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Correlation between γ -H2AX, micronucleus and annual occupational dose in medical radiation workers

Authors:
  • National Nuclear Energy Agency, Jakarta, Indonesia
  • UK Health Security Agency
International Journal of Radiation Research, October 2021
Volume 19, No 4
Correlation between γ -H2AX, micronucleus and
annual occupational dose in medical radiation
workers
INTRODUCTION
       
     
 -    
      
  
       
      
      
      
 -   
    
-    
       
      
  

  
       
I.K. Hasan Basri*1, S. Barnard2, V.A. Suvivan1, T. Rahardjo1,
S. Nurhayati1, N. Rahajeng1, Y. Lusiyanti1, D. Tetriana1, M. Syukri3,
S. Purnami1, E. Hiswara1





ABSTRACT
Background: Medical workers are exposed to long -term low levels of ionizing
radiaon, which makes them vulnerable to DNA damage. There are potenal
occupaonal health hazards from radiaon exposure in a large occupaonal
segment of the populaon. Matherials and Methods: During this study, 69
blood samples were taken from 45 medical workers (including diagnosc
radiologists, radiographers, and cathlab nurses) and 24 nonmedical workers
as controls from three hospitals across Indonesia, and were analyzed for the
presence of DNA damage. Detecon of γ-H2AX expression as a biomarker of
DNA DSB damage and the micronucleus assay were carried out by
immunouorescence microscopy and Giemsa staining, respecvely. Results:
The mean γ-H2AX foci index in workers was 0.02(0.00-0.24) and in control
was 0.02(0.00-0.12), micronucleus frequency of workers (5-30 per 1000 cells)
and control (12-29 per 1000 cells). The annual occupaonal dose of workers
was recorded as (0.01-1.12 mSv). There was no stascal dierence in the
mean number of γ-H2AX foci and the micronuclei frequency between workers
and controls, but there was a small tendency toward correlaon between
γ-H2AX foci and micronuclei frequency and the annual occupaonal dose of
workers. Conclusions: γ-H2AX foci have the potenal to be used as a
biomarker to detect radiaon-induced DNA DSB damage in workers caused by
occupaonal dose exposure.
Keywords: γ-H2AX, micronucleus, occupational dose exposure, medical radiation
workers.


-
Revised: January 2021
Accepted: February 2021
Int. J. Radiat. Res., October 2021;
19(4): 1015-1023
Original article
DOI: 10.29242/ijrr.19.4.1015
Downloaded from ijrr.com at 4:46 +0330 on Monday November 8th 2021 [ DOI: 10.29242/ijrr.19.4.1015 ]
      
   -  
     
    
-
       
      
    

     

    
    
      

     
  
   
     
  
-  -   
   
      
       
        
      
     
  

     
    
        
      
       
     
  -   
-
--
    

--
     
     
-
    
-

       
    - γ-
1016
 
        
 γ-    
       
 


     -    
   
γ-    
    
γ-      
   
γ-      

     

       
      
     
     
       
     
    - 
       
   - 

    
     
      

      
 
     
     
      
   
       
     
    - 
-   
-     
     
   
     
 -
      
     
     
Int. J. Radiat. Res., Vol. 19 No. 4, October 2021
Hasan Basri et al. / DNA damage and occupational dose
Downloaded from ijrr.com at 4:46 +0330 on Monday November 8th 2021 [ DOI: 10.29242/ijrr.19.4.1015 ]
Hasan Basri et al. / DNA damage and occupational dose
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Int. J. Radiat. Res., Vol. 19 No. 4, October 2021
     
      

   


      
     
      
  γ-     
    
       
    γ-  
        

        
     
γ-      
     
   γ-    
        
    
     

MATERIALS AND METHODS

      
      
    
     

   
    
  -    
    
    
      
      
    
-
     
        
       
    
     
      
     
      
    


     
       
     





      
     

     
       

       
      
       
        

  -      

    

γ-
      
       

   -   

     
     γ-
 -- γ- 
  
   
        
      
-        
      

       
       
    - 
Downloaded from ijrr.com at 4:46 +0330 on Monday November 8th 2021 [ DOI: 10.29242/ijrr.19.4.1015 ]
   --  
      
       
       
     
         
      
        
      
        
       

    
     
      


     
-  
--   
       
  
       -
-        
      
      
     
        
      
        

    

      
     
      
      


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      
-

       γ-
      
     
      
γ-
  
      
      

RESULTS
  
   -  -
 γ- 
      - 
-     
   γ-  

  
         
       
   γ-   

     
γ-       
       
   γ-  
      
  
γ-     

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Int. J. Radiat. Res., Vol. 19 No. 4, October 2021
1018
a b
Figure 1. Mean γ-H2AX index in
controls and workers (a) and
micronucleus index in controls
and workers (b).
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Int. J. Radiat. Res., Vol. 19 No. 4, October 2021
No Code/Name Ages (Years) Sexes γ-H2AX Micronucleus Doses/Year (mili Sievert) Smoking/No
1 BS1 32 W 0,04 20 1,15 No
2 BS2 50 M 0,24 21 0,71 No
3 BS3 53 M 0,14 15 0,33 No
4 BS4 26 M 0 15 0,47 No
5 BS6 47 W 0,04 24 1,04 No
6 BS7 43 M 0,12 17 0,51 No
7 BS8 45 M 0,19 20 0,45 No
8 BS9 46 W 0 20 0,38 No
9 BS12 35 W 0 15 0,32 No
10 BS15 40 W 0 25 0,7 No
11 BS16 44 M 0 21 0,2 No
12 BS17 57 M 0,02 29 0,15 No
13 BS18 54 M 0,02 17 0,29 No
14 BS19 50 M 0,02 13 0,35 No
15 BS22 30 M 0 5 0,78 No
16 BS26 27 W 0,08 10 0,47 No
17 BS27 42 W 0 26 0,34 No
18 BS32 56 M 0 30 0,26 No
19 PD-1 35 M 0 15 0,31 No
20 PD-2 43 M 0,02 8 0,45 No
21 PD-3 43 W 0 10 0,32 No
22 PD-4 35 M 0 11 0,31 No
23 PD-5 54 W 0 6 0,3 No
24 PD-6 34 W 0 13 0,33 No
25 PD-7 43 W 0 21 0,45 No
26 PD-8 37 W 0 13 0,33 No
27 PD-9 33 W 0 15 0,36 No
28 PD-10 33 W 0,06 15 0,3 No
29 PD-11 32 W 0,02 25 0,36 No
30 PD-12 44 W 0 25 0,36 No
31 PD-13 51 M 0 12 0,51 No
32 PD-14 38 M 0 29 0,33 No
33 PD-15 44 M 0 28 0,51 No
34 PD-16 27 M 0,02 14 0,39 No
35 PD-17 55 M 0 22 0,53 No
36 PD-18 49 M 0 18 0,41 No
37 PD-19 43 W 0 25 0,37 No
38 PD-20 49 W 0 20 0,44 No
39 PD-21 29 M 0,02 26 0,41 No
40 PD-22 56 W 0 27 0,38 No
41 BS11 58 W 0,08 24 Control No
42 BS13 56 M 0,02 25 Control No
44 BS14 47 M 0 25 Control No
45 BS20 58 W 0,08 23 Control No
45 BS21 56 M 0 27 Control No
47 BS24 41 W 0 29 Control No
48 BS25 35 W 0 19 Control No
49 BS28 40 W 0 18 Control No
50 BS29 42 W 0 18 Control No
51 BS30 41 W 0 14 Control No
52 BS31 30 W 0,12 19 Control No
53 PD-25 57 W 0,02 23 Control No
54 PD-26 54 W 0 29 Control No
55 PD-27 50 W 0 21 Control No
56 PD-28 30 M 0 9 Control No
57 UL-1 28 M 0 12 Control No
58 UL-2 27 W 0,02 16 Control No
59 UL-4 42 M 0 15 Control No
60 UL-7 56 M 0 15 Control No
61 UL-9 53 W 0 14 Control No
62 UL-11 26 W 0,02 16 Control No
63 UL-12 25 W 0,02 20 Control No
64 UL-20 28 M 0 17 Control No
65 UL-23 32 M 0 25 Control No
66 UL-24 35 W 0 14 Control No
Table 1. Distribuon γ- H2AX, Micronucleus, and Occupaonal Dose of Workers and Controls.
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DISCUSSION
     


       
    
       
    
       

      
     
     
      
     

      
      
      

     
     
   
     
      
 - 
   -
      
    
   
     
      
      
      

    

      
  γ-  



 γ-     
  
       
     
   
      
  
   
    
     
       
      
    
      γ- 
    
      
γ-
       
    
      
 γ-      
      
γ
-     
  

     γ-

     
a b
Figure 2. Correlaon of γ-H2AX index and micronuclei index (a) and γ-H2AX index and annual occupaonal doses in workers (b).
Downloaded from ijrr.com at 4:46 +0330 on Monday November 8th 2021 [ DOI: 10.29242/ijrr.19.4.1015 ]
Hasan Basri et al. / DNA damage and occupational dose
1021
Int. J. Radiat. Res., Vol. 19 No. 4, October 2021
      

     
      
   γ-  
     

  
-
  γ-    
    
       
    

     
       
      
        
        
   
   γ-  
    
γ-  
     
     
  
      -
       
     
      
      
-    
 
     

   
-
       
     
     
      
-  
      
     

   
  -    
    
-     
   
  -   
     
    

      
      
    
    
γ-     
  
      
       
-
γ-
        
      

      
        

ACKNOWLEDGMENT
      
    
  
        
      
    
     

      

     
 
        
      
     

: 
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Background: H2AX is a histone variant that is systematically found and ubiquitously distributed throughout the genome. DNA double-strand breaks (DSBs) induce phosphorylation of H2AX at serine 139 (γH2AX), an immunocytochemical assay with antibodies recognizing γH2AX has become the gold standard for the detection of DSBs. The importance of this assay to investigate different individual responses to gamma irradiation was reviewed and an example of different radiation responses of ductal carcinoma tumors with different expression levels of ATM and HER-2 was discussed. Materials and Methods: The ductal carcinoma breast tissues were exposed to 4 Gy gamma rays and after 24 hours incubation in modified RPMI 1640 medium in 37 °C with CO2, the frequency of residual induced DSB was assessed using γH2AX assay compared to pair normal adjacent and control breast tissues. Results: Results showed that the frequency of DSB dramatically increased in both tumor and normal irradiated tissues, compared to sham non-irradiated controls. Tumors with HER-2 over expression showed significantly lower residual DSB frequencies after 24 hours post irradiation incubation time, whereas this frequency dramatically increased in ATM under expressed tissues. Conclusion: Our data showed that different tissues may have different radio-sensitivity and ATM under- and HER-2 over-expression may lead to higher and lower sensitivity to ionizing radiation, respectively. This may be due to the role of ATM in DSB repair and HER-2 in EGFR downstream signaling pathway that with the use of cell survival mechanisms ends to resistance against radiation effects and activation of PI3K/ACT that leads to DSB repair.
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Genome instability is a prerequisite for the development of cancer. It occurs when genome maintenance systems fail to safeguard the genome's integrity, whether as a consequence of inherited defects or induced via exposure to environmental agents (chemicals, biological agents and radiation). Thus, genome instability can be defined as an enhanced tendency for the genome to acquire mutations; ranging from changes to the nucleotide sequence to chromosomal gain, rearrangements or loss. This review raises the hypothesis that in addition to known human carcinogens, exposure to low dose of other chemicals present in our modern society could contribute to carcinogenesis by indirectly affecting genome stability. The selected chemicals with their mechanisms of action proposed to indirectly contribute to genome instability are: heavy metals (DNA repair, epigenetic modification, DNA damage signaling, telomere length), acrylamide (DNA repair, chromosome segregation), bisphenol A (epigenetic modification, DNA damage signaling, mitochondrial function, chromosome segregation), benomyl (chromosome segregation), quinones (epigenetic modification) and nano-sized particles (epigenetic pathways, mitochondrial function, chromosome segregation, telomere length). The purpose of this review is to describe the crucial aspects of genome instability, to outline the ways in which environmental chemicals can affect this cancer hallmark and to identify candidate chemicals for further study. The overall aim is to make scientists aware of the increasing need to unravel the underlying mechanisms via which chemicals at low doses can induce genome instability and thus promote carcinogenesis. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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High expression of phospho histone γ-H2AX, a sensitive marker of double stranded DNA damage, is believed to be an indication of defective DNA repair pathway or genomic instability that may cause mutations and ultimately cancer. DNA damage can be caused by ionizing radiation exposure. Beside in medical treatment/diagnosis or industry, ionizing radiation exposure can also be found in naturally in regions of high natural back ground radiation. In this study we collect the blood from 45 volunteers living in Mamuju, a region with highest natural radiation in Indonesia (dose of ∼7 mSv/year). Subjects were grouped as high natural background area (HNBA) (n = 37) and control area (n = 8). The expression γ-H2AX foci were evaluated by one of researcher fluorescence microscope examination. Our results show that the average foci numbers per cell were in the normal range. While not statistical different, the average of γ-H2AX foci in exposed area higher in the exposed compared to the control area, 0.31 versus 0.13 (p > 0.05), respectively. Moreover, there was also no statistical difference of average γ-H2AX foci between man and woman, old and young people in exposed and control area (p > 0.05). In this preliminary study we find that γ-H2AX foci (and thus DNA double strand break) frequency in residents living in the HNBA of Mamuju, West Sulawesi, show a trend towards higher (albeit not significant) average values relative to the control area. More research is needed to further scrutinize these observations.
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