Imidazo[1,2-b]pyrazole-7-carboxamides Induce Apoptosis in Human Leukemia Cells at Nanomolar Concentrations

Abstract

Leukemia, the malignancy of the hematopoietic system accounts for 10% of cancer cases with poor overall survival rate in adults; therefore, there is a high unmet medical need for the development of novel therapeutics. Eight imidazo[1,2-b]pyrazole-7-carboxamides have been tested for cytotoxic activity against five leukemia cell lines: Acute promyelocytic leukemia (HL-60), acute monocytic leukemia (THP-1), acute T-lymphoblastic leukemia (MOLT-4), biphenotypic B myelomonocytic leukemia (MV-4-11), and erythroleukemia (K-562) cells in vitro. Imidazo[1,2-b]pyrazole-7-carboxamides hampered the viability of all five leukemia cell lines with different potential. Optimization through structure activity relationship resulted in the following IC50 values for the most effective lead compound DU385: 16.54 nM, 27.24 nM, and 32.25 nM on HL-60, MOLT-4, MV-4-11 cells, respectively. Human primary fibroblasts were much less sensitive in the applied concentration range. Both monolayer or spheroid cultures of murine 4T1 and human MCF7 breast cancer cells were less sensitive to treatment with 1.5–10.8 μM IC50 values. Flow cytometry confirmed the absence of necrosis and revealed 60% late apoptotic population for MV-4-11, and 50% early apoptotic population for HL-60. MOLT-4 cells showed only about 30% of total apoptotic population. Toxicogenomic study of DU385 on the most sensitive MV-4-11 cells revealed altered expression of sixteen genes as early (6 h), midterm (12 h), and late response (24 h) genes upon treatment. Changes in ALOX5AP, TXN, and SOD1 expression suggested that DU385 causes oxidative stress, which was confirmed by depletion of cellular glutathione and mitochondrial membrane depolarization induction. Imidazo[1,2-b]pyrazole-7-carboxamides reported herein induced apoptosis in human leukemia cells at nanomolar concentrations.

Key genes with prognostic values in suppression of osteosarcoma metastasis using comprehensive analysis

“…This result is consistent with that of previous studies; the candidate genes are reportedly linked to tumor cells. The change in ALOX5AP expression can cause oxidative stress, which has some effects on human leukemia [33]. Codreanu et al reported that ALOX5AP could be a noninvasive candidate biomarker for lung cancer with global and targeted proteomics [34].…”

Single Cell Mass Cytometry Revealed the Immunomodulatory Effect of Cisplatin Via Downregulation of Splenic CD44+, IL-17A+ MDSCs and Promotion of Circulating IFN-γ+ Myeloid Cells in the 4T1 Metastatic Breast Cancer Model

“…The 4T1 cells were purchased from the ATCC (American Type Culture Collection, Manassas, VA, USA) and maintained as described previously [10]. Briefly, 4T1 were maintained in Roswell Park Memorial Institute 1640 medium (RPMI-1640) with 10% FCS.…”

“…Orthotopic transplantation of 4T1 cells offers a relevant tumor model to study efficacy of drug candidates or immune therapy regimens [8]. Previously, we showed the tumor promoting effect of mesenchymal stem cell (cancer associated fibroblast)-derived galectin-1 in the 4T1 model [9], and later on we screened an anti-cancer compound library of imidazo [1-2-b]pyrazole-7-carboxamides in both two-and three-dimensional cell cultures of 4T1 cells [10,11].…”

Imidazo[1,2-b]pyrazole-7-Carboxamide Derivative Induces Differentiation-Coupled Apoptosis of Immature Myeloid Cells Such as Acute Myeloid Leukemia and Myeloid-Derived Suppressor Cells

“…Chemotherapy-induced differentiation has been addressed in the late 1970s and still remained a therapeutic challenge to treat immature myeloid leukemias with high need for novel effective compounds [19]. We have previously synthetized a 67 member imidazo [1,2-b]pyrazole-7-carboxamide compound library with potent cytotoxic effect on HL-60 cells [20], and optimization of structure-activity relationship (SAR) resulted in the design of seven more active compounds [21]. These agents induced apoptosis in nanomolar range on HL-60 cells, but the way of action was not revealed.…”

“…These agents induced apoptosis in nanomolar range on HL-60 cells, but the way of action was not revealed. In order to explore the mechanism of action, our imidazo [1,2-b]pyrazole-7-carboxamide derivative, published earlier as DU325 [21], was further investigated to elicit its cytotoxic effect on human HL-60 and primary patient-derived AML cells.…”