Demethylation of the γ-synuclein gene CpG island in colorectal cancer and its clinical significance

Objective To explore the relationship between γ-synuclein gene expression and CpG island demethylation in colorectal cancer (CRC), and the relationship between the demethylation and clinicopathological factors of CRC. Methods The expression of γ-synuclein mRNA was examined in 30 pairs of tumor tissues and tumor-matched non-neoplastic adjacent tissues (NNAT) by RT-PCR.CRC cell lines including COLO205, LoVo, and SW480 were used and treated with a demethylating agent, 5-aza-2'-deoxycytidine (5-aza-C). Before and after the treatment, the expression of γ-synuclein mRNA in the cells was determined by RT-PCR, and bisulfite sequencing PCR was also used to analyze methylation status of CpG island. The methylation status of γ-synuclein was then examined in 67 CRC samples and 30 NNAT samples by nested methylation-specific PCR (NMSP) and real time methylationspecific PCR (real-time MSP). The relationship between the demethylation of γ-synuclein in CRC and clinicopathological factors was analyzed. Results The mean γ-synuclein mRNA expression was 0.66±0.34 in CRC samples, which was much higher than 0.45±0.26 in NNAT samples (P=0.011). 5-aza-C could induce expression and demethylation of γ-synuclein in COLO205, LoVo and SW480 cells. Γ-Synuclein gene was demethylated in 80.0%(24/30) of the CRC samples and 50.0%(15/30) of the NNAT samples.The demethylated status of γ-synuclein was much higher in CRC samples than that in NNAT samples (P=0.030), and was significantly correlated with clinical stage, lymph node involvement, and distant metastasis of CRC (P＜0.05). Conclusion The upregulation of γ-synuclein expression in CRC is primarily attributed to the demethylation of CpG island, which may be used as a marker for prognosis.     

Demethylation of the γ-synuclein gene CpG island in colorectal cancer and its clinical significance

Objective To explore the relationship between γ-synuclein gene expression and CpG island demethylation in colorectal cancer (CRC), and the relationship between the demethylation and clinicopathological factors of CRC. Methods The expression of γ-synuclein mRNA was examined in 30 pairs of tumor tissues and tumor-matched non-neoplastic adjacent tissues (NNAT) by RT-PCR.CRC cell lines including COLO205, LoVo, and SW480 were used and treated with a demethylating agent, 5-aza-2'-deoxycytidine (5-aza-C). Before and after the treatment, the expression of γ-synuclein mRNA in the cells was determined by RT-PCR, and bisulfite sequencing PCR was also used to analyze methylation status of CpG island. The methylation status of γ-synuclein was then examined in 67 CRC samples and 30 NNAT samples by nested methylation-specific PCR (NMSP) and real time methylationspecific PCR (real-time MSP). The relationship between the demethylation of γ-synuclein in CRC and clinicopathological factors was analyzed. Results The mean γ-synuclein mRNA expression was 0.66±0.34 in CRC samples, which was much higher than 0.45±0.26 in NNAT samples (P=0.011). 5-aza-C could induce expression and demethylation of γ-synuclein in COLO205, LoVo and SW480 cells. Γ-Synuclein gene was demethylated in 80.0%(24/30) of the CRC samples and 50.0%(15/30) of the NNAT samples.The demethylated status of γ-synuclein was much higher in CRC samples than that in NNAT samples (P=0.030), and was significantly correlated with clinical stage, lymph node involvement, and distant metastasis of CRC (P＜0.05). Conclusion The upregulation of γ-synuclein expression in CRC is primarily attributed to the demethylation of CpG island, which may be used as a marker for prognosis.     

肠道干细胞标记基因Lgr5在结直肠癌中的表达及其意义

目的 探讨结直肠癌组织中Lgr5的表达及其意义.方法 采用SP免疫组织化学方法 检测139例结直肠癌组织中Lgr5的表达.结果 139例结直肠癌中管状腺癌、黏液腺癌和乳头状腺癌的Lgr5蛋白高表达率分别为87.1%、100.0%和75.0%;黏膜及黏膜下层、肌层、浆膜及浆膜外层的lgr5高表达率分别为50.0%、82.6%、93.9%;淋巴结转移阳性组和阴性组的Lgr5高表达率分别为94.6%和81.9%.结直肠癌组织中Lgr5蛋白表达水平与其浸润程度、淋巴结转移、Dukes分期均明显相关(P<0.05),而与其年龄、性别、组织学类型、病理分期无明显相关(P>0.05).结论 Lgr5的表达与结直肠癌浸润程度及淋巴结转移状况密切相关,可能参与结直肠癌的发生、发展.

Abstract：

Objective To investigate the expression of leucine-rich-repeat-containing G-protein-coupled receptor 5 (Lgr5) and its significance in colorectal carcinoma. Methods The expression of Lgr5 was examined by immunohistochemistry in 139 cases of colorectal cancer, and its relationship with clinical characteristics was analyzed. Results In 139 colorectal carcinoma samples, the Lgr5 expression rate in tubular adenocarcinoma, mucinous adenocarcinoma, papillary adenocarcinoma was 87.1%, 100.0% and 75.0% respectively. The Lgr5 expression rate in mucous layer, muscular layer, and membrane serosa was 50.0%, 82.6%, 93.9% respectively. High expression levels of Lgr5 were detected in 53 of 56 (94.6%) patients with lymph node metastasis and in 68 of 83 (81.9%) patients without lymph node metastasis. The expression of Lgr5 protein was higher in the tissues with deeper infiltration, advanced Dukes stage, or lymph node or remote metastasis. Conclusion The expression of Lgr5 is significantly correlated with invasion and lymph node metastasis, and may play an important role in the occurrence and development of epithelial colorectal carcinoma. Overexpression of Lgr5 provides an important implication of malignancy and prognosis for colorectal carcinoma.     

沉默STAT3基因对人胰腺癌细胞体内生长能力的影响

Objective To investigate the effect and mechanism of RNAi-mediated STAT3 gene silence on human pancreatic cancer cells growth in vivo. Methods STAT3 shRNA expression vector was stably transfected to SW1990 cells. STAT3 and p-STAT3 protein was examined using Western blot. The growth ability of SW1990 cells in vivo was determined in a subcutaneous tumor model of nude mice. Western blot was performed to detect the protein expression of Bcl-xL and cyclin D1. Results The protein expression of STAT3 and p-STAT3 decreased by 90% and 92% by stable transfection of STAT3 shRNA expressing vectors(P ＜0. 05). Inhibition of STAT3 with RNAi significantly inhibited the growth ability of SW1990 cells in vivo( P ＜ 0. 05 ). The tumor weight significantly decreased( P ＜ 0. 05 ). Moreover, the relative Bcl-xL and cyclinD1 protein expression in SW1990-RNAi cells reduced by 56% and 50% compared with that of the parental SW1990 cells, respectively (P ＜ 0. 05). Conclusions Inhibition of STAT3 with RNAi significantly inhibits the growth ability of pancreatic cancer cells through down-regulating Bcl-xL and cyclin D1.     

沉默STAT3基因对人胰腺癌细胞体内生长能力的影响

Objective To investigate the effect and mechanism of RNAi-mediated STAT3 gene silence on human pancreatic cancer cells growth in vivo. Methods STAT3 shRNA expression vector was stably transfected to SW1990 cells. STAT3 and p-STAT3 protein was examined using Western blot. The growth ability of SW1990 cells in vivo was determined in a subcutaneous tumor model of nude mice. Western blot was performed to detect the protein expression of Bcl-xL and cyclin D1. Results The protein expression of STAT3 and p-STAT3 decreased by 90% and 92% by stable transfection of STAT3 shRNA expressing vectors(P ＜0. 05). Inhibition of STAT3 with RNAi significantly inhibited the growth ability of SW1990 cells in vivo( P ＜ 0. 05 ). The tumor weight significantly decreased( P ＜ 0. 05 ). Moreover, the relative Bcl-xL and cyclinD1 protein expression in SW1990-RNAi cells reduced by 56% and 50% compared with that of the parental SW1990 cells, respectively (P ＜ 0. 05). Conclusions Inhibition of STAT3 with RNAi significantly inhibits the growth ability of pancreatic cancer cells through down-regulating Bcl-xL and cyclin D1.     

结直肠癌肝转移与门静脉血K-ras基因突变的关系

目的 检测结直肠癌患者门静脉血液、原发癌组织及肝转移灶中K-ras基因突变,探讨K-ras突变与结直肠癌肝转移的关系.方法 采用实时荧光定量聚合酶链反应(PCR)技术和基因测序技术检测48例结直肠癌患者门静脉血液、原发肿瘤组织、相应的癌旁肠黏膜以及8例肝转移灶组织中K-ras基因突变.结果 48例结直肠癌组织中17例(35.4%)发现K-ras基因突变,48例癌旁黏膜中4例(8.3%)发现K-ras基因突变,明显低于癌组织的基因突变率(P＜0.05).48例结直肠癌患者中16例(33.3%)门静脉血中发现K-ras基因突变,与癌组织的基因突变率差异无统计学意义(P＞0.05).有肝转移患者门静脉血中K-ras基因突变率(7/10,70.0%)明显高于无肝转移者(9/38,23.7%,P＜0.05).16例门静脉血存在K-ras基因突变者,其相应的肿瘤组织中均发现K-ras突变.而结直肠癌组织中无K-ras基因突变者,患者门静脉血及癌旁黏膜无基因突变.8例同时性肝转移患者中5例门静脉血发现K-ras基因突变,且其相应的肝转移灶组织也发现相同的K-ras突变.2例异时性肝转移患者门静脉血检测到K-ras基因突变,手术时无肝转移,但分别于术后第6个月和第9个月经CT检查证实有肝转移.原发肿瘤组织K-ras基因突变类型与门静脉血、肝脏转移灶的K-ras基因突变一致,即K-ras基因12密码子GGT突变为GAT或GTT.结论 结直肠原发癌组织和患者门静脉血有K-ras基因的突变,预示着肿瘤可能有肝脏转移.

Abstract：

Objective To detect mutations of K-ras oncogene in portal vein blood of patients with colorectal cancer, and to find out the relationship between mutated K-ras oncogene and liver metastases in colorectal cancer. Methods Forty-eight patients with colorectal cancer were screened for the mutations of K-ras oncogene in tissue samples from their tumors, portal vein blood, proximally adjacent mucosa and 8metastatic liver biopsies by real-time fluorescence quantitative polymerase chain reaction (PCR) and DNA sequencing. The results were analyzed with their clinical data. Results Sixteen of the 48 patients with colorectal cancer had K-ras point mutations at codon 12 in their portal vein blood, and 17 of 48 patients had K-ras mutations in their primary tumors, but only 4 of 48 patients had K-ras mutations in proximally adjacent mucosa. There was no significant difference in rate of K-ras mutation between tumor tissues and portal vein blood (P ＞ 0. 05 ), but significant difference was found between the tumor tissue and the proximally adjacent mucosa ( P ＜0. 05 ). The rate of K-ras mutations in portal vein blood of colorectal cancer with liver metastases (70. 0% ) was higher than that of without liver metastases (23.7%). Sixteen cases of mutated K-ras in portal vein blood showed mutations in tumor tissues. Patients without mutated K-ras in tumor tissue had no mutations in their portal vein blood and proximally adjacent mucosa. In 5 of 8 patients with simultaneous liver metastasis, mutated K-ras oncogenes were detected in portal vein blood, and the type of K-ras mutation detected in the tumor tissue was accord with that in metastatic liver biopsies. Two patients with mutated K-ras detected in their portal vein blood had no liver metastases during perioperation, but liver metastases were diagnosed by CT at the postoperative month 6 and 9 respectively. The main types of K-ras mutations at codon 12 included GGT to GAT and GGT to GTT. No one had point mutation at codon 13. Conclusion Mutated K-ras detected in both cancer tissue and portal vein blood may indicate livermetastases from colorectal cancer.     

结直肠腺癌中候选干细胞标记基因Musashi-1和β1-integrin的表达

目的 观察候选干细胞标记基因Musashi-1、β1-integrin在结直肠腺瘤及结直肠腺癌组织中的表达.方法 应用免疫组织化学链霉生物素-过氧化物酶法(SP法),检测结直肠癌组织芯片(8例正常结直肠黏膜,8例腺瘤,69例腺癌,其中8例为黏液腺癌组织)中Musashi-1和β1-integrin蛋白表达,分析其与临床病理特征的关系.结果 结直肠腺癌组织中Musashi-1阳性表达率为66.7%(46/69),腺瘤为50.0%(4/8).结直肠腺瘤和腺癌中β1-integrin阳性表达率分别为37.5%(3/8)和59.2%(41/69)(P＜0.05).腺癌组β1-integrin阳性表达率显著高于腺瘤组(P＜0.05).TNMⅢ期腺癌组Musashi-1和β1-integrin蛋白表达显著高于TNM Ⅰ～Ⅱ期组(P＜0.05).相关分析显示,Musashi-1与β1-integrin呈正相关(rs=0.631,P＜0.01).结论 候选干细胞标记基因Musashi-1、β1-integrin可能在结直肠癌发生、进展中起重要作用.

Abstract：

Objective To investigate the expression of two putative stem cell genes Musashi-1 and β1-integrin in human colorectal carcinomas. Methods Musashi-1 and β1-integrin immunoreactivity was studied immunohistochemically in tissue microarray-based samples containing 69 cases of colorectal adenocarcinomas, 8 cases of normal mucosa, and 8 cases of adenomas. Results Musashi-1 protein expression rate was 66. 7% (46/69) in colorectal adenocarcinomas. The positive rate of βl-integrin protein was59. 2% (41/69) in adenocarcinomas, higher than in the colorectal adenomas tissues (37.5%, 3/8, P ＜0. 05). The expression levels of Musashi-1 and β1-integrin protein were significantly higher in samples of TNM stage Ⅲ than in those of TNM stage Ⅰ -Ⅱ (P ＜0. 05 ). Musashi-1 expression was closely correlated with β1-integrin (r, =0.631 ,P＜0.01). Conclusion Putative intestinal stem cell genes Musashi-1 and β1-integrin may be involved in human colorectal tumor carcinogenesis and progression.     

水通道蛋白1和3在结直肠癌组织中的表达及其意义

Objective To investigate the significance of aquaporin-1 (AQP-1) and aquaporin-3 (AQP -3) in the development of colorectal carcinoma. Methods The expression of AQP-1 and AQP-3 was investigated using immunohistochemical staining with Streptavidin Perdcidase in tissues from colorectal adenoma (CRA, n=25), colorectal cancer (CRC, n=50), and adjacent mucosa (CRT, n=50).Results The positive rate of AQP-1 was 64%(32/50) in CRC, significantly higher than that in CRT (38%, 19/50) and CRA(32%,8/25)(P＜0.05). The expression of AQP-1 was associated with depth of invasion and lymph node metastasis in CRC patients(P＜0.05). The positive rate of AQP-3 was 56% in CRT, 44% in CRA, and 52% in CRC. There were no significant differences(P＞0.05). The expression of AQP-3 was associated with age, tumor diameter, and depth of invasion(P＜0.05). No significant correlation between the expression of AQP-1 and AQP-3 in CRC was shown by Spearman correlation analysis(P＞0.05). Conclusions AQP-1 expression is increased in CRC while the expression of AQP-3 is not. There is no correlation between the expression of AQP-1 and AQP-3 in CRC.     

RNA干扰转录因子激活蛋白4基因表达对结肠癌细胞株SW480的影响

目的观察转录因子激活蛋白4（AP-4）基因对结肠癌细胞株SW480生物学行为的影响。方法设计合成针对AP-4基因外显子7的小分子干扰RNA（siRNA）表达质粒,用脂质体转染SW480细胞,通过RT-PCR技术、Western印迹、四甲基偶氮唑盐实验（MTT法）、流式细胞仪和Transwell体外侵袭实验等检测该siRNA对SW480细胞基因表达、细胞增殖、细胞周期及细胞凋亡能力和浸润转移能力等生物学行为的影响。结果AP-4siRNA转染SW480细胞96h后,其AP-4mRNA水平下降了58%,培养液上清AP-4蛋白浓度下降了75%（P〈0.01）。细胞增殖受到明显抑制,抑制率达61%～78%;流式细胞仪检测结果显示,AP-4siRNA组SW480细胞凋亡率为（21.70±2.51）%,显著高于阴性对照组的（2.31±0.14）%（P〈0.01）,G0-G1期细胞比例增加（P〈0.01）,G2-M期细胞减少（P〈0.05）;Transwell体外侵袭实验显示,AP-4siRNA能明显抑制SW480细胞的体外侵袭力（P〈0.01）。结论应用siRNA技术沉默AP-4基因能有效抑制SW-480细胞AP-4的表达,进而抑制细胞的生长、增殖及诱导细胞的凋亡,为以AP-4为靶向的结肠癌基因治疗提供了新的思路和手段。     

IL-18基因转染大肠癌细胞及对其肿瘤原性改变的研究

目的：建立转染人白细胞介素-18（hIL-18）基因的大肠癌细胞株,并研究IL-18基因转染后SW480细胞肿瘤原性的改变。方法：将携带hIL-18的质粒pcDNA3.1-hIL-18转导入人大肠癌细胞系SW480细胞中,通过药物G-418进行筛选,利用RT-PCR和ELISA法对IL-18的表达进行检测;通过裸鼠致瘤实验观察肿瘤原性的改变。结果：IL-18基因成功转导入SW480细胞中并能顺利表达;RT-PCR电泳结果显示IL-18基因在mRNA水平有表达;ELISA结果显示,106个转染细胞在24 h内分泌IL-18的含量是（145.71±4.42）pg;空载体转染的细胞未检测到hIL-18;生长曲线显示转染hIL-18基因后的细胞生长明显减慢;黏附曲线显示SW480-hIL-18组的黏附率在各个时相点均明显升高,而空载体组和空白对照组之间差异无统计学意义（P〈0.05）。裸鼠致瘤实验表明,接种SW480-hIL-18细胞的裸鼠肿瘤体积明显小于SW480组和SW480-pcDNA3.1组;抗瘤实验结果显示,放射灭活的SW480-pcDNA3.1细胞和SW480-hIL-18细胞免疫接种裸鼠后,再接种SW480细胞于裸鼠左侧背部皮下,SW480-hIL-18细胞免疫接种组肿瘤长出的时间比SW480-pcDNA3.1细胞免疫接种组明显延长,并且肿瘤的生长速度明显低于SW480细胞免疫接种组。结论：hIL-18基因能成功整合到SW480细胞基因组中,并且能在转染的肿瘤细胞中持续表达。hIL-18基因转导后的SW480细胞生长受到抑制,黏附能力增强h,IL-18基因转染降低了SW480细胞的肿瘤原性;hIL-18基因修饰的SW480细胞具有明显的抗肿瘤作用,为大肠癌基因工程肿瘤疫苗的研制提供了实验基础。     

二氢青蒿素联合吉西他宾治疗胰腺癌的实验研究

目的 探讨二氢青蒿素联合吉西他宾治疗胰腺癌的作用及其机制.方法 培养胰腺癌细胞株BxPC-3和Panc-1,通过MTT法检测二氢青蒿素联合吉西他宾对胰腺癌细胞生长的抑制作用;通过Annexin V-FITC/PI染色流式细胞术和激光共聚焦显微镜检测细胞凋亡情况;通过EMSA检测NF-κB与DNA结合活性的改变;通过Western blot法检测细胞中NF-κB/P65和NF-κB下游增殖、凋亡相关蛋白的表达情况.裸鼠皮下注射BxPC-3细胞建立胰腺癌裸鼠移植瘤,监测给药后肿瘤体积的变化,TUNEL染色检测肿瘤细胞凋亡情况.结果 二氢青蒿素联合吉西他宾对BxPC-3和Panc-1两株细胞的增殖抑制率可达(81.1±3.9)%和(76.5±3.3)%;凋亡率可达(53.6±3.8)%和(48.3±4.3)%,与吉西他宾组[(24.8±2.9)%和(21.8±3.5)%]相比,差异有统计学意义(P<0.01).在裸鼠体内,各治疗组均可抑制胰腺癌裸鼠移植瘤的生长;联合组肿瘤的体积和增殖凋亡指数分别为(262±37)mm~3和(50±4)%,与吉西他宾组[(384±56)mm~3和(25±3)%]相比,差异有统计学意义(P<0.05).EMSA和Western blot结果显示,二氢青蒿素能抑制胰腺癌细胞NF-κB与DNA结合活性,联合组较吉西他宾组NF-κB活性有显著的降低;二氢青蒿素下调BxPC-3和Pane-1细胞核P65的表达,联合组较对照组显著下调NF-κB靶基因蛋白Cyclin D1、Bcl-xL、Bel-2的表达,上调Bax的表达,降低Bel-2/Bax的比例,进一步增加Caspase-3的活化.结论 二氢青蒿素抑制吉西他宾所诱导激活的NF-κB的活性,下调NF-κB下游靶基因蛋白的表达可能是其增敏吉西他宾抗胰腺癌作用的分子机制.     

结肠癌SW480细胞FAP-1表达与奥沙利铂化疗耐药关系的研究

目的探讨结肠癌FAP-1表达与其对奥沙利铂化疗耐药间的关系。方法用奥沙利铂处理结肠癌SW480细胞,用MTT法评价其细胞增殖能力,以RT-PCR法评价FAP-1 mRNA表达水平。结果奥沙利铂化疗仅能一定程度上抑制结肠癌SW480的增殖,但随作用时间的延长,SW480细胞仍能继续增殖。经过奥沙利铂化疗FAP-1的表达上调。结论奥沙利铂化疗可引起FAP-1表达的上调,增强肿瘤细胞对抗Fas诱导的细胞凋亡。这可能与结肠癌对奥沙利铂化疗的耐药相关。     

脆性组氨酸三联体基因转染对人结肠癌细胞株SW480奥沙利铂敏感性的影响

目的 观察脆性组氨酸三联体基因(FHIT)转染对人结肠癌细胞株SW480奥沙利铂敏感性的影响.方法 将重组真核表达质粒pRc/CMV2-FHIT通过脂质体转染技术导入人结肠癌细胞株SW480,筛选稳定转染的细胞并扩增培养,以转染了空质粒pRc/CMV2的SW480细胞(SW480-pRc/CMV2)和正常SW480细胞为对照.逆转录-聚合酶链反应(RT-PCR)检测FHIT基因的mRNA转录水平.以奥沙利铂作用于3组细胞,用噻唑蓝(MTT)比色法测定细胞的生长抑制率,用流式细胞仪检测奥沙利铂处理前后各组结肠癌细胞的凋亡率及细胞周期的变化.结果 SW480-FHIT细胞的RT-PCR产物经凝胶电泳有明显的阳性条带,而对照组则无;经奥沙利铂处理后,转染FHIT基因的SW480细胞的凋亡水平与空质粒转染组及结肠癌细胞株组比较明显增高(第2、3、4天A值比较P<0.05),并且FHIT基因与奥沙利铂有轻度的协同促进凋亡作用;同时奥沙利铂处理前后实验组结肠癌细胞的生长周期较对照组均出现了明显的G_0/G_1期阻滞,且细胞的生长抑制率存在浓度和时间依赖性.结论 外源性FHIT基因表达与奥沙利铂协同促进SW480细胞凋亡及细胞周期阻滞,FHIT基因可增加结肠癌细胞对奥沙利铂的敏感性.     

结直肠癌中MEK2/ERK信号传导通路的研究

目的　研究丝裂原激活化蛋白激酶 (MAPK )中MEK2 /ERK信号传导通路在结直肠癌发生发展中的作用。方法　 ( 1)采用Westernblot检测 5 2例结直肠癌组织及其邻近肠黏膜中MEK 2蛋白的表达。 ( 2 )用丝裂原细胞外激酶 (MEK )抑制剂作用于结肠癌细胞系SW 480 ,然后以MTT法检测细胞增殖状态 ;用Westernblot检测MEK2 ,p ERK及其靶基因产物C myc的表达。结果　结直肠癌组织中MEK2蛋白表达水平明显高于邻近的肠黏膜 (P <0 .0 5 ) ,且与肿瘤的分化、Dukes分期及淋巴结转移有关 (P <0 .0 5 )。应用MEK的抑制剂后SW 480细胞中MEK2 ,p ERK ,C myc表达水平随作用时间延长而下降。结论　MEK2活性增高与结直肠癌细胞侵袭力有关 ,阻断MEK2 /ERK信号传导通路可以抑制结肠癌细胞的增殖 ,促进其凋亡。     

重组腺病毒介导的野生型p53基因对结直肠癌细胞的放射治疗增敏作用

目的探讨野生型p53基因通过重组腺病毒转染至结直肠癌细胞后对放射治疗（放疗）的增敏作用。方法将含野生型p53基因的重组腺病毒转染SW480结直肠癌细胞后,采用4、6Gy对其进行放疗。并通过噻唑蓝比色法检测生长抑制率、末端脱氧核苷酸转移酶介导的dUTP缺口末端标记检测细胞凋亡水平、免疫组化检测增殖细胞核抗原的表达。结果经4、6Gy放疗后,转染野生型p53基因的SW480细胞生长受到了明显的抑制（P〈0．05）,凋亡率增加,增殖细胞核抗原比率下降。结论野生型p53基因可增加p53突变的结直肠癌细胞对放射治疗的敏感性。     

RNA干扰PP2A-Aα基因表达对结直肠癌细胞生物学行为的影响

目的 探讨RNA干扰PP2A-Aα基因表达对结直肠癌细胞生物学行为的影响.方法 设计了3条shRNA干扰载体并分别稳定的转染结直肠癌SW480细胞.RT-PCR方法筛选出一组干扰效率最高的转染细胞进行进一步实验.应用MTT法检测干扰后结直肠癌细胞的增殖能力,应用Transwell实验检测干扰后结直肠癌细胞的运动侵袭能力.结果 转染pS-shRNA599干扰载体的SW480细胞PP2A-Aα基因表达明显降低,抑制率达72.8%.应用MTT法检测干扰后结直肠癌细胞的增殖能力明显增强(P<0.01);Transwell实验显示,干扰组细胞的穿膜细胞数明显多于对照组细胞(P<0.01).结论 PP2A-Aα基因表达降低可明显提高结直肠癌SW480细胞的增殖能力与运动侵袭能力,PP2A在结直肠癌细胞中可能扮演着肿瘤抑制剂的角色.     

TLR4、NF-κB和AP-1在乳腺癌中的表达及其与临床病理特征的相关性研究

目的 探讨Toll 样受体4（TLR4）、核因子κB（NF-κB）和激活因子蛋白1（AP-1）在乳腺癌组织中的表达及其与临床病理参数的关系.方法 采用免疫组织化学方法 检测106 例乳腺癌组织中TLR4、NF-κB 和AP-1 的表达.分析三者与乳腺癌临床病理因素的关系,以及TLR4与NF-κB、AP-1 的相关性.结果 随着乳腺癌患者T 分期、N 分期、M 分期和临床分期的增加,乳腺癌组织TLR4、NF-κB 及AP-1 的表达均升高（P 均〈 0.05）.随着乳腺癌组织分化程度的降低,NF-κB 的表达升高（P 〈 0.05）.乳腺癌组织中TLR4 和AP-1 的表达呈正相关（P 〈 0.05）.结论 乳腺癌组织TLR4 高表达,激活AP-1 信号通路,促进癌细胞的增殖、浸润及转移,进而影响患者的预后.     

紫草素下调CXCR4表达及抑制结肠癌细胞株SW480在CXCL12诱导下的定向迁移

目的探讨紫草素对结肠癌细胞增殖、CXCR4表达及对CXCL12诱导的定向迁移能力的影响。方法采用MTT法观察紫草素对SW480细胞增殖的影响,流式细胞仪检测紫草素对SW480细胞表面CXCR4表达的影响．Transwell方法观察紫草素对SW480细胞定向迁移能力的影响。结果紫草素对SW480细胞生长有抑制作用．这种抑制作用随着药物浓度的升高和作用时间的延长而增强。SW480细胞CXCR4阳性表达率为（99．1±0．7）％,用紫草素0.01、0．1及1．0μmol／L作用24h后,CXCR4阳性表达率分别降至（76．0±2．4）％、（59．1±2．5）％和（35．5±1．9）％（F=1098．041．P〈0．001）。上述不同浓度紫草素对CXCL12诱导的SW480迁移抑制率分别为25．2％、38．5％和55．7％（F=48．970,P〈0．001）。结论紫草素除了抑制结肠癌细胞增殖外,还可能通过下调CXCR4表达从而抑制肿瘤细胞在CXCL12诱导下的定向迁移。