CD44 and its v6 spliced variant in lung tumors

Abstract

The results of the current study show that CD44v6 is localized differently in fetal and adult lung, suggesting a difference in function. In the fetal lung, it may modulate growth factors important in morphogenesis and maturation. In the adult nonneoplastic lung, CD44v6 is associated with stem cells, namely basal cells and type 2 pneumocytes, and may act to anchor these cells to the matrix and be important in migration during repair or neoplasia. In addition, CD44v6 expression is maintained throughout tumorigenesis in squamous cell carcinoma and bronchioloalveolar cell carcinoma, suggesting a histogenetic relationship between the stem cells and the respective tumors. Conversely, most neuroendocrine tumors and the cells of the dispersive neuroendocrine system do not express CD44v6, implying a separate histogenetic lineage in these tumors.

Expression and prognostic relevance of CD44v6 in stage I non-small cell lung carcinoma

“…Similarly, high level of CD44v6 expression only existed in 9 out of 60 cases (15%) in our study. Moreover, CD44v6 staining of type 2 pneumocytes was also seen in normal adult lungs (Fasano et al 1997); thus it is rational to predict that bronchioloalveolar carcinomas might show CD44v6 expression which mirrors that of normal type 2 pneumocytes. However, our data displayed the high expression rate of CD44v6 in bronchioloalveolar carcinomas was only 15.4% (6 out of 39 cases).…”

“…High expression of CD44v6 was more frequently seen in squamous cell carcinoma than in any other histological types of NSCLC, which was consistent with the previous studies (Fasano et al 1997;Hirata et al 1998). Squamous cell carcinoma of the lung is thought to arise from metaplastic squamous epithelium that progresses through dysplasia, carcinoma in situ, and Wnally into invasive carcinoma, and the squamous metaplasia is believed to develop through the replacement of the ciliated epithelium by bronchial basal cells that show strong positivity for CD44v6 protein expression.…”

CD44 expression is a feature of prostatic small cell Carcinoma and Distinguishes it from its Mimickers

“…Expression of CD44s and CD44v6 were similarly rare in SCNCs of the lung (2/14 tumors) [33]. Among the different subtypes of lung cancer, SCNCs express CD44 least frequently [34][35][36][37][38][39][40]. Our results are consistent with the published data and suggest that the consistently strong and diffuse staining of CD44 in almost all tumor cells is a unique feature for prostatic SCNCs.…”

Expression of epidermal growth factor receptor and CD44 splicing variants sharing exons 6 and 9 on gastric and esophageal carcinomas: a two-color flow-cytometric analysis

“…Recently, similar CD44v6 expression has been detected in lung carcinomas of various histological types and degrees of dierentiation, by the immunohistochemical method (Fasano et al 1997). In addition, we identi®ed signi®cant down-regulation of CD44v6 expression in irradiated SCC at doses of 36±40 Gy.…”