TGF-β1 Secreted by Hepatocellular Carcinoma Induces the Expression of the Foxp3 Gene and Suppresses Antitumor Immunity in the Tumor Microenvironment

Aim

The purpose of this study was to explore the mechanisms of TGF-β1 mediated immunosuppression in tumor stroma.

Methods

The expression of TGF-β1 was investigated in Huh7, Hep 3B, SGC-7901, Eca-109 and Hepa1-6 cell lines using immunofluorescence. Knocked-down TGF-β1 of the Hepa1-6 cell line was established through lentivirus-based RNA interference. The interference efficiency of the TGF-β1 gene was tested by real-time PCR and ELISA; the expression of Foxp3, IFN-γ and CD83 in CD4⁺, CD8⁺ or dendritic cells was examined via flow cytometry; and the tumorigenic ability of the cancer cells was investigated in the animal experiments.

Results

The diverse digestive cancer cells were found to secrete TGF-β1, mRNA of which was knocked down by 78 % thanks to lentivirus-based interference in Hepa1-6 cells. Flow cytometry showed that CD4⁺CD25⁺Foxp3⁺ regulatory T cells significantly increased in hepatocellular carcinoma patients when compared with those in the healthy controls. The supernatant from Hepa1-6 cells and recombinant TGF-β1 significantly induced the expression of Foxp3 gene in vitro, while that from sh TGF-β1 Hepa1-6 cells restored it. Hepa1-6 cells inhibited IFN-γ and CD83 expression in CD8⁺ or dendritic cells by secreting TGF-β1. The animal experiments indicated that the knockdown TGF-β1 gene impaired the tumorigenic ability of Hepa1-6 cells.

Conclusion

TGF-β1, expressed in cancer cells, might be a potential therapeutic target for cancer treatment.     

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.     

Increased Expression of Cellular Repressor of E1A-Stimulated Gene (CREG) in Gastric Cancer Patients: A Mechanism of Proliferation and Metastasis in Cancer

Background

The cellular repressor of E1A-stimulated genes (CREG), a secreted glycoprotein, has been studied with human embryonic carcinoma cells, vascular smooth muscle cells, and NIH3T3 fibroblasts. However, its relationship to tumor cell proliferation and metastasis has not been examined in human gastric cancers (GC) until now.

Aim

To investigate the expression of CREG in GC and its association with GC cell proliferation and metastasis.

Methods

Forty-two cases of GCs, matched normal gastric tissues, and the human gastric cancer cell lines BGC-823, SGC-7901, MKN45, normal gastric mucosa cell line GES, and HUVEC cell line ECV304 were used to analyze CREG expression at the level of mRNA and protein. The expression of CREG was then further examined by immunohistochemistry in 42 GC tissues, and the correlation between the level of CREG and the pathological and clinical data was evaluated. Finally, we down-regulated the expression of CREG in GC cells with specific siRNA, and assessed the role of CREG in the proliferation and metastasis/invasion of the GC cell line.

Results

The level of CREG was found to be higher in malignant GC tissues and cells compared to adjacent normal tissues and normal gastric cells (p < 0.001). Additionally, the expression levels of CREG were positively correlated with tumor clinical stage (p = 0.001), tumor metastasis (p < 0.001), and stages of tumor infiltration (p = 0.019). Furthermore, by using siRNA, we found that the down-regulated expression of CREG inhibited the proliferation of GC cells (p < 0.05), and migration of both GC cells (p = 0.001).

Conclusions

Our data suggest that CREG plays an important role in gastric cancer cell proliferation and metastasis and that CREG may be a potential therapeutic target for GC.     

S100A6 as a Potential Serum Prognostic Biomarker and Therapeutic Target in Gastric Cancer

Background

Increased expression of S100A6 in many cancer tissues and its association with tumor behavior and patient prognosis were demonstrated, and there are no studies analyzing the serum levels of S100A6 in patients with gastric cancer (GC).

Aim

Serum S100A6 levels were investigated as a marker of tumor aggressiveness in patients with GC, and the S100A6 gene was examined as a potential therapeutic target in GC.

Methods

Serum S100A6 levels were detected in 103 GC patients and 72 healthy subjects by ELISA. Clinicopathological features of GC patients were analyzed in correlation to serum S100A6 levels. Two small interfering RNAs against S100A6 (siRNA1-S100A6 and siRNA2-S100A6) were generated and transfected into SGC7901 cells using pSUPER gfp-neo vector, and the effects of S100A6 knockdown on cell proliferation, invasion and apoptosis were evaluated in vitro. The effects of S100A6 silencing on tumor growth and metastasis were evaluated in vivo in a pseudo-metastatic GC nude mouse model.

Results

Serum S100A6 levels were significantly higher in GC patients than in healthy controls (P < 0.001). Serum S100A6 levels were significantly correlated with lymph node metastasis, TNM stage, perineural invasion and vascular invasion. Serum S100A6 level was an independent predictor of overall survival. SiRNA-mediated silencing of S100A6 significantly induced apoptosis and decreased proliferation, clone formation and the invasiveness of GC SGC7901 cells in vitro and significantly reduced tumor volume and number in vivo (P < 0.01).

Conclusion

Serum S100A6 level may serve as a potential prognostic biomarker in GC. Inhibition of S100A6 decreased the metastatic potential of GC cells.     

Cotransfection of Survivin and CD44v3 Short Hairpin RNAs Affects Proliferation, Apoptosis, and Invasiveness of Colorectal Cancer

Introduction

Colorectal cancer is one of the common malignant tumors in humans, and the incidence rate is gradually increasing year by year. Survivin and CD44v3 are ideal targets for gene therapy due to their overexpression in colorectal cells. Studies show that downregulation of survivin could promote apoptosis and depress proliferation, and reduction of CD44v3 expression could inhibit tumor invasive capacity. It is difficult to achieve satisfactory curative effect.

Objective

In this study, we use survivin and CD44v3 short hairpin RNAs (shRNA) combined transfection into colorectal cancer cell line SW480 to investigate its effects on the cell apoptosis, proliferation and invasiveness.

Methods

ShRNA plasmids targeting survivin and CD44v3 were singly or co-transfected into SW480 cells.

Results

The co-transfection group exhibited the most significant inhibitory effect on cell growth (P < 0.05) and the highest apoptosis rate (P < 0.05). In addition, the invasive capacity in the co-transfected group was the least. The tumor inhibition rate of the cotransfected group in xenograft tumor mice was significantly higher than other groups (P < 0.05). Moreover, the microvessel density of the co-transfected group was significantly decreased compared with other groups (P < 0.05).

Conclusion

These results suggest combined transfection of survivin shRNA and CD44v3 shRNA may produce a synergistic effect on gene therapy in colorectal cancer.     

Piezo1 Is as a Novel Trefoil Factor Family 1 Binding Protein that Promotes Gastric Cancer Cell Mobility In Vitro

Background

Trefoil factor family 1 (TFF1) is a member of the TFF-domain peptide family involved in epithelial restitution and cell motility. Recently, we screened Piezo1 as a candidate TFF1-binding protein.

Aim

We aimed to confirm Piezo1 as a novel TFF1 binding protein and to assess the role of this interaction in mediating gastric cancer cell mobility.

Methods

This interaction was confirmed by co-immunoprecipitation and co-localisation of TFF1 and Piezo1 in GES-1 cells. We used stable RNA interference to knockdown Piezo1 protein expression and restored the expression of TFF1 in the gastric cancer cell lines SGC-7901 and BGC-823. Cell motility was evaluated using invasion assay and migration assay in vitro. The expression levels of the integrin subunits β1, β5, α1 as well as the expression of β-catenin and E-cadherin were detected by Western blot.

Results

We demonstrate that TFF1, but not TFF2 or TFF3, bind to and co-localize with Piezo1 in the cytoplasm in vitro. TFF1 interacts with the C-terminal portion of the Piezo1 protein. Wound healing and trans-well assays demonstrated that the restored expression of TFF1 promoted cell mobility in gastric cancer cells, and this effect was attenuated by the knockdown of Piezo1. Western blots demonstrated the decreased expression of integrin β1 in Piezo1-knockdown cells.

Conclusions

Our data demonstrate that Piezo1 is a novel TFF1 binding protein that is important for TFF1-mediated cell migration and suggest that this interaction may be a therapeutic target in the invasion and metastasis of gastric cancer.     

DNA Methylation of NDRG2 in Gastric Cancer and Its Clinical Significance

Background

Gastric cancer is one of the most common digestive malignancies worldwide. N-myc downstream-regulated gene 2 (NDRG2) is a differentiation-related gene that is considered to be a metastasis suppressor gene. In this study, we examined the expression and DNA methylation of NDRG2 in gastric cancer cell lines and tissues, as well as its clinical significance.

Methods

Six gastric cancer cell lines and 42 paired normal and gastric cancer tissue samples were used to assess NDRG2 mRNA expression using RT-PCR. NDRG2 DNA methylation status was evaluated by methylation-specific PCR (MSP) in gastric cancer cell lines and tissues. The suppression of NDRG2 in BGC823 cells by siRNA transfection was utilized to detect the role of NDRG2 in gastric cancer progression.

Results

NDRG2 mRNA was down-regulated in gastric cancer cell lines and tissues, and its expression was just related to lymph node metastasis (p = 0.032). MSP showed methylation of NDRG2 in 54.0 % (47/87) of primary gastric cancer specimens and in 20.0 % (16/80) of corresponding nonmalignant gastric tissues. NDRG2 methylation was related to depth of tumor invasion, Borrmann classification and TNM stage (p < 0.05). Upon treatment with 5-aza-2′-deoxycytidine and trichostatin A, NDRG2 expression was upregulated in HGC27 cells, and demethylation of the highly metastatic cell line, MKN45, inhibited cell invasion. Furthermore, the suppression of NDRG2 by siRNA transfection enhanced BGC823 cells invasion.

Conclusions

Our results suggest that the aberrant methylation of NDRG2 may be mainly responsible for its downregulation in gastric cancer, and may play an important role in the metastasis of gastric cancer.     

Egr-1 Promotes Cell Proliferation and Invasion by Increasing β-Catenin Expression in Gastric Cancer

Background

Abnormal expression of early growth response gene 1 (Egr-1) and β-catenin may play a crucial role in the development and progression of human cancer. However, little is known about the expression and underlying molecular mechanisms in which Egr-1 and β-catenin are involved in the development and progression of gastric cancer.

Aims

The purpose of this study was to elucidate the potential relationship between Egr-1 and β-catenin expression in gastric cancer, which contributes to finding new molecular carcinogenesis as a potential therapeutic target for gastric cancer.

Methods

In a sample of 102 cases of human gastric cancer, the expression of Egr-1 and β-catenin was detected using immunohistochemistry. Egr-1 gene was transfected into gastric cancer SGC7901 cells and its role in proliferation and cell invasion was detected by MTT assay, flow cytometry, wound-healing and transwell invasion assay. Western blot analysis was used to study the expression of β-catenin and cyclin D1 proteins.

Results

Upregulated Egr-1 and β-catenin protein expression were strongly correlated with cancer progression and depth of invasion in gastric cancer. β-catenin, present mainly in cytoplasmic and nucleus of gastric cancer cells, was also positively correlated with Egr-1 expression in gastric cancer. Furthermore, the overexpression of Egr-1 upregulated β-catenin expression level, promoted cell proliferation, increased cell population in S-phase and enhanced gastric cancer cell migration and invasion in vitro.

Conclusions

Egr-1 might contribute to gastric cancer proliferation and invasion through activation of the β-catenin signaling pathway.     

AEG-1 Is a Target of Perifosine and Is Over-Expressed in Gastric Dysplasia and Cancers

Background

Perifosine, an alkylphospholipid, is an Akt inhibitor which inhibits the growth of diverse cancer cells. We have reported its inhibitory effects on the growth of gastric cancer cells recently, but its molecular mechanisms are still largely unknown.

Aims

The purpose of this study was to investigate the effect and regulatory mechanism of perifosine in gastric cancer.

Methods

Cell viability was determined by sulforhodamine B assay after transiently transfected with AEG-1 specific siRNAs. qRT-PCR and western blot assay were used to determine the mRNA expression and proteins levels of cell signaling molecules examined. Immunohistochemistry was used to detect the AEG-1 expression in 87 gastric carcinomas, 60 dysplasia, and 47 normal gastric mucosa.

Results

Perifosine decreased AEG-1 gene expression along with inhibition of Akt/GSK3β/C-MYC signaling pathway. Knockdown of AEG-1 using siRNA led to significant down-regulation of cyclin D1 expression at both mRNA level and protein level, and inhibited the growth of gastric cancer cells. AEG-1 expression was elevated in gastric dysplasia and cancer tissues compared to normal gastric mucosa (P < 0.01). AEG-1 over-expression correlated with diffuse type of gastric cancer and advanced tumor stages.

Conclusions

Perifosine inhibits the growth of gastric cancer cells possibly through inhibition of the Akt/GSK3β/C-MYC signaling pathway—mediated down-regulation of AEG-1 that subsequently down-regulated cyclin D1. AEG-1 may play an important role in the carcinogenesis and progression of gastric cancer and could be a therapeutic target of perifosine.     

RKIP and 14-3-3ε Exert an Opposite Effect on Human Gastric Cancer Cells SGC7901 by Regulating the ERK/MAPK Pathway Differently

Background

Raf-1 kinase inhibitor protein (RKIP) inhibits Raf (a key element in the ERK/MAPK pathway) and is regarded as anti-tumoral. In contrast, 14-3-3 is considered protumoral. However, the pathogenetic role of RKIP and 14-3-3ε in gastric cancer is unclear.

Aim

The purpose of this study was to examine the influence of 14-3-3ε and RKIP on SGC7901, the regulation of the ERK/MAKP pathway by both, and the interaction between the two proteins.

Methods

RKIP and 14-3-3ε genes were introduced into SGC7901 cells using gene cloning technique, then, the bioactivities including the proliferation, migration and invasion of the cells were assessed by MTT and migration assays. ERK/MAKP pathway’s activity was examined using real-time quantitative RT–PCR, western blot, immunoprecipitation and 3D-immunolocalization techniques.

Results

Our results showed that RKIP inhibited SGC7901 cells’ bioactivities whereas 14-3-3ε upregulated them through the involvement of the ERK/MAPK pathway. RKIP inactivated this pathway, but 14-3-3ε activated it. RKIP and 14-3-3ε were co-localized in the cells and interacted with each other; this attributed to their opposite influence on the ERK/MAPK pathway and the cells bioactivities.

Conclusions

The ERK/MAPK pathway is involved in the pathogenesis of gastric cancer; RKIP and 14-3-3ε exert an opposite effect on this pathway and the cells possibly via both direct and indirect reactions with the elements in this pathway. The interaction between RKIP and 14-3-3ε may also contribute to their pathogenetic roles in gastric cancer.     

Interaction between cyclooxygenase-2,Snail,and E-cadherin in gastric cancer cells

AIM:To investigate the mechanisms of how cyclooxygenase-2(COX-2)regulates E-cadherin in gastric cancer cells.METHODS:COX-2 expression in human gastric cancer cell lines SGC-7901,BGC-823,MGC-803 and AGS were measured at the mRNA and protein level.COX-2 rich cell line SGC-7901 was chosen for subsequent experiments.siRNA mediated gene knockdown was used to investigate the impact of COX-2 on nuclear factor-κB (NF-κB),Snail,and E-cadherin in gastric cancer cells.Gene expression was determined by Western blot and real-time polymerase chain reaction.To analyze whether NF-κB inhibition could interrupt the modulatory effect of COX-2 or prostaglandin E2(PGE2)on E-cadherin,gastric cancer cells were treated with celecoxib or PGE2,in the presence of NF-κB specific siRNA.RESULTS:Highest expression level of COX-2 was found in SGC-7901 cells,both at mRNA and protein levels.siRNA mediated down-regulation of COX-2 led to a reduced expression of NF-κB and Snail,but an increased expression of E-cadherin in SGC-7901 cells.siRNA mediated down-regulation of NF-κB also led to a reduced expression of E-cadherin and Snail in SGC-7901 cells.However,COX-2 expression did not alter after cells were treated with NF-κB specific siRNA in SGC-7901 cells.Treatment of SGC-7901 cells with celecoxib led to a reduced expression of Snail but an increased expression of E-cadherin.In contrast,treatment of SGC-7901 cells with PGE2 led to an increased Snail and a decreased E-cadherin.However,siRNAmediated knockdown of NF-κB partially abolished the effect of celecoxib and PGE2 on the regulation of E-cadherin and Snail in SGC-7901 cells.CONCLUSION:COX-2 likely functions upstream of NF-κB and regulates the expression of E-cadherin via NF-κB/Snail signaling pathway in gastric cancer cells.     

Genetic association of osteopontin (OPN) and its receptor CD44 genes with susceptibility to Chinese gastric cancer patients

Purpose

(1) To investigate associations between single nucleotide polymorphisms (SNPs) in osteopontin (OPN) and its receptor—cluster of differentiation 44 (CD44) genes and gastric cancer susceptibility. (2) To explore the correlation of OPN and CD44 expression of gastric cancer.

Methods

We detected 26 SNPs of the genes in gastric cancer patients from the Chinese Han population by Sequenom technique and performed expression of OPN in combination with CD44 in 243 tissues samples of the cases by tissue microarray and immunohistochemistry (IHC).

Results

We found that the minor alleles of OPN rs4754C>T and OPN rs9138C>A remained strongly associated with decreased gastric cancer risk (P = 1.53 × 10^?4, odds ratio (OR) 0.642, 95 % confidence interval (CI) 0.511–0.808 and P = 1.59 × 10^?4, OR 0.642, 95 %CI 0.510–0.809). OPN variant rs1126772A>G and CD44 variant rs353639A>C significantly contributed to elevated risk of gastric cancer (P = 0.042, OR 1.279, 95 % CI 1.008–1.622 and P = 0.047, OR 1.334, 95 % CI 1.003–1.772). Haplotypes of OPN and CD44 variants significantly influenced risk of gastric cancer. Clinical data indicated that rs4754 and rs9138 of OPN were significantly associated with smoking (P = 0.029, OR 0.343, 95 % CI 0.127–0.926 and P = 0.029, OR 0.343, 95 %CI 0.127–0.926) and OPN rs1126772 revealed associations with tumor–node–metastasis (TNM) stage (P = 0.025, OR 1.765, 95 % CI 1.073–2.905) and tumor differentiation (P = 0.031, OR 1.722, 95 % CI 1.049–2.825). OPN expression was observed in 133 of the 243 cases (54.7 %) by IHC and was correlated with serosa invasion (P = 0.013), TNM stage (P = 0.003) and lymph node metastasis (P = 0.002). CD44 expression was found in 92 of the 243 cases (37.9 %) and was associated with tumor size (P = 0.005) and lymph node metastasis (P = 0.023), respectively. The OPN expression displayed a positive association with CD44 (P = 0.01, r _s = 0.164).

Conclusions

We found that the polymorphisms rs4754, rs9138 and rs1126772 of OPN gene and rs353639 of CD44 gene were significantly associated with gastric cancer. Our IHC data indicated that interaction of OPN and CD44 protein would promote progression and metastasis of gastric cancer.     

Chimeric 5/35 adenovirus-mediated Dickkopf-1 overexpression suppressed tumorigenicity of CD44+ gastric cancer cells via attenuating Wnt signaling

Background

Gastric cancer stem cells (CSCs), which require activation of Wnt signaling to maintain their self-renewal and tumorigenicity, are proposed to be critical targets for effective therapy of gastric carcinomas. Gene therapies that are delivered by adenovirus of serotype 5 (Ad5) or chimeric 5/35(Ad5/35) adenovirus have shown promise for treating various cancers. Here we aimed to develop a gene therapy strategy that targeted gastric CSCs (CD44⁺ cells).

Methods

CD44⁺ cells were isolated by fluorescence activated cell sorting from both primary gastric cancer cells and cell lines. Expression of adenovirus receptors was examined in CD44⁺ and CD44^? cells. A potent Wnt antagonist Dickkopf-1 (DKK1) was delivered into CD44⁺ cells using Ad5/35 (Ad5/35-DKK1). The therapeutic outcomes were evaluated.

Results

Expression of Coxsakievirus adenovirus receptor for Ad5 was significantly reduced, while abundance of CD46, the receptor for Ad5/35, was slightly higher in CD44⁺ cells. Accordingly, CD44⁺ cells were sensitive to Ad5/35 infection, but not to Ad5. Ad5/35-DKK1 introduced DKK1 into CD44⁺ cells and deactivated endogenous Wnt/β-catenin signaling efficiently. Overexpression of DKK1 inhibited survival, anchorage-independent colony formation, and invasion of CD44⁺ cells, which were restored by a GSK-3 specific inhibitor BIO-acetoxime. More importantly, introduction of DKK1 abrogated the tumorigenicity of CD44⁺ cells in vivo. However, Ad5/35-DKK1 only showed minimal cytotoxicity to normal tissue-derived cells, L-02 and GES-1.

Conclusions

We developed, for the first time, a novel Ad5/35-DKK1-based approach to abrogate Wnt signaling in CSCs and demonstrated that gastric CSC-targeting gene therapy was effective in preclinical experiments.     

FAK, CD44v6, c-Met and EGFR in colorectal cancer parameters: tumour progression, metastasis, patient survival and receptor crosstalk

Purpose

Research for reliable and patient-specific markers in colorectal cancer (CRC) is based on solid evidence that staging alone is not informative enough. Employing four cellular receptors, we embarked to identify aggressive tumour behaviour and impact of surrogate marker expression on patient prognosis.

Methods

One-hundred eighty-three CRC patients were enrolled in our investigation that focused on an array of biological markers, namely epidermal growth factor receptor (EGFR), c-Met, focal adhesion kinase (FAK) and CD44v6. Tissue samples, clinicopathological data and patient’s follow-up information were collected, and immunohistochemical assays evaluated the levels of the aforementioned molecules. All available data were correlated with tumour grade, stage, patient age, gender and survival.

Results

Expression of all receptors correlated closely with tumour stage (P?<?0.01) exhibiting a connection with cancer’s invasiveness and progress. Survival also proved to depend significantly on molecular expression (log-rank test for Kaplan–Meier; EGFR P?=?0.030, c-Met P?=?0.050, FAK P?<?0.001, CD44v6 P?<?0.001). Stage, FAK and CD44v6 emerged as independent predictors of survival in a stepwise regression analysis (FAK P?=?0.001 Exp(B)?=?2.517, 95 % confidence interval (CI)?=?1.704–5.831 and CD44v6 P?=?0.005, Exp(B)?=?2.299, 95 % CI?=?1.287–4.110). T-stage, nodal metastasis, all metastatic types (N/M) and size correlated with at least one of the receptors or their co-expression. Notably, increased staining for each receptor was followed by statistically significant expression elevation of at least one of the other markers.

Conclusions

Our results suggest that the selected cellular receptors are suitable for use as biomarkers of survival and tumour progression in CRC. Furthermore, we provide additional evidence for receptor interaction, properly clarifying their importance, which could potentially lead to more effective anti-CRC regimens.     

Differential Expression and Significance of Endoplasmic Reticulum Golgi Intermediate Compartment 1 in Precancerous Gastric Lesions and Gastric Cancer

Background

We investigated the expression of endoplasmic reticulum Golgi intermediate compartment 1 (ERGIC1) in precancerous gastric lesions and gastric cancer and the function of ERGIC in human gastric cancer cell lines.

siRNA-participated chemotherapy: an efficient and specific therapeutic against gastric cancer

Purpose

This study aims to investigate the role of siRNA silencing fibroblast growth factor receptor (FGFR) expression in promoting chemotherapy effect of gastric cancer and to explore its mechanism.

Methods

Human gastric cancer cells MGC80-3 were divided into four groups: control group, cisplatin group (2 μg/L), cisplatin (2 μg/L) + siRNA group and siRNA group. The expressions of FGFR in four groups were detected by immunofluorescence. The cell proliferation and apoptosis were detected by MTT assay and flow cytometry. The protein expression levels of vascular endothelial growth factor receptor (VEGFR), caspase-3 and Bax were detected by Western blot. Further, animal model of gastric cancer was established and divided into four groups as in vitro experiment. The expression of FGFR mRNA in tumor tissue was detected by the real-time fluorescence quantitative polymerase chain reaction. The size of tumor was measured to analyze the effects of treatment. Histopathological detections were performed by hematoxylin and eosin staining and immunohistochemistry.

Results

For in vitro experiment, significant decrease inFGFR expression, inhibition of proliferation and promotion of apoptosis were observed in siRNA-treated cells, so as cisplatin group. siRNA also resulted in the reduction of VEGFR and rise in apoptosis-related protein (caspase-3). As for the experiment in vivo, siRNA also suppressed the expression of FGFR and enhanced tumor shrink. Furthermore, the co-administration of siRNA and cisplatin revealed a more excellent antitumor effect than other therapies.

Conclusions

siRNA can effectively suppress FGFR expression and cell proliferation, but promote apoptosis in vitro and also inhibit tumor growth and FGFR production in vivo. siRNA-participated chemotherapy may provide an efficient therapeutic approach to treat gastric cancer.