Revealing underlying regulatory mechanisms of LINC00313 in Osimertinib-resistant LUAD cells by ceRNA network analysis.

BACKGROUND: Osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), is the preferred treatment for EGFR-mutated lung cancer. However, acquired resistance inevitably develops. While non-coding RNAs have been implicated in lung cancer through various functions, the molecular mechanisms responsible for osimertinib resistance remain incompletely elucidated. METHODS: RNA-sequencing technology was employed to determine differentially expressed lncRNAs (DE-lncRNAs) and mRNAs (DE-mRNAs) between H1975 and H1975OR cell lines. Starbase 2.0 was utilized to predict DE-lncRNA and DE-mRNA interactions, constructing ceRNA networks. Subsequently, functional and pathway enrichment analysis were performed on target DE-mRNAs to identify pathways associated with osimertinib resistance. Key target DE-mRNAs were then selected as potential risk signatures for lung adenocarcinoma (LUAD) prognostic modeling using multivariate Cox regression analyses. The Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and immunohistochemistry staining were used for result validation. RESULTS: Functional analysis revealed that the identified DE-mRNAs primarily enriched in EGFR-TKI resistance pathways, especially in the PI3K/Akt signaling pathway, where their concerted actions may lead to osimertinib resistance. Specifically, upregulation of LINC00313 enhanced COL1A1 expression by acting as a miR-218-5p sponge, triggering an upstream response that activates the PI3K/Akt pathway, potentially contributing to osimertinib resistance. Furthermore, the expressions of LINC00313 and COL1A1 were validated by qRT-PCR, and the activation of the PI3K/Akt pathway was confirmed by immunohistochemistry staining. CONCLUSIONS: Our results suggest that the LINC00313/miR-218-5p/COL1A1 axis potentially contributes to osimertinib resistance through the PI3K/Akt signaling pathway, providing novel insights into the molecular mechanisms underlying acquired osimertinib resistance in LUAD. Additionally, our study may aid in the identification of potential therapeutic targets for overcoming resistance to osimertinib.

Study of Reasonable Grouting Pressure in the Process of Measuring Coal Seam Gas Pressure and Application.

Coal seam gas pressure is an important index to evaluate the risk of coal outbursts. The accuracy of measurement is closely related to the quality of hole sealing, and reasonable grouting pressure is one of the key factors to determine the quality of hole sealing. To obtain a reasonable grouting pressure, a mathematical model for slurry flow was established based on the relationship between the seepage law of the slurry and the properties of the borehole surrounding a rock. According to the conditions of the working face 11111 of the coal seam Ji15-17 in Pingdingshan No. 13 Coal Mine, the reasonable grouting pressure in the process of hole sealing and pressure measurement were simulated by COMSOL multiphysics numerical simulation software. After comparing the pressure distribution and slurry diffusion characteristics in the borehole under different grouting pressures, it is concluded that the reasonable grouting pressure is 4 MPa. When 4 MPa grouting pressure to seal the hole is used during actual engineering verification, the measured gas pressure is 2.7 MPa, which is more accurate than the result obtained under conditions of sealing with normal pressure grouting.

Study on the emergency capacity of coal mine enterprises in Longdong Area based on D-FAHP method.

Emergency capability assessment is a complex system with multiple factors, variables and levels. Incomplete and uncertain assess information often occurs during assessment. Based on this, a method combining D-number theory and fuzzy analytic Hierarchy process (FAHP) is proposed to study the emergency capacity of coal enterprises in Longdong area. On the basis of analyzing the limitation of D-S evidence theory, the D-number theory was optimized and improved. According to the principles of systematicness, feasibility, scientificity and timeliness, a hierarchical structure model of enterprise emergency capability assessment was constructed from the perspective of pre-incident, mid-incident and post-incident, which consisted of 4 first-level indicators and 18 s-level indicators. The weight and importance of the assessment index of emergency response capability are calculated by organically integrating the D-number preference relation with the hierarchy structure. Combined with the assessment results of experts, a quantitative analysis and evaluation of the emergency response capacity of a coal enterprise was conducted by using FAHP. The comprehensive score of the enterprise's emergency response capability was 80.45, and the level of emergency response capacity was "good". The research results show that the D-FAHP method has high reliability in evaluating the emergency response capability of coal enterprises, avoiding the impact of uncertain and incomplete information on the assessment results. This can not only effectively identify the weak links in emergency management, but also meet the emergency decision-making needs of enterprises in the emergency state, which has important guiding significance to improve the ability and level of enterprise emergency management.

Analysis of the lncRNA-miRNA-mRNA Network Reveals a Potential Regulatory Mechanism of EGFR-TKI Resistance in NSCLC.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are widely used for patients with EGFR-mutated lung cancer. Despite its initial therapeutic efficacy, most patients eventually develop drug resistance, which leads to a poor prognosis in lung cancer patients. Previous investigations have proved that non-coding RNAs including long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs) contribute to drug resistance by various biological functions, whereas how they regulate EGFR-TKI resistance remains unclear. In this study, we examined gene expression using the microarray technology on gefitinib-resistant NSCLC cells to obtain differentially expressed (DE) lncRNAs and mRNAs. A total of 45 DE-lncRNAs associated with overall survival and 1799 target DE-mRNAs were employed to construct a core lncRNA-miRNA-mRNA network to illustrate underlying molecular mechanisms of how EGFR-TKI resistance occurs in NSCLC. We found that target DE-mRNAs were mainly enriched in pathways involved in EGFR-TKI resistance, especially the target DE-mRNAs regulated by LINC01128 were significantly enriched in the PI3K/Akt signaling pathway, where the synergy of these target DE-mRNAs may play a key role in EGFR-TKI resistance. In addition, downregulated LINC01128, acting as a specific miRNA sponge, decreases PTEN via sponging miR-25-3p. Furthermore, signaling reactions caused by the downregulation of PTEN would activate the PI3K/Akt signaling pathway, which may lead to EGFR-TKI resistance. In addition, a survival analysis indicated the low expression of LINC01128, and PTEN is closely related to poor prognosis in lung adenocarcinoma (LUAD). Therefore, the LINC01128/miR-25-3p/PTEN axis may promote EGFR-TKI resistance via the PI3K/Akt signaling pathway, which provides new insights into the underlying molecular mechanisms of drug resistance to EGFR-TKIs in NSCLC. In addition, our study sheds light on developing novel therapeutic approaches to overcome EGFR-TKI resistance in NSCLC.

MicroRNA­124 negatively regulates chloride intracellular channel 1 to suppress the migration and invasion of liver cancer cells.

The dysregulation of microRNAs (miRNAs) is associated with the development and progression of a variety of cancers, including liver cancer. Aberrant expression of miRNA (miR)­124 has been demonstrated in liver cancer, but its functional mechanism in liver cancer is still largely unknown. Metastasis of liver cancer is one of the most common causes of mortality. The present study showed that miR­124 inhibited the proliferation, migration and invasion of liver cancer cells. Furthermore, chloride intracellular channel 1 (CLIC1) was identified as a novel target of miR­124 in liver cancer cells. Overexpression of miR­124 reduced CLIC1 expression at both the protein and mRNA levels in liver cancer cells. Downregulation of CLIC1 decreased the migration and invasion of liver cancer cells without affecting cell proliferation. Taken together, these results showed that CLIC1 is a critical target for miR­124­mediated inhibitory effects on cell migration and invasion. Thus, miR­124 or suppression of CLIC1 may have diagnostic value and therapeutic potential for the treatment of human liver cancer.

Integration of microRNA-mRNA profiles and pathway analysis of plant isoquinoline alkaloid berberine in SGC-7901 gastric cancers cells.

PURPOSE: Berberine (BBR) is a traditional Chinese medicine normally used for gastroenteritis, and recent research found that it could fight against tumors. In this study, we focused on integrating miRNA sequencing and RNA sequencing of SGC-7901 gastric cancer cells treated by BBR to elucidate their underlying mechanisms. MATERIALS AND METHODS: WST-1 assay and flow cytometry were used to check the effects of BBR on SGC-7901. miRNA sequencing and RNA sequencing were used to establish the miRNA and mRNA profiles of BBR-treated SGC-7901. RESULTS: The results showed that BBR could inhibit the proliferation of SGC-7901 cells and induce G1 arrest in cell cycle phase and apoptosis. A total of 1,960 upregulated genes and 4,837 downregulated genes were identified in the RNA sequencing and 347 upregulated and 93 downregulated miRNAs in the miRNA sequencing. A total of 78 novel miRNAs were also found. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis showed that the genes were related to pathways in cancer and metabolism. We also analyzed the miRNA-mRNA network of genes grouped into cell cycle, apoptosis, inflammation, metabolism, cell junction, acetylization process, TGF-ß pathway, and Wnt signaling pathway. CONCLUSION: BBR could inhibit the proliferation of SGC-7901 cells and induce apoptosis. Integrated analysis of microRNA-mRNA profiles is a promising approach to validate gene expression patterns associated with malignant phenotype and study the mechanisms of anticancer.

MicroRNA-33a-5p suppresses growth of osteosarcoma cells and is downregulated in human osteosarcoma.

A body of evidence has indicated that microRNAs (miRNAs) may have significant roles in cancer. Aberrant expression of miRNAs has frequently been observed in various human malignancies, including osteosarcoma (OS). However, the roles of miRNAs in OS remain poorly understood. In the present study, high-throughput deep sequencing was performed to screen for deregulated miRNAs in OS. Screening identified 310 miRNAs which were significantly overexpressed and 41 miRNAs which were significantly downregulated (>2-fold) in OS samples, compared with adjacent non-tumor bone tissues. Among these miRNAs, miR-33a-5p was notably downregulated. TaqMan reverse transcription-polymerase chain reaction analysis further verified that miR-33a-5p expression was significantly reduced in a large cohort of human OS samples. Enhancing miR-33a-5p expression via transfection with miR-33a-5p precursor significantly inhibited OS cell growth, suggesting potential antitumor properties of miR-33a-5p. The results of the present study provide novel insights into the miRNAs involved in OS, and suggest that miR-33a-5p may function as a tumor suppressor in OS. Therefore, miR-33a-5p may be able to serve as a diagnostic and therapeutic target for OS treatment.

Evaluation of the novel three-dimensional porous poly (L-lactic acid)/nano-hydroxyapatite composite scaffold.

To determine the optimal ratio of nano-hydroxyapatite (n-HA) to polylactic acid (PLLA) in the novel three-dimensional porous PLLA/n-HA composite scaffolds, low-temperature rapid prototyping technology was employed to fabricate the composite materials with different n-HA contents. Mechanical properties and degradation behaviors of the composites were examined, and the scaffold microstructure and n-HA dispersion were observed by scanning electron microscope (SEM). Mechanical tests demonstrated that the tensile strength of the composite material gradually decreased with an increase in n-HA content. When the n-HA content reached 20 wt%, the bending strength of the composite material peaked at 138.5 MPa. SEM images demonstrated that the optimal content of n-HA was 20 wt% as the largest interconnected pore size that can be seen, with a porosity as high as 80%. In vitro degradation experiments demonstrated that the pH value of the material containing solution gradually decreased in a time-dependent manner, with a simultaneous weakening of the mechanical properties. In vitro study using rat osteoblast cells showed that the composite scaffolds were biocompatible; the 20 wt% n-HA scaffold offered particular improvement to rat osteoblast cell adhesion and proliferation compared to other compositions. It was therefore concluded that 20 wt% n-HA is the optimal nano-hydroxyapatite (n-HA) to polylactic acid (PLLA) ratio, with promise for bone tissue engineering.

Genome-wide uncovering of STAT3-mediated miRNA expression profiles in colorectal cancer cell lines.

Colorectal cancer (CRC) is one of the most common malignancies resulting in high mortality worldwide. Signal transducer and activator of transcription 3 (STAT3) is an oncogenic transcription factor which is frequently activated and aberrantly expressed in CRC. MicroRNAs (miRNAs) are a class of small noncoding RNAs which play important roles in many cancers. However, little is known about the global miRNA profiles mediated by STAT3 in CRC cells. In the present study, we applied RNA interference to inhibit STAT3 expression and profiled the miRNA expression levels regulated by STAT3 in CRC cell lines with deep sequencing. We found that 26 and 21 known miRNAs were significantly overexpressed and downexpressed, respectively, in the STAT3-knockdown CRC cell line SW480 (SW480/STAT3-siRNA) compared to SW480 transfected with scrambled siRNAs (SW480/siRNA-control). The miRNA expression profiling was then validated by quantitative real-time PCR for selected known miRNAs. We further predicted the putative target genes for the dysregulated miRNAs and carried out functional annotation including GO enrichment and KEGG pathway analysis for selected miRNA targets. This study directly depicts STAT3-mediated miRNA profiles in CRC cells, which provides a possible way to discover biomarkers for CRC therapy.

MicroRNA-223 functions as an oncogene in human colorectal cancer cells.

Aberrant microRNA (miRNA) expression has been frequently observed in colorectal cancer (CRC), the third most common human cancer in the world. However, the roles of miRNAs in CRC remain poorly understood. The present study explored, identified and characterized the miRNAs that correlate with CRC progression. Deregulated level of microRNA-223 (miR-223) was screened out by miRNA microarray in colorectal tumor tissues and further confirmed by quantitative real-time PCR in a large cohort of CRC samples (n=90). After silencing miR-223 by artificial anti­miR-223 (miR-223-inhibitor), WST-1 and colony formation assays were employed to assess cell proliferation, and cell migration and invasion were evaluated by wound healing test and Transwell assays, respectively. Compared with adjacent non-tumor tissues, 22 miRNAs were screened out in CRC tissues with significance (>2-fold), of which 13 were upregulated and 9 were downregulated. miR-223 is one of the noticeably upregulated miRNAs. Large cohort CRC sample analyses showed that a higher level of miR-223 correlated with a higher clinical stage. Reducing miR-223 expression resulted in a decreased cell proliferation, migration and invasion in CRC cells. miR-223 functions as an oncomiR in CRC, therefore serving as a potential diagnostic and therapeutic target for the treatment of CRC.

MicroRNA-124 suppresses growth of human hepatocellular carcinoma by targeting STAT3.

The aberrant expression of microRNAs is associated with development and progression of cancers. Down-regulation of miR-124 has been demonstrated in the hepatocellular carcinoma (HCC), but the underlying mechanism by which miR-124 suppresses tumorigenesis in HCC remains elusive. In this study, we found that miR-124 suppresses the tumor growth of HCC through targeting the signal transducers and activators of transcription 3 (STAT3). Overexpression of miR-124 suppressed proliferation and induced apoptosis in HepG-2 cells. Luciferase assay confirmed that miR-124 binding to the 3'-UTR region of STAT3 inhibited the expression of STAT3 and phosphorylated STAT3 proteins in HepG-2 cells. Knockdown of STAT3 by siRNA in HepG-2 cells mimicked the effect induced by miR-124. Overexpression of STAT3 in miR-124-transfected HepG-2 cells effectively rescued the inhibition of cell proliferation caused by miR-124. Furthermore, miR-124 suppressed xenograft tumor growth in nude mice implanted with HepG-2 cells by reducing STAT3 expression. Taken together, our findings show that miR-124 functions as tumor suppressor in HCC by targeting STAT3, and miR-124 may therefore serve as a biomarker for diagnosis and therapeutics in HCC.

MiR-124 suppresses growth of human colorectal cancer by inhibiting STAT3.

Emerging evidence indicate that microRNAs (miRNAs) may play important roles in cancer. Aberrant expression of miRNAs has been frequently identified in different human malignancies, including colorectal cancer (CRC). However, the mechanism by which deregulated miRNAs impact the development of CRC remains largely elusive. In this study, we show that miR-124 is significantly down-regulated in CRC compared to adjacent non-tumor colorectal tissues. MiR-124 suppresses the expression of STAT3 by directly binding to its 3'-untranslated region (3'-UTR). Overexpression of miR-124 led to increased apoptosis of CRC cells and reduced tumor growth in vitro and in vivo. Knocking down STAT3 expression by specific siRNA suppressed the growth of CRC cells in vitro and in vivo, resembling that of miR-124 overexpression. Moreover, overexpression of STAT3 in miR-124-transfected CRC cells effectively rescued the inhibition of cell proliferation caused by miR-124. These data suggest that miR-124 serves as a tumor suppressor by targeting STAT3, and call for the use of miR-124 as a potential therapeutic tool for CRC, where STAT3 is often hyper-activated.

Genome-wide analysis of miRNA signature differentially expressed in doxorubicin-resistant and parental human hepatocellular carcinoma cell lines.

Chemotherapy regiments have been widely used in the treatment of a variety of human malignancies including hepatocellular carcinoma (HCC). A major cause of failure in chemotherapy is drug resistance of cancer cells. Resistance to doxorubicin (DOX) is a common and representative obstacle to treat cancer effectively. Individual microRNA (miRNA) has been introduced in the evolution of DOX resistance in HCC in recent studies. However, a global and systematic assessment of the miRNA expression profiles contributing to DOX resistance is still lacking. In the present study, we applied high-throughput Illumina sequencing to comprehensively characterize miRNA expression profiles in both human HCC cell line (HepG2) and its DOX-resistant counterpart (HepG2/DOX). A total of 269 known miRNAs were significantly differentially expressed, of which 23 were up-regulated and 246 were down-regulated in HepG2/DOX cells, indicating that part of them might be involved in the development of DOX resistance. In addition, we have identified 9 and 13 novel miRNAs up- and down-expressed significantly in HepG2/DOX cells, respectively. miRNA profiling was then validated by quantitative real-time PCR for selected miRNAs, including 22 known miRNAs and 6 novel miRNAs. Furthermore, we predicted the putative target genes for the deregulated miRNAs in the samples. Function annotation implied that these selected miRNAs affected many target genes mainly involved in MAPK signaling pathway. This study provides us a general description of miRNA expression profiling, which is helpful to find potential miRNAs for adjunct treatment to overcome DOX resistance in future HCC chemotherapy.

Pharmacokinetics of combined gene therapy expressing constitutive human GM-CSF and hyperthermia-regulated human IL-12.

BACKGROUND: An adenovirus that expresses both interleukin (IL)-12 and granulocyte-macrophage colony-stimulating-factor (GM-CSF) has been proven to be very effective in treating several tumors, but causes serious normal tissue toxicities. METHODS: In this study, a novel adenoviral vector was constructed by placing the human GM-CSF gene under the control of the CMV-IE promoter and human IL-12 gene under the control of heat shock protein 70B gene promoter. Both hGM-CSF and hIL-12 expressions in virus-infected tumor cells were analyzed in vitro and in vivo when underlying single or multiple rounds of hyperthermia. RESULTS: We observed constitutive high expression of human GM-CSF and heat-induced expression of human IL-12 after a single round of hyperthermia post viral infection. The heat-induced hIL-12 expression exhibited a pulse-like pattern with a peak at 24 hrs followed by a decline 48 hrs post heat stress. Repeated heat treatment was more effective in inducing hIL-12 expression than a one-time heat treatment. Interestedly, we also observed that constitutive expression of hGM-CSF could be stimulated by heat stress in tested tumor cells. CONCLUSION: Our study provided a novel strategy for combined gene therapy that allows constitutive expression of a non-toxic gene such as GM-CSF and heat-induced expression of a toxic gene such as IL-12. In addition, our study also showed that hyperthermia can be used to trigger gene expression in temporal and special manner.

The study on biocompatibility of porous nHA/PLGA composite scaffolds for tissue engineering with rabbit chondrocytes in vitro.

OBJECTIVE: To examine the biocompatibility of a novel nanohydroxyapatite/poly[lactic-co-glycolic acid] (nHA/PLGA) composite and evaluate its feasibility as a scaffold for cartilage tissue engineering. METHODS: Chondrocytes of fetal rabbit were cultured with nHA/PLGA scaffold in vitro and the cell viability was assessed by MTT assay first. Cells adhering to nHA/PLGA scaffold were then observed by inverted microscope and scanning electron microscope (SEM). The cell cycle profile was analyzed by flow cytometry. RESULTS: The viability of the chondrocytes on the scaffold was not affected by nHA/PLGA comparing with the control group as it was shown by MTT assay. Cells on the surface and in the pores of the scaffold increased in a time-dependent manner. Results obtained from flow cytometry showed that there was no significant difference in cell cycle profiles between the coculture group and control (P > 0.05). CONCLUSION: The porous nHA/PLGA composite scaffold is a biocompatible and good kind of scaffold for cartilage tissue engineering.

A novel immunocompetent murine tumor model for the evaluation of RCAd-enhanced RDAd transduction efficacy.

Low gene transfer rate in tumors, high dose-induced acute inflammatory response, and lack of an immunocompetent preclinical animal model to accurately reflect the therapeutic efficacy are prominent reasons for the lack of clinical success of adenoviral (Ad) vectors. In this study, we tested whether human replication-competent adenovirus (RCAd) can replicate in T739 mouse bladder transitional tumor cells (BTT) and lung adenocarcinoma cells (LA795), and whether RCAd can enhance the transduction rate and transgene expression of human replication defective adenoviruses (RDAd) in these tumor cells in vitro and in vivo. We demonstrated that human RCAd exhibited good infectability and cytopathologic effects in mouse BTT and LA795 cells, which was comparable to that in A549 and NCIH460 human tumor cells. In contrast, no infectability and cytopathologic effects were observed in other three mouse tumor cells such as 4T1, B16, and Lewis cells. The combined use of RCAd with RDAd significantly enhanced RDAd transduction efficiency in BTT and LA795 tumor cells in vitro and in vivo. When BTT and LA795 cells were co-infected with RDAd Ad-EGFP and RCAd, a large amount of E1a expression and 2-3 orders of increases in Ad-EGFP genomic DNA were observed. In contrast, the expression of the late gene Hexon is very low, which may explain ineffective packaging of viral particles. In conclusion, our study provided a novel immunocompetent animal model which is useful for evaluating RCAd infectability, cytopathy, and replication. The combined use of RCAd and RDAd provided a new solution for cancer gene therapy.

A novel conditionally replicating "armed" adenovirus selectively targeting gastrointestinal tumors with aberrant wnt signaling.

Using conditionally replicating adenoviral vectors (CRAds) is a promising strategy in the treatment of solid tumors. The prospective of this study was to design a novel CRAd for the treatment of gastrointestinal cancer and show its efficacy in vitro, as well as in vivo. To determine if aberrant wnt signaling in tumor cells can be used to selectively drive viral replication, we analyzed six colorectal and hepatocellular cell lines, as well as 13 colorectal tumors and 17 gastric tumors, for ß-catenin mutation status or aberrant wnt signaling, both of which were found frequently. Based on these findings, a novel CRAd (Ad5F11.wnt-E1A-hIL24) containing an E1A expression cassette driven by an artificial wnt promoter and delivering an apoptosis-inducing gene, interleukin-24 (IL24), was engineered. To enhance infection efficiency, the virus was pseudotyped by replacing adenovirus serotype 5 (Ad5) with Ad11 fiber. Ad5F11.wnt-E1A-hIL24 virus exhibited high selectivity toward cells with aberrant wnt signaling both in vitro and in mouse xenograft tumors. Transduction efficiency was significantly improved compared with that of nonpseudotyped control viruses. The proliferation of tumor cell lines, as well as tumor growth, in mouse xenografts could be profoundly inhibited by viral infection with Ad5F11.wnt-E1A-hIL24. The therapeutic effect was associated with increased apoptosis through caspase-3 activation. In addition, Ad5F11b vector exhibited a more favorable biodistribution, blood clearance, and transgene expression compared with conventional Ad5 vector after systemic or intratumoral injection in human gastrointestinal cancer xenografts. We think that our approach is a promising strategy in the treatment of gastrointestinal cancer, warranting further clinical investigation.

A novel oncolytic adenovirus expressing Escherichia coli cytosine deaminase exhibits potent antitumor effect on human solid tumors.

PURPOSE: This study aims to generate a more potent oncolytic adenovirus, Ad.hTERT-E1A/CMV-CD, which combines therapeutic gene and oncolytic effect. METHODS: A human telomerase reverse transcriptase (hTERT) gene promoter was used to regulate the expression of adenoviral immediate-early gene 1A (E1A) to induce selective replication of recombinant adenovirus in tumor cells. To further enhance antitumor effect, a cytomegalovirus (CMV) promoter-driven Escherichia coli cytosine deaminase (CD) gene expression cassette was further incorporated into E1 region and the antitumor effect of this novel adenovirus was evaluated in vitro and in vivo. RESULTS: Ad.hTERT-E1A/CMV-CD was capable to selectively replicate and lyse in various human tumor cell lines, including NCIH460, SW1990, and HeLa, while causing no damage to primary fibroblasts. The combined therapy of Ad.hTERT-E1A/CMV-CD with prodrug 5-fluorocytosine (5-FC) elicited a greater killing effect on tumor cells than Ad.hTERT-E1A/CMV-CD alone, and it synergistically suppressed tumor growth in BALB/c nude mice bearing human lung tumor. CONCLUSIONS: As telomerase is reactivated in a broad spectrum of tumors and prodrug 5-FC is much safe than its metabolized 5-fluorouracil, a chemotherapeutic agent in the treatment of many malignancies, Ad.hTERT-E1A/CMV-CD in combination with 5-FC may be a potential strategy for the treatment of a wide range of solid tumors.

Functional elucidation and methylation-mediated downregulation of ITGA5 gene in breast cancer cell line MDA-MB-468.

Expression level of integrin alpha5 in tumor cells has been indicated to be involved in cell proliferation and organ-specific metastasis. We previously demonstrated that ITGA5 expression was downregulated in the high invasive MDA-MB-468 cells compared with other breast cancer cell lines. In this study, we found that the methylation status in the region around transcriptional start site of ITGA5 gene was increased in MDA-MB-468 cells. Overexpression of integrin alpha5 on MDA-MB-468 cells resulted in cell growth inhibition, which could be reversed by adhesion to fibronectin. Cell adhesion and spreading to fibronectin was enhanced after ITGA5 was overexpressed in MDA-MB-468 cells, while cell migration was attenuated. Knockdown of ITGA5 in MCF-7 cells led to cell growth inhibition but had little influence on cell migration. These findings indicated the diverse roles of ITGA5 expression in breast cancer cells.

Potent anti-tumor activity of telomerase-dependent and HSV-TK armed oncolytic adenovirus for non-small cell lung cancer in vitro and in vivo.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the leading cause of cancer related mortality, any improvements in therapeutic strategies are urgently required. In this study we generated a novel 'suicide gene' armed oncolytic adenoviral vector and investigated its antitumor effect both in vitro and in vivo. METHODS: Since the up-regulated expression of human telomerase reverse transcriptase (hTERT) is a hallmark of alltypes of NSCLC, we chose hTERT promoter to transcriptionally control E1A gene expression to obtain adenoviral replication in NSCLC. In order to further enhance anti-tumor effect of this oncolytic adenoviral vector, we inserted a 'suicide gene' i.e. Herpes Simplex Virus Thymidine Kinase (HSV-TK) into oncolytic adenoviral vector to engineer a novel armed oncolytic adenoviral vector 'Ad.hTERT-E1A-TK'. RESULTS: Ad.hTERT-E1A-TK efficiently killed different types of tumor cells including two types of NSCLC cells in vitro, causing no damage to normal primary fibroblasts. Furthermore, Ad.hTERT-E1A-TK infection combined with administration of prodrug gancyclovir (GCV) resulted in more potent cytotoxicity on NSCLC cells, and synergistically suppressed human NSCLC tumor growth in nude mice. CONCLUSION: The results from this study showed that Ad.hTERT-E1A-TK/GCV could be a potent but safe anti-tumor strategy for NSCLC biotherapy.