Biomedical subjects

N J Agnantis

Publications and source records attributed to N J Agnantis.

119 records · Page 7Linked to original sources

PubMedDate not supplied

Immunohistochemical detection of ras P21 oncoprotein in human skin lesions.

This study was undertaken to investigate the role of the human ras family gene product [P21] in various benign, precancerous and malignant skin lesions. A streptavidin-biotin peroxidase method was performed using the monoclonal antibody (Mab)Y13259 in paraffin tissue sections of a total of 69 skin lesions (5 benign hyperplasias, 12 seborrheic keratoses, 9 solar keratoses, 20 basal cell carcinomas and 23 squamous cell carcinomas). The adjacent normal skin was also studied in all cases. The expression of ras P21 was evaluated and graded in relation to the intensity of cytoplasmic immunostaining and the percentage proportion of positive epidermal cells. The following findings were noted in this study: 1) The positivity of ras P21 increased towards the keratin layer, according to cell maturation, in all normal, hyperplastic and "borderline" lesions, and to a lower degree in the seborrheic ones. 2) Comparing B.C.C. and S.C.C., higher expression was demonstrated in the latter, probably due to the high percentage of the well differentiated component.

Biopsy↗

PubMedDate not supplied

Immunohistochemical detection of ras p21 oncoprotein in breast cancer imprints.

We examined the expression of ras p21 oncoprotein using monoclonal antibody Y13 259 and applied the streptavidin-biotin method. A total of 79 imprints of breast lesions were taken during frozen section. Our purpose was evaluation of the staining intensity, at the cellular level, without the technical disadvantages of formalin-fixed, paraffin-embedded tissues. Of the 79 imprints examined, 37 were carcinomas of ductal origin (not otherwise specified type), 8 were lobular and 3 mixed. Additionally, 20 imprints from adjacent normal tissue as well as 11 fibroadenomas (simple and hyperplastic) were assessed. Our results showed the following: (1) the positivity of all cancer cells ranged from + to + + +, (2) positivity did not show any significant difference among cancer types, (3) in increasing the tumor grade, staining intensity was increased, (4) whenever benign epithelial cells were present, their expression was low or mild, (5) only hyperplastic fibroadenomas showed weak positivity, and (6) almost all the inflammatory components were constantly negative.

Adenofibroma↗

PubMedDate not supplied

Prognostic significance of C-erbB-2 and hormone receptors' status in human benign and malignant breast lesions.

In order to investigate the prognostic significance of c-erbB-2, estrogen receptors (ER) and progesterone receptors (PgR), an immunohistochemical staining was performed on 330 tissue sections from paraffin blocks of 50 fibrocystic diseases and 40 ductal adenocarcinomas N.O.S. type, grade II (20 with lymph node metastases (L.N.M)). The positivity for c-erbB-2 was considered only in the cytoplasmic membrane, while for ER and PgR in the nucleus of epithelial cells. All markers showed a heterogenous pattern of staining. Our results imply that benign lesions were negative for c-erbB-2 and hormone receptors except for limited areas with papillary proliferations. Elevated expression of these markers was noted in the adenocarcinomas. No significant difference was observed between the percentage of all markers in primaries and L.N.M. lesions. Hormone receptors' status showed no significant correlation with c-erbB-2 expression. Our results suggest that c-erbB-2, ER and PgR, especially when combined with clinicopathological parameters, may show some prognostic usefulness in breast disease.

Breast Neoplasms↗

PubMedDate not supplied

The prognostic significance of epidermal growth factor receptor (EGFR), C-erbB-2, Ki-67 and PCNA expression in breast cancer.

The evaluation of the immunohistochemical expression of epidermal growth factor receptor (EGFR), c-erbB-2 oncoprotein, proliferating indices Ki-67, and PCNA were determined on 68 primary breast carcinomas. These markers were correlated with each other and with other clinicopathological variables such as: age, tumor size? histotype, tumor grade and steroid receptors' content as well as nodal status. The monoclonal antibodies anti-human Epidermal Growth Factor Receptor (EGFR1), anti-human Ki67 (DAKO) and N13259 (Oncogene Science) were applied to paraffin and frozen tissue sections. All markers showed an heterogeneous pattern of staining. There was almost equally high staining intensity at the membranus for EGFR and c-erbB-2 in about 32% of the cases. The EGFR and c-erbB-2 positive cases were much less common in infiltrating lobular (2,2/13) rather than in ductal adenocarcinomas (21,20/55). The low grade carcinomas showed low expression of EGFR and c-erbB-2 oncoprotehl comparing with high grade ductal adenocarcinomas. A high index of Ki-67 was correlated with EGFR and c-erbB-2 membrane positivity. There was an inverse relationship between the expression of c-erbB-2 and EGFR, when compared with oestrogen receptors' content. A significant correlation was also demonstrated between EGFR and c-erbB-2 immunoreactivity with lymph node status. Our results provide evidence that the synchronous immunohistochemical detection of EGFR, c-erbB-2 and Ki-67 may be of useful significance in breast cancer patients, especially when combined with other clinicopathological variables. Furthermore the expression of EGFR and c-erbB-2 oncoprotein may affect the cell proliferation and differentiation.

Biomarkers, Tumor↗

PubMedDate not supplied

Clonal analysis by PCR and RFLP in breast cancer and precancerous lesions. Preliminary data.

In order to investigate the clonality in various benign, precancerous and malignant breast lesions, we analyzed small DNA samples from paraffin sections of various breast lesions by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) of the X-chromosome-linked phosphoglycerokinase (PGK) gene. DNA from the lesion as well as from the adjacent normal tissue were analyzed in each case. Two restriction endonucleases. Hpa-II, a methylation sensitive restriction enzyme and Bst XI, a restriction endonuclease, which recognizes this polymorphic site on the PGK gene, were used. Of 19 cases, one case of in situ ductal Ca (DCIS), two cases of invasive ductal Ca and one case of multifocal ductal Ca were shown to be monoclonal. Two cases of intraductal papillomas were found to be polyclonal. One case of atypical ductal hyperplasia showed no conclusive findings. Additionally DNA was not yielded from 3 cases and other 7 cases were not informative, derived from females homozygotes. Further study of a larger number of cases is in progress.

Breast Neoplasms↗

PubMedDate not supplied

p53 DO-1 immunohistochemical overexpression in premalignant and malignant cervical lesions.

One hundred-fourteen cervical lesions, including paraffin sections from benign, premalignant and malignant cervical tissue specimens were examined immunohistochemically for overexpression of p53 protein, using the p53 DO-1 monoclonal antibody (MoAb). p53 overexpression was observed in 66% of premalignant cervical lesions and in 90% of invasive squamous cell carcinomas. The difference in p53 positive lesions of premalignant and malignant cervical lesions was statistically very significant (p < 0.001) and the difference between CIN1 and CIN2 and CIN3 statistically significant (p < 0.01). Our results indicate that p53 overexpression may be involved at an early stage in cervical carcinogenesis.

Antibodies, Monoclonal↗

PubMedDate not supplied

Expression of p53 protein in gastric cancer: an immunohistochemical study with correlation to proliferative activity.

Immunohistochemical detection of p53 was performed by using the monoclonal antibody D0-7 (IgG2b) in 52 gastric cancers. Positive staining was detected in 42% (22/ 52) of the cases. There was no significant correlation between p53 expression and parameters such as age, sex, location, histological type, size, tumor grade depth of invasion, product of mucus and lymph node metastases. The nuclear p53 immunoreaction was closely associated with necrosis (p < 0.05) and vessel invasion (p < 0.05). For the estimation of proliferative activity, proliferating cell nuclear antigen labelling index (PCNA-LI) and Ki-67-LI on paraffin and frozen sections were immunohistochemically measured. A significant positive correlation was found between PCNA-LI and p53 tissues' immunoreactivity. There was a significant correlation in the depth of tumour invasion (p < 0.05) and PCNA-LI, and a small correlation of with grade (p = 0.075) and vessel invasion (p = 0.078). No significant association could be established with any clinicopathological parameters and Ki-67-LI. These results suggest that the p53 gene may be play an important role in the expansion of gastric carcinoma and in the proliferative activity, as determined with PCNA-LI.

Adult↗

PubMedDate not supplied

Matrix metalloproteinase expression in human breast cancer: an immunohistochemical study including correlation with cathepsin D, type IV collagen, laminin, fibronectin, EGFR, c-erbB-2 oncoprotein, p53, steroid receptors status and proliferative indices.

Matrix metalloproteinases (MMPs) are a group of enzymes thought to be responsible for both normal connective tissue matrix remodelling and accelerated breakdown associated with tumour development. The current study aimed to investigate the immunohistochemical expression of matrix metalloproteinase 3 (MMP-3, stromelysin-1) in correlation with the expression of Basement Membrane (BM) antigen (type IV collagen, laminin), fibronectin, cathepsin D, p53, c-erbB-2, proliferative activity (Ki-67, PCNA), steroid receptor content as well as to the other conventional clinicopathological parameters in breast cancer. This study was performed on a series of frozen and paraffin sections from 84 breast cancer specimens by immunohistochemistry using the monoclonal antibody MMP-3 (Ab-1). Stromelysin-1 (ST1) was observed in about 10% of epithelial cells in the control groups (cases of fibrocystic and benign proliferative breast disease), while expression (> 10% of expression) was detected in 89.7% of tumours. The expression of ST1 in carcinoma cells was strongly associated with its presence in the stroma (p < 0.001). A significantly positive correlation was found between ST1 expression, and p53 tumour suppressor gene product (p = 0.004), and a relationship with c-erbB-2 protein and progesterone receptor status was also indicated. These findings suggest that ST1 expression in breast cancer tissue is irrespective of the expression of the extracellular matrix component, the proteolytic enzyme cathepsin D and the growth fraction of the tumour, and that it could be a potential new prognostic marker in breast cancer.

Breast Neoplasms↗

PubMedDate not supplied

Lymphocyte subsets in superficial bladder cancer: correlation with biological activity of the tumours.

BACKGROUND: The investigation of relationship of tumour biological activity and the degree of tissue infiltrating lymphocytes (T4, T8, T6) and macrophages in bladder cancer was the purpose of this study. MATERIALS AND METHODS: Tumour specimens and near and distant biopsies from 26 patients suffering from superficial bladder cancer and bladder biopsies from 6 controls were studied. Monoclonal antibodies against T helper/inducer, (CD4), T suppressor/cytotoxic (CD8), Langerhans cells (CD1a) and Monocytes/Histiocytes (LeuM5) were used for the detection of lymphocyte subpopulations. Ki67 growth fractions and recurrence rate per 100 patients-months were used for the definition of the biological activity of the tumours. RESULTS: The degree of tissue infiltrating lymphocytes differed significantly between controls and both groups. Larger (but not significantly different) numbers were noticed in the non recurrence compared to the recurrence group of patients. CONCLUSIONS: We conclude that the host's immune defence mechanism against malignant cells does not seem to produce significantly different numbers of tissue infiltrating lymphocytes in tumours of low and high aggressiveness. On the other hand the degree of lymphocyte infiltration in bladder cancer is not marked compared to controls of controls of matching age.

Aged↗

PubMedDate not supplied

Immunophenotype, ras oncogenes and p53 onco-suppressor gene in benzo(a)pyrene induced malignant soft tissue tumours in Wistar rats.

This study was designed to identify the immunophenotypic characteristics of malignant soft tissue tumours, induced experimentally with benzo(a)pyrene (BaP), and to evaluate the immunohistochemical expression of the ras oncogene family and p53 onco-suppressor gene in these tumours, in association with prognostic factors. Seventy-five male Wistar rats were subcutaneous injected, dorsally, with a single dose of 10.08 mgr BaP. A solid, well-circumscribed tumour was formed at the injection site, in 70 of the animals, 80-100 days after the carcinogen's administration. The tumour as well as selected main organs were excised and studied after the animals' death. All the specimens were fixed in formalin 10%, embedded in paraffin and stained with H + E. The immunohistochemical avidin-biotin method was performed in the tumour sections, using the following monoclonal or polyclonal antibodies: vimentin, desmin, muscle specific actin (MSA), a-smooth muscle actin (SMA), myoglobin, smooth muscle myosin, a-1-antitrypsin, a-1-antichymotrypsin, S-100 protein, epithelial membrane antigen (EMA), K-ras, H-ras, Pan-ras and p53. The induced tumours of the animals were almost well-circumscribed, with a partly storiform cut surface. Histologically, their appearance was more conventional with high grade leiomyosarcomas; about half of them showed highly anaplastic areas, resembling other pleomorphic undifferentiated sarcomas. Pulmonary metastatic foci were detected in 37 animals. Immunohistochemically, all the tumours displayed positive expression of vimentin, MSA and SMA. Desmin was positively expressed in 40 tumours, smooth muscle myosin in 57 tumours and EMA in 12 tumours. All the tumours were negative for myoglobin, a-1-antitrypsin, a-1-antichymotrypsin and S-100 protein. In addition, five tumours showed a positive reaction for K-ras p21, 37 for H-ras p21, 41 for Pan-ras p21 and 14 for p53 protein. The overexpression of the oncoproteins H-ras p21 and Pan-ras p21 in these tumours was significantly associated with a non-advanced tumour stage (absence of metastatic focus). In conclusion, the histological as well as the immunophenotypic features of the induced tumours are more conventional with leiomyosarcomas mostly of high grade; many of them are "dedifferentiated". The identification of both ras and p53 gene products in these tumours indicates that alterations of these genes are common but not specific events, implicated in the tumourigenesis, which may become prognostic markers for this subtype of soft tissue sarcomas.

Animals↗

PubMedDate not supplied

p53/MDM-2 immunohistochemical expression correlated with proliferative activity in different subtypes of human sarcomas: a ten-year follow-up study.

The aim of this study was the evaluation of p53/MDM-2 protein overexpression in different subtypes of human sarcomas, and their correlation with proliferative activity and patient outcome. We selected 40 cases of human sarcomas comprising 6 malignant fibrous histiocytomas (MFH), 1 fibrosarcoma, 1 dermatofibrosarcoma protuberans, 5 liposarcomas, 9 leiomyosarcomas, 1 rhabdomyosarcoma, 3 synovial sarcomas, 2 osteosarcomas, 1 chondrosarcoma, 4 Ewing's sarcomas, 2 Kaposi's sarcomas, 1 malignant haemangiopericytoma, 1 phylloides cystosarcoma, 1 neuroblastoma, 1 chordoma and 1 unclassified sarcoma. All the immunohistochemical markers, which had been used for the characterization of these sarcomas were re-examined. Additionally, the Streptavidin-Biotin peroxidase method was performed on paraffin sections using the monoclonal antibodies: anti-p53 antibody DO7, anti-MDM-2 antibody IF2 and anti-Ki-67 antibody MIB-1. According to our results, p53 protein nuclear expression was detected in 20% (8/40) of the tumours (1 fibrosarcoma, 2 liposarcomas, 1 leiomyosarcoma, 1 rhabdomyosarcoma, 2 Ewing's sarcomas and 1 unclassified sarcoma). MDM-2 nuclear staining was determined in 7.5% (3/40) of the cases (1 MFH and 2 liposarcomas). A high proliferative index was demonstrated in 27.5% (11/40) of the tumours (2 MFH, 4 leiomyosarcomas, 1 rhabdomyosarcoma, 1 osteosarcoma, 2 Ewing's sarcomas and 1 unclassified sarcoma). p53 overexpression was associated with high tumour grade (p < 0.05) and MIB-1 expression was correlated with reduced survival (p < 0.05), but p53 overexpression was not significantly associated with either MIB-1 score or with overall survival of the patients. In conclusion, from this limited and heterogeneous sample of cases, we suggest that the p53/MDM-2 pathway is involved in the tumourigenesis of several sarcoma subtypes, but it is unclear if the overexpression of these genes may become prognostic marker for patients affected with these highly aggressive tumours.

Adolescent↗