Effects and Significance of Dicliptera chinensis Polysaccharide on the Expression of Transforming Growth Factor ß1/Connective Tissue Growth Factor Pathway in the Masseter and Head and Neck Skin of Rats With Radiation-Induced Fibrosis.

PURPOSE: To investigate whether Dicliptera chinensis polysaccharide (DCP) can alleviate radiation-induced fibrosis of masseter and head and neck skin. METHODS: SD rats were divided into the control, the irradiation (IR), the IR + low dose DCP (200 mg/kg), and the IR + high dose DCP (400 mg/kg) groups. The head and neck of rats in the last 3 groups received a single dose of 18 Gy X-ray. At 1st, 2nd, 4th week (w) after radiation, haematoxylin and eosin staining were performed on masseter and skin to observe the histopathological changes; immunohistochemistry staining was performed to observe the pathological changes of the skin; Masson staining was performed on masseter and skin to observe the collagen deposition; western blot analysis was used on masseter to calculate the relative transforming growth factor ß1 (TGF-ß1), connective tissue growth factor (CTGF) expressions; ELISA was used to detect the contents of TGF-ß1 and CTGF in skin and the contents of type I and type III collagens in masseter and skin. RESULTS: In terms of skin, compared to the IR group, the IR + high-dose DCP group exhibited relatively smaller changes in skin structure, lower levels of TGF-ß1 and CTGF; thinner skin thickness was observed at the 4th w after radiation; and the positive rates of collagen fibre and the optical densities of type I and type III collagens were lower at the 2nd and 4th w. For the masseter, compared to the IR group, the morphological changes were improved and the expression levels of TGF-ß1 and CTGF proteins decreased in the 2 DCP dose groups at 2nd and 4th w. CONCLUSION: DCP can reduce the formation and accumulation of type I and type III collagens after IR and ameliorate radiation-induced fibrosis of masseter and skin by down-regulating the expressions of TGF-ß1 and CTGF.

Dicliptera chinensis-derived polysaccharide enhanced the growth activity of submandibular gland cells in vitro after radiotherapy.

Objective: Radiotherapy for head and neck can damage the salivary gland cells, which can easily result in xerostomia. No effective treatment for radiation-induced salivary gland dysfunction currently exists. Thus, we aimed to study the protective effect of Dicliptera chinensis polysaccharides (DCP) on the prevention of submandibular gland (SMG) cell damage caused by radiotherapy in Sprague-Dawley rats. Design: Mechanical enzyme digestion was used to extract primary rat SMG cells. A radiation injury model was established by treating these cells with a dose of 8 Gy, followed by intervention using different DCP concentrations. The cell counting kit 8 assay was used to determine the inhibition rate of SMG cells in each group. The rates of apoptosis and cell cycle progression were detected using flow cytometry. Expression of the Mre11/Rad50/Nbs1 complex (MRN) was detected using western blotting. Results: DCP increased the proliferation of SMG cells after irradiation, and cell growth activity positively correlated with polysaccharide concentration. Flow cytometry analysis of SMG cell apoptosis revealed that DCP markedly reduced the total apoptosis rate after irradiation, especially the early apoptosis rate. Cell cycle results suggested that DCP reduced the number of cells in the S and G2 phases after irradiation and alleviated the S and G2 blocks. Western blot results indicated that the expression of Mre11, Rad50, and Nbs1 decreased in the radiation-injured group, whereas their expression increased after DCP treatment. Conclusions: DCP can protect the rat SMG cells after radiation and be used as a protective agent against salivary gland cell damage caused by radiotherapy.

Effect of silencing SSB1 gene on the expression of NBS1 in irradiated rat submandibular gland cells.

The salivary gland (SGS) is a kind of organ vulnerable to ionizing radiation. Radiotherapy is an important treatment for head and neck tumors, but in the process of radiotherapy, tumor cells will be injured by radiation to a certain extent. Infrared-induced DNA double-strand break (IR-DSBs) is one of the most serious DNA damage. DNA repair proteins such as Nymegan rupture syndrome protein 1 (NBS1) play a key role in the identification and repair of DNA damage. but the interaction between SSB1 and NBS1 has not been elucidated. In this study, we irradiated rat submandibular gland (SMG) cells, which were either infected with a rAdE5-SSB1-1p2-shRNA recombinant adenovirus to silence SSB or a control virus, to explore the effect of IR on the expression NBS1 in the absence of SSB. Our results showed that the SSB1 mRNA transcripts and protein expression of SSB1 and NBS1 initially increased and decreased later with increased doses. The relative expression reached the highest levels when the SMG cells were irradiated with 2Gy of IR. Silencing the SSB1 gene suppressed the expression of both SSB1 and NBS1 regardless of irradiation. The expression of NBS1 decreased when the SSB1 gene was silenced. We concluded that IR affected the expression of both SSB1 and NBS1 and there is a synergistic effect on IR-induced NBS1 suppression and DSBs repair in SMG cells. These observations shed light on further investigation and elucidation of IR-caused DNA repair mechanisms.

A study on oral health status and behaviors of Chinese college students / 中国学校卫生

Abstract@#Oral diseases are the most important public health problems that have not received due attention, especially among college students. Based on the analysis of literatures on oral health status and behaviors of college students, the paper systematically summarizes the relevant research situation, points out the existing problems. Suggestions and countermeasures, such as attaching importance to the investigation and research on oral health of college students, improving the quality and level of scientific research on oral health of college students, exploring more effective comprehensive intervention measures for oral diseases and oral health education, should be implemented as projects are put forward, so as to provide basis for improving the oral health status of Chinese college students and promoting relevant research level.

Protein overexpression of toll-like receptor 4 and myeloid differentiation factor 88 in oral squamous cell carcinoma and clinical significance.

Oral squamous cell carcinoma (OSCC) is the most common type of malignancy of the head and neck. In the present study, the expression of Toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88) was evaluated in 55 OSCC tissues and their corresponding adjacent tissues using immunohistochemistry and reverse-transcription quantitative PCR. The results indicated that TLR4 and MyD88 were overexpressed in OSCC. Furthermore, high expression of MyD88 was negatively associated with a poor degree of differentiation, recurrence and metastasis of the tumor and was positively associated with underlying disease, including hypertension, heart disease and diabetes mellitus. Furthermore, high expression of TLR4 was positively associated with a long growth time of the tumor. In conclusion, the present study evaluated the expression levels of TLR4 and MyD88 in OSCC, as well as the association between them and clinicopathological factors, to provide markers for the prognosis and treatment of OSCC. These two genes may serve as biomarkers to optimize OSCC treatment, setting a new direction for stratifying patients and developing precise and personalized treatment regimens; the TLR4/MyD88 pathway may serve as a potential therapeutic target in the future.

Expression of beta adrenergic receptor in oral squamous cell carcinoma and its significance to the prognosis.

The aim of this study was to detect the expression of ß-AR (Beta Adregenic Receptor) in Oral squamous cell carcinoma (OSCC), para-cancerous and normal oral mucosa and to investigate the relationship between the expression intensity and the characteristics and prognosis of oral cancer. 100 cases of OSCC were collected; 20 cases of paraneoplastic tissues and 10 cases of normal oral mucosa were taken as control. The expression of ß-AR was detected by immunohistochemical method and the average optical density determination using Image J software. Finally, the difference of ß-AR expression and the correlation with the clinicopathological factors were analyzed statistically. The expression of ß-AR in OSCC was higher than that in paracarcinoma and normal mucosa (P<0.01). The expression intensity of ß1, ß2-AR in preoperative lymph node metastasis group was higher than that in patients without lymph node metastasis (P<0.01). The expression intensity of ß3-AR was not related to pathological grade and tumor size (P>0.05). ß1 and ß2-AR in early stage of OSCC were higher than those in early stage (P<0.05). Lymph node metastasis, recurrence, TNM clinical stage, and the expression intensity of ß1-AR all had an effect on the cumulative survival rate. All the ß1, 2, 3-AR were expressed in OSCC. ß1 and ß2-AR were involved in lymphatic metastasis and had influence on clinical staging. Metastasis, recurrence, TNM stage and expression of ß1-AR had an effect on the cumulative survival rate of tumor. The expression of ß3-AR in OSCC was not associated with the pathological grades and tumor growth.

Head and neck cancer radiosensitization by the novel poly(ADP-ribose) polymerase inhibitor GPI-15427.

BACKGROUND: In this study, we tested the ability of a novel poly(adenosine diphosphate ribose) polymerase (PARP) inhibitor, 10-(4-methyl-piperazin-1-ylmethyl)-2H-7-oxa-1,2-diaza-benzo[de]-anthracen-3-one (GPI-15427), to enhance the effect of radiotherapy in a xenograft model of human head and neck squamous cell carcinoma (HNSCC). METHODS: Human xenograft HNSCC tumors were established in female nude mice: animals were treated with orally administered GPI-15427 at varied doses prior to tumor irradiation. In vitro and in vivo apoptosis analyses and neutral single-cell gel electrophoresis (comet) assay were performed, with the "tail moment" calculated to evaluate DNA double-strand break damage. RESULTS: Orally administered GPI-15427 given before radiation therapy significantly reduced tumor volume, and cells demonstrated significantly elevated mean tail moments (indicative of DNA damage) and enhanced apoptosis both in vitro and in vivo, compared with radiation-alone and control groups. CONCLUSIONS: Use of the PARP-1 inhibitor GPI-15427 induced significant sensitization to radiotherapy, representing a promising new treatment in the management of HNSCC.

Retinoblastoma RB94 enhances radiation treatment of head and neck squamous cell carcinoma.

PURPOSE: To assess whether adenovirus-mediated retinoblastoma 94 (Ad-RB94) transgene expression enhances efficacy of radiation therapy (XRT) of human head and neck squamous cell carcinoma (HNSCC). EXPERIMENTAL DESIGN: The HNSCC cell lines (JHU006 and JHU012) were treated in vitro and in a nude mouse xenograft model with Ad-RB94, Ad-DL312 control vector, or untreated as mock control. Cell viability and tumor growth were evaluated and combined RB94/XRT antitumor activity was analyzed by measuring DNA double-strand breaks, apoptosis-associated early DNA fragmentation, and levels of RB-regulated cell cycle progression E2F1 transcription factor. RESULTS: Ad-RB94/XRT resulted in significant HNSCC cell growth inhibition compared with XRT alone or Ad-RB94 alone in vitro and caused significant tumor regression compared with XRT alone and Ad-DL312/XRT in JHU006 and with XRT alone, Ad-DL312/XRT and Ad-RB94 alone in JHU012 in vivo. Neutral comet analysis revealed that DNA damage was significantly elevated in cells treated with Ad-RB94 alone and Ad-RB94/XRT. Tumors treated with Ad-RB94 alone showed a striking increase in early apoptosis DNA fragmentation, and DNA fragmentation was further enhanced with XRT. In addition, levels of E2F1 were up-regulated by Ad-RB94/XRT combination, whereas Ad-RB94 alone did not affect E2F1 levels and XRT alone led to down-regulation of E2F1. CONCLUSIONS: A potent antitumor effect has been observed after Ad-RB94/XRT combination treatment in HNSCC xenograft tumors. Enhanced tumor regression correlated with increased apoptosis. Ad-RB94 treatment enhances the efficacy of XRT through tumor cell sensitization by arresting the cells at the radiation-sensitive G(2)-M cell cycle and via E2F1 up-regulation.