Gut peptide receptor expression in human pancreatic cancers

OBJECTIVE: To determine the prevalence of gastrointestinal (GI) peptide receptor expression in pancreatic cancers, and to further assess signaling mechanisms regulating neurotensin (NT)-mediated pancreatic cancer growth. SUMMARY BACKGROUND DATA: Pancreatic cancer remains one of the leading causes of GI cancer death; novel strategies for the early detection and treatment of these cancers is required. Previously, the authors have shown that NT, an important GI hormone, stimulates the proliferation of an NT receptor (NTR)-positive pancreatic cancer. METHODS: A total of 26 human pancreatic adenocarcinomas, obtained after resection, and 5 pancreatic cancer xenografts were analyzed for expression of NTR, vasoactive intestinal peptide receptor (VIPR), substance P receptor (SPR), and gastrin-releasing peptide receptor (GRPR). In addition, NTR expression, [Ca2+]i mobilization, and growth in response to NT was determined in L3.6, a metastatic pancreatic cancer cell line. RESULTS: Neurotensin receptor was expressed in 88% of the surgical specimens examined and all five of the pancreatic cancer xenografts. In contrast, VIPR, SPR, and GRPR expression was detected in 31%, 27%, and 8% of pancreatic cancers examined, respectively. Expression of NTR, functionally coupled to the Ca2+ signaling pathway, was identified in L3.6 cells; treatment with NT (10 micromol/L) stimulated proliferation of these cells. CONCLUSIONS: The authors demonstrated NTR expression in most of the pancreatic adenocarcinomas examined. In contrast, VIPR, SPR, and GRPR expression was detected in fewer of the pancreatic cancers. The expression of NTR and other peptide receptors suggests the potential role of endocrine manipulation in the treatment of these cancers. Further, the presence of GI receptors may provide for targeted chemotherapy or radiation therapy or in vivo scintigraphy for early detection.     

趋化因子受体CXCR4在结肠直肠癌中的表达及意义

目的：研究趋化因子受体CXCR4在结肠直肠癌中的表达及其临床意义。方法：采用RT-PCR法检测8种结肠直肠癌细胞株中CXCR4mRNA表达,应用蛋白印迹法检测细胞株中CXCR4蛋白表达。应用免疫组化染色法、结合组织芯片检测正常结肠直肠黏膜组织54例、结肠直肠癌组织49例中之CXCR4蛋白表达情况,并探讨其与结肠直肠癌临床病理特征的关系。结果：在8种结肠直肠癌细胞株中,CXCR4基因在HT29中表达水平最高。COL0205及SW480次之,HCTll6最低。CXCR4蛋白在结肠直肠癌组织中的表达高于结肠直肠正常黏膜组织,差异具有统计学意义（P=0．000）;在伴发转移的结肠直肠癌组织中,其表达比未发生转移者增强,差异具有统计学意义（P=0．024）。结论：CXCR4表达与结肠直肠癌转移存在密切关系,可能成为结肠直肠癌转移潜在治疗靶点。     

无血清培养人结肠癌球囊样细胞生物学特性研究

目的 采用无血清培养方法从人结肠癌细胞株中分选出富含肿瘤干细胞的球囊样细胞,并分析其增殖和迁移特性.方法 人结肠癌细胞株HCT116、HT29细胞在特殊配制的无血清培养基(SFM)中悬浮培养,观察球囊样细胞的生成.流式细胞仪检测结肠癌干细胞分子标记CD133表达,利用CCK-8比色法以及Transwell小室法研究结肠癌球囊样细胞的增殖情况和迁移能力.采用成组设计资料的t检验分析检测数据.结果 HCT116、HT29细胞在SFM培养条件下可以获得可稳定传代的球囊样细胞,SFM培养下HCT116球囊样细胞CD133阳性细胞占75.44％±11.41％,HT29球囊样细胞CD133阳性细胞占76.22％±14.23％.与常规含血清培养基(SSM)培养的同系细胞比较,HCT116及HT29球囊样细胞中结肠癌干细胞分子标记CD133阳性细胞数明显增多(t=11.43,9.17,P＜0.05),其持续增殖能力和运动迁移能力均增强.结论 无血清培养获得的结肠癌球囊样细胞高表达结肠癌干细胞分子标记CD133,且具有更强的增殖和迁移能力.它可作为进一步研究结肠癌干细胞的良好模型.     

Fetal and neoplastic expression of the neurotensin gene in the human colon.

OBJECTIVE: The authors identified various colon cancers that express the gene for the gut peptide neurotensin (NT/N). In addition, the authors sought to delineate the temporal pattern of NT/N gene expression in the human fetal colon. SUMMARY BACKGROUND DATA: Expression of NT/N is localized to the mucosa of the adult small bowel but also has been identified in the fetal colon, which resembles the small bowel until the end of the second trimester. Ectopic NT/N expression has been shown in certain types of colon cancer, suggesting a reversion to a fetal phenotype. METHODS: Sensitive ribonuclease protection assays were used to determine NT/N expression in colon cancers and adjacent normal mucosa as well as colon cancers established as tumor xenografts and fetal colon samples. RESULTS: NT/N gene expression was shown in 4 of 12 (25%) human colon cancer xenografts and in 11 of 40 (28%) freshly resected colon adenocarcinomas; NT/N gene expression was not expressed in any of the samples of normal colonic mucosa adjacent to the tumors. The NT/N gene was expressed maximally in the fetal colon between 16 and 18 weeks' gestation; NT/N expression was decreased between 19 and 22 weeks and was not apparent in either the 24-week fetal colon or the adult samples. CONCLUSIONS: The NT/N gene expression is expressed transiently in the fetal colon during a development stage that is characterized by morphologic similarity to the small bowel. In addition, NT/N is reexpressed in approximately one fourth of the human colon cancers, indicating that neoplastic transformation leads to reversion to a fetal phenotype in certain types of colon cancer. The NT/N gene will provide a useful model to further define the complex differentiation pathways in the normal gut as well as the process of fetal "dedifferentiation" in certain types of colon cancer.     

microRNA-224在结肠癌细胞中的表达及意义

目的：探讨microRNA-224（miR-224）对结肠癌细胞中的表达及意义。 方法：用real-time PCR检测4种结肠癌细胞株（Caco-2、HCT116、HT-29、LoVo）和正常结肠黏膜组织中miR-224的表达水平;将HCT116细胞分别转染miR-224模拟物和阴性对照组序列,以未处理的HCT116细胞作为空白对照,用real-time PCR法检测各组细胞miR-224的表达水平,用MTT法和平板克隆实验法检测各组细胞的增殖情况,用流式细胞仪检测各组细胞周期情况。 结果：4种结肠癌细胞株miR-224的表达均明显高于正常结肠黏膜组织（均P<0.05）;与空白对照组HCT116细胞比较,miR-224模拟物转染组HCT116细胞miR-224的表达水平明显升高,增殖活力明显增强,细胞克隆数量明显增高（均P<0.05）;细胞周期G1到S期转换的趋势增强（P=0.074）;阴性对照组序列转染组HCT116细胞的各项指标差异均无统计学意义（均P>0.05）。 结论：miR-224在结肠癌细胞中表达上调,miR-224可能通过促进细胞增殖与细胞周期的演进,而在结肠癌发生发展的过程中发挥促癌基因的作用。     

癌细胞表面表达人绒毛膜促性腺激素的免疫荧光检测

目的筛选可供体外和动物体内肿瘤抑制试验的候选癌细胞株。方法通过间接免疫荧光法，用兔抗人绒毛膜促性腺激素(hCG)多克隆免疫球蛋白(IgG)和小鼠抗hCG单克隆免疫球蛋白(IgG)，对人结(直)肠癌细胞(HCT15、HCT116、KM12、WiDr、LoVo、LS-174)、前列腺癌细胞(PC3)、小细胞肺癌细胞(A549)的细胞表达hCG情况进行检测。结果被检的8个癌细胞株均对兔抗hCG多克隆免疫球蛋白(IgG)呈阳性反应。其中4株结(直)肠癌细胞(HCT115、HCT116、Lo-Vo、LS-174)和小细胞肺癌(A549)能被小鼠抗hCG单克隆免疫球蛋白染色。结论这5株能与小鼠抗hCG单克隆免疫球蛋白结合的细胞株都适用于以后的肿瘤杀伤试验。     

吉非替尼对结肠癌细胞的生长抑制作用与PTEN表达的关系

目的 观察表皮生长因子受体酪氨酸激酶抑制剂吉非替尼对人结肠癌细胞的生长抑制作用,探讨这种作用与结肠癌细胞PTEN表达的关系.方法 应用体外药物敏感实验检测吉非替尼对6种人结肠癌细胞系的生长抑制作用;应用RT-PCR检测不同结肠癌细胞中PTEN mRNA水平;应用Western blot 检测结肠癌细胞中PTEN蛋白表达水平.结果 吉非替尼在体外对6种结肠癌细胞系的生长抑制作用差异很大(F=325.51,P＜0.05).吉非替尼作用浓度为1 μmol/L时,Lovo细胞系抑制率达34%,对吉非替尼最为敏感,其半量抑制浓度(IC50)＜10 μmol/L;HT29和SW480为中度敏感(10μmol/L＜IC50＜100 μmol/L);而HCT116、LS174T和SW620不敏感,其IC50＞100 μmol/L.各个细胞系中PTEN mRNA和PTEN蛋白均有表达.结论 吉非替尼对结肠癌细胞的生长抑制作用与PTEN mRNA和PTEN蛋白表达水平无明显相关,即PTEN表达状态还不能作为预测结肠癌对吉非替尼敏感性的可靠生物学指标.     

长链非编码RNA MLK7-AS1在结肠癌中的表达及其对结肠癌细胞增殖的影响

背景与目的:长链非编码RNA(lncRNA)MLK7-AS1是一种新发现的与多种肿瘤发生发展密切相关的lncRNA,但其在结肠癌中的表达及其作用尚未见报道。因此,本研究旨在探讨lncRNA MLK7-AS1在结肠癌中的表达以及其对结肠癌细胞生物学行为的影响。方法:用qRT-PCR检测lncRNA MLK7-AS1在21对结肠癌组织与相对应的癌旁组织手术标本以及在不同结肠癌细胞系(SW480、HCT116、SW620、DLD1、HT29、LOVO)与正常结肠上皮细胞(NCM460)中的表达。将结肠癌细胞转染lncRNA MLK7-AS1过表达质粒后,分别用MTS、平板克隆试验、流式细胞术、Western blot及qRT-PCR分别检测细胞活力、克隆形成能力、细胞周期以及细胞周期相关蛋白表达水平的变化。结果:lncRNA MLK7-AS1在结肠癌组织中的表达水平明显高于癌旁正常组织;在各结肠癌细胞株中表达水平明显高于正常结肠上皮细胞(均P<0.05)。将lncRNA MLK7-AS1表达量相对较低的SW480与HCT116转染lncRNA MLK7-AS1过表达质粒后,两种细胞的细胞活力和克隆形成能力均显著增强(均P<0.05);G1期细胞比例明显减少,S期细胞比例明显增加(均P<0.05);细胞周期相关蛋白cyclin D1和CDK6的表达水平均明显上升(均P<0.05)。结论:lncRNA MLK7-AS1在结肠癌中高表达,其高表达可以促进结肠癌细胞增殖,其机制可能与上调细胞周期相关蛋白cyclin D1及CDK6表达有关。     

环状RNA TADA2A在结直肠癌组织的表达及其对结直肠癌细胞增殖、凋亡的影响

目的观察环状RNA TADA2A在结直肠癌组织中的表达及其对结直肠癌细胞增殖、凋亡的影响。方法实时定量反转录聚合酶链反应(RT-qPCR)法检测58对结直肠癌组织及癌旁组织中circTADA2A的相对表达量,分析其与患者临床病理特征间的关系。构建circTADA2A过表达质粒及对照质粒并分别转染结直肠癌细胞株(人结直肠癌细胞LoVo、HCT116)。采用细胞计数试剂盒(CCK-8)实验及流式细胞术检测过表达circTADA2A对LoVo和HCT116细胞增殖能力、凋亡水平的影响。体内实验:将12只裸鼠采用随机数字表法分为2组,分别皮下注射转染circTADA2A(过表达组)及空载质粒(对照组)的结直肠癌细胞株HCT116,比较两组皮下瘤体积和质量。定性资料采用χ²检验或Fisher’s精确检验。定量资料采用t检验或非参数检验。结果circTADA2A在结直肠癌组织中的相对表达量(1.12±0.45)显著低于癌旁组织(0.48±0.22,t=9.620,P<0.01),且其表达量与与肿瘤T分期(χ²=6.855,P<0.05)、淋巴结转移(χ²=10.952,P<0.05)、TNM分期(χ²=6.023,P<0.05)、肿瘤分化程度(χ²=5.376,P<0.05)显著相关,差异均有统计学意义。CCK-8实验结果表明,过表达组LoVo和HCT116细胞48、72 h时增殖能力均显著低于对照组,48 h过表达组[LoVo为,(0.34±0.02);HCT116为,(0.31±0.03)比对照组LoVo为,(0.64±0.03);HCT116为,(0.53±0.04),tLoVo=11.190,tHCT116=7.510,P值均<0.01];72 h过表达组[LoVo为,(0.71±0.02);HCT116为,(0.60±0.15)比对照组LoVo为,(0.92±0.03);HCT116为,(0.79±0.02),tLoVo=10.060,tHCT116=12.050,P值均<0.01]。流式细胞结果显示,过表达组细胞凋亡率[LoVo为,(23.93±1.51)%;HCT116为,(20.97±2.36)%]均显著高于对照组[LoVo为,(7.60±0.57)%;HCT116为,(6.83±2.36)%,tLoVo=-17.420,tHCT116=-10.210,P值均<0.01],差异均有统计学意义。体内实验结果显示,过表达组皮下肿瘤[体积(500.1±71.0)mm3、质量(488.1±77.6)mg]均显著小于对照组[(940.8±51.6)mm3、(871.0±73.3)mg,t体积=12.280,t质量=8.780,P值均<0.01],差异均有统计学意义。结论circTADA2A在结直肠癌中发挥抑癌作用,通过促进细胞的凋亡水平进而抑制肿瘤细胞的增殖能力。     

miR-3126-5p靶向 LASP1抑制结直肠癌细胞的增殖和迁移的机制探讨

目的探讨微小RNA(miRNA)-3126-5p抑制靶基因LIM和SH3蛋白1(LIM and SH3 protein 1.LASP1)对结直肠癌细胞增殖和迁移能力的影响。方法采用实时定量聚合酶链式反应(qRT-PCR)法检测结直肠癌细胞株(HT-29、HCT116、LoVo、SW480)和正常肠黏膜上皮细胞(HIEC)中miR-3126-5p的表达水平。选择表达水平最低的细胞株作为实验对象,实验分为2组:阴性对照组(转染miR-NC)和miR-3126-5p组(转染miR-3126-5p),转染48 h后收集各组细胞。qRT-PCR法检测各组细胞miR-3126-5p的表达水平。采用MTS法和划痕愈合实验分别检测各组细胞的增殖水平和迁移能力。采用生物信息学软件microRNA.org和双荧光素酶报告基因实验分别预测和验证miR-3126-5p的靶基因。采用qRT-PCR和Western blot检测各组细胞靶基因的表达水平。计量资料以均数土标准差(Mean±SO)表示,两两组间比较采用t检验,多组间比较采用单因素方差分析结果与正常肠黏膜上皮细胞(HIEC)相比,结直肠癌细胞株miR-3126-5p的表达水平显著降低(P<0.05),表达水平最低的细胞株是HCT116细胞(P<0.01)。阴性对照组和miR-3126-5P组HCT116细胞中miR-3126-5p的表达分别为(1.05±0.16)和(7.91±1.26),差异具有统计学意义(t=5.40,P<0.01)。与阴性对照组相比,miR-3126-5p组HCT116细胞的增殖能力显著降低(P<0.05),迁移能力显著下降(t=4.52,F<0.01)。microRNA.org显示miR-3126-5p与LIM和SH3蛋白1(LASP1)基因mRNA存在互补结合位点。miR-3126-5p和L4SP/mRNA能够靶向结合(P<0.01)。与阴性对照组相比,miR-3126-5p组H CT116细胞中L4SP/基因表达显著降低(t=4.56,P<0.01)。结论结直肠癌细胞株中miR-3126-5p呈低表达,miR-3126-5p能够通过抑制靶基因LASP1降低结直肠癌HCT116细胞的增殖和迁移能力。     

RNA干扰沉默促肝细胞再生磷酸酶-3基因对结直肠癌细胞基质金属蛋白酶2和9表达的影响

目的 探讨促肝细胞再生磷酸酶-3(PRL-3)基因对结直肠癌细胞侵袭的影响和可能机制.方法 应用PRL-3基凶小干扰RNA(siRNA)转染处理结直肠癌细胞系HCT116后,分别采用实时定量PCR和Western印迹检测PRL-3基因和基质金属蛋白酶家族(MMP)-2、MMP-9的mRNA和蛋白水平;分别采用软琼脂集落培养试验和Boyden小室模型试验检测癌细胞的锚着不依赖性增殖和侵袭能力;其次,将转染48 h的细胞接种裸鼠,观察其在体内生长情况.结果 体外实验结果显示,PRL-3 siRNA可有效抑制结直肠癌细胞集落生长和侵袭能力,且与浓度相关(P＜0.05,P＜0.01));转染组细胞MMP-2、MMP-9 mRNA和蛋白水平明显下调(P＜0.05).体内实验结果显示,对照组裸鼠组织癌细胞侵袭横纹肌和血管,而转染组未见这些现象.结论 采用PRL-3siRNA转染可抑制结直肠癌细胞侵袭,其机制可能与下调MMP表达有关.     

Developmental expression of the neurotensin gene in the rat liver.

OBJECTIVE: This study determined whether the neurotensin gene is expressed during early development of the liver. SUMMARY BACKGROUND DATA: Neurotensin (NT), a gut tridecapeptide localized mainly to the distal small bowel and brain of adults, is an important hormone regulating gut motility, secretion and mucosal growth. Expression of NT peptide and the gene is found in fibrolamellar hepatocarcinomas, a variant of hepatocellular carcinoma, but not in the normal adult liver. METHODS: Northern and in situ hybridization techniques were used to determine expression of the neurotensin gene (NT/N) in the normal developing liver. RESULTS: NT/N is expressed in the fetal and early postnatal rat liver, but expression is repressed in the liver of the adult. In situ hybridization confirms the authors' Northern data and demonstrates a random distribution of NT/N expression in the fetal and 3-day postnatal liver. CONCLUSIONS: The authors conclude from this study that NT/N is expressed during early development of the rat liver with subsequent repression in the adult. NT/N may be reexpressed with malignant transformation of the liver.     

法尼酯X受体的激活抑制结肠癌细胞生长

目的 探讨法尼酯X受体（FXR）的激活是否抑制结肠癌细胞的生长。方法 对人结肠癌HCT-116细胞进行体外培养,用四唑氮蓝还原法（MTT）和流式细胞仪测定FXR特异性激动剂GW4064对结肠癌HCT-116细胞生长的抑制作用,同时应用RT-PCR方法检测其FXR mRNA及VEGF mRNA的表达。结果 FXR特异性激动剂GW4064可上调结肠癌HCT-116细胞的FXR mRNA表达,下调VEGF mRNA的表达; 对结肠癌HCT-116细胞的生长具有明显的抑制作用,并促进结肠癌HCT116细胞的凋亡,且均呈剂量及时间依赖关系。结论 FXR特异性激动剂GW4064可以显著抑制结肠癌HCT116细胞的生长,激活FXR受体可能为结肠癌的治疗提供一种潜在的靶点。     

人结肠癌细胞株HCT116中雌激素受体β与mTOR基因相互作用的初步研究

目的:探讨雌激素受体β(ERβ)在人结肠癌细胞株HCT116中的表达及其与mTOR基因的相互关系。方法:分别采用ERβ质粒转染(联合或不联合ERβ激动剂)、siRNA干扰mTOR基因、5-氮脱氧胞苷(5-aza-dC)处理HCT116细胞株;通过实时定量PCR法检测各处理组细胞中之mTOR、ERβ和cyclinD1的mRNA表达;蛋白印迹法检测p-mTOR、mTOR、ERβ和cyclinD1的蛋白表达。结果:HCT116细胞株转染ERβ质粒后,无论是否存在ERβ激动剂,都可明显下调p-mTOR和cyclinD1的蛋白表达水平,但是mTOR蛋白的表达却无变化。siRNA干扰细胞的mTOR基因后,ERβ表达明显增加而cyclinD1的mRNA和蛋白表达水平均下降。5-aza-dC处理后,能明显促进HCT116细胞株中ERβ的表达,mTOR基因在mRNA和蛋白水平的表达都无明显差异,但p-mTOR的蛋白水平降低,cyclinD1的mRNA和蛋白表达水平都下降。结论:ERβ和mTOR之间具有负相互调节作用;HCT116细胞中亦存在ERβ启动子甲基化的现象。这为ERβ及其特异性激动剂和mTOR抑制剂的联合应用防治结肠肿瘤提供了初步的实验依据。     

多种人结肠癌5-氟尿嘧啶耐药细胞株的建立及耐药机制初步研究

目的:通过建立多种5-氟尿嘧啶(5-FU)耐药的人结肠癌细胞株,探讨耐药的结肠癌细胞的生物学特性与耐药机制。方法:选用人结肠癌HT-29、LoVo和SW480细胞,通过高浓度5-FU反复接触结合药物浓度递增法建立耐药株HT-29/5-FU、LoVo/5-FU和SW480/5-FU。不同浓度5-FU作用所建立的耐药细胞株及其亲本细胞后,分别用MTT法、流式细胞术、qRT-PCR、Westernblot检测细胞对5-FU的敏感性、周期分布、耐药相关分子[P-糖蛋白(P-gp)、多药耐药相关蛋白1(MRP1)、ATP结合盒超家族G成员2(ABCG2)]及第十号染色体缺失的磷酸酶和张力蛋白同源物(PTEN)与蛋白激酶B(Akt)的mRNA和蛋白的表达,并用Akt活性检测试剂盒检测细胞Akt活性。结果:与各自的亲本细胞比较,构建的HT-29/5-FU、LoVo/5-FU和SW480/5-FU对5-FU的IC50均明显升高(均P0.05),耐药指数分别为7.213、5.849和15.940。随着5-FU处理浓度的升高,亲本细胞和耐药细胞G0/G1期细胞数量均明显增加(均P0.05),但同一浓度5-FU处理下,各耐药株G0/G1期细胞数量均明显少于其对应亲本株(均P0.05)。与各自的亲本细胞比较,对应耐药株的P-gp、MRP1、ABCG2、Akt的mRNA和蛋白表达水平均明显升高,而PTEN表达均明显降低(均P0.05),且Akt活性均明显提高(均P0.05)。结论:成功建立了结肠癌5-FU耐药细胞株,其耐药机制可能与PTEN下调所致的PI3K/Akt降低PI3K/Akt通路活化有关。     

Differential effects of gut hormones on pancreatic and intestinal growth during administration of an elemental diet.

Liquid elemental diets (ED) will, in time, cause atrophy of the gut. Pentagastrin (PG), neurotensin (NT), and bombesin (BBS) are peptides that have trophic effects on the gut of normal rats. This study examined the effect of these three agents on gut atrophy produced by ED. Four groups of rats were given an ED and injected with either saline (control), PG (250 micrograms/kg), NT (300 micrograms/kg), or BBS (10 micrograms/kg) subcutaneously every 8 hours for 5 or 10 days. A fifth group was fed rat chow ad libidum. The rats were killed on day 6 or 11; the pancreas and segments of small intestine were removed. Atrophy of ileal mucosa was apparent on days 6 and 11, and atrophy of jejunal mucosa was manifest by day 11. Bombesin prevented jejunal mucosal atrophy and significantly increased ileal mucosal growth (compared with control). Neurotensin prevented the jejunal, but not the ileal, mucosal atrophy produced by ED. Pentagastrin had no effect on gut mucosa. Bombesin and PG, but not NT, stimulated pancreatic growth. Neurotensin stimulates pancreaticobiliary secretions (PBS), which are known to stimulate gut growth. Jejunoileal bypass was performed to determine whether trophic effects of NT on gut mucosa were mediated through stimulation of PBS. After 1 week treatment, animals were killed and segments of intestine removed. As expected NT was trophic for gut mucosa in continuity with the luminal stream; furthermore NT produced significant stimulation of growth of gut mucosa in the bypassed segment. We conclude that both BBS and NT are trophic for intestinal mucosa of rats given ED; both agents have a more pronounced effect on jejunum. The trophic effect of NT is mediated, in part, by a mechanism unrelated to stimulation of PBS. Bombesin and NT may have important regulatory functions in the adaptive growth of small bowel mucosa and in the maintenance of gut mucosal integrity.     

Expression of the neurotensin gene in fetal human liver and fibrolamellar carcinoma.

OBJECTIVE: This study determined whether the neurotensin gene (NT/N) is expressed in the normal adult liver and focal nodular hyperplasia (FNH) and confirmed NT/N expression in fibrolamellar carcinoma; whether NT/N or the neurotensin receptor is expressed in the fetal liver; and whether hepatic resection leads to expression of NT/N. SUMMARY BACKGROUND DATA: Neurotensin (NT), a gut tridecapeptide localized in the gastrointestinal tract of the adult to the small bowel, is an important hormone-regulating gut motility, secretion, and mucosal growth. Expression of the NT/N gene has been identified in fibrolamellar carcinomas, but NT/N is not known to be expressed in the normal liver. METHODS: Sensitive ribonuclease (RNase) protection assays were used to determine whether NT/N is expressed in fibrolamellar carcinoma, FNH, or healthy fetal and adult livers. The authors also determined whether the receptor for NT was present in the fetal liver and whether liver resection and subsequent regeneration could lead to re-expression of NT/N in the rat. RESULTS: Neurotensin is expressed in fibrolamellar carcinoma and in the fetal human liver, but not in the adult liver or the samples of FNH. In addition, the authors were not able to detect expression of the NT receptor in the fetal liver and did not identify NT/N gene activation in the regenerating liver of the rat. CONCLUSIONS: The NT/N gene will be a useful molecular marker to differentiate fibrolamellar carcinoma from other liver tumors. The finding of NT/N expression in the fetal liver suggests a stem cell descendant that is common to both the liver and gut. The absence of NT/N expression in the regenerating liver suggests that NT does not play a role in this rapid growth process.     

与放疗抵抗相关的长链非编码RNA在不同放疗敏感性结直肠癌细胞株中的表达

目的 筛选与结直肠癌细胞放疗敏感性相关的长链非编码RNA（lncRNA）.方法 将HT29、SW480、RKO、Lovo和HCT116等5株结直肠癌细胞梯度照光后行克隆形成实验,通过细胞存活率（SF2值）来检测5株细胞的放疗敏感性差异;利用高通量lncRNA芯片筛选在SW480、RKO和Lovo细胞株中两两比较表达差异均大于2倍的lncRNA,并通过实时定量PCR进一步检测所选lncRNA在5株结直肠癌细胞中的表达差异.结果 5株结直肠癌细胞放疗敏感性由低至高（即SF2值由高至低）依次为HT29 （0.83±0.03）、SW480 （0.69±0.02）、RKO （0.53±0.02）、Lovo （0.47±0.05）和HCT116（0.32±0.03）（P＜0.01）.lncRNA芯片筛选得到5种与结直肠癌细胞放疗敏感性相关的lncRNA基因,其中R05532、NR_015441和NR_033374基因表达水平与细胞放疗抵抗呈正相关（均P＜0.01）,而NR_073156和AA745020基因表达水平与细胞放疗抵抗无明显相关性（均P＞0.05）.结论 R05532、NR_015441和NR_033374三种lncRNA可能成为结直肠癌细胞放疗敏感性的预测分子,其高表达提示放疗抵抗。