注射细菌可杀灭癌细胞？

近日，在好莱坞举办的年度临床介入肿瘤学研讨会上，来自Anderson癌症研究中心的研究人员通过研究揭示了，利用细菌或许可以帮助治疗癌症。研究人员将一种名为诺维氏芽孢杆菌-NT（Clostridium novyi-NT）的细菌的孢子注射入6位患者机体的肿瘤中，随后细菌就可以在肿瘤中生长并且杀灭癌细胞。

诺维氏芽孢杆菌-NT生活在土壤中，其和引发食物中毒的芽孢杆菌非常相似，在将诺维氏芽孢杆菌-NT注射入癌症病人机体之前，研究人员首先通过移除该细菌的危险毒素来降低细菌的危险性；研究结果显示6位病人均存活下来了，但其中有一位病人在细菌注射后因一些非相关的原因发生了死亡。

研究者Ravi Murthy表示，当肿瘤生长达到一定尺寸后，其中一部分肿瘤组织就不再需要氧气了，其就会对常规的癌症疗法产生耐受性，比如对放疗和化疗产生耐受等；而诺维氏芽孢杆菌-NT则可以在无氧状态下生存从而在不影响正常组织的情况下破坏肿瘤细胞，同时该细菌也会诱发机体对癌症产生免疫反应。

从本质上来讲，诺维氏芽孢杆菌-NT在肿瘤组织中可以引发潜在的杀灭癌细胞的感染过程，本文研究对于后期开发新型的抗癌疗法提供了新的研究思路和依据。

原文： 

Researchers injected a weakened strain of Clostridium novyi-NT bacteria spores into tumors in six patients. The bacteria grew in the tumors and killed cancer cells, the investigators reported.

C. novyi-NT, which lives in soil, is a close relative of the bacteria that causes botulism. Before injecting C. novyi-NT into the patients, the researchers weakened it by removing its dangerous toxin.

Five of the six patients are still alive, while one died from unrelated causes several months after receiving the bacteria injection, according to the study to be presented Saturday at the annual Symposium on Clinical Interventional Oncology in Hollywood, Fla.

Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.

"When tumors reach a certain size, parts of them do not receive oxygen, which makes them resistant to conventional therapies such as radiation and chemotherapy," study author Dr. Ravi Murthy, a professor of interventional radiology at M.D. Anderson Cancer Center in Houston, said in a symposium news release.

"C. novyi-NT thrives under these conditions, hones in on the low-oxygen areas and destroys tumors from the inside while sparing normal tissue," Murthy explained.

C. novyi-NT also triggers an immune response to cancer.

"Essentially, C. novyi-NT causes a potent cancer-killing infection in the tumor," study principal investigator Dr. Filip Janku, an associate professor in the department of investigation therapeutics at M.D. Anderson Cancer Center, said in the news release.

The new findings are very preliminary and much additional research into the potential therapy is needed.