Mutaciones del gen NOTCH1 en la leucemia linfocítica crónica / NOTCH1 gene mutations in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world. The disease has\r\na highly variable clinical course, ranging from very indolent cases to patients with aggressive and rapidly\r\nprogressing outcome. Genetic studies are useful tools in analyzing this pathology, and have been incorporated in international risk classifications. The analysis of genomic rearrangements and the mutational status of immunoglobulin heavy chain variable have allowed risk groups of high prognostic value to be established. More recently, next generation sequencing studies have identified novel somatic mutations that could explain the wide clinical variability of this pathology. Among them, the analysis of NOTCH1 (neurogenic locus notch homolog protein 1) gene mutations are of interest, as deregulation is associated with tumorigenesis. NOTCH11 mutations are mostly located at exon 34 (80% of cases) and 3´UTR (untranslated region). They produce premature stop codons that produce a constitutively active and stable NOTCH1 protein. NOTCH1 mutations are associated with adverse prognosis and refractoriness to treatment. The aim of this study was to analyze NOTCH1 mutations in CLL patients by ASO-PCR and sequencing. Our results found 4.4% of cases with NOTCH1 mutated values concordant with international observations (5%-10%). Including them in the genetic status of CLL patients allows the characterization of risk groups, an aspect of great importance in clinical practice and therapeutic decisions, to be refined.

La leucemia linfocítica crónica (LLC) es la leucemia más frecuente en adultos de Occidente. Presenta\r\nun curso clínico altamente variable, con pacientes que requieren tratamiento inmediato y otros con un curso indolente de la enfermedad. Los estudios genéticos constituyen herramientas de suma utilidad en esta enfermedad, encontrándose incorporados a las clasificaciones de riesgo internacionales. El análisis de los rearreglos genómicos y del estado mutacional de los genes IGHV (immunoglobulin heavy chain variable region) ha hecho factible establecer grupos de riesgo de alto valor pronóstico. Más recientemente, estudios de secuenciación de última generación permitieron la detección de mutaciones\r\nsomáticas previamente desconocidas en esta afección, que podrían explicar la amplia variabilidad clínica\r\nobservada en la LLC. Entre ellas, resultan de interés las observadas en el gen NOTCH1 (neurogenic locus notch homolog protein 1), cuya desregulación se asocia con el desarrollo tumoral. Estas mutaciones se acumulan en mayor medida en el exón 34 (80% de los casos) y en la región 3´UTR (untraslated region), lo que genera codones de terminación prematuros que originan una proteína NOTCH1 constitutivamente activa y más estable, los cuales se asocian con pronóstico adverso y refractariedad al tratamiento. Nuestro objetivo fue evaluar mutaciones de NOTCH1 en nuestros pacientes mediante ASO-PCR y secuenciación. Se detectaron mutaciones en el 4.4% de los casos, valor concordante con los datos internacionales (5% a 10%). Su inclusión en la caracterización genética de los pacientes con LLC permitirá refinar la categorización de los grupos de riesgo, aspecto de suma importancia tanto en el seguimiento clínico como en la toma de decisiones terapéuticas.

Targeted inhibition of Notch1 gene enhances the killing effects of paclitaxel on triple negative breast cancer cells

Objective To study the influence of targeted inhibition of Notch1 gene on the killing effects of paclitaxel on triple negative breast cancer cells. Methods The triple negative [estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor 2 (Her2)] breast cancer cell line MDA-MB-231 and ER/PR/HER-2-positive breast cancer cell line MCF-7 were cultured, transfected with Notch1-siRNA-overexpression plasmid and blank plasmid, and treated with different concentrations of paclitaxel, and then the cell proliferation activity and apoptosis rate as well as the mRNA expression of Caspase-3, Caspase-9 and Bcl-2 were determined. Results Paclitaxel could decrease the MDA-MB-231 and MCF-7 cell proliferation activity as well as Bcl-2 mRNA expression, and increase MDA-MB-231 and MCF-7 cell apoptosis rate as well as Caspase-3 and Caspase-9 mRNA expression in dose-dependent manners; with the same dose of paclitaxel treatment, the inhibitory effects on MDA-MB-231 cell proliferation activity and Bcl-2 mRNA expression as well as the promoting effects on MDA-MB-231 cell apoptosis and mRNA expression of Caspase-3 and Caspase-9 were weaker than those on MCF-7 cell; after 0.5 μM paclitaxel combined with Notch1-siRNA treatment, MDA-MB-231 cell proliferation activity and Bcl-2 mRNA expression were significantly lower than those after 0.5 μM paclitaxel combined with control plasmid treatment while cell apoptosis rate and mRNA expression of Caspase-3 and Caspase-9 were higher than those after 0.5 μM paclitaxel combined with control plasmid treatment. Conclusions Targeted inhibition of Notch1 gene may enhance the killing effects of paclitaxel on triple negative breast cancer cells by up-regulating the expression of Caspase-3 and Caspase-9 and inhibiting the expression of Bcl-2.

Analysis of variants located in 3'UTR regions of NOTCH1 and JAG1 genes for children with conotruncal heart defects / 上海交通大学学报（医学版）

Objective · To explore the correlation between variants located in 3' untranslated regions (3'UTR) of NOTCH1 and JAG1 genes and conotruncal heart defects (CTD). Methods · Six hundred CTD children without 22q11 deletion and three hundred healthy children were enrolled in this hospital-based case-control study. Variants located in the 3'UTR regions of NOTCH1 and JAG1 genes were detected by high-throughput sequencing. The accuracy of the variants were verified by PCR and Sanger sequencing. Online software PicTar, TargetScan and microRNA.org were used to make functional predictions. Results · One mutation and three SNPs were found in the 3'UTR of NOTCH1. Three mutations and six SNPs were found in the 3'UTR of JAG1. The genotypic distributions of two SNPs (rs3840074 and rs8708) located in JAG13'UTR between CTD group and the controls were statistically significant (both P<0.05). Results of prediction showed that all the four mutations and two meaningful SNPs could bind to microRNA. Conclusion · The variants located in 3'UTR regions of NOTCH1 and JAG1 genes may be related to the occurrence of CTD.

Effect of silencing Notch1 gene on proliferation, apoptosis and Akt/mTOR pathyway inhibition in clear cell renal cell carcinoma / 中华泌尿外科杂志

Objective To investigate the effect of silencing Notch1 gene by RNA interference on the proliferation,apoptosis and Akt/mTOR signaling pathway in clear renal cell carcinoma.Methods The optimal segment targeting Notch1 gene was designed and transfected into 786-O cells by Lipofectamine TM2000.The Notch1 mRNA and protein were detected by RT-PCR and Western blot.The proliferation rate of 786-O cells was evaluated by MTT and the variation of apoptosis was measured by TUNEL.The protein expression level of apoptosis-related protein Bcl-2,caspase-3,caspase-9,and signaling pathway protein Akt,p-Akt,p-mTOR,p-P70S6K were detected by Western blott.Results Notchl mRNA and protein was markedly suppressed by the siRNA targeting Notch1.Treated with 0,40,60,80,100 and 120 nmol/L of Notch1 siRNA for 24 hours,cell proliferation rates were (98.51 ± 1.33) ％,(87.34 ± 2.26) ％,(64.72 ± 3.24)％,(57.68 ±3.32)％,(31.91 ± 1.85)％ and (19.27 ±2.73)％,and the difference was statistically significant (P ＜ 0.01).Treated with 0,40,80,and 120 nmol/L of Notchl siRNA for 24 hours,apoptosis rates were (7.6 ± 3.8) ％,(21.5 ± 4.8) ％,(32.3 ± 3.5) ％,and (46.3 ± 4.7％),the difference was statistically significant (P ＜ 0.05).Decreased expression of Akt signaling pathway proteins p-Akt,p-mTOR,p-70S6K and apoptosis-related protein Bcl-2,procaspase-3 was detected,but no change in the total protein of Akt.Conclusions Depletion of Notch1 gene could inhibit cell growth and induce apoptosis in 786-O cell line.It inhibits Akt/mTOR signaling pathway by dephosphorylated.

Targeted inhibition of Notch1 gene enhances the killing effects of paclitaxel on triple negative breast cancer cells

OBJECTIVE@#To study the influence of targeted inhibition of Notch1 gene on the killing effects of paclitaxel on triple negative breast cancer cells.@*METHODS@#The triple negative [estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor 2 (Her2)] breast cancer cell line MDA-MB-231 and ER/PR/HER-2-positive breast cancer cell line MCF-7 were cultured, transfected with Notch1-siRNA-overexpression plasmid and blank plasmid, and treated with different concentrations of paclitaxel, and then the cell proliferation activity and apoptosis rate as well as the mRNA expression of Caspase-3, Caspase-9 and Bcl-2 were determined.@*RESULTS@#Paclitaxel could decrease the MDA-MB-231 and MCF-7 cell proliferation activity as well as Bcl-2 mRNA expression, and increase MDA-MB-231 and MCF-7 cell apoptosis rate as well as Caspase-3 and Caspase-9 mRNA expression in dose-dependent manners; with the same dose of paclitaxel treatment, the inhibitory effects on MDA-MB-231 cell proliferation activity and Bcl-2 mRNA expression as well as the promoting effects on MDA-MB-231 cell apoptosis and mRNA expression of Caspase-3 and Caspase-9 were weaker than those on MCF-7 cell; after 0.5 μM paclitaxel combined with Notch1-siRNA treatment, MDA-MB-231 cell proliferation activity and Bcl-2 mRNA expression were significantly lower than those after 0.5 μM paclitaxel combined with control plasmid treatment while cell apoptosis rate and mRNA expression of Caspase-3 and Caspase-9 were higher than those after 0.5 μM paclitaxel combined with control plasmid treatment.@*CONCLUSIONS@#Targeted inhibition of Notch1 gene may enhance the killing effects of paclitaxel on triple negative breast cancer cells by up-regulating the expression of Caspase-3 and Caspase-9 and inhibiting the expression of Bcl-2.

Effect of Notch1 gene knockdown on migration and proliferation of human prostate cancer cell line PC-3 / 肿瘤研究与临床

Objective To investigate the effect of Notch1 gene dowuregulated on migration and proliferation of human prostate cancer cell line PC-3.Methods The small interfering RNA (siRNA) targeted Notch1 gene or negative control sequences was transfected into PC-3 cells.The expression of Notch1 or Hes1 gene was detected by Real-Time PCR and Western Blot.Then ability of migration or proliferation was measured by Transwell assay or MTS Assay.Results Compared with negative control group (36.097±1.941) and untransfected group (38.762±1.897),Notch1 expression level in siRNA group (3.960±0.510) was significantly reduced (P ＜ 0.01).Meanwhile,Hes1 level in siRNA group was decreased,expression in three groups as follows:siRNA group was 1.690±0.994,negative control group was 8.776±0.916,untransfected group was 9.803±1.001 (P ＜ 0.01).In Transwell assay,the number of migration cells in siRNA group was 657.867±27.610,more than that in the negative control group (158.533±18.263) and untransfected group (146.933±15.733) (P ＜ 0.01).In MTS assay,there was no significant difference among three groups at 0 h point,however,siRNA group was significantly raised at the time points of 24,48 and 72 h (P ＜ 0.01).Conclusions Downregulation of Notch1 gene by transfection of the siRNA-Notch1 sequences significantly promoted ability of migration or proliferation in PC-3 cells,and the effect may be due to the down-regulation of Hes1 expression.

Mutation of Notch1 gene and its protein expression in T-cell lymphoma / 白血病·淋巴瘤

Objective To investigate the effect of the expression of Notch1 protein and the mutation of Notch1 gene in.T-cell lymphoma (TCL).Methods Immunohistochemistry was used to detect the expression of Notch1 protein,and PCR amplification and DNA sequencing were used to detect the mutation of Notch1 gene in the 26th and 27th HD domain and the 34th PEST domain in 30 cases.10 cases of reactive hyperplasia tissues of lymph node were as the control.Results The positive rates of Notch1 protein expression and Notch1 gene mutation were 70.0 ％ (21/30) and 56.7 ％ (17/30).8 cases of Notch1 mutations were detected in the HD domain,6 cases in the PEST domain,and 3 case in both HD and PEST domains.Inscrtion,deletion,nonsense mutation and missense mutation were included in Notch 1 mutations.Conclusion Notch1 gene mutation may play an important role in the expression of Notch1 protein.The occur of TCL is related to the expression of Notch1 protein and the mutation of Notch1 gene.

Role of Notch - 1 in the Differentiation of Rat Mesenchymal Stem Cells into Neurons / 重庆医科大学学报

Objectives; To identify the roles of Notch - 1 gene for survivaland differentiation of mesenchymal stem cells ( MSCs) into neurons by way of RNA interference ( RNAi) technique to suppress expression of Notch - 1 gene. Methods; Firstly, construct mNotch - 1 short hairpin RNA (mNotch -IshRNA) and then to oberve configuration of MSCs transfected by mNotch - IshRNA; MTT was employed to evaluate the survival ratio of MSCs before transfection, 24 hours and 3 days after transfection, respectively; agents, such as BDNF, retinoid acid, were obtained to induce MSCs transfected by mNotch - IshRNA in vitro and expression of Nestin, NSE and NF200( neuron marker agent) and GFAP( neural glial cell marker agent) were determined by immunocytochemistry stain technique. Results: The cell cubic configuration was enforced and expression of notch - 1 gene vanished by transfection of mNotch -IshRNA. The survival ratio of MSCs by transfection decreased and there was significant differences between non - ransfection and transfection - controlling group after 24 hours and 3 days of transfection ( P