Proliferating Cell Nuclear Antigen Labeling Research Articles

Proliferating Cell Nuclear Antigen Expression in Odontogenic Cysts and Ameloblastomas

Objective: To evaluate the proliferative activity of odontogenic cysts and ameloblastomas.Patients and Methods: Ten radicular cysts, 10 dentigerous cysts, 10 odontogenic keratocysts, 14 ameloblastomas, 5 unicystic ameloblastomas, and 9 recurrent ameloblastomas were immunohistologically stained with antibody to proliferating cell nuclear antigen. Immunoreactivity was evaluated by counting cells.Results: Odontogenic keratocysts elicited the highest proliferating cell nuclear antigen labelling index within the odontogenic cyst group. Most of the proliferating cell nuclear antigen-positive cells were predominantly found in the suprabasal region of odontogenic keratocysts. Odontogenic keratocysts demonstrated a significantly higher proliferating cell nuclear antigen labelling index than radicular cysts (p < 0.05), but not higher than dentigerous cysts. In the ameloblastoma group, proliferating cell nuclear antigen-positive cells were preferentially located at the periphery of the ameloblastic islands. Recurrent ameloblastomas showed the highest proliferating cell nuclear antigen labelling index, while unicystic ameloblastomas showed the lowest labelling index. The differences in the proliferating cell nuclear antigen labelling index between recurrent ameloblastomas and the other ameloblastoma groups were not statistically significant.Conclusions: The proliferating cell nuclear antigen labelling index correlated well with the biological behaviour of odontogenic cysts and ameloblastomas, and may be useful as a marker to predict the clinical behaviour of odontogenic lesions.

Clinicopathological Profile of Oral Soft Tissue Sarcoma

Objective: To ascertain the clinicopathological profile of oral soft tissue sarcoma.Patients and Methods: Between 1980 and 2000, twelve patients with oral soft tissue sarcoma were evaluated for the expression profile of tumour suppression gene products (p53, pRB, p16) proliferating cell nuclear antigen labelling index; invasive and metastatic potential by matrix metalloproteinase expression; and intratumoural microvessel density.Results: Oral soft tissue sarcomas generally presented as asymptomatic masses. All patients were treated by surgery except for 2 who had distant metastasis at presentation. Local recurrences after surgery were observed in 6 of the 10 operated patients (60.0%), and distant metastasis occurred in 7 of 12 patients (58.3%). Nine patients (75.0%) died despite treatment. In immunohistochemical studies, overexpression of p53 was noted in 6 of the 10 operated patients (60.0%) and loss of p16 expression was noted in 8 patients (80.0%). The mean proliferating cell nuclear antigen labelling index was 31.4%. Matrix metalloproteinase-2 and matrix metalloproteinase-9 expression was observed in all patients and the tumours showed low intratumoural microvessel density (mean, 4.5 per examination area).Conclusion: These observations illustrate the well-recognised high proliferative potential and aggressiveness without angiogenesis of oral soft tissue sarcomas.

Balance between pro and anti-inflammatory cytokines in patients with acute alcoholic hepatitis

The ability of endogenous IL-10 to modulate inflammatory response and to limit hepatotoxicity has been shown in several models of liver injury. The objectives of this study were to evaluate the relationship between liver disease and the balance between pro and anti-inflammatory cytokines in acute alcoholic hepatitis. Twenty-five patients with pure steatosis, 17 with cirrhosis and mild acute alcoholic hepatitis (discriminant function value<32) and 41 patients with cirrhosis and severe acute alcoholic hepatitis (discriminant function value >=32) were studied. Plasma levels of interleukin 10 (IL-10) and soluble TNF receptors (TNFsRp75 and 55) were analyzed using ELISA assays. Hepatocyte proliferative activity was assessed with proliferating cell nuclear antigen labeling index (PCNA-LI) on formalin-fixed paraffin embedded liver biopsy specimens. In patients with steatosis, cirrhosis with mild and severe acute alcoholic hepatitis, the plasma levels of IL-10 were higher (P<0.05) than in healthy controls. Between day 1 and day 8, the TNFsRp55/IL-10 ratio increased by 137 +/- 47 in the 10 patients with severe acute alcoholic hepatitis treated with prednisolone who died within 2 months and by 9.3 +/- 14 in the 19 patients still alive at 2 months (P=0.031). In patients with severe acute alcoholic hepatitis, PCNA-LI on liver biopsy was negatively correlated with the TNFsRp55/IL-10 ratio increase from day 1 to day 8 (r=- 0.42, P=0.11). PCNA-LI was positively correlated with TNFsRp75/TNFsRp 55 ratio increase from day 1 to day 15 (r=0.52; p<0.05). Our data suggest the anti-inflammatory system is up-regulated in patients with alcoholic liver disease. Nevertheless, in patients with severe acute alcoholic hepatitis, IL-10 production seems insufficient to modulate TNF-alpha cytotoxicity mediated by TNFRp55.

Regeneration of Tubular Complex Is Promoted by a Free Space

Regeneration of the pancreas is initiated by the tubular complexes that consist of a cluster of epithelia surrounded by the mesenchymal cells. They have the potential to become pancreatic lobes, but their growth stops before the complete regeneration of the organ. To elucidate the possibility that we could promote the regeneration of the pancreas, the potential for growth or differentiation of tubular complex was analyzed. The intact lobes were growing around the silk knot after ligation of the pancreas in adult mice. To develop this reaction to a quantitative assay, tubular complexes were induced on the silk strings in the pancreas and were growing into a free space under the silicon cover. The proliferation and differentiation of new lobes with or without the space were analyzed. The number of tubular complexes, which express PDX-1, was increased 5.4 times by the space effect. The proliferating cell nuclear antigen labeling index of acinar cells was 1.7 times stimulated, but that of tubular complex was not changed. The amputated pancreas recovered 49.5% of the resected part under the silicon cover; however, it remained the same weight without the cover. The proliferation and differentiation of tubular complex are promoted by a free space.

REG Iα protein may function as a trophic and/or anti-apoptotic factor in the development of gastric cancer

Although a significant amount of regenerating gene (REG) Ialpha protein is present not only in normal gastric mucosa but also in gastric cancer tissues, its pathophysiologic role in gastric cancer development remains unclear. We investigated REG Ialpha protein expression in early gastric cancers, and examined whether cytokines are responsible for REG Ialpha gene expression and whether REG Ialpha protein has a trophic and/or an antiapoptotic effect on gastric cancer cells. Early gastric cancer specimens were analyzed histologically using immunohistochemistry for REG Ialpha protein and proliferating cell nuclear antigen (PCNA). The effects of cytokines on REG Ialpha promoter activity and its messenger RNA (mRNA) expression in AGS (a kind of gastric cancer cell line) cells were examined by luciferase reporter assay and Northern blot analysis, respectively. Effects of REG Ialpha protein on cell growth and H2O2-induced apoptosis in AGS cells were examined by 3,-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphatase nick-end labeling (TUNEL) assays, respectively. REG Ialpha-positive early gastric cancers showed a significantly higher PCNA labeling index and more severe inflammatory cell infiltration in adjacent gastric mucosa than the negative cancers. REG Ialpha gene expression and its promoter activity were enhanced by interferon (IFN)-gamma and interleukin (IL)-6. REG Ialpha protein promoted cell growth and cell resistance to H2O2-induced apoptosis in AGS cells. These effects were abolished by concomitant treatment with anti-REG Ialpha antibody. REG Ialpha protein enhanced Akt phosphorylation and Bcl-xL expression in AGS cells. REG Ialpha gene is inducible by cytokine stimulation and its gene product may function as a mitogenic and/or an antiapoptotic factor in the development of early gastric cancer.

Proliferating‐cell nuclear antigen (PCNA) as an independent prognostic marker in patients after prostatectomy: a comparison of PCNA and Ki‐67

To investigate the prognostic value of prostatic tumour cell proliferation, as measured by Ki-67 and proliferating cell nuclear antigen (PCNA), and to compare these measures in men at low and high risk for progression of tumour. Two groups of patients with prostate cancer, i.e. 'metastatic' (M, 22) who had pT3b-4aN0M0 and pTanyN1M0, and 'nonmetastatic' (NM, 18), who had < or =pT3aN0M0 disease, were selected from a well-examined and mapped group of 114 treated by radical prostatectomy. Patients in the NM group were selected by the criteria of having a Gleason score of < or = 7. To assess proliferation, 1000 cells were counted at x 400 magnification by two observers and the percentage of tumour cells positively stained with Ki-67 and PCNA defined as the Ki-67 and PCNA labelling index (LI), respectively. The two LI were compared in the NM and M groups, and the correlation of the LIs with pathological stage, progression and prostate-specific antigen (PSA)-free survival evaluated. Prognostic values of the LI were analysed using multivariate analysis. The mean (range) follow-up was 33 (4-78) months. The mean LIs were higher in the M than the NM group for both PCNA and Ki-67 (P = 0.02 and 0.019, respectively). Both LIs were markedly different between the groups when stratified by progression, with both significantly higher in men with progression in the NM group. Both LIs had a significant association with Gleason score, pathological stage, progression and PSA-free survival. In multivariate analysis the PCNA LI, surgical margin status and pathological stage were independent factors for progression. Tumour cell proliferation as assessed by Ki-67 or PCNA correlate significantly with progression. The PCNA LI was an independent predictor of progression, especially in patients with a low risk of progression according to predefined criteria.

Role of transforming growth factor-β1 (TGF-β1) in endotoxin-induced hepatic failure after extensive hepatectomy in rats

Postoperative infections after hepatectomy sometimes lead to fatal hepatic failure, but the mechanism of the hepatic failure is unclear. Wistar rats underwent 90% hepatectomy, and were then divided into three groups: (i) the SAL group, injected with normal saline; (ii) the LPS group, injected with lipopolysaccharide (LPS) every day for 1 week; and (iii) the LPS plus TGF-Ab (LPS+TGF-Ab) group, injected with LPS with anti-transforming growth factor-β1 (TGF-β1) antibody. We investigated survival rates, TGF-β1 expression in the liver, liver regeneration by proliferating cell nuclear antigen labeling index, hepatocyte apoptosis by single stranded DNA labeling index, and perisinusoidal fibrosis using Masson's trichrome staining. The LPS group (30.4%) had a significantly lower survival rate than the SAL group (84%) and tended to be lower than the LPS+TGF-Ab group (49.4%). Liver regeneration in the LPS group was significantly lower than in the other groups. In the LPS group, hepatocyte apoptosis and perisinusoidal fibrosis was significantly more remarkable, and TGF-β1 expression was significantly higher than in the SAL group. TGF-β1 enhanced by LPS plays an important role in the mechanism of hepatic failure by infections after hepatectomy, especially in inhibition of liver regeneration, and induction of hepatocyte apoptosis and perisinusoidal fibrosis.

Role of transforming growth factor-β1 (TGF-β1) in endotoxin-induced hepatic failure after extensive hepatectomy in rats

Postoperative infections after hepatectomy sometimes lead to fatal hepatic failure, but the mechanism of the hepatic failure is unclear. Wistar rats underwent 90% hepatectomy, and were then divided into three groups: (i) the SAL group, injected with normal saline; (ii) the LPS group, injected with lipopolysaccharide (LPS) every day for 1 week; and (iii) the LPS plus TGF-Ab (LPS+TGF-Ab) group, injected with LPS with anti-transforming growth factor-beta1 (TGF-beta1) antibody. We investigated survival rates, TGF-beta1 expression in the liver, liver regeneration by proliferating cell nuclear antigen labeling index, hepatocyte apoptosis by single stranded DNA labeling index, and perisinusoidal fibrosis using Masson's trichrome staining. The LPS group (30.4%) had a significantly lower survival rate than the SAL group (84%) and tended to be lower than the LPS+TGF-Ab group (49.4%). Liver regeneration in the LPS group was significantly lower than in the other groups. In the LPS group, hepatocyte apoptosis and perisinusoidal fibrosis was significantly more remarkable, and TGF-beta1 expression was significantly higher than in the SAL group. TGF-beta1 enhanced by LPS plays an important role in the mechanism of hepatic failure by infections after hepatectomy, especially in inhibition of liver regeneration, and induction of hepatocyte apoptosis and perisinusoidal fibrosis.

Normal liver regeneration and liver cell apoptosis after partial hepatectomy in tumor necrosis factor‐α‐deficient mice

Tumor necrosis factor-alpha (TNF-alpha) is known as a proinflammatory cytokine that has been implicated as a contributing factor in a number of disease processes. TNF-alpha also influences liver repair following hepatotoxic damage, and regeneration following partial hepatectomy (PH). The aim of this study was to assess the mechanism by which TNF-alpha influences liver cell apoptosis and regeneration following PH in TNF-alpha-deficient (TNF-alpha(-/-)) mice. PH was performed in wild mice and TNF-alpha(-/-) mice. In both groups, serum alanine aminotransferase and serum total bilirubin levels comparably peaked at 6 and 48 h after PH, respectively. No differences were observed in hepatocyte proliferation, as determined by mitotic and the proliferating cell nuclear antigen labeling indices, between TNF-alpha(+/+) and TNF-alpha(-/-) mice. Few terminal deoxynucleotidyl transferase nick end-labeling-positive hepatocytes were seen in either type of mice. Nuclear factor-kappa B DNA binding activity in the remaining liver of TNF-alpha(-/-) mice after PH was similar to that of control mice. Ribonuclease protection assay showed that transforming growth factor beta1 mRNA was up-regulated comparably in the livers of the two groups, and that other cytokines were hardly seen in either. Interleukin-6/ signal transducer and activator of transcription-3-dependent pathway was not affected in TNF-alpha(-/-) mice. These findings suggest that TNF-alpha has little influence on liver regeneration and liver cell apoptosis after PH in mice.

The effect of cyclin D expression on cell proliferation in human gliomas

The expression of three cyclin D subtypes was defined immunohistochemically with cyclin D1, D2 and D3 monoclonal antibodies in 52 human glioma biopsies and eight control samples of normal brain tissue. PCNA labeling indices (LI) were used to evaluate proliferation in the glioma biopsies. LI of cyclin D1, D2 and D3 were compared with histological grade and the proliferating cell nuclear antigen (PCNA) LI. Cyclin D1 expression only was observed in normal brain tissue, but marked overexpression of cyclin D1 and cyclin D3 was observed in glioma. Cyclin D1 LI increased with malignancy, in parallel with an increase in PCNA LI. Lower expression of cyclin D2 was found in a small fraction of the gliomas, but its LI did not vary significantly with grade. Cyclin D3 was mainly expressed by malignant gliomas and was rarely observed in low-grade glioma. Cyclin D2 and D3 expression correlated with PCNA LI, but not as strongly as for cyclin D1. Expression of cyclin D1 is closely related to both the oncogenesis and progression of glioma, while cyclin D3 is associated with transformation to a malignant phenotype. Cyclin D2 is weakly expressed and shows no marked relationship with any aspect of tumorigenesis. The exact contribution of cyclin D subtypes to cell cycle progression in neoplastic and reactive cells remains to be defined.

Higher expressions of p53 and proliferating cell nuclear antigen (PCNA) in atrophic oral lichen planus and patients with areca quid chewing

The aim of the study was to examine the expressions of p53 and proliferating cell nuclear antigen (PCNA) in oral lichen planus (OLP) in relation to its clinical behavior and the patients' oral habits. Immunohistochemical study was carried out to investigate the expressions of p53 and PCNA in 56 OLP specimens. The results were correlated with the clinical behavior of the disease and the patients' oral habits. The expression rates were further compared with those of normal oral mucosa (NOM), epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinoma (SCC). The staining rate of p53 (28.6%) and PCNA labeling index (LI) (27.6 +/- 8.8%) in OLP were similar to those in EH ( P = .868, .074, respectively), but higher than those of NOM and lower than those of ED and SCC (all P < .05). In OLP, no significant correlations were found between p53 or PCNA expression and the patients' age, gender, lesion duration, location, size, number of site, presence of pain, presence of local irritant, and the habits of alcohol drinking and cigarette smoking (all P > .05). In addition, the mean PCNA LI of p53+ cases was close to that of p53- cases (P = .38). However, the staining rate of p53 in OLP was higher in areca quid (AQ) chewers compared to abstainers (P = .001), and the mean PCNA LI in atrophic cases was higher than that in hypertrophic cases (P = .029). Interestingly, the staining rate of p53 and mean PCNA LI were significantly increased in AQ chewers with atrophic OLP (100%, 36.7% +/- 9.0%, respectively), which were similar to those in ED and SCC (all P > .05). Although this study could not confirm the precancerous nature of OLP by the relatively low p53 and PCNA expression, the results do suggest that atrophic form OLP and patients with AQ chewing habit may have a higher disease activity in view of higher expression rates of p53 and PCNA in the lesions.

Osteopontin Expression in Proliferated Bile Ductules: The Correlation with Liver Damage in Fulminant Hepatitis

There have been many reports about the severity of hepatic necrosis caused by fulminant hepatitis; however, the relation between proliferated bile ductules and osteopontin (OPN) expression in inflamed areas in each of the clinical forms of fulminant hepatitis has not been described. To analyze the mechanism in the onset of fulminant hepatitis, we classified not only 16 autopsy cases of fulminant hepatitis into two clinical forms--acute and subacute--but also 3 autopsy cases of late-onset hepatic failure (LOHF) associated with fulminant hepatitis, and examined liver specimens by light microscopy and immunohistochemistry and also serum transaminase levels. Histopathologic study revealed that some of the proliferated bile ductules were associated directly with deteriorating hepatocytes and that bile plugs were present in the proliferated bile ductules. The value of the proliferative cell nuclear antigen labeling index (PCNA-L I) for proliferated bile ductules was very high during the acute form of fulminant hepatitis. Immunohistochemical analysis revealed that OPN expression was higher in the proliferated bile ductules of acute-form fulminant hepatitis than in cirrhotic and normal liver bile ducts. Transaminase levels in acute-form fulminant hepatitis were significantly elevated in comparison with levels in the other forms of the disease. Comparison of acute form fulminant hepatitis with the subacute form and LOHF showed OPN expression in proliferated bile ductules and serum aspartate aminotransferase (ALT)max to be decreased in the subacute form of fulminant hepatitis. OPN expression is an important marker of the degree of liver inflammation, and its regulation mechanism is very important to understanding the pathophysiology of fulminant hepatitis.

Vascular endothelial growth factor and angiopoietins regulate sinusoidal regeneration and remodeling after partial hepatectomy in rats

To study the regulatory mechanisms of sinusoidal regeneration after partial hepatectomy. We investigated the expression of angiopoietin (Ang)-1, Ang-2, Tie-2, and vascular endothelial growth factor (VEGF) in regenerating liver tissue by quantitative reverse-transcription polymerase chain reaction (RT-PCR) using a LightCycler (Roche Diagnostics) and also immunohistochemical staining after 70% hepatectomy in rats. In the next step, we isolated liver cells (hepatocytes, sinusoidal endothelial cell (SEC), Kupffer cell, and hepatic stellate cells (HSC)) from regenerating liver tissue by in situ collagenase perfusion and counterflow elutriation, to determine potential cellular sources of these angiogenic factors after hepatectomy. Proliferation and apoptosis of SECs were also evaluated by proliferating cell nuclear antigen (PCNA) staining and the terminal deoxynucleotidyl transferase d-uridine triphosphate nick end labeling (TUNEL) assay, respectively. VEGF mRNA expression increased with a peak at 72 h after hepatectomy, decreasing thereafter. The expression of Ang-1 mRNA was present at detectable levels before hepatectomy and increased slowly with a peak at 96 h. Meanwhile, Ang-2 mRNA was hardly detected before hepatectomy, but was remarkably induced at 120 and 144 h. In isolated cells, VEGF mRNA expression was found mainly in the hepatocyte fraction. Meanwhile, mRNA for Ang-1 and Ang-2 was found in the SEC and HSC fractions, but was more prominent in the latter. The PCNA labeling index of SECs increased slowly, reaching a peak at 72 h, whereas apoptotic SECs were detected between 120 h and 144 h. Ang-Tie system, together with VEGF, plays a critical role in regulating balance between SEC proliferation and apoptosis during sinusoidal regeneration after hepatectomy. However, the VEGF system plays a more important role in the early phase of sinusoidal regeneration than angiopoietin/Tie system.

Interferon-Alpha-Induced Changes in Metallothionein Expression in Liver Biopsies from Patients with Chronic Hepatitis C

An association between reactive oxygen species and liver damage has been postulated in the course of hepatitis C virus (HCV) infection. Metallothionein (MT), induced by HCV core protein and interferon (IFN), plays a role in scavenging free radicals. MT expression in liver biopsies obtained from 21 patients with chronic HCV infection before and after IFN-alpha therapy was investigated. Changes in Knodell histological activity index (HAI) scores, MT protein levels (immunohistochemistry), MT-I and MT-II messenger (m)RNA expression levels (in situ hybridization) and proliferating cell nuclear antigen (PCNA) labelling index were determined and compared in serial liver specimens. MT staining was clustered around the portal tracts with inflammatory cells and fibrosis. The pattern of MT protein before IFN-alpha therapy was similar in all patients, but was higher in IFN-sustained responders than in nonresponders after IFN-alpha therapy. HAI scores and PCNA labelling indexes were significantly reduced after IFN-alpha therapy. MT-II mRNA expression correlated positively with PCNA index before therapy and with HAI scores after therapy (P<0.05). No correlation was found between MT-I mRNA and HAI scores or PCNA index. The findings indicate that IFN-alpha-induced hepatic MT may participate in the therapeutic effects of IFN-alpha for HCV. In addition, MT-II mRNA expression may be involved in cell proliferation in the livers of patients with chronic HCV infection.

Cytologic comparison of a primary parathyroid cancer and its metastatic lesions: A case report

We describe the fine-needle aspiration cytology features of a primary parathyroid cancer and of the local recurrent and distant metastatic lesions. The presence of prognostic factors Ki-67 and proliferating cell nuclear antigen (PCNA) was compared immunohistochemically between primary parathyroid carcinoma and related metastatic and recurrent foci. Flow cytometric DNA analysis was also performed to investigate any chromosomal abnormality of the parathyroid carcinoma. Cytologic examination of the endocrine tumor showed that it comprised a loose cohesive cluster and tumor cells with granular cytoplasm and mild nuclear atypia, but for purposes of cytodiagnosis, it is difficult to determine whether such a neoplasm is malignant on the basis of morphology alone. Immunohistochemical analysis showed that Ki-67 and PCNA labeling indices were higher in the recurrent and metastasized carcinomas than in the primary cancer, suggesting that neoplastic cells become more malignant in the recurrent and metastasized foci. To our knowledge, this is the first report describing not only cytopathologic but also immunocytologic differences between primary parathyroid cancer and the metastatic lesion.

Relationship between immunohistochemical evaluation of thymidylate synthase and proliferating cell nuclear antigen labeling index in gastrointestinal carcinoma

We undertook this study to clarify the effect of immunohistochemical expression of thymidylate synthase (TS) on proliferative activity of carcinoma lesions in patients with gastrointestinal carcinoma. TS was immunohistochemically evaluated in 53 gastric carcinoma and 51 colorectal carcinoma patients using anti-TS polyclonal antibody. Proliferative activity represented by proliferating cell nuclear antigen (PCNA) labeling index (LI) was also immunohistochemically estimated using monoclonal antibody PC10. Then, the correlation between TS expression and PCNA LI was investigated. Both in gastric and colorectal carcinoma, the PCNA LIs of the high-TS group were significantly higher than those of the low-TS group. In gastric carcinoma, the PCNA LIs of the high-TS group were higher than those of the low-TS group in differentiated adenocarcinoma, in the depth of mucosal and/or submucosal layer, in cases without lymph node metastasis, and notwithstanding lymphatic or venous invasion. In colorectal carcinoma, PCNA LIs of the high-TS group were higher than those of the low-TS group in well differentiated adenocarcinoma, in the depth of serosa, in cases with lymph node metastasis, in cases with lymphatic invasion, and notwithstanding venous invasion. Immunohistochemical expression of TS was correlated with the proliferative activity represented by PCNA LI, but was not identical with PCNA LI.

Effects of TVE application during 70% hepatectomy on regeneration capacity of rats 1

For adequate control of excess bleeding during liver resection, total vascular exclusion (TVE) is preferred by surgeons, especially when the tumor is located in the posterior liver lobes or near the cava. To the authors' knowledge, the effects of TVE technique on the postoperative liver regeneration process have not thus far been evaluated yet in the literature. This study was planned to compare the effects of liver resections performed either with portal pedicle clamping or with TVE on the regeneration process. Seventy percent hepatectomy was performed with portal pedicle clamping (n=10, Group A) or with TVE (n=10, Group B) in rats. At 48 h after resection, sampling was performed for the measurement of serum transaminase, alkaline phosphatase (ALP), tissue malondialdehyde (MDA), and glutathione (GSH) levels. Liver regeneration rate, proliferating cell nuclear antigen (PCNA) labeling, and mitotic indices were also evaluated. Liver injury determinants (serum transaminases, ALP, and tissue MDA levels) were found significantly higher in group B than in group A. Liver regeneration rate, liver GSH levels, PCNA labeling index, and mitotic index were significantly lower in group B than in group A. The injury during TVE seems to be greater than during resection with portal pedicle clamping. The negative effect of this oxidative damage may influence the regenerative capacity of the remnant liver tissue.

Overexpression of extracellular signal-regulated protein kinase and its correlation with proliferation in human hepatocellular carcinoma.

Dysregulation of cell proliferation is one of the most important features of human cancers including hepatocellular carcinoma (HCC). However, the molecular basis underlying the proliferation of HCC has not been fully clarified. Because a previous study reported that overexpression of extracellular signal-regulated protein kinase (ERK), which transduces extracellular growth stimuli to the nuclei, was frequently observed in several human cancers, this study was performed to analyze the expression of ERK in human HCC and its correlation with HCC proliferation. Twenty-four paired samples of primary HCCs and corresponding noncancerous liver tissues, and six samples of histologically normal liver tissue were obtained from surgically resected materials. The expression of ERK was examined by immunoblotting and immunohistochemical analysis. Proliferative activity of each HCC was examined by immunohistochemical demonstration of proliferative cell nuclear antigen (PCNA). The ERK1 and ERK2 expression in HCCs was significantly higher than that in noncancerous liver tissues, and the ERK1 expression in noncancerous liver tissues from patients with HCC was higher than that in tissue from normal liver. Immunohistochemical examination revealed enhanced accumulation of ERK1 in the nuclei of HCC cells. Regression analysis revealed a significant correlation between ERK expression and PCNA labeling index in HCC. Our findings suggest that ERK overexpression contributes to the proliferation of HCC.

Primary pulmonary synovial sarcoma: a clinicopathologic, immunohistochemical, and molecular study of 11 cases

Primary synovial sarcoma (SS) of the lung is rare and may create diagnostic challenges. We reviewed 11 cases of pulmonary SS (PSS) confirmed by the presence of a tumor-specific SYT-SSX fusion gene to verify their clinicopathologic features including immunohistochemical and genetical profiles. The tumors occurred in 4 men and 7 women (age 29 to 81 years; mean age, 58; median age, 50), and ranged in size from 2 to 15.5 cm (mean, 9 cm). Of the 11 tumors, 10 were a monophasic fibrous type and 1 was a poorly differentiated type. Mitotic rate ranged from 8 to 43 per 10 high-power fields. All cases showed at least focal immunohistochemical positivity for AE1/AE3, CAM5.2 and/or epithelial membrane antigen. High proliferating cell nuclear antigen labeling index (>20%) was found in 8 of 10 cases (80%). Eight (90%) of 9 cases were negative for E-cadherin, and 1 case (10%) exhibited reduced expression of the molecule. The aberrant expression of β-catenin within cytoplasm and/or nuclei was observed in 6 of 9 (67%) cases. SYT-SSX1 and SYT-SSX2 fusion gene transcripts were detected in 9 and 2 cases, respectively. In 10 patients with follow-up, 3 (30%) had local recurrences, and 4 (40%) developed distant metastases. Five (50%) patients died of the tumor 1 to 9 years after surgery, and 5 (50%) were alive and disease-free in the period ranging from 3 months to 5.5 years. In conclusion, PSS tends to occur in older patients and shows an aggressive behavior probably due to its anatomical location and large tumor often resulting in incomplete resection and high proliferative activity.

Treatment results of oral verrucous carcinoma and its biological behavior

The biologic behavior of and optimal treatment for oral verrucous carcinoma (VC) remain controversial. We analyzed the clinicopathological characteristics of 12 patients with oral VC. Immunohistochemical techniques were used to evaluate p53 protein, CD44 variant 9, and proliferating cell nucleus antigen. The TNM classification (UICC, 1997) was T1 in 1 patient, T2 in 3, T3 in 4, and T4 in 4. All patients were classified as N0M0. Four patients were treated by surgery alone and 8 by surgery after chemotherapy, radiotherapy, or both. After surgery, two patients had primary recurrence of disease. Immunohistochemically, the proliferative activity of tumor cells as evaluated by proliferating cell nuclear antigen labeling index and p53 protein expression was similar in VC and well-differentiated squamous cell carcinoma. However, CD44 varient 9 expression was positive in 8 of 10 VC, suggesting that oral VC is associated with a low risk of lymph node metastasis. Positive CD44 variant 9 expression by most oral VCs, indicating a low risk of cervical lymph node metastasis, suggests that most cases can be controlled by surgical intervention.