Apoptosis induced by 5-flucytosine in human pancreatic cancer cells genetically modified to express cytosine deaminase.
OBJECTIVE
To elucidate the pattern of 5-flucytosine (5-FC)-induced apoptosis and its role in gene therapy of human pancreatic cancer.


METHODS
The human pancreatic cancer SW1990 cells (CEA-producing) were infected with recombinant adenoviruses (Adex1CEA-prCD or Adex1CEA-prZ). Expression of CD gene protein was examined by western blot. Apoptosis induced by 5-FC in human pancreatic cancer SW1990 cells genetically modified to express cytosine deaminase was observed by means of electron microscopy, DNA electrophoresis, and flow cytometry analysis techniques.


RESULTS
The SW1990 cells infected with Adex1CEA-prCD were treated with 5-FC at 100 mumol.L-1 for 48 h, and cell apoptosis was observed. Typical apoptosis morphological feature appeared and DNA ladder could be demonstrated on DNA electrophoresis. Apoptosis peak was also showed by flow cytometry. Apoptotic cells accounted for 34.6% of the cell population. Cells in G1, S, and G2/M phase of cell cycle were 64%, 11%, and 7%, respectively.


CONCLUSIONS
The apoptosis induced by 5-FC may be a primary mechanism in CD gene therapy of pancreatic cancer.
Zhang
S N
SN
Department of Gastroenterology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University of Medical Sciences, Guangzhou 510120, China.
Yuan
S Z
SZ
Zhu
Z H
ZH
Wen
Z F
ZF
Huang
Z Q
ZQ
Zeng
Z Y
ZY
D000260:Adenoviruses, Human / Q000235:genetics; D000963:Antimetabolites / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D043525:Cytosine Deaminase; D053938:DNA Fragmentation; D005437:Flucytosine / Q000494:pharmacology*; D005818:Genetic Engineering; D015316:Genetic Therapy; D006801:Humans; D009700:Nucleoside Deaminases / Q000096:biosynthesis* / Q000235:genetics; D010190:Pancreatic Neoplasms / Q000473:pathology*; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000378:metabolism
D000963:Antimetabolites; D005437:Flucytosine; D009700:Nucleoside Deaminases; D043525:Cytosine Deaminase