DHA2, a synthesized derivative of bisbibenzyl, exerts antitumor activity against ovarian cancer through inhibition of XIAP and Akt/mTOR pathway

Recent Advances in the Phytochemistry of Bryophytes: Distribution, Structures and Biological Activity of Bibenzyl and Bisbibenzyl Compounds

Research on bryophyte phytochemistry has revealed the presence of different phytochemicals like fatty acids, terpenoids, small phenolic molecules, etc. Small phenolic molecules, i.e., bibenzyls (of two aromatic rings) and bisbibenzyls (four aromatic rings), are unique signature molecules of liverworts. The first bisbibenzyls marchantin A and riccardin A were discovered in two consecutive years, i.e., 1982 and 1983, respectively, by Asakawa and coworkers. Since then, about 70 bisbibenzyls have been reported. These molecules are characterized and identified using different spectroscopic techniques and surveyed for different bioactivity and structure-activity relations. Biochemistry is determined by the season, geography, and environment. In this review, quantitative and qualitative information on bibenzyls and bisbibenzyl compounds and their distribution in different liverworts across, geographies along withtraditional to advanced extraction methods, and characterization techniques are summarized. Also, a comprehensive account of characteristic spectra of different bisbibenzyl compounds, their subtypes, and their basic skeleton patterns are compared. A comprehensive table is provided here for the first time presenting the quantity of bibenzyls, bisbenzyls, and their derivatives found in bryophytes, mentioning the spectroscopic data and mass profiles of the compounds. The significance of these compounds in different bioactivities like antibiotic, antioxidative, antitumor, antivenomous, anti-influenza, insect antifeedant, cytotoxic, and anticancerous activities are surveyed and critically enumerated.

MOB kinase activator 1A acts as an oncogene by targeting PI3K/AKT/mTOR in ovarian cancer

BACKGROUND

To illuminate the precise roles of MOB Kinase Activator 1 A (MOB1A) in the development of ovarian cancer (OC).

METHODS

MOB1A expression and clinical data of OC were obtained from the public database on gene expression and proteomics. Meanwhile, verification of expression was carried out in Gene Expression Omnibus, the Human Protein Atlas, and OC cell lines. The prognosis of MOB1A was explored in the Kaplan-Meier plotter. RNA interference and lentivirus vectors were applied to construct knockdown and overexpressed cell models. Changes in the malignant behaviors of OC cells were detected by cholecystokinin octopeptide cell counting kit, wound healing, colony formation assay, transwell, flow cytometry assays, and in vivo experiments. Changes in proteins in the PI3K and autophagy-related makers were detected by western blot analysis.

RESULTS

The expression of MOB1A was significantly upregulated and accompanied by an inferior survival rate in OC. Knockdown of MOB1A inhibited the proliferation, invasion, migration, and cell cycle of OC cells, whereas induced cell autophagy. MOB1A upregulation had the opposite effects. In addition, bioinformatics analysis and western blot experiments showed that MOB1A plays an important role in the PI3K/AKT/mTOR pathway.

CONCLUSIONS

Our findings indicated that MOB1A is highly expressed and related to poor prognosis in OC. MOB1A plays a role in promoting the malignant biological behavior of tumor cells through PI3K/AKT/mTOR signaling pathway.

Autophagy: A challengeable paradox in cancer treatment

OBJECTIVE

Autophagy is an intracellular degradation pathway conserved in all eukaryotes from yeast to humans. This process plays a quality-control role by destroying harmful cellular components under normal conditions, maintaining cell survival, and establishing cellular adaptation under stressful conditions. Hence, there are various studies indicating dysfunctional autophagy as a factor involved in the development and progression of various human diseases, including cancer. In addition, the importance of autophagy in the development of cancer has been highlighted by paradoxical roles, as a cytoprotective and cytotoxic mechanism. Despite extensive research in the field of cancer, there are many questions and challenges about the roles and effects suggested for autophagy in cancer treatment. The aim of this study was to provide an overview of the paradoxical roles of autophagy in different tumors and related cancer treatment options.

METHODS

In this study, to find articles, a search was made in PubMed and Google scholar databases with the keywords Autophagy, Autophagy in Cancer Management, and Drug Design.

RESULTS

According to the investigation, some studies suggest that several advanced cancers are dependent on autophagy for cell survival, so when cancer cells are exposed to therapy, autophagy is induced and suppresses the anti-cancer effects of therapeutic agents and also results in cell resistance. However, enhanced autophagy from using anti-cancer drugs causes autophagy-mediated cell death in several cancers. Because autophagy also plays roles in both tumor suppression and promotion further research is needed to determine the precise mechanism of this process in cancer treatment.

CONCLUSION

We concluded in this article, autophagy manipulation may either promote or hinder the growth and development of cancer according to the origin of the cancer cells, the type of cancer, and the behavior of the cancer cells exposed to treatment. Thus, before starting treatment it is necessary to determine the basal levels of autophagy in various cancers.

TGF-β1 fucosylation enhances the autophagy and mitophagy via PI3K/Akt and Ras-Raf-MEK-ERK in ovarian carcinoma

Transforming growth factor-β, a cell secretion factor of the TGF-β superfamily, is involved in the regulation of cell proliferation, differentiation, cytoskeleton formation, migration, invasion and other biological behaviors. Autophagy and mitophagy play an important role in tumor progression by regulating self-digestion, and degradation and reuse of cells and mitochondria. In this study, changes in autophagy and mitophagy processes in ovarian cancer cells under TGF-β1 treatment were detected via Western blot and immunofluorescence, as well as the role of fucosylation modification. Changes in mitochondrial membrane potential in response to TGF-β1 and fucosylation were detected via immunofluorescence. The effects of TGF-β1 and its fucosylation on autophagic flux were further determined by transient transfection of cells with Ad-mRFP-GFP-LC3 adenovirus. TGF-β1 clearly promoted autophagy and mitophagy in ovarian cancer cells. TGF-β1 fucosylation stimulated these regulatory effects on ovarian cancer cells via modulation of PI3K/Akt and Ras-Raf-MEK-ERK pathways through TAK1. Our collective data support the physiological significance of TGF-β1 and provide a novel direction for targeted therapy for ovarian cancer.

Deoxyshikonin isolated from Arnebia euchroma inhibits colorectal cancer by down-regulating the PI3K/Akt/mTOR pathway

Context: Shikonins, a series of natural occurring naphthoquinones extracted from Arnebia euchroma (Royle) Jonst. (Boraginaceae), have antitumor activities and low toxicity. Objective: To illuminate potential activity and mechanism of shikonins against colorectal cancer (CRC). Materials and methods: Five shikonins were isolated from A. euchroma, and elucidated by extensive spectroscopic analysis. Anti-proliferative activities of shikonins (0-100 μg/mL) on human colorectal cells were evaluated by MTT and CCK-8 for 24 or 48 h. Cell apoptosis and cycle distribution were examined by FCM analysis. The expression of PI3K/Akt/mTOR pathway mRNAs and proteins was analysed by RT-PCR and Western blot, respectively. Cell viability, cell apoptosis, cell cycle and protein expression were measured, when co-treated with PI3K/Akt/mTOR pathway inhibitors. The in vivo activity of deoxyshikonin was evaluated using xenograft tumour model. Results: Deoxyshikonin and another four shikonins were isolated and identified. Deoxyshikonin exhibited anti-proliferative activity with IC₅₀ of 10.97 μM against HT29 cells. Moreover, the percentage of early apoptotic cells and G0/G1 cells increased from 1 to 29% and 44 to 67% with 0-50 μg/mL deoxyshikonin, respectively. Deoxyshikonin also down-regulated the expression of PI3K, p-PI3K, Akt, p-Akt308 and mTOR proteins in HT29 and DLD-1 cells. Moreover, LY294002, NVP-BEZ235 and MK-2206 can make deoxyshikonin more cell proliferation inhibited, cell cycle arrested at G0/G1 and apoptosis promoted. In vivo study, the weight of tumour tissues at deoxyshikonin groups was significantly reduced compared with the control group, and PI3K, p-PI3K, Akt, p-Akt308 and mTOR expression was decreased. Discussion and conclusions: We can conclude that deoxyshikonin isolated from Arnebia euchroma inhibited CRC through the PI3K/Akt/mTOR pathway.

FAM83D inhibits autophagy and promotes proliferation and invasion of ovarian cancer cells via PI3K/AKT/mTOR pathway

Ovarian cancer is one of the most lethal malignant tumors in women. The family with sequence similarity 83, member D (FAM83D) plays an important role in several cancers, but its function and underlying mechanism in ovarian cancer remain unknown. To investigate the role of FAM83D in ovarian cancer, the expression of FAM83D was determined by immunohistochemistry in tissue microarray slide. Cellular proliferation and invasion were detected by 5-Ethynyl-2'-deoxyuridine assays and transwell invasion assays. The correlations between FAM83D and autophagy were detected by western blot analysis and confocal microscopy. Western blot analysis was used to identify the protein expression of FAM83D, phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR) and Sequestosome 1 (P62). Tumorigenesis in nude mice was used to explore the function of FAM83D in vivo. We found high expression level of FAM83D in ovarian cancer tissues as compared to the normal ovarian tissues. Knockdown of FAM83D in SKOV3 cells enhanced autophagy and inhibited the proliferation and invasion in vitro, whereas ectopic expression of FAM83D in A2780 cells exerted an opposite effect. Mechanistically, overexpression of FAM83D activated the PI3K/AKT/mTOR pathway, and Torin1 could suppress FAM83D-induced cell proliferation and invasion. In vivo, overexpression FAM83D promoted tumor growth. Overall, FAM83D promoted ovarian cancer cell invasion and proliferation, while inhibited autophagy via the PI3K/AKT/mTOR signaling pathway. Our results suggest that FAM83D may be a candidate oncogene in ovarian cancer, which provides a fresh perspective of FAM83D in ovarian cancer.

Autophagy as an emerging therapy target for ovarian carcinoma

Autophagy is a conserved cellular self-digestion pathway for maintenance of homeostasis under basal and stressed conditions. Autophagy plays pivotal roles in the pathogenesis of many diseases, such as aging-related diseases, autoimmune diseases, cardiovascular diseases, and cancers. Of special note is that accumulating data suggest an intimate relationship between autophagy and ovarian carcinoma. Autophagy is well identified to act as either as a tumor-suppressor or as a tumor-promoter in ovarian carcinoma. The exact function of autophagy in ovarian carcinoma is highly dependent on the circumstances of cancer including hypoxic, nutrient-deficient, chemotherapy and so on. However, the mechanism underlying autophagy associated with ovarian carcinoma remains elusive, the precise role of autophagy in ovarian carcinoma also remains undetermined. In this review, we tried to sum up and discuss recent research achievements of autophagy in ovarian cancer. Moreover, waves of novel therapies ways for ovarian carcinoma based on the functions of autophagy were collected.

Targeting autophagy augments the activity of DHA-E3 to overcome p-gp mediated multi-drug resistance

Multidrug resistance (MDR) is a major obstacle for successful chemotherapy treatment. Searching for effective MDR modulators and combining them with anticancer drug therapies has been a promising strategy against clinical MDR. In our previous study, we have found that DHA-E3, a synthetic derivative of DHA, has the ability to modulate the function of P-glycoprotein (P-gp) and reverse MDR in cancer cells. In this study, we further evaluated the reversal effect of DHA-E3 on MDR and explored its mechanism of action in vitro. Our findings showed that DHA-E3 significantly potentiated the cytotoxicity of vincristine(VCR) and adriamycin(ADR) in the P-gp over-expressing KB/VCR and A02 cells. The mechanistic study found that DHA-E3 increased the intracellular accumulation of ADR and rhodamine-123 by directly inhibiting the drug-transport activity of P-gp. In the present study, we found that DHA-E3 not only reversed MDR, but also induced autophagy in MDR cancer cells. To determine whether DHA-E3-induced autophagy is an adaptive survival response or contributes to cell death, we manipulated autophagic activity using autophagy inhibitor 3-MA or siRNA targeting Beclin1. We found that the reversal activity of DHA-E3 was significantly exacerbated in the presence of 3-MA or blocking the expression of Beclin1. These results suggest that DHA-E3 is capable of reversing MDR, induction of autophagy represents a defense mechanism and inhibiting this process may be an effective strategy to augment the reversal activity of reversal agents.

Asiatic acid exerts anticancer potential in human ovarian cancer cells via suppression of PI3K/Akt/mTOR signalling

Context Asiatic acid, a triterpenoid compound extracted from the tropical medicinal plant Centella asiatica (Family: Apiaceae), has exhibited various biological activities. Objective This study was performed to investigate the cytotoxic effects of asiatic acid on human ovarian cancer cells. Materials and methods SKOV3 and OVCAR-3 ovarian cancer cells were exposed to different concentrations of asiatic acid (10-100 μg/mL) for 72 or 48 h. Cell viability, colony formation, cell cycle distribution, apoptotic response were examined. Involvement of the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway was tested. Results At the concentration of 40 μg/mL, asiatic acid caused about 50% reduction in the viability of ovarian cancer cells, but had little effect on the viability of normal human ovarian epithelial cells. Asiatic acid at 10 μg/mL reduced colony formation of ovarian cancer cells by 25-30%. Asiatic acid-treated cells showed a cell cycle arrest at the G0/G1 phase and 7- to 10-fold increase in apoptosis. The phosphorylation levels of PI3K, Akt and mTOR were remarkably lower in asiatic acid-treated cells. Overexpression of constitutively active Akt partially reversed the cytotoxic effects of asiatic acid, as evidenced by increased cell viability and colony formation. Furthermore, knockdown of Akt mimicked the growth-suppressive activity of asiatic acid. Discussion and conclusion These results provide first the evidence for the anticancer potential of asiatic acid in ovarian cancer cells, partially via inactivation of the PI3K/Akt/mTOR pathway. Asiatic acid may represent a potential therapeutic agent for ovarian cancer.

Docosahexaenoic Acid Attenuated Experimental Chronic Colitis in Interleukin 10-Deficient Mice by Enhancing Autophagy Through Inhibition of the mTOR Pathway

BACKGROUND

In the battle against Crohn's disease, autophagy stimulation is a promising therapeutic option-one both new and newly rediscovered. In experimental models, docosahexaenoic acid (DHA)-a long-chain polyunsaturated fatty acid-has been demonstrated to be useful in the treatment of inflammatory bowel disease through inhibition of the nuclear factor-κB pathway. However, the impact of DHA on autophagy in the colon remains unclear.

METHODS

Mice were divided into 3 groups: wild type (placebo), the interleukin 10 knockout group (IL-10^-/-, placebo), and the DHA group (IL-10^-/-, DHA). DHA was administered to IL-10^-/- mice by gavage at a dosage of 35.5 mg/kg/d for 2 weeks. The severity of colitis, expression of proinflammatory cytokines, expression/distribution of LC3B, and mTOR signaling pathway were evaluated in the proximal colon tissues collected from all mice at the end of the experiment.

RESULTS

DHA administration ameliorated experimental colitis in the IL-10^-/- mice, as demonstrated by decreased proinflammatory cytokines (TNF-α and IFN-γ), reduced infiltration of inflammatory cells, and lowered histologic scores of the proximal colon mucosa. Moreover, in the DHA-treated mice, enhanced autophagy was observed to be associated with (1) increased expression and restoration of the distribution integrity of LC3B in the colon and (2) inhibition of the mTOR signaling pathway.

CONCLUSION

This study showed that DHA therapy could attenuate experimental chronic colitis in IL-10^-/- mice by triggering autophagy via inhibition of the mTOR pathway.