Potential Target For Gene Therapy Research Articles

LncRNA in the liver: Prospects for fundamental research and therapy by RNA interference.

Long non-coding RNAs constitute the most abundant part of the transcribed mammalian genome. lncRNAs affect all essential processes in the living cell including transcription, splicing, translation, replication, shaping of chromatin and post translational modification of proteins. Alterations in lncRNA expression have been linked to a number of diseases; thus, modulation of lncRNA expression holds a huge potential for gene-based therapy. In this review we summarize published data about lncRNAs in the context of hepatic carcinogenesis and liver fibrosis, and the corresponding potential targets for gene therapy. Recent advancements in targeted delivery to the liver made RNA interference an invaluable tool to decipher hepatic lncRNA function and to develop lncRNA-oriented therapies for liver-involved diseases in the future. Different approaches for RNA delivery that can be used for functional studies in the lab and for clinical lncRNA based applications are critically discussed in this review.

Adeno-associated viral vector-mediated anti-inflammasome gene transfer alleviates asthmatic airway inflammation in OVA-sensitized mice model

Abstract Bronchial asthma is a chronic inflammatory disorder of the airway characterized by airway hyperresponsiveness (AHR), pulmonary eosinophilia, elevated serum IgE, and dysregulated T helper (Th) 2 cytokines. It is becoming urgent to identify target molecules for the preventive and therapeutic purpose. ATP accumulation in bronchoalveolar lavage fluid (BALF) of asthmatic subjects indicates that extracellular ATP and the downstream responses are involved. ATP is an activator of NLRP3 inflammasomes and tightly regulated by CD39, a nucleoside triphosphate diphosphohydrolase encoded by entpd1. Upregulated BALF ATP levels and decreased CD39 RNA were accompanied with asthmatic cardinal features in ovalbumin (OVA)-sensitized mice. Recombinant adeno-associated virus (rAAV) has been developed to carry exogenous genes with safe and low toxic therapeutic potential. The different serotypes and tropisms of AAVs benefit tissue specific gene targeting. This study aims for determining whether lung-targeting rAAV carrying CD39 (AAV/CD39) is able to reduce extracellular ATP in BALF and inhibit the OVA-induced allergic inflammation in an asthmatic murine model. The mice were sensitized and challenged with OVA. rAAV vectors were administrated into the lungs of mice 3 days before the first OVA exposure. The data indicated that ATP levels in BALF were downregulated accompanied with rescued CD39 expression. The administration of AAV/CD39 was able to suppress AHR, pulmonary eosinophilia, and the production of IL-5 from OVA-activated mediastinal lymph nodes (MLNs) cells. The treatment of AAV/CD39 attenuated the asthmatic airway inflammation and AHR. Collectively, ATP could be a potential target for gene therapy on asthma.

Elevated RNA expression of long non‑coding HOTAIR promotes cell proliferation and predicts a poor prognosis in patients with diffuse large B cell lymphoma.

Diffuse large B cell lymphoma (DLBCL) is one of the most common types of malignancy worldwide. The lack of clear symptoms and early detection make it difficult to diagnose at an early stage, leading to poor prognosis of the patients. Long non-coding RNAs (lncRNAs) have come into focus for their important regulatory roles in fundamental biological processes, particularly in cancer initiation, development and progression. The aim of the present study was to investigate the expression of lncRNA Hox transcript antisense intergenic RNA (HOTAIR) in a cohort of patients with DLBCL to assess its clinical value and biological function in DLBCL. The reverse transcription-polymerase chain reaction was used to detect HOTAIR expression levels and cells were transfected with small interfering RNA to compare cell proliferation, cell cycle progression and apoptosis. Western blotting was also conducted to detect possible signaling pathways. It was first found that the expression levels of HOTAIR were upregulated in DLBCL tumor tissues and cell lines, compared with normal tissues and cells. In addition, HOTAIR was significantly correlated with tumor size, clinical stage, B symptoms and International Prognostic Index scores; and higher expression levels of HOTAIR were correlated with improved prognosis. Univariate and multivariate analyses verified that HOTAIR was a key independent predictive factor for DLBCL prognosis. Furthermore, it was revealed that the knockdown of the expression of HOTAIR led to growth inhibition, cell cycle arrest and apoptosis in vitro, possibly through the phosphoinositide 3-kinase/AKT/nuclear factor-κB pathway. These results suggested that HOTAIR may be regarded as a novel indicator of poor prognosis, and may serve as a potential target for gene therapy in the treatment of DLBCL.

LOC100287225, novel long intergenic non-coding RNA, misregulates in colorectal cancer.

Colorectal cancer (CRC) is one of the most common cancers in the world; therefore, extensive research is needed to find new molecular therapeutic targets and biomarkers. LncRNA (long non-coding RNA), a new class of non-coding RNAs, has a crucial role in the onset and progression of various cancers including colorectal cancer. Research on lncRNA is still at initial stages and underlying molecular mechanisms of the vast majority of lncRNA have remained unclear. LOC100287225 is one of these novel lncRNAs (long intergenic non-coding RNA) located in the long arm of the chromosome 18. The purpose of this study was to determine the expression of LOC100287225 in colorectal tissue, and its misregulation in CRC patients. Quantitative real-time-PCR (qRT-PCR) was used to investigate the LOC100287225 expression in pairs of tumorous and adjacent tumor-free tissues of 39 colorectal cancer patients. Also, the relationship between the clinicopathology and expression of LOC100287225 was determined. QRT-PCR results revealed that not only is LOC100287225 expressed in the intestinal tissue, but has also been misregulated during tumorigenesis. Moreover, LOC100287225 RNA relative expression levels were significantly lower in tumor tissues compared with adjacent tumor-free tissues (P< 0.001). RNA expression level of LOC100287225 did not show significant correlation with clinical characteristics. In conclusion, our study demonstrated that LOC100287225 misregulation could be a potential target for gene therapy in colorectal cancer.

Down-regulation of S100A9 inhibits osteosarcoma cell growth through inactivating MAPK and NF-κB signaling pathways.

BackgroundOsteosarcoma (OS) is well-known for poor prognosis due to its high incidence of proliferation and metastasis. Researches have provided valuable insights into the tumorigenesis of S100A9 in some cancers. We aimed to understand the expression level, functions and mechanisms of S100A9 in human osteosarcoma for the first time.MethodsThe expression of S100A9 protein was detected in 120 human osteosarcoma tissues and 40 normal human bone tissues using tissue microarrays analysis. The knockdown of S100A9 induced by RNA interference (RNAi) method in three osteosarcoma cell lines (U2OS, 143B, MG63) was applied to analyze the effects of S100A9 on cell proliferation, cell cycle distribution, migration, invasion and xenotransplanted tumors. Moreover, MAPK-ERK1/2, MAPK-p38, NF-κB-p65, NF-κB-p50, p21, p27, CDK2 and CDK4 were tested.ResultsThe expression of S100A9 was increased in human osteosarcoma issues and was positively correlated with clinical classification and survival rate. Down-regulation of S100A9 inhibited OS cellular proliferation, migration, invasion and cell cycle S phase in vitro and suppressed tumor formation in vivo with the reduction on PCNA and Ki67 proliferation index. Our data also demonstrated that knockdown of S100A9 repressed the protein levels of phospho-ERK1/2, phospho-p50, phospho-p65 except phospho-p38, and prompted up-regulation of p21 and p27 leading to inactivation of cyclin dependent kinase 2(CDK2) and cyclin dependent kinase 4(CDK4).ConclusionsS100A9 might be a significant role for predicting osteosarcoma prognosis and down-regulation of S100A9 could be used as a potential target for gene therapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2294-1) contains supplementary material, which is available to authorized users.

Relevance of miR-21 in regulation of tumor suppressor gene PTEN in human cervical cancer cells.

BackgroundExpression of the microRNA miR-21 has been found to be altered in almost all types of cancers and it has been classified as an oncogenic microRNA or oncomir. Due to the critical functions of its target proteins in various signaling pathways, miR-21 is an attractive target for genetic and pharmacological modulation in various cancers. Cervical cancer is the second most common cause of death from cancer in women worldwide and persistent HPV infection is the main etiologic agent. This malignancy merits special attention for the development of new treatment strategies. In the present study we analyze the role of miR-21 in cervical cancer cells.MethodsTo identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression in a cervical intraepithelial neoplasia-derived cell lines using siRNAs. The effect of miR-21 on gene expression was assessed in cervical cancer cells transfected with the siRNA expression plasmid pSIMIR21. We identified the tumor suppressor gene PTEN as a target of miR-21 and determined the mechanism of its regulation throughout reporter construct plasmids. Using this model, we analyzed the expression of miR-21 and PTEN as well as functional effects such as autophagy and apoptosis induction.ResultsIn SiHa cells, there was an inverse correlation between miR-21 expression and PTEN mRNA level as well as PTEN protein expression in cervical cancer cells. Transfection with the pSIMIR21 plasmid increased luciferase reporter activity in construct plasmids containing the PTEN-3′-UTR microRNA response elements MRE21-1 and MRE21-2. The role of miR-21 in cell proliferation was also analyzed in SiHa and HeLa cells transfected with the pSIMIR21 plasmid, and tumor cells exhibited markedly reduced cell proliferation along with autophagy and apoptosis induction.ConclusionsWe conclude that miR-21 post-transcriptionally down-regulates the expression of PTEN to promote cell proliferation and cervical cancer cell survival. Therefore, it may be a potential therapeutic target in gene therapy for cervical cancer.

Upregulation of metastasis-associated gene 2 promotes cell proliferation and invasion in nasopharyngeal carcinoma.

AimsMetastasis-associated gene 2 (MTA2) is reported to play an important role in tumor progression, but little is known about the role of MTA2 in nasopharyngeal carcinoma (NPC). The aim of the study was to explore the expression and function of MTA2 in NPC.MethodsExpression of MTA2 in NPC tissues and cell lines was detected by immunohistochemistry and Western blotting. Relationship between MTA2 expression and clinicopathological features was analyzed. Stable MTA2-overexpressing and MTA2-siliencing NPC cells were established by transfection with plasmids encoding MTA2 cDNA and lentivirus-mediated short hairpin RNA, respectively. Cell viability was determined by Cell Counting Kit-8 and colony formation assay. Cell migration ability was evaluated by wound healing and transwell invasion assay. The impact of MTA2 knockdown on growth and metastasis of CNE2 cells in vivo was determined by nude mouse xenograft models. Expression of several Akt pathway proteins was detected by Western blotting.ResultsMTA2 was upregulated in NPC tissues and three NPC cell lines detected (CNE1, CNE2, and HNE1). MTA2 expression was related to clinical stage and lymph node metastasis of patients with NPC. MTA2 upregulation promoted proliferation and invasion of CNE1 cells, while MTA2 depletion had opposite effects on CNE2 cells. Moreover, MTA2 depletion suppressed growth and metastasis of CNE2 cells in vivo. MTA2 overexpression activated Akt and upregulated the expression of matrix metalloproteinase 7 and cyclin D1.ConclusionWe conclude that MTA2 acts as an oncogene in tumorigenesis of NPC. MTA2 may be a potential target for gene therapy in NPC.

Overexpression of SDF-1 activates the NF-κB pathway to induce epithelial to mesenchymal transition and cancer stem cell-like phenotypes of breast cancer cells

The formation of EMT and EMT-induced CSC-like phenotype is crucial for the metastasis of tumor cells. The stromal cell-derived factor-1 (SDF-1) is upregulated in various human carcinomas, which is closely associated with proliferation, migration, invasion and prognosis of malignancies. However, limited attention has been directed towards the effect of SDF-1 on epithelial to mesenchymal transition (EMT) or cancer stem cell (CSC)-like phenotype formation in breast cancer cells and the related mechanism. In the present study, we screened MCF-7 cells with low SDF-1 expression level for the purpose of evaluating whether SDF-1 is involved in EMT and CSC-like phenotype formation in MCF-7 cells. The pEGFP-N1-SDF-1 plasmid was transfected into MCF-7 cells, and the stably overexpressed SDF-1 in MCF-7 cells was confirmed by real-time PCR and western blot analysis. Colony formation assay, MTT, wound healing assay and Transwell invasion assay demonstrated that overexpression of SDF-1 significantly boosted the proliferation, migration and invasion of MCF-7 cells compared with parental (P<0.05). Flow cytometry analysis revealed a notable increase of CD44+/CD24- subpopulation in SDF-1 overexpressing MCF-7 cells (P<0.001), accompanied by the apparently elevated ALDH activity and the upregulation of the stem cell markers OCT-4, Nanog, and SOX2 compared with parental (P<0.01). Besides, western blot analysis and immunofluorescence assay observed the significant decreased expression of E-cadherin and enhanced expression of slug, fibronectin and vimentin in SDF-1 overexpressed MCF-7 cells in comparison with parental (P<0.01). Further study found that overexpression of SDF-1 induced the activation of NF-κB pathway in MCF-7 cells. Conversely, suppressing or silencing p65 expression by antagonist or RNA interference could remarkably increase the expression of E-cadherin in SDF-1 overexpressed MCF-7 cells (P<0.001). Overall, the above results indicated that overexpression of SDF-1 enhanced EMT by activating the NF-κB pathway of MCF-7 cells and further induced the formation of CSC-like phenotypes, ultimately promoting the proliferation and metastasis of MCF-7 cells. Therefore, SDF-1 may further be assessed as a potential target for gene therapy of breast cancer.

Gene Network for Identifying the Entropy Changes of Different Modules in Pediatric Sepsis

Background/Aims: Pediatric sepsis is a disease that threatens life of children. The incidence of pediatric sepsis is higher in developing countries due to various reasons, such as insufficient immunization and nutrition, water and air pollution, etc. Exploring the potential genes via different methods is of significance for the prevention and treatment of pediatric sepsis. This study aimed to identify potential genes associated with pediatric sepsis utilizing analysis of gene network and entropy. Methods: The mRNA expression in the blood samples collected from 20 septic children and 30 healthy controls was quantified by using Affymetrix HG-U133A microarray. Two condition-specific protein-protein interaction networks (PINs), one for the healthy control and the other one for the children with sepsis, were deduced by combining the fundamental human PINs with gene expression profiles in the two phenotypes. Subsequently, distinct modules from the two conditional networks were extracted by adopting a maximal clique-merging approach. Delta entropy (ΔS) was calculated between sepsis and control modules. Results: Then, key genes displaying changes in gene composition were identified by matching the control and sepsis modules. Two objective modules were obtained, in which ribosomal protein RPL4 and RPL9 as well as TOP2A were probably considered as the key genes differentiating sepsis from healthy controls. Conclusion: According to previous reports and this work, TOP2A is the potential gene therapy target for pediatric sepsis. The relationship between pediatric sepsis and RPL4 and RPL9 needs further investigation.

MiR-490-5p suppresses tumour growth in renal cell carcinoma through targeting PIK3CA.

Background InformationDysregulated micro‐RNAs have been reported in many human cancers, including renal cell carcinoma. Recent studies indicated that miR‐490 is involved in tumour development and progression. However, the expression profile and function in renal cell carcinoma remains unknown.ResultsHerein, we showed that miR‐490‐5p was down‐regulated in renal cell carcinoma tissues and cells compared with the adjacent normal tissues and normal cells. We also provided evidence that miR‐490‐5p acts as a tumour suppressor in renal carcinoma in a variety of in vitro and in vivo assays. Mechanistically, miR‐490‐5p was verified to directly bind to 3′ UTR of the PIK3CA mRNA and reduce the expression of PIK3CA at both mRNA and protein levels, which further inhibits phosphatidylinositol 3‐kinase/Akt signalling pathway. We further showed that knockdown of PIK3CA can block the growth inhibitory effect of miR‐490‐5p, and over‐expression of PIK3CA can reverse the inhibitory effect of miR‐490‐5p on renal cancer cell tumourigenicity.ConclusionsTaken together, our results indicated for the first time that miR‐490‐5p functions as a tumour suppressor in renal carcinoma by targeting PIK3CA.SignificanceOur findings suggest that miR‐490‐5p may be a potential gene therapy target for the treatment of renal cell carcinoma.

Lentivirus‑mediated knockdown of MeCP2 inhibits the growth of colorectal cancer cells in vitro.

Methyl‑CpG‑binding protein 2 (MeCP2) is a transcriptional repressor that has been implicated in tumor onset and progression. Compared with normal and other tumorous tissue, MeCP2 is highly expressed in well‑differentiated adenocarcinoma and mucinous adenocarcinoma tissues, particularly at the invasion site of colorectal cancer tissues. The aim of the present study was to evaluate the potential of MeCP2 for use as a therapeutic target for human colorectal cancer. The DLD‑1 colorectal cancer cell line was subjected to lentivirus‑mediated short hairpin RNA‑induced knockdown of MeCP2 and the effects on cell growth, cell cycle progression and cell migration were assessed. It was confirmed that lentivirus‑mediated RNA interference successfully suppressed MeCP2 expression in vitro, which was demonstrated to result in reduced cell viability, cell cycle arrest in G0/G1 phase and inhibition of cell migration. These results indicated that MeCP2 may serve as a potential target for gene therapy of colorectal cancer.

MiR-296-5p suppresses cell viability by directly targeting PLK1 in non-small cell lung cancer.

Polo-like kinase 1 (PLK1), a critical kinase for mitotic progression, is overexpressed in a wide range of cancers. MicroRNAs (miRNAs) are a class of small non-coding RNA molecules and proposed to play important roles in the regulation of tumor progression and invasion. However, the relationship between PLK1 and miRNAs have remained unclear. In the present study, the association between PLK1 and miR-296-5p was investigated. The upregulation of PLK1 mRNA expression levels combined with the downregulation of miR-296-5p levels were detected in both non-small cell lung cancer (NSCLC) tissues and cell lines. Functional studies showed that knockdown of PLK1 by siRNA inhibited NSCLC cells proliferation. Impressively, overexpression of miR-296-5p showed the same phenocopy as the effect of PLK1 knockdown in NSCLC cells, indicating that PLK1 was a major target of miR-296-5p. Furthermore, using western blot analysis and luciferase reporter assay, PLK1 protein expression was proved to be regulated by miR-296-5p through binding to the putative binding sites in its 3'-untranslated region (3'-UTR). Taken together, the present study indicated that miR-296-5p regulated PLK1 expression and could function as a tumor suppressor in NSCLC progression, which provides a potential target for gene therapy of NSCLC.

Clonagem molecular do oncogene EZH2 de leucemia mieloide crônica e perspectivas terapêuticas

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasia, caused in 95 % of the cases by a cytogenetic abnormality characterized by the reciprocal translocation between chromosomes 9 and 22 t(9; 22) (q34; q11), resulting in Philadelphia chromosome (Ph).Considering that CML cure is only possible with a successful bone marrow transplantation and that there are resistance cases to the tyrosine kinase inhibitor Imatinib Mesylate, prescribed in first line drug treatment; it is important to know in detail the genes and proteins that are possibly altered in CML, favoring effective therapeutic strategies, optimized diagnosis and minimal residual disease detection. Among the new therapeutic approaches to CML is gene therapy, which, depending on the target gene, can be efficient to other neoplasms treatment. In this context, the aims of this work were: to proceed the molecular cloning of a DNA fragment from EZH2 gene, potential target for gene therapy, that promotes epigenetic alteration in CML and in many neoplasms; as well as to contribute to studies related to interspecies gene transfer that have high contribution to health. For this reason, the EZH2 gene was isolated from peripheral blood genomic DNA from CML patients and cloned in prokaryotic systems. Therefore, in this study, we proceed, defined and proved the interspe-cies gene transfer procedures and discussed the future of biotechnology in researches and treatments, especially in CML.

A novel mutation in SIRT1-AS leading to a decreased risk of HCC.

Natural antisense transcripts (NATs) have recently been associated with the development of human cancers. However, the interrelationship between NATs and their sense transcripts in hepatocellular carcinoma (HCC) has not been well-characterized. The aim of the present study was to characterize the AS lncRNA SIRT1-AS, which suppressed the miRNA-induced translational repression of SIRT1 mRNA by masking the miR-29c binding site on the SIRT1 3'UTR. A 763-nucleotide (nt), single-exon NAT transcribed from the antisense strand of SIRT1 gene, designated as SIRT1-AS, was identified using strand-specific RT-PCR and northern blot analyses. SIRT1-AS overexpression promoted the prolife-ration of the human HCC cell lines by upregulating the SIRT1 protein level. The mechanism was that SIRT1-AS bound to SIRT1 mRNA at 3'UTR, masked the miR-29c binding site and stabilized SIRT1 mRNA. A single-nucleotide mutation (622U>C) in the SIRT1-AS sequence was found when we used gene sequencing as an assistant approach for HCC diagnosis. Bioinformatics and the RNase protection assay revealed that the mutation led to a marked alteration in the secondary structure of SIRT1-AS and caused its inability to bind with SIRT1 mRNA. Overexpression of this mutant did not have a promoting effect on HCC cell proliferation. Moreover, the mean level of SIRT1-AS was much higher in the HCC patients compared to non-hepatopathy volunteers (P<0.01), whereas the opposite effect was observed for the mutant ratio. The odds ratio (OR) analysis also suggested the 622C mutation reduced the risk of HCC. Taken together, we identified a novel mutation in SIRT1-AS leading to a decreased risk of HCC. The results of the present study suggest that the 622C mutant of SIRT1 antisense transcript suppresses HCC cell line proliferation, decreases the risk of HCC and is a potential target for gene therapy.

Effect of phosphorylation and methylation on the function of the p16INK4a protein in non-small cell lung cancer A549 cells.

The p16INK4a protein (p16) has been reported to be a tumor suppressor gene that suppresses the proliferation of cells through the direct inhibition of cell cycle progression. Accordingly, p16 is a potential target for cancer gene therapy. In the present study, the arginine 22, 131 and 138 residues of p16 were found to be methylation sites, as the mutation of these arginine residues to lysine resulted in the hypomethylation of p16. Furthermore, the protein arginine methyltransferases (PRMTs), such as PRMT1, PRMT4 and PRMT6, were determined to be involved in the methylation of the p16 arginine residues. PRMT6 effectively reduced the intensity of the association between p16 and CDK4, and also weakened the function of p16 in preventing cell proliferation. In addition, the p16 protein was found to be phosphorylated in various cell lines, and mutations in the serine residues weakened the cell cycle arrest and induction of apoptosis mediated by p16. Preliminarily, the crosstalk between the phosphorylation and arginine methylation modification of p16 was examined. These findings predict a role for serine phosphorylation against arginine methylation of p16.

Increased urothelial cancer associated 1 is associated with tumor proliferation and metastasis and predicts poor prognosis in colorectal cancer

Long non-coding RNA, urothelial cancer associated 1 (UCA1), is reported to play a critical role in progression of carcinogenesis. In the present study, we identified differential expression of UCA1 in colorectal cancer (CRC) and paired peritumoral tissues using gene expression microarray analyses. qPCR analysis confirmed that UCA1 was upregulated in CRC (p<0.001) and the expression of UCA1 was statistically correlated with lymph node metastasis (P=0.040), distant metastasis (P=0.043) and tumor stage (P=0.010). Kaplan-Meier analysis indicated that patients with high UCA1 expression had a poor prognosis. Moreover, multivariate analysis identified UCA1 overexpression as an independent predictor for CRC. We also found that knockdown of UCA1 significantly suppressed cell proliferation and metastasis in CRC cells. Flow cytometry assays showed UCA1 silencing induced G0/G1 growth arrest and apoptosis of CRC cells. To further investigate the regulatory mechanisms of UCA1, we identified that Ets-2 bound to the UCA1 core promoter using luciferase assays. Collectively, our findings suggested that UCA1 might be an important prognostic indicator in CRC and may be a potential target for diagnosis and gene therapy.

Design of Cationic Multiwalled Carbon Nanotubes as Efficient siRNA Vectors for Lung Cancer Xenograft Eradication.

Polo-Like Kinase (PLK1) has been identified as a potential target in cancer gene therapy via chemical or genetic inhibitory approaches. The biomedical applications of chemically functionalized carbon nanotubes (f-CNTs) in cancer therapy have been studied due to their ability to efficiently deliver siRNA intracellularly. In this study, we established the capacity of cationic MWNT-NH3(+) to deliver the apoptotic siRNA against PLK1 (siPLK1) in Calu6 tumor xenografts by direct intratumoral injections. A direct comparison with cationic liposomes was made. This study validates the PLK1 gene as a potential target in cancer gene therapy including lung cancer, as demonstrated by the therapeutic efficacy of siPLK1:MWNT-NH3(+) complexes and their ability to significantly improve animal survival. Biological analysis of the siPLK1:MWNT-NH3(+) treated tumors by qRT-PCR and Western blot, in addition to TUNEL staining confirmed the biological functionality of the siRNA intratumorally, suggesting that tumor eradication was due to PLK1 knockdown. Furthermore, by using a fluorescently labeled, noncoding siRNA sequence complexed with MWNT-NH3(+), we established for the first time that the improved therapeutic efficacy observed in f-CNT-based siRNA delivery is directly proportional to the enhanced siRNA retention in the solid tumor and subsequent uptake by tumor cells after local administration in vivo.

Analysis of UHRF1 expression in human ovarian cancer tissues and its regulation in cancer cell growth.

Ubiquitin-like with PHD and ring finger domains 1 (UHRF1), known as ICB90 or Np95, has been found to be overexpressed in numerous cancers. In this study, we evaluated the expression level of UHRF1 in ovarian cancer. UHRF1 levels in paired ovarian cancer tissues and adjacent normal tissues from 80 ovarian cancer patients were detected using relative quantitatively PCR and Western blot. Small interfering RNA (siRNA) was introduced in two human ovarian cancer cell lines (SKOV-3 and OVCAR-3) to downregulate the expression of UHRF1. The proliferation of siRNA-treated cells was examined using cell counting kit-8 (CCK-8) assay. The growth of these cells showed a remarkable decrease. Moreover, flow cytometric and Hoechst 33342 assays were used to detect the apoptosis. The diagnostic value of UHRF1 messenger RNA (mRNA) expression in ovarian cancer was estimated by receiver-operator characteristic (ROC) curve. The correlation between UHRF1 mRNA expression and clinicopathologic features of ovarian cancer patients was evaluated by χ (2) test. Our results demonstrated that both UHRF1 mRNA and protein were highly expressed in ovarian cancer tissues and significantly higher than that in adjacent normal tissues. Moreover, the inhibition of UHRF1 may lead to cells to undergo apoptosis. Thus, UHRF1 could act as a new oncogenic factor in ovarian cancer and be a potential molecular target for ovarian cancer gene therapy.

BTG1 expression correlates with pathogenesis, aggressive behaviors and prognosis of gastric cancer: a potential target for gene therapy.

Here, we found that BTG1 overexpression inhibited proliferation, migration and invasion, induced G2/M arrest, differentiation, senescence and apoptosis in BGC-823 and MKN28 cells (p < 0.05). BTG1 transfectants showed a higher mRNA expression of Cyclin D1 and Bax, but a lower mRNA expression of cdc2, p21, mTOR and MMP-9 than the control and mock (p < 0.05). After treated with cisplatin, MG132, paclitaxel and SAHA, both BTG1 transfectants showed lower mRNA viability and higher apoptosis than the control in both time- and dose-dependent manners (p < 0.05) with the hypoexpression of chemoresistance-related genes (slug, CD147, GRP78, GRP94, FBXW7 TOP1, TOP2 and GST-π). BTG1 expression was restored after 5-aza-2'-deoxycytidine treatment in gastric cancer cells. BTG1 expression was statistically lower in gastric cancer than non-neoplastic mucosa and metastatic cancer in lymph node (p < 0.05). BTG1 expression was positively correlated with depth of invasion, lymphatic and venous invasion, lymph node metastasis, TNM staging and worse prognosis (p < 0.05). The diffuse-type carcinoma showed less BTG1 expression than intestinal- and mixed-type ones (p < 0.05). BTG1 overexpression suppressed tumor growth and lung metastasis of gastric cancer cells by inhibiting proliferation, enhancing autophagy and apoptosis in xenograft models. It was suggested that down-regulated BTG1 expression might promote gastric carcinogenesis partially due to its promoter methylation. BTG1 overexpression might reverse the aggressive phenotypes and be employed as a potential target for gene therapy of gastric cancer.

G-protein-coupled receptor 137 accelerates proliferation of urinary bladder cancer cells in vitro.

Urinary bladder cancer is a worldwide concern because of its level of incidence and recurrence. To search an effective therapeutic strategy for urinary bladder cancer, it is important to identify proteins involved in tumorigenesis that could serve as potential targets for diagnosis and treatment. G-protein-coupled receptors (GPRs) constitute a large protein family of receptors that sense molecules outside the cell and activate signal transduction pathways and cellular responses inside the cell. GPR137 is a newly discovered human gene encoding orphan GPRs. In this study, we aimed to investigate the physiological role of GPR137 in urinary bladder cancer. The effect of GPR137 on cell growth was examined via an RNA interference (RNAi) lentivirus system in two human urinary bladder cancer cell lines BT5637 and T24. Lentivirus-mediated RNAi could specifically suppressed GPR137 expression in vitro, resulting in alleviated cell viability and impaired colony formation, as well as blocks G0/G1 and S phases of the cell cycle. These results suggested GPR137 as an essential player in urinary bladder cancer cell growth, and it may serve as a potential target for gene therapy in the treatment of urinary bladder cancer.