Although great progress has been made recently in targeted
and
immune-based therapies, additional treatments are needed for most
melanoma patients due to acquired chemoresistance, recurrence, or
metastasis. Elevated autophagy is required for the pathogenesis of
melanoma to attenuate metabolic stress, protecting cancer cells from
chemotherapeutics or radiation. Thus, intervention with autophagy
is a promising strategy for melanoma treatment. Here, we examined
a novel antimelanoma natural compound named kuwanon H (KuH), which
significantly inhibited melanoma cell growth in
vitro/vivo. Mechanistically, KuH induced
cytotoxic endoplasmic reticulum (ER) stress, which inhibited cell
viability and induced apoptosis. Meanwhile, KuH-induced ER stress
mediated autophagysome formation through the ATF4-DDIT3-TRIB3-AKT-MTOR
axis. Importantly, KuH impaired autophagy flux, which contributed
to the anticancer effects of KuH. Finally, our results showed that
KuH enhanced the sensitivity of melanoma cells to cisplatin, both in
vitro and in vivo,
by impairing autophagy degradation of reactive oxygen species and
damaged mitochondria. Our findings indicate that KuH is a promising
candidate anticancer natural product for melanoma therapy.