Abstract Various types of chemotherapeutic agents are widely used to treat a variety of human neoplasms. Nonetheless, its clinical use is hampered because of severe adverse side effects such as alopecia, neutropenia, pain, cachexia, conception impairment etc. Chemotherapy-induced alopecia (CIA) is one of the fundamental unsolved problems of clinical oncology that often encountered in cancer treatment. CIA has been reported to be caused by skin inflammation through oxidative stress, DNA damage, and inflammatory responses. However, the best remedy for CIA is still not established. In a new strategy, we show that WK0202 compound as a strong NQO1 substrate that modulates the intracellular NAD+ levels by NAD(P)H quinone oxidoreductase 1 (NQO1) enzymatic action and plays important role in hair regrowth response to single (cyclophosphamide-CYP) or combined (taxol, adriamycin and cyclophosphamide-TAC) cancer therapy. Particularly, we demonstrated that cellular NAD+ levels as well as SIRT1 activity and its expression was decreased in skin with hair follicles after CYP and TAC treatment, and PARP-1 hyperactivation was associated with CIA through increased nuclear factor (NF)-κB p65 and p53 acetylation in wild type, NQO1-/- and K14-/- C57BL/6 mice. However, an increase in NAD+ levels by WK0202 completely restored SIRT1 activity and its expression, and subsequently deacetylated NF-κB p65 and p53 in wild type, however not in NQO1-/- and K14-/- mice thereby attenuating CIA. Therefore, modulation of NAD+ levels by NQO1 may be a novel therapeutic approach to prevent chemotherapy-associated hair loss, including CIA. Citation Format: Dipendra Khadka, Gi-Su Oh, Hyung-Jin Kim, SeungHoon Lee, Su-bin Lee, Subham Sharma, Seon Young Kim, Tae Hwan Kwak, Sei-Hoon Yang, Hyuk Sim, Hong-Seob So. Role of NAD+ level by NQO1 enzymatic action in regulation of hair regrowth that prevents chemotherapy-induced alopecia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2717.