title: Human papillomavirus infection and immunohistochemical expression of cell cycle proteins pRb, p53, and p16(INK4a) in sinonasal diseases.
abstract: BACKGROUND
  We aimed to clarify the possible role of human papillomavirus (HPV) infection in the malignant transformation of sinonasal inverted papilloma (IP).
  
  
  METHODS
  Subjects comprised 32 patients with chronic rhinosinusitis (CRS), 17 with IP, 5 with IP and squamous cell carcinoma (IP + SCC), and 16 with primary sinonasal SCC. HPV presence, viral loads, and physical status were investigated using polymerase chain reaction. Retinoblastoma (pRb), p53, and p16(INK4a) gene products were investigated by immunohistochemistry.
  
  
  RESULTS
  HPV DNA was detected in 6.3 % of cases with CRS, 29.4 % with IP, 40 % with IP + SCC, and 25 % with SCC. IP cases had significantly higher HPV presence than CRS cases (p = 0.04). High-risk HPV-16 was the most frequently encountered subtype (10/13, 76.9 %). HPV-16 viral loads varied from 2.5 to 7953 E6 copies/50 ng genomic DNA. Patients in the SCC and IP + SCC groups had significantly higher viral loads than those in the IP and CRS groups (p < 0.01). All SCC and IP + SCC patients with HPV-16 demonstrated mixed-type integration, whereas 4 of 5 HPV-16 patients in the IP and CRS groups showed episomal type infection (p = 0.04). Positivity to pRb was found in 78.1 % of CRS, 35.3 % of IP, and 68.8 % of SCC cases. The presence of HPV DNA negatively correlated with pRb expression in SCC (p = 0.029) and IP (P = 0.049) groups. Although 62.5 % of SCC cases exhibited p53 positivity, only 5.9 % of IP, and no CRS cases were positive. Regardless of HPV status, p16(INK4a) positivity was frequently detected in IP cases (82.4 %), less in SCC (12.5 %) cases, and was not detected in the CRS group. Neither the IP nor SCC cohorts showed any correlation between HPV presence and the expression of either p53 or p16(INK4a).
  
  
  CONCLUSIONS
  HPV infection was more frequent in the IP, IP + SCC, and SCC groups than the CRS group. Higher viral loads and integration observed in the IP + SCC and SCC groups, and an inverse correlation between HPV presence and positive pRb indicated that persistent infection and integration play a part in tumorigenesis and malignant transformation in certain IP cases. However, p16(INK4a) is not a reliable surrogate marker for HPV infection in IP.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Yukashi
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hasegawa
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.|Department of Otorhinolaryngology, Head and Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Zeyi
authors.initials: Z
authors.lastname: Deng
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Maeda
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kondo
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Asanori
authors.initials: A
authors.lastname: Kyuna
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Sen
authors.initials: S
authors.lastname: Matayoshi
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Agena
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Uehara
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Shiga University of Medical Science, Otsu, 520-2192 Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kouzaki
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Shiga University of Medical Science, Otsu, 520-2192 Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Ikegami
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ganaha
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, 903-0215 Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Suzuki
keywords: Cell cycle protein; Human papillomavirus; Integration; Inverted papilloma; Malignant transformation; Sinonasal disease; Viral load