[Phenylhexyl isothiocyanate induces gene p15 demethylation by down-regulating DNA methyltransferases in Molt-4 cells].

This study is to investigate the effect of phenylhexyl isothiocyanate (PHI), which has been proved to be a novel histone deacetylase inhibitor (HDACi) recently, on gene p15 de novo expression in acute leukemia cell line Molt-4, and to further study its potential mechanism. Modified methylation specific PCR (MSP) was used to screen p15-M and p15-U mRNA. DNA methyltransferasel (DNMT1), 3A (DNMT3A), 3B (DNMT3B) and p15 mRNA were measured by RT-PCR. P15 protein was detected by Western blotting. Hypermethylation of gene p15 was reversed and activation transcription of gene p15 in Molt-4 was de novo after 5 days exposure to PHI in a concentration dependent manner. DNMT1 and DNMT3B were inhibited by exposure to PHI for 5 days (P < 0.05). Alteration of DNMT3A was not significant. It is showed that PHI could reverse hypermethylation of gene p15 and transcriptional activation of gene p15 is de novo by PHI. It may result from down-regulating DNA methyltransferases, DNMT1 and DNMT3B, or up-regulating the histone acetylation that allows chromatin unfolding and the accessibility of regulators for transcriptional activation in the p15 promoter.

[Effect of hyoid suspension with uvulopalatopharyngoplasty in the treatment of obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To discuss the methodology and therapeutic effect of hyoid suspension in association with uvulopalatopharyngoplasty (UPPP) in the treatment of severe obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: Sixty-nine patients with severe OSAHS (apnea hyponea index, AHI > 30) were treated with hyoid suspension and UPPP. Sixty-one patients were followed for 6 months (48 of them for 12 months). Polysomnogram (PSG) tests were performed and an Epworth sleepiness scale (ESS) was recorded preoperatively and postoperatively in these patients. RESULTS: After the surgery,the snoring of the patients disappeared or was alleviated to varing degrees. Eighteen patients underwent fiberoptic nasopharyngolaryngoscopic examination. Twelve of them showed palatopharyngeal and glossopharyngeal stenosis was improved 6 months after surgery. Six patients showed no change, but had no glossoptosis. Fourteen patients underwent fiberoptic nasopharyngolaryngoscopic examination 1 year after surgery, with no recurrence of the stenosis being found. A decrease of 50% in the AHI was considered effective, and in patients the effective rate was 78.7% (48/61) 6 months after the operation and 75.0% (36/48) 1 year after the operation. The average AHI decreased from 44.8 to 15.1 and 17.2, and the minimum arterial oxygen saturation average increased from 0.512 to 0.880 and 0.730. Matching t tests were utilized and the results of follow-up indicated that there was a significant improvement in the indexes in those cases which could be followed up (P < 0.01). The average of the ESS was 6.7 six months after operation and 7.2 one year after operation, with a significant decrease compared to the preoperative (16.6) data (P < 0.01). CONCLUSIONS: Modified hyoid suspension in association with UPPP has the advantage of a simple operation, short hospitalization and less expense, and the effect of the operation was significant. Patients with palatopharyngeal and glossopharyngeal stenosis should be chosen for this operation.

[Phenylhexyl isothiocyanate induces gene p15 re-expression by regulating histone methylation and DNA demethylation in Molt-4 cells].

This study was aimed to investigate the regulatory effect of phenylhexyl isothiocyanate (PHI) on methylation of histone H3K4, H3K9 and demethylation of p15 gene in acute leukemia cell line Molt-4, and to explore the possible mechanism inducing re-expression of silent gene. The methylation status of histone H3K4, H3K9 and the expression of P15 protein in the Molt-4 cells treated with PHI were detected by Western blot; the methylation status of p15 gene in the Molt-4 cells before and after treatment with PHI was determined by methylation specific polymerase chain reaction (MSP); the expression level of p15 gene mRNA in Molt-4 cells treated with PHI was assayed by semiquantitative reverse transcription-PCR. The results indicated that the PHI could increase methylation of histone H3K4 and decrease methylation of histone H3K9 in concentration-and time-dependent manners. After treatment of Molt-4 cells with PHI for 5 days, the methylation of p15 gene was reduced, the significant hypermethylation of p15 gene was reversed, the silenced p15 gene re-expressed; the expressions of p15 mRNA and P15 protein were enhanced in concentration-dependent manner. It is concluded that probably through specifically regulating the methylation level of histone H3K4 and H3K9, the PHI causes the changes of chromosome space structure and results in the demethylation of CPG island in p15 gene, thereby induces the re-expression of p15 gene which was silenced.

[Dynamic observation of applying repairing laryngeal mucosal defect with heterogeneous acellular dermal matrix].

OBJECTIVE: To study the clinical effect of heterogeneity (cattle) acellular dunal matrix in repairing mucosa defect in laryngeal surgery. METHODS: Eighteen cancer patients with mucosa defect in central vocal area accepted treatment with heterogeneity acellular dunal matrix after surgery. There were two methods to repair mucosa defect. One was simple use of acellular dunal matrix, the second was combined use of acellular dunal matrix and muscle lamella or muscle and tendon film lamella. 18 cases had cancer in central vocal area: T2N0M0 (8), T3N1M0 (5), T3N2M0 (4), T4N2M0 (1). All were squamous cell carcinoma. Ten cancer patients accepted radiation after surgery. The radiotherapy volume was 60-80 Gy. After the operation, the patients were checked by fibrolaryngoscope four or five times after half a year, observing the dynamic development. RESULTS: All 18 patients were healed, rechecked by endoscope after 0.5-6 months, heterogeneity acellular dunal matrix mingled with mucosa within 30-60 d, no allergy and irritation were found. The laryngeal function, including breathing, pronouncing and swallowing, was recovered. The survival rate (1 year) was 100%, and 10 patients survived after 2 years. After radiotherapy, the process of recovery was not affected. CONCLUSIONS: Heterogeneity acellular dunal matrix can be easily obtained and it is a new method to repair mucosa defect. The operative procedure is easy to perform and worthwhile to use clinically.