Exosomes and Nanoengineering: A Match Made for Precision Therapeutics

Targeted exosomal delivery systems for precision nanomedicine attract wide interest across areas of molecular cell biology, pharmaceutical sciences, and nanoengineering. Exosomes are naturally derived 50-150 nm nanovesicles that play important roles in cell-to-cell and/or cell-to-tissue communications and cross-species communication. Exosomes are also a promising class of novel drug delivery vehicles owing to their ability to shield their payload from chemical and enzymatic degradations as well as to evade recognition by and subsequent removal by the immune system. Combined with a new class of affinity ligands known as aptamers or chemical antibodies, molecularly targeted exosomes are poised to become the next generation of smartly engineered nanovesicles for precision medicine. Here, recent advances in targeted exosomal delivery systems engineered by aptamer for future strategies to promote human health using this class of human-derived nanovesicles are summarized.

A Detailed Protein-SELEX Protocol Allowing Visual Assessments of Individual Steps for a High Success Rate

As a nucleic acid alternative to traditional antibody, aptamer holds great potential in various fields of biology and medicine such as targeted gene therapy, drug delivery, bio-sensing, and laboratory medicine. Over the past decades, the conventional Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method has undergone dramatic modifications and improvements owing to developments in material sciences and analytical techniques. However, many of the recently developed strategies either require complex materials and instruments or suffer from low efficiency and high failure rates in the selection of desired aptamers. Accordingly, the development of aptamers against new or novel targets is still a major obstacle for aptamer-based research and application. Here, an improved protein-SELEX procedure is presented for simplified and highly efficient isolation of aptamers against protein targets. Approaches are described that ensure a high success rate in aptamer selection by simplifying polymerase chain reaction procedures, introducing denature gel, utilizing an electro-elution-based single-stranded DNA separation strategy, as well as an enzyme-linked immunosorbent assay-based highly sensitive binding assay. In addition, a simplified sample preparation method for MiSeq-based next-generation sequencing is also introduced. While a recombinant protein as a bait protein for SELEX is discussed here, this protocol will also be invaluable for researchers wishing to develop aptamers against targets other than proteins such as small molecules, lipids, carbohydrates, cells, and micro-organisms for future gene therapy and/or diagnostics.

Aptamer-guided extracellular vesicle theranostics in oncology

In the past decade, the study of exosomes, nanosized vesicles (50-150 nm) released into the extracellular space via the fusion of multivesicular bodies with the plasma membrane, has burgeoned with impressive achievements in theranostics applications. These nanosized vesicles have emerged as key players in homeostasis and in the pathogenesis of diseases owing to the variety of the cargos they can carry, the nature of the molecules packaged inside the vesicles, and the robust interactions between exosomes and target cells or tissues. Accordingly, the development of exosome-based liquid biopsy techniques for early disease detection and for monitoring disease progression marks a new era of precision medicine in the 21st century. Moreover, exosomes possess intrinsic properties - a nanosized structure and unique "homing effects" - that make them outstanding drug delivery vehicles. In addition, targeted exosome-based drug delivery systems can be further optimized using active targeting ligands such as nucleic acid aptamers. Indeed, the aptamers themselves can function as therapeutic and/or diagnostic tools based on their attributes of unique target-binding and non-immunogenicity. This review aims to provide readers with a current picture of the research on exosomes and aptamers and their applications in cancer theranostics, highlighting recent advances in their transition from the bench to the clinic.

Effect of RhoC silencing on multiple myeloma xenografts and angiogenesis in nude mice

In this study, we investigated the expression of RhoC in the multiple myeloma (MM) cell line RPMI- 8226, as well as the effects of silencing RhoC on the growth of tumor xenografts and tumor-induced angiogenesis in nude mice with MM. For this purpose, we transduced RPMI-8226 cells with lentiviral particles overexpressing short hairpin RNAs (shRNA) targeting RhoC. Tumor xenografts were generated by subcutaneously injecting nude mice with RPMI-8226 cells overexpressing control shRNA [negative control (NC) group] or the RhoC shRNA [the experimental (S) group], respectively. RhoC protein and mRNA levels in the tumor xenografts were measured. Nude mice were also subcutaneously inoculated with Matrigel mixed with vascular endothelial growth factor, and CD31 and KI67 levels in the tumor xenografts were measured by immunohistochemistry. Similarly, we assessed tumor xenograft growth and angiogenesis in Matrigel implants in the mice of both groups. We found that RhoC levels, microvessel density, and CD31 labeling index were more reduced in the S group than in the NC group. However, there was no significant difference in the size of tumor xenografts between the 2 groups. The number of new vessels and the neovascular length in the Matrigel implants were significantly lower in the S group than in the NC group. Therefore, we concluded that RhoC expression in myeloma xenografts has important effects on the induction of angiogenesis.

Effects of RhoC downregulation on the angiogenesis characteristics of myeloma vascular endothelial cells

Background

Tumor angiogenesis plays an important role in disease progression, and RhoC has been previously found to be expressed in vascular endothelial cells (VECs); however, its role in tumor angiogenesis requires clarification. This study aimed to explore the effects of RhoC downregulation on the cytoskeleton, pseudopod formation, migration ability, and canalization capacity of myeloma vascular endothelial cells (MVECs) in vitro.

Materials and methods

The expression of RhoC in MVECs and human umbilical vein endothelial cells (HUVECs) was knocked down by shRNA, and the expression levels of RhoC mRNA were detected by quantitative reverse transcription polymerase chain reaction (qRT‐PCR). The cytoskeletal changes and pseudopods were observed by laser scanning confocal and scanning electron microscopy; VECs were incubated in two‐dimensional Matrigel and three‐dimensional microcarriers to observe tube‐like structures and budding status, respectively. The protein expression of RhoC, phosphorylation of mitogen‐activated protein kinase (p‐MAPK), and Rho‐associated coiled‐coil kinase (ROCK) was determined by Western blotting. The expression of RhoC in VECs was downregulated by RhoC shRNA, thereby decreasing the number of pseudopods, two‐dimensional tube‐like structures, and buds.

Results

When RhoC was downregulated, the expression levels of ROCK and phosphorylation of MAPK were both decreased (P < 0.05). Moreover, the expression levels of RhoC and phosphorylation of MAPK and three‐dimensional budding numbers were higher in MVECs than in HUVECs (P < 0.05). The downregulation of RhoC expression in MVECs and HUVECs inhibited pseudopod formation, migration, canalization ability, and angiogenesis (P < 0.05).

Conclusion

Our data indicated that MVECs and HUVECs were well suited for angiogenesis research, but the former cell type was shown to be more advantageous in terms of budding numbers. RhoC plays a pivotal role in MVECs angiogenesis, and the downregulation of RhoC expression could inhibit angiogenesis via the RhoC/MAPK and RhoC/ROCK signaling pathways.

CT findings and clinical features of Epstein-Barr virus-associated lymphoepithelioma-like gastric carcinoma

Epstein-Barr virus (EBV)-associated lymphoepithelioma-like gastric carcinoma (LELGC) is a rare primary stomach tumor, which has overlapping imaging features with mass forming gastric carcinoma (GC). The aim of our study was to present the computed tomography (CT) findings and clinical features of EBV-associated LELGC to increase awareness of this entity.The CT findings and clinical features of 4 patients with pathologically documented EBV-associated LELGC were retrospectively analyzed.Among the 4 patients, 3 were male, and 1 was female. The medium age was 51 years old. All cases were single lesions including 1 was in the gastric cardia, 1 was in the gastric body, and 2 were in the gastric antrum. A focal thickening of the gastric wall was conducted, with a large thickness-to-length ratio. The low-density stripe of the normal gastric wall abruptly terminated at the edge of the lesion. The CT images of 4 cases showed inhomogeneous density with the radiodensity values ranging from 25 to 48 HU. In addition, an ulcer was demonstrated with an irregular base and slightly raised borders in all cases. Enhancement after injection of contrast material was heterogeneous enhancement (n = 3) or homogeneous (n = 1). After enhancement, obvious enhancement was seen in 1 case, moderate enhancement was seen in 3 cases, with the peak value of the tumor in the portal phase. No evidence of lymph node involvement and distant invasion was observed.Although LELGC is quite rare, it should be considered in differential diagnosis of early GC, advanced GC, and lymphoma. The relatively typical CT appearance, combined the age and sex of patients, can suggest the diagnosis of LELGC.

Identification of genes associated with cancer progression and prognosis in lung adenocarcinoma: Analyses based on microarray from Oncomine and The Cancer Genome Atlas databases

Background

Lung adenocarcinoma (LUAD) accounts for approximately 40% of all lung cancer patients. There is an urgent need to understand the mechanisms of cancer progression in LUAD and to identify useful biomarkers to predict prognosis.

Methods

In this study, Oncomine database was used to identify potential genes contributed to cancer progression. Bioinformatics analysis including pathway enrichment and text mining was used to explain the potential roles of identified genes in LUAD. The Cancer Genome Atlas database was used to analyze the association of gene expression with survival result.

Results

Our results indicated that 80 genes were significantly dysregulated in LUAD according to four microarrays covering 356 cases of LUAD and 164 cases of normal lung tissues. Twenty genes were consistently and stably dysregulated by more than twofold. Ten of 20 genes had a relationship with overall survival or disease‐free survival in a cohort of 516 LUAD patients, and 19 genes were associated with tumor stage, gender, age, lymph node, or smoking. Low expression of AGER and high expression of CCNB1 were specifically associated with poor survival.

Conclusion

Our findings implicate AGER and CCNB1 might be potential biomarkers for diagnosis and prognosis targets for LUAD.

Effects of tumor-associated macrophages on the proliferation and migration of esophageal cancer-associated lymphatic endothelial cells

The aim of this study was to explore whether M2 macrophages can be transformed into M1 macrophages, and to investigate the effect of different types of macrophages on the proliferation, migration and ring-forming ability of esophageal cancer-related lymphatic endothelial cell (LEC). Human monocytic leukemia cell line (THP-1 cell) was induced to differentiate to M1 macrophages (M1 group) and M2 macrophages (M2 group), and co-cultured with esophageal cancer-associated LEC. The individual esophageal cancer co-cultured with LEC was used as control. Different types of macrophages were observed by Cell counting kit-8 (CCK-8). Enzyme-linked immunosorbent assay (ELISA) was used to detect the VEGF-C concentration; the expression of VEGFR-3 protein and its mRNA was detected by Western blot and qRT-PCR, respectively. The positive rate of the M1 group induced by IFN-γ and LPS was significantly higher than that of M2 macrophages (48.57%5.98% vs 25.83%1.95%). The expression of VEGF-C in the supernatant of the M2 group was higher than that in the control group, but no significant differences regarding the expression of VEGF-C between M1 and control groups were found. In addition, the expression of VEGFR-3 on both mRNA and protein in esophageal cancer-related LEC of the M2 group was significantly higher than those in the control group; however, the M1 group had a significantly lower VEGFR-3 level on both mRNA and protein than the control group. Human M2 macrophages can be transformed into M1 macrophages, and can promote the proliferation, migration and ring-forming ability of esophageal cancer-associated LEC.

Association between spectral computed tomography images and clinicopathological features in advanced gastric adenocarcinoma

To investigate the role of spectral computed tomography (CT)-generated iodine concentration (IC) in the evaluation of clinicopathological features of advanced gastric adenocarcinoma (AGC), 42 patients who underwent abdominal enhanced CT with spectral imaging mode were selected for the present study. The IC of the primary lesion in the arterial phase (IC_AP) and portal venous phase (IC_VP) was measured and the IC of the aorta was used for a normalized iodine concentration (nIC). Micro-vessel density (MVD) and lymphatic vessel density (LVD) were detected using immunohistochemical assays against cluster of differentiation 34 and D2-40, respectively. Other clinicopathological characteristics were also documented. The IC parameters were revealed to be significantly increased in the high-MVD group, particularly for the nIC_VP (P=0.002). Additionally, the nIC_AP revealed a significant difference (P=0.041) between the high- and low-LVD group. The nIC_AP and nIC_VP were increased in the poorly differentiated group compared with the moderately differentiated group (P=0.040 and P=0.011, respectively). The ICs and MVD demonstrated a statistically significant positive linear correlation. nIC_VP was able to be used to discriminate between the moderately and poorly differentiated carcinomas, with an area under the receiver operating characteristic curve of 0.759. However, IC demonstrated no correlation with serosal involvement, lymph node metastasis, LVD, and nodular or metastatic tumors. The results of the present study suggest that the nIC_VP value may serve as a non-invasive marker for the angiogenesis of, and the differentiations between, patients with AGC.

MiR-34a Promotes Apoptosis and Inhibits Autophagy by Targeting HMGB1 in Acute Myeloid Leukemia Cells

BACKGROUND

MiR-34a is identified as a tumor suppressor gene and involved in acute myeloid leukemia (AML) development. However, the regulatory mechanism of miR-34a in AML is unclear.

METHODS

The expression of miR-34a and HMGB1 in HL-60, THP-1 and HS-5 cells were detected by qRT-PCR and western blot. Lipofectamine 2000 was used to transfect with miR-34a mimics, miR-34a inhibitor, si-HMGB1, pcDNA 3.1-HMGB1, and corresponding controls. The apoptosis and autophagy of transfected AML cells were assessed by flow cytometry and western blot, respectively. Bioinformatics software and dual luciferase reporter assay were applied to predict and verify the target of miR-34a. The effects of miR-34a mimics or si-HMGB1 on chemotherapy-induced autophagy were further explored in HL-60 cells treated with all-trans retinoic acid (ATRA) along with lysosomal protease inhibitors E64d and pepstatin A.

RESULTS

MiR-34a was lower expressed and HMGB1 mRNA and proteins were both higher expressed in HL-60 and THP-1 cells compared with that in HS-5 cells. Higher expression levels of MiR-34 and lower expression levels of HMGB1 both significantly promoted apoptosis and inhibited autophagy in HL-60 and THP-1 cells. Dual luciferase reporter system confirmed that HMGB1 was a potential target of miR-34a. Moreover, overexpression of HMGB1 dramatically reversed the promotion of apoptosis and inhibition of autophagy mediated by higher expression level of miR-34a. Higher expression level of miR-34a and lower expression level of HMGB1 both inhibited chemotherapy-induced autophagy by stimulating the LC3 conversion.

CONCLUSION

MiR-34a promoted cell apoptosis and inhibited autophagy by targeting HMGB1. Therefore, miR-34a may be a potential promising molecular target for AML therapy.

Effect of VEGF-C siRNA and endostatin on ring formation and proliferation of esophageal squamous cell carcinoma lymphatic endothelial cells

Objective

To study the effects of vascular endothelial growth factor C small interfering RNA and endostatin on esophageal squamous cell carcinoma-related ring formation in vitro and proliferation of lymphatic endothelial cells.

Materials and methods

KYSE150 cells were subjected to analysis of cell transfection and endostatin operation. The groups were as follows: negative group, blank group, negative plus endostatin group, endostatin group, SG1 group, SG2 group, SG1 plus endostatin group, and SG2 plus endostatin group. The esophageal cancer-related microlymphatic endothelial cells were three-dimensionally cultured. Cell Counting Kit-8 (CCK-8) assay was employed to detect cell proliferation.

Results

The negative group’s three-dimensional culture result was the highest, followed by the blank group, negative plus endostatin group, endostatin group, SG2 group, SG1 group, SG1 plus endostatin group, and SG2 plus endostatin group. The quantity of living cells in the blank group was the highest, followed by the negative control, endostatin, SG2, SG1, negative plus endostatin, SG1 plus endostatin, and SG2 plus endostatin groups.

Conclusion

Both vascular endothelial growth factor C small interfering RNA and endostatin could inhibit ring formation in esophageal squamous cell carcinoma and proliferation of lymphatic endothelial cells.

BLCA-4 and UBC combined detection for early diagnosis of bladder cancer

The objective of the present study was to report the clinical significance of bladder cancer specific nuclear matrix protein 4 (BLCA-4) and urinary bladder cancer (UBC) on early diagnosis of bladder cancers. Enzyme-linked immunosorbent assay (ELISA) was used to detect BLCA-4 and UBC of 56 bladder cancer patients and 26 patients with urinary tract benign diseases, serving as controls. Urine exfoliated cell test was performed, and then the significance of BLCA-4 and UBC on the diagnosis of bladder cancers was analyzed. The sensitivity of BLCA-4 and UBC of the bladder cancer patients was significantly higher than that of the urine exfoliated cell test (P less than 0.05). The difference of BLCA-4 and UBC was not significant (P >0.05). The difference of BLCA-4 and UBC in the tumors with different gradings and stagings was not significant (P >0.05). Combined detection of BLCA-4 and UBC could improve the diagnosis sensitivity and specificity of bladder cancers with the advantages of high maneuverability, repeatability and objective results.

The Sensitive Detection of Telomerase Reverse Transcriptase Promoter Mutation by Amplification Refractory Mutation System-PCR

AIM

In gliomas, mutations in the core promoter region of the telomerase reverse transcriptase (TERT) gene have been associated with specific subtypes and are inversely correlated with IDH1 mutation status, predicting poor prognosis. Thus, TERT promoter mutation status might be a candidate for development as a prognostic biomarker. However, current IDH1 mutation detection methods using conventional polymerase chain reaction (PCR), followed by Sanger sequencing, have low sensitivity and are time-consuming. To improve test efficacy, we developed a more efficient detection protocol based on an amplification refractory mutation system-PCR (ARMS-PCR), which is based on the principle that DNA extension only happens when the 3'-terminal nucleotide of a primer matches its target sequence.

MATERIALS AND METHODS

We generated plasmids containing TERT promoter sequences and optimized this new protocol for the identification of the two most common TERT promoter mutations, C250T and C228T.

RESULTS

The enhanced sensitivity and efficiency of this protocol were validated using 124 human glioma samples.

CONCLUSION

We have described an ARMS-PCR methodology with improved sensitivities that could replace current commonly used methods for the detection of TERT promoter mutations in gliomas.

ZEB1 promotes the progression and metastasis of cervical squamous cell carcinoma via the promotion of epithelial-mesenchymal transition

OBJECTIVE

The process of epithelial-mesenchymal transition (EMT) clearly contributes to cancer metastasis. The aim of this study was to investigate the expression of the EMT-related transcription repressor ZEB1 and the expression of EMT-associated markers (E-cadherin, β-catenin and N-cadherin) in cervical squamous cell carcinoma. In addition, the role of ZEB1 and these EMT-associated markers in the progression and metastasis of cervical squamous cell carcinoma was explored.

METHODS

The expression of ZEB1, E-cadherin, β-catenin and N-cadherin was evaluated in 81 specimens of cervical squamous cell carcinoma by immunohistochemistry; the clinicopathological significance of these markers was then analyzed.

RESULTS

1) Of the 81 samples, 37 cases (45.7%) were positive for ZEB1, and nuclear expression of ZEB1 in tumor cells was positively associated with the differentiation status of the tumor tissue (P < 0.05), vascular invasion (P < 0.05) and lymph node metastasis (P < 0.05). 2) The loss of E-cadherin and β-catenin expression in tumor cells and the acquisition of N-cadherin expression were positively associated with the differentiation status of the tumor tissue (P < 0.05) and with the occurrence of vascular invasion (P < 0.05). 3) A significant negative correlation was observed between ZEB1 and E-cadherin expression (Spearman = -0.636, P < 0.05) and between ZEB1 and β-catenin expression (Spearman = -0.417, P < 0.05). Moreover, a significant positive correlation was observed between ZEB1 and N-cadherin expression (Spearman = 0.557, P < 0.05).

CONCLUSIONS

These results emphasize the role of EMT in cervical squamous cell carcinoma. The upregulation of ZEB1 is associated with the abnormal expression of E-cadherin, β-catenin and N-cadherin, which might promote the progression and metastasis of cervical squamous cell carcinoma.

Influence of lymphatic endothelial cells on proliferation and invasiveness of esophageal carcinoma cells in vitro and lymphangiogenesis in vivo

The aim of the study was to investigate the interaction between esophageal carcinoma cells with different differentiation degree and esophageal carcinoma-related lymphatic endothelial cells. Different lymphatic endothelial cell conditioned mediums were used to cultivate well-differentiated esophageal carcinoma EC9706 cells and poorly differentiated esophageal carcinoma KYSE150 cells, and immunocytochemistry and Western blot analyses were applied to detect the expression of MMP-9 protein and TIMP-2 protein in each group; in situ hybridization and RT-PCR methods were used to detect the expression of MMP-9 and TIMP-2 mRNA in each group; CCK-8 method was used to detect cell proliferation in each group; and transwell method was utilized to detect cell invasiveness in each group. Through constructing the transplanted tumor model of esophageal carcinoma of nude mice, the D2-40 and LYVE-1 immunohistochemical staining was performed on transplanted tumors and surrounding tissues, lymphatic microvessels were marked, and lymphatic microvessel density (LMVD) was measured. The expression of MMP-9 protein and mRNA in experimental group was significantly higher than that in control groups (P < 0.05); TIMP-2 protein and mRNA expression in experimental group was significantly lower than that in control groups (P < 0.05); cell proliferation ability and invasiveness ability in experimental group were significantly higher than those in control groups (P < 0.05); LMVD-marked D2-40 and LMVD-marked LYVE-1 of transplanted tumor tissue in the experimental group were significantly higher than those in control groups (P < 0.05). The esophageal squamous carcinoma-related lymphatic microvessel could promote the proliferation and invasive ability of esophageal squamous carcinoma cells in vitro. It had different effects on esophageal carcinoma cells with different differentiation degree and had more obvious influence on poorly differentiated esophageal carcinoma cells, which may be related to the up-regulated MMP-2 expression and down-regulated TIMP-2 expression of esophageal carcinoma cells. The esophageal squamous carcinoma-related lymphatic microvessel endothelial cells could promote the growth of esophageal carcinoma-transplanted tumor of nude mice and lymphangiogenesis.

Genetic variability of DNA repair mechanisms influences treatment outcome of gastric cancer

The aim of the current study was to investigate the role of polymorphisms in DNA repair pathways on the clinical outcome of gastric cancer patients treated with platinum-based chemotherapy. A total of 380 gastric cancer patients treated with platinum-based chemotherapy were included in the present study. The genotypes of ERCC1 rs11615 (Asn118Asn) and rs3212986 (*197G>T), ERCC2 rs1799793 (Asn312Asp) and rs13181 (Lys751Gln), NBN rs1805794 (Gln185Gln) and rs1063054 (*1209A>C), RAD51 rs1801321 (-61G>T) and rs12593359 (*502T>G), and XRCC3 rs861539 (Thr241Met) were determined by polymerase chain reaction-restriction fragment length polymorphism, according to the manufacturer's instructions. The TC+CC genotypes of ERCC1 rs11615 and GA+AA genotypes of ERCC2 rs1799793 were found to be associated with improved response to chemotherapy, with an adjusted odds ratio of 1.66 (95% CI, 1.07-2.56) and 1.61 (95% CI, 1.05-2.49), respectively. Based on the results of Cox analysis, patients with TC+CC genotypes of ERCC1 rs11615 and GA+AA genotypes of ERCC2 rs1799793 exhibited a significantly decreased risk of mortality, with hazard ratios of 1.71 (95% CI, 1.06-2.72) and 1.97 (95% CI, 1.28-3.03), respectively. In conclusion, these results suggest that ERCC1 rs11615 and ERCC2 rs1799793 in the DNA repair pathways may be used as predictive factors of the clinical outcome in gastric cancer patients.

Polymorphisms in different EST-SSR types derived from the Chinese bayberry Myrica rubra, Myricaceae) transcriptome

Most plant expressed sequence tag-simple sequence repeats (EST-SSRs) are not polymorphic, and it is important to learn the characteristics of highly polymorphic EST-SSRs. In this study, 357 compound and 5557 non-compound EST-SSRs, identified from the transcriptome of the Chinese bayberry (Myrica rubra 'Biqi'), were divided into 11 types based on their characteristics. Polymorphisms in all 11 EST-SSR types were investigated in 10 cultivars. The percentages of polymorphic loci ranged from 12.9 to 87.5%, with 2-ntL having the highest, followed by 3-ntL, Compound B, and Compound A. The number of alleles and the polymorphic information content of 2-ntL and Compound B were the highest, followed by 2-ntM and Compound A. Therefore, we recommend that 2-ntL, Compound B, and Compound A EST-SSRs should be preferentially selected for the screening of polymorphic EST-SSRs in the Chinese bayberry. Our results should facilitate genetic and breeding studies of this species, and provide a reference for similar study in other plant species.

MiR-498 regulated FOXO3 expression and inhibited the proliferation of human ovarian cancer cells

Ovarian cancer is one of the most common human malignancies and the fifth leading cause of cancer deaths in women. Thus, improved approaches for detection of ovarian cancer are urgently needed. Recently, microRNAs (miRNAs) have been suggested to be closely associated with ovarian cancer tumorigenesis. In the current study, our study showed that expression of miR-498 was markedly downregulated in ovarian cancer cells and ovarian cancer tissues compared with human ovary surface epithelial cells (HOSE) and the matched tumor adjacent normal tissues (ANT). Ectopic expression of miR-498 suppressed cell proliferation of ovarian cancer cells, while i miR-498-in showed the opposite effect. Furthermore, upregulation of miR-498 in ovarian cancer cells resulted in blocking of their entry into the S transitional phase, which was caused by downregulation of the CDK regulator cyclin D1 and upregulation of cyclin-dependent kinase inhibitor p27. Additionally, we identified FOXO3 as a direct target of miR-498. Moreover, we demonstrated that miR-498 upregulated FOXO3 expression by directly targeting the FOXO3 3'-untranslated region. Thus, our findings suggested that miR-498 acted as a new tumor suppressor by targeting the FOXO3 gene and inhibiting cell proliferation of ovarian cancer.

Impact on growth and invasion of gastric cancer cell lines by silencing NEDD9

Background

Gastric adenocarcinoma is a predominant disease with latent attribute, high malignancy, and poor prognosis in People’s Republic of China. Gastric cancer is the most common malignant tumor of the digestive tract. It has been suggested that abnormal expression of NEDD9 was associated with stage progression and metabolism of carcinomas. Some authors demonstrated that both messenger RNA (mRNA) and protein of NEDD9 were highly expressed in gastric cancer, and paired paracancerous atypical hyperplasia tissues were correlated with lymph node metastasis, tumor depth, and tumor-lymph node-metastasis (TNM) staging. In this study, we found that NEDD9 small interfering RNA (siRNA) can induce apoptosis and suppress proliferation, migration, and invasion of BGC823 cell lines. These findings suggested that NEDD9 siRNA might serve as a tumor suppressor by targeting NEDD9 in gastric cancer cell. It has been suggested that abnormal expression of NEDD9 was associated with carcinogenesis, and in the first part of the study, we found that NEDD9 was highly expressed in gastric cancer tissues; and it too was correlated with lymph node metastasis, tumor depth, and TNM staging. In this project, experiments were carried out to silence NEDD9 in BGC823 cell lines using NEDD9 siRNA, and the biological activity of BGC823 cells was observed after RNA interference.

Methods

The target analysis of NEDD9 siRNA was forecast using online tools. In order to determine a more efficient NEDD9 siRNA, three pairs of NEDD9 siRNA primer were designed, synthesized, and then transfected into BGC823 cells. NEDD9-2 siRNA was finally adopted by detecting the quantitative real-time polymerase chain reaction (qRT-PCR). Cells were collected for detecting mRNA by qRT-PCR or protein by western blot analysis. Cell apoptosis was detected using flow cytometry, and the transwell invasion system was used for cell migration and invasion assays. The effect of NEDD9 siRNA in silencing the target gene in BGC823 cells was then assessed. Also, the impact of NEDD9-2 siRNA on cell proliferation, apoptosis, migration, and invasion were detected in BGC823 cell lines.

Results

The relative quantity of expression of mRNA and protein showed a decrease in all cells transfected with siNEDD9-2 at different concentrations. The cell proliferation inhibition assay showed that the inhibition rate was significantly increased in all transfected cells compared with control groups. Cell apoptosis assay showed that the number of living cells were significantly reduced compared with control groups, and cell migration and invasion assay showed that siNEDD9 could inhibit BGC823 cell migration and invasion in vitro.

Conclusion

NEDD9 siRNA could inhibit expression of NEDD9 and induce apoptosis, suppress proliferation, migration, and invasion of BGC823 cells, acting as a tumor suppressor in carcinogenesis of gastric cancer. These findings suggested that NEDD9 siRNA plays an important role in the proliferation, apoptosis, and invasion of BGC823 cells.

Clinical significance of mTOR and eIF4E expression in invasive ductal carcinoma

AIMS AND BACKGROUND

Mammalian target of rapamycin (mTOR) is one of the serine-threonine protein kinases and plays an important regulatory role in cell growth. Eukaryotic translation initiation factor 4E (eIF4E) and 4E binding protein (4EBP) are the downstream proteins of mTOR signaling pathway and are the most efficient speed regulator of eukaryotic mRNA translation. The aim of the study was to investigate the clinical significance of mTOR, eIF4E and 4EBPs expression in invasive ductal carcinoma.

METHODS

Fresh biopsy specimens of invasive ductal carcinoma tissues and normal breast tissues were collected from 45 patients with breast cancer. The expressions of mTOR, eIF4E and 4EBPs in specimens were detected by an immunohistochemical SP method, and the relationship of mTOR, eIF4E and 4EBPS expressions and of their expressions with tumor metastasis were analyzed.

RESULTS

Expressions of mTOR, eIF4E and 4EBPs in invasive ductal carcinoma were significantly higher than in normal breast tissue (P <0.05). mTOR expression was positively correlated with eIF4E and 4EBP expression in invasive ductal carcinoma (P <0.05). The positive rates of mTOR, eIF4E and 4EBPs in patients with lymph node metastasis were significantly higher than in patients without lymph node metastasis (P <0.05).

CONCLUSIONS

Increased expressions of mTOR and eIF4E in invasive ductal carcinoma may be correlated with the occurrence and metastasis of breast cancer.

Study on effect of the expression of siRNA in gastric cancer bearing nude mice transplanted tumor NEDD9 gene

The clinical study found that NEDD9 showed high expression on the invasion in gastric cancer tissues and metastasis of the tumor. Based on promoting the fundamental role (Sisen et al., 2013) to the expression level, the author further study NEDD9 siRNA, which could significantly reduce NEDD9 protein and mRNA in gastric cancer BGC823 cells, inhibition of cell proliferation, induce cell apoptosis, and decrease the invasiveness of gastric cancer cells, suggesting that NEDD9 plays an important role in the gastric cancer cell proliferation, apoptosis and invasion force. Through constructing a model transplanted gastric cancer in nude mice, the author observes the effect of NEDD9 siRNA on the growth of gastric cancer x-engrafts, and application of NEDD9 immunohistochemical SP method. The author also uses Western blot method to detect the gastric carcinoma in nude mice transplanted tumor tissues expression; applies situ hybridization, RT-PCR technology to detect the gastric cancer engraft tissues in NEDD9 mRNA. In order to further explore the relationship between NEDD9 and the development of gastric cancer, he provides a theoretical basis for the NEDD9 targeted therapy.