Immunohistochemical study of Ki-67 (MIB-1), p53 protein, p21WAF1, and p27KIP1 expression in benign, atypical, and anaplastic meningiomas

Histologic grading of meningiomas has prognostic and clinical therapeutic implications. Meningiomas were histologically classified into 3 different World Health Organization grades. Grade II, an atypical meningioma, was defined by major and various minor histologic criteria. However, these histologic criteria sometimes are not fulfilled, and other criteria are necessary. We studied and analyzed the immunohistochemical expression of MIB-1, p53, p21WAF1, p27KIP1 proteins in 146 cases of meningiomas, including 109 benign, 27 atypical, and 10 anaplastic meningiomas. Most of the benign meningiomas expressed low MIB-1 labeling index (mean, 1.5%), and fewer cases had p53 protein expression. In contrast, the anaplastic meningiomas had a high labeling index of MIB-1 (mean, 19.5%) and always expressed p53 protein, with a mean labeling index of 6.3%. The atypical meningiomas had MIB-1 and p53 labeling indexes in the range between benign and anaplastic meningiomas, with mean labeling indexes of 8.1% and 3.5%, respectively. These expressions were statistically significant among benign, atypical, and anaplastic meningiomas (P <.001). We conclude that the immunohistochemistry of MIB-1 and p53 protein will be valuable in discriminating atypical meningiomas from benign or anaplastic meningiomas, at least in histologically borderline cases. In addition, we also found direct correlation of p21 and inverse correlation of p27 expressions in meningiomas with increasing histologic grade and proliferative index.     

DNA topoisomerase II-alpha and cyclin A immunoexpression in meningiomas and its prognostic significance: an analysis of 263 cases

CONTEXT: Routine pathologic examination cannot distinctively predict the clinical course of meningiomas because even histologically benign tumors may recur after gross total resection. Therefore, numerous efforts have been made to evaluate the meningioma growth fraction and its prognostic value. However, a universally applicable proliferative marker for meningioma outcome is not yet a reality. OBJECTIVE: To investigate the prognostic utility of 3 proliferative markers, namely, Ki-67, DNA topoisomerase II-alpha (topoII), and cyclin A in a representative series of intracranial meningiomas. DESIGN: Two hundred sixty-three adult patients with intracranial meningiomas (208 benign, 42 atypical, and 13 anaplastic) were studied retrospectively. Tumor specimens were immunohistochemically examined with antibodies to Ki-67 (MM-1), topoII, and cyclin A. A computerized color image analyzer was used to count immunostained nuclei. RESULTS: The topoII and cyclin A scores exhibited a close correlation with Ki-67 immunostaining. Significant differences between the indices for all 3 markers were noted among the 3 grades of meningiomas. The scores for all 3 markers were significantly different between recurrent and nonrecurrent meningiomas, including benign tumors that were treated with gross total resection. Recurrence-free survival was significantly reduced for cases with a Ki-67 labeling index (LI) of 4.4% or greater, a topoII LI of 3.2% or greater, and a cyclin A LI of 3.1% or greater. Multivariate analysis revealed that the risk of recurrence for the entire meningioma cohort was significantly associated with tumor grade (hazard ratio = 2.7; P =.004), topoII LI of 3.2% or greater (hazard ratio = 5.5; P <.001), and a cyclin A LI of 3.1% or greater (hazard ratio = 2.4; P =.01). CONCLUSIONS: There is a close correlation in the expression of these 3 proliferative markers in meningiomas, and all of the markers showed a significant association with tumor grade, recurrence rate, and recurrence-free survival. Consequently, in addition to Ki-67, immunoexpression of topoII and cyclin A is available for predicting meningioma recurrence. Moreover, the topoII and cyclin A staining scores were found to be more sensitive predictors for meningioma progression than Ki-67 and, therefore, either of these 2 markers may prove to be clinically informative and useful.     

Correlation of p63 protein expression with histological grade of meningiomas: an immunohistochemical study

Prediction of tumor behavior in meningiomas based on morphological features alone remains difficult. Several immunohistochemical biomarkers have been proposed to assist conventional methods. However, no single immunohistochemical marker can unequivocally discriminate between benign and aggressive meningiomas. There is only 1 study available in the literature that correlates p63 expression with overall histological grade of the meningioma. The present study is undertaken to assess the correlation between p63 expression and histological grade of meningiomas. For this purpose, the authors studied and analyzed the immunohistochemical expression of p63 in 85 cases of meningioma, including WHO grade I (63), grade II (11), and grade III (11) cases. Correlation between histological grade and nuclear immunoreactivity to p63 antibody was performed. Furthermore, expression of p63 protein was correlated with short clinical follow-up and Ki-67 proliferation index. Among 85 patients analyzed, there were 61 women (71.7 %) and 24 men (28.2%) between 7 and 75 years old. Expression of p63 protein was found in 34.9% of grade I cases, but in grade II and III, 63.6% of cases each were immunoreactive. Correlation between histological grade and p63 immunoreactivity was significant (P = .02). p63-positive grade I meningiomas did not show elevated Ki-67 index. The present study contradicts earlier reports because there are a considerable number of grade I meningiomas that express p63. Although p63 expression is significantly associated with higher histological grade of meningiomas, it may not be considered as a sole biomarker to assess aggressive behavior of the tumor.     

Role of p53 gene mutation in tumor aggressiveness of intracranial meningiomas.

The mutations that occur in the p53 tumor suppressor gene have been studied in various human malignant tumors. However, little is known about this gene in meningiomas. To investigate the relationship and frequency of p53 gene mutations, the p53 polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and immunohistochemical study were performed on the 41 intracranial meningiomas (21 benign, 11 atypical, and 9 malignant). The higher the p53 protein expression rate, the poorer the histologic grade (9.5%, 72.7%, and 88.9% in benign, atypical and malignant meningioma, respectively) (p=0.000). The p53 protein expression rate was higher in recurrent meningioma (71.4%) than in nonrecurrent meningioma (10.5%) (p=0.002). PCR-SSCP method was performed in positive p53 protein immunoreactivity cases. p53 gene mutation rate was higher in the atypical (62.5%) and malignant (25%) meningiomas than in the benign meningioma (0%) (p=0.232). Also, the rate was higher in recurrent menigioma (20%) than in nonrecurrent meningioma (0%) (o=0.495). Among five to eight exons of the p53 gene, the mutation was observed on exon 7 more frequently. In conclusion, p53 immunoreactivity and p53 gene mutation are closely correlated with histologic grade and histologic atypia of intracranial meningiomas. p53 gene mutation would be considered as a useful marker to detect the progression of intracranial meningiomas.     

胃肠道间质瘤中p16、p27、Ki-67表达

目的探讨胃肠道间质瘤中p16、p27和Ki67表达与临床预后的关系。方法根据核分裂象的多少、肿瘤体积的大小及有无浸润等将胃肠道间质瘤划分为良性、交界性和恶性,并运用免疫组化SP方法检测p16、p27和Ki67在胃肠道间质瘤中的表达,并统计分析其良性、交界性、恶性和复发死亡病例中的表达差异。结果p16、p27和Ki67的阳性表达率分别为48%、26%和24%。p16在良、恶性中的表达无明显差异,但在良性和交界性中的表达与复发和转移相关;p27低标记指数和Ki67高标记指数与复发和转移相关。结论p16、p27和Ki67在胃肠道间质瘤中的表达对判断预后有价值。     

Methylation of p14(ARF) gene in meningiomas and its correlation to the p53 expression and mutation.

We have previously reported the statistically significant correlation of immunohistochemical expression of MIB-1 and p53 proteins among benign, atypical, and anaplastic meningiomas and p53 protein expression was high in atypical and anaplastic meningiomas. In the present study, we analyzed 22 cases of meningiomas for mutation of p53 gene in its spectrum of exon 5 to 8 using automated genetic analyzer. We did not find any mutation of p53 in any of these cases, thus suggesting the p53 protein expression is wild type. We analyzed 72 cases of meningiomas for determining the methylation status of p14(ARF) gene and the immunohistochemical expression of MDM2 protein to explain p53 protein expression in these meningiomas. We found methylation of p14(ARF) gene in five of 58 cases of benign meningiomas (8.6%), two of 10 cases of atypical meningiomas (20%), and two of four cases of anaplastic meningiomas (50%). In absence of p53 gene mutation, the high percentage of p14(ARF) gene methylation in high-grade meningioma may have been responsible for accumulation of wild-type p53 protein. In addition, we also found the loss of MDM2 protein in high-grade meningiomas. These deregulations of p14-MDM2-p53 pathway may contribute to the malignant progression of meningioma.     

Immunohistochemical analysis of Ki-67, p53, p21, and p27 in benign and malignant apocrine lesions of the breast: its correlation to histologic findings in 43 cases.

We examined Ki-67, p53, p21, and p27 immunolocalization in 43 cases of apocrine lesions of the breast and correlated these findings with histologic parameters to understand their biologic significance. Twenty cases were benign, 1 case was borderline, and 22 cases were diagnosed as malignant, including 9 intraductal and 13 invasive apocrine carcinomas. Both the ratio of Ki-67-positive cases (17 of 21 [88.9%] versus 1 of 19 [5.3%]; P < .001) and the Ki-67 labeling index of positive cases examined (15.0% versus 2.7%; P < .005) were significantly higher in malignant than in benign apocrine lesions. None of the benign or borderline cases was immunohistochemically positive for p53, but 15 of 22 malignant cases (68.2%) demonstrated p53 (P < .001). In addition, the ratio of p53-positive cases was significantly higher in high nuclear grade cases (11 of 13 [84.6%]) than in intermediate nuclear grade cases (4 of 9 [44.4%]; P < .05). P53 immunoreactivity was also positively correlated with the nuclear grade of carcinoma cases examined in this study. Neither p21 nor p27 demonstrated any correlation with histologic parameters or findings of the apocrine lesions. Results of these studies suggest that Ki-67 and p53 may be good markers for differentiation between benign and malignant breast apocrine lesions.     

Immunohistochemical expression of SPARC is correlated with recurrence,survival and malignant potential in meningiomas

Meningioma is a common neoplasm that constitutes almost 30% of all primary central nervous system tumors and is associated with inconsistent clinical outcomes. The extracellular matrix proteins play a crucial role in meningioma cell biology and are important in tumor cell invasion and in progression to malignancy. SPARC (secreted protein, acidic and rich in cysteine) (osteonectin) is a matricellular glycoprotein that regulates cell function by interacting with different extracellular matrix proteins. The aim of this study was to evaluate the expression of SPARC with proliferation index, p53 reactivity in WHO grade 1 (benign), grade 2 (atypical) and grade 3 (anaplastic) meningiomas and correlate with clinical features of the patients, including location of the tumor, recurrence of the tumor and survival of patients. We studied 111 meningiomas, 69 being benign, 34 being atypical and eight being anaplastic meningiomas of various histological types. Using immunohistochemical analysis, we evaluated the expression of SPARC, Ki‐67 (MIB‐1) and p53 in meningiomas. Immunohistochemical scores of SPARC were determined as the sum of frequency (0–3) and intensity (0–3) of immunolabeling of the tumor cells. A high immunohistochemical score (4–6) for SPARC was more frequent in atypical and in anaplastic meningiomas than in benign meningiomas (p < 0.01). MIB‐1 proliferation index showed significant association between tumor grades in meningiomas (p < 0.01). At the end of a follow‐up period of 47.53 ± 25.04 months, 30 tumors recurred. A high SPARC expression was significantly associated with tumor recurrence (p = 0.02). The immunoreactivity of p53 protein and MIB‐1 score were significantly higher in recurrent meningiomas than in non‐recurrent meningiomas. The cumulative survival of patients with high SPARC expression was significantly lower than patients with low SPARC expression. The high SPARC expression scores were predominantly identified in meningothelial, fibrous and chordoid meningiomas; low SPARC expression scores were mostly spotted in secretory and psammomatous meningiomas. Evaluating SPARC expression might help assessing recurrence risk and survival estimation in meningiomas.     

Prognostic Significance of p27, Ki-67, and Topoisomerase lla Expression in Clinically Nonfunctioning Pancreatic Endocrine Tumors

Nonfunctioning islet cell tumors or pancreatic endocrine tumors are the most common type of malignant islet cell tumor. Although previously detected usually at an advanced stage because of mass effect, the early detection rate of small localized disease has been increasing. To date it has been difficult to predict the clinical behavior in localized regional nonfunctioning tumors. To investigate potential markers predicting malignancy and poor prognosis in nonfunctioning pancreatic endocrine tumors, we analyzed the expression of Ki-67, topoisomerase IIα (Topollα), and p27, as well as a variety of clinicopathologic parameters in 76 cases of nonfunctioning islet cell tumors (23 benign cases and 53 malignant cases). Ki-67, Topollα, and p27 labeling indices were significantly different between benign and malignant tumors. Expression of Ki-67, Topollα, and p27 were associated with survival in patients with a malignant tumor in a univariate setting. However, only p27 and Topollα were jointly associated with survival in multivariate analysis. Immunohistochemical staining for p27, Topollα, and Ki-67 can be helpful in the diagnosis of nonfunctioning pancreatic endocrine tumor. Analysis of p27 and Topollα may also have potential utility as prognostic factors for malignant tumors.     

Impact of p53 and Ki-67 in predicting recurrence and progression of superficial (pTa and pT1) urothelial cell carcinomas of urinary bladder

In predicting the aggressive behavior of bladder tumors, the histopathological characteristics of grade and invasive stage are of principal importance. However, for predicting tumor recurrence and progression, these are sufficient only to a limited extent, particularly in the case of superficial (pTa and pT1) urothelial cell carcinomas. New prognostic factors are therefore needed to avoid either insufficient or excessive treatment. In this retrospective study, we investigated the prognostic value of the p53 and Ki-67 immunoreactivity indices. The present study included 118 superficial urinary bladder tumors consisting of 58 recurrent and 60 non-recurrent cases. Twenty of the recurrent tumors progressed into a higher grade and/or invasive stage. Paraffin immunohistochemical analysis was carried out using anti-p53 and anti-Ki-67 antibodies on the initial tumor tissues. We concluded that there is a highly significant relationship between the p53 and Ki-67 immunoreactivities and the histological grade and pathological stage of the tumors (P < 0.0001). We observed a significant relationship between the presence of recurrence and progression and the p53 immunoreactivity index (P < 0.01 and P = 0.017, respectively) and Ki-67 immunoreactivity index (P < 0.0001 and P = 0.046, respectively). Positivity for p53 and Ki-67 can demonstrate the risk of recurrence (p53: sensitivity = 76%, specificity = 58%; Ki-67: sensitivity = 86%, specificity = 48%) and progression (p53: sensitivity = 80%, specificity = 46%; Ki-67: sensitivity = 85%, specificity = 36%; ). We believe that both of these immunohistochemical markers can be considered valuable in addition to classical histopathological prognostic parameters for predicting recurrence and progression risks.     

A role for chromosome 9p21 deletions in the malignant progression of meningiomas and the prognosis of anaplastic meningiomas

Meningiomas display significant variability in terms of recurrence and survival rates, even within tumor grade. Although several recent modifications of the grading system have improved our ability to predict biologic behavior, additional prognostic markers are needed. Inactivation of the cell cycle regulator, p16 (CDKN2A), has recently been observed in a small subset of atypical and the majority of anaplastic meningiomas. To assess the potential clinical utility of this marker, we performed dual-color FISH on 117 well-characterized archival meningiomas using paired commercial probes to the chromosome 9 centromeric (CEP9) and p16 (9p21) regions. Benign meningiomas (N = 42) were divided into non-recurring versus recurring groups. Atypical meningiomas (N = 52) consisted of proliferative and brain invasive subsets. The 23 anaplastic meningiomas were not further stratified. Deletion of p16 or monosomy 9 was seen in 17% of benign, 52% of atypical, and 74% of anaplastic meningiomas (p < 0.001). No statistically significant differences were found among subsets of benign or subsets of atypical meningioma, though there were more recurrences in those with deletion. Despite potential effects on cell cycle regulation, p16 deletions were not restricted to meningiomas with a high proliferative index. Most importantly, p16 deletion was strongly associated with survival in the anaplastic meningioma cohort, with a risk ratio for death of 6.79 (p = 0.016). Conversely, absence of deletion identified a subset of anaplastic meningioma patients (26%) with prolonged survival. We conclude that chromosome 9p21 deletions are associated with malignant progression of meningiomas and poor prognosis in anaplastic meningiomas.     

Correlation of enhanced cell turnover with prognosis of gastrointestinal stromal tumors of the stomach: relevance of cellularity and p27kip1

The aim of the present study was to determine whether expression of molecules associated with cell cycle regulation and apoptosis might reflect tumor grade and patients' prognosis of gastrointestinal stromal tumor (GIST). Forty-nine cases of gastric GIST were divided into three grades; low, intermediate, and high risk. Ki-67, cyclin A, cyclin D1, cyclin E, p16(Ink4), p21(Waf1), p27(Kip1), cyclin-dependent kinase (cdk)2, cdk4 and single-strand DNA (ssDNA) were immunohistochemically stained and assessed. Ki-67, ssDNA, cyclin A and cdk2 had higher labeling indices (LI) in high-risk than in low-risk cases. Cyclin E expression was greater in the intermediate- than in the low-risk grade. On Kaplan-Meier analysis, tumor size, necrosis, cellularity, Ki-67, ssDNA, and cyclin A LI were significantly correlated with disease-free survival. Necrosis, cellularity, and Ki-67 LI were significant as prognostic factors on univariate, and Ki-67 LI on multivariate Cox hazard tests. Within the high-risk grade, high cellularity and low p27(Kip1) subgroups had the worst prognosis. The histological grade is related to cell turnover, assessed in terms of Ki-67, ssDNA, cyclin A, cyclin E, and cdk2 levels. Ki-67, ssDNA, and cyclin A are useful for prediction of prognosis, with cellularity and p27(Kip1) expression as further prognostic factors in high-risk cases.     

Enhanced expression of Ki-67, topoisomerase IIα, PCNA, p53 and p21 reflecting proliferation and repair activity in UV-irradiated melanocytic nevi

To investigate the effect of ultraviolet (UV) irradiation on the expression of cell cycle-associated proteins, melanocytic nevi from healthy volunteers were partially covered, irradiated with a defined UV dose, and excised 1 week thereafter. The irradiated and the protected parts were examined separately by conventional microscopy and immunohistochemistry using the antibodies Ki-S11 (Ki-67), Ki-S7 (topoisomerase IIα), PC10 (proliferating cell nuclear antigen [PCna]), DO-7 (p53), 6B6 (p21^WAF1/Cip1), and the melanocytic marker HMB-45. DNA nick-end labeling was used as a marker of apoptosis. Irradiation resulted in morphological changes and increased HMB-45 reactivity. Proliferation, as assessed by Ki-67 and topoisomerase IIα expression, was also clearly enhanced in the UV-exposed areas. This was confirmed by the appearance of occasional mitotic figures. PCNA expression levels markedly exceeded those of the proliferation markers and did not correlate with the latter in most cases. p21 immunolabeling indices were also consistently augmented after UV exposure; hence it is likely that growth-inhibitory mechanisms partly compensate for the proliferative impulse, and the disproportional rise in PCNA expression probably reflects DNA repair activity. Enhanced p53 immunostaining in four cases suggests that the induction of p21 after irradiation may be p53 mediated, whereas no concomitant apoptotic events were observed. We conclude that UV light can stimulate the proliferative activity of melanocytes in melanocytic nevi, but that simultaneously cell cycle inhibitors are activated to permit DNA repair.     

Significant correlation of morphological remodeling in ulcerative colitis with disease duration and between elevated p53 and p21 expression in rectal mucosa and neoplastic development

Although a chronic inflammation-carcinoma sequence has been proposed in cases of longstanding ulcerative colitis (UC), the relationship of morphological alteration or remodeling of regenerated mucosa to carcinoma development is yet to be clarified. Therefore, mucosae of 49 resected rectae from individuals with UC were histologically and quantitatively analyzed, with regard to thickness and morphological parameters of crypts, in relation to the disease duration, clinical disease activity and neoplastic development. An immunohistochemical examination of Ki-67, p53, p21(WAF1) and ssDNA labeling was also included. Significant correlations of number, height, angle, fusion and Paneth cell metaplasia of crypts, as well as thickness of the muscularis mucosae, were revealed with disease duration, as confirmed by three-dimensional reconstructed image analysis. p53 and p21(WAF1)-positive cells increased with disease duration and were significantly more frequent in cases with neoplasia, suggesting more DNA damage. However, this was not the case for ssDNA labeling, assessed as an indicator of apoptosis. In general, histological changes and p53, p21(WAF1) and Ki-67 labeling were correlated. In conclusion, histological parameters for mucosal remodeling correlate well with UC duration, indicating accumulation of structural alterations. Accumulated damage to DNA, reflected by increased p53 and p21(WAF1) labeling indices, might be involved in cancer development, as well as longstanding inflammation.     

Correlation between histological grade, MIB-1, p53, and recurrence in 69 completely resected primary intracranial meningiomas with a 6 year mean follow-up

Sixty-nine intracranial, totally excised meningiomas were immunostained for MIB-1 and p53 protein expression. According to the 1993 WHO criteria, revised by Perry et al., the 69 meningiomas were classified into: grade I = 54 benign meningiomas, grade II = 10 atypical meningiomas, grade III = 5 malignant meningiomas. The patients were followed until death or for an average of 6.7 years. The 69 meningiomas were divided into two groups, according to the absence (n = 42) or presence (n = 27) of recurrences. In the last group we included 3 patients who died of meningioma recurrence. According to the percentage of MIB-1 positively stained cells, meningiomas were divided into three groups: <1% (n = 36), 1-10% (n = 28), >10% (n = 5). We found the MIB-1 labeling index (LI) <1% in 33 grade I (61%) and in 3 grade II (30%) meningiomas. On the other hand, 7 grade II (70%) and all grade III (100%) meningiomas presented a MIB-1 LI >1%. Correlation between histological grade and MIB-1 LI was statistically significant (p = 0.0006). The correlation between MIB-1 LI and follow-up was also highly significant (p < 0.001): the majority of meningiomas which did not recur (32/42 equal to 76%) were characterized by a low (<1%) MIB-1 LI. In the recurrence group MIB-1 LI was significantly higher than in the disease-free patients' group. Moreover, MIB-1 appeared to be a prognostic parameter not strongly related to the histological grade. In fact, it was significantly higher in recurrent histologically benign meningiomas, as compared with benign meningiomas without recurrence (p = 0.0006). Positive p53 protein expression (>1%) was shown in 26/45 meningiomas (57%), with an LI of 1-10% in 18 (40%) and an LI of >10% in 8 (17%) meningiomas. Although the p53 LI tended to be higher in atypical and malignant meningiomas, no significant correlation was found between the p53 expression and the recurrence (p = 0.05). The authors conclude that quantitative MIB-1 labeling is a useful technique in the routine diagnostic assessment of meningiomas, and helpful in obtaining more information about prognosis and thereby in planning the most suitable treatment.     

Osteopontin predicts the behaviour of atypical meningioma

Lin C‐K, Tsai W‐C, Lin Y‐C & Hueng D‐Y
(2012) Histopathology  60, 320–325
Osteopontin predicts the behaviour of atypical meningioma Aim: Although the World Health Organization (WHO) histological criteria distinguishing benign from atypical and malignant meningioma are clear, discerning benign from atypical meningioma is still somewhat difficult, leading to interobserver diagnostic variability. Osteopontin (OPN) and cortactin play important roles in tumorigenesis, invasion and metastasis of several human cancers. The aim of this study was to evaluate the usefulness of OPN and cortactin immunohistochemistry for distinguishing between benign, atypical and malignant meningioma and predicting their recurrence. Methods and results: Seventy‐five specimens (48 benign, 17 atypical and 10 malignant meningiomas) were investigated immunohistochemically. The mean immunohistochemical scoreimmunohistochemical score ± SE of the mean of both OPN and cortactin were significantly higher in grade II or grade III meningiomas than in grade I meningioma. Discriminant analysis of immunohistochemical OPN expression showed correct classification of 97.7% of WHO grade I meningiomas and 88.2% of WHO grade II meningiomas (95.4% accuracy). However, the same analysis of cortactin expression showed correct classification of 95.8% of WHO grade I meningiomas and only 23.5% of WHO grade II meningiomas (76.9% accuracy). A cut‐off for predicting grades I and II meningioma recurrence was determined for OPN (3.0) but not for cortactin. Finally, logistic regression identified both this cut‐off (P < 0.05) and WHO grade (P < 0.05) as independent risk factors for recurrence. Conclusions: OPN expression is a valuable marker for diagnosis of atypical meningioma and prediction of grades I and II meningioma recurrence.     

脑膜瘤P16^INK48、RB基因的甲基化分析及对基因表达的影响

目的 检测脑膜瘤中发生P16^INK48和RB基因甲基化的情况及对蛋白表达的影响。方法 用甲基化特异性聚合酶链反应对50例脑膜瘤进行了P16^INK48和RB的甲基化分析；并对其中的25例检测了P16^INK48蛋白的表达。结果 良性脑膜瘤中没有检测到甲基化，分别有6例ⅡⅢ级(37．5％)和4例Ⅲ级(28．6％)肿瘤发生至少一种基因的甲基化，其中有1例不典型脑膜瘤同时发生了两种基因的甲基化。全部13例P16^INK48阳性表达的肿瘤都是没有检测到甲基化者。结论 P16^INK48或RB的甲基化与不典型和间变性脑膜瘤的发生发展有关，其机制可能是甲基化使蛋白表达丢失并导致P16^INK48细胞周期蛋白D1／CDK4／RB途径功能障碍。     

Practical value of Ki-67 and p53 labeling indexes in stereotactic biopsies of diffuse and pilocytic astrocytomas

OBJECTIVE: Stereotactic biopsies are increasingly being used for the diagnosis and grading of astrocytomas, and there is a growing need to obtain maximum information from these tissue samples. In everyday practice, p53 protein and Ki-67 immunohistochemical analyses are the most frequently used ancillary studies to aid in diagnosis and grading, but their exact role is not clearly established. This study was undertaken to evaluate the practical value of these markers in stereotactic biopsy samples from diffuse astrocytomas as well as pilocytic astrocytomas. Methods/Results.-We analyzed the Ki-67 (MIB-1) and p53 labeling indexes in the stereotactic biopsy specimens from 11 pilocytic astrocytomas; 8 grade 2, 15 grade 3, and 16 grade 4 diffuse astrocytomas. Pilocytic astrocytomas and diffuse astrocytomas were evaluated as 2 separate groups. There was a strong correlation with poor outcome when both labeling indexes were higher than 15% in the same tumor for diffuse astrocytomas (P < 0.01). The indexes did not correlate with outcome in pilocytic astrocytomas. CONCLUSION: Combined Ki-67 and p53 labeling indexes higher than 15% indicated a worse outcome than suggested by the histologic grading. The analysis aided or improved histologic evaluation of stereotactic biopsies in our patients. We believe that a realistic prognostic upgrading of diffuse astrocytomas should be made only when labeling indexes for both markers are greater than 15%.     

Differential expression of p16/p21/p27 and cyclin D1/D3, and their relationships to cell proliferation, apoptosis, and tumour progression in invasive ductal carcinoma of the breast

In order to understand the intricate relationship of cell proliferation and apoptosis in tumour development, proliferation markers (Ki-67 and c-myc), apoptosis, cell-cycle inducers cyclin D1 and D3, and cell-cycle inhibitors p16(INK4), p21(CIP1), and p27(KIP1) were evaluated in ductal breast carcinoma. The heterogeneous nature of breast tumours provides a system by which the changes in cell-cycle genes can be explored under a wide range of proliferation and apoptotic indices. To address the above issues, immunohistochemical studies were conducted in 40 pairs of tumours and adjacent normal ductal tissues. The TUNEL method was used to identify apoptotic cells. Except for p27/KIP1, the proliferation (Ki-67, c-myc) and the apoptotic indexes together with levels of p16/INK4a, p21/CIP1, cyclin D1, and cyclin D3, were clearly elevated among tumour tissues, while absent in the adjacent normal tissues. Spearman correlation analysis indicated strong associations among apoptotic index, Ki-67, c-myc, and tumour grade. In addition, p21/CIP1 and cyclin D3 were positively correlated, while p16/INK4a, p27/KIP1, and cyclin D1 were negatively correlated with tumour grade. There was clear decoupling between p21 and p27, as well as decoupling between cyclin D1 and cyclin D3, in terms of their relationship to cell proliferation and apoptosis, indicating differential roles in tumour progression.