On Oral Squamous Cell Carcinoma Cell Research Articles

Verbascoside inhibits oral squamous cell carcinoma cell proliferation, migration, and invasion by the methyltransferase 3-mediated microRNA-31-5p/homeodomain interacting protein kinase 2 axis

ObjectiveThe study aimed to investigate the effects of verbascoside on oral squamous cell carcinoma (OSCC) cellular behaviors and underlying molecular mechanisms. DesignFor this purpose, SCC9 and UM1 cell lines were treated with verbascoside, and their biological behaviors, including proliferation, migration, and invasion, were evaluated using cell counting kit-8, 5-Ethynyl-2′-deoxyuridine, and Transwell assays. The expression of methyltransferase-3 (METTL3), microRNA (miR)− 31–5p, and homeodomain interacting protein kinase-2 (HIPK2) were examined using quantitative real-time polymerase chain reaction (qRT-PCR). The interaction between METTL3 and miR-31–5p was evaluated by RNA immunoprecipitation and methylated RNA immunoprecipitation, while the interaction between miR-31–5p and HIPK2 was evaluated by dual-luciferase reporter analysis. ResultsThe results indicated inhibition of OSCC cell proliferation, migration, and invasion post verbascoside treatment. Similarly, METTL3 was upregulated in OSCC cells and was inhibited post-verbascoside treatment. Overexpressing METTL3 promoted the cellular processes. Moreover, miR-31–5p was upregulated in OSCC cells, where METTL3 facilitated the processing of miR-31–5p in an N6-methyladenosine (m6A)-dependent manner. The HIPK2 served as miR-31–5p target, where overexpressing miR-31–5p or HIPK2 knockdown reversed the suppression of verbascoside-induced biological behaviors. ConclusionsVerbascoside inhibited the progression of OSCC by inhibiting the METTL3-regulated miR-31–5p/HIPK2 axis. These findings suggested that verbascoside might be an effective drug for OSCC therapy.

Potential targets of diosgenin for the treatment of oral squamous cell carcinoma and their bioinformatics and transcriptional profiling analyses

Diosgenin can inhibit the proliferation and cause apoptosis of various tumor cells, and its inhibitory effect on oral squamous cell carcinoma (OSCC) and its mechanism are still unclear. In this study, we predicted the targets of diosgenin for the treatment of OSCC through the database, then performed bioinformatics analysis of the targets, and further verified the effect of diosgenin on the activity of OSCC cell line HSC-3, the transcriptional profile of the targets and the molecular docking of the targets with diosgenin. The results revealed that there were 146 potential targets of diosgenin for OSCC treatment, which involved signaling pathways such as Ras, TNF, PI3K-AKT, HIF, NF-κB, and could regulate cellular activity through apoptosis, autophagy, proliferation and differentiation, inflammatory response, DNA repair, etc. Diosgenin significantly inhibited HSC-3 cell activity. The genes such as AKT1, MET1, SRC1, APP1, CCND1, MYC, PTGS2, AR, NFKB1, BIRC2, MDM2, BCL2L1, MMP2, may be important targets of its action, not only their expression was regulated by diosgenin but also their proteins had a high binding energy with diosgenin. These results suggest that diosgenin may have a therapeutic effect on OSCC through AKT1, MMP2 and other targets and multiple signaling pathways, which is of potential clinical value.

Evodiamine inhibits EPRS expression to regulate glutamate metabolism and proliferation of oral squamous cell carcinoma cells.

The effects of evodiamine (EVO) on oral squamous cell carcinoma (OSCC) are not yet understood. Based on our earlier findings, we hypothesized that evodiamine may affect OSCC cell proliferation and glutamate metabolism by modulating the expression of EPRS (glutamyl-prolyl-tRNA synthetase 1). From GEPIA, we obtained EPRS expression data in patients with OSCC as well as survival prognosis data. An animal model using Cal27 cells in BALB/c nude mice was established. The expression of EPRS was assessed by immunofluorescence, Western blotting, and quantitative PCR. Glutamate measurements were performed to evaluate the impact of evodiamine on glutamate metabolism of Cal27 and SAS tumor cells. transient transfection techniques were used to knock down and modulate EPRS in these cells. EPRS is expressed at higher levels in OSCC than in normal tissues, and it predicts poor prognosis in patients. In a nude mouse xenograft model, evodiamine inhibited tumor growth and the expression of EPRS. Evodiamine impacted cell proliferation, glutamine metabolism, and EPRS expression on Cal27 and SAS cell lines. In EPRS knockdown cell lines, both cell proliferation and glutamine metabolism are suppressed. EPRS's overexpression partially restores evodiamine's inhibitory effects on cell proliferation and glutamine metabolism. This study provides crucial experimental evidence supporting the potential therapeutic application of evodiamine in treating OSCC. Evodiamine exhibits promising anti-tumor effects by targeting EPRS to regulate glutamate metabolism.

Ferroptosis induced by plasma-activated Ringer's lactate solution prevents oral cancer progression.

This study aimed to investigate the effect of plasma-activated Ringer's lactate solution (PAL) on oral squamous cell carcinoma (OSCC) cells and carcinogenic processes with a particular focus on iron and collagenous matrix formation. We used three OSCC cell lines, one keratinocyte cell line, and two fibroblast lines, and cell viability assays, immunoblotting, flow cytometry, and transmission electron microscopy were performed to evaluate the effect and type of cell death. The effect of PAL treatment on lysyl oxidase (LOX) expression was investigated invitro and invivo. Tamoxifen-inducible Mob1a/b double-knockout mice were used for the invivo experiment. PAL killed OSCC cells more effectively than the control nontumorous cells and suppressed cell migration and invasion. Ferroptosis occurred and the protein level of LOX was downregulated in cancer cells invitro and invivo. Additionally, PAL improved the survival rate of mice and suppressed collagenous matrix formation. We demonstrated that PAL specifically kills OSCC cells and that ferroptosis occurs invitro and invivo. Furthermore, PAL can prevent carcinogenesis and improve the survival rate of oral cancer, especially tongue cancer, by changing collagenous matrix formation via LOX suppression.

Peroxiredoxin 1 regulates crosstalk between pyroptosis and autophagy in oral squamous cell carcinoma leading to a potential pro-survival

Peroxiredoxin 1 (Prdx1), a vital antioxidant enzyme, has been proven to play an important role in the occurrence and development of cancers, but its effects on oral squamous cell carcinoma (OSCC) remain unclear. Here, we performed bioinformatics analysis and immunohistochemical (IHC) staining to confirm that Prdx1 was higher in OSCC tissues than in normal tissues. Consistently, RT-PCR and Western blot showed elevated Prdx1 expression in OSCC cell lines compared to human oral keratinocytes (HOK), which could be knockdown by small interfering RNA (siRNA) and Lentiviral vector delivery of short hairpin RNA (shRNA). Prdx1 silencing significantly blocked OSCC cell proliferation and metastasis, as evidenced by the CCK8, colony formation, in vivo tumorigenesis experiment, wound healing, transwell assays, and changes in migration-related factors. siPrdx1 transfection increased intracellular reactive oxygen species (ROS) levels and provoked pyroptosis, proved by the upregulation of pyroptotic factors and LDH release. Prdx1 silencing ROS-independently blocked autophagy. Mature autophagosome failed to form in the siPrdx1 group. Up-regulated autophagy limited pyroptosis triggered by Prdx1 deficiency, and down-regulated pyroptosis partly reversed siPrdx1-induced autophagy defect. Collectively, Prdx1 regulated pyroptosis in a ROS-dependent way and modulated autophagy in a ROS-independent way, involving the crosstalk between pyroptosis and autophagy.

ENAH-202 promotes cancer progression in oral squamous cell carcinoma by regulating ZNF502/VIM axis.

We aimed to demonstrate the regulatory effect of long non-coding RNA (lncRNA) ENAH-202 on oral squamous cell carcinoma (OSCC) development as well as its molecular mechanism. We detected ENAH-202 expression in OSCC tissues and cell lines by quantitative real-time PCR (qPCR). The biological function of ENAH-202 was assessed invitro and invivo using CCK-8, colony formation assays, transwell assays, xenograft formation, and tail vein injection. The further molecular mechanism by which ENAH-202 promoted OSCC progression was identified using RNA pull-down, LS-MS/MS analysis, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP) assays. ENAH-202 was significantly upregulated in OSCC tissues and cells. ENAH-202 promoted OSCC cell proliferation, migration, and invasion invitro and invivo. The expression of enabled homolog (ENAH) and epithelial-to-mesenchymal transition (EMT)-related proteins was changed with the expression of ENAH-202. Moreover, ENAH-202 promoted the transcription of Vimentin (VIM) by binding with ZNF502, which can help ENAH-202 promote OSCC progression. ENAH-202 facilitated OSCC cell proliferation and metastasis by regulating ZNF502/VIM axis, which played an important role in OSCC progression.

The role of phosphoprotein associated with glycosphingolipid-enriched microdomains 1 (PAG1) in regulating the progression of oral squamous cell carcinoma

ObjectiveThe aim of this study was to explore the role of the tumor suppressor phosphoprotein associated with glycosphingolipid-enriched microdomains 1 (PAG1) on oral squamous cell carcinoma (OSCC) and its molecular mechanism. DesignImmunohistochemistry detected the expression of PAG1 in normal and tumor tissues. The PAG1 overexpressed OSCC cell lines were constructed by lentivirus transfection. Cell Counting Kit-8 assay (CCK-8), clone formation and flow cytometry evaluated the impact of PAG1 on the proliferation and apoptosis of OSCC cells. RNA sequencing (RNA-seq) detected the changes in intracellular genes, and transmission electron microscope (TEM) was used to compare the number of autophagosomes in OSCC cells between Negative and PAG1 group. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and Western blot were used to determine the expression of signaling pathway-related mRNA and proteins respectively. ResultsIn contrast to the normal tissues, PAG1 expression was significantly downregulated in tumor tissues. Treatment with lentivirus transfection, the expression of PAG1 in the OSCC cell lines was increase. Notably, transfected with PAG1-overexpressing lentivirus cells inhibited the proliferation of OSCC cells and promoted OSCC cells apoptosis. RNA-seq revealed that PAG1 mainly modulated the mitophagy and autophagy pathway, and many autophagosomes were observed in the PAG1 group using TEM. Mechanistically, we found that PAG1 upregulated the expression of autophagy related factors through inhibiting PI3K/Akt/mTOR signal pathway activation. ConclusionOverexpression of PAG1 inhibited OSCC progression by activating autophagy, its mechanism might be related to inhibition of PI3K/Akt/mTOR signal pathway phosphorylation.

Knockdown of Secernin 1 inhibit cell invasion and migration by activating the TGF-β/Smad3 pathway in oral squamous cell carcinomas

Secernin-1 (SCRN1) is a regulator of exocytosis in mast cells. Recently, SCRN1 was reported to be correlated with the prognosis of colorectal cancer and gastric cancer, but its functional effects on oral squamous cell carcinoma (OSCC) remain unclear. Our aim was to explore the expression pattern and the migration and invasion effects of the newly identified SCRN1 in OSCC. Western blotting (WB) was performed to measure SCRN1 expression in human OSCC tissue samples and OSCC cell lines. The effects of SCRN1 on OSCC cell proliferation, invasion and migration were analyzed by cell counting kit-8 and Transwell assays. The expression levels of TGF-β, Smad3 and phosphorylated Smad3 (p-Smad3) were measured by WB. The secretion of matrix metalloproteinase (MMP)-2 and MMP-9 was determined by the enzyme-linked immunosorbent assay. The expression of SCRN1 was significantly elevated in OSCC tissues and cell lines. SCRN1 knockdown reduced the expression of TGF-β and p-Smad3 in OSCC cells. TGF-β stimulation promoted proliferation, invasion and migration and enhanced the expression of p-Smad3 and the secretion of MMP9 in SCRN1-knockdown OSCC cell lines. Our study demonstrated that SCRN1 is upregulated in OSCC. Further analyses demonstrated that SCRN1 promotes the proliferation, invasion and migration of OSCC cells via TGF-β/Smad3 signaling.

CEPHAELINE SENSITIZES CISPLATIN AND REDUCES ORAL SQUAMOUS CELL CARCINOMA CANCER STEM CELLS

Objective To evaluate the anticancer properties of Cephaeline on Oral Squamous Cell Carcinoma (OSCC) cell lines, including cancer stem cell (CSC) maintenance. Study Design SCC4, SCC9, and SCC25 OSCC cell lines were used. Cell viability was assessed by MTT. The presence of CSC was evaluated by tumorsphere formation. The histone acetylation (H3K9ac) status was determined by immunofluorescence staining. Results A single administration of Cephaeline disrupted CSC by reducing the tumorsphere. Additionally, cephaeline impacted the histone acetylation status, and a concomitant therapy with CDDP reduces the concentration of CDDP required to achieve IC50 in two cell lines (SCC4 and SCC9). Conclusion Our findings suggest that Cephaeline has anti-cancer properties in OSCC, disrupting the ability of cancer cells to generate tumorspheres. Moreover, this may represent an adjunct therapy to conventional treatments for OSCC. In vivo studies are needed to validate these findings. Funding FAPESP 2016/05710-4 To evaluate the anticancer properties of Cephaeline on Oral Squamous Cell Carcinoma (OSCC) cell lines, including cancer stem cell (CSC) maintenance. SCC4, SCC9, and SCC25 OSCC cell lines were used. Cell viability was assessed by MTT. The presence of CSC was evaluated by tumorsphere formation. The histone acetylation (H3K9ac) status was determined by immunofluorescence staining. A single administration of Cephaeline disrupted CSC by reducing the tumorsphere. Additionally, cephaeline impacted the histone acetylation status, and a concomitant therapy with CDDP reduces the concentration of CDDP required to achieve IC50 in two cell lines (SCC4 and SCC9). Our findings suggest that Cephaeline has anti-cancer properties in OSCC, disrupting the ability of cancer cells to generate tumorspheres. Moreover, this may represent an adjunct therapy to conventional treatments for OSCC. In vivo studies are needed to validate these findings.

Molecular Mechanisms of Inhibitory Effects of Bovine Lactoferrin on Invasion of Oral Squamous Cell Carcinoma

Lactoferrin (LF), an iron-binding glycoprotein, has been reported to have anticancer properties. However, the molecular mechanisms behind its anticancer effects on oral squamous cell carcinoma (OSCC) have not yet been elucidated. Therefore, we aimed to clarify the effects of LF on invasion of OSCC, and its underlying molecular mechanism. OSCC cell lines, HSC2 and HOC313, were treated with bovine LF (bLF). The effects of bLF on cell invasion were examined by a chamber migration assay, wound healing assay, and Boyden chamber method with a basement-membrane-analogue. Expression levels of MMP-1, MMP-3, and AP-1 were examined using RT-PCR, qRT-PCR, and western blotting. Roles of LRP1, a receptor of bLF, on cell invasion were analyzed using siLRP1 knockdown cells. Furthermore, to clarify the importance of LRP1 in invasion, the effects of bLF on tPA-induced invasion of OSCC cells were examined. The invasion assays showed that bLF suppressed invasion of the OSCC cells. Moreover, bLF down-regulated AP-1, and resulted in reductions of MMP-1 and MMP-3. With SiLRP1 knockdown, OSCC cells failed to induce their invasion, and bLF was not able to exert its effects on invasion. Furthermore, bLF remarkably inhibited tPA-induced cell invasion. These findings suggest the importance of LRP1 in bLF-suppressed invasion of OSCC cells via the reduction of AP-1 and MMP production.

Antitumor effects of geraniol on oral cancer

Background: Geraniol has been shown to possess therapeutic or preventive effects against various types of human cancers but not affect normal physiology through regulating cell cycle and apoptosis. However, the biological effects of geraniol on oral squamous cell carcinoma (OSCC) cells are unknown.
 Methods: OSCC cell proliferation was measured by cell-counting kit-8 and colony formation assays. Cell migration was assessed by wound-healing assay. Apoptosis of OSCC cells was detected by TUNEL staining analysis. UM1 xenograft mouse model was used for determining the antitumor effects of geraniol in vivo.
 Results: Geraniol treatment significantly suppressed OSCC cell proliferation and migration in vitro, and tumor growth in vivo in a time- and dose-dependent manner. Further investigation showed that geraniol treatment effectively induced OSCC apoptosis and blocked Phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signaling activation concurrently. We also found that geraniol administration at the dose of 100 and 250 mg/kg did not affect the body weight on tumor-bearing mice, demonstrating the safety of geraniol.
 Conclusion: Geraniol may serve as a promising anticancer drug for the treatment of oral cancer.

Effects of Chrysin on Oral Squamous Cell Carcinoma In Vitro.

Chrysin is a hydroxylated flavonoid derived from "propolis or bee glue," a natural product. Previous research on chrysin's biological functions, including anticancer activity, had been reported. However, chrysin's effect on oral squamous cell carcinoma (OSCC) is still scarce. This article aimed to test the cytotoxicity, antiproliferative, antimigration, anti-invasion, and apoptotic effects of purified chrysin in two OSCC cell lines, HSC4 and SCC25. The malignant phenotype was assessed using cell proliferation, wound healing, and transwell assays. Cell apoptosis was determined using flow cytometry. The positive control was OSCC cells treated with cisplatin, and the negative control was OSCC cells incubated with 0.1% dimethyl sulfoxide. Chrysin at concentrations of 100 and 200 µM could inhibit OSCC cell proliferation, migration, and invasion, as well as enhance cell apoptosis, particularly in the early stages of apoptosis. In OSCC cell lines, chrysin has been demonstrated to be an effective antioncogenic agent. Additional research is required to confirm the results. Chrysin should be suggested as a possible alternative therapeutic application for OSCC.

Anti-Cancer Effect of Bromelain and Its Combination with Cisplatin on HN5 Cell Line (Squamous Cell Carcinoma).

Squamous cell carcinoma (SCC) comprises over 90% of oral malignancies. Cisplatin, as a selective chemotherapy agent to treat SCC, has many side effects despite its high effectiveness. There are some studies on the effects of bromelain derived from pineapple stems on different malignancies. The aim of this study was to investigate the effect of bromelain alone and in combination with Cisplatin on oral squamous cell carcinoma (OSCC) and fibroblast cell lines. In this interventional study, the HN5 cell line of OSCC and fibroblast cell line were treated with different concentrations of bromelain alone and in combination with cisplatin. Cell viability test was performed after 24, 48 and 72 hours using MTT (3-)4,5-dimethylthiazol-2-yl(-2,5 diphenyl tetrazolium bromide) assay. In the final stage, the drug-treated cells underwent flow cytometry to assess apoptosis patterns. Data were analyzed using SPSS 17, ANOVA (for general comparison of groups) and LSD post hoc tests (for comparison two groups). p< 0.05 was considered statistically significant. The findings suggested that although bromelain showed toxic effects on HN5 cancer cells, its combination with Cisplatin resulted in little improvement in its effectiveness. Bromelain alone and in combination with Cisplatin presented cytotoxic effects against fibroblasts, which depended on the dosage and time exposure (p< 0.05). The flow cytometry results did not support the superior effect of the combination of two medications over Cisplatin alone (p> 0.05). According to the findings, although adding bromelain to Cisplatin reduced toxicity on normal tissues, the combination of these two drugs did not increase the anticancer effect of Cisplatin. Thus, bromelain in combination with Cisplatin is not recommended as an adjuvant drug for OSCC.

Apoptotic effect of crude scorpion venom on head and neck squamous cell carcinoma cell line versus normal human epithelial cell line

Aim: The aim of this study was to investigate and compare the apoptotic effect of Leiurus quinquestriatus (LQ) scorpion venom on oral squamous cell carcinoma (OSCC) and normal human epithelial cell lines, in an attempt to introduce a novel selective therapeutic modality for OSCC. Methodology: we explored the effect of LQ scorpion venom on OSCC cell line (HNO-97) compared to normal oral epithelial (OEC) cell line. The cell viability by MTT assay and the expression of PUMA by ELISA were analyzed. Cell cycle analysis was studied for both groups using flow cytometry. Finally, we compared the expression of ROS by ELISA. Results LQ scorpion venom showed selective cytotoxic and apoptotic effect on OSCC cells. In comparison to normal cells, significant dose dependent cell viability reduction, cell cycle arrest and increased expression of apoptotic marker PUMA as well as ROS were observed in cancer cell group in comparison to the control group. Conclusions: LQ crude venom exerts a strong cytotoxic effect against OSCC with minimal effect on normal epithelial cells, thus, providing a selective, effective and less toxic possible chemotherapeutic agent for such a malignancy.

Circ_0058063 contributes to oral squamous cell carcinoma development by sponging miR-145-5p and upregulating SERPINE1.

We aimed to demonstrate the effects circ_0058063 exerted on oral squamous cell carcinoma (OSCC) and its downstream mechanism associated with miR-145-5p and SERPINE1. The relevant contents of miR-145-5p, circ 0058063, and SERPINE1 mRNAs in OSCC were evaluated using quantitative reverse transcription polymerase chain reaction. Functional experiments including CCK-8, Transwell, Western blot, and in vivo experiment were implemented to investigate the biological impacts on OSCC cells. Using dual-luciferase reporter, RIP, and RNA pull-down assays, the direct binding relationship between miR-145-5p, circ 0058063, and SERPINE1, SMAD3, CYR61, and IGF1R mRNAs was verified. In OSCC, Circ 0058063 was significantly overexpressed. Knockdown of circ_0058063 suppressed OSCC cell migration and proliferation, but enhanced cell apoptosis. Functionally and mechanistically, circ_0058063 could specifically bind with miR-145-5p and thus upregulated expression of downstream target SERPINE1, which together contributed to the progression of OSCC. Circ_0058063 could promote the malignant behavior of OSCC by upregulating SERPINE1 through sponging miR-145-5p.

M1 Macrophages Enhance Survival and Invasion of Oral Squamous Cell Carcinoma by Inducing GDF15-Mediated ErbB2 Phosphorylation.

M2 macrophages are generally recognized to have a protumor role, while the effect of M1 macrophages in cancer is controversial. Here, the in vitro and in vivo effects of conditioned medium from M1 macrophages (M1-CM) on oral squamous cell carcinoma (OSCC) cells and a potential mechanism were studied. CCK-8, colony formation, EdU labeling, xenograft growth, and Transwell assays were utilized to observe cell survival/proliferation and migration/invasion, respectively, in OSCC cell lines treated with basic medium (BM) and M1-CM. The ErbB2 phosphorylation inhibitor (CI-1033) and GDF15 knockout cell lines were used to appraise the role of ErbB2 and GDF15 in mediating the effects of M1-CM. Compared with BM, M1-CM significantly enhanced the survival/proliferation of SCC25 cells. The migration/invasion of SCC25 and CAL27 cells also increased. Mechanically, M1-CM promoted GDF15 expression and increased the phosphorylation of ErbB2, AKT, and ErK. CI-1033 significantly declined the M1-CM-induced activation of p-AKT and p-ErK and its protumor effects. M1-CM stimulated enhancement of p-ErbB2 expression was significantly decreased in cells with GDF15 gene knockout vs without. In xenograft, M1-CM pretreatment significantly promoted the carcinogenic potential of OSCC cells. Our results demonstrate that M1 macrophages induce the proliferation, migration, invasion, and xenograft development of OSCC cells. Mechanistically, this protumor effect of M1 macrophages is partly associated with inducing GDF15-mediated ErbB2 phosphorylation.

Transcriptional and H3K27ac related genome profiles in oral squamous cell carcinoma cells treated with metformin.

Objectives: Metformin, a first-line drug that has been used for type 2 diabetes treatment, recently attracts broad attention for its therapeutic effects on diverse human cancers. However, its effect and the underlying mechanisms on oral squamous cell carcinoma (OSCC) are not well known.Materials and Methods: OSCC cells were used to evaluate the effect of metformin on cell proliferation and colony formation in vitro. Tumor formation assay in nude mice was conducted to assess the effect of metformin in vivo. Western blotting and immunohistochemistry stain were performed to investigate the effect of metformin on the expression of acetylation at lysine 27 of histone H3 (H3K27ac) and methylation at lysine 27 of histone H3 (H3K27me3) in vitro and in vivo. RNA-seq and ChIP-seq were performed to explore the genome profile to metformin treatment in OSCC cells.Results: Metformin inhibited OSCC cell proliferation and colony formation in vitro, as well as OSCC growth in vivo. Metformin increased the global H3K27ac modification in vitro. Transcriptome analysis suggested that metformin mainly downregulated pluripotency stem cell pathway, development involved pathways and upregulated cytokine and inflammatory pathways. Additionally, H3K27ac was involved in transcription, DNA repair and replication in metformin-treated OSCC cells.Conclusions: Metformin inhibits OSCC growth concomitant upregulated global level of H3K27ac in vitro. This study provides insights into the molecule and epigenome basis on application of metformin in OSCC treatment, and highlights the underlying mechanisms of reprogrammed cancer regulation and epigenetic histone modification.

PSMC2 knockdown inhibits the progression of oral squamous cell carcinoma by promoting apoptosis via PI3K/Akt pathway

ABSTRACT Proteasome 26S subunit, ATPase 2 (PSMC2) is a recently identified gene which is potentially associated with human carcinogenesis. However, the effects of PSMC2 on oral squamous cell carcinoma (OSCC) is still unclear. Here, we investigated PSMC2 expression in OSCC tissues and explored its effects on the biological behaviors of OSCC cells. PSMC2 expression was evaluated by immunohistochemistry in a tissue microarray containing 60 OSCC tissues and 9 normal tissues. PSMC2 was knocked down through lentivirus infection in OSCC cell lines. MTT, colony formation, flow cytometry, transwell, and scratch assays were performed to detect effects of PSMC2 knockdown on phenotypes of OSCC cells. Human apoptosis antibody array was used to screen potential downstream of PSMC2 in OSCC. Finally, the effects of PSMC2 knockdown on tumor growth were assessed in a tumor xenograft model using BALB/c nude mice. PSMC2 expression was significantly upregulated in OSCC tissues compared with normal tissues and correlated with poor prognosis. PSMC2 knockdown significantly suppressed cell proliferation, migration, but promoted apoptosis of OSCC cells. Additionally, we confirmed that PSMC2 knockdown can increase the expression of pro-apoptotic proteins. Furthermore, we found that PSMC2 knockdown downregulated expression of p100, p-Akt, CDK6, and upregulated of MAPK9. Xenograft experiments revealed that PSMC2 knockdown can suppress OSCC tumor growth and promote apoptosis. This study demonstrated that PSMC2 plays a critical role in OSCC progression through affecting pro-apoptotic protein expression and apoptosis pathways. It indicated that targeting PSMC2 might be a promising strategy for OSCC treatment.

Effects of galectin-1 inhibitor OTX008 on oral squamous cell carcinoma cells in vitro and the role of AP-1 and the MAPK/ERK pathway

ObjectiveTo investigate the in vitro effects of inhibiting galectin-1 using the small-molecule inhibitor OTX008 on oral squamous cell carcinoma (OSCC) cell lines and the role of the MAPK pathway. MethodsOne normal oral keratinocyte (NOK) and three OSCC cell lines were cultured in vitro and the expression of galectin-1 protein by each quantified using ELISA. Cell lines were treated with galectin-1 (50, 100 and 150 ng/mL) or OTX008 (12.5, 25, 50 and 100 μg/mL) and cell viability assayed (n = 3). OSCC cell lines with and without 25 μg/mL OTX008 (n = 3) treatment for 48 h, were analysed using qRT2-PCR with a custom array, to assess relative gene expression. ResultsAll cell lines were found to express galectin-1 protein. Exogenous galectin-1 significantly reduced cell viability in one OSCC cell line over time while the others were only minimally affected. OTX008 treatment reduced cell viability in a dose and time-dependent manner in all cell lines and this was associated with significant regulation of FOS gene expression in the OSCC cell lines. ConclusionOTX008 decreased the viability of OSCC and NOK cells in a dose-dependent manner. The significant regulation of FOS suggests OTX008 causes early induction of the MAPK pathway via the immediate response gene FOS as a subunit of the AP-1 complex.

Inhibitory effects of circulating natural autoantibodies to CD47-derived peptides on OSCC cells.

Natural autoantibodies serve as an important anti-tumorigenic component in the body. This study was thus designed to investigate whether circulating natural IgG autoantibodies against a cluster of differentiation 47 (CD47) could exert inhibitory effects on oral squamous cell carcinoma (OSCC). The expression levels of 13 tumor-targeted genes in three OSCC cell lines were analyzed by qPCR, and CD47 expression in OSCC tissues was also verified with IHC staining. An in-house ELISA was performed to analyze circulating anti-CD47 IgG levels in control subjects, oral benign tumor, and OSCC patients, and to detect anti-CD47 IgG-abundant plasma. Three OSCC cell lines were treated with anti-CD47 IgG-abundant and -deficient plasma, respectively, followed by the analysis of cell proliferation, apoptosis, and invasion/metastasis. The CD47 gene showed the highest expression among 13 genes detected in three OSCC cell lines; its expression was significantly higher in OSCC tissues than adjacent tissues. Plasma anti-CD47 IgG levels showed the differences between control subjects, oral benign tumor, and OSCC patients. Anti-CD47 IgG-abundant plasma could evidently reduce cell viability via suppressing p-AKT expression and inducing cell apoptosis and inhibit the invasion of all three OSCC cell lines. Natural autoantibodies against CD47may be a potential agent for OSCC immunotherapy.