The upregulation of VGF enhances the progression of oral squamous carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a prevalent neoplasm worldwide, necessitating a deeper understanding of its pathogenesis. VGF nerve growth factor inducible (VGF), a neuropeptide, plays critical roles in nerve and endocrine cell regulation. METHODS: In this study, the TCGA datasets were initially screened, identifying the upregulation of VGF in various malignancies. We focused on OSCC cell lines, identifying the suppressor mRNA miR-432-5p as a negative regulator of VGF. Additionally, we examined the prognostic value of VGF expression in OSCC tumors and its impact on cellular functions. RESULTS: VGF expression was found to be an independent prognostic predictor in OSCC tumors. Cells expressing VGF exhibited increased oncogenicity, influencing the proliferation and migration of oral mucosal fibroblast. Transcriptome analysis revealed associations between VGF and various pathological processes, including malignancies, exosome release, fibrosis, cell cycle disruption, and tumor immune suppression. Moreover, IL23R expression, a favorable OSCC prognostic factor, was inversely correlated with VGF expression. Exogenous IL23R expression was found to suppress VGF-associated mobility phenotypes. CONCLUSIONS: This study highlights the multifaceted role of VGF in OSCC pathogenesis and introduces the miR-432-5p-VGF-IL23R regulatory axis as a critical mediator. The combined expression of VGF and IL23R emerges as a potent predictor of survival in oral carcinoma cases, suggesting potential implications for future therapeutic strategies.

Is OLP potentially malignant? A clue from ZNF582 methylation.

OBJECTIVE: Whether oral lichen planus (OLP) was potentially malignant remains controversial. Here, we examined associations of ZNF582 methylation (ZNF582m ) with OLP lesions, dysplastic features and squamous cell carcinoma (OSCC). MATERIALS AND METHODS: This is a case-control study. ZNF582m was evaluated in both lesion and adjacent normal sites of 42 dysplasia, 90 OSCC and 43 OLP patients, whereas ZNF582m was evaluated only in one mucosal site of 45 normal controls. High-risk habits affecting ZNF582m such as betel nut chewing and cigarette smoking were also compared in those groups. RESULTS: OLP lesions showed significantly lower ZNF582m than those of dysplasia and OSCC. At adjacent normal mucosa, ZNF582m increased from patients of OLP, dysplasia, to OSCC. In addition, ZNF582m at adjacent normal sites in OLP patients was comparable to normal mucosa in control group. Dysplasia/OSCC patients with high-risk habits exhibited significantly higher ZNF582m than those without high-risk habits. However, ZNF582m in OLP patients was not affected by those high-risk habits. CONCLUSIONS: OLP is unlikely to be potentially malignant based on ZNF582m levels. ZNF582m may also be a potential biomarker for distinguishing OLP from true dysplastic features and OSCC, and for monitoring the malignant transformation of OLP, potentially malignant disorders with dysplastic features and OSCC.

Identification of Somatic Mutations in Plasma Cell-Free DNA from Patients with Metastatic Oral Squamous Cell Carcinoma.

The accurate diagnosis and treatment of oral squamous cell carcinoma (OSCC) requires an understanding of its genomic alterations. Liquid biopsies, especially cell-free DNA (cfDNA) analysis, are a minimally invasive technique used for genomic profiling. We conducted comprehensive whole-exome sequencing (WES) of 50 paired OSCC cell-free plasma with whole blood samples using multiple mutation calling pipelines and filtering criteria. Integrative Genomics Viewer (IGV) was used to validate somatic mutations. Mutation burden and mutant genes were correlated to clinico-pathological parameters. The plasma mutation burden of cfDNA was significantly associated with clinical staging and distant metastasis status. The genes TTN, PLEC, SYNE1, and USH2A were most frequently mutated in OSCC, and known driver genes, including KMT2D, LRP1B, TRRAP, and FLNA, were also significantly and frequently mutated. Additionally, the novel mutated genes CCDC168, HMCN2, STARD9, and CRAMP1 were significantly and frequently present in patients with OSCC. The mutated genes most frequently found in patients with metastatic OSCC were RORC, SLC49A3, and NUMBL. Further analysis revealed that branched-chain amino acid (BCAA) catabolism, extracellular matrix-receptor interaction, and the hypoxia-related pathway were associated with OSCC prognosis. Choline metabolism in cancer, O-glycan biosynthesis, and protein processing in the endoplasmic reticulum pathway were associated with distant metastatic status. About 20% of tumors carried at least one aberrant event in BCAA catabolism signaling that could possibly be targeted by an approved therapeutic agent. We identified molecular-level OSCC that were correlated with etiology and prognosis while defining the landscape of major altered events of the OSCC plasma genome. These findings will be useful in the design of clinical trials for targeted therapies and the stratification of patients with OSCC according to therapeutic efficacy.

The Concordant Disruption of B7/CD28 Immune Regulators Predicts the Prognosis of Oral Carcinomas.

Immune modulation is a critical factor in determining the survival of patients with malignancies, including those with oral squamous cell carcinoma (OSCC) and head and neck SCC (HNSCC). Immune escape or stimulation may be driven by the B7/CD28 family and other checkpoint molecules, forming ligand-receptor complexes with immune cells in the tumor microenvironment. Since the members of B7/CD28 can functionally compensate for or counteract each other, the concomitant disruption of multiple members of B7/CD28 in OSCC or HNSCC pathogenesis remains elusive. Transcriptome analysis was performed on 54 OSCC tumors and 28 paired normal oral tissue samples. Upregulation of CD80, CD86, PD-L1, PD-L2, CD276, VTCN1, and CTLA4 and downregulation of L-ICOS in OSCC relative to the control were noted. Concordance in the expression of CD80, CD86, PD-L1, PD-L2, and L-ICOS with CD28 members was observed across tumors. Lower ICOS expression indicated a worse prognosis in late-stage tumors. Moreover, tumors harboring higher PD-L1/ICOS, PD-L2/ICOS, or CD276/ICOS expression ratios had a worse prognosis. The survival of node-positive patients was further worsened in tumors exhibiting higher ratios between PD-L1, PD-L2, or CD276 and ICOS. Alterations in T cell, macrophage, myeloid dendritic cell, and mast cell populations in tumors relative to controls were found. Decreased memory B cells, CD8+ T cells, and Tregs, together with increased resting NK cells and M0 macrophages, occurred in tumors with a worse prognosis. This study confirmed frequent upregulation and eminent co-disruption of B7/CD28 members in OSCC tumors. The ratio between PD-L2 and ICOS is a promising survival predictor in node-positive HNSCC patients.

Pyruvate Kinase Differentially Alters Metabolic Signatures during Head and Neck Carcinogenesis.

During glycolysis, the muscle isoform of pyruvate kinase PKM2 produces ATP in exchange for dephosphorylation of phosphoenolpyruvate (PEP) into pyruvate. PKM2 has been considered as a tumor-promoting factor in most cancers, whereas the regulatory role of PKM2 during head and neck carcinogenesis remained to be delineated. PKM2 mRNA and protein expression was examined in head and neck tumorous specimens. The role of PKM2 in controlling cellular malignancy was determined in shRNA-mediated PKM2-deficient head and neck squamous cell carcinoma (HNSC) cells. In agreement with the results in other cancers, PKM2 expression is enriched in both mouse and human HNSC tissues. Nevertheless, PKM2 mRNA expression reversely correlated with tumor stage, and greater recurrence-free survival rates are evident in the PKM2high HNSC population, arguing that PKM2 may be tumor-suppressive. Multifaceted analyses showed a greater in vivo xenografic tumor growth and an enhanced cisplatin resistance in response to PKM2 loss, whereas PKM2 silencing led to reduced cell motility. At the molecular level, metabolic shifts towards mitochondrial metabolism and activation of oncogenic Protein kinase B (PKB/Akt) and extracellular signal-regulated kinase (ERK) signals were detected in PKM2-silencing HNSC cells. In sum, our findings demonstrated that PKM2 differentially modulated head and neck tumorigenicity via metabolic reprogramming.

Protective Effect of Electroacupuncture on Chemotherapy-Induced Salivary Gland Hypofunction in a Mouse Model.

Radiotherapy and chemotherapy can impair salivary gland (SG) function, which causes xerostomia and exacerbate other side effects of chemotherapy and oral infection, reducing patients' quality of life. This animal study aimed to assess the efficacy of electroacupuncture (EA) as a means of preventing xerostomia induced by 5-fluorouracil (5-FU). A xerostomia mouse model was induced via four tail vein injections of 5-FU (80 mg/kg/dose). EA was performed at LI4 and LI11 for 7 days. The pilocarpine-stimulated salivary flow rate (SFR) and salivary glands weight (SGW) were recorded. Salivary immunoglobulin A (SIgA) and lysozyme were determined via enzyme-linked immunosorbent assay (ELISA). SG was collected for hematoxylin and eosin staining to measure acini number and acinar cell size. Tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and aquaporin 5 (AQP5) mRNA expressions in SG were quantified via RT-qPCR. 5-FU caused significant decreases in SFR, SGW, SIgA, lysozyme, AQP5 expression, and acini number, while TNF-α and IL-1ß expressions and acinar cell size were significantly increased. EA treatment can prevent 5-FU damage to the salivary gland, while pilocarpine treatment can only elevate SFR and AQP5 expression. These findings provide significant evidence to support the use of EA as an alternative treatment for chemotherapy-induced salivary gland hypofunction and xerostomia.

Risk factors for reconstruction plate exposure after surgery in oral cancer patients. A retrospective cohort study.

OBJECTIVES: The aim of this study was to elaborate risk factors for reconstruction plate exposure after wide excision in oral cancer patients, and to find out the most effective treatment. MATERIALS AND METHODS: We include patients who underwent ablative surgery for oral cancer and reconstruction plate fixation from the year 2010 to 2016, separate them into two groups according to whether the hardware was exposed, compare risk factors including age, tumor site, staging, comorbidities, and previous treatment between the two groups. The treatment course and outcome were also recorded. RESULTS: In total, 75 patients received reconstruction plate fixation after ablative surgery. Bone plate exposure was found in 26 cases (34.6%). The size of the bone defect and the thickness of soft tissue covering the plate were significant risk factors for plate exposure. In 21 patients (72.4%), the bone plate was removed. Conservative treatment was not effective. Removal of bone plate and debridement in one single surgery had a success rate of 81%. CONCLUSION: In this study, skin thickness less than 1.5 mm over the reconstruction plate and bone defect size larger than 8.4 cm were the two significant risk factors for bone plate exposure. Although a standardized treatment algorithm is lacking, surgical debridement with removal of the bone plate result in complete soft tissue healing in most patients and should be the treatment of choice. CLINICAL RELEVANCE: Patients with larger bone defect and thinner covering soft tissue bear more risk for exposure. The most effective treatment is to remove the hardware.

The upregulation of oncogenic miRNAs in swabbed samples obtained from oral premalignant and malignant lesions.

OBJECTIVES: Oncogenic miRNAs upregulated in OSCC play a range of versatile roles in oral carcinogenesis. Oral potentially malignant disorders (OPMDs) are the antecedent lesions to oral squamous carcinoma (OSCC) and they require a definitive diagnosis and early intervention. This study hypothesizes the presence of aberrant oncogenic miRNA expression in swabbed oral lesions. MATERIALS AND METHODS: The expression of miR-21, miR-31, miR-134, miR-146a, and miR-211 in swabbed samples from 36 dysplastic or hyperplastic OPMDs and 10 OSCCs, relative to respective normal mucosa within the same patient, is analyzed with qRT-PCR to develop a diagnosis. RESULTS: Upregulation of all tested miRNAs in OPMD and OSCC samples comparing to controls is found to have occurred. Receiver operating characteristics curve analysis shows that miR-31 gives the best diagnostic accuracy of 0.91 when differentiating OPMD/OSCC from controls. An analysis of miR-134 and miR-211 expression allows the discrimination of the dysplastic state associated with OPMD, while the use of expression of the combined miRNAs further improves the analytical performances when identifying the dysplastic state. The concordant upregulation of miR-21, miR-31, and miR-146a is found to occur during an early stage of OSCC carcinogenesis. CONCLUSION: This study demonstrates the upregulation of multiple oncogenic miRNAs in swabbed OPMD and OSCC samples. miRNA expression in swabbed collectives enables the differentiation between normal mucosa and OPMD/OSCC, independent of their histopathological severity. CLINICAL RELEVANCE: This conventional and convenient sampling tool, when coupled with an assessment of miR-31 expression, would seem to be an adjuvant approach to the diagnosis of OPMD and OSCC.

Comparison of surgical outcomes between primary plate and fibular flap transfer for reconstruction of segmental mandibular defects.

PURPOSE: Although two ways of reconstruction have been reviewed for a long period, comparison of large sample size with nearly randomized patient selection is rare. Here, we compare the surgical outcomes of these two methods from two large medical institutes. METHODS: Totally 176 patients were included from two medical centers with different protocols, 62 patients from MacKay Hospital repair defects with fibula flaps using reconstruction plates. Also 114 patients from Kaohsiung ChangGung Hospital treat with reconstruction plates combine anterior lateral thigh flaps, in which 12 cases had secondary fibula flap after plate exposure. Electronic medical records were reviewed retrospectively. Short (3-12 months) and long-term (>12 months) outcomes were evaluated. RESULTS: Short-term evaluation revealed that the secondary fibula had a higher rate of vascular complications (33 vs. 6%, p = .02). Primary fibula had a higher risk of post reconstructive surgical debridement (60 vs. 40%, p = .018). Long-term follow-up revealed radiation therapy significantly worsened bone healing (p = .03). Primary fibula had a lower rate of screw loosening (14.0 vs. 40.3%, p = .002). Radiation therapy did not increase the plate exposure rate among the groups (33 vs. 27%, p = .389). Disease free survival showed no significant difference between two groups (53.1 ± 3.5 vs. 47.8 ± 2.8 months, p = .317). CONCLUSION: Primary fibula reconstruction should be considered whenever possible to reduce the risk of late complications and simplifies the management after a potential plate exposure. Notably, radiation therapy apparently has no significant effect on plate exposure rate both in ALT or fibula groups.

LncRNA MIR31HG Drives Oncogenicity by Inhibiting the Limb-Bud and Heart Development Gene (LBH) during Oral Carcinoma.

The miR-31 host gene (MIR31HG) encodes a long non-coding RNA (LncRNA) that harbors miR-31 in its intron 2; miR-31 promotes malignant neoplastic progression. Overexpression of MIR31HG and of miR-31 occurs during oral squamous cell carcinoma (OSCC). However, the downstream effectors modulated by MIR31HG during OSCC pathogenesis remain unclear. The present study identifies up-regulation of MIR31HG expression during the potentially premalignant disorder stage of oral carcinogenesis. The potential of MIR31HG to enhance oncogenicity and to activate Wnt and FAK was identified when there was exogenous MIR31HG expression in OSCC cells. Furthermore, OSCC cell subclones with MIR31HG deleted were established using a Crispr/Cas9 strategy. RNA sequencing data obtained from cells expressing MIR31HG, cells with MIR31HG deleted and cells with miR-31 deleted identified 17 candidate genes that seem to be modulated by MIR31HG in OSCC cells. A TCGA database algorithm pinpointed MMP1, BMP2 and Limb-Bud and Heart development (LBH) as effector genes controlled by MIR31HG during OSCC. Exogenous LBH expression decreases tumor cell invasiveness, while knockdown of LBH reverses the oncogenic suppression present in MIR31HG deletion subclones. The study provides novel insights demonstrating the contribution of the MIR31HG-LBH cascade to oral carcinogenesis.

Overexpression of Platelet-Derived Growth Factor and Its Receptor Are Correlated with Oral Tumorigenesis and Poor Prognosis in Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is a cancerous disease with poor prognosis. According to the statistics, the 5-year survival rate has not improved significantly over the past 20 years. The platelet-derived growth factor (PDGF) and its signaling pathway is a key regulator of angiogenesis and tumorigenesis. High level of PDGF and its receptor (PDGFR) have been reported in several types of malignancies. In this study, we investigated the relationship of the molecular expression levels of PDGF and PDGFR with clinicopathological parameters in OSCC. To this end, we measured the mRNA and protein levels of PDGF and PDGFR by real-time quantitative PCR (qRT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA), respectively. We found positive correlations of the mRNA levels of PDGFA, PDGFB, and PDGFRB with lymph node metastasis and poor overall survival (OS). High expression of PDGF, PDGFRA, and PDGFRB were remarkably associated with lymph node metastasis and poor OS, as determined by immunohistochemistry. Preoperative serum levels of PDGF-AA and PDGF-BB had a positive correlation with preoperative platelet count. Elevated serum levels of PDGF-AA. PDGF-BB, and platelet count correlated with lymph node metastasis and an unfavorable outcome. In multivariate Cox regression analysis, PDGFA mRNA, PDGFB mRNA, PDGFRB mRNA, PDGF immunoexpression, PDGFRB immunoexpression, serum PDGF-AA, serum PDGF-BB, and platelet count emerged as significant independent prognostic factors for OS. In vitro, we found that elevated PDGF promotes colony formation, migration, and invasiveness of SAS and OECM-1 cancer cell lines. Our results suggest that the expression level of serum PDGF has the potential to become a useful diagnostic marker for the prognosis of OSCC. In addition, PDGFR should be considered as a potential therapeutic target for OSCC. Furthermore, research should be undertaken to elucidate the role of PDGF and PDGFR regarding the behavior of tumor cells in OSCC.

Establishing of mouse oral carcinoma cell lines derived from transgenic mice and their use as syngeneic tumorigenesis models.

BACKGROUND: The survival of OSCC patient needs to be further improved. miR-211 is oncogenic in OSCC and its upregulation is associated with tumor progression and poor patient survival. K14-EGFP-miR-211 transgenic mice also exhibit augmented potential for OSCC induction. METHODS: Four murine OSCC cell lines, designated MOC-L1 to MOC-L4, are established from tongue tumors induced by 4-nitroquinoline 1-oxide using the K14-EGFP-miR-211 transgenic mouse model. The genetic disruption, in vitro oncogenicity, and the eligibilities of tumorigenesis and metastasis of the cell lines are analyzed. RESULTS: All cell lines show green fluorescence and express a range of epithelial markers. The MOC-L1, MOC-L2 and MOC-L3 cells carry missense mutations in the DNA binding domain of the p53 gene. MOC-L1 exhibits a high level of epithelial-mesenchymal transition and has the aggressive characteristics associated with this. MOC-L1 and MOC-L2 are clonogenic in vitro as well as being tumorigenic when implanted into the dermis or tongue of syngeneic recipients. Nonetheless, only MOC-L1 exhibits immense potential for local regional and distal metastasis. Since the expression of miR-196b in MOC-L1 xenografts is drastically decreased on cisplatin treatment, it would seem that targeting of miR-196b might facilitate tumor abrogation. CONCLUSIONS: As cell lines established in this study originated from the C57BL/6 mouse, the strain most suitable for transgenic engineering, exploring the interplay of these OSCC cells with other genetically modified cells in immune-competent mice would provide important insights into OSCC pathogenesis.

Enrichment of Human CCR6+ Regulatory T Cells with Superior Suppressive Activity in Oral Cancer.

Human oral squamous cell carcinoma (OSCC) constitutes an inflammatory microenvironment enriched with chemokines such as CCL20, which promote cancer cell invasion and tumor progression. We found that in OSCC there is a correlation between the expression of CCL20 and FOXP3 mRNA. Therefore, we hypothesized that OSCC may favor the recruitment and retention of regulatory T (Treg) cells that express the CCL20 receptor, CCR6. Interestingly, most (∼60%) peripheral blood Treg cells express CCR6, and CCR6+ Treg cells exhibit an activated effector/memory phenotype. In contrast, a significant portion (>30%) of CCR6- Treg cells were found to be CD45RA+ naive Treg cells. Compared to CCR6- naive or memory Treg cells, CCR6+ Treg cells exhibit stronger suppressive activity and display higher FOXP3 expression along with lower methylation at the Treg-specific demethylated region of the FOXP3 gene. This predominance of CCR6+ Treg cells was also found in the draining lymph nodes and tumor-infiltrating lymphocytes of OSCC patients with early or late clinical staging. Moreover, CCR6+ Treg cells isolated from tumor-infiltrating lymphocytes or draining lymph nodes maintained similar phenotypic and suppressive characteristics ex vivo as did their counterparts isolated from peripheral blood. These results suggest that CCR6 marks activated effector or memory Treg phenotypes with superior suppressive activity in humans.

FAT1 somatic mutations in head and neck carcinoma are associated with tumor progression and survival.

In recent years, the incidence and mortality rates of head and neck squamous cell carcinoma (HNSCC) have increased worldwide. Therefore, understanding genomic alterations in HNSCC carcinogenesis is crucial for appropriate diagnosis and therapy. Protocadherin FAT1, which encodes 4588 amino acid residues, regulates complex mechanisms to promote oncogenesis or suppression of malignancies. Multiplex PCR-based next-generation sequencing (NGS) revealed FAT1 somatic mutations. The clinicopathologic implications of FAT1 in HNSCC were investigated using expression assays, and the functional role of FAT1 in HNSCC pathogenesis was determined using ectopic expression and knockdown experiments. Approximately 29% patients with HNSCC harbored damaging FAT1 mutations. InVEx algorithm identified FAT1 as a significant functional mutation burden. Each type of mutation (missense, nonsense and frameshift) accounted for nearly one-third of deleterious mutations. FAT1 mutations correlated with lower FAT1 expression in tumors. The knockdown of the endogenous expression of FAT1 and exogenous expression of crucial FAT1 domains unequivocally indicated that FAT1 suppressed the migration and invasion capability of HNSCC cells. Functional analysis suggested that nonsense mutations in FAT1 result in the loss of the suppression of tumor progression. FAT1 mutations and downregulation defined nodal involvement, lymphovascular permeation and tumor recurrence. In addition, FAT1 mutations and downregulation are independent predictors of poor disease-free survival in patients with HNSCC. This study is the first to perform multiplex PCR-based NGS to indicate marked non-synonymous FAT1 mutations in HNSCC, which are prognostic indicators. The gene analysis strategy proposed for detecting FAT1 mutations may be a valid method for mutation screening.

miR-134 targets PDCD7 to reduce E-cadherin expression and enhance oral cancer progression.

Oral squamous cell carcinoma (OSCC) is a common malignancy worldwide. This study clarified the oncogenic role of miR-134 in OSCC. Reporter assays, using both wild-type and mutant constructs, confirmed that Programmed Cell Death 7 (PDCD7) gene was a potential target of miR-134. The OSCC cells exogenously expressed miR-134 exhibited reduced PDCD7 expression. As expected, exogenous miRZip-134 expression increased PDCD7 expression in the OSCC cells; additionally, PDCD7 expression suppressed the oncogenicity of the OSCC cells. By contrast, PDCD7 knockout through gene editing increased in vitro oncogenicity and neck nodal metastasis in mice, and reduced E-cadherin (E-cad) expression. PDCD7 transactivated E-cad expression via the GC-box in the promoter. Moreover, miR-134-associated cellular transformation and E-cad downregulation was attenuated by PDCD7. Downregulation of both PDCD7 and E-cad and high levels miR-134 expression was observed in OSCC tumor tissues. Activation of the miR-134-PDCD7-E-cad pathogenesis cascade occurred early during the human and murine oral carcinogenesis process. In conclusion, the oncogenic effect of miR-134 in oral carcinoma is mediated by reducing PDCD7 and E-cad expression.

Increased Plasma Circulating Cell-Free DNA Could Be a Potential Marker for Oral Cancer.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a disease that affects patients worldwide. DNA of dead cells is released into the blood stream and may be isolated from plasma or serum samples. This DNA is termed cell-free DNA (cfDNA). cfDNA is increased in several types of malignancies. We investigated if there was a correlation between cfDNA levels and the progression of OSCC. METHODS: Using quantitative spectrometry, we measured plasma cfDNA in 121 patients with OSCC and 50 matched controls. Mann Whitney and Wilcoxon tests were used to compare differences among various clinical variants. Receiver operating characteristic (ROC) analysis was used to obtain levels suitable for the separation of the clinical subsets. Kaplan-Meier analysis was used to assess correlation with survival. RESULTS: Plasma cfDNA was significantly elevated in patients with OSCC relative to controls. Plasma cfDNA levels correlated with larger tumor size, cervical lymph node metastasis and late stage. Higher plasma cfDNA levels were associated with a poor prognosis of OSCC, which is a new finding. CONCLUSION: Plasma cfDNA could serve as a novel and easily accessible biomarker in OSCC, providing diagnostic and prognostic value.

Plasma miR-187* is a potential biomarker for oral carcinoma.

OBJECTIVES: Oral squamous cell carcinoma (OSCC) is prevalent worldwide, and survival in OSCC has not improved significantly in the past decades. MicroRNAs (miRNAs) have an important regulatory role in oral carcinogenesis. This study investigated the functional and clinical implications of miR-187* in OSCC pathogenesis. MATERIALS AND METHODS: Expression of miR-187* in OSCC tissues and patient plasma was assayed using quantitative RT-PCR. The diagnostic power was specified using receiver operator curve analysis. The phenotypic influence of miR-187* in OSCC cells was delineated using exogenous expression. RESULTS: miR-187* was upregulated in OSCC tissue relative to control mucosa. Overexpression of miR-187* enhanced the oncogenic phenotype of OSCC cells, including cell migration and anchorage-independent colony formation. Plasma miR-187* levels could be used to distinguish patients from controls with a separating power of 0.73. Patients showing a reduction in plasma miR-187* after tumor resection had a better prognosis. CONCLUSION: miR-187* plays oncogenic roles in oral carcinogenesis. Plasma miR-187* could be validated as a marker of OSCC for diagnostic uses. CLINICAL RELEVANCE: This research implied that plasma miR-187* was a diagnostic marker for patients with OSCC, and plasma miR-187* level could be a prognostic factor for OSCC patients who received ablation surgery.

Metronomic Cordycepin Therapy Prolongs Survival of Oral Cancer-Bearing Mice and Inhibits Epithelial-Mesenchymal Transition.

Cordycepin (3'-deoxyadenosine) is a natural compound abundantly found in Cordyceps sinesis in natural and fermented sources. In this study, we examined the effects of cordycepin in a human oral squamous cell carcinoma (OSCC) xenograft model. Cordycepin was administered in a regular, low-dose and prolonged schedule metronomic therapy. Two doses of cordycepin (25 mg/kg, 50 mg/kg) were administrated five days a week for eight consecutive weeks. The tumor volumes were reduced and survival time was significantly prolonged from 30.3 ± 0.9 days (control group) to 56 days (50 mg/kg group, the day of tumor-bearing mice were sacrificed for welfare consideration). The weights of mice did not change and liver, renal, and hematologic functions were not compromised. Cordycepin inhibited the OSCC cell viability in vitro (IC50 122.4-125.2 µM). Furthermore, morphological characteristics of apoptosis, increased caspase-3 activity and G2/M cell cycle arrest were observed. In wound healing assay, cordycepin restrained the OSCC cell migration. Cordycepin upregulated E-cadherin and downregulated N-cadherin protein expression, implying inhibition of epithelial-mesenchymal transition (EMT). The immunohistochemical staining of xenograft tumor with E-cadherin and vimentin validated in vitro results. In conclusion, metronomic cordycepin therapy showed effective tumor control, prolonged survival and low toxicities. Cytotoxicity against cancer cells with apoptotic features and EMT inhibition were observed.

K14-EGFP-miR-31 transgenic mice have high susceptibility to chemical-induced squamous cell tumorigenesis that is associating with Ku80 repression.

Squamous cell carcinoma (SCC) occurring in the head and neck region and the esophagus causes tremendous cancer mortality around the world. miR-31 is among the most eminently upregulated MicroRNAs in SCC, when it occurs in the head and neck region and the esophagus. We established miR-31 transgenic mouse lines, in which miR-31 is under the control of the K14 promoter. 4-nitroquinoline 1-oxide (4NQO) is a mutagen that causes double strand breaks. The transgenic mice exhibited a higher potential for tumor induction than wild-type (Wt) mice of the tongue and esophagus after 4NQO treatment. After 4NQO treatment or irradiation, p-γH2AX expression in squamous epithelium of transgenic mice was increased more than in Wt mice. Exogenous expression of miR-31 was also found to be associated with the higher p-γH2AX expression induced by 4NQO in human oral SCC (OSCC) cell lines. The repair genes PARP1 and Ku80 were validated as new targets of miR-31 in human OSCC cell lines, and were found to be downregulated in the squamous epithelium of the tongue in transgenic mice. However, only the downregulation of Ku80 was essential for maintaining the high level of p-γH2AX induced by 4NQO in OSCC cells. Inverse expression profiles for miR-31 and Ku80 were noted in human OSCC tissue. Our study identifies the high sensitivity of K14-EGFP-miR-31 transgenic mice to chemical carcinogen-induced squamous cell tumorigenesis and shows that this seems to be associated with the downregulation of Ku80 and an impairment of repair activity in squamous cells, which are mediated by miR-31.