Receptor tyrosine kinase-like orphan receptor serves as a potential target in cancer immunotherapy.

Receptor tyrosine kinase-like orphan receptor (ROR), consisting of ROR1 and ROR2, is a conserved family of receptor tyrosine kinase superfamily that plays crucial roles during embryonic development with limited expression in adult normal tissues. However, it is overexpressed in a range of hematological malignancies and solid tumors and functions in cellular processes including cell survival, polarity, and migration, serving as a potential target in cancer immunotherapy. This review summarizes the expression and structure of ROR in developmental morphogenesis and its function in cancers associated with Wnt5a signaling and highlights the cancer immunotherapy strategies targeting ROR.

Diagnostic and prognostic value of ROR1 antigen in patients with chronic lymphocytic leukemia / 中华检验医学杂志

Objective:To detect the expression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) antigen in chronic lymphocytic leukemia (CLL) and evaluate its diagnostic value and explore its correlation with the abnormalities of genetics and molecular biology.Methods:All of 209 newly diagnosed B-cell chronic lymphoproliferative disorders (B-CLPD) patients who were admitted to the First Affiliated Hospital of Nanjing Medical University (Jiangsu Provincial People′s Hospital) from November 2020 to November 2021 were collected retrospectively, including 70 cases of CLL with typical phenotype, 16 cases of CLL with atypical phenotype, 14 cases of MCL, and 109 cases of other types of B-CLPD. Multi-parameter flow cytometry (FCM) was used to detect the expression levels of ROR1 in tumor cells of 209 patients. And then the diagnostic value of ROR1 in CLL patients and its correlation with the genetic and molecular biological abnormalities were analyzed by c2 test and fourfold table assessment.Results:The positive expression rate of ROR1 in CLL patients was significantly higher than that in non-CLL patients (78%>11%, P<0.001); there was no significant difference of ROR1 expression between typical phenotype CLL and atypical phenotype CLL (81%>63%, P>0.05). The positive expression rate of ROR1 in atypical phenotype CLL was significantly higher than that in MCL (63%>21%, P<0.05). Additionally, there was significant difference in detection rate of chromosomal abnormalities between ROR1 +CLL group and ROR1 -CLL group. The detection rate of complex karyotype in ROR1 +CLL group was higher than that in ROR1 -CLL group (34%>14%, P<0.05). The CLL patients over 60 years old had higher ROR1 positive rate ( P<0.05). Conclusions:ROR1 can be helpful in the diagnosis of CLL, especially in the differential diagnosis of atypical phenotype CLL, MCL and other types of B-CLPD. Patients with ROR1 positive expression were older and more likely to detect complex chromosomal karyotypes.

Do patients with oral squamous cell carcinoma express receptor tyrosine kinase-like orphan receptor 1? Results of an observational study.

CONTEXT: The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a transmembrane protein of the receptor tyrosine kinase family. The expression of ROR1 has been linked to cancers. AIMS: This study aimed to investigate the expression of ROR1 in oral squamous cell carcinoma (OSCC). SETTINGS AND DESIGN: This prospective observational study was conducted at a tertiary referral center for treatment of oral carcinoma from November 2013 to December 2016. SUBJECTS AND METHODS: One-step quantitative reverse transcription-polymerase chain reaction (30 oral cancer tissues and ten normal oral tissue samples) was performed to characterize the expression of the ROR1 gene in oral cancer. STATISTICAL ANALYSIS USED: Analyses of all tumor samples were carried out at least twice, and the mean value was calculated. The differences in ROR1 messenger RNA (mRNA) expression between OSCC tissue and nontumorous gingival tissue was statistically analyzed using Mann-Whitney U-test. The correlations between the clinicopathological parameters and ROR1 mRNA expression were analyzed using Kruskal-Wallis test χ2 value. RESULTS: There were 17, 5, 3 and 1 cases of OSCC of buccal mucosa, tongue and lower alveolus lip, respectively. Nearly 88.5% of cases had a history of tobacco consumption. The most common OSCC type was T2N1M0. There was no difference in ROR1 fold change between controls and cases (P = 0.06), but there was a trend for downregulation of ROR1 expression from controls to cases. Subgroup analysis revealed the downregulation of ROR1 expression in controls versus Grade II that was significant (P = 0.04). CONCLUSIONS: There was no change in the expression of ROR1 between cases and controls. A study involving a larger sample size needs to be formulated and conducted for investigating the relation between expression and regulation of ROR1 in OSCC.

Upregulation of receptor tyrosine kinase-like orphan receptor 2 in idiopathic pulmonary fibrosis.

BACKGROUND/AIMS: Receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a major regulator of Wnt signaling, which is involved in fibroblast dysfunction. Because its role has not been evaluated in idiopathic pulmonary fibrosis (IPF), we examined the clinical implications of ROR2 expression. METHODS: ROR2 mRNA expression was measured using reverse transcription polymerase chain reaction in lung tissue-derived fibroblasts from IPF patients (n = 14) and from controls (n = 10). ROR2 protein was measured using enzyme-linked immunosorbent assay in primary fibroblasts from IPF patients (n = 14) and controls (n = 10), and in bronchoalveolar lavage (BAL) fluids obtained from normal controls (NC; n = 30). IPF patients (n = 84), and other patients with interstitial lung diseases, including nonspecific interstitial pneumonia (NSIP; n = 10), hypersensitivity pneumonitis (HP; n = 10), and sarcoidosis (n = 10). RESULTS: ROR2 mRNA and protein levels were significantly higher in IPF fibroblasts than in controls (p = 0.003, p = 0.0017, respectively). ROR2 protein levels in BAL fluids from patients with IPF were significantly higher than in those from NC (p < 0.001), and from patients with NSIP (p = 0.006), HP (p = 0.004), or sarcoidosis (p = 0.004). Receiver operating characteristic curves showed a clear difference between IPF and NC in ROR2 protein level (area under the curve, 0.890; confidence interval, 0.829 to 0.950; p < 0.001). ROR2 protein levels were significantly higher in GAP stage III than in GAP stages I and II (p = 0.016). CONCLUSION: ROR2 may be related to the development of IPF, and its protein level may be a useful and severity-dependent candidate marker for IPF.

Receptor tyrosine kinases in carcinogenesis.

Receptor tyrosine kinases (RTKs) are cell surface glycoproteins with enzymatic activity involved in the regulation of various important functions. In all-important physiological functions including differentiation, cell-cell interactions, survival, proliferation, metabolism, migration and signaling these receptors are the key players of regulation. Additionally, mutations of RTKs or their overexpression have been described in many human cancers and are being explored as a novel avenue for a new therapeutic approach. Some of the deregulated RTKs observed to be significantly affected in cancers included vascular endothelial growth factor receptor, epidermal growth factor receptor, fibroblast growth factor receptor, RTK-like orphan receptor 1 (ROR1) and the platelet-derived growth factor receptor. These deregulated RTKs offer attractive possibilities for the new anticancer therapeutic approach involving specific targeting by monoclonal antibodies as well as kinase. The present review aimed to highlight recent perspectives of RTK ROR1 in cancer.