Expression of human papillomavirus type 16 E7 oncoprotein alters keratinocytes expression profile in response to tumor necrosis factor-alpha.
Acute expression of E7 oncogene from human papillomavirus (HPV) 16 or HPV18 is sufficient to overcome tumor necrosis factor (TNF)-alpha cytostatic effect on primary human keratinocytes. In the present study, we investigated the molecular basis of E7-induced TNF resistance through a comparative analysis of the effect of this cytokine on the proliferation and global gene expression of normal and E7-expressing keratinocytes. Using E7 functional mutants, we show that E7-induced TNF resistance correlates with its ability to mediate pRb degradation and cell transformation. On the other hand, this effect does not depend on E7 sequences required to override DNA damage-induced cell cycle arrest or extend keratinocyte life span. Furthermore, we identified a group of 66 genes whose expression pattern differs between normal and E7-expressing cells upon cytokine treatment. These genes are mainly involved in cell cycle regulation suggesting that their altered expression may contribute to sustained cell proliferation even in the presence of a cytostatic stimulus. Differential expression of TCN1 (transcobalamin I), IFI44 (Interferon-induced protein 44), HMGB2 (high-mobility group box 2) and FUS [Fusion (involved in t(12;16) in malignant liposarcoma)] among other genes were further confirmed by western-blot and/or real-time polymerase chain reaction. Moreover, FUS upregulation was detected in HPV-positive cervical high-grade squamous intraepithelial lesions when compared with normal cervical tissue. Further evaluation of the role of such genes in TNF resistance and HPV-associated disease development is warranted.
Boccardo
Enrique
E
Virology Group, Ludwig Institute for Cancer Research, São Paulo 01323-903, Brazil. eboccardo@ludwig.org.br
Manzini Baldi
Carina Victoria
CV
Carvalho
Alex Fiorini
AF
Rabachini
Tatiana
T
Torres
César
C
Barreta
Luiz André
LA
Brentani
Helena
H
Villa
Luisa Lina
LL
D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000187:drug effects; D002472:Cell Transformation, Viral / Q000235:genetics; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism / Q000821:virology; D004249:DNA Damage; D004261:DNA Replication; D004351:Drug Resistance; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D015967:Gene Expression Regulation, Viral; D018816:Genes, cdc; D052162:Human papillomavirus 16 / Q000502:physiology*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism / Q000821:virology*; D008297:Male; D008969:Molecular Sequence Data; D050725:Papillomavirus E7 Proteins / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D016160:Retinoblastoma Protein / Q000378:metabolism; D016196:S Phase; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D050725:Papillomavirus E7 Proteins; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; D014409:Tumor Necrosis Factor-alpha; C059731:oncogene protein E7, Human papillomavirus type 16