Telomerase reverse transcriptase promotes the proliferation of human laryngeal carcinoma cells through activation of the activator protein 1.

TERT is the main functional unit of telomerase, which maintains telomere length and chromosome structure stability. TERT has been shown to act as a key factor in various biological processes, such as cell proliferation, via uncharacterized mechanisms. We transfected HEp-2 laryngeal carcinoma cells with a TERT overexpressing adenovirus (Ad-TERT) and TERT shRNA silencing adenovirus (Ad-sh-TERT), and examined the effect on TERT and the AP-1 transcription factor subunits c-Fos and c-Jun using RT-PCR and western blot analysis. TERT mRNA expression was quantified using RT-PCR in 24 human laryngeal carcinoma samples, and TERT protein co-expression with AP-1 was investigated in a human laryngeal carcinoma tissue microarray using quantum-dot based immunofluorescence. The effect of specific ERK and p38 inhibitors on ERK, p38, c-Jun and c-Fos phosphorylation was investigated in TERT-overexpressing HEp-2 cells. TERT overexpression led to increased TERT, c-Jun and c-Fos mRNA and protein expression and increased cell proliferation, while TERT silencing had the opposite effects. TERT mRNA expression levels were positively correlated with c-Fos and c-Jun mRNA in human laryngeal carcinoma tissue. TERT and AP-1 protein were expressed at high levels and positively correlated in laryngeal carcinoma tissues. Treatment of TERT-overexpressing HEp-2 cells with specific p38 and ERK inhibitors indicated that TERT modulates the expression and phosphorylation of the AP-1 subunits c-Jun and c-Fos through the p38 and ERK signaling pathways. In conclusion, the results of this study indicate that TERT is capable of promoting cell proliferation via activation of the AP-1 subunits, c-Jun and c-Fos, in laryngeal carcinoma cells.

Indole-3-carbinol inhibits cell proliferation and induces apoptosis in Hep-2 laryngeal cancer cells.

Indole-3-carbinol (I3C) is an active component of cruciferous vegetables and markedly inhibits the growth of a variety of tumors. However, its role in laryngeal cancer remains obscure. The aim of the present study was to elucidate the possible mechanisms whereby I3C influences Hep-2 laryngeal cancer cell proliferation and apoptosis. Treatment with I3C dose-dependently and significantly inhibited Hep-2 cell proliferation, and at doses of 100 and 150 µM, I3C induced cell morphological changes and promoted apoptosis. Following treatment of Hep-2 cells with I3C, we found that the protein expression of phosphatidylinositol-3-kinase (PI3K) p110α, PI3K p110ß, PI3K class III, p-PDK1, Akt, p-Akt and the downstream signaling proteins p-c-Raf and GSK3-ß were significantly downregulated. Additionally, tumor-bearing mouse models were constructed using BALB/c nude mice. The mice were subdivided into groups: pretreated with I3C, or treated with I3C or an untreated control group. After 8 weeks, mice pretreated or treated with IC3 developed smaller tumors compared to the untreated control group, and the protein expression of PI3K p110α, PI3K class III, Akt, p-Akt and the downstream signaling proteins p-c-Raf and GSK3-ß in the tumors were significantly downregulated. Furthermore, no harmful side effect were observed in the heart, liver and kidney of the I3C-treated nude mice. In conclusion, I3C inhibited proliferation and induced the apoptosis of laryngeal tumor cells both in vivo and in vitro, and exhibited low toxicity to normal cells. The inhibitory effects noted with I3C treatment may depend on decreased phosphatidylinositol-3 kinase/serine-threonine kinase (PI3K/Akt) expression. This approach may be applied to the clinical treatment of laryngeal tumors and in drug screening.

[P-selectin gene -2123 polymorphism in children with Henoch-Sch-nlein purpura].

OBJECTIVE: To investigate whether P-selectin gene -2123 polymorphism is associated with the pathogenesis of Henoch-Sch-nlein purpura (HSP) in children. METHODS: Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) is used to identify the distribution of allele and genotype frequencies of P-selectin gene promoter -2123 polymorphism in 86 children with HSP (including 40 cases of purpura nephritis) and 70 healthy controls. RESULTS: Compared with the healthy controls, the frequencies of GG genotype and G allele of P-selectin promoter -2123 in children with HSP increased significantly (P<0.05). There were no significant differences in P-selectin promoter -2123 genotype and allele frequencies between the patients with and without nephritis. CONCLUSIONS: P-selectin gene promoter -2123 polymorphism appears to be associated with the pathogenesis of HSP in children.

[Polarization and immune regulation of TH cells in children with bronchial asthma].

OBJECTIVE: To study the polarization and immune regulation of TH cells in patients with bronchial asthma. METHODS: Thirty-eight hospitalized children with bronchial asthma (ranging from 4-12 years old) and 29 age-matched healthy children (Control group) were enrolled in this study. Serum IL-2 and IFN-gamma levels were detected using ELISA. The percentage of TH1 and TH2 cells was detected by intracellular staining. RESULTS: The serum levels of IL-2 (15.94 +/- 3.07 microg/L) and IFN-gamma (487.2 +/- 43.6 pg/mL ) in asthmatic patients were significantly lower than those in the Control group (24.73 +/- 4.37 microg/L and 654.07 +/- 14.64 pg/mL respectively; P < 0.01). The percentage of TH1 in asthmatic patients decreased significantly compared with that in the Control group [(11.24 +/- 2.43)% vs (16.67 +/- 2.73)%; P < 0.01]; in contrast, the percentage of TH2 increased compared with that in the Control group [(19.85 +/- 4.46)% vs (16.08 +/- 6.17)%; P < 0.05]. CONCLUSIONS: The serum levels of IL-2 and IFN-gamma, and the number of TH1 cells decreased in asthmatic patients. The decreased number of TH1 cells and the ratio of TH1/TH2 suggest an abnormal polarization of TH1 and TH2 cells. The changes may be associated with the inhibition of cellular immune function in asthmatic patients.