Mono-Carbonyl Curcumin Analogs for Cancer Therapy.

Curcumin has long been recognized for its anti-inflammatory properties. An antitumor effect has been recently reported in curcumin and clinical trials are being conducted. However, a large amount of required intake to obtain the antitumor effect of curcumin has been regarded as a problem. Therefore, curcumin analogs have been created by many researchers to enhance the effects of curcumin. We have synthesized >50 curcumin analogs and revealed greater growth suppression of various tumor cells with mono-carbonyl analogs than curcumin. Mechanistically, mono-carbonyl analogs inhibited transcriptional activity (e.g., nuclear factor kappa B, signal transducer, and activator of transcription 3) or activated caspase-3. Additionally, mono-carbonyl analogs of curcumin control tumor cell metabolism. Herein, we summarize the current knowledge about mono-carbonyl curcumin analogs and discuss their potential clinical applications.

Incidence of hypophosphatemia in advanced cancer patients: a recent report from a single institution.

BACKGROUND: Recent approval of molecular-targeted agents has contributed to improving the therapeutic outcomes of advanced cancer patients. However, they result in unusual adverse events that rarely occur with cytotoxic agents, such as hypertension, hypomagnesemia, and an acne-like rash. Although hypophosphatemia can be induced by various agents, some kinds of molecular-targeted agents are known to induce it. In addition, cancer survivors may be at a risk of hypophosphatemia. METHODS: One hundred and seventy patients, who visited the Department of Clinical Oncology at Akita University from 1 April 2014 to 31 August 2016 were enrolled in this study after providing informed consent. Serum inorganic phosphorus levels were examined along with other routine clinical examinations. Correlation between the serum inorganic phosphorus level and other clinical data were also analyzed. RESULTS: Grade ≥2 severe hypophosphatemia (<2.5 mg/dL of phosphorus) was detected in 49.4% of patients, and grade ≥3 (<2.0 mg/dL of phosphorus) was observed in 22.9% patients. These results indicated that the presence of bone metastasis (p < 0.001), history of bone-modifying agents (p < 0.001) and molecular-targeted drugs (p = 0.001), and time from the date of the first visit to the date of minimum serum phosphorus level (p < 0.001) might correlate with hypophosphatemia. Multivariate logistic regression analysis showed that disease duration might be a risk factor (p = 0.0466). CONCLUSION: As hypophosphatemia can be induced by various factors in advanced cancer patients, the serum phosphorus level of cancer patients at risk should be cautiously examined.

Identification of anti-cancer chemical compounds using Xenopus embryos.

Cancer tissues have biological characteristics similar to those observed in embryos during development. Many types of cancer cells acquire pro-invasive ability through epithelial-mesenchymal transition (EMT). Similar processes (gastrulation and migration of cranial neural crest cells [CNCC]) are observed in the early stages of embryonic development in Xenopus during which cells that originate from epithelial sheets through EMT migrate to their final destinations. The present study examined Xenopus embryonic tissues to identify anti-cancer compounds that prevent cancer invasion. From the initial test of known anti-cancer drugs, AMD3100 (an inhibitor of CXCR4) and paclitaxel (a cytoskeletal drug targeting microtubules) effectively prevented migration during gastrulation or CNCC development. Blind-screening of 100 synthesized chemical compounds was performed, and nine candidates that inhibited migration of these embryonic tissues without embryonic lethality were selected. Of these, C-157 (an analog of podophyllotoxin) and D-572 (which is an indole alkaroid) prevented cancer cell invasion through disruption of interphase microtubules. In addition, these compounds affected progression of mitotic phase and induced apoptosis of SAS oral cancer cells. SAS tumors were reduced in size after intratumoral injection of C-157, and peritoneal dissemination of melanoma cells and intracranial invasion of glioma cells were inhibited by C-157 and D-572. When the other analogues of these chemicals were compared, those with subtle effect on embryos were not tumor suppressive. These results suggest that a novel chemical-screening approach based on Xenopus embryos is an effective method for isolating anti-cancer drugs and, in particular, targeting cancer cell invasion and proliferation.

Synthesis of 86 species of 1,5-diaryl-3-oxo-1,4-pentadienes analogs of curcumin can yield a good lead in vivo.

BACKGROUND: Curcumin is known to possess many anti-tumor properties such as inhibition of tumor growth and induction of apotosis. However, limited bioavailability of curcumin prevents its clinical application. A synthesized curcumin analog, 1,5-diaryl-3-oxo-1,4-pentadiene such as GO-Y030, has the improved anti-tumor potential in vitro as well as in mouse model of colorectal carcinogenesis. RESULTS: These compounds were divided into two groups; one is the higher anti-proliferative group, in which 79.7% of 1,5-diaryl-3-oxo-1,4-pentadienes were clustered. One of the 1,5-diaryl-3-oxo-1,4-pentadiene analogs, GO-Y078 has the most enhanced growth inhibition, and its solubility was improved, compared with curcumin. GO-Y078 inhibits NF-κB transactivation, as well as expression of TP53 and DR5 more effectively than curcumin. In a mouse model, GO-Y078 presented 1.4 fold more survival elongation that was not achieved by curcumin and GO-Y030. CONCLUSIONS: The 1,5-diaryl-3-oxo-1,4-pentadiene analogs can yield good lead compounds for cancer chemotherapy, to overcome low bioavailability of curcumin.

Synthesis and biological analysis of new curcumin analogues bearing an enhanced potential for the medicinal treatment of cancer.

Curcumin (diferuloylmethane) is a dietary phytochemical with low toxicity that exhibits growth-suppressive activity against a variety of cancer cells and possesses certain chemopreventive properties. Curcumin has already been the subject of several clinical trials for use as a treatment in human cancers. Synthetic chemical modifications of curcumin have been studied intensively in an attempt to find a molecule with similar but enhanced properties of curcumin. In this study, a series of novel curcumin analogues were synthesized and screened for anticancer activity. New analogues that exhibit growth-suppressive activity 30 times that of curcumin and other commonly used anticancer drugs were identified. Structurally, the new analogues are symmetrical 1,5-diarylpentadienone whose aromatic rings possess an alkoxy substitution at each of the positions 3 and 5. Analysis of the effects of the analogues on the expression of cancer-related genes usually affected by curcumin indicated that some induced the down-regulation of beta-catenin, Ki-ras, cyclin D1, c-Myc, and ErbB-2 at as low as one eighth the concentration at which curcumin normally has an effect. The analogues, however, exhibited neither harmful nor growth-suppressive effects on normal hepatocytes where oncogene products are not activated. They also exhibited no toxicities in vivo that they may provide effective alternative therapies for the prevention and treatment of some human cancers.

Expression, purification, and crystallization of endopolygalacturonase from a pathogenic fungus, Stereum purpureum, in Escherichia coli.

Endopolygalacturonases (EC 3.2.1.15) catalyze random hydrolysis of the alpha-1,4 glycosidic linkages in polygalacturonic acid, a component of pectin. Previously, we reported crystal structures of endogenously produced Stereum purprureum endopolygalacturonase I (endoPG I), both in its native form and complexed with its product, galacturonate. However, the substrate-binding mechanism of endoPG I is still unclear, because crystals have not yet been obtained with a substrate analog, or with mutant enzymes that can bind substrates. We describe here an expression system using Escherichia coli and a purification method to prepare functionally active endoPG I for such mutation and crystallographic studies. Expression in E. coli strain Origami (DE3) provided a soluble and active enzyme with proper disulfide bond formation, whereas the enzyme expressed in BL21 (DE3) was localized in inclusion bodies. A sufficient amount of recombinant endoPG I produced by Origami (DE3) was purified by a single-step procedure using cation exchange chromatography. The specific activity of recombinant endoPG I was equivalent to that of the enzyme produced by S. purpureum. Recombinant endoPG I was crystallized under the same conditions as those used for the native enzyme produced by S. purpureum. The crystals diffracted beyond 1.0 A resolution with synchrotron radiation.