PT  - JOURNAL ARTICLE
AU  - AOI OKAMOTO
AU  - YOHEI FUNAKOSHI
AU  - MASAHIRO OE
AU  - RYO TAKAI
AU  - HIROTAKA SUTO
AU  - YOSHIAKI NAGATANI
AU  - MEIKO NISHIMURA
AU  - YOSHINORI IMAMURA
AU  - TOMONARI KUNIHISA
AU  - NAOMI KIYOTA
AU  - KOJI MIKI
AU  - KOUICHI OHE
AU  - HIROKAZU TANINO
AU  - HIRONOBU MINAMI
TI  - Identification of Breast Cancer Stem Cells Using a Newly Developed Long-acting Fluorescence Probe, C5S-A, Targeting ALDH1A1
AID  - 10.21873/anticanres.15586
DP  - 2022 Mar 01
TA  - Anticancer Research
PG  - 1199--1205
VI  - 42
IP  - 3
4099  - http://ar.iiarjournals.org/content/42/3/1199.short
4100  - http://ar.iiarjournals.org/content/42/3/1199.full
SO  - Anticancer Res2022 Mar 01; 42
AB  - Background/Aim: Aldehyde dehydrogenase (ALDH) 1A1 is a well-known marker for cancer stem cells (CSCs), characterized by self-renewal capacity and multidrug resistance in breast cancer. We developed a near-infrared turn-on fluorescence probe for ALDH1A1, C5S-A, which is suitable for observing and analyzing viable cells. Here, we demonstrated the utility of C5S-A in CSC research using breast cancer cell lines. Materials and Methods: To evaluate concordance between C5S-A and conventional stem cell markers, breast cancer cells sorted for ALDEFLUOR-positive cells and for CD44+/CD24– cell populations were stained with C5S-A. Tumorigenicity of C5S-A-positive cells was examined by mammosphere formation assay and subcutaneous transplantation to immunodeficient mice. Additionally, to determine how long fluorescence from a single staining remained observable, we cultured breast cancer cells for 5 days after C5S-A staining. We then evaluated whether C5S-A-positive cells possessed resistance to cytotoxic drugs by chronological imaging. Results: C5S-A staining showed good concordance with conventional breast CSC markers, and good utility for research into CSC characteristics in breast cancer cell lines, including tumorigenesis. Additionally, C5S-A was observable for more than 3 days with a single staining. Using this property, we then confirmed that C5S-A-positive cells possessed resistance to cytotoxic drugs, which is one of the characteristics of CSCs. Conclusion: We showed that C5S-A is suitable for CSC research using breast cancer cell lines, and confirmed its utility in observing cells over time.