Increased Expression of Sucrase and Intestinal-type Alkaline Phosphatase in Human Gastric Carcinomas with Progression

The activities of sucrase, total alkaline phosphatase (total ALP) and intestinal-type alkaline phosphatase (I-ALP) were assayed in gastric carcinomas and in their surrounding mucosae from 57 patients with advanced cancers, and the localization of sucrase in 203 carcinomas, including 86 early cancers, was examined immunohistochemically using polyclonal anti-sucrase antibody. All three enzymes were active in the 57 carcinomas as well as in their surrounding mucosae, but the levels were fairly low as compared to those in normal jejunum mucosa. A considerable part of the total ALP activity in tumor specimens was assumed to be due to I-ALP itself. Increased sucrase and I-ALP were found with greater depth of invasion by undifferentiated-type carcinomas. The pattern of immunohistochemical localization of sucrase in the 203 carcinomas also clearly indicated increased expression with greater depth of invasion even in differentiated-type carcinomas.     

Alkaline Phosphatase: A marker in prostatic cancer?

From reports in the literature the author concludes that alkaline phosphate is an unspecific marker in prostate cancer correlated to degree of bone involvement, response to treatment and Survival.     

Appearance of Osteonectin-expressing Fibroblastic Cells in Early Rat Stomach Carcinogenesis and Stomach Tumors Induced with N-Methyl-N'-nitro-N-nitrosoguanidine

The present study was designed to define molecular alterations in the initiation stage of rat stomach carcinogenesis. Groups of male Lewis rats, 6 weeks old, were given drinking water with or without N-methyl-N'-nitro-N-nitrosoguanidine (MNNG; 100 mg/liter). Total RNA was isolated from the stomach pyloric mucosa, and fluorescent differential display analysis was performed. A cDNA fragment of 125 bp encoding an extracellular matrix-associated matricellular glycoprotein, osteonectin, was identified after 14 days of MNNG exposure. A severalfold increase in expression was observed after 14 and 27 days of MNNG exposure, as determined by northern blot and RT-PCR. Immunohistochemistry revealed that osteonectin-mAb-stained flbroblastic cells appeared in interstitial tissue of pyloric mucosa. Additionally the gene expression of other extracellular matrix proteins, viz., collagen type III, fibronectin, osteopontin, proteoglycan NG2, laminin γ1 and S-laminin, was also markedly increased, as determined by competitive RT-PCR after 14 days of MNNG exposure. The gene expression of osteonectin and the six other extracellular matrix proteins was elevated in twelve stomach adenocarcinomas and adenomas induced by MNNG in Lewis and WKY rats. Osteonectin-mAb-stained flbroblastic cells were evident in interstitial tissue of stomach tumor. These results suggest that osteonectin-expressing flbroblastic cells appear in the interstitial tissue of pyloric mucosa from the early initiation stage of rat stomach chemical carcinogenesis, and that this phenomenon probably plays a role in cancer development.     

Influence of Gastric pH Modifiers on Development of Intestinal Metaplasia Induced by X-Irradiation in Rats

The influence of gastric pH on intestinal metaplasia was examined in male Crj:CD(SD) rats. At the age of 5 weeks, animals were irradiated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy), and 6 months after irradiation, received either secretin or histamine in silicon tubes for 2 months or had their bilateral submandibular salivary glands removed. The incidences of intestinal metaplasia in the fundus of animals after administration of secretin or histamine, or removal of the salivary glands were reduced, along with the pH values, as compared with values for rats given X-rays alone. In both the pyloric and the fundic gland mucosae, the numbers of alkaline phosphatase (ALP)-positive foci and type B metaplasias (intestinal crypts without Paneth cells) were also significantly decreased (P<0.01). In a second experiment, started six months after irradiation, rats were kept on 1% sodium chloride (NaCl) diet for 6 months. Subsequent removal of salivary glands along with histamine treatment brought about a marked drop in pH and in numbers of ALP-positive foci after three and five days. The present results thus indicated that development and maintenance of intestinal metaplasia can be influenced by a decrease of pH value.     

亚硒酸钠对亚硝基胍诱发大鼠腺胃胃癌的影响

本文报告亚硒酸钠对N-甲基-N’-硝基-N-亚硝基胍(MNNG)诱发大鼠腺胃胃癌的影响。结果表明大鼠饮水每日添加10mg/kg的亚硒酸钠可以抑制MNNG诱发腺胃胃癌、异型增生及前胃病变的发生,并促进癌周纤维组织增生及包裹形成。在大鼠MNNG诱癌实验中,硒作为化学预防剂的每日添加量应低于每只20mg/kg,而饮水浓度不宜超过4mg/L。     

Expression of Human Telomerase RNA Is an Early Event of Stomach Carcinogenesis

Expression of human telomerase RNA (hTR) and telomerase activity in gastric cancer and corresponding non-cancerous mucosa were studied. Telomerase activity was detected in 23 (88%) of 26 carcinoma tissues. Although all tumor specimens and non-cancerous mucosa expressed various levels of hTR, 21 (81%) of 26 cases expressed hTR at a higher level in the tumor than that in the corresponding mucosa. All 8 gastric carcinoma cell lines also expressed hTR at high levels. Nine (35%) of 26 non-cancerous mucosa showed telomerase activity and all of them contained intestinal metaplasia. The incidence of telomerase-positive mucosa in grade 2 intestinal metaplasia was significantly higher than that in grade 0 or grade 1 intestinal metaplasia, whereas hTR overexpression was found in grade 0 or grade 1 intestinal metaplasia as well as grade 2 intestinal metaplasia. The degree of Heticobacter pylori infection increased in parallel with the level of hTR expression and telomerase positivity. These results overall suggest that Helicobacter pylori infection may he a strong trigger for hTR overexpression in intestinal metaplasia, and this may lead to telomerase reactivation.     

Gastric Tumorigenicity of 1,2-Dimethylhydrazine on the Background of Gastric Intestinal Metaplasia Induced by X-Irradiation in CD (SD) Rats

Five-week-old male CD (SD) rats were X-irradiated with a total of 20 Gy in 2 equal fractions with a 3-day interval. After the second irradiation, rats were fed normal diet supplemented with 1% sodium chloride, which is known to increase intestinal metaplasia. 1,2-Dimethylhydrazine (DMH) solution was injected i.m. into the back musculature at a dose of 20 mg/kg body weight weekly for 10 weeks, beginning 20 weeks after the final irradiation. Twelve months after the initial carcinogen treatment, gastric tumors in the glandular stomach were observed in 2 (3 lesions) of 30 animals in the X-irradiated and DMH-treated group fed diet supplemented with 1% sodium chloride. No gastric tumors were observed in the group which excluded X-irradiation from the experimental protocol.     

Detection of Bone-type Alkaline Phosphatase by Monoclonal Antibodies Reacting with Human Osteosarcoma-associated Antigen

The antigen detected by monoclonal antibodies reacting with human osteosarcoma-associated antigen was shown to he a phosphatidyl-inositol (Pl)-glycan-anchored protein, which can be released from the cell surface by PI-specific phospholipase C-treatment. The antigen detected by 2D3 and 2H10 antibodies exhibited alkaline phosphatase activity. Both antibodies strongly reacted with bone-type alkaline phosphatase. However, importantly, immunohistochemical analysis demonstrated that 2D3 and 2H10 did not react with alkaline phosphatase present in kidney or liver. In addition, neither placental nor intestinal alkaline phosphatase was recognized by 2D3 and 2H10 antibodies. These results indicated that two monoclonal antibodies, 2D3 and 2H10, are highly specific for bone-type alkaline phosphatase and can distinguish bone alkaline phosphatase from liver alkaline phosphatase in spite of the fact that liver and bone alkaline phosphatase are encoded by the same gene.     

Lack of Any Positive Effect of Intestinal Metaplasia on Induction of Gastric Tumors in Wistar Rats Treated with N-Methyl-N-nitrosourea in Their Drinking Water

The influence of intestinal metaplasia on gastric cancer induction was examined in five-week-old male Wistan:Crj rats. The animals were first treated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy) and then, starting two months after the irradiation, received 100 ppm N -methyl- N -nitrosourea (MNU) in their drinking water for 15 weeks. Thereafter they were maintained for 37 weeks with or without a dietary 1% sodium chloride (NaCl) supplement. The incidences of gastric adenocarcinomas in the MNU or MNU plus NaCl groups were significantly higher than in animals receiving X-rays plus MNU with or without NaCl. Intestinal metaplasias and the numbers of alkaline phosphatase(ALP)-positive foci were significantly increased in the X-ray irradiation groups but the numbers of ALP-positive foci were not increased with or without 1% NaCl. An inverse relationship between incidences of gastric tumors and intestinal metaplasias was apparent. The present experiment thus showed that the presence of intestinal metaplasia does not exert a positive influence on induction of gastric neoplasia by MNU in the rat.     

Gastric Tumor Induction by 1,2-Dimethylhydrazine in Wistar Rats with Intestinal Metaplasia Caused by X-Irradiation

Five-week-old male Wistar rats were X-irradiated with a total of 20 Gy in 2 equal fractions at a 3-day interval. 1,2-Dimethylhydrazine (DMH) solution was injected i.m. into the back musculature at a dose of 20 mg/kg body weight weekly for 10 weeks, beginning 20 weeks after the final irradiation. Twelve months after the initial carcinogen treatment, tumors in the fundus of the glandular stomach were observed in 5 of 23 animals receiving both X-irradiation and DMH treatment. No tumors of the glandular stomach were observed in the DMH and X-ray alone or nontreatment groups. It is concluded that the presence of intestinal metaplasia may increase sensitivity to the induction of gastric tumors by carcinogens like DMH.     

Cellular Differentiation and Histogenesis of Rat Glandular Stomach Cancers

The gastric and intestinal phenotypic expressions of tumor cells in 18 adenomatous hyperplasias, 33 well-differentiated adenocarcinomas, and 16 undifferentiated adenocarcinomas (4 poorly differentiated adenocarcinomas, 10 signet-ring cell carcinomas and 2 mucinous adenocarcinomas) induced by N-methyl-N'-nitro-N-nitrosoguanidine or 4-nitroquinoline-I-oxide in the rat glandular stomach were studied by histochemical stainings for mucin and immunohistochemical staining for pepsinogen isozyme 1 (Pg 1). By histochemical staining for mucin [by the paradoxical concanavalin A method, the modified method with labeled peanut lectin, the galactose oxidase-Schiff (GOS) reaction, and the sialidase-GOS reaction] and immunohistochemical staining of Pg 1, gastric cancer cells of each histological group could be clearly classified into a gastric type, including mucous neck cell pyloric gland cell, and surface mucous cell subtypes, and an intestinal type, including goblet-cell, and intestinal absorptive cell subtypes. All tumors examined in this work consisted mainly of gastric-type cells but intestinal-type tumor cells were occasionally found among the gastric-type tumor cells. The incidences of intestinal-type cells in adenomatous hyperplasias (11.1%) and small well-differentiated adenocarcinomas (28.6%) were significantly less ( P <0.05) than that in large well-differentiated adenocarcinomas (68.4%). The incidence of intestinal-type cells in small undifferentiated adenocarcinomas (25.0%) was also less than that in large ones (58.3%). The present results suggest the occurrence of change of phenotypic expression of tumor cells from the gastric type to the intestinal type during growth of tumors.     

抑癌蛋白与胃癌细胞增殖和凋亡的关系

为了探讨抑癌蛋白对胃癌细胞增殖和凋亡的影响，以阐明胃癌恶性生长的可能机理，选择８８例手术切除的胃溃疡和胃癌的蜡块标本，将ＢｒｄｕＴＰ掺入到ＤＮＡ的断端，结合抗Ｂｒｄｕ抗体放大信号，再用免疫组化的方法检测组织中的凋亡细胞。同时采用免疫组化方法检测这些组织中的ｐ２１、ｐ５３及ＰＣＮＡ的表达。结果显示，胃癌组织中的细胞增殖水平高而凋亡细胞减少。癌巢中很少有凋亡细胞。胃溃疡组织中凋亡的细胞明显多于胃癌组织。ｐ５３蛋白在胃癌中的检出率为３８．０％。ｐ２１蛋白在胃粘液腺癌及低分化、未分化型腺癌中检出率很低。结果表明，尽管胃癌组织中发现抑癌基因ｐ５３突变蛋白的表达水平增高，但并不能促使胃癌细胞的增殖，却可以增加癌细胞的凋亡。胃粘液腺癌和低分化、未分化型腺癌的抑癌蛋白ｐ２１的表达水平低下可能是该类癌细胞过度增生的原因之一。胃癌细胞凋亡机制障碍和增殖失控是胃癌细胞增生失控的基础     

Sequential Histopathological Changes in vivo after Suicide Gene Therapy of Gastric Cancer Induced by N-Methyl-N'-nitro-N-nitrosoguanidine in Rats

Gastrointestinal cancer is the most important clinical target of gene therapy. Suicide gene therapy, such as with the herpes simplex virus type 1 thymidine kinase ( HSV-TK ) gene, has been shown to exert antitumor efficacy in various cancer models in vitro. We previously reported in situ gene transfer and gene therapy for gastric cancer induced by N -ethyl-. N '-nitro-. N -nitrosoguanidine (ENNG) in dogs. Here, we describe the sequential histopathological changes after suicide gene therapy of N -methyl-. N '-nitro-. N nitrosoguanidine (MNNG)-induced gastric cancer in rats. Gastric tumors were induced by MNNG in 38/73 (52%) of Wistar strain rats. The suicide gene therapy group (14 rats) was subjected to in situ gene transfer with a recombinant adenovirus vector carrying the HSV-TK gene driven by CAG promoter (Ad.CAGHSV-TK) in gastric tumor, followed by the antiviral drug ganciclovir (GCV). To observe the histopathological changes at various tunes after HSV-TK/GCV gene therapy, groups of animals were sacrificed at 3, 8, and 30 days after gene transfer. Apoptosis in the gastric tumors was detected by the TUNEL method to assess the efficacy of HSV-TK/GCV gene therapy, and it was marked in the 8- and 30-day treatment groups compared to the sham operation controls ( P <0.001). Various histopathological changes, degeneration of cancer tissue and fibrosis after necrosis and apoptosis were significantly greater in the 30-day treatment group. The HSV-TK gene was detectable in peripheral blood by PCR until 30 days after gene transfer. These results may be useful in devising a method of suicide gene therapy for humans.     

Promotion by Nialamide of Gastric Carcinogenesis Induced by N-Methyl-N'-nitro-N-nitrosoguanidine in Wistar Rats

The effects of nialamide, a monoamine oxidase inhibitor, on the incidence, number, and histology of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in male Wistar rats. Rats were given subcutaneously 50 mg/kg body weight of nialamide in depot form every other day after 25 weeks of oral treatment with MNNG. Prolonged alternate-day administration of nialamide caused a significant increase in the incidence and number of gastric cancers of the glandular stomach in week 52, However, it did not affect the histology of the cancers. Nialamide also caused a significant increase in tissue norepinephrine concentrations in the gastric wall and in the labeling indices of the gastric mucosae. However, nialamide had no influence on serum gastrin levels in the fasting state and after re-feeding. These findings indicate that nialamide promotes gastric carcinogenesis and that this may be related to its effects in increasing norepinephrine in the gastric wall and stimulating proliferation of gastric epithelial cells.     

骨显像联合碱性磷酸酶诊断159例前列腺癌骨转移

[目的]探讨骨型碱性磷酸酶(B-AKP)对前列腺癌骨转移的诊断价值及与骨显像的关系,弥补骨显像诊断骨转移的不足.[方法]对159例前列腺癌进行骨显像,并测定B-AKP.根据骨显像将病人分成骨转移组与无骨转移组,B-AKP在两组间的比较采用t检验.按病灶多少将骨显像分0～3级,各级间B-AKP比较采用t检验.B-AKP值与骨病灶数目间进行相关分析.[结果]①159例病人中,骨显像诊断骨转移114例,10例假阳性,漏诊3例,诊断灵敏度97.2%(104/107),假阳性率19.2%(10/52).②B-AKP诊断骨转移的灵敏度为83.2%,特异性50.0%.③B-AKP在骨转移组为(26.3±15.6)μg/L,无骨转移组为(16.9±8.7)μg/L,两组差异有显著性(t=4.045,P＜0.001).单发热区者7例,B-AKP值为(19.7±4.1)μg/L,4例单发冷区病人为(13.2±3.2)μg/L,两者差异有显著性(t=2.711,P＜0.05).④B-AKP值与骨转移病灶数目间呈正相关(相关系数r=-0.751,P＜0.01).[结论]B-AKP与骨显像有很好的一致性.诊断前列腺癌骨转移,应首选骨显像.     

实验性胃粘膜肠上皮化生组织发生的研究

本文首次报道应用小剂量ＭＮＮＧ和雷尼替丁诱发了Ｗｉｓｔａｒ鼠实验性胃粘膜肠化生，应用该模型对肠化的发生、发展过程进行动态观察。肠化最早出现于实验第９周，在第１２周以前，化生只见于腺颈部；第１４、１６周的标本上可见肠化生自腺颈部向上或向下延伸；第１８、２０周及以后的标本上，可见到胃粘膜不同部位的肠化生，尤以胃粘膜下１／３最为显著。结果说明肠化生起源于胃粘膜腺颈部增殖细胞区，之后可向粘膜表面或腺底部发展，似乎以后者为主。     

Synergistic Effect of Radiation on Colon Carcinogenesis Induced by Methylazoxymethanol Acetate in ACI/N Rats

The effect on colon and liver carcinogenicity in rats of a single X-irradiation exposure given either before or after methylazoxymethanol (MAM) acetate was studied in ACI/N rats of both sexes. A single dose of X-irradiation (3 Gy) was administered either 3 months before or after three weekly s.c. injections of MAM acetate (25 mg/kg body weight). At 365 days after the start, the incidence and multiplicity of MAM acetate-induced intestinal tumors were enhanced by X-irradiation either prior to or after the MAM acetate treatment. In addition, X-irradiation before MAM acetate increased the incidence of hepatocellular foci in either sex. In females, X-irradiation either before or after MAM acetate exposure decreased intestinal tumorigenesis. These findings suggest an apparent synergism of these agents in intestinal carcinogenesis of male rats.     

Rare Occurrence of ras and p53 Gene Mutations in Mouse Stomach Tumors Induced by N–Methyl–N–nitrosourea

The incidence of point mutations of H–, K– and N– ras and p53 oncogenes in male BALB/c mouse stomach tumors induced with A^r–methyl–A^r–nitrosourea (MNU) was examined by direct sequencing and PCR single–strand conformation polymorphism (PCR–SSCP). A mutation of GGT to AGT at K–ras codon 12 was found by SSCP in one adenocarcinoma from a total of 19 specimens including 5 adenocarcinomas, 9 adenomatous hypcrplastic regions, 1 squamous cell carcinoma and 4 normal–like stomach regions from 4 mice. No mutations were detected by direct sequencing of H–, K– and N–ras oncogenes at exons 1 (codons 12 and 13) and 2 (codon 61) in a total of 26 specimens comprising 10 adenocarcinomas, 10 adenomatons hyperplastic regions, 2 squamous cell carcinomas and 4 normal–like stomach regions from 6 mice. No mutations were detected by direct sequencing ofp53 oncogene at exons 5, 6, 7 and 8 in a total of 30 specimens including 13 adenocarcinomas, 8 adenomatous hyperplastic regions, 2 squamous cell carcinomas, 1 papilloma and 6 normal–like stomach regions from 7 mice. These results suggest that ras and p53 oncogenes do not play a role in mouse stomach carcinogenesis induced by MNU.