Expression of pancreatic trypsinogen in human extrapancreatic gastrointestinal carcinomas

Pancreatic trypsinogen expression in 149 surgically resected extrapancreatic gastrointestinal neoplasms was evaluated immunohistochemically. Immunohistochemistry was performed using a monoclonal antibody against human pancreatic trypsinogen. Pancreatic trypsinogen expression was detected in 28 of 55 gastric carcinomas (50.9%), 22 of 44 colorectal cancers (50%), 12 of 20 gallbladder cancers (60%), nine of 10 extrahepatic bile duct cancers (90%), and none of 20 hepatocellular carcinomas. The intensity of immunoreactivity in the tumor area varied from specimen to specimen, and from area to area within the same specimen. In most cases, however, immunoreactivity was more pronounced at the infiltrative margin of the tumor. Additionally, the highly differentiated carcinoma cells tended to display a focal, fine granular immunoreactive pattern, usually present in the supranuclear cytoplasm, while the poorly differentiated carcinoma cells displayed a fine granular pattern, usually present over the entire cytoplasm. These findings suggest that some extrapancreatic gastrointestinal neoplasms express pancreatic trypsinogen immunoreactive peptides, raising the possibility that secreted pancreatic trypsinogen plays a role in carcinoma invasion and metastasis, as has been shown for other classes of proteases.     

环氧合酶-2在胰腺癌组织中的表达及其意义

背景与目的:非甾体类抗炎药物(nonsteroidalanti-inflammatorydrugs,NSAIDs)可以预防或降低消化系统肿瘤的发病率,提示环氧合酶-2(cyclooxygenase-2,COX-2)的表达与消化系统肿瘤的发生、发展密切相关。本研究通过检测胰腺癌组织中COX-2的表达,探讨COX-2与bcl-2表达的关系,及其在胰腺癌发生、发展过程中的作用。方法:胰腺癌等组织COX-2和bcl-2的表达采用ABC免疫组化分析;评价两者表达及其与患者临床病理特征的关系。结果:胰腺癌组织COX-2和bcl-2的表达阳性率分别为73.3%和66.7%,阳性率明显高于胰腺良性病变组织和正常胰腺组织,两者呈高度正相关,相关系数r=0.470(P<0.01)。但COX-2表达率与患者临床病理特征无关(P>0.05)。结论:胰腺癌组织中COX-2表达增强,COX-2表达与bcl-2表达有协同效应,两者共同参与胰腺癌细胞凋亡的调控。     

Overexpression of the c-MET/HGF receptor gene in human thyroid carcinomas.

The receptor for Hepatocyte Growth Factor is a transmembrane tyrosine kinase encoded by the c-MET oncogene. We have previously shown that the Met protein is expressed in several human epithelial tissues. The receptor is barely detectable, however, in normal thyroids and in specimens from patients affected by non-neoplastic thyroid diseases. Now we report that the expression of the Met/HGF receptor is increased a hundred fold in 22 out of 41 human carcinomas derived from the thyroid follicular epithelium. A comprehensive analysis of 15 cases showed that the overexpressing carcinomas belong to histotype variants correlated with negative prognosis and in all but one case there were evidences of locally advanced disease and/or distant metastases. The 11 benign adenomas and the 5 medullary carcinomas tested were negative. Western blot analysis with monoclonal antibodies directed against either the intracellular or the extracellular receptor domains failed to reveal major structural alterations. Southern blot analysis also demonstrated that the c-MET gene was not amplified nor rearranged. These data suggest a role for the overexpression of c-MET oncogene in the pathogenesis and progression of thyroid tumors derived from the follicular epithelium.     

Overexpression of HER-2 in ovarian carcinomas

The transmembrane receptor encoded by the HER-2 cellular oncogene is amplified in several types of human carcinomas and provides an attractive therapeutic target. Shown by immunohistology, <25% of newly diagnosed ovarian carcinomas express the HER-2 protein. However, now we report that this protein was expressed in all 20 tumor cell lines derived from stage III and IV ovarian cancers as well as in tumor cells harvested from patients with malignant ascites and in tumor samples taken at a second surgery, suggesting that cells with excess expression may have a selective growth advantage. HER-2-positive ovarian carcinoma cells were shown to be sensitive to antibody-dependent cellular cytotoxicity, and their in vitro proliferation was inhibited by anti-HER-2 MAb Herceptin. We postulate, therefore, that therapy which targets HER-2 may be more efficacious in patients with ovarian carcinoma than indicated by the commonly low expression of HER-2 in tumors removed at the time of primary surgery.     

Overexpression of gastrin and c-met protein involved in human gastric carcinomas and intestinal metaplasia

Many studies have investigated the expression of c-met and c-erbB2 protein in human gastric adenocarcinomas, but the expression of gastrin protein in human gastric cancer and the relationship between gastrin and c-met are unknown. We have constructed a tissue microarray containing 408 formalin-fixed and paraffin-embedded human tissue blocks, including tissues containing intestinal metaplasia (IM, n=72) and primary tumors (n=232), as well as normal gastric mucosa (n=104) from patients with gastric cancer. Immunohistochemistry (IHC) was used for detecting gastrin, c-met and c-erbB2 proteins. Gastrin was detected in 13.5% (7/52) and c-met in 15.3% (11/72) of IM cases. In gastric carcinomas, 48.4% (103/213) of cases expressed gastrin, 68.8% (148/215) expressed c-met, and 5.5% (11/200) expressed c-erbB2. Gastrin and c-met protein expression were significantly higher in gastric tumor tissue than in IM (P<0.0001). Overexpression of c-erbB2 protein was detected in gastric carcinomas but not in normal gastric mucosa (P<0.05). Expression of gastrin and c-met protein was associated (P<0.01), but no significant difference was found on the changes of gastrin, c-met and c-erbB2 expression in gastric cancer with tumor stage, grade of differentiation or tumor type. These results indicate that gastrin and c-met play a role in the early process during malignant transformation of the gastric mucosa.     

Evaluation of new anticancer agents against human pancreatic carcinomas in nude mice

Heterotransplantation of human cancers in nude mice has provided an in vivo model for studying the biologic characteristics of human tumors, particularly their response to chemotherapy. In an effort to identify cytotoxic agents effective against pancreatic carcinoma, this model was used to evaluate the efficacy of three new anticancer agents--menogarol, 4'-epirubicin, and taxol--against two human transplanted pancreatic tumors. Relative area (tumor length X width) differed significantly between menogarol-treated and control groups (p = 0.034). A marked response was also observed in the tumors to 4'-epirubicin (p = 0.01). Taxol was ineffective in controlling tumor growth; by the fourth week, the size of treated tumors was similar to that of the control group (p = 0.55). No toxicity was observed in either the menogarol- or taxol-treated animals. Animals bearing the P2 tumor, and treated with 4' epirubicin displayed severe toxicity by day 18 with death by day 21 in most animals. For the second tumor, Capan-1, relative area differed significantly between the menogarol-treated and the control group (p = 0.003). In animals given 4'-epirubicin, a smaller difference was observed when comparing the relative areas (p = 0.09). Animals treated with taxol again showed no difference in the tumors when compared with controls (p = 1.0). The use of the nude mouse system has evolved so that tumor-oriented trials are now feasible with the hope of clinical applicability. This study illustrates that at least two agents--menogarol and 4'-epirubicin--may have some antitumor activity against pancreatic carcinoma in this system.     

Overexpression and activation of hepatocyte growth factor/scatter factor in human non-small-cell lung carcinomas.

Hepatocyte growth factor/scatter factor (HGF/SF) stimulates the invasive growth of epithelial cells via the c-MET oncogene-encoded receptor. In normal lung, both the receptor and the ligand are detected, and the latter is known to be a mitogenic and a motogenic factor for both cultured bronchial epithelial cells and non-small-cell carcinoma lines. Here, ligand and receptor expression was examined in 42 samples of primary human non-small-cell lung carcinoma of different histotype. Each carcinoma sample was compared with adjacent normal lung tissue. The Met/HGF receptor was found to be 2 to 10-fold increased in 25% of carcinoma samples (P = 0.0113). The ligand, HGF/SF, was found to be 10 to 100-fold overexpressed in carcinoma samples (P < 0.0001). Notably, while HGF/SF was occasionally detectable and found exclusively as a single-chain inactive precursor in normal tissues, it was constantly in the biologically-active heterodimeric form in carcinomas. Immunohistochemical staining showed homogeneous expression of both the receptor and the ligand in carcinoma samples, whereas staining was barely detectable in their normal counterparts. These data show that HGF/SF is overexpressed and consistently activated in non-small-cell lung carcinomas and may contribute to the invasive growth of lung cancer.     

Nonrandom chromosomal rearrangements in pancreatic carcinomas.

Short-term cultures were initiated from 20 carcinomas of the pancreas, 17 of which could be successfully cytogenetically analyzed. In eight carcinomas, only normal karyotypes were detected, probably representing dividing stromal cells. Three cases had -Y as the sole anomaly, which also may have occurred in cells that do not belong to the tumor parenchyma. Massively rearranged karyotypes with modal chromosome numbers in the triploid (five cases) and diploid-triploid (one case) ranges were found in the remaining six carcinomas. Structural rearrangements, including deletions and unbalanced translocations, of the long arm of chromosome 6, involving bands q13 and q15 twice and q11 and q16 once, occurred in four tumors. All of these aberrations led to loss of chromosome material from 6q, always involving 6q15. Deletions and unbalanced translocations of the short arm of chromosome 1 also were found in four cases, affecting band p32 in three of them. In all four cases, the abnormalities resulted in loss of genetic material distal to 1p32. Chromosome 17 was involved in structural aberrations in three cases, twice as unbalanced translocations leading to loss of 17p material. Deletions of the short arms of chromosomes 3 and 8 were detected in two carcinomas. The most consistent numerical abnormalities were +2, +10, +11, +14, and tetrasomy 20, which were seen in all six cases. The findings suggest that structural rearrangements, or loss, of genes located on 1p, 3p, 6q, 8p, and 17p are of pathogenetic importance in pancreatic carcinogenesis.     

Differential expression of pancreatic trypsinogen and cathepsin-B in human scirrhous-type and intestinal-type gastric carcinomas

Pancreatic trypsinogen and cathepsin B expression was evaluated in 44 surgically resected gastric carcinomas by immunohistochemical analysis. Carcinomatous tissues were subjected to immunohistochemical staining with a monoclonal antibody against human pancreatic trypsinogen and a polyclonal antibody against human cathepsin B. As a result, twenty-two of 24 scirrhous-type gastric carcinomas (92%) expressed pancreatic trypsinogen intensely and diffusely in a fine granular pattern over the entire cytoplasm of carcinoma cells. In contrast, only 5 of 20 intestinal-type gastric carcinomas (25%) reacted with the trypsinogen specific antibody and then only focally, in a fine granular pattern in the supra-nuclear cytoplasm of carcinoma cells. Cathepsin B expression was detected in 20 of 24 scirrhous-type gastric carcinomas (84%) in a fine, diffuse, granular pattern in the cytoplasm of carcinoma cells, while only 2 of 20 intestinal-type gastric carcinomas (10%) had detectable cathepsin B. From these results, we find that scirrhous-type gastric carcinomas express abundant quantities of pancreatic trypsinogen and cathepsin B immunoreactive peptides.     

Pancreatic trypsinogen and cathepsin B in human pancreatic carcinomas and associated metastatic lesions.

Expression of pancreatic trypsinogen and cathepsin B in 23 surgically resected pancreatic ductal adenocarcinomas was evaluated immunohistochemically, using a monoclonal antibody against human pancreatic trypsinogen and a polyclonal antibody against human cathepsin B. Fifteen of 20 invasive tubular adenocarcinomas (75%) expressed pancreatic trypsinogen in a coarse granular pattern located in the supranuclear cytoplasm of the carcinoma cells. In addition, metastatic lesions, including those in peripancreatic lymph nodes and neural plexuses, expressed pancreatic trypsinogen. In contrast, three intraductal (non-invasive) papillary adenocarcinomas did not express pancreatic trypsinogen. Cathepsin B expression was recognised in 14 of 20 invasive tubular adenocarcinomas (70%) in a fine granular pattern located diffusely in the cytoplasm of the carcinoma cells, while none of the three intraductal papillary adenocarcinomas had detectable cathepsin B. These findings suggest that pancreatic invasive ductal adenocarcinomas express pancreatic trypsinogen and cathepsin B immunoreactive peptides, raising the possibility that pancreatic trypsinogen and cathepsin B may act independently of each other in the process of carcinoma invasion and metastasis, like other different classes of proteases involved in the proteolytic modification of the matrix barrier.     

Expression of basic fibroblast growth factor and its receptor in human pancreatic carcinomas.

We examined the expression of basic fibroblast growth factor (FGF) and FGF receptor by immunohistochemistry in 32 human pancreatic ductal adenocarcinomas. Mild to marked basic FGF immunoreactivity was noted in 19 (59.4%) of the 32 tumours examined, and 30 (93.3%) of the tumours exhibited a cytoplasmic staining pattern against FGF receptor. The tumours were divided into two groups according to the proportion of positively stained tumour cells: a low expression group (positive cells < 25%) and a high expression group (positive cells > or = 25%). No statistically significant difference in tumour size, differentiation, metastases or stage was found between the low and high basic FGF expression groups. However, a significant correlation was found between FGF receptor expression level and the presence of retroperitoneal invasion, lymph node metastasis, and tumour stage. In addition, low FGF receptor expression was significantly associated with a longer post-operative survival as compared with high FGF receptor expression, whereas there was no significant difference in post-operative survival between the low and high basic FGF expression groups. Increased expression of FGF receptor is correlated with the extent of malignancy and post-operative survival in human pancreatic ductal adenocarcinomas. Thus, overexpression of FGF receptor may prove to be a more useful prognostic marker than basic FGF expression level in pancreatic cancer patients.     

Overexpression of the opioid growth factor receptor potentiates growth inhibition in human pancreatic cancer cells

The opioid growth factor (OGF), [Met5]-enkephalin, and OGF receptor (OGFr) form an inhibitory axis regulating the growth of human pancreatic cancer. This study examined whether overexpression of OGFr decreases the growth of pancreatic cells in vitro. MIA PaCa-2 cells were transfected with OGFr cDNA, and six clonal lines were examined for protein expression and function. OGFr binding assays revealed a 2.3- to 5.6-fold increase in binding capacity from wild-type (WT) and empty vector (EV) controls; binding affinity was comparable in all groups. OGFr protein expression, as measured by immunohistochemistry and Western blotting, was enhanced in clonal cell lines compared to controls. Doubling times of OGFr clonal lines were 47-91% longer than in the WT/EV groups for all but one clonal line. DNA synthesis of cells overexpressing OGFr was diminished from the WT/EV groups by 28-52%. Addition of exogenous OGF further reduced (14-31%) the cell growth of clonal lines, and the effects of exogenous OGF were receptor-mediated. Exposure of cells overexpressing OGFr to naltrexone increased the cell number by up to 9.4-fold. OGF was identified as the only opioid peptide to depress cell replication in the transfected cell lines. Neutralization of endogenous OGF with antibodies to this peptide elevated the cell number in clonal cell lines. These data identify OGFr at the molecular level as integral to regulating the cell replication of human pancreatic cancer, and support treatment modalities that amplify OGFr in order to decrease the growth of these neoplasias.     

Overexpression of oncoproteins in non-small cell lung carcinomas of smokers

Non-small cell lung carcinoma specimens of 173 previously untreatedpatients were analyzed for the expression of proteins encodedby the oncogenes c-myc, c-fos, c-jun, c-erbB-1, c-erbB-2, c-H-ras,c-K-ras and c-N-ras. Forty-six per cent of the tumors were positivefor the c-MYC protein, 60% for c-FOS, 50% for c-JUN, 80% forc-ERBB-1, 55% for c-ERBB-2, 12% for c-H-RAS, 5% for c-K-RASand 71% for c-N-RAS. Proteins encoded by c-fos and c-jun areover-expressed more frequently in carcinomas of smokers (c-fos:P < 0.005; c-jun: P < 0.01). When we grouped the patientsaccording to their tumor histology the results became more evident.Squamous cell lung carcinomas of smokers showed a higher incidenceof c-FOS (P = 0.01), c-JUN (P < 0.01) and c-ERBB-1 (P = 0.01)proteins than squamous cell lung carcinomas of non-smokers.The expression rate and the intensity of staining proved notto be influenced either by the number of cigarettes smoked dailyor by cessation of smoking. In adenocarcinomas, however, weonly found a trend for a more frequent overexpression of c-fos(P = 0.07) and c-jun (P = 0.14) encoded proteins in carcinomasof smokers and no correlation between the expression of c-erbB-1products and smoking. No correlation was found between the expressionof c-MYC, c-ERBB-2, c-H-RAS, c-K-RAS and c-N-RAS proteins andthe smoking habits of the patients, neither in squamous cellcarcinomas nor in adenocarcinomas of the lung.