Involvement of NFkB signaling in CSC accumulation of head and neck carcinoma cell lines resistant to chemotherapy

Abstract

NFkB is a transcription factor whose signaling is involved in the inflammation and immunological response. NFkB and its target-genes are accumulated in several solid and hematological cancers, including head and neck carcinoma. Over activation of NFkB leads to cellular survival, activation of proliferation, inhibition of apoptosis and activation of invasion and metastasis. Nuclear accumulation, which activates NFkB, is associated to resistance to cisplatin in head and neck tumors. Resistance to antitumor drugs is an important issue to therapeutic efficacy and deregulation of several signaling, such as NFkB pathway, control the tumor resistance. Recently, chemo resistance has been associated with a small population of tumor cells with stem-like phenotype. Cancer stem cells are frequently in a quiescent state that protect them against most of cancer treatments, which are effective only to proliferating cells. Cancer stem cells also have self-renewal and differentiation capacity, which promote recidive and metastasis after treatment. Therefore, the characterization of signaling involved in the accumulation of cancer stem cells after treatment may contribute to the development of new therapeutic strategies to overcome chemo resistance. (AU)