Synthesis of Curcumin Derivatives and Analysis of Their Antitumor Effects in Triple Negative Breast Cancer (TNBC) Cell Lines

We analyzed antitumor effects of a series of curcumin analogues. Some of them were obtained by reaction of substitution involving the two phenolic OH groups of curcumin while the analogues with a substituent at C-4 was prepared following an original procedure that regards the condensation of benzenesulfenic acid onto the nucleophilic central carbon of the curcumin skeleton. We analyzed cytotoxic effects of such derivatives on two TNBC (triple negative breast cancer) cell lines, SUM 149 and MDA-MB-231, but only three of them showed an IC50 in a lower micromolar range with respect to curcumin. We also focused on these three derivatives that in both cell lines exhibited a higher or at least equivalent pro-apoptotic effect than curcumin. The analysis of molecular mechanisms of action of the curcumin derivatives under study has highlighted that they decreased NF-κB transcriptional factor activity, and consequently the expression of some NF-κB targets. Our data confirmed once again that curcumin may represent a very good lead compound to design analogues with higher antitumor capacities and able to overcome drug resistance with respect to conventional ones, even in tumors difficult to treat as TNBC

Microcephaly and macrocephaly. A study on anthropometric and clinical data from 308 subjects

Head circumference is the auxological parameter that most correlates with developmental anomalies in childhood. Head circumference (HC) two standard deviations (SD) below or above the mean defines microcephaly and macrocephaly, respectively. The aim of this retrospective study was to explore anthropometric parameters and clinical characteristics among subjects with abnormalities in HC who had been referred for developmental assessment. One hundred and sixty four subjects with microcephaly and 144 subjects with macrocephaly were enrolled from birth to 18 months of age. Head circumference at birth and the association with variables related to maternal health status, gestational age, growth pattern, brain imaging and clinical characteristics were analyzed. In some cases, an etiological diagnosis was made. In the two considered conditions, we found different anthropometric and clinical associations, some of which were statistically significant, with implications for ongoing neurodevelopmental surveillance

Observations and radio tagging of Balaenoptera edeni near Puerto La Cruz, Venezuela

The 23 October to 13 November 1979 Venezuelan radio tagging and tracking experiments on whales (Balaenoptera edeni, Fig. 1) provided essential field tests of the new modifications to the WHOI radio whale tag (see list of tag reports), and the chance to try it on a new species. We found that we could approach and tag these whales from a slow (4 to 6 kt) vessel. Good radio tracking with automatic direction finding equipment was possible within 12 to 20 km, with longer ranges probable. In addition, the radio tags provided new information about the behavior of these whales.Prepared for the Office of Naval Research under Contract N00014-79-C-OO71; NR 083-004

Cetaceans of Venezuela: Their distribution and conservation status.

Sighting, stranding, and capture records of whales and dolphins for Venezuela were assembled and analyzed to document the Venezuelan cetacean fauna and its distribution in the eastern Caribbean. An attempt was made to confirm species identification for each of the records, yielding 443 that encompass 21 species of cetaceans now confirmed to occur in Venezuelan marine, estuarine, and freshwater habitats. For each species, we report its global and local distribution, conservation status and threats, and the common names used, along with our proposal for a Spanish common name. Bryde’s whale (Balaenoptera edeni) is the most commonly reported mysticete. The long-beaked common dolphin (Delphinus capensis) is the most frequent of the odontocetes in marine waters. The boto or tonina (Inia geoffrensis) was found to be ubiquitous in the Orinoco watershed. The distribution of marine records is consistent with the pattern of productivity of Venezuelan marine waters, i.e., a concentration at 63°07′W through 65°26′W with records declining to the east and to the west. An examination of the records for all cetaceans in the Caribbean leads us to conclude that seven additional species may be present in Venezuelan waters. (PDF file contains 61 pages.

Phytol and Heptacosane Are Possible Tools to Overcome Multidrug Resistance in an In Vitro Model of Acute Myeloid Leukemia

Drug resistance is the ability of cancer cells to gain resistance to both conventional and novel chemotherapy agents, and remains a major problem in cancer therapy. Resistance mechanisms are multifactorial and involve more strictly pharmacological factors, such as P-glycoprotein (P-gp) and biological factors such as inhibitor of apoptosis proteins (IAPs) and the nuclear factor-kappa B (NF-kB) pathway. Possible therapeutic strategies for the treatment of acute myeloid leukemia (AML) have increased in recent years; however, drug resistance remains a problem for most pa-tients. Phytol and heptacosane are the major compounds of Euphorbia intisy essential oil (EO) which were demonstrated to inhibit P-gp in a multidrug resistant in vitro model of AML. This study investigated the mechanism by which phytol and heptacosane improve P-gp-mediated drug transport. Phytol suppresses the P-gp expression via NF-kB inhibition and does not seem to act on the efflux system. Heptacosane acts as a substrate and potent P-gp inhibitor, demonstrating the ability to retain the substrate doxorubicin inside the cell and enhancing its cytotoxic effects. Our results suggest that these compounds act as non-toxic modulators of P-gp through different mechanisms and are able to revert P-gp-mediated drug resistance in tumor cells

Epigenetic changes and nuclear factor-\u3baB activation, but not microRNA-224, downregulate Raf-1 kinase inhibitor protein in triple\u2011negative breast cancer SUM 159 cells

Raf-1 kinase inhibitor protein (RKIP) is a tumor suppressor and metastasis inhibitor, which enhances drug\u2011induced apoptosis of cancer cells. Downregulation of RKIP may be significant in the biology of highly aggressive and drug\u2011resistant tumors, for example triple\u2011negative breast cancers (TNBCs). Potential causes for the low levels of RKIP expressed by SUM 159 TNBC cells were investigated in the present study. Bisulphite modification, methylation specific\u2011polymerase chain reaction (PCR) and a TransAM NF-\u3baB assay were performed and the results suggested that various mechanisms, including methylation of the gene promoter, histone deacetylation and nuclear factor\u2011\u3baB (NF\u2011\u3baB) activation, but not targeting by microRNA\u2011224 (miR/miRNA\u2011224), as determined by transfection of pre\u2011miR\u2011224 miRNA precursor or anti\u2011miR\u2011224 miRNA inhibitor, may downregulate RKIP in these cells. Furthermore, reverse transcription\u2011quantitative PCR, western blotting,3\u2011(4,5\u2011dimethylthiazol\u20112\u2011yl)\u20115\u2011(3\u2011carboxymethoxyphenyl)\u20112\u2011(4\u2011sulphophenyl)\u20112H\u2011tetrazolium cell growth assay and flow cytometry revealed that in SUM 159 cells, the demethylating agent 5\u2011aza\u20112'\u2011deoxycytidine (5\u2011AZA), the histone deacetylase inhibitor trichostatin A (TSA) and the NF\u2011\u3baB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) enhanced RKIP expression and resulted in significant cell growth inhibition and induction of apoptosis. 5\u2011AZA and TSA mainly produced additive antitumor effects, while the combination of DHMEQ and TSA exhibited significant synergy in cell growth inhibition and induction of apoptosis assays. Increasing evidence that aberrant activation of NF\u2011\u3baB signaling is a frequent characteristic of TNBC highlights the fact that this transcription factor may be a useful target for treatment of such tumors. In addition to DHMEQ, proteasome inhibitors may also represent valuable therapeutic resources in this context. Notably, proteasome inhibitors, in addition to the inhibition of NF\u2011\u3baB activation, may also restore RKIP levels by inhibiting proteasome degradation of the ubiquitinated protein. The current results contribute to the understanding of the molecular mechanisms of RKIP downregulation in TNBC and suggest possible novel therapeutic approaches for the treatment of these types of cancer

Plasma levels of lipoproteins and apolipoproteins in congenital hypothyroidism: effects of L-thyroxine substitution therapy

Thyroid status in humans is an important factor in the regulation of lipoprotein metabolism. There are several data on hypothyroidism in the adult population, but less information is available about congenital hypothyroidism. Since lipid metabolism at birth is substantially different from that of adults, it is not likely that the same abnormalities that occur in adult hypothyroidism are also present when this is diagnosed at early life. We studied 16 subjects with congenital hypothyroidism, seven at the time of diagnosis and also after normalization of thyroid hormone levels over a period of 2.0 +/- 1.0 months of substitution therapy with L-thyroxine (5.9 +/- 1.2 micrograms/kg/d) and nine already on L-thyroxine therapy for a period of 4.7 +/- 3.2 months. Thirty-nine apparently healthy subjects matched for age were selected as controls. In all subjects, total cholesterol (CHO), triglycerides (TG), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol (HDL-C), apolipoproteins (apo) A-I and B, lipoprotein(a) [Lp(a)] thyrotropin (TSH), (LDL-C), total and free thyroxine (T4), and triiodothyronine (T3) were determined. CHO, HDL-C, and apo A-I levels were significantly higher in patients at the time of diagnosis than in controls (respectively, P = .0079, .0007, and .0004), whereas TG, LDL-C, apo B, and Lp(a) levels were not significantly different. During L-thyroxine substitution therapy in these subjects, HDL-C and apo A-I levels significantly decreased (respectively, by a mean of -36.2% and -24.4%), with similar behavior in all subjects.(ABSTRACT TRUNCATED AT 250 WORDS

Determinants of enhanced thromboxane biosynthesis in renal transplantation

Background. Despite great improvement in patient and graft survival, the long-term morbidity and mortality in renal transplant recipients (RTRs) are still significant, with a high incidence of cardiovascular disease-related deaths. Methods. We investigated thromboxane (TXA2) biosynthesis and endothelial and coagulative activation in 65 patients who received a renal transplant. Results. The rate of TXA2 biosynthesis (urinary 11-dehydro-TXB2 excretion largely reflects platelet TXA2 production in vivo) was significantly (P < 0.0001) higher in RTRs than in healthy subjects. Plasma von Willebrand factor (vWF) and thrombin-antithrombin (TAT) complexes were significantly higher (P < 0.001) in RTRs compared with controls. Urinary 11-dehydro-TXB2 directly correlated with plasma vWF and cholesterol. We next examined the relative influence of cyclosporine A (CsA) on TXA2 biosynthesis and endothelial activation, comparing a group of RTRs not receiving CsA with an age- and sex-matched group of patients treated with CsA. Urinary excretion of 11-dehydro-TXB2 and plasma levels of vWF were significantly increased in RTRs who received CsA compared with those who did not. After an overall follow-up of 120 months, RTRs who experienced cardiovascular events had a higher frequency of abnormal plasma levels of vWF than patients who remained event free. Conclusion. Renal transplantation is associated with in vivo platelet activation highly related to endothelial activation. This is particularly evident in CsA-treated patients. Administration of drugs that are able to reduce or eliminate thromboxane-dependent platelet activation in vivo may be beneficial to reduce the risk of cardiovascular events in RTRs

Preclinical models in oncological pharmacology: limits and advantages

A wide range of experimental tumor models, each with distinct advantages and disadvantages, is nowadays available. Due to the inherent differences in their complexity and functionality, the choice of the model is usually dependent on the application. Thus, to advance specific knowledge, one has to choose and use appropriate models, which complexity is largely dependent on the hypotheses to test, that is on the objectives. Whatever the model chosen, the complexity of cancer is such that none of them will be able to fully represent it. In vitro tumor models have provided important tools for cancer research and still serve as low-cost screening platforms for drugs. The improved understanding of cancer as "organ system" has pushed for increased accuracy and physiological relevance of in vitro tumor models that have in parallel increased in complexity, diversifying their output parameters as they progressed in view to recapitulate the most critical aspects such as the dimensionality of cell cultures (2D versus 3D), the mechanical stimuli, the multicellular interactions, the immune interactions and the soluble signaling. Animal models represent the in vivo counterpart to cell lines and are commonly used for studies during the preclinical investigation of cancer therapy to determine the efficacy and safety of novel drugs. They are super to in vitro models in terms of physiological relevance offering imitation of parental tumors and a heterogeneous microenvironment as part of an interacting complex biochemical system. In the present review we describe advantages and limits of major preclinical models used in Oncological Pharmacology

Pharmacogenetic considerations for optimizing tacrolimus dosing in liver and kidney transplant patients

The introduction of tacrolimus in clinical practice has improved patient survival after organ transplant. However, despite the long use of tacrolimus in clinical practice, the best way to use this agent is still a matter of intense debate. The start of the genomic era has generated new research areas, such as pharmacogenetics, which studies the variability of drug response in relation to the genetic factors involved in the processes responsible for the pharmacokinetics and/or the action mechanism of a drug in the body. This variability seems to be correlated with the presence of genetic polymorphisms. Genotyping is an attractive option especially for the initiation of the dosing of tacrolimus; also, unlike phenotypic tests, the genotype is a stable characteristic that needs to be determined only once for any given gene. However, prospective clinical studies must show that genotype determination before transplantation allows for better use of a given drug and improves the safety and clinical efficacy of that medication. At present, research has been able to reliably show that the CYP3A5 genotype, but not the CYP3A4 or ABCB1 ones, can modify the pharmacokinetics of tacrolimus. However, it has not been possible to incontrovertibly show that the corresponding changes in the pharmacokinetic profile are linked with different patient outcomes regarding tacrolimus efficacy and toxicity. For these reasons, pharmacogenetics and individualized medicine remain a fascinating area for further study and may ultimately become the face of future medical practice and drug dosing