lfm-a13 and Breast-Neoplasms

Preclinical animal models of breast cancer provide the opportunity to identify chemopreventive drugs with single-agent activity as well as effective multi-modality regimens for primary as well as secondary prevention in high-risk persons. Our group has used the 7,12-dimethylbenz(a)anthracene (DMBA) mouse model of carcinogen-induced breast cancer to explore the clinical potential of two tyrosine kinase inhibitors and a nucleoside analog as chemopreventive agents. All three agents exhibited promising preclinical activity both as monotherapy and as components of combination therapy with the standard chemotherapy drug paclitaxel. The tumors developing despite chemoprevention were not only small and grew slowly, but they also displayed a uniquely more pro-apoptotic protein expression profile. Hence, our experimental chemopreventive drugs were capable of preventing the development of aggressive mammary gland tumors with an apoptosis-resistant protein expression profile.

Topics: Amides; Animals; Antineoplastic Agents; Breast Neoplasms; Chemoprevention; Female; Humans; Mammary Neoplasms, Experimental; Mice; Nitriles; Protein Kinase Inhibitors; Quinazolines

Topics: Adenocarcinoma; Amides; Aniline Compounds; Animals; Antineoplastic Agents; Breast Neoplasms; Drug Design; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Female; Genistein; Humans; Leukemia; Macaca fascicularis; Mice; Mice, Inbred BALB C; Mice, SCID; Models, Molecular; Molecular Structure; Neoplasm Proteins; Neoplasms; Nitriles; Protein Conformation; Protein Structure, Tertiary; Quinazolines; Recombinant Fusion Proteins; Sequence Alignment; Species Specificity; Structure-Activity Relationship; Tumor Cells, Cultured; Tumor Stem Cell Assay; Xenograft Model Antitumor Assays

Recombinant human erythropoietin (Epo) is an effective and convenient treatment for cancer-related anaemia. In our study for the first time, we evaluated the effect of simultaneous use of Epo and Bruton's tyrosine kinase (BTK) inhibitor LFM-A13 on the viability and tumour development of breast cancer cells. The results demonstrated that Epo significantly intensifies the anticancer activity of LFM-A13 in MCF-7 and MDA-MB-231. The featured therapeutic scheme efficiently blocked the tumour development in zebrafish experimental cancer model. Epo and LFM-A13 administered together resulted in effective cell killing, accompanied by attenuation of the BTK signalling pathways, loss of mitochondrial membrane potential (MMP), accumulation of apoptotic breast cancer cells with externalised PS, a slight increase in phase G0/G1 and a reduction in cyclin D1 expression. Simultaneous use of Epo with LFM-A13 inhibited early stages of tumour progression. This therapeutic scheme may be rationale for further possible research.

Topics: Adult; Aged; Aged, 80 and over; Amides; Antineoplastic Agents; Breast Neoplasms; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Erythropoietin; Female; Humans; Middle Aged; Molecular Structure; Nitriles; Structure-Activity Relationship; Tumor Cells, Cultured

Molecular modeling studies led to the identification of LFM-A13 (alpha-cyano-beta-hydroxy-beta-methyl-N-(2,5-dibromophenyl)propenamide) as a potent inhibitor of Polo-like kinase (Plk). LFM-A13 inhibited recombinant purified Plx1, the Xenopus homolog of Plk, in a concentration-dependent fashion, as measured by autophosphorylation and phosphorylation of a substrate Cdc25 peptide. LFM-A13 was a selective Plk inhibitor. While the human PLK3 kinase was also inhibited by LFM-A13 with an IC(50) value of 61 microM, none of the 7 other serine/threonine kinases, including CDK1, CDK2, CDK3, CHK1, IKK, MAPK1 or SAPK2a, none of the 10 tyrosine kinases, including ABL, BRK, BMX, c-KIT, FYN, IGF1R, PDGFR, JAK2, MET, or YES, or the lipid kinase PI3Kgamma were inhibited (IC(50) values >200-500 microM). The mode of Plk3 inhibition by LFM-A13 was competitive with respect to ATP with a K(i) value of 7.2 microM from Dixon plots. LFM-A13 blocked the cell division in a zebrafish (ZF) embryo model at the 16-cell stage of the embryonic development followed by total cell fusion and lysis. LFM-A13 prevented bipolar mitotic spindle assembly in human breast cancer cells and glioblastoma cells and when microinjected into living epithelial cells at the prometaphase stage of cell division, it caused a total mitotic arrest. Notably, LFM-A13-delayed tumor progression in the MMTV/neu transgenic mouse model of HER2 positive breast cancer at least as effectively as paclitaxel and gemcitabine. LFM-A13 showed a favorable toxicity profile in mice and rats. In particular there was no evidence of hematologic toxicity as documented by peripheral blood counts and bone marrow examinations. These results establish LFM-A13 as a small molecule inhibitor of Plk with in vitro and in vivo anti-proliferative activity against human breast cancer.

Topics: Amides; Animals; Antineoplastic Agents; Breast Neoplasms; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Disease Progression; DNA, Recombinant; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Female; Fluorescence; Humans; Mice; Mice, Inbred BALB C; Mice, Transgenic; Microinjections; Microscopy, Confocal; Models, Molecular; Nitriles; Polo-Like Kinase 1; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Rats; Zebrafish