美国麻省总医院发明分离血液中肿瘤细胞的方法

2014/10/9 9:52:07 本站原创 佚名 【字体:

 

美国麻省总医院发明分离血液中肿瘤细胞的方法
 
和传统的技术不同,他们研发的CTC-iChip不用依赖肿瘤细胞的表明标志。他们通过去除血液样本中血细胞、留下循环肿瘤细胞的原理,可实现对几乎所有类型癌症的循环肿瘤细胞的检测。CTC-iChip同样基于免疫磁珠技术,但其目标不是以往技术中的癌细胞本身,而是血液中的免疫细胞。CTC-iChip首先利用覆盖有可识别免疫细胞表面蛋白的磁珠对白细胞进行标记,血液样本然后流经微流体腔室,根据体积大小将红细胞、血浆以及剩余的磁珠进行洗脱,剩余物随后通过磁场将结合磁珠的白细胞弃去,留下CTC。
 
New Technology Isolates Tumor Cells from Blood to Optimize Cancer Therapy 
 
A team of bioengineers, molecular biologists, and clinicians used a novel rare cell-sorter to isolate breast cancer cells from the blood of patients, with the aim of identifying the most effective drugs to treat each individual tumor. Circulating tumor cells (CTCs) were isolated and grown in the laboratory for extensive genetic analysis, which enabled the identification and testing of the most effective cancer-killing drugs for those tumors. The ability to perform such genetic analysis in the laboratory paves the way for providing the most effective treatment, not only initially, but throughout the course of the disease, as mutating tumors become resistant to certain drugs, but susceptible to others.
 
Led by senior authors Daniel Haber, MD, PhD, and Shyamala Maheswaran, PhD, of Massachusetts General Hospital Cancer Center at Harvard Medical School; and Mehmet Toner, PhD, Harvard Center for Bioengineering in Medicine, the research team, who developed a microfluidic chip called the CTC-iChip, used it to isolate the minute numbers of tumor cells circulating in the blood. The work is reported in the July 11 issue of Science. 
 
The CTC-iChip is unique in that it does not use cancer cell markers on the surface of the CTCs to identify cells for capture. This is important because these markers change as the cancer progresses, so that captured cells obtained by using such markers may only represent a subset of cells shed by the tumor. Instead the iChip efficiently removes the normal blood cells, leaving behind viable CTCs that represent cells shed from both the primary tumor as well as metastatic tumor deposits – tumor nodules arising in distant organs due to the deposition of CTCs. 
 
The other key advance in the study was the development of a cell culture system that allowed the CTCs to successfully grow in the laboratory. The expansion of the CTCs in cell culture is critical for having enough cells for genetic analysis and subsequent testing of anti-cancer drugs and drug combinations that target the newly evolved mutations. After much trial and error the group found that the cells could be successfully grown and expanded when cultured as suspended spheres of cells rather than when attached as a monolayer to the bottom of the cell culture plate. Importantly, with this new culture technique, the cells did not mutate over time while in culture -- a common problem when growing cells in the laboratory.
 
The researchers used the iChip to isolate CTCs from the blood of 36 breast cancer patients. Cell lines were successfully established from the CTCs of six of these patients. Genetic analysis of the cell lines were compared with biopsies from the parent tumor to determine whether the metastatic tumors had evolved over time. Cultures derived from the same patient at multiple time points were compared to verify that culture conditions did not result in genetic changes in the CTCs. Standard care at Massachusetts General Hospital involves screening for a variety of mutations in just 25 genes. In contrast, the CTC cell lines enabled a far more extensive mutational analysis, including screening for mutations in 1,000 cancer genes. 
 
Armed with such a comprehensive genetic analysis, the researchers then tested CTC lines for sensitivity to panels of single medications and medication combinations, based on knowledge of the susceptibility of various cancer mutations to certain drugs. The aim of these experiments was to identify which medications worked best on the tumor cells of each individual patient. 
 
The test results indicated that tumors from several patients responded to therapy with medications commonly used for tumors carrying the mutations identified with the standard 25-gene analysis. However, several of the tumor samples did not respond to such treatments, but were responsive to different combinations of medications identified through the more extensive 1,000 gene screening made possible by isolation of the CTCs. Therefore, this proof of concept study successfully demonstrated that this approach has the potential to identify a wider range of genetic mutations, enabling treatments that successfully target the specific mutations in each patient’s tumor.
 
The work is a significant first step towards “precision medicine” in oncology where treatments are tailored to the drug sensitivity patterns in individual patients. Furthermore, the system offers the opportunity to adjust treatments throughout the course of disease based on evolving tumor mutation profiles. By repeated sampling of CTCs throughout the course of a patient’s disease, medications can be adjusted as individual tumors become resistant to certain medications but susceptible to others.
 
Source
Ex vivo culture of circulating breast tumor cells for individualized testing of drug susceptibility 
Min Yu, et al. Science 11 July 2014 345:216-220
 
 
和传统的技术不同,他们研发的CTC-iChip不用依赖肿瘤细胞的表明标志。他们通过去除血液样本中血细胞、留下循环肿瘤细胞的原理,可实现对几乎所有类型癌症的循环肿瘤细胞的检测。CTC-iChip同样基于免疫磁珠技术,但其目标不是以往技术中的癌细胞本身,而是血液中的免疫细胞。CTC-iChip首先利用覆盖有可识别免疫细胞表面蛋白的磁珠对白细胞进行标记,血液样本然后流经微流体腔室,根据体积大小将红细胞、血浆以及剩余的磁珠进行洗脱,剩余物随后通过磁场将结合磁珠的白细胞弃去,留下CTC。
 
New Technology Isolates Tumor Cells from Blood to Optimize Cancer Therapy 
 
A team of bioengineers, molecular biologists, and clinicians used a novel rare cell-sorter to isolate breast cancer cells from the blood of patients, with the aim of identifying the most effective drugs to treat each individual tumor. Circulating tumor cells (CTCs) were isolated and grown in the laboratory for extensive genetic analysis, which enabled the identification and testing of the most effective cancer-killing drugs for those tumors. The ability to perform such genetic analysis in the laboratory paves the way for providing the most effective treatment, not only initially, but throughout the course of the disease, as mutating tumors become resistant to certain drugs, but susceptible to others.
 
Led by senior authors Daniel Haber, MD, PhD, and Shyamala Maheswaran, PhD, of Massachusetts General Hospital Cancer Center at Harvard Medical School; and Mehmet Toner, PhD, Harvard Center for Bioengineering in Medicine, the research team, who developed a microfluidic chip called the CTC-iChip, used it to isolate the minute numbers of tumor cells circulating in the blood. The work is reported in the July 11 issue of Science. 
 
The CTC-iChip is unique in that it does not use cancer cell markers on the surface of the CTCs to identify cells for capture. This is important because these markers change as the cancer progresses, so that captured cells obtained by using such markers may only represent a subset of cells shed by the tumor. Instead the iChip efficiently removes the normal blood cells, leaving behind viable CTCs that represent cells shed from both the primary tumor as well as metastatic tumor deposits – tumor nodules arising in distant organs due to the deposition of CTCs. 
 
The other key advance in the study was the development of a cell culture system that allowed the CTCs to successfully grow in the laboratory. The expansion of the CTCs in cell culture is critical for having enough cells for genetic analysis and subsequent testing of anti-cancer drugs and drug combinations that target the newly evolved mutations. After much trial and error the group found that the cells could be successfully grown and expanded when cultured as suspended spheres of cells rather than when attached as a monolayer to the bottom of the cell culture plate. Importantly, with this new culture technique, the cells did not mutate over time while in culture -- a common problem when growing cells in the laboratory.
 
The researchers used the iChip to isolate CTCs from the blood of 36 breast cancer patients. Cell lines were successfully established from the CTCs of six of these patients. Genetic analysis of the cell lines were compared with biopsies from the parent tumor to determine whether the metastatic tumors had evolved over time. Cultures derived from the same patient at multiple time points were compared to verify that culture conditions did not result in genetic changes in the CTCs. Standard care at Massachusetts General Hospital involves screening for a variety of mutations in just 25 genes. In contrast, the CTC cell lines enabled a far more extensive mutational analysis, including screening for mutations in 1,000 cancer genes. 
 
Armed with such a comprehensive genetic analysis, the researchers then tested CTC lines for sensitivity to panels of single medications and medication combinations, based on knowledge of the susceptibility of various cancer mutations to certain drugs. The aim of these experiments was to identify which medications worked best on the tumor cells of each individual patient. 
 
The test results indicated that tumors from several patients responded to therapy with medications commonly used for tumors carrying the mutations identified with the standard 25-gene analysis. However, several of the tumor samples did not respond to such treatments, but were responsive to different combinations of medications identified through the more extensive 1,000 gene screening made possible by isolation of the CTCs. Therefore, this proof of concept study successfully demonstrated that this approach has the potential to identify a wider range of genetic mutations, enabling treatments that successfully target the specific mutations in each patient’s tumor.
 
The work is a significant first step towards “precision medicine” in oncology where treatments are tailored to the drug sensitivity patterns in individual patients. Furthermore, the system offers the opportunity to adjust treatments throughout the course of disease based on evolving tumor mutation profiles. By repeated sampling of CTCs throughout the course of a patient’s disease, medications can be adjusted as individual tumors become resistant to certain medications but susceptible to others.
 
Source
Ex vivo culture of circulating breast tumor cells for individualized testing of drug susceptibility 
Min Yu, et al. Science 11 July 2014 345:216-220
 

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