Human Bladder Cancer T24 Cells Research Articles

Bufalin sensitizes human bladder carcinoma cells to TRAIL-mediated apoptosis.

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily, has garnered interest as it is relatively non-toxic to normal cells, but selectively induces apoptotic cell death in multiple types of transformed or malignant cells. Bufalin is the major digoxin-like immunoreactive component of Sum Su, which is obtained from the skin and parotid venom gland of the toad. Bufalin is known to inhibit cell proliferation and induce apoptosis in a variety of cancer cells. The present study investigated whether bufalin promoted TRAIL-induced apoptotic cell death. In the present study, a combined treatment using bufalin and TRAIL significantly increased TRAIL-mediated inhibition of cell viability and increased apoptosis in T24 human bladder cancer cells. The apoptotic effects were associated with the upregulation of death receptor proteins and the downregulation of cellular Fas-associated death domain-like interleukin-1β-converting enzyme inhibitory protein and X-linked inhibitor of apoptosis protein. Furthermore, the data revealed that bufalin and TRAIL activated caspase-3, −8 and −9 and subsequently increased the degradation of poly (ADP-ribose) polymerase. Taken altogether, the nontoxic doses of bufalin and TRAIL sensitized T24 cells to TRAIL-mediated apoptosis. Therefore, bufalin may provide an effective therapeutic strategy for the safe treatment of human bladder cancers that are resistant to TRAIL.

Isoliquiritigenin induces apoptosis of human bladder cancer T24 cells via a cyclin-dependent kinase-independent mechanism.

The aim of the present study was to investigate whether an increase in cyclin-dependent kinase 2 (CDK2) activity is involved in apoptosis of human bladder cancer T24 cells induced by isoliquiritigenin (ISL). The viability of T24 cells was estimated using a sulforhodamine B assay. Cell morphological changes were examined using Hoechst 33258 staining. The apoptotic rate was determined by staining cells with Annexin V-fluorescein isothiocyanate and propidium iodide labeling. The mitochondrial membrane potential (ΔΨm) was measured using 5,5,6,6-tetrachloro-1,1, 3,3-tetraethyl benzimidazole carbocyanine iodide. Alterations in the apoptosis-related regulators B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Bcl-2-interacting mediator of cell death (Bim), apoptotic protease-activating facter-1 (Apaf-1), caspase-9 and caspase-3 were determined using reverse transcription-polymerase chain reaction (PCR) and quantitative PCR methods. Western blot analysis was used to detect the expression of Bcl-2, Bax and caspase-3. CDK2 activity was measured using a spectrometric assay. Following treatment with ISL (between 30 and 70 µg/ml) for 24 h, typical apoptotic morphological changes were observed in T24 cells, exhibiting an edge set of chromosomes, nuclear condensation, nuclear fragmentation and other morphological features. Treatment with ISL increased the apoptotic ratio of T24 cells in a concentration-dependent manner and induced a decrease in the ΔΨm in a time-dependent manner. Treatment with ISL upregulated the expression of Bax, Bim, Apaf-1, caspase-9 and caspase-3, downregulated the expression of Bcl-2, and increased CDK2 activity. MK-8776 (an inhibitor of CDK2) antagonized the apoptosis induced by ISL, and, compared with treatment with ISL alone, pretreatment with MK-8776 inhibited the decrease in ΔΨm, downregulated the mRNA expression of Bax, Bim, Apaf-1, caspase-9 and caspase-3, and upregulated Bcl-2 mRNA expression. Western blot analysis demonstrated that, with increasing ISL concentration, the Bcl-2 expression level was significantly decreased (P<0.05), whereas caspase-3 and Bax expression levels were significantly increased (P<0.01). These results indicated that ISL treatment caused a significant decrease in the proliferation rate and increase in apoptosis of T24 cells. The mechanism by which ISL induces T24 cell apoptosis in vitro may be associated with an increase in CDK2 activity, downregulation of the ΔΨm and activation of caspase-3/caspase-9-mediated mitochondrial apoptotic signaling pathways.

Oxymatrine inhibits proliferation of human bladder cancer T24 cells by inducing apoptosis and cell cycle arrest

Oxymatrine has been shown to exert an antitumor effect on several types of cancer cells. However, the role of oxymatrine in bladder cancer has not yet been evaluated. The present study was designed to investigate the potential anti-proliferative effect of oxymatrine on bladder cancer T24 cells and the possible mechanisms involved. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell growth, and the cell morphology was examined using hematoxylin and eosin staining, wrights' staining and electron microscopy. The caspase-3 and survivin mRNA and protein levels were assessed using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The expression of tumor protein p53 (p53), Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl-2) were analyzed using immunohistochemistry. Oxymatrine inhibited the proliferation of the T24 cells in a dose- and time-dependent manner. Oxymatrine also induced apoptosis and cell cycle arrest in the cells, in association with the upregulation of caspase-3 and Bax, and the downregulation of survivin, Bcl-2 and p53 expression. Overall, oxymatrine inhibits the proliferation of human bladder cancer cells by inducing apoptosis and cell cycle arrest via mechanisms that involve p53-Bax signaling and the downregulation of survivin expression.

Induction of mitochondrial-dependent apoptosis in T24 cells by a selenium (Se)-containing polysaccharide from Ginkgo biloba L. leaves

In the present study, a selenium (Se)-containing polysaccharide (Se-GBLP) was isolated and purified from the leaves of Ginkgo biloba L. Se-GBLP was further evaluated for its antitumor activity against human bladder cancer T24 cells together with the possible mechanism of action. Our results showed that treatment of T24 cells with Se-GBLP (50, 100 and 200μg/ml) for 48h significantly inhibited cell viability and induced apoptosis in a dose- dependent manner. This Se-GBLP-induced apoptosis is associated with an increased protein expression of pro-apoptotic Bax, decreased expression of anti-apoptotic Bcl-2, loss of mitochondrial membrane potential, and cleavage of caspase-9, caspase-3 and PARP, suggesting that Se-GBLP-induced apoptosis occurs through the mitochondria-dependent pathway. Se-GBLP therefore merits further investigation as a promising preventive and/or therapeutic agent against human bladder cancer.

Inhibition of T24 and RT4 Human Bladder Cancer Cell Lines by Heterocyclic Molecules.

BackgroundBladder cancer is a major widespread tumor of the genitourinary tract. Around 30% of patients with superficial cancers develop invasive and metastatic pathology.Material/MethodsSome new heterocyclic 4-methyl coumarin derivatives were designed using molecular modeling studies to evaluate their potential against bladder cancer lines T24 and RT-4. The designed compounds that showed good binding affinity to T24 and RT4 were synthesized, with excellent yield. The synthesized compounds after structural evaluation were further evaluated for their antiproliferative activity by cell viability assay, cell cycle analysis, and apoptosis assay.ResultsThe compound BC-14 exhibited the best cytotoxicity against T24 cells, but were not highly active against RT4 cells.ConclusionsThe results of the present study may suggest the selectivity pattern of the synthesized compounds. These results should be explored further with chemical modification for other cancer types.

Concurrent Autophagy Inhibition Overcomes the Resistance of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Human Bladder Cancer Cells.

Despite the potential therapeutic efficacy of epithelial growth factor receptor (EGFR) inhibitors in the treatment of advanced stage bladder cancer, there currently is no clear evidence to support this hypothesis. In this study, we investigate whether the concurrent treatment of autophagy-blocking agents with EGFR inhibitors exerts synergistic anti-cancer effects in T24 and J82 human bladder cancer cells. Lapatinib and gefitinib were used as EGFR inhibitors, and bafilomycin A1 (BFA1), chloroquine (CQ) and 3-methyladenine (3-MA) were used as the pharmacologic inhibitors of autophagy activities. To assess the proliferative and self-renewal capabilities, the Cell Counting Kit-8 (CCK-8) assay and a clonogenic assay were performed, respectively. To examine apoptotic cell death, flow cytometry using annexin-V/propidium iodide (PI) was used. To measure the autophagy activities, the expression levels of LC3I and II was determined by Western blot analysis. To validate the synergistic effects of autophagy inhibition with EGFR inhibitors, we specifically blocked key autophagy regulatory gene ATG12 by transfection of small interference RNA and examined the phenotypic changes. Of note, lapatinib and gefitinib triggered autophagy activities in T24 and J82 human bladder cancer cells, as indicated by upregulation of LC3II. More importantly, inhibiting autophagy activities with pharmacologic inhibitors (BFA1, CQ or 3-MA) remarkably reduced the cell viabilities and clonal proliferation of T24 and J82 cells, compared to those treated with either of the agents alone. We also obtained similar results of the enhanced anti-cancer effects of EGFR inhibitors by suppressing the expression of ATG12. Notably, the apoptotic assay showed that synergistic anti-cancer effects were induced via the increase of apoptotic cell death. In summary, concomitant inhibition of autophagy activities potentiated the anti-cancer effects of EGFR inhibitors in human bladder cancer cells, indicating a novel therapeutic strategy to treat advanced bladder cancer.

Induction of apoptosis by ethanol extract of Citrus unshiu Markovich peel in human bladder cancer T24 cells through ROS-mediated inactivation of the PI3K/Akt pathway.

Citrus unshiu peel has been used to prevent and treat various diseases in traditional East-Asian medicine including in Korea. Extracts of C. unshiu peel are known to have various pharmacological effects including antioxidant, anti-inflammatory, and antibacterial properties. Although the possibility of their anti-cancer activity has recently been reported, the exact mechanisms in human cancer cells have not been sufficiently studied. In this study, the inhibitory effect of ethanol extract of C. unshiu peel (EECU) on the growth of human bladder cancer T24 cells was evaluated and the underlying mechanism was investigated. The present study demonstrated that the suppression of T24 cell viability by EECU is associated with apoptosis induction. EECU-induced apoptosis was found to correlate with an activation of caspase-8, -9, and -3 in concomitance with a decrease in the expression of the inhibitor of apoptosis family of proteins and an increase in the Bax:Bcl-2 ratio accompanied by the proteolytic degradation of poly(ADP-ribose) polymerase. EECU also increased the generation of reactive oxygen species (ROS), collapse of mitochondrial membrane potential, and cytochrome c release to the cytosol, along with a truncation of Bid. In addition, EECU inactivated phosphatidylinositol 3-kinase (PI3K) as well as Akt, a downstream molecular target of PI3K, and LY294002, a specific PI3K inhibitor significantly enhanced EECU-induced apoptosis and cell viability reduction. However, N-acetyl cysteine, a general ROS scavenger, completely reversed the EECU-induced dephosphorylation of PI3K and Akt, as well as cell apoptosis. Taken together, these findings suggest that EECU inhibits T24 cell proliferation by activating intrinsic and extrinsic apoptosis pathways through a ROS-mediated inactivation of the PI3K/Akt pathway.

Lycorine induces apoptosis of bladder cancer T24 cells by inhibiting phospho-Akt and activating the intrinsic apoptotic cascade

Lycorine, an alkaloid extracted from Amaryllidaceae genera, exhibits antitumor activities against several human solid-tumor and leukemia cells with extensive influence on various cell signaling molecules. However, the effect of lycorine on bladder cancer has not yet been investigated. In this study, we demonstrated that lycorine induced apoptosis in human bladder cancer T24 cells, an effect that is mediated via inhibition of phospho-Akt expression and the consequent activation of caspase-3 and Bax in vitro. In an in vivo experiment, T24 cells were subcutaneously implanted in the right rear flank of nu/nu mice. Lycorine treatment for 14 days significantly inhibited tumor growth compared with that in controls. Collectively, our findings suggest that lycorine suppressed the Akt pathway and activated the intrinsic apoptotic cascade, leading to the apoptosis of bladder cancer cells. We suggest that lycorine can be a viable therapeutic option for bladder cancer patients.

Cigarette smoke extract induces epithelial-mesenchymal transition of human bladder cancer T24 cells through activation of ERK1/2 pathway.

Bladder cancer is a common genitourinary malignant disease worldwide. Abundant evidence has shown that cigarette smoke (CS) is a crucial risk factor for bladder cancer. Nevertheless, the mechanism underlying the relationship between cigarette smoking and bladder cancer remains unclear. In the present study, we investigated the effects of cigarette smoke extract (CSE) on mitogen-activated protein kinase (MAPK) pathway activation and EMT alterations in human bladder cancer T24 cells, and the preventive effect of extracellular regulated protein kinases 1 and 2 (ERK1/2) inhibitor U0126 was further examined. Our results illustrated that CSE exposure induced morphological change of human bladder cancer T24 cells, enhanced migratory and invasive capacities, reduced epithelial marker expression and elevated mesenchymal marker expression. Meanwhile, exposure of T24 cells to CSE resulted in activation of ERK1/2 pathway as well as activator protein 1 (AP-1) proteins. Interestingly, treatment with ERK1/2 inhibitor U0126 effectively abrogated CSE-triggered EMT and ERK1/2/AP-1 activation. These findings provide novel insight into the molecular mechanisms of CS-associated bladder cancer and may open up new avenues in the search for potential target of bladder cancer intervention.

A Novel Role of Dickkopf-Related Protein 3 in Macropinocytosis in Human Bladder Cancer T24 Cells.

Dickkopf-related protein 3 (Dkk-3) is a potential tumor suppressor reported in various cancer entities. However, we found that Dkk-3 was exceptionally upregulated in bladder cancer T24 cells. To validate the biological role of Dkk-3 other than a tumor suppressor, we examined the function of Dkk-3 in T24 cells. Gene silencing of Dkk-3 inhibited cell growth through inducing G0/G1 cell-cycle arrest. Furthermore, Dkk-3 knock-down caused macropinocytosis accompanied by autophagy, which were canceled in part by their inhibitors 5-(N-ethyl-N-isopropyl) amiloride (EIPA) and 3-methyladenine (3-MA). The macropinocytosis was induced by the Dkk-3 knock-down when there were sufficient extracellular nutrients. On the other hand, when the nutritional condition was poor, the autophagy was mainly induced by the Dkk-3 knock-down. These data indicated that Dkk-3 has a role in modulating macropinocytotic and autophagic pathways, a distinct function other than a Wnt antagonist.

A simple method to induce hypoxia-induced vascular endothelial growth factor-A (VEGF-A) expression in T24 human bladder cancer cells.

Angiogenesis is an essential process for the establishment, development, and dissemination of several malignant tumors including bladder cancer. The hypoxic condition promotes the stabilization of hypoxia-inducible factor 1 alpha (HIF-1α), which translocates to the nucleus to mediate angiogenic factors including the vascular endothelial growth factor A (VEGF-A). AnaeroGen system was developed for microbiology area to create a low oxygen tension required to the growth of anaerobic bacteria. Here, we hypothesized the use of AnaeroGen system to induce hypoxia in T24 human bladder carcinoma cells, in order to promote the overexpression of VEGF-A. T24 cells were cultured in six-well plates containing McCoy medium. Exposures of T24 cells to hypoxia for 1, 8, 24, and 48h were performed using the Oxoid AnaeroGen system, while T24 cells under normoxia were used as control. The expression of VEGF-A and HIF-1α was analyzed by real-time PCR. ELISA for HIF-1α was carried out. The VEGF-A expression increased significantly by Oxoid AnaeroGen-induced hypoxia in a time-depending manner, reaching the peak in 48h of hypoxia. Although HIF-1α mRNA was not changed, HIF-1α protein was increased in the presence of hypoxia, reaching a peak at 8h. These results demonstrated that the Oxoid AnaeroGen system is a simple method to expose T24 cells to hypoxia and efficiently to upregulate VEGF expression in T24 cells.

Antitumor activity evaluation of meso-tetra (pyrrolidine substituted) pentylporphin-mediated photodynamic therapy in vitro and in vivo

Photodynamic therapy is a minimally invasive and promising new method in cancer treatment and has attracted considerable attention in recent years. An ideal photosensitizer is a crucial element to photodynamic therapy. In the present paper, a novel porphyrin derivative, 5, 10, 15, 20-tetrakis (5-(pyrrolidin-1-yl) pentyl) porphin (TPPP) was synthesized. Its spectroscopic and physicochemical properties, therapeutic efficacy as a photosensitizer in photodynamic therapy for human bladder cancer in vitro and in vivo were investigated. TPPP had strong absorption at 648nm (ε=1.75×104M−1cm−1), and two fluorescence emission peaks at 652nm and 718nm. PDT with TPPP showed low dark toxicity and high phototoxicity to human bladder cancer T24 cells in vitro. In bearing T24 tumor nude mice, the growth of tumor was significantly inhibited by combining use of 5mg/kg TPPP with 100J/cm2 (650nm, 180mW/cm2) laser irradiation at 3h following injection of TPPP. The antitumor effect was also confirmed with histopathological assay. The histopathological study results revealed that PDT using TPPP and 100J/cm2 (650nm, 180mW/cm2) laser irradiation induced tumor cells shrunken and necrotic. These results indicate that TPPP is useful as a new photosensitizer in PDT for cancer, and deserves further investigation.

Effects of Licochalcone A on Cell-cycle Distribution and Glycolysis in Human Bladder Cancer T24 Cells

This study investigates the effects of LCA on cell-cycle distribution and glycolysis in human bladder cancer T24 cells. The mRNA expression of HIF-1α, vascular endothelial growth factor (VEGF), glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA) and Fructose-2, 6-Biphosphatase 3 (PFKFB3) were assessed using RT-PCR. LCA elicited an anti-proliferative effect on human bladder cancer cells line T24 cells in a concentration-dependent manner; LCA induced a G2/M-phase arrest, as well as a down-regulation of the mRNA level of CDK1 and Cyclin B1; after treated with LCA, the activity of CDK1 was down regulated and the p21 was upregulated. LCA inhibited the ATP production, decreased the glucose uptake and the release of lactic acid. The activities of LDH, HK, and PK were significantly down-regulation. LCA could reduce the level of HIF-1α in T24 cells and significantly reduce the expression of its target genes: VEGF, GLUT1, LDHA and PFKFB3. This study demonstrated that LCA treatment caused a significant decrease in the proliferation and a cell cycle arrest of G2/M phase in T24 cells; the mechanism by which LCA inhibits T24 proliferation may be associated with the inhibition of glycolysis as well as cause G2/M phase arrested.

Acute effect of lactic acid on tumor-endothelial cell metabolic coupling in the tumor microenvironment.

The present study aimed to systematically analyze alterations in the expression of mitochondrial-associated proteins in human bladder cancer T24 cells co-cultured with tumor-associated human umbilical vein endothelial cells (HUVECs), and to investigate the characteristics of bladder cancer cell energy metabolism. The present study used the following techniques: A co-culture system of T24 cells and HUVECs was constructed using a microfluidic chip as a 3D co-culture system; the concentration of lactic acid in the medium of the cells was determined using an automatic microplate reader; a qualitative analysis of mitochondria-associated protein expression was performed by immunofluorescent staining; and a quantitative analysis of mitochondrial-associated protein expression was conducted using western blotting. The present results revealed that between the control groups (monoculture of T24 cells or HUVECs), the mitochondrial-associated protein fluorescence intensity was increased in the HUVECs compared with the T24 cells. The fluorescence intensity of mitochondrial-associated proteins in the HUVEC control group was increased compared with the HUVECs in the experimental co-culture group. In the T24 cells, the protein fluorescence intensity was increased in the experimental co-culture group compared with the control group. In addition, the expression of mitochondria-associated proteins was increased in HUVECs compared with T24 cells in the control groups, while T24 cells in the experimental co-culture group had an increased expression compared with HUVECs in the experimental group (P<0.05). For T24 cells, the expression of mitochondrial-associated proteins was increased in the experimental group compared with the control group, and contrasting results were observed for the HUVECs (P<0.05). Determination of lactic acid concentration demonstrated that lactic acid concentration was highest in the experimental co-culture group, followed by the T24 control group and the HUVEC control group. In conclusion, the present study demonstrated that energy metabolism of the bladder tumor cells does not parallel the 'Warburg effect', since even under sufficient oxygen conditions the tumor cells still undergo glycolysis. Additionally, bladder tumor cells have an efficient oxidative phosphorylation process, wherein tumor cells promote glycolysis in adjacent interstitial cells, thereby causing increased formation of nutritional precursors. These high-energy metabolites are transferred to adjacent tumor cells in a specified direction and enter the Krebs Cycle. Ultimately, oxidative phosphorylation increases, and sufficient ATP is produced.

Cytotoxic effects of kazinol A derived from Broussonetia papyrifera on human bladder cancer cells, T24 and T24R2

BackgroundBroussonetia papyrifera (B. papyrifera), also known as paper mulberry, has been used as a traditional medicine for the treatment of several diseases, including ophthalmic disorders and impotency. However, the biological activity of kazinol A (1) among flavonols isolated from B. papyrifera has not been identified. PurposeWe identified a candidate metabolite for anti-human bladder cancer treatment from B. papyrifera and investigated the possible molecular mechanisms underlying its cytotoxic effects in T24 and cisplatin-resistant T24R2 human bladder cancer cells. MethodsT24 and T24R2 cells were treated with five flavonols from B. papyrifera and their cytotoxic effects were determined using MTT assay, cell cycle analysis, mitochondrial membrane potential, and propidium iodide staining. Autophagy rate was calculated by counting LC3-GFP dots in the cells. All related protein expressions were analyzed by immunoblotting. ResultsCompound 1 showed relatively higher cytotoxicity in the human bladder cancer cells, T24 and T24R2, rather than other tissues-originated cancer cells. Compound 1 significantly attenuated cell growth through G0/1 arrest mediated by a decrease in cyclin D1 and an increase of p21. Apoptosis and autophagy induced by compound 1 treatment was accompanied by a modulation of the AKT-BAD pathway and AMPK-mTOR pathway, respectively. ConclusionsOur results suggest that compound 1 induces cytotoxic effects in human bladder cancer cells, including the cisplatin-resistant T24R2. Compound 1 may be a candidate for the development of effective anti-cancer drug on human urinary bladder cancer.

Cheliensisin A (Chel A) induces apoptosis in human bladder cancer cells by promoting PHLPP2 protein degradation.

Cheliensisin A (Chel A), a styryl-lactone compound extracted from Goniothalamus cheliensis, is reported to have significant anti-cancer effects in various cancer cells. Here we demonstrated that Chel A treatment resulted in apoptosis and an inhibition of anchorage-independent growth in human bladder cancer T24, T24T and U5637 cells. Mechanistic studies showed that such effect is mediated by PH domain and Leucine rich repeat Protein Phosphatases (PHLPP2) protein. Chel A treatment led to PHLPP2 degradation and subsequently increased in c-Jun phosphorylation. Moreover PHLPP2 degradation could be attenuated by inhibition of autophagy, which was mediated by Beclin 1. Collectively, we discover that Chel A treatment induces Beclin-dependent autophagy, consequently mediates PHLPP2 degradation and JNK/C-Jun phosphorylation and activation, further in turn contributing to apoptosis in human bladder cancer cells. Current studies provide a significant insight into understanding of anticancer effect of Chel A in treatment of human bladder cancer.

Emodin enhances cisplatin-induced cytotoxicity in human bladder cancer cells through ROS elevation and MRP1 downregulation.

BackgroundChemoresistance is one of the most leading causes for tumor progression and recurrence of bladder cancer. Reactive oxygen species (ROS) plays a key role in the chemosensitivity of cancer cells. In the present study, emodin (1,3,8-trihydroxy-6-methylanthraquinone) was applied as a ROS generator in combination with cisplatin in T24 and J82 human bladder cancer cells.MethodsCell viability and apoptosis rate of different treatment groups were detected by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and flow cytometry (FCM). The expression of transporters was measured at both the transcription and translation levels using PCR and western blotting. In vitro findings were confirmed by in vivo experiments using tumor-bearing mice. The expression of multidrug resistance-associated protein 1 (MRP1) in tumour tissue was measured using immunohistochemistry and side effects of the emodin/cisplatin co-treatment were investigated by histological examination.ResultsEmodin increased the cellular ROS level and effectively enhanced the cisplatin-induced cytotoxicity of T24 and J82 human bladder cancer cells through decreasing glutathione-cisplatin (GSH-cisplatin) conjugates. It blocked the chemoresistance of T24 and J82 cells to cisplatin through suppressing the expression of MRP1. This effect was specific in T24 and J82 cells but not in HCV-29 normal bladder epithelial cells. Consistent with in vitro experiments, emodin/cisplatin co-treatment increased the cell apoptosis and repressed the MRP1 expression in xenograft tumors, and without obvious systemic toxicity.ConclusionsThis study revealed that emodin could increase the cisplatin-induced cytotoxicity against T24 and J82 cells via elevating the cellular ROS level and downregulating MRP1 expression. We suggest that emodin could serve as an effective adjuvant agent for the cisplatin-based chemotherapy of bladder cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2640-3) contains supplementary material, which is available to authorized users.

Abstract 3001: Accurins are endocytosed by KRAS-mutant cells via macropinocytosis

Abstract Background: BIND-014 is a novel prostate-specific membrane antigen (PSMA)-targeted Accurin (polymeric nanoparticle) encapsulating docetaxel. In a Phase 2 non-small cell lung cancer (NSCLC) trial, BIND-014 demonstrated promising anti-tumor activity in patients with tumors expressing KRAS mutations (mutated Kirsten ras oncogene homolog). KRAS mutations in NSCLC are generally associated with poor response to currently available drug therapy regimens, including docetaxel. Mutant KRAS stimulates an endocytic process known as macropinocytosis, in which extracellular fluid and its constituents are internalized non-selectively into cells. We hypothesized that Accurins preferentially accumulate in KRAS-mutant cells via macropinocytosis, potentially contributing to anti-tumor activity of BIND-014 in KRAS-mutant cancer. Methods: To determine whether BIND-014 is internalized in cells with high levels of macropinocytosis, we treated KRAS-mutant, macropinocytosis-high human NSCLC A549 cells and human bladder cancer T24 cells with PSMA targeted Accurins in which docetaxel was replaced by a fluorescent label, and visualized co-localization with fluorescently labeled markers of macropinocytosis, dextran and BSA, by confocal microscopy. In addition, we quantified the levels of labeled Accurin uptake in A549 cells by fluorescence-activated cell sorting (FACS) and compared them to labeled Accurin internalization in macropinocytosis-low, KRAS-wild-type BxPC3 cells. We further tested the macropinocytosis-dependence of labeled Accurin uptake by treating A549 and BxPC3 cells with the macropinocytosis inhibitor EIPA and measuring changes in Accurin internalization by FACS. Results: Confocal microscopy analysis of A549 and T24 cells co-treated with labeled Accurin and dextran or BSA showed substantial accumulation of Accurin in dextran- and BSA-positive macropinosomes. Moreover, FACS analysis of A549 cells treated with 0.1 ug and 1.0 ug of labeled Accurin revealed 60.4% and 81.8% uptake, respectively, that could be reduced to 3.6% and 3.7% with 50 uM EIPA. By contrast, BxPC3 cells showed 1.8% and 1.5% uptake of 0.1 ug and 1.0 ug labeled Accurin that was reduced to 1.3% and 0.9%, respectively, with 50 uM EIPA by FACS analysis. Conclusions: These data demonstrate that Accurins preferentially enter human cancer cells that display high levels of macropinocytosis and co-localize with several markers of macropinosomes. Moreover, Accurin internalization can be inhibited in macropinocytosis-positive cells with an established chemical inhibitor of macropinocytosis. BIND-014 may therefore preferentially accumulate in KRAS-mutant NSCLC tumors, thereby contributing to the clinical activity seen to date in this tumor type. Citation Format: Jane E. Cullis, Laura Taylor, Susan Low, Dafna Bar-Sagi. Accurins are endocytosed by KRAS-mutant cells via macropinocytosis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3001.

Mapping the interactions and bioactivity of quercetin⿿(2-hydroxypropyl)-β-cyclodextrin complex

Natural products have served as a rich source for drug discovery and development. In the last decade their fruitful integration in the drug discovery pipeline declined due to their reduced bioavailability, mainly attributed to their poor aqueous solubility. We synthesized a quercetin (QUE)⿿(2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) complex that enabled amplification of its solubility and in the same time retained its bioactivity in T24 human bladder cancer cell line. The stability of the complex and the molecular basis of the interactions developed in this host-guest complex were assayed by incorporating an array of analytical techniques and Molecular Dynamics (MD) experiments. 2D DOSY NMR experiment revealed that the diffusion coefficient of free HP-β-CD was 3.55ÿ10⿿10m2s⿿1 while that of QUE⿿HP-β-CD inclusion complex 3.09ÿ10⿿10m2s⿿1, indicating the formation of a complex. Solid and liquid high resolution NMR spectroscopy data showed that the most pronounced differences in chemical shifts at carbons and protons correspondingly during complexation occur in the aromatic ring ο (bearing the two phenolic hydroxyl groups meta to each other). The chemical shift differences in the aromatic ring ο (bearing the two phenolic hydroxyl groups ortho to each other) were less pronounced. The MD results confirmed the experimental data.

301 - Regulation of AMPK-dependent MDR1 expression by resveratrol in cisplatin-resistant human bladder cancer T24 cells via attenuating NF-κB and CRE transcriptional activity

301 - Regulation of AMPK-dependent MDR1 expression by resveratrol in cisplatin-resistant human bladder cancer T24 cells via attenuating NF-κB and CRE transcriptional activity