Involvement of matrix metalloproteinase-7 in invasion-metastasis through induction of cell dissociation in pancreatic cancer

Epidermal growth factor receptor (EGFR) mediated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway was isolated as invasion-metastasis related factor in pancreatic cancer in our previous studies. Matrix metalloproteinase-7 (MMP-7) and tight junction (TJ) proteins are indicated to be involved in cancer invasion-metastasis. To clarify the underlying mechanism of involvement of MMP-7 in cancer invasion, western blotting, invasion assay and immunohistochemistry were performed in dissociated (PC-1.0 and AsPC-1) and non-dissociated (PC-1 and Capan-2) pancreatic cancer cells, as well as pancreatic cancer tissues. Intracellular MMP-7 protein presented as pre-proenzyme and its expression was decreased by AG1478 (EGFR inhibitor) or U0126 (MEK inhibitor) treatment in pancreatic cancer cells. Activated MMP-7 protein was only detected in the medium of PC-1.0 and AsPC-1 cells, but not detected in the medium of PC-1 and Capan-2 cells. Moreover, MMP-7 treatment significant induced the dissociation of cell colonies in PC-1 and Capan-2 cells. Synchronously, TJ structure was apparently disrupted and translocation of TJ proteins to cytoplasm or extracellular medium was induced in PC-1 and Capan-2 cells. Furthermore, MMP-7 treatment markedly increased the in vitro invasion of PC-1 and Capan-2 cells. In addition, MMP-7 expression at the invasive front was obviously stronger than that at the center of pancreatic cancer tissues. Activation of MMP-7 protein is closely involved in disruption of TJ structure and consequent induction of cell dissociation as well as invasion in pancreatic cancer. EGFR mediated MEK/ERK signaling pathway is implied to be involved in regulation of MMP-7 expression in pancreatic cancer cells.

Identification of genes related to invasion and metastasis in pancreatic cancer by cDNA representational difference analysis

The difference in gene expression between the highly invasive and metastatic cell line PC-1.0 and the weakly invasive and metastatic cell line PC-1 both derived from a pancreatic ductal carcinoma induced by N-nitrosobis (2-oxopropyl) amine (BOP) in Syrian golden hamster was examined using the Representational Difference Analysis (RDA) method. Within 8 clones (cDNA fragments) successfully isolated after subtraction hybridization of PC-1 cDNA from PC-1.0, 5 clones were shown to be specific or highly expressed in PC-1.0 as confirmed by RT-PCR. Among these 5 clones, two known genes, MAP kinase kinase 2 (MKK2) and phosphatidylinositol 4-kinase (PI4K230) were detected by gene sequencing. The specific expressions of MKK2 and PI4K230 in the highly invasive and metastatic cell line PC-1.0 were confirmed by RT-PCR and Northern blotting. By adding the CM of PC1.0 which included the cancer cell dissociation factor (DF), PC-1 cells began to dissociate and migrate from the colonies, and in addition the expression of MKK2 was found to be induced. On the other hand, the expression of PI4K230 was not induced in PC-1 cells by adding the CM of PC-1.0. Interestingly, in PC-1.0 the expression of PI4K230 was completely abolished and apoptosis induced by the PI3K inhibitor wortmannin. These results suggest that both MKK2 and PI4K230 are factors of a signal transduction pathway that might play an important role related to invasion and metastasis through the induction of cell motility and/or the inhibition of apoptosis.

Cystatin M / E expression in inflammatory and neoplastic skin disorders

BACKGROUND

Cystatins are natural and specific inhibitors of endogenous mammalian lysosomal cysteine proteinases and exogenous microbial cysteine proteinases. Cystatins were shown to provide regulatory and protective functions against uncontrolled proteolysis in several disease processes. Recently we reported that cystatin M/E, which is a novel member of the cystatin gene family, has an unusually restricted expression pattern that is limited to skin. Although cystatin M/E possesses two distinct biochemical properties (it is a proteinase inhibitor and a substrate for transglutaminase) its physiological function is unknown. Disturbance of the balance between proteinases and their inhibitors can lead to irreversible damage as in chronic inflammatory reactions and tumour invasion.

OBJECTIVES

To examine the expression pattern of cystatin M/E in inflammatory conditions and neoplastic skin disorders in order to obtain possible clues on its function. Furthermore, we wished to determine whether cystatin M/E expression could discriminate between various types of neoplasia.

METHODS

Biopsy material of normal skin, atopic dermatitis and psoriatic lesional skin, healing excisional wounds in healthy volunteers, and several types of epidermal neoplasia (keratoacanthoma, actinic keratosis, basal cell carcinoma and squamous cell carcinoma) were used in this study. For comparison we studied the expression of cystatin M/E in squamous neoplasias from non-cutaneous origin. Affinity-purified polyclonal antibodies against cystatin M/E were used for immunohistochemical detection.

RESULTS

Cystatin M/E is constitutively expressed in the stratum granulosum of normal skin, sebaceous glands, eccrine sweat glands and the infundibular epithelium of hair follicles. Expression in atopic dermatitis and psoriasis was found to extend to several layers of the stratum spinosum. In wound healing, cystatin M/E was not found in the edge of migrating keratinocytes, but it was strongly expressed in the suprabasal layers of the neo-epidermis. In epidermal neoplasias cystatin M/E expression was only found in differentiated cells and keratinized cell nests.

CONCLUSIONS

Inflammation causes cystatin M/E to be expressed in the spinous cell layers where it colocalizes with transglutaminase for which it serves as a substrate. Speculatively, increased expression of cystatin M/E is compatible with a role in controlling increased levels of cysteine proteinases during inflammation and infection. Cystatin M/E expression in neoplastic epidermis is confined to well-differentiated cells and as such does not discriminate between benign and (pre)malignant epidermal neoplasias.

Association of plasma free-3-methoxy-4-hydroxyphenyl (ethylene)glycol, natural killer cell activity and delirium in postoperative patients

We measured and compared levels of plasma free 3-methoxy-4-hydroxyphenyl (ethylene)glycol (pMHPG), a major metabolite of noradrenaline, and natural killer (NK) cell activity in 26 patients prior to their undergoing an operation for cardiovascular diseases; 11 of whom expressed delirium and 15 who did not. In conclusion, we found that pMHPG levels before an operation were higher in patients with postoperative delirium than in the patients without, while NK cell activity showed no difference between the two groups. It is possible that hyperactivity of noradrenargic neurons is connected with the development of postoperative delirium. Furthermore, we considered that measurement of pMHPG level before operation might be a useful tool to predict the occurrence of postoperative delirium.

[Efficacy of local ablation therapy for liver metastasis from colorectal cancer--radiofrequency ablation and microwave coagulation therapy]

We evaluated the efficacy of local ablation therapy in 40 patients with liver metastases from colorectal cancer. Radiofrequency ablation (RFA) and/or microwave coagulation therapy (MCT) were used. Ablation therapies were performed in percutaneous, endoscopic, and operative procedures. The regional recurrence rate at the therapeutic sites was 15% (median follow-up period of 2.5 years). The average surgical margin in the operative ablation group was 11 mm. The cumulative 5-year survival rates were 37% in the local ablation, 41% in the hepatic resection, and 5% in the regional chemotherapy groups. Major complications occurred in only two patients (one biliary fistula and one liver abscess). Together these observations indicate that local ablation therapy is a radical and safe locoregional therapy that provides adequate local control and contributes to long survival.

Immunohistochemical analysis of distribution of RON receptor tyrosine kinase in human digestive organs

The immunohistochemical distribution of RON receptor tyrosine kinase in digestive organs of both human fetus and adult, including the esophagus, stomach, duodenum, small intestine, colon, rectum, liver, gallbladder, pancreas, and spleen, was investigated semiquantitively using an affinity-purified rabbit polyclonal antibody. RON was observed to be widely distributed throughout various digestive organs and cell types in humans. The immunoreactivity for RON was observed in the epithelium of the esophagus, small intestine, colon, hepatocytes, Kupffer cells, and splenic macrophages both in the adult and the fetus, suggesting that the MSP/RON signaling pathway possesses the proper biological properties to possibly be involved in morphogenesis or differentiation of cells in these organs and cell types. Several organs differed in immunoreactivity between adult and fetus. No immunoreactive cells were found in the pancreas of adults; however, immunoreactivity was observed in acinar cells and in some of the duct or ductular cells and endocrine cells of the islet of the fetus. Similarly, immunoreactivity was not observed in gastric mucosa except in the intestinal metaplastic cells in adults; however, immunoreactivity was found in the foveolar epithelium of the stomach of the fetus. Although the biological significance of RON in malignancy is unclear, the presence of RON immunoreactivity in the fetus and it lack in the adult may indicate that RON is a oncofetal substance in human pancreas and stomach.

Clinical significance of circulating cancer cells in peripheral blood detected by reverse transcriptase-polymerase chain reaction in patients with breast cancer

Detection of breast cancer micrometastases based on specific genetic markers may provide useful information to justify appropriate therapeutic strategies. We examined the presence of a carcinoembryonic antigen (CEA) messenger RNA(mRNA) in the peripheral blood of 32 patients with varying stages of breast cancers by means of the reverse transcriptase-polymerase chain reaction (RT-PCR) assay prior to and after the curative operation. CEA mRNA were detected in the peripheral blood samples from 12 (38%) out of 32 breast cancer patients prior to surgery. Among 12 CEA mRNA-positive patients prior to surgery, 4 (33.3%) relapsed from breast cancer within 2 years after surgery. Moreover, CEA mRNA was detected in the peripheral blood samples obtained prior to surgery in 3 out of 11 patients (27.2%) with a stage I disease. One out of three of these patients had a relapse in lung. There were four patterns of CEA mRNA expression, ( +, + ), (+, -), (-, + ), and (-, -) in the pre- and post-operative blood samples. In 12 CEA mRNA-positive patients submitted to surgical resection of the primary tumor, persistence of CEA mRNA expression was observed in five patients (+, +) within a month after surgical treatment. Three out of these 5 patients (60%) relapsed from breast cancer within 2 years after surgery. In 7 other patients (+, -), CEA mRNA expression was not detected within a month after tumor removal, and recurrence occurred in 1 out of the 7 patients (14%) within 2 years after surgery. In 19 patients, CEA mRNA expression was not detected in pre- or post-operative blood samples (-, -). There was a patient whose blood sample was negative for CEA mRNA before the operation, but changed to show a positive result after surgery (-,+). No recurrence was found in 20 of CEA mRNA-negative patients prior to surgery (-, +), (-, -). This study suggested that the presence of CEA mRNA expression in preoperative peripheral blood sample represent the progression of the disease, especially the risk of hematogenous metastasis in the patients in spite of their clinical stage, and the presence of CEA mRNA in the postoperative blood sample may represent the evidence of a residual disease. Thus consideration might be given for adding combined multi-modal therapy.

Relationship between plasma cytokine concentration and multiple organ failure in patients with acute pancreatitis

The dynamic aspects of circulating cytokines and cytokine modulators and their relationship with development of multiple organ failure (MOF) in patients with acute pancreatitis were analyzed. All cytokine and C-reactive protein levels in the circulation were higher than those in the MOF group. In particular, plasma concentrations of soluble tumor necrosis factor receptors (sTNF-RI and sTNF-RII) were significantly higher in patients with MOF than in those without even at admission. Furthermore, plasma concentrations of sTNF-Rs and interleukin-1 (IL-1) receptor antagonist (IL-1ra) were much higher than those of their counterparts, TNFalpha and IL-beta, respectively. These results suggest that the plasma concentrations of sTNF-Rs are useful predictors for the development of MOF, and actions of TNF-alpha and IL-1beta could be regulated by their modulators (soluble receptor and receptor antagonist, respectively) in the pathologic condition of severe acute pancreatitis.

Augmentation of UDP-GalNAc: Fucalpha1-2Gal alpha1-3 N-acetylgalactosaminyl transferase activity in nitrosamine-induced hamster pancreatic cancers

Pancreatic cancers induced by N-nitrosobis(2-oxopropyl)amine (BOP) in hamsters produce blood group-A antigen (BG-A Ag), which is not present in the normal pancreas. To understand the neo-expression mechanism of BG-A Ag, we examined uridine diphosphate (UDP)-N-acetylgalactosamine (GalNAc): fucose (Fuc) alpha1-2 galactose (Gal) alpha1-3 GalNAc transferase (alpha1-3 GalNAc Tf) activity, the enzyme responsible for BG-A production. The specific activity of alpha1-3 GalNAc Tf in pancreatic cancers was approximately 8,000 nmole/g protein/h, whereas it was absent from the normal pancreas. Although the antrum and colon express A-Tf and BG-A Ag, the divalent cation requirements of alpha1-3 GalNAc Tf in these tissues were different from those of cancers. These results suggest that alpha1-3 GalNAc Tf is activated during BOP-induced pancreatic carcinogenesis, and that there are multiple alpha1-3 GalNAc Tf isozymes present in hamster tissues.

Presence of RON receptor tyrosine kinase and its splicing variant in malignant and non-malignant human colonic mucosa

The presence of RON and its variant isoform in malignant and non-malignant human colonic tissues was examined by immunohistochemistry using paraffin-embedded sections and RT-PCR analysis followed by direct sequencing of PCR product using RNAs isolated from frozen tissues. In normal colonic mucosa, RON was uniformly expressed in crypt cells, especially in the bottom of crypta. On the other hand, the expression was distributed heterogeneously in adenomas and in colon cancer. The expression of RON was significantly related to the degree of differentiation of colon cancer and the deletion of the expression was observed in colon cancer specimens with high incidence. The RT-PCR analysis of RNA isolated from non-malignant and malignant colonic tissue revealed the presence of two RON mRNA isoforms with 432-bp and 286-bp. Direct sequencing of major product of 432-bp was revealed to be identical to that of human wild-type RON. On the other hand, major product of 286-bp was revealed to be almost identical to that of a splicing variant of RON transcript which has been found in human gastric cancer cell line, KATO-III. The results obtained in this study may indicate that both wild-type RON and its variant isoform play an important role in regulating the normal function of colonic mucosa such as differentiation and motile activity and the expression of both wild-type RON and its variant isoform could be considered to be reduced during malignancy of human colonic mucosa.

No-touch isolation technique reduces intraoperative shedding of tumor cells into the portal vein during resection of colorectal cancer

BACKGROUND

The mutant-allele-specific amplification (MASA) method is capable of detecting 1 genetically altered tumor cell among thousands of normal cells. The MASA enabled us to detect occult tumor cells undetectable by histopathologic examination of lymph nodes and blood samples.

METHODS

To investigate whether tumor manipulation during operation enhances cancer cell dissemination into the portal vein with use of MASA and to assess the effect of the no-touch isolation technique in the treatment of colorectal cancers, 27 colorectal cancers (17 were operated on conventionally and 10 were operated on according to the no-touch isolation technique) were screened for mutations in K-ras or p53. We next examined blood samples of the portal vein collected before, during, and after manipulation of tumors, using MASA to look for the specific mutation found in the primary tumors.

RESULTS

Somatic mutations were identified in 18 of these primary tumors (11 were in the conventional resection technique group and 7 were in the no-touch isolation technique group). In 8 of 11 (73%) conventional resection technique cases, we identified the same genetic alteration of the primary tumor in the portal blood during operation, whereas only 1 patient (14%) in the no-touch isolation technique group had a positive result.

CONCLUSIONS

The no-touch isolation technique may be useful to prevent cancer cells from being shed into the portal vein during surgical manipulation.

Prognostic values of MUC-1 molecule expressing cytokine receptor-like epitope and DF3 in patients with gastric carcinoma

As recently reported, DF3/MUC-1 molecules having cytokine receptor-like sequences (CRL) at the extracellular region, are likely to function in signal transduction pathways. To elucidate the functional significance of CRL expressed on the DF3/MUC1 molecule, immunohistochemical localization of CRL and/or DF3 was investigated in cases of 115 patients with gastric carcinomas, treated by surgical resection. CRL was detected in 65 of 115 patients (56.5%), DF3 in 85 (73.9%), and both DF3 and CRL in 52 (45.2%). The combined immunohistochemical analysis of CRL and/or DF3, revealed that simultaneous expression of DF3 and CRL (DF3+/CRL+) significantly correlated to lymph node metastasis and to blood vessel invasion, and that patients with DF3+/CRL+-tumors survived for a significantly shorter period after surgery than did the other three groups (DF3+/CRL-, DF3-/CRL+, and DF3-/CRL-). Multivariate analysis showed independent prognostic significance for DF3+/CRL+ expression (hazard ratio [HR]=2.733, P=0.0085), and surgical cure (HR=4.334, P=0.003). To investigate the biological role of the simultaneous expression of DF3 and CRL, we constructed DF3-/CRL+ (NR-MC-38) and DF3+/CRL+ (R-MC-38) cells by transducing a mouse colon adenocarcinoma cell line MC-38 expressing neither DF3 nor CRL with MUC-1 cDNA containing ten tandem repeats (R-MC-38) or MUC-1 cDNA devoid of tandem repeats (NR-MC-38). R-MC-38 (DF3+/CRL+) cells were more invasive than NR-MC-38 (DF3-/CRL+) and MC-38 (DF3-/CRL-) cells. When these transfectants were incubated with pAb CRL, the invasiveness of R-MC-38 (DF3+/CRL+) was strikingly elevated over the case with native MC-38 (DF3-/CRL-) and NR-MC-38 (DF3-/CRL+) cells. The pAb CRL-induced invasiveness of R-MC-38 cells was inhibited by adding mAb DF3 or CRL peptides together with pAb CRL. These results suggest that an expression of DF3/MUC1 is highly associated with cell-invasiveness, and the DF3/MUC1-associated invasiveness is amplified by CRL. Thus DF3+/CRL+-MUC-1 molecule seems to be closely involved in a poor prognosis for gastric cancer patients.

Induction of HLA-unrestricted and HLA-class-II-restricted cytotoxic T lymphocytes against MUC-1 from patients with colorectal carcinomas using recombinant MUC-1 vaccinia virus

We recently reported that immunization with a recombinant MUC-1 vaccinia virus (rVMUC-1) protected C57BL/6 mice from challenge with DF3/MUC-1-positive syngeneic tumors. To elucidate whether anti-MUC-1 tumor immunity, especially MUC-1-specific cytotoxic T lymphocytes (CTI), can be induced in cancer patients by rVMUC-1, we stimulated the peripheral blood lymphocytes from patients with DF3/MUC-1+ or DF3/MUC-1 colon carcinomas using the autologous monocytes infected with rVMUC-1 (rVAMN). The stimulated T lymphocytes from two patients with DF3/MUC-1-positive colorectal carcinomas (rVPY+T and rVPW+T) demonstrated HLA-unrestricted cytotoxicity against MUC-1, whereas those from the patient with DF3/MUC-1-negative colon carcinoma (rVPA-T) did not. The HLA-unrestricted cytotoxicity was demonstrated by the CD8+ T cells possibly recognizing an epitope present on the tandem repeats. Adoptive immunotherapy who performed three times with patient PY, at 4-week intervals. The adoptive transfer of the first stimulated lymphocytes, demonstrating a high level of HLA-unrestricted cytotoxicity against MUC-1, resulted in the significant reduction of the liver metastasis of patient PY. However, HLA-unrestricted cytotoxicity against MUC-1 was extremely reduced at the second transfer and finally eliminated at the third, whereas the CD4+ T cells demonstrating HLA-class-II-restricted cytotoxicity against MUC-1 predominantly proliferated at the third adoptive immunotherapy treatment. The liver metastasis and the serum levels of tumor markers (carcinoembryonic antigen CA19-9) demonstrated a rapid and marked increment after the second transfer and especially after the third. These results suggest that the HLA-unrestricted cytotoxic CD8+ T cells against MUC-1, induced in patients with DF3/MUC-1+ colorectal carcinomas using rVMUC-1, correlate with the antitumor activity in vivo.

[Involvement of cytokines in invasion and metastasis of colon cancer]

Despite improvement in early diagnosis, surgical techniques, and general patient care, most deaths of cancer patients result from metastases. Recent studies have revealed that cytokines produced by cancer cells or by stromal cells play an important role into development the cancer metastasis. The formation of a cancer metastasis involves several major steps: 1) extensive vascularization; 2) local invasion; 3) adherence either to capillary endothelial cells or to subendothelial basement membrane; 4) extravasation; and 5) proliferation. In colon cancer, several cytokines such as growth factors, inflammatory cytokines, and angiogenic factors have been confirmed to be involved in each step of metastasis. This paper summarizes the involvement of cytokines in the development of invasion and metastasis in colon cancer.

[Clinical evaluation of Azasetron Hydrochloride: a new selective 5-HT3 receptor antagonist--antiemetic profile and plasma concentration in transcatheter arterial chemoembolization using CDDP for unresectable hepatocellular carcinoma]

We performed a clinical evaluation on the antiemetic profile and the plasma concentration of Azasetron Hydrochloride (a new selective 5-HT3 receptor antagonist), in transcatheter arterial chemoembolization using CDDP for unresectable hepatocellular carcinoma. Antiemetic effects were examined in 32 patients in the serotone group (administration of serotone 10 mg + methylprednisolone 125 mg) and in 77 patients of the control group (administration of metoclopramide 20-30 mg + methylprednisolone 500 mg). The response rate and the CR ratio in serotone group was 97% and 66%, respectively. These results were statistically higher than in the control group. Although all patients had chronic liver diseases, no side effects and complications related to administration of serotone were observed. The average area under the concentration (AUC) curve of plasma serotone in five patients with liver cirrhosis was 531 ng.h/ml, which was greater than that of a healthy volunteer. In conclusion, serotone is a new, safe and useful antiemetic drug in TACE therapy for hepatocellular carcinoma.

Signal transduction pathway of the induction of cell motility in hamster pancreatic ductal adenocarcinoma cell

Recently, we reported that low (PC-1)- and high-invasive cell lines (PC-1.0) were established on the basis of hamster pancreatic ductal adenocarcinomas, and PC-1.0 cells were secreting the dissociation factor in the supernatant (DF-CM) which induced cell dissociation and enhancement of cell motility. The cell motility of PC-1.0 is about 6 times as high as that of PC-1, which was continuously maintained in an autocrine fashion by DF-CM. In contrast, cell motility of PC-1 was rapidly induced by DF-CM with a high level of induction of endogenous c-fos mRNA and returned to a basal level within 6 h. The inhibition experiment using antisense oligonucleotides to c-fos indicated that the high level of induction of c-fos mRNA observed in the DF-CM-treated PC-1 cells was closely associated with their induction of cell motility. To elucidate these differences of responses against DF-CM between PC-1 and PC-1.0, signal transduction pathways of induction of the cell motilities were analyzed, using protein kinase C (PKC) inhibitor, 12-O-tetradecanoylphorbol-13-acetate, cyclic AMP antagonist, and cyclic AMP agonist. The transiently enhanced cell motility of DF-CM-treated PC-1 cells was completely inhibited by the cyclic AMP antagonist, and the cyclic AMP agonist was able to induce a similar pattern of induction of cell motility in PC-1 cells to DF-CM. On the other hand, the highly enhanced cell motility of PC-1.0 was completely inhibited by protein kinase C inhibitor, but not by cyclic AMP antagonist. These results suggest that cell motility of low-invasive PC-1 cells is under control through cyclic AMP-dependent protein kinase A, while the protein kinase C pathway seems favorable for high-invasive PC-1.0 cells to maintain the continuously enhanced cell motility responsible for their high invasiveness.

Immunohistochemical expression of SKALP/elafin in squamous cell carcinoma of the oesophagus

In this study, the immunohistochemical expression of a new inducible elastase inhibitor, SKALP (skin-derived anti-leucoproteinase)/elafin, in the tissue of squamous cell carcinoma and uninvolved oesophageal mucosa was studied using a polyclonal rabbit anti-serum against SKALP/elafin. The results were compared with the immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and the TUNEL assay in serial sections. In non-malignant oesophageal mucosa, the expression of SKALP/elafin was localized in the cells of the stratified zone overlying the PCNA-positive basal zone. In oesophageal cancer, the incidence of the expression was significantly related to the degree of the differentiation of the tumour. Characteristically, the expression was almost limited in tumour cell nests that had a clear squamous phenotype. In tumour cell nests, the expression of SKALP/elafin was localized in the cells overlying PCNA-expressing cells and no expression was found in the cells that expressed PCNA; DNA fragmentation was often observed in the same cell layers as those in which SKALP/elafin immunoreactivity was found. This enzyme inhibitor is speculated to be involved in the induction of the cell differentiation and apoptosis of human squamous cell carcinoma cells of the oesophagus.

Production of group II phospholipase A(2) in advanced gastric cancer

We examined the immunohistochemical expression of membrane-associated phospholipase A(2) (M-PLA(2)), belonging to group II PLA(2), in 44 advanced gastric cancers, using the ABC method and monoclonal antibody anti-human M-PLA(2). M-PLA(2) mRNA was also examined in the same rumours by Northern blot analysis. In addition, the content of M-PLA(2) protein and prostaglandin E(2) (PGE(2)) in the malignant lesion and in the non-malignant gastric mucosa was examined. The expression was detected in cancer cells in 31 out of 44 advanced gastric cancer tissues (70.4%) by the ABC method. M-PLA(2) mRNA was detected in 36 out of 44 gastric cancer tissues (81.8%), and the density was observed to be higher in tumour tissues than in the adjacent nonmalignant gastric mucosa. The M-PLA(2) protein was detected both in malignant tissues and in non-malignant gastric mucosa, and the content of M-PLA(2) protein was significantly higher in malignant tissues than in the non-malignant gastric mucosa. There was a significant positive correlation between the expression of M-PLA(2) mRNA and the amount of M-PLA(2) protein. PGE, was also detected in the malignant tissues and in the non-malignant mucosa. The content of PGE, was significantly higher in the former. These results indicate that M-PLA(2) is produced both in malignant and nonmalignant cells of the stomach, the former producing higher amounts of this enzyme than the latter. M-PLA(2) may be involved in cancer progression through its function or through the function of products of this enzyme's action such as PGE(2) in gastric cancer.

Immunohistochemical expression of the c-kit proto-oncogene product in human malignant and non-malignant breast tissues

The immunohistochemical expression of c-kit proto-oncogene product in 57 breast cancer tissues was studied using anti-c-kit proto-oncogene product antibody in comparison with 20 normal breast tissues and 58 benign breast tumours. In normal breast tissues, the c-kit proto-oncogene product was strongly expressed on cell membrane and/or cytoplasm of alveolar and ductal cells. The immunoreactive score (IRS) of c-kit proto-oncogene product in normal mammary epithelia was 6.22 +/- 2.11 (mean +/- s.d.). In benign breast diseases, the c-kit proto-oncogene product was detected heterogeneously with a reduced IRS (3.33 +/- 2.44). In breast cancer tissues, the expression of the immunoreactive c-kit proto-oncogene product was often deleted and the average IRS was significantly reduced compared to those of normal breast tissues or benign breast diseases tissues. Among benign diseases, the average IRS of intraductal papilloma was significantly reduced (1.34 +/- 1.70) and the staining intensity and pattern were found to be similar to those seen in breast cancer. The results in this study suggested that the c-kit proto-oncogene product is correlated with the growth control or the differentiation of normal breast epithelium. Also, the loss of the expression of this protein may indicate the change of the signal transduction in relation to malignant transformation in human mammary epithelium.

Characterization of cancer cell dissociation factor in a highly invasive pancreatic cancer cell line

BACKGROUND

Two pancreatic cancer cell lines, the highly invasive and metastatic cell line PC-1.0 and the weakly invasive and rarely metastatic cell line PC-1, were established from a pancreatic ductal carcinoma induced by N-nitrosobis (2-oxopropyl) amine in a Syrian golden hamster.

METHODS

The cancer cell dissociation activity in serum-free conditioned medium of PC-1.0 cells was partially purified using a heparin column, a hydroxylapatite column, anion exchange, and gel filtration high-performance liquid chromatography. Several biologic properties of the partially purified activity were evaluated.

RESULTS

Two cell lines exhibited different growth morphologic changes in vitro: the weakly invasive cell line PC-1 formed islandlike colonies, and the highly invasive cell line PC-1.0 grew mainly as single cells. The conditioned medium of PC-1.0 cells induced dissociation of islandlike colonies and morphologic changes of PC-1 cells to elongated cells, with a high frequency of pseudopodia formation similar to the morphologic findings of PC-1.0 cells. The dissociation activity did not bind to the heparin column and had an apparent molecular mass of > 400 kDa, as deduced from gel filtration. Several immunoreactive proteinous bands were observed in immunoblotting analysis using a polyclonal blocking antibody. The partially purified activity enhanced cell motility, chemoinvasion, and cell adhesion to plastic plates and fibronectin.

CONCLUSIONS

Highly invasive and metastatic PC-1.0 cells produce a soluble proteinous factor, called "dissociation factor" (DF), which induces cell dissociation of weakly invasive and rarely metastatic PC-1 cells. It seems likely that DF has a role in tumor invasion and metastasis.

Elevation of circulating interleukin 6 after surgery: factors influencing the serum level

To investigate the effect of surgical trauma and other factors on the postoperative elevation of serum interleukin 6 (IL-6), we examined changes in IL-6 concentration after major thoracoabdominal surgery. Serum IL-6 levels reached the maximum concentration on the first postoperative day in all 38 patients, with peak ranging from 1400.8 +/- 383.4 pg/ml (mean +/- SEM) to 29.8 +/- 3.8 among six groups who underwent surgery at different sites. The IL-6 peak was significantly correlated with surgical trauma as defined by the operation length and the volume of blood loss during surgery (r = 0.554, P < 0.01 and r = 0.427, P < 0.01, respectively). The peak concentration of serum IL-6 in patients undergoing esophagectomy was significantly higher than in those undergoing pancreaticoduodenectomy (P < 0.05), despite a similar degree of surgical trauma defined by the operation length and volume of blood loss during surgery. Peak IL-6 concentration observed in a patient who underwent esophagectomy was about 100-fold greater in fluid drained from the thorax than in the peripheral blood. IL-6 mRNA was demonstrated in leukocytes from thoracic and abdominal exudate at 6, 24 and 48 h after surgery. In contrast, IL-6 mRNA could not be detected in leukocytes from the peripheral blood. Similar findings were also observed for interleukin 8 (IL-8). However, interleukin 1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) were detected only once after surgery in the drainage fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of cerebral glioblastoma with extensive cerebrospinal fluid dissemination: diagnostic value of immunohistochemical examination and MR imaging

A 9-year, 6-month-old boy presented with peripheral-type multiple cranial nerve palsy due to extensive cerebrospinal fluid (CSF) dissemination of intracranial glioblastoma multiforme. Tissue obtained from biopsy did not stain for glial fibrillary acidic protein (GFAP). The relationship between GFAP-negative tumor cells and extensive CSF dissemination agreed with recent reports. Magnetic resonance imaging with gadolinium-DPTA enhancement clearly depicted not only the cranial meningeal dissemination but also spinal metastasis. Magnetic resonance imaging showed undoubted usefulness in demonstrating disseminated glioblastoma.

The role of tumor necrosis factor-alpha in the aggravation of cerulein-induced pancreatitis in rats

Severe acute pancreatitis is often complicated by intraperitoneal infection, resulting in multiple organ failure (MOF). It is known to elevate serum tumor necrosis factor (TNF-alpha) in patients with sepsis and/or MOF. In order to study the role of TNF-alpha in the aggravation of acute pancreatitis, we investigated TNF-alpha production by peritoneal macrophages in acute pancreatitis rat using the cerulein-induced pancreatitis model. TNF-alpha production by isolated peritoneal macrophages following lipopolysaccharide (LPS) stimulation was significantly increased in pancreatitis rats as compared with nonpancreatitis control rats (p < 0.001). Serum TNF-alpha activity was elevated following intraperitoneal administration of LPS as the septic challenge both in pancreatitis rats and in control rats, being significantly higher in the former (p < 0.05). Histological findings and liver function tests revealed that LPS induced more severe liver damage in pancreatitis rats than in control rats within 24 h after LPS administration. These results indicate that increased TNF-alpha production by peritoneal macrophages in acute pancreatitis augmented LPS-induced liver injury and suggest the possibility that TNF-alpha may play a role in the development of MOF during acute pancreatitis complicated by intraabdominal sepsis.

Expression of group-II phospholipase A2 in malignant and non-malignant human gastric mucosa

The expression of Group-II phospholipase A2 (M-PLA2) was analysed immunohistochemically in malignant, non-malignant (including atrophic, hyperplastic, pseudopyloric metaplastic and intestinal metaplastic) and normal human gastric mucosae. M-PLA2 was consistently detected in the stem cell lineage, pseudopyloric metaplasia and the generative cells of hyperplastic foveolar epithelium and intestinal metaplasia (IM). In IM, the appearance of M-PLA2 was found to be closely related to the degree of development of the brush borders on columnar cells and was especially prominent at dense brush borders. Paneth cells of IM, particularly their secretory products, were strongly immunoreactive for M-PLA2. In gastric cancer, the expression of M-PLA2 was detected exclusively in cancer cells with a low grade of differentiation, and seemed to be intensified in the invading zone of the tumour. These observations suggest that the expression of M-PLA2 is associated with the proliferative kinetics and regeneration of human gastric mucosa, and may indicate a physiological relationship between its expression and metaplasia of small intestinal type. Moreover, the appearance of M-PLA2 may be related to the invasive ability of gastric cancer.

Production of scatter factor-like activity by a nitrosamine-induced pancreatic cancer cell line

Two hamster pancreatic cancer cell lines, PC-1 and PC1.0, established from N-nitrosobis(2-oxopropyl)amine-induced pancreatic ductal/ductular adenocarcinomas exhibit different growth patterns. PC-1 cells, which produce well differentiated adenocarcinomas in vitro after allogeneic inoculation, form cell aggregates and characteristic island-like structures in vitro. PC1.0 cells, which produce poorly differentiated tumors in vivo, form dispersed colonies in vitro. Conditioned medium prepared from PC1.0 cells inhibits PC-1 cells from forming island-like colonies. The conditioned medium also prevents several human pancreatic carcinoma cell lines, HPAF, CD11 and CD18, from forming compact colonies. These properties are similar to those described previously as scatter factors. The scatter factor-like activity is heat-labile, acid-stable, non-dialyzable, trypsin sensitive and unaffected by reducing agents. The activity is not suppressed by addition of heparin, and it does not bind to heparin. In addition, the scatter phenomenon is not reproduced by acidic or basic fibroblast growth factor, epidermal growth factor or transforming growth factor-beta 1. Based on these findings, it appears that the scattering activity produced by PC1.0 cells differs from the scatter factors that have been identified in other systems.

Immunohistochemical localization of group II phospholipase A2 in human pancreatic carcinomas

The immunohistochemical localization of group II phospholipase A2 (PLA2) in normal fetal and adult human pancreases, 5 chronic pancreatitis, and 30 pancreatic ductal carcinomas was investigated. Furthermore, pancreatic carcinoma cases were correlated with histologic type, tumor size, vascular involvement, lymphatic involvement, perineural invasion, lymph node metastasis, amount of interstitial tissue in the tumor, growth pattern of the tumor, and clinical stage. In the normal pancreases, almost all of acinar cells and a few cells of small and large ducts were immunoreactive in a supranuclear pattern. In chronic pancreatitis, immunoreactivity was retained in several acini, islet cells, and ductal cells, but the staining was diminished in acinal cells of atrophic lobules. A strong immunoreactivity was found in the cells of hyperplastic ducts. In pancreatic ductal carcinomas, the immunoreactivity was observed in 25 cases (83%). Eighteen of 25 (72%) immunoreactive cases showed a cytoplasmic granular or luminal surface pattern, both of which were not observed in the normal pancreas. Among the clinicopathological parameters of pancreatic cancer, the incidence of expression of this enzyme was significantly higher in infiltrative type cancers than in expansive and localized tumors. Furthermore, the expression of group II PLA2 was significantly higher in the tumor with larger amount of interstitial tissue than in that with smaller amounts of interstitial tissue. These results suggest that expression of group II PLA2 in human pancreatic ductal carcinomas is possibly involved in the proliferation of interstitial tissue directly or indirectly through prostaglandin production.

Relationship between blood group-A antigen expression and malignant potential in hamster pancreatic cancers

The loss of expression of the ABH blood group antigens is suggested to be associated with more aggressive behavior of cancers. We have compared the growth behaviors of two hamster pancreatic cancer cell lines with different blood group-A expressions. PC-1.0 cells, which expressed blood group-A antigen poorly, showed a faster growth in vitro and in vivo when implanted into the pancreas of homologous animals, whereas PC-1.2 cells, all of which express the antigen, had a slower growth rate both in vitro and in vivo. PC-1.0 also tended to metastasize, whereas PC-1.2 cells grew primarily locally. The allografts of both PC-1.2 cells (PC-1.2AG) and PC-1.0 cells (PC-1.0AG) and the metastases of PC-1.0 cells expressed blood group A antigen in a similar rate. There was no significant difference in the number of A-antigen positive cells (A+) between the PC-1.2AG and PC-1.0AG, although the expression of A antigen in PC-1.0AG showed a greater heterogeneity. The combined immunohistochemistry and autoradiography did not show any significant differences in the labeling index of A+ or A- cells between the two allografts. Thus, the results indicate that blood group A antigen expression is unrelated to malignancy in this model. The faster growth rate of PC-1.0 cells may be due to their shorter cell cycle.

Light microscopic immunohistochemical analysis of the distribution of group II phospholipase A2 in human digestive organs

The light microscopic and immunohistochemical distribution of human Group II phospholipase A2 (M-PLA2) in digestive organs of both human fetus and adult, with a new monoclonal antibody (MAb) against M-PLA2, was investigated semiquantitatively. The immunoreactivity was distributed similarly in the adult and fetal epithelium of the esophagus, duodenum, and small intestine, and in the acinar, islet, and duct cells of the pancreas. The epithelium of adult gallbladder was immunoreactive. Paneth cells, especially the secretory apparatus, were strongly immunoreactive. Hepatic Küpffer cells and macrophages of the adult spleen were also immunoreactive. These results suggest that these cells contain secretory-type Group II PLA2, which may be involved in host defensive mechanisms, such as phagocytosis in human digestive organs. In the adult colon, the immunoreactivity was observed only in the ascending colon and was not found in the transverse, descending, sigmoid, or rectal colon. The immunoreactivity was not found in fetal colon. Similarly, immunoreactivity was found in hepatocytes and Küpffer cells of adult liver but not in fetal liver. By contrast, strong immunoreactivity was observed in the epithelium of the fetal stomach but not in adult stomach except in gastric neck cells. This suggests that the expression of M-PLA2 may be related to cell differentiation in particular organs.

Effects of acute and repeated alcohol ingestion on hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal functioning in normal males

We investigated the effects of acute and repeated alcohol ingestion on plasma levels of hormones associated with the functioning of the hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-adrenal (HPA) systems in normal males. In the first experiment, 7 normal male subjects were given ethanol (1.3 g/kg) in the form of a 43% alcohol solution of whiskey and water over a 30-min period (from 19:00 h to 19:30 h); blood samples were collected 30 min and immediately before the beginning of alcohol ingestion and then at intervals of 30 min for 180 min. Blood ethanol levels rose sharply and reached their maximum at 60 min, remaining above 1.0 mg/ml until 180 min. Prolactin levels increased, reaching a peak at 60 min, gradually returning to the initial value at 180 min. Decreased testosterone levels were observed only at 30 min. Luteinizing hormone (LH), adrenocorticotrophic hormone (ACTH) and cortisol levels did not show any increases. In the second experiment, 9 normal males were given the same dose of alcohol, but this was given on 7 consecutive evenings and the hormonal changes were examined on the 1st and 7th days, only at 30 and 60 min after alcohol ingestion began (during the period that blood ethanol levels were ascending to their peak). The results on the 1st day reconfirmed the findings in the first experiment and on the 7th day, the last alcohol ingestion produced increases in prolactin levels and decreases in testosterone levels at 30 and 60 min, but did not change other hormone levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Membrane-associated phospholipase A2 stimulates DNA synthesis in two murine fibroblasts

The effect of human membrane-associated phospholipase A2 (M-PLA2) on DNA synthesis in fibroblasts was examined in order to clarify its biological function. Human M-PLA2 added exogenously to the fibroblast cell lines Swiss 3T3 and BALB/3T3 was found to augment their DNA synthesis. This stimulation of DNA synthesis was not affected by treatment with indomethacin. Our results suggest that human M-PLA2 itself has a mitogenic effect on fibroblasts independent of arachidonate products such as prostaglandins.

Abundant expression of immunoreactive endothelin 1 in mammary phyllodes tumor: possible paracrine role of endothelin 1 in the growth of stromal cells in phyllodes tumor

Immunoreactive endothelin 1 (irET-1) concentrations were measured in extracts prepared from 4 phyllodes tumors and 14 fibroadenomas. irET-1 was detectable in all tissue extracts by specific radioimmunoassay, and the mean concentration of irET-1 was 18-fold and 27-fold higher in tissue extracts from phyllodes tumors than in those from intracanalicular fibroadenomas and pericanalicular fibroadenomas, respectively. Reverse-phase high-performance liquid chromatography coupled with radioimmunoassay in the extracts from phyllodes tumors revealed one major irET-1 component corresponding to human standard ET-1. Furthermore, immunocytochemical staining for ET-1 revealed that numerous ET-1-immunoreactive cells were seen in the epithelial cells but not in the stromal cells, suggesting that ET-1 is synthesized by the epithelial component of phyllodes tumors. A possible paracrine role of ET-1 in the growth of this rare tumor which is characterized by its prominent stromal cellularity is discussed.

Expression of blood group-related antigens, ABH, Lewis(a), Lewis(b), Lewis(x), Lewis(y), CA19-9, and CSLEX1 in early cancer, intestinal metaplasia, and uninvolved mucosa of the stomach

The expression of blood group-related antigens, A, B, H type 2, Lewis type 1 (Lewis(a) [Le(a)] and Lewis(b) [Le(b)]), Lewis type 2 (Lewis(x) [Le(x)] and Lewis(y) [Le(y)]), sialylated Le(a) (CA19-9), and sialylated Le(x) (CSLEX1), was analyzed sequentially with immunohistochemical methods in early gastric cancer, intestinal metaplasia, and uninvolved gastric mucosa obtained from 35 surgical specimens of patients who underwent gastrectomy. The high incidence of the inappropriate expression of Lewis type 1 antigens and the deletion of H and Lewis type 2 antigens was observed similarly in patients with cancer and intestinal metaplasia. The acquisition of CA19-9 and CSLEX1 and the deletion of B antigen frequently were found in intestinal-type cancer and all types of intestinal metaplasia. The simultaneous deletion of A antigen was detected only in the combination of intestinal-type cancer and incomplete-type intestinal metaplasia. Thus the present study shows that similar changes of tissue antigenicities exist in early gastric cancer and intestinal metaplasia.

Interleukin-8 is constitutively and commonly produced by various human carcinoma cell lines

We examined the production of interleukin-8 and interleukin-6 by 30 human carcinoma cell lines. Serum levels of interleukin-8 were measured in 14 patients with hepatocellular carcinoma by enzyme-linked immunosorbent assay and Northern blotting. Furthermore, serum interleukin-8 was also investigated in a nude mouse bearing a tumor of the HuH7 hepatoma cell line producing interleukin-8. Of the 30 cell lines, 29 (96.7%) constitutively produced interleukin-8, and 19 of the 29 (65.5%) were high producers (> 1 ng/ml culture supernatant). Among the high producers, 4 cell lines released both interleukin-8 and interleukin-6. Interleukin-6 was constitutively produced by 17 of the 30 (56.7%) cell lines, 4 of which (23.5%) were high producers (> 1 ng/ml). By Northern blot analysis, mRNAs of interleukin-8 and interleukin-6 were detected in producing cell lines. Of 14 patients with hepatocellular carcinoma 4 (28.5%) showed increased levels of serum interleukin-8. Furthermore, inoculation of the HuH7 hepatoma cell line which produced the highest amount of interleukin-8 into a nude mouse resulted in tumor production accompanied by an elevated level of human interleukin-8 (646 pg/ml) in the peripheral blood. Thus, interleukin-8 is constitutively and commonly produced by various carcinoma cell lines. The production of interleukin-8 by carcinoma cells may be related to the elevation of serum interleukin-8 in patients with hepatocellular carcinoma. Finally, these cell lines may be valuable for studying the relationship between interleukin-8 and cancer.

Vitamin B12 accelerates re-entrainment of activity rhythms in rats

The effects of methyl vitamin B12 (5-6 mg/kg, p.o.) on the entrainment of circadian running wheel activity rhythm to a new lighting schedule were measured in rats. After the light-dark (LD) cycle was abruptly reversed, rats given vitamin B12 took less time to entrain their circadian locomotor activity rhythm to the new cycle than did controls. This result indicates that vitamin B12 accelerates the reentrainment of the mammalian circadian activity rhythm following an abrupt change in the environmental LD cycle.

Subcellular localization of blood group A substance produced by pancreatic adenocarcinoma induced in hamsters by N-nitrosobis(2-oxopropyl)amine (BOP) and by its cell line (PC-1)

The subcellular localization and biochemical characteristics of blood group A antigen were studied by immunogold methods and by SDS-PAGE and Western blotting procedures in N-nitrosobis)2-oxopropyl)amine (BOP)-induced pancreatic cancer (PC) in Syrian hamsters, in the pancreatic cancer cell line (PC-1) derived from a primary induced pancreatic cancer, and in intrapancreatic and subcutaneous transplants of PC-1 cells. Normal hamster duodenal epithelial cells expressing A antigen were compared with the normal hamster pancreas (lacking A antigen), human PC tissues from patients with blood group A and human PC cell lines. Blood group A antigen was present on the membrane of hamster duodenal cells, but was absent in the normal pancreatic cells. A antigen was localized mainly on the cell membrane of the hamster cancer cells both in vivo and in vitro. Glycoproteins with blood group A specificity were observed by SDS-PAGE and Western blotting procedures in the membrane fraction of PC-1 cells, with a major component of molecular mass of approximately 120 kd. Similar migration patterns were observed in the primary induced PC and in subcutaneous and intrapancreatic transplants of PC-1 cells. Membrane preparations from cell lines derived from two primary pancreatic cancers from patients of blood group A and from human pancreatic cell lines, CD11 and CD18, showed a major A reactive component with a molecular mass similar to that found in the hamster PC cells. These findings suggest that: (i) both the hamster and human PC cells in vitro produce glycoproteins with blood group A specificity of similar molecular masses; (ii) differences exist in the structure of the glycoprotein immunoreactive with the anti-A antigen between the normal and cancerous cells; and (iii) differences exist in the molecular mass of the anti-A reactive substance between hamsters and human PC cells and between tissues in vivo and in vitro.

Correlation between morphology and blood group-related antigen expression in pancreatic tumors induced in Syrian hamsters

Expression of blood group-related antigens (BGRAs) A, B, H, Le(b), Le(x) and Le(y) was examined immunohistochemically in neoplastic and hyperplastic lesions induced by N-nitrosobis(2-oxopropyl)amine in Syrian hamsters to determine a relationship between histological and biological patterns of the lesion and expression of BGRAs. With the exception of papillary ductal cell hyperplasia, A-antigen discriminated between the benign and malignant lesions far better than the other antigens, which showed heterogeneity in the expression of benign and malignant tumors. However, production of A-antigen decreased with the degree of tumor dedifferentiation and was absent in anaplastic regions of tumors. Marked differences were found in the expression of A- and B-antigen in tubular complexes, one of the earliest induced changes, in relation to the type of cells populating these lesions. Overall, B-antigen seemed to be associated more with benign cells than malignant cells. On the other hand, Le(x)-antigen was expressed primarily in the invasive portion of some cancers and seemed to reflect active proliferative processes.

Patterns of growth and metastases of induced pancreatic cancer in relation to the prognosis and its clinical implications

To understand high malignancy of pancreatic cancer, the growth and metastatic patterns of pancreatic cancer induced in Syrian hamsters were examined. In this model, induced tumors resemble the human disease morphologically, clinically, biologically, and immunologically. In the current study, primary-induced cancer and transplants of pancreatic cancer cell line (PC-1) into the SC tissue or pancreas of homologous hosts were used. In the primary-induced pancreatic cancer, perineural invasion was the most common path (88%), followed by lymphogenic (31%) or vascular (2%) metastases. Inoculation of PC-1 cells into the pancreas resulted in 100% tumor take within 3 weeks. Of 19 intrapancreatic allografts, all showed peritoneal invasion, 5 (26%) liver metastases, 3 (16%) lymph node metastases, 17 (89%) perineural invasion, and none vascular invasion. Even microscopic tumors were found to metastasize primarily via perineural spaces. It was also demonstrated, for the first time, that cancer cells take this route to reach distant tissues, including the lymph nodes. Intraductal spreading occurred in both primary cancers and intrapancreatic allografts either continuously or discontinuously. The patterns of discontinuous intraductal tumor expansion imitated tumor multicentricity. Although perineural invasion was the most common feature of primary cancer and intrapancreatic allografts, lymphatic, hepatic, and vascular invasion and metastases usually occurred in advanced cases. Environmental factors seem to influence expansion and metastases, as evidenced by differences in growth and in metastatic patterns between SC and intrapancreatic allografts.

Comparative histopathological findings in the pancreas of cigarette smokers and non-smokers

Although a correlation has been suggested between cigarette smoking and pancreatic cancer, studies on pathological changes in the pancreas of smokers are fragmentary. In the present study we examined histopathologically 73 pancreases obtained by autopsy from 42 heavy cigarette smokers and 31 non-smoker patients. One invasive adenocarcinoma (2 cm in diameter) and three small carcinomas (2-5 mm in diameter) were found in smokers and one small carcinoma in a non-smoker patient. Although the incidence of pancreatic cancer in smokers was higher than in non-smokers, the difference was statistically not significant. Of smokers with pancreatic cancer, 2 had lung cancer, 1 skin cancer, 1 colon cancer and 1 was free of any malignancies. Ductal changes, including mucinous or squamous cell metaplasia and papillary hyperplasia, were found with equal frequencies in both groups of patients. The type and the incidence of these ductal alterations were not related to smoking but to the age. Our results do not indicate that cigarette smoking increases the incidence of pancreatic cancer, although, the limited number of the sections of the pancreas examined, as well as exclusion of other important variables, such as alcohol, diet and diabetes weaken the value of this study.

Comparative studies on expression of tumor-associated antigens in human and induced pancreatic cancer in Syrian hamsters

The expression of blood-group-related antigens (BGRAs) in experimental primary pancreatic cancer induced by N-nitrosobis(2-oxopropyl)amine (BOP) treatment of Syrian hamsters and homologous subcutaneous transplants of this primary cancer in the cell line, PC-1, established from the primary cancer and intrapancreatic transplanted PC-1 cells were studied by histochemical and biochemical methods. Human primary pancreatic cancer; the human pancreatic cancer cell line, HPAF; and its subclones, CD11 and CD18, also were studied on a comparative basis. Histochemical analysis of BGRAs demonstrated that A, B, H, Leb, Lex, Ley, and T antigen were expressed both in vivo and in vitro in hamster and human materials in similar patterns. However, Lea, CA 19-9 and sialylated Tn antigens were not found in hamster-derived tissues. SDS-PAGE and Western blotting procedures using anti-A antigen revealed similar major bands in the membrane fractions of both human and hamster pancreatic cells between 97 and 200 kdalton. Among other human pancreatic cancer-associated antigens, TAG-72, CA 125, and 17-1A were detected immuno-histochemically in the hamster tumors both in vivo and in vitro, in a pattern similar to that seen in human pancreatic cancer. Tumor antigen DU-PAN-2, associated with human pancreatic cancer, was found infrequently in hamster pancreatic cancer specimens. These results indicate that the experimental hamster pancreatic cancer model provides a unique tool for investigating antigenicity of pancreatic cancer, particularly in relation to diagnosis and therapy.

Comparative studies on the expression of gastrointestinal-cancer-associated antigen, PA8-15, CA19-9 and the blood-group antigens in non-malignant and malignant human pancreatic tissues

The expression of PA8-15 antigen and the blood-group-related antigens A, B, O, Le(a), Le(b), Le(x), and Le(y), as well as CA19-9, were examined in the normal pancreas and in specimens from benign and malignant pancreatic tissue by the avidin-biotin-immunoperoxidase technique. A correlation was found between the expression of PA8-15, Le(a), and CA19-9 in some cases. However, in the cancer tissues in which neither Le(a) nor CA19-9 could be demonstrated, strong expression of PA8-15 was observed. The reactivity of monoclonal antibody (mAb) PA8-15 with pancreatic cancer tissue was not inhibited by the preincubation of the sections with the mAb anti-Le(a) (CO514) and mAb CA19-9 (CO19-9) indicating that the epitope recognized by PA8-15 is different from that detected by the other two antibodies. Moreover, unlike Le(a) and CA19-9, PA8-15 was also expressed in cancer cells of patients of the Le(a-b-) type. The results suggest that mAb PA8-15 recognizes a sialylated molecule related to Le(a) but different from CA19-9, and seems to be an additional useful marker for pancreatic cancer.

Induction of multifocal pancreatic cancer after inoculation of hamster pancreatic cancer cell line (PC-1) into a defined area of homologous pancreatic tissue

Inoculation of the pancreatic cancer cell line PC-1 into a defined area of the tail of the hamster pancreas led to development of multiple cancerous foci in the body of the pancreas along the main pancreatic duct. Each carcinoma showed identical histological characteristics and was completely separated from the others by regions of normal pancreatic tissue. This observation suggests spread of the cancer from the primary site in discontinuity through the ductal system of the pancreas.

Blood group antigen expression in developing pancreas and in induced pancreatic cancer cells in Syrian hamsters

Expression of blood group-related antigens and the binding pattern of Ulex europaeus-I (UEA-I) in fetal and newborn hamster pancreases was examined immunohistochemically by monoclonal antibodies (MoAbs) against blood group antigens and by peroxidase-conjugated UEA-I. The fetal hamster pancreas was detected histologically at the 12th day of gestation. MoAbs A, B and Le(a) were not immunoreactive with pancreatic cells in any stage of development nor were they after birth. Le(x) was first expressed in the luminal surface of duct cells at the 13th day of gestation, disappeared at the 15th day of gestation, was re-expressed after birth in acinar cells and was absent in the adult pancreas. Le(b) and Le(y) were expressed in acinar cells in late fetal and early newborn stages, but disappeared with maturation and were absent in the adult pancreas. UEA-I binding, however, was demonstrated in both fetal and adult pancreatic tissue. In cancer cells induced by BOP, blood group antigens except for Le(a) and UEA-I binding were found in various reactivity. These findings suggest that in hamsters (i) A and B antigens are tumor-related antigens; (ii) H, Le(b), Le(x) and Le(y) are oncofetal antigens; and (iii) fucosylation is an important event in cell differentiation.

Expression of human tumor-associated antigens in pancreatic cancer induced in Syrian hamsters

Our previous studies have shown that pancreatic cancer induced in Syrian hamsters by N-nitrosobis(2-oxopropyl)amine (BOP) shows remarkable similarities with the human disease in morphologic and biologic characteristics. Moreover, both human and hamster pancreatic cancer share expression of some tumor-associated antigens, such as those with blood group specificities, including A, B, H, Leb, Lex, and Ley. By examining other antigens commonly expressed in human pancreatic cancer, we have found that monoclonal antibodies CO17-1A (recognizing 17-1A antigen), OC 125 (recognizing CA 125 antigen), B72.3 (recognizing TAG-72 and DU-PAN-2 react with induced pancreatic cancer in a pattern similar to that seen in human pancreatic cancer. Remarkably, although the epitopes of the antigens recognized by these three antibodies are different, many tumor cells were reactive with all these antibodies. However, in contrast to the human cancer, none of these antigens were expressed in the normal hamster pancreatic tissue, except for 17-1A. However, all of these antigens were expressed in some hamster tissues showing the same cellular localization as pancreatic cancer cells and corresponded, to a great extent, with findings in human tissue. Expression of these antigens was diminished in vitro (cell culture) but was regained in vivo (homologous transplantation). The results emphasize the usefulness of this experimental model for studying some aspects of tissue antigenicity, particularly as it relates to pancreatic cancer.

Pancreatic ductal adenocarcinomas induced in Syrian hamsters by N-nitrosobis(2-oxopropyl)amine contain a c-Ki-ras oncogene with a point-mutated codon 12

We have used the polymerase chain reaction and dideoxynucleotide sequencing to amplify and sequence exons 1 and 2 of the c-Ki-ras proto-oncogene from the normal Syrian golden hamster. Similar methods were employed to screen for the presence of point mutations in the c-Ki-ras oncogene in primary hamster pancreatic ductal adenocarcinomas (PDC) induced by N-nitrosobis(2-oxopropyl)amine (BOP). A GGT to GAT point mutation was detected in codon 12 of the c-Ki-ras gene in 10 primary hamster PDCs. This same point mutation was present in two nonclonal cell lines, PC-1 and PC-1-0, established from tumors that were produced in hamsters by subcutaneously implanting a preparation of minced BOP-induced PDC. Two clonal cell lines, Cl-3 and Cl-7, were cloned from the PC-1 cell line, and these cell lines also carried the GAT point mutation at codon 12. This point mutation was the same as that detected in greater than 75% of adenocarcinomas from the human exocrine pancreas. Thus, our findings provide further validation for the use of the BOP-induced hamster PDC model as a relevant experimental model for human pancreas cancer: not only did the hamster pancreatic ductal adenocarcinomas closely resemble their human counterpart in histopathological morphology and sequential development, but they also contained the same point mutation in codon 12 of the c-Ki-ras oncogene, as has been reported for human pancreatic adenocarcinomas.