Frequent expression of the high molecular, 673-bp CD44v3,v8-10 variant in colorectal adenomas and carcinomas

Abstract

Abstract. CD44 is a transmembrane glycoprotein involved in the interaction between cells and the extracellular matrix. A large variety of alternatively spliced CD44 variants are expressed by different tumors with possible implication for tumor progression, formation of metastasis and survival. In colon carcinomas, previous reports described higher molecular bands of CD44 transcripts in neoplastic colonic tissue, although a complete analysis of multiple combinations of CD44v transcripts were not performed. We therefore analyzed the pattern of CD44 standard and variant (v2-v10) transcripts in colorectal adenomas and carcinomas by exon-specific RT-PCR amplification and sought CD44v transcripts specific for colonic neoplasias. Our data indicate that CD44 standard transcripts, including the epithelial form (C-v8,v9,v10-C) corresponding to a 720 bp transcript, were detected in 2/38 (5.2%) samples of normal mucosa, 20/20 (100%) adenomas and in 21/33 (63%) colorectal carcinomas. High molecular CD44v3,v8-10 (673 bp) transcripts were found in 2/33 (6%) samples from normal mucosa, 19/20 (95%) from adenomas and in 29/31 from colorectal carcinomas (93%). Similar CD44v3,v8-10 transcripts were detected in five from seven colorectal liver metastases, while normal liver did not contain high molecular CD44v3 variants. The same CD44v3,v8-10 (673 bp) variant was detected in HT-29 human colon carcinoma cells. Direct sequencing of the CD44v3 (673 bp) transcript in samples from colorectal carcinomas and HT-29 cells confirmed the assumed CD44v (-C-v3-v8-v9-v10-C-) cDNA sequence. Analysis of other CD44 variant transcripts (v4-v10) using exon specific primers were less frequently associated with colorectal neoplasias. These data report for the first time frequent expression of neoplasia-associated CD44v3,v8-10 variants in colorectal adenomas and carcinomas supporting the role of increased CD44 variant expression as an early event in colorectal carcinogenesis. The described CD44v3,v8-10 (673 bp) variant might be relevant for diagnosis and treatment of colorectal cancer. IntroductionThe colonic adenoma-carcinoma sequence has been characterized by various changes in the expression of oncogenes, tumor suppressor genes, growth factors and DNA repair mechanisms (1-3). Adhesion molecules interacting with extracellular matrix molecules such as CD44 mediate interactions of the tumor cell with the microenvironment leading to tumor invasion and progression (4). The transmembrane glycoprotein CD44 and its splice variants are implicated in cell adhesion, proliferation, migration, tumor cell invasion and metastatic disease (5,6).CD44 is a transmembrane glycoprotein encoded by 20 exons, at least 10 of which are variably expressed due to alternative splicing ( Fig. 1) (7). CD44 functions as a receptor for hyaluronic acid and elements of the extracellular matrix including laminin and fibronectin (8,9). Furthermore, CD44 expression is involved in lymphocyte activation, hematopoiesis and stem cell differentiation (10). Alterations in the CD44 variant exp...

Stress-Response Protein RBM3 Attenuates the Stem-like Properties of Prostate Cancer Cells by Interfering with CD44 Variant Splicing

“…CD44 is commonly expressed as a wide variety of isoforms that mainly arise from alternatively spliced variants, which is particularly important for CD44 functions in tumor cells (42). Among the various isoforms, CD44v8-v10 has been reported to be the predominant form that is expressed in a variety of cancers (43)(44)(45). Indeed, overexpression of this isoform enhances bladder cancer progression potentially by decreasing the interaction of CD44 with hyaluronan (46).…”

CD44v8-10 as a potential theranostic biomarker for targeting disseminated cancer cells in advanced gastric cancer

“…While the standard isoform of CD44 (CD44s) is known to predominate in hematopoietic cells and normal epithelial cell subsets, many variant isoforms (CD44v) with the extended extracellular stalk region are more prevalent in epithelial carcinomas 7 . It was reported that the CD44v3,8-10 isoform was involved in the metastasis of breast cancer 8 and colorectal adenomas 9 , and CD44v3 and CD44v6 for colorectal cancer 10 . Furthermore, CD44v6 and CD44v9 interact with CD95, the death receptor, interfering with death receptor signalling and inhibiting apoptosis 11 .…”

Development of a sandwich enzyme-linked immunosorbent assay for the detection of CD44v3 using exon v3- and v6-specific monoclonal antibody pairs

“…Despite the need to noninvasively detect CD44v3, currently there are no reports describing direct measurement of CD44v3 serum levels in cancer patients using a sandwich ELISA. Most studies have quantified CD44v3 expression levels between normal and tumor tissues using reverse transcription PCR, western blotting, or immunohistochemical staining (Kuniyasu et al, 2002;Reategui et al, 2006;Kopp et al, 2009). In this study, we have developed a sandwich ELISA that may potentially be used clinically to specifically detect soluble CD44v3 in cancer patient sera.…”