Inhibitive effect of celecoxib on the adhesion and invasion of human tongue squamous carcinoma cells to extracellular matrix via down regulation of MMP-2 expression

Celecoxib and cisplatin dual-loaded microspheres synergistically enhance transarterial chemoembolization effect of hepatocellular carcinoma

Transarterial chemoembolization (TACE) is a first-line treatment for intermediate to advanced-stage liver cancer, with drug-eluting microspheres commonly used as embolic agents. However, currently available drug-eluting microspheres suffer from low drug-loading capacity and limited drug options. In this work, we developed polydopamine-modified polyvinyl alcohol dual-drug-loaded microspheres encapsulating celecoxib and cisplatin (referred to as PCDMS). Physicochemical characterization revealed that the surface of the microspheres displayed increased roughness after polydopamine modification, and celecoxib and cisplatin were successfully loaded onto the microsphere surface. In vitro cell experiments demonstrated that the PCDMS significantly inhibited the proliferation and migration of highly metastatic human liver cancer cells (MHCC-97H) and human liver cancer cells (SMMC-7721). Furthermore, the dual-loaded microspheres exhibited remarkable tumor growth inhibition and reshaped the tumor microenvironment in both subcutaneous H22 liver cancer model in Balb/c mice and intrahepatic VX2 tumor model in New Zealand rabbits, demonstrating a synergistic antitumor effect where 1 + 1>2. This work provides a potential therapeutic approach for the treatment of refractory liver cancer and holds significant translational potential.

Low-dose celecoxib-loaded PCL fibers reverse intervertebral disc degeneration by up-regulating CHSY3 expression

Intervertebral disc degeneration (IDD) has been identified as one of the predominant factors leading to persistent low back pain and disability in middle-aged and elderly people. Dysregulation of Prostaglandin E2 (PGE2) can cause IDD, while low-dose celecoxib can maintain PGE2 at the physiological level and activate the skeletal interoception. Here, as nano fibers have been extensively used in the treatment of IDD, novel polycaprolactone (PCL) nano fibers loaded with low-dose celecoxib were fabricated for IDD treatment. In vitro studies demonstrated that the nano fibers had the ability of releasing low-dose celecoxib slowly and sustainably and maintain PGE2. Meanwhile, in a puncture-induced rabbit IDD model, the nano fibers reversed IDD. Furthermore, low-dose celecoxib released from the nano fibers was firstly proved to promote CHSY3 expression. In a lumbar spine instability-induced mouse IDD model, low-dose celecoxib inhibited IDD in CHSY3^wt mice rather than CHSY3^-/- mice. This model indicated that CHSY3 was indispensable for low-dose celecoxib to alleviate IDD. In conclusion, this study developed a novel low-dose celecoxib-loaded PCL nano fibers to reverse IDD by maintaining PGE2 at the physiological level and promoting CHSY3 expression.

Ferroptosis induction via targeting metabolic alterations in head and neck cancer

Ferroptosis is a newly regulated cell death induced by the accumulation of iron-mediated lipid peroxidation. The alteration of cancer metabolism may contribute to proliferation, metastasis, and treatment resistance in human cancers, implicating the sensitivity to ferroptosis induction. Altered metabolism in cancer cells regulates oxidative stresses and changes metabolism intermediates, contributing to their deregulated growth and proliferation. Cancer metabolic changes toward the elevation of cellular free iron and polyunsaturated fatty acids sensitize cancer cells to lipid peroxidation toxicity tightly linked to ferroptosis. The altered metabolism in cancers can be served as a promising target to reverse cancer therapeutic resistance by ferroptosis induction to selectively kill cancer cells while sparing normal cells. The role of mitochondria and lipid metabolism in inducing ferroptosis in head and neck cancer (HNC) has been elucidated in previous studies. Ferroptosis is receiving attention in cancer research as treating cancers altering cellular metabolism and refractory from conventional therapies. More in-depth studies are needed to develop highly therapeutic drugs and practical methods to induce ferroptosis in diverse cancer cells and tumor microenvironments effectively. Therefore, this review intends to understand the altered metabolism and find new therapeutic possibilities using ferroptosis in HNC.

Sublethal irradiation promotes the metastatic potential of hepatocellular carcinoma cells

Radiotherapy (RT) represents one of the major treatment methods for cancers. However, many studies have observed that in descendant surviving tumor cells, sublethal irradiation can promote metastatic ability, which is closely related to the tumor microenvironment. We therefore investigated the functions and mechanisms of sublethal irradiated liver nonparenchymal cells (NPCs) in hepatocellular carcinoma (HCC). In this study, primary rat NPCs and McA‐RH7777 hepatoma cells were irradiated with 6 Gy X‐ray. Conditioned media (CM) from nonirradiated (SnonR), irradiated (SR), or irradiated plus radiosensitizer celecoxib‐treated (S[R + D]) NPCs were collected and added to sublethal irradiated McA‐RH7777 cells. We showed that CM from sublethal irradiated NPCs significantly promoted the migration and invasion ability of sublethal irradiated McA‐RH7777 cells, which was reversed by celecoxib. The differentially expressed genes in differently treated McA‐RH7777 cells were enriched mostly in the AMP‐activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) signaling pathway. SR increased the migration and invasion ability of HCC cells by inhibiting AMPK/mTOR signaling, which was enhanced by the AMPK inhibitor compound C and blocked by the AMPK activator GSK‐621. Analyses of HCC tissues after neoadjuvant radiotherapy confirmed the effects of radiation on the AMPK/mTOR pathway. Cytokine antibody arrays and further functional investigations showed that matrix metalloproteinase‐8 (MMP‐8) partly mediates the promotion effects of SR on the migration and invasion ability of HCC cells by regulating AMPK/mTOR signaling. In summary, our data indicate that MMP‐8 secreted by irradiated NPCs enhanced the migration and invasion of HCC by regulating AMPK/mTOR signaling, revealing a novel mechanism mediating sublethal irradiation–induced HCC metastasis at the level of the tumor microenvironment.

Progress in targeted therapeutic drugs for oral squamous cell carcinoma

With the rapid development of biomedicine, people have a deeper understanding with the biological characteristics of malignant tumors, and begin to notice that in most tumors, there are over-expression of several molecules such as epidermal growth factor receptor(EGFR), vascular endothelial growth factor (VEGF) and its receptors,mammalian target of rapamycin(mTOR),programmed cell death receptor-1(PD-1),cyclin-dependent kinases(CDKs) and so on, whose levels are closely related to the prognosis of tumors. It has been found that the drugs targeting the above molecules can significantly improve the survival rate of cancer patients, and have the advantages of high selectivity, low toxicity and high therapeutic index. Targeted drugs, as new ones in the field of cancer, have achieved good efficacy in most tumor treatments. Oral cancer is an aggressive malignant tumour that is prone to relapse and metastasis. More than 90% of them are squamous cell carcinoma, and the 5-year survival rate remains at about 50%-60%.The proposing of targeted therapy opens up a new way for the treatment of oral cancer and brings dawn to patients with advanced diseases. Currently,a variety of targeted therapeutic drugs are being tested in various clinical trials in patients with oral squamous cell carcinoma(OSCC)·In this paper, we discuss the research progress of targeted therapeutic drugs in the treatment of OSCC in recent years.

Acupuncture Decreases Matrix Metalloproteinase-2 Activity in Patients with Migraine

Objective

To evaluate the effect of acupuncture on the serum matrix metalloproteinase-2 (MMP-2) level and activity in patients with migraine.

Methods

After baseline testing, eligible patients with migraine according to the criteria of the International Headache Society who volunteered to join the study were included (n=27). The patients received 10 sessions of acupuncture treatment. The points selected were bilateral ST8, ST44, LI4, LI11, LIV3, SP6, GB1, GB14, GB20, GV14, GV20, Yintang, Taiyang and ear Shenmen. Pain was measured using a visual analogue scale (VAS). Short form-36 (SF-36) was used to determine their quality of life. Blood samples were taken before treatment and after the first and last sessions of acupuncture for measurement of MMP-2 concentration and activity.

Results

The mean VAS was 85.5±16.6 before acupuncture and was significantly decreased to 39.8±20.6 after 10 sessions of acupuncture (p<0.0001). There was a significant increase in all SF-36 scores after acupuncture compared with values before treatment (p<0.0001). No significant differences were found in MMP-2 concentrations before treatment and after the first and last sessions (p>0.05). However, there were significant changes in MMP-2 activity (p<0.0001).

Conclusions

The results of this study showed a clinically relevant decrease in MMP-2 activity in patients with migraine treated with acupuncture. The mechanism underlying the effect of acupuncture in alleviating pain may be associated with a decrease in MMP-2 activity.

Role of COX-2/PGE2 Mediated Inflammation in Oral Squamous Cell Carcinoma

A significant amount of research indicates that the cyclooxygenase/prostaglandin E2 (PGE2) pathway of inflammation contributes to the development and progression of a variety of cancers, including squamous cell carcinoma of the oral cavity and oropharynx (OSCC). Although there have been promising results from studies examining the utility of anti-inflammatory drugs in the treatment of OSCC, this strategy has been met with only variable success and these drugs are also associated with toxicities that make them inappropriate for some OSCC patients. Improved inflammation-targeting therapies require continued study of the mechanisms linking inflammation and progression of OSCC. In this review, a synopsis of OSCC biology will be provided, and recent insights into inflammation related mechanisms of OSCC pathobiology will be discussed. The roles of prostaglandin E2 and cluster of differentiation factor 147 (CD147) will be presented, and evidence for their interactions in OSCC will be explored. Through continued investigation into the protumourigenic pathways of OSCC, more treatment modalities targeting inflammation-related pathways can be designed with the hope of slowing tumour progression and improving patient prognosis in patients with this aggressive form of cancer.

The EP4 antagonist, L-161,982, induces apoptosis, cell cycle arrest, and inhibits prostaglandin E2-induced proliferation in oral squamous carcinoma Tca8113 cells

BACKGROUND

Recent studies suggest that cyclooxygenase 2 (COX-2) inhibitors may enhance the toxic effects of anticancer drugs on tumor cells, including oral squamous cell carcinoma (OSCC), but its long-term use can cause side effects such as stomach ulcers and myocardial infarction. Our aim was to investigate proliferative effects of a downstream product of COX-2, prostaglandin E2 (PGE2), in human oral squamous carcinoma cell line Tca8113 and explore the effects of PGE2 receptors, especially EP4 receptor, on the growth of Tca8113 cells.

METHODS

To evaluate the effects of PGE2 and EP receptors on Tca8113 cells, CCK8 assay, Western blotting, cell cycle analysis, and apoptosis assay were performed.

RESULTS

We found that the EP4 receptor agonist, PGE1-OH, could mimick PGE2 rescued the inhibitory effect of celecoxib and induced cell growth via ERK phosphorylation, and the EP4 receptor antagonist, L-161,982, completely blocked PGE2-stimulated ERK phosphorylation and proliferation of Tca8113 cells. Furthermore, L-161,982 may induce apoptosis and block cell cycle progression at s phase by upregulating Bax and p21 protein levels and by downregulating Bcl-2, CDK2, and cyclin A2 protein levels.

CONCLUSIONS

Our results indicate that EP4 receptor mediates PGE2-induced cell proliferation through ERK signaling, and inhibition of EP4 receptor may represent an alternative therapeutic strategy for the prevention and treatment of OSCC.

Increased survival rate by local release of diclofenac in a murine model of recurrent oral carcinoma

Despite aggressive treatment with radiation and combination chemotherapy following tumor resection, the 5-year survival rate for patients with head and neck cancer is at best only 50%. In this study, we examined the therapeutic potential of localized release of diclofenac from electrospun nanofibers generated from poly(D,L-lactide-co-glycolide) polymer. Diclofenac was chosen since anti-inflammatory agents that inhibit cyclooxygenase have shown great potential in their ability to directly inhibit tumor growth as well as suppress inflammation-mediated tumor growth. A mouse resection model of oral carcinoma was developed by establishing tumor growth in the oral cavity by ultrasound-guided injection of 1 million SCC-9 cells in the floor of the mouth. Following resection, mice were allocated into four groups with the following treatment: 1) no treatment, 2) implanted scaffolds without diclofenac, 3) implanted scaffolds loaded with diclofenac, and 4) diclofenac given orally. Small animal ultrasound and magnetic resonance imaging were utilized for longitudinal determination of tumor recurrence. At the end of 7 weeks following tumor resection, 33% of mice with diclofenac-loaded scaffolds had a recurrent tumor, in comparison to 90%–100% of the mice in the other three groups. At this time point, mice with diclofenac-releasing scaffolds showed 89% survival rate, while the other groups showed survival rates of 10%–25%. Immunohistochemical staining of recurrent tumors revealed a near 10-fold decrease in the proliferation marker Ki-67 in the tumors derived from mice with diclofenac-releasing scaffolds. In summary, the local application of diclofenac in an orthotopic mouse tumor resection model of oral cancer reduced tumor recurrence with significant improvement in survival over a 7-week study period following tumor resection. Local drug release of anti-inflammatory agents should be investigated as a therapeutic option in the prevention of tumor recurrence in oral squamous carcinoma.

Non-steroidal anti-inflammatory drugs and the risk of head and neck cancer: A case-control analysis

Non-steroidal anti-inflammatory drugs (NSAIDs) and acetylsalicylic acid (aspirin) have been associated with a reduced risk for certain cancers. We explored the association between use of NSAIDs and the risk of head and neck cancer (HNC). We conducted a case-control analysis in the UK-based Clinical Practice Research Datalink (CPRD) among people below the age of 90 years with incident HNC between 1995 and 2013. Six controls per case were matched on age, sex, calendar time, general practice, and number of years of active history in the CPRD prior to the HNC diagnosis. Other potential confounders including comorbidities and comedication were also evaluated, and we adjusted our final analyses for BMI, smoking and alcohol consumption. Our analyses included 2,745 HNC cases and 16,470 controls. Aspirin or NSAID use overall did not significantly change the HNC risk. However, patients with six or more prescriptions for ibuprofen were at a statistically significantly reduced risk for HNC (adjusted OR 0.59, 95% CI 0.37-0.94). The HNC risk tended to decrease with increasing cumulative exposure to ibuprofen, and to be more pronounced for cancer of the larynx. To conclude, in this large population-based observational study we found a decreased risk for HNC associated with regular use of ibuprofen.

[Interaction of anesthetics and analgesics with tumor cells]

The results of preclinical and clinical studies indicate that the perioperative period is a vulnerable period for cancer progression and metastasis. The risk of cancer cell dissemination is enhanced by the combination of surgical manipulation and perioperative immunosuppression. Whether the oncological outcome of cancer patients can be influenced by the choice of anesthetic techniques is still a matter of debate. This review summarizes the molecular characteristics of cancer and interaction of anesthetic and analgesic drugs with cancer cells.

A COX-2 inhibitor enhances the antitumor effects of chemotherapy and radiotherapy for esophageal squamous cell carcinoma

Cyclooxygenase-2 (COX-2) is a key enzyme of prostaglandin (PG) synthesis that has been demonstrated to be overexpressed in several types of cancers. The function of COX-2 in tumor progression has been recently elucidated. In tumors in which COX-2 is overexpressed, the antitumor effects are suppressed. We examined the effects of celecoxib, a COX-2 inhibitor, in enhancing the antitumor effects of chemotherapy and radiotherapy for esophageal squamous cell carcinoma (ESCC) by reducing the COX-2 activity. We used the human esophageal squamous cell lines TE2 and T.Tn treated with celecoxib and 5-FU/radiation, after which cell viability assays were performed. Changes in the expressions of dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT) mRNA and PGE2 were also measured. In addition, apoptotic changes, and the invasion and migration activity in both the celecoxib and 5-FU treated cells were evaluated. The experiments showed that T.Tn and TE2 proliferation was strongly inhibited by the combination of 5-FU/radiation and the COX-2 inhibitor. Inhibiting the COX-2 activity induced a reduction in PGE2 levels in TE2/T.Tn cells. Following treatment with the COX-2 inhibitor and 5-FU, the OPRT expression was upregulated and the DPD expression was downregulated in the resistant cells. In addition, the combination treatment with the COX-2 inhibitor and 5-FU markedly inhibited both the cell invasion and migration activity. Therefore, COX-2 inhibitors can be useful enhancers of antitumor drugs and radiotherapy for ESCC.

Celecoxib potentially inhibits metastasis of lung cancer promoted by surgery in mice, via suppression of the PGE2-modulated β-catenin pathway

Surgery is the major treatment method for non-small cell lung cancer. It has been reported that plasma PGE2 level is increased following surgery and stress which promotes lung cancer metastasis. In the present study, two animal models were used to confirm the effects of exogenous and endogenous prostaglandin E2 (PGE2) on metastasis of lung cancer cells. We found that both PGE2 level and A549 metastasis were enhanced in mice with unilateral pulmonary resection following tail vein injection of lung cancer A549 cells. Both endogenous PGE2 level and pulmonary metastatic nodules were significantly reduced by celecoxib. A549 metastases were increased in mice after exogenous PGE2 injection. In the animal models, celecoxib inhibited lung cancer cell metastasis induced by exogenous PGE2. Therefore, we focused on the effects of celecoxib on the downstream pathway of PGE2 in vitro and found that celecoxib inhibited PGE2-induced A549 migration and invasion, which were evaluated by wound healing and Transwell experiments. The expression of protein and mRNA of MMP9 and E-cadherin following treatment with PGE2 were suppressed and increased by celecoxib, respectively; however, MMP2 showed no change. A549 cell invasion and up-regulation of the expression of MMP9 and down-regulation of E-cadherin induced by PGE2 were inhibited by FH535, an inhibitor of β-catenin. Deletion of β-catenin by siRNA abrogated celecoxib-induced inhibition of MMP9 up-regulation and E-cadherin down-regulation by treatment of PGE2. Furthermore, we found that the level of β-catenin together with GSK-3β phosphorylation was inhibited by celecoxib. In conclusion, celecoxib inhibits metastasis of A549 cells in the circulation enhanced by PGE2 after surgery by not only inhibiting endogenous PGE2 expression, but also by suppression downstream of PGE2 via the GSK-3β-β-catenin pathway.

Molecular mechanism of the inhibition effect of Celecoxib on corneal collagen degradation in three dimensions

AIM

To clarify the molecular mechanism of Celecoxib on corneal collagen degradation and corneal ulcer.

METHODS

Rabbit corneal fibroblasts were harvested and suspended in serum-free MEM. Type I collagen, DMEM, collagen reconstitution buffer and corneal fibroblast suspension were mixed on ice. The resultant mixture solidify in an incubator, after which test reagents and plasminogen was overlaid and the cultures were returned to the incubator. The supernatants from collagen gel incubations were collected and the amount of hydroxyproline in the hydrolysate was measured. Immunoblot analysis of MMP1, 3 and TIMP1, 2 was performed. MMP2, 9 was detected by the method of Gelatin zymography. Cytotoxicity Assay was measured.

RESULTS

Celecoxib inhibited corneal collagen degradation in a dose and time manner; Celecoxib inhibited the IL-1ß induced increases in proMMP1, 2, 3, 9 and active MMP1, 2, 3, 9 in a concentration-depended manner. Celecoxib can also inhibit the IL-1ß induced increases in the TIMP1, 2.

CONCLUSION

Celecoxib can inhibit corneal collagen degradation induced by IL-1β, this effect is the consequence of the reduction of MMP1, 2, 3, 9 and TIMP1, 2. The results of the present study provide new insight into Celecoxib in corneal ulcer treatment.

Tissue inhibitor of metalloproteinases in oral squamous cell carcinomas - a therapeutic target?

Matrix metalloproteinases (MMPs) are proteases responsible for remodeling the extracellular matrix (ECM) and enabling spreading and metastasis of tumor cells, a common phenomenon in oral squamous cell carcinomas (OSCC). They are strongly blocked by several inhibitors, among which we must highlight, for their specificity and potency, the endogenous tissue inhibitors of metalloproteinases (TIMP-1, -2, -3 and -4). The goal of this paper is to describe the expression of TIMPs in OSCC, determining their relation with clinical, histological and prognostic factors, delving into OSCC regulation mechanisms and discussing the use of exogenous TIMPs to treat this type of tumors. Expression of TIMPs in OSCC is higher in tumors than in normal tissue, which correlates with an increase of metastatic risk and regional lymph node affectation. Although some metalloproteinases inhibitors (MMIs) have shown promising results in the treatment of these tumors, their use in OSCC has not been widely tested; and although some indirect MMIs, like COX-2 inhibitors, flavonoids and endostatin seem to have beneficial effects on the invasive capacity of OSCC through regulation of MMPs and TIMP levels, routine clinical use has not been accepted yet.

The COX-2 inhibitor Celecoxib enhances the sensitivity of KB/VCR oral cancer cell lines to Vincristine by down-regulating P-glycoprotein expression and function

Previous studies have indicated that long-term chemotherapy decreases the sensitivity of oral cancer cells to chemotherapeutics while simultaneously increasing resistance to these drugs. COX-2 inhibitors are known to enhance the toxic action of anti-tumor drugs against cancer cells. Using the MTT method, we investigated the influence of the COX-2 selective inhibitor Celecoxib on the proliferation of KB/VCR oral cancer cell lines and analyzed the effect of Celecoxib on the regulation of P-glycoprotein (P-gp) expression and function. Western blot analysis was employed to detect the expression of P-gp, and flow cytometry was used to evaluate P-gp function by detecting the accumulation of the active P-gp functional fluorescence substrate within KB/VCR cells. The results revealed that a low dose of Celecoxib (10 μmol/L) showed no growth inhibitory effects on KB/VCR cell lines. When the concentration of Celecoxib was greater than or equal to 20 μmol/L, the inhibitory effect on KB/VCR cells was significantly enhanced in a time- and dose-dependent manner. The lower dose of Celecoxib (10 μmol/L) significantly enhanced the toxicity of Vincristine (VCR) against KB/VCR cell lines. After the application of Celecoxib plus VCR (10 μmol/L+1.5μmol/L, respectively) treatment for 24, 48 or 72 h, the growth inhibition rates of KB/KBV cells were 37.82 ± 1.60%, 47.84 ± 1.29% and 54.43 ± 2.35%, respectively, which were significantly higher than the rates in the cells treated only with Celecoxib (10 μmol/L) or VCR (1.5 μmol/L) (all P<0.01). P-gp expression levels in KB/KBV cells treated with Celecoxib plus VCR (10 μmol/L+1.5 μmol/L, respectively) were markedly lower than the levels in control cells and those treated with VCR (1.5 μmol/L) (all P<0.01). In addition, the intensity of Rho123 fluorescence of KB/KBV cells in cells treated with Celecoxib plus VCR (10 μmol/L+1.5 μmol/L, respectively) or Celecoxib alone (10 μmol/L) was significantly higher than the intensity observed in control cells and those treated with VCR alone (1.5 μmol/L) (all P<0.01). The underlying mechanism of these phenomena is likely correlated with the down-regulation of the expression and function of P-gp due to Celecoxib, thereby increasing the amount of VCR accumulated in KB/VCR cells.

Arsenic trioxide inhibits invasion/migration in SGC-7901 cells by activating the reactive oxygen species-dependent cyclooxygenase-2/matrix metalloproteinase-2 pathway

Arsenic trioxide (As(2)O(3)) has been shown to inhibit invasion/migration in cancer cells. However, the underlying mechanism is poorly understood. To identify the role of As(2)O(3) in regulating invasion/migration activity in human gastric cancer SGC-7901 cells, the effects of As(2)O(3) on cell invasion/migration activity, the expression of cyclooxygenase-2 (Cox-2), prostaglandin E2 (PGE2), thromboxane B2 (TXB2), leukotriene B4 (LTB4), and matrix metalloproteinase-2 (MMP-2) and intracellular reactive oxygen species (ROS) were examined. Furthermore, N-acetyl-l-cysteine (NAC, a radical scavenger) and celecoxib (a Cox-2 inhibitor) were used to explore the molecular mechanism. The results demonstrated that As(2)O(3) (1 and 2 μmol/L) inhibited invasion/migration activity in SGC-7901 cells at 24 h and suppressed the expression of Cox-2, PGE2 and MMP-2 (P < 0.05), whereas the same treatment had no significant effect on TXB2 and LTB4 expression. In contrast, intracellular ROS were increased (P < 0.05). Moreover, NAC eliminated the excessive ROS and restored the expression of Cox-2 and MMP-2 and invasion/migration activity in As(2)O(3)-treated cells (P < 0.05). These results suggest that ROS may be a critical factor in regulating the invasion/migration process. Moreover, celecoxib significantly decreased Cox-2, MMP-2 and PGE2 expression and inhibited invasion/migration activity in As(2)O(3)-treated cells (P < 0.05), indicating that As(2)O(3) inhibits invasion/migration by regulating the expression of Cox-2/PGE2/MMP-2. In conclusion, these results suggest that increased ROS play a critical role in inhibiting invasion/migration by suppressing the Cox-2/MMP-2 pathway in As(2)O(3)-treated SGC-7901 cells and regulating intracellular ROS levels may be a promising strategy in gastric cancer therapy.

COX-2 Gene increases tongue cancer cell proliferation and invasion through VEGF-C pathway

COX-2 induces the proliferation and invasion of oral squamous cell carcinoma. In the present study, the role of the COX-2 gene in the tongue cancer cell proliferation and invasion was investigated. A short hairpin RNA (shRNA)method was used to knock down COX-2 gene expression and investigate the relationship between COX-2 and VEGF-C, and the role of the COX-2 gene for proliferation and invasion was also investigated in the tongue cancer cell Tca8113. COX-2 gene overexpressed in tongue cancer cell line. Suppressing the expression of COX-2 by shRNA could decrease cell proliferation comparing with control shRNA. Nevertheless, depressing COX-2 gene expression by shRNA reduced VEGF-C expression on both mRNA and protein levels. VEGF-C gene expression could be regulated by COX-2 gene. Our results suggested that COX-2 played essential roles in the proliferation and metastasis of tongue cancer, and COX-2 could serve as a potential chemotherapy target for tongue cancer.