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result(s) for
"Germing, Ulrich"
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Immunomodulatory drugs disrupt the cereblon–CD147–MCT1 axis to exert antitumor activity and teratogenicity
2016
Thalidomide and its derivatives lenalidomide and pomalidomide, which are used to treat multiple myeloma and del(5q) myelodysplastic syndrome, have antitumor and teratogenic effects through a mechanism involving destabilization of the CD147 and MCT1 proteins.
Immunomodulatory drugs (IMiDs), such as thalidomide and its derivatives lenalidomide and pomalidomide, are key treatment modalities for hematologic malignancies, particularly multiple myeloma (MM) and del(5q) myelodysplastic syndrome (MDS). Cereblon (CRBN), a substrate receptor of the CRL4 ubiquitin ligase complex, is the primary target by which IMiDs mediate anticancer and teratogenic effects. Here we identify a ubiquitin-independent physiological chaperone-like function of CRBN that promotes maturation of the basigin (BSG; also known as CD147) and solute carrier family 16 member 1 (SLC16A1; also known as MCT1) proteins. This process allows for the formation and activation of the CD147–MCT1 transmembrane complex, which promotes various biological functions, including angiogenesis, proliferation, invasion and lactate export. We found that IMiDs outcompete CRBN for binding to CD147 and MCT1, leading to destabilization of the CD147–MCT1 complex. Accordingly, IMiD-sensitive MM cells lose CD147 and MCT1 expression after being exposed to IMiDs, whereas IMiD-resistant cells retain their expression. Furthermore, del(5q) MDS cells have elevated CD147 expression, which is attenuated after IMiD treatment. Finally, we show that
BSG
(
CD147
) knockdown phenocopies the teratogenic effects of thalidomide exposure in zebrafish. These findings provide a common mechanistic framework to explain both the teratogenic and pleiotropic antitumor effects of IMiDs.
Journal Article
Wilm’s Tumor 1-guided preemptive treatment with hypomethylating agents for molecular relapse of AML and MDS after allogeneic transplantation
by
Haas, Rainer
,
Germing Ulrich
,
Pechtel Sabrina
in
Acute myeloid leukemia
,
Leukemia
,
Lymphocytes
2021
Hypomethylating agents (HMA) for relapsed acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) after allogeneic transplantation (allo-SCT) are most effective when used at the stage of molecular relapse. As Wilm’s Tumor 1 (WT1)- expression has proven to serve as broadly applicable, sensitive and specific minimal residual disease (MRD) marker, we measured WT1-expression in 35 AML and MDS patients using a standardized assay for the guidance of therapy with HMA and donor lymphocyte infusions (DLI). Molecular relapse was detected in median 168 days post-transplant prompting therapy with a median of six HMA cycles and at least one DLI (n = 22, 63%). Hereby, 13 patients (37%) achieved major response (=MRD− complete remission [CR]), and 7 patients (20%) achieved minor response (=MRD+ CR), whereas 15 patients (43%) progressed into hematologic relapse. Two-year overall survival (OS) rate was 35% including 11 patients (31%) with ongoing MRD− remission for a median of 21 months. Patients with the major response after six cycles had significantly better OS suggesting that those not achieving MRD negativity after six cycles are candidates for alternative therapies. Combining MRD-monitoring of WT1-expression and preemptive therapy with HMA and DLI appears as a practicable and efficient approach for imminent relapse after allo-SCT.
Journal Article
The role of genetic testing in accurate diagnosis of X-linked sideroblastic anemia: novel ALAS2 mutations and the impact of X-chromosome inactivation
by
Gattermann, Norbert
,
Olivella, Mireia
,
Ferrer-Cortés, Xènia
in
5-Aminolevulinate synthase
,
5-Aminolevulinate Synthetase - chemistry
,
5-Aminolevulinate Synthetase - genetics
2025
X-linked sideroblastic anemia (XLSA) is a hereditary disorder affecting heme biosynthesis, caused by mutations in the
ALAS2
gene, which encodes the erythroid-specific enzyme 5-aminolevulinate synthase. This enzyme, which requires pyridoxal 5’-phosphate (PLP) as a cofactor, catalyzes the first and rate-limiting step of heme synthesis in erythroid cells. XLSA is characterized by hypochromic microcytic anemia and ring sideroblasts in bone marrow, with most patients showing variable degrees of response to pyridoxine supplementation; however, female carriers of
ALAS2
mutations often present a distinct clinical phenotype. A comprehensive review of the literature reveals over 100 distinct
ALAS2
mutations linked to XLSA in more than 240 families. Here, we report seven new patients (four female cases) initially diagnosed with various conditions, later confirmed to have X-linked Sideroblastic Anemia due to ALAS2 mutations through genetic analysis. Among these, five represent novel
ALAS2
mutations, including the first ever reported stop-loss mutation in
ALAS2
associated with XLSA rather than X-linked dominant protoporphyria (XLDPP). Computational modelling of six reported cases revealed that four mutations significantly impact protein structure, conformation and cofactor interaction, consistent with our enzymatic assays demonstrating reduced ALAS2 activity. Furthermore, X-chromosome studies in female probands revealed a pronounced skewing of X-chromosome, which may provide an explanation for their distinct clinical manifestations in females.
Journal Article
Allogeneic hematopoietic stem cell transplantation and pre-transplant strategies in patients with NPM1-mutated acute myeloid leukemia: a single center experience
by
Haas, Rainer
,
Kasprzak, Annika
,
Kaivers, Jennifer
in
692/4028/67/1059/99
,
692/4028/67/1990/283/1897
,
Acute myeloid leukemia
2023
Patients with acute myeloid leukemia (AML) and nucleophosmin 1 gene mutations (NPM1
mut
) show a favorable prognosis with chemotherapy (CT) in the absence of negative prognostic genetic abnormalities. Between 2008 and 2021 64 patients with NPM1
mut
AML received alloHSCT because of additional adverse prognostic factors (1st line), inadequate response to or relapse during or after CT (2nd line). To expand the evidence in alloTX in NPM1
mut
AML, clinical and molecular data were retrospectively analyzed with respect to pre-transplant strategies and outcome. Patients with minimal residual disease negative (MRD−) CR at transplant had better 2-y-PFS and 2-y-OS (77% and 88%) than patients with minimal residual disease positive (MRD+) CR (41% and 71%) or patients with active disease (AD) at transplant (20% and 52%). The 2nd line patients with relapse after completing CT responded well to high dose cytarabine based salvage chemotherapy (salvage CT) in contrast to patients relapsing while still on CT (90% vs 20%, P = 0.0170). 2-y-PFS and 2-y-OS was 86% in patients who achieved a 2nd MRD− CR pre alloHSCT. Outcome in NPM1
mut
AML depends on disease burden at alloHSCT. Time and type of relapse in relation to CT are predictive for response to salvage CT.
Journal Article
Influence of platelet count at diagnosis and during the course of disease on prognosis in MDS patients
by
Haas, Rainer
,
Strupp Corinna
,
Germing Ulrich
in
Bone marrow
,
Medical diagnosis
,
Medical prognosis
2021
Thrombocytopenia at diagnosis and platelet drop within the first 6 months have an adverse effect on prognosis of MDS patients. We therefore were interested in the association and impact on prognosis of morphologic findings of megakaryocytes and platelets with platelet count at diagnosis, bleeding complications, and the drop of platelets during the course of disease. This retrospective analysis was based on 334 MDS patients from the Duesseldorf MDS registry that were followed up for blood counts, bleeding, transfusion dependency, and AML evolution and correlated with morphology of the megakaryocytes and platelets. Thrombocytopenia was found more frequently in higher risk MDS and was associated with hypocellularity of the megakaryocytes in the bone marrow. Signs of bleeding were present at diagnosis in 14% and occurred during the disease in 48% of all MDS patients. Death due to bleeding was ranked third behind infections and AML. A decrement of platelets during the first 6 months was associated with an inferior overall survival of 21 vs. 49 months and with a higher cumulative 2-year AML rate of 22.2% vs. 8.3% (p = 0.001). In a multivariate analysis, besides bone marrow blasts and karyotype, decreasing platelets were also associated with an inferior outcome. Signs of bleeding are present in a relevant number of MDS patients and account for significant morbidity and mortality in MDS. We could demonstrate the prognostic importance of decreasing platelets during the course of disease in all MDS patients, identifying patients at higher risk for death or AML progression.
Journal Article
Volasertib as a monotherapy or in combination with azacitidine in patients with myelodysplastic syndrome, chronic myelomonocytic leukemia, or acute myeloid leukemia: summary of three phase I studies
2022
Background
This report summarizes three phase I studies evaluating volasertib, a polo-like kinase inhibitor, plus azacitidine in adults with myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia, or acute myeloid leukemia.
Methods
Patients received intravenous volasertib in 28-day cycles (dose-escalation schedules). In Part 1 of 1230.33 (Study 1; NCT01957644), patients received 250–350 mg volasertib on day (D)1 and D15; in Part 2, patients received different schedules [A, D1: 170 mg/m
2
; B, D7: 170 mg/m
2
; C, D1 and D7: 110 mg/m
2
]. In 1230.35 (Study 2; NCT02201329), patients received 200–300 mg volasertib on D1 and D15. In 1230.43 (Study 3; NCT02721875), patients received 110 mg/m
2
volasertib on D1 and D8. All patients in Studies 1 and 2, and approximately half of the patients in Study 3, were scheduled to receive subcutaneous azacitidine 75 mg/m
2
on D1–7.
Results
Overall, 22 patients were treated (17 with MDS; 12 previously untreated). Across Studies 1 and 2 (
n
= 21), the most common drug-related adverse events were hematological (thrombocytopenia [
n
= 11]; neutropenia [
n
= 8]). All dose-limiting toxicities were grade 4 thrombocytopenia. The only treated patient in Study 3 experienced 18 adverse events following volasertib monotherapy. Studies 1 and 2 showed preliminary activity (objective response rates: 25 and 40%).
Conclusions
The safety of volasertib with azacitidine in patients with MDS was consistent with other volasertib studies. All studies were terminated prematurely following the discontinuation of volasertib for non-clinical reasons by Boehringer Ingelheim; however, safety information on volasertib plus azacitidine are of interest for future studies in other diseases.
Journal Article
Relapse patterns and treatment strategies in patients receiving allogeneic hematopoietic stem cell transplantation for myeloid malignancies
by
Haas, Rainer
,
Nachtkamp, Kathrin
,
Dienst, Ariane
in
Stem cell transplantation
,
Stem cells
,
Transplants & implants
2019
Allogeneic hematopoietic stem cell transplantation (aHSCT) cures a considerable number of patients with myeloid malignancies, but relapse is the most frequent cause of death. We retrospectively studied relapse rate, kinetics, treatment, and outcome after first aHSCT in 446 patients during a 13-year period. Relapse occurred in 167 patients after a median of 4.6 months (116 hematologic (HR), 38 molecular (MR), and 13 extramedullary relapses (XR)). Median survival after relapse was 8.4 months and 2-year overall survival was 25%. Regarding survival after relapse, type (MR/HR/XR) and timepoint of relapse (> 12 months), age (> 50), diagnosis (MDS/AML and sAML), and remission status at transplant (CR and untreated MDS vs. refractory disease) were relevant in univariate analyses, in multivariate analyses timepoint, and type of relapse, age, and diagnosis. One hundred fifty-six patients were treated, most frequently with hypomethylating agents (HMA, n = 109) or intensive chemotherapy (n = 12). Donor lymphocyte infusion (DLI) was administered to 99 patients. Second aHSCT was performed in three patients as first and in 21 as higher salvage treatment. A complete remission (CR) was achieved in 46 patients (30%). Among CR patients, 65% had received HMA and DLI. Median survival of patients achieving CR was 105 months and 2-year overall survival was 80%. We conclude that with HMA and DLI or second aHSCT, a substantial number of patients, who relapse after aHSCT, can re-achieve remission and long-term survival. Techniques to further improve the detection of minimal residual disease are urgently needed because early treatment of MR results in significantly better survival.
Journal Article
Impact of somatic mutations in myelodysplastic patients with isolated partial or total loss of chromosome 7
by
Kulasekararaj, Austin G
,
Germing Ulrich
,
Best, Steven
in
Chromosome 7
,
Chromosomes
,
Cytogenetics
2020
Monosomy 7 [−7] and/or partial loss of chromosome 7 [del(7q)] are associated with poor and intermediate prognosis, respectively, in myelodysplastic syndromes (MDS), but somatic mutations may also play a key complementary role. We analyzed the impact on the outcomes of deep targeted mutational screening in 280 MDS patients with −7/del(7q) as isolated cytogenetic abnormality (86 with del(7q) and 194 with −7). Patients with del(7q) or −7 had similar demographic and disease-related characteristics. Somatic mutations were detected in 79% (93/117) of patients (82% in −7 and 73% in del(7q) group). Median number of mutations per patient was 2 (range 0–8). There was no difference in mutation frequency between the two groups. Patients harbouring ≥2 mutations had a worse outcome than patients with <2 or no mutations (leukaemic transformation at 24 months, 38% and 20%, respectively, p = 0.044). Untreated patients with del(7q) had better overall survival (OS) compared with −7 (median OS, 34 vs 17 months, p = 0.034). In multivariable analysis, blast count, TP53 mutations and number of mutations were independent predictors of OS, whereas the cytogenetic subgroups did not retain prognostic relevance. This study highlights the importance of mutational analysis in terms of prognosis in MDS patients with isolated −7 or del(7q).
Journal Article
Monosomal karyotype and chromosome 17p loss or TP53 mutations in decitabine-treated patients with acute myeloid leukemia
2020
TP53 aberrations reportedly predict favorable responses to decitabine (DAC) in acute myeloid leukemia (AML). We evaluated clinical features and outcomes associated with chromosome 17p loss or TP53 gene mutations in older, unfit DAC-treated AML patients in a phase II trial. Of 178 patients, 25 had loss of 17p in metaphase cytogenetics; 24 of these had a complex (CK+) and 21 a monosomal karyotype (MK+). In analyses in all patients and restricted to CK+ and MK+ patients, 17p loss tended to associate with higher rates of complete remission (CR), partial remission (PR), or antileukemic effect (ALE). Despite favorable response rates, there was no significant OS difference between patients with or without loss of 17p in the entire cohort or in the CK+ and MK+ cohort. TP53 mutations were identified in eight of 45 patients with material available. Five of the eight TP53-mutated patients had 17p loss. TP53-mutated patients had similar rates of CR/PR/ALE but shorter OS than those with TP53 wild type (P = 0.036). Moreover, patients with a subclone based on mutation data had shorter OS than those without (P = 0.05); only one patient with TP53-mutated AML had a subclone. In conclusion, 17p loss conferred a favorable impact on response rates, even among CK+ and MK+ patients that however could not be maintained. The effect of TP53 mutations appeared to be different; however, patient numbers were low. Future research needs to further dissect the impact of the various TP53 aberrations in HMA-based combination therapies. The limited duration of favorable responses to HMA treatment in adverse-risk genetics AML should prompt physicians to advance allografting for eligible patients in a timely fashion.
Journal Article