The spectrum of 67-kD laminin receptor expression in breast carcinoma progression.
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in Journal of Pathology (The) (1997), 182(1), 36-44
Laminin is a glycoprotein of the basement membrane (BM), involved in a variety of normal and pathological cellular events including tumour invasion and metastasis. Cells bind laminin through different ... [more ▼]
Laminin is a glycoprotein of the basement membrane (BM), involved in a variety of normal and pathological cellular events including tumour invasion and metastasis. Cells bind laminin through different types of receptor. The 67-kD laminin receptor (67LR) is a cell-surface protein which binds laminin with high affinity. 67LR expression has been shown to increase in neoplastic cells, compared with normal tissues, and 67LR seems to play an important role during the first steps of neoplastic progression. In this study, 67LR expression was analysed during the morphological phases of breast cancer progression from normal tissue to invasive carcinoma. A total of 506 formalin-fixed, paraffin-embedded normal breast structures and lesions were stained by immunohistochemistry usign the MLuC5 monoclonal antibody, which is specific for 67LR. The results show that in normal breast and in any kind of breast lesion, myoepithelial and endothelial cells express 67LR. While 67LR is not seen in the epithelium of normal breast, cysts, adenosis, and benign tumours, it is expressed in the epithelial cells of several hyperplasias and carcinomas in situ, both ductal and lobular, as well as in all invasive carcinomas. The 67LR-positive cell subpopulation expands from hyperplastic lesions to invasive carcinoma, suggesting that 67LR could be related to the induction and progression of breast cancer. [less ▲]Detailed reference viewed: 4 (0 ULg)
67-kD laminin receptor expression correlates with worse prognostic indicators in non-small cell lung carcinomas.
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in Clinical Cancer Research : An Official Journal of the American Association for Cancer Research (1997), 3(2), 227-31
Tumor samples obtained from 72 patients resected for non-small cell lung cancer were stained immunohistochemically using an immunoperoxidase method and the MLuC5 monoclonal antibody specific for the 67 ... [more ▼]
Tumor samples obtained from 72 patients resected for non-small cell lung cancer were stained immunohistochemically using an immunoperoxidase method and the MLuC5 monoclonal antibody specific for the 67-kDa laminin receptor. Sixty-one of 72 patients (84.7%) displayed a MLuC5-positive reaction, which was usually localized in both the inner surface of the plasmatic membranes and the cytoplasm of neoplastic cells. When we compared the laminin receptor expression with clinicopathological and biological parameters such as histotype, grading, T status, N status, ploidy, proliferative activity, vessel invasion, and p53 protein accumulation, the following results were observed: (a) the mean expression of the receptor was higher in the group of patients with metastatic nodal involvement than in those with uninvolved lymph nodes (P = 0.02); (b) a high Ki-67 score (>13% of positive cells) was observed in tumors with a higher mean value of laminin receptor (P = 0.004); (c) the tumors harboring neoplastic emboli in their vessels showed a higher laminin receptor immunoreactivity (P = 0.02); and (d) a borderline association was found between the high mean value of laminin receptor immunopositivity and p53 accumulation in neoplastic cell nuclei (P = 0.05). Our observations indicate that detection of high tissue levels of 67-kDa laminin receptor is associated with an invasive phenotype in non-small cell lung cancer and may provide further information in the biological characterization of this type of cancer. [less ▲]Detailed reference viewed: 15 (0 ULg)
Expression of the Mr 67,000 laminin receptor is an adverse prognostic indicator in human thyroid cancer: an immunohistochemical study.
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in Clinical Cancer Research : An Official Journal of the American Association for Cancer Research (1996), 2(10), 1777-80
Increased expression of the Mr 67,000 laminin receptor (LR) is a consistent event which appears as cancer cells acquire an invasive and metastatic phenotype. The Mr 67,000 LR is one of the many laminin ... [more ▼]
Increased expression of the Mr 67,000 laminin receptor (LR) is a consistent event which appears as cancer cells acquire an invasive and metastatic phenotype. The Mr 67,000 LR is one of the many laminin-binding proteins able to interact with the major glycoprotein of basement membranes, laminin. The recent development of a specific monoclonal antibody directed against the Mr 67,000 LR MLuC5 has allowed us to study large retrospective groups of human cancers with the aim of correlating the Mr 67,000 LR expression to the clinical, pathological, and survival data of the patients. A significant correlation has already been established between the increased expression of Mr 67,000 LR and survival of patients with breast, colon, ovary, lung, and endometrial cancers. In this study, we investigated the possibility that the detection of Mr 67,000 LR in thyroid human cancers could also be of prognostic value. We analyzed the expression of Mr 67,000 LR with immunohistochemistry using MLuC5 antibodies in paraffin sections of 40 benign and 170 malignant thyroid human tumors. We found that Mr 67,000 LR was not usually detectable in normal thyroid tissues adjacent to the lesion. Only 3 of the 40 thyroid adenomas examined (7.5%) presented cells positive for Mr 67,000 LR. For the malignant thyroid tumors examined, we found that 22.3% of papillary thyroid carcinomas, 38% of follicular thyroid carcinomas, 40% of poorly differentiated carcinomas, 25% of medullary carcinomas, and 58.3% of anaplastic carcinomas expressed a high level of Mr 67,000 LR. Although no correlation between the Mr 67,000 LR expression and survival was found in patients with follicular thyroid carcinomas, papillary thyroid carcinomas, anaplastic carcinomas, and medullary carcinomas, there was a significant correlation in primary thyroid cancers. Our data represent the first extensive study of the Mr 67,000 LR expression in human thyroid cancers and strongly suggest that its detection could be of prognostic value in the investigation of primary thyroid cancers. [less ▲]Detailed reference viewed: 5 (0 ULg)