Cell Line T84 Research Articles

Extracts from peppermint leaves, lemon balm leaves and in particular angelica roots mimic the pro-secretory action of the herbal preparation STW 5 in the human intestine

AimThe herbal preparation STW 5 contains fresh plant extracts from bitter candytuft whole plant, extracts from greater celandine herb, angelica root, lemon balm leaves, peppermint leaves, caraway fruit, liquorice root, chamomile flower and milk thistle fruit. We recently reported that STW 5 increased intestinal chloride secretion and proposed that this action may be involved in its clinical efficacy in the treatment of irritable bowel syndrome. The aim of this study was to identify the extracts responsible for the secretory action in order to provide the basis to develop novel target oriented herbal combinations. MethodsWe used the Ussing chamber voltage clamp technique to study the effects of individual extracts of STW 5 on short circuit current (Isc, reflecting electrogenic ion transport across epithelial cells) in mucosal/submucosal preparations of human small or large intestinal specimens and the human epithelial cell line T84. ResultsSTW 5 at concentrations of 512 µg/ml and 5120 µg/ml evoked an increase in Isc. The increase at the lower concentration was due to pro-secretory effects of angelica which were nerve mediated. The increase at the higher concentration was additionally mimicked by peppermint and lemon balm. The remaining extracts did not influence ISC in the large intestine. The results were similar in T84 cells except that angelica had no effect while chamomile induced secretion. These pro-secretory effects were reduced by adenylate cyclase inhibitor MDL-12330A, cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTRinh-172 and calcium activated chloride channels blocker 4-acetamido-4-isothiocyanatostilbene-2,2-disulphonic acid (SITS). Liquorice decreased ISC only in small intestine which was reversed by the epithelial sodium channel blocker amiloride. ConclusionsResults suggested that the pro-secretory action of STW 5 is mainly due to angelica with lesser contribution of peppermint and lemon balm. Their effects involve activation of cAMP- and Ca++-activated Cl− channels. We suggest that peppermint, lemon balm and in particular angelica may be the basis to develop novel herbal preparations to specifically treat secretory disorder based on impaired epithelial secretion, such as constipation.

Long non-coding RNA MEG3 induces renal cell carcinoma cells apoptosis by activating the mitochondrial pathway.

This study aimed to examine the effect of long non-coding RNA (LncRNA) MEG3 on the biological behaviors of renal cell carcinoma (RCC) cells 786-0 and the possible mechanism. MEG3 expression levels were detected by RT-qPCR in tumor tissues and adjacent non-tumor tissues from 29 RCC patients and in RCC lines 786-0 and SN12 and human embryonic kidney cell line 293T. Plasmids GV144-MEG3 (MEG3 overexpression plasmid) and GV144 (control plasmid) were stably transfected into 786-0 cells by using lipofectamine 2000. Cell viabilities were determined by MTT, cell apoptosis rates by flow cytometry following PE Annexin V and 7AAD staining, apoptosis-related protein expressions by Western blotting, and Bcl-2 mRNA by RT-qPCR in the transfected cells. The results showed that MEG3 was evidently downregulated in RCC tissues (P<0.05) and RCC cell lines (P<0.05). The viabilities of 786-0 cells were decreased significantly after transfection with GV144-MEG3 for over 24 h (P<0.05). Consistently, the apoptosis rate was significantly increased in 786-0 cells transfected with GV144-MEG3 for 48 h (P<0.05). Furthermore, overexpression of MEG3 could reduce the expression of Bcl-2 and procaspase-9 proteins, enhance the expression of cleaved caspase-9 protein, and promote the release of cytochrome c protein to cytoplasm (P<0.05). Additionally, Bcl-2 mRNA level was declined by MEG3 overexpression (P<0.05). It was concluded that MEG3 induces the apoptosis of RCC cells possibly by activating the mitochondrial pathway.

Synthesis and evaluation of novel chitosan derivatives for gene delivery

A series of novel water soluble chitosan derivatives as gene vectors was synthesized. The delivery systems were tested for their ability to form complexes with plasmid DNA by utilizing agarose gel electrophoresis, particle size analysis, zeta potential measurement and scanning electron microscopy. Furthermore, cytotoxicity of chitosan derivatives and transfection efficiency of polyplexes were evaluated in vitro. The experimental results showed that the novel chitosan derivatives had lower cytotoxicity, good DNA condensation, and higher transfection efficiencies compared to chitosan in both 293T and HeLa cell lines. It was indicated that these chitosan derivatives were promising candidates for non-viral gene vectors

Antibacterial and Antiparasitic Activity of Manganese(I) Tricarbonyl Complexes with Ketoconazole, Miconazole, and Clotrimazole Ligands

Five manganese(I) tricarbonyl complexes of the general formula [Mn(CO)3(bpyR,R)(azole)]PF6 with R = H, COOCH3, and azole = ketoconazole (ktz), miconazole (mcz), and clotrimazole (ctz) were synthesized and fully charaterized, including X-ray structure analysis for the ctz compound. The antibacterial activity on a panel of eight Gram-positive and Gram-negative bacterial strains was determined. While there was no effect on the latter microorganisms, the ctz complex showed submicromolar activity on Staphylococcus aureus and S. epidermidis with MIC values of 0.625 μM. Antiparasitic activity was investigated on Leishmania major and Trypanosoma brucei. Coordination of the organic azole drugs to the Mn(CO)3 moiety led to complexes with low micromolar IC50 values, but their potential for antileishmanial therapy is low due to comparable toxicity on mammalian cell lines 293T and J774.1. In contrast, the antitrypanosomal activity is much more promising, and the most potent compound incorparting the ktz ligand has an ...

Protein domains of APOL1 and its risk variants

Increasing lines of evidence have demonstrated that the development of higher rates of non-diabetic glomerulosclerosis (GS) in African Americans can be attributed to two coding sequence variants (G1 and G2) in the Apolipoprotein L1 (APOL) gene. Recent studies indicate that the gene products of these APOL1 risk variants have augmented toxicity to kidney cells. However, the biological characteristics of APOL1 and its risk variants are not well elucidated. The APOL1 protein can be divided into several functional domains, including signal peptide (SP), pore forming domain (PFD), membrane address domain (MAD), and SRA-interacting domain. To investigate the relative contribution of each domain to cell injury, we constructed a serial expression vectors to delete or express each domain. These vectors were transfected into the human embryonic kidney cell line 293T, and then compared the cytotoxicity. In addition, we conducted studies in which APOL1 wild type (G0) was co-transfected in combination with G1 or G2 to see whether G0 could counteract the toxicity of the risk variants. The results showed that deleting the SP did not abolish the toxicity of APOL1, though deletion of 26 amino acid residues of the mature peptide at the N-terminal partially decreased the toxicity. Deleting PFD or MAD or SRA-interacting domain abolished toxicity, while, overexpressing each domain alone could not cause toxicity to the host cells. Deletion of the G2 sites while retaining G1 sites in the risk state resulted in persistent toxicity. Either deletion or exchanging the BH3 domain in the PFD led to complete loss of the toxicity in this experimental platform. Adding G0 to either G1 or G2 did not attenuate the toxicity of the either moiety. These results indicate that the integrity of the mature APOL1 protein is indispensable for its toxicity. Our study not only reveals the contribution of each domain of the APOL1 protein to cell injury, but also highlights some potential suggested targets for drug design to prevent or treat APOL1-associated nephropathy.

Effect of aquaporin 9 on proliferation, apoptosis, invasiveness and migration of HepG2 cells

To investigate the impact of aquaporin 9 (AQP9) on the proliferation,apoptosis,invasiveness and migration of hepatocellular carcinoma cells using the HepG2 cell line. A lentiviral vector targeting the coding region of human AQP9 was constructed. The recombinant lentiviral vector was harvested from the 293T cell line and transfected into the HepG2 cell line; resistant cell clones were selected with puromycin. Three groups of cells were established, including the CC group (control without lentiviral vector), the PWPI group (control with empty carrier virus), and the AQP9 overexpression group (experimental with the AQP9 recombinant virus). Transfection efficiency was validated by laser confocal microscopy.Expression of AQP9 was detected in the transfected HepG2 cells by westem blotting (protein) and real-time qPCR (mRNA). AQP9 effects on proliferation, migration, invasion and apoptosis of the HepG2 cell line were assessed by plate colony formation assay, woumd healing assay, transwell assay and flow cytometry. The green fluorescent protein of the recombinant lentiviral vector was appropriately distributed in the cell membrane. The AQP9 overexpression group showed significantly higher AQP9 mRNA and protein levels than the PWPI group and the CC group (both P < 0.01). Cells with AQP9 overexpression showed a lower colony formation rate (16.93±3.19% vs. CC group: 23.53±2.10% and PWPI group: 23.00±2.02%; F=6.46, P=0.032) and a lower overall apoptosis rate (44.96±3.53% vs. CC group:19.7±2.49% and PWPI group: 24.37±2.38%; F=66.88, P < 0.01). The AQP9 overexpression group also showed significantly higher number of cells in the G1 stage and significantly lower number of cells in the S stage (G1: 66.58±0.99% and S:15.25±1.81%), significantly smaller cell migration distance (P=0.01 < 0.05), and significantly suppressed invasiveness (17±8 vs. CC group:109+/-9 and PWPI group: 95±11; P=0.01 < 0.05). In HepG2 cells, AQP9 significantly reduces the migrative and invasive capabilities, induces cell apoptosis, and inhibits cell proliferation via cell cycle arrest at the G1/S phases.

Nidogen-1 is a common target of microRNAs MiR-192/215 in the pathogenesis of Hirschsprung's disease.

Recent studies have emphasized the important role of microRNA (miRNA) clusters and common target genes in disease progression. Despite the known involvement of the miR-192/215 family in many human diseases, its biological role in Hirschsprung disease (HSCR) remains undefined. In this study, we explored the role of the miR-192/215 family in the pathogenesis of HSCR. Quantitative real-time PCR and western blotting measured relative expression levels of miRNAs, mRNAs, and proteins in 80 HSCR patients and77 normal colon tissues. Targets were evaluated by dual-luciferase reporter assays, and the functional effects of miR-192/215 on human 293T and SH-SY5Y cells were detected by the Transwell assay, CCK8 assay and flow cytometry. MiR-192/215 was significantly down-regulated in HSCR tissue samples, and their knockdown inhibited cell migration and proliferation in the human 293T and SH-SY5Y cell lines. Nidogen 1 (NID1) was confirmed as a common target gene of miR-192/215 by dual-luciferase reporter gene assay and its expression was inversely correlated with that of miR-192/215 in tissue samples and cell lines. Silencing ofNID1 could rescue the extent of the suppressing effects by miR-192/215 inhibitor. The down-regulation of miR-192/215 may contribute to HSCR development by targeting NID1. We proposed the following cascade for the proposed mechanism of miR-192/215 in the pathogenesis of Hirschsprung disease (HSCR) by targeting Nidogen 1 (NID1). Aberrant expression of miR-192/215 inhibits cell migration and cell proliferation via NID1. We think the miR-192/miR-215/NID1 signaling pathway may play an important role in the pathogenesis of HSCR.

Single-step cloning-screening method: a new tool for developing and studying high-titer viral vector producer cells.

This article describes a novel method merging the cloning of viral vector producer cells with vector titer screening, allowing for screening 200-500 clones in 2 weeks. It makes use of a GFP separated into two fragments, S10 and S11 (Split GFP), fluorescing only upon transcomplementation. Producer cells carrying a S11 viral transgene are cloned in 96-well plates and co-cultured with target cells stably expressing S10. During the period of clone expansion, S11 viruses infect S10 target cells reconstituting the GFP signal. Transcomplemented fluorescence data provide direct estimation of the clone's productivity and can be analyzed in terms of density distribution, offering valuable information on the average productivity of the cell population and allowing the identification of high-producing clones. The method was validated by establishing a retrovirus producer from a nude cell line, in <3 months, inserting three vector constructs without clone selection or screening in between. Clones producing up to 10(8) infectious particles per ml were obtained, delivering optimal ratios of infectious-to-total particles (1 to 5). The method was additionally used to evaluate the production performance of HEK 293 and HEK 293T cell lines demonstrating that the latter sustains increased titers. Finally, it was used to study genetic manipulation of glutathione metabolism in retrovirus production showing that changing cell metabolism steers higher vector expression with titer increases of more than one order of magnitude.This method is a valuable tool not only for cell line development but also for genetic manipulation of viral vector and/or producer cells contributing to advancing the field of viral gene therapy.

206. Follicle-Stimulating Hormone Receptor as a Target in the Redirected T-Cell Therapy for Cancer

Adoptive transfer of T-cells engineered to express chimeric immune receptors is an effective strategy to treat hematological cancers, however, such therapy for solid cancers such as ovarian cancer remains challenging because a safe and effective immunotherapeutic target has not yet been identified. Here, we constructed and evaluated a novel redirected T-cell-based immunotherapy targeting human follicle-stimulating hormone receptor (FSHR), a highly conserved molecule in vertebrate animals with expression limited to gonadal tissues, ovarian cancer and cancer-associated vasculature. Receptor ligand-based anti-FSHR immune receptors were constructed that contained small binding fragments from the ligand for FSHR, follicle stimulating hormone (FSH), fused to T-cell transmembrane and T-cell signaling domains. Human T-cells transduced to express anti-FSHR immune receptors were specifically immunoreactive against FSHR-expressing human and mouse ovarian cancer cell lines in a MHC-non-restricted manner, and produced more than one Th1 type of proinflammatory cytokine. This observation is of special interest, as it provides the opportunity to address potential, but unpredicted, toxicity issues associated with targeting of FSHR in preclinical in vivo studies. Moreover, anti-FSHR-IR T-cells specifically upregulated surface expression of the activation marker CD69 in the presence of FSHR positive targets, but not FSHR-deficient the 293T cell line. Additionally, specific activation of anti-FSHR-IR T-cells by FSHR expressed on tumor cell surface led to efficient tumor cell killing in vitro. Furthermore, to assess the anti-tumor effect of anti-FSHR T-cells, we established human OvCa xenografts in NSG mice by subcutaneous flank injection of CaOV3 cancer cell line followed by two intravenous redirected T-cell administrations. As shown by caliper measurements, FSHR-redirected T-cells elicited anti-tumor potential with suppressed outgrowth of established tumor. Tumor growth was statistically reduced in comparison to control, GFP engineered T-cell treated group or PBS treated animals. These data suggest that systemic delivery of anti-FSHR T-cells to mice bearing FSHR-expressing tumors may result in tumor trafficking, activation, and lysis at location of tumor.In summary, we have successfully exploited for the first time a novel therapeutic antigen, the FSHR protein, expressed on tumor cell surface, to deliver T-cell based immune-therapy of cancer. Given its highly restricted expression in cancer, cancer-associated vessels and gonadal tissues, the rationale for FSHR targeting is strong and supports further exploration of FSHR-targeted immune therapy approaches for cancer patients.

Exosomes are unlikely involved in intercellular Nef transfer.

HIV-1 Nef is an important pathogenic factor for HIV/AIDS pathogenesis. Several recent studies including ours have demonstrated that Nef can be transferred to neighboring cells and alters the function of these cells. However, how the intercellular Nef transfer occurs is in dispute. In the current study, we attempted to address this important issue using several complementary strategies, a panel of exosomal markers, and human CD4+ T lymphocyte cell line Jurkat and a commonly used cell line 293T. First, we showed that Nef was transferred from Nef-expressing or HIV-infected Jurkat to naïve Jurkat and other non-Jurkat cells and that the transfer required the membrane targeting function of Nef and was cell density-dependent. Then, we showed that Nef transfer was cell-cell contact-dependent, as exposure to culture supernatants or exosomes from HIV-infected Jurkat or Nef-expressing Jurkat and 293T led to little Nef detection in the target cells Jurkat. Thirdly, we demonstrated that Nef was only detected to be associated with HIV virions but not with acetylcholinesterase (AChE+) exosomes from HIV-infected Jurkat and not in the exosomes from Nef-expressing Jurkat. In comparison, when it was over-expressed in 293T, Nef was detected in detergent-insoluble AChE+/CD81low/TSG101low exosomes, but not in detergent-soluble AChE-/CD81high/TSG101high exosomes. Lastly, microscopic imaging showed no significant Nef detection in exosomal vesicle-like structures in and out 293T. Taken together, these results show that exosomes are unlikely involved in intercellular Nef transfer. In addition, this study reveals existence of two types of exosomes: AChE+/CD81low/TSG101low exosomes and AChE-/CD81high/TSG101high exosomes.

Chenodeoxycholate (CDCA) Activation of Ca2+‐Dependent Cl‐ Transport in Human Embryonic Kidney‐293 Cells (HEK‐293) is CFTR‐Independent

Bile acids (BAs) are increasingly recognized to have hormone‐like functions. For example, the dihydroxy BA CDCA stimulates Cl‐ transport in the human colonic cell line T84 via the cystic fibrosis transmembrane conductance regulator (CFTR). To explore CDCA signaling, we examined its action in CFTR‐transfected HEK (HEK‐CFTR) by iodide efflux (IE), a method used to measure Cl‐ channel activity. CDCA (500μM)‐induced IE was not inhibited by CFTRinh172 (20μM, n=4) in HEK‐CFTR, suggesting CDCA stimulates a non‐CFTR Cl‐ channel in HEK. Screening for mRNA transcripts in HEK revealed expression of Ca2+‐activated TMEM16A, voltage‐gated ClC2, but not CFTR Cl‐ channels (Physiol Rep. 2(9): 1‐16, '14). Also, CDCA—but not the cAMP activator forskolin—increases IE in HEK (max IE in fold increase of baseline: CDCA: 5.8±1; Forskolin [10µM]: 3.7±0.4). To assess if CDCA action in HEK is Ca2+ dependent (n=3), cells were pretreated with the Ca2+ chelator BAPTA (40μM) or the IP3 receptor inhibitor 2‐APB (200μM). BAPTA and 2‐APB reduced CDCA‐induced IE by 21% and 52% respectively, indicating a role for [Ca2+]i. The muscarinic M3 receptor—coupled to Ca2+ release by Gαq—has been shown to be activated by BAs and stimulate cell proliferation,but has yet to be linked to BA‐induced Cl‐ transport. Of the muscarinic receptor isoforms (M1‐5), HEK express only M3 mRNA, but the receptor antagonist atropine (10μM) had no effect on CDCA action. Thus, CDCA‐induced IE in HEK is CFTR independent and is mediated by [Ca2+]i and IP3 receptors. Our data suggest a role for TMEM16A in CDCA‐induced Cl‐ secretion in HEK and demonstrate that HEK can serve as a model for studying BA‐action unrelated to CFTR.

Five new phorbol esters with cytotoxic and selective anti-inflammatory activities from Croton tiglium.

Five new phorbol esters, (four phorbol diesters, 1-4, and one 4-deoxy-4α-phorbol diester, 5), as well as four known phorbol esters analogues (6-9) were isolated and identified from the branches and leaves of Croton tiglium. Their structures were elucidated mainly by extensive NMR spectroscopic, and mass spectrometric analysis. Among them, compound (1) was the first example of a naturally occurring phorbol ester with the 20-aldehyde group. Compounds 2-5, and 7-9 showed potent cytotoxicity against the K562, A549, DU145, H1975, MCF-7, U937, SGC-7901, HL60, Hela, and MOLT-4 cell lines, with IC50 values ranging from 1.0 to 43 μM, while none of the compounds exhibited cytotoxic effects on normal human cell lines 293T and LX-2, respectively. In addition, compound 3 exhibited moderate COX-1 and COX-2 inhibition, with IC50 values of 0.14 and 8.5 μM, respectively.

Solvatochromic Nile Red probes with FRET quencher reveal lipid order heterogeneity in living and apoptotic cells.

Detecting and imaging lipid microdomains (rafts) in cell membranes remain a challenge despite intensive research in the field. Two types of fluorescent probes are used for this purpose: one specifically labels a given phase (liquid ordered, Lo, or liquid disordered, Ld), while the other, being environment-sensitive (solvatochromic), stains the two phases in different emission colors. Here, we combined the two approaches by designing a phase-sensitive probe of the Ld phase and a quencher of the Ld phase. The former is an analogue of the recently developed Nile Red-based probe NR12S, bearing a bulky hydrophobic chain (bNR10S), while the latter is based on Black Hole Quencher-2 designed as bNR10S (bQ10S). Fluorescence spectroscopy of large unilamellar vesicles and microscopy of giant vesicles showed that the bNR10S probe can partition specifically into the Ld phase, while bQ10S can specifically quench the NR12S probe in the Ld phase so that only its fraction in the Lo phase remains fluorescent. Thus, the toolkit of two probes with quencher can specifically target Ld and Lo phases and identify their lipid order from the emission color. Application of this toolkit in living cells (HeLa, CHO, and 293T cell lines) revealed heterogeneity in the cell plasma membranes, observed as distinct probe environments close to the Lo and Ld phases of model membranes. In HeLa cells undergoing apoptosis, our toolkit showed the formation of separate domains of the Ld-like phase in the form of blebs. The developed tools open new possibilities in lipid raft research.

In vitro adhesion properties of Shiga toxin-producing Escherichia coli isolated from cattle, food, and humans.

Shiga toxin-producing Escherichia coli (STEC) are able to cause serious illnesses ranging from diarrhea to hemorrhagic colitis and hemolytic-uremic syndrome (HUS). These bacteria colonize the digestive tract of humans and produce Shiga-toxins, which are considered to be essential for virulence and are crucial in lethal infection. Colon colonization is supposed to be a determinant step in the development of the infection, but the virulence traits that mediate this step are unclear. We analyzed the ability of 256 STEC strains belonging to seropathotype A (the most virulent O157:H7 serotype) to seropathotype E (not involved in human disease) to adhere to HEp-2, HCT-8, and T84 cell lines. Of the 256 STEC tested most (82%) were non-adherent in our assays. The adhesion levels were globally low and were not related to pathogenicity, although the highest levels were associated to O26:H11 and O103:H2 strains of seropathotype B (associated with HUS but less commonly than serotype O157:H7), possessing both the eae and toxB genes.

Regulation of TWIK-related potassium channel-1 (Trek1) restitutes intestinal epithelial barrier function.

The disruption of epithelial barrier integrity is an important factor in the pathogenesis of various immune disorders. However, the restitution of the compromised barrier functions is difficult. This study investigates the regulation of TWIK-related potassium channel-1 (Trek1) in the restitution of intestinal epithelial barrier functions. The human colon epithelial cell line T84 was cultured in monolayers and used to observe epithelial barrier functions in vitro. An intestinal allergy mouse model was created. Cytokine levels were determined by enzyme-linked immunosorbent assay and western blotting. The results showed that Trek1 deficiency induced T84 monolayer barrier disruption. Allergic responses markedly suppressed the expression of Trek1 in the intestinal epithelia via activating the mitogen-activated protein kinase pathways and increasing the expression of histone deacetylase-1. The inhibition of histone deacetylase-1 by sodium butyrate or the administration of a butyrate-producing probiotic (Clostridium butyricum) restored the intestinal epithelial barrier functions and markedly enhanced the effect of antigen-specific immunotherapy. The data suggest that Trek1 is required for the maintenance of intestinal epithelial barrier integrity. Allergic responses induce an insufficiency of Trek1 expression in the intestinal epithelia. Trek1 expression facilitates the restoration of intestinal epithelial barrier functions in an allergic environment.

Abstract B06: Chemotherapeutic agents attenuate subsequent CXCL12-induced migration of colon cancer cells by selecting for CXCR4-negative cells and increasing peptidase CD26

Abstract Conventional chemotherapy eliminates the bulk of colorectal cancer (CRC) following surgery. However, recurrence may occur due to the persistence of drug-resistant and cancer-initiating cells that survive exposure to the chemotherapeutic agents. The residual effects of chemotherapy on such surviving cancer cells, and the possible implication for subsequent evolution of metastatic disease, are not well understood. We evaluated the expression and function of the chemokine receptor CXCR4, which is known to enable CRC metastasis, as well as the cancer-initiating cell marker and peptidase CD26, which terminates activity of its chemokine CXCL12. The major CRC chemotherapeutics 5-fluorouracil, oxaliplatin and SN-38 (the active metabolite of irinotecan), as well as cisplatin, doxorubicin, methotrexate and vinblastine, each caused decreases in cell-surface CXCR4 and concomitant increases in CD26 on surviving viable cells from HT-29, T84, HRT-18, SW480 and SW620 CRC cell lines. Flow cytometry revealed that the decline in CXCR4 was associated with a significant loss of CXCR4+ cells. Elevations in CD26 were observed across the entire cell population and were paralleled by increases in both the intrinsic dipeptidyl peptidase activity of CD26 as well as its capacity to bind extracellular adenosine deaminase. CD26-annexin V-propidium iodide co-staining confirmed that CD26 was elevated only on live cells. Orthotopic HT-29 xenografts treated with standard CRC chemotherapeutics 5-fluorouracil, irinotecan, or oxaliplatin showed dramatic increases in CD26 compared to untreated tumors. Consistent with the loss of CXCR4 and gain in CD26, migratory responses to exogenous CXCL12 were eliminated in cells pretreated with cytotoxic agents, although cells retained basal motility. Analysis of cancer-initiating cell CD44 and CD133 subsets showed that drug treatment and elevated CD26 was most closely associated with enrichment of the CD44+CD133- cell population, suggesting benefits of standard chemotherapy may be derived from selective elimination of cell populations by the combination of complementary drugs 5-fluorouracil and oxaliplatin. Our results indicate that conventional anticancer agents may act to inhibit chemokine-mediated migration through eradication of CXCR4+ cells and attenuation of chemokine gradients through elevation of CD26 activity. Citation Format: Murray J. Cutler, Erica L. Lowthers, Cynthia L. Richard, Dagmar M. Hajducek, Paul A. Spagnuolo, Jonathan Blay. Chemotherapeutic agents attenuate subsequent CXCL12-induced migration of colon cancer cells by selecting for CXCR4-negative cells and increasing peptidase CD26. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Drug Sensitivity and Resistance: Improving Cancer Therapy; Jun 18-21, 2014; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(4 Suppl): Abstract nr B06.

MiR-101 Suppresses Vascular Endothelial Growth Factor C That Inhibits Migration and Invasion and Enhances Cisplatin Chemosensitivity of Bladder Cancer Cells

BackgroundThe microRNA miR-101 is downregulated in several cancers, including bladder cancer. However, miR-101’s role in the invasion, metastasis, and chemosensitivity of bladder cancer cells remains unclear. This study was conducted to determine miR-101’s role on the lymphangiogenic molecule vascular endothelial growth factor C (VEGF-C) and their effects upon bladder cancer cell migration, invasion, and chemosensitivity to cisplatin.MethodsTwo bladder cancer cell lines (T24 and 5637) and the tool cell line 293T were employed here. Bladder cancer cells were transfected with either a miR-101 overexpression vector or a scrambled-sequence lentivirus, both of which exhibited a high transfection efficiency. Non-transfection was used as a mock negative control. Wound healing and Transwell assays were performed to measure cell migration and invasiveness. A luciferase reporter assay was performed to validate miR-101’s interaction with VEGF-C’s 3′ untranslated region followed by RT-PCR and Western blot confirmation. An MTS assay was used to evaluate the cisplatin sensitivity of the cell lines.ResultsmiR-101 overexpression significantly inhibited the migration and invasiveness while significantly enhancing cisplatin sensitivity. miR-101 negatively regulated VEGF-C protein expression, and VEGF-C overexpression rescued the effects of miR-101 overexpression, indicating that miR-101 negatively regulates VEGF-C protein expression post-transcriptionally. miR-101 and VEGF-C interference independently enhanced cisplatin cytotoxicity in bladder cancer cells.ConclusionsmiR-101 suppresses VEGF-C expression, inhibits cell migration and invasion, and increases cisplatin sensitivity in bladder cancer cells. This study provides new insight into miR-101’s role in bladder cancer and shows miR-101’s promise as a potential molecular target for bladder cancer.

Construction of SIRT1 promoter expression vector and its activity analysis as well as influence of AML1-ETO on transcriptional regulation of SIRT1 gene

This study was aimed to analyze the expression and regulation mechanism of SIRT1 in AML1-ETO positive leukemia to find the core promoter. The real-time RT-PCR was used to detect the expression of SIRT1 in AML1-ETO positive leukemia cell line and clinical samples of leukemia patients, a SIRT1 promoter-luciferase reporter vector was constructed and the promoter activity was evaluated in the 293T cell line. A series of possible core promoter fragments of the SIRT1 5'-untranslated region were amplified by PCR, the PCR products were cloned into XhoI/HindIII-digested pGL3-Basic reporter vector, the poly-cationic compound SuperFect reporter vector complexes were transfected into 293T cells.The dual-luciferase Reporter Assay System was used to quantitate the reporter vector luciferase activity. The six kinds of promoter fragment of SIRT1 gene were successfully constructed and cloned into the pGL3-Basic reporter vector, which was authenticated by XhoI/HindIII co-digestion and DNA sequencing. The luciferase activity of the promoter construct was significantly higher than that of the pGL3-Basic promoter in 293T cells. The luciferase report gene assay was also used to detect the regulation of AML1-ETO on the transcription activity of SIRT1 promoter. The results showed that the expression level of SIRT1 increased with the increase mens of AML1-ETO, the promoter of SIRT1 could be bound by AML1-ETO. The SIRT1 promoter-luciferase reporter vector is successfully constructed, the transfection system used in this study can effectively transfer gene in 293T cells. The SIRT1 core promoter possesses higher activity in 293T cells and can promote significantly expression of luciferase reporter gene in 293T cells. The transcription regulation of AML1-ETO on SIRT1 is carried out via promoting its promoter activity.

Bone Morphogenetic Protein 2 Gene Delivery via Polyethylene Imine Grafted Chondroitin Sulfate Non-viral Gene Carrier

Background: Bone morphogenetic protein 2 (BMP-2) has been frequently used for bone regeneration. The purpose of this study was to design a gene vector to deliver the BMP-2 plasmid into cells. Polyethylene imine (PEI) is commonly used for gene transfer, however the high cytotoxicity often leads to decreased transfection efficiency. Solutions to this problem have been widely discussed, one of which being the grafting of a highly biocompatibility polymer such as chondroitin sulfate (CS). Methods: Different molecular weights (1,800 and 25,000 g/mol) of PEI were grafted onto CS (PEI1.8K-g-CS and PEI25K-g-CS, respectively) through the ethyldimethylaminopropyl carbodiimide/ N-hydroxysuccinimide reaction. This modification resulted in a non-viral gene carrier with improved biocompatibility as well as enhanced transfection efficiency compared to PEI alone. Cytotoxicity toward human embryonic kidney cell line (293T) was assayed. Results: Cell viability in the PEI-grafted-CS group was higher than that of the PEI group, and this was particularly evident at high concentrations. The efficiency of transfection and the amount of intracellular plasmid DNA were monitored using green fluorescent protein. The expression of BMP-2 was measured by enzyme-linked immunosorbent assay. A polymer:DNA weight ratio of 4:1 in the PEI25K-g-CS/DNA polyplexes exhibited the highest transfection efficiency. Conclusions: The low toxicity and high transfection efficiency of PEI25K-g-CS make it ideal for application in gene delivery and therapy.

Assessment of humoral immune response of a Cytomegalovirus DNA-vaccine candidate in BALB/c mice

Introduction: Glycoprotein B (gB) is the major antigen for induction of humoral responses against human cytomegalovirus (HCMV) making it an attractive candidate for immune prophylaxis. In the present study, the humoral immune response of BALB/c mice to a truncated HCMV gB protein fused with GFP was evaluated.:The truncated gB coding sequence was synthesized and cloned in pEGFPN1 eukaryotic expression vector and expr essed in HEK 293T cell line. After optimization, expression of the recombinant truncated HCMV gB was verified using HRP - conjugated polyclonal antibody specific for HCMV gB.The level of humoral immune responses was assessed in mice using DNA/DNA, peptide/peptide, and DNA/ peptide (prime -boost) immunization strategies. Results:Cloning of the truncated gB coding sequence in the pEGFPN1 was verified by restriction enzyme analysis and sequencing. After optimizing the transfection procedure the number of the GFP positive cells reached 32%. Western blot analysis confirmed theinvitroexpression of the truncated HCMV gB protein with an appa rent molecular weight of approximately 70 kDa.In vivoprime-boost immunization using HCMV gB DNA/peptide regimen showed significantly higher humoral immune responses compared to the control groups. Conclusion:This study demonstrated that thepEGFPN1 eukaryotic expression vector could be usedto optimize and evaluate the expression of this truncated protein.The results also showed that the DNA/peptide vaccination could induce a significant antibody response in animal model.