Differential acetylation of Tat coordinates its interaction with the co-activators cyclin T1 and PCAF

The HIV-1 transactivator protein, Tat, is an atypical transcriptional activator that functions through binding, not to DNA, but to a short leader RNA, TAR. Although details of its functional mechanism are still unknown, emerging findings suggest that Tat serves primarily to adapt co-activator complexes such as p300, PCAF and P-TEFb to the HIV-1 long terminal repeat. Hence, an understanding of how Tat interacts with these cofactors is crucial. It has recently been shown that acetylation at a single lysine, residue 50, regulated the association of Tat with PCAF. Here, we report that in the absence of Tat acetylation, PCAF binds to amino acids 20-40 within Tat. Interestingly, acetylation of Tat at Lys28 abrogates Tat-PCAF interaction. Acetylation at Lys50 creates a new site for binding to PCAF and dictates the formation of a ternary complex of Tat-PCAF-P-TEFb. Thus, differential lysine acetylation of Tat coordinates the interactions with its co-activators, cyclin T1 and PCAF. Our results may help in understanding the ordered recruitment of Tat co-activators to the HIV-1 promoter.

Effect of alcohol on the secretion of tumor necrosis factor-alpha by macrophages in the presence of rat serum

BACKGROUND

It is suggested that endotoxin, proinflammatory cytokines, and lipopolysaccharide-binding protein (LBP) play an important role in the development of alcoholic liver disease. Our previous study showed that splenic macrophages were important for endotoxin uptake and excessive production of tumor necrosis factor (TNF) in rats given large amounts of alcohol. To determine the pathophysiological roles of macrophages in alcoholic liver disease, we examined the effect of ethanol on TNF-alpha secretion of rat Kupffer cells, alveolar macrophages, and peritoneal macrophages in the presence or absence of LBP.

METHODS

Kupffer cells, alveolar macrophages, and peritoneal macrophages were isolated from male Sprague Dawley rats. After the preculture in the medium containing 0, 10, 50, and 100 mmol/liter of ethanol, TNF-alpha secretion by these cells incubated with 100 ng/ml of endotoxin in the presence or absence of LBP (1% rat serum) was determined.

RESULTS

In the absence of LBP, an addition of ethanol to the medium suppressed TNF-alpha secretion of alveolar macrophages. Kupffer cells and peritoneal macrophages were less affected. Addition of LBP led to marked enhancement (7- to 24-fold) of TNF-alpha secretion of macrophages either with or without ethanol in the medium. Although ethanol tended to suppress TNF-alpha secretion of these cells, alveolar macrophages were less affected in the presence of LBP.

CONCLUSIONS

Serum LBP enhances the secretion of TNF-alpha by macrophages. Alveolar macrophages may be important for excessive production of TNF-alpha in chronic alcoholics with endotoxemia.

A complex with chromatin modifiers that occupies E2F- and Myc-responsive genes in G0 cells

E2F-6 contributes to gene silencing in a manner independent of retinoblastoma protein family members. To better elucidate the molecular mechanism of repression by E2F-6, we have purified the factor from cultured cells. E2F-6 is found in a multimeric protein complex that contains Mga and Max, and thus the complex can bind not only to the E2F-binding site but also to Myc- and Brachyury-binding sites. Moreover, the complex contains chromatin modifiers such as a novel histone methyltransferase that modifies lysine 9 of histone H3, HP1gamma, and Polycomb group (PcG) proteins. The E2F-6 complex preferentially occupies target promoters in G0 cells rather than in G1 cells. These data suggest that these chromatin modifiers contribute to silencing of E2F- and Myc-responsive genes in quiescent cells.

Reduced expression of p16 and p27 proteins in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor with a high incidence in east Asian countries. Inactivation of cyclin-dependent kinase (CDK) inhibitors (CKIs) and overexpression of G1 cyclin has been thought to be important for tumor development. To determine whether reduction of CKI (p16 and p27) expression was associated with NPC development, we performed immunohistochemical staining of NPC specimens from 20 patients. We found that p16 and p27 proteins were negative in 8 of 20 and 16 of 20 cases, respectively; that either p16 or p27 proteins were negative in 17 of 20; and that both p16 and p27 were negative in 7 of 20. Excepting the cases in which both CKIs were negative, negativity of p27 alone was statistically higher than that of p16 (9/20 versus 1/20, P = .022), suggesting that the reduction of p27 protein is an important event for the multi-step process of NPC development.

HIV-1 transcription: activation mediated by acetylation of Tat

Acetylation of HIV-1 Tat stimulates transcriptional elongation by dissociating Tat from TAR, a transactivation response RNA element in nascent HIV-1 transcripts. In the March issue of Molecular Cell, Mujtaba et al. show that the bromodomain of PCAF acetylase specifically binds to acetylated Tat and leads to dissociation of Tat from TAR.

Frequent beta-catenin mutation and cytoplasmic/nuclear accumulation in pancreatic solid-pseudopapillary neoplasm

Significance of Wnt signaling with beta-catenin mutations on solid-pseudopapillary neoplasm (SPN) of the pancreas was studied by immunohistochemistry and molecular analysis. On immunohistochemistry, all 18 SPNs tested showed diffuse cytoplasmic/nuclear positivity for beta-catenin. Upon direct DNA sequencing of exon 3 of the beta-catenin gene, 15 (83%) of the 18 SPNs showed 1-bp missense mutation in codons 32 (5 cases), 33 (3 cases), 34 (3 cases), 37 (3 cases), and 41 (1 case). Immunoreactivity for cyclin D1, one of the intranuclear targets of beta-catenin complexes, was found in tumor cells of more than half the tumor cells of all of the 18 SPNs. The present study strongly suggested a significant role of Wnt signaling, mostly associated with beta-catenin mutations in the tumorigenesis of SPN.

Catecholamines and opioid peptides increase in plasma in humans during possession trances

Naturally induced possession trances have been observed in healthy people of many societies. The neurophysiological basis of this phenomenon remains unknown, however, because of the difficulty in accessing subjects in trances due to their sacred context. In the present study, we measured the plasma levels of several neuroactive substances from subjects exhibiting or lacking possession trance characteristics during Balinese dedicatory dramas under natural conditions. The trance group exhibited significant increases in plasma concentrations of noradrenaline, dopamine and beta-endorphin, compared with controls who performed the same actions as the trance group. The present finding suggests that catecholamines and opioid peptides are involved in possession trances.

Ley glycolipid-recognizing monoclonal antibody inhibits procoagulant activity and metastasis of human adenocarcinoma

Tumor procoagulant is associated with cancer at advanced stages of malignancy such as infiltration and metastasis. In the present study, we investigated the role of Ley glycolipid in the mechanism of cancer metastasis. Ley glycolipid acts as an important cofactor in the expression of the blood-coagulating activity of cancer cell-derived coagulating activity 1 (CCA-1), which is one of the known tumor procoagulants. Monoclonal antibody (MoAb) FS01, which serves as the Ley-recognizing epitope, inhibits the procoagulant activity of CCA-1 was found to dose-dependently inhibit the procoagulant activity of normal plasma induced by the human lung adenocarcinoma cell line, HAL8, which shows a high level of Ley expression. It did not, however, inhibit the procoagulant activity of the human colon cancer cell line, RPMI4788, which does not express Ley. Administration of FS01 MoAb inhibited lung metastasis of HAL8 cells, but not that of RPMI4788. The absence of antibody-dependent cellular cytotoxicity and complement-mediated cytotoxicity of FS01 MoAb against the HAL8 cell line suggests that the inhibition of HAL8 metastasis by FS01 MoAb derives from the inhibition of blood-coagulating activity of the latter. These findings indicate that Ley glycolipid plays an important role in the mechanism of cancer metastasis via the procoagulant activity of CCA-1.

Role of galectin-3 in adenocarcinoma liver metastasis

Galectin-3 is a lactosamine-specific lectin that binds to laminin sugar-sites, and up-regulated expression of galectin-3 in primary colorectal cancer is involved in cancer progression and metastasis. Inhibitory effects of cell adhesion and liver metastasis of adenocarcinoma via portal vein by lectin-binding sugar and anti-galectin-3 antibody was examined to determine the role of galectin-laminin binding in cancer liver metastasis. Highly metastatic adenocarcinoma cell lines XK4-A3 and RPMI4788 were used in in vitro cell attachment and nude mice liver metastatic experiments, and inhibitory effects of anti-galectin-3 antibody or lectin-binding sugars were examined. The in vitro adhesion assay demonstrated that the anti-galectin-3 antibody and alpha-lactose inhibited XK4-A3 and RPMI4788 cell adhesion to laminin in a dose-dependent manner. The liver metastasis of XK4-A3 and RPMI4788 was reduced 50 and 60%, respectively (P<0.001) by alpha-lactose treatment. Anti-galectin-3 antibody also inhibited liver metastasis in a dose-dependent manner, and maximum inhibition rate was 66% for XK4-A3 and 90% for RPMI4788. Galectin-3 plays an important role in liver metastasis of adenocarcinoma by the mechanisms of galectin-3 binding to laminin. Inhibition of galectin-3 on cancer cell surface induces reduced cell attachment to laminin and liver metastasis.

Transcriptional coactivator protein p300. Kinetic characterization of its histone acetyltransferase activity

The p300/cAMP response element-binding protein-binding protein (CBP) family members include human p300 and cAMP response element-binding protein-binding protein, which are both important transcriptional coactivators and histone acetyltransferases. Although the role of these enzymes in transcriptional regulation has been extensively documented, the molecular mechanisms of p300 and CBP histone acetyltransferase catalysis are poorly understood. Herein, we describe the first detailed kinetic characterization of p300 using full-length purified recombinant enzyme. These studies have employed peptide substrates to systematically examine the substrate specificity requirements and the kinetic mechanism of this enzyme. The importance of nearby positively charged residues in lysine targeting was demonstrated. The strict structural requirement of the lysine side chain was shown. The catalytic mechanism of p300 was shown to follow a ping-pong kinetic pathway and viscosity experiments revealed that product release and/or a conformational change were likely rate-limiting in catalysis. Detailed analysis of the p300 selective inhibitor Lys-CoA showed that it exhibited slow, tight-binding kinetics.

A long-term survival case of pancreatic poorly differentiated adenocarcinoma with transcatheter arterial embolization and combination chemotherapy

A 66-year-old woman complained of supraclavicular lymph node swelling during her initial visit to an outpatient clinic. Computed tomography revealed a hypervascular tumor in the uncus of the pancreas (2.0 x 2.0 cm), therefore a needle biopsy of the pancreas was performed. A poorly differentiated adenocarcinoma was identified. Transcatheter arterial embolization using adriamycin and gelatin sheet was performed. To alleviate her symptoms (movement disorder of neck, etc.), initial chemotherapy; FP (5-fluorouracil and cisplatin intravenously) was continued for 6 cycles with her consent, and subsequently MF (methotrexate and 5-fluorouracil intravenously) for 14 cycles. This patient survived with transcatheter arterial embolization, FP and MF combination chemotherapies for 24 months after presenting with the symptoms. To our knowledge, this is the longest surviving case of pancreatic poorly differentiated adenocarcinoma (Stage IV). In conclusion, this present case suggests that transcatheter arterial embolization, FP and MF combination therapy may have an effect at prolonging survival in poorly differentiated pancreatic adenocarcinoma.

The p400 complex is an essential E1A transformation target

Here, we report the identification of a new E1A binding protein complex that is essential for E1A-mediated transformation. Its core component is a SWI2/SNF2-related, 400 kDa protein (p400). Other components include the myc- and p/CAF-associated cofactor, TRRAP/PAF400, the DNA helicases TAP54alpha/beta, actin-like proteins, and the human homolog of the Drosophila Enhancer of Polycomb protein. An E1A mutant, defective in p400 binding, is also defective in transformation. Certain p400 fragments partially rescued this phenotype, underscoring the role of E1A-p400 complex formation in the E1A transforming process. Furthermore, E1A and c-myc each alter the subunit composition of p400 complexes, implying that physiological p400 complex formation contributes to transformation suppression.

Crush and imprint cytology of subependymoma: a case report

BACKGROUND

There are few descriptions of the cytologic features of subependymoma because this neoplasm is rare and most commonly encountered incidentally at autopsy. Here we report a surgical case of subependymoma occurring in the lateral ventricle and provide the first documentation of the crush cytologic features of this tumor.

CASE

A 34-year-old woman was found to have a tumorous lesion in the right lateral ventricle. At surgery, a 2-cm-diameter tumor was detected in the anterior horn. Histologic examination during surgery revealed that the mass was composed of loose,fibrillary networks and clusters of nuclei showing mild pleomorphism. A number of microcystic formations were evident. Histologically, the neoplasm was considered benign--specifically, a subependymoma. Papanicolaou- or Giemsa-stained crush specimens and imprint smears were also prepared. The cytologic morphology was fundamentally the same as the histologic. In the crush specimens, microcystic formations were readily visible. Moreover, details of the cellular morphology were more easily recognized in the cytologic slides than in the frozen sections.

CONCLUSION

Cytologic examination, particularly crush cytology, appears to be useful for the rapid diagnosis of subependymoma during surgery in combination with the examination of frozen histologic sections.

Endothelin-1 plays a major role in portal hypertension of biliary cirrhotic rats through endothelin receptor subtype B together with subtype A in vivo

BACKGROUND/AIMS

Endothelin-1 has been suggested to play a key role in cirrhotic portal hypertension, but a role of its receptors in vivo is not fully elucidated.

METHODS

Biliary cirrhosis was induced by bile duct ligation. Expressions of endothelin-1 and its receptors were evaluated by radioimmunoassay and/or reverse-transcription polymerase chain reaction. Hemodynamics were studied using endothelin receptor agonist or antagonist.

RESULTS

Portal pressure and hepatic endothelin-1 concentrations progressively increased in parallel after bile duct ligation. Gene expression of hepatic prepro-endothelin-1 and endothelin B receptor enhanced after bile duct ligation, while that of endothelin A receptor was unchanged. Intraportal administration of endothelin-1 or endothelin B receptor agonist sarafotoxin 6c (0.5 nmol/kg, respectively) progressively raised portal pressure in both sham and cirrhotic rats. Portal hypertensive effect of sarafotoxin 6c was more intense in cirrhotic rats than sham animals. Neither endothelin A receptor antagonist FR139317 (1 mg/kg) nor endothelin B receptor antagonist BQ788 (1 mg/kg) alone ameliorated cirrhotic portal hypertension. Only the combined endothelin A and B blockade was associated with a decrease in portal pressure in cirrhotic rats.

CONCLUSIONS

These results indicate that endothelin-1 plays a major role in cirrhotic portal hypertension through endothelin receptor subtype B together with subtype A in vivo.

Phospholipase A2 mediates ischemic injury in the hippocampus: a regional difference of neuronal vulnerability

Although it is well known that the hippocampal CA1 subfield is highly vulnerable to ischemic injury, cellular mechanisms leading to this neuronal degeneration are not fully understood. Using organotypic cultures of rat hippocampal slices, we determined whether phospholipase A2 (PLA2) is activated in response to ischemic conditions (OGD; oxygen and glucose deprivation). The PLA2 activity in the pyramidal cell layer increased immediately following a 35-min exposure to OGD, which was likely to be mediated by selective activation of cytosolic Ca2+-dependent PLA2 subtype (cPLA2). This enhancement lasted for at least 24 h. Interestingly, no apparent increase was detected in the dentate gyrus. Twenty-four hours after the OGD exposure, neuronal death was detected mainly in the CA1 region of hippocampal slices. To examine whether the PLA2 activation is causally or protectively involved in the ischemic injury, we investigated the effect of pharmacological blockade of PLA2 on the OGD-induced neuronal death. The PLA2 inhibitor bromophenacyl bromide efficiently prevented the cell death in a concentration-dependent manner. Similar results were obtained for the selective cPLA2 inhibitor AACOCF3. However, the Ca2+-independent PLA2 inhibitor bromoenol lactone and the secretory PLA2 inhibitor LY311727 were virtually ineffective. These results suggest that cPLA2 plays a causative role in the neuronal death following OGD exposure. Thus, the present study may provide novel therapeutic targets for the development of neuroprotective agents.

ATP-dependent nucleosome remodeling and histone hyperacetylation synergistically facilitate transcription of chromatin

Drosophila nucleosome remodeling factor (NURF) is an ISWI-containing protein complex that facilitates nucleosome mobility and transcriptional activation in an ATP-dependent manner. Numerous studies have implicated histone acetylation in transcriptional activation. We investigated the relative contributions of these two chromatin modifications to transcription in vitro of a chromatinized adenovirus E4 minimal promoter that contains binding sites for the GAL4-VP16 activator. We found that NURF could remodel chromatin and stimulate transcription irrespective of the acetylation status of histones. In contrast, hyperacetylation of histones in the absence of NURF was unable to stimulate transcription, suggesting that NURF-dependent chromatin remodeling is an obligatory step in E4 promoter activation. When chromatin templates were first hyperacetylated and then incubated with NURF, significantly greater transcription stimulation was observed. The results suggest that changes in chromatin induced by acetylation of histones and the mobilization of nucleosomes by NURF combine synergistically to facilitate transcription. Experiments using single and multiple rounds of transcription indicate that these chromatin modifications stimulate transcription preinitiation as well as reinitiation.

Pulmonary artery dissection in patients without underlying pulmonary hypertension

AIMS

Pulmonary artery (PA) dissection is a rare event which usually occurs in patients with underlying pulmonary hypertension. We describe two patients who developed PA dissection without pre-existing pulmonary hypertension and present an extensive review of the literature.

METHODS AND RESULTS

In the first patient (a 59-year-old woman), acute-onset dyspnoea was initially thought to have been caused by pulmonary thrombosis, and thromboendarterectomy was performed. Histologically, pulmonary dissection without external rupture was evident, chiefly in the right main PA. In the second patient, an 85-year-old man who had hypergammaglobulinaemia of unknown cause and died from a haemorrhagic gastric ulcer, arterial dissection was detected at autopsy. There was no underlying pulmonary hypertension in either patient. Although the true reason for the development of dissection is unclear, pre-existing inflammation was considered to be related to its formation, at least in the second case.

CONCLUSIONS

A literature review indicated that idiopathic and inflammation-related PA dissection is extremely unusual. Since PA dissection is very rare, it is important to be aware of its features in order to make a correct diagnosis.

Sociodemographic and clinical characteristics of psychiatric patients coercively brought to hospitals

In order to clarify the sociodemographic and clinical characteristics of psychiatric patients with poor motivation for treatment, we examined patients who were coercively brought to hospitals. Sociodemographic and clinical data on 287 inpatients from two private psychiatric hospitals in Japan were retrospectively analyzed. All patients were in the hospitals on 1 April 1997 and had received treatment prior to this admission. Of these inpatients, 67 (23.3%) were coercively brought to hospitals. Multiple logistic regression was performed on the data of these patients to identify the factors associated with their resistance to visiting the hospital. From the results of multivariate analysis, four characteristics were associated with patients coercively brought to hospitals, namely medication compliance, receiving regular outpatient treatment or not, a history of self-aggression or aggressive behavior towards others, and living arrangements. For patients who had lived with relatives before hospitalization, the primary caregiver being a parental caregiver was associated with patients coercively brought to hospitals, although it was not statistically significant. In addition, agitation was associated with patients not coercively brought to the hospital according to multivariate analysis. The present results suggest that psychiatric patients with poor motivation are more likely to have poor medication compliance, to have not received regular outpatient treatment, to have a history of aggressive behavior and to live alone. For patients who lived with their caregivers prior to hospitalization, poorly motivated patients tended to have parental caregivers and were less likely to be agitated.

Frequent loss of heterozygosity at 1p36.3 and p73 abnormality in parathyroid adenomas

Although 1p is one of the most common loci showing loss of heterozygosity (LOH) in primary parathyroid adenoma, fine mapping has not been previously examined. In this study, we analyzed LOH in 32 primary parathyroid adenomas using five microsatellite markers at 1p36 (proximal-D1S507-D1S450-D1S2893-D1S468-D1S243-distal). All cases were heterozygous for at least one marker. The frequency of LOH varied from 41.2% (D1S468) to 7.1% (D1S507) among the different markers. LOH was detected consistently in a group of nine adenomas (28.1%, 9/32). A single region (7 cM) showing a consistent LOH at 1p36.3 was obtained that was flanked distally by D1S468 and proximally by D1S2893. Because the p73 gene is localized within this region and acts as a tumor suppressor gene, we examined the possible involvement of p73 in the development of parathyroid tumor. Allelic loss of p73 was identified in four adenomas (25%, 4/16 informative cases) that were all from the group of the nine adenomas with LOH, but somatic mutation was not detected in the remaining allele. At the StyI polymorphism of Exon 2, four of the six adenomas with LOH at 1p36 were heterozygous and expressed the GC allele. Of the six heterozygous adenomas without LOH, 4 showed biallelic and 2 monoallelic expressions (GC allele). All adenomas mainly expressed the p73alpha isoform. p73 protein was observed in five of the six adenomas with LOH and in two of the six adenomas without LOH. There were no differences in p73 protein levels between the samples with and without LOH. In conclusion, a candidate gene for parathyroid tumorigenesis is present within a 7-cM region at 1p36.3, however p73 is unlikely to be the target of the LOH at 1p36.3.

Stable histone deacetylase complexes distinguished by the presence of SANT domain proteins CoREST/kiaa0071 and Mta-L1

Human histone deacetylases I (HDAC1) and II (HDAC2) are homologous proteins (84% identity) that catalyze release of acetyl groups from modified N-terminal lysines of core histones. Histone deacetylation is correlated with both transient and persistent states of transcriptional inactivity (i.e. silencing) in many eukaryotes. In this study, we analyzed complexes containing HDAC1 and HDAC2 to identify the proteins most stably associated with these deacetylases. Complex cI (9.5 S) contained transcriptional corepressor CoREST/kiaa0071 and a protein homologous to FAD-dependent oxidoreductases, kiaa0601. Complex cII (15 S) contained >/=15 proteins, including CHD3/4 (Mi-2), Mta-L1, RbAp48/46, and MBD3, characteristic of vertebrate nucleosome-remodeling complexes. Under native conditions, cI and cII may contain HDAC1, HDAC2 or both; these can be dissociated to cI and cII core complexes containing only HDAC1 or HDAC2. The (m)CpG-binding protein MBD2 was associated only with the HDAC1 cII core complex. A model is proposed in which HDAC1 core complexes can be targeted to methylated DNA via MBD2 with recruitment of HDAC2 occurring through formation of HDAC1/2 cII dimers. We note that the cI component CoREST/kiaa0071 and the cII component Mta-L1 share a region of homology that includes a SANT domain; this domain may play a role in complex assembly.

Low-grade pulmonary myxoid sarcoma of uncertain histogenesis

The present report describes an unusual case of low-grade pulmonary sarcoma with extensive myxoid change in a 60-year-old man. During 30 months, the tumor enlarged gradually and thereafter rapidly to 9 cm. Preoperative biopsy and cytology gave negative results. The resected mass, located at the periphery of the right upper lobe, was well circumscribed and showed gelatinous without necrosis or hemorrhage. Histologically, the tumor was composed of slightly atypical, spindle-shaped or stellate cells, which were loosely distributed within a prominent myxoid stroma. Epithelial differentiation was not seen. Lacunar structures were occasionally evident, but no cartilaginous matrix was seen. Mitotic figures were infrequent. Immunohistochemistry failed to clarify the nature of the neoplastic cells except vimentin positivity. Histochemically, the myxoid ground substance was composed of hyaluronic acid and acid mucopolysaccharide. Electron microscopy revealed no specific differentiation other than aggregates of filaments, which were seen in a number of neoplastic cells. Flow cytometric analysis of the neoplastic cells revealed a diploid pattern. These findings indicated that the neoplasm was a low-grade myxoid sarcoma; however, a definite diagnosis could not be made. The tumor might have been a variant of extraskeletal myxoid chondrosarcoma, especially considering the histochemical results.

Chromophobe renal cell carcinoma with sarcomatoid change. A case report

Chromophobe renal cell carcinoma (RCC) is a newly established entity of renal neoplasm with histological and molecular biological features different from those of common RCCs. Chromophobe RCC shows characteristically cloudy and reticular cytoplasm and cellular features resembling distal nephron. Its prognosis has been reported to be more favorable than that of common RCCs. Recently, however, several cases have been reported which showed sarcomatoid change to present poor prognosis. Here we present a case of chromophobe RCC with sarcomatoid change which was once resected surgically. The surgically resected tumor was histologically composed of chromophobe epithelial cell sheets and sarcomatoid elements. The former showed positivity for colloid iron staining, and was immunohistochemically positive for E-cadherin and epithelial membrane antigen (EMA), whereas the latter was positive for vimentin instead of colloid iron and E-cadherin. EMA was focally positive in the sarcomatoid element. The patient died with systemic metastases 14 months after the operation. Histologically, the metastatic tumors were composed only of sarcomatoid element lacking epithelial element. Based on these findings and previous reports, this case supports the existence of a tumor progression pathway from chromophobe to sarcomatoid RCC. It is necessary to perform careful postoperative investigation of chromophobe RCC due to its possible histological progression to the sarcomatoid subtype.

PTEN/MMAC1/TEP1 mutations in human primary renal-cell carcinomas and renal carcinoma cell lines

Extensive allelotyping studies have implicated several tumor-suppressor loci on chromosomes 3p, 5q, 6q, 8p, 9pq, 10q, 11q, 14q, 17p, 18q and 19p in human kidney tumorigenesis. The PTEN (also called MMAC1 and TEP1) gene, a candidate tumor suppressor located at chromosome 10q23.3, is mutated in a variety of sporadic malignancies as well as in patients with Cowden disease. To investigate the potential role of the PTEN gene in renal tumorigenesis, we searched for abnormalities of the gene in 68 primary renal-cell carcinomas (RCCs) as well as in 17 renal carcinoma-derived cell lines, using DNA-SSCP, sequencing and microsatellite analysis. Five of 68 (7.5%) primary RCCs exhibited intragenic mutations (3 missense, 1 deletion and 1 splice-site), and 1 of 17 (5.9%) cell lines had an insertion mutation. Loss of heterozygosity of the PTEN gene occurred in 25% of primary RCCs, including the 3 cases with intragenic mutation and the 1 PTEN-mutated cell line. Clinical and histopathological examinations revealed that 4 of the 5 primary tumors with PTEN mutation were high-grade, advanced clear-cell RCCs with distant metastases or renal vein tumor invasions, resulting in poor prognostic courses. The other was a low-stage papillary/chromophilic RCC. Our data suggest that PTEN mutation is observed in a subset of RCCs and that, especially in clear-cell RCCs, it occurs as a late-stage event and may contribute to the invasive and/or metastatic tumor phenotype.

Endotoxin clearance and its relation to hepatic and renal disturbances in rats with liver cirrhosis

BACKGROUND/AIMS

Little is known about endotoxin clearance and secretion of cytokines from macrophages in liver cirrhosis. The aims of this study were to investigate the relationship of endotoxin clearance and release of tumor necrosis factor alpha by various macrophages to hepatic and renal disturbances in liver cirrhosis.

METHODS

Male Sprague-Dawley rats were given 0.04% thioacetamide orally for 6 or 12 months. The organ distribution of infused [3H]-endotoxin (10 microg/kg b.w.) was analyzed at 30 min or at 24 h. Uptake of [3H]-endotoxin and secretion of tumor necrosis factor alpha by Kupffer cells, splenic macrophages and peripheral blood monocytes (1 x 10(4) cells/ml) from cirrhotic and control rats were determined.

RESULTS

In cirrhotic rats, more endotoxin was left in the body and more endotoxin accumulated in the spleen and kidney, and thus was related to elevation of serum total bilirubin, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine and tumor necrosis factor alpha. Endotoxin uptake and tumor necrosis factor alpha release by the Kupffer cells were decreased and those by the splenic macrophages and peripheral blood monocytes were increased in cirrhotic rats.

CONCLUSIONS

In liver cirrhosis, impaired clearance of endotoxin together with increased secretion of tumor necrosis factor alpha by extrahepatic macrophages may play an important role in the progression of hepatic and renal disturbances.

Histone acetylases--versatile players

Genomic DNA in eukaryotes is tightly packed in the form of a highly ordered chromatin structure. In view of this tight packing, one of the most important questions in biology is how the transcriptional machinery regulates target genes in chromatin. Reversible modification of histones by acetylation is involved in transcriptional activation as well as repression in chromatin contexts. Recent studies with highly purified histone acetylases have provided insights into the mechanisms whereby acetylases contribute to transcriptional control. Furthermore, they suggest the possibility that histone acetylases could play roles in various forms of DNA metabolism as well as in transcription in chromatin contexts.

PTEN/MMAC1/TEP1 mutations in human primary renal-cell carcinomas and renal carcinoma cell lines

Extensive allelotyping studies have implicated several tumor-suppressor loci on chromosomes 3p, 5q, 6q, 8p, 9pq, 10q, 11q, 14q, 17p, 18q and 19p in human kidney tumorigenesis. The PTEN (also called MMAC1 and TEP1) gene, a candidate tumor suppressor located at chromosome 10q23.3, is mutated in a variety of sporadic malignancies as well as in patients with Cowden disease. To investigate the potential role of the PTEN gene in renal tumorigenesis, we searched for abnormalities of the gene in 68 primary renal-cell carcinomas (RCCs) as well as in 17 renal carcinoma-derived cell lines, using DNA-SSCP, sequencing and microsatellite analysis. Five of 68 (7.5%) primary RCCs exhibited intragenic mutations (3 missense, 1 deletion and 1 splice-site), and 1 of 17 (5.9%) cell lines had an insertion mutation. Loss of heterozygosity of the PTEN gene occurred in 25% of primary RCCs, including the 3 cases with intragenic mutation and the 1 PTEN-mutated cell line. Clinical and histopathological examinations revealed that 4 of the 5 primary tumors with PTEN mutation were high-grade, advanced clear-cell RCCs with distant metastases or renal vein tumor invasions, resulting in poor prognostic courses. The other was a low-stage papillary/chromophilic RCC. Our data suggest that PTEN mutation is observed in a subset of RCCs and that, especially in clear-cell RCCs, it occurs as a late-stage event and may contribute to the invasive and/or metastatic tumor phenotype.

Prognostic impact of plasma brain natriuretic peptide for cardiac events in elderly patients with congestive heart failure

BACKGROUND

Plasma brain natriuretic peptide (BNP) has been reported to be useful in determining the prognosis of patients with ischemic heart disease and cardiomyopathy. However, aging increases the level of plasma BNP; therefore, the prognostic impact of plasma BNP in elderly patients with congestive heart failure has not been fully established.

OBJECTIVE

We sought to determine whether plasma BNP could predict recurrent cardiac events in elderly patients with congestive heart failure.

METHODS

Forty-eight consecutive elderly patients (>65 years old) were enrolled in the present study. All patients were admitted with their first episode of congestive heart failure. Clinical characteristics, plasma BNP, left ventricular ejection fraction, and left ventricular mass index were compared between patients with and those without recurrent cardiac events.

RESULTS

During the follow-up period, twelve cardiac events were observed. The New York Heart Association functional class was signi- ficantly higher in patients with cardiac events than in those without (p < 0.05). The plasma BNP level in pa- tients with cardiac events was significantly higher than in those without (521.0 +/- 156.0 vs. 126.8 +/- 20.1 pg/ml, p<0.001), despite more frequent treatment with angiotensin-converting enzyme inhibitors (75 vs. 28%, p<0.05). The left ventricular ejection fraction was significantly lower and the left ventricular mass index higher in patients with cardiac events as compared with those without (38.1 +/- 5.0 vs. 49.2 +/- 2.4%, p < 0.05; 193.8 +/- 14.3 vs. 132.6 +/- 7.8 g/m(2), p < 0.001, respectively). The plasma BNP was selected as an independent factor associated with cardiac events besides New York Heart Association functional class, left ventricular ejection fraction, and left ventricular mass index using multivariate Cox proportional-hazards regression analysis (hazard ratio = 2.656, p<0.05). The cardiac event rate was significantly higher in patients with a plasma BNP concentration >132 pg/ml using Kaplan-Meier analysis (p < 0.001). Moreover, the plasma BNP level correlated inversely with the length of time from hospital discharge to a cardiac event (r = -0.575, p<0.05).

CONCLUSION

Measuring the plasma BNP level before hospital discharge in elderly patients with congestive heart failure was more useful than other conventional examinations for predicting the recurrence of cardiac events.

Augmented hepatocellular carcinoma progression and depressed Kupffer cell activity in rat cirrhotic livers

To examine the property of hepatocellular carcinoma (HCC), rat HCC cells were implanted into normal and cirrhotic rat livers. Implanted HCC grew much more progressively in cirrhotic livers than in normal livers. Kupffer cells were decreased profoundly in cirrhotic livers, resulting in markedly impaired phagocytic activity. Furthermore, production of Kupffer cell-related cytokines, such as interleukin-1 beta and tumor necrosis factor-alpha, was decreased profoundly in cirrhotic livers. Our results indicate that liver cirrhosis is a prominent promoting factor in HCC progression, and that markedly depressed Kupffer cell activity may play a role in augmented HCC progression in cirrhotic livers.

Hepatic adenomas treated with percutaneous ethanol injection in a patient with glycogen storage disease type Ia

We report a 20-year-old man with glycogen storage disease type Ia (GSD Ia) who presented multiple hepatocellular adenomas (HCAs) in 1993 and in whom percutaneous ethanol injection (PEI) was conducted as treatment for some enlarging tumors beneath the liver surface. In a 6-year follow-up period, we observed gradual enlargement of some of the HCAs, and the rapid growth of a newly developed tumor. In August 1996, one slow-growth HCA was 52 mm in diameter and was located beneath the surface of the liver. We conducted PEI therapy to prevent its spontaneous rupture. During the following year, another tumor developed beneath the liver surface, but showed extremely rapid growth, reaching 51 mm in diameter, from being undetectable, within 12 months. PEI therapy was again conducted for this newly developed tumor. Although additional PEI therapy was required for each tumor, because of suspected recurrence, no findings of discrete recurrence have been detected by computed tomography and magnetic resonance imaging for more than 2 years, up to the time of this study. We consider PEI to be a useful and effective therapeutic modality for individual HCAs in patients with GSD Ia.

[Factors leading to home care of patients in the terminal stage of malignant diseases--a study of 10 cases]

In order to clarify the factors that lead patients in the terminal stage of malignant diseases to home care, we interviewed ten families of such patients. Among factors involving patients, a strong desire to stay at home and to spend time at home with the family were initially required. Adequate understanding of the patients and their diseases was also needed by families. Other factors include guaranteed medical services in emergencies and/or 24 hours/day 7 days/week care. Patients requested referrals to family physicians, visiting nurses or community health services to cover outpatient clinic functions. It is concluded that a strong desire to stay at home, adequate understanding by the family and guaranteed medical services in emergencies were three significant factors leading to home care of patients in the terminal stage of malignant diseases.

Reminiscence therapy using odor in alcohol-dependent patients--psychophysiological evaluation and psychological evaluation; power spectral analysis of heart rate variability

OBJECTIVE

This research was based on the hypothesis that when alcohol-dependent patients describe themselves, awakening of emotion by affirmative odor stimulation may facilitate memory reframing focusing on more affirmative emotion and memories. To prove the hypothesis, physiological changes accompanied by emotional awakening were evaluated by measuring the autonomic activity. In addition, subjective evaluation by a self-report manner was examined to investigate the effectiveness of Reminiscence Therapy (RT) using odor in alcohol-dependent patients.

SUBJECTS

Thirty-four patients who met the DSM-IV criteria of alcohol-related disorders and were hospitalized in a ward specialized to alcohol dependence therapy.

METHODS

Each patient underwent a one-to-one interview twice. For counterbalance, one interview was performed with odor stimulation using an odor with a relaxing effect that recall pleasant emotion, and the other was without odor stimulation. As the evaluation indices of physiological changes accompanied by emotional awakening, index of autonomic function (HRV; Heart rate variability) for objective evaluation and psychological indices (STAI; State-Trait Anxiety Inventory VAS; Visual Analog Scale) for subjective evaluation were measured.

RESULTS

1) Objective evaluation: Regarding the evaluation index of the autonomic function, the sympathetic nervous system activity (LF/HF; low frequency component/high frequency component ratio) was significantly inhibited by odor stimulation (p < 0.05). 2) Subjective evaluation: Compared to the state prior to interview, state anxiety judged by STAI was significantly decreased after interview (p < 0.01). The VAS score was significantly decreased after interview regardless of the presence or absence of odor stimulation (p < 0.0001).

CONCLUSIONS

A reduction in state anxiety was observed. The effect of odor was not significant on the subjective evaluation, but the objective evaluation suggested that the odor inhibited the sympathetic nervous system. Thus, it was suggested that odor can be used in RT, that is, emotional changes due to stimulation of odor may be applicable in RT.

Cellular components that functionally interact with signaling phospholipase A(2)s

Accumulating evidence has suggested that cytosolic phospholipase A(2) (cPLA(2)) and several secretory PLA(2) (sPLA(2)) isozymes are signaling PLA(2)s that are functionally coupled with downstream cyclooxygenase (COX) isozymes for prostaglandin (PG) biosynthesis. Arachidonic acid (AA) released by cPLA(2) and sPLA(2)s is supplied to both COX-1 and COX-2 in the immediate, and predominantly to COX-2 in the delayed, PG-biosynthetic responses. Vimentin, an intermediate filament component, acts as a functional perinuclear adapter for cPLA(2), in which the C2 domain of cPLA(2) associates with the head domain of vimentin in a Ca(2+)-sensitive manner. The heparin-binding signaling sPLA(2)-IIA, IID and V bind the glycosylphosphatidylinositol-anchored heparan sulfate proteoglycan glypican, which plays a role in sorting of these isozymes into caveolae and perinuclear compartments. Phospholipid scramblase, which facilitates transbilayer movement of anionic phospholipids, renders the cellular membranes more susceptible to signaling sPLA(2)s. There is functional cooperation between cPLA(2) and signaling sPLA(2)s in that prior activation of cPLA(2) is required for the signaling sPLA(2)s to act properly. cPLA(2)-derived AA is oxidized by 12/15-lipoxygenase, the products of which not only augment the induction of sPLA(2) expression, but also cause membrane perturbation, leading to increased cellular susceptibility to the signaling sPLA(2)s. sPLA(2)-X, a heparin-non-binding sPLA(2) isozyme, is capable of releasing AA from intact cells in the absence of cofactors. This property is attributed to its ability to avidly hydrolyze zwitterionic phosphatidylcholine, a major phospholipid in the outer plasma membrane. sPLA(2)-V can also utilize this route in several cell types. Taken together, the AA-releasing function of sPLA(2)s depends on the presence of regulatory cofactors and interfacial binding to membrane phospholipids, which differ according to cell type, stimuli, secretory processes, and subcellular distributions.

Reduced expression of p27/Kip1 is associated with the development of pulmonary adenocarcinoma

p27/Kip1 (p27), a negative regulator of cell proliferation, is a powerful prognostic marker in non-small cell lung carcinoma. To clarify the significance of p27 aberrations in the tumourigenesis of lung adenocarcinoma, p27 expression was investigated by immunohistochemistry in lung adenocarcinoma and its precursor lesion, atypical adenomatous hyperplasia (AAH), and correlated with the expression of Ki-67, cyclin D1, and cyclin E. The p27 labelling index decreased in parallel with tumour progression (24.0% to 4.5%) and was found to be lower in neoplastic lesions than in normal bronchiolar epithelial cells (48.8%). There was a negative correlation between p27 and Ki-67 expression (rho=-0.384, p<0.001). Cyclin E-positive lesions (with labelling index >/=5%) were found only in overt adenocarcinomas. The Ki-67 labelling index of cyclin E-positive, high (>/=10%) p27 expressers was lower than that of cyclin E-positive, low (<10%) p27 expressers (16.8% vs. 42.6%; p=0. 046) and was similar to that of cyclin E-negative adenocarcinomas (15.0%). These results indicate that reduced p27 expression is associated with and may play a role in progression during the development of pulmonary adenocarcinoma.

QT dispersion is increased in diabetic patients with foot ulcer

QT dispersion, a measure of inhomogenous ventricular repolarization, was measured in diabetic patients with foot ulcer. We recruited 75 patients with non insulin-dependent diabetes mellitus: patients with neuropathic ulcer (n=15, NU group), with ischemic ulcer (n=20, IU group), with previous myocardial infarction (n=20, MI group) and without any diabetic microangiopathies (n=20, DC group). We also studied normal control subjects (n=15, NC group). The interlead variability of rate corrected QT interval (QTc dispersion) was calculated. QTc interval in the MI group was significantly higher than that in the NC or DC but showed no difference in the NU and IU groups. QTc dispersion in the IU (54+/-15 msec) as well as MI (60+/-21 msec) group were significantly higher than the NC (36+/-18 msec) or DC group (39+/-14 msec). This may be due to complicated coronary artery disease in the IU group. Furthermore, QTc dispersion was also increased (49+/-14 msec) in the NU group in which cardiac autonomic nervous dysfunction was suggested. Patients with both types of diabetic ulcer demonstrated increased QT dispersion due to atherosclerosis or neurological disorder.

Molecular identification of cytosolic prostaglandin E2 synthase that is functionally coupled with cyclooxygenase-1 in immediate prostaglandin E2 biosynthesis

Here we report the molecular identification of cytosolic glutathione (GSH)-dependent prostaglandin (PG) E(2) synthase (cPGES), a terminal enzyme of the cyclooxygenase (COX)-1-mediated PGE(2) biosynthetic pathway. GSH-dependent PGES activity in the cytosol of rat brains, but not of other tissues, increased 3-fold after lipopolysaccharide (LPS) challenge. Peptide microsequencing of purified enzyme revealed that it was identical to p23, which is reportedly the weakly bound component of the steroid hormone receptor/hsp90 complex. Recombinant p23 expressed in Escherichia coli and 293 cells exhibited all the features of PGES activity detected in rat brain cytosol. A tyrosine residue near the N terminus (Tyr(9)), which is known to be critical for the activity of cytosolic GSH S-transferases, was essential for PGES activity. The expression of cPGES/p23 was constitutive and was unaltered by proinflammatory stimuli in various cells and tissues, except that it was increased significantly in rat brain after LPS treatment. cPGES/p23 was functionally linked with COX-1 in marked preference to COX-2 to produce PGE(2) from exogenous and endogenous arachidonic acid, the latter being supplied by cytosolic phospholipase A(2) in the immediate response. Thus, functional coupling between COX-1 and cPGES/p23 may contribute to production of the PGE(2) that plays a role in maintenance of tissue homeostasis.

Regulation of prostaglandin E2 biosynthesis by inducible membrane-associated prostaglandin E2 synthase that acts in concert with cyclooxygenase-2

Here we report the molecular identification of membrane-bound glutathione (GSH)-dependent prostaglandin (PG) E(2) synthase (mPGES), a terminal enzyme of the cyclooxygenase (COX)-2-mediated PGE(2) biosynthetic pathway. The activity of mPGES was increased markedly in macrophages and osteoblasts following proinflammatory stimuli. cDNA for mouse and rat mPGESs encoded functional proteins that showed high homology with the human ortholog (microsomal glutathione S-transferase-like 1). mPGES expression was markedly induced by proinflammatory stimuli in various tissues and cells and was down-regulated by dexamethasone, accompanied by changes in COX-2 expression and delayed PGE(2) generation. Arg(110), a residue well conserved in the microsomal GSH S-transferase family, was essential for catalytic function. mPGES was functionally coupled with COX-2 in marked preference to COX-1, particularly when the supply of arachidonic acid was limited. Increased supply of arachidonic acid by explosive activation of cytosolic phospholipase A(2) allowed mPGES to be coupled with COX-1. mPGES colocalized with both COX isozymes in the perinuclear envelope. Moreover, cells stably cotransfected with COX-2 and mPGES grew faster, were highly aggregated, and exhibited aberrant morphology. Thus, COX-2 and mPGES are essential components for delayed PGE(2) biosynthesis, which may be linked to inflammation, fever, osteogenesis, and even cancer.

Distinct but overlapping roles of histone acetylase PCAF and of the closely related PCAF-B/GCN5 in mouse embryogenesis

PCAF plays a role in transcriptional activation, cell-cycle arrest, and cell differentiation in cultured cells. PCAF contributes to transcriptional activation by acetylating chromatin and transcription factors through its intrinsic histone acetylase activity. In this report, we present evidence for the in vivo function of PCAF and the closely related PCAF-B/GCN5. Mice lacking PCAF are developmentally normal without a distinct phenotype. In PCAF null-zygous mice, protein levels of PCAF-B/GCN5 are drastically elevated in lung and liver, where PCAF is abundantly expressed in wild-type mice, suggesting that PCAF-B/GCN5 functionally compensates for PCAF. In contrast, animals lacking PCAF-B/GCN5 die between days 9.5 and 11.5 of gestation. Normally, PCAF-B/GCN5 mRNA is expressed at high levels already by day 8, whereas PCAF mRNA is first detected on day 12.5, which may explain, in part, the distinct knockout phenotypes. These results provide evidence that PCAF and PCAF-B/GCN5 play distinct but functionally overlapping roles in embryogenesis.

Studies on a mechanism by which cytosolic phospholipase A2 regulates the expression and function of type IIA secretory phospholipase A2

Although it has been proposed that arachidonate release by several secretory phospholipase A2 (sPLA2) isozymes is modulated by cytosolic PLA2 (cPLA2), the cellular component(s) that intermediates between these two signaling PLA2s remains unknown. Here we provide evidence that 12- or 15-lipoxygenase (12/15-LOX), which lies downstream of cPLA2, plays a pivotal role in cytokine-induced gene expression and function of sPLA2-IIA. The sPLA2-IIA expression and associated PGE2 generation induced by cytokines in rat fibroblastic 3Y1 cells were markedly attenuated by antioxidants that possess 12/15-LOX inhibitory activity. 3Y1 cells expressed 12/15-LOX endogenously, and forcible overexpression of 12/15-LOX in these cells greatly enhanced cytokine-induced expression of sPLA2-IIA, with a concomitant increase in delayed PG generation. Moreover, studies using 293 cells stably transfected with sPLA2-IIA revealed that stimulus-dependent hydrolysis of membrane phospholipids by sPLA2-IIA was enhanced by overexpression of 12/15-LOX. These results indicate that the product(s) generated by the cPLA2-12/15-LOX pathway following cell activation may play two roles: enhancement of sPLA2-IIA gene expression and membrane sensitization that leads to accelerated sPLA2-IIA-mediated hydrolysis.

Giant vesicles from 72-membered macrocyclic archaeal phospholipid analogues: initiation of vesicle formation by molecular recognition between membrane components

Stereochemically pure archeal acyclic bola-amphiphilic diphosphates 4 and 5, with the basic structure of the phospholipids found in Sulfolobus, have been synthesized for the first time. The self-assembly properties have been compared with those of the nearly identical 72-membered macrocyclic tetraether phosphates 3a and 3b, analogues of the major phospholipid components of Sulfolobus, Thermoplasma, and methanogenic Archea, which were also synthesized. Phase contrast and fluorescence microscopies have shown that the dipolar lipids 1 and 2 spontaneously formed vesicles. Whereas the macrocyclic dipolar phosphates 3 spontaneously formed vesicles (phase contrast and fluorescence microscopies), the bolaform phosphate 4 gave only a lamellar structure (synchrotron diffraction pattern: repeat distance of about 4.25 nm but with only a few layers). However, upon addition of the unphosphorylated precursors phytanol, phytol, or geranylgeraniol to the acyclic lipids 4 and 5, giant vesicles were rapidly formed. Addition of n-hexadecanol or cholesterol did not lead to vesicle formation. Therefore it was concluded that this vesicle formation occurs only when the added molecule is closely compatible with the constituents of the lipid layer and can be inserted into the double layer. A slight mismatch (cholesterol or n-hexadecanol/polyprenyl chains) is therefore enough to block the insertion process presumably required for vesicle formation.

Interstitial pneumonia in Hermansky-Pudlak syndrome: significance of florid foamy swelling/degeneration (giant lamellar body degeneration) of type-2 pneumocytes

Although usual interstitial pneumonia (UIP)-like IP has been known as the most serious complication of Hermansky-Pudlak syndrome (HPS), its pathologic features and pathogenesis are poorly understood. We investigated biopsied and autopsied lung tissues from five patients who died of UIP-like IP associated with HPS (HPSIP). The salient histopathologic features of HPSIP observed were: (1) alveolar septa displaying florid proliferation of type-2 pneumocytes (2PCs) with characteristic foamy swelling/degeneration; (2) patchy fibrosis with lymphocytic and histiocytic infiltration centered around respiratory bronchioles, occasionally showing constrictive bronchiolitis; and (3) honeycomb change without predilection for the lower lobes or subpleural area. Those peculiar 2PCs were histochemically characterized by the over accumulation of phospholipid, immunohistochemically by a weak positivity for surfactant protein, and ultrastructurally by the presence of numerous giant lamellar bodies that compressed the nucleus with occasional cytoplasmic disruption, together suggesting a form of cellular degeneration with an over accumulation of surfactant (giant lamellar body degeneration). The present study strongly indicates that there is a basic defect in the formation/secretion process of surfactant by the 2PCs in HPS, which may well be the triggering factor for the HPSIP development. Other factors, such as macrophage dysfunction, may be working synergistically for further acceleration of the inflammatory process.

Reduced expression of p27/Kip1 is associated with the development of pulmonary adenocarcinoma

p27/Kip1 (p27), a negative regulator of cell proliferation, is a powerful prognostic marker in non-small cell lung carcinoma. To clarify the significance of p27 aberrations in the tumourigenesis of lung adenocarcinoma, p27 expression was investigated by immunohistochemistry in lung adenocarcinoma and its precursor lesion, atypical adenomatous hyperplasia (AAH), and correlated with the expression of Ki-67, cyclin D1, and cyclin E. The p27 labelling index decreased in parallel with tumour progression (24.0% to 4.5%) and was found to be lower in neoplastic lesions than in normal bronchiolar epithelial cells (48.8%). There was a negative correlation between p27 and Ki-67 expression (rho=-0.384, p<0.001). Cyclin E-positive lesions (with labelling index >/=5%) were found only in overt adenocarcinomas. The Ki-67 labelling index of cyclin E-positive, high (>/=10%) p27 expressers was lower than that of cyclin E-positive, low (<10%) p27 expressers (16.8% vs. 42.6%; p=0. 046) and was similar to that of cyclin E-negative adenocarcinomas (15.0%). These results indicate that reduced p27 expression is associated with and may play a role in progression during the development of pulmonary adenocarcinoma.