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H S Smith

Publications and source records attributed to H S Smith.

At least 37 records · Page 2Linked to original sources
PubMed1995

Tumor angiogenesis as a prognostic assay for invasive ductal breast carcinoma.

BACKGROUND: Tumor angiogenesis, as assayed by microvessel density, has been proposed as an independent prognostic marker for clinical outcome in breast cancer patients. PURPOSE: The present study evaluated the microvessel density assay and assessed its utility, alone and together with the evaluation of other tumor characteristics, in predicting outcome in patients with invasive ductal carcinomas. METHODS: In a blinded design, cases of invasive ductal carcinoma were selected from a registry containing the records of and tumor specimens from 386 breast cancer patients treated at the Massachusetts General Hospital from 1977 through 1982. After the exclusion of ineligible patients and inadequate specimens, 220 patients were included in the study; their median time of follow-up was 11.5 years. Half of these patients (n = 110) were positive for axillary lymph node metastases. Histologic sections of the tumors were stained immunocytochemically for factor VIII, a coagulation protein expressed by blood vessel endothelium, and for p53 protein. Independently, two analysts counted microvessels in three microscope fields selected from separate vascular regions of the tumor. Variability in microvessel scores between analysts and among different fields of the same tumor was summarized by the coefficient of variation. The kappa statistic tested for agreement between the analysts while correcting for chance agreement. The effects of tumor characteristics on metastasis-free survival and overall survival were tested univariately by the Harrington-Fleming rank test procedure. The effect of multiple factors on survival was tested under a Cox multivariate proportional hazards model. RESULTS: Microvessel count showed considerable variability between the two analysts and among regions within each tumor, with an overall concordance for tumor classification of 73%. Univariate analysis revealed no association between microvessel count and any other tumor or patient characteristic. Multivariate analysis indicated, for these patients, that nodal status and p53 staining predicted metastasis-free survival and that nodal status, estrogen receptor (ER) status and tumor grade predicted overall survival. CONCLUSIONS: Microvessel count showed much variation among different regions of each tumor. It did not predict metastasis-free survival or overall survival. Nodal status was the most powerful criterion to stratify these patients with invasive ductal carcinoma of the breast into different survival groups. Only ER status, tumor grade, and p53 staining had additional prognostic utility for these patients after they had been stratified by nodal status.

Analysis of Variance↗
PubMed1995

Selective cell culture of primary breast carcinoma.

We have used culture conditions which simulate the microenvironment of breast tumors for the isolation and propagation of primary breast tumor cells in vitro. In this monolayer setup, the mixture of cells dissociated from primary breast tumors is subjected to self-created gradients of oxygen and nutrients as well as metabolic waste and extracellular pH. The tumor populations isolated under these novel conditions have displayed phenotypic properties characteristic of breast carcinomas, including homogeneous expression of cytokeratin 19, and increased mitochondrial retention of the cationic dye rhodamine 123. Nonmalignant cultures from reduction mammoplasty were unable to survive these conditions. One tumor population which reached passage 10 was aneuploid for chromosomes 15 and 17, and displayed a p53 mutation in exon 8. These studies strongly suggest that the culture conditions described here can suppress the growth of normal breast cells, thereby allowing selective isolation of some populations of slow-growing primary tumor cells in vitro.

Breast↗
PubMed1995

Malignant breast epithelium selects for insulin-like growth factor II expression in breast stroma: evidence for paracrine function.

Paracrine interactions between stromal and epithelial cells are important influences on the growth and malignant behavior of breast cancers. Insulin-like growth factors I and II (IGF-I and II) are expressed by fibroblasts in benign and malignant breast lesions, and both are strong mitogens for a number of breast cancer epithelial cell lines in vitro. We have analyzed the stromal mRNA expression of IGF-I and IGF-II in matched sets of fibroblast cell lines derived from three locations in the affected breast of eight patients with breast cancer: (a) the breast tumor itself; (b) surrounding normal breast tissue; and (c) overlying breast skin. IGF-I expression was easily detected in all fibroblasts derived from normal breast tissue. In general, lesser amounts of IGF-I mRNA were detected in fibroblasts derived from breast tumors or skin. In contrast, IGF-II expression was detected at very low levels in only 3 of 8 normal breast fibroblasts, but was present in 6 of 8 tumor fibroblasts. IGF-II mRNA was expressed in all skin fibroblasts tested. IGF-II-negative stromal fibroblasts from normal breast, which were plated at low density and allowed to grow to confluence in the presence of MCF-7 breast tumor epithelial cells, demonstrated a marked increase in IGF-II mRNA expression. IGF-II in situ hybridization studies confirmed that IGF-II expression is seen at high levels in stroma of many invasive breast cancers but not normal breast. We conclude that paracrine influences, mediated by soluble factors released by breast tumor epithelium, are able to specifically increase expression of IGF-II in breast stroma, most likely by a process of clonal selection.

Breast↗
PubMed1995

Immunohistochemical localization of the plasminogen activator inhibitor-1 in breast cancer.

We used an immunohistochemical assay with an antigen-retrieval technique to study plasminogen activator inhibitor type-1 (PAI-1) expression in paraffin-embedded breast tissue samples at different stages of malignant transformation. We detected PAI-1 in 15/20 invasive tumors. In several cases staining was localized to the stromal component. PAI-1-positive fibroblasts could be seen surrounding tumor nodules or at tumor margins. In addition, tumor-infiltrating macrophages (13 cases) and endothelial cells (5 cases) were positive. In 11 specimens PAI-1-positive cancer cells were also detected. In 2 strongly positive cases secreted PAI-1 was visible in the extracellular matrix surrounding the cells. Six of 9 samples of carcinoma in situ (DCIS) were weakly positive. No staining of endothelial cells was visible in DCIS. Only a few positive adenomatous epithelial cells could be seen in 3 of 7 papillomas. All biopsies of normal breast tissue were negative, with the exception of one sample, obtained from a patient with a previous segmental mastectomy for DCIS. PAI-1 production by invasive breast cancers could reflect a general upregulation of the plasminogen activation system in proliferating cancer cells, as suggested by the finding that normal mammary epithelium cultures expressed PAI-1 in all cases examined. In addition, production of PAI-1 by the tumor stroma could protect the tumor itself from excessive proteolysis.

Base Sequence↗
PubMed1995

Outgrowth of BT-474 human breast cancer cells in immune-deficient mice: a new in vivo model for hormone-dependent breast cancer.

The effect of co-inoculation of basement membrane matrix, Matrigel and two human breast cancer cell lines, BT-474 and SK-BR-3, was tested in immune-deficient mice. Both cell lines strongly overexpress c-ErbB-2 protein, whereas only BT-474 is reported to be oestrogen receptor positive. Co-inoculation of Matrigel and BT-474 cells but not of Matrigel and SK-BR-3 cells resulted in tumour formation in bg-nu-xid mice. Oestrogen supplementation greatly enhanced tumorigenicity, but did not seem to be an absolute requirement. In vivo, BT-474 cells grow as a poorly differentiated adenocarcinoma with a doubling time of 9.4 +/- 1.1 days after inoculation into the neck region. A high proliferative activity appears to be compensated by a relatively high rate of cell loss, as BT-474 tumours contain many cells with the typical morphology of apoptotic cell death. Wild-type p53, known to participate in the induction of apoptosis, is absent from the tumours, whereas Bcl-2, known to inhibit apoptosis, is expressed at intermediate levels. BT-474 tumours tend to metastasise to the regional lymph nodes and are capable of forming micrometastatic lesions in the lung. Flow cytometrical analysis of DNA ploidy demonstrated no change in tumours compared with the cell line. Immunohistochemical and flow cytometrical detection of a number of hormone and growth factor receptors, transcription factors, cell adhesion molecules and proteins involved in proliferation and cell death demonstrated no major changes in ploidy and phenotype of tumours compared with the cell line. High expression of the cell-surface molecules c-ErbB-2 and episialin make it a potentially useful model for research in immune therapy.

Animals↗
PubMed1994

Deletion of two separate regions on chromosome 3p in breast cancers.

We have characterized the copy number of various loci on chromosome 3p in a series of breast cancers. To determine the precise region(s) involved, restriction fragment length polymorphism (RFLP) analysis for loss of heterozygosity (LOH) was performed using a panel of RFLP probes at 3p13-14, 3p21-22, and 3p24-26. The incidence of LOH at the three loci was 41, 32, and 45%, respectively. To validate the LOH data and to gain insights into the mechanisms resulting in LOH, chromosome 3 pericentromeric and 3p region-specific DNA probes were used to determine the DNA copy number by fluorescence in situ hybridization (FISH). Among 22 cases examined, 15 showed loss by both LOH and FISH, indicating that the dominant mechanism of LOH at 3p in breast cancer is a physical deletion. Two of the 22 cases showed loss by RFLP analysis but not by FISH, suggesting either mitotic recombination or loss and endoreduplication. In three cases, RFLP analysis indicated allelic imbalance, which was incorrectly interpreted as LOH, since a gain of one allele was suggested by FISH. By constructing a deletion map, we found that 2 separate regions, 3p13-14 and 3p24-26, were independently deleted in some breast cancers. Additionally, four cases had break points within the 3p24-26 region and one case had a homozygous deletion at 3p13, further supporting the hypothesis that there are tumor suppressor genes at both 3p13-14 and 3p24-26. Although high frequency of LOH was observed at the 3p21-22 region, there was no direct evidence supporting the existence of a breast cancer tumor suppressor gene there as opposed to codeletion with either the proximal or distal region.

Blotting, Southern↗
PubMed1994

Methylation of the estrogen receptor gene CpG island marks loss of estrogen receptor expression in human breast cancer cells.

Breast cancer is the most common malignancy in women and hormone resistance is a challenging problem in its treatment. Loss of estrogen receptor expression is an important means of hormone resistance, but the mechanisms involved are poorly understood. We now demonstrate a potential role for abnormal DNA methylation in transcriptional inactivation of the estrogen receptor gene. Estrogen receptor-negative human breast cancer cells growing in culture lack estrogen receptor mRNA, have a higher capacity to methylate DNA, and display extensive methylation of the CpG island in the 5' promoter region of the estrogen receptor gene, which would correlate with silencing of expression. These results suggest that abnormal methylation could account for transcriptional inactivation of the estrogen receptor gene and subsequent hormone resistance in some human breast cancers.

Breast Neoplasms↗
PubMed1994

Detection and mapping of amplified DNA sequences in breast cancer by comparative genomic hybridization.

Comparative genomic hybridization was applied to 5 breast cancer cell lines and 33 primary tumors to discover and map regions of the genome with increased DNA-sequence copy-number. Two-thirds of primary tumors and almost all cell lines showed increased DNA-sequence copy-number affecting a total of 26 chromosomal subregions. Most of these loci were distinct from those of currently known amplified genes in breast cancer, with sequences originating from 17q22-q24 and 20q13 showing the highest frequency of amplification. The results indicate that these chromosomal regions may contain previously unknown genes whose increased expression contributes to breast cancer progression. Chromosomal regions with increased copy-number often spanned tens of Mb, suggesting involvement of more than one gene in each region.

Breast Neoplasms↗
PubMed1994

A candidate tumor suppressor gene in human breast cancers.

We have isolated a candidate gene (designated Brush-1) located at 13q12-q13, proximal to the retinoblastoma gene (RB1). Brush-1 codes for a 4.7-kilobase mRNA expressed at high levels in normal breast epithelium but drastically reduced in 6 of 13 breast cancer cell lines. RB1 mRNA expression is at normal levels for 5 of these 6 lines suggesting a greater importance of Brush-1 for breast cancer. Four primary breast tumors which showed no loss of heterozygosity in the 13q13-q14 region demonstrated normal levels of mRNA for both Brush-1 and RB1. However, four additional primary tumors which displayed loss of heterozygosity for this region had markedly decreased levels of Brush-1 mRNA while maintaining the normal levels for RB1. This differential loss of Brush-1 mRNA expression for both primary tumors and breast cancer cell lines is the expected pattern for a breast tumor suppressor gene.

Base Sequence↗
PubMed1994

The urokinase receptor is expressed in invasive breast cancer but not in normal breast tissue.

We have studied expression of the urokinase receptor (u-PAR) in paraffin-embedded breast tissues at various stages of malignant progression. Forty-nine of 59 invasive cancers studied showed varying degrees of reactivity with our polyclonal antibody. The staining pattern was variable from case to case, although strong surface staining of tumor-associated macrophages was evident in most of these sections. In several cases, blood vessels in selected tumor areas were stained, as confirmed by treatment of adjacent sections with an anti-factor VIII antibody. These could represent regions of recent angiogenesis. Staining of tumor cells was observed in 21 of 59 cases and was extensive in 5 cases but confined to a small percentage of cells in the remaining 16 samples. In contrast with the cancer sections, all normal breast tissue (12 cases) was negative, as well as all fibroadenomas (4 cases), papillomas (5 cases), and hyperplasia with atypia (2 cases) studied. Seven carcinomas in situ examined were also negative for u-PAR, with the exception of few macrophages in two cases, suggesting that u-PAR expression may be associated with invasive tumor. The presence of u-PAR in human breast cancer and its absence from nonmalignant breast tissue supports the idea that plasminogen activation plays an important role in the process of cancer invasion. Expression of u-PAR on macrophages, endothelial cells, and cancer cells suggests the existence of complex paracrine interactions between tumor cells and stroma.

Base Sequence↗
PubMed1994

Loss of heterozygosity and p53 gene mutations in breast cancer.

Immunopositivity for the p53 tumor suppressor gene product was evaluated in 133 breast cancers and compared to loss of heterozygosity (LOH) at various chromosomal loci. The validity of p53 immunopositivity as an indicator for p53 mutations was verified using two molecular assays of p53 mutations: single stranded conformational polymorphism (32 cases) and/or direct sequencing (14 cases). Immunopositivity was highly specific for mutations, since all of 15 strongly immunopositive tumors (> 10% of the cells are positive) and seven of nine cases with borderline immunopositivity had mutations by molecular analysis but were somewhat lower in sensitivity, p53 mutations being also detected in three of 23 (13%) immunonegative cases. LOH was measured at loci on the following chromosomes (1p,q; 2p; 3p; 7q; 11p,q; 13q; 16q; 17p; 18p,q; and 22q) by Southern blotting, polymerase chain reaction amplification of restriction fragment length polymorphisms, or repetitive cytidine and adenine stretches (CA repeats). There was no association between p53 mutations and one measure of genomic instability, namely, high incidence of overall LOH. In contrast, p53 mutations strongly associated with LOH at two specific loci, 3p24-26 (P < 0.001) and 7q31 (P < 0.05). There was no association between p53 mutations and LOH at 17p (site of the p53 gene), suggesting that breast cancers often have only one defective allele of the p53 gene.

Base Sequence↗
PubMed1994

Cell proliferation in hyperplastic and in situ carcinoma lesions of the breast estimated by in vivo labeling with bromodeoxyuridine.

The proliferative activity of normal, benign proliferative, and carcinoma in situ (CIS) breast lesions was studied by in vivo labeling with 5-bromodeoxyuridine (BrdU) in 35 patients with concurrent breast carcinoma. The BrdU-labeled cells were identified on histologic sections by an anti-BrdU monoclonal antibody and an immunoperoxidase reaction. The percentage of BrdU-labeled cells in nonatypical hyperplasia (NAH) was higher (1.15 +/- 1.14%) than normal epithelial cells (0.67 +/- 0.56%, p = 0.066, borderline significance). This difference was very significant in postmenopausal women and disappeared in premenopausal women. No significant difference was found in the fraction of proliferating cells between NAH and atypical hyperplasia (AH): 1.15 +/- 1.14% for NAH versus 1.26 +/- 1.19% for AH. In CIS and in invasive carcinoma (ICA), a significant increase in the percent of BrdU-labeled cells was observed when compared to the normal epithelial cells or NAH (p < 0.001). No significant difference was found in the values of BrdU-labeled cells between CIS and ICA (p = 0.29). The percent of BrdU-labeled cells in benign breast lesions, including fibroadenoma, papilloma, and sclerosing adenosis, did not differ from those of the normal epithelial cells. The menopausal status of the patients did not affect the proliferative activity in NAH or CIS. No correlation was found in the fraction of BrdU-labeled cells between the normal and hyperplastic epithelial cells (r2 = 0.012) or between NAH and CIS (r2 = 0.406) or between CIS and ICA (r2 = 0.429).

Adult↗
PubMed1994

Tomographic imaging of the distal extremities using cone-beam collimation.

UNLABELLED: We evaluated the feasibility of cone-beam tomography (SPECT with a converging collimator) for detecting bone pathology of the distal extremities. METHODS: We examined 11 patients: seven with hand or wrist pain, three with ankle pain and one with tibial pain. Cone-beam tomography was performed using a high-resolution converging collimator with a 45-cm focal length. Tomograms were then compared to high-resolution planar images. RESULTS: Cone-beam tomography was successfully performed in all patients and tomograms were reconstructed in time for inclusion in the clinical report. In five patients, cone-beam tomography identified abnormalities that were equivocal or poorly defined on planar images. All other cone-beam studies provided the same information as the planar images. CONCLUSIONS: Tomographic imaging of the distal extremities can be successfully performed by using cone-beam tomography which has been found to be feasible and potentially useful in the clinical setting.

Adult↗
PubMed1993

Tumor labeling indices of primary breast cancers and their regional lymph node metastases.

BACKGROUND: Tumor labeling index has emerged as a strong predictor of the clinical course of women with breast cancer. This study investigated whether labeling index of primary tumors correlates with labeling indices of concurrent regional node metastases. METHODS: With appropriate written consent, preoperative in vivo infusion of the thymidine analogue 5-bromodeoxyuridine (BrdUrd) was used to label 109 human breast cancers. Labeled S-phase cells were identified immunohistochemically with an antibody specific to DNA-incorporated BrdUrd. Labeling index was the fraction of labeled nuclei in 2000 tumor nuclei. For 30 women, there was sufficient cancer in axillary lymph nodes to compare labeling indices in primary breast cancer and regional lymph node metastases. RESULTS: The 30 women were from 25 to 82 years of age. Tumors were from 1 to 12 cm in size and there were from 1 to 26 positive nodes. Tumor labeling index ranged from 0.1% to 34%, (mean, 11.1%; median, 10.3%) and axillary lymph node metastasis labeling index ranged from 0.1% to 27.7% (mean, 10.8%; median, 10.0%). There was strong correlation between primary tumor labeling index and regional lymph node metastases labeling index (r = 0.82, with 95% confidence interval 0.65-0.91). The correlation persisted within subgroups according to age, tumor size, number of positive nodes, and hormone receptor status. Primary tumor and lymph node metastases labeling indices also had statistically similar relationships with age, level of hormone receptors, tumor size, and number of positive nodes. CONCLUSIONS: Primary tumor and regional node labeling indices correlate strongly; the relationship is not influenced by age, level of hormone receptors, tumor size, or number of positive nodes.

Adult↗