大麻提取物对脑瘤有惊人影响

最近，有专家表明，当大麻的某些成分用来与放疗并肩作战治疗高级别脑胶质瘤时，肿瘤的增长几乎消失。相关研究结果已经发表在最近的《Molecular Cancer Therapeutics》杂志。

　　

生物通报道：脑胶质瘤（脑胶质细胞瘤）约占颅内肿瘤的46%。世界卫生组织1998年公布按死亡率顺序排位，恶性胶质瘤是34岁以下肿瘤患者的第2位死亡原因，是35～54岁患者的第3位死亡原因。胶质细胞瘤偏良性者生长缓慢，病程较长，自出现症状至就诊时间平均两年，恶性者瘤体生长快，病程短，自出现症状到就诊时多数在3个月之内，70%～80%多在半年之内。

最近，有专家表明，当大麻的某些成分用来与放疗并肩作战治疗高级别脑胶质瘤时，肿瘤的增长几乎消失。

这项新研究是由圣乔治伦敦大学的专家进行的，他们在实验室研究了脑癌肿瘤的治疗，发现大多数有效的治疗方法都是，联合使用大麻植物的活性化学成分，称为大麻素（cannabinoids）。

作为该研究的一部分，研究人员检测了其中两种化合物，称为四氢大麻酚（THC）和大麻二酚（CBD）。高级别脑胶质瘤很难治疗，每年夺去大约5200人的生命。这种疾病的预后也较差，患者的五年生存率大约是10%。

大麻素是大麻中的活性物质，更具体地说也被称为phytocannabinoids。在大麻植物中有85种已知的大麻素。大麻作用于精神的主要成分是THC。

这项新研究首次表明，当THC和CBD与放疗联合使用时，会表现出一种剧烈的效果。当THC/CBD与放疗一起使用时，小鼠大脑中的肿瘤生长戏剧性地放缓。

本文资深作者、本项目首席研究员Wai Liu博士说：“结果是非常令人兴奋的。我们用各种不同的方式治疗肿瘤，要么不治疗，要么只用大麻素，要么只用放疗，要么同时使用大麻素和放疗。”

“用放疗和大麻素联合治疗，获得了最有益的结果，并且肿瘤大幅减小。在某些情况下，动物体内的肿瘤有效地消失。这预示着未来可在人类当中进行进一步研究。高级别脑胶质瘤是目前最致命的一种疾病。”

“大麻植物成分的好处在这之前已为人所知，但是与放疗一起使用，使脑瘤急剧减少，是一种新鲜的事物，对处于严重状况的脑瘤患者来说，这将是非常有前景的。”

该研究小组目前正在讨论将大麻素联合放疗用于人类临床试验的可能性。相关研究结果已经发表在最近的《Molecular Cancer Therapeutics》杂志。

（生物通：王英）

延伸阅读：Stem Cells：用毒素分泌干细胞来治疗脑瘤

生物通推荐原文摘要：
The Combination of Cannabidiol and Δ9-Tetrahydrocannabinol Enhances the Anticancer Effects of Radiation in an Orthotopic Murine Glioma Model
Abstract：High-grade glioma is one of the most aggressive cancers in adult humans and long-term survival rates are very low as standard treatments for glioma remain largely unsuccessful. Cannabinoids have been shown to specifically inhibit glioma growth as well as neutralize oncogenic processes such as angiogenesis. In an attempt to improve treatment outcome, we have investigated the effect of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) both alone and in combination with radiotherapy in a number of glioma cell lines (T98G, U87MG, and GL261). Cannabinoids were used in two forms, pure (P) and as a botanical drug substance (BDS). Results demonstrated a duration- and dose-dependent reduction in cell viability with each cannabinoid and suggested that THC-BDS was more efficacious than THC-P, whereas, conversely, CBD-P was more efficacious than CBD-BDS. Median effect analysis revealed all combinations to be hyperadditive [T98G 48-hour combination index (CI) at FU50, 0.77–1.09]. Similarly, pretreating cells with THC-P and CBD-P together for 4 hours before irradiation increased their radiosensitivity when compared with pretreating with either of the cannabinoids individually. The increase in radiosensitivity was associated with an increase in markers of autophagy and apoptosis. These in vitro results were recapitulated in an orthotopic murine model for glioma, which showed dramatic reductions in tumor volumes when both cannabinoids were used with irradiation (day 21: 5.5 ± 2.2 mm3 vs. 48.7 ± 24.9 mm3 in the control group; P < 0.01). Taken together, our data highlight the possibility that these cannabinoids can prime glioma cells to respond better to ionizing radiation, and suggest a potential clinical benefit for glioma patients by using these two treatment modalities.