Publications by authors named "A Hamai"

Background: The unmet needs of managing patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer who progress after cyclin-dependent kinase (CDK)4/6 inhibitor (CDK4/6i) treatment remain unclarified.

Methods: This was a phase 1b/2, single-arm, open-label study that enrolled 29 patients with HR+/HER2- breast cancer who experienced first-line palbociclib treatment failure. The primary endpoint was the incidence of dose-limiting toxicity (DLT).

View Article and Find Full Text PDF

Lipids, which are highly diverse, are finely distributed between organelle membranes and the plasma membrane (PM) of eukaryotic cells. As a result, each compartment has its own lipid composition and molecular identity, which is essential for the functional fate of many proteins. This distribution of lipids depends on two main processes: lipid synthesis, which takes place in different subcellular regions, and the transfer of these lipids between and across membranes.

View Article and Find Full Text PDF

As an important immune stimulator and modulator, IFNγ is crucial for gut homeostasis and its dysregulation links to diverse colon pathologies, such as colitis and colorectal cancer (CRC). Here, we demonstrated that the epigenetic regulator, CBX3 (also known as HP1γ) antagonizes IFNγ signaling in the colon epithelium by transcriptionally repressing two critical IFNγ-responsive genes: STAT1 and CD274 (encoding Programmed death-ligand 1, PD-L1). Accordingly, CBX3 deletion resulted in chronic mouse colon inflammation, accompanied by upregulated STAT1 and CD274 expressions.

View Article and Find Full Text PDF

Oxysterol-binding protein-related proteins (ORPs) play key roles in the distribution of lipids in eukaryotic cells by exchanging sterol or phosphatidylserine for PI4P between the endoplasmic reticulum (ER) and other cell regions. However, it is unclear how their exchange capacity is coupled to PI4P metabolism. To address this question quantitatively, we analyze the activity of a representative ORP, Osh4p, in an ER/Golgi interface reconstituted with ER- and Golgi-mimetic membranes functionalized with PI4P phosphatase Sac1p and phosphatidylinositol (PI) 4-kinase, respectively.

View Article and Find Full Text PDF