cx-4945 and Breast-Neoplasms

The combination effect of 5-fluorouracil (5-FU) with either CX-4945 or a new inhibitor of protein kinase CK2, namely 14B (4,5,6,7-tetrabromo-1-(3-bromopropyl)-2-methyl-1. Combination index (CI) values were determined using an MTT-based assay and the Chou-Talalay model. The effect of the tested drug combinations on pro-apoptotic properties and cell cycle progression was examined using flow cytometry. The activation of FAK, p38 MAPK, and ERK1/2 kinases and the expression of selected pro-apoptotic markers in MDA-MB-231 cell line after the combined treatment were evaluated by the western blot method. Confocal microscopy was used to examine actin network in MDA-MB-231.. Our results showed that a synergistic effect (CI < 1) occurred in MDA-MB-231 after treatment with both combinations of 5-FU with 14B or CX-4945, whereas the combination of 5-FU and 14B evoked an antagonistic effect in MCF-7. We conclude that the synergistic interactions (CI < 1) observed for both the combinations of 5-FU and 14B or CX-4945 in MDA-MB-231 correlated with an activation of p38 MAPK, inhibition of FAK, increased expression of apoptogenic markers, prolongation of S-phase of cell cycle, and destabilization of actin network.. The obtained results support the recent observation that CK2 inhibitors can improve 5-FU-based anticancer therapy and FAK kinase can be an attractive molecular target in breast cancer therapy.

Topics: Breast Neoplasms; Casein Kinase II; Cell Line, Tumor; Cell Survival; Down-Regulation; Drug Synergism; Female; Fluorouracil; Focal Adhesion Kinase 1; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; Naphthyridines; p38 Mitogen-Activated Protein Kinases; Phenazines; Protein Kinase Inhibitors

Protein kinase CK2 was recently identified as a promising therapeutic target for combination therapy. Our study aims to investigate the anticancer effect of a simultaneous inhibition of thymidylate synthase (TS) and CK2 in MCF-7 breast cancer and CCRF-CEM leukemia cells.. The type of interaction between CK2 inhibitors: CX-4945, 4,5,6,7-tetrabromo-1H-benzimidazole (TBBi), or recently obtained 4,5,6,7-tetrabromo-2-methyl-1H-benzimidazol-1-yl)acetonitrile (2b) and TS-directed anticancer drug, 5-fluorouracil (5-FU) was determined using the MTT assay and a combination index method. The influence of the combined treatment on apoptosis in leukemia cells, as well as on cell-cycle progression and the levels of TS, CK2α and P-Ser529-p65 were determined in both cell lines, using flow cytometry and western blot analysis, respectively.. The best synergistic effect was observed in CCRF-CEM cell line with the combination of 5-FU and 2b which correlated with a decrease in the endocellular CK2 activity and enhancement of the pro-apoptotic effect.. The obtained results demonstrate the ability of CK2 inhibitors to enhance the efficacy of 5-FU in anticancer treatment, indicating a different molecular mechanism of the studied CK2 inhibitors interaction with 5-FU.

Topics: Antineoplastic Agents; Apoptosis; Benzimidazoles; Breast Neoplasms; Casein Kinase II; Cell Line, Tumor; Female; Fluorouracil; Humans; Leukemia; MCF-7 Cells; Naphthyridines; Phenazines; Protein Kinase Inhibitors; Thymidylate Synthase

A series of indeno[1,2-b]indole-9,10-dione derivatives were synthesized as human casein kinase II (CK2) inhibitors. The most potent inhibitors contained a N(5)-isopropyl substituent on the C-ring. The same series of compounds was found to also inhibit the breast cancer resistance protein ABCG2 but with totally different structure-activity relationships: a N(5)-phenethyl substituent was critical, and additional hydrophobic substituents at position 7 or 8 of the D-ring or a methoxy at phenethyl position ortho or meta also contributed to inhibition. The best ABCG2 inhibitors, such as 4c, 4h, 4i, 4j, and 4k, behaved as very weak inhibitors of CK2, whereas the most potent CK2 inhibitors, such as 4a, 4p, and 4e, displayed limited interaction with ABCG2. It was therefore possible to convert, through suitable substitutions of the indeno[1,2-b]indole-9,10-dione scaffold, potent CK2 inhibitors into selective ABCG2 inhibitors and vice versa. In addition, some of the best ABCG2 inhibitors, which displayed a very low cytotoxicity, thus giving a high therapeutic ratio, and appeared not to be transported, constitute promising candidates for further investigations.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Biological Transport; Breast Neoplasms; Casein Kinase II; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Female; HEK293 Cells; Humans; Indoles; MCF-7 Cells; Mitoxantrone; Models, Chemical; Molecular Structure; Neoplasm Proteins; Protein Kinase Inhibitors

Breast cancer is the most common malignancy in women worldwide and remains a major cause of mortality, thus necessitating further therapeutic advancements. In breast cancer, numerous cell signaling pathways are aberrantly activated to produce the myriad phenotypes associated with malignancy; such pathways include the PI3K/Akt/mTOR, NF-κB and JAK/STAT cascades. These pathways are highly interconnected, but one prominent lateral enhancer of each is the remarkably promiscuous kinase CK2. CK2 expression has been shown to be elevated in cancer, thus implicating it in tumorigenesis through its effects on oncogenic signaling cascades. In this study, we identify aberrant expression of CK2 subunits in human breast samples from The Cancer Genome Atlas dataset. Additionally, two specific small molecule inhibitors of CK2, CX-4945 and TBB, were used to examine the role of CK2 in two human breast cancer cell lines, MDA-MB-231 and MCF-7 cells. We show that CK2 inhibition attenuates constitutive PI3K/Akt/mTOR, NF-κB and STAT3 activation and inducible NF-κB and JAK/STAT activation and downstream transcriptional activity. CX-4945 treatment caused a range of phenotypic changes in these cell lines, including decreased viability, cell cycle arrest, apoptosis and loss of migratory capacity. Overall, these results demonstrate the tremendous potential of CK2 as a clinical target in breast cancer.

Topics: Breast Neoplasms; Casein Kinase II; Cell Line, Tumor; Cell Survival; Female; Humans; MCF-7 Cells; Naphthyridines; Phenazines; Phosphorylation; Protein Kinase Inhibitors; Signal Transduction; Tumor Cells, Cultured; Up-Regulation