Figure 1.
Expression and distribution of ALDH1 protein in normal human tissues.
A. An FDA normal human organ tissue microarray was used to characterize the expression and distribution of ALDH1 in 24 tissues. B. Strongly positive ALDH1 cells were found in the areas in which epithelial stem/progenitor cells were putatively located in breast, colon and stomach.
Figure 2.
Expression and distribution of ALDH1 protein in human epithelial tumors.
Tissue microarrays were used to characterize the expression and distribution of ALDH1 in cancers (n = 353). A. Expression of ALDH1 in the corresponding normal tissues. B. ALDH1+ tumor-infiltrating cells were detected in the stroma. C. Expression of ALDH1 in epithelial tumors. Percentage of ALDH1+ tumor cells was summarized. D. High percentage of ALDH1+ cells was associated with poor clinical outcomes in serous ovarian cancer.
Figure 3.
ALDH1 enzymatic activity and expression in established epithelial tumor cell lines.
A. ALDH1 enzymatic activity was detected using the ALDEFLUOR assay. DEAB was used to inhibit the reaction of ALDH with the ALDEFLUOR reagent, providing a negative control. B. Summary of ALDH1 enzymatic activity in established breast (n = 15), ovarian (n = 18) and colon (n = 10) cancer cell lines. C. ALDH1 protein expression was detected by western blots. There was a positive correlation between ALDH1 protein expression and ALDH1 enzymatic activity. Full-length blots are presented in Supplemental Figure S3.
Figure 4.
ALDH1 enzymatic activity in primary epithelial ovarian cancer cells.
A. ALDH1 enzymatic activity in cells isolated from one ovarian cancer specimen. Dead cells were eliminated using magnetic beads and a MidiMACS separator. For immunophenotyping of ALDHbr ascites cells, APC-CD45 or APC-CD326 was used for counterstaining. DEAB was used to inhibit the reaction of ALDH with the ALDEFLUOR reagent, providing a negative control. B. Summary of the percentages of ALDHbr in each cell population from 16 late-stage ovarian cancer patients.
Figure 5.
ALDHbr tumor cells exhibit cancer stem cell properties.
A. ALDHbr cell populations (Blue) generated significantly higher numbers of mammospheres compared to the ALDHlow population (Yellow). B. Tumorigenicity of the ALDHbr and ALDHlow cells were examined in vitro using colony formation assays. C. Tumorigenicity of the ALDHbr and ALDHlow cells were examined in vivo. D. Histology of the ALDHbr and ALDHlow BT-474 tumors was examined by HE staining. E. Proliferation of the ALDHbr and ALDHlow BT-474 tumors was examined by Ki-67 immunostaining.
Figure 6.
ALDHbr tumor cells are resistant to the chemotherapeutic drug platinum.
A. ALDHbr cells were remarkably expanded in platinum resistant cell lines (A2780/CP70, A2780/C200 and A2780/C30) compared to their parental platinum sensitive line (A2780/WT). B. In vitro platinum treatment significantly increased the ALDHbr cell population in ovarian and breast cancer cell lines after three days. C. ALDHbr cells were resistant to platinum treatment. ALDHbr and ALDHlow cells were isolated by FACS sorting. D. ALDHbr tumor cell population was resistant to chemotherapy in vivo. The q7d×4 i.p. treatment schedule was used for the experimental therapy. Tumors were collected and disassociated by enzyme digestion. Percentage of the ALDHbr population was analyzed by ALDEFLUOR assay.