Taking the rap: multiple effects of blocking mammalian target of rapamycin

Reactive Oxygen Species as a Link between Antioxidant Pathways and Autophagy

Reactive oxygen species (ROS) are highly reactive molecules that can oxidize proteins, lipids, and DNA. Under physiological conditions, ROS are mainly generated in the mitochondria during aerobic metabolism. Under pathological conditions, excessive ROS disrupt cellular homeostasis. High levels of ROS result in severe oxidative damage to the cellular machinery. However, a low/mild level of ROS could serve as a signal to trigger cell survival mechanisms. To prevent and cope with oxidative damage to biomolecules, cells have developed various antioxidant and detoxifying mechanisms. Meanwhile, ROS can initiate autophagy, a process of self-clearance, which helps to reduce oxidative damage by engulfing and degrading oxidized substance. This review summarizes the interactions among ROS, autophagy, and antioxidant pathways. The effects of natural phytochemicals on autophagy induction, antioxidation, and dual-function are also discussed.

Neoadjuvant chemoradiotherapy followed by liver transplantation is a promising treatment for patients with unresectable hilar cholangiocarcinoma: A case report

Hilar cholangiocarcinoma is a highly malignant tumor and is currently treated by surgical resection or liver transplantation; however, these treatments result in poor patient prognosis accompanied with high recurrence and low patient mortality rates. Neoadjuvant therapy with liver transplantation is a novel treatment that exhibits promising clinical application, with a reported 5-year survival rate of 82%. However, transplantation centers conducting research into this treatment are limited due to its length and complexity. In the current study, the effects of brachytherapy and chemoradiotherapy followed by orthotopic liver transplantation (OLT) were investigated in a patient with unresectable hilar cholangiocarcinoma. Following treatment, the liver function of the patient normalized and physical status significantly improved. Furthermore, tomographic evaluation demonstrated no sign of recurrence 8 months later following continued adjunct chemotherapy. Therefore, neoadjuvant therapy followed by OLT may be an effective novel therapeutic strategy to treat patients with unresectable hilar cholangiocarcinoma.