E2F2 inhibition induces autophagy via the PI3K/Akt/mTOR pathway in gastric cancer.
Ontology highlight
ABSTRACT: Background
E2F2 is a member of the E2F transcription factor family and has important but not fully understood biological functions in cancers. The biological role of E2F2 in gastric cancer (GC) also remains unclear.Methods
We examined the expression levels of E2F2 in GC using publicly available datasets such as TIMER, Oncomine, GEPIA, UALCAN, etc., and in our patient cohort, using quantitative real-time PCR, western blotting, and immunohistochemistry. We further investigated the effects of E2F2 on phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling, autophagy, and the migration and invasion of GC cells by the wound healing assay, Transwell assay and transmission electron microscopy.Results
E2F2 was highly expressed in both GC tissues and cells compared with normal gastric tissues/cells. High E2F2 expression was associated with poor overall survival (OS). In addition, the expression of E2F2 in GC was strongly correlated with a variety of immune markers. E2F2 overexpression promoted the migration and invasiveness of GC cells in vitro through inhibition of PI3K/Akt/mTOR-mediated autophagy.Conclusion
High E2F2 expression was associated with the characteristics of invasive tumors and poor prognosis. E2F2 also had potential modulatory effects on tumor immunity. We discovered a novel function of E2F2 in the regulation of PI3K/Akt/mTOR-mediated autophagy and the downstream processes of cell migration and invasion.
SUBMITTER: Li H
PROVIDER: S-EPMC8202834 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Myricetin, a natural flavonoid present in berries, nuts, and green tea, is well-known for its anticancer properties. Even though several previous studies have reported the anticancer effects induced by myricetin, these effects have not yet been confirmed in the adenocarcinoma gastric cell line (AGS). Moreover, the exact mechanisms of myricetin-induced apoptosis and autophagy have not been clearly identified either. Therefore, in this study, we aimed to examine the role of myricetin in inducing apoptosis and autophagy in AGS gastric cancer cells. First, the survival rate of AGS gastric cancer cells was assessed using the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) cell viability assay. Thereafter, the rate of apoptosis was analyzed using4',6-diamidino-2-phenylindole (DAPI) staining as well as annexin V and propidium iodide (PI) staining, and the expression of the proteins associated with apoptosis, PI3K/Akt/mTOR pathway, and autophagy was examined by western blotting. We observed that myricetin reduced the survival rate of AGS gastric cancer cells by inhibiting the PI3K/Akt/mTOR pathway, thereby inducing apoptosis and autophagy. Similar results were also obtained in vivo, and tumor growth was inhibited. Therefore, in the AGS gastric cancer cells, myricetin seems to inhibit the PI3K/Akt/mTOR pathway, which in turn leads to apoptosis in vitroand in vivo, cell-protective autophagy, as well as inhibition of cancer cell proliferation. These results indicate the potential of myricetin as a natural anticancer agent.
| S-EPMC9065623 | biostudies-literature
Project description:SOCS5 is a member of the suppressor of cytokine signaling (SOCS) protein family with important yet incompletely understood biological functions in cancer. In hepatocellular carcinoma (HCC), controversial tumor-promoting and tumor-suppressive roles of SOCS5 have been reported. Our study aims to unravel novel functions of SOCS5 in HCC, especially that affecting metastasis. We examined the expression levels of SOCS5 in HCC using publicly available datasets, and in our patient cohort, using quantitative real-time PCR, western blotting, and immunohistochemistry. The association of SOCS5 expression with clinical pathological data of HCC patients was examined and that with the mTOR pathway was predicted. We further studied the effects of SOCS5 on PI3K/Akt/mTOR activity; HCC cell autophagy, migration, and invasion; and HCC cell metastasis in vitro and in vivo. We observed that SOCS5 was significantly overexpressed in HCC tissues, compared to adjacent non-tumor liver tissues, in both the public datasets and in our patient cohort. SOCS5 overexpression was significantly and inversely correlated with HCC patient prognosis. Moreover, SOCS5 overexpression promoted HCC cell migration and invasion in vitro by inactivating PI3K/Akt/mTOR-mediated autophagy. Conversely, SOCS5 inhibition suppressed HCC cell migration and invasion in vitro by activating PI3K/Akt/mTOR-mediated autophagy. Dual inhibition of SOCS5 and mTOR further enhanced autophagy and the subsequent anti-metastatic effects on HCC cells. In vivo, stable knockdown of SOCS5 reduced HCC cell metastasis. Overall, our study revealed a novel metastasis-promoting function of SOCS5 in HCC, acting via the PI3K/Akt/mTOR-mediated autophagy pathway. Combined inhibition of SOCS5 and mTOR may be a potential therapeutic approach to inhibit HCC metastasis and prolong patient survival.
| S-EPMC6690952 | biostudies-literature
Project description:Caffeine is one of the most frequently ingested neuroactive compounds. All known mechanisms of apoptosis induced by caffeine act through cell cycle modulation or p53 induction. It is currently unknown whether caffeine-induced apoptosis is associated with other cell death mechanisms, such as autophagy. Herein we show that caffeine increases both the levels of microtubule-associated protein 1 light chain 3-II and the number of autophagosomes, through the use of western blotting, electron microscopy and immunocytochemistry techniques. Phosphorylated p70 ribosomal protein S6 kinase (Thr389), S6 ribosomal protein (Ser235/236), 4E-BP1 (Thr37/46) and Akt (Ser473) were significantly decreased by caffeine. In contrast, ERK1/2 (Thr202/204) was increased by caffeine, suggesting an inhibition of the Akt/mTOR/p70S6K pathway and activation of the ERK1/2 pathway. Although insulin treatment phosphorylated Akt (Ser473) and led to autophagy suppression, the effect of insulin treatment was completely abolished by caffeine addition. Caffeine-induced autophagy was not completely blocked by inhibition of ERK1/2 by U0126. Caffeine induced reduction of mitochondrial membrane potentials and apoptosis in a dose-dependent manner, which was further attenuated by the inhibition of autophagy with 3-methyladenine or Atg7 siRNA knockdown. Furthermore, there was a reduced number of early apoptotic cells (annexin V positive, propidium iodide negative) among autophagy-deficient mouse embryonic fibroblasts treated with caffeine than their wild-type counterparts. These results support previous studies on the use of caffeine in the treatment of human tumors and indicate a potential new target in the regulation of apoptosis.
| S-EPMC3039768 | biostudies-literature
Project description:BackgroundBladder cancer (BCa) is one of the most frequent malignant tumors globally, with a significant morbidity and mortality rate. Gene expression dysregulation has been proven to play a critical role in tumorigenesis. Ras-related C3 botulinum toxin substrate3 (RAC3), which is overexpressed in several malignancies and promotes tumor progression, has been identified as an oncogene. However, RAC3 has important but not fully understood biological functions in cancer. Our research aims to reveal the new functions and potential mechanisms of RAC3 involved in BCa progression.MethodsWe explored the expression level of RAC3 and its relationship with prognosis by publicly accessible BCa datasets, while the correlation of RAC3 expression with clinicopathological variables of patients was analyzed. In vitro and in vivo proliferation, migration, autophagy, and other phenotypic changes were examined by constructing knockdown(KD)/overexpression(OE) RAC3 cells and their association with PI3K/AKT/mTOR pathway was explored by adding autophagy-related compounds.ResultsCompared with non-tumor samples, RAC3 was highly expressed in BCa and negatively correlated with prognosis. KD/OE RAC3 inhibited/promoted the proliferation and migration of BCa cells. Knockdown RAC3 caused cell cycle arrest and decreased adhesion without affecting apoptosis. Inhibition of RAC3 activates PI3K/AKT/mTOR mediated autophagy and inhibits proliferation and migration of BCa cells in vivo and in vitro. Autophagy inhibitor 3MA can partially rescue the metastasis and proliferation inhibition effect caused by RAC3 inhibition. Inhibit/activate mTOR enhanced/impaired autophagy, resulting in shRAC3-mediated migration defect exacerbated/rescued.ConclusionRAC3 is highly expressed in BCa. It is associated with advanced clinicopathological variables and poor prognosis. Knockdown RAC3 exerts an antitumor effect by enhancing PI3K/AKT/mTOR mediated autophagy. Targeting RAC3 and autophagy simultaneously is a potential therapeutic strategy for inhibiting BCa progression and prolonging survival.
| S-EPMC9279623 | biostudies-literature
Project description:BackgroundPeritoneal metastasis (PM) occurs frequently in patients with gastric cancer (GC) and confers poor survival. Lipid metabolism acts as a non-negligible regulator in epithelial-mesenchymal transition (EMT), which is crucial for the metastasis of GC. As apolipoprotein C2 (APOC2) is a key activator of lipoprotein lipase for triglyceride metabolism, the exact mechanism of APOC2 remains largely unknown in GC.MethodsTandem mass tags identified differentially expressed proteins between human PM and GC tissues, and showed that APOC2 overexpressed in PM tissues, which was further confirmed by immunoblotting, immunohistochemistry, and ELISA. Global gene expression changes were identified in APOC2 knockdown cells via RNA-sequencing. The role of APOC2 in lipid metabolism of GC cells was assessed via the Seahorse XF analyzer and lipid staining assays. The biological role of APOC2 in GC cells was determined by 3D Spheroid invasion, apoptosis, colony formation, wound healing, transwell assay, and mouse models. The interaction between APOC2 and CD36 was analyzed by co-immunoprecipitation and biolayer interferometry. The underlying mechanisms were investigated using western blot technique.ResultsAPOC2 overexpressed in GC PM tissues. Upregulation of APOC2 correlated with a poor prognosis in GC patients. APOC2 promoted GC cell invasion, migration, and proliferation via CD36-mediated PI3K/AKT/mTOR signaling activation. Furthermore, APOC2-CD36 axis upregulated EMT markers of GC cells via increasing the phosphorylation of PI3K, AKT, and mTOR. Knockdown either APOC2 or CD36 inhibited the malignant phenotype of cancer cells, and delayed GC PM progression in murine GC models.ConclusionAPOC2 cooperates with CD36 to induce EMT to promote GC PM via PI3K/AKT/mTOR pathway. APOC2-CD36 axis may be a potential target for the treatment of aggressive GC.
| S-EPMC8351524 | biostudies-literature
Project description:Osteoarthritis (OA) is a highly prevalent and chronic disorder that is associated with a substantial social and economic burden. Itaconate, as an important regulator of cellular inflammation, is a metabolite synthesised by an enzyme encoded by immune-responsive gene 1. However, there are few studys regarding the effects of itaconate on OA. Here, we show the effect of the cell-permeable itaconate derivative 4-octyl itaconate (OI) on OA. OI attenuates the chondrocyte apoptosis induced by interleukin 1β (IL-1β) in vitro, indicating that OI protect chondrocytes against apoptosis. Moreover, OI ameliorates the chondrocyte autophagy inhibition induced by IL-1β via the inhibition of PI3K/AKT/mTOR signalling pathway. Finally, OI enhances autophagy and reduces cartilage degradation in a rat model of OA established by destabilization of medial meniscus (DMM). In summary, our findings reveal that OI is involved in regulating the progression of OA. The above results shed light on the treatment of OA.
| S-EPMC9242998 | biostudies-literature
Project description:Autoimmune hepatitis (AIH) results from an autoimmune-mediated chronic inflammatory response against liver cells. Defective self-tolerance and dysfunctional dendritic cells (DCs) play a regulatory role in AIH. Itaconate has recently attracted attention in the field of immunometabolism because of its crucial role as an anti-inflammatory metabolite that negatively regulates the inflammatory response. However, the underlying mechanism of itaconate mediation of DCs in AIH remains unclear. In this study, we found that itaconate acts as an anti-inflammatory factor in the liver. Endogenous itaconate levels were significantly increased in mice with S100-induced AIH model and correlated with upregulation of the immune-responsive gene 1 expression. However, the anti-inflammatory response from endogenously itaconate may not represent the effects exogenously-produced itaconate. We investigated the anti-inflammatory response from exogenous itaconate in S100-induced AIH, and our results showed that itaconate treatment attenuated liver histopathological damage, hepatocyte apoptosis, aminotransferase elevation, and IL-6 production in the S100-induced AIH model. In addition, Itaconate decreased glycolysis to suppress the maturation of DCs in the liver and spleen of AIH models, thereby directly regulating differentiation of Th17 and Tregs in vivo. The percentage of Th17 cells among the CD4+ population were decreased and Tregs were increased (P < 0.05). Furthermore, Itaconate-induced bone marrow-derived monocytes suppressed CD4+cells proliferation. In vitro and in vivo, we found that itaconate suppressed autophagy via activating the PI3K/AKT/mTOR signalling pathway in bone marrow-derived DCs and liver tissues. We further investigated the function of Itaconate on DC-specific mTOR-deficient mice. mTOR-deficient DCs augmented inflammatory reactions in mTORDC-/- AIH mice and induced autophagy. MHY1485 (an agonist of mTOR) and itaconate significantly alleviated the inflammatory reaction and autophagy signalling. In conclusion, itaconate ameliorate liver inflammation in S100-induced AIH mice by regulating the PI3K/AKT/mTOR pathway to decrease DCs autophagy and maturation. These results provide insight useful for treating AIH.
| S-EPMC10336503 | biostudies-literature
Project description:BackgroundCurrent chemotherapeutic agents based on apoptosis induction are lacking in desired efficacy. Therefore, there is continuous effort to bring about new dimension in control and gradual eradication of cancer by means of ever evolving therapeutic strategies. Various forms of PCD are being increasingly implicated in anti-cancer therapy and the complex interplay among them is vital for the ultimate fate of proliferating cells. We elaborated and illustrated the underlying mechanism of the most potent Andrographolide analogue (AG-4) mediated action that involved the induction of dual modes of cell death-apoptosis and autophagy in human leukemic U937 cells.Principal findingsAG-4 induced cytotoxicity was associated with redox imbalance and apoptosis which involved mitochondrial depolarisation, altered apoptotic protein expressions, activation of the caspase cascade leading to cell cycle arrest. Incubation with caspase inhibitor Z-VAD-fmk or Bax siRNA decreased cytotoxic efficacy of AG-4 emphasising critical roles of caspase and Bax. In addition, AG-4 induced autophagy as evident from LC3-II accumulation, increased Atg protein expressions and autophagosome formation. Pre-treatment with 3-MA or Atg 5 siRNA suppressed the cytotoxic effect of AG-4 implying the pro-death role of autophagy. Furthermore, incubation with Z-VAD-fmk or Bax siRNA subdued AG-4 induced autophagy and pre-treatment with 3-MA or Atg 5 siRNA curbed AG-4 induced apoptosis-implying that apoptosis and autophagy acted as partners in the context of AG-4 mediated action. AG-4 also inhibited PI3K/Akt/mTOR pathway. Inhibition of mTOR or Akt augmented AG-4 induced apoptosis and autophagy signifying its crucial role in its mechanism of action.ConclusionsThus, these findings prove the dual ability of AG-4 to induce apoptosis and autophagy which provide a new perspective to it as a potential molecule targeting PCD for future cancer therapeutics.
| S-EPMC4593644 | biostudies-literature
Project description:Gastric cancer (GC) is among the five most common malignancies worldwide. Traditional chemotherapy cannot efficiently treat the disease and faces the problems of side effects and chemoresistance. Polygoni orientalis Fructus (POF), with flavonoids as the main bioactive compounds, exerts anti-cancer potential. In this study, we compared the anti-GC effects of the main flavonoids from POF and investigated the anti-cancer effects of eriodictyol towards GC both in vitro and in vivo. CCK-8 assays were performed to examine the inhibitory effects of common flavonoids from POF on GC cell viability. Colony formation assays were used to determine cell proliferation after eriodictyol treatment. Cell cycle distribution was analyzed using flow cytometry. Induction of apoptosis was assessed with Annexin V/PI staining and measurement of related proteins. Anti-cancer effects in vivo were investigated using a xenograft mouse model. Potential targets of eriodictyol were clarified by network pharmacological analysis, evaluated by molecular docking, and validated with Western blotting. We found that eriodictyol exhibited the most effective inhibitory effect on cell viability of GC cells among the common flavonoids from POF including quercetin, taxifolin, and kaempferol. Eriodictyol suppressed colony formation of GC cells and induced cell apoptosis. The inhibitory effects of eriodictyol on tumor growth were also validated using a xenograft mouse model. Moreover, no obvious toxicity was identified with eriodictyol treatment. Network pharmacology analysis revealed that PI3K/AKT signaling ranked first among the anti-GC targets. The molecular docking model of eriodictyol and PI3K was constructed, and the binding energy was evaluated. Furthermore, efficient inhibition of phosphorylation and activation of PI3K/AKT by eriodictyol was validated in GC cells. Taken together, our results identify eriodictyol as the most effective anti-GC flavonoids from POF and the potential targets of eriodictyol in GC. These findings suggest that eriodictyol has the potential to be a natural source of anti-GC agents.
| S-EPMC9788236 | biostudies-literature
Project description:Qianlie Xiaozheng decoction (QLXZD), a traditional Chinese medicinal formula, has been used clinically to treat advanced prostate cancer (PCa) for more than 10 years. However, experimental evidence supporting its efficacy is lacking. Here, we investigated the anticancer properties and molecular mechanism of QLXZD in vitro in a human PCa cell line (PC3) and in vivo using PC3 xenografts in nude mice. We confirmed the antineoplastic activity of QLXZD by analyzing cell viability and tumor volume growth, which decreased significantly compared to that of the controls. Autophagy following QLXZD treatment was detected morphologically using transmission electron microscopy and was confirmed by measuring the expression of autophagy markers (LC3-II and p62) using fluorescence analysis, flow cytometry, and western blotting. Increasing autophagic flux induced by QLXZD was monitored via pmCherry-GFP-LC3 fluorescence analysis. QLXZD-induced autophagic cell death was alleviated by the autophagy inhibitors, 3-methyl adenine and hydroxychloroquine. We evaluated the total expression and phosphorylation levels of proteins involved in the Akt/mTOR pathway regulating autophagy. Phosphorylation of Akt, mTOR, and p70S6K, but not total protein levels, decreased following treatment. This is the first study to demonstrate the autophagy-related mechanistic pathways utilized during QLXZD-mediated antitumor activity both in vitro and in vivo. These findings support the clinical use of QLXZD for PCa treatment.
| S-EPMC5893804 | biostudies-literature