CD44v9 and CD98hc is the marker of cancer stem cells in HNSCC

Received: June 03, 2018; Accepted: June 22, 2018; Published: June 25, 2018 Cancer stem cells are the most important targets for cancer therapy. Prince et al. report CD44 is the cancer stem cell marker in HNSCC [1]. But various isoforms can be found in CD44, so it is unclear that which variant is the most important. One of characteristic of cancer stem cell is the radio-resistance. Various HNSCC cell lines are irradiated and we established radio-resistant cell line. After irradiation, the expression of CD44v9 increased in all HNSCC cell lines [2]. At present, the importance of CD44v9 is being studies. CD44v9 is expressed in cancer stem cells and functions to enhance the oxidative stress avoidance mechanism that causes resistance to treatment. This indicates that oxidative stress is important for the survival and proliferation of tumor cells, such stress has dual effects of inducing not only differentiation but also cell death when a certain threshold value is exceeded. In addition, in cell membranes, CD44v9 binds to xCT, which is a light chain subunit system xc-, a transporter that takes cysteine into cells.