Abstract. The current hypothesis of tumorigenesis in humans suggests that cancer cells acquire their hallmarks of malignancy through the accumulation of advantageous gene activation and inactivation events over long periods of time. For breast cancer development, this multistep process may manifest itself as a sequence of pathologically defined stages. It is widely held that breast cancer originates at the premalignant stage of atypical ductal hyperplasia, progresses to the preinvasive stage of ductal carcinoma in situ, and culminates in the potentially lethal stage of invasive ductal carcinoma. Tumor grade has been a highly valuable prognostic factor for breast cancer, and high-grade ductal carcinoma in situ lesions are associated with poor clinical outcome. The aim of this work was to investigate the BigH3 protein expression changes associated with various stages of breast cancer progression in comparison to benign specimens using tissue microarray technology. Pathological characteristics of breast tissues ranged from benign lesions to breast cancers either of lobular or ductal carcinomas in origin, and included in situ ductal carcinomas, lobular carcinomas, infiltrating ductal carcinomas, carcinomas, scirrhous carcinomas, adenocarcinomas and infiltrating colloid carcinomas. BigH3 protein expression was analyzed by immunohistochemistry in 192 cases of breast tumors. Results indicated a decrease in BigH3 protein expression from benign tissues to in situ ductal carcinoma, lobular carcinoma, infiltrating ductal carcinomas, carcinomas, scirrhous carcinoma, adenocarcinomas to infiltrating colloid carcinomas. We observed that the benign tissue had a 23-fold increase in BigH3 protein expression compared to the infiltrating colloid carcinoma which was the most malignant tissue analyzed. In summary, these studies confirmed the suppressor effect of the BigH3 gene expressed as protein expression in those processes related to the progression of breast tumorigenesis. We conclude that this protein can be used as a marker for breast cancer progression.

Human small airway epithelial cells (SAECs) previously immortalized with human telomerase reverse transcriptase (h-TERT) were continuously treated with sodium arsenite at a dose of 0.5 μg/mL in culture for up to 6 months. Arsenic-treated cells progressively displayed an increase in transformed phenotype including enhanced growth saturation density, plating efficiency, and anchorage-independent growth and invasion capability compared with their nontreated control cells. To determine whether arsenicinduced cell transformation was associated with genomic instability, treated and control cells were also analyzed for micronuclei formation. A 4.8-fold increase in micronuclei incidence in arsenic-treated cells was detected in conjunction with increased N-phosphonacetyl-L-aspartate (PALA)-resistant characteristics. In addition, arsenic-treated cells showed an increase in c-H-ras, c-myc, and c-fos protein expression relative to controls. The change in oncoprotein expression correlated with a decrease in wildtype p53 expression and hyperphosphorylated retinoblastoma. Taken together, these results strongly suggest that h-TERT immortalized human small airway epithelial cells underwent step-wise transformation after inorganic arsenic treatment.

High-resolution mass spectrometry is currently used to determine the mass of biologically active compounds in medicinal plants and food and UHPLC-Orbitrap is a relatively new technology that allows fast fingerprinting and metabolomics analysis. Forty-two metabolites including several phenolic acids, flavonoids, coumarines, tremetones and ent-clerodane diterpenes were accurately identified for the first time in the resin of the medicinal plant (Asteraceae) a Chilean native species, commonly called umatola, collected in the pre-cordillera and altiplano regions of northern Chile, by means of UHPLC-PDA-HR-MS. This could be possible by the state of the art technology employed, which allowed well resolved total ion current peaks and the proposal of some biosynthetic relationships between the compounds detected. Some mayor compounds were also isolated using HSCCC. The ethanolic extract showed high total polyphenols content and significant antioxidant capacity. Furthermore, several biological assays were performed that determined the high antioxidant capacity found for the mayor compound isolated from the plant, 11--coumaroyloxyltremetone.

Abstract. Cancer progression has been associated with an increase in genomic instability indicated by inactivation of tumor suppressor genes and activation of oncogenes. Epidemiological and experimental evidence has implicated estrogens in the etiology of breast cancer. To study environmental organophosphorous pesticides is of interest since evidence indicate that pesticides may enhance cell division, increasing the risk of breast cancer. The aim was to evaluate the effects of these pesticides, such as parathion and malathion in the presence of estrogen on malignant transformation as well as on genomic instability, that is in the frequency of loss of heterozygosity (LOH) and microsatellite instability (MSI). The MCF-10F immortalized human breast epithelial cell line, that was treated with parathion or malathion alone and in combination with estrogen was used. These studies indicated that either pesticide alone or in combination with estrogen induced malignant transformation as shown by anchorageindependent growth capability and invasive characteristics in comparison to control. Such malignant phenotypic characteristics were corroborated by significant (P<0.05) increase in p53 and c-Ha-ras protein expression. Results indicated different degrees of allelic imbalance in the form of LOH or MSI with different microsatellite markers. MSI was found in malathion and estrogen-treated cells with a marker used for p53 tumor suppressor gene at loci 17p13.1. The same combination of substances presented MSI with a marker used for c-Ha-ras mapped in chromosome 11p14.1, as well as mutations in c-Ha-ras for codons 12 and 61. LOH was observed in codon 12 in the presence of estrogen or malathion alone. Parathion alone and combined with estrogen induced MSI in codon 61. It can be concluded that the organophosphorous pesticides parathion and malathion induced malignant transformation of breast cells through genomic instability altering p53 and c-Ha-ras, considered pivotal to cancer process.

Abstract. Curcumin (diferuloyl methane) is a well known antioxidant that exerts antiproliferative and apoptotic effects. Curcumin effect was evaluated in a breast cancer model that was developed using the immortalized breast epithelial cell line MCF-10F after exposure to low doses of high LET (linear energy transfer) α particles (150 keV/µm) of radiation, and subsequently cultured in the presence of 17β-estradiol (estrogen). This model consisted of human breast epithelial cells in different stages of transformation: i) MCF-10F; ii) Estrogen cell line; iii) a malignant Alpha3 cell line; iv) a malignant and tumorigenic, Alpha5 cell line; and v) a cell line derived from Alpha5 injected into the nude mice that gave rise to Tumor2 cell line. Curcumin decreased anchorage-independent growh in transformed breast cancer cell lines in comparison to their counterparts and increased the percentage of cells from G 0 /G 1 with a concomitant increase in G 2 /M phases, as well as a decrease in PCNA and Rho-A protein expression. Among the oncogenes, c-Ha-Ras and Ras homologous A (Rho-A) are important cell signaling factors for malignant transformation and to reach their active GTP bound state, Ras proteins must first release bound GDP mediated by a guanine nucleotide releasing factor (GRF). Then curcumin decrease RasGRF1 protein expression in malignant cell lines. Further, differential expression levels of cleaved (ADP) ribose polymerase 1 (PARP-1) and phosphorylated histone H2AX (γ-H2AX) were observed after curcumin treatment. It seems that PARP-1 similar to H2AX, confers cellular protection against radiation and estrogen-induced DNA damage mediated by curcumin. Therefore, targeting either PARP-1 or H2AX may provide an effective way of maximizing the therapeutic value of antioxidants for cancer prevention.

HSCCC allowed the isolation of 13 diterpenoids present in A. compacta. Three compounds are reported for the first time. Isolated azorellanes are more potent cytotoxic agents than are mulinanes. © 2015 Society of Chemical Industry.

Continuing with our study characterising Senecio nutans Sch. Bip., we have isolated and identified a simple coumarin, scopoletin, that could be relevant for the biological properties of the species related with the ancestral medical uses. This is the first report of scopoletin from S. nutans. In addition, the extract was analysed for its antioxidant activity using the ABTS and FRAP method as well as providing the first nutritional analyses of this plant from northern Chile highlands.

Breast cancer is the second cause of cancer‑related deaths in woman and the incidence of the disease has increased worldwide, in part due to improvements in early detection. Several drugs with anticancer effects have been extracted from plants in the last 20 years, many of which are particularly effective against breast cancer cells. In particular, we have become interested in the ethanolic extract from Senecio graveolens (synonym of S. nutans), a plant commonly called Chachacoma, in an effort to isolate compounds that could demonstrate cytotoxic effects on breast cancer cells. Senecio (Asteraceae) is the largest gender in Chile comprising approximatly 200 species. These herbs inhabit areas over 3,500 meters above the sea level in the Andes Mountains. S. graveolens is commonly used by local communities for its medicinal properties, particularly its capacity to ameliorate high-altitude-associated sickness. The cytotoxic effect of the alcoholic extract from S. graveolens, as well as its most abundant compound 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone, were tested in the breast cancer cell lines ZR-75-1, MCF-7 and MDA-MB‑231, and non-tumorigenic MCF-10F cells. We show that the phytochemical extract was able to induce cytotoxicity in cancer cells but not in MCF-10F. Importantly, this effect was enhanced under hypoxic conditions. However, 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone, the main compound, did not by itself show an effective anticarcinogenic activity in comparison to the whole extract. Interestingly, the cytotoxic effect of the phytochemical extract was dependent on the basal MnSOD protein expression. Thus, cytotoxicity was increased when MnSOD levels were low, but resistance was evident when protein levels were high. Additionally, the crude extract seems to trigger cell death by a variety of processes, including autophagy, apoptosis and necrosis, in MCF-7 cells. In summary, S. graveolens extract possess anticancer activity displaying a specific cytotoxic effect on cancer cells, thus serving as a potential source of phytochemical compounds for cancer treatment.