CDP-choline accumulation in breast and colorectal cancer cells treated with a GSK-3-targeting inhibitor

Browning of Mammary Fat Suppresses Pubertal Mammary Gland Development of Mice via Elevation of Serum Phosphatidylcholine and Inhibition of PI3K/Akt Pathway

Mammary fat plays a profound role in the postnatal development of mammary glands. However, the specific types (white, brown, or beige) of adipocytes in mammary fat and their potential regulatory effects on modulating mammary gland development remain poorly understood. This study aimed to investigate the role of the browning of mammary fat on pubertal mammary gland development and explore the underlying mechanisms. Thus, the mammary gland development and the serum lipid profile were evaluated in mice treated with CL316243, a β3-adrenoceptor agonist, to induce mammary fat browning. In addition, the proliferation of HC11 cells co-cultured with brown adipocytes or treated with the altered serum lipid metabolite was determined. Our results showed that the browning of mammary fat by injection of CL316243 suppressed the pubertal development of mice mammary glands, accompanied by the significant elevation of serum dioleoylphosphocholine (DOPC). In addition, the proliferation of HC11 was repressed when co-cultured with brown adipocytes or treated with DOPC. Furthermore, DOPC suppressed the activation of the PI3K/Akt pathway, while the DOPC-inhibited HC11 proliferation was reversed by SC79, an Akt activator, suggesting the involvement of the PI3K/Akt pathway in the DOPC-inhibited proliferation of HC11. Together, the browning of mammary fat suppressed the development of the pubertal mammary gland, which was associated with the elevated serum DOPC and the inhibition of the PI3K/Akt pathway.

UHPLC-HRMS-based serum untargeted lipidomics: Phosphatidylcholines and sphingomyelins are the main disturbed lipid markers to distinguish colorectal advanced adenoma from cancer

Colorectal advanced adenoma (CAA) is a key precancerous lesion of colorectal cancer (CRC), and early diagnosis can lessen CRC morbidity and mortality. Although abnormal lipid metabolism is associated with the development of CRC, there are no studies on the biomarkers and mechanism of lipid metabolism linked to CAA carcinogenesis. Hence, we performed a lipidomics study of serum samples from 46 CAA, and 50 CRC patients by the ultra high-performance liquid chromatography tandem high resolution mass spectrometry (UHPLC-HRMS) in both electrospray ionization (ESI) modes. Differential lipids were selected by univariate and multivariate statistics analysis, and their diagnostic performance was evaluated using a receiver operating characteristic curve (ROC) analysis. Combining P < 0.05 and variable importance in projection (VIP) > 1, 59 differential lipids were obtained totally. Ten of them showed good discriminant ability for CAA and CRC (AUC > 0.900). Especially, the lipid panel consisting of PC 44:5, PC 35:6e, and SM d40:3 showed the highest selection frequency and outperformed (AUC = 0.952). Additionally, phosphatidylcholine (PC) and sphingomyelin (SM) were the main differential and high-performance lipids. In short, this is the first study to explore the biomarkers and mechanism for CAA-CRC sequence with large-scale serum lipidomics. The findings should provide valuable reference and new clues for the development of diagnostic and therapeutic strategies of CRC.

Regulation of GSK3β/Nrf2 signaling pathway modulated erastin-induced ferroptosis in breast cancer

Ferroptosis is a newly discovered form of regulated cell death and characterized by an iron-dependent accumulation of lethal lipid reactive oxygen species (ROS), ferroptosis may exhibit a novel spectrum of clinical activity for cancer therapy. However, the significance of ferroptosis in the context of carcinoma biology is still emerging. Glycogen synthase kinase-3β (GSK-3β) has been found to be a fundamental element in weaking antioxidant cell defense by adjusting the nuclear factor erythroid 2-related factor 2 (Nrf2). In our study, decreased expression of GSK-3β was observed in the cancer tissues of breast cancer patients, results of immunohistochemistry indicated that Nrf2 was highly expressed in low-GSK-3β-expressed breast cancer tissues. The contributions of aberrant expression of GSK-3β and Nrf2 to the erastin-induced ferroptosis in breast cancer were further assessed, silence of GSK-3β blocked erastin-induced ferroptosis with less production of ROS and malondialdehyde (MDA) via upregulation of GPX4 and downregulation of arachidonate 15-lipoxygenase (Alox15), overexpression of GSK-3β enhanced erastin-triggered ferroptosis with elevated ROS and MDA. Enhanced erastin-induced ferroptosis by overexpression of GSK-3β was blocked by activating Nrf2. We further confirmed that overexpression of GSK-3β strengthened erastin-induced tumor growth inhibition in breast cancer xenograft models in vivo. In summary, our findings conclude that modulation the balance between GSK-3β/Nrf2 is a promising therapeutic approach and probably will be important targets to enhance the effect of erastin-induced ferroptosis in breast cancer.