Activation of the YY1-UGT2B7 Axis Promotes Mammary Estrogen Homeostasis Dysregulation and Exacerbates Breast Tumor Metastasis.

Metastasis is the most common pathway of cancer death. The lack of effective predictors of breast cancer metastasis is a pressing issue in clinical practice. Therefore, exploring the mechanism of breast cancer metastasis to uncover reliable predictors is very important for the clinical treatment of breast cancer patients. In this study, tandem mass tag quantitative proteomics technology was used to detect protein content in primary breast tumor tissue samples from patients with metastatic and nonmetastatic breast cancer at diagnosis. We found that the high expression of yin-yang 1(YY1) is strongly associated with poor prognosis in high-grade breast cancer. YY1 expression was detected in both clinical tumor tissue samples and tumor tissue samples from mammary-specific polyomavirus middle T antigen overexpression mouse model mice. We demonstrated that upregulation of YY1 expression was closely associated with breast cancer metastasis and that high YY1 expression could promote the migratory invasive ability of breast cancer cells. Mechanistically, YY1 directly binds to the UGT2B7 mRNA initiation sequence ATTCAT, thereby transcriptionally regulating the inhibition of UGT2B7 expression. UGT2B7 can regulate the development of breast cancer by regulating estrogen homeostasis in the breast, and the abnormal accumulation of estrogen, especially 4-OHE2, promotes the migration and invasion of breast cancer cells, ultimately causing the development of breast cancer metastasis. In conclusion, YY1 can regulate the UGT2B7-estrogen metabolic axis and induce disturbances in estrogen metabolism in breast tumors, ultimately leading to breast cancer metastasis. Disturbances in estrogen metabolism in the breast tissue may be an important risk factor for breast tumor progression and metastasis SIGNIFICANCE STATEMENT: In this study, we propose for the first time a regulatory relationship between YY1 and the UGT2B7/estrogen metabolism axis and explore the molecular mechanism. Our study shows that the YY1/UGT2B7/estrogen axis plays an important role in the development and metastasis of breast cancer. This study further elucidates the potential mechanisms of YY1-mediated breast cancer metastasis and the possibility and promise of YY1 as a predictor of cancer metastasis.

Eupatilin alleviates inflammatory response after subarachnoid hemorrhage by inhibition of TLR4/MyD88/NF-κB axis.

Early brain injury (EBI) is associated with the adverse prognosis of subarachnoid hemorrhage (SAH) patients. The key bioactive component of the Chinese herbal medicine Artemisia asiatica Nakai (Asteraceae) is eupatilin. Recent research reports that eupatilin suppresses inflammatory responses induced by intracranial hemorrhage. This work is performed to validate whether eupatilin can attenuate EBI and deciphers its mechanism. A SAH rat model was established by intravascular perforation in vivo. At 6 h after SAH in rats, 10 mg/kg eupatilin was injected into the rats via the caudal vein. A Sham group was set as the control. In vitro, BV2 microglia was treated with 10 µM Oxyhemoglobin (OxyHb) for 24 h, followed by 50 µM eupatilin treatment for 24 h. The SAH grade, brain water content, neurological score, and blood-brain barrier (BBB) permeability of the rats were measured 24 h later. The content of proinflammatory factors was detected via enzyme-linked immunosorbent assay. Western blot analysis was conducted to analyze the expression levels of TLR4/MyD88/NF-κB pathway-associated proteins. In vivo, eupatilin administration alleviated neurological injury, and decreased brain edema and BBB injury after SAH in rats. Eupatilin markedly reduced the levels of interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α), and suppressed the expression levels of MyD88, TLR4, and p-NF-κB p65 in the SAH rats' cerebral tissues. Eupatilin treatment also reduced the levels of IL-1ß, IL-6, and TNF-α, and repressed the expression levels of MyD88, TLR4, and p-NF-κB p65 in OxyHb-induced BV2 microglia. Additionally, pyrrolidine dithiocarbamate or resatorvid enhanced the suppressive effects of eupatilin on OxyHb-induced inflammatory responses in BV2 microglia. Eupatilin ameliorates SAH-induced EBI via modulating the TLR4/MyD88/NF-κB pathway in rat model.