Zhang J, Ding F, Wang X
National Laboratory of Molecular Oncology, Chinese Academy of Medical Science, Beijing.
Zhonghua Yi Xue Za Zhi. 1995 Apr;75(4):211-3, 254-5.
The level of DCC mRNA expression was evaluated in tissue specimens from lung cancer patients by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) combined with Southern blot analysis. Obvious reduction of DCC gene expression was observed in 4 of 7 specimens (55%). In two specimens DCC transcript could only be detected after Southern blot hybridization of RT-PCR product. The average level of DCC expression in cancer tissue was about 45% of normal tissue as estimated by laser densitometer. We also studied DNA samples for loss of heterozygosity (LOH) at DCC locus at two polymorphic sites. Among the 15 specimens including 7 samples for RT-PCR, 9 (60%) were informative at either of two polymorphic sites. LOH was observed in 5 (55%). Two at the MspI-RFLP (restriction fragment length polymorphism) site and 3 at the site of VNTR (variable number of tandem repeat). These results suggest that allele loss and decreased expression of DCC gene are frequent events and the possible involvement of DCC gene in the pathogenesis of human lung cancer.
通过半定量逆转录聚合酶链反应（RT-PCR）结合Southern印迹分析，评估肺癌患者组织标本中DCC mRNA的表达水平。在7个标本中的4个（55%）观察到DCC基因表达明显降低。在两个标本中，只有在对RT-PCR产物进行Southern印迹杂交后才能检测到DCC转录本。通过激光密度计估计，癌组织中DCC表达的平均水平约为正常组织的45%。我们还研究了DNA样本在DCC基因座两个多态性位点的杂合性缺失（LOH）情况。在包括7个用于RT-PCR的样本在内的15个标本中，9个（60%）在两个多态性位点中的任一个位点具有信息性。观察到5个（55%）存在LOH。在MspI-RFLP（限制性片段长度多态性）位点有2个，在VNTR（可变串联重复序列）位点有3个。这些结果表明，DCC基因的等位基因缺失和表达降低是常见事件，且DCC基因可能参与了人类肺癌的发病机制。
