KAI1 gene is differently expressed in papillary and pancreatic cancer:influence on metastasis

AIM To compare KAI1 in cancer of papilla ofVater and pancreas to evaluate whether there aredifferences in biologic behavior which mightaccount for prognosis.METHODS We compared the expression in 24papillay and 29 pancreatic cancers usingNorthern blot analysis,immunochemical assayand in situ hybridization,and investigatedwhether early diagnosis or molecular differencespredict the outcome in these tumor entities.RESULTS By Northern blot analysis there is nostatistical difference of KAI1 levels in normaland cancerous papilla.No association betweenKAI1 mRNA expression and tumor stage or tumordifferentiation was found in the tumors.Byimmunohistochemical assay,KAI1 staining incytoplasm of papillary cancer cells was similarto that of normal papillary cells.By in situhybridization,the results of KAI1 mRNAexpression in normal and cancerous papilla weresimilar to those with immunohistochemicalassay.The normal and cancerous pancreastissues were also analyzed by the methods usedin papillary samples.CONCLUSION Although the biologic roles of KAI1 have not been clarified, our results suggest that KAI1 may restrict the progression of malignant papillary cancer, but its expression might not have any effect on the characteristics of papillary tumor, whereas by the analysis of KAl1 gene, its reduced expression is closely related to the progression and metastases of pancreatic cancer.

Detection of k-ras gene point mutation in fine needle aspiration and pancreatic juice by sequence special primer method and its clinical significance

INTRODUCTIONThe point mutation rate of k-ras gene at codon 12 inpancreatic adenocarcinoma is reported to be as highas 90%,and with no mutations in normalpancreas tissues or other pancreatic disorders.Wehave detected the presence of k-ras gene

Epigenetic changes of pituitary tumor-derived transforming gene 1 in pancreatic cancer

BACKGROUND: Pancreatic cancer is a devastating disease with abnormal genetic changes. The pituitary tumor-derived transforming gene (PTTG) is considered to be implicated in the tumorigenesis of cancers when the gene is epigenetically transformed. In this study, we investigated the relationships between aberrant expression and epigenetic changes of the PTTG1 gene in pancreatic cancer. METHODS: We chose 4 cell lines (PANC-1, Colo357, T3M-4 and PancTu I) and pancreatic ductal adenocarcinoma (PDAC) tissues. After using restriction isoschizomer endonucleases (Msp I /Hpa II) to digest the DNA sequence (5'-CCGG-3'), we performed PCR reaction to amplify the product. And RT-PCR was applied to determine the gene expression. RESULTS: The mRNA expression of the PTTG1 gene was higher in pancreatic tumor than in normal tissue. The gene was also expressed in the 4 PDAC cell lines. The methylation states of the upstream regions of the PTTG1 gene were almost identical in normal, tumor pancreatic tissues and the 4 PDAC cell lines. Some (5'-CCGG-3') areas in the upstream region of PTTG1 were methylated, while some others were unmethylated. CONCLUSIONS: The oncogene PTTG1 was overexpressed in pancreatic tumor tissues and verified by RT-PCR detection. The methylation status of DNA in promoter areas was involved in the gene expression with the help of other factors in pancreatic cancer.

Correlation between ECT2 gene expression and methylation change of ECT2 promoter region in pancreatic cancer

BACKGROUND: Pancreatic cancer is closely related to epigenetic abnormality. The epithelial cell transforming sequence 2 gene (ECT2) plays a critical role in Rho activation during cytokinesis, and thus may play a role in the pathogenesis of pancreatic cancer. In this study, we investigated the relationships between aberrant expression and epigenetic changes of the ECT2 gene in pancreatic cancer. METHODS: Four cell lines (PANC-1, Colo357, T3M-4 and PancTu I) and pancreatic ductal adenocarcinoma (PDAC) tissues were used for mRNA detection. After restriction isoschizomer endonucleases (Msp I/Hpa II) were used to digest the DNA sequence (5'-CCGG-3'), PCR was made to amplify the product. And RT-PCR was applied to determine the expression of the gene. RESULTS: The mRNA expression of the ECT2 gene was higher in pancreatic tumor tissue than in normal tissue. The gene was also expressed in the 4 PDAC cell lines. The methylation states of the upstream regions of the ECT2 gene were almost identical in normal, tumor pancreatic tissues, and the 4 PDAC cell lines. Some of the 5'-CCGG-3' areas in the upstream region of ECT2 were methylated, while others were unmethylated. CONCLUSIONS: The oncogene ECT2 is overexpressed in pancreatic tumor tissues as verified by RT-PCR detection. The methylation status of DNA in promoter areas is involved in the gene expression, along with other factors, in pancreatic cancer.

Studies on the Relationship between Multidrug Resistance 1 Gene and Pancreatic Cancer

Objective: To study the relationship between the expressions of multidrug-resistance, 1 (mdr1) gene-coded mRNA and its product P-glycoprotein (P-gp) and biological characteristics of tumor cells in patients with previously untreated primary pancreatic cancer (PC) for guiding signi?cance to the clinical treatment. Methods: Expression of mdr1 mRNA and P-gp on para?n embedded sections was detected by in situ polymerase chain reaction (ISPCR) and immunohistochemistry correspondingly from 150 cases of normal and abnormal pancreatic tissues including 97, 32 and 21 cases of pancreatic cancer, pancreatitis and normal pancreatic tissues respectively. Results: Distributions of positive staining in mdr1 mRNA and P-gp were mainly found on the apical plasma membranes and in cytoplasms of endothelial duct cells in tumor and normal tissues. The positive staining rates of expression of the mdr1 mRNA and P-gp detected in all pancreatic tumors were signi?cantly higher than that in pancreatitis and normal tissues correspondingly (P <0.05). Moreover, higher expressions of mdr1 mRNA and P-gp in tumor cells were correlated with some biological characteristics of PC, such as the degree of di?erentiation, aggressiveness and TNM stage of tumors (P <0.05). However, there was no correlation between the rate of expression of mdr1 mRNA and P-gp and some clinical ?ndings including age, sex, location and tumor size. Conclusion: The expression of mdr1 gene was associated with “natural” multi-drug resistance in PC. There was an important guiding signi?cance between the detection of expression of mdr1 gene and prediction of the sensitivity to chemotherapy of PC. Meanwhile, it probably could be used as one of profoundly parameters to assess the degrees of di?erentiation and prognosis in PC.

The effect of adenovirus expressing wild-type p53 on 5-fluorouracil chemosensitivity is related to p53 status in pancreatic cancer cell lines

AIM:There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU). Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53 gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status. METHODS:Human pancreatic cancer cell lines Capan-1^(p53mut), Capan-2^(p53wt),FAMPAC^(p53mut),PANC1^(p53mut),and rat pancreatic cancer cell lines AS^(p53wt) and DSL6A^(p53null) were used for in vitro studies.Following infection with different ratios of Ad- p53-particles (MOI) in combination with 5-FU,proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining).In addition,DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivo studies. Tumor size,apoptosis (TUNEL) and survival were determined. RESULTS:Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53.In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU.Both in vitro and in vivo analyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU. CONCLUSION:Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function.These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.

molecular pathology of intraductal papillary mucinous neoplasms of the pancreas

Since the first description of intraductal papillary mucinous neoplasms(IPMNs)of the pancreas in the eighties,their identification has dramatically increased in the last decades,hand to hand with the improvements in diagnostic imaging and sampling techniques for the study of pancreatic diseases.However,the heterogeneity of IPMNs and their malignant potential make difficult the management of these lesions.The objective of this review is to identify the molecular characteristics of IPMNs in order to recognize potential markers for the discrimination of more aggressive IPMNs requiring surgical resection from benign IPMNs that could be observed.We briefly summarize recent research findings on the genetics and epigenetics of intraductal papillary mucinous neoplasms,identifying some genes,molecular mechanisms and cellular signaling pathways correlated to the pathogenesis of IPMNs and their progression to malignancy.The knowledge of molecular biology of IPMNs has impressively developed over the last few years.A great amount of genes functioning as oncogenes or tumor suppressor genes have been identified,in pancreatic juice or in blood or in the samples from the pancreatic resections,but further researches are required to use these informations for clinical intent,in order to better define the natural history of these diseases and to improve their management.

Pancreatic neuroendocrine tumors G3 and pancreatic neuroendocrine carcinomas: Differences in basic biology and treatment

In 2017 the World Health Organization revised the criteria for classification of pancreatic neuroendocrine neoplasms(p NENs) after a consensus conference at the International Agency for Research on Cancer. The major change in the new classification was to subclassify the original G3 group into well-differentiated pancreatic neuroendocrine tumors G3(p NETs G3) and poorly differentiated pancreatic neuroendocrine carcinomas(p NECs), which have been gradually proven to be completely different in biological behavior and clinical manifestations in recent years. In 2019 this major change subsequently extended to NENs involving the entire digestive tract. The updated version of the p NENs grading system marks a growing awareness of these heterogeneous tumors. This review discusses the clinicopathological, genetic and therapeutic features of poorly differentiated p NECs and compare them to those of well-differentiated p NETs G3. For p NETs G3 and p NECs(due to their lower incidence), there are still many problems to be investigated. Previous studies under the new grading classification also need to be reinterpreted. This review summarizes the relevant literature from the perspective of the differences between p NETs G3 and p NECs in order to deepen understanding of these diseases and discuss future research directions.

Peripancreatic paraganglioma:Lesson from a round table

We described the case of a peripancreatic paraganglioma(PGL)misdiagnosed as pancreatic lesion.Surgical exploration revealed an unremarkable pancreas and a large well-defined cystic mass originating at the mesocolon root.Radical enucleation of the mass was performed,preserving the pancreatic tail.Histologically,a diagnosis of PGL was rendered.Interestingly,two previously unreported mutations,one affecting the KDR gene in exon 7 and another on the JAK3 gene in exon 4 were detected.Both mutations are known to be pathogenetic.Imaging and cytologic findings were blindly reviewed by an expert panel of clinicians,radiologists,and pathologists to identify possible causes of the misdiagnosis.The major issue was lack of evidence of a cleavage plane from the pancreas at imaging,which prompted radiologists to establish an intraparenchymal origin.The blinded revision shifted the diagnosis towards an extrapancreatic lesion,as the pancreatic parenchyma showed no structural alterations and no dislocation of the Wirsung duct.Ex post,the identified biases were the emergency setting of the radiologic examination and the very thin mesocolon sheet,which hindered clear definition of the lesion borders.Original endoscopic ultrasonography diagnosis was confirmed,emphasizing the intrinsic limit of this technique in detecting large masses.Finally,pathologic review favored a diagnosis of PGL due to the morphological features and immonohistochemical profile.Eighteen months after tumor excision,the patient is asymptomatic with no disease relapse evident by either radiology or laboratory tests.Our report strongly highlights the difficulties in rendering an accurate preoperative diagnosis of PGL.

Pathological differential diagnosis of solid-pseudopapillary neoplasm and endocrine tumors of the pancreas

AIM:To investigate differential points of solid-pseudo-papillary neoplasm (SPN) of the pancreas and pancre-atic endocrine tumor (PET).METHODS:Ten cases of SPN and fourteen cases of PET were studied in this retrospective study. Clinical and pathologic features,immunostaining reactions and β-catenin gene mutations were analyzed.RESULTS:The mean age of SPN patients was 25.6 years and these patients had no specific symptoms. The mean diameter of the tumors was 11.0 cm,9/10 cases were cystic or a mixture of solid and cystic structures,and there was hemorrhage and necrosis on the cut surface in 8/10 (80%) cases. Characteristic pseudo-papillary structure and discohesive appearance of the neoplastic cells were observed in all 10 (100%) cases. The results of immunostaining showed that nuclear expression of β-catenin and loss of E-cadherin in all the cases,was only seen in SPN. Molecular studies discov-ered that 9/10 (90%) cases harbored a point mutation of exon 3 in β-catenin gene. On the other hand,the mean age of PET patients was 43.1 years. Eight of 14 cases presented with symptoms caused by hypoglyce-mia,and the other 6 cases presented with symptoms similar to those of SPN. The mean size of the tumors was 2.9 cm,most of the tumors were solid,only 3/14 (21%) were a mixture of solid and cystic structures,and macroscopic hemorrhage and necrosis were much less common (3/14,21%). Histologically,tumor cells were arranged in trabecular,acinar or solid patterns and demonstrated no pseudopapillary structure and discohesive appearance in all 14 (100%) cases. The results of immunostaining and mutation detection were completely different with SPN that membrane and cytoplastic expression of β-catenin without loss of E-cadherin,as well as no mutation in β-catenin gene in all the cases. CONCLUSION:Both macroscopic and microscopic features of SPN are quite characteristic. It is not difficult to distinguish it from PET. If necessary,immunos-taining of β-catenin and E-cadherin is quite helpful to make the differential diagnosis.

Detecting K-ras and p53 gene mutation from stool and pancreatic juice for diagnosis of early pancreatic cancer

OBJECTIVE: To explore new methods for the early diagnosis of pancreatic cancer through detection of K-ras and p53 mutations in pancreatic juice and stool. METHODS: 201 patients in PUMC Hospital from 1994 - 2000 and 60 control individuals were enrolled in this study. K-ras point mutation was detected by PCR-RFLP while p53 mutation was detected by PCR-SSCP. RESULTS: K-ras mutation was found in pancreatic juice in 87.8% (36/41) of pancreatic cancer patients and 23.5% (4/17) of benign pancreatic disease patients. In 261 stool specimens, amplification found mutations successfully in 235 patients (90%). K-ras mutation was found in stool in 88% (66/75) of pancreatic cancer patients, 51.1% (24/47) of benign pancreatic disease patients and 19.6% (9/46) of normal individuals. p53 mutation was found in pancreatic juice in 47.4% (18/38) of pancreatic cancer patients and 12.5% (2/16) of benign pancreatic disease patients. p53 mutation was found in stool in 37.1% (23/62) and 19.1% (4/21) of chronic pancreatitis patients. CONCLUSION: K-ras mutation in pancreatic juice has higher diagnosis sensitivity and specificity, and therefore may be used as a supplement in the diagnosis of pancreatic cancer. Detection of K-ras mutation combined with p53 mutation in stool can aid in the screening of pancreatic cancer.

Adenoviral mediated suicide gene transfer in the treatment of pancreatic cancer

OBJECTIVE: To determine the efficacy of adenovirus mediated suicide gene transduction combined with prodrug 5-fluorocytosine (5FC) as a therapeutic protocol for pancreatic cancer. METHODS: Cytosine Deaminase(CD) gene was cloned into pAdTrack-CMV-CD, pAdTrack-CMV-CD and pAdEasy-1 were recombined in bacteria. The newly recombined adenovirus (Ad)-CD containing green fluorescent protein (GFP) were packaged and propagated in 293 cells and purified by cesium chloride gradient centrifugation. Human pancreatic carcinoma cell line-Patu8988 was infected with this virus, then 5FC was added. XTT assay was used to estimate relative numbers of viable cells. In vivo model of pancreatic cancer was established by injecting 1.0 x 10(7) Patu8988 cells subcutaneously in Balb/c nude mice. When tumors were palpable, Ad-CD was injected into each tumor and 5FC was administered. RESULTS: Positive clones were selected using endonuclease to digest the recombinants and the concentration of viral liquids containing the CD gene was 2 x 10(11) pfu /ml. Significant cytotoxic activity as shown for 5FC in the CD gene transduced 8988 cell line, while little effect was found in the nontransduced pancreatic carcinoma cells. Antitumor effect was observed in Patu8988 xenograft nude mice with in situ CD gene transduction. CONCLUSIONS: CD gene mediated by adenovirus has high infectivity and may be useful for gene therapy in pancreatic carcinoma. These data demonstrate the use of an enzyme prodrug strategy in experimental pancreatic cancer.

儿童遗传性胰腺炎及其家系分析一例报道并文献复习

遗传性胰腺炎(HP)是一种罕见的常染色体遗传病,表现为胰腺炎反复发作,常并发3c型糖尿病(T3cDM),甚至导致胰腺癌的发生,影响患者的生活质量及预后。本文报道了1例由丝氨酸蛋白酶1(PRSS1)基因p.Val39Ala(V39A)突变导致的HP患儿,同时对其家系进行了分析,以期为临床医师诊治HP提供参考。

Relationship between single nucleotide polymorphisms in the deoxycytidine kinase gene and chemosensitivity of gemcitabine in six pancreatic cancer cell lines

Background Single nucleotide polymorphisms （SNPs） in the deoxycytidine kinase （dCK） gene are associated with chemosensitivity to nucleoside analogs. 2＇,2＇-Difluoro 2＇-deoxycytidine （gemcitabine） is a first-line nucleoside analog drug in the treatment of pancreatic cancer. However, the association between SNPs in the dCK gene and chemosensitivity to gemcitabine has not been fully established. Therefore, the present study aimed to investigate the relationship between SNPs in the dCKgene and chemosensitivity to gemcitabine in human pancreatic cancer cell lines.Methods Seven SNPs in the dCK gene were sequenced in six human pancreatic cancer cell lines. The chemosensitivity of these six cell lines to gemcitabine were evaluated in vitro with a Cell Counting Kit-8 （CCK-8） test.Inhibition rates were used to express the chemosensitivity of pancreatic cancer cell lines to gemcitabine.Results The genotype of the A9846G SNP in the dCKgene was determined in six human pancreatic cancer cell lines.The cell lines BxPC-3 and T3M4 carried the A9846G SNP genotype AG, whereas cell lines AsPC-1, Mia PaCa2, SW1990 and SU86.86 carried the GG genotype. Cell lines with the AG genotype （BxPC-3 and T3M4） were more sensitive to gemcitabine compared with cell lines with the GG genotype （AsPC-1, Mia PaCa2, SW1990 and SU86.86） and significantly different inhibition rates were observed between cell lines carrying the AG and GG genotypes （P 〈0.01）.Conclusions Variants in the A9846G SNP of the dCK gene were associated with sensitivity to gemcitabine in pancreatic cancer cell lines. The dCK A9846G SNP may act as a genetic marker to predict chemotherapy efficacy of gemcitabine in pancreatic cancer.

神经元表达发育下调基因9诊断胰腺癌及其对患者预后的预测价值

【目的】探讨神经元表达发育下调基因9(NEDD9)诊断胰腺癌及其预测患者预后的价值。【方法】80例在本院首次就诊并经手术中快速病理活检证实的胰腺癌患者,收集患者胰腺癌组织及癌旁正常组织,采用免疫组化及qPCR技术检测各组织NEDD9的表达情况,分析NEDD9与胰腺癌患者临床特征的关系,探讨NDEE9对胰腺癌患者临床预后的影响。【结果】胰腺癌组织中的NEDD9高表达率为71.25%,显著高于癌旁组织的51.25%(P<0.05),其NEDD9 mRNA水平(0.92±0.17)也显著高于癌旁正常组织(0.33±0.09),差异有统计学意义P<0.05);低表达NEDD9患者的临床分期(Ⅰ~Ⅱ期)、分化程度(高分化)显著优于高表达NEDD9患者,同时淋巴结转移率显著低于高表达患者(均P<0.05);随访结果显示,发生预后不良的患者NEDD9表达水平(1.21±0.31)显著高于预后良好组(0.73±0.25)(P<0.05);二元Logistic回归分析显示,高表达NEDD9是胰腺癌患者预后不佳的独立危险因素,其优势比为2.18(1.16~4.01)。【结论】NEDD9在胰腺癌组织中呈显著高表达,且与患者临床分期及病例分级有相关性,NEDD9高表达是胰腺癌患者预后不佳的独立危险因素。

胰液K-ras12密码子点突变检测对胰腺癌诊断的临床价值

目的 :探讨胰液中 K- ras 12密码子点突变对胰腺癌诊断的临床应用价值。 方法 :采用内镜下置鼻胰管方法收集 2 0例胰腺疾病的胰液标本 ,聚合酶链反应 -限制性片段长度多态性分析 (PCR- RFL P)检测胰液 K- ras基因第 12密码子点突变 ,与肿瘤标记物 CA 19- 9及 CEA检测结果比较。结果 :12例胰腺癌患者胰液标本中 K- ras突变率为 5 8.3% (7/ 12 ) ;8例慢性胰腺炎患者标本 K- ras突变率为 12 .5 % (1/ 8) ,胰腺癌胰液 K- ras基因突变检测的敏感性为 5 8.3% ,特异性为 87.5 % ,阳性预示值为 87.5 % ,阴性预示值为 5 8.3%。同一组病例以血清 CA19- 9>37U / m l、CEA >4 .5μg/ ml为阳性界值。胰腺癌血清CA19- 9、CEA阳性率分别为 5 8.3% (7/ 12 )、4 1.7% (5 / 12 )。结论 :K- ras基因突变与胰腺癌相关性好 ,胰液中 K- ras 12密码子突变率高 ,特异性强 ,为胰腺癌早期诊断的初步筛选提供了手段。

胰腺癌胰液差异蛋白质丝氨酸蛋白酶2在胰腺癌组织和细胞株中的表达

目的研究胰腺癌胰液差异蛋白质丝氨酸蛋白酶2(PRSS2)在胰腺癌组织和细胞株中的表达,为临床胰腺癌的早期诊断及治疗提供新靶点。方法在4株胰腺癌细胞株、20例胰腺癌组织及20例正常胰腺组织中,以PCR法检测PRSS2 mRNA的表达,并分析其与胰腺癌临床特征之间的关系。结果PRSS2在正常胰腺、胰腺癌组织和胰腺癌细胞株中均有表达,在胰腺癌和正常组织中的相对表达量(RQ值)分别为33.76(6.47,107.98)和3.74(0.96,28.83),前者明显高于后者(P<0.05);PRSS2在癌组织中的表达与肿瘤分化程度、肿瘤大小、肿瘤淋巴结转移、血清CA19-9水平、血清CEA水平均无相关性。结论胰腺癌胰液中的PRSS2可作为胰腺癌诊断的潜在肿瘤标志物;从胰液筛查差异蛋白质作为胰腺癌早期诊断的肿瘤标志物是可行的。

胰腺癌Bcl-2,P53蛋白表达和细胞凋亡

目的 探讨ｂｃｌ２ ，ｐ５３ 基因和细胞凋亡在胰腺癌发病机制中的作用以及它们之间相互关系．方法 应用ＡＢＣ 免疫组化技术检测５０ 例胰腺癌中Ｂｃｌ２ 和Ｐ５３ 蛋白表达，运用原位末端标记法观察肿瘤中细胞凋亡数量．结果 Ｐ５３ 蛋白表达阳性率为５４ ％ ，临床Ⅰ期阳性率（２６－７ ％ ）却显著低于Ⅱ期（６１－１ ％ ） 和Ⅲ＋ Ⅳ期（７０－６ ％ ，Ｐ＜ ０－０５） ；Ｂｃｌ２蛋白表达阳性率为６４ ％ ，临床Ⅰ期阳性率（９３－３ ％ ） ，显著高于Ⅱ期（５５－６ ％ ） 和Ⅲ＋ Ⅳ期（４７－１ ％ ，Ｐ＜ ０－０５） ；组织学Ⅲ级癌细胞中凋亡指数明显高于Ⅰ，Ⅱ级（ Ｐ＜ ０－０５） ，Ｂｃｌ２ 蛋白阴性病例中凋亡指数明显高于Ｂｃｌ２ 阳性者（ Ｐ＜ ０－０１） ．结论 Ｂｃｌ２ 是通过抑制细胞凋亡参与肿瘤的生长过程，Ｂｃｌ２和Ｐ５３ 蛋白表达之间 存在密切负相关（τ＝ － ０－１７４７ ，Ｐ＜ ０－０５） ．

IL-23基因修饰的树突细胞疫苗联合β-榄香烯对小鼠胰腺癌生长的影响

背景与目的:树突细胞(dendriticcells,DC)疫苗是目前最具应用潜能的治疗性疫苗,功能性细胞因子能显著增强DC的活性及其诱导的宿主抗肿瘤作用,利用细胞因子基因修饰DC是当今肿瘤免疫治疗中最活跃的领域。本研究探讨β-榄香烯联合白细胞介素-23(interleukin-23,IL-23)修饰的DC疫苗对胰腺癌小鼠的协同抗肿瘤作用。方法:克隆并构建IL-23基因真核双表达载体,转染DC并负载肿瘤抗原后制备成疫苗。将IL-23基因转染的DC疫苗、空质粒转染的DC疫苗、未转染的DC疫苗及对照生理盐水分别注射小鼠,体外观察各组小鼠脾脏T淋巴细胞IFN-γ及IL-4的分泌。体内观察β-榄香烯联合DC疫苗对荷胰腺癌小鼠肿瘤生长的抑制作用及对小鼠存活期的影响。结果:基因测序证实IL-23基因克隆及双表达载体构建成功,转染后DC共刺激分子MHC-Ⅰ和MHC-Ⅱ的表达增强。接种IL-23转染DC疫苗后小鼠的免疫防御能力显著增强,有效地延缓并防御接种肿瘤的发生。DC介导的免疫应答促进了IFN-γ生成型Th1细胞的产生,未转染DC疫苗组和空质粒转染DC疫苗组IL-4分泌量与IL-23转染的DC疫苗组比较差异有显著性(P<0.05);IL-23转染DC疫苗组IFN-γ的分泌与其他各组比较差异有显著性(P<0.01)。β-榄香烯联合IL-23转染DC疫苗组肿瘤生长受到显著抑制,该组小鼠存活期与DC组、NS对照组及β-榄香烯组比较差异有极显著性(P<0.01)。结论:IL-23修饰DC疫苗可强化宿主针对特异肿瘤的Th1及CTL的免疫应答,使宿主不仅产生防御性免疫反应而且增强自动免疫能力。β-榄香烯有一定的协同抗癌作用。

胰腺癌中p33^(ING1b)基因变化及其表达研究

目的 检测胰腺癌中p33ING1b蛋白表达及基因变化情况,以了解p33ING1b在肿瘤发生过程中的作用。方法 采用免疫组化、聚合酶链反应单链构象多态性技术(PCR SSCP)和杂合型缺失(LOH)技术,检测胰腺癌中p33ING1b表达及p33ING1b基因变化情况。结果 ING1b蛋白的阳性表达率为85% (34/40),SSCP显示在40例病例中仅1例突变,LOH率为60.9% (14/23)。结论 突变与缺失表达并不是p33ING1b的主要失活形式,染色体改变可能导致p33ING1b功能下降,从而引发肿瘤发生。