sepantronium and Lung-Neoplasms

This phase I study was conducted to evaluate the safety and pharmacokinetics of YM155, a potent, selective survivin inhibitor, in combination with erlotinib in patients with EGFR TKI refractory advanced non-small cell lung cancer (NSCLC).. UMIN000031912 at UMIN Clinical Trials Registry (UMIN-CTR).

Topics: Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Non-Small-Cell Lung; Drug Resistance, Neoplasm; ErbB Receptors; Erlotinib Hydrochloride; Female; Follow-Up Studies; Humans; Imidazoles; Lung Neoplasms; Male; Middle Aged; Naphthoquinones; Prognosis; Protein Kinase Inhibitors; Survivin

This phase I/II study examined the safety and efficacy of Sepantronium Bromide (S), a small-molecule selective survivin suppressant, administered in combination with carboplatin (C) and paclitaxel (P).. Forty-one patients were treated on study. Twenty-two patients received escalating doses of S (3.6-12 mg/m(2)) and 19 with untreated stage IV non-small-cell lung cancer (NSCLC) were treated with the maximum tolerated dose of 10 mg/m(2) in combination with standard doses of C (AUC6) and P (200 mg/m(2)) for six cycles. S was administered as a continuous intravenous infusion (CIVI) over 72 h in 21-day treatment cycles. Study end points included safety and toxic effect, response rate, progression-free and overall survival (PFS and OS), as well as exploratory pharmacodynamic correlates.. Treatment with S was well tolerated, and toxic effects were mostly hematological in the phase II study. Two (11%) partial responses were observed with a median PFS of 5.7 months and median OS 16.1 months. Pharmacodynamic analysis did not demonstrate an association with response.. The combination of S (10 mg/m(2)/day 72-h CIVI) administered with C and P every 3 weeks exhibited a favorable safety profile but failed to demonstrate an improvement in response rate in advanced NSCLC.. NCT01100931.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carboplatin; Carcinoma, Non-Small-Cell Lung; Disease-Free Survival; Female; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Male; Middle Aged; Naphthoquinones; Paclitaxel; Survival; Survivin; Treatment Outcome

Purpose Population pharmacokinetics (PK) of sepantronium bromide (YM155) was characterized in patients with non-small cell lung cancer, hormone refractory prostate cancer, or unresectable stage III or IV melanoma and enrolled in one of three phase 2 studies conducted in Europe or the U.S. Method Sepantronium was administered as a continuous intravenous infusion (CIVI) at 4.8 mg/m(2)/day over 7 days every 21 days. Population PK analysis was performed using a linear one-compartment model involving total body clearance (CL) and volume of distribution with an inter-individual random effect on CL and a proportional residual errors to describe 578 plasma sepantronium concentrations obtained from a total of 96 patients by NONMEM Version VI. The first-order conditional estimation method with interaction was applied. Results The one-compartment model with one random effect on CL and two different proportional error models provided an adequate description of the data. Creatinine clearance (CLCR), cancer type, and alanine aminotransferase (ALT) were recognized as significant covariates of CL. CLCR was the most influential covariate on sepantronium exposure and predicted to contribute to a 25 % decrease in CL for patients with moderately impaired renal function (CLCR = 40 mL/min) compared to patients with normal CLCR. Cancer type and ALT had a smaller but nonetheless significant contribution. Other patient characteristics such as age, gender, and race were not considered as significant covariates of CL. Conclusions The results provide the important information for optimizing the therapeutic efficacy and minimizing the toxicity for sepantronium in cancer therapy.

Topics: Adult; Aged; Aged, 80 and over; Carcinoma, Non-Small-Cell Lung; Dose-Response Relationship, Drug; Ethnicity; Female; Follow-Up Studies; Humans; Imidazoles; Infusions, Intravenous; Inhibitor of Apoptosis Proteins; Japan; Lung Neoplasms; Male; Maximum Tolerated Dose; Melanoma; Middle Aged; Models, Biological; Naphthoquinones; Neoplasm Staging; Neoplasms, Hormone-Dependent; Prognosis; Prostatic Neoplasms; Survivin; Tissue Distribution

To evaluate the antitumor activity and safety of YM155, a novel, small-molecule suppressor of survivin, as single-agent therapy in patients with previously treated, advanced non-small-cell lung cancer (NSCLC).. Patients with stage IIIb/IV NSCLC who had experienced treatment failure during one or two prior chemotherapy regimens (at least one of which was platinum based) received YM155 as a continuous intravenous infusion (4.8 mg/m(2)/d) over 168 hours followed by observation for 14 days in 21-day treatment cycles. The primary end point was objective tumor response rate (ORR). Secondary end points included duration of stable disease (SD), progression-free survival (PFS), overall survival (OS), safety and pharmacokinetic profiles, and pharmacodynamic evaluations.. Thirty-seven patients received YM155. Two patients achieved a confirmed partial response, with an ORR of 5.4% (95% CI, 0.7% to 18.2%). An additional 14 patients (37.8%) achieved SD resulting in a disease control rate of 43.2% (95% CI, 27.1% to 60.5%). Median duration of PFS was 1.7 months (95% CI, 1.3 to 2.8 months). Median duration of OS was 6.6 months (95% CI, 4 to 12.2 months), with a 1-year survival rate of 35.1%. Treatment with YM155 was well tolerated with the majority of treatment discontinuations not treatment related.. YM155 exhibited modest single-agent activity in patients with refractory, advanced NSCLC. A favorable safety/tolerability profile was reported. Further evaluation of YM155 in combination with chemotherapy and other targeted agents may be warranted.

Topics: Adult; Aged; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Female; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Male; Microtubule-Associated Proteins; Middle Aged; Naphthoquinones; Survivin; Treatment Failure; Treatment Outcome

The imidazolium compound Ym155 was first reported to be a survivin inhibitor. Ym155 potently induces cell death of many types of cancer cells in preclinical studies. However, in phase II clinical trials Ym155 failed to demonstrate a significant benefit. Studies have suggested that the cytotoxic effects of Ym155 in cancer cells are not mediated by the inhibition of survivin. Understanding the mechanism by which Ym155 induces cell death would provide important insight how to improve its efficacy as a cancer therapeutic. We demonstrate a novel mechanism by which Ym155 induces cell death by localizing to the mitochondria causing mitochondrial dysfunction. Our studies suggest that Ym155 binds mitochondrial DNA leading to a decrease in oxidative phosphorylation, decrease in TCA cycle intermediates, and an increase in mitochondrial permeability. Furthermore, we show that mitochondrial stress induced by Ym155 and other mitochondrial inhibitors activates AMP-activated kinase leading to the downregulation to bone morphogenetic protein (BMP) signaling. We provide first evidence that Ym155 initiates cell death by disrupting mitochondrial function.

Topics: AMP-Activated Protein Kinases; Antineoplastic Agents; Apoptosis; Bone Morphogenetic Proteins; Cell Line, Tumor; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Mitochondria; Naphthoquinones; Survivin

Recent studies have shown that bone morphogenetic protein receptor 2 (BMPR2) regulates cell survival signaling events in cancer cells independent of the BMP type 1 receptor (BMPR1) or the Smad-1/5 transcription factor. Mutations in BMPR2 trafficking proteins leads to overactive BMP signaling, which leads to neurological diseases caused by BMPR2 stabilization of the microtubules. It is not known whether BMPR2 regulates the microtubules in cancer cells and what effect this has on cell survival. It is also not known whether alterations in BMPR2 trafficking effects activity and response to BMPR2 inhibitors.. We utilized BMPR2 siRNA and the BMP receptor inhibitors JL5 and Ym155, which decrease BMPR2 signaling and cause its mislocalization to the cytoplasm. Using the JL5 resistant MDA-MD-468 cell line and sensitive lung cancer cell lines, we examined the effects of BMPR2 inhibition on BMPR2 mislocalization to the cytoplasm, microtubule destabilization, lysosome activation and cell survival.. We show that the inhibition of BMPR2 destabilizes the microtubules. Destabilization of the microtubules leads to the activation of the lysosomes. Activated lysosomes further decreases BMPR2 signaling by causing it to mislocalizated to the cytoplasm and/or lysosome for degradation. Inhibition of the lysosomes with chloroquine attenuates BMPR2 trafficking to the lysosome and cell death induced by BMPR2 inhibitors. Furthermore, in MDA-MD-468 cells that are resistant to JL5 induced cell death, BMPR2 was predominately located in the cytoplasm. BMPR2 failed to localize to the cytoplasm and/or lysosome following treatment with JL5 and did not destabilize the microtubules or activate the lysosomes.. These studies reveal that the inhibition of BMPR2 destabilizes the microtubules promoting cell death of cancer cells that involves the activation of the lysosomes. Resistance to small molecules targeting BMPR2 may occur if the BMPR2 is localized predominantly to the cytoplasm and/or fails to localize to the lysosome for degradation. Video Abstract.

Topics: Bone Morphogenetic Protein Receptors, Type I; Bone Morphogenetic Protein Receptors, Type II; Cell Death; Cell Proliferation; Cell Survival; Humans; Imidazoles; Lung Neoplasms; Lysosomes; Microtubules; Naphthoquinones; Pyrazoles; Pyrimidines; Quinolones; RNA, Small Interfering; Signal Transduction

HER3 mediates drug resistance against epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs), resulting in tumor relapse in lung cancers. Previously, we demonstrated that EGFR induces HER3 overexpression, which facilitates the formation of cancer stem-like tumorspheres. However, the cellular mechanism through which EGFR regulates HER3 expression remains unclear. We hypothesized that EGFR downstream of STAT3 participates in HER3 expression because STAT3 contributes to cancer stemness and survival of EGFR-TKI resistant cancers.. First, RNAseq was used to uncover potential genes involved in the formation of lung cancer HCC827-derived stem-like tumorspheres. EGFR-positive lung cancer cell lines, including HCC827, A549, and H1975, were individually treated with a panel containing 172 therapeutic agents targeting stem cell-associated genes to search for potential agents that could be applied against EGFR-positive lung cancers. In addition, gene knockdown and RNAseq were used to investigate molecular mechanisms through which STAT3 regulates tumor progression and the survival in lung cancer.. BBI608, a STAT3 inhibitor, was a potential therapeutic agent that reduced the cell viability of EGFR-positive lung cancer cell lines. Notably, the inhibitory effects of BBI608 were similar with those associated with YM155, an ILF3 inhibitor. Both compounds reduced G9a-mediated HER3 expression. We also demonstrated that STAT3 upregulated G9a to silence miR-145-5p, which exacerbated HER3 expression in this study.. The present study revealed that BBI608 could eradicate EGFR-positive lung cancers and demonstrated that STAT3 enhanced the expression of HER3 through miR-145-5p repression by G9a, indicating that STAT3 is a reliable therapeutic target against EGFR-TKI-resistant lung cancers.

Topics: A549 Cells; Animals; Benzofurans; Cell Movement; Cell Survival; Drug Resistance, Neoplasm; ErbB Receptors; Gene Knockdown Techniques; Histocompatibility Antigens; Histone-Lysine N-Methyltransferase; Humans; Imidazoles; Lung Neoplasms; Male; Mice; Mice, Inbred NOD; Mice, SCID; MicroRNAs; Naphthoquinones; Nuclear Factor 90 Proteins; Protein Kinase Inhibitors; Receptor, ErbB-3; STAT3 Transcription Factor; Xenograft Model Antitumor Assays

YM-155 has been proven to be an efficient antitumor suppressor in non-small cell lung cancer (NSCLC) cells. However, the suppressive effect of YM-155 on the expression of survivin is not sufficient and has a short half-life. MS-275, a histone deacetylase inhibitor, has significant antitumor capacity with a relatively long half-life. Our study explored whether MS-275 could enhance the inhibitory effect of YM-155 on LUAD proliferation.. To investigate the synergistic effect of MS-275 and YM-155, we employed methyl thiazolyl tetrazolium and colony formation assays to access the inhibition effect of MS-275, YM-155, or a combination in A549 and HCC827 cell lines. We then detected the effect of MS-275 and YM-155 on the expression of survivin and pro-apoptotic proteins by Western blot and miR-138 or miR-195 expression by quantitative PCR. We also analyzed the methylation level of microRNAs (miRNAs) using methylation-sensitive quantitative PCR. Finally, we investigated the interaction between miRNAs and survivin by luciferase reporter assay.. MS-275 facilitated an inhibitory effect of YM-155 on lung adenocarcinoma cell proliferation. MS-275 can upregulate the level of acetylated H3, promote the degradation of DNA methyltransferases, and inhibit the methylation of miR-138 and miR-195 genes to elevate the expression of miR-138 and miR-195. Moreover, miR-138 and miR-195 showed a synergistic effect with YM-155 by directly binding to the 3 untranslated region of survivin to attenuate its expression.. For the first time, we report the synergistic effective of MS-275 and YM-155 and suggest a new direction for the future application of YM-155.

Topics: A549 Cells; Adenocarcinoma of Lung; Animals; Benzamides; Cell Line, Tumor; Cell Proliferation; Cell Survival; DNA Methylation; Down-Regulation; Drug Synergism; Gene Expression Regulation, Neoplastic; Histones; Humans; Imidazoles; Lung Neoplasms; Mice; MicroRNAs; Naphthoquinones; Pyridines; Survivin; Xenograft Model Antitumor Assays

Lung cancer remains 23% of cancer-related death worldwide, ranking on first place for men and second place for women. Almost each cancer type has a great deal in common, overexpression of the apoptosis inhibitor survivin. Chemotherapy with anticancer drugs is leading to side effects. Drug targeting by the use of nanobubbles is a useful strategy to reduce side effects. Nanobubbles in cancer are one of the most investigated carriers in the last years. The size of nanobubbles (1-500 nm) is bigger than the pore size of healthy tissues, but smaller than the pores of cancer tissues. Thus, it is not possible for the drug to leave the blood stream and enter the tissue, but it can enter the cancer tissue through the pores, where it can accumulate. Therefore, the probability of undesired side effects decreases. For that reason, the development of nanobubbles containing paclitaxel and survivin inhibitor sepantronium bromide (YM155) were carried out. Characterization studies in terms of particle size, size distribution, zeta potential and morphology, and investigation of their effects on lung cancer cells were performed. To the best of our knowledge, there is no information in the literature about combining paclitaxel and YM155 loaded nanobubbles with ultrasound exposure.

Topics: A549 Cells; Antineoplastic Agents, Phytogenic; Cell Survival; Drug Liberation; Humans; Imidazoles; Lung Neoplasms; Nanostructures; Naphthoquinones; Paclitaxel; Survivin

YM155, an inhibitor of interleukin enhancer-binding factor 3 (ILF3), significantly suppresses cancer stemness property, implying that ILF3 contributes to cell survival of cancer stem cells. However, the molecular function of ILF3 inhibiting cancer stemness remains unclear. This study aimed to uncover the potential function of ILF3 involving in cell survival of epidermal growth factor receptor (EGFR)-positive lung stem-like cancer, and to investigate the potential role to improve the efficacy of anti-EGFR therapeutics.. The association of EGFR and ILF3 in expression and regulations was first investigated in this study. Lung cancer A549 cells with deprivation of ILF3 were created by the gene-knockdown method and then RNAseq was applied to identify the putative genes regulated by ILF3. Meanwhile, HCC827- and A549-derived cancer stem-like cells were used to investigate the role of ILF3 in the formation of cancer stem-like tumorspheres.. We found that EGFR induced ILF3 expression, and YM155 reduced EGFR expression. The knockdown of ILF3 reduced not only EGFR expression in mRNA and protein levels, but also cell proliferation in vitro and in vivo, demonstrating that ILF3 may play an important role in contributing to cancer cell survival. Moreover, the knockdown and inhibition of ILF3 by shRNA and YM155, respectively, reduced the formation and survival of HCC827- and A549-derived tumorspheres through inhibiting ErbB3 (HER3) expression, and synergized the therapeutic efficacy of afatinib, a tyrosine kinase inhibitor, against EGFR-positive A549 lung cells.. This study demonstrated that ILF3 plays an oncogenic like role in maintaining the EGFR-mediated cellular pathway, and can be a therapeutic target to improve the therapeutic efficacy of afatinib. Our results suggested that YM155, an ILF3 inhibitor, has the potential for utilization in cancer therapy against EGFR-positive lung cancers.

Topics: A549 Cells; Afatinib; Animals; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Synergism; ErbB Receptors; Humans; Imidazoles; Lung Neoplasms; Male; Mice; Mice, Inbred NOD; Mice, SCID; Molecular Targeted Therapy; Naphthoquinones; Neoplastic Stem Cells; Nuclear Factor 90 Proteins; Phosphorylation; Protein Kinase Inhibitors; Random Allocation; Xenograft Model Antitumor Assays

Resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as erlotinib and gefitinib, is a major clinical problem in the treatment of patients with non-small cell lung cancer (NSCLC). YM155 is a survivin small molecule inhibitor and has been demonstrated to induce cancer cell apoptosis and autophagy. EGFR-TKIs have been known to induce cancer cell autophagy. In this study, we showed that YM155 markedly enhanced the sensitivity of erlotinib to EGFR-TKI resistant NSCLC cell lines H1650 (EGFR exon 19 deletion and PTEN loss) and A549 (EGFR wild type and KRAS mutation) through inducing autophagy-dependent apoptosis and autophagic cell death. The effects of YM155 combined with erlotinib on apoptosis and autophagy inductions were more obvious than those of YM155 in combination with survivin knockdown by siRNA transfection, suggesting that YM155 induced autophagy and apoptosis in the NSCLC cells partially depend on survivin downregulation. Meanwhile, we found that the AKT/mTOR pathway is involved in modulation of survivin downregulation and autophagy induction caused by YM155. In addition, YM155 can induce DNA damage in H1650 and A549 cell lines. Moreover, combining erlotinib further augmented DNA damage by YM155, which were retarded by autophagy inhibitor 3MA, or knockdown of autophagy-related protein Beclin 1, revealing that YM155 induced DNA damage is autophagy-dependent. Similar results were also observed in vivo xenograft experiments. Therefore, combination of YM155 and erlotinib offers a promising therapeutic strategy in NSCLC with EGFR-TKI resistant phenotype.

Topics: Antineoplastic Agents; Apoptosis; Autophagy; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Resistance, Neoplasm; ErbB Receptors; Erlotinib Hydrochloride; Humans; Imidazoles; Lung Neoplasms; Naphthoquinones; Protein Kinase Inhibitors; Survivin

Cancer stem cell survival is the leading factor for tumor recurrence after tumor-suppressive treatments. Therefore, specific and efficient inhibitors of cancer stemness must be discovered for reducing tumor recurrence. YM155 has been indicated to significantly reduce stemness-derived tumorsphere formation. However, the pharmaceutical mechanism of YM155 against cancer stemness is unclear. This study investigated the potential mechanism of YM155 against cancer stemness in lung cancer. Tumorspheres derived from epidermal growth factor receptor (EGFR)-mutant HCC827 and EGFR wild-type A549 cells expressing higher cancer stemness markers (CD133, Oct4, and Nanog) were used as cancer stemness models. We observed that EGFR autophosphorylation (Y1068) was higher in HCC827- and A549-derived tumorspheres than in parental cells; this autophosphorylation induced tumorsphere formation by activating G9a-mediated stemness. Notably, YM155 inhibited tumorsphere formation by blocking the autophosphorylation of EGFR and the EGFR-G9a-mediated stemness pathway. The chemical and genetic inhibition of EGFR and G9a revealed the significant role of the EGFR-G9a pathway in maintaining the cancer stemness property. In conclusion, this study not only revealed that EGFR could trigger tumorsphere formation by elevating G9a-mediated stemness but also demonstrated that YM155 could inhibit this formation by simultaneously blocking EGFR autophosphorylation and G9a activity, thus acting as a potent agent against lung cancer stemness.

Topics: Afatinib; Antineoplastic Agents; Cell Line, Tumor; Drug Evaluation, Preclinical; ErbB Receptors; Gene Expression Regulation, Neoplastic; Histocompatibility Antigens; Histone-Lysine N-Methyltransferase; Humans; Imidazoles; Lung Neoplasms; Methylation; Naphthoquinones; Octamer Transcription Factor-3; Phosphorylation; Quinazolines; RNA, Messenger

YM155 (sepantronium bromide) has been evaluated in clinical trials as a survivin suppressant, but despite positive signals from early work, later studies were negative. Clarification of the mechanism of action of YM155 is important for its further development. YM155 affects cells in a cell cycle-specific manner. When cells are in G1, YM155 prevented their progression through the S phase, leaving the cells at G1/S when exposed to YM155. Passage through mitosis from G2 is also defective following YM155 exposure. In this study, YM155 did not behave like a typical DNA intercalator in viscosity, circular dichroism, and absorption spectroscopy studies. In addition, molecular modeling experiments ruled out YM155 DNA interaction to produce DNA intercalation. We show that YM155 inhibited topoisomerase 2α decatenation and topoisomerase 1-mediated cleavage of DNA, suggesting that YM155 inhibits the enzyme function. Consistent with these findings, DNA double-strand break repair was also inhibited by YM155.

Topics: Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Cycle Checkpoints; Cell Line, Tumor; DNA Breaks; DNA Repair; DNA Replication; Humans; Imidazoles; Lung Neoplasms; Naphthoquinones; Topoisomerase Inhibitors

The NF-κB pathway is overexpressed in non-small cell lung cancers (NSCLC) and contributes to the poor prognosis and high mortality characterizing this malignancy. Silencing the p50 and p65 NF-κB subunits in the NSCLC H1299 cell line led to profound loss in cell viability and downregulated anti-apoptotic proteins survivin and Mcl1. We also showed that a survivin suppressant, the dioxonaphthoimidazolium YM155, and its structural analog AB1 arrested the growth of H1299 cells at nanomolar concentrations. Both compounds were apoptogenic and suppressed survivin and other anti-apoptotic proteins (Mcl1, Bcl-2, Bcl-xl) in a dose- and/or time-dependent manner. YM155 and AB1 did not affect the expression of key proteins (IκBα, p65, p50) involved in NF-κB signaling. Stable IκBα levels suggest that the NF-κB/IκB complex and proteins upstream of IκBα, were not targeted. Neither did the compounds intercept the nuclear translocation of the p50 and p65 subunits. On the other hand, YM155 and AB1 suppressed the phosphorylation of the p50 subunit at Ser337 which is critical in promoting the binding of NF-κB dimers to DNA. Both compounds duly impeded the binding of NF-κB dimers to DNA and attenuated transcriptional activity of luciferase-transfected HEK293 cells controlled by NF-κB response elements. We propose that the "silencing" the NF-κB pathway effected by these compounds contributed to their potent apoptogenic effects on H1299. Notwithstanding, the mechanism(s) involved in their ability to abolish phosphorylation of p50 remains to be elucidated. Taken together, these results disclose a novel facet of functionalized dioxonaphthoimidazoliums that could account for their potent cell killing property.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Chlorambucil; HEK293 Cells; Humans; Imidazoles; Lung Neoplasms; Myeloid Cell Leukemia Sequence 1 Protein; Naphthoquinones; NF-kappa B p50 Subunit; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Transcription Factor RelA

Photodynamic therapy (PDT) represents a rapidly developing alternative treatment for various types of cancers. Although considered highly effective, cancer cells can exploit various mechanisms, including the upregulation of apoptosis inhibitors, to overcome the cytotoxic effect of PDT. Survivin, a member of the inhibitor of apoptosis protein family, is known to play a critical role in cancer progression and therapeutic resistance and therefore represents a potential therapeutic target. The aim of this study was to investigate whether YM155, a small molecule inhibitor of survivin expression, can potentiate the cytotoxic effect of hypericin-mediated PDT (HY-PDT). Accordingly, two cell lines resistant to HY-PDT, HT-29 (colorectal adenocarcinoma) and A549 (lung adenocarcinoma), were treated either with HY-PDT alone or in combination with YM155. The efficacy of different treatment regimens was assessed by MTT assay, flow cytometry analysis of metabolic activity, viability, phosphatidylserine externalisation, mitochondrial membrane potential and caspase-3 activity and immunoblotting for the cleavage of poly (ADP-ribose) polymerase (PARP). Here we show for the first time that the repression of survivin expression by YM155 is effective in sensitizing HT-29 and A549 cells to HY-PDT, as measured by the decrease in cell viability and induction of apoptosis. Combined treatment with hypericin and YM155 led to a more severe dissipation of the mitochondrial membrane potential and caused an increase in caspase-3 activation and subsequent PARP cleavage. Our results demonstrate that the repression of survivin expression by YM155 potentially represents a novel alternative strategy to increase the efficacy of HY-PDT in cancer cells that are otherwise weakly responsive or non-responsive to treatment.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Anthracenes; Antineoplastic Agents; Autophagy; Caspase 3; Cell Cycle; Cell Line, Tumor; Cell Survival; Colorectal Neoplasms; Drug Resistance, Neoplasm; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Membrane Potential, Mitochondrial; Naphthoquinones; Perylene; Photochemotherapy; Photosensitizing Agents; Survivin

We use a mathematical model to investigate cancer resistance to radiation, based on dedifferentiation of non-stem cancer cells into cancer stem cells. Experimental studies by Iwasa 2008, using human non-small cell lung cancer (NSCLC) cell lines in mice, have implicated the inhibitor of apoptosis protein survivin in cancer resistance to radiation. A marked increase in radio-sensitivity was observed, after inhibiting survivin expression with a specific survivin inhibitor YM155 (sepantronium bromide). It was suggested that these observations are due to survivin-dependent dedifferentiation of non-stem cancer cells into cancer stem cells. Here, we confirm this hypothesis with a mathematical model, which we fit to Iwasa's data on NSCLC in mice. We investigate the timing of combination therapies of YM155 administration and radiation. We find an interesting dichotomy. Sometimes it is best to hit a cancer with a large radiation dose right at the beginning of the YM155 treatment, while in other cases, it appears advantageous to wait a few days until most cancer cells are sensitized and then radiate. The optimal strategy depends on the nature of the cancer and the dose of radiation administered.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Cell Dedifferentiation; Cell Line, Tumor; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Mathematical Concepts; Mice; Models, Biological; Naphthoquinones; Neoplastic Stem Cells; Radiation Tolerance

Survivin, a member of the inhibitor of apoptosis protein family, is an attractive target for cancer therapy. We investigated the effects of YM155, a small molecule inhibitor of survivin expression, on the radiosensitivity of human non-small cell lung cancer (NSCLC) cell lines and elucidated a relationship between the cellular localization of survivin and DNA double-strand break repair.. The cellular distribution of survivin was determined by Western blotting of subcellular fractions and by immunofluorescent staining in A549 NSCLC cells. Radiation-induced DNA damage was evaluated based on histone H2AX phosphorylation and foci formation. The relationship between the cellular localization of survivin and DNA double-strand break repair was analyzed by Western blotting and co-immunoprecipitations.. YM155 down-regulated survivin expression in NSCLC cells in a concentration- and time-dependent manner. An in vitro clonogenic survival assay revealed that YM155 increased the sensitivity of NSCLC cells to radiation. After irradiation, we observed a rapid accumulation of survivin in the nucleus. An immunofluorescent analysis of histone x03B3;-H2AX demonstrated that the inhibition of survivin expression by YM155 resulted in impaired DNA double-strand break repair. Co-immunoprecipitation assays using nuclear extracts revealed an interaction between survivin, Ku70, x03B3;-H2AX, and DNA-PKcs. Furthermore, S2056 autophosphorylation of DNA-PKcs was reduced in survivin-depleted cells.. These results suggested that YM155 sensitized NSCLC cells to radiation, at least in part by inhibiting DNA repair and enhancing apoptosis via the down-regulation of survivin expression. YM155 pretreatment inhibited DNA-PKcs autophosphorylation at S2056. Nuclear survivin was involved in DNA double-strand break repair via interactions with members of the DNA double-strand break repair machinery.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Nucleus; Cell Survival; DNA Breaks, Double-Stranded; DNA Repair; Dose-Response Relationship, Drug; Down-Regulation; Gene Expression Regulation, Neoplastic; Histones; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Naphthoquinones; Phosphorylation; Radiation-Sensitizing Agents; Survivin

Survivin, an apoptotic inhibitor, is overexpressed in the majority of human tumor types and represents a novel target for anticancer therapy. Taxanes induce a mitotic cell-cycle block through the inhibition of microtubule depolymerization, with subsequent elevated expression/stabilization of survivin. We investigated the administration of survivin suppressant YM155 monobromide (YM155), in combination with docetaxel, in a human non-small-cell lung cancer (NSCLC) xenograft model. Animals received a 7-day continuous infusion of YM155, 2 mg/kg, and/or three bolus doses of docetaxel, 20 mg/kg, according to three dosing schedules: YM155 administered concomitantly with docetaxel, before docetaxel, and after docetaxel. YM155 administered either concomitantly with or before docetaxel showed significant antitumor activity (tumor regression ≥ 99%), with complete regression of the established human NSCLC-derived tumors in mice (eight of eight and seven of eight animals, respectively). Significantly fewer complete responses (three of eight animals) were achieved when YM155 was administered after docetaxel. No statistically significant decreases in body weight were observed in the combination versus docetaxel groups. YM155 administered concomitantly with docetaxel resulted in significant decreases in mitotic and proliferative indices, and in a significant increase in the apoptosis index. Elevated survivin expression was seen in tumors from mice treated with docetaxel alone; a significant reduction in survivin expression was seen in tumors from mice treated with YM155 alone or in combination with docetaxel, but not in the control group. These results indicate that in a human NSCLC xenograft model YM155 in combination with docetaxel diminished the accumulation of survivin by docetaxel and induced more intense apoptosis and enhanced antitumor activity, compared with single-agent YM155 or docetaxel.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Docetaxel; Drug Synergism; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Male; Mice; Mice, Nude; Mitosis; Naphthoquinones; Survivin; Taxoids; Xenograft Model Antitumor Assays

Survivin, a member of the inhibitor of apoptosis protein family, is an attractive target for cancer therapy. We have now investigated the effects of the combination of YM155, a novel small-molecule inhibitor of survivin expression, and platinum compounds (cisplatin and carboplatin) on human non-small cell lung cancer (NSCLC) cell lines.. The anti-cancer efficacy of YM155 in combination with platinum compounds was evaluated on the basis of cell death and progression of tumour xenografts. Platinum compound-induced DNA damage was evaluated by immunofluorescence analysis of histone gamma-H2AX.. Immunofluorescence analysis of histone gamma-H2AX showed that YM155 delayed the repair of double-strand breaks induced in nuclear DNA by platinum compounds. The combination of YM155 and platinum compounds also induced synergistic increases both in the number of apoptotic cells and in the activity of caspase-3. Finally, combination therapy with YM155 and platinum compounds delayed the growth of NSCLC tumour xenografts in nude mice to an extent greater than that apparent with either treatment modality alone.. These results suggest that YM155 sensitises tumour cells to platinum compounds both in vitro and in vivo, and that this effect is likely attributable to the inhibition of DNA repair and consequent enhancement of apoptosis.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carboplatin; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; DNA Damage; Histones; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Microtubule-Associated Proteins; Naphthoquinones; Phosphorylation; Survivin

Survivin, a member of the inhibitor of apoptosis protein family, is an attractive target for cancer therapy. We have now investigated the effect of YM155, a small-molecule inhibitor of survivin expression, on the sensitivity of human non-small cell lung cancer (NSCLC) cell lines to gamma-radiation.. The radiosensitizing effect of YM155 was evaluated on the basis of cell death, clonogenic survival, and progression of tumor xenografts. Radiation-induced DNA damage was evaluated on the basis of histone H2AX phosphorylation and foci formation.. YM155 induced down-regulation of survivin expression in NSCLC cells in a concentration- and time-dependent manner. A clonogenic survival assay revealed that YM155 increased the sensitivity of NSCLC cells to gamma-radiation in vitro. The combination of YM155 and gamma-radiation induced synergistic increases both in the number of apoptotic cells and in the activity of caspase-3. Immunofluorescence analysis of histone gamma-H2AX also showed that YM155 delayed the repair of radiation-induced double-strand breaks in nuclear DNA. Finally, combination therapy with YM155 and gamma-radiation delayed the growth of NSCLC tumor xenografts in nude mice to a greater extent than did either treatment modality alone.. These results suggest that YM155 sensitizes NSCLC cells to radiation both in vitro and in vivo, and that this effect of YM155 is likely attributable, at least in part, to the inhibition of DNA repair and enhancement of apoptosis that result from the down-regulation of survivin expression. Combined treatment with YM155 and radiation warrants investigation in clinical trials as a potential anticancer strategy.

Topics: Animals; Apoptosis; Carcinoma, Non-Small-Cell Lung; Caspase 3; Combined Modality Therapy; DNA Repair; Female; Fluorescent Antibody Technique; Gamma Rays; Histones; Humans; Imidazoles; Immunoblotting; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Microtubule-Associated Proteins; Naphthoquinones; Neoplasm Proteins; Radiation Tolerance; Radiation-Sensitizing Agents; Survival Rate; Survivin; Tumor Cells, Cultured; Tumor Stem Cell Assay; Xenograft Model Antitumor Assays