Inhibition of UBA5 Expression and Induction of Autophagy in Breast Cancer Cells by Usenamine A

Abstract

Breast cancer is now the most common type of cancer worldwide, surpassing lung cancer. This issue is further worsened by the lack of effective therapies for the disease. Recent reports indicate that the inhibition of ubiquitin-like modifier-activating enzyme 5 (UBA5) can impede tumor development. However, there have been few reports regarding UBA5-inhibiting compounds. This work studied usenamine A, a natural product from the lichen Usnea longissimi that exhibits UBA5-inhibitory effects. Bioinformatics analysis was performed using public databases, and the anti-proliferative ability of usenamine A in breast cancer cells was examined through MTS and clone formation assays. Flow cytometry and western blot analysis were also conducted to examine and analyze cell cycle arrest and apoptosis. In addition, LC3B-RFP and UBA5 expression plasmids were used for the analysis of usenamine A-induced autophagy. According to the bioinformatics analysis results, UBA5 was upregulated in breast cancer. According to in vitro studies, usenamine A displayed prominent anti-proliferative activity and resulted in G2/M phase arrest in MDA-MB-231 cells. Moreover, usenamine A induced autophagy and endoplasmic reticulum stress in MDA-MB-231 cells. In conclusion, the findings support the potential of usenamine A as an agent that can attenuate the development and progression of breast cancer.

Discovery of Anticancer Activity of Amentoflavone on Esophageal Squamous Cell Carcinoma: Bioinformatics, Structure-Based Virtual Screening, and Biological Evaluation

“…Transwell Permeable Supports, Polycarbonate Membranes (Corning Inc., USA) were used for transwell assay as previously described [ 19 ]. After treatment with amentoflavone (0, 50, 100, 150 μM) for 48 h, the cells were resuspended in serum-free medium (1 × 10 6 cells/ml).…”

The UFM1 conjugation system in mammalian development

“…24,71 More importantly, some key components of UFMylation participate in the regulation of autophagy. 72 No evidence has shown the involvement of UFMylation in the ubiquitin-proteasome system. These findings together indicate that UFMylation may mediate the proteome homeostasis through the autophagy pathway.…”

UFMylation System: An Emerging Player in Tumorigenesis

“…Meanwhile, the E1 activating enzyme UBA5 was found to be upregulated in breast cancer and associated with poor prognosis. Its inhibitor, usenamine A, a natural product from Usnea longissimi, could induce apoptosis, autophagy and ER stress in breast cancer cells, decelerating the pathogenesis of breast cancer [ 68 ]. Additionally, the LncRNA of UFC1 promoted the proliferation and migration of breast cancer via the miR-34a/CXCL10 axis [ 37 ].…”

“…Thus, the present findings on the mechanistic links between UFMylation and tumorigenesis represent only a starting point, and the potential and underlying mechanisms of UFMylation in the context of tumorigenesis need further studies and investigations; furthermore, whether UFM1 modification is related to other non-cancer diseases remains to be explored. In addition, although a few compounds were reported to inhibit the activity of the E1 enzyme UBA5, thus impeding the development of tumorigenesis [ 68 , 82 , 84 ], progress has stagnated due to the lack of suitable assay reagents necessary for their introduction. Therefore, the discovery of novel compounds or valid targets is an area of great interest that would paved the way for future cancer-related therapeutic interventions.…”