Areca nut exposure increases secretion of tumor‐promoting cytokines in gingival fibroblasts that trigger DNA damage in oral keratinocytes

Illeperuma, Rasika P.,Kim, Do Kyeong,Park, Young Jin,Son, Hwa Kyung,Kim, Jue Young,Kim, Jinmi,Lee, Doo Young,Kim, Ki‐,Yeol,Jung, Da‐,Woon,Tilakaratne, Wanninayake M.,Kim, Jin Alan R. Liss, Inc 2015 International journal of cancer Vol.137 No.11

<▼1><P>Molecular crosstalk between cancer cells and fibroblasts has been an emerging hot issue in understanding carcinogenesis. As oral submucous fibrosis (OSF) is an inflammatory fibrotic disease that can potentially transform into squamous cell carcinoma, OSF has been considered to be an appropriate model for studying the role of fibroblasts during early stage carcinogenesis. In this sense, this study aims at investigating whether areca nut (AN)‐exposed fibroblasts cause DNA damage of epithelial cells. For this study, immortalized hNOF (hTERT‐hNOF) was used. We found that the levels of GRO‐α, IL‐6 and IL‐8 increased in AN‐exposed fibroblasts. Cytokine secretion was reduced by antioxidants in AN‐exposed fibroblasts. Increase in DNA double strand breaks (DSB) and 8‐oxoG FITC‐conjugate was observed in immortalized human oral keratinocytes (IHOK) after the treatment of cytokines or a conditioned medium derived from AN‐exposed fibroblasts. Cytokine expression and DNA damage were also detected in OSF tissues. The DNA damage was reduced by neutralizing cytokines or antioxidant treatment. Generation of reactive oxygen species (ROS) and DNA damage response, triggered by cytokines, were abolished when NADPH oxidase (NOX) 1 and 4 were silenced in IHOK, indicating that cytokine‐triggered DNA damage was caused by ROS generation through NOX1 and NOX4. Taken together, this study provided strong evidence that blocking ROS generation might be a rewarding approach for cancer prevention and intervention in OSF.</P></▼1><▼2><P><B>What's new?</B></P><P>Fibroblasts in the tumor microenvironment influence tumor initiation and growth and are of particular interest in oral submucous fibrosis (OSF), a progressive fibrotic disease of malignant potential. This study shows that the release of tumor‐promoting cytokines by fibroblasts exposed to areca nut, the primary cause of OSF, induce DNA damage in oral keratinocytes. The findings suggest that fibroblasts indirectly promote epithelial transformation in OSF by secreting cytokines, whereby DNA damage of epithelial cells is inflicted by reactive oxygen species generated <I>via</I> NADPH oxidases. These insights could inform the development of new therapeutic approaches for OSF.</P></▼2>

Immortalized gingival fibroblasts as a cytotoxicity test model for dental materials.

Illeperuma, Rasika P,Park, Young J,Kim, Jin M,Bae, Jung Y,Che, Zhong M,Son, Hwa K,Han, Mi R,Kim, Kwang M,Kim, Jin Chapman and Hall ; Kluwer Academic Publishers 2012 Journal of materials science, Materials in medicin Vol.23 No.3

<P>In vitro cytotoxicity test is an initial step to identify the harmful effects of new dental materials. Aim of this study was to develop a stable human cell line derived from normal gingival fibroblasts (hNOF) and to assess its feasibility in in vitro cytotoxicity testing. Immortalized human gingival fibroblasts (hTERT-hNOF) were successfully established with human telomerase reverse transcriptase gene transfection, preserving its phenotypical characteristics, replicative potential and biological properties. Utilizing standard cytotoxicity test modeling and dental materials, hTERT-hNOF were evaluated for their feasibility in cytotoxicity testing, compared with hNOF and L929 cells. Similar pattern of cytotoxic response was observed among hNOF, hTERT-hNOF and L929 cells. Cytotoxicity response of hTERT-hNOF was significantly similar to hNOF, moreover hTERT-hNOF and hNOF were found to be more sensitive towards the tested dental materials compared to L929 cells. This study suggested that hTERT-hNOF is an effective cytotoxic test model for dental materials.</P>

Cytotoxicity evaluation of zinc oxide-eugenol and non-eugenol cements using different fibroblast cell lines

Kwon, Jae-Sung,Illeperuma, Rasika P.,Kim, Jin,Kim, Kwang-Mahn,Kim, Kyoung-Nam Informa Healthcare 2014 Acta odontologica scandinavica Vol.72 No.1

<P><B><I>Objectives:</I></B> Despite being commonly used as temporary cements in dentistry, there is a lack of studies regarding the cytotoxicity of zinc oxide-eugenol (ZOE) and zinc oxide non-eugenol (ZONE) cements. In addition, cytotoxicity evaluation of the materials often involves animal-based cells. Therefore, in this study, a cytotoxicity evaluation of commercially available ZOE and ZONE cements was carried out using both animal and human-based cells. <B><I>Materials and methods.</I></B> The extraction or dilution of the extraction from four commercially available cements (two zinc oxide-eugenol and two zinc oxide non-eugenol) was tested for cytotoxicity, using three different cells and a water-soluble treatzolium salt assay. The results were confirmed using a confocal laser microscope following calcein AM and ethidium homodimer-1 staining. <B><I>Results.</I></B> The results showed that there was a significant difference in cell viability depending on which cell was used, even when the same material was tested. Generally, L929 showed relatively low cell viability with a low EC50 (effective concentration of extracts that caused 50% of cell viability compared to the control) value compared to both HGF-1 and hTERT-hNOF. Such results were also confirmed by a confocal laser microscope. <B><I>Conclusions.</I></B> Careful consideration on interpreting the results for cytotoxicity evaluation of ZOE and ZONE cements is needed when different cells are used.</P>

섬유아세포 종류에 따른 산화아연유지놀 및 비유지놀 시멘트의 세포독성시험 결과

권재성,Rasika P. Illeperuma,김진,김광만,김경남 대한치과재료학회 2012 대한치과기재학회 학술대회 Vol.2012 No.4

A Distinct Role for Interleukin‐6 as a Major Mediator of Cellular Adjustment to an Altered Culture Condition

Son, Hwa‐,Kyung,Park, Iha,Kim, Jue Young,Kim, Do Kyeong,Illeperuma, Rasika P.,Bae, Jung Yoon,Lee, Doo Young,Oh, Eun‐,Sang,Jung, Da‐,Woon,Williams, Darren R.,Kim, Jin John Wiley and Sons Inc. 2015 Journal of cellular biochemistry Vol.116 No.11

<P><B>ABSTRACT</B></P><P>Tissue microenvironment adjusts biological properties of different cells by modulating signaling pathways and cell to cell interactions. This study showed that epithelial–mesenchymal transition (EMT)/ mesenchymal–epithelial transition (MET) can be modulated by altering culture conditions. HPV E6/E7‐transfected immortalized oral keratinocytes (IHOK) cultured in different media displayed reversible EMT/MET accompanied by changes in cell phenotype, proliferation, gene expression at transcriptional, and translational level, and migratory and invasive activities. Cholera toxin, a major supplement to culture medium, was responsible for inducing the morphological and biological changes of IHOK. Cholera toxin per se induced EMT by triggering the secretion of interleukin 6 (IL‐6) from IHOK. We found IL‐6 to be a central molecule that modulates the reversibility of EMT based not only on the mRNA level but also on the level of secretion. Taken together, our results demonstrate that IL‐6, a cytokine whose transcription is activated by alterations in culture conditions, is a key molecule for regulating reversible EMT/MET. This study will contribute to understand one way of cellular adjustment for surviving in unfamiliar conditions. J. Cell. Biochem. 116: 2552–2562, 2015. © 2015 The Authors. <I>Journal of Cellular Biochemistry</I> Published by Wiley Periodicals, Inc.</P>

Effect of Areca Nut on Helicobacter pylori-Induced Gastric Diseases in Mice

( Jinwook Lee ),( Niluka D Gunawardhana ),( Sungil Jang ),( Yun Hui Choi ),( Rasika P Illeperuma ),( Aeryun Kim ),( Hanfu Su ),( Youngmin A Hong ),( Ji-hye Kim ),( Jinmoon Kim ),( Da-woon Jung ),( In- 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.10

Areca nut (AN) chewing is a habit in many countries in Central, Southern, and Southeast Asia. It is strongly associated with the occurrence of oral, pharyngeal, and esophageal cancer as well as systemic inflammation. However, the association between AN intake and the development of gastric lesions has not yet been identified. The aim of this study was to investigate the effect of AN on gastric diseases using a mouse model for Helicobacter pylori infection. We studied four groups of mice: those fed a normal diet (ND), those fed a diet containing 2.5% AN (AD), those fed ND and infected with H. pylori PMSS1 strain (ND/HP), and those fed AD and infected with H. pylori PMSS1 strain (AD/HP). Food intake and body weight were monitored weekly during the experiments. At 10 weeks, the mice were sacrificed, and the stomach weight, H. pylori colonization, and gastric inflammation were evaluated. The stomach weight had increased significantly in the ND/HP and AD/HP groups along with increases in H. pylori colonization; however, there was no significant difference between these two groups with respect to stomach weight and colonization. On histological grading, mononuclear cell infiltration was severer in the AD/HP group than in the ND/HP group. These data suggest that chronic gastric inflammation was aggravated by AN treatment in the mice with H. pyloriinduced gastric lesions. Furthermore, as previously suggested, this animal model is useful to determine the effect of potential carcinogens on gastric lesions induced by H. pylori infection.