Inhibition of PI3K/AKT and MAPK/ERK pathways causes activation of FOXO transcription factor, leading to cell cycle arrest and apoptosis in pancreatic cancer. J Mol Signal. 2010;5:10. [PMID: 20642839 PMCID: PMC2915986 DOI: 10.1186/1750-2187-5-10]

1,25-Dihydroxyvitamin D3 inhibits porcine epidemic diarrhea virus replication by regulating cell cycle resumption in IPEC-J2 porcine epithelial cells

Porcine epidemic diarrhea virus (PEDV) infection causes heavy economic losses in the pig industry. Currently, the lack of effective treatments prompts new antiviral researches. We have shown that 25-hydroxyvitamin D₃ supplementation alleviated PEDV infection in weaned pigs before. However, it is not clear whether vitamin D inhibits PEDV replication. In this study, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) inhibited PEDV induced mitochondria damage and cell apoptosis. In addition, 1,25(OH)₂D₃ treatment decreased PEDV nucleocapsid gene and protein levels in IPEC-J2 cells. Transcriptomic data showed that PEDV infection altered the expression of 5316 genes (2498 up, 2818 down) in IPEC-J2 cells. The differentially expressed genes were mainly involved in cell cycle process, ribonucleoprotein complex biogenesis, mitotic nuclear division, and other biological processes. Then we examined the effects of PEDV infection on cell cycle progression in IPEC-J2 cells, and the results showed that PEDV induced G0/G1 phase arrest. G0/G1-phase arrest was also conducive to PEDV replication. However, 1,25(OH)₂D₃ treatment decreased G0/G1 phase percentage induced by PEDV. Cyclin D and cyclin E mRNA expression were also increased by 1,25(OH)₂D₃ supplementation upon PEDV infection. Moreover, the regulation of 1,25(OH)₂D₃ on cell cycle progression was abrogated by ERK1/2 inhibitor, as well as the mRNA expression of cyclin D. The inhibition of 1,25(OH)₂D₃ on PEDV replication was also eliminated by ERK1/2 inhibitor. Taken together, these results demonstrated that 1,25(OH)₂D₃ supplementation inhibited PEDV replication, and the anti-virus effect of 1,25(OH)₂D₃ was mediated in part by regulating cell cycle progression through ERK1/2 signaling pathway.

Recent trends in drug-delivery systems for the treatment of diabetic retinopathy and associated fibrosis

Diabetic retinopathy is a frequent microvascular complication of diabetes and a major cause of visual impairment. In advanced stages, the abnormal neovascularization can lead to fibrosis and subsequent tractional retinal detachment and blindness. The low bioavailability of the drugs at the target site imposed by the anatomic and physiologic barriers within the eye, requires long term treatments with frequent injections that often compromise patient's compliance and increase the risk of developing more complications. In recent years, much effort has been put towards the development of new drug delivery platforms aiming to enhance their permeation, to prolong their retention time at the target site and to provide a sustained release with reduced toxicity and improved efficacy. This review provides an overview of the etiology and pathophysiology of diabetic retinopathy and current treatments. It addresses the specific challenges associated to the different ocular delivery routes and provides a critical review of the most recent developments made in the drug delivery field.

Extracts from Pulsatilla patens target cancer-related signaling pathways in HeLa cells

The purpose of this study was to determine if a methanolic extract of the Pulsatilla patens (L.) Mill. can inhibit the progression of cancer through the modulation of cancer-related metabolic signaling pathways. We analyzed a panel of 13 inducible luciferase reporter gene vectors which expression is driven by enhancer elements that bind to specific transcription factors for the evaluation of the activity of cancer signaling pathways. The root extract of P. patens exhibited strong inhibition of several signaling pathways in HeLa cells, a cervical cancer cell line, and was found to be the most potent in inhibiting the activation of Stat3, Smad, AP-1, NF-κB, MYC, Ets, Wnt and Hdghog, at a concentration of 40 µg/mL. The methanolic extracts of P. patens enhanced apoptotic death, deregulated cellular proliferation, differentiation, and progression towards the neoplastic phenotype by altering key signaling molecules required for cell cycle progression. This is the first study to report the influence of Pulsatilla species on cancer signaling pathways. Further, our detailed phytochemical analysis of the methanolic extracts of the P. patens allowed to deduce that compounds, which strongly suppressed the growth and proliferation of HeLa cancer cells were mainly triterpenoid saponins accompanied by phenolic acids.

XPO1 inhibition synergizes with PARP1 inhibition in small cell lung cancer by targeting nuclear transport of FOXO3a

Patient mortality rates have remained stubbornly high for the past decades in small cell lung cancer (SCLC) because of having no standard targeted therapies with confirmed advantages at present. Poly [ADP-ribose] polymerase (PARP) inhibitors have shown promise in preclinical models but have had unsatisfactory clinical results in SCLC. By RNA-seq and isobaric tags for relative and absolute quantification (ITRAQ), we revealed that PARP1 inhibition led to the relocalization of forkhead box-O3a (FOXO3a) from nuclear to cytoplasm. By performing co-Immunoprecipitation (co-IP) and CRISPR-Cas9-mediated knockout plasmid we showed that FOXO3a was subject to exportin 1 (XPO1)-dependent nuclear export. We demonstrated the effects of the PARP inhibitor BMN673 on apoptosis and DNA damage were markedly enhanced by simultaneous inhibition of XPO1 in vitro. The combination of BMN673 and the XPO1 inhibitor selinexor inhibited primary SCLC cell proliferation in mini-patient-derived xenotransplants (miniPDXs) and markedly inhibited tumor growth without significant toxicity in xenograft models. The efficacy was enhanced for more than 2.5 times, compared to the single agent. Based on these findings, we further designed a novel dual PARP-XPO1 inhibitor and showed its effectiveness in SCLC. In this work, we illustrated that combining a PARP inhibitor with an XPO1 inhibitor is associated with significantly improved efficacy and tolerability. Dual PARP-XPO1 inhibition restored the FOXO3a balance and activity in SCLC. Collectively, targeting PARP1 and XPO1 opens new avenues for therapeutic intervention against SCLC, warranting further investigation in potential clinical trials.

Molecular mechanisms detected in yak lung tissue via transcriptome-wide analysis provide insights into adaptation to high altitudes

Due to their long-term colonization of and widespread distribution in plateau environments, yaks can serve as an ideal natural animal model for the adaptive evolution of other plateau species, including humans. Some studies reported that the lung and heart are two key organs that show adaptive transcriptional changes in response to high altitudes, and most of the genes that show differential expression in lung tissue across different altitudes display nonlinear regulation. To explore the molecular mechanisms that are activated in yak lung tissue in response to hypoxia, the mRNAs, lncRNAs and miRNAs of lung tissue from 9 yaks living at three different altitudes (3400 m, 4200 m and 5000 m), with three repetitions per altitude, were sequenced. Two Zaosheng cattle from 1500 m were selected as low-altitude control. A total of 21,764 mRNAs, 14,168 lncRNAs and 1209 miRNAs (305 known and 904 novel miRNAs) were identified. In a comparison of yaks and cattle, 4975 mRNAs, 3326 lncRNAs and 75 miRNAs were differentially expressed. A total of 756 mRNAs, 346 lncRNAs and 83 miRNAs were found to be differentially expressed among yaks living at three different altitudes (fold change ≥ 2 and P-value < 0.05). The differentially expressed genes between yaks and cattle were functionally enriched in long-chain fatty acid metabolic process and protein processing, while the differentially expressed genes among yaks living at three different altitudes were enriched in immune response and the cell cycle. Furthermore, competing endogenous RNA (ceRNA) networks were investigated to illustrate the roles of ceRNAs in this process, the result was also support the GO and KEGG analysis. The present research provides important genomic insights for discovering the mechanisms that are activated in response to hypoxia in yak lung tissue.

miRNA-mRNA Regulatory Network and Factors Associated with Prediction of Prognosis in Hepatocellular Carcinoma

The aim of this study was to identify novel gene and miRNA biomarkers of risk and prognostic factors for hepatocarcinogenesis using methods in systems biology. Differentially expressed genes (DEGs), microRNAs (miRNAs), and long non-coding RNA (lncRNAs) were compared between hepatocellular carcinoma (HCC) tumour tissue and normal liver tissues in the Cancer Genome Atlas (TCGA) database. Subsequently, the prognosis-associated gene co-expression network, mRNA-miRNA, and mRNA-miRNA-lncRNA regulatory networks were constructed to identify biomarkers of risk for HCC through Cox survival analysis. Seven prognosis-associated gene co-expression modules were obtained by analyzing these DEGs. An expression module including 120 genes significantly correlated with HCC patient survival. Combined with patient survival data, several mRNAs and miRNAs, including CHST4, SLC22A8, STC2, hsa-miR-326, and hsa-miR-21 were identified from the network to predict HCC patient prognosis. Clinical significance was investigated using tissue microarray analysis of samples from 258 patients with HCC. Functional annotation of hsa-miR-326 and hsa-miR-21-5p indicated specific associations with several cancer-related pathways. The present study provides a bioinformatics method for biomarker screening, which led to the identification of an integrated mRNA-miRNA-lncRNA regulatory network and their co-expression in relation to predicting HCC patient survival.

Resveratrol inhibits bile acid-induced gastric intestinal metaplasia via the PI3K/AKT/p-FoxO4 signalling pathway

Gastric intestinal metaplasia (GIM) is the essential pre-malignancy of gastric cancer. Chronic inflammation and bile acid reflux are major contributing factors. As an intestinal development transcription factor, caudal-related homeobox 2 (CDX2) is key in GIM. Resveratrol has potential chemopreventive and anti-tumour effects. The aim of the study is to probe the effect of resveratrol in bile acid-induced GIM. We demonstrated that resveratrol could reduce CDX2 expression in a time- and dose-dependent manner in gastric cell lines. A Cignal Finder 45-Pathway Reporter Array and TranSignal Protein/DNA Array Kit verified that resveratrol could increase Forkhead box O4 (FoxO4) activity and that Chenodeoxycholic acid (CDCA) could reduce FoxO4 activity. Furthermore, bioinformatics analysis showed that FoxO4 could bind to the CDX2 promoter, and these conjectures were supported by chromatin-immunoprecipitation (ChIP) assays. Resveratrol can activate FoxO4 and decrease CDX2 expression by increasing phospho-FoxO4 nucleus trans-location. Resveratrol could increase FoxO4 phosphorylation through the PI3K/AKT pathway. Ectopic FoxO4 expression can up-regulate FoxO4 phosphorylation and suppress CDCA-induced GIM marker expression. Finally, we found a reverse correlation between p-FoxO4 and CDX2 in tissue arrays. This study validates that resveratrol could reduce bile acid-induced GIM through the PI3K/AKT/p-FoxO4 signalling pathway and has a potential reversing effect on GIM, especially that caused by bile acid reflux.

Targeting oxidative stress in disease: promise and limitations of antioxidant therapy

Oxidative stress is a component of many diseases, including atherosclerosis, chronic obstructive pulmonary disease, Alzheimer disease and cancer. Although numerous small molecules evaluated as antioxidants have exhibited therapeutic potential in preclinical studies, clinical trial results have been disappointing. A greater understanding of the mechanisms through which antioxidants act and where and when they are effective may provide a rational approach that leads to greater pharmacological success. Here, we review the relationships between oxidative stress, redox signalling and disease, the mechanisms through which oxidative stress can contribute to pathology, how antioxidant defences work, what limits their effectiveness and how antioxidant defences can be increased through physiological signalling, dietary components and potential pharmaceutical intervention.

Selective inhibition of stemness through EGFR/FOXA2/SOX9 axis reduces pancreatic cancer metastasis

Pancreatic cancer (PC) is difficult to defeat due to mechanism (s) driving metastasis and drug resistance. Cancer stemness is a major challenging phenomenon associated with PC metastasis and limiting therapy efficacy. In this study, we evaluated the pre-clinical and clinical significance of eradicating pancreatic cancer stem cells (PCSC) and its components using a pan-EGFR inhibitor afatinib in combination with gemcitabine. Afatinib in combination with gemcitabine, significantly reduced Kras^G12D/+; Pdx-1 Cre (KC) (P<0.01) and Kras^G12D/+; p53^R172H/+; Pdx-1 Cre (KPC) (P<0.05) derived mouse tumoroids and KPC-derived murine syngeneic cell line growth compared to gemcitabine/afatinib alone treatment. The drug combination also reduced PC xenograft tumor burden (P<0.05) and the incidence of metastasis by affecting key stemness markers, as confirmed by co-localization studies. Moreover, the drug combination significantly decreases the growth of various PC patient-derived organoids (P<0.001). We found that SOX9 is significantly overexpressed in high-grade PC tumors (P<0.05) and in chemotherapy-treated patients compared to chemo-naïve patients (P<0.05). These results were further validated using publicly available datasets. Moreover, afatinib alone or in combination with gemcitabine decreased stemness and tumorspheres by reducing phosphorylation of EGFR family proteins, ERK, FAK, and CSC markers. Mechanistically, afatinib treatment decreased CSC markers by downregulating SOX9 via FOXA2. Indeed, EGFR and FOXA2 depletion reduced SOX9 expression in PCSCs. Taken together, pan EGFR inhibition by afatinib impedes PCSCs growth and metastasis via the EGFR/ERK/FOXA2/SOX9 axis. This novel mechanism of panEGFR inhibitor and its ability to eradicate CSC may serve as a tailor-made approach to enhance chemotherapeutic benefits in other cancer types.

The role of FOXOs and autophagy in cancer and metastasis-Implications in therapeutic development

Autophagy is a highly conserved intracellular degradation process that plays a crucial role in cell survival and stress reactions as well as in cancer development and metastasis. Autophagy process involves several steps including sequestration, fusion of autophagosomes with lysosomes and degradation. Forkhead box O (FOXO) transcription factors regulate the expression of genes involved in cellular metabolic activity and signaling pathways of cancer growth and metastasis. Recent evidence suggests that FOXO proteins are also involved in autophagy regulation. The relationship among FOXOs, autophagy, and cancer has been drawing attention of many who work in the field. This study summarizes the role of FOXO proteins and autophagy in cancer growth and metastasis and analyzes their potential roles in cancer disease management.

Sustained Exposure to Helicobacter pylori Lysate Inhibits Apoptosis and Autophagy of Gastric Epithelial Cells

Helicobacter pylori is designated as a class I carcinogen of human gastric cancer following long-term infection. During this process, H. pylori bacteria persist in proliferation and death, and release bacterial components that come into contact with gastric epithelial cells and regulate host cell function. However, the impact of long-term exposure to H. pylori lysate on the pathological changes of gastric cells is not clear. In this study, we aimed to investigate the regulation and mechanisms involved in gastric cell dysfunction following continuous exposure to H. pylori lysate. We co-cultured gastric cell lines GES-1 and MKN-45 with H. pylori lysate for 30 generations, and we found that sustained exposure to H. pylori lysate inhibited GES-1 cell invasion, migration, autophagy, and apoptosis, while it did not inhibit MKN-45 cell invasion or migration. Furthermore, Mongolian gerbils infected with H. pylori ATCC 43504 strains for 90 weeks confirmed the in vitro results. The clinical and in vitro data indicated that sustained exposure to H. pylori lysate inhibited cell apoptosis and autophagy through the Nod1-NF-κB/MAPK-ERK/FOXO4 signaling pathway. In conclusion, sustained exposure to H. pylori lysate promoted proliferation of gastric epithelial cells and inhibited autophagy and apoptosis via Nod1-NF-κB/MAPK-ERK/FOXO4 signaling pathway. In the process of H. pylori-induced gastric lesions, H. pylori lysate plays as an “accomplice” to carcinogenesis.

The role of viruses in adenocarcinoma development

Cancer is a leading public health issue that accounts for million deaths around the world every year. Human cancers contain over 100 types, which are categorized into different groups. Adenocarcinoma is one of those categories of cancer that begins from the glans and involves various tissues such as lung, esophagus, pancreas, prostate and colorectal. A range of risk factors has been identified for the development and progression of adenocarcinomas. One of these risk factors are viruses that serves special mechanisms to affect important host cell factors and tumorigenic pathways, contributing in development and promotion of adenocarcinomas. Here, we summarized the main viruses and their mechanisms implicated in the course of various adenocarcinomas development.

Optical control of ERK and AKT signaling promotes axon regeneration and functional recovery of PNS and CNS in Drosophila

Neuroregeneration is a dynamic process synergizing the functional outcomes of multiple signaling circuits. Channelrhodopsin-based optogenetics shows the feasibility of stimulating neural repair but does not pin down specific signaling cascades. Here, we utilized optogenetic systems, optoRaf and optoAKT, to delineate the contribution of the ERK and AKT signaling pathways to neuroregeneration in live Drosophila larvae. We showed that optoRaf or optoAKT activation not only enhanced axon regeneration in both regeneration-competent and -incompetent sensory neurons in the peripheral nervous system but also allowed temporal tuning and proper guidance of axon regrowth. Furthermore, optoRaf and optoAKT differ in their signaling kinetics during regeneration, showing a gated versus graded response, respectively. Importantly in the central nervous system, their activation promotes axon regrowth and functional recovery of the thermonociceptive behavior. We conclude that non-neuronal optogenetics targets damaged neurons and signaling subcircuits, providing a novel strategy in the intervention of neural damage with improved precision.

Most cells have a built-in regeneration signaling program that allows them to divide and repair. But, in the cells of the central nervous system, which are called neurons, this program is ineffective. This is why accidents and illnesses affecting the brain and spinal cord can cause permanent damage. Reactivating regeneration in neurons could help them repair, but it is not easy. Certain small molecules can switch repair signaling programs back on. Unfortunately, these molecules diffuse easily through tissues, spreading around the body and making it hard to target individual damaged cells. This both hampers research into neuronal repair and makes treatments directed at healing damage to the nervous system more likely to have side-effects. It is unclear whether reactivating regeneration signaling in individual neurons is possible.

One way to address this question is to use optogenetics. This technique uses genetic engineering to fuse proteins that are light-sensitive to proteins responsible for relaying signals in the cell. When specific wavelengths of light hit the light-sensitive proteins, the fused signaling proteins switch on, leading to the activation of any proteins they control, for example, those involved in regeneration.

Wang et al. used optogenetic tools to determine if light can help repair neurons in fruit fly larvae. First, a strong laser light was used to damage an individual neuron in a fruit fly larva that had been genetically modified so that blue light would activate the regeneration program in its neurons. Then, Wang et al. illuminated the cell with dim blue light, switching on the regeneration program. Not only did this allow the neuron to repair itself, it also allowed the light to guide its regeneration. By focusing the blue light on the damaged end of the neuron, it was possible to guide the direction of the cell's growth as it regenerated.

Regeneration programs in flies and mammals involve similar signaling proteins, but blue light does not penetrate well into mammalian tissues. This means that further research into LEDs that can be implanted may be necessary before neuronal repair experiments can be performed in mammals. In any case, the ability to focus treatment on individual neurons paves the way for future work into the regeneration of the nervous system, and the combination of light and genetics could reveal more about how repair signals work.

FOXO transcription factor family in cancer and metastasis

Forkhead box O (FOXO) transcription factors regulate diverse biological processes, affecting development, metabolism, stem cell maintenance and longevity. They have also been increasingly recognised as tumour suppressors through their ability to regulate genes essential for cell proliferation, cell death, senescence, angiogenesis, cell migration and metastasis. Mechanistically, FOXO proteins serve as key connection points to allow diverse proliferative, nutrient and stress signals to converge and integrate with distinct gene networks to control cell fate, metabolism and cancer development. In consequence, deregulation of FOXO expression and function can promote genetic disorders, metabolic diseases, deregulated ageing and cancer. Metastasis is the process by which cancer cells spread from the primary tumour often via the bloodstream or the lymphatic system and is the major cause of cancer death. The regulation and deregulation of FOXO transcription factors occur predominantly at the post-transcriptional and post-translational levels mediated by regulatory non-coding RNAs, their interactions with other protein partners and co-factors and a combination of post-translational modifications (PTMs), including phosphorylation, acetylation, methylation and ubiquitination. This review discusses the role and regulation of FOXO proteins in tumour initiation and progression, with a particular emphasis on cancer metastasis. An understanding of how signalling networks integrate with the FOXO transcription factors to modulate their developmental, metabolic and tumour-suppressive functions in normal tissues and in cancer will offer a new perspective on tumorigenesis and metastasis, and open up therapeutic opportunities for malignant diseases.

α-Mangostin-encapsulated PLGA nanoparticles inhibit colorectal cancer growth by inhibiting Notch pathway

Colorectal cancer (CRC) is the fourth leading cause of cancer‐related mortality. Recent studies have stated that Notch signalling is highly activated in cancer stem cells (CSCs) and plays an important role in the development and progression of CRC. Like normal colorectal epithelium, CRCs are organized hierarchically and include populations of CSCs. In order to enhance the biological activity of α‐mangostin, we formulated α‐mangostin‐encapsulated PLGA nanoparticles (Mang‐NPs) and examined the molecular mechanisms by which Mang‐NPs inhibit CRC cell viability, colony formation, epithelial‐mesenchymal transition (EMT) and induce apoptosis. Mang‐NPs inhibited cell viability, colony formation and induced apoptosis. Mang‐NPs also inhibited EMT by up‐regulating E‐cadherin and inhibiting N‐cadherin and transcription factors Snail, Slug and Zeb1. As dysregulated signalling through the Notch receptors promotes oncogenesis, we measured the effects of Mang‐NPs on Notch pathway. Mang‐NPs inhibited Notch signalling by suppressing the expression of Notch receptors (Notch1 and Notch2), their ligands (Jagged 1 and DLL4), γ‐secretase complex protein (Nicastrin) and downstream target (Hes‐1). Notch receptor signalling regulates cell fate determination in stem cell population. Finally, Mang‐NPs inhibited the self‐renewal capacity of CSCs, stem cell markers (CD133, CD44, Musashi and LGR5) and pluripotency maintaining factors (Oct4, Sox‐2, KLF‐4, c‐Myc and Nanog). Overall, our data suggest that Mang‐NPs can inhibit CRC growth, EMT and CSCs’ population by suppressing Notch pathway and its target. Therefore, Mang‐NPs can be used for the treatment and prevention of CRC.

Clinicopathological significance and angiogenic role of the constitutive phosphorylation of the FOXO1 transcription factor in colorectal cancer

PURPOSE

This study aimed to evaluate the clinicopathological significance of phospho-forkhead box O1 (pFOXO1) expression and its impact on the angiogenesis of colorectal cancer (CRC).

METHODS

We performed immunohistochemistry in 266 human CRC tissues for pFOXO1, and evaluated its cytoplasmic expression, regardless of its nuclear expression. We also investigated the correlation between pFOXO1 expression and clinicopathological characteristics, survival, microvessel density (MVD), and angiogenesis-related molecules in CRC.

RESULTS

pFOXO1 was expressed in the cytoplasm of 100 (37.6 %) of the 266 CRC tissues. Furthermore, pFOXO1 expression was significantly correlated with the left colon and rectum, and with vascular invasion, lymph node metastasis, distant metastasis, and higher pTNM stage. However, there was no significant correlation between pFOXO1 expression and other clinicopathological parameters. MVD was significantly higher in pFOXO1-positive tumors than in pFOXO1-negative tumors (P = 0.025). Among the angiogenesis-related molecules examined, pFOXO1 expression was significantly correlated with SIRT1 (P = 0.002) and VEGF expression (P < 0.001), but not with HIF-1α expression. pFOXO1 expression was significantly correlated with poor overall and recurrence-free survival rates (P = 0.001 and P < 0.001, respectively).

CONCLUSIONS

Taken together, our results showed that the pFOXO1 expression was significantly correlated with aggressive tumor behavior and poor survival rates. Moreover, pFOXO1 expression may affect tumor progression through SIRT1- and VEGF-induced angiogenesis.

CD83, a Novel MAPK Signaling Pathway Interactor, Determines Ovarian Cancer Cell Fate

Ovarian cancer is a leading cause of death from gynecologic malignancies worldwide. Although CD83 is widely described as a solid marker for mature dendritic cells, emerging pieces of evidence indicate the expression of membrane protein CD83 by various tumor cells, including ovarian cancer cells. However, the potential role of CD83 in ovarian cancer cell properties and development remains absolutely unknown. By using human CD83 stable overexpression and knockdown sublines of several ovarian cancer cells, we observed that CD83 advanced the growth proliferation, colony formation ability, spheroid formation, and in vivo tumorigenicity of ovarian cancer cells; surprisingly, CD83 limited their migration and invasion potentials. Positive regulation of proliferation/stemness factors (e.g., cyclin-CDKs and KIT/CD44) but negative regulation of matrix metallopeptidases (e.g., MMP1 and 7) by CD83 were revealed by the integrated analysis of transcriptome and proteome. Furthermore, immunoprecipitation-mass spectrometry (IP-MS) and co-immunoprecipitation (Co-IP) first identified the association of CD83 with MAP3K7 (also known as TAK1) and MAP3K7-binding protein TAB1 on the cell membrane. Moreover, CD83 functions through the activation of MAP3K7-MEK1/2-ERK1/2 cascades to further regulate downstream FOXO1/p21/CDK2/CCNB1 and STAT3/DKK1 signaling pathways, thus activating proliferation and spheroid formation of ovarian cancer cells, respectively. Collectively, our findings define a CD83-MAPK pathway in the regulation of proliferation and stemness in ovarian cancer cells, with potential therapeutic applications in blocking their progression.

β-Cell specific transcription factors in the context of diabetes mellitus and β-cell regeneration

All pancreatic cell populations arise from the standard gut endoderm layer in developing embryos, requiring a regulatory gene network to originate and maintain endocrine lineages and endocrine function. The pancreatic organogenesis is regulated by the temporal expression of transcription factors and plays a diverse role in the specification, development, differentiation, maturation, and functional maintenance. Altered expression and activity of these transcription factors are often associated with diabetes mellitus. Recent advancements in the stem cells and invitro derived islets to treat diabetes mellitus has attracted a great deal of interest in the understanding of factors regulating the development, differentiation, and functions of islets including transcription factors. This review discusses the myriad of transcription factors regulating the development of the pancreas, differentiation of β-islets, and how these factors regulated in normal and disease states. Exploring these factors in such critical context and exogenous or endogenous expression of development and differentiation-specific transcription factors with improved epigenetic plasticity/signaling axis in diabetic milieu would useful for the development of β-cells from other cell sources.

Role of FOXO Transcription Factors in Cancer Metabolism and Angiogenesis

Forkhead box O transcription factors (FOXOs) regulate several signaling pathways and play crucial roles in health and disease. FOXOs are key regulators of the expression of genes involved in multiple cellular processes and their deregulation has been implicated in cancer. FOXOs are generally considered tumor suppressors and evidence also suggests that they may have a role in the regulation of cancer metabolism and angiogenesis. In order to continue growing and proliferating, tumor cells have to reprogram their metabolism and induce angiogenesis. Angiogenesis refers to the process of new blood capillary formation from pre-existing vessels, which is an essential driving force in cancer progression and metastasis through supplying tumor cells with oxygen and nutrients. This review summarizes the roles of FOXOs in the regulation of cancer metabolism and angiogenesis. A deeper knowledge of the involvement of FOXOs in these two key processes involved in cancer dissemination may help to develop novel therapeutic approaches for cancer treatment.

FOXO1 and hsa-microRNA-204-5p affect the biologic behavior of MDA-MB-231 breast cancer cells

RNA molecules and targeting microRNA (miRNA) have been reported as novel focuses in recent research on breast cancer. This study aimed to probe the expression of FOXO1 in the MDA-MB-231 cell line and to explore the target effects of FOXO1 with hsa-microRNA-204-5p (miR-204) on the biologic behavior of MDA-MB-231 cells. The expression of FOXO1 mRNA and protein in MDA-MB-231 cells were derived and verified from the public databases, literature, and experimental assays, then the downregulation of FOXO1 was confirmed in the MDA-MB-231 cell line. The target binding of FOXO1 and miR-204 was predicted by miRWalk and confirmed by luciferase reporter assays. MiR-204 targeted the 3' untranslated region of FOXO1 and reduced FOXO1 expression in miR-204-transfected cells, resulting in cell growth amplification but inhibition of cell migration and apoptosis, which were assessed using the MTT method, wound healing assays, and flow cytometry, respectively. The protein levels of serine-threonine kinase (AKT), c-jun N-terminal kinase (JNK), extracellular regulatory protein kinase (ERK), and the phosphorylated protein kinases (P-AKT, P-JNK, and P-ERK) were measured by western blot. It was found that AKT, JNK, and ERK remained constant, but P-AKT, P-JNK, and P-ERK were upregulated after miR-204 transfection. In summary, the expression of FOXO1 was downregulated in MDA-MB-231 cells; and the target binding of miR-204 and FOXO1 affected phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signal pathways, leading to different alterations of cellular activity in MDA-MB-231 cells.

Angelicin-A Furocoumarin Compound With Vast Biological Potential

Angelicin, a member of the furocoumarin group, is related to psoralen which is well known for its effectiveness in phototherapy. The furocoumarins as a group have been studied since the 1950s but only recently has angelicin begun to come into its own as the subject of several biological studies. Angelicin has demonstrated anti-cancer properties against multiple cell lines, exerting effects via both the intrinsic and extrinsic apoptotic pathways, and also demonstrated an ability to inhibit tubulin polymerization to a higher degree than psoralen. Besides that, angelicin too demonstrated anti-inflammatory activity in inflammatory-related respiratory and neurodegenerative ailments via the activation of NF-κB pathway. Angelicin also showed pro-osteogenesis and pro-chondrogenic effects on osteoblasts and pre-chondrocytes respectively. The elevated expression of pro-osteogenic and chondrogenic markers and activation of TGF-β/BMP, Wnt/β-catenin pathway confirms the positive effect of angelicin bone remodeling. Angelicin also increased the expression of estrogen receptor alpha (ERα) in osteogenesis. Other bioactivities, such as anti-viral and erythroid differentiating properties of angelicin, were also reported by several researchers with the latter even displaying an even greater aptitude as compared to the commonly prescribed drug, hydroxyurea, which is currently on the market. Apart from that, recently, a new application for angelicin against periodontitis had been studied, where reduction of bone loss was indirectly caused by its anti-microbial properties. All in all, angelicin appears to be a promising compound for further studies especially on its mechanism and application in therapies for a multitude of common and debilitating ailments such as sickle cell anaemia, osteoporosis, cancer, and neurodegeneration. Future research on the drug delivery of angelicin in cancer, inflammation and erythroid differentiation models would aid in improving the bioproperties of angelicin and efficacy of delivery to the targeted site. More in-depth studies of angelicin on bone remodeling, the pro-osteogenic effect of angelicin in various bone disease models and the anti-viral implications of angelicin in periodontitis should be researched. Finally, studies on the binding of angelicin toward regulatory genes, transcription factors, and receptors can be done through experimental research supplemented with molecular docking and molecular dynamics simulation.

Novel anilino quinazoline-based EGFR tyrosine kinase inhibitors for treatment of non-small cell lung cancer

The epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of non-small cell lung cancer (NSCLC). EGFR-TKI positron emission tomography (PET) probes based on the central quinazoline core show great potential for NSCLC diagnosis, and pre-clinical and clinical therapy monitoring. In our previous research, anilino quinazoline based PET probe, N-(3-chloro-4-fluorophenyl)-7-(2-(2-(2-(2-¹⁸F-fluoroethoxy) ethoxy) ethoxy) ethoxy)-6-methoxyquinazolin-4-amine (¹⁸F-MPG), have been developed, and it has been successfully demonstrated to be a powerful non-invasive imaging tool for differentiating EGFR mutation status and stratifying NSCLC patients for EGFR-TKI treatment in a clinical study (n = 75 patients). Moreover, it has been found that ¹⁸F-MPG shows excellent tumor targeting performance and good pharmacokinetic characteristics in NSCLC patients. These results motivate us to investigate the cancer treatment efficacy of non-radioactive F-MPG and its analogue N-(3-chloro-4-fluorophenyl)-7-(2-(2-(2-(2-hydroxyethoxy)ethoxy) ethoxy) ethoxy)-6-methoxyquinazolin-4-amine (OH-MPG) in vitro and in small animal models. Our studies revealed that both F-MPG and OH-MPG displayed high therapeutic effect to NSCLC cells (IC₅₀ = 5.3 nM and 2.0 nM to HCC827 cells for F-MPG and OH-MPG, respectively). More importantly, compared with a standard EGFR-TKI, 4-(3-bromoanilino)-6,7-dimethoxyquinazoline (PD153035), F-MPG and OH-MPG showed stronger tumor inhibition in preclinical models. Furthermore, the treatment efficacy of F-MPG or OH-MPG monitored by ¹⁸F-FDG-PET indicated that tumor uptake in treated groups was significantly decreased. Ex vivo experiments showed that the levels of serum biomarkers and pathological changes in the liver were significantly reduced in the F-MPG and OH-MPG group, compared to PD153035 treated group. In conclusion, EGFR targeted F-MPG and OH-MPG exhibit promising anti-tumor activity with limited liver damage, thus representing promising drug candidates for further investigation for combating the deadly NSCLC.

Increased expression of plakoglobin is associated with upregulated MAPK and PI3K/AKT signalling pathways in early resectable pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancer types, and it is associated with a 5-year survival rate of <10% due to limited early detection methods and ineffective therapeutic options. Thus, an improved understanding of the mechanisms involved in the early stages of PDAC tumorigenesis is crucial in order to identify potential novel diagnostic and therapeutic targets. The most common signalling aberrations in PDAC occur in the Wnt/Notch signalling pathway, as well as within the epidermal growth factor receptor (EGFR) pathway and its associated ligands, EGF and transforming growth factor-β. In addition, the RAS family of oncogenes, which act downstream of EGFR, are found mutated in most pancreatic cancer samples. Plakoglobin, a component of the EGFR signalling pathway, serves an important role in normal cell adhesion; however, its role in PDAC is largely unknown. The present study used transcriptome sequencing and focussed proteome microarrays to identify dysregulated genes and proteins in PDAC. The presence of upregulated plakoglobin expression levels was identified as a distinguishing feature between the PDAC microenvironment and normal pancreatic tissue. Furthermore, plakoglobin was demonstrated to be associated with the differential upregulation of the PI3K/AKT and MAPK signalling pathways in the tumour microenvironment, which suggested that it may serve an important role in PDAC tumourigenesis.

Angiotensin II-upregulated MAP kinase phosphatase-3 modulates FOXO1 and p21 in adrenocortical H295R cells

MAPK phosphatases (MKP) downregulate the activity of mitogen-activated protein kinases (MAPK), such as ERK1/2, and modulate the processes regulated by these kinases. ERK1/2 participate in a wide range of processes including tissue-specific hormone-stimulated steroidogenesis. H295R cells are a suitable model for the study of human adrenal cortex functions, particularly steroid synthesis, and respond to angiotensin II (Ang II) triggering ERK1/2 phosphorylation in a transient fashion. MKP-3 dephosphorylates ERK1/2 and, as recently reported, forkhead box protein 1 (FOXO1). Here, we analyzed MKP-3 expression in H295R cells and its putative regulation by Ang II. Results showed the expression of MKP-3 full length (L) and a short splice variant (S), and the upregulation of both isoforms by Ang II. L and S messenger and protein levels increased 30 min after Ang II stimulation and declined over the next 3 h, a temporal frame compatible with ERK1/2 dephosphorylation. In addition, FOXO1 activation is known to include its dephosphorylation and nuclear translocation. Therefore, we analyzed the effect of Ang II on FOXO1 modulation. Ang II induced FOXO1 transient phosphorylation and translocation and also the induction of p21, a FOXO1-dependent gene, whereas MKP-3 knock-down reduced both FOXO1 translocation and p21 induction. These data suggest that, through MKP-3, Ang II counteracts its own effects on ERK1/2 activity and also triggers the activation of FOXO-1 and the induction of cell cycle inhibitor p21. Taken together, the current findings reveal the participation of MKP-3 not only in turn–off but also in turn-on signals which control important cellular processes.

Resveratrol rescues TNF‑α‑induced inhibition of osteogenesis in human periodontal ligament stem cells via the ERK1/2 pathway

Periodontitis is a common inflammatory disorder affecting the tissues surrounding the teeth, which can lead to the destruction of periodontal tissue and tooth loss. Resveratrol, a natural phytoalexin, exerts multiple biological effects. For example, its anti-inflammatory activity has been widely studied for the treatment of inflammatory bowel disease for a number of years. However, its effect on bone repair and new bone formation in an inflammatory microenvironment is not well understood. Accordingly, the effect of resveratrol on inflammation-affected human periodontal ligament stem cells (hPDLSCs) requires further investigation. In the present study, the effect of tumor necrosis factor-α (TNF-α), resveratrol, or the combination of both on the osteogenic differentiation of hPDLSCs, as well as the underlying mechanisms involved, were investigated. Cell Counting Kit-8 assay, alkaline phosphatase staining, Alizarin red staining, Oil Red O staining, reverse transcription-quantitative PCR and western blotting were used in the present study. It was demonstrated that resveratrol enhanced hPDLSC osteogenesis and reversed the inhibitory effects of TNF-α on this process. Further mechanistic studies indicated that resveratrol exerted anti-inflammatory activity by activating the ERK1/2 pathway, decreasing the secretion of interleukin (IL)-6 and IL-8 induced by TNF-α, and enhancing hPDLSCs osteogenesis. The present study suggested that resveratrol may be a novel and promising therapeutic choice for periodontitis.

Hyaluronan-binding protein 1 (HABP1) overexpression triggers induction of senescence in fibroblasts cells

Hyaluronan-binding protein 1 (HABP1), a multi-compartmental, multi-functional protein has a wide range of functions, which can be attributed to its ability to associate with a variety of cellular ligands. Earlier we have reported that HABP1 overexpression in rat normal fibroblasts (F-HABP07) shows chronic generation of reactive oxygen species (ROS), induction of autophagy, and apoptosis. However, a significant proportion of cells remained viable after the majority went through apoptosis from 60 to 72 h. In this study, an attempt has been made to delineate the cellular events in the declined population of surviving cells. It has been elucidated here that, these cells at later time points of growth, that is, 72 and 84 h, not only appeared to shrink but also are devoid of autophagic vacuoles and displayed polyploidy. F-HABP07 cells exhibited an altered cytoskeletal structure from their parental cell line F111, assumed to be caused upon inhibition of actin polymerization and decrease in IQ motif-containing GTPase activating protein 1 (IQGAP1), a key protein associated with maintenance of cytoskeletal integrity. Enhanced expression and nuclear localization of AKT observed in F-HABP07 cells appears to be contributing toward the maintenance of high ROS levels in these cells and also potentially modulating the IQGAP1 activity. These observations, in fact have been considered to result in sustained DNA damage, which then leads to increased expression of p53 and activation of p21 and carry out the cellular events responsible for senescence. Subsequent assessment of the presence of positive β-gal staining and enhanced expression of p16^INK4a in F-HABP07, confirmed that HABP1 overexpressing fibroblasts undergo senescence.

FOXO4 expression associates with glioblastoma development and FOXO4 expression inhibits cell malignant phenotypes in vitro and in vivo

BACKGROUND AND AIM

Forkhead box protein O4 (FOXO4) is a transcription factor, and aberrant FOXO4 expression is associated with development of various human cancers. This study explored the role of FOXO4 in glioma in vitro and in vivo.

METHODS

FOXO4 expression was first assessed in normal brain tissues, low-grade glioma, glioblastoma multiforme (GBM), normal human astrocytes (HA), and GBM cell lines, while manipulation of FOXO4 expression in glioma cell lines was assessed using qRT-PCR, Western blot, and cell viability CCK-8, Transwell, and a nude mouse subcutaneous xenograft assays.

KEY FINDINGS

The data showed downregulated FOXO4 expression in GBM tissues and cell lines. FOXO4 overexpression induced by transfection with FOXO4 cDNA significantly inhibited GBM cell proliferation, migration, and invasion, but increased tumor cells to undergo apoptosis in vitro, while suppressed growth of GBM cell subcutaneous xenografts in nude mice. In conclusion, FOXO4 possesses an anti-cancer glioma activity, which could be a novel target for future control of GBM.

Current perspective on the regulation of FOXO4 and its role in disease progression

Forkhead box O4 (FOXO4) is a member of the FOXO family that regulates a number of genes involved in metabolism, cell cycle, apoptosis, and cellular homeostasis via transcriptional activity. It also mediates cell responses to oxidative stress and treatment with antitumor agents. The expression of FOXO4 is repressed by microRNAs in multiple cancer cells, while FOXO4 function is regulated by post-translational modifications and interaction with other proteins. The deregulation of FOXO4 is closely linked to the progression of several types of cancer, senescence, and other diseases. In this review, we present recent findings on the regulation of FOXO4 in physiological and pathological conditions and provide an overview of the complex role of FOXO4 in disease development and response to therapy.

Molecular Mechanism of Pancreatic Stellate Cells Activation in Chronic Pancreatitis and Pancreatic Cancer

Activated pancreatic stellate cells (PSCs) are the main effector cells in the process of fibrosis, a major pathological feature in pancreatic diseases that including chronic pancreatitis and pancreatic cancer. During tumorigenesis, quiescent PSCs change into an active myofibroblast-like phenotype which could create a favorable tumor microenvironment and facilitate cancer progression by increasing proliferation, invasiveness and inducing treatment resistance of pancreatic cancer cells. Many cellular signals are revealed contributing to the activation of PSCs, such as transforming growth factor-β, platelet derived growth factor, mitogen-activated protein kinase (MAPK), Smads, nuclear factor-κB (NF-κB) pathways and so on. Therefore, investigating the role of these factors and signaling pathways in PSCs activation will promote the development of PSCs-specific therapeutic strategies that may provide novel options for pancreatic cancer therapy. In this review, we systematically summarize the current knowledge about PSCs activation-associated stimulating factors and signaling pathways and hope to provide new strategies for the treatment of pancreatic diseases.

Role of TNFα and leptin signaling in colon cancer incidence and tumor growth under obese phenotype

Epidemiological studies over the last few decades have shown a strong influence of obesity on colon cancer risk and its progression. These studies have primarily focussed on the role of adipokines in driving cancer progression. We investigated the incidence of cancerous polyp formation and tumor progression in presence and absence of functional leptin along with exploring the role of tumor necrosis factor α (TNFα), under obese condition. By utilizing diet induced obese and genetically obese mice, carcinogen induced colon polyp formation was investigated. Experiments were performed using tumor tissues and cell lines to delineate the inter-relationship between leptin and TNFα. Data shown in this report indicates that in leptin knockdown obese mice, AOM/DSS induced polyps are smaller and lesser in numbers as compared to AOM/DSS induced polyps in diet induced obese mice. Further in vitro experiments suggest that abrogation of leptin associated pathways promote TNFα induced apoptosis. Mechanistically, we report that TNFα induces p53 independent cell death through up regulation of p53 upregulated modulator of apoptosis (PUMA). TNFα induced PUMA was inhibited upon pre- exposure of cells to leptin, prior to TNFα treatment. Collectively these results indicate that obesity due to leptin non-functionality facilitates TNFα induced colon cancer cell death.

MicroRNAs in Pancreatic Cancer: biomarkers, prognostic, and therapeutic modulators

A severe lack of early diagnosis coupled with resistance to most available therapeutic options renders pancreatic cancer as a major clinical concern. The limited efficacy of current treatments necessitates the development of novel therapeutic strategies that are based on an understanding of the molecular mechanisms involved in pancreatic cancer progression. MicroRNAs (miRNAs) are non-coding small RNAs that regulate the expression of multiple proteins in the post-translation process and thus have promise as biomarkers, prognostic agents, and as advanced pancreatic therapies. Profiling of deregulated miRNAs in pancreatic cancer can correlate to diagnosis, indicate optimal treatment and predict response to therapy. Furthermore, understanding the main effector genes in pancreatic cancer along with downstream pathways can identify possible miRNAs as therapeutic candidates. Additionally, obstacles to the translation of miRNAs into the clinic are also considered. Distinct miRNA expression profiles can correlate to stages of malignant pancreatic disease, and hold potential as biomarkers, prognostic markers and clinical targets. However, a limited understanding and validation of the specific role of such miRNAs stunts clinical application. Target prediction using algorithms provides a wide range of possible targets, but these miRNAs still require validation through pre-clinical studies to determine the knock-on genetic effects.

Organic anion transporters and PI3K-AKT-mTOR pathway mediate the synergistic anticancer effect of pemetrexed and rhein

The aim of this study was to explore whether rhein could enhance the effects of pemetrexed (PTX) on the therapy of non-small-cell lung cancer (NSCLC) and to clarify the associated molecular mechanism. Our study shows that rhein in combination with PTX could obviously increase the systemic exposure of PTX in rats, which would be mediated by the inhibition of organic anion transporters (OATs). Furthermore, the toxicity of PTX was significantly raised by rhein in A549 cells in a concentration-dependent manner. Concomitant administration of rhein and PTX-induced cell apoptosis compared with PTX alone in flow cytometry assays, which was further validated by the protein expressions of the apoptotic markers B-cell lymphoma-2/Bcl-2-associated x (Bcl-2/Bax) and Cleaved-Caspase3 (Cl-Caspase3). Meanwhile, the results of monodansylcadaverine (MDC) dyeing experiments showed that PTX-induced autophagy could be enhanced by combination therapy with rhein in A549 cells. Western blot analysis indicated that the synergistic effect of rhein on PTX-mediated autophagy may be interrelated to PI3K-AKT-mTOR pathway inhibition and to the enhancement of p-AMPK and light chain 3-II (LC3-II) protein levels. From these findings, it could be surmised that rhein enhanced the antitumor activity of PTX through influencing autophagy and apoptosis by modulating the PI3K-AKT-mTOR pathway and Bcl-2 family of proteins in A549 cells. Our findings demonstrated that the potential application of rhein as a candidate drug in combination with PTX is promising for treatment of the human lung cancer.

Antipsychotic Drug Trifluoperazine Suppresses Colorectal Cancer by Inducing G0/G1 Arrest and Apoptosis

Repurposing existing drugs for cancer treatment is an effective strategy. An approved antipsychotic drug, trifluoperazine (TFP), has been reported to have potential anticancer effects against several cancer types. Here, we investigated the effect and molecular mechanism of TFP in colorectal cancer (CRC). In vitro studies showed that TFP induced G0/G1 cell cycle arrest to dramatically inhibit CRC cell proliferation through downregulating cyclin-dependent kinase (CDK) 2, CDK4, cyclin D1, and cyclin E and upregulating p27. TFP also induced apoptosis, decreased mitochondrial membrane potential, and increased reactive oxygen species levels in CRC cells, indicating that TFP induced mitochondria-mediated intrinsic apoptosis. Importantly, TFP significantly suppressed tumor growth in two CRC subcutaneous tumor models without side effects. Interestingly, TFP treatment increased the expression levels of programmed death-1 ligand 1 (PD-L1) in CRC cells and programmed death-1 (PD-1) in tumor-infiltrating CD4+ and CD8+ T cells, implying that the combination of TFP with an immune checkpoint inhibitor, such as an anti-PD-L1 or anti-PD-1 antibody, might have synergistic anticancer effects. Taken together, our study signifies that TFP is a novel treatment strategy for CRC and indicates the potential for using the combination treatment of TFP and immune checkpoint blockade to increase antitumor efficiency.

Combining next-generation sequencing and single-molecule sequencing to explore brown plant hopper responses to contrasting genotypes of japonica rice

BACKGROUND

The brown plant hopper (BPH), Nilaparvata lugens, is one of the major pest of rice (Oryza sativa). Plant defenses against insect herbivores have been extensively studied, but our understanding of insect responses to host plants' resistance mechanisms is still limited. The purpose of this study is to characterize transcripts of BPH and reveal the responses of BPH insects to resistant rice at transcription level by using the advanced molecular techniques, the next-generation sequencing (NGS) and the single-molecule, real-time (SMRT) sequencing.

RESULTS

The current study obtained 24,891 collapsed isoforms of full-length transcripts, and 20,662 were mapped to known annotated genes, including 17,175 novel transcripts. The current study also identified 915 fusion genes, 1794 novel genes, 2435 long non-coding RNAs (lncRNAs), and 20,356 alternative splicing events. Moreover, analysis of differentially expressed genes (DEGs) revealed that genes involved in metabolic and cell proliferation processes were significantly enriched in up-regulated and down-regulated sets, respectively, in BPH fed on resistant rice relative to BPH fed on susceptible wild type rice. Furthermore, the FoxO signaling pathway was involved and genes related to BPH starvation response (Nlbmm), apoptosis and autophagy (caspase 8, ATG13, BNIP3 and IAP), active oxygen elimination (catalase, MSR, ferritin) and detoxification (GST, CarE) were up-regulated in BPH responses to resistant rice.

CONCLUSIONS

The current study provides the first demonstrations of the full diversity and complexity of the BPH transcriptome, and indicates that BPH responses to rice resistance, might be related to starvation stress responses, nutrient transformation, oxidative decomposition, and detoxification. The current result findings will facilitate further exploration of molecular mechanisms of interaction between BPH insects and host rice.

Dracorhodin perchlorate protects pancreatic β-cells against glucotoxicity- or lipotoxicity-induced dysfunction and apoptosis in vitro and in vivo

Glucotoxicity or lipotoxicity leads to hyperglycemia and insulin secretion deficiency, which are important causes for the onset of type 2 diabetes mellitus (T2DM). Thus, the restoration of β-cell function is a long-sought goal in diabetes research. Previous studies have implicated pancreatic and duodenal homeobox 1 gene (Pdx1) in β-cell function and insulin secretion. In this study, we established a Pdx1 promoter-dependent luciferase system and identified the natural compound dracorhodin perchlorate (DP) as an effective promotor of Pdx1 expression. We further demonstrated that DP could significantly inhibit β-cell apoptosis induced by 33 mm glucose or 200 μm palmitate by interfering with endoplasmic reticulum stress and mitochondrial pathways and enhance insulin secretion as well. These effects were associated with enhanced activities of Erk1/2, which in turn promoted Pdx1 expression and increased the ratio of Bcl2/Bax, since inhibition of the Erk1/2 pathway abolished the DP-induced expression of Pdx1 and suppression of apoptosis. In addition, our in vivo results in diabetic mice indicated that DP treatment lowered blood glucose, raised insulin levels, enhanced Pdx1 expression and increased islet size and number in the pancreas of diabetic mice. Our findings suggest that Pdx1 is a potential target molecule of DP in the treatment of T2DM via the inhibition of glucotoxicity- or lipotoxicity- induced β-cell apoptosis and the attenuation of insulin secretion dysfunction.

MPK-1/ERK pathway regulates DNA damage response during development through DAF-16/FOXO

Ultraviolet (UV) induces distorting lesions to the DNA that can lead to stalling of the RNA polymerase II (RNAP II) and that are removed by transcription-coupled nucleotide excision repair (TC-NER). In humans, mutations in the TC-NER genes CSA and CSB lead to severe postnatal developmental defects in Cockayne syndrome patients. In Caenorhabditis elegans, mutations in the TC-NER genes csa-1 and csb-1, lead to developmental growth arrest upon UV treatment. We conducted a genetic suppressor screen in the nematode to identify mutations that could suppress the developmental defects in csb-1 mutants. We found that mutations in the ERK1/2 MAP kinase mpk-1 alleviate the developmental retardation in TC-NER mutants, while constitutive activation of the RAS-MAPK pathway exacerbates the DNA damage-induced growth arrest. We show that MPK-1 act via insulin/insulin-like signaling pathway and regulates the FOXO transcription factor DAF-16 to mediate the developmental DNA damage response.

Molecular identification and diapause-related functional characterization of a novel dual-specificity kinase gene, MPKL, in Locusta migratoria

Diapause is an important overwintering strategy enabling Locusta migratoria to survive under stressed conditions. We identified a novel dual-specificity kinase gene that is differentially expressed between long and short day-treated L. migratoria. To determine its function on photoperiodic diapause induction, we cloned the specific gene. Interestingly, phylogenetic analysis shows that this dual-specificity kinase is of the mycetozoa protein kinase-like (MPKL) type and may have been transferred horizontally from Mycetozoa to L. migratoria. RNA interference results confirm that MPKL promotes photoperiodic diapause induction of L. migratoria. Furthermore, MPKL significantly inhibits Akt and FOXO (i.e. forkhead box protein O) phosphorylation levels in ovaries, and also enhances reactive oxygen species, superoxide dismutase and catalase activities, whereas peroxidase activity is decreased under both photoperiodic regimes. The findings of the present study offer insight into the molecular mechanism responsible for dual-specificity kinase-induced diapause in insects.

Reduced Expression of Sprouty1 Contributes to the Aberrant Proliferation and Impaired Apoptosis of Acute Myeloid Leukemia Cells

In most of the acute myeloid leukemia patients there is an aberrant tyrosine kinase activity. The prototype of Sprouty proteins was originally identified in Drosophila melanogaster as antagonists of Breathless, the mammalian ortholog of fibroblast growth factor receptor. Usually, SPRY family members are inhibitors of RAS signaling induced by tyrosine kinases receptors and they are implicated in negative feedback processes regulating several intracellular pathways. The present study aims to investigate the role of a member of the Sprouty family, Sprouty1, as a regulator of cell proliferation and growth in patients affected by acute myeloid leukemia. Sprouty1 mRNA and protein were both significantly down-regulated in acute myeloid leukemia cells compared to the normal counterpart, but they were restored when remission is achieved after chemotherapy. Ectopic expression of Sprouty1 revealed that it plays a key role in the proliferation and apoptotic defect that represent a landmark of the leukemic cells. Our study identified Sprouty1 as negative regulator involved in the aberrant signals of adult acute myeloid leukemia. Furthermore, we found a correlation between Sprouty1 and FoxO3a delocalization in acute myeloid leukemia (AML) patients at diagnosis, suggesting a multistep regulation of RAS signaling in human cancers.

Cellular Effects of Butyrate on Vascular Smooth Muscle Cells are Mediated through Disparate Actions on Dual Targets, Histone Deacetylase (HDAC) Activity and PI3K/Akt Signaling Network

Vascular remodeling is a characteristic feature of cardiovascular diseases. Altered cellular processes of vascular smooth muscle cells (VSMCs) is a crucial component in vascular remodeling. Histone deacetylase inhibitor (HDACI), butyrate, arrests VSMC proliferation and promotes cell growth. The objective of the study is to determine the mechanism of butyrate-induced VSMC growth. Using proliferating VSMCs exposed to 5 mM butyrate, immunoblotting studies are performed to determine whether PI3K/Akt pathway that regulates different cellular effects is a target of butyrate-induced VSMC growth. Butyrate inhibits phosphorylation-dependent activation of PI3K, PDK1, and Akt, eliciting differential effects on downstream targets of Akt. Along with previously reported Ser9 phosphorylation-mediated GSK3 inactivation leading to stability, increased expression and accumulation of cyclin D1, and epigenetic histone modifications, inactivation of Akt by butyrate results in: transcriptional activation of FOXO1 and FOXO3 promoting G1 arrest through p21Cip1/Waf1 and p15INK4B upregulation; inactivation of mTOR inhibiting activation of its targets p70S6K and 4E-BP1 impeding protein synthesis; inhibition of caspase 3 cleavage and downregulation of PARP preventing apoptosis. Our findings imply butyrate abrogates Akt activation, causing differential effects on Akt targets promoting convergence of cross-talk between their complimentary actions leading to VSMC growth by arresting proliferation and inhibiting apoptosis through its effect on dual targets, HDAC activity and PI3K/Akt pathway network.

Dissecting mechanisms of resistance to targeted drug combination therapy in human colorectal cancer

Genomic alterations in cancer cells result in vulnerabilities that clinicians can exploit using molecularly targeted drugs, guided by knowledge of the tumour genotype. However, the selective activity of these drugs exerts an evolutionary pressure on cancers that can result in the outgrowth of resistant clones. Use of rational drug combinations can overcome resistance to targeted drugs, but resistance may eventually develop to combinatorial therapies. We selected MAPK- and PI3K-pathway inhibition in colorectal cancer as a model system to dissect out mechanisms of resistance. We focused on these signalling pathways because they are frequently activated in colorectal tumours, have well-characterised mutations and are clinically relevant. By treating a panel of 47 human colorectal cancer cell lines with a combination of MEK- and PI3K-inhibitors, we observe a synergistic inhibition of growth in almost all cell lines. Cells with KRAS mutations are less sensitive to PI3K inhibition, but are particularly sensitive to the combined treatment. Colorectal cancer cell lines with inherent or acquired resistance to monotherapy do not show a synergistic response to the combination treatment. Cells that acquire resistance to an MEK-PI3K inhibitor combination treatment still respond to an ERK-PI3K inhibitor regimen, but subsequently also acquire resistance to this combination treatment. Importantly, the mechanisms of resistance to MEK and PI3K inhibitors observed, MEK1/2 mutation or loss of PTEN, are similar to those detected in the clinic. ERK inhibitors may have clinical utility in overcoming resistance to MEK inhibitor regimes; however, we find a recurrent active site mutation of ERK2 that drives resistance to ERK inhibitors in mono- or combined regimens, suggesting that resistance will remain a hurdle. Importantly, we find that the addition of low concentrations of the BCL2-family inhibitor navitoclax to the MEK-PI3K inhibitor regimen improves the synergistic interaction and blocks the acquisition of resistance.

Upregulation of SPAG6 in Myelodysplastic Syndrome: Knockdown Inhibits Cell Proliferation via AKT/FOXO Signaling Pathway

Recently, sperm-associated antigen 6 (SPAG6), a member of the cancer-testis antigen family, has been shown to be involved in tumorigenesis. An increasing number of studies have shown that SPAG6 expression is associated with the pathogenesis of myelodysplastic syndrome (MDS). However, the mechanism has not been clearly elucidated. Our previous results indicated that SPAG6 affected cell apoptosis in MDS. In this study, we used reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to demonstrate that the mRNA expression of SPAG6 in bone marrow cells of patients with MDS or MDS-derived acute myeloid leukemia (MDS-AML) was higher than that of cancer-free patients. Kaplan-Meier survival curve analysis of published AML found that patients with high expression of SPAG6 had poor survival. The results of the cell counting kit-8, FACS, RT-qPCR, and Western blotting assays indicated that SPAG6 knockdown in the SKM-1 cell line inhibited cell proliferation, and affected cell cycle and differentiation. Furthermore, we found that SPAG6 knockdown affected the proliferation of SKM-1 cells by mediating the G1-to-S transition of the cell cycle. Moreover, we demonstrated that the antiproliferative effect of SPAG6 knockdown was associated with the upregulation of the cyclin-dependent kinase inhibitor p27Kip1, and regulation of the AKT/FOXO pathway. These findings indicated that SPAG6 might be a potential therapeutic target.

Dual inhibition of Akt and ERK signaling induces cell senescence in triple-negative breast cancer

Activated Akt and ERK signaling pathways are closely related to breast cancer progression, and Akt or ERK inhibition induces cell senescence. However, the crosstalk between the Akt and ERK signaling pathways in cell senescence and how to simultaneously suppress Akt and ERK signaling in triple-negative breast cancer (TNBC) are undefined. In this study, we found that norcantharidin (NCTD) effectively induced cell senescence and cell cycle arrest in TNBC in vitro, which was accompanied by a decline in phosphorylated Akt and ERK1/2 and a rise in p21 and p16. The inhibitors LY294002 and U0126 imitated the effect of NCTD when these two inhibitors were combined regardless of crosstalk between these two signaling pathways. In addition, NCTD inhibited the growth of xenografts via downregulation of phosphorylated Akt and ERK1/2 and upregulation of p21 in vivo. However, NCTD upregulated the level of soluble signaling factors of the senescence-associated secretory phenotype (SASP) in a NF-κB-independent manner. Collectively, these findings demonstrate that NCTD induced cell senescence and cell cycle arrest mainly by simultaneously blocking Akt and ERK signaling in TNBC, suggesting that NCTD may be used as a potential adjuvant therapy in TNBC.

Induction of apoptosis in ovarian cancer cells by miR-493-3p directly targeting AKT2, STK38L, HMGA2, ETS1 and E2F5

Apoptosis is a form of directed programmed cell death with a tightly regulated signalling cascade for the destruction of single cells. MicroRNAs (miRNAs) play an important role as fine tuners in the regulation of apoptotic processes. MiR-493-3p mimic transfection leads to the induction of apoptosis causing the breakdown of mitochondrial membrane potential and the activation of Caspases resulting in the fragmentation of DNA in several ovarian carcinoma cell lines. Ovarian cancer shows with its pronounced heterogeneity a very high death-to-incidence ratio. A target gene analysis for miR-493-3p was performed for the investigation of underlying molecular mechanisms involved in apoptosis signalling pathways. Elevated miR-493-3p levels downregulated the mRNA and protein expression levels of Serine/Threonine Kinase 38 Like (STK38L), High Mobility Group AT-Hook 2 (HMGA2) and AKT Serine/Threonine Kinase 2 (AKT2) by direct binding as demonstrated by luciferase reporter assays. Notably, the protein expression of RAF1 Proto-Oncogene, Serine/Threonine Kinase (RAF1) was almost completely downregulated by miR-493-3p. This interaction, however, was indirect and regulated by STK38L phosphorylation. In addition, RAF1 transcription was diminished as a result of reduced transcription of ETS proto-oncogene 1 (ETS1), another direct target of miR-493-3p. Taken together, our observations have uncovered the apoptosis inducing potential of miR-493-3p through its regulation of multiple target genes participating in the extrinsic and intrinsic apoptosis pathway.

Role of FoxO Proteins in Cellular Response to Antitumor Agents

FoxO proteins (FoxOs) are transcription factors with a common DNA binding domain that confers selectivity for DNA interaction. In human cells, four proteins (FoxO1, FoxO3, FoxO4 and FoxO6), with redundant activity, exhibit mainly a positive effect on genes involved in cell cycle, apoptosis regulation and drug resistance. Thus, FoxOs can affect cell response to antitumor agent treatment. Their transcriptional activity depends on post-translational modifications, including phosphorylation, acetylation, and mono/poly-ubiquitination. Additionally, alterations in microRNA network impact on FoxO transcripts and in turn on FoxO levels. Reduced expression of FoxO1 has been associated with resistance to conventional agents (e.g., cisplatin) and with reduced efficacy of drug combinations in ovarian carcinoma cells. FoxO3 has been shown as a mediator of cisplatin toxicity in colorectal cancer. A requirement for FoxO3-induced apoptosis has been reported in cells exposed to targeted agents (e.g., gefitinib). Recently, the possibility to interfere with FoxO1 localization has been proposed as a valuable approach to improve cell sensitivity to cisplatin, because nuclear retention of FoxO1 may favor the induction of pro-apoptotic genes. This review focuses on the role of FoxOs in drug treatment response in tumor cells and discusses the impact of the expression of these transcription factors on drug resistance/sensitivity.

Vitronectin, fibronectin and epidermal growth factor induce proliferation via the JNK and ERK pathways in insulinoma INS-1 cells

An insulinoma is a tumor formed by beta cells in the Langerhans islets of the pancreas. Vitronectin (VTN), fibronectin (FN) and epidermal growth factor (EGF) are important in cell signaling. The aim of this study was to investigate the molecular mechanism that occurs in INS-1 cells with the administration of VTN, FN and EGF in proliferative doses. We determined the proliferative doses of EGF, VTN and FN. The molecular mechanism of proliferation has been investigated alone or in the combination of these proteins. It was observed that INS-1 cells did not have VTN and FN. Cell viability increased with the administration of 0.1 μg/ml VTN, 0.1 μg/ml FN and 1 mg/ml EGF. Proliferation increased with the administration of FN + EGF, and VTN + FN + EGF together when compared to the control group. The total JNK levels did not change between the groups; however, the active JNK levels increased in the VT + FN + EGF group compared to the control group. The total ERK levels increased in the VT + FN + EGF group, and the active ERK levels increased in the VTN + FN, VTN + EGF and VTN + FN + EGF groups compared to the control group. The JNK and ERK pathways are important for proliferation. The JNK and ERK pathways were activated in VTN + FN + EGF administered group. However, it was observed that the ERK pathway was more active than the JNK pathway.

Crosstalk between Phosphoinositide 3-kinase/Akt signaling pathway with DNA damage response and oxidative stress in cancer

The phosphatidylinositol 3-kinases (PI3K)/Akt signaling pathway is one of the well-characterized and most important signaling pathways activated in response to DNA damage. This review discusses the most recent discoveries on the involvement of PI3K/Akt signaling pathway in cancer development, as well as stimulation of some important signaling networks involved in the maintenance of cellular homeostasis upon DNA damage, with an exploration of how PI3K/Akt signaling pathway contributes to the regulation of modulators and effectors underlying DNA damage response, the intricate, protein-based signal transduction network, which decides between cell cycle arrest, DNA repair, and apoptosis, the elimination of irreparably damaged cells to maintain homeostasis. The review continues by looking at the interplay between cell cycle checkpoints, checking the repair of damage inflicted to the DNA before entering DNA replication to facilitate DNA synthesis, and PI3K/Akt signaling pathway. We then investigate the challenges the cells overcome to ameliorate damages induced by oxidative activities, for example, the recruitment of many pathways and factors to maintain integrity and hemostasis. Finally, the review provides a discussion of how cells use the PI3K/Akt signaling pathway to regulate the balance between these networks.

Importance of gene expression signatures in pancreatic cancer prognosis and the establishment of a prediction model

Background and aim

Pancreatic cancer (PC) is one of the most common tumors with a poor prognosis. The current American Joint Committee on Cancer (AJCC) staging system, based on the anatomical features of tumors, is insufficient to predict PC outcomes. The current study is endeavored to identify important prognosis-related genes and build an effective predictive model.

Methods

Multiple public datasets were used to identify differentially expressed genes (DEGs) and survival-related genes (SRGs). Bioinformatics analysis of DEGs was used to identify the main biological processes and pathways involved in PC. A risk score based on SRGs was computed through a univariate Cox regression analysis. The performance of the risk score in predicting PC prognosis was evaluated with survival analysis, Harrell's concordance index (C-index), area under the curve (AUC), and calibration plots. A predictive nomogram was built through integrating the risk score with clinicopathological information.

Results

A total of 945 DEGs were identified in five Gene Expression Omnibus datasets, and four SRGs (LYRM1, KNTC1, IGF2BP2, and CDC6) were significantly associated with PC progression and prognosis in four datasets. The risk score showed relatively good performance in predicting prognosis in multiple datasets. The predictive nomogram had greater C-index and AUC values, compared with those of the AJCC stage and risk score.

Conclusion

This study identified four new biomarkers that are significantly associated with the carcinogenesis, progression, and prognosis of PC, which may be helpful in studying the underlying mechanism of PC carcinogenesis. The predictive nomogram showed robust performance in predicting PC prognosis. Therefore, the current model may provide an effective and reliable guide for prognosis assessment and treatment decision-making in the clinic.