Schwarzenbach Heidi, Müller Volkmar, Milde-Langosch Karin, Steinbach Bettina, Pantel Klaus
Department of Tumour Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, Hamburg, Germany.
Mol Biosyst. 2011 Oct;7(10):2848-54. doi: 10.1039/c1mb05197k. Epub 2011 Jul 22.
High levels of DNA and RNA released by apoptotic and necrotic cells circulate in the blood of cancer patients. In the present study we determined the applicability of the quantification of nucleic acids and their genetic alterations as minimally invasive tool for breast cancer screening. The relative concentrations of DNA and RNA were determined in preoperative serum of 102 breast cancer patients, 32 patients with benign breast disease and 53 healthy women. The mean follow-up time of the cancer patients was 6.2 years. Loss of heterozygosity (LOH) at four polymorphic markers (D13S159, D13S280, D13S282 at region 13q31-33 and D10S1765 at PTEN region 10q23.31) was analyzed by PCR-based fluorescence microsatellite analyses using cell-free DNA. The serum levels of DNA (p = 0.016) and RNA (p = 0.001) could differentiate between healthy women and cancer patients, but could not discriminate malignant from benign breast lesions. A significant correlation of serum DNA with RNA levels was observed in all groups (p = 0.018). Increased serum DNA levels (but not RNA levels) in cancer patients were associated with a poorer overall (p = 0.021) and disease-free survival (p = 0.025). The occurrence of LOH at all markers significantly correlated with lymph node status (p = 0.026). In addition, the LOH frequency at D13S280 (p = 0.047) and D13S159 (p = 0.046) associated with overall and disease-free survival, respectively. In conclusion, the quantification of cell-free tumour DNA had diagnostic and prognostic values in breast cancer patients, and DNA loss at the region 13q31-33 may be an indication of lymphatic tumour cell spread.
凋亡和坏死细胞释放的高水平DNA和RNA在癌症患者的血液中循环。在本研究中，我们确定了核酸定量及其基因改变作为乳腺癌筛查微创工具的适用性。测定了102例乳腺癌患者、32例乳腺良性疾病患者和53例健康女性术前血清中DNA和RNA的相对浓度。癌症患者的平均随访时间为6.2年。通过基于PCR的荧光微卫星分析，使用游离DNA分析了四个多态性标记（13q31 - 33区域的D13S159、D13S280、D13S282以及PTEN区域10q23.31的D10S1765）的杂合性缺失（LOH）情况。血清DNA（p = 0.016）和RNA（p = 0.001）水平能够区分健康女性和癌症患者，但无法区分乳腺恶性病变和良性病变。在所有组中均观察到血清DNA与RNA水平存在显著相关性（p = 0.018）。癌症患者血清DNA水平升高（而非RNA水平）与较差的总生存期（p = 0.021）和无病生存期（p = 0.025）相关。所有标记处的LOH发生情况与淋巴结状态显著相关（p = 0.026）。此外，D13S280（p = 0.047）和D13S159（p = 0.046）处的LOH频率分别与总生存期和无病生存期相关。总之，游离肿瘤DNA定量在乳腺癌患者中具有诊断和预后价值，13q31 - 33区域的DNA缺失可能表明肿瘤细胞发生淋巴转移。
