Influence of Deleted in Colorectal Carcinoma Gene on Proliferation of Ovarian Cancer Cell Line SKOV-3 In Vivo and In Vitro

Objective To elucidate the effects of the deleted in colorectal carcinoma(DCC) gene on proliferation of ovarian cancer cell line SKOV-3.Method An exogenous recombinant eukaryotic expression vector pcDNA3.1(+)-DCC,containing human DCC cDNA coding sequences,was constructed and transfected into SKOV-3 cells(SKOV-3/DCC).The pcDNA3.1(+) transfected cells(SKOV-3/Neo) and SKOV-3 cells were used as the positive and negative controls,respectively.Expressions of DCC mRNA and protein were analyzed by RT-PCR and immunocytochemical analysis,respectively.Cell growth was detected by soft agar colony formation assay and MTT assay.Flow cytometry and transmission electron microscopy were used to assess the effects of DCC on cell cycle distribution and ultrastructure,respectively.BALB/c mice were used to evaluate the effects of DCC on tumorigenicity in vivo.Results RT-PCR and immunocytochemical analysis revealed the exogenous DCC gene was successfully transfected into SKOV-3 cell lines and obtained permanent expression.The half maximal inhibitory concentration(IC50) of SKOV-3/DCC cells was significantly lower than that of SKOV-3 or SKOV-3/Neo cells(all P<0.05).DCC expression caused SKOV-3 cells to be arrested in G1 phase(78.0%),and electron microscopic analysis showed SKOV-3/DCC cells displayed typical morphological changes of apoptosis.Two mice xenografted with SKOV-3/DCC cells showed no tumor tumorigenecity.The tumor volume of BALB/c mice bearing SKOV-3/DCC cells(3.403 mm3) was smaller than that of SKOV-3 cells(9.206 mm3).Conclusion DCC gene may play an important role in suppressing the growth of SKOV-3 cell line and inducing apoptosis.

A study of the relationship between frequency of allelic deletion of chromosome 17p and late-stage colorectal carcinoma

Late stage colorectal carcinoma is very complicated in its molecular mechanisms. One hundred andnine cases of colorectal carcinomas were analyzed with RFLP method for the allelic deletion of chromosome 17short arms (ADCC17p) In this study. The results showed that frs(luency of allelic deletion of chromosome 17short arms (FADC17P) in Dukes’ D stage (95 % ) was higher than those in Dukes’ A, B. C stages (54% 68% ); Fisher’s exact test P <0. 01; FADC17p in colorectal carcinomas with distant metastasis (95 % ) washigher than those without distant metastasis, Fisher’s exact test P <0. 01 However, there were no significant differences in FADC 1 7p between the colorectal carcinomas with lymph node metastasis and those without lymph node metastasis (P >0. 05). Therefore, it is considered that ADC17p is an important diagnosticmarker of late stage colorectal carcinomas, and indicates a poor prognosis.

DCC、P53及VEGF在结直肠腺癌癌组织中的表达

目的检测DCC、P53及VEGF在41例结直肠癌中的表达情况,以探讨三者表达的相关性。方法应用免疫组化二步法检测。结果41例结直肠癌的组织中,DCC表达阳性10例,阳性率为24.4%,而P53与VEGF的阳性率分别为63.4%及65.9%。DCC基因表达与P53、VEGF无明显相关性。结论P53与VEGF表达存在明显相关关系(P<0.05)。

大肠腺瘤、腺癌中DCC基因表达与201密码子点突变的研究

目的 探讨国人大肠腺瘤、腺癌中结直肠缺陷 (DCC )基因蛋白表达与该基因 2 0 1密码子的突变情况 ,及其与大肠肿瘤临床病理因素的关系。方法 采用免疫组织化学和PCR结合限制性酶切多态性分析 (PCR RFLP)方法 ,检测 3 0例正常大肠黏膜、40例大肠腺瘤、46例大肠癌及相应癌旁黏膜组织中DCC基因蛋白表达及 2 0 1密码子突变情况。结果 DCC蛋白在正常大肠黏膜、腺瘤组织及癌组织中阳性表达率分别为 10 0 %、83 %和 2 8% ,三者比较 ,均有显著性差异 (P <0 .0 5 )。腺瘤伴重度不典型增生者DCC蛋白表达缺失率 ( 5 5 % )明显高于腺瘤伴轻、中度不典型增生者 ( 3 % )。DukesC、D期大肠癌DCC基因蛋白表达缺失率明显高于DukesA、B期。腺瘤伴重度不典型者 2 0 1密码子突变率 ( 64 % )明显高于腺瘤伴轻、中度不典型增生者 ( 2 1% ) (P <0 .0 5 ) ;大肠癌突变率最高达 78% ;DukesC、D期大肠癌 2 0 1密码子突变率明显高于A、B期 ;大肠癌DCC基因 2 0 1密码子纯合突变率( 5 0 % )显著高于癌旁黏膜 ( 6% ) ,有显著性差异。 2 0 1密码子突变与患者性别、年龄、肿瘤组织学分型等因素无关。结论 大肠腺瘤向癌演变的过程中DCC基因 2 0 1密码子突变率和蛋白表达缺失率逐渐增高 。

DCC基因在卵巢肿瘤中的表达及临床意义

目的 通过研究卵巢肿瘤组织中结直肠抑癌基因（deleted in colorectal alcarcinoma,DCC）的表达,探讨其在卵巢肿瘤发生发展中的作用.方法 应用免疫组织化学方法检测20例正常卵巢、30例卵巢恶性肿瘤、20例卵巢良性肿瘤组织中DCC的基因表达缺失情况.用χ2检测DCC在卵巢肿瘤中的表达是否存在差异.结果 正常卵巢组织中DCC表达缺失率为0%,卵巢良性肿瘤组织中为20%,卵巢恶性肿瘤组织中为60%,卵巢恶性肿瘤中,临床分期Ⅰ～Ⅱ期的DCC基因表达缺失率为25%,Ⅲ～Ⅳ期的DCC基因表达缺失率为73%.结论 在卵巢恶性肿瘤组织中,DCC基因表达缺失或低表达.DCC基因表达缺失与卵巢肿瘤的发生发展有关,其检测可对卵巢肿瘤的性质进行初步判断.

结直肠癌患者血清中瘦素表达的研究

目的探讨血清瘦素水平与结直肠癌各种临床病理改变的关系。方法用双抗体夹心ABC-ELISA法检测30例无营养不良的结直肠癌患者(肿瘤组)和24例健康成年人(对照组)血清瘦素水平,分析结直肠癌不同临床病理特征下血清瘦素水平的差异;检测肿瘤组患者的血清CEA及CA19-9水平,用RT-PCR方法测定肿瘤组肿瘤标本中K-ras、p53、腺瘤性结肠息肉病(APC)基因及结直肠癌缺失基因(DCC)mRNA的表达水平。结果肿瘤组血清瘦素水平〔(3.53±1.72)μg/L〕明显高于对照组〔(2.27±1.01)μg/L〕,P<0.05,且这种差异与性别无关。肿瘤组中不同肿瘤部位、不同TNM分期间的血清瘦素水平差异无统计学意义(P>0.05);但随着肿瘤分化程度的降低,血清瘦素水平呈现下降趋势,其中低分化者的血清瘦素水平明显低于高分化者和中分化者(P<0.05)。肿瘤学的相关性分析结果显示,血清瘦素水平与结直肠癌患者的血清CEA和CA19-9水平,肿瘤组织的癌基因K-ras以及抑癌基因p53、APC和DCC的表达均无相关性(P>0.05)。结论结直肠癌患者血清中的瘦素水平高于正常人;肿瘤的分化程度影响了血清瘦素的表达,但结直肠癌的TNM分期、部位和血清肿瘤标志物的水平与血清瘦素水平无关,与结直肠癌发生、发展密切相关的各种基因的表达与血清瘦素水平也无关。

结肠癌p16基因缺失与突变的研究

目的 :探讨p16抑癌基因外显子 2缺失、突变与结肠癌发生、发展的关系。方法 :采用聚合酶链反应 (PCR)、聚合酶链反应—单链构象多态性 (PCR SSCP)分析方法检测结肠癌中p16基因外显子 2的缺失、突变。结果 :30例结肠癌样本中 ,高分化及低分化腺癌各 1例PCR扩增无扩增产物 ,可能为p16基因缺失 ;其余 2 8例结肠癌、正常组织均有产物出现。SSCP分析 ,30例结肠癌中未见异常泳动带 ,无p16基因突变。结论 :p16基因外显子 2缺失可能很少参与结肠癌的发生发展 ;而p16基因突变可能与结肠癌发生无关。