Establishment of criteria and technique for molecular genetical diagnosis of urothelial cancer

我们已经报道了9号和17号染色体杂合性丢失的临床意义，现在我们尝试检测几个分子标记来应用于分子遗传学诊断。P53是已知的17号染色体杂合性丢失的靶基因，它的突变与病理特征有关。本研究证实P53基因突变可能是预测尿路上皮癌是否进展为浸润性癌的临床标志物，与放射敏感性无关。位于9号染色体上的MTS1和MTS2是肿瘤抑制基因。本研究证明这些基因的纯合性缺失或点突变在尿路上皮癌中常见，但与临床特征无明显关系，有待进一步研究证实。此外，尿路上皮细胞表达的黏附分子E-钙粘附素的减少也是常见的，并与临床和病理特征有关。多药耐药基因如mdr1、mrp、topo II和GST-pai等被认为与药物敏感性有关，在临床上具有重要意义，但在尿路上皮癌中未见异常表达。我们尝试建立以P53为分子标记的分子遗传学诊断技术这是突变的等位基因特异性扩增，避免了假阳性，并已成功地检测到尿沉渣中的癌细胞。而接下来利用尿沉渣短期培养，本研究证明免疫细胞化学染色可以检测原发肿瘤的P53突变。这可能是了解尿路上皮癌恶性程度的有效方法。

We have reported the losses of heterozygosity on chromosome 9 and 17 are clinically important and now we try to examine several molecular markers to apply for molecular genetic diagnosis.P53 is known as a target gene of loss of heterozygosity of chromosome 17 and the mutation of it is in relation to pathological features. This study has proved p53 mutation may be a clinical marker to predict whether the urothelial cancer will progress to be an invasive cancer and has no relation with radiosensitivity.MTS1 and MTS2, those are located on chromosome 9, are tumor supressor genes. This study has proved homozygous deletion or point mutation of these genes often occured in urothelial cancers but has not obvious relation with clinical features which must be proved with further study.Otherwise decrease of E-cadherin, which is one of adhesion molecule expressed in urothelium, is often observed and is in relation to clinical and pathological features.Multiple drug resistance genes such as MDR1, MRP,topo II and GST-pai are clinically important because they are considered to have a relation with drug sensitivity, but no abnormal expression is observed in urothelial cancers.And then we try to develop molecular genetic technique for diagnosis using p53 as a molecular marker.1st, we have modified MASA,that is mutant allele-specific amplification, to avoid false positive and have suceeded to detect cancer cell in urine sediment. And next using short term culture of urine sediment, this study has proved immunocytochemical staining can detect p53 mutation of primary tumor. This may be a powerful method to know malignancy of urothelial cancer.