肿瘤的生物学特.ppt

肿瘤细胞扩散的过程机制1细胞黏附与细胞黏附分子2IgSF跨膜蛋白具有与Ig类似的结构3肿瘤细胞扩散的过程机制细胞黏附与细胞黏附分子SelectinfamilycancercellsadheretobyaprocesssimilartothatofLChoming.Inthismodel,cellsinflowarecapturedontheendothelialsurface.transientadhesiveinteractionsbycellswithendothelialselectins(rolling),andfirmlyanchoredon(firmadhesion)toenableentryintotheunderlyingtissue.Theselectins,particularlyE-selectin,arerecognizedtomediateadhesionandthuspotentiateofcertaincancers肿瘤细胞扩散的过程机制细胞黏附与细胞黏附分子Selectinfamily肿瘤细胞扩散的过程机制细胞黏附与细胞黏附分子CD44AtransmembraneproteinEssentialforthehomingandpropertiesofleukemicCells,CD44hasalsobeenfoundtosupportanchorage-independentgrowthinvitroandtumorgrowthandinexperimentalmodelsofsolidcancers肿瘤细胞扩散的过程机制肿瘤细胞从原发灶分离的机制肿瘤细胞表面黏附分子减少。癌细胞钙含量降低恶性肿瘤细胞间连接结构数量减少肿瘤细胞表面电荷增加肿瘤细胞向周围组织的浸润01细胞外基质的降解02瘤细胞的运动03趋化因子的作用04肿瘤血管生成05肿瘤的生物化学特性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物质代谢及酶的变化核酸代谢1物质代谢及酶的变化2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3DNA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。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核酸代谢物质代谢及酶的变化ClassificationofhumanDNAtopoisomerases.TypeIBaretheonlyenzymesthatformcleavagecomplexes(cc)with30-phosphotyrosyl(30-P-Y)intermediates.NoncovalentbindingoftypeIBenzymes.(D)Schemeofthe30phosphotyrosinecovalentbondintheTop1cc.Thearrowindicatesthereversible(religation)reaction,whichisfavoredundernormalconditions.G)Schemeofthe50-phosphotyrosinecovalentbondintheTop2cc.0102物质代谢及酶的变化核酸代谢端粒酶endisusedasamitoticcountingmechanismItisthoughtthatlengthorintegrityofchromosome01EachmammalianchromosomeendhasadistinctiveDNA-proteinstructure,whichpreventsthedegradationandfusionofchromosomeendsbyhelpingdistinguishchromosomeendsfromadoublestrandbreakinthegenomicDNA.invitro02物质代谢及酶的变化Mammalianhaveastretchofasimpler