RASSF2 can bind directly to K-Ras and function as a negative effector of Ras protein. RASSF2A is the only isoform of RASSF2 that contains CpG islands in its promoter and it has been reported to be inactivated by its promoter methylation in several human cancers. In the present study, we investigated the correlation of RASSF2A expression with its promoter methylation in nasopharyngeal carcinoma (NPC). Expression of RASSF2A was downregulated in 80% (4/5) of NPC cell lines. Decreased RASSF2A expression was also observed in NPC primary tumors compared with normal nasopharyngeal epithelia. Promoter methylation of RASSF2A could be detected in all the RASSF2A-silenced cell lines (4/5) of the NPC cell lines and 50.9% (27/53) of primary tumors, but not in any of the normal epithelia. RASSF2A-methylated cases showed a significantly lower level of RASSF2A expression than unmethylated cases. Loss of RASSF2A expression can be greatly restored by the methyltransferase inhibitor 5-aza-dC in NPC cell lines. In addition, patients with methylated RASSF2A presented a higher frequency of lymph node metastasis (p < 0.05). Ectopic expression of RASSF2A in RASSF2A-silenced and -methylated NPC cell line CNE2 shows that RASSF2A could inhibit cell cycle progression, colony formation and cell migration, which provided further evidence that RASSF2A is a candidate tumor suppressor gene. In conclusion, RASSF2A, a candidate tumor suppressor gene (TSG), is frequently inactivated by its promoter methylation and this aberrant methylation correlates with lymph node metastasis in NPC. ' 2006 Wiley-Liss, Inc.

Radiation-induced sarcoma in the head and neck (RISHN) is a rare condition whose clinical presentation and management remain difficult because of its low incidence. In this retrospective study, we analyzed the symptoms, diagnosis, and the treatment of 16,634 patients with head and neck disease, who received radiotherapy between 1960 and 2010 at the Affiliated Tumor Hospital and its predecessor, Guangxi Medical University, China. Among these patients, 16 with a first tumor of nasopharyngeal carcinoma (NPC) and 1 with squamous carcinoma of the tongue met the criteria of RISHN in the head and neck. Our epidemiological data showed that the incidence of RISHN rose from 0.06 to 0.17% from 1960 to 2010; the 3-year overall survival rate was 19.1%, and 3-year disease-free survival rate was 11.1%. The mean latency (SD) period was 93.2 (33) months. Based on the experiences at our institution, we suggest that RISHN is a rare complication after radiotherapy for head and neck tumors, especially NPC. Owing to its low incidence, it should not be a major factor affecting decisions about radiotherapy. Nevertheless, there may be a possibility of increasing incidence of RISHN after radiotherapy of NPC, as shown in our epidemiological results. Given the poor prognosis of RISHN, this possibility should be taken into serious consideration before determination of high-dose radiotherapy for patients with NPC and other head and neck tumors.

We report the emerging role of microRNA (miRNA) deregulation associated with activation of an oncogene SOX4 (a member of the SRY-related HMG-box) in esophageal carcinoma. Paired esophageal cancer and adjacent non-tumor tissues were obtained from 42 patients who underwent primary surgical resection for esophageal cancer. Experiments such as real-time PCR, western blot analysis, luciferase-reporter assay, cell proliferation and colony formation assays, in vitro migration and invasion assays, and a wound-healing assay were performed to determine the effects of miR-129-2. We found that SOX4 expression was elevated (P<0.005) in esophageal tumors (n=42) when compared with its expression in the controls (n=42). Compared with the normal esophageal tissues, the expression of miR-129-2 was downregulated in 27 of 31 primary esophageal tumors, while the expression of SOX4 was upregulated (P<0.001). Restoration of miR-129-2 by transfection with an miRNA expression plasmid led to a decrease in SOX4 expression, which was accompanied by reduced migration and proliferation of the cancer cells. These results suggest that aberrant expression of SOX4 is associated with repression of miR-129-2, and restoration of miR-129-2 suppresses the migration and proliferation of esophageal cancer cells. Our results demonstrated that the deregulation of miR-129-2 leads to aberrant SOX4 expression, presenting a new paradigm in which the restoration of miRNA suppresses its oncogenic target in esophageal cancer.

The normal range values of inner ear radial lines were measured and formulated, of which CL was 8.1-9.59 mm and CH was 3.28-3.90 mm. According to inner ear morphology and the normal values measured above, 61 cases of incomplete partition-type II (IP-II) and a high percentage (27/110, 24.5%) of hypoplasia of cochlea (HC) were diagnosed. The HC group was further divided into 1-turn, 1.5-turn, and 2-turn sub-groups, which had CDL of 15.98 ± 1.48 mm, 21.36 ± 0.96 mm, and 26.56 ± 0.60 mm, respectively.

MicroRNAs are endogenous small RNAs with a high degree of conservation, participating in a variety of vital activities. In present study, to explore the effect of microRNAs on 3T3-L1 adipocyte differentiation and adiponectin expression, the adipo-related microRNAs were screened and identified by micorRNA microarray. The highly expression plasmid of microRNA-21 with obvious expression up-regulation (miR-21) and its anti-sense (miR-21 inhibitor) were constructed and transfected into 3T3-L1 preadipocytes. The effect of miR-21 on 3T3-L1 adipocyte differentiation was observed, and the protein and mRNA expression level of adiponectin and AP-1 were analyzed. Results showed that, the expression profiles of microRNAs significantly changed during 3T3-L1 adipocyte differentiation. The expression of miR-21 was obviously up-regulated. miR-21 could significantly promote adipocyte differentiation, increase adiponectin mRNA and protein expression, while decrease AP-1 protein level. Meanwhil, miR-21 inhibitor blocked the effects of miR-21 mentioned above. The overexpression of AP-1 could absolutely reverse the stimulatory effect of miR-21 on adiponectin. miR-21 plays an important role in regulating adipocyte differentiation and adiponectin expression by inhibiting AP-1 expression.

Currently, there are no satisfactory biomarkers available to screen for nasopharyngeal carcinoma (NPC). Nitric oxide (NO), produced by inducible nitric oxide synthase (iNOS), has been suggested to cause nitrative and oxidative stress, leading to the accumulation of 8-nitroguanine (8-NitroG) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the subsequent transversion mutation of DNA. The aim of this study was to evaluate iNOS expression and the status of nitrative and oxidative stress in NPC. Fifty-nine cases of NPC and 39 cases of chronic nasopharyngitis were investigated to examine the expression of iNOS and the formation of 8-NitroG and 8-OHdG, using double-immunofluorescent staining. The statistical differences in immunoreactivities were analyzed using the Mann-Whitney test. Thirty-six patients from the 57 cases of NPC and 36 healthy controls were investigated to examine the level of serum 8-OHdG, using enzyme-linked immunosorbent assay (ELISA). The statistical differences were analyzed using a t test. Strong DNA lesions were observed in the cancer cells of NPC patients. All cases of NPC were positive for 8-NitroG and 8-OHdG, and 54 (94.7%) were positive for iNOS. NPC samples exhibited significantly more intense staining for 8-NitroG, 8-OHdG and iNOS than those of chronic nasopharyngitis (P < 0.05, respectively). The mean value of serum 8-OHdG in the 36 NPC patients was 0.538 ± 0.336 ng/ml compared to 0.069 ± 0.059 ng/ml for the healthy controls. The difference in the serum levels of 8-OHdG between the NPC patients and controls was statistically significant (P < 0.05). Our present findings suggest that pathological stimulation of nasopharyngeal tissue, caused by bacterial, viral or parasitic inflammation, may lead to nitrative and oxidative DNA lesions, caused by NO. This may contribute to the cause and development of NPC. Thus, 8-NitroG and 8-OHdG could be potential biomarkers for evaluating the risk of NPC. Better understanding of the molecular mechanisms underlying nitrative and oxidative DNA damage may provide clues to molecular targets for new approaches of NPC prevention.

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Background/Aims: Nasopharyngeal carcinoma (NPC) is a distinctive type of head and neck cancer with the highest incidence in South China. Previous studies have proved that matrine, a main alkaloid isolated from Sophora flavescens Ait, has antitumor activity against NPC. However, the effect is not so pronounced and the underlying mechanism remains largely unclear. Here we investigated whether 14-thienyl methylene matrine (YYJ18) that was derived from matrine could exert more effective suppression activity on NPC, along with the underlying mechanism. Methods: NPC cell lines CNE1, CNE2 and HONE1 were treated with YYJ18. Cell proliferation and apoptosis were determined by MTT assay and flow cytometry. Activation of mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathways were determined by Western blotting and quantitative RT-PCR. Results: YYJ18 remarkably inhibited proliferation and induced apoptosis of all three NPC cell lines in a dose-dependent manner, especially in CNE2 cells. Furthermore, YYJ18 treatment significantly suppressed phosphorylation of p38 in CNE2 cells, but upregulated phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2) and Akt. Next, alterations in downstream signaling were found, including activation of BCL2-associated X protein (Bax), caspase-3 and inactivation of B-cell CLL/lymphoma 2 (Bcl-2). Conclusion: We demonstrate the potent inhibitory effects of 14-thienyl methylene matrine on NPC cells for the first time, which could be mediated by modulation of MAPK and PI3K/Akt pathways.