Aggressiveness Of Oral Squamous Cell Carcinoma Research Articles

The significance of Hippo pathway protein expression in oral squamous cell carcinoma.

The Hippo pathway consists of mammalian sterile 20-like kinase 1/2 (MST1/2), large tumor suppressor 1/2 (LATS1/2), and yes-associated protein (YAP)1. Herein, we present the first report on the significance of major Hippo pathway protein expression in oral squamous cell carcinoma (OSCC). The analyses included oral epithelial dysplasia (OED, n = 7), carcinoma in situ (CIS, n = 14), and oral squamous cell carcinoma (OSCC, n = 109). Cytoplasmic expression of MST1, LATS1, and LATS2 was low in OED, CIS, and OSCC. The cytoplasmic expression of MST2 was high in OED (5/7 cases), CIS (9/14 cases), and poorly differentiated OSCC (8/8 cases) but was low/lost in a proportion of differentiated OSCC (60/101 cases). The expression of YAP1 was associated with differentiation; low YAP expression was significantly more frequent in well-differentiated OSCC (35/71 cases), compared to moderately and poorly differentiated OSCC (11/38 cases). An infiltrative invasion pattern was associated with a high expression of MST2 and high expression of YAP1. The high expression of YAP1 was associated with features of epithelial-to-mesenchymal transition (EMT), such as the loss of E-cadherin and high expression of vimentin, laminin 5, and Slug. High expression of protein arginine methyltransferase (PRMT) 1 or 5, which positively regulates YAP activity, was associated with the high expression of YAP1 (p < 0.0001). Among the major Hippo pathway proteins, MST2 displayed a distinctive expression pattern in a significant proportion of differentiated OSCC, suggesting a possible differential role for MST2 depending on the course of OSCC progression. A high YAP1 expression may indicate aggressive OSCC with EMT via PRMTs at the invasive front.

Differential Protein Expression in Response to Varlitinib Treatment in Oral Cancer Cell Line: an In Vitro Therapeutic Approach.

Epidermal growth factor receptor (EGFR) is the most frequently overexpressed receptor histologically exhibited by oral squamous cell carcinoma (OSCC) patients. Aberrated EGFR signaling may lead to recurrence and metastasis, thus laying the foundation of targeted therapy. Deactivating EGFR is likely to prevent downstream signaling thus resulting in apoptosis. Tyrosine kinase inhibitors (TKIs) have come into play to revert aggressiveness of OSCC. We exploited comparative proteomic analyses based on anti-EGFR potential of varlitinib, using cellular proteomes from treated and untreated groups of oral cancer cells to identify protein players functional during oral carcinogenesis. Following separation by two-dimensional electrophoresis, differentially expressed cellular proteins (varlitinib-treated and untreated cells) were analyzed and later identified using QTOF mass spectrometer. In silico analysis for protein-protein interaction was carried out using STRING. Six differentially expressed proteins were identified as binding immunoglobulin protein (BiP), heat shock protein 7 C (HSP7C), protein disulfide isomerase 1 A (PDIA1), vimentin (VIME), keratin type I cytoskeletal 14 (K1C14), and β-Actin (ACTB). Relative expression of five proteins was found to be downregulated upon varlitinib treatment, whereas only K1C14 was upregulated in treated cells compared to control. Protein network analysis depicts the interaction between BiP, PDIA1, VIME, etc. indicating their role in oral carcinogenesis. Oral cancer cells show proteome shift based on varlitinib treatment compared to corresponding controls. Our data suggest candidature of varlitinib as a potent therapeutic agent and BiP, PDIA1, HSP7C, VIME, and β-Actin as complementary/prognostic markers of OSCC.

Integrin β1 regulates the perineural invasion and radioresistance of oral squamous carcinoma cells by modulating cancer cell stemness

Perineural invasion and radioresistance are the main determinants of treatment outcomes in oral squamous cell carcinoma (OSCC), but the exact mechanism is still unknown. We conducted an in vitro experiment to evaluate the role of integrin β1 (ITGB1) in the perineural invasion, radioresistance, and tumor aggressiveness of OSCC. Two OSCC cell lines (SCC25, SCC15) and radiation-induced radioresistant OSCC cell lines were used in this study. The expression of ITGB1 was compared between control radiosensitive and radioresistant OSCC cell lines. ITGB1 was inhibited by small hairpin RNA, and then the adhesion to neuronal cells, responsiveness to radiation, and aggressiveness of both OSCC cell lines were evaluated. Expression of ITGB1 and adhesion to neuronal cells were increased in radioresistant OSCC compared with control radiosensitive OSCC, and increased ITGB1 expression was more prominent in cancer stem cell-like cells. When the expression of ITGB1 was inhibited, the adhesion to neuronal cells, resistance to radiation, and invasion and migration of radioresistant OSCC were significantly reduced. Moreover, the expression of cancer stem cell markers and size of spheroid formations were also significantly attenuated by inhibiting ITGB1. These findings suggest that ITGB1 may be a significant contributor to perineural invasion and the maintenance of radioresistance in OSCC cells, and is associated with cancer stem cell-like cells. Furthermore, our results suggest a possible relationship between perineural invasion and radioresistance of OSCC. More detailed research is warranted to evaluate the role of ITGB1 as a novel emerging therapeutic target for radioresistant OSCC.

EXPRESSION OF CYCLIN D1 IN VARYING GRADES OF ORAL SQUAMOUS CELL CARCINOMA: AN IMMUNOHISTOCHEMICAL STUDY

Objective: Cyclin D1 promotes cell cycle progression during G1 phase, a key event in G1-S transition. It is a positive regulator of cell cycle. Overexpression may lead to disturbance in normal cell cycle control and tumor formation. The objective of the study was to evaluate the expression of cyclin D1 in varying grades of oral squamous cell carcinoma (OSCC). Methods: Nine formalin-fixed paraffin embedded tissues were immunohistochemically analyzed for the expression of cyclin D1 in varying grades of OSCC. Results: Expression of cyclin D1 was more in poorly differentiated OSCC than moderately and well-differentiated OSCC. Conclusion: Increased expression of cyclin D1 was seen in poorly differentiated OSCC and thus can be used as a biomarker for the aggressiveness of OSCC.

A Comparison of Podoplanin Expression in Oral Leukoplakia and Oral Squamous Cell Carcinoma: An Immunohistochemical Study.

Oral squamous cell carcinoma (OSCC) accounts for about 90% to 95% of all malignancies of the oral cavity.The majority of OSCCs are preceded by oral potentially malignant disorders (OPMDs). Podoplanin (PDPN) is a mucin-like small transmembrane glycoprotein. Alterations in PDPN immunoexpression have been reported in OPMDs and OSCCs. The objectives of this study were to evaluate the role of PDPN immunoexpression in oral leukoplakia (OL) and different histological grades of OSCC and to assess the role of PDPN as a potential biomarker for predicting the risk of malignant transformation. Immunohistochemical analysis for PDPN was performed in 45 histologically confirmed cases of formalin-fixed, paraffin-embedded specimens of different grades of OSCCs and 15 cases of OLs with 15 cases of the normal oral mucosa (NOM) as controls. The expression and distribution of this marker were analyzed in these lesions. The immunoexpression of PDPN showed a significant increase in the expression of the percentage of positive cells, staining intensity, location of staining in the epithelium, tumor islands, and within the cells, as well as the mean lymphatic micro vessel density between NOMs, OLs, and different grades of OSCCs. Upregulation of PDPN can be related to the malignant transformation of OLs and biological aggressiveness of OSCCs. The enhanced immunoexpression of PDPN signifies that this immunomarker can have a role in tumor cell differentiation and the neoplastic progression of OSCCs. Increased density of lymphatic vessels suggested an important role of lymphangiogenesis in tumor progression and also as a prognostic factor for lymph nodal metastasis.

RELA promotes the progression of oral squamous cell carcinoma via TFAP2A-Wnt/β-catenin signaling.

Oral squamous cell carcinoma (OSCC) has emerged as the most prevailing oral malignancy worldwide, characterized by cervical solid lymph node metastasis and strong local invasiveness. Overexpression of Transcription Factor AP-2 alpha (TFAP2A) is observed in a significant proportion of OSCC cases. In this study, we aimed to elucidate the function of TFAP2A in the progression of OSCC and the related molecular signaling pathways. The role of RELA was predicted using bioinformatics analysis. The mRNA abundances of RELA, TFAP2A, and β-catenin were assessed by Western blot and quantitative real-timePCR. The relationship between RELA, TFAP2A, and β-catenin and their correlation with clinicopathological characteristics of OSCC was evaluated. The target of RELA and TFAP2A was identified by the chromatin immunoprecipitation as well as luciferase reporter assay. The colony formation assay and MTS assay were performed to determine the proliferative level of OSCC cells. OSCC cell motility was determined by Transwell assay and wound-healing assay. The protein expressions of epithelial-mesenchymal transition-associated factors were evaluated by Western blot. The expressions of RELA and TFAP2A were elevated in OSCC, and their expressions displayed a positive correlation. The expression levels of RELA and TFAP2A were found to be associated with TNM staging and lymphatic metastasis of OSCC patients. RELA upregulation promoted OSCC progression, as manifested by increased levels of proliferation, invasion, and migration of OSCC cells. We also demonstrated that RELA was directly bound to the promoter of TFAP2A transcription, which activated multiple malignant and metastatic phenotypes. Furthermore, TFAP2A activated the Wnt/β-catenin signaling by targeting the promoter regions of β-catenin. The study found that RELA is critical for promoting the progression of OSCC via the RELA-TFAP2A-Wnt/β-catenin signaling pathway. The RELA-TFAP2A-Wnt/β-catenin signaling pathway is a potential target for reducing the aggressiveness of OSCC.

Stress induced phosphoprotein 1 overexpression controls proliferation, migration and invasion and is associated with poor survival in oral squamous cell carcinoma.

Although there have been remarkable achievements in the molecular landscape of oral squamous cell carcinoma (OSCC) in recent years, bringing advances in the understanding of its pathogenesis, development and progression, little has been applied in the prognosis and choosing the optimal treatment. In this study, we explored the influence of the stress induced phosphoprotein 1 (STIP1), which is frequently reported to be highly expressed in many cancers, in OSCCs. STIP1 expression was assessed in the TCGA database and in two independent cohorts by immunohistochemistry. Knockdown strategy was applied in OSCC cell lines to determine the impact of STIP1 on viability, proliferation, migration and invasion. The zebrafish model was applied for studying tumor formation and metastasis in vivo. The association of STIP1 and miR-218-5p was explored by bioinformatics and mimics transfection. STIP1 was highly expressed in OSCCs and significantly associated with shortened survival and higher risk of recurrence. STIP1 down-regulation decreased proliferation, migration and invasion of tumor cells, and reduced the number of metastases in the Zebrafish model. STIP1 and miR-218-5p were inversely expressed, and the transfection of miR-218-5p mimics into OSCC cells decreased STIP1 levels as well as proliferation, migration and invasion. Our findings show that STIP1 overexpression, which is inversely associated with miR-218-5p levels, contributes to OSCC aggressiveness by controlling proliferation, migration and invasion and is a determinant of poor prognosis.

Circular RNA 0000311 Aggravates the Aggressiveness of Oral Squamous Cell Carcinoma via miR-876-5p/EZH2 Axis.

The purpose of the present study was to investigate the potentials of circ_0000311 in oral squamous cell carcinoma (OSCC). Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for calculating the mRNA and miRNA level. Western blot was performed to determine protein expression. The binding sites between miR-876-5p and circ_0000311/Enhancer of zeste homolog-2 (EZH2) were predicted using bioinformatics tools and confirmed by luciferase and RNA pull-down assays. Cell proliferation was detected using CCK-8 and colony formation assay. Cell migration and invasion were detected using transwelll assay. Cellular functions were determined using CCK-8, colony, and transwell assay. The results showed that circ_0000311 was overexpressed in OSCC tissues and cells. However, circ_0000311 knockdown impeded the proliferation and epithelial-mesenchymal transition (EMT) of OSCC cells. Circ_0000311 targeted miR-876-5p, down-regulation of which promoted the aggressiveness of OSCC. Additionally, circ_0000311 sponged miR-876-5p to up-regulate a key regulator of EMT EZH2, which promoted the proliferation and aggressiveness of OSCC. Taken together, circ_0000311 aggravated the OSCC progression via regulating miR-876-5p/EZH2 axis.

A study on histological grading systems of oral squamous cell carcinoma and comparison of their efficacy in determining the nature (clinical and histopathological) and prognosis of oral squamous cell carcinoma.

Tumour-Node-Metastasis (TNM) staging has been widely used for treatment planning and prognostication of oral cancers; however, TNM staging system alone is insufficient for optimal prognostication. A combined assessment of clinical staging and cytomorphology might serve as a more specific measure for prognostication. The present study attempted to compare the efficacy of histologic grading systems (Jakobbson et al., Anneroth et al. and Bryne et al.) of malignancy in determining the nature and prognosis of oral squamous cell carcinoma (OSCC). Tumour protein (TP53) immunohistochemical marker was used to determine the aggressiveness of OSCC. Tissue sections from 24 biopsy-proven cases of OSCC were stained with anti-TP53 antibody. Hundred cells in each case were counted and tabulated. Cases were graded using three histopathological grading systems. Findings were compared and correlated with TP53 immunopositivity and clinical parameters. Positive correlation was observed between TP53 immunostaining and grading scores of each system. Highest correlation was observed with Jakobbson et al. grading system (r2 value = 0.91, P < 0.001). Significant results were observed on comparing grades of Jakobsson et al., Anneroth et al. and Bryne et al. grading system with segregated groups of TP53 immunopositive cases (P = 0.004, P = 0.003, P = 0.001, respectively). No significant results were observed on comparing grades of histopathological systems with clinical parameters. Both, clinical and histopathological grading systems, with immunohistochemistry, should be taken into account during the assessment of OSCC, for treatment planning and better prediction of tumour prognosis.

Evaluation of Invasive Tumour Front in Primary and Secondary Oral Squamous Cell Carcinoma – A Reliable Prognostic Parameter

Introduction: Oral squamous cell carcinoma (OSCC) is the most common malignant epithelial neoplasm affecting the oral cavity. Recent work indicates that morphological and molecular characteristics of tumour cells at invasive tumor fronts (ITF) underlie the biological aggressiveness of OSCC. The aim of the study was to compare the pattern of invasion (POI) (Type I to V) at tumour–host interface in 150 primary and 50 secondary OSCC cases. Materials and Methods: Both pre-dominant POI and worst POI was evaluated in all cases. Pre-dominant pattern of invasion and worst pattern of invasion (WPOI) were compared with Broder's grading system. Statistical analysis was done using a statistical software package (SPSS) and Fisher's exact test. Results: Results showed that the WPOI pattern also moves towards higher scores as the grade increases. Conclusion: We thus conclude that POI could serve as an individual prognostic marker irrespective of the histologic differentiation of the tumour.

Effects of Allocryptopine on the Proliferation and Epithelial-Mesenchymal Transition of Oral Squamous Cell Carcinoma through m6A Mediated Hedgehog Signaling Pathway.

Allocryptopine is an isoquinoline alkaloid extracted from Macleaya cordata. This study aimed to explore the effects of allocryptopine on the growth and metastasis of oral squamous cell carcinoma (OSCC) cells. The human OSCC cell line HSC-3 and SAS were selected in this study. MTT assay was performed to measure cell viability. Western blot was used to detect protein expressions. transwell assay was conducted to determine the migrated and invaded cells. M6A modification was confirmed by methylated RNA immunoprecipitation assay. Compared with the NC group, the cell viability, migration and invasion ability of OSCC cells were suppressed after allocryptopine treatment in a dose dependent manner. Allocryptopine upregulated the E-cadherin expression and downregulated N-cadherin and Vimentin expressions in the OSCC cells. In addition, the protein expressions of patched receptor 1 (PTCH1), smoothened co-receptor (SMO) and Gli family (GLI1) were downregulated after allocryptopine treatment. Furthermore, allocryptopine treatment decreased the expression of Methyltransferase like 3 (METTL3) and inhibited N6-methyladenosine (m6A) modification of PTCH1. Moreover, overexpression of PTCH1 reversed the effects of allocryptopine and induced the aggressiveness of OSCC cells. Allocryptopine suppressed the proliferation and epithelial-mesenchymal transition (EMT) of OSCC cells via m6A mediated Hedgehog signaling pathway, relieving the carcinogenic behaviors of OSCC.

The role of tumor acidification in aggressiveness, cell dissemination and treatment resistance of oral squamous cell carcinoma

AimsTo investigate the role of tumor acidification in cell behavior, migration, and treatment resistance of oral squamous cell carcinoma (OSCC). Main methodsThe SCC4 and SCC25 cell lines were exposed to acidified (pH 6.8) cell culture medium for 7 days. Alternatively, a long-term acidosis was induced for 21 days. In addition, to mimic dynamic pH fluctuation of the tumor microenvironment, cells were reconditioned to neutral pH after experimental acidosis. This study assessed cell proliferation and viability by sulforhodamine B and flow cytometry. Individual and collective cell migration was analyzed by wound healing, time lapse, and transwell assays. Modifications of cell phenotype, EMT induction and stemness potential were investigated by qRT-PCR, western blot, and immunofluorescence. Finally, resistance to chemo- and radiotherapy of OSCC when exposed to acidified environmental conditions (pH 6.8) was determined. Key findingsThe exposure to an acidic microenvironment caused an initial reduction of OSCC cells viability, followed by an adaptation process. Acidic adapted cells acquired a mesenchymal-like phenotype along with increased migration and motility indexes. Moreover, tumoral extracellular acidity was capable to induce cellular stemness and to increase chemo- and radioresistance of oral cancer cells. SignificanceIn summary, the results showed that the acidic microenvironment leads to a more aggressive and treatment resistant OSCC cell population.

Integrated analysis and identification of nine-gene signature associated to oral squamous cell carcinoma pathogenesis.

The online version contains supplementary material available at 10.1007/s13205-021-02737-4.

Sarcomatoid carcinoma of the tongue in chronic graft versus host disease: An unusual report

AbstractSarcomatoid carcinoma (SC) occurs rarely in the oral mucosa, especially in the tongue. Conversely, chronic graft versus host disease (cGVHD) is a risk factor for secondary malignant tumors, especially oral squamous cell carcinoma (OSCC). This suggests that tumor formation caused by regulation of cGVHD is important for an effective understanding of SC. Herein, we report an unusual case of SC of the tongue in a patient with cGVHD. Short tandem repeat analysis using genomic DNA extracted from the tumor and lymphocytes of the patient was performed, and the loci of the donor and recipient were detected from the tumor locus. These data suggest that the SC was an undifferentiated carcinoma originating from donor cells that underwent epithelial mesenchymal transition. The clinical, pathological, and genomic features suggest an SC characterized by an undifferentiated aggressive OSCC occurring after cGVHD.

RGS12 Represses Oral Cancer via the Phosphorylation and SUMOylation of PTEN

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer characterized by aggressive local invasion and metastasis. The pathogenesis of OSCC is mainly due to the accumulation of genetic alterations in epithelial cells, but the underlying mechanism for its development remains unclear. Here, we found that the expression level of regulator of G protein signaling 12 (RGS12) was significantly reduced in human OSCC. To understand the role and mechanism of RGS12 in OSCC, we generated a novel RGS12 global knockout (CMVCre/+; RGS12fl/fl) mouse model by crossing RGS12fl/fl mice with CMV-Cre transgenic mice and then further induced the mice to develop OSCC by using 4-nitroquinoline 1-oxide (4NQO). Deletion of RGS12 exhibited aggressive OSCC in the tongue compared with the control RGS12fl/fl mice. Knockdown of RGS12 in OSCC cells significantly increased cell proliferation and migration. Mechanistically, we found that RGS12 associated with phosphatase and tension homolog (PTEN) via the PDZ domain to upregulate the phosphorylation and SUMOylation of PTEN and then correspondingly inactivated the AKT/mTOR signaling pathway. To test the potential therapeutic effect of RGS12 on OSCC, we overexpressed RGS12 in OSCC cells and found a significant inhibition of cancer cell proliferation and migration. Moreover, subcutaneous inoculation of RGS12-overexpressed OSCC cells in NOD scid mice showed a significant reduction in tumor formation. Our findings reveal that RGS12 is an essential tumor suppressor and highlights RGS12 as a potential therapeutic target and prognostic biomarker of OSCC.

Preclinical Assessment of the Effectiveness of Magnetic Resonance Molecular Imaging of Extradomain-B Fibronectin for Detection and Characterization of Oral Cancer.

Oral squamous cell carcinoma (OSCC) has not seen a substantial improvement in patient survival despite therapeutic advances, making accurate detection and characterization of the disease a clinical priority. Here, we aim to demonstrate the effectiveness of magnetic resonance imaging (MRI) with the targeted MRI contrast agent MT218 specific to extradomain-B fibronectin (EDB-FN) in the tumor microenvironment for detection and characterization of aggressive OSCC tumors. EDB-FN expression was evaluated in human normal tongue and OSCC specimens with immunohistochemistry. Invasiveness of human CAL27, HSC3, and SCC4 OSCC cells was analyzed with spheroid formation and transwell assays. EDB-FN expression in the cells was analyzed with semiquantitative real-time PCR, western blotting, and a peptide binding study with confocal microscopy. Contrast-enhanced MRI with MT218 was performed on subcutaneous OSCC mouse models at a dose of 0.04mmol/kg, using gadoteridol (0.1mmol/kg) as a control. Strong EDB-FN expression was observed in human untreated primary and metastatic OSCC, reduced expression in treated OSCC, and little expression in normal tongue tissue. SCC4 and HSC3 cell lines demonstrated high invasive potential with high and moderate-EDB-FN expression, respectively, while CAL27 showed little invasive potential and low-EDB-FN expression. In T1-weighted MRI, MT218 produced differential contrast enhancement in the subcutaneous tumor models in correlation with EDB-FN expression in the cancer cells. Enhancement in the high-EDB-FN tumors was greater with MT218 at 0.04mmol/kg than gadoteridol at 0.1mmol/kg. The results suggest EDB-FN has strong potential as an imageable biomarker for aggressive OSCC. MRMI results demonstrate the effectiveness of MT218 and the potential for differential diagnostic imaging of oral cancer for improving the management of the disease.

Aggressive Squamous Cell Carcinoma Oral and Immediate Implant: Case Report

The objective of this work was to describe clinically, surgically and immediate oral rehabilitation of a patient with aggressive oral squamous cell carcinoma, or the most frequent in the oral cavity, in which the majority are frequent and treated with resection and subsequent rehabilitation.

Immunohistochemical Expression of BubR1 and Telomerase in Oral Squamous Cell Carcinoma

Objective: Aberrant BubR1 and Telomerase expressions are considered as important markers in tumor progression and clinical outcome. This study purposed to describe, compare, and correlate the immunohistochemical expression of BubR1 and Telomerase in oral squamous cell carcinoma (OSCC).&#x0D; Methods: Immunohistochemical staining was performed for 28 OSCC samples. The samples graded according to Bryne’s grading system. The reaction positivity, intracellular localization, and intensity were recorded. The expression distribution and mean-ranks of these markers were related to OSCC grades by Fisher’s exact and Kruskal Wallis tests. Finally, the correlation between them was achieved by Spearman’s rho test.&#x0D; Results: BubR1 was detected in 89.3% of OSCCs, equally within scores 2 and 3 (35.7%), presented with 50% faint intensity, and 64.3% cytoplasmic localization. Grade III had a significantly higher mean-rank of BubR1 scoring. Whereas Telomerase observed in 75% of OSCCs, mainly found at scores 2 and 3 (60.7%), and 42.9% was within the cytoplasm. Half of OSCCs had faint intensity. No significant differences reported in the mean-rank and stain intensity among the grades. There was no significant correlation between BubR1 and Telomerase expression.&#x0D; Conclusions: OSCCs had high cytoplasmic BubR1 and telomerase expression that cannot ensure proper function. Mean-rank of BubR1 expression related to OSCC grading and being more in high grade. It determines the loss of differentiation and aggressiveness of OSCC. While the mean-rank of Telomerase did not relate to histopathological grading and considered an early event in carcinogenesis, it can use for the diagnostic approach of oral carcinogenesis. These markers have an independent role in cancer progression.

Characterisation of a subpopulation of CD133+ cancer stem cells from Chinese patients with oral squamous cell carcinoma

Cancer stem cells (CSCs) play a critical role in cancer development and growth. The aim of this study was to identify and isolate CSCs from populations of primary oral squamous cell carcinoma (OSCC) cells, which were obtained from OSCC specimens and identified by cell morphology and immunohistochemical staining for keratin. CD133+ cells detected by flow cytometry comprised 0.41 ± 0.06% of primary OSCC cells and were isolated from primary OSCC cell populations using magnetic-activated cell sorting, revealing that 93.39% of high-purity CD133+ cells were in the G0/G1 phase of the cell cycle. Additionally, the growth rate of CD133+ cells was higher than that of CD133− cells, and in vivo tumourigenesis experiments showed that the tumourigenic ability of CD133+ cells was markedly stronger than that of CD133− cells. Moreover, CD133+ cells showed increased chemotherapeutic resistance to cisplatin and higher self-renewal ability according to sphere-formation assay, as well as higher mRNA levels of stemness-associated genes, including NANOG, SOX2, ALDH1A1, and OCT4. These results indicated that OSCC cells, which share certain characteristics of CSCs, harbour CD133+ cells potentially responsible for OSCC aggressiveness, suggesting CD133 as a potential prognostic marker and therapeutic target.

Chemopreventive activity of Tualang honey against oral squamous cell carcinoma-in vivo.

The aim of this study was to evaluate the chemopreventive activity of Malaysian jungle Tualang honey (TH) after oral carcinogenesis induced with 4-nitroquinoline 1-oxide (4 NQO). A total of 28 male Sprague-Dawley (SD) rats were distributed into 4 groups as follows: group 1 (nontreated group); group 2 (control), which received 4 NQO during 8 weeks in drinking water only; and groups 3 and 4, which received 4 NQO for 8 weeks in drinking water and treated with TH 1000 mg/kg and 2000 mg/kg by oral gavage for 10 weeks. All rats from all experiments were sacrificed after 22 weeks, and the incidence of oral neoplasms and histopathologic changes were microscopically evaluated. Moreover, immunohistochemical expression was analyzed in tongue specimens by using image analysis software. The expression of particular genes associated with oral cancer were assessed by using RT2 Profiler PCR Array (Qiagen, Germantown, MD). TH significantly reduced the incidence of oral squamous cell carcinoma (OSCC) and suppressed cancer cell proliferation via diminishing the expression of CCND1, EGFR, and COX-2. Furthermore, TH preserved cellular adhesion (epithelial polarity) through overexpression of β-catenin and e-cadherin and inhibited the OSCC aggressiveness by downregulating TWIST1 and RAC1. Our data suggest that TH exerts chemopreventive activity in an animal model in which oral cancer was induced by using 4 NQO.