大麻提取物可阻斷腦瘤生長
http://www.www.srpcoatings.com
2004年8月18日
生物谷報道 日前西班牙科學家的一項新研究結果表明，一種大麻提取物有望使腦瘤和其他類型的腫瘤縮小。
在以前的研究中，科學家已經通過在老鼠身上的實驗證明，大麻中含有的一種活性物質可以對腦瘤有所改善。這一次西班牙Complutense大學的科學家準確地演示了這一生化過程，大麻提取物是通過阻斷腫瘤血管生成所需的一種關鍵化學物質來實現療效的。而且該研究小組首次通過人體實驗證明，在患有最具威脅性的腦瘤——多形性成膠質細胞瘤的病人身上，大麻提取物阻止了該化學物質的形成。雖然目前此項研究還只是處于初級階段，但是研究者認為這是一個好的開始：“大麻提取物阻止了血管生成，而一個腫瘤如果不能實現血管生成，它就不會再生長。要是我們一方面阻止其血管生成，另一方面想辦法殺死腫瘤細胞，我們就能找到治療癌癥的一種新方法。”
該研究小組在30只老鼠身上測試了delta-9-四氫大麻醇的效果。他們發(fā)現這種大麻提取物抑制了好幾種基因的表達，而這幾種基因與一種名為脈管內皮生長因子(VEGF)的化學物的生成有關，VEGF對于血管生成來說非常關鍵。大麻提取物顯著降低了老鼠體內VEGF的活性，在兩個人類腦瘤患者身上也顯示了同樣的效果。西班牙學者的研究表明，這種藥是通過提高一種名為神經酰胺的脂肪分子的活性來實現這一效果的。研究者說：“我們發(fā)現老鼠腦部的腫瘤變小了，還有一點蒼白。”腫瘤的蒼白表明其血供應缺乏，該藥物在人類患者身上也有同樣效果，不過“效果還是很初步的”。
, 百拇醫(yī)藥
英國研究腫瘤的醫(yī)學專家Richard Sullivan認為，這一研究為以腫瘤血供應為攻擊目標的抗癌藥物提供了一種重要的新的前驅化合物。他強調，因為目前其他科學家已經在研制一些VEGF抑制劑，對于大麻提取物就應該進行更詳細深入的研究。
相關研究成果刊登在8月115日的《腫瘤研究》雜志上。
ORIGINAL TEXT：
Marijuana ingredient inhibits VEGF pathway required for brain tumor blood vessels
Cannabinoids, the active ingredients in marijuana, restrict the sprouting of blood vessels to brain tumors by inhibiting the expression of genes needed for the production of vascular endothelial growth factor (VEGF).
, 百拇醫(yī)藥
According to a new study published in the August 15, 2004 issue of the journal Cancer Research, administration of cannabinoids significantly lowered VEGF activity in laboratory mice and two patients with late-stage glioblastoma.
"Blockade of the VEGF pathway constitutes one of the most promising antitumoral approaches currently available," said Manuel Guzmᮬ professor of biochemistry and molecular biology, with the Complutense University in Madrid, Spain, and the study's principal investigator.
, 百拇醫(yī)藥
"The present findings provide a novel pharmacological target for cannabinoid-based therapies."
Glioblastoma multiforme, the most aggressive form of glioma, strikes more than 7,000 Americans each year and is considered one of the most malignant and deadliest forms of cancer, generally resulting in death within one to two years following diagnosis.
The disease is usually treated with surgery, followed by conventional radiation alone or in combination with chemotherapy. However, the main tumor often evades total destruction, surviving and growing again, eventually killing the patient. For this reason, researchers are actively seeking other therapeutic strategies, some of which might be considered novel.
, 百拇醫(yī)藥
In this study, the investigators chose to work with cannabinoids which, in previous studies, have been shown to inhibit the growth of blood vessels, or angiogenesis, in laboratory mice. However, little was known about the specific mechanisms by which cannabinoids impair angiogenesis, or whether the chemical might do the same in human tumors.
To answer the first part of the question, the scientists induced gliomas in mice, which were subsequently inoculated with cannabinoids. Using DNA array analysis, the team examined 267 genes associated with the growth of blood vessels in tumors and found that cannabinoids lowered the expression of several genes related to the VEGF pathway, critical for angiogenesis.
, 百拇醫(yī)藥
The researchers also discovered that cannabinoids apparently worked by increasing the activity of ceramide, a lipid mediator of apoptosis, resulting in the functional inhibition of cells needed for VEGF production. The ability of cannabinoids to alter VEGF production was significantly stifled following the introduction of a ceramide inhibitor.
"As far as we know, this is the first report showing that ceramide depresses VEGF pathway by interfering with VEGF production," according to Guzmᮮ
, 百拇醫(yī)藥
To answer the second part of the question relating to clinical tests, the scientists obtained tumor biopsies from two patients with glioblastomas who had failed standard therapy, including surgery, radiotherapy and chemotherapy. The biopsied tissue was analyzed before and after local injection of a cannabinoid.
"In both patients, VEGF levels in tumor extracts were lower after cannabinoid inoculation," said Guzmᮮ
The results, he added, suggest a potential new approach toward the treatment of these otherwise intractable brain tumors.
, 百拇醫(yī)藥
"It is essential to develop new therapeutic strategies for the management of glioblastoma multiforme," the scientists wrote, "which will most likely require a combination of therapies to obtain significant clinical results."
Also participating in the study were Cristina Blằuez and Amador Haro, from Complutense University; Luis Gonzᬥz-Feria, from University Hospital, Tenerife, Spain; Luis ?varez, from La Paz University Hospital in Madrid; and M. Llanos Casanova, from the Project on Cellular and Molecular Biology and Gene Therapy, CIEMAT, also in Madrid.
, http://www.www.srpcoatings.com
###
Founded in 1907, the American Association for Cancer Research is a professional society of more than 22,000 laboratory, translational, and clinical scientists engaged in all areas of cancer research in the United States and in more than 60 countries. AACR's mission is to accelerate the prevention and cure of cancer through research, education, communication, and advocacy. Its principal activities include the publication of five major peer-reviewed scientific journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. AACR's Annual Meetings attract more than 15,000 participants who share new and significant discoveries in the cancer field. Specialty meetings, held throughout the year, focus on the latest developments in all areas of cancer research., 百拇醫(yī)藥
在以前的研究中，科學家已經通過在老鼠身上的實驗證明，大麻中含有的一種活性物質可以對腦瘤有所改善。這一次西班牙Complutense大學的科學家準確地演示了這一生化過程，大麻提取物是通過阻斷腫瘤血管生成所需的一種關鍵化學物質來實現療效的。而且該研究小組首次通過人體實驗證明，在患有最具威脅性的腦瘤——多形性成膠質細胞瘤的病人身上，大麻提取物阻止了該化學物質的形成。雖然目前此項研究還只是處于初級階段，但是研究者認為這是一個好的開始：“大麻提取物阻止了血管生成，而一個腫瘤如果不能實現血管生成，它就不會再生長。要是我們一方面阻止其血管生成，另一方面想辦法殺死腫瘤細胞，我們就能找到治療癌癥的一種新方法。”
該研究小組在30只老鼠身上測試了delta-9-四氫大麻醇的效果。他們發(fā)現這種大麻提取物抑制了好幾種基因的表達，而這幾種基因與一種名為脈管內皮生長因子(VEGF)的化學物的生成有關，VEGF對于血管生成來說非常關鍵。大麻提取物顯著降低了老鼠體內VEGF的活性，在兩個人類腦瘤患者身上也顯示了同樣的效果。西班牙學者的研究表明，這種藥是通過提高一種名為神經酰胺的脂肪分子的活性來實現這一效果的。研究者說：“我們發(fā)現老鼠腦部的腫瘤變小了，還有一點蒼白。”腫瘤的蒼白表明其血供應缺乏，該藥物在人類患者身上也有同樣效果，不過“效果還是很初步的”。
, 百拇醫(yī)藥
英國研究腫瘤的醫(yī)學專家Richard Sullivan認為，這一研究為以腫瘤血供應為攻擊目標的抗癌藥物提供了一種重要的新的前驅化合物。他強調，因為目前其他科學家已經在研制一些VEGF抑制劑，對于大麻提取物就應該進行更詳細深入的研究。
相關研究成果刊登在8月115日的《腫瘤研究》雜志上。
ORIGINAL TEXT：
Marijuana ingredient inhibits VEGF pathway required for brain tumor blood vessels
Cannabinoids, the active ingredients in marijuana, restrict the sprouting of blood vessels to brain tumors by inhibiting the expression of genes needed for the production of vascular endothelial growth factor (VEGF).
, 百拇醫(yī)藥
According to a new study published in the August 15, 2004 issue of the journal Cancer Research, administration of cannabinoids significantly lowered VEGF activity in laboratory mice and two patients with late-stage glioblastoma.
"Blockade of the VEGF pathway constitutes one of the most promising antitumoral approaches currently available," said Manuel Guzmᮬ professor of biochemistry and molecular biology, with the Complutense University in Madrid, Spain, and the study's principal investigator.
, 百拇醫(yī)藥
"The present findings provide a novel pharmacological target for cannabinoid-based therapies."
Glioblastoma multiforme, the most aggressive form of glioma, strikes more than 7,000 Americans each year and is considered one of the most malignant and deadliest forms of cancer, generally resulting in death within one to two years following diagnosis.
The disease is usually treated with surgery, followed by conventional radiation alone or in combination with chemotherapy. However, the main tumor often evades total destruction, surviving and growing again, eventually killing the patient. For this reason, researchers are actively seeking other therapeutic strategies, some of which might be considered novel.
, 百拇醫(yī)藥
In this study, the investigators chose to work with cannabinoids which, in previous studies, have been shown to inhibit the growth of blood vessels, or angiogenesis, in laboratory mice. However, little was known about the specific mechanisms by which cannabinoids impair angiogenesis, or whether the chemical might do the same in human tumors.
To answer the first part of the question, the scientists induced gliomas in mice, which were subsequently inoculated with cannabinoids. Using DNA array analysis, the team examined 267 genes associated with the growth of blood vessels in tumors and found that cannabinoids lowered the expression of several genes related to the VEGF pathway, critical for angiogenesis.
, 百拇醫(yī)藥
The researchers also discovered that cannabinoids apparently worked by increasing the activity of ceramide, a lipid mediator of apoptosis, resulting in the functional inhibition of cells needed for VEGF production. The ability of cannabinoids to alter VEGF production was significantly stifled following the introduction of a ceramide inhibitor.
"As far as we know, this is the first report showing that ceramide depresses VEGF pathway by interfering with VEGF production," according to Guzmᮮ
, 百拇醫(yī)藥
To answer the second part of the question relating to clinical tests, the scientists obtained tumor biopsies from two patients with glioblastomas who had failed standard therapy, including surgery, radiotherapy and chemotherapy. The biopsied tissue was analyzed before and after local injection of a cannabinoid.
"In both patients, VEGF levels in tumor extracts were lower after cannabinoid inoculation," said Guzmᮮ
The results, he added, suggest a potential new approach toward the treatment of these otherwise intractable brain tumors.
, 百拇醫(yī)藥
"It is essential to develop new therapeutic strategies for the management of glioblastoma multiforme," the scientists wrote, "which will most likely require a combination of therapies to obtain significant clinical results."
Also participating in the study were Cristina Blằuez and Amador Haro, from Complutense University; Luis Gonzᬥz-Feria, from University Hospital, Tenerife, Spain; Luis ?varez, from La Paz University Hospital in Madrid; and M. Llanos Casanova, from the Project on Cellular and Molecular Biology and Gene Therapy, CIEMAT, also in Madrid.
, http://www.www.srpcoatings.com
###
Founded in 1907, the American Association for Cancer Research is a professional society of more than 22,000 laboratory, translational, and clinical scientists engaged in all areas of cancer research in the United States and in more than 60 countries. AACR's mission is to accelerate the prevention and cure of cancer through research, education, communication, and advocacy. Its principal activities include the publication of five major peer-reviewed scientific journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. AACR's Annual Meetings attract more than 15,000 participants who share new and significant discoveries in the cancer field. Specialty meetings, held throughout the year, focus on the latest developments in all areas of cancer research., 百拇醫(yī)藥