The Promise of Human Induced Pluripotent Stem Cells in Dental Research

Induced pluripotent stem cell-based therapy for treating genetic disorders has become an interesting field of research in recent years. However, there is a paucity of information regarding the applicability of induced pluripotent stem cells in dental research. Recent advances in the use of induced pluripotent stem cells have the potential for developing disease-specific iPSC lines in vitro from patients. Indeed, this has provided a perfect cell source for disease modeling and a better understanding of genetic aberrations, pathogenicity, and drug screening. In this paper, we will summarize the recent progress of the disease-specific iPSC development for various human diseases and try to evaluate the possibility of application of iPS technology in dentistry, including its capacity for reprogramming some genetic orodental diseases. In addition to the easy availability and suitability of dental stem cells, the approach of generating patient-specific pluripotent stem cells will undoubtedly benefit patients suffering from orodental disorders

Hyperplasia of Wistar rat tongue mucosa due to exposure to cigarette side-stream smoke

Background: Hyperplasia, a condition whereby an increasing number of cells are produced due to their uncontrolled division, represents a common symptom of carcinogenesis. Cancer is a physical manifestation of cell malignancy resulting from abnormal proliferation. Globally, oral cancer currently constitutes the sixth largest lethal form of the condition. The most common etiology of oral cancer is tobacco of which cigarettes are the most popular related product. The health risks associated with cigarette smoke not only affect active smokers but also individuals who ingest it passively. Sidestream smoke comes from the lighted end of a burning tobacco product such as a cigarette, pipe or cigar and contains nicotine and many harmful cancer-causing chemicals. Inhaling sidestream smoke increases the risk of lung and other types of cancer. Purpose: The purpose of this study was to understand how sidestream cigarette smoke initiates precancerous changes, in this case hyperplasia, in the oral mucosa epithelium of Wistar rats. Methods: The subjects were divided into three groups, a 4-week treatment group (P1), an 8-week treatment group (P2), and a control group (K), each consisting of ten subjects. The subjects were exposed to a daily two-cigarette dose of smoke. The experiment used a post-test only control group design. All samples were sacrificed during the fourth and eighth weeks. Haematoxylin-eosin staining was performed on the tongues of the Wistar rats to establish the presence of hyperplasia. Data was analyzed using a one-way ANOVA test. Results: After the Wistar rats had been exposed to cigarette smoke, an increased degree of epithelial cell proliferation (hyperplasia) showed a significant difference with a p-value <0.05 during the eighth week. Conclusion: Exposure to cigarette sidestream smoke induces increased epithelial cell proliferation (hyperplasia) in Wistar rats

Medicinska gljiva Lignosus rhinocerus svojim imunomodulacijskim učinkom i reguliranjem signalnog puta posredovanog faktorom nekroze tumora uzrokuje apoptozu i zaustavlja stanični ciklus stanica karcinoma usne šupljine ORL-204

Research background. Tiger milk mushroom (Lignosus rhinocerus) is a medicinal mushroom that is geographically distributed in the region of South China, Thailand, Malaysia, Indonesia, Philippines and Papua New Guinea. Consumption of its sclerotium has been reported to treat various ailments. However, its anticancer potential towards oral cancer cell lines is yet to be determined considering the traditional method of its consumption by biting/chewing of the sclerotium. Experimental approach. Mushroom sclerotial powder of cultivar TM02® was extracted and fractionated in a chromatographic column prior to cytotoxicity testing against a panel of human oral cancer cell lines. The capability of the identified bioactive fraction in regulating several molecules associated with its tumour necrosis factor (TNF) pathway was investigated. Results and conclusions. 2,5-Diphenyl-2H-tetrazolium bromide (MTT) proliferation assay indicated that cell lines ORL-48 (derived from gingiva), ORL-188 (derived from the tongue) and ORL-204 (derived from buccal mucosa) were inhibited by cold water extract of L. rhinocerus sclerotia and its high-molecular-mass fraction (HMM) in varying degrees with ORL-204 being most affected. Hence, the treatment of ORL-204 with HMM mushroom extract was further investigated. HMM mushroom extract induced apoptosis and G0/G1 phase cell cycle arrest through caspase-3/7 cleavage. Activities of MIP2 and COX-2 were downregulated by 0.2- and 4.6-fold respectively in the HMM mushroom extract-treated ORL-204 cells. Novelty and scientific contribution. Using ORL-204, we showed that HMM mushroom extract may act via the TNF pathway at various network sites as a potential dietary compound for cancer prevention and natural adjunct therapeutic to conventional cancer treatment.Pozadina istraživanja. Medicinska gljiva Lignosus rhinocerus rasprostranjena je na području južne Kine, Tajlanda, Malezije, Indonezije, Filipina i Papua Nove Gvineje. Sklerocij gljive koristi se za liječenje različitih oboljenja. Međutim, dosad još nije ispitan antikacerogeni učinak sklerocija ove medicinske gljive, koja se tradicionalno konzumira tako da se grize odnosno žvače, na stanice karcinoma usne šupljine. Eksperimentalni pristup. Ekstrakt praha sklerocija kultivara gljive TM02® frakcioniran je pomoću kromatografske kolone, te je zatim ispitan njegov citokosični učinak na različite stanične linije humanih karcinoma usne šupljine. Ispitana je sposobnost bioaktivne frakcije da regulira molekule koje sudjeluju u sintezi faktora nekroze tumora (TNF). Rezultati i zaključci. Ispitivanjem proliferacije stanica pomoću testa redukcije 2,5-difenil-2H-tetrazolijeva bromida (MTT) utvrđeno je da ekstrakt sklerocija L. rhinocerus dobiven hladnom vodom, i to frakcija velike molekulske mase, u različitoj mjeri inhibira rast staničnih linija ORL-48 (izoliranih iz desni), ORL-188 (izoliranih ih jezika), a ponajviše onih linije ORL-204 (izoliranih iz sluznice obraza). Stoga smo dodatno istražili učinak ekstrakta gljive velike molekulske mase na staničnu liniju ORL-204. Ektrakt je potaknuo apoptozu i zaustavio stanični ciklus u fazi G0/G1 cijepanjem kaspaze 3/7. U stanicama ORL-204 tretiranim ekstraktom gljive velike molekulske mase smanjila se aktivnost enzima MIP2 za 0,2 puta, a enzima COX-2 za 4,6 puta. Novina i znanstveni doprinos. Pomoću stanične linije ORL-204 pokazali smo da ekstrakt medicinske gljive velike molekulske mase može djelovati na sintezu faktora nekroze tumora, te se upotrijebiti kao prirodni dodatak prehrani za prevenciju razvoja karcinoma ili kao dodatak konvencionalnom liječenju karcinoma

The Response of the Tongue Epithelial on Cigarette Smoke Exposure as a Risk Factor for Oral Cancer Development

Objective The aim of this study is to analyze the tongue epithelial response to cigarette smoke exposure on a number of macrophages, lymphocytes, plasma cells, and matrix metalloproteinase 9 (MMP-9) expression to determine the risk factor of oral cancer development. Materials and Methods Thirty Rattus norvegicus will be exposed to two kinds of cigarette smoke by a smoking pump for 4 and 8 weeks. The tongues were collected to analyze the number of macrophages, lymphocytes, and plasma cells with hematoxylin-eosin. The MMP-9 expression was similarly analyzed with immunohistochemical staining and then compared with the control group. Results The number of macrophages, lymphocytes, and MMP-9 expression was higher in the 8-week cigarette smoke exposure compared to the 4-week cigarette smoke exposure and the control group (p < 0.000). The number of plasma cell did not differ in the 8-week cigarette smoke exposure from that of the control group (p > 0.05). The number of plasma cells in the tongue tissue during the 4-week cigarette smoke exposure was not determined. Conclusion Cigarette smoke exposure induces the risk of oral cancer development as a result of an increase in the number of macrophages, lymphocytes, and MMP-9 expression in the tongue epithelial

Transcriptional analysis highlights three distinct immune profiles of high-risk oral epithelial dysplasia

Oral potentially malignant disorders (OPMD) are precursors of oral squamous cell carcinoma (OSCC), and the presence of oral epithelial dysplasia (OED) in OPMD confers an increased risk of malignant transformation. Emerging evidence has indicated a role for the immune system in OPMD disease progression; however, the underlying immune mechanisms remain elusive. In this study, we used immune signatures established from cancer to delineate the immune profiles of moderate and severe OED, which are considered high-risk OPMD. We demonstrated that moderate and severe OEDs exhibit high lymphocyte infiltration and upregulation of genes involved in both immune surveillance (major histocompatibility complex-I, T cells, B cells and cytolytic activity) and immune suppression (immune checkpoints, T regulatory cells, and tumor-associated macrophages). Notably, we identified three distinct subtypes of moderate and severe OED: immune cytotoxic, non-cytotoxic and non-immune reactive. Active immune surveillance is present in the immune cytotoxic subtype, whereas the non-cytotoxic subtype lacks CD8 immune cytotoxic response. The non-immune reactive subtype showed upregulation of genes involved in the stromal microenvironment and cell cycle. The lack of T cell infiltration and activation in the non-immune reactive subtype is due to the dysregulation of CTNNB1, PTEN and JAK2. This work suggests that moderate and severe OED that harbor the non-cytotoxic or non-immune reactive subtype are likely to progress to cancer. Overall, we showed that distinct immune responses are present in high-risk OPMD, and revealed targetable pathways that could lead to potential new approaches for non-surgical management of OED

Overexpression of MMP13

Matrix metalloproteinase 13 (MMP13) plays a central role in the MMP activation cascade that enables degradation of the extracellular matrix and basement membranes, and it is identified as a potential driver in oral carcinogenesis. Therefore, this study aims to determine the copy number, mRNA, and protein expression of MMP13 in oral squamous cell carcinoma (OSCC) and to associate these expressions with clinicopathological parameters. Copy number, mRNA, and protein expression analysis of MMP13 were determined using real-time quantitative PCR and immunohistochemistry methods in OSCC samples. The correlations between MMP13 expressions and clinicopathological parameters were evaluated, and the significance of MMP13 as a prognostic factor was determined. Despite discrepancies between gene amplification and mRNA and protein overexpression rates, OSCC cases showed high amplification of MMP13 and overexpression of MMP13 at both mRNA and protein levels. High level of MMP13 protein expression showed a significant correlation with lymph node metastasis (P=0.011) and tumor staging (P=0.002). Multivariate Cox regression model analysis revealed that high level of mRNA and protein expression of MMP13 were significantly associated with poor prognosis (P<0.050). Taken together, these observations indicate that the MMP13 protein overexpression could be considered as a prognostic marker of OSCC

Factors affecting commencement and cessation of smoking behaviour in Malaysian adults

<p>Abstract</p> <p>Background</p> <p>Tobacco consumption peak in developed countries has passed, however, it is on the increase in many developing countries. Apart from cigarettes, consumption of local hand-rolled cigarettes such as <it>bidi </it>and <it>rokok daun </it>are prevalent in specific communities. Although factors associated with smoking initiation and cessation has been investigated elsewhere, the only available data for Malaysia is on prevalence. This study aims to investigate factors associated with smoking initiation and cessation which is imperative in designing intervention programs.</p> <p>Methods</p> <p>Data were collected from 11,697 adults by trained recording clerks on sociodemographic characteristics, practice of other risk habit and details of smoking such as type, duration and frequency. Smoking commencement and cessation were analyzed using the Kaplan-Meier estimates and log-rank tests. Univariate and multivariate Cox proportional hazard regression models were used to calculate the hazard rate ratios.</p> <p>Results</p> <p>Males had a much higher prevalence of the habit (61.7%) as compared to females (5.8%). Cessation was found to be most common among the Chinese and those regularly consuming alcoholic beverages. Kaplan-Meier plot shows that although males are more likely to start smoking, females are found to be less likely to stop. History of betel quid chewing and alcohol consumption significantly increase the likelihood of commencement (p < 0.0001), while cessation was least likely among Indians, current quid chewers and kretek users (p < 0.01).</p> <p>Conclusions</p> <p>Gender, ethnicity, history of quid chewing and alcohol consumption have been found to be important factors in smoking commencement; while ethnicity, betel quid chewing and type of tobacco smoked influences cessation.</p