[Corrigendum] Butein induces cell apoptosis and inhibition of cyclooxygenase­2 expression in A549 lung cancer cells.

Following the publication of the above article, the authors have realized that an error was made in the Acknowledgements section in this paper; this research was not, in fact, supported by a grant from the National Natural Science Foundation of Jilin (Project no. 83657488), as had been stated. The authors regret their oversight in providing this incorrect information in the Acknowledgements section of their paper. They thank the Editor of Molecular Medicine Reports for allowing them the opportunity to publish this corrigendum, and apologize to the readership of the Journal for any inconvenience caused. [the original article was published in Molecular Medicine Reports 9: 763-767, 2014; DOI: 10.3892/mmr.2013.1850].

Molecular mechanism of AQP3 in regulating differentiation and apoptosis of lung cancer stem cells through Wnt/GSK-3ß/ß-Catenin pathway.

PURPOSE: The refractory nature and proneness to recurrence of lung cancer are related to the proliferation and differentiation of lung cancer stem cells (LCSCs). This paper aims to explore the effect of aquaporin-3 (AQP3) on the functions of LCSCs, and its molecular mechanism in regulating the differentiation and apoptosis of LCSCs through the Wnt/glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin pathway. METHODS: The stem cells were selected and the cell lines with low expression of AQP3 were constructed, followed by transcriptome sequencing. LCSCs were transfected with empty lentivirus in the control group and transfected with AQP3 shRNA in the interference group, and the low expression of AQP3 was inhibited using the Wnt pathway inhibitor XAV939 in the interference+inhibitor group. The expressions of AQP3, Wnt/GSK-3ß/ß-catenin pathway genes, stemness genes, differentiation-related markers and apoptosis proteins in LCSCs were detected. RESULTS: In the interference group, the pathway genes were highly expressed. The genes in the interference group were enriched in the Wnt/GSK-3ß/ß-catenin pathway. In the interference group, the expressions of ß-catenin, GSK-3ß and signal transducer and activator of transcription 3 (STAT3) were significantly higher, while the expression of adenomatous polyposis coli (APC) was significantly lower (p<0.05). The expression of Wnt5α had no difference. In the interference group, the expressions of stemness-related genes were obviously higher, while the expression of CDK2 had no difference (p=0.471). The interference group had higher expressions of differentiation markers. CONCLUSION: AQP3 can reduce the differentiation and inhibit the apoptosis of LCSCs through reducing the expressions of Wnt/GSK-3ß/ß-catenin pathway-related genes such as ß-catenin, GSK-3ß and STAT3, thereby affecting the tumor progression.

Molecular mechanism of aquapontin (AQP3) in regulating differentiation and apoptosis of lung cancer stem cells through Wnt/GSK-3ß/ß-Catenin pathway.

PURPOSE: To explore the effect of aquaporin-3 (AQP3) on the functions of lung cancer stem cells (LCSCs), and its molecular mechanism in regulating the differentiation and apoptosis of LCSCs through the Wnt/glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin pathway. METHODS: The stem cells were selected and the cell lines with low expression of AQP3 were constructed, followed by transcriptome sequencing. LCSCs were transfected with empty lentivirus in control group and transfected with AQP3 shRNA in interference group, and the low expression of AQP3 was inhibited using the Wnt pathway inhibitor XAV939 in interference + inhibitor group. The expressions of AQP3, Wnt/GSK-3ß/ß-catenin pathway genes, stemness genes, differentiation-related markers and apoptosis proteins in LCSCs were detected. RESULTS: In interference group, the pathway genes were highly expressed. The genes in interference group were enriched in the Wnt/GSK-3ß/ß-catenin pathway. In interference group, the expressions of ß-catenin, GSK-3ß and signal transducer and activator of transcription 3 (STAT3) were significantly higher, while the expression of adenomatous polyposis coli (APC) was significantly lower (p<0.05). The expression of Wnt5α had no difference. In interference group, the expressions of stemness-related genes were obviously higher, while the expression of CDK2 had no difference (p=0.471). Interference group had higher expressions of differentiation markers. CONCLUSION: In conclusion, AQP3 can reduce the differentiation and inhibit the apoptosis of LCSCs through reducing the expressions of Wnt/GSK-3ß/ß-catenin pathway-related genes such as ß-catenin, GSK-3ß and STAT3, thereby affecting the tumor progression.

[Retracted] Downregulation of NOB1 suppresses the proliferation and tumor growth of non­small cell lung cancer in vitro and in vivo.

Oncol Rep 31: [Related article:] 1271­1276, 2014; DOI: 10.3892/or.2014.2991. The authors wish to retract their article entitled 'Down-regulation of NOB1 suppresses the proliferation and tumor growth of non­small cell lung cancer in vitro and in vivo', published in Oncology Reports 31: 1271­1276, 2014. The authors have identified that the results shown in Fig. 4A did not display a significant level of difference comparing among the groups, which undermines the conclusions stated in the article. In addition, the 'Acknowledgements' section featured an error in terms of the quoted project number. For these reasons, the authors have decided to withdraw this paper from the Journal. All the named authors agree to this retraction. and regret any inconvenience to the readers and to the Editor of Oncology Reports that this retraction will cause.

L-cysteine functionalized straticulate C3N4 for the selective enrichment of glycopeptides.

The facile enrichment of glycopeptides or glycoproteins poses great challenges for glycoproteomic research. In this study, a novel hydrophilic material, named zwitterionic hydrophilic L-cysteine derivatized straticulate-C3N4 composites (LCAC), were synthesized and evaluated for the enrichment of N-glycopeptides. LCAC exhibited good biocompatibility, excellent hydrophilicity and selectivity, by virtue of the large surface of C3N4 and the zwitterionic property offered by cysteine. LCAC demonstrated excellent performance for N-glycopeptide enrichment with the sensitivity of 0.033 fmol/µL, selectivity of 1:100, and high recovery rate (∼85%). The performance of LCAC was demonstrated by the identification of 35 N-glycopeptides from IgG, as well as capturing 1809 human urine N-glycopeptides corresponding to 876 N-glycoproteins. Comparing the LCAC with our developed phenylboronic acid functionalized material showed a certain complementary due to the different binding mechanism. The simple production and enhanced hydrophilic properties make the material a promising choice for glycoproteomics researches.

Upregulation of E-cadherin in bronchoalveolar lavage fluid-derived exosomes in patients with lung cancer.

BACKGROUND: Lung cancer features extremely high rates of morbidity and mortality. Bronchoalveolar lavage fluid (BALF), obtained by bronchoscopy and bronchoalveolar perfusion, can provide information on the cellular components of the lung microenvironment to assist with diagnosis and treatment of lung cancer. METHODS: BALF was performed using a flexible bronchofiberscope. Exosomes were collected by ultracentrifugation. ELISA detected the amount of E-cadherin. Transmission electron microscopic, ELISA and WB were conducted to identify the existence of the exosomes. Transwell and Wound healing assays were used to detect the ability of migration and invasion. RESULTS: We identified the existence of exosomes in BALF. Furthermore, we observed larger amounts of E-cadherin in the BALF obtained from patients with lung cancer than in the control obtained from the healthy side of pneumonia. Exosomes from lung cancer groups promoted the migration and invasion of A549 cancer cells. CONCLUSION: The exosomes from lung cancer BALF promoted the migration and invasion of A549 cancer cells by carrying E-cadherin. E-cadherin on the surface of exosomes may act through a VE-cadherin dependent mechanism and induce lung cancer metastasis.

MicroRNA-141-3p affected proliferation, chemosensitivity, migration and invasion of colorectal cancer cells by targeting EGFR.

Colorectal cancer (CRC) is one of the most often diagnosed cancers globally. MicroRNAs are small RNA molecules that play essential roles in tumorigenesis and progression of CRC. Here we evaluated the effects of miR-141-3p on growth, cetuximab sensitivity, migration and invasion of CRC cells. We found that miR-141-3p negatively regulated the proliferation, migration and invasion in CRC cells. In addition, miR-141-3p enhanced the cetuximab sensitivity of CRC cells by EGFR suppression. Moreover, miR-141-3p improved cetuximab-induced apoptosis in CRC cells. Furthermore, miR-141-3p altered the expression of E-cadherin, N-cadherin, snail and Vimentin, indicating miR-141-3p might play a role on epithelial to mesenchymal transition (EMT). Luciferase reporter assay showed that EGFR was the direct binding site of miR-141-3p and the expression levels of p-EGFR, Raf-1, pAKT and p-ERK1/2 were regulated by miR-141-3p. After down-regulation of EGFR by siRNA in CRC cells, the effects of miR-141-3p on proliferation, migration and invasion were reversed. miR-141-3p played important roles in CRC growth and response to cetuximab treatment, and might function as a potential biomarker to predict cetuximab response.

LncRNA PLAC 2 downregulated miR-21 in non-small cell lung cancer and predicted survival.

BACKGROUND: LncRNA PLAC2 has been characterized as a tumor suppressive lncRNA in glioma. We investigated the role of PLAC2 in non-small cell lung cancer (NSCLC). METHODS: A total of 187 NSCLC patients were admitted by The First Hospital of Jilin University from December 2010 to December 2014. All the patients were diagnosed by histopathological approaches. Transient cell transfections, RT-qPCR, invasion, and migration ability measurement, were applied for the experiments. RESULTS: PLAC2 was down-regulated, while miR-21 was up-regulated in NSCLC tissues compared to non-cancer tissues. Low PLAC2 levels in NSCLC tissues were associated with poor survival of NSCLC patients. PLAC2 and miR-21 were inversely correlated, and PLAC 2 over-expression in NSCLC cells resulted in the down-regulation of miR-21. However, miR-21 over-expression did not significantly affect PLAC2 expression. In addition, PLAC2 over-expression resulted in decreased migration and invasion rates of NSCLC cells. MiR-21 over-expression played the opposite role and attenuated the effects of PLAC2 over-expression. CONCLUSIONS: In conclusion, lncRNA PLAC2 down-regulated miR-21 in NSCLC and inhibited cancer cell migration and invasion.

Vitamin D3-vitamin D receptor axis suppresses pulmonary emphysema by maintaining alveolar macrophage homeostasis and function.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by emphysema and/or obstructive bronchiolitis. Deficiency in vitamin D3 (VD3), which regulates gene expression through binding to vitamin D receptor (VDR), is associated with high risks of COPD susceptibility. Alveolar macrophages (AM), which are generated during early ontogeny and maintained in alveoli by self-renewal in response to cytokine GM-CSF, are positively correlated with severity of emphysema. However, whether and how VD3, VDR and AM interact to contribute to COPD pathogenesis at the molecular and cellular levels are largely unknown. METHODS: We used systems biology approaches to analyze gene expression in mouse macrophages from different tissues to identify key transcription factors (TF) for AM and infer COPD disease genes. We used RNA-seq and ChIP-seq to identify genes that are regulated by VD3 in AM. We used VDR-deficient (Vdr-/-) mice to investigate the role of VD3-VDR axis in the pathogenesis of COPD and characterized the transcriptional and functional alterations of Vdr-/- AM. FINDINGS: We find that VDR is a key TF for AM and a COPD disease gene. VDR is highly expressed in AM and in response to VD3 inhibits GM-CSF-induced AM proliferation. In Vdr-/- AM, genes involved in proliferation and immune response are upregulated. Consistently, Vdr-/- mice progressively accumulate AM and concomitantly develop emphysema without apparent infiltration of immune cells into the lung tissue. Intratracheal transfer of Vdr-/- AM into wildtype mice readily induces emphysema. The production of reactive oxygen species at basal level and in response to heme or lipopolysaccharide is elevated in Vdr-/- AM and suppressed by VD3 in wildtype AM. INTERPRETATION: These results show that the VD3-VDR axis is critical to counteract GM-CSF-induced AM proliferation and defect in this regulation leads to altered AM homeostasis and function. Our findings identify that VD3 deficiency contributes to emphysema by altering AM function without contributing to bronchiolitis. Our findings also suggest possibilities of modulating the VD3-VDR axis for inhibiting emphysema in COPD patients.

Overexpression of the long non-coding RNA Oprm1 alleviates apoptosis from cerebral ischemia-reperfusion injury through the Oprm1/miR-155/GATA3 axis.

Numerous differentially expressed long non-coding RNAs (lncRNAs) have been identified in cerebral ischemia-reperfusion (I/R) injury using RNA-Seq analysis. However, little is known about whether and how lncRNAs are involved in cerebral I/R injury. In this study, we investigated the function of the lncRNA Oprm1 in cerebral I/R injury and explored the underlying mechanism. An oxygen-glucose deprivation model in N2a cells was utilized to mimic cerebral I/R injury in vitro. Trypan blue staining, terminal deoxytransferase-mediated dUTP-biotin nick end labelling and caspase-3 were measured to evaluate apoptosis. Middle cerebral artery occlusion was performed in mice to evaluate the function of lncRNA Oprm1 in vivo. Real-time PCR and western blotting were used to measure the expression levels of lncRNA Opmr1, caspase-3, miR-155, GATA binding protein 3 (GATA3) and nuclear factor (NF)-κB. lncRNA Oprm1 was mainly located in the cytoplasm. Overexpression of lncRNA Oprm1 alleviated the apoptosis induced by oxygen-glucose deprivation and significantly reduced cleaved caspase-3 levels. Infarct size was distinctly decreased in the lncRNA Oprm1-overexpression group. The neurological score was also improved. Our findings showed that the lncRNA Oprm1/miR-155/GATA3 axis plays an important role in cerebral I/R injury. lncRNA Oprm1 may attenuate cerebral injury through the NF-κB pathway. lncRNA Oprm1 may serve as a potential target for new therapeutic interventions in patients with ischemic stroke.

Long noncoding RNA CRNDE promotes non-small cell lung cancer progression via sponging microRNA-338-3p.

BACKGROUND: The long noncoding RNA colorectal neoplasia differentially expressed (CRNDE) was reported to be involved in the initiation and development of multiple cancers. However, the detailed biological role of CRNDE in non-small cell lung cancer (NSCLC) remains largely unclear. Herein, we aimed to explore the biological function and underlying molecular mechanism of CRNDE in NSCLC. MATERIALS AND METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression of CRNDE in NSCLC tissues and cell lines. Cell counting kit-8 (CCK-8), colony formation, flow cytometry, wound-healing, and transwell invasion assays were applied to detect cell proliferation, colony formation, cycle arrest progression, migration and invasion, respectively. Novel targets of CRNDE were selected with bioinformatics software and were confirmed using luciferase reporter and RNA immunoprecipitation assays. To detect the role of CRNDE in vivo tumorigenesis, tumor xenografts were created. RESULTS: CRNDE expression is remarkably upregulated in NSCLC tissues and cell lines. Upregulated CRNDE expression was positively associated with advanced tumor-node-metastasis (TNM) stage, lymph node metastasis and poor overall survival of patients with NSCLC. Function assays demonstrated that knockdown of CRNDE significantly inhibited NSCLC cell proliferation, colony formation, migration and invasionin vitro, and decreased the xenograft tumor volume and weight in vitro. We uncovered that miR-338-3p is a downstream target of CRNDE and that miR-338-3p inhibition partially reversed the CRNDE depletion-mediated inhibitory effect on cell proliferation, colony formation, migration and invasion in NSCLC cells. CONCLUSION: These findings indicated that CRNDE functions as an oncogene that exerts important regulatory roles in NSCLC progression via sponging miR-338-3p.

Inhibition of C-X-C Motif Chemokine 10 (CXCL10) Protects Mice from Cigarette Smoke-Induced Chronic Obstructive Pulmonary Disease.

BACKGROUND Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by long-term breathing problems and poor airflow. COPD can progress to persistent decline of pulmonary function. This study explored the effect of CXCL10 on COPD induced by cigarette smoke (CS) and its underlying mechanism. MATERIAL AND METHODS Wild-type (WT) mice were randomly assigned into 3 groups: the control group, the CS group, and the intervention group. Mice in the CS group were exposed to CS and mice in the CXCL10 group were exposed to CS and CXCL10 neutralizing antibody. At 24 h after the last CS exposure, body weight and lung functions of each mouse were recorded. Mice were then anesthetized for collecting bronchoalveolar lavage fluid (BALF) and lung tissues. Levels of interleukin-6 (IL-6), keratinocyte chemotactic factor (KC), and monocyte chemoattractant protein-1 (MCP-1) in supernatant and lung homogenate were detected by ELISA and real-time PCR (RT-PCR), respectively. For in vitro experiments, human bronchial epithelial cells 16HBE were stimulated with different concentrations of cigarette smoke extract (CSE) and CXCL10. Cell viability and levels of inflammatory cytokines in the cell supernatant were detected by Cell Counting Kit-8 (CCK-8) and ELISA assay, respectively. RESULTS Our data showed significant weight loss and reduction of lung functions in mice in the CS group compared with those in the control group and intervention group. Increased levels of IL-6, KC, and MCP-1 in BALF and lung homogenate were observed in mice in the model group compared to those in the control group and intervention group. In vitro experiments also confirmed that CXCL10-neutralizing antibody can inhibit CSE-induced cell necrosis and activation of inflammatory cytokines. CONCLUSIONS Inhibited CXCL10 protects against COPD progression by decreasing secretion of inflammatory factors, which provides a new direction for the clinical prevention and treatment of COPD.

Long noncoding RNA HOXD-AS1 promotes non-small cell lung cancer migration and invasion through regulating miR-133b/MMP9 axis.

HOXD antisense growth associated long noncoding RNA (HOXD-AS1) was reported to be dysregulated and exert crucial roles in tumorigenesis and progression of multiple malignancies. However, the role and mechanism of action of HOXD-AS1 in the carcinogenesis and progression of non-small lung cell cancers (NSCLC) remains largely unknown. HOXD-AS1, miR-133a and Matrix metallopeptidase 9 (MMP-9) mRNA expression were detected by quantitative real-time polymerase chain reaction assays in NSCLC tissues and cell lines. Cell counting kit-8, wound healing and transwell invasion assays were performed to evaluate cell proliferation, migration and invasion abilities, respectively. Luciferase assays were used to investigate binding seeds between miR-133b and HOXD-AS1. Western blot assay were performed to detect protein expression. Here higher expression of HOXD-AS1 was found in NSCLC tumor tissues compared with normal lung tissues, and was associated with lymph node metastasis, high tumor node metastasis (TNM) stage, and poor overall survival rate of patients with NSCLC. Knockdown of HOXD-AS1 significantly inhibited proliferation, migration and invasion of NSCLC cells. Additionally, we found that miR-133b was a direct downstream target of HOXD-AS1 in NSCLC. miR-133b inhibition reverse the inhibitory effect of HOXD-AS1 knockdown on the proliferation, migration, and invasion of NSCLC cells. Furthermore, HOXD-AS1 positively regulated the expression of MMP-9 (a target of miR-133b) in NSCLC cells. These results suggest that HOXD-AS1 might be a potential prognostic biomarker and a novel therapeutic target for treating NSCLC.

A Novel Long Noncoding RNA (lncRNA), LL22NC03-N64E9.1, Promotes the Proliferation of Lung Cancer Cells and is a Potential Prognostic Molecular Biomarker for Lung Cancer.

BACKGROUND The aim of this study was to investigate the expression of a novel long noncoding RNA (lncRNA), LL22NC03-N64E9.1, and its effect on the phenotype of lung cancer cells and tissues using The Cancer Genome Atlas (TCGA) RNA sequencing data and other publicly available profiling data. MATERIAL AND METHODS The lung cancer dataset GSE30219 was downloaded from the Gene Expression Omnibus (GEO) repository. Differentially expressed lncRNA, LL22NC03-N64E9.1, in 48 lung cancer tissue samples and adjacent normal lung tissues, normal lung cell lines BEAS-2B and A549, and lung cancer cell lines, H1703, and H292, were detected by quantitative reverse transcription polymerase chain reaction (PCR) (qRT-PCR). Interference efficiency was performed using small interfering RNA (siRNA). Tumor levels of lncRNA, LL22NC03-N64E9.1, and clinicopathological parameters were statistically analyzed. RESULTS Analysis of the GSE30219 test cohort showed that lncRNA, LL22NC03-N64E9.1 expression was significantly increased in lung cancer. In clinical tissue samples, the level of LL22NC03-N64E9.1 in patients with lung cancer was significantly increased compared with adjacent normal lung tissues (P<0.001). The level of LL22NC03-N64E9.1 in patients with lung cancer was significantly correlated with tumor size and TNM stage (P<0.05), but not with age, sex and the presence of lymph node metastasis (P>0.05). In the H292 cells, following knockdown of LL22NC03-N64E9.1, cell proliferation and cloning were reduced. CONCLUSIONS Expression of lncRNA, LL22NC03-N64E9.1, promoted proliferation of lung cancer cells in vitro, was highly expressed in lung cancer tissues and was associated with increased overall survival (OS), tumor size, and tumor stage in patients with lung cancer.

Erratum to: Suppression of Spry4 enhances cancer stem cell properties of human MDA-MB-231 breast carcinoma cells.

[This corrects the article DOI: 10.1186/s12935-016-0292-7.].

Suppression of Spry4 enhances cancer stem cell properties of human MDA-MB-231 breast carcinoma cells.

BACKGROUND: Cancer stem cells contribute to tumor initiation, heterogeneity, and recurrence, and are critical targets in cancer therapy. Sprouty4 (Spry4) is a potent inhibitor of signal transduction pathways elicited by receptor tyrosine kinases, and has roles in regulating cell proliferation, migration and differentiation. Spry4 has been implicated as a tumor suppressor and in modulating embryonic stem cells. OBJECTIVES: The purpose of this research was to test the novel idea that Spry4 regulates cancer stem cell properties in breast cancer. METHODS: Loss-of function of Spry4 in human MDA-MB-231 cell was used to test our hypothesis. Spry4 knockdown or control cell lines were generated using lentiviral delivery of human Spry4 or non-targeting control shRNAs, and then selected with 2 µg/ml puromycin. Cell growth and migratory abilities were determined using growth curve and cell cycle flow cytometry analyses and scratch assays, respectively. Xenograft tumor model was used to determine the tumorigenic activity and metastasis in vivo. Cancer stem cell related markers were evaluated using immunoblotting assays and fluorescence-activated cell sorting. Cancer stem cell phenotype was evaluated using in vitro mammosphere formation and drug sensitivity tests, and in vivo limiting dilution tumor formation assay. RESULTS: Two out of three tested human Spry4 shRNAs significantly suppressed the expression of endogenous Spry4 in MDA-MB-231 cells. Suppressing Spry4 expression increased MDA-MB-231 cell proliferation and migration. Suppressing Spry4 increased ß3-integrin expression, and CD133(+)CD44(+) subpopulation. Suppressing Spry4 increased mammosphere formation, while decreasing the sensitivity of MDA-MB-231 cells to Paclitaxel treatment. Finally, suppressing Spry4 increased the potency of MDA-MB-231 cell tumor initiation, a feature attributed to cancer stem cells. CONCLUSIONS: Our findings provide novel evidence that endogenous Spry4 may have tumor suppressive activity in breast cancer by suppressing cancer stem cell properties in addition to negative effects on tumor cell proliferation and migration.

Suppression of Spry1 inhibits triple-negative breast cancer malignancy by decreasing EGF/EGFR mediated mesenchymal phenotype.

Sprouty (Spry) proteins have been implicated in cancer progression, but their role in triple-negative breast cancer (TNBC), a subtype of lethal and aggressive breast cancer, is unknown. Here, we reported that Spry1 is significantly expressed in TNBC specimen and MDA-MB-231 cells. To understand Spry1 regulation of signaling events controlling breast cancer phenotype, we used lentiviral delivery of human Spry1 shRNAs to suppress Spry1 expression in MDA-MB-231, an established TNBC cell line. Spry1 knockdown MDA-MB-231 cells displayed an epithelial phenotype with increased membrane E-cadherin expression. Knockdown of Spry1 impaired MDA-MB-231 cell migration, Matrigel invasion, and anchorage-dependent and -independent growth. Tumor xenografts originating from Spry1 knockdown MDA-MB-231 cells grew slower, had increased E-cadherin expression, and yielded fewer lung metastases compared to control. Furthermore, suppressing Spry1 in MDA-MB-231 cells impaired the induction of Snail and Slug expression by EGF, and this effect was associated with increased EGFR degradation and decreased EGFR/Grb2/Shp2/Gab1 signaling complex formation. The same phenotype was also observed in the TNBC cell line MDA-MB-157. Together, our results show that unlike in some tumors, where Spry may mediate tumor suppression, Spry1 plays a selective role in at least a subset of TNBC to promote the malignant phenotype via enhancing EGF-mediated mesenchymal phenotype.

Combined cetuximab and celecoxib treatment exhibits a synergistic anticancer effect on human oral squamous cell carcinoma in vitro and in vivo.

The aim of the present study was to evaluate the potency of epidermal growth factor receptor (EGFR) pathway inhibition achieved by combining cetuximab (CET), an anti-EGFR monoclonal antibody, and celecoxib (CXB), a cyclooxygenase-2 (COX-2) inhibitor, in oral squamous cell carcinoma (OSCC) in vitro and in vivo. The OSCC cell line, HSC3, was treated with CET (0-400 µg/ml), CXB (0-40 µM), or a combination of both at a range of concentrations. Cell proliferation, apoptosis, migration and invasion were determined to assess the anticancer effects in vitro. The in vivo effects of CET and CXB on tumor cell growth were examined using an OSCC xenograft nude mouse model. In addition, downstream protein expression levels of EGFR, p-EGFR, PI3K, p-PI3K, AKT and p-Akt were evaluated by western blot analysis. It was found that the combination of low concentrations of CET and CXB significantly suppressed the proliferation, migration and invasion of the HSC3 tumor cells and decreased PEG2 production and VEGF expression in vitro, and inhibited tumor growth in vivo compared to the action of either agent alone. The results also showed that this combination significantly induced apoptosis and increased caspase-3 and caspase-8 activity compared to the action of either agent alone (P<0.01). Furthermore, the combination treatment significantly reduced the expression of p-EGFR, p-PI3K and p-Akt in the HSC3 cell line, which may contribute to the inhibition of tumor growth. Taken together, our findings revealed that the additive combination of CET and CXB is a potential drug candidate for the treatment of OSCC.