Proliferating cell nuclear antigen and nucleolar organizer regions in CNS tumors: correlation with histological type and tumor grade. A comparative study of 82 cases on paraffin sections

Ki-67 immunoreactivity in type II malformations of cortical development

Malformations of cortical development (MCD) are a well-recognized cause of chronic epilepsy. Most MCD are defined by the neuronal component of the lesion and are considered to be relatively "static" lesions. Twenty-one cases of MCD type II (Taylor type cortical dysplasia) were retrospectively evaluated with Ki-67 antibody looking for evidence of cell proliferation and evaluating populations of cells that may be proliferating. Resections were from 13 males and 8 females who ranged in age at the time of surgery from 6 weeks to 57 years (mean 8.6 y) and who had a duration of seizures before surgery of 1.5 months to 34.4 years (mean 6.5 y). Dysmorphic neurons were observed in all cases and balloon cells in 18/21 (86%) cases. Ki-67 labeling indices ranged from 0.2% to 4.9% (mean 2.0%). Coimmunolabeling with Ki-67 and antibodies to glial fibrillary acidic protein, CD68, and CD45RB showed that the majority of the Ki-67-positive cells were astrocytic (glial fibrillary acidic protein positive). In 9/21 cases (43%), endothelial cell staining with Ki-67 was also observed. These results suggest that low rates of cell proliferation are observable in type II MCD. The proliferating cells appear to be primarily astrocytic and endothelial in nature and suggest that these lesions are not static. Dysmorphic neurons and balloon cells in MCD were not observed to stain with Ki-67.

Angiogenesis and inflammation in skeletal muscle in response to ascites tumor in mice

This study addresses the interaction between Ehrlich ascites tumor and skeletal abdominal muscle, presenting quantitative analysis of ascites-induced angiogenesis and inflammation in this tissue of mice bearing-tumor. Time-dependent changes in the muscle (cellular activity, angiogenesis, inflammation and cytokines production) were assessed by morphometric, functional, and biochemical parameters at days 1, 4 and 8 after i.p. inoculation of Ehrlich tumor cells (2.5 x 10(7)). The number of cells stained with AgNOR technique (argyrophilic nucleolar organizer region) in the muscle, together with MTS assay used as markers of cellular activity increased progressively in parallel with the out flow rate of sodium fluorescein (blood flow index), hemoglobin content (vascular index) and VEGF production. Likewise, the inflammatory process in the muscle, as assessed by myeloperoxidase (MPO) and n-acethylglucosaminidase (NAG) activities and the levels of the chemokines, keratinocyte-derived chemokine (CXC1-3/KC) and macrophage-chemoattractant protein (CCL2/MCP-1) increased with tumor development. The combination of techniques used to describe angiogenesis and inflammation in a muscle model system has proved to be suited for quantitative measurements of microvascular changes and cellular infiltration occurring in the abdominal muscle wall of ascites-bearing mice. This study holds potential for investigating events and mechanisms associated with skeletal muscle response to neoplasic stimulus.

Proteome Analysis of NIH3T3 Cells Transformed by Activated Gα12: Regulation of Leukemia-Associated Protein SET

Galpha(12), the alpha-subunit of the G12 family of heterotrimeric G proteins is involved in the regulation of cell proliferation and neoplastic transformation. GTPase-deficient, constitutively activated mutant of Galpha(12) (Galpha(12)Q229L or Galpha(12)QL) has been previously shown to induce oncogenic transformation of NIH3T3 cells promoting serum- and anchorage-independent growth. Reduced growth-factor dependent, autonomous cell growth forms a critical defining point at which a normal cell turns into an oncogenic one. To identify the underlying mechanism involved in such growth-factor/serum independent growth of Galpha(12)QL-transformed NIH3T3, we carried out a two-dimensional differential proteome analysis of Galpha(12)QL-transformed NIH3T3 cells and cells expressing vector control. This analysis revealed a total of 22 protein-spots whose expression was altered by more than 3-folds. Two of these spots were identified by MALDI-MS analysis as proliferating cell nuclear antigen (PCNA) and myeloid-leukemia-associated SET protein. The increased expressions of these proteins in Galpha(12)QL cells were validated by immunoblot analysis. Furthermore, transient transfection studies with NIH3T3 cells indicated that the expression of activated Galpha(12) readily increased the expression of SET protein by 24 h. As SET has been previously reported to be an inhibitor of phosphatase PP2A, the nuclear phosphatase activity was monitored in cells expressing activated Galpha(12). Our results indicate that the nuclear phosphatase activity is inhibited by greater than 50% in Galpha(12)QL cells compared to vector control cells. Thus, our results from differential proteome analysis presented here report for the first time a role for SET in Galpha(12)-mediated signaling pathways and a role for Galpha(12) in the regulation of the leukemia-associated SET-protein expression.

Clinicopathologic study of 61 patients with ependymoma including MIB-1 immunohistochemistry

Predicting behavior based on histologic appearance has been problematic in ependymomas. Sixty-one patients with ependymoma (excluding subependymoma and myxopapillary ependymoma) were studied. The patients included 36 men and ranged in age from 1.5 to 74 years (median, 33 years). The most common clinical presentations included headache (n = 19), weakness (n = 18), nausea/vomiting (n = 12), and gait disturbance (n = 10). Location included spinal cord (n = 24), fourth ventricle (n = 21), lateral ventricle (n = 8), and third ventricle (n = 5). Initial surgery included a gross total resection of tumor in 22 patients and subtotal resection or biopsy in the remaining patients. Thirty-five patients were known to have been treated with adjuvant radiation therapy and 13 patients received adjuvant chemotherapy. At last known follow-up, 20 patients were alive with no evidence of tumor (median, 66.5 months), 17 patients were alive with residual tumor (median, 14 months), and 12 patients died of tumor (median, 27.5 months). Two additional patients are alive with tumor status not known, two cases are current, and two patients were lost to follow-up. The additional six patients died either shortly after surgery or of surgical complications. Sixteen of 18 patients had at least one tumor recurrence at median 28.5 months. Fifty-one tumors had a predominantly glial pattern and 10 had a mixed glial-epithelial pattern. Of histologic features examined, patients with tumor recurrence or who died of tumor more frequently had observable mitotic figures, vascular proliferation, necrosis, and foci of increased cellularity. Eight of 18 recurrent tumors were classified as high grade ependymomas (anaplastic/malignant). Of patients who died of tumor, 4 of 12 had histologically high grade tumors versus 5 of 39 of the remaining tumors. MIB-1 immunostaining (marker of cell proliferation) was performed on 50 tumors. MIB-1 labeling indices (% positive tumor cell nuclei) ranged from 0.1 to 34.0 (median, 1.1). A higher percentage of patients with recurrent tumor (6 of 13, 46%) or who died of tumor (3 of 10, 30%) had MIB-1 indices >/= 4.0 versus the remaining patients (8 of 33, 24%). The conclusions are as follows: (1) histologic appearance and MIB-1 indices were not reliably predictive of tumor behavior, probably due in part to tumor heterogeneity; (2) tumors with two or more of the following features: identifiable mitotic figures, hypercellularity, vascular proliferation, and necrosis were more likely to behave in an aggressive manner; and (3) elevated MIB-1 labeling indices (>/=4.0 in this study) were encountered in a higher percentage of fatal and recurrent tumors than in nonfatal or nonrecurrent tumors.

Cyclin D1 and MIB-1 immunohistochemistry in pilocytic astrocytomas: a study of 48 cases

Pilocytic astrocytoma is an infrequently encountered, generally low-grade neoplasm. No study has extensively looked at both cyclin D1 and MIB-1 labeling indices in pilocytic astrocytoma and their relation to clinical outcome. This study retrospectively examines the clinicopathologic features of 48 patients with pilocytic astrocytoma including MIB-1 (cell proliferation marker) and cyclin D1 (protein that regulates progression from G1 to S phase of the cell cycle) immunohistochemistry. Of 48 patients (27 females and 21 males; mean age, 12.7 years; age range, 2 to 57 years), 26 initially underwent gross total resection; 17, subtotal resection; four, biopsy alone; in one patient, the extent of tumor resection was unknown. Histological features observed included Rosenthal fibers (83.3%), granular bodies (75%), vascular sclerosis (56.2%), vascular proliferation (56.2%), prominent nuclear pleomorphism (14.6%), necrosis (10.4%), and identifiable mitotic figures (2.1%). MIB-1 labeling indices (n=45) (positive staining tumor nuclei per 1,000 nuclei evaluated) ranged from 0 to 3.5% (mean, 0.6%); seven tumors had a labeling index greater than 1.0%. Cyclin D1 labeling indices (n=45) ranged from 0 to 0.8% (mean, 0.1%). Most tumors (N=29, 66.7%) had no immunostaining. At last known follow-up, 27 patients were alive with no evidence of disease (mean, 49.2 months), 17 patients were alive with evidence of disease (mean, 36.8 months), three died with tumor at 2, 22, and 156 months, and one patient was lost to follow-up. Eight patients had at least one tumor recurrence requiring additional surgery; seven of these patients had an initial subtotal resection. In summary, MIB-1 labeling indices were generally low (mean, 0.6%) and are reflective of the slow growth of the tumors. Cyclin D1 immunostaining does not appear to be significantly increased in pilocytic astrocytoma. Adverse outcome in patients with pilocytic astrocytoma may be related to extent of surgical resection and does not seem to correlate with histology, MIB-1 labeling indices, or cyclin D1 immunoreactivity.

Evaluation of argyrophilic nucleolar organizer regions (AgNORs) in oral carcinomas in relation to human papillomavirus infection and cytokinetics

The numbers of argyrophilic nucleolar organizer regions (AgNORs) were quantified in oral carcinomas (n = 39) with or without human papillomavirus (HPV) infection. The AgNOR counts of the HPV-positive samples (7.15 +/- 2.13) were not significantly (P = 0.09) higher than those of the HPV-negative ones (6.16 +/- 1.89). Furthermore, the lesions infected with multiple HPV types had greater counts than those with HPV type 16/18 infection alone. Significant differences were observed between the mean counts of the poorly (10.50 +/- 0.54), moderately (7.31 +/- 1.07) and well- (5.12 +/- 0.85) differentiated carcinomas. The mean AgNOR numbers in the oral carcinomas at TNM stages III/IV were found to be significantly (P < 0.01) higher than the numbers in corresponding stage II lesions. Cytokinetics of the lesions assessed by the bromodeoxyuridine (Brdu) labelling index (LI%) showed a linear correlation (r = 0.91; P < 0.0001) with their respective mean AgNOR counts.

Aneuploidy in sclerosing adenosis may predict an increased risk of malignancy. A study using the AgNOR silver stain

Sclerosing adenosis (SA) of the breast if a disease associated with an increase relative risk of malignancy. The exact incidence and factors influencing malignant transformation in association with SA are not well established. Two counts of the AgNOR silver staining technique have been correlated with ploidy and proliferative activity. The first count which is the mean number of AgNOR granules (mAgNOR), correlates with ploidy. The second count is the percentage of nuclei exhibiting > or = 5 AgNORs/nucleus (pAgNOR) and reflects proliferative activity. The hypothesis in the current study was that aneuploidy, as determined by the AgNOR silver staining technique, may potentially identify lesions of SA with an increased association with malignant breast disease. The AgNOR silver staining technique was performed on 69 cases of SA with the application of the two counts. Of these cases 53 were not associated with malignancy and 16 were associated with synchronous or metachronous carcinoma of the breast, these being 11 cases of invasive ductal carcinoma (IDC), four cases of ductal carcinoma in situ (DCIS) and one case of lobular carcinoma in situ (LCIS). The patient ages ranged from 27 to 84 years (median 53 years) with a median follow up of 28 months. Six of the 53 cases of SA no associated with malignancy (11%) had aneuploid mAgNOR counts of > or = 2.4 whereas 12 of the 16 cases associated with carcinoma (80%) had such counts (p < 0.0005). This included nine cases of IDC, two cases of DCIS and the case of LCIS. Of the six aneuploid cases not associated with malignancy, two cases showed cytological atypia, one case was associated with atypical ductal hyperplasia and one case was seen in a leukemic patient who had received chemotherapy and radiation therapy. The pAgNOR counts showed a statistically less significant correlation with malignancy (p < 0.03). These findings suggest that aneuploidy, measured by the AgNOR silver stein, seen in SA may help identify lesions with a higher relative risk of being associated with breast carcinoma and hence that may require more aggressive management than diploid ones.

Cell kinetics analysis of surgically resected non-small cell carcinoma of the lung using the AgNOR silver stain

Cell kinetics analysis of lung carcinoma using DNA flow cytometry has shown a significant correlation with the biological behavior of these neoplasms. Ploidy has shown a more significant association with aggressive behavior. The method may however not be available in all centers. Two counts of the AgNOR silver stain have been correlated with ploidy and proliferative activity (PA). The first count, which is the mean number of AgNOR granules (mAgNOR), correlates with ploidy. The second count is the percentage of cells with > 5 AgNORs/nucleus (pAgNOR), reflects PA. We performed the AgNOR silver stain using the two above-mentioned counts in 41 cases of surgically resected nonâsmall cell carcinoma of the lung. The cases included 14 adenocarcinomas, 24 squamous cell carcinomas, and three undifferentiated nonâsmall cell carcinomas. Follow-up data were available on 36 of the patients, ranging from 10 to 31 months (median 18 months). Thirteen of these patients (36%) developed progressive disease. Adenocarcinomas showed mAgNOR counts suggestive of aneuploidy (> 2.4) in nine of the 14 patients (64%) and 16 of the 24 squamous carcinomas (66%). The adenocarcinomas showed high pAgNOR counts (> 8%) in eight of the 14 cases (57%), in contrast to 15 of the 24 squamous carcinomas (62%). The AgNOR counts did not show any statistically significant correlation with tumor type, grade or stage of disease. The mAgNOR counts were aneuploid in all 13 progressive cases and in only 10 of the 23 stable cases (43%)(P=0.001). The pAgNOR counts were high in 12 of the 13 cases that progressed (92%), in contrast to 10 of the 23 stable cases (43%)(P=0.01). There is no significant evidence that squamous carcinoma of the lung may have a higher incidence of aneuploidy and high PA than adenocarcinoma. Our data also confirm previous data showing that aneuploid lung carcinomas have more aggressive behavior than diploid ones. This study also indicates that, despite the short-term follow-up data, the use of the AgNOR silver stain for cell kinetics analysis of nonâsmall cell carcinoma of the lung may potentially provide useful predictive information on the biologic behavior of lung carcinoma. Long-term follow-up may provide more significant information.

MDM2 and p53 expression in gliomas: a multivariate survival analysis including proliferation markers and epidermal growth factor receptor

p53 and the murine double minute 2 (MDM2) oncoprotein expression was evaluated in paraffin-embedded tissue from 61 patients with central nervous system gliomas (53 astrocytomas and eight oligodendrogliomas) and related to proliferation-associated markers [i.e. proliferating cell nuclear antigen (PCNA), Ki-67 and nuclear organizer regions (NORs)] and epidermal growth factor receptor (EGFR). We used the monoclonal antibodies PC-10, MIB-1, DO-1, 1B1O and EGFR 113 and the colloid silver nitrate (AgNOR) technique. MDM2 and p53 were co-expressed in 28% of cases. A p53-positive/MDM2-negative phenotype was observed in 15% and a p53-negative/MDM2-positive phenotype in 20% of cases. There was a positive correlation of p53 and MDM2 expression with grade and proliferation indices. Univariate analysis in the group of diffuse astrocytomas showed that older age, high histological grade, high PCNA labelling index (LI) and high AgNOR score were associated with reduced overall survival (P < 0.05). p53 LI, Ki-67 LI, AgNOR score, tumour location and grade influenced disease-free survival (P < 0.05), whereas the only parameters affecting post-relapse survival were histological grade and Ki-67 LI (P < 0.1). Multivariate analysis revealed that age, radiotherapy, PCNA LI and p53 LI were the independent predictors of overall survival. p53 LI, Ki-67 LI, MDM2 LI, EGFR LI, grade and type of therapy were independent predictors of disease-free survival, and grade was the only independent predictor of post-relapse survival. Our results indicate that p53 LI and MDM2 LI, EGFR expression as well as proliferation markers (PCNA and Ki-67) are useful indicators of overall and disease-free survival in diffuse astrocytoma patients.

The level of MnSOD is directly correlated with grade of brain tumours of neuroepithelial origin

The oxy-radical scavenger enzyme manganese superoxide dismutase (MnSOD) may act in the capacity of a tumour-suppressor gene. To address the issue of its role in tumour transformation and progression in vivo, we evaluated the content of this enzyme in 33 brain tumours of neuroepithelial origin with different degrees of differentiation (WHO grade II-IV) by means of Western blot and immunohistology. Our results show that immunoreactive MnSOD increases in a direct relationship with tumour grade and is therefore inversely correlated with differentiation. The increase in induced at a pretranscriptional level and is apparently specific to brain tumours of neuroepithelial origin. Approximately 30% of grade IV tumours display low levels of MnSOD content, and preoperative radiotherapy and brachytherapy result in low amounts of enzyme. Based upon these observations, we suggest that MnSOD cannot be considered a classical tumour-suppressor gene.

Proliferating cell nuclear antigen (PCNA) and Ki-67 immunopositivity in human astrocytic tumours

To compare the Ki-67 and Proliferating Cell Nuclear Antigen (PCNA), markers of cell proliferation, paraffin embedded surgical specimens from 56 human astrocytic tumours (8 pilocytic tumours, grade I; 9 low (II) grade and 9 anaplastic (grade III) astrocytomas and 30 glioblastomas, grade IV) were immunolabelled with the anti-PCNA (PC 10, DAKO) and anti-Ki-67 (DAKO) antibodies. For the latter immunostaining the microwave oven processing was performed. The Ki-67 and PCNA labelling indices (LIs) were statistically compared. For the majority of cases, PCNA LI was higher than that obtained with anti-Ki-67 antibody and the intensity of staining for PCNA was more variable. The statistically significant difference of the percentage of PCNA LIs was found only between low grade (I and II) and high grade (III and IV) tumours, while Ki-67 LIs discriminates each group of glial tumours; thus this latter marker is more sensitive and specific.

Comparative evaluation of p53-protein expression and the PCNA and Ki-67 proliferating cell indices in human astrocytomas

Mutations of the p53 gene are one of the most frequent genomic alterations of human tumours of astrocytic lineage. Because the physiological role of this gene is a suppression of cellular proliferation and growth, the overexpression of p53-protein may correlate with the expression of PCNA or Ki-67, established markers of cell proliferation. Paraffin-embedded surgical specimens from 60 human astrocytomas (9 pilocytic tumours, 12 WHO grade II, 9 anaplastic astrocytomas [WHO grade III] and 30 glioblastomas [WHO grade IV]) were stained with anti-PCNA (PC10), anti-p53(DO-7) and anti-Ki-67 antibodies (DAKO). Approximately 40% of all the cases were p53-protein immunopositive (53.3% glioblastomas, 33.3% anaplastic, 41.7% low grade astrocytomas but no pilocytic tumor). Statistical analysis did not reveal statistically significant correlation between p53-immunopositivity and PCNA or Ki-67 labeling indices. The Ki-67- and PCNA LI-s were statistically correlated, and the former better discriminated groups of different grades of malignancy.

Recurrence of meningiomas versus proliferating cell nuclear antigen (PCNA) positivity and AgNOR counting

Meningiomas have a wide range of biological potential and clinical behaviour. Histological findings are helpful in recognizing the malignant potential but often fail to correlate with clinical behaviour. This study attempts to correlate the silver nucleolar organizer regions (AgNORs) and proliferating cell nuclear antigen (PCNA) with clinicopathological features of biological activity. Thirty-four completely resected meningiomas were classified as benign [19], atypical [6] and malignant [9]. Forty-eight initial and recurrent tumour materials were investigated for staining of AgNORs and immunohistochemistry using monoclonal antibodies against PCNA (clone 19A2 and PC10). There were no difference between the recurrent and non-recurrent cases with regards to AgNOR, PC10 and 19A2 values. Also, no significant difference was found between the primary and recurrent tumours. Both PC10 and 19A2 labelling indices (LI) showed a significant difference between benign and malignant meningiomas. The 19A2 LI was 0.56 +/- 0.21 in benign and 2.45 +/- 16 in atypical meningiomas. The 19 A2 counts showed significant difference between benign and atypical tumours but PC10 values failed to show such a correlation AgNOR and PCNA indices were not found to be useful in predicting recurrences compared to the surgical procedure and histopathological criteria.

Prognostic significance of proliferating cell nuclear antigen (PCNA) expression in gliomas

The relationship between proliferating cell nuclear antigen (PCNA) expression and various clinicopathological indices (age, sex, tumour location, histological type and grade and treatment) and post-operative survival were studied in patients with central nervous system gliomas using univariate and multivariate analysis. The expression of PCNA (PC10 score) was examined immunohistochemically using the monoclonal antibody PC10 on paraffin sections from 45 cases. Univariate analysis showed that a high PC10 score as well as older age, high histological grade and the histological type (astrocytoma) were associated with reduced survival. However, multivariate analysis revealed that only PC10 score and histological type had independent prognostic significance. The most important feature influencing PC10 score was the tumour grade. Regarding the patients who relapsed, the survival from the time of original diagnosis was related to the relapse-free period, while the PC10 score of the primary tumour emerged as the only independent predictor of survival following the first recurrence. These results indicate that PCNA expression is an independent prognostic indicator in CNS gliomas.

The biology and pathology of selected skull base tumors

This paper describes the pathobiology of some of the more common skull base tumors. In addition to clinicopathologic features, emphasis is placed upon methods of diagnosis utilizing immunoperoxidase stains and molecular markers that may or may not impact upon prognosis.