DNA repair biomarkers XPF and phospho-MAPKAP kinase 2 correlate with clinical outcome in advanced head and neck cancer

Mitogen-activated protein kinase-activated protein kinase-2 (MK2) and its role in cell survival, inflammatory signaling, and migration in promoting cancer

Cancer and the immune system share an intimate relationship. Chronic inflammation increases the risk of cancer occurrence and can also drive inflammatory mediators into the tumor microenvironment enhancing tumor growth and survival. The p38 MAPK pathway is activated both acutely and chronically by stress, inflammatory chemokines, chronic inflammatory conditions, and cancer. These properties have led to extensive efforts to find effective drugs targeting p38, which have been unsuccessful. The immediate downstream serine/threonine kinase and substrate of p38 MAPK, mitogen-activated-protein-kinase-activated-protein-kinase-2 (MK2) protects cells against stressors by regulating the DNA damage response, transcription, protein and messenger RNA stability, and motility. The phosphorylation of downstream substrates by MK2 increases inflammatory cytokine production, drives an immune response, and contributes to wound healing. By binding directly to p38 MAPK, MK2 is responsible for the export of p38 MAPK from the nucleus which gives MK2 properties that make it unique among the large number of p38 MAPK substrates. Many of the substrates of both p38 MAPK and MK2 are separated between the cytosol and nucleus and interfering with MK2 and altering this intracellular translocation has implications for the actions of both p38 MAPK and MK2. The inhibition of MK2 has shown promise in combination with both chemotherapy and radiotherapy as a method for controlling cancer growth and metastasis in a variety of cancers. Whereas the current data are encouraging the field requires the development of selective and well tolerated drugs to target MK2 and a better understanding of its effects for effective clinical use.

DNA base excision repair and nucleotide excision repair proteins in malignant salivary gland tumors

OBJECTIVE

To analyze the immunohistochemical expression of the base excision repair (BER) proteins apurinic/apyrimidinic endonuclease 1 (APE1) and X-ray repair cross-complementing protein 1 (XRCC1) and nucleotide excision repair (NER) protein xeroderma pigmentosum group F (XPF) in malignant salivary gland tumors (MSGTs).

DESIGN

Sixty-two cases of MSGTs were selected, including 14 acinic cell carcinomas (AcCC), 15 polymorphous adenocarcinomas (PAC), 16 adenoid cystic carcinomas (ACC), and 17 mucoepidermoid carcinomas (MEC). The specimens were submitted to quantitative immunohistochemical analysis.

RESULTS

All MSGTs exhibited nuclear or nucleo-cytoplasmic immunostaining of APE1, XRCC1 and XPF, with a high percentage of positive cells (median = 78.31, 70.48 and 75.46, respectively). XRCC1 expression was higher in PAC compared to MEC (p = 0.032). Nuclear APE1 immunostaining was significantly higher than nucleo-cytoplasmic expression in the selected MSGTs (p < 0.0001). APE1 expression was significantly associated with T1-T2 tumors in ACC (p = 0.006). Increased expression of XPF was associated with age older than 60 years in MEC (p = 0.015) and with ACC involving the minor salivary gland (p = 0.012), while a lower expression was found in AcCC and ACC patients treated by surgery combined with adjuvant therapy (p = 0.036 and p = 0.020, respectively). Low expression of XRCC1 in the nucleus (p = 0.028) and concomitant expression of this protein in the nucleus/cytoplasm were associated with a lower overall 5-year survival rate (p = 0.017).

CONCLUSIONS

This study showed that BER and NER proteins evaluated are highly expressed in the MSGTs studied, indicating mechanisms of genotoxic control in these tumors. In addition, the dysregulation of XRCC1 expression was a prognostic predictor in MSGTs analyzed.

Immunohistochemical expression of DNA repair proteins in oral tongue and lower lip squamous cell carcinoma

The DNA repair system involves genes and proteins that are essential for the maintenance of genome integrity and the consequent control of various cellular processes. Alterations in these genes and proteins play a role in tumor development and progression and might be associated with prognosis. The aims of this study were to analyze the immunoexpression of two DNA repair proteins, XPF and XRCC1, in lower lip squamous cell carcinoma (LLSCC) and oral tongue squamous cell carcinoma (OTSCC), and to investigate possible associations with clinical and histopathological parameters. The immunohistochemical expression of XPF and XRCC1 was analyzed semi-quantitatively in 40 cases each of LLSCC and OTSCC. The chi-squared test or Fisher's exact test, when appropriate, was used to investigate the association between expression of the proteins and clinicopathological characteristics. The cytoplasmic immunoexpression of XPF was high in OTSCC (95% of the cases analyzed) but low in LLSCC (52.5%). Among the clinicopathological parameters evaluated, a statistically significant association was observed between high nuclear expression of XRCC1 and the absence of regional lymph node metastasis in patients diagnosed with OTSCC (p=0.006). The high protein expression of XPF and XRCC1 in OTSCC and LLSCC suggests an important role in the development and progression of these tumors. Our study found an association between high nuclear expression of XRCC1 and the absence of loco-regional metastasis in cases diagnosed as OTSCC, suggesting a role of this protein in tumor progression.

Immunohistochemical expression of TFIIH and XPF in oral tongue squamous cell carcinoma

PURPOSE

The query for biomarkers that indicate tumor aggressiveness and the host's response to treatment is still one of the leading aims of cancer research. To investigate a possible role for DNA nucleotide repair proteins in oral cancer behavior, this study evaluated the immunoexpression of the proteins TFIIH and XPF and its association with clinical, histological, and survival parameters in oral tongue squamous-cell carcinoma (OTSCC).

METHODS

TFIIH and XPF immunoexpressions were evaluated in 82 cases of oral tongue squamous-cell carcinoma. Tumor budding and depth of invasion were assessed for histopathological grading (BD model).

RESULTS

Tumor cells exhibited high expression of TFIIH and XPF, which was associated to nodal status; both proteins were not associated with other clinical parameters, histopathological grading or survival. Tumor size, nodal status, tumor staging, and depth of invasion > 4 mm were significantly associated to disease-specific survival.

CONCLUSIONS

We have demonstrated that the overexpression of TFIIH correlates positively with node metastasis, while XPF correlates negatively with node metastasis; therefore, the expression of XPF and TFIIH had a potential value for predicting the progression of OTSCC patients.

Immunoexpression of DNA base excision repair and nucleotide excision repair proteins in ameloblastomas, syndromic and non-syndromic odontogenic keratocysts and dentigerous cysts

OBJECTIVE

To evaluate the immunoexpression of DNA base excision repair (BER) [apurinic/apyrimidinic endonuclease 1 (APE-1), X-ray repair cross complementing 1 (XRCC-1)] and nucleotide excision repair (NER) [xeroderma pigmentosum complementation group (XPF)] proteins in benign epithelial odontogenic lesions with different biological behaviors.

DESIGN

Thirty solid ameloblastomas, 30 non-syndromic odontogenic keratocysts (NSOKCs), 29 syndromic odontogenic keratocysts (SKOCs), 30 dentigerous cysts (DCs) and 20 dental follicles (DFs) were evaluated quantitatively for APE-1, XRCC-1 and XPF through immunohistochemistry.

RESULTS

Nuclear expression of APE-1 was significantly higher in NSOKCs, SOKCs, and ameloblastomas in comparison to DCs (p < 0.001). Nuclear expression of XRCC-1 was higher in NSOKCs and SOKCs than in DCs (p < 0.05). At the nuclear level, XPF expression was higher in NSOKCs and SOKCs than in DCs and ameloblastomas (p < 0.05). A statistically significant higher expression of APE-1 (nuclear), XRCC-1 (nuclear), and XPF (nuclear and cytoplasmic) was found in all odontogenic lesion samples as compared to DFs (p < 0.05). For all lesions, there was a positive correlation between nuclear expression of APE-1 and XRCC-1 or XPF (p < 0.05).

CONCLUSIONS

Our results suggest a potential involvement of APE-1, XRCC-1 and XPF proteins in the pathogenesis of benign epithelial odontogenic lesions, especially in those with more aggressive biological behavior, such as ameloblastomas, NSOKCs, and SOKCs. We also showed that the expression of APE-1 was positively correlated with the nuclear expression of XRCC-1 and XPF, which may suggest an interaction between the BER and NER pathways in all odontogenic lesions studied herein.

MAPKAPK2 (MK2) inhibition mediates radiation-induced inflammatory cytokine production and tumor growth in head and neck squamous cell carcinoma

Radiation therapy (RT) is a cornerstone of treatment in the management of head and neck squamous cell carcinomas (HNSCC), yet treatment failure and disease recurrence are common. The p38/MK2 pathway is activated in response to cellular stressors, including radiation, and promotes tumor inflammation in a variety of cancers. We investigated MK2 pathway activation in HNSCC and the interaction of MK2 and RT in vitro and in vivo. We used a combination of an oropharyngeal SCC tissue microarray, HNSCC cell lines and patient-derived xenograft (PDX) tumor models to study the effect of RT on MK2 pathway activation and to determine how inhibition of MK2 by pharmacologic (PF-3644022) and genetic (siRNA) methods impacts tumor growth. We show that high phosphorylated MK2 (p-MK2) levels are associated with worsened disease specific survival in p16-negative HNSCC patients. RT increased p-MK2 in both p16-positive, HPV-positive and p16-negative, HPV-negative HNSCC cell lines. Pharmacologic inhibition or gene silencing of MK2 in vitro abrogated RT-induced increases in p-MK2; inflammatory cytokine expression and expression of the downstream MK2 target, heat shock protein 27 (HSP27); and markers of epithelial-to-mesenchymal transition. Mouse PDX models treated with a combination of RT and MK2 inhibitor experienced decreased tumor growth and increased survival. Our results suggest that MK2 is a potential prognostic biomarker for head and neck cancer and that MK2 pathway activation can mediate radiation resistance in HNSCC.

ERCC1, XPF and XPA-locoregional differences and prognostic value of DNA repair protein expression in patients with head and neck squamous cell carcinoma

OBJECTIVES

Nucleotide excision repair protein expression has been claimed to be responsible for platinum-based chemotherapy resistance. ERCC1, XPF and XPA, core proteins in DNA repair, were evaluated regarding their prognostic value in patients with head and neck squamous cell carcinoma by looking at overall survival and time to recurrence.

MATERIALS AND METHODS

Tissue microarrays were constructed from 453 cases of HNSCC, including 222 oral (49%), 126 oropharyngeal (27.8%) and 105 laryngeal (23.2%) tumours. There were 284 XPF, 293 XPA and 294 ERCC1 specimens evaluable for protein expression analysis after immunohistochemical workup. Expression levels were dichotomised into high- and low-expressing groups. Outcomes for overall survival (OS) and time to recurrence (TTR) were analysed using the Kaplan-Meier method.

RESULTS

No correlation between ERCC1, XPA and XPF expression and OS was found by looking at the overall patient cohort. However, subsite analysis revealed that high ERCC1 expression was associated with a significantly inferior OS in patients with SCC of the oral cavity (p = 0.028) and showed an independent predictive value in multivariate analysis (p = 0.0123). High XPA expression showed a significantly increased OS in patients with oropharyngeal SCC (p = 0.0386). Regarding XPF, no impact on OS in any subsite could be shown.

CONCLUSIONS

While high ERCC1 expression functions as a predictive marker with decreased OS in patients with squamous cell carcinoma of the oral cavity, high XPA expression shows an inverse effect in the subsite of the oropharynx, which has not been described previously.

CLINICAL RELEVANCE

ERCC1 and XPA might be candidates to overcome chemotherapy resistance in subtypes of HNSCC.

Clinical research of individualized therapy in advanced esophageal cancer based on the ERCC1 C8092A genotype

The present study aimed to explore the role and clinical value of the detection of Excision repair cross-complementing 1(ERCC1) C8092A polymorphisms in individualized therapy of patients with advanced esophageal cancer. A total of 127 patients with advanced esophageal cancer were enrolled between January 2010 and January 2014 in Anhui Provincial Hospital. Patients were randomly assigned in a 1:2 ratio to a standard treatment group or an individualized treatment group, respectively, prior to ERCC1 C8092A assessment. Patients in the standard treatment group were treated with paclitaxel and cisplatin. The DNA was obtained from the peripheral blood of individualized treatment patients, amplified by PCR and sequenced to determine the ERCC1 C8092A polymorphism prior to the administration of chemotherapies. Patients with the ERCC1 C8092A genotype of A/A or A/C received paclitaxel and cisplatin, and those with the genotype of C/C received paclitaxel and fluorouracil. The primary endpoint was response rate (RR). The secondary endpoints included toxicity of chemotherapy, progression-free survival (PFS) and overall survival (OS) times. Differences between the groups were evaluated by χ² test. Differences in survival were analyzed by Kaplan-Meier survival curves. The survival rate was analyzed by log-rank test. Follow-up data was obtained until December 2015. The RR was obtained for 15 patients (34.8%) in the standard treatment group and 45 patients (53.6%) in the individualized treatment group (χ²=3.095; P=0.046). For adverse events, nausea and vomiting and anemia were significantly decreased in the individualized treatment group compared with the standard treatment group (P=0.001 and P=0.004, respectively). The median progression free survival time was 4.4 months [95% confidence interval (CI)3.8-5.0 months] in the standard treatment group and 6.6 months (95% CI, 5.8-7.4 months) in the individualized treatment group (P=0.018). The median overall survival time was 11.4 months (95% CI, 10.1-12.7 months) in the standard treatment group and 14.2 months (95% CI, 13.2-15.2 months) in the individualized treatment group (P=0.008). The RR, toxicity of chemotherapy, PFS and OS were significantly improved in the individualized treatment group compared with the standard treatment group. Detection of ERCC1 gene polymorphisms maybe performed for patients with advanced esophageal cancer to improve individualized therapy, which requires additional study.

DNA base excision repair proteins APE-1 and XRCC-1 are overexpressed in oral tongue squamous cell carcinoma

BACKGROUND

DNA repair systems play a critical role in protecting the human genome from damage caused by carcinogens. Modifications in DNA repair genes may be responsible for tumor development and resistance of malignant cells to chemotherapeutic agents. The major pathway for oxidative DNA damage repair is the base excision repair pathway. This study aimed to assess the immunoexpression of DNA repair proteins APE-1 and XRCC-1 and its association with clinical, histologic, and survival parameters in oral tongue squamous cell carcinoma, to investigate a possible role for those proteins in tumor behavior.

METHODS

The expression of APE-1 and XRCC-1 was evaluated by immunohistochemistry in 82 cases of oral tongue squamous cell carcinoma. Histopathological grading was performed for each case. Pearson's chi-square and Fisher's exact tests were used to determine the association between protein expressions and clinicopathological features of tumors, whereas Kaplan-Meier curves and Cox regression were used to analyze disease-specific and disease-free survival. Statistical significance was set at P ≤ 0.05.

RESULTS

APE-1 was highly expressed in the nucleus and cytoplasm in 64.6% of cases, and XRCC-1 showed overexpression only in the nucleus in 61% of cases. High expression of XRCC-1 was significantly associated with tumors at early clinical stages (I and II, P < 0.01) and nodal status (P = 0.03). Both proteins were not associated with other clinical parameters, histopathological grading, or survival.

CONCLUSIONS

DNA base excision repair proteins APE-1 and XRCC-1 are upregulated in oral tongue squamous cell carcinoma, and XRCC-1 expression is associated with better clinical staging and nodal status.

Nucleotide Excision Repair: From Neurodegeneration to Cancer

DNA damage poses a constant threat to genome integrity taking a variety of shapes and arising by normal cellular metabolism or environmental insults. Human syndromes, characterized by increased cancer pre-disposition or early onset of age-related pathology and developmental abnormalities, often result from defective DNA damage responses and compromised genome integrity. Over the last decades intensive research worldwide has made important contributions to our understanding of the molecular mechanisms underlying genomic instability and has substantiated the importance of DNA repair in cancer prevention in the general population. In this chapter, we discuss Nucleotide Excision Repair pathway, the causative role of its components in disease-related pathology and recent technological achievements that decipher mutational landscapes and may facilitate pathological classification and personalized therapy.

The roles of excision repair cross-complementation group1 in objective response after cisplatin-based concurrent chemoradiotherapy and survival in head and neck cancers: a systematic review and meta-analysis

Our aim of the study was to investigate the precise relationship of repair cross-complementation group 1 (ERCC1) expression and the survival as well as objective response rate to cisplatin-based concurrent chemoradiotherapy (CCRT) and a meta-analysis was conducted to analysis ERCC1's prognostic roles in head and neck cancer. A search based on published articles in PubMed, Embase and CKNI database (up to Oct 15, 2014) to find eligible studies meeting eligibility criteria and then a meta-analysis was conducted to assess the outcomes in head and neck squamous cell carcinomas (HNSCC) patients with different ERCC1 expression. The principle outcomes were hazard ratio (HR) for survival analysis and relative risks (RR) for objective response. Fixed or random model was used for calculation according to the heterogeneity. The results showed that 9 studies involving 568 patients met the inclusion criteria. Low/negative expression of ERCC1 was associated with longer overall survival (OS) and profession-free survival (PFS) after receiving cisplatin-based CCRT therapy (HR 0.38; 95% confidence interval (CI) 0.21-0.63; P<0.001 and HR 0.37; 95%CI 0.21-0.63; P<0.001). And there was no significant difference discovered in objective response rate between low/negative and high/positive ERCC1 expression (RR 1.19; 95%CI 1.00-1.43; P=0.06). Evidence of modest heterogeneity was found between ERCC1 expression and OS (I(2)=48.8%, P<0.05) and subgroup analysis was performed based on ethnicity, variable methods and primary tumor location. The conclusion is that ERCC1 might be the one of adverse prognostic factors affecting the survival time and objective response to cisplatin-based chemoradiotherap due to its drug-resistance characteristics.