Antitumor activity of natural compounds, curcumin and PKF118-310, as Wnt/ß-catenin antagonists against human osteosarcoma cells.

Aberrant activation of the Wnt/ß-catenin signaling pathway promotes osteosarcoma tumorigenesis and metastasis. In this study, we tested the hypothesis that osteosarcoma progression may be delayed by disrupting the Wnt/ß-catenin pathway using small molecule inhibitors such as curcumin and PKF118-310. Effective inhibitions of the Wnt/ß-catenin pathway by curcumin and PKF118-310 in osteosarcoma cells were shown by the suppression of both intrinsic and activated ß-catenin/Tcf transcriptional activities using luciferase reporter assays. Western blot analysis revealed that there was no change in the amount of cytosolic ß-catenin, although nuclear ß-catenin was markedly reduced by treatment with either compounds. We next performed wound healing and Matrigel invasion assays and observed a dose-dependent decrease in osteosarcoma cell migration and invasion with curcumin and PKF118-310 treatment. Overexpression of the wild-type ß-catenin plasmid in osteosarcoma cells resulted in enhanced cell invasiveness but this effect was significantly overcome by curcumin. Gelatin zymography and Western blotting showed that reduced cell invasion with curcumin and PKF118-310 treatment correlated with the activity and protein level of matrix metalloproteinase-9 under conditions of intrinsic or extrinsic Wnt/ß-catenin activation. Using cell apoptosis assay and cell cycle analysis, we further showed that the anti-proliferative effect of PKF118-310 is attributed to PKF118-310-induced apoptosis and G2/M phase arrest. Lastly, we observed that these anti-cancer effects correlated with the decreased expression of cyclin D1, c-Myc and survivin. Our findings strongly suggest that curcumin and PKF118-310 have great therapeutic potential for the treatment of osteosarcoma.

Primary mucinous adenocarcinoma of the epididymis: report of a rare case with molecular genetic characterization including mutation analysis of the TP53 gene.

We report a case of primary epididymal mucinous adenocarcinoma in a 60-year-old man who presented with a scrotal mass and subsequently developed pulmonary metastases. On immunohistochemistry the tumor was positive for villin and CK20 and negative for CK7, CDX2, and thyroid transcription factor-1. Molecular genetic analysis revealed an uncommon mutation; 249: AGG →ATG in the TP53 gene, which has not been previously described in association with a primary epididymal adenocarcinoma. Mutational analysis showed KRAS, BRAF, and VHL to be wild-type. No microsatellite instability was found.

Carcinoma cuniculatum of the esophagus and tongue: report of two cases, including TP53 mutational analysis.

Carcinoma cuniculatum (CC) is a rare variant of extremely well differentiated squamous cell carcinoma. We present the clinicopathological features of two cases of CC; one lingual and one esophageal case with a molecular genetic study regarding the TP53 gene mutational status. Case 1 was a 62 year old male with enlarging chronic ulcer in the tongue. Case 2 was a 77 year old male with progressive dysphagia and odynophagia. Both patients were treated surgically. Both tumors showed deeply invaginating, keratin-filled, burrowing crypts lined by very well differentiated squamous epithelium. The esophageal tumor showed varying degrees of reactive nuclear atypia largely limited to the areas with dense intratumoral infiltration of neutrophils. No mutation of TP53 was identified in the esophageal case. Cytologic atypia limited to areas of significant acute inflammation may occur in CC and should, in the absence of aggressive stromal invasion, not preclude a diagnosis of CC.

Functionalized curcumin analogs as potent modulators of the Wnt/ß-catenin signaling pathway.

Osteosarcoma is a primary bone malignancy with aggressive metastatic potential and poor prognosis rates. In our earlier work we have investigated the therapeutic potential of curcumin as an anti-invasive agent in osteosarcoma by its ability to regulate the Wnt/ß-catenin signaling pathway. However, the clinical use of curcumin is limited owing to its low potency and poor pharmacokinetic profile. In this study, an attempt was made to achieve more potent Wnt inhibitory activity in osteosarcoma cells by carrying out synthetic chemical modifications of curcumin. We synthesized a total of five series consisting of 43 curcumin analogs and screened in HEK293T cells for inhibition of ß-catenin transcriptional activity. Six promising analogs, which were 6.5- to 60-fold more potent than curcumin in inhibiting Wnt activity, were further assessed for their anti-invasive activity and Wnt inhibitory mechanisms. Western blot analysis showed disruption of ß-catenin protein nuclear translocation following treatment with analogs 2f, 3c and 4f. Using transwell assays, we also found that these compounds were more potent than 1a (curcumin) in impeding the invasion of osteosarcoma cells, possibly through suppressing MMP-9 activity. Structure-activity-relationship studies revealed that Wnt inhibitory effects could be enhanced by shortening and restraining the flexibility of the 7-carbon linker moiety connecting the terminal aromatic rings of curcumin and substituting both rings with appropriate substituents. Our results demonstrate that the synthesized curcumin analogs are more potent Wnt inhibitors in osteosarcoma cell lines as compared to parental curcumin and are good lead compounds for further development. Future in vivo tests with these compounds will define their therapeutic potentials as promising drug candidates for clinical treatment of osteosarcoma.

Identification of Michael acceptor-centric pharmacophores with substituents that yield strong thioredoxin reductase inhibitory character correlated to antiproliferative activity.

AIMS: The role of thioredoxin reductase (TrxR) in tumorigenesis has made it an attractive anticancer target. A systematic approach for development of novel compounds as TrxR inhibitors is currently lacking. Structurally diversified TrxR inhibitors share in common electrophilic propensities for the sulfhydryl groups, among which include the Michael reaction acceptors containing an α,ß-unsaturated carbonyl moiety. We aimed to identify features among structurally diversified Michael acceptor-based compounds that would yield a strong TrxR inhibitory character. RESULTS: Structurally dissimilar Michael acceptor-based natural compounds such as isobutylamides, zerumbone, and shogaols (SGs) were found to possess a poor TrxR inhibitory activity, indicating that a sole Michael acceptor moiety was insufficient to produce TrxR inhibition. The 1,7-diphenyl-hept-3-en-5-one pharmacophore in 3-phenyl-3-SG, a novel SG analog that possessed comparable TrxR inhibitory and antiproliferative potencies as 6-SG, was modified to yield 1,5-diphenyl-pent-1-en-3-one (DPPen) and 1,3-diphenyl-pro-1-en-3-one (DPPro, also known as chalcone) pharmacophores. These Michael acceptor-centric pharmacophores, when substituted with the hydroxyl and fluorine groups, gave rise to analogs displaying a TrxR inhibitory character positively correlated to their antiproliferative potencies. Lead analogs 2,2'-diOH-5,5'-diF-DPPen and 2-OH-5-F-DPPro yielded a half-maximal TrxR inhibitory concentration of 9.1 and 10.5 µM, respectively, after 1-h incubation with recombinant rat TrxR, with the C-terminal selenocysteine residue found to be targeted. INNOVATION: Identification of Michael acceptor-centric pharmacophores among diversified compounds demonstrates that a systematic approach to discover and develop Michael acceptor-based TrxR inhibitors is feasible. CONCLUSION: A strong TrxR inhibitory character correlated to the antiproliferative potency is attributed to structural features that include an α,ß-unsaturated carbonyl moiety centered in a DPPen or DPPro pharmacophore bearing hydroxyl and fluorine substitutions.

Independent predictors for mortality in patients with positive Stenotrophomonas maltophilia cultures.

INTRODUCTION: Stenotrophomonas maltophilia is an emerging pathogen in nosocomial infections that may result in high mortality. S. maltophilia often present as part of a polymicrobial culture and it is not well established when treatment is indicated. We aimed to identify predictors of mortality in patients with positive cultures of S. maltophilia. MATERIALS AND METHODS: A retrospective cohort study in a tertiary care medical centre was performed in 150 adult patients with positive cultures of S. maltophilia. Patients' demographics, underlying diseases, severity of illness, length of hospitalisation, prior antibiotic exposure, number/types of indwelling catheters, culture sites, and appropriateness of empiric therapy were collected. Logistic regression was used to determine the independent risk factor(s) for infection-attributed mortality. RESULTS: Ninety-nine males and 51 females were studied. The mean (SD) age and APACHE II score of the patients were 61.9 (16.0) and 14.0 (6.1), respectively. The respiratory tract was the most frequent site (55.3%) where S. maltophilia was isolated. Infection-attributed mortality was observed in 22 of the 150 patients (14.7 %). Admission to ICU [Odds ratio (OR), 3.767; 95% confidence interval (CI), 1.277-11.116, P = 0.016], and delayed effective treatment (OR, 18.684; 95% CI, 4.050-86.188; P <0.001) were identified as independent risk factors for mortality. CONCLUSIONS: Predictors of mortality in patients with positive cultures of S. maltophilia were identified, which may guide clinicians in patient assessment and devising therapeutic decisions. Further studies are needed to validate our results.

Ultra-performance liquid chromatography/time-of-flight mass spectrometry based metabolomics of raw and steamed Panax notoginseng.

At present, metabolite profiling is of growing importance in herbal medicine fields such as breeding, formulation, quality control and clinical trials. This preliminary study indicated that ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOFMS)-based metabolomics allows direct detection of down-stream derivatives of metabolites, arising from the herbal formulation process. This analytical approach allows the discrimination and tentative authentication of unique biomarkers related to different herbal extracts using unsupervised multivariate principal component analysis (PCA). The tentative identification of biomarkers is complemented significantly by the accurate mass measurement of TOFMS and the high resolution and high retention time reproducibility rendered by UPLC. The application of this approach in herbal extract discrimination and ginsenoside biomarker discovery of raw and steamed Panax notoginseng (Burk.) F.H. Chen is demonstrated and discussed.