1. 1. Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200031, China.
2. 2. Department of Obstetrics and Gynecology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
3. 3. Gongli Hospital Affiliated to the Second Military Medicical University in Pudong New Area of Shanghai City, Shanghai 200135, China.
* These authors contributed equally to this work and shared the first authorship.
Ovarian cancer is a highly malignant gynecologic tumor that seriously endangers women's health. We previously demonstrated that anisomycin significantly inhibited the activity of ovarian cancer stem cells (OCSCs) in vitro and in vivo. In the present study, anisomycin treatment of OCSCs significantly reduced ATP and T-GSH content; and increased pyruvate, LPO, and MDA. Anisomycin also significantly inhibited the proliferation of OCSCs in vitro, and its effect was similar to that of elesclomol and buthionine sulfoximine (BSO), suggesting that it has the potential to promote cuproptosis of OCSCs. Our subsequent cDNA microarray analysis results showed that anisomycin significantly reduced the transcriptional levels of genes that protect copper metabolism and cuproptosis, including the PDH complex, metallothionein, lipoid acid pathway, and FeS cluster proteins. Bioinformatics analysis revealed that four core factors (lipoic acid pathway FDX1, DLD, DLAT, PDH), and transcription factor YY1 were highly expressed in ovarian cancer tissues and were significantly correlated with an unfavorable prognosis. Further analysis depicted multiple YY1-recognized motif basic sites as existing in the promoters of the above four factors. In addition, the expression levels of YY1 in the tissue samples from ovarian cancer patients were significantly positively correlated with the expression levels of FDX1, DLD, DLAT, PDHB, and other genes. Finally, the analysis of the peripheral blood exosome database disclosed that the contents of the four key factors of YY1 and the lipoic acid pathway in the peripheral blood exosomes of patients with ovarian cancer were significantly elevated relative to those of normal healthy individuals. Therefore, our molecular biology experiments combined with bioinformatics analysis results suggest that the direct target of anisomycin-induced cuproptosis in ovarian cancer stem cells is probably a YY1 transcription factor. By inhibiting the expression and activity of YY1, anisomycin could not activate the transcriptional activity of the core genes of the lipoic acid pathway (i.e.,FDX1, DLD, DLAT, and PDHB), and induced the accumulation of cytotoxic substances, eventually leading to potential cuproptosis in ovarian cancer stem cells.
Keywords: Ovarian cancer stem cells, anisomycin, Yinyang 1(YY1), lipoic acid pathway, cuproptosis