On Oral Squamous Cell Carcinoma Research Articles

The effect of aflibercept and arsenic trioxide on the proliferation, migration and apoptosis of oral squamous cell carcinoma in vitro.

Aflibercept and arsenic trioxide drugs apply a cytotoxic effect on some human cancer cell lines. However, no more study has followed the effects of both drugs, especially arsenic trioxide, on oral squamous cell carcinoma (OCC). We used three OCC lines as a model to show the effect of these drugs on the genetically complex disease and investigate its targeted therapy. In this study, three human OCC cell lines were used from different patients. We treated cell lines with both medications to detect the effect and relevant molecular basis. First, methyl thiazolyl tetrazolium (MTT) assay was performed to detect the cytotoxicity effect and cell growth. Second, flow cytometry, gene and protein expression were performed to evaluate the anti-angiogenic effect on OCC lines. Next apoptosis was analyzed by flow cytometry. Finally, clonogenesis capacity and cell migration were assessed by colony formation assay and wound healing, respectively. Aflibercept had no cytotoxic effect on the three OCC cell lines but decreased cell growth rate. Arsenic trioxide had a significant cytotoxic effect on three cell lines. Our results demonstrated that both drugs significantly decreased endoglin, VEGFA, and VEGFB expression. In addition, Migration and colony formation assays confirmed that these drugs have significant anti-proliferative and anti-migration effect on oral carcinoma cells. These results revealed that both medications might be a potential drug for the management of oral cancer patients.

Dioscin inhibits SCC15 cell proliferation via the RASSF1A/MST2/YAP axis.

Dioscin, an extract from traditional Chinese herbal plants, displays various biological and pharmacological effects on tumors, including inhibition of cell proliferation and induction of DNA damage. However, the effects of dioscin on oral squamous cell carcinoma (OSCC) cells are not completely understood. The present study aimed to evaluate the impact of dioscin on OSCC cell proliferation. Cell Counting Kit-8 and 5-ethynyl-2′-deoxyuridine incorporation assays were performed to assess cell proliferation. Flow cytometry was conducted to detect alterations in the cell cycle and cell apoptosis. Western blotting and coimmunoprecipitation were performed to determine protein expression levels. In SCC15 cells, dioscin treatment significantly induced cell cycle arrest, increased apoptosis and inhibited proliferation compared with the control group. Mechanistically, the tumor suppressor protein Ras association domain-containing protein 1A (RASSF1A) was activated and oncoprotein yes-associated protein (YAP) was phosphorylated by dioscin. Furthermore, YAP overexpression and knockdown reduced and enhanced the inhibitory effects of dioscin on SCC15 cells, respectively. In summary, the results demonstrated that, compared with the control group, dioscin upregulated RASSF1A expression in OSCC cells, which resulted in YAP phosphorylation, thus weakening its transcriptional coactivation function, enhancing cell cycle arrest and apoptosis, and inhibiting cell proliferation. The present study indicated that dioscin may serve as a therapeutic agent for OSCC.

The selective toxicity of superparamagnetic iron oxide nanoparticles (SPIONs) on oral squamous cell carcinoma (OSCC) by targeting their mitochondria.

In recent years, many researchers have madetremendous efforts into using nanotechnology in biomedical applications and science, such as magnetic resonance imaging, drug delivery, and in particular, oncological therapeutic via superparamagnetic iron oxide nanoparticles (SPIONs). Head and neck squamous cell carcinoma (HNSCC) and especially oral squamous cell carcinoma (OSCC) have been a serious and ongoing concern. There are manystrong emphases on the importance of toxic mechanisms due to oxidative stress and specifically, the changed cellular response. Therefore, our study was designed to evaluate the effects of SPIONs on OSCC mitochondriabecause of the usefulness of the application of these nanoparticlesin cancer treatment and diagnosis. An increased level of reactive oxygen species (ROS) is one of the substantial mechanisms found for SPIONs in this study,andinitially originated from disruption of the electron transfer chain shown by a decrease in mitochondrial succinate dehydrogenaseactivity. Increased ROS formation subsequently followed a decline of mitochondrial membrane potential, the release of mitochondrial cytochrome complex, and mitochondrial swelling in the OSCC mitochondria compared with almost no effect in normal mitochondria. In addition, the SPIONs decreased cell viability and increased lipid peroxidationlevel and caspase-3 activity in OSCC cells. The results represented that the exposure to the SPIONs induced selective toxicity only on the OSCC but not normal mitochondria. Based on our findings, we finally concluded that the SPIONs may be considered as a potential therapeutic candidate for the treatment of OSCC.

Identification of E2F transcription factor 7 as a novel potential biomarker for oral squamous cell carcinoma

BackgroundAs a tumor-accelerating transcriptional factor, E2F transcription factor 7 (E2F7) was up-regulated in many forms of cancers. Nevertheless, little has been reported about the impacts of E2F7 on oral squamous cell carcinoma (OSCC). Here, we aimed to probe whether E2F7 had influences on OSCC and its potential mechanism.MethodsThe expression of E2F7 in OSCC tissues was analyzed using the data acquired from TCGA and ONCOMINE databases. E2F7 prognostic value in OSCC patients was analyzed utilizing TCGA database. The expression of E2F7 in OSCC cell lines was detected by qRT-PCR. Gain-and loss-function of E2F7 assays in TCA-83 and CAL27 cells were performed respectively to inquire the function of E2F7. Western blotting was applied to test the alternations of EMT-related markers.ResultsIn OSCC tissues, E2F7 was highly expressed. Besides, high expression of E2F7 predicted worse prognosis in OSCC patients. Moreover, E2F7 was over-expressed in TCA-83, HSC-4 and CAL27 (all OSCC cell lines) cells relative to that in HNOK (a normal cell line) cells. Gain-and loss-function assays displayed that deficiency of E2F7 suppresses CAL27 cell growth, migration, invasion and E2F7 high-expression resulted in inverse outcomes in TCA-83 cells. Finally, we found that silencing of E2F7 facilitated E-cadherin protein expression level and reduced N-cadherin, Vimentin and Snail protein levels in CAL27 cells, whilst E2F7 high-expression exhibited the opposite effects in TCA-83 cells.ConclusionsThese outcomes indicated that E2F7 performs a carcinogenic role in OSCC, which provides a theoretical basis for the therapeutic strategies of OSCC.

Prognostic role of preoperative D-dimer, fibrinogen and platelet levels in patients with oral squamous cell carcinoma

BackgroundThe relationship between cancer and coagulation has been intensively studied in recent years; however, the effects of coagulation factors on oral squamous cell carcinoma (OSCC) have rarely been reported. This study aimed to investigate the relationship between preoperative D-dimer (DD), fibrinogen (FIB), platelets (PLT) and OSCC, as well as the prognostic value of DD, FIB and PLT in OSCC.MethodsWe retrospectively investigated a total of 202 patients with OSCC treated at Guanghua Hospital of Stomatology, Sun Yat-sen University. Baseline demographic and clinicopathological information as well as both preoperative and postoperative DD, FIB and PLT results were collected from each patient, and patients with primary OSCC were followed up for disease progression, death or the end of the study. The correlations between preoperative DD, FIB, PLT and other clinical features, as well as the therapeutic effect and PFS were analysed statistically, and postoperative DD and surgical parameters were also analysed.ResultsPreoperative DD was significantly correlated with T stage, N stage, clinical stage and relapse of OSCC (P = 0.000, 0.001, 0.000 and 0.000, respectively). Univariate Cox regression analyses showed that high preoperative DD predicted poor prognosis in patients with OSCC (HR = 2.1, P = 0.033), while FIB and PLT showed no prognostic values. Postoperative DD was significantly correlated with preoperative DD and surgical type but not the duration of surgery (P = 0.005, 0.001 and 0.244, respectively).ConclusionIn this study, we suggested that high preoperative DD level may serve as an indicator for synchronous neck dissection in patients with T1, 2 OSCC, and the elevated DD level might be the marker of disease progression in patient follow up.

Cytotoxic Role of Chlorogenic Acid on Oral Squamous Cell Carcinoma Cell Line.

The aim of the present study was to determine the cytotoxic, anticancerous and antiproliferative activity of CGA on oral squamous cell carcinoma (OSCC) cell line (KB) and to evaluate expression level of p21 and p53 in these CGA treated OSCC cell line. Different concentrations of CGA varying from 500 to 2500µM were tested on OSCC cell line. Trypan blue and MTT assay were performed to establish IC50. DNA fragmentation and expression level of p21 and p53 were evaluated with the help of RT-PCR. CGA exerted antiproliferative and cytotoxic effect on OSCC (KB) cell line. Statistically significant results were found regarding effect of different CGA concentrations on KB cell line with IC50 at 1800µM. No DNA fragmentation was observed. p21 and p53 expression were down regulated after CGA treatment. CGA revealed neither apoptosis nor damage to the nucleus after DNA fragmentation. Antiproliferative role of CGA was hinted by down regulation of p53 and p21 probably through cell cycle arrest at G1-S phase. It was reaffirmed that CGA a natural chemo preventive agent could enhance the treatment modalities with minimal side effects.

Multi-omics Analysis of Ferroptosis Regulation Patterns and Characterization of Tumor Microenvironment in Patients with Oral Squamous Cell Carcinoma.

Ferroptosis is a newly recognized mechanism of regulated cell death. It was reported to be highly associated with immune therapy and chemotherapy. However, its mechanism of regulation in the tumor microenvironment (TME) and influence on oral squamous cell carcinoma (OSCC) therapy are unknown. We identified a ferroptosis-specific gene-expression signature, an FPscore, developed by a principal component analysis (PCA) algorithm to evaluate the ferroptosis regulation patterns of individual tumor. Multi-omics analysis of ferroptosis regulation patterns was conducted. Three distinct ferroptosis regulation subtypes, which linked to outcomes and the clinical relevance of each patient, were established. A high FPscore of patients with OSCC was associated with a favorable prognosis, a ferroptosis-related immune-activation phenotype, potential sensitivities to the chemotherapy and immunotherapy. Importantly, a high FPscore correlated with a low gene copy number burden and high immune checkpoint expressions. We validated the prognostic value of the FPscore using independent immunotherapy and pan-cancer cohorts. Comprehensive evaluation of individual tumors with distinct ferroptosis regulation patterns provides new mechanistic insights, which may be clinically relevant for the application of combination therapies in OSCC.

The anti-tumor effects of evodiamine on oral squamous cell carcinoma (OSCC) through regulating advanced glycation end products (AGE) / receptor for advanced glycation end products (RAGE) pathway

ABSTRACT Evodiamine (EVO) is emerging as a novel anti-tumor drug, which is involved in the inhibition of cell proliferation and apoptosis. High-Mobility Group Box 1 (HMGB1)/RAGE is involved in invasive behavior of OSCC cells and angiogenesis. In this study, we evaluated the potential of EVO in OSCC in vitro and in vivo. We found that RAGE silencing suppressed HSC-4 cell proliferation and invasion, and tube formation of HUVEC. EVO showed marked inhibitory effects on the malignant behaviors of HSC-4 cells in a dose-dependent manner. Further experiments revealed that the RAGE overexpression was able to markedly block the effects of EVO on cell proliferation and invasion, and tube formation. By analyzing the expression of High-Mobility Group Box 1 (HMGB1) and RAGE in HSC-4 cells, the result showed that EVO slightly reduced HMBG1 levels and dramatically decreased RAGE levels, while RAGE overexpression did have no marked influences on HMBG1 levels. The anti-tumor effects of EVO were further confirmed in mouse oral squamous cell carcinoma xenograft models. Remarkable anti-tumor effects of EVO were also demonstrated, as presented by reduced tumor size and levels of HMBG1 and RAGE in tumor tissue of mouse oral squamous cell carcinoma xenograft models. The results demonstrated that EVO has a direct binding effect on HMGB1, but it may be involved in degrading the protein. More importantly, it can reduce the activity of RAGE pathway by affecting the binding between HMBG1 and RAGE. To conclude, EVO inhibited proliferation, invasion and angiogenesis of OSCC through affecting the downstream signal transduction system of AGE/RAGE by targeting RAGE.

The anti-tumor effects of imidazolium salts on oral squamous cell carcinoma.

Imidazolium salts (IS), ionic derivatives of neutral imidazoles, have properties that can be adjusted by structural modifications to their cations and anions, which makes this particular class of compounds a promising option for developing biologically active compounds. The anti-tumor effects of the IS 1-n-butyl-3-methylimidazolium chloride (C4 MImCl), 1-n-decyl-3-methylimidazolium chloride (C10 MImCl), 1-n-hexadecyl-3-methylimidazolium chloride (C16 MImCl), 1-n-hexadecyl-2,3-dimethylimidazolium chloride (C16 M2 ImCl), 1-n-octadecyl-3-methylimidazolium chloride (C18 MImCl), 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C16 MImMeS), and 1-n-hexadecyl-2,3- dimethylimidazolium methanesulfonate (C16 M2 ImMeS) on oral squamous cell carcinoma (OSCC) have been studied here. Oral squamous cell carcinoma cells (CAL27) were incubated with increasing IS doses and then submitted to proliferation (2D), cell death (2D) and spheroid assay (3D). The IS anti-tumor effect was dependent on both its N-alkyl chain length and anion, whereby C16 MImCl proved to be more effective in combination for inhibiting cell proliferation and cell-cell adhesion, outperforming the methylated C16 M2 ImCl derivative and, most importantly, the gold standard-cisplatin. In addition, C16 MImCl had little effect on keratinocytes and more pronounced effects on more aggressive tumor cells. It also exhibited similar effects on inducing cell death when compared to Cisplatin. This compound spread to a greater area of the tumor sphere and produced an enhanced number of apoptotic and necrotic cells in the tumor cell line, demonstrating only a small rise in the healthy cells. These data indicate that the effect of C16 MlmCl on OSCC is promising, as it is selective for cancer cells.

Effects of an elemental diet, Elental®, may differ between healthy oral cells and oral cancer cells.

The effectiveness of an elemental diet(ED), Elental®, against radiotherapy‑ or chemoradiotherapy‑induced oral mucositis was previously reported. However, the administration of additional nutrition or an ED in patients with oral cancer may also provide extra nutrition for cancer cells, which could result in cancer development. At present, it remains unclear whether the beneficial effects of an ED are likely to surpass its potential harmful effects on oral cancer treatment. In the present study, we aimed to clarify whether Elental® has different effects on a healthy human oral keratinocyte(HOK) cell line compared with its effects on oral squamous cell carcinoma (OSCC) cell lines (HSC2, HSC3, HSC4). The efficacy of Elental® was compared in relation to the growth and migration ability of HOK and OSCC cell lines using MTT assay and migration assay, respectively. In addition, whole transcriptome analysis and network analysis were performed to determine the difference in the mechanism of action of Elental® between HOK and HSC2 cells. In addition, Elental® promoted growth and migration ability of‑malnourished and 5‑fluorouracil(5‑FU)‑treated damaged HOK cells cultured in low nutrition medium (0% growth supplement). However, Elental® did not affect the growth ability of 5‑FU‑treated damaged HSC2 cell line in low nutrition medium (0 or 1% fetal bovine serum (FBS), as well as the growth ability of HSC3 and HSC4 cell lines in medium containing 0%FBS. Elental® pre‑treatment also enhanced the apoptosis‑inducing effect of anticancer agents against OSCC cells. In addition, whole transcriptome analysis and Ingenuity Pathways Analysis(IPA) data suggested that Elental® may help in the proliferation and survival of HOK through the induction of ERK. Moreover, Elental® added stress to HSC2 cells through the induction of the endoplasmic reticulum stress response marker, BiP and GRP94. The results showed that Elental® may add stress to HSC2 cells and provide growth stimulation to HOK. These findings suggest that the effects of Elental® on healthy oral cells and oral cancer cells may differ.

In Vitro Study of Synergic Effect of Cisplatin and Low Molecular Weight Heparin on Oral Squamous Cell Carcinoma.

ObjectivesTo evaluate the possible synergic effect of cisplatin and low molecular weight heparin (LMWH) on oral squamous cell carcinoma (OSCC).Materials and MethodsCisplatin and enoxaparin sodium, alone or in combination, were administered at doses of 1, 2, 4, 8 and 10 µM and 0.1, 0.5, 1, 5, 10, 50, and 100 µg/ml, respectively, to the H357 human OSCC line. The effects on cell viability and apoptosis were evaluated after 24, 48, and 72 h and on cell migration after 18 and 24 h.Results10 µM concentration of cisplatin produced the greatest decrease in cell viability, with significant differences at 24 (p=0.009), 48 (p=0.001) and 72 h (p = 0.003); the 100 µg/ml dose of enoxaparin produced the greatest decrease in cell viability but without significant differences (p>0.05). When different concentrations of cisplatin and enoxaparin were combined, it was found that 100 µg/ml enoxaparin sodium produced the greatest synergic effect on cell viability reduction. In analyses of apoptosis and cell migration, it was found that the combination of cisplatin at 8 or 10 μM and 100 μg/ml enoxaparin produced a higher rate of apoptosis at 24, 48, and 72 h and a greater reduction in cell migration at 18 and 24 h.ConclusionsA combination of cisplatin and enoxaparin sodium shows a synergic effect that reduces cell viability and cell migration capacity and increases the apoptosis of human OSCC cells.Clinical relevanceEnoxaparin may be beneficial in chemotherapy for patients with OSCC; this finding requires further clinical and laboratory investigation.

Effects of Maackia amurensis seed lectin (MASL) on oral squamous cell carcinoma (OSCC) gene expression and transcriptional signaling pathways.

Oral cancer causes over 120,000 deaths annually and affects the quality of life for survivors. Over 90% of oral cancers are derived from oral squamous cell carcinoma cells (OSCCs) which are generally resistant to standard cytotoxic chemotherapy agents. OSCC cells often exhibit increased TGFβ and PDPN receptor activity compared to nontransformed oral epithelial cells. Maackia amurensis seed lectin (MASL) can target the PDPN receptor and has been identified as a novel agent that can be used to treat oral cancer. However, mechanisms by which MASL inhibits OSCC progression are not yet clearly defined. Here, we performed cell migration and cytotoxicity assays to assess the effects of MASL on OSCC motility and viability at physiologically relevant concentrations. We then performed comprehensive transcriptome analysis combined with transcription factor reporter assays to investigate the how MASL affects OSCC gene expression at these concentration. Key data were then confirmed by western blotting to evaluate the effects of MASL on gene expression and kinase signaling activity at the protein level. MASL significantly affected the expression of about 27% of approximately 15,000 genes found to be expressed by HSC-2 cells used to model OSCC cells in this study. These genes affected by MASL include members of the TGFβ-SMAD, JAK-STAT, and Wnt-βCTN signaling pathways. In particular, MASL decreased expression of PDPN, SOX2, and SMAD5 at the RNA and protein levels. MASL also inhibited SMAD and MAPK activity, and exhibited potential for combination therapy with doxorubicin and 5-fluorouracil. Taken together, results from this study indicate that MASL decreases activity of JAK-STAT, TGFβ-SMAD, and Wnt-βCTN signaling pathways to inhibit OSCC growth and motility. These data suggest that further studies should be undertaken to determine how MASL may also be used alone and in combination with other agents to treat oral cancer.

Metformin inhibits proliferation of oral squamous cell carcinoma cells by suppressing proteolysis of nerve growth factor receptor

ObjectiveWe aimed to explore the effects of metformin on oral squamous cell carcinoma (OSCC) cell proliferation and the associated molecular mechanisms. MethodsWe established an OSCC model in SCC15 cells overexpressing nerve growth factor receptor (NGFR) or the N-terminal region (aa 1–250; NGFR-N), and assessed cell proliferation by CCK-8 assay, colony formation assay, and cell cycle analysis. Levels of NGFR and related genes and proteins were detected by qPCR and western blotting, and NGFR and NGFR-N affinity for p53 was assessed by immunoprecipitation assay. Additionally, the effects of NGFR and NGFR-N on p53 binding with its downstream gene promoters were analyzed by chromatin immunoprecipitation. ResultsMetformin inhibited OSCC cell proliferation and blocked NGFR proteolysis, thereby reducing the generation of its intracellular domain and NGFR-N. Moreover, compared with NGFR, NGFR-N showed higher affinity for p53 and more strongly inactivated p53 to promote cell proliferation. Furthermore, upregulation of NGFR-N downregulated levels of p53-specific downstream transcripts and proteins, whereas these levels were significantly upregulated in metformin-treated cells overexpressing NGFR. ConclusionsThese results showed that metformin inhibited cell proliferation by suppressing NGFR proteolysis, thereby promoting its antitumor effect in OSCC and offering novel insight into a role for metformin in OSCC treatment.

Cyclin G2 Inhibits Oral Squamous Cell Carcinoma Growth and Metastasis by Binding to IGFBP3 and Regulating the FAK-SRC-STAT Signaling Pathway.

The cell cycle protein cyclin G2 is considered a tumor suppressor. However, its regulatory effects and potential mechanisms in oral cancers are not well understood. This study aimed to investigate the effect of cyclin G2 on oral squamous cell carcinoma (OSCC). The data from 80 patients with OSCC were utilized to predict the abnormal expression of cyclin G2. The proliferation and metastasis were determined by a cell counting Kit-8 assay, flow cytometry, a wound-healing assay, and a cell invasion assay. The expression of key proteins and genes associated with the cyclin G2 signaling pathways was determined by western blotting and real-time PCR, respectively. The orthotopic nude mice model was established by a mouth injection of SCC9 cells overexpressing cyclin G2. We showed that the low level of cyclin G2 in OSCC, which is negatively correlated with clinical staging, was a negative prognostic factor for the disease. We also found that cyclin G2 inhibited the proliferation, metastasis, and blocked the cell cycle at G1/S of OSCC cells, suggesting that cyclin G2 has an inhibitory effect in OSCC. Mechanistically, cyclin G2 inhibited the growth and metastasis of OSCC by binding to insulin-like growth factor binding protein 3 (IGFBP3) and regulating the focal adhesion kinase (FAK) -SRC-STAT signal transduction pathway. Cyclin G2 competed with integrin to bind to IGFBP3; the binding between integrin and IGFBP3 was reduced after cyclin G2 overexpression, thereby inhibiting the phosphorylation of FAK and SRC. These results showed that cyclin G2 inhibited the progression of OSCC by interacting with IGFBP3 and that it may be a new target for OSCC treatment.

YAP signaling induces PIEZO1 to promote oral squamous cell carcinoma cell proliferation.

Most cancer cells are exposed to altered extracellular environments, such as an increase in extracellular matrix (ECM) stiffness and soluble signals consisting of growth factors and cytokines. It is therefore conceivable that changes in tumor extracellular environments affect tumor cell behavior. The Hippo pathway reportedly responds to the extracellular environment and regulates the nuclear localization of the transcription co-activator, yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). Inactivation of the Hippo pathway with nuclear translocation of YAP/TAZ stimulates cell proliferation. Its pathway also regulates gene expression, but the precise molecule(s) meditating the cell-proliferating effect of YAP signaling on oral squamous cell carcinoma (OSCC) is unclear. First, we examined the effects of YAP signaling on OSCC tumorigenesis. Loss-of-function experiments using siRNA or an inhibitor, and immunohistochemical analyses of tissue specimens obtained from OSCC patients demonstrated that YAP signaling was involved in OSCC cell proliferation. Second, we identified Piezo-type mechanosensitive ion channel component 1 (PIEZO1), a Ca2+ channel, as a transcriptional target of YAP signaling and showed that elevated PIEZO1 was required for PIEZO1 agonist-dependent Ca2+ entry and cell proliferation in OSCC cells. Experiments using three-dimensional and suspension culture revealed that PIEZO1 was involved in OSCC cellular growth. Finally, YAP overexpression in the nucleus and/or cytoplasm was immunohistochemically detected in tumor lesions with frequent expression of both PIEZO1 and Ki-67, but not in non-tumor regions of OSCC specimens. These results suggest that the YAP/PIEZO1 axis promotes OSCC cell growth. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

RETRACTED: circPHIP promotes oral squamous cell carcinoma progression by sponging miR-142-5p and regulating PHIP and ACTN4 expression

Circular RNA (circRNA) is a newly discovered class of noncoding RNAs that plays key regulatory role in pathological development, including the regulation of several solid tumors. However, the effects of circRNA expression on oral squamous cell carcinoma (OSCC) remain unclear. With the use of high-throughput RNA sequencing data on eight paired oral cancer and adjacent healthy tissues, we observed that circRNA derived from the gene encoding pleckstrin homology domain-interacting protein (circPHIP) was highly expressed in OSCC. Additionally, circPHIP was highly expressed in other OSCC-related cell lines and was associated with tumor metastasis, TNM stage, and human papilloma virus infection status. The inhibition of circPHIP expression reduced OSCC cell migration, invasion, and proliferation. We found that circPHIP could adsorb microRNA (miR)-142-5p and upregulate the expression of PHIP and alpha-actinin 4 (ACTN4), both of which are potential oncogenes closely related to OSCC prognosis. The inhibition of miR-142-5p or overexpressing PHIP or ACTN4 reversed the circPHIP depletion-induced attenuation of OSCC malignancy. In conclusion, circPHIP is overexpressed in OSCC and enhances its malignancy via an miR-142-5p/PHIP-ACTN4/AKT serine/threonine kinase 1 signaling axis. Therefore, circPHIP may represent a novel target for treating OSCC.

Kava constituents exert selective anticancer effects in oral squamous cell carcinoma cells in vitro

Kava is a beverage made from the ground roots of the plant Piper Methysticum. Active compounds of Kava have previously been demonstrated to exert an antiproliferative effect through cell cycle arrest and promotion of apoptosis. Our aim was to investigate the in vitro effects of the main constituents derived from Kava on oral squamous cell carcinoma (OSCC) activity.Gas chromatography mass spectrometry (GCMS) was used to characterise the main constituents of two Kava preparations. Cell proliferation was assessed in two human OSCC cell lines (H400 and BICR56) and in normal oral keratinocytes (OKF6) treated with the identified Kava constituents, namely Flavokawain A (FKA), Flavokawain B (FKB), yangonin, kavain and methysticin using an MTS in vitro assay. Cell migration at 16 h was assessed using a Transwell migration assay. Cell invasion was measured at 22 h using a Matrigel assay. Cell adhesion was assessed at 90 min with a Cytoselect Adhesion assay. The two Kava preparations contained substantially different concentrations of the main chemical constituents. Treatment of malignant and normal oral keratinocyte cell lines with three of the identified constituents, 10 μg/ml FKA, 2.5 μg/ml FKB and 10 μg/ml yangonin, showed a significant reduction in cell proliferation in both H400 and BICR56 cancer cell lines but not in normal OKF6 cells. Remarkably, the same Kava constituents induced a significant reduction of OSCC cell migration and invasion. We have demonstrated, for the first time, that Kava constituents, FKA, FKB and yangonin have potential anticancer effects on OSCC. This highlights an avenue for further research of Kava constituents in the development of future cancer therapies to prevent and treat OSCC.

Macrophage‑derived exosomes attenuate the susceptibility of oral squamous cell carcinoma cells to chemotherapeutic drugs through the AKT/GSK‑3β pathway.

Although chemotherapy is initially effective in debulking tumor mass in a number of different types of malignancy, tumor cells gradually acquire chemoresistance and frequently progress to advanced clinical stage. Accumulating evidence has indicated that the tumor sensitivity to several chemotherapeutic drugs is regulated by tumor stromal cells including macrophages. However, the role of macrophages in the efficacy of chemotherapeutics on oral squamous cell carcinoma (OSCC) cells is poorly understood. In the present study, the effects of macrophage-secreted exosomes on the sensitivity of OSCC cells towards chemotherapeutic agents were examined. Specifically, the effects of exosomes derived from THP-1 cells and primary human macrophages (PHM) were assessed on the chemosensitivity of OSC-4 cells treated with 5-fluorouracil (5-FU) and cis-diamminedichloroplatinum (CDDP). The THP-1- and PHM-derived exosomes promoted dose-dependent proliferation, decreased the proliferative inhibitory effects of 5-FU and CDDP and decreased apoptosis in OSC-4 cells through activation of the AKT/glycogen synthase kinase-3β signaling pathway. LY294002, a PI3K inhibitor, and MK-2206, an AKT inhibitor, were both able to suppress the observed decrease in sensitivity to chemotherapeutic agents induced by exosomes. Overall, the data from the present study suggested that the macrophage-derived exosomes may decrease the sensitivity to chemotherapeutic agents in OSCC cells. Thus, targeting the interaction between OSCC cells and macrophage-derived exosomes may be considered as a therapeutic approach to improve the chemosensitivity of the tumor microenvironment in oral cancer.

956P Combined accuracy of computed tomography and magnetic resonance imaging in detecting level wise metastatic neck nodes and extracapsular spread

The presence of metastatic neck node and extracapsular spread(ECS) has a poorer survival impact on oral squamous cell carcinoma(OSCC) patients. The debate of addressing the neck in superficial tumors <3 mm is still ongoing. Moreover, ECS has been recently added in the new clinical staging system and imaging plays an important role for the same. There are several studies reporting accuracy of individual imaging modalities in detecting metastatic node. However, combined use of these imaging techniques may be supplementary, especially with equivocal finding.

Inhibiting the PI3K/Akt, NF-κB signalling pathways with syringic acid for attenuating the development of oral squamous cell carcinoma cells SCC131.

To evaluate the anti-inflammatory and antiproliferative effect of syringic acid (SRA) on oral squamous cell carcinoma (OSCC) SCC131 cells via suppression of NF-κB-induced PI3K/Akt signalling pathway. The present study assesses the anticancer effects of SRA alongside human oral cancer (HOC) SCC131 cells through the fabrication of reactive oxygen species (ROS) and activated apoptosis. DAPI and Rh-123 staining were used to assess the apoptotic nuclear characteristic, mitochondrial membrane potential, cell adhesion and migration by fluorescence microscope with SRA treatment. Syringic acid inhibits cell viability (IC50 values of 25µm), adhesion, migration and induced apoptosis. MTT assay demonstrated SRA-induced apoptotic events, inhibition of invasion and angiogenic signalling in SCC131 cell line. Furthermore, SRA treated with SCC131 cells suppresses the protein expression of inflammatory, angiogenesis and PI3K/Akt signalling pathways. It is suggested that SRA prevents the translocation of NF-κB and PI3K/Akt activated products to the nucleus, thereby suppressing angiogenesis via downregulation of vascular endothelial growth factor. Therefore, addition of SRA to SCC131 cells may provide a promising natural therapeutic strategy against squamous cell carcinomas with potential application in clinical analysis.