Protein & Peptide Letters

Aloperine Induces Apoptosis by a Reactive Oxygen Species Activation Mechanism in Human Ovarian Cancer Cells

Background: Ovarian cancer is the most lethal gynecologic malignancy worldwide with poor prognosis owing to chemotherapy resistance and cancer relapse. Hence, there is an urgent need to develop novel anticancer agents against ovarian cancer. Objective: The aim of this research is to investigate the possible anticancer activity of aloperine, an active ingredient from a traditional Chinese medicine Sophora alopecuroides, and to explore the possible Reactive Oxygen Species (ROS)-related mechanism. Methods: Cell viability, cytotoxicity, apoptosis, ROS generation, and oxidant stress indicators were analyzed. Results: Our results demonstrated that aloperine significantly induced inhibition of cell viability, promoted cytotoxicity and mitochondrial-related apoptosis, and increased ROS generation in ovarian cancer cells. Furthermore, the antioxidant α-lipoic acid reversed apoptosis in aloperinetreated cells. In addition, we identified hydrogen peroxide as the main type of ROS, and the antioxidant catalase suppressed the apoptotic inducing effect of aloperine whereas hydrogen peroxide supplement exacerbated the effect of aloperine in ovarian cancer cells. Conclusion: Taken together, our results indicated that aloperine could exert anti-ovarian cancer cell activity through a reactive oxygen species activation mechanism and suggested aloperine as a potential agent against ovarian cancer.

Acetogenin Extracted from Annona muricata Prevented the Actions of EGF in PA-1 Ovarian Cancer Cells

Background:In individuals with ovarian cancer, an increase in the circulating level of the epidermal growth factor (EGF) is readily apparent. Ovarian cancer cells exhibit signaling pathway of the epidermal growth factor (EGFR) and respond to the EGF. Annona muricata (AM) has been shown to decrease ovarian cell proliferation however, role of AM in regulating EGF actions is not yet to be reported.Objective:In this study, we proposed that the fractionated compound acetogenin can inhibit the activation of EGFR-regulated signaling cascades such as MAPK7 / PI3K-Akt / mTOR / STAT upon EGF stimulation.Methods:Ethanolic extract was prepared for the whole AM plant and Thin Layer Chromatography (TLC) was performed to characterize the secondary metabolites and each fraction was assessed using kedde reagent for the presence of acetogenin. The effects of acetogenins were then tested on the survival of PA-1 ovarian cancer cells under basal and EGF stimulated conditions. To delineate the role of acetogenin in EGFR signaling cascades, the in silico docking studies were conducted.Results:The fraction of acetogenin decreased the viability of EGF induced PA-1 ovarian cancer cells that indicating the EGF inhibitory effects of acetogenin. The docking studies specifically illustrated that when the acetogenin binding with tyrosine kinase (TK) and regulatory unit (RU) which subsequently resulted in a reduction in EGF induced the survival of PA-1 ovarian cancer cells.Discussion:The vital regulatory role of acetogenin reported in this study indicate significant anticancer activities of acetogenin from AM. The in silico study of the acetogenin function predicted that it binds specifically to Asp837 (phosphor-acceptor site) of EGFR, essential for phosphorylation of substrates in the TK domain and RU which promote downstream signaling.Conclusion:Acetogenin isolated from AM effectively inhibited the survival of PA-1 ovarian cancer cells through impaired EGF signaling.

Role of TPD52 in Endometrial Cancer: Impact on EMT and the PI3K/AKT and ERK/MAPK Signaling

Introduction: Endometrial carcinoma (EC) incidence and mortality continue to rise, and reliable therapeutic targets remain scarce. We aimed to define the oncogenic role and mechanism of tumor protein D52 (TPD52) in EC, focusing on epithelial–mesenchymal transition (EMT) and the PI3K/AKT and ERK/MAPK signaling pathways. Methods: In this study, we assessed the expression levels of TPD52 in EC tissues and benign endometrial tissues using immunohistochemistry. To further investigate the role of TPD52, we performed experiments both in vitro and in vivo. We transfected siRNA and overexpression (OE) plasmids into Ishikawa and HEC-1-A cell lines to knock down (KD) or overexpress TPD52, respectively. We observed the effects of TPD52 knockdown on tumor growth and EMT through in vitro experiments. Results: TPD52 was significantly upregulated in EC tissues compared with those of benign endometrial tissues. Silencing TPD52 significantly inhibited cell proliferation, migration, and invasion, whereas TPD52 overexpression produced the opposite effects. TPD52 facilitates epithelial-mesenchymal transition (EMT). Moreover, TPD52 stimulates the PI3K/AKT and ERK/MAPK signaling pathways. Discussion: These data position TPD52 as a bona fide EC oncoprotein that drives EMT via dual PI3K/AKT–ERK/MAPK signaling. Limitations include the modest patient cohort and the lack of clinical–pathological correlation analyses. Conclusion: TPD52 promotes EC progression through EMT and PI3K/AKT and ERK/MAPK activation, offering a promising therapeutic target whose clinical utility warrants further investigation.