12-o-retinoylphorbol-13-acetate and cobaltous-chloride

Multiple genetic mutations along with unusual epigenetic modifications play a major role in cancer development. Histone deacetylase (HDAC) enzyme overexpression observed in the majority of cancers is responsible for tumor suppressor gene silencing and activation of proto-oncogenes to oncogenes. Cinnamic acid derivatives exhibit anti-cancer potential through HDAC enzyme inhibition. We have synthesized a few cinnamyl sulfonamide hydroxamate derivatives (NMJ-1, -2 and -3) by already published in-house procedures and their purity, and chemical characterization were performed by NMR, mass spectrometry and elemental analysis. The anti-cancer activities were also evaluated against colon cancer. The rationale for synthesis was based on bioisosterism concept. To take the work forward, these compounds were considered for in vitro anti-angiogenic and anti-metastatic activities in cancer cells. The effectiveness of these compounds was determined by SRB assay. The compounds showed cancer cell cytotoxicity (IC50 range of 5.7 ± 0.43 to 20.5 ± 1.9 μM). The mechanism of compound-induced cell death involves an intrinsic apoptosis pathway which was supported by the following: increase in apoptotic index, arrest in cell cycle at G2/M phase, increase in annexin V binding and induction of p21(Waf1/Cip1) expression in the treated cells. Further, their target modulating effect, measured as the expression of acetyl-H3 histone and acetyl α-tubulin was determined by Western blots. Hyper acetylation of H3 histone and α-tubulin were observed. Furthermore, increased expression of cleaved caspase-3, cleaved PARP, total Bad was estimated by ELISA. The anti-angiogenic effect was examined through cobalt (II) chloride (CoCl2)-induced HIF-1α expression, where the compounds reduced the expression of induced HIF-1α. In addition, their anti-metastatic ability was determined through phorbol-12-myristate-13-acetate (PMA)-induced expression of MMP-2 and -9 by Western blotting and gelatin zymography. Inhibition of malignant cell migration was assessed by scratch wound assay. The compounds showed a decrease in cell migration and inhibition of induced MMP-2 and MMP-9 expression. NMJ-2 exhibited comparable activity to that of standard SAHA. Our findings indicate that NMJ series of compound have potent in vitro anti-cancer, anti-angiogenic and anti-metastatic activity through HDAC enzyme inhibition.

Topics: A549 Cells; Acetylation; Antineoplastic Agents; Apoptosis; Blotting, Western; Caspase 3; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cobalt; Cyclin-Dependent Kinase Inhibitor p21; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Hypoxia-Inducible Factor 1, alpha Subunit; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; MCF-7 Cells; Phorbol Esters; Poly(ADP-ribose) Polymerases; Sulfonamides; Tubulin; Tumor Suppressor Protein p53