Traditional chemotherapy is being considered due to hindrances caused by systemic toxicity. Currently, the administration of multiple chemotherapeutic drugs with different biochemical/molecular targets, known as combination chemotherapy, has attained numerous benefits like efficacy enhancement and amelioration of adverse effects that has been broadly applied to various cancer types. Additionally, seeking natural‐based alternatives with less toxicity has become more important. Experimental evidence suggests that herbal extracts such as Solanum nigrum and Claviceps purpurea and isolated herbal compounds (e.g., curcumin, resveratrol, and matairesinol) combined with antitumoral drugs have the potential to attenuate resistance against cancer therapy and to exert chemoprotective actions. Plant products are not free of risks: Herb adverse effects, including herb–drug interactions, should be carefully considered. Linked Articles This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc
Ovulation is the strongest risk factor for ovarian high-grade serous carcinoma (HGSC) that largely originates from the fallopian tube fimbriae and always carries loss-of-function mutations of TP53 in both early and late lesions. Mature ovarian follicle contains high level of reactive oxygen species (ROS). When released from ovulation, follicular fluid (FF) bathes the fimbriae and may lead to DNA double-strand break (DSB) and neoplastic transformation. In this study, we examined the mutagenic and tumorigenic activities of human pre-ovulatory FFs. A subset (6/11) of FFs was found with high levels of ROS whereas the antioxidant capacities were indifferent. These ROS(high) FFs induced intracellular ROS and DSBs in the secretory cell population of fimbriae epithelium. When p53 and Rb were turned down, the FF-exposed secretory cells overcame apoptosis and expanded the population carrying ROS and DSB. The cancer initiation and promotion effects of FF were further recapitulated in Trp53 (-/-) mice. When introduced into the mammary fat pad, ROS(high) but not ROS(low) FFs induced early-onset B-cell lymphoma. Cotreatment with physiological concentration of melatonin, a potent antioxidant, ameliorated the mutagenic and tumorigenic effect of ROS(high) FF in vitro and in vivo. The study revealed ROS and mitogens in mature ovarian follicles could initiate the transformation of fimbria epithelium in the context of p53 loss and melatonin is a potent preventive agent.
Background The fallopian tube fimbria is regarded as the main tissue of origin and incessant ovulation as the main risk factor of ovarian high-grade serous carcinoma. Previously, we discovered the tumorigenesis activity of human ovulatory follicular fluid (FF) upon injection to the mammary fat pad of Trp53-null mice. We also found a mutagenesis activity of FF-ROS and a apoptosis-rescuing activity of Hb from retrograde menstruation. However, neither of them can explain the tumorigenesis activities of FF. Methods From two cohorts of ovulatory FF retrieved from IVF patients, the main growth factor responsible for the transformation of human fimbrial epithelial cells was identified. Mechanism of activation, ways of signal transduction of the growth factor, as well as the cellular and genetic phenotypes of the malignant transformation was characterized. Findings In this study, we showed that insulin-like growth factor (IGF)-axis proteins, including IGFBP-bound IGF2 as well as the IGFBP-lytic enzyme PAPP-A, are abundantly present in FF. Upon engaging with glycosaminoglycans on the membrane of fimbrial epithelial cells, PAPP-A cleaves IGFBPs and releases IGF2 to bind with IGF-1R. Through the IGF-1R/AKT/mTOR and IGF-1R/AKT/NANOG pathways, FF-IGF leads to stemness and survival, and in the case of TP53/Rb or TP53/CCNE1 loss, to clonal expansion and malignant transformation of fimbrial epithelial cells. By depleting each IGF axis component from FF, we proved that IGF2, IGFBP2/6, and PAPP-A are all essential and confer the majority of the transformation and regeneration activities. Interpretation This study revealed that the FF–IGF axis functions to regenerate tissue damage after ovulation and promote the transformation of fimbrial epithelial cells that have been initiated by p53- and Rb-pathway disruptions. Fund The study was supported by grants of the Ministry of Science and Technology, Taiwan (MOST 106-2314-B-303-001-MY2; MOST 105-2314-B-303-017-MY2; MOST 107-2314-B-303-013-MY3), and Buddhist Tzu Chi General Hospital, Taiwan (TCMMP104-04-01).
Fallopian tube fimbrial epithelium is considered to be the major site of origin of ovarian high-grade serous carcinoma, with p53 loss being the earliest and universal change. We previously reported that reactive oxygen species (
To search for cellular genes up-regulated by vaccinia virus (VV) infection, differential displayreverse transcription-polymerase chain reaction (ddRT-PCR) assays were used to examine the expression of mRNAs from mock-infected and VV-infected HeLa cells. Two mitochondrial genes for proteins that are part of the electron transport chain that generates ATP, ND4 and CO II, were up-regulated after VV infection. Up-regulation of ND4 level by VV infection was confirmed by Western blotting analysis. Up-regulation of ND4 was reduced by the MAPK inhibitor, apigenin, which has been demonstrated elsewhere to inhibit VV replication. The induction of ND4 expression occurred after viral DNA replication since ara C, an inhibitor of poxviral DNA replication, could block this induction. ATP production was increased in the host cells after VV infection. Moreover, 4.5 μM oligomycin, an inhibitor of ATP production, reduced the ATP level 13 hr after virus infection to that of mock-infected cells and inhibited viral protein expression and virus production, suggesting that increased ATP production is required for efficient VV production. Our results further suggest that induction of ND4 expression is through a Bcl-2 independent pathway.
Enterovirus type 71 (EV71) 2A protease exhibited strong transcriptional activity in yeast cells. The transcriptional activity of 2A protease was independent of its protease activity. EV71 2A protease retained its transcriptional activity after truncation of 40 amino acids at the N-terminus but lost this activity after truncation of 60 amino acids at the N-terminus or deletion of 20 amino acids at the C-terminus. Thus, the acidic domain at the C-terminus of this protein is essential for its transcriptional activity. Indeed, deletion of amino acids from 146 to 149 (EAME) in this acidic domain lost the transcriptional activity of EV71 2A protein though still retained its protease activity. EV71 2A protease was detected both in the cytoplasm and nucleus using confocal microscopy analysis. Coxsackie virus B3 2A protease also exhibited transcriptional activity in yeast cells. As expected, an acidic domain in the C-terminus of Coxsackie virus B3 2A protease was also identified. Truncation of this acidic domain resulted in the loss of transcriptional activity. Interestingly, this acidic region of poliovirus 2A protease is critical for viral RNA replication. The transcriptional activity of the EV71 or Coxsackie virus B3 2A protease should play a role in viral replication and/or pathogenesis.
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Background: High-grade serous carcinoma (HGSC) is mainly derived from the stepwise accumulation of driver mutations in the fallopian tube epithelium (FTE), and it subsequently metastasizes to the ovary and peritoneum that develops into a clinically evident ovarian carcinoma. The developmental process involves cell proliferation/clonal expansion, cell migration, anoikis resistance, anchorage-independent growth (AIG), peritoneum attachment, and cell invasion. Previously, we discovered FTE could be transformed by follicular fluid (FF) released from ovulation, the most crucial risk factor of ovarian cancer, and IGF axis proteins in FF confers stemness activation and clonal expansion via IGF-1R/AKT pathway. However, whether other phenotypes in advanced cancer development are involved is unknown. Methods: A panel of FTE and ovarian HGSC cell lines with different severity of transformation were treated with FF with or without IGF-1R and AKT inhibitors and analyzed for the transformation phenotypes in vitro, ex vivo, and in vivo. Results: FF largely promotes (by order of magnitude) cell migration, AIG, cell invasion, peritoneum attachment, anoikis resistance, and cell proliferation. Most of these activities worked in the full panel of cell lines. The AIG activity largely depends on IGF-1R/AKT phosphorylation, and the proliferation activity depends on an AKT phosphorylation not mediated by IGF-1R. In contrast, both AKT- and non-AKT-mediated signals are responsible for the other transformation activities. Conclusions: Our data demonstrate an extensive transformation activity of FF in the full journey of carcinogenesis, and endorsed ovulation-inhibition for the prevention and AKT-inhibition for the treatment of ovarian HGSC.
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