Trilobolide-6-O-isobutyrate exerts anti-tumor effects on cholangiocarcinoma cells through inhibiting JAK/STAT3 signaling pathway.

Trilobolide-6-O-isobutyrate exhibits significant antitumor effects on cholangiocarcinoma (CCA) cells by effectively inhibiting the JAK/STAT3 signaling pathway. This study aims to investigate the mechanisms underlying the antitumor properties of trilobolide-6-O-isobutyrate, and to explore its potential as a therapeutic agent for CCA. This study illustrates that trilobolide-6-O-isobutyrate efficiently suppresses CCA cell proliferation in a dose- and time-dependent manner. Furthermore, trilobolide-6-O-isobutyrate stimulates the production of reactive oxygen species, leading to oxidative stress and initiation of apoptosis via the activation of the mitochondrial pathway. Data from xenograft tumor assays in nude mice confirms that TBB inhibits tumor growth, and that there are no obvious toxic effects or side effects in vivo. Mechanistically, trilobolide-6-O-isobutyrate exerts antitumor effects by inhibiting STAT3 transcriptional activation, reducing PCNA and Bcl-2 expression, and increasing P21 expression. These findings emphasizes the potential of trilobolide-6-O-isobutyrate as a promising therapeutic candidate for the treatment of CCA.

DPY30 promotes colorectal carcinoma metastasis by upregulating ZEB1 transcriptional expression.

DPY30 belongs to the core subunit of components of the histone lysine methyltransferase complex, which is implicated in tumorigenesis, cell senescence, and other biological events. However, its contribution to colorectal carcinoma (CRC) progression and metastasis has yet to be elucidated. Therefore, this study aimed to investigate the biological function of DPY30 in CRC metastasis both in vitro and in vivo. Herein, our results revealed that DPY30 overexpression is significantly positively correlated with positive lymph nodes, epithelial-mesenchymal transition (EMT), and CRC metastasis. Moreover, DPY30 knockdown in HT29 and SW480 cells markedly decreased EMT progression, as well as the migratory and invasive abilities of CRC cells in vitro and lung tumor metastasis in vivo. Mechanistically, DPY30 increased histone H3K4me3 level and promoted EMT and CRC metastasis by upregulating the transcriptional expression of ZEB1. Taken together, our findings indicate that DPY30 may serve as a therapeutic target and prognostic marker for CRC.

RARγ promotes the invasion and metastasis of thyroid carcinoma by activating the JAK1-STAT3-CD24/MMPs axis.

The nuclear receptor superfamily RAR is generally considered to play a crucial role in the development of tumors by regulating the transcription of target genes. Nevertheless, whether RARγ performs tumor-promoting or tumor-suppressing functions and its specific mechanism in thyroid carcinoma (TC) remain unknown. Here, our study demonstrated that RARγ was abnormally overexpressed in TC tissues compared with normal thyroid tissues. Moreover, RARγ expression was remarkably correlated with cell phenotypes such as cell proliferation, migration and invasion. Mechanistically, RARγ knockdown effectively decreased the phosphorylation levels of JAK1 and STAT3, leading to decreased expression of the membrane protein CD24. In a coculture system, TC cells with high levels of CD24 in the membrane were more likely to escape phagocytosis by macrophages via the combination of CD24 with the inhibitory receptor Siglec-10 in the membrane of macrophages. In contrast, the ability of macrophages to engulf TC cells was notably elevated through exogenous addition of CD24 antibody. Collectively, our study revealed a previously undiscovered molecular mechanism of RARγ in promoting the development of TC, shedding light on RARγ as a promising therapeutic target for TC.

DPY30 Promotes Proliferation and Cell Cycle Progression of Colorectal Cancer Cells via Mediating H3K4 Trimethylation.

DPY30, a core subunit of the SET1/MLL histone H3K4 methyltransferase complexes, plays an important role in diverse biological functions through the epigenetic regulation of gene transcription, especially in cancer development. However, its involvement in human colorectal carcinoma (CRC) has not been elucidated yet. Here we demonstrated that DPY30 was overexpressed in CRC tissues, and significantly associated with pathological grading, tumor size, TNM stage, and tumor location. Furthermore, DPY30 knockdown remarkably suppressed the CRC cell proliferation through downregulation of PCNA and Ki67 in vitro and in vivo, simultaneously induced cell cycle arrest at S phase by downregulating Cyclin A2. In the mechanistic study, RNA-Seq analysis revealed that enriched gene ontology of cell proliferation and cell growth was significantly affected. And ChIP result indicated that DPY30 knockdown inhibited H3 lysine 4 trimethylation (H3K4me3) and attenuated interactions between H3K4me3 with PCNA, Ki67 and cyclin A2 respectively, which led to the decrease of H3K4me3 establishment on their promoter regions. Taken together, our results demonstrate overexpression of DPY30 promotes CRC cell proliferation and cell cycle progression by facilitating the transcription of PCNA, Ki67 and cyclin A2 via mediating H3K4me3. It suggests that DPY30 may serve as a potential therapeutic molecular target for CRC.

Retinoic Acid Receptor Gamma (RARγ) Promotes Cartilage Destruction through Positive Feedback Activation of NF-κB Pathway in Human Osteoarthritis.

Osteoarthritis (OA) is a severe inflammation-related disease which leads to cartilage destruction. The retinoic acid receptor gamma (RARγ) has been indicated to be involved in many inflammation processes. However, the role and mechanism of RARγ in cartilage destruction caused by inflammation in OA are still unknown. Here, we demonstrated that the RARγ was highly expressed in chondrocytes of OA patients compared with healthy people and was positively correlated with the damage degree of cartilage in OA. Cytokine TNF-α promoted the transcription and expression of RARγ through activating the NF-κB pathway in OA cartilage. In addition, the overexpression of RARγ resulted in the upregulation of matrix degradation and inflammation associated genes and downregulation of differentiation and collagen production genes in human normal chondrocyte C28/I2 cells. Mechanistically, overexpression of RARγ could increase the level of p-IκBα and p-P65 to regulate the expression of downstream genes. RARγ and IκBα also could interact with each other and had the same localization in C28/I2 cells. Moreover, the SD rats OA model induced by monosodium iodoacetate indicated that CD437 (RARγ agonist) and TNF-α accelerated the OA progression, including more severe cartilage layer destruction, larger knee joint diameter, and higher serum ALP levels, while LY2955303 (RARγ inhibitor) showed the opposite result. RARγ was also highly expressed in OA group and even higher in TNF-α group. In conclusion, RARγ/NF-κB positive feedback loop was activated by TNF-α in chondrocyte to promote cartilage destruction. Our data not only propose a novel and precise molecular mechanism for OA disease but also provide a prospective strategy for the treatment.

Trilobolide-6-O-isobutyrate suppresses hepatocellular carcinoma tumorigenesis through inhibition of IL-6/STAT3 signaling pathway.

Currently available therapies for hepatocellular carcinoma (HCC), with a high morbidity and high mortality, are only marginally effective and with sharp adverse side effects, which makes it compulsory to explore novel and more effective anticancer molecules. Chinese medicinal herbs exhibited prominent anticancer effects and were applied to supplement clinical cancer treatment. Here, we reported a compound, trilobolide-6-O-isobutyrate (TBB), isolated from the flowers of Wedelia trilobata with a markedly cytotoxic effect on HCC cells. We found that TBB time- and dose-dependently inhibited HCC cells' growth and colony formation in vitro. Moreover, TBB induced cell cycle arrest at the G2/M phase, mitochondrial caspase-dependent apoptosis, and suppressed migration and invasion, as well as the glycolysis of HCC cells. Mechanistically, our data indicated that TBB inhibited the STAT3 pathway activation by directly interacting with the TYR 640/657 sites of the STAT3 protein and decreasing the level of p-STAT3. TBB also regulated the expression of PCNA, Ki67, Cyclin B1, Cyclin E, Bax, Bcl2, MMP2/9, and PGK1 through the inhibition of the IL-6/STAT3 signaling pathway. Lastly, we confirmed that TBB effectively eliminated tumor growth without causing overt toxicity to healthy tissues in the xenograft tumor model. The exploration of anticancer activity and the underlying mechanism of TBB suggested its usage as a promising chemotherapeutic agent for HCC.

Diosgenin exerts anti-tumor effects through inactivation of cAMP/PKA/CREB signaling pathway in colorectal cancer.

Colorectal cancer (CRC) is the most fatal gastrointestinal tumor and it is urge to explore powerful drugs for the treatment. Diosgenin (DSG) as a new steroidal had been reported exerts anti-tumor activity in multiple cancers, including CRC. However, the potential mechanism of DSG suppresses CRC remains further to be revealed. Here, we reported that DSG inhibited proliferation of CRC cells in dose- and time-dependent manner, induced apoptosis by modulating p53 and Bcl-2 family proteins expression to mediate mitochondrial apoptosis pathway, suppressed migration and invasion by reducing MMP-9 (matrix metalloproteinase) and decreased aerobic glycolysis by mediating glucose transporter (GLUT) like GLUT3 and GLUT4, and pyruvate carboxylase PC downregulation. Intriguingly, mechanistic study suggests those phenotypes involved DSG inhibited cAMP/PKA/CREB pathway in CRC cells, and result to inhibit the phosphorylation of CREB to regulate the transcription of genes above-mentioned. Finally, nude mice xenograft tumor model further indicated that DSG could be a great agent to suppress the growth of CRC cells in vivo and have no obvious side effects. Taken together, we revealed a unique mechanism that DSG suppresses CRC cells through cAMP/PKA/CREB pathway and DSG is a promising candidate drug for CRC treatment.

Protective effects of orally administered shark compound peptides from Chiloscyllium plagiosum against acute inflammation.

The anti-inflammatory effects of shark compound peptides (SCP) from Chiloscyllium plagiosum were investigated. Results showed that SCP enhanced the viability of RAW 264.7 macrophages in vitro in a dose-dependent manner. Orally administered SCP exhibited potent anti-inflammatory activity in lipopolysaccharide (LPS)-challenged mice by suppressing serum levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), as well as nitric oxide (NO). Moreover, SCP significantly inhibited the inflammatory rise of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and creatinine (CRE), while blocking the decline of cholinesterase (CHE), with an efficacy close to aspirin. This research showed that orally administered SCP from C. plagiosum notably downregulated uncontrolled inflammatory responses, and conferred substantial protection from endotoxin-induced acute hepatic damage and renal functional impairment. Therefore, oral supplementation of SCP can be used as a preventive approach to reduce the risk of inflammatory-related diseases.

Plasma levels of Interleukin 18 but not amyloid-ß or Tau are elevated in female depressive patients.

BACKGROUND: Depression is associated with inflammation and Alzheimer's disease (AD). However, detailed molecular mechanisms linking mood, neuroinflammation and AD remain unclear. Although changes in peripheral inflammatory factors such as Interleukin 18 (IL18), and AD-associated amyloid-ß (Aß) peptides have been linked to depression, a solid relationship between these factors in depressive disorder has yet to be established. This study aims to further determine whether plasma IL18, Aß40, Aß42, and the AD-associated tangle component Tau, as well as IL18 single nucleotide polymorphisms (SNPs) may be biomarkers for depression. METHODS: We measured plasma IL18, Aß40, Aß42, and Tau in 64 depressive patients and 75 healthy controls, and characterized genotypes of three IL18 SNPs (rs187238, rs1946518 and rs1946519) in these subjects. Comparisons between depressive patients and controls were carried out in males, in females or in combination. Regression analyses were conducted to examine the correlation between these parameters. RESULTS: We found that none of the plasma levels of IL18, Aß40, Aß42, and Tau, the ratio of Aß42/Aß40, and the genotypes of IL18 SNPs were significantly different between combined depressive patients and combined healthy controls, or between male depressive patients and male controls. However, IL18 levels were less in females than in males in healthy people and were significantly increased in female depressive patients compared to female controls. Moreover, IL18 and standardized IL18 were correlated with standardized Aß42/Aß40 ratio and standardized Tau in depressive patients. CONCLUSIONS: Plasma IL18 may be a potential biomarker for depression in women.

An Ultrasound Model to Predict the Short-Term Effects of Endovascular Stent Placement in the Treatment of Carotid Artery Stenosis.

Purpose: The present study aimed to explore the predictive ability of an ultrasound linear regression equation in patients undergoing endovascular stent placement (ESP) to treat carotid artery stenosis-induced ischemic stroke. Methods: Pearson's correlation coefficient of actual improvement rate (IR) and 10 preoperative ultrasound indices in the carotid arteries of 64 patients who underwent ESP were retrospectively analyzed. A predictive ultrasound model for the fitted IR after ESP was established. Results: Of the 10 preoperative ultrasound indices, peak systolic velocity (PSV) at stenosis was strongly correlated with postoperative actual IR (r = 0.622; P < 0.01). The unstable plaque index (UPI; r = 0.447), peak eccentricity ratio (r = 0.431), and plaque stiffness index (ß; r = 0.512) moderately correlated with actual IR (P < 0.01). Furthermore, the resistance index (r = 0.325) and the dilation coefficient (r = 0.311) weakly correlated with actual IR (P < 0.05). There was no significant correlation between actual IR and the number of unstable plaques, area narrowing, pulsatility index, and compliance coefficient. In combination, morphological, hemodynamic, and physiological ultrasound indices can predict 62.39% of neurological deficits after ESP: fitted IR = 0.9816 - 0.1293ß + 0.0504UPI - 0.1137PSV. Conclusion: Certain carotid ultrasound indices correlate with ESP outcomes. The multi-index predictive model can be used to evaluate the effects of ESP before surgery.

The inhibitory kinetics and mechanism of glycolic acid on lipase.

Obesity is prone to cause a variety of chronic metabolic diseases, and it has aroused people's attention that the rapid increase in the global population of obese people in the past years. As a kind of weight-loss drug acting in the intestine, lipase inhibitor does not enter the bloodstream without producing central nervous side effects. Because they do not affect the metabolism system, lipase inhibitors and obesity have become one of the hot spots in recent years. Glycolic acid is a new substrate analog inhibitor with the value of the semi-inhibitory concentration of lipase is estimated to be 17.29 ± 0.14 mM. Using the plots of Lineweaver-Burk, the inhibition mechanism of lipase by glycolic acid was reversible and the inhibition type belongs to competitive inhibition with a KI value of 19.61 ± 0.26 mM. The inhibitory kinetics assay showed that the microscopic velocity constant k+0 of inhibition kinetics is 1.79 × 10-3 mM-1s-1, and k-0 is 0.73 × 10-3 s-1. The results of UV full-wavelength scanning on product cumulative, fluorescence quenching and molecular simulation also indicated that glycolic acid and substrate competitive with lipase by binding to Lys137. Thereby glycolic acid inhibiting the oxidation-catalyzed reaction and reducing the product of the enzyme and substrate. This adds a new direction for the search for lipase inhibitors and provides new ideas about the development of anti-obesity drugs.Communicated by Ramaswamy H. Sarma.

Upregulation of DPY30 promotes cell proliferation and predicts a poor prognosis in cholangiocarcinoma.

OBJECTIVES: Modification of lysine 4 on histone H3 methylation by SET1 and MLL family methyltransferase complexes is tightly linked to cancer progression. DPY30 is an important subunit of SET1 and MLL complexes, however, its expression and roles in cancer progression was little known, especially in cholangiocarcinoma (CCA). MATERIALS AND METHODS: The Q-PCR and IHC were performed to detect the levels of DPY30 mRNA and protein in CCA tissues. Effect of DPY30 knockdown on the proliferation of CCA cells was detected by MTS and colony formation, and cell cycle distribution was analyzed by flow cytometer. The glucose uptake, lactate release and ATP production assays were performed to detect the glycolysis of CCA cells. RESULTS: The level of DPY30 mRNA and protein in CCA tissues were all significantly higher than that of pericancer tissues, and its upregulation was closely associated with pathological differentiation, tumor size, and TNM stage. In addition, Kaplan-Meier analysis of overall survival revealed that DPY30 upregulation was significantly associated with poor survival, and univariate and multivariate analysis indicated that it was an independently prognosis factor in CCA patients. Moreover, DPY30 knockdown inhibited in-vitro growth and induced cell cycle arrest at G2/M and decreased glycolysis in CCA cells. CONCLUSIONS: DPY30 upregulation may promote the development of CCA and was associated with the aggressive malignant behavior and poor survival outcome of CCA patients. DPY30 might serve as a potential novel target for treatment of CCA patients.

Diosgenin Suppresses Cholangiocarcinoma Cells Via Inducing Cell Cycle Arrest And Mitochondria-Mediated Apoptosis.

PURPOSE: Diosgenin (DSG) is the precursor of steroid hormones and plays a crucial part in the proliferation of various carcinomas including human colorectal cancer and gastric carcinoma. Nevertheless, its specific features and mechanisms in human cholangiocarcinoma (CCA) remain unknown. METHODS: MTS assay, colony-forming assay, and EdU assay were performed to determine the role of DSG on the progression of human CCA cells. The distributions of cell cycle, the ratio of apoptosis, and the mitochondrial membrane potential (ΔΨm) were studied by flow cytometry (FCM). AO/EB and Hoechst 33258 staining were performed to observe the morphological features of cell apoptosis. TEM was performed to observe the ultrastructures of QBC939 and HuCCT1 cells. The mRNA and protein expression of mitochondrial apoptotic pathway and GSK3ß/ß-catenin pathway were further confirmed by qPCR and Western blotting. The xenograft tumor model of HuCCT1 cells was built. Immunohistochemistry of tumor tissues was performed. RESULTS: Our results indicated that DSG inhibited the progression of six CCA cell lines. In vivo tumor studies also indicated that DSG significantly inhibited tumor growth in xenografts in nude mice. The expression of mitosis-promoting factor cyclinB1 was decreased along with the elevating level of cell cycle inhibitor p21, resulting in arresting CCA cell cycles at G2/M phase. Furthermore, DSG induced apoptosis with the increased expressions of cytosol cytochrome C, cleaved-caspase-3, cleaved-PARP1 and the Bax/Bcl-2 ratio. Mechanistically, our study showed that GSK3ß/ß-catenin pathway was involved in the apoptosis of CCA cells. Thus, DSG might provide a new clue for the drug therapy of CCA. CONCLUSION: In our data, DSG was found to have efficient antitumor potential of human CCA cells in vitro and in vivo.

Association between IL-1B gene polymorphisms and Helicobacter pylori infection: A meta-analysis.

BACKGROUND: To clarify the impact of IL-1B gene polymorphisms (IL-1B-511C/T, IL-1B-31C/T, IL-1B+3954C/T) in Helicobacter pylori (H. pylori) infection by mean of a meta-analysis. METHODS: The relevant studies were retrieved from PubMed, Web of Science, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases until September 9, 2018. Odds ratio (OR) and its 95% confidence intervals (CIs) were used to assess the associations. Statistical analyses of this meta-analysis were conducted by using STATA 12 software. RESULTS: Totally, 45 articles including 9606 cases and 5654 controls were enrolled in this meta-analysis. Our results indicated that IL-1B-511C/T polymorphism was significantly related to an increased the risk of H. pylori infection under recessive model (OR = 1.13, 95% CI: 1.00-1.27, P = 0.048). However, no significant associations were obtained between H. pylori infection and IL-1B-31C/T as well as IL-1B+3954C/T polymorphisms under all models. In addition, subgroup analyses were also performed by country, study design, and detection methods of H. pylori. CONCLUSIONS: This meta-analysis suggested that IL-1B-511C/T polymorphism was related to the risk of H. pylori infection. Further larger studies with high quality are needed to conform these findings.

Retinoic acid receptor α facilitates human colorectal cancer progression via Akt and MMP2 signaling.

Purpose: Retinoic acid α (RARα) is overexpressed in various tumors and facilitates cancer progression. Although RARα has been shown to facilitate colorectal cancer (CRC) progression, more efforts to characterize mechanisms of RARα in CRC are needed in order to develop better target-based drugs for tumor therapy. Methods: RARα expression in CRC was assessed by IHC. EdU, QPCR, Western blotting, dual-luciferase reporter assay and ChIP were performed to explore the role of RARα in CRC and the mechanism involoved. Results: Here, we show an overexpression of RARα in 73.5% (i.e., 25 of 34 human CRC specimens). RARα knockdown decreased cell proliferation, migration, and invasion. Such phenotypic manifestations can be correlated to lowered activation of Akt and expression of PCNA (proliferating cell nuclear antigen) as well as MMP2 (matrix metallopeptidase). Mechanistically, RARα facilitates CRC growth through Akt signaling activation to cause levels of PCNA to be upregulated. Furthermore, RARα promotes migration and invasion of CRC cells by directly recruiting the MMP2 promoter to enhance the expression of MMP2. Conclusions: These findings demonstrate that CRC carcinogenesis is promoted by RARα via an enhanced Akt signaling and by increasing MMP2 transcription. CRC therapy can examine the use of RARα as a prospective molecular target.

Tankyrase Promotes Aerobic Glycolysis and Proliferation of Ovarian Cancer through Activation of Wnt/ß-Catenin Signaling.

Tankyrase (TNKS) plays important roles in the malignancy of several cancers such as human lung tumor, breast cancer, and hepatocellular cancer. However, its exact functions and molecular mechanisms in ovarian cancer remain unclear. In this study, we found that TNKS was aberrantly overexpressed in human ovarian cancer tissues and associated with poor patient prognosis. TNKS inhibition or knockdown not only reduced ovarian cancer cell proliferation, colony formation, migration, invasion, and tumorigenic potential in nude mice but also enhanced the drug susceptibility of ovarian cancer cells through arresting cell cycle and inducing apoptosis. These phenotypic changes correlated with downregulation of targets (Cyclin D1, MDR, and MMP-9) of Wnt/ß-catenin signaling. Furthermore, downregulation of TNKS suppressed the glucose uptake, lactate excretion, and cellular ATP levels and increased cellular O2 consumption rates. Molecular mechanism studies revealed that TNKS promoted aerobic glycolysis at least in part due to upregulation of pyruvate carboxylase (PC) via activation of Wnt/ß-catenin/snail signaling. In agreement with these findings, expression of TNKS is positively associated with snail and PC in clinical ovarian cancer samples. Our findings identified TNKS as an oncogenic regulator of ovarian cancer cells proliferation that promotes aerobic glycolysis via activation of Wnt/ß-catenin signaling, indicating that the TNKS might serve as a potential molecular target for clinical therapy of Wnt/ß-catenin dependent ovarian cancer.

Correlation Between Tumor Vasculogenic Mimicry and Poor Prognosis of Human Digestive Cancer Patients: A Systematic Review and Meta-Analysis.

Vasculogenic mimicry (VM) is a new pattern of blood supplement independent of endothelial vessels, which is related with tumor invasion, metastasis and prognosis. However, the role of VM in the prognosis of cancer patients is controversial. This study aimed to perform a meta-analysis of the published data to attempt to clarify the prognostic value of VM in the digestive cancer. Relevant studies were retrieved from the PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure and VIP databases published before March 29, 2018. Studies were included if they detected VM in the digestive cancer and analyzed the overall survival (OS) or disease-free survival (DFS) according to VM status. Two independent reviewers screened the studies, extracted data, and evaluated the quality of included studies with the Newcastle-Ottawa scale. Meta-analysis was performed using STATA 12.0 software. A total of 22 studies with 2411 patients were included in this meta-analysis. Meta-analysis showed that VM was related with the poor OS (HR = 2.30, 95% CI: 2.06-2.56, P < 0.001) and DFS (HR = 2.60, 95% CI: 2.07-3.27, P < 0.001) of patients with digestive cancer. Subgroup analysis showed VM was related with tumor differentiation, lymph node metastasis and TNM stage. Moreover, the present meta-analysis was reliable, and there was no obvious publication bias. This meta-analysis suggested that VM was a poor prognosis of digestive cancer patients. Further large and well-designed studies are required.

Apoptosis induced by ursodeoxycholic acid in human melanoma cells through the mitochondrial pathway.

Ursodeoxycholic acid (UDCA) is a type of hydrophilic bile acid extracted from animal bile with a wide range of biological functions. The present results demonstrated that UDCA could effectively inhibit the proliferation of two human melanoma cell line (M14 and A375) with time­ and concentration­dependence. Following exposure to various concentrations of UDCA, M14 cells exhibited typical morphological changes and weaker ability of colony forming. Flow cytometry analysis demonstrated that UDCA could induce a decrease of mitochondrial membrane potential and an increase in reactive oxygen species (ROS) levels in M14 cells. The cell cycle was arrested in the G2/M phase, which was confirmed by the decrease of cyclin­dependent kinase 1 and cyclinB1 at the protein level. However, when M14 cells were treated with UDCA and Z­VAD­FMK (caspase inhibitor) synchronously, the apoptosis rate of the cells was reduced significantly. In addition, it was demonstrated that UDCA induced apoptosis of human melanoma M14 cells through the ROS­triggered mitochondrial­associated pathway, which was indicated by the increased expression of cleaved­caspase­3, cleaved­caspase­9, apoptotic protease activating factor­1, cleaved­poly (ADP­ribose) polymerase 1 and the elevation of B cell lymphoma­2 (Bcl­2) associated X protein/Bcl­2 ratio associated with apoptosis. Therefore, UDCA may be a potential drug for the treatment of human melanoma.

Retinoic Acid Receptor α Knockdown Suppresses the Tumorigenicity of Esophageal Carcinoma via Wnt/ß-catenin Pathway.

BACKGROUND: Aberrant expression of retinoic acid receptor α (RARα) was correlated with diverse carcinomas such as acute promyelocytic leukemia and colorectal carcinoma. Nevertheless, the function and mechanism of RARα in esophageal carcinoma (EC) remain unclear. AIM: To investigate the expression of RARα in EC and its effect in the tumorigenesis of EC. METHODS AND RESULTS: In immunohistochemistry study, RARα was overexpressed in human EC tissues, and its overexpression was closely related to the pathological differentiation, lymph node metastasis, and clinical stages in EC patients. Functionally, RARα knockdown suppressed the proliferation and metastasis of EC cells through downregulating the expression of PCNA, Ki67, MMP7, and MMP9, as well as enhanced drug susceptibility of EC cells to 5-fluorouracil and cisplatin. Mechanistically, RARα knockdown inhibited the activity of Wnt/ß-catenin pathway through reducing the phosphorylation level of GSK3ß at Ser-9 and inducing phosphorylation level at Tyr-216, which resulted in downregulation of its downstream targets such as MMP7, MMP9, and P-gP. CONCLUSIONS: Our results demonstrated that RARα knockdown suppressed the tumorigenicity of EC via Wnt/ß-catenin pathway. RARα might be a potential molecular target for EC clinical therapy.

Chibby suppresses aerobic glycolysis and proliferation of nasopharyngeal carcinoma via the Wnt/ß-catenin-Lin28/let7-PDK1 cascade.

BACKGROUND: Great progress has been achieved in the study of the aerobic glycolysis or the so-called Warburg effect in a variety of cancers; however, the regulation of the Warburg effect in Nasopharyngeal carcinoma (NPC) has not been completely defined. METHODS: Gene expression pattern of NPC cells were used to test associations between Chibby and ß-catenin expression. Chibby siRNAs and over-expression vector were transfected into NPC cells to down-regulate or up-regulate Chibby expression. Loss- and gain-of function assays were performed to investigate the role of Chibby in NPC cells. Western blot, cell proliferation, Glucose uptake, Lactate release, ATP level, and O2 consumption assays were used to determine the mechanism of Chibby regulation of underlying targets. Finally, immunohistochemistry assay of fresh NPC and nasopharyngeal normal tissue sample were used to detect the expression of Chibby, ß-Catenin, and PDK1 by immunostaining. RESULTS: We observed that Chibby, a ß-catenin-associated antagonist, is down-regulated in nasopharyngeal carcinoma cell lines and inhibits Wnt/ß-Catenin signaling induced Warburg effect. Mechanism study revealed that Chibby regulates aerobic glycolysis in NPC cells through pyruvate dehydrogenase kinase 1(PDK1), an important enzyme involved in glucose metabolism. Moreover, Chibby suppresses aerobic glycolysis of NPC via Wnt/ß-Catenin-Lin28/let7-PDK1 cascade. Chibby and PDK1 are critical for Wnt/ß-Catenin signaling induced NPC cell proliferation both in vitro and in vivo. Finally, immunostaining assay of tissue samples provides an important clinical relevance among Chibby, Wnt/ß-Catenin signaling and PDK1. CONCLUSIONS: Our study reveals an association between Chibby expression and cancer aerobic glycolysis, which highlights the importance of Wnt/ß-catenin pathway in regulation of energy metabolism of NPC. These results indicate that Chibby and PDK1 are the potential target for NPC treatment.