Effect of human survivin-2B-specific cytotoxic CD8+ T lymphocytes on CD44+/- HSC-2 and HSC-3 oral cancer cells.

Despite advancements in the treatment of oral cancer, cancer survival rates remain low, highlighting the need for new therapeutic strategies targeting cancer stem-like cells. Cancer stem-like cells are a small population of cancer cells within tumors that drive recurrence and metastasis. They are often resistant to conventional treatments. Immunotherapy has shown promise against cancer stem-like cells, particularly with the use of cytotoxic T lymphocytes targeting specific markers. Survivin, an apoptosis protein inhibitor, is overexpressed in several malignancies, including oral cancer, and is associated with tumor recurrence and reduced survival. Survivin-2B-specific cytotoxic T lymphocytes were produced and evaluated for their ability to target CD44+ (cancer stem-like cells) and CD44- cells (non-cancer stem-like cells), respectively, from oral cancer cell lines (HSC-2 and HSC-3, respectively). Quantitative polymerase chain reaction (qPCR) analysis confirmed similar survivin-2B expression in both cell types. Cytotoxic T lymphocyte assays revealed the effective lysis of both cancer stem-like cells and CD44- cell populations, supporting the potential of survivin-2B-specific cytotoxic T lymphocytes to overcome cancer stem-like cell-associated resistance. These findings suggest that survivin-2B peptide vaccines are effective in preventing cancer relapse by targeting cancer stem-like cells, with future directions aimed at developing multipeptide "cocktail" vaccines to reduce the risk of immune evasion.