Body weight gain and control: beneficial effect of extra virgin olive oil versus corn oil in an experimental model of mammary cancer

Obesity is a known risk factor for breast cancer, the most common malignancy among women worldwide. We have previously described different effects of high-fat diets on mammary experimental carcinogenesis. In this work, we analyzed the animal growth data obtained in six experimental assays, in healthy and carcinogen-induced rats undergoing different dietary interventions. The animals were fed with three experimental diets administered at different periods of development: a control low-fat diet, and two isocaloric high-fat diets (rich in corn oil or in extravirgin olive oil -EVOO-). Weekly weight throughout the development of 818 animals have been compiled and reanalyzed using adjusted mathematical models. Molecular mechanisms have been investigated: ethanolamides in small intestine, neuropeptides controlling satiety in hypothalamus, and proteins controlling lipid metabolism in adipose and mammary tissues. The results indicated that the effect of diets depended on type of lipid, timing of intervention and health status. The high corn oil diet, but not the high EVOO diet, increased body weight and mass, especially if administered from weaning, in healthy animals and in those that received a moderate dose of carcinogen. The potential protective effect of EVOO on weight maintenance may be related to anorexigenic neuropeptides such as oxytocin and lipolysis/deposition balance in adipose tissue (increasing phospho-PKA, HSL, MGL and decreasing FAS). In animals with cancer, body weight gain was related to the severity of the disease. Taken together, our results suggest that EVOO has a beneficial effect on body weight maintenance in both health and cancer.

Extra-Virgin Olive Oil and Its Minor Compounds Influence Apoptosis in Experimental Mammary Tumors and Human Breast Cancer Cell Lines

Simple Summary

Breast cancer is a disease influenced by dietetic factors, such as the type and amount of lipids in a diet. In this work, we aimed to elucidate the different effects of two high-fat diets on the histopathological and molecular characteristics of mammary tumors in an experimental model. Animals fed with a diet high in extra-virgin olive oil (EVOO), compared to those fed with a diet high in seed oil, developed tumors with less aggressiveness and proliferation. Tumor molecular analyses of several cell death pathways also suggested an effect of EVOO in this process. In vitro experiments indicated the role of EVOO minor compounds on the effects of this oil. Obtaining insights into the influence and the mechanisms of action of dietary compounds are necessary to understand the relevance that dietetic habits from childhood may have on health and the risk of disease.

Abstract

Breast cancer is the most common malignancy among women worldwide. Modifiable factors such as nutrition have a role in its etiology. In experimental tumors, we have observed the differential influence of high-fat diets in metabolic pathways, suggesting a different balance in proliferation/apoptosis. In this work, we analyzed the effects of a diet high in n-6 polyunsaturated fatty acids (PUFA) and a diet high in extra-virgin olive oil (EVOO) on the histopathological features and different cell death pathways in the dimethylbenz(a)anthracene-induced breast cancer model. The diet high in n-6 PUFA had a stimulating effect on the morphological aggressiveness of tumors and their proliferation, while no significant differences were found in groups fed the EVOO-enriched diet in comparison to a low-fat control group. The high-EVOO diet induced modifications in proteins involved in several cell death pathways. In vitro analysis in different human breast cancer cell lines showed an effect of EVOO minor compounds (especially hydroxytyrosol), but not of fatty acids, decreasing viability while increasing apoptosis. The results suggest an effect of dietary lipids on tumor molecular contexts that result in the modulation of different pathways, highlighting the importance of apoptosis in the interplay of survival processes and how dietary habits may have an impact on breast cancer risk.

Influence of Olive Oil and Its Components on Breast Cancer: Molecular Mechanisms

Breast cancer is the most frequent malignant neoplasia and a leading cause of mortality in women worldwide. The Mediterranean diet has been proposed as a healthy dietary pattern with protective effects in several chronic diseases, including breast cancer. This diet is characterized by the consumption of abundant plant foods and olive oil as the principal source of fat, which is considered one of the main components with potential antioxidant, anti-inflammatory and anticancer effects. Extra-virgin olive oil (EVOO) has several bioactive compounds, mainly including monounsaturated fatty acids, triterpenes and polyphenols, such as phenolic alcohols (e.g., hydroxytyrosol), secoiridoids (e.g., oleuropein and oleocanthal), lignans (e.g., pinoresinol) or flavonoids (e.g., luteolin). While epidemiological evidence is still limited, experimental in vivo and in vitro data have shown a protective effect of this oil and its compounds on mammary carcinogenesis. Such effects account through complex and multiple mechanisms, including changes in epigenetics, transcriptome and protein expression that modulate several signaling pathways. Molecular targets of EVOO compounds have a role in the acquisition of cancer hallmarks. Although further research is needed to elucidate their beneficial effects on human prevention and progression of the disease, evidence points to EVOO in the context of the Mediterranean diet as a heathy choice, while EVOO components may be promising adjuvants in anticancer strategies.

A high extra-virgin olive oil diet induces changes in metabolic pathways of experimental mammary tumors

Breast cancer is the most common malignancy in women worldwide, and environmental factors, especially diet, have a role in the etiology of this disease. This work aimed to investigate the influence of high fat diets (rich in corn oil or extra virgin olive oil -EVOO-) and the timing of dietary intervention (from weaning or after induction) on tumor metabolism in a 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer model in rat. The effects of lipids (oils and fatty acids) have also been investigated in MCF-7 cells. The results have confirmed different effects on tumor progression depending on the type of lipid. Molecular analysis at mRNA, protein and activity level of enzymes of the main metabolic pathways have also shown differences among groups. Thus, the animals fed with the EVOO-enriched diet developed tumors with less degree of clinical and morphological malignancy and showed modified glucose and mitochondrial metabolism when compared to the animals fed with the corn oil-enriched diet. Paradoxically, no clear influence on lipid metabolism by the high fat diets was observed. Considering previous studies on proliferation and apoptosis in the same samples, the results suggest that metabolic changes have a role in the molecular context that results in the modulation of different signaling pathways. Moreover, metabolic characteristics, without the context of other pathways, may not reflect tumor malignancy. The time of dietary intervention plays also a role, suggesting the importance of metabolic plasticity and the relation with mammary gland status when the tumor is induced.

Antioxidant, anti-inflammatory and cytotoxic activities of the unsaponifiable fraction of extra virgin olive oil

The health benefits of olive oil are well-known. In this study, the unsaponifiable fraction of extra virgin olive oil (Unsap) was investigated for reducing power capacity, ferric reducing antioxidant power, fer-rous chelating activity and nitric oxide inhibition. The present study was also designed to evaluate the in vitro cytotoxic effect of the Unsap against human carcinoma cells. The anti-inflammatory potential of Unsap has been determined via the inhibition of Human Cyclooxygenases. The results showed that Unsap is efficient for ferric reducing antioxidant power and nitric oxide inhibition. Unsap has a selective effect as anti-inflammatory agent. The results showed moderate to good in vitro antitumor activities of Unsap against human liver, lung and pancreas cancer cells with IC50 ranging from 19.6 to 30.4 μg/mL and good selectivity index (≥ 2). In conclusion, Unsap represents a promising and safe antitumor and antioxidant material that supports the need for further investigation.

Effects of diets high in corn oil or in extra virgin olive oil on oxidative stress in an experimental model of breast cancer

Experimental evidence highlights the importance of dietetic factors on breast cancer. In this work we aimed to analyze the effects two oils, corn oil (rich in n-6 polyunsaturated fatty acids -PUFA-) and extra virgin olive oil (EVOO), on oxidative stress in an animal model of breast carcinogenesis. Female rats were fed a low-fat control, a high-corn oil, or a high-EVOO diet from weaning or after induction with 7,12-dimethylbenz[a]anthracene at 53 days. Animals were euthanized at 36, 51, 100 and 246 days of age. We analyzed antioxidant enzymes (mRNA and activity of superoxide dismutase, glutathione peroxidase and catalase), non-enzymatic capacity (oxidized and reduced glutathione) and DNA damage (8-oxo-dG) in tumors and mammary gland at different ages. We also analyzed lipid peroxidation (isoprostanes in serum and lipofuscin in liver). Results indicated a decrease in the enzymatic antioxidant capacity and increased oxidative stress in mammary gland of healthy young animals after a short period of high-fat diets intake, followed by an adaptation to chronic dietary intervention. After induction both diets, especially the one high in n-6 PUFA, increased the oxidized glutathione. In tumors no clear effects of the high-fat diets were observed, although in the long-term lipofuscin and 8-oxo-dG suggested greater oxidative damage by effect of the n-6 PUFA-rich diet. Considering the differential effects of these diets on mammary carcinogenesis that we have previously reported, this study suggests that these high-fat diets could have an effect on oxidative stress that would lead to different signaling pathways.

Gene pathways associated with mitochondrial function, oxidative stress and telomere length are differentially expressed in the liver of rats fed lifelong on virgin olive, sunflower or fish oils

This study investigates the effect of lifelong intake of different fat sources rich in monounsaturated (virgin olive oil), n6 polyunsaturated (sunflower oil) or n3 polyunsaturated (fish oil) fatty acids in the aged liver. Male Wistar rats fed lifelong on diets differing in the fat source were killed at 6 and at 24 months of age. Liver histopathology, mitochondrial ultrastructure, biogenesis, oxidative stress, mitochondrial electron transport chain, relative telomere length and gene expression profiles were studied. Aging led to lipid accumulation in the liver. Virgin olive oil led to the lowest oxidation and ultrastructural alterations. Sunflower oil induced fibrosis, ultrastructural alterations and high oxidation. Fish oil intensified oxidation associated with age, lowered electron transport chain activity and enhanced the relative telomere length. Gene expression changes associated with age in animals fed virgin olive oil and fish oil were related mostly to mitochondrial function and oxidative stress pathways, followed by cell cycle and telomere length control. Sunflower oil avoided gene expression changes related to age. According to the results, virgin olive oil might be considered the dietary fat source that best preserves the liver during the aging process.

Dietary lipids differentially modulate the initiation of experimental breast carcinogenesis through their influence on hepatic xenobiotic metabolism and DNA damage in the mammary gland

Breast cancer is the most common malignancy among women worldwide. In addition to reproductive factors, environmental factors such as nutrition and xenobiotic exposure have a role in the etiology of this malignancy. A stimulating and a potentially protective effect on experimental breast cancer has been previously described for high corn oil and high extra-virgin olive oil diets, respectively. This work investigates the effect of these lipids on the metabolism of 7,12-dimethylbenz(a)anthracene (DMBA), a polycyclic aromatic hydrocarbon that can initiate carcinogenesis and its consequences in an experimental rat breast cancer model. The PUFA n-6-enriched diet increased expression of Phase I enzymes prior to DMBA administration and raised the activity of CYP1s in the hours immediately after induction, while reducing the activity of Phase II enzymes, mainly NQO1. The levels of reactive metabolites measured in plasma by GC-MS and DMBA-DNA adducts in the mammary gland of the animals fed the high corn oil diet were also higher than in the other groups. On the other hand, the high extra-virgin olive oil diet and the control low-fat diet exhibited better coordinated Phase I and Phase II activity, with a lower production of reactive metabolites and less DNA damage in the mammary gland. The concordance between these effects and the different efficacy of the carcinogenesis process due to the dietary treatment suggest that lipids may differently modify mammary gland susceptibility or resistance to cancer initiation over the exposure to environmental carcinogens.

SUMMARY

Dietary lipids influence the initiation of DMBA-induced mammary cancer through the modulation of liver xenobiotic metabolism, formation of reactive metabolites and subsequent DNA damage in the target tissue.

Extra Virgin Olive Oil Improves Oxidative Stress, Functional Capacity, and Health-Related Psychological Status in Patients With Fibromyalgia: A Preliminary Study

OBJECTIVES

Fibromyalgia (FM) is a chronic disease that imposes physical, psychological, and social limitations. We have reported that oxidative stress may play a role in the pathophysiology of FM. Olive oil has been shown to be effective treatment against the oxidative stress associated with several diseases. The aim of this study was to investigate the effect of olive oil on oxidative stress and health-related parameters in FM.

METHODS

This preliminary study was performed on blood samples of 23 women diagnosed with FM who consumed 50 ml of organic olive oil daily for 3 weeks. Subjects were randomized into two groups: one ingested extra virgin olive oil (EVOO) and the other refined olive oil (ROO), which have different antioxidant content. The patients' oxidative (lipid, protein, and DNA oxidation) and antioxidative (antioxidant enzyme activities and compounds) profiles were examined before and after the treatment period. Functional capacity and physical and mental health status were assessed using the Fibromyalgia Impact Questionnaire (FIQ) and the Physical Component (PCS-12) and Mental Component Summaries (MCS-12) of the Short Form-12 Health Survey, respectively.

RESULTS

Significant differences were found in pre-post change between the EVOO and ROO groups for protein carbonyls, lipid peroxidation, and FIQ and MCS-12 scores. Differences between groups approached statistical significance for oxidative DNA damage and levels of the antioxidant compound zinc.

CONCLUSIONS

EVOO may protect women with FM against oxidative stress in addition to improving functional capacity and health-related psychological status. Findings suggest that olive oil may be a valuable therapeutic support in FM.

Molecular Profiling and Malignant Behavior Define Two Rat Mammary Tumor Cell Lines as a Relevant Experimental Model

Cancer cell lines have become a reliable tool in genetic and biochemical studies of breast cancer. Here, we described the behavior and novel molecular characterization of two cell lines derived from DMBA-induced rat mammary tumor, LA7 and RBA. LA7 cells have been identified as myoepithelial cells with stem cell properties, whereas the RBA cell line are epithelial cells that present mutational activated H-Ras, but are much less known. We evaluated the proliferation rate and molecular markers, several signaling pathways status related to proliferation, survival, inflammation, and apoptosis, as well as migration capacity, global DNA methylation levels, and stem cells populations. In fact, we found the A/T transversion in the c-Ha-Ras codon 61 as the activator mutation origin described in RBA cells. LA7 and RBA cells showed a high proliferation rate associated with overexpression of Cyclin D1, and resistance to apoptotic signals due to lack of expression of Bad. Moreover, neither of these two cell lines expressed steroid receptors, but they showed high migration capacity, all in accordance with an aggressive phenotype. We found global DNA methylation levels in LA7 and RBA cells lower than reference tissues analyzed, in addition to the presence of different stem cells populations in RBA cell line that differed in the expression of CD44 and CD24. These results revealed a malignant behavior associated with cancer stem cell phenotype. Since this profile is similar to a human triple-negative basal-like tumor, their extensive characterization presented herein increases their value as a good in vitro model. J. Cell. Biochem. 117: 2825-2834, 2016. © 2016 Wiley Periodicals, Inc.

The Role of Dietary Extra Virgin Olive Oil and Corn Oil on the Alteration of Epigenetic Patterns in the Rat DMBA-Induced Breast Cancer Model

Disruption of epigenetic patterns is a major change occurring in all types of cancers. Such alterations are characterized by global DNA hypomethylation, gene-promoter hypermethylation and aberrant histone modifications, and may be modified by environment. Nutritional factors, and especially dietary lipids, have a role in the etiology of breast cancer. Thus, we aimed to analyze the influence of different high fat diets on DNA methylation and histone modifications in the rat dimethylbenz(a)anthracene (DMBA)-induced breast cancer model. Female Sprague-Dawley rats were fed a low-fat, a high corn-oil or a high extra-virgin olive oil (EVOO) diet from weaning or from induction with DMBA. In mammary glands and tumors we analyzed global and gene specific (RASSF1A, TIMP3) DNA methylation by LUMA and bisulfite pyrosequencing assays, respectively. We also determined gene expression and enzymatic activity of DNA methyltransferases (DNMT1, DNMT3a and DNMT3b) and evaluated changes in histone modifications (H3K4me2, H3K27me3, H4K20me3 and H4K16ac) by western-blot. Our results showed variations along time in the global DNA methylation of the mammary gland displaying decreases at puberty and with aging. The olive oil-enriched diet, on the one hand, increased the levels of global DNA methylation in mammary gland and tumor, and on the other, changed histone modifications patterns. The corn oil-enriched diet increased DNA methyltransferase activity in both tissues, resulting in an increase in the promoter methylation of the tumor suppressor genes RASSF1A and TIMP3. These results suggest a differential effect of the high fat diets on epigenetic patterns with a relevant role in the neoplastic transformation, which could be one of the mechanisms of their differential promoter effect, clearly stimulating for the high corn-oil diet and with a weaker influence for the high EVOO diet, on breast cancer progression.

Diets high in corn oil or extra-virgin olive oil differentially modify the gene expression profile of the mammary gland and influence experimental breast cancer susceptibility

PURPOSE

Nutritional factors, especially dietary lipids, may have a role in the etiology of breast cancer. We aimed to analyze the effects of high-fat diets on the susceptibility of the mammary gland to experimental malignant transformation.

METHODS

Female Sprague-Dawley rats were fed a low-fat, high-corn-oil, or high-extra-virgin olive oil (EVOO) diet from weaning or from induction. Animals were induced with 7,12-dimethylbenz[a]anthracene at 53 days and euthanized at 36, 51, 100 and 246 days. Gene expression profiles of mammary glands were determined by microarrays. Further molecular analyses were performed by real-time PCR, TUNEL and immunohistochemistry. Carcinogenesis parameters were determined at 105 and 246 days.

RESULTS

High-corn-oil diet increased body weight and mass when administered from weaning. The EVOO diet did not modify these parameters and increased the hepatic expression of UCP2, suggesting a decrease in intake/expenditure balance. Both diets differentially modified the gene expression profile of the mammary gland, especially after short dietary intervention. Corn oil down-regulated the expression of genes related to immune system and apoptosis, whereas EVOO modified the expression of metabolism genes. Further analysis suggested an increase in proliferation and lower apoptosis in the mammary glands by effect of the high-corn-oil diet, which may be one of the mechanisms of its clear stimulating effect on carcinogenesis.

CONCLUSIONS

The high-corn-oil diet strongly stimulates mammary tumorigenesis in association with modifications in the expression profile and an increased proliferation/apoptosis balance of the mammary gland.

Anti-breast Cancer Agents Derived from Plants

Upon emergence of modern anticancer therapy, medical community is divided into two opposite camps, one of them claiming absolute necessity of using isolated or synthesized chemical compounds for efficient patient treatment and another one advocating alternative cancer therapies, in particular those based on natural sources, including extracts from plants. It seems, in reality, that the two camps are reconcilable: while natural sources, plant extracts or juices play both curative and protective role, drugs represent the ultimate possibility to inhibit or reverse tumor development. In this paper we tried to analyze anti-breast cancer potencies of quite a few extracts from different plant sources and to compare their anti-proliferative efficiency of crude extracts with actions of their purified ingredients.

Mechanisms involved in the antiproliferative and proapoptotic effects of unsaponifiable fraction of extra virgin olive oil on HT-29 cancer cells

Extra virgin olive oil (EVOO) has demonstrated great oncostatic and antiinflammatory properties. Nowadays, it is clear that unsaponifiable fraction (UF) as well as other minor EVOO components have a key role in these beneficial effects. The present study was designed to evaluate UF effect in HT-29 human colon adenocarcinoma cells. Cell growth and viability assays were determined by sulphorhodamine B test at different time points (24, 48, and 72 h). The proapoptotic effect was evaluated by flow cytometric studies and different protein expression were determined by immunoblotting. UF μg/mL concentrations' range significantly reduced the growth of HT-29 cell line. Moreover UF induced intrinsic apoptotic pathway in HT-29 human colon adenocarcinoma cells through PPARγ and NFκB signaling pathways coming up to COX-2 downregulation and modulating p53 suppressor protein levels. The results suggest that UF of EVOO may exert an important role in the anticancer effect of EVOO and provide a natural resource for the prevention or treatment of human colon cancer.

Olive oil and other dietary lipids in breast cancer

Breast cancer is the most frequent malignant neoplasia among women worldwide. In addition to genetic and endocrine factors, the environment, and specifically nutritional factors, plays a key role in its aetiology. Epidemiological and in particular experimental studies have shown the link between dietary fat and breast cancer. Abundant data have attributed a potentially chemopreventive effect for extra-virgin olive oil (EVOO), the main source of fat in the Mediterranean diet, which is associated with low incidence and mortality rates from chronic diseases such as breast cancer. We have demonstrated the differential modulatory effect of dietary lipids on mammary carcinogenesis, mainly in studies developed in an experimental model. Thus, diets high in n-6 polyunsaturated fatty acids (PUFA) have a clear stimulating influence, whereas EVOO diets mainly have a negative modulatory effect on breast cancer development. The specific mechanisms involved are not fully understood, but nowadays, it is widely accepted that they are numerous and complex. Our group has contributed to improving the knowledge of these mechanisms by demonstrating the influence of dietary lipids on the structure and function of cell membranes, the modulation of cell-signalling transduction pathways, the regulation of gene expression and growth and sexual maturity.

Phenols of virgin olive oil protects nuclear DNA against oxidative damage in HeLa cells

Oxidative DNA damage is an inescapable consequence for cells constantly exposed to oxidative stress derived from normal metabolic processes and from environmental factors. Phenolic compounds, which have strong antioxidant activity, prevent DNA damage by protecting the cells against harmful effects of oxidative stress. In this study, the effect of virgin olive oil phenolic extract (OOPE) was investigated on H2O2-induced mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) damage in HeLa cells. DNA damage was assessed in mitochondria and two nuclear regions by using quantitative PCR (QPCR) assay. The cells were pre-treated with non-cytotoxic doses of OOPE for 4 h, and DNA damage was determined. OOPE alone does not change the steady-state level of DNA damage. The oxidative stress generated with 750 μM H2O2 caused two times greater damages in mtDNA compared to nDNA, which included the nonexpressed β-globin region (1.507±0.110 lesions/10 kb) and the expressed APEX1 gene (1.623±0.243 lesions/10 kb) with respect to the control region. When cells were preincubated with OOPE for 4 h, nDNA damage under stress condition was completely inhibited; however, mtDNA damage was not affected by this procedure. These results suggest that OOPE has a protective effect against nDNA damage in HeLa cells.

Olive oil, an essential component of the Mediterranean diet, and breast cancer

Objective

The Mediterranean diet has been related to a lower risk of some chronic diseases, including cancer. We aim to gain insight into the effects of the main source of fat of this diet on breast cancer, the most common type of malignancy in women.

Design

Data from sixteen experimental series analysing the effects of dietary lipids on mammary carcinogenesis in an animal model, in the context of the international literature on the Mediterranean diet, olive oil and breast cancer risk.

Setting

Experimental and human data on the effects of olive oil and Mediterranean diet on breast cancer.

Subjects

An animal model of induced breast cancer and other human and experimental studies in the literature.

Results

Diets rich in extra virgin olive oil (EVOO) exert a negative modulatory effect on experimental breast cancer to a weak promoting effect, much lower than that obtained with a high-corn oil diet. EVOO confers to the mammary adenocarcinomas a clinical behaviour and morphological features compatible with low tumour aggressiveness. This differential effect, in relation to other dietary lipids, may be related to a lower effect on body weight and sexual maturation. In addition, EVOO induced different molecular changes in tumours, such as in the composition of cell membranes, activity of signalling proteins and gene expression. All these modifications could induce lower proliferation, higher apoptosis and lower DNA damage. These results, together with the favourable effect of olive oil reported in the literature when it is consumed in moderate quantities, suggest a beneficial influence of EVOO on breast cancer risk.

Conclusions

Consumption of EVOO in moderate quantities and throughout the lifetime appears to be a healthy choice and may favourably influence breast cancer risk.

High expressions of bcl-2 and survivin, and decreased apoptosis in uterine cervical carcinosarcoma compared to cervical squamous cell carcinoma

PURPOSES

Uterine cervical carcinosarcoma (CS) is very rare. To date, only 40 cases have been reported. It seems to have a more aggressive clinical behavior than does cervical squamous cell carcinoma (SCC). The purposes of our study were to characterize the clinicopathologic characteristics and human papillomavirus (HPV) status of the rare tumor and to analyze the molecular features in cervical CS that may account for its aggressive behavior.

METHODS

Three patients were diagnosed with uterine cervical CS at West China Second Hospital of Sichuan University between 1995 and 2009. Data were retrospectively analyzed from available charts and pathological reports. Twelve patients with FIGO stage Ib-IIa cervical SCC were enrolled as the controls, and the expression profiling of p53, Ki-67, bcl-2, survivin and apoptosis index between cervical CS and SCC was compared. Immunohistochemical and apoptosis results were scored separately for the carcinomatous and sarcomatous components.

RESULTS

All three patients were shown to be negative for HPV infection by Hybribio HPV genoarray assay. Expression of p53 was observed in one patient in both carcinomatous and sarcomatous components in a similar proportion; in contrast, the Ki67, bcl-2 and survivin expressions were higher in carcinomatous components than in sarcomatous components in all three cases. Compared to cervical SCC, stronger immunostaining for bcl-2, survivin and lower apoptosis was observed in cervical CS.

CONCLUSIONS

Cervical CS is a peculiar tumor with many different clinicopathologic characteristics from cervical SCC. Dysregulation of apoptosis may confer tumor cells of cervical CS with survival and growth advantages, and thereby facilitate the aggressive behavior of cervical CS.

Aggressive mammary carcinoma progression in Nrf2 knockout mice treated with 7,12-dimethylbenz[a]anthracene

Background

Activation of nuclear factor erythroid 2-related factor (Nrf2), which belongs to the basic leucine zipper transcription factor family, is a strategy for cancer chemopreventive phytochemicals. It is an important regulator of genes induced by oxidative stress, such as glutathione S-transferases, heme oxygenase-1 and peroxiredoxin 1, by activating the antioxidant response element (ARE). We hypothesized that (1) the citrus coumarin auraptene may suppress premalignant mammary lesions via activation of Nrf2/ARE, and (2) that Nrf2 knockout (KO) mice would be more susceptible to mammary carcinogenesis.

Methods

Premalignant lesions and mammary carcinomas were induced by medroxyprogesterone acetate and 7,12-dimethylbenz[a]anthracene treatment. The 10-week pre-malignant study was performed in which 8 groups of 10 each female wild-type (WT) and KO mice were fed either control diet or diets containing auraptene (500 ppm). A carcinogenesis study was also conducted in KO vs. WT mice (n = 30-34). Comparisons between groups were evaluated using ANOVA and Kaplan-Meier Survival statistics, and the Mann-Whitney U-test.

Results

All mice treated with carcinogen exhibited premalignant lesions but there were no differences by genotype or diet. In the KO mice, there was a dramatic increase in mammary carcinoma growth rate, size, and weight. Although there was no difference in overall survival, the KO mice had significantly lower mammary tumor-free survival. Also, in the KO mammary carcinomas, the active forms of NF-κB and β-catenin were increased ~2-fold whereas no differences in oxidized proteins were observed. Many other tumors were observed, including lymphomas. Interestingly, the incidences of lung adenomas in the KO mice were significantly higher than in the WT mice.

Conclusions

We report, for the first time, that there was no apparent difference in the formation of premalignant lesions, but rather, the KO mice exhibited rapid, aggressive mammary carcinoma progression.