curcumin and 3-5-bis(3-4-5-trimethoxybenzylidene)-1-methylpiperidine-4-one

Triple-negative breast cancer (TNBC) has an aggressive phenotype and a poor prognosis owing to the high propensity for metastatic progression and the absence of specific targeted treatment. Here, we revealed that small-molecule RL71 targeting sarco/endoplasmic reticulum calcium-ATPase 2 (SERCA2) exhibited potent anti-cancer activity on all TNBC cells tested. Apart from apoptosis induction, RL71 triggered excessive autophagic cell death, the main contributor to RL71-induced TNBC cell death. RL71 augmented the release of Ca

Topics: Animals; Apoptosis; Autophagy; Calcium Signaling; Carcinogenesis; Cell Line, Tumor; Curcumin; Diarylheptanoids; Endoplasmic Reticulum Stress; Female; Humans; Intracellular Space; Mice, Nude; Mitochondria; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Signal Transduction; Small Molecule Libraries; Triple Negative Breast Neoplasms; Xenograft Model Antitumor Assays

Patients with triple negative breast cancer have a poor prognosis due in part to the lack of targeted therapies. In the search for novel drugs, our laboratory has developed a second-generation curcumin derivative, 3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidine-4-one (RL71), that exhibits potent in vitro cytotoxicity. To improve the clinical potential of this drug, we have encapsulated it in styrene maleic acid (SMA) micelles. SMA-RL71 showed improved biodistribution, and drug accumulation in the tumor increased 16-fold compared to control. SMA-RL71 (10 mg/kg, intravenously, two times a week for 2 weeks) also significantly suppressed tumor growth compared to control in a xenograft model of triple negative breast cancer. Free RL71 was unable to alter tumor growth. Tumors from SMA-RL71-treated mice showed a decrease in angiogenesis and an increase in apoptosis. The drug treatment also modulated various cell signaling proteins including the epidermal growth factor receptor, with the mechanisms for tumor suppression consistent with previous work with RL71 in vitro. The nanoformulation was also nontoxic as shown by normal levels of plasma markers for liver and kidney injury following weekly administration of SMA-RL71 (10 mg/kg) for 90 days. Thus, we report clinical potential following encapsulation of a novel curcumin derivative, RL71, in SMA micelles.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Curcumin; Diarylheptanoids; Disease Models, Animal; Female; Humans; Maleates; Mice, Inbred BALB C; Mice, SCID; Micelles; Neoplasm Proteins; Styrene; Tissue Distribution; Triple Negative Breast Neoplasms; Xenograft Model Antitumor Assays

Endotoxin-induced acute inflammatory diseases such as sepsis, mediated by excessive production of various proinflammatory cytokines, remain the leading cause of mortality in critically ill patients. Lipopolysaccharide (LPS), the characteristic endotoxin found in the outer membrane of Gram-negative bacteria, can induce the innate immunity system and through the myeloid differentiation protein 2 (MD2) and Toll-like receptor 4 (TLR4) complex, increase the production of inflammatory mediators. Our previous studies have found that a curcumin analog, L48H37 [1-ethyl-3,5-bis(3,4,5-trimethoxybenzylidene)piperidin-4-one], was able to inhibit LPS-induced inflammation, particularly tumor necrosis factor α and interleukin 6 production and gene expression in mouse macrophages. In this study, a series of biochemical experiments demonstrate L48H37 specifically targets MD2 and inhibits the interaction and signaling transduction of LPS-TLR4/MD2. L48H37 binds to the hydrophobic region of MD2 pocket and forms hydrogen bond interactions with Arg(90) and Tyr(102). Subsequently, L48H37 was shown to suppress LPS-induced mitogen-activated protein kinase phosphorylation and nuclear factor κB activation in macrophages; it also dose dependently inhibits the cytokine expression in macrophages and human peripheral blood mononuclear cells stimulated by LPS. In LPS-induced septic mice, both pretreatment and treatment with L48H37 significantly improved survival and protected lung injury. Taken together, this work identified a new MD2 specific inhibitor, L48H37, as a potential candidate in the treatment of sepsis.

Topics: Animals; Curcumin; Cytokines; Diarylheptanoids; Endotoxins; Humans; Lipopolysaccharides; Lymphocyte Antigen 96; Macrophages, Peritoneal; Male; Mice; Mice, Inbred C57BL; Primary Cell Culture; Protein Binding; Sepsis; Shock, Septic; Signal Transduction; Toll-Like Receptor 4; Transcription Factor RelA

While targeted agents are an important part of the treatment arsenal for colorectal cancer, there is still a lack of efficient small-molecule targeted agents based on the understanding of pathogenic molecular mechanisms. In this study, curcumin analog RL71 displayed potent cytotoxicity towards human colon cancer cells with an IC50 of 0.8 µM in SW480 cells and inhibited xenotransplanted tumor growth in a dose-dependent manner. Using affinity chromatography, we identified sarco/endoplasmic reticulum calcium-ATPase (SERCA) 2 as the binding target of RL71. Most notably, RL71 demonstrated special binding to SERCA2 at a novel site with the lowest estimated free energy -8.89 kcal mol(-1), and the SERCA2 residues critical for RL71 binding were identified. RL71 suppressed the Ca(2+)-ATPase activity of SERCA2 both in vitro and in vivo, accompanied by the induction of endoplasmic reticulum stress leading to apoptosis and G2/M cycle arrest in SW480 cells. In addition, RL71 showed synergistic cytotoxicity with the pan-SERCA inhibitor thapsigargin. These results suggest that RL71 could be a selective small-molecule inhibitor of SERCA2, and that it may serve as a lead compound for the study of targeted colorectal cancer therapy.

Topics: Animals; Antineoplastic Agents; Apoptosis; Blotting, Western; Calcium; Cell Cycle; Cell Proliferation; Colorectal Neoplasms; Curcumin; Diarylheptanoids; Endoplasmic Reticulum Stress; Female; Gene Expression Regulation, Neoplastic; Humans; Immunoenzyme Techniques; Mice; Mice, Nude; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

There is a need for the development of new, safe and efficacious drug therapies for the treatment of estrogen receptor (ER)-negative breast cancers. RL71 is a second-generation curcumin analog that exhibits potent cytotoxicity towards a variety of ER-negative breast cancer cells. Therefore, we have further examined the mechanism of this anticancer activity in three different ER-negative breast cancer cell lines. The mechanistic studies demonstrated that RL71 (1 µM) induced cell cycle arrest in the G2/M phase of the cell cycle. Moreover, RL71 (1 µM) caused 35% of SKBr3 cells to undergo apoptosis after 48 h and this effect was time-dependent. This correlated with an increase in cleaved caspase-3 as shown by western blotting. RL71 (1 µM) also decreased HER2/neu phosphorylation and increased p27 in SKBr3 cells. While in MDA-MB-231 and MDA-MB-468 cells RL71 (1 µM) significantly decreased Akt phosphorylation and transiently increased the stress kinases JNK1/2 and p38 MAPK. In addition, RL71 exhibited anti-angiogenic potential in vitro as it inhibited HUVEC cell migration and the ability of these cells to form tube-like networks. RL71 (8.5 mg/kg) was also orally bioavailable as it produced a peak plasma concentration of 0.405 µg/ml, 5 min after oral drug administration. Thus, our findings provide evidence that RL71 has potent anticancer activity and has potential to be further developed as a drug for the treatment of ER-negative breast cancer.

Topics: Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Caspase 3; Cell Line, Tumor; Cell Movement; Curcumin; Diarylheptanoids; Down-Regulation; Female; G2 Phase Cell Cycle Checkpoints; Human Umbilical Vein Endothelial Cells; Humans; JNK Mitogen-Activated Protein Kinases; Mice; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-akt; Receptor, ErbB-2; Receptors, Estrogen; Signal Transduction