Long Non-Coding RNA (lncRNA) Roles in Cell Biology, Neurodevelopment and Neurological Disorders

MIR210HG promotes breast cancer progression by IGF2BP1 mediated m6A modification

BACKGROUND

Breast cancer is the most common cancer in women around the world, and the molecular mechanisms of breast cancer progression and metastasis are still unclear. This study aims to clarify the function and N6,2'-O-dimethyladenosine (m6A) regulation of lncRNA MIR210HG in breast cancer.

RESULTS

High expression of MIR210HG was confirmed in breast cancer. MIR210HG promoted breast cancer progression, which was mediated by its encoded miR-210. MIR210HG was regulated by IGF2BP1 mediated m6A modification. IGF2BP1 was confirmed highly expressed in breast cancer and induced both MIR210HG and miR-210 expression, which contributed to breast cancer progression. In addition, MIR210HG transcript was stabilized by IGF2BP1 and co-factor ELAVL1. IGF2BP1 was a direct target of MYCN via E-box binding motif. MYCN induced IGF2BP1 expression in breast cancer cells. MIR210HG and miR-210 expressions were also increased by MYCN.

CONCLUSIONS

In breast cancer, MIR210HG functions as an oncogenic lncRNA, which is also mediated by its encoded miR-210. In addition, both IGF2BP1 and ELAVL1 enhance the stability of MIR210HG, which contributes to the progression of breast cancer. Interestingly, IGF2BP1 is directly activated by MYCN, which explains the oncogenic role of MYCN. These findings clarify the m6A regulation related molecular mechanism of breast cancer progression. The MYCN/IGF2BP1/MIR210HG axis may serve as an alternative molecular mechanism of breast cancer progression.

Targeting the lncRNA DUXAP8/miR-29a/PIK3CA Network Restores Doxorubicin Chemosensitivity via PI3K-AKT-mTOR Signaling and Synergizes With Inotuzumab Ozogamicin in Chemotherapy-Resistant B-Cell Acute Lymphoblastic Leukemia

Purpose

This study aimed to determine the expression profiles of long non-coding RNA (lncRNA), microRNA (miRNA), and mRNA in chemotherapy-resistant B-cell acute lymphoblastic leukemia (B-ALL).

Methods

LncRNA, miRNA, and mRNA profiles were assessed by RNA-seq in diagnostic bone marrow samples from 6 chemotherapy-resistant and 6 chemotherapy-sensitive B-ALL patients. The lncRNA DUXAP8/miR-29a/PIK3CA signaling network was identified as the most dysregulated in chemoresistant patient samples, and its effect on cellular phenotypes, PI3K-AKT-mTOR signaling, and chemosensitivity of doxorubicin (Dox)-resistant Nalm-6 (N6/ADR), and Dox-resistant 697 (697/ADR) cells were assessed. Furthermore, its synergy with inotuzumab ozogamicin treatment was investigated.

Results

1,338 lncRNAs, 75 miRNAs, and 1620 mRNAs were found to be dysregulated in chemotherapy-resistant B-ALL in comparison to chemotherapy-sensitive B-ALL patient samples. Through bioinformatics analyses and RT-qPCR validation, the lncRNA DUXAP8/miR-29a/PIK3CA network and PI3K-AKT-mTOR signaling were identified as significantly associated with B-ALL chemotherapy resistance. In N6/ADR and 697/ADR cells, LncRNA DUXAP8 overexpression and PIK3CA overexpression induced proliferation and inhibited apoptosis, and their respective knockdowns inhibited proliferation, facilitated apoptosis, and restored Dox chemosensitivity. MiR-29a was shown to affect the lncRNA DUXAP8/PIK3CA network, and luciferase reporter gene assay showed direct binding between lncRNA DUXAP8 and miR-29a, as well as between miR-29a and PIK3CA. Targeting lncRNA DUXAP8/miR-29a/PIK3CA network synergized with inotuzumab ozogamicin's effect on N6/ADR and 697/ADR cells.

Conclusion

Targeting the lncRNA DUXAP8/miR-29a/PIK3CA network not only induced an apoptotic effect on Dox-resistant B-ALL and restored Dox chemosensitivity via PI3K-AKT-mTOR signaling but also showed synergism with inotuzumab ozogamicin treatment.

PTCHD1: Identification and Neurodevelopmental Contributions of an Autism Spectrum Disorder and Intellectual Disability Susceptibility Gene

Over the last one and a half decades, copy number variation and whole-genome sequencing studies have illuminated the considerable genetic heterogeneity that underlies the etiologies of autism spectrum disorder (ASD) and intellectual disability (ID). These investigations support the idea that ASD may result from complex interactions between susceptibility-related genetic variants (single nucleotide variants or copy number variants) and the environment. This review outlines the identification and neurobiological characterization of two such genes located in Xp22.11, Patched domain-containing 1 (PTCHD1), and its antisense lncRNA PTCHD1-AS. Animal models of Ptchd1 disruption have recapitulated a subset of clinical symptoms related to ASD as well as to ID. Furthermore, these Ptchd1 mouse knockout studies implicate the expression of Ptchd1 in both the thalamic and the hippocampal brain regions as being crucial for proper neurodevelopment and cognitive function. Altered kynurenine metabolic signalling has been postulated as a disease mechanism in one of these animal studies. Additionally, ASD patient-derived induced pluripotent stem cells (iPSCs) carrying a copy number loss impacting the antisense non-coding RNA PTCHD1-AS have been used to generate 2D neuronal cultures. While copy number loss of PTCHD1-AS does not affect the transcription of PTCHD1, the neurons exhibit diminished miniature excitatory postsynaptic current frequency, supporting its role in ASD etiology. A more thorough understanding of risk factor genes, such as PTCHD1 and PTCHD1-AS, will help to clarify the intricate genetic and biological mechanisms that underlie ASD and ID, providing a foundation for meaningful therapeutic interventions to enhance the quality of life of individuals who experience these conditions.

Emerging role of competing endogenous RNA and associated noncoding RNAs in thyroid cancer

Cancer of the thyroid is the most common endocrine malignancy. While treatment options are limited for individuals with medullary or anaplastic thyroid cancer, understanding the underlying mechanisms is vital to developing a successful thyroid cancer treatment strategy due to the tumor's multistep carcinogenesis. Non-coding RNAs (ncRNAs) have been associated with thyroid cancer progression in several recent studies; however, the role of regulatory interactions among different types of ncRNAs in thyroid cancer remains unclear. Recently, competing endogenous RNA (ceRNA) has been discovered as a mechanism demonstrating regulatory interactions among non-coding RNAs, including pseudogenes, long non-coding RNAs (lnRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). It has been concluded from the literature that numerous ceRNA networks are deregulated during the development, invasion, and metastasis of thyroid cancer, as well as in epithelial-mesenchymal transition (EMT) and drug resistance. Further understanding of these deregulations is important to develop diagnostic procedures for early detection of thyroid cancer and promising therapeutic options for effective treatment. The purpose of this review is to highlight the emerging roles of some newly found ceRNA members in thyroid cancer and outline the current body of knowledge regarding ceRNA, lncRNA, pseudogenes, and miRNAs.

Identification of multiple TAR DNA binding protein retropseudogene lineages during the evolution of primates

The TAR DNA Binding Protein (TARDBP) gene has become relevant after the discovery of its several pathogenic mutations. The lack of evolutionary history is in contrast to the amount of studies found in the literature. This study investigated the evolutionary dynamics associated with the retrotransposition of the TARDBP gene in primates. We identified novel retropseudogenes that likely originated in the ancestors of anthropoids, catarrhines, and lemuriformes, i.e. the strepsirrhine clade that inhabit Madagascar. We also found species-specific retropseudogenes in the Philippine tarsier, Bolivian squirrel monkey, capuchin monkey and vervet. The identification of a retropseudocopy of the TARDBP gene overlapping a lncRNA that is potentially expressed opens a new avenue to investigate TARDBP gene regulation, especially in the context of TARDBP associated pathologies.

LINC01088 regulates the miR-95/LATS2 pathway through the ceRNA mechanism to inhibit the growth, invasion and migration of gastric cancer cells

Background: In gastric cancer, a malignant condition with a dismal prognosis, long non-coding RNAs (LncRNAs) play a significant regulatory role. They often compete with microRNAs through the ceRNA mechanism to affect the expression of target mRNA. However, the specific clinical value and mechanism of action of LncRNA in gastric cancer are still unclear. Methods: This study detected the expression and clinical value of LINC01088 in gastric cancer tissues. Furthermore, the biological functions of LINC01088 and the regulation mechanism of the miR-95/LATS2 pathway were explored.Results: LINC01088 and LATS2 mRNA expression decreased, and miR-95 increased in gastric cancer tissues. LINC01088 has an excellent positive correlation with LATS2 mRNA, which may be a ceRNA pair; LINC01088 has binding sites with miR-95. Gene interference tests on gastric cancer cell lines revealed that LINC01088 could prevent gastric cancer cells from proliferating, invading, and migrating. The function of LINC01088 is achieved by regulating the miR-95/LATS2 pathway through the ceRNA mechanism.Conclusion: The results of this study show that LINC01088 expression is significantly reduced in gastric cancer tissues and cell lines. LINC01088 inhibits gastric cancer cells’ proliferation, invasion, and migration by regulating the miR-95/LATS2 pathway via the ceRNA mechanism.

17q12 Recurrent Deletions and Duplications: Description of a Case Series with Neuropsychiatric Phenotype

Syndromic neurodevelopmental disorders are usually investigated through genetics technologies, within which array comparative genomic hybridization (Array-CGH) is still considered the first-tier clinical diagnostic test. Among recurrent syndromic imbalances, 17q12 deletions and duplications are characterized by neurodevelopmental disorders associated with visceral developmental disorders, although expressive variability is common. Here we describe a case series of 12 patients with 17q12 chromosomal imbalances, in order to expand the phenotypic characterization of these recurrent syndromes whose diagnosis is often underestimated, especially if only mild traits are present. Gene content and genotype-phenotype correlations have been discussed, with special regard to neuropsychiatric features, whose impact often requires etiologic analysis.