demethylcantharidin and Neoplasms

Cantharidin and norcantharidin display anticancer activity against a broad range of tumor cell lines. In this study, we have synthesized a series of norcantharidin derivatives and evaluated their cytotoxic effects on four human tumor cell lines together with the genetically normal human diploid fibroblast line WI-38. One of our compounds (1S,4R)-3-((4-(4-(4-fluorophenyl)piperazin-1-ylsulfonyl) phenyl)carbamoyl)-7-oxa-bicyclo[2.2.1]heptane-2-carboxylic acid (12) exhibited potent cytotoxic effects on the tumor cell lines A-549, HepG2, HeLa, and HCT-8, whereas it was less toxic to WI-38 cells than its parent compound, norcantharidin. In addition, this compound inhibited protein phosphatase-1 activity and microtubule formation in HeLa cells, and it also interacts with calf thymus DNA.

Topics: Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Cell Proliferation; Cells, Cultured; DNA; Enzyme Inhibitors; Fibroblasts; Heterocyclic Compounds, 2-Ring; Humans; Inhibitory Concentration 50; Microtubules; Molecular Structure; Neoplasms; Protein Phosphatase 1; Structure-Activity Relationship; Sulfonamides

A Pt (IV) complex which combined the bioactivities of both oxaliplatin and demethylcantharidin (DMC) is synthesized and delivered by a polymer-drug conjugate for combination chemotherapy. Oxaliplatin is released from the polymer-drug conjugate within cancer cell by reduction to attack nuclear DNA, while a dose of DMC is also hydrolyzed subsequently to block DNA damage-induced defense mechanisms by serine/threonine phosphatase 2A (PP2A) inhibition. In vitro evaluation shows that the polymer-drug conjugate with dual modes of action upon cancer cells displays higher cytotoxicity against SKOV-3 cells than that of free drugs. This enhanced cytotoxicity is attributed to the synergistic effect between oxaliplatin and DMC, as well as the effective intracellular internalization of the micelles observed by confocal laser scanning microscopy (CLSM) imaging.

Topics: Cantharidin; Cell Line, Tumor; Humans; Micelles; Microscopy, Confocal; Neoplasms; Organoplatinum Compounds; Oxaliplatin; Polymers

Three new transition metal complexes [Mn2(DCA)2(bipy)2]·5H2O (1), [M2(DCA)2(bipy)2(H2O)]·10H2O(M=Ni(II)(2);Zn(II)(3)), (DCA=demethylcantharate, 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, C8H8O5) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra and X-ray diffraction techniques. Each metal ion was six-coordinated in complexes. Complex 1 has a Mn2O2 center. Complexes 2 and 3 have asymmetric binuclear structure. Great amount of intermolecular hydrogen-bonding and π-π(*) stacking interactions were formed in these complex structures. The DNA-binding properties of complexes were investigated by electronic absorption spectra and viscosity measurements. The DNA binding constants Kb/(Lmol(-1)) were 1.71×10(4) (1), 2.62×10(4) (2) and 1.59×10(4) (3) at 298 K. The complexes could quench the intrinsic fluorescence of bovine serum albumin (BSA) strongly through static quenching. The protein binding constants Ka/(L mol(-1)) were 7.27×10(4) (1), 4.55×10(4) (2) and 7.87×10(4) L mol(-1) (3) and binding site was one. The complexes bind more tightly with DNA and BSA than with ligands. Complexes 1 and 3 had stronger inhibition ratios than Na2(DCA) against human hepatoma cells (SMMC-7721) lines and human gastric cancer cells (MGC80-3) lines in vitro. Complex 3 showed the strongest antiproliferative activity against SMMC-7721 (IC50=29.46±2.12 μmol L(-1)) and MGC80-3 (IC50=27.02±2.38 μmol L(-1)), which shows potential in anti-cancer drug development.

Topics: 2,2'-Dipyridyl; Animals; Antineoplastic Agents; Cantharidin; Cattle; Cell Line, Tumor; Cell Proliferation; Coordination Complexes; Crystallography, X-Ray; DNA; Humans; Manganese; Models, Molecular; Neoplasms; Nickel; Serum Albumin, Bovine; Zinc

The identification of self-renewing and multipotent neural stem cells (NSCs) in the mammalian brain holds promise for the treatment of neurological diseases and has yielded new insight into brain cancer. However, the complete repertoire of signaling pathways that governs the proliferation and self-renewal of NSCs, which we refer to as the 'ground state', remains largely uncharacterized. Although the candidate gene approach has uncovered vital pathways in NSC biology, so far only a few highly studied pathways have been investigated. Based on the intimate relationship between NSC self-renewal and neurosphere proliferation, we undertook a chemical genetic screen for inhibitors of neurosphere proliferation in order to probe the operational circuitry of the NSC. The screen recovered small molecules known to affect neurotransmission pathways previously thought to operate primarily in the mature central nervous system; these compounds also had potent inhibitory effects on cultures enriched for brain cancer stem cells. These results suggest that clinically approved neuromodulators may remodel the mature central nervous system and find application in the treatment of brain cancer.

Topics: Animals; Cell Survival; Cells, Cultured; Mice; Molecular Structure; Neoplasms; Neurons; Pharmaceutical Preparations; Sensitivity and Specificity; Stem Cells

A range of amines was reacted with norcantharidin (2) to provide the corresponding norcantharimides (9-43). Treatment of norcantharidin with allylamine afforded the corresponding allyl-norcantharimide (20) which was amenable to epoxidation (mCPBA, 22) and subsequent ring opening (MeOH/H(+); 23) or alternatively, osmylation (OsO(4)/NMO; 24). These simple synthetic modifications of 2 facilitated the development of a novel series of norcantharimides displaying modest to good broad spectrum cytotoxicity against HT29 and SW480 (colorectal carcinoma); MCF-7 (breast adenocarcinoma); A2780 (ovarian carcinoma); H460 (lung carcinoma); A431 (epidermoid carcinoma); DU145 (prostate carcinoma); BE2-C (neuroblastoma); and SJ-G2 (glioblastoma). Analogues possessing a C(10), C(12) or C(14) alkyl chain or a C(12) linked bis-norcantharimide displayed the highest levels of cytotoxicity.

Topics: Antineoplastic Agents; Bridged Bicyclo Compounds, Heterocyclic; Drug Screening Assays, Antitumor; Humans; Molecular Structure; Neoplasms; Structure-Activity Relationship; Tumor Cells, Cultured