Immunohistochemical assessment of E-cadherin and beta-catenin in trichofolliculomas and trichoepitheliomas

Background: Trichofolliculomas and trichoepitheliomas are benign skin neoplasms originating from hair follicle cells. They result from defects in the signaling pathways that regulate hair follicle morphogenesis and regeneration. Thus they seem to be an excellent model of these processes. It is known that the E-cadherin/beta-catenin system of adhesion molecules plays a crucial role in the maintenance of tissue architecture. Aim: The aim of the present study was to investigate their involvement in benign hair follicle tumor development. Methods: Semiquantitative intensity of expression were examined in formalin-fixed and paraffin-embedded tissue sections of 53 trichoepitheliomas, 15 trichofolliculomas and 19 normal skin samples by indirect immunohistochemistry. Results: The intensity of E-cadherin/beta-catenin expression in tumor cells did not differ from controls. However, normal hair follicles cells exhibited membranous E-cadherin/beta-catenin expression, whereas both types of tumors, particularly trichoepitheliomas, showed E-cadherin/beta-catenin expression with a predominantly cytoplasmic localization. Conclusions:We suggest that this dystopic distribution of the E-cadherin/beta-catenin complex in hair follicle tumor cells may be a marker of cell-cell adhesion disruption which may contribute to the tumor formation.     

Immunohistochemical expression of Bcl-2, p53 and caspase-9 in hypothalamus magnocellular centers of nNOS knockout mice following water deprivation

Abstract

We studied the interactions between apoptosis regulator proteins (Bcl-2, p53 and caspase-9) and neuronal nitric oxide in vasopressinergic magnocellular centers of the hypothalamus using neuronal nitric oxide synthase (nNOS) gene knockout mice. nNOS gene deletion resulted in accumulation of Bcl-2, p53 and caspase-9 in the paraventricular (PVN) and supraoptic (SON) nuclei in controls. Dehydration increased the levels of all three apoptosis regulator proteins studied in nuclei of wild type mice. In the hypothalamus magnocellular centers of nNOS knockout mice, however, expression of Bcl-2, p53 and caspase-9 was unchanged after dehydration. The number of magnocellular neurons did not change in the SON and PVN of nNOS deficient mice compared to wild type, and after dehydration, cell death was not observed in either nucleus of wild type or knockout mice despite activation of apoptosis regulator protein expression. Thus, we demonstrated that gene disruption of nNOS prevents activation of Bcl-2, p53 and caspase-9 expression during water deprivation, and that nNOS deficiency did not affect survival of magnocellular neurons of the hypothalamus.     

Immunohistochemical investigation of Bcl-2 and p53 levels in rat hypothalamus after sleep deprivation

On Wistar rats in view of electrophysiological parameters after sleep deprivation (SD; awake by gentle handling method) and the subsequent postdeprivative sleep (PDS) immunohistochemical investigation of Bcl-2 and p53 peptides optical density levels in neurons of paraventricular (PVN), supraoptic (SON) and median (MnPN) hypothalamus nuclei was carried out. The Bcl-2 was increased in all nuclei both after SD and PDS. The level of p53 was increased in PVN and SON after SD and PDS, but in MnPN only on PDS. Any morphological attributes of apoptosis in the nuclei was not revealed. Obtained data testify an active role of p53 and Bcl-2 peptides in regulation of neuronal activity in hypothalamus at change of a cycle wakefulness-sleep.     

LPS-induced neutrophilic inflammation and Bcl-2 expression in metaplastic mucous cells

Our previous studies show that Bcl-2, a regulator of apoptosis, may be involved in the reduction of mucous cell metaplasia (MCM) during recovery from inflammatory responses. The present study was to determine whether neutrophilic inflammation mediates Bcl-2 expression in mucous cells. Rats were intratracheally instilled with 50-1000 microg of LPS. The number of neutrophils recovered by bronchoalveolar lavage (BAL) increased with the dose of LPS, and the percentage of Bcl-2-expressing cells increased with the numbers of neutrophils in the BAL. Depletion of neutrophils did not reduce MCM, but the percentage of Bcl-2-positive cells increased 1.8-fold in neutrophil-depleted compared with controls. Injection of rats with bezafibrate, an inducer of cytochrome P-450, doubled the number of neutrophils in the BAL, decreased MCM twofold compared with vehicle-injected controls, and reduced Bcl-2 expression. Bcl-2 mRNA levels decreased in a tracheal epithelial cell line treated with bezafibrate. These data demonstrate that Bcl-2 expression is independent of the number of neutrophils in the BAL and that bezafibrate may directly reduce Bcl-2 expression in epithelial cells.     

HCV核心蛋白、p53、Mdm2及Bcl-2在HCC中的表达意义

目的:探讨HCC组织中的核心蛋白、突变p53、Mdm2、Bcl-2的表达以及其相关性,探讨HCV核心蛋白是否有可能促进p53突变、Mdm2和Bel-2的表达.方法:收集手术切除HCC组织42例,采用免疫组织化学EnVision法检测HCC组织核心蛋白、突变p53、Mdm2、Bel-2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:C蛋白、p53、Mdm2和Bcl-2在HCC癌组织中的表达率分别为40.5%、47.6%、75.6%、83.3%;4组强度等级资料Kruskal.Wallis秩和检验H=19.01,差异性显著(p=0.000),Mann-Whimey U test:C蛋白和p53、Mdm2、Bcl-2蛋白问的P值分别0.43、0.009、0.00;C蛋白与突变p53、Bcl-2阳性强度两者间相关性检验P值分别为0.000、0.914,相关系数rs分别为0.67、0.08;突变p53与Mdm2、Bcl-2两者相关性检验P值为0.000、0.27,相关系数rp为0.72、0.32.结论:在HCV核心蛋白表达的HCC中核心蛋白可能促进野生型p53突变和表达;突变p53很可能促进Mdm2的表达;核心蛋白和突变p53都有可能促进Bcl-2蛋白的表达;HCV相关的HCC中这些蛋白的变化很可能促进肝细胞增殖或恶性生长.     

Bcl-2 expression in colorectal tumours. Correlation with p53, mdm-2, Rb proteins and proliferation indices

Immunostaining for bcl-2 protein was performed in 27 colorectal adenomas and 108 colorectal adenocarcinomas. The aim of the study was to determine bcl-2 expression in correlation with p53, mdm-2 and Rb expression, with proliferation indices (Ki-67-LI, PCNA-LI) as well as with conventional clinicopathological variables. A higher proportion of adenomas (30.8%) than carcinomas (16.7%) expressed bcl-2 and conversely, a lower proportion of adenomas (7.4%) than carcinomas expressed p53 (57.1%), the difference being statistically significant (p<0.0001). No correlation of bcl-2 expression with p53 expression (parallel or inverse) as well as with the other parameters studied was observed in any tumour. The bcl-2+/p53- subgroup of cancers showed a trend for correlation with negative lymph node status. Our data suggest, that bcl-2 expression may be involved in the early phase of colorectal carcinogenesis regardless of p53 status, while p53 function may be involved in a late stage of the adenoma-carcinoma sequence. P53 is apparently not involved in the regulation of apoptosis in the colorectal neoplasias or perhaps bcl-2 expression, as an early event in colorectal tumours, may occur before changes of p53 take place. Tumours with bcl-2+/p53- immunophenotype are frequently associated with negative lymph node status and seem to have a less aggressive behavior.     

Immunohistochemical study of cell proliferation, Bcl-2, p53, and caspase-3 expression on preneoplastic changes induced by cadmium and zinc chloride in the ventral rat prostate.

This work was directed to evaluate immunoexpression of markers for apoptosis, resistance to apoptosis, and cell proliferation, as well as estimates of nuclear size in ventral prostate of rats treated with cadmium chloride and cadmium+zinc chloride because a possible protective effect of zinc has been postulated. The following variables were studied: volume fraction (VF) of Bcl-2 immunostaining, percentage of cells immunoreactive to proliferating cell nuclear antigen (LIPCNA) and p53 (LIp53), numerical density of caspase-3 immunoreactive cells (NV caspase-3), and estimates of volume-weighted mean nuclear volume (upsilonV). The LIPCNA and VF of Bcl-2 were significantly increased in the treated animals. The dysplasias (independent of their origin) showed a significant increase of the LIp53, NV caspase-3, and upsilonV in comparison with normal acini from treated and control animals. It can be concluded that cell proliferation is enhanced in long-term cadmium-exposed rats, and exposure to zinc combined with cadmium had no effect on any of the variables studied when comparing with normal acini. The increase of nuclear upsilonV could indicate a more aggressive behavior for pretumoral lesions.     

Phenylbutyrate-induced apoptosis and differential expression of Bcl-2, Bax, p53 and Fas in human prostate cancer cell lines

OBJECTIVE: To assess the mechanisms of action of phenylbutyrate (PB), an investigational chemotherapeutic agent for prostate cancer (PCa), in apoptosis induction in PCa cell lines in vitro. STUDY DESIGN: We analyzed the differential expression of different apoptosis modulators, Bcl-2, Bax, p53 and Fas, for their potential role in PB-induced apoptosis using relative quantitative flow cytometry (FCM). Both androgen-dependent (LNCaP) and androgen-independent (C-4-2, PC-3-PF and DU145) human PCa cell lines were examined. RESULTS: PB induced apoptosis in PCa cell lines in a dose-dependent manner. Fifty percent apoptosis could be induced by 5-10 mM PB. Bcl-2 was down-regulated 30-75% and the Bax:Bcl-2 ratio elevated in apoptotic PCa cell lines regardless of their androgen dependency or p53 status. FCM revealed a heterogeneous stimulatory effect on the expression of Bax and Bcl-2 in PC3-PF cells at 0.5-2.5 mM PB. In a p53-positive cell line (DU145), p53 was repressed by 70% and Fas elevated sixfold with 10 mM PB. CONCLUSION: Our data show that PB-induced PCa apoptosis is associated with the relative repression of Bcl-2 and with up-regulation of Bax and Fas proteins and that this PB-induced apoptosis is independent of p53 and androgen-dependency status of PCa cell lines.     

Immunohistochemical localization and correlation of p53 and PCNA expression in breast carcinoma

The object of the present study is to detect the p53 tumour suppressor gene and proliferation cell nuclear antigen (PCNA) expression in breast carcinoma by immunohistochemistry and correlate them with the prognostic parameters. Total 35 cases of primary breast carcinoma were studied and classified histologically. Paraffin sections were stained by using monoclonal antibody D07 for p53 protein and PC-10 for PCNA. Out of 35 cases, 16 (45.7%) were p53 positive and 25 (71.4%) were PCNA positive. The mean PCNA labelling index (PCNA LI +/- SD) was 58.97 +/- 22.72 in tumors positive for both p53+ and PCNA+ while cases negative for p53- and positive for PCNA+ has higher PCNA LI +/- SD (59.24 +/- 18.97). The difference in the two groups was not significant. Most cases were positive for both p53+ and PCNA+ in the age group < 30 with higher mean PCNA LI +/- SD (62.20 +/- 27.13) than in the group > 30 (57.88 +/- 18.47). In the pre-menopausal group 57.1% cases were positive for p53+ with higher PCNA LI +/- SD (59.94 +/- 24.22). Maximum p53 and PCNA positivity was observed in grade III tumors (63.2% and 84.2%). The mean PCNA LI +/- SD was also highest in grade III carcinomas (66.83 +/- 13.97). No significant correlation was found between p53 and PCNA status with morphological type and tumour size except that logistic regression showed a positive correlation with tumour grade. Therefore the present study suggests that both p53 expression and PCNA are markers of poor differentiation in breast cancer.     

Immunohistochemical expression of p53 in animal tumors: a methodological study using four anti-human p53 antibodies

Mutations in the p53 tumor suppressor gene are the most common genetic alterations in human cancers. These mutations usually lead to strongly enhanced protein stabilization and allow detection by immunohistochemistry. Two monoclonal (DO-7 and PAb-240) and two polyclonal (Ab-7 and CM-1) antibodies were evaluated by standard immunoperoxidase method in domestic animal tumors, chiefly squamous cell carcinomas (SCC), and osteosarcomas as positive controls. Immunoreactivity was detected in SCC of cattle, sheep, horse and cat as well as in feline actinic keratosis, with PAb-240 and CM-1 antibodies. One polyclonal antibody (Ab-7) did not give positive result at all, whereas DO-7 monoclonal antibody did not react in dogs and cats. Immunodetection of p53 protein is thus possible in all domestic species tested, especially with CM-1 and PAb-240 antibodies, and p53 alterations seem to occur early in carcinogenesis of feline SCC as in comparable human lesions.     

Immunohistochemical analysis of pRb2/p130, VEGF, EZH2, p53, p16(INK4A), p27(KIP1), p21(WAF1), Ki-67 expression patterns in gastric cancer

Although the considerable progress against gastric cancer, it remains a complex lethal disease defined by peculiar histological and molecular features. The purpose of the present study was to investigate pRb2/p130, VEGF, EZH2, p53, p16(INK4A), p27(KIP1), p21(WAF1), Ki-67 expressions, and analyze their possible correlations with clinicopathological factors. The expression patterns were examined by immunohistochemistry in 47 patients, 27 evaluated of intestinal-type, and 20 of diffuse-type, with a mean follow up of 56 months and by Western blot in AGS, N87, KATO-III, and YCC-2, -3, -16 gastric cell lines. Overall, stomach cancer showed EZH2 correlated with high levels of p53, Ki-67, and cytoplasmic pRb2/p130 (P < 0.05, and P < 0.01, respectively). Increased expression of EZH2 was found in the intestinal-type and correlated with the risk of distant metastasis (P < 0.05 and P < 0.01, respectively), demonstrating that this protein may have a prognostic value in this type of cancer. Interestingly, a strong inverse correlation was observed between p27(KIP1) expression levels and the risk of advanced disease and metastasis (P < 0.05), and a positive correlation between the expression levels of p21(WAF1) and low-grade (G1) gastric tumors (P < 0.05), confirming the traditionally accepted role for these tumor-suppressor genes in gastric cancer. Finally, a direct correlation was found between the expression levels of nuclear pRb2/p130 and low-grade (G1) gastric tumors that was statistically significant (P < 0.05). Altogether, these data may help shed some additional light on the pathogenetic mechanisms related to the two main gastric cancer histotypes and their invasive potentials.     

Early and late apoptosis protein expression (Bcl-2, BAX and p53) in traumatic brachial plexus injury

Objectives:This research aims to analyze the expression of pro-apoptotic proteins (Bax, p53) and anti-apoptotic protein (Bcl-2) in the nerve roots of the brachial plexus following traumatic brachial plexus injury (TBPI) in the early and late stage.Methods:A total of 30 biopsy samples were taken from the proximal stump of the postganglionic nerve roots of the TBPI patients’ brachial plexus from January 2018 until September 2019. The samples were taken from patients within six months of trauma (early stage, group A) and more than six months following trauma (late stage, group B). Bcl-2, Bax, and p53 expressions in each group were measured and compared.Results:We found significant differences in the Bcl-2 (p=0.04), Bax (p<0.0001), p53 (p<0.0001) expressions between group A and B. The Bcl-2/Bax expression ratio in group A and B was 2.26 and 0.22, respectively. Meanwhile, the Bcl-2/p53 expression ratio in group A and B was 1.64 and 0.23, respectively.Conclusion:Apoptosis is inhibited by Bcl-2 activities in the early stage following trauma. In the late stage, a significant decrease of Bcl-2 coupled with a substantial increase of Bax and p53 indicates a continuation of the apoptotic process.     

p53、BCL-2、Caspase－3等凋亡相关蛋白在大鼠脑损伤中的表达及意义

目的：检测脑外伤大鼠中p53、bcl-2及caspase-3表达,并分析其与脑外伤之间的关系,为脑损伤患者预后提供部分参数依据。方法：建立脑外伤大鼠实验动物模型,用免疫组化方法检测p53、Bcl-2和Caspase-3的表达。结果：脑创伤后在创伤周围区的神经元会发生凋亡,凋亡的发生可能与p53、bcl-2、caspase-3等基因及蛋白的调节有关。结论：脑创伤后在创伤周围区的神经元会发生凋亡,凋亡的发生可能与p53、bcl-2、caspase-3等基因及蛋白的调节有关。     

p53、BCL-2、Caspase-3 等凋亡相关蛋白在大鼠脑损伤中的表达及意义

目的:检测脑外伤大鼠中p53、bcl-2及caspase-3表达,并分析其与脑外伤之间的关系,为脑损伤患者预后提供部分参数依据。方法:建立脑外伤大鼠实验动物模型,用免疫组化方法检测p53、Bcl-2和Caspase-3的表达。结果:脑创伤后在创伤周围区的神经元会发生凋亡,凋亡的发生可能与p53、bcl-2、caspase-3等基因及蛋白的调节有关。结论:脑创伤后在创伤周围区的神经元会发生凋亡,凋亡的发生可能与p53、bcl-2、caspase-3等基因及蛋白的调节有关。     

Immunohistochemical expression of p53 in breast carcinoma is associated with the intron 1 BglII polymorphism of the p53 gene

Breast carcinoma is a public health problem worldwide. It is known that both genetic and environmental factors are important for breast carcinogenesis and that structural and/or functional alterations at p53 gene are commonly observed in breast tumors. In addition, polymorphisms of several genes in either their coding or non-coding sequences have been found related to cancer risk and/or clinicopathological characteristics of tumors. In this study we have evaluated the intron 1 BglII polymorphism of the p53 gene with a PCR-based approach in 117 cases of breast cancer and 102 healthy women and its association with the immunohistochemical expression of p53 in the tumors. The results showed that the presence of the polymorphism (allele 2) is highly associated with the tumor expression of p53 (p<0.0001) and that there is a trend for increased frequency of allele 2 in cases than in controls (p=0.2376). These data suggest that the germ-line variation in the intron 1 of the p53 gene could produce functional or structural changes of the protein that is reflected by its abnormal expression.