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Supplementary Materials and Methods, Tables 1-4, Figures 1-5 from Hyperactivation of the Insulin-like Growth Factor Receptor I Signaling Pathway Is an Essential Event for Cisplatin Resistance of Ovarian Cancer Cells

Platinum plays a central role in the therapy of ovarian cancer, and the emergence of platinum resistance is a major obstacle for clinical management of the disease. We treated A2780 ovarian cancer cells by weekly cycles of cisplatin over a period of 6 months and unveiled that enhanced insulin-like growth factor I receptor (IGF-IR) expression and autocrine IGF-I are associated with hyperactivation of the IGF-IR and phosphatidylinositol-3-OH kinase (PI3K) pathways in cisplatin-resistant cells. IGF-IR expression levels increased during treatment cycles and correlated with cisplatin resistance. Purified IGF-I induced cisplatin resistance in diverse ovarian cancer cell lines, and small molecule inhibitors proved that IGF-IR and PI3K are essential for cisplatin resistance. Similar results were obtained with BG-1 ovarian cancer cells. Cytogenetic and array comparative genomic hybridization analyses revealed selection and de novo formation of chromosomal alterations during resistance development. An analysis of gene expression profiles of primary ovarian carcinomas identified the regulatory subunit PIK3R2 of PI3-kinase as a significant negative prognosis factor for ovarian cancer. We conclude that targeting the IGF-IR and the PI3K pathways is a promising new strategy to treat cisplatin-resistant ovarian carcinomas. [Cancer Res 2009;69(7):2996–3003]

The acetylome is important for maintaining the homeostasis of cells. Abnormal changes can result in the pathogenesis of immunological or neurological diseases, and degeneration can promote the manifestation of cancer. In particular, pharmacological intervention in the acetylome with pan‐histone deacetylase (HDAC) inhibitors is clinically validated. However, these drugs exhibit an undesirable risk‐benefit profile due to severe side effects. Selective HDAC inhibitors might promote patient compliance and represent a valuable opportunity in personalised medicine. Therefore, we envisioned the development of HDAC6‐selective inhibitors. During our lead structure identification, we demonstrated that an alkoxyurea‐based connecting unit proves to be beneficial for HDAC6 selectivity and established the synthesis of alkoxyurea‐based hydroxamic acids. Herein, we report highly potent N‐alkoxyurea‐based hydroxamic acids with improved HDAC6 preference compared to nexturastat A. We further validated the biological activity of these oxa analogues of nexturastat A in a broad subset of leukaemia cell lines and demonstrated their superior anti‐proliferative properties compared to nexturastat A., A hydroxylamine connecting unit facilitates HDAC6 preference: The derivatization of nexturastat A with alkoxyurea connecting units is reported. This modification resulted in an increased preference for HDA6 and increased antiproliferative properties in haematological cancer cell lines.

Inhibition of more than one cancer‐related pathway by multi‐target agents is an emerging approach in modern anticancer drug discovery. Here, based on the well‐established synergy between histone deacetylase inhibitors (HDACi) and alkylating agents, we present the discovery of a series of alkylating HDACi using a pharmacophore‐linking strategy. For the parallel synthesis of the target compounds, we developed an efficient solid‐phase‐supported protocol using hydroxamic acids immobilized on resins (HAIRs) as stable and versatile building blocks for the preparation of functionalized HDACi. The most promising compound, 3 n, was significantly more active in apoptosis induction, activation of caspase 3/7, and formation of DNA damage (γ‐H2AX) than the sum of the activities of either active principle alone. Furthermore, to demonstrate the utility of our preloaded resins, the HAIR approach was successfully extended to the synthesis of a proof‐of‐concept proteolysis‐targeting chimera (PROTAC), which efficiently degrades histone deacetylases., Hydroxamic acids immobilized on resins (HAIRs) were developed and utilized for the library synthesis of DNA‐alkylating HDAC inhibitors and a proof‐of‐concept HDAC degrader (PROTAC). A hybrid compound based on the pharmacophores of chlorambucil and panobinostat was identified as the most promising chimeric HDAC inhibitor and demonstrated improved anticancer properties compared to the sum of the activities of either pharmacophore alone.

The monoclonal antibody cetuximab recognizes domain III of the epithelial growth factor receptor (EGFR) with high-affinity and is an important element in the treatment of several malignancies that overexpress non-mutated wild-type EGFR. In order to create an EGFR recognizing chimeric antigen receptor (CAR) for cellular immunotherapy of head and neck squamous cell carcinoma (HNSCC), we rationally designed single chain fragments of different lengths based on the cetuximab variable heavy and light chains. We then cloned the different cetuximab fragments into our second generation CAR construct, expressed CARs on primary human T-cells from healthy donors using mono- or biscistronic lentiviral vectors and tested the stability, functionality and specificity of the CARs. Our smallest CAR construct was most efficient with greatly improved vector production and T-cell transduction efficacy. Finally, we demonstrated that the new cetuximab CAR construct expressed on T-cells is highly reactive against EGFR-positive HNSCCs and also malignant cells from other solid cancer entities. In conclusion, we generated an optimized high-affinity EGFR CAR construct for the next steps in cancer immunotherapy, which need to focus on the development of armored CAR T-cells that will be more resistant and effective in the hostile microenvironment present in solid cancers.

Occurrence of cisplatin-resistance in bladder cancer is frequent and results in disease progression. Thus, novel therapeutic approaches are a high medical need for patients suffering from chemotherapy failure. The purpose of this study was to test the combination of the DNA methyltransferase inhibitor decitabine (DAC) with the histone deacetylase inhibitor entinostat (ENT) in bladder cancer cells with different platinum sensitivities: J82, cisplatin-resistant J82CisR, and RT-112. Intermittent treatment of J82 cells with cisplatin resulted in the six-fold more cisplatin-resistant cell line J82CisR. Combinations of DAC and/or ENT plus cisplatin could not reverse chemoresistance. However, the combination of DAC and ENT acted cytotoxic in a highly synergistic manner as shown by Chou-Talalay analysis via induction of apoptosis and cell cycle arrest. Importantly, this effect was cancer cell-selective as no synergism was found for the combination in the non-cancerous urothelial cell line HBLAK. Expression analysis indicated that epigenetic treatment led to up-regulation of forkhead box class O1 (FoxO1) and further activated proapoptotic Bim and the cell cycle regulator p21 and reduced expression of survivin in J82CisR. In conclusion, the combination of DAC and ENT is highly synergistic and has a promising potential for therapy of bladder cancer, particularly in cases with platinum resistance.

Occurrence of cisplatin-resistance in bladder cancer is frequent and results in disease progression. Thus, novel therapeutic approaches are a high medical need for patients suffering from chemotherapy failure. The purpose of this study was to test the combination of the DNA methyltransferase inhibitor decitabine (DAC) with the histone deacetylase inhibitor entinostat (ENT) in bladder cancer cells with different platinum sensitivities: J82, cisplatin-resistant J82CisR, and RT-112. Intermittent treatment of J82 cells with cisplatin resulted in the six-fold more cisplatin-resistant cell line J82CisR. Combinations of DAC and/or ENT plus cisplatin could not reverse chemoresistance. However, the combination of DAC and ENT acted cytotoxic in a highly synergistic manner as shown by Chou-Talalay analysis via induction of apoptosis and cell cycle arrest. Importantly, this effect was cancer cell-selective as no synergism was found for the combination in the non-cancerous urothelial cell line HBLAK. Expression analysis indicated that epigenetic treatment led to up-regulation of forkhead box class O1 (FoxO1) and further activated proapoptotic Bim and the cell cycle regulator p21 and reduced expression of survivin in J82CisR. In conclusion, the combination of DAC and ENT is highly synergistic and has a promising potential for therapy of bladder cancer, particularly in cases with platinum resistance.

The multicomponent synthesis of a mini-library of histone deacetylase inhibitors with imidazo[1,2- a]pyridine-based cap groups is presented. The biological evaluation led to the discovery of the hit compound MAIP-032 as a selective HDAC6 inhibitor with promising anticancer activity. The X-ray structure of catalytic domain 2 from Danio rerio HDAC6 complexed with MAIP-032 revealed a monodentate zinc-binding mode.

There is increasing evidence that histone deacetylase (HDAC) inhibitors can (re)sensitize cancer cells for chemotherapeutics via "epigenetic priming". In this work, we describe the synthesis of a series of class I-selective HDAC inhibitors with 2-aminoanilides as zinc-binding groups. Several of the synthesized compounds revealed potent inhibition of the class I HDAC isoforms HDAC1, HDAC2, and/or HDAC3 and promising antiproliferative effects in the human ovarian cancer cell line A2780 and the human squamous carcinoma cell line Cal27. Selected compounds were investigated in a cellular model of platinum resistance. In particular, compound 2a revealed potent chemosensitizing properties and full reversal of cisplatin resistance in Cal27CisR cells. This effect is related to a synergistic increase in caspase 3/7 activation and induction of apoptosis. Thus, this work demonstrates that pan-HDAC inhibition or dual class I/class IIb inhibition is not required for full reversal of cisplatin resistance.

Extracellular nucleotides mediate multiple physiological effects such as proliferation, differentiation, or induction of apoptosis through G protein–coupled P2Y receptors or P2X ion channels. Evaluation of the complete physiological role of nucleotides has long been hampered by a lack of potent and selective ligands for all P2 subtypes. Meanwhile, for most of the P2 receptors, selective ligands are available, but only a few potent and selective P2Y(2) receptor antagonists are described. This limits the understanding of the role of P2Y(2) receptors. The purpose of this study was to search for P2Y(2) receptor antagonists by a combinatorial screening of a library of around 415 suramin-derived compounds. Calcium fluorescence measurements at P2Y(2) receptors recombinantly expressed in human 1321N1 astrocytoma cells identified NF272 [8-(4-methyl-3-(3-phenoxycarbonylimino-benzamido)benzamido)-naphthalene-1,3,5-trisulfonic acid trisodium salt] as a competitive P2Y(2) receptor antagonist with a K(i) of 19 μM which is 14-fold more potent than suramin at this receptor subtype. The SCHILD analysis of competitive inhibition resulted in a pA(2) value of 5.03 ± 0.22 (mean ± SEM) with a slope not significantly different from unity. Among uracil-nucleotide–preferring P2Y receptors, NF272 shows a moderate selectivity over P2Y(4) (3.6-fold) and P2Y(6) (5.7-fold). However, NF272 is equipotent at P2Y(1), and even more potent at P2Y(11) and P2Y(12) receptors. Up to 250 μM, NF272 showed no cytotoxicity in MTT cell viability assays in 1321N1, HEK293, and OVCAR-3 cells. Further, NF272 was able to inhibit the ATP-induced calcium signal in OVCAR-3 cells demonstrated to express P2Y(2) receptors. In conclusion, NF272 is a competitive but non-selective P2Y(2) receptor antagonist with 14-fold higher potency than suramin lacking cytotoxic effects. Therefore, NF272 may serve as a lead structure for further development of P2Y(2) receptor antagonists. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11302-019-09663-4) contains supplementary material, which is available to authorized users.

High grade serous ovarian cancer (HGSOC) is the most common and aggressive ovarian cancer subtype with the worst clinical outcome due to intrinsic or acquired drug resistance. Standard treatment involves platinum compounds. Cancer development and chemoresistance is often associated with an increase in histone deacetylase (HDAC) activity. The purpose of this study was to examine the potential of HDAC inhibitors (HDACi) to increase platinum potency in HGSOC. Four HGSOC cell lines with different cisplatin sensitivity were treated with combinations of cisplatin and entinostat (class I HDACi), panobinostat (pan-HDACi), or nexturastat A (class IIb HDACi), respectively. Inhibition of class I HDACs by entinostat turned out superior in increasing cisplatin potency than pan-HDAC inhibition in cell viability assays (MTT), apoptosis induction (subG1), and caspase 3/7 activation. Entinostat was synergistic with cisplatin in all cell lines in MTT and caspase activation assays. MTT assays gave combination indices (CI values) &lt, 0.9 indicating synergism. The effect of HDAC inhibitors could be attributed to the upregulation of pro-apoptotic genes (CDNK1A, APAF1, PUMA, BAK1) and downregulation of survivin. In conclusion, the combination of entinostat and cisplatin is synergistic in HGSOC and could be an effective strategy for the treatment of aggressive ovarian cancer.

The fungus Aspergillus ochraceus was isolated from the Mediterranean sponge Agelas oroides. The initial fermentation of the fungus on solid rice medium yielded 16 known compounds (4–19). The addition of several inorganic salts to the rice medium mainly influenced the accumulation of these secondary metabolites. Fermentation of the fungus on white bean medium yielded the new waspergillamide B (1) featuring an unusual p-nitrobenzoic acid as partial structure. Moreover, two new compounds, ochraspergillic acids A and B (2 and 3), which are both adducts of dihydropenicillic acid and o- or p-aminobenzoic acid, were isolated from the co-culture of the fungus with Bacillus subtilis. Compound 2 was also detected in axenic fungal cultures following the addition of either anthranilic acid or tryptophan to the rice medium. The structures of the new compounds were established by 1D and 2DNMR experiments as well as from the HRMS data. The absolute configuration of 1 was elucidated following hydrolysis and derivatization of the amino acids using Marfey’s reagent. Viomellein (9) and ochratoxin B (18) exhibited strong cytotoxicity against the A2780 human ovarian carcinoma cells with IC50 values of 5.0 and 3.0 µM, respectively.

Purpose. Several studies have shown that natural compounds like resveratrol or ellagic acid have anticancer and antioxidant properties and can stimulate apoptosis in many cancer cell lines. The aim of this study was to elucidate if resveratrol or ellagic acid, respectively, could improve the efficacy of cisplatin in ovarian cancer. Methods. As a cellular resistance model, the epithelial ovarian cancer cell line A2780 and its cisplatin-resistant subclone A2780CisR were used. A2780CisR was obtained by intermittent treatment of A2780 with cisplatin for 26 weekly cycles and showed a 4-6-fold increased resistance towards cisplatin compared to A2780. Results. Pretreatment with resveratrol or ellagic acid 48 h prior to treatment with cisplatin showed a moderate enhancement of cisplatin cytotoxicity in A2780CisR cells (shift factors were 1.6 for ellagic acid and 2.5 for resveratrol). However, intermittent treatment of A2780 with cisplatin for 26 weekly cycles in permanent presence of resveratrol or ellagic acid, respectively, completely prevented the development of cisplatin resistance. The generated cell lines named A2780Resv and A2780Ellag displayed functional characteristics (migration, proliferation, apoptosis, activation of ErbB3, ROS generation) similar to the parental cell line A2780. Conclusion. In conclusion, weekly intermittent treatment cycles of cisplatin-sensitive ovarian cancer cells with cisplatin retain cisplatin chemosensitivity in permanent presence of ellagic acid or resveratrol, respectively, whereas clinically relevant cisplatin chemoresistance develops in the absence of ellagic acid or resveratrol. Use of natural phenolic compounds may thus be a promising approach to prevent cisplatin resistance in ovarian cancer.

Oxime-based CO-releasing molecules (oximeCORMs) were immobilized with a catechol-modified backbone on maghemite iron oxide nanoparticles (IONPs) to give oximeCORM@IONP. The CO release from the free and immobilized oximeCORMs was measured using the standard myoglobin assay. The oximeCORM-nanoparticles were coated with dextran for improved water solubility and confined into an alginate shell for protection and separation from the surrounding myoglobin assay to allow for CO release studies by UV/Vis absorption without interference from highly-absorptive oximeCORM@IONP. Half-lifes of the oxime-based polymer-confined alginate@dextran@oximeCORM@IONPs were estimated at 20 °C to 814 ± 23 min, at 37 °C to 346 ± 83 min and at 50 °C to 73 ± 1 min. The alginate@dextran@oximeCORM@IONP composite showed a further decrease of the half-life of CO release to 153 ± 27 min at 37 °C through local magnetic heating of the susceptible iron oxide nanoparticles with application of an external alternating magnetic field (31.7 kA m(-1), 247 kHz, 39.9 mTesla). The activation energy for the CO release from molecular dicarbonylchlorido(imidazole-2-carbaldehydeoxime)(alkoxycarbonyl)ruthenium(ii) complexes is determined to be ∼100 kJ mol(-1) for five different imidazole-oxime derivatives.

A mini library of HDAC inhibitors with peptoid-based cap groups was synthesized using an efficient multicomponent approach. Four compounds were identified as potent HDAC6 inhibitors with a selectivity over other HDAC isoforms. The most potent HDAC6 inhibitor revealed remarkable chemosensitizing properties and completely reverted the cisplatin resistance in Cal27 CisR cells.

Ovarian cancer is the deadliest gynecologic cancer due to lack of early effective diagnosis and development of resistance to platinum-based chemotherapy. Several studies reported that adenosine concentrations are higher in tumor microenvironment than in non-tumor tissue. This finding inspired us to study the role of adenosine in ovarian cancer cells and to investigate if adenosine pathways offer new treatment options urgently needed to prevent or overcome chemoresistance. The ovarian cancer cell lines HEY, A2780, and its cisplatin-resistant subline A2780CisR were used in this study. Expression and functional activity of adenosine receptors were investigated by RT-PCR, Western blotting, and cAMP assay. A1 and A2B adenosine receptors were expressed and functionally active in all three cell lines. Adenosine showed moderate cytotoxicity (MTT-IC50 values were between 700 and 900 μM) and induced apoptosis in a concentration-dependent manner by increasing levels of sub-G1 and cleaved PARP. Apoptosis was diminished by QVD-OPh, confirming caspase-dependent induction of apoptosis. Forty-eight hours pre-incubation of adenosine prior to cisplatin significantly enhanced cisplatin-induced cytotoxicity in a synergistic manner and increased apoptosis. SLV320 or PSB603, selective A1 and A2B antagonists, was not able to inhibit adenosine-induced increase in cisplatin cytotoxicity or apoptosis whereas dipyridamole, a nucleoside transporter inhibitor, completely abrogated both effects. Mechanistically, adenosine increased pAMPK and reduced pS6K which was prevented by dipyridamole. In conclusion, application of adenosine prior to cisplatin could be a new therapeutic option to increase the potency of cisplatin in a synergistic manner and thus overcome platinum resistance in ovarian cancer.

In this work we aimed to develop parasite-selective histone deacetylase inhibitors (HDAC) inhibitors with activity against the disease-causing asexual blood stages of Plasmodium as well as causal prophylactic and/or transmission blocking properties. We report the design, synthesis, and biological testing of a series of 13 terephthalic acid-based HDAC inhibitors. All compounds showed low cytotoxicity against human embryonic kidney (HEK293) cells (IC50: 8–>51 μm), with 11 also having sub-micromolar in vitro activity against drug-sensitive (3D7) and multidrug-resistant (Dd2) asexual blood-stage P. falciparum parasites (IC50≈0.1–0.5 μm). A subset of compounds were examined for activity against early- and late-stage P. falciparum gametocytes and P. berghei exo-erythrocytic-stage parasites. While only moderate activity was observed against gametocytes (IC50>2 μm), the most active compound (N1-((3,5-dimethylbenzyl)oxy)-N4-hydroxyterephthalamide, 1 f) showed sub-micromolar activity against P. berghei exo-erythrocytic stages (IC50 0.18 μm) and >270-fold better activity for exo-erythrocytic forms than for HepG2 cells. This, together with asexual-stage in vitro potency (IC50≈0.1 μm) and selectivity of this compound versus human cells (SI>450), suggests that 1 f may be a valuable starting point for the development of novel antimalarial drug leads with low host cell toxicity and multi-stage anti-plasmodial activity.

In this work, we report the multicomponent synthesis of a focused histone deacetylase (HDAC) inhibitor library with peptoid-based cap groups and different zinc-binding groups. All synthesized compounds were tested in a cellular HDAC inhibition assay and an MTT assay for cytotoxicity. On the basis of their noteworthy activity in the cellular HDAC assays, four compounds were further screened for their inhibitory activity against recombinant HDAC1-3, HDAC6, and HDAC8. All four compounds showed potent inhibition of HDAC1-3 as well as significant inhibition of HDAC6 with IC50 values-in the submicromolar concentration range. Compound 4j, the most potent HDAC inhibitor in the cellular HDAC assay, revealed remarkable chemosensitizing properties and enhanced the cisplatin sensitivity of the cisplatin-resistant head-neck cancer cell line Cal27CisR by almost 7-fold. Furthermore, 4j almost completely reversed the cisplatin resistance in Cal27CisR. This effect is related to a synergistic induction of apoptosis as seen in the combination of 4j with cisplatin.

In this work we investigated the antiplasmodial activity of a series of HDAC inhibitors containing an alkoxyamide connecting-unit linker region. HDAC inhibitor 1a (LMK235), previously shown to be a novel and specific inhibitor of human HDAC4 and 5, was used as a starting point to rapidly construct a mini-library of HDAC inhibitors using a straightforward solid-phase supported synthesis. Several of these novel HDAC inhibitors were found to have potent in vitro activity against asexual stage Plasmodium falciparum malaria parasites. Representative compounds were shown to hyperacetylate P. falciparum histones and to inhibit deacetylase activity of recombinant PfHDAC1 and P. falciparum nuclear extracts. All compounds were also screened in vitro for activity against Plasmodium berghei exo-erythrocytic stages and selected compounds were further tested against late stage (IV and V) P. falciparum gametocytes. Of note, some compounds showed nanomolar activity against all three life cycle stages tested (asexual, exo-erythrocytic and gametocyte stages) and several compounds displayed significantly increased parasite selectivity compared to the reference HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). These data suggest that it may be possible to develop HDAC inhibitors that target multiple malaria parasite life cycle stages.

Bioactivity-guided chemical investigation of a co-culture of marine-derived micro-organisms has yielded one new steroid, 7β-hydroxycholesterol-1β-carboxylic acid (1) with an unprecedented carboxylic acid group at C-1, together with three known steroidal metabolites (2–4). The chemical structures and stereochemistry of the isolated compounds were unambiguously determined based on extensive 1D, 2D NMR and HR-ESI-MS measurements. The isolated compounds were assessed for their cytotoxic activity against four different human tumour cell lines K562 (leukaemia), HCT116 (colon), A2780 (ovary) and its cisplatin-resistant mutant (A2780 CisR), and they revealed moderate activities with IC50 values ranging from 10.0 to 100.0 μM.

The fungus Aspergillus ochraceus was isolated from the Mediterranean sponge Agelas oroides. The initial fermentation of the fungus on solid rice medium yielded 16 known compounds (4&ndash, 19). The addition of several inorganic salts to the rice medium mainly influenced the accumulation of these secondary metabolites. Fermentation of the fungus on white bean medium yielded the new waspergillamide B (1) featuring an unusual p-nitrobenzoic acid as partial structure. Moreover, two new compounds, ochraspergillic acids A and B (2 and 3), which are both adducts of dihydropenicillic acid and o- or p-aminobenzoic acid, were isolated from the co-culture of the fungus with Bacillus subtilis. Compound 2 was also detected in axenic fungal cultures following the addition of either anthranilic acid or tryptophan to the rice medium. The structures of the new compounds were established by 1D and 2DNMR experiments as well as from the HRMS data. The absolute configuration of 1 was elucidated following hydrolysis and derivatization of the amino acids using Marfey&rsquo, s reagent. Viomellein (9) and ochratoxin B (18) exhibited strong cytotoxicity against the A2780 human ovarian carcinoma cells with IC50 values of 5.0 and 3.0 &micro, M, respectively.

Background Widely established targeted therapies directed at triple negative breast cancer (TNBC) are missing. Classical chemotherapy remains the systemic treatment option. Cisplatin has been tested in TNBC but bears the disadvantage of resistance development. The purpose of this study was to identify resistance mechanisms in cisplatin-resistant TNBC cell lines and select targeted therapies based on these findings. Methods The TNBC cell lines HCC38 and MDA-MB231 were subjected to intermittent cisplatin treatment resulting in the 3.5-fold cisplatin-resistant subclone HCC38CisR and the 2.1-fold more resistant MDA-MB231CisR. Activation of pro-survival pathways was explored by immunostaining of phospho-receptor tyrosine kinases. Targeted therapies (NVP-AEW541, lapatinib and NVP-BEZ235) against activated pathways were investigated regarding cancer cell growth and cisplatin sensitivity. Results In HCC38CisR and MDA-MB231CisR, phosphorylation of epidermal growth factor receptor (EGFR) and insulin-like growth factor 1 receptor (IGF1R) was observed. In HCC38CisR, treatment with NVP-AEW541 increased potency of lapatinib almost seven-fold, but both compounds could not restore cisplatin sensitivity. However, the dual phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitor NVP-BEZ235 acted synergistically with cisplatin in HCC38CisR and fully restored cisplatin sensitivity. Similarly, NVP-BEZ235 increased cisplatin potency in MDA-MB231CisR. Furthermore, NVP-AEW541 in combination with lapatinib restored cisplatin sensitivity in MDA-MB231CisR. Conclusion Simultaneous inhibition of EGFR and IGF1R in cisplatin-resistant TNBC cell lines was synergistic regarding inhibition of proliferation and induction of apoptosis. Co-treatment with NVP-BEZ235 or with a combination of NVP-AEW541 and lapatinib restored cisplatin sensitivity and may constitute a targeted treatment option for cisplatin-resistant TNBC. Electronic supplementary material The online version of this article (10.1186/s12885-017-3695-5) contains supplementary material, which is available to authorized users.

Platinum plays a central role in the therapy of ovarian cancer, and the emergence of platinum resistance is a major obstacle for clinical management of the disease. We treated A2780 ovarian cancer cells by weekly cycles of cisplatin over a period of 6 months and unveiled that enhanced insulin-like growth factor I receptor (IGF-IR) expression and autocrine IGF-I are associated with hyperactivation of the IGF-IR and phosphatidylinositol-3-OH kinase (PI3K) pathways in cisplatin-resistant cells. IGF-IR expression levels increased during treatment cycles and correlated with cisplatin resistance. Purified IGF-I induced cisplatin resistance in diverse ovarian cancer cell lines, and small molecule inhibitors proved that IGF-IR and PI3K are essential for cisplatin resistance. Similar results were obtained with BG-1 ovarian cancer cells. Cytogenetic and array comparative genomic hybridization analyses revealed selection and de novo formation of chromosomal alterations during resistance development. An analysis of gene expression profiles of primary ovarian carcinomas identified the regulatory subunit PIK3R2 of PI3-kinase as a significant negative prognosis factor for ovarian cancer. We conclude that targeting the IGF-IR and the PI3K pathways is a promising new strategy to treat cisplatin-resistant ovarian carcinomas. [Cancer Res 2009;69(7):2996–3003]

Head and neck cancers are treated by a combination of surgery, radiotherapy and/or chemotherapy. The clinical success of cisplatin-based chemotherapy, mostly in combination with 5-FU or a taxane, is however limited by multifactorial intrinsic or acquired resistance. So far, known genes involved in cisplatin resistance do not sufficiently allow the prediction of cancer chemosensitivity. Thus, the purpose of this study was to search for further genes involved in cisplatin resistance by differential gene expression analysis of the parental tongue cancer cell line Cal27 and its 10-fold more resistant sub-cell line Cal27cis, which was obtained by treating Cal27 with increasing concentrations of cisplatin. As found by the suppression subtractive hybridization, expression of DKK1, an inhibitor of canonical WNT signaling, was decreased in Cal27cis. Microarray analysis, qPCR and ELISA confirmed the approximately 2-fold difference in expression. Cisplatin treatment and serum starvation increased by 2-fold the secretion of DKK1 in Cal27 and Cal27cis, thus rendering DKK1-levels significantly different in both cell lines under basal and stress conditions. Recombinant overexpression of DKK1 in Cal27 and Cal27cis resulted in clonal cell lines, which were both 2.2- to 3-fold more sensitive toward cisplatin in cell viability (MTT) and in proliferation (BrdU) assays. In conclusion, acquired (10-fold) resistance of Cal27 against cisplatin is associated with decreased DKK1 expression and could partially be reversed by DKK1 overexpression, thus suggesting DKK1 and the WNT signaling pathway as a marker and target for cisplatin chemosensitivity.

The dimeric anthracene derivative torrubiellin B ( 1 ) was isolated from the endophytic fungus Acremonium sp. that had been obtained from leaves of the Mangrove plant Sonneratia caseolaris . The absolute configuration of 1 was established as (5′ R ,10′ S ,10a′ R ) for the first time on the basis of its electronic circular dichroism (ECD) spectra aided with TDDFT-ECD calculations. Torrubiellin B ( 1 ) exhibited strong anti-tumor activity when tested in vitro against several solid cancer cell lines including cells that are resistant against the widely used cytostatic drug cisplatin. The IC 50 values of 1 against cisplatin sensitive and cisplatin resistant cells were in the range of 0.2–2.6 μM depending on cell line investigated.

Chemical investigation of the mycelial extract of a mixed culture of two marine alga-derived fungal strains of the genus Aspergillus has yielded one new cyclotripeptide, psychrophilin E (1), the recently reported oxepin-containing alkaloids, protuboxepin A (2) and oxepinamide E (3), together with three other polyketide derivatives (4–6). The chemical structure and relative and absolute configurations of psychrophilin E (1) were unambiguously established based on HRMS, 1D, 2D NMR and chiral-phase HPLC analysis of its hydrolysate. All the isolated compounds were assessed for their anti-proliferative activity against four different human cancer cell lines and some of them revealed selective activities.

Four tetrahydroxanthone dimers (1-4) and four biogenetically related monomers (5-8), including the new derivatives 4-6, were isolated from the endophyte Phomopsis longicolla. The absolute configurations of 2-4 were established for the first time by TDDFT electronic circular dichroism calculations, and that of phomoxanthone A (1) was revised by X-ray crystallography. Phomoxanthone A (1) showed the strongest pro-apoptotic activity when tested against a panel of human cancer cell lines, including cisplatin-resistant cells, whereas it was up to 100-fold less active against healthy blood cells. It was also the most potent activator of murine T lymphocytes, NK cells, and macrophages, suggesting an activation of the immune system in parallel to its pro-apoptotic activity. This dual effect in combating cancer cells could help in fighting resistance during chemotherapy. Preliminary structure-activity studies of isolated compounds and derivatives obtained by semisynthesis (9a-11) hinted at the location of the biaryl axis and the presence of acetyl groups as important structural elements for the biological activity of the studied tetrahydroxanthones.

Growing evidence supports the hypothesis that narcolepsy with cataplexy is an autoimmune disease. We here report genome-wide association analyses for narcolepsy with replication and fine mapping across three ethnic groups (3,406 individuals of European ancestry, 2,414 Asians and 302 African Americans). We identify a SNP in the 3' untranslated region of P2RY11, the purinergic receptor subtype P2Y₁₁ gene, which is associated with narcolepsy (rs2305795, combined P = 6.1 × 10⁻¹⁰, odds ratio = 1.28, 95% CI 1.19-1.39, n = 5689). The disease-associated allele is correlated with reduced expression of P2RY11 in CD8(+) T lymphocytes (339% reduced, P = 0.003) and natural killer (NK) cells (P = 0.031), but not in other peripheral blood mononuclear cell types. The low expression variant is also associated with reduced P2RY11-mediated resistance to ATP-induced cell death in T lymphocytes (P = 0.0007) and natural killer cells (P = 0.001). These results identify P2RY11 as an important regulator of immune-cell survival, with possible implications in narcolepsy and other autoimmune diseases.

The free fatty acid 1 receptor (FFA1 or GPR40), which is highly expressed on pancreatic β-cells and amplifies glucose-stimulated insulin secretion, has emerged as an attractive target for the treatment of type 2 diabetes. Several FFA1 agonists containing the para-substituted dihydrocinnamic acid moiety are known. We here present a structure-activity relationship study of this compound family suggesting that the central methyleneoxy linker is preferable for the smaller compounds, whereas the central methyleneamine linker gives higher potency to the larger compounds. The study resulted in the discovery of the potent and selective full FFA1 agonist TUG-469 (29).

Background Antipsychotics are divided into typical and atypical compounds based on clinical efficacy and side effects. The purpose of this study was to characterize in vitro a series of novel azecine-type compounds at human dopamine D1-D5 and 5HT2A receptors and to assign them to different classes according to their dopamine/5HT2A receptor profile. Results Regardless of using affinity data (pK i values at D1-D5 and 5HT2A) or selectivity data (15 log (Ki ratios)), principal component analysis with azecine-type compounds, haloperidol, and clozapine revealed three groups of dopamine/5HT2A ligands: 1) haloperidol; 2) clozapine plus four azecine-type compounds; 3) two hydroxylated dibenzazecines. Reducing the number of Ki ratios used for principal component analysis from 15 to two (the D1/D2 and D2/5HT2A Ki ratios) obtained the same three groups of compounds. The most potent dibenzazecine clustering in the same group as clozapine was the non-hydroxylated LE410 which shows a slightly different D2-like receptor profile (D2L > D3 > D4.4) than clozapine (D4.4 > D2L > D3). The monohydroxylated dibenzacezine LE404 clusters in a separate group from clozapine/LE410 and from haloperidol and shows increased D1 selectivity. Conclusion In conclusion, two compounds with a novel dopamine/5HT2A receptor profile, LE404 and LE410, with some differences in their respective D1/D2 receptor affinities including a validated pharmacophore-based 3D-QSAR model for D1 antagonists are presented.

Nat. Genet. 43, 66–71 (2011); published online 19 December 2010; corrected after print 22 September 2011 In the version of this article initially published, the percentage reduction of P2RY11 expression in CD8+ T lymphocytes was incorrectly given as 339%, when it should have been 72%. The percentagewas not given for NK cells and should have been 70%.

The reaction of the imidazolyl-4(5)-phosphane ligands 2-isopropylimidazol-4(5)yl-diphenylphosphane (4-MIP(iPr)) and tris(2-isopropylimidazol-4(5)yl)phosphane (4-TIP(iPr)) towards gold(I) has been explored and compared to those of analogous 1-methylimidazol-2-ylphosphane ligands. The structure of [(4-MIP(iPr))AuCl] () shows a linear P-Au-Cl coordination, whereas the 4-TIP(iPr) ligand forms a dinuclear complex [{(4-TIP(iPr))Au}(2)]Cl(2) (). Here, 4-TIP(iPr) bridges two gold(I) atoms in a head-to-tail P,N fashion. Complex forms in the presence of the hard Lewis acid ZnCl(2) the bimetallic complex [AuCl(4-TIP(iPr))ZnCl]Cl (), in which 4-TIP(iPr) bridges the two metal centers. In accordance with the HSAB concept the Au(I) atom is coordinated by the P atom and the zinc(II) by three N atoms in a N,N,N fashion. The solid-state structures of the complexes have been elucidated by single-crystal X-ray analysis. The Au(I)-Au(I) contact in is 2.8821(15) A. The biological activities of all imidazol-2-yl- and imidazol-4(5)-ylphosphane gold(I) complexes towards nine human cancer cell lines including seven ovarian cancer cell lines of different sensitivity towards cisplatin and two leukemia cell lines have been explored.