Possible involvement of queuine in regulation of cell proliferation.
An increase in cell number is one of the most prominent characteristics of cancer cells. This may be caused by an increase in cell proliferation or decrease in cell death. Queuine is one of the modified base which is found at first anticodon position of specific tRNAs. It is ubiquitously present throughout the living system except mycoplasma and yeast. The tRNAs of Q-family are completely modified to Q-tRNAs in terminally differentiated somatic cells, however hypomodification of Q-tRNA is closely associated with cell proliferation and malignancy. Queuine participates at various cellular functions such as regulation of cell proliferation, cell signaling and alteration in the expression of growth associated proto-oncogenes. Like other proto-oncogenes bcl2 is known to involve in cell survival by inhibiting apoptosis. Queuine or Q-tRNA is suggested to inhibit cell proliferation but the mechanism of regulation of cell proliferation by queuine or Q-tRNA is not well understood. Therefore, in the present study regulation in cell proliferation by queuine in vivo and in vitro as well as the expression of cell death regulatory protein Bcl2 are investigated. For this DLAT cancerous mouse, U87 cell line and HepG2 cell line are treated with different concentrations of queuine and the effect of queuine on cell proliferation and apoptosis are studied. The results indicate that queuine down regulates cell proliferation and expression of Bcl2 protein, suggesting that queuine promotes cell death and participates in the regulation of cell proliferation.
School of Studies in Biochemistry, Jiwaji University, Gwalior, India.
Chandramani
C
Pathak
Yogesh K
YK
Jaiswal
Manjula
M
Vinayak
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006147:Guanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008099:Liver / Q000187:drug effects; D008223:Lymphoma / Q000188:drug therapy; D008297:Male; D051379:Mice; D008806:Mice, Inbred AKR; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D012345:RNA, Transfer, Amino Acid-Specific / Q000187:drug effects / Q000378:metabolism; D014407:Tumor Cells, Cultured
D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012345:RNA, Transfer, Amino Acid-Specific; C052617:Bcl2 protein, mouse; D006147:Guanine; C019549:queuine