Expression of CD44+/CD24- Cells in Breast Cancer
XQ Lu, ZH Suo, CL Ma, KJ Xu, YS Liu, HX Li. Zhengzhou University School of Medicine, Zhengzhou, Henan, China; Rikshospitalet University Hospital, University of Oslo, Oslo, Norway
Background: The cancer stem cells have been found recently to associate with tumor's development, drug resistance, and recurrence and have also become potential targets for cancer treatment. Two lineages of stem-like cell, side-population and CD44+/CD24-/low cells, have been identified in breast cancer cells lines, but there is little research on tumor tissue.
Design: Sixty-four cases of breast cancer tissues with invasive ductal carcinoma were examined with immunohistochemical stains for expression of CD44+/CD24- cells. The correlation between the CD44+/CD24- expression and other conventional biomarkers including ER, PR, HER-2, PS2, Bcl-2, and nm23 were analyzed. The association of the distribution and number of CD44+/CD24- cells with clinicopathological factors like tumour size, lymph node status and metastasis were explored. Expression of CD44 and/or CD24 was defined as over 1% of tumor cells positive for CD44 and/or CD24 staining while 5% was used as the cutoff for other markers.
Results: CD44+/CD24- cells were randomly distributed in breast cancer tissues. The expression of CD44+/CD24- cells were identified in 43 of 64 (67.2%) cases of the invasive ductal breast cancer, significantly higher than that of CD44-/CD24- (p=0.001) or CD44-/CD24+ (p=0.007) cells but similar to that of CD44+/CD24+ cells. The expression of CD44+/CD24- cells in breast cancers was neither correlated to that of other biomarkers of breast cancer nor to the clinicopathological factors examined.
Conclusions: CD44+/CD24- cells are randomly distributed in breast cancer tissue and not peripherally concentrated as predicted. The expression of CD44+/CD24- is significantly higher than that of CD44-/CD24- or CD44-/CD24+ in invasive ductal breast cancer. Similar expression of CD44+/CD24- and CD44+-/CD24+ suggest the stem-like cells may be diversified in breast cancer. Expression of CD44+/CD24- was not associated with that of ER, PR, HER-2, PS2, Bcl-2, nm23 or with the clinical factors including patients' age, tumor size and lymph node metastasis.
Monday, March 9, 2009 1:00 PM
Poster Session II # 37, Monday Afternoon