Secondary primary malignancy in patients with head and neck squamous cell carcinoma: 27-year experience from the perspective of diagnostic tools.

BACKGROUND: The survival rate of head and neck squamous cell carcinoma (HNSCC) patients with secondary primary malignancy (SPM) showed no significant improvement for decades, however, the impact of advances in diagnostic tools is rarely mentioned. This study investigated the clinical characteristic of HNSCC with SPM over a 27-year period especially from the perspective of diagnostic tools. METHODS: This study evaluated 157 HNSCC patients with SPM. The patients were divided into two groups according to the time of SPM diagnosis (Group A:1992-2003; Group B: 2004-2014). Age, gender, stage of first primary malignancy (FPM), SPM interval, overall survival, and disease-free survival were compared between groups. RESULTS: Group B had significantly more SPM developed rate (p = 0.002), more SPM patients with advanced stage of FPM (p = 0.001), synchronous SPM (p = 0.006), and shorter SPM interval (p<0.001) compared to Group A. The survival rate in Group B was not significantly better than Group A. CONCLUSION: Among patients diagnosed with HNSCC recently, more SPMs are diagnosed in a shorter time interval and in a more advanced stage. The overall advances in diagnostic tools cannot significantly improve SPM survival, however, it enables more patients to receive corresponding treatment.

Correlation Between Objective and Subjective High-Pitched Voice Impairment in Patients After Thyroid Surgery.

Objectives: High-pitched voice impairment (HPVI) is not uncommon in patients without recurrent laryngeal nerve (RLN) or external branch of superior laryngeal nerve (EBSLN) injury after thyroidectomy. This study evaluated the correlation between subjective and objective HPVI in patients after thyroid surgery. Methods: This study analyzed 775 patients without preoperative subjective HPVI and underwent neuromonitored thyroidectomy with normal RLN/EBSLN function. Multi-dimensional voice program, voice range profile and Index of voice and swallowing handicap of thyroidectomy (IVST) were performed during the preoperative(I) period and the immediate(II), short-term(III) and long-term(IV) postoperative periods. The severity of objective HPVI was categorized into four groups according to the decrease in maximum frequency (Fmax): <20%, 20-40%, 40-60%, and >60%. Subjective HPVI was evaluated according to the patient's answers on the IVST. Results: As the severity of objective HPVI increased, patients were significantly more to receive bilateral surgery (p=0.002) and have subjective HPVI (p<0.001), and there was no correlation with IVST scores. Among 211(27.2%) patients with subjective HPVI, patients were significantly more to receive bilateral surgery (p=0.003) and central neck dissection(p<0.001). These patients had very similar trends for Fmax, pitch range, and mean fundamental frequency as patients with 20-40% Fmax decrease (p>0.05) and had higher Jitter, Shimmer, and IVST scores than patients in any of the objective HPVI groups; subjective HPVI lasted until period-IV. Conclusion: The factors that affect a patient's subjective HPVI are complex, and voice stability (Jitter and Shimmer) is no less important than the Fmax level. When patients have subjective HPVI without a significant Fmax decrease after thyroid surgery, abnormal voice stability should be considered and managed. Fmax and IVST scores should be interpreted comprehensively, and surgeons and speech-language pathologists should work together to identify patients with HPVI early and arrange speech therapy for them. Regarding the process of fibrosis formation, anti-adhesive material application and postoperative intervention for HPVI require more future research.

Prognostic Indicators of Non-Transection Nerve Injury and Vocal Fold Motion Impairment After Thyroid Surgery - Correlation Between Intraoperative Neuromonitoring Findings and Perioperative Voice Parameters.

Objectives: In patients with recurrent laryngeal nerve (RLN) injury after thyroid surgery, unrecovered vocal fold motion (VFM) and subjective voice impairment cause extreme distress. For surgeons, treating these poor outcomes is extremely challenging. To enable early treatment of VFM impairment, this study evaluated prognostic indicators of non-transection RLN injury and VFM impairment after thyroid surgery and evaluated correlations between intraoperative neuromonitoring (IONM) findings and perioperative voice parameters. Methods: 82 adult patients had postoperative VFM impairment after thyroidectomy were enrolled. Demographic characteristics, RLN electromyography (EMG), and RLN injury mechanism were compared. Multi-dimensional voice program, voice range profile and Index of voice and swallowing handicap of thyroidectomy (IVST) were administered during I-preoperative; II-immediate, III-short-term and IV-long-term postoperative periods. The patients were divided into R/U Group according to the VFM was recovered/unrecovered 3 months after surgery. The patients in U Group were divided into U1/U2 Group according to total IVST score change was <4 and ≥4 during period-IV. Results: Compared to R Group (42 patients), U Group (38 patients) had significantly more patients with EMG >90% decrease in the injured RLN (p<0.001) and thermal injury as the RLN injury mechanism (p=0.002). Voice parameter impairments were more severe in U Group compared to R Group. Compared to U1 group (19 patients), U2 Group (19 patients) had a significantly larger proportion of patients with EMG decrease >90% in the injured RLN (p=0.022) and thermal injury as the RLN injury mechanism (p=0.017). A large pitch range decrease in period-II was a prognostic indicator of a moderate/severe long-term postoperative subjective voice impairment. Conclusion: This study is the first to evaluate correlations between IONM findings and voice outcomes in patients with VFM impairment after thyroid surgery. Thyroid surgeons should make every effort to avoid severe type RLN injury (e.g., thermal injury or injury causing EMG decrease >90%), which raises the risk of unrecovered VFM and moderate/severe long-term postoperative subjective voice impairment. Using objective voice parameters (e.g., pitch range) as prognostic indicators not only enables surgeons to earlier identify patients with low voice satisfaction after surgery, and also enable implementation of interventions sufficiently early to maintain quality of life.

How the Severity and Mechanism of Recurrent Laryngeal Nerve Dysfunction during Monitored Thyroidectomy Impact on Postoperative Voice.

Intraoperative neuromonitoring can qualify and quantify RLN function during thyroid surgery. This study investigated how the severity and mechanism of RLN dysfunction during monitored thyroid surgery affected postoperative voice. This retrospective study analyzed 1021 patients that received standardized monitored thyroidectomy. Patients had post-dissection RLN(R2) signal <50%, 50-90% and >90% decrease from pre-dissection RLN(R1) signal were classified into Group A-no/mild, B-moderate, and C-severe RLN dysfunction, respectively. Demographic characteristics, RLN injury mechanisms(mechanical/thermal) and voice analysis parameters were recorded. More patients in the group with higher severity of RLN dysfunction had malignant pathology results (A/B/C = 35%/48%/55%, p = 0.017), received neck dissection (A/B/C = 17%/31%/55%, p < 0.001), had thermal injury (p = 0.006), and had asymmetric vocal fold motion in long-term postoperative periods (A/B/C = 0%/8%/62%, p < 0.001). In postoperative periods, Group C patients had significantly worse voice outcomes in several voice parameters in comparison to Group A/B. Thermal injury was associated with larger voice impairments compared to mechanical injury. This report is the first to discuss the severity and mechanism of RLN dysfunction and postoperative voice in patients who received monitored thyroidectomy. To optimize voice and swallowing outcomes after thyroidectomy, avoiding thermal injury is mandatory, and mechanical injury must be identified early to avoid a more severe dysfunction.

Downregulation of ATM and BRCA1 Predicts Poor Outcome in Head and Neck Cancer: Implications for ATM-Targeted Therapy.

ATM and BRCA1 are DNA repair genes that play a central role in homologous recombination repair. Alterations of ATM and BRCA1 gene expression are found in cancers, some of which are correlated with treatment response and patient outcome. However, the role of ATM and BRCA1 gene expression in head and neck cancer (HNC) is not well characterized. Here, we examined the prognostic role of ATM and BRCA1 expression in two HNC cohorts with and without betel quid (BQ) exposure. The results showed that the expression of ATM and BRCA1 was downregulated in BQ-associated HNC, as the BQ ingredient arecoline could suppress the expression of both genes. Low expression of either ATM or BRCA1 was correlated with poor overall survival (OS) and was an independent prognostic factor in multivariate analysis (ATM HR: 1.895, p = 0.041; BRCA1 HR: 2.163, p = 0.040). The combination of ATM and BRCA1 expression states further improved on the prediction of OS (HR: 4.195, p = 0.001, both low vs. both high expression). Transcriptomic analysis showed that inhibition of ATM kinase by KU55933 induced apoptosis signaling and potentiated cisplatin-induced cytotoxicity. These data unveil poor prognosis in the HNC patient subgroup with low expression of ATM and BRCA1 and support the notion of ATM-targeted therapy.

CYP26A1 Is a Novel Biomarker for Betel Quid-Related Oral and Pharyngeal Cancers.

Betel quid (BQ) has been classified as a Group I human carcinogen in light of evidence demonstrating an association with an elevated risk of oral and pharyngeal cancers. To date, the incidence rate of oral and pharynx cancers among Taiwanese men ranks the highest worldwide. However, no study has yet confirmed variants of CYP26A1 was associated with the risks of oral and pharyngeal cancers. A case-control study was conducted (n = 339). CYP26A1 polymorphism was performed using SNP assay. Real-time qRT-PCR and Western blotting were used to determine the levels of CYP26A1 expression. The cancer cell model involved treatment with arecoline. Our findings showed that the downregulation of CYP26A1 mRNA and protein expression are more frequently observed in cancerous tissues than adjacent normal tissues in patients with oral and pharynx cancers (p < 0.01). We found that CYP26A1 was downregulated as the arecoline dose increased. We hypothesized that lower levels of CYP26A1 mRNA expression can be utilized a clinically biomarker causes oral and pharynx cancers. Arecoline appears to modulate CYP26A1 expression through specific pathways. Carriers of CYP26A1 SNP, rs2068888 (G/G)/rs4418728 (G/G) and who have lower levels of CYP26A1 expression are associated with an increased risk of oral and pharyngeal cancers.

Downregulation of the DNA Repair Gene DDB2 by Arecoline Is through p53's DNA-Binding Domain and Is Correlated with Poor Outcome of Head and Neck Cancer Patients with Betel Quid Consumption.

Arecoline is the principal alkaloid in the areca nut, a component of betel quids (BQs), which are carcinogenic to humans. Epidemiological studies indicate that BQ-chewing contributes to the occurrence of head and neck cancer (HNC). Previously, we have reported that arecoline (0.3 mM) is able to inhibit DNA repair in a p53-dependent pathway, but the underlying mechanism is unclear. Here we demonstrated that arecoline suppressed the expression of DDB2, which is transcriptionally regulated by p53 and is required for nucleotide excision repair (NER). Ectopic expression of DDB2 restored NER activity in arecoline-treated cells, suggesting that DDB2 downregulation was critical for arecoline-mediated NER inhibition. Mechanistically, arecoline inhibited p53-induced DDB2 promoter activity through the DNA-binding but not the transactivation domain of p53. Both NER and DDB2 promoter activities declined in the chronic arecoline-exposed cells, which were consistent with the downregulated DDB2 mRNA in BQ-associated HNC specimens, but not in those of The Cancer Genome Atlas (TCGA) cohort (no BQ exposure). Lower DDB2 mRNA expression was correlated with a poor outcome in HNC patients. These data uncover one of mechanisms underlying arecoline-mediated carcinogenicity through inhibiting p53-regulated DDB2 expression and DNA repair.

Cricopharyngeal myotomy for delayed Cricopharyngeal dysfunction after head and neck surgery - case report.

BACKGROUND: Head and neck surgeries can perturb normal structures of neck muscles and nerve innervations, which are supposed to function in harmony to allow complicated process like swallowing. It is still likely that cricopharyngal dysfunction emerges years after the head and neck surgeries. CASE PRESENTATION: We report a case with history of left unilateral vocal cord immobility and development of dysphagia and aspiration 2 years after radical thyroidectomy with neck lymph nodes dissection and medialization thyroplasty. Cricopharyngeal dysfunction was impressed and was confirmed with visualization of cricopharyngeal narrowing segment in radiographic contrast swallow examination. The patient was treated successfully by cricopharyngeal myotomy, achieving long-term relief in our 4 years of follow up. CONCLUSIONS: Our case of delayed cricopharyngal dysfunction after radical thyroidectomy and medialization thyroplasty shows that it is important to follow up swallowing functions after patients with UVCI undergo medialization thyroplasty. In the event of delayed manifestation of cricopharyngeal function, it can still be treated successfully by cricoharyngeal myotomy, achieving long term relief of dysphagia.

Contralateral migration of Kirschner wire from right acromioclavicular joint to left side of neck: a case report.

BACKGROUND: Kirschner wire migration is one of the most common complications after internal fixation of fracture or dislocation in the shoulder region. However, cases of contralateral wire migration are rare. We present a case of contralateral loosened Kirschner wire migration from the right acromioclavicular joint to the left side of the neck without damage to any important structures or great vessels. CASE PRESENTATION: We report a case of a loosened Kirschner wire migrating from the right acromioclavicular joint to the left side of the neck in a 34-year-old Taiwanese man following a route of transversal, descendant, and then ascendant directions. The Kirschner wire was removed by exploratory neck dissection under C-arm fluoroscopy assistance without complication. CONCLUSION: Wire migration may occur after surgical treatment with or without clinical complaint. Several hypotheses for the mechanism of wire migration have been postulated, including muscular activity, respiratory motion, gravity, and motion of upper extremity. Therefore, the importance of follow-up should be communicated to the patient. Once wire loosening or migration is noted, the implant should be removed immediately under intraoperative C-arm fluoroscopy or ultrasound assistance.

Post-radiation sinusitis is associated with recurrence in nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy.

BACKGROUND: This study investigated the impact of post-radiation sinusitis on the prognosis of nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiation therapy (IMRT). METHODS: Two hundred and thirty patients with non-metastatic NPC were analyzed in terms of freedom from local failure (FFLF), freedom from distant failure (FFDF), overall survival (OS), and disease-free survival (DFS). For each patient, the status of the sinus mucosa was flexibly assessed by documenting mucosal changes as indicated by differences between images obtained before radiotherapy and more than 6 months post-radiation. RESULTS: With a median follow-up of 39.7 months (8 to 81 months), 19 (8.26%) patients relapsed locally, 13 (5.65%) patients failed in the neck, and 26 (11.3%) patients developed distant metastases. The presence of sinusitis noted in images post-radiation was a significant predictor for DFS (p = 0.001), FFLF (p = 0.004), and FFDF (p = 0.015), in addition to having high negative predictive value for local relapse (97.5%). CONCLUSIONS: This is the first study to investigate the prognostic value of post-radiation sinusitis in NPC patients treated with IMRT. Post-radiation sinusitis was found to be a significant predictor for DFS, FFLF, and FFDF, and was also found to have high negative predictive value for local recurrence (97.5%). It may thus be used as an additional tool for clinicians to determine the possibility of recurrence.

Variants in FAT1 and COL9A1 genes in male population with or without substance use to assess the risk factors for oral malignancy.

A number of genetic variants were suggested to be associated with oral malignancy, few variants can be replicated. The aim of this study was to identify significant variants that enhanced personal risk prediction for oral malignancy. A total of 360 patients diagnosed with oral squamous cell carcinoma, 486 controls and 17 newly diagnosed patients with OPMD including leukoplakia or oral submucous fibrosis were recruited. Fifteen tagSNPs which were derived from somatic mutations were genotyped and examined in associations with the occurrence of oral malignancy. Environmental variables along with the SNPs data were used to developed risk predictive models for oral malignancy occurrence. The stepwise model analysis was conducted to fit the best model in an economically efficient way. Two tagSNPs, rs28647489 in FAT1 gene and rs550675 in COL9A1 gene, were significantly associated with the risk of oral malignancy. The sensitivity and specificity were 85.7% and 85.5%, respectively (area under the receiver operating characteristic curve (AUC) was 0.91) for predicting oral squamous cell carcinoma occurrence with the combined genetic variants, betel-quid, alcohol and age. The AUC for OPMD was only 0.69. The predictive probability of squamous cell carcinoma occurrence for genetic risk score without substance use increased from 10% up to 43%; with substance use increased from 73% up to 92%. Genetic variants with or without substance use may enhance risk prediction for oral malignancy occurrence in male population. The prediction model may be useful as a clinical index for oral malignancy occurrence and its risk assessments.

IL-8 promotes inflammatory mediators and stimulates activation of p38 MAPK/ERK-NF-κB pathway and reduction of JNK in HNSCC.

This investigation identifies interleukin 8 (IL-8) as the main inflammatory mediator in head and neck squamous cell carcinoma (HNSCC). The expressions of chemokines of IL-8, IL-1ß and IL-6 and the cytokines of tumor necrosis factor-α (TNF-α) were higher in HNSCC patient tissues than in non-cancerous matched tissues (NCMT) whereas the expression of IL-10 was lower. IL-8 is most highly expressed in the tissues of patients with HNSCC. Treatment of HNSCC cells with IL-8 increased the secretion of IL-1ß, IL-6 and TNF-α and reduced IL-10 expression; the increase in the expression of IL-1ß was particularly considerable. IL-8 silencing by siRNA reduced IL-1ß expression in HNSCC cells, suggesting that IL-8 as a main inflammatory mediator improved IL-1ß expression in HNSCC. The expressions of p-p38 mitogen-activated protein kinases (MAPK) and p-extracellular signal regulated kinase (p-ERK) were higher and that of p-c-Jun-NH2-terminal kinase (p-JNK) was lower in HNSCC patient tissues than in NCMT. IL-8 treatment induced p-p38 MAPK and p-ERK expression, but reduced p-JNK expressions in HNSCC cells. IL-8 siRNA suppressed p38 MAPK and ERK but increased JNK expression in HNSCC cells. Exposure of SCC25 cells to IL-8, increased the expressions of p-IκB-α and nuclear factor (NF)-κB, suggesting that IL-8 regulates inflammatory response by modulating the MAPK and NF-κB pathway in HNSCC cells. IL-8 promotes the migration of SCC25 cells and increases matrix metalloproteinase-2 (MMP-2) and MMP-9 expressions. These results reveal that IL-8 is the major stimulus of inflammatory mediation in HNSCC progression and migration by activating the p38 MAPK/ERK-NF-κB pathway and reducing JNK.

Endoscopic screening for synchronous esophageal neoplasia among patients with incident head and neck cancer: Prevalence, risk factors, and outcomes.

Esophageal squamous-cell neoplasia (ESCN) is a common second primary neoplasia found in patients with head-and-neck squamous-cell carcinoma (HNSCC). This study sought to identify the risk factors for synchronous ESCN and how they influence survival in HNSCC patient. Eight hundred and fifteen incident HNSCC patients were prospectively recruited for endoscopy screening for ESCN using white-light imaging, narrow-band imaging, Lugol chromoendoscopy, and pathological confirmation. Associated lifestyle and clinicopathological data were collected. The interquartile follow-up period cutoffs were 11.3, 20.5 and 34.9 months. 124 patients (15.2%) were diagnosed as having synchronous ESCN (66 low-grade dysplasia, 29 high-grade dysplasia, and 29 esophageal squamous-cell carcinoma). Consumption of alcohol, but not betel nut or cigarette, was significantly associated with the presence of synchronous ESCN (adjusted odds ratio [aOR] = 7.1 and 10.9 for former and current drinkers, respectively). There was an interaction between cumulative dose of alcohol consumption and alcohol flushing response on the development of ESCN. High-dose drinkers with flush response were 16.9 times more likely to have esophageal high-grade dysplasia/SCC than non-drinkers. Compared with oral cavity cancer patients, those with hypopharyngeal, laryngeal and oropharyngeal cancer were 6.8, 4.6 and 2.8 times more likely to have esophageal high-grade dysplasia/SCC. HNSCC patients with synchronous ESCN had lower overall survival than those without (p < 0.0001). In conclusion, surveillance of ESCN is strongly recommended for the high-risk subpopulation of HNSCC patients, especially drinkers who have a flush response to alcohol, and those with distant metastasis of index cancer and cancers in hypopharynx, oropharynx and larynx.

Exploring the expression bar code of SAA variants for gastric cancer detection.

We reported an integrated platform to explore serum protein variant pattern in cancer and its utility as a new class of biomarker panel for diagnosis. On the model study of serum amyloid A (SAA), we employed nanoprobe-based affinity mass spectrometry for enrichment, identification and quantitation of SAA variants from serum of 105 gastric cancer patients in comparison with 54 gastritis patients, 54 controls, and 120 patients from other cancer. The result revealed surprisingly heterogeneous and most comprehensive SAA bar code to date, which comprises 24 SAA variants including SAA1- and SAA2-encoded products, polymorphic isoforms, N-terminal-truncated forms, and three novel SAA oxidized isotypes, in which the variant-specific peptide sequence were also confirmed by LC-MS/MS. A diagnostic model was developed for dimension reduction and computational classification of the 24 SAA-variant bar code, providing good discrimination (AUC = 0.85 ± 3.2E-3) for differentiating gastric cancer group from gastritis and normal groups (sensitivity, 0.76; specificity, 0.81) and was validated with external validation cohort (sensitivity, 0.71; specificity, 0.74). Our platform not only shed light on the occurrence and modification extent of under-represented serum protein variants in cancer, but also suggested a new concept of diagnostic platform by serum protein variant profile.

Combined Genetic Biomarkers and Betel Quid Chewing for Identifying High-Risk Group for Oral Cancer Occurrence.

We integrated genetic risk scores (GRS) and environmental factors for identifying high-risk subjects for oral squamous cell carcinoma (OSCC) occurrence by using case-control study. A total of 447 patients diagnosed with OSCC and 580 unrelated subjects were recruited from two medical centers in Taiwan. A multinomial logistic regression model was conducted to access interaction between GRS and betel quid (BQ) chewing. We employed ROC curve to compare the accuracy of OSCC occurrence. Four tag SNPs were found in NOTCH1, BRCA1, COL9A1, and HSPA13 genes that were significantly associated with OSCC occurrence. GRS was calculated by the four tag SNP risk alleles. The higher GRS (scores = 4) remained independently associated with risk of OSCC after adjustment for age, the use of alcohol, BQ, and cigarette: adjusted OR = 4.42 [95% confidence interval (95% CI), 1.34-14.55]. The GRS and BQ chewing interaction showed an increased risk for OSCC occurrence with adjusting for other substance use and age (OR = 70.77; 95% CI, 8.70-575.73). The synergy index was 16.58 (95% CI, 2.27-70.56), suggesting a positive additive interaction between GRS and BQ chewing. The areas under the ROC curves (AUROC) were 0.91 for combined GRS and BQ chewing with sensitivity of 88.6% and specificity of 86.7%. The AUROC of GRS and BQ chewing is above 90%, which may be valuable in identifying high-risk subjects. Early screening can allow the clinician to provide the appropriate intervention and to reduce the OSCC occurrence. Cancer Prev Res; 10(6); 355-62. ©2017 AACR.

Adverse Health Effects of Betel Quid and the Risk of Oral and Pharyngeal Cancers.

Global reports estimate 600 million betel quid (BQ) chewers. BQ chewing has been demonstrated not only to be a risk factor for cancers of the oral cavity and pharynx and oral potentially malignant disorders (OPMD) but also to cause other cancers and adverse health effects. Herein, we summarized the international comparison data to aid in the understanding of the close relationship between the prevalence of BQ chewing, the occurrence of oral and pharyngeal cancers, and adverse health effects. Potential biomarkers of BQ carcinogens, such as areca nut, alkaloids, and 3-methylnitrosaminopropionitrile (MNPN), are closely associated with human health toxicology. Molecular mechanisms or pathways involving autophagy, hypoxia, COX-2, NF-κB activity, and stemness are known to be induced by BQ ingredients and are very closely related to the carcinogenesis of cancers of oral and pharynx. BQ abuse-related monoamine oxidase (MAO) gene was associated with the occurrence and progress of oral and pharyngeal cancers. In summary, our review article provides important insights into the potential roles of environmental BQ (specific alkaloid biomarkers and nitrosamine products MNPN) and genetic factors (MAO) and offers a basis for studies aiming to reduce or eliminate BQ-related OPMD and oral/pharyngeal cancer incidences in the future.

IL-8 promotes HNSCC progression on CXCR1/2-meidated NOD1/RIP2 signaling pathway.

NOD1 (nucleotide-binding oligomerization domain 1) is overexpressed in head and neck squamous cell carcinoma (HNSCC) cells, as is IL-8 in cancer cells. However, the mechanism of the IL-8-mediated overexpression of NOD in HNSCC not been identified. This study determines whether IL-8 promotes tumor progression via the NOD signaling pathway in HNSCC. Higher IL-8, NOD1 and receptor-interacting protein kinase (RIP2) expressions were observed in HNSCC tissue than in non-cancerous matched tissue (NCMT), whereas NOD2 was weakly expressed. Furthermore, IL-8 stimulated the proliferation of HNSCC cells (SCC4, SCC9 and SCC25) but not dysplastic oral mucosa DOK cells. Exposure to IL-8 increased the clonogenicity of HNSCC cells. IL-8 siRNA inhibited cell proliferation and cell colony formation, suggesting that IL-8 is involved in HNSCC cancer progression. The expressions of CXCR1 and CXCR2 were higher in HNSCC tissue than in NCMT. HNSCC cells that were exposed to IL-8 exhibited higher expression of CXCR1/2 than did controls. The blocking of IL-8 by siRNA reduced CXCR1/2 expression in HNSCC cells, suggesting that the cancer progression of HNSCC cells that is induced by IL-8 depends on CXCR1/2. Additionally, IL-8 is associated with increased NOD1 and RIP2 expression and reduced NOD2 expression in three types of HNSCC cells. The blocking of IL-8 by siRNA reduces IL-8, NOD1 and RIP2 expressions in HNSCC cells, but not the level of NOD2. These results suggest that IL-8 has an important role in HNSCC progression via a CXCR1/2-meidated NOD1/RIP2 signaling pathway.

Somatic Mutations and Genetic Variants of NOTCH1 in Head and Neck Squamous Cell Carcinoma Occurrence and Development.

A number of genetic variants have been associated with cancer occurrence, however it may be the acquired somatic mutations (SMs) that drive cancer development. This study investigates the potential SMs and related genetic variants associated with the occurrence and development of head and neck squamous cell carcinoma (HNSCC). We identified several SMs in NOTCH1 from whole-exome sequencing and validated them in a 13-year cohort of 128 HNSCC patients using a high-resolution melting analysis and resequencing. Patients who have NOTCH1 SMs show higher 5-year relapse-free recurrence (P = 0.0013) and lower survival proportion (P = 0.0447) when the risk-associated SMs were analysed by Cox proportional hazard models. Interestingly, the NOTCH1 gene rs139994842 that shares linkage with SMs is associated with HNSCC risk (OR = 3.46), increasing when SMs in NOTCH1 are involved (OR = 7.74), and furthermore when there are SMs in conjunction to betel quid chewing (OR = 32.11), which is a related independent environmental risk factor after adjusting for substances use (alcohol, betel quid, cigarettes) and age. The findings indicate that betel quid chewing is highly associated with NOTCH1 SMs (especially with changes in EGF-like domains), and that rs139994842 may potentially serve as an early predictive and prognostic biomarker for the occurrence and development of HNSCC.

Xeroderma pigmentosum, complementation group D expression in H1299 lung cancer cells following benzo[a]pyrene exposure as well as in head and neck cancer patients.

DNA repair genes play critical roles in response to carcinogen-induced and anticancer therapy-induced DNA damage. Benzo[a]pyrene (BaP), the most carcinogenic polycyclic aromatic hydrocarbon (PAH), is classified as a group 1 carcinogen by International Agency for Research on Cancer. The aims of this study were to (1) evaluate the effects of BaP on DNA repair activity and expression of DNA repair genes in vitro and (2) examine the role of xeroderma pigmentosum, complementation group D (XPD) mRNA expression in human head and neck cancers. Host cell reactivation assay showed that BaP inhibited nucleotide excision repair in H1299 lung cancer cells. DNA repair through the non-homologous end-joining pathway was not affected by BaP. Real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) and Western blot demonstrated that XPD was downregulated by BaP treatment. BaP exposure did not apparently affect expression of another 11 DNA repair genes. BaP treatment increased the DNA damage marker γ-H2AX and ultraviolet (UV) sensitivity, supporting an impairment of DNA repair in BaP-treated cells. XPD expression was also examined by quantitative RT-PCR in 68 head and neck cancers, and a lower XPD mRNA level was found in smokers' cancer specimens. Importantly, reduced XPD expression was correlated with patient 5-year overall survival rate (35 vs. 56%) and was an independent prognostic factor (hazard ratio: 2.27). Data demonstrated that XPD downregulation was correlated with BaP exposure and human head and neck cancer survival.