Metachronous squamous cell carcinoma of the esophagus arising after endoscopic mucosal resection

BACKGROUND

Endoscopic mucosal resection (EMR) is being used increasingly to treat early stage esophageal carcinoma. However, the preserved esophageal mucosa may be the source of new lesions. The aims of this study were to analyze the frequency of metachronous esophageal carcinoma after EMR and to determine whether minute iodine unstained areas often associated with squamous cell carcinoma develop into carcinoma.

METHODS

Eighty-two patients with esophageal squamous cell carcinoma who underwent EMR were studied. Based on the iodine staining pattern at initial EMR, they were divided into those with uniform (group U) and scattered (group S) types of background mucosa. Patients were followed by endoscopy with iodine staining (group U: median 39 months, range 12 to 71 months; group S: median 38 months, range 14 to 68 months).

RESULTS

In total, 12 (14.6%) of 82 patients were found to have metachronous esophageal carcinoma during follow-up, including 6 (37.5%) of 16 patients in group S. The cumulative proportion of metachronous carcinoma-free subjects was significantly lower in group S than group U (p = 0.0048).

CONCLUSIONS

Primary esophageal carcinoma develops frequently in patients who have undergone EMR for esophageal squamous carcinoma. The high frequency of metachronous carcinoma may be attributed to field carcinogenesis. Careful long-term endoscopic observation is required for patients who undergo EMR for esophageal carcinoma, especially those with scattered-type iodine staining of the background mucosa.

Absence of microsatellite instability and germline mutations of E-cadherin, APC and p53 genes in Japanese familial gastric cancer

To evaluate the genetic factors of familial predisposition to gastric cancer, genetic alterations in the surgically resected stomach samples from gastric-cancer-prone families were investigated. Familial gastric cancer (FGC) was defined as gastric cancer occurring in a family with 3 or more gastric cancer patients over at least two successive generations. We examined replication error (RER) of six microsatellite markers and screened mutations of the 10-(A) repeat sequence in the transforming growth factor-beta receptor type II (TGF-betaRII) gene in individuals from seven unrelated FGC families. Three cases showed RER at one of the six (CA)n microsatellite markers but the other 4 cases showed no RER at any of these loci. No mutation was found in the 10-(A) repeat of the TGF-betaRII gene. Additionally, no germline mutation was found by polymerase chain reaction-single strand conformation polymorphism in exons 1-16 of E-cadherin, exons 5-8 of p53 and in the mutation cluster region of APC. These results indicate that disorders in the DNA mismatch repair system, E-cadherin, p53 and APC may be infrequently involved in the carcinogenesis of Japanese FGC.

Kinetics of testosterone 6beta-hydroxylation in the reconstituted system with similar ratios of purified CYP3A4, NADPH-cytochrome p450 oxidoreductase and cytochrome B5 to human liver microsomes

Kinetics of testosterone 6beta-hydroxylation were determined using a reconstituted system that consisted of CYP3A4, cytochrome b5 and NADPH-cytochrome P450 oxidoreductase (OR) with similar ratios as those seen in human liver microsomes and compared with those determined using human liver microsomes. Two reconstituted systems were constructed in accordance with two human liver microsomal samples that showed extremely high and low ratios of OR/CYP3A4. The Km values of testosterone 6beta-hydroxylation obtained from the reconstituted systems with high and low OR/CYP3A4 ratios were 29.3 and 35.2 microM, respectively, which were similar to that of the corresponding human liver microsomal samples (23.2 and 40.0 microM, respectively). However, Vmax values obtained from the reconstituted systems (3.7 and 0.8 pmol/min/pmol CYP3A4) were much lower than those from the human liver microsomes (44.2 and 31.1 pmol/min/pmol CYP3A4). The results suggest that the interaction between substrate and CYP3A4 in the reconstituted systems appear to be similar to human liver microsomes but that the velocity of the substrate metabolism in the reconstituted systems is different from that in human liver microsomes. In conclusion, our reconstituted systems could be used for the determination of affinity but not for the determination of the maximum velocity of substrate metabolism. Further studies on the protein-protein interactions between CYP3A4, OR, cytochrome b5 and/or a specific lipid environment are required to establish a reconstituted system showing similar kinetic properties to those of human liver microsomes.

Effects of insulin and glucose loading on FDG uptake in experimental malignant tumours and inflammatory lesions

Fluorine-18 2-deoxy-2-fluoro-D-glucose (FDG) accumulation in tumours has been well investigated, but much less is known regarding FDG accumulation in inflammatory lesions. In this study, we determined the effects of hypo- and hyperglycaemia on FDG uptake in inflammatory lesions of infectious and non-infectious origin and compared them with those in malignant tumours in rats, to provide a biological basis for differentiating malignant lesions from benign lesions by means of FDG-PET. Rats were inoculated with a suspension of allogenic hepatoma cells (KDH-8) or Staphylococcus aureus, or with turpentine oil into the left calf muscle. Two weeks after KDH-8 inoculation and 1 week after S. aureus and turpentine oil inoculations, the rats were divided into three subgroups: insulin-loaded (2 U/kg body weight, i.p.), glucose-loaded (1.2 g/kg body weight, p.o.) and control groups. Radioactivity in tissues was determined 1 h after i.v. injection of FDG. Intraperitoneal injection of insulin and oral administration of glucose induced hypoglycaemia and hyperglycaemia, respectively. In the control animals, tumours showed a level of FDG uptake which was 2.2 and 3.0 times higher than the levels in the inflammatory lesions induced by S. aureus and turpentine oil, respectively (P<0.0001). There was no significant difference in the level of FDG uptake between the two inflammatory lesions of infectious and non-infectious origin. Insulin loading significantly decreased the level of FDG uptake in tumours and in both types of inflammatory lesion to approximately one-half of the control values (P=0.001 in the tumour group and P<0.0001 in the two inflammatory lesion groups). In the glucose-loaded group, the level of FDG uptake in both types of inflammatory lesion decreased significantly to 50%-61% of the control value (P=0.0002 in the S. aureus group and P<0.0001 in the turpetine group), while the tumour uptake did not decrease significantly (86% of the control value) (P=NS). It is concluded that FDG uptake in both types of inflammatory lesion was significantly impaired in rats with hyperglycaemia induced by glucose loading, while tumour uptake of FDG was not significantly affected. These results indicate that glucose loading has greater effects on FDG uptake in inflammatory lesions than in tumours, providing a biological basis for differentiation of malignant lesions from benign lesions by FDG-PET in a clinical setting.

Synergistic effects of highly unsaturated fatty acid-containing phosphatidyl-ethanolamine on differentiation of human leukemia HL-60 cells by dibutyryl cyclic adenosine monophosphate

Highly unsaturated fatty acid-containing phospholipid (HUFA-PL) has many nutritional and medical applications. We investigated the effect of HUFA-PL on differentiation of human leukemia HL-60 cells induced by dibutyryl cyclic adenosine monophosphate (dbcAMP). HUFA-containing phosphatidylethanolamine (HUFA-PE), such as salmon testis PE, significantly enhanced dbcAMP-induced cell differentiation. A combined treatment of 200 mM dbcAMP with 50 mM HUFA-PE increased the nitroblue tetrazolium (NBT)-reducing activity, which is an indicator of differentiation, to a level comparable to that in the case of 500 mM dbcAMP treatment. In contrast, HUFA-lyso PE (a monoacyl form) did not exert an enhancing effect on dbcAMP-induced differentiation. The enhancing effect of HUFA-PE was suppressed by a protein kinase C inhibitor, staurosporine, while a protein kinase A inhibitor, H-8, did not suppress the enhancing effect. These findings suggest that HUFA-PE might enhance dbcAMP-induced differentiation through modulation of the protein kinase C signaling pathway in HL-60 cells.

Spontaneous loss-of-function mutations of the 8-oxoguanine DNA glycosylase gene in mice and exploration of the possible implication of the gene in senescence

8-Oxoguanine is one of the major premutagenic oxidative base legions in vivo and is suspected to play a crucial role in various pathophysiological processes, such as cancer and aging. Mammalian 8-oxoguanine DNA glycosylase (OGG1) is thought to play a major role in the removal of 8-oxoguanine adducts in vivo. We have identified several inbred mouse strains with a spontaneous mutation, OGG1-R336H or double mutations, OGG1-R304W/R336H. R304W mutation caused a complete loss of OGG1 activity, while the R336H mutation led to disruption of nuclear localization of the enzyme although the activity remained normal. Among the double mutants was SAMP1, which exhibits accelerated senescence and short lifespan. We assessed the possible implication of the mutant OGG1 and 8-oxoguanine in aging utilizing SAMP1 mice. SAMP1 retained 1.5- to 1.9-fold increase in 8-oxoguanine level of hepatic nuclear DNA as compared with normal mice, until at least 12 months of age. A genetic association study, however, indicated that the mutant Ogg1 gene per se is not responsible for the accelerated senescence and short lifespan of SAMP1. Mutant OGG1 may be associated with pathologic conditions in other mouse strains.

Purification, molecular cloning, and functional expression of dog liver microsomal acyl-CoA hydrolase: a member of the carboxylesterase multigene family

To clarify the reason for the high acyl-CoA hydrolase (ACH) activity found in dog liver microsomes, the ACH was purified to homogeneity using column chromatography. The purified enzyme, named ACH D1, exhibited a subunit molecular weight of 60 KDa. The amino terminal amino acid sequence showed a striking homology with rat liver carboxylesterase (CES) isozymes. ACH D1 possessed hydrolytic activities toward esters containing xenobiotics in addition to acyl-CoA thioesters, and these activities were inhibited by a specific inhibitor of CES or by CES RH1 antibodies. These findings suggest that this protein is a member of the CES multigene family. Since ACH D1 appears to be a protein belonging to the CES family, we cloned the cDNA from a dog liver lambdagt10 library with a CES-specific probe. The clone obtained, designated CES D1, possessed several motifs characterizing CES isozymes, and the deduced amino acid sequences were 100% identical with those of ACH D1 in the first 18 amino acid residues. When it was expressed in V79 cells, it showed high catalytic activities toward acyl-CoA thioesters. In addition, the characteristics of the expressed protein were identical with those of ACH D1 in many cases, suggesting that CES D1 encodes liver microsomal ACH D1.

Ultrastructural and permeability features of microvessels in the hippocampus, cerebellum and pons of senescence-accelerated mice (SAM)

We previously reported that the accumulation of blood-borne radiolabelled serum albumin in brain parenchyma increased with aging, especially in senescence-accelerated mice (SAMP8), which showed age-related deficits in learning and memory. In this study, in order to examine morphological events related to the age-related increase of the brain accumulation of serum albumin, the transvascular passage of blood-borne horseradish peroxidase (HRP) and ultrastructural features of microvessels were examined in the hippocampus, cerebellum and pons of SAMP8 and SAMR1 (control) mice. Ultrastructural examination of the hippocampus showed that the staining for HRP was occasionally spreading throughout the parajunctional cytoplasm of the endothelial cell of aged SAMP8 mice, but not in young SAMP8 mice nor in SAMR1 mice. The number of vessels showing the staining reaction for HRP in the parajunctional cytoplasm of the endothelial cells in aged SAMP8 mice increased significantly compared with that in the others. Electron microscopic morphometry showed that there were no significant differences among the number of HRP-positive vesicles per unit area of the endothelial cell cytoplasm in young and old mice of both strains. The staining reaction for HRP was not seen in the basal lamina of microvessels and the perivascular neuropil in all mice examined. Perivascular lipofuscin-like granules and collagen deposits, swelling of astroglial perivascular endfeet and perivascular cells containing foamy, lipid-like droplets were frequently found in several brain regions of aged SAMP8 mice. The perivascular cells with a few lipid-like droplets and more electron-homogeneous lysosomes were occasionally seen in SAMR1 and young SAMP8, while the other findings were scarcely observed in SAMR1 and young SAMP8 mice. These findings suggest that the blood-brain barrier to HRP was preserved in microvessels in three brain regions of SAM mice but the blood microvessels showed some age-related ultrastructural alterations in SAMP8 brains. Uncontrolled passage of HRP through the parajunctional cytoplasm of the endothelial cells may partly contribute to the age-related increase of accumulation of serum albumin in SAMP8 brains.

Ultrastructural and permeability features of microvessels in the periventricular area of senescence-accelerated mice (SAM)

Brain transfer of intravenously injected horseradish peroxidase (HRP) and the ultrastructural features of the vessels were examined in periventricular areas in senescence-accelerated mice (SAMP8), which show age-related deficits in learning and memory, and senescence-accelerated resistant mice (SAMR1), which do not show age-related deficits. In all mice examined with light microscopy, staining reaction for HRP was seen in the periventricular area adjacent to the medial side of the lateral ventricle. Electron microscopic examination in the periventricular area of young and old mice of both strains showed that the staining reaction for HRP appeared in the vesicular profiles of the endothelial cytoplasm, the cytoplasm of the perivascular cells, the basal lamina, and the adjoining extracellular spaces of the white matter, suggesting an incomplete blood-brain barrier (BBB) in the periventricular white matter. In addition, irregularly thickened endothelial cell cytoplasm, membranous inclusions within the basal lamina, and electron-dense endothelial cell cytoplasm were occasionally seen in aged SAMP8 mice. These findings were not observed in 3-month-old SAMP8 mice and 3- and 13-month-old SAMR1 mice. Perivascular collagen deposits were also frequently seen in aged SAMP8 mice. These findings indicate that the endothelial cells and pericytes in the periventricular white matter in aged SAMP8 mice have an ultrastructure with damaged BBB function. Intravascular substances can easily penetrate the periventricular white matter and the BBB of the vessels in the area can be deteriorated with aging in SAMP8 mice.

Deterioration in learning and memory of fear conditioning in response to context in aged SAMP8 mice 1 1Abbreviations: SAM, senescence-accelerated mouse; SAMP, senescence-accelerated mouse prone; SAMR, senescence-accelerated mouse resistant; GABA, gamma-aminobutyric acid; MGRF, magnocelluar reticular formation; RSA, hippocampal rhythmic slow activity; CS, conditioned stimulus

This study examined age-dependent deficits in the learning and memory of fear conditioning, using a newly developed senescence-accelerated mouse (SAMP8) model of age-related brain dysfunction and its genetically related inbred strain (SAMR1). The mice were classically conditioned to tone by giving aversive foot shocks in a distinct experimental box (context). After conditioning, fear in response to the original context without the tone and to the tone in a different context were tested with no shocks. Freezing behavior was used as a reliable index of fear. At 4 and 8 months, contextual fear was weaker in the accelerated senescence-prone SAMP8 mice than in the accelerated senescence-resistant SAMR1 mice. However, at 1 and 2 months, both SAMP8 and SAMR1 mice showed significant contextual fear to equivalent levels. Aging did not affect the fear response to tone. These results indicate that SAMP8 mice have age-related learning and memory deficits in their fear response evoked by contextual but not explicit tone stimuli. Age-related hippocampal dysfunction is suggested to be the cause of these age-related deficits in contextual fear conditioning in SAMP8 mice.

High-performance liquid chromatographic analysis of the sulfation of 4-hydroxypropranolol enantiomers by monkey liver cytosol

We developed a new high-performance liquid chromatographic method using an ODS column and a chiral column for the assay of racemic 4-OH-PL sulfate and enantiomeric 4-OH-PL sulfates, respectively. The method was successfully applied to measure phenolsulfotransferase (PST) activities for 4-OH-PL in cytosolic fractions from livers of Japanese monkeys (Macaca fuscata) and for comparison with its activity of cytosolic fractions from rat, rabbit, dog, and human livers and Hep G2 cells. The activity was ranked as Hep G2 cells > monkeys = humans = dogs = rats > rabbits. To evaluate the Japanese monkey as a nonhuman animal model in drug metabolism studies, we further characterized sulfation of 4-OH-PL as a further metabolic pathway in monkey livers to compare that with human livers. Inhibition studies in which cytosolic fractions were preincubated at 43 degrees C or 2,6-dichloro-4-nitrophenol (DCNP) used as a PST inhibitor indicated that two kinds of PSTs, thermolabile, low-Km and DCNP-resistant PST and thermostable, high-Km and DCNP-sensitive PST were involved in 4-OH-PL sulfation by monkey liver cytosol, which is very similar to the reported profile of 4-OH-PL sulfation by human liver cytosol. Sulfation kinetics in a low concentration range of 4-OH-PL enantiomers demonstrated that apparent Km values were similar between human and monkey liver cytosolic fractions, but the Vmax values were different, so that intrinsic clearance values (Vmax/Km, Clint) were higher in monkeys than in humans. Furthermore, enantiomer selectivity of [R(+)-4-OH-PL > S(-)-4-OH-PL] was observed in the Vmax and CLint values of monkey liver cytosol. These results indicate that the profile of sulfation of 4-OH-PL by liver cytosolic fractions is similar in humans and Japanese monkeys.

Troglitazone, a ligand for peroxisome proliferator-activated receptor gamma, inhibits chemically-induced aberrant crypt foci in rats

The biological roles of peroxisome proliferator-activated receptors (PPARs) in various diseases, including inflammation and cancer, have been highlighted recently. Although PPARgamma ligand is suspected to play an important role in carcinogenesis, its effects on colon tumorigenesis remain undetermined. The present time-course study was conducted to investigate possible modifying effects of a PPARgamma ligand, troglitazone, on the development and growth of aberrant crypt foci (ACF), putative precursor lesions for colon carcinoma, induced by azoxymethane (AOM) or dextran sodium sulfate (DSS) in male F344 rats. Oral troglitazone (10 or 30 mg / kg body weight (b.w.)) significantly reduced AOM (two weekly subcutaneous injections, 20 mg / kg b.w.)-induced ACF. Treatment with troglitazone increased apoptosis and decreased polyamine content and ornithine decarboxylase (ODC) activity in the colonic mucosa of rats treated with AOM. Gastric gavage of troglitazone also inhibited colitis and ACF induced by DSS (1% in drinking water), in conjunction with increased apoptosis and reduced colonic mucosal polyamine level and ODC activity. Our results suggest that troglitazone, a synthetic PPARgamma ligand, can inhibit the early stage of colon tumorigenesis with or without colitis.

Transmission of mouse senile amyloidosis

SUMMARY

In mouse senile amyloidosis, apolipoprotein A-II polymerizes into amyloid fibrils (AApoAII) and deposits systemically. Peripheral injection of AApoAII fibrils into young mice induces systemic amyloidosis (Higuchi et al, 1998). We isolated AApoAII amyloid fibrils from the livers of old R1.P1-Apoa2(c) mice and injected them with feeding needles into the stomachs of young R1.P1-Apoa2(c) mice for 5 consecutive days. After 2 months, all mice had AApoAII deposits in the lamina propria of the small intestine. Amyloid deposition extended to the tongue, stomach, heart, and liver at 3 and 4 months after feeding. AApoAII suspended in drinking water also induced amyloidosis. Amyloid deposition was induced in young mice reared in the same cage for 3 months with old mice who had severe amyloidosis. Detection of AApoAII in feces of old mice and induction of amyloidosis by the injection of an amyloid fraction of feces suggested the propagation of amyloidosis by eating feces. Here, we substantiate the transmissibility of AApoAII amyloidosis and present a possible pathogenesis of amyloidosis, ie, oral transmission of amyloid fibril conformation, where we assert that exogenous amyloid fibrils act as templates and change the conformation of endogenous amyloid protein to polymerize into amyloid fibrils.

Expression of the gamma(2) chain of laminin-5 at the invasive front is associated with recurrence and poor prognosis in human esophageal squamous cell carcinoma

PURPOSE

Preferential expression of the gamma(2) chain of laminin-5 in invading carcinoma cells has been implicated in tumor invasion. The aim of this study was to clarify the clinicopathological and prognostic significance of laminin gamma(2) chain expression in esophageal squamous cell carcinoma (SCC).

EXPERIMENTAL DESIGN

We analyzed the association between immunohistochemically detected laminin gamma(2) chain expression in esophageal SCC and clinicopathological characteristics, and we investigated whether laminin gamma(2) chain is a predictor of recurrence and/or survival.

RESULTS

The cytoplasm of carcinoma cells was stained for laminin gamma(2) at levels much stronger than those in normal esophageal basement membrane. The immunoreactivities at the invasive front were often more intense than those at the superficial layer. Sections with immunostaining signals in >30% of carcinoma cells at the invasive front, which were observed in 44 of 100 cases, were judged to be positive for laminin gamma(2) chain. Laminin gamma(2) chain positivity was significantly correlated with depth of invasion, lymph node metastasis, distant metastasis, advanced pTNM stage, recurrence, and recurrence within the first postoperative year. Patients with laminin gamma(2) chain-positive carcinoma had a significantly shorter disease-free and overall survival time than did those with laminin gamma(2) chain-negative carcinoma. Laminin gamma(2) chain retained its significant predictive value for disease-free and overall survival in multivariate analysis that included conventional clinicopathological factors.

CONCLUSIONS

Our results suggest that the laminin gamma(2) chain plays a key role in the progression of esophageal carcinoma and that its detection is useful for the prediction of recurrence and poor prognosis.

Association of trypsin expression with recurrence and poor prognosis in human esophageal squamous cell carcinoma

BACKGROUND

Overexpression of the matrix serine proteinase (MSP) trypsin has been implicated in tumor growth, invasion, and metastasis. The objective of this study was to clarify the clinicopathologic and prognostic significance of trypsin expression in esophageal squamous cell carcinomas (SCC).

METHODS

Production of trypsin in tissue extracts was analyzed by immunoblotting and gelatin zymography. The authors analyzed the association between immunohistochemically detected trypsin expression in esophageal SCC and clinicopathologic characteristics, and they investigated whether trypsin is a predictor of recurrence and/or survival.

RESULTS

Overproduction and activation of trypsin was observed in 6 of 10 tumor extracts. The trypsin immunoreactivities at the invasive front were more intense than those at the superficial layer. Sections with immunostaining signals in greater than 30% of carcinoma cells at the invasive front, which were observed in 52 (52%) cases, were judged to be positive for trypsin. Trypsin positivity was significantly correlated with the depth of invasion (P < 0.0001), lymph node metastasis (P = 0.0048), advanced pTNM classification (P = 0.0006), recurrence (P = 0.0003), and recurrence within the first postoperative year (P = 0.0005). Patients with trypsin positive carcinoma had significantly shorter disease free and overall survival times than did those with trypsin negative carcinoma (P < 0.0001 and P < 0.0001, respectively). Trypsin retained its significant predictive value for disease free and overall survival in multivariate analysis that included conventional clinicopathologic factors (P = 0.0029 and P = 0.0006, respectively). Patients with concomitant overexpression of trypsin and matrilysin at the invasive front, in which they often were colocalized, had the worst prognosis.

CONCLUSIONS

The authors' results suggest that trypsin plays a key role in the progression of esophageal carcinoma. Detection of trypsin expression as well as matrilysin is useful for the prediction of recurrence and poor prognosis.

Ligands for peroxisome proliferator-activated receptors alpha and gamma inhibit chemically induced colitis and formation of aberrant crypt foci in rats

The biological role of the peroxisome proliferator-activated receptors (PPARs) in various diseases, including inflammation and cancer, has been highlighted recently. Although PPARgamma ligands have been found to inhibit mammary carcinogenesis in rodents, the effects on colon tumorigenesis are controversial. In the present study, three different experiments were conducted to investigate the modifying effects of PPARs ligands (PPARalpha and PPARgamma) on colitis and an early phase of colitis-related colon carcinogenesis in male F344 rats. In the first experiment, gastric gavage of troglitazone (PPARgamma ligand, 10 or 100 mg/kg body weight) or bezafibrate (PPARalpha ligand, 10 or 100 mg/kg body weight) inhibited colitis induced by dextran sodium sulfate (DSS) and lowered trefoil factor-2 content in colonic mucosa. In the second experiment, dietary administration (0.01 or 0.05% in diet) of troglitazone and bezafibrate for 4 weeks significantly reduced azoxymethane (AOM, two weekly s.c. injections, 20 mg/kg body weight)-induced formation of aberrant crypts foci, which are precursor lesions for colon carcinoma. In the third experiment, dietary administration (0.01% in diet for 6 weeks) of pioglitazone (PPARgamma ligand), troglitazone, and bezafibrate effectively suppressed DSS/AOM-induced ACF. Administration of both ligands significantly reduced cell proliferation activity in colonic mucosa exposed to DSS and AOM. Our results suggest that synthetic PPARs ligands (PPARalpha and PPARgamma) can inhibit the early stages of colon tumorigenesis with or without colitis.

Activated leukocyte cell adhesion molecule (ALCAM) and annexin II are involved in the metastatic progression of tumor cells after chemotherapy with Adriamycin

Metastasis frequently occurs during and/or after chemotherapy resulting in failure. This suggests that inadequate chemotherapy promotes the emergence of more malignant tumor cells with metastatic potential. However, it is not determined how chemotherapy could promote the metastatic progression of tumor cells. In this study, we isolated highly metastatic clones from the tumors treated with ADR using an in vivo experimental model, in which non-metastatic tumor cells were inoculated s.c. in mice, treated with or without Adriamycin and then culture lines were re-established from the tumors. Then we isolated cDNAs for activated leukocyte cell adhesion molecule (ALCAM), osteopontin, and annexin II as candidates for metastasis-promoting genes with the use of a PCR-based subtraction method. Further we examined the metastatic potential of transfectants over-expressing ALCAM, osteopontin, or annexin II and combinations of them. Metastasis to the lung was observed in the mice where transfectants over-expressing ALCAM plus annexin II had been inoculated via tail vein. These results suggest that the over-expression of ALCAM and annexin II play a role in the metastatic progression after chemotherapy with ADR.

Mutational analysis of the beta-catenin gene in gastric carcinomas

Previous studies reported that mutation of the adenomatous polyposis coli (APC) gene was not observed in the majority of gastric cancers. To evaluate the role of the APC/beta-catenin/Tcf pathway, we analyzed mutations in the beta-catenin gene and the accumulation of beta-catenin protein in gastric carcinomas. An interstitial deletion spanning exon 3 of the beta-catenin gene was observed in 1 of 13 gastric cancer cell lines. No missense mutation was found in these 13 cell lines. Nuclear and/or cytoplasmic localization of beta-catenin was observed in 16 of 70 primary gastric carcinomas by immunohistochemistry, while we found no mutations in exon 3 in 35 carcinoma tissues available for PCR amplification. Our findings suggest that somatic mutations of the beta-catenin gene are rare in human gastric carcinomas and that accumulation of normal beta-catenin protein in a subset of gastric cancers may be due to other mechanisms of its activation.

Prevalence of Barrett's esophagus and expression of mucin antigens detected by a panel of monoclonal antibodies in Barrett's esophagus and esophageal adenocarcinoma in Japan

Barrett's esophagus (BE) is an acquired disorder associated with a high incidence of adenocarcinoma of the lower esophagus. Moreover, it has been reported that short-segment BE may be associated with adenocarcinoma of the esophagogastric junction. The objective of this study was to define the prevalence of BE and the mucin profile in BE, including the short-segment type, and to compare the mucin profile in BE with the profiles of Barrett's adenocarcinoma and distal esophageal adenocarcinoma among Japanese. In total, 650 adult subjects underwent endoscopic examination for evaluation of BE. Although the prevalence of traditional (long segment) BE was 0.62%, the overall prevalence of BE including short-segment type was 15.7%. In Barrett's epithelium, the short-segment type predominantly had gastric type mucin, while the middle- and long-segment types possessed intestinal mucin, especially colonic type mucin (sulfo-Lewis(a)), with high frequency. In Barrett's epithelium with adenocarcinoma, all Barrett's epithelium adjacent to carcinomas showed a predominance of immunoreactivity to sulfo-Lewis(a). In Barrett's adenocarcinomas, colonic type mucin was detected in 100% by monoclonal antibody (MoAb) 91.9H. Small-intestinal mucin and gastric mucin were stained in 50% and 12.5% of the subjects, respectively. Colonic type mucin was also detected with high frequency (80%) in distal esophageal adenocarcinomas without Barrett's epithelium. These data suggest that the epitope, not of small-intestinal type or gastric type mucin, but of colonic type mucin (sulfo-Lewis(a)), may be associated with, at least in part, the malignant phenotype of BE.

Increased oxidative DNA damage in mammary tumor cells by continuous epidermal growth factor stimulation

BACKGROUND

Growth factors can enhance the malignant potential of tumor cells. To examine the relationship between growth factors and tumor progression, we previously established a weakly malignant cell line, ER-1. We found that a 24-hour exposure of ER-1 cells to epidermal growth factor (EGF) induced malignant properties (tumor progression) that were reversible but that, after a 1-month exposure, these changes were irreversible. In this study, we investigated the irreversible changes induced in ER-1 cells by a 1-month exposure to EGF and the possible involvement of oxidative stress.

METHODS

ER-1 cells were treated with EGF (100 ng/mL) for 1 month in the presence or absence of an antioxidant, N-acetylcysteine or selenium, and compared with untreated control ER-1 cells. We assessed tumor progression by measuring intracellular peroxide levels, 8-hydroxydeoxyguanosine (a marker for oxidative DNA damage) levels, in vitro invasiveness, and in vivo tumorigenicity and metastatic ability. All statistical tests are two-sided.

RESULTS

After ER-1 cells were treated for 1 month with EGF, levels of intracellular peroxide and 8-hydroxyguanosine in the DNA of treated cells were higher than those in the DNA of control cells, and treated ER-1 cells were more tumorigenic and metastatic in vivo and more invasive in vitro than untreated control cells (all P<.001). Levels of 8-hydroxyguanosine in DNA increased as the length of the EGF treatment increased (P<.001). However, when N-acetylcysteine or selenium was added with EGF for 1 month, levels of intracellular peroxide and 8-hydroxyguanosine in DNA were comparable to those in control cells (r =.795). Both tumorigenicity (P =.008) and metastatic ability (P<.001) decreased after addition of N-acetylcysteine or selenium.

CONCLUSION

The irreversible changes caused by continuous EGF stimulation of ER-1 cells result from increased oxidative damage in the DNA, which generates tumor cells with more malignant characteristics.

Epstein-Barr virus-associated gastric cancer in a patient with dermatomyositis

A 59-year-old man was admitted presenting systemic rash and muscle weakness. He was diagnosed to have dermatomyositis and a check was made for internal malignancy. Gastrointestinal endoscopy revealed a Borrmann type II tumor on the middle body of the stomach. Biopsy specimens showed a well differentiated adenocarcinoma, and total gastrectomy was performed. The final diagnosis was moderately differentiated adenocarcinoma invading into the proper muscular layer, with metastases to regional lymph nodes. Most of the neoplastic cells were shown to be positive for Epstein-Barr virus by means of EBV-encoded RNA in situ hybridization. The symptoms of dermatomyositis disappeared completely after surgery.

Endoscopic screening for early esophageal cancer by iodine staining in patients with other current or prior primary cancers

BACKGROUND

Although early diagnosis of esophageal carcinoma is an important determinant of outcome, early stage carcinomas are rarely detected on routine endoscopic examination. Iodine staining may be useful in the detection of early stage esophageal carcinoma, especially in high-risk populations. In a prior study, 29.2% (68/233) patients with superficial esophageal carcinoma (SEC) undergoing resection at our hospital had other nonesophageal primary carcinomas, suggesting that patients with nonesophageal primary cancers are at increased risk for the development of esophageal cancer. The aim of the current study was to determine whether endoscopic screening with iodine staining is useful for the detection of SEC in patients with a history of non-esophageal cancers.

PATIENTS AND METHODS

In a prospective study, 331 patients with nonesophageal primary cancers were screened for esophageal cancer by endoscopic examination with iodine staining. All patients were men 55 years of age or older.

RESULTS

Nine patients (2.7%) with SEC were identified. Among these patients, 7 with mucosal cancer were treated by endoscopic mucosal resection, and 2 with submucosal cancer were treated by surgical resection or radiation therapy. Five patients (1.5%) were found to have cancer confined to the epithelium or the lamina propria. These lesions were difficult to detect by conventional endoscopic screening and were cured by endoscopic mucosal resection. After exclusion of 51 patients with head and neck cancer, the incidence of SEC was still 2.1% (6/280), higher than reported in prior screening studies.

CONCLUSIONS

All men with a history of nonesophageal primary cancers should undergo endoscopic screening for esophageal cancer. Endoscopic iodine staining in such patients may be useful in screening for early stage esophageal carcinoma.

Jejunal carcinoid tumor mimicking leiomyosarcoma: preoperative diagnosis by endoscopic biopsy

Primary carcinoid tumor of the jejunum is rare, and is an unusual cause of massive gastrointestinal bleeding. A case of primary jejunal carcinoid tumor in a 39-year-old woman who presented with massive hematochezia is described. Both upper and lower gastrointestinal endoscopies showed no abnormalities. An abdominal computed tomographic scan, small-bowel barium contrast studies, and small-bowel endoscopy showed a subserosal mass, of 5 x 4 cm, with a cavity suggesting central necrosis, and a deep mucosal ulceration, located in the proximal jejunum. Although these clinical presentations were strongly suggestive of a leiomyosarcoma, histologic examination of biopsy samples obtained by enteroscopy confirmed the diagnosis of jejunal carcinoid tumor. The patient underwent radical jejunal resection and recovered uneventfully. In spite of the large size of the tumor, there was one solitary lymph node metastasis, but no evidence of liver metastases. This kind of jejunal carcinoid tumor, presenting with massive gastrointestinal bleeding and a subserosal bulky growth mimicking a leiomyosarcoma, has not been reported previously. Moreover, this is a rare case of a jejunal carcinoid which was diagnosed preoperatively by small bowel-endoscopic biopsy.

Effects of aging and blood pressure on the structure of the thoracic aorta in SAM mice: a model of age-associated degenerative vascular changes

The effects of aging and blood pressure on the structural alterations of the thoracic aorta were examined using male, accelerated senescence-prone, short-lived SAMP11 mice or accelerated senescence-resistant, long-lived SAMR1 mice. The aortic wall thickness increased significantly by 34% in SAMR1 and by 62% in SAMP11 with advanced age. We observed branching, breakage and disorganization of the elastic lamellae, an increase in thin collagen fibrils between the medial smooth muscle cells and hypertrophy but a significant decrease in the number of medial smooth muscle cells with aging in both strains. These alterations observed in SAMP11 occurred earlier and were more exaggerated with advanced age than in SAMR1. The aortic lumen dilated gradually in SAMR1, but narrowed significantly in SAMP11 with aging. The systolic blood pressure did not differ significantly among SAMP11s aged 3-9months, or among all ages of SAMR1. However, it was elevated in SAMP11 at the terminal stage of their life. Our results suggest that the aorta in SAMR1 might reflect the physiological process of aging, whereas SAMP11 showed earlier changes due to the senescence acceleration of the vascular cells, which were exaggerated by the elevated blood pressure.

Senile ocular amyloidosis in SAM and BALB/c strains of mice

We investigated whether amyloid deposition can affect retinal atrophy in old SAMR1, SAMP1 and BALB/c mice. Immunohistochemistry revealed that old SAMP1 mice showed the deposition of the murine senile amyloid protein fibril, AApoA-II in the subconjunctival tissue, the vessel walls near the chamber angle, and the sheaths of the external ocular muscles and the conjunctival glands, but was never observed in the retina or the choroid. Although the old SAMR1 mice also showed a remarkable loss of retinal photoreceptor and ganglion cells, they never showed any amyloid deposition. The BALB/c strain did not showed any amyloid deposition either. Our data suggest that atrophy of the retina is not related to senile systemic amyloidosis in mice.