Curcumin (diferuloyl methane) is an antioxidant that exerts antiproliferative and apoptotic effects and has anti-invasive and anti-metastatic properties. Evidence strongly implicates that epithelial-mesenchymal transition (EMT) is involved in malignant progression affecting genes such as Slug, AXL and Twist1. These genes are abnormally expressed in many tumors and favor metastasis. The purpose of this study was to determine the potential effect of curcumin on EMT, migration and invasion. Triple-positive and triple-negative breast cancer cell lines for estrogen receptor (ER), progesterone receptor (PgR) and HER/neu were used: i) MCF-10F, a normal immortalized breast epithelial cell line (negative), ii) Tumor2, a malignant and tumorigenic cell line (positive) derived from Alpha5 cell line injected into the immunologically depressed mice and transformed by 60/60 cGy doses of high LET (linear energy transfer) α particles (150 keV/µm) of radiation and estrogen, and iii) a commercially available MDA-MB‑231 (negative). The effect of curcumin (30 µM for 48 h) was evaluated on expression of EMT-related genes by RT-qPCR. Results showed that curcumin decreased E-cadherin, N-cadherin, β-catenin, Slug, AXL, Twist1, Vimentin and Fibronectin protein expression, independently of the positivity of the markers in the cell lines. Curcumin also decreased migration and invasive capabilities in comparison to their own controls. It can be concluded that curcumin influenced biochemical changes associated with EMT-related genes that seems to promote such transition and are at the core of several signaling pathways that mediate the transition. Thus, it can be suggested that curcumin is able to prevent or delay cancer progression through the interruption of this process.
Prostate cancer is the second leading cause of cancer-associated deaths among men in the western countries. Here, we report that human RecQL4 helicase, which is implicated in the pathogenesis of a subset of cancer-prone Rothmund-Thomson syndrome, is highly elevated in metastatic prostate cancer cell lines. Increased RecQL4 expression was also detected in human prostate tumor tissues as a function of tumor grade with the highest expression level in metastatic tumor samples, suggesting that RecQL4 may be a potential prognostic factor for advanced stage of prostate cancer. Transient and stable suppression of RecQL4 by small interfering RNA and short hairpin RNA vectors drastically reduced the growth and survival of metastatic prostate cancer cells, indicating that RecQL4 is a prosurvival factor for prostate cancer cells. RecQL4 suppression led to increased poly(ADP-ribose) polymerase (PARP) synthesis and RecQL4-suppressed prostate cancer cells underwent an extensive apoptotic death in a PARP-1-dependent manner. Most notably, RecQL4 knockdown in metastatic prostate cancer cells drastically reduced their cell invasiveness in vitro and tumorigenicity in vivo, showing that RecQL4 is essential for prostate cancer promotion. Observation of a direct interaction of retinoblastoma (Rb) and E2F1 proteins with RecQL4 promoter suggests that Rb-E2F1 pathway may regulate RecQL4 expression. Collectively, our study shows that RecQL4 is an essential factor for prostate carcinogenesis.
Despite continuous advances in the knowledge of breast cancer pathophysiology, this type of neoplasia remains a leading cause of cancer-related death in women worldwide. Carcinogenesis takes a progressive course from somatic mutations, alteration of the DNA repair mechanisms, inhibition of growth suppressors, followed by cell proliferation, tissue invasion and risk of metastasis. Less than 10% of all cancers are hereditary, and in the case of breast cancer only 8%, a phenomenon linked to genetic changes in BRCA1 or BRCA2. All the other cancers can be caused by an infection (15%) or in most cases (75%) the etiology is unknown. Patients with genetic mutations in BRCA1 or BRCA2 have 30-60% likelihood of developing a second primary breast cancer and between 11 and 45% risk of ovarian cancer, HER-2/neu is overexpressed in ~30% of human breast tumors and it has a predictive role in chemotherapy and endocrine therapy.
Pirin is an oxidative stress (OS) sensor belonging to the functionally diverse cupin superfamily of proteins. Pirin is a suggested quercetinase and transcriptional activator of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. Its biological role in cancer development remains a novel area of study. This review presents accumulating evidence on the contribution of Pirin in epithelial cancers, involved signaling pathways, and as a suggested therapeutic target. Finally, we propose a model in which Pirin is upregulated by physical, chemical or biological factors involved in OS and cancer development.
Breast cancer is the most diagnosed cancer in the world, and it is the primary cause of cancer death for women. The risk of breast cancer is increased by endogenous factors like hormones and exogenous factors like radiation exposure that causes damage to the mammary epithelial cells leading to an inflammatory response. Chronic inflammation creates a microenvironment composed of, among other factors, chemokines, and interleukins, which promote cancer. The gene expression of the interleukin 1 receptor type 1, the interleukin 1 receptor antagonist, the Interleukin 1 Receptor Accessory Protein, the interleukin 6 cytokine family signal transducer, the C-X-C motif chemokine ligand 3, the C-X-C motif chemokine ligand 5, and the C-X-C motif chemokine ligand 6 were analyzed in an estrogen and radiation experimental breast cancer model. Furthermore, the expression of these genes was correlated with immune cell infiltration, estrogen receptor expression, and their clinical relevance in breast cancer patients based on data provided by The Cancer Genome Atlas database online. Results given by the experimental breast cancer model showed that all genes related to inflammation respond to ionizing radiation alone or in combination with estrogen. On the other hand, the immune response depended on the breast cancer type and on the expression of the gene that encoded the estrogen receptor. Finally, the importance of the expression of these genes in breast cancer is such that high
As an uncommon cancer, mesothelioma is very hard to treat with a low average survival rate owing to its usual late detection and being highly invasive. The link between asbestos exposure and the development of mesothelioma in humans is unequivocal. TGFBI, a secreted protein that is induced by transforming growth factor-β in various human cell types, has been shown to be associated with tumorigenesis in various types of tumors. It has been demonstrated that TGFBI expression is markedly suppressed in asbestos-induced tumorigenic cells, while an ectopic expression of TGFBI significantly suppresses tumorigenicity and progression in human bronchial epithelial cells. In order to delineate a potential role of TGFBI in mediating the molecular events that occur in mesothelioma tumorigenesis, we generated stable TGFBI knockdown mutants from the mesothelium cell line Met-5A by using an shRNA approach, and secondly created ectopic TGFBI overexpression mutants from the mesothelioma cell line H28 in which TGFBI is absent. We observed that in the absence of TGFBI, the knockdown mesothelial and mesothelioma cell lines exhibited an elevated proliferation rate, enhanced plating efficiency, increased anchorage-independent growth, as well as an increased cellular protein synthesis rate as compared with their respective controls. Furthermore, cell cycle regulatory proteins c-myc/cyclin D1/phosphor-Rb were upregulated; a more active PI3K/Akt/mTOR signaling pathway was also detected in TGFBI-depleted cell lines. These findings suggest that TGFBI may repress mesothelioma tumorigenesis and progression via the PI3K/Akt signaling pathway.