CD44v6 expression is related to progression in renal epithelial tumours

Prognostic value of CD44 expression in renal cell carcinoma: a systematic review and meta-analysis

CD44 is a marker of cancer stem-like cells in renal cell carcinoma (RCC). However, the prognostic value of CD44 in RCC remains controversial. This study evaluated the correlation of CD44 expression with the clinicopathological features of RCC through a meta-analysis. We systematically searched PubMed, ISI Web of Science and Embase for relevant studies until February 2015. We collected and analysed data on clinical stage, Fuhrman grade, microvascular invasion, recurrence, five-year overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS). Twenty studies involving 1672 patients satisfied the inclusion criteria. Results showed that high CD44 expression in RCC was a poor prognostic marker for five-year OS (RR = 0.69, 95% CI 0.60–0.78) in a fixed-effects model and for five-year DSS (RR = 0.46, 95% CI 0.27–0.80) and five-year DFS (RR = 0.63, 95% CI 0.43–0.93) in a random-effects model. CD44 expression also correlated with Furhman grade (RR = 0.61, 95% CI 0.48–0.77), tumour recurrence (RR = 7.42, 95% CI 3.74–14.70) and MVI (Microvascular invasion) (RR = 3.63, 95% CI 1.97–6.71). This meta-analysis suggests that CD44 is a prognostic marker in RCC. High CD44 expression correlates with high Fuhrman grade, recurrence, MVI and poor prognosis.

CD44 attenuates metastatic invasion during breast cancer progression

Metastatic invasion is the primary cause of breast cancer mortality, and adhesion receptors, such as CD44, are believed to be critical in this process. Historically, primary breast tumor epithelium has been investigated in isolation from other tissue components, leading to the common interpretation that CD44 and its primary ligand, hyaluronan, promote invasion. Here, we provide in vivo evidence showing CD44 antagonism to breast cancer metastasis. In a mouse model of spontaneously metastasizing breast cancer (MMTV-PyV mT), we found that loss of CD44 promotes metastasis to the lung. Localization studies, in combination with a novel hyaluronan synthase-GFP transgenic mouse, show a restricted pattern of expression for CD44 and hyaluronan. Whereas CD44 is expressed in tumor epithelium, hyaluronan synthase expression is restricted to stromal-associated cells. This distinct CD44 and hyaluronan pattern of distribution suggests a role for epithelial-stromal interaction in CD44 function. To define the relevance of this spatial regulation, we developed an in vitro invasion assay to emulate invasion into the extracellular matrix. Invasion of CD44-positive tumor cells was inhibited in hyaluronan-containing matrices, whereas blocking CD44-hyaluronan association increased invasion. Collectively, these data show that during breast cancer progression, hyaluronan-CD44 dynamics occurring through epithelial-stromal interactions are protective against metastasis.

[Prognosis factors in pT3 renal carcinoma]

OBJECTIVES

To identify independent predictors of progression and global survival in patients affected by pT3 renal cell carcinoma. To make risk groups by risk factors.

MATERIAL AND METHODS

We evaluated 117 patients with pT3 renal cell carcinoma. 88 was M0 and 29 M1. Most frequent clinical feature: asintomatic patients. 80 males (69%) and 37 females (31%). Mean age 59 (24-82). Median follow up 34 months (mean 44 +/- 39 months).

RESULTS

Pathological stage (TNM 1997) was pT3a in 52 patients (43.6%), pT3b 63 patients (53.6%) and pT3c 2 patients.

HISTOLOGY

clear cell carcinoma 106 patients (90.6%), papillary 5 patients (4.3%) an dchromophobe 4 patients (3.4%). Nuclear grading according Fuhrman's classification: G1 13 patients, G2 45 patients, G3 32 and G4 12 patients. Size > 4 cm (p = 0.005/p = 0.0019), grade 3-4 (p = 0.006/p = 0.0007), N+ (p = 0.034/p = 0.009) and M+ (p = 0.035/p = 0.042) were independent prognosis factors for progression and global survival of the pT3 renal cell carcinoma. Patients M0 with 0 or 1 risk factor have better global survival tanh patients M0 with 3 or 4 risk factors and patients M1.

CONCLUSIONS

Size, grade, N+ and M+ were independent prognosis factors for progression and global survival of the pT3 renal cell carcinoma. Tera are no differencies in global survival between patients M0 with 2 or 3 risk factors and patients M1.

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.

[Clinical features, diagnosis, and prognosis of renal carcinoma]

Significant conceptual changes have taken place in renal tumoral diseases over the last few years. As a result of the authors' broad institutional experience, this overall revision describes the most up-to-date clinical and diagnostic aspects of this condition. Emphasis is made on molecular staging and two variables that guide the prognosis of the disease, a decisive feature to establish treatment and to contribute to change current survival rates.

Expression of CD44 protein in renal cell carcinomas: association with p53 expression

CD44 is an adhesion molecule involved in cell-to-cell and cell-to-matrix interactions. Recent evidence indicates a role of CD44 in tumor growth and metastatic potential of tumor cells. Moreover, it is widely known that the p53 tumor suppressor gene controls cell proliferation and loss of its normal function may lead to carcinogenesis. To investigate the role of these biomarkers in renal cancer, we analyzed the immunohistochemical distribution of CD44's expression on formalin fixed paraffin embedded tissue from 67 renal cell carcinomas and correlated with clinicopathologic parameters as well as with p53 suppressor gene expression. The monoclonal antibodies CD44 and p53 were applied to the tissues using the streptavidin biotin peroxidase method after microwave antigen retrieval. For CD44 and p53 more than 10% membranous and 5% nuclear staining, respectively, were estimated as positive. CD44's membranous immunoreactivity was detected in 24/67 tumors (35%) and mostly in carcinomas of clear/granular cell type. Nine tumors expressed nuclear immunoexpression of p53 protein (13.4%). Statistically significant correlation was noted between CD44 expression and nuclear grade (P < 0.001), tumor stage (P < 0.001), vascular invasion (P < 0.05) and p53 expression (P < 0.01). These results suggest that CD44s and p53 are markers of tumor progression in renal cell cancer.

CD44-dependent lymphoma cell dissemination: a cell surface CD44 variant, rather than standard CD44, supports in vitro lymphoma cell rolling on hyaluronic acid substrate and its in vivo accumulation in the peripheral lymph nodes

Cell motility is an essential element of tumor dissemination, allowing organ infiltration by cancer cells. Using mouse LB lymphoma cells transfected with standard CD44 (CD44s) cDNA (LB-TRs cells) or with the alternatively spliced CD44 variant CD44v4-v10 (CD44v) cDNA (LB-TRv cells), we explored their CD44-dependent cell migration. LB-TRv cells, but not LB-TRs or parental LB cells, bound soluble hyaluronic acid (HA) and other glycosaminoglycans (GAGs), and exclusively formed, under physiological shear force, rolling attachments on HA substrate. Furthermore, LB-TRv cells, but not LB-TRs cells or their parental LB cells, displayed accelerated local tumor formation and enhanced accumulation in the peripheral lymph nodes after s.c. inoculation. The aggressive metastatic behavior of i.v.-injected LB-TRV cells, when compared with that of other LB-transfectants, is attributed to more efficient migration to the lymph nodes, rather than to local growth in the lymph node. Injection of anti-CD44 monoclonal antibody or of the enzyme hyaluronidase also prevented tumor growth in lymph nodes of BALB/c mice inoculated with LB-TRv cells. The enhanced in vitro rolling and enhanced in vivo local tumor growth and lymph node invasion disappeared in LB cells transfected with CD44v cDNA bearing a point mutation at the HA binding site, located at the distal end of the molecule constant region. These findings show that the interaction of cell surface CD44v with HA promotes cell migration both in vitro and in vivo, and they contribute to our understanding of the mechanism of cell trafficking, including tumor spread.

CD44s and CD44v6 expression in localized T1-T2 conventional renal cell carcinomas

To assess the prognostic value of CD44s and CD44v6 tumour expression for patients with T1-T2 conventional renal cell carcinomas, a retrospective immunohistochemical analysis of 95 patients was undertaken. These patients had undergone a radical nephrectomy, performed in three institutions in France between 1987 and 1993. The mean age of the patients was 62.9+/-10.2 years (range from 37 to 85 years) with 66.3% males. At the time of surgery, 84 patients had a T1 and 11 a T2 renal tumour. Fuhrman nuclear grading showed 44 (46.3%) tumours of grade 1, 39 (41.1%) of grade 2, and 12 (12.6%) of grade 3. The mean follow-up period was 58.1+/-36.1 months. At the end of follow-up, eight patients (8.4%) had metastatic disease and no local recurrence was seen. Immunohistochemistry showed that 26 tumours (27.4%) expressed CD44s, but none expressed CD44v6. Statistical analysis showed that CD44s expression was correlated with tumour size (p=0.006) and Fuhrman grading (p<10(-4)). Among the various parameters tested for the multivariate analysis, CD44s expression correlated only with disease-free survival (p=0.04). It is concluded that CD44s expression, but not CD44v6, is of potential prognostic interest in patients with localized T1-T2 conventional renal cell carcinomas.

Expression of CD44 adhesion molecules in nonpapillary renal cell carcinoma and normal kidneys

OBJECTIVES

To analyze the relationship between the alterations in the expression of the CD44 gene in nonpapillary renal cell carcinoma (RCC) and several clinicopathologic factors.

METHODS

The expression of the CD44 gene in 10 human RCC cell lines, 60 nonpapillary RCC tumor samples, and 15 normal kidney samples was investigated by reverse-transcription polymerase chain reaction (RT-PCR) using a set of primers capable of amplifying all CD44 variant isoforms. The results were analyzed with respect to several clinicopathologic factors.

RESULTS

Nine of the 10 human RCC cell lines predominantly expressed the standard CD44 isoform (CD44s); CD44v10 was the major isoform in the 10th RCC cell line. The 15 normal kidney samples revealed the identical CD44 gene expression pattern; that is, CD44s, CD44v8-10, and CD44v10 were detectable in normal kidneys, and among them, CD44s was expressed most dominantly. In the 60 nonpapillary RCC samples, CD44s, CD44v8-10, and CD44v10 were the major isoforms in 46 (77%), 11 (18%), and 3 (5%) cases, respectively. Furthermore, the incidence of the predominant expression of CD44v8-10 in high-stage RCC was significantly higher than that in low-stage RCC. CD44s was more frequently expressed as a major isoform in clear cell RCC than in other histologic types of RCC.

CONCLUSIONS

The results of this study show that the alternative splicing pattern of CD44 gene in RCC is different in each histologic type of RCC and suggest that CD44v8-10 upregulation in the progression of nonpapillary RCC is important.