ammalian have a stretch of a simple repeat sequence unit (TTAGGG) and in , length is 15–20 kb.
ifty to 200 bp of the telomeric DNA shortens at each round of mitosis. When average DNA reaches a
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➢肿瘤细胞分化异常的机制
•遗传学改变 •信号转化异常 •微环境的影响 •诱导分化治疗肿瘤
实用文档Biblioteka 肿瘤细胞的生长✓细胞增殖活性的原位检测方法及意义
细胞增殖活性： 细胞增生快慢的能力
DNA 含量测定 确定增生细胞的比例 Flow cytometry 法
DNA ploidy and proliferative activity as represented by the S-phase fraction (SPF).
➢anaKlyize-d6. 7
Several monoclonal antibodies reacting with different proliferating cell nuclear antigens have been described, such as PCNA, Ki-67 and MIB 1, KiS1 and others.
A link exists between high SPF values and increased risk of recurrence and death for
patients with primary BC,
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肿瘤细胞的生长
✓免疫组织化学方法
Only papers published in English in peer reviewed journals before June 2004 that include at least 100 evaluable patients were selected. In addition, the prognostic and predictive role of the proliferative markers had to be assessed through multivariate analyses. One hundred and thirty-two papers fulfilled these criteria and 159 516 patients
(C) Noncovalent binding of type IB enzymes. (D) Scheme of the 30 phosphotyrosine covalent bond in the Top1cc. The arrow indicates the
reversible (religation) reaction, which is favored under normal conditions. G) Scheme of the 50-实p用h文o档sphotyrosine covalent bond in the
•DNA拓扑异构酶通过形成短暂的单链裂解-结合循环， 催化DNA复制的拓扑异构状态的变化
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(A) Classification of human DNA topoisomerases. Type IB are the only enzymes that form cleavage complexes (cc) with 30-phosphotyrosyl (30-P-Y) intermediates.
degradation and fusion of chromosome ends by helping distinguish chromosome ends from a double strand break in the genomic DNA.
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物质代谢及酶的变化
✓核酸代谢
➢端粒酶
肿瘤的生物化学特性
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物质代谢及酶的变化 肿瘤细胞的分化 肿瘤细胞的生长 肿瘤细胞扩散的过程机制 肿瘤侵袭和转移相关基因
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实用文档
物质代谢及酶的变化
✓核酸代谢
•核酸增多是肿瘤迅速生长的物质基础 ➢DNA拓扑异构酶 ➢端粒酶
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物质代谢及酶的变化
✓核酸代谢
➢DNA拓扑异构酶
•存在于细胞核内的一类酶，他们能够催化DNA链的 断裂和结合，从而控制DNA的拓扑状态。
critically short length, about 4–7 kb, is arrested Irreversibly.
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物质代谢及酶的变化
✓核酸代谢 ✓蛋白质代谢 ✓糖代谢 ✓酶系统
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物质代谢及酶的变化
✓酶系统 ➢增殖相关和分化相关的酶
➢转化相关和演进相关的酶
转化相关
细胞恶变的指标。
The Ki-67/MIB 1 protein has a prognostic value
for many types of ma实l用文i档gnant tumors.
主要正常细胞发生转化， 总可出现这类酶活性的 改变。
演进相关的酶 酶活性于恶性程度呈平行关系的酶
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肿瘤细胞的分化
✓分化的概念
特定的生理功能
? 同一来源的
幼稚细胞
各种不同 类型细胞
特定的生化特征
(分化细胞)
特定的形态结构
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➢细胞分化特点:
•稳定性 •全能性 •选择性 •条件可逆性
未分化恶性肿瘤是由于起源组织中的干细胞 丧失了分化的能力。
Top2cc.
实用文档
物质代谢及酶的变化
✓核酸代谢
➢端粒酶
It is thought that length or integrity of chromos end is used as a mitotic counting mechanism in vitro
Each mammalian chromosome end has a distinctive DNA-protein structure, which prevents the