Microsatellite alterations plasma DNA of primary breast cancer patients.
Microsatellite alterations plasma DNA of primary breast cancer patients.
复制标题
微卫星改变原发性乳腺癌患者的血浆 DNA。
作者：
J. Shaw;B. Smith;T. Walsh;S. Johnson;L. Primrose;M. Slade;R. Walker;R. Coombes
本研究的目的是分析原发和转移性乳腺癌患者血浆DNA的肿瘤特异性改变，并将这些发现与免疫细胞化学和细胞角蛋白19(CK19)mRNA检测微转移的检测结果进行比较。从71例乳腺癌患者和9例正常对照的血浆、淋巴细胞和显微解剖肿瘤组织切片中提取DNA。用两个多态标记(DM-1和D16S400)对DNA样本进行杂合性缺失(LOH)和/或微卫星不稳定性(MI)分析。采用逆转录定量聚合酶链式反应(QPCR)和免疫细胞化学方法检测CK19mRNA和蛋白的表达。乳腺癌患者血浆DNA存在频繁的LOH(31.3%)和MI(11.6%)，显微解剖的肿瘤DNA也有相同的改变。最值得注意的是，39例乳腺癌患者中有10例出现LOH(n=6)或MI(n=4)。我们比较了32例原发癌患者的血浆肿瘤DNA、血浆和骨髓定量聚合酶链式反应以及血液和骨髓免疫细胞化学。在这些患者中，只有一名患者的血液中有免疫细胞化学检测到的癌细胞，三名患者的血浆CK19mRNA水平异常高。这四名患者都有血浆DNA变化。然后我们比较了骨髓的结果：在10例表现为杂合性缺失或心肌梗死的乳腺癌中，6例CK19基因表达升高，5例免疫细胞化学阳性。在原发和转移性乳腺癌患者的血浆中很容易检测到肿瘤DNA，而血浆DNA改变(LOH和MI)反映了肿瘤中的变化。应用对血浆DNA的微卫星分析可能有助于评估乳腺癌患者的肿瘤负担，特别是与QPCR结合时，对于不希望进行序贯骨髓抽吸的乳腺癌患者是首选的。
The aim of this study was to analyze plasma DNA from primary and metastatic breast cancer cases for tumor-specific alterations and to compare these findings with immunocytochemistry and estimation of cytokeratin 19 (CK19) mRNA for detection of micrometastases. DNA was extracted from plasma, lymphocytes, and microdissected tumor tissue sections obtained from 71 patients with breast cancer and 9 controls. DNA samples were analyzed for loss of heterozygosity (LOH) and/or microsatellite instability (MI) by PCR with two polymorphic markers (DM-1 and D16S400). Reverse transcription-quantitative PCR (QPCR) and immunocytochemistry were used for detection of CK19 mRNA and protein. Breast cancer plasma DNA displayed frequent LOH (31.3%) and MI (11.6%) supported by the same alteration in microdissected tumor DNA. Most notably, 10 of the 39 patients with primary breast cancer showed LOH (n = 6) or MI (n = 4). We compared plasma tumor DNA, plasma and bone marrow QPCR, and blood and bone marrow immunocytochemistry in 32 of the patients with primary cancer. Of these, only one patient had immunocytochemically detectable carcinoma cells in the blood, and three showed abnormally high levels of plasma CK19 mRNA. All four of these patients had plasma DNA alterations. We then compared bone marrow findings: of the 10 primary breast cancers that showed LOH or MI, 6 had elevated CK19 mRNA and 5 had immunocytochemically positive cells. Tumor DNA is readily detectable in plasma of primary and metastatic breast cancer patients, and plasma DNA alterations (LOH and MI) reflect those seen in the tumor. The application of microsatellite analyses to plasma DNA may be useful in assessing tumor burden in breast cancer patients, particularly when combined with QPCR, and is preferable for patients with breast cancer, for whom sequential bone marrow aspiration is undesirable.