Relationship between CK19 expression, deregulation of normal keratinocyte differentiation pattern and high risk-human papilloma virus infection in oral and oropharyngeal squamous cell carcinoma

Abstract

BackgroundSimple epithelial keratins appear early during embryonic development and are expressed in non-stratified, ductal and pseudo-stratified epithelial tissues. CK19, the lowest molecular weight keratin, is also expressed in basal layer of squamous epithelia of mucosal surfaces. Previous studies have shown that High Risk-Human Papilloma Virus (HR-HPV) epithelial infection induces cell immortalization via E6 and E7 viral proteins and this, in turn, impairs cytokeratin expression in cancerous cells lines derived from uterine cervix. Here, we demonstrate the possible relationship between HR-HPV+ oral/oropharyngeal cancer and the high levels of CK19 expression.MethodsWe analyzed 38 cases of Oral Squamous Cell Carcinomas/ Oro-Pharyngeal Squamous Cell Carcinomas (OSCCs/OPSCCs) by Immunohistochemistry (IHC) using specific antibody (Ab) detecting CK19, by In Situ Hybridization (ISH) and Polymerase Chain Reaction (PCR) based methods in order to define the HPV infectious status. We also evaluated the variation of CK19 expression in UPCI-SCC-131 (HPV−) and UPCI-SCC-154 (HPV+) cell lines by immunocytochemistry (ICC) and flow cytometry.ResultsCK19 OSCC/OPSCC score has been identified multiplying percentage of cancer expressing cells to staining intensity. CK19 expression score in OSCCs/OPSCCs was very different between HPV+ (mean: 288.0 ± 24.3) and HPV− cancers (mean: 66.2 ± 96.9). This difference was statistically significant (p < 0.001) with a strong evidence of correlation (p < 0.001; Spearman’s R: +0.72). ROC curve analysis was performed on CK19 expression index related to HPV positivity. Heterogeneous areas of immunoreactivity varying in percentage value, intensity and/or localization were observed in normal epithelium, both perilesional and distant from the tumor with important differences between HR-HPV+ and HR-HPV− carcinomas. By ICC and flow cytometry, the two analyzed cell lines were both CK19 positive but showed a different level of expression, in particular it should be noted that the UPCI-SCC-154 (HPV+) cell line had a higher expression than UPCI-SCC-131 (HPV−).ConclusionsIn this study we demonstrated, for the first time, strong association between CK19 up-regulation and HR-HPV+ OSCCs/OPSCCs. This test has a good accuracy. We identified ROC curve with a cut-off > 195 for HR-HPV positive results (Sensitivity: 92.3 %; Specificity: 89.3 %). Furthermore, in OSCC/OPSCC, the CK19 test may be useful in identifying HR-HPV infection, the latter being related to HPV E7 potential to disrupt normal cytokeratin expression pattern.

Basaloid Squamous Cell Carcinoma of the Head and Neck: Subclassification into Basal, Ductal, and Mixed Subtypes Based on Comparison of Clinico-pathologic Features and Expression of p53, Cyclin D1, Epidermal Growth Factor Receptor, p16, and Human Papillomavirus

“…In the past, a relationship between HPV and basaloid morphology of head and neck squamous cell carcinoma has been suggested [18,19], but it is now accepted that not all BSCC cases are associated with HPV, and HPV status is more closely related to the location than histology of SCC [20,21]. A recent study suggested a relationship between high-risk HPV and CK19 expression [22], but two of three HPV-positive cases in this study were negative for CK19.…”

Cytokeratin7 expression in histologic and cytologic specimens of cystic neck metastasis from HPV positive squamous cell carcinoma of the tonsil: A case report

“…Although a growing number of studies have reported a close link between CK7 or CK19 and HPV positive OPSCC, little is known about the roles played by CK7 and CK19 in the pathogenesis of HPV‐related SCC . However, a few studies have analyzed interactions between HPV16 E7 mRNA and CK7 and CK19 in cervical cancer cell lines .…”

“…Although a growing number of studies have reported a close link between CK7 or CK19 and HPV positive OPSCC, little is known about the roles played by CK7 and CK19 in the pathogenesis of HPV-related SCC. 7,8,10 However, a few studies have analyzed interactions between HPV16 E7 mRNA and CK7 and CK19 in cervical cancer cell lines. [11][12][13] In particular, in SiHa cells containing CK7/CK19, CK19 promotes HPV16 E7 oncoprotein expression by binding to the 6-mer peptide SEQIKA of CK7, which interacts with E7 mRNA and inhibits E7 mRNA translation.…”

“…5,6 Cytokeratin (CK)7 is a crypt epithelial marker and its overexpression is associated with HR HPV infection and tonsillar SCC with a non-keratinizing morphology. 7 CK19 is also expressed in crypts 8 In this study, we report expressions of CK7, CK19, and p16 in the tissues and aspirates of metastatic tonsillar SCC presenting as cystic Fine-needle aspiration cytology (FNAC) was performed and a finding of a few squamous cells with inflammatory and necrotic debris raised suspicion of a cystic lesion, such as, a branchial cleft cyst. However, the possibility of malignancy could not be entirely excluded and biopsy was recommended.…”

“…Cytokeratin (CK)7 is a crypt epithelial marker and its overexpression is associated with HR HPV infection and tonsillar SCC with a non‐keratinizing morphology . CK19 is also expressed in crypts and CK19 expression is upregulated in HPV positive oral/OPSCC (O/OPSCC) compared with HPV negative O/OPSCC . p16 is a surrogate marker of E7 oncoprotein of HR HPV and p16 staining is used to detect cystic node metastasis from HPV positive OPSCC because p16 and HPV status remains unchanged after metastasis …”