Molecular biological study on genesis and proliferation of renal malignant tumor

本研究以肾细胞癌患者手术切除的组织材料为研究对象，利用分子生物学技术，对8例肾癌患者进行了染色体分析，旨在阐明肾恶性肿瘤的发生和增殖机制。其中#3和#7染色体数目异常的发生率较高，#2和#6染色体的结构异常发生率较低。第二年，从这8个肿瘤中提取DNA，然后进行各种癌基因表达的评估。但未发现明显异常。50例膀胱癌中，2例(4%)应用聚合酶链式反应(PCR)方法检测到H-ras癌基因的过度表达及其点突变。该方法通过聚合酶链式反应扩增含有密码子12的DNA片段，检测反应产物对限制性内切酶的敏感性，并用寡核苷酸探针进行斑点杂交，从新鲜或冷冻的肿瘤组织、尿细胞和石蜡切片中提取的少量DNA中可检测到点突变。这些结果表明，我们的方法并不优于筛查，但在对容易阳性的病例进行随访时非常有用。特别强调了尿细胞作为检测样本的可行性，因为它对患者无创，易于重复性。在第三年，我们努力尝试公布我们的结果。

We started this study in aiming to clarify the mechanism of genesis and proliferation of renal malignant tumors by means of molecular biology technique utilizing tissue materials surgically extirpated from the patients with renal cell carcinoma.In the 1st year, chromosomal analysis was carried out on 8 tumors of renal cell carcinoma. There were relatively high incidence of numerical aberrations in #3 and #7 chromosoms, and a lesser incidence of constitutional aberrations, i.e. long-arm aberrations in #2 and #6 chromosoms.In the 2nd year, DNAs were extracted from these 8 tumors and then subjected to evaluation of various oncogene expression. However, no significant abnormaility was found. On the other hand, it was successful to detect over expression of H-ras oncogene and its point mutation by means of polymerase chain reaction(PCR) method in 2 out of 50 bladder cancers (4%). In this method, the DNA segments including codon 12 were amplified by PCR, and the reaction products were examined for their susceptibility to the restriction enzyme, and by dot blot hybridization assay with oligonucleotide probes.Point mutations were detectable in small amounts of DNAs isolated from fresh or frozen tumor tissues, urine cells and paraffin sections. These results indicated that our method was not superior as screening,but very useful in following up the readily positive cases. Particularly emphasized is feasibility of urine cells as test samples because of their non invasiveness to the patients and easy repeatability.In the 3rd year, we made efforts to try to publicate our results.