Sex hormones, the anticancer immune response, and therapeutic opportunities

Sex disparities in hepatocellular carcinoma immunotherapy: hormonal and genetic influences on treatment efficacy

Hepatocellular carcinoma (HCC) is a highly aggressive liver cancer with a rising incidence globally. Immunotherapy, particularly immune checkpoint inhibitors (ICIs), has revolutionized HCC treatment, yet response rates remain variable. Sex-based disparities in immunotherapy efficacy have become increasingly recognized as important factors influencing treatment outcomes in HCC. This review examines the role of biological sex in HCC progression and immunotherapy responses. It discusses the epidemiology of sex differences in HCC incidence, prognosis, and therapeutic outcomes, highlighting the impact of sex hormones, such as estrogen and testosterone, on immune system function and tumor biology. Estrogen's protective effects, including enhanced T cell activation and improved immune surveillance, contribute to better treatment responses in females, while testosterone's immunosuppressive effects lead to poorer outcomes in males. The review also explores the influence of the tumor microenvironment, including immune cell composition and macrophage polarization, on treatment efficacy. Emerging evidence suggests that sex-specific factors, including hormonal status, should be considered in clinical trials and personalized treatment strategies. By addressing these disparities, tailored immunotherapeutic approaches could optimize efficacy and minimize toxicity in both male and female HCC patients, ultimately improving overall outcomes.

Mechanisms of Acetate in Alleviating SETDB1-Linked Neuroinflammation and Cognitive Impairment in a Mouse Model of OSA

Background

Microglia-mediated neuroinflammation is crucial for obstructive sleep apnea (OSA)-induced cognitive impairment. We aimed to investigate roles of acetate (ACE) and SET domain bifurcated histone lysine methyltransferase 1 (SETDB1) in neuroinflammation of OSA.

Methods

After C57BL/6J mice were exposed to OSA-associated intermittent hypoxia (IH) or normoxia for four weeks, the composition of the gut microbiota (GM) and the levels of serum short-chain fatty acids (SCFAs) were measured by 16S rRNA and GC-MS methods, respectively. To assess the effect of ACE on IH mice, glyceryl triacetate (GTA) was gavaged in IH-exposed mice and the cognitive function, microglial activation, and hippocampal neuronal death were examined. Moreover, ACE-treated BV2 microglia cells were also utilized for further mechanistic studies.

Results

IH disrupts the gut microbiome, reduces microbiota-SCFAs, and impairs cognitive function. Gavage with GTA significantly mitigated these cognitive deficits. Following IH exposure, we observed substantial increases in SETDB1 both in vivo and in vitro, along with elevated levels of histone H3 lysine 9 trimethylation (H3K9me3). Genetic or pharmacological inhibition of SETDB1 in microglia led to decreased induction of proinflammatory factors, as well as reduced reactive oxygen species (ROS) generation. Mechanistically, SETDB1 was found to upregulate the transcription factors p-signal transducer and activator of transcription 3 (p-STAT3) and p-NF-κB. In vitro, ACE supplementation effectively repressed high SETDB1 and H3K9me3 levels, thereby inhibiting microglial pro-inflammatory responses induced by IH. In vivo, ACE supplementation significantly reduced hippocampal levels of p-STAT3, p-NF-κB, and pro-inflammatory cytokines while also protecting neuronal integrity.

Conclusion

This study provides the first evidence that H3K9 methyltransferase SETDB1 promotes microglial pro-inflammatory response distinct from its previously shown role in macrophages. Our findings also identify ACE supplementation as a promising dietary intervention for OSA-related cognitive impairment with SETDB1 serving as both a mechanistic biomarker and potential therapeutic target.