Genotype-phenotype correlations in RHOBTB2-associated neurodevelopmental disorders

PurposeMissense variants clustering in the BTB domain region of RHOBTB2 cause a developmental and epileptic encephalopathy with early-onset seizures and severe intellectual disability.MethodsBy international collaboration, we assembled individuals with pathogenic RHOBTB2 variants and a variable spectrum of neurodevelopmental disorders. By western blotting, we investigated the consequences of missense variants in vitro.ResultsIn accordance with previous observations, de novo heterozygous missense variants in the BTB domain region led to a severe developmental and epileptic encephalopathy in 16 individuals. Now, we also identified de novo missense variants in the GTPase domain in 6 individuals with apparently more variable neurodevelopmental phenotypes with or without epilepsy. In contrast to variants in the BTB domain region, variants in the GTPase domain do not impair proteasomal degradation of RHOBTB2 in vitro, indicating different functional consequences. Furthermore, we observed biallelic splice-site and truncating variants in 9 families with variable neurodevelopmental phenotypes, indicating that complete loss of RHOBTB2 is pathogenic as well.ConclusionBy identifying genotype-phenotype correlations regarding location and consequences of de novo missense variants in RHOBTB2 and by identifying biallelic truncating variants, we further delineate and expand the molecular and clinical spectrum of RHOBTB2-related phenotypes, including both autosomal dominant and recessive neurodevelopmental disorders.     

T-cell bispecific antibodies in node-positive breast cancer: novel therapeutic avenue for MHC class I loss variants

BackgroundTumor-infiltrating lymphocytes (TILs) represent a prognostic factor for survival in primary breast cancer (BC). Nonetheless, neoepitope load and TILs cytolytic activity are modest in BC, compromising the efficacy of immune-activating antibodies, which do not yet compete against immunogenic chemotherapy.Patients and methodsWe analyzed by functional flow cytometry the immune dynamics of primary and metastatic axillary nodes [metastatic lymph nodes (mLN)] in early BC (EBC) after exposure to T-cell bispecific antibodies (TCB) bridging CD3ε and human epidermal growth factor receptor 2 (HER2) or Carcinoembryonic Antigen-Related Cell Adhesion Molecule 5 (CEACAM5), before and after chemotherapy. Human leukocyte antigen (HLA) class I loss was assessed by whole exome sequencing and immunohistochemistry. One hundred primary BC, 64 surrounding ‘healthy tissue’ and 24 mLN-related parameters were analyzed.ResultsHLA loss of heterozygosity was observed in EBC, at a clonal and subclonal level and was associated with regulatory T cells and T-cell immunoglobulin and mucin-domain-3 expression restraining the immuno-stimulatory effects of neoadjuvant chemotherapy. TCB bridging CD3ε and HER2 or CEACAM5 could bypass major histocompatibility complex (MHC) class I loss, partially rescuing T-cell functions in mLN.ConclusionTCB should be developed in BC to circumvent low MHC/peptide complexes.     

食管癌、胃癌细胞对氧化砷促凋亡的敏感性与固有活性氧水平有关

目的 探讨食管癌，胃癌细胞的固有活性氧（reactive oxygen species,ROS)水平与细胞对三氧化二砷（As2O3)促凋亡敏感性之间的关系。方法 用小剂量（2μmol/L)As2O3作用于人胃癌细胞和食管癌细胞株各一对（SGC7901、MKN45和EC/CUHK1、EC1867），证实As2O3促凋亡敏感性在SGC7901和MKN45之间及EC/CUHK1和EC1867之间均有差异。然后在不加As2O3的情况下，用活性氧捕获剂双氢罗丹明123（DHR123）卵育细胞（DHR123在细胞内被ROS氧化为发出荧光的罗丹明123），通过流式细胞仪检测细胞内罗丹明123的荧光而测得细胞内固有ROS水平。结果 对As2O3敏感的SGC7901细胞的固有活性氧水平比As2O3不敏感的MKN45细胞高，对As2O3敏感的EC/CUHK1细胞的固有活性氧水平比As2O3不敏感的EC1867细胞高。结论 食管癌，胃癌细胞固有ROS水平的差异与细胞对As2O3诱导凋亡的敏感性差异有关。     

Leber遗传性视神经病5家系遗传分析

目的了解LHON家系遗传特点与规律。方法调查5个LHON家系，分析该病的发生率、患者发病年龄、性别比例。结果5个家系的母系成员共82人。发病31人，发病率25．2％，男女比例20：11，平均发病年龄29．8岁，5个家系母系成员的发病率随着世代的增加而呈递减趋势，并发现4个家系呈遗传早现现象。结论LHON男性发病率高于女性，其遗传规律符合线粒体遗传的基本特点并存在遗传早现现象。     

心力衰竭大鼠心肌细胞端粒酶逆转录酶的表达

目的研究异丙肾上腺素(ISO)诱导的心力衰竭大鼠心肌细胞端粒酶逆转录酶(TERT)的表达意义。方法健康清洁级SD大鼠20只,随机分为对照组及心力衰竭模型组(ISO组)各10只,对照组腹腔注射生理盐水2 mL.kg-1,ISO组腹腔注射ISO30 mg.kg-1,均每日1次,连续2 d,给药结束观察48 h。检测大鼠血清肌酸激酶(CK)、乳酸脱氢酶(LDH)水平,计算心脏系数,同时检测心肌细胞超氧化物歧化酶(SOD)活性和丙二醛(MDA)水平;应用Western blotting方法检测TERT蛋白表达的变化;利用免疫组织化学方法检测TERT蛋白在心肌细胞中的定位。结果与对照组比较,ISO组大鼠血清CK、LDH明显升高(P<0.01),心肌坏死程度加重,心脏系数也显著增加(P<0.01);ISO组大鼠心肌细胞MDA明显升高(P<0.05),SOD活性显著下降(P<0.01);对照组心肌细胞未见TERT蛋白表达,ISO组大鼠心肌细胞TERT蛋白表达明显增加,免疫组织化学实验结果显示ISO组大鼠心肌细胞浆中和胞核内有TERT阳性免疫产物生成。结论心力衰竭大鼠心脏存在心肌细胞增殖,心肌细胞增殖对心功能有代偿作用。     

全反式维甲酸激活人肺腺癌细胞系GLC-82中-PIG-B高度同源基因-PIGB1

目的：探讨全反式维甲酸（all-trans retinlic acid,ＡＴＲＡ）诱导肿瘤细胞分化的分子机制。方法：采用Ｓouthern和Ｎorthern杂交方法对本室用ＡＴＲＡ诱导人肺腺癌细胞ＧＬＣ－８２,经消减杂交所构建的cＤＮＡ消减文库ＰＩＧＢ１,该基因与人ＰＩＧ－Ｂ（phosphaidylinlsitol glycan of clmplementaion class Ｂ）基因高度同源,在多种胎儿组织中均有表达。结论：ＰＩＧＢ１基因可能参与ＡＴＲＡ诱导肿瘤细胞分化过程。