Pancreatic carcinoma cells express neuropilins and vascular endothelial growth factor, but not vascular endothelial growth factor receptors

BACKGROUND: Neuropilins (NRPs) are characterized as coreceptors of vascular endothelial growth factor (VEGF). In the current study, the authors assessed the expression of NRPs, VEGF, and vascular endothelial growth factor receptors (VEGFRs), as well as VEGF-induced cell proliferation, in pancreatic carcinoma cell lines and tissue specimens. METHODS: Human pancreatic carcinoma cell lines (Panc-1 and MIA PaCa-2), normal human pancreatic ductal epithelial cells (HPDE), and human umbilical vein endothelial cells (HUVECs) were cultured. Human pancreatic adenocarcinoma tissue specimens were also studied. Expression levels of NRPs, VEGFRs, and VEGF were determined by real-time polymerase chain reaction analysis and immunostaining. Cell proliferation was examined using a [3H]thymidine incorporation assay. RESULTS: Both NRP-1 and NRP-2 were expressed in Panc-1 cells, HPDE cells, and HUVECs but were expressed minimally in MIA PaCa-2 cells. Panc-1 expressed 30 times more NRP-1 mRNA than NRP-2 mRNA. NRP-1 levels in Panc-1 cells were 5.3 times higher than in HPDE cells but were similar to NRP-1 levels in HUVECs. NRP-2 levels in Panc-1 cells were similar to NRP-2 levels in HPDE cells but lower than NRP-2 levels in HUVECs. Expression of all three VEGFRs was observed only in HUVECs. However, VEGF mRNA was detected in all cell types except for HUVECs. NRP-1 immunoreactivity levels were much higher than NRP-2 immunoreactivity levels in Panc-1 and human pancreatic adenocarcinoma tissue specimens, whereas VEGFRs were not detected in either of these two settings. In response to VEGF165, [3H]thymidine incorporation in Panc-1 cells increased significantly (by 61%; P < 0.01). A monoclonal antibody against human NRP-1 significantly blocked VEGF-induced cell proliferation in Panc-1 cells. CONCLUSIONS: The pancreatic carcinoma cell line Panc-1 and adenocarcinoma tissue specimens expressed high levels of NRP-1 and VEGF, but not VEGFRs, and exogenous VEGF significantly increased NRP-1-mediated, but not VEGFR-mediated, Panc-1 cell proliferation. These data suggested that NRP-1 may be involved in the pathogenesis of pancreatic carcinoma.     

Metastatic-associated biological properties and differential gene expression profiles in established highly liver and peritoneal metastatic cell lines of human pancreatic cancer

To elucidate metastasis mechanisms, we established a Panc-1H5 subline with a highly liver metastatic cell line and a Panc-1P4a with a highly peritoneal metastatic cell line, which were sequentially selected from the parental pancreatic cancer cell line Panc-1. Using these three cell lines, we investigated several biological properties and mRNA levels of differentially-expressed genes involved in cancer metastasis with a cDNA macroarray. The tumorigenicity, motile activity, adhesive activity and cytokine production of metastatic sublines were higher than those of parental Panc-1 cells. Particularly, in Panc-1H5 cells, adhesive activity to the extracellular matrix and angiogenetic factors increased, whereas in Panc-1P4a cells, motile activity was extremely enhanced compared with Panc-1 cells. Histopathological findings for the three cell lines were the same. In cDNA macroarray analysis of Panc-1H5 cells, 11 genes were up-regulated and 20 genes were down-regulated compared with parental Panc-1 cells. In Panc-1P4a cells, 7 genes were up-regulated and 13 genes were down-regulated compared with parental Panc-1 cells. This study provides a demonstration of global gene expression analysis of pancreatic cancer cells with liver and peritoneal metastasis and these results provide new insight into the study of human pancreatic cancer metastasis.     

CD147 silencing via RNA interference reduces tumor cell invasion, metastasis and increases chemosensitivity in pancreatic cancer cells

CD147, which belongs to the immunoglobulin superfamily, is a multifunctional glycoprotein that has been shown to increase tumor invasion, metastasis and multidrug resistance. To define the role of CD147 in invasion and metastasis more precisely, we utilized gene silencing to inhibit the expression of CD147 in pancreatic cancer cells. We observed that CD147 expression was significantly impeded at both the mRNA and protein levels and resulted in a decrease of MMP-2 and MMP-9 activities. There was also a decrease of MCT1 expression in the invasion and metastasis potential of pancreatic cancer cells, as well as increased chemosensitivity to gemcitabine in Panc-1 cells. Overall, these results suggest that CD147 plays an important role in the invasion, metastasis and chemosensitivity of the human pancreatic cancer cell line Panc-1, indicating that CD147 may be a promising therapeutic target for pancreatic cancer.     

Regulation of vascular endothelial growth factor receptor-1 expression by specificity proteins 1, 3, and 4 in pancreatic cancer cells

Vascular endothelial growth factor receptor-1 (VEGFR1) is expressed in cancer cell lines and tumors and, in pancreatic and colon cancer cells, activation of VEGFR1 is linked to increased tumor migration and invasiveness. Tolfenamic acid, a nonsteroidal anti-inflammatory drug, decreases Sp protein expression in Panc-1 and L3.6pl pancreatic cancer cells, and this was accompanied by decreased VEGFR1 protein and mRNA and decreased luciferase activity on cells transfected with constructs (pVEGFR1) containing VEGFR1 promoter inserts. Comparable results were obtained in pancreatic cancer cells transfected with small inhibitory RNAs for Sp1, Sp3, and Sp4 and all three proteins bound to GC-rich elements in the VEGFR1 promoter. These results show that VEGFR1 is regulated by Sp proteins and that treatment with tolfenamic acid decreases expression of this critical angiogenic factor. Moreover, in vitro studies in Panc-1 cells show that activation of VEGFR1 by VEGFB to increase mitogen-activated protein kinase 1/2 phosphorylation and cell migration on collagen-coated plates is also inhibited by tolfenamic acid. Thus, targeted degradation of Sp proteins is highly effective for inhibiting VEGFR1 and associated angiogenic responses in pancreatic cancer.     

过氧化物酶体通路氧化应激基因与青蒿琥酯抗胰腺癌敏感性的相关性研究

目的：探讨过氧化物酶体通路活性氧氧化应激关键基因的筛选及其与青蒿琥酯抗胰腺癌敏感性的相关性。方法基于美国国立癌症研究所（NCI）公共数据库55株肿瘤细胞表达谱基因芯片数据,采用 Kendall 相关分析方法筛选出与青蒿琥酯抗肿瘤半抑制浓度（IC50）显著相关的过氧化物酶体通路关键基因。利用荧光定量 PCR 验证候选基因在不同青蒿琥酯敏感性胰腺癌细胞的 mRNA 表达差异,并通过 DAB 染色检测胰腺癌细胞内过氧化物酶体含量。结果13个过氧化物酶体生物合成、增殖及其活性氧氧化应激通路关键基因 mRNA 表达与青蒿琥酯抗肿瘤药敏浓度 IC50有显著相关性。与正常肝细胞 HL-7702（1．00）比较,对青蒿琥酯敏感的胰腺癌 Panc-1细胞过氧化物酶体生物合成基因CRAT（2．89±0．06）、PEX11B（1．90±0．07）、PEX16（1．35±0．07）mRNA 相对表达水平均显著增高（t ＝33．00,P ＜0．01;t ＝17．85,P ＜0．01;t ＝4．54,P ＜0．05）;其活性氧氧化应激的抗氧化基因 CAT（1．43±0．03）、SOD1（2．07±0．04）、SOD2（1．15±0．01）mRNA 相对表达水平亦显著增高（t ＝11．71,P ＜0．01;t ＝35．85,P ＜0．01;t ＝13．22,P ＜0．01）;对青蒿琥酯不敏感的胰腺癌 BXPC-3细胞的 PEX12（0．51±0．02）、CAT（0．47±0．02）、PRDX1（0．43±0．01）、SOD1（0．44±0．01）mRNA 相对表达水平显著低于正常肝细胞 HL-7702（t ＝37．53,P ＜0．01;t ＝16．52,P ＜0．01;t ＝84．20,P ＜0．01,t ＝48．24,P ＜0．01）。DAB 染色显示对青蒿琥酯敏感的胰腺癌 Panc-1细胞过氧化物酶体阳性表达率（61．5％）明显高于HL-7702细胞（43．8％）,差异有统计学意义（χ2＝16．11,P ＜0．01）。结论过氧化物酶体及其活性氧相关抗氧化酶 CAT、PRDX1、SOD 基因表达可能是影响青蒿琥酯抗胰腺癌作用敏感性的重要因素。     

Correlation of glypican-1 expression with TGF-beta, BMP, and activin receptors in pancreatic ductal adenocarcinoma

Glypican1 (GPC1) is a cell surface heparan sulfate proteoglycan that acts as a co-receptor for heparin-binding growth factors as well as for members of the TGF-beta family. GPC1 plays a role in pancreatic cancer by regulating growth factor responsiveness. In view of the importance of members of the TGF-beta family in pancreatic cancer, in the present study, the role of GPC1 in TGF-beta, BMP and activin signaling was analyzed. Quantitative RT-PCR and immunohistochemistry were utilized to analyze GPC1 and TGF-beta, BMP and activin receptor expression levels. Panc-1 and T3M4 pancreatic cancer cells were transfected in a stable manner with a GPC1 antisense expression construct. Anchorage-dependent and -independent growth was determined by MTT and soft agar assays. TGF-beta1, activin-A and BMP-2 responsiveness was determined by MTT assays and immunoblotting with p21, p-Smad1, and p-Smad2 antibodies. QRT-PCR demonstrated increased GPC1 mRNA levels in pancreatic ductal adenocarcinoma (PDAC) compared to normal pancreatic tissues (NPT), as described previously. There was a significant correlation between GPC1 mRNA levels and TbetaRII, act-R1a, act-R1b, act-R2a, BMP-R1a, and BMP-R2 mRNA expression in NPT. In contrast, GPC1 mRNA expression correlated directly with act-R1a and BMP-R1a in N0 PDAC cases and with act-R2a and BMP-R1a in lymph node positive cases. Down-regulation of GPC1 resulted in increased doubling time in Panc-1 but not in T3M4 cells, and decreased anchorage-independent growth in both cell lines. GPC1 down-regulation resulted in a slightly altered response towards TGF-beta1, activin-A and BMP-2 in terms of growth, p21 induction and Smad2 phosphorylation. In conclusion, enhanced GPC1 expression correlates with BMP and activin receptors in pancreatic cancer. GPC1 down-regulation suppresses pancreatic cancer cell growth and slightly modifies signaling of members of the TGF-beta family of growth factors.     

肿瘤坏死因子相关的凋亡诱导配体对胰腺癌细胞抗肿瘤作用的研究

Objective To investigate the antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)gene transfection mediated by adenovirus into human pancreatic carcinoma cell line Panc-1, and the mechanisms involved in this effect. Methods TRAIL gene was transfected into pancreatic cancer cell line Panc-1 by an adenovirus vector (Ad-TRAIL).Level of TRAIL mRNA expression was determined using RT-PCR, and TRAIL protein synthesis was evaluated with Western blot. Cell-growth activities were determined by MTT assay. The bystander effect was observed by co-culturing the Panc-1cells with the transfected TRAIL gene at different ratios. Apoptosis in pancreatic cancer cells was detected by flow cytometry.Procaspase-8 and procaspase-3 were determined by Western blot. Results The stable overexpression of TRAIL was detected in Panc-1 cells transfected by Ad-TRAIL. Ad-TRAIL significantly inhibited of cell viability of Panc-1 cells. Furthermore,co-culture of cancer cells transfected with TRAIL with that nontransfected resulted in the cell death of both cells by bystander effect. Moreover, the percentage of apoptotic cells was significantly higher in the Ad-TRAIL-treatment group compared to the control groups (P ＜ 0.01). And there was a diminished amount of procaspase-8 and procaspase-3 after infection with Ad-TRAIL. Conclusion The overexpression of TRAIL gene in Panc-1 cells by Ad-TRAIL exerts its antitumor effects, and themechanisms involved in this effect may be proapoptosis and bystander effect.     

miR-375和PDK1在胰腺癌组织中的表达及两者的相关性

目的探讨miR-375与PDK1在胰腺癌中的表达及两者的相关性。方法qRT-PCR方法检测胰腺癌组织及胰腺癌细胞系中miR-375、PDK1表达,转染miR-375模拟物上调其在Panc-1中的表达,检测转染后Panc-1中PDK1表达变化。结果miR-375在人胰腺癌组织中表达下调,在Panc-1中表达较HEK293明显降低。PDK1在胰腺癌组织中表达上调,在Panc-1中表达较HEK293明显增高。转染miR-375模拟物上调Panc-1中miR-375表达后,转染组PDK1表达较空白组和阴性对照组均明显下降。结论miR-375在胰腺癌中发挥抑癌基因作用,对PDK1具有负调控作用。     

Pancreatic stellate cells: partners in crime with pancreatic cancer cells

Pancreatic stellate cells (PSC) produce the stromal reaction in pancreatic cancer, but their role in cancer progression is not fully elucidated. We examined the influence of PSCs on pancreatic cancer growth using (a) an orthotopic model of pancreatic cancer and (b) cultured human PSCs (hPSC) and human pancreatic cancer cell lines MiaPaCa-2 and Panc-1. Athymic mice received an intrapancreatic injection of saline, hPSCs, MiaPaCa-2 cells, or hPSCs + MiaPaCa-2. After 7 weeks, tumor size, metastases, and tumor histology were assessed. In vitro studies assessed the effect of cancer cell secretions on PSC migration and the effect of hPSC secretions on cancer cell proliferation, apoptosis, and migration. Possible mediators of the effects of hPSC secretions on cancer cell proliferation were examined using neutralizing antibodies. Compared with mice receiving MiaPaCa-2 cells alone, mice injected with hPSCs + MiaPaCa-2 exhibited (a) increased tumor size and regional and distant metastasis, (b) fibrotic bands (desmoplasia) containing activated PSCs within tumors, and (c) increased tumor cell numbers. In vitro studies showed that, in the presence of pancreatic cancer cells, PSC migration was significantly increased. Furthermore, hPSC secretions induced the proliferation and migration, but inhibited the apoptosis, of MiaPaCa-2 and Panc-1 cells. The proliferative effect of hPSC secretions on pancreatic cancer cells was inhibited in the presence of neutralizing antibody to platelet-derived growth factor. Our studies indicate a significant interaction between pancreatic cancer cells and stromal cells (PSCs) and imply that pancreatic cancer cells recruit stromal cells to establish an environment that promotes cancer progression.     

Potential involvement of IL-8 and its receptors in the invasiveness of pancreatic cancer cells

The purpose of the present study was to examine the expression of interleukin (IL)-8 and IL-8 receptors and to evaluate the effects of IL-8 on human pancreatic cancer. We examined the expression of IL-8 and its two receptors (CXCR1 and CXCR2) in 40 surgically resected human pancreatic cancer tissues and in three different human pancreatic cancer cell lines (PANC-1, MIAPaCa-2 and Capan-2). The immunohistochemical analysis using specific antibodies demonstrated that positive staining for IL-8, CXCR1 and CXCR2 in surgically resected human pancreatic cancer was 50, 55 and 65%, respectively. Moreover, 40% of these cases were positive for both IL-8 and IL-8 receptors. In contrast, immunoreactive signals for those proteins were extremely suppressed in normal pancreatic tissues. All of the pancreatic cancer cell lines expressed IL-8 and IL-8 receptors at the RNA and protein levels. Receptor binding experiments using 125I-labeled IL-8 showed that PANC-1 cells had specific binding sites for IL-8. The cell proliferation assay demonstrated that IL-8 did not affect the growth of the three cell lines. However, treatment with IL-8 enhanced the invasiveness into Matrigel and increased the activity of matrix metalloproteinase (MMP)-2 in supernatants of the PANC-1 cells. These results demonstrate that IL-8 and IL-8 receptors are over-expressed in pancreatic cancer, and suggest that IL-8 regulates MMP-2 activity and plays an important role in the invasiveness of human pancreatic cancer.     

胰腺癌Panc-1细胞TFPI-2基因甲基化状态与其体内体外侵袭能力的关系

目的:探讨甲基化酶抑制剂5-氮杂-2'-脱氧胞苷(5-aza-2-deoxycytidine,5-Aza-dC)对胰腺癌Panc-1细胞体内体外侵袭能力及裸鼠皮下移植肿瘤组织TFPI-2基因甲基化状态及表达的影响.方法:用不同浓度的5-Aza-dC处理胰腺癌Panc-1细胞.Transwell法测定各组Panc-1细胞的体外侵袭能力.将用药物处理过的各组Panc-1细胞分别接种于裸鼠皮下,观察各组成瘤率及肿瘤大小.用MSP及RT-PCR检测裸鼠移植瘤组织TFPI-2基因甲基化状态及TFPI-2基因mRNA表达情况.结果:与对照组相比,药物处理组Panc-1细胞体外侵袭能力明显下降,裸鼠成瘤率明显降低,第八周时,肿瘤体积明显低于对照组(P<0.05).与对照组相比,TFPI-2基因异常甲基化状态在药物处理组裸鼠移植瘤组织中得到逆转,药物处理组移植瘤TFPI-2基因mRNA重新表达,并呈剂量依赖性(P<0.05).结论:甲基化酶抑制剂5-氮杂-2'-脱氧胞苷可能在一定程度上抑制人胰腺癌Panc-1细胞系的体内体外侵袭和生长能力,其机制可能与逆转TFPI-2基因高甲基化状态从而恢复其表达有关.     

Paracrine SDF-1α signaling mediates the effects of PSCs on GEM chemoresistance through an IL-6 autocrine loop in pancreatic cancer cells

Pancreatic cancer exhibits the poorest prognosis among all tumors and is characterized by high resistance to the currently available chemotherapeutic agents. Our previous studies have suggested that stromal components could promote the chemoresistance of pancreatic cancer cells (PCCs). Here, we explored the roles of pancreatic stellate cells (PSCs) and the SDF-1α/CXCR4 axis in pancreatic cancer chemoresitance. Our results showed that primary PSCs typically expressed SDF-1α, whereas its receptor CXCR4 was highly expressed in PCCs. PSC-conditioned medium (PSC-CM) inhibited Gemcitabine (GEM)-induced cytotoxicity and apoptosis in the human PCC line Panc-1, which was antagonized by an SDF-1α neutralizing Ab. Recombinant human SDF-1α (rhSDF-1α) increased IL-6 expression and secretion in Panc-1 cells in a time and dose-dependent manner, and this effect was suppressed by the CXCR4 antagonist AMD3100. rhSDF-1α protected Panc-1 cells from GEM-induced apoptosis, and the protective effect was significantly reduced by blocking IL-6 using a neutralizing antibody. Moreover, rhSDF-1α increased FAK, ERK1/2, AKT and P38 phosphorylation in Panc-1 cells, and either FAK or ERK1/2 inhibition suppressed SDF-1α-upregulated IL-6 expression. SDF-1α-induced AKT activation was almost completely blocked by FAK inhibition. In conclusion, we demonstrate for the first time that PSCs promote the chemoresistance of PCCs to GEM, and this effect is mediated by paracrine SDF-1α/CXCR4 signaling-induced activation of the intracellular FAK-AKT and ERK1/2 signaling pathways and a subsequent IL-6 autocrine loop in PCCs. Our findings indicate that blocking the PSC-PCC interaction by inhibiting SDF-1α/CXCR4 signaling may be a promising therapeutic strategy for overcoming chemoresistance in pancreatic cancer.     

A role for protease-activated receptor-2 in pancreatic cancer cell proliferation

The protease-activated receptor-2 (PAR-2) is a G protein-coupled receptor that is cleaved and activated by trypsin and tryptase. The purpose of this study was to clarify the role of PAR-2 in proliferation of human pancreatic cancer cells. PAR-2 mRNA and protein expression were detected by RT-PCR and Western blotting in three cell lines, SW1990, Capan-2, and Panc-1. The PAR-2 agonist peptide, SLIGKV (25, 50 micro g/ml) and trypsin (10, 100 ng/ml) significantly increased cell proliferation. Enhancement of MAP kinase also was observed in cancer cells treated with SLIGKV and trypsin. In vivo, subcutaneous xenografted tumors showed significantly enhanced growth after treatment with SLIGKV. Tumor-associated trypsinogen (TAT) mRNA and protein expression was detected in SW1990 and Capan-2, suggesting autocrine trypsin production. PAR-2 activated by trypsin plays an important role in promoting proliferation of pancreatic cancer.     

SAHA,an HDAC inhibitor,overcomes erlotinib resistance in human pancreatic cancer cells by modulating E-cadherin

Pancreatic cancer is one of the most lethal cancers and remains a major unsolved health problem. Less than 20 % of patients are surgical candidates, and the median survival for non-resected patients is approximately 3 to 4 months. Despite the existence of many conventional cancer therapies, few targeted therapies have been developed for pancreatic cancer. Combination therapy using erlotinib and gemcitabine is an approved standard chemotherapy for advanced pancreatic cancer, but it has marginal therapeutic benefit. To try to improve the therapeutic outlook, we studied the efficacy of another combination treatment and the relevance to E-cadherin in human pancreatic cancer cells. We treated two human pancreatic cancer cell lines with the histone deacetylase inhibitor (HDACi) SAHA. Interestingly, in these Panc-1 and Capan1 cells, we observed that the expression levels of E-cadherin and phosphorylated EGFR were gradually upregulated after treatment with SAHA. Furthermore, these cells underwent induced cell death after exposure to the combination treatment of SAHA and erlotinib. In Panc-1 cells, overexpression of E-cadherin activated the phosphorylation of EGFR and increased the cell sensitivity to erlotinib. In Capan1 cells, knocking down E-cadherin decreased the expression of phosphorylated EGFR, and these cells did not respond to erlotinib. Therefore, we demonstrated the efficacy of the combined treatment with SAHA and erlotinib in human pancreatic cancer cells, and we determined that the increased efficacy was due, at least in part, to the effects of SAHA on the expression of E-cadherin. Our studies suggest that E-cadherin may be a potent biomarker for pancreatic cancer.     

Activation of the PI3K/Akt Pathway Mediates Bone Morphogenetic Protein 2-Induced Invasion of Pancreatic Cancer Cells Panc-1

Bone morphogenetic proteins (BMPs) signaling has an emerging role in pancreatic cancer. However, because of the multiple effects of different BMPs, no final conclusions have been made as to the role of BMPs in pancreatic cancer. In our studies, we have focused on bone morphogenetic protein 2(BMP-2) because it induces an epithelial to mesenchymal transition (EMT) and accelerates invasion in the human pancreatic cancer cell line Panc-1. It has been reported that the phosphatidylinositol 3-kinase (PI3K)/Akt pathway mediates invasion of gastric and colon cancer cells, which is unrevealed in pancreatic cancer cells. The objective of our study was to investigate whether BMP-2 mediated invasion might pass through the PI3K/Akt pathway. Our results show that expression of phosphorylation of Akt was increased by treatment with BMP-2, but not Noggin, a BMP-2 antagonist. Then pretreatment of Panc-1 cells with LY294002, an inhibitor of the PI3K/AKT pathway, significantly inhibited BMP-2-induced EMT and invasiveness. The data suggest that BMP-2 accelerates invasion of panc-1 cells via the PI3K/AKT pathway in panc-1 cells, which gives clues to searching new therapy targets in advanced pancreatic cancer.     

胰腺癌Panc-1细胞TFPI-2基因甲基化状态与其体内体外侵袭能力的关系

目的：探讨甲基化酶抑制剂5-氮杂-2＇-脱氧胞苷（5-aza-2-deoxycytidine,5-Aza-dC）对胰腺癌Panc-1细胞体内体外侵袭能力及裸鼠皮下移植肿瘤组织TFPI-2基因甲基化状态及表达的影响。方法：用不同浓度的5-Aza-dC处理胰腺癌Panc-1细胞。Transwell法测定各组Panc-1细胞的体外侵袭能力。将用药物处理过的各组Panc-1细胞分别接种于裸鼠皮下,观察各组成瘤率及肿瘤大小。用MSP及RT-PCR检测裸鼠移植瘤组织TFPI-2基因甲基化状态及TFPI-2基因mRNA表达情况。结果：与对照组相比,药物处理组Panc-1细胞体外侵袭能力明显下降,裸鼠成瘤率明显降低,第八周时,肿瘤体积明显低于对照组（P〈0.05）。与对照组相比,TFPI-2基因异常甲基化状态在药物处理组裸鼠移植瘤组织中得到逆转,药物处理组移植瘤TFPI-2基因mRNA重新表达,并呈剂量依赖性（P〈0.05）。结论：甲基化酶抑制剂5-氮杂-2＇-脱氧胞苷可能在一定程度上抑制人胰腺癌Panc-1细胞系的体内体外侵袭和生长能力,其机制可能与逆转TFPI-2基因高甲基化状态从而恢复其表达有关。     

TFPI-2基因对Panc-1细胞凋亡的影响

[目的]研究TFPI-2基因对胰腺癌细胞系Panc-1细胞增殖及凋亡的影响。[方法]测定Panc-1-TFPI-2、Panc-1-V和Panc-1-P三组细胞的生长曲线．DNA片段化实验检测细胞凋亡，并用流式细胞仪分析三组细胞的细胞增殖、细胞周期情况。[结果]Panc-1-TFPI-2细胞同Panc-1-V和Panc-1-P细胞相比，细胞生长缓慢，细胞生长受到抑制，被阻滞于G0～G1期；DNA片段化实验显示Panc-1-TFPI-2细胞呈现凋亡细胞特有的“梯状”条带．而Panc-1-V和Panc-1-P细胞无明显“梯状”条带：流式细胞仪分析显示早期Panc-1-TFPI-2细胞凋亡率（6．93％± 0．53％）较Panc-1-V（3．01％± 0．39％）和Panc-1-P细胞凋亡率（3．52％±0．41％）增加，有显著性差异（P〈0．05）。[结论]TFPI-2能够抑制胰腺癌细胞生长、诱导胰腺癌细胞凋亡．可能具有抑制肿瘤细胞增殖的作用。