Patrizia Damonte

Additional file 4: Fig. S4. SIRT6 levels do not affect Pdk1/4 expression but regulate intracellular calcium concentration in breast cancer cells. A, RNA was extracted from mammary tumors from twelve-week-old MMTV-PyMT+/-; Sirt6+/+ (n = 6) and MMTV-PyMT+/-; Sirt6+/- (n = 5) mice and Pdk1 and Pdk4 expression was determined by QPCR. B, MDA-MB-231 were engineered to overexpress WT SIRT6 (or a control vector) or to express a SIRT6-targeting shRNA (or a control vector). Thereafter, cells were used to measure intracellular calcium concentration. Data are presented as mean ± SD of three separate experiments. *p<0.05, ns: not statistically significant.

Low-power hematoxylin and eosin histomorphology of the MINO precancer filling the precleared fat pad. Intact gland is seen for comparison in the bottom left corner. The lymph node is seen (LN) at the left, and no invasion of the node by precancer tissue is seen. The edge of the precancer is seen at higher power and is similar to a normal developing mammary gland terminal end bud with mitoses (arrowhead) and remodeling via apoptosis to clear the luminal space. In the area of precancer in the center of the growth there is an organized relationship between the transplanted MINO tissue and the host stroma. The MINO cells differentiate to form acinar and ductal structures with high intralesional cell heterogeneity. In this heterogeneous differentiated zone of precancer tissue, an area of transformation to invasive carcinoma is characterized by increased mitoses (arrowheads) and much less residual host stromal tissue. MINO, mammary intraepithelial neoplasia outgrowth.<b>Copyright in...

Inverted microscope phase contrast images as well as histologic images generated from paraffin-embedded 4 μm sections of the three-dimensional cultures stained by immunohistochemistry with CK8–18 or CK14 are shown. The magnification scale (lower right panel i) is identical for all histology panels and approximate for the inverted microscopy photographs. CK8–18 confirms that the major cell population is a luminal phenotype, but CK14 shows that there is also myoepithelial differentiation of single cells, documenting bipotential of the individual cells giving rise to these three-dimensional structures. A single MINOsphere from line 4w4 was transplanted from the three dimensional culture into the gland cleared fat pad of a 3-week-old female FVB/n mouse. The mammary gland was removed 10 weeks after transplant and a whole mount mammary gland preparation was made with hematoxylin stain to visualize cell density . After photography, the same gland was processed for histologic sectioning, an...

Boosting NAD + biosynthesis with NAD + intermediates has been proposed as a strategy for preventing and treating age-associated diseases, including cancer. However, concerns in this area were raised by observations that nicotinamide phosphoribosyltransferase (NAMPT), a key enzyme in mammalian NAD + biosynthesis, is frequently up-regulated in human malignancies, including breast cancer, suggesting possible pro-tumorigenic effects for this protein. We addressed this issue by studying NAMPT expression and function in human breast cancer in vivo and in vitro. Our data indicates that high NAMPT levels are associated with aggressive pathological and molecular features, such as ER negativity, as well as Her2-enriched and basal-like PAM50 phenotypes. Consistent with these findings, we http://www.jbc.org/cgi/doi/10.1074/jbc.M114.594721 The latest version is at JBC Papers in Press. Published on October 20, 2014 as Manuscript M114.594721 Copyright 2014 by The American Society for Biochemistry ...

Arginine metabolism plays a significant role in regulating cell function, affecting tumor growth and metastatization. To study the effect of the arginine-catabolizing enzyme Arginase1 (ARG1) on tumor microenvironment, we generated a mouse model of mammary carcinogenesis by crossbreeding a transgenic mouse line overexpressing ARG1 in macrophages (FVBArg+/+) with the MMTV-Neu mouse line (FVBNeu+/+). This double transgenic line (FVBArg+/−;Neu+/+) showed a significant shortening in mammary tumor latency, and an increase in the number of mammary nodules. Transfer of tumor cells from FVBNeu+/+ into either FVB wild type or FVBArg+/+ mice resulted in increase regulatory T cells in the tumor infiltrate, suggestive of an impaired antitumor immune response. However, we also found increased frequency of tumor stem cells in tumors from FVBArg+/−;Neu+/+ transgenic compared with FVBNeu+/+ mice, suggesting that increased arginine metabolism in mammary tumor microenvironment may supports the cancer ...

The NAD-dependent deacetylase SIRT6 is an emerging cancer drug target, whose inhibition sensitizes cancer cells to chemo-radiotherapy and has pro-differentiating effects. Here we report on the identification of novel SIRT6 inhibitors with a salicylate-based structure. The new SIRT6 inhibitors show improved potency and specificity compared to the hit inhibitor identified in an in silico compound screen. As predicted based on SIRT6 biological roles, the new leads increase histone 3 lysine 9 acetylation and glucose uptake in cultured cells, while blocking TNF-α production and T lymphocyte proliferation. Notably, the new SIRT6 inhibitors effectively sensitize pancreatic cancer cells to gemcitabine. Finally, studies of compound fingerprinting and pharmacokinetics defined the drug-like properties of one of the new SIRT6 inhibitors, potentially allowing for subsequent in vivo proof-of-concept studies. In conclusion, new SIRT6 inhibitors with a salicylate-like structure were identified, which are active in cells and could potentially find applications in disease conditions, including cancer and immune-mediated disorders.

NAD⁺ biosynthesis through nicotinamide phosphoribosyltransferase (NAMPT) holds potential as a target for the treatment of inflammatory disorders due to NAD(+)'s role in immune cell signaling and metabolism. In addition to its activity as an enzyme, NAMPT is also secreted in the extracellular space where it acts as a pro-inflammatory and proangiogenic cytokine. NAMPT inhibition with FK866 has anti-inflammatory activity in different models of immune disorders and it prevents ischemia-reperfusion-induced heart damage by dampening the production of neutrophil chemoattractants. NAMPT blockade with a neutralizing antibody has beneficial effects in an acute lung injury model. Last, but not least, the anticancer activity of NAMPT inhibitors may also reflect, at least in part, their ability to modify the cancer microenvironment through their anti-inflammatory properties. Overall, NAMPT inhibition holds potential for the treatment of inflammation-related disorders and the development of effective and safe NAMPT inhibitors remains an area of strong interest in pharmaceutical research.

ABSTRACT 1. Conjugated linoleic acid (CLA) contains conjugated double bonds and is known as a family of isomers of linoleic acid that can be found in the meat and dairy products. 2. In vitro studies have shown that CLA can inhibit the growth of mammary, colon, colorectal, gastric, prostate, and malignant liver cell lines and has also been shown to induce the expression of apoptotic genes. 3. The incidence of mammary tumors induced by methylnitrosourea and forestomach tumors induced by benzo[a]pyrene was decreased by CLA in rodent models. CLA isomers may regulate tumorigenesis through different mechanisms by altering lipid metabolism, regulation of oncogene expression, regulation of cyclooxygenase-2 expression, and lipooxygenase metabolic pathways. 4. The specific effects of CLA appear to be dependent on which isomer is assessed. The effects of various isomers in vitro and in vivo have recently been reviewed. With respect to breast cancer, the t10, c12-CLA isomer was shown to enhance tumorigenesis in a transgenic mouse mammary tumor model when compared to the c9, t11-CLA isomer. In a parallel study, increased polyp diameter was associated with supplementation of the t10, c12-CLA diet compared to the c9, t11-CLA diet, which decreased colonic polyp number in the mouse MIN model of colon cancer. 5. Future studies should investigate the effects of CLA on developing cancer tissues, their progenitor cells, and stem cells. Moreover, animal studies should use models that better recapitulate human cancers in an effort to shorten the time for the development of clinical studies. Therefore, no recommendations for CLA consumption in the context of prevention or therapy can be made until such studies are undertaken. Key WordsCLA-breast cancer-metastasis-mechanisms

Epithelial–mesenchymal transition tumorigenesis in the mouse has been described for over 100 years using various terms and with little comprehension of the underlying mechanisms. Recently, epithelial–mesenchymal transition tumors have been recognized in mammary glands of genetically engineered mice. This review provides a historical perspective and the current observations in the context of some of the key molecular biology. The biology of mouse mammary epithelial–mesenchymal transition tumorigenesis is discussed with comparisons to human breast cancer.