The claims that 3,4,7,8‐tetraphenyl‐1,2,5,6‐tetraazocine can be prepared by the thermal condensation of two moles of benzil monohydrazone or of an equimolar mixture of benzil and benzil dihydrazone have been thoroughly reinvestigated. When such thermolyses were conducted in moist air, neither the claimed 3,4,7,8‐tetraphenyl‐1,2,5,6‐tetraazocine nor the precedented isomeric tetraazapentalene derivative was detected. The following products were unambiguously formed from the heating of molten benzil monohydrazone (%): benzil (10), benzaldehyde (10), benzamide (22), benzyl phenyl ketone (19), benzil bis(ketazine) (11), 3,4,5,6‐tetraphenylpyridazine (9), benzil benzaldehyde azine (10), and, after column chromatography, 2,4,5‐triphenylimidazole (2). This last component had a melting point and the fluorescent properties in UV light attributed by the original investigator to the mistakenly presumed 3,4,7,8‐tetraphenyl‐1,2,5,6‐tetraazocine. Thus, the original claims for the synthesis of such a novel tetraazocine ring or even for the synthesis of the precedented isomeric zwitterionic tetraazapentalene have now been repudiated. The formation of 2,4,5‐triphenylimidazole as a side reaction in the thermolysis of benzil monohydrazone can readily be rationalized as arising from benzil, benzaldehyde, and a source of ammonia, namely, benzamide, in the long‐known Radziszewski reaction. Corroborating evidence was provided by data from the thermolysis of benzil dihydrazone. In addition, the origin of other side products is explained in terms of other possible condensations. Finally, preliminary experiments on using irreversible dehydrating agents such as titanium(IV) isopropoxide with benzil monohydrazone indicate that 3,4,7,8‐tetraphenyl‐1,2,5,6‐tetraazocine is formed at room temperature as a transitory intermediate, which eliminates dinitrogen to produce 3,4,5,6‐tetraphenylpyridazine.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Tumor heterogeneity may arise through genetic drift and environmentally driven clonal selection for metabolic fitness. This would promote subpopulations derived from single cancer cells that exhibit distinct phenotypes while conserving vital pro-survival pathways. We aimed to identify significant drivers of cell fitness in pancreatic adenocarcinoma (PDAC) creating subclones in different nutrient formulations to encourage differential metabolic reprogramming. The genetic and phenotypic expression profiles of each subclone were analyzed relative to a healthy control cell line (hTert-HPNE). The subclones exhibited distinct variations in protein expression and lipid metabolism. Relative to hTert-HPNE, PSN-1 subclones uniformly maintained modified sphingolipid signaling and specifically retained elevated sphingosine-1-phosphate (S1P) relative to C16 ceramide (C16 Cer) ratios. Each clone utilized a different perturbation to this pathway, but maintained this modified signaling to preserve cancerous phenotypes, such as rapid proliferation and defense against mitochondria-mediated apoptosis. Although the subclones were unique in their sensitivity, inhibition of S1P synthesis significantly reduced the ratio of S1P/C16 Cer, slowed cell proliferation, and enhanced sensitivity to apoptotic signals. This reliance on S1P signaling identifies this pathway as a promising drug-sensitizing target that may be used to eliminate cancerous cells consistently across uniquely reprogrammed PDAC clones.

This study investigates whether selected WD40 proteins with a 7-bladed β-propeller structure, similar to that of the β subunit of the G protein heterotrimer, interact with the cytosolic chaperonin CCT and its known binding partner, PhLP1. Previous studies have shown that CCT is required for the folding of the Gβ subunit and other WD40 proteins. The role of PhLP1 in the folding of Gβ has also been established, but it is unknown if PhLP1 assists in the folding of other Gβ-like proteins. The binding of three Gβ-like proteins, TBL2, MLST8 and CDC20, to CCT and PhLP1, was demonstrated in this study. Co-immunoprecipitation assays identified one novel binding partner for CCT and three new interactors for PhLP1. All three of the studied proteins interact with CCT and PhLP1, suggesting that these proteins may have a folding machinery in common with that of Gβ and that the well-established Gβ folding mechanism may have significantly broader biological implications than previously thought. These findings contribute to continuous efforts to determine common traits and unique differences in the folding mechanism of the WD40 β-propeller protein family, and the role PhLP1 has in this process.

The goal of this study is to identify mechanisms by which the oncogenic tyrosine kinase receptor HER2 promotes the growth and metastasis of breast cancer. Previously published work suggests that the phospho-binding protein 14-3-3ζ, which is highly expressed in a variety of breast cancer subtypes, promotes HER2-mediated oncogenic signaling. In this study, we hypothesized that 14-3-3ζ sustains HER2 signaling by binding to and modulating a network of proteins that are phosphorylated downstream of HER2 activation. Using proteomics as a tool to identify 14-3-3ζ interacting proteins in HER2+ breast cancer cells treated with or without Lapatinib (HER2 inhibitor), we identified a subset HER2-dependent 14-3-3ζ interacting proteins. We have focused our current effort on one of these proteins, SH3BP4, which plays a critical role in controlling mTOR activation. We have identified a nutrient-sensitive phosphorylation within a putative 14-3-3ζ binding site on SH3BP4 and we are currently working to understand its mechanism of regulation and impact on mTOR-mediated growth signaling downstream of HER2. Citation Format: Tsz Yin Chan, Courtney Banks, Bennet Peterson, Joshua Andersen. 14-3-3z-mediated oncogenic signaling downstream of HER2 in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4568.

The lymphoblastic leukemia ‐ 1 (LYL1) gene is a transcription factor believed, when upregulated, to support the formation of T‐cell Acute Lymphoblastic Leukemia (TALL). One possible cause for the upregulation of LYL1 is the presence of mutations, affecting the normal expression, processing or degradation of LYL1. The objective of our study is to identify if there are mutations in the LYL1 gene in patients with TALL, and determine the effect of such mutations on LYL1 expression. RNA, for quantitative PCR, and DNA, for LYL1 sequencing, were extracted from blood and bone marrow samples from twenty TALL patients. Ten samples showed high and intermediate LYL1 expression. Five of them had single nucleotide polymorphism with three of them being non‐silent. LYL1 variants with single or combined mutations were constructed, and their expression, in cultured CHO‐K1 and H441, was measured by western blotting. The LYL1 variants showed significantly increased expression, up to 3.6 fold, compared to the wild type form. Our findings suggest that these mutations may have a role in the expression and processing, or the degradation of LYL1, which not only adds to our understanding of the LYL1 biology, but it may offer one more clue why LYL1 is upregulated in some forms of TALL. Grant Funding Source: BYUH Mentored Research & Student Research Associateship Funds