Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD44 is thought to be a principal cell surface receptor for hyaluronic acid. Although the distribution of hyalulonic acid has been studied, little is known about the distribution of the CD44 molecule in the human skin and skin tumors. This study was undertaken to investigate the distribution of the CD44 molecule in normal human skin as well as in benign and malignant skin tumors. In normal skin, CD44 was expressed on 1) keratinocyte cell surfaces throughout the epidermis except for the granular and horny layers, 2) hair follicular cells, 3) eccrine sweat gland cells, and 4) cell surfaces of dendritic cells in the dermis. In skin tumors, although CD44 was expressed on the tumor cell surface of seborreic keratosis, Bowen's disease, and squamous cell carcinoma as in normal skin, we could not detect any CD44 expression on the cell surface of the tumor cells of basal cell carcinoma. However, CD44 positive dendritic cells were observed in the tumor islands of basal cell carcinoma. Phenotypic analysis suggested that these CD44 positive cells were melanocytes.
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PMID:CD44 expression in normal human skin and skin tumors. 753 64

This study was performed to determine the relationship between the expression of CD44, p53 and NM23 and the metastatic potential of colorectal cancer. Frozen sections of 56 cases of colorectal cancer were immunohistologically examined for the expression of CD44, p53 and NM23. Positive immunoreactivity was found in 30 of 56 cases (54%) in CD44, 26 of 56 (46%) in p53 and 20 of 56 in NM23 (36%), respectively. There was no significant relationship between the expression of these molecules and clinicopathological findings such as age, sex, size, location of tumor, histological type, serosal invasion, peritoneal dissemination, lymph node metastasis, extramural venous spread and tumor stage; however, when examining the relationship between the expression of these molecules and prognosis in terms of hepatic metastasis and recurrence after curative operation, a significant association was seen in the expression of CD44, but none in p53 and NM23. It was suggested that expression of CD44 could be used as a possible indicator to predict metastatic potential of colorectal cancer.
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PMID:Positive relationship between expression of CD44 and hepatic metastases in colorectal cancer. 753 7

Isoforms of the transmembrane glycoprotein CD44, generated by alternative RNA splicing, have been correlated to tumor dissemination. For evaluation of the potential role of CD44 variant isoforms in non-Hodgkin's lymphoma (NHL), the presence of CD44 isoforms was analyzed in a large panel of reactive and neoplastic lymphoid tissues by immunohistochemical staining, as well as detection of CD44 variant RNAs by the reverse transcriptase-polymerase chain reaction. Whereas the CD44 standard or hematopoietic isoform (CD44s), devoid of the variant regions, was expressed in all leukocyte subpopulations, the variant isoforms (CD44v) showed a highly restricted pattern of expression, mainly observed in epithelial layers of lymphoid tissues and subpopulations of leukocytes after stimulation. In addition to a strong expression of CD44s, variant isoforms containing CD44-6v in combination with other variant exons were observed predominantly in aggressive lymphoma and were associated with a shorter overall survival of patients (n = 138; P < .0001). Moreover, multivariate analysis indicated CD44-6v as a new independent prognostic parameter in high grade NHL in comparison with the risk groups defined by the International NHL Lymphoma Prognostic Factors Project (N Engl J Med 329:987, 1993).
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PMID:CD44 variant isoforms in non-Hodgkin's lymphoma: a new independent prognostic factor. 753 83

Splice variants of CD44 are overexpressed in human lung, breast, and colon carcinoma cell lines. This study was conducted to clarify the association between the expression of CD44 variant exons 8-10 and metastatic potential in human colorectal cancer. We found that the expression of a CD44 splice variant containing exons v8-10 was increased in all of 60 colorectal cancer specimens examined compared with matched normal colerectal mucosa, as determined by Northern blotting. Expression of CD44 variant exons 8-10 did not significantly correlate with histological type, depth of tumor invasion, lymphatic invasion, venous invasion, or lymph node metastasis. However, the level of CD44 variant exon 8-10 expression was significantly higher in carcinomas associated with liver metastasis than in those without liver metastasis. In addition, expression of CD44 variant exons 8-10 in the liver metastases was more intense than that in the primary colorectal cancers. These findings indicated that this domain of the CD44 glycoprotein encoded by exons v8-10 may play an important role in tumor hematogenous metastasis of human colorectal cancer.
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PMID:Expression of CD44 variant exons 8-10 in colorectal cancer and its relationship to metastasis. 753 3

CD44 expression in undifferentiated nasopharyngeal carcinoma has been analyzed by sequencing cDNA clones and by immunohistochemical staining using monoclonal antibodies specific for defined variant exons. Both sequencing and antibody staining revealed expression of CD44 variants containing exon v6, which has been linked to tumor metastasis. Although nasopharyngeal carcinoma typically contains a mixture of epithelial tumor cells and infiltrating lymphocytes, the CD44 v6 variant expression could be assigned to the tumor cells in biopsies and in a mouse xenograft system. Consistent with earlier studies, biopsies from about 60% of Chinese nasopharyngeal carcinoma cases expressed the Epstein-Barr virus LMP-1 protein, although all contained EBV DNA and expressed the EBER genes. The antibody specific for CD44 exon v6 generally gave a focal pattern of staining in epithelial tumor cells, but the expression of this variant did not appear to be related to the expression of the LMP-1 protein in the tumor.
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PMID:The expression of variant CD44 in nasopharyngeal carcinoma is unrelated to expression of LMP-1. 753 65

The prerequisite for a curative resection of metastases is their restriction to the key organs, the liver and lungs, in the sense of a limited dissemination. For long-term prognosis, the type of primary tumor as well as the radical resection of lung and liver metastases is essential. To improve the process of surgical indication and therapy of tumors, clear definitions for the terms "tumor recurrence" and "metastases" have been agreed upon. Research and clinical investigation have led to a better understanding of tumor-regulating factors, some of which are briefly described: Metastasis promoting factors include the lack of E-cadherin, which leads to a local penetration of basal membranes by tumor cells; CD44 seems to play an important role in cell-cell and cell-matrix interactions, apparently increasing the metastatic potential of tumors and reducing the long-term survival of patients. High levels of urokinase in primary tumors are also associated with a poorer prognosis, as well as plasminogen inactivator inhibitor PAI II, which plays a crucial role in tumor growth. Positive findings in bone marrow aspirates of patients with different malignancies, stained for cytokeratin 18, either are associated with higher recurrence rates in colon and breast cancer or can be correlated to the prognosis of patients with gastric cancer. Technical aspects of surgery for hepatic, pulmonary and skeletal metastases are presented and discussed with respect to curative and palliative indications.
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PMID:Surgical treatment of tumor metastases: general considerations and results. 753 64

Cell surface adhesion molecules, E-cadherin and exon v6 containing CD44 isoforms (CD44v6), were readily found in well-to-moderately differentiated urothelial cell lines but were down-regulated in poorly differentiated cell lines. One hundred and fifteen tumors of transitional cell carcinoma (TCC) were examined with E-cadherin and CD44v6 specific antibodies. Sixty-five (56.5%) tumors exhibited a preserved type while 50 (43.5%) showed a reduced type for CD44v6. Sixty-seven (58.3%) tumors were classified as the preserved type, and 48 (41.7%) were classified as the reduced type for E-cadherin. The staining pattern of E-cadherin was the same as that of CD44v6 in 87.0% (100 of 115) of tumors. The frequency of the reduced type was higher in poorly differentiated carcinomas (32 of 52 for CD44v6, p = 0.001; 27 of 52 for E-cadherin, p = 0.112) and tumors with an invasive growth pattern (22 of 27 for CD44v6, p < 0.001; 20 of 27 for E-cadherin, p < 0.001) than it was in well-differentiated carcinomas and tumors with expansile growth. However, the association with lymph node involvement or distant metastasis did not reach statistical significance. There was no difference in survival in reference to the expression patterns of CD44v6 and E-cadherin. Furthermore, neither marker was a significant prognostic factor for tumor recurrence and survival according to Cox's multiple variant regression analysis.
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PMID:Expressions of E-cadherin and exon v6-containing isoforms of CD44 and their prognostic values in human transitional cell carcinoma. 753 3

A parallel-plate flow chamber was used to quantify the detachment of normal cloned rat embryo fibroblasts (CREF) fibroblasts, ras-transformed CREF fibroblasts (CREF T24), and CREF T24 fibroblasts transfected with a Krev/RAP1A suppressor gene (HK B1) from a confluent monolayer of normal CREF fibroblasts to determine if the expression patterns of CD44 variants (mol wt 110 and 140 kDa) corresponded with detachment properties and metastatic potential. In the detachment assay, known shear stresses ranging from 20-24 dyn/cm2 were applied to the adherent cells and the number of cells detached from the monolayer after 180 s was determined. Results showed that cellular expression of CD44 variants correlated with the metastatic potential of the cells and with the cells' ability to detach from a monolayer of normal cells. Western blot analysis showed a low level of expression of the CD44 variants in the normal cell line, CREF, and the lowly metastatic cell line, HK B1. Detachment studies showed a low percentage of detachment of both of these cell lines from a normal cell monolayer. Tumor-derived (HK B1-T) and lung nodule-derived (HK B1-M) cell lines were established and both formed tumors and metastasis with reduced latency periods as compared to HK B1, but still showed a markedly delayed latency period compared to the highly metastatic cell line, CREF T24. Both of these cell lines showed a higher expression of the CD44 variants as compared to CREF and HK B1, and detached easier than CREF and HK B1. CREF T24 showed a much higher level of expression of the variants and had a higher percentage detachment than all other cell lines. To further test the role of the CD44 variants in the ability of the cells to detach from the normal monolayer, CREF cells were transfected with a DNA construct that constitutively expresses the CD44 variants and the detachment properties of three randomly selected clones were studied. Clones 2 and 3 showed a low level of expression of the CD44 variants after transfection and detached from the normal monolayer similar to CREF. Clone 1 showed a high level of expression of the CD44 variants and the detachment of these cells was significantly higher than CREF. From these results, it is concluded that in the five cell lines studied, expression of the CD44 variants play a significant role in the ability of the cells to detach from a monolayer of normal cells. It is hypothesized that this detachment may be an important component of a cell's ability to metastasize.
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PMID:Detachment of transformed cells. Role of CD44 variants. 753 6

Aberrant expression of the cell adhesion molecule CD44 has been detected in human tumors and the expression of specific CD44 isoforms (splice variants) has been shown to be associated with metastasis and poor prognosis in human malignancies. We used three different variant exon sequence-specific murine monoclonal antibodies to epitopes encoded by exon v5, exon v6, or exon v7-v8 of human variant CD44 to study the expression of CD44 splice variants by immunohistochemistry in human cervical cancer. One-hundred five patients with surgically treated squamous cell carcinomas of the cervix stages IB to IIB were included in the study. CD44 splice variants CD44v5, CD44v6, and CD44v7-8 were detected in 70, 67, and 26%, respectively. Tumors expressing exon v6 had significantly more often metastasized to the pelvic nodes (58 vs 79%, P = 0.04). Expression of exon v6 was significantly correlated with a greater probability of vascular space invasion (73 vs 50%, P = 0.04) and a significantly lower rate of inflammatory stromal reaction (48 vs 78%, P = 0.004). Patients suffering from tumors expressing splice variant CD44v6 showed poorer overall survival (P = 0.03). In cases with negative pelvic lymph nodes we found a poorer prognosis when tumors expressed CD44v6 (P = 0.01) or CD44v7-8 (P = 0.02). Among the investigated CD44 splice variants expression of exon v6 is the most promising prognostic marker in surgically treated cervical cancer.
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PMID:Splice variants of CD44 in human cervical cancer stage IB to IIB. 753 75

Knowing the differential expression of CD44 isoforms in intestinal- and diffuse-type gastric carcinomas, we used antibodies against the standard form of CD44 (CD44s) and the domain encoded by exon v6 (CD44v6) in 103 patients with primary gastric adenocarcinomas to explore the role of CD44 isoforms in metastases of both types of gastric cancer. Carcinomas of the intestinal type were more frequently CD44s and CD44v6 positive than carcinomas of the diffuse type (p = 0.034 for CD44s and p = 0.022 for CD44v6). The reactivity to these two antibodies did not correlate with histopathological and clinical prognostic factors in intestinal-type carcinoma. In contrast, expression of CD44v6 was associated with infiltrative tumor growth (p = 0.021), depth of invasion (p = 0.012), lymph node involvement (p = 0.005) and a higher incidence of distant metastasis (p = 0.069) in cancers of the diffuse type. CD44s-expressing diffuse-type tumors had a higher incidence of distant metastasis at presentation (p = 0.001), but expression of CD44s was not correlated with other clinicopathologic indices. For all cases, there was a nonsignificant association between CD44s expression and poor survival. Unexpectedly, there was also no significant difference in survival regarding expression of CD44v6 for all cases or the diffuse-type subset. This study showed the role of CD44v6 in invasion and metastases of diffuse-type gastric carcinoma and demonstrated the necessity of subclassifying tumor types when studying the clinical significance of CD44 in human cancers.
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PMID:Expression of CD44 and its clinical implication in diffuse-type and intestinal-type gastric adenocarcinomas. 753 3


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