miR-451对食管癌EC9706细胞增殖、凋亡及侵袭能力的影响

目的:探讨miR-451对食管癌EC9706细胞增殖、凋亡及侵袭能力的影响.方法:化学合成miR-451mimics,脂质体包裹转染EC9706细胞为miR-451组,同时设立无关序列(Scramble-miR)对照组、脂质体对照组和空白对照组.转染后48h,荧光定量RT-PCR检测miR-451表达量的变化,Westernblot检测Bcl-2、AKT和磷酸化AKT蛋白表达水平,流式细胞仪检测细胞凋亡情况,Transwell侵袭实验检测细胞侵袭能力的改变;MTT法检测转染后l、2、3、4、5、6d各组细胞增殖率.结果:miR-451组的miR-451表达水平显著上调(P<0.01,F=69.26),为空白对照组的15.84倍;miR-451组细胞Bcl-2、AKT和磷酸化AKT蛋白表达均显著下调(P<0.05,F=5.83);miR-451组细胞凋亡率为12.07%±1.12%,与3个对照组比较显著升高(P<0.01,F=26.72);miR-451组平均侵袭细胞数为47.4±7.4,与3个对照组比较显著降低(P<0.01,F=34.55).miR-451组细胞的生长在转染后2d出现显著抑制(P<0.05,F=5.95),并且随时间的延长而日益显著.结论:上调miR-451表达可抑制食管癌EC9706细胞增殖和侵袭,促进细胞凋亡.     

miR-21 Down-Regulation Suppresses Cell Growth, Invasion and Induces Cell Apoptosis by Targeting FASL, TIMP3, and RECK Genes in Esophageal Carcinoma

Background

miR-21 is overexpressed in esophageal squamous cell carcinoma (ESCC) and is thought to be correlated with the development of the cancer. The target gene of miR-21 including FASL, TIMP3 and RECK is revealed by researchers. miR-21 may be involved in the tumorgenesis of ESCC by targeting FASL, TIMP3 and RECK.

Aims

The purpose of this study was to explore the mechanism of miR-21 in the development of ESCC.

Methods

miR-21 expression in ESCC and the matched non-malignant adjacent tissues (NMATs) was examined by qRT-PCR. Cell growth, cell apoptosis and cell invasion ability of EC9706 and EC-1 cells was examined after the cells were transfected with miR-21 inhibitor. The potential target genes of miR-21 including FASL, TIMP3 and RECK were examined by western blot and Luciferase reporter assay.

Results

miR-21 expression was increased significantly in ESCC tissues compared with NMAT. miR-21 down-regulation inhibits cell growth, cell invasion and induces cells to apoptosis. FASL, TIMP3 and RECK are direct targets of miR-21.

Conclusions

miR-21 down-regulation inhibits cell growth, invasion and induces cells to apoptosis by targeting FASL, TIMP3 and RECK genes.     

MiR-451 inhibits proliferation of esophageal carcinoma cell line EC9706 by targeting CDKN2D and MAP3K1

AIM: To investigate the underlying molecular mechanisms of miR-451 to inhibit proliferation of esophageal carcinoma cell line EC9706.METHODS: Assays for cell growth, apoptosis and invasion were used to evaluate the effects of miR-451 expression on EC cells. Luciferase reporter and Western blot assays were used to test whether cyclin-dependent kinase inhibitor 2D(CDKN2D) and MAP3K1 act as major targets of miR-451.RESULTS: The results showed that CDKN2 D and MAP3K1 are direct targets of miR-451. CDKN2 D and MAP3K1 overexpression reversed the effect of miR-451.MiR-451 inhibited the proliferation of EC9706 by targeting CDKN2 D and MAP3K1.CONCLUSION: These findings suggest that miR-451 might be a novel prognostic biomarker and a potential target for the treatment of esophageal squamous cell carcinoma in the future.     

MiR-181d acts as a tumor suppressor in glioma by targeting K-ras and Bcl-2

Purpose

Recently, several microRNAs (miRNAs) were reported to be involved in the modulation of glioma development. The aim of our study was to determine the effect of miR-181d on the growth of glioma and to investigate whether this growth is modulated by targeting K-ras and Bcl-2.

Methods

Real-time PCR was used to analyze the expression of miR-181d in human glioma samples and glioma cell lines. Apoptosis, cell cycle, and proliferation (MTT) assays were performed to assess the phenotypic changes in glioma cells. Immunohistochemistry was used to determine the expression of K-ras and Bcl-2 in glioma tissues, and a luciferase reporter assay was carried out to confirm whether K-ras and Bcl-2 are direct targets of miR-181d. Western blotting was used to identify the potential signaling pathways affected glioma cell growth by miR-181d. In vivo, xenograft tumors were examined for an anti-glioma effect of miR-181d.

Results

MiR-181d was down-regulated in human glioma samples and up-regulated in transfected glioma cells. Ectopic expression of miR-181d suppressed proliferation and triggered cell cycle arrest and apoptosis in glioma cell lines. K-ras and Bcl-2 were identified as direct targets of miR-181d and were up-regulated in glioma samples. The results showed evidence linking the tumor suppressor activity of miR-181d in glioma cells with the K-ras-related PI3K/AKT and MAPK/ERK pathways. Furthermore, xenograft tumors from miR-181d-treated U251 cells were suppressed in vivo.

Conclusion

MiR-181d may act as a glioma suppressor by targeting K-ras and Bcl-2.     

miR-145 functions as tumor suppressor and targets two oncogenes,ANGPT2 and NEDD9, in renal cell carcinoma

Purpose

Abnormal expression of miRNAs is closely related to a variety of human cancers. The purpose of this study is to identify new tumor suppressor miRNA and elucidate its physiological function and mechanism in renal cell carcinoma (RCC).

Methods

The expression of miR-145 in 45 RCC and adjacent normal tissues was performed by quantitative RT-PCR. Cell proliferation, migration, invasion, apoptosis and cycle assays were carried out for functional analysis after miR-145 transfection. Two target genes of miR-145 were identified by luciferase reporter assay. The altered expression of 84 epithelial to mesenchymal transition (EMT)-related genes after miR-145 transfection was detected by RT² Profiler EMT PCR array.

Results

The expression of miR-145 was downregulated in RCC compared to their normal adjacent tissues. Restoring miR-145 expression in RCC cell lines dramatically suppressed cell proliferation, migration and invasion, and induced cell apoptosis and G2-phase arrest. We further validated those miR-145 targets two oncogenes, ANGPT2 and NEDD9 in RCC. In addition, miR-145 was found to regulate numerous genes involved in the EMT.

Conclusions

These findings demonstrate that miR-145 functions as tumor suppressor in RCC, suggesting that miR-145 may be a potential therapeutic target for RCC.     

Down-Regulation of PTEN Expression Modulated by Dysregulated miR-21 Contributes to the Progression of Esophageal Cancer

Background and Aim

miR-21, a putative tumor oncomiR, is a frequently overexpressed miRNA in a variety of tumors. Because it targets tumor-suppressor genes it has been linked to tumor progression. In this study we investigated the role of miR-21 in esophageal squamous cell carcinoma (ESCC), and its possible mechanism.

Methods

Expression of miR-21 was detected by stem–loop RT-PCR in tissue from 76 invasive ESCC at stage I–IV and in their corresponding para-cancerous histological normal tissues (PCHNT). Thirty endoscopic esophageal mucosal biopsy specimens from non-tumor patients were used as controls. Expression of PTEN in 76 paired ESCC and PCHNT was investigated by real-time RT-PCR and an immunohistochemical method, respectively. Paired tumor and PCHNT specimens of 20 ESCC cases were randomly selected for western blot analysis. The effect of miR-21 on PTEN expression was assessed in the ESCC cell line with an miR-21 inhibitor to reduce miR-21 expression. Furthermore, the roles of miR-21 in cell biology were analyzed by use of miR-21 inhibitor-transfected cells.

Results

Stem–loop RT-PCR revealed miR-21 was significantly overexpressed in ESCC tissues and cell lines. Overexpression of miR-21 correlated with tumor status, lymph node metastasis, and clinical stage. We demonstrated that knockdown of miR-21 significantly increased expression of PTEN protein. Consequent PTEN expression reduced cell proliferation, invasion, and migration.

Conclusions

Our findings suggest that miR-21 could be a potential oncomiR, probably by regulation of PTEN, and a novel prognostic factor for ESCC patients.     

Insulin-Like Growth Factor 1 Receptor Promotes the Growth and Chemoresistance of Pancreatic Cancer

Background

Insulin-like growth factor 1 receptor (IGF1R) plays important roles in the progression of pancreatic cancer. However, the underlying mechanism remains unclear.

Aims

The purpose of this study was to investigate the effects of IGF1R knockdown on the proliferation, apoptosis and chemosensitivity of pancreatic cancer cells, and explore the possible mechanisms.

Methods

Pancreatic cancer cells expressing IGF1R shRNA were established, and the cell proliferation, colony formation, and chemosensitivity to gemcitabine were examined in vitro. The activation of AKT and NF-κB was detected by Western blot analysis and luciferase assay, respectively. Xenograft mice models were established to evaluate the in vivo anti-tumor effects of IGF1R knockdown.

Results

IGF1R knockdown notably inhibited pancreatic cancer cell proliferation and colony formation, induced apoptosis, and inhibited xenograft tumor growth. Moreover, IGF1R knockdown significantly enhanced chemosensitivity to gemcitabine in pancreatic cancer cells, and this was correlated with the inhibition of PI3K/AKT and NF-κB pathways.

Conclusions

IGF1R knockdown suppresses tumor growth and enhances chemosensitivity in pancreatic cancer via the inhibition of PI3K/AKT and NF-κB pathways, and is a promising approach to overcome the chemoresistance of pancreatic cancer.     

miR-449a Regulates Proliferation and Chemosensitivity to Cisplatin by Targeting Cyclin D1 and BCL2 in SGC7901 Cells

Background

Recently, several miRNAs have been determined as tumor suppressors in various cancers, such as microRNA-449a. However, the exact molecular mechanisms underlying miR-449a regulated cell proliferation and chemosensitivity in gastric cancer cells have not been well documented.

Aim

The present study was designed to test whether miR-449a mediates cell proliferation and chemosensitivity in gastric cancer cells via regulating cyclin D1 and BCL2.

Methods

In vitro, the ability of cell proliferation and cell viability were measured by MTT assay; cell cycle and cell apoptosis was detected by FCM. qRT-PCR was used to measure the expression of miR-449a. Western blot and real-time PCR assays were used to detect the expression of cyclin D1 and BCL2 in gastric cancer cell line SGC7901.

Results

miR-449a expression was downregulated in gastric cancer cell line SGC7901 and human gastric cancer tissues, compared to the gastric epithelial cell line GES-1 and matched non-tumor associated tissues. Upregulation of miR-449a reduced the proliferation of SGC7901 cells. Ectopic expression of miR-449a decreased the percentage of S phase cells, increased the percentage of G1/G0 phase cells and increased the apoptosis induced by cisplatin. Moreover, miR-449a inhibited SGC7901 cells proliferation and enhanced cisplatin chemosensitivity by downregulating expression of BCL2 and cyclin D1, respectively, via directly targeting the 3′-untranslated regions of BCL2 and cyclin D1 mRNA.

Conclusions

This is the first report to provide evidence that miR-449a could modulate cell cycle and apoptosis through regulating cyclin D1 and BCL2 expression in SGC7901 cells.     

Upregulation of the Long Non-coding RNA PlncRNA-1 Promotes Esophageal Squamous Carcinoma Cell Proliferation and Correlates with Advanced Clinical Stage

Background

Recent studies revealed that long noncoding RNAs (lncRNAs) play critical regulatory roles in cancer biology. PlncRNA-1 is one of lncRNAs that is associated with cell apoptosis and proliferation of prostate cancer.

Aim

This study aimed to assess the potential role of PlncRNA-1 in the pathogenesis of esophageal squamous cell carcinoma (ESCC).

Materials and Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of PlncRNA-1 in 73 pairs of ESCC and their matched normal tissues. The correlation of PlncRNA-1 with clinicopathological features and clinical stages was also analyzed. Cancer cell proliferation and apoptosis were assessed following knock-down of PlncRNA-1 by MTT, colony formation assay, and flow cytometry.

Results

The expression of PlncRNA-1 was significantly higher in human ESCC compared with the adjacent noncancerous tissues (69.8 %, p < 0.05), and the high level of PlncRNA-1 expression was significantly correlated with advanced clinical stage (p < 0.01) and lymph node metastasis (p < 0.05). Furthermore, knockdown of PlncRNA-1 reduced cell proliferation and increased the apoptosis in vitro.

Conclusions

PlncRNA-1 plays an important role in ESCC cell proliferation. Overexpression of PlncRNA-1 is correlated with advanced tumor stage and lymph node metastasis, and may serve as a potential prognostic marker and therapeutic target for ESCC.     

miR-638 Suppresses Cell Proliferation in Gastric Cancer by Targeting Sp2

Background

MicroRNAs play important roles in the development and progression of various cancers. Recent studies have shown that miR-638 was downregulated in several tumors; however, its role in gastric cancer (GC) has not been investigated in detail.

Aims

The purpose of this study was to determine the role of miR-638 and to elucidate its regulatory mechanism in GC.

Methods

The expression levels of miR-638 and specificity protein 2 (Sp2) were detected by real-time PCR and Western blotting in GC. After pcDNA6.2-GW/EmGFP-miR-638 vector, miR-638 inhibitor and Sp2-siRNA transfection, the AGS cell proliferation was investigated by MTT assay and cell cycle, and apoptosis was detected using the Annexin V/PI. In addition, the regulation of Sp2 by miR-638 was evaluated by real-time RT-PCR, Western blot and luciferase reporter assays; cyclin D1 expression was measured by Western blotting.

Results

The expression of miR-638 is dramatically down-regulated and Sp2 expression is remarkably up-regulated in GC tissues. Luciferase assays revealed that miR-638 inhibited Sp2 expression by targeting the 3′-UTR of Sp2 mRNA. Overexpression of miR-638 and Sp2-siRNA reduced Sp2 expression at both the mRNA and protein levels in vitro, and inhibition of miR-638 increased Sp2 expression. Moreover, we found that miR-638 overexpression and Sp2-siRNA markedly suppressed cell proliferation with decreasing expression of cyclin D1 and inducing G1-phase cell-cycle arrest in vitro; inhibition of miR-638 significantly promoted cell proliferation by increasing expression of cyclin D1 and leading more cells into the S and G2/M phase.

Conclusions

Our results demonstrated that miR-638 suppressed GC cell proliferation by targeting Sp2 with influence on the expression of cyclin D1. We suggest that miR-638 might be a candidate predictor or an anticancer therapeutic target for GC patients.     

Thymoquinone Augments Cisplatin-Induced Apoptosis on Esophageal Carcinoma Through Mitigating the Activation of JAK2/STAT3 Pathway

Background

Thymoquinone (TQ) is the major constituent of Nigella sativa seed and has shown biological activity in various human carcinomas. However, few studies have reported its effect on esophageal carcinoma (EC).

Aims

To explore the chemosensitive effect and mechanism of TQ in augmentation of cisplatin (DDP)-induced apoptosis of EC, both in vitro and in vivo.

Methods

The viability and apoptosis of esophageal carcinoma cells were detected by the Cell Counting Kit-8 assay, flow cytometry, and Hoechst 33258 staining. The expression levels of JAK2, p-JAK2, STAT3, p-STAT3, Bax, Bcl-2, Cyclin D1, Survivin, and caspase-3, 7, 9 were evaluated by western blot analysis. The histological changes were examined by TUNEL technique and immunohistochemical analysis.

Results

TQ enhanced the proapoptotic effect of DDP in human esophageal carcinoma cell line Eca-109, while blocking the activation of JAK2/STAT3 signaling pathway. The apoptosis of esophageal carcinoma cells was induced via blocking the activation of JAK2/STAT3 by using a molecular inhibitor (WP1066). Consistent with the in vivo and in vitro results, TQ increased cellular apoptosis and enriched the chemosensitivity of DDP.

Conclusions

TQ along with DDP may regulate the progression of EC and has potential to be a chemotherapeutic agent in EC.

     

miR-708 promotes the development of bladder carcinoma via direct repression of Caspase-2

Purpose

Bladder cancer is one of the world’s top ten malignant tumors. The crucial role of microRNA in carcinogenesis has been well emphasized. Considering miRNA expression was tumor stage-, tissue-, or even development-specific, more experimental evidences about the functions of miRNAs in bladder cancer should be discovered to advance applying of miRNA in the diagnosis or therapy of cancer.

Methods

MiR-708 level in bladder carcinoma and adjacent noncancerous tissues was tested by real-time qPCR. Cell apoptosis was analyzed by using flow cytometry. The tumorigenicity of bladder carcinoma cells was evaluated in nude mice model. Luciferase reporter gene assays were performed to identify the interaction between miR-708 and 3′UTR of Caspase-2 mRNA. The protein level of Caspase-2 was determined by western blotting.

Results

In this study, we reported that miR-708 was frequently dysregulated in human bladder carcinoma tissues compared to normal tissues. In addition, we found that silencing of miR-708 could promote the T24 and 5637 cells to apoptosis and inhibit the bladder tumor growth in vivo. Also, Caspase-2 was proved to be one of direct targets of miR-708 in T24 and 5637 cells. Further results showed that Caspase-2 was involved in the miR-708 regulated cell apoptosis.

Conclusions

All together, these results suggest miR-708 may act as an oncogene and induce the carcinogenicity of bladder cancer by down-regulating Caspase-2 level.     

MicroRNA-92a Functions as an Oncogene in Colorectal Cancer by Targeting PTEN

Background

Our previous studies show that microRNA-92a (miR-92a) is overexpressed in colorectal cancer (CRC) and is thought to be correlated with the development of the cancer. However, its biological role in CRC remains poorly understood.

Aims

The aim of the study was to determine the role of miR-92a and to elucidate its regulatory mechanism in CRC.

Methods

The expression levels of miR-92a and phosphatase and tensin homologue (PTEN) were detected by qRT-PCR and western blot. MTT, migration and invasion assays were used to examine the proliferation, migration and invasion of pre-miR-92a transfected SW480 cells, and a mouse model was used to investigate tumorigenesis. In addition, the regulation of PTEN by miR-92a was evaluated by qRT-PCR, western blot and luciferase reporter assays.

Results

The expression of miR-92a was significantly up-regulated in the tissues of CRC patients with lymph node metastasis. The ectopic expression of miR-92a enhanced CRC cell proliferation, migration and invasion. Similar results were found in xenograft assay performed in nude mice. Up-regulation of miR-92a induced EMT in CRC cells. There was an inverse correlation between the levels of miR-92a and PTEN in CRC tissues. The overexpression of miR-92a in CRC cells decreased PTEN expression at the translational level, and decreased PTEN-driven luciferase-reporter activity.

Conclusions

Our results demonstrated that miR-92a induced EMT and regulated cell growth, migration and invasion in the SW480 cells, at least partially, via suppression of PTEN expression. MiR-92a may serve as a novel therapeutic target in colorectal cancer.     

Impact of erythropoietin on the effects of irradiation under hypoxia

Purpose

Head and neck squamous cell carcinoma (HNSCC) represents an ideal model for assessing the impact of anemia and tumor hypoxia on the response to radiotherapy (RT). Various treatment strategies aimed at increasing tumor oxygenation in HNSCC patients have been studied and these studies have been fueled by evidence that hypoxia and, unexpectedly, erythropoietin (EPO), adversely affect the radiosensitivity of cells. The purpose of the present study was to experimentally examine the relationship between hypoxia, EPO, its receptor EPOR, EGFR and their effects on the survival and radiosensitivity of HNSCC cells underwent hypoxia.

Methods

We used Cal-166 head and neck cell line to investigate different cellular responses after RT given in oxic and hypoxic conditions, focusing on the role of EPO administration in cell proliferation and in regulating response to RT.

Results

Our results show that EPO do not evoke a physiologic response on EPOR-bearing tumor cells as assessed by cellular growth and proliferation. In addition, we present some indications that EPO could activate opposite signals related to proliferation, DNA repair and apoptosis. Among them, EGFR and AKT phosphorylation may play a role in radioresistance.

Conclusions

We concluded that the expression of the EPOR in Cal-166 cells does not seem essential for their growth and that administration of EPO does not affect RT efficacy.     

Higher expression of SIRT1 induced resistance of esophageal squamous cell carcinoma cells to cisplatin

Background

High expression of Sirtuin type 1 (SIRT1) exists in some cancer cells. However, it is still unclear whether SIRT1 affects the sensitivity of esophageal cancer cells to cisplatin. This study was designed to explore the relationship between SIRT1 expression and resistance of esophageal squamous cell carcinoma (ESCC) cells to cisplatin and reveal the underlying mechanism.

Methods

The tissue samples of 68 ESCC patients were collected from Nanjing Drum Tower Hospital, China. All the patients had undergone cisplatin based combination chemotherapy. The expression of SIRT1and Noxa in tissue samples were analyzed by quantitative real-time reverse PCR (qRT-PCR) and Western blot. Human ESCC cell line (ECa9706 cells) was cultured and a cisplatin-resistant subline (ECa9706-CisR cells) was established by continuous exposure to cisplatin at different concentrations. The expression of SIRT1 and Noxa in both cell lines was analyzed by qRT-PCR and Western blot. siRNA technology was utilized to down-regulate the SIRT1 expression in ECa9706-CisR cells. The influence of SIRT1 silence on sensitivity of ECa9706-CisR cells to cisplatin was confirmed using CCK-8 assay and flow cytometry. Furthermore, the level change of Noxa after SIRT1 silence in ECa9706-CisR cells was determined by qRT-PCR and Western blot.

Result

SIRT1 and Noxa expression in chemo-resistant patients was significantly increased and decreased respectively, compared with chemo-sensitive patients. SIRT1 expression in ECa9706-CisR cells was significantly increased with a lower Noxa level, compared with normal ECa9706 cells. Cisplatin 5 µM could cause proliferation inhibition, G2/M phase arrest and apoptosis in ECa9706-CisR cells and these effects could be enhanced dramatically by SIRT1 silencing. Moreover, Noxa expression was increased after treated with SIRT1 siRNA.

Conclusions

Over-expression of SIRT1 may cause resistance of ESCC cells to cisplatin through the mechanism involved with Noxa expression.     

Downregulating sCLU Enhances the Sensitivity of Hepatocellular Carcinoma Cells to Gemcitabine by Activating the Intrinsic Apoptosis Pathway

Purpose

The purpose of this study was to investigate whether the therapeutic activity of gemcitabine (GCB) in hepatocellular carcinoma (HCC) could be increased by the down-regulation of secretory clusterin (sCLU), a glycoprotein that is considered to play a cytoprotective role in the resistance to chemotherapy.

Methods

The expression of sCLU was detected in HCC tumor tissues and cell lines. A cell viability and apoptosis assay were performed in parental HCC cells or the same cells transfected with sCLU shRNA and treated with or without GCB. The potential downstream pathways were investigated using the Human Apoptosis RT² Profiler? PCR Array.

Results

The expression levels of sCLU in HCC tissues were significantly higher than in adjacent non-tumor liver tissues and were associated with the histological grade and transarterial chemoembolization. sCLU overexpression was also found in three HCC cell lines and hepatocytes. The depletion of sCLU synergistically increased GCB sensitivity in Bel7402 and SMMC7721 cells and induced cell apoptosis. Based on the PCR array analysis, sCLU depletion also resulted in the up-regulation of BNIP1, GADD45A, TNFRSF10A, and TRADD and down-regulation of AKT1 in Bel7402 and SMMC7721 cells compared with the parental controls. These results were further supported by a Western blot analysis, which showed increased GADD45a protein expression and the decreased expression of phosphorylated AKT. GADD45a overexpression also increased the sensitivity to GCB in the Bel7402 and SMMC7721 cells.

Conclusion

Targeting sCLU may be a useful method to enhance the cytotoxic effect of GCB in hepatocellular carcinoma.     

SULF1 Inhibits Proliferation and Invasion of Esophageal Squamous Cell Carcinoma Cells by Decreasing Heparin-Binding Growth Factor Signaling

Background

Heparin-binding growth factor signaling is involved in the pathogenesis and development of human cancers. It can be regulated by sulfation of cell-surface heparan sulfate proteoglycans (HSPG). SULF1 is a heparin-degrading endosulfatase which can modulate the sulfation of HSPGs.

Aim

The purpose of this study was to elucidate the role of SULF1 in modulating proliferation and invasion of esophageal squamous cell carcinoma (ESCC) by decreasing heparin-binding growth factor signaling.

Methods

We restored SULF1 expression in the ESCC cell line KYSE150, and examined the effects of SULF1 expression on the proliferation and invasion of KYSE150 cells. In addition, we investigated the expression of SULF1 in human ESCC tissues and analyzed the correlation of SULF1 expression with clinicopathologic characteristics of ESCC.

Results

Our study shows that re-expression of SULF1 in ESCC cell line results in the downregulation of hepatocyte growth factor-mediated activation of MAPK pathways with a resultant decrease in cell invasiveness. Cell proliferation was also inhibited in SULF1-transfected KYSE150 cells. Immunohistochemical assays reveal that SULF1 is expressed in nearly half of the human ESCC tissues but not in normal esophageal epithelial cells. SULF1 expression in human ESCC tissues is negatively correlated with tumor size and tumor invasion.

Conclusion

This study identified that SULF1 inhibits proliferation and invasion of ESCC by decreasing heparin-binding growth factor signaling and suggested that SULF1 plays an inhibiting role in the pathogenesis of ESCC.     

miR-21 induces cell cycle at S phase and modulates cell proliferation by down-regulating hMSH2 in lung cancer

Purpose

MicroRNAs regulate critical genes associated with lung cancer. Human mutS homolog 2 (hMSH2), one of the core mismatch repair genes, is affected in lung cancer development. The aim of this study is to investigate the role of miR-21 in hMSH2 gene expression and the effect of miR-21 on cell proliferation and cell cycle in lung cancer.

Methods

The targets of miR-21 were predicted by a bioinformatics tool, and hMSH2 was validated as a direct target of miR-21 by luciferase activity assay. MiRNA mimics or inhibitors were used to stimulate or attenuate the effect of endogenous miR-21 on hMSH2 expression. MiR-21 and hMSH2 expressions were assessed with real-time RT-PCR and Western blotting. Cell cycle was determined by flow cytometry, and cell growth was analyzed by MTT assay and real-time cell analysis system.

Results

MiR-21 expression was inversely correlated with hMSH2 expression in human lung cancer cell lines. Further validation showed hMSH2 was directly regulated by miR-21. The up-regulation of miR-21 significantly promoted cell proliferation and revealed a higher proportion of cells at S phase. However, knockdown of miR-21 expression resulted in cell cycle arrest at G2/M phase and inhibited cell proliferation.

Conclusions

These data suggest miR-21 is a key regulator of hMSH2 and modulates cell cycle and proliferation by targeting hMSH2 in human lung cancer.