Bcl-2 Protein Immunoreactivity Research Articles

The Role of Strain Variation in BAX and BCL-2 Expression in Murine Bleomycin-Induced Pulmonary Fibrosis

This study hypothesized that the expression of apoptosis-regulatory genes, such as BCL-2 and BAX may be affected by genetic variation in bleomycin-induced pulmonary fibrosis in C57BL/6 and NMRI mice. Pulmonary fibrosis induced by single intratracheal dose of bleomycin (3 U kg(-1)). After 2 weeks, lung samples were analyzed for collagen deposition, pathological changes and expression of BCL-2 and BAX. The fibrotic lung changes were similar in both strains. The immunohistochemical assay using a biotin-streptavidin technique showed no significant difference in immunoreactivity for BCL-2 protein between the controls and bleomycin-treated C57BL/6 mice. However, in NMRI mice, the expression of BCL-2 was significantly (p<0.05) upregulated in myofibroblasts and neutrophils. The expression of BAX protein was significantly (p<0.05) upregulated in alveolar epithelial cells of both strains and downregulated in myofibroblasts and lymphocytes of the lung tissues of C57BL/6 mice and also in lymphocytes of NMRI mice at 2 weeks after bleomycin instillation. These results confirm the role of BCL-2 and BAX proteins in the pathogenesis of pulmonary fibrosis and suggest that the expression of apoptotic regulatory genes may be specific in different cell types in various strains.

Expression of steroid hormone receptors, their regulated proteins, and bcl-2 protein in myofibroblastoma of the breast.

To investigate the possible role of steroid hormones in the pathogenesis of myofibroblastoma (MFB) of the breast, we analysed the immunohistochemical expression of oestrogen, progesterone, androgen receptors, their regulated proteins and bcl-2 protein in a series of this rare tumour. Paraffin-embedded sections from seven cases of MFB of the breast (five male; two female) were immunohistochemically tested for the expression of oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), oestrogen-regulated pS2 protein, androgen-regulated prostate-specific antigen (PSA) and bcl-2 protein. Rare cases of benign spindle cell tumours or tumour-like lesions of the breast (primitive fibromatosis, inflammatory pseudotumour, muscular hamartoma) which enter into the differential diagnosis with MFB, were also investigated and compared with MFB. All cases of MFB showed a diffuse (70-90% of neoplastic cells) and strong nuclear labelling with ER and PR, whereas AR was expressed only in three cases (two men and one woman) in about 60-70% of cells. Conversely, no immunostaining was detected for the pS2 protein and PSA. bcl-2 protein immunoreactivity was found in all cases of MFB, although with a variable degree of expression. No expression for steroid hormone receptors, their regulated-proteins and bcl-2 protein was observed in the rare benign spindle cell lesions of the breast included in this study. The in-situ detection of ER, PR and AR suggests that steroid hormones and their receptors are implicated in the pathogenesis of breast MFB. The consistent demonstration of bcl-2 protein, associated with a positive ER/PR status, provides evidence that bcl-2 may be an oestrogen-regulated protein also in MFB and that probably plays a role in the tumorigenesis. Finally, we postulate that the ER/PR and bcl-2 positive immunoprofile of MFB of the breast, in contrast to the negative profile of other rare primitive benign spindle cell lesions of the breast herein studied, might be exploited as an ancillary diagnostic aid in differential diagnosis of doubtful cases.

Immunohistochemical study of bcl-2 protein, Ki-67 antigen and p53 protein in epithelium of glandular odontogenic cysts and dentigerous cysts.

The aim of the present study was the evaluation of the immunohistochemical expression of the apoptosis-inhibiting protein bcl-2, the cell-cycle-related antigen Ki-67 and the p53 protein, which is involved both in cell cycle and apoptosis regulation, in the lining epithelium of glandular odontogenic cysts of the jaws. Formalin-fixed and paraffin-embedded tissue sections of three glandular odontogenic cysts and six dentigerous cysts were immunostained with a standard avidin-biotin peroxidase procedure, after microwave antigen retrieval. The glandular odontogenic cysts showed immunoreactivity for bcl-2 protein in the basal and suprabasal layers, while staining in dentigerous cysts was basal or focal. Most mucous cells and superficial cuboidal cells were negative. The percentage of Ki-67- or p53-positive cells was lower in glandular odontogenic cysts compared with dentigerous cysts. The findings suggest that the biological behavior of glandular odontogenic cysts may be associated with deregulation of cell death in the lining epithelium, while cell proliferation and p53 status do not seem to play a significant role.

Bcl-2 protein expression and gut neurohormonal polypeptide/amine production in colorectal carcinomas and tumor-neighboring mucosa, which closely correlate to the occurrence of tumor.

To clarify whether advanced colorectal carcinomas and tumor-neighboring mucosa simultaneously produce both Bcl-2 protein and gut neurohormonal polypeptides and/or amines, and the interrelationship of these phenomenon, we studied retrospective analysis of Bcl-2 protein production and neuroendocrine characteristics in 52 cases of advanced colorectal carcinoma and surrounding mucosa. All of the tumor-neighboring mucosa presented hyperplasia. The rates of enhanced immunoreactivity of the tumor-neighboring mucosa and of positive immunoreactivity of the carcinomas against human Bcl-2 protein and against human vasoactive intestinal polypeptide, pancreatic polypeptide and somatostatin were 78.8% and 94.2%, 82.7% and 59.6%, 78.8% and 67.3%, and 88.5% and 84.6% respectively. Double immunostaining for Bcl-2 protein and each peptide hormone revealed simultaneous expression. In contrast, that of tumor-neighboring mucosa and carcinomas to serotonin and chromogranin-A and to argyrophilia were 11.5% and 1.9%, 32.7% and 17.3%, and 26.9% and 21.2%, respectively. We concluded that tumor-neighboring crypt cells displayed not only hyperplasia but also neuroendocrine characteristics and that enhanced Bcl-2 protein immunoreactivity correlated with tumor occurrence in the wall of the colorectum. The production of Bcl-2 protein by tumor cells and tumor-neighboring crypt cells indicates that the bcl-2 protooncogene may act not only as an inhibitor of apoptosis but also as an inducer of neuroendocrine differentiation from the latent characteristics of the endodermal stem cell.

Pulmonary paraganglioid carcinoids and bcl-2 oncoprotein expression

Bcl-2 protein immunoreactivity was examined in 10 pulmonary carcinoid tumors with abundant S-100 protein-positive sustentacular cells (SCs) diagnosed as paraganglioid carcinoids. Its positivity in the mentioned tumors was compared with that of neoplasms formed of neuroendocrine cells only (30 pulmonary carcinoids), and with another group of 30 lesions consisting of neuroendocrine and sustentacular elements, i.e., paragangliomas (11 paragangliomas of the glomus caroticum and 9 jugulotympanic paragangliomas [JPTGs]), pheochromocytomas (5 cases), and a rare form of pulmonary tumorlets (PTUs) with a high frequency of SCs (5 cases). Bcl-2 protein was found in all 70 examined cases, and its expression showed no difference between the examined groups. On the basis of these results, bcl-2 protein expression was not found to be an indicator for either survival or useful for the differential diagnosis of pulmonary carcinoid tumors.

Bcl-2 protein expression in breast cancer and its relationship to prognosis

The expression of bcl-2 protein was studied in invasive breast cancer by immunohistochemistry. Fourty-six (56.8%) bcl-2 protein-positive tumors were found in 81 breast cancers. There was no significant correlation between the bcl-2 protein immunoreactivity and histologic type, primary tumor status, or lymph node metastasis. However, a strong positive relationship was demonstrated between bcl-2 immunoreactivity and estrogen receptor status. The 5-year survival rate and disease-free survival rates were 73.7% and 71.1% of patients with bcl-2-positive tumors, and 62.5% and 58.0% of those with bcl-2-negative tumors; these differences between the two groups of patients wete significant (p<0.05). In multivariate analysis using Cox regression model, bcl-2 immunoreactivity emerged as an independent prognostic indicator in breast cancer patients.

Merkel cells and Merkel cell carcinoma express the BCL-2 proto-oncogene.

The bel-2 proto-oncogene, which is involved in the regulation of apoptosis, is expressed in a wide variety of fetal and adult tissues. We and others have demonstrated recently that in the human skin melanocytes, nevus cells and melanoma cells express bcl-2 constitutively. In the present study, we have analysed the expression of bcl-2 in Merkel cells and in Merkel cell carcinomas. In 2 colour immunofluorescence staining, normal human Merkel cells as identified by the expression of cytokeratins 8, 18 and 20, were also anti-bcl-2 positive. Staining of paraffin sections of Merkel cell carcinomas with an anti-bcl-2 monoclonal antibody revealed strong bcl-2 protein immunoreactivity in all 5 tumors tested. Serial sections of Merkel cell carcinomas stained with the monoclonal antibodies CK 20, CAM 5.2, anti-neuron-specific enolase and anti-bcl-2 showed that the anti-bcl-2 reactive cells were indeed tumor cells. Our data demonstrate for the first time, that normal human Merkel cells and Merkel cel carcinomas express bcl-2 constitutively. Considering the biological function of the bcl-2 proto-oncogene, i.e., its anti-apoptotic effect, it is conceivable that in the near future, modulations of the expression of this protein may offer a new strategy in the therapy of bcl-2 expressing tumors such as Merkel cell carcinoma.

Merkel cells and Merkel cell carcinoma express the BCL-2 proto-oncogene.

The bcl-2 proto-oncogene, which is involved in the regulation of apoptosis, is expressed in a wide variety of fetal and adult tissues. We and others have demonstrated recently that in the human skin melanocytes, nervus cells and melanoma cells express bcl-2 constitutively. In the present study, we have analysed the expression of bcl-2 in Merkel cells and in Merkel cell carcinomas. In 2 colour immunofluorescence staining, normal human Merkel cells as identified by the expression of cytokeratins 8, 18 and 20, were also anti-bcl-2 positive. Staining of paraffin sections of Merkel cell carcinomas with an anti-bcl-2 monoclonal antibody revealed strong bcl-2 protein immunoreactivity in all 5 tumors tested. Serial sections of Merkel cell carcinomas stained with the monoclonal antibodies CK 20, CAM 5.2, anti-neuron-specific enolase and anti-bcl-2 showed that the anti-bcl-2 reactive cells were indeed tumor cells. Our data demonstrate for the first time, that normal human Merkel cells and Merkel cell carcinomas express bcl-2 constitutively. Considering the biological function of the bcl-2 proto-oncogene, i.e., its anti-apoptotic effect, it is conceivable that in the near future, modulations of the expression of this protein may offer a new strategy in the therapy of bcl-2 expressing tumors such as Merkel cell carcinoma.

Expression of bcl-2 protein in stage T1NOMO non-small cell lung carcinoma

The bcl-2 gene product ( bcl-2 protein, BCLP) prevents apoptotic cell death. Via a 14;18 chromosomal translocation, BCLP is overexpressed in most follicular lymphomas as well as some other non-Hodgkin's lymphomas, and it has also been documented in other nonlymphomatous malignancies. To address the possible prognostic value of this marker in predefined subsets of non—small cell lung carcinoma (NSCLC), the authors studied 126 T1NOMO cases seen between the years 1986 to 1991 at our institution. Patients were treated by lobectomy (105 cases) or wedge excision (21 cases) with negative margins; neuroendocrine carcinomas of all grades were specifically excluded. The mean follow-up period was 39 months. Immunostaining for BCLP was done using a monoclonal antibody (clone no. 124; DAKO, Carpinteria, CA), and the avidin-biotin-peroxidase complex (ABC) technique. The study cases included 73 adenocarcinomas (ACs) as well as 40 squamous cell (SCC), five adenosquamous (ASC), and eight large cell/poorly differentiated (LCC) carcinomas. As assessed with the Kaplan-Meier method, overall survival was 64% at 5 years (66% AC vs 59% SC). BCLP was detected in 47 of 126 cases (37%) including 32 AC (44%), 10 SCC (25%), two ASC (40%), and three LCC (38%). No significant difference in 5-year survival was noted in a comparison of all cases with BCLP expression (63%) and those without (59%). There was, however, a significant difference in the survival of grade 1 BCLP(+) cases, when compared with grade 2 or 3 BCLP(+) cases ( P = .01). A nonstatistically significant trend toward increased survival was observed in BCLP(+) SCC cases (66% 5-year survival in BCLP[+] vs 45% in BCLP[−] [ P = .11]). Proportional hazards analysis failed to disclose significant independent risk factors. These data suggest that bcl-2 protein immunoreactivity has limited prognostic value in the pathological evaluation of NSCLC.

Immunoreactivity for Bcl-2 protein within neurons in the Alzheimer's disease brain increases with disease severity

Bcl-2 protein has been suggested to be one of the proteins preventing apoptosis in a variety of cell types. Recently, apoptosis has been suggested to have an important role in the pathogenesis of Alzheimer's disease (AD). We have utilized Bcl-2 immunohistochemical methods to examine Bcl-2 in the hippocampus and entorhinal cortex of AD patients ranging in clinical and neuropathological severity from mild to severe and compared these results to those obtained from age-matched controls. Immunoreactivity for Bcl-2 was predominantly found within neurons. Bcl-2 immunostaining within AD tissue was increased relative to controls in most neurons of the entorhinal cortex, subiculum, CA1, CA2, CA3, hilus and dentate gyrus. Relative Bcl-2 staining increased in parallel with increasing disease severity. However, neurons exhibiting immunoreactivity for markers of neurofibrillary tangle formation (AT8 and PHF-1) showed reduced Bcl-2 staining, suggesting that Bcl-2 may be down regulated in these degenerating neurons. Bcl-2 immunoreactivity within astrocytes and the vasculature was also increased in AD. These results suggest that Bcl-2 protein may have a role in compensation responses to AD pathology, perhaps affording to the remaining neurons a margin of protection from apoptosis.

Immunoreactivity for bcl-2 protein in cutaneous lymphomas in lymphoid hyperplasias : Triscott JA, Ritter JH, Swanson BE, et al. J Cutan Pathol 1995;22:2–10

Immunoreactivity for bcl-2 protein in cutaneous lymphomas in lymphoid hyperplasias : Triscott JA, Ritter JH, Swanson BE, et al. J Cutan Pathol 1995;22:2–10

Immunoreactivity for bcl-2 protein in malignant mesothelioma and non-neoplastic mesothelium.

Immunohistochemical study of bcl-2 protein immunoreactivity in human non-neoplastic mesothelium (44 cases) and in malignant mesothelioma (62 cases) using a murine monoclonal antibody (clone 124) showed cytoplasmic immunoreactivity for bcl-2 protein in five cases of malignant mesothelioma. Non-neoplastic mesothelium was not immunoreactive. Immunoreactivity for bcl-2 protein does not add useful prognostic information in malignant mesothelioma since survival times of bcl-2 positive and bcl-2 negative cases did not differ. Nevertheless, the detection of bcl-2 protein in malignant mesothelioma might be useful for the differentiation from reactive mesothelium.

Immunoreactivity for bcl-2 protein in malignant mesothelioma and non-neoplastic mesothelium

Immunoreactivity for bcl-2 protein in malignant mesothelioma and non-neoplastic mesothelium