Metadherin regulation of vascular endothelial growth factor expression is dependent upon the PI3K/Akt pathway in squamous cell carcinoma of the head and neck.

Our previous study indicated overexpression of metadherin (MTDH) is an adverse prognostic factor in squamous cell carcinoma of the head and neck (SCCHN) and promotes SCCHN cell proliferation and invasion. However, its mechanism remains unclear. Recent studies have indicated that MTDH is a cancer-metastasis-associated molecule that participates in the process of angiogenesis. Therefore, the study is aimed to investigate that whether vascular endothelial growth factor (VEGF), as one of the most potent proangiogenic cytokines, is regulated by MTDH and the role of the phosphatidylinositide 3-kinases/Protein Kinase B (PI3K/Akt) pathway in this process of regulation and the clinical significance of both MTDH and VEGF in SCCHN.Immunohistochemistry was used to assay the expression of MTDH and VEGF in a cohort of 189 SCCHN patients with intact follow-up information. The expression of MTDH was then upregulated or inhibited by lentivirus-mediated MTDH Complementary deoxyribonucleic acid or MTDH short hairpin ribonucleic acid (shRNA) to observe the resulting alterations in VEGF expression and the PI3K/Akt signaling pathway in SCCHN cell lines. In addition, the PI3K/Akt pathway was modulated to observe the resulting changes in the MTDH-mediated expression of VEGF.The immunohistochemistry data showed that MTDH expression is positively correlated with VEGF expression in SCCHN tissues. Moreover, the overexpression of MTDH in SCCHN Tu686 and 5-8F cells led to increases in the expression of VEGF, and this effect was accompanied by activation of the PI3K/Akt pathway. Conversely, shRNA-mediated knockdown of MTDH led to decreased VEGF expression. In addition, inhibition of the Akt signaling pathway reversed the upregulation of VEGF resulting from MTDH overexpression. Moreover, the survival analysis revealed that VEGF is an independent prognostic factor, and a combined survival analysis based on both MTDH and VEGF showed synergistic effects in the prognosis evaluation of SCCHN patients.The findings of the present study demonstrate that MTDH regulates the expression of VEGF via the PI3K/Akt signaling pathway, indicating the potential role of the MTDH-mediated activation of VEGF signaling pathway in SCCHN angiogenesis and metastasis.

[Irradiation induced epithelial-mesenchymal transition in nasopharyngeal carcinoma in vitro].

OBJECTIVE: To investigate the irradiation induced epithelial-mesenchymal transition (EMT) in nasopharyngeal carcinoma (NPC) in vitro. METHODS: NPC CNE-2 cells with radioresistance (CNE-2-Rs) were established by exposure to gradiently increased dose of irradiation. CCK-8 cell viability kits, colony formation assay and fluorescence-activated cell sorting analysis were used to confirm the capacity of radioresistance of CNE-2-Rs cells. Invert microscope was used to monitor the morphological changes and western blot was applied to detect the expression of epithelial cell marker E-cadherin and mesenchymal cell marker Vimentin during the phase of CNE-2 exposure to irradiation. RESULTS: Irradiation exposure successfully induced the radioresistance of CNE-2 cells. After exposed to irradiation, the survival rate in CNE-2-Rs was higher than that in CNE-2 by CCK-8 assays. No significant difference of proliferation ability was observed between the CNE-2 and CNE-2-Rs pre-radiotherapy, but a higher proliferation ability in the CNE-2-Rs post-radiotherapy. By using the colony forming assay, the parameters of CNE-2 and CNE-2-Rs in multi-target single-hit and linear quadratic model were obtained and the data demonstrated that parameters mean lethal dose (D0) , quasi-thres hold dose (Dq) , surrival fraction in 2Qy (SF2) and mean inctivation dose (MID) value increased, α and α/ß value decreased (P < 0.05) . At the same time, the CNE-2-Rs cells showed higher percentage of cells in S and G2 phase (P < 0.05) . In terms of biomorphology, CNE-2-Rs cells were more narrow, long strips or fusiform shapes, stretched out tentacles, and the contacts between them were loosened. When radiation dose accumulated to 24 Gy, an over-expression of Vimentin was observed in treated cells, while E-cadherin was down-regulated (P < 0.01) . CONCLUSIONS: NPC cells present with typical morphorlogical and biomolecular changes of EMT during exposure to irradiation, indicating the potential critical roles of EMT in the malignant behavior of radioresistance in NPC.

[EphA2 mediated vascular endothelial growth factor expression via the p38 MAPK signaling pathway in squamous cell carcinoma of the head and neck].

OBJECTIVE: To investigate the regulatory effect of erythropoietin-producing hepatocellular receptor (EphA2) on the expression of VEGF protein, a pro-angiogenic factor, via p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway in squamous cell carcinoma of the head and neck(SCCHN) in vitro. METHODS: SCCHN Tu686 cells were transfected with EphA2 overexpression vector pEGFP-N1-EphA2. Western blot was used to detect the expression of p38 MAPK and enzyme-linked immunosorbent assay (ELISA) was applied to assay of VEGF. SB203580 as a inhibitor of p38 MAPK signaling pathway was used. RESULTS: The expression of VEGF protein was significantly up-regulated in Tu686 cells transfected with EphA2 overexpression vector (535.31 ± 45.71) pg/ml, when compared with Tu686 cells transfected with empty vector (400.99 ± 33.50) pg/ml and Tu686 cells with no transfection (385.30 ± 33.50) pg/ml (F = 17.091, P < 0.01). The expression of phosphorylated p38 MAPK was obviously increased in Tu686 cells with EphA2 overexpression. SB203580 inhibited the expressions of VEGF and phosphorylated p38 MAPK proteins in Tu686 cells with EphA2 overexpression. CONCLUSION: EphA2 can regulate the expression of VEGF protein and stimulate p38 MAPK signaling pathway.

[Expression of astrocyte elevated gene-1 protein and its clinical significance in laryngeal squamous cell carcinoma].

OBJECTIVE: To assess the protein expression of astrocyte elevated gene-1 (AEG-1) in tissue specimens of laryngeal squamous cell carcinoma (LSCC), and to correlate its expression with clinicopathological parameters and prognosis in patients with LSCC. METHODS: RT-PCR was used to assay the expression of AEG-1 mRNA in 13 pairs of LSCC tissues and their corresponding noncarcinoma epithelia. Immunohistochemistry was performed on paraffin-embedded tissue specimens to investigate the protein expression of AEG-1 in 88 cases of LSCC specimens and 15 cases of adjacent epithelial samples. RESULTS: The expression of AEG-1 mRNA was significantly increased in LSCC tissues compared to adjacent noncarcinoma epithelial tissues (0.81 ± 0.17 vs. 0.23 ± 0.10;t = 10.337, P < 0.001). Meantime, the positive rate of AEG-1 protein in 88 cases of LSCC was 87.5% (77/88). However, 15 cases of adjacent noncarcinoma epithelial merely demonstrated negative or mild expression of AEG-1 protein. AEG-1 overexpression was closely correlated with T stage (χ(2) = 6.289, P = 0.018), clinical stage (χ(2) = 11.049, P < 0.01), metastasis (χ(2) = 20.859, P < 0.01) and recurrence(χ(2) = 13.459, P < 0.01). The overall survival rates of patients with AEG-1 overexpression and low expression were 35.9% and 86.4%, respectively (χ(2) = 23.409, P < 0.01). Multivariate Cox regression analysis revealed that AEG-1 expression was an independent prognostic factor (P = 0.016). CONCLUSION: AEG-1 protein may play a critical role in the initiation and progression of LSCC, implicating its predictive value in prognosis.

[Expressions and clinical significance of high mobility group box-1 mRNA and protein in laryngeal squamous cell carcinoma tissues and serum].

OBJECTIVE: To investigate the mRNA and protein expressions of high mobility group box-1 (HMGB1) in the tumor tissues and sera of patients with laryngeal squamous cell carcinoma (LSCC) and their clinical significance. METHODS: Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot were used to detected the expressions of HMGB1 mRNA and protein in the tumors and adjacent normal epithelial tissues in 30 patients with LSCC. Serum HMGB1 protein levels in the patients with LSCC and in 10 healthy volunteers were detected with enzyme-linked immunosorbent adsorption experiment (ELISA). RESULTS: RT-PCR demonstrated that the mean relative mRNA expression levels of HMGB1 (HMGB1/GAPDH) in LSCC tissues and in adjacent normal epithelial tissues were 1.25 ± 0.12 and 0.32 ± 0.04, respectively (t = 40.27, P < 0.05). Western blot revealed that the mean relative protein expression levels of HMGB1 (HMGB1/ß-actin) were 1.29 ± 0.10 and 0.34 ± 0.03 (t = 49.84, P < 0.05), respectively. Both mRNA and protein expression levels of HMGB1 were associated with T stage, clinical stage, lymph node metastasis status and smoking (all P < 0.05), but no significant correlation with age, alcohol consumption and primary tumor grade and location (all P > 0.05). Mean serum HMGB1 protein levels in patients with LSCC and healthy volunteers were (24.80 ± 14.08) ng/ml and (23.58 ± 14.69) ng/ml (t = 0.37, P > 0.05). CONCLUSIONS: Both mRNA and protein expressions of HMGB1 were obviously elevated in LSCC, which were associated closely with T stage, clinical stage and lymph node metastasis.

[Determination of safflor yellow A by RP-HPLC and resources quality comparison in Carthamus tinctorius].

OBJECTIVE: To provide the basis for establishing evaluation criterion, selecting good strains and carring out good agricultural practice of the crude drug. METHOD: Representative 22 varieties of Carthamus tinctorius were selected and cultivated in different ecological localities and different years. And the content of safflor yellow A in their corollas were measured by RP-HPLC to compare the differences and their genetic stabilities among varieties. RESULT: The range of of safflor yellow A content was 0.70%-1.85% which were varied among varieties (P < 0.01). The content of safflor yellow A in varieties Yutai Honghua, Hefei Honghua, Rucheng Honghua were higher than in others. CONCLUSION: The effective compound safflor yellow A in C. tinctorius was one of the main quality evaluation criterions. Varieties Yutai Honghua, Hefei Honghua and Rucheng Honghua were good resources.

[Histological and morphological studies on the rhizomes of Curcuma].

OBJECTIVE: To provide some new evidences for the identification of medicinal materials of Curcuma. METHOD: Microscopic observation was made to characterize the rhizomes of Curcuma. RESULT AND CONCLUSION: There were no obvious histological and morphological differences among the rhizomes of Curcuma. The distribution of oil cells and vascular bundles as well as the number and diameter of xylem vessels were considered to be the distinguishing features of their rhizomes.