000 04586nas a2200433 a 4500
005 20260818095220.0
008 050929s2005 th uu|m rtt 0| a1eng d
035 _a.b11971757
099 9 _aAIT Thesis no.EV-05-31
100 1 _aGotovdorj, Tuvshinjargal
245 1 0 _aEffects of cadmium on DNA damage and expression of repair gene
260 _aPathum Thani, Thailand :
_bAsian Institute of Technology,
_c2005
300 _a64 leaves
490 1 _aThesis ;
_vno. EV-05-31
502 _aThesis (M.Sc.) - Asian Institute of Technology, 2005
500 _aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science Inter-University Program on Environmental Toxicology, Technology and Management
520 _aCadmium is a highly toxic heavy metal; however it has been used worldwide. It has been classified a human carcinogen by IARC. Cadmium is genotoxic substance due to it can cause damage to DNA and chromosome. In this study, the effects of cadmium treatment on DNA damage and repair were studied in the human lymphocytes. The dose-response relationship between cadmium treatment and DNA strand breaks was studied in the human lymphocytes treated with 5, 10, 25, 50 and 100M cadmium. Using comet assay, the effects of cadmium treatment at various concentrations caused a significant induction of DNA strand breaks in a dose-dependent manner up to 50M and slightly increased further at 100M in the human lymphocytes. A The time-course of cadmium treatment on an induction of DNA strand breaks was carried out in lymphocytes treated with cadmium for 2, 4 and 24 hours. The effects of cadmium on the DNA strand breaks were also observed in the timedependent manner in the human lymphocytes. The induction of DNA strand breaks indicated a percentage of increase from control was highest at 4 hours following cadmium treatment at all test concentrations, and then dramatically decreased towards 24 hours of treatment. Cadmium treatment at 50M for 4 hours was then selected as the optimum dose and time of cadmium on the DNA damage. The effect of cadmium treatment on the oxidized base DNA damage was studied in human lymphocytes treated at 50M cadmium for 4 hours by comet assay with formamidopyrimidine-DNA-glycosylase (Fpg). The results showed that cadmium significant increased the Fpg-sensitive sites in the human lymphocytes by 1.4-fold (P<0.05), compared to control. Cadmium can cause oxidized base DNA damage. The alterations of repair gene (hOGG1) and metallothionein (MT) gene expression were studied in human lymphocytes treated with 50M cadmium for 4 hours by Reverse-Transcriptase and Polymerase Chain Reaction (RT-PCR). Cadmium induced MT mRNA expression by 1.62-fold (P<0.01) from control. In contrast, cadmium treatment resulted in decrease in the levels of hOGG1 by 1.67-fold (P<0.01), compared to control. In conclusion, the present study demonstrated that cadmium significantly increased DNA strand breaks in human lymphocytes in a dose and time-dependent. In addition, a significant increase in oxidized base damage indicated as Fpg-sensitive base was in accordance with the reduction of repair gene (hOGG1) in human lymphocytes treated with cadmium. Therefore, cadmium can cause genotoxic to human lymphocytes possibly by induction of oxidative DNA damage and of DNA repair inhibition.
650 0 _aDNA damage
650 0 _aDNA repair
650 0 _aCadmium
700 0 _aPanida Navasumrit,
_eChairperson
700 0 _aPreeda Pakpian,
_eExamination Committee
700 1 _aPiyajit Watcharasit,
_eExamination committee
710 2 _aHer Majesty The Queen of Thailand
810 2 _aAsian Institute of Technology.
_tThesis ;
_vno. EV-05-31
856 _3Full-Text
_uhttp://203.159.5.9/ait-thesis/detail.php?q=B09401
907 _a.b11971757
_bmnait
_cu
902 _a240329
998 _b0
_c050929
_dm
_ea
_fu
_g0
945 _lmnait
945 _lmnait
945 _lmnarc
942 _c20
942 _c40
909 _aBarcode : 30050004612114
_bCREATED : 2004-02-05
_cRECORD # : i1246126x
_dLPATRON : 1017138
_eLCHKIN : 2004-09-12
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 1
_jTOT RENEW : 3
909 _aBarcode : 30050120737357
_bCREATED : 2004-02-05
_cRECORD # : i12461271
_dLPATRON : 1019610
_eLCHKIN : 2007-11-22
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 2
_jTOT RENEW : 2
909 _aBarcode : 30050160050505
_bCREATED : 2016-05-25
_cRECORD # : i12991533
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
999 _c35038
_d35038