Study of the CD95-Mediated Non-apoptotic Signaling Pathway: PI3K.

CD95 is a plasma membrane receptor that belongs to the TNF receptor family (Itoh and Nagata, J Biol Chem 268(15):10932-10937, 1993; Trauth et al., Science 245(4915):301-305, 1989). Accumulating evidence indicate that this so-called death receptor can also trigger non-apoptotic signaling pathways promoting inflammation and oncogenesis (Barnhart et al.

The cleaved FAS ligand activates the Na(+)/H(+) exchanger NHE1 through Akt/ROCK1 to stimulate cell motility.

Transmembrane CD95L (Fas ligand) can be cleaved to release a promigratory soluble ligand, cl-CD95L, which can contribute to chronic inflammation and cancer cell dissemination. The motility signaling pathway elicited by cl-CD95L remains poorly defined. Here, we show that in the presence of cl-CD95L, CD95 activates the Akt and RhoA signaling pathways, which together orchestrate an allosteric activation of the Na(+)/H(+) exchanger NHE1.

Review of PI3K/mTOR Inhibitors Entering Clinical Trials to Treat Triple Negative Breast Cancers.

Background: Constitutive activation of the PI3K/mTOR signaling pathway is observed in most, if not all, breast cancers. Accordingly, many PI3K and/or mTOR inhibitors have entered clinical trials, and completed studies should soon reveal the efficacy of these new drug families in the treatment of cancer patients.

Objective: We present the PI3K/Akt/mTOR signaling pathway and the structure and the anti-tumor efficiency of some mTOR inhibitors such as rapalogues and competitive inhibitors, which have entered clinical trials.

A Novel Covalent mTOR Inhibitor, DHM25, Shows in Vivo Antitumor Activity against Triple-Negative Breast Cancer Cells.

Constitutive activation of the PI3K/mTOR signaling pathway contributes to carcinogenesis and metastasis in most, if not all, breast cancers. From a chromene backbone reported to inhibit class I PI3K catalytic subunits, several rounds of chemical syntheses led to the generation of a new collection of chromologues that showed enhanced ability to kill PI3K-addicted cancer cells and to inhibit Akt phosphorylation at serine 473, a hallmark of PI3K/mTOR activation. This initial screen uncovered a chromene designated DHM25 that exerted potent antitumor activity against breast tumor cell lines.

The CD95/CD95L signaling pathway: a role in carcinogenesis.

Apoptosis is a fundamental process that contributes to tissue homeostasis, immune responses, and development. The receptor CD95, also called Fas, is a member of the tumor necrosis factor receptor (TNF-R) superfamily. Its cognate ligand, CD95L, is implicated in immune homeostasis and immune surveillance, and various lineages of malignant cells exhibit loss-of-function mutations in this pathway; therefore, CD95 was initially classified as a tumor suppressor gene.