【作者】 许传亮；

【导师】 孙颖浩； 钱松溪； 王红阳；

【作者基本信息】 第二军医大学 ， 外科学， 2002， 博士

【摘要】 原发性肾细胞癌（简称肾癌，RCC）是泌尿系统常见的恶性肿瘤之一，其发生和发展是一多基因参与和受多因素影响及调控的复杂过程。蛋白质酪氨酸激酶和蛋白质酪氨酸磷酸酶精确调控的蛋白质酪氨酸磷酸化水平在恶性肿瘤的发生发展中起着极为重要作用。很多蛋白质酪氨酸激酶都是由原癌基因编码，目前也已证实编码某些蛋白质酪氨酸磷酸酶的基因(如PTEN基因等)在体内起着抑癌基因的作用。PTP BAS基因为编码具有蛋白酪氨酸磷酸酶活性的基因，1994年，Maekawa等最早将PTP BAS从人类嗜碱性粒细胞白血病的细胞株中克隆出其全长cDNA，并发现PTP BAS在多种人种组织中表达，特别是在肾脏、肺和胎脑中呈高表达。研究发现因其与Fas诱导的细胞凋亡有关，故又称之为Fas相关的磷酸酶1(FAP 1)。在结肠癌、胰腺癌、胃癌、T细胞性白血病、卵巢癌、肝癌、乳癌、胃癌、肺癌及某些肉瘤中均已进行了有关PTP BAS的相关研究。尽管PTP BAS在肾脏中呈高表达，但有关其在原发性肾细胞癌的发生发展中所起的作用尚未见有报道。本研究旨在通过应用Northern Blot技术，分析原发性肾癌组织PTP BAS基因的表达情况，从mRNA表达水平研究原发性肾癌发生过程中是否有PTP BAS表达水平的改变，并初步探讨PTP BAS基因与原发性肾癌发生的关系。Northern Blot结果显示：在31例RCC标本中，PTP BAS mRNA在肾癌组织内的表达水平显著低于对应的癌旁肾组织内表达水平（p<0.01）。癌旁组织中9.5 kb转录子的表达率为93.5%%(29/31)，而肾癌中9.5 kb转录子的表达率则为74.2%(23/31)。293细胞及人肾癌细胞(786 O、A498)呈无或低表达。9.5kb的转录子表达水平与患者的年龄、性别、肿瘤的部位、侧别、大小、分期及病理类型无关（p>0.05）。 本研究在抽提肾癌及其癌旁组织的总RNA中发现肾癌癌旁组织的RNA比肾癌组织的RNA更易降解。为证实这一点并探讨其存在的原因及其与原发性肾癌发生发展的关系，通过测量30对距断流相同时间的肾癌组织与癌旁组织总RNA中28S与18S的比值，发现相同缺血时段肾癌组织的总RNA的28S/18S值明显高于相应的癌旁组织（p<0.05），且同一病肾中肾癌组织与癌旁组织的总RNA<WP=7>的28S/18S值随着距断流时间的延长而逐渐下降，相同时段的肾癌组织的总RNA的28S/18S值明显高于相应癌旁组织的28S/18S值（p<0.01）；癌旁组织的总RNA的28S/18S值于距肾断流40分钟时已接近1，但相应的肾癌组织的总RNA的28S/18S值于距断流90分钟才接近1。以总RNA的28S为内参照，采用Northern Blot技术研究发现：16对肾癌组织的β 肌动蛋白的表达高于相应的癌旁组织，进一步证明肾癌癌旁组织的RNA比肾癌组织的RNA更易降解。为进一步明确肾癌癌旁组织的RNA比肾癌组织的RNA更易降解的原因，并分析其在肾癌发生发展中的作用。采用EnvisionTMTM法检测了肾癌组织与癌旁组织RNase 1的表达，发现癌旁组织肾小管的RNase 1的表达明显高于肾癌组织（p <0.01），并可见于肾小管管腔内；肾癌RNase 1表达与肾癌患者的年龄、性别、肿瘤的部位、侧别、大小及分期无关(p>0.05)，但与肿瘤的病理类型有关，颗粒细胞癌的RNase 1的表达明显高于透明细胞癌和混合性细胞癌（p<0.01），而透明细胞癌和混合性细胞癌的RNase 1的表达无显著性差异(p>0.05)。同时应用Northern Blot技术研究18对原发性肾癌病人的肾癌组织与癌旁组织的RNase抑制剂(RI)的表达，发现肾癌组织的RI的表达明显高于相应癌旁组织的RI。786 O、A498肾癌细胞株RI呈高表达。但RI的表达与肾癌患者的年龄、性别、肿瘤的部位、侧别、大小、分期及病理类型无关（p>0.05）。本研究结果表明：PTP BAS基因表达水平降低在原发性肾癌的发生过程中可能起了一定的作用，可能是肾癌的一个抑癌基因。肾癌癌旁组织的总RNA比相应的肾癌组织的总RNA更易降解，其原因可能是肾癌组织的RNase表达降低及RI表达升高所致的RNase活性降低。肾癌组织的RNase活性降低可能是肾癌出现异常增殖的原因之一。提高肾癌中的RNase活性可能成为治疗肾癌的一种有效方法。更多还原

【Abstract】 Primary renal cell carcinoma(RCC) is one of the most common malignant tumor in urological neoplasms. Just like other tumors, the development of RCC is a complex process involving many genes and factors. Protein tyrosine phosphorylation, which plays a pivotal role in the regulation of cellular activities such as growth, differentiation, gene transcription and cell motility, is regulated by the balance between protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Disregulation in the activity of either of these players can lead to cellular transformation. Many protein tyrosine kinases are encoded by proto oncogenes and some protein phosphatases, such as PTEN, act as tumor suppressors. PTP BAS is a cytoplasmic PTP that has been originally cloned from a human basophilic leukaemia cell line by Maekawa and his colleagues in 1994. PTP BAS is expressed in various human tissues, especially in the kidney, lung and fetal brain at high levels. The apoptosis inducing membrane protein, Fas/CD95, was found to associate with Fas associated phosphatase 1(FAP 1) which is identical with PTP BAS. PTP BAS has been studied on the various malignancies such as colonal carcinoma, pancreas carcinoma, stomach carcinoma, T cell leukaemia, ovary carcinoma, liver carcinoma, breast carcinoma, lung carcinoma and some other sarcomas, but not the RCC, even though over expression of PTP BAS was reported in renal tissue. Our study was to investigate whether the expression of the PTP BAS in RCC tissues detected by Northern blot was associated with the development and the progress of the RCC on the level of mRNA. Our results showed that the level of PTP BAS mRNA expressed in the 31 RCC tissues was significantly lower than that in<WP=9>their adjacent normal renal tissues（p <0.01）, and the expression rate of the 9.5 kb transcripts in RCCs and their adjacent normal renal tissues was 74.2%(23/31) and 93.5%%(29/31), respectively. It was also found that there was no or low expression in the 293 cell strain and the RCC cell stains (786 O、A498). Statistically, we found no relationship between the expression level of 9.5kb transcripts and the patients’ age, gender, localization of the carcinoma, side of the lesion, volume, tumor stage and pathological type of RCC（p>0.05）.Occasionally we noticed a common phenomenon that the isolated RNA in the adjacent normal renal tissues tended to degrade than that in the carcinoma tissues during the process of isolating the total RNA from the tissues. To confirm this finding and to investigate the relationship between the RNA degradation and the development and the progress of the RCC, we measured the ratios of 28s to 18s of the total RNA isolated from the 30 pairs of RCC and their adjacent tissues obtained at the same time of post nephrotectomy. As a result, we found that: (1) the ratios of 28s to 18s of the total RNA isolated from RCC were significantly higher than those from their adjacent tissues（p <0.05）. (2) In the same patient’s specimen, the ratios decreased in a time related fashion after nephrotectomy, and the ratios of RCC’s RNA were much higher than those of their adjacent tissues’ RNA（p <0.01）. (3)The ratios of the RCC tissues’ RNA were nearly 1 at 40 min after clamping of the artery while the ratios of the adjacent tissues’ RNA were nearly 1 at 90 min after clamping of the artery. (4)Theβ actin mRNA of 16 RCCs was much higher than that of their accordingly adjacent tissues by Northern blotting with 28S RNA as internal control. This confirmed that the RNA from the adjacent tissues of RCCs was apt to decay than that from RCC tissues.To clarify the underlying cause, we evaluated the expression of the RNase 1 in both RCC and their adjacent tissues by the EnvisionTM technique. The results showed that the expression of RNase 1 in the renal tubular cells was much higher than that in RCC cells and the RNase 1 was also detected in the renal tubular lumen. We also found that the expression of the RNase 1 in RCC had relationship with the the pathological type, but not the patient更多还原