胰腺癌干细胞的研究进展

目的 总结有关胰腺癌干细胞的研究进展并明确今后的研究方向.方法 收集国内、外近年来有关胰腺癌干细胞的文献并进行综述.结果 胰腺癌恶性程度高,早期诊断困难,缺乏有效治疗手段.近年来的研究发现,胰腺癌中存在异质性细胞,这些细胞具有干细胞的性质,该细胞亚群在胰腺癌的发生、增殖、转移和耐药中发挥重要作用,通常利用细胞表面的特异标志物来鉴别胰腺癌干细胞.另外,研究还发现,胰腺癌干细胞内的一些维持自我更新和转移的信号通道表达异常.结论 针对干细胞的治疗是可行的,深入了解胰腺癌干细胞的生物学行为将为胰腺癌的诊断和治疗提供新的策略和手段.     

生长抑素对胰腺癌生长抑制和凋亡作用的实验研究

目的 :探讨外源性生长抑素类似物施他宁对胰腺癌细胞的生长抑制和凋亡作用。方法 :采用MTT和细胞流式仪观测施他宁对胰腺癌细胞的生长抑制和凋亡的作用 ,并分析其对胰腺癌移植瘤的生长影响。结果 :发现PC - 3细胞在高浓度施他宁的作用下生长缓慢 ,与低浓度比较抑制率有明显差异 (P <0 .0 5) ,并与施他宁浓度呈依赖关系。施他宁对胰腺癌细胞凋亡有促进作用 ,凋亡率为 6.31 % ,而非治疗组的细胞凋亡率为 0 .48% ,两组间有非常显著差异(P <0 .0 5)。在移植瘤中 ,施他宁治疗组在肿瘤重量和肿瘤生长速度上均小于对照组 ,其差异有统计学意义 (P <0 .0 5)。结论 :施他宁对胰腺癌生长起抑制作用和促进凋亡作用。有潜在的临床应用价值     

Plasma Fatty Acid Composition in Continuous Ambulatory Peritoneal Dialysis Patients: An Increased Omega-6/Omega-3 Ratio and Deficiency of Essential Fatty Acids

Abstract

Patients with end-stage renal disease, including those treated with peritoneal dialysis, have a high risk for death, particularly from cardiovascular causes. Plasma fatty acid (FA) composition is used as an indicator of disease risk, because its alteration has been related to metabolic disease and cardiovascular disease. For this purpose, we have measured plasma FA composition in continuous ambulatory peritoneal dialysis (CAPD) patients and compared them with those of healthy subjects. This study was performed on 51 (21 M, 30 F) CAPD patients at least 6 months under dialysis, aged 20–75 years (mean 47.81 ± 11.8 years) and 45 (25 M, 20 F) healthy control subjects aged 20–60 years (mean 38.62 ± 12.9 years). Plasma 10-cis-pentadecanoic acid, 10-cis-heptadecanoic acid, heneicosanoic acid, tricosanoic acid, nervonic acid, saturated fatty acid, and monounsaturated FA levels and delta 9 desaturase activity were significantly higher whereas linoleic acid, linolenic acid, 11,14-eicosedienoic acid, arachidonic acid, docosahexaenoic acid, and omega-3 FA levels were significantly lower in the CAPD group than those in the healthy group. Our results show that there are FA abnormalities and especially a depletion in essential FA levels and a high level of omega-6/omega-3 ratio in CAPD patients, the underlying mechanism of which is not known and needs to be investigated. Therefore, we believe that essential FA supplementation should be encouraged for CAPD patients.     

吉西他滨与胰腺癌化疗耐药

目的探讨胰腺癌对吉西他滨化疗产生耐药性的相关机理。方法复习近年国、内外相关文献，对介导胰腺癌吉西他滨耐药性的主要基因及信号通路加以综述。结果癌基因c—Src与bcl—X1、NF-κB炎症信号通路、细胞因子IL-1β及NO等与介导胰腺癌对吉西他滨的耐药性密切相关；多药耐药基因MDR1／P-gP与胰腺癌吉西他滨耐药的相关性仍有待研究。结论癌基因c—Src与bcl—X1、NF-κB炎症信号通路等可能成为新的治疗靶点以增加胰腺癌的化疗敏感性；介导胰腺癌化疗耐药的关键基因与中心信号通路尚有待阐明。     

Impact of Supplementing Preoperative Intravenous Omega 3 Fatty Acids in Fish Oil on Immunomodulation in Elderly Patients Undergoing Hip Surgery

The aim of this study was to evaluate the immunomodulatory effects of supplementing intravenous omega-3 fatty acids in fish oil (IVFO) in elderly patients undergoing hip surgery. This was a single centre, randomized, controlled, comparative, phase IV study in elderly patients undergoing hip surgery. The subjects, within the age range of 50–90 years, were assigned randomly to the group receiving intravenous omega-3 fatty acids in fish oil (IVFO, Omegaven®) or the control group not receiving intravenous fish oil (n = 20 in each group). IL-6, IL-8, IL-10, and HS-CRP levels were the inflammatory markers assessed in this study. The within-group comparison was done by paired t-test and between-group comparison by unpaired t-test. At day 4, IL-6 values in the IVFO group decreased as compared to day 0. At day 4, IL-8 mean values increased for both IVFO and control groups. This increase was highly significant in the control group (P = 0.0182). IL 10 values decreased at day 4 and increased at day 8 in the IVFO group. Increase in HS-CRP levels was nonsignificant at day 4 in the IVFO group (P = 0.60) and significant at day 8 for the control group (P = 0.0084) as compared to day 0. Various biochemical parameters including albumin, protein, SGOT, SGPT, blood glucose, and urea values generated evidence regarding the safety profile of IVFO. This study suggests a role for IVFO in the short-term suppression of inflammatory mediators for patients undergoing hip surgery. However, further, larger trials may be needed to establish its definitive role in this patient population.     

胰腺癌细胞survivin表达RNAi抑制载体的构建及其抑制作用的研究

目的构建胰腺癌细胞生存蛋白（survivin）表达的RNA干扰（RNAi）抑制载体，并研究其对survivin表达的抑制作用。方法用免疫荧光技术和RT-PCR检测胰腺癌细胞PANC-1中survivin及其mRNA的表达，并把survivin基因克隆到T载体进行测序；构建针对survivin缺失碱基基因和survivin基因的RNAi载体si-svv-1和si—SVV-2，用脂质体转染胰腺癌细胞PANC-1后，用RT—PCR、DNA梯状电泳及流式细胞术分析比较2种干扰载体对survivin mRNA表达的抑制情况和检测细胞凋亡。结果survivin在胰腺癌细胞PANC-1中高表达；si—svv-2对survivin mRNA的表达抑制率达（72．43&#177;8．04）％，而si—svv-1为0；si—svv-2能诱导胰腺癌细胞PANC-1的凋亡，72h细胞凋亡率达（12．36&#177;1．44）％。结论本研究成功建立胰腺癌细胞survivin表达RNAi抑制载体，该载体可特异有效地抑制胰腺癌细胞PANC-1survivin的表达并诱导胰腺癌细胞PANC-1凋亡。     

Docetaxel/Gemcitabine Followed by Gemcitabine and External Beam Radiotherapy in Patients With Pancreatic Adenocarcinoma

Background Pancreatic cancer remains highly lethal. Previous attempts with neoadjuvant therapy in this disease have been inconclusive, but a potential for benefit exists. We conducted a phase II trial of dose-intense docetaxel and gemcitabine followed by twice-weekly gemcitabine and external beam radiotherapy in patients with pancreatic adenocarcinoma. Methods Patients with stage I to III disease were eligible. Docetaxel 65 mg/m² intravenously over 1 hour and gemcitabine 4000 mg/m² given intravenously over 30 minutes were given on days 1, 15, and 29. On day 43, radiotherapy was begun at 50.4 Gy with gemcitabine 50 mg/m² intravenously over 30 minutes twice weekly for 12 doses. After treatment, patients were considered for resection. Results Twenty-four assessable patients were recruited onto the trial. All but one patient completed a full 12 weeks of therapy. Grade 3 and 4 hematological and nonhematological toxicities were common but manageable, and neutropenic fever did not occur. No patient had local tumor progression. Twelve patients (50%) responded by Response Evaluation Criteria in Solid Tumors Group (RECIST) criteria, including one radiographic complete response. Seventeen patients underwent resection after therapy. Margin-negative resections were performed in 13 patients, including 9 patients whose disease was borderline or unresectable before treatment. A treatment effect was seen in all resection specimens. There have been no local recurrences of tumor, and several patients remain alive without evidence of disease. Conclusions Docetaxel/gemcitabine followed by gemcitabine/radiotherapy is active in the treatment of pancreatic adenocarcinoma, with manageable toxicity. Tumor downstaging occurs in some patients to allow complete resection. Further investigation of this regimen is warranted. M.A.B. is now at Wake-Forest University Baptist Medical Center, Winston-Salem, North Carolina; J.M.C. is now at Vanderbilt University, Nashville, Tennessee.     

汉防己甲素和吉西他滨协同使用对化疗耐药胰腺癌细胞的凋亡诱导作用

目的：研究汉防己甲素对胰腺癌化疗耐药产生与凋亡的影响。方法：分对照组（只加培养基）、吉西他滨组（Gemcitabine组）和汉防己甲素联合吉西他滨组（Tet/Gem组）,后2组采用不同浓度汉防己甲素和吉西他滨作用于人胰腺癌敏感株BxPC-3和吉西他滨耐药株BxPC-3/Gem细胞,通过MTT法检测抗肿瘤药物的细胞毒作用,碘化丙啶（PI）染色检测细胞凋亡。结果：BxPC-3/Gem耐药胰腺癌细胞株耐药指数（RF）为4.70,汉防己甲素作用耐药胰腺癌细胞后其RF降至1.69,证明汉防己甲素可逆转BxPC-3/Gem耐药胰腺癌细胞对吉西他滨的耐药。化疗耐药胰腺癌细胞凋亡在12h、18h、24h,Tet/GEM组与GEM组、对照组比较,差异有非常显著性意义（P〈0.01）。结论：汉防己甲素可以逆转BxPC-3/Gem耐药胰腺癌细胞对吉西他滨的耐药,协同吉西他滨促进对化疗耐药胰腺癌细胞凋亡作用。     

游离脂肪酸对大鼠肾小球系膜细胞增殖和细胞周期的影响

目的：探讨游离脂肪酸（FFAs）对体外培养的大鼠肾小球系膜细胞增殖和生长周期的影响。方法：用不同浓度的游离脂肪酸处理大鼠HBZY-1细胞株（即大鼠肾小球系膜细胞）24h～72h。采用噻唑蓝比色（MTT）法检测内皮细胞增殖情况,流式细胞术（FCM）分析法测定细胞周期变化。结果：游离脂肪酸可抑制HBZY-1细胞的生长增殖（与对照组比较,P〈0.01）,且这种抑制作用具有剂量和时间依赖性;游离脂肪酸作用于HBZY-1细胞24h、48h、72h,细胞周期发生明显改变,G1期细胞数增多,S期细胞数减少（与对照组比较,P〈0.01）。结论：游离脂肪酸可通过停滞细胞生长于G1期,抑制大鼠肾小球系膜细胞的生长增殖。     

替格列扎对游离脂肪酸诱导的肾小管上皮细胞凋亡的影响

目的:探讨替格列扎对游离脂肪酸诱导的肾小管上皮细胞(HK-2)凋亡的影响。方法:通过MTT法检测细胞的增殖,分光光度法检测细胞MDA表达和SOD活性;ELISA检测细胞上清中的MCP-1和IL-8水平;Real-time PCR及Western blot分别检测Bax和Bcl-2的mRNA和蛋白表达水平。结果:游离脂肪酸呈剂量和时间依赖性抑制HK-2细胞的增殖,并使细胞Bax的蛋白表达的显著上升,Bcl-2的蛋白表达显著下降。替格列扎的加入显著减轻游离脂肪酸对HK-2细胞增殖的抑制作用,并使细胞Bax的mRNA与蛋白表达下降,而Bcl-2的mRNA与蛋白的表达上升。同时细胞SOD表达水平上升,MDA的表达水平下降;炎症介质MCP-1和IL-8表达水平均下降。结论:游离脂肪酸诱导的肾小管上皮细胞凋亡具有时间和剂量依赖性。替格列扎可通过减少氧化应激,抑制炎症反应,上调Bcl-2以及下调Bax的表达来抑制游离脂肪酸诱导的细胞凋亡,从而减少其的肾毒性。     

Adjuvant/Perioperative Therapy in Pancreatic and Periampullary Cancer

The delivery of postoperative combined modality adjuvant therapy for completely resected pancreatic adenocarcinoma was initially shown to be beneficial based on a prospective, randomized trial published 30 years ago. Since then, oncologists have debated whether chemotherapy alone, chemoradiation, or both are optimal adjuvant therapies following pancreatectomy for pancreatic ductal adenocarcinomas (PDAC). No global consensus has emerged, and there is no one superior modality despite randomized trials in part, to poor trial design, poor patient selection, and poor therapy options itself. We need to have a disciplined approach to the selection of patients for pancreatectomy, pathologic assessment of surgical resection margins, and postoperative (pre-treatment) imaging. In the era of the multidetector CT optimized for pancreatic imaging, tumors of “borderline resectability” have emerged as a distinct subset of PDAC. The attempt to standardize the definition of borderline resectable is a work in progress and modified with time. This distinction (between resectable and borderline resectable) is essential to minimize potentially confounding results of clinical trials. Additionally, preoperative therapy is not only preferred but mandatory in a large population of borderline resectable patients. Ultimately, as we develop more effective systemic therapies for PDAC, proceeding with surgery after a period of induction therapy will be even more compelling especially if there is a clear positive impact on overall survival.     

Effects of Omega-3 Fatty Acids on Serum Lipids,Lipoprotein (a), and Hematologic Factors in Hemodialysis Patients

Abstract

Background: Lipid abnormalities, especially high serum lipoprotein (a) [Lp (a)] concentration, and anemia are two major causes of cardiovascular diseases (CVDs) in hemodialysis patients. Therefore, this study was designed to investigate the effects of marine omega-3 fatty acids on serum lipids, Lp (a), and hematologic factors in hemodialysis patients. Methods: Thirty-four hemodialysis patients were randomly assigned to either omega-3 fatty acid supplement or placebo group. Patients in the omega-3 fatty acids group received 2080 mg marine omega-3 fatty acids, daily for 10 weeks, whereas the placebo group received a corresponding placebo. At baseline and the end of week 10, 7 mL blood was collected after a 12- to 14-h fast and serum triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), Lp (a), blood hemoglobin, hematocrit, red blood cells (RBCs), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were measured. Results: Serum triglyceride decreased significantly in the omega-3 fatty acids group at the end of week 10 compared with baseline (p < 0.05) and this reduction was significant in comparison with the placebo group (p < 0.01). No significant differences were observed between the two groups in mean changes of serum total cholesterol, LDL-C, HDL-C, Lp (a), blood hemoglobin, hematocrit, RBC, MCV, MCH, and MCHC. Conclusion: The results of our study indicate that marine omega-3 fatty acids can reduce serum triglyceride, as a risk factor for CVD, but it does not affect other serum lipids, Lp (a), and hematologic factors in hemodialysis patients.     

Development and Characterization of Gemcitabine-Resistant Pancreatic Tumor Cells

Background Pancreatic cancer is an exceptionally lethal disease with an annual mortality nearly equivalent to its annual incidence. This dismal rate of survival is due to several factors including late presentation with locally advanced, unresectable tumors, early metastatic disease, and rapidly arising chemoresistance. To study the mechanisms of chemoresistance in pancreatic cancer we developed two gemcitabine-resistant pancreatic cancer cell lines. Methods Resistant cells were obtained by culturing L3.6pl and AsPC-1 cells in serially increasing concentrations of gemcitabine. Stable cultures were obtained that were 40- to 50-fold increased in resistance relative to parental cells. Immunofluorescent staining was performed to examine changes in β-catenin and E-cadherin localization. Protein expression was determined by immunoblotting. Migration and invasion were determined by modified Boyden chamber assays. Fluorescence-activated cell sorting (FACS) analyses were performed to examine stem cell markers. Results Gemcitabine-resistant cells underwent distinct morphological changes, including spindle-shaped morphology, appearance of pseudopodia, and reduced adhesion characteristic of transformed fibroblasts. Gemcitabine-resistant cells were more invasive and migratory. Gemcitabine-resistant cells were increased in vimentin and decreased in E-cadherin expression. Immunofluorescence and immunoblotting revealed increased nuclear localization of total β-catenin. These alterations are hallmarks of epithelial-to-mesenchymal transition (EMT). Resistant cells were activated in the receptor protein tyrosine kinase, c-Met and increased in expression of the stem cell markers CD (cluster of differentiation)24, CD44, and epithelial-specific antigen (ESA). Conclusions Gemcitabine-resistant pancreatic tumor cells are associated with EMT, a more-aggressive and invasive phenotype in numerous solid tumors. The increased phosphorylation of c-Met may also be related to chemoresistance and EMT and presents as an attractive adjunctive chemotherapeutic target in pancreatic cancer.     

Successful Resection of Advanced Pancreatic Tail Cancer After Neoadjuvant Gemcitabine Chemotherapy: Report of a Case

Pancreatic cancer with distant metastasis is not an indication for surgery, and the median survival of these patients is less than 3 months. We report the case of a patient who has survived for 21 months without any signs of recurrence after resection of advanced pancreatic cancer following a course of chemotherapy with gemcitabine (GEM). A 75-year-old man was hospitalized for anorexia and emaciation. Examinations showed pancreatic cancer with distant peritoneal metastasis. After the main tumor and metastasis had been shrunk by GEM chemotherapy, we performed distal pancreatectomy combined with splenectomy. Microscopically, the main tumor was confirmed as moderately differentiated tubular adenocarcinoma with interstitium and fibrosis. The radicality of the surgery was R0, according to the TNM classification of the UICC. The patient recovered well and has had no clinical symptoms for 40 months since the initial chemotherapy. This case suggests that multidisciplinary treatment with GEM may prolong the survival of some patients with unresectable pancreatic cancer.     

IGFBP 3在白藜芦醇抑制胃癌细胞增殖过程中的作用

目的研究在白藜芦醇（Res）抑制胃癌细胞增殖过程中,胰岛素样生长因子结合蛋白 3（IGFBP 3）表达的变化。方法噻唑蓝（MTT）法测定Res对BGC 823细胞增殖的抑制程度,实时荧光定量聚合酶链反应（qRT PCR）和Western blot技术检测Res处理后BGC 823细胞中IGFBP 3表达变化,siRNA技术沉默IGFBP 3基因表达,MTT法观察Res对BGC 823细胞增殖的影响,流式细胞技术测定各组细胞凋亡率。结果Res能够抑制BGC 823生长,经20,40,80,160 μmol·L－1Res处理后,细胞存活率分别为（82.35±10.65）%,（74.30±12.36）%,（62.80±14.66）%,（50.75±11.14）%。Res刺激后,IGFBP 3表达水平升高,与对照组比较,IGFBP 3 mRNA水平增高2.96 倍（P＜0.05）, IGFBP 3蛋白水平变化与其mRNA一致。siRNA技术沉默IGFBP 3表达后,160 μmol·L－1Res刺激BGC 823细胞,细胞存活率下降（78.5±9.86）%,但高于同浓度下Res刺激的未经IGFBP 3沉默的BGC 823细胞（P＜0.05）。IGFBP 3沉默后,160 μmol·L－1Res处理后BGC 823细胞凋亡率（20.13±9.12）%,明显低于未经IGFBP 3沉默的BGC 823细胞［（35.48±11.12）%］,且差异有统计学意义（P＜0.05）。结论Res可以抑制BGC 823细胞增殖,促进其凋亡。该机制涉及IGFBP 3高表达。     

虫草素对胰腺癌BxPc-3、BxPc3-LN5细胞株增殖抑制作用的研究

目的研究虫草素对胰腺癌细胞株BxPc3及其传代高转移潜能细胞株BxPc3-LN5的生长抑制作用,为虫草素是否可用于胰腺癌临床化疗进行理论探讨。方法应用四甲基噻唑蓝比色法（MTT比色法）对虫草素诱导的人胰腺癌BxPc3、Bx-Pc3-LN5细胞株进行检测和观察。结果虫草素均对于BxPc3、BxPc3-LN5细胞株有抑制效果。结论虫草素对BxPc3及BxPc3-LN5的细胞毒作用在一定范围内呈剂量和时间依赖关系。