RanBPM inhibits BLT2-mediated IL-8 production and invasiveness in aggressive breast cancer cells

Two distinct forms of human BLT2: long-form and short-form BLT2

BLT2 is a low-affinity leukotriene B4 receptor that plays an essential role in the pathogenesis of various inflammatory diseases, including asthma and cancer. BLT2 is minimally expressed in a normal internal environment but is overexpressed in a stress-induced inflammatory environment. Recent research indicated that human BLT2 has two distinct forms. Although their functions are likely to be different, very few studies investigated these differences. Therefore, this paper will discuss about the two distinct forms of human BLT2; the short-form of BLT2 and the long-form of BLT2.

Structural and Functional Insights into GID/CTLH E3 Ligase Complexes

Multi-subunit E3 ligases facilitate ubiquitin transfer by coordinating various substrate receptor subunits with a single catalytic center. Small molecules inducing targeted protein degradation have exploited such complexes, proving successful as therapeutics against previously undruggable targets. The C-terminal to LisH (CTLH) complex, also called the glucose-induced degradation deficient (GID) complex, is a multi-subunit E3 ligase complex highly conserved from Saccharomyces cerevisiae to humans, with roles in fundamental pathways controlling homeostasis and development in several species. However, we are only beginning to understand its mechanistic basis. Here, we review the literature of the CTLH complex from all organisms and place previous findings on individual subunits into context with recent breakthroughs on its structure and function.

A comprehensive bioinformatic analysis of RanBP9 expression and its relation to prognosis in human breast cancer

Aim: To explore the role of RanBP9 in breast cancer. Materials & methods: Oncomine, TIMER, GEPIA, UALCAN, c-BioPortal databases and tissue microarray analysis were used in this study. Results: The expression level of RanBP9 is elevated in breast cancer tissues, which is associated with poor prognosis in breast cancer patients. RanBP9 exhibits genetic alterations and a decreased methylation level in cancer tissues. RanBP9 may also regulate cell cycle progression and is linked to tumor purity and the infiltrating levels of immune cells. Conclusions: RanBP9 may correlate with prognosis and immune infiltration in breast cancer, laying the foundation for future studies on the potential role of RanBP9 in breast cancer.

Aspirin inhibits platelets from reprogramming breast tumor cells and promoting metastasis

It is now recognized that compounds released from tumor cells can activate platelets, causing the release of platelet-derived factors into the tumor microenvironment. Several of these factors have been shown to directly promote neovascularization and metastasis, yet how the feedback between platelet releasate and the tumor cell affects metastatic phenotype remains largely unstudied. Here, we identify that breast tumor cells secrete high levels of interleukin 8 (IL-8, CXCL8) in response to platelet releasate, which promotes their invasive capacity. Furthermore, we found that platelets activate the Akt pathway in breast tumor cells, and inhibition of this pathway eliminated IL-8 production. We therefore hypothesized inhibiting platelets with aspirin could reverse the prometastatic effects of platelets on tumor cell signaling. Platelets treated with aspirin did not activate the Akt pathway, resulting in reduced IL-8 secretion and impaired tumor cell invasion. Of note, patients with breast cancer receiving aspirin had lower circulating IL-8, and their platelets did not increase tumor cell invasion compared with patients not receiving aspirin. Our data suggest platelets support breast tumor metastasis by inducing tumor cells to secrete IL-8. Our data further support that aspirin acts as an anticancer agent by disrupting the communication between platelets and breast tumor cells.