Rufforny Irina, Wilkinson Edward J, Liu Chen, Zhu Haizhen, Buteral Michael, Massoll Nicole A
Department of Pathology, Immunology and Laboratory Medicine, University of Florida/Shands Hospital, Gainesville, Florida, USA.
J Low Genit Tract Dis. 2005 Apr;9(2):108-13. doi: 10.1097/00128360-200504000-00007.
Vulvar intraepithelial neoplasia (VIN) is defined histopathologically by distinctive abnormalities of cellular maturation and differentiation. The purpose of this study was to investigate the functional properties of VIN related to expression of p16(INK4a) protein as well as to detection of human papillomavirus (HPV) type 16 by real-time polymerase chain reaction (RT-PCR) analysis.
A total of 49 vulvar biopsy samples were examined by hematoxylin-eosin staining from benign/reactive lesions, condyloma acuminatum, VIN, and invasive squamous cell carcinoma (SCC). JC8 mouse monoclonal antibodies were used that recognize p16(INK4a) epitope at a dilution of 1:25. The reaction pattern for p16(INK4a) was graded in each sample between 0 and 3+. RT-PCR analysis of formalin-fixed paraffin-embedded sections determined positivity for HPV type 16.
p16(INK4a) immunoreactivity was different in VIN 1, VIN 2, VIN 3, and squamous cell carcinoma. Strong expression of p16(INK4a) protein was observed in 92% (22 of 24) of VIN 2 and VIN 3 lesions and 100% (4 of 4) of invasive SCCs. Two (67%) of 3 VIN 2 lesions, 17 (81%) of 21 VIN 3 lesions, and 4 (100%) of 4 SCCs were positive for HPV type 16 by PCR analysis. Two (20%) of 10 VIN 1 lesions were immunoreactive for p16(INK4a), with only 1 lesion positive for HPV type 16. No p16(INK4a) immunoreactivity was observed in any of the benign/reactive and condyloma acuminatum lesions. In addition, none of the benign/reactive or condyloma lesions were positive for HPV type 16 by RT-PCR analysis.
Upregulation of INK4a gene occurs in vulvar carcinogenesis. p16(INK4a) is not a sensitive marker for differentiation of benign vulvar squamous epithelium from condyloma acuminatum or VIN 1 lesions because most VIN 1 lesions are p16(INK4a) negative. Expression of p16(INK4a) may aid in the diagnosis of HPV-related lesions and as such may be of value as a surrogate marker in the diagnosis of vulvar premalignant and malignant lesions.
外阴上皮内瘤变（VIN）在组织病理学上由细胞成熟和分化的明显异常所定义。本研究的目的是通过实时聚合酶链反应（RT-PCR）分析，研究与p16（INK4a）蛋白表达以及16型人乳头瘤病毒（HPV）检测相关的VIN的功能特性。
对49例来自良性/反应性病变、尖锐湿疣、VIN和浸润性鳞状细胞癌（SCC）的外阴活检样本进行苏木精-伊红染色检查。使用JC8小鼠单克隆抗体，以1:25的稀释度识别p16（INK4a）表位。在每个样本中，将p16（INK4a）的反应模式在0至3+之间进行分级。对福尔马林固定石蜡包埋切片进行RT-PCR分析，以确定16型HPV的阳性情况。
p16（INK4a）免疫反应性在VIN 1、VIN 2、VIN 3和鳞状细胞癌中有所不同。在92%（24例中的22例）的VIN 2和VIN 3病变以及100%（4例中的4例）的浸润性SCC中观察到p16（INK4a）蛋白的强表达。通过PCR分析，3例VIN 2病变中有2例（67%）、21例VIN 3病变中有17例（81%）以及4例SCC中有4例（100%）16型HPV呈阳性。10例VIN 1病变中有2例（20%）对p16（INK4a）呈免疫反应性，只有1例病变16型HPV呈阳性。在任何良性/反应性和尖锐湿疣病变中均未观察到p16（INK4a）免疫反应性。此外，通过RT-PCR分析，没有良性/反应性或尖锐湿疣病变16型HPV呈阳性。
INK4a基因上调发生在外阴癌发生过程中。p16（INK4a）不是区分良性外阴鳞状上皮与尖锐湿疣或VIN 1病变的敏感标志物，因为大多数VIN 1病变p16（INK4a）呈阴性。p16（INK4a）的表达可能有助于HPV相关病变的诊断，因此可能作为外阴癌前和恶性病变诊断中的替代标志物具有价值。
