Effect Of N-myc Downstream-regulated Gene 2 Research Articles

N-myc downstream regulated gene 2 ameliorates myocardial remodeling and cardiac function in heart failure rats.

This study aims to explore the effect of NDRG2 (N-myc downstream regulated gene 2)-mediated Transforming growth factor-beta 1 (TGF-β1)/ Sma- and Mad-related protein (Smad) pathway in heart failure (HF) rats. HF rat models were established and treated with AdEGFP (adenovirus encoding enhanced green fluorescent protein) or AdNDRG2 (adenovirus encoding NDRG2). The echocardiography and hemodynamic parameters were detected, and the infarct size was calculated via 2,3,5-triphenyltetrazolium chloride (TTC) staining. Masson staining was performed to observe the collagen volume fraction (CVF), quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) to detect the expression of Collagen I (Col-I) and Collagen III (Col-III), and Transferase (TdT)-mediated D-UTP-biotin nick end labeling (TUNEL) staining to evaluate the apoptosis. Rats in the Model group presented with the decreases in left ventricular ejection fraction (LVEF), left ventricular shortening fraction (LVFS), left ventricular systolic pressure (LVSP) and maximal/minimum rate of left ventricular pressure (±dp/dt max), and significant increases in left ventricular end-diastolic pressure (LVEDP) and CVF. At the meantime, the expression of Col-I and Col-III as well as the apoptotic rate of myocardial cells was also elevated with increased infarct size in the Model group. The Model rats also had the significant reduction in the expression of NDRG2 and up-regulations of TGF-β1, p-Smad2/Smad2, p-Smad3/Smad3 and tissue inhibitor of metalloproteinases-2 (TIMP-2). However, model rats treated with AdNDRG2 had evident amelioration in aforementioned indicators. In conclusion, NDRG2 reduces the apoptosis of myocardial cells and improves the heart function and myocardial remodeling in HF rats via inhibiting the activity of TGF-β1/Smad.

Overexpression of NDRG2 promotes the therapeutic effect of pazopanib on ovarian cancer

Objectives Ovarian cancer is the second commonly seen cancer in the US, patients with ovarian cancer are commonly diagnosed in the advanced stage. Pazopanib is an inhibitor of multiple tyrosine kinases and has been approved in treatment for carcinoma by FDA. N-myc downstream-regulated gene 2 (NDRG2) has been regarded as a cancer suppressor gene and presented an inhibition effect in cancer proliferation, invasion, and migration. Design: NDRG2 was overexpressed or inhibited in SKOV-3 cells, then experiments were performed to detect the apoptosis of cells. The expression or secretion of pro-cancer molecules was detected. And the expression of apoptosis-related proteins and the ASK1/JNK1 signaling pathway was detected. Methods The NDRG2 overexpression and inhibition model was firstly constructed in SKOV-3 cells, the apoptotic cells were detected using flow cytometry. The expression of cellular metastasis genes was detected using the qPCR method. The angiogenesis factors was detected using the ELISA method. Expression of each target protein was detected using western blotting analysis. Results NDRG2 overexpression and inhibition model were constructed in the SKOV-3 cell line, overexpression of NDRG2 enhanced the effect of pazopanib on inhibition of the expression of metastasis-related molecules and angiogenesis-related factors. The apoptosis process of cells was also enhanced after overexpression of NDRG2, and these effects were regulated by the activation of the ASK1/JNK1 signaling pathway. Limitations: The effect of NDRG2 in animal models and more cell lines needs to be explored in further study. Conclusions NDRG2 might be a therapeutic target in treatment for ovarian cancer.

NDRG2 gene expression pattern in ovarian cancer and its specific roles in inhibiting cancer cell proliferation and suppressing cancer cell apoptosis

BackgroundThe cancer cell metastasis and the acquisition of chemotherapy resistance remain huge challenge for ovarian cancer treatment. Previously, N-myc downstream-regulated gene 2 (NDRG2) serves as a tumor suppressor for many cancers. Here, we attempted to investigate the specific roles of NDRG2 in ovarian cancer.MethodsThe expression levels of NDRG2 were detected by qRT-PCR or Immunoblotting. CCK-8 assay was employed to examine the cell viability of ovarian cancer cells. The colony formation ability was determined by colony formation assay. Flow cytometry analyses were performed to detect the cell apoptosis and cell cycle. Xenograft tumor assay was performed to detect the in vivo function of NDRG2.ResultsWe revealed that NDRG2 mRNA expression and protein levels were downregulated within both ovarian cancer tissues and cell lines. The overexpression of NDRG2 dramatically inhibited the cell viability and colony formation and tumor growth, whereas promoted the cell apoptosis, cell cycle arrest in G1 phase within ovarian cancer cells. More importantly, NDRG2 overexpression significantly enhanced the suppressive roles of cisplatin (DDP) in ovarian cancer cell viability. On the contrary, NDRG2 silence exerted opposing effects on ovarian cancer cells.ConclusionsIn summary, we provide a solid experimental basis demonstrating the tumor-suppressive effects of NDRG2 in inhibiting the cell proliferation, enhancing the cell apoptosis, eliciting the cell cycle arrest in G1 phase, and promoting the suppressive effects of DDP on the viability of ovarian cancer cells. NDRG2 administration presents a potent adjuvant treatment for ovarian cancer therapy.

Abstract C123: Loss of tumor suppressor NDRG2 promotes cell proliferation and migration/invasion of oral squamous cell carcinoma cells

Abstract More than 90% of oral cancers are diagnosed as oral squamous cell carcinoma (OSCC). Although there has been much understanding of the molecular pathogenesis of OSCC, the majority of patients still die from local recurrence and metastasis of tumors. Recently, N-myc downstream-regulated gene 2 (NDRG2) has been known as a tumor suppressor gene in various types of malignancies, but its function and molecular mechanism in OSCC are very little known. To verify the functional roles of NDRG2 in OSCC, we screened six OSCC cell lines first using western blotting. Among the 6 cell lines, HN22 cell line showing high expression of NDRG2 was selected and treated with anti-NDRG2 small interfering RNA (siRNA). The effect of NDRG2 on cell proliferation was evaluated at 24h, 48h, and 72h after treatment of 50nM of anti-NDRG2 siRNA. In addition, in vitro migration and invasion assays were performed after same treatment. Western blot analysis showed variable levels of NDRG2 in 6 OSCC cell lines. Normal human oral keratinocyte as a positive control expressed very high level of NDRG2. Among 6 OSCC cell lines, three cell lines had very low level or absence of NDRG2, but remaining three cell lines including HN22 cell had moderate to high level of NDRG2. After 24h treatment of anti-NDRG2 siRNA on the HN22 cells, NDRG2 expression was significantly downregulated. In cell proliferation assay after treatment of 50nM of anti-NDRG2 siRNA, there was a significant increase in cell growth of HN22 cells when compared with the control (p=.005). In wound healing assay, NDRG2-downregulated HN22 cell line showed much more closure of wound area when compared with the control (p=.007). From the invasion assay after treatment, there was a significant increase in invasion ability of HN22 cells (p<.001). These date indicate that loss of function of NDRG2 as a tumor suppressor can enhance the cell growth, migration, and invasion of OSCC cells. Our results suggest that loss of NDRG2 expression plays a role in tumor progression of OSCC by enhancing tumor cell growth, motility, and invasiveness. Therefore, recovering loss of function of NDRG2 may be a new therapeutic strategy for OSCC treatment. Citation Format: Hye-Jung Yoon, Chi-Hyun Ahn, Ji-Hoon Kim. Loss of tumor suppressor NDRG2 promotes cell proliferation and migration/invasion of oral squamous cell carcinoma cells [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C123. doi:10.1158/1535-7163.TARG-19-C123

Ndrg2 deficiency ameliorates neurodegeneration in experimental autoimmune encephalomyelitis.

N-myc downstream-regulated gene 2 (NDRG2) is a differentiation- and stress-associated molecule that is predominantly expressed in astrocytes in the central nervous system. In this study, we examined the expression and role of NDRG2 in experimental autoimmune encephalomyelitis (EAE), which is an animal model of multiple sclerosis. Western blot and immunohistochemical analysis revealed that the expression of NDRG2 was observed in astrocytes of spinal cord, and was enhanced after EAE induction. A comparative analysis of wild-type and Ndrg2-/- mice revealed that deletion of Ndrg2 ameliorated the clinical symptoms of EAE. Although Ndrg2 deficiency only slightly affected the inflammatory response, based on the results of flow cytometry, qRT-PCR, and immunohistochemistry, it significantly reduced demyelination in the chronic phase, and, more importantly, neurodegeneration both in the acute and chronic phases. Further studies revealed that the expression of astrocytic glutamate transporters, including glutamate aspartate transporter (GLAST) and glutamate transporter 1, was more maintained in the Ndrg2-/- mice compared with wild-type mice after EAE induction. Consistent with these results, studies using cultured astrocytes revealed that Ndrg2 gene silencing increased the expression of GLAST, while NDRG2 over-expression decreased it without altering the expression of glial fibrillary acidic protein. The effect of NDRG2 on GLAST expression was associated with the activation of Akt, but not with the activation of nuclear factor-kappa B. These findings suggest that NDRG2 plays a key role in the pathology of EAE by modulating glutamate metabolism. Cover Image for this Issue: doi: 10.1111/jnc.14173.

Spatial-temporal expression of NDRG2 in brain tissues in a rat model of intracerebral hemorrhage: A pilot study.

N-myc downstream regulated gene 2 (NDRG2) was a member of the N-myc down regulated gene family which belongs to the alpha/beta hydrolase superfamily and played important roles in cell death. To date, the expression and effects of NDRG2 in brain after intracerebral hemorrhage (ICH) are unclear. In this study, we investigated the spatial-temporal expression of NDRG2 in brain tissues in a rat model of ICH. The expression levels of NDRG2 were tested in 3h, 6h, 12h, 24h, 48h, 72h, and 7d after ICH by western blot analysis. The results showed that the NDRG2 levels were increased and peaked at 24h after ICH, and then declined subsequently. Meanwhile, we also examined the NDRG2 cellular localization in brain tissues by immunofluorescence analysis with NeuN and GFAP (biomarker of neuron and astrocytes respectively). The results demonstrated that NDRG2 was mainly expressed in astrocytes, but not neurons, after ICH. Additionally, the results of double staining indicated that the rate of NDRG2- and TUNEL -positive cells was significantly higher in the brain tissues in rats after ICH. The roles of NDRG2 in ICH needed further investigation and inhibiting the expression of NDRG2 may have potential therapeutic effects in ICH.

N-myc downstream-regulated gene 2 expression is associated with glucose transport and correlated with prognosis in breast carcinoma

IntroductionN-myc downstream-regulated gene 2 (NDRG2), a novel tumour suppressor and cell stress-related gene, is involved in many cell metabolic processes, such as hormone, ion and fluid metabolism. We investigated whether NDRG2 is involved in any glucose-dependent energy metabolism, as well as the nature of its correlation with breast carcinoma.MethodsThe correlations between NDRG2 expression and glucose transporter 1 (GLUT1) expression in clinical breast carcinoma tissues were analysed. The effects of NDRG2 on glucose uptake were assessed in breast cancer cells and xenograft tumours. The consequences of NDRG2-induced regulation of GLUT1 at the transcription and translation levels and the interaction between NDRG2 and GLUT1 were examined.ResultsData derived from clinical breast carcinoma specimens revealed that (1) patients with high NDRG2 expression had better disease-free survival and overall survival than those with low NDRG2 expression and (2) NDRG2 expression was negatively correlated with GLUT1 expression in these breast carcinoma tissues. NDRG2 inhibited glucose uptake by promoting GLUT1 protein degradation without affecting GLUT1 transcription in both breast cancer cells and xenograft tumours. In addition, NDRG2 protein interacted and partly colocalised with GLUT1 protein in cell cytoplasm areas.ConclusionsThe results of our study support the notion that NDRG2 plays an important role in tumour glucose metabolism, in which GLUT1 is a likely candidate contributor to glucose uptake suppression and tumour growth. Targeting the actions of NDRG2 in cell glucose-dependent energy delivery may provide an attractive strategy for therapeutic intervention in human breast carcinoma.