Proliferation is a critical characteristic of the progression of gastric cancer (GC). Receptor tyrosine kinase-like orphan receptor 2 (ROR2), the orphan receptor tyrosine kinase-like receptor, exhibits effects on tumor growth due to its abnormal expression in cancer. The goal of our study was to assess the potential regulatory role exerted by the ROR2 on GC cells. Through previous bioinformatics analysis, we discovered an association between ROR2 and the G2/M phase of the GC cell cycle. However, little is known about the link between ROR2 and the G2/M phase cell cycle in GC. Here, the findings of our study indicate that ROR2, after transcribed expression by Twist1, activates the PI3K/AKT/mTOR/S6K signal transduction pathway, thus leading to the acceleration of the G2/M phase and subsequent promotion of cell proliferation in GC. Furthermore, the functional link among ROR2, Twist1, and G2/M phase of cell cycle was also confirmed in mouse xenograft tissues and human tissues. ROR2 expression was correlated with Twist expression and lower survival in vivo. Notably, our suggestion is that focusing on ROR2 as a potential therapeutic approach could show potential for the management of GC.

Impaired extravillous trophoblast (EVT) invasion and resulted poor placentation play a vital role in the development of preeclampsia (PE). However, the underlying mechanisms of dysregulated EVTs remain unclear. This study aimed to explore the role of poly (C)-binding protein 2 (PCBP2), a multifunctional RNA binding protein, in the pathogenesis of PE and to investigate the detailed signaling pathway. Using qRT-PCR, western blot, and immunohistochemistry, we confirmed that the expression of PCBP2 significantly decreased in placentas from 18 early-onset PE and 30 late-onset PE in comparison to those from 30 normotensive pregnancies. Besides, more significant suppression of PCBP2 was observed in the early-onset type. After transfection of HTR-8/SVneo with small interfering RNA (siRNA) specific to PCBP2, the cellular biological behaviors including vitality, immigration, invasiveness, and apoptosis were evaluated by CCK-8 assay, wound-healing assay, transwell assay, and flow cytometry respectively. RNA-seq was applied to screen differentially expressed genes (DEGs) in HTR-8/SVneo upon PCBP2 silencing. GO and KEGG analysis indicated that WNT signaling pathway and the related processes such as extracellular matrix remodeling and cell adhesion were among the most enriched pathways or processes. Meanwhile, the alternative splicing of WNT5A regulated by PCBP2 was also identified by RIP-seq. Based on HTR-8/SVneo and villous explant, the regulatory roles of PCBP2 on trophoblast were confirmed to be mediated by WNT5A. Besides, it revealed that ROR2/JNK/MMP2/9 pathway was a vital pathway downstream WNT5A in trophoblast cells. In conclusion, this study suggests that down-regulated PCBP2 impaired the functions of EVTs via suppression of WNT5A-mediating ROR2/JNK/MMPs pathway, which may eventually contribute to the development of PE.

Wnt-5a is a protein that is encoded by the WNT5A gene and is a ligand for the receptor tyrosine kinase-like orphan receptor 2 (ROR2). However, its biological impact on clear cell renal cell carcinoma (ccRCC) remains unclear. In this study, the prognostic significance of concurrent WNT5A and ROR2 expression levels was observed to predict unfavorable overall survival and disease-specific survival. High Wnt-5a expression was detected in a ccRCC cell line panel but not in HK-2 cells, a normal proximal tubular cell line. Inhibition of DNA methyltransferase by 5-azacytidine in 786-O and Caki-2 cells resulted in Wnt-5a up-regulation, indicating potential epigenetic modification. Furthermore, the results revealed the repression of cell movement in vitro and metastatic colonization in vivo on WNT5A and ROR2 knockdown. The suppressions of angiogenesis in vivo and tubular-like structure formation in endothelial cells in vitro were also observed after silencing WNT5A and ROR2 expression. In addition, alteration in the downstream gene signature of the Wnt-5a-ROR2 signaling was discovered to be similar to that in metastasis-associated gene 1-β-catenin axis. Moreover, prunetin treatment was found to reverse the gene signature derived from Wnt-5a-ROR2 signaling activation and to abolish ccRCC cell migration and proliferation. Overall, this study demonstrates the clinical and functional significance of the Wnt-5a-ROR2 axis and identifies prunetin as a potential precision medicine for patients with ccRCC harboring aberrant Wnt-5a-ROR2 signaling pathways.

Ventricular septal defects (VSDs) are recognized as one of the commonest congenital heart diseases (CHD), accounting for up to 40% of all cardiac malformations, and occur as isolated CHDs as well as together with other cardiac and extracardiac congenital malformations in individual patients and families. The genetic etiology of VSD is complex and extraordinarily heterogeneous. Chromosomal abnormalities such as aneuploidy and structural variations as well as rare point mutations in various genes have been reported to be associated with this cardiac defect. This includes both well-defined syndromes with known genetic cause (e.g., DiGeorge syndrome and Holt-Oram syndrome) and so far undefined syndromic forms characterized by unspecific symptoms. Mutations in genes encoding cardiac transcription factors (e.g., NKX2-5 and GATA4) and signaling molecules (e.g., CFC1) have been most frequently found in VSD cases. Moreover, new high-resolution methods such as comparative genomic hybridization enabled the discovery of a high number of different copy number variations, leading to gain or loss of chromosomal regions often containing multiple genes, in patients with VSD. In this chapter, we will describe the broad genetic heterogeneity observed in VSD patients considering recent advances in this field.

The receptor tyrosine kinase ROR2 mediates noncanonical WNT5A signaling to orchestrate tissue morphogenetic processes, and dysfunction of the pathway causes Robinow syndrome, brachydactyly B, and metastatic diseases. The domain(s) and mechanisms required for ROR2 function, however, remain unclear. We solved the crystal structure of the extracellular cysteine-rich (CRD) and Kringle (Kr) domains of ROR2 and found that, unlike other CRDs, the ROR2 CRD lacks the signature hydrophobic pocket that binds lipids/lipid-modified proteins, such as WNTs, suggesting a novel mechanism of ligand reception. Functionally, we showed that the ROR2 CRD, but not other domains, is required and minimally sufficient to promote WNT5A signaling, and Robinow mutations in the CRD and the adjacent Kr impair ROR2 secretion and function. Moreover, using function-activating and -perturbing antibodies against the Frizzled (FZ) family of WNT receptors, we demonstrate the involvement of FZ in WNT5A-ROR signaling. Thus, ROR2 acts via its CRD to potentiate the function of a receptor super-complex that includes FZ to transduce WNT5A signals.

Ror-family receptors, Ror1 and Ror2, are type I transmembrane proteins that possess an extracellular cysteine-rich domain, which is conserved throughout the Frizzled-family receptors and is a binding site for Wnt ligands. Both Ror1 and Ror2 function primarily as receptors or co-receptors for Wnt5a to activate the β-catenin-independent, non-canonical Wnt signaling, thereby regulating cell polarity, migration, proliferation, and differentiation depending on the context. Ror1 and Ror2 are expressed highly in many tissues during embryogenesis but minimally or scarcely in adult tissues, with some exceptions. In contrast, Ror1 and Ror2 are expressed in many types of cancers, and their high expression often contributes to the progression of the disease. Therefore, Ror1 and Ror2 have been proposed as potential targets for the treatment of the malignancies. In this review, we provide an overview of the regulatory mechanisms of Ror1/Ror2 expression and discuss how Wnt5a-Ror1/Ror2 signaling is mediated and regulated by their interacting proteins.

Astrocytes, a type of glial cells, play critical roles in promoting the protection and repair of damaged tissues after brain injury. Inflammatory cytokines and growth factors can affect gene expression in astrocytes in injured brains, but signaling pathways and transcriptional mechanisms that regulate tissue protective functions of astrocytes are still poorly understood. In this study, we investigated the molecular mechanisms regulating the function of reactive astrocytes induced in mouse models of stab wound (SW) brain injury and collagenase-induced intracerebral hemorrhage (ICH). We show that basic fibroblast growth factor (bFGF), whose expression is up-regulated in mouse brains after SW injury and ICH, acts synergistically with inflammatory cytokines to activate E2F1-mediated transcription of a gene encoding the Ror-family protein Ror2, a receptor for Wnt5a, in cultured astrocytes. We also found that subsequent activation of Wnt5a/Ror2 signaling in astrocytes results in nuclear accumulation of antioxidative transcription factor Nrf2 at least partly by increased expression of p62/Sqstm1, leading to promoted expression of several Nrf2 target genes, including heme oxygenase 1. Finally, we provide evidence demonstrating that enhanced activation of Wnt5a/Ror2 signaling in astrocytes reduces cellular damage caused by hemin, a degradation product of hemoglobin, and promotes repair of the damaged blood brain barrier after brain hemorrhage.

BACKGROUND: Wnt5a is the key ligand of the noncanonical Wnt pathway, and receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a receptor associated with Wnt5a. The association between the noncanonical Wnt-signaling pathway and carcinogenesis in hepatocellular carcinoma (HCC) is unclear. This study investigated the significance of ROR2 expression in HCC.
METHODS: The study examined ROR2 expression in liver cancer cell lines. Immunohistochemical staining of ROR2 was performed on 243 resected HCC specimens. The study investigated ROR2 expression and its association with clinicopathologic factors and prognosis.
RESULTS: Findings showed that ROR2 was expressed in well-differentiated Huh7 and HepG2 cells, but not in poorly differentiated HLE and HLF cells. Expression of ROR2 was positive in 147 (60.5%) and negative in 96 (39.5%) HCC specimens. A significant association was shown between ROR2 negativity and high alpha-fetoprotein (AFP) level (P = 0.006), poor differentiation (P = 0.015), and Wnt5a negativity (P = 0.024). The 5-year overall survival (OS) rate for the ROR2-negative group (64.2 %) tended to be worse than for the ROR2-positive group (73.8%), but the difference was not significant (P = 0.312). The 5-year OS rate was 78.7% for the ROR2+Wnt5a+ group, 71.3 % for the ROR2+Wnt5a- group, 80.8% for the ROR2-Wnt5a+ group, and 60.5 % for the ROR2-Wnt5a- group. The OS in the ROR2-Wnt5a- group was significantly poorer than in the ROR2+Wnt5a+ group (P = 0.030). The multivariate analysis showed that Wnt5a-ROR2- was an independent prognostic factor (hazard ratio, 2.058; 95% confidence interval, 1.013-4.180; P = 0.045).
CONCLUSIONS: The combination of ROR2 and Wnt5a may be a prognostic indicator for HCC. The Wnt5a/ROR2 signal pathway may be involved in the differentiation of HCC. This pathway may be a new therapeutic target for HCC.

Lineage plasticity is a form of therapy-induced drug resistance. In prostate cancer, androgen receptor (AR) pathway inhibitors potentially lead to the accretion of tumor relapse with loss of AR signaling and a shift from a luminal state to an alternate program. However, the molecular and signaling mechanisms orchestrating the development of lineage plasticity under the pressure of AR-targeted therapies are not fully understood. Here, a survey of receptor tyrosine kinases (RTKs) identifies ROR2 as the top upregulated RTK following AR pathway inhibition, which feeds into lineage plasticity by promoting stem-cell-like and neuronal networks. Mechanistically, ROR2 activates the ERK/CREB signaling pathway to modulate the expression of the lineage commitment transcription factor ASCL1. Collectively, our findings nominate ROR2 as a potential therapeutic target to reverse the ENZ-induced plastic phenotype and potentially re-sensitize tumors to AR pathway inhibitors.

We aimed to determine whether receptor tyrosine kinase-like orphan receptor 2 (ROR2) is involved in the occurrence of acute lung injury (ALI) by an animal study and explore the effect of ROR2 downregulation on lipopolysaccharide (LPS)-treated human lung carcinoma A549 cells by a cytological study.
Murine models of ALI were successfully constructed by intratracheal instillation of LPS. Meanwhile, A549 cell line stimulated with LPS was used for a cytological study. The expression of ROR2 and its effect on proliferation, cell cycle, apoptosis, and inflammation were detected.
It was found that LPS administration markedly inhibited the cell proliferation, resulted in cell cycle arrest at G1 phage, elevated levels of pro-inflammatory cytokines and apoptosis rate of A549 cells. However, LPS-mediated adverse effects mentioned above were significantly ameliorated by downregulation of ROR2 in comparison with LPS treatment. In addition, administration of ROR2 siRNA notably decreased the phosphorylation level of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in LPS-challenged A549 cells.
Thus, the present data indicate that downregulation of ROR2 may decrease LPS-induced inflammatory responses and cell apoptosis through inhibiting JNK and ERK signaling pathway, which attenuates ALI.