1607197
Enzyme 1990;43:80-88
©1990 S Karger AG, Basel 0013-9432/90/0432-0080S2.75/0
Serum Immunoreactive Pancreatic Phospholipase A2 in Patients with Various Malignant Tumors Yoshio Oka, Michio Ogawa, Yasuki Matsuda, Atsuo Murata, Junichi Nishijima, Keisuke Miyauchi, Kenichi Uda, Tadashi Yasuda, Takesada Mori Second Department of Surgery, Osaka University Medical School, Osaka, Japan
Key Words. Phospholipase A2 • Acute phase reactant • Tumormarker • Carcinoembryonic antigen Abstract. The high incidence (40.6%) of elevated serum pancreatic phospholipase A2 (PLA2) was demonstrated in patients with various malignancies. Serum PLA2 was signifi cantly increased in cancer patients compared with healthy sex- and age-matched blood donors (358.4 ± 168.0 vs. 241.7 ± 69.0 ng/dl; p < 0.01). No correlation was observed between serum PLA2 and carcinoembryonic antigen (CEA) in these patients. Although patients with advanced and distantly metastatic cancer of the liver, gallbladder and pancreas showed higher PLA2 levels in serum than those with early cancer, patients with other cancers showed no correlation between serum PLA2 and clinical stage. A combined assay of PLA2 and CEA increased the sensitivity of detection of cancers to 60.8%.
Pancreatic phospholipase A2 (PLA2; EC 3.1.1.4) is one of the digestive enzymes se creted by pancreatic acinar cells. The impli cation of PLA2 in the pathogenesis of severe acute pancreatitis has been described fre quently [1-6]. In 1983, Eskola et al. [7] and Nishijima et al. [8] independently developed specific immunoassays for human pan creatic PLA2 using a polyclonal antibody against this enyzme. Clinical studies demon
strated the remarkable elevation of serum immunoreactive pancreatic PLA2 in patients with severe acute pancreatitis [9], Previously, pancreatic PLA2 was thought to exist solely in the pancreas. Recently, however, Seilhamer et al. [10] reported that human pancreatic PLA2 was also transcribed in the human lung. Human lung PLA2 cDNA they cloned encoded 15 residues of a signal peptide, 7 residues of an activation peptide and 126 residues of an active pancreatic PLA2. Therefore pancreatic PLA2 in the lung Downloaded by: University of Exeter 144.173.6.94 - 6/7/2020 8:47:54 PM
Introduction
Serum Pancreatic Phospholipase A2 in Malignancy
should be a secretory enzyme like PLA2 in the pancreas. Using an immunoassay, we also demonstrated that pancreatic PLA2 ex isted in various human tissues other than the pancreas [11]. These results suggested that pancreatic PLA2 was also expressed in var ious tissues as a proenzyme. There are many reports showing the ele vation of serum enzymes which existed in various tissues in patients with cancers, such as galactosyltransférase [12, 13], 5'-nucleoti dase [14, 15], creatine kinase [16, 17], sialyltransferase [ 18-20] or y-glutamyltranspeptidase [21]. In the present study, we measured the preoperative serum level and postoperative change of pancreatic PLA2 in patients with various malignant tumors. A correlation with the carcinoembryonic antigen (CEA) level was also examined to evaluate diagnos tic potential of the determination of PLA2.
81
den). Plasma C-reactive protein (CRP) was measured with a Latex/CRP immunodetection kit (Hoechst Ja pan). Plasma pancreatic secretory trypsin inhibitor (PSTI) was measured by a radioimmunoassay kit (Shionogi Co., Osaka, Japan). Plasma haptoglobin (Hp) and ceruloplasmin (Cp) were detected by the nephelometry method (Hoechst Japan). The upper threshold for the reference range of plasma CRP, PSTI, Hp and Cp is 0.2 mg/dl, 17 ng/ml, 300 mg/dl and 37 mg/dl, respectively. Serum CEA was assayed by an enzyme immunoassay kit (Dinabott EIA-II, Tokyo, Japan). The upper threshold for the reference range of CEA in normal subjects is 5.0 ng/ml. Statistical Analysis Statistical evaluation was performed using Stu dent’s t test and linear regression analysis. The differ ence between groups was estimated by analysis of variance, using the nonparametric Scheffé’s F test. Statistical analysis of the data was done with Macin tosh SE microcomputer and the software (StarView 512+) was purchased from Abacus Concepts Inc., Cal if., USA.
Results
Serum Samples Serum samples were obtained from 138 appar ently healthy sex- and age-matched blood donors and 138 preoperative patients with various malignant tu mors (74 males and 64 females). Nine patients had thyroid cancer, 15 breast cancer, 14 esophageal can cer, 44 gastric cancer, 31 colorectal cancer, 14 liver cancer, 7 gallbladder cancer and 4 pancreatic cancer. These patients had normal renal function. The diag nosis of malignant tumor was confirmed by operation or biopsy. The samples were centrifuged at 1,500 gfor 10 min and were stored at -70 °C until assay. Assay Methods Serum PLA2 was determined by PLA2 radioim munoassay kit (S-0932) developed by Shionogi Co., Osaka, Japan, using monoclonal antibody against hu man pancreatic PLA2. Serum amylase activity was measured by a chromogenic method using Phadebas blue starch (Pharmacia Diagnostics, Uppsala, Swe-
Serum PLA2 in Healthy Individuals
Serum PLA2 in the 138 healthy individu als ranged from 98 to 413 ng/dl (mean ± SD: 241.7 ± 69.0 ng/dl.). In the present study, therefore, the normal range of serum PLA2 was set up from 104 to 380 ng/dl. Setting the upper threshold for the reference range (mean +2 SD) at 380 ng/dl, 5 of the control PLA2 contents (3.6%) exceeded 380 ng/dl. Setting the lower limit for the reference range (mean -2SD) at 104 ng/dl, 3 of the controls (2.2%) were below 104 ng/dl. Serum PLA2 in Patients with Various Malignant Tumors
Figure 1 shows serum PLA2 in patients with various malignant tumors, revealing that many patients with cancers of different organs and histologic types had elevated Downloaded by: University of Exeter 144.173.6.94 - 6/7/2020 8:47:54 PM
Material and Methods
Oka/Ogawa/Matsuda/Murata/Nishijima/Miyauchi/Uda/Yasuda/Mori
82
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Fig. 1. Serum PLA 2 in patients with various cancers. A = Early stage; ▲ = advanced, but localized, stage; - advanced stage with distant metastasis; □= stage unclear. * Significant at 95% compared to control.
PLA2 contents. In total, 56 of 138 patients (40.6%) showed increased levels of serum PLA2. The average PLA2 contents in patients with breast, gastric and gallbladder cancers were significantly higher than that of
healthy controls. As shown in figure 1, patients with advanced and distant metastatic cancer of the liver, gallbladder and pancreas showed higher PLA2 levels than those with early cancer. In patients with breast, esophaDownloaded by: University of Exeter 144.173.6.94 - 6/7/2020 8:47:54 PM
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Serum Pancreatic Phospholipase A2 in Malignancy
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Enzyme 1990;43:80-88
©1990 S Karger AG, Basel 0013-9432/90/0432-0080S2.75/0
Serum Immunoreactive Pancreatic Phospholipase A2 in Patients with Various Malignant Tumors Yoshio Oka, Michio Ogawa, Yasuki Matsuda, Atsuo Murata, Junichi Nishijima, Keisuke Miyauchi, Kenichi Uda, Tadashi Yasuda, Takesada Mori Second Department of Surgery, Osaka University Medical School, Osaka, Japan
Key Words. Phospholipase A2 • Acute phase reactant • Tumormarker • Carcinoembryonic antigen Abstract. The high incidence (40.6%) of elevated serum pancreatic phospholipase A2 (PLA2) was demonstrated in patients with various malignancies. Serum PLA2 was signifi cantly increased in cancer patients compared with healthy sex- and age-matched blood donors (358.4 ± 168.0 vs. 241.7 ± 69.0 ng/dl; p < 0.01). No correlation was observed between serum PLA2 and carcinoembryonic antigen (CEA) in these patients. Although patients with advanced and distantly metastatic cancer of the liver, gallbladder and pancreas showed higher PLA2 levels in serum than those with early cancer, patients with other cancers showed no correlation between serum PLA2 and clinical stage. A combined assay of PLA2 and CEA increased the sensitivity of detection of cancers to 60.8%.
Pancreatic phospholipase A2 (PLA2; EC 3.1.1.4) is one of the digestive enzymes se creted by pancreatic acinar cells. The impli cation of PLA2 in the pathogenesis of severe acute pancreatitis has been described fre quently [1-6]. In 1983, Eskola et al. [7] and Nishijima et al. [8] independently developed specific immunoassays for human pan creatic PLA2 using a polyclonal antibody against this enyzme. Clinical studies demon
strated the remarkable elevation of serum immunoreactive pancreatic PLA2 in patients with severe acute pancreatitis [9], Previously, pancreatic PLA2 was thought to exist solely in the pancreas. Recently, however, Seilhamer et al. [10] reported that human pancreatic PLA2 was also transcribed in the human lung. Human lung PLA2 cDNA they cloned encoded 15 residues of a signal peptide, 7 residues of an activation peptide and 126 residues of an active pancreatic PLA2. Therefore pancreatic PLA2 in the lung Downloaded by: University of Exeter 144.173.6.94 - 6/7/2020 8:47:54 PM
Introduction
Serum Pancreatic Phospholipase A2 in Malignancy
should be a secretory enzyme like PLA2 in the pancreas. Using an immunoassay, we also demonstrated that pancreatic PLA2 ex isted in various human tissues other than the pancreas [11]. These results suggested that pancreatic PLA2 was also expressed in var ious tissues as a proenzyme. There are many reports showing the ele vation of serum enzymes which existed in various tissues in patients with cancers, such as galactosyltransférase [12, 13], 5'-nucleoti dase [14, 15], creatine kinase [16, 17], sialyltransferase [ 18-20] or y-glutamyltranspeptidase [21]. In the present study, we measured the preoperative serum level and postoperative change of pancreatic PLA2 in patients with various malignant tumors. A correlation with the carcinoembryonic antigen (CEA) level was also examined to evaluate diagnos tic potential of the determination of PLA2.
81
den). Plasma C-reactive protein (CRP) was measured with a Latex/CRP immunodetection kit (Hoechst Ja pan). Plasma pancreatic secretory trypsin inhibitor (PSTI) was measured by a radioimmunoassay kit (Shionogi Co., Osaka, Japan). Plasma haptoglobin (Hp) and ceruloplasmin (Cp) were detected by the nephelometry method (Hoechst Japan). The upper threshold for the reference range of plasma CRP, PSTI, Hp and Cp is 0.2 mg/dl, 17 ng/ml, 300 mg/dl and 37 mg/dl, respectively. Serum CEA was assayed by an enzyme immunoassay kit (Dinabott EIA-II, Tokyo, Japan). The upper threshold for the reference range of CEA in normal subjects is 5.0 ng/ml. Statistical Analysis Statistical evaluation was performed using Stu dent’s t test and linear regression analysis. The differ ence between groups was estimated by analysis of variance, using the nonparametric Scheffé’s F test. Statistical analysis of the data was done with Macin tosh SE microcomputer and the software (StarView 512+) was purchased from Abacus Concepts Inc., Cal if., USA.
Results
Serum Samples Serum samples were obtained from 138 appar ently healthy sex- and age-matched blood donors and 138 preoperative patients with various malignant tu mors (74 males and 64 females). Nine patients had thyroid cancer, 15 breast cancer, 14 esophageal can cer, 44 gastric cancer, 31 colorectal cancer, 14 liver cancer, 7 gallbladder cancer and 4 pancreatic cancer. These patients had normal renal function. The diag nosis of malignant tumor was confirmed by operation or biopsy. The samples were centrifuged at 1,500 gfor 10 min and were stored at -70 °C until assay. Assay Methods Serum PLA2 was determined by PLA2 radioim munoassay kit (S-0932) developed by Shionogi Co., Osaka, Japan, using monoclonal antibody against hu man pancreatic PLA2. Serum amylase activity was measured by a chromogenic method using Phadebas blue starch (Pharmacia Diagnostics, Uppsala, Swe-
Serum PLA2 in Healthy Individuals
Serum PLA2 in the 138 healthy individu als ranged from 98 to 413 ng/dl (mean ± SD: 241.7 ± 69.0 ng/dl.). In the present study, therefore, the normal range of serum PLA2 was set up from 104 to 380 ng/dl. Setting the upper threshold for the reference range (mean +2 SD) at 380 ng/dl, 5 of the control PLA2 contents (3.6%) exceeded 380 ng/dl. Setting the lower limit for the reference range (mean -2SD) at 104 ng/dl, 3 of the controls (2.2%) were below 104 ng/dl. Serum PLA2 in Patients with Various Malignant Tumors
Figure 1 shows serum PLA2 in patients with various malignant tumors, revealing that many patients with cancers of different organs and histologic types had elevated Downloaded by: University of Exeter 144.173.6.94 - 6/7/2020 8:47:54 PM
Material and Methods
Oka/Ogawa/Matsuda/Murata/Nishijima/Miyauchi/Uda/Yasuda/Mori
82
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Thyroid Breast Esophageal Gastric Colorectal Liver Galloladae- Pax-eatic cancer cancer cancer cancer cancer cancer cancer caxer
Fig. 1. Serum PLA 2 in patients with various cancers. A = Early stage; ▲ = advanced, but localized, stage; - advanced stage with distant metastasis; □= stage unclear. * Significant at 95% compared to control.
PLA2 contents. In total, 56 of 138 patients (40.6%) showed increased levels of serum PLA2. The average PLA2 contents in patients with breast, gastric and gallbladder cancers were significantly higher than that of
healthy controls. As shown in figure 1, patients with advanced and distant metastatic cancer of the liver, gallbladder and pancreas showed higher PLA2 levels than those with early cancer. In patients with breast, esophaDownloaded by: University of Exeter 144.173.6.94 - 6/7/2020 8:47:54 PM
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Serum Pancreatic Phospholipase A2 in Malignancy
83
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