Metastases of squamous cell carcinoma of the head and neck show increased levels of nucleotide excision repair protein XPF in vivo that correlate with increased chemoresistance ex vivo

Institute of Toxicology, University Medical Center, Mainz, Germany.
International Journal of Oncology (Impact Factor: 3.03). 05/2010; 36(5):1277-84. DOI: 10.3892/ijo_00000612
Source: PubMed


Nucleotide excision repair (NER) is a key node of resistance of tumour cells to the anticancer drug cisplatin. Testicular germ cell tumours (TGCT) show exquisite sensitivity towards cisplatin, and this has been connected to low levels of the NER proteins ERCC1 and XPF. Tumours of some patients with advanced head and neck squamous cell carcinoma (HNSCC) regress well under cisplatin chemotherapy but prediction of responsiveness is poor. Little is known about the levels of ERCC1-XPF in HNSCC tissues and cell lines. We investigated mRNA and protein levels of ERCC1 and XPF in 13 HNSCC cell lines and seven testis tumour cell lines and examined the correlation between levels of ERCC1 and XPF and cellular resistance towards cisplatin. No significant difference in mRNA expression of either ERCC1 or XPF in the HNSCC cell lines compared to the testis tumour cell lines was observed. Significantly higher XPF protein levels were found in HNSCC cell lines compared to testis tumour cell lines resulting in cellular cisplatin resistance. The data indicate a contribution of XPF protein for the cisplatin resistance observed in HNSCC cell lines. Subsequently, XPF and ERCC1 protein expression was investigated in cancer tissue of 34 patients. XPF levels were significantly higher in metastases of HNSCC patients than in primary cancer tissue. These findings indicate a contribution of XPF protein for the observed chemoresistance in some HNSCC tissue. XPF protein may be a predictive marker for cisplatin responsiveness of metastases in HNSCC patients.

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Available from: Andreas E. Albers, Jul 25, 2014
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    • "This biomarker has not been adopted for HNSCC in part due to controversy surrounding the specificity of the employed antibody [23], [24]. Other studies found, that resistance towards platinum-based chemotherapy correlates with protein or mRNA levels of ERCC1 and XPF [21], [25], [26]. "
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    ABSTRACT: Background Induction chemotherapy is a common therapeutic option for patients with locoregionally-advanced head and neck cancer (HNC), but it remains unclear which patients will benefit. In this study, we searched for biomarkers predicting the response of patients with locoregionally-advanced HNC to induction chemotherapy by evaluating the expression pattern of DNA repair proteins. Methods Expression of a panel of DNA-repair proteins in formalin-fixed paraffin embedded specimens from a cohort of 37 HNC patients undergoing platinum-based induction chemotherapy prior to definitive chemoradiation were analyzed using quantitative immunohistochemistry. Results We found that XPF (an ERCC1 binding partner) and phospho-MAPKAP Kinase 2 (pMK2) are novel biomarkers for HNSCC patients undergoing platinum-based induction chemotherapy. Low XPF expression in HNSCC patients is associated with better response to induction chemoradiotherapy, while high XPF expression correlates with a worse response (p = 0.02). Furthermore, low pMK2 expression was found to correlate significantly with overall survival after induction plus chemoradiation therapy (p = 0.01), suggesting that pMK2 may relate to chemoradiation therapy. Conclusions We identified XPF and pMK2 as novel DNA-repair biomarkers for locoregionally-advanced HNC patients undergoing platinum-based induction chemotherapy prior to definitive chemoradiation. Our study provides insights for the use of DNA repair biomarkers in personalized diagnostics strategies. Further validation in a larger cohort is indicated.
    Full-text · Article · Jul 2014 · PLoS ONE
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    ABSTRACT: Tumor-specific biomarkers that predict resistance to DNA damaging agents may improve therapeutic outcomes by guiding the selection of effective therapies and limiting morbidity related to ineffective approaches. XPF (ERCC4) is an essential component of several DNA repair pathways and XPF-deficient cells are exquisitely sensitive to DNA damaging agents. The purpose of this study was to determine whether XPF expression levels predict clinical response to DNA damaging agents in head and neck squamous cell carcinoma (HNSCC). Quantitative immunohistochemistry was used to measure XPF expression in tumors from a cohort of 80 patients with newly diagnosed HNSCC treated with radiation therapy with or without platinum-based chemotherapy; samples were collected prospectively. Genomic DNA isolated from blood samples was analyzed for nine single nucleotide polymorphisms (SNP) in the XPF gene by using a custom array. The primary endpoint was progression-free survival (PFS). XPF expression was higher in tumors from the oral cavity than from the other sites (P < 0.01). High XPF expression correlated with early time to progression both by univariate (HR = 1.87, P = 0.03) and multivariate analysis (HR = 1.83, P = 0.05). The one year PFS for high expressers was 47% (95% CI = 31-62) compared with 72% (95% CI = 55-83) for low expressers. In addition, we identified four XPF SNPs that showed marginal association with treatment failure. Expression level of XPF in HNSCC tumors correlates with clinical response to DNA damaging agents. XPF has potential to guide next generation personalized cancer therapy.
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    ABSTRACT: Excision repair cross-complementation group 4 gene (ERCC4/XPF) plays an important role in nucleotide excision repair and participates in removal of DNA interstrand cross-links and DNA double-strand breaks. Single nucleotide polymorphisms (SNPs) in ERCC4 may impact repair capacity and affect cancer susceptibility. In this case-control study, we evaluated associations of four selected potentially functional SNPs in ERCC4 with risk of squamous cell carcinoma of the head and neck (SCCHN) in 1,040 non-Hispanic white patients with SCCHN and 1,046 cancer-free matched controls. We found that the variant GG genotype of rs2276466 was significantly associated with a decreased risk of SCCHN (OR = 0.69, 95% CI 0.50-0.96), and that the variant TT genotype of rs3136038 showed a borderline significant decreased risk with SCCHN (OR = 0.76, 95% CI: 0.58-1.01) in the recessive model. Such protective effects were more evident in oropharyngeal cancer (OR = 0.61, 95% CI: 0.40-0.92 for rs2276466; OR = 0.69, 95% CI: 0.48-0.98 for rs3136038). No significant associations were found for the other two SNPs (rs1800067 and rs1799798). In addition, individuals with the rs2276466 GG or with the rs3136038 TT genotypes had higher levels of ERCC4 mRNA expression than those with the corresponding wild-type genotypes in 90 Epstein-Barr virus-transformed lymphoblastoid cell lines derived from Caucasians. These results suggest that these two SNPs (rs2276466 and rs3136038) in ERCC4 may be functional and contribute to SCCHN susceptibility. However, our findings need to be replicated in further large epidemiological and functional studies.
    Full-text · Article · Jul 2012 · PLoS ONE
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