Gunn J, McCall J L, Yun K, Wright P A
Department of Surgery, University of Otago Medical School, New Zealand.
Lab Invest. 1996 Oct;75(4):611-6.
Tumor stage in bowel and breast cancer is the chief determinant of prognosis and the need for adjuvant therapy. The intermediate filament protein keratin 19 (K19) is expressed by epithelia and corresponding malignancies. Recently, the detection of K19 gene expression by RT-PCR has been reported as a sensitive tool for detecting occult metastasis to the lymph nodes and bone marrow of patients with primary epithelial tumors. Doubt has arisen, however, about the tissue specificity of K19 gene expression. In this study, we report a comparison of RT-PCR for K19 with another keratin, K20, in the lymph nodes and bone marrow of 15 patients with colorectal cancer, eight control patients who underwent bowel resection for benign disease, and four other control patients. K19 and K20 gene expression was detected in 84 and 26 of 109 lymph nodes and in 6 and 0 of 15 bone marrow aspirates, respectively, from colorectal cancer patients. K19 gene expression was also detected in 34 of 40 lymph nodes and in 5 of 12 bone marrow aspirates from control patients, whereas K20 gene expression was undetectable in any control sample. In conclusion, K19 RT-PCR lacks specificity as a marker of occult lymph node and bone marrow metastasis. In contrast, K20 RT-PCR was specific and should be evaluated further in future studies.
结直肠癌和乳腺癌的肿瘤分期是预后及辅助治疗需求的主要决定因素。中间丝蛋白角蛋白19（K19）由上皮组织及相应的恶性肿瘤表达。最近，有报道称通过逆转录聚合酶链反应（RT-PCR）检测K19基因表达是检测原发性上皮肿瘤患者隐匿性淋巴结和骨髓转移的敏感工具。然而，人们对K19基因表达的组织特异性产生了怀疑。在本研究中，我们报告了对15例结直肠癌患者、8例因良性疾病接受肠切除术的对照患者以及另外4例对照患者的淋巴结和骨髓中K19与另一种角蛋白K20进行RT-PCR比较的结果。在结直肠癌患者的109个淋巴结中的84个以及15份骨髓穿刺物中的6份中分别检测到K19和K20基因表达。在对照患者的40个淋巴结中的34个以及12份骨髓穿刺物中的5份中也检测到了K19基因表达，而在任何对照样本中均未检测到K20基因表达。总之，K19 RT-PCR作为隐匿性淋巴结和骨髓转移的标志物缺乏特异性。相比之下，K20 RT-PCR具有特异性，应在未来研究中进一步评估。
