Jugao Fang

Genetic polymorphisms in cytochrome P450 genes are associated with an increased risk of squamous cell carcinoma of the larynx and hypopharynx in a Chinese population.

The purpose of this study was to examine whether functional polymorphisms in the cytochrome P450 (CYP) enzyme genes affect the risk of developing larynx and hypopharynx squamous cell carcinoma (SCC). We investigated CYP1A1, CYP1B1, CYP2E1, and CYP3A4 polymorphisms in 278 patients with laryngeal and hypopharyngeal SCC and 278 control subjects by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Subjects with the CYP1A1 3798CC or TC genotype had an odds ratio (OR) of 3.26 (95% confidence interval CI=1.76-6.03) or 1.56 (95% CI=1.06-2.31), compared with those with the TT genotype. An increased risk was also associated with the CYP1A1 462Val/Val genotype (OR=2.39, 95% CI=1.11-5.16), compared with the TT genotype. Haplotype analysis suggested a synergistic effect of these two polymorphisms. A multiplicative joint effect between the CYP1A1 3798T>C polymorphism and smoking was observed. The OR (95% CI) of the TC or CC genotype for nonsmokers and smokers of >20 pack-years were 1.85 (0.99-3.44) or 8.15 (4.35-15.26), respectively (P(trend)<0.05). The CYP1A1 single-nucleotide polymorphisms are associated with an increased risk of developing smoking-related laryngeal and hypopharyngeal SCC in a Han Chinese population.

Knockdown of zinc finger protein, X-linked (ZFX) inhibits cell proliferation and induces apoptosis in human laryngeal squamous cell carcinoma

ZFX (zinc finger protein, X-linked) gene locus on the human X chromosome is structurally similar to the zinc finger protein, Y-linked gene, which may constitute the primary sex-determining signal. However, the pathological roles of the dysfunction of ZFX gene in human disease such as cancer have not been addressed. Here, we analyzed the expression of ZFX in human laryngeal squamous cell carcinoma (LSCC) tissue specimens and found a significant up-regulation compared to corresponding non-tumorous LSCC tissue. Recombinant lentivirus expressing ZFX short hairpin RNA (shZFX) was constructed and infected Hep-2 human LSCC cells. We found that knockdown of ZFX gene resulted in suppression of proliferation and colony-forming ability of Hep-2 cells, and led to S phase cell cycle arrest. In addition, down-regulation of ZFX induced a significant enhancement of cell apoptosis and expression changes of apoptosis-related genes. These results suggest that high expression of ZFX is associated with LSCC progression and knockdown of ZFX may block tumor cell growth mainly by promoting cell apoptosis.

Detection of circulating tumour cells with the CellSearch system in patients with advanced-stage head and neck cancer: preliminary results

OBJECTIVE To assess the feasibility and clinical value of using the CellSearch system to detect circulating tumour cells in patients with advanced-stage head and neck squamous cell carcinoma. METHODS Circulating tumour cells were isolated and counted via positive selection utilising magnetically labelled anti-epithelial cell adhesion molecule and immunocytochemical staining for cytokeratin. The correlation between circulating tumour cell presence and clinical features was evaluated in nine patients newly diagnosed with advanced-stage (stage III or IV) head and neck squamous cell carcinoma. RESULTS Circulating tumour cells were detected in three of the nine patients (33 per cent). Circulating tumour cell positivity was more prevalent in node stage 2 to 3 patients (3 of 5, 60 per cent) than node stage 0 to 1 patients (0 of 4, 0 per cent). Recurrent or progressive disease was observed in only one of the six patients (17 per cent) without circulating tumour cells, compared with two of the three patients (67 per cent) with circulating tumour cells. CONCLUSION In this preliminary study, circulating tumour cells were successfully isolated in patients with advanced-stage head and neck squamous cell carcinoma, using the CellSearch system. Further investigation is needed to evaluate the prognostic significance of circulating tumour cells.

Identification of nucleolus-localized PTEN and its function in regulating ribosome biogenesis

The tumor suppressor PTEN is a lipid phosphatase that is found mutated in different types of human cancers. PTEN suppresses cell proliferation by inhibiting the PI3K-Akt signaling pathway at the cell membrane. However, PTEN is also demonstrated to localize in the cell nucleus where it exhibits tumor suppressive activity via a different, unknown mechanism. In this study we report that PTEN also localizes to the nucleolus and that nucleolar PTEN plays an important role in regulating nucleolar homeostasis and maintaining nucleolar morphology. Overexpression of nuclear PTEN in PTEN null cells inhibits Akt phosphorylation and reduces cell size. Knockdown of PTEN in PTEN positive cells leads to nucleolar morphologic changes and an increase in the proportion of cells with a greater number of nucleoli. In addition, knockdown of PTEN in PTEN positive cells increased ribosome biogenesis. These findings expand current understanding of function and relevance of nuclear localized PTEN and provide a foundation for the development of novel therapies targeting PTEN.

Microarray Gene Expression Analysis of Tumorigenesis and Regional Lymph Node Metastasis in Laryngeal Squamous Cell Carcinoma

Background Laryngeal squamous cell carcinoma (LSCC) is the most common type in head and neck squamous cell carcinoma (HNSCC), and the development and progression of LSCC are multistep processes accompanied by changes of molecular biology. Objective The purpose of this study was to investigate the molecular basis of tumorigenesis and regional lymph node metastasis in LSCC, and provide a set of genes that may be useful for the development of novel diagnostic markers and/or more effective therapeutic strategies. Methods A total number of 10 patients who underwent surgery for primary laryngeal squamous cell carcinoma were recruited for microarray analysis. LSCC tissues compared with corresponding adjacent non-neoplastic tissues were analysed by Illumina mRNA microarrays, and LSCC tissues with regional lymph node metastasis and LSCC tissues without regional lymph node metastasis were analyzed in the same manner. The most frequently differently expressed genes screened by microarrays were also validated by qRT-PCR in another 42 patients diagnosed for LSCC. Results Analysed by Illumina mRNA microarrays, there were 361 genes significantly related to tumorigenesis while 246 genes significantly related to regional lymph node metastasis in LSCC. We found that the six genes (CDK1, CDK2, CDK4, MCM2, MCM3, MCM4) were most frequently differently expressed functional genes related to tumorigenesis while eIF3a and RPN2 were most frequently differently expressed functional genes related to regional lymph node metastasis in LSCC. The expressions of these genes were also validated by qRT-PCR. Conclusions The research revealed a gene expression signature of tumorigenesis and regional lymph node metastasis in laryngeal squamous cell carcinoma. Of the total, the deregulation of several genes (CDK1, CDK2, CDK4, MCM2, MCM3, MCM4, EIF3a and RPN2) were potentially associated with disease development and progression. The result will contribute to the understanding of the molecular basis of LSCC and help to improve diagnosis and treatment.

Genome-wide association study identifies three susceptibility loci for laryngeal squamous cell carcinoma in the Chinese population

To identify genetic markers for laryngeal squamous cell carcinoma (LSCC), we conducted a genome-wide association study (GWAS) on 993 individuals with LSCC (cases) and 1,995 cancer-free controls from Chinese populations. The most promising variants (association P < 1 × 10−5) were then replicated in 3 independent sets including 2,398 cases and 2,804 controls, among which we identified 3 new susceptibility loci at 11q12 (rs174549), 6p21 (rs2857595) and 12q24 (rs10492336). The minor alleles of each of these loci showed protective effects, with odds ratios (95% confidence intervals) of 0.73 (0.68–0.78; P = 1.00 × 10−20), 0.78 (0.72–0.84; P = 2.43 × 10−15) and 0.71 (0.65–0.77; P = 4.48 × 10−14), respectively. None of these variants showed an interaction with smoking or drinking. This is the first GWAS to our knowledge solely on LSCC, and the findings might advance understanding of the etiology of LSCC.

Rhinoscleroma: A retrospective study of pathologic and clinical features

OBJECTIVE Rhinoscleroma, a chronic granulomatous bacterial disease of the nasal mucosa that often extends through the lower respiratory tract, is caused by infection with the gram-negative bacillus Klebsiella rhinoscleromatis (KR). We report the clinicopathology and histology associated with KR infection-induced rhinoscleroma in patients admitted to the Beijing Tongren Hospital over a 30-year period. METHODS The clinical and pathologic features of 40 cases of upper aerodigestive tract infections were retrospectively studied. Histochemical examination of biopsy samples was performed, including periodic acid-Schiff, modified Warthin-Starry, and acid-fast stains. In addition, immunohistochemical staining for CD43, CD20, CD68, and lysozymes was performed in 11 specimens, and 8 specimens were analyzed by transmission electron microscopy. RESULTS KR infection was confirmed in each of the 40 samples. Twenty-seven patients remained relapse free 1 to 10 years following treatment with antibiotic supplemented in some cases with surgery or radiotherapy, and all 13 cases of relapse were successfully eradicated by the end of treatment. KR infection was localized to phagosomes within Mikulicz cells, as determined by immunohistochemistry and electron microscopy. Significant tissue injury was observed in most cases. CONCLUSION Long-term antibiotic therapy successfully eradicated KR infection in all cases. Although late diagnosis was common in this cohort, retrospective examination of biopsy samples suggests that diagnosis can be improved by combining clinical findings with histologic analysis.

Salvage transoral laser microsurgery for early recurrent glottic carcinoma after primary laser treatment

Abstract Conclusion: Salvage transoral laser microsurgery (TLM) may be a curative organ-preserving treatment for early recurrent glottic carcinoma after primary laser resection. However, failure after TLM seems to be associated with decrease of survival and larynx preservation rates. Objective: To evaluate the oncological results of salvage TLM for early recurrent glottic carcinoma after primary laser treatment. Methods: Records of 50 patients with local recurrences of glottic carcinoma treated by salvage TLM between January 1994 and December 2008 were retrospectively analyzed. Results: Thirty-six rT1 and 14 rT2 lesions were treated with salvage TLM. Mean follow-up was 68.3 months. Thirty-one patients were cured by first salvage TLM and four by further laser procedures. The other 15 patients were finally salvaged by laryngectomy or radiotherapy. Five-year overall survival, disease-specific survival, local control, and loco-regional control rates were 89.9%, 97.9%, 62.3%, and 60.1%, respectively. Larynx preservation rate after long-term follow-up was 86%. In univariate analysis, second local recurrence showed a statistically significant impact on disease-specific survival rate ( p = 0.049) and larynx preservation rate ( p = 0.006). In multivariate analysis, it was associated with a statistically significant decrease in larynx preservation rate ( p = 0.016). There was no statistically significant difference in oncological results between patients with and without anterior commissure involvement.

Endoscopic endonasal resection of esthesioneuroblastoma: A single center experience of 24 patients.

OBJECTIVE Esthesioneuroblastoma (ENB) is an uncommon malignant tumor. During the past decade, endoscopic approaches have been gradually applied in treating skull base tumors. However, the experience in using this approach to treat ENB is still limited. Kadish staging and Dulguerov staging are common methods used for ENB staging, but it remains unclear as to which method is better. In this study, we reviewed our experiences with endoscopic surgeries for ENB and analyzed the prognostic roles of the two staging methods. METHODS A total of 24 patients with ENB treated with only endoscopic endonasal surgery between January 2001 and March 2012 were included. Overall survival (OS) and disease-free survival (DFS) were analyzed using the Kaplan-Meier method and early and advanced stages were compared using the log-rank test. The prognostic roles of the two staging methods were also analyzed. RESULTS Amongst the 24 patients, 19 patients presented with newly diagnosed ENB, and 5 patients presented with recurrent disease. The three-year OS and DFS rates were 82% and 70.8%, respectively. Four patients (16.6%) died from recurrence of the tumor. Dulguerov staging predicted OS with significant differences (P=0.042), whereas Kadish staging predicted DFS with significant differences (P=0.020) between the early and advanced stages. CONCLUSIONS The present study showed experiences that purely endoscopic endonasal surgery for ENB showed successful survival results with remarkably decreased complications. Dulguerov staging and Kadish staging play different prognostic roles in patients treated with purely endoscopic endonasal resection based on various end points.

Inhibition of GSK 3β Activity Is Associated with Excessive EZH2 Expression and Enhanced Tumour Invasion in Nasopharyngeal Carcinoma

Background Enhancer of zeste homolog 2 (EZH2) has been shown to contribute to tumour development and/or progression. However, the signalling pathway underlying the regulation of EZH2 in nasopharyngeal carcinoma (NPC) remains unclear. Since EZH2 contains the putative Glycogen synthase kinase 3 beta (GSK3β) phosphorylation motif ADHWDSKNVSCKNC (591) and may act as a possible substrate of GSK-3β, it is possible that inactivation of GSK3β may lead to excessive EZH2 expression in NPC. Method We first examined the expression of EZH2 and phosphorylated GSK3β (p-GSK3β) by immunohistochemical staining in NPC samples. Then, we evaluated the interaction of GSK3β and EZH2 using immunoprecipitation and immune blot. Moreover, we determined the effect of inhibition of GSK3β activity on EZH2 expression and tumor invasiveness in NPC cell lines in vitro. Finally, we evaluated the invasive properties of NPC cells after knocking down EZH2 expression with EZH2 siRNA. Results We found that expression of EZH2 correlated with phosphorylated GSK3β (p-GSK3β) at Ser 9 (an inactivated form of GSK3β) in human nasopharyngeal carcinoma (NPC) samples. We also provided evidence that GSK3β is able to interact with EZH2 using immunoprecipitation and immune blot. Furthermore, we found that inhibition of GSK3β activity can lead to upregulation of EZH2 in NPC cell lines in vitro, with enhanced local invasiveness. By knocking down EZH2 expression with EZH2 siRNA, we found that these invasive properties were EZH2 dependent. Conclusion Our findings indicate that GSK3β inactivation may account for EZH2 overexpression and subsequent tumour progression, and this mechanism might be a potential target for NPC therapy.