Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD44 is the major hyaluronan cell surface receptor and functions as an adhesion molecule in many different cell types, including human breast epithelial cells. The coexpression of certain CD44 variants (CD44v), such as CD44v (v10/ex14), with CD44s (standard form) appears to be closely associated with human breast tumor metastasis. In this study we have established a stable transfection of CD44v (v10/ex14) cDNA into nontumorigenic human breast epithelial cells (HBL100) which contain endogenous CD44s. Our results indicate that coexpression of both CD44v (v10/ex14) and CD44s alters the following important biological properties of these cells: 1) there is a significant reduction in hyaluronic acid (HA)-mediated cell adhesion; 2) there is an increased migration capability in collagen-matrix gel; and 3) these cells constitutively produce certain angiogenic factors and effectively promote tumorigenesis in athymic nude mice. These findings suggest that coexpression of CD44v (v10/ex14) and CD44s may trigger the onset of cell transformation required for breast cancer development.
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PMID:Coexpression of CD44 variant (v10/ex14) and CD44S in human mammary epithelial cells promotes tumorigenesis. 913 Apr 62

To understand the relationship between CD44 gene expression and an established variable associated with aggressive behaviour in human breast cancer, we have studied a panel of 6 breast cell lines and 40 breast tumors selected primarily on the basis of estrogen receptor (ER) status. CD44 (standard form) mRNA was assessed by semi-quantitative RT-PCR, and CD44 variants incorporating exon v7 or v10 were studied by RT-PCR and Southern blot. While CD44 expression was not influenced by estrogen in ER+ve MCF-7 cells. CD44s expression was slightly higher (up to 2 fold) in ER-ve cells but there was a marked decrease in the range of CD44 variants incorporating exons v7 or v10. In microdissected tumors, the levels of CD44s showed no correlation with ER status but the pattern of expression of larger forms of CD44 incorporating variant exons v7 and v10 was significantly different (p = 0.005 and p = 0.015, respectively) between ER+ve and ER-ve tumors, reflecting the pattern seen in the cell lines. These findings suggest that the profile of CD44 expression in breast cancer may reflect cellular differentiation as indicated by the ER phenotype. The influence of these differences in CD44 expression on the increased metastatic potential of ER negative breast cancer remains to be determined.
Breast Cancer Res Treat 1997 Apr
PMID:CD44 variant expression and estrogen receptor status in breast cancer. 913 Dec 72

Primary infiltrating ductal carcinomas (IDCs) of the breast which measure less than 0.5 cm (T1a lesions) and between 0.5 and 1.0 cm (T1b lesions) are associated with a small risk of nodal metastasis. The role of axillary dissection in T1a and T1b breast cancer is controversial. In the absence of axillary dissection, comparable prognostic information might be obtained by examination of the primary cancer. The adhesion molecule CD44 represents a family of transmembrane proteins that mediate cell-cell and cell-matrix interactions. Previous investigators have correlated expression of CD44 and its isoforms with prognosis in breast cancer. We investigated the value of CD44 isoform expression as a predictor of nodal metastases in nonpalpable T1a and T1b IDC. Monoclonal antibody against the standard form of CD44 (CD44s) and polyclonal antibody directed against the variant isoform (CD44v6) was tested on 34 cases of nonpalpable node-negative infiltrating ductal carcinoma (IDC) less than 1.0 cm and 9 cases of nonpalpable node-positive IDC less than 1.0 cm. The expression of CD44s was significantly decreased in node-positive T1a and T1b IDC versus node-negative T1a and T1b IDC (11% vs 65%). In contrast, 97% of the node-negative IDC and 100% of the node-positive IDC expressed the CD44v6 isoform. We conclude that CD44s expression is significantly altered in T1a and T1b IDC with nodal metastases but that the CD44v6 isoform does not correlate with nodal metastases in nonpalpable stage T1a and T1b IDC.
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PMID:Role of CD44 in nonpalpable T1a and T1b breast cancer. 922 43

New isoforms of CD44 with alternatively spliced exons have recently been described. Expression of exon v6 seems to be of particular interest. It has indeed been associated with poorer outcome of breast cancer patients with node invasion at diagnosis. However, no data were available for patients N0M0 (with neither metastasis nor node invasion at diagnosis). Moreover, previous statistical analyses were realized using immunohistochemical methods to detect CD44v6 expression although several variants with exon v6 have been described. We investigated expression of isoforms containing CD44v6 using an RT-PCR approach and a panel of 25 normal breast specimens, 10 mammary fibroadenomas, 8 cystic samples and 52 primary breast tumors (38 invasive N0M0). Normal breasts, fibroadenomas, and cysts all express the same variant, A (with exon v6 only), while several transcripts are amplified in tumors. Expression of variants other than A correlates with acquisition of a malignant phenotype. Invasive cancers also express additional variants in comparison with in situ carcinomas. Metastasis capacities seem to be associated with transcription of variants other than A but also with no transcription of some of them, variants D (with exons v6 and v10) and L (with exons v6 to v10). Expression of variants D and L correlates with higher percentages of disease-free survival and better outcome. Expression of CD44 splice variants with exon v6, as detected by RT-PCR, might be a useful prognostic factor for breast cancer. However, since the series size is small, our results need to be confirmed by later studies on a larger number of patients.
Breast Cancer Res Treat 1997 Jul
PMID:CD44 isoforms with exon v6 and metastasis of primary N0M0 breast carcinomas. 926 6

The local expression of CD44 splice variants in human breast cancer tissue has been previously shown to be associated with metastasis. We show here that elevated systemic serum levels of CD44 splice variants occur in breast cancer and may represent a new tool for staging and differential diagnosis. Sera of node-negative and node-positive breast cancer patients in comparison with healthy control subjects were analyzed for serum CD44 (sCD44) and 2 different splice variants (v5 and v6). Node-positive breast cancer patients showed significantly (p < 0.01) elevated levels of sCD44-v5 and -v6 splice variants in comparison to node-negative patients and healthy controls. None of the node-negative breast cancer patients or healthy controls showed elevated levels of both sCD44-v5 and -v6. Interestingly, no differences were seen for serum levels of non-spliced sCD44-standard between the 3 groups. Soluble forms of CD44 variants may promote migration of tumor cells. This may occur through interference with tumor cell adhesion or by modulation of immune defense mechanisms.
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PMID:Soluble CD44 splice variants in metastasizing human breast cancer. 929 36

Primary breast cancers were shown to overexpress CD44 v5 and v6 at the plasma membrane. However, the clinical significance of this overexpression remains unclear. Overexpression of CD44 v5 and v6 in primary breast cancers was found to correlate with metastasis and poor prognosis by some investigators, yet this correlation could not be confirmed by others using different antibodies. In this study the influence of metastatic disease, the site of metastasis, and the amount of CD44 v5 and v6 expression in the primary tumor on serum levels of the soluble forms of CD44 v5 and v6 (sCD44 v5 and v6) in breast cancer patients was investigated. Soluble CD44 v5 and v6 serum levels were measured by enzyme linked immuno sorbent assay in a group of breast cancer patients who developed metastases in various organs and in another group of patients with single organ metastasis. For control, sCD44 v5 and v6 levels were measured in breast cancer patients who remained free of metastasis and in healthy blood donors. Expression of plasma membrane bound CD44 v5 and v6 in the primary tumors of the patients with metastasis in various organs was correlated to sCD44 v5 and v6 levels in serum. Furthermore the size of sCD44 v6 was analyzed by immunoblot using a monoclonal antibody directed against CD44 v6. When metastases were detected, sCD44 v5 and v6 serum levels were increased as compared to levels measured one month after tumor surgery in patients free of metastases (p= 0.0025 and p=0.0004). Six of 19 and 6 of 20 patients had sCD44 v5 and v6 serum levels above a cut-off level of 85 and 275 ng/mL, respectively. In these cases expression of CD44 v5 and v6 in the primary cancers was also elevated. Low sCD44 v5 and v6 serum levels were associated with weak expression of CD44 v5 and v6 in the respective primary cancers. As shown by statistical analysis of sCD44 v5 and v6 levels in 57 patients with single organ metastases, elevated sCD44 v6 levels but not sCD44 v5 levels were associated with metastases in liver or bone (p=0.0025). Immunoblot analysis of soluble CD44 proteins in serum revealed two CD44 v6 specific signals of approximately 120 and 170 kDa. Increased sCD44 v5 and v6 serum levels in patients with breast cancer were influenced by the amount of CD44 v5 and v6 expression in the primary tumor by the site of metastasis. Elevated sCD44 v6 serum levels were preferentially found in patients with metastases in liver or bone.
Breast Cancer Res Treat 1998 Jan
PMID:Soluble CD44 v5 and v6 in serum of patients with breast cancer. Correlation with expression of CD44 v5 and v6 variants in primary tumors and location of distant metastasis. 949 73

Aberrant expression of CD44 splice variants has been detected on a variety of human tumor cells. Overexpression of specific isoforms has been shown to be associated with metastasis and poor prognosis in breast cancer. We evaluated the possible utility of soluble CD44 splice variant v5 (sCD44v5) as a circulating, tumor-associated marker in breast cancer patients. Serum levels of sCD44v5 were determined in 147 healthy volunteers, in 53 patients with nonmalignant breast disease, in 85 patients with breast cancer at presentation, in 13 patients with recurrence and in 73 patients with active metastatic disease. Statistically, the levels at presentation in stages I-IV, in benign disease, and in a female control group were not significantly different. First longitudinal studies over 1-2 years in the follow-up of 28 patients who have remained tumor-free showed considerable between-patient variation while the intrapatient levels remained within relatively narrow limits. In patients with active metastatic disease, elevated levels of sCD44v5 (> 58 ng.ml-1) were detected in 50% of the cases with marked elevation in only 26%. In these cases, sCD44v5 correlated with the extent of metastatic disease and fell during clinical response to cytoreductive therapy. In comparison with CA15-3 in the patients' follow-up serum levels of sCD44v5 proved to be much less sensitive concerning lead time, percentage of raised serum levels at the time of recurrence and in metastatic disease. The value of sCD44v5 determinations in breast cancer patients was further limited by the poor diagnostic specificity of this marker due to elevated levels in smokers and chronic inflammatory disease.
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PMID:Evaluation of soluble CD44 splice variant v5 in the diagnosis and follow-up in breast cancer patients. 952 62

To investigate the role of tumor angiogenesis, laminin and CD44 expression in metastatic potential of breast cancers, 35 early-stage (T1) and/or low-grade (grade 1) invasive breast carcinomas including 18 metastasizing and 17 non-metastasizing cases were analyzed in the present study. Angiogenesis was assessed by a stereologic method after immunohistochemical staining of vascular endothelium for factor VIII. The quantification of the tumor vascularization was based on the vascular surface density (VSD) and the microvessel number (NVES). The expressions of laminin and CD44 were evaluated by scoring the intensity and distribution of the immunostaining. The assessment of NVES and VSD resulted in a statistically significant difference between the two groups (P < 0.05, independent-samples t-test). In the breast cancers with metastatic spread, NVES was found to be 16.0+/-2.9 mm(-2) whereas it was 8.1+/-0.7 mm(-2) in the metastasizing group. VSD was found to be 59.0+/-12.6 mm(-1) in the metastasizing group and was significantly lower in the non-metastasizing group (33.8+/-2.6 mm[-1]). Immunohistochemistry exhibited strongly positive staining for CD44 in 22% of the breast cancers with metastasis, while 65% of the non-metastasizing cases were found to be negative. The statistical analysis also resulted in a significant difference (P = 0.034, chi2 test). However, the immunohistochemical staining for laminin did not yield any significant difference (P = 0.347, chi2 test). Approximately half of the cases being either metastasizing or non-metastasizing stained weakly positive for laminin. We concluded that angiogenesis and CD44 expression in breast cancers correlated significantly with lymph node or distant metastasis. However, the immunodetection of laminin expression in our study did not help to evaluate its role in the metastatic potential of breast cancers. We concluded that vascular parameters, such as an increase in microvessel number, and CD44 expression might be useful prognostic indicators of metastasis in breast cancer.
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PMID:The role of angiogenesis, laminin and CD44 expression in metastatic behavior of early-stage low-grade invasive breast carcinomas. 957 Mar 48

The aim of this study was to investigate certain genes for their suitability as molecular markers for detection of breast carcinoma cells using the reverse transcriptase-polymerase chain reaction (RT-PCR). RNA was prepared from MCF-7 breast carcinoma cells and peripheral blood leucocytes of healthy female volunteers. This RNA was screened for mRNA of MUC1, cytokeratin 19 (CK19) and CD44 (exons 8-11) by RT-PCR and the results validated by Southern blots. Variable degrees of expression of MUC1 and CD44 (exons 8-11) were detected in normal peripheral blood, rendering these genes non-specific for epithelial cells and therefore unsuitable for use as markers to detect breast carcinoma cells. Although CK19 mRNA was apparently specific, it was deemed unsuitable for use as a marker of breast cancer cells in light of its limited sensitivity. Furthermore, an attempt at using nested primers to increase sensitivity resulted in CK19 mRNA being detected after two amplification rounds in blood from healthy volunteers.
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PMID:Putative markers for the detection of breast carcinoma cells in blood. 957 23

We examined the expression of CD44 isoforms in samples of breast cancer tissues from 95 patients by reverse transcription-polymerase chain reaction and immunohistochemistry, and tried to correlate the results with survival period. At the RNA level, expression of exon v2 was observed in 33 (35%) and that of v6 in 69 (73%) of the 95 specimens. Patients with CD44v2 mRNA expression had significantly shorter survival times than those with v2-negative tumors (P = 0.05), but there was only a weak correlation, if any, between v6 mRNA expression and overall survival (P = 0.06). Tumor tissue from 22 (23%) and 72 (76%) patients showed positive immunoreactivity with monoclonal antibody (mAb) M23.6.1. (CD44v2) and mAb 2F10 (CD44v6), respectively. Immunohistochemical evidence of CD44v2 peptide expression correlated with overall survival (P = 0.02), but there was no such association with CD44v6 expression in these tumors (P = 0.67). There were significant correlations between v2 immunoreactivity and higher histological grade and lower levels of estrogen and progesterone receptor. There was no significant correlation between v6 immunoreactivity and such clinicopathological characteristics. Although the expression of v2 was significantly associated with reduced overall survival, it was not an independent prognostic factor because it also correlated with progesterone receptor status. These findings suggest that v2 isoform expression might have more value than v6 expression for clinical use.
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PMID:CD44 variant isoform expression and breast cancer prognosis. 960 Jan 22


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