FBXW7 attenuates tumor drug resistance and enhances the efficacy of immunotherapy

FBXW7 (F-box and WD repeat domain containing 7) is a critical subunit of the Skp1-Cullin1-F-box protein (SCF), acting as an E3 ubiquitin ligase by ubiquitinating targeted protein. Through degradation of its substrates, FBXW7 plays a pivotal role in drug resistance in tumor cells and shows the potential to rescue the sensitivity of cancer cells to drug treatment. This explains why patients with higher FBXW7 levels exhibit higher survival times and more favorable prognosis. Furthermore, FBXW7 has been demonstrated to enhance the efficacy of immunotherapy by targeting the degradation of specific proteins, as compared to the inactivated form of FBXW7. Additionally, other F-box proteins have also shown the ability to conquer drug resistance in certain cancers. Overall, this review aims to explore the function of FBXW7 and its specific effects on drug resistance in cancer cells.

Abstract 021: Macrophage-dependent Impairment of the Alpha 2-adrenergic Receptor Occurs in DOCA-salt but Not Obesity-associated Hypertension

Inflammation and increased sympathetic activity contribute to hypertension. Alpha 2-adrenergic receptor (α2AR) activation decreases norepinephrine (NE) release from sympathetic nerves by inhibiting Ca 2+ channels. We hypothesized that macrophage infiltration into mesenteric arteries (MA) impairs α2AR in salt-sensitive and obesity-associated hypertensive rats. Uniphrectomized Sprague Dawley (SD) rats were given water (SHAM) or 200mg/kg DOCA (pellet, sc) and water containing 1% NaCl, 0.2% KCl (DOCA) for 4 weeks. A high fat diet (HFD, 60% kcal from fat, 0.33% NaCl, 1% K + ) or normal fat diet (NFD, 10% kcal from fat, 0.24% NaCl, 0.36% K + ) was given to a second group of SD rats for 20 weeks and to Dahl salt-sensitive (SS) rats for 24-26 weeks after weaning (3 weeks). Immunohistochemistry for CD163 (macrophage marker) was used to count macrophages in MA. Whole-cell patch clamp was used on dissociated celiac ganglion neurons to evaluate α2AR-mediated Ca 2+ current inhibition with NE (1 μM). Liposome-encapsulated clodronate (Clod) was used to deplete rats of macrophages. Plasma aldosterone levels were assessed by ELISA. Summary data is provided in Table 1. Systolic blood pressure was higher in DOCA vs SHAM and HFD vs NFD rats. Vascular macrophage number increased in DOCA vs SHAM but not in HFD vs NFD rats. NE inhibited Ca 2+ current to a greater degree in neurons of SHAM vs DOCA but not NFD vs HFD rats. Clodronate reduced vascular macrophages in all rats and preserved α2AR-mediated inhibition of Ca 2+ current in DOCA rats. HFD did not affect plasma aldosterone levels. Therefore, we conclude that macrophage-associated impairment of α2AR may only occur in states of mineralocorticoid and salt excess.

O17. The development of 'time release' nail enamels

In our recent studies on the effects of plasticizers on nail enamel films, we developed a high interest in a phenomenon that we named as 'internal flow'[1]. During the film forming process there is an area that develops beneath the film surface where the film components remain dynamic and mobile. The time frame during which the film maintains this status is directly related to the balance of the resins, plasticizers, polymers and solvents utilized. We found that the longer this 'internal flow' persists, the better the nail enamel wears. At Tevco, we have been able to control the rate at which the solvents and plasticizers flash off the substrate during the film forming process by regulating the interactions and the levels of film constituents. This 'time release' action is the foundation of our study. This study shows that the alkyl adipates are an integral component in controlling the film's internal flow through time release. As plasticizers, these materials, when in proper balance with other components, can create a film surface that is crack-and scuff-resistant. Finally, the substrate in this study is the human nail. The film we developed has to adhere and provide consistent performance over a wide range of temperatures, oil content and the surface abrasion of human nails. We have found that by utilizing adhesion promoters in conjunction with our optimized internal flow time release formula, our film meets all required criteria and generally outperforms conventional quick dry films. In conclusion, we have been able to optimize the film characteristics of conventional quick dry nail enamels. By controlling the internal flow of the film, we can enhance the performance criteria generally expected by consumers in nail enamels.

Streptococcus agalactiae CAMP factor/protein B does not bind to human IgG

CAMP factor is an extracellular cytolytic protein produced by Streptococcus agalactiae. CAMP factor has been reported to bind the Fc fragments of immunoglobulin G (IgG) and has therefore also been called protein B, in analogy to protein A of Staphylococcus aureus. We attempted to characterize the interaction of protein B with IgG in more detail. In contrast to protein A, CAMP factor does not inhibit the activation of complement by hemolysin antibodies bound to sheep red cell surfaces. IgG also failed to inhibit the co-hemolytic activity of CAMP factor, which is in disagreement with previous findings. After co-incubation, CAMP factor and IgG were cleanly separated by gel filtration, indicating that no binding had occurred.

Evolution of sex-biased maternal effects in birds: II. Contrasting sex-specific oocyte clustering in native and recently established populations

In species that produce broods of multiple offspring, parents need to partition resources among simultaneously growing neonates that often differ in growth requirements. In birds, multiple ovarian follicles develop inside the female at the same time, resulting in a trade-off of resources among them and potentially limiting maternal ability for sex-specific allocation. We compared resource acquisition among oocytes in relation to their future sex and ovulation order in two populations of house finches with contrasting sex-biased maternal strategies. In a native Arizona population, where mothers do not bias offspring sex in relation to ovulation order, the male and female oocytes did not show sex-specific trade-offs of resources during growth and there was no evidence for spatial or temporal segregation of male and female oocytes in the ovary. In contrast, in a recently established Montana population where mothers strongly bias offspring sex in relation to ovulation order, we found evidence for both intra-sexual trade-offs among male and female oocytes and sex-specific clustering of oocytes in the ovary. We discuss the importance of sex-specific resource competition among offspring for the evolution of sex-ratio adjustment and sex-specific maternal resource allocation.