Upregulation Of P53 Expression Research Articles

Circular RNA_0074027 participates in cell proliferation, apoptosis and metastasis of colorectal cancer cells through regulation of miR‑525‑3p.

The present study aimed to elucidate the biological function of circular RNAs (circRNA) 0074027 in colorectal cancer (CRC). The expression of circRNA-0074027 in CRC tissues and cells was determined by reverse transcription-quantitative PCR. The in vitro experiments, including Cell Counting Kit-8 (CCK-8) assay, 5-Ethynyl-2′-deoxyuridine assay, flow cytometry and Transwell assay, were applied to evaluate cell proliferation, apoptosis and metastasis ability respectively following downregulation of circRNA-0074027. The correlation between circRNA-0074027 and micro (mi)RNA-525-3p was determined via dual-luciferase reporter assay. Finally, western blotting was used to explore the possible regulatory mechanism. CircRNA-0074027 was upregulated in CRC tissues, while miR-525-3p expression was reduced. In addition, patients with CRC and circRNA-0074027 overexpression were more likely to have low tumor differentiation, lymph node metastasis and advanced TMN stage. Deletion of circRNA-0074027 could suppress cell proliferation and metastasis through upregulating p53 expression and forbidding epithelial-mesenchymal transition signaling pathway. The addition of miRNA-525-3p inhibitors could reverse the anti-tumor effects induced by the deletion of circRNA-0074027. The downregulation of cirRNA_0074027 inhibited tumor progression via sponging miR-525-3p, which could be a promising treatment bio-marker for CRC.

Nuclear PTEN and p53 suppress stress-induced liver cancer through distinct mechanisms

PTEN and p53 are highly mutated in many cancers. These two tumor suppressors have critical functions in the nucleus, such as DNA repair, cell cycle progression, and genome maintenance. However, the in vivo functional relationship of nuclear PTEN and p53 is unknown. Here, we analyzed the liver of mice in which nuclear PTEN and p53 are individually or simultaneously depleted. We found that nuclear PTEN loss greatly upregulates p53 expression upon oxidative stress, while the loss of p53 potentiates stress-induced accumulation of PTEN in the nucleus. Next, we examined oxidative stress-induced DNA damage in hepatocytes, and found that nuclear PTEN loss aggravated the damage while p53 loss did not. Notably, mice lacking nuclear PTEN had increased hepatocellular carcinoma under oxidative stress, while mice lacking p53 in hepatocytes had accelerated hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The formation of cholangiocarcinoma appears to involve the transformation of hepatocytes into cholangiocarcinoma. Simultaneous loss of nuclear PTEN and p53 exacerbated both types of liver cancers. These data suggest that nuclear PTEN and p53 suppress liver cancers through distinct mechanisms.

Differential Response of Lung Cancer Cells, with Various Driver Mutations, to Plant Polyphenol Resveratrol and Vitamin D Active Metabolite PRI-2191.

Plant polyphenols and vitamins D exhibit chemopreventive and therapeutic anticancer effects. We first evaluated the biological effects of the plant polyphenol resveratrol (RESV) and vitamin D active metabolite PRI-2191 on lung cancer cells having different genetic backgrounds. RESV and PRI-2191 showed divergent responses depending on the genetic profile of cells. Antiproliferative activity of PRI-2191 was noticeable in EGFRmut cells, while RESV showed the highest antiproliferative and caspase-3-inducing activity in KRASmut cells. RESV upregulated p53 expression in wtp53 cells, while downregulated it in mutp53 cells with simultaneous upregulation of p21 expression in both cases. The effect of PRI-2191 on the induction of CYP24A1 expression was enhanced by RESV in two KRASmut cell lines. The effect of RESV combined with PRI-2191 on cytokine production was pronounced and modulated. RESV cooperated with PRI-2191 in regulating the expression of IL-8 in EGFRmut cells, while OPN in KRASmut cells and PD-L1 in both cell subtypes. We hypothesize that the differences in response to RESV and PRI-2191 between EGFRmut and KRASmut cell lines result from the differences in epigenetic modifications since both cell subtypes are associated with the divergent smoking history that can induce epigenetic alterations.

RETRACTED: MicroRNA-199a-5p accelerates nucleus pulposus cell apoptosis and IVDD by inhibiting SIRT1-mediated deacetylation of p21

Intervertebral disc degeneration (IVDD) is a multifactorial pathological process associated with low back pain in which nucleus pulposus cell senescence is disrupted. Increasing evidence reveals that IVDD can be modulated by microRNAs (miRNAs or miRs). In the current study, we set out to elucidate the role of miR-199a-5p in nucleus pulposus cell apoptosis and IVDD progression. After sample collection, we found highly expressed miR-199a-5p in nucleus pulposus tissues of both patients diagnosed with IVDD and in IVDD rat models. Next, normal and degenerated nucleus pulposus cells were isolated and transfected with miR-199a-5p mimic, miR-199a-5p inhibitor, overexpressed sirtuin 1 (oe-SIRT1), and oe-p21, followed by detection of nucleus pulposus cell apoptosis and proliferation. In addition, the binding of miR-199a-5p and SIRT1, the interaction between p21 and SIRT1, and the regulation of p21 acetylation by SIRT1 were analyzed. We found that miR-199a-5p overexpression promoted nucleus pulposus cell apoptosis and IVDD. Overexpression of SIRT1 countered the effect of miR-199a-5p overexpression, while overexpression of p21 reversed the effect of miR-199a-5p silencing. Also, miR-199a-5p inhibited SIRT1, promoted p21 acetylation, and upregulated p21 expression, thus accelerating nucleus pulposus cell apoptosis and IVDD. Overall, miR-199a-5p promotes nucleus pulposus cell apoptosis and IVDD by suppressing SIRT1-dependent deacetylation of p21.

Licochalcone A is a Natural SelectiveInhibitor of Arginine Methyltransferase 6.

Arginine methylation is a post-translational modification that is implicated in multiple biological functions including transcriptional regulation. The expression of protein arginine methyltransferases (PRMT) has been shown to be up-regulated in various cancers. PRMTs have emerged as attractive targets for the development of new cancer therapies. Here, we describe the identification of a natural compound, licochalcone A, as a novel, reversible and selective inhibitor of PRMT6. Since expression of PRMT6 is up-regulated in human breast cancers and is associated with oncogenesis, we used the human breast cancer cell line system to study the effect of licochalcone A treatment on PRMT6 activity, cell viability, cell cycle, and apoptosis. We demonstrated that licochalcone A is a non-S-adenosyl L-methionine (SAM) binding site competitive inhibitor of PRMT6. In MCF-7 cells, it inhibited PRMT6-dependent methylation of histone H3 at arginine 2 (H3R2), which resulted in a significant repression of estrogen receptor activity. Licochalcone A exhibited cytotoxicity towards human MCF-7 breast cancer cells, but not MCF-10A human breast epithelial cells, by up-regulating p53 expression and blocking cell cycle progression at G2/M, followed by apoptosis. Thus, licochalcone A has potential for further development as a therapeutic agent against breast cancer.

A novel ligand of the translationally controlled tumor protein (TCTP) identified by virtual drug screening for cancer differentiation therapy

SummaryIntroduction Differentiation therapy is a promising strategy for cancer treatment. The translationally controlled tumor protein (TCTP) is an encouraging target in this context. By now, this field of research is still at its infancy, which motivated us to perform a large-scale screening for the identification of novel ligands of TCTP. We studied the binding mode and the effect of TCTP blockade on the cell cycle in different cancer cell lines. Methods Based on the ZINC-database, we performed virtual screening of 2,556,750 compounds to analyze the binding of small molecules to TCTP. The in silico results were confirmed by microscale thermophoresis. The effect of the new ligand molecules was investigated on cancer cell survival, flow cytometric cell cycle analysis and protein expression by Western blotting and co-immunoprecipitation in MOLT-4, MDA-MB-231, SK-OV-3 and MCF-7 cells. Results Large-scale virtual screening by PyRx combined with molecular docking by AutoDock4 revealed five candidate compounds. By microscale thermophoresis, ZINC10157406 (6-(4-fluorophenyl)-2-[(8-methoxy-4-methyl-2-quinazolinyl)amino]-4(3H)-pyrimidinone) was identified as TCTP ligand with a KD of 0.87 ± 0.38. ZINC10157406 revealed growth inhibitory effects and caused G0/G1 cell cycle arrest in MOLT-4, SK-OV-3 and MCF-7 cells. ZINC10157406 (2 × IC50) downregulated TCTP expression by 86.70 ± 0.44% and upregulated p53 expression by 177.60 ± 12.46%. We validated ZINC10157406 binding to the p53 interaction site of TCTP and replacing p53 by co-immunoprecipitation. Discussion ZINC10157406 was identified as potent ligand of TCTP by in silico and in vitro methods. The compound bound to TCTP with a considerably higher affinity compared to artesunate as known TCTP inhibitor. We were able to demonstrate the effect of TCTP blockade at the p53 binding site, i.e. expression of TCTP decreased, whereas p53 expression increased. This effect was accompanied by a dose-dependent decrease of CDK2, CDK4, CDK, cyclin D1 and cyclin D3 causing a G0/G1 cell cycle arrest in MOLT-4, SK-OV-3 and MCF-7 cells. Our findings are supposed to stimulate further research on TCTP-specific small molecules for differentiation therapy in oncology.

MicroRNA-125b alleviates hydrogen-peroxide-induced abnormal mitochondrial dynamics in HT22 cells by inhibiting p53.

Micro-RNA125b (miR-125b) and tumor protein p53 (p53) are involved in the regulation of mitochondrial dynamics; however, the mechanism of their possible interaction during oxidative stress remains unclear. In this study, we investigated the role and mechanism of miR-125b and p53 in oxidative stress-induced mitochondrial damage in immortalized mouse hippocampal HT22 cells. Following stimulation with H2O2, we observed downregulation of miR-125b expression, upregulation of p53 expression, mitochondria were damaged and increased cell death. Overexpression of miR-125b alleviated mitochondrial damage and inhibited p53 expression. Furthermore, confocal and electron microscopy showed that overexpression of p53 eliminated the protective effect of miR-125b on the mitochondria. Thus, miR-125b alleviates abnormal mitochondrial homeostasis in H2O2-treated HT22 cells by suppressing p53 expression. Our data reveal a new model by which miR-125b influences mitochondrial dynamics.

Two species of Ulva inhibits the progression of cervical cancer cells SiHaby means of autophagic cell death induction.

Edible green algal seaweeds, namely Ulva intestinalis and Ulva lactuca constitute a significant repository of popular herbal medicines in the Traditional Chinese Medicinal system. The present study aimed to assess the anticancer potential of these algal members and its mode of action in cervical cancer cells SiHa. The algal samples primarily extracted in methanol was fractionated into hexane, chloroform, and aqueous algal fractions, which inhibited the proliferation of SiHa cells in a dose-dependent manner, with the algal chloroform fractions harbouring the lowest IC50 dose of 141.38µg/ml in U. intestinalis and 445.278µg/ml in U. lactuca. These algal chloroform fractions when studied for their in-depth mode of action, were found to damage and pulverise the nuclei, resulting in a concomitant increase in subG0-phase of SiHa cells, studied by flow cytometry. The algal treatment also caused an increase in the number of acidic vesicles and enhanced the expression of LC3BII, p62 and atg12 proteins, which together pointed out autophagy as the induced mode of cell death. Upregulated Bax and p53 expression along with decreased Bcl2 expression also correlated to autophagic cell death. Decreased expression of E6 viral oncogene was noted as a significant response to algal fractions. Lastly, these potent algal fractions when characterised pharmacologically through GC-MS analysis were found to be rich in unsaturated fatty acids, majorly palmitic acid. Hence, this study concludes that the two species of Ulva successfully decreased the proliferation of SiHa cervical cancer cells through autophagy, hinting at palmitic acid being the major responsible bioactive compound in both.

Regorafenib Suppresses Migration of and Induces Cell Cycle Arrest and Apoptosis in MCF-7 Cells

This study investigated the mechanism underlying the suppression of estrogen receptor-positive MCF-7 cell growth by regorafenib. MCF-7 cells were treated with regorafenib, and the effect of regorafenib on multiple cancer-associated pathways was evaluated. Although regorafenib effectively inhibited the proliferation of MCF-7 cells, it had no effect on the proliferation of the normal breast epithelial cell line MCF10A. Regorafenib suppressed MCF-7 cell migration, probably by regulating the homeostatic expression of matrix metalloproteinases and the tissue inhibitor of MMPs. Furthermore, it upregulated p21 expression, downregulated cyclin B1 and cyclin D1 expresssions, and caused cell cycle arrest. In addition, regorafenib induced apoptosis in MCF-7 cells by reducing Mcl-1 expression and activating caspase signaling. These results demonstrate that regorafenib has the potential to be an effective drug for treating breast cancer

MEF2A-mediated lncRNA HCP5 Inhibits Gastric Cancer Progression via MiR-106b-5p/p21 Axis.

Background: Long non-coding RNAs (lncRNAs) are deemed to be relevant to the tumorigenesis and development of a variety of tumors, containing gastric cancer (GC). The purpose of our investigations is to explore the character of HCP5 in GC.Methods: HCP5 expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in 62 matched GC tissues and corresponding para-carcinoma tissues. In vitro and in vivo functional assays were subjected to verify the biological effects of HCP5 after alteration of HCP5. Chromatin immunoprecipitation assay (CHIP) assays were conducted to confirm that myocyte enhancer factor 2A (MEF2A) could bind to HCP5 promoter regions and thereby induce HCP5 expression. Analysis of the latent binding of miR-106b-5p to HCP5 and p21 was made by bioinformatics prediction and luciferase reporter assays.Results: Significant downregulation of HCP5 was detected in GC tissues. Negative correlation was determined between HCP5 expression level and tumor size and overall survival in GC patients. HCP5 depletion had a facilitating impact on proliferation, migration and invasion of GC cells. Consistently, overexpression of HCP5 came into an opposite effect. Moreover, we demonstrated that MEF2A could combine with the promoter region of HCP5 and thereby induce HCP5 transcription. Luciferase reporter assays revealed that HCP5 could compete with miR-106b-5p as a competing endogenous RNA (ceRNA) and upregulated p21 expression in GC.Conclusions: MEF2A-mediated HCP5 could exert an anti-tumor effect among the development of GC via miR-106b-5p/p21 axis, which provides a novel target for GC therapy.

Sorafenib suppresses proliferation rate of fibroblast-like synoviocytes through the arrest of cell cycle in experimental adjuvant arthritis.

Rheumatoid arthritis, a recurrent incendiary autoimmune joint syndrome, features by prominent synovial hyperplasia. Fibroblast-like synoviocytes are the executive components in the pathogenesis of rheumatoid arthritis. It is generally accepted that excessive proliferation and reduced apoptosis of fibroblast-like synoviocytes lead to synovial hyperplasia. Our previously studies found that sorafenib could inhibit adjuvant arthritis in rats and induced adjuvant arthritis fibroblast-like synoviocytes apoptosis. Presently, we aim to investigate the inhibitory effect with mechanisms of action of sorafenib on adjuvant arthritis fibroblast-like synoviocytes proliferation. Cell counting kit-8 and flow cytometry detection were conducted to monitor FLSs proliferation and cell cycle. Western blotting and qPCR assays were performed to detect P21, P53, CDK4, CyclinD1 and proliferating cell nuclear antigen content levels. Sorafenib significantly inhibited adjuvant arthritis fibroblast-like synoviocytes proliferation with an IC50 value of 4 µmol/L by a concentration-dependent pattern, which accompanies by G1 cell cycle arrest. Also, sorafenib significantly decreased the levels of P21, CyclinD1, CDK4 and proliferating cell nuclear antigen, as well as up-regulated P53 expression in adjuvant arthritis fibroblast-like synoviocytes. Sorafenib could inhibit adjuvant arthritis fibroblast-like synoviocytes proliferation via arresting G1/S cell cycle progression, which was partially through CDK4/CyclinD1-mediated pathway, as well as up-regulating P53 and down-regulating proliferating cell nuclear antigen expressions. These results suggest that sorafenib may provide a new paradigm for rheumatoid arthritis treatment.

Mechanism Study of the Kidney Renal Papillary Cell Carcinoma Proliferation Inhibition and Apoptosis Induction by EZH2

EZH2 is an important target in a variety of tumors, but its role in KIRP (Kidney renal papillary cell carcinoma) has not yet been proven. The aim of this study was to investigate the role of EZH2 in KIRP patients. And to investigate the KIRP, we used two KIRP cell lines, SKRC39 and ACHN in this study. We used CCK8 assay and colony formation assay to study the effect of EHZ2 small molecule inhibitor EPZ6438 on cancer cell proliferation, we used Trypan Blue cell counting experiments to study the effect of EZH2 on cancer cell apoptosis, and we also used qRT-PCR to study the mechanism of EZH2 on cancer cell proliferation. The results showed that EZH2 was elevated in KIRP patients; inhibition of EZH2 could inhibit the proliferation of cancer cells and induce the apoptosis of cancer cells, which is valuable for the control of KIRP in patients. As for the mechanism, we found that inhibition of EZH2 upregulated P53 expression and thus activated this tumor suppressor gene, indicating why EHZ1 inhibits renal cancer cells.

Role of Dietary Antioxidants in p53-Mediated Cancer Chemoprevention and Tumor Suppression.

Cancer arises through a complex interplay between genetic, behavioral, metabolic, and environmental factors that combined trigger cellular changes that over time promote malignancy. In terms of cancer prevention, behavioral interventions such as diet can promote genetic programs that may facilitate tumor suppression; and one of the key tumor suppressors responsible for initiating such programs is p53. The p53 protein is activated by various cellular events such as DNA damage, hypoxia, heat shock, and overexpression of oncogenes. Due to its role in cell fate decisions after DNA damage, regulatory pathways controlled by p53 help to maintain genome stability and thus “guard the genome” against mutations that cause cancer. Dietary intake of flavonoids, a C15 group of polyphenols, is known to inhibit cancer progression and assist DNA repair through p53-mediated mechanisms in human cells via their antioxidant activities. For example, quercetin arrests human cervical cancer cell growth by blocking the G2/M phase cell cycle and inducing mitochondrial apoptosis through a p53-dependent mechanism. Other polyphenols such as resveratrol upregulate p53 expression in several cancer cell lines by promoting p53 stability, which in colon cancer cells results in the activation of p53-mediated apoptosis. Finally, among vitamins, folic acid seems to play an important role in the chemoprevention of gastric carcinogenesis by enhancing gastric epithelial apoptosis in patients with premalignant lesions by significantly increased expression of p53. In this review, we discuss the role of these and other dietary antioxidants in p53-mediated cell signaling in relation to cancer chemoprevention and tumor suppression in normal and cancer cells.

Diclofenac Sodium Triggers p53-Dependent Apoptosis in Human Corneal Epithelial Cells via ROS-Mediated Crosstalk.

Diclofenac sodium (DFS), a nonsteroidal anti-inflammatory drug, is frequently used in ophthalmology, but it causes negative effects on corneas. The mechanisms underlying the toxicities to corneas remains unclear. The present study was designed to assess the cytotoxicity of DFS to human corneal epithelial (HCEP) cells in vitro and further investigate its related mechanisms. The HCEP cells were treated with DFS at different concentrations ranging from 0.003 125% to 0.1%. DFS showed a dose- and time-dependent cytotoxicity to HCEP cells including abnormal morphology and declined viability. The 0.05% DFS-treated HCEP cells presented cell cycle arrest at S phase, reactive oxygen species (ROS) overproduction, and positive staining of phosphorylated H2AX, suggesting that DFS caused ROS-mediated DNA damage. The upregulation of p53 expression, formation of apoptotic body, phosphatidylserine externalization, and DNA ladder demonstrated that the p53-dependent apoptosis pathway was involved in the cytotoxicity of DFS. Furthermore, DFS activated caspase-8, caspase-9, and caspase-3 altered the expression levels of Bcl-2 family proteins including tBid, Bax, and Bcl-2, as well as increased poly(ADP-ribose) polymerase (PARP) cleavage. DFS also induced ΔΨm disruption, resulting in the release of cytochrome c and apoptosis-inducing factor into the cytoplasm. Additionally, the DFS-induced apoptosis was alleviated by p53 inhibitor. Taken together, DFS triggered p53-dependent apoptosis in HCEP cells via ROS-mediated crosstalk between the extrinsic and intrinsic pathways.

EGCG Enhanced the Anti-tumor Effect of Doxorubicine in Bladder Cancer via NF-κB/MDM2/p53 Pathway.

Doxorubicin (DOX), the first-line chemotherapy for bladder cancer, usually induces side effects. We previously demonstrated that green tea polyphenol EGCG had potent anti-tumor effect in bladder cancer via down regulation of NF-κB. This study aimed to investigate the additive/synergistic effect EGCG and DOX against bladder cancer. Our results demonstrated that the combined use of DOX and EGCG inhibited T24 and SW780 cell proliferation. EGCG enhanced the apoptosis induction effect of DOX in both SW780 and T24 cells and resulted in significant differences. Besides, EGCG promoted the inhibitory effect of DOX against bladder cancer cell migration. In addition, the in vivo results demonstrated that DOX in combination with EGCG showed the most potent anti-tumor effects among DOX, EGCG and DOX+EGCG treatment groups. Further mechanistic studies determined that the combination of DOX and EGCG inhibited phosphorylated NF-κB and MDM2 expression, and up-regulated p53 expression in tumor, as assessed by western blot and immunohistochemistry. Western blot in SW780 cells also confirmed that the combined use of EGCG and DOX caused significant increase in p53, p21, and cleaved-PARP expression, and induced significant inhibition in phosphorylated NF-κB and MDM2. When NF-κB was inhibited, the expression of p53 and p-MDM2 were changed, and the combination of DOX and EGCG showed no obvious effect in transwell migration and cell viability. In conclusion, the novel application of chemotherapy DOX and EGCG demonstrated potent anti-tumor, anti-migration and anti-proliferation effects against bladder cancer. EGCG enhanced the anti-tumor effect of DOX in bladder cancer via NF-κB/MDM2/p53 pathway, suggesting the potential clinical application against bladder cancer patients.

ET-06 Suppression of glioblastoma through novel drug based on “Gene Switch Technology”

Glioblastoma (GBM) is the most common and aggressive malignancy primarily affecting adults. Despite intensive multimodal therapies, the prognosis of GBM is dismal and a novel therapy is needed. Here, we focused on RUNX, a transcription factor involved in the malignant transformation of GBM, and developed a novel Chlorambucil-conjugated PI-polyamides (Chb-M’), which “switches off” RUNX family. Chb-M’ specifically recognizes the consensus RUNX-binding sequences (TGTGGT) and alkylates it to inhibit transcription of the downstream gene of RUNX family. Chb-M’ has been shown to induce apoptosis and suppress proliferation in a variety of cancers including leukemia, and in this study, similar results were found for glioblastoma cells in vitro. Specific inhibition of RUNX1 led to a marked inhibition of tumor growth through cell cycle arrest and apoptosis. By using apoptosis array, we isolated several candidate genes which regulated by RUNX1. And some types of glioblastoma cell lines treated with Chb-M’ showed elevated expression of p21 and decreased survivin. From in silico analysis using glioma patient cohorts, survivin expression was significantly higher in GBM and it was possibly involved in maintaining the malignancy of GBM. Mechanistically survivin was found to be directly transcriptionally regulated by RUNX1 through ChIP assay and reporter assay. In addition, survivin K/D cells upregulated p21 expression and accelerated apoptosis. Taken together, we hypothesized that the RUNX1-survivin-p21 pathway can potentially be exploited in the management of this malignancy. Chb-M’ mediated regulation of RUNX1 can be a novel therapeutic strategy against GBM.

Msx1 upregulates p27 expression to control cellular proliferation during valvuloseptal endocardial cushion formation in the chick embryonic heart.

Cushion tissues, the primordia of valves and septa of the adult heart, are formed in the atrioventricular (AV) and outflow tract (OFT) regions of the embryonic heart. The cushion tissues are generated by the endothelial-mesenchymal transition (EMT), involving many soluble factors, extracellular matrix, and transcription factors. Moreover, neural crest-derived mesenchymal cells also migrate into the OFT cushion. The transcription factor Msx1 is known to be expressed in the endothelial and mesenchymal cells during cushion tissue formation. However, its exact role in EMT during cushion tissue formation is still unknown. In this study, we investigated the expression patterns of Msx1 mRNA and protein during chick heart development. Msx1 mRNA was localized in endothelial cells of the AV region at Stage 14, and its protein was first detected at Stage 15. Thereafter, Msx1 mRNA and protein were observed in the endothelial and mesenchymal cells of the OFT and AV regions. in vitro assays showed that ectopic Msx1 expression in endothelial cells induced p27, a cell-cycle inhibitor, expression and inhibited fibroblast growth factor 4 (FGF4)-induced cell proliferation. Although the FGF signal reduced the EMT-inducing activities of transforming growth factor β (TGFβ), ectopic Msx1 expression in endothelial cells enhanced TGFβ signaling-induced αSMA, an EMT marker, expression. These results suggest that Msx1 may support the transformation of endothelial cells due to a TGFβ signal in EMT during cushion tissue formation.

Quinolinone inhibits proliferation of gastric cancer cells and induces their apoptosis via down-regulation of the expression of pro-oncogene c-Myc

Purpose: To determine the anti-proliferative potential of quinolinone against gastric cancer cells, and the underlying mechanism of action.Methods: Quinolinone-mediated proliferative changes were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, while its effect on apoptosis was determined by flow cytometry. Transwell and wound healing assays were used for the determination of the effect of quinolinone on cell invasion and migration. The effect of quinolinone on protein expression levels were assayed with western blotting.Results: Quinolinone caused reduction in gastric cancer cell viability, but it had no effect on normal (GES-1) cells. Treatment with 8 μM quinolinone reduced the viability of SNU-5 and SGC-7901 cells to 32 and 27 %, respectively. Moreover, 8 μM quinolinone induced 67.90 and 71.54 % apoptosis in SNU-5 and SGC-7901 cells, respectively. Quinolinone significantly increased the population of cells in G1 phase, and suppressed migration potential (p < 0.05). Furthermore, in quinolinone-treated cells, the expression levels of p-PI3K, c-Myc and p-AKT were much lower than those in untreated cells (p < 0.05). Quinolinone also downregulated the expressions of MMP-2 and MMP-9, while it upregulated p21 expression in SNU-5 and SGC-7901 cells.Conclusion: Quinolinone suppresses the growth of SNU-5 and SGC-7901 gastric cancer cells via cell cycle arrest, induction of apoptosis and downregulation of the expressions of c-Myc and metalloproteinases. Thus, quinolinone may be developed as a potential drug candidate for the treatment of gastric cancer.
 Keywords: Gastric cancer, Apoptosis, Metalloproteinases, Phosphorylation

Lung cancer‑associated transcript 1 facilitates tumorigenesis in laryngeal squamous cell carcinoma through the targeted inhibition of miR‑493.

Long non-coding RNAs (lncRNAs) serve important roles in the tumorigenesis of a diverse range of cancer types. The lung cancer-associated transcript 1 (LUCAT1), has been reported to promote the proliferation, migration and invasion of oral squamous cell carcinoma cells. However, the exact role of LUCAT1 in laryngeal squamous cell carcinoma (LSCC) remains to fully understood. The present study aimed to interrogate the role and modulatory mechanism of LUCAT1 in LSCC. Reverse transcription-quantitative PCR and western blotting were used to investigate the expression of LUCAT1 and miR-493, as well as the protein expression of cyclin-dependent kinase 2, cyclin E1, p21, matrix metalloproteinase (MMP)2, MMP9, vascular endothelial growth factor-C, Bcl-2, Bax, cleaved caspase-3 and procaspase-3. Cell Counting Kit-8, flow cytometry, wound healing and Transwell assays were performed to analyze the proliferation, cell cycle, apoptosis levels, and the migratory and invasive abilities, respectively, of the LSCC AMC-HN-8 cell line. In addition, dual-luciferase reporter and ribonucleoprotein immunoprecipitation assays were used to investigate the binding between LUCAT1 and microRNA (miR)-493. The results of the present study revealed that the expression levels of LUCAT1 were upregulated in AMC-HN-8 cells. The genetic knockdown of LUCAT1 expression levels significantly suppressed the cell proliferation, alongside downregulating the expression levels of CDK2 and cyclin E1 and upregulating p21 expression levels. In addition, the knockdown of LUCAT1 inhibited cell migration and invasion, as demonstrated using the wound healing and Transwell assays, respectively. Moreover, LUCAT1 knockdown promoted cell apoptosis and upregulated the expression levels of Bax and cleaved caspase-3, whilst downregulating the expression levels of Bcl-2. Furthermore, LUCAT1 was discovered to directly bind to and inhibit the well-known tumor suppressor, miR-493. Notably, the specific inhibition of miR-493 partly blocked the anticancer effects of LUCAT1 knockdown in AMC-HN-8 cells. In conclusion, these results suggested that LUCAT1 may facilitate tumorigenesis in LSCC through the targeted inhibition of miR-493, which provides evidence for a novel target for the treatment of LSCC.

Overexpression of p53 accelerates puberty in high-fat diet-fed mice through Lin28/let-7 system.

High-fat intake and subsequent obesity are associated with premature onset of puberty, but the exact neuroendocrine mechanisms are still unclear. The transcriptional factor p53 has been predicted to be a central hub of the gene networks controlling the pubertal onset. Besides, p53 also plays crucial roles in metabolism. Here, we explored p53 in the hypothalami of mice fed a high-fat diet (HFD), which showed an up-regulated expression. Besides, we also revealed that overexpressed p53 may accelerate hypothalamo-pituitary-gonadal (HPG) axis activation partially through the c-Myc/Lin28/let-7 system. These results can deepen our understanding of the interaction between metabolic regulation and puberty onset control, and may shed light on the neuroendocrine mechanisms of obesity-related central precocious puberty.