Immunohistochemical Markers for Prognosis of Oligodendroglial Neoplasms

Despite numerous previous studies, oligodendrogliomas continue to generate considerable controversy in the identification of prognostic factors, including single histopathological patterns, and grade of tumor malignancy. The prognostic significance of various pathological and immunohistochemical factors has been intensively examined but numerous studies have yielded conflicting results. In the present study, biopsy samples of 123 oligodendrogliomas were examined immunohistochemically to evaluate a possible association between expression of various tumor-associated antigens and clinical outcome. Both the progression-free and overall survival times were significantly reduced for high-grade tumors, for Ki-S1 labeling index (LI)>10%, for p27 LI<20% and for p18, p53, and vascular endothelial growth factor (VEGF)-positive tumors. For low-grade tumors survival rates were significantly reduced for p27 LI less than 20%, whereas high-grade oligodendrogliomas with Ki-S1 LI greater than 10%, and with p18 positivity revealed significantly shortened survival times. We found no differences in survival times in patients with or without p14ARF, p21, mdm2, and pRb immunoreactivity. Multivariate analysis revealed that risk of oligodendroglioma progression is associated with high-grade tumors, with Ki-S1 LI>10%, and with p27 LI<20%; whereas risk of death is associated with high-grade tumors, with Ki-S1 LI>10%, and with p18 positivity. CART modeling process identified four final groups of oligodendroglioma patients: (1) thirty-nine patients with low-grade tumors and p27 LI>20%; (2) twenty patients with low-grade tumors and p27 LI<20%; (3) thirty-four patients with high-grade tumors and Ki-S1 LI<10%; and (4) thirty patients with high-grade tumors and Ki-S1 LI >10%. In summary, both the p27 and Ki-S1 scores were found to be the strong predictors of oligodendroglioma outcome together with the WHO tumor grade and they seem to be useful for assessing individual prognosis in routinely processed specimens.     

Prognostic value of Ki-67 (MIB-1) and p53 in ependymomas

To determine whether Ki-67 (MIB-1) and p53 have prognostic value in ependymomas, clinicopathologic study was undertaken in 29 patients with this tumor. The clinical course correlated well with the histological grade according to the World Health Organization (WHO) grading system, and it was the worst in patients with anaplastic ependymoma. The percent expression of MIB-1 and p53 correlated with the histological grade of malignancy. With regard to the subtypes of benign ependymoma, the clinical course was the worst in clear-cell ependymoma, which had a significantly higher expression of MIB-1 and p53 than the other subtypes. Tanycytic ependymoma showed the most benign clinical course and the lowest expression of MIB-1 and p53. Although the WHO grading generally tended to correlate with the clinical course of ependymomas, these two subtypes-clear-cell ependymoma and tanycytic ependymoma-exhibited biological properties different from those of other grade II ependymomas.     

Postoperative radiotherapy of intracranial ependymoma in pediatric and adult patients

In 33 patients undergoing operation and postoperative irradiation for intracranial ependymomas between January 1963 and December 1983, the tumor was grade 1 or 2 in 26 (79%) patients and grade 3 or 4 in 7 (21%). Operation consisted of only biopsy in 1 (3%), subtotal removal of tumor in 28 (85%), and gross total resection in 4 (12%). All patients received brain irradiation with a median dose of 4800 cGy. Seventeen (52%) patients also received spinal axis irradiation (median dose, 3000 cGy) which included 5 with high-grade tumors and 12 with low-grade infratentorial tumors. The relapse-free and overall survival rates at 5 years were 61% and 62%, respectively. Prognostic factors analyzed for statistically significant survival differences included age, sex, hydrocephalus, site, grade, extent of operation, extent of brain field, spinal axis irradiation, and brain dose. Grade was the only significant factor found: the 5-year survival of patients with low-grade ependymomas, 71%, was significantly better (p less than 0.04) than that of patients with high-grade ependymomas, 29%. Among the 31 patients evaluable for patterns of failure, treatment failed in 12 (39%) (10 only in the brain, 1 in the brain and spinal cord, and 1 only in the spine). All but one of the brain failures were at the site of the original primary lesion. Treatment failed in 4 of the 6 (67%) patients with high-grade tumor but in only 8 of the 25 (32%) with low grade tumor. Among the 7 low-grade infratentorial ependymomas treated with brain irradiation only, there was 1 treatment failure (in the spine; salvaged with further irradiation). Among the 12 patients with low-grade infratentorial tumors who received spinal axis irradiation, treatment failed in 1 (8%) (in the spine and also in the brain; patient subsequently died of disease). Nineteen (58%) patients remain alive; all but 2 of the patients who had recurrence died of their disease. This retrospective study suggests that: (a) patients with high-grade tumors have significantly poorer survival compared with those with low-grade tumors; (b) the main cause of death in ependymoma patients is intracranial failure at the primary site; and (c) craniospinal axis irradiation may not be necessary for patients with low-grade infratentorial ependymoma (localized irradiation alone may be adequate).     

Mutational analysis of the PTEN gene in gliomas: molecular and pathological correlations

The PTEN gene, recently identified on chromosome 10q23, has been proposed to be a candidate tumor suppressor gene inactivated in multiple cancers including glial tumors. We investigated 47 glioblastomas (GBM), 14 anaplastic astrocytomas (AA), 6 non-pilocytic low-grade astrocytomas (LGA), 21 low-grade and anaplastic oligodendrogliomas (O) and oligoastrocytomas (OA), and 3 ependymomas (E) for mutation of the PTEN gene using denaturing gradient gel electrophoresis (DGGE) followed by DNA sequencing. These tumors have been previously screened for loss of heterozygosity (LOH) on chromosome 10q, p53 mutations and EGFR amplification. Overall, PTEN mutations, detected in 14 of 91 tumors, were present in 13 of 47 GBM and 1 of 14 AA. In contrast, mutations were absent in other glioma subtypes (0/30). In all informative cases, PTEN mutations occurred in tumors showing LOH on chromosome 10q, confirming the inactivation of this gene by a 2-hit mechanism. No correlation was observed between the presence of PTEN mutation and p53 mutation and EGFR amplification. Our results indicate that biallelic PTEN inactivation plays an important role in the pathogenesis of high-grade astrocytomas as a late event. Moreover, they suggest that PTEN alterations are equally involved in the 2 glioblastoma pathways defined by the presence of EGFR amplification and p53 mutation. Finally, correlation analysis with clinical data did not show that PTEN mutation was linked to survival of the patients.     

Histological spectrum of ependymomas and correlation of p53 and Ki-67 expression with ependymoma grade and subtype

BACKGROUND: Clinical and histological criteria for ependymoma prognosis are well recognized. Recently few studies have been done based on Immunohistochemistry for prognostication of these tumours. In this study we have correlated the histological spectrum with immmunoexpression of p53 and Ki67 in these tumors. AIMS: To know the incidence of ependymomas; study their morphological spectrum and to evaluate expression of P53 and Ki 67 in different morphological subtypes. MATERIAL AND METHOD: A retrospective study was preformed on 70 ependymomas received in a period between 1994 and 2001. Entire tissue received was processed for routine paraffin embedded H&E stained sections. Immunocytochemistry was performed using antibodies to GFAP, EMA, Pancytokeratin and synaptophysin, to differentiate papillary ependymoma from choroid plexus papilloma; clear cell ependymoma from oligodendroglioma and central neurocytoma; ependymoblastoma from other embryonal tumours. p53 and Ki-67 immunohistochemistry was performed to correlate their expression with various tumour grades and subtypes. RESULTS: There were 3 cases (4.2%) of Grade I ependymoma (2 cases of myxopapillary ependymoma and 1 case of subependymoma); 57 cases (81.5%) of ependymoma grade II (43 of these were of classical variety, 11 of clear cell ependymoma, 2 of papillary and 1 case of cellular ependymoma). There were 9 cases (12.8%) of anaplastic ependymoma (one of these was a clear cell ependymoma and 1 case (1.5%) of ependymoblastoma CONCLUSION: p53 and Ki67 indices can be used in routine diagnostic laboratories to supplement the tumor grade on histology and more studies with follow up should be performed to analyse the prognosis of different subtypes. The expression of Ki 67 and p53 was significantly higher in anaplastic ependymomas. 4 out of 11 cases of clear cell ependymomas showed higher Ki 67 indices as compared to classical grade II ependymomas, thus further highlighting the importance of differentiating the various subtypes.     

诱导型一氧化氮合酶在反应性及肿瘤性星形胶质细胞中的表达

目的:探讨诱导型一氧化氮合酶(iNOS)、突变型p53及VEGF在反应性及肿瘤性星形胶质细胞中的表达及其在星形胶质细胞瘤发生发展、血管形成中的作用。方法:应用组织芯片及免疫组织化学技术检测12例正常脑组织、49例星形细胞反应性增生、49例低级别(I-II级)及50例高级别(III-IV级)星形胶质细胞瘤中iNOS、突变型p53、VEGF表达情况。结果:在正常脑组织中三者均为阴性表达;从星形细胞反应性增生组到高级别星形细胞瘤组,三者的阳性表达率均呈升高趋势,分别为:iNOS:28.89%(13/45),57.75%(27/47),81.63%(40/49);p53:23.81%(10/42),53.66%(22/41),79.55%(35/44);VEGF:22.73%(10/44),44.19%(19/43),69.77%(30/43),并且三者在星形细胞反应性增生组及低级别星形胶质细胞瘤组中的表达差异显著(P<0.05);各实验组中iNOS与p53表达水平一致性较好,具有明显的相关性(P<0.05);而iNOS与VEGF在低级别及高级别星形胶质细胞瘤组中表达水平具有较好的一致性及明显的相关性(P<0.05),在反应性增生组表达无相关性(P>0.05)。结论:iNOS、突变型p53及VEGF的过表达是胶质瘤发生的早期分子生物学事件,三者相互作用共同促进星形胶质细胞瘤的发生发展及血管的形成;单一或联合检测可能有助于星形细胞反应性增生及低级别星形细胞瘤的鉴别诊断。     

Detection of apoptotic cells and immunohistochemical study of bcl-2 and p53 gene protein in primary gastric mucosa-associated lymphoid tissue (MALT) lymphoma

In recent years, the study of apoptosis has become one of the hot subjects for cancer research. Recent research revealed that apoptosis might be associated with tumor initiation and development, cancer therapy and prognosis. A lot of genes have been found to involve in the apoptotic process, especially the p53 and bcl-2 gene. The mucosa associated lymphoid tissue type lymphoma (MALToma) is a sort of extra-nodal low-grade malignant lymphoma, which is different from primary nodal lymphomas in …     

CDKN2A/p16 in ependymomas

Sixteen cases of ependymoma were studied for CDKN2A/p16 inactivation by immunohistochemistry using a p16 monoclonal antibody, by homozygous deletion (HD) assay and 5CpG promoter methylation assay (methylation-specific PCR). Three out of 16 cases were p16 immuno-negative: two corresponded to grade II ependymomas and one to grade III. The latter ependymoma, characterized by a high Ki-67/MIB-1 LI, was the only one of the whole series to show CDKN2A HD. No promoter methylation was found in the two immuno-negative cases without CDKN2A HD. Alternative mechanisms, such as point mutations or alterations in p16 post-translational regulation, may be responsible for p16 inactivation. Since in our series just one out of eight anaplastic cases showed negative immunostaining and CDKN2A HD, p16/CDKN2A inactivation may not play an important role in the malignant transformation of ependymomas.Amplification of CCND1 and CDK4, p27/Kip1 degradation and TP53 mutations were previously studied by other authors and were demonstrated not to correlate with anaplasia. Up to date, molecular genetic studies have not been useful in recognizing the anaplastic variant in ependymomas.     

Infrequency of p53 gene mutations in ependymomas

Summary Ependymomas, which comprise 5% of central nervous system tumors, have not been extensively characterized genetically. The p53 tumor suppressor gene is frequently mutated in human cancer, and is important in the pathogenesis of other central nervous system (CNS) tumors. Chromosomal DNA corresponding to the p53 tumor suppressor gene was amplified by the polymerase chain reaction (PCR) from 31 archival ependymoma specimens. DNA was screened for the presence of p53 mutations by single strand conformational polymorphism (SSCP) analysis; samples with altered mobility were further tested for the presence of mutation by direct DNA sequence analysis. Of the 31 ependymomas tested, one contained a detectable DNA sequence change in the p53 gene. Sequencing revealed a silent mutation in exon 6, at codon 213, which represents a known p53 sequence polymorphism. These findings suggest that in contrast to many other human cancers, p53 mutation is not important in the pathogenesis or progression of ependymomas.     

Epidermal growth factor receptor and Ink4a/Arf: convergent mechanisms governing terminal differentiation and transformation along the neural stem cell to astrocyte axis

Ink4a/Arf inactivation and epidermal growth factor receptor (EGFR) activation are signature lesions in high-grade gliomas. How these mutations mediate the biological features of these tumors is poorly understood. Here, we demonstrate that combined loss of p16(INK4a) and p19(ARF), but not of p53, p16(INK4a), or p19(ARF), enables astrocyte dedifferentiation in response to EGFR activation. Moreover, transduction of Ink4a/Arf(-/-) neural stem cells (NSCs) or astrocytes with constitutively active EGFR induces a common high-grade glioma phenotype. These findings identify NSCs and astrocytes as equally permissive compartments for gliomagenesis and provide evidence that p16(INK4a) and p19(ARF) synergize to maintain terminal astrocyte differentiation. These data support the view that dysregulation of specific genetic pathways, rather than cell-of-origin, dictates the emergence and phenotype of high-grade gliomas.     

p14ARF protein expression is a predictor of both relapse and survival in squamous cell carcinoma of the anterior tongue.

PURPOSE: The INK4A-ARF locus at chromosome 9p21 is frequently altered in head and neck squamous cell carcinoma (SCC) and encodes two distinct tumor suppressors, p16(INK4A) and p14(ARF). This study addressed the role of p14(ARF) as a potential prognostic marker in this disease. EXPERIMENTAL DESIGN: p14(ARF) protein expression was assessed by immunohistochemistry in a cohort of 140 patients with SCC of the anterior tongue. Using univariate and multivariate Cox's proportional hazards models, the outcomes examined were time to disease recurrence or death, with or without clinicopathologic covariates, including nodal status, disease stage, treatment status, Ki-67 staining, and molecular markers with known functional or genetic relationships with p14(ARF) (p16(INK4A), p53, pRb, p21(WAF1/CIP1), E2F-1). RESULTS: On multivariate analysis, p14(ARF) positivity (nucleolar p14(ARF) staining and/or nuclear p14(ARF) staining in >/=30% of tumor cells) was an independent predictor of improved disease-free survival (DFS; P = 0.002) and overall survival (OS; P = 0.002). This was further enhanced when p14(ARF) positivity was cosegregated with positive (>/=1%) p16(INK4A) staining (DFS, P < 0.001; OS, P < 0.001). Patients whose cancers were p14(ARF) negative and p53 positive (>50%) had the poorest outcome (DFS, P < 0.001; OS, P < 0.001) of any patient subgroup analyzed. CONCLUSIONS: These data show that in patients with SCC of the tongue, combined nuclear and nucleolar expression of p14(ARF) protein predicts for improved DFS and OS independent of established prognostic markers.     

Vascular endothelial growth factor and glioma angiogenesis: Coordinate induction of VEGF receptors,distribution of VEGF protein and possible In vivo regulatory mechanisms

We have previously suggested that tumor angiogenesis in human gliomas is regulated by a paracrine mechanism involving vascular endothelial growth factor (VEGF) and flt-I (VEGF-receptor I). VEGF, an endothelial-cell-specific mitogen, is abundantly expressed in glioma cells which reside along necrotic areas, whereas fit-I, a tyrosine-kinase receptor for VEGF, is expressed in tumor endothelial cells, but not in endothelial cells in normal adult brain. Recently, a second tyrosine-kinase receptor which binds VEGF with high affinity, designated KDR or flk-I, has been described. We performed in situ hybridization for VEGF mRNA, flt-I mRNA and KDR mRNA on serial sections of normal brain, low-grade and high-grade glioma specimens. We show that KDR mRNA is co-expressed with flt-I in vascular cells in glioblastoma but not in low-grade glioma. Since flt-I and KDR are not expressed in endothelial cells in the normal adult brain, the coordinate up-regulation of 2 receptors for VEGF appears to be a critical event which controls tumor angiogenesis. Immunocytochemistry with a monoclonal anti-VEGF antibody revealed significant amounts of VEGF protein in the same glioma cells that expressed VEGF mRNA. The largest amount of VEGF immunoreactivity, however, was detected on the vasculature of glioblastomas, the site where VEGF exerts its biological functions. These findings suggest that VEGF is produced and secreted by glioma cells and acts on tumor endothelial cells which express VEGF receptors. To further characterize VEGF-producer cells in vivo, we investigated cellular proliferation, immunoreactivity to the p53 tumor-suppressor gene product and epidermal-growth-factor-receptor(EGFR) expression on serial sections by immunocytochemistry. VEGF-producer cells did not show increased cellular proliferation, p53 immunoreactivity or EGFR immunoreactivity as compared with glioma cells which did not express VEGF. Our studies therefore do not demonstrate evidence for a growth advantage of VEGF-producer cells in vivo or VEGF induction by p53 mutation or EGFR over-expression. © 1994 Wiley-Liss, Inc.     

Deregulation of the TP53/p14ARF tumor suppressor pathway in low-grade diffuse astrocytomas and its influence on clinical course.

PURPOSE: The chromosome 9p21 region harbors three tumor suppressor genes, p14(ARF), p15(INK4b), and p16(INK4a), all of which can be targets for hypermethylation-associated inactivation in low-grade gliomas. p16(INK4a) and p15(INK4b) are critically involved in the RB1 pathway, whereas p14(ARF) acts as an upstream regulator of the TP53 pathway. The role of each tumor suppressor pathway in low-grade diffuse astrocytomas and their relationships with clinical behavior remain to be elucidated. EXPERIMENTAL DESIGN: We assessed the alterations of the RB1/CDK4/p16(INK4a)/p15(INK4b) and the TP53/MDM2/p14(ARF) pathways in 46 WHO grade II astrocytomas and analyzed their impact on prognosis. RESULTS: The TP53/MDM2/p14(ARF) pathway was altered in 32 of 46 cases (70%) by either TP53 mutation (25 cases) or p14(ARF) methylation (9 cases). The RB1/CDK4/p16(INK4a)/p15(INK4b) pathway was disrupted in 6 of 46 cases (13%) by either RB1 methylation (1 case), p16(INK4a) methylation (3 cases), or p15(INK4b) methylation or homozygous deletion (3 cases). Generally speaking, individual tumors thus tended to display alteration of only one component from both pathways. Any independently analyzed genetic alteration failed to provide statistically prognostic information. The alternate or simultaneous presence of TP53 mutation and p14(ARF) methylation emerged as a univariate predictor of a shorter progression-free survival (P = 0.0456) but was not statistically significant when age and extent of surgery were included in the analysis. CONCLUSIONS: Alternative disruption of the TP53/p14(ARF) pathway represents a frequent event in low-grade diffuse astrocytomas and correlates with an unfavorable clinical course. However, its value is unlikely to include prognostic utility that is independent of other conventional prognostic factors.     

4-Fluoro-N-butylphenylacetamide: a synthetic phenylacetate derivative that upregulates Bcl-X(S), activates caspase cascade and induces apoptosis in human squamous lung cancer CH27 cells

The CDKN2A locus on human chromosome 9p21 encodes two proteins, p16 and p14ARF, that mainly regulate cell cycle progression and cell survival via the pRb and p53 pathways, respectively. Germline mutations in CDKN2A have been linked to development of cutaneous melanoma in some families with hereditary melanoma. Due to overlapping open reading frames in exon 2, some mutations in this exon affect both p16 and p14ARF. We previously reported a 24 bp deletion in CDKN2A exon 2 in a patient with multiple primary melanomas and melanoma heredity. To further clarify the possible role of the 24 bp deletion for melanoma development, especially with respect to p14ARF, we have studied the cellular distribution and function of the resulting p14ARF del (77–84) and p16 del (62–69) mutant proteins. We found that p14ARF del (77–84) had decreased nucleolar localization, and was less efficient than wt p14ARF in stabilizing p53, inducing G1 cell cycle arrest, and inhibiting colony formation. The p16 del (62–69) mutant localized predominantly to the cytoplasm, did not induce G1 cell cycle arrest, and failed to suppress colony formation. We conclude that p14ARF del (77–84) has retained the ability to stabilize MDM2 and p53, but that it is less potent than wt p14ARF. This partial functional defect may complement the clearly defective p16 del (62–69) mutant and thus contribute to melanoma development in patients carrying the 24 bp deletion in CDKN2A.     

The results of radiotherapy for ependymomas: the mayo clinic experience

Purpose: This analysis was performed to examine the outcome of patients with histologically confirmed ependymomas of the brain or spinal cord who received postoperative radiotherapy.

Methods and Materials: Eighty patients with histologically confirmed ependymomas were evaluated retrospectively. All were treated with various combinations of surgery, radiotherapy (RT), and chemotherapy. Follow-up ranged from 5 to 30 years (median 10.4 years).

Results: The 5- and 10-year survival rates for the entire study group were 79% and 73%, respectively. Patients with low-grade (1 and 2 of 4) tumors had a 5-year survival rate of 87% as compared to 27% for those with high-grade (3 and 4 of 4) tumors (p < 0.0001). Patients with tumors of the spine had a 5-year survival rate of 97% as compared to 68% for those with infratentorial tumors, and 62% for those with supratentorial tumors (p = 0.03). Patients with myxopapillary ependymomas of the spine had a 5-year survival rate of 100% as compared with 76% for patients with other histological subtypes of ependymoma (p = 0.02). Multivariate analysis revealed that the survival rate was independently associated with tumor grade (p = 0.0007) and histological subtype (p = 0.02). Twenty-eight patients (35%) experienced local failure and 10 patients (13%) developed leptomeningeal seeding. The 5-year leptomeningeal failure rate was 10% in patients with low-grade tumors as compared to 41% for patients with high grade tumors (p = 0.01).

Conclusion: Patients with low-grade tumors, especially those with myxopapillary subtypes, have high 5-year survival rates when treated with post-operative radiotherapy. High grade ependymomas are associated with a much poorer outcome. New forms of therapy are required to improve the outcome of patients with high-grade ependymomas.     

Analysis of Ki-67, p53 and Bcl-2 expression in the dysplasia-carcinoma sequence of Barrett's esophagus.

The grading of dysplasia in Barrett's esophagus has prognostic importance, however observer variation limits the reliability of simple histological analysis alone. We investigated Ki-67, p53 and Bcl-2 expression in Barrett's esophagus, in the sequence from Barrett's low-grade dysplasia to high-grade dysplasia and infiltrating adenocarcinoma. Forty-four esophagectomy specimens were utilized: 39 specimens with esophageal dysplasia and adenocarcinoma and 5 specimens with esophageal dysplasia only. This gave 83 sections (2 sections for specimens with dyplasia and carcinoma) examined from 44 patients. The sections were examined for Ki-67, p53 and Bcl-2 reactivity by immunohistochemistry. Low-grade dysplasia was present in 14 sections, high-grade dysplasia in 30 sections and carcinoma in 39 sections. Ki-67 expression occurred in 2 out of 14 (14%) sections with low-grade dysplasia, in 22 out of 30 (73%) sections with high-grade dysplasia and in 34 out of 39 (87%) sections with carcinoma (p<0.001). p53 protein expression was found in 1 of 14 (7%) sections with low-grade dysplasia, in 18 of 30 (60%) sections with high-grade dysplasia and in 33 of 39 (85%) sections with carcinoma (p<0.001). Expression of Bcl-2 was found in 11 of 14 (84%) sections with low-grade dysplasia but immunoreactivity was not seen in any section with high-grade dysplasia or Barrett's carcinoma. Our results indicate that overexpression of Ki-67, Bcl-2 protein and p53 mutations can be identified as early events during neoplastic progression in Barrett's esophagus. These data support the hypothesis that, in the progression of Barrett's metaplasia to adenocarcinoma, the balance of proliferation/apoptosis plays an important role.     

HCV C蛋白、p53、Mdm2、p14和p21在原发性肝癌中的表达及相关性

目的:研究原发性肝癌(HCC)组织中核心蛋白、突变p53、Mdm2、p14和p21的表达及其相关性,探讨HCV核心蛋白对突变p53、Mdm2、p14和p21表达影响及临床意义。方法:收集42例HCC石蜡组织,采用免疫组织化学EnVision法检测HCC组织中核心蛋白、突变p53、Mdm2、p14和p21的表达,用统计学方法及临床联系分析它们之间的关系。结果:核心蛋白、突变p53、Mdm2、p14和p21的阳性表达主要定位于细胞核中;HCC组织中核心蛋白、突变p53、Mdm2、p14和p21阳性率分别为40.5%、47.62%、75.57%、45.24%、19.05%;5组间的Kruskal-Wallis检验P=0.000,差异显著,核心蛋白与突变p53、Mdm2、p14和p21间的Mann-WhitneyU秩和检验P值分别为0.043、0.009、1.0、0.023;HCVC蛋白与突变p53、p14、p21阳性强度两者间相关性Spearman检验P值分别为0.000、0.000、0.43,相关系数rs分别为0.67、0.64、-0.29;p53和Mdm2、p21阳性强度间相关性Spearman检验p值为0.000、0.174,rs分别为0.72、-0.45。结论:在HCV感染的HCC中HCVC蛋白可能促进野生p53突变和表达,p14的表达与C蛋白有关联;突变p53和p14很可能促进Mdm2的表达;HCC中p21表达缺陷是十分常见的,HCV相关的HCC主要与p53通路改变有关,C蛋白可能下调p21的表达。因此,HCV相关的HCC中C蛋白、突变p53、Mdm2很可能促进肝细胞增生或恶性生长。     

Detection of genetic alterations in the p53 suppressor gene and the K-ras oncogene among different grades of dysplasia in patients with colorectal adenomas

BACKGROUND: Although it is believed that p53 suppressor gene mutations, compared with mutations in the K-ras oncogene, occur at a later stage of colorectal tumorigenesis, the distribution of these genetic alterations at an early stage remains poorly characterized. METHODS: The authors analyzed the immunoreactivity for p53 protein (p53 protein expression), which reflects the functionally altered p53 gene, and K-ras mutations at codons 12 in 68 colorectal adenomas with both low-grade and high-grade dysplasia obtained from 62 patients. RESULTS: The prevalence of p53 positive immunostaining was significantly greater compared with the prevalence of K-ras mutations both in low-grade dysplasia and in high-grade dysplasia. Twenty-two adenomas (32.3%) showed positive immunostaining for p53 protein in high-grade dysplasia and also were positive for p53 in surrounding low-grade dysplastic tissues; 20 adenomas (29.4%) showed positive immunostaining for p53 protein in high-grade dysplasia and were negative for p53 in surrounding low-grade dysplastic tissues; 8 adenomas (11.7%) showed negative immunostaining for p53 protein in high-grade dysplasia and were positive for p53 in surrounding low-grade dysplastic tissues; and 18 adenomas (26.4%) showed negative immunostaining for p53 protein in both high-grade dysplasia and in surrounding low-grade dysplastic tissues. On the whole, a significant difference (P < 0.05) was seen in the frequency of p53 positive immunostaining between low-grade dysplasia and high-grade dysplasia (44.1% and 61.8%, respectively) but not in that of K-ras mutations (20.3% and 23.4%, respectively). CONCLUSIONS: The results of this study suggest that mutation of the p53 suppressor gene occurs earlier in the adenoma-carcinoma sequence than K-ras mutation, providing a clue for further understanding of the role of the p53 gene in the early stage of colorectal tumorigenesis.     

TP53, p14ARF,p16INK4a and H-ras gene molecular analysis in intestinal-type adenocarcinoma of the nasal cavity and paranasal sinuses

Intestinal-type adenocarcinoma (ITAC) of the nasal cavity and paranasal sinuses is an uncommon tumor associated with occupational exposure to dusts of different origin. Few investigations addressed molecular alterations in ITAC mainly focused on TP53, K-ras and H-ras gene mutations. The occurrence of TP53, p14(ARF) and p16(INK4a) deregulation and H-ras mutations was investigated in 21 consecutive and untreated ITACs cases, 17 with known professional exposure. No H-ras mutations were found. In patients with known exposure, cumulative evidence of TP53 or p14(ARF) alterations accounted for 88% and the evidence of p16(INK4a) alterations for 65%, respectively. TP53 mutations were present in 44% of the ITACs, consisted of G:C-->A:T transitions in 86%, and involved the CpG dinucleotides in 50% of the cases. LOH at the locus 17p13 and an uncommon high rate of p53 stabilization were detected in 58% and 59% of the cases, respectively. p14(ARF)and p16(INK4a) promoter methylation accounted for 80% and 67% respectively, and LOH at the locus 9p21 occurred in 45% of the cases. Interestingly, all dust-exposed tumors with p16(INK4a) alterations shared TP53 or p14(ARF) deregulation. The present results show a close association of this occupational tumor with TP53, p14(ARF) and p16(INK4a) gene deregulation. Given the important role that these genes play in cell growth control and apoptosis, the knowledge of ITAC genetic profile may be helpful in selecting more tailored treatments.     

分子标志物在高级别胶质瘤患者预后评估中的价值

目的:探讨分子标志物在高级别胶质瘤患者预后评估中的价值。方法:收集2010年09月至2015年07月之间经我院收治的高级别胶质瘤患者31例,免疫组织化学染色检测患者肿瘤组织中Ki-67、6-氧-甲基鸟嘌呤-DNA甲基转移酶（MGMT）、表皮生长因子受体（EGFR）、p53和基质金属蛋白酶-9（MMP-9）的表达;电话及门诊随访患者生存状况,分析上述分子标志物在高级别胶质瘤患者预后评估中的价值。结果:Ki-67和MGMT高表达患者的PFS明显低于低表达患者（P＜0.05）,但MMP-9、EGFR和p53表达水平与PFS间未见明显相关性（P＞0.05）。多因素分析发现Ki-67是影响PFS的独立预后因素(RR=5.19,P＜0.05)。结论:Ki-67是影响高级别胶质瘤患者PFS的独立危险因素,在预后评估中可能具有潜在的应用价值。