Identifikation von Resistenzmechanismen für die Behandlung von Venetoclax-refraktären Hoch-Risiko CLLs
Zusammenfassung der Projektergebnisse
The BCL2 inhibitor venetoclax (VEN) has been approved to treat different hematological malignancies. Deciphering the evolution of cancer cells under therapeutic pressure is a crucial step to understand the mechanisms that lead to treatment resistance. To this end, we analyzed whole-exome sequencing data of eight chronic lymphocytic leukemia (CLL) patients that developed resistance upon BCL2-inhibition by VEN. Here, we report recurrent mutations in BTG1 (2 patients) and homozygous deletions affecting CDKN2A/B (3 patients) that developed during treatment, as well as a mutation in BRAF and a highlevel focal amplification of CD274 (PD-L1) that might pinpoint molecular aberrations offering structures for further therapeutic interventions. Since there is no common genetic alteration causing resistance to VEN in CLL and B cell lymphoma, we asked if epigenetic events might be involved in VEN resistance. Therefore, we employed whole exome sequencing, methylated DNA immunoprecipitation sequencing and genome wide CRISPR/Cas9 screening to investigate VEN resistance in aggressive lymphoma and high-risk CLL patients. We identified a regulatory CpG island within the PUMA promoter which is methylated upon VEN treatment, mediating PUMA downregulation on transcript and protein level. PUMA expression and sensitivity towards VEN can be restored by inhibition of methyltransferases. We can demonstrate that loss of PUMA results in metabolic reprogramming with higher OXPHOS and ATP production, resembling the metabolic phenotype that is seen upon VEN resistance. While PUMA loss is specific for acquired VEN resistance but not for acquired MCL1 resistance and is not seen in CLL patients after chemotherapy-resistance, BAX is key for sensitivity towards both VEN and MCL1 inhibition. As we found loss of BAX in Richter syndrome patients with TP53-loss after VEN failure, we defined BAX-mediated apoptosis to be critical for drug resistance but not for disease progression of CLL into aggressive DLBCL in vivo. A compound screen revealed TRAIL-mediated apoptosis as a target to overcome BAX deficiency and antibody or CAR redirected T cells eliminated VEN resistant lymphoma cells paving a clinically applicable way to overcome VEN resistance.
Projektbezogene Publikationen (Auswahl)
- Hypoxia-induced p38 MAPK activation reduces Mcl-1 expression and facilitates sensitivity towards BH3 mimetics in chronic lymphocytic leukemia. Leukemia. 2015 Apr;29(4):981-4
Huelsemann MF, Patz M, Beckmann L, Brinkmann K, Otto T, Fandrey J, Becker HJ, Theurich S, von Bergwelt-Baildon M, Pallasch CP, Zahedi RP, Kashkar H, Reinhardt HC, Hallek M, Wendtner CM, Frenzel LP
(Siehe online unter https://doi.org/10.1038/leu.2014.320) - miRs-138 and -424 control palmitoylationdependent CD95-mediated cell death by targeting acyl protein thioesterases 1 and 2 in CLL. Blood. 2015 May 7;125(19):2948-57
Berg V, Rusch M, Vartak N, Jüngst C, Schauss A, Waldmann H, Hedberg C, Pallasch CP, Bastiaens PI, Hallek M, Wendtner CM, Frenzel LP
(Siehe online unter https://doi.org/10.1182/blood-2014-07-586511) - B-cell-specific conditional expression of Myd88p.L252P leads to the development of diffuse large B-cell lymphoma in mice. Blood. 2016 Jun 2;127(22):2732-41
Knittel G, Liedgens P, Korovkina D, Seeger JM, Al-Baldawi Y, Al-Maarri M, Fritz C, Vlantis K, Bezhanova S, Scheel AH, Wolz OO, Reimann M, Möller P, López C, Schlesner M, Lohneis P, Weber AN, Trümper L; German International Cancer Genome Consortium Molecular Mechanisms in Malignant Lymphoma by Sequencing Project Consortium, Staudt LM, Ortmann M, Pasparakis M, Siebert R, Schmitt CA, Klatt AR, Wunderlich FT, Schäfer SC, Persigehl T, Montesinos-Rongen M, Odenthal M, Büttner R, Frenzel LP, Kashkar H, Reinhardt HC
(Siehe online unter https://doi.org/10.1182/blood-2015-11-684183) - Two mouse models reveal an actionable PARP1 dependence in aggressive chronic lymphocytic leukemia. Nat Commun. 2017 Jul 28;8(1):153
Knittel G, Rehkämper T, Korovkina D, Liedgens P, Fritz C, Torgovnick A, Al-Baldawi Y, Al-Maarri M, Cun Y, Fedorchenko O, Riabinska A, Beleggia F, Nguyen PH, Wunderlich FT, Ortmann M, Montesinos-Rongen M, Tausch E, Stilgenbauer S, Frenzel LP, Herling M, Herling C, Bahlo J, Hallek M, Peifer M, Buettner R, Persigehl T, Reinhardt HC
(Siehe online unter https://doi.org/10.1038/s41467-017-00210-6) - Clonal dynamics towards the development of venetoclax resistance in chronic lymphocytic leukemia. Nat Commun. 2018 Feb 20;9(1):727
Herling CD, Abedpour N, Weiss J, Schmitt A, Jachimowicz RD, Merkel O, Cartolano M, Oberbeck S, Mayer P, Berg V, Thomalla D, Kutsch N, Stiefelhagen M, Cramer P, Wendtner CM, Persigehl T, Saleh A, Altmüller J, Nürnberg P, Pallasch C, Achter V, Lang U, Eichhorst B, Castiglione R, Schäfer SC, Büttner R, Kreuzer KA, Reinhardt HC, Hallek M, Frenzel LP, Peifer M
(Siehe online unter https://doi.org/10.1038/s41467-018-03170-7) - ATM activity in T cells is critical for immune surveillance of lymphoma in vivo. Leukemia. 2020 Mar;34(3):771-786
Riabinska A, Lehrmann D, Jachimowicz RD, Knittel G, Fritz C, Schmitt A, Geyer A, Heneweer C, Wittersheim M, Frenzel LP, Torgovnick A, Wiederstein JL, Wunderlich CM, Ortmann M, Paillard A, Wößmann W, Borkhardt A, Burdach S, Hansmann ML, Rosenwald A, Perner S, Mall G, Klapper W, Merseburg A, Krüger M, Grüll H, Persigehl T, Wunderlich FT, Peifer M, Utermöhlen O, Büttner R, Beleggia F, Reinhardt HC
(Siehe online unter https://doi.org/10.1038/s41375-019-0618-2)
