Immunohistochemical Expression of CD 133 and CD 24 for Detection of Cancer Stem Cells in Urinary Bladder Carcinoma (Pilot Study)

Abstract

Bladder cancer accounts for approximately 7% of all cancers. The vast majority of bladder cancers (90%) are transitional carcinoma (Kumar et al., 2013). It is the sixth most common cancer in the United States after lung cancer, prostate cancer, breast cancer, colon cancer, and lymphoma. The global burden of bladder cancer is predicted to increase significantly in the future as a result of population aging ,together with the progression of the tobacco abuse and increasing exposure to occupational carcinogens in developing countries (Ploeg et al ., 2009). The incidence of human bladder cancer has increased extensively through the last decades. Despite several attempts, it is still difficult to predict tumour progression, optimal therapy, and finally clinical outcome (Thogersen et al., 2001). A clinically detectable tumor contains a heterogeneous population of cells, which originated from the clonal growth of the progeny of a single cell. Yet, it has been difficult to identify cancer stem cells, that is, the cells within a tumor that have the capacity to initiate and sustain the tumor (Ploeg et al., 2009)

Studies have shown that CD 133 and CD 24 serve as prognostic and/or as therapeutic targets in malignant tumors . Moreover, these markers may be useful in subgrouping of cancer patients with significantly differing outcome. The aim of this work is to detect cancer stem cells and evaluate the possible role of stem cells markers (CD 133 and CD 24 ) in urinary bladder carcinoma , followed by correlation of the results with clinicopathologic parameters to evaluate their prognostic value. To attain the aim, the our study comprised a total number of 60 cases of urinary bladder carcinoma were examined for CD 133 and CD 24 immunohistochemical staining. . The cases were obtained from the files of the Pathology Lab. of Maady Military Hospital and Ain-Shams University Specialized Hospital. All cases were diagnosed during the period 2012 to 2013. Clinical data as regards age and sex were collected from the hospital charts. In the carcinoma group, patients' age ranged between 43-87 years with a mean age 57 (±7.43) years. Forty eight (48 ) tumours occurred in males and 12 tumours occurred in females with a male: female ratio 4:1. Histopathologic and immunohistochemical study of all cases were done. For light microscopic examination, haematoxylin and eosin sections were revised to evaluate the pathologic parameters of the cases. Immunohistochemical staining was performed on formalin fixed, paraffin –embedded tissues using the avidin biotin complex immunoperoxidase technique to evaluate CD 133 and CD 24 expression in tissue samples. In our study, the bladder carcinoma included (50 cases ) of transitional cell carcinoma, (8 cases) of Squamous cell carcinoma and (2) cases of adenocarcinoma. Transitional cell carcinoma were graded according to WHO classification 2004 (Eble et al., 2004) as low grade {n= 18 (36 %), two cases were grade I and 16 cases were grade II } and high grade (N= 32 (64 % ), all of them were grade III. Squamous cell carcinoma (n=8) cases included one case (12.5 %) of well differentiation tumor, three cases (37.5%) were moderately differentiated tumors and four cases (50 %) were poorly differentiated tumors. Adenocarcinoma cases (n= 2) , all were of moderate differentiation.