NGX6 inhibits cell invasion and adhesion through suppression of Wnt/beta-catenin signal pathway in colon cancer

Parecoxib expresses anti-metastasis effect through inhibition of epithelial-mesenchymal transition and the Wnt/β-catenin signaling pathway in human colon cancer DLD-1 cell line

Colorectal cancer is the third leading cause of cancer death in Taiwan. Current treatments involve combination of surgical resection, radiation, and chemotherapy. These treatments have demonstrated to increased five-year survival of a patient with colorectal cancer. However, metastasis is a major capability of cancer cells that causes poor prognosis, recurrence, and even death. Epidemiological and clinical studies have suggested the use of non-steroidal anti-inflammatory drugs (NSAIDs) as an effective class of compounds to prevent colon cancer. Parecoxib is an NSAID and the only parenterally administered selective cyclooxygenase (COX)-2 inhibitor. In this study, we evaluated whether parecoxib inhibits the metastasis of DLD-1 human colon cancer cells, a COX-2 null cell line, and the underlying mechanism. Cell migration of the DLD-1 cells was significantly inhibited by parecoxib treatment as shown by the Transwell migration assay. This enhanced anti-migration effect was correlated with the attenuated phosphorylation of Akt, expression of vimentin (a mesenchymal marker), and β-catenin, and corresponded with the upregulated GSK3β and E-cadherin (an epithelial marker). These findings suggested that parecoxib could inhibit the epithelial-mesenchymal transition (EMT) and metastasis in human colon cancer cells by downregulating β-catenin. Thus, parecoxib could provide a novel prospective strategy for a combination treatment with chemotherapeutic drugs against metastasis of human colon cancer.

Association of TMEM8B and SPAG8 with Mature Weight in Sheep

Simple Summary

Domestication and the subsequent selection of animals for either economic or morphological features can impact the legacy genome of a population in myriad ways. In sheep, the rs426272889 single nucleotide polymorphism (SNP) was identified as the peak of a signature of selection. We examined phenotypic data and identified associations for the Transmembrane protein 8B (TMEM8B) rs426272889 SNP and its genetically linked Sperm-associated antigen 8 (SPAG8) rs160159557 SNP with ewe mature weight in four sheep breeds. These data provided the first production-relevant phenotypes, as well as the first organism-level (as opposed to cellular or tumor-derived) phenotypes, associated with TMEM8B, and in so doing, improved the annotation of this gene and genomic region by adding body weight implications. Once validated, these data can be applied in genetic or genomic selection aiming to achieve desired mature body weight.

Abstract

Signature of selection studies have identified many genomic regions with known functional importance and some without verified functional roles. Multiple studies have identified Transmembrane protein 8B (TMEM8B)rs426272889 as having been recently under extreme selection pressure in domesticated sheep, but no study has provided sheep phenotypic data clarifying a reason for extreme selection. We tested rs426272889 for production trait association in 770 U.S. Rambouillet, Targhee, Polypay, and Suffolk sheep. TMEM8Brs426272889 was associated with mature weight at 3 and 4 years (p < 0.05). This suggested selection for sheep growth and body size might explain the historical extreme selection pressure in this genomic region. We also tested Sperm-associated antigen 8 (SPAG8) rs160159557 encoding a G493C substitution. While this variant was associated with mature weights at ages 3 and 4, it was not as strongly associated as TMEM8Brs426272889. Transmembrane protein 8B has little functional information except as an inhibitor of cancer cell proliferation. To our knowledge, this is the first study linking TMEM8B to whole organism growth and body size under standard conditions. Additional work will be necessary to identify the underlying functional variant(s). Once identified, such variants could be used to improve sheep production through selective breeding.

Effects of propofol on human cholangiocarcinoma and the associated mechanisms

Cholangiocarcinoma (CCA) is the most common type of biliary duct malignancy. Propofol is a fast-acting intravenous anesthetic, which also exerts an anti-cancer effect. The aim of the current study was to explore the effects of propofol on human CCA and the associated mechanisms in vitro. The results indicated that as concentration (0, 1, 5 and 10 µg/ml) of propofol and treatment time (24, 48 and 72 h) increased, the cell inhibition rate of human CCA QBC939 cells increased. Furthermore, treatment with various concentrations of propofol for 48 h resulted in a decrease in migration and invasion capacity in QBC939 cells. Propofol also induced the apoptosis of QBC939 cells and cell cycle arrest in G1 phase. Propofol treatment increased the expression level of Bax and decreased that of Bcl-2. In addition, the effects of propofol on gene expression were evaluated, including Wnt3α, β-catenin, Snail1 and c-myc in the Wnt/β-catenin signaling pathway. It was identified that as the concentration of propofol increased, the expression of these genes decreased. In conclusion, the current results indicate that propofol is a promising therapeutic agent for the treatment of CCA.

Cordyceps militaris fraction inhibits the invasion and metastasis of lung cancer cells through the protein kinase B/glycogen synthase kinase 3β/β-catenin signaling pathway

Cordyceps militaris is widely used as a traditional Chinese medicine health supplement, and is also used in the development of anticancer agents. In our previous studies, it was revealed that C. militaris fraction (CMF) possessed an antitumor effect against K562 cells in vitro, induced apoptosis and caused cell cycle arrest in the S phase. The published results also demonstrated that CMF-induced apoptosis was involved in mitochondrial dysfunction. The aim of the present study was to investigate the anti-invasion and anti-metastasis effects of CMF in NCI-H1299 and Lewis lung cancer (LLC) cell lines, which have high metastatic potential. MTT and clone formation assays were initially used to investigate the inhibitory effect of CMF on the viability of NCI-H1299 and LLC cells. The results of cell adhesion, wound healing, migration and Matrigel invasion assays in vitro indicated that NCI-H1299 cells (treated with 1, 3, 10 or 30 µg/ml CMF) and LLC cells (treated with 0.1, 0.3, 1 or 3 µg/ml CMF) demonstrated a concentration-dependent reduction in cell migration and invasion compared with the control. In vivo experiments demonstrated that the oral administration of CMF (65, 130 or 260 mg/kg) decreased the tumor growth and decreased the lung and liver metastasis in an LLC xenograft model, compared with untreated mice. Furthermore, western blot analysis was used to investigate the mechanism of the effect of CMF on the migration of NCI-H1299 cells and metastasis in the xenograft model. The results revealed that CMF may promote glycogen synthase kinase 3β (GSK-3β)-mediated degradation of β-catenin inhibited the phosphorylation of upstream protein kinase B (Akt), which resulted in the attenuation of the expression of matrix metalloproteinase (MMP)-2 and MMP-9. These results suggested that CMF may possess potential for the treatment of lung cancer metastasis via the Akt/GSK-3β/β-catenin pathway.

EZH2 inhibition promotes methyl jasmonate-induced apoptosis of human colorectal cancer through the Wnt/β-catenin pathway

Methyl jasmonate potentially induces the differentiation of human myeloid leukemia cells and inhibits their proliferation; it may induce the differentiation and apoptosis of human lymphocytic leukemia cells, but does not exert a damaging effect on normal lymphocytes. In the present study, the anticancer effect of methyl jasmonate on human colorectal cancer cells was investigated. Cell viability and apoptosis was assessed using a Cell Counting kit-8 assay and flow cytometry, respectively. Methyl jasmonate suppressed cell viability and induced apoptosis in human colorectal cancer cells. Additionally, methyl jasmonate increased the activation of caspase-3, inhibited the expression levels of enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) and the Wnt/β-catenin pathway in human colorectal cancer. Downregulation of EZH2 expression enhanced the anticancer effect of methyl jasmonate on human colorectal cancer cells through suppression of the Wnt/β-catenin pathway. Thus, EZH2 downregulation promotes the anticancer effect of methyl jasmonate by inducing apoptosis in human colorectal cancer cells through the Wnt/β-catenin pathway.

Propofol inhibits proliferation, migration, and invasion but promotes apoptosis by regulation of Sox4 in endometrial cancer cells

Propofol is an intravenous sedative hypnotic agent of which the growth-inhibitory effect has been reported on various cancers. However, the roles of propofol in endometrial cancer (EC) remain unclear. This study aimed to explore the effects of propofol on EC in vitro and in vivo. Different concentrations of propofol were used to treat Ishikawa cells. Colony number, cell viability, cell cycle, apoptosis, migration, and invasion were analyzed by colony formation, MTT, flow cytometry, and Transwell assays. In addition, the pcDNA3.1-Sox4 and Sox4 siRNA plasmids were transfected into Ishikawa cells to explore the relationship between propofol and Sox4 in EC cell proliferation. Tumor weight in vivo was measured by xenograft tumor model assay. Protein levels of cell cycle-related factors, apoptosis-related factors, matrix metalloproteinases 9 (MMP9), matrix metalloproteinases 2 (MMP2) and Wnt/β-catenin pathway were examined by western blot. Results showed that propofol significantly decreased colony numbers, inhibited cell viability, migration, and invasion but promoted apoptosis in a dose-dependent manner in Ishikawa cells. Moreover, propofol reduced the expression of Sox4 in a dose-dependent manner. Additionally, propofol significantly suppressed the proportions of Ki67⁺ cells, but Sox4 overexpression reversed the results. Furthermore, in vivo assay results showed that propofol inhibited tumor growth; however, the inhibitory effect was abolished by Sox4 overexpression. Moreover, propofol inhibited Sox4 expression via inactivation of Wnt/β-catenin signal pathway. Our study demonstrated that propofol inhibited cell proliferation, migration, and invasion but promoted apoptosis by regulation of Sox4 in EC cells. These findings might indicate a novel treatment strategy for EC.

Wnt signaling as potential therapeutic target in lung cancer

INTRODUCTION

Wingless-type (Wnt) signaling is tightly regulated at multiple cellular levels and is dysregulated in lung cancer. Therefore, it offers therapeutic targets for developing novel agents for lung cancer treatment.

AREAS COVERED

In this article, we discuss the role of the Wnt signaling pathway in lung cancer, highlighting the aberrant activation of Wnt in lung cancer stem cells and its implication in resistance to radiotherapy, chemotherapy and targeted therapy. We also expound the regulatory roles of microRNAs in Wnt signaling, as well as the potential of the Wnt pathway to provide biomarkers and therapeutic targets in lung cancer. The potential use of small molecule and biological inhibitors targeting the Wnt pathway for lung cancer therapy and prevention is also discussed.

EXPERT OPINION

Wnt signaling plays an important role in the development and metastasis of lung cancer; the pathway provides targets to develop agents towards for cancer prevention and therapy. A number of clinical trials have shown the effectiveness of Wnt pathway inhibitors in epithelial tumors. However, the side effects should be considered. Nevertheless, the results from clinical studies suggest that inhibitors targeting the Wnt signaling show promise against lung cancer.

Tumor suppressor NGX6 inhibits the growth and metastasis of multiple cancers

Nasopharyngeal carcinoma-associated gene 6 (NGX6) is a membrane protein primarily located in the nuclear membrane and cell membrane. Several groups reported that NGX6 gene was down-regulated in nasopharyngeal carcinoma (NPC), gastric cancer, lung cancer, liver cancer, and colorectal cancer and even less in the carcinomas with metastasis. Current studies have demonstrated that NGX6 possesses various biological functions, such as regulating protein expression of related genes, involving cell signal transduction pathways, negatively controlling cell cycle progression, inhibiting angiogenesis, and increasing the sensitivity of patients to anti-cancer drugs. Some factors regulating the expression level of NGX6 gene also have been studied. The methylation of promoter of NGX6 and histone H3K9 negatively regulates its expression, similar to the function of transcription factor special protein-1 (Sp1). However, the regulatory factor early growth response gene 1 (Egr-1) is provided with positive regulation function. This review will summarize the progress of those studies on NGX6 and elucidate the potential application of NGX6 for some malignant diseases.

Correlation of NGX6 expression with clinicopathologic features and prognosis in colon cancer

OBJECTIVE

The aim was to explore the correlation of NGX6 expression with clinicopathological features and prognosis in colon cancer.

METHODS

Clinicopathological feature of 145 patients with colon cancer were analyzed.NGX6 expression was measured using immunohistochemistry methods. The correlation of NGX6 expression with clinicopathological features and prognosis were assessed.

RESULTS

Among 145 cases of colon cancer, NGX6 positive expression were found in 76 (52.4%) cases and NGX6 negative expression were found in 69 (47.6%) cases. The expression of NGX6 was closely associated with size tumor, lymph node metastasis and TNM stage (P=0.002, 0.012, and 0.039, respectively). Kaplan-Meier analysis showed that NGX6 negative expression was associated with shorter disease-free survival (DFS) (P=0.029) and overall survival (OS) (P=0.015). Multivariate survival analysis demonstrated that NGX6 expression was the important independent prognostic factor for colon cancer (P=0.022).

CONCLUSION

NGX6 is involved in the invasion and metastasis activity of colon cancer. NGX6 could may be applied as a novel and promising prognostic marker for colon cancer.

NGX6a is degraded through a proteasome-dependent pathway without ubiquitination mediated by ezrin, a cytoskeleton-membrane linker

Our previous study demonstrated that the NGX6b gene acts as a suppressor in the invasion and migration of nasopharyngeal carcinoma (NPC). Recently, we identified the novel isoform NGX6a, which is longer than NGX6b. In this study, we first found that NGX6a was degraded in NPC cells and that this degradation was mediated by ezrin, a linker between membrane proteins and the cytoskeleton. Specific siRNAs against ezrin increase the protein level of NGX6a in these cells. During degradation, NGX6a is not ubiquitinated but is degraded through a proteasome-dependent pathway. The distribution pattern of ezrin was negatively associated with NGX6a in an immunochemistry analysis of a nasopharyngeal carcinoma tissue microarray and fetus multiple organ tissues and Western blot analysis in nasopharyngeal and NPC cell lines, suggesting that ezrin and NGX6a are associated and are involved in the progression and invasion of NPC. By mapping the interacting binding sites, the seven-transmembrane domain of NGX6a was found to be the critical region for the degradation of NGX6a, and the amino terminus of ezrin is required for the induction of NGX6a degradation. The knockdown of ezrin or transfection of the NGX6a mutant CO, which has an EGF-like domain and a transmembrane 1 domain, resulted in no degradation, significantly reducing the ability of invasion and migration of NPC cells. This study provides a novel molecular mechanism for the low expression of NGX6a in NPC cells and an important molecular event in the process of invasion and metastasis of nasopharyngeal carcinoma cells.

MicroRNA-93 suppress colorectal cancer development via Wnt/β-catenin pathway downregulating

MicroRNA-93 (miR-93) is involved in several carcinoma progressions. It has been reported that miR-93 acts as a promoter or suppressor in different tumors. However, till now, the role of miR-93 in colon cancer is unclear. Herein, we have found that expression of miR-93 was lower in human colon cancer tissue and colorectal carcinoma cell lines compared with normal colon mucosa. Forced expression of miR-93 in colon cancer cells inhibits colon cancer invasion, migration, and proliferation. Furthermore, miR-93 may downregulate the Wnt/β-catenin pathway, which was confirmed by measuring the expression level of the β-catenin, axin, c-Myc, and cyclin-D1 in this pathway. Mothers against decapentaplegic homolog 7 (Smad7), as an essential molecular protein for nuclear accumulation of β-catenin in the canonical Wnt signaling pathway, is predicted as a putative target gene of miR-93 by the silico method and demonstrated that it may be suppressed by targeting its 3'UTR. These findings showed that miR-93 suppresses colorectal cancer development via downregulating Wnt/β-catenin, at least in part, by targeting Smad7. This study revealed that miR-93 is an important negative regulator in colon cancer and suggested that miR-93 may serve as a novel therapeutic agent that offers benefits for colon cancer treatment.

DNA promoter and histone H3 methylation downregulate NGX6 in gastric cancer cells

Nasopharyngeal carcinoma-associated gene 6 (NGX6) is a novel candidate tumor metastasis suppressor gene. Our study was to determine whether DNA hypermethylation and histone modification at the NGX6 gene promoter play important roles in silencing NGX6 expression in gastric cancer. NGX6 expression was downregulated in all gastric cancer cells and 76.19 % tissues. In three GC cell lines, hypermethylated NGX6 loci were characterized by histone H3-K9 hypoacetylation and hypermethylation. Trichostatin A treatment could moderately increase H3-K9 acetylation at the silenced loci; however, it had no effect on DNA and H3-K9 methylation and minimal effects on NGX6 expression. In contrast, 5'aza-2'-deoxycytidine treatment could rapidly decrease DNA and H3-K9 methylation at the silenced loci, leading to the reexpression of NGX6. Combined treatment with 5'aza-2'-deoxycytidine and trichostatin A had synergistic effects on the reexpression of NGX6 at the hypermethylation loci. Our current study shows that NGX6 expression is downregulated in GC cancer cells and tissues due to NGX6 promoter methylation and H3-K9 methylation, but not H3-K9 acetylation. Our findings indicate that the downregulation of NGX6 expression contributes to the development and progression of gastric cancer. More studies are needed to determine the precise mechanism of NGX6 in the progression of gastric cancer.

Resveratrol inhibits invasion and metastasis of colorectal cancer cells via MALAT1 mediated Wnt/β-catenin signal pathway

Resveratrol, extracted from Chinese herbal medicine Polygonum cuspidatum, is known to inhibit invasion and metastasis of human colorectal cancer (CRC), in which long non-coding Metastasis Associated Lung Adenocarcinoma Transcript 1 (RNA-MALAT1) also plays an important role. Using MALAT1 lentiviral shRNA and over-expression constructs in CRC derived cell lines, LoVo and HCT116, we demonstrated that the anti-tumor effects of resveratrol on CRC are through inhibiting Wnt/β-catenin signaling, thus the expression of its target genes such as c-Myc, MMP-7, as well as the expression of MALAT1. In detail, resveratrol down-regulates MALAT1, resulting in decreased nuclear localization of β-catenin thus attenuated Wnt/β-catenin signaling, which leads to the inhibition of CRC invasion and metastasis. This finding of ours surely provides important pre-clinical evidence supporting future use of resveratrol in prevention and treatment of CRC.

Tumor suppressor gene NGX6 induces changes in protein expression profiles in colon cancer HT-29 cells

Nasopharyngeal carcinoma-associated gene 6 (NGX6; syn. transmembrane protein 8B, TMEM8B) is a recently identified tumor suppressor gene. The underlying mechanisms by which the gene inhibits tumor development are not completely known. To further understand the function of the gene's protein product NGX6, in the present study, we employed two-dimensional difference gel electrophoresis to analyze the protein expression profiles of colon cancer HT-29 cells stably transfected with the gene NGX6. The differentially expressed proteins were selected and identified by matrix-assisted laser desorption/ionization coupled with time-of-flight tandem mass spectrometry. The results showed that 12 proteins were down-regulated and 4 were up-regulated in NGX6-transfected HT-29 cells, compared with vector-transfected HT-29 cells. The MS results were verified by western blot. Bioinformatic analysis showed that these proteins are involved in cell proliferation, metastasis, apoptosis, cytoskeletal structure, metabolism, and signal transduction, suggesting that NGX6 may inhibit colon cancer through the regulation of these biological processes.