Epigenetic inactivation of the SFRP genes is associated with drinking, smoking and HPV in head and neck squamous cell carcinoma

Abstract

The soluble frizzled receptor protein (SFRP) family encodes antagonists of the WNT pathway, and silencing of these genes, through promoter hypermethylation, leads to constitutive WNT signaling. In bladder cancers, hypermethylation of the SFRP genes occurs more often in current and former smokers and is a strong predictor of poor patient survival. Hence, we examined methylation of these genes in another tobacco-related epithelial cancer, head and neck squamous cell carcinoma (HNSCC), to determine if the pattern of tobacco exposure again predicts the epigenetic alteration of these genes. Using methylation-specific PCR, the prevalence of methylation of SFRP1, SFRP2, SFRP4 and SFRP5 was 35, 32, 35 and 29%, respectively among 350 HNSCC cases. Promoter methylation of SFRP1 occurred more often in both heavy (OR 3.5, 95% CI 0.9-13.7) and light drinkers (OR 3.7, 95% CI 1.0-14.3) compared to nondrinkers. SFRP4 promoter methylation, on the other hand, occurred at a higher prevalence in never smokers and former smokers than in current smokers, and also was independently associated with HPV16 viral DNA. A joint effects model of SFRP4 promoter methylation demonstrated that smoking status and HPV virus significantly interacted (p < 0.04) such that never smokers with HPV16 had an OR of SFRP4 methylation of 9.0 (95% CI 2.1-38.6). These results suggest that epigenetic alterations of the SFRP genes are highly prevalent in HNSCC, and that the clonal selection for these alterations is complex and may be related to the carcinogenic exposures that are known risk factors for this disease. ' 2006 Wiley-Liss, Inc.Key words: head and neck cancer; SFRP; hypermethylation; HPV; tobacco smoking; alcohol Head and neck squamous cell carcinoma (HNSCC) is the ninth most common cancer in men in the United States (U.S.) and in 2003 390,000 new cases of oral cancer and 160,000 cases of laryngeal cancer were diagnosed worldwide.1 In the U.S., it is estimated that in 2004 there were 28,260 new cases of oral and pharyngeal cancer (excluding cancers of the lip) and 10,270 laryngeal cancers, and the overall 5-year survival rate for oral and pharyngeal cancer is approximately 50%.2 HNSCC is causally linked to tobacco smoking and smokeless tobacco use, 3,4 as well as to alcohol consumption, which acts both independently and synergistically with tobacco smoking to contribute to disease. 5Human papillomavirus (HPV) infection and low dietary folate have also been implicated in the etiology of this disease. [6][7][8][9] The WNT signaling pathway, activated through the binding of WNT proteins to the membrane-bound Frizzled receptors, leads to the stabilization and increase in the levels of the transcription factor b-catenin protein. This, in turn, leads to the activation of an array of target genes involved in numerous cellular processes important in tumor development, such as cell growth and survival, intercellular adhesion and cellular morphogenesis.10 Disruption of this pathway, through activating mutations of CTNNB1 (encoding b-catenin) or loss-of-function...

Differences in methylation profiles between HPV-positive and HPV-negative oropharynx squamous cell carcinoma

“…Seventeen articles met the inclusion criteria and were eligible for further analysis. [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] The main reasons for exclusion were duplicates and studies not investigating correlation between HPV status and methylation status in OPSCC.…”

“…28,33,34,44 In other publications studying overall HNSCC, OPSCC subgroup size ranged from 9% to 80% of the total study population. [29][30][31][32][35][36][37][38][39][40][41][42][43] There was only one study that reported the distribution of average age, nicotine and alcohol consumption between HPV-positive and HPV-negative tumors of which promoter methylation was evaluated. 34 The mean age in HPV-positive tumors was 56.9 compared with 58.4 in HPV-negative tumors.…”

“…Eight studies detected methylation in HPV-positive and HPV-negative primary tumors using formalin-fixed paraffinembedded (FFPE) specimen. 28,29,32,[34][35][36][37]40 Six used fresh frozen (FF) tissue or both. 31,38,[41][42][43][44] Three studies did not report used material.…”

Epigenetic screen of human DNA repair genes identifies aberrant promoter methylation of NEIL1 in head and neck squamous cell carcinoma

“…Furthermore, it was also shown that HNSCC risk factors (drinking, smoking and HPV) are associated with epigenetic inactivation of genes, such as the SFRP genes. 11 Future experiments will be necessary to further elucidate the role of epigenetic regulation of NEIL1 expression in HNSCC and to verify whether it is a cause or consequence of tumorigenesis. DNA methylation changes might occur early in carcinogenesis and could therefore be used as an early indicator or biomarker in clinical studies.…”

WNT Signaling in Cutaneous Squamous Cell Carcinoma: A Future Treatment Strategy?

“…For example in oesophageal SCC, the frequency of ctnnb1 mutations is only 1.1%, but yet 86.4% of oesophageal SCC tumours contain mutated WNT pathway genes (Song, et al 2014), suggesting the mechanisms by which WNT signaling function is peterbed in SCC tumours, are potentially diverse. Epigenetic inactivation of WNT signaling antagonists such as the SFRP genes is not restricted to cSCC, but rather is detected in a variety of other types of SCC tumours, including oral (Paluszczak, et al 2015;Pannone, et al 2010;Sogabe, et al 2008), oesphageal (Kishino, et al 2016;Liu, et al 2011;Meng, et al 2011;Saito, et al 2014;Yang, et al 2012), cervical (Delmas, et al 2011;Siegel, et al 2015) and head & neck (HN) SCCs (Marsit, et al 2006), and thus could represent a universal mechanism of WNT activation in SCC tumours. LGK974, is well-tollerated, potent and highly efficatious in human HNSCC cells (Liu, et al 2013), suggesting it may prove a lead therapeutic in other SCCs where WNT/β-catenin signaling drives carcinogenesis.…”