Cisplatin combined with metformin inhibits migration and invasion of human nasopharyngeal carcinoma cells by regulating E-cadherin and MMP-9

Combined regimens of cisplatin and metformin in cancer therapy: A systematic review and meta-analysis

INTRODUCTION

Cancer cell resistance to chemotherapy agents is a challenging issue in treating patients with cancer. Findings suggest that a combination of drugs may have synergistic or additive effects. in the present study, we systematically reviewed the combined regimens of metformin with cisplatin in various treating cancers.

METHODS

A comprehensive systematic search was performed in PubMed, Scopus, Embase, and other relevant databases with the following keyword "metformin", "cisplatin", "combination", "using all their equivalents and similar terms. Pooled odds ratio (OR) and 95% confidence intervals of cell viability and tumor volume as primary outcomes were calculated using Der-Simonian and Laird method while random effects meta-analysis was used, taking into account clinical and statistical heterogeneity.

RESULTS

Overall, 44 studies were retrieved, Findings of the present meta-analysis showed that combined regimens of metformin plus cisplatin was significantly associated with decreased odds of tumor volume and cell viability for all cancers compared with cisplatin alone (pooled OR: 0.40; 95% CI: 0.27, 0.58) and (pooled OR: 0.49; 95% CI: 0.42, 0.58) respectively. The result was same for cell viability in lung cancer (pooled OR: 0.59; 95% CI: 0.49, 0.70). The tumor size reduction and the response rate were evident in the animal xenografts model.

CONCLUSION

Findings indicated that combining metformin with cisplatin is a practical therapeutic approach to increase treatment efficacy in the case of cell viability and tumor volume and minimize side effects. A combination of metformin with cisplatin could enhance treatment efficacy through synergistic inhibitory effects on the growth of cancer cells.

Robust Quantification of Regional Patterns of Migration in Three-Dimensional Cell Culture Models

Purpose

Wound healing assays is a common two-dimensional migration model, with the spheroid assay three-dimensional migration model recently emerging as being more representative of in vivo migration behaviours. These models provide insight into the overall migration of cells in response to various factors such as biological, chemotactic and molecular agents. However, currently available analysis techniques for these assays fall short on providing quantifiable means to measure regional migration patterns, which is essential to allow a more robust assessment of drug treatments on cell migration in a chemotactic fashion. Therefore, this study aims to develop a finite element (FE) based pipeline that can objectively quantify regional migration patterns of cells.

Methods

We have developed a novel FE based approach that is able to accurately measure changes in overall migration areas of 3D Glioblastoma Multiforme (GBM) spheroids that we generated using the primary cell lines from patients undergoing tumour resection surgery. We live-imaged the migration patterns of GBM spheroids and analysed them, first with the standard ImageJ method. We then performed the same analysis with the proposed FE method.

Results

When compared to the standard ImageJ method, our proposed method was able to measure the changes in a more quantitative and accurate manner. Furthermore, our regional migration analysis provided means to analyse the migration pattern seen in the phantom data and our experimental results.

Conclusion

Our FE based method will be a a robust tool for analysing cell migration patterns of GBM and other migrating cells in various diseases and degenerations.

AngIV-Analog Dihexa Rescues Cognitive Impairment and Recovers Memory in the APP/PS1 Mouse via the PI3K/AKT Signaling Pathway

The renin-angiotensin system (RAS) is a paracrine RAS within the central nervous system (CNS) and is closely related to Alzheimer’s disease (AD). The endogenous hexapeptide angiotensin IV (Ang IV), an important component of the brain RAS, was found to rescue cognitive impairment and recover memory in previous studies. In our study, we used different doses of Dihexa, which can be orally administered and cross the BBB in APP/PS1 mice. We found that the amount of AngIV in mouse tissue increased after the administration of Dihexa compared to that in the WT group. Meanwhile, Dihexa restored spatial learning and cognitive functions in the Morris water maze test. Dihexa increased the neuronal cells and the expression of SYP protein in APP/PS1 mice in Nissl staining. Furthermore, Dihexa decreased the activation of astrocytes and microglia, markedly reduced levels of the pro-inflammatory cytokines IL-1β and TNF-α and increased the levels of the anti-inflammatory cytokine IL-10. Dihexa activated the PI3K/AKT signaling pathway, while PI3K inhibitor wortmannin significantly reversed the anti-inflammatory and anti-apoptotic effects of APP/PS1 mice. These findings highlight the brain AngIV/PI3K/AKT axis as a potential target for the treatment of AD.

Effects of different combined regimens of cisplatin, metformin, and quercetin on nasopharyngeal carcinoma cells and subcutaneous xenografts

Cisplatin, metformin, and quercetin are all reliable anticancer drugs. However, it is unclear how effective their different combination regimens are on the growth of nasopharyngeal carcinoma cell line Sune-1 and subcutaneous xenograft in nude mice. This study evaluated the effects of single-drug, two-drug, and three-drug simultaneous or sequential combined application of these drugs on the growth of Sune-1 cells and subcutaneous xenograft tumors in nude mice. The results showed that the different combination regimens of cisplatin, metformin and quercetin all had significant inhibitory effects on the proliferation of Sune-1 cells and the growth of subcutaneous xenografts in nude mice (P < 0.01), and the inhibition rate of the three drugs simultaneous combined application was significant Higher than the two-drug combination or single-drug application (P < 0.05), the contribution level of each drug in the three-drug combination application from high to low were cisplatin > metformin > quercetin. In summary, our results indicate that the simultaneous combination of cisplatin, metformin, and quercetin may synergistically inhibit the growth of Sune-1 cells and subcutaneous xenografts in nude mice through their different anticancer mechanisms, which may be clinically refractory and provide reference for chemotherapy of patients with recurrent nasopharyngeal carcinoma.

SATB1 Knockdown Inhibits Proliferation and Invasion and Decreases Chemoradiation Resistance in Nasopharyngeal Carcinoma Cells by Reversing EMT and Suppressing MMP-9

Background: Special AT-rich sequence binding protein 1 (SATB1) is a chromatin organizer and transcriptional regulator which regulate numerous cellular processes through effects on multiple gene expression. SATB1 is associated with drug resistance in several cancers. Whether SATB1 involves radiation resistance in nasopharyngeal carcinoma (NPC) and underlying mechanism of SATB1 to participate in chemoradiotherapy resistance in NPC have not been elaborated. Methods: Chemoradioresistant NPC cell lines 5-8F/DDP (cisplatin) and 5-8F/R (radiation) were developed from 5-8F cell line. The expressions of SATB1, MMP-9 and EMT markers (Vimentin and E-cadherin) in these cell lines were examined by reverse transcription-quantitative (RT-q) PCR and western blot (WB) analysis. Cell viabilities of 5-8F/DDP treated with various concentrations of DDP and 5-8F/R irradiated with various doses of X-ray at the indicated time were investigated by MTT test. SATB1 was silenced in 5-8F/DDP and 5-8F/R cells by short hairpin RNA, and then the expressions of SATB1, MMP-9, Vimentin and E-cadherin were evaluated by RT-qPCR and WB analysis; the abilities of cell proliferation and invasion were assessed using MTT and transwell assays, respectively. Drug and radiation resistance assays were performed after SATB1 knockdown and cell viability was detected by MTT method. Results: SATB1, MMP-9 and Vimentin were markedly upregulated in 5-8F/DDP and 5-8F/R cells compared with 5-8F cell, whereas E-cadherin was obviously downregulated. 5-8F/DDP and 5-8F/R cells displayed drug and radiation resistance to DDP or X-irradiation, respectively, while DDP or X-irradiation inhibited 5-8F cell viability in a time- and dose-dependent manner. Subsequently, knockdown of SATB1 resulted in decreased MMP-9 and Vimentin expression and increased E-cadherin expression in 5-8F/DDP and 5-8F/R. Furthermore, silencing of SATB1 suppressed proliferative and invasive abilities of 5-8F/DDP and 5-8F/R cells. Additionally, SATB1 knockdown reduced drug resistance of 5-8F/DDP cell to DDP and decreased radiation resistance of 5-8F/R cell to X-ray. Conclusion: These results suggest that high expression of SATB1 plays an important role in the malignant behavior of NPC and leads to X-radiation and drug resistance in NPC through promoting EMT process and enhancing MMP-9 expression. SATB1 may be a promising therapeutic target for aggressive and chemoradiation resistant NPC.

The Chemosensitizing Role of Metformin in Anti-Cancer Therapy

Chemoresistance, which leads to the failure of chemotherapy and further tumor recurrence, presents the largest hurdle for the success of anti-cancer therapy. In recent years, metformin, a widely used first-line antidiabetic drug, has attracted increasing attention for its anti-cancer effects. A growing body of evidence indicates that metformin can sensitize tumor responses to different chemotherapeutic drugs, such as hormone modulating drugs, anti-metabolite drugs, antibiotics, and DNA-damaging drugs via selective targeting of Cancer Stem Cells (CSCs), improving the hypoxic microenvironment, and by suppressing tumor metastasis and inflammation. In addition, metformin may regulate metabolic programming, induce apoptosis, reverse Epithelial to Mesenchymal Transition (EMT), and Multidrug Resistance (MDR). In this review, we summarize the chemosensitization effects of metformin and focus primarily on its molecular mechanisms in enhancing the sensitivity of multiple chemotherapeutic drugs, through targeting of mTOR, ERK/P70S6K, NF-κB/HIF-1 α, and Mitogen- Activated Protein Kinase (MAPK) signaling pathways, as well as by down-regulating the expression of CSC genes and Pyruvate Kinase isoenzyme M2 (PKM2). Through a comprehensive understanding of the molecular mechanisms of chemosensitization provided in this review, the rationale for the use of metformin in clinical combination medications can be more systematically and thoroughly explored for wider adoption against numerous cancer types.>.

Anticancer Properties of Platinum Nanoparticles and Retinoic Acid: Combination Therapy for the Treatment of Human Neuroblastoma Cancer

Neuroblastoma is the most common extracranial solid tumor in childhood. The different treatments available for neuroblastoma are challenged by high rates of resistance, recurrence, and progression, most notably in advanced cases and highly malignant tumors. Therefore, the development of more targeted therapies, which are biocompatible and without undesired side effects, is highly desirable. The mechanisms of actions of platinum nanoparticles (PtNPs) and retinoic acid (RA) in neuroblastoma have remained unclear. In this study, the anticancer effects of PtNPs and RA on neuroblastoma were assessed. We demonstrated that treatment of SH-SY5Y cells with the combination of PtNPs and RA resulted in improved anticancer effects. The anticancer effects of the two compounds were mediated by cytotoxicity, oxidative stress (OS), mitochondrial dysfunction, endoplasmic reticulum stress (ERS), and apoptosis-associated networks. Cytotoxicity was confirmed by leakage of lactate dehydrogenase (LDH) and intracellular protease, and oxidative stress increased the level of reactive oxygen species (ROS), 4-hydroxynonenal (HNE), malondialdehyde (MDA), and nitric oxide (NO), and protein carbonyl content (PCC). The combination of PtNPs and RA caused mitochondrial dysfunction by decreasing the mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content, number of mitochondria, and expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Endoplasmic reticulum-mediated stress and apoptosis were confirmed by upregulation of protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6), activating transcription factor 4 (ATF4), p53, Bax, and caspase-3 and down regulation of B-cell lymphoma 2 (BCl-2). PtNPs and RA induced apoptosis, and oxidative DNA damage was evident by the accumulation of 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-hydroxyguanosine (8-OHG). Finally, PtNPs and RA increased the differentiation and expression of differentiation markers. Differentiated SH-SY5Y cells pre-treated with PtNPs or RA or the combination of both were more sensitive to the cytotoxic effect of cisplatin than undifferentiated cells. To our knowledge, this is the first study to demonstrate the effect of the combination of PtNPs and RA in neuroblastoma cells. PtNPs may be a potential preconditioning or adjuvant compound in chemotherapeutic treatment. The results of this study provide a rationale for clinical evaluation of the combination of PtNPs and RA for the treatment of children suffering from high-risk neuroblastoma.

A New and Integral Approach to the Etiopathogenesis and Treatment of Breast Cancer Based upon Its Hydrogen Ion Dynamics

Despite all efforts, the treatment of breast cancer (BC) cannot be considered to be a success story. The advances in surgery, chemotherapy and radiotherapy have not been sufficient at all. Indeed, the accumulated experience clearly indicates that new perspectives and non-main stream approaches are needed to better characterize the etiopathogenesis and treatment of this disease. This contribution deals with how the new pH-centric anticancer paradigm plays a fundamental role in reaching a more integral understanding of the etiology, pathogenesis, and treatment of this multifactorial disease. For the first time, the armamentarium available for the treatment of the different types and phases of BC is approached here from a Unitarian perspective-based upon the hydrogen ion dynamics of cancer. The wide-ranged pH-related molecular, biochemical and metabolic model is able to embrace most of the fields and subfields of breast cancer etiopathogenesis and treatment. This single and integrated approach allows advancing towards a unidirectional, concerted and synergistic program of treatment. Further efforts in this line are likely to first improve the therapeutics of each subtype of this tumor and every individual patient in every phase of the disease.

Metformin as Potential Therapy for High-Grade Glioma

Metformin (MET), 1,1-dimethylbiguanide hydrochloride, is a biguanide drug used as the first-line medication in the treatment of type 2 diabetes. The recent years have brought many observations showing metformin in its new role. The drug, commonly used in the therapy of diabetes, may also find application in the therapy of a vast variety of tumors. Its effectiveness has been demonstrated in colon, breast, prostate, pancreatic cancer, leukemia, melanoma, lung and endometrial carcinoma, as well as in gliomas. This is especially important in light of the poor options offered to patients in the case of high-grade gliomas, which include glioblastoma (GBM). A thorough understanding of the mechanism of action of metformin can make it possible to discover new drugs that could be used in neoplasm therapy.

Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial cancer of the head and neck with high prevalence in southern China, which is accompanied by notable invasiveness and metastasis. Long noncoding RNAs (lncRNAs) participate in the progression of various cancers including NPC. Microarray-based analysis identified highly expressed lncRNA mothers against decapentaplegic homolog 5 (SMAD5)-antisense RNA 1 (AS1) related to NPC. Interestingly, it is found that SMAD5-AS1 competitively bound to microRNA (miR)-106a-5p to regulate SMAD5. Herein, the study aimed to clarify the role of SMAD5-AS1/miR-106a-5p/SMAD5 axis in the process of epithelial mesenchymal transition (EMT) in NPC. SMAD5-AS1 was highly expressed and miR-106a-5p was poorly expressed in NPC tissues and cell lines. The NPC cells were treated with a series of small interfering RNAs, mimics, or inhibitors to explore the effects of SMAD5-AS1, SMAD5, and miR-106a-5p on EMT, cell proliferation, migration, and invasion in NPC. Of note, SMAD5-AS1 silencing or miR-106a-5p overexpression reduced expression of N-cadherin, matrix metallopeptidase 9, Snail, and Vimentin while elevating E-cadherin expression, thus inhibiting EMT, cell proliferation, migration, and invasion in NPC by down-regulation of SMAD5. Moreover, SMAD5 silencing could reduce the ability of EMT induced by SMAD5-AS1 up-regulation. SMAD5-AS1 silencing or miR-106a-5p elevation inhibited tumorigenesis in nude mice. Taken together, SMAD5-AS1 silencing suppressed EMT, cell proliferation, migration, and invasion in NPC by elevating miR-106a-5p to down-regulate SMAD5, which provided a novel therapeutic target for NPC treatment.-Zheng, Y.-J., Zhao, J.-Y., Liang, T.-S., Wang, P., Wang, J., Yang, D.-K., Liu, Z.-S. Long noncoding RNA SMAD5-AS1 acts as a microRNA-106a-5p sponge to promote epithelial mesenchymal transition in nasopharyngeal carcinoma.

Metformin and risk of developing nasopharyngeal cancer in patients with type 2 diabetes mellitus

BACKGROUND

Metformin has anticancer effects, but whether it can reduce the risk of nasopharyngeal cancer (NPC) is not known.

METHODS

A total of 15,486 ever-users and 15,486 never-users of metformin matched by propensity score were enrolled from among patients with new-onset type 2 diabetes mellitus diagnosed during the period 1999-2005 and who were found in the reimbursement database of Taiwan's National Health Insurance. The patients were followed until December 31, 2011. Hazard ratios were estimated by Cox regression incorporated with the inverse probability of treatment weighting using propensity scores.

RESULTS

NPC incidence was 33.41 and 106.04 per 100,000 person-years in ever-users and never-users, respectively. The overall hazard ratio (95% confidence interval) of 0.312 (0.197-0.494) favored a significantly lower risk among metformin ever-users than in never-users. Hazard ratios comparing the first (<26.03 months), second (26.03-58.03 months) and third (>58.03 months) tertiles of cumulative duration of metformin use to never-users were 0.690 (0.389-1.224), 0.187 (0.076-0.463) and 0.168 (0.068-0.415), respectively. A significantly lower risk of NPC was consistently observed among metformin users in subgroup analyses of age (<50 years and ≥50 years), sex (men and women), and patients with or without nephropathy, liver diseases or diseases of the esophagus, stomach, and duodenum, respectively.

CONCLUSIONS

Metformin use is associated with a significantly lower risk of NPC.

Metformin Treatment Inhibits Motility and Invasion of Glioblastoma Cancer Cells

Glioblastoma multiforme (GBM) is one of the most common and deadliest cancers of the central nervous system (CNS). GBMs high ability to infiltrate healthy brain tissues makes it difficult to remove surgically and account for its fatal outcomes. To improve the chances of survival, it is critical to screen for GBM-targeted anticancer agents with anti-invasive and antimigratory potential. Metformin, a commonly used drug for the treatment of diabetes, has recently emerged as a promising anticancer molecule. This prompted us, to investigate the anticancer potential of metformin against GBMs, specifically its effects on cell motility and invasion. The results show a significant decrease in the survival of SF268 cancer cells in response to treatment with metformin. Furthermore, metformin's efficiency in inhibiting 2D cell motility and cell invasion in addition to increasing cellular adhesion was also demonstrated in SF268 and U87 cells. Finally, AKT inactivation by downregulation of the phosphorylation level upon metformin treatment was also evidenced. In conclusion, this study provides insights into the anti-invasive antimetastatic potential of metformin as well as its underlying mechanism of action.

Metformin may protect nondiabetic breast cancer women from metastasis

Metformin, a widely prescribed oral hypoglycemic agent, has recently received a big interest because of its potential antitumorigenic effects in different cancer types. The present study investigated the impact of adding metformin to breast cancer adjuvant therapy in nondiabetic women on, insulin like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3), insulin, fasting blood glucose (FBG), the molar ratio of IGF-1 to IGFBP-3, homeostatic model assessment of insulin resistance (HOMA-IR) and metastasis. 102 women with newly diagnosed breast cancer were divided into 2 main groups, a control group and a metformin group. All women were treated with adjuvant therapy, according to the protocols of Ministry of Health and Population and National Cancer Institute, Egypt. Moreover, the women in the metformin group received 850 mg of metformin twice daily. Blood samples were collected at baseline, after chemotherapy (CT), after 6 months of hormonal therapy (6-HT) and 12 months of hormonal therapy (12-HT) for analysis of serum IGF-1, IGFBP-3, insulin, FBG and cancer antigen 15-3 (CA15-3). Metformin resulted in a significant reduction of IGF-1, IGF-1: IGFBP-3 molar ratio, insulin, FBG and HOMA-IR. On the other hand, metformin caused a significant increase of IGFBP-3. Moreover, metformin significantly decreased the numbers of metastatic cases after 6-HT. Metformin may have potential antitumor and antimetastatic effects that need further clinical investigations. This may be attributed to either the significant increase of the apoptotic inducer IGFBP-3 or/and the significant reduction of mitogenic insulin, IGF-1, free bioactive IGF-1, FBG and HOMA-IR.

Effects of metformin on cell kinetic parameters of MCF-7 breast cancer cells in vitro

In this study, the antiproliferative effects of the metformin was evaluated on MCF-7 Cells (human breast adenocarcinoma cell line). For this purpose cell kinetic parameters including cell proliferation assay, mitotic index and labelling index analysis were used. 30 μM, 65 μM and 130 μM Metformin doses were applied to cells for 24, 48 and 72 hours. The results showed that there was a significant decrease in cell proliferation, mitotic index and labelling index for all experimental groups (p<0.05) for all applications.

Evodiamine inhibits the migration and invasion of nasopharyngeal carcinoma cells in vitro via repressing MMP-2 expression

PURPOSE

Evodiamine is one of active alkaloids isolated from the traditional Chinese medicine Evodia rutaecarpa Bentham and has various pharmacological properties. In this study, we investigated its effects on the migration, invasion, and associated mechanism in human nasopharyngeal carcinoma (NPC) cells.

METHODS

Cell viability was determined by MTT assay after evodiamine treatment. Wound-healing assay and Boyden transwell system were used to evaluate the inhibitory effects of evodiamine on cell migration and invasion. MMP-2/9 activity was determined using commercial detection kits. The levels of associated proteins involved in the regulation of cell migration and invasion were analyzed by Western blotting.

RESULTS

Evodiamine effectively inhibited the migration and invasion of HONE1 and CNE1 cells, and hardly affected cell proliferation, but significantly suppressed cell adhesion activity in vitro. Additionally, evodiamine treatment significantly decreased mRNA and protein levels of MMP-2 and its activity in the NPC cells, but had little effects on MMP-9 mRNA and protein levels and its activity. Further investigation revealed that evodiamine inhibited the translocation of NF-κB p65, which involves the regulation of MMP-2 expression in cancer invasion. Additionally, evodiamine treatment did not significantly affect the protein levels of JNK, p38, Akt, and their phosphorylated forms and ERK1/2, but strongly attenuated ERK1/2 phosphorylation level, which at least partly accounts for the signal pathway of evodiamine-inhibited migration and invasion of NPC cells.

CONCLUSION

These findings demonstrate that evodiamine inhibits the migration and invasiveness of NPC cells, and it is probably a potential agent for the treatment of NPC invasion and metastasis.

Metformin inhibits the proliferation, metastasis, and cancer stem-like sphere formation in osteosarcoma MG63 cells in vitro

Metformin is an oral drug that has been widely used to treat type 2 diabetes mellitus. Interestingly, accumulated evidence indicate that metformin may reduce the risk of cancer in patients with type 2 diabetes and inhibit tumor cell growth and survival in numerous malignancies, including osteosarcoma (OS) cells. In the present study, we aimed to investigate the effects of metformin on the proliferation, migration, invasion, and sphere formation in OS MG63 cells in vitro. Metformin suppressed OS MG63 cell proliferation in a dose- and time-dependent manner and markedly blocked anti-metastatic potentials, migration, and invasion, by downregulating matrix metalloproteinase 2 (MMP2) and MMP9. Besides, we established OS cancer stem-like cell (CSC) model with sarcosphere formation assay and demonstrated that metformin posed damage on CSCs in OS by inhibiting sphere formation and by inducing their stemness loss. The stemness of CSCs in OS such as self-renewal and differentiation potentials was both impaired with a significant decrease of Oct-4 and Nanog activation. Consistent with this, the positive rates of CD90, CD133, and stage-specific embryonic antigen-4 (SSEA-4) were all observed with reductions in response to metformin exposure. In addition, Western blot showed that metformin activated AMPKα at Tyr172, followed by a downregulated phosphorylation of mammalian target of rapamycin (mTOR)/S6 and feedback activation of p-AKT Ser(473) in both OS MG63 cells and CSCs. This indicates that AMPK/mTOR/S6 signaling pathway might be involved in the growth inhibition of both OS MG63 cells and CSCs. These results suggest that metformin, a potential anti-neoplastic agent, might make it a novel therapeutic choice for the treatment of OS in the future.

microRNA-20a enhances the epithelial-to-mesenchymal transition of colorectal cancer cells by modulating matrix metalloproteinases

The mortality rates associated with colorectal cancer (CRC) are high due to metastasis. Epithelial-to-mesenchymal transition (EMT) is a key step in tumor metastasis. The aim of the present study was to investigate the function of microRNA-20a (miR-20a) in EMT. The expression of miR-20a was analyzed in CRC tissues and cell lines using the reverse transcription-quantitative polymerase chain reaction. Plasmids containing miR-20a short hairpin RNA and miR-20a mimics were transfected into SW620 and LS174T cell lines, respectively. Cell counting kit-8, Transwell® and wound healing assays were performed to assess the effects of miR-20a on cell proliferation, invasion and migration. EMT markers and matrix metalloproteinases (MMPs) were identified using western blotting. The results showed that increased expression of miR-20a in CRC tissues was associated with tumor invasion and lymph node metastasis (P<0.05). Further experiments indicated that miR-20a-knockdown inhibited the proliferation, invasion and migration of CRC cells, upregulated the expression of vimentin and tissue inhibitor of metalloproteinases-2 (TIMP-2) and downregulated the expression of E-cadherin, MMP-2 and MMP-9. The opposite effects were observed in CRC cell lines overexpressing miR-20a. In conclusion, these results have shown that the upregulation of miR-20a suppresses TIMP-2 expression, which subsequently increases the expression of MMP-2 and MMP-9, thereby promoting the EMT of CRC cells. These findings suggest that miR-20a represents a potential therapeutic target for patients with CRC.

Association of Epstein Barr virus A73 gene polymorphism with nasopharyngeal carcinoma

OBJECTIVE

To study the association between Epstein Barr (EB) virus A73 gene polymorphism and nasopharyngeal carcinoma (NPC) in a Chinese Han population.

METHODS

A case-control study was designed, including 510 nasopharyngeal cancer patients and 520 healthy controls, A157154C genotypes of the A73 gene in EB virus were detected, genotype and allele frequency distribution between the two groups were compared.

RESULTS

The C allele frequency in the NPC group was significantly higher than that in the control group (68.4% vs. 61.2%; p<0.001). The CC genotype frequency in the NPC group was significantly higher than that in the control group, the difference was significant (47.4% vs. 41.2%; p<0.001). The CC genotype frequency in male patients was significantly higher than that in female patients in the NPC group, the difference was significant (50.3% vs. 34.7%; p<0.001).

CONCLUSION

A157154C polymorphism of the A73 gene in EB virus was associated with NPC susceptibility.