Molecular Insights into the Recruiting Between UCP2 and DDX5/UBAP2L in the Metabolic Plasticity of Non-Small-Cell Lung Cancer

UCP2 promotes NSCLC proliferation and glycolysis via the mTOR/HIF-1α signaling

BACKGROUND

Metabolic disturbance is a hallmark of cancers. Targeting key metabolic pathways and metabolism-related molecular could be a potential therapeutic approach. Uncoupling protein 2 (UCP2) plays a pivotal part in the malignancy of cancer and its capacity to develop resistance to pharmaceutical interventions. However, it is unclear about the mechanism of how UCP2 acts in the tumor growth and metabolic reprogramming process in non-small cell lung cancer (NSCLC).

METHODS

Here, we conducted qRT-PCR to investigate the expression of UCP2 in both NSCLC tissues and cell lines. Subsequent functional studies including colony formation assay, CCK-8 assay, and glycolysis assay were conducted to investigate the functions of UCP2 in NSCLC. The regulatory mechanism of UCP2 toward the mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1 alpha (HIF-1α) signaling in NSCLC was confirmed through western blotting.

RESULTS

We observed a significant upregulation of UCP2 in both NSCLC tissues and cell lines. The increased expression of UCP2 has a strong association with a worse outlook. Silencing UCP2 remarkably dampened NSCLC cell proliferation and glycolysis capacities. Mechanically, UCP2 promoted NSCLC tumorigenesis partially via regulating the mTOR/HIF-1α axis.

CONCLUSION

Taken together, we explored the functions as well as the mechanisms of the UCP2/mTOR/HIF-1α axis in NSCLC progression, uncovering potential biological signatures and targets for NSCLC treatment.

Molecular insights into the inhibition mechanism of harringtonine against essential proteins associated with SARS-CoV-2 entry

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently posed a serious threat to global public health. Harringtonine (HT), as a small-molecule antagonist, has antiviral activity against a variety of viruses. There is evidence that HT can inhibit the SARS-CoV-2 entry into host cells by blocking the Spike protein and transmembrane protease serine 2 (TMPRSS2). However, the molecular mechanism underlying the inhibition effect of HT is largely elusive. Here, docking and all-atom molecular dynamic simulations were used to investigate the mechanism of HT against the receptor binding domain (RBD) of Spike, TMPRSS2, as well as the complex of RBD and angiotensin-converting enzyme 2 complex (RBD-ACE2). The results reveal that HT binds to all proteins primarily through hydrogen bond and hydrophobic interactions. Binding with HT influences the structural stability and dynamic motility processes of each protein. The interactions of HT with residues N33, H34 and K353 of ACE2, and residue K417 and Y453 of RBD contribute to disrupting the binding affinity between RBD and ACE2, which may hinder the virus entry into host cells. Our research provides molecular insights into the inhibition mechanism of HT against SARS-CoV-2 associated proteins, which will help for the novel antiviral drugs development.

Identification of Potential Lead Compounds Targeting Novel Druggable Cavity of SARS-CoV-2 Spike Trimer by Molecular Dynamics Simulations

The global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become an urgent public health problem. Spike (S) protein mediates the fusion between the virus and the host cell membranes, consequently emerging as an important target of drug design. The lack of comparisons of in situ full-length S homotrimer structures in different states hinders understanding the structures and revealing the function, thereby limiting the discovery and development of therapeutic agents. Here, the steady-state structures of the in situ full-length S trimer in closed and open states (Sclosed and Sopen) were modeled with the constraints of density maps, associated with the analysis of the dynamic structural differences. Subsequently, we identified various regions with structure and property differences as potential binding pockets for ligands that promote the formation of inactive trimeric protein complexes. By using virtual screening strategy and a newly defined druggable cavity, five ligands were screened with potential bioactivities. Then molecular dynamic (MD) simulations were performed on apo protein structures and ligand bound complexes to reveal the conformational changes upon ligand binding. Our simulation results revealed that sulforaphane (SFN), which has the best binding affinity, could inhibit the conformational changes of S homotrimer that would occur during the viral membrane fusion. Our results could aid in the understanding of the regulation mechanism of S trimer aggregation and the structure-activity relationship, facilitating the development of potential antiviral agents.

DDX5 and DDX17—multifaceted proteins in the regulation of tumorigenesis and tumor progression

DEAD-box (DDX)5 and DDX17, which belong to the DEAD-box RNA helicase family, are nuclear and cytoplasmic shuttle proteins. These proteins are expressed in most tissues and cells and participate in the regulation of normal physiological functions; their abnormal expression is closely related to tumorigenesis and tumor progression. DDX5/DDX17 participate in almost all processes of RNA metabolism, such as the alternative splicing of mRNA, biogenesis of microRNAs (miRNAs) and ribosomes, degradation of mRNA, interaction with long noncoding RNAs (lncRNAs) and coregulation of transcriptional activity. Moreover, different posttranslational modifications, such as phosphorylation, acetylation, ubiquitination, and sumoylation, endow DDX5/DDX17 with different functions in tumorigenesis and tumor progression. Indeed, DDX5 and DDX17 also interact with multiple key tumor-promoting molecules and participate in tumorigenesis and tumor progression signaling pathways. When DDX5/DDX17 expression or their posttranslational modification is dysregulated, the normal cellular signaling network collapses, leading to many pathological states, including tumorigenesis and tumor development. This review mainly discusses the molecular structure features and biological functions of DDX5/DDX17 and their effects on tumorigenesis and tumor progression, as well as their potential clinical application for tumor treatment.

Ubiquitin Binding Protein 2-Like (UBAP2L): is it so NICE After All?

Ubiquitin Binding Protein 2-like (UBAP2L, also known as NICE-4) is a ubiquitin- and RNA-binding protein, highly conserved in metazoans. Despite its abundance, its functions have only recently started to be characterized. Several studies have demonstrated the crucial involvement of UBAP2L in various cellular processes such as cell cycle regulation, stem cell activity and stress-response signaling. In addition, UBAP2L has recently emerged as a master regulator of growth and proliferation in several human cancers, where it is suggested to display oncogenic properties. Given that this versatile protein is involved in the regulation of multiple and distinct cellular pathways, actively contributing to the maintenance of cell homeostasis and survival, UBAP2L might represent a good candidate for future therapeutic studies. In this review, we discuss the current knowledge and latest advances on elucidating UBAP2L cellular functions, with an aim to highlight the importance of targeting UBAP2L for future therapies.