A novel mouse model of hepatocarcinogenesis triggered by AID causing deleterious p53 mutations.

Activation-induced cytidine deaminase (AID), the only enzyme that is known to be able to induce mutations in the human genome, is required for somatic hypermutation and class-switch recombination in B lymphocytes. Recently, we showed that AID is implicated in the pathogenesis of human cancers including hepatitis C virus (HCV)-induced human hepatocellular carcinoma (HCC). In this study, we established a new AID transgenic mouse model (TNAP-AID) in which AID is expressed in cells producing tissue-nonspecific alkaline phosphatase (TNAP), which is a marker of primordial germ cells and immature stem cells, including ES cells. High expression of TNAP was found in the liver of the embryos and adults of TNAP-AID mice. HCC developed in 27% of these mice at the age of approximately 90 weeks. The HCC that developed in TNAP-AID mice expressed alpha-fetoprotein and had deleterious mutations in the tumour suppressor gene Trp53, some of which corresponded to those found in human cancer. In conclusion, TNAP-AID is a mouse model that spontaneously develops HCC, sharing genetic and phenotypic features with human HCC, which develops in the inflamed liver as a result of the accumulation of genetic changes.

Overexpression of a transcription factor LYL1 induces T- and B-cell lymphoma in mice.

LYL1, a member of the class II basic helix-loop-helix transcription factors, is aberrantly expressed in a fraction of human T-cell acute lymphoblastic leukemia. Here, we generated transgenic mice ubiquitously overexpressing LYL1 using a construct expressing full-length cDNA driven by a human elongation factor 1alpha promoter. Four independent lines exhibiting high LYL1 expression were established. Of these transgenic mice, 96% displayed loss of hair with a short kinked tail. Furthermore, 30% of them developed malignant lymphoma, with an average latent period of 352 days. In these mice, histological examination revealed tumor cell infiltration in multiple organs and immunohistochemical analysis showed that the infiltrated tumor cells were either CD3 or CD45R/B220-positive; fluorescence-activated cell sorter analysis indicated that each tumor consisted either of mainly CD4, CD8 double-positive T cells or mature B cells; the clonality of LYL1-induced lymphoma was confirmed by T-cell receptor rearrangement and immunoglobulin heavy-chain gene rearrangement analyses. Mammalian two-hybrid analysis and luciferase assay suggested that excess LYL1 blocked the dimerization of E2A and thus inhibited the regulatory activity of E2A on the CD4 promoter. Reverse transcription-polymerase chain reaction results showed that the expression of certain E2A/HEB target genes was downregulated. Taken together, our results provide direct evidence that aberrant expression of LYL1 plays a role in lymphomagenesis.

Development of spontaneous tumours and intestinal lesions in Fhit gene knockout mice.

The fragile histidine triad (FHIT) gene is frequently inactivated in various types of tumours. However, the system-wide pathology caused by FHIT inactivation has not been examined in detail. Here we demonstrate that Fhit gene knockout mice develop tumours in the lymphoid tissue, liver, uterus, testis, forestomach and small intestine, together with structural abnormalities in the small intestinal mucosa. These results suggest that Fhit plays important roles in systemic tumour suppression and in the integrity of mucosal structure of the intestines.

Inhibitory effects of Helicobacter pylori infection on murine autoimmune gastritis.

BACKGROUND AND AIM: Long term Helicobacter pylori infection leads to atrophic gastritis but the relation between H pylori infection and autoimmune related atrophic gastritis (AIG) remains unclear. We studied the effects of H pylori infection on the pathophysiology of AIG in mice. MATERIALS AND METHODS: BALB/c nu/nu mice (n=40) with or without H pylori infection received splenocytes from neonatally thymectomised mice to induce AIG. Half of the mice were orally infected with H pylori prior to AIG induction. Histological findings, and local and systemic immune responses were serially evaluated. RESULTS: Two and six months after transfer, parietal cells in uninfected mice were depleted while those in infected mice were well preserved. The degree of gland atrophy (p<0.01), hyperplasia (p<0.01), gastric pH (p<0.05), and serum gastrin levels of infected mice were significantly lower than those of uninfected mice. Serum antiparietal cell antibody levels gradually decreased in infected mice, and were significantly lower than those of uninfected mice at six months (p<0.05). Real time polymerase chain reaction studies revealed significantly higher interleukin 4 (p<0.05) and transforming growth factor beta (p<0.05) gene expression in the gastric mucosa in infected mice than in uninfected mice at both two and six months after AIG induction. CONCLUSIONS: H pylori infection inhibited the development of AIG in mice. Th2-type immune responses and transforming growth factor beta in the gastric microenvironment might be involved in the inhibitory effects of H pylori infection on the development of AIG, in which Th1-type responses have an important role.

Involvement of tumor necrosis factor alpha in intestinal epithelial cell proliferation following Paneth cell destruction.

BACKGROUND: An intravenous injection of diphenylthiocarbazone (dithizone), a zinc chelator, induces selective killing of Paneth cells which have a large amount of zinc in their cytoplasmic granules. A transient wave of intestinal epithelial cell proliferation occurs at 12 h after the injection. Paneth cells have tumor necrosis factor (TNF)-alpha protein in their cytoplasmic granules, and TNF-alpha has a proliferative effect on intestinal epithelial cells in vitro. The aim of this study is to clarify the in vivo role of TNF-alpha in intestinal epithelial cell proliferation using a dithizone-treated rat model. METHODS: Male Wistar rats received a dithizone (100 mg/kg of body weight) injection with or without TNF-alpha inhibitor, pentoxifylline (100 mg/kg), neutralizing anti-TNF-alpha antibody (2 mg/kg), or nuclear transcription factor kappaB (NF-kappaB) inhibitors: pyrrolidine dithiocarbamate (100 mg/kg) or N-acetyl-L-cystein (100 mg/kg). The activation of NF-kappaB was examined by the electrophoretic mobility shift assay, and cellular proliferation by BrdU labeling. RESULTS: Without any inhibitors, dithizone treatment evoked NF-kappaB activation in the ileal mucosa with its peak level at 2 h after the injection. TNF-alpha inhibition reduced the NF-kappaB activation, and blocked a transient wave of epithelial cell proliferation 12 h after the injection. NF-kappaB inhibitors also reduced the NF-kappaB activation and epithelial cell proliferation. CONCLUSIONS: TNF-alpha released from degenerated Paneth cells was, in part, responsible for the intestinal cell proliferation through the activation of NF-kappaB, suggesting its proliferative effect on intestinal epithelial cells.

Failure of ureteric bud invasion: a new model of renal agenesis in mice.

FUBI (failure of ureteric bud invasion) is a highly inbred strain of mouse with a high spontaneous incidence of uni- or bilateral renal agenesis (60%). Bilateral renal agenesis is lethal within 2 days after birth. The primary defect of FUBI is failure of the ureteric bud to penetrate into the metanephric mesenchyme at around embryonic day 11, resulting in apoptosis of metanephric cells and leading to renal agenesis on the affected side. The metanephros seemed to be normal because co-culturing of the FUBI metanephros with homologous spinal cord induced differentiation of the rudiment, but co-culturing with the homologous ureteric bud frequently did not. Genetic analysis revealed that more than two genes were involved in this malformation and we mapped one of the modifier loci, fubi1, on chromosome 2, at approximately 65 cM from the centromere. In this region, there are two possible candidate genes, Wilms' tumor 1 and formin, that play important roles in kidney development. Some of formin mutants shared a similar phenotype with FUBI; however, there was no difference in the expression of formin in embryonic kidneys between FUBI and control NFS/N mice. Studies of fubi1 congenic mice indicated that interaction of two or more loci is essential for the FUBI phenotype.

An electron spin resonance study on alkylperoxyl radical in thin-sliced renal tissues from ferric nitrilotriacetate-treated rats: the effect of alpha-tocopherol feeding.

Formation of excess free radical causes cellular oxidative stress, which has been shown to be associated with a variety of pathologic conditions. While electron spin resonance (ESR) spectroscopy has been the only method to demonstrate the presence of free radicals, its application to tissue samples has been challenging. We report here the successful ESR detection in thin-sliced fresh tissues or frozen sections in a rat model. Ferric nitrilotriacetate (Fe-NTA) induces oxidative renal tubular damage that ultimately leads to high incidence of renal carcinoma in rodents. Twenty minutes after administration of 5 mg iron/kg Fe-NTA to rats, a thin-slice of the kidney was mounted on a tissue-type cell and analyzed by ESR spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). An ESR signal from alkylperoxyl radical adduct was obtained, and the signal was inversely proportional to renal alpha-tocopherol content which was modulated through diet. Furthermore, we undertook ex vivo study using frozen sections. Fe-NTA (1 mM) was added to a rat kidney frozen section for 10 min. After washing the specimen was mounted on a tissue-type cell and analyzed with ESR spin trapping using DMPO. Alkylperoxyl radical signal was dependent on thickness, incubation time and renal tissue levels of alpha-tocopherol, and was reduced by preincubation with catalase or dimethyl sulfoxide but not with alpha-tocopherol outside tissue. This versatile method facilitates identification of free radicals in pathologic conditions, and may be useful for selection of antioxidants.

Analysis of cytokines in the early development of gastric secondary lymphoid follicles in Helicobacter pylori-infected BALB/c mice with neonatal thymectomy.

Immunological interaction between the host and Helicobacter pylori seems to play a critical role in follicular formation in gastric mucosa. We reported H. pylori-induced follicular gastritis model using neonatally thymectomized mice. In this study, we investigated the involvement of various cytokines in this model. BALB/c mice were thymectomized on the third day after birth (nTx). At 6 weeks old, these mice were orally infected with H. pylori. Histological studies showed that follicular formation occurred from 8 weeks after the infection and that most of the infiltrating lymphocytes were CD4(+) and B cells. Neutrophils increased transiently at 1 week after the infection. Gamma interferon, interleukin-7 (IL-7), and IL-7 receptor were expressed in the stomach of the nTx mice irrespective of the infection. In contrast, expressions of the tumor necrosis factor alpha, IL-4 and lymphotoxin-alpha genes were remarkably upregulated by the infection. Our findings suggest that follicular formation may require cooperative involvement of a Th2-type immune response, tumor necrosis factor alpha and lymphotoxin-alpha in addition to the Th1-type immune response in H. pylori-induced gastritis in nTx mice.

Identification of xanthine dehydrogenase/xanthine oxidase as a rat Paneth cell zinc-binding protein.

Paneth cells are zinc-containing cells localized in small intestinal crypts, but their function has not been fully elucidated. Previously, we showed that an intravenous injection of diphenylthiocarbazone (dithizone), a zinc chelator, induced selective killing of Paneth cells, and purified a zinc-binding protein in Paneth cells. In the present study, we further characterized one of these proteins, named zinc-binding protein of Paneth cells (ZBPP)-1. Partial amino acid sequences of ZBPP-1 showed identity with rat xanthine dehydrogenase (XD)/xanthine oxidase (XO). Anti-rat XD antibody (Ab) recognized ZBPP-1, and conversely anti ZBPP-1 Ab recognized 85 kDa fragment of rat XD in Western blotting. Messenger RNA and protein levels of XD were consistent with our previous data on the fluctuation of Paneth cell population after dithizone injection. Thus, ZBPP-1 is an 85 kDa fragment of XD/XO in Paneth cells. XD/XO in Paneth cells may play important roles in intestinal function.

Five quantitative trait loci affecting 4-nitroquinoline 1-oxide-induced tongue cancer in the rat.

In our previous study, Dark-Agouti (DA) rats were found to be highly susceptible to 4-nitroquinoline 1-oxide (4NQO)-induced tongue carcinoma (TC), whereas Wistar / Furth (WF) rats were barely susceptible. Interval mapping analysis of reciprocal backcross rats showed two quantitative trait loci (QTL) on rat chromosomes (RNO) 1 and 19. In the present study, a composite interval mapping analysis was applied to 4NQO-induced TC in 130 (DA x WF) F2 rats, demonstrating five independent QTL, Tongue squamous cell carcinoma 1 - 5 (Tscc1 - 5), responsible for phenotypic differences in the size and number of TCs in the two strains. Two of these QTL were mapped on RNO1, and the others were mapped on RNO4, 14, and 19. The DA allele at these loci consistently yielded semidominant susceptibility to TC. Out of the five loci detected in this F2 generation, Tscc1 and 2 were identical to Stc1 and Rtc1 described in our previous study, but the other three were novel. We propose a new nomenclature consistent with their function. Genome-wide screening of the F2 progeny also suggested the presence of three additional QTL on RNO5, 6, and 10. The possible roles of these loci in tongue carcinogenesis are discussed.

Enhanced expression of transforming growth factor (TGF) -alpha precursor and TGF-beta1 during Paneth cell regeneration.

An intravenous injection of diphenylthiocarbazone (dithizone), a zinc chelator, induces selective killing and rapid regeneration of Paneth cells, which have a large amount of zinc in their cytoplasmic granules. We examined the expression pattern of transforming growth factor (TGF) -alpha and TGF-beta1 in this regenerative process. Messenger RNA expression of TGF-alpha and TGF-beta1 reached their peaks at 12 and 24 hr after dithizone injection, respectively. Protein expression of TGF-alpha precursor and TGF-beta1 increased to a maximum at 24 and 72 hr, respectively. Their immunoreactivities were localized in the epithelial cells in the vicinity of Paneth cells, whereas they were prominent in the upper half of the crypts in control rats. In conclusion, destruction of Paneth cells induced TGF-alpha precursor expression, followed by an increase of TGF-beta1 especially in the crypt bases. This unique expression pattern of two growth factors may be involved in rapid regeneration of Paneth cells.

Autoimmune dilated cardiomyopathy in PD-1 receptor-deficient mice.

Dilated cardiomyopathy is a severe pathology of the heart with poorly understood etiology. Disruption of the gene encoding the negative immunoregulatory receptor PD-1 in BALB/c mice, but not in BALB/c RAG-2-/- mice, caused dilated cardiomyopathy with severely impaired contraction and sudden death by congestive heart failure. Affected hearts showed diffuse deposition of immunoglobulin G (IgG) on the surface of cardiomyocytes. All of the affected PD-1-/- mice exhibited high-titer circulating IgG autoantibodies reactive to a 33-kilodalton protein expressed specifically on the surface of cardiomyocytes. These results indicate that PD-1 may be an important factor contributing to the prevention of autoimmune diseases.

Allelic imbalances on chromosome 20 in human transitional cell carcinoma.

One determinant of the survival time of cancer-bearing patients may be genetic factors. In chemically induced bladder cancers of mice, differences in survival time have been observed among several inbred strains. Genetic analyses of such differences in crosses between C57BL / 6 and NON mice revealed that the survival period is determined by two quantitative trait loci on mouse chromosomes 6 and 2, respectively. We explored the possibility that genetic alterations may be observed in the syntenic conserved chromosomal regions of human transitional cell carcinoma corresponding to mouse chromosomes 6 and 2. Human chromosome 7, containing a region syntenic to mouse chromosome 6, is reported to harbor frequent genetic alterations in bladder cancers. In this study, we investigated 70 human urothelial cancers for possible genetic alterations on human chromosome 20p and 20q containing regions syntenic to mouse chromosome 2. Allelic imbalances were observed in 22 cases (31.4%) on 20p and 18 cases (25.7%) on 20q. Those allelic imbalances, however, did not show a direct correlation with the prognosis of the patients. Higher grade tumors tended to show more frequent imbalances on chromosome 20; however, this tendency was not significant.

Investigation of possible involvement of several genes related to development of hepatocarcinogenesis in rats.

A comparative study on the possible involvement of several genes in the susceptibility of chemical carcinogenesis was carried out using carcinogen-resistant DRH rat and -sensitive Donryu and F344 rats. Previously, we observed that the induction of glutathione S-transferase placental form (GST-P) in the liver of Donryu rats by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) was significantly greater than that of DRH rats. In the present study, we tentatively determined base sequences of the enhancer region including GPE-I and GPE-II (GST-P enhancers I and II) of GST-P genes of DRH, Donryu and F344 rats, but we did not observe any nucleotide polymorphism around these regions. Furthermore, the mRNA levels of silencer binding protein (NFA-1) for the GST-P promoter of rat liver were also similar in the DRH and Donryu rats. Since clonal expansion of putative preneoplastic GST-P-positive foci in the DRH rat liver was significantly suppressed during 3'-Me-DAB administration, we examined whether two opposite growth controlling factors, TGF-alpha and TGF-beta, may participate in such suppression of growth. It was supposed that mannose 6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R), at least in part, activates TGF-beta preproprotein. However, we observed that the levels of M6P/IGF2R mRNA in the livers of DRH were not higher than those of Donryu rats after being fed 3'-Me-DAB for 8 weeks. Another important factor in the carcinogenesis is insulin-like growth factor II itself. Although liver tumors induced by 3'-Me-DAB in F344 had high levels of IGF-II mRNA, little IGF-II gene expression existed in normal adult livers of Donryu, F344 and DRH rats. High levels of IGF-II mRNA were detected similarly in the livers of neonates from all these three strains of rats. Finally, we detected a significant increase of AFP (alpha-fetoprotein) mRNA in the livers of Donryu rats around 6 to 8 weeks from the start of 3'-Me-DAB feeding, which is in parallel with detrimental effects of this carcinogen on these rats. A reduced induction of AFP mRNA was observed in DRH rats under the same conditions. Further study will be needed to explain the lower tumor susceptibility in the DRH rat.

Expression of stress-response and cell proliferation genes in renal cell carcinoma induced by oxidative stress.

Ferric nitrilotriacetate induces oxidative damage in renal proximal tubules that ultimately leads to a high incidence of renal cell carcinoma (RCC) in rats. In search of genes specifically involved in oxystress-induced carcinogenesis, we have applied a modified fluorescent differential display technique to the tumors and an established cell line as well as their non-neoplastic counterparts. We screened approximately 84,000 products. Reverse Northern blotting confirmed differential expression of 20 transcripts, which showed either significant increase, decrease or lack of expression in the RCCs. Five cDNA clones encoded novel products of unknown function. Fifteen cDNA clones were identified by homology search, which included annexin II, Y-box binding protein, ribosomal proteins, heat shock proteins, DNA polymerase, nonmuscle caldesmon (increased); protein tyrosine phosphatase (decreased); selenoprotein P, stromal cell-derived factor 1, intestinal trefoil protein, nicotinamide adenine dinucleotide, reduced form (NADH) dehydrogenase, and insulin-like growth factor binding protein 7 (deleted). Most of the identified genes were associated with stress-response or cellular proliferation. These results suggest that multiple, interactive genetic pathways are involved in carcinogenesis induced by oxidative stress.

Genetic resistance to chemical carcinogen-induced preneoplastic hepatic lesions in DRH strain rats.

DRH strain rats were established by inbreeding a closed colony of Donryu rats continuously fed the chemical hepatocarcinogen 3'-methyl-4-dimethylaminoazobenzene for over 10 years. They are highly resistant to chemical induction of liver cancer and preneoplastic lesions. We studied the genetic basis of DRH resistance to preneoplastic lesions by analyzing 108 (F344 x DRH)F2 male rats fed 3'-methyl-4-dimethylaminoazobenzene for 7 weeks. Five parameters of preneoplastic liver lesions were selected for quantitative analysis: (a) number of glutathione S-transferase placental form-positive foci per unit area of liver section; (b) percentage area occupied by the foci; (c) average size of foci; (d) glutathione S-transferase placental form mRNA level; and (e) gamma-glutamyltranspeptidase mRNA level. Furthermore, O6-methylguanine DNA methyltransferase and mannose 6-phosphatase/insulin-like growth factor 2 receptor mRNA levels were quantified. Composite interval mapping analysis showed that there were two remarkably significant clusters of quantitative trait loci affecting preneoplastic liver lesions on chromosomes 1 and 4. These clusters were designated collectively as Drh1 and Drh2, respectively. The functions of the recessive DRH allele of Drh1 and the semidominant DRH allele of Drh2 were to suppress the phenotypes of precancerous lesions. Each cluster showed two to three subpeaks in linkage likelihood plots, suggesting the presence of several closely linked quantitative trait loci affecting preneoplastic lesions. Possible candidate genes at each locus will be discussed. Expression of O6-methylguanine DNA methyltransferase and mannose 6-phosphatase/insulin-like growth factor 2 receptor did not affect DRH resistance to hepatocarcinogenesis, although they were polymorphic between DRH and F344 rats.

Antioxidant alpha-tocopherol ameliorates glycemic control of GK rats, a model of type 2 diabetes.

We have shown recently that oxidative stress by chronic hyperglycemia damages the pancreatic beta-cells of GK rats, a model of non-obese type 2 diabetes, which may worsen diabetic condition and suggested the administration of antioxidants as a supportive therapy. To determine if natural antioxidant alpha-tocopherol (vitamin E) has beneficial effects on the glycemic control of type 2 diabetes, GK rats were fed a diet containing 0, 20 or 500 mg/kg diet alpha-tocopherol. Intraperitoneal glucose tolerance test revealed a significant increment of insulin secretion at 30 min and a significant decrement of blood glucose levels at 30 and 120 min after glucose loading in the GK rats fed with high alpha-tocopherol diet. The levels of glycated hemoglobin A1c, an indicator of glycemic control, were also reduced. Vitamin E supplementation clearly ameliorated diabetic control of GK rats, suggesting the importance of not only dietary supplementation of natural antioxidants but also other antioxidative intervention as a supportive therapy of type 2 diabetic patients.

Overexpression of the hOGG1 gene and high 8-hydroxy-2'-deoxyguanosine (8-OHdG) lyase activity in human colorectal carcinoma: regulation mechanism of the 8-OHdG level in DNA.

8-Hydroxy-2'-deoxyguanosine (8-OHdG) is one of the most abundant oxidatively modified lesions in DNA. Our previous study (Kondo et al, Free Radic. Biol. Med., 27: 401-410, 1999) revealed that human colorectal carcinoma cells are oxidatively stressed based on 8-OHdG determination. To elucidate 8-OHdG metabolism and its clinical significance in colorectal carcinoma, we studied the 8-OHdG repair system in DNA by measuring specific lyase activity and hOGG1 expression using quantitative-competitive reverse transcription-PCR. In addition, we searched for the presence of mutations and single nucleotide polymorphisms of the hOGG1 gene by single-strand conformational polymorphism and sequencing analyses. It was found that 8-OHdG-specific lyase activity and hOGG1 expression were significantly up-regulated in carcinoma, and a proportional association between 8-OHdG levels and either 8-OHdG lyase activity (r = 0.641, P < 0.05) or hOGG1 expression (r = 0.702, P < 0.05) was present. Whereas no difference was detected in the 8-OHdG level between early- and advanced-stage cancer, lyase activity (1.2-fold) and hOG1 expression (1.6-fold) were significantly increased in advanced-stage cancer. No mutation was found in the 25 tumors examined. Three kinds of single nucleotide polymor. phism were observed, including that of codon 326 (Ser/Cys) in exon 7. However, there was no correlation between any of the three polymorphic patterns and either 8-OHdG level or lyase activity. These results suggest that increased 8-OHdG levels in colorectal carcinoma are attributed to increased formation and are maintained by induced 8-OHdG repair activity at appropriate high levels. Our results may offer a unique approach in the development of preventive and therapeutic interventions as well as new insights into the pathogenesis of colorectal carcinoma.

Polygenic resistance to mouse pulmonary adenomas.

Susceptibility to urethan-induced pulmonary adenomas (PA) in mice is under polygenic control. To analyze these traits in detail, we generated a set of recombinant inbred (RI) mouse strains, called SMXA, from an intercross between PA-susceptible A/J and resistant SM/J, and established a strain distribution pattern (SDP) table of 158 marker loci for SMXA RI strains. From the SDP table, it was possible to estimate the allele for 4 known PA susceptibility (Pas) loci in all members of SMXA RI strains. We compared combinations of Pas loci alleles with the data of number of PA induced by urethan. One of the RI strains, SMXA24, showed extremely low PA numbers, whereas they had the A/J-derived alleles at all 4 Pas loci. F1 hybrids of SMXA24 and A/J developed as few PA as SMXA24 on exposure to urethan. To confirm the hypothesis that SMXA24 has dominant PA resistance gene(s), we examined a backcross generation to A/J for multiplicity of PA. A preliminary genome scan followed by quantitative trait locus analysis revealed two resistance loci, one on mouse chromosome 11 (MMU11) (logarithm of odds [LOD] score 4.35) and another on MMU12 (LOD score 6.47). They were named Par1 and Par3, respectively. Both loci were epistatic to Pas1, the major susceptibility loci on MMU6. We next asked if such dominant resistance loci play some role in human lung cancer by studying possible loss of heterozygosity (LOH) at syntenic chromosomal segments in 79 human lung cancers, including 30 adenocarcinomas, 25 squamous cell carcinomas (SQ), and 24 small cell carcinomas (SCC). The map positions of Par1 and Par3 correspond to human 17q11-23 and 14q11-24. Of 30 adenocarcinomas, LOH was found in 53% at 17q and in 30% at 14q. For both SQ and SCC, LOH in 17q were about 10%, but LOH in 14q was about 30% to 42%. Therefore, a gene in 17q seemed to be selective for adenocarcinomas, probably at the level of the target cell. In contrast, another gene in 14q affected all 3 types of lung carcinomas, suggesting it is related to the progression of lung tumors in general. A comparative approach may provide useful information for understanding human cancers.

Serum 4-hydroxy-2-nonenal-modified albumin is elevated in patients with type 2 diabetes mellitus.

4-Hydroxy-2-nonenal (HNE) is one of the major lipid peroxidation products with cytotoxic and mutagenic activity. It further reacts with protein residues such as histidine to generate stable Michael adducts. To evaluate the status of oxidative stress in the serum of type 2 diabetes mellitus, we constructed a sandwich enzyme-linked immunosorbent assay to measure serum HNE-modified albumin by the use of a specific monoclonal antibody (HNEJ-2) against HNE-histidine adducts as well as an antibody against human serum albumin. Serum of type 2 diabetes outpatients revealed significantly higher levels of HNE-modified albumin (736.1 +/- 34.2 pmol/ml, n = 54) than the matched nondiabetics (611.4 +/- 39.1 pmol/ml, n = 30; means +/- SEM; p = 0.018). However, no significant correlation was observed in diabetic outpatients between the levels of HNE-modified albumin and clinical parameters such as fasted blood glucose, HbA1c, diabetes duration, or complications. Our data demonstrated the increased formation of serum HNE-modified albumin in type 2 diabetic outpatients in the milieu between liver and vascular lumina, indicating the presence of oxidative stress.