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Radiotherapy plays an important role in the treatment of most of solid tumors including head and neck squamous cell carcinoma (HNSCC). Radioresistance can lead to locoregional recurrence and distant metastases. Despite significant progress in research of radioresistance, its prediction and overcoming strategies remain challenging. This review describes the potential biomarkers correlated to the radioresistance and complex signal pathway in mechanism of radioresistance focusing on the PI3K and EphA3 pathway.

Supplementary Figure Legends - PDF file 151K, Legend for Supplementary Figures S1-S6

Supplementary Figure S2 PDF - PDF file 414K, Activation of autophagy in AMC-HN-9 cells

Supplementary Methods - PDF file 168K, Additional experimental procedures, including western blot, RT-PCR, cell cycle analysis, etc. Also includes supplementary references

CD47 is expressed in all human cancer cells, including head and neck cancer, and initiates a signaling cascade to inhibit macrophage phagocytosis. However, the mechanism underlying CD47 overexpression has not been elucidated in radioresistant head and neck cancer. The present study demonstrated that decreased Tristetraprolin (TTP) expression induced a sustained overexpression of CD47 using reverse transcription-quantitative PCR and western blotting, and that CD47 overexpression prevented phagocytosis using a phagocytosis assay in a radioresistant HN31R cell line. Subsequently, using TTP transfection, RNA interference, duel-luciferase assay and EMSA, it was revealed that TTP transfection enhanced phagocytosis through degradation of CD47 mRNA by directly binding to CD47 AREs within the CD47 3'UTR. Based on our previous study, methylation-specific PCR and western blotting revealed that DNMT1 was overexpressed in radioresistant HN31R cell line and TTP expression was decreased epigenetically by DMNT1 associated DNA methylation. Overall, these findings provided novel insight into the role of TTP as a biomarker of CD47-positive head and neck cancer patients.

This study aimed to introduce our robotic technique, which can minimize dissection extent using the da Vinci SP robotic system via hairline incision.Forty patients underwent robotic thyroidectomy using the da Vinci SP robotic system via a hairline incision between February 2020 and April 2021 at Ulsan University Hospital. All procedures were performed successfully by one surgeon using the SP robotic system.Hemithyroidectomies were performed in 32 patients and total thyroidectomies in eight patients. Central neck dissection was performed in 32 patients. The overall mean operative time was 140.2 ± 50.7 min, and the mean console time was 74.0 ± 42.7 min. All patients were discharged on the second or third day after operation without any complications.Robotic thyroidectomy using the SP robotic system via hairline incision is technically feasible and safe, with a shorter incision length when compared with that of the Xi system.

EPHA3, a member of the EPH family, is overexpressed in various cancers. We demonstrated previously that EPHA3 is associated with radiation resistance in head and neck cancer via the PTEN/Akt/EMT pathway, the inhibition of EPHA3 significantly enhances the efficacy of radiotherapy in vitro and in vivo. In this study, we investigated the mechanisms of PTEN regulation through EPHA3-related signaling. Increased DNA methyltransferase 1 (DNMT1) and enhancer of zeste homolog 2 (EZH2) levels, along with increased histone H3 lysine 27 trimethylation (H3K27me3) levels, correlated with decreased levels of PTEN in radioresistant head and neck cancer cells. Furthermore, PTEN is regulated in two ways: DNMT1-mediated DNA methylation, and EZH2-mediated histone methylation through EPHA3/C-myc signaling. Our results suggest that EPHA3 could display a novel regulatory mechanism for the epigenetic regulation of PTEN in radioresistant head and neck cancer cells.

Background: Obesity/overweight is associated with a higher risk of allergic rhinitis (AR) in children. Objective: This study aimed at exploring the mechanisms by which obesity affects the severity of AR through leptin and interleukin (IL)-1β were investigated. Methods: In all, 210 subjects with AR and 82 subjects without AR were included in this study. The levels of leptin and inflammatory biomarkers were measured in the serum to investigate the correlation with the severity of AR. Additionally, we analyzed whether changes in BMI regulate the severity of AR through serial follow-up of obese children. Results: IL-1β, which is a biomarker of active inflammation in AR, was significantly higher in individuals with AR than in those without and higher in subjects in the obesity group than in those in the normal weight group. A regression analysis showed that the leptin level was associated with increased IL-1β expression in children with AR. In the multivariate analysis, only parental AR (9.2-fold increase in risk), elevated leptin (11.3-fold increase in risk), and high expression of IL-1β (5.8-fold increase in risk) emerged as significant risk factors of moderate to severe persistent allergic rhinitis. We also found that children with an increase or decrease in BMI showed changes in IL-1β and AR symptoms, which these changes were dependent on leptin and BMI. Conclusions: These results suggest that obesity is an important risk factor for the exacerbation of symptoms and leptin can exacerbate inflammation as well as severe and persistent symptoms through IL-1β in AR.

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) has attracted attention as a potential candidate for cancer therapy. However, many primary cancers are resistant to TRAIL, even when combined with standard chemotherapy. The mechanism of TRAIL resistance in cancer cells has not been fully elucidated. The TRAIL death receptor (DR) 3&prime, untranslated region (3&prime, UTR) is reported to contain AU-rich elements (AREs) that are important for regulating DR mRNA stability. However, the mechanisms by which DR mRNA stability is determined by its 3&prime, UTR are unknown. We demonstrate that tristetraprolin (TTP), an ARE-binding protein, has a critical function of regulating DR mRNA stability. DR4 mRNA contains three AREs and DR5 mRNA contains four AREs in 3&prime, UTR. TTP bound to all three AREs in DR4 and ARE3 in DR5 and enhanced decay of DR4/5 mRNA. TTP overexpression in colon cancer cells changed the TRAIL-sensitive cancer cells to TRAIL-resistant cells, and down-regulation of TTP increased TRAIL sensitivity via DR4/5 expression. Therefore, this study provides a molecular mechanism for enhanced levels of TRAIL DRs in cancer cells and a biological basis for posttranscriptional modification of TRAIL DRs. In addition, TTP status might be a biomarker for predicting TRAIL response when a TRAIL-based treatment is used for cancer.

The manner in which p53 maintains redox homeostasis and the means by which two key metabolic elements, glucose and glutamine, contribute to p53-dependent redox stability remain unclear. To elucidate the manner in which p53 deals with glucose-deprived, reactive oxygen species (ROS)-prone conditions in this regard, two isogenic cancer subclones (HN3R-A and HN3R-B) bearing distinct p53 mutations as an in vitro model of intratumoral p53 heterogeneity were identified. Following cumulative irradiation, the subclones showed a similar metabolic shift to aerobic glycolysis and increasing NADPH biogenesis for cellular defense against oxidative damage irrespective of p53 status. The radioresistant cancer cells became more sensitive to glycolysis-targeting drugs. However, in glucose-deprived and ROS-prone conditions, HN3R-B, the subclone with the original p53 increased the utilization of glutamine by GLS2, thereby maintaining redox homeostasis and ATP. Conversely, HN3R-A, the p53-deficient radioresistant subclone displayed an impairment in glutamine usage and high susceptibility to metabolic stresses as well as ROS-inducing agents despite the increased ROS scavenging system. Collectively, our findings suggest that p53 governs the alternative utilization of metabolic ingredients, such as glucose and glutamine, in ROS-prone conditions. Thus, p53 status may be an important biomarker for selecting cancer treatment strategies, including metabolic drugs and ROS-inducing agents, for recurrent cancers after radiotherapy.

Radiotherapy is a well-established therapeutic modality used in the treatment of many cancers. However, radioresistance remains a serious obstacle to successful treatment. Radioresistance can cause local recurrence and distant metastases in some patients after radiation treatment. Thus, many studies have attempted to identify effective radiosensitizers. Eph receptor functions contribute to tumor development, modulating cell-cell adhesion, invasion, neo-angiogenesis, tumor growth and metastasis. However, the role of EphA3 in radioresistance remains unclear. In the current study, we established a stable radioresistant head and neck cancer cell line (AMC HN3R cell line) and found that EphA3 was expressed predominantly in the radioresistant head and neck cancer cell line through DNA microarray, real time PCR and Western blotting. Additionally, we found that EphA3 was overexpressed in recurrent laryngeal cancer specimens after radiation therapy. EphA3 mediated the tumor invasiveness and migration in radioresistant head and neck cancer cell lines and epithelial mesenchymal transition- related protein expression. Inhibition of EphA3 enhanced radiosensitivity in the AMC HN 3R cell line in vitro and in vivo study. In conclusion, our results suggest that EphA3 is overexpressed in radioresistant head and neck cancer and plays a crucial role in the development of radioresistance in head and neck cancers by regulating the epithelial mesenchymal transition pathway.

PURPOSE The aim of this study was to evaluate the effectiveness of low-dose radioactive iodine (RAI) ablation in patients with small papillary thyroid cancer (PTC) exhibiting microscopic extrathyroidal extension (mETE) and central lymph node (CLN) metastasis. METHODS Among patients who underwent RAI ablation between March 2007 and February 2014, those who had small PTCs (≤2 cm), as well as mETE and CLN metastasis (T3 N1a M0), were enrolled. Response to ablation and long-term outcomes were assessed and compared according to the administered RAI dose. Factors associated with unsuccessful ablation were also determined. RESULTS A total of 180 patients were included in the study. Eighty-eight patients had been treated with 1110 MBq (low-dose group) and 92 with 2960 MBq (high-dose group) of RAI. There were no significant differences in the responses to ablation (P = 0.810) and long-term outcomes (P = 0.663) between both groups. Among all patients enrolled, 13 did not achieve successful ablation at long-term follow-up. Logistic regression found that a high ratio of metastatic nodes was a significant factor for predicting unsuccessful ablation. CONCLUSIONS Low-dose RAI ablation did not produce significantly different responses or long-term outcomes in patients with small PTCs exhibiting mETE and CLN metastasis. These findings suggest that low-dose ablation may be sufficient in this specific group of intermediate-risk patients, although careful selection is required for patients with a high ratio of metastatic nodes.

Anaplastic thyroid cancer (ATC) is a rare, but nearly uniformly fatal disease that is typically resistant to chemotherapy and radiation. Alternative strategies to target this cancer at a molecular level are necessary in order to improve dismal outcomes for ATC patients. We examined the effects of flavopiridol, a CDK inhibitor, in a panel of ATC cell lines. When cell lines were treated over a ten-point concentration range, CAL62, KMH2 and BHT-101 cell lines had a sub micromolar half-maximal inhibitory concentration, while no effect was seen in the non-cancerous cell line IMR-90. Flavopiridol treatment resulted in decreased levels of the cell cycle proteins CDK9 and MCL1, and induced cell cycle arrest. Flavopiridol also decreased the in vitro ability of ATC cells to form colonies and impeded migration using a transwell migration assay. In vivo, flavopiridol decreased tumor weight and tumor volume over time in a patient-derived xenograft model of ATC. Given the observed in vitro and in vivo activity, flavopiridol warrants further investigation for treatment of ATC.

Spleen tyrosine kinase (SYK) is a promoter of cell survival in a variety of cell types, including normal and cancerous epithelial cells. We hypothesized that SYK would an important therapeutic target to inhibit for the treatment of HNSCC.SYK protein abundance in patient tumours was evaluated. SYK protein and mRNA abundance was used to examine patient survival and human papillomavirus (HPV) status. Small-interfering RNAs and gene editing with CRISPR/Cas9 were used to evaluate SYK expression on proliferation in HNSCC cell lines. The potency of SYK inhibitor ER27319 maleate on cellular proliferation was tested using a panel of 28 HNSCC cell lines and in vivo in HNSCC patient-derived xenograft (PDX) models.Moderate to high protein expression of SYK was observed in 24% of patient tumors and high SYK expression was exclusively observed in HPV-positive samples (p 0.001). SYK inhibition with RNA interference, gene editing or a SYK inhibitor (ER27319) decreased cell proliferation and migration. Treatment of PDXs with ER27319 maleate was observed to reduce tumour burden in vivo in two of three models.HPV-positive HNSCC harbours high SYK protein levels. We demonstrate that proliferation, migration and overall burden of these tumours can be reduced by genetic or pharmacologic inhibition of SYK. Taken together, these data establish SYK as a therapeutic target for HNSCC.

Abtract Background The genomic landscape of head and neck cancer has been reported through The Cancer Genome Atlas project. We attempt to determine if high-risk human papillomavirus (HPV) or frequently mutated genes are correlated with survival in an oral cancer cohort. Methods Patient demographic data along with data from final pathology was collected. Tumor DNA was analyzed using a custom Illumina targeted sequencing panel. Five high-risk HPV types were tested by qPCR. Statistical analyses were used to identify associations between patient outcome and mutational status. Results High-risk HPV types were identified in 7% of cases; HPV status was not associated with survival. Mutations were identified in TP53, TERT promoter, & PIK3CA. Mutations in TP53 were significantly associated with poorer overall survival on multi-variate analysis (p = 0.03). Conclusions Mutations in TP53 were associated with poor patient survival. Expanding our sample size may identify further predictors of outcome to direct customized cancer care.

Background/aim Lymph node (LN) metastasis of solid types of tumors has important clinical significance and it is therefore critical to identify molecular biomarkers that would enable the selection of patients with LN metastases. Patients and methods We evaluated the expression of stabilin-2 in primary oral tongue tumors and metastatic LNs using immunohistochemical staining. The correlation between risk factors and nodal metastasis was assessed and disease-free survival was analyzed. Results Stabilin-2 expression remained a significant predictor of LN metastasis and the factor affecting recurrence in tongue cancer. Most importantly, all metastatic tumors of tongue, lung, stomach and colon cancers stained positive for stabilin-2 and stabilin-2 was expressed strongly in the sinusoidal endothelial cell of metastatic LNs. Conclusion Stabilin-2 can play a critical role in the first entrapping step of LN metastasis through homotypic interaction with the lymphatic endothelium and appears to be a tumor biomarker predicting for LN metastasis in patients with solid tumors.

Objectives/Hypothesis To investigate the relationship between sleep-disordered breathing (SDB) and nocturnal enuresis (NE) in children and to prospectively evaluate the effectiveness of adenotonsillectomy on resolving enuresis in indicated SDB patients with NE. Methods We prospectively collected data from 183 children (121 males, mean age 8.17 ± 2.84 years) who underwent adenotonsillectomy to treat SDB between July 2011 and July 2013, and analyzed the prevalence of NE. Before and 3 months after surgery, all parents were requested to answer a self-reported SDB scale questionnaire (22 questions, 0–22 points) and a NE questionnaire (episodes of enuresis per month). Paired t test, Student t test, and Chi-square test were used to analyze the data. Results Overall prevalence of NE was 9.3% (17 patients) preoperatively and 1.5% postoperatively (four patients). After adenotonsillectomy, prevalence of NE and the mean SDB scale were significantly decreased (both P values < 0.001). After adenotonsillectomy, 13 of the 17 NE patients (76.5%) showed complete resolution. There was significantly higher prevalence of NE in patients with obstructive sleep apnea (OSA) than those without OSA (13.1%, 14 of 107 vs. 3.9%, 3 of 76; P = 0.036). Conclusion There is strong association between NE and SDB, and adenotonsillectomy can markedly improve enuresis in the majority of children with NE and SDB. Levels of Evidence 4. Laryngoscope, 126:1241–1245, 2016

BACKGROUND CIP2A may activate multiple oncogenic proteins and promote the proliferation of various cancer cells. METHODS We investigated that the role of CIP2A in radioresistant head and neck cancer (HNC) cell line with TP53 mutation and the effect of the rapamycin on the response of HN31 with TP53 mutation cells to irradiation related to CIP2A expression. RESULTS CIP2A expression was stimulated by p53 mutation and critical for the inhibition of senescence induction in response to radiation. The treatment with radiation alone neither induced cytotoxicity in HN31 cells nor completely suppressed the activation of CIP2A. However, the combination of radiation and rapamycin increase the radiosensitivity through the induction of senescence with downregulation of CIP2A expression both in vivo and in vitro. CONCLUSION Our results suggest that CIP2A may serve as a therapeutic target of rapamycin through induction of senescence in radioresistant HNC with TP53 mutation.

Objectives Survival in head and neck squamous cell carcinoma (HNSCC) has been associated with patient sex, typically with males experiencing poorer outcomes. It is unclear if this disparity is based in divergent tumor biology. We analyzed the TCGA HNSCC cohort to uncover disparities in the somatic single nucleotide variation (SNV), copy number alteration (CNA) and mRNA abundance profiles between males and females. Critically, we stratified our results by tumor HPV status to control for this significant confounder. Methods SNV, CNA and mRNA abundance differences between males and females were compared separately for the HPV-positive (n = 67) and negative (n = 431) TCGA HNSCC cohorts. Overall survival outcomes were compared in males and females in both HPV-positive and HPV-negative subsets of patients. Results Females were found to have poorer overall survival than males (p = 0.048), largely due to higher rates of HPV-positive disease among men. SNV analysis revealed that in HPV-positive disease, there were no differences by sex after accounting for the false discovery rate (FDR). In HPV-negative tumors, BRWD3 mutations occurred more frequently in the tumors of female patients compared to males after adjusting for the FDR (p = 0.02). Further, HPV-negative BRWD3 mutant tumors were found to have significantly worse 5-year overall survival compared to wildtype on multivariate analysis (p = 0.02). There were 88 heterozygous deletions and 14 amplifications that were differentially altered between male and female HPV-negative tumors and associated with expression changes. Pathway analysis of these genes revealed that tumors from males were enriched in five pathways including chemokine and phosphophatidylinositol signaling. Conclusions Reanalysis of the TCGA HNSCC dataset stratified by sex revealed that males in this cohort had a significant survival advantage, due to a higher proportion of HPV-positive disease. Mutations in BRWD3 were more frequent in HPV-negative tumors of females and were associated with poorer overall survival. BRWD3 may represent a novel biomarker of patient outcomes, but will require additional validation.

Background Oxidative stress is defined as an imbalance between the level of reactive oxygen species and antioxidant mechanisms. Compared with asthma, the role of oxidative stress in allergic rhinitis (AR) has received little attention. Objective To investigate the association between overall systemic oxidative stress and AR. Methods We used a propensity score matching case-control study and selected 90 children who had experienced AR in the previous year. This AR group was then matched with 90 healthy children who comprised the control group. Propensity score matching, a statistical matching technique that accounts for the conditional probability of receiving an exposure given a vector of measured covariates, is used to reduce selection bias and potential confounders in observational study. Serum total antioxidant status (TAS) and total oxidant status (TOS) levels were determined using a commercially available assay kit. Medical records and personal information were also reviewed. Results No statistically significant differences were found between patients with regard to age, sex, height, weight, educational level of parent, monthly household income, or distance of home from a main road. The mean TAS and TOS levels in the patient group were significantly higher than those of the control group ( P = .03 and .048, respectively). The oxidative stress index, which is defined as the ratio of TOS to TAS, also increased in the AR group with statistical propensity ( P = .08). In a multivariate logistic analysis, only TAS and TOS levels were significantly associated with increased risk of allergic rhinitis. Conclusion Patients with AR have systemically elevated oxidative stress and systemically elevated TAS levels.

Objectives: PI3K/Akt/mTOR pathway is commonly activated in most cancers and is correlated with resistance to anticancer therapies such as radiotherapy. Therefore, PI3K is an attractive target for treating PI3K-associated cancers. Material and Methods: We investigated the basal expression and the expression after treatment of PI3K inhibitor or Src inhibitor of PI3K/Akt pathway-related proteins in AMC-HN3, AMC-HN3R, HN30 and HN31 cells by performing immunoblotting analysis. The sensitivity to PI3K inhibitors or Src inhibitor was analyzed by MTT assay and clonogenic assay. To determine the antitumoral activity of combination treatment with PI3K inhibitor and Src inhibitor, we used using xenograft mouse model. Results: We found that PI3K regulatory subunit p85 was predominantly phosphorylated in radioresistant head and neck cancer cell line (HN31), which showed resistance to PI3K inhibitors. Next, we investigated mechanism through which PI3K p85 phosphorylation modulated response to PI3K inhibitors. Of note, constitutive activation of Src was found in HN31 cells and upon PI3K inhibitor treatment, restoration of p-Src was occurred. Src inhibitor improved the efficacy of PI3K inhibitor treatment and suppressed the reactivation of both Src and PI3K p85 in HN31 cells. Furthermore, downregulation of PI3K p85 expression by using a specific siRNA suppressed Src phosphorylation. Conclusions: Together, our results imply the novel role of the PI3K regulatory subunit p85 in the development of resistance to PI3K inhibitors and suggest the presence of a regulatory loop between PI3K p85 and Src in radioresistant head and neck cancers with constitutively active PI3K/Akt pathway.

The development of biomarkers for the prediction of lymph node metastasis and prognosis is critical for deciding the treatment modality of tongue cancer. The purpose of our study is to investigate the clinical implications of epithelial-mesenchymal transition (EMT) expression in tongue cancer.Historical cohort studyTertiary-care hospital.The study included 95 subjects with tongue cancer who underwent wide excision and neck dissection. According to characteristics of immunohistochemical staining for E-cadherin and vimentin, we classified the tumors as complete EMT phenotype, incomplete EMT phenotype, or epithelial phenotype. The correlation between risk factors and nodal metastasis was assessed, and disease-free survival (DFS) was analyzed.Positive lymph nodes were detected in 46 (48.4%) patients and was found to correlate significantly with depth of invasion ≥ 4 mm and EMT expression on multivariate analysis (P = .030, P = .022, respectively). The mean follow-up period of all patients was 96.3 months (range, 6-149 months). Overall 5-year DFS was 61.7%. On multivariate analysis, the only factors affecting DFS were nodal stage and EMT expression (P = .033, P = .021, respectively).Our study reveals that EMT expression is a significant biomarker for predicting lymph node metastasis and tumor recurrence in tongue cancer. Evaluation of EMT expression in tongue cancer can allow therapy to be offered accordingly.

Background We investigated whether the addition of narrow band imaging (NBI) to standard diagnostic workups could enhance the detection of primary lesions in patients with carcinoma of unknown primary (CUP). Methods Thirty patients with CUP underwent NBI endoscopy and fluorodeoxyglucose–positron emission tomography/CT (FDG-PET/CT) after thorough conventional diagnostic workups between 2009 and 2011. Sites suspected of harboring primary tumors, as determined by NBI and/or FDG-PET/CT, were biopsied for histologic confirmation. Results Occult primary tumors were identified in 33.3% (10/30), including 13.3% (4/30) by NBI and 20.0% (6/30) by FDG-PET/CT. All of diagnosed lesions by NBI were confirmed histologically as squamous cell carcinomas with T1 classification and identified at 2 supraglottis, 1 hypopharynx, and 1 esophagus, respectively. Conclusions NBI endoscopy may be a useful method for detecting primary tumors, especially for small and superficial squamous cell carcinomas of the upper aerodigestive tract, after conventional workup in patients with CUP. © 2012 Wiley Periodicals, Inc. Head Neck, 2013

Background and Objectives Little is known about lymph node metastasis and the extent of neck dissection (ND) in patients with submandibular gland (SMG) carcinoma. We therefore evaluated the metastatic topography of neck lymph nodes in patients with SMG carcinoma and the influence of metastases on tumor recurrence and patient survival. Methods The pattern of lymph node spread was analyzed in 64 patients with SMG carcinoma treated from January 1994 to January 2009. Disease-free survival (DFS), overall survival (OS), and distant metastasis-free survival (DMFS) were calculated, and the clinicopathological factors associated with each were analyzed. Results Positive pathological lymph nodes were detected in 31 (48.4%) patients and was found to correlate significantly with histologic grade (P

Background To determine whether 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) could serve as a useful technique predicting tumor hypoxia and prognosis in tongue cancer, we assessed the relationship between FDG uptake and the levels of hypoxia-related markers. Methods Tumor uptake of FDG in 33 patients with T2 tongue cancer was assessed by measuring maximum standardized uptake values (SUVmax). Expression of hypoxia-inducible factor (HIF)-1α, carbonic anhydrase (CA)-9, glucose transporter (GLUT)-1, and erythropoietin receptor (EPOR), was determined by immunohistochemical staining. Correlation between SUVmax and the expression of hypoxia-related markers was assessed and multivariate analysis was performed to determine what parameters affected clinical outcomes. Results We observed strong correlations between SUVmax and expression of HIF-1α (p < .05), CA-9 (p < .01), and GLUT-1 (p < .01). SUVmax, HIF-1α expression, and tumor grade were significant independent predictors of disease-free survival (DFS). Conclusion SUVmax may be a good noninvasive biomarker for prediction of hypoxic status and prognosis of patients with T2 tongue cancer. © 2011 Wiley Periodicals, Inc. Head Neck, 2011

Induction chemotherapy (ICT) may reduce rates of distant metastases and enhance organ preservation and survival rates in patients with hypopharyngeal cancer. The authors compared survival data in patients who underwent chemoradiotherapy or surgery after ICT and investigated whether response to ICT is a predictive marker for outcome in patients with hypopharyngeal cancer.Historical cohort study.Tertiary-care hospital.The authors enrolled 97 patients (89 men, 8 women; mean age 61.2 years; range, 29-80 years) with previously untreated hypopharyngeal cancer who underwent ICT between January 1997 and December 2006 at Asan Medical Center. Disease-free survival (DFS), overall survival (OS), and laryngectomy-free survival (LFS) were analyzed.At a mean follow-up of 38.0 months, the 3-year DFS and OS for all patients were 48.3% and 49.2%, respectively. The 3-year LFS rate of patients who underwent nonsurgical therapy (n = 85) after ICT was 48.0%. Only response to ICT was associated with DFS (P = .047), OS (P = .003), and LFS (P = .009) in multivariate analysis. When the authors compared survival data in patients who underwent surgical and nonsurgical treatments after ICT, they found that there was no statistical difference in terms of the 3-year DFS in partial response (42.9% vs 50.5%, P = .77) and nonresponse groups (50.0% vs 0%, P = .43) between the 2 treatment types.ICT permits assessment of tumor responsiveness and alters subsequent therapy accordingly. Response to ICT may be useful in the prediction of ultimate outcomes and organ conservation in patients with hypopharyngeal cancer.

Lymph node metastases occur frequently in patients with papillary thyroid carcinoma (PTC), and the central compartment of the neck is the most frequently involved site. Some authors advocate prophylactic central neck dissection (CND) during total thyroidectomy. However, little is known about the effects of prophylactic unilateral CND in papillary thyroid microcarcinoma (PTMC) patients who undergo hemithyroidectomy. This study was designed to investigate the impact of prophylactic unilateral CND in this population.The clinical records of 152 patients with a PTMC ≤1 cm according to preoperative ultrasonography who underwent hemithyroidectomy between 2002 and 2009 were assessed retrospectively. Outcomes were compared between the 65 (43%) patients who underwent hemithyroidectomy with elective unilateral CND (CND+ group) and the 87 (57%) patients who underwent hemithyroidectomy only (CND- group).In the CND- group, 37 patients (43%) had microscopic extrathyroidal extension (ETE). In the CND+ group, 33 patients (50.7%) had ETEs or nodal metastases. During follow-up, recurrence was observed in 14 patients (n = 1, CND+ group; n = 13, CND- group). Prophylactic unilateral CND was associated with a significantly lower rate of locoregional recurrence (P = 0.017).Compared with hemithyroidectomy alone, prophylactic unilateral CND may decrease the rate of locoregional recurrence in patients with PTMC.

In temporal lobe epilepsy (TLE) there may be functional abnormalities or structural lesions that can manifest as a central auditory processing disorder, which is defined as a disorder in the recognition, discrimination, ordering, grouping, and localization of sounds, with emphasis on the processing of nonspeech sounds. We performed frequency pattern, duration pattern, and dichotic tests in 28 patients with TLE with normal hearing on pure tone audiometry. The scores on the frequency pattern, duration pattern, and dichotic tests were abnormal in 78.6, 57.1, and 20.6% of patients, respectively, with no significant differences with the laterality of TLE. Patients with hippocampal sclerosis performed significantly worse than patients with normal MRI findings in frequency tests. Longer duration of epilepsy is negatively correlated with both the duration pattern and dichotic tests (P

P53 is an important biomarker in response to genotoxic stress, but it is also known to plays a key role in the regulation of metabolic homeostasis. The loss of p53 is a well-established contributor to the malignant transformation and glycolytic phenotype acquisition of cells during cancer development. However, the role of p53 in genotoxic therapy-induced metabolic shift in cancers remains unclear. Here, we attempted to elucidate how p53 participates in the glycolytic shift of head and neck cancer cell lines following irradiation. We established a stable radioresistant head and neck cancer cells (HN30-R; p53 wild type and UMSCC1-R; p53 null type) through cumulative irradiation and then analyzed their glucose metabolic profiles and mitochondria respiration. As a result, the metabolic analysis revealed no changes glycolysis of HN30-R cells, but UMSCC1-R cells exhibited increased glycolysis through increased glucose uptake and lactate production and glycolytic intermediates as well as related glycolytic enzymes, compared to UMSCC1 cells. Also, we confirmed that the mitochondrial respiration was reduced by the maximal respiration parameters of oxygen consumption rate (OCR) and that abnormal mitochondria were accumulated by electron microscopy in UMSCC1-R cells. Thus, UMSCC1-R cells exhibited an increased sensitivity to glycolysis-targeting drugs such a hexokinases inhibitor (2-deoxy-D-glucoes; 2-DG) and a lactate dehydrogenase-A inhibitor (AT101), but HN30-R cells did not shown any changes. Moreover, we identified that mitophagy limits glycolytic shift through the p53-dependent clearance of abnormal mitochondria. Taken together, these results suggest that p53 null type cells increased aerobic glycolysis to overcome the accumulation of abnormal mitochondria in radioresistnat cells. Conversely, p53 wild type cells inhibited the glycolytic shift by regulating a integrity through p53-dependent mitophagy. Thus, glycolysis-targeted drugs could be an alternative strategy for overcoming recurrent cancers after radiotherapy, and p53 status could be a biomarker for selecting participants for clinical trials. Citation Format: Hyo Won Chang, Ji Won Kim, Mi Ra Kim, Hae Yun Nam, Myungjin Lee, Won Hyeok Lee, Song Hee Kim, Da Seul Seong, Myung Woul Han, Jong Cheol Lee, Jung Je Park, Ji-hyun Seo, Seong Who Kim, Sang Yoon Kim. P53-dependent mitophagy controls glycolytic shift in radioresistant head and neck cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2405.

J Oral Pathol Med (2010) 39: 722–727 Background: Zinc is known to play an important role for growth and development, the immune response, neurological function, and reproduction. Although the etiology of burning mouth syndrome (BMS) is unknown, zinc deficiency may be implicated in the pathogenesis of BMS. The aim of this study was to demonstrate a causal relationship between zinc deficiency and BMS and to assess whether zinc replacement is an effective therapy for BMS. Methods: Serum zinc level was evaluated in 276 patients with BMS. To assess the therapeutic effect of zinc replacement, patients with zinc deficiency were administered a zinc supplement (14.1 mg/day). Pain intensity 6 months after zinc replacement was evaluated using an 11-point numerical scale. We also developed an animal model of zinc deficiency to assess the effects of zinc deficiency on the oral mucosa. Results: Of the 276 patients with BMS, 74 (26.8%) had low serum zinc levels. Zinc replacement therapy lowered the mean numerical pain scale in these patients from 8.1 to 4.1, compared with a mean decrease from 7.7 to 6.7 in a control group (P = 0.004). In our animal model of zinc deficiency, the main pathologic findings were hyperkeratinization and increased mitosis on the dorsum of the tongue, although there were no gross oral mucosal lesions. Conclusions: Zinc deficiency might play a role in some patients with BMS. In such patients, appropriate zinc replacement therapy is effective in relieving symptoms.

Background Diabetes mellitus is a risk factor for sudden sensorineural hearing loss (SSNHL), possibly as a result of microvascular damage, increased blood viscosity and embolic and thrombotic episodes. Aim To perform a prospective, randomized clinical trial to determine the therapeutic effect of lipo-prostaglandin E1 (lipo-PGE1) on SSNHL in Korean patients with Type 2 diabetes. Methods The study group consisted of 270 consecutive Korean patients (130 male, 140 female) in whom SSNHL was diagnosed. Patients were classified as diabetic or non-diabetic by the new American Diabetes Association criteria. With the approval of the institute ethics committee, patients were randomly assigned to treatment with of 10 µg lipo-PGE1 (lipo-PGE1 group) given as a continuous infusion over 5 days, or saline (placebo group). In addition, all patients studied were treated with 48 mg methylprednisolone for 5 days. Results The overall recovery rates after treatment were 51.5% in diabetic and 64.2% in non-diabetic patients. In diabetic patients, there was a significantly higher rate of hearing improvement in the lipo-PGE1 group (64.7%) compared with the placebo group (37.5%), whereas, in non-diabetic patients, there was no significant difference in rate of hearing improvement between the lipo-PGE1 group (70.3%) and the placebo group (58.3%). Conclusion Lipo-PGE1 may have beneficial effects in the treatment of SSNHL in Korean patients with Type 2 diabetes.

Activation of the PI3K pathway is commonly observed and is correlated with tumor development, progression, poor prognosis, and resistance to cancer therapies, such as radiotherapy, in most cancers. As a central node of this pathway, PI3K is an attractive target for PI3K-addicted cancer therapy and PI3K inhibitors may thus restore sensitivity to other treatments when administered as part of combination regimens. Here, we found that PI3K/p85 was expressed predominantly in the radioresistant head and neck cancer cell line (HN31 cell line). And then, we investigated whether PI3K modulation was crucial for the development of novel treatment strategies for radioresistant cancer cell line. Interestingly, we found that head and neck cancer cell lines with PI3K/p85 activation showed the resistance to PI3K inhibitors and the resistance mechanism was associated with Src activation which is a member of a superfamily of membrane-associated nonreceptor protein tyrosine kinases. Src inhibitor improves the efficacy of PI3K inhibitor treatment through suppression of Src and PI3K/p85 activation in HN31 cell line. Collectively, our study highlights the role of p85 and Src activation in the resistance for PI3K inhibition and the potential clinical application of combination regimens of Src and PI3K inhibitors in head and neck cancers. This is the first investigation to analyze the role of Src in resistance to the PI3K inhibitors of head and neck cancer. As a consequence, a greater understanding of resistance mechanisms through our results will enable the rational design of combination regimens and sequential treatment algorithms to improve clinical outcomes. Citation Format: Gui Chul Kim, Hae Yun Nam, Hyang Ju Lee, Min Kyung Kim, Geun Hee Lee, Myung Woul Han, Seong Who KIM, Sang Yoon Kim. Src leads to a novel mechanism of resistance to PI3K inhibitors through regulation of PI3K/p85 activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 144. doi:10.1158/1538-7445.AM2017-144

The presence of p53 mutation was associated with poor survival in various tumors. The involvement of p53 in apoptosis and cell-cycle control makes it a plausible biomarker of prognosis . Classifying TP53 mutations in HNSCC described disruptive TP53 mutation in either the L2 or L3 loop of the DNA binding domain, resulting in polarity change within the protein, or stop cordon. Disruptive TP53 mutation in HNSCC tumors predicts for locoregional recurrence, due to increased radioresistance via the inhibition of senescence. Senescence induction contributes to cancer therapy responses and is crucial for p53-mediated tumor suppression. However, whether p53 inactivation actively suppresses senescence induction has been unclear. Here, we found that overexpression CIP2A (cancerous inhibitor of protein phosphatase 2A) positively correlated with presence of p53 mutation in head and neck cancer and mediates radioresistance through suppression of radiation induced senescence. And we demonstrated that rapamycin could induce senescence via CIP2A downregulation and increase radiosensitivity in p53 disruptive mutation cell line. This is the first investigation to analyze the role of CI2A in resistance to the radiotherapy of head and neck cancer. As a consequence, a greater understanding of radioresistance mechanisms through our results in head and neck cancer with p53 mutation will enable the rational design of combination regimens and sequential treatment algorithms to improve clinical outcomes and points to the usefulness of CIP2A as a biomarker to predict clinical response to rapamycin in head and neck cancer. Citation Format: Song Hee Kim, Won hyeok Lee, Myung Jin Lee, Hyo Won Chang, Ji Won Kim, Mi Ra Kim, Jung Je Park, Myung Woul Han, Sang Yoon Kim. CIP2A can be a therapeutic target of rapamycin in radioresistant head and neck cancer with P53 mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5476. doi:10.1158/1538-7445.AM2017-5476

Objective Salivary duct carcinoma (SDC) is highly aggressive, with high rates of recurrence and nodal and distant metastases. The aim of the current study was to evaluate the clinical implication of EGFR and HER2 expression for predicting prognosis and to identify the factors associated with outcome. Methods The medical records of 28 patients with SDC underwent surgery and adjuvant RT. Expression of c-erbB-2 and EGFR was determined immunohistochemically on the 25 SDC specimens. Disease-free survival (DFS), overall survival (OS) and distant metastasis-free survival (DMFS) were analyzed. Results Three-year DFS, OS and DMFS rates were 38.3%, 78.1% and 45.7%, respectively. Expression of c-erbB-2 and EGFR was seen in 64% and 40%. c-erbB-2 and EGFR expression did not correlate with recurrence or metastasis. Advanced N classification and perineural invasion (PNI) were significant predictors of DFS and DMFS. Conclusion c-erbB-2 and EGFR expression did not correlate with recurrence or metastasis. Despite aggressive surgery and RT, approximately 50% of SDCs failed systemically. More effective therapy to inhibit distant metastases in patients with advanced N classification and PNI should be considered.

Autophagy is frequently activated in radioresistant cancer cells. In the present study, we evaluated the role of autophagy and transforming growth factor-activated kinase 1 (TAK1) in radioresistance.TAK1 phosphorylation in MDA-MB231 breast cancer cells was evaluated by western blotting. The regulatory effects of the TAK1 inhibitor and autophagy inhibitor were assessed by cell morphology, cell survival and induction of apoptosis.Radiation induced the phosphorylation of TAK1, whereas the inhibition of TAK1 activity enhanced the cytotoxicity of radiation in MDA-MB231 cells. Autophagy inhibitors significantly enhanced radiation-induced apoptosis of MDA-MB231 cells. This augmentation in radiosensitivity seemed to result from the suppression of TAK1 activation.Inhibition of autophagy enhanced radiosensitivity through suppression of radiation-induced TAK1 activation, suggesting that the modulation of TAK1-induced autophagy may be a good therapeutic strategy to treat radioresistant breast cancer.

There are limited therapeutic options for patients with recurrent head and neck cancer after radiation therapy failure. To assess the use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as a salvage chemotherapeutic agent for recurrent cancer after radiation failure, we investigated the effect of clinically relevant cumulative irradiation on TRAIL-induced apoptosis.Using a previously established HN3 cell line from a laryngeal carcinoma patient, we generated a chronically irradiated HN3R isogenic cell line. Viability and apoptosis in HN3 and HN3R cells treated with TRAIL were analyzed with MTS and PI/annexin V-FITC assays. Western blotting and flow cytometry were used to determine the underlying mechanism of TRAIL resistance. DR4 expression was semiquantitatively scored in a tissue microarray with 107 laryngeal cancer specimens. Methylation-specific polymerase chain reaction and bisulfite sequencing for DR4 were performed for genomic DNA isolated from each cell line.HN3R cells were more resistant than HN3 cells to TRAIL-induced apoptosis because of significantly reduced levels of the DR4 receptor. The DR4 staining score in 37 salvage surgical specimens after radiation failure was lower in 70 surgical specimens without radiation treatment (3.03 ± 2.75 vs 5.46 ± 3.30, respectively; P.001). HN3R cells had a methylated DR4 CpG island that was partially demethylated by the DNA demethylating agent 5-aza-2'-deoxycytidine.Epigenetic silencing of the TRAIL receptor by hypermethylation of a DR4 CpG island might be an underlying mechanism for TRAIL resistance in recurrent laryngeal carcinoma treated with radiation.

Autophagy is frequently activated in radioresistant cancer cells where it provides a cell survival strategy. The mTOR inhibitor rapamycin activates autophagy but paradoxically it also enhances radiosensitivity. In this study, we investigated the mechanisms of these opposing actions in radiation-resistant glioma or parotid carcinoma cells. Radiation treatment transiently enhanced autophagic flux for a period of 72 hours in these cells and treatment with rapamycin or the mTOR inhibitor PP242 potentiated this effect. However, these treatments also increased heterochromatin formation, irreversible growth arrest, and premature senescence, as defined by expression of senescence-associated β-galactosidase activity. This augmentation in radiosensitivity seemed to result from a restoration in the activity of the tumor suppressor RB and a suppression of RB-mediated E2F target genes. In tumor xenografts, we showed that administering rapamycin delayed tumor regrowth after irradiation and increased senescence-associated β-galactosidase staining in the tumor. Our findings suggest that a potent and persistent activation of autophagy by mTOR inhibitors, even in cancer cells where autophagy is occurring, can trigger premature senescence as a method to restore radiosensitivity. Cancer Res; 73(14); 4267–77. ©2013 AACR.

Computed tomography (CT) imaging has clear limitations for the diagnosis of cartilage invasion or tumor spread in recurrent laryngeal cancer. Alternative methods of pretreatment assessment are needed for recurrent laryngeal cancer.The diagnosis and staging of recurrent laryngeal cancer, previously treated by radiation therapy (RT), remains challenging. Practically, surgeons need to depend on imaging to predict which patients will have a chance for conservation salvage laryngectomy. The purpose of the present study was to determine the accuracy of preoperative CT performed for recurrent laryngeal carcinoma evaluation following RT.This retrospective review identified 32 patients who underwent salvage total laryngectomy after RT from 1998 to 2010. For our radiologic classification of the thyroid cartilage, we analyzed the conditions as normal, sclerosis, invasion, penetration, and extralaryngeal spread and categorized the state of the arytenoids and cricoid into three possible conditions: normal, sclerosis, and destruction. Radiographic findings were correlated with pathology findings.Sensitivity and specificity for the detection of the thyroid cartilage infiltration were 57% and 94%, 50% and 89% for the cricoid cartilage, and 33% and 76% for arytenoid cartilage, respectively. The accuracy of recurrent tumor classification was 59.4%. Three carcinomas were over-staged and 10 were under-staged.

Radiotherapy is a well-established therapeutic modality used in treatment of many cancers. However, radioresistance remains a serious obstacle to successful treatment. Radioresistance can cause local recurrence and distant metastases in some patients after treatment by radiation. Thus, special emphasis has been given to the discovery of effective radiosensitizers. EphA3 receptors functions contribute to tumor development, modulating cell-cell adhesion, invasion, neo-angiogenesis, tumor growth and metastasis. However, the role of EphA3 in radioresistance remains to be elucidated. Here, we established the stable radioresistant head and neck cancer cell line (AMC HN3R cell line) and identified that EphA3 was overexpressed predominantly in the AMC HN3R cancer cell line through DNA microarray, real time PCR and Western blotting. Additionally, we identified that EphA3 was overexpressed in recurred laryngeal cancer specimen after radiation therapy. And we found that EphA3 mediated the tumor invasiveness and migration and EMT (epithelial mesenchymal transition) related protein expression in AMC HN3R cancer cell line. To investigate the role of EphA3 in modulating the radiosensitivity, we observed the change of survival fraction after transfection EphA3 siRNA. And we found that inhibition of EphA3 enhances radiosensitivity in AMC HN 3R cell line. In conclusion, these results suggest that EphA3 is overexpressed in radioresistant head and neck cancer and can play a crucial role in development radioresistance in head and neck cancers through regulation of EMT pathway. Citation Format: Myung Woul Han, Song Hee Kim, Hyo Won Chang, Hae Yun Nam, Myungjin Lee, Gui Chul Kim, Yoon sun Lee, Mi Ra Kim. EphA3 maintains radioresistance in head and neck cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1170.

p16 immunohistochemistry (IHC) status correlated with less exposure to smoking and/or alcohol in Korean patients with locally advanced tonsillar squamous cell carcinoma (TSCC), and was an independent prognostic factor for survival.TSCC is more likely to be human papillomavirus (HPV)-positive than other head and neck squamous cell carcinoma (HNSCC) subtypes. The objective of this study was to ascertain the HPV status of TSCC in Korean patients and to determine its relationship with clinical parameters and prognosis.The locally advanced TSCCs of 79 patients who were treated between 2000 and 2008 were tested by p16 IHC and HPV in situ hybridization (ISH) with a tissue microarray.Sixty-three patients (80%) were positive for p16 IHC, while 54 (68%) were positive by HPV ISH. p16 IHC status correlated significantly with lower exposure to smoking and alcohol (p0.05) but did not correlate with T and N stage classification, histological differentiation, age, or gender. The p16-positive group had a significantly higher 5-year overall survival rate in comparison with the p16-negative group (78% vs 63%, hazard ratio (HR) = 0.347, 95% CI = 0.14, 95% Cp = 0.025). p16 IHC was a favorable independent prognostic factor for overall survival, even after adjustment for age and T stage (HR = 0.283, 95% CI = 0.103, 95% p = 0.015).

Our aim was to compare the diagnostic performance of shear wave elastography (SWE) with that of gray-scale ultrasound (US) in differentiating metastatic from benign lymph nodes in patients with head and neck malignancies. Maximum shear elasticity modulus (maxSM) was measured on SWE. The reference standard was pathologic diagnosis after surgery. We examined 67 lymph nodes (34 metastatic, 33 benign) from 15 patients (8 men and 7 women; mean age, 54.2 years). The maxSM value was significantly higher for metastatic than benign lymph nodes (41.06 ± 36.34 kPa vs. 14.22 ± 4.19 kPa, p < 0.0001) at a cutoff level of 19.44 kPa. Accuracy, sensitivity and specificity were 94, 91 and 97%, respectively, for SWE, and 91, 88 and 94%, respectively, for gray-scale US. Multiple regression analysis showed that the maxSM value (r = 0.882) and gray-scale US criteria (r = 0.837) were independent variables. SWE may be a valuable quantitative reproducible method for characterizing cervical lymph nodes.

To investigate the long-term clinical efficacy and stability of thyroplasty type I for unilateral vocal cord palsy, and to identify the appropriate timing of posttreatment evaluations for determination of long-term voice outcome. StudySingle-institution retrospective study.Academic tertiary referral centers in Korea.Forty patients with unilateral vocal cord palsy who underwent thyroplasty from January 1, 1996, through December 31, 2006, and were followed up for at least 5 years after the surgical procedure.Thyroplasty type I under local anesthesia.Acoustic and aerodynamic analyses of voice were performed on the day before the operation and at preset intervals afterward. Two blinded speech-language pathologists performed the perceptual evaluation.The GRBAS scale (grade of hoarseness, roughness, breathiness, asthenia, and strain) values showed significant improvement at 6 months after the operation (P .05); these improvements continued up to 1 year and were maintained 5 years after the operation. Acoustic measurements of shimmer and jitter began to show significant improvement at 6 months after the operation, and fundamental frequency and noise harmonic ratios evidenced significant improvement at 1 year (P .05); these improvements were maintained, to a significant extent, at 5 years after the operation. Aerodynamically, the maximum phonation time, glottal flow rate, and peak subglottic pressure improved significantly from before the operation to 6 months and 1 year after the operation, attaining near-normal values at 1 year afterward (P . 05)Thyroplasty type I may provide evidence that voice outcome progressively evolves during the first years after the surgical procedure, and that subsequent vocal improvement presented long-lasting stabilization. To assess the long-term voice quality, it may be enough to perform the voice evaluation at 1 year after the procedure.

The issue of whether aberrant expression of β1-integrin is associated with cancer progression and development of resistance to cytotoxic therapy is of considerable interest. Studies to date have shown that the anchorage-independent survival of cancer is attributed, in part, to epithelial-to-mesenchymal transition (EMT). Here, we have reported a novel alternative mechanism of anchorage-independent survival of cancer cells. Cell lines derived from head and neck cancer patients (AMC-HN-3 and AMC-HN-9) and the well-known EMT cancer cell line, MDA-MB231, were examined. The EMT features of AMC-HN-9 cells were comparable to those of MDA-MB231, whereas AMC-HN-3 cells showed no EMT characteristics. Although the pattern and degree of β1-integrin expression were similar in all three cell lines, sensitivities of the cells to β1-integrin knockdown with small interfering RNA (siRNA) were different. Cancer cells with no EMT features underwent cell death to a more significant extent following β1-integrin silencing than those with EMT. Intriguingly, we observed reactive activation of the p53–p21 pathway after β1-integrin silencing in AMC-HN-9 cells lacking an apparent cell death response. Simultaneous knockdown of wild-type p53 and β1-integrin in this cell line promoted cell death. Our data collectively indicate that β1-integrin-related cell death is closely associated with EMT phenotypes and activation of the p53–p21 pathway is partly involved in the acquisition of resistance to apoptosis induced by β1-integrin silencing. Further clarification of the mechanisms underlying p53 integration with β1-integrin signaling may facilitate the development of novel anti-cancer strategies.