E-cadherin and urokinase-type plasminogen activator tissue status in gastric carcinoma

Integration of Genomic Biology Into Therapeutic Strategies of Gastric Cancer Peritoneal Metastasis

The peritoneum is a common site of metastasis in advanced gastric cancer (GC). Diagnostic laparoscopy is now routinely performed as part of disease staging, leading to an earlier diagnosis of synchronous peritoneal metastasis (PM). The biology of GCPM is unique and aggressive, leading to a dismal prognosis. These tumors tend to be resistant to traditional systemic therapy, and yet, this remains the current standard-of-care recommended by most international clinical guidelines. As this is an area of unmet clinical need, several translational studies and clinical trials have focused on addressing this specific disease state. Advances in genomic sequencing and molecular profiling have revealed several promising therapeutic targets and elucidated novel biology, particularly on the role of the surrounding tumor microenvironment in GCPM. Peritoneal-specific clinical trials are being designed with a combination of locoregional therapeutic strategies with systemic therapy. In this review, we summarize the new knowledge of cancer biology, advances in surgical techniques, and emergence of novel therapies as an integrated strategy emerges to address GCPM as a distinct clinical entity.

E-cadherin Expression in Canine Gastric Carcinomas: Association with Clinicopathological Parameters

E-cadherin (E-cad) is a cell-adhesion molecule known for its tumor-invasion suppressor function. E-cad expression was examined immunohistochemically in a series of canine tissue samples, including normal gastric mucosa (NGM; n = 3), gastric carcinomas (GC; n = 33), adjacent non-neoplastic mucosa (NNM; n = 32), neoplastic emboli (n = 16) and metastatic lesions (n = 9). The relationship between E-cad expression and clinicopathological features were investigated. In NGM, epithelial cells showed strong latero-lateral membranous expression of E-cad, and this pattern was considered normal. The membranous staining was preserved in all specimens of NNM (100%), whereas abnormal E-cad expression was found in 87.9% of the GCs. A marked difference in E-cad expression was observed between normal and malignant tissues (p < 0.0002). Abnormal E-cad expression was significantly more frequent in poorly/undifferentiated carcinomas (96%) and diffuse (95%) and indeterminate carcinomas (100%) than in well-differentiated/intestinal ones (62.5%; p = 0.0115 and p = 0.0392, respectively). There was significant association between abnormal E-cad expression and the depth of invasion (p = 0.0117), and the presence neoplastic emboli (p = 0.0194). No statistically significant differences in E-cad expression were observed concerning tumor location, histological type according to WHO classification, and presence of metastatic lesions. Therefore, deregulation of E-cad expression may play a role in canine gastric carcinogenesis and in tumor progression; moreover, it might be a prognostic tool for canine gastric cancer.

Staging laparoscopy and peritoneal cytology in patients with early stage gastric adenocarcinoma

Background

Staging laparoscopy and peritoneal cytology can detect occult metastatic disease prior to treatment of gastric cancer. The yield of peritoneal staging in patients with early stage disease is lacking. We assess the yield of peritoneal staging in early stage gastric cancer and its impact on survival.

Methods

Data were obtained from a prospective database of patients who underwent staging laparoscopy and peritoneal cytology for gastric cancer at our institution between July 1995 and July 2018. Clinical stage was determined by endoscopic ultrasound, and early stage was defined as cT1-2 and cN0. Rates of positive cytology and carcinomatosis at time of laparoscopy were obtained. Univariate analyses were used to compare groups, and Kaplan-Meier survival analyses were used to assess survival outcomes.

Results

Eight hundred sixty-seven patients underwent staging laparoscopy and peritoneal cytology; 56 were defined as early stage. Age was 61 ± 12 years, 66.4% were male, and 62.3% were white. Of the patients with early stage disease, 17.9% had either gross carcinomatosis (10.7%) and/or positive peritoneal cytology (10.9%). All cases of peritoneal disease were in patients with cT2 disease. There were no differences in age, gender, or race based on peritoneal disease (all p > 0.05). The presence of carcinomatosis or positive cytology significantly affected overall survival (p < 0.001), regardless of clinical T or N stage.

Conclusions

Peritoneal staging identifies metastatic disease in a significant number of patients with early stage disease. Given its poor prognosis and alternate therapy options, independent staging laparoscopy and peritoneal cytology should be considered in patients with early stage gastric adenocarcinoma.

Protein expression profiles and clinicopathologic characteristics associate with gastric cancer survival

BACKGROUND

Prognosis remains one of most crucial determinants of gastric cancer (GC) treatment, but current methods do not predict prognosis accurately. Identification of additional biomarkers is urgently required to identify patients at risk of poor prognoses.

METHODS

Tissue microarrays were used to measure expression of nine GC-associated proteins in GC tissue and normal gastric tissue samples. Hierarchical cluster analysis of microarray data and feature selection for factors associated with survival were performed. Based on these data, prognostic scoring models were established to predict clinical outcomes. Finally, ingenuity pathway analysis (IPA) was used to identify a biological GC network.

RESULTS

Eight proteins were upregulated in GC tissues versus normal gastric tissues. Hierarchical cluster analysis and feature selection showed that overall survival was worse in cyclin dependent kinase (CDK)2, Akt1, X-linked inhibitor of apoptosis protein (XIAP), Notch4, and phosphorylated (p)-protein kinase C (PKC) α/β2 immunopositive patients than in patients that were immunonegative for these proteins. Risk score models based on these five proteins and clinicopathological characteristics were established to determine prognoses of GC patients. These proteins were found to be involved in cancer related-signaling pathways and upstream regulators were identified.

CONCLUSION

This study identified proteins that can be used as clinical biomarkers and established a risk score model based on these proteins and clinicopathological characteristics to assess GC prognosis.

Prognostic significance, diagnosis and treatment in patients with gastric cancer and positive peritoneal washings. A review of the literature

Peritoneal dissemination is a common consequence of a relapse following a radical surgical treatment of gastric cancer. The development of the disease in the peritoneum depends not only on its stage, but also on free cancer cells exfoliated from the tumor mass or from involved lymph nodes, and which are capable of being implanted in the peritoneum. According to the latest TNM (7 edition; 2010) classification, patients with free cancer cells in the peritoneal washings qualify for stage IV of the disease. Patients in whom free cancer cells were found during the operation - have a recurrence of gastric cancer - mainly in the peritoneum, and the majority of them die within two years of the diagnosis. To properly assess the prognosis, it is vital to determine the stage of cancer by additionally assessing the washings for the presence of free cancer cells before taking a therapeutic decision. This also allows identifying those patients who require different medical procedures to obtain the best treatment results possible. Medical literature describes various methods of examining peritoneal washings aimed at detecting free cancer cells. The methods apply different cancer cell detection rates, sensitivity and specificity in prediction of a peritoneal relapse. Oncological Departments performing the evaluation of the washings employ non-standard methods of treatment in this group of patients and the results presented are promising.

E-Cadherin Expression Is Correlated with the Isolated Cell/Diffuse Histotype and with Features of Biological Aggressiveness of Gastric Carcinoma

We studied the pattern of immunohistochemical expression of E-cadherin in a series of 50 gastric carcinomas, aiming to analyze its relationship with histotype and features of biological aggressiveness of the tumors and survival of the patients. Abnormal E-cadherin expression was significantly (p=.0007) higher in diffuse/isolated-cell type carcinomas than in intestinal/glandular carcinomas. In mixed carcinomas abnormal E-cadherin expression in the diffuse/isolated-cell-type component (94.4%) was significantly (p=.007) higher than in intestinal/glandular component (55.6%). Significant relationships were observed between abnormal E-cadherin expression and nodal metastases (p=.004) and pTNM stages (p=.05). Survival of patients with tumors displaying abnormal E-cadherin expression was worse than that of patients with tumors presenting normal expression, though not attaining the threshold of statistical significance (p=.l9). We conclude that abnormal E-cadherin expression is correlated with diffuse/isolated-cell histotype and features of biological aggressiveness of gastric carcinoma.

Absence of RKIP expression is an independent prognostic biomarker for gastric cancer patients

Gastric cancer is a leading cause of cancer-related mortality, and the presence of lymph node metastasis an important prognostic factor. Downregulation of RKIP has been associated with tumor progression and metastasis in several types of neoplasms, being currently categorized as a metastasis suppressor gene. Our aim was to determine the expression levels of RKIP in gastric tissues and to evaluate its impact in the clinical outcome of gastric carcinoma patients. RKIP expression levels were studied by immunohistochemistry in a series of gastric tissues. Overall, we analysed 222 non-neoplastic gastric tissues, 152 primary tumors and 42 lymph node metastasis samples. We observed that RKIP was highly expressed in ~83% of non-neoplastic tissues (including normal tissue and metaplasia), was lost in ~56% of primary tumors and in ~90% of lymph node metastasis samples. Loss of RKIP expression was significantly associated with several markers of poor clinical outcome, including the presence of lymph node metastasis. Furthermore, the absence of RKIP protein constitutes an independent prognostic marker for these patients. In conclusion, RKIP expression is significantly lost during gastric carcinoma progression being almost absent in lymph node metastasis samples. Of note, we showed that the absence of RKIP expression is associated with poor outcome features of gastric cancer patients, this being also an independent prognostic marker.

The expression of E-cadherin and cathepsin-D in normal oral mucosa, oral epithelial dysplasia and oral squamous cell carcinoma: A comparative analysis between immunohistochemistry and routine histopathology

Background:

E-cadherin is known to be an invasion suppressor gene and cathepsin-D, a protease, which is an invasion promoter and plays a central role in solid tumors including oral cancer.

Aims:

To look for the expression pattern in normal buccal mucosa, dysplastic oral epithelium and oral squamous cell carcinoma (SCC) along with their correlation to individual atypical features, thereby providing an objective to the grading system in predicting the fate of affected epithelium.

Materials and Methods:

To elucidate the expression patterns of these markers, we examined immunohistochemically on formalin fixed, paraffin embedded sections 22 dysplastic epithelia, eight SCC and ten normal buccal mucosa.

Results:

In dysplastic epithelium slight loss of expression of E-cadherin was noted as grade of dysplasia increased. Two cases of carcinoma clearance showed only basal and suprabasal staining. The staining varied in SCC with patchy to complete absence of expression. With cathepsin-D fine to moderate granular cytoplasmic staining was noted in most of the dysplastic epithelium. Similar staining was noted in SCC. The atypical features which strongly correlated to loss of expression of E-cadherin and intense cathepsin-D expression are basilar hyperplasia, loss of cohesion, mitosis, loss of polarity and drop shaped rete ridges.

Conclusions:

The result of the study shows that the above atypical features should be given more weightage in addition to traditional grading system, in predicting the fate of affected epithelium. Additional studies with larger sample size and using monoclonal antibody against cathepsin-D may further strengthen our findings.

Prognostic value of Twist and E-cadherin in patients with osteosarcoma

Twist, a basic helix-loop-helix transcription factor, and E-cadherin are both correlated with the metastatic progression of several types of cancer. However, it is currently unknown whether their activations have relevance to the progression of osteosarcoma. The purpose of the present study was to investigate the clinicopathological and prognostic value of Twist and E-cadherin in osteosarcoma. Twist and E-cadherin expressions were determined by immunohistochemistry. Patient survival rates were determined by Kaplan-Meier method and log-rank test. Cox regression was adopted for multivariate analysis of prognostic factors. The positive rates of Twist and E-cadherin in 107 osteosarcoma specimens were 31.8 % (34/107) and 20.6 % (22/107), respectively. Twist expression was significantly correlated with that of E-cadherin (r = -0.209, P = 0.031). The positive expression of Twist and E-cadherin was significantly associated with metastasis in 107 osteosarcoma specimens (both P < 0.05). Patients with positive Twist expression had significantly poorer overall survival (OS; P < 0.05) and disease-free survival (DFS, P < 0.05) when compared with patients with the negative expression of Twist. Patients with positive expression of E-cadherin had significantly poorer OS (P < 0.05) when compared with patients with negative E-cadherin expression, but not a significantly poorer DFS (P = 0.081). On multivariate analysis, Twist expression and age were found to be independent prognostic factors for OS (both P < 0.05) and DFS (both P < 0.05). Our results suggest that Twist was expressed significantly more and E-cadherin significantly less in osteosarcoma with metastasis, and expression of both might be related to the prediction of metastasis potency and poor prognosis for patients with osteosarcoma.

Co-expression of hepatocyte growth factor and c-Met predicts peritoneal dissemination established by autocrine hepatocyte growth factor/c-Met signaling in gastric cancer

Epithelial-mesenchymal transition (EMT) promotes and facilitates migration and invasion of epithelial tumor cells. EMT is induced by factors such as hepatocyte growth factor (HGF). This study aimed to establish whether the HGF/c-Met pathway is associated with gastric cancer metastasis; especially peritoneal dissemination. HGF and c-Met expression and EMT-related molecules were evaluated using real-time PCR and immunohistochemistry. The role of the HGF/c-Met pathway in EMT and anoikis was determined, and kinase inhibitor SU11274 was tested for its ability to block HGF-induced biological effects. In HGF(-) /c-Met(+) gastric cancer cells, recombinant HGF promoted an EMT phenotype that was characterized by morphology, impaired E-cadherin and induction of vimentin. HGF promoted cell growth, invasiveness and migration and inhibition of anoikis. SU11274 blocked HGF-induced EMT and biological effects in vitro. In HGF(+) /c-Met(+) gastric cancer cells, HGF did not affect the biological outcome of EMT and anoikis, but SU11274 exerted the same inhibitory effects as in HGF(-) /c-Met(+) cells. In vivo, HGF(+) /c-Met(+) gastric cancer cells only established peritoneal dissemination and SU11274 inhibited tumor growth. Clinically, HGF expression was significantly correlated with c-Met expression in gastric cancer. Increased HGF and c-Met had a significant association with poor prognosis and predicted peritoneal dissemination. We demonstrated that the HGF/c-Met pathway induces EMT and inhibition of anoikis in gastric cancer cells. Co-expression of HGF and c-Met has the potential to promote peritoneal dissemination in gastric cancer. Blockade of the autocrine HGF/c-Met pathway could be clinically useful for the treatment of peritoneal dissemination in gastric cancer.

Potentially predictive microRNAs of gastric cancer with metastasis to lymph node

AIM: To detect the expression of 60 microRNAs (miRNAs) in gastric cancer tissues and find new predictive biomarkers of gastric cancer with metastasis.

METHODS: The expressions of 60 candidate miRNAs in 30 gastric cancer tissues and paired normal tissues were detected by stem-loop real-time reverse transcription-polymerase chain reaction. After primary screening of miRNAs expression, 5 selected miRNAs were further testified in another 22 paired gastric tissues. Based on the expression level of miRNAs and the status of metastasis to lymph node (LN), receiver-operating-characteristic (ROC) curve were used to evaluate their ability in predicting the status of metastasis to LN.

RESULTS: Thirty-eight miRNAs expressions in gastric cancer tissues were significantly different from those in paired normal tissues (P < 0.01). Among them, 31 miRNAs were found to be up-expressed in cancer tissues and 1 miRNAs were down-expressed ≥ 1.5 fold vs paired normal gastric tissue. Five microRNAs (miR-125a-3p, miR-133b, miR-143, miR-195 and miR-212) were differently expressed between different metastatic groups in 30 gastric cancer biopsies (P < 0.05). Partial correlation analysis showed that hsa-mir-212 and hsa-mir-195 were correlated with the status of metastasis to LN in spite of age, gender, tumor location, tumor size, depth of invasion and cell differentiation. ROC analysis indicated that miR-212 and miR-195 have better sensitivities (84.6% and 69.2%, respectively) and specificities (both 100%) in distinguishing biopsies with metastasis to LN from biopsies without metastasis to LN.

CONCLUSION: miR-212 and miR-195 could be independent biomarkers in predicting the gastric cancer with metastasis to LN.

Increased Slug and decreased E-cadherin expression is related to poor prognosis in patients with gastric cancer

BACKGROUND

The expression of E-cadherin correlates with the progression and metastasis of gastric cancer. Slug, a member of the snail family of transcriptional factors, is a newly identified factor that represses transcription of the E-cadherin gene. The purpose of the present study was to evaluate the clinical significance of E-cadherin and Slug expression in gastric cancer.

METHODS

Immunohistochemistry was used to investigate the expression of E-cadherin and Slug proteins in 164 patients with gastric cancer. The relationships between the expression of these proteins and clinicopathological factors, including prognosis, were analyzed.

RESULTS

Positive expression of E-cadherin and Slug was observed in 43.9 and 29.9% of cases, respectively. Tumors with reduced E-cadherin or positive Slug expression had greater extent of lymph node metastasis, lymphatic invasion, and venous invasion, and were at a worse stage than the tumors with preserved E-cadherin or negative Slug expression. Slug expression was significantly correlated with reduced E-cadherin expression; 37 of the 49 (75.5%) tumors with positive Slug expression had reduced E-cadherin expression (P = 0.0008). Patients with reduced E-cadherin expression or positive Slug expression had poor clinical outcomes. In the group with preserved E-cadherin expression, the 5-year survival rate was better for patients who were negative for Slug expression than for those who were positive for Slug expression (P = 0.0001). However, multivariate analysis indicated that E-cadherin expression and Slug expression were not independent prognostic factors.

CONCLUSIONS

Evaluation of not only the expression of E-cadherin, but also the coexpression of E-cadherin and Slug in patients with preserved E-cadherin expression would be useful for predicting malignant properties of gastric cancer.

Pathophysiology and biology of peritoneal carcinomatosis

Peritoneal carcinomatosis represents a devastating form of cancer progression with a very poor prognosis. Its complex pathogenesis is represented by a dynamic process comprising several steps. To the best of our knowledge pathogenesis can be partly explained by 3 major molecular pathways: (1) dissemination from the primary tumor; (2) primary tumor of peritoneum; and (3) independent origins of the primary tumor and peritoneal implants. These are not mutually exclusive and combinations of different mechanisms could occur inside a single case. There are still several aspects which need explanation by future studies. A comprehensive understanding of molecular events involved in peritoneal carcinomatosis is of paramount importance and should be systematically pursued not only to identify novel strategies for the prevention of the condition, but also to obtain therapeutic advances, through the identification of surrogate markers of prognosis and development of future molecular targeted therapies.

Activation of 5-lipoxygenase is required for nicotine mediated epithelial-mesenchymal transition and tumor cell growth

Nicotine is shown to be one of the carcinogenic agents for gastric cancer. Perturbation of epithelial-mesenchymal transition (EMT) results in loss of intracellular adhesions leading to tumor progression. In this study, we examined the underlying mechanism of the long-term effects of nicotine on tumor progression in human gastric cancer cells. Nicotine activated 5-lipoxygenase (5-LOX) in three gastric cancer cell lines (MKN-45, MKN-28 and AGS). Cells treated with nicotine dose- and time-dependently induced cell proliferation, invasion and suppressed apoptosis. In addition, cell cycle progression analysis revealed that activation of 5-LOX modulated the G1/S phase transition regulatory proteins and caused cell proliferation. MK886 (5-LOX activating protein inhibitor) mediated the induction of apoptosis by elevation of caspase-3 and Bax/Bcl2 ratio. Abrogation of 5-LOX repressed featured molecular markers of EMT (inactivation of E-cadherin and activation of transcriptional repressor Snail). Blockade of 5-LOX signaling resulted in downregulation of cyclin D1, matrix metalloproteinase (MMP-7, -9), urokinase plasminogen activator (uPA) and its receptor (uPAR), and pro-apoptotic proteins. Furthermore, suppression of Snail and induction of E-cadherin is extracellular signal-regulated kinase (Erk)-dependent. Thus, we conclude that the promotion effect of nicotine on cancer cell progression and EMT is mediated by Erk/5-LOX signaling pathway.

Protein expression profiling and molecular classification of gastric cancer by the tissue array method

PURPOSE

Gastric cancer is heterogeneous clinically and histologically, and prognosis prediction by tumor grade or type is difficult. Although previous studies have suggested that frozen tissue-based molecular classifications effectively predict prognosis, prognostic classification on formalin-fixed tissue is needed, especially in early gastric cancer.

EXPERIMENTAL DESIGN

We immunostained 659 consecutive gastric cancers using 56 tumor-associated antibodies and the tissue array method. Hierarchical cluster analyses were done before and after feature selection. To optimize classifier number and prediction accuracy for prognosis, a supervised analysis using a support vector machine algorithm was used.

RESULTS

Of 56 gene products, 27 survival-associated proteins were selected (feature selection), and hierarchical clustering identified two clusters: cluster 1 and cluster 2. Cluster 1 cancers were more likely to have intestinal type, earlier stage, and better prognosis than cluster 2 (P<0.05). In 187 early gastric cancers (pT1), cluster 2 was associated with the presence of metastatic lymph nodes (P=0.026). Kaplan-Meier survival curves stratified by pathologic tumor-lymph node metastasis revealed that cluster 2 was associated with poor prognosis in stage I or II cancer (P<0.05). Support vector machines and genetic algorithms selected nine classifiers from the whole data set, another nine classifiers for stage I and II, and eight classifiers for stage III and IV. The prediction accuracies for patient outcome were 73.1%, 88.1%, and 76%, respectively.

CONCLUSIONS

Protein expression profiling using the tissue array method provided a useful means for the molecular classification of gastric cancer into survival-predictive subgroups. The molecular classification predicted lymph node metastasis and prognosis in early stage gastric cancer.

Preclinical study of a "tailor-made" combination of NK4-expressing gene therapy and gefitinib (ZD1839, Iressa) for disseminated peritoneal scirrhous gastric cancer

We evaluated the effect of a "tailor-made" chemo-gene therapy in scirrhous gastric cancer (SGC)-bearing nude mice. For this tailor-made approach, we first selected gefitinib (epidermal growth factor receptor-tyrosine kinase inhibitor)-sensitive SGC cell lines, and 5/8 cell lines demonstrated various degrees of gefitinib-sensitivity. In the highly gefitinib-sensitive NUGC-4, the biological response to NK4 (HGF antagonist/angiogenesis inhibitor) was examined. Subsequently, the composition of an NK4-expressing ternary complex (cationic lipid/nucleic acid/HMG-1, 2 protein) was optimized for maximum transfection activity in NUGC-4. Finally, mice were peritoneally coinoculated with NUGC-4 and scirrhous-associated gastric fibroblasts, NF22, on day 0. Animal models were orally administrated gefitinib (50 mg/kg/day, on days 7-28), and peritoneally NK4-expressing ternary complex (on days 14, 21 and 28). NK4-expression suppressed the gefitinib-resistance induced by the interaction between fibroblasts and SGC, and eventually, this tailor-made combination synergistically decelerated the disease progression by inhibiting proliferative, angiogenic and antiapoptotic effects in tumor tissues. On day 28, both the hemoglobin concentration (g/dl) (control (n = 8), 11.9; treated (n = 8), 17.3; p = 0.0014) and the numbers of mice in good condition (control, 2; treated, 8; p = 0.0012) were significantly greater, and the abdominal girth (mm) (control, 81.1; treated, 70.3; p = 0.0036) was significantly reduced. The median points of bloody ascite-free survival time (days) (control, 22; treated, 44; p < 0.0001) and time to euthanasia (days) (control, 36.5; treated, 56; p < 0.0001) were also significantly prolonged. This combination is a potentially useful approach to the treatment of peritoneal gefitinib-sensitive SGC dissemination.

Different matrix micro-environments in colon cancer and diverticular disease

BACKGROUND AND AIMS

The extracellular matrix and the interactive signalling between its components are thought to play a pivotal role for tumour development and metastasis formation. An altered matrix composition as potential underlying pathology for the development of colorectal cancer was hypothesized.

METHODS

In a retrospective study of patients with colon cancer, the extracellular matrix in tumour-free bowel specimen was investigated in comparison with non-infected bowel specimen from patients operated on for colonic diverticulosis. The following matrix parameters with known associations to tumour formation, cell proliferation, invasion and metastasis were analysed by immunohistochemistry and quantified by a scoring system: VEGF, TGF-beta, ESDN, CD117, c-erb-2, cyclin D1, p53, p27, COX-2, YB-1, collagen I/III, MMP-13, PAI and uPAR. Expression profiles and correlations were calculated.

RESULTS

The comparison of the two groups revealed a significantly decreased immunostaining for CD117 and TGF-beta in the cancer group (8.5+/-2.6 vs 10.3+/-2,1 and 4.9+/-1.5 vs 8.1+/-3, respectively), whereas PAI scores were significantly higher than in patients with diverticular disease (8.1+/-1.6 vs 6.2+/-0.9). Overall correlation patterns of matrix parameters indicated pronounced differences between tumour-free tissue in cancer patients compared with patients with diverticular disease.

CONCLUSIONS

Our results indicate distinct differences in the colonic tissue architecture between cancer patients and patients with diverticulitis that support the notion of an altered matrix composition predisposing to the development of colon cancer.

Autotaxin stimulates urokinase-type plasminogen activator expression through phosphoinositide 3-kinase-Akt-nuclear [corrected] factor kappa B signaling cascade in human melanoma cells

Autotaxin, a lysophospholipase D producing lysophosphatidic acid, augments invasive and metastatic potential of tumor cells. Current investigations have focused on understanding the molecular mechanisms by which autotaxin regulates the expression of a major mediator of tumor invasion and metastasis, urokinase-type plasminogen activator (uPA) in human A2058 melanoma cells. Autotaxin induced uPA expression in a dose-dependent manner that was inhibited by pharmacological inhibitors for Gi (pertussis toxin), phosphoinositide 3-kinase (PI3K, LY294002), Akt inhibitor (AktI), proteosome activity and IkappaB phosphorylation (pyrrolidine dithiocarbamate), and by a dominant negative mutant (DN) of Akt. Autotaxin phosphorylated Akt and induced the translocation of nuclear [corrected] factor-kappaB (NF-kappaB) to the nucleus that were inhibited by AktI or by overexpressing DN-Akt. Consistently, green fluorescence protein-tagged p65 of NF-kappaB accumulated in the nucleus by autotaxin that was abrogated when the cells were transfected with DN-Akt. Moreover, autotaxin increased the DNA binding ability of NF-kappaB and promoter activity of uPA. Collectively, these data strongly suggest autotaxin induces uPA expression via the Gi-PI3K-Akt-NF-kappaB signaling pathway that might be critical for autotaxin-induced tumor cell invasion and metastasis.

Recent advances in the treatment of peritoneal dissemination of gastrointestinal cancers by nucleoside antimetabolites

Peritoneal dissemination is the most common cause of metastasis from malignancies in the abdominal cavity. There are no standard treatments for peritoneal dissemination and the results are poor. The reasons for this are as follows: (1) no effective chemotherapeutic agents have been identified or developed; (2) surgical cytoreduction has little effect on survival improvement; and (3) the molecular mechanisms of peritoneal dissemination have not been clarified and no therapy against the target molecules has been developed. However, studies on the molecular mechanisms of peritoneal dissemination have elucidated some of the target molecules and the development of new multimodal therapies has also improved survival. Early postoperative intraperitoneal chemotherapy, hyperthermic intraperitoneal perfusion chemotherapy and neoadjuvant intraperitoneal-systemic chemotherapy have been newly developed, and a novel surgical therapy named peritonectomy has been proposed to perform complete cytoreduction of peritoneal dissemination. At present, these approaches appear to be effective therapeutic modalities for peritoneal dissemination. However, TS-1 and capecitabine have shown worthwhile results in recent clinical trials for patients with advanced gastric cancer. We recently found that newly developed antitumor cytosine nucleoside analogs show a survival advantage in peritoneal dissemination models using human cancer cells. These non-fluoropyrimidine nucleosides may potentially help to improve the poor prognosis observed in patients with advanced cancers involving peritoneal dissemination.

Targeting urokinase-type plasminogen activator and its receptor for cancer therapy

Cancer invasion and metastasis are highly complex processes and a serine protease urokinase-type plasminogen activator/urokinase-type plasminogen activator receptor system has been postulated to play a central role in the mediation of cancer progression. Of note, malignant tumor urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor levels have been found to vary considerably, and to be related to patient prognosis. In mouse models, the urokinase-type plasminogen activator/urokinase-type plasminogen activator receptor system has been studied extensively as a target for anticancer therapy using a variety of approaches. In this review, we discuss the advances in the various modalities that have been used to target the urokinase-type plasminogen activator/urokinase-type plasminogen activator receptor system, including protein-based and peptide-based drugs, antisense therapy, and RNA interference technology. In particular, preclinical mouse model studies that used human tumor xenografts are reviewed.

Autocrine production of biologically active hepatocyte growth factor (HGF) by injured human skin

BACKGROUND

Hepatocyte growth factor (HGF) is a potent regenerative factor involved in wound healing. Previous studies have shown that mesenchymal cells produce HGF, stimulating epithelial cells in a paracrine fashion.

OBJECTIVE

To examine whether autocrine HGF production by keratinocytes can occur upon skin injury.

METHODS

A 31-year-old male patient sustained a burn affecting 80% of his total body surface area. Biopsies were taken from intact skin near the injured area, and skin keratinocytes were separated and cultured. Conditioned medium from keratinocytes was analyzed for HGF by ELISA, surface plasmon resonance (SPR), and dot blotting. Binding of HGF from conditioned medium to its receptor, c-Met, was compared with recombinant HGF by SPR. Finally, we examined the motogenic effect on mouse transformed skin epithelial cells (CCL-53.1) of HGF from conditioned medium.

RESULTS

HGF was detected in the cultured keratinocyte medium. Similar to recombinant HGF, HGF from conditioned medium had a high affinity for dextran sulfate and albumin, and the same epitopes were engaged by the interaction of HGF with the c-Met receptor. The conditioned medium from keratinocytes obtained from the burn patient, but not medium from keratinocytes obtained from healthy volunteers, accelerated the motogenesis of CCL-53.1 cells. Unexpectedly, anti-HGF antibodies did not prevent this effect. However, anti-c-Met antibodies completely inhibited the motogenic effect.

CONCLUSION

Upon injury, human skin keratinocytes might produce biologically active HGF in an autocrine fashion. This HGF might have different structural and/or biological properties from HGF produced by mesenchymal cells.

Prognostic significance of dysadherin expression in patients with non–small cell lung cancer

OBJECTIVE

The aim of this study was to evaluate the expression of dysadherin and E-cadherin and to investigate their clinical significance as prognostic factors in non-small cell lung cancer.

METHODS

Non-small cell lung cancer specimens were obtained from 131 patients undergoing clinically indicated operations at the Department of General and Cardiothoracic Surgery, Kanazawa University Hospital, between 1995 and 1997. All patients had undergone curative resection of the primary tumor, including systematic lymph node dissection. The avidin-biotin-peroxidase complex method was used for immunostaining of dysadherin and E-cadherin.

RESULTS

Among the 131 lung cancer specimens, 46 (35.1%) tumors were positively stained with dysadherin. Preserved membranous E-cadherin staining was present in 45.8% (60/131) of cases. In this analysis dysadherin expression was not correlated with E-cadherin expression (P = .1333), but a significant association was observed between dysadherin expression and survival time. The overall survival of patients with dysadherin-positive tumors was significantly worse than that of those with dysadherin-negative tumors (P = .0059). Patients with reduced E-cadherin immunopositivity survived significantly shorter than those with preserved E-cadherin immunopositivity (P = .0406). The overall survival of patients with positive dysadherin and reduced E-cadherin expression was significantly worse than that of patients with negative dysadherin and preserved E-cadherin expression (P = .0002). Multivariate analysis revealed the independent prognostic value of dysadherin positivity, reduced E-cadherin expression, and lymph node metastasis on overall survival.

CONCLUSIONS

Dysadherin expression is an independent prognostic factor of survival in patients with non-small cell lung cancer, and combined immunohistochemical analysis of dysadherin and E-cadherin expression might provide further prognostic information.

Expression of E-Cadherin and uPA and their Association with the Prognosis of Pancreatic Cancer

OBJECTIVE

E-cadherin (ECD) and urokinase plasminogen activator (uPA) have been noted as markers for tumor metastasis and prognosis in several tumors. We thus investigated the relationship between the expression of ECD and uPA and the clinicopathological characteristics in pancreatic cancer.

METHODS

The expression of ECD and uPA was evaluated in pancreatic cancer tissues from 53 patients.

RESULTS

Among 53 tumor tissues, those from 29 (54.7%) patients showed positive ECD expression and those from 22 (41.5%) patients showed positive expression of uPA. There were four subgroups of ECD/uPA expression: ECD-positive/uPA-negative, ECD-negative/uPA-negative, ECD-positive/uPA-positive and ECD-negative/uPA-positive. These patterns were found in 14 (26.4%), 11 (20.8%), nine (17%) and 19 (35.8%) patients, respectively. The tumor tissues with ECD-negative and uPA-positive expression were associated with larger tumor, distant metastasis and an increased clinical stage. There was a difference in the median survival time between the patients with ECD-positive/uPA-negative pancreatic tissues (median: 18.7 months) and the patients with ECD-negative/uPA-positive pancreatic tissues (median: 7.5 months, P < 0.05), and there was a statistically significant difference in survival curves between these two groups.

CONCLUSION

The combined analysis concerning uPA and E-cadherin expression may be a useful predictor of metastasis in pancreatic cancer.

Abnormal expression of E-cadherin in early gastric carcinoma: its relationship with macroscopic growth patterns and catenin alpha and beta

BACKGROUND

Abnormal expression of E-cadherin plays an important role in the differentiation and progression of gastric carcinoma. There are a few identifiable clinical, histopathologic, and molecular changes that are related with the macroscopic growth patterns of gastric carcinoma. The aim of this study is to elucidate the relation between the macroscopic growth patterns of gastric carcinoma and the abnormal expression of E-cadherin, alpha- and beta-catenins.

STUDY

A total of 97 cases of early gastric carcinoma were examined by immunohistochemistry using monoclonal antibodies against E-cadherin, alpha- and beta-catenins. Macroscopically, 52 cases were elevated types and 45 cases were depressed types.

RESULTS

Early gastric carcinomas with depressed growth showed diffuse histologic type, younger patients' age and smaller size more frequently than tumors with elevated growth. Abnormal expression rates of E-cadherin, alpha- and beta-catenins were 35.1, 36.1, and 46.4%, respectively. Abnormal expression of E-cadherin, alpha- and beta-catenins was significantly associated with depressed tumor growth and diffuse histologic type. By multiple logistic regression analysis. E-cadherin, age, Lauren classification, World Health Organization grade and size were identified as risk factors of macroscopic growth pattern of early gastric carcinomas. Positive associations between E-cadherin and beta-catenin and between alpha- and beta-catenins were found by log linear model analysis.

CONCLUSION

We suggest that E-cadherin plays an important role in the macroscopic growth as well as microscopic differentiation of early gastric carcinomas.

Reduced bikunin gene expression as a factor of poor prognosis in ovarian carcinoma

BACKGROUND

In previous studies, the authors showed that various types of cultured tumor cells treated with exogenous bikunin protein or ovarian carcinoma cells transfected with bikunin cDNA have low invasiveness and diminished metastatic potential. This study was carried out to clarify the relation between the expression of individual bikunin mRNA and tumor progression.

METHODS

Forty-one newly diagnosed ovarian carcinomas were investigated using a semiquantitative reverse transcriptase-polymerase chain reaction.

RESULTS

The authors found that 24 patients had tumors that overexpressed bikunin and that gene expression was reduced in the tumors of the remaining 17 individuals. Bikunin mRNA expression was independent of age, surgical stage, tumor size, degree of differentiation, histologic subtype, and serum CA 125 levels. There was a significant correlation between low expression of bikunin mRNA and lymph node status (P=0.035) or peritoneal status (P=0.042). Multivariate analysis indicated that bikunin was an independent prognostic marker (P=0.013; hazard ratio, 2.30; 95 % confidence interval, 1.13-4.19), even after controlling for lymph node metastasis and the degree of peritoneal dissemination. In addition, low expression was a significant predictor for poor prognosis compared with high expression (2-year survival rate; 75.0 % vs. 47.1 %, respectively; P<0.05).

CONCLUSIONS

The data suggest that low bikunin mRNA expression by ovarian carcinoma cells may be associated with poor prognosis. It is conceivable that testing for bikunin mRNA may identify patients with ovarian carcinoma who are at high risk for early disease recurrence and a poor prognosis.

Prognostic significance of dysadherin expression in advanced colorectal carcinoma

A novel glycoprotein, dysadherin, has an anti-cell - cell adhesion function through downregulating E-cadherin. In this study, we investigated the expressions of dysadherin and E-cadherin in 82 patients with stage II and III colorectal carcinomas to determine the correlation between the two molecules and the clinicopathologic features of each tumour. Dysadherin was not expressed in normal colorectal epithelium. Fifty-one per cent of tumours showed dysadherin immunopositivity in over 50% of cancer cells. Thirty-eight per cent of tumours showed reduced E-cadherin immunopositivity. The increased expression of dysadherin was significantly associated with lung metastasis (P=0.003). The increased expression of dysadherin had a significant impact on patient survival (P=0.0099 and 0.0036, log-rank test for overall and recurrence-free survival rate, respectively). Furthermore, tumour with increased expression of dysadherin and reduced expression of E-cadherin showed the worst prognosis (P=0.0043 and 0.0028, log-rank test for overall and recurrence-free survival rate, respectively). These results suggest that increased dysadherin expression is a significant indicator of poor prognosis for patients with advanced colorectal carcinoma.

Urokinase-type plasminogen activator expression correlates with tumor angiogenesis and poor outcome in gastric cancer

Urokinase plasminogen activating system (PA system) and vascular endothelial growth factor (VEGF) were recently suggested to contribute synergistically to tumor progression. To evaluate the roles of the PA system and VEGF in gastric cancer, the effects of the PA system and VEGF on tumor angiogenesis and the survival of patients with gastric cancer were investigated. Cancer tissues from 101 gastric cancer patients were assayed immunohistochemically for expression of urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), PA inhibitor-1 (PAI-1) and VEGF protein. The positive rates of uPA, uPAR, PAI-1, VEGF expression were 22.8%, 32.7%, 36.6% and 26.7%, respectively. Positive staining was observed in tumor cells (uPA, uPAR, VEGF), or in both tumor cells and stromal cells (PAI-1). The expressions of uPA, uPAR, PAI-1 and VEGF were significantly correlated with the clinicopathological factors: uPA, depth of tumor invasion, differentiation, lymphatic and vascular invasion; uPAR, tumor size, depth, lymph node involvement, differentiation, vascular invasion; PAI-1, tumor size, depth, lymph node involvement, differentiation, vascular invasion; VEGF, differentiation, vascular invasion. The microvessel density (MVD) assessed immunohistochemically was significantly higher in the patients with expression of uPA, uPAR or VEGF, and stepwise analysis identified uPA as an independent correlated factor with MVD. Furthermore, multivariate analysis demonstrated that depth of tumor invasion, lymph node involvement and uPA expression were independent prognostic factors. uPA is a key factor in the PA system, being associated with a poor outcome of gastric cancer, and contributing not only to invasive activity, but also to angiogenesis.

Paranuaclear E-cadherin in gastric adenocarcinoma

Decreased E-cadherin expression permits dissociation and widespread dissemination of gastric adenocarcinoma cells. We studied the relationship between paranuclear E-cadherin distribution and the histopathologic characteristics of gastric adenocarcinomas. E-cadherin immunostains of 173 gastric adenocarcinoma sections revealed paranuclear; punctate to vesicular staining in 18% (16/87) of the intestinal-type adenocarcinomas, 30% (17/56) of the diffuse-type adenocarcinomas, and 30% (9/30) of the mired adenocarcinomas. These data suggest that in some gastric adenocarcinomas, there is a defect in transport of E-cadherin to the cell surface, which may prevent intercellular adhesion and encourage dissemination. Of 34 cancers with paranuclear E-cadherin staining, 20 (59%) had paranuclear staining within the nonneoplastic epithelium, but only 22.0% of 100 carcinomas with absent or membranous E-cadherin staining were accompanied by morphologically benign epithelium with paranuclear E-cadherin. In surface epithelium, paranuclear E-cadherin staining colocalized with Griffonia simplicifolia lectin II in the Golgi apparatus. The presence of paranuclear E-cadherin in cancer-associated benign epithelium suggests that the alteration in the E-cadherin molecule responsible for the paranuclear distribution may be an early change in gastric adenocarcinoma progression.

Correlation between vascular endothelial growth factor-C expression and invasion phenotype in cervical carcinomas

The correlation between vascular endothelial growth factor (VEGF)-C gene expression and in vitro invasive activity and matrix metalloproteinase (MMP)-2 or 9 gene expression and proteolytic activity in 11 cervical carcinoma cell lines, was investigated. Immunohistochemical expression of VEGF-C in 52 cervical carcinoma tissues was also correlated with tumor aggressiveness with respect to clinicopathologic features, tumor vascularity, MMP-2 expression and patient outcome. Expression of VEGF-C mRNA differed remarkably among the cell lines and there was a statistical correlation between VEGF-C gene expression and the number of invaded tumor cells (p = 0.0009) and MMP-2 gene expression and activity (p < 0.05). Anti-VEGF-C antibody inhibited the invasive and proteolytic activity of tumor cells in a concentration-dependent manner. VEGF-C or MMP-2 expression in clinical tissue samples was well correlated with depth of myometrial invasion, endometrial invasion, pelvic lymphnode metastasis and tumor vascularity (p < 0.05) and there was a close relation between VEGF-C and MMP-2 expression (p < 0.0001) in cervical carcinomas. Overall survival rates for 14 patients with strong VEGF-C staining tumors were lower than those for 38 patients with weak VEGF-C staining tumors (p = 0.0132) and VEGF-C tissue status emerged as an independent prognostic parameter (p = 0.0232). These results suggest that VEGF-C expression is closely related to invasion phenotype and affects the patient's survival in cervical carcinomas.

Different patterns of beta-catenin expression in gastric carcinomas: relationship with clinicopathological parameters and prognostic outcome

AIMS

The cadherin-catenin complex is known to play a critical role in maintenance of cell adhesion. Additionally beta-catenin (beta-ct) can also take part in signal transduction and nuclear beta-ct expression could be correlated with poor prognosis in several malignancies. Since, in gastric cancer, this role of beta-ct is still uncertain, we investigated the expression pattern of beta-ct as well as the possible prognostic role.

METHODS AND RESULTS

beta-catenin expression was immunohistochemically investigated in a retrospective series of 401 R0-resected gastric carcinomas. Out of these cases, 54 tumours (13.5%) revealed a preserved membranous beta-ct expression similar to that in normal gastric mucosa. In 80 tumours beta-ct expression was moderately reduced and in 117 tumours highly reduced. In 150 tumours (37.4%), no or only a weak membranous beta-ct expression was found. Additionally, in 53 tumours, a strong beta-ct expression could be observed in the cytoplasm with a simultaneous nuclear beta-ct immunoreactivity in 17 of these 53 tumours, while nine tumours only showed nuclear immunoreactivity without cytoplasmic staining. There were no significant correlations between the degree of membranous beta-ct expression or the different staining pattern (membranous vs. cytoplasmic/nuclear) and the grade of tumour differentiation, the histological tumour type according to Lauren, as well as with the prognostic parameters pT, pN category and vascular invasion. No associations could be found with tumour cell proliferation and the expression of E-cadherin, irrespectively of the different beta-ct staining pattern. Univariate analysis revealed no influence on survival, either for membranous or for cytoplasmic/nuclear beta-ct expression.

CONCLUSION

Our data on 401 tumours suggest that activation of the Wnt/beta-catenin signalling does also occur in a subset of gastric carcinomas. However, in gastric cancer, neither the presence of cytoplasmic/nuclear beta-ct expression nor the reduction or loss of membranous beta-ct expression is correlated with a specific histological tumour type, tumour progression or prognosis.

Membrane-type 1 matrix metalloproteinase enhances lymph node metastasis of gastric cancer

The mechanisms of the lymph node metastasis remain unclear. We demonstrate the role of MT1-MMP on the lymph node metastasis using in vivo experimental model of lymph node metastasis by orthotopic implantation of MT1-MMP transfected gastric cancer cell line in the stomach of nude rats. TMK-1 cell line without expression of MT1-MMP was transfected with the pcDNA3 plasmid containing a 3.4-kb MT1-MMP cDNA fragment by calcium phosphate method, and the transfected cell line was designated as TMK-MT. Western blot and RT-PCR analyses showed the specific bands corresponding to MT1-MMP in the TMK-MT cells. By gelatin zymography, the activated form (62-kDa) of MMP-2 was identified in the medium of TMK-MT cell line, but was not detected in TMK-1 cells. Six weeks after orthotopic implantation of TMK-1 and TMK-MT xenografts of nude mouse-subcutaneus tumor into the stomach of nude rats, gastric tumors were found in all the animals. Histologically, the lymphatic invasion was found in the submucosa of the TMK-MT gastric tumors. Lymph node metastasis was not detected in nude rats bearing TMK-1 gastric tumor (0/8). In contrast, lymph node metastasis was detected in five out of 8 rats, bearing TMK-MT gastric tumor. MT1-MMP immunoreactivity was found on the cell membrane and cytoplasm of TMK-MT cells not only in the lymph node metastasis but also in the stomach tumor. These results suggest that MT1-MMP overexpression induced by transfection of its gene may promote lymph node metastasis of transformed cells.

Localization of IQGAP1 is inversely correlated with intercellular adhesion mediated by e-cadherin in gastric cancers

Down-regulation of E-cadherin function is characteristic of cancer cells and might involve the small G-protein Rho family, including Rac1 and Cdc42. IQGAP1 has been reported to be one of the target proteins of Rac1 and Cdc42. To elucidate the role of IQGAP1 in cancer-cell adhesion, its expression was investigated in 47 cases of human gastric cancer by immunohistochemistry and Western blot upon protein fractionation, especially in comparison with E-cadherin and catenin expression. In the non-cancerous columnar epithelium of the stomach, IQGAP1, as well as E-cadherin/catenin, was expressed at the cell-cell boundary. IQGAP1 was frequently observed diffusely in the cytoplasm in intestinal-type tumors (20/22 cases) but was expressed at the cell membrane in diffuse-type tumors (19/25 cases), thus showing significant association with tumor differentiation (p < 0.01). Interestingly, membranous expression of IQGAP1 was inversely correlated with that of E-cadherin (p < 0.05) or alpha-catenin (p < 0.001). These observations were consistent with the Western blot results following protein fractionation. IQGAP1 was dominantly expressed in the soluble fraction in differentiated tumors; however, in undifferentiated tumors, it was mostly in the insoluble fraction. In contrast, both E-cadherin and alpha-catenin were detected only in the insoluble fraction. Thus, subcellular localization of IQGAP1 from the cytoplasm to the cell membrane was correlated with E-cadherin dysfunction and tumor dedifferentiation in gastric carcinogenesis.

E-cadherin-catenin cell-cell adhesion complex and human cancer

BACKGROUND

The E-cadherin-catenin complex plays a crucial role in epithelial cell-cell adhesion and in the maintenance of tissue architecture. Perturbation in the expression or function of this complex results in loss of intercellular adhesion, with possible consequent cell transformation and tumour progression. Recently, much progress has been made in understanding the interaction between the different components of this protein complex and how this cell-cell adhesion complex is modulated in cancer cells.

METHODS

This is an update of the role of the E-cadherin-catenin complex in human cancers. It emphasizes new features and the possible role of the complex in clinical practice, discussed in the light of 165 references obtained from the Medline database from 1995 to 1999.

RESULTS

More evidence is now appearing to suggest that disturbance in protein-protein interaction in the E-cadherin-catenin adhesion complex is one of the main events in the early and late steps of cancer development. An inverse correlation is found between expression of the E-cadherin-catenin complex and the invasive behaviour of tumour cells. Therefore, E-cadherin-catenin may become a significant prognostic marker for tumour behaviour. Besides its role in establishing tight cell-cell adhesion, beta- catenin plays a major role in cell signalling and promotion of neoplastic growth. This suggests its dual role as a tumour suppressor and as an oncogene in human cancers.

CONCLUSION

Recent developments show that the E-cadherin-catenin complex is more than a 'sticky molecular complex'. Further studies may yield greater insight into the early molecular interactions critical to the initiation and progression of tumours. This should aid the development of novel strategies for both prevention and treatment of cancer.

Loss of E-cadherin expression in early gastric cancer

AIMS

Reduction or loss of E-cadherin expression was examined in early gastric carcinomas and precursor lesions with the following aims: (1) to assess overall E-cadherin expression in various stages of gastric carcinogenesis; (2) to correlate E-cadherin expression with the Lauren type, the grade of differentiation and the type of growth pattern of the tumours; and (3) to correlate E-cadherin expression with lymph node metastasis and overall prognosis.

METHODS AND RESULTS

Forty-five paraffin-embedded gastrectomy specimens from early carcinomas were examined for the presence of various precursor lesions. The Lauren type, the grade of differentiation and the type of growth pattern were reassessed for all early carcinomas. E-cadherin expression was examined using antibody HECD-1. Whereas E-cadherin was strongly and evenly expressed in the gastric foveolar epithelium, intestinal metaplasia and early gastric carcinomas showed a lower expression. A significant difference in E-cadherin expression was found between the Lauren types (P < 0.0001). Moreover, an inverse correlation was found between E-cadherin expression and histological grade (P < 0.0001). Neither a difference in E-cadherin expression between the various growth types nor an association with lymph node metastasis and overall prognosis was found.

CONCLUSIONS

The Lauren types differ in E-cadherin expression, although reduced E-cadherin expression in all probability rather reflects poor differentiation than a diffuse growth pattern 'genotype'. Moreover, E-cadherin expression does not underlie the difference in biological behaviour of early carcinomas with different types of growth pattern. Finally, E-cadherin expression is not associated with lymph node status and 5-year survival rate, at least not in early gastric carcinomas.

Diagnostic and prognostic values of plasma levels of fibrinolytic markers in gastric cancer

In the present study, we determined the plasma and tissue concentrations of tissue-type plasminogen activator, urokinase-type plasminogen activator, plasminogen activator inhibitor-1, plasminogen activator inhibitor-2 and urokinase-type plasminogen activator receptor in 32 patients with pathology-proved gastric cancer. The plasma levels of the same markers were compared in 37 patients with benign gastric ulcer in order to find out if these plasma levels could be used to evaluate the prognostic value in patients with gastric cancer. Plasma plasminogen activator inhibitor-1 was significantly higher in gastric cancer than in benign gastric disease (p < 0.0005), whereas plasma urokinase-type plasminogen activator was significantly lower in patients with gastric cancer than in those with benign ulcer (p = 0.003). There was no significant correlation between tissue and plasma concentrations of the same parameters. The plasma and tissue levels of fibrinolytic parameters were not affected by tumor size or distant metastasis, whereas tumor tissue concentration of urokinase-type plasminogen activator receptor and plasminogen activator inhibitor-2 were significantly higher in N0 than in N1 and N2, and tissue plasminogen activator inhibitor-1 was significantly higher in N0 than in N1. Plasma levels of the five fibrinolytic parameters could not take the place of the corresponding tissue concentrations on the diagnosis and prediction of prognosis in patients with gastric cancer. Tissue concentrations of urokinase-type plasminogen activator receptor and plasminogen activator inhibitor-2, especially the latter, can be used to predict lymph node involvement in patients with gastric cancer.

Urokinase-type plasminogen activator, its inhibitor, and its receptor in patients with upper urinary tract carcinoma

BACKGROUND

Urokinase-type plasminogen activator (uPA) is a serine protease involved in tumor invasion and metastasis. Its activity during metastasis may be regulated by a plasminogen activator inhibitor (PAI). Furthermore, uPA exerts its action by binding to a membrane-bound receptor (uPAR). The authors attempted to examine the immunohistochemical expression of uPA, uPAR, and PAI-1 in patients with transitional cell carcinoma of the upper urinary tract (TCC-UUT).

METHODS

Formalin fixed, paraffin embedded tumor tissues from 154 patients were analyzed using immunohistochemical staining.

RESULTS

There was moderate to strong cytoplasmic staining for uPA, PAI-1, and uPAR in 57.8%, 96.1%, and 88.3%, respectively, of tumor epithelial cells, and in 22.7%, 53.9%, and 24.7%, respectively, of stromal cells at the tumor/stroma interface. Examination of the relationship between immunoreactive score and clinicopathologic findings revealed that the uPA score for stromal cells significantly correlated with the stage and pattern of growth of the tumors. The PAI-1 score for tumor epithelial cells and the uPAR score for stromal cells both correlated with stage, grade, and pattern of growth. The PAI-1-score for stromal cells correlated with stage and grade. The uPAR-score for tumor epithelial cells correlated with stage. When only the immunoreactive scores that were classified as "high" (if the score was > or = 5 or > or = 1, for tumor epithelial and stromal cells, respectively) were considered, univariate analysis revealed that a "high" PAI-1 score for tumor epithelial cells and a "high" uPAR score for stromal cells both were significantly associated with poor disease free and overall survivals, particularly early period survival. In the final models of the multivariate analysis, only stage (all periods, disease free survival and overall survival), and grade (12 months, overall survival) were found to be progressive or prognostic factors.

CONCLUSIONS

Detection of immunoreactivity for plasminogen activator parameters appears to be of little or no value in determining the prognosis of patients with TCC-UUT, although some parameters were found to be associated with high stage or high grade of the tumors.

Prognostic factors in gastric cancer

BACKGROUND

Despite gastric cancer being common, its prognosis has not been improved significantly in recent years. Now, greater insight has been gained into the biological properties of tumour cells, how they become malignant and what mechanisms they may use to invade and metastasize. This involves tumour-associated protease systems, loss or mutation of adhesion molecules and changes in genetics. The view of gastric cancer is changing: it is not only a solid tumour but also exhibits a minimal residual disease component even in the early stages of disease. Such biological tumour characteristics may provide new prognostic factors and also potential new therapeutic options.

METHODS

This is an update of prognostic factors in gastric cancer, emphasizing new biological features, some of which have been investigated by this group over the past few years. Current results are discussed in the light of 212 references obtained from the Medline database from 1979 to 1997.

RESULTS

There is high probability that some of the factors reviewed, such as c-erbB-2, individual course and phenotyping of disseminated tumour cells will become significant new prognostic variables. This is true also, to a lesser extent, of cathepsin D, matrix metalloproteinase 2 combined with activators or tissue inhibitor of metalloproteinases 2, CD44, E-cadherin, p53 and cripto. Plasminogen activator inhibitor 1 (PAI-1), a member of the urokinase-type plasminogen activator (uPA) system, can already be defined as an established new prognostic factor in gastric cancer.

CONCLUSION

PAI-1 should be considered prognostically in addition to established tumour classifications. Moreover, the uPA system is a target for future therapeutic concepts. Further analysis of factors describing tumour biology should lead to new, functionally orientated, tumour classifications in gastric cancer.

Immunohistochemical localization of a urokinase-type plasminogen activator system in squamous cell carcinoma of the oral cavity: association with mode of invasion and lymph node metastasis

The binding of urokinase-type plasminogen activator (uPA) to its receptor (uPAR) has been implicated in cancer invasion and metastasis. This activity is known to be regulated by several inhibitors such as plasminogen activator inhibitors (PAIs). To elucidate the participation of the uPA system in the malignant behaviour of squamous cell carcinoma (SCC) in the oral cavity, uPA, uPAR, PAI-1 and -2 expression and localisation in 34 primary oral cancers were examined immunohistochemically. The results were then compared with clinicopathological findings. The positive rates of uPA, uPAR, PAI-1 and -2 expression were 23.5, 29.4, 29.4 and 11.8%, respectively. uPA expression correlated with mode of cancer invasion according to Yamamoto-Kohama's criteria (p < 0.01) and with secondary regional lymph node metastasis. uPAR expression also correlated with mode of invasion. In particular, the tumours of both uPA- and uPAR-positive [uPA(+)/uPAR(+)] cases were highly invasive. In the present study, neither PAI-1 nor PAI-2 expression correlated with clinicopathological parameters. However, PAI-2 negative cases of uPA(+)/uPAR(+) were significantly more invasive (p < 0.0001). Such uPA(+)/uPAR(+)/PAI-2(-) cases almost always showed secondary lymph node metastasis (p < 0.01). These results indicate that the uPA system plays a significant role in the invasive and metastatic processes of oral SCC, and that this system may be a powerful aid in evaluating the clinical course or prognosis of patients with oral cancer.

A new prognostic strategy for gastric carcinoma: mRNA expression of tumor growth-related factors in endoscopic biopsy specimens

OBJECTIVE

The study analyzed the prognostic value of the transcription of several tumor growth-related genes in gastric carcinoma biopsy specimens.

SUMMARY BACKGROUND DATA

The nodal status is one of the most significant prognostic factors in gastric carcinoma. There are, however, no satisfactory parameters for the preoperative assessment of nodal status.

METHODS

A reverse transcriptase-polymerase chain reaction analysis was used to analyze the transcription of several tumor growth-related genes in endoscopic biopsy specimens from 78 gastric carcinomas. The factors examined were cyclin D1, cyclin E, urokinase-type plasminogen activator, 72-kd type IV collagenase, vascular endothelial growth factor, platelet-derived growth factor-A (PDGF-A), transforming growth factor-beta, and interleukin-10. The relation between the mRNA expression and the clinical pathologic parameters was analyzed statistically.

RESULTS

The incidence of PDGF-A (p = 0.010) and transforming growth factor-beta (p = 0.009) mRNA expression increased as the pathologic stage advanced. Nodal metastasis correlated with cyclin D1 (p = 0.045), cyclin E (p = 0.037), urokinase-type plasminogen activator (p = 0.047), and PDGF-A (p = 0.003) mRNA. Interestingly, the expression of PDGF-A mRNA showed a positive correlation (p = 0.004) with the early presence of lymph node metastases.

CONCLUSIONS

Tumor growth-related factor mRNA in biopsy specimens may be a new prognostic tool.

Differential expression of N-cadherin in pleural mesotheliomas and E-cadherin in lung adenocarcinomas in formalin-fixed, paraffin-embedded tissues

The differential diagnosis of pleural mesotheliomas and lung adenocarcinomas presents a continued challenge in the practice of surgical pathology. Paraffin immunohistochemistry (IHC) using different panels of antibodies can be helpful in some cases, but, as yet, no antigen is expressed specifically in mesotheliomas nor in adenocarcinomas. Using well characterized monoclonal antibodies (MAb) that recognized distinct mesenchymal and epithelial adhesion proteins, N-cadherin (13A9 MAb) and E-cadherin (E9 MAb), respectively, we found previously that in frozen-section IHC mesotheliomas and adenocarcinomas had distinct cadherin phenotypes: mesotheliomas were positive for N-cadherin, and lung adenocarcinomas were positive for E-cadherin. Using antigen-retrieval methods, we successfully extended our study to formalin-fixed, paraffin-embedded tissue sections. Tumors from 28 patients (14 originally diagnosed as mesotheliomas, and 14 diagnosed as adenocarcinomas) were stained with 13A9 MAb and E9 MAb. Review of hematoxylin-eosin sections excluded from analysis one case previously diagnosed as mesothelioma, which represented a hemangiopericytoma. Of the remaining 27 cases, 12 of 13 mesotheliomas were positive for N-cadherin and negative for E-cadherin. The exception was a multifocal microscopic papillary tumor of apparent mesothelial origin, which was negative for both N-cadherin and E-cadherin. Conversely, 13 of 14 adenocarcinomas were E-cadherin positive and N-cadherin negative except for one adenocarcinoma with focal N-cadherin expression. One case of a poorly differentiated adenocarcinoma invading skeletal muscle was negative for both 13A9 and E9. These studies confirmed the utility of the cadherin antibodies in distinguishing pleural mesotheliomas from lung adenocarcinomas. The reactivity of the cadherin-specific antibodies with antigens in paraffin sections make them powerful and reliable markers in the practice of diagnostic surgical pathology.

Prognostic value of E-cadherin expression in 413 gastric carcinomas

E-cadherin is a Ca(2+)-dependent intercellular adhesion molecule known to exert an invasion-suppressor function. In the present study, E-cadherin expression was immunohistochemically investigated in a retrospective series of 413 RO-resected gastric carcinomas using the monoclonal antibody (MAb) 5H9. Of these cases, 108 tumors revealed a preserved E-cadherin expression similar to that of normal gastric mucosa. In 95 tumors, E-cadherin expression was moderately reduced and in 86 tumors highly reduced. In 124 tumors, no or only a very weak dotted expression could be detected. There was a significant correlation between the degree of E-cadherin expression and the grade of tumor differentiation, as well as with histological type according to the Laurén and the WHO classifications. In contrast, no correlation could be demonstrated between E-cadherin expression and the prognostic parameters depth of invasion, lymph node involvement and vascular invasion. As shown by univariate Cox regression analysis, patients with E-cadherin-positive tumors had significantly better 3-and 5-year survival rates than patients with E-cadherin-negative tumors. This prognostic impact remained present in a multivariate Cox regression analysis, including the prognostic parameters pT category, pN category and vascular invasion.