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AKT1 loss correlates with episomal HPV16 in vulval intraepithelial neoplasia.

Ekeowa-Anderson AL, Purdie KJ, Gibbon K, Byrne CR, Arbeit JM, Harwood CA, O'Shaughnessy RF - PLoS ONE (2012)

Bottom Line: Dysregulation of AKT, a serine/threonine kinase, plays a significant role in several cancers.We show that HPV16 early gene expression reduced AKT1 expression in transgenic mouse epidermis.Maintained AKT1 expression correlated with low copy number, an increased frequency of integration and increased HPV16E7 expression, a finding we replicated in another untyped cohort of vSCC.

View Article: PubMed Central - PubMed

Affiliation: Centre for Cutaneous Research, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.

ABSTRACT
Anogenital malignancy has a significant association with high-risk mucosal alpha-human papillomaviruses (alpha-PV), particularly HPV 16 and 18 whereas extragenital SCC has been linked to the presence of cutaneous beta and gamma-HPV types. Vulval skin may be colonised by both mucosal and cutaneous (beta-, mu-, nu- and gamma-) PV types, but there are few systematic studies investigating their presence and their relative contributions to vulval malignancy. Dysregulation of AKT, a serine/threonine kinase, plays a significant role in several cancers. Mucosal HPV types can increase AKT phosphorylation and activity whereas cutaneous HPV types down-regulate AKT1 expression, probably to weaken the cornified envelope to promote viral release. We assessed the presence of mucosal and cutaneous HPV in vulval malignancy and its relationship to AKT1 expression in order to establish the corresponding HPV and AKT1 profile of normal vulval skin, vulval intraepithelial neoplasia (VIN) and vulval squamous cell carcinoma (vSCC). We show that HPV16 is the principle HPV type present in VIN, there were few detectable beta types present and AKT1 loss was not associated with the presence of these cutaneous HPV. We show that HPV16 early gene expression reduced AKT1 expression in transgenic mouse epidermis. AKT1 loss in our VIN cohort correlated with presence of high copy number, episomal HPV16. Maintained AKT1 expression correlated with low copy number, an increased frequency of integration and increased HPV16E7 expression, a finding we replicated in another untyped cohort of vSCC. Since expression of E7 reflects tumour progression, these findings suggest that AKT1 loss associated with episomal HPV16 may have positive prognostic implications in vulval malignancy.

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Copy number and integration analysis of VIN.A. Copy number analysis of HPV16 DNA in AKT1 −ve (p = 5) and AKT +ve (p = 6) VIN. *, p = 0.006 (unpaired T-test). B. PCR of DNA for a region encompassing the HPV16 E1 and E2 genes in the 14 VIN, and the relationship with AKT1 loss in the VIN. L. 250 bp DNA ladder, W, no DNA control.
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pone-0038608-g004: Copy number and integration analysis of VIN.A. Copy number analysis of HPV16 DNA in AKT1 −ve (p = 5) and AKT +ve (p = 6) VIN. *, p = 0.006 (unpaired T-test). B. PCR of DNA for a region encompassing the HPV16 E1 and E2 genes in the 14 VIN, and the relationship with AKT1 loss in the VIN. L. 250 bp DNA ladder, W, no DNA control.

Mentions: As AKT1 loss was only detected in a subset of HPV16 positive VIN, we investigated whether this correlated with the physical status (episomal versus integrated) of the viral genome; we hypothesise that only episomal HPV16 is capable of lifecycle completion which concomitantly requires AKT1 down-regulation [11]. HPV16 copy number was increased on average 16-fold in AKT1 negative VIN (Figure 4A). The average copy number per cell in AKT1 positive VIN was less than 1, suggestive of genome integration [24]. We tested for HPV16 integration in the 11 HPV16 positive VIN by PCR using primers encompassing the E1 and E2 genes of HPV16 (Figure 4B), whose loss correlates with an integrated viral genome [25]. PCR product was detected in 4/5 (80%) of the AKT1 negative, HPV16 positive VIN tested, compared with 1/6 (17%) of the AKT1 positive, HPV16 positive VIN (p = 0.08, Fishers Exact Test). An alpha-1 antitrypsin PCR product was detected in all E1-E2 negative samples, suggesting that these negative results were not due to lack of DNA integrity. Although not reaching significance, this suggested that HPV16 was more likely to be integrated in the AKT1 positive VIN.


AKT1 loss correlates with episomal HPV16 in vulval intraepithelial neoplasia.

Ekeowa-Anderson AL, Purdie KJ, Gibbon K, Byrne CR, Arbeit JM, Harwood CA, O'Shaughnessy RF - PLoS ONE (2012)

Copy number and integration analysis of VIN.A. Copy number analysis of HPV16 DNA in AKT1 −ve (p = 5) and AKT +ve (p = 6) VIN. *, p = 0.006 (unpaired T-test). B. PCR of DNA for a region encompassing the HPV16 E1 and E2 genes in the 14 VIN, and the relationship with AKT1 loss in the VIN. L. 250 bp DNA ladder, W, no DNA control.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369856&req=5

pone-0038608-g004: Copy number and integration analysis of VIN.A. Copy number analysis of HPV16 DNA in AKT1 −ve (p = 5) and AKT +ve (p = 6) VIN. *, p = 0.006 (unpaired T-test). B. PCR of DNA for a region encompassing the HPV16 E1 and E2 genes in the 14 VIN, and the relationship with AKT1 loss in the VIN. L. 250 bp DNA ladder, W, no DNA control.
Mentions: As AKT1 loss was only detected in a subset of HPV16 positive VIN, we investigated whether this correlated with the physical status (episomal versus integrated) of the viral genome; we hypothesise that only episomal HPV16 is capable of lifecycle completion which concomitantly requires AKT1 down-regulation [11]. HPV16 copy number was increased on average 16-fold in AKT1 negative VIN (Figure 4A). The average copy number per cell in AKT1 positive VIN was less than 1, suggestive of genome integration [24]. We tested for HPV16 integration in the 11 HPV16 positive VIN by PCR using primers encompassing the E1 and E2 genes of HPV16 (Figure 4B), whose loss correlates with an integrated viral genome [25]. PCR product was detected in 4/5 (80%) of the AKT1 negative, HPV16 positive VIN tested, compared with 1/6 (17%) of the AKT1 positive, HPV16 positive VIN (p = 0.08, Fishers Exact Test). An alpha-1 antitrypsin PCR product was detected in all E1-E2 negative samples, suggesting that these negative results were not due to lack of DNA integrity. Although not reaching significance, this suggested that HPV16 was more likely to be integrated in the AKT1 positive VIN.

Bottom Line: Dysregulation of AKT, a serine/threonine kinase, plays a significant role in several cancers.We show that HPV16 early gene expression reduced AKT1 expression in transgenic mouse epidermis.Maintained AKT1 expression correlated with low copy number, an increased frequency of integration and increased HPV16E7 expression, a finding we replicated in another untyped cohort of vSCC.

View Article: PubMed Central - PubMed

Affiliation: Centre for Cutaneous Research, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.

ABSTRACT
Anogenital malignancy has a significant association with high-risk mucosal alpha-human papillomaviruses (alpha-PV), particularly HPV 16 and 18 whereas extragenital SCC has been linked to the presence of cutaneous beta and gamma-HPV types. Vulval skin may be colonised by both mucosal and cutaneous (beta-, mu-, nu- and gamma-) PV types, but there are few systematic studies investigating their presence and their relative contributions to vulval malignancy. Dysregulation of AKT, a serine/threonine kinase, plays a significant role in several cancers. Mucosal HPV types can increase AKT phosphorylation and activity whereas cutaneous HPV types down-regulate AKT1 expression, probably to weaken the cornified envelope to promote viral release. We assessed the presence of mucosal and cutaneous HPV in vulval malignancy and its relationship to AKT1 expression in order to establish the corresponding HPV and AKT1 profile of normal vulval skin, vulval intraepithelial neoplasia (VIN) and vulval squamous cell carcinoma (vSCC). We show that HPV16 is the principle HPV type present in VIN, there were few detectable beta types present and AKT1 loss was not associated with the presence of these cutaneous HPV. We show that HPV16 early gene expression reduced AKT1 expression in transgenic mouse epidermis. AKT1 loss in our VIN cohort correlated with presence of high copy number, episomal HPV16. Maintained AKT1 expression correlated with low copy number, an increased frequency of integration and increased HPV16E7 expression, a finding we replicated in another untyped cohort of vSCC. Since expression of E7 reflects tumour progression, these findings suggest that AKT1 loss associated with episomal HPV16 may have positive prognostic implications in vulval malignancy.

Show MeSH
Related in: MedlinePlus