Expression of Putative Stem Cell Markers CD133 and Oct-4 in Papillary Renal Cell Carcinoma and Its Prognostic Significance.
Kyungeun Kim, Jae Y Ro, Yong Mee Cho. Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
Background: Papillary renal cell carcinoma (PRCC) is the second most common malignant tumor of the kidney. Except for tumor stage and histologic type, its prognostic parameters remain controversial. Recently, cancer stem cells (CSCs) have been a focus of growing attention because of their implication in therapeutic resistance and poor prognosis. CD133 is a cell surface marker being widely used to identify CSCs in various organs. Oct-4 is a transcription factor serving as a key regulator of stemness of stem cells. However, their expression pattern and its prognostic significance have not been evaluated in PRCC.
Design: The expressions of CD133 and Oct-4 were examined in a tissue microarray constructed from 124 cases of PRCC by immunohistochemistry and correlated with clinicopathologic prognostic factors.
Results: CD133 was expressed at the apicolateral membrane of tumor cells in 45 cases (36.9%). CD133-expressing PRCCs showed favorable prognostic features such as type 1, small tumor size, kidney-confined disease, low tumor stage, no distant organ metastasis, and prolonged disease-specific survival rate compared to CD133-negative PRCCs. Oct-4 showed nuclear staining and was expressed in 26 cases (21.1%) of PRCCs. In contrast to the CD133 expression, high expression of Oct-4 (cut-off value of 12.5%) was associated with frequent lymphovascular invasion and shorter disease-specific survival. In multivariate analysis, tumor stage, histologic type, and high Oct-4 expression were independent prognostic factors for disease-specific survival. CD133 expression was an important prognostic marker in univariate analysis, however, was not independent prognostic factor in multivariate analysis.
Conclusions: These results indicate that besides being stem cell markers, CD133 and Oct-4 expression can be used as prognostic markers in PRCC with CD133 expression as a favorable prognostic marker and especially Oct-4 over-expression as a poor prognostic marker.
Category: Genitourinary (including renal tumors)
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 81, Wednesday Morning