Restoration of proliferating cell nuclear antigen (PCNA) complex formation in xeroderma pigmentosum group a cells following cis-diamminedichloroplatinum (II)-treatment by cell fusion with normal cells

✍ Scribed by Masahiko Miura; Masaharu Domon; Takehito Sasaki; Seiji Kondo; Yoshinari Takasaki

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 688 KB
• Volume: 152
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041520324

✦ Synopsis

We examined the role o C the factor deficient in xerodernia pigmentosum group A (XI'-A) cells in the formation of proliferating cell nuclear antigen (PCNA) complex with DNA in the DNA repair process in human fibrobla3ts following cisdiainminedichloroplatinum (CDDP)-treatment. Immunofluorescence staining after methanol fixation was used to detect the PCNA complex formation. When quiescent normal cells were PCNA-stained at 3 h after 100 p M CDDP treatment for 1 h, almost a11 nuclei of the cells showed a punctuated staining pattern. On the other hand, nuclei of XP-A cells were not stained. These results were the same with the findings following 10Jlm' ot ultraviolet light (UV)-irradiation. The quantitative analysis of the PCNA inimunofluorescencc intensity of normal cells revealed that the mcan intensity was increased by 4.8 times by the CDDPtreatment and 6. I timcs by the UV-irradiation, compared with that of untreated cells. The intensitics among nuclei ranged widely in both treatments. In contrast, the mean intcnsity was not increased in XP-A cells by the same treatments. However, when XP-A cells were fused with normal cells with polyethylene glycol (PEG) treatment, the nuclei of the XP-A cells showed positive PCNA-staining following CDDPtreatment or UV-irradiation in almost all cases. Thesc results suggest that the PCNA complex formalion may play a role in the DNA repair process after the slep where the factor deficient in XP-A cells is involved following CDDP-treatment as well as following UV-irradiation. fB 1992 W I I O -L ~S S ,