Co‑expression of and is associated with poor prognosis, and is required for the survival of ALDH1‑positive pancreatic cancer stem cells.

Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter, which has been identified as a prognostic marker in several types of cancer, including pancreatic cancer. However, to the best of our knowledge, the association between expression and cancer stem cell (CSC) markers, such as aldehyde dehydrogenase 1 (ALDH1), in pancreatic ductal adenocarcinoma (PDAC), and the role of in PDAC CSCs remains unclear. In the present study, a genomic dataset of primary pancreatic cancer (The Cancer Genome Atlas, Pan-Cancer Atlas) was downloaded and analyzed. Kaplan-Meier analysis and multivariate Cox regression analysis were performed to evaluate the overall survival, disease-specific survival (DSS), disease-free interval (DFI) and progression-free interval (PFI). Subsequently, small interfering RNA (siRNA) knockdown (KD) was induced in the PANC-1 and MIA-PaCa-2 PDAC cell lines, and in sorted high ALDH1 activity (ALDH1) cells, after which, cell viability, tumor sphere formation, cell death and caspase-3 activity were examined. The results revealed that patients with high expression of ( ) at tumor stage I had a poor prognosis compared with patients with low expression of ( ) in terms of DSS, DFI and PFI. In addition, patients with high expression of and ( ) exhibited poorer clinical outcomes than patients with high expression of and low expression of ( ), low expression of and high expression of ( ) and . siRNA KD in ALDH1 cells isolated from PANC-1 and MIA-PaCa-2 cell lines resulted in suppression of tumorsphere formation, and enhancement of cell death and caspase-3 activity. These results suggested that was involved in cell survival via the suppression of caspase-3-dependent apoptosis, and contributed to cancer progression and poor clinical outcomes in PDAC. In conclusion, may be used as a prognostic marker and novel therapeutic target of ALDH1-positive pancreatic CSCs.