The level of cadherin-6 mRNA in peripheral blood is associated with the site of metastasis and with the subsequent occurrence of metastases in renal cell carcinoma

BACKGROUND: To evaluate the significance of the presence of circulating renal cell carcinoma (RCC) cells in the development of metastases, the authors extended a previous study to quantify cadherin-6 mRNA levels in association with the pattern of metastasis. METHODS: Cadherin-6 mRNA levels were measured in peripheral blood samples from 66 patients with RCC, including 55 patients who had newly diagnosed RCC (43 without metastases and 12 with metastases) and 11 patients who had recurrent RCC. For quantitative polymerase chain reaction analysis, a cutoff value was determined in blood samples from 25 healthy volunteers and was verified in samples from 5 healthy controls and from 10 patients who had other malignancies. The correlation between the site of metastases and the cadherin-6 mRNA level was analyzed, and a follow-up study (median, 39 months) to track subsequent metastases was performed after patients underwent nephrectomy. RESULTS: Cadherin-6 was found in 69.9% of patients with metastases and in 34.9% of patients without apparent metastases (P = 0.0099). In the group of patients with recurrent RCC, patients who had only pulmonary metastases had a significantly lower positivity rate (25.0%) compared with patients who had distant metastases (85.7%; P = 0.044). Among 43 patients with newly diagnosed RCC, 5 of 15 patients who were positive for cadherin-6 had metastases after nephrectomy, whereas only 2 of the 28 patients with negative cadherin-6 status had recurrent disease (P = 0.0398). In addition, the recurrence-free survival of patients who were positive for cadherin-6 was poorer compared with the survival of patients who were negative for cadherin-6 (P = 0.062). CONCLUSIONS: The quantification of cadherin-6 mRNA in peripheral blood may be a significant predictive marker for current and future metastases. However, subsequent metastases did not always correlate with levels of cadherin-6 mRNA. This may have been due either to the small numbers of circulating tumor cells or to the low levels cadherin-6 mRNA in circulating tumor cells.     

肺癌患者外周血中表面活性蛋白DmRNA的表达及临床意义

背景与目的 : 循环癌细胞的灵敏检测对于肺癌患者的预后及选择合适的治疗方法很 重要. 为此,我们建立了利用表面活性蛋白 D(surfactant protein D, SP-D)作为基因标志 的 RT-PCR方法,检测肺癌患者外周血中的癌细胞,并初步探讨其临床意义. 方法 : 采用优化 的套式 RT-PCR方法,对 26例伴肺外转移肺癌患者,37例无转移肺癌患者,15例良性肺疾病患 者及 15例健康志愿者外周血中 SP-D mRNA的表达进行分析. 结果 : 1)该方法灵敏度可达 1× 10- 6, 特异性强 ; 2)采用此方法,伴肺外转移和无转移肺癌患者外周血中 SP-D mRNA的检出 率分别为 92.3% (24/26)和 24.3% ( 9/ 37),所有良性肺疾病患者和健康对照外周血中均未 见 SP-D mRNA 的表达. 结论 : SP-D mRNA可能是检测肺癌患者外周血中是否存在癌细胞的一 个有价值的指标,对肺癌的转移倾向有一定的提示作用,并有可能为制定治疗方案和评估预 后提供重要的参考依据.     

Detection of tyrosinase mRNA by an optimised nested RT-PCR in the peripheral blood of patients with advanced malignant melanoma

Malignant melanoma (MM) has a high metastatic potential even in small primary lesions, and an early distinction between localized and regionally/distally advanced disease is of major importance for the patients' treatment and, consequently, for their survival. Exploiting the fact that tyrosinase is a tissue specific enzyme which is only expressed in normal skin melanocytes and MM cells that invade the blood during metastasizing, the objective of our study was to optimise the nested RT-PCR assay for the detection of tyrosinase mRNA and, hence, to detect circulating melanoma cells (CMC) in whole venous blood of MM patients. Eighteen MM patients (stage III and IV, according to AJCC) and 8 healthy subjects were included in our study. Following optimisation of the procedure, the lowest detection limit of 10 MM cells per 1 ml of the blood was achieved. Tyrosinase mRNA was detected in 27.8% (5/18) of blood samples from MM patients and in none of the healthy volunteers. Preliminary results of this study suggest that the method is sensitive and specific to the CMC detection in the peripheral blood and may thus be helpful in determining the disease stage and, consequently, in planning treatment.     

检测肺癌患者外周血和骨髓微转移的临床意义

目的探讨检测肺癌患者外周血和骨髓微转移的特异性、敏感性及临床意义。方法应用巢式RT-PCR技术,检测59例肺癌患者、11例肺部良性病变患者和20例健康人外周血、骨髓中CK19 mRNA表达。结果巢式RT-PCR检测技术的敏感性达到10-6。59例肺癌患者中,20例检测出外周血微转移,13例检测出骨髓微转移,其阳性检出率分别为33.9％(20/59)和22.0％(13/59),二者有显著正相关(P<0.05)。肺癌患者外周血和骨髓微转移与肺癌组织学类型、细胞分化程度及P-TNM分期均存在密切关系(P<0.05或P<0.01)。肺良性病变患者、健康人外周血和骨髓中均未检测出CK19 mRNA表达。结论肺癌患者外周血和骨髓中均存在用常规方法检测不出的微转移;应用巢式RT-PCR技术检测肺癌患者外周血和骨髓中CK19 mRNA表达,对肺癌微转移的分子诊断具有重要的理论意义和临床应用前景。