife and nature will come back at you with a fork. What ever you do to try and sell people on something other than the truth about canabis will come back on you big time. NIDA is goverment funded and has a agenda to publish information that will keep there funding. The truth about canabis is that the worst thing about smoking it is the smoke itself. Vaporize and be wise. When it cost more than gold per ounce why burn any of it. [ Post Comment ] Comment #15 posted by Jade on April 03, 2001 at 16:17:27 PT: Calling all Pot Heads If you think it isn't addictive then stop using it for about a year. Only an addict would be so upset about being told to stop. [ Post Comment ] Comment #14 posted by Eric Draven on February 21, 2001 at 10:01:38 PT: why cant u people just get along and hit a bong? marijauna,pot,whatever you people want to call it,its ok to smoke pot as long as people keep there cool.you must agree there are a lot more harmful than marijauna.i dont understand why everyone is cracking down on marijauna,if it were legal than no one would have any problems with pot smokers,the marijauna is told,and as i have found out,has a mellowing effect.so all be cool and go schmoke a boowl. http://mcesc.com [ Post Comment ] Comment #13 posted by Dan Hillman on June 22, 2000 at 13:43:40 PT Tell PETA dddd: We start with the figure from the paper: 5mg/kg of THC administered to mice 4 times/week.I weigh 90 kg (about 200 lbs). 90kg x 5mg/kg = 450 mg450 mg is almost a half gram of pure THC.Let's say I've got pot that's very good and has a THC level of %10. If *all* of the THC of the pot I used went into my bloodstream (unlikely), I would need to consume about 50 grams of pot 4 times a week to duplicate the exposure given to these mice. I.e. between 1/3 and 1/2 a pound a week...of course, if only 20% of the THC went into my bloodstream ( a more realistic estimate with regards to smoking/vaporizing ) I would need to consume upwards of 2-3 lbs. of cannabis a week to duplicate the ingestion rate of the mice in the study. Cruelty to animals, ahoy! [ Post Comment ] Comment #12 posted by dddd on June 22, 2000 at 01:27:06 PT human/mouse Hey Dave in Florida.Would it be possible for you somehow look at this data you posted,and extrapolate and approximate,the equivelent/ratio,of the amounts these mice were tested with,and how much that would be to a human?Just a ballpark guess would be cool............dddd [ Post Comment ] Comment #11 posted by Dave in Florida on June 21, 2000 at 19:45:33 PT Barry's Payola never Ends Here is the abstract and the link to this study.http://www.jimmunol.org/v165n1/>-9-T etrahydrocannabinol Inhibits Antitumor Immunity by a CB2 Receptor-Mediated, Cytokine-Dependent Pathway1 Li X. Zhu,*† Sherven Sharma,*†‡ Marina Stolina,* Brian Gardner,*† Michael D. Roth,† Donald P. Tashkin,† and Steven M. Dubinett2*†‡ *Pulmonary Immunology Laboratory and †Division of Pulmonary and Critical Care Medicine, University of California, Los Angeles, School of Medicine, Los Angeles, CA 90095; and ‡Veterans Affairs West Los Angeles Healthcare Center, Los Angeles, CA 90073 The Journal of Immunology, 2000, 165: 373-380.In this study, we show that -9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, suppresses host immune reactivity against lung cancer. In two different weakly immunogenic murine lung cancer models, intermittentadministration of THC (5 mg/kg, four times/wk i.p. for 4 wk) led to accelerated growth of tumor implants compared withtreatment with diluent alone. In contrast to our findings in immunocompetent mice, THC did not affect tumor growth intumor-bearing SCID mice. The immune inhibitory cytokines, IL-10 and TGF-, were augmented, while IFN- wasdown-regulated at both the tumor site and in the spleens of THC-treated mice. Administration of either anti-IL-10- oranti-TGF--neutralizing Abs prevented the THC-induced enhancement in tumor growth. Both APC and T cells fromTHC-treated mice showed limited capacities to generate alloreactivity. Furthermore, lymphocytes from THC-treated mice transferred the effect to normal mice, resulting in accelerated tumor growth similar to that seen in the THC-treated mice. THC decreased tumor immunogenicity, as indicated by the limited capacity for tumor-immunized, THC-treated mice to withstand tumor rechallenge. In vivo administration of a specific antagonist of the CB2 cannabinoid receptor also blocked the effects of THC. Our findings suggest the THC promotes tumor growth by inhibiting antitumor immunity by a CB2 receptor-mediated, cytokine-dependent pathway. Here is another abstract that says somthing different from the previous issue http://www.jimmunol.org/v164n12/9-Tetrahydrocannabinol Treatment Suppresses Immunity and Early IFN-, IL-12, and IL-12 Receptor 2 Responses to Legionella pneumophila Infection1 Thomas W. Klein,2 Catherine A. Newton, Noryia Nakachi, and Herman Friedman Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa, FL 33612 The Journal of Immunology, 2000, 164: 6461-6466.The marijuana cannabinoid, 9-tetrahydrocannabinol (THC), suppresses immunity to Legionella pneumophila anddevelopment of Th1 activity and cell-mediated immunity. In the current study, THC effects on cytokines regulating thedevelopment of Th1 cells were examined. BALB/c mice showed significant increases in serum IL-12 and IFN- within hoursof infection; however, the levels of these Th1-promoting cytokines as well as resistance to a challenge infection were suppressed by THC (8 mg/kg) injected 18 h before priming. The Th2-promoting cytokine, IL-4, was increased within hours of a Legionella infection and was further increased by THC treatment. These results suggested that THC injection suppressed the cytokine environment promoting Th1 immunity. In additional experiments, THC pretreatment and infection of IL-4 knockout mice showed that serum IL-12 and IFN- were suppressed equally in both knockout and normal mice. This suggested that the drug-induced increase in IL-4 was not responsible for the decreases in serum IL-12 and IFN-. However, THC treatment was shown to suppress the expression of IL-12 receptor 2 mRNA, indicating that, in addition to suppression of IL-12, THC injection suppressed the expression of IL-12 receptors. Finally, the role of cannabinoid receptors in Th1-promoting cytokine suppression was examined, and results with receptor antagonists showed that both cannabinoid receptors 1 and 2 were involved. It is suggested that suppression of Th1 immunity to Legionella is not due to an increase in IL-4 production but to a decrease in IFN- and IL-12. Furthermore, both types of cannabinoid receptors are involved. http://www.jimmunol.org/v164n12/6461/6461-abs-frame.html http://www.jimmunol.org/v165n1/373/373-abs-frame.html [ Post Comment ] Comment #10 posted by kaptinemo on June 21, 2000 at 13:59:52 PT: Yeah, and mother's milk causes cancer The goons at NIDA have given scientists a bad name for over 20 years. They were the office that practically demanded that any research institutes that had conducted cannabis studies prior to 1980 destroy their results; NIDA had the only 'scientifically valid' studies which 'proved' canabis's deadly effects.(We are the only true faith, and all others are heathens, pagans, the great unwashed, the squatters in darkness, kaffirs, etc. Our way is the only true way to enlightenment, yadda-yadda. The same thing less sophisticated but no less dangerous characters have been spouting for years. But it's especially ugly when a scientist makes such noises.)With Leshner at the helm of NIDA, don't expect any objectivity. He knows his future depends on mouthing the party line. [ Post Comment ] Comment #9 posted by Kanabys on June 21, 2000 at 12:34:24 PT HA HA When I read the first part of this article, I thought, "Oh No, not weed!!!!" Then I saw who put on the study and rolled on the floor laughing for 10 min.This is just like in the 70's when they pumped mice full of saccharin, thousands of times as much as a heavy pop drinker comsumes in a day, and claimed it caused cancer.Now they say "oops, we now found that saccharin is safe to use."The govt will never cease to amaze me in how they feel they can dupe the people. My only concern is that it does dupe way too many. [ Post Comment ] Comment #8 posted by Dan B on June 20, 2000 at 20:49:48 PT: More Research with Real People Suggets the Opposit I agree with Dan Hillman--if they did studies on human beings who use marijuana, the results would be quite different. Check out my comments for the other article; you'll find a link to a study which suggests a lowered risk for cancer in marijuana patients.Sheesh! These people will stop at nothing to warp the truth. Injecting mice with massive doses of THC means only one thing: they can't get the same result when they use doses comparable to normal human usage. [ Post Comment ] Comment #7 posted by Dan Hillman on June 20, 2000 at 17:34:38 PT It's all about grants. Dr. Steven M. Dubinett is just like anybody else walking the streets looking for a john. Who's gonna pay for what he puts out? Answer: the government will gladly pay for any study that "proves" that marijuana causes cancer. (Hmmm, didn't they used to say it turned you into a communist?) Hey, Steve, I'll bet you were up all night trying to think of a printable way to say "give me more money and I'll gladly find more proof that pot kills you." One thing he *won't* study, of course, is actual cannabis users. That would blow the whole game, wouldn't it Steve? And r.earing, I wholeheartedly agree. Wouldn't it be wonderful to see some REAL research done... [ Post Comment ] Comment #6 posted by dddd on June 20, 2000 at 16:09:11 PT CRAP! Give me a freekin' break! All of a sudden,it's breaking news,from the NIDA,that vermin,injected with massive amounts of THC,(synthetic?),was not good. How about if we OD these rats on Paxil,or Claritin,or Ritalin,in the equivelent massive overdoses.Do you think the NIDA would have a news release about it.disgusting.....dddd [ Post Comment ] Comment #5 posted by Freedom on June 20, 2000 at 13:56:10 PT Any time. My pleasure FoM, thank you for the NIDA propaganda. ;-) [ Post Comment ] Comment #4 posted by drfist on June 20, 2000 at 13:25:40 PT This study was with LEGAL THC not Cannabis Injecting synthetic THC marinol™ into mice has no relationship to normal proven harmless cannabis smoke and of course since "marijauna is 10 times stronger than in the 60's" you only need a tiny amount very litte risk from tars in the buds. forced to smoke ditch weed all day, maybe! [ Post Comment ] Comment #3 posted by FoM on June 20, 2000 at 13:08:31 PT Thanks Freedom Thanks Freedom! If another article comes up on this topic I will add the WEB M.D. link!Peace, FoM! [ Post Comment ] Comment #2 posted by Freedom on June 20, 2000 at 12:56:58 PT NIDA at work. Uy vey... I prefer that they would actually observe real users in the real world to go along with this... I have little doubt they pumped these poor mice with amounts of THC that were excessive. Of course, this will get wide play, while my posted link will get almost zero, and no one will ask just how much THC these mice were injected with.Those of us who observe, know exactly where NIDA is coming from.http://my.webmd.com/content/article/1728.57309 Marijuana Unlikely to Cause Head, Neck, or Lung Cancer Cancer Prevention Efforts Should Focus on Tobacco and Alcohol, Says Researcher By Peggy Peck WebMD Medical News May 8, 2000 (Boston) [ Post Comment ] Comment #1 posted by r.earing on June 20, 2000 at 12:14:57 PT: here's the problem Ok, let's assume that NIDA did fair, accurate research on this issue.Because of their record of lying about marijuana in the past,no one can take THIS study seriously.It's a shame that their credibility is so low.I for one would like to know,FOR REAL, whether cancer is a signifigant risk. [ Post Comment ] Post Comment Name: Optional Password: E-Mail: Subject: Comment: [Please refrain from using profanity in your message] Link URL: Link Title: