Objective To investigate the mechanism of the resistance of pancreatic cancer cells to tumor necrosis factor related apoptosis inducing ligand (TRAIL)mediated apoptosis. MethodsThe expression of TRAIL receptor-4 (TRAIL-R4) in normal pancreas tissue and pancreatic cancer was analyzed by using Northern blotting, Western blotting and immunohistochemistry.ResultsTRAIL-R4 mRNA and protein were expressed at moderate to high levels in human pancreatic cancer, but demonstrated weak to negative in the normal pancreas. Moreover, pancreatic cancer cells showed b TRAIL-R4 immunostaining throughout the tumor mass. Conclusion TRAIL-R4 levels are significantly different in pancreatic cancer in comparison to the normal pancreas. These findings give new insights into the resistance mechanisms of pancreatic cancer cells towards TRAILmediated apoptosis.
Objective To summary the principle of magnetic resonance spectroscopy imaging and its application progress in diagnosis and differential diagnosis of pancreatic cancer. Methods The newest related literatures of home and abroad were collected and reviewed. Results Magnetic resonance spectroscopy imaging was a technology using the magnetic resonance phenomena and chemical shift phenomena to measure molecular organization. The spectroscopy most commonly used in clinical and scientific research includes 1H， 31P， and 23Na. Conclusion Magnetic resonance spectroscopy as the only approach to noninvasive quantitative provding biochemical information in vivo， has an important significance to the diagnosis and differential diagnosis of pancreatic cancer.
Objective To investigate the inhibitory effect of survivin antisense oligonucleotides (ASODN) on proliferation of pancreatic cancer cells PANC-1. Methods The ASODN and sense oligodeoxynucleotides (SODN) were complementary to survivin sequences. FAM-marked ASODN was transfected into PANC-1 cells mediated by positive ion liposome as ASODN group. Blank control group (normal cells), negative control group (normal medium)， and SODN group were established for comparison. The transfection efficiency was detected by flow cytometry (FCM) after transfection; MTT assay was used to detect cytotoxicity; Cell morphological changes were examined by transmission electron microscopy; The cell cycle and apoptotic rate were analyzed by FCM; Immunohistochemical staining techniques were used, and the expressions of survivin were observed under light microscopy, examined and analysed by computer image. Results ①The transfection efficiency was 31.9%, 37.4%, 41.4%, 52.6%, 24.2%, 11.4%, 16.1%, and 15.5% when the transfecting concentration of ASODN was 50, 100, 150, 200, 250, 400, 600, and 800 nmol/L, respectively; The transfection efficiency was 12.0%, 50.8%, and 11.2% when the inoculated cells was 2×104/well, 2×105/well, and 2×106/well, respectively; The transfection efficiency was 58.8%, 34.0%, and 23.6% when 2 μl, 3 μl, and 4 μl liposome was used during transfection, respectively. ②Cell gap was oversize, morphous was round, adherent cells were less after transfection under fluorescence microscope. ③The inhibition rate in the ASODN group was higher than that in each control group (Plt;0.05) on 24, 36, 48 h after treating by survivin ASODN, which increased as time prolonged (Plt;0.05). ④The apoptosis showed a ladder-shaped line in the ASODN group. ⑤Apoptotic morphology was demonstrated in the ASODN group, such as apoptotic cells with nuclear chromatin highly concentrated, crescent nuclear staining aggregated by the side nuclear membrane, nucleolus disappeared by AO and EB stains. ⑥The apoptotic rate 〔（38.1±3.4）%〕 in the ASODN group was higher than that in the SODN group 〔（4.16±1.7）%〕, Plt;0.05. ⑦G2/M cell cycle arrested in the ASODN group. ⑧After transfection, the expression of survivin protein in the ASODN group was significantly lower than that of each control group (Plt;0.05). Conclusions The optimal transfection conditions are as following: the cell count of 2×105/well, concentration of ASODN 200 nmol/L, and cationic liposome oligofectamine 2 μl, respectively. Survivin ASODN can inhibit the proliferation of pancreatic cancer cells and induce their apoptosis.
Objective To introduce the research progress in the effect of chemotherapeutic resistance of metabolic enzymes of gemcitabine to pancreatic cancer.Methods Recent literatures about metabolic enzymes that played key roles in mediating gemcitabine chemotherapeutic resistance of pancreatic cancer were collected and reviewed. Results The metabolic enzymes of gemcitabine, such as hENT1, dCK, RRM1 and CDA, were closely related to chemotherapeutic resistance of pancreatic cancer. The relationship between the single nucleotide polymorphism of metabolic enzymes and the resistance to gemcitabine remained to be clarified. Conclusion Multiple factors are involved in the mechanism of chemotherapeutic resistance of pancreatic cancer to gemcitabine, which needs further research.
ObjectiveTo investigate the expression of ubiquitin-specific protease 9X (USP9X) in pancreatic cancer, and to evaluate the correlation of USP9X with the survival of patients with pancreatic cancer. MethodThe expression of USP9X was detected in 55 pieces of surgically resected primary pancreatic cancer tissues and adjacent nontumorous pancreatic tissues by streptavidin-perosidase immunohistochemical method. ResultsThe rate of USP9X high expression in the 55 pieces of the primary pancreatic cancer tissues was 58.2% (32/55), which in the adjacent nontumorous pancreatic tissues was zero. The expression of USP9X was not correlated with the gender, age, tumor position, or tumor size (P > 0.05), while which was significantly correlated with the differentiation degree, lymph node metastasis, or TNM stage (P < 0.05). By using Cox proportional hazard model, the multivariable analysis revealed that the differentiation degree, lymph node metastasis, and USP9X expression were the independent risk factors. Survival of the patient with USP9X high expression was significantly shorter than that with USP9X low expression (P < 0.05), and there was the same result in the patients with stageⅡ, with lymph node negative, or intermediate differentiation degree (P < 0.05). ConclusionThe results indicate that USP9X might play an important role in the pathogenesis and prognosis of pancreatic cancer.
Objective To investigate the effect of angiostatin gene combined with somastatin on inhibiting proliferation of human pancreatic cancer cell BXPC-3 and endothelial cell of vascular ECV-304 and on inducing their apoptosis in vitro. Methods The pcDNA3/angio was transfected BXPC-3 by liposome-mediated gene transfer method. RT-PCR and Western blot were used to detect the expression of angiostatin gene. In vitro, MTT and flow cytometry (FCM) were used to detect whether angiostatin gene combined with somastatin could effect the growth inhibition of BXPC-3 and ECV-304 cells. Results Angiostatin was expressed and secreted by transfected BXPC-3. The growth of BXPC-3 was inhibited by certain concentration of somatostatin (≥10 μg/ml, P＜0.01）, which was dependent on the dose of somatostatin in a concentration extent; Simultaneity apoptosis was induced （P＜0.01）. But the growth of ECV-304 was not inhibited with somatostation （Pgt;0.05）. Angiostatin could inhibit the growth of ECV-304 and induced apoptosis （P＜0.01）, but it had no effect on the growth of BXPC-3 （Pgt;0.05）. Angiostation gene combined with somatostation could inhibit the growth both of BXPC-3 and ECV-304 （P＜0.01）, and induce apoptosis of them （P＜0.01）; but the effect couldn’t be additived. Conclusions ①Somatostatin directly inhibits the proliferation of human pancreatic cancer cells and induces apoptosis, but it doesn’t directly inhibit angiogenesiso of human pancreatic cancer. ②Angiostatin specially inhibits the proliferation of endothelial cell of vascular and induces apoptosis. Angiostatin could inhibit angiogenesis of human pancreatic cancer to induce necrosis of cancer cell.
Objective To investigate the invasion ability of Panc-1 cells in vivo and in vitro af ter being t ransfected with tissue factor pathway inhibitor 2 gene ( TFPI-2) . Methods The expression vector pEGFP-C1-TFPI-2 was transfected into human pancreatic cancer line Panc-1 cells by using liposome. TFPI-2 mRNA and protein of transfected and nontransfected cells were detected by reverse t ranscription-polymerase chain reaction (RT-PCR) and Western blot respectively. The tumor cells invasive behavior of t ransfected ( Panc-1-TFPI-2) and nontransfected ( Panc-1-V and Panc-1-P) cells were assessed in vitro through Boyden Chamber method. The transfected and nontransfected cells were implanted into nude mice to observe it s growth and metastasis in vivo. Results Expressions of mRNA and protein of TFPI-2 were confirmed in transfected cells. Af ter TFPI-2 t ransfection , the number of Panc-1-TFPI-2 , Panc-1-V and Panc-1-P cells passing through membrane of Boyden Chamber were 24. 4 ±3. 5 ,61. 3 ±4. 1 and 60. 2 ±3. 9 , respectively. The number of TFPI-2-expressing cells to t raverse a Matrigel-coated membrane was obviously decreased compared with that of non-expressing cells , the invasion ability was lower than that before transfection in vitro. The subcutaneous tumor volume of the Panc-1-TFPI-2 group was (438. 0 ±69. 8) mm3 , the Panc-1-V group was (852. 0 ±102. 9) mm3 and the Panc-1-P group was (831. 0 ±78. 1) mm3 , P lt; 0. 05. The metastasis to liver and lung and muscular invasion occurred in the Panc-1-V group and the Panc-1-P group. There were no muscular invasion and metastatic lesions in the Panc-1-TFPI-2 group. Conclusion TFPI-2 gene expression may obviously inhibit the invasion ability of pancreatic cancer cells in vitro and in vivo , which provides an experimental basis for the treatment of human pancreatic cancer by gene therapy.
Objective To summarize the domestic and abroad articles related to the research on the relation between microRNA （miRNA） and pancreatic cancer，and explore the important effects of miRNA expression patterns in diagnosis of pancreatic cancer. Methods “microRNA and pancreatic cancer” were searched as key words by PubMed and CNKI series full-text database retrieval systems from 2000 to 2012. Totally 60 English papers and 15 Chinese papers were obtained. Choice criteria：the basic research of miRNA and pancreatic cancer，the clinical research of miRNA and pancreatic cancer， and the prospect of miRNA in pancreatic cancer diagnosis and treatment. According to the choice criteria，31 papers were finally analyzed. Results The miRNA expression spectrum and specific miRNA expression such as miR-21，miR-34，miR-217，miR-196a，miR-10a，miR-155，miR-221，miR-222，miR-181a，miR-181b，miR-181d， and the family members of miR-200 and let-7 might be used as tumor markers to differentiate pancreatic cancer from normal pancreas，chronic pancreatitis or pancreatic endocrine tumors，and might be used as prognostic factor to predict the outcome. Conclusions miRNA expression spectrum are not only related to diagnosis of pancreatic cancer， but also have provided a new research direction and method for gene therapy of pancreatic cancer．
Objective To summarize the research progress of alternative splicing in pancreatic cancer, and to provide reference for further research. MethodThe experimental and clinical studies of alternative splicing in pancreatic cancer were reviewed.Results Alternative splicing dysregulation resulted in changed gene expression or novel isoform formation, thereby influencing the carcinogenesis, progression or chemoresistance of pancreatic cancer. The differentially expressed alternative splicing isoforms may serve as diagnostic markers, indicators of aggressiveness or prognostic markers of pancreatic cancer. Conclusion Further investigation of the molecular mechanisms of alternative splicing in carcinogenesis and progression of pancreatic cancer is a new way to improve the early diagnosis and treatment of pancreatic cancer.
【Abstract】Objective To investigate the relationship between the development of pancreatic cancer and inflammation, and the therapy strategy.Methods Related articles were reviewed.Results The pathogenesis of inflammation in pancreatic cancer development involves cytokines, NF-κB, COX-2, PPAR-γ, DNA damage, gene changes，etc. Based on these mechanisms some medications are under developing. Conclusion Accumulative effects of pancreatic inflammation may lead to DNA changes, and even pancreatic cancer development. Medications aimed at suppressing pancreatic inflammation may help with prevention and treatment of pancreatic cancer.