Chen X Q, Bonnefoi H, Pelte M F, Lyautey J, Lederrey C, Movarekhi S, Schaeffer P, Mulcahy H E, Meyer P, Stroun M, Anker P
Faculté des Sciences, Pavilion des Isotopes, Geneva, Switzerland.
Clin Cancer Res. 2000 Oct;6(10):3823-6.
Tumor-derived circulating DNA has been found in the plasma of cancer patients. Alterations include decreased strand stability, mutations of oncogenes or of tumor suppressor genes, microsatellite alterations, and hypermethylation of several genes. RNA has also been found circulating in the plasma of normal subjects and cancer patients. Tyrosinase mRNA has been extracted from the serum of melanoma patients and subjected to RT-PCR. Moreover, the presence of cell-free EBV-associated RNA has been reported in the plasma of patients with nasopharyngeal carcinoma. Human telomerase comprises two RNA subunits, telomerase RNA template (hTR) and its catalytic component, telomerase reverse transcriptase protein (hTERT). Expression of these subunits correlates with telomerase activity. Using RT-PCR, we investigated whether these RNA subunits were present in the serum of 18 patients with breast cancer, 2 patients with benign breast disease, and 21 normal subjects. The presence of amplifiable RNA was confirmed in all tissue and serum samples using RT-PCR of glyceraldehyde-3-phosphate dehydrogenase RNA. hTR was found in 17 of 18 tumors (94%) and 5 of 18 serum samples (28%). hTERT was also detected in 17 of 18 tumors (94%) and in 4 of 16 available serum samples (25%). hTR and hTERT were undetectable in tissues and sera taken from 2 patients with benign disease and in the sera of 21 normal subjects. We conclude that RNA is detectable in the serum of breast cancer patients and that tumor-derived mRNA can be extracted and amplified using RT-PCR, even in patients with localized disease. This may have implications for cancer diagnosis and follow-up in the future.
肿瘤来源的循环DNA已在癌症患者的血浆中被发现。改变包括链稳定性降低、癌基因或肿瘤抑制基因的突变、微卫星改变以及多个基因的高甲基化。RNA也已在正常受试者和癌症患者的血浆中被发现循环存在。酪氨酸酶mRNA已从黑色素瘤患者的血清中提取并进行逆转录聚合酶链反应（RT-PCR）。此外，在鼻咽癌患者的血浆中已报道存在无细胞的EB病毒相关RNA。人端粒酶由两个RNA亚基组成，端粒酶RNA模板（hTR）及其催化成分，端粒酶逆转录酶蛋白（hTERT）。这些亚基的表达与端粒酶活性相关。我们使用RT-PCR研究了这两个RNA亚基是否存在于18例乳腺癌患者、2例乳腺良性疾病患者和21例正常受试者的血清中。通过甘油醛-3-磷酸脱氢酶RNA的RT-PCR在所有组织和血清样本中证实了可扩增RNA的存在。在18个肿瘤中的17个（94%）和18个血清样本中的5个（28%）中发现了hTR。在18个肿瘤中的17个（94%）以及16个可用血清样本中的4个（25%）中也检测到了hTERT。在2例良性疾病患者的组织和血清以及21例正常受试者的血清中未检测到hTR和hTERT。我们得出结论，乳腺癌患者的血清中可检测到RNA，并且即使是局限性疾病患者，肿瘤来源的mRNA也可通过RT-PCR提取和扩增。这可能对未来的癌症诊断和随访具有重要意义。
