tretinoin and midostaurin

Among elderly patients with acute myeloid leukemia (AML), especially those who are unfit for intensive chemotherapy, a policy of reduced-intensity chemotherapy or conservative observation has been chosen, resulting in unmet medical needs. Clinical trials using anticancer drugs including antimetabolites or drugs targeted to cell cycle-related molecules failed to show superiority over conventional treatments. Recently, drugs targeted to Bcl-2, SMO, FLT3, and IDH1/2 have been shown to prolong overall survival alone or in combination with reduced-intensity chemotherapy. These treatments are likely to reshape the therapeutic landscape of AML, which will be personalized for individual patients based on leukemia genetics.

Topics: Aged; Aged, 80 and over; Aminopyridines; Aniline Compounds; Antineoplastic Agents; Arsenic Trioxide; Azacitidine; Benzimidazoles; Bridged Bicyclo Compounds, Heterocyclic; Decitabine; fms-Like Tyrosine Kinase 3; Humans; Isocitrate Dehydrogenase; Leukemia, Myeloid, Acute; Molecular Targeted Therapy; Phenylurea Compounds; Precision Medicine; Proto-Oncogene Proteins c-bcl-2; Pyrazines; Smoothened Receptor; Staurosporine; Sulfonamides; Survival Rate; Tretinoin; Triazines

We conducted a phase I study using midostaurin (25 or 50 mg orally twice daily), all-trans retinoic acid (ATRA) and CLAG chemotherapy to target multiple pathways in relapsed/refractory AML. 10 patients received the combination and no dose-limiting toxicities were observed. Two patients (22 %) achieved complete remission and 1 patient (11 %) achieved complete remission with incomplete count recovery. Pharmacokinetic data showed that the 25 mg dosing of midostaurin achieved therapeutic levels with no significant interaction between midostaurin and ATRA. With evidence of activity of ATRA in NPM1-mutated AML and midostaurin in FLT3-ITD AML, this combination warrants further investigation.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Cladribine; Cytarabine; Female; fms-Like Tyrosine Kinase 3; Granulocyte Colony-Stimulating Factor; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Mutation; Nuclear Proteins; Nucleophosmin; Recurrence; Remission Induction; Staurosporine; Treatment Outcome; Tretinoin

Midostaurin combined with chemotherapy is currently used to treat newly diagnosed acute myeloid leukemia (AML) patients with FMS-like tyrosine kinase 3 (FLT3)-mutations. However, midostaurin acts as an antagonist to some chemotherapeutic agents in leukemia cell lines without FLT3 mutations. All-trans retinoic acid (ATRA) induces apoptosis when used in combination with midostaurin in FLT3-mutated AML cells. This combination has been shown to be safe in AML patients. However, the effect of this combination has not been investigated in AML without FLT3 mutations.. Cell proliferation was assessed by a cell counting assay. Cell death was evaluated by cell viability and Annexin-V assays. Cell differentiation was assessed by CD11b expression profiling and morphological analysis. To explore the underlying mechanisms, we studied the role of caspase3/7, Lyn, Fgr, Hck, RAF, MEK, ERK, AKT, PU.1, CCAAT/enhancer binding protein β (C/EBPβ) and C/EBPε by Western blot analysis and immunoprecipitation assays. Antitumor activity was also confirmed in mouse xenograft models established with AML cells.. In this study, 0.1 - 0.25 μM midostaurin (mido(L)) combined with ATRA induced differentiation while 0.25 - 0.5 μM midostaurin (mido(H)) combined with ATRA triggered apoptosis in some AML cell lines without FLT3-mutations. Midostaurin combined with ATRA (mido-ATRA) also exhibited antitumor activity in mouse xenograft models established with AML cells. Mechanistically, mido(H)-ATRA-induced apoptosis was dependent on caspase-3/7. Mido(L)-ATRA inhibited Akt activation which was associated with decreased activity of Lyn/Fgr/Hck, resulted in dephosphorylation of RAF S259, activated RAF/MEK/ERK, along with upregulating the protein levels of C/EBPβ, C/EBPε and PU.1. A MEK specific inhibitor was observed to suppress mido(L)-ATRA-induced increases in the protein levels of C/EBPs and PU.1 and mido(L)-ATRA-induced differentiation. Furthermore, inhibition of Akt activity promoted mido(L)-ATRA-induced downregulation of RAF S259 phosphorylation and mido(L)-ATRA-induced differentiation. Therefore, Lyn/Fgr/Hck-associated Akt inhibition activated RAF/MEK/ERK and controlled mido(L)-ATRA-induced differentiation by upregulation of C/EBPs and PU.1. Mido(L)-ATRA also promoted assembly of the signalosome, which may facilitate RAF activation.. Midostaurin combined with ATRA exerts antitumor activity against AML with wild-type FLT3 mutations in vitro and in vivo. These findings may provide novel therapeutic strategies for some AML patients without FLT3 mutations and imply a new target of midostaurin.

Topics: Animals; fms-Like Tyrosine Kinase 3; Humans; Leukemia, Myeloid, Acute; Mice; Mitogen-Activated Protein Kinase Kinases; Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Staurosporine; Tretinoin

Acute myeloid leukemia (AML) is a heterogeneous disease. Numerous molecular abnormalities have been identified in AML and, amongst these, FMS‑like tyrosine kinase 3 (FLT3) mutations are one of the most common somatic alterations detected. In the present study, an in vitro investigation was performed to evaluate the effects of all‑trans retinoic acid (ATRA) and PKC412, alone and in combination, in FLT3‑mutated AML cell lines. Trypan blue exclusion test, as well as morphological, western blot and isobologram analyses were conducted. The results indicated that the combined ATRA and PKC412 treatment exhibited additive or synergistic effects in FLT3‑mutated AML cell lines. These results provided in vitro evidence for the future clinical trials evaluating the effects of a combination treatment using PKC412 and ATRA on AML patients with FLT3‑mutations.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Synergism; fms-Like Tyrosine Kinase 3; Humans; Leukemia, Myeloid, Acute; Mutation; Protein Kinase Inhibitors; Staurosporine; Tretinoin

Topics: Adenine; Adenine Nucleotides; Aminoglycosides; Anti-Inflammatory Agents, Non-Steroidal; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Arabinonucleosides; Carbazoles; Clofarabine; Cytarabine; Dasatinib; Daunorubicin; fms-Like Tyrosine Kinase 3; Furans; Gemtuzumab; Humans; Leukemia, Myeloid, Acute; Naphthalimides; Organophosphonates; Prognosis; Protein Kinase Inhibitors; Pyrimidines; Sesquiterpenes; Staurosporine; Stem Cell Transplantation; Thiazoles; Tretinoin

Topics: Antineoplastic Agents; Azacitidine; Biomedical Research; Carbazoles; Carboplatin; Cytarabine; Daunorubicin; Decitabine; Enzyme Inhibitors; Etoposide; Flavonoids; Furans; Humans; Leukemia, Myeloid, Acute; Mitoxantrone; Piperidines; Quinolones; Staurosporine; Topotecan; Tretinoin

The production of gelatinase B by macrophages is relevant in the immunological and migratory functions of macrophages. CGP 41251, an inhibitor of protein kinase C (PKC), was found to stimulate the expression of gelatinase B in macrophages, as shown by the study of two different monocytic/macrophagic cell lines, mouse RAW 264.7 and human THP-1 cells. When human monocytes and rat peritoneal macrophages were treated with CGP 41251, insignificant increases of 10 and 25% were obtained. This can possibly be due to the presence of contaminating cells in these two enriched populations, since the CGP 41251 treatment of non-macrophagic cell lines inhibited their PMA-induced gelatinase B production. Taken together, these results suggest that the stimulatory effect of CGP 41251 is specific to cells of the monocytic lineage. Using RAW 264.7 cells as a model, the effect of CGP 41251 is additive to that obtained using lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA), as revealed by gelatin zymography and Northern blot analysis. The stimulatory effect of CGP 41251 on gelatinase B production in RAW 264.7 was: (a) inhibited by calphostin C (as is the LPS-induced response), indicating a PKC-dependence; (b) inhibited by dexamethasone (as opposed to the LPS-induced response); and (c) enhanced by addition of trans-retinoic acid (RA). In fact, RA can induce gelatinase B production, either alone or in synergy with LPS and/or CGP 41251, since the combination of the three agents gives the highest gelatinase B response, at both the protein and the mRNA levels. This represents an important observation considering the RA is now being tested as an anti-cancer agent and proposed for prevention studies.

Topics: Alkaloids; Animals; Base Sequence; Cells, Cultured; Collagenases; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; Humans; In Vitro Techniques; Lipopolysaccharides; Macrophages; Matrix Metalloproteinase 9; Molecular Sequence Data; Protein Kinase C; Rats; Rats, Inbred F344; Regulatory Sequences, Nucleic Acid; RNA, Messenger; Staurosporine; Tretinoin; Up-Regulation