Phosphoproteomic Analysis of Gossypol-Induced Apoptosis in Ovarian Cancer Cell Line, HOC1a

Abstract

Ovarian cancer is a major cause for death of gynecological cancer patients. The efficacy of traditional surgery and chemotherapy is rather compromised and platinum-resistant cancer recurs. Finding new therapeutic targets is urgently needed to increase the survival rate and to improve life quality of patients with ovarian cancer. In the present work, phosphoproteomic analysis was carried out on untreated and gossypol-treated ovarian cancer cell line, HOC1a. We identified approximately 9750 phosphopeptides from 3030 phosphoproteins, which are involved in diverse cellular processes including cytoskeletal organization, RNA and nucleotide binding, and cell cycle regulation. Upon gossypol treatment, changes in phosphorylation of twenty-nine proteins including YAP1 and AKAP12 were characterized. Western blotting and qPCR analysis were used to determine expression levels of proteins in YAP1-related Hippo pathway showing that gossypol induced upregulation of LATS1, which phosphorylates YAP1 at Ser 61. Furthermore, our data showed that gossypol targets the actin cytoskeletal organization through mediating phosphorylation states of actin-binding proteins. Taken together, our data provide valuable information to understand effects of gossypol on protein phosphorylation and apoptosis of ovarian cancer cells.

Quantitative phosphoproteome analysis of cisplatin‐induced apoptosis in Jurkat T cells

“…To our knowledge, four other general phosphoproteomics studies have been performed using different apoptosis inducers and cell lines . Gossypol‐induced apoptosis was analyzed in an ovarian cancer cell line and more than 9000 phosphopeptides of 3000 phosphoproteins were identified.…”

“…Gossypol‐induced apoptosis was analyzed in an ovarian cancer cell line and more than 9000 phosphopeptides of 3000 phosphoproteins were identified. Thereof, 62 proteins with high scores were chosen and 33 phosphopeptides of 30 proteins changed comparing control versus apoptotic cells . In our phoshoproteome analysis, we identified 26 of these proteins with 23 consistent peptides.…”

“…A few quantitative phosphoproteomics studies of apoptotic cells have been performed . In these studies, different cell lines (bronchial epithelial, ovarian cancer and oral cancer) were studied using different apoptosis inducers (cadmium chloride, gossypol, γ‐bisabolene, and staurosporine) and proteomics approaches (TiO 2 ‐phosphopeptide enrichment/LC‐MS/label‐free quantification, protein array, and PROTOMAP).…”

The Ambivalent Function of YAP in Apoptosis and Cancer

“…Several compounds have been proven to regulate apoptosis via, or partly via, regulating Hippo-YAP signaling (Table 3). These compounds can be classified into five categories: (a) compounds that regulate upstream molecules of YAP or YAP per se to inhibit YAP accumulation, such as omega-3 polyunsaturated fatty acids (ω-3 PUFAs) [98], gossypol [116], resveratrol [40], 17-DMAG [117], amlexanox [71] and tubacin [117], norcantharidin [118,119], JQ1 [120], oligomeric proanthocyanidins (OPCs) [121]; (b) compounds that promote the phosphorylation of YAP and block YAP nuclear translocation, such as dobutamine [122], huaier [123], GCCSysm-4 (G4) [15], scutellarin [124] and hydrogen sulfide-releasing oleanolic acid (HS-OA) [125]; (c) compounds that inhibit the interaction of YAP and TEAD transcription factors, such as verteporfin [126,127,128] and CA3 [129], or inhibit the interaction of YAP and p63, such as nicotine [130]; (d) compounds that increase YAP accumulation, such as IBS003031 [131] and actinomycin D [132]; (e) compounds that regulate the YAP-p73 complex, such as α-TEA [133]. Many of these mentioned compounds are currently used in clinical trials (Table 3).…”

Effects of gossypol on apoptosis‑related gene expression in racially distinct triple‑negative breast cancer cells

“…The antiproliferative effect of GOSS is mediated through the induction of cellular apoptosis (31). Furthermore, the apoptotic effect of the compound was detected in different human cells, including multiple myeloma (32,33), synovial sarcoma (34) pharynx, tongue and salivary gland (35), prostate (36–38), colon (39), ovarian (40,41) gastric (42), leukemia (43,44) and pituitary (45), in addition to breast (31,46). In cancer therapy, the combination of multiple agents is key to overcoming the resistance mechanisms of the tumor (47), and GOSS has been found to induce an apoptotic effect in various human cancer cells in combination with low doses of taxanes (46), doxorubicin (34), dexamethasone (43) and valproic acid (36).…”