Roles of phosphatidylinositol-3-kinases signaling pathway in inflammation-related cancer:Impact of rs10889677 variant and buparlisib in colitis-associated cancer

BACKGROUND Phosphatidylinositol-3-kinases(PI3K)is a well-known route in inflammationrelated cancer.Recent discovery on PI3K-related genes revealed a potential variant that links ulcerative colitis(UC)and colorectal cancer(CRC)with colitisassociated cancer(CAC).PI3K/AKT pathway has been recommended as a potential additional therapeutic option for CRC due to its substantial role in modifying cellular processes.Buparlisib is a pan-class I PI3K inhibitor previously shown to reduce tumor growth.AIM To investigate the regulation of rs10889677 and the role of buparlisib in the PI3K signaling pathway in CAC pathogenesis.METHODS Genomic DNA from 32 colonic samples,including CAC(n=7),UC(n=10)and CRC(n=15),was sequenced for the rs10889677 mutation.The mutant and wildtype fragments were amplified and cloned in the pmirGLO vector.The luciferase activity of cloned vectors was assessed after transfection into the HT29 cell line.CAC mice were induced by a mixture of a single azoxymethane injection and three cycles of dextran sulphate sodium,then buparlisib was administered after 14 d.The excised colon was subjected to immunohistochemistry for Ki67 and Cleaved-caspase-3 markers and quantitative real-time polymerase chain reaction analysis for Pdk1 and Sgk2.RESULTS Luciferase activity decreased by 2.07-fold in the rs10889677 mutant,confirming the hypothesis that the variant disrupted miRNA binding sites,which led to an increase in IL23R expression and the activation of the PI3K signaling pathway.Furthermore,CAC-induced mice had a significantly higher disease activity index(P<0.05).Buparlisib treatment significantly decreased mean weight loss in CAC-induced mice(P<0.05),reduced the percentage of proliferating cells by 5%,and increased the number of apoptotic cells.The treatment also caused a downward trend of Pdk1 expression and significantly decreased Sgk2 expression.CONCLUSION Our findings suggested that the rs10889677 variant as a critical initiator of the PI3K signaling pathway,and buparlisib had the ability to prevent PI3K-non-AKT activation in the pathophysiology of CAC.

Osteopontin promotes gastric cancer progression via phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors.Osteopontin(OPN)is thought to be closely related to the occurrence,metastasis and prognosis of many types of tumors.AIM To investigate the effects of OPN on the proliferation,invasion and migration of GC cells and its possible mechanism.METHODS The mRNA and protein expression of OPN in the GC cells were analyzed by realtime quantitative-reverse transcription polymerase chain reaction and western blotting,and observe the effect of varying degree expression OPN on the proliferation and other behaviors of GC.Next,the effects of OPN knockdown on GC cells migration and invasion were examined.The short hairpin RNA(shRNA)and negative control shRNA targeting OPN-shRNA were transfected into the cells according to the manufacturer’s instructions.Non transfected cells were classified as control in the identical transfecting process.24 h after RNA transfection cell proliferation activity was detected by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide assay,and cell invasiveness and migration were detected by Trans well assay.Meanwhile,the expression of protein kinase B(AKT),matrix metalloproteinase 2(MMP-2)and vascular endothelial growth factor(VEGF)in the human GC cell lines was detected by reverse transcription polymerase chain reaction and western blotting.RESULTS The results of this study revealed that OPN mRNA and protein expression levels were highly expressed in SGC-7901 cells.OPN knockdown by specific shRNA noticeably reduced the capabilities of proliferation,invasion and migration of SGC-7901 cells.Moreover,in the experiments of investigating the underlying mechanism,results showed that OPN knockdown could down-regulated the expression of MMP-2 and VEGF,it also decreased the phosphorylation of AKT.Meanwhile,the protein expression levels of MMP-2,VEGF and phosphorylated AKT was noticeable lower than that in control group in the GC cells after they were added to phosphatidylinositol-3-kinase(PI3K)inhibitor(LY294002).CONCLUSION These results suggested that OPN though PI3K/AKT/mammalian target of rapamycin signal pathway to upregulate MMP-2 and VEGF expression,which contribute SGC-7901 cells to proliferation,invasion and migration.Thus,our results demonstrate that OPN may serve as a novel prognostic biomarkers as well as a potential therapeutic targets for GC.

Role of phosphoinositide 3-kinase in the pathogenesis of acute pancreatitis

A large body of experimental and clinical data supports the notion that inflammation in acute pancreatitis has a crucial role in the pathogenesis of local and systemic damage and is a major determinant of clinical severity.Thus,research has recently focused on molecules that can regulate the inflammatory processes,such as phosphoinositide 3-kinases(PI3Ks),a family of lipid and protein kinases involved in intracellular signal transduction.Studies using genetic ablation or pharmacologic inhibitors of different PI3 K isoforms,in particular the class I PI3Kδ and PI3Kγ,have contributed to a greater understanding of the roles of these kinases in the modulation of inflammatory and immune responses.Recent data suggest that PI3 Ks are also involved in the pathogenesis of acute pancreatitis.Activation of the PI3K signaling pathway,and in particular of the class IB PI3Kγ isoform,has a significant role in those events which are necessary for the initiation of acute pancreatic injury,namely calcium signaling alteration,trypsinogen activation,and nuclear factor-κB transcription.Moreover,PI3Kγ is instrumental in modulating acinar cell apoptosis,and regulating local neutrophil infiltration and systemic inflammatory responses during the course of experimental acute pancreatitis.The availability of PI3 K inhibitors selective for specific isoforms may provide new valuable therapeutic strategies to improve the clinical course of this disease.This article presents a brief summary of PI3 K structure and function,and highlights recent advances that implicate PI3 Ks in the pathogenesis of acute pancreatitis.

Effects of small interfering RNA inhibit Class Ⅰ phosphoinositide 3-kinase on human gastric cancer cells

AIM:To investigate the effects of small interfering RNA(siRNA)-mediated inhibition of Class Ⅰ phosphoinositide 3-kinase(Class Ⅰ PI3K) signal transduction on the proliferation,apoptosis,and autophagy of gastric cancer SGC7901 and MGC803 cells.METHODS:We constructed the recombinant replication adenovirus PI3K(I)-RNA interference(RNAi)-green fluorescent protein(GFP) and control adenovirus NCRNAi-GFP,and infected it into human gastric cancer cells.MTT assay was used to determine the growth rate of the gastric cancer cells.Activation of autophagy was monitored with monodansylcadaverine(MDC) staining after adenovirus PI3K(I)-RNAi-GFP and control adenovirus NC-RNAi-GFP treatment.Immunofluorescence staining was used to detect the expression of microtubule-associated protein 1 light chain 3(LC3).Mitochondrial membrane potential was measured using the fluorescent probe JC-1.The expression of autophagy was monitored with MDC,LC3 staining,and transmission electron microscopy.Western blotting was used to detect p53,Beclin-1,Bcl-2,and LC3 protein expression in the culture supernatant.RESULTS:The viability of gastric cancer cells was inhibited after siRNA targeting to the Class Ⅰ PI3K blocked Class Ⅰ PI3K signal pathway.MTT assays revealed that,after SGC7901 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP,the rate of inhibition reached 27.48% ± 2.71% at 24 h,41.92% ± 2.02% at 48 h,and 50.85% ± 0.91% at 72 h.After MGC803 cancer cells were treated with adenovirus PI3K(I)-RNAiGFP,the rate of inhibition reached 24.39% ± 0.93% at 24 h,47.00% ± 0.87% at 48 h,and 70.30% ± 0.86% at 72 h(P < 0.05 compared to control group).It was determined that when 50 MOI,the transfection efficiency was 95% ± 2.4%.Adenovirus PI3K(I)RNAi-GFP(50 MOI) induced mitochondrial dysfunction and activated cell apoptosis in SGC7901 cells,and the results described here prove that RNAi of Class Ⅰ PI3K induced apoptosis in SGC7901 cells.The results showed that adenovirus PI3K(I)-RNAi-GFP transfection induced punctate distribution of LC3 immunoreactivity,indicating increased formation of autophagosomes.The results showed that the basal level of Beclin-1 and LC3 protein in SGC7901 cells was low.After incubating with adenovirus PI3K(I)-RNAi-GFP(50 MOI),Beclin-1,LC3,and p53 protein expression was significantly increased from 24 to 72 h.We also found that Bcl-2 protein expression down-regulated with the treatment of adenovirus PI3K(I)-RNAi-GFP(50 MOI).A number of isolated membranes,possibly derived from ribosomefree endoplasmic reticulum,were seen.These isolated membranes were elongated and curved to engulf a cytoplasmic fraction and organelles.We used transmission electron microscopy to identify ultrastructural changes in SGC7901 cells after adenovirus PI3K(I)RNAi-GFP(50 MOI) treatment.Control cells showed a round shape and contained normal-looking organelles,nucleus,and chromatin,while adenovirus PI3K(I)-RNAiGFP(50 MOI)-treated cells exhibited the typical signs of autophagy.CONCLUSION:After the Class Ⅰ PI3K signaling pathway has been blocked by siRNA,the proliferation of cells was inhibited and the apoptosis of gastric cancer cells was enhanced.

Herbal cake-partitioned moxibustion inhibits colonic autophagy in Crohn’s disease via signaling involving distinct classes of phosphatidylinositol 3-kinases

BACKGROUND Autophagy is an evolutionarily conserved biological process in eukaryotic cells that involves lysosomal-mediated degradation and recycling of related cellular components.Recent studies have shown that autophagy plays an important role in the pathogenesis of Crohn’s disease(CD).Herbal cake-partitioned moxibustion(HM)has been historically practiced to treat CD.However,the mechanism by which HM regulates colonic autophagy in CD remains unclear.AIM To observe whether HM can alleviate CD by regulating colonic autophagy and to elucidate the underlying mechanism.METHODS Rats were randomly divided into a normal control(NC)group,a CD group,an HM group,an insulin+CD(I+CD)group,an insulin+HM(I+HM)group,a rapamycin+CD(RA+CD)group,and a rapamycin+HM(RA+HM)group.2,4,6-trinitrobenzenesulfonic acid was administered to establish a CD model.The morphology of the colonic mucosa was observed by hematoxylin-eosin staining,and the formation of autophagosomes was observed by electron microscopy.The expression of autophagy marker microtubule-associated protein 1 light chain 3 beta(LC3B)was observed by immunofluorescence staining.Insulin and rapamycin were used to inhibit and activate colonic autophagy,respectively.The mRNA expression levels of phosphatidylinositol 3-kinase class I(PI3KC1),Akt1,LC3B,sequestosome 1(p62),and mammalian target of rapamycin(mTOR)were evaluated by RT-qPCR.The protein expression levels of interleukin 18(IL-18),tumor necrosis factor-α(TNF-α),nuclear factorκB/p65(NF-κB p65),LC3B,p62,coiled-coil myosin-like BCL2-interacting protein(Beclin-1),p-mTOR,PI3KC1,class III phosphatidylinositol 3-kinase(PI3KC3/Vps34),and p-Akt were evaluated by Western blot analysis.RESULTS Compared with the NC group,the CD group showed severe damage to colon tissues and higher expression levels of IL-18 and NF-κB p65 in colon tissues(P<0.01 for both).Compared with the CD group,the HM group showed significantly lower levels of these proteins(PIL-18<0.01 and Pp65<0.05).There were no significant differences in the expression of TNF-αprotein in colon tissue among the rat groups.Typical autophagic vesicles were found in both the CD and HM groups.The expression of the autophagy proteins LC3B and Beclin-1 was upregulated(P<0.01 for both)in the colon tissues of rats in the CD group compared with the NC group,while the protein expression of p62 and p-mTOR was downregulated(P<0.01 for both).However,these expression trends were significantly reversed in the HM group compared with the CD group(PLC3B<0.01,PBeclin-1<0.05,Pp62<0.05,and Pm-TOR<0.05).Compared with those in the RA+CD group,the mRNA expression levels of PI3KC1,Akt1,mTOR,and p62 in the RA+HM group were significantly higher(PPI3KC1<0.01 and PAkt1,mTOR,and p62<0.05),while those of LC3B were significantly lower(P<0.05).Compared with the RA+CD group,the RA+HM group exhibited significantly higher PI3KC1,p-Akt1,and pmTOR protein levels(PPI3KC1<0.01,Pp-Akt1<0.05,and Pp-mTOR<0.01),a higher p62 protein level(P=0.057),and significantly lower LC3B and Vps34 protein levels(P<0.01 for both)in colon tissue.CONCLUSION HM can activate PI3KC1/Akt1/mTOR signaling while inhibiting the PI3KC3(Vps34)-Beclin-1 protein complex in the colon tissues of CD rats,thereby inhibiting overactivated autophagy and thus exerting a therapeutic effect.

Phosphatidylinositol 3-kinase CB association with preoperative radiotherapy response in rectal adenocarcinoma

AIM:To examine the correlation of phosphatidylinositol3-kinase(PIK3)CB expression with preoperative radiotherapy response in patients with stageⅡ/Ⅲrectal adenocarcinoma.METHODS:PIK3CB immunoexpression was retrospectively assessed in pretreatment biopsies from 208 patients with clinical stageⅡ/Ⅲrectal adenocarcinoma,who underwent radical surgery after 30-Gy/10-fractionpreoperative radiotherapy.The relation between PIK3CB expression and tumor regression grade,clinicopathological characteristics,and survival time was statistically analyzed.Western blotting and in vitro clonogenic formation assay were used to detect PIK3CB expression in four colorectal cancer cell lines(HCT116,HT29,Lo Vo,and LS174T)treated with 6-Gy ionizing radiation.Pharmacological assays were used to evaluate the therapeutic relevance of TGX-221(a PIK3CB-specific inhibitor)in the four colorectal cancer cell lines.RESULTS:Immunohistochemical staining indicated that PIK3CB was more abundant in rectal adenocarcinoma tissues with poor response to preoperative radiotherapy.High expression of PIK3CB was closely correlated with tumor height(P<0.05),yp T stage(P<0.05),and high-degree tumor regression grade(P<0.001).High expression of PIK3CB was a potential prognostic factor for local recurrence-free survival(P<0.05)and metastasis-free survival(P<0.05).High expression of PIK3CB was also associated with poor therapeutic response and adverse outcomes in rectal adenocarcinoma patients treated with 30-Gy/10-fraction preoperative radiotherapy.In vitro,PIK3CB expression was upregulated in all four colorectal cancer cell lines concurrently treated with 6-Gy ionizing radiation,and the PIK3CB-specific inhibitor TGX-221 effectively inhibited the clonogenic formation of these four colorectal cancer cell lines.CONCLUSION:PIK3CB is critically involved in response to preoperative radiotherapy and may serve as a novel target for therapeutic intervention.

Protective effects of panax notoginseng saponin on dextran sulfate sodium-induced colitis in rats through phosphoinositide-3-kinase protein kinase B signaling pathway inhibition

BACKGROUND Intestinal inflammation is a common digestive tract disease, which is usually treated with hormone medicines. Hormone medicines are effective to some extent, but long-term use of them may bring about many complications.AIM To explore the protective effects of panax notoginseng saponin(PNS) against dextran sulfate sodium(DSS)-induced intestinal inflammatory injury through phosphoinositide-3-kinase protein kinase B(PI3K/AKT) signaling pathway inhibition in rats.METHODS Colitis rat models were generated via DSS induction, and rats were divided into control(no modeling), DSS, DSS + PNS 50 mg/k, and DSS + PNS 100 mg/kg groups. Then, the intestinal injury, oxidative stress parameters, inflammatory indices, tight junction proteins, apoptosis, macrophage polarization, and TLR4/AKT signaling pathway in colon tissues from rats in each of the groups were detected. The PI3 K/AKT signaling pathway in the colon tissue of rats was blocked using the PI3K/AKT signaling pathway inhibitor, LY294002.RESULTS Compared with rats in the control group, rats in the DSS group showed significantly shortened colon lengths, and significantly increased disease activity indices, oxidative stress reactions and inflammatory indices, as well as significantly decreased expression of tight junction-associated proteins. In addition, the DSS group showed significantly increased apoptotic cell numbers,and showed significantly increased M1 macrophages in spleen and colon tissues.They also showed significantly decreased M2 macrophages in colon tissues, as well as activation of the PI3K/AKT signaling pathway(all P < 0.05). Compared with rats in the DSS group, rats in the DSS + PNS group showed significantly lengthened colon lengths, decreased disease activity indices, and significantly alleviated oxidative stress reactions and inflammatory responses. In addition, this group showed significantly increased expression of tight junction-associated proteins, significantly decreased apoptotic cell numbers, and significantly decreased M1 macrophages in spleen and colon tissues. This group further showed significantly increased M2 macrophages in colon tissues, and significantly suppressed activation of the PI3K/AKT signaling pathway, as well as a dose dependency(all P < 0.05). When the PI3K/AKT signaling pathway was inhibited, the apoptosis rate of colon tissue cells in the DSS + LY294002 group was significantly lower than that of the DSS group(P < 0.05).CONCLUSION PNS can protect rats against DSS-induced intestinal inflammatory injury by inhibiting the PI3K/AKT signaling pathway, and therefore may be potentially used in the future as a drug for colitis.

Analysis of Phosphatidylinositol 3-kinase Activation in the Adipose Tissue of Gestational Diabetes Mellitus Patients and Insulin Resistance

The P85 regulatory subunit protein and gene expression and P110 catalylic subunit activity of phosphatidylinositol 3-kinase (PI-3K) were investigated in adipose tissue of patients with gestational diabetes mellitus (GDM) in order to explore the molecular mechanisms of insulin resistance (IR) of GDM. Samples from patients with GDM (n=50), and controls (n=50) were collected. Fasting insulin (FIN) was determined by radioimmunoassay. Fasting plasma glucose (FPG) was measured by oxidase assay. Western blot technique was used to detect the levels of PI-3K P85 subunit in adipose tissues of patients with GDM. The mRNA expression of PI-3K P85 subunit was detected by reverse transcription polymerase chain reaction (RT-PCR) method in the adipose tissue. PI-3K activity was examined by immunoprecipitation, thin-layer chromatography and gamma scintillation counting. The results were analyzed statistically. It was found that the levels of FPG, FIN and HOMA-IR in GDM group were significantly higher than those in control group (all P0.05). PI-3K activity was significantly decreased to 82.89% in GDM group as compared with control group (P<0.01) and negatively correlated with HOMA-IR (r=-0.75, P<0.01). It was concluded that PI-3K in GDM patients may be involved in the insulin signaling pathway, resulting in IR of GDM.

Micro RNA-21 promotes phosphatase gene and protein kinase B/phosphatidylinositol 3-kinase expression in colorectal cancer

AIM: To explore the regulatory mechanism of the target gene of micro RNA-21(mi R-21), phosphatase gene(p TEN), and its downstream proteins, protein kinase B(AKT) and phosphatidylinositol 3-kinase(p I3K), in colorectal cancer(CRC) cells. METHODS: Quantitative real-time p CR(q RT-p CR) and Western blot were used to detect the expression levels of mi R-21 and p TEN in HCT116, HT29, Colo32 and SW480 CRC cell lines. Also, the expression levels of p TEN m RNA and its downstream proteins AKT and p I3 K in HCT116 cells after downregulating mi R-21 were investigated. RESULTS: Comparing the mi R-21 expression in CRC cells, the expression levels of mi R-21 were highest in HCT116 cells, and the expression levels of mi R-21 were lowest in SW480 cells. In comparing mi R-21 and p TEN expression in CRC cells, we found that the protein expression levels of mi R-21 and p TEN were inversely correlated(p < 0.05); when mi R-21 expression was reduced, m RNA expression levels of p TEN did not significantly change(p > 0.05), but the expression levels of its protein significantly increased(p < 0.05). In comparing the levels of p TEN protein and downstream AKT and p I3 K in HCT116 cells after downregulation of mi R-21 expression, the levels of AKT and p I3 K protein expression significantly decreased(p < 0.05). CONCLUSION: p TEN is one of the direct target genesof mi R-21. Thus, phosphatase gene and its downstream AKT and p I3 K expression levels can be regulated by regulating the expression levels of mi R-21, which in turn regulates the development of CRC.

Cytotoxicity of nonylphenol on spermatogonial stem cells via phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin pathway

BACKGROUND With continuous advancement of industrial society,environmental pollution has become more and more serious.There has been an increase in infertility caused by environmental factors.Nonylphenol(NP)is a stable degradation product widely used in daily life and production and has been proven to affect male fertility.However,the underlying mechanisms therein are unclear.Thus,it is necessary to study the effect and mechanism of NP on spermatogonial stem cells(SSCs).AIM To investigate the cytotoxic effect of NP on SSCs via the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR)pathway.METHODS SSCs were treated with NP at 0,10,20 or 30μmol.MTT assay was performed to evaluate the effect of NP on the proliferation of SSCs.Flow cytometry was conducted to measure SSC apoptosis.The expression of Bad,Bcl-2,cytochrome-c,pro-Caspase 9,SOX-2,OCT-4,Nanog,Nanos3,Stra8,Scp3,GFRα1,CD90,VASA,Nanos2,KIT,PLZF and PI3K/AKT/mTOR-related proteins was observed by western blot,and the mRNA expression of SOX-2,OCT-4 and Nanog was detected by quantitative reverse transcription polymerase chain reaction.RESULTS Compared with untreated cells(0μmol NP),SSCs treated with NP at all concentrations showed a decrease in cell proliferation and expression of Bcl-2,Nanog,OCT-4,SOX-2,Nanos3,Stra8,Scp3,GFRα1,CD90,VASA,Nanos2,KIT,and PLZF(P<0.05),whereas the expression of Bad,cytochrome-c,and pro-Caspase 9 increased significantly(P<0.05).We further examined the PI3K/AKT/mTOR pathway and found that the phosphorylation of PI3K,AKT,mTORC1,and S6K was significantly decreased by NP at all concentrations compared to that in untreated SSCs(P<0.05).NP exerted the greatest effect at 30μmol among all NP concentrations.CONCLUSION NP attenuated the proliferation,differentiation and stemness maintenance of SSCs while promoting apoptosis and oxidative stress.The associated mechanism may be related to the PI3K/AKT/mTOR pathway.

Promoting axon regeneration in the central nervous system by increasing PI3-kinase signaling

Much research has focused on the PI3-kinase and PTEN signaling pathway with the aim to stimulate repair of the injured central nervous system.Axons in the central nervous system fail to regenerate,meaning that injuries or diseases that cause loss of axonal connectivity have life-changing consequences.In 2008,genetic deletion of PTEN was identified as a means of stimulating robust regeneration in the optic nerve.PTEN is a phosphatase that opposes the actions of PI3-kinase,a family of enzymes that function to generate the membrane phospholipid PIP_(3) from PIP_(2)(phosphatidylinositol(3,4,5)-trisphosphate from phosphatidylinositol(4,5)-bisphosphate).Deletion of PTEN therefore allows elevated signaling downstream of PI3-kinase,and was initially demonstrated to promote axon regeneration by signaling through mTOR.More recently,additional mechanisms have been identified that contribute to the neuron-intrinsic control of regenerative ability.This review describes neuronal signaling pathways downstream of PI3-kinase and PIP3,and considers them in relation to both developmental and regenerative axon growth.We briefly discuss the key neuron-intrinsic mechanisms that govern regenerative ability,and describe how these are affected by signaling through PI3-kinase.We highlight the recent finding of a developmental decline in the generation of PIP_(3) as a key reason for regenerative failure,and summarize the studies that target an increase in signaling downstream of PI3-kinase to facilitate regeneration in the adult central nervous system.Finally,we discuss obstacles that remain to be overcome in order to generate a robust strategy for repairing the injured central nervous system through manipulation of PI3-kinase signaling.

Xihuang pills induce apoptosis in hepatocellular carcinoma by suppressing phosphoinositide 3-kinase/protein kinase- B/mechanistic target of rapamycin pathway

BACKGROUND The phosphoinositide 3-kinase/protein kinase-B/mechanistic target of rapamycin(PI3K/Akt/mTOR) signalling pathway is crucial for cell survival, differentiation, apoptosis and metabolism. Xihuang pills(XHP) are a traditional Chinese preparation with antitumour properties. They inhibit the growth of breast cancer, glioma, and other tumours by regulating the PI3K/Akt/mTOR signalling pathway. However, the effects and mechanisms of action of XHP in hepatocellular carcinoma(HCC) remain unclear. Regulation of the PI3K/Akt/mTOR signalling pathway effectively inhibits the progression of HCC. However, no study has focused on the XHPassociated PI3K/Akt/mTOR signalling pathway. Therefore, we hypothesized that XHP might play a role in inhibiting HCC through the PI3K/Akt/mTOR signalling pathway.AIM To confirm the effect of XHP on HCC and the possible mechanisms involved.METHODS The chemical constituents and active components of XHP were analysed using ultra-performance liquid chromatography-quadrupole time of flight mass spectrometry(UPLC-Q-TOF-MS). Cellbased experiments and in vivo xenograft tumour experiments were utilized to evaluate the effect of XHP on HCC tumorigenesis. First, SMMC-7721 cells were incubated with different concentrations of XHP(0, 0.3125, 0.625, 1.25, and 2.5 mg/mL) for 12 h, 24 h and 48 h. Cell viability was assessed using the CCK-8 assay, followed by an assessment of cell migration using a wound healing assay.Second, the effect of XHP on the apoptosis of SMMC-7721 cells was evaluated. SMMC-7721 cells were stained with fluorescein isothiocyanate and annexin V/propidium iodide. The number of apoptotic cells and cell cycle distribution were measured using flow cytometry. The cleaved protein and mRNA expression levels of caspase-3 and caspase-9 were detected using Western blotting and quantitative reverse-transcription polymerase chain reaction(RT-qPCR), respectively.Third, Western blotting and RT–qPCR were performed to confirm the effects of XHP on the protein and mRNA expression of components of the PI3K/Akt/mTOR signalling pathway.Finally, the effects of XHP on the tumorigenesis of subcutaneous hepatocellular tumours in nude mice were assessed.RESULTS The following 12 compounds were identified in XHP using high-resolution mass spectrometry:Valine, 4-gingerol, myrrhone, ricinoleic acid, glycocholic acid, curzerenone, 11-keto-β-boswellic acid, oleic acid, germacrone, 3-acetyl-9,11-dehydro-β-boswellic acid, 5β-androstane-3,17-dione, and 3-acetyl-11-keto-β-boswellic acid. The cell viability assay results showed that treatment with 0.625mg/mL XHP extract decreased HCC cell viability after 12 h, and the effects were dose-and timedependent. The results of the cell scratch assay showed that the migration of HCC cells was significantly inhibited in a time-dependent manner by the administration of XHP extract(0.625mg/mL). Moreover, XHP significantly inhibited cell migration and resulted in cell cycle arrest and apoptosis. Furthermore, XHP downregulated the PI3K/Akt/mTOR signalling pathway, which activated apoptosis executioner proteins(e.g., caspase-9 and caspase-3). The inhibitory effects of XHP on HCC cell growth were determined in vivo by analysing the tumour xenograft volumes and weights.CONCLUSION XHP inhibited HCC cell growth and migration by stimulating apoptosis via the downregulation of the PI3K/Akt/mTOR signalling pathway, followed by the activation of caspase-9 and caspase-3.Our findings clarified that the antitumour effects of XHP on HCC cells are mediated by the PI3K/Akt/mTOR signalling pathway, revealing that XHP may be a potential complementary therapy for HCC.

Phosphoinositide 3-kinase dependent modulation of morphine versus cocaine dependence involves activation of nischarin

OBJECTIVE Phosphoinositide 3-kinase(PI3K) activation was reported to participate in the development of effect of some drugs,such as morphine and cocaine dependence.We previous found nischarin is associated with the activation of PI3K.It is our great interest to investigate the involvement of nischarin in PI3K dependent modulation of morphine versus cocaine dependence.METHODS In order to study the role of nischarin in drug dependence and tolerance,nischarin knockout mice were used for our research.Effect of psychological dependence was studied by conditioned place preference(CPP),and the effect of physical dependence was tested by naloxone-precipitated withdrawal signs.Some brain tissues were harvested 24 h after the behavioral experiment for the further measurement.RESULTS PI3K specific inhibitor LY294002 significantly blocked the acquisition of morphine-induced CPP in wild-type mice,but had no effect on its expression.In comparison,LY294002 failed to block the acquisition of cocaine-induced CPP but inhibited the expression.Furthermore,we found naloxoneprecipitated withdrawal signs in the morphine dependent mice was inhibited by LY294002.Nischarin knockout in mice could abolish the effect of LY294002 on blocking the effects of morphine,but had no effect on cocaine.CONCLUSION PI3K activation is involved in the different phases of morphine and cocaine dependence,and nischarin plays an important role in the process.

Phosphoinositide-3-kinase regulatory subunit 4 participates in the occurrence and development of amyotrophic lateral sclerosis by regulating autophagy

The development of amyotrophic lateral sclerosis(ALS)may be related to the abnormal alterations of multiple proteins.Our previous study revealed that the expression of phosphoinositide-3-kinase regulatory subunit 4(PIK3R4)was decreased in ALS.However,the role of PIK3R4 in ALS pathogenesis remains unknown.This study was the first to find that transfection of PC12 cells with small interfering RNA against the PIK3R4 gene significantly decreased the expression levels of PIK3R4 and the autophagy-related proteins p62 and LC3.Additionally,in vivo experiments revealed that the PIK3R4 protein was extensively expressed in the anterior horn,posterior horn,central canal,and areas surrounding the central canal in cervical,thoracic,and lumbar segments of the spinal cord in adult mice.PIK3R4 protein was mainly expressed in the neurons within the spinal lumbar segments.PIK3R4 and p62 expression levels were significantly decreased at both the pre-onset and onset stages of ALS disease in Tg(SOD1*G93A)1 Gur mice compared with control mice,but these proteins were markedly increased at the progression stage.LC3 protein expression did not change during progression of ALS.These findings suggest that PIK3R4 likely participates in the prevention of ALS progression.This study was approved by the Ethics Committee for Animal Care and Use of Jiangxi Provincial People’s Hospital,Affiliated People’s Hospital of Nanchang University(approval No.2020025)on March 26,2020.

The cardioprotection induced by lipopolysaccharide involves phosphoinositide 3-kinase/Akt and high mobility group box 1 pathways

Objective： The mechanisms by which lipopolysaccharide （LPS） pretreatment induces cardioprotection following ischaemia/reperfusion （I/R） have not been fully elucidated. We hypothesized that activation of phosphoinositide 3-kinase （PI3K）/Akt and high mobility group box 1 （HMGBxl） signaling plays an important role in LPS-induced cardioprotection. Methods： In in vivo experiments, age- and weight- matched male C57BL/10Sc wild type mice were pretreated with LPS before ligation of the left anterior descending coronary followed by reperfusion. Infarction size was examined by triphenyltetrazolium chloride （TTC） staining. Akt, phospho-Akt, and HMGBxl were assessed by immunoblotting with appropriate primary antibodies. In situ cardiac myocyte apop- tosis was examined by the TdT-mediated dUTP nick-end labeling （TUNEL） assay. In an in vitro study, rat cardiac myoblasts （H9c2） were subdivided into two groups, and only one was pretreated with LPS. After pretreatment, the cells were transferred into a hypoxic chamber under 0.5% 02. Levels of HMGBxl were assessed by immunoblot. Results： In the in vivo experiment, pretreatment with LPS reduced the at risk infarct size by 70.6% and the left ventricle infarct size by 64.93% respectively. Pretreatment with LPS also reduced cardiac myocytes apoptosis by 39.1% after ischemia and reperfusion. The mechanisms of LPS induced cardioprotection involved increasing PI3K/Akt activity and decreasing expression of HMGBxl. In the in vitro study, pretreatment with LPS reduced the level of HMGBxl in H9c2 cell cytoplasm following hypoxia. Conclusion： The results suggest that the cardioprotection following I/R induced by LPS pretreatment involves PI3K/Akt and HMGBxl pathways.

Leptin Regulated Insulin Secretion via Stimulating IRS2-associated Phosphoinositide 3-kinase Activity in the isolated Rat Pancreatic Islets

To investigate the molecular mechanism of leptin regulating insulin secretion through determining the regulation of insulin secretion and the insulin receptor substrate (IRS)-2-associated phosphoinositide 3-kinase (PI3K) activity by leptin in the isolated rat pancreatic islets, pancreatic islets were isolated from male SD rats by the collagenase method. The purified islets were incubated with leptin 2 nmol/L for 1 h in the presence of 5.6 mmol/L or 11.1 mmol/L glucose. Insulin release was measured using radioimmunoassay. IRS-2-associated activity of PI3K was determined by immunoprecipitate assay and Western blot. The results showed that in the presence of 5.6 mmol/L glucose, leptin had no significant effect on both insulin secretion and IRS-2-associated PI3K activity, but in the presence of 11.1 mmol/L glucose, insulin release was significantly inhibited after the islets were exposed to leptin for 1 h (P<0.01). PI3K inhibitor wortmannin blocked the inhibitory regulation of leptin on insulin release (P<0.05). Western Blot assay revealed that 2 nmol/L leptin could significantly increase the IRS-2-associated activity of PI3K by 51.5 % (P<0.05) in the presence of 11.1 mmol/L glucose. It was concluded that Leptin could significantly inhibit insulin secretion in the presence of 11.1 mmol/L glucose by stimulating IRS-2-associated activity of PI3K, which might be the molecular mechanism of leptin regulating insulin secretion.

Anti-silencing function 1B knockdown suppresses the malignant phenotype of colorectal cancer by inactivating the phosphatidylinositol 3-kinase/AKT pathway

BACKGROUND Mounting studies have highlighted the pivotal influence of anti-silencing function 1B(ASF1B)on the malignancy of cancers.AIM To explore the influence and mechanism of ASF1B in colorectal cancer(CRC).METHODS Quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect mRNA expression of ASF1B.Immunohistochemical staining was performed to detect protein expression of ASF1B and Ki67 in tumor tissues.Western blot analysis was used to determine levels of ASF1B and proliferation/epithelial mesenchymal transition(EMT)/stemness-related proteins.In addition,the proliferation of CRC cells was assessed using Cell Counting Kit-8 and 5-Ethynyl-2’-Deoxyuridine assays.The migration and invasion of CRC cells were evaluated using transwell assays.Stemness of CRC cells was tested using the sphere formation assay.To construct a xenograft tumor model,HCT116 cells were introduced into mouse flanks via subcutaneous injection.RESULTS ASF1B expression was markedly increased in CRC tissues and cells,and it was inversely correlated with overall survival of CRC patients and was positively associated with the tumor node metastasis(TNM)stage of CRC patients.Silencing of ASF1B suppressed proliferation,migration,invasion,stemness and EMT of CRC cells as well as tumorigenesis of xenograft mice.Furthermore,protein levels of Pphosphatidylinositol 3-kinase(p-PI3K)and p-AKT were decreased after silencing of ASF1B in CRC cells.The inhibitory effects of ASF1B knockdown on cell proliferation,stemness and EMT were partly abolished by PI3K activator in CRC cells.CONCLUSION Silencing of ASF1B inactivated the PI3K/AKT pathway to suppress CRC malignancy in vitro.

Telencephalin protects PAJU cells from amyloid beta protein-induced apoptosis by activating the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway

Telencephalin is a neural glycoprotein that reduces apoptosis induced by amyloid beta protein in the human neural tumor cell line PAJU. In this study, we examined the role of the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway in this process. Western blot analysis demonstrated that telencephalin, phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B were not expressed in PAJU cells transfected with empty plasmid, while they were expressed in PAJU cells transfected with a telencephalin expression plasmid. After treatment with 1.0 nM amyloid beta protein 42, expression of telencephalin and phosphorylated phosphatidylinositol-3-kinase/protein kinase B in the transfected cells gradually diminished, while levels of phosphorylated ezrin/radixin/moesin increased. In addition, the high levels of telencephalin, phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B expression in PAJU cells transfected with a telencephalin expression plasmid could be suppressed by the phosphatidylinositol-3-kinase inhibitor LY294002. These findings indicate that telencephalin activates the ezrin/radixin/moesin family/phosphatidylinositol-3-kinase/protein kinase B pathway and protects PAJU cells from amyloid beta protein-induced apoptosis.

Response of Subcutaneous Xenografts of Endometrial Cancer in Nude Mice to Inhibitors of Phosphatidylinositol 3-Kinase/Akt and Mitogen-Activated Protein Kinase (MAPK) Pathways: An Effective Therapeutic Strategy for Endometrial Cancer

Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.

Tumor-related factor complement Clq/TNF-related protein 6 affects the development of digestive system tumors through the phosphatidylinositol 3-kinase pathway

In this editorial,we review the work of Razali et al published in World J Gas-troenterology,with a particular focus on the effect of rs10889677 variation in the phosphatidylinositol 3-kinase(PI3K)pathway and buparlisib on colitis-associated cancer.The role of PI3K in promoting cancer progression has been widely recognized,as it is involved in regulating the survival,differentiation,and prolif-eration of cancer cells.The complement Clq/TNF-related protein 6(CTRP6)is a newer tumor-associated factor.Recent studies have revealed the pro-tumor effect of CTRP6 in gastric cancer,hepatocellular carcinoma,colorectal cancer,and other gastrointestinal tumors through the PI3K pathway.This article attempts to reveal the mechanism through which the CTRP6 affects the development of digestive system tumors through the PI3K pathway by summarizing recent research.