BACKGROUND: Multiple myeloma (MM) is an incurable plasma cell malignancy, accounting for approximately 1% of all cancers. Despite recent advances in the treatment of MM, due to the introduction of proteasome inhibitors (PIs) such as bortezomib (BTZ) and carfilzomib (CFZ), relapses and disease progression remain common. Therefore, a major challenge is the development of novel therapeutic approaches to overcome drug resistance, improve patient outcomes, and broaden PIs applicability to other pathologies. METHODS: We performed genetic and drug screens to identify new synthetic lethal partners to PIs, and validated candidates in PI-sensitive and -resistant MM cells. We also tested best synthetic lethal interactions in other B-cell malignancies, such as mantle cell, Burkitt's and diffuse large B-cell lymphomas. We evaluated the toxicity of combination treatments in normal peripheral blood mononuclear cells (PBMCs) and bone marrow stromal cells (BMSCs). We confirmed the combo treatment' synergistic effects ex vivo in primary CD138+ cells from MM patients, and in different MM xenograft models. We exploited RNA-sequencing and Reverse-Phase Protein Arrays (RPPA) to investigate the molecular mechanisms of the synergy. RESULTS: We identified lysine (K)-specific demethylase 1 (LSD1) as a top candidate whose inhibition can synergize with CFZ treatment. LSD1 silencing enhanced CFZ sensitivity in both PI-resistant and -sensitive MM cells, resulting in increased tumor cell death. Several LSD1 inhibitors (SP2509, SP2577, and CC-90011) triggered synergistic cytotoxicity in combination with different PIs in MM and other B-cell neoplasms. CFZ/SP2509 treatment exhibited a favorable cytotoxicity profile toward PBMCs and BMSCs. We confirmed the clinical potential of LSD1-proteasome inhibition in primary CD138+ cells of MM patients, and in MM xenograft models, leading to the inhibition of tumor progression. DNA damage response (DDR) and proliferation machinery were the most affected pathways by CFZ/SP2509 combo treatment, responsible for the anti-tumoral effects. CONCLUSIONS: The present study preclinically demonstrated that LSD1 inhibition could provide a valuable strategy to enhance PI sensitivity and overcome drug resistance in MM patients and that this combination might be exploited for the treatment of other B-cell malignancies, thus extending the therapeutic impact of the project.

• Publikační typ
• časopisecké články MeSH

Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) show potent efficacy in several ALK-driven tumors, but the development of resistance limits their long-term clinical impact. Although resistance mechanisms have been studied extensively in ALK-driven non-small cell lung cancer, they are poorly understood in ALK-driven anaplastic large cell lymphoma (ALCL). Here, we identify a survival pathway supported by the tumor microenvironment that activates phosphatidylinositol 3-kinase γ (PI3K-γ) signaling through the C-C motif chemokine receptor 7 (CCR7). We found increased PI3K signaling in patients and ALCL cell lines resistant to ALK TKIs. PI3Kγ expression was predictive of a lack of response to ALK TKI in patients with ALCL. Expression of CCR7, PI3Kγ, and PI3Kδ were up-regulated during ALK or STAT3 inhibition or degradation and a constitutively active PI3Kγ isoform cooperated with oncogenic ALK to accelerate lymphomagenesis in mice. In a three-dimensional microfluidic chip, endothelial cells that produce the CCR7 ligands CCL19/CCL21 protected ALCL cells from apoptosis induced by crizotinib. The PI3Kγ/δ inhibitor duvelisib potentiated crizotinib activity against ALCL lines and patient-derived xenografts. Furthermore, genetic deletion of CCR7 blocked the central nervous system dissemination and perivascular growth of ALCL in mice treated with crizotinib. Thus, blockade of PI3Kγ or CCR7 signaling together with ALK TKI treatment reduces primary resistance and the survival of persister lymphoma cells in ALCL.

• MeSH
• anaplastická lymfomová kináza MeSH
• anaplastický velkobuněčný lymfom * farmakoterapie   genetika   patologie   MeSH
• endoteliální buňky metabolismus   MeSH
• fosfatidylinositol-3-kinasy MeSH
• inhibitory proteinkinas farmakologie   terapeutické užití   MeSH
• inhibitory tyrosinkinasy MeSH
• krizotinib farmakologie   terapeutické užití   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové mikroprostředí MeSH
• nádory plic * farmakoterapie   MeSH
• nemalobuněčný karcinom plic * farmakoterapie   MeSH
• receptory CCR7 genetika   MeSH
• tyrosinkinasové receptory metabolismus   MeSH
• tyrosinkinasy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

[Figure: see text].

• MeSH
• biologická evoluce MeSH
• buněčné linie MeSH
• cytokineze * MeSH
• dánio pruhované MeSH
• endozomální třídící komplexy pro transport metabolismus   MeSH
• fosfatidylinositol-3-kinasy genetika   metabolismus   MeSH
• fosfatidylinositol-4,5-difosfát metabolismus   MeSH
• fosfatidylinositoly metabolismus   MeSH
• katarakta metabolismus   patologie   MeSH
• lidé MeSH
• mutace MeSH
• myši MeSH
• oční čočka cytologie   růst a vývoj   metabolismus   MeSH
• předčasné stárnutí MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• proteiny dánia pruhovaného genetika   metabolismus   MeSH
• proteiny vázající vápník metabolismus   MeSH
• stárnutí buněk * MeSH
• tubulin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH