愛(ài)默力大學(xué) (Emory University)Winship研究所的科學(xué)家,，發(fā)現(xiàn)了一個(gè)新的腦部生物標(biāo)記分子 (biomarker)，據(jù)初步的分析結(jié)果顯示,，科學(xué)家懷疑這個(gè)分子的出現(xiàn),，不但和腫瘤的惡性轉(zhuǎn)移有關(guān)，還很可能跟治療后腫瘤復(fù)發(fā)的機(jī)制,，有直接的關(guān)系,。
據(jù)發(fā)表在最新一期臨床癌癥研究 (Clinical Cancer Research)的這篇論文顯示,，這次研究人員深入的分析了罹患星狀細(xì)胞瘤 (Astrocytoma)和神經(jīng)膠質(zhì)瘤(glioma) 這類腦部惡性腫瘤患者的腦脊液(cerebro spinal fluid) ，結(jié)果發(fā)現(xiàn)原本用以儲(chǔ)存腦部組織,，不會(huì)出現(xiàn)腫瘤細(xì)胞的腦脊液,，出現(xiàn)了一個(gè)稱為水溶性attractin(soluble attractin) 的蛋白質(zhì)。
這個(gè)由 Erwin Van Meir博士所主導(dǎo)的研究小組,，利用60 份來(lái)自不同時(shí)期腦部腫瘤患者的腦脊液,，透過(guò)蛋白質(zhì)體的研究方法，比對(duì)100 份健康個(gè)體的腦脊液,，結(jié)果居然發(fā)現(xiàn)97% 罹患惡性星狀細(xì)胞瘤(Astrocytoma)的患者,，腦脊液中存在著濃度較高的 attractin蛋白，而對(duì)于像是第四期惡性星狀細(xì)胞瘤的患者而言,，這個(gè)指標(biāo)分子的濃度,，更是高的驚人。
此外研究人員還認(rèn)為,，這個(gè) attractin蛋白很可能是由癌細(xì)胞自己所分泌,，因此腫瘤一旦轉(zhuǎn)移 attractin 蛋白濃度也跟著變化，參與計(jì)劃的科學(xué)家表示,，目前臨床上針對(duì)腦部腫瘤的患者,，極度缺乏非侵入式診斷與追蹤病情變化的工具，如今 attractin蛋白的出現(xiàn),，很可能在未來(lái)提供一個(gè)又快速又準(zhǔn)確的診斷與追蹤癌細(xì)胞的方法,。
英文原文：
Newly identified biomarker detects and regulates spread of brain tumors
ATLANTA -- Researchers at Emory University's Winship Cancer Institute have identified a novel biomarker for brain tumors and have uncovered a potential role the marker may play when the tumor spreads or comes back after treatment. The study, 褹ttractin is elevated in the cerebrospinal fluid of patients with malignant astrocytoma and mediates glioma cell migration," is published in the November issue of Clinical Cancer Research.
The biomarker, a protein known as "soluble attractin," is normally absent in the central nervous system (CNS) and is undetectable in cerebral spinal fluid (CSF), unless malignant astrocytomas--the most common form of intracranial tumors--are present in the CNS. The CSF is a liquid that bathes the brain and acts as a reservoir, which can be sampled for analysis of proteins secreted by CNS tumors.
This newfound ability to reliably identify biomarkers for malignant astrocytomas means that physicians will have a new minimally invasive method to track the success of treatments. These biomarkers, singly or in combination, will provide a fingerprint of the disease and be able in the future to better define the disease, predict what kind of treatment to use and allow doctors to monitor how well the tumor responds to treatment.
"Using proteomic analyses of the CSF of patients with brain tumors, we have identified for the first time that attractin levels are elevated in patients with high-grade astrocytoma," says Erwin Van Meir, PhD, professor of neurosurgery and hematology/oncology and lead author of the study. "Because few noninvasive methods are available for monitoring CNS malignancies, there is an urgent need to find reliable indicators."
Van Meir and his colleagues analyzed 60 cerebrospinal fluid or cyst fluid samples from patients with various CNS diseases using proteomics to examine simultaneously all proteins in biological samples. To validate the study's results, attractin levels in a set of 100 normal and tumoral brain samples also were examined. The researchers found elevated attractin levels in 97 percent of malignant astrocytomas, with the highest levels in grade IV tumors.
The grade of a tumor reflects the level of abnormality its cells exhibit and how quickly the tumor is likely to grow and spread and is a predictor of patient outcome. Low-grade tumors are slow growing and show little abnormality, whereas high-grade tumors are highly abnormal and grow and spread quickly, making treatment more difficult. Patients with highly malignant astrocytomas typically have a life expectancy of about one year even after neurosurgery, chemotherapy, and radiation therapy, highlighting the pressing need for more research to develop improved therapies.
Equally important, the researchers also found that attractin plays a key role in the motility of the cancer cells, which influences their ability to spread in the brain, a major cause of recurrence of malignant astrocytoma. Secreted by the tumors themselves, attractin induces cancer cells to migrate, although that mechanism is not well understood. Knowing that attractin modulates the migration and possibly the recurrence of these tumors makes it a promising target for future therapeutic intervention, says Dr. Van Meir. "Our studies suggest that measuring attractin levels in patients with grades II-IV astrocytoma should be explored further as a potential biomarker for monitoring the growth of these tumors or as a potential new target for therapy."
