A STRATEGY FOR ISOLATING DIFFERENTIATIONINDUCING COMPLEMENTARY DNAs FROM HUMAN ESOPHAGEAL CANCER CELL LINE TREATED WITH RETINOIC ACID

Treatment of the human esophageal cancer cell line EC8712 with retinoic acid (RA) stopped the cell growth significantly and gave rise to terminal differentiation of the cells characterized by increased expression of involucrin gene. Two cDNA libraries were constructed from the parental and RA-treated cells respectively. Repeated subtractive hybridization of single-stranded plasmid DNA prepared from pooled colonies of cDNA library of the parental cells with cDNA probe generated from the RA-treated cells exhausted sequences common to both libraries of the cell. The unhybridized cDNA probe represented, therefore, the genes activated after RA-treatment. By using these enriched cDNAs as probe to screen the cDNA library constructed from the RA-treated cells thirty-nine positive colonies were obtained, of which two were specifically due to RA-induction. One of these two cDNA clones, designated as pRA538, has undergone further analysis and shown differentiation-inducing effect on parental cancer cells. A novel     

体外化学诱发人食管成纤维细胞恶性转化

从一例52岁食管鳞癌患者的食管组织得到的原代成纤维细胞.经用化学致癌物(N-methyl-N’-nitro-N-nitrosoguanidine,MNNG)处理后。诱发了恶性转化.细胞显示恶性细胞的生物学及形态学特性,如失去接触抑制、体外无限制的生长、非整倍体性、ConA凝集性、细胞表面微绒毛形成,在琼脂固体培养基上生长,在免疫抑制的新生小鼠上接种形成肿瘤(低分化纤维肉瘤).     

MALIGNANT TRANSFORMATION OF HUMAN FETAL LUNG FIBROBLASTS INDUCED BY NITROSAMINE COMPOUNDS IN VITRO

This report, for the first time, demonstrates that diethyl-nitrosamine (NDEA) and a new nitrosamine compound-N-l-methylacetonyl-N-3-methylbutyl-nitrosamine (MAMBNA), which are suspicious carcinogens of esophageal cancer (EC) in Linxian, Henan Province, are able to cause the malignant transformation (altered morphology, extended life span, anchorage independent growth, invasiveness, tumorigenicity, etc.) of normal diploid fibroblasts derived from human fetal lung. Besides, the preselection for clonogenic cells, which seem to be more readily to be transformed, in soft agar before carcinogen treatment, could be considered as one of the useful ways in establishment of a model system of malignant transformation of human fibroblasts in vitro.     

EB病毒进入非B淋巴细胞的机理研究——一株可产生EB病毒的人和树鼩的杂交细胞株的建立

本文用可产生EB病毒的类淋巴母细胞株H_(18)与正常树(鼠句)鼻咽部组织培养单层细胞共同培养,建立了一株能产生EB病毒的人和树(鼠句)的杂交细胞株——TuH_(18),讨论了EB病毒进入非B淋巴细胞的机理,研究了TuH_(18)病毒的生物学和生物化学特性。     

电感耦合等离子体质谱法测定饮用水中23种元素

以Sc,Ge,Y,Rh,Re作内标,用电感耦合等离子质谱法测定水源水中23种元素的含量,23种元素的方法检出限在0.0005～0.3μg/L之间,混合标准溶液平行测定的相对标准偏差不大于6.69%(n=7),饮用水样品的加标回收率在82.0%～116.2%之间。该法可用于饮用水中多种元素的同时测定。     

碘催化的无溶剂三组分Strecker反应合成α-氰基化合物

醛、胺与三甲基硅氰在无溶剂条件下,通过碘催化的三组分Strecker反应合成了α-氰基化合物,收率86%～99%,其结构经1H NMR,IR和元素分析表征.