Molecular Composition of Staufen2-Containing Ribonucleoproteins in Embryonic Rat Brain

Messenger ribonucleoprotein particles (mRNPs) are used to transport mRNAs along neuronal dendrites to their site of translation. Numerous mRNA-binding and regulatory proteins within mRNPs finely regulate the fate of bound-mRNAs. Their specific combination defines different types of mRNPs that in turn are related to specific synaptic functions. One of these mRNA-binding proteins, Staufen2 (Stau2), was shown to transport dendritic mRNAs along microtubules. Its knockdown expression in neurons was shown to change spine morphology and synaptic functions. To further understand the molecular mechanisms by which Stau2 modulates synaptic function in neurons, it is important to identify and characterize protein co-factors that regulate the fate of Stau2-containing mRNPs. To this end, a proteomic approach was used to identify co-immunoprecipitated proteins in Staufen2-containing mRNPs isolated from embryonic rat brains. The proteomic approach identified mRNA-binding proteins (PABPC1, hnRNP H1, YB1 and hsc70), proteins of the cytoskeleton (α- and β-tubulin) and RUFY3 a poorly characterized protein. While PABPC1 and YB1 associate with Stau2-containing mRNPs through RNAs, hsc70 is directly bound to Stau2 and this interaction is regulated by ATP. PABPC1 and YB1 proteins formed puncta in dendrites of embryonic rat hippocampal neurons. However, they poorly co-localized with Stau2 in the large dendritic complexes suggesting that they are rather components of Stau2-containing mRNA particles. All together, these results represent a further step in the characterization of Stau2-containing mRNPs in neurons and provide new tools to study and understand how Stau2-containing mRNPs are transported, translationally silenced during transport and/or locally expressed according to cell needs

Non-protein coding RNA biomarkers and differential expression in cancers: a review

<p>Abstract</p> <p>Background</p> <p>In these years a huge number of human transcripts has been found that do not code for proteins, named non-protein coding RNAs. In most cases, small (miRNAs, snoRNAs) and long RNAs (antisense RNA, dsRNA, and long RNA species) have many roles, functioning as regulators of other mRNAs, at transcriptional and post-transcriptional level, and controlling protein ubiquitination and degradation. Various species of npcRNAs have been found differentially expressed in different types of cancer. This review discusses the published data and new results on the expression of a subset of npcRNAs.</p> <p>Conclusion</p> <p>These results underscore the complexity of the RNA world and provide further evidence on the involvement of functional RNAs in cancer cell growth control.</p

Knockdown of p180 Eliminates the Terminal Differentiation of a Secretory Cell Line

We have previously reported that the expression in yeast of an integral membrane protein (p180) of the endoplasmic reticulum (ER), isolated for its ability to mediate ribosome binding, is capable of inducing new membrane biogenesis and an increase in secretory capacity. To demonstrate that p180 is necessary and sufficient for terminal differentiation and acquisition of a secretory phenotype in mammalian cells, we studied the differentiation of a secretory cell line where p180 levels had been significantly reduced using RNAi technology and by transiently expressing p180 in nonsecretory cells. A human monocytic (THP-1) cell line, that can acquire macrophage-like properties, failed to proliferate rough ER when p180 levels were lowered. The Golgi compartment and the secretion of apolipoprotein E (Apo E) were dramatically affected in cells expressing reduced p180 levels. On the other hand, expression of p180 in a human embryonic kidney nonsecretory cell line (HEK293) showed a significant increase in proliferation of rough ER membranes and Golgi complexes. The results obtained from knockdown and overexpression experiments demonstrate that p180 is both necessary and sufficient to induce a secretory phenotype in mammalian cells. These findings support a central role for p180 in the terminal differentiation of secretory cells and tissues

Clinical Outcomes and Toxic Effects of Single-Agent Immune Checkpoint Inhibitors among Patients Aged 80 Years or Older with Cancer: A Multicenter International Cohort Study

Importance: Geriatric (aged 6580 years) patients are historically underrepresented in cancer clinical trials. Little is known about the efficacy of immune checkpoint inhibitors (ICIs) in geriatric patients. These agents are associated with immune-related adverse events (irAEs), which may be particularly associated with morbidity in this population. Objective: To provide insight into the clinical outcomes and safety of ICIs among geriatric patients (aged 6580 years) with cancer. Design, Setting, and Participants: A Multicenter, international retrospective study of 928 geriatric patients with different tumors treated with single-agent ICIs between 2010 to 2019 from 18 academic centers in the US and Europe. Analyses were conducted from January 2021 to April 2021. Main Outcomes and Measures: Clinical outcomes and irAE patterns in geriatric patients treated with single-agent ICIs. Results: Median (range) age of the 928 patients at ICI initiation was 83.0 (75.8-97.0) years. Most patients (806 [86.9%]) were treated with anti-programmed cell death 1 therapy. Among the full cohort, the 3 most common tumors were non-small cell lung cancer (NSCLC, 345 [37.2%]), melanoma (329 [35.5%]), and genitourinary (GU) tumors (153 [16.5%]). Objective response rates for patients with NSCLC, melanoma, and GU tumors were 32.2%, 39.3%, and 26.2%, respectively. Median PFS and OS, respectively, were 6.7 and 10.9 months (NSCLC), 11.1 and 30.0 months (melanoma), and 6.0 and 15.0 months (GU). Within histologically specific subgroups (NSCLC, melanoma, and GU), clinical outcomes were similar across age subgroups (aged &lt;85 vs 6585 years). Among all 928 patients, 383 (41.3%) experienced 651 irAE(s), including 113 (12.2%) that were reported to be grade (G) 3 to 4 based on Common Terminology Criteria for Adverse Events (version 5.0). The median time to irAE onset was 9.8 weeks; 219 (57%) occurred within the first 3 months after ICI initiation. Discontinuation of treatment with ICIs owing to irAEs occurred in 137 (16.1%) patients. There was no significant difference in the rate of irAEs among patients aged younger than 85, 85 to 89, and 90 years or older. Despite the similar rate of G3 or higher irAEs, ICIs were discontinued due to irAEs more than twice as often among patients aged 90 years or older compared with patients younger than 90 years (30.9% vs 15.1%, P =.008). Conclusions and Relevance: The findings of this international cohort study suggest that treatment with ICIs may be effective and generally well tolerated among older patients with cancer, though ICI discontinuation owing to irAEs was more frequent with increasing age