N-myc downstream regulated gene 1 inhibition of tumor progression in Caco2 cells

BACKGROUND Invasion and migration are the irreversible stages of colorectal cancer(CRC).The key is to find a sensitive,reliable molecular marker that can predict the migration of CRC at an early stage.N-myc downstream regulated gene 1(NDRG1)is a multifunctional gene that has been tentatively reported to have a strong relationship with tumor invasion and migration,however the current molecular role of NDRG1 in CRC remains unknown.AIM To explore the role of NDRG1 in the development of CRC.METHODS NDRG1 stably over-expressed Caco2 cell line was established by lentiviral infection and NDRG1 knock-out Caco2 cell line was established by CRISPR/Cas9.Furthermore,the mRNA and protein levels of NDRG1 in Caco2 cells after NDRG1 over-expression and knockout were detected by real-time polymerase chain reaction and western blot.The cell proliferation rate was measured by the cell counting kit-8 method;cell cycle and apoptosis were detected by flow cytometry;invasion and migration ability were detected by the 24-transwell method.RESULTS NDRG1 over-expression inhibited Caco2 proliferation and the cell cycle could be arrested at the G1/S phase when NDRG1 was over-expressed,while the number of cells in the G2 phase was significantly increased when NDRG1 was knocked out.This suggests that NDRG1 inhibited the proliferation of Caco2 cells by arresting the cell cycle in the G1/S phase.Our data also demonstrated that NDRG1 promotes early cell apoptosis.Invasion and migration of cells were extensively inhibited when NDRG1 was over-expressed.CONCLUSION NDRG1 inhibits tumor progression in Caco2 cells which may represent a potential novel therapeutic strategy for the treatment of CRC.

Regulation of HIF-1 α to Expression of N-myc Downstream Regulated Gene 1 in Colorectal Carcinoma

Plasmid expressing small interfering RNA （siRNA） against HIF-1α （pSilence-2.1-U6-siRNA） was constructed and transfected into LS174T cells in hypoxia condition.After expression of siRNA against HIF-1 α in LS174T cells, expressions of HIF-1 α and N-myc downstream regulated gene 1 （NDRG1） gene were inhibited significantly. HIF-1 cta transcripts were positive in 67.7% （42/62） and 44.4% （8/18） of colorectal adenocarcinoma and adenoma, re- spectively. The mean percentage of cells with positive hybridization of HIF-1 α mRNA increases with the development from Duke stage A to stage C＋D （p〈 0.05）. The positive staining rate of NDRG1 protein was significant higher in than that in colorectal adenoma colorectal adenocarcinoma group group （p〈 0.05）. The level of HIF-1 a transcripts was positively correlated with the level of NDRG1 protein （p 〈 0.05） during colorectal tumor progression. HIF-1α and its down stream gene NDRG1 may play roles in tumor progression of human colorectal carcinoma.

卵巢癌组织中LSD1、NDRG1基因表达量与癌细胞迁移、侵袭的相关性研究

目的:研究卵巢癌组织中赖氨酸特异性组蛋白去甲基化酶1(lysine-specific demethylase 1,LSD1)、N-myc下游调节基因1(N-myc downstream regulated 1,NDRG1)基因表达量与癌细胞迁移、侵袭的相关性。方法:选择2014年3月~2017年7月扶风县人民医院接受手术切除的卵巢癌患者作为研究对象,手术切除后取卵巢癌组织和癌旁组织,测定LSD1、NDRG1基因及迁移基因、侵袭基因的表达量。结果:卵巢癌组织中LSD1、YKL40、COX2、Twist、IFITM1、CatL、CTHRC1、MMP2、FUNDC1基因的mRNA表达量显著高于癌旁组织,NDRG1、E-cadherin、Wnt5a基因的mRNA表达量显著低于癌旁组织;LSD1高表达的卵巢癌组织中YKL40、COX2、Twist、IFITM1、CatL、CTHRC1、MMP2、FUNDC1的mRNA表达量显著高于LSD1低表达的卵巢癌组织,E-cadherin、Wnt5a基因的mRNA表达量显著低于LSD1低表达的卵巢癌组织。结论:卵巢癌组织中LSD1高表达、NDRG1低表达能够促进癌细胞的迁移、侵袭。

Correlation of LSD1 and NDRG1 gene expression in ovarian cancer tissue with cancer cell migration and invasion

Objective: To study the correlation of LSD1 and NDRG1 gene expression in ovarian cancer tissue with cancer cell migration and invasion. Methods: Patients with ovarian cancer who underwent surgical resection in Fufeng County People's Hospital between March 2014 and July 2017 were selected as the research subjects, and the ovarian cancer tissue and adjacent tissue were collected after surgical resection to determine the expression of LSD1, NDRG1, migration genes and invasion genes. Results: LSD1, YKL40, COX2, Twist, IFITM1, CatL, CTHRC1, MMP2 and FUNDC1 mRNA expression in ovarian cancer tissue were significantly higher than those in adjacent tissue whereas NDRG1, E-cadherin and Wnt5a mRNA expression were significantly lower than those in adjacent tissue;YKL40, COX2, Twist, IFITM1, CatL, CTHRC1, MMP2 and FUNDC1 mRNA expression in ovarian cancer tissue with high LSD1 expression were significantly higher than those in ovarian tissue with low LSD1 expression whereas E-cadherin and Wnt5a gene mRNA expression were significantly lower than those in ovarian tissue with low LSD1 expression. Conclusion: The high LSD1 expression and low NDRG1 expression in ovarian cancer tissue can promote the migration and invasion of cancer cells.

d-limonene prevents ultraviolet irradiation:Induced cyclobutane pyrimidine dimers in Skh1 mouse skin

AIM: To establish whether d-limonene can protect against induction of cyclobutane pyrimidine dimers(CPDs) and sunburn in ultraviolet irradiation(UVR) irradiated mouse skin. METHODS: The d-limonene was given in 4 daily oral 20 μL aliquots at different concentrations as follows: 100%, 10% or 1% in liponate and 100% liponate as control. One day after the final d-limonene treatment, the mice were anesthetized with i.p. sodium pentobarbital and placed in boxes to allow a rectangular(2 cm × 4 cm) region of dorsal skin to be irradiated with a single, ultraviolet radiation dose of 1.5 kJ /m2. Skin samples from UVR irradiated area were obtained at 5 min after UVR exposure for CPD detection, at 6 d after UVR exposure, skin samples were obtained for in situ analysis for N-myc downstream regulating gene 1(NDRG1)(a stress response gene), proliferating cell nuclear antigen(PCNA)(an S-phase marker) and filaggrin(a barrier integrity gene). Based on immunohistochemistry staining, the number of CPD, NDRG1 and PCNA positive cells, as well as unstained cells was counted in 3 different individually selected areas and percentage of positive cells was established. RESULTS: CPD reduction occurred as follows: liponate only-none; 1% d-limonene-54.3% reduction of CPDs; 10% d-limonene-73.4% reduction of CPDs; 100% d-limonene-86.1% reduction of CPDs, the latter equivalent to a UV dose of only 0.21 k J/m2. Sunburn was also dose-dependently reduced by d-limonene. The NDRG1 protein was strongly induced by UVR(70.0% ± 10.4% positive cells), but 1% d-limonene reduced the response to 64.6% ± 9.2%, 10% d-limonene reduced the response to 16.2% ± 3.4% and 100% d-limonene reduced the response to 6.3% ± 1.7%. Similarly, PCNA was 52.4% ± 9.9% positive in UVR exposed skin, and 1% d-limonene reduced it to 42.9% ± 8.1%, 10% d-limonene reduced it to 36.2% ± 6.7% and 100% d-limonene reduce it to 13.8% ± 3.4%. NDRG1 and PCNA were increased by d-limonene or UVR separately, but combined they produced less than either agent separately owing to the protective effect of pre-exposure to d-limonene. CONCLUSION: Overall d-limonene acted to protect against ultraviolet B-induced DNA photodamage and sunburn in UVR exposed skin.

NDRG2在中枢神经系统疾病中的研究进展

NDRG家族（N-myc downstream regulated gene family）是近年来新发现的基因家族,该基因家族成员NDRG1首先作为N-myc突变小鼠胚胎中的一个上调基因被克隆和命名,目前已克隆的人源NDRG基因包括NDRG1、NDRG2、NDRG3和NDRG4。一系列的研究表明,NDRG2是一种与细胞增殖和分化相关的基因,参与细胞的增殖分化和应激反应,但其在神经系统疾病中的功能尚未完全明确。本文就其在中枢神经系统疾病中的研究现状作以回顾。

NDRG2磷酸化对星形胶质细胞存活的影响

目的:研究星形胶质细胞CTX TNA2在氧糖剥夺(oxygen-glucose deprivation,OGD)后N-myc downstream regulated gene 2(NDRG2)和其磷酸化分子p-NDRG2(Thr-348)的表达变化,明确NDRG2的磷酸化修饰是否对星形胶质细胞存活产生影响。方法:将CTX TNA2细胞进行3 h OGD处理,复氧复糖后于0 h,2 h,6 h,12 h,24 h,通过Western Blot检测NDRG2和p-NDRG2(Thr-348)水平的变化。再通过感染慢病毒或给予Akt改变pNDRG2(Thr-348),研究不同水平的p-NDRG2(Thr-348)对CTX TNA2细胞的存活是否产生影响。结果:(1)CTX TNA2细胞在OGD后2 h NDRG2(Thr-348)磷酸化水平达到峰值,以后逐渐下降,24 h后会恢复到OGD后0 h的水平;(2)抑制p-NDRG2(Thr-348),降低CTX TNA2细胞活力(P<0.05),增加乳酸脱氢酶(lactate dehydrogenase,LDH)释放(P<0.05);(3)促进p-NDRG2(Thr-348),提高CTX TNA2细胞活力(P<0.05),减少LDH释放(P<0.05);结论:星形胶质细胞CTX TNA2细胞在OGD后NDRG2磷酸化水平发生明显变化。促进NDRG2磷酸化,有助于细胞存活;抑制NDRG2磷酸化,加重细胞凋亡。

NDRG1 promotes endothelial dysfunction and hypoxia-induced pulmonary hypertension by targeting TAF15

Background:Pulmonary hypertension(PH)represents a threatening pathophysiologic state that can be induced by chronic hypoxia and is characterized by extensive vascular remodeling.However,the mechanism underlying hypoxia-induced vascular remodeling is not fully elucidated.Methods and Results:By using quantitative polymerase chain reactions,western blotting,and immunohistochemistry,we demon-strate that the expression of N-myc downstream regulated gene-1(NDRG1)is markedly increased in hypoxia-stimulated endothelial cells in a time-dependent manner as well as in human and rat endothelium lesions.To determine the role of NDRG1 in endothelial dysfunction,we performed loss-of-function studies using NDRG1 short hairpin RNAs and NDRG1 over-expression plasmids.In vitro,silencing NDRG1 attenuated proliferation,migration,and tube formation of human pulmonary artery endothelial cells(HPAECs)un-der hypoxia,while NDRG1 over-expression promoted these behaviors of HPAECs.Mechanistically,NDRG1 can directly interact with TATA-box binding protein associated factor 15(TAF15)and promote its nuclear localization.Knockdown of TAF15 abrogated the effect of NDRG1 on the proliferation,migration and tube formation capacity of HPAECs.Bioinformatics studies found that TAF15 was involved in regulating PI3K-Akt,p53,and hypoxia-inducible factor 1(HIF-1)signaling pathways,which have been proved to be PH-related pathways.In addition,vascular remodeling and right ventricular hypertrophy induced by hypoxia were markedly alleviated in NDRG1 knock-down rats compared with their wild-type littermates.Conclusions:Taken together,our results indicate that hypoxia-induced upregulation of NDRG1 contributes to endothelial dysfunction through targeting TAF15,which ultimately contributes to the development of hypoxia-induced PH.

非小细胞肺癌中NDRG1与HIF-1α表达模式及相关性的研究

目的探讨非小细胞肺癌组织中NDRG1(N-myc下游调节因子1)与HIF-1α(缺氧诱导因子1α)的表达模式及关联。方法应用免疫组织化学方法检测105例非小细胞肺癌及癌旁肺组织中NDRG1和HIF-1α的蛋白表达。应用Western Blotting检测12对新鲜肺癌组织及癌旁肺组织中NDRG1及HIF-1α的蛋白表达。结果 NDRG1与HIF-1α在非小细胞肺癌组织中具有相似的表达模式,均主要表达于细胞浆,阳性率分别为55.2%(58/105)及50.5%(53/105),部分病例伴有细胞核(分别为20.0%(21/105)及35.2%(37/105))和细胞膜(分别为11.4%(12/105)及7.6%(8/105))的表达,总的阳性率分别为60.0%(63/105)及53.3%(56/105)。NDRG1在癌旁肺组织中的表达(17.1%(18/105))低于癌组织(<0.05),HIF-1α在癌旁肺组织中的表达(46.7%(49/105))与癌组织中的表达无显著差异(>0.05),NDRG1与HIF-1α在非小细胞肺癌组织中的表达水平呈正相关(r=0.210,<0.05)。Western Blotting结果显示NDRG1在肺癌组织中的表达高于癌旁肺组织(<0.05),其在癌组织中的表达与HIF-1α的蛋白表达呈正相关(<0.05)。HIF-1α在癌及癌旁组织中的表达无明显差异(<0.05)。结论 NDRG1在非小细胞肺癌高表达与HIF-1α表达呈正相关,二者可能在肿瘤内部缺氧诱导的应激反应过程中存在相互作用。