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Cell Cycle (Georgetown, Tex.) Apr 2023This study aimed to explore the role of lipopolysaccharide-binding protein (LBP) in adipose browning. Mouse embryonic fibroblasts (MEFs) were treated with...
Deficiency of lipopolysaccharide binding protein facilitates adipose browning, glucose uptake and oxygen consumption in mouse embryonic fibroblasts via activating PI3K/Akt/mTOR pathway and inhibiting autophagy.
This study aimed to explore the role of lipopolysaccharide-binding protein (LBP) in adipose browning. Mouse embryonic fibroblasts (MEFs) were treated with differentiation induction reagents and Perifosine (Akt inhibitor), with the transfection of Atg5, short hairpin RNA targeting LBP (shLBP), and Atg5 (shAtg5). The expression levels of LBP, inflammatory markers , brown fat markers, lipid metabolism marker, autophagy markers, insulin signaling-related molecules , p-mTOR, mTOR, p-Akt, Akt, p-PI3K, and PI3K were quantified or determined by Western blot, qRT-PCR, and immunofluorescence assay. The formation of lipid was examined through Oil red O staining assay. The consumption of oxygen was assessed using a Seahorse XF96 analyzer, and the uptake of glucose was evaluated by [H]-2-deoxy-D-glucose uptake assay. Deficiency of LBP promoted adipose browning, oxygen consumption, glucose uptake, and insulin sensitivity in differentiated MEFs, where it inhibited inflammation and autophagy. All of the effects above were reversed by Atg5 overexpression. Meanwhile, the knockdown of Atg5 strengthened the activation of PI3K/Akt/mTOR pathway induced by the depletion of LBP, while Perifosine partly reversed the activation of differentiated MEFs. The knockdown of LBP facilitated adipose browning, glucose uptake, and oxygen consumption in MEFs via the activation of PI3K/Akt/mTOR pathway and the inhibition of autophagy.
Topics: Animals; Mice; Autophagy; Fibroblasts; Glucose; Lipopolysaccharides; Obesity; Oxygen Consumption; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; TOR Serine-Threonine Kinases
PubMed: 36710409
DOI: 10.1080/15384101.2023.2169521 -
Scientific Reports Mar 2017Metabolic reprogramming is a hallmark of cancer development, mediated by genetic and epigenetic alterations that may be pharmacologically targeted. Among oncogenes, the...
Metabolic reprogramming is a hallmark of cancer development, mediated by genetic and epigenetic alterations that may be pharmacologically targeted. Among oncogenes, the kinase Akt is commonly overexpressed in tumors and favors glycolysis, providing a rationale for using Akt inhibitors. Here, we addressed the question of whether and how inhibiting Akt activity could improve therapy of non-small cell lung cancer (NSCLC) that represents more than 80% of all lung cancer cases. First, we demonstrated that Akt inhibitors interacted synergistically with Microtubule-Targeting Agents (MTAs) and specifically in cancer cell lines, including those resistant to chemotherapy agents and anti-EGFR targeted therapies. In vivo, we further revealed that the chronic administration of low-doses of paclitaxel - i.e. metronomic scheduling - and the anti-Akt perifosine was the most efficient and the best tolerated treatment against NSCLC. Regarding drug mechanism of action, perifosine potentiated the pro-apoptotic effects of paclitaxel, independently of cell cycle arrest, and combining paclitaxel/perifosine resulted in a sustained suppression of glycolytic and mitochondrial metabolism. This study points out that targeting cancer cell bioenergetics may represent a novel therapeutic avenue in NSCLC, and provides a strong foundation for future clinical trials of metronomic MTAs combined with Akt inhibitors.
Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Culture Techniques; Cell Cycle Checkpoints; Cell Line, Tumor; Disease Models, Animal; Energy Metabolism; Glycolysis; Humans; Kaplan-Meier Estimate; Lung Neoplasms; Mice; Mitochondria; Paclitaxel; Phosphorylcholine; Proto-Oncogene Proteins c-akt; Signal Transduction; Xenograft Model Antitumor Assays
PubMed: 28332584
DOI: 10.1038/srep45136 -
Oncogene Apr 2018Cancer cell migration requires that cells respond and adapt to their surroundings. In the absence of extracellular matrix cues, cancer cells will undergo a mesenchymal...
Cancer cell migration requires that cells respond and adapt to their surroundings. In the absence of extracellular matrix cues, cancer cells will undergo a mesenchymal to ameboid transition, whereas a highly confining space will trigger a switch to "leader bleb-based" migration. To identify oncogenic signaling pathways mediating these transitions, we undertook a targeted screen using clinically useful inhibitors. Elevated Src activity was found to change actin and focal adhesion dynamics, whereas inhibiting Src triggered focal adhesion disassembly and blebbing. On non-adherent substrates and in collagen matrices, amoeboid-like, blebbing cells having high Src activity formed protrusions of the plasma membrane. To evaluate the role of Src in confined cells, we use a novel approach that places cells under a slab of polydimethylsiloxane (PDMS), which is held at a defined height. Using this method, we find that leader bleb-based migration is resistant to Src inhibition. High Src activity was found to markedly change the architecture of cortical actomyosin, reduce cell mechanical properties, and the percentage of cells that undergo leader bleb-based migration. Thus, Src is a signal transducer that can potently influence transitions between migration modes with implications for the rational development of metastasis inhibitors.
Topics: Actins; Amino Acid Substitution; Butadienes; Cell Adhesion; Cell Movement; Dasatinib; Humans; Imidazoles; Mutant Proteins; Neoplasms; Nitriles; Phosphorylcholine; Protein Kinase Inhibitors; Proto-Oncogene Proteins pp60(c-src); Quinolines; Tumor Cells, Cultured
PubMed: 29379163
DOI: 10.1038/s41388-017-0071-5 -
ACS Pharmacology & Translational Science Feb 2020-amplified neuroblastoma is one of the deadliest forms of childhood cancer and remains a significant clinical challenge. Direct pharmacological inhibition of MYCN is not...
-amplified neuroblastoma is one of the deadliest forms of childhood cancer and remains a significant clinical challenge. Direct pharmacological inhibition of MYCN is not currently achievable. One strategy could be to target the AKT/GSK3β pathway, which directly regulates the stability of the MYCN protein. Numerous potent and isoform-specific small-molecule AKT inhibitors have been developed. However, the selection of the right drug combinations in the relevant indication will have a significant impact on AKT inhibitor clinical success. To maximally exploit the potential of AKT inhibitors, a better understanding of AKT isoform functions in cancer is crucial. Here using RNAi to downregulate specific AKT isoforms, we demonstrated that loss of total AKT activity rather than isoform-specific expression was necessary to decrease MYCN expression and cause a significant decrease in neuroblastoma cell proliferation. Consistent with these observations, isoform-specific pharmacological inhibition of AKT was substantially less effective than pan-AKT inhibition in combination with cytotoxic drugs in -amplified neuroblastoma. The allosteric pan-AKT inhibitor perifosine had promising and activity in combination with conventional cytotoxic drugs in -amplified neuroblastoma cells. Our results demonstrated that perifosine drug combination was able to induce apoptosis and downregulate ABC transporter expression. Collectively, this study shows that selecting pan-AKT inhibitors rather than isoform-specific drugs to synergize with first-line chemotherapy treatment should be considered for clinical trials for aggressive neuroblastoma and, potentially, other MYCN -driven cancers.
PubMed: 32259094
DOI: 10.1021/acsptsci.9b00085 -
Molecular Medicine Reports Aug 2020Vascular complications are the primary reason for disability and mortality associated with diabetes mellitus (DM), and numerous microRNAs (miRNAs/miRs) are involved in...
Vascular complications are the primary reason for disability and mortality associated with diabetes mellitus (DM), and numerous microRNAs (miRNAs/miRs) are involved in the process, such as miR‑122, miR‑24 and miR‑423. It has been reported that miR‑328 regulates DM and cardiovascular disease; however, the role and mechanism of action underlying miR‑328 in HUVECs is not completely understood. The present study aimed to investigate the role and mechanism of action underlying the effects of miR‑328 on the functions of HUVECs. To simulate hyperglycemia combined with ischemia‑induced tissue starvation, HUVECs were cultured in endothelial cell medium with 25 mmol/l D‑glucose and 2% FBS for 24 h [high glucose (HG) + 2% FBS group]. HUVEC miR‑328 expression levels were detected by reverse transcription‑quantitative PCR. Cell migration, cytotoxicity and tube‑like structure formation were analyzed using wound healing, Cell Counting Kit‑8 and tube formation assays, respectively. Following transfection with miR‑328 inhibitor, miR‑328 expression was downregulated in HUVECs. Protein expression levels were determined by western blotting. Compared with the control group, the migration and tube‑like structure formation of HUVECs were decreased, and cell cytotoxicity was increased in the HG + 2% FBS group. The protein expression levels of vascular endothelial growth factor were also decreased, and the expression levels of miRNA‑328 in the HG + 2% FBS group were increased compared with the control group. However, miRNA‑328 downregulation reversed the aforementioned effects. Further experiments indicated that the AKT signaling pathway was inhibited in the HG + 2% FBS group; however, miR‑328 downregulation activated the AKT/mTOR signaling pathway, which was blocked by the AKT signaling pathway inhibitor, perifosine. Gene prediction and western blotting demonstrated that miR‑328 displayed a regulatory role via Pim‑1 proto‑oncogene, serine/threonine kinase (PIM1). In conclusion, miR‑328 expression was upregulated and angiogenesis was inhibited when HUVECs were subjected to high glucose and low serum conditions. miR‑328 downregulation enhanced angiogenesis by increasing PIM1 expression and activating the AKT/mTOR signaling pathway in HUVECs under high glucose and low serum conditions.
Topics: Binding Sites; Cell Movement; Cell Survival; Cells, Cultured; Culture Media; Databases, Genetic; Down-Regulation; Glucose; Human Umbilical Vein Endothelial Cells; Humans; MicroRNAs; Neovascularization, Physiologic; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-pim-1; Serum; Signal Transduction; TOR Serine-Threonine Kinases; Vascular Endothelial Growth Factor A
PubMed: 32626978
DOI: 10.3892/mmr.2020.11141 -
Tumour Biology : the Journal of the... Oct 2016Brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor TrkB have been reported to be associated with poor prognosis in neuroblastoma (NB) patients....
Brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor TrkB have been reported to be associated with poor prognosis in neuroblastoma (NB) patients. Our previous studies indicated that BDNF activation of TrkB induces chemo-resistance through activation of phosphoinositide-3-kinase (PI3K)/Akt pathway. In this study, we investigated the role of BDNF/TrkB on metastasis in NB. A tetracycline-regulated TrkB-expressing NB cell line (TB3) was used. Scratch wound healing assay, Boyden chamber migration, and invasion assays were performed to study the migration and invasion of TB3 cells. A tumor xenograft model using SCID-Beige mice was utilized to detect the metastasis of NB tumors in vivo. Inhibitors of PI3K, MAPK, Akt, and mTOR were used. Western blotting was performed to study the expressions of P-Akt, P-Erk, and P-mTOR. Our results showed that in TrkB-expressing NB cells, BDNF treatment significantly increased gap closing (P < 0.01) in scratch wound healing assay, also significantly enhanced the numbers of migrating cells (P < 0.01) and invading cells (P < 0.01) in the Boyden chamber migration and invasion assays. In vivo, NB distant metastases were significantly increased in mice with TrkB-expressing xenograft tumors compared to those with non-TrkB-expressing tumors (P < 0.05). Pre-treatment with any of the inhibitors for PI3K (LY294002), MAPK (PD98059), Akt (perifosine), or mTOR (rapamycin) blocked the BDNF/TrkB-induced increases of cell migration and invasion in TB3 cells, and also blocked the BDNF/TrkB-induced expressions of P-Akt, P-Erk, and P-mTOR. These data indicated that BDNF/TrkB increased metastasis in NB via PI3K/Akt/mTOR and MAPK pathways, and BDNF/TrkB and the downstream targets may be potential targets for the treatment of NB metastasis.
PubMed: 27752996
DOI: 10.1007/s13277-016-5433-z -
Frontiers in Aging Neuroscience 2018Neuroinflammation and autophagy dysfunction are closely related to the development of neurodegeneration such as Parkinson's disease (PD). However, the role of autophagy...
Neuroinflammation and autophagy dysfunction are closely related to the development of neurodegeneration such as Parkinson's disease (PD). However, the role of autophagy in microglia polarization and neuroinflammation is poorly understood. TNF-α, which is highly toxic to dopaminergic neurons, is implicated as a major mediator of neuroinflammation in PD. In this study, we found that TNF-α resulted in an impairment of autophagic flux in microglia. Concomitantly, an increase of M1 marker (iNOS/NO, IL-1β, and IL-6) expression and reduction of M2 marker (Arginase1, Ym1/2, and IL-10) were observed in TNF-α challenged microglia. Upregulation of autophagy via serum deprivation or pharmacologic activators (rapamycin and resveratrol) promoted microglia polarization toward M2 phenotype, as evidenced by suppressed M1 and elevated M2 gene expression, while inhibition of autophagy with 3-MA or Atg5 siRNA consistently aggravated the M1 polarization induced by TNF-α. Moreover, Atg5 knockdown alone was sufficient to trigger microglia activation toward M1 status. More important, TNF-α stimulated microglia conditioned medium caused neurotoxicity when added to neuronal cells. The neurotoxicity was further aggravated when Atg5 knockdown in BV2 cells but alleviated when microglia pretreatment with rapamycin. Activation of AKT/mTOR signaling may contribute to the changes of autophagy and inflammation as the AKT specific inhibitor perifosine prevented the increase of LC3II (an autophagic marker) in TNF-α stimulated microglia. Taking together, our results demonstrate that TNF-α inhibits autophagy in microglia through AKT/mTOR signaling pathway, and autophagy enhancement can promote microglia polarization toward M2 phenotype and inflammation resolution.
PubMed: 30515090
DOI: 10.3389/fnagi.2018.00378 -
Oncotarget Mar 2015T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder in which chemotherapy resistance and refractory relapses occur, with a poorer prognostic...
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder in which chemotherapy resistance and refractory relapses occur, with a poorer prognostic outcome.Constitutively active PI3K/Akt/mTOR pathway is a common feature of T-ALL upregulating cell proliferation, survival and drug resistance. This pathway is currently under clinical trials with small molecules inhibitors (SMI).To verify whether a multi-inhibition treatment against Akt protein could enhance the efficacy of individual drug administration and overcome drug resistance as well as to obtain a decrease in single drug concentration, we tested on T-ALL cell lines the effects of combined treatments with three Akt inhibitors with different mode of action, GSK690693, MK-2206 and Perifosine.In cells with hyperactivated Akt, combined administration of the drugs displayed a significant synergistic and cytotoxic effect and affected PI3K/Akt/mTOR pathway at much lower concentration than single drug use. Highest synergistic effect for full inhibition of Akt was also related to the timing of every drug administration. Furthermore the triple treatment had greater efficacy in inducing cell cycle arrest in G0/G1 phase and both apoptosis and autophagy.Targeting Akt as a key protein of PI3K/Akt/mTOR pathway with multiple drugs might represent a new and promising pharmacological strategy for treatment of T-ALL patients.
Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Cell Cycle Checkpoints; Dose-Response Relationship, Drug; Drug Synergism; Enzyme Activation; Heterocyclic Compounds, 3-Ring; Humans; Jurkat Cells; Molecular Targeted Therapy; Oxadiazoles; Phosphatidylinositol 3-Kinase; Phosphorylation; Phosphorylcholine; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases
PubMed: 25788264
DOI: 10.18632/oncotarget.3260 -
Breast Cancer Research : BCR Feb 2017Thymosin beta 10 (TMSB10) has been demonstrated to be involved in the malignant process of many cancers. The purpose of this study was to determine the biological roles...
BACKGROUND
Thymosin beta 10 (TMSB10) has been demonstrated to be involved in the malignant process of many cancers. The purpose of this study was to determine the biological roles and clinical significance of TMSB10 in breast cancer and to identify whether TMSB10 might be used as a serum marker for the diagnosis of breast cancer.
METHODS
TMSB10 expression was evaluated by immunohistochemical analysis (IHC) of 253 breast tumors and ELISA of serum from 80 patients with breast cancer. Statistical analysis was performed to explore the correlation between TMSB10 expression and clinicopathological features in breast cancer. Univariate and multivariate Cox regression analysis were performed to examine the association between TMSB10 expression and overall survival and metastatic status. In vitro and in vivo assays were performed to assess the biological roles of TMSB10 in breast cancer. Western blotting and luciferase assays were examined to identify the underlying pathway involved in the tumor-promoting role of TMSB10.
RESULTS
We found TMSB10 was upregulated in breast cancer cells and tissues. Univariate and multivariate analysis demonstrated that high TMSB10 expression significantly correlated with clinicopathological features, poor prognosis and distant metastases in patients with breast cancer. Overexpression of TMSB10 promotes, while silencing of TMSB10 inhibits, proliferation, invasion and migration of breast cancer cells in vitro and in vivo. Our results further reveal that TMSB10 promotes the proliferation, invasion and migration of breast cancer cells via AKT/FOXO signaling, which is antagonized by the AKT kinase inhibitor perifosine. Importantly, the expression of TMSB10 is significantly elevated in the serum of patients with breast cancer and is positively associated with clinical stages of breast cancer.
CONCLUSION
TMSB10 may hold promise as a minimally invasive serum cancer biomarker for the diagnosis of breast cancer and a potential therapeutic target which will facilitate the development of a novel therapeutic strategy against breast cancer.
Topics: Biomarkers, Tumor; Breast Neoplasms; Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Female; Forkhead Transcription Factors; Humans; Kaplan-Meier Estimate; Neoplasm Metastasis; Prognosis; Proportional Hazards Models; Proto-Oncogene Proteins c-akt; Signal Transduction; Thymosin
PubMed: 28179017
DOI: 10.1186/s13058-016-0785-2 -
Oncotarget Apr 2016DDX3 plays a dual role in colorectal cancer; however, the role and underlying mechanism of DDX3 in colorectal tumorigenesis remains unclear. Here, we provide evidence...
DDX3 plays a dual role in colorectal cancer; however, the role and underlying mechanism of DDX3 in colorectal tumorigenesis remains unclear. Here, we provide evidence that DDX3 enhances oncogenic KRAS transcription via an increase in SP1 binding to its promoter. Accelerating oncogenic KRAS expression by DDX3 promotes the invasion capability via the ERK/PTEN/AKT/β-catenin cascade. Moreover, the β-catenin/ZEB1 axis is responsible for DDX3-induced cell invasiveness and xenograft lung tumor nodule formation. The xenograft lung tumor nodules induced by DDX3-overexpressing T84 stable clone were nearly suppressed by the inhibitor of AKT (perifosine) or β-catenin (XAV939). Among patients, high KRAS, positive nuclear β-catenin expression and high ZEB1 were more commonly occurred in high-DDX3 tumors than in low-DDX3 tumors. High-DDX3, high-KRAS, positive nuclear β-catenin tumors, and high-ZEB1 exhibited worse overall survival (OS) and relapse free survival (RFS) than their counterparts. In conclusion, DDX3 may play an oncogenic role to promote tumor growth and invasion in colon cancer cells via the β-catenin/ZEB1 axis due to increasing KRAS transcription. We therefore suggest that AKT or β-catenin may potentially act as a therapeutic target to improve tumor regression and outcomes in colorectal cancer patients who harbored high-DDX3 tumors.
Topics: Animals; Colorectal Neoplasms; DEAD-box RNA Helicases; Gene Expression Regulation, Neoplastic; Heterografts; Humans; Kaplan-Meier Estimate; Mice; Neoplasm Invasiveness; Proto-Oncogene Proteins p21(ras); Zinc Finger E-box-Binding Homeobox 1; beta Catenin
PubMed: 27007150
DOI: 10.18632/oncotarget.8143