ZNRD1 mediates resistance of gastric cancer cells to methotrexate by regulation of IMPDH2 and Bcl-2.
We previously showed that downregulation of a transcription-associated gene (ZNRD1) could reverse the resistant phenotype of gastric cancer cells through regulation of the transcription of multidrug resistance gene 1 (MDR1). In the present study, we determined both known and novel differentially expressed genes in VCR-induced multidrug resistant gastric cancer cell SGC7901/VCR transfected with ZNRD1 siRNA or empty vector control. Screening was performed using the Human Cancer Xpro(tm) HC-III plus arrays, containing 3072 cancer-related cDNAs. Ten genes, involved in cell cycle control, nucleic acid binding, and protein phosphorylation, among other functions, underwent more than 5-fold change. Of the downregulated genes we chose Inosine monophosphate dehydrogenase 2 (IMPDH2) for further validation by quantitative RT-PCR. In vitro and in vivo drug sensitivity analyses revealed that inhibition of ZNRD1 and IMPDH2 activity sensitized SGC7901/VCR cells to methotrexate. Additionally, inhibition of ZNRD1 could suppress adriamycin-induced apoptosis and significantly downregulate the expression of Bcl-2, but it did not alter the expression of the glutathione-S-transferase, or intracellular glutathione content. Taken together, the findings suggest that ZNRD1 could act as a modulator of methotrexate chemotherapy in gastric cancer cells through the regulation of IMPDH2 and Bcl-2.
Hong
Liu
L
State Key Laboratory of Cancer Biology & Institute of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi Province, China.
Qiao
Taidong
T
Han
Yu
Y
Han
Shuang
S
Zhang
Xiaoyin
X
Lin
Tao
T
Gao
Juan
J
Zhao
Pengtao
P
Chen
Zhen
Z
Fan
Daiming
D
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D045744:Cell Line, Tumor; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D018432:Drug Resistance, Multiple / Q000235:genetics / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000235:genetics / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D019254:Genes, bcl-2; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D007168:IMP Dehydrogenase / Q000037:antagonists & inhibitors*; D008727:Methotrexate / Q000494:pharmacology*; D020411:Oligonucleotide Array Sequence Analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism
D000964:Antimetabolites, Antineoplastic; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; C406241:POLR1H protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D034741:RNA, Small Interfering; D007168:IMP Dehydrogenase; C501687:IMPDH2 protein, human; D005982:Glutathione Transferase; D005978:Glutathione; D008727:Methotrexate