OBJECTIVE: Recent studies have indicated that HOTTIP and MEG3 are associated with the initiation and progression of various types of tumors, including nasopharyngeal carcinoma (NPC). This investigation aimed to elucidate the impact of HOTTIP and MEG3 polymorphisms on the susceptibility and clinicopathologic characteristics of NPC.
METHODS: This research employed next-generation sequencing and multiplex PCR to assess the polymorphisms of HOTTIP rs1859168 and MEG3 rs7158663 in 200 NPC and 200 healthy individuals respectively. HOTTIP and MEG3 expression were assessed via qRT-PCR assessment. Furthermore, the genotypes and alleles frequency of rs1859168 and rs7158663 were compared between healthy and NPC individuals to elucidate their influence on NPC susceptibility and relation with clinicopathologic characteristics.
RESULTS: In comparison with the healthy cohort, the presence of HOTTIP rs1859168 CC genotype and the C allele were markedly linked with increased NPC incidence (p < 0.05). Furthermore, the MEG3 rs7158663 AA genotype and the A allele also indicated an increased risk of NPC (p < 0.05). The subgroup analysis of age, EBV infection, gender, nationality, smoking, and drinking status revealed no marked association between rs1859168 and rs7158663 genotypes and these potential confounding factors. Moreover, it was observed that rs1859168 CC and rs7158663 AA genotypes were related to local tumor invasion and lymph node metastasis. Additionally, HOTTIP indicated a marked elevation, while MEG3 substantially reduced in NPC samples than the normal nasopharyngeal biospecimens. Patients who carried CC or CA genotypes rather than the HOTTIP rs1859168 AA genotype, had substantially higher HOTTIP levels, while patients with rs7158663 AA or GA genotypes indicated notably lower expression of MEG3 than GG genotype carriers.
CONCLUSIONS: Individuals with genetic variants of HOTTIP rs1859168 and MEG3 rs7158663 might have an increased risk of NPC susceptibility and related clinicopathologic characteristics, potentially by affecting the expression of HOTTIP and MEG3.

HOXA transcript at the distal tip (HOTTIP), a lncRNA, induces cell proliferation and cancer progression. However, the expression and function of HOTTIP in renal cell carcinoma (RCC) were rarely reported. The role of the HOTTIP in RCC was explored in this study. HOTTIP expresses higher in RCC tissues than in normal tissues and indicates poor prognosis based on the TCGA database. The over- and low-expression HOTTIP cell line was established in this research to assess the oncogenic function of HOTTIP in RCC progression. Mechanistic analyses revealed that HOTTIP functioned as a competing endogenous RNA (ceRNA) for miR-506. RIP experiment and luciferase assay were performed to explore the mechanisms of the sponge between HOTTIP and miR-506. HOTTIP down-regulation attenuated cell proliferation, migration, and invasion, which could be rescued by miR-506 down-regulation. On the whole, this study revealed that the HOTTIP/miR-506 axis has a dominant impact on RCC progression and potentially provides a novel strategy for RCC diagnosis and therapy.

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients\' blood.

The objective of this study was to elucidate the involvement of the long noncoding RNA (lncRNA) HOTTIP in acute lung injury and understand the underlying mechanisms. Relevant expression of mRNAs and proteins were assessed by qRT-PCR and western blot assays. Cell viability was determined by employing the CCK-8 assay, and apoptosis was quantified through TUNEL staining. The concentration of inflammatory factors was measured by ELISA. The degree of DNA methylation was quantified through MSP assay. The interaction between HOTTIP and DNA methyltransferase 1 (DNMT1) was examined by RIP assay. LPS upregulated HOTTIP, whereas downregulated SP-C level in AEC II cells. HOTTIP knockdown inhibited LPS-induced apoptosis and the secretion of inflammatory cytokines (TNF-α, IL-1β and IL-6) in AEC II cells. Mechanistically, HOTTIP recruited DNMT1 to the SP-C promoter, thereby facilitating DNA methylation of SP-C and suppressing its expression. Additionally, inhibitory of SP-C reversed the effects of HOTTIP or DNMT1 knockdown on apoptosis and inflammation in AEC II cells induced by LPS. HOTTIP recruited DNMT1 to epigenetically inhibit SP-C expression, leading to the promotion of lung epithelial cell injury caused by LPS, suggesting that targeting HOTTIP may be an effective strategy for the therapy of lung epithelial cell injury.

Epigenetic changes, particularly histone compaction modifications, have emerged as critical regulators in the epigenetic pathway driving endothelial cell phenotype under constant exposure to laminar forces induced by blood flow. However, the underlying epigenetic mechanisms governing endothelial cell behavior in this context remain poorly understood. To address this knowledge gap, we conducted in vitro experiments using human umbilical vein endothelial cells subjected to various tensional forces simulating pathophysiological blood flow shear stress conditions, ranging from normotensive to hypertensive forces. Our study uncovers a noteworthy observation wherein endothelial cells exposed to high shear stress demonstrate a decrease in the epigenetic marks H3K4ac and H3K27ac, accompanied by significant alterations in the levels of HDAC (histone deacetylase) proteins. Moreover, we demonstrate a negative regulatory effect of increased shear stress on HOXA13 gene expression and a concomitant increase in the expression of the long noncoding RNA, HOTTIP, suggesting a direct association with the suppression of HOXA13. Collectively, these findings represent the first evidence of the role of histone-related epigenetic modifications in modulating chromatin compaction during mechanosignaling of endothelial cells in response to elevated shear stress forces. Additionally, our results highlight the importance of understanding the physiological role of HOXA13 in vascular biology and hypertensive patients, emphasizing the potential for developing small molecules to modulate its activity. These findings warrant further preclinical investigations and open new avenues for therapeutic interventions targeting epigenetic mechanisms in hypertensive conditions.

BACKGROUND: The present research aims to investigate the clinical diagnostic value of LncRNA HOXA distal transcript antisense RNA (HOTTIP) in acute respiratory distress syndrome (ARDS) of sepsis and its predictive significance for mortality.
METHODS: One hundred eighteenth patients with sepsis and 96 healthy individuals were enrolled. RT-qPCR to examine HOTTIP levels. The incidence of ARDS and death was recorded. The diagnostic significance of HOTTIP in sepsis ARDS was examined using ROC and logistic regression analysis. The correlation between HOTTIP and disease severity was evaluated using Pearson\'s coefficients. Kaplan-Meier analysis and COX regression were employed to examine the predictive significance of mortality. Validation of HOTTIP target miRNA by dual-luciferase assay.
RESULTS: HOTTIP was persistently up-regulated in patients with ARDS sepsis than in patients without ARDS patients (P < 0.05). HOTTIP was a risk factor for the development of ARDS, which could be diagnosed in ARDS patients from non-ARDS patients (AUC = 0.847). Both the SOFA score (r = 0.6793) and the APACHE II score (r = 0.6384) were positively correlated with the HOTTIP levels. Furthermore, serum HOTTIP was an independent predictor of short-term mortality (HR = 4.813. 95%CI: 1.471-15.750, P = 0.009) and noticeably predicted the occurrence of short-term death (log rank = 0.020). miR-574-5p, a target miRNA for HOTTIP, was reduced in patients with sepsis ARDS and negatively correlated with HOTTIP.
CONCLUSIONS: The presence of HOTTIP serves as a diagnostic biomarker for the occurrence of ARDS, exhibits correlation with disease severity, and provides predictive value of short-term mortality in sepsis patients. HOTTIP may be involved in ARDS progression by targeting miR-574-5p.

The clustered homeobox gene family known as the Hox family plays a fundamental role in the morphogenesis of the vertebrate\'s embryo. A long noncoding RNA (lncRNA), known as HOTTIP (HOXA transcript at the distal tip), has been functionally characterized and contributed to the pathogenesis of various conditions. The current case-control study was undertaken to examine the gene frequencies and shared alleles of the HOTTIP  gene in Iranian participants with or without idiopathic recurrent spontaneous abortion (RSA). Both ARMS-PCR reaction and RFLP-PCR techniques were employed to detect three HOTTIP polymorphisms (rs2023843C/T, rs78248039A/T, and rs1859168C/A) in a DNA sample of 161 women with RSA and 177 healthy women. We found that the TT genotype of the HOTTIP rs2023843 C/T polymorphism was associated with a lower risk for idiopathic RSA. In contrast, the TT genotype of the HOTTIP rs78248039 A/T polymorphism was correlated with an enhanced risk of RSA. The presence of the A-allele for HOTTIP rs1859168 C/A polymorphism was associated with an increased risk for idiopathic RSA. Haplotype analysis showed that the T/T/A, C/T/A, T/T/C, and T/A/A haplotypes of rs2023843/rs78248039/rs1859168 enhanced RSA susceptibility. Computational analysis predicted that this lncRNA might act as a potential sponge for some microRNAs; therefore, affecting the expression of genes being targeted by them. In addition, both rs2023843 and rs1859168 variants could alter the local secondary structure of HOTTIP. Our results showed that HOTTIP rs2023843C/T, rs78248039A/T, and rs1859168C/A polymorphisms may confer genetic susceptibility to idiopathic RSA in an Iranian population.

In this study, knockout of FOXO3 was found to impair intervertebral disc maturation and homeostasis in postnatal mice as well as facilitating extracellular matrix degradation. RNA sequencing can uncover disease-related gene expression and investigate disease pathophysiology. High-throughput transcriptome sequencing and experimental validations were used to identify the essential gene and mechanism involved in intervertebral disc degeneration (IDD). Nucleus pulposus (NP) tissue samples were collected from the mice with conditional knockout of FOXO3 (FOXO3 KO) for high-throughput sequencing, followed by screening of differentially expressed lncRNAs and mRNAs. The mRNAs were subjected to GO and KEGG enrichment analyses. Interactions among FOXO3, HOTTIP, miR-615-3p, and COL2A1 were analyzed. NP cells were subjected to a series of mimics, inhibitors, overexpression plasmids, and shRNAs to validate the mechanisms of FOXO3 in controlling HOTTIP/miR-615-3p/COL2A1 in IDD. Mechanistically, FOXO3 transcriptionally activated HOTTIP, facilitated the competitive HOTTIP binding to miR-615-3p, and increased the expression of the miR-615-3p target gene COL2A1. Thus, NP cell proliferation was induced, cell apoptosis was diminished, resulting in delayed development of IDD. Based on these data, the transcription factor FOXO3 may decrease miR-615-3p binding to COL2A1 and up-regulate COL2A1 expression by activating HOTTIP transcription, which in turn inhibits NP cell apoptosis and promotes its proliferation, to prevent the degradation of intervertebral disc matrix and maintain the normal physiological function of intervertebral disc, thereby preventing the occurrence and development of IDD.

Brain Long non-coding RNA (lncRNA) and microRNAs (miRs) play essential roles in the regulation of several important biological processes, including neuronal activity, cognitive processes, neurogenesis, angiogenesis, and neuroinflammation. In this context, the transcriptional repressor, RE1 silencing transcription factor (Rest), acts regulating the expression of neuronal genes as well as of lncRNAs and multiple miRNAs in the central nervous system. Nevertheless, its role in neuroinflammation was less explored. Here, we demonstrate, using an in vivo model of neuroinflammation induced by i.p. injection of LPS (0.33 mg/kg), that neuroinflammation increases gene expression of pro-inflammatory cytokines concomitant with the native and truncated forms of Rest and of non-coding RNAs. Additionally, the increased expression of enzymes Drosha ribonuclease III) (Drosha), Exportin 5 (Xpo5) and Endoribonuclease dicer (Dicer), associated with high expression of neuroprotective miRs 22 and 132 are indicative that the activation of biogenesis of miRs in the hippocampal region is a Central Nervous System (CNS) protective mechanism for the deleterious effects of neuroinflammation. Our results indicate that positive regulation of Rest gene expression in the hippocampal region by neuroinflammation correlates directly with the expression of miRs 22 and 132 and inversely with miR 335. In parallel, the confirmation of the possible alignment between the lncRNAs with miR 335 by bioinformatics corroborates with the sponge effect of Hottip and Hotair hybridizing and inhibiting the pro-inflammatory action of miR 335. This suggests the existence of a possible correlation between the activation of miR biogenesis machinery with increased expression of the transcription factor Rest, contributing to neuroprotection.

BACKGROUND: The long non-coding RNA HOXA transcript at the distal tip (HOTTIP) and homeobox A13 (HOXA13) have been identified as oncogenes that play a pivotal role in tumorigenesis. However, their specific mechanisms of action in nasopharyngeal carcinoma (NPC) progression remain unclear.
RESULTS: In the present study, RT-qPCR was employed to quantify RNA expression in NPC cells and tissues. Flow cytometry, MTT, CCK8 and colony formation assays were utilized to assess cell apoptosis and proliferation. Transwell assay was conducted to evaluate migration and invasion while Western blotting was performed for protein expression analysis. Our findings revealed that the expression of HOTTIP was significantly upregulated in NPC cell lines. Inhibition of HOTTIP could induce apoptosis and suppress proliferation, clonogenicity, invasion and metastasis in NPC cells. Knockdown of HOTTIP led to downregulation of HOXA13 expression, which subsequently inhibited the proliferation and metastasis in NPC cells. The inhibitory effects on cell proliferation and metastasis caused by HOTTIP silencing were rescued by HOXA13 overexpression. Additionally, there was a significant positive correlation between HOTTIP and HOXA13, which were found to be elevated in NPC tissues compared to normal tissues.
CONCLUSIONS: We have determined that LncRNA HOTTIP facilitates tumorigenesis by modulating the expression of HOXA13 in NPC cells. Targeting HOTTIP/HOXA13 may be a promising therapeutic strategy for NPC.