SMURF1 Plays a role in EGF-induced breast cancer cell migration and invasion

Epidermal growth factor (EGF) is a well-known growth factor that induces cancer cell migration and invasion. Previous studies have shown that SMAD ubiquitination regulatory factor 1 (SMURF1), an E3 ubiquitin ligase, regulates cell motility by inducing RhoA degradation. Therefore, we examined the role of SMURF1 in EGF-induced cell migration and invasion using MDA-MB-231 cells, a human breast cancer cell line. EGF increased SMURF1 expression at both the mRNA and protein levels. All ErbB family members were expressed in MDA-MB-231 cells and receptor tyrosine kinase inhibitors specific for the EGF receptor (EGFR) or ErbB2 blocked the EGF-mediated induction of SMURF1 expression. Within the signaling pathways examined, ERK1/2 and protein kinase C activity were required for EGF-induced SMURF1 expression. The overexpression of constitutively active MEK1 increased the SMURF1 to levels similar to those induced by EGF. SMURF1 induction by EGF treatment or by the overexpression of MEK1 or SMURF1 resulted in enhanced cell migration and invasion, whereas SMURF1 knockdown suppressed EGF- or MEK1-induced cell migration and invasion. EGF treatment or SMURF1 overexpression decreased the endogenous RhoA protein levels. The overexpression of constitutively active RhoA prevented EGF- or SMURF1-induced cell migration and invasion. These results suggest that EGFinduced SMURF1 plays a role in breast cancer cell migration and invasion through the downregulation of RhoA.     

Synthesis and Application of C2 and C3 Symmetric (R)‐Phenylglycinol‐Derived Chiral Stationary Phases

A C3 symmetric (R)‐phenylglycinol N‐1,3,5‐benzenetricarboxylic acid‐derived chiral stationary phase (CSP) and three C2 symmetric (R)‐phenylglycinol CSPs were newly synthesized using o‐, m‐, and p‐phthaloyl dichlorides. © 2016 Wiley Periodicals, Inc. These CSPs were used to compare the resolution of 25 chiral samples using a previously reported 3,5‐dinitrobenzoyl (R)‐phenylglycinol‐derived CSP. Even though all CSPs have the same chiral moiety, the C3 symmetric CSP showed the best resolution. Chirality 28:186–191, 2016.© 2016 Wiley Periodicals, Inc.     

Apoptotic cells can induce compensatory cell proliferation through the JNK and the Wingless signaling pathways

In many metazoans, damaged and potentially dangerous cells are rapidly eliminated by apoptosis. In Drosophila, this is often compensated for by extraproliferation of neighboring cells, which allows the organism to tolerate considerable cell death without compromising development and body size. Despite its importance, the mechanistic basis of such compensatory proliferation remains poorly understood. Here, we show that apoptotic cells express the secretory factors wingless (wg) and decapentaplegic (dpp). When cells undergoing apoptosis were kept alive with the caspase inhibitor p35, excessive nonautonomous cell proliferation was observed. Significantly, wg signaling is necessary and, at least in some cells, also sufficient for mitogenesis under these conditions. Finally, we provide evidence that the DIAP1 antagonists reaper and hid can activate the JNK pathway and that this pathway is required for inducing wg and cell proliferation. These findings support a model where apoptotic cells activate signaling cascades for compensatory proliferation.     

Immunocytochemical localization of neurons containing the AMPA GluR2/3 subunit in the hamster visual cortex

AMPA glutamate receptors play a crucial role in brain functions such as synaptic plasticity and development. We have studied the chemo-architecture of the AMPA glutamate receptor subtype GluR2/3 in the hamster visual cortex by immunocytochemistry and compared it with the distribution of the calcium-binding proteins, calbindin D28K and calretinin. Anti-GluR2/3-immunoreactive (IR) neurons were predominantly located in layers II/III, V, and VI, and the majority of the labeled neurons were round or oval. However, many pyramidal cells in layer V were also labeled. Two-color immunofluorescence revealed that none of the GluR2/3-IR neurons contained calbindin D28 K or calretinin. Thus specific layers of neurons express the GluR2/3 subunit and these do not correlate with expression of calbindin D28K and calretinin.