SCD1 inhibition enhances the effector functions of CD8+ T cells via ACAT1-dependent reduction of esterified cholesterol.

We previously reported that the inhibition of stearoyl-CoA desaturase 1 (SCD1) enhances the antitumor function of CD8+ T cells indirectly via restoring production of DC recruiting chemokines by cancer cells and subsequent induction of antitumor CD8+ T cells. In this study, we investigated the molecular mechanism of direct enhancing effects of SCD1 inhibitors on CD8+ T cells. In vitro treatment of CD8+ T cells with SCD1 inhibitors enhanced IFN-γ production and cytotoxic activity of T cells along with decreased oleic acid and esterified cholesterol, which is generated by cholesterol esterase, acetyl-CoA acetyltransferase 1 (ACAT1), in CD8+ T cells. The addition of oleic acid or cholesteryl oleate reversed the enhanced functions of CD8+ T cells treated with SCD1 inhibitors. Systemic administration of SCD1 inhibitor to MCA205 tumor-bearing mice enhanced IFN-γ production of tumor-infiltrating CD8+ T cells, in which oleic acid and esterified cholesterol, but not cholesterol, were decreased. These results indicated that SCD1 suppressed effector functions of CD8+ T cells through the increased esterified cholesterol in an ACAT1-dependent manner, and SCD1 inhibition enhanced T cell activity directly through decreased esterified cholesterol. Finally, SCD1 inhibitors or ACAT1 inhibitors synergistically enhanced the antitumor effects of anti-PD-1 antibody therapy or CAR-T cell therapy in mouse tumor models. Therefore, the SCD1-ACAT1 axis is regulating effector functions of CD8+ T cells, and SCD1 inhibitors, and ACAT1 inhibitors are attractive drugs for cancer immunotherapy.

Safety and efficacy of microwave endometrial ablation for patients with previous uterine surgery: a pilot study.

MEA (microwave endometrial ablation) is a treatment that can control hypermenorrhea. With the increase in the number of caesarean sections and myomectomies, an increasing number of patients with MEA have undergone previous incision of the uterine myometrium. Uterine perforation is major complication. Here we compared the incidence of complications and recurrence between groups with or without previous uterine surgery. 35 patients who underwent MEA were enrolled in the study. We assessed the thickness of uterine myometrium by MRI and transvaginal ultrasonography (TV-US). 12 patients (34%) had previous uterine surgery; Among 12 patients with previous uterine surgery, 6 (50%) showed thinning of the myometrium. No patient showed any complications. There was no difference in recurrence rate between two groups (1/12 = 8% and 2/23 = 8%, respectively). MEA can be performed safely and effectively even for patients with previous uterine surgery.IMPACT STATEMENTWhat is already known on this subject? MEA (microwave endometrial ablation) is a treatment that can control hypermenorrhea.A few serious complications have been reported, including uterine perforation and intestinal injury. There have been no collective reports on women with a history of uterine surgery, and the decision to perform MEA and the detailed procedures have not been clarified.What do the results of this study add? No patient who received MEA showed any complication regardless of previous uterine surgery. There was no difference in recurrence rate of hypermenorrhea between groups with and without previous uterine surgery. MEA could be performed safely and effectively in patients with previous uterine surgery preoperative imaging and intraoperative ultrasoundsWhat are the implications of these findings for clinical practice and/or further research? Curently, with the increase in the number of caesarean sections and myomectomies, the increasing number of patients with MEA have undergone previous incision of the uterine myometrium and this causes thinning of the myometrium. MEA can be safely performed without losing any therapeutic effect, even in patients with a history of uterine surgery, by using MRI and TV-US as preoperative evaluations.