Tumor heterogeneity and cancer stem cell paradigm: updates in concept, controversies and clinical relevance.

Although tumor heterogeneity is widely accepted, the existence of cancer stem cells (CSCs) and their proposed role in tumor maintenance has always been challenged and remains a matter of debate. Recently, a path-breaking chapter was added to this saga when three independent groups reported the in vivo existence of CSCs in brain, skin and intestinal tumors using lineage-tracing and thus strengthens the CSC concept; even though certain fundamental caveats are always associated with lineage-tracing approach. In principle, the CSC hypothesis proposes that similar to normal stem cells, CSCs maintain self renewal and multilineage differentiation property and are found at the central echelon of cellular hierarchy present within tumors. However, these cells differ from their normal counterpart by maintaining their malignant potential, alteration of genomic integrity, epigenetic identity and the expression of specific surface protein profiles. As CSCs are highly resistant to chemotherapeutics, they are thought to be a crucial factor involved in tumor relapse and superficially appear as the ultimate therapeutic target. However, even that is not the end; further complication is attributed by reports of bidirectional regeneration mechanism for CSCs, one from their self-renewal capability and another from the recently proposed concept of dynamic equilibrium between CSCs and non-CSCs via their interconversion. This phenomenon has currently added a new layer of complexity in understanding the biology of tumor heterogeneity. In-spite of its associated controversies, this area has rapidly emerged as the center of attention for researchers and clinicians, because of the conceptual framework it provides towards devising new therapies.

Cancer incidence in Vaud (2003-2007)

CANCER CARE FACILITIES: In 2005, the registration area had about 3200 hospital beds available for cancer diagnosis and treatment (about 5 per 1000 residents). There were about 3600 hospital medical residents and private practitioners (1 per 180 residents). The canton has a major, multidisciplinary, public university oncology and radiotherapy centre and two private radiotherapy units (available to all residents), as well as several peripheral (mostly hospital-based) medical and surgical oncology facilities and specialists. REGISTRY STRUCTURE AND METHODS: The registry is part of the Cancer Epidemiology Unit of the Institute of Social and Preventive Medicine within the Faculty of Biology and Medicine of the University of Lausanne. Notiĺcation is voluntary. The registry's main sources of information are the University Institute of Pathology at the University of Lausanne and three major private pathology laboratories. Passive and active follow-up are conducted. Data on all deaths in the canton (including cancer deaths) are available. Other features of the registry are good registration of non-melanoma skin cancers, linkage of reports of selected preneoplastic conditions to the registry database (to study subsequent cancer risk), analysis.

Fulvestrant with or without selumetinib, a MEK 1/2 inhibitor, in breast cancer progressing after aromatase inhibitor therapy: A multicentre randomised placebo-controlled double-blind phase II trial, SAKK 21/08.

BACKGROUND: Second line endocrine therapy has limited antitumour activity. Fulvestrant inhibits and downregulates the oestrogen receptor. The mitogen-activated protein kinase (MAPK) pathway is one of the major cascades involved in resistance to endocrine therapy. We assessed the efficacy and safety of fulvestrant with selumetinib, a MEK 1/2 inhibitor, in advanced stage breast cancer progressing after aromatase inhibitor (AI). PATIENTS AND METHODS: This randomised phase II trial included postmenopausal patients with endocrine-sensitive breast cancer. They were ramdomised to fulvestrant combined with selumetinib or placebo. The primary endpoint was disease control rate (DCR) in the experimental arm. ClinicalTrials.gov Indentifier: NCT01160718. RESULTS: Following the planned interim efficacy analysis, recruitment was interrupted after the inclusion of 46 patients (23 in each arm), because the selumetinib-fulvestrant arm did not reach the pre-specified DCR. DCR was 23% (95% confidence interval (CI) 8-45%) in the selumetinib arm and 50% (95% CI 27-75%) in the placebo arm. Median progression-free survival was 3.7months (95% CI 1.9-5.8) in the selumetinib arm and 5.6months (95% CI 3.4-13.6) in the placebo arm. Median time to treatment failure was 5.1 (95% CI 2.3-6.7) and 5.6 (95% CI 3.4-10.2) months, respectively. The most frequent treatment-related adverse events observed in the selumetinib-fulvestrant arm were skin disorders, fatigue, nausea/vomiting, oedema, diarrhoea, mouth disorders and muscle disorders. CONCLUSIONS: The addition of selumetinib to fulvestrant did not show improving patients' outcome and was poorly tolerated at the recommended monotherapy dose. Selumetinib may have deteriorated the efficacy of the endocrine therapy in some patients.

Optimising approaches to active immunotherapy of cancer

The design of therapeutic cancer vaccines is aimed at inducing high numbers and potent T cells that are able to target and eradicate malignant cells. This calls for close collaboration between cells of the innate immune system, in particular dendritic cells (DCs), and cells of the adaptive immune system, notably CD4+ helper T cells and CD8+ cytotoxic T cells. Therapeutic vaccines are aided by adjuvants, which can be, for example, Toll¬like Receptor agonists or agents promoting the cytosolic delivery of antigens, among others. Vaccination with long synthetic peptides (LSPs) is a promising strategy, as the requirement for their intracellular processing will mainly target LSPs to professional antigen presenting cells (APCs), hence avoiding the immune tolerance elicited by the presentation of antigens by non-professional APCs. The unique property of antigen cross-processing and cross-presentation activity by DCs plays an important role in eliciting antitumour immunity given that antigens from engulfed dead tumour cells require this distinct biological process to be processed and presented to CD8+T cells in the context of MHC class I molecules. DCs expressing the XCR1 chemokine receptor are characterised by their superior capability of antigen cross- presentation and priming of highly cytotoxic T lymphocyte (CTL) responses. Recently, XCR1 was found to be also expressed in tissue-residents DCs in humans, with a simitar transcriptional profile to that of cross- presenting murine DCs. This shed light into the value of harnessing this subtype of XCR1+ cross-presenting DCs for therapeutic vaccination of cancer. In this study, we explored ways of adjuvanting and optimising LSP therapeutic vaccinations by the use, in Part I, of the XCLl chemokine that selectively binds to the XCR1 receptor, as a mean to target antigen to the cross-presenting XCR1+ DCs; and in Part II, by the inclusion of Q.S21 in the LSP vaccine formulation, a saponin with adjuvant activity, as well as the ability to promote cytosolic delivery of LSP antigens due to its intrinsic cell membrane insertion activity. In Part I, we designed and produced XCLl-(OVA LSP)-Fc fusion proteins, and showed that their binding to XCR1+ DCs mediate their chemoattraction. In addition, therapeutic vaccinations adjuvanted with XCLl-(OVA LSP)-Fc fusion proteins significantly enhanced the OVA-specific CD8+ T cell response, and led to complete tumour regression in the EL4-OVA model, and significant control of tumour growth in the B16.0VA tumour model. With the aim to optimise the co-delivery of LSP antigen and XCLl to skin-draining lymph nodes we also tested immunisations using nanoparticle (NP)-conjugated OVA LSP in the presence or absence of XCLl chemokine. The NP-mediated delivery of LSP potentiated the CTL response seen in the blood of vaccinated mice, and NP-OVA LSP vaccine in the presence of XCLl led to higher blood frequencies of OVA-specific memory-precursor effector cells. Nevertheless, in these settings, the addition XCLl to NP-OVA LSP vaccine formulation did not increase its antitumour therapeutic effect. In the Part II, we assessed in HLA-A2/DR1 mice the immunogenicity of the Melan-AA27L LSP or the Melan-A26. 35 AA27l short synthetic peptide (SSP) used in conjunction with the saponin adjuvant QS21, aiming to identify a potent adjuvant formulation that elicits a quantitatively and qualitatively strong immune response to tumour antigens. We showed a high CTL immune response elicited by the use of Melan-A LSP or SSP with QS21, which both exerted similar killing capacity upon in vivo transfer of target cells expressing the Melan-A peptide in the context of HLA-A2 molecules. However, the response generated by the LSP immunisation comprised higher percentages of CD8+T cells of the central memory phenotype (CD44hl CD62L+ and CCR7+ CD62L+) than those of SSP immunisation, and most importantly, the strong LSP+QS21 response was strictly CD4+T cell-dependent, as shown upon CD4 T cell depletion. Altogether, these results suggest that both XCLl and QS21 may enhance the ability of LSP to prime CD8 specific T cell responses, and promote a long-term memory response. Therefore, these observations may have important implications for the design of protein or LSP-based cancer vaccines for specific immunotherapy of cancer -- Les vacans thérapeutiques contre le cancer visent à induire une forte et durable réponse immunitaire contre des cellules cancéreuses résiduelles. Cette réponse requiert la collaboration entre le système immunitaire inné, en particulier les cellules dendrites (DCs), et le système immunitaire adaptatif, en l'occurrence les lymphocytes TCD4 hdper et CD8 cytotoxiques. La mise au point d'adjuvants et de molécules mimant un agent pathogène tels les ligands TLRs ou d'autres agents facilitant l'internalisation d'antigènes, est essentielle pour casser la tolérance du système immunitaire contre les cellules cancéreuses afin de générer une réponse effectrice et mémoire contre la tumeur. L'utilisation de longs peptides synthétiques (LSPs) est une approche prometteuse du fait que leur présentation en tant qu'antigénes requiert leur internalisation et leur transformation par les cellules dendrites (DCs, qui sont les mieux à même d'éviter la tolérance immunitaire. Récemment une sous-population de DCs exprimant le récepteur XCR1 a été décrite comme ayant une capacité supérieure dans la cross-présentation d'antigènes, d'où un intérêt à développer des vaccins ciblant les DCs exprimant le XCR1. Durant ma thèse de doctorat, j'ai exploré différentes approches pour optimiser les vaccins avec LSPs. La première partie visait à cibler les XCR1-DCs à l'aide de la chemokine XCL1 spécifique du récepteur XCR1, soit sou s la forme de protéine de fusion XCL1-OVA LSP-Fc, soit associée à des nanoparticules. La deuxième partie a consisté à tester l'association des LSPs avec I adjuvant QS21 dérivant d'une saponine dans le but d'optimiser l'internalisation cytosolique des longs peptides. Les protéines de fusion XCLl-OVA-Fc développées dans la première partie de mon travail, ont démontré leur capacité de liaison spécifique sur les XCRl-DCs associée à leur capacité de chemo-attractio. Lorsque inclues dans une mmunisation de souris porteuse de tumeurs établies, ces protéines de fusion XCL1-0VA LSP-Fc et XCLl-Fc plus OVA LSP ont induites une forte réponse CDS OVA spécifique permettant la complète régression des tumeurs de modèle EL4- 0VA et un retard de croissance significatif de tumeurs de type B16-0VA. Dans le but d'optimiser le drainage des LSPs vers es noyaux lymphatiques, nous avons également testé les LSPs fixés de manière covalente à des nanoparticules co- injectees ou non avec la chemokine XCL1. Cette formulation a également permis une forte réponse CD8 accompagnée d'un effet thérapeutique significatif, mais l'addition de la chemokine XCL1 n'a pas ajouté d'effet anti-tumeur supplémentaire. Dans la deuxième partie de ma thèse, j'ai comparé l'immunogénicité de l'antigène humain Melan A soit sous la forme d un LSP incluant un épitope CD4 et CD8 ou sous la forme d'un peptide ne contenant que l'épitope CD8 (SSP) Les peptides ont été formulés avec l'adjuvant QS21 et testés dans un modèle de souris transgéniques pour les MHC let II humains, respectivement le HLA-A2 et DR1. Les deux peptides LSP et SSP ont généré une forte réponse CD8 similaire assoc.ee a une capacité cytotoxique équivalente lors du transfert in vivo de cellules cibles présentant le peptide SSP' Cependant les souris immunisées avec le Melan A LSP présentaient un pourcentage plus élevé de CD8 ayant un Phénotype «centra, memory» (CD44h' CD62L+ and CCR7+ CD62L+) que les souris immunisées avec le SSP, même dix mois après I'immunisation. Par ailleurs, la réponse CD8 au Melan A LSP était strictement dépendante des lymphocytes CD4, contrairement à l'immunisation par le Melan A SSP qui n'était pas affectée. Dans l'ensemble ces résultats suggèrent que la chemokine XCL1 et l'adjuvant QS21 améliorent la réponse CD8 à un long peptide synthétique, favorisant ainsi le développement d'une réponse anti-tumeur mémoire durable. Ces observations pourraient être utiles au développement de nouveau vaccins thérapeutiques contre les tumeurs.

Combined CSL and p53 downregulation promotes cancer-associated fibroblast activation.

Stromal fibroblast senescence has been linked to ageing-associated cancer risk. However, density and proliferation of cancer-associated fibroblasts (CAFs) are frequently increased. Loss or downmodulation of the Notch effector CSL (also known as RBP-Jκ) in dermal fibroblasts is sufficient for CAF activation and ensuing keratinocyte-derived tumours. We report that CSL silencing induces senescence of primary fibroblasts from dermis, oral mucosa, breast and lung. CSL functions in these cells as a direct repressor of multiple senescence- and CAF-effector genes. It also physically interacts with p53, repressing its activity. CSL is downmodulated in stromal fibroblasts of premalignant skin actinic keratosis lesions and squamous cell carcinomas, whereas p53 expression and function are downmodulated only in the latter, with paracrine FGF signalling as the probable culprit. Concomitant loss of CSL and p53 overcomes fibroblast senescence, enhances expression of CAF effectors and promotes stromal and cancer cell expansion. The findings support a CAF activation-stromal co-evolution model under convergent CSL-p53 control.

A multistep process of cancer associated fibroblasts determination under CSL-p53 control

Stromal fibroblast senescence has been linked to the aging-associated increase of tumors. However, in epithelial cancer, density and proliferation of cancer associated fibroblasts (CAF) are frequently increased, rather than decreased. We previously showed that genetic deletion or down-modulation of the canonical Notch effector CSL/RBP-JK in dermal fibroblasts is sufficient for CAF activation with consequent development of keratinocyte-derived tumors. We show here that CSL silencing induces senescence of primary fibroblasts from dermis, oral mucosa, breast and lung. CSL functions in these cells as direct repressor of multiple senescence- and CAF-effector genes. It also physically interacts with p53, repressing its activity. CSL is down-modulated in stromal fibroblasts of premalignant skin actinic keratosis lesions and squamous cell carcinomas (SCC), while p53 gene expression and function is down-modulated only in the latter, with paracrine influences of incipient cancer cells as a likely culprit. Concomitant loss of CSL and p53 overcomes fibroblast senescence, enhances CAF effector gene expression and promotes stromal and cancer cell expansion. The findings support a CAF activation/stromal co-evolution model under convergent CSL/p53 control of likely clinical relevance.

Nrf2 Activation Promotes Keratinocyte Survival during Early Skin Carcinogenesis via Metabolic Alterations.

Pharmacologic activation of the transcription factor NRF2 has been suggested to offer a strategy for cancer prevention. In this study, we present evidence from murine tumorigenesis experiments suggesting there may be limitations to this possibility, based on tumorigenic effects of Nrf2 in murine keratinocytes that have not been described previously. In this setting, Nrf2 expression conferred metabolic alterations in keratinocytes that were protumorigenic in nature, affecting enzymes involved in glutathione biosynthesis or in the oxidative pentose phosphate pathway and other NADPH-producing enzymes. Under stress conditions, coordinate increases in NADPH, purine, and glutathione levels promoted the survival of keratinocytes harboring oncogenic mutations, thereby promoting tumor development. The protumorigenic activity of Nrf2 in keratinocytes was particularly significant in a mouse model of skin tumorigenesis that did not rely upon chemical carcinogenesis. In exploring the clinical relevance of our findings, we confirm that NRF2 and protumorigenic NRF2 target genes were activated in some actinic keratoses, the major precancerous lesion in human skin. Overall, our results reveal an unexpected tumor-promoting activity of activated NRF2 during early phases of skin tumorigenesis. Cancer Res; 75(22); 4817-29. ©2015 AACR.

Analysis of TRIP expression in different types of skin tumor

TRAF-interacting protein (TRIP) is a ubiquitously expressed nucleolar E3 ubiquitin ligase. Ubiquitination of proteins is a post-translational modification, which decides on the cellular fate of the protein. TRIP in vivo substrate has not been yet identified. However, TRIP has been shown to play an important role in cellular proliferation, especially in keratinocytes. TRIP was found to be up-regulated in basal cell carcinoma (BCC) at the mRNA level. This prompted us to elucidate its role in skin proliferative diseases such as cancer by analyzing its expression in BCCs at protein level and in squamous cell carcinoma (SCC) at mRNA and protein level. To that purpose, we performed a real-time PCR (qPCR) analysis followed by an immunohistochemistry (IHC) on formalin-fixed, paraffin-embedded (FFPE) biopsies. The real-time PCR was performed on 12 RNA samples of which 6 were extracted from SCC biopsies and 6 from normal human skin. The results were statistically insignificant. Further analyses are needed on new RNA samples. The IHC assay was performed on 20 biopsies from BCCs, 21 biopsies from SCCs and on 5 tissues from normal human skin. The results obtained showed an extensive expression of TRIP in keratinocytes nuclei. Due to various limitations related to the technique and to doubts about preservation of the antigens in the tissues from normal human skin, we could not highlight a clear difference in TRIP expression between the different tissues. In conclusion, further analyses are needed on new RNA samples (qPCR) and on better preserved FFPE tissues from normal skin (IHC) to assess TRIP relative expression in BCCs and SCCs versus normal human skin.

Oncobiguanides: Paracelsus" law and nonconventional routes for administering diabetobiguanides for cancer treatment

The dose makes the poison, the common motto of toxicology first expressed by Paracelsus more than 400 years ago, may effectively serve to guide potential applications for metformin and related biguanides in oncology. While Paracelsus' law for the dose-response effect has been commonly exploited for the use of some anti-cancer drugs at lower doses in non-neoplastic diseases (e.g., methotrexate), the opposite scenario also holds true; in other words, higher doses of non-oncology drugs, such as anti-diabetic biguanides, might exert direct anti-neoplastic effects. Here, we propose that, as for any drug, there is a dose range for biguanides that is without any effect, one corresponding to"diabetobiguanides" with a pharmacological effect (e.g., insulin sensitization in type 2 diabetes, prevention of insulin-dependent carcinogenesis, indirect inhibition of insulin and growth factor-dependent cancer growth) but with minimal toxicity and another corresponding to 'oncobiguanides' with pharmacological (i.e., direct and strong anticancer activity against cancer cells) as well as toxic effects. Considering that biguanides demonstrate a better safety profile than most oncology drugs in current use, we should contemplate the possibility of administering biguanides through non-conventional routes (e.g., inhaled for carcinomas of the lung, topical for skin cancers, intravenous as an adjunctive therapy, rectal suppositories for rectal cancer) to unambiguously investigate the therapeutic value of high-dose transient biguanide exposure in cancer. Perhaps then, the oncobiguanides, as we call them here, could be viewed as a mechanistically different type of anti-cancer drugs employed at doses notably higher than those used chronically when functioning as diabetobiguanides

Oestrogenic activity of benzyl salicylate, benzyl benzoate and butylphenylmethylpropional (Lilial) in MCF7 human breast cancer cells in vitro

Benzyl salicylate, benzyl benzoate and butylphenylmethylpropional (Lilial) are added to bodycare cosmetics used around the human breast. We report here that all three compounds possess oestrogenic activity in assays using the oestrogen-responsive MCF7 human breast cancer cell line. At 3 000 000-fold molar excess, they were able to partially displace [H-3]oestradiol from recombinant human oestrogen receptors ER alpha and ER beta, and from cytosolic ER of MCF7 cells. At concentrations in the range of 5 x 10(-5) to 5 x 10(-4) M, they were able to increase the expression of a stably integrated oestrogen-responsive reporter gene (ERE-CAT) and of the endogenous oestrogen-responsive pS2 gene in MCF7 cells, albeit to a lesser extent than with 10(-8) M 17 beta-oestradiol. They increased the proliferation of oestrogen-dependent MCF7 cells over 7 days, which could be inhibited by the antioestrogen fulvestrant, suggesting an ER-mediated mechanism. Although the extent of stimulation of proliferation over 7 days was lower with these compounds than with 10(-8) M 17 beta-oestradiol, given a longer time period of 35 days the extent of proliferation with 10(-4) M benzyl salicylate, benzyl benzoate or butylphenylmethylpropional increased to the same magnitude as observed with 10(-8) M 17 beta-oestradiol over 14 days. This demonstrates that benzyl salicylate, benzyl benzoate and butylphenylmethylpropional are further chemical components of cosmetic products which give oestrogenic responses in a human breast cancer cell line in culture. Further research is now needed to investigate whether oestrogenic responses are detectable using in vivo models and the extent to which these compounds might be absorbed through human skin and might enter human breast tissues. Copyright (C) 2009 John Wiley & Sons, Ltd.

Environmental oestrogens, cosmetics and breast cancer

The established role of oestrogen in the development and progression of breast cancer raises questions concerning a potential contribution from the many chemicals in the environment which can enter the human breast and which have oestrogenic activity. A range of organochlorine pesticides and polychlorinated bipheryls possess oestrogen-mimicking properties and have been measured in human breast adipose tissue and in human milk. These enter the breast from varied environmental contamination of food, water and air, and due to their lipophilic properties can accumulate in breast fat. However, it is emerging that the breast is also exposed to a range of oestrogenic chemicals applied as cosmetics to the underarm and breast area. These cosmetics are left on the skin in the appropriate area, allowing a more direct dermal absorption route for breast exposure to oestrogenic chemicals and allowing absorbed chemicals to escape systemic metabolism. This review considers evidence in support of a functional role for the combined interactions of cosmetic chemicals with environmental oestrogens, pharmacological oestrogens, phyto-oestrogens and physiological oestrogens in the rising incidence of breast cancer.

Endocrine disrupters and human health: Could oestrogenic chemicals in body care cosmetics adversely affect breast cancer incidence in women? A review of evidence and call for further research

In the decade that has elapsed since the suggestion that exposure of the foetal/developing male to environmental oestrogens could be the cause of subsequent reproductive and developmental effects in men, there has been little definitive research to provide conclusions to the hypothesis. Issues of exposure and low potency of environmental oestrogens may have reduced concerns. However, the hypothesis that chemicals applied in body care cosmetics (including moisturizers, creams, sprays or lotions applied to axilla or chest or breast areas) may be affecting breast cancer incidence in women presents a different case scenario, not least in the consideration of the exposure issues. The specific cosmetic type is not relevant but the chemical ingredients in the formulations and the application to the skin is important. The most common group of body care cosmetic formulation excipients, namely p-hydroxybenzoic acid esters or parabens, have been shown recently to be oestrogenic in vitro and in vivo and now have been detected in human breast tumour tissue, indicating absorption (route and causal associations have yet to be confirmed). The hypothesis for a link between oestrogenic ingredients in underarm and body care cosmetics and breast cancer is forwarded and reviewed here in terms of. data on exposure to body care cosmetics and parabens, including dermal absorption; paraben oestrogenicity; the role of oestrogen in breast cancer; detection of parabens in breast tumours; recent epidemiology studies of underarm cosmetics use and breast cancer; the toxicology database; the current regulatory status of parabens and regulatory toxicology data uncertainties. Notwithstanding the major public health issue of the causes of the rising incidence of breast cancer in women, this call for further research may provide the first evidence that environmental factors may be adversely affecting human health by endocrine disruption, because exposure to oestrogenic chemicals through application of body care products (unlike diffuse environmental chemical exposures) should be amenable to evaluation, quantification and control. The exposure issues are clear and the exposed population is large, and these factors should provide the necessary impetus to investigate this potential issue of public health. Copyright (C) 2004 John Wiley Sons, Ltd.

Growth of melanocytic cells is associated with down-regulation of protein kinase C α,δ and ε isoforms: Possible role of diacylglycerol

Protein kinase C (PKC) down-regulation has been shown to correlate with the growth of murine melanocytic cells in culture (Brooks, G., Wilson, R. E., Dooley, T. P., Goss, M. W., and Hart, I. R. (1991) Cancer Res. 51, 3281-3288). We now show that PKC alpha, delta, epsilon, and zeta isoforms are present at the protein level in quiescent, non-transformed Mel-ab melanocytes, maintained in the absence of phorbol ester. Proliferation of Mel-ab cells, achieved by incubation in the continual presence of phorbol 12,13-dibutyrate, was associated with a down-regulation of the PKC alpha, delta, and epsilon isozymes. Examination of two transformed syngeneic lines (the B16 murine melanoma and the long terminal repeat Ras.2 line), that grew in the absence of exogenous phorbol esters, showed that PKC alpha protein levels were either partially down-regulated or unaffected, the PKC delta and epsilon isoforms were down-regulated completely, and the levels of PKC zeta protein remained unaltered relative to quiescent Mel-ab cells. Basal levels of total diacylglycerol were elevated 5-fold in B16 melanoma cells compared with levels found in quiescent or proliferating Mel-ab melanocytes and appear to arise largely from the breakdown of phosphatidylinositol phospholipids accompanied by a significant rise in phospholipase C activity. Hourly treatments of quiescent Mel-ab melanocytes with the synthetic diacylglycerol analogue, 1,2-dioctanoyl-sn-glycerol, for 24 h, resulted in an induction of DNA synthesis which was associated with a significant down-regulation of PKC levels mediated largely via post-translational rather than transcriptional mechanisms. These results show for the first time that specific isoforms of PKC are down-regulated at the protein level during proliferation of murine melanocytic cells and suggest that the constitutive down-regulation of PKC in transformed melanoma cells may arise as a consequence of elevated endogenous phosphatidylinositol-derived diacylglycerol levels.

Feasibility of oncoplastic techniques in the surgical management of locally advanced breast cancer

Background: Locally advanced breast cancer (LABC) is still common in developing countries. The association between neoadjuvant chemotherapy (NC) and oncoplastic surgery (OS) might provide an oncological treatment with satisfactory aesthetic results.Purpose: The goal was to demonstrate if oncoplastic surgical techniques can be utilized to treat LABC which was submitted to neoadjuvant chemotherapy.Methods: This prospective clinical trial included breast cancer patients, clinical stage III, who underwent established NC regimen. All patients underwent preoperative planning to control the tumor size and to define the surgical technique. A detailed analysis of the pathological specimen was performed.Results: 50 patients were assessed and surgically treated. Tumor size ranged from 3.0 to 14.0 cm (median 6.5 cm). Pathologic response was rated as stable, progressive, partial response, and complete response in 10%, 8%, 80% and 2% of the cases, respectively. Seventeen (34%) patients were submitted to OS. No patient had positive margins. Skin involvement was presented in 36% of pathologic specimen.Conclusions: Oncoplastic surgical techniques for selected patients decrease the rates of radical surgery despite large tumors. (www.clinicaltrials.gov, NCT00820690). (C) 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Differential response related to genotoxicity between eggplant (Solanum melanogena) skin aqueous extract and its main purified anthocyanin (delphinidin) in vivo

Anthocyanins are the largest group of water-soluble pigments in the plant kingdom. A number of studies have demonstrated that anthocyanins present antioxidant capacity and show inhibitory effects on the growth of some cancer cells. Thus, the goal of this study was to evaluate both the antimutagenicity/antigenotoxicity and mutagenicity/genotoxicity of aqueous extract obtained from the Solanum melanogena, a possible novel source of anthocyanin, and its main purified anthocyanin extract (delphinidin), using the single cell (comet) assay and micronucleus test. Pretreatment with higher doses of the purified anthocyanin (10 and 20 mg/kg b.w.) led to a statistically significant reduction (p < 0.05) in the frequency of micronuclei in polychromatic erythrocytes induced by cyclophosphamide. The pattern of reduction ranged from 48% to 57% independent of concentration. No apparent: genotoxicity and mutagenicity was found for either the anthocyanin or delphinidin extracts. Taken together, these results suggest that mice pre-treated with specific compounds present in anthocyanins (delphinidin) displayed a lower incidence of mutations induced by cyclophosphamide. This finding emphasizes the potential of natural colorants to prevent mutations and also the applicability of genotoxic evaluation for improving health. Furthermore, the results presented here could be an additional argument to support the use of anthocyanins in the diet. (c) 2006 Published by Elsevier Ltd.