Cross-talk between mitogenic Ras/MAPK and survival PI3K/Akt pathways: a fine balance. Biochem Soc Trans. 2012;40:139-146. [PMID: 22260680 DOI: 10.1042/BST20110609]

Effects and Mechanisms of Phthalates' Action on Reproductive Processes and Reproductive Health: A Literature Review

The production of plastic products, which requires phthalate plasticizers, has resulted in the problems for human health, especially that of reproductive health. Phthalate exposure can induce reproductive disorders at various regulatory levels. The aim of this review was to compile the evidence concerning the association between phthalates and reproductive diseases, phthalates-induced reproductive disorders, and their possible endocrine and intracellular mechanisms. Phthalates may induce alterations in puberty, the development of testicular dysgenesis syndrome, cancer, and fertility disorders in both males and females. At the hormonal level, phthalates can modify the release of hypothalamic, pituitary, and peripheral hormones. At the intracellular level, phthalates can interfere with nuclear receptors, membrane receptors, intracellular signaling pathways, and modulate gene expression associated with reproduction. To understand and to treat the adverse effects of phthalates on human health, it is essential to expand the current knowledge concerning their mechanism of action in the organism.

Simultaneous Targeting of RSK and AKT Efficiently Inhibits YB-1-Mediated Repair of Ionizing Radiation-Induced DNA Double-Strand Breaks in Breast Cancer Cells

PURPOSE

Y-box binding protein 1 (YB-1) overexpression is associated with chemotherapy- and radiation therapy resistance. Ionizing radiation (IR), receptor tyrosine kinase ligands, and mutation in KRAS gene stimulate activation of YB-1. YB-1 accelerates the repair of IR-induced DNA double-strand breaks (DSBs). Ribosomal S6 kinase (RSK) is the main kinase inducing YB-1 phosphorylation. We investigated the impact of RSK targeting on DSB repair and radiosensitivity.

MATERIALS AND METHODS

The triple negative breast cancer (TNBC) cell lines MDA-MB-231, MDA-MB-468, and Hs 578T, in addition to non-TNBC cell lines MCF7, HBL-100, and SKBR3, were used. MCF-10A cells were included as normal breast epithelial cells. The RSK inhibitor LJI308 was used to investigate the role of RSK activity in S102 phosphorylation of YB-1 and YB-1-associated signaling pathways. The activation status of the underlying pathways was investigated by Western blotting after treatment with pharmacologic inhibitors or transfection with siRNA. The impact of LJI308 on DSB repair and postirradiation cell survival was tested by the γH2AX foci and the standard clonogenic assays, respectively.

RESULTS

LJI308 inhibited the phosphorylation of RSK (T359/S363) and YB-1 (S102) after irradiation, treatment with EGF, and in cells expressing a KRAS mutation. LJI308 treatment slightly inhibited DSB repair only in some of the cell lines tested. This was shown to be due to PI3K-dependent stimulation of AKT or constitutive AKT activity mainly in cancer cells but not in normal breast epithelial MCF-10A cells. Simultaneous targeting of AKT and RSK strongly blocked DSB repair in all cancer cell lines, independent of TNBC status or KRAS mutation, with a minor effect in MCF-10A cells. Cotargeting of RSK- and AKT-induced radiation sensitivity in TNBC MDA-MB-231 and non-TNBC MCF7 cells but not in MCF-10A cells.

CONCLUSIONS

Simultaneous targeting of RSK and AKT might be an efficient approach to block the repair of DSBs after irradiation and to induce radiosensitization of breast cancer cells.

Luteolin ameliorates experimental colitis in mice through ERK-mediated suppression of inflammation, apoptosis and autophagy

Ulcerative colitis (UC) is a chronic inflammatory disease with increasing incidence and prevalence worldwide. Currently used treatments of UC are unsatisfactory, while natural bioactive compounds are considered to be emerging therapeutic agents. Luteolin (Lut) is a natural compound with beneficial effects in a variety of diseases, however, its effect in UC has been poorly studied. In this study we investigated the effect of Lut in posttreatment and cotreatment of dextran sulfate sodium (DSS)-induced experimental colitis in mice. In addition, the role of extracellular signal-regulated kinases 1/2 (ERK1/2) in the mechanism of action of Lut in experimental colitis was investigated using the ERK inhibitor PD0325901. Lut attenuated symptoms of DSS-induced colitis in mice, ameliorated colon tissue damage and reduced inflammation, apoptosis and autophagy. The effect was more pronounced if Lut was administered simultaneously with DSS. The administration of ERK inhibitor exacerbated DSS-induced colitis symptoms and prevented the protective effects of Lut. The results provide new mechanistic details underlying the anti-inflammatory, anti-apoptotic and anti-autophagic effects of Lut through the activation of the ERK signaling pathway. This suggested that Lut can be used as a novel therapeutic candidate in the treatment of UC or could be used as a supplement to existing therapy.

CCT128930 induces G1-phase arrest and apoptosis and synergistically enhances the anticancer efficiency of VS5584 in human osteosarcoma cells

Osteosarcoma is a highly invasive primary malignant bone tumor. PI3K/mTOR pathway plays a key role in tumor progression, and inhibition of PI3K/mTOR pathway represents a novel strategy in therapy of osteosarcoma. CCT128930 and VS5584 are both inhibitors of PI3K/mTOR, but the anticancer mechanism of CCT128930 or/and VS5584 against human osteosarcoma cells remains unclear. Herein, U2OS and MG63 human osteosarcoma cells were cultured, and the anticancer effects of CCT128930 alone and the combined effect of CCT128930 and VS5584 against human osteosarcoma cells were explored. The results showed that CCT128930 as PI3K/mTOR inhibitor effectively inhibited p-p70 and p-AKT expression and dose-dependently inhibited U2OS cells and MG63 human osteosarcoma cells growth. Further studies found that CCT128930 triggered significant G-1 phase arrest and apoptosis, as convinced by the dysfunction of p27, Cyclin B1, Cyclin D1 and Cdc2, and PARP cleavage and caspase-3 activation. Moreover, CCT128930 treatment obviously enhanced VS5584-induced growth inhibition and apoptosis in human osteosarcoma cells, followed by enhanced PARP cleavage and caspase-3 activation. Taken together, CCT128930 alone or combined treatment with CCT128930 and VS5584 both effectively inhibited human osteosarcoma cells growth by induction of G1-phase arrest and apoptosis through regulating PI3K/mTOR and MAPKs pathways.

Salicylidene acylhydrazides attenuate survival of SH-SY5Y neuroblastoma cells through affecting mitotic regulator Speedy/RINGO and ERK/MAPK-PI3K/AKT signaling

Salicylidene acylhydrazide group synthetic compounds ME0053, ME005 and ME0192 are known for their iron chelating properties and due to these properties they are primarily used for blocking the bacterial type 3 secretory virulence system. On the other side, targeting the metabolic pathways of iron can provide new tools for cancer prognosis and treatment. Therefore, in this study, considering their iron chelating function, the effects of the compounds ME0053, ME0055 and ME0192 were investigated in SH-SY5Y neuroblastoma cell line. Iron chelating compounds are generally known to be effective in tumor development and metastasis by targeting iron in the cell. They can exert this effect through molecules such as cyclin, CDKs, as well as signaling pathways such as PI3K/AKT and ERK/MAPK. For this reason, we analyzed the effect of the iron chelating compounds of ME0053, ME0055 and ME0192 on cell viability and proliferation rate both through ERK/MAPK and PI3K/AKT signal paths, and through the oncogenic Speedy/RINGO protein that is likely to have a regulatory effect on these two signaling pathways. Apoptosis was also investigated by measuring the amount of active caspase-3, an apoptotic marker. Along with the decrease observed in the Speedy/RINGO level, it was observed that the PI3K/AKT and ERK/MAPK signaling were decreased. This suggests that ME0053, ME0055 and ME0192 compounds significantly decrease the Speedy/RINGO expression which has a regulatory effect on the ERK/MAPK and PI3K/AKT signaling. Besides, analyzing active caspase-3 levels showed that the compounds ME0053, ME0055 and ME0192 increased its level by 218%, 60% and 175% in SH-SY5Y cells, respectively. The results of this study will pave the way for better understanding of the regulation of cancer-related ERK/MAPK and PI3K/AKT pathways and the oncogenic Speedy/RINGO which potentially affects these pathways, through synthetic salicylidene acylhydrazides and their therapeutic use in cancer.

Speedy/RINGO protein interacts with ERK/MAPK and PI3K/AKT pathways in SH-SY5Y neuroblastoma cells

Abnormal activity of ERK/MAPK and PI3K/AKT pathways is one of the most important factors for the development of many cancer types including neuroblastoma cancer. Apart from these two pathways, some cell cycle regulators such as Speedy/RINGO also contribute to neuroblastoma development. There is data reinforcing the possible communication of the components of ERK/MAPK and PI3K/AKT pathways in carcinogenic process. In addition to this, there are studies about the direct/indirect interaction of Speedy/RINGO with these pathways in different cell types other than neuroblastoma. However, there is not any study available showing the interaction of Speedy/RINGO with both pathways in neuroblastoma cells. Therefore, the aim of this study is to determine the possible effect of Speedy/RINGO on PI3K/AKT and ERK/MAPK pathways in SH-SY5Y neuroblastoma cells. For this aim, Speedy/RINGO was silenced by siRNA technique to analyze the effects of direct inhibition of Speedy/RINGO on these pathways. Results showed that Speedy/RINGO silencing caused a significant decrease in MEK1/2 expression and AKT phosphorylation. Afterward, MEK1/2 was inhibited using a specific inhibitor U0126. Data reveal a corresponding decrease in the Speedy/RINGO expression and AKT phosphorylation indicating a reciprocal interaction between ERK/MAPK and Speedy/RINGO. In addition, MTS analysis showed that both ERK/MAPK inhibition and Speedy/RINGO silencing significantly reduced the viability of SH-SY5Y cells. This study provides information about a possible interaction of Speedy/RINGO with PI3K/AKT and ERK/MAPK pathways in SH-SY5Y cells for the first time. It will not only help to better understand the cancer-prone interactions of these pathways but also enable us to identify the appropriate molecular targets for developing efficient treatment strategies.

Ligustilide Attenuates Ischemia Reperfusion-Induced Hippocampal Neuronal Apoptosis via Activating the PI3K/Akt Pathway

Ligustilide (LIG), a main lipophilic component isolated from Cnidii Rhizoma (Cnidium officinale, rhizome) and Angelicae Gigantis Radix (Angelica gigas Nakai, root), has been shown to alleviate cerebral ischemia injury and paly a neuroprotective role. We investigated mechanisms underlying the antiapoptotic effects of LIG in vitro and in vivo, respectively, using cultured primary hippocampal neurons under oxygen-glucose deprivation/reperfusion (OGD/R) and rats under cerebral ischemia reperfusion(I/R) conditions. In vitro studies revealed that the suppressed apoptosis in hippocampal neurons upon LIG treatment was associated with reduced calcium influx and generation of reactive oxygen species. The LIG-treated hippocampal neurons exhibited decreased the ratio of Bax/Bcl-2, and the release of CytC from mitochondria as well as the expression of cleaved caspase-3, which were accompanied with enhanced the phosphorylation of Akt protein, in a PI3K-dependent manner. In vivo studies demonstrated a neuroprotective role of LIG in attenuating cerebral infarction volume, neurological injury and hippocampal neuron injury, suggesting that LIG could reverse ischemia reperfusion(I/R)-induced apoptosis of hippocampal neurons. These results together suggest that LIG may be considered as a neuroprotectant in the treatment of ischemia stroke.

Quantification of model and data uncertainty in a network analysis of cardiac myocyte mechanosignalling

Cardiac myocytes transduce changes in mechanical loading into cellular responses via interacting cell signalling pathways. We previously reported a logic-based ordinary differential equation model of the myocyte mechanosignalling network that correctly predicts 78% of independent experimental results not used to formulate the original model. Here, we use Monte Carlo and polynomial chaos expansion simulations to examine the effects of uncertainty in parameter values, model logic and experimental validation data on the assessed accuracy of that model. The prediction accuracy of the model was robust to parameter changes over a wide range being least sensitive to uncertainty in time constants and most affected by uncertainty in reaction weights. Quantifying epistemic uncertainty in the reaction logic of the model showed that while replacing 'OR' with 'AND' reactions greatly reduced model accuracy, replacing 'AND' with 'OR' reactions was more likely to maintain or even improve accuracy. Finally, data uncertainty had a modest effect on assessment of model accuracy. This article is part of the theme issue 'Uncertainty quantification in cardiac and cardiovascular modelling and simulation'.

Berberine represses human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt signaling pathways

Berberine, an isoquinoline alkaloid from Coptidis Rhizoma, has been characterized as a potential anticancer drug due to its good anti-tumor effects. However, the molecular mechanisms involved in anti-gastric cancer remain poorly understood. Herein, the role of berberine in gastric cancer suppression by inducing cytostatic autophagy in vitro and in vivo was first investigated. Results showed that berberine induced an obvious growth inhibitory effect on gastric cancer BGC-823 cells without toxicity to human peripheral blood mononuclear cells. Treatment with berberine triggered cell autophagy, as demonstrated by the punctuate distribution of monodansylcadaverine staining and GFP-LC3, as well as the LC3-II, Beclin-1 and p-ULK1 promotion, and p62 degradation. Inhibition of autophagy by 3-MA, CQ, Baf-A1 and BECN1 siRNA obviously increased cell viability of berberine-exposed gastric cancer cells, which confirmed the anti-cancer role of autophagy induced by berberine. Mechanistic studies showed that berberine inhibited mTOR, Akt and MAPK (ERK, JNK and p38) pathways thereby inducing autophagy. Inhibition of above pathways increases berberine induced autophagy and cytotoxicity. Interestingly, mTOR/p70S6K was inhibited by the MAPK but not Akt. Furthermore, inhibition of autophagy reversed berberine down-regulated mTOR, Akt and MAPK. In xenografts, the berberine induced autophagy leads to suppression of tumor proliferation with no side-effect, and western blotting displayed an apparent attenuation of p-mTOR, p-p70S6K, p-Akt, p-ERK, p-JNK and p-p38 in tumors from berberine treated mice. Briefly, these results indicated that berberine repressed human gastric cancer cell growth in vitro and in vivo by inducing cytostatic autophagy via inhibition of MAPK/mTOR/p70S6K and Akt, and provided a molecular basis for the treatment of gastric cancer.

The Diagnosis, Treatment, Prognosis and Molecular Pathology of Borderline Ovarian Tumors: Current Status and Perspectives

Borderline ovarian tumors (BOTs) are a type of low malignant potential tumor that is typically associated with better outcomes than ovarian cancer. Indeed, its 10-year survival rate is as high as 95%. However, there is a small subset of patients who experience relapse and eventually die. It has been shown that the prognosis of BOTs was based on pathological diagnosis, the age at diagnosis, pre-operative carbohydrate antigen 125 level, invasive implants, and micropapillary patterns. Now the molecular-targeted therapy and molecular-genetic diagnosis have developed into a form of precision medicine. Recent studies on extensive molecular characterizations and molecular pathological mechanisms of BOTs have helped us understand the genomic landscapes of BOTs, and therefore BOTs could be reclassified into biologically and clinically more accurate and effective subtypes. The purpose of this review is to summarize current status for the diagnosis and treatment of BOTs and to describe the research progress on molecular pathologies, with a goal of providing a theoretical perspective for the diagnosis and treatment of BOTs.

YWHAE long non-coding RNA competes with miR-323a-3p and miR-532-5p through activating K-Ras/Erk1/2 and PI3K/Akt signaling pathways in HCT116 cells

YWHAE gene product belongs to the 14-3-3 protein family that mediates signal transduction in plants and mammals. Protein-coding and non-coding RNA (lncRNA) transcripts have been reported for this gene in human. Here, we aimed to functionally characterize YWHAE-encoded lncRNA in colorectal cancer-originated cells. RNA-seq analysis showed that YWHAE gene is upregulated in colorectal cancer specimens. Additionally, bioinformatics analysis suggested that YWHAE lncRNA sponges miR-323a-3p and miR-532-5p that were predicted to target K-Ras 3'UTR sequence. Overexpression of YWHAE lncRNA resulted in upregulation of K-Ras gene expression, while overexpression of both miR-323a-3p and miR-532-5p had an inverse effect, detected by RT-qPCR. Consistently, western blot analysis confirmed that YWHAE lncRNA overexpression upregulated K-Ras/Erk1/2 and PI3K/Akt signaling pathways, while miR-323a-3p and miR-532-5p overexpression suppressed both pathways in HCT116 cells. Furthermore, dual luciferase assay validated the direct interaction of miR-323a-3p and miR-532-5p with K-Ras 3'UTR sequence and supported the sponging effect of YWHAE lncRNA over both miRNAs. These results suggested YWHAE lncRNA as an oncogene that exerts its effect through sponging miR-323a-3p and miR-532-5p and in turn, upregulates K-Ras/Erk1/2 and PI3K/Akt signaling pathways. Consistently, flow cytometry analysis, MTT assay and measuring cyclin D1 gene expression, confirmed the cell cycle stimulatory effect of YWHAE lncRNA, while miR-323a-3p and miR-532-5p showed an inhibitory effect on cell cycle progression. Finally, wound-healing assay supported the cell migratory effect of YWHAE lncRNA in HCT116 cells. This study identified a novel mechanism involving YWHAE-encoded lncRNA, miR-323a-3p and miR-532-5p in regulating HCT116 cell survival and suggested a potential therapeutic avenue for colorectal cancer.

Alternate-day fasting alleviates diabetes-induced glycolipid metabolism disorders: roles of FGF21 and bile acids

Glycolipid metabolism disorder is one of the causes of type 2 diabetes (T2D). Alternate-day fasting (ADF) is an effective dietary intervention to counteract T2D. The present study is aimed to determine the underlying mechanisms of the benefits of ADF metabolic on diabetes-induced glycolipid metabolism disorders in db/db mice. Here, leptin receptor knock-out diabetic mice were subjected to 28 days of isocaloric ADF. We found that ADF prevented insulin resistance and bodyweight gain in diabetic mice. ADF promoted glycogen synthesis in both liver and muscle. ADF also activated recombinant insulin receptor substrate-1 (IRS-1)/protein kinase B (AKT/PKB) signaling，inactivated inflammation related AMP-activated protein kinase (AMPK) and the inflammation-regulating nuclear factor kappa-B (NF-κB) signaling in the liver. ADF also suppressed lipid accumulation by inactivating the expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and sterol regulatory element-binding protein-1c (SREBP-1c). Furthermore, ADF elevated the expression of fibroblast growth factor 21 (FGF21) and down-stream signaling AMPK/silent mating type information regulation 2 homolog 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) in the liver of diabetic mice. The mitochondrial biogenesis and autophagy were also stimulated by ADF. Interestingly, ADF also enhanced the bile acids (BAs) metabolism by generating more cholic acid (CA), deoxycholic acid (DCA) and tauroursodeoxycholic acid (TUDCA) in db/db mice. In conclusion, ADF could significantly inhibit T2D induced insulin resistance and obesity, promote insulin signaling，reduce inflammation, as well as promote glycogen synthesis and lipid metabolism. It possibly depends on FGF21 and BA metabolism to enhance mitochondrial biosynthesis and energy metabolism.

VEGF Production Is Regulated by the AKT/ERK1/2 Signaling Pathway and Controls the Proliferation of Toxoplasma gondii in ARPE-19 Cells

The retina is the primary site of Toxoplasma gondii infection in the eye, and choroidal neovascularization in ocular toxoplasmosis is one of the most important causes of visual impairment. Vascular endothelial growth factor (VEGF) is one of the key regulators of blood vessel development, however, little is known about the mechanisms of T. gondii-induced VEGF production in ocular toxoplasmosis. Here, we investigate the effect of T. gondii on VEGF production regulation in human retinal pigment epithelium ARPE-19 cells and attempted to unveil the underlying mechanism of this event by focusing on the interaction between parasite and the selected host intracellular signaling pathways. T. gondii infection increased the expression of VEGF mRNA and protein in ARPE-19 cells in parasite burden- and infection time-dependent manner. The proportional increase of VEGF upstream regulators, HIF-1α and HO-1, was also observed. T. gondii induced the activation of host p-AKT, p-ERK1/2, and p-p38 MAPK in ARPE-19 cells in a parasite-burden dependent manner. However, VEGF expression decreased after the pre-treatment with PI3K inhibitors (LY294002 and GDC-0941), ERK1/2 inhibitor (PD098059), and p38 MAPK inhibitor (SB203580), but not JNK inhibitor (SP600125), in a dose-dependent manner. The anti-VEGF agent bevacizumab or VEGF siRNA transfection prominently inhibited the activation of p-AKT and p-ERK1/2, but not p-p38 MAPK and JNK1/2 in T. gondii-infected ARPE-19 cells. Bevacizumab treatment or VEGF siRNA transfection significantly inhibited the proliferation of T. gondii tachyzoites in the host cell, dose-dependently, but not invasion of parasites. VEGF-receptor 2 (VEGF-R2) antagonist, SU5416, attenuated VEGF production and tachyzoite proliferation in T. gondii-infected ARPE-19 cells in a dose-dependent manner. Collectively, T. gondii prominently induces VEGF production in ARPE-19 cells, and VEGF and AKT/ERK1/2 signaling pathways mutually regulate each other in T. gondii-infected ARPE-19 cells, but not p38 MAPK and JNK1/2 signaling pathways. VEGF and VEGF-R2 control the parasite proliferation in T. gondii-infected ARPE-19 cells. From this study, we revealed the putative mechanisms for VEGF induction as well as the existence of positive feedback between VEGF and PI3K/MAPK signaling pathways in T. gondii-infected retinal pigment epithelium.

Euscaphic acid and Tormentic acid protect vascular endothelial cells against hypoxia-induced apoptosis via PI3K/AKT or ERK 1/2 signaling pathway

AIMS

Euscaphic acid and Tormentic acid are aglycones of Kaji-ichigoside F1 and Rosamultin, respectively. These four compounds are pentacyclic triterpenoid, isolated from the subterranean root of the Potentilla anserina L. Based on the protective roles against hypoxia-induced apoptosis of Euscaphic acid and Tormentic acid in vascular endothelial cells, this study was designed to determine the mechanisms.

MAIN METHODS

The model of hypoxic injuries in EA. hy926 cells was established. Through applications of PI3K/AKT inhibitor, LY294002 and ERK1/2 inhibitor, PD98059, we explored the relationships between pharmacodynamic mechanisms and PI3K/AKT or ERK 1/2 signaling pathway. The anti-hypoxic effects were studied by methyl-thiazolyl-tetrazolium (MTT) assay, Hematoxylin-Eosin (HE) staining, DAPI staining, and flow cytometry. The mechanisms of anti-mitochondrial apoptosis were explored by western blot. The expressions of p-ERK 1/2, ERK 1/2, p-AKT, AKT, p-NF-κB, NF-κB, Bcl-2, Bax, Cyt C, cleaved caspase-9 and cleaved caspase-3 were detected.

KEY FINDINGS

Euscaphic acid protected vascular endothelial cells against hypoxia-induced apoptosis via ERK1/2 signaling pathway, and Tormentic acid brought its efficacy into full play via PI3K/AKT and ERK1/2 signaling pathways. In addition, PI3K/AKT signaling pathway positively regulated ERK1/2 pathway, and ERK1/2 pathway negatively regulated PI3K/AKT pathway.

SIGNIFICANCE

This evidence provides theoretical and experimental basis for the following research on anti-hypoxic drugs of Potentilla anserina L.

Kaji-Ichigoside F1 and Rosamultin Protect Vascular Endothelial Cells against Hypoxia-Induced Apoptosis via the PI3K/AKT or ERK1/2 Signaling Pathway

As a pair of differential isomers, Kaji-ichigoside F1 and Rosamultin are both pentacyclic triterpenoids isolated from the subterranean root of Potentilla anserina L., a plant used in folk medicine in western China as antihypoxia and anti-inflammatory treatments. We demonstrated that Kaji-ichigoside F1 and Rosamultin effectively prevented hypoxia-induced apoptosis in vascular endothelial cells. We established a hypoxia model, using EA.hy926 cells, to further explore the mechanisms. Hypoxia promoted the phosphorylation of AKT, ERK1/2, and NF-κB. In hypoxic cells treated with Kaji-ichigoside F1, p-ERK1/2 and p-NF-κB levels were increased, while the level of p-AKT was decreased. Treatment with Rosamultin promoted phosphorylation of ERK1/2, NF-κB, and AKT in hypoxic cells. Following the addition of LY294002, the levels of p-AKT, p-ERK1/2, and p-NF-κB decreased significantly. Addition of PD98059 resulted in reduced levels of p-ERK1/2 and p-NF-κB, while p-AKT levels were increased. Pharmacodynamic analysis demonstrated that both LY294002 and PD98059 significantly inhibited the positive effects of Kaji-ichigoside F1 on cell viability during hypoxia, consistent with the results of hematoxylin-eosin (H&E) staining, DAPI staining, and flow cytometry. The antihypoxia effects of Rosamultin were remarkably inhibited by LY294002 but promoted by PD98059. In Kaji-ichigoside F1- and Rosamultin-treated cells, Bcl2 expression was significantly upregulated, while expression of Bax and cytochrome C and levels of cleaved caspase-9 and cleaved caspase-3 were reduced. Corresponding to pharmacodynamic analysis, LY294002 inhibited the regulatory effects of Kaji-ichigoside F1 and Rosamultin on the above molecules, while PD98059 inhibited the regulatory effects of Kaji-ichigoside F1 but enhanced the regulatory effects of Rosamultin. In conclusion, Kaji-ichigoside F1 protected vascular endothelial cells against hypoxia-induced apoptosis by activating the ERK1/2 signaling pathway, which positively regulated the NF-κB signaling pathway and negatively regulated the PI3K/AKT signaling pathway. Rosamultin protected vascular endothelial cells against hypoxia-induced apoptosis by activating the PI3K/AKT signaling pathway and positively regulating ERK1/2 and NF-κB signaling pathways.

Tyrosine Kinase Inhibitors in Cancer: Breakthrough and Challenges of Targeted Therapy

Receptor tyrosine kinases (RTKs) are key regulatory signaling proteins governing cancer cell growth and metastasis. During the last two decades, several molecules targeting RTKs were used in oncology as a first or second line therapy in different types of cancer. However, their effectiveness is limited by the appearance of resistance or adverse effects. In this review, we summarize the main features of RTKs and their inhibitors (RTKIs), their current use in oncology, and mechanisms of resistance. We also describe the technological advances of artificial intelligence, chemoproteomics, and microfluidics in elaborating powerful strategies that could be used in providing more efficient and selective small molecules inhibitors of RTKs. Finally, we discuss the interest of therapeutic combination of different RTKIs or with other molecules for personalized treatments, and the challenge for effective combination with less toxic and off-target effects.

Fucoidan Induces Apoptosis and Inhibits Proliferation of Hepatocellular Carcinoma via the p38 MAPK/ERK and PI3K/Akt Signal Pathways

Purpose

Fucoidan is a natural bioactive product with broad therapeutic applications. Hepatocellular carcinoma (HCC) is a common malignancy of the liver associated with a relatively high mortality rate; thus, effective treatments are urgently needed. Here, the effects of fucoidan on HCC and the underlying mechanism were explored.

Methods

The proliferation and apoptosis of two HCC cell lines (BEL-7402 and LM3) treated with different concentrations of fucoidan or saline were assessed. The levels of proliferating cell nuclear antigen (PCNA) and CCK8 assay were used to determine proliferative capabilities of BEL-7402 and LM3 cells. Apoptosis of LM3 cells was assessed by Hoechst 33342 staining, Western blotting and flow cytometry. The capability of fucoidan to inhibit the growth of LM3 cells was investigated by monitoring of the p38 MAPK/ERK pathways and the upstream kinases, PI3K/Akt. LM3 xenograft tumors were used for in vivo verification.

Results

Cell proliferation and apoptosis assays consistently showed that fucoidan has an inhibitory effect on cell growth. Fucoidan significantly promoted apoptosis of LM3 cells through a mechanism involving activation of caspases 8, 9, and 3 accompanied by changes in B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax), as well as changes in the phosphorylation of p38 MAPK and ERK. Fucoidan also altered the phosphorylation of its upstream kinase, Akt. Fucoidan treatment markedly reduced the growth of LM3 xenograft tumors, consistent with the in vitro results.

Conclusion

Fucoidan conveys antitumor effects and, thus, should be further explored as a potential treatment option for HCC.

Resistance of melanoma cells to anticancer treatment: a role of vascular endothelial growth factor

Melanoma is one of the most aggressive and resistant to treatment neoplasms. There are still many challenges despite many promising advances in anticancer treatment. Currently, the main problem for all types of treatment is associated with heterogeneity. Due to heterogeneity of cancer cells, "precise" targeting of a medicine against a single phenotype limits the efficacy of treatment and affects resistance to applied therapy. Therefore it is important to understand aetiology and reasons for heterogeneity in order to develop effective and long-lasting treatment. This review summarises roles of vascular endothelial growth factor (VEGF) that may stimulate growth of a melanoma tumour irrespective of its proangiogenic effects, contributing to cancer heterogeneity. VEGF triggers processes associated with extracellular matrix remodelling, cell migration, invasion, angiogenesis, inhibition of immune responses and favours phenotypic plasticity and epithelial-mesenchymal transition. Consequently, it participates in mechanisms of interactions between melanoma cancer cells and microenvironment and it can modify sensitivity to therapeutic factors.

Gene network analysis reveals a core set of genes involved in the immune response of Japanese flounder (Paralichthys olivaceus) against Vibrio anguillarum infection

Japanese flounder (Paralichthys olivaceus) is one of the most economically important marine fish cultured in north Asia. Vibrio anguillarum is a severe bacterial pathogen to Japanese flounder and many other aquaculture species. In order to understand the immune response of flounder during bacterial infection, we systematically examined the transcriptome profiles of flounder spleen at three time points after V. anguillarum challenge. More than one billion high quality reads were obtained, approximately 80.70% of which were successfully mapped to the reference genome of flounder. A total of 6060, 4688 and 4235 differentially expressed genes (DEGs) were captured at 6, 12 and 24-h post-infection, respectively. The DEGs exhibited dynamic changes in expression and were assigned into four different profiles based on expression trend. GO and KEGG analysis showed that the DEGs were enriched in various immune-related terms, including response to stimulation, immune system and pathways of cytokine-cytokine receptor interaction, Jak-STAT signaling and Toll-like receptor signaling. Furthermore, a network of highly interactive DEGs involved in 11 immune-related pathways was detected by utilizing the weighted co-expressing network analysis (WGCNA). Accordingly, 26 hub genes were discovered that constituted an elaborate immune regulatory network and functioned mainly in pathogen recognition, antigen processing, and molecular signaling. The results of this study provided the first systematical transcriptome profile of flounder in association with V. anguillarum infection and can serve as a valuable resource of target genes for future studies on the molecular mechanisms underlying the immune defense of flounder against bacterial infection.

A novel marine halophenol derivative attenuates lipopolysaccharide-induced inflammation in RAW264.7 cells via activating phosphoinositide 3-kinase/Akt pathway

BACKGROUND

2,4',5'-Trihydroxyl-5,2'-dibromo diphenylmethanone (LM49), a novel active halophenol derivative synthesized by our group from marine plants, exhibits strong anti-inflammatory activities. However, molecular machineries involved in its effect have not been fully identified. The study was aimed to investigate the anti-inflammatory effect of LM49 on lipopolysaccharide (LPS)-stimulated RAW264.7 cells and its underlying mechanism.

METHODS

RAW264.7 cells were treated with LPS (10 μg/mL) and then exposed to different concentrations of LM49 (i.e., 5, 10, and 15 μM) for 24 h. Cytokine release in culture medium of RAW264.7 cells was measured by enzyme-linked immunosorbent assay (ELISA). Phagocytic capacity (FITC-dextran uptake) was determined by flow cytometry. The protein level of phosphoinositide 3-kinase (PI3K), AKT and p-AKT was measured by western blot analysis.

RESULTS

Our findings revealed that LM49 reduced the production and mRNA levels of cytokines related to inflammation such as interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α), and increased the level of IL-10, an anti-inflammatory cytokine. In addition, LM49 decreased the production of nitric oxide and reactive oxygen species. Moreover, flow cytometry showed that LM49 significantly enhanced the phagocytic capacity (FITC-dextran uptake) of macrophages. The effects of LM49 were significantly inhibited by the phosphoinositide 3-kinase (PI3K) inhibitor, LY294002. In particular, LY294002 attenuated the phagocytic capacity of RAW264.7 cells induced by LM49 and prevented the effects on cytokines.

CONCLUSION

These findings suggest that LM49 possesses anti-inflammatory activity on LPS-stimulated RAW264.7 cells, in which the PI3K/Akt pathway plays an essential role. LM49 may have clinical utility as an anti-inflammatory agent. In this study, we demonstrated that a halophenol derivative (LM49) could possess anti-inflammatory activity on LPS-stimulated RAW264.7 cells by reducing pro-inflammatory cytokines and enhancing the phagocytic capacity, in which the PI3K/Akt pathway plays an essential role. LM49 may have clinical utility as an anti-inflammatory agent.

Patient-specific logic models of signaling pathways from screenings on cancer biopsies to prioritize personalized combination therapies

Mechanistic modeling of signaling pathways mediating patient-specific response to therapy can help to unveil resistance mechanisms and improve therapeutic strategies. Yet, creating such models for patients, in particular for solid malignancies, is challenging. A major hurdle to build these models is the limited material available that precludes the generation of large-scale perturbation data. Here, we present an approach that couples ex vivo high-throughput screenings of cancer biopsies using microfluidics with logic-based modeling to generate patient-specific dynamic models of extrinsic and intrinsic apoptosis signaling pathways. We used the resulting models to investigate heterogeneity in pancreatic cancer patients, showing dissimilarities especially in the PI3K-Akt pathway. Variation in model parameters reflected well the different tumor stages. Finally, we used our dynamic models to efficaciously predict new personalized combinatorial treatments. Our results suggest that our combination of microfluidic experiments and mathematical model can be a novel tool toward cancer precision medicine.

NAD(P)H Quinone Dehydrogenase 1 Ablation Inhibits Activation of the Phosphoinositide 3-Kinase/Akt Serine/Threonine Kinase and Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Pathways and Blocks Metabolic Adaptation in Hepatocellular Carcinoma

Cancer cells undergo metabolic adaptation to sustain uncontrolled proliferation. Aerobic glycolysis and glutaminolysis are two of the most essential characteristics of cancer metabolic reprogramming. Hyperactivated phosphoinositide 3-kinase (PI3K)/Akt serine/threonine kinase (Akt) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathways play central roles in cancer cell metabolic adaptation given that their downstream effectors, such as Akt and c-Myc, control most of the glycolytic and glutaminolysis genes. Here, we report that the cytosolic flavoprotein, NAD(P)H quinone dehydrogenase 1 (Nqo1), is strongly overexpressed in mouse and human hepatocellular carcinoma (HCC). Knockdown of Nqo1 enhanced activity of the serine/threonine phosphatase, protein phosphatase 2A, which operates at the intersection of the PI3K/Akt and MAPK/ERK pathways and dephosphorylates and inactivates pyruvate dehydrogenase kinase 1, Akt, Raf, mitogen-activated protein kinase kinase, and ERK1/2. Nqo1 ablation also induced the expression of phosphatase and tensin homolog, a dual protein/lipid phosphatase that blocks PI3K/Akt signaling, through the ERK/cAMP-responsive element-binding protein/c-Jun pathway. Together, Nqo1 ablation triggered simultaneous inhibition of the PI3K/Akt and MAPK/ERK pathways, suppressed the expression of glycolysis and glutaminolysis genes and blocked metabolic adaptation in liver cancer cells. Conversely, Nqo1 overexpression caused hyperactivation of the PI3K/Akt and MAPK/ERK pathways and promoted metabolic adaptation. Conclusion: In conclusion, Nqo1 functions as an upstream activator of both the PI3K/Akt and MAPK/ERK pathways in liver cancer cells, and Nqo1 ablation blocked metabolic adaptation and inhibited liver cancer cell proliferation and HCC growth in mice. Therefore, our results suggest that Nqo1 may function as a therapeutic target to inhibit liver cancer cell proliferation and inhibit HCC.

The Total Flavonoid Extract from Glycyrrhiza inflat Bat. Suppresses Atrophic Gastritis in Rats through the Akt/MAPK Pathway

Ethnopharmacological Relevance. Glycyrrhiza inflat Bat. is widely used to treat gastric ulcer and gastritis in clinic in China. Aim of the Study. To investigate the protective effects and possible mechanisms of the total flavonoid extract (TFE) from G. inflat Bat. on atrophic gastritis (AG) rats. Materials and Methods. The rat AG model was established by providing sodium deoxycholate and alcohol, and then, AG rats were treated with TFE for 30 days. Pathologic changes in gastric specimens were observed using hematoxylin and eosin staining, and the capability of gastric mucosa to secrete mucus was examined by alcian blue-periodic acid Schiff staining. Apoptosis induction in gastric tissues was measured by the TUNEL assay. The expressions of Bcl-2, Bax, and proteins in the Akt/MAPK pathway in gastric tissues were examined by immunohistochemistry and/or Western blotting. Results. Compared with the AG group, TFE attenuated the damage of gastric mucosa as reflected by the thickening of the lamina propria and the thinning of the muscularis mucosae. Moreover, TFE induced apoptosis in gastric mucosa with increasing Bax/Bcl-2 expression ratio. Concomitantly, the degrees of p-ErkThr202/Tyr204 and p-AktThr308 were decreased, whereas those of p-p38Thr180/Tyr182 and p-JNKThr183/Tyr185 were increased. Conclusion. We demonstrated the anti-AG effect of G. inflat Bat. in vivo and elucidated the underlying mechanisms that involve gastric mucosa protection through the Akt/MAPK pathway. The study provides a rationale for the application of G. inflat Bat. in the treatment of AG.

Study of the Gastrointestinal Heat Retention Syndrome in Children: From Diagnostic Model to Biological Basis

Gastrointestinal heat retention syndrome (GHRS) refers to a condition that is associated with increased gastrointestinal heat caused by a metabolic block in energy. It is common in children and is closely related to the occurrence and development of recurrent respiratory tract infection, pneumonia, recurrent functional abdominal pain, etc. However, there are no standardized diagnostic criteria to differentiate the GHRS. Therefore, this study is aimed to establish a diagnostic model for children's GHRS and explore the possible biological basis by using systems biology to achieve. Furthermore, Delphi method and the clinical data of Lasso analysis were used to screen out the core symptoms. Nineteen core symptoms of GHRS in children were screened including digestive symptoms such as dry stool, poor appetite, vomiting, and some nervous system symptoms such as night restlessness and irritability. Based on the core symptoms, a GHRS diagnosis model was established using the eXtreme Gradient Boosting (XGBoost) method, and the accuracy of internal verification reached 93.03%. Relevant targets of the core symptoms in the Human Phenotype Ontology (HPO) were retrieved, and target interactions were linked through the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and core targets were selected after topological analysis using Cytoscape. Relevant biological processes and pathways were analyzed by applying the DAVID and KEGG databases. The enriched biological processes focused on the cell proliferation, differentiation, apoptosis, and mitochondrial metabolism, which were mainly associated with PI3K-AKT, MAPK network pathways, and the Wnt signaling pathway. In conclusion, we established a diagnosis model of GHRS in children based on the core symptoms and provided an objective standard for its clinical diagnosis. And, the Wnt signaling pathway and the estrogen receptor-activated PI3K-AKT and MAPK network pathways may play important roles in the GHRS processing.

Integrin β3 promotes cardiomyocyte proliferation and attenuates hypoxia-induced apoptosis via regulating the PTEN/Akt/mTOR and ERK1/2 pathways

Objective: Integrin β3 is one of the main integrin heterodimer receptors on the surface of cardiac myocytes. Our previous studies showed that hypoxia induces apoptosis and increases integrin β3 expression in cardiomyocytes. However, the exact mechanism by which integrin β3 protects against apoptosis remains unclear. Hence, the present investigation aimed to explore the mechanism of integrin β3 in cardiomyocyte proliferation and hypoxia-induced cardiomyocyte apoptosis. Methods: Stable cells and in vivo acute and chronic heart failure rat models were generated to reveal the essential role of integrin β3 in cardiomyocyte proliferation and apoptosis. Western blotting and immunohistochemistry were employed to detect the expression of integrin β3 in the stable cells and rat cardiac tissue. Flow cytometer was used to investigate the role of integrin β3 in hypoxia-induced cardiomyocyte apoptosis. Confocal microscopy was used to detect the localization of integrin β3 and integrin αv in cardiomyocytes. Results: A cobaltous chloride-induced hypoxic microenvironment stimulated cardiomyocyte apoptosis and increased integrin β3 expression in H9C2 cells, AC16 cells, and cardiac tissue from acute and chronic heart failure rats. The overexpression of integrin β3 promoted cardiomyocyte proliferation, whereas silencing integrin β3 expression resulted in decreased cell proliferation in vitro. Furthermore, knocking down integrin β3 expression using shRNA or the integrin β3 inhibitor cilengitide exacerbated cobaltous chloride-induced cardiomyocyte apoptosis, whereas overexpression of integrin β3 weakened cobaltous chloride-induced cardiomyocytes apoptosis. We found that integrin β3 promoted cardiomyocytes proliferation through the regulation of the PTEN/Akt/mTOR and ERK1/2 signaling pathways. In addition, we found that knockdown of integrin αv or integrin β1 weakened the effect of integrin β3 in cardiomyocyte proliferation. Conclusion: Our findings revealed the molecular mechanism of the role of integrin β3 in cardiomyocyte proliferation and hypoxia-induced cardiomyocyte apoptosis, providing new insights into the mechanisms underlying myocardial protection.

mTOR Pathway in Gastroenteropancreatic Neuroendocrine Tumor (GEP-NETs)

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) originate from neuroendocrine cells in the gastrointestinal tract. They are heterogeneous, and though initially considered rare tumors, the incidence of GEP-NENs has increased in the last few decades. Therapeutic approaches for the metastatic disease include surgery, radiological intervention by chemoembolisation, radiofrequency ablation, biological therapy in addition to somatostatin analogs, and PRRT therapy (177Lu-DOTATATE). The PI3K-AKT-mTOR pathway is essential in the regulation of protein translation, cell growth, and metabolism. Evidence suggests that the mTOR pathway is involved in malignant progression and resistance to treatment through over-activation of several mechanisms. PI3K, one of the main downstream of the Akt-mTOR axis, is mainly involved in the neoplastic process. This pathway is frequently deregulated in human tumors, making it a central target in the development of new anti-cancer treatments. Recent molecular studies identify potential targets within the PI3K/Akt/mTOR pathway in GEP-NENs. However, the use of target therapy has been known to lead to resistance due to several mechanisms such as feedback activation of alternative pathways, inactivation of protein kinases, and deregulation of the downstream mTOR components. Therefore, the specific role of targeted drugs for the management of GEP-NENs is yet to be well-defined. The variable clinical presentation of advanced neuroendocrine tumors is a significant challenge for designing studies. This review aims to highlight the role of the PI3K/Akt/mTOR pathway in the development of neuroendocrine tumors and further specify its potential as a therapeutic target in advanced stages.

Etlingera pavieana extract attenuates TNF-α induced vascular adhesion molecule expression in human endothelial cells through NF-κB and Akt/JNK pathways

The aim of this study was to determine whether ethanol extracts of Etlingera pavieana rhizomes (EPE) can inhibit the expression of ICAM-1 and VCAM-1 in TNF-α-stimulated human vascular endothelial cells. EPE significantly reduced ICAM-1 and VCAM-1 expression in a concentration-dependent manner. EPE also suppressed phospho-IκB level and nuclear translocation of NF-κB. EPE significantly inhibited phosphorylation of JNK and c-Jun, a major component of AP-1, but had no effects on ERK and p38 MAPK pathways. Akt phosphorylation was increased in the presence of EPE, and wortmannin and SP600125 reversed the inhibitory effects of EPE on ICAM-1 and VCAM-1 expression. Furthermore, the active EPE constituents 4-methoxycinnamyl p-coumarate and trans-4-methoxycinnamaldehyde attenuated TNF-α-induced expression of ICAM-1 and VCAM-1. Taken together, our data indicate that EPE protects against vascular inflammation in endothelial cells, in part via NF-κB and Akt/JNK signalings. In future studies, E. pavieana may be developed as a therapeutic agent or dietary supplement for treating and preventing inflammatory diseases.

Combination of KRAS gene silencing and PI3K inhibition for ovarian cancer treatment

The phosphoinositide 3-kinase (PI3K) and RAS signaling pathways are frequently co-activated and altered during oncogenesis. Owing to their regulatory cross-talk, the early attempts of targeting only one pathway have mostly ended up promoting the development of drug resistance. Here, we propose using small interfering RNA (siRNA) therapeutics to directly target the undruggable KRAS (siKRAS) in combination with the pan-PI3K inhibitor GDC-0941 (GDC) to simultaneously block both PI3K and RAS signaling, thereby exerting synergistic anti-tumor effects on ovarian cancers with PTEN deficiency and KRAS^G12D mutation. For successful delivery of siKRAS, tGC/psi-nanoparticle formulation of polymerized siRNA and thiol-modified glycol chitosan nanoparticle-was used for KRAS specific inhibition in vitro and in vivo. GDC or siKRAS monotherapy each impede downstream signaling, leading to some delay in cell proliferation and migration. When combined, however, they engender much higher inhibition of PI3K signaling and stimulation of apoptosis in an ovarian allograft model compared to monotherapies. Our results show the feasibility of developing new combination strategies for the management of multiple oncogenic mutations activating PI3K and RAS signaling.

Ginsenoside Rb1, A Major Saponin from Panax ginseng, Exerts Protective Effects Against Acetaminophen-Induced Hepatotoxicity in Mice

Acute liver injury (ALI) induced by acetaminophen (APAP) is the main cause of drug-induced liver injury. Previous reports indicated liver failure could be alleviated by saponins (ginsenosides) from Panax ginseng against APAP-induced inflammatory responses in vivo. However, validation towards ginsenoside Rb1 as a major and marker saponin may protect liver from APAP-induced ALI and its mechanisms are poorly elucidated. In this study, the protective effects and the latent mechanisms of Rb1 action against APAP-induced hepatotoxicity were investigated. Rb1 was administered orally with 10mg/kg and 20mg/kg daily for 1 week before a single injection of APAP (250mg/kg, i.p.) 1h after the last treatment of Rb1. Serum alanine/aspartate aminotransferases (ALT/AST), liver glutathione (GSH) depletion, as well as the inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), were analyzed to indicate the underlying protective effects of Rb1 against APAP-induced hepatotoxicity with significant inflammatory responses. Histological examination further proved Rb1's protective effects. Importantly, Rb1 mitigated the changes in the phosphorylation of MAPK and PI3K/Akt, as well as its downstream factor NF-κB. In conclusion, experimental data clearly demonstrated that Rb1 exhibited a remarkable liver protective effect against APAP-induced ALI, partly through regulating MAPK and PI3K/Akt signaling pathways-mediated inflammatory responses.

PSORI-CM02 ameliorates psoriasis in vivo and in vitro by inducing autophagy via inhibition of the PI3K/Akt/mTOR pathway

BACKGROUND

Psoriasis is an inflammatory skin disease that affects an estimated 3% of the world's population. PSORI-CM02 is an empirically developed Chinese medicine formula optimised from Yin Xie Ling, summarised by national medical master Guo-Wei Xuan, that has been used for decades to treat psoriasis in the Guangdong Provincial Hospital of Chinese Medicine. However, its anti-psoriatic mechanisms are still poorly understood. In this study, we explored the effects of PSORI-CM02 on autophagy and the underlying mechanisms in TNF-α-stimulated HaCaT cells and in a mouse model of imiquimod-induced psoriasis.

METHODS

Cell viability was assessed by MTT assay. Apoptosis was detected by annexin V-FITC/PI double-staining and caspase-3 assays. Autophagy was detected by electron microscopy, RT-PCR and western blotting. The PI3K/Akt/mTOR pathway was analysed by western blotting and immunochemical analysis.

RESULTS

PSORI-CM02 induced autophagy and thus inhibited the proliferation of HaCaT cells via suppression of the PI3K/Akt/mTOR pathway. In mice with IMQ-induced psoriasis, PSORI-CM02 relieved psoriasis symptoms, induced autophagy and inhibited the phosphorylation of the PI3K/AKT/mTOR pathway in the skin.

CONCLUSION

These results suggest that PSORI-CM02 treats psoriasis by inducing autophagy via inhibition of the PI3K/Akt/mTOR pathway.

Co-targeting PI3K/Akt and MAPK/ERK pathways leads to an enhanced antitumor effect on human hypopharyngeal squamous cell carcinoma

PURPOSE

The present study aims to determine whether co-targeting PI3K/Akt and MAPK/ERK pathways in human hypopharyngeal squamous cell carcinoma (HSCC) is a potential anticancer strategy.

METHODS

We retrospectively analyzed the clinical data of HSCC patients, and the phosphorylation status of Akt and Erk in HSCC and tumor adjacent tissues was evaluated by immunohistochemistry. MTT and colony formation assay were performed to determine the anti-proliferative effect of PI3K/mTOR inhibitor GDC-0980 and MEK inhibitor Refametinib on HSCC cell line Fadu. Wound-healing and Transwell migration assay were used to analyze the anti-migrative capability of the two drugs. The involved anti-tumor mechanism was explored by flow cytometry, qRT-PCR and western blot. The combinational anticancer effect of GDC-0980 and Refametinib was evaluated according to Chou and Talalay's method.

RESULTS

The levels of p-Akt and p-Erk were increased significantly with the progression of clinical stage of HSCC, suggesting PI3K/Akt and MAPK/ERK pathways might be associated with HSCC occurrence and progression. Furthermore, both GDC-0980 and Refametinib showed obvious antitumor effects on FaDu cells. Treatment by the two drugs arrested FaDu cell cycle progression in G1 phase, with reduction of cyclin D1 and p-Rb, in contrast to enhancement of p27. GDC-0980 inhibited FaDu cell migration and reduced metastasis related proteins including p-PKCζ, p-Integrin β1 and uPA. Combination use of GDC-0980 and Refametinib exhibited strong synergistic anti-tumor effect.

CONCLUSION

Dual inhibition of PI3K/Akt and MAPK/ERK pathway by GDC-0980 and Refametinib might be a promising treatment strategy for HSCC patients.

Quantifying Risk Pathway Crosstalk Mediated by miRNA to Screen Precision drugs for Breast Cancer Patients

Breast cancer has become the most common cancer that leads to women's death. Breast cancer is a complex, highly heterogeneous disease classified into various subtypes based on histological features, which determines the therapeutic options. System identification of effective drugs for each subtype remains challenging. In this work, we present a computational network biology approach to screen precision drugs for different breast cancer subtypes by considering the impact intensity of candidate drugs on the pathway crosstalk mediated by miRNAs. Firstly, we constructed and analyzed the subtype-specific risk pathway crosstalk networks mediated by miRNAs. Then, we evaluated 36 Food and Drug Administration (FDA)-approved anticancer drugs by quantifying their effects on these subtype-specific pathway crosstalk networks and combining with survival analysis. Finally, some first-line treatments of breast cancer, such as Paclitaxel and Vincristine, were optimized for each subtype. In particular, we performed precision screening of subtype-specific therapeutic drugs and also confirmed some novel drugs suitable for breast cancer treatment. For example, Sorafenib was applicable for the basal subtype treatment, Irinotecan was optimum for Her2 subtype treatment, Vemurafenib was suitable for the LumA subtype treatment, and Vorinostat could apply to LumB subtype treatment. In addition, the mechanism of these optimal therapeutic drugs in each subtype of breast cancer was further dissected. In summary, our study offers an effective way to screen precision drugs for various breast cancer subtype treatments. We also dissected the mechanism of optimal therapeutic drugs, which may provide novel insight into the precise treatment of cancer and promote researches on the mechanisms of action of drugs.

Pharmacological inhibition of the MEK5/ERK5 and PI3K/Akt signaling pathways synergistically reduces viability in triple-negative breast cancer

Triple-negative breast cancers (TNBCs) represent 15% to 20% of all breast cancers and are often associated with poor prognosis. The lack of targeted therapies for TNBCs contributes to higher mortality rates. Aberrations in the phosphoinositide-3-kinase (PI3K) and mitogen-activated protein kinase pathways have been linked to increased breast cancer proliferation and survival. It has been proposed that these survival characteristics are enhanced through compensatory signaling and crosstalk mechanisms. While the crosstalk between PI3K and extracellular signal-regulated kinase 1/2 (ERK1/2) pathways has been characterized in several systems, new evidence suggests that MEK5/ERK5 signaling is a key component in the proliferation and survival of several aggressive cancers. In this study, we examined the effects of dual inhibition of PI3K/protein kinase B (Akt) and MEK5/ERK5 in the MDA-MB-231, BT-549, and MDA-MB-468 TNBC cell lines. We used the Akt inhibitor ipatasertib, ERK5 inhibitors XMD8-92 and AX15836, and the novel MEK5 inhibitor SC-1-181 to investigate the effects of dual inhibition. Our results indicated that dual inhibition of PI3K/Akt and MEK5/ERK5 signaling was more effective at reducing the proliferation and survival of TNBCs than single inhibition of either pathway alone. In particular, a loss of Bad phosphorylation at two distinct sites was observed with dual inhibition. Furthermore, the inhibition of both pathways led to p21 restoration, decreased cell proliferation, and induced apoptosis. In addition, the dual inhibition strategy was determined to be synergistic in MDA-MB-231 and BT-549 cells and was relatively nontoxic in the nonneoplastic MCF-10 cell line. In summary, the results from this study provide a unique prospective into the utility of a novel dual inhibition strategy for targeting TNBCs.

Hypoxia-induced Downregulation of SRC-3 Suppresses Trophoblastic Invasion and Migration Through Inhibition of the AKT/mTOR Pathway: Implications for the Pathogenesis of Preeclampsia

Preeclampsia (PE) is characterized by poor placentation, consequent on aberrant extravillous trophoblast (EVT) cell function during placental development. The SRC family of proteins is important during pregnancy, especially SRC-3, which regulates placental morphogenesis and embryo survival. Although SRC-3 expression in mouse trophoblast giant cells has been documented, its role in the functional regulation of extravillous trophoblasts and the development of PE remains unknown. This study found that SRC-3 expression was significantly lower in placentas from PE pregnancies as compared to uncomplicated pregnancies. Additionally, both CoCl₂-mimicked hypoxia and suppression of endogenous SRC-3 expression by lentivirus short hairpin RNA attenuated the migration and invasion abilities of HTR-8/SVneo cells. Moreover, we demonstrated that SRC-3 physically interacts with AKT to regulate the migration and invasion of HTR-8 cells, via the AKT/mTOR pathway. We also found that the inhibition of HTR-8 cell migration and invasion by CoCl₂-mimicked hypoxia was through the SRC-3/AKT/mTOR axis. Our findings indicate that, in early gestation, accumulation of HIF-1α inhibits the expression of SRC-3, which impairs extravillous trophoblastic invasion and migration by directly interacting with AKT. This potentially leads to insufficient uterine spiral artery remodeling and placental hypoperfusion, and thus the development of PE.

BRD4 inhibitor and histone deacetylase inhibitor synergistically inhibit the proliferation of gallbladder cancer in vitro and in vivo

Gallbladder cancer (GBC) is the most common malignancy of the bile duct and has a high mortality rate. Here, we demonstrated that BRD4 inhibitor JQ1 and histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) synergistically inhibited the GBC cells in vitro and in vivo. Our results showed that cotreatment with JQ1 and SAHA significantly inhibited proliferation, cell viability and metastasis, and induced apoptosis and G2/M arrest in GBC cells, with only minor effects in benign cells. In vivo, tumor volumes and weights of GBC xenograft models were significantly decreased after treatment with JQ1 or SAHA; meanwhile, the cotreatment showed the strongest effect. Further study indicated that the above anticancer effects was associated with the downregulation of BRD4 and suppression of PI3K/AKT and MAPK/ERK pathways. These findings highlight JQ1 and SAHA as potential therapeutic agents and their combination as a promising therapeutic strategy for GBC.

Ishige okamurae Extract Ameliorates the Hyperglycemia and Body Weight Gain of db/db Mice through Regulation of the PI3K/Akt Pathway and Thermogenic Factors by FGF21

Type 2 diabetes mellitus and related metabolic disorders, such as dyslipidemia, present increasing challenges to health worldwide, as a result of urbanization, the increasing prevalence of obesity, poor lifestyle, and other stress-related factors. Ishige okamurae extract (IOE) is known to be effective at lowering blood glucose and ameliorating metabolic disease. However, detailed mechanisms for these effects have yet to be elucidated. Here, we show that IOE ameliorates substrate (IRS)/ phosphatidylinositol 3-kinase (PI3K)/Akt pathway and increasing glucose transporter 4 (GLUT4) expression in skeletal muscle and white adipose tissue (WAT). We also demonstrate that IOE increases the expression of fibroblast growth factor (FGF)21, a regulator of glucose and energy metabolism in muscle and WAT. In addition, IOE administration increased peroxisome proliferator-activated receptor γ coactivator 1α expression, which regulates expression of the key thermogenic molecule uncoupling protein 1 in WAT. Thus, the effects of IOE to ameliorate hyperglycemia and adiposity may be mediated through FGF21 activating insulin signaling and increasing the expression of GLUT4 and pro-thermogenic factors.

Mechanisms of resistance to a PI3K inhibitor in gastrointestinal stromal tumors: an omic approach to identify novel druggable targets

Background: Gastrointestinal stromal tumors (GISTs) represent a worldwide paradigm of target therapy. The introduction of tyrosine kinase inhibitors has deeply changed the prognosis of GIST patients, however, the majority of them acquire secondary mutations and progress. Unfortunately, besides tyrosine-kinase inhibitors, no other therapeutic options are available. Therefore, it is mandatory to identify novel molecules and/or strategies to overcome the inevitable resistance. In this context, after promising preclinical data on the novel PI3K inhibitor BYL719, the NCT01735968 trial in GIST patients who had previously failed treatment with imatinib and sunitinib started. BYL719 has attracted our attention, and we comprehensively characterized genomic and transcriptomic changes taking place during resistance.

Methods: For this purpose, we generated two in vitro GIST models of acquired resistance to BYL719 and performed an omic-based analysis by integrating RNA-sequencing, miRNA, and methylation profiles in sensitive and resistant cells.

Results: We identified novel epigenomic mechanisms of pharmacological resistance in GISTs suggesting the existence of pathways involved in drug resistance and alternatively acquired mutations. Therefore, epigenomics should be taken into account as an alternative adaptive mechanism.

Conclusion: Despite the fact that currently we do not have patients in treatment with BYL719 to verify this hypothesis, the most intriguing result is the involvement of H19 and PSTA1 in GIST resistance, which might represent druggable targets.

Activation of Insulin Signaling in Adipocytes and Myotubes by Sarcopoterium Spinosum Extract

Sarcopoterium spinosum (S. spinosum) is a medicinal plant, traditionally used as an antidiabetic remedy. Previous studies demonstrated its beneficial properties in the treatment of insulin resistance. The aim of this study was to further clarify the effect of S. spinosum extract (SSE) on insulin signaling. Phosphoproteomic analysis, performed in 3T3-L1 adipocytes treated with SSE, revealed the activation of insulin receptor pathways. SSE increased Glut4-facilitated glucose uptake in adipocytes, with an additive effect between SSE and insulin. While the maximal effect of insulin on glucose uptake was found at days 15–16 of differentiation, SSE-induced glucose uptake was found at an earlier stage of differentiation. Inhibition of PI3K and Akt blocked SSE-dependent glucose uptake. Western blot analysis, performed on 3T3-L1 adipocytes and L6 myotubes, showed that in contrast to insulin action, Akt was only marginally phosphorylated by SSE. Furthermore, GSK3β and PRAS40 phosphorylation as well as glucose uptake were increased by the extract. SSE also induced the phosphorylation of ERK similar to insulin. In conclusion, SSE activates insulin signaling, although the upstream event mediating its effects should be further clarified. Identifying the active molecules in SSE may lead to the development of new agents for the treatment of insulin resistance.

Physcion Synergistically Enhances the Cytotoxicity of Sorafenib in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common human malignancy. Physcion is a naturally occurring anthraquinone derivative found in plant and marine sources. Our previous studies have indicated that physcion could suppress tumor growth and induce apoptosis in HCC. This study was aimed to investigate the effect of a combination of physcion and sorafenib on HCC. Our findings indicated that physcion could significantly augment the antiproliferative and proapoptotic activities of sorafenib in vitro and in vivo. Mechanistically, the synergistic effect correlates with physcion-induced suppression of Notch3/AKT signaling. This preclinical evidence highlights the potential application of physcion in the treatment of HCC. Anat Rec, 302:2171-2177, 2019. © 2019 American Association for Anatomy.

Regulation of RhoB Gene Expression during Tumorigenesis and Aging Process and Its Potential Applications in These Processes

RhoB, a member of the Ras homolog gene family and GTPase, regulates intracellular signaling pathways by interfacing with epidermal growth factor receptor (EGFR), Ras, and phosphatidylinositol 3-kinase (PI3K)/Akt to modulate responses in cellular structure and function. Notably, the EGFR, Ras, and PI3K/Akt pathways can lead to downregulation of RhoB, while simultaneously being associated with an increased propensity for tumorigenesis. Functionally, RhoB, part of the Rho GTPase family, regulates intracellular signaling pathways by interfacing with EGFR, RAS, and PI3K/Akt/mammalian target of rapamycin (mTOR), and MYC pathways to modulate responses in cellular structure and function. Notably, the EGFR, Ras, and PI3K/Akt pathways can lead to downregulation of RhoB, while simultaneously being associated with an increased propensity for tumorigenesis. RHOB expression has a complex regulatory backdrop consisting of multiple histone deacetyltransferase (HDACs 1 and 6) and microRNA (miR-19a, -21, and -223)-mediated mechanisms of modifying expression. The interwoven nature of RhoB’s regulatory impact and cellular roles in regulating intracellular vesicle trafficking, cell motion, and the cell cycle lays the foundation for analyzing the link between loss of RhoB and tumorigenesis within the context of age-related decline in RhoB. RhoB appears to play a tissue-specific role in tumorigenesis, as such, uncovering and appreciating the potential for restoration of RHOB expression as a mechanism for cancer prevention or therapeutics serves as a practical application. An in-depth assessment of RhoB will serve as a springboard for investigating and characterizing this key component of numerous intracellular messaging and regulatory pathways that may hold the connection between aging and tumorigenesis.

Cytochalasin H Inhibits Angiogenesis via the Suppression of HIF-1α Protein Accumulation and VEGF Expression through PI3K/AKT/P70S6K and ERK1/2 Signaling Pathways in Non-Small Cell Lung Cancer Cells

Our previous study has demonstrated that cytochalasin H (CyH) isolated from mangrove-derived endophytic fungus induces apoptosis and inhibits migration in A549 non-small cell lung cancer (NSCLC) cells. In this study, we further explored the effect of CyH on angiogenesis in NSCLC cells and the underlying molecular mechanisms. A549 and H460 NSCLC cells were treated with different concentrations of CyH for 24 h. The effects of CyH on NSCLC angiogenesis in vitro and in vivo were investigated. Hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression in xenografted NSCLC of nude mice was analyzed by immunohistochemistry. ELISA was used to analyze the concentration of VEGF in the conditioned media derived from treated and untreated NSCLC cells. Western blot was performed to detect the levels of HIF-1α, p-AKT, p-P70S6K, and p-ERK1/2 proteins, and RT-qPCR was used to determine the levels of HIF-1α and VEGF mRNA in A549 and H460 cells. Our results showed that CyH significantly inhibited angiogenesis in vitro and in vivo, and suppressed the hemoglobin content and HIF-1α and VEGF protein expression in xenografted NSCLC tissues of nude mice. Meanwhile, CyH inhibited the secretion of VEGF protein and the expression of HIF-1α protein in A549 and H460 cells. Moreover, CyH had a significant inhibitory effect on VEGF mRNA expression but had no effect on HIF-1α mRNA expression, and CyH inhibited HIF-1α protein expression by promoting the degradation of HIF-1α protein in A549 and H460 cells. Additionally, CyH dramatically inhibited AKT, P70S6K, and ERK1/2 activation in A549 and H460 cells. Taken together, our results suggest that CyH can inhibit NSCLC angiogenesis by the suppression of HIF-1α protein accumulation and VEGF expression through PI3K/AKT/P70S6K and ERK1/2 signaling pathways.

Involvement of miR-770-5p in trastuzumab response in HER2 positive breast cancer cells

miRNAs may play effective roles in breast cancer so modulating their expression levels could have therapeutic benefits. Recent studies have found the combination of miRNA-based therapeutics with conventional drugs as promising. This study aimed to find drug-responsive miRNAs, and explore their anticancer activities in HER2+ breast cancer cells and regulatory role in the trastuzumab response. qRT-PCR-array analysis was performed with effective concentrations of tamoxifen and trastuzumab treated BT-474, SK-BR-3 and MCF-7 cells. Motility and invasion analyses were performed with wound healing and xCELLigence impedance-based assays respectively. Viability of cells following mimic transfection and drug treatment was assessed by WST-1 assay. Western blot analysis was used to assess miR-770-5p regulation of proteins and their phosphorylated forms. The clinical relevance of miR-770-5p was examined by TCGA data analysis. The qRT-PCR-array results indicated that miR-770-5p was responsive in a drug and cell line independent manner. Overexpression of miR-770-5p inhibited the motility and cell invasion through regulation of AKT and ERK proteins. Additionally, miR-770-5p potentiated the effectiveness of trastuzumab. Thus, regulating the expression level of miR-770-5p in combination with trastuzumab treatment may simultaneously inhibit the downstream elements of PI3K and MAPK signalling, thereby blocking the proliferation, motility and invasion capacities of HER2+ breast cancer cells.

The Expression of Key Guidance Genes at a Forebrain Axon Turning Point Is Maintained by Distinct Fgfr Isoforms but a Common Downstream Signal Transduction Mechanism

During development the axons of neurons grow toward and locate their synaptic partners to form functional neural circuits. Axons do so by reading a map of guidance cues expressed by surrounding tissues. Guidance cues are expressed at a precise space and time, but how guidance cue expression is regulated, and in a coordinated manner, is poorly understood. Semaphorins (Semas) and Slits are families of molecular ligands that guide axons. We showed previously that fibroblast growth factor (Fgf) signaling maintains sema3a and slit1 forebrain expression in Xenopus laevis, and these two repellents cooperate to guide retinal ganglion cell (RGC) axons away from the mid-diencephalon and on towards the optic tectum. Here, we investigate whether there are common features of the regulatory pathways that control the expression of these two guidance cues at this single axon guidance decision point. We isolated the sema3a proximal promoter and confirmed its responsiveness to Fgf signaling. Through misexpression of truncated Fgf receptors (Fgfrs), we found that sema3a forebrain expression is dependent on Fgfr2-4 but not Fgfr1. This is in contrast to slit1, whose expression we showed previously depends on Fgfr1 but not Fgfr2-4. Using pharmacological inhibitors and misexpression of constitutively active (CA) and dominant negative (DN) signaling intermediates, we find that while distinct Fgfrs regulate these two guidance genes, intracellular signaling downstream of Fgfrs appears to converge along the phosphoinositol 3-kinase (PI3K)-Akt signaling pathway. A common PI3K-Akt signaling pathway may allow for the coordinated expression of guidance cues that cooperate to direct axons at a guidance choice point.

Revealing hub pathway cross-talk for premature newborns with bronchopulmonary dysplasia by the integration of pathway analysis and Monte Carlo Cross-Validation

The objective of this study was to reveal hub pathway cross-talk for premature newborns with bronchopulmonary dysplasia (BPD) based on the pathway enrichment analysis and Monte Carlo Cross-Validation (MCCV) method. The inference of key pathway cross-talk consisted of four parts: i) Identifying differentially expressed genes (DEGs); ii) detecting differentially expressed pathways (DEPs); iii) computing discriminating score (DS) for each pair of DEPs or cross-talk and investigating seed cross-talk through the random forest (RF) algorithm and iv) extracting hub cross-talk dependent on the MCCV method. The results showed that a total of 132 DEGs and 137 DEPs were obtained across BPD patients and normal controls. Using the DS and RF algorithm, 10 seed DEP cross-talk were detected. By conducting the MCCV on seed cross-talk, 3 hub cross-talk for BPD were uncovered: i) The pair of pathways role of interleukin-17F (IL-17F) in allergic inflammatory airway diseases and role of IL-17A in psoriasis; ii) the pair of pathways role of IL random forest 17A in psoriasis and IL-17A signaling in fibroblasts and ii) the pair of pathways IL-17A signaling in airway cells and role of hypercytokinemia/hyperchemokinemia in the pathogenesis of influenza. These 3 hub cross-talk among DEPs might give an insight to reveal the molecular mechanism underlying the premature newborns with BPD.

Targeting Receptor Kinases in Colorectal Cancer

Colorectal cancer is the third most common malignancy in men and the second most common cancer in women. Despite the success of screening programs and the development of adjuvant therapies, the global burden of colorectal cancer is expected to increase by 60% to more than 2.2 million new cases and 1.1 million deaths by 2030. In recent years, a great effort has been made to demonstrate the utility of protein kinase inhibitors for cancer treatment. Considering this heterogeneous disease is defined by mutations that activate different Receptor Tyrosine Kinases (RTKs) and affect downstream components of RTK-activated transduction pathways, in this review we analyze the potential utility of different kinase inhibitors for colorectal cancer treatment.

β-Thujaplicin induces autophagic cell death, apoptosis, and cell cycle arrest through ROS-mediated Akt and p38/ERK MAPK signaling in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a common liver malignancy worldwide, has high morbidity and mortality. β-Thujaplicin, a tropolone derivative, has been used in some health-care products and clinical adjuvant drugs, but its use for HCC is unknown. In this study, we found that β-Thujaplicin inhibits the growth of HCC cells, but not normal liver cells, with nanomolar potency. Mechanistically, we found that β-Thujaplicin could induce autophagy, as judged by western blot, confocal microscopy, and transmission electron microscopy. Further using β-Thujaplicin combined with an autophagy blocker or agonist treatment HepG2 cells, we found that β-Thujaplicin induced autophagic cell death (ACD) mediated by ROS caused inhibition of the Akt-mTOR signaling pathway. Moreover, β-Thujaplicin triggered HepG2 apoptosis and increased cleaved PARP1, cleaved caspase-3, and Bax/Bcl-2 ratio, which indicated that β-Thujaplicin induced apoptosis mediated by the mitochondrial-dependent pathway. We also found that increased expression of p21 and decreased expression of CDK7, Cyclin D1, and Cyclin A2 participating in β-Thujaplicin caused the S-phase arrest. It seems that β-Thujaplicin exerts these functions by ROS-mediated p38/ERK MAPK but not by JNK signaling pathway activation. Consistent with in vitro findings, our in vivo study verified that β-Thujaplicin treatment significantly reduced HepG2 tumor xenograft growth. Taken together these findings suggest that β-Thujaplicin have an ability of anti-HCC cells and may conducively promote the development of novel anti-cancer agents.

Glycyrrhetinic Acid Improves Insulin-Response Pathway by Regulating the Balance between the Ras/MAPK and PI3K/Akt Pathways

Glycyrrhetinic acid (GA), a bioactive component in the human diet, has been reported to improve hyperglycemia, dyslipidemia, insulin resistance and obesity in rats with metabolic syndrome. However, GA-specific target proteins and the mechanisms involved in the downstream signaling and cross-talk to improve insulin sensitivity have not been fully elucidated. In this study, the potential targets of GA were identified by chemical proteomics strategies using serial GA probes for target fishing and cell molecular imaging. Intracellular enzyme activity evaluation and insulin resistance models were used for validating the function of the target proteins on the downstream insulin signaling pathways. Collectively, our data demonstrate that GA improved the insulin-responsive pathway and glucose consumption levels via multiple diabetogenic factors that activated the insulin signaling pathway in HepG2 cells. GA improved Glucose transporter 4(GLUT4) expression by targeting the Ras protein to regulate the mitogen-activated protein kinase (MAPK) pathway. GA exhibited a strong inhibitory effect on IRS1ser307 phosphorylation in cells treated with the Protein kinase C (PKC) activator Phorbol 12-myristate 13-acetate (PMA.) Consistently, IRS1ser307 phosphorylation was also inhibited by GA in Free fatty acid (FFA)-treated HepG2 cells. GA also inhibited the PMA-induced phosphorylation of IκB kinase α/β (IKKα/β), c-Jun N-terminal kinase (JNK) and p38 proteins (P38), suggesting that IKKα/β, JNK and P38 activation is dependent on PKC activity.

Effect of miR‑145 on gastric cancer cells

Gastric cancer is one of the most common malignant tumors in the world. Due to the lack of early diagnosis and effective treatment, the outcome of treatment and prognosis is poor. MicroRNA-145 (miR-145) is downregulated in various cancer types. In the present study, miR-145 expression was detected by reverse transcription-quantitative polymerase chain reaction in gastric cancer cell lines and normal gastric epithelial cells. The function of miR-145 in the gastric cancer cell line SGC-7901 was investigated. The present results demonstrated that the expression of miR-145 was downregulated in gastric cancer cells. Further analysis identified that upregulation of miR-145 significantly suppressed SGC-7901 cell proliferation, increased cellular apoptosis and blocked the cell cycle in the G₁ phase. Additionally, overexpression of miR-145 reduced SGC-7901 cell invasion and metastasis in vitro. Western blot analysis demonstrated that overexpression of miR-145 downregulated Myc proto-oncogene protein, phosphoinositide 3-kinase/protein kinase B and matrix metalloproteinase 2/9, and upregulated p21 in SGC-7901 cells. The present results revealed potential signaling pathways that miR-145 may use to regulate gastric cancer cell proliferation, apoptosis and metastasis. Collectively, the present results suggest that miR-145 is a tumor suppressor for gastric cancer and it may be a potential therapeutic target for gastric cancer treatment.

Quantitative Measurement of Functional Activity of the PI3K Signaling Pathway in Cancer

The phosphoinositide 3-kinase (PI3K) growth factor signaling pathway plays an important role in embryonic development and in many physiological processes, for example the generation of an immune response. The pathway is frequently activated in cancer, driving cell division and influencing the activity of other signaling pathways, such as the MAPK, JAK-STAT and TGFβ pathways, to enhance tumor growth, metastasis, and therapy resistance. Drugs that inhibit the pathway at various locations, e.g., receptor tyrosine kinase (RTK), PI3K, AKT and mTOR inhibitors, are clinically available. To predict drug response versus resistance, tests that measure PI3K pathway activity in a patient sample, preferably in combination with measuring the activity of other signaling pathways to identify potential resistance pathways, are needed. However, tests for signaling pathway activity are lacking, hampering optimal clinical application of these drugs. We recently reported the development and biological validation of a test that provides a quantitative PI3K pathway activity score for individual cell and tissue samples across cancer types, based on measuring Forkhead Box O (FOXO) transcription factor target gene mRNA levels in combination with a Bayesian computational interpretation model. A similar approach has been used to develop tests for other signaling pathways (e.g., estrogen and androgen receptor, Hedgehog, TGFβ, Wnt and NFκB pathways). The potential utility of the test is discussed, e.g., to predict response and resistance to targeted drugs, immunotherapy, radiation and chemotherapy, as well as (pre-) clinical research and drug development.