Vav3 is linked to poor prognosis of pancreatic cancers and promotes the motility and invasiveness of pancreatic cancer cells

Background/objectivesThe aim of this study was to investigate the role of the guanine nucleotide exchange factor Vav3 in the motility and invasiveness of pancreatic ductal adenocarcinoma (PDAC) cells.MethodsImmunohistochemistry was used to determine whether high Vav3 expression in human PDAC tissues is correlated with poor prognosis. Immunocytochemistry was used to determine the association and intracellular distribution of Vav3, Rac1 and Akt in PDAC cells. Phosphoprotein array analysis was performed to determine the Vav3-associated intracellular signaling pathways. Immunocytochemistry and Matrigel invasion assays were used to examine the effects of Vav3 on the formation of cell protrusions and PDAC cell invasion.ResultsExpression of Vav3 in PDAC tissue was significantly correlated with overall survival. Vav3 was localized in cell protrusions of migrating PDAC cells. Knockdown of Vav3 inhibited the motility and invasiveness of PDAC cells through a decrease in cell protrusions. The levels of active Rac1 or active Akt were not associated with the concentration of Vav3 in cell protrusions. The Vav3-dependent promotion of motility and invasiveness was not modulated by Rac1 or Akt. Additionally, knockdown of Vav3 increased phosphorylated WNK1 in PDAC cells, and knockdown of WNK1 inhibited the motility and invasiveness. This study suggests that Vav3 can be a useful marker for predicting the outcome of patients with PDAC and that Vav3 can promote PDAC cell motility and invasion through association with dephosphorylation of WNK1.ConclusionsVav3 was accumulated in cell protrusions, contributed to the formation of membrane protrusions, and thereby increased the motility and invasiveness of PDAC cells.     

运动相关蛋白Fascin在胰腺癌的表达及其临床意义

目的 探讨运动相关蛋白Fascin在胰腺癌的表达及其与临床病理特征的关系.方法 采用RT-PCR法检测SW1990、Patu8988、BxPC3、CfPAC1 4株胰腺癌细胞株Fascin mRNA表达;采用免疫组化方法 检测54例胰腺癌及42例相应癌旁胰腺组织Fascin蛋白表达.结果 胰腺癌细胞株SW1990、Patu8988、CfPAC1有Fascin mRNA表达,BxPC3无表达;54例胰腺癌组织Fascin蛋白表达阳性35例,占64.8%,42例癌旁胰腺组织中均无阳性表达.Fascin蛋白表达与肿瘤分化程度(P<0.01)和淋巴转移(P<0.05)呈显著正相关,但与肿瘤大小及远处转移无相关性(P>0.05).结论 Fascin蛋白在胰腺癌组织中有较高的阳性表达率,检测其表达有助于胰腺癌的诊断,并有助于判断胰腺癌恶性程度.     

CD109 promotes the tumorigenic ability and metastatic motility of pancreatic ductal adenocarcinoma cells

BackgroundAccumulating evidence indicates that CD109, a glycosylphosphatidylinositol-anchored glycoprotein, is highly expressed in human epithelial carcinomas of multiple organs including the pancreas, but its functional role in carcinoma development has not yet been fully clarified. The aim of this study was to investigate the role of CD109 in the malignancy of pancreatic ductal adenocarcinoma (PDAC).MethodsPDAC specimens of 145 cases were immunostained for CD109, and correlations between CD109 expression and clinicopathological conditions were analyzed. CD109 expression in PANC-1 cells, a PDAC-derived cell line, was decreased by siRNA or shRNA and its effect on the malignancy of PANC-1 cells was examined.ResultsSuppression of CD109 expression in PANC-1 cells resulted in reduction of in vitro cell motility and tumorigenicity in xenografts. Based on these results, we investigated the relationship between CD109 expression and metastasis of PDAC using tumor tissue specimens. Among 106 recurrent cases of 145 PDAC, there was a tendency for CD109-positive cases to be accompanied by distant metastasis.ConclusionsCD109 plays a critical role in the promotion of tumorigenic ability and cellular motility relating to metastasis of PDAC cells.     

Pancreatic stellate cells promote proliferation and invasiveness of human pancreatic cancer cells via galectin-3

AIM： To investigate the role of pancreatic stellate cells （PSCs） and galectin-3 （GAL-3） in the proliferation and infiltration of pancreatic cancer cell line SW1990. METHODS： Human pancreatic cancer cell line SW1990 and PSCs were cultured in vitro. Supernatant fluid of cultured PSCs and SW1990 cells was collected. Expression of GAL-3 in SW1990 cells and PSCs was detected by ELISA, RT-PCR and Western blotting. Proliferation of cultured PSCs and SW1990 cells was measured by 3-（4, 5-methylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay and flow cytometry. Infiltration of SW1990 cells was detected by a cell infiltration kit. RESULTS： SW1990 cells expressed GAL-3 and this was up-regulated by the supernatant fluid of cultured PSCs. PSCs did not express GAL-3. SW1990 cells stimulated proliferation of PSC,s via GAL-3. GAL-3 antibody inhibited SW1990 cell proliferation, while the supernatant fluid of PSCs stimulated proliferation of SW1990 cells through interaction with GAL-3 protein. The supernatant fluid of PSCs enhanced the invasiveness of SW1990 cells through interaction with GAL-3. CONCLUSION： GAL-3 and PSCs were involved in the proliferation and infiltration process of pancreatic cancer cells.     

Pleiotrophin promotes perineural invasion in pancreatic cancer

Perineural invasion(PNI)in pancreatic cancer is an important cause of local recurrence,but little is known about its mechanism.Pleiotrophin(PTN)is an important neurotrophic factor.It is of interest that our recent experimental data showed its involvement in PNI of pancreatic cancer.PTN strongly presents in the cytoplasm of pancreatic cancer cells,and high expression of PTN and its receptor may contribute to the high PNI of pancreatic cancer.Correspondingly,PNI is prone to happen in PTN-positive tumors.We thus hypothesize that,as a neurite growth-promoting factor,PTN may promote PNI in pancreatic cancer.PTN is released at the time of tumor cell necrosis,and binds with its highaffinity receptor,N-syndecan on pancreatic nerves,to promote neural growth in pancreatic cancer.Furthermore,neural destruction leads to a distorted neural homeostasis.Neurons and Schwann cells produce more N-syndecan in an effort to repair the pancreatic nerves.However,the abundance of N-syndecan attracts further PTN-positive cancer cells to the site of injury,creating a vicious cycle.Ultimately,increased PTN and N-syndecan levels,due to the continuous nerve injury,may promote cancer invasion and propagation along the neural structures.Therefore,it is meaningful to discuss the relationship between PTN/N-syndecan signaling and PNI in pancreatic cancer,which may lead to a better understanding of the mechanism of PNI in pancreatic cancer.     

Natural killer cells in pancreatic cancer stroma

Pancreatic cancer remains one of medicine’s largest areas of unmet need. With five-year survival rates of < 8%, little improvement has been made in the last 50 years. Typically presenting with advance stage disease, treatment options are limited. To date, surgery remains the only potentially curative option, however, with such late disease presentation, the majority of patients are unresectable. Thus, new therapeutic options and a greater understanding of the complex stromal interactions within the tumour microenvironment are sorely needed to revise the dismal outlook for pancreatic cancer patients. Natural killer (NK) cells are crucial effector units in cancer immunosurveillance. Often used as a prognostic biomarker in a range of malignancies, NK cells have received much attention as an attractive target for immunotherapies, both as cell therapy and as a pharmaceutical target. Despite this interest, the role of NK cells in pancreatic cancer remains poorly defined. Nevertheless, increasing evidence of the importance of NK cells in this dismal prognosis disease is beginning to come to light. Here, we review the role of NK cells in pancreatic cancer, examine the complex interactions of these crucial effector units within pancreatic cancer stroma and shed light on the increasingly attractive use of NK cells as therapy.     

胰星状细胞对胰腺癌细胞株Patu8988侵袭和转移的影响

目的:探讨永生化人胰星状细胞(IPSC)对胰腺癌细胞株Patu8988侵袭和转移的影响.方法:制备IPSC上清,用IPSC上清和Patu8988共培养,以单独培养的Patu8988为对照,比较实验组与对照组细胞的增殖、黏附能力.侵袭、迁移能力,克隆形成以及抵抗H2O2诱导的Patu8988凋亡能力.结果:与单独培养的胰腺癌细胞株Patu8988相比,IPSC上清对胰腺癌细胞株Patu8988细胞的增殖、黏附、迁移、侵袭能力及克隆形成能力有促进作用(均p<0.05),并能抑制H2O2诱导的Patu8988的凋亡(P<0.05).结论:胰星状细胞可能通过增强胰腺癌细胞株Patu8988的增殖、黏附、迁移、侵袭能力及克隆形成能力,并抑制其的凋亡,在胰腺癌的发展和转移中起重要作用.     

Midkine promotes perineural invasion in human pancreatic cancer

AIM:To investigate midkine(MK)and syndecan-3protein expression in pancreatic cancer by immunohistochemistry,and to analyze their correlation with clinicopathological features,perineural invasion,and prognosis.METHODS:Pancreatic cancer tissues(including adequately sized tumor tissue samples and tissue samples taken from areas less than 2.0 cm around the tumor)were taken from 42 patients who were undergoing a partial duodenopancreatectomy.MK and syndecan-3proteins were detected by immunohistochemistry using a standardized streptavidin-peroxidase method,and analyzed for their correlation with clinicopathological features,perineural invasion,and prognosis.Associations of neural invasion with aggressive characteristics of pancreatic cancer and the presence of perineural invasion were assessed by two independent observers blinded to the patient status.RESULTS:MK and syndecan-3 were found in 26(61.9%)and 24(57.1%)specimens,respectively.MK and syndecan-3 expression was associated with perineural invasion(P=0.018 and 0.031,respectively).High MK expression was closely associated with advanced tumor,node and metastasis stage(P=0.008),lymph node metastasis(P=0.042),and decreased postoperative survival at 3years(51.0%vs 21.8%,P=0.001).Syndecan-3 levels were correlated with tumor size(P=0.028).Patients who were syndecan-3 negative had a higher cumulative survival rate than those who were positive,but the difference was not significant(44.0%vs 23.0%,P>0.05).CONCLUSION:MK and syndecan-3 are frequently expressed in pancreatic cancer and associated with perineural invasion.High expression of MK and syndecan-3may contribute to the highly perineural invasion and poor prognosis of human pancreatic cancer.     

Fascin与Ki-67在分化差的非小细胞肺癌中的表达

目的观察Fascin与Ki-67在非小细胞肺癌中的表达情况,探讨其表达与肿瘤生物学行为及临床病理指标的关系。方法对选自2004-06~2005-02北京协和医院病理科档案的肺叶切除标本对51例不同组织学类型及临床分期的非小细胞肺癌进行Fascin和Ki-67免疫组化染色,分别计算Fascin的阳性率及Ki-67指数,统计分析不同病理特征的差异。结果51例非小细胞肺癌中,Fascin的总阳性率为52.9%,其中2例高分化的黏液表皮样癌和4例支气管肺泡癌Fascin表达均为阴性,而4例大细胞癌和3例多形性癌Fascin表达阳性;腺癌中Fascin阳性率为43.5%,而在鳞癌中阳性率为66.7%。随着癌分化程度的降低,Fascin的阳性率上升,统计学分析有极显著性差异(P<0.01)。Ki-67的阳性表达与肿瘤的分化程度呈正相关,且Fascin阳性组的Ki-67指数显著高于阴性组。除Fascin表达在男性病人较高外,没有其它临床病理特征的相关性。结论Fascin在分化差的NSCLC中表达上调,与Ki-67指数呈正相关。Fascin是NSCLC分化差、恶性度高的标记。     

BTG-2基因在人胰腺癌中的表达及其与胰腺癌细胞增殖和凋亡的关系

目的探讨BTG-2基因在人胰腺癌中的表达及与胰腺癌细胞增殖和凋亡的关系。方法应用免疫组化、原位杂交等技术,对32例胰腺癌及癌旁组织中BTG-2基因进行检测。结果BTG-2基因在胰腺癌旁组织中相对含量为0.76±0.17,在胰腺癌组织中相对含量为0.58±0.16(P<0.01);PCNA指数 - 的胰腺癌细胞中BTG-2相对含量为0.90±0.12,PCNA指数 以上的胰腺癌细胞中BTG-2相对含量为0.66±0.12(P<0.01);BTG-2基因高表达的标本中可见少量的凋亡细胞,而低表达和中等表达的胰腺癌组织中未见明显凋亡细胞。结论BTG-2基因的低表达与胰腺癌的发生发展相关。     

T cells in pancreatic cancer stroma

Pancreatic ductal adenocarcinoma (PDAC) is a highly devastating disease with a dismal 5-year survival rate. PDAC has a complex tumour microenvironment; characterised by a robust desmoplastic stroma, extensive infiltration of immunesuppressive cells such as immature myeloid cells, tumour-associated macrophages, neutrophils and regulatory T cells, and the presence of exhausted and senescent T cells. The cross-talk between cells in this fibrotic tumour establishes an immune-privileged microenvironment that supports tumour cell escape from immune-surveillance, disease progression and spread to distant organs. PDAC tumours, considered to be non-immunogenic or cold, express low mutation burden, low infiltration of CD8⁺ cytotoxic lymphocytes that are localised along the invasive margin of the tumour border in the surrounding fibrotic tissue, and often display an exhausted phenotype. Here, we review the role of T cells in pancreatic cancer, examine the complex interactions of these crucial effector units within pancreatic cancer stroma and shed light on the increasingly attractive use of T cells as therapy.     

Cyclic-AMP-stimulated synthesis and release of carcinoembryonic antigen by pancreatic cancer cells

Summary The effect of cyclic adenosine 3′∶5′-monophosphate (cAMP) upon the synthesis and release of carcinoembryonic antigen (CEA) was studied in the human pancreatic ductal cancer cell line, SW-1990. Incubation for up to 24 h with forskolin, an activator of adenylate cyclase, or isobutylmethyl xanthine, a theophylline analog, increased cellular cAMP levels by over 100-fold and significantly increased CEA release and cellular CEA content. Whereas cAMP levels were augmented within 10 min of exposure to these agents, CEA release and CEA cell content were not increased until 90 min and 24 h, respectively. Similar results were obtained using dibutyryl-cAMP, a cAMP analog, but not using sodium butyrate, a metabolite of dibutyryl-cAMP. Cells were incubated with³⁵S-cysteine and³H-glucosamine in the presence or absence of forskolin in order to compare the effects of high cAMP levels upon the synthesis and release of total proteins, total glycoproteins, and immunoprecipitable CEA. Both CEA synthesis and release were enhanced by forskolin, but these effects were not specific to CEA since the release of labeled proteins and glycoproteins also increased. In addition, altered CEA expression caused by forskolin was consistently associated with a cessation of cell division, an effect which was reversible upon removing the agent. There was no effect upon cell morphology or viability. The data indicate that increased levels of cellular cAMP in pancreatic cancer cells is associated with decreased cell proliferation and increased expression of CEA and other glycoproteins.     

Metformin induces apoptosis of pancreatic cancer cells

AIM：To assess the role and mechanism of metformin in inducing apoptosis of pancreatic cancer cells.METHODS：The human pancreatic cancer cell lines ASPC-1,BxPc-3,PANC-1 and SW1990 were exposed to metformin.The inhibition of cell proliferation and colony formation via apoptosis induction and S phase arrest in pancreatic cancer cell lines of metformin was tested.RESULTS：In each pancreatic cancer cell line tested,metformin inhibited cell proliferation in a dose dependent manner in MTS（3-（4,5-dimethylthiazol-2-yl）-5-（3-carboxymethoxyphenyl）-2-（4-sulfophenyl）-2H-tetrazolium assays）.Flow cytometric analysis showed that metformin reduced the number of cells in G1 and increased the percentage of cells in S phase as well as the apoptotic fraction.Enzymelinked immunosorbent assay（ELISA） showed that metformin induced apoptosis in all pancreatic cancer cell lines.In Western blot studies,metformin induced poly-ADP-ribose polymerase（PARP） cleavage（an indicator of caspase activation） in all pancreatic cancer cell lines.The general caspase inhibitor（VAD-fmk） completely abolished metformin-induced PARP cleavage and apoptosis in ASPC-1 BxPc-3 and PANC-1,the caspase-8 specific inhibitor（IETD-fmk） and the caspase-9 specific inhibitor（LEHD-fmk） only partially abrogated metformin-induced apoptosis and PARP cleavage in BxPc-3 and PANC-1 cells.We also observed that metformin treatment dramatically reduced epidermal growth factor receptor（EGFR） and phosphorylated mitogen activated protein kinase（P-MAPK） in both a time-and dose-dependent manner in all cell lines tested.CONCLUSION：Metformin significantly inhibits cell proliferation and apoptosis in all pancreatic cell lines.And the metformin-induced apoptosis is associated with PARP cleavage,activation of caspase-3,-8,and-9 in a time-and dose-dependent manner.Hence,both caspase-8 and-9-initiated apoptotic signaling pathways contribute to metformin-induced apoptosis in pancreatic cell lines.     

Value of ultrasound examination in differential diagnosis of pancreatic lymphoma and pancreatic cancer

AIM： To investigate the value of clinical manifestations and ultrasound examination in the differential diagnosis of pancreatic lymphoma and pancreatic cancer. METHODS： The clinical and ultrasonic characteristics of 12 cases of pancreatic lymphoma and 30 cases of pancreatic cancer were retrospectively analyzed. RESULTS： Statistically significant differences were found in the course of disease, back pain, jaundice, carcino-embryonic antigen （CEA） and CA19-9 increase, palpable abdominal lump, superficial lymph node enlargement, fever and night sweats, lesion size, bile duct expansion, pancreatic duct expansion, vascular involvement, retroperitoneal （below the renal vein level） lymph node enlargement, and intrahepatic metastasis between pancreatic lymphoma and pancreatic cancer. There were no significant differences in age of onset, gender ratio, weight loss, nausea and vomiting, lesion position, the echo of the lesion, and the blood flow of the lesion. CONCLUSION： Pancreatic lymphoma should be considered for patients with long lasting symptoms, superficial lymph node enlargement, palpable abdominal lump, fever and night sweats, relatively large lesions, and retroperitoneal （below the level of the renal vein） lymph node enlargement. A diagnosis of pancreatic cancer should be considered more likely in the patients with relatively short disease course, jaundice, back pain, CEA and CA19-9 increase, relatively small lesions, bile duct expansion, obvious pancreatic duct expansion, peripheral vascular wrapping and involvement, or intrahepatic metastases.     

Pancreatic stellate cells: Aiding and abetting pancreatic cancer progression

Tumour-stromal interactions have now been acknowledged to play a major role in pancreatic cancer (PC) progression. The abundant collagenous stroma is produced by a specific cell type in the pancreas-the pancreatic stellate cell (PSC). Pancreatic stellate cells (PSCs) are a unique resident cell type of pancreas and with a critical role in both healthy and diseased pancreas. Accumulating evidence indicates that PSCs interact closely with cancer cells as well as with other cell types of the stroma such as immune cells, endothelial cells and neuronal cells, to set up a growth permissive microenvironment for pancreatic tumours, which facilitates local tumour growth as well as distant metastasis. Consequently, recent work in the field has focused on the development of novel therapeutic approaches targeting the stroma to inhibit PC progression. Such a multi-pronged approach targeting both tumour and stromal elements of PC has been successfully applied in pre-clinical settings. The challenge now is to translate the pre-clinical findings into the clinical setting to achieve better outcomes for pancreatic cancer patients.     

胰腺癌干细胞的研究进展

胰腺癌是恶性程度极高的消化道肿瘤,是全球癌症相关性死亡的主要原因之一.由于发病机制尚不明确,早期缺乏特征性临床表现及诊断方法,且传统治疗效果欠佳,导致胰腺癌的发病率及死亡率居高不下.近年来,随着干细胞在多个领域研究的不断推进,胰腺癌干细胞(pancreatic cancer stem cells,PCSCs)在胰腺癌发...     

蟾毒灵介导JNK信号通路诱导人胰腺癌细胞的凋亡

目的:研究蟾毒灵诱导人胰腺癌细胞凋亡以及凋亡相关基因表达的JNK信号转导通路,揭示其抗胰腺癌的部分机制.方法:MTT法观察蟾毒灵对人胰腺癌BxPC-3细胞的生长抑制作用;0.16、0.32、0.64mg/L蟾毒灵分别作用人胰腺癌BxPC-3细胞48h后,流式细胞仪(flow cytometry,FCM)检测细胞周期和细胞凋亡;Western印迹法检测蟾毒灵作用BxPC-3细胞后SAPK/JNK信号通路的激活情况,荧光定量PCR检测Survivin基因mRNA的表达水平;并比较阻断JNK信号通路后丹参酮ⅡA对胰腺癌细胞凋亡Survivin基因mRNA的表达.结果:MTT法测得蟾毒灵对人胰腺癌BxPC-3细胞具有显著的抑制作用,其作用效果与剂量和作用时间成正相关;0.16、0.32、0.64mg/L浓度蟾毒灵作用人胰腺癌细胞后的细胞凋亡率分别为19.36%±0.39%、40.69%±0.44%、59.63%±1.14%,与对照组2.24%±0.37%比较均有显著性差异(P<0.01);蟾毒灵作用人胰腺癌细胞1h后JNK信号通路被激活,2h达峰值;阻断JNK信号通路后,凋亡率明显降低(P<0.01);0.32mg/L蟾毒灵作用人胰腺癌细胞48h后Survivin mRNA的表达明显下降;阻断JNK信号通路后,蟾毒灵作用人胰腺癌细胞的Survivin mRNA的表达明显上升.结论:蟾毒灵通过JNK信号转导通路下调人胰腺癌BxPC-3细胞Survivin mRNA的表达,可能是其诱导胰腺癌细胞凋亡的机制.