散发性大肠癌组织及粪便脱落细胞p53蛋白的检测

为了解大肠癌组织及粪便脱落细胞中 p5 3蛋白表达对大肠癌诊断的临床意义 ,采用 S- P法对 38例大肠癌患者的癌组织及其中的 30例患者的粪便脱落细胞 p5 3蛋白进行检测。大肠癌组织中 p5 3蛋白阳性表达率为 39.47% (15 / 38) ,p5 3蛋白阳性与癌组织的分化程度及是否存在淋巴结转移均无相关性 (P>0 .0 5 )。粪便脱落细胞 p5 3蛋白阳性表达率为 36 .6 7%(11/ 30 ) ,脱落细胞与相应患者的癌组织中的 p5 3表达一致率为 83.33% (2 5 / 30 )。表明粪便中脱落细胞 p5 3蛋白的表达忠实反映了相应癌组织的 p5 3突变情况 ,对其检测有望成为大肠癌诊断及筛查的无创分子途径。同时表明粪便中脱落细胞核保持了肿瘤抗原决定簇的主要结构及生物特征 ,进行免疫细胞化学检测是可行的 ,为进行脱落细胞核其它肿瘤标志物或其它生物研究奠定了可行性的基础     

A novel mechanism of non-Aβ component of Alzheimer's disease amyloid (NAC) neurotoxicity. Interplay between p53 protein and cyclin-dependent kinase 5 (Cdk5)

The non-Aβ component of Alzheimer's disease (AD) amyloid (NAC) is produced from the precursor protein NACP/α-synuclein (ASN) by till now unknown mechanism. Previous study showed that like ASN, NAC peptide induced oxidative/nitrosative stress and apoptosis. Our present study focused on the mechanisms of PC12 cells death evoked by NAC peptide, with particular consideration on the role of p53 protein. On the basis of molecular and transmission electron microscopic (TEM) analysis it was found that exogenous NAC peptide (10 μM) caused mitochondria dysfunction, enhanced free radical generation, and induced both apoptotic and autophagic cell death. Morphological and immunocytochemical evidence from TEM showed marked changes in expression and in translocation of proapoptotic protein Bax. We also observed time-dependent enhancement of Tp53 gene expression after NAC treatment. Free radicals scavenger N-tert-butyl-alpha-phenylnitrone (PBN, 1 mM) and p53 inhibitor (α-Pifithrin, 20 μM) significantly protected PC12 cells against NAC peptide-evoked cell death. In addition, exposure to NAC peptide resulted in higher expression of cyclin-dependent kinase 5 (Cdk5), one of the enzymes responsible for p53 phosphorylation and activation. Concomitantly, we observed the increase of expression of Cdk5r1 and Cdk5r2 genes, coding p35 and p39 peptides that are essential regulators of Cdk5 activity. Moreover, the specific Cdk5 inhibitor (BML-259, 10 μM) protected large population of cells against NAC-evoked cell death. Our findings indicate that NAC peptide exerts its toxic effect by activation of p53/Cdk5 and Bax-dependent apoptotic signaling pathway.     

Study of P53 protein expression in colorectal cancer

Mutations of the P53 gene, strictly associated with the carcinogenesis are a commonly observed in neoplastic cells. The aim of this study was the immunohistochemical evaluation of P53 protein expression in colorectal carcinomas and analysis of its relationship to chosen anatomo-clinical and morphological parameters of the tumours. The study used the material obtained during surgical treatment of 74 colorectal carcinomas. Tissue sections were fixed in 10% buffered formaldehyde solution, embedded in paraffin and stained immunohistochemically with the antihuman P53 protein monoclonal antibody. The immunolocalization of P53 protein was performed using the Labelled Streptavidin Biotin (LSAB) method. The P53 protein expression was semiquantitatively assessed in neoplastic cells and the reaction present in more than 25% of tumour cells was accepted as the threshold of positivity. No correlation was found between P53 protein expression and tumour histologic type and site, and age and sex of patients. However, P53 protein expression in primary and metastatic tumours was found statistically significantly correlated.     

Expression of the p53 protein in oral squamous cell carcinomas associated with Epstein-Barr virus

The behaviour of the p53 protein has been investigated in some human carcinomas associated with Epstein-Barr virus (EBV) but not in EBV-positive oral squamous cell carcinomas (OSCC). The present study aimed to compare the p53 protein expression in EBV-positive OSCC with that in EBV-negative OSCC. The cases had been gathered in a study previously published. An immunohistochemical technique with BP53-12 monoclonal antibody was applied on 74 of the 107 OSCC from the earlier work. The nuclear or cytoplasmic expression of the p53 protein was classified as, absent (0% of neoplastic cells positive), mild (<25% positive), moderate (25-30% positive), or extensive (>50% positive). The p53 protein was expressed by 60.8% of the OSCC. Out of the fourteen EBV-positive OSCC, 57.1% (8 cases) expressed p53, always in the nucleus and never in the cytoplasm. Of the 60 EBV-negative OSCC, 61.6% (37 cases) expressed the p53 protein. Of 37 cases 33 (89.1%) showed nuclear expression of p53 and nineteen cases (51.3%) revealed cytoplasmic expression. There was a statistically significant inverse correlation between cytoplasmic expression of the p53 protein and the presence of EBV DNA (p <0.01). Thus, the EBV-positive tumours less frequently expressed p53 in the cytoplasm. No evidence of an accumulation of the p53 protein in OSCC associated with EBV was recorded.     

p53, MDM2, bcl-2 staining in follicular neoplasms of the thyroid gland

Sixty-two follicular adenomas of the thyroid were investigated by immunohistochemistry for the expression of p53, MDM2 and bcl-2 proteins. The wild type of 393 aminoacid nuclear p53 phosphoprotein is the product of a gene located on the short arm of chromosome 17. The p53 protein controls the growth of transformed cells in a culture and thus termed a suppressor gene product. Mouse double minute 2 (MDM2) gene product has been described to occur in malignant epithelial tissue, the protein product of this gene binds to and presumably inactivates the growth suppressive effect of wild type p53 protein. Bcl-2 is an oncogene whose product inhibits apoptosis in many cells types. Some scattered nuclei in two adenomas (3.2%) stained positively for p53. The adenomas with positive staining for p53 were subserially sectioned, but no signs of invasion were found, both patients are alive and well. In 12 adenomas (19%) there was positive reaction for MDM2 protein, whereas none of them where p53 positive. All cases were strongly positive for bcl-2 staining. We conclude that p53 protein expression is not confined to follicular adenomas, while MDM2 and bcl-2 genes products are.     

Fluorocytometric study of proliferation antigens, nuclear proteins and ploidy in acute leukosis]

P53 protein, Ki67 proliferative associated antigen and DNA content have been studied by flow cytometry in the blood blastic cells from 41 patients with acute leukemia. The results were compared with the F.A.B. classification. Cells were permeabilised and fixed by PLP solution before using the FITC conjugated Ki67 MoAb and the p53 MoAb (clone 1801). Propidium iodide and RNAase has been used in order to determine ploidy. Ki67 and p53 protein were found to be expressed at higher level in leukemia cells than in normal bone marrow cells; however there was no correlation between Ki67 and p53 expression and F.A.B. subtype. In acute leukemia patients the range of positivity of Ki67 was 1.1-52.1% while it ranged from 1.8% to 80.1% for the p53 protein. On the basis of these findings we conclude that the flow cytometry evaluation of Ki67 and p53 represents a useful tool for the study of the biologic characteristics of the leukemic cells in patients with acute leukemia.     

Detection of p53 protein and Ki-67 proliferation antigen in human papillomavirus (HPV)-positive and HPV-negative cervical lesions by immunohistochemical double-staining

In HPV-associated genital lesions, low or absent expression of p53 has been attributed to the rapid degradation of p53 through its binding with HPV E6 protein. In this study, we examined p53 protein expression with two antibodies (CM1 polyclonal and PAb 1801 monoclonal antibodies), and Ki-67 proliferation antigen (monoclonal antibody) using an immunohistochemical (IHC) double-staining technique in 77 HPV-positive cervical lesions (HPV6, HPV11, HPV16, HPV18, HPV31, and HPV33) and in 15 HPV-negative cases. p53 protein expression was detected in 36/92 (39.1%) of the specimens. of the p53-positive cases, 80.6% (29/36) were HPV-positive samples, including 10/23 (43.5%) of HPV16- and 3/10 (30%) of HPV18-positive biopsies. In 52.8% of the p53-positive samples, the expression was found in less than 5% of the basal cells which were also positive for Ki-67.
Ki-67 proliferation marker was found in 91/92 specimens, most intensely in those infected by HPV16. p53 was more abundant in progressive or persistent lesions, but no differences were found between HPV-positive and HPV-negative samples. the positive IHC double-staining of both p53 and Ki-67 proliferation antigen in the same basal (and parabasal) cells indicates that these two normal cell-cycle proteins are being expressed while the cells are entering from the G₁ to the S phase of the cell cycle. Since the latter property is only attributed to the wild-type p53 (but not to mutated p53), the p53 protein detected in HPV lesions by IHC is likely to be the wild-type p53 rather than mutated p53, and the result was also confirmed by using p53 mutant specific antibody PAb 240. Accordingly, the concept of HPV inactivating the wild-type p53 protein should be re-examined, and other mechanisms for HPV-mediated carcinogenesis should be considered.     

Quantitative immunohistochemical detection of the molecular expression patterns in proliferative inflammatory atrophy

The proliferative inflammatory atrophy (PIA) is considered as a possible precursor of prostate intraepithelial neoplasia (PIN) or prostate cancer (PCa). In this study we assessed quantitatively the expression of AMACR, p63, COX-2, GST and iNOS in serial paraffin-embedded tissue sections obtained after radical prostatectomy of PCa patients (n = 30). The applicability of these markers to distinguish PIA, PIN and PCa was evaluated. We also compared the immunohistochemical expression profiles of AMACR, COX-2 and GST in the luminal and basal cells in lesions of PIN arisen in PIA or PIA alone. Two different patterns of COX-2 expression according to the p63 status of the basal cells were found. This observation gives us grounds to hypothesize that the diverse COX-2 patterns resulted from an initial basal cell damage which subsequently propagated to its luminal secretory cells progeny.     

Comparative study of p53 expression in human carcinoma cell lines A549 and MCF7 under anticancer drug treatment

The effect of anticancer drugs on the expression of p53 protein in tumor cells was studied using the Western Blot analysis. Human lung carcinoma cell line A549 and human breast carcinoma cell line MCF7 sensitive (WT) and resistant (DOX/R) to doxorubicin were used. An increase in p53 protein expression was found in A549 and MCF7 (WT) cells treated with cisplatin, methotrexate, and doxorubicin, whereas the level of p53 was not statistically significantly changed in the MCF7 DOX/R cells. In the untreated MCF7 DOX/R cells the level of p53 protein was markedly higher than in the untreated WT MCF7 cells. A potential role of p53 protein in the development of doxorubicin-resistance in carcinoma cells is discussed.     

Immunohistochemical expression of retinoblastoma gene product (Rb), p53 protein, MDM2, c-erbB-2, HLA-DR and proliferation indices in human urinary bladder carcinoma

Archival biopsy specimens from transitional cell bladder cancers (n=88) were analysed immunohistochemically for the expression of the retinoblastoma (Rb) gene protein, p53, mdm2, c-erbB-2, HLA-DR antigen and proliferation indices. An altered nuclear expression of Rb, p53 and mdm2 was observed in 55.2%, 33.3% and 18.2% of tumors respectively. Cytoplasmic membrane immunoreactivity (>25% tumor cells) for c-erbB-2 was detected in 14.1% of tumors and aberrant HLA-DR antigen cytoplasmic staining (>5% of tumor cells) in 22.2% of the cases. P53 overexpression was associated with higher tumor grade and stage. Aberrant HLA-DR antigen expression and PCNA were also correlated with the grade of differentiation and tumor stage. MIB1 was statistically correlated with stage. pRb scores and HLA-DR antigen expression were correlated with proliferation activity as determined by PCNA and MIB1 immunostaining. p53 protein was also strongly correlated with the proliferation index PCNA. A strong correlation between PCNA and MIB1 (p<0.0001) was also found. In addition a statistically positive correlation between p53 and HLA-DR antigen expression was observed. Our data show that, although pRb and p53 protein expressions are not associated between them, they may contribute to the growth fraction of the bladder cancer. In addition, p53 and HLA-DR antigen expression could be indicators of aggressive behavior of bladder cancer.     

Insulin-like growth factor II (IGF-II) immunohistochemistry in breast cancer: relationship with the most important morphological and biochemical prognostic parameters

Recent in situ hybridization experiments have shown a high content of IGF-II mRNA in breast cancer stroma. The aim of this study was to examine the relationship between IGF-II protein expression and several prognostic parameters in 75 infiltrating ductal carcinomas (IDC) of the breast. Tissue sections were evaluated for proliferative activity, IGF-II protein, ER, PgR, p53, and p21 expression using immunohistochemical procedures. The degree of stromal proliferation was assessed. Menopausal status, axillary lymph node involvement and nuclear grade were known. Thirty-five patients (44.3%) were premenopausal and 47 (62.6%) had lymph node metastases. Marked stromal proliferation was found in 34 (45.3%) specimens and high nuclear grade in 20 (26.5%). Eighteen tumors (24%) showed no IGF-II immunostaining. In the positive cases, IGF-II was detected both in the tumor stroma and in the cytoplasm of epithelial cancer cells: a high IGF-II content was found in 12 specimens (16.0%), a low content in 14 (18.7%) and a moderate content in 31 (41.3%). Twenty-four tumors (32.0%) showed high proliferative activity. Both ER and PgR were expressed in the nucleus of cancer cells: 49 tumors (65.3%) were ER positive (ER+) and 34 (45.3%) PgR positive (PgR+). p21 protein was detected in 37 tumors (49.6%) and p53 in 12 (16%). IGF-II protein was not correlated with menopausal status, lymph node metastases, nuclear grade, proliferative activity, ER or p53. In contrast, IGF-II correlated strongly with stromal proliferation (p=0.008), PgR (p=0.03) and p21 (p=0.01). This study demonstrates that in IDC of the breast IGF-II protein is expressed in the epithelium and stroma of the majority of tumors and is correlated with stromal amount, PgR and p21 expression. These preliminary results indicate that IGF-II expression in breast cancer is connected with two important regulators of breast cancer growth and differentiation.     

Cytoplasmic localization of BAG-1 in leukoplakia and carcinoma of the tongue: correlation with p53 and c-erbB2 in carcinoma

BACKGROUND: The present study evaluated the clinical significance of BAG-1, an antiapoptotic protein, in leukoplakia and carcinoma of the tongue. METHODS: BAG-1 expression was evaluated by immunohistochemistry in paraffin-embedded tissues of leukoplakia (n=25) and carcinoma of the tongue (n=61). RESULTS: Cytoplasmic expression was predominantly seen in 80% and 70% of patients with leukoplakia and carcinoma, respectively. BAG-1 expression was found to be significantly lower in tobacco users than in non-tobacco users. BAG-1 expression in tobacco-using leukoplakia and carcinoma patients was compared by grouping the carcinoma patients according to lymph node status and disease stage. Carcinoma patients with tumor-positive lymph nodes had significantly lower BAG-1 expression than patients with negative lymph nodes and leukoplakia. Further, a trend towards an inverse correlation was observed with p53 and c-erbB2. In univariate and multivariate survival analysis, patient subgroups with 2+ or 3+ marker positivity (BAG-1 negativity, p53 and c-erbB2 positivity) had a reduced overall survival compared with patient subgroups with 1+ marker positivity or negativity. CONCLUSION: BAG-1 negativity in association with p53 and c-erbB2 positivity identified a subgroup of tongue cancer patients with an aggressive phenotype. Hence, an antiapoptotic protein, BAG-1, was found to be down-regulated in chewing-tobacco-mediated tongue carcinogenesis.     

p53突变蛋白在胃癌组织中的表达及免疫电镜观察

作者应用抗ｐ５３单克隆抗体Ｐａｂ１８０１（Ａｂ２美国癌基因公司产品）对３８例手术切除的胃癌组织及癌旁胃粘膜的冰冻切片标本进行ｐ５３突变蛋白表达的检测,并进一步用胶体全免疫电镜技术对ｐ５３突变蛋白的分布特征进行观察。结果：３８例胃癌组织中,２４例有ｐ５３突变蛋白高表达,阳性率６３．２％。在对应的癌旁胃粘膜中１０例为ｐ５３的弱表达,正常组织无表达。伴有淋巴结转移的２３例胃癌标本中,１８例ｐ５３高表达（７８．３％）。免疫电镜结果表现,ｐ５３蛋白主要分布于核内染色质中,胞浆中有散在的阳性区,但以核膜周边为主,紧靠核膜。本研究结果提承胃癌的发生及其肿瘤的生物学行为与抑癌基因ｐ５３的突变密切相关,ｐ５３突变蛋白可能是通过对ＤＮＡ复制的影响而参与肿瘤的形成。     

Basal cell subpopulation as putative human prostate carcinoma stem cells

The present study examines the expression of p63, glutathione S-transferase-pi (GSTP1) and alpha-methylacyl-CoAracemase (AMACR) in serial slices in proliferative inflammatory atrophy (PIA) in order to implicate that some of the basal cells are probably the putative human prostate carcinoma stem cells (PHPCSC). Archived tissue sections obtained after radical prostatectomy from cases (n=30) comprising of PIA were tested using immunohistochemistry with antibodies against AMACR (Dako), p63 and GSTP1 (Labvision) and visualized by biotin-streptavidin-peroxidase kit (DAKO LSAB 2 kit). Quantitative immunohistochemistry analysis (QIHC) of the studied antigen expression levels revealed that there are two populations of p63 basal cells. Type I basal cells had high AMACR, low GSTP1 and p63 expression. Type II basal cells had low AMACR, high GSTP1 and p63 expression. Therefore, we propose that the putative human prostate carcinoma stem cells probably reside within the population of type I basal cells.     

Expression of a transformation-related protein (p53) in the malignant stage of Friend virus-induced diseases.

Stage 1 (pre-malignant) and stage 2 (malignant) cells derived from mice infected with Friend murine leukemia virus or polycythemia-inducing Friend virus complex were examined and compared for the expression of a transformation-related cellular protein, p53. Stage 2 cells were found to express high levels of p53, whereas stage 1 cells did not express detectable levels of this protein. These results indicate that p53 may be a marker for transformed cells present in the second stage of diseases induced by Friend murine leukemia virus or polycythemia-inducing Friend virus complex.     

bcl-2癌基因蛋白在甲状腺癌中的表达及其意义

利用免疫组织化学技术,对６４例甲状腺癌进行了ｂｃｌ－２蛋白表达的检测,同时进行ｐ５３蛋白的对照检测。结果显示,甲状腺癌中ｂｃｌ－２蛋白阳性表达率为８１．３％（５２／６４）,但未分化癌无阳性表达。ｐ５３蛋白在甲状腺癌的阳性表达率为２０．３％（１３／６４）,而未分化癌全部为阳性表达。两种抗体在甲状腺癌的阳性表达率有显著性差异（Ｐ＜０．０１）。结果提示ｂｃｌ－２蛋白在甲状腺癌的表达与肿瘤细胞的分化程度有关,并与ｐ５３蛋白呈反比关系,ｂｃｌ－２与ｐ５３蛋白表达的不同分布可作为判断甲状腺癌预后的一个重要参考指标