Ribosomal stalk proteins RPLP1 and RPLP2 promote biogenesis of flaviviral and cellular multi-pass transmembrane proteins

Ribosome customization and functional diversification among P-stalk proteins regulate late poxvirus protein synthesis

Growing evidence suggests that ribosomes selectively regulate translation of specific mRNA subsets. Here, quantitative proteomics and cryoelectron microscopy demonstrate that poxvirus infection does not alter ribosomal subunit protein (RP) composition but skews 40S rotation states and displaces the 40S head domain. Genetic knockout screens employing metabolic assays and a dual-reporter virus further identified two RPs that selectively regulate non-canonical translation of late poxvirus mRNAs, which contain unusual 5' poly(A) leaders: receptor of activated C kinase 1 (RACK1) and RPLP2. RACK1 is a component of the altered 40S head domain, while RPLP2 is a subunit of the P-stalk, wherein RPLP0 anchors two heterodimers of RPLP1 and RPLP2 to the large 60S subunit. RPLP0 was required for global translation, yet RPLP1 was dispensable, while RPLP2 was specifically required for non-canonical poxvirus protein synthesis. From these combined results, we demonstrate that poxviruses structurally customize ribosomes and become reliant upon traditionally non-essential RPs from both ribosomal subunits for efficient initiation on their late mRNAs.

P-stalk ribosomes act as master regulators of cytokine-mediated processes

Inflammatory cytokines are pivotal to immune responses. Upon cytokine exposure, cells enter an "alert state" that enhances their visibility to the immune system. Here, we identified an alert-state subpopulation of ribosomes defined by the presence of the P-stalk. We show that P-stalk ribosomes (PSRs) are formed in response to cytokines linked to tumor immunity, and this is at least partially mediated by P-stalk phosphorylation. PSRs are involved in the preferential translation of mRNAs vital for the cytokine response via the more efficient translation of transmembrane domains of receptor molecules involved in cytokine-mediated processes. Importantly, loss of the PSR inhibits CD8+ T cell recognition and killing, and inhibitory cytokines like transforming growth factor β (TGF-β) hinder PSR formation, suggesting that the PSR is a central regulatory hub upon which multiple signals converge. Thus, the PSR is an essential mediator of the cellular rewiring that occurs following cytokine exposure via the translational regulation of this process.

Dengue NS1 interaction with lipids alters its pathogenic effects on monocyte derived macrophages

BACKGROUND

While dengue NS1 antigen has been shown to be associated with disease pathogenesis in some studies, it has not been linked in other studies, with the reasons remaining unclear. NS1 antigen levels in acute dengue are often associated with increased disease severity, but there has been a wide variation in results based on past dengue infection and infecting dengue virus (DENV) serotype. As NS1 engages with many host lipids, we hypothesize that the type of NS1-lipid interactions alters its pathogenicity.

METHODS

Primary human monocyte derived macrophages (MDMs) were co-cultured with NS1 alone or with HDL, LDL, LPS and/or platelet activating factor (PAF) from individuals with a history of past dengue fever (DF = 8) or dengue haemorrhagic fever (DHF = 8). IL-1β levels were measured in culture supernatants, and gene expression analysis carried out in MDMs. Monocyte subpopulations were assessed by flow cytometry. Hierarchical cluster analysis with Euclidean distance calculations were used to differentiate clusters. Differentially expressed variables were extracted and a classifier model was developed to differentiate between past DF and DHF.

RESULTS

Significantly higher levels of IL-1β were seen in culture supernatants when NS1 was co-cultured with LDL (p = 0.01, median = 45.69 pg/ml), but lower levels when NS1 was co-cultured with HDL (p = 0.05, median = 4.617 pg/ml). MDMs of those with past DHF produced higher levels of IL-1β when NS1 was co-cultured with PAF (p = 0.02). MDMs of individuals with past DHF, were significantly more likely to down-regulate RPLP2 gene expression when macrophages were co-cultured with either PAF alone, or NS1 combined with PAF, or NS1 combined with LDL. When NS1 was co-cultured with PAF, HDL or LDL two clusters were detected based on IL10 expression, but these did not differentiate those with past DF or DHF.

CONCLUSIONS

As RPLP2 is important in DENV replication, regulating cellular stress responses and immune responses and IL-10 is associated with severe disease, it would be important to further explore how differential expression of RPLP2 and IL-10 could lead to disease pathogenesis based on NS1 and lipid interactions.

Ribosome specialization in cancer: a spotlight on ribosomal proteins

In the past few decades, our view of ribosomes has changed substantially. Rather than passive machines without significant variability, it is now acknowledged that they are heterogeneous, and have direct regulatory capacity. This 'ribosome heterogeneity' comes in many flavors, including in both the RNA and protein components of ribosomes, so there are many paths through which ribosome specialization could arise. It is easy to imagine that specialized ribosomes could have wide physiological roles, through the translation of specific mRNA populations, and there is now evidence for this in several contexts. Translation is highly dysregulated in cancer, needed to support oncogenic phenotypes and to overcome cellular stress. However, the role of ribosome specialization in this is not clear. In this review we focus on specialized ribosomes in cancer. Specifically, we assess the impact that post-translational modifications and differential ribosome incorporation of ribosomal proteins (RPs) have in this disease. We focus on studies that have shown a ribosome-mediated change in translation of specific mRNA populations, and hypothesize how such a process could be driving other phenotypes. We review the impact of RP-mediated heterogeneity in both intrinsic and extrinsic oncogenic processes, and consider how this knowledge could be leveraged to benefit patients.

Decoding ribosome complexity: role of ribosomal proteins in cancer and disease

The ribosome is a remarkably complex machinery, at the interface with diverse cellular functions and processes. Evolutionarily conserved, yet intricately regulated, ribosomes play pivotal roles in decoding genetic information into the synthesis of proteins and in the generation of biomass critical for cellular physiological functions. Recent insights have revealed the existence of ribosome heterogeneity at multiple levels. Such heterogeneity extends to cancer, where aberrant ribosome biogenesis and function contribute to oncogenesis. This led to the emergence of the concept of 'onco-ribosomes', specific ribosomal variants with altered structural dynamics, contributing to cancer initiation and progression. Ribosomal proteins (RPs) are involved in many of these alterations, acting as critical factors for the translational reprogramming of cancer cells. In this review article, we highlight the roles of RPs in ribosome biogenesis, how mutations in RPs and their paralogues reshape the translational landscape, driving clonal evolution and therapeutic resistance. Furthermore, we present recent evidence providing new insights into post-translational modifications of RPs, such as ubiquitylation, UFMylation and phosphorylation, and how they regulate ribosome recycling, translational fidelity and cellular stress responses. Understanding the intricate interplay between ribosome complexity, heterogeneity and RP-mediated regulatory mechanisms in pathology offers profound insights into cancer biology and unveils novel therapeutic avenues targeting the translational machinery in cancer.

RPLP1 restricts HIV-1 transcription by disrupting C/EBPβ binding to the LTR

Long-term non-progressors (LTNPs) of HIV-1 infection may provide important insights into mechanisms involved in viral control and pathogenesis. Here, our results suggest that the ribosomal protein lateral stalk subunit P1 (RPLP1) is expressed at higher levels in LTNPs compared to regular progressors (RPs). Functionally, RPLP1 inhibits transcription of clade B HIV-1 strains by occupying the C/EBPβ binding sites in the viral long terminal repeat (LTR). This interaction requires the α-helixes 2 and 4 domains of RPLP1 and is evaded by HIV-1 group M subtype C and group N, O and P strains that do not require C/EBPβ for transcription. We further demonstrate that HIV-1-induced translocation of RPLP1 from the cytoplasm to the nucleus is essential for antiviral activity. Finally, knock-down of RPLP1 promotes reactivation of latent HIV-1 proviruses. Thus, RPLP1 may play a role in the maintenance of HIV-1 latency and resistance to RPLP1 restriction may contribute to the effective spread of clade C HIV-1 strains.

Dengue NS1 interaction with lipids alters its pathogenic effects on monocyte derived macrophages

Background

While dengue NS1 antigen has been shown to be associated with disease pathogenesis in some studies, it has not been linked in other studies, with the reasons remaining unclear. NS1 antigen levels in acute dengue are often associated with increased disease severity, but there have been a wide variation in results based on past dengue infection and infecting dengue virus (DENV) serotype. As NS1 engages with many host lipids, we hypothesize that the type of NS1-lipid interactions alters its pathogenicity.

Methods

Primary human monocyte derived macrophages (MDMs) were co-cultured with NS1 alone or with HDL, LDL, LPS and/or platelet activating factor (PAF) from individuals with a history of past dengue fever (DF=8) or dengue haemorrhagic fever (DHF=8). IL-1β levels were measured in culture supernatants, and gene expression analysis carried out in MDMs. Monocyte subpopulations were assessed by flow cytometry. Hierarchical cluster analysis with Euclidean distance calculations were used to differentiate clusters. Differentially expressed variables were extracted and a classifier model was developed to differentiate between past DF and DHF.

Results

Significantly higher levels of IL-1β were seen in culture supernatants when NS1 was co-cultured with LDL (p=0.01), but with lower levels with HDL (p=0.05). MDMs of those past DHF produced more IL-1β when NS1 with PAF (p=0.02). MDMs of individuals with past DHF, were significantly more likely to down-regulate RPLP2 gene expression when macrophages were co-cultured with either PAF alone, or NS1 combined with PAF, or NS1 combined with LDL. When NS1 was co-cultured with PAF, HDL or LDL two clusters were detected based on IL10 expression, but these did not differentiate those with past DF or DHF.

Conclusions

As RPLP2 is important in DENV replication and in regulating cellular stress responses and immune responses and IL-10 is associated with severe disease, it would be important to further explore how differential expression of RPLP2 and IL-10 could lead to disease pathogenesis based on NS1 and lipid interactions.

RNAi-Mediated Knockdown of Acidic Ribosomal Stalk Protein P1 Arrests Egg Development in Adult Female Yellow Fever Mosquitoes, Aedes aegypti

After taking a blood meal, the fat body of the adult female yellow fever mosquito, Aedes aegypti, switches from a previtellogenic state of arrest to an active state of synthesizing large quantities of yolk protein precursors (YPPs) that are crucial for egg development. The synthesis of YPPs is regulated at both the transcriptional and translational levels. Previously, we identified the cytoplasmic protein general control nonderepressible 1 (GCN1) as a part of the translational regulatory pathway for YPP synthesis. In the current study, we used the C-terminal end of GCN1 to screen for protein-protein interactions and identified 60S acidic ribosomal protein P1 (P1). An expression analysis and RNAi-mediated knockdown of P1 was performed to further investigate the role of P1 in mosquito reproduction. We showed that in unfed (absence of a blood meal) adult A. aegypti mosquitoes, P1 was expressed ubiquitously in the mosquito organs and tissues tested. We also showed that the RNAi-mediated knockdown of P1 in unfed adult female mosquitoes resulted in a strong, transient knockdown with observable phenotypic changes in ovary length and egg deposition. Our results suggest that 60S acidic ribosomal protein P1 is necessary for mosquito reproduction and is a promising target for mosquito population control.

RPLP2 activates TLR4 in an autocrine manner and promotes HIF-1α-induced metabolic reprogramming in hepatocellular carcinoma

Metabolic reprogramming is a major feature of cancer, and aerobic glycolysis is one of the most widely studied metabolic reprogramming processes. Acidic ribosome protein P2 (RPLP2) is associated with both tumorigenesis and endoplasmic reticulum stress. However, limited knowledge exists regarding the role of RPLP2 in hepatocellular carcinoma (HCC) progression. In the present study, we observed a significant upregulation of RPLP2 in HCC tissues. Moreover, RPLP2 expression is closely correlated with patient prognosis and survival. The subsequent experimental validation demonstrated that RPLP2 exerted a regulatory effect on the expression of glycolytic enzymes and lactate production, thereby facilitating HCC cell proliferation. Mechanistically, the PI3K/AKT signalling pathway was found to play an important role in the regulation of hypoxia-inducible factor-1α (HIF-1α)-mediated aerobic glycolysis and cell growth. RPLP2 activates TLR4 on the surface of HCC cells and the downstream PI3K/AKT pathway through autocrine signalling. This activation then facilitates the entry of HIF-1α into the nucleus, enabling it to fulfil its transcriptional function. In conclusion, our findings suggested that RPLP2 induces a metabolic shift towards aerobic glycolysis and facilitates the progression of HCC through TLR4-dependent activation of the PI3K/AKT/HIF-1α pathway. Our study revealed the novel mechanism by which the ribosomal protein RPLP2 regulates glycolysis to promote HCC progression. These findings may offer a potential therapeutic target for HCC treatment.

Dengue virus 3 genotype I (GI) lineage 1 (L1) isolates elicit differential cytopathic effect with syncytium formation in human glioblastoma cells (U251)

BACKGROUND

Dengue virus (DENV) is a Flaviviridae member classified into four antigenically distinct serotypes (DENV 1, 2, 3, and 4) and further subdivided genotypes. DENV3 is subdivided into four or five genotypes, depending on the classification adopted. Despite their high genetic proximity, as revealed by phylogenetic complete polyprotein analysis, DENV3 MG-20 and DENV3 PV_BR showed different neurovirulence in mice models. Our group identified six amino acid mutations in protein E, including the E62K and E123Q, which may affect interactions of hydrophobic clusters on domain II, thus leading to the observed differences in the studied viruses.

METHODS

Human glioblastoma cells (U251) derived from a malignant glioblastoma tumor by explant technique were infected by the DENV3 GIL1 isolates DENV3 MG-20 and DENV3 PV_BR and analyzed by plaque assays and titration, optical, immunofluorescence, and transmission electronic microscopy.

RESULTS

The two isolates showed different cytopathic effects (CPE) and fusogenic patterns, further confirmed by indirect immunofluorescence. Transmission electron microscopy revealed intense cytopathic effects in DENV3 MG-20 infected U251 cells, displaying endoplasmic reticulum hypertrophy and turgid vesicles with proteins and multiple viruses, distinct from DENV3 PV_BR infected cells. It is hypothesized that the different amino acids in the DENV3 MG-20 isolate are related to an increased membrane fusion ability in viral infection, thus facilitating immune system evasion and increased chances of central nervous system cell infection.

CONCLUSION

These results emphasize the biological differences between the isolates, which could be a critical factor in host-virus interaction and severe dengue development. Our study presents comparative results of highly similar isolates with the potential to generate more subsidies for a deeper understanding of the DENV pathogenesis. The neurotropism of the isolate DENV3 MG-20 (belonging to the DENV3 GI L1 genotype) showing infection of nervous system cells (U251) could contribute to understanding neurological dengue disease.

Proteomic screening identifies RPLp2 as a specific regulator for the translation of coronavirus

Viral mRNA of coronavirus translates in an eIF4E-dependent manner, and the phosphorylation of eIF4E can modulate this process, but the role of p-eIF4E in coronavirus infection is not yet entirely evident. p-eIF4E favors the translation of selected mRNAs, specifically the mRNAs that encode proteins associated with cell proliferation, inflammation, the extracellular matrix, and tumor formation and metastasis. In the present work, two rounds of TMT relative quantitative proteomics were used to screen 77 cellular factors that are upregulated upon infection by coronavirus PEDV and are potentially susceptible to a high level of p-eIF4E. PEDV infection increased the translation level of ribosomal protein lateral stalk subunit RPLp2 (but not subunit RPLp0/1) in a p-eIF4E-dependent manner. The bicistronic dual-reporter assay and polysome profile showed that RPLp2 is essential for translating the viral mRNA of PEDV. RNA binding protein and immunoprecipitation assay showed that RPLp2 interacted with PEDV 5'UTR via association with eIF4E. Moreover, the cap pull-down assay showed that the viral nucleocapsid protein is recruited in m⁷GTP-precipitated complexes with the assistance of RPLp2. The heterogeneous ribosomes, which are different in composition, regulate the selective translation of specific mRNAs. Our study proves that viral mRNA and protein utilize translation factors and heterogeneous ribosomes for preferential translation initiation. This previously uncharacterized process may be involved in the selective translation of coronavirus.

Construction of a prognostic model related to copper dependence in breast cancer by single-cell sequencing analysis

Purpose: To explore the clinical significance of copper-dependent-related genes (CDRG) in female breast cancer (BC).

Methods: CDRG were obtained by single-cell analysis of the GSE168410 dataset in the Gene Expression Omnibus (GEO) database. According to a 1:1 ratio, the Cancer Genome Atlas (TCGA) cohort was separated into a training and a test cohort randomly. Based on the training cohort, the prognostic model was built using COX and Lasso regression. The test cohort was used to validate the model. The GSE20685 dataset and GSE20711 dataset were used as two external validation cohorts to further validate the prognostic model. According to the median risk score, patients were classified as high-risk or low-risk. Survival analysis, immune microenvironment analysis, drug sensitivity analysis, and nomogram analysis were used to evaluate the clinical importance of this prognostic model.

Results: 384 CDRG were obtained by single-cell analysis. According to the prognostic model, patients were classified as high-risk or low-risk in both cohorts. The high-risk group had a significantly worse prognosis. The area under the curve (AUC) of the model was around 0.7 in the four cohorts. The immunological microenvironment was examined for a possible link between risk score and immune cell infiltration. Veliparib, Selumetinib, Entinostat, and Palbociclib were found to be more sensitive medications for the high-risk group after drug sensitivity analysis.

Conclusion: Our CDRG-based prognostic model can aid in the prediction of prognosis and treatment of BC patients.

CARs-DB: A Database of Cryptic Amyloidogenic Regions in Intrinsically Disordered Proteins

Proteome-wide analyses suggest that most globular proteins contain at least one amyloidogenic region, whereas these aggregation-prone segments are thought to be underrepresented in intrinsically disordered proteins (IDPs). In recent work, we reported that intrinsically disordered regions (IDRs) indeed sustain a significant amyloid load in the form of cryptic amyloidogenic regions (CARs). CARs are widespread in IDRs, but they are necessarily exposed to solvent, and thus they should be more polar and have a milder aggregation potential than conventional amyloid regions protected inside globular proteins. CARs are connected with IDPs function and, in particular, with the establishment of protein-protein interactions through their IDRs. However, their presence also appears associated with pathologies like cancer or Alzheimer’s disease. Given the relevance of CARs for both IDPs function and malfunction, we developed CARs-DB, a database containing precomputed predictions for all CARs present in the IDPs deposited in the DisProt database. This web tool allows for the fast and comprehensive exploration of previously unnoticed amyloidogenic regions embedded within IDRs sequences and might turn helpful in identifying disordered interacting regions. It contains >8,900 unique CARs identified in a total of 1711 IDRs. CARs-DB is freely available for users and can be accessed at http://carsdb.ppmclab.com. To validate CARs-DB, we demonstrate that two previously undescribed CARs selected from the database display full amyloidogenic potential. Overall, CARs-DB allows easy access to a previously unexplored amyloid sequence space.

Mechanism of action of hepatitis B virus S antigen transport-inhibiting oligonucleotide polymer, STOPS, molecules

A functional cure of chronic hepatitis B requires eliminating the hepatitis B virus (HBV)-encoded surface antigen (HBsAg), which can suppress immune responses. STOPS are phosphorothioated single-stranded oligonucleotides containing novel chemistries that significantly reduce HBsAgs produced by HBV-infected liver cells. The STOPS molecule ALG-10000 functions inside cells to reduce the levels of multiple HBV-encoded molecules. However, it does not bind HBV molecules. An affinity resin coupled with ALG-10000 was found to bind several proteins from liver cells harboring replicating HBV. Silencing RNAs targeting host factors SRSF1, HNRNPA2B1, GRP78 (HspA5), RPLP1, and RPLP2 reduced HBsAg levels and other HBV molecules that are concomitantly reduced by STOPS. Host proteins RPLP1/RPLP2 and GRP78 function in the translation of membrane proteins, protein folding, and degradation. ALG-10000 and the knockdowns of RPLP1/2 and GRP78 decreased the levels of HBsAg and increased their ubiquitination and proteasome degradation. GRP78, RPLP1, and RPLP2 affected HBsAg production only when HBsAg was expressed with HBV regulatory sequences, suggesting that HBV has evolved to engage with these STOPS-interacting molecules. The STOPS inhibition of HBsAg levels in HBV-infected cells occurs by sequestering cellular proteins needed for proper expression and folding of HBsAg.

RPLP1, an NS4B-interacting protein, enhances production of CSFV through promoting translation of viral genome

Classical swine fever virus (CSFV), the etiological agent of classical swine fever (CSF), causes serious financial losses to the pig industry. Using yeast two-hybrid screening, we have previously identified ribosomal protein RPLP1 as a potential binding partner of CSFV NS4B. In this study, the interaction between host RPLP1 and CSFV NS4B was further characterized by co-immunoprecipitation (co-IP), glutathione S-transferase (GST) pulldown, and confocal microscopy. In addition, lentivirus-mediated shRNA knockdown of RPLP1 drastically attenuated CSFV growth, while stable overexpression of RPLP1 markedly enhanced CSFV production. Moreover, cellular RPLP1 expression was found to be significantly up-regulated along with CSFV infection. Dual-luciferase reporter assay showed that depletion of RPLP1 had no effects on the activity of CSFV internal ribosome entry site (IRES). In the first life cycle of CSFV, further studies revealed that RPLP1 depletion did not influence the intracellular viral RNA abundance but diminished the intracellular and extracellular progeny virus titers as well as the viral E2 protein expression, which indicates that RPLP1 is crucial for CSFV genome translation. In summary, this study demonstrated that RPLP1 interacts with CSFV NS4B and enhances virus production via promoting translation of viral genome.

Minding the message: tactics controlling RNA decay, modification, and translation in virus-infected cells

With their categorical requirement for host ribosomes to translate mRNA, viruses provide a wealth of genetically tractable models to investigate how gene expression is remodeled post-transcriptionally by infection-triggered biological stress. By co-opting and subverting cellular pathways that control mRNA decay, modification, and translation, the global landscape of post-transcriptional processes is swiftly reshaped by virus-encoded factors. Concurrent host cell-intrinsic countermeasures likewise conscript post-transcriptional strategies to mobilize critical innate immune defenses. Here we review strategies and mechanisms that control mRNA decay, modification, and translation in animal virus-infected cells. Besides settling infection outcomes, post-transcriptional gene regulation in virus-infected cells epitomizes fundamental physiological stress responses in health and disease.

Preventing translational inhibition from ribosomal protein insufficiency by a herpes simplex virus-encoded ribosome-associated protein

In addition to being required for protein synthesis, ribosomes and ribosomal proteins (RPs) also regulate messenger RNA translation in uninfected and virus-infected cells. By individually depleting 85 RPs using RNA interference, we found that overall protein synthesis in uninfected primary fibroblasts was more sensitive to RP depletion than those infected with herpes simplex virus-1 (HSV-1). Although representative RP depletion (uL3, uS4, uL5) inhibited protein synthesis in cells infected with two different DNA viruses (human cytomegalovirus, vaccinia virus), HSV-1-infected cell protein synthesis unexpectedly endured and required a single virus-encoded gene product, VP22. During individual RP insufficiency, VP22-expressing HSV-1 replicated better than a VP22-deficient variant. Furthermore, VP22 promotes polysome accumulation in virus-infected cells when uL3 or ribosome availability is limiting and cosediments with initiating and elongating ribosomes in infected and uninfected cells. This identifies VP22 as a virus-encoded, ribosome-associated protein that compensates for RP insufficiency to support viral protein synthesis and replication. Moreover, it reveals an unanticipated class of virus-encoded, ribosome-associated effectors that reduce the dependence of protein synthesis upon host RPs and broadly support translation during physiological stress such as infection.

Identification and Validation of a Novel RNA-Binding Protein-Related Gene-Based Prognostic Model for Multiple Myeloma

Background

Multiple myeloma (MM) is a malignant hematopoietic disease that is usually incurable. RNA-binding proteins (RBPs) are involved in the development of many tumors, but their prognostic significance has not been systematically described in MM. Here, we developed a prognostic signature based on eight RBP-related genes to distinguish MM cohorts with different prognoses.

Method

After screening the differentially expressed RBPs, univariate Cox regression was performed to evaluate the prognostic relevance of each gene using The Cancer Genome Atlas (TCGA)-Multiple Myeloma Research Foundation (MMRF) dataset. Lasso and stepwise Cox regressions were used to establish a risk prediction model through the training set, and they were validated in three Gene Expression Omnibus (GEO) datasets. We developed a signature based on eight RBP-related genes, which could classify MM patients into high- and low-score groups. The predictive ability was evaluated using bioinformatics methods. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and gene set enrichment analyses were performed to identify potentially significant biological processes (BPs) in MM.

Result

The prognostic signature performed well in the TCGA-MMRF dataset. The signature includes eight hub genes: HNRNPC, RPLP2, SNRPB, EXOSC8, RARS2, MRPS31, ZC3H6, and DROSHA. Kaplan-Meier survival curves showed that the prognosis of the risk status showed significant differences. A nomogram was constructed with age; B2M, LDH, and ALB levels; and risk status as prognostic parameters. Receiver operating characteristic (ROC) curve, C-index, calibration analysis, and decision curve analysis (DCA) showed that the risk module and nomogram performed well in 1, 3, 5, and 7-year overall survival (OS). Functional analysis suggested that the spliceosome pathway may be a major pathway by which RBPs are involved in myeloma development. Moreover, our signature can improve on the R-International Staging System (ISS)/ISS scoring system (especially for stage II), which may have guiding significance for the future.

Conclusion

We constructed and verified the 8-RBP signature, which can effectively predict the prognosis of myeloma patients, and suggested that RBPs are promising biomarkers for MM.