SnoRNA and lncSNHG: Advances of nucleolar small RNA host gene transcripts in anti-tumor immunity

Abstract

The small nucleolar RNA host genes (SNHGs) are a group of genes that can be transcript into long non-coding RNA SNHG (lncSNHG) and further processed into small nucleolar RNAs (snoRNAs). Although lncSNHGs and snoRNAs are well established to play pivotal roles in tumorigenesis, how lncSNHGs and snoRNAs regulate the immune cell behavior and function to mediate anti-tumor immunity remains further illustrated. Certain immune cell types carry out distinct roles to participate in each step of tumorigenesis. It is particularly important to understand how lncSNHGs and snoRNAs regulate the immune cell function to manipulate anti-tumor immunity. Here, we discuss the expression, mechanism of action, and potential clinical relevance of lncSNHGs and snoRNAs in regulating different types of immune cells that are closely related to anti-tumor immunity. By uncovering the changes and roles of lncSNHGs and snoRNAs in different immune cells, we aim to provide a better understanding of how the transcripts of SNHGs participate in tumorigenesis from an immune perspective.

Subverting the Canon: Novel Cancer-Promoting Functions and Mechanisms for snoRNAs

“…In addition to these canonical functions in the nucleolus, snoRNAs are involved in non-canonical mechanisms, such as the biogenesis of piwi-interacting RNA (piRNA) and snoRNA-derived fragments (sdRNA), the derivation of certain microRNAs (miRNAs), tRNA methylation, and rRNA acetylation [ 9 ]. Moreover, snoRNAs turned out to play diverse roles in RNA-related processes, regulating splicing and chromatin accessibility [ 9 ]. All of these epigenetic processes play a crucial role in the proper execution of cellular bioactivities.…”

“…SNHGs, which can be protein-coding or noncoding genes, produce primary transcripts in the nucleus. These transcripts undergo splicing, with exons directed to cytoplasmic functions as either protein-coding mRNAs or noncoding RNAs (long noncoding RNA SNHGs; lncSNHGs) ( Figure 1 (3b): Spliced lncSNHG/mRNA) [ 9 , 18 , 19 ]. Introns yield mature snoRNAs, which then localize to the nucleolus and Cajal bodies ( Figure 1 (3a): Post-transcription processing) [ 20 , 21 , 22 , 23 ].…”

Characterization the prognosis role and effects of snoRNAs in melanoma patients

“…For instance, Zhang et al have found that a long non-coding RNA (lncRNA), which named PRRT3-AS1, could be treated as a potential biomarker for melanoma treatment. 4 Another study discovered P4HA1 as a biomarker associated with poor prognosis in primary melanomas. 5 However, the clinical application of therapeutic targets and biomarkers in melanoma is still limited due to its complex and immune-related heterogeneity.…”

“…As several studies have mentioned, the potential of biomarkers in the identification and prognosis of melanoma is highlighted. For instance, Zhang et al have found that a long non‐coding RNA (lncRNA), which named PRRT3‐AS1, could be treated as a potential biomarker for melanoma treatment 4 . Another study discovered P4HA1 as a biomarker associated with poor prognosis in primary melanomas 5 .…”

“…Half a century ago, researchers discovered a class of noncoding RNA known as snoRNAs, which are widely present in the nucleoli of eukaryotic cells and can bind to nucleolar riboproteins to carry out unique biological functions. 4,5 Many studies have demonstrated that snoRNAs primarily participate in rRNA modification or regulate the mRNA splicing and translation. 6,7 Meanwhile, the significant role of snoRNAs in biological regulation, particularly in tumour regulation, was also illustrated in many researches.…”