216P - Gene expression profiling in estorogen receptor positive breast cancer with cancer stem-like cells

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Biomarkers
Breast Cancer
Presenter Yuko Tsunoda
Authors Y. Tsunoda1, M. Sakamoto2, E. Fukma2, T. Sawada3, A. Sasaki4, G. Yamamoto4, T. Tachikawa4
  • 1Breast Center, Kameda Medical Center, 296-8602 - Kamogawa City/JP
  • 2Breast Center, Kameda Medical Center, Kamogawa City/JP
  • 3Breast Surgery, Showa University School of Medicine, Tokyo/JP
  • 4Dental Pathology, Showa University School of Medicine, Tokyo/JP

Abstract

Objective

Breast cancer cells with CD44 + CD24-/low gene expression signature have been suggested to have stem cell-like tumor-initiating properties. The purpose of this study is to clarify the gene expression profiling of cells with CD44 + CD24-/low gene expression signature in the estrogen receptor (ER) positive tumors.

Methods

Laser-captured microdissection was used to select the isolation of cancer cells in 32 frozen tissues of breast cancer, and RNA extracted from these cells was examined by real-time RT-PCR to quantify CD44 and CD24 expressions. Human stem cell RT2 Profiler PCR Array was used for gene expression analysis in the groups of CD44 + CD24-/low and CD44 + CD24+ gene expression signature.

Results

Thirty-two tumors were divided into 2 groups. Group A was composed of the CD44 + CD24-/low type, in which the ratio of CD44/CD24 was >10.0. Group B was composed of the CD44 + CD24+ type, in which the ratio was >0.1 and ≦ 10.0. The number of tumors in group A and B were 4 and28, respectively. Regarding the correlation of CD44/CD24 status with tumor characteristics, the tumors of group A were significantly associated with axillary lymph node metastasis compared with those of group B (P = 0.009). There were no significant differences in tumor size, nuclear grade between the two groups. HER2 status in the tumors of group B was significantly higher than group A (P = 0.028). According to signaling pathways, the number of expression genes for the Notch pathway in group A was significantly greater than in group B (P = 0.028). Overexpressed genes for ALDH1 (P = 0.021) and SOX2 (P = 0.018) were noted in group A compared to group B.

Conclusion

This study suggests that the Notch pathway may be an important signaling pathway in luminal subtype with CD44 + CD24-/low gene expression signature. In addition, either ALDH1or SOX2 may be a candidate marker for cancer stem cells in the ER positive breast cancer.

Disclosure

All authors have declared no conflicts of interest.