Establishment and characterization of chemotherapy-enriched sphere-forming cells with stemness phenotypes as a new cell line (BAG) of gastric carcinoma.

Gastric cancer is a malignancy with a high mortality rate worldwide. Cancer stem cells (CSCs) are a small subpopulation of tumor cells that possess the tumor-initiating ability, self-renewal capacity, and high resistance to conventional therapies. Due to the diversity and complexity of human tumors, new cell lines are urgently needed to supply clinically and physiologically relevant cancer models. Here, we report establishing a novel cell line (BAG) with stemness properties. Chemotherapy-enriched sphere-forming cells with CSC properties isolated from a patient with GC were cultured in a serum-containing medium and passaged for up to 51 passages. The colony-forming ability and tumor-forming capacity of BAG cells were evaluated in vitro and in vivo. mRNA upregulation of stemness-related transcriptional factors using real-time PCR as well as expression of CSC markers using flow cytometry was investigated. Finally, STR profiling and chromosome studies were performed. BAG cells formed floating spheroid colonies in a serum-free medium. Subcutaneous injection of these cells generated xenograft tumors in nude mice. Pluripotency markers (SOX-2, OCT4, and Cripto-1) in them were upregulated compared with normal gastric cells. The majority of them expressed CSC markers of CD44, CD54, and EpCAM, and stemness marker of oct-4. STR profiling showed a unique DNA fingerprint. Karyotype also demonstrated multiple aneuploidies and chromosomal translocations. We suggested that the highly tumorigenic BAG cell line with stem cell-like phenotypes may provide a valuable in vitro tool to support new diagnostic, prognostic, and predictive biomarkers as well as the development of more effective treatment strategies.