Elucidation of the relationship of BNIP3 expression to gemcitabine chemosensitivity and prognosis

AIM: To evaluate the significance of BNIP3 in the pathogenesis of pancreatic cancer, we analyzed the relationship between the expression of BNIP3 and survival rate of the patients with pancreatic cancer, or chemosensitivities in pancreatic cancer cell lines, particularly for gemcitabine, the first-line anti-tumor drug for pancreatic cancer.

METHODS: To compare the expression level of BNIP3 with the resistance to gemcitabine, eight pancreatic cancer cell lines were subjected to gemcitabine treatment and the quantitative real-time RT-PCR method was used to evaluate BNIP3 expression. Immunohistochemical analysis was also performed using 22 pancreatic cancer specimens to study relationship between BNIP3 expression and survival rate.

RESULTS: Although no significantly positive association between BNIP3 mRNA level and gemcitabine chemosensitivity was observed, pancreatic cancer cell lines that were sensitive to gemcitabine treatment tended to show high levels of BNIP3 expression. The converse, an absence of BNIP3 expression, was not correlated with gemcitabine resistance. We further compared the BNIP3 expression profiles of resected primary pancreatic cancer specimens with the prognosis of the patients, and found a tendency of favorable prognosis and low BNIP3 expression.

CONCLUSION: High levels of BNIP3 expression cannot be used as one of the predicting factors for gemcitabine chemosensitivity, and some yet to be known factors will have to fill the gap for the accurate prediction of pancreatic cancer chemosensitivity to gemcitabine. However, BNIP3 expression may have an impact on prediction of prognosis of patients with pancreatic cancer.

Application of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry for early detection of pancreatic cancer

Pancreatic cancer is a devastating and lethal disease. Early detection continues to be a serious, unsolved problem. However, proteomics is emerging as a powerful new tool for the diagnosis of pancreatic cancer. Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) is a new technique that allows for rapid high-throughput screening of protein expression in clinical samples. The progress and challenges in applying SELDI-TOF MS to protein biomarker discovery in pancreatic cancer are reviewed in this paper.

Is it relevant that intra-arterial chemotherapy may be effective for advanced pancreatic cancer?

Unresectable pancreatic cancers have an extremely dismal prognosis and chemoresistant nature. The treatment of pancreatic cancer is still problematic. Gemcitabine is a promising new agent that has been studied recently for palliation of advanced pancreatic cancer. However, the response rates have been highly variable, and are often irreproducible. To improve this low response rate, various treatments are needed because no standard treatment exists. Intra-arterial chemotherapy is considered to take advantage of the first pass effect of the drug, generating higher local drug concentrations in tumor cells with lower toxicity. Regional intra-arterial chemotherapy may provide high levels of cytostatic concentrations within the tumor and, simultaneously, a low rate of systemic side effects compared with systemic administration of anti-neoplastic drugs. Intra-arterial chemotherapy has been introduced as an alternative treatment for advanced pancreatic cancer. Further clinical trials of this method should be subjected to a prospective randomized controlled study for advanced pancreatic cancer.

Evaluation of clinical relevance of examining K-ras, p16 and p53 mutations along with allelic losses at 9p and 18q in EUS-guided fine needle aspiration samples of patients with chronic pancreatitis and pancreatic cancer

AIM: To establish an optimum combination of molecular markers resulting in best overall diagnostic sensitivity and specificity for evaluation of suspicious pancreatic mass.

METHODS: Endoscopic ultrasound (EUS)-guided fine needle aspiration cytology (FNA) was performed on 101 consecutive patients (63 males, 38 females, 60 ± 12 years; 81 with subsequently diagnosed pancreatic cancer, 20 with chronic pancreatitis) with focal pancreatic mass. Samples were evaluated on-site by an experienced cytopathologist. DNA was extracted from Giemsa stained cells selected by laser microdissection and the presence of K-ras, p53 and p16 somatic mutations was tested by cycling-gradient capillary electrophoresis (CGCE) and single-strand conformation polymorphism (SSCP) techniques. In addition, allelic losses of tumor suppressor genes p16 (INK4, CDKN2A) and DPC4 (MADH4, SMAD4) were detected by monitoring the loss of heterozygosity (LOH) at 9p and 18q, respectively.

RESULTS: Sensitivity and specificity of EUS-guided FNA were 75% and 85%, positive and negative predictive value reached 100%. The remaining 26% samples were assigned as inconclusive. Testing of molecular markers revealed sensitivity and specificity of 70% and 100% for K-ras mutations (P < 0.001), 24% and 90% for p53 mutations (NS), 13% and 100% for p16 mutations (NS), 85% and 64% for allelic losses at 9p (P < 0.001) and 78% and 57% for allelic losses at 18q (P < 0.05). When tests for different molecular markers were combined, the best results were obtained with K-ras + LOH at 9p (92% and 64%, P < 0.001), K-ras + LOH at 18q (92% and 57%, P < 0.001), and K-ras + LOH 9q + LOH 18q (96% and 43%, P < 0.001). When the molecular markers were used as complements to FNA cytology to evaluate inconclusive samples only, the overall sensitivity of cancer detection was 100% in all patients enrolled in the study.

CONCLUSION: EUS-guided FNA cytology combined with screening of K-ras mutations and allelic losses of tumor suppressors p16 and DPC4 represents a very sensitive approach in screening for pancreatic malignancy. Molecular markers may find its use particularly in cases where FNA cytology has been inconclusive.

Angiotensin-II administration is useful for the detection of liver metastasis from pancreatic cancer during pharmacoangiographic computed tomography

AIM: To improve the preoperative diagnosis of liver metastasis from pancreatic cancer, we estimated computed tomography during arterial angiography (CTA) with/without administration of angiotensin-II (AT-II).

METHODS: Thirty-five patients with pancreatic cancer were examined in this study. After conventional CTA was performed, pharmacoangiographic CTA was performed with a 1-3 microgram/5 mL solution of angiotensin  IIinjected through a catheter into the celiac artery during spiral computed tomography. We prospectively analyzed the relative region of interest (ROI) ratio of tumor to liver with/without AT-II.

RESULTS: In all patients, the relative ratio of each computed tomography (CT) number in the ROI was larger at pharmacoangiographic CT than at conventional angiographic CT. Administration of angiotensin-II enhanced the metastatic liver tumor as compared with normal tissue. Intratumoral blood flow increased in all patients with malignant tumors due to the pressure effect of AT-II. Furthermore, the metastatic lesions in the liver of three patients were represented by only pharmacoangiographic CT, not by conventional CT and conventional CT angiography. In even peripheral and central areas of metastatic liver tumor, the lesions were enhanced after administration of AT-II.

CONCLUSION: These results support that high detection rate of liver metastasis revealed by pharmacoangiographic CT suggests the improvement of diagnosis on preoperative staging. Moreover, chemotherapy under AT-II induced hypertension may have a better effect on the treatment of metastatic liver tumors.

Progress in the clinical application of in patients with pancreatic cancer

Pancreatic cancer, which has high morbidity, difficult diagnosis, and poor treatment results, is a type of malignant tumor in the digestive system. Positron emission tomography-computed tomography, an important imaging modality in modern medicine, combines the functional imaging of PET and the anatomic imaging of CT to efficiently image tumor metabolism, proliferation, hypoxia and cell apoptosis. It can also precisely image the anatomic structure of tumors and their adjacent organs or tissues. Positron emission tomography-computed tomography was found to be particularly helpful for guiding diagnosis and therapy, the staging and grading of tumors, monitoring therapy and in evaluating the prognosis of patients with pancreatic cancer.

Impact of preoperative chemoradiotherapy on survival in patients with resectable pancreatic cancer

AIM: To explore whether preoperative chemoradiation therapy improves survival of patients with pancreatic cancer undergoing resectional surgery.

METHODS: Forty-seven patients with a malignant pancreatic tumor localized in the head or uncinate process of the pancreas underwent radical pancreatico-duodenectomy. Twenty-two received chemoradiation therapy (gemcitabine and radiation dose 50.4 Gy) before surgery (CRR) and 25 patients underwent surgery only (RO). The study was non-randomised. Patients were identified from a prospective database.

RESULTS: The median survival time was 30.2 mo in the CRR group and 35.9 mo in the RO group. No statistically significant differences were found in subclasses according to lymph node involvement, TNM stages, tumor size, or perineural invasion. The one, three and five year survival rates were 81%, 33% and 33%, respectively, in the CRR group and 72%, 47% and 23%, respectively, in the RO group. In ductal adenocarcinoma, the median survival time was 27 mo in the CRR group and 20 mo in the RO group. No statistically significant differences were found in the above subclasses. The one, three and five year survival rates were 79%, 21% and 21%, respectively, in the CRR group and 64%, 50% and 14%, respectively, in the RO group. The overall hospital mortality rate was 2%. The morbidity rate was 45% in the CRR group and 32% (NS) in the RO group.

CONCLUSION: Major multicenter randomized studies are needed to conclusively assess the impact of neoadjuvant treatment in the management of pancreatic cancer.

Effect of AG490 combined with gemcitabine on the growth of human pancreatic cancer cells

AIM: To investigate the effect of Janus kinase (JAK) specific inhibitor AG490 combined with gemcitabine on the proliferation of human pancreatic cancer cell line SW1990 and STAT3 signal transduction pathway as well as their mechanisms.

METHODS: Human pancreatic cancer cell line SW1990 was divided into control group, AG490-treated group, gemcitabine-treated group and AG490 + gemcitabine-treated group. After 48 h, the proliferation of SW1990 cells was detected by MTT assay. Flow cytometry was used to examine cell apoptosis. The expression of STAT3, Cyclin D1, Bcl-xL and Bax were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively.

RESULTS: The proliferation of SW1990 cells was significantly lower in AG490 or gemcitabine group than that in control group (2.20 ± 0.25, 2.30 ± 0.220 vs 3.78 ± 0.42, P < 0.05), but the apoptosis rate was markedly higher (35.40% ± 3.08%, 34.64% ± 1.38% vs 16.49% ± 1.45%, P < 0.05). Moreover, the proliferation (1.49 ± 0.15) and apoptosis (43.80% ± 1.57%) had notable difference between AG490+gemcitabine group and AG490 or gemcitabine group. After 48 h, AG490 remarkably down-regulated the expression of p-STAT3 (13.83% ± 0.64% vs 79.87% ± 1.43%, P < 0.05), and the expression of Cyclin D1 (mRNA: 15.63% ± 0.59% vs 43.83% ± 0.64%, P < 0.05; protein: 17.50% ± 0.92% 49.87% ± 1.27%, P < 0.05), Bcl-xL (mRNA: 13.93% ± 0.21% vs 75.70% ± 0.46%, P < 0.05; protein: 34.17% ± 1.70% vs 83.93% ± 0.80%, P < 0.05) and Survivin (mRNA: 58.27% ± 0.42% vs 82.93% ± 1.68%, P < 0.05; protein: 13.23% ± 1.03% vs 18.60 ± 1.08%, P < 0.05) were also decreased in comparison with that in control group; however, Bax expression was increased (mRNA: 10.33% ± 1.18% vs 5.43% ± 0.70%, P < 0.05; protein: 13.07% ± 1.04% vs 6.23% ± 2.40%, P < 0.05). There was no difference between gemcitabine and control group.

CONCLUSION: Blockade of STAT3 signal pathway inhibits the proliferation and promotes the apoptosis of SW1990 cells. AG490 combined with gemcitabine shows a synergic effect, which provides a new therapeutic approach for pancreatic cancer therapy.

Research progress in screening biomarkers of pancreatic cancer by proteomic techniques

Pancreatic cancer is one kind of devastating diseases. Those patients without nonspecific symptoms at early stage had mostly lost the opporunity of surgical therapy when pancreatic cancer was detected at advanced stage. Rapid growth of proteomic technologies provides possibilities to study etiopathogenesis, and screen early diagnostic and prognosis biomarkers of pancreatic cancer. In this paper, the application of proteomic techniques in cell lines, tissues, serum and pancreatic juice from patients with pancreatic cancer is reviewed briefly.

Clinical significance of main pancreatic duct dilation on computed tomography: Single and double duct dilation

AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic cancer, and to avoid unnecessary work up for patients at low risk of such diseases.

METHODS: Patients with dilation of the main pancreatic duct on CT at Emory University Hospital in 2002 were identified by computer search. Clinical course and ultimate diagnosis were obtained in all the identified patients by abstraction of their computer database records.

RESULTS: Seventy-seven patients were identified in this study. Chronic pancreatitis and pancreatic cancer were the most common causes of the main pancreatic duct dilation on CT. Although the majority of patients with isolated dilation of the main pancreatic duct (single duct dilation) had chronic pancreatitis, one-third of patients with single duct dilation but without chronic pancreatitis had pancreatic malignancies, whereas most of patients with concomitant biliary duct dilation (double duct dilation) had pancreatic cancer.

CONCLUSION: Patients with pancreatic double duct dilation need extensive work up and careful follow-up since a majority of these patients are ultimately diagnosed with pancreatic cancer. Patients with single duct dilation, especially such patients without any evidence of chronic pancreatitis, also need careful follow-up since the possibility of pancreatic malignancy, including adenocarcinoma and intraductal papillary mucinous tumors, is still high.

Expression of p-STAT3 and E-cadherin in pancreatic cancer and their clinical significances

AIM: To investigate the expression of phospho-rylated signal transduction and activators of transcription-3 (p-STAT3) and E-cadherin as well as their correlations with the clinicopathological parameters in pancreatic cancer, and to reveal the role of STAT3 signal pathway in the invasion and metastasis of pancreatic cancer.

METHODS: Immunohistochemistry was used to detect the expression of p-STAT3 and E-cadherin in 34 cases of pancreatic cancer and 10 cases of normal pancreatic tissues. Cell invasion assay kit was used to examine the invasion ability of pancreatic cancer cells SW1990 and CaPan-2. Western blot and electrophoretic mobility shift assay (EMSA) were applied to detect the protein expression of p-STAT3 and STAT3 DNA-binding activity in SW1990 and CaPan-2 cells.

RESULTS: Immunohistochemistry revealed high expression of p-STAT3 (64.7%) but low expression of E-cadherin in pancreatic cancer. The expression of p-STAT3 was significantly correlated with the clinical stages (P = 0.017) and lymph node metastasis (P = 0.013), and the expression of E-cadherin was correlated with the pathological degrees (P = 0.002), clinical stages (P = 0.034) and lymph node metastasis (P = 0.019). There was a negative correlation between p-STAT3 and E-cadherin expression in pancreatic cancer (r = -0.537, P = 0.001). Cell invasion assay indicated a more invasive ability in SW1990 cells than that in CaPan-2 cells (P < 0.05). Finally, Western blot and EMSA showed that p-STAT3 protein level and STAT3 DNA-binding activity were significantly higher in SW1990 cells as compared with those in CaPan-2 cells (P < 0.05).

CONCLUSION: The expression of p-STAT3 is closely related to the invasion and metastasis of pancreatic cancer and abnormal expression of E-cadherin. The combined detection for these two proteins may be useful in determining of the metastasis potency of pancreatic cancer.

Epidermal growth factor-mediated nuclear factor kappa B activation induces urokinase plasminogen activator expression and invasion, metastasis of pancreatic cancer cells

AIM: To investigate the effect of epidermal growth factor (EGF) on the adhesion, prolifera-tion, and invasion as well as the expression of nuclear factor kappa B (NF-κB) and urokinase plasminogen activator (uPA) of pancreatic cancer cell line KP4.

METHODS: The invasion, adhesion and proliferation of pancreatic cancer cell line KP4 were examined by the corresponding test, respectively. Western blot, reverse transcriptase-polymerase chain reaction (RT-PCR) and electrophoretic mobility shift assay (EMSA) were used to investigate NF-κB activity and uPA expression. The changes of NF-κB activity, uPA expression and invasion of tumor cells were observed as pyrrolidine dithiocarbamate (PDTC), a NF-κB inhibitor, was used.

RESULTS: EGF significantly increased the invasion of KP4 cells in a concentration-dependent way (50, 25, 5 mg/L vs 0 mg/L: 116 ± 13, 97 ± 10, 83 ± 7 vs 72 ± 5; t = 3.552, 3.018, 2.373; P = 0.006, 0.015, 0.042), but did not affect the proliferation or adhesion of the cells. NF-κB activity was obviously enhanced with the increasing of EGF concentration. EGF up-regulated the expression of uPA at both mRNA and protein levels in a dose-dependent manner. In addition, pretreatment with PDTC markedly attenuated EGF-induced NF-κB activity, uPA expression as well as invasion of pancreatic cancer cells.

CONCLUSION: EGF can induce uPA expression by NF-κB activation, which accelerates the invasion and metastasis of pancreatic cancer cells.

Detection of disseminated pancreatic cells by amplification of cytokeratin-19 with quantitative RT-PCR in blood, bone marrow and peritoneal lavage of pancreatic carcinoma patients

AIM: To evaluate the diagnostic potential of cytokeratin-19 (CK-19) mRNA for the detection of disseminated tumor cells in blood, bone marrow and peritoneal lavage in patients with ductal adenocarcinoma of the pancreas.

METHODS: Sixty-eight patients with pancreatic cancer (n = 37), chronic pancreatitis (n = 16), and non-pancreatic benign surgical diseases (n = 15, control group) were included in the study. Venous blood was taken preoperatively, intraoperatively and at postoperative d 1 and 10. Preoperative bone marrow aspirates and peritoneal lavage taken before mobilization of the tumor were analyzed. All samples were evaluated for disseminated tumor cells by CK-19-specific nested-PCR and quantitative fluorogenic RT-PCR.

RESULTS: CK-19 mRNA expression was increased in 24 (64%) blood samples and 11 (30%) of the peritoneal lavage samples in the patients with pancreatic cancer. In 15 (40%) of the patients with pancreatic cancer, disseminated tumor cells were detected in venous blood and bone marrow and/or peritoneal lavage. In the peritoneal lavage, the detection rates were correlated with the tumor size and the tumor differentiation. CK-19 levels were increased in pT3/T4 and moderately/poorly differentiated tumors (G2/G3). Pancreatic cancer patients with at least one CK-19 mRNA-positive sample showed a trend towards shorter survival. Pancreatic cancer patients showed significantly increased detection rates of disseminated tumor cells in blood and peritoneal lavage compared to the controls and the patients with chronic pancreatitis.

CONCLUSION: Disseminated tumor cells can be detected in patients with pancreatic ductal adenocar-cinoma by CK-19 fluorogenic RT-PCR. In peritoneal lavage, detection rate is correlated with tumor stage and differentiation. In the clinical use, CK-19 is suitable for the distinction between malignant and benign pancreatic disease in combination with other tumor-specific markers.

Importance of performance status for treatment outcome in advanced pancreatic cancer

Despite progress in the treatment of advanced and metastatic pancreatic cancer (PC), the outcome of this disease remains dismal for the majority of patients. Given the moderate efficacy of treatment, prognostic factors may help to guide treatment decisions. Several trials identified baseline performance status as an important prognostic factor for survival. Unfit patients with a Karnofsky performance status (KPS) below 70% only have a marginal benefit from chemotherapy with gemcitabine (Gem) and may often benefit more from optimal supportive care. Once, however, the decision is taken to apply chemotherapy, KPS may be used to select either mono- or combination chemotherapy. Patients with a good performance status (KPS = 90%-100%) may have a significant and clinically relevant survival benefit from combination chemotherapy. By contrast, patients with a poor performance status (KPS ≤ 80%) have no advantage from intensified therapy and should rather receive single-agent treatment.

Impact of endoscopic ultrasound-guided fine needle biopsy for diagnosis of pancreatic masses

AIM: To evaluate the diagnostic accuracy of histological evaluation of pancreatic tissue samples obtained by a modified method for recovering and processing the endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) material in the differential diagnosis of pancreatic solid masses.

METHODS: Sixty-two consecutive patients with pancreatic masses were prospectively studied. EUS was performed by the linear scanning Pentax FG-38UX echoendoscope. Three FNAs (22G needle) were carried out during each procedure. The materials obtained with first and second punctures were processed for cytological study. Materials of the third puncture were recovered into 10% formol solution by careful injection of saline solution through the needle, and processed for histological study.

RESULTS: Length of the core specimen obtained for histological analysis was 6.5 ± 5.3 mm (range 1-22 mm). Cytological and histological samples were considered as adequate in 51 (82.3%) and 52 cases (83.9%), respectively. Overall sensitivity of both pancreatic cytology and histology for diagnosis of malignancy was 68.4%. Contrary to cytology, histology was able to diagnose tumours other than adenocarcinomas, and all cases of inflammatory masses. Combination of cytology and histology allowed obtaining an adequate sample in 56 cases (90.3%), with a global sensitivity of 84.21%, specificity of 100% and an overall accuracy of 90.32%. The complication rate was 1.6%.

CONCLUSION: Adequate pancreatic core specimens for histological examination can be obtained by EUS-guided FNA. This technique is mainly useful for the diagnosis of different types of pancreatic tumours and evaluation of benign diseases.

The effect of wild type P53 gene transfer on growth properties and tumorigenicity of PANC-1 tumor cell line

BACKGROUND

The p53 protein function is essential for the maintenance of the nontumorigenic cell phenotype. Pancreatic tumor cells show a very high frequency of p53 mutation. To determine if restoration of wild type p53 function can be used to eliminate the tumorigenic phenotype in these cells, pancreatic tumor cell lines, PANC-1 and HTB80, differing in p53 status were stably transfected with exogenous wild type p53 gene.

METHODS

The transfection was performed using Polybrene/DMSO-Assisted Gene Transfer method. The wild type p53 gene integration into genomic DNA was detected by Southern blot and PCR. Furthermore, the expression of wild type p53 protein was detected in selected clones by immunohistochemistry and Western blot.

RESULTS

While HTB80 cell line failed to produce a stable p53 expressing clone, the PANC-1 cells produced stable lines. Following characterization of clones, the growth rate and tumorigenicity of PANC-1 wild type p53 clones were compared to the control cells. Our data showed that the expression of wild type p53 decreased the growth rate of PANC-1 cells. It was also observed that the expression of wild type p53 in PANC-1 cells suppressed its potential for tumor formation in nude mice, completely, while the parental line leads to the formation of a relatively large tumor.

CONCLUSION

Our results suggest that gene therapy based on restoration of wild type p53 protein function in pancreatic tumor cells with high amount of mutant p53 is a feasible option in pancreatic cancer treatment.

Osteoclast-like giant cell tumors of the pancreas and liver

Osteoclast-like giant cell tumors (OGCT) are rare abdominal tumors, which mainly occur in the pancreas. The neoplasms are composed of two distinct cell populations and frequently show an inhomogenous appearance with cystic structures. However, due to the rarity of these tumors, only very limited clinical data are available. Imaging features and sonographic appearance have hardly been characterized. Here we report on two cases of osteoclast-like giant cell tumors, one located within the pancreas, the other within the liver, in which OGCTs are extremely rare. Both patients were investigated by contrast sonography, which demonstrated a complex, partly cystic and strongly vascularized tumor within the head of the pancreas in the first patient and a large, hypervascularized neoplasm with calcifications within the liver in the second patient. The liver OGCT responded well to a combination of carboplatin, etoposide and paclitaxel. With a combination of surgical resection, radiofrequency ablation and chemotherapy, the patient’s survival is currently more than 15 mo, making him the longest survivor with an OGCT of the liver to date.

Efficacy of recombinant Canstatin protein plus fluorouracil in treatment of pancreatic cancer

AIM: To study the anti-tumor effects of recombinant Canstatin protein plus 5-fluorouracil (5-FU) on pancreatic cancer in order to develop a new treatment modality.

METHODS: Tumor xenografts were established by subcutaneous inoculation of 1×10⁷ SW1990 pancreatic cancer cells into the right flanks of 32 BALB/c nude mice. When the tumors reached 2-3 mm in diameter, mice were randomly divided into 4 groups: phosphate buffer solution (PBS) group were treated with PBS 0.3 mL per day for 3 weeks; Canstatin group were treated with Canstatin 5 mg/kg per day for 3 weeks; 5-FU group were treated with 5-FU 12.5 mg/kg per day for 5 days; and combination group were treated with 5-FU 12.5 mg/kg per day for 5 days plus Canstatin 5 mg/kg per day for 3 weeks. All the agents were injected intraperitoneally. During the treatment period, the subcutaneous tumors were measured by compasses and caliper every 3 or 4 days. At the end of the experiment, all the tumors were resected, and both routine pathological and immunohistochemical examinations were performed to observe the drug toxicity and intratumoral microvescular density (MVD)

RESULTS: The size of tumors treated with Canstatin was significantly decreased in comparison with that of PBS group from the 10^th day after treatment (P < 0.01). In 5-FU group, the tumor size was obviously smaller than that in PBS group from the 7^th day after treatment (P < 0.05), and in combination group from the 3^rd day after treatment (P < 0.05). At the end of the experiment, the size of tumors in combination group was the lowest (P < 0.05), with the highest tumor suppression rate of 83.2%. During treatment, no obvious toxicity was observed. The immunohistochemical examination showed that the MVD in Canstatin group (25.2 ± 3.7) or combination group (22.0 ± 4.8) was significantly lower than that in PBS group (36.8 ± 9.4) or 5-FU group (31.6 ± 4.0)(P < 0.05). No significant difference was found in MVD between 5-FU and PBS group.

CONCLUSION: Recombinant human Canstatin protein effectively retards the growth of pancreatic cancer through inhibiting the angiogenesis of tumors, without remarkable adverse effects. Synergic anti-tumor effect is achieved as Canstatin is combined with cytotoxic drugs.

The genetics of nicotine dependence: Relationship to pancreatic cancer

Smoking of tobacco products continues to be a major cause of worldwide health problems. Epidemiological studies have shown that tobacco smoking is the greatest risk factor for the development of pancreatic cancer. Smokers who are able to quit smoking can reduce their risk of pancreatic cancer by nearly 50% within two years, however, their risk of developing pancreatic cancer remains higher than that of non-smokers for 10 years. Nicotine is the major psychoactive substance in tobacco, and is responsible for tobacco dependence and addiction. Recent evidence suggests that individuals have genetically based differences in their ability to metabolize nicotine, as well as genetic differences in the psychological reward pathways that may influence individual response to smoking initiation, dependence, addiction and cessation. Numerous associations have been reported between smoking behavior and genetic polymorphisms in genes that are responsible for nicotine metabolism. In addition, polymorphisms in genes that encode neurotransmitters and transporters that function in psychological reward pathways have been implicated in differences in smoking behavior. However, there is a large degree of between-study variability that demonstrates the need for larger, well-controlled case-control studies to identify target genes and deduce mechanisms that account for the genetic basis of inter-individual differences in smoking behavior. Understanding the genetic factors that increase susceptibility to tobacco addiction may result in more effective tobacco cessation programs which will, in turn, reduce the incidence of tobacco related disease, including pancreatic cancer.

Endoscopic biliary drainage for patients with unresectable pancreatic cancer with obstructive jaundice who are to undergo gemcitabine chemotherapy

AIM: To assess optimum endoscopic biliary drainage (EBD) in cases with unresectable pancreatic cancer in the era of gemcitabine (GEM).

METHODS: Thirty patients with unresectable pancreatic cancer, who presented with jaundice and underwent chemotherapy using GEM after EBD were included in this study (GEM group). Fifteen cases with the same clinical manifestation and stage of pancreatic cancer treated with EBD alone were also included as controls. A covered metallic stent (CMS) or a plastic stent (PS) was used for EBD. The mean survival time (MST) in each group, risk factors of survival time, type of stent used and associated survival time, occlusion rate of stent, patency period of stent, and risk factors of stent occlusion were evaluated.

RESULTS: MST in the GEM group was longer than that in the control (9.9 mo vs 6.2 mo). In the GEM group, the survival time was not different between those who underwent metallic stenting and those who underwent plastic stenting. Stent occlusion occurred in 60% of the PS group and 7% of the CMS group. The median stent patency in the PS-GEM group and the CMS-GEM group was 5 mo and 7.5 mo, respectively. Use of a PS was the only risk factor of stent occlusion.

CONCLUSION: A CMS is recommended in cases presenting with jaundice due to unresectable pancreatic cancer, since the use of a CMS makes it possible to continue chemotherapy using GEM without repetition of stent replacement.

Effects of recombinant human canstatin protein in the treatment of pancreatic cancer

AIM: To examine the effect of canstatin, a newly discovered endogenous inhibitor of angiogenesis, in the treatment of pancreatic cancer in vivo.

METHODS: The canstatin cDNA fragment was synthesized and amplified from the total RNA extracted from human placenta tissues by RT-PCR. The resulting product was firstly cloned into pUCm-T vector, then into plasmid pET-22b (+) and transformed into E. coli BL21. Isopropyl-1-thio-b-Dgalactopyran-oside (IPTG) was used to induce the expression of canstatin protein and affinity chromatography was used to purify the protein. To determine the activity of purified recombinant human canstatin (rhCanstatin), orthotopic xenograft human pancreatic cancer models were established. Human pancreatic cancer cells (SW1990) were injected into the pancreas of BALB/c nude mice. Twenty-four nude mice with orthotopic xenograft tumor were randomly divided into 3 groups 10 d after the inoculation, and were treated with PBS 0.3 mL, or canstatin 5 mg/kg, or 10 mg/kg per day for 3 wk intraperitoneally. When the experiment was over, all tumors were resected and the effects of rhCanstatin on tumor growth, microvessel density (MVD) were analyzed.

RESULTS: After IPTG induction, SDS-PAGE showed a new monomeric 24 kDa protein band. This protein was purified through affinity chromatography and refolded through dialysis with a final concentration of 60 mg/L. In orthotopic pancreatic cancer models, the final tumor volume in groups treated with PBS, canstatin 5 mg/kg, 10 mg/kg were 355.21 ± 39.54 mm³, 112.73 ± 10.47 mm³, and 61.75 ± 6.99 mm³ respectively. The immunohistochemical examination showed that the MVD in tumors treated with canstatin was significantly less than that in other group.

CONCLUSION: These findings demonstrate that the rhCanstatin effectively retards the growth of pancreatic cancer in a dose-dependent manner through inhibiting angiogenesis and may be a promising therapeutic agent for pancreatic cancer treatment in the clinic.

Lack of association between UGT1A7, UGT1A9, ARP, SPINK1 and CFTR gene polymorphisms and pancreatic cancer in Italian patients

AIM: To investigate simultaneously UGT1A7, UGT1A9, ARP, SPINK and CFTR genes to verify whether genetic polymorphisms predispose to the development of pancreatic cancer (PC).

METHODS: Genomic DNA of 61 pancreatic cancer patients and 105 healthy controls (HC) were analyzed. UGT1A7 genotyping was determined by PCR-RFLP analysis. Specific PCR and sequencing were used to analyze genetic variants of UGT1A9, ARP, SPINK1 and CFTR genes.

RESULTS: Four different alleles (*1: WT; *2: N129K and R131K; *3: N129K, R131K, and W208R; and *4: W208R) in UGT1A7 and three different alleles (*1: WT; *4: Y242X; and *5: D256N) in UGT1A9 were detected. All UGT1A polymorphisms were observed at similar frequency in PC patients and HC. Seven different alleles in ARP were found in PC patients and HC at similar frequency. The SPINK1 mutations N34S and P55S occurred in five PC patients with a prevalence (4.1%) not significantly different from that observed (2.0%) in HC. The only CFTRΔF508 mutation was recognized in three PC patients with a prevalence (4.9%) similar to HC.

CONCLUSION: UGT1A7, UGT1A9, ARP, SPINK1 and CFTR gene polymorphisms are not associated with PC in Italian patients.

Therapeutic effects of survivin antisense oligonucleotide on nude mice bearing human pancreatic carcinoma xenograft

AIM: To investigate the therapeutic effects of survivin antisense oligonucleotide (ASODN) on nude mice bearing human pancreatic carcinoma xenograft.

METHODS: The nude mouse model of pancreatic cancer was established using human pancreatic cancer cell line BxPC-3. The mice bearing tumor were intratumorally injected with survivin ASODN (40 g/200 L per mouse). The tumor size and volume were measured before and after injection. The pathological changes of tumor tissues were observed. The expression level of survivin mRNA was measured by reverse transcription-polymerase chain reaction (RT- PCR), and the activity of caspase-3 was evaluated using a caspase-3 assay kit. The expression of proliferating cell nuclear antigen (PCNA) and microvessel density (MVD) were detected by immunohistochemistry.

RESULTS: Twenty days after injection, the tumor volume and weight were significantly decreased in survivin ASODN group as compared with those in the control and SODN group (427.34 ± 12.44 mm³vs 703.56 ± 12.51, 687.59 ± 12.44 mm³, P < 0.01; 0.57 ± 0.06 g vs 1.16 ± 0.12, 1.07 ± 0.10 g, P < 0.01), and the tumor inhibition rate was 50.86%. The expression of survivin mRNA was decreased by 50%, while the caspase-3 activity was significantly higher in survivin ASODN group than that in the control and SODN group (0.040 ± 0.018 vs 0.006 ± 0.001, 0.007 ± 0.002, P < 0.01). The expression of PCNA and MVD were significantly lower in survivin ASODN group than those in the control and SODN group (28.33 ± 2.16 vs 35.17 ± 3.71, 34.33 ± 3.27, P < 0.01; 15.50 ± 3.08 vs 21.33 ± 2.94, 20.67 ± 2.16, P < 0.01). However, both expression of PCNA and MVD had no significant difference between the control and SODN group (P > 0.05).

CONCLUSION: Survivin ASODN can inhibit the growth of human pancreatic carcinoma xenograft in nude mouse through activating caspase-3 to induce apoptosis, and suppressing the proliferation of pancreatic cancer cells as well as the angiogenesis of carcinoma.

Pancreatic cancer with a high serum IgG4 concentration

Differentiation between autoimmune pancreatitis and pancreatic cancer is sometimes difficult. It has been reported that serum IgG4 concentrations are significantly elevated and particularly high (>135 mg/dL) in autoimmune pancreatitis. Measurement of serum IgG4 has become a useful tool for differentiating between autoimmune pancreatitis and pancreatic cancer. However, we present a 74-year-old female with a markedly elevated serum IgG4 (433 mg/dL) who underwent pancreaticoduodenectomy for pancreatic cancer. Elevated serum IgG4 levels continued after the resection. On histology, adenocarcinoma of the pancreas accompanied with moderate lymphoplasmacytic infiltration infiltrated the lower bile duct and duodenum, but there were no findings of autoimmune pancreatitis. Although a small metastasis was detected in one parapancreatic lymph node, regional lymph nodes were swollen. Abundant IgG4-positive plasma cells infiltrated the cancerous areas of the pancreas, but only a few IgG4-positive plasma cells were detected in the noncancerous areas. Pancreatic cancer cells were not immunoreactive for IgG4. An abundant infiltration of IgG4-positive plasma cells was detected in the swollen regional lymph nodes and in the duodenal mucosa. We believe that the serum IgG4 level was elevated in this patient with pancreatic cancer as the result of an IgG4-related systemic disease that had no clinical manifestations other than lymphadenopathy.

Autoimmune pancreatitis associated with a large pancreatic pseudocyst

Pancreatic cystic lesions comprise various entities with different histopathological characteristics and their differential diagnosis is often a challenge for clinicians. Autoimmune pancreatitis (AIP) is usually not considered in the differential diagnosis of cystic lesions, but often mimics the morphological aspects of pancreatic neoplasm. We report the case of a 64-year-old male patient with a cystic pancreatic head lesion (diameter 5 cm) and stenosis of the distal bile duct requiring repeated stenting. Because of the clinical presentation together with moderate elevation of serum CA19-9 and massive elevation of cyst fluid CA19-9 (122.695 U/L; normal range: < 37.0 U/L), the patient underwent explorative laparotomy and pylorus preserving partial pancreaticoduodenectomy. Histology revealed surprisingly AIP with an inflammatory pseudocyst. In conclusion, cyst fluid analysis of tumor markers and cyst fluid cytology lack high accuracy to clearly differentiate cystic pancreatic lesions. Although AIP is rarely associated with pseudocysts, the disease has to be considered in the differential diagnosis of cystic pancreatic lesions. Early examination of serum IgG, IgG₄ and auto-antibodies might save these patients from unnecessary endoscopical and surgical procedures.

Inhibitory effects of antisence haparanase gene on proliferation and invasion of human pancreatic cancer cell line SW1990 in vitro

AIM: To investigate the inhibitory effects of antisense heparanase gene on the proliferation and invasion of human pancreatic cancer cell line SW1990 in vitro.

METHODS: Human pancreatic cancer cell line SW1990 was transfected with the plasmid expressing antisense heparanase gene. Meanwhile, the empty vector and non-transfection group were designed. The cell cycle distribution was analyzed by flow cytometry; the protein expression of heparanase gene was detected by Western blot and immunohistochemistry, and the mRNA transcription level was assayed by reverse transcription-polymerase chain reaction (RT-PCR). The colony-forming unit assay was used to measure the ability of cell growth, and Transwell chamber model was employed to test the ability of cell invasion in vitro.

RESULTS: In comparison with the cells transfected with empty vector or without transfection, SW1990 cells transfected with antisense heparanase gene had a significant decrease in S-phase cell population (18.8% ± 2.5% vs 36.3% ± 2.2%, 33.2% ± 2.1%, both P < 0.01) and a marked increase in G1-phase cell population (66.0% ± 2.7% vs 30.7 ± 3.2%, 39.8% ± 4.9%, P < 0.01). The protein expression and mRNA transcription were decreased by 34.3% and 37.8% individually. The colony formation was largely decreased (12.2 ± 2.8 vs 30.8 ± 4.4, 28.3 ± 2.7, P < 0.01); and finally, the cells moved from the upper chamber into the lower one in Transwell chamber assay were less than those in the control groups (13.0 ± 3.5 vs 34.8 ± 5.8, 29.4 ± 5.6, P < 0.01).

CONCLUSION: Transfection of antisense heparanase gene can inhibit the ability of cell proliferation and invasion in human pancreatic cancer cell lines SW1990 in vitro.

Effect of gamma-aminobutyric acid on the growth of pancreatic cancer cell line SW1990

AIM: To investigate the effect of gamma-aminobutyric acid (GABA) on the growth of pancreatic cancer cell line SW1990.

METHODS: Pancreatic cancer cell line SW1990 was cultured by routine method, and then treated with different concentrations of GABA (20-320 μmol/L). The proliferation, apoptosis, and cell cycle of SW1990 cells was investigated by MTT assay and flow cytometry, respectively. Radioimmunoassay was used to measure the intracellular cyclic adenosine monophosphate (cAMP) content.

RESULTS: The different concentrations of GABA promoted the growth of SW1990 cells and affected the distribution of cell cycle. The percentage of cells in G₀/G₁ phase was decreased while that in S and G₂/M phase was increased. The content of intracellular cAMP was increased with the increase of GABA concentration in a dose-dependent manner (P < 0.01). The apoptosis rate of SW1990 cells was decreased from 27.5% to 5.4%, which had significant difference (χ² = 10.19, P <0.01).

CONCLUSION: GABA can promote the proliferation of SW1990 cells by inhibiting apoptosis and influencing the distribution of cell cycle, which may be mediated by the information transition of post-receptor.

Experimental study on microwave tissue coagulation of canine pancreas

AIM: To evaluate the feasibility and safety of microwave tissue coagulation to pancreas through the observation of physiological state and pathological changes after the coagulation of canine pancreas.

METHODS: Microwave tissue coagulation of fifteen healthy mongrel dogs' pancreas was performed hrough laparotomy. The power and time were set on 50 Watt and three minutes respectively. The 5 coagulated points were selected at an interval of 1 cm. The blood amylase and other parameters were examined regularly after the operation. The dogs were killed at the instant time (n = 5), the 1^st d (n = 5) and 1^st wk (n = 5) after the operation. Hematoxylin and eosin (HE) staining together with nicotinamide adenine dinucleotide (NADH) and TUNEL staining was used to observe the pathological changes.

RESULTS: The level of blood amylase increased immediately after the operation and the maximal value occurred within 48-72 h. Furthermore, it returned to normal level 1 wk later if no complications occurred. The segmental microwave lesions included hyperintense zone of coagulative necrosis and peripheral hypointense zone. Apoptosis was observed at the peripheral zone 1 d after the operation. The fibrosis and tissue absorption occurred finally 1 wk after the operation.

CONCLUSION: Microwave tissue coagulation is safe and feasible, and it may be used in the treatment of pancreatic cancer at the late stage.

Oncological problems in pancreatic cancer surgery

Despite the development of more sophisticated diagnostic techniques, pancreatic carcinoma has not yet been detected in the early stage. Surgical resection provides the only chance for cure or long-term survival. The resection rate has increased due to recent advances in surgical techniques and the application of extensive surgery. However, the postoperative prognosis has been poor due to commonly occurring liver metastasis, local recurrence and peritoneal dissemination. Recent molecular-biological studies have clarified occult metastasis, micrometastasis and systemic disease in pancreatic cancer. Several oncological problems in pancreatic cancer surgery are discussed in the present review.

Overexpression of c-met in the early stage of pancreatic carcinogenesis; altered expression is not sufficient for progression from chronic pancreatitis to pancreatic cancer

AIM: To investigate c-met expression during early pancreatic carcinogenesis.

METHODS: We used 46 bulk tissues and 36 micro-dissected samples, including normal pancreas, chronic pancreatitis, and pancreatic cancer, for quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS: In bulk tissue analyses, pancreatic cancer tissues expressed significantly higher levels of c-met than did chronic pancreatitis and normal pancreas tissues. c-met levels did not differ between chronic pancreatitis and normal pancreas tissues. In microdissection-based analyses, c-met was expressed at higher levels in microdissected pancreatic cancer cells and pancreatitis-affected epithelial cells than in normal ductal epithelial cells (both, P < 0.01). Interestingly, pancreatitis-affected epithelial cells expressed levels of c-met similar to those of pancreatic cancer cells.

CONCLUSION: Overexpression of c-met occurs during the early stage of pancreatic carcinogenesis, and a single alteration of c-met expression is not sufficient for progression of chronic pancreatitis-affected epithelial cells to pancreatic cancer cells.

Helicobacter species ribosomal DNA in the pancreas, stomach and duodenum of pancreatic cancer patients

AIM: To determine whether gastric and enteric Helicobacter species are associated with pancreatic cancer.

METHODS: Patients with exocrine pancreatic cancer (n = 40), neuroendocrine cancer (n = 14), multiple endocrine neoplasia type 1 (n = 8), and chronic pancreatitis (n = 5) were studied. Other benign pancreatic diseases (n = 10) and specimens of normal pancreas (n = 7) were included as controls. Pancreatic tissue specimens were analyzed by Helicobacter-specific PCR-assay and products were characterized by denaturing gradient electrophoresis and DNA-sequencing. From a subset of the pancreatic cancer patients, gastric and/or duodenal tissue as well as gallbladder and ductus choledochus tissue were analyzed. Gallbladder and choledochus samples were included as controls. Stomach and duodenum samples were investigated to analyze whether a gastric helicobacter might disseminate to the pancreas in pancreatic cancer patients. Pancreatic specimens were analyzed by Bacteroides-specific PCR for detecting the translocation of indigenous gut microbes to the diseased pancreas.

RESULTS: Helicobacter DNA was detected in pancreas (tumor and/or surrounding tissue) of 75% of patients with exocrine cancer, 57% of patients with neuroendocrine cancer, 38% of patients with multiple endocrine neoplasia, and 60% of patients with chronic pancreatitis. All samples from other benign pancreatic diseases and normal pancreas were negative. Thirty-three percent of the patients were helicobacter-positive in gastroduodenal specimens. Surprisingly, H. bilis was identified in 60% of the positive gastroduodenal samples. All gallbladder and ductus choledochus specimens were negative for helicobacter. Bacteroides PCR-assay was negative for all pancreatic samples.

CONCLUSION: Helicobacter DNA commonly detected in pancreatic cancer suggests a possible role of the emerging pathogens in the development of chronic pancreatitis and pancreatic cancer.

Role of multiple genes methylation in pancreatic carcinogenesis

AIM: To determine methylation status of RASSF1A, p16, SOCS-1 and hMLH1 genes and explore the roles of their concurrent methylation in the carcinogenesis of pancreatic cancer.

METHODS: DNA in pancreatic cancer and cancer-adjacent tissues was extracted by saturated NaCl method. The methylation status of these genes was detected by methylation-specific polymerase chain reaction (MSP).

RESULTS: The methylation rates of RASSF1A, p16, SOCS-1 and hMLH1 were 36.4%, 13.6%, 13.6% and 4.5% in cancer-adjacent tissues and 59.1%, 40.9%, 31.8% and 18.2% in pancreatic cancer, respectively. The methylation rate of p16 in pancreatic cancer was significantly higher than that in the cancer-adjacent tissues (χ² = 4.13, P < 0.05). Two or more genes concurrent methylation was found in 45.5% pancreatic cancer, significantly higher than that in the cancer-adjacent tissues (9.1%, χ² = 7.33, P < 0.01). No methylation of these genes was found in 31.8% pancreatic cancer.

CONCLUSION: Multiple genes concurrent methylation is an early event in some cases of pancreatic cancer, in which it plays an important role.

Down-regulation of survivin expression by small interfering RNA induces pancreatic cancer cell apoptosis and enhances its radiosensitivity

AIM: To investigate the inhibitory effect of small interfering RNA (siRNA) on the expression of survivin in pancreatic cancer cell line PC-2 and the role of siRNA in inducing PC-2 cell apoptosis and enhancing its radiosensitivity.

METHODS: A siRNA plasmid expression vector against survivin was constructed and transfected into PC-2 cells with Lipofectamine^TM 2000. The down regulation of survivin expression was detected by semi-quantitive RT-PCR and immunohistochemical SP method and the role of siRNA in inducing PC-2 cell apoptosis and enhancing its radiosensitivity was detected by flow cytometry.

RESULTS: The sequence-specific siRNA efficiently and specifically down-regulated the expression of survivin at both mRNA and protein levels. The expression inhibition ratio was 81.25% at mRNA level detected by semi-quantitive RT-PCR and 74.24% at protein level detected by immunohistochemical method. Forty-eight hours after transfection,apoptosis was induced in 7.03% cells by siRNA and in 14.58% cells by siRNA combined with radiation.

CONCLUSION: The siRNA plasmid expression vector against survivin can inhibit the expression of survivin in PC-2 cells efficiently and specifically. Inhibiting the expression of survivin can induce apoptosis of PC-2 cells and enhance its radiosensitivity significantly. RNAi against survivin is of potential value in gene therapy of pancreatic cancer.

Establishment of risk model for pancreatic cancer in Chinese Han population

AIM: To investigate risk factors for pancreatic cancer and establish a risk model for Han population.

METHODS: This population-based case-control study was carried out from January 2002 to April 2004. One hundred and nineteen pancreatic cancer patients and 238 healthy people completed the questionnaire which was used for risk factor analysis. Logistic regression analysis was used to calculate odds ratio (ORs), 95% confidence intervals (Cls) and β value, which were further used to establish the risk model.

RESULTS: According to the study, people who have smoked more than 17 pack-years had a higher risk to develop pancreatic cancer compared to non-smokers or light smokers (not more than 17 pack-years) (OR 1.98; 95% CI 1.11-3.49, P = 0.017). More importantly, heavy smokers in men had increased risk for developing pancreatic cancer (OR 2.11; 95%CI 1.18-3.78, P = 0.012) than women. Heavy alcohol drinkers (＞20 cup-years) had increased risk for pancreatic cancer (OR 3.68; 95%CI 1.60-8.44). Daily diet with high meat intake was also linked to pancreatic cancer. Moreover, 18.5% of the pancreatic cancer patients had diabetes mellitus compared to the control group of 5.8% (P = 0.0003). Typical symptoms of pancreatic cancer were anorexia, upper abdominal pain, bloating, jaundice and weight loss. Each risk factor was assigned a value to represent its importance associated with pancreatic cancer. Subsequently by adding all the points together, a risk scoring model was established with a value higher than 45 as being at risk to develop pancreatic cancer.

CONCLUSION: Smoking, drinking, high meat diet and diabetes are major risk factors for pancreatic cancer. A risk model for pancreatic cancer in Chinese Han population has been established with an 88.9% sensitivity and a 97.6% specificity.

Surgical treatment of patients with intermediate-terminal pancreatic cancer

AIM: To investigate the surgical treatment of patients with intermediate–terminal pancreatic cancer.

METHODS: A retrospective analysis was made of the clinical data of 163 patients with intermediate–terminal pancreatic cancer who were surgically treated between August 1994 and August 2003.

RESULTS: A total of 149 patients underwent palliative surgery. The mortality rate of those who underwent cholecystojejunostomy alone was 14.2%, the icterus or cholangitis recurrence rate was 61.9% with an average survival period of 7.1 mo. The mortality rate for those who received hepatic duct-jejunostomy (HDJS) was 5.7%, the icterus or cholangitis recurrence rate was 6.8% with an average survival period of 7.1 mo. But 31.8% of the patients developed duodenum obstruction within 6 mo after the surgery, six of seven patients with severe pain were given peri-abdominal aorta injection with absolute alcohol and their pain was alleviated. The other patients underwent percutaneous transhepatic cholangial drainage (PTCD) and their icterus index returned to normal level within 40 d with an average survival period of 7.5 mo.

CONCLUSION: Roux-en-y HDJS combined with prophylactic gastrojejunostomy is recommended for patients with intermediate–terminal pancreatic cancer, and biliary prosthesis can partly relieve biliary obstruction in a short term.

Differential c-erbB-1 and c-erbB-2 mRNA expression in cancer of the pancreas compared with cancer of the papilla of Vater

AIM: We examined quantitative mRNA expression of growth factor receptors (c-erbB-1, c-erbB-2) and the anti-apoptosis gene survivin known to be regulated in pancreatic adenocarcinomas and compared the expression pattern with that in carcinomas of the papilla of Vater.

METHODS: Quantitative real-time reverse transcriptase-PCR (QRT-PCR, Taqman^TM) was performed to analyze mRNA expression levels of c-erbB-1, c-erbB-2 and survivin in normal and corresponding tumor samples of 31 pancreatic adenocarcinomas and 8 cancers of the papilla of Vater.

RESULTS: The overall median mRNA expression of survivin was significantly increased in both adenocarcinoma of the pancreas (P<0.01) and papilla of Vater (P<0.008) compared with uninvolved normal control tissue. In pancreatic cancer, expression of c-erbB-1 was significantly decreased compared with the normal pancreatic tissue (P<0.03), whereas in the cancer of the papilla of Vater expression of c-erbB-2 was significantly downregulated (P<0.05) compared with the paired normal samples. Gene expression was not associated with tumor stage, differentiation or prognosis.

CONCLUSION: The common anti-apoptosis gene survivin is overexpressed both in the cancer of the papilla of Vater and pancreas. In contrast, the growth factor receptor genes c-erbB-1 and c-erbB-2 are differentially regulated in both tumor entities adding further evidence that pancreatic cancer is biologically different from the cancer of papilla of Vater.

Expression of vascular endothelial growth factors A and C in human pancreatic cancer

AIM: To study the expression of vascular endothelial growth factor A (VEGF - A) and VEGF - C and to determine whether the presence of VEGF - A and VEGF - C was associated with the clinicopathologic characteristics of pancreatic cancer.

METHODS: VEGF - A and VEGF - C mRNA transcripts were examined by Northern blot in 6 human pancreatic cancer cell lines and 8 normal pancreatic tissues and 8 pancreatic carcinoma specimens. The expression of VEGF - A and VEGF - C proteins was examined by Western blot in the tested cell lines and by immunohistochemical stain in 50 pancreatic carcinoma samples.

RESULTS: VEGF - A and VEGF - C mRNA transcripts were present in all the 6 human pancreatic cancer cell lines. Immunoblotting revealed the presence of VEGF - A and VEGF - C proteins in all the cell lines. Northern blot analysis of total RNA revealed 3.0-fold and 3.6 - fold increase in VEGF - A and VEGF - C mRNA transcript in the cancer samples, respectively. Immunohistochemical analysis confirmed the expression of VEGF - A and VEGF - C in cancer cells within the tumor mass. Immunohistochemical analysis of 50 pancreatic cancer tissue samples revealed the presence of VEGF-A and VEGF - C immunoreactivity in 50% and 80% of the cancer tissue samples, respectively. The presence of VEGF-A in these cells was associated with larger tumor size and enhanced local spread (χ²= 6.690, P = 0.035<0.05) but was not associated with decreased patient survival. However, the presence of VEGF-C in the cancer cells was associated with increased lymph node metastasis (χ²= 5.710, P  = 0.017<0.05), but was not associated with decreased patient survival. There was no correlation between the expression of VEGF - A and VEGF - C in the same cancer cells.

CONCLUSION: VEGF - A and VEGF-C are commonly overexpressed in human pancreatic cancer and may contribute to tumor growth and lymph node metastasis. There is no relationship between the expression of VEGF - A and VEGF - C in pancreatic cancer.

Contrast-enhanced endoscopic ultrasound in discrimination between focal pancreatitis and pancreatic cancer

AIM: To evaluate the contrast-enhanced endosonography as a method of differentiating inflammation from pancreatic carcinoma based on perfusion characteristics of microvessels.

METHODS: In 86 patients with suspected chronic pancreatitis (age: 62 ± 12 years; sex: f/m 38/48), pancreatic lesions were examined by conventional endoscopic B-mode, power Doppler ultrasound and contrast-enhanced power mode (Hitachi EUB 525, SonoVue^®, 2.4 mL, Bracco) using the following criteria for malignant lesions: no detectable vascularisation using conventional power Doppler scanning, irregular appearance of arterial vessels over a short distance using SonoVue^® contrast-enhanced technique and no detectable venous vessels inside the lesion. A malignant lesion was assumed if all criteria were detectable [gold standard endoscopic ultrasound (EUS)-guided fine needle aspiration cytology, operation]. The criteria of chronic pancreatitis without neoplasia were defined as no detectable vascularisation before injection of SonoVue^®, regular appearance of vessels over a distance of at least 20 mm after injection of SonoVue^® and detection of arterial and venous vessels.

RESULTS: The sensitivity and specificity of conventional EUS were 73.2% and 83.3% respectively for pancreatic cancer. The sensitivity of contrast-enhanced EUS increased to 91.1% in 51 of 56 patients with malignant pancreatic lesion and the specificity increased to 93.3% in 28 of 30 patients with chronic inflammatory pancreatic disease.

CONCLUSION: Contrast-enhanced endoscopic ultrasound improves the differentiation between chronic pancreatitis and pancreatic carcinoma.

Gene Expression and Proteomic Analysis of Pancreatic Cancer: a Recent Update

Pancreatic cancer is a lethal disease for which little progress in early diagnosis or treatment has been made for many decades. Better biomarkers are urgently needed for early detection while the cancer is potentially curable. Recently, expression profiling, including gene expression profiling and proteomic profiling, have demonstrated new opportunities to investigate crucial events underlying pancreatic tumorigenesis and to exploit this knowledge for early detection and better intervention. This review will discuss and compare recently published data on this topic.

Effect of hypoxia on apoptosis inhibitory protein 2 expression and its mechanism in pancreatic cancer cell line PC-3

AIM: To investigate the expression of apoptosis inhibitory protein 2 (IAP-2) in pancreatic cancer cell PC-3 under severe hypoxia, and to explore its relation with hypoxia inducible factor 1(HIF-1).

METHODS: PC-3 cells were cultured under different conditions as follows: normoxia; 20 mL/L O₂, 50 mL/L CO₂, and 930 mL/L N₂ for 4 h (hypoxia); 950 mL/L N₂ and 50 mL/L CO₂ for 1, 3, 5 h, respectively (severe hypoxia); reoxygenation after 1 h of severe hypoxia; normoxia with colalt chloride (300 µmol/L). Immunocytochemistry was used to qualitatively evaluate the expression of IAP-2 protein. After extraction of cytoplasmic and nuclear proteins, Western blot was used to quantitatively determine the expression of IAP-2 protein, which was compared with the expression of HIF-1 protein. Then the expression of IAP-2 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: IAP-2 protein was positively expressed in the cytoplasm of PC-3 cells. There was no significant difference between the expression levels of IAP-2 protein under normoxia and hypoxia. The expression of IAP-2 protein was markedly increased (t = 3.300, P <0.05) 1 h after severe hypoxia and remained high at 3 or 5 h. There was no significant difference among different time points (P <0.05). Reoxygenation led to basal expression of IAP-2 protein and mRNA. HIF-1 expression was undetectable in normoxic PC-3 cells, but it was induced by hypoxia. Under severe hypoxia, HIF-1 was modestly expressed, but IAP-2 was abundantly expressed. After reoxygenation, the expression of HIF-1 disappeared, and IAP-2 returned to the basal level. Colalt chloride activated HIF-1 but not IAP-2. One hour after severe hypoxia, the expression of IAP-2 mRNA was evidently higher than that under normoxia (t = 6.900, P <0.05) and remained high at 3, 5 h. There was no significant different among different time points (P >0.05).

CONCLUSION: Severe hypoxia induces the up-regulation of IAP-2 in PC-3 cells through HIF-1-independent pathways.

Angiostatin inhibits pancreatic cancer cell proliferation and growth in nude mice

AIM: To observe the biologic behavior of pancreatic cancer cells in vitro and in vivo, and to explore the potential value of angiostatin gene therapy for pancreatic cancer.

METHODS: The recombinant vector pcDNA3.1(+)-angiostatin was transfected into human pancreatic cancer cells PC-3 with Lipofectamine 2000, and paralleled with the vector and mock control. Angiostatin transcription and protein expression were determined by immunofluorescence and Western blot. The stable cell line was selected by G418. The supernatant was collected to treat endothelial cells. Cell proliferation and growth in vitro were observed under microscope. Cell growth curves were plotted. The troms-fected or untroms-fected cells overexpressing angiostatin vector were implanted subcutaneously into nude mice. The size of tumors was measured, and microvessel density count (MVD) in tumor tissues was assessed by immunohistochemistry with primary anti-CD34 antibody.

RESULTS: After transfected into PC-3 with Lipofectamine 2000 and selected by G418, macroscopic resistant cell clones were formed in the experimental group transfected with pcDNA 3.1(+)-angiostatin and vector control. But untreated cells died in the mock control. Angiostatin protein expression was detected in the experimental group by immunofluorescence and Western-blot. Cell proliferation and growth in vitro in the three groups were observed respectively under microscope. After treatment with supernatant, significant differences were observed in endothelial cell (ECV-304) growth in vitro. The cell proliferation and growth were inhibited. In nude mice model, markedly inhibited tumorigenesis and slowed tumor expansion were observed in the experimental group as compared to controls, which was parallel to the decreased microvessel density in and around tumor tissue.

CONCLUSION: Angiostatin does not directly inhibit human pancreatic cancer cell proliferation and growth in vitro, but it inhibits endothelial cell growth in vitro. It exerts the anti-tumor functions through antiangiogenesis in a paracrine way in vivo.

Clinicopathological significance of Bcl-2 and Bax protein expression in human pancreatic cancer

AIM: To assess the clinicopathological significance of the expression of the apoptosis-inhibitory Bcl-2 protein (pBcl-2) and the apoptosis-promoting Bax protein (pBax) in human invasive ductal carcinomas (IDCs) of the pancreas.

METHODS: Fifty-nine surgical specimens of IDCs of the pancreas were stained immunohistochemically to detect pBcl-2 and pBax expressions whose correlation to tumor classification, staging, and prognosis was analyzed by univariate and multivariate analyses.

RESULTS: The expression of pBcl-2 and pBax was detected in 21 of 59 (35.6%) and in 29 of 59 (49.2%) patients with IDCs of the pancreas, respectively. Neither pBcl-2 nor pBax alone was correlated to TNM staging and differentiation degree of IDCs of the pancreas according to univariate analysis. By Mantel-Cox test, the median survival time after surgery for pBcl-2(+) and pBcl-2(-) groups were 14.3 and 7.3 mo, respectively (χ² = 9.357, P = 0.002) and that for pBax(+) and pBax(-) groups were 12.9 and 10.2 mo, respectively (χ² = 0.285, P>0.05). Contingency coefficient between pBcl-2 and pBax expression was 0.298, indicating that there was correlation between them (χ² = 5.74, P<0.05). The median survival time after surgery for pBcl-2(+)pBax(+) and pBcl-2(+)pBax(-) groups were 14.3 and 14.1 mo, respectively, and that for pBcl-2(-)pBax(+) and pBcl-2(-)pBax(-) groups were 5.9 and 9.9 mo, respectively. There was a significant difference between pBcl-2(+)pBax(+) and pBcl-2(-)pBax(+) (χ² = 5.06, P<0.05), such was the case for pBcl-2(+)pBax(+) and pBcl-2(-)pBax(-) (χ² = 7.18, P<0.01). Cox proportional hazards model for multivariate analysis was applied, indicating that pBcl-2, TNM staging, age and pBax were high risk factors of post-surgical survival time.

CONCLUSION: Both pBcl-2 and pBax have high expression in IDCs of the pancreas, indicating that co-expression of pBcl-2 and pBax is a good indicator of favorable prognosis in IDCs of the pancreas.

Clinicopathological significance of p53 and mdm2 protein expression in human pancreatic cancer

AIM: To study the clinicopathological significance of p53 and mdm2 protein expression in human pancreatic cancer.

METHODS: To investigate the expression of p53 and mdm2 in pancreatic cancer by immunohistochemistry, and the relationships between the p53 and mdm2 protein expression and clinicopathological parameters in pancreatic cancer.

RESULTS: The positive expression of p53 protein was found in 40 of 59 patients (67.8%) and that of mdm2 protein in 17 of 59 patients (28.8%). No obvious relationships were found between p53 as well as mdm2 expression and sex, tumor site, TNM staging and histological differentiation. p53 expression was increased in patients younger than 65 years old, while mdm2 had no relationship with age. The survival time of the patients with the positive expression of p53 and mdm2 proteins was obviously shorter than the other groups.

CONCLUSION: Both p53 and mdm2 presented relatively high expression in human pancreatic cancer. The overexpression of p53 and mdm2 might reflect the malignant proliferation of pancreatic cancer and their co-expression might be helpful to evaluate the prognosis of the patients with pancreatic cancer.

Isolated varices over hepatic flexure colon indicating superior mesenteric venous thrombosis caused by uncinate pancreatic head cancer - a case report

Very rare cases of varices involving right side colon were reported. Most of them were due to cirrhotic portal hypertension or other primary causes. No report case contributed to pancreatic cancer. Here, we reported a case of uncinate pancreatic cancer with the initial finding of isolated hepatic flexure colon varices. Following studies confirmed isolated varices involving hepatic flexure colon due to pancreatic cancer with occlusion of superior mesenteric vein. From this report, superior mesenteric vein occlusion caused by uncinate pancreatic head cancer should be considered as a differential diagnosis of colon varices.

A Thai family with hereditary pancreatitis and increased cancer risk due to a mutation in PRSS1 gene

AIM: To investigate mutation of serine protease 1–cationic trypsinogen (CT, PRSS1) gene in members of a Thai family with hereditary pancreatitis and pancreatic cancer.

METHODS: Polymerase chain reaction and direct sequencing were performed to analyze the PRSS1 gene in two members of the family affected by pancreatitis. Allele specific amplification (ASA) method was then developed to detect the mutation of the PRSS1 gene in all available members of the family and normal control subjects.

RESULTS: A cytosine (C) to thymine (T) mutation at position 2441 (g.2441C>T) of the PRSS1 gene, which results in a substitution of arginine by cysteine at position 116 (R116C) of CT, was identified by direct sequencing in both clinically affected members of the family but was not found in the unaffected member. This mutation, which might be arising from deamination of methylated cytosine in CpG dinucleotide of codon 116 (CGT>TGT), was also detected by the ASA method in the two affected members and a proband’s brother but was not observed in unaffected members and 54 normal control subjects.

CONCLUSION: Autosomal dominant pancreatitis with increased cancer risk in the studied Thai family is most likely due to missense (R116C) mutation in the PRSS1 gene.

Antidiabetic thiazolidinediones induce ductal differentiation but not apoptosis in pancreatic cancer cells

AIM: Thiazolidinediones (TZD) are a new class of oral antidiabetic drugs that have been shown to inhibit growth of same epithelial cancer cells. Although TZD were found to be ligands for peroxisome proliferator-activated receptor γ (PPARγ), the mechanism by which TZD exert their anticancer effect is presently unclear. In this study, we analyzed the mechanism by which TZD inhibit growth of human pancreatic carcinoma cell lines in order to evaluate the potential therapeutic use of these drugs in pancreatic adenocarcinoma.

METHODS: The effects of TZD in pancreatic cancer cells were assessed in anchorage-independent growth assay. Expression of PPARγ was measured by reverse-transcription polymerase chain reaction and confirmed by Western blot analysis. PPARγ activity was evaluated by transient reporter gene assay. Flow cytometry and DNA fragmentation assay were used to determine the effect of TZD on cell cycle progression and apoptosis respectively. The effect of TZD on ductal differentiation markers was performed by Western blot.

RESULTS: Exposure to TZD inhibited colony formation in a PPARγ-dependent manner. Growth inhibition was linked to G1 phase cell cycle arrest through induction of the ductal differentiation program without any increase of the apoptotic rate.

CONCLUSION: TZD treatment in pancreatic cancer cells has potent inhibitory effects on growth by a PPAR-dependent induction of pacreatic ductal differentiation.

Detection of CK20mRNA in peripheral blood of pancreatic cancer and its clinical significance

AIM: To detect the expression of CK20mRNA in peripheral blood of pancreatic cancer and evaluate its clinical significance.

METHODS: Expression of CK20mRNA in peripheral blood was detected by fluorogenic qualitative reverse transcription-polymerase chain reaction (RT-PCR) in 40 cases of pancreatic cancer at the night before operation, in 5 cases of benign pancreatic diseases, in 5 cases of healthy individuals. The relationships were investigated between CK20mRNA expression and the clinicopathological variables, and clinical follow-up outcome in those patients with pancreatic cancer having undergone radical resection.

RESULTS: Of the 40 patients with pancreatic cancer, 23 (57.5%) cases were positive for CK20mRNA expression. CK20mRNA expression was significantly correlated with lymphatic metastasis (P = 0.008), histopathological grading (P = 0.009), and pathological stage (P = 0.021); there was no significant correlation between CK20mRNA expression and age, gender, tumor diameter, and depth of invasion. The cumulative metastasis rates of patients with CK20mRNA expression were higher than those of patients with no CK20mRNA expression within 6 mo (34.7% vs 5.9%, P = 0.043) or 12 mo (73.9% vs 35.3%, P = 0.02) after operation. CK20mRNA expression in peripheral blood of pancreatic cancer indicated poorer prognosis. The survival rate of patients with CK20mRNA expression was lower than that of patients with negative CK20mRNA expression (Log-Rank = 13.31, P = 0.0003).

CONCLUSION: CK20mRNA is a sensitive and specific molecular marker for the detection of micrometastasis in peripheral blood of patients with pancreatic cancer. The CK20mRNA expression in peripheral blood is correlated with biological characteristic of pancreatic cancer. It can help to predict the prognosis of pancreatic cancer after operation, and to determine which patient will benefit from aggressive adjuvant therapies.

Presence of CCK-A, B receptors and effect of gastrin and cholecystokinin on growth of pancreatobiliary cancer cell lines

AIM: To investigate the effects of gastrin and cholecystokinin (CCK) and their specific antagonists on the growth of pancreatic and biliary tract cancer cell lines.

METHODS: Five pancreatic and 6 biliary cancer cell lines with 2 control cells were used in this study. Cell proliferation study was done using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) test and direct cell count method. Reverse transcription-polymerase chain reaction (RT-PCR) and slot blot hybridization were performed to examine and quantify the expression of hormonal receptors in these cell lines.

RESULTS: SNU-308 showed a growth stimulating effect by gastrin-17, as did SNU-478 by both gastrin-17 and CCK-8. The trophic effect of these two hormones was completely blocked by specific antagonists (L-365, 260 for gastrin and L-364, 718 for CCK). Other cell lines did not respond to gastrin or CCK. In RT-PCR, the presence of CCK-A receptor and CCK-B/gastrin receptor mRNA was detected in all biliary and pancreatic cancer cell lines. In slot blot hybridization, compared to the cell lines which did not respond to hormones, those that responded to hormones showed high expression of receptor mRNA.

CONCLUSION: Gastrin and CCK exert a trophic action on some of the biliary tract cancers.

Reversal of the phenotype by K-rasval12 silencing mediated by adenovirus-delivered siRNA in human pancreatic cancer cell line Panc-1

AIM: To investigate the in vitro antitumor effect of adenovirus-mediated small interfering RNAs (siRNAs) on pancreatic cancer and the associated mechanism.

METHODS: A 63-nucleotide (nt) oligonucleotide encoding K-ras^val12 and specific siRNA were introduced into pSilencer 3.1-H1, then the H1-RNA promoter and siRNA coding insert were subcloned into pAdTrack to get plasmid pAdTrackH1-K-ras^val12. After homologous recombination in bacteria and transfections of such plasmids into a mammalian packaging cell line 293, siRNA expressing adenovirus AdH1-K-ras^val12 was obtained. Stable suppression of K-ras^val12 was detected by Northern blot and Western blot. Apoptosis in Panc-1 cells was detected by flow cytometry.

RESULTS: We obtained adenovirus AdH1-K-ras^val12 carrying the pSilencer 3.1-H1 cassette, which could mediate gene silencing. Through siRNA targeted K-ras^val12, the oncogenic phenotype of cancer cells was reversed. Flow cytometry showed that apoptotic index of Panc-1 cells was significantly higher in the AdH1-K-ras^val12-treatment group (18.70% at 72 h post-infection, 49.55% at 96 h post-infection) compared to the control groups (3.47%, 3.98% at 72 and 96 h post-infection of AdH1-empty, respectively; 4.21%, 3.78% at 72 and 96 h post-infection of AdH1-p53, respectively) (P<0.05).

CONCLUSION: These results demonstrate that adenoviral vectors can be used to mediate RNA interference (RNAi) to induce persistent loss of functional phenotypes. In gene therapy, the selective down-regulation of only the mutant version of a gene allows for highly specific effects on tumor cells, while leaving the normal cells untouched. In addition, the apoptosis of pancreatic cancer cell line Panc-1 can be induced after AdH1-K-ras^val12 infection. This kind of adenovirus based on RNAi might be a promising vector for cancer therapy.

Clinical epidemiological research on pancreatic cancer:an analysis of 1027 cases

AIM: To study the pathogenic factors and clinical features of Pancreatic cancer (PC).

METHODS: The odds ratio (OR) and its 95% confidential interval (CI) were calculated. t-test was used to evaluate the risks of life and diet habits, ABO blood types, surgical history, reproductive history, medical conditions and familial history as well as laboratory tests in the induction of PC.

RESULTS: Some life and diet habits such as smoking and drinking (P < 0.01), ABO blood types (type A and B in males, P < 0.05), surgical history such as appendectomy, Partial gastrectomy, and cholecystectomy (P < 0.01), reproductive history, medical diseases (diabetes, etc.), familial history, laboratory tests (HB, ALB, AKP, GGT, GLU) were associated with PC.

CONCLUSION: In order to reduce the occurrence of PC, it is helpful to stop smoking and alcohol drinking, to control body weight, to avoid appendectomy, partial gastrectomy and cholecystectomy, to reduce childbearing at proper age for females. Routine examination for pancreas and follow-up should be taken for those patients who have the related factors and clinical features of PC.