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.

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.

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.

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.

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.

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.

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.

Wnt/ß-catenin signalling maintains self-renewal and tumourigenicity of head and neck squamous cell carcinoma stem-like cells by activating Oct4.

Accumulating evidence suggests that a distinct subpopulation of cancer stem cells (CSCs) is responsible for tumour initiation and progression in head and neck squamous cell carcinoma (HNSCC). Wnt/ß-catenin signalling is essential for stem cell regulation and tumourigenesis, but its molecular mechanism in HNSCC CSCs remains unknown. We investigated whether Wnt/ß-catenin signalling regulates self-renewal and tumourigenicity of HNSCC stem-like cells in vitro and in vivo. Cytoplasmic/nuclear ß-catenin, a major effector of Wnt/ß-catenin signalling, was expressed in a subpopulation of tumour cells in primary HNSCC tissue but in none of normal head and neck tissues. Overexpression of ß-catenin increased proliferation of HNSCC cells and induced dedifferentiation of these cells to cells with stem-like features. Knockdown of ß-catenin in HNSCC stem-like cells blocked their self-renewal capacity, stemness-associated gene expression, chemoresistance, and in vivo tumourigenicity. Furthermore, ß-catenin directly regulates Oct4 transcription in HNSCC stem-like cells. In addition, the effect of shRNA-mediated repression of ß-catenin on CSC traits in HNSCC stem-like cells was reversed by overexpression of Oct4. In patients with HNSCC, higher levels of both cytoplasmic/nuclear ß-catenin and Oct4 correlated with the worst prognosis. These results suggest inhibition of Wnt/ß-catenin signalling as a novel therapeutic strategy for targeting HNSCC stem-like cells.

Upregulation of HGF and c-MET is associated with subclinical central lymph node metastasis in papillary thyroid microcarcinoma.

BACKGROUND: Identification of a novel biomarker of subclinical lymph node metastasis (SLNM) in papillary thyroid microcarcinoma (PTMC) could provide important clues regarding SLNM in PTMC. We evaluated the significance of HGF and c-Met expression in surgically removed tumor tissue from PTMC patients as a predictive marker of SLNM. METHODS: We analyzed the immunohistochemical relationship between HGF and c-Met expression and SLNM in 113 surgically treated PTMC patients with clinically negative nodes presurgery. In addition, we explored whether HGF/c-Met pathway activation enhanced the in vitro migration and invasion of PTC cells. RESULTS: Positive immunohistochemical HGF and c-Met staining was found in 107 (95 %) and 103 (91 %) cases, respectively. The HGF staining distribution was as follows: no staining in 6 cases, weak staining in 43, moderate staining in 55, and strong staining in 9. Of the nine cases with strong HGF staining, eight (89 %) had SLNM. The c-Met staining distribution was as follows: no staining in 10 cases, weak staining in 39, moderate staining in 59, and strong staining in 5. Of the five cases with strong c-Met staining, three (60 %) had SLNM. The presence of SLNM was strongly correlated with HGF and c-Met expression in PTMC in a univariate analysis (P < 0.05). HGF overexpression was also associated with SLNM in a multivariate analysis (P < 0.05). Stimulation with exogenous HGF and constitutive activation of c-Met enhanced the migration and invasion of PTC cells in vitro by enhancing VEGF-A expression. CONCLUSIONS: HGF/c-Met pathway activation is associated with SLNM of the central neck in PTMC.

Interferon regulatory factor 7 regulates glioma stem cells via interleukin-6 and Notch signalling.

Inflammatory microenvironment signalling plays a crucial role in tumour progression (i.e. cancer cell proliferation, survival, angiogenesis and metastasis) in many types of human malignancies. However, the role of inflammation in brain tumour pathology remains poorly understood. Here, we report that interferon regulatory factor 7 is a crucial regulator of brain tumour progression and heterogeneity. Ectopic expression of interferon regulatory factor 7 in glioma cells promotes tumorigenicity, angiogenesis, microglia recruitment and cancer stemness in vivo and in vitro through induction of interleukin 6, C-X-C motif chemokine 1 and C-C motif chemokine 2. In particular, interferon regulatory factor 7-driven interleukin 6 plays a pivotal role in maintaining glioma stem cell properties via Janus kinase/signal transducer and activator of transcription-mediated activation of Jagged-Notch signalling in glioma cells and glioma stem cells derived from glioma patients. Accordingly, the short hairpin RNA-mediated depletion of interferon regulatory factor 7 in glioma stem cells markedly suppressed interleukin 6-Janus kinase/signal transducer and activator of transcription-mediated Jagged-Notch-signalling pathway, leading to decreases in glioma stem cell marker expression, tumoursphere-forming ability, and tumorigenicity. Furthermore, in a mouse model of wound healing, depletion of interferon regulatory factor 7 suppressed tumour progression and decreased cellular heterogeneity. Finally, interferon regulatory factor 7 was overexpressed in patients with high-grade gliomas, suggesting its potential as an independent prognostic marker for glioma progression. Taken together, our findings indicate that interferon regulatory factor 7-mediated inflammatory signalling acts as a major driver of brain tumour progression and cellular heterogeneity via induction of glioma stem cell genesis and angiogenesis.

Cellular characteristics of head and neck cancer stem cells in type IV collagen-coated adherent cultures.

Although head and neck squamous carcinoma cancer stem cells (HNSC-CSCs) can be enriched in serum-free suspension cultures, it is difficult to stably expand HNSC-CSC lines in suspension due to spontaneous apoptosis and differentiation. Here, we investigated whether HNSC-CSCs can be expanded without loss of stem cell properties by adherent culture methods. Cell culture plates were coated with type IV collagen, laminin, or fibronectin. We examined cancer stem cell traits of adherent HNSC-CSCs grown on these plates using immunocytochemistry for stem cell marker expression and analyses of chemo-resistance and xenograft tumorigenicity. We also assessed the growth rate, apoptosis rate, and gene transduction efficiency of adherent and suspended HNSC-CSCs. HNSC-CSCs grew much faster on type IV collagen-coated plates than in suspension. Adherent HNSC-CSCs expressed putative stem cell markers (OCT4 and CD44) and were chemo-resistant to various cytotoxic drugs (cisplatin, fluorouracil, paclitaxel, and docetaxel). Adherent HNSC-CSCs at the limiting dilution (1000 cells) produced tumors in nude mice. Adherent HNSC-CSCs also showed less spontaneous apoptotic cell death and were more competent to lentiviral transduction than suspended HNSC-CSCs. In conclusion, compared to suspension cultures, adherence on type IV collagen-coated culture plates provides better experimental conditions for HNSC-CSC expansion, which should facilitate various refined cellular studies.

hMSC-mediated concurrent delivery of endostatin and carboxylesterase to mouse xenografts suppresses glioma initiation and recurrence.

Glioma stem cells (GSCs) are known to be maintained within a "vascular niche"; thereby, disruption of this microenvironment using antiangiogenesis agents is a promising therapeutic modality. However, this regimen leads to treatment failure and tumor recurrence in patients with glioblastoma multiforme (GBM). Therefore, more effective therapeutic approaches that can eradicate GSCs and the bulk tumors are needed. Toward this goal, we examined the antitumor effects of an antiangiogenesis approach combined with conventional chemotherapy on suppressing glioma xenograft growth. We established three genetically engineered mesenchymal stem cell (MSC) lines (GE-AF-MSCs) by stably transducing the gene encoding endostatin (an antiangiogenesis factor), the gene encoding secretable form of carboxylesterase 2 (sCE2, a prodrug-activating enzyme), or a mixture of both genes. Among the three GE-AF-MSC cell lines, injection of amniotic fluid (AF)-MSCs-endostatin-sCE2 cells into U87MG-EGFRvIII-driven orthotopic brain tumor and postsurgery tumor recurrence models, and subsequent CPT11 treatment yielded the strongest antitumor responses, including diminished angiogenesis, increased cell death, and a reduced Nestin-positive GSC population. Therefore, our antitumor strategy provides a novel basis for designing stem cell-mediated therapeutic approaches to target and eradicate GSCs and the bulk tumors.

Epigallocatechin-3-gallate induces growth inhibition and apoptosis of human anaplastic thyroid carcinoma cells through suppression of EGFR/ERK pathway and cyclin B1/CDK1 complex.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) is one of the most lethal cancers because of its aggressiveness and the lack of efficacious therapy. Epigallocatechin-3-gallate (EGCG), a major catechin in green tea, was shown to possess remarkable therapeutic potential against various types of human cancer cells in in vitro and in vivo models. The aim of this study was to investigate the effect of EGCG on the proliferation and apoptosis of ARO cells--human ATC cells. STUDY DESIGN: Experimental study. METHODS: Human ATC cell line, ARO, was treated with EGCG. Cell viability was assessed by MTT assay. Inhibition of EGFR/MAPK pathway and cell cycle-related proteins by EGCG were measured by Western blot analysis. In addition, cell cycle analysis was measured by flow cytometry. RESULTS: EGCG treatment inhibited the growth of ARO cells in a dose-dependent manner. Furthermore, EGCG suppressed phosphorylation of EGFR, ERK1/2, JNK, and p38. These changes were associated with increased p21 and reduced cyclin B1/CDK1 expression. In addition, EGCG treatment increased the accumulation of sub-G1 cell, activated caspase-3 and cleaved PARP. CONCLUSIONS: Taken together, EGCG inhibits cell proliferation and induces apoptosis via suppression of the EGFR/ERK pathway and cyclin B1/CDK1 complex in ATC cells.

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.

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.

Occult contralateral carcinoma in patients with unilateral papillary thyroid microcarcinoma.

BACKGROUND: The optimal resection extent for papillary thyroid microcarcinoma (PTMC) confined within a unilateral lobe remains controversial. MATERIALS AND METHODS: We reviewed the medical records of 132 consecutive patients who underwent total thyroidectomy for the treatment of clinically unilateral PTMC between March 2005 and March 2009. The frequency, pattern, and predictive factors for occult contralateral carcinoma in these patients were analyzed with respect to the following variables: age, gender, tumor size, multifocality of primary tumor, presence of perithyroidal invasion, lymphovascular invasion or capsular invasion, presence of central lymph node metastasis, and the presence of coexistent benign nodules in the contralateral lobe based on preoperative evaluation and final pathology. RESULTS: A total of 22 patients (16.7%) had occult PTMC in the contralateral lobe. In multivariate analysis, multifocality of the primary tumor (P = 0.026, odds ratio = 7.714) and the presence of coexistent benign nodule in the contralateral lobe by preoperative evaluation (P = 0.036, odds ratio = 3.500) were independent predictive factors for occult contralateral PTMC presence. However, there were no significant differences between the presence of occult contralateral carcinomas and age, gender, tumor size, perithyroidal invasion, lymphovascular invasion, capsular invasion, central lymph node metastasis, and coexistent benign nodules by final pathology. CONCLUSIONS: Based on our findings, total thyroidectomy, including the contralateral lobe, should be considered for the treatment of unilateral PTMC if it presents as a multifocal tumor in the unilateral lobe and/or if nodules are found in the contralateral lobe during preoperative evaluation.

Prophylactic lymphadenectomy of neck level II in clinically node-positive papillary thyroid carcinoma.

BACKGROUND: The purpose of this study was to examine the frequency, pattern, and predictive factors associated with occult level II lymph node (LN) metastases in papillary thyroid carcinoma (PTC) patients with clinically metastatic lymph nodes in the lateral neck (level III, IV, and/or V) by preoperative ultrasonography. METHODS: We retrospectively reviewed the medical records of 52 PTC patients with clinically positive neck lymph nodes in level III, IV, and/or V based on preoperative ultrasonography, who underwent therapeutic lateral neck dissection (ND) (level II-V) between March 2004 and October 2009. All patients had no suspicion of clinically positive neck nodes in level II. Histopathological analysis of neck specimens according to each node level of the neck was performed, with special attention given to level II. RESULTS: Forty-two (81%), 41 (79%), and 6 (12%) patients had histologically positive lymph nodes in level III, IV, and V, respectively. Occult metastases in level II were observed in ten (19%) patients. Patients without suspicious positive LNs in both neck level III and IV by preoperative ultrasonography, and patients without pathologic LN metastases in level III, had no occult LN metastases occurrence to level II. Based on multivariate analysis, presence of more than four metastatic LNs was an independent predictive factor for occult level II metastases [P = 0.022, odds ratio (OR) = 7.738]. CONCLUSIONS: Prophylactic level II LN dissection may be omitted in PTC patients with clinically positive neck nodes if suspicious positive lymph nodes in level III are absent during preoperative ultrasonography.

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.

Predictive factors for ipsilateral or contralateral central lymph node metastasis in unilateral papillary thyroid carcinoma.

OBJECTIVES: To investigate the incidence and the risk factors for occult ipsilateral or contralateral central neck lymph node (LN)metastasis in patients with unilateral papillary thyroid carcinoma (PTC) and a clinically negative neck. SUMMARY BACKGROUND DATA: Elective central lymph node dissection (CLND) in patients with PTC remains controversial. There have been few prospective studies assessing accurate histopathologic information and predictive factors for the presence of metastasis to the ipsilateral or contralateral central compartment of the neck in patients with PTC and clinically negative neck nodes. METHODS: We reviewed a prospective protocol of 111 unilateral PTC patients with clinically node-negative necks who have received total thyroidectomy and elective bilateral CLND from 2005 to 2007. The relationships between LN metastasis to the ipsilateral or contralateral central neck compartment and clinico-pathologic factors such as age, sex, size of primary tumor, perithyroidal invasion, lymphovascular invasion, and capsular invasion were analyzed. RESULTS: Occult central neck LN metastasis was present in 54.1% (60/111). Of these patients, bilateral central LN metastases were present in 50% (30/60), unilateral ipsilateral central LN metastasis in 43.3% (26/60), and unilateral contralateral central LN metastasis in 6.7% (4/60). In the univariate analysis, the rate of ipsilateral central LN metastasis was significantly higher in male patients, high risk MACIS score, carcinoma with a maximal diameter of greater than 1 cm, and carcinoma with lymphovascular invasion (P < 0.05). The rate of contralateral central LN metastasis was significantly higher in cases of carcinoma with a maximal diameter of greater than 1 cm, lymphovascular invasion or histologically proven metastasis to the ipsilateral central LN (P < 0.05). Multivariate analysis showed that the tumor size was an independent risk factor for the presence of ipsilateral central LN metastasis, and the presence of ipsilateral central LN metastasis was the only independent predictor for the presence of contralateral central LN metastasis. CONCLUSIONS: Unilateral PTC with a maximal diameter of greater than 1 cm is associated with a high rate of ipsilateral central neck LN metastasis. Moreover, ipsilateral central LN metastasis is a potential independent predictor of synchronous contralateral central LN metastasis. These findings suggest that contralateral as well as ipsilateral elective CLND, performed during the initial thyroid operation, may be effective in the management of patients with unilateral PTC having a maximal diameter of greater than 1 cm and ipsilateral central LN metastasis.