Registration Dossier

Administrative data

Endpoint:
additional toxicological information
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-guideline experimental study with clearly reported methods and results. Adequate for evaluation.

Data source

Reference
Reference Type:
publication
Title:
Ortho-quinones of benzene and estrogens induce hyperproliferation of human peripheral blood mononuclear cells
Author:
Chakravarti D, Zahid M, Backora M, Myers EM, Gaikwad N, Weisenburger DD, Cavalieri EL, Rogan EG and Joshi SS
Year:
2006
Bibliographic source:
Leukemia and Lymphoma 47, 2635-2644

Materials and methods

GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Name of test materials (as cited in study report): benzene, benzene ortho-quinone

Results and discussion

Any other information on results incl. tables

BENZENE ORTHOQUINONE ADDUCT FORMATION

Both CAT-4-N7Gua (2.3 pmol/10^6 cells) and CAT-4-N3Ade adducts (0.6 pmol/10^6 cells) were detected when MNCs were treated with 75 uM benzene ortho-quinone.

QUINONE-INDUCED HYPERPROLIFERATION

Graphical data indicate that benzene ortho-quinone significantly increased the population of mitogen-induced MNCs following 7, 14 or 21 d treatment, with treatments of 25-100 uM being generally more effective at stimulating cell proliferation than 150 uM benzene ortho-quinone. The overall recovery of cells decreased during the course of the experiments (being especially reduced by  day 21) however a stimulatory response to the ortho-quinone was still apparent.

Applicant's summary and conclusion

Conclusions:
Benzene ortho-quinone stimulates proliferation of human peripheral blood mononuclear cells in vitro.
Executive summary:

The effect of benzene ortho-quinone (0-150 uM) on cell proliferation and DNA adducts formation in human mononuclear cells was investigated in vitro. Cell proliferation was significantly increased following 7, 14 or 21 d treatment although the extent of stimulation decreased with time. Both Catechol-4-N7Gua and catechol-4-N3Ade adducts were detected in cells exposed to 75 uM benzene ortho-quinone. The authors suggest that DNA damage induced by benzene ortho-quinone may promote growth of human blood mononuclear cells.