Cancer Stem Cells and Sonic Hedgehog Signaling in Head and Neck Cancer: Potential Targets for Overcoming Chemoradiation Resistance

Cancer stem cells (CSC) are a small and distinct population of cancer cells that possess self-renewal and differentiation ability and are relatively resistant to treatment including chemotherapy and radiotherapy. Sonic hedgehog (SHH) and related signaling molecules are critical to embryonic development and regulate both proliferation and differentiation of various types of stem cells, including CSC. This article provides a brief overview of the SHH signaling pathway, summarizes the correlation between SHH signaling and treatment resistance of cancer cells and discusses the recent advances in targeting this signaling cascade to overcome treatment resistance. We proposed that CSC and their related the SHH signaling pathway might be potential targets for overcoming chemoradiation resistance of head and neck cancer cells. This has been under investigation by our comprehensive team treating head and neck cancers.