反义人myc基因的表达对食管癌细胞恶性生长的抑制

本文构建了一个含有反义人c-myc基因片段(第三外显子及3’旁侧序列)的逆转录病毒载体——pDAM3.用磷酸钙沉淀法将pDAM3导入病毒包装细胞PA317,经过筛选获得病毒效价8×10~5CFU/ml的单克隆病毒包装细胞,DNA杂交分析证实病毒载体序列稳定地整合到PA317细胞中.利用DAM3病毒成功地感染了人食管癌细胞系EC8712,得到G418抗性细胞EC-DAM3,RNA杂交结果表明EC-DAM3细胞中存在着大量的反义mycRNA分子.EC-DAM3细胞的生长速率较之EC8712细胞下降50％,[~3H]胸腺嘧啶核苷掺入降低45％,细胞在裸鼠体内形成肿瘤的能力受到明显抑制.     

RETROVIRUS MEDIATED TRANSFER OF ANTISENSE HUMAN c-myc GENE INTO HUMAN ESOPHAGEAL CANCER CELLS SUPPRESSED CELL PROLIFERATION AND MALIGNANCY

A retroviral vector, called pDAM3, containing the neomycin resistant gene and the antisense human c-myc gene fragment (the third exon and 3'flanking sequence) was constructed. pDAM3 was introduced into amphotropic packaging cells PA317 by the calcium phosphate precipitation method. Several G418-resistant PA317 clones were isolated. The virus titer of these cell lines was determined by infectivity of their cuhure fluid to NIH/3T3 cells. The highest titer obtained was 8×10~5 G418-resistant colony forming units/ml. Clonal and pooled G418-resistant PA317 colonies with high titers were expanded and analyzed by Southern blot for the presence of intact viral sequences. All cell lines were found to harbor the internal sequences of the pDAM3 vector without any rearrangement. Recombinant virus DAM3 infected human esophageal cancer cell line EC8712 efficiently. The DAM3-infected EC8712 (called EC-DAM3) was found to contain the full DAM3 sequence (4.8kb) by Southern blot analysis. Antisense myc RNA expressed in th     

浅谈物理概念的教学

物理概念是物理知识的重要组成部分;是物理定律,公式和理论的基础。在中专物理教学中正确建立物理概念是学生学习过程中的一个质的飞跃,是物理教学的首要任务,也是提高物理教学质量的关键。 1 帮助学生形成表象 在物理概念教学中,首先要帮助学生形成表象,为学生正确掌握物理概念创造必要的条件。