Armored TGFßRIIDN ROR1-CAR T cells reject solid tumors and resist suppression by constitutively-expressed and treatment-induced TGFß1.

BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy target receptor tyrosine kinase-like orphan receptor 1 (ROR1) is broadly expressed in hematologic and solid tumors, however clinically-characterized ROR1-CAR T cells with single chain variable fragment (scFv)-R12 targeting domain failed to induce durable remissions, in part due to the immunosuppressive tumor microenvironment (TME). Herein, we describe the development of an improved ROR1-CAR with a novel, fully human scFv9 targeting domain, and augmented with TGFßRIIDN armor protective against a major TME factor, transforming growth factor beta (TGFß). METHODS: CAR T cells were generated by lentiviral transduction of enriched CD4+ and CD8+ T cells, and the novel scFv9-based ROR1-CAR-1 was compared with the clinically-characterized ROR1-R12-scFv-based CAR-2 in vitro and in vivo. RESULTS: CAR-1 T cells exhibited greater CAR surface density than CAR-2 when normalized for %CAR+, and produced more interferon (IFN)-γ tumor necrosis factor (TNF)-α and interleukin (IL)-2 in response to hematologic (Jeko-1, RPMI-8226) and solid (OVCAR-3, Capan-2, NCI-H226) tumor cell lines in vitro. In vivo, CAR-1 and CAR-2 both cleared hematologic Jeko-1 lymphoma xenografts, however only CAR-1 fully rejected ovarian solid OVCAR-3 tumors, concordantly with greater expansion of CD8+ and CD4+CAR T cells, and enrichment for central and effector memory phenotype. When equipped with TGFß-protective armor TGFßRIIDN, CAR-1 T cells resisted TGFß-mediated pSmad2/3 phosphorylation, as compared with CAR-1 alone. When co-cultured with ROR-1+ AsPC-1 pancreatic cancer line in the presence of TGFß1, armored CAR-1 demonstrated improved recovery of killing function, IFN-γ, TNF-α and IL-2 secretion. In mouse AsPC-1 pancreatic tumor xenografts overexpressing TGFß1, armored CAR-1, in contrast to CAR-1 alone, achieved complete tumor remissions, and yielded accelerated expansion of CAR+ T cells, diminished circulating active TGFß1, and no apparent toxicity or weight loss. Unexpectedly, in AsPC-1 xenografts without TGFß overexpression, TGFß1 production was specifically induced by ROR-1-CAR T cells interaction with ROR-1 positive tumor cells, and the TGFßRIIDN armor conferred accelerated tumor clearance. CONCLUSIONS: The novel fully human TGFßRIIDN-armored ROR1-CAR-1 T cells are highly potent against ROR1-positive tumors, and withstand the inhibitory effects of TGFß in solid TME. Moreover, TGFß1 induction represents a novel, CAR-induced checkpoint in the solid TME, which can be circumvented by co-expressing the TGßRIIDN armor on T cells.

[Genetic analysis of a Chinese pedigree affected with Brachydactyly type B1 due to a novel variant of ROR2 gene].

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with Brachydactyly type B1 (BDB1) through whole exome sequencing (WES). METHODS: A BDB1 pedigree admitted to the Affiliated Women and Children's Hospital of Qingdao University on June 25, 2021 was selected as the study subject. Clinical data of the pedigree was collected with informed consent. WES was carried out for the proband, and candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: WES and Sanger sequencing had identified a heterozygous c.2257delT variant in the ROR2 gene of the proband and his affected father, which has conformed to an autosomal dominant pattern of inheritance. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified to be likely pathogenic (PVS1_Strong+PM2 Supporting+PP4). CONCLUSION: The c.2257delT variant of the ROR2 gene was unreported previously and is strongly correlated with the BDB1-like phenotype in this pedigree. Above finding has enriched the mutational spectrum of the ROR2 gene and facilitated the diagnosis and genetic counseling for this pedigree.

Dihydroartemisinin inhibits tumor progress via blocking ROR1-induced STAT3-activation in non-small cell lung cancer.

In non-small cell lung cancer (NSCLC), identifying a component with certain molecular targets can aid research on cancer treatment. Dihydroartemisinin (DHA) is a semisynthetic derivative of artemisinin which induced the anti-cancer effects via the STAT3 signaling pathway, but the underlying molecular mechanism is still elusive. In this study, we first proved that DHA prohibits the growth of tumors both in vitro and in vivo. Data from transcriptomics showed that DHA reduced the expression level of the genes involved in cell cycle-promoting and anti-apoptosis, and most importantly, DHA restricted the expression level of receptor tyrosine kinase-like orphan receptor 1 (ROR1) which has been reported to have abnormal expression on tumor cells and had close interaction with STAT3 signaling. Then, we performed comprehensive experiments and found that DHA remarkably decreased the expression of ROR1 at both mRNA and protein levels and it also diminished the phosphorylation level of STAT3 in NSCLC cell lines. In addition, our data showed that exogenously introduced ROR1 could significantly enhance the phosphorylation of STAT3 while blocking ROR1 had the opposite effects indicating that ROR1 plays a critical role in promoting the activity of STAT3 signaling. Finally, we found that ROR1 overexpression could partially reverse the decreased activity of STAT3 induced by DHA which indicates that DHA-induced anti-growth signaling is conferred, at least in part, through blocking ROR1-mediated STAT3 activation. In summary, our study indicates that in NSCLC, ROR1 could be one of the critical molecular targets mediating DHA-induced STAT3 retardation.

Characterization and impact of non-canonical WNT signaling on outcomes of urothelial carcinoma.

BACKGROUND: Non-canonical WNT family (WNT5A pathway) signaling via WNT5A through ROR1 and its partner, ROR2, or Frizzled2 (FZD2) is linked to processes driving tumorigenesis and therapy resistance. We utilized a large dataset of urothelial carcinoma (UC) tumors to characterize non-canonical WNT signaling through WNT5A, ROR1, ROR2, or FZD2 expression. METHODS: NextGen Sequencing of DNA (592 genes or WES)/RNA (WTS) was performed for 4125 UC tumors submitted to Caris Life Sciences. High and low expression of WNT5A, ROR1, ROR2, and FZD2 was defined as ≥ top and

Role of the Ror family receptors in Wnt5a signaling.

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 ß-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.

Prenatal diagnosis of ROR-2 related Robinow syndrome presenting with fetal ultrasound findings of mesomelia, vertebral, digital and genital abnormalities.

Autosomal recessive ROR2-Robinow syndrome is caused by pathogenic variants in the ROR2 gene. Fetal ultrasound done on our patient at 24 + 3/7 weeks gestation showed macrocephaly, brachycephaly, flat face, prominent forehead, mild frontal bossing, lower thoracic hemivertebrae, digital abnormalities and micropenis. Fetal trio whole exome sequencing done on amniocytes showed two pathogenic compound heterozygous variants in the ROR2 gene, c.1324 C > T; p.(Arg442*) maternally inherited and c.1366dup; p.(Leu456Profs*3) apparently de novo. c.1324 C > T; p.(Arg442*) is a nonsense variant resulting in protein truncation reported to be associated with RRS3. c.1366dup; p.(Leu456Profs*3) is a frameshift variant predicted to result in protein truncation reported to segregate with the disease in multiple affected individuals from a single large family with distal symphalangism of the fourth finger. Fetal autopsy following pregnancy termination showed a large head with low-set ears, facial abnormalities, mesomelic bone shortening, hemivertebra, fused S3 and S4 vertebral bodies, several fused rib heads and short penis with buried shaft.

A Crosstalk between the Receptor Tyrosine Kinase-Like Orphan Receptors ROR1/2 and S1P Signaling Pathways in Lung Cancer.

OBJECTIVE: Availability of multimodal treatment strategies, including targeted therapies and immunotherapies, have improved the survival of non-small cell lung carcinoma (NSCLC). However, some patients still progress or respond poorly due to inherent resistance, acquired resistance, or lack of druggable driver mutations. Sphingosine-1-phosphate (S1P) and receptor tyrosine kinase-like orphan receptor (ROR1/2) signaling pathways are activated during lung carcinogenesis. METHODS: In this study, we have evaluated the crosstalk of S1P and ROR1/2 signaling pathways in lung cancer cells. RESULTS: S1P treatment of lung cancer cells decreases ROR1 and ROR2 transcript levels. While treatment with PF-543, a pharmacological SphK1 inhibitor or genetic knockdown of SPHK1 by shRNA, raises ROR1 and ROR2. Furthermore, simultaneous inhibition of SphK1 along with ROR1 reduced the migration of lung cancer cells. CONCLUSION: These findings demonstrate the reciprocal regulation of both pathways, suggesting that both pathways have an inverse relation i.e, in the absence of one pathway, another pathway may take charge of the other pathway. Therefore, simultaneously targeting both pathways could serve as a potential therapeutic target for lung cancer treatment.

Quantitative Investigation of Neuroprotective Role of ROR1 in a Cell Culture Model of Alzheimer's Disease.

Cytoskeletal and microtubule atrophy are major hallmarks of Alzheimer's disease (AD). A method to investigate endogenous proteins that can interact/stabilize the cytoskeleton (under pathological cues) is rare. Here, we describe how receptor tyrosine kinase-like orphan receptor 1 (ROR1), a receptor tyrosine kinase (RTK), can act as a neuroprotective molecule by promoting neurite outgrowth, stabilizing cytoskeletal components, and altering the dynamics of actin assembly in a cell culture model of AD.

ROR2/Wnt5a Signaling Regulates Directional Cell Migration and Early Tumor Cell Invasion in Ovarian Cancer.

Adhesion to and clearance of the mesothelial monolayer are key early events in metastatic seeding of ovarian cancer. ROR2 is a receptor tyrosine kinase that interacts with Wnt5a ligand to activate noncanonical Wnt signaling and has been previously shown to be upregulated in ovarian cancer tissue. However, no prior study has evaluated the mechanistic role of ROR2 in ovarian cancer. Through a cellular high-throughput genetic screen, we independently identified ROR2 as a driver of ovarian tumor cell adhesion and invasion. ROR2 expression in ovarian tumor cells serves to drive directed cell migration preferentially toward areas of high Wnt5a ligand, such as the mesothelial lined omentum. In addition, ROR2 promotes ovarian tumor cell adhesion and clearance of a mesothelial monolayer. Depletion of ROR2, in tumor cells, reduces metastatic tumor burden in a syngeneic model of ovarian cancer. These findings support the role of ROR2 in ovarian tumor cells as a critical factor contributing to the early steps of metastasis. Therapeutic targeting of the ROR2/Wnt5a signaling axis could provide a means of improving treatment for patients with advanced ovarian cancer. IMPLICATIONS: This study demonstrates that ROR2 in ovarian cancer cells is important for directed migration to the metastatic niche and provides a potential signaling axis of interest for therapeutic targeting in ovarian cancer.

ROR1 expression in mature B lymphoid neoplasms by flow cytometry.

Immunophenotyping by flow cytometry is an integral part of the diagnosis and classification of leukemias/lymphomas. The expression of ROR1 associated with chronic B lymphocytic leukemia (CLL) is well described in the literature, both in its diagnosis and in the follow-up of minimal residual disease (MRD) research, however, there are few studies regarding the expression pattern of ROR1 in other subtypes of mature B lymphoid neoplasms. With the aim of evaluating the expression of ROR1 and associating it with the expression of other important markers for the differentiation of mature B lymphoid neoplasms (MBLN), 767 samples of cases that entered our laboratory for immunophenotyping with clinical suspicion of MBLN were studied. ROR1 expression is predominant in CD5+/CD10- neoplasms. Overall, positive ROR1 expression was observed in 461 (60.1%) cases. The CD5+/CD10- group had a significantly higher proportion of ROR1 positive samples (89.9%) and more brightly expressed ROR1 than the other groups. Our results highlight the importance of evaluating ROR1 expression in the diagnosis of MBLN to contribute to the differential diagnosis, and possibly therapy of mainly CLL, and indicate that this marker could be considered as a useful addition to immunophenotypic panels, particularly for more challenging cases.

ROR2 expression predicts human induced pluripotent stem cell differentiation into neural stem/progenitor cells and GABAergic neurons.

Despite the development of various in vitro differentiation protocols for the efficient derivation of specific cell types, human induced pluripotent stem cell (hiPSC) lines have varing ability to differentiate into specific lineages. Therefore, surrogate markers for accurately predicting the differentiation propensity of hiPSC lines may facilitate cell-based therapeutic product development and manufacture. We attempted to identify marker genes that could predict the differentiation propensity of hiPSCs into neural stem/progenitor cells (NS/PCs). Using Spearman's rank correlation coefficients, we investigated genes in the undifferentiated state, the expression levels of which were significantly correlated with the neuronal differentiation propensity of several hiPSC lines. Among genes significantly correlated with NS/PC differentiation (P < 0.01), we identified ROR2 as a novel predictive marker. ROR2 expression in hiPSCs was negatively correlated with NS/PC differentiation tendency, regardless of the differentiation method, whereas its knockdown enhanced differentiation. ROR2 regulates NS/PC differentiation, suggesting that ROR2 is functionally essential for NS/PC differentiation. Selecting cell lines with relatively low ROR2 expression facilitated identification of hiPSCs that can differentiate into NS/PCs. Cells with ROR2 knockdown showed increased efficiency of differentiation into forebrain GABAergic neurons compared to controls. These findings suggest that ROR2 is a surrogate marker for selecting hiPSC lines appropriate for NS/PC and GABAergic neuronal differentiations.

ROR2 homodimerization is sufficient to activate a neuronal Wnt/calcium signaling pathway.

Wnt signaling plays a key role in the mature CNS by regulating trafficking of NMDA-type glutamate receptors and intrinsic properties of neurons. The Wnt receptor ROR2 has been identified as a necessary component of the neuronal Wnt5a/Ca2+ signaling pathway that regulates synaptic and neuronal function. Since ROR2 is considered a pseudokinase, its mechanism for downstream signaling upon ligand binding has been controversial. It has been suggested that its role is to function as a coreceptor of a G-protein-coupled Wnt receptor of the Frizzled family. We show that chemically induced homodimerization of ROR2 is sufficient to recapitulate key signaling events downstream of receptor activation in neurons, including PKC and JNK kinases activation, elevation of somatic and dendritic Ca2+ levels, and increased trafficking of NMDARs to synapses. In addition, we show that homodimerization of ROR2 induces phosphorylation of the receptor on Tyr residues. Point mutations in the conserved but presumed nonfunctional ATP-binding site of the receptor prevent its phosphorylation, as well as downstream signaling. This suggests an active kinase domain. Our results indicate that ROR2 can signal independently of Frizzled receptors to regulate the trafficking of a key synaptic component. Additionally, they suggest that homodimerization can overcome structural conformations that render the tyrosine kinase inactive. A better understanding of ROR2 signaling is crucial for comprehending the regulation of synaptic and neuronal function in normal brain processes in mature animals.

ROR2 deficit may induce the tetralogy of Fallot via down-regulating of ß-catenin/SOX3/HSPA6 in vitro and in vivo.

Tetralogy of Fallot (TOF) is the highly conventional appearance of cyanotic congenital heart disease. Our study aimed to assess the involvement of receptor tyrosine kinase-like orphan receptor 2 (ROR2) in TOF and elucidate the specific mechanism. Upon investigation of human tissue samples, we observed a decrease in ROR2 expression in TOF patients compared to healthy control individuals. Transcriptome analysis revealed diminished ROR2 expression in TOF pathological samples relative to normal tissues. Of the 2246 genes that exhibited altered expression, 886 were upregulated, while 1360 were down-regulated. KEGG analysis and GO analysis of the differentially expressed genes indicated that these genes were significantly enriched in the Wnt signalling pathway, apoptosis and cardiac development function. Importantly, ROR2 was the only gene shared among the three pathways. Furthermore, interference with ROR2 promotes apoptosis and curtails cell proliferation in vitro. The knockdown of the ROR2 gene in AC16 cells resulted in a significant decrease in Edu-positive cells. Flow cytometry studies indicated an increase in the percentage of cells in the S phase. In contrast, the G2/M cell cycle transition was blocked in the ROR2-knockdown group, leading to a significant increase in apoptosis. Moreover, the CCK-8 cell viability assay demonstrated a reduced proliferation in the ROR2-knockdown group. Furthermore, both in vivo and in vitro data indicated that the expression of HSPA6 (Recombinant Heat Shock 70 kDa Protein6), an essential gene enriched in cardiac tissue and associated with apoptosis, was down-regulated following ROR2 knockdown mediated by the ß-catenin/SOX3 signalling pathway. In conclusion, low expression of ROR2 plays a crucial role in the occurrence and development of TOF, which may be related to the downregulation of HSPA6 through the ß-catenin/SOX3 signalling pathway.

ROR1-AS1 might promote in vivo and in vitro proliferation and invasion of cholangiocarcinoma cells.

Long non-coding RNAs (lncRNAs) play important roles in many pathophysiological processes, including cancer progression. Namely, lncRNA Receptor-tyrosine-kinase-like orphan receptor-1 antisense 1 (ROR1-AS1) is crucial for cancer occurrence and progression in organs such as the liver or bladder. However, its expression and role in cholangiocarcinoma (CCA) have not been thoroughly explored.Firstly, we assessed cell viability, proliferation, invasion, and migration using three cell lines (HuCCT-1, QBC399, and RBE) to explore the biological characteristics of ROR1-AS1 in CCA. Secondly, to determine the in vivo effect of ROR1-AS1 on tumor growth, ROR1-AS1 knockdown (KD) HuCCT-1 cells were subcutaneously injected into nude mice to evaluate tumor growth. Finally, we conducted a bioinformatic analysis to confirm the role of ROR1-AS1 in the prognosis and immunity of CCA.In this study, we found that lncRNA ROR1-AS1 was increased in CCA samples and patients with higher ROR1-AS1 expression had a shorter overall survival period. siRNA-mediated KD of ROR1-AS1 significantly reduced cell proliferation and inhibited the migration of CCA cells. In addition, ROR1-AS1 KD HuCCT-1 cells injected into nude mice grew slower than normal CCA cells.In summary, our results show that ROR1-AS1 can promote CCA progression and might serve as a new target for diagnosis and treatment of CCA.

ASCL1 is activated downstream of the ROR2/CREB signaling pathway to support lineage plasticity in prostate cancer.

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.

The onco-embryonic antigen ROR1 is a target of chimeric antigen T cells for colorectal cancer.

Colorectal cancer is globally ranked second in both incidence and mortality rate. It usually develops during the middle or late stages of diagnosis, and is characterized by easy metastasis, poor prognosis, and a significant decline in postoperative quality of life. ROR1 is an excellent oncoembryonic antigen in numerous immunotherapy treatments for tumors. Additionally, it is overexpressed in colorectal cancer. To fill the void in CRC treatment with ROR1 as a target of CAR-T immunotherapy, we designed and prepared antiROR1-CART. This third-generation CAR-T cell can effectively inhibit the growth of colorectal cancer in vitro and in vivo.

ROR2/PCP a New Pathway Controlling Endothelial Cell Polarity Under Flow Conditions.

BACKGROUND: Endothelial cells (ECs) are sensitive to physical forces created by blood flow, especially to laminar shear stress. Among the cell responses to laminar flow, EC polarization against the flow direction emerges as a key event, particularly during the development and remodeling of the vascular network. EC adopt an elongated planar cell shape with an asymmetrical distribution of intracellular organelles along the axis of blood flow. This study aimed to investigate the involvement of planar cell polarity via the receptor ROR2 (receptor tyrosine kinase-like orphan receptor 2) in endothelial responses to laminar shear stress. METHODS: We generated a genetic mouse model with EC-specific deletion of Ror2, in combination with in vitro approaches involving loss- and gain-of-function experiments. RESULTS: During the first 2 weeks of life, the endothelium of the mouse aorta undergoes a rapid remodeling associated with a loss of EC polarization against the flow direction. Notably, we found a correlation between ROR2 expression and endothelial polarization levels. Our findings demonstrate that deletion of Ror2 in murine ECs impaired their polarization during the postnatal development of the aorta. In vitro experiments further validated the essential role of ROR2 in both EC collective polarization and directed migration under laminar flow conditions. Exposure to laminar shear stress triggered the relocalization of ROR2 to cell-cell junctions where it formed a complex with VE-Cadherin and ß-catenin, thereby regulating adherens junctions remodeling at the rear and front poles of ECs. Finally, we showed that adherens junctions remodeling and cell polarity induced by ROR2 were dependent on the activation of the small GTPase Cdc42. CONCLUSIONS: This study identified ROR2/planar cell polarity pathway as a new mechanism controlling and coordinating collective polarity patterns of EC during shear stress response.

The Role of ROR1 in Chemoresistance and EMT in Endometrial Cancer Cells.

Background and Objectives: Receptor tyrosine kinase-like orphan receptor type 1 (ROR1) plays a critical role in embryogenesis and is overexpressed in many malignant cells. These characteristics allow ROR1 to be a potential new target for cancer treatment. The aim of this study was to investigate the role of ROR1 through in vitro experiments in endometrial cancer cell lines. Materials and Methods: ROR1 expression was identified in endometrial cancer cell lines using Western blot and RT-qPCR. The effects of ROR1 on cell proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) markers were analyzed in two endometrial cancer cell lines (HEC-1 and SNU-539) using either ROR1 silencing or overexpression. Additionally, chemoresistance was examined by identifying MDR1 expression and IC50 level of paclitaxel. Results: The ROR1 protein and mRNA were highly expressed in SNU-539 and HEC-1 cells. High ROR1 expression resulted in a significant increase in cell proliferation, migration, and invasion. It also resulted in a change of EMT markers expression, a decrease in E-cadherin expression, and an increase in Snail expression. Moreover, cells with ROR1 overexpression had a higher IC50 of paclitaxel and significantly increased MDR1 expression. Conclusions: These in vitro experiments showed that ROR1 is responsible for EMT and chemoresistance in endometrial cancer cell lines. Targeting ROR1 can inhibit cancer metastasis and may be a potential treatment method for patients with endometrial cancer who exhibit chemoresistance.

YAP/BRD4-controlled ROR1 promotes tumor-initiating cells and hyperproliferation in pancreatic cancer.

Tumor-initiating cells are major drivers of chemoresistance and attractive targets for cancer therapy, however, their identity in human pancreatic ductal adenocarcinoma (PDAC) and the key molecules underlying their traits remain poorly understood. Here, we show that a cellular subpopulation with partial epithelial-mesenchymal transition (EMT)-like signature marked by high expression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) is the origin of heterogeneous tumor cells in PDAC. We demonstrate that ROR1 depletion suppresses tumor growth, recurrence after chemotherapy, and metastasis. Mechanistically, ROR1 induces the expression of Aurora kinase B (AURKB) by activating E2F through c-Myc to enhance PDAC proliferation. Furthermore, epigenomic analyses reveal that ROR1 is transcriptionally dependent on YAP/BRD4 binding at the enhancer region, and targeting this pathway reduces ROR1 expression and prevents PDAC growth. Collectively, our findings reveal a critical role for ROR1high cells as tumor-initiating cells and the functional importance of ROR1 in PDAC progression, thereby highlighting its therapeutic targetability.

Downregulation of ROR2 attenuates LPS-induced A549 cell injury through JNK and ERK signaling pathways.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.