Novel bis-amide-based bis-thiazoles as Anti-colorectal Cancer Agents Through Bcl-2 Inhibition: Synthesis, In Vitro, and In Vivo studies.

BACKGROUND: Some heterocycles having bisamide linkage are receiving much interest due to their remarkable biological potencies and they are naturally occurring. Some bisamides and thiazole derivatives were found to inhibit the protein levels of Bcl-2 significantly. This prompted us to synthesize new bis(heterocyclic) derivatives having bisamide function to explore their anti-cancer activities. METHODS: Novel bis-amide-based bis-thiazoles and thiadiazoles were synthesized by reaction of a new bisthiosemicarbazone with a variety of hydrazonoyl chlorides, a-chloroacetylacetone and haloacetic acid derivatives. Most of the synthesized derivatives were tested for colorectal (HCT-116) and breast (MCF-7) cell lines using the MTT assay, with the apoptotic investigation through flow cytometric and RT-PCR analyses. RESULTS: Some derivatives were found to be highly cytotoxic against HCT-116 cells with an IC50 range of (10.44-13.76 µM) compared to 5-fluorouracil (5-FU) (IC50 = 11.78 µM). One product significantly stimulated apoptotic colorectal cancer cell death by 27.24-fold (50.13% compared to control 1.84%) by arresting the cell cycle at the G2/M phase. The obtained results revealed that compound 7f was more cytotoxic against HCT-116 cells than 5-FU. Compound 7f remarkably enhanced apoptotic colorectal cancer cell death and upregulated the propapoptotic genes (P53, BAX and Capases-3,-8,-9) and downregulated the anti-apoptotic gene, B-cell lymphoma 2 (Bcl-2). In vivo study exhibited that 7f-treatment caused tumor inhibition ratio (TIR%) of 50.45% compared to 54.86% in the 5-FU treatment, with a significant reduction in tumor mass and volume. The anti-tumor activity of compound 7f was accompanied by ameliorated hematological and biochemical analyses, histopathological improvement in treated liver tissues, and the immunohistochemical staining revealed Bcl-2 inhibition in agreement with the in vitro results. CONCLUSION: Compound 7f is an interesting candidate for further development as a chemotherapeutic anti-cancer agent.

Novel Bis-Thiazole Derivatives: Synthesis and Potential Cytotoxic Activity Through Apoptosis With Molecular Docking Approaches.

A series of bis-thiazoles 5a-g were synthesized from bis-thiosemicarbazone 3 with hydrazonoyl chlorides 4a-g. Reaction of 3 with two equivalents of α-halocarbonyl compounds 6-8, 10, and 12a-d afforded the corresponding bis-thiazolidines 9, 11, and 13a-d, respectively. Condensation of bis-thiazolidin-4-one 9 with different aromatic aldehydes furnished bis-thiazolidin-4-ones 14a-d. Compounds 5a-g, 9, and 13a,c,d were screened in vitro for their cytotoxic activities in a panel of cancer cell lines. Compounds 5a-c, 5f-g, and 9 exhibited remarkable cytotoxic activities, especially compound 5c with potent IC50 value 0.6 nM (against cervical cancer, Hela cell line) and compound 5f with high IC50 value 6 nM (against ovarian cancer, KF-28 cell line). Compound 5f-induced appreciated apoptotic cell death was measured as 82.76% associated with cell cycle arrest at the G1 phase. The apoptotic pathways activated in KF-28 cells treated with 5a, 5b, and 5f were further investigated. The upregulation of some pro-apoptotic genes, bax and puma, and the downregulation of some anti-apoptotic genes including the Bcl-2 gene were observed, indicating activation of the mitochondrial-dependent apoptosis. Together with the molecular docking studies of compounds 5a and 5b, our data revealed potential Pim-1 kinase inhibition through their high binding affinities indicated by inhibition of phosphorylated C-myc as a downstream target for Pim-1 kinase. Our study introduces a set of bis-thiazoles with potent anti-cancer activities, in vitro.