Background
Microbial dysbiosis and microbiome-induced inflammation have emerged as important factors in oral squamous cell carcinoma (OSCC) tumorigenesis during the last two decades. However, the ...“rare biosphere” of the oral microbiome, including fungi, has been sparsely investigated. This study aimed to characterize the salivary mycobiome in a prospective Sudanese cohort of OSCC patients and to explore patterns of diversities associated with overall survival (OS).
Materials and Methods
Unstimulated saliva samples (
n
= 72) were collected from patients diagnosed with OSCC (
n
= 59) and from non-OSCC control volunteers (
n
= 13). DNA was extracted using a combined enzymatic–mechanical extraction protocol. The salivary mycobiome was assessed using a next-generation sequencing (NGS)-based methodology by amplifying the ITS2 region. The impact of the abundance of different fungal genera on the survival of OSCC patients was analyzed using Kaplan–Meier and Cox regression survival analyses (SPPS).
Results
Sixteen genera were identified exclusively in the saliva of OSCC patients.
Candida
,
Malassezia
,
Saccharomyces
,
Aspergillus
, and
Cyberlindnera
were the most relatively abundant fungal genera in both groups and showed higher abundance in OSCC patients. Kaplan–Meier survival analysis showed higher salivary carriage of the
Candida
genus significantly associated with poor OS of OSCC patients (Breslow test:
p
= 0.043). In contrast, the higher salivary carriage of
Malassezia
showed a significant association with favorable OS in OSCC patients (Breslow test:
p
= 0.039). The Cox proportional hazards multiple regression model was applied to adjust the salivary carriage of both
Candida
and
Malassezia
according to age (
p
= 0.029) and identified the genus
Malassezia
as an independent predictor of OS (hazard ratio = 0.383, 95% CI = 0.16–0.93,
p
= 0.03).
Conclusion
The fungal compositional patterns in saliva from OSCC patients were different from those of individuals without OSCC. The fungal genus
Malassezia
was identified as a putative prognostic biomarker and therapeutic target for OSCC.
Two cases of peripheral odontogenic keratocyst (POKC) of the gingiva presenting as asymptomatic nodules are described. The exceptional finding of cystic radiolucency in POKCs was observed on dental ...radiography in one case, which had a diameter of 10 mm. Conservative surgical excision was performed on both cases, and histopathological examination showed features consistent with keratocysts. POKC may recur and should thus be followed up like intraosseous keracysts. No recurrences were observed after 10-years in our two cases. POKC is managed by conservative treatment. Recurrences should be excised more radically. Adjunct treatment with modified Carnoy's solution or topical 5Fluorouracil should be considered. POKC should be included in the differential diagnosis of asymptomatic gingival nodules.
•Peripheral odontogenic keratocyst is a very rare entity, two cases are presented.•The larger cyst showed cystic radiolucency on imaging.•POKC is managed by conservative excision.•Recurrences should be managed by excision including surrounding mucosa.•POKC should be included in the differential diagnosis of asymptomatic oral nodules.
A rat model of radiation injury in the mandibular area Sønstevold, Tonje; Johannessen, Anne Christine; Stuhr, Linda
Radiation oncology (London, England),
2015-Jun-09, 2015-06-09, 20150609, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Radiation technology focuses on delivering the radiation as precisely as possible to the tumor, nonetheless both acute and long-term damage to surrounding normal tissue may develop. Injuries to the ...surrounding normal tissue after radiotherapy of head and neck cancer are difficult to manage. An animal model is needed to elucidate good treatment modalities. The aim of this study was to establish a rat model where a certain radiation dose gives reproducible tissue reactions in the mandibular area corresponding to injuries obtained in humans.
The left mandible of male Sprague Dawley rats was irradiated by external radiotherapy (single fraction 15 Gy, total dose 75 Gy) every second week five times. Endpoint was six weeks after last radiation treatment, and the test group was compared to non-irradiated controls. Morphological alterations of the soft tissues, bone and tooth formation, as well as alterations of salivation, vascularity and collagen content were assessed. An unpaired, non-parametric Mann-Whitney test was used to compare the statistical differences between the groups.
Analysis of the soft tissues and mandible within the radiation field revealed severe unilateral alopecia and dermatitis of the skin, extensive inflammation of the submandibular gland with loss of serous secretory cells, hyperkeratinization and dense connective fiber bundles of the gingival tissue, and disturbed tooth development with necrosis of the pulp. Production of saliva and the vascularity of the soft tissues were significantly reduced. Furthermore, the collagen fibril diameter was larger and the collagen network denser compared to non-irradiated control rats.
We have established an animal model of radiation injury demonstrating physiological and histological changes corresponding to human radiation injuries, which can be used for future therapeutic evaluations.
Knowledge on the role of miR changes in tumor stroma for cancer progression is limited. This study aimed to investigate the role of miR dysregulation in cancer-associated fibroblasts (CAFs) in oral ...squamous cell carcinoma (OSCC).
CAF and normal oral fibroblasts (NOFs) were isolated from biopsies of OSCC patients and healthy individuals after informed consent and grown in 3D collagen gels. Total RNA was extracted. Global miR expression was profiled using Illumina version 2 panels. The functional impact of altered miR-204 expression in fibroblasts on their phenotype and molecular profile was investigated using mimics and inhibitors of miR-204. Further, the impact of miR-204 expression in fibroblasts on invasion of adjacent OSCC cells was assessed in 3D-organotypic co-cultures.
Unsupervised hierarchical clustering for global miR expression resulted in separate clusters for CAF and NOF. SAM analysis identified differential expression of twelve miRs between CAF and NOF. Modulation of miR-204 expression did not affect fibroblast cell proliferation, but resulted in changes in the motility phenotype, expression of various motility-related molecules, and invasion of the adjacent OSCC cells. 3' UTR miR target reporter assay showed ITGA11 to be a direct target of miR-204.
This study identifies differentially expressed miRs in stromal fibroblasts of OSCC lesions compared with normal oral mucosa and it reveals that one of the significantly downregulated miRs in CAF, miR-204, has a tumor-suppressive function through inhibition of fibroblast migration by modulating the expression of several different molecules in addition to directly targeting ITGA11.
Recent studies have shown aberrant expression of micro-RNAs in cancer-associated fibroblasts (CAFs). This study aimed to investigate miR-138 dysregulation in CAFs in oral squamous cell carcinoma ...(OSCC) and its effects on their phenotype and invasion of adjacent OSCC cells.
Expression of miR-138 was first investigated in OSCC lesions (
= 53) and OSCC-derived CAFs (
= 15). MiR-138 mimics and inhibitors were used to functionally investigate the role of miR-138 on CAF phenotype and the resulting change in their ability to support OSCC invasion.
Expression of miR-138 showed marked heterogeneity in both OSCC tissues and cultured fibroblasts. Ectopic miR-138 expression reduced fibroblasts' motility and collagen contraction ability and suppressed invasion of suprajacent OSCC cells, while its inhibition resulted in the opposite outcome. Transcript and protein examination after modulation of miR-138 expression showed changes in CAF phenotype-specific molecules, focal adhesion kinase axis, and TGFβ1 signaling pathway.
Despite its heterogeneous expression, miR-138 in OSCC-derived CAFs exhibits a tumor-suppressive function.
Micro-RNAs (miRs) are emerging as important players in carcinogenesis. Their stromal expression has been less investigated in part due to lack of methods to accurately differentiate between tumor ...compartments. This study aimed to establish a robust method for dual visualization of miR and protein (pan-cytokeratin) by combining chromogen-based in situ hybridization (ISH) and immunohistochemistry (IHC), and to apply it to investigate stromal expression of miR204 as a putative prognostic biomarker in oral squamous cell carcinoma (OSCC). Four different combinations of methods were tested and ImageJ and Aperio ImageScope were used to quantify miR expression. All four dual ISH-IHC methods tested were comparable to single ISH in terms of positive pixel area percentage or integrated optical density of miRs staining. Based on technical simplicity, one of the methods was chosen for further investigation of miR204 on a cohort of human papilloma virus (HPV)-negative primary OSCC (
= 169). MiR204 stromal expression at tumor front predicted recurrence-free survival (
= 0.032) and overall survival (
= 0.036). Multivariate Cox regression further confirmed it as an independent prognostic biomarker in OSCC. This study provides a methodological platform for integrative biomarker studies based on simultaneous detection and quantification of miRs and/or protein and reveals stromal miR204 as a prognostic biomarker in OSCC.
Abstract The epithelial rests of Malassez (ERMs) might represent a valuable source of oral epithelial cells with stem cell properties. The purpose of this study was to isolate and characterize cells ...derived from human ERM, and compare them with cells derived from matched normal oral mucosa (NOM). Matched tissue specimens of the periodontal ligament of extracted tooth and NOM were collected. Cells were isolated in culture, then characterized by immunohistochemistry and flow cytometry for expression of pancytokeratin, ESA, PDGFRB, CD31 and CD44. 3D organotypic cultures were constructed by growing epithelial cells on top of fibroblast-populated collagen gels. Both ERM and NOM-isolated cells expressed the markers of epithelial lineage (ESA and pancytokeratin), and to some extent PDGFR, an indicator of a more mesenchymal phenotype, but not the endothelial cell marker CD31. Cells with epithelial morphology were isolated from periodontium of cervical, middle and apical parts of the root, but contained a significantly lower percentage of ESA and pancytokeratin-positive cells than when isolating cells from NOM (p<0.001). ERM cells expressed a significantly higher percentage of the stem cell-related molecule CD44 (cervical 92.93+-0.25%, middle 93.8+-0.26%, apical 94.36+-0.41%) than cells isolated from NOM (27.8+-1.47%, p<0.001). When grown in 3D organotypic cultures and in collagen gels, ERM cells formed a less differentiated epithelium than NOM cells, but expressing pancytokeratin and vimentin. In conclusion, epithelial cells could be isolated from human periodontium and grown in culture; their in vitro characterization indicates that they have a less differentiated phenotype compared with cells derived from normal oral epithelium.
Background: Oral squamous cell carcinoma (OSCC) is increasing at an alarming rate particularly in low-income countries. This urges for research into noninvasive, user-friendly diagnostic tools that ...can be used in limited-resource settings. This study aims to test and validate the feasibility of e-nose technology for detecting OSCC in the limited-resource settings of the Sudanese population. Methods: Two e-nose devices (Aeonose™, eNose Company, Zutphen, The Netherlands) were used to collect breath samples from OSCC (n = 49) and control (n = 35) patients. Patients were divided into a training group for building an artificial neural network (ANN) model and a blinded control group for model validation. The Statistical Package for the Social Sciences (SPSS) software was used for the analysis of baseline characteristics and regression. Aethena proprietary software was used for data analysis using artificial neural networks based on patterns of volatile organic compounds. Results: A diagnostic accuracy of 81% was observed, with 88% sensitivity and 71% specificity. Conclusions: This study demonstrates that e-nose is an efficient tool for OSCC detection in limited-resource settings, where it offers a valuable cost-effective strategy to tackle the burden posed by OSCC.
Objective To describe and analyze recurrent pattern of KOTs according to time. Study Design This retrospective chart study evaluated histologically confirmed nonsyndromic keratocystic odontogenic ...tumors (KOT) treated at our institutions between 1975 and 2012. Results Mean age at time of diagnosis was 48 years, and male/female ratio was 1.8:1. The typical nonsyndromic KOT lesion was most often found in the posterior mandible, had radiographically smooth borders, and was associated with symptoms and clinical findings, perforated bone, with a thin capsule. Anterior jaw KOT were found more frequently in patients 50 years or older, and maxillary KOTs were more frequently infected. Treatment was enucleation (n = 70) or marsupialization with subsequent enucleation (n = 22). Observation time ranged from 0.5 months to 25 years (mean 53 months). Crude recurrence rate was 29%. Risk of recurrence increased until 7 years after treatment and then remained stable. Patients with impaired general health had a significantly increased risk of recurrence. Tumors in the posterior mandible that had bone perforation and a thin capsule and contained keratin showed increased recurrence rates. Although recurrence rates were similar for both treatment groups, the groups differed in size and tumor site; thus, the results of this study need to be confirmed in a prospective study. Conclusions Time-dependent recurrence pattern of KOTs is described and analyzed. The following follow-up protocol is suggested for patients with impaired health or large lesions: clinical and radiographic examinations at 2, 4, and 7 years, followed by intervals of 3 to 4 years; for other patients: clinical and radiographic examination at 4, 6, and 8 years, followed by intervals of 3 to 4 years.
Khat (
.) is habitually used as a natural stimulant by millions of people, but is associated with adverse effects on gastrointestinal, cardiovascular and central neural systems. At the cellular level ...khat toxicity involves p53 induction and cell cycle arrest, decreased mitochondrial function and activation of receptor- and mitochondria-mediated cell death pathways. In this study we have examined an extract of khat for induction of p53 post-translational modifications (PTMs) and the functional role of p53 in khat-mediated cell death. Khat was shown to induce phosphorylation and acetylation of p53 in both the khat-sensitive MOLM-13 and the khat-resistant MV-4-11 cell line, but accumulation of the full-length p53 isoform was only observed in the khat sensitive cell line. Small molecule inhibitors of p38 MAP kinase sensitized MV-4-11 cells for khat-treatment without concomitant stabilization of p53. Experiments using a p53 knock-down cell line and murine p53 knock-out bone marrow cells indicated that p53 was redundant in khat-mediated cell death in vitro. We suggest that analysis of isoform patterns and p53 PTMs are useful for elucidation of biological effects of complex plant extracts, and that p53 protein analysis is particularly useful in the search for new chemical probes and experimental cancer therapeutics.
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