Metallopanstimulin-1 regulates invasion and migration of gastric cancer cells partially through integrin ß4.

MPS-1 (metallopanstimulin-1), also known as ribosomal protein S27, was overexpressed in gastric cancer cells. However, how MPS-1 contributes to gastric carcinogenesis has not been well characterized. Here, we show that high expression of MPS-1 was observed in gastric cancer tissues and associated with gastric cancer cell metastasis. Alteration of MPS-1 expression regulates invasion and migration of gastric cancer cells both in vitro and in vivo. Furthermore, by using Signal-Net and cluster analyses of microarray data we identified integrin ß4 (ITGB4) as a downstream target of MPS-1 that mediates its effects on cell metastasis. Knockdown of MPS-1 expression in gastric cancer cells led to significant reduction of ITGB4 expression at both the RNA and protein levels. Mechanically, we found that overexpression of ITGB4 in MPS-1 knockdown cells largely recovers the ability of invasion and migration. Conversely, knockdown of ITGB4 partially reduced cell invading/migrating ability induced by MPS-1 overexpression. Moreover, MPS-1 and ITGB4 expressions are positively correlated in gastric cancer cell lines and tissues. Finally, the survival analyses show that the expression of MPS-1 and ITGB4 is associated with poor outcomes in gastric cancer patients. Collectively, our findings suggest that MPS-1 regulates cell invasiveness and migration partially through ITGB4 and that MPS-1/ITGB4 signaling axis may serve as therapeutic targets in the treatment of gastric cancer.

Knockdown of metallopanstimulin-1 inhibits NF-κB signaling at different levels: the role of apoptosis induction of gastric cancer cells.

The ribosomal protein S27 (metallopanstimulin-1, MPS-1) has been reported to be a multifunctional protein, with increased expression in a number of cancers. We reported previously that MPS-1 was highly expressed in human gastric cancer. Knockdown of MPS-1 led to spontaneous apoptosis and repressed proliferation of human gastric cancer cells in vitro and in vivo. However, how does MPS-1 regulate these processes is unclear. Here we performed microarray and pathway analyses to investigate possible pathways involved in MPS-1 knockdown-induced apoptosis in gastric cancer cells. Our results showed that knockdown of MPS-1 inhibited NF-κB activity by reducing phosphorylation of p65 at Ser536 and IκBα at Ser32, inhibiting NF-κB nuclear translocation, and down-regulating its DNA binding activity. Furthermore, data-mining the Gene-Regulatory-Network revealed that growth arrest DNA damage inducible gene 45ß (Gadd45ß), a direct NF-κB target gene, played a critical role in MPS-1 knockdown-induced apoptosis. Over-expression of Gadd45ß inhibited MPS-1 knockdown-induced apoptosis via inhibition of JNK phosphorylation. Taken together, these data revealed a novel pathway, the MPS-1/NF-κB/Gadd45ß signal pathway, played an important role in MPS-1 knockdown-induced apoptosis of gastric cancer cells. This study sheds new light on the role of MPS-1/NF-κB in apoptosis and the possible use of MPS-1 targeting strategy in the treatment of gastric cancer.

Helicobacter pylori induces promoter hypermethylation and downregulates gene expression of IRX1 transcription factor on human gastric mucosa.

BACKGROUND AND AIM: Gene silence of IRX1 tumor suppressor by promoter CpG methylation combined with loss of heterozygosity (LOH) has been identified in human gastric cancer. This study investigated the association between methylation of IRX1 and Helicobacter pylori infection in gastric mucosa tissues and cell line. METHODS: IRX1 methylation was studied by methylation specific polymerase chain reaction (MSP) and bisulfate sequencing polymerase chain reaction (BSP) methods in gastric mucosa tissues from H. pylori-positive chronic gastritis patients or H. pylori-negative chronic gastritis patients. Promoter activity, methylation status and gene expressing level of IRX1 were evaluated by persistent infecting H. pylori on human gastric cells GES-1 in vitro. Electron microscopy was used to observe the effect of H. pylori infection on GES-1 gastric mucosa cells. RESULTS: The methylation level of IRX1 promoter in H. pylori positive chronic gastritis and H. pylori negative chronic gastritis was 55.30%±13.17 versus 5.20%±6.31, respectively (P<0.01). H. pylori infection stimulated increased microvillus, and mucous secretion on GES-1 cells. Infection of H. pylori induced IRX1 promoter methylation and downregulation of the promoter activity as well as gene expression significantly. CONCLUSIONS: This study firstly demonstrated that H. pylori infection contributes to IRX1 promoter methylation on gastric mucosa.

Cell cycle dependent genes from the gastric cancer cell MKN45 can affect tumorigenesis.

BACKGROUND/AIMS: To investigate the cell cycle dependent genes involved in gastric tumorigenesis, possibly determining the relationship between the cell cycle and tumorigenesis. METHODOLOGY: MKN45 cells were collected every hour from Oh to 12h after release from G2/M and G1/S blocks. Nine samples (a-i), chosen at key times of the cell cycle, were prepared for RNA isolation and cDNA microarray analysis. RESULTS: In 2001 viable clones, 959 genes showed periodic variations during the cell cycle. Among 2001 genes that were clustered, a series of up-regulated genes were assigned to different cell cycle phases. Many periodically dependent genes in the cell cycle were ubiquitously expressed and participated in various cell physiological functions, such as transcription, translation, ubiquitination and signal transduction. These cell cycle dependent genes could affect cancer cell proliferation, apoptosis, activation of oncogenes and inactivation of tumor suppressor genes. CONCLUSIONS: We provided a comprehensive understanding of the gene expression profile involved in gastric cancer cell cycles and laid a foundation for further research on mechanisms of gastric tumorigenesis.

Comparative proteomics analysis of human gastric cancer.

AIM: To isolate and identify differentially expressed proteins between cancer and normal tissues of gastric cancer by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). METHODS: Soluble fraction proteins of gastric cancer tissues and paired normal tissues were separated by 2-DE. The differentially expressed proteins were selected and identified by MALDI-TOF-MS and database search. RESULTS: 2-DE profiles with high resolution and reproducibility were obtained. Twenty-three protein spots were excised from sliver staining gel and digested in gel by trypsin, in which fifteen protein spots were identified successfully. Among the identified proteins, there were ten over-expressed and five under-expressed proteins in stomach cancer tissues compared with normal tissues. CONCLUSION: In this study, the well-resolved, reproducible 2-DE patterns of human gastric cancer tissue and paired normal tissue were established and optimized and certain differentially-expressed proteins were identified. The combined use of 2-DE and MS provides an effective approach to screen for potential tumor markers.

In vitro and in vivo evidence of metallopanstimulin-1 in gastric cancer progression and tumorigenicity.

PURPOSE: The metallopanstimulin-1 (MPS-1) gene is a growth factor-inducible gene, which is highly expressed in many human cancers and may be involved in the progression towards tumor malignancy. However, it is unclear whether MPS-1 plays any role in gastric cancer development or progression. Our studies were designed to clarify the MPS-1 expression pattern and to explore its potential role in gastric cancer. EXPERIMENTAL DESIGN: The expression pattern of MPS-1 was determined in primary gastric cancer specimens and gastric cancer cell lines via immunohistochemistry and Western blotting. To investigate the functional significance of MPS-1 expression, three small interfering RNA (siRNA) expression plasmids were constructed and transfected into gastric cancer cell line SGC7901. The stable cell lines transfected with the siRNA targeting MPS-1 mRNA plasmids were selected and the biological features of these cells were examined. RESULTS: MPS-1 was overexpressed in 86% of the gastric cancer tissues and all gastric cancer cells. In addition, MPS-1 expression was significantly increased and corresponded with the tumor-node-metastasis clinical stage, and was significantly higher in the late stage (P < 0.01). The MPS-1 expression level was significantly decreased in the transfected cells with MPS-1-specific siRNA expression plasmid pRNAT-133. Furthermore, the stable transfected cancer cells exhibited an increase in the incidence of spontaneous apoptosis and a decrease in growth ability and tumorigenicity in nude mice. CONCLUSIONS: These results provide strong evidence that MPS-1 plays an important role in gastric cancer cell proliferation and development, and suggests that MPS-1 is a promising target for gastric cancer treatment.

Targeting hepatitis B virus antigens to dendritic cells by heat shock protein to improve DNA vaccine potency.

AIM: To investigate a novel DNA vaccination based upon expression of the HBV e antigen fused to a heat shock protein (HSP) as a strategy to enhance DNA vaccine potency. METHODS: A pCMV-HBeAg-HSP DNA vaccine and a control DNA vaccine were generated. Mice were immunized with these different construct. Immune responses were measured 2 wk after a second immunization by a T cell response assay, CTL cytotoxicity assay, and an antibody assay in C57BL/6 and BALB/c mice. CT26-HBeAg tumor cell challenge test in vivo was performed in BALB/c mice to monitor anti-tumor immune responses. RESULTS: In the mice immunized with pCMV-HBe-HSP DNA, superior CTL activity to target HBV-positive target cells was observed in comparison with mice immunized with pCMV-HBeAg (44% +/- 5% vs 30% +/- 6% in E:T > 50:1, P < 0.05). ELISPOT assays showed a stronger T-cell response from mice immunized with pCMV-HBe-HSP than that from pCMV-HBeAg immunized animals when stimulated either with MHC class I or class II epitopes derived from HBeAg (74% +/- 9% vs 31% +/- 6%, P < 0.01). ELISA assays revealed an enhanced HBeAg antibody response from mice immunized with pCMV-HBe-HSP than from those immunized with pCMV-HBeAg. The lowest tumor incidence and the slowest tumor growth were observed in mice immunized with pCMV-HBe-HSP when challenged with CT26-HBeAg. CONCLUSION: The results of this study demonstrate a broad enhancement of antigen-specific CD4+ helper, CD8+ cytotoxic T-cell, and B-cell responses by a novel DNA vaccination strategy. They also proved a stronger antigen-specific immune memory, which may be superior to currently described HBV DNA vaccination strategies for the treatment of chronic HBV infection.

Inhibition of the proliferation of human gastric cancer cells SGC-7901 in vitro and in vivo using Bcl-2 siRNA.

BACKGROUND: Bcl-2, the anti-apoptotic protein is overexpressed in the majority of gastric cancers and associated with its pathogenesis. To better understanding of the role of Bcl-2, RNA interference (RNAi) was used to inhibit Bcl-2 expression in the human gastric cancer cells in vitro and in vivo. METHODS: Bcl-2 small interfering RNA (siRNA) was transfected into human gastric cancer cells SGC-7901, and Bcl-2 expression was monitored by real-time polymerase chain reaction (PCR) and Western blot. Cell proliferation, apoptosis, and telomerase activity were examined by MTT, flow cytometry, and TRAP assay, respectively. Gastric cancer cells treated with 100 nmol/L Bcl-2 siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed. RESULTS: Bcl-2 siRNA significantly inhibited the expression of Bcl-2 in human gastric cancer cells at both mRNA and protein levels in a time- and dose-dependent manner. Bcl-2 siRNA also decreased telomerase activity (by 78.76%) and increased the rate of apoptosis (by 37.47%). SGC-7901 cell growth was also significantly suppressed in vivo and in vitro. CONCLUSIONS: Bcl-2 expression knockdown suppressed the growth of gastric cancer cells. Thus, Bcl-2 may play a very important role in carcinogenesis of gastric cancer and its knockdown may offer a new potential gene therapy approach for human gastric cancer in future.

Long noncoding RNA UCA1 promotes tumour metastasis by inducing GRK2 degradation in gastric cancer.

Increasing evidence demonstrates that long noncoding RNAs (lncRNAs) regulate gene and protein expression by exerting an influence on transcriptional and post-transcriptional processes. Here, we report that the lncRNA UCA1 increases the metastatic ability of gastric cancer (GC) cells by regulating GRK2 protein stability by promoting Cbl-c-mediated GRK2 ubiquitination and degradation. This process then activates the ERK-MMP9 signalling pathway. Furthermore, we demonstrate that GRK2 is downregulated in GC cells and that silencing of GRK2 might cause similar phenotypic changes and signalling pathway activation as those induced by elevated UCA1 in GC cells. Our results suggest that UCA1 might function as a mediator of protein ubiquitination and may be a promising molecular target for GC therapy.

TET1 inhibits gastric cancer growth and metastasis by PTEN demethylation and re-expression.

Ten-Eleven Translocation 1 (TET1) is a member of ten eleven translocation enzymes, which convert 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC). TET1 can promote CpG islands demethylation in specific genes and often absent in various cancers. Herein, we found that TET1 expression and 5-hmC content were low in gastric tumors compared to its adjacent non-tumor tissues. Cell proliferation, migration and invasion were enhanced upon TET1 knockdown in gastric cancer cells in vitro. This phenomenon was confirmed by an animal xeongraft model. We also found that TET1 directly binds to the promoter region of PTEN and activates its transcription through demethylation of CpG islands. TET1 knockdown activated AKT and FAK pathways, which were suppressed by PTEN. The activation of AKT and FAK facilitated tumor migration, invasion and accelerated cell growth. In conclusion, we found a novel mechanism that TET1 suppresses tumor cell growth, migration and invasion through demethylation of CpG island in PTEN promoter by increasing 5-hmC content. The re-expressed PTEN subsequently down regulates AKT and FAK activity.

Clinicopathological correlation of keratinocyte growth factor and matrix metalloproteinase-9 expression in human gastric cancer.

AIMS AND BACKGROUND: Keratinocyte growth factor (KGF) is reported to be implicated in the growth of some cancer cells. Matrix metalloproteinase 9 (MMP-9) is thought to enhance the tumor invasion and metastasis ability. This study was aimed at analyzing the relationship between KGF and MMP-9 expression and patients' clinicopathological characteristics to clarify the clinical significance of the expression of KGF and MMP-9 in gastric cancer. METHODS: Tissue samples from 161 patients with primary gastric cancer were investigated using immunohistochemistry. The relationship between KGF and/or MMP-9 expression and clinicopathological characteristics was analyzed. RESULTS: KGF expression and MMP-9 expression in gastric cancer tissue were observed in 62 cases (38.5%) and 97 cases (60.2%), respectively. MMP-9 was significantly associated with depth of invasion, lymph node metastasis and TNM stage. The prognosis of MMP-9-positive patients was significantly poorer than that of MMP-9-negative patients (p = 0.009). KGF expression was positively correlated with MMP-9 expression in gastric cancer, and the prognosis of patients with both KGF- and MMP-9-positive tumors was significantly worse than that of patients with negative tumors for either factor (p = 0.045). Expression of MMP-9 was revealed to be an independent prognostic factor (p = 0.026). CONCLUSIONS: Coexpression of KGF and MMP-9 in gastric cancer could be a useful prognostic factor, and MMP-9 might also serve as a novel target for both prognostic prediction and therapeutics.

TK gene combined with mIL-2 and mGM-CSF genes in treatment of gastric cancer.

AIM: Cancer gene therapy has received more and more attentions in the recent decade. Various systems of gene therapy for cancer have been developed. One of the most promising choices is the suicide gene. The product of thymidine kinase (TK) gene can convert ganciclovir (GCV) to phosphorylated GCV, which inhibits the synthesis of cell DNA, and then induces the cells to death. Cytokines play an important role in anti-tumor immunity. This experiment was designed to combine the TK gene and mIL-2/mGM-CSF genes to treat gastric cancer, and was expected to produce a marked anti-tumor effect. METHODS: TK gene was constructed into the retroviral vector pLxSN, and the mIL-2 and mGM-CSF genes were inserted into the eukaryotic expressing vector pIRES. The gastric cancer cells were transfected by retroviral serum that was harvested from the package cells. In vitro study, the transfected gastric cancer cells were maintained in the GCV- contained medium, to assay the cell killing effect and bystander effect. In vivo experiment, retroviral serum and cytokines plasmid were transfected into tumor-bearing mice, to observe the changes of tumor volumes and survival of the mice. RESULTS: In vitro experiment, 20 % TK gene transduced cells could cause 70-80 % of total cells to death. In vivo results showed that there was no treatment effect in control group and TK/GCV could inhibit the tumor growth. The strongest anti-tumor effect was shown in TK+mIL-2+mGM-CSF group. The pathologic examination showed necrosis of the cancer in the treated groups. CONCLUSION: TK/GCV can kill tumor cells and inhibit the tumor growth in vivo. IL-2 and GM-CSF strongly enhance the anti-tumor effect. Through the retrovirus and liposome methods, the suicide gene and cytokine genes are all expressed in the tissues.

Antitumor effects of vaccine consisting of dendritic cells pulsed with tumor RNA from gastric cancer.

AIM: To investigate the immunotherapeutic potential of vaccine consisting of dendritic cells (DCs) pulsed with total RNA from MFC gastric cancer cells. METHODS: DCs were prepared from the spleens of strain 615 mice by magnetic cell sorting (MACS). After culture for 24 h, DCs were pulsed with total RNA from MFC gastric cancer cells. Mice of one group were immunized with tumor RNA pulsed DC (RNA/DC) at the dosage of 1X10(6) on d 14 and 7 by s c inoculation before tumor implantation. Mice of another group were immunized with unpulsed DC (UDC) at the same dosage on days as the RNA/DC group. The third group of control mice was untreated. On d 0, all the mice were challenged with s c injections of 5X10(5) MFC gastric cancer cells. After inoculation, the mice were monitored closely with respect to tumor growth. Activities of NK cells in PBL and splenocytes and CTL were tested. RESULTS: On d 21 after tumor cell inoculation, the mice of control group manifested the largest tumors with volume at a mean of 2.6323+/-1.1435 cm(3), followed by the UDC and RNA/DC groups with mean volumes at 0.7536+/-0.3659 cm(3) and 0.3688+/-0.6571 cm(3), respectively. The activities of NK cells in PBL and splenocytes in RNA/DC group were 66.2% and 65.4%, respectively, higher than that in the control group. The tumor specific CTL activity in RNA/DC group was 49.5%, higher than that in the control group. CONCLUSION: The tumor vaccine with DCs pulsed with total RNA from gastric cancer cells possesses the ability to stimulate tumor specific CTL activity and to establish anti-tumor immunity when administered in vivo.

Androgen receptor promotes gastric cancer cell migration and invasion via AKT-phosphorylation dependent upregulation of matrix metalloproteinase 9.

Androgen receptor (AR) plays an important role in many kinds of cancers. However, the molecular mechanisms of AR in gastric cancer (GC) are poorly characterized. Here, we investigated the role of AR in GC cell migration, invasion and metastatic potential. Our data showed that AR expression was positively correlated with lymph node metastasis and late TNM stages. These findings were accompanied by activation of AKT and upregulation of matrix metalloproteinase 9 (MMP9). AR overexpression induced increases in GC cell migration, invasion and proliferation in vitro and in vivo. These effects were attenuated by inhibition of AKT, AR and MMP9. AR overexpression upregulated MMP9 protein levels, whereas this effect was counteracted by AR siRNA. Inhibition of AKT by siRNA or an inhibitor (MK-2206 2HC) decreased AR protein expression in both stably transfected and parental SGC-7901 cells. Luciferase reporter and chromatin immunoprecipitation assays demonstrated that AR bound to the AR-binding sites of the MMP9 promoter. In summary, AR overexpression induced by AKT phosphorylation upregulated MMP9 by binding to its promoter region to promote gastric carcinogenesis. The AKT/AR/MMP9 pathway plays an important role in GC metastasis and may be a novel therapeutic target for GC treatment.

Upregulated expression of LOX is a novel independent prognostic marker of worse outcome in gastric cancer patients after curative surgery.

Lysyl oxidase (LOX) initiates the enzymatic stage of collagen and elastin cross-linking. It also has intracellular functions involved in the regulation of cell differentiation, motility/migration and gene transcription. Aberrant expression of the LOX gene has been reported in multiple tumors. However, the correlation of its expression with clinicopathological parameters and its prognostic significance in gastric cancer remains largely unknown. In order to address this problem, total RNA of paired tissue samples (n=10) and a tissue microarray containing 161 paired tissues from patients with gastric cancers at different stages were collected. Quantitative real-time PCR and immunochemistry assay were conducted to investigate the expression of LOX. Based on the results, LOX mRNA was increased in gastric cancer tissues compared with the adjacent normal mucosa. Immunohistochemical detection revealed that expression of LOX was associated with depth of tumor invasion (P<0.05), lymph node status (P<0.05), TNM stage (P<0.05) and survival (P<0.05). Cox regression analysis revealed that positive expression of LOX (P=0.026) was an independent prognostic marker for survival in patients with gastric cancer.

RhoGDI2 confers resistance to 5-fluorouracil in human gastric cancer cells.

Resistance to 5-fluorouracil (5-FU) in patients with gastric cancer is a serious therapeutic problem and major efforts are underway to understand the underlying mechanisms. We have previously identified RhoGDI2 as a contributor to 5-FU resistance in colon cancer cells using 2D electrophoresis and mass spectrometry and the current study aimed to further investigate this role. The expression of RhoGDI2 in seven gastric cancer cell lines was positively correlated with resistance to 5-FU. Lower 5-FU sensitivity of isolated tumor cells from patients with gastric cancer was also associated with higher RhoGDI2 expression. Ectopic expression of RhoGDI2 in gastric cancer cells increased the resistance to 5-FU and reverted low dose 5-FU-induced G2/M phase arrest without affecting the population of sub-G1 cells. Overall, these findings suggest that RhoGDI2 is associated with 5-FU resistance and is a potential therapeutic target for enhancing chemotherapy efficacy in gastric cancer.

microrna expression signature of gastric cancer cells relative to normal gastric mucosa.

micrornas (miRNAs) play an important role in a wide range of physiological and developmental processes by negatively regulating the expression of target genes at the post-transcriptional level. In this study, we investigated the differential miRNA expression signature between gastric cancer cells and normal gastric mucosa to determine changes in miRNA expression during gastric cancer development. We analyzed the global miRNA expression profiles of 9 gastric cancer cell lines and 6 normal gastric mucosa lines using miRNA microarrays. In addition, we performed quantitative real-time PCR (Q-PCR) to validate the results. Correlations between the miRNA expression profile and tumor clinicopathological parameters were analyzed. We found that 17 miRNAs were upregulated in gastric cancer cell lines and 146 miRNAs were downregulated compared to normal gastric mucosa. Using microarray data and Q-PCR validation, 15 miRNAs were finally selected. These candidate miRNAs were associated with gastric cancer clinicopathology to various degrees. High expression levels of hsa-miR-93 were found to predict poor survival (median, 16 vs. 40 months; log-rank test p<0.05). These findings suggest that miRNAs play vital roles in human gastric cancer. The findings may also provide clues toward understanding the molecular functions of miRNAs in various biological processes.

Salinomycin can effectively kill ALDH(high) stem-like cells on gastric cancer.

Salinomycin is a novel identified cancer stem cells (CSCs) killer. Higher ALDH activity represents CSCs characterization. Here, we screened ALDH activities on several gastric cancer cell lines and divided them into ALDH(high) and ALDH(low) gastric cancer groups. ALDH(high) cancer cells (NCI-N87 and SNU-1) disclosed more CSCs characteristics, such as higher levels of Sox2, Nanog and Nestin, more floating spheroid bodies, more colony formation and more resistance to conventional chemotherapeutic drugs 5-Fu and CDDP, compared to these parameters observed in ALDH(low) cancer cells (P<0.01). Importantly, ALDH(high) cancer cells are relatively sensitive to salinomycin when compared to ALDH(low) cancer cells (P<0.01). Our results confirmed ALDH as functional marker of CSCs population on gastric cancer. Salinomycin might be selective therapy for CSCs fraction, which is resistant to conventional anticancer drugs 5-Fu and CDDP.

Silencing invariant chains of dendritic cells enhances anti-tumor immunity using small-interfering RNA.

BACKGROUND: Genetic modification of dendritic cells (DCs) has been used as an effective approach to enhance anti-tumor immunity. RNA interference (RNAi), which can cause the degradation of any RNA in a sequence-specific manner, is a post-transcriptional gene silencing mechanism. In this study, small-interfering RNA (siRNA) specific for the Ii gene was transfected into DCs, and the anti-tumor immunity of Ii-silenced DCs was assessed. METHODS: The silencing effect of siRNA was evaluated by Western blotting and real-time PCR analyses. In vitro cytotoxic activity of T cells was evaluated using a Cytotox 96(®) non-radioactive cytotoxicity assay kit. The time to tumor onset and the tumor volumes were used as reliable indices to assess the anti-tumor immunity in vivo. To further examine the mechanisms underlying the anti-tumor immunity, flow cytometry analysis was used. RESULTS: The Ii expression of DCs was significantly reduced after Ii siRNA transfection. Significant in vitro anti-tumor ability was exhibited when DCs were co-transfected with Ii siRNA plus endogenous tumor antigen (P < 0.05). Furthermore, tumor growth was greatly inhibited when mice were immunized with DCs transfected with Ii siRNA plus tumor antigen prior to or subsequent to tumor implantation. Flow cytometry analysis in vitro and in vivo indicated that both CD4(+) and CD8(+) T cells were significantly activated in the Ii siRNA group (P < 0.05). CONCLUSION: Silencing of the Ii gene of DCs may offer a potential approach to enhance DC-based anti-tumor immunity.

[Preparation of PHF10 antibody and analysis of PHF10 expression gastric cancer tissues].

AIM: To prepare PHF10 antibody and check the expression of PHF10 protein in the tissues of gastric cancer and adjacent tissue. METHODS: His-tagged PHF10 was expressed in E.coli BL21. Rabbit PHF10 polyclonal antiserum was generated by injecting the purified recombinant His-tagged PHF10 inclusion body as the antigen, and further separated by affinity purification. To confirm the specificity of the PHF10 antibody, transiently expressed Flag-PHF10 fusion protein was analyzed by immunoblotting with anti-flag monoclonal antibody control. The produced antibody Was used to check the expression of PHF10 protein in gastric cancer and adjacent tissues by Western blot. RESULTS: Antibodies specifically binding to PHF10 could be obtained by immunization, and expression of PHF10 was significantly higher in gastric cancerous tissues comparing with adjacent normal tissues and GES-1 shows more PHF10 expression than gastric cancer cell lines with the generated antibody. CONCLUSION: The specific anti-PHF10 antibody is obtained and it could be used to detect the expression of PHF10 protein in gastric cancer cell lines and tissues, in which PHF10 is unregulated in gastric cancer.