Inhibition of endocytic uptake of severe acute respiratory syndrome coronavirus 2 and endo-lysosomal acidification by diphenoxylate.

Cell culture-based screening of a chemical library identified diphenoxylate as an antiviral agent against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The observed 50% effective concentrations ranged between 1.4 and 4.9 µM against the original wild-type strain and its variants. Time-of-addition experiments indicated that diphenoxylate is an entry blocker targeting a host factor involved in viral infection. Fluorescence microscopic analysis visualized that diphenoxylate prevented SARS-CoV-2 particles from penetrating the cell membrane and also impaired endo-lysosomal acidification. Diphenoxylate exhibited a synergistic inhibitory effect on SARS-CoV-2 infection in human lung epithelial Calu-3 cells when combined with a transmembrane serine protease 2 (TMPRSS2) inhibitor, nafamostat. This synergy suggested that efficient antiviral activity is achieved by blocking both TMPRSS2-mediated early and endosome-mediated late SARS-CoV-2 entry pathways. The antiviral efficacy of diphenoxylate against SARS-CoV-2 was reproducible in a human tonsil organoids system. In a transgenic mouse model expressing the obligate SARS-CoV-2 receptor, human angiotensin-converting enzyme 2, intranasal administration of diphenoxylate (10 mg/kg/day) significantly reduced the viral RNA copy number in the lungs by 70% on day 3. This study underscores that diphenoxylate represents a promising core scaffold, warranting further exploration for chemical modifications aimed at developing a new class of clinically effective antiviral drugs against SARS-CoV-2.

Single clonal glandular stem cells derived from human parotid glands do not attain malignant phenotype during long-term in vitro culture.

Mesenchymal stem cells (MSCs) are being intensively investigated as future therapeutics for various human diseases. One of the most important challenges to the clinical application of MSCs is the possibility of malignant transformation during long-term in vitro culturing. However, there have been no reports on the tumorigenicity of salivary gland-derived MSCs following long-term in vitro culturing. Here, we isolated a single clonal glandular stem cells from human parotid gland stem cells (hpGSCs) using a modified sub-fractionation culturing method. The possibility of malignant transformation of these cells following long-term culturing was evaluated under in vitro and in vivo culture conditions. Single clonal glandular stem cells from the human parotid gland have unique multipotent MSCs traits. hpGSCs at passage 18 stained strongly for ß-galactosidase expression and the long-term culture of hpGSCs led to a reduction in telomerase activity. hpGSCs could not survive in a soft agar environment and did not cause tumor formation in a xenograft mouse model. In addition, the expression of salivary cancer-related oncogenes was not elevated in hpGSCs following the long-term culture. In conclusion, we demonstrated that there is no possibility of acquiring a malignant transformation during long-term in vitro cell expansion of hpGSCs.

Is Postoperative Adjuvant Radioactive Iodine Ablation Therapy Always Necessary for Intermediate-Risk Papillary Thyroid Cancer Patients With Central Neck Metastasis?

BACKGROUND: Papillary thyroid cancer (PTC) is commonly associated with neck lymph node metastasis (LNM), and recurrence does occur after radioactive iodine (RAI) ablation therapy. This study aimed to analyze the effectiveness of RAI ablation with regard to disease recurrence in intermediate-risk PTC patients with neck LNM. In addition, the study identified possible predisposing risk factors that might benefit from RAI ablation and analyzed common RAI therapy complications among these patients. METHODS: A retrospective analysis of 349 intermediate-risk PTC patients with neck LNM who underwent thyroidectomy with neck dissection was performed. The oncologic results and clinicopathologic characteristics of these patients together with the incidence of postoperative RAI therapy complications were evaluated. RESULTS: Of the 349 patients, disease recurrence after treatment occurred for 27 patients (8%) during a mean follow-up period of 58.7 months (range 7-133 months). The recurrence-free survival curve of the patients who received postoperative RAI therapy (n = 208) did not differ significantly from that of the patients who did not receive it (n = 141) (P = 0.567). Nine patients without adjuvant RAI therapy (6%, 9/141) had recurrence. The recurrence rate for the central LNM patients without RAI therapy was only 2% (2/106). Both of these patients with recurrence had pathologic extranodal spread (ENS) and a high number (> 5) of metastatic central LNs. Postoperative RAI-related complications were observed in 24 patients (12%). CONCLUSIONS: Postoperative RAI is not necessary for intermediate-risk papillary thyroid cancer patients with central LNM, especially for patients with negative ENS and low number (< 5) of metastatic lymph nodes.

Association between obstructive sleep apnea and thyroid cancer incidence: a national health insurance data study.

PURPOSE: Little is known about the incidence of thyroid cancer in patients with obstructive sleep apnea (OSA). This study aimed to evaluate whether OSA is associated with the incidence of thyroid cancer based on the Korea National Health Insurance Service (KNHIS) database. METHODS: This study was designed as a retrospective cohort data analysis of the KNHIS dataset. A total of 198,574 patients who were over 20 years of age and had been newly diagnosed with OSA between 2007 and 2014 were enrolled. A control group of 992,870 individuals was selected based on propensity score matching by age and sex. The mean follow-up duration was 4.5 ± 2.3 years. The primary endpoint was the incidence of newly diagnosed thyroid cancer. RESULTS: The hazard ratio (HR) for thyroid cancer incidence among OSA patients compared to the control was 1.72 (95% confidence interval [CI] 1.60-1.84) based on Model 1 (not adjusted by any covariate) and 1.64 (95% CI 1.53-1.76) based on Model 2 (adjusted by income level, diabetes, hypertension, and dyslipidemia). Thyroid cancer incidence was significantly higher in male patients (HR = 1.93, 95% CI 1.74-2.12) than female ones (HR = 1.39, 95% CI 1.26-1.54). When compared by age, the HR of thyroid cancer was higher in middle-aged (40 ≤ age < 65 years) patients (HR = 1.68, 95% CI 1.55-1.83) than in young (20 ≤ age < 40 years, HR = 1.53, 95% CI 1.32-1.77) or old (65 ≤ age, HR = 1.28, 95% CI 0.94-1.74) patients. CONCLUSION: OSA may increase the risk of developing thyroid cancer, especially in middle-aged men.

Inhibitor of DNA Binding 2 (ID2): A Novel Marker for Lymph Node Metastasis in Head and Neck Squamous Cell Carcinoma.

BACKGROUND: Although aggressive invasion and sequential lymph node metastasis (LNM) significantly affect the prognosis of patients with head and neck squamous cell carcinoma (HNSCC), studies on identifying the factors that regulate this process remain scarce. This study found an inhibitor of DNA binding 2 (ID2) as a novel molecule involved in the regulation of invasion and LNM of HNSCC and further verified its functional role. METHODS: The study examined the translational significance between ID2 expression levels and the presence of LNM as well as the prognosis for 119 patients with HNSCC after treatment. In addition, in vitro and in vivo experiments were performed using ID2 gene-modulated HNSCC cell lines to determine the functional role of ID2 in the invasion and LNM of HNSCC. RESULTS: Elevated levels of ID2 expression were closely associated with the presence of LNM in 119 patients with HNSCC, resulting in a poor prognosis. Overexpression of ID2-induced invasion and LNM of HNSCC cells was observed in vitro and in vivo. By contrast, knockdown of the ID2 gene diminished invasion and LNM of HNSCC cells. In addition, the ID2 expression level increased the expression level of matrix metalloproteinase 1 (MMP1), a molecule downstream to ID2. Furthermore, silencing of MMP1 in ID2-overexpressed HNSCC cells rescued the elevated invasion and LNM capabilities of these cells, suggesting that ID2 enhances invasion and LNM partly via MMP1 activation. CONCLUSION: In the invasion and LNM of HNSCC, ID2 plays an important role by modulating MMP1 expression, suggesting ID2-MMP1 axis to be a novel alternative therapeutic target for invasion and LNM of HNSCC.

Wnt/ß-catenin/Slug pathway contributes to tumor invasion and lymph node metastasis in head and neck squamous cell carcinoma.

The canonical Wnt/ß-catenin pathway is involved in diverse cancer development mechanisms, such as proliferation, migration, and invasion. However, its role in head and neck squamous cell carcinoma (HNSCC) remains largely unknown. We investigated whether the canonical Wnt/ß-catenin signaling pathway acts as a controller of invasion and lymph node metastasis (LNM) in HNSCC. Loss of function experiments against the canonical Wnt/ß-catenin pathway were conducted to evaluate its invasive and metastatic role in HNSCC cells. Slug was evaluated as a downstream protein in canonical Wnt/ß-catenin-mediated invasion. In addition, canonical Wnt/ß-catenin and Slug expression levels were examined in 119 HNSCC tissue samples to study the relevance of these proteins in LNM and prognosis of patients post-treatment. In vitro suppression of ß-catenin expression led to decreased migration and invasion of HNSCC cells. Using an in vivo mouse orthotopic LNM model, a decrease in LNM was observed with mitigated ß-catenin expression. Slug expression upregulation mediates invasion and LNM by the canonical Wnt/ß-catenin pathway. Simultaneous expression of ß-catenin and Slug is the major predictive factor of LNM and survival rate in patients with HNSCC. In conclusion, the canonical Wnt/ß-catenin/Slug signaling axis significantly contributes to cancer cell invasion and LNM. Its blockade may be a treatment strategy for LNM and tumor recurrence in HNSCC.

Prognostic impact of regulatory T cell in head and neck squamous cell carcinoma: A systematic review and meta-analysis.

OBJECTIVES: The impact of regulatory T (Treg) cells as a prognostic factor of survival in head and neck squamous cell carcinoma (HNSCC) remains controversial. We aimed to evaluate the prognostic value of Treg cells in patients with HNSCC through a meta-analysis. MATERIALS AND METHODS: Through a literature search in PubMed, Embase, and Cochrane, we included 11 articles in this meta-analysis and investigated the effect of Treg cell level on the survival of patients with HNSCC. Also, we performed a subgroup analysis according to the study sample (blood vs. tumor tissue), primary tumor site, HPV infectivity, or Treg cell marker. RESULTS: High levels of circulating Treg cells in the peripheral blood of patients with HNSCC can significantly increase the disease specific survival rate of patients. Moreover, subgroup analysis showed that high levels of Treg in peripheral blood were significantly associated with better disease specific survival in patients with oral cancer, a subsite of HNSCC, but not in those with other head and neck subsite. Positivity of HPV infection did not influence the prognosis of patients with HNSCC. CONCLUSION: Increase in the levels of circulating Treg cells in peripheral blood can be a prognostic factor of survival in patients with oral cancer.

The incidence of malignant brain tumors is increased in patients with obstructive sleep apnea: A national health insurance survey.

The association between obstructive sleep apnea (OSA) and malignant brain tumors has yet to be fully investigated. Therefore, the purpose of this study was to elucidate the effect of OSA on brain tumor incidence based on the Korea National Health Insurance Service (KNHIS) dataset. The KNHIS data between 2007 and 2014 were analyzed, and the primary endpoint was newly diagnosed malignant brain tumor. A total of 198,574 subjects aged ≥ 20 years with newly diagnosed OSA were enrolled in the study, and 992,870 individuals were selected as a control group based on propensity score matching (PSM) by gender and age. The average follow-up duration was 4.8 ± 2.3 years. The hazard ratios (HRs) for brain tumor for patients with OSA were 1.78 (95% confidence interval [CI]: 1.42-2.21) in Model 1 (not adjusted with any covariate) and 1.67 (95% CI: 1.34-2.09) in Model 2 (adjusted for income level, diabetes, hypertension, dyslipidemia, and COPD). In subgroup analysis by gender, the odds ratios (OR) of OSA were 1.82 (95% CI: 1.41-2.33) in men and 1.26 (95% CI: 0.74-2.03) in women. The ORs were 1.97 (95% CI: 1.15-3.24) in the older (age ≥ 65 years) group, 1.66 (95% CI: 1.25-2.17) in the middle-aged (40 ≤ age < 65 years) group, and 1.41 (0.78-2.44) in the young (20 ≤ age < 40 years) group. In conclusion, OSA may increase the incidence of brain tumors.

Slug is a novel molecular target for head and neck squamous cell carcinoma stem-like cells.

BACKGROUND: The acquisition of stem-like phenotype is partly attributed to the induction of epithelial-mesenchymal transition (EMT). Thus, the activation of factors involved in EMT can be linked to cancer stem cell genesis. However, the underlying mechanisms in head and neck squamous cell carcinoma (HNSCC) remain largely unknown. Herein, we investigate whether slug, one of the major effectors of EMT, affects the stemness of HNSCC cells. METHODS: We performed in vitro experiments to determine whether slug gene manipulation can influence the stemness phenotypes, including the capacity for self-renewal, expression of putative stemness markers, chemoresistance, and invasion in HNSCC cells. Further, we identified whether Slug knockout attenuates tumorigenicity of HNSCC cells in vivo. Finally, we examined whether prognosis of HNSCC patients after curative treatment may be affected by the level of slug expression. RESULTS: Overexpression of slug promoted self-renewal of HNSCC cells via activation of sphere formation, the expression of stem cell markers, and induction of chemoresistance to cisplatin. Also, slug overexpression increased the migration and invasion of HNSCC cells in vitro and was mainly observed during the invasion in HNSCC xenograft mouse model. By contrast, slug expression knockdown abrogated their self-renewal capacity, stemness-associated gene expression, and cisplatin chemoresistance. Furthermore, high levels of slug expression correlated with poor prognosis of patients with HNSCC. CONCLUSION: Inhibition of slug expression may represent a novel therapeutic strategy targeting HNSCC stem-like cells.

Association between obstructive sleep apnoea and breast cancer: The Korean National Health Insurance Service Data 2007-2014.

Some studies have argued that obstructive sleep apnoea (OSA) increases the risk of breast cancer. However, the results are often conflicting. This study aimed to investigate associations between OSA and breast cancer incidence using the Korea National Health Insurance Service (KNHIS) database. This retrospective cohort study analyzed data from the KNHIS database. A total of 45,699 women (≥20 years of age) newly diagnosed with OSA between 2007 and 2014 were included. The control groups were a 5-fold, age-matched women who had not been diagnosed with OSA. Mean follow-up duration was 3.7 ± 2.3 years. The primary endpoint was newly diagnosed breast cancer. The breast cancer hazard ratio (95% confidence interval) was calculated for patients with OSA and compared with that of the control group. The incidence of breast cancer among patients with OSA was significantly higher than that among the controls (1.20 [1.04-1.39]). In particular, the incidence of breast cancer was higher among patients aged ≥65 years (1.72 [1.10-2.71]). The result suggests that OSA may be a risk factor for breast cancer in women.

Role of integrin ß1 as a biomarker of stemness in head and neck squamous cell carcinoma.

OBJECTIVES: Signaling between cancer stem cells (CSC) and their extracellular matrix has a crucial role in CSC progression and maintenance. However, mediators of this signaling pathway in head and neck squamous cell carcinoma (HNSCC) are largely unknown. Here, we explored whether integrin ß1, which is one of the key regulators of the communication between cells and their microenvironment, affected the stemness of HNSCC cells. MATERIALS AND METHODS: We examined self-renewal capacity, chemoresistance, and xenograft tumorigenicity after knockdown of integrin ß1 in primary HNSCC cells. In addition, we studied the role of focal adhesion kinase (FAK), an intracellular downstream molecule of integrin signaling, in influencing stemness of HNSCC. The relevance of Notch1 and integrin ß1 interactions in HNSCC cells was also examined. Finally, immunohistochemical analysis was carried out to test whether the coexpression of integrin ß1 and Notch1 in the samples from HNSCC patients correlated with their survival. RESULTS: Targeting integrin ß1 in HNSCC cells inhibited self-renewal, chemoresistance, and in vivo tumor-forming capacity. Treatment with an inhibitor of FAK decreased self-renewal capacities and expression of various putative stem cell markers (Oct4, Sox2, and Nanog) in a dose-dependent manner. Moreover, knockdown of integrin ß1 decreased the expression of Notch1 and its target genes (Hey1 and Hes1). Notably, HNSCC patients demonstrating simultaneous expression of integrin ß1 and Notch1 in their tissue samples had significantly worse survival rate. CONCLUSION: Integrin ß1/Notch1 axis has a significant role in the regulation of stemness in HNSCC.

Conservative thyroidectomy for papillary thyroid microcarcinoma.

OBJECTIVE: According to American Thyroid Association (ATA) guideline, thyroid lobectomy is recommended for the management of papillary thyroid microcarcinomas (PTMC) with a diameter lesser than 1 cm. However, this procedure is associated with a risk of potential complications such as vocal cord palsy. Thus, we considered the applicability of conservative thyroidectomy, involving partial removal of the thyroid cancer lesion, not the entire ipsilateral thyroid lobe. METHODS: A retrospective analysis of all PTMC patients who underwent conservative thyroidectomy at Konkuk University Hospital between August 2008 and February 2014 was performed. Oncologic results of these patients along with the incidence of postoperative complications were evaluated. Seventy-nine patients who underwent conservative thyroidectomy for the treatment of PTMC were enrolled in the present study. RESULTS: Four of the 79 patients (5.0%) showed recurrence, 2 local (2.5%) and 2 regional (2.5%), respectively. All of these patients consequently underwent surgery alone and were salvaged. Temporary postoperative complications such as vocal cord palsy and hypocalcemia developed in 1 and 1 case, respectively, but completely recovered over time. CONCLUSIONS: Conservative thyroidectomy is an oncologically and functionally safe procedure for surgical treatment of PTMC and can be considered as an alternative to thyroid lobectomy for the surgical management of PTMC.

Uvulopalatopharyngoplasty reduces the incidence of cardiovascular complications caused by obstructive sleep apnea: results from the national insurance service survey 2007-2014.

OBJECTIVE: Untreated obstructive sleep apnea (OSA) is a risk factor for cardiovascular disease including myocardial infarction (MI), congestive heart failure (CHF), and atrial fibrillation (AF). Continuous positive airway pressure (CPAP) is an effective treatment for OSA; however, compliance with CPAP can be challenging for some patients. The objective of this study was to investigate whether uvulopalatopharyngoplasty (UPPP) reduced the risk of cardiovascular complications for patients with OSA. METHODS: Data from Korea National Health Insurance Corporation, a national health care database in South Korea, were analyzed. All patients with a new diagnosis of OSA from 2007 to 2014 were identified. Propensity score matching by age and sex was used to identify a control group five times larger than the OSA group for comparison. Patient demographics and comorbidities were collected. The OSA group was further divided into patients who had an UPPP and patients who did not undergo surgery. The primary endpoints were newly diagnosed MI, CHF, and AF. RESULTS: Of 192,316 patients with a new diagnosis of OSA, 22,213 had undergone UPPP. For the control group, 961,590 individuals were selected. Patients with OSA had an increased risk of CHF and AF, compared to control patients. UPPP reduced the incidence of CHF and AF significantly. Age, gender, and hypertension were also found to be risk factors for cardiac complications for patients with OSA. CONCLUSION: OSA increases the risk of CHF and AF. UPPP in this population can significantly reduce the risk of cardiac complications in patients with OSA.

Stem cell properties of human clonal salivary gland stem cells are enhanced by three-dimensional priming culture in nanofibrous microwells.

BACKGROUND: Three-dimensional (3D) cultures recapitulate the microenvironment of tissue-resident stem cells and enable them to modulate their properties. We determined whether salivary gland-resident stem cells (SGSCs) are primed by a 3D spheroid culture prior to treating irradiation-induced salivary hypofunction using in-vitro coculture and in-vivo transplant models. METHODS: 3D spheroid-derived SGSCs (SGSCs3D) were obtained from 3D culture in microwells consisting of a nanofiber bottom and cell-repellent hydrogel walls, and were examined for salivary stem or epithelial gene/protein expression, differentiation potential, and paracrine secretory function compared with monolayer-cultured SGSCs (SGSCs2D) in vitro and in vivo. RESULTS: SGSCs3D expressed increased salivary stem cell markers (LGR5 and THY1) and pluripotency markers (POU5F1 and NANOG) compared with SGSCs2D. Also, SGSCs3D exhibited enhanced potential to differentiate into salivary epithelial cells upon differentiation induction and increased paracrine secretion as compared to SGSCs2D. Wnt signaling was activated by 3D spheroid formation in the microwells and suppression of the Wnt/ß-catenin pathway led to reduced stemness of SGSCs3D. Enhanced radioprotective properties of SGSCs3D against radiation-induced salivary hypofunction was confirmed by an organotypic 3D coculture and in-vivo transplantation experiments. CONCLUSION: The 3D spheroid culture of SGSCs in nanofibrous microwells promotes stem cell properties via activation of Wnt signaling. This may contribute to SGSC priming prior to regenerative therapy to restore salivary hypofunction after radiotherapy.

LAMB3 mediates metastatic tumor behavior in papillary thyroid cancer by regulating c-MET/Akt signals.

Laminin subunit beta-3 (LAMB3) encodes one of the three subunits of LM-332, a protein of the extracellular matrix secreted by cultured human keratinocytes. While LAMB3 is involved in the invasive and metastatic abilities of several tumor types, including those found in the colon, pancreas, lung, cervix, stomach, and prostate, its mechanism of action in thyroid cancer has not been investigated previously. Our results show that LAMB3 is up-regulated in papillary thyroid cancer, and that its suppression reduces cell migration/invasion via down-regulation of epithelial‒mesenchymal transition-associated proteins (N-cadherin, vimentin, slug) and inhibition of matrix metalloproteinase 9. LAMB3 suppression also significantly decreases Akt phosphorylation and inhibits the transcription of c-MET, reducing its activation. These results suggest that LAMB3 leads to tumor invasion via Akt activation induced by the HGF/c-MET axis in papillary thyroid cancer cells. Our findings reveal a novel mechanism of action for LAMB3 in papillary thyroid cancer cells.

Inhibitor of DNA binding 2 is a novel therapeutic target for stemness of head and neck squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinomas (HNSCCs) are highly lethal epithelial tumours containing self-renewal cancer stem cells (CSCs). CSCs in HNSCCs are strongly associated with tumour initiation, invasion, and chemoradiation resistance. However, the important factors regulating stemness in HNSCCs remain unclear. Here, we investigated the molecular roles and clinical significance of inhibitor of DNA binding 2 (Id2) protein to determine if it constitutes a novel therapeutic target for ablating HNSCC cells with stemness. METHODS: We performed in vitro and in vivo studies of Id2 function and its effects on stemness using HNSCC cells. We also examined whether Id2 expression could be used as a prognostic indicator through immunohistochemical staining of 119 human HNSCC tumours. RESULTS: Expression of Id2 was higher in HNSCC cells with stemness compared with differentiated HNSCC cells. Overexpression of Id2 increased proliferation, self-renewal, and expression of the putative stemness marker CD44 in HNSCC cells in vitro and in vivo. In contrast, silencing of Id2 using short hairpin RNA attenuated the stemness phenotype of HNSCC cells by reducing self-renewal, CD44 expression, cisplatin chemoresistance, and xenograft tumourigenicity. Most importantly, increased expression of Id2 was closely associated with poorer post-treatment survival rates in HNSCC patients. CONCLUSIONS: Inhibitor of DNA binding2 represents a novel and promising therapeutic target for treating and improving the clinical outcomes for patients with HNSCC.

Menopausal hormone therapy may increase non-allergic rhinitis among postmenopausal women: Results from the Korea National Health and Nutrition Examination Survey (2010-2012).

OBJECTIVES: To investigate the association between menopausal hormone therapy (MHT) and chronic rhinitis. METHODS: The data used in this study were derived from the Korea National Health and Nutrition Examination Survey. The analysis included 2967 postmenopausal women under 70 years of age, and there were no missing data. Questionnaire responses regarding MHT, current life habits, reproductive history, and rhinitis were reviewed. The levels of total immunoglobulin E (IgE) and specific IgE for Dermatophagoides farinae, cockroaches, and dogs were measured, using approximately 10% of all samples. We compared women who were users of MHT and non-users of MHT. We also compared women with and without chronic rhinitis. RESULTS: Of 2967 women matching the study criteria, 567 were MHT users. The proportion of general rhinitis symptoms was greater among MHT users (24.5%) than among MHT non-users (18.9%, p=0.003). The proportion of cases of rhinorrhea or posterior nasal drip was also greater among MHT users (6.3% vs. 4.3%, p=0.042), while there were no differences between the two groups in the proportion of cases of nasal obstruction. There were no differences in total IgE and specific IgE levels between the two groups. MHT was used by 23.4% of women with chronic rhinitis and 18.0% of women without chronic rhinitis. Age, waist circumference, and body mass index were also greater among women without chronic rhinitis than among those with chronic rhinitis. CONCLUSIONS: MHT may cause non-allergic rhinitis in postmenopausal women. Age and obesity may also affect the occurrence of non-allergic rhinitis in postmenopausal women.

Lateral lymph node recurrence after total thyroidectomy and central neck dissection in patients with papillary thyroid cancer without clinical evidence of lateral neck metastasis.

BACKGROUND: This study analyzed the incidence, pattern, and predictive factors for lateral lymph node (LN) recurrence in patients with papillary thyroid cancer (PTC) without clinical evidence of lateral LN metastasis. METHODS: A retrospective analysis was performed on 246 patients with PTC who underwent total thyroidectomy and central neck dissection from 2004 to 2010. None of the patients had clinical evidence of lateral LN metastasis at the time of diagnosis. Predictive factors for lateral LN recurrence were evaluated using the chi-square test. Binary logistic regression was used for the multivariate analysis. Recurrence-free survival rates were estimated by the Kaplan-Meier and Cox regression methods. RESULTS: Of the 246 patients, 11 (4.5%) developed lateral LN recurrence with a median follow-up of 49months. In the multivariate analysis, tumor size >1cm (odds ratio [OR], 8.14; 95% confidence interval [CI], 1.01-65.68; p=0.049) and central LN metastasis (OR, 10.59; 95% CI, 1.32-85.17; p=0.026) were independent predictive factors of lateral LN recurrence. Especially, extranodal extension of a metastatic central LN (OR, 38.82; 95% CI, 5.71-264.10; p<0.001) was an independent predictor of lateral LN recurrence. CONCLUSIONS: Tumor size and central LN metastasis were independent predictors of lateral LN recurrence in patients with PTC without initial clinical lateral neck metastasis who underwent total thyroidectomy and central neck dissection. Close surveillance may be necessary for early detection of lateral LN recurrence in PTC patients with tumor size ⩾1cm, and central LN metastasis with extranodal extension.

Clinical implications of the extent of BRAFV600E alleles in patients with papillary thyroid carcinoma.

OBJECTIVE: There are many conflicting reports about the clinical implications of BRAFV600E in papillary thyroid cancer (PTC). We investigated the associations between the extent of BRAFV600E alleles and both clinico-pathological features and recurrence of PTC. MATERIALS AND METHODS: Carcinoma tissues from 60 patients with PTC were genotyped for BRAFV600E using pyrosequencing, and the clinico-pathological factors and disease outcomes of the patients were examined. The associations between the extent of mutant BRAF alleles and both clinico-pathological parameters and recurrence-free survival (RFS) were analyzed. RESULTS: The BRAFV600E mutation was detected in 66.7% (40/60) of our PTC patients. When we defined four groups on the basis of the extent of BRAFV600E alleles by pyrosequencing-negative (less than 5%), low (5 - less than 15%), intermediate (15 - less than 25%), and high (25% or greater)- the four groups showed statistically significant differences regarding lymph node (LN) metastasis and recurrence (P<0.05). However, age, gender, tumor size, multicentricity, capsular invasion, and lymphovascular invasion were not significantly different among the groups. The 10-year RFS rates in PTC patients with greater than 25% and less than 25% mutated BRAF alleles were 74% and 100%, respectively. This difference was significant (P=0.043). CONCLUSIONS: A high extent more than 25% of BRAFV600E alleles may be associated with disease outcome in PTC patients. We need more data to verify a hypothesis that the extent of BRAF mutations may be clinically informative in the management of PTC, such as by tailoring proper surgical and radioactive iodine treatments and determining appropriate management during follow-up.

EZH2 is associated with poor prognosis in head-and-neck squamous cell carcinoma via regulating the epithelial-to-mesenchymal transition and chemosensitivity.

OBJECTIVES: Increasing evidence suggests that epigenetic regulation is responsible for tumor initiation and progression in head and neck squamous cell carcinoma (HNSCC). Although the polycomb group protein enhancer zeste homolog 2 (EZH2) is upregulated and a key epigenetic modifier implicated in various cancers, its molecular mechanism in HNSCC remains unknown. Herein, we investigated the role of EZH2 in HNSCC progression and its clinical implication as an HNSCC risk predictor. MATERIALS AND METHOD: A retrospective analysis was performed on 90 HNSCC patients who had curative surgery between 1999 and 2011. Patients with high and low EZH2 expression were compared by the various clinicopathological factors. Survival rates were estimated by the Kaplan-Meier method and log-rank test was used to determine significance. For functional in vitro analysis, migration/invasion assay and Western blotting were performed after EZH2 knockdown using siRNA. In addition, cell proliferation was measured to clarify the role of EZH2 on cisplatin chemotherapy. RESULTS: In patients with HNSCC, high EZH2 expression was correlated with advanced T stage and poor survival outcome. RNAi analysis revealed that EZH2 silencing increased E-cadherin expression while decreasing that of N-cadherin and Vimentin without altering Snail/Slug signaling, which led to decreased cell migration/invasion. EZH2 is also associated with tumor aggressiveness via regulating the epithelial-to-mesenchymal transition. Furthermore, we show that high EZH2 expression decreases sensitivity to cisplatin-based chemotherapy. CONCLUSION: Our results indicate that EZH2 may not be only a predictive and prognostic biomarker but also a potential personalized therapeutic target for the treatment of HNSCC.