节点文献
直肠癌术前分期的超声影像学及其与TrkB,D2-40表达的研究
Preoperative Staging of Rectal Cancer Ultrasound Imaging and Its Expression on TrkB and D2-40
【作者】 于英蛟;
【导师】 王学梅;
【作者基本信息】 中国医科大学 , 影像医学与核医学, 2010, 博士
【摘要】 前言直肠癌为常见的恶性肿瘤之一,其发病率和死亡率呈上升的趋势。近几十年来,外科手术、放射治疗、和肿瘤学治疗都有了很大的进展。直肠癌的预后主要依赖于选择有效的治疗方案。选择正确治疗方案的前提是术前了解病人的临床病理分期,包括对肿瘤的检查,判断肠系膜脂肪和直肠系膜筋膜有否浸润以及有无结节浸润和远处转移。各种影像学检查都起到了重要的作用,CT在T分期的准确度仅达33—77%,对淋巴结转移的准确度为53%。MRI在T分期总的准确性是86%,淋巴结转移的总准确性为67.6%。经直肠二维超声对T分期的总准确性为65%,对淋巴结转移诊断的准确性仅为57-71%。由此可见,超声对于直肠癌术前分期诊断较其它影像学方法未见明显优势。近年来,血管新生受到广泛关注。研究表明血管新生在肿瘤进展和转移中非常重要。很多研究证实肿瘤血管生成是直肠癌预后的重要因素。因此,评价新生血管对直肠癌患者是非常重要的。彩色多普勒超声(Color Doppler Flow Imaging, CDFI)及能量多普勒超声(Color Doppler Energy, CDE)参数可以反映血流动力学状态,血管指数(vascularity index, VI)是在CDE状态下计算肿瘤断面内彩色像素数与总像素数的比值。三维能量多普勒超声(Three-dimensional color power Angiography,3D-CPA)是一种非损伤性评价脏器血流灌注状态的方法,可以清楚地显示肿瘤内的低速血流及血管构建和分布的变化,并可做定量分析。另外,超声造影是目前超声界研究的热点,可以显示毛细血管和其它微血管的血流,已应用于肝脏局造性病变的定性诊断,在甲状腺、乳腺、子宫等部位的占位性病变的定性诊断中也有研究,但在直肠癌方面的研究未见报道。本研究探讨彩色及能量多普勒超声及3D-CPA和超声造影对直肠癌血管生成的评估价值及对直肠癌术前分期的价值。直肠癌病人的预后主要与一些能够调控肿瘤细胞增殖、凋亡和侵袭能力的基因有关。TrkB是酪氨酸激酶受体,是脑源性神经营养因子(BDNF)的特异性受体。研究表明TrkB通过促进瘤内新血管生成,以及神经营养作用,支持肿瘤的生成。TrkB在多种恶性肿瘤中过表达,对促进肿瘤转移起到重要作用。但TrkB在直肠癌中的表达及作用国内外尚无报道。本研究探讨TrkB在直肠癌中有否表达,及其是否与病理分期相关。方法论文一1、二维模式及CDFI、CDE模式观察直肠及肿物的部位、形态、大小、内部回声及周围浸润范围。启动彩色多普勒超声检查,观察癌肿的血流。检测肿瘤内部的血流频谱,记录收缩期峰值流速(PSV)和阻力指数(RI)。启动CDE模式,在不同切面上冻结五次图像,选择显示最多血流信号的切面,存储图像。将CDE图像输入计算机,并用计算机图像软件分析获取血管数目定量参数即血管指数(Ⅵ)。2、三维成像CPA模式下,进行直肠癌肿块的3D-CPA成像,显示肿块血管的立体走行及分支。用半定量方法将肿物内血流分级,采用Qlab软件GI3DQ工具测得直肠癌的体积,计算血管条数,计算血管指数Ⅵ。3、超声造影检查。在双幅造影模式下进行超声造影检查。实时观察直肠癌的造影增强情况及动态变化过程,储存造影检查过程的图像资料。最后进行图像分析,回顾造影过程的图像,观察直肠癌病变的增强时间、增强水平、增强模式及其变化。开启Qlab分析软件,启动感兴趣区(ROI)定量程序,获得感兴趣区血流灌注的时间-强度曲线。启动微血管成像(microvascular imaging,MVI)程序,实时观察造影剂微泡在微血管中的显像轨迹。4、所有病例均采用国际抗癌联盟TNM分期标准进行分期,收集术后病理分期资料。超声所得各项参数与TNM分期比较。5、统计方法利用SPSS13.0软件进行统计学处理。PSV、RI、VI与TNM分期比较用有序分组资料的线性趋势检验。3D-CPA血管计数与直肠癌术后病理分期的比较,Pearson Chi -Square x2检验。3D-CPA定量资料血管指数与术后病理分期比较用两独立样本t检验。P<0.05为检验水准。论文二1、90例直肠癌组织蜡块均来自中国医科大学附属第一医院,其中50例由病理科查得,40例用肿瘤外科标本自行制备。甲醛固定石蜡包埋肿瘤组织切片常规HE染色。2、Western blot方法:冰冻组织(包括癌和癌旁)和细胞用冰冷PBS洗两次,在裂解缓冲液(包括20 mM Tris-HC1,1 mMEDTA,50 mM NaCl,50 mM NaF, 1 mM Na3V04,1% Triton X-100 and 1 mM phenylmethanesulfonyl fluoride (PMSF))中洗两次。在4℃条件下匀浆,22000g离心30分钟。收集上清液,蛋白含量测定用BCA法。上样总蛋白量80微克,6%SDS-PAGE电泳后转移至PVDF膜;5%脱脂奶粉封闭,兔抗人TrkB (1:200)和β-actin(1:200)(均购自Santa Cruz美国)4℃孵育过夜。山羊抗兔IgG(1:2000)37℃孵育2小时,最后条带显现用ECL发光(中国南京吉凯公司)。DNR成像系统采集图像,Image J软件用于半定量分析特异性条带的灰度值。3、免疫组化方法:90张直肠癌组织切片常规脱蜡并水化。0.1mol/LTris-HCL(PH10.0)缓冲液,高温高压修复抗原2.0min;3%H202和5%山羊血清37℃下分别孵育切片1h;兔抗人TrkB(1:100)和鼠单克隆抗体D2-40(中山)4℃孵育过夜;二抗和SP复合物37℃分别孵育切片30min;最后DAB显色(DAB kit,福州迈新生物技术公司),苏木素复染细胞核。同时设立阳性和阴性对照。至少5个高倍视野下(400X)评价TrkB染色程度(1=弱,2=强)和阳性肿瘤细胞百分比(0%=阴性,1-50%=1,51-75%=2,≥76%=3)。将上述两项评分的乘积作为每个标本染色的最终评分,每个样本的最终得分0,1,2,3,4,6,最后确定直肠癌标本的染色情况分别为阴性:评分0分,低表达:评分≤3分,高表达:评分>3分。D2-40免疫染色显示淋巴管,低倍镜下随机选择五个视野取淋巴管计数的平均值。4、MTT法:MTT试验用来评价转染细胞的增殖情况。将细胞消化下来接种到5个96孔板(1X103/200 u L)转染24小时,每天检测前每个孔加入20ulMTT溶液(5mg/ml,即0.5%MTT),4h后,终止培养,小心吸去孔内培养液,每孔加入150ul DMSO,置摇床上振荡10min,测量光密度。按时间(X轴)和平均光密度(Y轴)绘制生长曲线。试验重复三次。5、细胞凋亡试验:细胞凋亡用AnnexinV-FITC凋亡检测试剂盒通过流式细胞仪检测,操作按说明书进行。细胞在冰冷的PBS中洗两次,在1x结合缓冲液中重悬(1x106/ml)。100微升细胞悬液(1x105cell)轻轻混合5微升AnnexinV-FITC和5微升PI,避光室温下孵育15分钟。再加入400微升1x结合缓冲液后,用流式细胞仪检测细胞凋亡。试验重复三次。6、细胞侵袭试验:细胞侵袭试验用24孔Transwell小室。Matrigel 1:8稀释液包被Transwell小室底部膜的上室面,将转染24小时后的细胞消化下来(1x104)并且接种到Transwell上室,再培养24小时。Transwell下室加入15%FBS使细胞向下室迁移。用棉签擦掉上面膜表面没有迁移过去的细胞,迁移过去到达膜下表面的细胞用多聚甲醛固定,用苏木素染色。400X显微镜随机选取五个视野计数迁移细胞数。试验重复三次。7、统计分析:用SPSS13.0软件完成数据分析。癌及癌旁TrkB表达水平的比较用非参数检验。TrkB表达和临床病例特征之间的关系用Binary Logistic regression分析,TrkB高表达和低表达组织之间LVD的差异用独立样本t检验,各种处理后细胞之间比较用One way ANOVA。所有数据用mean±SD表示,P<0.05认为有统计意义。结果论文一1、Ⅵ与TNM分期之间有相关关系(P=0.001,r=0.476)2、Ⅰ期、Ⅱ期直肠癌血流较丰富,肿物周边均可探及血管,多数内部可探及血管,以Ⅱ级血流为主,Ⅲ期、Ⅳ期直肠癌周边及内部均可探及血管,以Ⅲ级血流为主,呈丰富的血管树,分支复杂,血管走行迂曲不规则。经x2检验,Ⅰ期、Ⅱ期和Ⅲ期、Ⅳ期之间血管分级不同,有统计学差异(P<0.05)3、注射造影剂后,各期直肠癌的增强表现为造影剂快速填充整个肿瘤,声像图显示肿瘤在整个范围内迅速弥漫性增强,与周围正常组织的回声差异明显,可清晰显示病灶的范围、边界。晚期部分病灶呈等增强;部分病灶内部呈低增强,周边呈稍高增强,可进一步显示病灶的浸润范围。由ROI定量分析软件划定感兴趣区域后自动生成时间-强度曲线,Ⅲ期、Ⅳ期直肠癌曲线图显示上升支陡直,下降支平缓。论文二1、Western blot结果用Western blot分析30个病例的癌及癌旁的TrkB表达。26例癌中TrkB表达较癌旁增高(P=0.000)2、免疫组化结果74例直肠癌组织中发现了TrkB表达(82.2%)。65例(72.2%)为高表达(评分4分或6分),25例(27.8%)为低表达(评分0,1,2,3),统计学分析TrkB表达与临床病理特征的关系,表明TrkB高表达与肿瘤的大小(T≥5cm,T<5cm,P=0.407)和分化(高分化与中低分化比较,P=0.867)没有统计学差异。但是,免疫组化表现TrkB高表达与淋巴结转移有统计学差异(P=0.035)。高表达同时与高分期直肠癌相关(Ⅰ+Ⅱ与Ⅲ比较,P=0.035)。淋巴管密度在有淋巴结转移组和无淋巴结转移组中分别为169.0±29.1和125.7±37.5。TrkB高表达的肿瘤中出现较多淋巴管(P=0.000)。3、TrkB-siRNA结果TrkB-siRNA抑制细胞增殖:TrkB-siRNA转染后5天时,TrkB-siRNA组,non-silencing siRNA组,对照组的光密度分别为1.41±0.09,1.58±0.02,1.55±0.06(P=0.035).从增殖曲线上看,TrkB-siRNA细胞较未转染组和对照组增殖抑制。TrkB-siRNA促进细胞凋亡:TrkB-siRNA转染的LOVO细胞,non-silencing LOVO细胞和对照组相比,凋亡率分别为26.5±1.9%,8.1±0.5%,5.4±1.2%,(P=0.000).TrkB-siRNA细胞侵袭能力降低:TrkB-siRNA转染细胞TrkB的表达水平明显比non-silencing siRNA细胞和对照组少。TrkB-siRNA转染细胞,non-silencingsiRNA细胞,对照组的发生侵袭的细胞数量分别为16.2±3.9,26.4±3.2和25.9±3.3,(P=0.020).结论1、能量多普勒所检测的单位面积内的血管数量与直肠癌病理分期呈直线正相关,随病理分期增高,单位面积内血管数量增加。经直肠3D-CPA检测直肠癌肿块血流分级和单位体积内的血管条数在Ⅲ期、Ⅳ期显著高于Ⅰ期、Ⅱ期,可作为直肠癌术前分期超声诊断的参考。应用超声造影技术可以清晰显示直肠癌毛细血管水平的血流灌注,直观反映病灶局部微循环状况。直肠癌超声造影具有典型的声像图表现,为直肠癌术前分期诊断提供更加丰富的信息。2. TrkB过表达在直肠癌中普遍存在,这表明TrkB在直肠癌肿瘤生成中可能起到一些作用。TrkB过表达与肿瘤转移能力有关,可能是通过新生淋巴管的作用。用TrkB-siRNA干扰TrkB表达后,LOVO细胞凋亡扩大,增殖和侵袭力减少。
【Abstract】 IntroductionColon cancer is the third most common cancer worldwide, and the incidence of colon cancer is increasing. Numerous improvements in the surgical, radiologic, and oncologic treatment have been made over the past two ecades. Its prognosis mainly depends on choosing the most effective treatment. Prerequisites for this treatment option include accurate preoperative tumor staging with regard to tumor detection, mesorectal fat infiltration, mesorectal fascia status, nodal involvement and distal metastatic disease. A variety of imaging studies have played an important role.Staging accuracy for CT ranges from 33%to 77%for T-stage accuracy and 53% for N-stage accuracy. MRI has shown improved T-stage accuracy, with rates of 86% and 67%on N-stage. TRUS has shown T-stage accuracy 65%and N-stage accuracy ranging from 57%to71%. Therefore,we can’t find any dominance on ultrasonography in rectal cancer.Angiogenesis has gained much attention in recent years. It has been shown to be an essential event for tumor growth and metastases. Several studies have demonstrated that tumoral angiogenesis is an independent prognostic factor in rectal cancer. Therefore, the assessment of this factor would seem to be important when evaluating patients with cancer of rectal.Color Doppler Flow Imaging(CDFI) and Color Doppler Energy(CDE) ultrasonography may reflect dynamics of bloodstream, "Vascular index (VI) is under the CDE calculating the ratio of the number of color pixel to the total number of pixels within the tumor section. Three-dimensional power Doppler ultrasound (3D-CPA) is a non-invasive evaluation of visceral perfusion of the method, which can clearly show low tumor blood flow and blood vessels within the construction and distribution of changes, and can do quantitative analysis. In addition, ultrasound is the research focus,it can show blood flow in capillaries and other microvessels, has been applied to diagnosis of focal lesions in the liver, and in the thyroid, breast, uterus and other parts of the qualitative lesions there are also diagnostic study, the research in recal cancer has not been reported. This study is designed to investigate the value of vascular and stage in rectal cancer by CDFI、CDE、3D-CPA and contrast-enhance ultrasonography.The prognosis of patients with colon cancer principally correlates with the proliferative, apoptotic and invasive potentials of tumor cells, which is regulated by some critical genes. Tropomysin-related kinase B (TrkB) is a member of Trk family, functions as a receptor tyrosine kinase, which is necessary for the normal evelopment of nervous system. Recent studies have been initiated to show the suppression of anoikis and induction of metastasis by TrkB. TrkB is up-regulated in various primary human tumors. Therefore, the overexpression of TrkB might play an important role in the progression of malignant tumors. However despite that point mutation was observed in colorectal cancer, whether TrkB positively participates in primary colon cancer has not yet been determined. This study is designed to investigate the expression and clinical significance of TrkB in surgically resected colon cancer with different clinicopathological features.MethodsPart one1. Two-dimensional model and CDFI, CDE modeRectum and the tumor’s location, shape, size, internal echo and around the infiltration area was observed. CDFI was started to observe the tumor blood flow. Detection of tumor blood flow within the spectrum, recorded peak systolic velocity (PSV) and resistance index (RI). Start CDE mode, the frozen section in five different images, select the most blood flow signal aspect display, storage image. CDE image will be input into the computer, and computer image analysis software to obtain the number of quantitative parameters of the blood vessel vascular index (VI).2.Three-dimensional imagingCPA mode for 3D-CPA rectal tumor imaging, shows three-dimensional tumor blood vessels course and branches, semi-quantitative method to tumor blood flow grading, Qlab software GI3DQ tool measured the volume of cancer, calculated vascular strips, calculating vascular index VI.3. Contrast-enhance ultrasound.In dual-rate contrast-enhance imaging mode ultrasound imaging. Real-time observation of colorectal cancer cases and contrast-enhanced dynamic process, store the image data imaging process. Finally, image analysis, review the process of image contrast, increased observation time of rectal lesions, and enhance the level and changes in enhanced mode. Open QLAB analysis software, start the region of interest (ROI) quantitative procedures, access to regions of interest perfusion time-intensity curves. Start microvascular imaging (MVI) process, real-time observation of contrast agent microbubbles in the capillaries in the imaging path.4. All patients with International Union Against Cancer TNM staging system for staging, pathological staging data collection. The parameters derived from ultrasound compared with TNM staging.5. SPSS13.0 software used for statistical analysis.PSV, RI, VI compared with the TNM stage grouping data using the ordered linear trend test.3D-CPA vessel count and pathological staging rectal cancer comparison, Pearson Chi-Squareχ2 test. Quantitative information on 3D-CPA vascular index compared with pathological staging using two independent samples t test.Results were considered statistically significant when the p-value was less than 0.05.Part two1. Tissue samples and patients:90 cases of rectal tissue from the paraffin blocks were the First Affiliated Hospital of China Medical University, of which 50 cases were from the pathology investigation,40 cases of surgical specimens of tumor preparation on their own.Formalin-fixed paraffin-embedded tumor tissue sections of conventional HE staining. All of the included patients underwent surgical resection without having chemotherapy or radiation therapy. Formalin-fixed paraffin-embedded sections of tumor were stained with hematoxylin and eosin (H&E) routinely,2. Western blot.:Frozen tissues (including tumor and non-tumorous portion) or cells were washed twice with ice-cold PBS, homogenized on ice in lysis buffer containing 20mM Tris-HCl, 1mM EDTA,50mM NaCl,50mM NaF, 1mM Na3VO4, 1%Triton-X100 and 1mM PMSF. The homogenate was centrifuged at 15000 rpm for 30 min at 4℃The supernatant was extracted and protein content was determined by the BCA assay (Pierce).80μg of total protein was separated by 6%SDS-PAGE and then transferred to PVDF membranes. After blocking with 5%BSA, primary antibodies were incubated on the membranes for TrkB (sc-8316,1:200) and p-actin (1:200) (both from Santa Cruz) overnight at 4℃. The membranes were then incubated for 2 h at 37℃with goat anti-rabbit IgG(1:2000) (ZhongShan, China). Immunoreactive straps were identified using the ECL system (KaiJi,China), as directed by the manufacturer. The DNR Imaging System was used to catch up the specific bands, and the optical density of each band was measured using the Image J software. The ratio between the optical density of TrkB andβ-actin of the same sample was calculated as relative content and expressed graphically.3.Immunohistochemistry:90 paraffin sections of colon tumor were deparaffinized and rehydrated routinely. The antigen recovery was performed by heating slides in an autoclave sterilizer for 2 min in 0.1 mol/L Tris-HCl buffer at pH10. The sections were incubated overnight with primary rabbit polyclonal antibody detecting TrkB (sc-8316,1:100) and mouse monoclonal antibody for D2-40 (ZhongShan, China), following 3%H2O2 and 5%rabbit serum treatment at 37℃for 1h. After which they were incubated with second antibody and SP complex for 30 min (SP kit), and visualized with DAB (DAB kit)(both from MaiXin, China). Negative controls were non-immune rabbit IgG at the same dilution as for the primary antibody.4.MTT assay: The MTT assay was applied to evaluate the proliferation of cells transfected. Cells were detached and seeded in 5 96-well plates (1×103/200μl) in parallel, and transfected for 24h before detection. During the following 5d, the optical density in one indicated plate was examined and cells in other plates were cultured continuously. Everyday,20μl MTT (5mg/ml) was added in each well,4h later the liquids were removed and 150μl DMSO was added. After 10min in vortex, the optical density was measured. The cell growth curves were drawn according to time (X-axis) and average optical density (Y-axis). Data presented are representative of three individual wells.5.Cell apoptosis assay:The cell apoptosis was examined by flow cytometry using an Annexin V-FITC apoptosis detection kit (BD), following the manufacturer’s protocol. Cells were washed twice in ice-cold PBS and resuspended in 1×binding buffer (1×106/ml). Cells of 100μl (1×105) were gently mixed with 5μl Annexin V-FITC and 5μl PI, and then incubated for 15min at room temperature away from light. After supplemented another 400μl 1×binding buffer, cell apoptosis was detected in flow cytometer. Results are representative of three individual experiments.6.Cell invasion assay:The cell invasion assay was performed using a 24-well Transwell chamber (Costar). At 24h following transfection, cells (1×104) were detached and seeded in the upper chamber of a 8μm pore size insert precoated with Matrigel (BD) and cultured for another 24h. Cells were allowed to migrate towards medium containing 15% FBS in the bottom chamber. The non-migratory cells on the upper membrane surface were removed with a cotton tip, and the migratory cells attached to the lower membrane surface were fixed with 4% paraformaldehyde and stained with hematoxylin. The number of migrated cells was counted in 5 randomly selected 400×power fields under microscope. Data presented are representative of three individual wells. 7. The SPSS 13.0 software was applied to complete data processing. "Two-independent samples of nonparametric test" was used to assess the levels of TrkB in colon tumors and non-tumorous counterparts. "Binary logistic regression" analysis was applied to analyze the correlations between TrkB expression and clinicopathological characteristics, and "Independent samples t-test" was used to compare LVD between groups of higher and lower TrkB for the results of immunohistochemistry. One-way ANOVA was used to compare the differences between cells with various treatments. All data were represented as mean±SD and results were considered statistically significant when the p-value was less than 0.05.ResultsPart one1. There is significant relationship between VI and TNM stage in rectal cancer. (P=0.001, r=0.476)2.Stage I and II, the rich blood of cancer, tumor blood vessels could be found around most of the internal probe and may be blood vessels, blood flow to the main grade II, III period, IV of rectal cancer may be peripheral and internal Exploration and blood vessels, mainly to grade III, showing the rich vascular tree, branch complex, tortuous irregular vessels Traveling. I, II, and III, IV grade of difference between the blood vessels, were significantly different (P<0.05)3. After the use of contrast agents, blood signal enhanced significantly around and inside the rectal tumour quickly. We can see the borden of the tumor clearly.The inner part exhibited earlier washout than that of the consecutive colon in the later phase,while the peripheral area still remaind hyperenhancement.The extension and border line could be determined clearly.Shape of the curve in stageⅢand IVrectal cancer was characterized as ascend rapidly and drop slowly than that of stage I andⅡ. Part two1. Western blot analysis was used to evaluate TrkB expression in 30 colon tumors and non-tumorous tissues distant from the primary tumor of the same case. The overexpression of TrkB was found in 26 tumorous samples in comparison with the non-tumorous counterparts (p=0.000).2.TrkB expression in 90 cases of colon cancer by immunohistochemistry. TrkB immunoreactivity was detected in 74 (82.2%) colon tumors. We considered that 65 tumors(72.2%) were higher expression (scores of 4 or 6) and 25 cases (27.8%) were lower expression (scores of 0,1,2, or 3), as described in Materials and methods. Clinicopathological correlations of TrkB expression revealed by immunohistochemistry were then analyzed statistically. No statistical differences were found between the higher TrkB expression and the characteristics of tumor size(T≥5cm versus T<5cm, p=0.407), as well as differentiation (well versus poor-moderate, p=0.867).However, immunostaining showed a statistically significant correlation between higher TrkB expression and lymph node metastasis at the time of resection (p=0.035).LVD in positive and negative node group were 169.0±29.1 and 125.7±37.5, respectively. More lymphatic vessels were present in tumors with higher TrkB expression (p=0.000).3.5 days after TrkB-siRNA transfection, the O.D. of LoVo cells in TrkB, non-silencing and control group were 1.41±0.09,1.58±0.02 and 1.55±0.06, respectively (p=0.035). From the proliferative curves we observed that cells of TrkB-siRNA group exhibited less tendency to proliferation during the 5 days examined compared with non-silencing and control group.4.The apoptotic rates of LoVo cells in TrkB-siRNA, non-silencing and control group were 26.5±1.9%,8.1±0.5%and 5.4±1.2%, respectively (p=0.000,).5.TrkB-siRNA transfected cells exhibited extremely diminished TrkB in comparison to those non-silencing and control cells. The numbers of invasive cells in TrkB-siRNA, non-silencing and control group were 16.2±3.9,26.4±3.2 and 25.9±3.3, respectively (p=0.020).Conclusions1. The number of vessels detected on CDE within the unit area is linear correlation with pathological stage in rectal cancer, more number of vessels per unit area with increased staging. Transrectal 3D-CPA classification and detection of colorectal tumor blood vessels per unit volume within the article number in stage III and IV were significantly higher than those of stage I and II, that can be used as preoperative staging of rectal ultrasound for the diagnosis. Ultrasound imaging can clearly show the level of rectal capillary blood perfusion and microcirculation lesion directly reflect the situation. Rectal ultrasound sonography typical for the preoperative staging of rectal cancer to provide more information.2. Overexpression of TrkB was common in rectal cancer. The increased expression of TrkB was correlated with higher metastatic facility, possibly by lymphoangiogenesis. The augmented apoptosis, attenuated proliferation and invasion of LoVo cells were also observed by the interruption of TrkB expression using specific siRNA. Taken together, TrkB may provide a helpful target for inhibitory therapies of progression in colon cancer.
【Key words】 TNM staging; Rectal Neoplasm; Doppler; Transrectal ultrasonography(TRUS); Three-dimensional ultrasonography; contrast-enhanced sonography; TrkB; LVD; colon cancer; metastasis; proliferation; apoptosis; invasion;