Dissecting the role of zyxin as a mediator of aggressiveness in Ewing sarcoma

Zyxin is a phosphoprotein localized at the focal adhesions and on the actin stress fibres, where it regulates the cytoskeleton organization. In addition, zyxin can shift into the nucleus and modulates the gene expression, affecting key cellular processes. Consequently, zyxin is as a crucial factor in the malignancy of several cancers, like Ewing sarcoma (EWS). EWS is a rare tumour of the bones, affecting children and adolescents. The main features of EWS are the presence of a chimeric transcriptional factor, EWS-FLI1 and the high expression of CD99, a glycoprotein necessary for the maintenance of the malignant phenotype. Triggering of CD99 with specific antibodies causes massive cell death, an effect that requires zyxin presence. In EWS zyxin is repressed by EWS-FLI1 and its forced re-expression counteracts the malignant phenotype. In this work we decided to deepen our knowledge on how zyxin affects EWS malignancy. We proved that zyxin is a negative regulator of cell migration, survival and growth in anchorage-independent conditions, confirming the tumour suppressor role of zyxin. Then we focused on the relation between CD99 and zyxin. Loss of function of CD99, by engagement with specific antibodies or use of shRNA, increases zyxin levels and promotes its nuclear translocation. Here, we observed that zyxin impairs the transcriptional activity of the Glioma associated oncogene 1 (Gli1), a member of the Hedgehog signalling pathway, which has a relevant oncogenic function in EWS. To support these evidences, we also reported that the loss of function of CD99 inhibits, trough zyxin mediation, the expression of Gli1 up-regulated target genes, such as NKX2-2, PTCH1 and cyclins, whilst enhances the expression of its down-regulated target GAS1. In conclusion, we presented a more accurate depiction of zyxin role in EWS, which in the future could be further developed in hope to offer new therapeutic approaches.

Convergent bioenergetic defects in Coenzyme Q10 depleted cells by pharmacological inhibition of coq2 enzyme (p-hydroxybenzoate polyprenyl transferase) and by genome editing technology targeting the encoding gene (COQ2)

Primary CoQ10 deficiency diseases encompass a heterogeneous spectrum of clinical phenotypes. Among these, defect or mutation on COQ2 gene, encoding a para-hydroxybenzoate polyprenyl transferase, have been associated with different diseases. Understanding the functional and metabolic impact of COQ2 mutation and the consequent CoQ10 deficiency is still a matter of debate. To date the aetiology of the neurological phenotypes correlated to CoQ10 deficiency does not present a clear genotype-phenotype association. In addition to the metabolic alterations due to Coenzyme Q depletion, the impairment of mitochondrial function, associated with the reduced CoQ level, could play a significant role in the metabolic flexibility of cancer. This study aimed to characterize the effect of varying degrees of CoQ10 deficiency and investigate the multifaceted aspect of CoQ10 depletion and its impact on cell metabolism. To induced CoQ10 depletion, different cell models were used, employing a chemical and genome editing approach. In T67 and MCF-7 CoQ10 depletion was achieved by a competitive inhibitor of the enzyme, 4-nitrobenzoate (4-NB), whereas in SH-SY5Y the COQ2 gene was edited via CRISPR-Cas9 cutting edge technology.

Exercise associated factors affecting cardiovascular health and function: from myocyte signaling to genetic variations

The exact mechanisms of the exercise induced adaptations is not lucid, but recent studies have delineated two means of signaling by which the adaptations occur (1) substrate availability signaling (metabolic stress) (2) hormone-receptor signaling. We have decided to specifically investigate two metabolic signaling enzymes [AMP-activated kinase (AMPK) and Sirtuin 1(SIRT1)] and two hormones [Adiponectin and Adrenergic stimulation].Tis based on four papers with the following conclusions: (1)Increase in SIRT1 activity and expression in H9c2 cells treated with phenylephrine is an adaptive response to the hypertrophic stress, mediated by AMPK. (2)The lack of optimal nutritional conditions (energetic substrates) due to a prolonged activation of AMPK can contrast the establishment of hypertrophy, possibly also by means of the negative modulation of ODC activity. (3) Our findings offer a possibile hypothesis as to the fact the the G allele on site 45 could lead to the increasd risk of Type II diabetes through a decrease in lean body mass. (4) Our results suggest that there is an ADIPOQ gene effect in relation to bone parameters. Statistical analysis show that the presence of the T allele in position 45 favors an increase in lumbar spine bone mineral content (BMC) when compared to subjects with a G allele substitution, which can be do the the increase in lean body mass in this genotype group.