【作者】 李超；

【导师】 彭志海；

【作者基本信息】 上海交通大学 ， 外科学（专业学位）， 2016， 硕士

【摘要】 目的:结肠癌患病率在恶性肿瘤中排第三位,每年全球有超过50万人死于结肠癌疾病,其中90%的病人死于肿瘤的转移。目前肿瘤转移的具体机制仍然尚未阐明,寻找肿瘤转移标志物对于肿瘤的治疗和预后评估具有重要意义。PAK7被发现在多种肿瘤中表达明显增高,本实验对PAK7在结肠癌中的表达及其在结肠癌进展和预后中的作用进行研究。方法:1、通过qPCR和Western blot方法检测40例结肠癌标本中PAK7的表达水平。免疫组化检测含有66例淋巴结转移的203例组织芯片中PAK7的蛋白水平,分析了PAK7的表达与临床病例特征及病人预后之间的关系。2、通过慢病毒载体构建稳定表达下调的Lo Vo、HT29细胞系。3、通过Western Blot和共聚焦实验检测PAK7和EMT重要标志物的表达。4、通过体内外实验,验证PAK7对结肠癌发生、发展及预后的影响。结果:1、PAK7在结肠癌中表达明显增高,并且与肿瘤分期、淋巴结转移、远处转移显著相关。PAK7高表达患者的总体生存率(OS)和无转移生存率(MFS)明显低于低表达患者,Cox比例风险回归分析模型多因素分析表明PAK7高表达可能是结肠癌的独立影响因素,可作为判断预后的指标。2、低表达PAK7的Lo Vo和HT29细胞系中,EMT标志物E-cadherin表达显著上调,而N-cadherin,Vimentin的表达则明显下调。3、体内外实验表明PAK7表达降低,能够抑制结肠癌细胞的侵袭和转移能力。结论:PAK7的异常表达对结肠癌的发生发展及病人预后具有重要作用,并通过诱导结肠癌细胞EMT影响结肠癌的转移和侵袭能力,因此PAK7可以作为评估结肠癌转移和预后的新指标,为结肠癌的治疗提供新的方向。更多还原

【Abstract】 Objects As the third most fatal malignancy,colon cancer is responsible for more than half a million deaths worldwide each year.About 90%of these deaths are caused by metastatic disease.At present,the specific mechanism of metastasis has not yet been clarified.It is important to search for metastasis marker for treatment and prognosis evaluation.P21 protein(Cdc42/Rac)-activated kinase 7(PAK7)has been reported in several tumors.This study investigated the expression of PAK7 and its role in the progression and prognosis of colon cancer.Methods 1.Quantitative Real–time PCR(qPCR)and western blot were used to detect the expression level of PAK7 in human colon cancer.PAK7 expression in a tissue microarray of tumor and matched normal colonic mucosa from 203 colon cancer including 66 lymph node metastasis specimens were tested by immunohistochemistry.Through univariate and Kaplan-Meier analysis,we detect the relationship between the expression of PAK7 and clinicopathological features.2.Construct stable overexpression of PAK7 colon cancer cell line RKO and stability interfere with PAK7 colon cancer cell line Lo Vo and HT29 with lentiviral vector.3.Western bolt and Immunofluorescence staining detects the expression of PAK7 and EMT markers in colon cancer cell lines.4.The effects of PAK7 expression on the tumorigenesis and progression are analyzed in vitro and vivo.Results 1.PAK7 expression is much higher in colon cancer tissue and increased PAK7 expression was significantly correlated with depth of tumor invasion,LNM,distant metastasis,histologic grade.Patients with PAK7-positive tumors have a significantly lower 5-year overall survival than those with PAK7-negtive tumors.In multivariate analysis,the expression of PAK7 is an independent prognostic marker to predict parents’outcome.2.Down-regulated expression of PAK7 in LOVO and HT29 cells significantly decreases the levels of vimentin and N-cadherin but increases E-cadherin expression in protein level.However,overexpression of PAK7 does the opposite.3.Knockdown of PAK7 expression significantly suppresses the invasion and migration of colon cancer cell lines both in vitro and in vivo.Conclusions The abnormal expression of PAK7 plays an important role in the development of colon cancer and the prognosis of the patients,and it affects the metastasis and invasion of colon cancer by regulating the EMT process.Thus,the assessment of PAK7 expression might be helpful in predicting metastasis and prognostication for patients with colon cancer,and be expected to be a potential therapeutic target for colon cancer.更多还原