Serum CD44 levels in patients with non-small cell lung cancer and their relationship with clinicopathological features

Overexpression of CD44 is associated with the occurrence and migration of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a potentially fatal disease and the incidence is increasing annually. In order to diagnose and treat NSCLC effectively, greater understanding of its molecular mechanism is required. In the present study, 36 NSCLC tissues and 10 normal tissues were selected. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to analyze the CD44 mRNA expression level in NSCLC tissue and DNA sequencing was performed to further verify the CD44 expression level. Differentially expressed genes between tumor tissues and controls were determined by DNA sequencing and the Gene_act_net between CD44 and its associated genes was constructed. Gene Ontology (GO) term enrichment analysis of the differentially expressed genes was performed by the Biological Networks Gene Ontology tool. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed based on the Expression Analysis Systematic Explorer test applied in the Database for Annotation, Visualization and Integrated Discovery. RT-qPCR results showed that CD34 was overexpressed in 21 of the 36 NSCLC tissues (58.3%). The Gene_act_net indicated that there were 20 differentially expressed genes with 17 upregulated and 3 downregulated. Among them, CD44, MET, ERBB2, EGFR, AKT1, IQGAP1 and STAT3 were associated with the occurrence and migration of NSCLC. In KEGG pathway analysis, extracellular matrix-receptor interaction and hematopoietic cell lineage pathways were the most affected by overexpressed CD44; and thus may be important in the development and migration of NSCLC. In conclusion, CD44 was overexpressed in NSCLC and the overexpression was associated with the occurrence of NSCLC and migration of NSCLC cells.

MMP-2, TIMP-2 and CD44v6 Expression in Non-small-cell Lung Carcinomas

Introduction: Factors that emerge as crucial participants in tumour invasion and metastases are matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinase (TIMP) inhibitors and cellular adhesion molecules (CD44 and similar molecules). They play important roles in tumour invasion and metastasis in non-small-cell lung carcinomas (NSCLCs). Materials and Methods: The study was performed using the data of 33 patients. MMP-2 from the metalloproteinase family, TIMP-2 from the metalloproteinase inhibitor family and the adhesion molecule CD44v6 expression were investigated immunohistochemically to search their role in the metastasis and the clinical outcome of the patients with NSCLCs. Results: Twenty-three tumours (70%) were squamous cell carcinoma (SCC), 9 (27%) were adenocarcinoma (AC), and 1 (3%) was large cell carcinoma (LCC). MMP-2 and TIMP-2 were expressed in high rates in NSCLC but CD44v6 expression was about 50%. Lymphatic invasion was less frequent in TIMP-2-positive patients and this difference was statistically significant (P = 0.005). There was a statistically significant difference between SCCs and ACs with respect to CD44v6 tumoral expression (P = 0.004). Also, there was a negative correlation between lymphatic invasion and the extent of CD44v6; lymphatic invasion was significantly less in CD44v6-positive cases (P = 0.013). Conclusion: We found that TIMP-2 and CD44v6 can decrease the lymphatic invasion in NSCLCs. Also there was observed histiotype-related pattern of CD44v6 variant expression in SCCs. Key words: Immunohistochemistry, Metastasis, Pulmonary neoplasms

Variant expression of CD44 in preneoplastic lesions of the lung

BACKGROUND

Specific CD44 isoforms are cell surface adhesion molecules and have been shown to be associated with tumor progression and metastasis. In lung carcinoma, CD44 expression has been reported to be a feature of nonsmall cell lung carcinoma (NSCLC) but not small cell lung carcinoma. A specific variant, CD44v6, was shown to be expressed only in a subset of NSCLC, namely the squamous cell and bronchoalveolar carcinomas, suggesting that CD44 may play a role in lung carcinoma differentiation.

METHODS

To determine whether differential CD44 expression is an early event in the pathogenesis of lung carcinoma, the authors investigated the pattern of expression of the standard (CD44s) and variant (CD44v6) isoforms by immunohistochemistry in normal lung, nonneoplastic specimens, and bronchial biopsies of preneoplastic lesions.

RESULTS

In normal bronchial epithelium and all nonneoplastic cases, CD44s expression was limited to the basement membrane and adjacent lower strata of the epithelium, whereas CD44v6 was expressed within the basement membrane only. However, aberrant expression of both CD44s and CD44v6 was observed in all preneoplastic lesions examined. In cases of dysplasia, squamous metaplasia, goblet cell hyperplasia, and basal cell hyperplasia, all epithelial strata showed immunoreactivity for both isoforms, in contrast to normal epithelium, in which immunoreactivity was noted to be restricted to the basal layer cells. In contrast, CD44s and CD44v6 expression was completely absent in nearly all cases of adenomatosis.

CONCLUSIONS

Altered CD44s and/or CD44v6 expression appears to be a feature of all preneoplastic lesions in the lung, the precise nature of which varies according to histologic tumor type. Therefore, the authors conclude that CD44s and CD44v6 may lend themselves to be markers of preneoplastic changes in the lung.

Expression of CD44 variants in lung cancer and its relationship to hyaluronan binding

We examined the expression of CD44 variant forms and their binding to hyaluronan (HA) in lung cancer cell lines. There was no relationship between the level of expression of CD44 variants and HA binding in different lung cancer cell lines. The expression of CD44v6 and CD44E in some cell lines was not always associated with HA binding. There was no relationship between the tissue pathological type and CD44 expression or HA binding. Deglycosylation by neuraminidase induced CD44-HA binding in human lung cancer cell lines. Our findings suggest that the HA binding ability of CD44, which is negatively regulated by glycosylation, might be a more important factor in tumorigenesis or metastasis than the expression of CD44 variant forms.