Single Crystal X-ray Diffraction Studies of Two Polymorphic Modifications of the Dicarbonyl--Semiquinonato Rhodium Complex at Different Temperatures. Destruction Stimulated by Cooling Versus Stability.

It was found that the dicarbonyl-rhodium--semiquinonate complex (which thread-like crystals can bend reversibly under light/warm activation) can form two polymorphic modifications: isometric prisms () and sticks (). Some thin sticks can bend as mentioned above. X-ray diffraction studies of polymorphic modifications at different temperatures were carried out.

Novel dioxolene nickel complexes with sterically hindered diazabutadienes. Coupling of aza-ligands coordinated to nickel.

A square-planar bis-o-semiquinonato nickel complex interacts with N,N'-disubstituted 1,4-diazabutadienes-1,3 forming six-coordinate compounds. The X-ray structural study indicates complex geometry to be close to the octahedral. Magnetic properties are determined by metal-ligand ferromagnetic exchange interactions which are promoted by complex geometry.

Ferromagnetic Coupling in the Heterospin Bis-Catecholato-Manganese(IV) Complex with Pyridine Substituted by Nitronyl-nitroxide.

A new bis(3,6-di-tert-butyl-catecholato)manganese complex with two 4-NIT-Py ligands was synthesized and characterized [4-NIT-Py = pyridine substituted at position 4 with nitronyl-nitroxide radical, 2-(pyridin-4-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl]. X-ray diffraction indicated an octahedral environment of the manganese atom with a trans arrangement of ligands. Bonds lengths in the inner coordination core of the metal and in the chelate cycles that are representative of the charge distribution between the metal and ligands displayed a Mn(IV)(Cat) charge distribution.

ERBB2 overexpression suppresses stress-induced autophagy and renders ERBB2-induced mammary tumorigenesis independent of monoallelic Becn1 loss.

Defective autophagy has been implicated in mammary tumorigenesis, as the gene encoding the essential autophagy regulator BECN1 is deleted in human breast cancers and Becn1(+/-) mice develop mammary hyperplasias. In agreement with a recent study, which reports concurrent allelic BECN1 loss and ERBB2 amplification in a small number of human breast tumors, we found that low BECN1 mRNA correlates with ERBB2-overexpression in breast cancers, suggesting that BECN1 loss and ERBB2 overexpression may functionally interact in mammary tumorigenesis. We now report that ERBB2 overexpression suppressed autophagic response to stress in mouse mammary and human breast cancer cells.