[Apoptosis in esophageal cancer cells induced by all-trans retinoic acid].
OBJECTIVE
To study the anti-tumor effects of all-trans retinoic acid (ATRA) and mechanisms of its action.


METHODS
Human esophageal carcinoma cell line EC9706 cells were treated with ATRA at different concentration. The proliferation inhibition was examined by MTT assay. Morphological examination, TUNEL method and flow cytometry were used to detect the apoptosis and changes of cell cycle. Immunohistochemical method was used to detect the expression of apoptosis-related genes caspase-3 and bcl-2. The semi-quantification of protein expression was analyzed by pathological image analysis.


RESULTS
ATRA inhibited the proliferation of EC9706 cells moderately. Apoptosis in EC9706 cells was induced by ATRA treatment. The morphology of EC9706 cells showed changes such as nuclear chromatin condensation and fragmentation. Sub-G1 peak was found by flow cytometry. The maximal apoptosis rate was 32.6%. The expression of caspase-3 gene was enhanced. The expression of bcl-2 gene was decreased. All these effects were presented in a dose-dependent and time-depend manner.


CONCLUSIONS
Apoptosis is one of the key mechanisms of ATRA action on EC9706 cells.
Lu
Tai-Ying
TY
Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
Fan
Qing-Xia
QX
Wang
Liu-Xing
LX
Wang
Rui-Lin
RL
Zhao
Pei-Rong
PR
Lu
Shi-Xin
SX
D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004938:Esophageal Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D014212:Tretinoin / Q000008:administration & dosage / Q000494:pharmacology*
D000970:Antineoplastic Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D014212:Tretinoin; D053148:Caspase 3