Affiliations: [a] Department of Molecular Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran | [b] Oncopathology Research Center, Iran University of Medical Sciences, Tehran, Iran | [c] Department of Pathology, Iran University of Medical Sciences, Tehran, Iran | [d] Department of Pathology, Milad Hospital, Tehran, Iran | [e] Department of Pathology, Tufts University School of Medicine, Boston, MA, USA
Correspondence:
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Corresponding author: Zahra Madjd, Oncopathology Research Center, Iran University of Medical Sciences (IUMS), Hemmat Street (Highway), Next to Milad Tower, Tehran 14496-14530, Iran. Tel.: +98 2186703212; Fax: +98 2188622608; E-mail: Zahra.madjd@yahoo.com.
Abstract: Backgroud:According to the cancer stem cell theory, tumors originate from a subset of cells known as cancer stem cells (CSCs) that are responsible for tumor initiation, resistance and relapse. CD44 is a cell adhesion molecule that can aid in the identification of CSCs in various malignancies. Objective:The purpose of the current study is to evaluate the expression level and clinical significance of CD44 in lung cancer samples. Methods:One hundred and ninety-five lung tumor samples including 74 (38%) squamous cell carcinomas (SCC), 61 (31%) adenocarcinomas (ADC), 23 (12%) large cell carcinoma (LCC) in non-small cell lung cancer (NSCLC) group and 37 (19%) small cell lung cancer (SCLC) samples were examined for the expression of CD44 using immunohistochemistry method. The correlation of CD44 expression with clinicopathological parameters as well as Ki-67 status was also assessed. Results:Univariate analysis demonstrated that CD44 expression was significantly higher in NSCLC compared to SCLC (P < 0.001). Among NSCLC, higher level of CD44 expression was found in SCC compared to ADC (P< 0.001) and LCC (P=0.046). Increased expression of CD44 was significantly correlated with higher grade tumors which correspond to poor prognosis in SCC (P=0.012) and the lower level of CD44 expression was more often found in well differentiated ADC tumors (P=0.03). In addition, high expression of CD44 was significantly associated with decreased level of proliferative marker Ki-67 (P=0.04). CONCLUSIONS:CD44 could be a valuable tool for the study of lung CSCs and provide a novel therapeutic target for treatment of the patients with lung cancer in combination with conventional therapy.
Keywords: Cancer stem cells, non-small cell lung cancer, small cell lung cancer, CD44, Ki-67
