DOTA-NOC,a high-affinity ligand of somatostatin receptor subtypes 2, 3 and 5 for labelling with various radiometals

Earlier studies have shown that modification of the octapeptide octreotide in positions 3 and 8 may result in compounds with increased somatostatin receptor affinity that, if radiolabelled, display improved uptake in somatostatin receptor-positive tumours. The aim of a recent research study in our laboratory was to employ the parallel peptide synthesis approach by further exchanging the amino acid in position 3 of octreotide and coupling the macrocyclic chelator DOTA(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) to these peptides for labelling with radiometals like gallium-67 or -68, indium-111, yttrium-90 and lutetium-177. The purpose was to find radiopeptides with an improved somatostatin receptor binding profile in order to extend the spectrum of targeted tumours. A first peptide, [¹¹¹In,⁹⁰Y-DOTA]-1-Nal³-octreotide (¹¹¹In,⁹⁰Y-DOTA-NOC), was isolated which showed an improved profile. In^III-DOTA-NOC exhibited the following IC₅₀ values (nM) when studied in competition with [¹²⁵I][Leu⁸, d-Trp²², Tyr²⁵]somatostatin-28 (values for Y^III-DOTA-NOC are shown in parentheses): sstr2, 2.9±0.1 (3.3±0.2); sstr3, 8±2 (26±1.9); sstr5, 11.2±3.5 (10.4±1.6). Affinity towards sstr1 and 4 was very low or absent. In^III-DOTA-NOC is superior to all somatostatin-based radiopeptides having this particular type of binding profile, including DOTA-lanreotide, and has three to four times higher binding affinity to sstr2 than In^III,Y^III-DOTA-Tyr³-octreotide (In^III,Y^III-DOTA-TOC). In addition, [¹¹¹In]DOTA-NOC showed a specific and high rate of internalization into AR4-2J rat pancreatic tumour cells which, after 4 h, was about two times higher than that of [¹¹¹In]DOTA-TOC and three times higher than that of [¹¹¹In]DOTA-octreotide ([¹¹¹In]DOTA-OC). The internalized radiopeptides were externalized intact upon 2 h of internalization followed by an acid wash. After 2–3 h of externalization a plateau is reached, indicating a steady-state situation explained by reactivation of the receptors followed by re-endocytosis. Biodistribution studies in CA 20948 tumour-bearing rats showed rapid clearance from all sstr-negative tissues except the kidneys. At 4 h the uptake of [¹¹¹In]DOTA-NOC in the tumour and sstr-positive tissues, such as adrenals, stomach and pancreas, was three to four times higher than that of [¹¹¹In]DOTA-TOC. Differential blocking studies indicate that this is at least partially due to the uptake mediated by sstr3 and sstr5. These very promising preclinical data justify the use of this new radiopeptide for imaging and potentially internal radiotherapy studies in patients.Abbreviations of the common amino acids are in accordance with the recommendations of IUPAC-IUB [IUPAC-IUB Commission of Biochemical Nomenclature (CBN), Symbols for amino-acid derivatives and peptides, recommendations 1971. Eur J Biochem 1972; 27:201–207].     

Breast conserving surgery --7 years of experience

The breast cancer treatment is based nowadays on a new surgical option: breast-conserving surgery, which is reliable at least for the first and second stage of cancer, with radical intention, obviously. We have started to practice the breast-conserving surgery in our surgical clinic (at CFR Hospital, from Craiova) for 7 years; until now we have performed 159 breast-conserving operation and, as results, we have recorded 3 local recurrences (2.12%) and 1 death due to cancer evolution. Our protocol includes removal of the primary tumor with enough surrounding tissue to ensure negative margins of resectable specimen, associated with total axillary lymph-node dissection and postoperative breast irradiation. Our oncologist on different postoperative conditions indicated the chemotherapy: tumor size, axillary lymph node involvement, patient age, etc. The purpose of this paper is to emphasize our unassuming experience but especially to draw attention on important results, obtained by long-term monitoring the patient who underwent breast-conserving surgery, in a two prospective protocols, which demonstrate the importance and applicability of breast-conserving therapy. The conclusion of this study is that breast-conserving surgery followed by breast irradiation is reliable, as the results are similar with the radical mastectomies; the main objective is to obtain a good cosmetic result, which depends on tumor size/size of the breast ratio.     

Malignant peripheral nerve sheath tumor cell invasion is facilitated by Src and aberrant CD44 expression

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive malignancies that arise within peripheral nerves. These tumors occur with increased incidence in patients with neurofibromatosis type 1 (NF1), exhibiting increased Ras activity due to loss of the NF1 gene product, neurofibromin, and abnormal expression of the epidermal growth factor receptor (EGFR). We previously found that MPNSTs express increased levels of the CD44 family of transmembrane glycoproteins that have been implicated in tumor cell invasion and metastasis. In two MPNST cell lines, we have found that elevated CD44 expression and cell invasion are dependent on Src kinase activity but are independent of mitogen-activated protein kinases (MAPK) kinase (MEK) activity. In contrast, inhibition of Src kinase activity has no influence on MPNST cell proliferation. Reduction of CD44 levels, using antisense oligonucleotides, results in reduced MPNST cell invasion in vitro, suggesting that Src contributes in part to MPNST cell invasion by increasing CD44 levels. At least some of this increased CD44 expression results from elevated EGFR levels through a Src-dependent mechanism, consistent with the notion that EGFR promotes constitutive Src activation in MPNSTs. These data indicate that Src and CD44 are putative targets for the treatment of MPNST invasion and metastasis.     

Influence des acides gras polyinsaturés n-3 et des antioxydants alimentaires sur les acides gras de la viande et la lipoperoxydation chez le bovin en finition

This study aimed at analysing the impact, on beef lipids and fatty acids and on beef colour, of dietary lipid supplements provided by extruded linseeds (rich in n-3 polyunsaturated fatty acids, n-3 PUFA) alone or with extruded rapeseed (rich in n-6 and n-3 PUFA and in 18:1n-9) in association or not with dietary antioxidants in cull dairy cows in finition. Dietary linseeds increased significantly proportions of 18:3n-3 (+56% and +36% respectively), of total trans 18:1 (+66% and +105%); and of 9cis,11trans 18:2 (CLA) (+50% and +41%) in Longissimus thoracis and Semitendinosus muscles, 18:3n-3 and CLA being known to be beneficial for the human health. Antioxidant supplements (association of vitamin E with plant extracts rich in polyphenols, PERP) reinforced the stimulating effect of lipid supplements on proportions of 18:3 n-3, 18:1trans, and 9cis,11trans 18:2 in lipids of the two muscles. Dietary n-3 PUFA reduced the capacity of plasma to resist against lipoperoxidation (−11%) favouring the formation of peroxides such as conjugated dienes (× 1.75) and malonedialdehyde (MDA, ×2). Intensity of lipoperoxidation tended to increase in beef packaged under modified atmosphere rich in oxygen (O₂/CO₂: 70/30) of the linseed group (2.96 μg/g fresh tissue) when compared to that in the control group (2.19 μg/g, p = 0.1). Combined supply of vitamin E and PERP efficiently protected beef against lipoperoxidation, even in beef packaged under modified atmosphere rich in oxygen. Beef samples packaged under air from cows of the linseed group exhibited a more intense red colour than that of cows of the control group. In cows of the linseed group submitted to an emotional stress 2 hours before slaughtering, beef samples packaged under the air or the O₂-rich atmosphere had a red colour with a lower intensity that beef samples from cows of the linseed plus antioxidants group. In conclusion, feeding strategy for finishing cull cows combining lipid (from linseed rich in n-3 PUFA) and antioxidant (vitamin E + PERP) supplements improve the health value of beef fatty acids avoiding the major risks of beef lipoperoxidation and of alteration of beef colour whatever (i) the conditions of beef ageing and packaging (especially with O₂), (ii) the level of emotional stress of animals just before slaughtering.     

The methylenetetrahydrofolate reductase C677T mutation induces cell‐specific changes in genomic DNA methylation and uracil misincorporation: A possible molecular basis for the site‐specific cancer risk modification

The C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with a decreased risk of colon cancer although it may increase the risk of breast cancer. This polymorphism is associated with changes in intracellular folate cofactors, which may affect DNA methylation and synthesis via altered one‐carbon transfer reactions. We investigated the effect of this mutation on DNA methylation and uracil misincorporation and its interaction with exogenous folate in further modulating these biomarkers of one‐carbon transfer reactions in an in vitro model of the MTHFR 677T mutation in HCT116 colon and MDA‐MB‐435 breast adenocarcinoma cells. In HCT116 cells, the MTHFR 677T mutation was associated with significantly increased genomic DNA methylation when folate supply was adequate or high; however, in the setting of folate insufficiency, this mutation was associated with significantly decreased genomic DNA methylation. In contrast, in MDA‐MB‐435 cells, the MTHFR 677T mutation was associated with significantly decreased genomic DNA methylation when folate supply was adequate or high and with no effect when folate supply was low. The MTHFR 677T mutation was associated with a nonsignificant trend toward decreased and increased uracil misincorporation in HCT116 and MDA‐MB‐435 cells, respectively. Our data demonstrate for the first time a functional consequence of changes in intracellular folate cofactors resulting from the MTHFR 677T mutation in cells derived from the target organs of interest, thus providing a plausible cellular mechanism that may partly explain the site‐specific modification of colon and breast cancer risks associated with the MTHFR C677T mutation. © 2008 Wiley‐Liss, Inc.     

Lutein Treatment Effects on the Redox Status and Metalloproteinase-9 (MMP-9) in Oral Cancer Squamous Cells—Are There Therapeutical Hopes?

Carotenoids loaded in nanoparticles should be regarded as a promising way to increase the availability in healthy cells and to induce apoptosis in cancer. Lutein is a carotenoid that, in contrast to beta-carotene, has no known toxicities. Oral cancer represents one of the most frequent types of cancer world-wide with an incidence rate of about 9% of all types of cancer. Almost 95% of all oral cancers are represented by squamous cell carcinomas (OSCC). The aim of this study was to review and analyse the effects of lutein and Poly(d,l-lactide-co-glycolide) (PLGA) Nps containing lutein (Lut Nps) on oxidative stress biomarkers (OXSR-1, FOXO-3, TAC) and collagen degradation biomarker–MMP-9, in human cells BICR10 of buccal mucosa squamous carcinoma. Lut Nps were prepared by the emulsion-solvent evaporation method. MMP, OXSR-1, TAC, FOXO-3 and MMP-9 were measured in tumour cell lysates by the ELISA technique. Our results have shown that in Lut 100 cells and Lut Nps the OXSR1 (p < 0.001, p < 0.001) and TAC (p < 0.001, p < 0.001) values were significantly higher than in control cells. The Lut 100 and Lut Nps FOXO-3 levels revealed no significant differences versus the control. MMP-9 levels were significantly reduced (p < 0.001) in the Lut Nps cells versus control cells. In our study conditions, lutein and lutein Nps did not trigger an oxidative stress by ROS induction. However, lutein Nps treatment seemed to have a positive effect, by downregulating the MMP-9 levels. Loaded in Nps, lutein could be regarded as a protective factor against local invasiveness, in whose molecular landscape MMPs, and especially MMP-9 are the main actors.     

Cardiac function and myocardial perfusion immediately following maximal treadmill exercise inside the MRI room

Treadmill exercise stress testing is an essential tool in the prevention, detection, and treatment of a broad spectrum of cardiovascular disease. After maximal exercise, cardiac images at peak stress are typically acquired using nuclear scintigraphy or echocardiography, both of which have inherent limitations. Although CMR offers superior image quality, the lack of MRI-compatible exercise and monitoring equipment has prevented the realization of treadmill exercise CMR.It is critical to commence imaging as quickly as possible after exercise to capture exercise-induced cardiac wall motion abnormalities. We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table. We optimized the treadmill exercise CMR protocol in 20 healthy volunteers and successfully imaged cardiac function and myocardial perfusion at peak stress, followed by viability imaging at rest. Imaging commenced an average of 30 seconds after maximal exercise. Real-time cine of seven slices with no breath-hold and no ECG-gating was completed within 45 seconds of exercise, immediately followed by stress perfusion imaging of three short-axis slices which showed an average time to peak enhancement within 57 seconds of exercise. We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress. This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.