Deregulated lncRNA expression profile in the mouse lung adenocarcinomas with KRAS-G12D mutation and P53 knockout

Establishment and Phenotypic Analysis of the Novel Gaucher Disease Mouse Model With the Partially Humanized Gba1 Gene and F213I Mutation

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the GBA1 gene, which produces the glucocerebrosidase (GCase) protein. There are more than 500 mutations reported in GBA1, among which L444P (p.Leu444Pro) and F213I (p.Phe213Ile) are the most common in the Chinese population, while the function of F213I mutation remains elusive. This study aims to establish the GD mouse model of partially humanized Gba1 gene with F213I mutation. In vitro GCase activity assays showed that the product of partially humanized Gba1 gene, in which the mouse exons 5-7 were replace by the corresponding human exons, displayed similar activity with the wild-type mouse Gba1, while the F213I mutation in the humanized Gba1 led to significant decrease in enzyme activity. ES cell targeting was used to establish the mice expressing the partially humanized Gba1-F213I. Gba1^F213I/+ mice did not show obviously abnormal phenotypes, but homozygous Gba1^F213I/F213I mice died within 24 h after birth, whose epidermal stratum corneum were abnormal from the wild-type. The GCase activity in Gba1^F213I/F213I mice greatly decreased. In conclusion, our results showed that the partially humanized GD mouse model with the F213I mutation was developed and homozygous F213I mutation is lethal for newborn mice.

Revisiting Lung Cancer Metastasis: Insight From the Functions of Long Non-coding RNAs

Globally, lung cancer is the most common cause of cancer-related deaths. After diagnosis at all stages, <7% of patients survive for 10 years. Thus, diagnosis at later stages and the lack of effective and personalized drugs reflect a significant need to better understand the mechanisms underpinning lung cancer progression. Metastasis should be responsible for the high lethality and recurrence rates seen in lung cancer. Metastasis depends on multiple crucial steps, including epithelial–mesenchymal transition, vascular remodeling, and colonization. Therefore, in-depth investigations of metastatic molecular mechanisms can provide valuable insights for lung cancer treatment. Recently, long noncoding RNAs (lncRNAs) have attracted considerable attention owing to their complex roles in cancer progression. In lung cancer, multiple lncRNAs have been reported to regulate metastasis. In this review, we highlight the major molecular mechanisms underlying lncRNA-mediated regulation of lung cancer metastasis, including (1) lncRNAs acting as competing endogenous RNAs, (2) lncRNAs regulating the transduction of several signal pathways, and (3) lncRNA coordination with enhancer of zeste homolog 2. Thus, lncRNAs appear to execute their functions on lung cancer metastasis by regulating angiogenesis, autophagy, aerobic glycolysis, and immune escape. However, more comprehensive studies are required to characterize these lncRNA regulatory networks in lung cancer metastasis, which can provide promising and innovative novel therapeutic strategies to combat this disease.

Ablation of Zfhx4 results in early postnatal lethality by disrupting the respiratory center in mice

Breathing is an integrated motor behavior that is driven and controlled by a network of brainstem neurons. Zfhx4 is a zinc finger transcription factor and our results showed that it was specifically expressed in several regions of the mouse brainstem. Mice lacking Zfhx4 died shortly after birth from an apparent inability to initiate respiration. We also found that the electrical rhythm of brainstem‒spinal cord preparations was significantly depressed in Zfhx4-null mice compared to wild-type mice. Immunofluorescence staining revealed that Zfhx4 was coexpressed with Phox2b and Math1 in the brainstem and that Zfhx4 ablation greatly decreased the expression of these proteins, especially in the retrotrapezoid nucleus. Combined ChIP‒seq and mRNA expression microarray analysis identified Phox2b as the direct downstream target gene of Zfhx4, and this finding was validated by ChIP‒qPCR. Previous studies have reported that both Phox2b and Math1 play key roles in the development of the respiratory center, and Phox2b and Math1 knockout mice are neonatal lethal due to severe central apnea. On top of this, our study revealed that Zfhx4 is a critical regulator of Phox2b expression and essential for perinatal breathing.

AMOTL2 inhibits JUN Thr239 dephosphorylation by binding PPP2R2A to suppress the proliferation in non-small cell lung cancer cells

Protein phosphatase 2A (PP2A) complex comprises an extended family of intracellular protein serine/threonine phosphatases, that participate in different signaling transduction pathways. Different functions of PP2As are determined by the variety of regulatory subunits. In this study, CRISPR/Cas9-mediated loss-of-function screen revealed that PPP2R2A downregulation suppressed cell growth in NSCLC cells. AMOTL2 was identified and confirmed as a novel binding partner of PPP2R2A in NSCLC cells by mass spectrometry, CO-IP, GST pull-down and immunofluorescence. Upregulation of AMOTL2 also led to cell proliferation delay in human and mouse lung tumor cells. The proto-oncogene JUN is a key subunit of activator protein-1 (AP-1) transcription factor which plays crucial role in regulating tumorigenesis and its activity is negatively regulated by the phosphorylation at T239. Our results showed that either AMOTL2 upregulation or PPP2R2A downregulation led to great increase in JUN T239 phosphorylation. AMOTL2 bound PPP2R2A in cytoplasm, which reduced nuclear localization of PPP2R2A. In conclusion, AMOTL2 and PPP2R2A act respectively as negative and positive regulator of cell growth in NSCLC cells and function in the AMOTL2-PPP2R2A-JUN axis, in which AMOTL2 inhibits the entry of PPP2R2A into the nucleus to dephosphorylate JUN at T239.

LncRNA-mRNA expression profiles and functional networks in osteoclast differentiation

Human osteoclasts are differentiated from CD14⁺ monocytes and are responsible for bone resorption. Long non‐coding RNAs (lncRNAs) have been proved to be significantly involved in multiple biologic processes, especially in cell differentiation. However, the effect of lncRNAs in osteoclast differentiation is less appreciated. In our study, RNA sequencing (RNA‐seq) was used to identify the expression profiles of lncRNAs and mRNAs in osteoclast differentiation. The results demonstrated that expressions of 1117 lncRNAs and 296 mRNAs were significantly altered after osteoclast differentiation. qRT‐PCR assays were performed to confirm the expression profiles, and the results were almost consistent with the RNA‐seq data. GO and KEGG analyses were used to predict the functions of these differentially expressed mRNA and lncRNAs. The Path‐net analysis demonstrated that MAPK pathway, PI3K‐AKT pathway and NF‐kappa B pathway played important roles in osteoclast differentiation. Co‐expression networks and competing endogenous RNA networks indicated that ENSG00000257764.2‐miR‐106a‐5p‐TIMP2 may play a central role in osteoclast differentiation. Our study provides a foundation to further understand the role and underlying mechanism of lncRNAs in osteoclast differentiation, in which many of them could be potential targets for bone metabolic disease.

Deregulated lncRNA expression profile in the mouse lung adenocarcinomas with KRAS-G12D mutation and P53 knockout

Recent studies have demonstrated that aberrant long non‐coding RNAs (lncRNAs) expression are suggested to be closely associated with multiple human diseases, lung cancer included. However, the roles of lncRNAs in lung cancer are not well understood. In this study, we used microarrays to investigate the aberrantly expressed lncRNAs in the mouse lung adenocarcinoma with P53 knockout and the Kras^G12D mutation. Results revealed that 6424 lncRNAs were differentially expressed (≥ 2‐fold change, P < .05). Two hundred and ten lncRNAs showed more than 8‐fold change and conserved across human and were further analysed in the primary mouse lung adenocarcinoma KP cells, which were isolated from the p53 knockout and the Kras^G12D mutation mice. Among all the 210 lncRNAs, 11 lncRNAs' expression was regulated by P53, 33 lncRNAs by KRAS and 13 lncRNAs by hypoxia in the primary KP cells, respectively. NONMMUT015812, which was remarkably up‐regulated in the mouse lung adenocarcinoma and negatively regulated by the P53 re‐expression, was detected to analyse its cellular function. Results showed that knockdown of NONMMUT015812 by shRNAs decreased proliferation and migration abilities of KP cells. Among those aberrantly expressed lncRNAs in the mouse lung adenocarcinoma, NONMMUT015812 was a potential oncogene.