ALBERT

Beschreibung: Background: Receptor tyrosine kinase (RTK) (ROR1) is normally expressed during embryogenesis but absent in most normal tissues. However, ROR1 is overexpressed in several cancers (onco-fetal RTK) and of importance for various tumor cell functions such as proliferation and survival. In patients with diffuse large B-cell lymphomas (DLBCL) there is a great medical need to develop new treatment alternatives for those not responding to primary treatment as well as for patients with relapse as effective treatments are warranted. Inhibition of ROR1 by a small molecule ROR1 inhibitor (KAN0439834) abrogated downstream kinase activities as well as induced apoptosis of various tumor cells as CLL and pancreatic carcinoma (Leukemia, Oct;32(10):2291-2295, 2018) (PLoS One. 13(6): e0198038, 2018). A 2nd generation of ROR1 inhibitor (KAN0441571C) has been synthesized with the aim to bind to the ROR1-TK domain and inhibit ROR1 signaling. Aim: To examine the expression of ROR1 in DLBCL cell lines (RC-KB, SUDHL4, MS, OCL-LY3, U2932) and in patients´ samples at different stages of DLBCL as well as effects of KAN0441571C on survival of DLBCL cells and ROR1 signaling. Methods: Flow cytometry, tissue microarray and immunohistochemistry assays were used to check ROR1 expression. MTT and Annexin V/PI assays were applied to analyse cytotoxicity and apoptosis of KAN0441571C alone or in combination with ibrutinib (BTK inhibitor) and venetoclax (BCL-2 inhibitor) on DLBCL cell lines. Western blot was performed to evaluate ROR1 phosphorylation and associated signaling pathways. DLBCL cells were also cultured with HS-5 stromal cells (ROR1 neg.) to evaluate the apoptosis inhibitory effects of stromal cells. Results: ROR1 expression was significantly more frequently noted in patients with advanced disease (Richter´s, transformation, transformed follicular lymphoma and refractory DLBCL) compared to less advanced disease (recurrent or de novo DLBCL) (p=0.0001). In primary refractory and relapsing DLBCL 5-years survival was 45% in ROR1- patients (n=17) while in ROR1+ patients (n=16) the corresponding figure was 10000 nM). EC50 for venetoclax in the ROR1+ DLBCL cell lines varied between 100 and 500 and 5000 - 10000 nM for ibrutinib. In comparison to venetoclax, KAN0441571C induced a similar or significantly higher cytotoxic effect. KAN0441571C and venetoclax seemed to be the most promising drug combination approaching 100% killing at the EC50 dose for each drug. Apoptosis was confirmed by Annexin V/PI staining as well as by downregulation of BCL-2 and MCL-1 as well as cleavage of PARP and caspase 3. KAN0441571C dephosphorylated ROR1 as well as the co-receptor LRP6 and the SRC protein which binds to phosphorylated ROR1. The downstream molecules PI3Kδ/AKT/mTOR was also dephosphorylated and the transcription factor CREB. CK1δ and GSK3B were also dephosphorylated and β-catenin downregulated indicating involvement of both the non-canonical and canonical Wnt pathways. When DLBCL and HS-5 cells (ROR1 neg.) were co-cultured, HS-5 cells could partially prevent induction of apoptosis of DLBCL cells at low concentrations of KAN0441571C, while at higher concentrations the presence of stromal cells was less effective. Zebrafish embryos transplanted with the OCI-Ly3 cell line were treated for 3 days with KAN0441571C (25-1000 nM). No toxic effects of the drug could be noted. A significant dose and time-dependent decrease in the tumor area were noted. Conclusion: KAN0441571C is the 2nd generation of a novel class of ROR1-inhibiting small molecule drugs. The molecule was more effective in inducing apoptosis of DCBCL cells than venetoclax or ibrutinib. New anti-cancer drugs with other mechanisms of action than those clinically available for DLBCL are warranted to improve the prognosis. ROR1 inhibitors in combination with other targeted drugs as venetoclax and ibrutinib might improve the therapeutic effects. KAN0441571C may be a novel drug candidate which needs further exploration in DLBCL. Disclosures Lehto: Kancera AB: Employment. Vågberg:Kancera AB: Employment. Olsson:Kancera AB: Employment. Löfberg:Kancera AB: Employment. Norström:Kancera AB: Employment. Schultz:Kancera AB: Employment, Equity Ownership. Norin:Kancera AB: Employment. Olin:Kancera AB: Employment, Equity Ownership. Österborg:Kancera AB: Research Funding; Janssen: Research Funding; Abbvie: Research Funding; Gilead: Research Funding; BeiGene: Research Funding. Mellstedt:Kancera AB: Consultancy, Equity Ownership, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Beschreibung: Background: ROR1 - a receptor tyrosine kinase (RTK) - is essential for normal embryonic development, but is absent on most normal adult tissues. ROR1 is of importance of cell proliferation, differentiation, survival and metabolism. However, ROR1 is overexpressed in several types of cancer (onco-fetal RTK). MCL is an aggressive and incurable non-Hodgkin lymphoma characterized by translocation (11;14) (q13;q32) and cyclin D overexpression. ROR1 has been described to be highly expressed in MCL cells. We have previously presented results on a small molecule ROR1 inhibitor in CLL (KAN0439834) (Leukemia 32(10):2291, 2018). A second generation ROR1 inhibitor, KAN0441571C, has been developed with improved killing of tumor cells and with longer half-life time (〉10h) (PK studies in mice/rats/dogs) compared to KAN0439834. Aim: In this study we examined effects of the ROR1 small molecule inhibitor KAN0441571C in human MCL cells (Granta-519, Jeko-1, JVM-2, Z138, Mino) as part of a pre-clinical evaluation. Methods: ROR1 expression was evaluated by flow cytometry and WB. Cytotoxicity was analysed by MTT and apoptosis by Annexin V/P staining and Western Blot for apoptotic proteins. Cytotoxicity (MTT) was also analysed by combining the ROR1 inhibitor with ibrutinib, acalabrutinib, venetoclax and bendamustine. Effects of KAN0441571C on ROR1 inactivation (dephosphorylation) and signaling pathways were evaluated by WB. Results: All five cell-lines expressed phosphorylated ROR1 (130 kDa) with a varying intensity. Surface expression (flow-cytometry) varied from 0% (JVM-2) to 100% (Mino and JeKo-1). The data indicate expression of also splice variants lacking the extracellular domain. KAN0441571C induced time and dose dependent apoptosis of the five MCL cell-lines which was p53 independent. EC50 varied between 100-250 nM (24h). Apoptosis was confirmed by cleavage of caspase 3 and PARP as well as down-regulation of the MCL-1 and BCL-2 proteins. Moreover, ROR1 was dephosphorylated by KAN0441571C. Downstream of ROR1 both the Wnt canonical and non-canonical pathways were inactivated depending on the cell line. KAN0441571C had in most cell lines a similar cytotoxic effect as ibrutinib, acalabrutinib and venetoclax while bendamustine was inferior. KAN0441571C had an additive effect to ibrutinib, acalabrutinib and venetoclax respectively and KAN0441571C in combination with either of these three agents induced a complete killing of the cell lines. Conclusions: KAN0441571C is a second generation of a novel class of ROR1-tyrosine kinase inhibitor. This small molecule was effective in inducing apoptosis of MCL cells with other mechanisms of action than for drugs in clinical use for MCL. Combination of KAN0441571C with other MCL targeting drugs induced a complete killing of the tumor cell population in a preclinical in vitro model. Our results support the further development of ROR1 small molecule inhibitors as a new therapeutic principle in MCL as well as in other B-cell malignancies with an additive effect to existing targeted therapeutics. Disclosures Schultz: Kancera AB: Employment, Equity Ownership. Norin:Kancera AB: Employment. Olin:Kancera AB: Employment, Equity Ownership. Österborg:Janssen: Research Funding; Kancera AB: Research Funding; BeiGene: Research Funding; Abbvie: Research Funding; Gilead: Research Funding.

Beschreibung: Bulk-carbonate carbon isotope ratios are a widely applied proxy for investigating the ancient biogeochemical carbon cycle. Temporal carbon isotope trends serve as a prime stratigraphic tool, with the inherent assumption that bulk micritic carbonate rock is a faithful geochemical recorder of the isotopic composition of seawater dissolved inorganic carbon. However, bulk-carbonate rock is also prone to incorporate diagenetic signals. The aim of the present study is to disentangle primary trends from diagenetic signals in carbon isotope records which traverse the Permian–Triassic boundary in the marine carbonate-bearing sequences of Iran and South China. By pooling newly produced and published carbon isotope data, we confirm that a global first-order trend towards depleted values exists. However, a large amount of scatter is superimposed on this geochemical record. In addition, we observe a temporal trend in the amplitude of this residual δ13C variability, which is reproducible for the two studied regions. We suggest that (sub-)sea-floor microbial communities and their control on calcite nucleation and ambient porewater dissolved inorganic carbon δ13C pose a viable mechanism to induce bulk-rock δ13C variability. Numerical model calculations highlight that early diagenetic carbonate rock stabilization and linked carbon isotope alteration can be controlled by organic matter supply and subsequent microbial remineralization. A major biotic decline among Late Permian bottom-dwelling organisms facilitated a spatial increase in heterogeneous organic carbon accumulation. Combined with low marine sulfate, this resulted in varying degrees of carbon isotope overprinting. A simulated time series suggests that a 50 % increase in the spatial scatter of organic carbon relative to the average, in addition to an imposed increase in the likelihood of sampling cements formed by microbial calcite nucleation to 1 out of 10 samples, is sufficient to induce the observed signal of carbon isotope variability. These findings put constraints on the application of Permian–Triassic carbon isotope chemostratigraphy based on whole-rock samples, which appears less refined than classical biozonation dating schemes. On the other hand, this signal of increased carbon isotope variability concurrent with the largest mass extinction of the Phanerozoic may provide information about local carbon cycling mediated by spatially heterogeneous (sub-)sea-floor microbial communities under suppressed bioturbation.

Beschreibung: Bulk-carbonate carbon isotope measurements are a widely applied proxy for investigating the ancient biogeochemical carbon cycle. Temporal carbon isotope trends serve as a prime stratigraphic tool, with the inherent assumption that bulk micritic carbonate rock is a faithful geochemical recorder of the isotopic composition of seawater dissolved inorganic carbon. However, bulk-carbonate rock is also prone to incorporate diagenetic signals. The aim of the present study is to disentangle primary trends from diagenetic signals in carbon isotope records which traverse the Permian–Triassic boundary in marine carbonate-bearing sequences of Iran and South China. By pooling newly produced and published carbon isotope data we confirm that a global first-order trend towards depleted values exists. However, a large amount of scatter is superimposed on this geochemical record. In addition, we observe a temporal trend in the amplitude of this residual δ13C variability, which is reproducible for the two studied regions. We suggest that (sub)seafloor microbial communities and their control on calcite nucleation as well as on ambient porewater dissolved inorganic carbon-δ13C pose a viable mechanism to induce bulk-rock δ13C variability. Numerical model calculations highlight that early diagenetic carbonate rock stabilization, and linked carbon isotope alteration, can be controlled by organic matter supply and subsequent microbial remineralization. Low marine sulfate and a major biotic decline among late Permian bottom-dwelling organisms facilitated a spatial increase in heterogeneous organic carbon accumulation, causing varying degrees of carbon isotope overprint. A simulated time series suggests that a 50 % increase in the spatial scatter of organic carbon relative to the average, in addition to an imposed increase in the likelihood of sampling cements formed by microbial calcite nucleation to one out of 10 samples, is sufficient to induce the observed signal of carbon isotope variability. These findings put constraints on the application of Permian–Triassic carbon isotope chemostratigraphy based on whole-rock samples, which appears less refined than classical biozonation dating schemes. On the other hand, this signal of increased carbon isotope variability concurrent with the largest mass extinction of the Phanerozoic may inform about local carbon cycling mediated by spatially heterogeneous (sub)-seafloor microbial communities under suppressed bioturbation.

Beschreibung: The Permian–Triassic boundary sections in north-western Iran belong to the most complete successions, in which the largest mass extinction event in the history of the Earth can be studied. We investigated the Changhsingian stage in six sections in the area of Julfa (Aras Valley) for their lithology, conodonts and ammonoids. Revision of the biostratigraphy led to the separation of 10 conodont zones (from bottom to top Clarkina orientalis–C. subcarinata interval zone, C. subcarinata, C. changxingensis, C. bachmanni, C. nodosa, C. yini, C. abadehensis, C. hauschkei, Hindeodus praeparvus–H. changxingensis and Merrilina ultima–Stepanovites ?mostleri zones) and 8 ammonoid zones (from bottom to top Iranites transcaucasius–Phisonites triangulus, Dzhulfites nodosus, Shevyrevites shevyrevi, Paratirolites trapezoidalis, P. waageni, Stoyanowites dieneri, Abichites stoyanowi and Arasella minuta zones). The new ammonoid genera Stoyanowites and Arasella are described.

Beschreibung: The Permian–Triassic boundary section in the Aras Valley in NW Iran is investigated with respect to carbonate microfacies, biostratigraphy (particularly conodonts, nautiloids, and ammonoids), chemostratigraphy (carbon isotopes), and environmental setting. Correlation of the data allows the establishment of a high-resolution stratigraphy based on conodonts (with four Wuchiapingian, 10 Changhsingian, and three Griesbachian zones), ammonoids (with nine Changhsingian zones), and carbon isotopes; it forms the base for the reconstruction of the environmental changes before and after the end-Permian extinction event at the studied locality. In the Aras Valley section, there is no evidence for the development of anoxic conditions, associated with the end-Permian mass extinction.