Proliferating Cell Nuclear Antigen Labeling Research Articles

Formation of the Building Plan of the Human Heart

The intricate process of formation of the heart relies on the spatiotemporal regulation of differentiation and growth of its different parts. Errors in these processes can result in hypoplasia of the chambers and incorrect alignment of the atria and great arteries with the ventricles, with such abnormalities producing the worst forms of congenital heart disease.1 Although recent advances in molecular embryology have greatly improved our understanding of normal cardiac development, our insights into the pathogenesis of human cardiac malformations remain limited.2 With the current lack of data on gene expression in humans, inferences concerning morphogenesis rely on classic studies of human cardiac development or on extrapolation of experimental data from animal studies. Most textbooks on human embryology describe the embryonic heart tube as already possessing a linear array of the definitive components, despite this so-called segmental concept being disproved some time ago by fate-mapping experiments in chickens,3,4 which are now endorsed by recent molecular lineage analyses in mice.5 Proliferation studies in chickens revealed that the primary heart tube proliferates minimally and that its growth occurs through addition of differentiating cells from visceral mesoderm at the venous and arterial poles.6 These findings underscore previous lineage studies performed in mice, which have shown that transcription factors Islet1 and Tbx1 play a crucial role in the intricate balance between the cardiac precursor state and differentiation.7,8 Subsequent to its formation, the heart tube elongates and loops, producing its inner and outer curvatures and providing the general building plan for formation of the chambers and conduction system.9 The chambers themselves form by local proliferation and differentiation at the outer curvature.10,11 At the same time, the differentiating chamber myocardium remains flanked by primary myocardium, which is prevented from further differentiation by the …

Hyperbaric oxygenation promotes regeneration of biliary cells and improves cholestasis in rats

To investigate the effects of hyperbaric oxygenation (HBO) on regeneration of the biliary ductal system and postoperative cholestasis in hepatectomized rats. HBO was performed in Wistar rats daily starting 12 h after a 70% partial hepatectomy. Regenerated liver weight, serum parameters and the proliferating cell nuclear antigen labeling index of hepatocytes and biliary ductal cells were measured. Hepatocyte growth factor (HGF), c-Met and transforming growth factor (TGF) β-1 mRNA expression levels were analyzed by quantitative reverse transcription polymerase chain reaction. HBO improved the postoperative serum levels of total bile acid but not transaminase levels. HBO promoted hepatocyte and biliary ductal cell proliferation. The hematoxylin and eosin-stained specimens revealed fewer ballooned hepatocytes and higher cell densities in the HBO group compared to the control group. HBO suppressed c-Met mRNA levels at 15 h but did not modulate HGF or TGF β-1 mRNA expression levels. HBO promoted regeneration of biliary ductal cells and improved postoperative cholestasis after a partial hepatectomy.

Immunohistochemical detection of proliferating cell nuclear antigen in hepatocellular carcinoma.

To investigate the expression levels of proliferating cell nuclear antigen (PCNA) and its correlation with the mitotic count, histological grade, and metastasis of human hepatocellular carcinoma (HCC). PCNA expression was detected immunohistochemically with PC10 monoclonal antibody for 80 cases of HCC. The PCNA labeling index (LI) was assessed by counting the positively-stained nuclei per 500 cells. PCNA LI ranged from 1.8% to 91.4% (mean = 33.9%) in cancerous tissues, and was significantly related to the tumor size, histological grade, mitotic count and the metastases found in HCC samples. HCC Proliferation activity, as defined by PCNA immunohistochemical analysis, is strongly correlated with tumor invasiveness. These findings hold potential prognostic value for HCC patients.

Neurogenesis in the Adult Goldfish Cerebellum

Neurogenesis was studied in the cerebellum of adult goldfish, to establish the phenomenon in this popular laboratory animal model. BrdU and proliferating cell nuclear antigen labeling revealed a high rate of cell proliferation within the molecular layer of the cerebellar corpus and valve. Most newborn cells expressed the neuronal marker beta-III-tubulin after 24 hr, supporting the goldfish cerebellum as an excellent paradigm to study vertebrate adult neurogenesis.

Abstract B53: Metformin treatment suppresses colorectal aberrant crypt foci in humans: Results from a short-term feasibility study

Abstract Metformin is a biguanide derivative that has been widely used for diabetic treatment. Previously, we reported the chemopreventive effect of metformin in two rodent models of colorectal carcinogenesis. However, besides epidemiologic studies, little is known about the effects of metformin on human colorectal carcinogenesis. The objective of this pilot study was to evaluate the chemopreventive effects of metformin on rectal aberrant crypt foci (ACF), which are the endoscopic surrogate marker of colorectal cancer. We prospectively randomized 30 non-diabetic patients with ACF to treatment with metformin (250 mg/day; n = 15) or no treatment (control; n = 15); 27 patients were evaluable for endpoint analyses (12 metformin; 15 control); the two groups were similar in ACF number and other baseline clinical characteristics. Magnifying colonoscopy determined the number of rectal ACF in each patient at baseline and after 1 month in a blinded fashion (as were all laboratory-endpoint analyses). In addition, the proliferative activity of the colonic epithelium was examined by determining the proliferating cell nuclear antigen labeling index, and the apoptotic activity by terminal deoxynucleotidyl transferase dUTP nick end labeling. At 1 month, significant decrease in the mean number of ACF per person was observed in the metformin group (8.54 ± 6.37 before treatment versus 5.32 ± 4.87 at 1 month; P = 0.009), whereas in the control group the mean number of ACF did not change significantly. The proliferating cell nuclear antigen index was significantly decreased and the apoptotic cell index remained unaltered in normal rectal epithelium in metformin patients. The present study demonstrated that metformin has the potential to suppress colonic epithelial proliferation and rectal ACF formation in humans, suggesting that its promise for the chemoprevention of colorectal cancer. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B53.

Expression of α-taxilin in hepatocellular carcinoma correlates with growth activity and malignant potential of the tumor

The membrane traffic system has been recognized to be involved in carcinogenesis and tumor progression in several types of tumors. α-taxilin is a newly identified membrane traffic-related molecule, and its up-regulation has been reported in embryonic and malignant tissues of neural origin. In the present study, we analyzed the expression of α-taxilin in relation to clinicopathological features of hepatocellular carcinomas (HCC) and proliferative activity of the tumor determined by proliferating cell nuclear antigen labeling index (PCNA-LI). Twenty-nine surgically resected nodules of HCC (8 well-, 11 moderately-, and 10 poorly-differentiated) were studied. Fifteen cases showed 'strong staining', while 14 cases showed 'weak staining' for α-taxilin. A significantly higher expression of α-taxilin was observed in less-differentiated (p=0.005), and more invasive (p=0.016) HCCs. The 'strong staining' group showed significantly higher PCNA-LI than the 'weak staining' group (the medians of PCNA-LI were 59.4% vs. 14.4%, p<0.0001). We also evaluated the expression of α-taxilin in hepatoma cell lines (PLC/PRF/5, Hep G2 and HuH-6) in association with cell proliferation. The expression levels of α-taxilin protein were correlated with their growth rates. In conclusion, the expression of the α-taxilin protein was related with an increased proliferative activity and a less-differentiated histological grade of HCC. α-taxilin may be involved in cell proliferation of HCC, and its expression can be a marker of malignant potential of HCC.

Metformin Suppresses Colorectal Aberrant Crypt Foci in a Short-term Clinical Trial

The biguanide metformin is widely used for treating diabetes mellitus. We previously showed the chemopreventive effect of metformin in two rodent models of colorectal carcinogenesis. However, besides epidemiologic studies, little is known about the effects of metformin on human colorectal carcinogenesis. The objective of this pilot study was to evaluate the chemopreventive effect of metformin on rectal aberrant crypt foci (ACF), which are an endoscopic surrogate marker of colorectal cancer. We prospectively randomized 26 nondiabetic patients with ACF to treatment with metformin (250 mg/d, n = 12) or no treatment (control, n = 14); 23 patients were evaluable for end point analyses (9 metformin and 14 control); the two groups were similar in ACF number and other baseline clinical characteristics. Magnifying colonoscopy determined the number of rectal ACF in each patient at baseline and after 1 month in a blinded fashion (as were all laboratory end point analyses). We also examined proliferative activity in colonic epithelium (via proliferating cell nuclear antigen labeling index) and apoptotic activity (via terminal deoxynucleotidyl transferase dUTP nick-end labeling). At 1 month, the metformin group had a significant decrease in the mean number of ACF per patient (8.78 +/- 6.45 before treatment versus 5.11 +/- 4.99 at 1 month, P = 0.007), whereas the mean ACF number did not change significantly in the control group (7.23 +/- 6.65 versus 7.56 +/- 6.75, P = 0.609). The proliferating cell nuclear antigen index was significantly decreased and the apoptotic cell index remained unaltered in normal rectal epithelium in metformin patients. This first reported trial of metformin for inhibiting colorectal carcinogenesis in humans provides preliminary evidence that metformin suppresses colonic epithelial proliferation and rectal ACF formation in humans, suggesting its promise for the chemoprevention of colorectal cancer.

Prevention of Cutaneous Tissue Contracture During Removal of Craniofacial Implant Superstructures for CT and MRI Studies

ABSTRACTObjectivesThe purpose of this study is to analyze the morphological change of cell nuclei and the change of proliferating activity of oral malignancy and epithelial dysplasia between before and after photodynamic therapy in order to predict recurrence.Material and methodsWe experienced 14 cases of oral squamous cell carcinoma, one case of verrucous carcinoma and seven cases of epithelial dysplasia treated by photodynamic therapy (PDT). The mean nuclear area (NA) and coefficient of variation of the nuclear area (NACV) of 100 nuclei per slide were calculated using computer-assisted image analysis in hematoxylin and eosin stained biopsy specimens before and after PDT. Additionally, proliferating cell nuclear antigen (PCNA) immunohistochemistry was carried out in each specimen.ResultsThe mean NA after PDT was significantly lower than that before PDT in the nonrecurrent group. However, there was no significant difference in mean NA before and after PDT in the recurrent group. There were no significance differences in NACV before and after PDT in either the nonrecurrent or recurrent group. Furthermore, the PCNA labelling indices of the specimens after PDT was significantly lower than that before PDT in both the nonrecurrent and the recurrent group.ConclusionsMean nuclear area in the biopsy specimen after photodynamic therapy is likely to be a predictive marker for the recurrence of oral squamous cell carcinoma or epithelial dysplasia subjected to photodynamic therapy, while coefficient of variation of the nuclear area and proliferating cell nuclear antigen labelling indices are less helpful in predicting the recurrence of such lesions.

Ginsenosides promote proliferation of granulosa cells from chicken prehierarchical follicles through PKC activation and up‐regulated cyclin gene expression

The effect of GS (ginsenosides) on proliferation of chicken GCs (granulosa cells) from prehierarchical SYF (small yellow follicles) was evaluated, and involvement of the PKC (protein kinase C) signalling pathway as well as mRNA expression of cyclins and CDK (cyclin-dependent kinase) were investigated. Whole SYF or GCs isolated from SYF were cultured in Medium 199 supplemented with 0.5% FCS (fetal calf serum). After 16 h, the cells were challenged with GS alone or in combination with PKC inhibitor H7 or activator PMA (phorbol 12-myristate 13-acetate) for 24 h in serum-free medium. Results showed that in both whole follicles and pure GCs monolayer culture system, GS (0.1-10 microg/ml) significantly increased the number of GCs in SYF in a dose-dependent manner, and this stimulatory effect was inhibited by H7, but enhanced by PMA. Meanwhile, the PCNA-LI (proliferating cell nuclear antigen labelling index) of GCs displayed similar changes with the cell number. Mechanism of GS action was further evaluated in cultured GCs separated from SYF. Western blot analysis showed that 10 microg/ml GS increased PKC translocation from cytoplasm to the plasma membrane of the GCs to become the active state. This effect was blocked by H7. Furthermore, GS up-regulated the expression of cyclin D1/CDK6 and cyclin E/CDK2 mRNAs in GCs; however, inhibition of PKC with H7 attenuated this stimulatory effect. These results indicated that GS could stimulate proliferation of chicken GCs through activated PKC-involved up-regulation of cyclin D1/CDK6 and cyclin E/CDK2 genes, subsequently promoting development of the chicken prehierarchical follicles.

Mesenchymal stem cells enhance growth and metastasis of colon cancer

Recently, mesenchymal stem cells (MSCs) were reported to migrate to tumor stroma as well as injured tissue. We examined the role of human MSCs in tumor stroma using an orthotopic nude mice model of KM12SM colon cancer. In in vivo experiments, systemically injected MSCs migrated to the stroma of orthotopic colon tumors and metastatic liver tumors. Orthotopic transplantation of KM12SM cells mixed with MSCs resulted in greater tumor weight than did transplantation of KM12SM cells alone. The survival rate was significantly lower in the mixed-cell group, and liver metastasis was seen only in this group. Moreover, tumors resulting from transplantation of mixed cells had a significantly higher proliferating cell nuclear antigen labeling index, significantly greater microvessel area and significantly lower apoptotic index. Splenic injection of KM12SM cells mixed with MSCs, in comparison to splenic injection of KM12SM cells alone, resulted in a significantly greater number of liver metastases. MSCs incorporated into the stroma of primary and metastatic tumors expressed α-smooth muscle actin and platelet-derived growth factor receptor-β as carcinoma-associated fibroblast (CAF) markers. In in vitro experiments, KM12SM cells recruited MSCs, and MSCs stimulated migration and invasion of tumor cells through the release of soluble factors. Collectively, MSCs migrate and differentiate into CAFs in tumor stroma, and they promote growth and metastasis of colon cancer by enhancing angiogenesis, migration and invasion and by inhibiting apoptosis of tumor cells.

Abstract 4255: Significance of mesenchymal stem cells in growth and metastasis of colon cancer

Abstract Background: Recently, mesenchymal stem cells (MSCs) are reported to migrate to tumor sites as well as sites of injury and to incorporate into tumor stroma, but the effects of interactions between MSCs and tumor cells and the mechanisms underlying these effects remain unclear. We examined the role of MSCs in the tumor micro-environment using an orthotopic colon cancer model and a model of liver metastasis from colon cancer. Materials and Methods: Human MSCs labeled with fluorescent dye were injected into tail veins of nude mice bearing KM12SM human colon cancer cells. KM12SM cells alone or KM12SM cells mixed with MSCs were transplanted into the cecal wall or spleen of nude mice. Differentiation of MSCs in primary colon tumors and metastatic liver tumors were also analyzed. Migration assay and invasion assay were performed to examine attraction between KM12SM cells and MSCs in vitro. Results: In in vivo experiments, systemically injected MSCs migrated to the stroma of orthotopic colon tumors and metastatic liver tumors. Orthotopic transplantation of KM12SM cells mixed with MSCs resulted in significantly greater tumor weight than did transplantation of KM12SM cells alone (p &amp;lt; 0.05). The survival rate was significantly lower in the mixed-cell group, and liver metastasis was seen only in this group (p &amp;lt; 0.001). Moreover, tumors resulting from transplantation of mixed cells had a significantly higher proliferating cell nuclear antigen labeling index (p &amp;lt; 0.01), significantly greater microvessel area (p &amp;lt; 0.01), and significantly lower apoptotic index (p &amp;lt; 0.001). Splenic injection of KM12SM cells mixed with MSCs resulted in a significantly greater number of liver metastases than did splenic injection of KM12SM cells alone (p &amp;lt; 0.01). MSCs incorporated into the stroma of primary and metastatic tumors expressed α-smooth muscle actin and platelet-derived growth factor receptor-β as carcinoma-associated fibroblast (CAF) markers. In in vitro experiments, KM12SM cells recruited MSCs, and MSCs stimulated migration and invasion of tumor cells through the release of soluble factors (p &amp;lt; 0.05, respectively). Conclusion: MSCs migrate and differentiate into CAFs in tumor stroma, and they promote growth and metastasis of colon cancer by enhancing angiogenesis and by inhibiting apoptosis of tumor cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4255.

Chemoprevention of 1,2-dimethylhydrazine-induced colonic preneoplastic lesions in Fischer rats by 6-methylsulfinylhexyl isothiocyanate, a wasabi derivative

The preventive effects of dietary exposure to a wasabi derivative 6-methylsulfinylhexyl isothiocyanate (6-MSITC) during the initiation and post-initiation phases on the development of 1,2-dimethylhydrazine (DMH)-induced colonic aberrant crypt foci (ACF), and β-catenin-accumulated crypts (BCAC) were investigated in male F344 rats. To induce ACF and BCAC, rats were given four weekly subcutaneous injections of DMH (40 mg/kg body weight). The rats also received diets containing 200 or 400 ppm 6-MSITC during the initiation or post-initiation phases. The experiment was terminated 12 weeks after the start. DMH exposure produced a substantial number of ACF (323.8±69.7/colon) and BCAC (3.80±1.05/cm(2)) at the end of the study. Dietary administration of 6-MSITC at a dose of 400 ppm during the initiation phase caused a significant reduction in the total number of ACF (52% reduction, P<0.0001), larger ACF (4 or more crypt ACF) (58% reduction, P<0.001) and BCAC (76% reduction, P<0.00001). The dietary exposure to 6-MSITC significantly reduced the size (crypt multiplicity) of BCAC during both initiation and post-initiation treatment when compared to group 1 treated with DMH alone. Immunohistochemically, 6-MSITC administration lowered the proliferating cell nuclear antigen labeling index in ACF and BCAC. In addition, protein levels of hepatic cytochrome P-450 isozymes at 24 h after 6-MSITC exposure were significantly suppressed (P<0.01). The results indicated that 6-MSITC exerted chemopreventive effects in the present short-term colon carcinogenesis bioassay, through alterations in cell proliferation activity and drug metabolizing enzyme levels.

The Impact of the Intra-Abdominal Space on Liver Regeneration After a Partial Hepatectomy in Rats

Little is known about the relationship between intra-abdominal space and liver regeneration. The present study was experimentally designed to investigate the influence of the "occupied space" or the "loss of occupied space" on a regenerating liver. Experiment 1: Rats were randomly assigned to two groups: SO (space occupied) rats (n = 40); occupancy of intra-abdominal space followed by a two-thirds partial hepatectomy (PH) and control rats (n = 40); A PH alone. The rats in both groups were euthanized at 24, 48, 96, and 168 h after the operation. Computed tomography (CT) images were analyzed to evaluate the regenerating-direction and the shape of the regenerated remnant liver. The liver to body weight ratio and the proliferating cell nuclear antigen (PCNA) labeling index were measured at each time point. Experiment 2: A second laparotomy was performed at 168 h after the PH in both groups; occupier-removal for the SO rats and a sham operation for the control rats. The rats in both groups were euthanized at 24 and 168 h after the second operation. The liver to body weight ratio and PCNA labeling index were measured at each time point. Experiment 1: The remnant liver of the SO rats enlarged toward the dorsal and caudal side because liver regeneration toward the ventral side in the SO rats was inhibited with the occupier in the abdominal space at 96 h, and later, after the PH. CT images showed a statistically significant difference in the shape of the regenerated remnant liver between the control group and the SO group. The liver/body weight ratio was significantly decreased in the SO rats at 96 and 168 h after PH (P < 0.05). There was no significant difference between the groups in the PCNA labeling index. The SO rats showed a significant increase of the PCNA labeling of the inferior right lobe (10.6%) in comparison with the index of the superior right lobe (7.8%), which came in direct contact with the occupier, at 96 h after the operation (P < 0.05). The cell density of superior right lobe of the SO rats group was significantly higher than that of the control group at 168 h after operation (P < 0.05). Experiment 2: There was no statistically significant difference in the liver/body weight ratio at 168 hrs after the second operation between the groups. However, there was a statistically significant increase of the PCNA labeling index 24 h after the second operation in the occupier-removal rats in comparison with the control rats (P < 0.05). The occupied intra-abdominal space was therefore found to suppress liver regeneration after a partial hepatectomy, while the removal of such an occupied space stimulated the regeneration of the liver.

Association between shear stress, angiogenesis, and VEGF in skeletal muscles in vivo.

To investigate the hypothesis that capillary proliferation in skeletal muscles, induced by a long-term increase in blood flow which elevates capillary shear stress, is associated with capillary expression of vascular endothelial growth factor (VEGF). Adult rats received prazosin in drinking water ( approximately 2 mg per day) or had extensor digitorum longus (EDL) muscles stimulated by implanted electrodes for up to 14 days. At intervals, serial frozen sections of EDL were stained for alkaline phosphatase to identify capillaries, proliferating cell nuclear antigen (PCNA), and VEGF-A protein. Shear stress was estimated from capillary red blood cell velocities and diameters, measured by direct observation of epi-illuminated EDL. Chronic stimulation and prazosin treatment both increased capillary: fiber ratio by approximately 40% after 14 days. In stimulated muscles, the percentage of capillaries positively stained for VEGF increased within 3 to 4 days, while the density of PCNA-positive capillaries had increased 20-fold after 2 days. With prazosin, VEGF-positive capillaries increased after 2 and 4 days, accompanied by a threefold increase in PCNA. By 14 days, PCNA labeling and VEGF were still high in stimulated muscles, but no longer different from controls with prazosin. After 3 to 4 days of treatment, capillary shear stress in resting muscle was 57% higher than in controls as a result of stimulation, but 4 times higher with prazosin. Higher capillary shear stress with prazosin than with stimulation may upregulate VEGF expression in the early stages of treatment. Greater proliferation of capillaries preceding a higher proportion of VEGF-positive capillaries in stimulated muscles, in the presence of a modest increase in shear stress, suggests that angiogenesis was initiated by other factors in addition to shear stress.

Clinicopathologic and immunohistochemical study of choroid plexus tumors: single-institution experience in Mexican population

In recent years, few studies have specifically focused on only histological features in choroid plexus tumors. We retrospectively reviewed the clinicopathologic and histological features in 37 patients with choroid plexus tumors and correlated these with glial fibrillary acidic protein (GFAP) expression and proliferation cell nuclear antigen (PCNA), p53, p21, and Rb labeling indexes, with special attention to tumor recurrence/regrowth. The study included 24 choroid plexus papillomas (CPPs), 4 atypical choroid plexus papillomas (ACPPs), and 9 choroid plexus carcinomas (CPCs). Patient age ranged from 15 to 70 years (mean 44 years). Most of the choroid plexus tumors were located in the IV ventricle. Recurrence was observed in 21 (52%) cases, 14 of which were CPP and 7 of which were CPC (P = 0.032). Histologic findings included major necrosis, fibrosis and psammoma bodies, amyloid deposits, inflammation, and thick vessels in recurrent tumors. The PCNA labeling index was 52.04 + or - 13.92 in CPPs, 76.50 + or - 17 in ACPPs, and 95.22 + or - 21.34 in CPCs (P = 0.009), and 67.43 + or - 28 in recurrent tumors. Similar values were found for p53, p21, and Rb. Furthermore, we observed that these presented more histological changes, adding, than nonrecurrent tumors, as well as a higher proliferation index of cell-cycle markers, and these were dependent predictor factors of survival. Recurrent tumors showed a different biological behavior than nonrecurrent tumors, but histological observations showed no mitotic features in order to consider them as grade II.

Chemopreventive effects of mate against mouse mammary and colon carcinogenesis.

The present study evaluated the chemopreventive potential of mate tea-like intake on mammary and colon carcinogenesis initiated by 7,12-dimethylbenz(a)antracene (DMBA) and 1,2-dimethylhydrazine (DMH) in female Swiss mice. After the initiation period, the animals received basal diet and organic mate tea-like, conventional mate tea-like, or green tea (positive control) at 2.0% as the drinking fluid during 15 weeks. At week 20, colon and mammary gland were analyzed for preneoplastic and neoplastic lesions development. Colon and mammary gland complexes were processed for cell proliferation analysis, estimated by proliferating cell nuclear antigen labeling index (PCNA-LI%). Specially, organic mate tea-like reduced the values of PCNA-LI% in colonic crypts (p < .003) and in mammary glands (p < .05) in DMBA/DMH-initiated groups. A lower incidence of aberrant crypt foci (ACF) in colon (p = .03) and of hyperplastic and neoplastic lesions in mammary gland (p < .05 and p < .02, respectively) was observed in DMBA/DMH-initiated groups treated with organic mate tea-like. These results suggest that post-initiation treatment with organic mate tea-like inhibited the development of colon and mammary carcinogenesis in a two-step medium-term mouse carcinogenesis model.

Proliferating cell nuclear antigen, p53 and micro vessel density: Grade II vs. Grade III astrocytoma

Histological classification and grading are prime procedures in the management of patients with astrocytoma, providing vital data for therapeutic decision making and prognostication. However, it has limitations in assessing biological tumor behavior. This can be overcome by using newer immunohistochemical techniques. This study was carried out to compare proliferative indices using proliferating cell nuclear antigen (PCNA), extent of p53 expression and micro vessel morphometric parameters in patients with low grade and anaplastic astrocytoma. Twenty-five patients, each of grade II and grade III astrocytoma were evaluated using monoclonal antibodies to PCNA, p53 protein and factor VIII related antigen. PCNA, p53-labeling indices were calculated along with micro vessel morphometric analysis using Biovis Image plus Software. Patients with grade III astrocytoma had higher PCNA and p53 labeling indices as compared with grade II astrocytoma (29.14 plus/minus 9.87% vs. 16.84 plus/minus 6.57%, p 0.001; 18.18 plus/minus 6.14% vs. 6.14 plus/minus 7.23%, p 0.001, respectively). Micro vessel percentage area of patients with grade III astrocytoma was also (4.26 plus/minus 3.70 vs. 1.05 plus/minus 0.56, p 0.001), higher along with other micro vessel morphometric parameters. Discordance between histology and one or more IHC parameters was seen in 5/25 (20%) of patients with grade III astrocytoma and 9/25 (36%) of patients with grade II disease. PCNA and p53 labeling indices were positively correlated with Pearson's correlation, p less than 0.001 for both). Increased proliferative fraction, genetic alterations and neovascularization mark biological aggressiveness in astrocytoma. Immunohistochemical evaluation scores over meet the challenge of accurate prognostication of this potentially fatal malignancy.

Effects of lycopene, synbiotic and their association on early biomarkers of rat colon carcinogenesis

This study evaluated whether a synergy exists for the combined treatment with lycopene and synbiotic on early biomarkers of colon carcinogenesis. Male Wistar rats received a diet containing 300mg/kg of lycopene and/or synbiotic (Bifidobacterium lactisplus oligofructose/inulin) or their combination 2weeks before and during carcinogen treatment with 1,2-dimethylhydrazine (DMH). Twenty-four hours after the last DMH application, the colons were processed for immunohistochemical analysis of proliferating cell nuclear antigen (PCNA), p53 protein, hematoxylin–eosin staining for apoptosis analysis and genotoxicity of fecal water by comet assay. Eight weeks after the last DMH application, the colons were analyzed for development of classical aberrant crypt foci (ACF) and mucin-negative ACF. Treatment with lycopene, synbiotic or their combination significantly increased apoptosis, reduced the PCNA and p53 labeling indexes and the development of classical ACF and mucin-negative ACF. Furthermore, a lower genotoxicity of fecal water was also detected in the groups treated with the chemopreventive agents. An additive/synergistic effect of the combined treatment with lycopene/synbiotic was observed only for the fecal water genotoxicity and mucin-negative ACF parameters. These results indicate that an additive/synergistic of the combination of chemopreventive agents on the initiation phase of colon carcinogenesis can be detected using selective early biomarkers.

Expression of Ki-67, PCNA, and p27kip1 in canine pituitary corticotroph adenomas

Pituitary-dependent hypercortisolism (PDH), which is caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas, is a common endocrinopathy in dogs. Dogs with non-enlarged pituitaries harboring a microadenoma have a better prognosis than those with enlarged pituitaries. The aim of this study was to investigate the expression of the proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) and the cell-cycle inhibitor p27kip1 in corticotroph adenomas in enlarged and non-enlarged pituitaries. The expression of Ki-67, PCNA, and p27kip1 was analyzed by immunohistochemical staining of 17 pituitary adenoma samples harvested during pituitary surgery in dogs with PDH. The labeling index was calculated by counting the number of immunopositive cells per 1,000 cells. The mean (± standard deviation) labeling index for Ki-67 was 8.4% ± 14.2% for the group with enlarged pituitaries, and 8.8% ± 5.5% for the group with non-enlarged pituitaries; that for PCNA was 35.5% ± 12.2% and 37.0% ± 15.5%; and that for p27kip1 was 29.3% ± 22.6% and 42.5% ± 27.9%, respectively. No significant differences in Ki-67, PCNA, and p27kip1 labeling indices were found between enlarged and non-enlarged pituitaries. However, a trend toward significance was observed when comparing the expression of p27kip1 in enlarged pituitaries versus normal pituitary tissue. It is concluded that Ki-67 and PCNA are not useful as proliferative markers for studying the pathobiology of pituitary corticotroph adenomas in dogs.

Regenerative capacity of normal and irradiated liver following partial hepatectomy in rats

Purpose: To investigate the regenerative capacity and proliferation related to cell cycle modulators in irradiated livers after partial hepatectomy (PH) in rats.Methods and materials: Two experimental groups were given a single dose of either 4-Gy or 8-Gy photon radiation to the whole liver following PH. The control group underwent only PH, without irradiation. The liver specimens were analysed for apoptosis, proliferation and cell cycle related genes between 0.5 and 12 days.Results: Mean change in weight of the remnant liver in the 8-Gy group was significantly lower than in the control and 4-Gy groups. The apex of proliferating cell nuclear antigen labelling and bromodeoxyuridine incorporation index in two irradiated groups were also apparently lower than that in control group. After PH, transforming growth factor beta-1 (TGFβ1), and the type II receptor of TGFβ (TGFβR-II), anti-tumour protein 53(p53) and anti-tumour protein21(p21) protein expression in the irradiated livers was higher than in unirradiated ones. Significant apoptosis was noted in 8-Gy group. However, the maximal value of hepatocyte growth factor (HGF) mRNA and protein expression in the irradiated group was suppressed and restoration of liver function was delayed.Conclusion: Whole liver lower dose irradiation can attenuate regenerative capacity following partial hepatectomy in rats.