[Aberrant Expression of Small Nucleolar RNA SNORA63 and Its Clinical Significance in Patients with Acute Leukemia].

OBJECTIVE: To investigate the expression level of small nucleolar RNA (snoRNA) SNORA63 in bone marrow of patients with acute leukemia (AL) and its significance in the clinical diagnosis, treatment and prognosis of AL patients. METHODS: Bone marrow samples of 53 newly diagnosed AL patients and 29 healthy subjects in the Affiliated Hospital of Guangdong Medical University from March 2018 to December 2021 were collected. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the relative expression level of SNORA63 in bone marrow mononuclear cells of the two groups. The median expression level of SNORA63 in AL patients was used as the boundary value to divide the patients into SNORA63 high and low expression groups, and the relationship between the expression level of SNORA63 and the clinical characteristics, clinical indicators and prognosis of AL patients was analyzed and discussed. RESULTS: The relative expression level of SNORA63 in AL patients was significantly lower than that in healthy control group [0.3018 (0.0244-1.2792) vs 1.0882 (0.2797-1.9889)] (P < 0.01). The expression level of SNORA63 in AL patients without remission after initial treatment was significantly lower than that in healthy controls and the patients who received complete remission (CR) (P < 0.01), while there was no statistical difference in the expression level of SNORA63 between AML and ALL groups (P >0.05). The abnormal low expression of SNORA63 was closely related to fever, hemorrage, poor prognosis, efficacy, platelets (PLT), lactate dehydrogenase (LDH), albumin (ALB), and molecular biological abnormalities of AL patients (P < 0.05), but not significantly correlated with sex, age, AL subtype, pallor, fatigue, extramedullary infiltration, white blood cell count (WBC), hemoglobin (HGB), C-reactive protein (CRP), procalcitonin (PCT), fibrinogen (FIB) or chromosome karyotype (P >0.05). Meanwhile, overall survival (OS) and event-free survival (EFS) of AL patients in SNORA63 high-expression group were significantly higher than those in SNORA63 low-expression group (P < 0.05). Univariate Cox regression analysis showed that SNORA63, molecular biological abnormalities, fever, PLT and LDH were the factors influencing OS and EFS in AL patients (P < 0.05). Multivariate Cox regression analysis indicated that fever, molecular biological abnormalities and LDH were independent factors associated with OS and EFS in AL patients (P < 0.05). CONCLUSION: SNORA63 is significantly down-expressed in AL patients, which is a molecular marker of great clinical value for disease monitoring and prognosis evaluation in AL patients.

Quantitative Virus-Associated RNA Detection to Monitor Oncolytic Adenovirus Replication.

Oncolytic adenoviruses are in development as immunotherapeutic agents for solid tumors. Their efficacy is in part dependent on their ability to replicate in tumors. It is, however, difficult to obtain evidence for intratumoral oncolytic adenovirus replication if direct access to the tumor is not possible. Detection of systemic adenovirus DNA, which is sometimes used as a proxy, has limited value because it does not distinguish between the product of intratumoral replication and injected virus that did not replicate. Therefore, we investigated if detection of virus-associated RNA (VA RNA) by RT-qPCR on liquid biopsies could be used as an alternative. We found that VA RNA is expressed in adenovirus-infected cells in a replication-dependent manner and is secreted by these cells in association with extracellular vesicles. This allowed VA RNA detection in the peripheral blood of a preclinical in vivo model carrying adenovirus-injected human tumors and on liquid biopsies from a human clinical trial. Our results confirm that VA RNA detection in liquid biopsies can be used for minimally invasive assessment of oncolytic adenovirus replication in solid tumors in vivo.

Relaxed Cleavage Specificity of Hyperactive Variants of Escherichia coli RNase E on RNA I.

RNase E is an essential enzyme in Escherichia coli. The cleavage site of this single-stranded specific endoribonuclease is well-characterized in many RNA substrates. Here, we report that the upregulation of RNase E cleavage activity by a mutation that affects either RNA binding (Q36R) or enzyme multimerization (E429G) was accompanied by relaxed cleavage specificity. Both mutations led to enhanced RNase E cleavage in RNA I, an antisense RNA of ColE1-type plasmid replication, at a major site and other cryptic sites. Expression of a truncated RNA I with a major RNase E cleavage site deletion at the 5'-end (RNA I-5) resulted in an approximately twofold increase in the steady-state levels of RNA I-5 and the copy number of ColE1-type plasmid in E. coli cells expressing wild-type or variant RNase E compared to those expressing RNA I. These results indicate that RNA I-5 does not efficiently function as an antisense RNA despite having a triphosphate group at the 5'-end, which protects the RNA from ribonuclease attack. Our study suggests that increased cleavage rates of RNase E lead to relaxed cleavage specificity on RNA I and the inability of the cleavage product of RNA I as an antisense regulator in vivo does not stem from its instability by having 5'-monophosphorylated end.

A novel concept of human antiviral protection: It's all about RNA (Review).

The comparative analysis of the antiviral protective mechanisms, including protozoa and RNA interference in multicellular organisms, has revealed their similarity and provided a basic understanding of adaptive immunity. The present article summarizes the latest studies on RNA-guided gene regulation in human antiviral protection, and its importance. Additionally, the role of both neutralizing antibodies and the interferon system in viral invasion is considered. The interferon system is an additional mechanism for suppressing viral infections in humans, which shifts cells into an 'alarm' mode to attempt to prevent further contagion. The primary task of the human central immune system is to maintain integrity and to protect against foreign organisms. In this review, a novel concept is proposed: Antiviral protection in all organisms can be achieved through an intracellular RNA-guided mechanism. A simple and effective defence against viruses is incorporation of a part of a virus's DNA (spacer) into the hosts chromosomes. Following reinfection, RNA transcripts of this spacer are created to direct nuclease enzymes to destroy the viral genome. This is an example of real-time adaptive immunity potentially possessed by every cell with a full complement of chromosomes, and an indicator that antiviral immunity is not only mediated by the presence of neutralizing antibodies and memory B- and T-cells, but also by the presence of specific spacers in the DNA of individuals who have recovered from a viral infection.

Identifying i-motif formation using capillary electrophoresis.

Over the past few years, intercalated motifs (i-motifs) have attracted attention due to the direct visualization of their existence in the nuclei of human cells. Traditionally, i-motifs have been studied using expensive and complicated NMR, and/or relatively inexpensive but less common circular dichroism spectrometry. The aim of this study was to investigate the feasibility of using less expensive, less complicated, and more widely available CE as an alternative for i-motif related research. The mobilities of two DNA and RNA i-motifs in CE were determined under different pH conditions. Our results demonstrate that CE is able to identify and differentiate mostly folded, partially folded, and mostly unfolded DNA and RNA i-motifs through changes in peak shape and migration time, thus providing a new method to study both i-motif conformation and the interactions between i-motifs and their ligands.

Long non-coding RNA Mirt2 interacts with long non-coding RNA IFNG-AS1 to regulate ulcerative colitis.

Long non-coding RNAs (lncRNAs) Mirt2 and interferon-γ antisense RNA I (IFNG-AS1) play opposing roles in lipopolysaccharide (LPS)-induced inflammation, a key initiator of ulcerative colitis (UC). The present study aimed to analyze the potential interaction between Mirt2 and IFNG-AS1 in UC. Levels of IFNG-AS1 and Mirt2 in plasma samples from UC patients were measured using reverse transcription-quantitative PCR. Receiver operating characteristic curves were used to evaluate the diagnostic values of IFNG-AS1 and Mirt2 fr UC. The role of Mirt2 and IFNG-AS1 in colonic epithelial cell apoptosis was analyzed by cell apoptosis assay. In patients with UC, Mirt2 and IFNG-AS1 exhibited an inverse correlation, in which Mirt2 was downregulated while IFNG-AS1 was upregulated. Altered expression of IFNG-AS1 and Mirt2 separated patients with UC from healthy controls. In colonic epithelial cells, lipopolysaccharide treatment led to the downregulation of Mirt2 and the upregulation of IFNG-AS1. Furthermore, overexpression of Mirt2 in colonic epithelial cells resulted in downregulation of IFNG-AS1, and vice versa. Overexpression of Mirt2 led to a decreased rate of colonic epithelial cell apoptosis, while overexpression of IFNG-AS1 led to an increased rate of apoptosis. Moreover, IFNG-AS1 overexpression attenuated the effects of Mirt2 overexpression. Therefore, Mirt2 may interact with IFNG-AS1 during UC to participate in colonic epithelial cell apoptosis.

[Research Progress on Estimation of Postmortem Interval Using mRNA and ncRNA].

ABSTRACT: Postmortem interval （PMI） estimation has always been an important and difficult issue in the field of forensic pathology. In recent years, research progress on the estimation of PMI using RNA specific variation patterns after death has been made by researchers at home and aboard. This paper summarizes the specific application methods of messenger RNA and non-coding RNA for PMI estimation based on the literatures and discusses the existing problems and development trends, in order to provide technical reference for related studies and estimation practice.

NAD in RNA: unconventional headgear.

Although widely assumed to bear a 5'-terminal triphosphate or monophosphate, recent evidence suggests that the 5' end of bacterial RNA can sometimes bear a modification reminiscent of a eukaryotic cap. A new study has now identified Escherichia coli RNAs that begin with a noncanonical cap resembling the redox cofactor nicotinamide adenine dinucleotide (NAD), as well as a cellular enzyme that can remove it. The biological function of such caps remains to be determined.