Browsing Over 173 Presentations
Panel discussion
7IN - Targeting histone H3K36me3-deficient cancers
- Timothy Humphrey (Oxford, GB)
- Timothy Humphrey (Oxford, GB)
Abstract
Background
SETD2-dependent histone H3 lysine 36 trimethylation (H3K36me3) plays a central role in both maintaining genome stability and in suppressing tumorigenesis, and is frequently depleted in particular cancer types. We find this histone mark plays an important role in promoting homologous recombination (HR) repair of DNA double-strand breaks. Further, H3K36me3 also performs an essential role in facilitating DNA replication following WEE1 kinase inhibition, through promoting efficient deoxyribonucleotide synthesis. Accordingly, H3K36me3-deficient cancers can be specifically targeted using the WEE1 inhibitor, AZD1775, resulting in replicative catastrophe and cell death. The use of AZD1775 to target H3K36me3-deficient cancers is now in clinical trials. Mechanistic insights into the targeting of H3K36me3-deficient cancers with AZD1775 and its implications will be presented.
Legal entity responsible for the study
CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
Disclosure
The author has declared no conflicts of interest.
Funding
Medical Research Council; Cancer Research UK; Clarendon Scholarship; Swiss National Science Foundation
22IN - Overview: Multiple ways to harness targeting DNA to treat cancer
- Ruth Plummer (Newcastle upon Tyne, GB)
- Ruth Plummer (Newcastle upon Tyne, GB)
60P - Investigating the role of nuclear sphingosine kinase 1 (SphK1) in lung cancer
- Fabiana Napolitano (Napoli, IT)
- Fabiana Napolitano (Napoli, IT)
- Roberta Rosa (Napoli, IT)
- Valentina D'Amato (Napoli, IT)
- Roberta C. Orsini (Napoli, IT)
- Paola Ciciola (Napoli, IT)
- Concetta Di Mauro (Napoli, IT)
- Antonio Santaniello (Napoli, IT)
- Roberta Marciano (Napoli, IT)
- Sabino De Placido (Napoli, IT)
- Roberto Bianco (Napoli, IT)
Abstract
Background
Sphingosine kinases (SphKs) are enzymes catalyzing the formation of a bioactive lipid messenger, sphingosine-1-phosphate (S1P) through phosphorylation of sphingosine. So far, two isoforms of SphK have been described: SphK1, which has cytosolic distribution, and SphK2, known to locate predominantly in the nucleus. Overactivation of SphKs is involved in tumor growth and progression through regulation of cell proliferation and apoptosis.
Methods
We studied the expression, the intracellular localization and the activity of SphK1 and SphK2 in non-small cell lung cancer (NSCLC) cell lines and in cancer patients.
Results
In NSCLC cells, Sphk1 was found in the cytosol, while Sphk2 showed a nuclear localization. Surprisingly, we observed SphK1 expression also in the nuclear compartment. In several of the tested cell lines, the expression of SphK1 was even higher in the nucleus compared to the cytosol. Consistently, in a NSCLC tissue microarray, SphK1 nuclear expression was detected in a wide number of samples. Based on these data, we hypothesize the presence of a nuclear import signal in the SphK1 sequence, probably recognized by Karyopherin beta2. We found, in the aminoacidic sequence of SphK1, a R/K/H-X(5)-P-Y C-terminal motif within a structurally disordered and positively charged regions of about 30 amino acids. In order to dissect the role of nuclear SphK1, we used different tools able to modulate nuclear import/export. Moreover, specific inhibitors of SphKs were tested. Among them, fingolimod (FTY720), an oral drug initially defined as a S1P receptors antagonist but also acting as a SphK1 inhibitor, is effective in NSCLC cell lines: a reduction of cell density of about 50% is obtained with a drug concentration of about 2.5 µM. Interestingly, fingolimod seems to be more effective in cells with a nuclear/cytosolic ratio of SphK1 expression > 1.
Conclusions
We demonstrate for the first time that SphK1 has a nuclear localization in NSCLC and we are now investigating its biological role in this context. Moreover, we propose nuclear SphK1 as a novel druggable target in human NSCLC cells. Since fingolimod is a clinically available drug, our results may suggest SphK1 targeting as a therapeutic opportunity to be tested in NSCLC patients.
Legal entity responsible for the study
Prof. Roberto Bianco
Funding
Has not received any funding
Disclosure
All authors have declared no conflicts of interest.
92P - Targeting PI3K-AKT pathway in Gemcitabine Resistant Pancreatic Duct Adenocarcinoma
- Ouyang Ge (Nanjing, CN)
- Ouyang Ge (Nanjing, CN)
- Jiangning Gu (Shanghai, CN)
- Youwei Zhu (Shanghai, CN)
- Jiaqiang Zhang (Shanghai, CN)
- Raymond Monk (Berlin, DE)
- Lutz Schomburg (Berlin, DE)
Abstract
Background
Pancreatic cancer is the fourth leading cause of cancer death, with an overall 5-year survival rate of <10%. These statistics have not changed in almost 50 years. Chemotherapy-resistance is a major barrier for successful therapy of pancreatic duct adeno carcinoma (PDAC). Resistance may arise de novo or is acquired upon intensified chemotherapeutic regimens. Hence, a better characterization of the underlying mechanisms and the identification of new drug targets are a therapeutic necessity.
Methods
Primary pancreatic cancer cells were isolated from CKP (Ptf1a+/Cre, Kras+/LSL-G12D, P53loxP/loxP) mouse and cultured with increasing concentrations of gemcitabine to induce gemcitabine-resistant cell lines. The resistance status was determined by dose-response experiments, calculating the half maximal inhibitory concentration (IC50) of gemcitabine using cell titer assays. Alterations in the Pi3k-akt pathway were identified by genome-wide analyses and verified by Western blot.
Results
Our data indicate that the pi3k-akt pathway is over-activated in gemcitabine-resistant cells. Accordingly, the gemcitabine-resistant cells were more sensitive to pi3k inhibitors than gemcitabine-naïve cells cultured in parallel. Besides the pi3k pathway, several key genes controlling energy metabolism and proliferation were also significantly altered in the gemcitabine-resistant cells as compared with controls.
Conclusions
Gemcitabine treatment might have unwanted side effects by triggering the pi3k-akt pathway in treatment-induced resistance. In order to prevent or overcome this development, a parallel application of pi3k-akt inhibitors along or subsequent to gemcitabine plus abraxane may constitute a meaningful adjuvant treatment strategy. This hypothesis needs to be tested in further detail.
124P - Detection of KRAS mutation, MSI and TP53 status in Indonesian CRC patients with its association to PD-L1 expression
- Gita D. Kusumo (east jakarta, ID)
- Gita D. Kusumo (east jakarta, ID)
- Teguh P. Putra (east jakarta, ID)
- Akterono D. Budiyati (east jakarta, ID)
- Fritzie Rexana (Jakarta, ID)
- Aru Sudoyo (Jakarta, ID)
- Antonius N. Kurniawan (Jakarta, ID)
- Ahmad R. Utomo (east jakarta, ID)
- Andi Utama (east jakarta, ID)
Abstract
Background
KRAS and microsatellite instability (MSI) status are well established markers in personalized therapy of colorectal cancer (CRC). The immune checkpoint inhibitor Programmed Death 1 (PD1) and its ligand (PD-L1) have been reported in recent studies as promising targets for cancer therapy. However, there is still a debatable result in the correlation between PD1/PD-L1 expression and KRAS and MSI status as the essential CRC biomarker. Therefore, this study aims to characterize molecular profiles of KRAS, MSI, and TP53 in their association with PD-L1 expression in an Indonesian CRC patient cohort.
Methods
We screened formalin-fixed paraffin-embedded (FFPE) samples from 88 CRC patients for three biomarkers (KRAS, TP53 and PD-L1) and their MSI status. MSI status was defined by the MMR protein expression (MSH2, MLH1, PMS2, MSH6) using monoclonal antibodies by immunohistochemistry (IHC) methods. IHC was also used to detect PD-L1 and TP53 protein expression. High resolution melting PCR along with Sanger sequencing were carried out to detect KRAS mutation status. All the data was statistically analyzed using Fischer exact test.
Results
Only 12.6% (16 out of 88) of sample showed PD-L1 expression. Statistical analysis showed the association between MSI with PD-L1 expression (p = 0.0001). The study showed no association between PD-L1 expression with TP53 (p = 0.9164) and KRAS status (p = 0.3749). Despite that, PD-L1 expression still tended to be higher in patients with wild type KRAS (82.3%/17.7%; wt/mut) and TP53 (62.5%/37.5%; wt/mut).
Conclusions
PD-L1 expression was associated with patient MSI status in this Indonesian cohort. Defining a patient’s MSI status could be suggested as an important step in a screening process for CRC treatment while using anti PD1/PD-L1 targeted therapy.
Legal entity responsible for the study
Institutional Review Board, Stem Cell and Cancer Institute, Jakarta
Funding
PT. Kalbe Farma Tbk., Jakarta, Indonesia
Disclosure
All authors have declared no conflicts of interest.
18IN - Glioma and IDH targeting
- Daniel Cahill (Boston, US)
- Daniel Cahill (Boston, US)
Abstract
Background
Approximately 80% of WHO grade II and III gliomas, and secondary glioblastomas (representing 25% of adult diffuse gliomas overall) harbor mutations in the metabolic isocitrate dehydrogenase enzymes encoded by the IDH1/2 genes. These mutations, now recognized as the genetic hallmark of these cancers, result in neomorphic enzymatic activity driving overproduction of the oncometabolite 2-hydroxyglutarate (2-HG), which leads to profound reprogramming of tumor cellular metabolism. As a result, IDH1-mutant gliomas are dependent upon the canonical coenzyme NAD+ for survival. It is known that poly(ADP-ribose) polymerase (PARP) activation consumes NAD+ during base excision repair of chemotherapy-induced DNA damage. We therefore hypothesized that a strategy combining NAD+ biosynthesis inhibitors with the alkylating chemotherapeutic agent temozolomide could potentiate NAD+ depletion-mediated cytotoxicity in mutant IDH1 cancer cells.
Methods
We used several IDH mutant cancer models to study NAD+ metabolism. To investigate the impact of temozolomide (TMZ) on NAD+ metabolism, patient-derived xenografts and engineered mutant IDH1-expressing cell lines were exposed to TMZ, in vitro and in vivo, both alone and in combination with nicotinamide phosphoribosyltransferase (NAMPT) inhibitors, which block NAD+ biosynthesis.
Results
We found that TMZ is an NAD+ stressor, specifically in IDH1 mutant cancers. Mechanistically, TMZ stimulates NAD+ consumption by PARP via activation of DNA damage repair in exposed cells. The acute time period (<3 hours) after TMZ treatment displayed a burst of NAD+ consumption driven by PARP activation, but the dynamic capacity of the base excision repair system typically is able to withstand the metabolic stress induced by these DNA repair processing demands. However, in IDH1-mutant-expressing cells, this consumption of NAD+ critically reduced the abnormally lowered basal steady-state levels of NAD+, introducing a window of hypervulnerability to NAD+ biosynthesis inhibitors. This effect was selective for IDH1-mutant cells and independent of methylguanine methyltransferase or mismatch repair status, which are known rate-limiting mediators of adjuvant temozolomide genotoxic sensitivity. Combined temozolomide and NAMPT inhibition in an in vivo IDH1-mutant cancer model exhibited enhanced efficacy compared with each agent alone.
Conclusions
In conclusion, we find that IDH1-mutant cancers have distinct metabolic stress responses to chemotherapy-induced DNA damage and that combination regimens targeting nonredundant NAD+ pathways yield potent anticancer efficacy in vivo. More generally, our results suggest that effective targeting of convergent metabolic pathways in genetically selected cancers could minimize treatment toxicity and improve durability of response to therapy. Highlighting the central importance of NAD+ levels in IDH mutant gliomas, our observations suggests that metabolic strategies targeting NAD+ homeostasis may be combined with standard-of-care therapies to improve efficacy against these tumors.
Legal entity responsible for the study
Harvard-Massachusetts General Hospital
Disclosure
D. Cahill: Consulting: Merck, Lilly.
Funding
NIH, Burroughs Wellcome Foundation
55P - Protein expression and clinical significance of the NEDDylation pathway in myelodysplastic syndrome
- Fatemeh Majidi (Düsseldorf, DE)
- Fatemeh Majidi (Düsseldorf, DE)
- Judith Strapatsas (Düsseldorf, DE)
- Simon K. Brille (Düsseldorf, DE)
- Iris Fey (Düsseldorf, DE)
- Frank Neumann (Cambridge, US)
- Allison Berger (Cambridge, US)
- Ulrich Germing (Düsseldorf, DE)
- Rainer Haas (Düsseldorf, DE)
- Norbert Gattermann (Düsseldorf, DE)
Abstract
Background
A phase I clinical trial of Pevonedistat (MLN4924), a NEDD8-activating enzyme inhibitor, in AML and MDS showed modest clinical activity as a single agent. A phase II trial with Pevonedistat plus Azacytidine versus single-agent Aza is ongoing. As yet, there is no data regarding activity or dysfunction of the NEDDylation pathway in MDS. We examined NEDDylation pathway protein expression and its prognostic relevance in MDS.
Methods
On a tissue microarray (TMA) with bone marrow biopsies from 119 MDS patients, 40 AML pts, and 11 normal controls, we established immunohistochemistry (IHC) for NEDD8, NAE1 and UBE2M. Semi-quantitative analysis was done according to Remmele-Stegner immunoreactive score (IRS) (0 to 12 points). Clinical follow-up was available for 116 pts.
Results
Of 96 evaluable MDS pts, 46 (39.7%) showed an abnormal karyotype. Ten patients who received disease-modifying treatment prior to biopsy were excluded from survival analysis. On IHC, 100% of 40 AMLs and 11 normal controls were clearly positive (IRS>4) for all three NEDDylation pathway proteins. MDS patients showed a different pattern. While NEDD 8 was positive in the majority (60.6%), NAE1 and UBE2M were expressed in only 30.8% and 29.4%, respectively. For each protein, expression was not correlated with MDS type (WHO 2016), IPSS-R risk group, overall survival or AML transformation. Patients with strong expression of all three proteins survived longer (51 vs. 26 months), but the difference did not reach statistical significance (p = 0.10). Low expression of NAE1 and UBE2M significantly correlated with the presence of karyotype anomalies (p = 0.01 and p = 0.02, respectively).
Conclusions
In contrast to AML, expression of NEDD8 conjugation pathway proteins was low in a substantial proportion of MDS patients. The significant association between low or absent expression of NAE1 and UBE2M, and the presence of karyotype anomalies, suggests that low NEDDylation pathway activity may contribute to chromosomal instability. Nevertheless, since NEDD8 increases DNMT3b-dependent DNA methylation, NEDDylation pathway inhibition may be useful to augment treatment with hypomethylating drugs or counteract resistance to this therapy.
Legal entity responsible for the study
Universitätsklinikum Düsseldorf
Funding
Takeda Pharmaceutical Company
Disclosure
F. Majidi, N. Gattermann: The current research project is funded by Takeda Pharmaceutical Company. All other authors have declared no conflicts of interest.
87P - Towards the identification of the mechanism of action of antitumor 1-methyl-D-tryptophan
- Maria Teresa O. Pallotta (Perugia, IT)
- Maria Teresa O. Pallotta (Perugia, IT)
- Alberta Iacono (Perugia, IT)
- Elisa Albini (Perugia, IT)
- Ciriana Orabona (Perugia, IT)
- Maria laura Belladonna (Perugia, IT)
- Roberta Bianchi (Perugia, IT)
- Alice Coletti (Perugia, IT)
- Francesco Greco (Perugia, IT)
- Antonio Macchiarulo (Perugia, IT)
- Ursula Grohmann (Perugia, IT)
Abstract
Background
In recent years, tryptophan degradation has received increasing attention as a potent immunosuppressive mechanism involved in the maintenance of immunological tolerance in both tumor draining lymph nodes and tumors. Indoleamine 2,3-dioxygenase 1 (IDO1) is a tryptophan metabolizing enzyme and its mechanisms of action as an immune regulator involves tryptophan deprivation, production of immunosuppressive metabolites (kynurenines), and activation of signaling events through binding of tyrosine phosphatases (SHPs). IDO1 is chronically activated in many cancer patients and its expression and enzyme activity correlate with a poor prognosis in patients with various cancers. In the past, IDO1 inhibition was mostly achieved using the racemic mixture of 1-D,L-methyltryptophan (1-MT). As it became apparent that IDO1 inhibition may be a promising target for cancer therapy, the individual stereoisomers of 1-MT were investigated in more details. 1-L-MT was shown to more effectively inhibit IDO1 in enzyme assays and in cancer cell lines. However, 1-D-MT showed superior anti-tumor activity in mouse models and was therefore chosen for clinical trials. 1-D-MT is currently being tested in phase II clinical trials (indoximod) as an adjunct to conventional chemotherapy, although its immunostimulatory mechanism is still unknown. We here investigated whether 1-D-MT could interfere with IDO1 signaling rather than catalytic activity.
Methods
The enzymatic activity of IDO1 was measured in vitro in terms of the ability of both purified protein or stably transfected cells to metabolize tryptophan to kynurenine. In these cells we also evaluated IDO1 protein turnover and its ability to bind SHPs through both FRET analysis and immunoprecipitation.
Results
1-D-MT did not inhibit IDO1 catalytic activity, but affected IDO1-SHPs binding.
Conclusions
Our data indicated that 1-D-MT anticancer activity may rely on the inhibition of IDO1 signaling but not catalytic activity.
Legal entity responsible for the study
University of Perugia
Funding
This work was supported by the European Research Council (338954- DIDO to U. Grohmann).
Disclosure
All authors have declared no conflicts of interest.
119P - Adjuvant radiation therapy effects systemic immune response cells in female breast cancer patients
- Nongnit Lewin (Jönköping, SE)
- Nongnit Lewin (Jönköping, SE)
Abstract
Background
Radiation induces DNA damage, leads to cell cycle arrest and cell death. We investigated the effect of adjuvant radiation therapy (RT) on systemic innate and adaptive immune cells in female breast cancer (BC) patients by assessing circulating white blood cells (WBCs) and its subpopulations.
Methods
Peripheral blood cell numbers from BC patients (n = 114, median age 64) who received adjuvant RT (50 Gy) at Dept. Oncology, Ryhov hospital, Sweden, were analyzed. Blood (30 ml) was obtained from BC patients before and after adjuvant RT. The number of total WBCs and its subpopulations were analyzed by Sysmex XE5000 instrument. The phenotype of ex vivo fresh peripheral white blood cell subpopulation were analyzed by BD FACSCanto II flow cytometer and BDFACSDiva software program. Paired T-test was used for comparison between the patients before and after adjuvant RT, Significant p-values <0.05.
Results
1. After adjuvant RT, the number of WBCs, neutrophils and lymphocytes were significantly decreased 2. Neutrophil to lymphocyte ratio (NLR) is suggested to be a biomarker for poor prognostic and short survival time for cancer patient. Interestingly, the NLR was significantly increased after treatment, p-values = <0.001. 3. As for total lymphocytes, adjuvant RT decreased the numbers in all T-cell subpopulations studied (CD3+, CD4+, CD8+, and CD3 + 56 + [NKT cells]) and in CD56 + (NK cells).
Conclusions
Our results indicated that adjuvant RT of BC patients induces systemic alterations in number of innate and adaptive immune cells. This might be due to the bystander or distant immunosuppression from adjuvant radiation. Alternative, adaptive and innate immune response cells are redistributed from circulation to the radiation site. The significance of these alteration on clinical outcome need further investigation.
Legal entity responsible for the study
Regional Ethical Review Board of Linköping
Funding
Clinical Cancer Research in Jönköping and Futurum, Ryhov Hospital, Jönkoping Sweden
Disclosure
All authors have declared no conflicts of interest.
50O - A first-in-human first-in-class (FIC) trial of the monocarboxylate transporter 1 (MCT1) inhibitor AZD3965 in patients with advanced solid tumours
- Ruth Plummer (Newcastle upon Tyne, GB)
- Ruth Plummer (Newcastle upon Tyne, GB)
- Sarah Halford (London, GB)
- Paul Jones (London, GB)
- Steve Wedge (Newcastle upon Tyne, GB)
- Sandra Hirschberg (London, GB)
- Gareth Veal (Newcastleupon Tyne, GB)
- Geoffrey Payne (London, GB)
- Maxine Chenard-Poirier (London, GB)
- Hector Keun (London, GB)
- Udai Banerji (Sutton, GB)
Abstract
Background
A key metabolic alteration in tumour cells is increased dependency on glycolysis, resulting in the production of lactate which is transported out of cells by MCTs. Inhibition of MCT-1 can constrain cancer cell growth in preclinical models. We report results on the phase I study of AZD3965, a FIC inhibitor of MCT-1.
Methods
Patients with advanced solid tumours were treated with oral (po) AZD3965 at total daily doses of 5-30mg given once (od) and twice daily (bd). Exclusion criteria included a history of retinal or cardiac disease due to preclinical toxicology findings in the eye and heart (which express MCT-1). The primary objectives were to determine the safety, dose limiting toxicities (DLT) and maximum tolerated dose (MTD) of AZD3965. Intensive pharmacokinetic (PK) profiling was performed with subsequent modelling for receptor occupancy. Pharmacodynamic profiling included imaging to detect pH changes and tumour glucose uptake, and plasma/urine metabolomics.
Results
40 patients (24M:16F; median age 64.5 were treated at dose levels of 5, 10, 20, and 30mg od and 10 and 15mg bd. AZD3965 was well tolerated with nausea and fatigue (CTCAE Gr1-2) the most commonly reported side effects. A single DLT of cardiac troponin rise was observed at 20mg od. Asymptomatic, reversible retinal ERG changes were first observed at 20mg od, with DLTs observed at doses above 20mg od. PK data indicate exposures in the preclinical efficacy range. Metabolomic changes in urinary lactate and ketones correlate with on-target activity. A patient with undiagnosed tumour-associated lactic acidosis experienced a DLT with exacerbation of this following a single 10mg dose of AZD3965, again indicating target engagement.
Conclusions
The MCT1 inhibitor AZD3965 can be administered to patients at doses which engage the drug target, with a RP2D of 10mg bd po. Observed DLTs were primarily dose dependent, asymptomatic, reversible changes in retinal function, an expected on-target effect. Part 2 of the study is open to recruitment in patients with diffuse large B cell lymphoma, a tumour that predominantly expresses MCT1.
Legal entity responsible for the study
Cancer Research UK
Funding
Cancer Research UK
Disclosure
All authors have declared no conflicts of interest.
TAT 2018 Scientific Welcome address
- Giuseppe Giaccone (Washington DC, US)
- Giuseppe Giaccone (Washington DC, US)