Targeting leukemic side population cells by isatin derivatives of nicotinic acid amide.

Side population (SP) cells mediate chemoresistance in leukemia. However, chemical inhibition approach to target SP cells has been poorly studied. Herein, we report the discovery of isatin derivatives of nicotinic acid amide as potent side population cell inhibitors. The selected derivatives showed superior potency over the reference drug verapamil. Furthermore, the treatment increased chemosensitivity and inhibited the cell proliferation on three different leukemic cell lines, K562, THP-1 and U937, suggesting that both SP and the bulk of leukemic cells are affected. Moreover, treatment with the most potent compound Nic9 reduced the expression of ABCG2, demonstrating that side population inhibition effect of the target derivatives is at least via ABCG2 inhibition. Importantly, the target derivatives induced erythrocyte/dendritic differentiation to leukemic cells mainly through Musashi/Numb pathway modulation.

Fascin is involved in the chemotherapeutic resistance of breast cancer cells predominantly via the PI3K/Akt pathway.

BACKGROUND: A major therapeutic challenge for breast cancer is the ability of cancer cells to evade killing of conventional chemotherapeutic agents. We have recently reported the actin-bundling protein (fascin) as a major regulator of breast cancer metastasis and survival. METHODS: Survival of breast cancer patients that received chemotherapy and xenograft tumour model was used to assess the effect of chemotherapy on fascin-positive and -negative breast cancer cells. Molecular and cellular assays were used to gain in-depth understanding of the relationship between fascin and chemoresistance. RESULTS: We showed a significant correlation between fascin expression and shorter survival in breast cancer patients who received chemotherapy. In xenograft experiments, fascin-positive cancer cells displayed significantly more resistance to chemotherapy-mediated apoptotic cell death than fascin-negative counterparts. This increased chemoresistance was at least partially mediated through PI3K/Akt signalling, and was paralleled by increased FAK phosphorylation, enhanced expression of the inhibitor of apoptosis proteins (XIAP and Livin) and suppression of the proapoptotic markers (caspase 9, caspase 3 and PARP). CONCLUSIONS: This is the first report to demonstrate fascin involvement in breast cancer chemotherapeutic resistance, supporting the development of fascin-targeting drugs for better treatment of chemoresistance breast cancer.

Antiproliferative activity of novel thiophene and thienopyrimidine derivatives.

A novel series of newly synthesized thiophene derivatives, ethyl-4,5-dimethyl-2-(3-(3,4,5-trimethoxyphenyl)thioureido)thiophene-3-carboxylate 3, ethyl-2-[(2-(dimethylamino)ethoxy)mercapto)methyleneamino)]-4,5-dimethyl-thiophene-3-carboxylate 9, thienopyrimidines 4, 7, 10-20, triazolothienopyrimidines 5, 6 were prepared and tested for their antiproliferative activity. The structures of the synthesized compounds were confirmed on the basis of elemental analysis, IR, (1)H-NMR, (13)C-NMR and mass spectral data. The results showed that the synthesized compounds were more active on breast cancer than on colon cancer cell lines and the most potent compounds in this study are compounds 3 and 13 which exerted remarkable activity against MDA-MB-231 (breast cancer) and HT-29 (colon cancer) cell lines with IC50 values (40.68, 49.22 µM) for compound 3 and (34.04, 45.62 µM) for compound 13. Also, compounds 4-6, 9 showed a moderate activity against breast cancer cell line, while compounds 15, 19 and 20 showed no activity.

Synthesis, and docking studies of some fused-quinazolines and quinazolines carrying biological active isatin moiety as cell-cycle inhibitors of breast cancer cell lines.

3 series of novel fused heterocyclic systems, viz. triazolo[4,3-a]quinazolin-7-ones (3), 1 2 4 5-tetrazino[4,3-a]-quinazolin-8-ones (5) and Schiff's bases of isatin derivatives with 2-hydrazinoquinazolin-4-ones (7) have been synthesized. Several of them showed variable and promising in vitro antiproliferative activity against the MCF-7 cells. Compounds 3a-3c, 6, 7a-7 f showed promising activity (IC50=12.45-15.79 µM). Compound 7 f possessed notable cell cycle disrupting and apoptotic activities with enhanced selectivity against cancer cells, suggesting the potential for the development of new selective cell cycle inhibitors. In silico docking study of the compound 7 f with EGFR enzyme postulated that the designed compound might act on the same enzyme target where DJK_3021_A x-ray structure acted.