Influence of p53 status on the HSV-Tk/GCV-induced bystander effect in a panel of human ovarian carcinoma cell lines.
The p53 protein is mutated in 50% of all human tumors and plays a key role in apoptosis, cell cycle, and the expression of several genes. We investigated if p53 mutations influence the herpes simplex virus thymidine kinase (HSV-tk)/ganciclovir (GCV)-induced bystander effect (BE). Additionally, we studied some of the underlying mechanisms. GCV sensitivity and BE were studied in a human ovarian carcinoma cell line transfected with an empty vector (A2780/cmv) or a vector containing a p53 hotspot mutation at codon 175 (A2780/m175) or 248 (A2780/m248). In addition, expression levels of two nucleoside analogue transporters, multidrug resistance-related protein 4 and 5 (MRP4/MRP5), were determined. Finally, differences in gap junctional intercellular communication (GJIC) were studied by determining connexin 43 (Cx43) expression and by modulating GJIC with 18-alpha-glycyrrhetinic acid. Our results showed that compared to A2780/cmv, GCV sensitivity was significantly decreased in A2780/m175 and A2780/m248. Additionally, a significant BE (relative increase in cell kill) was found in A2780/cmv and A2780/m248. In contrast, an increased survival was observed in A2780/m175. No MRP4 or MRP5 expression was detected. However, all A2780 cell lines expressed Cx43. Modulating the GJIC significantly decreased the BE in A2780/cmv and A2780/ m248. In conclusion, HSV-tk/GCV-induced BE is influenced by p53 mutations. Differences in GJIC could be one of the underlying mechanisms.
van Dillen
Ingrid J
IJ
Department of Medical Oncology, Groningen University Hospital, PO Box 30.001, 9700 RB Groningen, The Netherlands.
Mulder
Nanno H
NH
Sluiter
Wim J
WJ
Meijer
Coby
C
de Jong
Steven
S
Loncarek
Jadranka
J
Mesnil
Marc
M
de Vries
Erik F J
EF
Vaalburg
Willem
W
Hospers
Geke A P
GA
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D024201:Bystander Effect / Q000502:physiology; D002450:Cell Communication / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D015774:Ganciclovir / Q000494:pharmacology*; D017629:Gap Junctions / Q000187:drug effects; D005910:Glioma / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology; D051381:Rats; D018139:Simplexvirus / Q000201:enzymology* / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
D000970:Antineoplastic Agents; D015774:Ganciclovir; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D013937:Thymidine Kinase; D016159:Tumor Suppressor Protein p53