Male reproductive system and antioxidants in oxidative stress induced by hypobaric hypoxia.

In Chile, due to the intensive activity developed in confining areas of the Andes Mountains ranging in altitude over 4000 asl, there has been an increasing intermittent movement of human resources to high altitude conditions. This unusual condition, defined as hypobaric hypoxia, affects notoriously in any living organism and there shows a series of physiological responses. Studies performed in rats under chronic hypobaric hypoxia and intermittent hypobaric hypoxia have registered changes in testicular morphology together with loss of spermatogenic cells in all stages of spermatogenic cycle. Furthermore, recent tests reinforced the existence of an oxidative metabolism in epididymis of rats subjected to hypobaric hypoxia due to the increase in the regulator enzyme expression of reactive oxygen species (ROS), This increase in the production of ROS induced a rise in apoptosis at germinal cell level, leading to a state of hypo-spermatogenesis that may jeopardise masculine fertility. Therefore, the eventual development of oxidative stress in spermatogenic cells and consequently the spermatozoids of workers subjected to high altitude, either chronic or intermittent, turns out to be critical when it poses as an imminent risk to the viability and quality of the reproductive cells of workers subjected to intermittent hypobaric hypoxia.

Blueberries prevent the effect of intermittent hypobaric hypoxia in rat epididymis.

Intermittent hypobaric hypoxia (IHH) induced a decrease in sperm count and oxidative damage in epididymis. We have previously demonstrated that a blueberry-enriched polyphenol extract (BB-4) reduced the adverse effects of oxidative stress in rat testis under hypobaric hypoxia. The aim of this study was to evaluate whether BB-4 could reverse oxidative stress in epididymis. To evaluate the protective role of BB-4 in epididymis, male rats were exposed to IHH. Lipid peroxidation, (LPO) expression and activity of glutathione reductase (GR) were evaluated. Our results showed a reduction in LPO and a decrease in GR activity in rat epididymis exposed to IHH. These results suggest that BB-4 can prevent the effects of IHH in rat epididymis.

Radiation-induced non-targeted response in vivo: role of the TGFß-TGFBR1-COX-2 signalling pathway.

BACKGROUND: Previous studies from our group and others have shown that cyclooxygenase-2 (COX-2) has an essential role in radiation-induced non-targeted responses and genomic instability in vivo. However, the signalling pathways involved in such effects remain unclear. METHODS: A 1 cm(2) area (1 cm × 1 cm) in the lower abdominal region of gpt delta transgenic mice was irradiated with 5 Gy of 300 keV X-rays. Nimesulide, a selective COX-2 inhibitor, was given to mice for five consecutive days before irradiation. Changes in transforming growth factor-beta (TGF-ß) and TGF-ß receptor type-1 (TGFBR1) mediated signalling pathways, in the out of radiation field lung and liver tissues were examined. RESULTS: While the plasma level of cytokines remained unchanged, the expression of TGF-ß and its receptors was elevated in non-targeted lung tissues after partial body irradiation. In contrast to the predominant expression of TGF-ß in stromal and alveolar cells, but not in bronchial epithelial cells, TGF-ß receptors, especially TGFBR1 were significantly elevated in non-targeted bronchial epithelial cells, which is consistent with the induction of COX-2. The different expression levels of TGFBR1 between liver and lung resulted in a tissue specific induction of COX-2 in these two non-targeted tissues. Multiple TGF-ß induced signalling pathways were activated in the non-targeted lung tissues. CONCLUSION: The TGFß-TGFBR1-COX-2 Signalling Pathway has a critical role in radiation-induced non-targeted response in vivo.

Radiation induced COX-2 expression and mutagenesis at non-targeted lung tissues of gpt delta transgenic mice.

BACKGROUND: Although radiation-induced bystander effects have been confirmed using a variety of endpoints, the mechanism(s) underlying these effects are not well understood, especially for in vivo study. METHODS: A 1-cm(2) area (1 cm × 1 cm) in the lower abdominal region of gpt delta transgenic mice was irradiated with 5 Gy of 300 keV X-rays, and changes in out-of-field lung and liver were observed. RESULTS: Compared with sham-treated controls, the Spi(-) mutation frequency increased 2.4-fold in non-targeted lung tissues at 24 h after partial body irradiation (PBIR). Consistent with dramatic Cyclooxygenase 2 (COX-2) induction in the non-targeted bronchial epithelial cells, increasing levels of prostaglandin, together with 8-hydroxydeoxyguanosine, in the out-of-field lung tissues were observed after PBIR. In addition, DNA double-strand breaks and apoptosis were induced in bystander lung tissues after PBIR. CONCLUSION: The PBIR induces DNA damage and mutagenesis in non-targeted lung tissues, especially in bronchial epithelial cells, and COX-2 has an essential role in bystander mutagenesis.

The stemness phenotype model.

The identification of a fraction of cancer stem cells (CSCs) associated with resistance to chemotherapy in most solid tumors leads to the dogma that eliminating this fraction will cure cancer. Experimental data has challenged this simplistic and optimistic model. Opposite to the classical cancer stem cell model, we introduced the stemness phenotype model (SPM), which proposed that all glioma cells possess stem cell properties and that the stemness is modulated by the microenvironment. A key prediction of the SPM is that to cure gliomas all gliomas cells (CSCs and non-CSCs) should be eliminated at once. Other theories closely resembling the SPM and its predictions have recently been proposed, suggesting that the SPM may be a useful model for other type of tumors. Here, we review data from other tumors that strongly support the concepts of the SPM applied to gliomas. We include data related to: (1) the presence of a rare but constant fraction of CSCs in established cancer cell lines, (2) the clonal origin of cancer, (3) the symmetrical division, (4) the ability of "non-CSCs" to generate "CSCs," and (5) the effect of the microenvironment on cancer stemness. The aforenamed issues that decisively supported the SPM proposed for gliomas can also be applied to breast, lung, prostate cancer, and melanoma and perhaps other tumors in general. If the glioma SPM is correct and can be extrapolated to other types of cancer, it will have profound implications in the development of novel modalities for cancer treatment.

Metastatic suppressor CD44 is related with oxidative stress in breast cancer cell lines.

Evidence has accumulated on the role of reactive oxygen species (ROS) in metastasis since surgical removal of tumors generates oxidative stress promoting metastasis and cell growth. Metastasis consists of a cascade of events which allow the cell to survive in target tissues and influence several processes such as dissemination from tumor tissue, transport in blood/lymphatic vessels, invasion and homing of malignant cells. A cDNA oligoarray was used to determine whether alterations of metastatic genes are associated with oxidative stress in breast cancer cell lines. The cell lines used for the experiments were derived from a pre-existent in vitro breast cancer progression model originated in our laboratory. The cDNA array showed alterations in functional gene groups related with cell-cell and cell-matrix interaction molecules, such as caveolin-1; metastasis suppressor genes, such as CD44; metastasis-associated proteases, such as cathepsin D and the protease inhibitor, plasminogen activator inhibitor type 1. The changes of the selected genes were validated by differential display-RT-PCR as well as by protein expression assessed by Western blot analysis. It was found that the cell line, called Tumor2 with down-regulation of basal ROS and manganese superoxide dismutase (MnSOD) expression as a constitutive pattern of this cell line, presented alterations in genes that confer metastatic potential in comparison to the Alpha5 cell line, showing overexpression of basal MnSOD and high levels of ROS. Interesting, it was to found that CD44, considered a metastatic suppressor gene, was influenced by ROS, measured by hydrogen peroxide treatments, as seen by decreased CD44 protein expression in the Alpha5 cell line in a compensatory response to increased MnSOD protein expression. In conclusion, alterations of metastatic genes in malignant breast cancer cell lines were observed in relation to ROS and basal levels of antioxidant enzymes.

Profiling of cell cycle genes of breast cells exposed to etodolac.

Breast cancer represents the second leading cause of cancer-related deaths in the world. There is increasing evidence that perturbation of cell cycle regulation is an important contributing factor to various cancer progression stages. There are key checkpoints in the cell cycle involving various regulatory proteins. The relationship between these cell cycle regulatory proteins and cell cycle arrest by cyclo-oxygenase (COX) inhibitors during neoplastic progression remains largely unknown. Preclinical studies and epidemiological investigations have consistently shown that non-steroidal anti-inflammatory drugs have some anti-proliferative and anti-oxidative stress response on various tumors. In this study, the effect of etodolac, a 1,8-diethyl-1,3,4,9-tetrahydro-pyrano (3,4-beta) indole-1-acetic acid on signaling pathways was investigated by examining the differential expression of various cell cycle regulatory protein genes. A human cell cycle gene array was used to profile the expression of 96 genes involved in the cell cycle regulation. Differentially expressed genes were highly altered by etodolac treatment. Twenty-six genes were up- and 20 down-regulated with 0.5 and 2 mM etodolac treatment, respectively. Seven genes (ATM, BAX, CCNA2, CDC27, RAD50 and p21) were prominently altered, and six (ATM, CCND2, CCNF, CDC20, CDK1A and RAD50) were commonly altered with both concentrations. This finding indicated that etodolac could play a critical role on cancer cells by inducing cell death.

Phosphoproteomic profiling of arsenite-treated human small airway epithelial cells.

Arsenic is well documented as a chemotherapeutic agent capable of inducing cell death; however, it is also considered as a human carcinogen. Although it has recently been shown that arsenite exposure can potentiate genotoxicity, little is known about its global effects exerted in cells at the proteome level. Immortalized human small airway epithelial cells exposed to arsenite were used to identify phosphoproteins of two major signaling cascades, such as the human phospho-receptor tyrosine kinase (Phospho-RTK) and the mitogen-activated protein kinases (MAPKs). These two arrays included several phosphoproteins, such as EGFR, ErbB2, ErbB4, InsulinR, Flt-3, extracellular signal-regulated kinases (ERK1/2), intracellular kinases such as AKT, GSK-3, c-Jun N-terminal kinases (JNK1-3) and different p38 isoforms (alpha/beta/delta/gamma). In arsenite-treated cells, phosphorylation of EGFR, InsulinR and Flt3R showed an increase when compared to their non-arsenite treated counterparts. Inhibitors of these proteins further confirmed the involvement of such proteins in the neoplasm transformation of arsenite-treated human small airway epithelial cells as seen in changes in plating efficiency, anchorage-independent growth and proliferation rate. It can be concluded that analysis of phosphoprotein by using phosphoproteomic profiling can be very useful to understand the mechanism of arsenite-induced carcinogenesis.

Presence of prostate cells in bone marrow biopsies as a sign of micrometastasis in cancer patients.

The presence of prostate cancer cells in bone marrow of patients with clinically localized disease is associated with increased chance of disease recurrence. The presence of prostate specific antigen (PSA) in bone marrow aspirates has been used to indicate the presence of micrometastasis. The aim of this study was to present a prospective study of prostate cancer patients to determine the presence of cells that express PSA in aspirates taken from bone marrow and to compare with bone marrow biopsy samples. Results indicated a significant difference between the frequency of cells detected in bone marrow aspirate and biopsy samples (P<0.0002) when all patients were considered. There was no difference between the frequencies of cells detected in bone marrow aspirate and biopsy of patients analyzed before treatment. However, there was a significant (P<0.003) difference between them after treatment. There was also a significant difference in the frequency of PSA positive cells detected (P<0.005) in Stages I to IV as well as in the frequency of cells detected (P<0.0002) when analyzed according to Gleason score. The present results explain the lack of correlation between positive aspirates and prognosis in numerous clinical cases.

Rat lung cancer induced by malathion and estrogen.

Lung cancer can originate from exposure to exogenous and endogenous environmental carcinogens. The use of organophosphorus insecticides has significantly increased in agricultural environments and in urban settings. There is evidence that estrogen can increase lung cancer risk in women. The aim of the present study was to analyze morphological and molecular alterations induced by malathion (M) and 17beta-estradiol (E2) in rat lung tissues. There were four groups: saline solution (control) (100 microg/100 g body weight; BW), M (22 mg/100 g BW), E2 (30 microg/100 gr BW) and combination of both. The animals were injected over a 5-day period and sacrificed 240 days after treatments and lung tissues were excised and analyzed for morphological alterations. Morphometric analysis indicated that M plus E2-treated animals showed a significantly (P<0.05) higher incidence of parenchyma with alveolar proliferative lesions (PAPL), preneoplastic lesions in bronchiolar epithelium (hyperplasia, metaplasia, carcinoma in situ and invasive carcinoma) and atypical lymphatic morphology (lymphatic cell aggregates; LCA) than M or E2 alone-treated and control animals after 240 days. Molecular biology studies indicated that c-ErbB2 and Rho-A had higher protein expression in M plus E2-treated animals in comparison to control and either M- or E-treated animals. In summary, the combination of M and E2 sharply induced pathological lesions in lung alveolar parenchyma, bronchiolar epithelia and lymphatic tissues, in comparison to control animals or in animals treated with either substance alone. These results indicated an increase in risk of rodent lung tumor formation by environmental and endogenous substances.

Gene expression profiling of breast cells induced by X-rays and heavy ions.

Several genetic aberrations and gene expression changes have been shown to occur when cells are exposed to various types of radiation. The integrity of DNA depends upon several processes that include DNA damage recognition and repair, replication, transcription and cell cycle regulation. Ionizing radiation has many sources, including radon decay from the soil and X-rays from medical practice. Epidemiological evidence indicates a risk for cancer by inducing genetic alterations through DNA damage, and molecular alterations have been reported in epidemiological studies of the A-bomb survivors. A spontaneously immortalized human breast epithelial cell model, MCF-10F, was used to examine the gene expression profiling of breast cells induced by X-ray and heavy ion exposure, by a cDNA expression array of DNA damage and repair genes. This cell line was exposed to 10, 50, 100 and 200 cGy of either X-rays or heavy ions and gene expression profiles were studied. Results indicated that out of a total of 161 genes, 38 were differentially expressed by X-ray treatment and 24 by heavy ion (Fe(+2)) treatment. Eight genes were common to both treatments and were confirmed by Northern blot analysis: BRCA1, BIRC2/CIAP1, CENP-E, DDB1, MRE11A, RAD54/ATRX, Wip1 and XPF/ERCC4. A number of candidate genes reported here may be useful molecular biomarkers of radiation exposure in breast cells.

Cancer genes induced by malathion and parathion in the presence of estrogen in breast cells.

The identification of genes involved in the process of neoplastic transformation is essential for analyzing the progression of breast cancer when induced by endogenous and exogenous agents, among which are the estrogens and the organophosphorous pesticides, respectively. It is important to consider the impact of such substances when they are present in combination. In vitro experimental models are needed in order to understand breast carcinogenesis. The aim of this work was to examine the effect of 17beta estradiol (estrogen) combined with either malathion or parathion on the transformation of human breast epithelial cells in vitro. Results showed that estrogen combined with either malathion or parathion altered cell proliferation and induced cell transformation as well as exhibited significant invasive capabilities as compared to the control MCF-10F cell line. Several genes were up-regulated by the effect of all of the treatments, such as the cyclins, cyclin D1 and cyclin-dependent kinase 4, IGFBP3 and IGFBP5, and keratin 18. The c-Ha-ras oncogene was up-regulated by the effect of malathion alone and with the combination of estrogen and either malathion or parathion. The DVL1 gene was up-regulated only with malathion alone and the combination of parathion with estrogen. Expression of the HSP 27, MCM2 and TP53 inducible protein 3 genes was up-regulated with malathion alone and with the combination of estrogen and either malathion or parathion while TP53 (Li-Fraumeni syndrome) was up-regulated by estrogen alone and malathion alone. Thus, we suggest that pesticides and estrogens affect human breast cells inducing molecular changes indicative of transformation.

Cell adhesion proteins altered by 17beta estradiol and parathion in breast epithelial cells.

The association between breast cancer initiation and prolonged exposure to estrogen suggests that this hormone may also have an etiologic role in such a process. On the other hand, many studies have found an association between human cancer and exposure to agricultural pesticides such as parathion, an organophosphorous pesticide used in agriculture to control mosquito plagues. However, the key factors behind the initiation of breast cancer remain to be elucidated. The aim of this study was to determine the effect of 17beta estradiol (estrogen) and parathion on protein expression in cell transformation of human breast epithelial cells in vitro. Estrogen and parathion alone and in combination induced malignant transformation of an immortalized human breast epithelial cell line, MCF-I0F, as indicated by anchorage independency and invasive capabilities. The results indicate that a combination of estrogen and parathion increased the expression of related cell adhesion proteins such as Dvl, Notch, CD146 and beta catenin. In conclusion, it can be suggested that pesticides affect human breast cell adhesion changes indicative of transformation.

Human drug metabolism genes in parathion-and estrogen-treated breast cells.

Environmental chemicals may be involved in the etiology of breast cancer. Among them, organophosphorous compounds are the most widely used pesticides because of their extensive use in agriculture, medicine and industry. The risk of breast cancer is associated with prolonged exposure to female hormones and is attributed to estrogen since prolonged stimulation by steroid hormones may increase cell division. The aim of the present study was to identify the differentially expressed genes encoding enzymes that are important to drug transport and metabolism in parathion- and estrogen-treated human breast epithelial cell lines using cDNA microarrays. MCF-l0F, an immortalized human breast epithelial cell line was treated with parathion and estrogen, either alone or in combination, and malignant cells were developed through a series of sequential steps. Differential expression from the drug metabolism gene array showed that 17 genes were found to be altered either by parathion or estrogen alone, or the combination of both. Among the genes altered by parathion in comparison to the control were CHST5, CHST6 and CHST7 (sulfotransferases); CYP2F1, CYP3A7 and CYP4F3 (CYPs); GSTP1, GSTT2 and MGST1 (GSTs); MT1X (metallothionein); TPMT (methyltransferase); UGT1A1 and UGT2B (UDP glycosyltransferases). The same genes were down-regulated in estrogen alone including several metallothioneins (MT1A, MT1E, MT1H, MT1L and MT2A). The combination of parathion and estrogen induced down-regulation of three sulfotransferases, CYP2F1 and CYP4F3, MGST1, all metallothioneins and TPMT genes. There was no change in CYP3A7, GSTP1, GSTT2, UGT1A1 and UGT2B genes in the presence of both substances. It can be concluded from this study that organophosphorous pesticides such as parathion in the presence of estradiol induced changes in human drug metabolism gene expression in breast cells.

PAC1 is a direct transcription target of E2F-1 in apoptotic signaling.

E2F-1 controls multiple cellular activities through transcriptional regulation of its target genes. As a mediator of cell death, E2F-1 can eliminate latent neoplastic cells through apoptosis. However, the mechanism by which E2F-1 mediates cancer cell killing is largely unknown. In this paper, we report that phosphatase of activated cells 1 (PAC1) phosphatase is a direct transcription target of E2F-1 in signaling apoptosis. We show that ectopic E2F-1 increases expression of PAC1 at both transcriptional and translational levels in breast cancer cells. E2F-1 physically interacts with the promoter of PAC1, binds to its consensus sequence in the promoter and transactivates the PAC1 promoter. E2F-1 suppresses extracellular signal-regulated kinase (ERK) phosphorylation through PAC1 and causes cancer cell death by apoptosis following treatment with a chemotherapeutic agent N-4-hydroxyphenylretinamide (4-HPR). Furthermore, ectopic PAC1 inhibits ERK phosphorylation and mediates cell killing. Moreover, endogenous E2F-1 upregulates PAC1 and suppresses ERK activity, leading to cell death in response to 4-HPR. These results reveal a crucial role of PAC1 in E2F-1-directed apoptosis. Our study demonstrates that E2F-1 mediates apoptosis through transcriptional regulation of PAC1 and subsequent suppression of the ERK signaling. Our findings establish a functional link between E2F-1 and mitogen-activated protein kinases. The E2F-1-PAC1 cascade in cancer cell killing may provide a molecular basis for cancer therapeutic intervention.

Cell proliferation and tumor formation induced by eserine, an acetylcholinesterase inhibitor, in rat mammary gland.

Environmental chemicals may be involved in the etiology of breast cancer. There is substantial evidence that breast cancer risk is associated with prolonged exposure to female hormones. Among these hormonal influences a leading role is attributed to the ovarian hormone estradiol, since breast cancer does not develop in the absence of ovaries. The rat mammary gland has special characteristics that make it an ideal organ for studying development, cell proliferation and transformation. In vivo and in vitro model systems for cell proliferation and mammary carcinogenesis have allowed morphological and biochemical analysis under different experimental conditions. The aim of this study was to examine the effect of eserine, an acetylcholinesterase inhibitor, as are the organophosphorous compounds malathion and parathion, and 17beta estradiol on cell proliferation and tumor formation that takes place in the rat mammary gland after in vivo and in vitro treatment. These studies showed that eserine and 17beta estradiol were capable of inducing carcinogenesis in the epithelium of rat mammary glands. It was found that there was a significant increase in the number of cells per duct of the 44-day-old rat mammary gland after the 10-day eserine treatment, compared to the control. A higher increase was observed in the animals treated for 10 days with eserine followed by 30-daily injections of estrogen in comparison to control animals. In 12 animals, two mammary tumors were directly developed in response to 17beta estradiol injected at 39 days of age with a latency period of 180 and 245 days, respectively. Such tumors were metastatic to the lung. These results suggest that terminal end buds are major targets related to rat mammary carcinogenesis and 17beta estradiol can be an initiator and promoter in this process.

Allelic imbalance at 11q23-q24 chromosome associated with estrogen and radiation-induced breast cancer progression.

Multiple genetic alterations are common in cancers including those of the breast. The mechanisms leading to these alterations such as point mutations, gene amplifications, deletions and replication error are often associated with frequent and consistent loss of heterozygosity (LOH) or microsatellite instability (MSI). Several cytological and molecular studies have shown high frequency loss of genetic information on the long arm of chromosome 11 (i.e., 11q) in various primary breast cancers. In the present study allelic alterations in a refined position on the long arm of chromosome 11 were studied to identify the spectrum of induced damage at different stages of malignant transformation of MCF-10F cell lines after exposure to high-LET radiation using alpha-particles and exposure to estradiol by using PCR-single strand conformation polymorphism (SSCP) and fluorescence in situ hybridization (FISH) analysis. Microsatellite markers were selected from chromosome 11 (11q23-q24 loci) and it was found that frequency of allelic imbalance occurs at different stages of tumor progression with a range of 15-45% depending on the marker studied. These results strongly suggested the presence of several tumor suppressor genes in this critical region of chromosome 11 (11q23-q24). It also represents the first indication of allele loss at these loci in human breast epithelial cells induced by radiation and estrogen treatment suggesting a potential interventional target in breast carcinogenesis.

Growth factor biomarkers associated with estrogen- and radiation-induced breast cancer progression.

Breast cancer is the most common cancer in women worldwide. Transformation of a normal cell to a malignant one results from mutations in genes that encode key regulatory proteins. Growth factors are proteins secreted by a variety of transformed cells and tumors and function as autocrine regulators of growth. Biomarkers associated with cancer were examined in human breast epithelial cells transformed by high-LET radiation in the presence of 17beta-estradiol. An established cancer model was used in these studies. The MCF-10F cells that were irradiated with double doses of alpha-particles in the presence of estrogen (60 cGy + E/60 cGy + E, named Alpha 5) showed gradual phenotypic changes relative to control, including tumorigenicity in heterologous animals. Protein expression was determined by quantification of immunofluorescence staining coupled with confocal microscopy. The transforming growth factor alpha, epidermal growth factor, ERK1 and fibroblast growth factor-1 (Int2) protein expression was analyzed. Increased protein expression was observed in non-tumorigenic and tumorigenic alpha-irradiated and estrogen-treated cells. However, Stat-1alpha and pS2 protein expression was only increased in the tumorigenic Alpha 5 and Tumor 2 cell lines. It can be concluded that high-LET radiation in the presence of estrogen-induced changes in the proteins associated with growth factors and their overexpression may be a critical step in the cascade of events that characterize progression in breast cancer.

Differential gene expression of sulindac-treated human breast epithelial cells.

Breast cancer is the most common malignancy and the second major cause of cancer-related deaths among women in the United States. Recent advances in the molecular genetics of breast cancer have identified various genes associated with tumorigenesis. There is evidence that non-steroidal anti-inflammatory drugs, e.g. sulindac, have some anti-proliferative effects on various tumors involving altered p53 function. Most of these studies have been performed with various human colon carcinoma cell lines and few of them focus on non-malignant proliferative human mammary epithelial cell lines. Therefore, the present study was undertaken to analyze the differentially expressed genes of the p53 signaling pathway by means of a gene array for the immortalized human breast epithelial cell line, MCF-10F, treated with sulindac. Out of the total 96 genes, only 17 were altered by the drug treatment. Among these 17 genes, 6 showed significant alteration (Q > 2.0), whereas 11 genes showed moderate alterations. Altered genes included BRCA1 associated protein-1 [ubiquitin carboxy-terminal hydrolase (bap1)]; cell division cycle 2, G1 to S and G2 to M [cdk1(cdc2)]; and DNA-damage-inducible transcript 1 (gadd45), which were down-regulated. However, N-myc gene 1 (rtp), promyelocytic leukemia (pml), and nuclear factor of kappa-light polypeptide gene enhancer in B-cell 3 and p65 [avian (rel A)] were up-regulated. Northern blot analysis confirmed some of these alterations. The alteration of p53 signaling pathway gene markers by sulindac treatment can give us valuable information about the response to drug treatments in a proliferative cell population.

Oncoprotein expression and morphological phenotypes of human breast epithelial cells transformed by the c-Ha-ras oncogene.

Activated oncogenes have been detected in a variety of malignant tumors and altered expressions of certain genes are known to play a functional role in the cancer process. The chemical carcinogen, BP, and the insertion of c-Ha-ras, induced characteristics of transformed phenotypes in a suitable human breast epithelial cell line. Carcinogen-treated and Ha-ras-transfected cells showed a progression of changes in the morphology, anchorage independent growth, invasiveness and tumorigenicity in SCID mice. Tumor growth occurs after a series of molecular events that parallel morphological changes. The aim of this work was to determine the neoplastic phenotypes following treatment with benzo(a)pyrene (BP) and transfection with c-Ha-ras oncogene changes and PCNA, Neu, ErbB-3 and Cytokeratin 18 protein expression in MCF-10F cells, a spontaneously immortalized human breast epithelial cell line. Protein expression was determined by immunofluorescent staining coupled with confocal microscopy. An increased oncoprotein expression in comparison to MCF-10F cells was observed in PCNA, Neu, ErbB-3 and Cytokeratin 18 protein expression in breast epithelial cells transformed with a chemical carcinogen and/or oncogene transfected that are not present in the MCF-10F. This in vitro cancer model can be used as a valuable model in the study of breast carcinogenesis.