Increased cyclin D1 expression in cancer of the ampulla of Vater: relevance to nuclear beta catenin accumulation and k-ras gene mutation

Intermittent hypoxia exacerbates tumor progression in a mouse model of lung cancer

The purpose of this study was to evaluate whether obstructive sleep apnea (OSA)-related chronic intermittent hypoxia (CIH) influences lung cancer progression and to elucidate the associated mechanisms in a mouse model of lung cancer. C57/BL6 mice in a CIH group were exposed to intermittent hypoxia for two weeks after tumor induction and compared with control mice (room air). Hypoxia inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF) and metastasis-related matrix metalloproteinases (MMP) were measured. The expression levels of several hypoxia-related pathway proteins including HIF-1α, Wnt/ß-catenin, the nuclear factor erythroid 2-related factor 2 (Nrf2) and mammalian target of rapamycin-ERK were measured by western blot. The number (P < 0.01) and volume (P < 0.05) of tumors were increased in the CIH group. The activity of MMP-2 was enhanced after CIH treatment. The level of VEGF was increased significantly in the CIH group (p < 0.05). ß-catenin and Nrf2 were translocated to the nucleus and the levels of downstream effectors of Wnt/ß-catenin signaling increased after IH exposure. CIH enhanced proliferative and migratory properties of tumors in a mouse model of lung cancer. ß-catenin and Nrf2 appeared to be crucial mediators of tumor growth.

RHBDF1 regulates APC-mediated stimulation of the epithelial-to-mesenchymal transition and proliferation of colorectal cancer cells in part via the Wnt/β-catenin signalling pathway

The human rhomboid family-1 gene (RHBDF1) is an oncogene in breast and head and neck squamous cancers. Here, we show that RHBDF1 plays a significant role in colorectal cancer (CRC) formation and that the RHBDF1 expression level is higher in CRC than in corresponding normal tissues. Moreover, RHBDF1 promotes cell proliferation, invasion and migration in vitro. Furthermore, through overexpression and silencing of RHBDF1 and the mediator complex, our study demonstrates that RHBDF1 may positively regulate adenomatous polyposis coli (APC) in the Wnt/β-catenin signalling pathway to increase the expression levels of MMP-14 and Twist, which act as important epithelial-to-mesenchymal transition (EMT) stimulating factors. Additionally, RHBDF1 may regulate c-myc and CyclinD1 expression to influence cell proliferation. Finally, RHBDF1 overexpression and silencing influence CRC growth in BALB/c nude mice. In summary, our findings demonstrate that the regulatory effects of RHBDF1 on EMT and on cell proliferation are partially attributable to the Wnt/β-catenin signalling pathway.

Ampullary carcinoma-A genetic perspective

Ampulla of vater carcinoma (AVC) is a rare gastrointestinal tumour that is associated with a high mortality rate and it's often diagnosed at later stages due to lack of clinical symptoms. Early diagnosis of this condition is essential to effectively treat patients for better prognosis. A significant amount of advancement has been made in understanding the molecular nature of cancer in the past decade. A substantial number of mutations and alterations have been detected in various tumors. Despite the occurrence of AVC across the globe, the number of studies conducted on this tumor type remains low; this is largely due to its rare occurrence. Moreover, AVC tissues are complex and contain mutations in oncogenes, tumour suppressors, apoptotic proteins, cell proliferation proteins, cell signaling proteins, transcription factors, chromosomal abnormalities and cellular adhesion proteins. The frequently mutated genes included KRAS, TP53 and SMAD4 and are associated with prognosis. Several molecules of the PI3K, Wnt signaling, TGF-beta pathway and cell cycle have also been altered in AVCs. This review comprises of all the genetic mutations, associated pathways and related prognosis that are involved in AVCs from the year 1989 to 2017. This report can be used as a stepping-stone to establish biomarkers for early diagnosis of AVC and to discover molecular targets for drug therapy.

Knockdown of the long non-coding RNA HOTTIP inhibits colorectal cancer cell proliferation and migration and induces apoptosis by targeting SGK1

More and more long non-coding RNA (lncRNA) might be serve as molecular biomarkers for tumor cell progression. HOTTIP has been recently revealed as oncogenic regulator in several cancers. However, it remains unclear about whether and how HOTTIP regulates Colorectal cancer (CRC). In the present study, we assayed the expression of HOTTIP in CRC tissues and cell lines, and detected CRC cells (HCT-116 and SW620) proliferation, migration, and apoptosis when HOTTIP was knocked down. Furthermore, we discovered the underlying mechanism. The level of HOTTIP was higher in CRC tissues and in CRC cells compared with adjacent normal tissues and normal colon tissue cell. Knockdown of HOTTIP inhibited the cell proliferation migration and induced apoptosis in HCT-116 and SW620 cell lines. In addition, luciferase reporter assay suggested that knockdown of HOTTIP could target decreasing the expression of Serum- and glucocorticoid-inducible kinase 1 (SGK1) gene, and we subsequently verified that up-regulation of the SGK1 gene promoted cell proliferation and migration and inhibited cell apoptosis in HCT-116 and SW620 cell lines. Furthermore, Knockdown of HOTTIP significantly suppressed the expression of GSK3β, β-catenin, c-myc, Vimentin and MMP-7, and increased the expression of E-cadherin, FoxO3a, p27 and Bim proteins in HCT-116 and SW620 cell lines, and up-regulation of the SGK1 emerged the opposite effect with knockdown of HOTTIP. The data described in this study suggest that HOTTIP may be an oncogene and a potential target in CRC.

CACNA2D3 is downregulated in gliomas and functions as a tumor suppressor

CACNA2D3, an auxiliary member of the alpha-2/delta subunit three family of the voltage-dependent calcium channel complex, plays a critical role in tumor suppression. However, its role in glioma carcinogenesis remains largely unknown. Here, we investigated the putative tumor suppressive role of CACNA2D3 in gliomas. Downregulation of CACNA2D3 was frequently detected in glioma tissues and cells compared with their non-tumorigenic counterparts, and correlated with poor survival. To investigate the underlying mechanism of CACNA2D3 in the development and progression of glioma, we performed CACNA2D3 ectopic expression in glioma cells (U87 and U251) and knockdown of CACNA2D3 in LN229 cells and conducted in vitro and in vivo functional assays. Our findings showed that increased intracellular calcium (Ca²⁺ ) mediated by overexpression of CACNA2D3 induced mitochondrial-mediated apoptosis, upregulation of NLK (through the Wnt/Ca²⁺ pathway) and inhibition of the epithelial-to-mesenchymal transition. Ectopic expression of CACNA2D3 inhibited cell proliferation, migration, invasion, and tumor growth in vitro and in vivo, whereas CACNA2D3 depletion inhibited cell viability and invasion. Furthermore, we confirmed that CACNA2D3 increased NLK expression in vitro by immunostaining and found that downregulation of CACNA2D3 in glioma cells and high-grade glioma tissue was accompanied by increased methylation. A reporter assay showed increased luciferase activity in NLK knockdown glioma cells and transcriptional activity of β-cantenin/TCF was remarkably enhanced, which further confirmed that NLK antagonizes Wnt signaling-mediated anchorage-dependent and independent cell proliferation and invasion. This mechanism may contribute to a better understanding of glioma cancer pathogenesis and facilitate the development of new therapeutic strategies for the treatment of this disease. © 2016 Wiley Periodicals, Inc.

Differential Expression of β-Catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in Intestinal and Pancreatobiliary-Type Ampullary Carcinomas

Introduction: The purpose of this study was to associate immunohistochemical expression of β-catenin, EGFR, CK7, CK20, MUC1, MUC2, and CDX2 in ampullary adenocarcinomas with the type of differentiation and prognosis. Methods: Forty-seven patients with ampullary adenocarcinoma who underwent pancreatoduodenectomy with curative intent from 1997 to 2014 were included in this study. Nine patients with perioperative death were included in the association analysis but excluded from survival analysis. All tumors were classified as intestinal or pancreatobiliary type, according to histologic criteria, and immunohistochemically stained against the aforementioned markers. Results: Eighteen carcinomas were classified as intestinal type and 29 carcinomas as pancreatobiliary type. Univariate analysis revealed that CK20 and CDX2 expression correlates with intestinal type, whereas MUC1 positivity indicates pancreatobiliary type. A marginally significant trend was shown for intestinal-type tumors toward larger size and more frequent MUC2 expression. Using multivariate analysis CK20 ( P = .003) and MUC1 ( P = .004) were identified as independent predictors of the intestinal and pancreatobiliary types, respectively. Mean and median survival was 90.3 and 55 months, respectively. Overall 5-year survival rate was 48%. On univariate survival analysis, overall survival was adversely influenced by the number of infiltrated lymph nodes, elevated Ca19-9 serum levels, jaundice, poor differentiation, T4 stage, N1 stage, TNM stage III, and CDX2 immunonegativity. Multivariate analysis identified TNM stage as the only independent prognostic factor in ampullary adenocarcinoma ( P = .048). Conclusions: Immunoreactivity against CK20 and MUC1 in ampullary carcinomas is a useful adjunct to histologic examination in determining histotype. None of the immunohistochemical markers studied had prognostic significance.

Immunophenotyping of ampullary carcinomata allows for stratification of treatment specific subgroups

BACKGROUND

Ampullary carcinomata (AC) can be separated into intestinal (IT) or pancreatobiliary (PB) subtypes. Although morphological, immunohistochemical and molecular differentiation of IT and PB have been well documented; the prognostic significance of histological subtype and whether patients with either subtype benefit from differential chemotherapeutic regimens remains unclear.

METHODS

As part of a larger cohort study, patients who underwent resection for AC or pancreatic ductal adenocarcinoma (PDAC) were retrospectively identified. Clinicopathological covariates and outcome were obtained and MUC1, MUC2, CDX2 and CK20 were assessed with immunohistochemistry.

RESULTS

Of 99 ACs, the resultant immunophenotypes indicated 48% and 22% were IT and PB, respectively. Thirty (30%) cases were quadruple negative (QN). Within the PDAC cohort (N = 257), the most prevalent immunophenotype was QN (53%). Subsequently, all QN ACs were classified as PB immunohistochemically yielding 47.5% and 52.5% classified as IT and PB, respectively. Involved regional lymph nodes and elevated T-stage were significantly associated with PB compared with IT AC (p = 0.0032 and 0.0396, respectively). Progression-free survival revealed inferior survival for PB versus IT AC (p = 0.0156).

CONCLUSIONS

AC can be classified into prognostic groups with unique clinicopathological characteristics using immunohistochemistry. Immunophenotypical similarity of PB and PDAC suggests that treatment regimens similar to those used in PDAC should be explored.

Association of CCND1 overexpression with KRAS and PTEN alterations in specific subtypes of non-small cell lung carcinoma and its influence on patients' outcome

Cyclin D1 is one of the major cellular oncogenes, overexpressed in number of human cancers, including non-small cell lung carcinoma (NSCLC). However, it does not exert tumorigenic activity by itself, but rather cooperates with other altered oncogenes and tumor suppressors. Therefore, in the present study, we have examined mutual role of cyclin D1, KRAS, and PTEN alterations in the pathogenesis of NSCLC and their potential to serve as multiple molecular markers for this disease. CCND1 gene amplification and gene expression were analyzed in relation to mutational status of KRAS gene as well as to PTEN alterations (loss of heterozygosity and promoter hypermethylation) in NSCLC patient samples. Moreover, the effect of these co-alterations on patient survival was examined. Amplified CCND1 gene was exclusively associated with increased gene expression. Statistical analyses also revealed significant association between CCND1 overexpression and KRAS mutations in the whole group and in the groups of patients with adenocarcinoma, grade 1/2, and stage I/II. In addition, CCND1 overexpression was significantly related to PTEN promoter hypermethylation in the whole group and in the group of patients with squamous cell carcinoma and lymph node invasion. These joint alterations also significantly shortened patients' survival and were shown to be an independent factor for adverse prognosis. Overall results point that cyclin D1 expression cooperates with KRAS and PTEN alterations in pathogenesis of NSCLC, and they could serve as potential multiple molecular markers for specific subgroups of NSCLC patients as well as prognostic markers for this type of cancer.

Nestin predicts a favorable prognosis in early ampullary adenocarcinoma and functions as a promoter of metastasis in advanced cancer

Nestin exhibits stemness characteristics and is over-expressed in several types of cancers. Downstream signaling of nestin [cyclin-dependent kinase 5 (CDK5) and Ras-related C3 botulinum toxin substrate 1 (Rac1)] functions in cancer to modulate cellular behaviors. We studied the function of nestin in ampullary adenocarcinoma. Immunohistochemistry (IHC), reverse transcription-polymerase chain reaction, and cDNA microarray of nestin in ampullary adenocarcinoma was compared with normal duodenum. CDK5 and Rac1 were assessed by western blotting. We hypothesized that nestin/CDK5/Rac1 signaling behaves different in early and advanced cancer. We found that the presence of nestin mRNA was increased in the early stages of cancer (T2N0 or T3N0) and advanced cancer with lymph node metastasis (T4N1). A total of 102 patients were enrolled in the IHC staining. Weak nestin expression was correlated with favorable characteristics of cancer, decreased incidence of local recurrence and lower risk of recurrence within 12 months after surgery. Patients with weak nestin expression had the most favorable recurrence-free survival rates. Patients with mild to strong nestin expression exhibited an advanced behavior of cancer and increased possibility of cancer recurrence. The reciprocal expression of nestin and RAC1 were explored using a cDNA microarray analysis in the early stages of ampullary adenocarcinoma. Increased level of CDK5 with simultaneously decreased expression of Rac1 was detected by western blotting of ampullary adenocarcinoma in patients without cancer recurrence. The activation of multiple oncogenic pathways, combined with the stemness characteristics of nestin, formed a complex network in advanced ampullary adenocarcinoma. Our study demonstrated that nestin performs a dual role in ampullary adenocarcinoma. Appropriate amount of nestin enhances CDK5 function to suppress Rac1 and excessive nestin/CDK5 participates in multiple oncogenic pathways to promote cancer invasiveness. Inhibiting nestin in patients who exhibit nestin-overexpressed ampullary adenocarcinoma may be a method of preventing cancer recurrence.

Aberrant expression of p53, p21, cyclin D1, and Bcl2 and their clinicopathological correlation in ampullary adenocarcinoma

Previous studies on the molecular alterations in ampullary adenocarcinoma (AA) are limited, and little is known about their clinical implications. The objective of this study is to examine the expression of p53, p21, cyclin D1, and Bcl2 and their clinical significance in patients with AA. Tissue microarrays were constructed using archival tissue from 92 patients with AA who underwent pancreaticoduodenectomy at our institution. Each tumor was sampled in triplicate with a 1.0-mm punch from representative areas. The expression of p53, p21, cyclin D1, and Bcl2 was evaluated by immunohistochemistry, and the staining results were correlated with clinicopathological features and survival. Among 92 cases studied, overexpression of p53, p21, cyclin D1, and Bcl2 was observed in 58.7%, 39.2%, 71.7%, and 5.4% of tumors, respectively. Patients whose tumor showed high level of cyclin D1 expression had higher risk of disease recurrence (P = .02) and worse recurrence-free and overall survivals after pancreaticoduodenectomy than did those with no or low cyclin D1 expression (P = .027 and P = .02, respectively). In multivariate analysis, cyclin D1 expression was an independent prognostic factor for both recurrence-free and overall survival (P < .05). However, there was no significant correlation between p53, p21, or Bcl2 expression and survival (P > .05). Our study showed that p53, p21, and cyclin D1, but not Bcl2, are frequently overexpressed in AAs. Cyclin D1 overexpression is associated with increased risk of disease recurrence and worse survival in patients with AA after resection.

Ampullary cancer--a separate clinical entity?

AIMS

Ampullary cancer is a relatively uncommon tumour, with a better prognosis than pancreatic cancer. The purpose of this study was to review the recent literature on ampullary adenocarcinoma, focusing on histological types and prognostic factors.

METHODS AND RESULTS

Using PubMed, we carried out a comprehensive search of the literature, which was extended to April 2013 to retrieve all additional publications. Ampullary cancer comprises two main histological subtypes, the pancreatobiliary type and the intestinal type. These subtypes have different pathogenetic and clinical characteristics. Clinical and histological parameters as well as immunohistochemical markers have been identified as significant prognostic factors in ampullary cancer. Moreover, several immunohistochemical markers have been studied, not only as prognostic factors but as a means of differentiating ampullary from other peri-ampullary tumours, and of identifying the exact histological subtype.

CONCLUSIONS

The considerable differences in the frequencies of the two subtypes of ampullary tumours reported in literature reinforce the necessity to define molecular markers to distinguish them. Until then, the significance of the histological subtype as a prognostic factor should be evaluated cautiously. Future research on the pathogenesis of ampullary cancer will possibly suggest that we should stop treating this type of cancer as a separate entity.

Differential expression of E-cadherin, β-catenin, and S100A4 in intestinal type and nonintestinal type ampulla of Vater cancers

Background/Aims

Epithelial-mesenchymal transition (EMT)-related proteins may exhibit differential expression in intestinal type or pancreatobiliary type ampulla of Vater carcinomas (AVCs). We evaluated the expression of E-cadherin, β-catenin, and S100A4 in intestinal and nonintestinal type AVCs and analyzed their relationships with clinicopathological variables and survival.

Methods

A clinicopathological review of 105 patients with AVCs and immunohistochemical staining for E-cadherin, β-catenin, and S100A4 were performed. The association between clinicopathological parameters, histological type, and expression of EMT proteins and their effects on survival were analyzed.

Results

Sixty-five intestinal type, 35 pancreatobiliary type, and five other types of AVCs were identified. The severity of EMT changes differed between the AVC types; membranous loss of E-cadherin and β-catenin was observed in nonintestinal type tumors, whereas aberrant nonmembranous β-catenin expression was observed in intestinal type tumors. EMT-related changes were more pronounced in the invasive tumor margin than in the tumor center, and these EMT-related changes were related to tumor aggressiveness. Among the clinicopathological parameters, a desmoplastic reaction was related to overall survival, and the reaction was more severe in nonintestinal type than in intestinal type AVCs.

Conclusions

Dysregulation of E-cadherin, β-cadherin, and S100A4 expression may play a role in the carcinogenesis and tumor progression of AVCs.

Mechanisms of RAS/β-catenin interactions

Signaling through the WNT/β-catenin and the RAS (rat sarcoma)/MAPK (mitogen-activated protein kinase) pathways plays a key role in the regulation of various physiological cellular processes including proliferation, differentiation, and cell death. Aberrant mutational activation of these signaling pathways is closely linked to the development of cancer in many organs, in humans as well as in laboratory animals. Over the past years, more and more evidence for a close linkage of the two oncogenic signaling cascades has accumulated. Using different experimental approaches, model systems, and experimental conditions, a variety of molecular mechanisms have been identified by which signal transduction through WNT/β-catenin and RAS interact, either in a synergistic or an antagonistic manner. Mechanisms of interaction comprise an upstream crosstalk at the level of pathway-activating ligands and their receptors, interrelations of cytosolic kinases involved in either pathways, as well as interaction in the nucleus related to the joint regulation of target gene transcription. Here, we present a comprehensive review of the current knowledge on the interaction of RAS/MAPK- and WNT/β-catenin-driven signal transduction in mammalian cells.

Differential Expressions of Cyclin D1 Associated with Better Prognosis of Cancers of Ampulla of Vater

BACKGROUND

Periampullary cancers, the incidence of which increases gradually with industrialization, still pose a significant challenge to clinicians and researchers. Specifically, the role of cell-cycle proteins and tumor suppressor genes in these cancers is not yet clear. Recent studies have revealed that genes and proteins related to cell cycle and apoptosis regulation may be involved in pancreatic carcinogenesis.

METHODS

Tissue samples were obtained from patients with periampullary cancers who underwent surgery at the National Taiwan University Hospital without receiving previous chemotherapy or radiation therapy. All periampullary cancer tissue samples were examined by a pathologist, who was unaware of the parameters to be investigated. A total of 68 patients with periampullary cancers (29 ampulla of Vater cancers (AVCs) and 39 pancreatic ductal cancers (PDCs), including various stages and histological subtypes, were enrolled. The relevant demographic and clinicopathological information was obtained from medical records.

RESULTS

Cell-cycle proteins, including p16, Rb, cyclin D1, p53, and E2F1, were analyzed by immunohistochemical staining. Here, significant differences were noted between AVCs and PDCs with regard to the expression of cyclin D1. This corresponded to a poor prognosis in PDCs (P < 0.05); AVCs, on the other hand, showed a relatively high survival rate. There is no obvious statistical difference between the 2 groups with regard to the expression of p16, Rb, p53, and E2F1. The study also revealed that cyclin D1 plays different roles in the carcinogenesis of AVCs and PDCs.

CONCLUSIONS

The expression of cyclin D1 is more often correlated with prognosis in AVCs than in PDCs, and may serve as a biomarker for the disease.

Distinct expression patterns of E-cadherin and beta-catenin in signet ring cell carcinoma components of primary pulmonary adenocarcinoma

CONTEXT

E-Cadherin and beta-catenin complexes have been suggested to have critical roles in cancer development and progression. Primary signet ring cell carcinoma (SRCC) of the lung is a rare variant of pulmonary adenocarcinoma, and E-cadherin and beta-catenin expressions of this tumor have not been documented, to our knowledge.

OBJECTIVE

To characterize the E-cadherin and beta-catenin expressions in SRCC of the lung.

DESIGN

An immunohistochemical evaluation of E-cadherin and beta-catenin expressions in 10 cases of SRCC of the lung, 10 cases of conventional pulmonary adenocarcinoma, 10 cases of gastric SRCC, and 10 cases of colorectal SRCC was performed.

RESULTS

Membranous E-cadherin and beta-catenin expressions were frequently reduced or absent in all types of tumors tested. Aberrant E-cadherin localization and nuclear beta-catenin accumulation were frequently found in gastric (6/10 and 5/10, respectively) and colorectal (7/10 and 9/ 10, respectively) SRCCs, whereas SRCC of the lung rarely showed aberrant E-cadherin localization (1/10) or nuclear beta-catenin accumulation (0/10).

CONCLUSIONS

Signet ring cell carcinoma of the lung rarely showed aberrant E-cadherin localization or beta-catenin nuclear accumulation, which are frequent events in gastric and colorectal SRCCs. These results suggest that the biologic roles of E-cadherin and beta-catenin complexes in SRCC of the lung differ from their roles in gastric or colorectal SRCCs.

Deregulation of the p16-cyclin D1/cyclin-dependent kinase 4–retinoblastoma pathway involved in the rat bladder carcinogenesis induced by terephthalic acid-calculi

Prolonged cell proliferation in response to irritation by calculi may itself evoke malignant transformation of the urothelium. However, the molecular mechanisms underlying this process are still unknown. The aim of the present study was to investigate cell cycle regulatory mechanisms in bladder carcinogenesis induced by bladder calculi. Six-week-old Wistar rats were consecutively fed a diet containing 5% terephthalic acid (TPA), 5% TPA plus 4% sodium bicarbonate (NaHCO(3)), 4% NaHCO(3), or basal diet for 48 weeks. Animals were killed at weeks 12, 24, and 48. Treatment with 5% TPA caused high incidences of bladder calculi, preneoplastic lesions, and neoplastic lesions. Immunohistochemical examination revealed overexpression of cyclin D1, cyclin-dependent kinase 4 (Cdk4), retinoblastoma (Rb), and proliferating cell nuclear antigen (PCNA) in bladder preneoplastic and neoplastic lesions. In contrast, p16 expression was reduced or absent. These results were confirmed by immunoblotting analysis. Quantitation of mRNA by real-time reverse transcription-polymerase chain reaction (RT-PCR) showed a significant increase in cyclin D1 and PCNA mRNA in tumor cells. None of the 16 transitional cell carcinomas (TCCs) had ras mutations as examined by PCR-single strand conformational polymorphism (PCR-SSCP) analysis. These results suggested that deregulation of p16-cyclin D1/Cdk4-Rb pathway, but not oncogenic activation of ras, plays a crucial role in bladder tumorigenesis induced by bladder calculi.

β-catenin up-regulates the expression of cyclinD1, c-myc and MMP-7 in human pancreatic cancer: Relationships with carcinogenesis and metastasis

AIM: To investigate whether abnormal expression of β-catenin in conjunction with overexpression of cyclinD1, c-myc and matrix metalloproteinase-7 (MMP-7) correlated with the carcinogenesis, metastasis and prognosis of pancreatic cancer, and to analyze the relationship of β-catenin expression with cyclinD1, c-myc and MMP-7 expression.

METHODS: Using immunohistochemistry, we examined the expression of β-catenin, cyclinD1, c-myc and MMP-7 in 47 pancreatic adenocarcinoma tissues, 12 pancreatic intraepithelial neoplasia (PanIN) and 10 normal pancreases, respectively. Proliferation cell nuclear antigen was also tested as the index of proliferative activity of pancreatic cancer cells.

RESULTS: In 10 cases of normal pancreatic tissues, epithelial cells showed equally strong membranous expression of β-catenin protein at the cell-cell boundaries, but the expression of cyclinD1, c-myc and MMP-7 was negative. The expression of β-catenin, cyclinD1, c-myc and MMP-7 in PanIN and pancreatic adenocarcinoma tissues had no significant difference [6/12 and 32/47 (68.1%), 6/12 and 35/47 (74.5%), 5/12 and 33/47 (70.2%), 7/12 and 30/47 (63.8%), respectively]. The abnormal expression of β-catenin was significantly correlated to metastasis and one-year survival rate of pancreatic cancer, but had no relation with size, differentiation and cell proliferation. The expression of cyclinD1 was correlated with cell proliferation and extent of differentiation, but not with size, metastasis and one-year survival rate of the pancreatic cancer. The expression of c-myc was not correlated with size, extent of differentiation, metastasis and 1-year survival rate, but closely with cell proliferation of pancreatic cancer. The overexpression of MMP-7 was significantly associated with metastasis and 1-year survival rate of pancreatic cancer, but not with size, extent of differentiation and cell proliferation. There was a highly significant positive association between abnormal expression of β-catenin and overexpression of cyclinD1, c-myc and MMP-7 not only in PanIN (r = 1.000, 0.845, 0.845), but also in pancreatic cancer (r = 0.437, 0.452, 0.435).

CONCLUSION: The abnormal expression of β-catenin plays a key role in the carcinogenesis and progression of human pancreatic carcinoma by up-regulating the expression of cyclinD1, c-myc and MMP-7, resulting in the degradation of extracellular matrix and uncontrolled cell proliferation and differentiation. β-catenin abnormal expression and MMP-7 overexpression may be considered as two useful markers for determining metastasis and prognosis of human pancreatic cancer.

Prognostic value of Bax, Bcl-2, p53, and TUNEL staining in patients with radically resected ampullary carcinoma

BACKGROUND

There is a lack of data in the literature concerning the identification of potential prognostic factors in ampullary adenocarcinoma.

AIMS

To examine the prognostic significance of Bax, Bcl-2, and p53 protein expression and the apoptotic index in a large cohort of uniformly treated patients with radically resected ampullary cancer.

METHODS

All patients with a pathological diagnosis of ampullary cancer and radical resection were evaluated. Expression analysis for p53, Bax, and Bcl-2 was performed by immunohistochemistry. Apoptotic cells were identified by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL).

RESULTS

Thirty nine tumour specimens from patients with radically resected ampullary adenocarcinoma were studied. A positive significant correlation between Bax and p53 expression was found by rank correlation matrix (p < 0.001). A trend towards a positive correlation was found between the apoptotic index and p53 expression (p = 0.059). By univariate analysis, overall survival was influenced by Bax expression, p53 expression, and TUNEL staining (p = 0.001, p = 0.01, and p = 0.03, respectively). Bcl-2 expression did not influence overall survival in these patients (p = 0.55). By multivariate Cox regression analysis, the only immunohistochemical parameter that influenced overall survival was Bax expression (p = 0.020).

CONCLUSIONS

These results provide evidence that apoptosis may be an important prognostic factor in patients with radically resected ampullary cancer. This study is the first to assess the clinical usefulness of Bax expression in radically resected ampullary cancer.