Surface chemistry induces mitochondria-mediated apoptosis of breast cancer cells via PTEN/PI3K/AKT signaling pathway

Tumor cell can be significantly influenced by various chemical groups of the extracellular matrix proteins. However, the underlying molecular mechanisms involved in the interaction between cancer cells and functional groups in the extracellular matrix remain unknown. Using chemically modified surfaces with biological functional groups (CH₃, NH₂, OH), it was found that hydrophobic surfaces modified with CH₃ and NH₂ suppressed cell proliferation and induced the number of apoptotic cells. Mitochondrial dysfunction, cytochrome c release, Bax upregulation, cleaved caspase-3 and PARP, and Bcl-2 downregulation indicated that hydrophobic surfaces with CH₃ and NH₂ triggered the activation of intrinsic apoptotic signaling pathway. Cells on the CH₃- and NH₂-modified hydrophobic surfaces showed downregulated expression and activation of integrin β1, with a subsequent decrease of focal adhesion kinase (FAK) activity. The RhoA/ROCK/PTEN signaling was then activated to inhibit the phosphorylation of PI3K and AKT, which are essential for cell proliferation. However, pretreatment of MDA-MB-231 cells with SF1670, a PTEN inhibitor, abolished the hydrophobic surface-induced activation of the intrinsic pathway. Taken together, the present results indicate that CH₃- and NH₂-modified hydrophobic surfaces induce mitochondria-mediated apoptosis by suppressing the PTEN/PI3K/AKT pathway, but not OH surfaces. These findings are helpful to understand the interaction between extracellular matrix and cancer cells, which might provide new insights into the mechanism potential intervention strategies for tumor prognosis.     

Retracted: Nimotuzuma restrains proliferation and induces apoptosis in human osteosarcoma cells by regulation of EGFR/PI3K/AKT signal pathway

Osteosarcoma (OS) is a conversant malignant bone tumor, commonly occurs in children and adolescents. Nimotuzuma is an epidermal growth factor receptor (EGRF) monoclonal antibody agent, which has been exploited in varied solid tumors. Nevertheless, the functions of Nimotuzuma in OS remain blurry. We attempted to disclose the impacts of Nimotuzuma on OS cells proliferation and apoptosis. OS MG-63 and U2OS cells were stimulated with the disparate doses of Nimotuzuma. Then, cell viability, cell cycle, and apoptosis were appraised through executing CCK-8 and flow cytometry assays. Moreover, the change of mitochondrial membrane potential (ΔΨm) was estimated via JC-1 fluorescent probe to further probe the impacts of Nimotuzuma on cell apoptosis. The proteins of cell apoptosis, cell cycle, and EGFR/PI3K/AKT were appraised via western blot. Eventually, Nimotuzuma together EGRF or PI3K inhibitor (LY294002) were utilized to dispose MG-63 to further uncover the latent mechanism. We found that Nimotuzuma remarkably repressed cell viability at a time- and dose-dependent manners in MG-63 and U2OS cells. The percentage of the S phase cells was evidently reduced by Nimotuzuma through regulating P21, Cyclin E1, and Cyclin D1. In addition, Nimotuzuma obviously evoked cell apoptosis, meanwhile elevated Bid, Bax, and cleaved-caspase-3. Further exploration showed that Nimotuzuma decreased ΔΨm in a dose-dependent manner in MG-63 and U2OS cells. Besides, we discovered the repressive functions of Nimotuzuma in OS cells proliferation and apoptosis via hindering the EGFR/PI3K/AKT pathway. These investigations testified that Nimotuzuma repressed cell growth by restraining the EGFR/PI3K/AKT pathway in OS cells, hinting the antitumor activity of Nimotuzuma in OS.     

高浓度七氟醚通过抑制VEGF/PI3K/AKT信号通路诱导神经干细胞凋亡的研究

目的探讨妊娠中期的七氟醚暴露对神经干细胞凋亡过程的影响和作用机制。 方法将孕中期大鼠随机分为3组,每组48只孕鼠：对照组,低浓度七氟醚组,高浓度七氟醚组。在妊娠第14天,以2﹪或3.5﹪七氟醚麻醉怀孕大鼠2?h。通过免疫荧光检查神经干细胞凋亡,收集麻醉后6、24和48?h以及出生后第0天（P?0）,第14天（P?14）和第28天（P?28）的脑组织进行Nestin-TUNEL免疫荧光双标染色以及Nestin、血管内皮生长因子（VEGF）和磷酸肌醇3-激酶（PI3K）AKT通路相关蛋白的免疫印迹检测。采用单因素方差分析和Bonferroni事后检验进行统计学分析。 结果麻醉后6、24和48?h以及P?0,P?14和P?28,脑组织中Nestin和TUNEL阳性细胞的百分比增加[6?h：对照组0.91±0.07,低浓度组1.01±0.08,高浓度组2.62±0.21（F?=?399,P?相似文献   

Dieckol exerts anticancer activity in human osteosarcoma (MG-63) cells through the inhibition of PI3K/AKT/mTOR signaling pathway

BackgroundOsteosarcoma (OS) is the most common malignant bone cancer with more metastasis and increased occurrence in children and teen-agers and being responsible for more number of morbidity and mortality worldwide.ObjectiveThe current exploration was planned study the in vitro anticancer actions of dieckol against human OS MG-63 cells via PI3K/AKT/mTOR signaling inhibition.MethodologyThe cytotoxicity of dieckol was scrutinized by MTT assay. Effects of dieckol on the ROS accumulation, apoptotic cell death, and MMP level in the MG-63 cells were studied by respective fluorescence staining assays. The levels of proliferative, inflammatory, and apoptotic markers in the dieckol treated MG-63 cells were scrutinized by marker specific kits. The expressions of PI3K, AKT, and mTOR was assayed by RT-PCR.ResultsThe MTT assay revealed that the dieckol dose dependently prevented MG-63 cells viability and the IC50 was found at 15 µM. Dieckol treatment effectively reduced the MMP level and improved the ROS generation and apoptosis in MG-63 cells. Dieckol also regulated the proliferative (cyclin D1), inflammatory (COX-2, IL-6, TNF-α, and NF-κB), and apoptotic (caspase-3, Bax, Bcl-2) markers in the MG-63 cells. The PI3K/AKT/mTOR signaling in the MG-63 cells were effectively inhibited by the dieckol treatment.ConclusionIn conclusion, our findings from this study recommends that the dieckol could be a talented anticancer candidate for the OS management in the future.     

SLC1A3 promotes gastric cancer progression via the PI3K/AKT signalling pathway

Gastric cancer is a major cause of mortality worldwide. The glutamate/aspartate transporter SLC1A3 has been implicated in tumour metabolism and progression, but the roles of SLC1A3 in gastric cancer remain unclear. We used bioinformatics approaches to analyse the expression of SLC1A3 and its role in gastric cancer. The expression levels of SLC1A3 were examined using RT‐qPCR and Western bolting. SLC1A3 overexpressing and knock‐down cell lines were constructed, and the cell viability was evaluated. Glucose consumption, lactate excretion and ATP levels were determined. The roles of SLC1A3 in tumour growth were evaluated using a xenograft tumour growth model. SLC1A3 was found to be overexpressed in gastric cancer, and this overexpression was associated with poor prognosis. In vitro and in vivo assays showed that SLC1A3 affected glucose metabolism and promoted gastric cancer growth. GSEA analysis suggested that SLC1A3 was positively associated with the up‐regulation of the PI3K/AKT pathway. SLC1A3 overexpression activated the PI3K/AKT pathway and up‐regulated GLUT1, HK II and LDHA expression. The PI3K/AKT inhibitor LY294002 prevented SLC1A3‐induced glucose metabolism and cell proliferation. Our findings indicate that SLC1A3 promotes gastric cancer progression via the PI3K/AKT signalling pathway. SLC1A3 is therefore a potential therapeutic target in gastric cancer.     

GHR is involved in gastric cell growth and apoptosis via PI3K/AKT signalling

Growth hormone receptor (GHR), the cognate receptor of growth hormone (GH), is a membrane bound receptor that belongs to the class I cytokine receptor superfamily. GH binding GHR induces cell differentiation and maturation, initiates the anabolism inside the cells and promotes cell proliferation. Recently, GHR has been reported to be associated with various types of cancer. However, the underlying mechanism of GHR in gastric cancer has not been defined. Our results showed that silence of GHR inhibited the growth of SGC-7901 and MGC-803 cells, and tumour development in mouse xenograft model. Flow cytometry showed that GHR knockout significantly stimulated gastric cancer cell apoptosis and caused G1 cell cycle arrest, which was also verified by Western blot that GHR deficiency induced the protein level of cleaved-PARP, a valuable marker of apoptosis. In addition, GHR deficiency inhibited the activation of PI3K/AKT signalling pathway. On the basis of the results, that GHR regulates gastric cancer cell growth and apoptosis through controlling G1 cell cycle progression via mediating PI3K/AKT signalling pathway. These findings provide a novel understanding for the role of GHR in gastric cancer.     

Effects of streptozotocin-induced type 1 maternal diabetes on PI3K/AKT signaling pathway in the hippocampus of rat neonates

Diabetes in pregnancy impairs hippocampus development in offspring, leading to behavioral problems and learning deficits. Phosphatidylinositol 3-kinase/protein kinase B (PKB/Akt) signaling pathway plays a pivotal role in the regulation of neuronal proliferation, survival and death. The present study was designed to examine the effects of maternal diabetes on PKB/Akt expression and phosphorylation in the developing rat hippocampus. Wistar female rats were maintained diabetic from a week before pregnancy through parturition and male offspring was killed at first postnatal day (P1). The hippocampal expression and phosphorylation level of PKB/Akt, one of the key molecules in PI3K/AKT signaling pathway, was evaluated using real-time polymerase chain reaction (PCR) and western blot analysis. We found a significant bilateral downregulation of AKT1 gene expression in the hippocampus of pups born to diabetic mothers (p?<?0.05). Interestingly, our results revealed a marked upregulation of Akt1 gene in insulin-treated group compared with other groups (p?<?0.05). The western blot analysis also showed the reduction of phosphorylation level of all AKT isoforms in both diabetic and insulin-treated groups compared with control (p?<?0.05). Moreover, the results showed a significant increase in phosphorylation level of AKT in insulin-treated group compared with the diabetic group. These results represent that diabetes during pregnancy strongly influences the regulation of PKB/AKT in the developing rat hippocampus. Furthermore, although the control of glycemia by insulin administration is not sufficient to prevent the alterations in PKB/Akt expression, it modulates the phosphorylation process, thus ultimately resulting in a situation comparable to that found in the normal condition.     

Mollugin induces tumor cell apoptosis and autophagy via the PI3K/AKT/mTOR/p70S6K and ERK signaling pathways

Mollugin, a bioactive phytochemical isolated from Rubia cordifolia L., has shown preclinical anticancer efficacy in various cancer models. However the effects of mollugin in regulating cancer cell survival and death remains undefined. In the present study we found that mollugin exhibited cytotoxicity on various cancer models. The suppression of cell viability was due to the induction of mitochondria apoptosis. In addition, the presence of autophagic hallmarks was observed in mollugin-treated cells. Notably, blockade of autophagy by a chemical inhibitor or RNA interference enhanced the cytotoxicity of mollugin. Further experiments demonstrated that phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin/p70S6 kinase (PI3K/AKT/mTOR/p70S6K) and extracellular regulated protein kinases (ERK) signaling pathways participated in mollugin-induced autophagy and apoptosis. Together, these findings support further studies of mollugin as candidate for treatment of human cancer cells.     

Celecoxib, a cyclooxygenase-2 inhibitor, induces apoptosis in human osteosarcoma cell line MG-63 via down-regulation of PI3K/Akt

Cyclooxygenase-2 (COX-2), involved in the inhibition of apoptosis and, the potentiation of cell growth, is frequently overexpressed in human malignancies including osteosarcoma (OS). We have attempted to identify the anti-proliferation of celecoxib, a selective COX-2 inhibitor, and the combination of celecoxib and cisplatin in MG-63 cells, and to explore the potential molecular mechanisms involved. MG-63 cells were treated with the combination of celecoxib and cisplatin or either agent alone for 48h in serum-supplemented medium. Celecoxib caused G1 phase arrest and significantly inhibited cell growth, as well as potentiating cisplatin-induced apoptosis. The effect was dose-dependent, and apoptotic changes such as DNA fragments and apoptotic bodies were observed. However, downregulation of COX-2 did not occur in cells treated with celecoxib. Phosphoinositide-3-kinase (PI3K)/Akt, survivin, bcl-2 were significantly downregulated in cells treated with the combination of celecoxib and cisplatin, and decreased survivin and bcl-2 levels were found in cells with wortmannin, a specific PI3K inhibitor. Moreover, the decreased expressions of procaspase-9, procaspase-3 and cleaved PARP-1 were detected by Western blot analysis. Therefore, celecoxib exerts its anti-tumor activities through COX-2-independent mechanisms, which may be PI3K/Akt-dependent, and survivin and bcl-2-related. PI3K may be at the center of the celecoxib effects, which play an essential role in the regulation of survivin and Bcl-2.     

RNF7 promotes glioma growth via the PI3K/AKT signalling axis

RNF7 has been reported to play critical roles in various cancers. However, the underlying mechanisms of RNF7 in glioma development remain largely unknown. Herein, the expression level of RNF7 was examined in tissues by quantitative real-time PCR, Western blotting and immunohistochemistry. The effect of RNF7 on glioma progression was measured by performing CCK-8 and apoptosis assays, cell cycle-related experiments and animal experiments. The effect of RNF7 on PI3K/AKT signalling pathway was tested by Western blotting. First, we found that RNF7 was upregulated in tumour tissue compared with normal brain tissue, especially in high-grade glioma, and the high expression of RNF7 was significantly related to tumour size, Karnofsky Performance Scale score and a poor prognosis. Second, RNF7 overexpression facilitated tumour cell cycle progression and cell proliferation and suppressed apoptosis. Conversely, RNF7 knockdown suppressed tumour cell cycle progression and cell proliferation and facilitated apoptosis. Furthermore, follow-up mechanistic studies indicated that RNF7 could facilitate glioma cell proliferation and cell cycle progression and inhibit apoptosis by activating the PI3K/AKT signalling pathway. This study shows that RNF7 can clearly promote glioma cell proliferation by facilitating cell cycle progression and inhibiting apoptosis by activating the PI3K/AKT signalling pathway. Targeting the RNF7/PI3K/AKT axis may provide a new perspective on the prevention or treatment of glioma.     

IL‐17A promotes cell migration and invasion of glioblastoma cells via activation of PI3K/AKT signalling pathway

Glioblastomas (GBMs) are the most common of both benign and malignant primary brain tumours, in which the inflammatory and immunologic abnormalities are involved. Interleukin‐17A (IL‐17A) plays an important role in various inflammatory diseases and cancers. Several recent studies revealed that the expression of IL‐17A was overexpressed in human GBMs tissue. However, the accurate role of IL‐17A in GBMs remains unclear. In this study, we aimed to explore the effect of IL‐17A on cell migration and invasion of GBMs and the mechanism by which the effects occurred. We found that exogenous IL‐17A promoted significantly cell migration and invasion abilities in two GBMs cell lines (U87MG and U251) in a time‐dependent manner. In addition, the protein expressions of PI3K, Akt and MMP‐2/9 were increased in the GBMs cells challenged by IL‐17A. Furthermore, a tight junction protein ZO‐1 was down‐regulated but Twist and Bmi1 were up‐regulated. Treatment with a PI3K inhibitor (LY294002) significantly reduced the abilities of both migration and invasion in U87MG and U251 cells. LY294002 treatment also attenuated the IL‐17A causing increases of protein levels of PI3K, AKT, MMP‐2/9, Twist and the decreases of protein level of ZO‐1 in the U87MG and U251 cells. Taken together, we concluded that IL‐17A promotes the GBM cells migration and invasion via PI3K/AKT signalling pathway. IL‐17A and its related signalling pathways may be potential therapeutic targets for GBM.     

Inhibition of PLK4 might enhance the anti-tumour effect of bortezomib on glioblastoma via PTEN/PI3K/AKT/mTOR signalling pathway

Glioblastoma (GBM) is one of the most common aggressive cancers of the central nervous system in adults with a high mortality rate. Bortezomib is a boronic acid–based potent proteasome inhibitor that has been actively studied for its anti-tumour effects through inhibition of the proteasome. The proteasome is a key component of the ubiquitin-proteasome pathway that is critical for protein homeostasis, regulation of cellular growth, and apoptosis. Overexpression of polo-like kinase 4 (PLK4) is commonly reported in tumour cells and increases their invasive and metastatic abilities. In this study, we established a cell model of PLK4 knockdown and overexpression in LN-18, A172 and LN-229 cells and found that knockdown of PLK4 expression enhanced the anti-tumour effect of bortezomib. We further found that this effect may be mediated by the PTEN/PI3K/AKT/mTOR signalling pathway and that the apoptotic and oxidative stress processes were activated, while the expression of matrix metalloproteinases (MMPs) was down-regulated. Similar phenomenon was observed using in vitro experiments. Thus, we speculate that PLK4 inhibition may be a new therapeutic strategy for GBM.     

CHRDL2 promotes osteosarcoma cell proliferation and metastasis through the BMP-9/PI3K/AKT pathway

Various studies demonstrated that bone morphogenetic proteins (BMPs) and their antagonists contribute to the development of cancers. Chordin-like 2 (CHRDL2) is a member of BMP antagonists. However, the role and its relative mechanism of CHRDL2 in osteosarcoma remains unclear. In the present study, we demonstrated that the expression of CHRDL2 was significantly upregulated in osteosarcoma tissues and cell lines compared with adjacent tissues and human normal osteoblast. Inhibition of CHRDL2 decreased the proliferation and colony formation of osteosarcoma cells in vitro, as well as the migration and invasion. CHRDL2 overexpression induced the opposite effects. CHRDL2 can bind with BMP-9, thus decreasing BMP-9 expression and the combination to its receptor protein kinase ALK1. It was predicted that BMP-9 regulates PI3K/AKT pathways using gene set enrichment analysis. Inhibition of CHRDL2 decreased the activation of PI3K/AKT pathway, while overexpression of CHRDL2 upregulated the activation. Increasing the expression of BMP-9 reversed the effects of CHRDL2 overexpression on the activation of PI3K/AKT pathway, as well as the proliferation and metastasis of osteosarcoma cells. Take together, our present study revealed that CHRDL2 upregulated in osteosarcoma tissues and cell lines, and promoted osteosarcoma cell proliferation and metastasis through the BMP-9/PI3K/AKT pathway. CHRDL2 maybe an oncogene in osteosarcoma, as well as novel biomarker for the diagnosis of osteosarcoma.     

Germacrone improves liver fibrosis by regulating the PI3K/AKT/mTOR signalling pathway

Liver fibrosis is a primary threat to public health, owing to limited therapeutic options. Germacrone (GM) has been shown to exert various curative effects against human diseases, including liver injury. The aim of this study was to investigate the pharmacological effects of GM in the pathophysiology of hepatic fibrosis and determine its potential mechanisms of action. A liver fibrosis rat model was established via carbon tetrachloride (CCl₄) treatment, and LX-2 cells were stimulated with TGF-β1. The effects of GM on liver fibrosis and its relationship with the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signalling pathway were investigated. In the CCl₄ fibrosis-induced rat model, GM improved histological damage, inhibited the activity of hepatic α-smooth muscle actin and improved serum alanine aminotransferase and aspartate aminotransferase levels in a dose-dependent manner. GM potently inhibited hepatic stellate cells (HSCs) growth and epithelial–mesenchymal transition (EMT) progression, as reflected by the altered expression of proliferative (Ki-67, PCNA and cleaved caspase-3) and EMT-related (E-cadherin and vimentin) proteins. In TGF-β1-stimulated LX-2 cells, GM significantly inhibited the survival and activation of HSCs and induced cell apoptosis. GM also suppressed the migration ability and reversed the EMT process in HSCs. Following GM treatment, the phosphorylation of the PI3K, AKT and mTOR proteins was reduced in the liver of CCl₄-treated rats and TGF-β1-stimulated LX-2 cells, indicating that GM may attenuate hepatic fibrosis via the PI3K/AKT/mTOR signalling pathway. These outcomes highlight the anti-fibrotic effects of GM and suggest that it is a potential therapeutic agent for the treatment of liver fibrosis.     

ROS accumulation contributes to abamectin‐induced apoptosis and autophagy via the inactivation of PI3K/AKT/mTOR pathway in TM3 Leydig cells

Abamectin (ABA) as one of the worldwide used compounds in agriculture has raised safety concerns on nontarget organism toxicity. However, the study of male reproductive system damage caused by ABA remains unclear. Our aim is to investigate the effect of ABA‐induced cytotoxicity in TM3 Leydig cells and their underlying mechanisms. ABA inhibits TM3 cell viability and proliferation via cell cycle arrested in the G0/G1 phase. In addition, ABA‐induced mitochondrial depolarization leads to an imbalance in Bcl‐2 family expression, causing caspase‐dependent apoptosis in TM3 cells. The increased ratio of cells expression LC3 protein and LC3‐II to LC3‐I indicated the activation of autophagy potentially. Further experiments revealed ABA treatment reduced phosphatidylinositol 3‐kinase (PI3K), protein kinase B (AKT) phosphorylation, and mammalian target of rapamycin (mTOR) phosphorylation. Pretreatment with a PI3K/AKT inhibitor, LY294002, mimicked the ABA‐mediated effects on cytotoxicity. Pretreatment with a PI3K/AKT agonist, insulin‐like growth factor‐1, reversed the effects of ABA. ABA caused the accumulation of intracellular reactive oxygen species (ROS) by increased intensity of the ROS indicator. However, N‐acetylcysteine as ROS scavengers inhibited ABA‐induced apoptosis and autophagy and reversed these ABA‐mediated effects on PI3K/AKT/mTOR pathway. On the basis of the above results, it is suggested that ABA exposure induces apoptosis and autophagy in TM3 cells by ROS accumulation to mediate PI3K/AKT/mTOR signaling pathway suppression.     

Rhaponticin suppresses osteosarcoma through the inhibition of PI3K-Akt-mTOR pathway

Osteosarcoma is the frequent pediatric bone cancer where pediatric osteosarcoma incidences are more than 10% within the population. Most of the patients with osteosarcoma fall within the age of 15–30 years. Therefore, in this research, we examined the anticancer effect of Rhaponticin against the human osteosarcoma (MG-63) cells. The cytotoxicity of Rhaponticin on the MC3T3-E1 and MG-63 cells was examined through the MTT assay. The intracellular ROS accumulation, cell nuclear morphological alterations, apoptotic cell death and nuclear damages, and MMP status of Rhaponticin administered MG-63 cells were inspected by fluorescent staining techniques. The cell migration was assessed through scratch assay. The mRNA expressions of PI3K-Akt-mTOR signaling proteins were studied by RT-PCR analysis. Rhaponticin showed potent cytotoxicity, substantially inhibited the MG-63 cell growth, and displayed morphological alterations. However, rhaponticin did not affect the MC3T3-E1 cell viability. Rhaponticin administered MG-63 cells demonstrated augmented intracellular ROS accretion, weakened MMP, increased nuclear damages, and increased apoptosis. Rhaponticin effectively down-regulated the PI3K-Akt-mTOR signaling cascade in the MG-63 cells. These outcomes proved that the Rhaponticin can be a hopeful chemotherapeutic agent in the future to treat human osteosarcoma.     

Simvastatin treatment promotes proliferation of human dental pulp stem cells via modulating PI3K/AKT/miR-9/KLF5 signalling pathway

Simvastatin serves as an effective therapeutic potential in the treatment of dental disease via alternating proliferation of dental pulp stem cells. First, western-blot and real-time quantitative PCR were used to detect the effect of simvastatin or LY294002 on the expression levels of AKT, miR-9 and KLF5, or determine the effect of miR-9. Simvastatin, KLF5 and AKT significantly enhanced the proliferation of pulp stem cells, whilst this effect induced by simvastatin was suppressed by LY294002, AKT siRNA, KLF5 siRNA and miR-9, and simvastatin dose-dependently upregulated the expression of PI3K. Furthermore, simvastatin upregulated PI3K and p-AKT expression in a concentration-dependent manner. LY294002 abrogated the upregulation of p-AKT expression levels induced by simvastatin, and LY294002 induced the miR-9 expression and simvastatin dose-dependently inhibited the expression of miR-9, by contrast, LY294002 reduced the KLF5 expression and simvastatin dose-dependently promoted the expression of KLF5. And using computational analysis, KLF5 was found to be a candidate target gene of miR-9, and which was further verified using luciferase assay. Finally, the level of KLF5 in cells was much lower following the transfection with miR-9 and KLF5 siRNA, and the level of AKT mRNA in cells was significantly inhibited after transfection with AKT siRNA than control. These findings suggested simvastatin could promote the proliferation of pulp stem cells, possibly by suppressing the expression of miR-9 via activating the PI3K/AKT signalling pathway, and the downregulation of miR-9 upregulated the expression of its target gene, KLF5, which is directly responsible for the enhanced proliferation of pulp stem cells.     

Inhibition of PI3K/AKT signaling via ROS regulation is involved in Rhein-induced apoptosis and enhancement of oxaliplatin sensitivity in pancreatic cancer cells

Several natural products have been demonstrated to both enhance the anti-tumor efficacy and alleviate the side effects of conventional chemotherapy drugs. Rhein, a main constituent of the Chinese herb rhubarb, has been shown to induce apoptosis in various cancer types. However, the exact pharmacological mechanisms controlling the influence of Rhein on chemotherapy drug effects in pancreatic cancer (PC) remain largely undefined. In this study, we found that Rhein inhibited the growth and proliferation of PC cells through G1 phase cell cycle arrest. Moreover, Rhein induced caspase-dependent mitochondrial apoptosis of PC cells through inactivation of the PI3K/AKT pathway. Combination treatment of Rhein and oxaliplatin synergistically enhanced apoptosis of PC cells through increased generation of intracellular reactive oxygen species (ROS) and inactivation of the PI3K/AKT pathway. Pre-treatment with the ROS scavenger N-acetyl-L-cysteine attenuated the combined treatment-induced apoptosis and restored the level of phosphorylated AKT, indicating that ROS is an upstream regulator of the PI3K/AKT pathway. The combination therapy also exhibited stronger anti-tumor effects compared with single drug treatments in vivo. Taken together, these data demonstrate that Rhein can induce apoptosis and enhance the oxaliplatin sensitivity of PC cells, suggesting that Rhein may be an effective strategy to overcome drug resistance in the chemotherapeutic treatment of PC.     

Ropivacaine inhibits proliferation and invasion and promotes apoptosis and autophagy in bladder cancer cells via inhibiting PI3K/AKT pathway

Application of a certain concentration of local anesthetics during tumor resection inhibits the progression of tumor. The effects of ropivacaine in bladder cancer (BC) have never been explored. We explored the effects of ropivacaine on the progression of BC in vitro and in vivo. CCK8 assay and EDU staining was conducted to examine cell proliferation. Flow cytometry and transwell assay were performed to evaluate apoptosis and invasion, respectively. Expression of light chain 3 (LC3) was observed through immunofluorescence. Furthermore, the xenograft tumor model of BC was built to detect the effects of ropivacaine in vivo. IHC and TUNEL assay were conducted to detect cell proliferation and apoptosis in vivo. Ropivacaine inhibited the proliferation of T24 and 5639 cells with the 50% inhibitory concentration (IC50) of 20.08 and 31.86 µM, respectively. Ropivacaine suppressed the invasion ability and induces the apoptosis of cells. Besides, ropivacaine triggers obvious autophagy in BC cells. Moreover, ropivacaine blocks the PI3K/AKT signal pathway in BC cells. The impact of ropivacaine on cell viability, motility, and autophagy was reversed by 740 Y-P, the activator of PI3K/AKT signal pathway. The in vivo experiments demonstrated that ropivacaine inhibited the proliferation and mobility of BC. Ropivacaine has anti-carcinoma effects in BC via inactivating PI3K/AKT pathway, providing a new theoretical reference for the use of local anesthetics in the treatment of BC.