Soluble CD44 splice variants in metastasizing human breast cancer

Cationic conjugated polymer/fluoresceinamine-hyaluronan complex for sensitive fluorescence detection of CD44 and tumor-targeted cell imaging

Simple, rapid, and sensitive detection of CD44 is of paramount importance since it plays pivotal roles in tumor initiation, growth and metastasis. Herein, we describe a novel method for sensitive, visual and facile fluorescence detection of CD44 and CD44-mediated cancer cell imaging, using a probe based on cationic conjugated polymer (CCP)-PFEP and fluoresceinamine-hyaluronan (FA-HA). HA is an anionic natural glycosaminoglycan that can specifically bind to the overexpressed CD44 on various kinds of cancer cells. PFEP and FA-HA formed a complex through electronic interactions, resulting in a highly efficient fluorescence resonance energy transfer (FRET) from PFEP to FA-HA; moreover, the efficiencies of FRET correlated with the concentrations of CD44 because the specific binding of HA-CD44 would separate FA-HA away from PFEP. This method did not require laborious and expensive dual-labeling or protein-labeling needed in previously reported detection methods of CD44. Just mix the sample and test solution containing the PFEP/FA-HA complex, and the results allowed naked-eye detection by observing fluorescent color of solutions with the assistance of a UV lamp. Most importantly, the use of a conjugated polymer with excellent amplification property as well as the specific binding of HA-CD44 endowed this method with high sensitivity and specificity, making it applicable for reliable quantitative detection of CD44. Furthermore, the PFEP/FA-HA complex formed nanoparticles in aqueous solution, and the nanoparticles can be selectively taken up by MCF-7 cells (cancer cell) through the HA-CD44 interaction, thereby giving rise to a dual-color tumor-targeted imaging probe with good photostability. The development of this fluorescent probe showed promising potential to make a reliable and routine method available for early diagnosis of cancer.

A Comprehensive Analysis of CXCL12 Isoforms in Breast Cancer1,2

CXCL12-CXCR4-CXCR7 signaling promotes tumor growth and metastasis in breast cancer. Alternative splicing of CXCL12 produces isoforms with distinct structural and biochemical properties, but little is known about isoform-specific differences in breast cancer subtypes and patient outcomes. We investigated global expression profiles of the six CXCL12 isoforms, CXCR4, and CXCR7 in The Cancer Genome Atlas breast cancer cohort using next-generation RNA sequencing in 948 breast cancer and benign samples and seven breast cancer cell lines. We compared expression levels with several clinical parameters, as well as metastasis, recurrence, and overall survival (OS). CXCL12-α, -β, and -γ are highly co-expressed, with low expression correlating with more aggressive subtypes, higher stage disease, and worse clinical outcomes. CXCL12-δ did not correlate with other isoforms but was prognostic for OS and showed the same trend for metastasis and recurrence-free survival. Effects of CXCL12-δ remained independently prognostic when taking into account expression of CXCL12,CXCR4, and CXCR7. These results were also reflected when comparing CXCL12-α, -β, and -γ in breast cancer cell lines. We summarized expression of all CXCL12 isoforms in an important chemokine signaling pathway in breast cancer in a large clinical cohort and common breast cancer cell lines, establishing differences among isoforms in multiple clinical, pathologic, and molecular subgroups. We identified for the first time the clinical importance of a previously unstudied isoform, CXCL12-δ.

Hyaluronic acid-based nanocarriers for intracellular targeting: interfacial interactions with proteins in cancer

The therapeutic efficacy of most drugs is greatly depends on their ability to cross the cellular barrier and reach their intracellular target sites. To transport the drugs effectively through the cellular membrane and to deliver them into the intracellular environment, several interesting smart carrier systems based on both synthetic or natural polymers have been designed and developed. In recent years, hyaluronic acid (HA) has emerged as a promising candidate for intracellular delivery of various therapeutic and imaging agents because of its innate ability to recognize specific cellular receptors that overexpressed on diseased cells. The aim of this review is to highlight the significance of HA in cancer, and to explore the recent advances of HA-based drug carriers towards cancer imaging and therapeutics.

The concentration of CD44 is increased in hematopoietic stem cell grafts of patients with acute myeloid leukemia, plasma cell myeloma, and non-Hodgkin lymphoma

CONTEXT

In autologous hematopoietic stem cell transplantation (autoHSCT), malignant cells remaining in the graft may re-engraft leading to relapse of the original disease. CD44 is known to play a role in the engraftment of leukemia-initiating cells and is shed from the surface of malignant cells. Soluble CD44 is a cleaved fragment, which is found in the serum of patients with metastasized epithelial and hematologic malignancies and in some other cancers, and has been demonstrated to be correlated with clinical outcome.

OBJECTIVES

To investigate (1) a possible correlation between the concentration of CD44 in an autoHSCT graft and the type of hematologic malignancy and (2) a possible correlation between the concentration of CD44 in the autoHSCT graft with clinical outcome after autoHSCT.

DESIGN

We measured CD44 in 157 hematopoietic stem cell grafts from patients with hematologic malignancies and from 43 healthy donors by enzyme-linked immunosorbent assay.

RESULTS

Levels of CD44 were almost 2-fold higher in the patients' grafts. Highest levels were found in the grafts of patients with acute myeloid leukemia, diffuse large B-cell lymphoma, and plasma cell myeloma, congruent with known CD44 expression levels in these malignancies. The survival advantage among patients with CD44 levels less than 22 000 ng/mL was highly statistically significant.

CONCLUSION

These results show that CD44 levels in an autoHSCT graft may be linked to clinical outcome after autoHSCT.

Increased soluble CD44 concentrations are associated with larger tumor size and lymph node metastasis in breast cancer patients

PURPOSE

CD44 is a cell surface glycoprotein involved in cell-cell and cell-substrate interactions, which may be shed or released into circulation by proteolytic enzymatic mechanisms. Alternative splicing of CD44 and aberrant levels of soluble CD44 variants in the serum of cancer patients have been correlated to tumor progression and metastasis in different tumors including breast cancer. In this study we evaluated the clinical value of CD44 serum levels (sCD44) in patients with primary breast cancer.

METHODS

Concentrations of soluble isoforms sCD44std, sCD44v5 and sCD44v6 were determined with a sensitive ELISA and normalized against the total protein concentration (TP). Pre-operative serum samples from 82 patients and 67 age-matched healthy blood donors were analyzed. The results were correlated to clinico-pathological parameters (tumor size, grading, lymph node metastasis, etc.).

RESULTS

In sera of breast cancer patients, we detected elevated concentrations of sCD44v6 (P = 0.0001) and total protein TP (P = 0.0001) in comparison to healthy controls, whereas overall sCD44 (sCD44std) and sCD44v5 did not differ. Patients with sCD44v6-concentrations above the 75%-percentile showed an increased T stage (2.9 cm vs. 1.8 cm) as well as a higher risk for lymph node metastasis (55% vs. 35%). In breast cancer patients with lymph node metastasis the median value of sCD44v6 was significantly higher (P = 0.025) in comparison to patients without lymph node metastasis and healthy controls.

CONCLUSIONS

Our data suggest an upregulated expression of alternatively spliced soluble CD44 isoforms in breast cancer patients. The specific alterations of certain CD44 isoform concentrations (especially sCD44v6) may reflect disturbances of the nuclear splicing machinery in tumor cells. The clinical significance of our findings are underlined by the positive correlation of elevated sCD44v6 concentrations and lymph node metastases (r (s) = 0.25).

Correlation of cytologic examination with ELISA assays for hyaluronan and soluble CD44v6 levels in evaluation of effusions

Hyaluronan (HA) and its major cell surface receptor, CD44, play an important role in tumor growth, proliferation, neovascularization, and invasion. CD44 is an integral transmembrane protein and exists in standard form (CD44s), as well as a myriad of CD44 variants isoforms (CD44v1-v10). Functional fragments of the CD44 can be released from the cell membrane by proteolytic cleavage of extracellular domain producing soluble CD44. Although studies have proposed the use of serum HA and soluble CD44, specifically soluble CD44v6 (sCD44v6) levels, as a tumor markers, its diagnostic utility in body fluid samples has not been clearly established. The purpose of this study was to correlate HA and sCD44v6 levels in effusions with the cytology diagnosis and to assess their usefulness in differentiating between malignant and nonmalignant effusions. In this retrospective study we evaluated HA and sCD44v6 contents in 20 effusions from cytologically positive samples and 10 effusions from cytologically negative samples. Corresponding cytopathology slides were reviewed to confirm the diagnoses. Malignant effusions included 18 cases of metastatic adenocarcinomas (9 ovarian, 3 breast, 3 pulmonary, 3 adenocarcinoma of unknown primary) and 2 cases of lymphomas. The level of HA and sCD44v6 were measured using a sandwich enzyme-linked immunoadsorbent assay. For HA, we used hyaluronic acid quantitative test kit (Corgenix, Denver, CO) and for sCD44v6 we used Human sCD44v6 Instant ELISA (Bender MedSystems, Vienna, Austria). HA concentrations (microg/mL) and sCD44v6 concentrations (ng/mL) were calculated and correlated with clinical data as well as cytodiagnosis. The mean concentration of HA (22.42 +/- 5 microg/mL) and sCD44v6 (70 +/- 42 ng/mL) in the cytologically positive samples was significantly higher than those in the cytologically negative samples for HA (5.5 +/- 5 microg/mL, P < 0.01) and sCD44V6 (17 +/- 10 ng/mL, P < 0.01). Using benign effusions as control and the upper limits of its mean levels for HA (10.5 microg/mL) as the positive boundary value, HA levels exceeded the boundary line in 17 out of 20 malignant effusions and 2 out of 10 benign effusions. Meanwhile, sCD44v6 exceeded the boundary line (27 ng/mL) in 18 out of 20 malignant effusions and 3 out of 10 benign effusions. The calculated sensitivity and specificity of this assay to the diagnosis of malignant effusions were 85 and 80% for HA and 90 and 70% for CD44v6, respectively. We conclude that the HA and sCD44v6 levels in body fluids correlate with the cytology diagnosis and could be used as an ancillary study in cytology to differentiate nonmalignant from malignant effusions.

Salivary Soluble CD44: A Potential Molecular Marker for Head and Neck Cancer

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) is a debilitating disease which is cured only 50% of the time. If diagnosed early, survival rates could reach 80%, but there is currently no practical method for early detection. CD44 comprises a family of isoforms that, in certain tumors, are alternatively spliced and overexpressed in tissues and circulation. Here we examine salivary soluble CD44 (solCD44) expression in HNSCC patients and normal controls to determine its potential as a screening tool.

METHOD

We did a solCD44 ELISA on saliva from 26 HNSCC patients, 10 normal volunteers, conditioned media (CM) of 4 HNSCC cell lines, and 1 CD44-negative cell line (COS-7). Western blot was done on CM from 2 HNSCC cell lines (UMSS11B and FaDu), COS-7, 3 HNSCC, and 2 normal saliva specimens to verify ELISA antibody specificity. SolCD44 levels were significantly elevated in HNSCC patients compared with normal controls (7.85 ng/mL for HNSCC patients and 1.09 ng/mL for normal controls, P < 0.001).

RESULTS

The test detected 79% of mucosally invasive HNSCC using preliminary cutoff points. SolCD44 levels did not vary significantly with tumor size, stage, recurrence, history of radiation treatment, or tobacco and alcohol risk factors. A 65 to 75 kDa band, corresponding to solCD44, was detected in all of the HNSCC cell line CM and saliva whereas normal samples showed a fainter band or were undetectable.

CONCLUSION

In this preliminary analysis, the salivary solCD44 ELISA seems to effectively detect HNSCC at all stages. Further study is indicated because early detection is clearly important in this disease.

Differentiation of mesothelioma from adenocarcinoma in serous effusions: The role of hyaluronic acid and CD44 localization

Differentiating cells of mesothelial origin from adenocarcinoma (ACA) based on morphology alone can be a diagnostic challenge, especially in cytological specimens. Malignant mesothelioma (MM) is characterized by accumulation of abundant intracellular hyaluronic acid (HA), a feature that is not reported in ACA. The purpose of this study was to evaluate the significance of cellular HA using an HA-specific binding peptide (HABP) and the expression of its principal receptor, the standard CD44 molecule (CD44S). Archival paraffin-embedded cell blocks of serous fluids from 28 cases of reactive mesothelial cells, 14 cases of MM, 20 cases of metastatic ovarian carcinomas, 17 cases of metastatic breast carcinomas, 12 cases of metastatic lung ACA, and 12 cases of metastatic gastrointestinal ACA were stained with HA using a biotinylated HABP and CD44S. Positive staining was defined as droplet to diffuse cytoplasmic staining for HA and uniform membranous staining for CD44S. All MMs and 93% (26/28) of the benign mesothelial cells were positive for intracytoplasmic HA vs. none of ACAs. CD44S was expressed in 100% (28/28) of mesothelial hyperplesia, 86% (12/14) of MMs, 70% (14/20) of ovarian carcinomas, 29% (5/17) of breast carcinomas, 25% (3/12) of gastrointestinal ACAs, and 8% (1/12) of lung ACAs. In MM and reactive mesothelial cells, CD44S stained cell membranes diffusely with highlights on the villous surfaces and in ACA it was focal and confined to cell membranes. Immunostaining with HA is a reliable marker that can distinguish between cells of mesothelial origin (reactive mesothelial cells and MM) and ACA. The CD44S staining pattern of cells of mesothelial origin is of diagnostic significance. CD44 may prove useful in conjunction with other stains in the differential diagnosis of mesothelioma and ADA.

CD44 in cancer

CD44 is a multistructural and multifunctional cell surface molecule involved in cell proliferation, cell differentiation, cell migration, angiogenesis, presentation of cytokines, chemokines, and growth factors to the corresponding receptors, and docking of proteases at the cell membrane, as well as in signaling for cell survival. All these biological properties are essential to the physiological activities of normal cells, but they are also associated with the pathologic activities of cancer cells. Experiments in animals have shown that targeting of CD44 by antibodies, antisense,and CD44-soluble proteins markedly reduces the malignant activities of various neoplasms, stressing the therapeutic potential of anti-CD44 agents. Furthermore, because alternative splicing and posttranslational modifications generate many different CD44 sequences, including, perhaps, tumor-specific sequences, the production of anti-CD44 tumor-specific agents may be a realistic therapeutic approach. However, in many cancers (renal cancer and non-Hodgkin's lymphomas are exceptions), a high level of CD44 expression is not always associated with an unfavorable outcome. On the contrary, in some neoplams CD44 upregulation is associated with a favorable outcome. Even worse, in many cases different research grows analyzing the same neoplastic disease reached contradictory conclusions regarding the correlation between CD44 expression and disease prognosis, possibly due to differences in methodology. These problems must be resolved before applying anti-CD44 therapy to human cancers.

The influence of tobacco smoking on adhesion molecule profiles

Sequential interactions between several adhesion molecules and their ligands regulate lymphocyte circulation and leukocyte recruitment to inflammatory foci. Adhesion molecules are, therefore, central and critical components of the immune and inflammatory system. We review the evidence that tobacco smoking dysregulates specific components of the adhesion cascade, which may be a common factor in several smoking-induced diseases. Smoking causes inappropriate leukocyte activation, leukocyte-endothelial adhesion, and neutrophil entrapment in the microvasculature, which may help initiate local tissue destruction. Appropriate inflammatory reactions may thus be compromised. In addition to smoke-induced alterations to membrane bound endothelial and leukocyte adhesion molecule expression, which may help explain the above phenomena, smoking has a profound influence on circulating adhesion molecule profiles, most notably sICAM-1 and specific sCD44 variants. Elevated concentrations of soluble adhesion molecules may simply reflect ongoing inflammatory processes. However, increasing evidence suggests that specific soluble adhesion molecules are immunomodulatory, and that alterations to soluble adhesion molecule profiles may represent a significant risk factor for several diverse diseases. This evidence is discussed herein.

The prognostic significance of CD44s and CD44v6 expression in stage two breast carcinoma: an immunohistochemical study

AIMS

Expression of the v6 variant isoform of CD44 has been causally associated with the development of metastases. This study, using immunohistochemical techniques, examined the prognostic significance of CD44s and CD44v6 expression.

METHODS

A cohort of 109 women presenting with stage 2 breast cancer, with a minimum follow-up of 5 years, were assessed.

RESULTS

Eighty percent of patients demonstrated CD44v6 expression on immunohistochemical studies. CD44v6 expression in tissue sections was found to be independent of age, tumour size, grade, and lymph-node status. No significant association was demonstrated between CD44v6 expression and either disease-free or overall survival. Similar findings were observed for CD44s.

CONCLUSIONS

CD44s and CD44v6 do not appear to be useful as prognostic indicators in early breast cancer. The increased expression of variant CD44 isoforms seen in breast neoplasia may merely be a marker for loss of control of alternative splicing within tumour tissue.

Soluble CD44 inhibits melanoma tumor growth by blocking cell surface CD44 binding to hyaluronic acid

Proteolytic cleavage of the extracellular domain of CD44 from the surface of cells has been observed recently in different cell types. In cell culture supernatants of human melanoma cell lines a 70 kDa soluble CD44 protein (solCD44) was detected at concentrations of 250-300 ng/ml. Protease inhibitor studies revealed that serine proteases and metalloproteases are involved in the cleavage of CD44 from the surface of melanoma cells. To analyse a possible function of soluble CD44 a human malignant melanoma cell line was stably transfected with cDNAs encoding either wild type soluble CD44s or mutated forms with defective HA binding properties (CD44sR41A and CD44sR150A/R154A). Soluble CD44s almost completely inhibited hyaluronic acid binding by melanoma cells, whereas soluble CD44 mutated in the HA binding domain had no effect. When cultivated on hyaluronic acid, melanoma cell proliferation was induced by 30% for both the parental and the control transfected cells. This increase in proliferation was blocked completely in solCD44s-secreting transfectants, whereas solCD44sR41A and solCD44sR150A/R154A-secreting cells again showed hyaluronic acid-induced cell proliferation. These cell lines were subcutaneously injected into MF1 nu/nu mice to compare their growth as tumors in vivo. Compared to tumors derived from parental and control transfected cells, we observed a dramatic reduction of primary tumor growth with solCD44s expressing MM cells. Transfectants expressing solCD44s mutated in the HA binding domain in contrast developed fast-growing primary tumors. These results provide strong evidence that direct solCD44 interactions with hyaluronic acid interfere competitively with processes induced by hyaluronic acid binding to surface CD44. Autocrine, or drug-induced secretion of solCD44 by human melanoma cells may thus exert potent antitumoral effects in vivo.

Identification and characterization of CD44RC, a novel alternatively spliced soluble CD44 isoform that can potentiate the hyaluronan binding activity of cell surface CD44

Soluble CD44 proteins generated by proteolytic cleavage or aberrant intron retention have been shown to antagonize the ligand binding activity of the corresponding cell surface receptor, inducing apoptosis and inhibiting tumor growth. Interestingly, such findings appear to contradict recent studies demonstrating a correlation between the presence of high levels of soluble CD44 in the serum of cancer patients and poor prognosis. In the present study, we report the cloning of a novel, naturally occurring, differentially expressed, soluble CD44 isoform, designated CD44RC, which, in contrast to previously described soluble CD44 proteins, can dramatically enhance the hyaluronan binding activity of cell surface CD44. Sequence analysis suggests that CD44RC is generated by an alternative splicing event in which the 3' end of CD44 exon 2 is spliced into an internal splice acceptor site present within exon 18, altering reading frame and giving rise to a soluble protein with a unique COOH terminus. Functional studies suggest that CD44RC enhances hyaluronan binding by adhering to chondroitin sulfate side-chains attached to cell surface CD44, generating a multivalent complex with increased avidity for hyaluronan.

Serum soluble CD44 in pediatric patients with acute leukemia

PURPOSE

CD44 is an adhesion molecule expressed on a variety of cells, and its level correlates with the metastatic potential of malignant tumors. Serum concentrations of soluble CD44 (sCD44) are elevated in various cancers. The purpose of this study was to measure the serum concentrations of CD44 in pediatric patients with acute leukemia.

PATIENTS AND METHODS

Fourteen pediatric patients with acute leukemia were studied. The authors measured the serum concentration of sCD44 by enzyme-linked immunosorbent assay before and after therapy. The concentrations were compared with those of 15 control healthy children and 10 patients with bacterial infections.

RESULTS

The mean serum concentration of sCD44 at presentation was significantly higher in patients than in control subjects, but decreased to a normal range in complete remission after chemotherapy. There was no difference in sCD44 concentrations between patients with acute lymphocytic leukemia and those with acute myeloid leukemia. Serum concentrations of sCD44 did not correlate with lactic dehydrogenase concentrations or bone marrow nucleated cell counts and only weakly with peripheral leukocyte count. sCD44 levels in patients with bacterial infections were similar to those of control subjects.

CONCLUSION

Serum concentration of sCD44 may reflect disease status in pediatric patients with acute leukemia and might be a useful tumor marker in these patients.

Soluble CD44: quantification and molecular repartition in plasma of patients with colorectal cancer

Based on the important role of CD44 in tumour progression and metastasis, we evaluated, in a prospective study, plasma-soluble CD44 (sCD44) as a serum marker in colorectal cancer. Blood plasma specimens from 89 patients with colorectal neoplasm, 22 patients with a gastrointestinal disease and 23 healthy donors were analysed for quantitation (ELISA assay) and purification of sCD44. The concentration of sCD44, indicating the concentration of all isoforms, was significantly higher in patients with colorectal cancer and intestinal disease than in normal individuals, but no significant differences were found between the two groups. We found no association between plasma levels and staging of the colorectal cancer patients according to Astler and Coller. A two-step batch purification combining ion exchange and immunoaffinity chromatography, followed by Western blot analysis, revealed a complex pattern with a major band corresponding to the standard form of CD44 and minor bands that may correspond to larger variant forms. No particular sCD44 isoform was clearly associated with anatomopathological or biological information.

Prognostic value of CD44 variant expression in primary breast cancer

CD44 is a family of cell surface transmembrane glycoproteins members which differ in the extracellular part by sequences derived by alternative splicing of 10 variant exons (v1-v10). CD44 proteins containing such variant sequences have been implicated in tumor metastasis formation. Here, we have evaluated the expression of CD44 variants by immuno-histochemistry in primary breast cancer samples of 237 node-negative and 230 node-positive patients. For the analysis of samples derived from node-negative patients, the exon-specific antibodies used were DIII, vff7 and vff18 (v6), vff17 (v7/v8), fw11.24 (v9) and vff16 (v10). With the different antibodies which recognize v6 epitopes, the majority of tumors were positively stained (> or = 65% of the tumors) with varying intensities. Thirty-nine percent of the tumors were positively stained with the antibody vff16, and approximately half of the tumors with the antibodies vff17 and fw11.24. The expression of CD44 v6 epitopes in tumors from node-negative patients was associated with a favorable prognosis, both upon univariate and multivariate analysis. The expression of CD44 v7/8, v9 or v10 epitopes was not significantly related with relapse-free survival. Samples from node-positive patients were only examined with the antibodies vff7, vff17 and vff18. The staining with none of these antibodies was correlated with the length of relapse-free survival of the patients. Our data suggest that, generally, the usefulness of knowledge of CD44 variant expression is of limited value for assessing the risk of relapse in patients with primary breast cancer. However, the expression of exon v6 of CD44 may be a marker to identify patients with a relatively favorable prognosis in node-negative patients.

Serum CD44 in non-Hodgkin's lymphoma

CD44 molecule is a cell surface glycoprotein involved in several cell-cell and cell-matrix interactions. It has been linked to the growth and spread of malignancies. The majority of non-Hodgkin's lymphomas (NHL) express CD44 reflecting the CD44 expression of the normal lymphocytic counterparts. Cell surface CD44 has been suggested to be involved in hematogenous distribution of NHL, and elevated levels of serum CD44 (s-CD44) have been detected in various malignant diseases. Circulating s-CD44 has been found to be functionally active according to several functional studies. In patients with NHL increased s-CD44 levels have been detected at the time of diagnosis and at progression of the disease and s-CD44 levels change in parallel with response to therapy. Moreover, a high s-CD44 level at diagnosis is associated with a high tumor burden, poor response to treatment and unfavorable outcome in NHL.

In vitro expression of soluble and cell surface-associated CD44 on endometrial cells from women with and without endometriosis

BACKGROUND

Endometriosis is one of the most common benign gynaecological diseases, and attachment of retrogradely shed viable endometrial cells is considered to be important in its development. CD44 is a multifunctional adhesion molecule that undergoes alternative splicing, giving rise to different isoforms.

METHODS

The expression of cell surface-associated CD44 std, v4, v5, v6 and v10 variants before and after cytokine treatment was investigated in endometrial cultures derived from 10 endometriosis patients and 22 women without the disease using immunocytochemistry. The immunoreactivity of soluble CD44 std, v5 and v6 variants was measured in culture medium using an enzyme immunoassay kit.

RESULTS

We report on the presence of soluble CD44 in endometrial culture supernatants. In particular, circulating CD44 standard form levels were significantly higher than levels of splice variants. We also found that both epithelial and stromal cells express surface-associated CD44 molecules in a distinct pattern and that this expression is not modulated by tumour necrosis factor (TNF)-alpha or/and interleukin 1 (IL-1) alpha/beta. Finally, cell surface-associated as well as soluble CD44 expression was similar in the two groups.

CONCLUSION

Our results indicate that endometrial cells can serve as a source of circulating CD44, but a direct role in the pathogenesis of endometriosis is rather improbable.

Prognostic Factors for Node-negative Breast Cancers: Results of a Study Program by the Japanese Breast Cancer Society

BACKGROUND: Prognostic factors for predicting the recurrence of node-negativebreast cancers have been controversial. The present study was performed to elucidate practically useful prognostic factors using formalin-fixed paraffin sections. METHODS: This was a case-controlled multi-institutional study that composed 40 patients with recurrent node-negative breast cancer and 80 patients with node-negative breast cancer but without recurrence after radical surgery. Tumors weresmaller than 3 cm in diameter and were treated surgically between January 1, 1985 and December 31, 1990. The recurrent and non-recurrent cases were matched with regard to their age, adjuvant chemotherapy and the year in which surgery was performed. Fourteen immunohistochemical factors and 8 histological factors of theprimary tumor were studied on formalin-fixed, paraffin-embedded sections by immunohistochemical and histochemical analyses. RESULTS: According to univariate analysis, factors such as progesterone receptor (PgR), MIB-1, CD44v6, CD44v9 and platelet-derived endothelial cell growth factor (PDECGF) were significantly different between the recurrent and non-recurrent groups (p &ly; 0.1; Wilcoxon-Mann-Whitney analysis). Chi-squared test showed significant differences in MIB-1, cdc2 and stromal plasminogen activator receptor (suPAR). Histologically, mitotic count was also significantly different between the two groups (p < 0.005). Multivariate analysis revealed that positivity for cdc2 (p=0.01), high mitotic count (p=0.04) and negativity for CD44v9 (p=0.02)were independent prognostic factors among variables selected by univariate analysis, and that positivity for MIB-1 (p=0.03) and cdc2 (p =0.01), and negativity for CD44v9 (p =0.03) were independent prognostic factors among the immunohistochemical markers examined. CONCLUSION: Our results indicated that positivity for MIB-1 and cdc2, high mitotic count and negativity for CD44v9 could serve as independent factors for predicting the recurrence of node-negative breast cancer.