Qinglai Tang

Prognostic role of epidermal growth factor-like domain 7 protein expression in laryngeal squamous cell carcinoma.

OBJECTIVE This study aimed to retrospectively analyse the expression of epidermal growth factor-like domain 7 protein in cases of laryngeal squamous cell carcinoma. METHODS We studied 116 patients retrospectively. Expression of epidermal growth factor-like domain 7 protein was determined in tumour and nontumour tissue samples, by immunohistochemistry. RESULTS Expression levels were significantly increased in 94 cases. Increased expression levels correlated well with tumour stage (p = 0.001) and lymph node metastasis (p = 0.002). Log-rank survival testing showed a significant difference between patients with marked versus limited expression levels (p = 0.03). Multivariable Cox regression analysis showed that epidermal growth factor-like domain 7 protein expression level was an independent predictor of laryngeal squamous cell carcinoma prognosis. CONCLUSION These findings provide evidence that increased epidermal growth factor-like domain 7 protein expression is associated with laryngeal squamous cell carcinoma stage, lymph node metastasis and poor survival. This suggests that this protein may be a potential marker for laryngeal squamous cell carcinoma.

Latent membrane protein 1 mediates the resistance of nasopharyngeal carcinoma cells to TRAIL-induced apoptosis by activation of the PI3K/Akt signaling pathway

The 5-year survival rate of nasopharyngeal carcinoma (NPC) is still disappointing despite the much improved technologies in its treatment. Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) can selectively induce apoptosis in most tumor cells while sparing normal cells. However, its potential in the treatment of NPC has been limited by the eventual emergence of drug resistance. Latent membrane protein 1 (LMP1) is a major oncogene of the human DNA tumor virus Epstein-Barr virus (EBV) and is associated with the development of NPC and the emergence of chemo-resistance in NPC. In this study, we investigated the potential role of LMP1 in TRAIL resistance in CNE-1 NPC cells. Results show that overexpression of LMP1 could induce TRAIL resistance in NPC cells without influencing death receptors. The LMP1-induced TRAIL resistance is associated with increased expression of FLIP and elevated cleavage of caspase-8 without altering the TRAIL-mediated mitochondrial events and Bid cleavage. Knockdown of the FLIP gene with siRNA prevented the LMP1-induced TRAIL resistance. Furthermore, we found that overexpression of LMP1 activated Akt. Inhibition of Akt with LY294002 completely prevented the LMP1-induced FLIP expression and TRAIL resistance. Together, these results show that LMP1 can inhibit the TRAIL-mediated apoptosis through activation of PI3K/Akt and expression of FLIP in CNE-1 NPC cells, and may provide new methods to prevent and reverse drug resistance in NPC.

Simultaneously Targeting Bcl-2 and Akt Pathways Sensitizes Nasopharyngeal Carcinoma to Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand

The 5-year survival rate of nasopharyngeal carcinoma (NPC) is disappointing despite the much improved technologies in its treatment. Thus, finding more effective treatment for NPC has become an urgent priority. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis in most tumor cells while sparing normal cells. However, its potential in the treatment of NPC has been limited by the eventual emergence of drug resistance. Bcl-2 and Akt contribute to TRAIL resistance in some cancer cells. In this study, CNE-2 was found to be the most resistant NPC cell line to TRAIL, and whether Bcl-2 small-interfering RNA (siRNA) and phosphatidylinositol 3-kinase (PI3-K) inhibitors (LY294002 and Wortmannin) could prevent TRAIL resistance in CNE-2 was also investigated. Results showed that both Bcl-2 siRNA and PI3-K inhibitors could prevent TRAIL resistance in CNE-2. Bcl-2 siRNA sensitized CNE-2 by activating the intrinsic apoptotic pathway and PI3-K inhibitors sensitized CNE-2 by activating both intrinsic and extrinsic pathways. Further, simultaneously targeting Bcl-2 and Akt was found to be a more efficient approach to prevent TRAIL resistance in CNE-2 and this synergistic effect happened at the level of Bid downstream. At last, the combinative treatments did not enhance toxicity of TRAIL in MRC5, a human benign fibroblast cell line. This study suggests that simultaneously targeting Bcl-2 and Akt pathway might be effective in preventing TRAIL resistance of NPC cells.

Inhibition of HAX-1 by miR-125a reverses cisplatin resistance in laryngeal cancer stem cells

Chemoresistance is a major obstacle in chemotherapy of laryngeal carcinoma. Recently, studies indicate that cancer stem cells are responsible for chemotherapy failure. In addition, microRNAs play important roles in tumor initiation, development and multidrug resistance. In the present study, we found that the expression of microRNA-125a was decreased in laryngeal carcinoma tissues and Hep-2 laryngeal cancer stem cells (Hep-2-CSCs). MicroRNA-125a gain-of-function significantly increased the sensitivity of Hep-2-CSCs to cisplatin in vitro and in vivo. Combination with microRNA-125a mimics can decrease the half maximal inhibitory concentration of Hep-2-CSCs to cisplatin. Mechanically, we found that microRNA-125a reverses cisplatin resistance in Hep-2-CSCs by targeting Hematopoietic cell-specific protein 1-associated protein X-1 (HAX-1). Inhibition of HAX-1 by microRNA-125a significantly promotes the cisplatin-induced apoptosis in Hep-2-CSCs through mitochondrial pathway. In addition, multidrug resistance of Hep-2-CSCs to vincristine, etoposide and doxorubicin was greatly improved after the cells were transfected with microRNA-125a mimics. These dates strongly suggested the promotion of microRNA-125a/HAX-1 axis on chemotherapy of laryngeal carcinoma.

Simultaneously targeting Bcl-2 and Akt pathways reverses resistance of nasopharyngeal carcinoma to TRAIL synergistically.

AIMS AND BACKGROUND Despite progress in treatment techniques, the five-year survival rate of nasopharyngeal carcinoma (NPC) is disappointing. Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) can selectively induce apoptosis in most tumor cells while sparing normal cells. Given the antiapoptotic functions of Bcl-2 and Akt, we examined the effects of targeting these pathways alone or simultaneously on TRAIL apoptosis in NPC cell lines. METHODS AND STUDY DESIGN We first tested the cytotoxic effect of TRAIL and the expression of death receptors, Bcl-2, Akt, and p-Akt on four NPC cell lines by MTT and Western blotting, respectively. Small interfering RNAs (siRNAs) targeting Bcl-2 and PI3-K inhibitor (LY294002) were used alone or combined with TRAIL in the cell lines and cytotoxicity was examined by MTT. Apoptosis rates, mitochondrial transmembrane potential, and apoptotic pathway signals were detected by flow cytometric analysis, DiOC6(3) assays, and Western blotting after the various combination treatments on CNE-2, the cell line that was most resistant to TRAIL. RESULTS Although no direct correlation between the sensitivity to TRAIL and the relative expression levels of Bcl-2 and activated Akt was found in the NPC cell lines examined, siRNA mediated the downregulation of Bcl-2 and LY294002-induced inactivation of Akt, increasing the sensitivity of all examined NPC cell lines to TRAIL. Synergistic enhancement of TRAIL-mediated cytotoxicity was observed in combination treatment of Bcl-2 siRNA and LY294002 compared to cells treated with each treatment alone. The synergistic effects were mediated through increased apoptotic signaling of the mitochondrial pathway, as was evident from the more increased mitochondrial depolarization, activation of caspase-9 and caspase-3, and suppression of XIAP. CONCLUSIONS This study provides proof of principle that TRAIL combined with simultaneously targeting the Bcl-2 and Akt signaling pathways may have potential as a novel future treatment strategy for NPC.

Bisphenol A triggers proliferation and migration of laryngeal squamous cell carcinoma via GPER mediated upregulation of IL-6

Bisphenol A (BPA) can be accumulated into the human body via food intake and inhalation. Numerous studies indicated that BPA can trigger the tumorigenesis and progression of cancer cells. Laryngeal cancer cells can be exposed to BPA directly via food digestion, while there were very limited data concerning the effect of BPA on the development of laryngeal squamous cell carcinoma (LSCC). Our present study revealed that nanomolar BPA can trigger the proliferation of LSCC cells. Bisphenol A also increased the in vitro migration and invasion of LSCC cells and upregulated the expression of matrix metallopeptidase 2. Among various chemokines tested, the expression of IL‐6 was significantly increased in LSCC cells treated with BPA for 24 hours. Neutralization antibody of IL‐6 or si–IL‐6 can attenuate BPA‐induced proliferation and migration of LSCC cells. Targeted inhibition of G protein–coupled estrogen receptor, while not estrogen receptor (ERα), abolished BPA‐induced IL‐6 expression, proliferation, and migration of LSCC cells. The increased IL‐6 can further activate its downstream signal molecule STAT3, which was evidenced by the results of increased phosphorylation and nuclear translocation of STAT3, while si–IL‐6 and si‐GPER can both reverse BPA‐induced activation of STAT3. Collectively, our present study revealed that BPA can trigger the progression of LSCC via GPER‐mediated upregulation of IL‐6. Therefore, more attention should be paid for the BPA exposure on the development of laryngeal cancer.

Reconstruction of human oncological tracheal defects with xenogenic acellular dermal matrix

OBJECTIVE This study aimed to explore the effectiveness of xenogenic acellular dermal matrix (xeno-ADM) in tracheal reconstruction. METHOD Two patients were treated with this surgical method to reconstruct the trachea in 2013. The patients were diagnosed with tracheal adenoid cystic carcinoma by histopathological biopsy. The tumor was resected with half of the tracheal circumference and repaired by xeno-ADM. The patients were followed up for 31 and 33 months, respectively. RESULT No infection or tracheal fistula was observed. The grafts were clear. Both patients were successfully decannulated without dyspnea and could breathe and speak without prosthesis. The cervical mobility was not impaired. CONCLUSION Xeno-ADM was successfully used to reconstruct a stable and well-functioning trachea. This surgical method is simple, safe, and effective with fewer complications.

lncRNA-NKILA/NF-κB feedback loop modulates laryngeal cancer cell proliferation, invasion, and radioresistance

Laryngeal cancer is one of the most common head and neck malignant tumors and is commonly resistant to X‐ray‐based radiotherapy. NF‐κB interacting lncRNA (NKILA) has been reported to serve as a tumor suppressor in several cancers through combining with NF‐κB: IκB complex thereby inhibiting NF‐κB activation. Herein, we demonstrated a low NKILA expression in laryngeal cancer and its correlation with shorter overall survival in patients with laryngeal cancer. NKILA serves as a tumor suppressor in laryngeal cancer by suppressing laryngeal cancer cell viability and migration, whereas promoting cell apoptosis; NKILA knockdown reverses the cytotoxicity of X‐ray radiation on laryngeal cancer cells through combining with NF‐κB: IκB complex to inhibit IκB phosphorylation, inhibit p65 nuclear translocation, and finally inhibit NF‐κB activation. NF‐κB binds to the promoter region of NKILA to activate its transcriptional activity, upregulated NKILA then inhibits IκB phosphorylation and NF‐κB activation, thus forming a negative feedback loop to sensitize laryngeal cancer cell to X‐ray radiation. In conclusion, NKILA can serve as a promising agent of enhancing the cytotoxicity of X‐ray radiation on laryngeal cancer and addressing the radioresistance of laryngeal cancer.

Clinical significance of integrin-linked kinase in laryngeal squamous cell carcinoma

OBJECTIVE To investigate the expression of integrin-linked kinase (ILK) and its relationship with clinicopathological parameters in laryngeal squamous cell carcinoma (LSCC). METHODS 116 patients who had previously undergone complete resection of tumor for LSCC were studied retrospectively. The level of ILK expression in tumor tissues and adjacent nontumor tissues were determined by immunohistochemistry. RESULTS Increased expression of ILK was found in 65.5% of cases. The expression of ILK protein was significantly associated with tumor grade (p=0.046), lymph node metastasis (p=0.020), and pTNM stage (p=0.019). Kaplan-Meier survival estimates showed a significant correlation between ILK expression and patient survival rate (log-rank p<0.05). The multivariate survival analysis revealed that N status was statistically significant prognostic factor (p<0.001). Other parameters, such as ILK expression, cannot predict disease prognosis separately. CONCLUSION Increased expression of integrin-linked kinase is associated with lymph node metastases and patient survival rate in laryngeal squamous cell carcinoma. However, it does not appear to be an independent prognostic predictor in LSCC.

Clinical significance of TrkB expression in nasopharyngeal carcinoma.

Recent research has demonstrated that tropomyosin‑related kinase B (TrkB) plays an important role in neuronal survival, differentiation and migration; yet, its specific role in human nasopharyngeal carcinoma (NPC) is unclear. To elucidate its role in NPC, we examined TrkB expression in NPC tissues and cell lines, and investigated the correlation between TrkB expression and prognosis in patients with NPC. Immunohistochemical analysis was performed on NPC specimens from 108 patients with follow-up information. Additionally, reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot analyses were used to determine TrkB expression levels in NPC and noncancerous nasopharyngeal tissues. RT-PCR and western blot analyses were also used to determine TrkB expression levels in 7 NPC cell lines and a nasopharyngeal epithelium cell line. High TrkB expression was significantly correlated with T classification, lymph node metastasis and clinical stage, respectively. Patients with NPC who had high TrkB expression had reduced disease-free survival and overall survival when compared with patients who had low TrkB expression. Multivariate Cox regression analysis revealed that TrkB overexpression was an independent prognostic factor for patients with NPC. Furthermore, TrkB was overexpressed in NPC specimens and cell lines. TrkB expression levels were significantly increased in NPC specimens, and enhanced levels were correlated with a poor prognosis in patients with NPC. These findings suggest that TrkB may contribute to NPC progression and represent a novel prognostic indicator for patients with NPC.