Cks1, a small protein whose expression is strongly associated with aggressive breast tumors, is a component of cyclincdk complexes, as well as the SCF Skp2 ubiquitin ligase. In these studies, we explored its roles in estrogen receptor-positive breast tumor cells. When exposed to the antiestrogen ICI 182780, these cells accumulate in G 1 by reducing the expression of Cks1, and increasing the levels of p130/Rb2, a cdk2 inhibitor and SCF Skp2 target. Heregulin B1 or estradiol abrogate antiestrogen effects by increasing Cks1 expression, downregulating p130/Rb2 and inducing S phase entry. Depletion of Cks1 in these cells by RNA interference concomitantly decreased Skp2 and up-regulated p130/Rb2 and another SCF Skp2 target, p27 Kip1. Remarkably, however, Cks1-depleted cells not only exhibit slowed G 1 progression, but also accumulate in G 2 -M due to blocked mitotic entry. Notably, we show that cdk1 expression, which is crucial for M phase entry, is drastically diminished by Cks1 depletion, and that restoration of cdk1 reduces G 2 -M accumulation in Cks1-depleted cells. cdk1 reduction in Cks1-depleted cells is a consequence of a marked decrease in its mRNA and not due to alteration in its proteolytic turnover. Both heregulin B1 and estradiol could neither restore cdk1 nor sustain cycling in Cks1-depleted cells, although classical estrogen receptor function remained unaltered. Cks1 depletion also decreased Skp2 in human mammary epithelial cells without altering cell cycle progression. Thus, the indispensability of Cks1 to the breast cancer cell cycle, versus its redundancy in normal cells, suggests that Cks1 abrogation could be an effective interventional strategy in breast cancer. [Cancer Res 2007;67(23):11393-401]

Supplementation with exogenous growth factors such as fibroblast growth factors (FGFs) is essential for anchorage-independent growth of the SW-13 human adrenal adenocarcinoma cell line. We have found that SW-13 cells express mRNAs for FGFRs 1, 3, and 4, but not FGFR2. To assess the roles of individual FGFRs, in anchorageindependent growth, we determined the effects of downregulation of each FGFR on FGF2-and FGF4-mediated soft agar colony formation in these cells. Using RNAi strategies we found that knockdown of either FGFR1 or FGFR3 leads to inhibition of FGF2-or FGF4-induced soft agar clonogenicity without affecting that induced by heregulin ß1. However, this inhibition is independent of ERK1/2 activation as levels of FGF-induced phospho-ERK 1/2 remain unchanged upon knockdown of either FGFR1 or FGFR3. Conversely, RNAimediated knockdown of FGFR4 appeared to have no significant effect on either FGF2-or FGF4-induced anchorageindependent colony formation, or ERK1/2 phosphorylation. These results suggest that constitutive levels of both FGFR1 and FGFR3, but not FGFR4 are essential for FGF-stimulated anchorage-independent growth of SW-13 cells.

Obesity is defined as a BMI greater than 25 kg/m 2. Once thought to simply be a nutritional disorder, obesity has become a major health concern characterized by a state of constant low-grade inflammation caused by chronic adiposity. This state of inflammation is characterized by circulating inflammatory mediators, such as IL-6, leptin, and TNF-α, as well as varying levels of glucose-regulating hormones produced by obese adipose tissue. When left untreated, obesity can lead to a number of diseases including, but not limited to, cardiovascular disease, metabolic syndrome, neurodegeneration, type II diabetes mellitus, chronic kidney disease, and infertility. The distribution of adiposity differs in men and women, and these differences, along with the differences in sex hormones and sex hormone levels, can exacerbate or attenuate the course of disease pathology. Obesity can also be exacerbated by stress, which can worsen disease pathogenesis. In this review, we will explore how obesity affects inflammation and disease and how sex can affect the course of these diseases.

Supplementary Figure 4 from Cks1 Regulates cdk1 Expression: A Novel Role during Mitotic Entry in Breast Cancer Cells

Supplementary Figure 1 from Cks1 Regulates cdk1 Expression: A Novel Role during Mitotic Entry in Breast Cancer Cells