ROR1 expression correlated with poor clinical outcome in human ovarian cancer

The antibody-drug conjugate targeting ROR1, NBE-002, is active in high-grade serous ovarian cancer preclinical models

Background

Novel therapeutics are urgently needed for high-grade serous ovarian cancer (HGSOC). We identified the receptor tyrosine kinase-like orphan receptor 1 (ROR1) as a therapeutic target. NBE-002, an antibody-drug conjugate (ADC) consisting of a humanised anti-ROR1 antibody, huXBR1-402, linked to a highly potent anthracycline-derivative (PNU), has activity in ROR1-positive haematologic malignancies.

Objectives

This study explored the anti-cancer effects of NBE-002 alone and in combination with standard HGSOC therapies, carboplatin, paclitaxel and olaparib.

Design

A ROR1-ADC was tested in cell lines and in vivo models of HGSOC.

Methods

Different ROR1-targeting antibodies and payload compositions were constructed and tested in vitro. The dose effect of NBE-002 alone and in combination with carboplatin, paclitaxel or olaparib was analysed in ROR1+ HGSOC cell lines. Growth inhibition and apoptosis were monitored by live cell imaging and combination effects determined. Ten HGSOC PDX models were treated with NBE-002 alone, or in combination with carboplatin or olaparib, over 4 weeks and tumour volume and overall survival evaluated.

Results

Synergistic interaction was observed in two out of five HGSOC cell lines treated with NBE-002 and carboplatin (PEO4 and OC023, chemo-resistant), in one out of five treated with NBE-002 and olaparib (PEO1, BRCA2 mutated, HR deficient) and none of five treated with NBE-002 and paclitaxel. In vivo, NBE-002 exhibited activity in PA-1 xenografts and three HGSOC PDX models with high ROR1 expression, platinum sensitivity and homologous recombination DNA repair deficient (HRD). When NBE-002 was combined with carboplatin, activity was observed in 7 of 10 ROR1-expressing PDX models, regardless of platinum or HRD status. The activity was demonstrated in combination with olaparib in both PDX tested, one HRD and one HRD reverted.

Conclusion

The ROR1-targeting ADC, NBE-002, has therapeutic potential in HGSOC, with single agent activity observed both in vitro and in vivo. Broader clinical applications were evident when NBE-002 was combined with carboplatin or olaparib.

Therapeutic advances in the targeting of ROR1 in hematological cancers

Receptor tyrosine kinases (RTKs) are key cell surface receptors involved in cell communication and signal transduction, with great importance in cell growth, differentiation, survival, and metabolism. Dysregulation of RTKs, such as EGFR, VEGFR, HER2 or ROR, could lead to various diseases, particularly cancers. ROR1 has emerged as a promising target in hematological malignancies. The development of ROR1 targeted therapies is continuously growing leading to remarkable novel therapeutical approaches using mAbs, antibody-drug conjugates, several small molecules or CAR T cells which have shown encouraging preclinical results. In the hematological field, mAbs, small molecules, BiTEs or CAR T cell therapies displayed promising outcomes with the clinical trials data encouraging the use of anti-ROR1 therapies. This paper aims to offer a comprehensive analysis of the current landscape of ROR1-targeted therapies in hematological malignancies marking the innovative approaches with promising preclinical and clinical. Offering a better understanding of structural and functional aspects of ROR1 could lead to new perspectives in targeting a wide spectrum of malignancies.

Exosomal ROR1 in peritoneal fluid identifies peritoneal disseminated PDAC and is associated with poor survival

Background

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest forms of cancer and peritoneal dissemination is one major cause for this poor prognosis. Exosomes have emerged as promising biomarkers for gastrointestinal cancers and can be found in all kinds of bodily fluids, also in peritoneal fluid (PF). This is a unique sample due to its closeness to gastrointestinal malignancies. The receptor tyrosine kinase-like orphan receptor 1 (ROR1) has been identified as a potential biomarker in human cancers and represents a promising target for an immunotherapy approach, which could be considered for future treatment strategies. Here we prospectively analyzed the exosomal surface protein ROR1 (exo-ROR1) in PF in localized PDAC patients (PER-) on the one hand and peritoneal disseminated tumor stages (PER+) on the other hand followed by the correlation of exo-ROR1 with clinical-pathological parameters.

Methods

Exosomes were isolated from PF and plasma samples of non-cancerous (NC) (n = 15), chronic pancreatitis (CP) (n = 4), localized PDAC (PER-) (n = 18) and peritoneal disseminated PDAC (PER+) (n = 9) patients and the surface protein ROR1 was detected via FACS analysis. Additionally, soluble ROR1 in PF was analyzed. ROR1 expression in tissue was investigated using western blots (WB), qPCR, and immunohistochemistry (IHC). Exosome isolation was proven by Nano Tracking Analysis (NTA), WB, Transmission electron microscopy (TEM), and BCA protein assay. The results were correlated with clinical data and survival analysis was performed.

Results

PDAC (PER+) patients have the highest exo-ROR1 values in PF and can be discriminated from NC (p <0.0001), PDAC (PER-) (p <0.0001), and CP (p = 0.0112). PDAC (PER-) can be discriminated from NC (p = 0.0003). In plasma, exo-ROR1 is not able to distinguish between the groups. While there is no expression of ROR1 in the exocrine pancreatic tissue, PDAC and peritoneal metastasis show expression of ROR1. High exo-ROR1 expression in PF is associated with lower overall survival (p = 0.0482).

Conclusion

With exo-ROR1 in PF we found a promising diagnostic and prognostic biomarker possibly discriminating between NC, PDAC (PER-) and PDAC (PER+) and might shed light on future diagnostic and therapeutic concepts in PDAC.

How receptor tyrosine kinase-like orphan receptor 1 meets its partners in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common leukemia in western societies, recognized by clinical and molecular heterogeneity. Despite the success of targeted therapies, acquired resistance remains a challenge for relapsed and refractory CLL, as a consequence of mutations in the target or the upregulation of other survival pathways leading to the progression of the disease. Research on proteins that can trigger such pathways may define novel therapies for a successful outcome in CLL such as the receptor tyrosine kinase-like orphan receptor 1 (ROR1). ROR1 is a signaling receptor for Wnt5a, with an important role during embryogenesis. The aberrant expression on CLL cells and several types of tumors, is involved in cell proliferation, survival, migration as well as drug resistance. Antibody-based immunotherapies and small-molecule compounds emerged to target ROR1 in preclinical and clinical studies. Efforts have been made to identify new prognostic markers having predictive value to refine and increase the detection and management of CLL. ROR1 can be considered as an attractive target for CLL diagnosis, prognosis, and treatment. It can be clinically effective alone and/or in combination with current approved agents. In this review, we summarize the scientific achievements in targeting ROR1 for CLL diagnosis, prognosis, and treatment.

Defining the Role of Metastasis-Initiating Cells in Promoting Carcinogenesis in Ovarian Cancer

Ovarian cancer is the deadliest gynecological malignancy with a high prevalence of transcoelomic metastasis. Metastasis is a multi-step process and only a small percentage of cancer cells, metastasis-initiating cells (MICs), have the capacity to finally establish metastatic lesions. These MICs maintain a certain level of stemness that allows them to differentiate into other cell types with distinct transcriptomic profiles and swiftly adapt to external stresses. Furthermore, they can coordinate with the microenvironment, through reciprocal interactions, to invade and establish metastases. Therefore, identifying, characterizing, and targeting MICs is a promising strategy to counter the spread of ovarian cancer. In this review, we provided an overview of OC MICs in the context of characterization, identification through cell surface markers, and their interactions with the metastatic niche to promote metastatic colonization.

CAR-T cell therapy for hematological malignancies: History, status and promise

For many years, the methods of cancer treatment are usually surgery, chemotherapy and radiation therapy. Although these methods help to improve the condition, most tumors still have a poor prognosis. In recent years, immunotherapy has great potential in tumor treatment. Chimeric antigen receptor T-cell immunotherapy (CAR-T) uses the patient's own T cells to express chimeric antigen receptors. Chimeric antigen receptor (CAR) recognizes tumor-associated antigens and kills tumor cells. CAR-T has achieved good results in the treatment of hematological tumors. In 2017, the FDA approved the first CAR-T for the treatment of B-cell acute lymphoblastic leukemia (ALL). In October of the same year, the FDA approved CAR-T to treat B-cell lymphoma. In order to improve and enhance the therapeutic effect, CAR-T has become a research focus in recent years. The structure of CAR, the targets of CAR-T treatment, adverse reactions and improvement measures during the treatment process are summarized. This review is an attempt to highlight recent and possibly forgotten findings of advances in chimeric antigen receptor T cell for treatment of hematological tumors.

Evaluation of the prognostic significance of receptor tyrosine kinase-like orphan receptor 1 (ROR1) in lung carcinoma and its relation to lymphangiogenesis and epithelial mesenchymal transition

Exploring the carcinogenic mechanisms of lung carcinoma helps to discover novel prognostic biomarkers and develop new therapeutic options to improve patient's survival. Receptor Tyrosine Kinase-Like Orphan Receptor 1 (ROR1), a transmembrane protein, contributes to cancer progression and metastasis; via stimulation of epithelial mesenchymal transition (EMT) and promotion of angiogenesis. This makes ROR1 an important target for tumor therapy. This study aimed to evaluate expression of ROR1, E-cadherin (a marker of EMT), and D2-40 (a marker of lymphangiogenesis) in lung carcinoma and associate their expressions with the available clinicopathological parameters and patients' survival. Immunohistochemical staining using ROR1, E-cadherin, and D2-40 was performed for 78 cases of lung carcinoma. Kaplan-Meier survival curves and Cox-regression analysis were done. High ROR1 expression was detected in 46.2% of cases. Significant relations were found between high ROR1 expression and larger tumor size (P < 0.001), poorly differentiated tumors (P = 0.001), advanced tumor stages (P < 0.001), positive lymph nodal status (P < 0.001), decreased E-cadherin expression (P < 0.001), and high lymphovascular density (LVD) (P < 0.001). Patients' progression free survival (PFS) and overall survival (OS) were shorter with high ROR1 expression. High ROR1 expression, high LVD, large tumor size, and adenocarcinoma histopathological type were independent risk factors for OS in lung carcinoma patients. High ROR1 expression is associated with poor prognostic parameters in lung carcinoma patients including higher grade, advanced stages, high LVD, epithelial mesenchymal transition, as well as decreased PFS and OS.

ROR1-STAT3 signaling contributes to ovarian cancer intra-tumor heterogeneity

Wnt pathway dysregulation through genetic and non-genetic alterations occurs in multiple cancers, including ovarian cancer (OC). The aberrant expression of the non-canonical Wnt signaling receptor ROR1 is thought to contribute to OC progression and drug resistance. However, the key molecular events mediated by ROR1 that are involved in OC tumorigenesis are not fully understood. Here, we show that ROR1 expression is enhanced by neoadjuvant chemotherapy, and Wnt5a binding to ROR1 can induce oncogenic signaling via AKT/ERK/STAT3 activation in OC cells. Proteomics analysis of isogenic ROR1-knockdown OC cells identified STAT3 as a downstream effector of ROR1 signaling. Transcriptomics analysis of clinical samples (n = 125) revealed that ROR1 and STAT3 are expressed at higher levels in stromal cells than in epithelial cancer cells of OC tumors, and these findings were corroborated by multiplex immunohistochemistry (mIHC) analysis of an independent OC cohort (n = 11). Our results show that ROR1 and its downstream STAT3 are co-expressed in epithelial as well as stromal cells of OC tumors, including cancer-associated fibroblasts or CAFs. Our data provides the framework to expand the clinical utility of ROR1 as a therapeutic target to overcome OC progression.

Advances in chimeric antigen receptor T cells therapy in the treatment of breast cancer

Breast cancer (BC) is the most frequently occurring cancer type seriously threatening the lives of women worldwide. Clinically, the high frequency of diverse resistance to current therapeutic strategies advocates a demand to develop novel and effective approaches for the efficient treatment of BC. The chimeric antigen receptor T (CAR-T) cells therapy, one of the immunotherapies, has displayed powerful capacity to specifically kill and eliminate tumors. Due to the success of CAR-T therapy achieved in treating hematological malignancy, the effect of CAR-T cells therapy has been tested in various human diseases including breast cancer. This review summarized and discussed the landscape of the CAR-T therapy for breast cancer, including the advances, challenge and countermeasure of CAR-T therapy in research and clinical application. The roles of potential antigen targets, tumor microenvironment, immune escape in regulating CAR-T therapy, the combination of CAR-T therapy with other therapeutic strategies to further enhance therapeutic efficacy of CAR-T treatment were also highlighted. Therefore, our review provided a comprehensive understanding of CAR-T cell therapy in breast cancer which will awake huge interests for future in-depth investigation of CAR-T based therapy in cancer treatment.

Multi-targeted immunotherapeutics to treat B cell malignancies

The concept of multi-targeted immunotherapeutic systems has propelled the field of cancer immunotherapy into an exciting new era. Multi-effector molecules can be designed to engage with, and alter, the patient's immune system in a plethora of ways. The outcomes can vary from effector cell recruitment and activation upon recognition of a cancer cell, to a multipronged immune checkpoint blockade strategy disallowing evasion of the cancer cells by immune cells, or to direct cancer cell death upon engaging multiple cell surface receptors simultaneously. Here, we review the field of multi-specific immunotherapeutics implemented to treat B cell malignancies. The mechanistically diverse strategies are outlined and discussed; common B cell receptor antigen targeting strategies are outlined and summarized; and the challenges of the field are presented along with optimistic insights for the future.

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.

A Small Molecule Targeting the Intracellular Tyrosine Kinase Domain of ROR1 (KAN0441571C) Induced Significant Apoptosis of Non-Small Cell Lung Cancer (NSCLC) Cells

The ROR1 receptor tyrosine kinase is expressed in embryonic tissues but is absent in normal adult tissues. ROR1 is of importance in oncogenesis and is overexpressed in several cancers, such as NSCLC. In this study, we evaluated ROR1 expression in NSCLC patients (N = 287) and the cytotoxic effects of a small molecule ROR1 inhibitor (KAN0441571C) in NSCLC cell lines. ROR1 expression in tumor cells was more frequent in non-squamous (87%) than in squamous (57%) carcinomas patients, while 21% of neuroendocrine tumors expressed ROR1 (p = 0.0001). A significantly higher proportion of p53 negative patients in the ROR1+ group than in the p53 positive non-squamous NSCLC patients (p = 0.03) was noted. KAN0441571C dephosphorylated ROR1 and induced apoptosis (Annexin V/PI) in a time- and dose-dependent manner in five ROR1+ NSCLC cell lines and was superior compared to erlotinib (EGFR inhibitor). Apoptosis was confirmed by the downregulation of MCL-1 and BCL-2, as well as PARP and caspase 3 cleavage. The non-canonical Wnt pathway was involved. The combination of KAN0441571C and erlotinib showed a synergistic apoptotic effect. KAN0441571C also inhibited proliferative (cell cycle analyses, colony formation assay) and migratory (scratch wound healing assay) functions. Targeting NSCLC cells by a combination of ROR1 and EGFR inhibitors may represent a novel promising approach for the treatment of NSCLC patients.

Investigating the inhibitory and penetrating properties of three novel anticancer and antimicrobial scorpion peptides via molecular docking and molecular dynamic simulation

The two types of bladder cancer, muscle invasive and non-muscle invasive (NMIBC), are among the most prevalent cancers worldwide. Despite this, even though muscle-invasive bladder cancer is more deadly, NMIBC requires more therapy due to a greater recurrence rate and more extended and expensive care. Immunotherapy, intravesical chemotherapy, cystoscopy, and transurethral resection (TUR) are among the treatments available. Crude scorpion venomand purified proteins and peptides, can suppress cancer metastasis in an in vitro or in vivo context, suppress cancer growth, halt the cell cycle, and cause cell apoptosis, according to an increasing number of experimental and preclinical studies. In this research, three novels discovered peptides (P2, P3 and P4. ProteomeXchange: PXD036231) from Buthotus saulcyi and, Odontobuthus doriae scorpions were used along with a peptide called pantinin (as a control). The phylogenetic tree showed that the peptides belong to Chaperonin HSP60, Chrysophsin2 and Pheromone-binding protein2, respectively. These peptides were docked with four known antigens, BAGE, BLCAP, PRAME and ROR1 related to bladder cancer and three bacterial antigens FliC, FliD and FimH to investigate their antimicrobial and anticancer properties. The results showed that peptides 2 and 3 have the best binding rate. The MD simulation results also confirmed the binding of peptides 2 and 3 to antigens. The penetration power of peptides 2 and 3 in the membrane of cancer cells and bacterial cells was also simulated, and the results of RMSD and PD confirmed it. QSAR suggests that peptides 2 and 3 can act as anti-cancer and anti-microbial peptides.Communicated by Ramaswamy H. Sarma.

Anti-ROR1 CAR-T cells: Architecture and performance

The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a membrane receptor that plays a key role in development. It is highly expressed during the embryonic stage and relatively low in some normal adult tissues. Malignancies such as leukemia, lymphoma, and some solid tumors overexpress ROR1, making it a promising target for cancer treatment. Moreover, immunotherapy with autologous T-cells engineered to express a ROR1-specific chimeric antigen receptor (ROR1 CAR-T cells) has emerged as a personalized therapeutic option for patients with tumor recurrence after conventional treatments. However, tumor cell heterogeneity and tumor microenvironment (TME) hinder successful clinical outcomes. This review briefly describes the biological functions of ROR1 and its relevance as a tumor therapeutic target, as well as the architecture, activity, evaluation, and safety of some ROR1 CAR-T cells used in basic research and clinical trials. Finally, the feasibility of applying the ROR1 CAR-T cell strategy in combination with therapies targeting other tumor antigens or with inhibitors that prevent tumor antigenic escape is also discussed.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT02706392.

Meta-Analysis of Survival Effects of Receptor Tyrosine Kinase-like Orphan Receptor 1 (ROR1)

Background and Objectives: Identification and targeting of membrane proteins in tumor cells is one of the key steps in the development of cancer drugs. The receptor tyrosine kinase-like orphan receptor (ROR) type 1 is a type-I transmembrane protein expressed in various cancer tissues, which is in contrast to its limited expression in normal tissues. These characteristics make ROR1 a candidate target for cancer treatment. This study aimed to identify the prognostic value of ROR1 expression in cancers. Materials and Methods: We conducted a comprehensive systematic search of electronic databases (PubMed) from their inception to September 2021. The included studies assessed the effect of ROR1 on overall survival (OS) and progression-free survival (PFS). Hazard ratios (HR) from collected data were pooled in a meta-analysis using Revman version 5.4 with generic inverse-variance and random effects modeling. Results: A total of fourteen studies were included in the final analysis. ROR1 was associated with worse OS (HR 1.95, 95% confidence interval (CI) 1.50−2.54; p < 0.001) with heterogeneity. The association between poor OS and ROR1 expression was high in endometrial cancer, followed by ovarian cancer, and diffuse large B cell lymphoma. In addition, ROR1 was associated with poor PFS (HR 1.84, 95% CI 1.60−2.10; p < 0.001), but heterogeneity was not statistically significant. In subgroup analysis, high ROR1 expression showed a significantly higher rate of advanced stage or lymph node metastasis. Conclusions: This meta-analysis provides evidence that ROR1 expression is associated with adverse outcome in cancer survival. This result highlights ROR1 as a target for developmental therapeutics in cancers.

Pan-Tissue and -Cancer Analysis of ROR1 and ROR2 Transcript Variants Identify Novel Functional Significance for an Alternative Splice Variant of ROR1

ROR1/2 are putative druggable targets increasing in significance in translational oncology. Expression of ROR1/2 mRNA and transcript variants has not been systematically examined thus far. ROR1/2 transcript variant sequences, signal peptides for cell surface localisation, and mRNA and transcript variant expression were examined in 34 transcriptomic datasets including 33 cancer types and 54 non-diseased human tissues. ROR1/2 have four and eight transcript variants, respectively. ROR1/2 mRNA and transcript variant expression was detected in various non-diseased tissues. Our analysis identifies predominant expression of ROR1 transcript variant ENST00000545203, which lacks a signal peptide for cell surface localisation, rather than the predicted principal variant ENST00000371079. ENST00000375708 is the predominantly expressed transcript variant of ROR2. ROR1/2 expression in healthy human tissues should be carefully considered for safety assessment of targeted therapy. Studies exploring the function and significance of the predominantly expressed ROR1 transcript variant ENST00000545203 are warranted.

Multiomics characterization implicates PTK7 in ovarian cancer EMT and cell plasticity and offers strategies for therapeutic intervention

Most patients with ovarian cancer (OC) are diagnosed at a late stage when there are very few therapeutic options and a poor prognosis. This is due to the lack of clearly defined underlying mechanisms or an oncogenic addiction that can be targeted pharmacologically, unlike other types of cancer. Here, we identified protein tyrosine kinase 7 (PTK7) as a potential new therapeutic target in OC following a multiomics approach using genetic and pharmacological interventions. We performed proteomics analyses upon PTK7 knockdown in OC cells and identified novel downstream effectors such as synuclein-γ (SNCG), SALL2, and PP1γ, and these findings were corroborated in ex vivo primary samples using PTK7 monoclonal antibody cofetuzumab. Our phosphoproteomics analyses demonstrated that PTK7 modulates cell adhesion and Rho-GTPase signaling to sustain epithelial-mesenchymal transition (EMT) and cell plasticity, which was confirmed by high-content image analysis of 3D models. Furthermore, using high-throughput drug sensitivity testing (525 drugs) we show that targeting PTK7 exhibited synergistic activity with chemotherapeutic agent paclitaxel, CHK1/2 inhibitor prexasertib, and PLK1 inhibitor GSK461364, among others, in OC cells and ex vivo primary samples. Taken together, our study provides unique insight into the function of PTK7, which helps to define its role in mediating aberrant Wnt signaling in ovarian cancer.

Characterization of Adrenal miRNA-Based Dysregulations in Cushing's Syndrome

MiRNAs are important epigenetic players with tissue- and disease-specific effects. In this study, our aim was to investigate the putative differential expression of miRNAs in adrenal tissues from different forms of Cushing’s syndrome (CS). For this, miRNA-based next-generation sequencing was performed in adrenal tissues taken from patients with ACTH-independent cortisol-producing adrenocortical adenomas (CPA), from patients with ACTH-dependent pituitary Cushing’s disease (CD) after bilateral adrenalectomy, and from control subjects. A confirmatory QPCR was also performed in adrenals from patients with other CS subtypes, such as primary bilateral macronodular hyperplasia and ectopic CS. Sequencing revealed significant differences in the miRNA profiles of CD and CPA. QPCR revealed the upregulated expression of miR-1247-5p in CPA and PBMAH (log2 fold change > 2.5, p < 0.05). MiR-379-5p was found to be upregulated in PBMAH and CD (log2 fold change > 1.8, p < 0.05). Analyses of miR-1247-5p and miR-379-5p expression in the adrenals of mice which had been exposed to short-term ACTH stimulation showed no influence on the adrenal miRNA expression profiles. For miRNA-specific target prediction, RNA-seq data from the adrenals of CPA, PBMAH, and control samples were analyzed with different bioinformatic platforms. The analyses revealed that both miR-1247-5p and miR-379-5p target specific genes in the WNT signaling pathway. In conclusion, this study identified distinct adrenal miRNAs as being associated with CS subtypes.

Development of Human Recombinant Antibodies Against ROR1 Tumor Antigen

BACKGROUND

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncofetal antigen expressed on many types of cancer cells, but not normal adult cells. ROR1 antigen contributes to cancer development and progression by several signaling pathways. ROR1 expression has been associated with tumor growth, survival, and metastasis. In this study specific human recombinant antibodies were selected against ROR1 antigen for their use in cancer immunotherapy.

METHODS

Phage display technology was used to produce phage antibody from a human scFv library. Phage concentration was determined to confirm the phage rescue process. Panning procedure was performed to isolate specific scFv clones against ROR1 epitope. Phage ELISA was done to evaluate the reactivity of the selected scFvs.

RESULTS

Two specific human scFvs with frequencies of 20% and 25% were selected against ROR1 peptide. The antibodies showed specific reaction to the corresponding epitopes in phage ELISA.

DISCUSSION

Cancer targeted therapy using human specific antibodies is a new strategy, which is used in cancer therapy. The selected specific scFvs that target ROR1 epitope are human antibodies that originated from a human library and have the potential to be used in clinic in cancer immunotherapy of ROR1 positive tumors without induction of human anti mouse antibody (HAMA) response.

Identification of a 12-Gene Signature and Hub Genes Involved in Kidney Wilms Tumor via Integrated Bioinformatics Analysis

Wilms tumor (WT), also known as nephroblastoma, is a rare primary malignancy in all kinds of tumor. With the development of second-generation sequencing, the discovery of new tumor markers and potential therapeutic targets has become easier. This study aimed to explore new WT prognostic biomarkers. In this study, WT-miRNA datasets GSE57370 and GSE73209 were selected for expression profiling to identify differentially expressed genes. The key gene miRNA, namely hsa-miR-30c-5p, was identified by overlapping, and the target gene of candidate hsa-miR-30c-5p was predicted using an online database. Furthermore, 384 genes were obtained by intersecting them with differentially expressed genes in the TARGET-WT database, and the genes were analyzed for pathway and functional enrichment. Kaplan–Meier survival analysis of the 384 genes yielded a total of 25 key genes associated with WT prognosis. Subsequently, a prediction model with 12 gene signatures (BCL6, CCNA1, CTHRC1, DGKD, EPB41L4B, ERRFI1, LRRC40, NCEH1, NEBL, PDSS1, ROR1, and RTKN2) was developed. The model had good predictive power for the WT prognosis at 1, 3, and 5 years (AUC: 0.684, 0.762, and 0.774). Finally, ERRFI1 (hazard ratios [HR] = 1.858, 95% confidence intervals [CI]: 1.298–2.660) and ROR1 (HR = 0.780, 95% CI: 0.609–0.998) were obtained as independent predictors of prognosis in WT patients by single, multifactorial Cox analysis.

Stress Hormones: Emerging Targets in Gynecological Cancers

In the past decade, several discoveries have documented the existence of innervation in ovarian cancer and cervical cancer. Notably, various neurotransmitters released by the activation of the sympathetic nervous system can promote the proliferation and metastasis of tumor cells and regulate immune cells in the tumor microenvironment. Therefore, a better understanding of the mechanisms involving neurotransmitters in the occurrence and development of gynecological cancers will be beneficial for exploring the feasibility of using inexpensive β-blockers and dopamine agonists in the clinical treatment of gynecological cancers. Additionally, this article provides some new insights into targeting tumor innervation and neurotransmitters in the tumor microenvironment.

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.

The emerging role of Wnt5a in the promotion of a pro-inflammatory and immunosuppressive tumor microenvironment

Wnt5a is the prototypical activator of the non-canonical Wnt pathways, and its overexpression has been implicated in the progression of several tumor types by promoting cell motility, invasion, EMT, and metastasis. Recent evidences have revealed a novel role of Wnt5a in the phosphorylation of the NF-κB subunit p65 and the activation of the NF-κB pathway in cancer cells. In this article, we review the molecular mechanisms and mediators defining a Wnt5a/NF-κB signaling pathway and propose that the aberrant expression of Wnt5a in some tumors drives a Wnt5a/NF-κB/IL-6/STAT3 positive feedback loop that amplifies the effects of Wnt5a. The evidences discussed here suggest that Wnt5a has a double effect on the tumor microenvironment. First, it activates an autocrine ROR1/Akt/p65 pathway that promotes inflammation and chemotaxis of immune cells. Then, Wnt5a activates a TLR/MyD88/p50 pathway exclusively in myelomonocytic cells promoting the synthesis of the anti-inflammatory cytokine IL-10 and a tolerogenic phenotype. As a result of these mechanisms, Wnt5a plays a negative role on immune cell function that contributes to an immunosuppressive tumor microenvironment and would contribute to resistance to immunotherapy. Finally, we summarized the development of different strategies targeting either Wnt5a or the Wnt5a receptor ROR1 that can be helpful for cancer therapy by contributing to generate a more immunostimulatory tumor microenvironment.

Caveola-forming proteins and prostate cancer

Caveolae are specialised and dynamic plasma membrane subdomains, involved in many cellular functions including endocytosis, signal transduction, mechanosensing and lipid storage, trafficking, and metabolism. Two protein families are indispensable for caveola formation and function, namely caveolins and cavins. Mutations of genes encoding these caveolar proteins cause serious pathological conditions such as cardiomyopathies, skeletal muscle diseases, and lipodystrophies. Deregulation of caveola-forming protein expression is associated with many types of cancers including prostate cancer. The distinct function of secretion of the prostatic fluid, and the unique metabolic phenotype of prostate cells relying on lipid metabolism as a main bioenergetic pathway further suggest a significant role of caveolae and caveolar proteins in prostate malignancy. Accumulating in vitro, in vivo, and clinical evidence showed the association of caveolin-1 with prostate cancer grade, stage, metastasis, and drug resistance. In contrast, cavin-1 was found to exhibit tumour suppressive roles. Studies on prostate cancer were the first to show the distinct function of the caveolar proteins depending on their localisation within the caveolar compartment or as cytoplasmic or secreted proteins. In this review, we summarise the roles of caveola-forming proteins in prostate cancer and the potential of exploiting them as therapeutic targets or biological markers.

The WNT/ROR Pathway in Cancer: From Signaling to Therapeutic Intervention

The WNT pathway is one of the major signaling cascades frequently deregulated in human cancer. While research had initially focused on signal transduction centered on β-catenin as a key effector activating a pro-tumorigenic transcriptional response, nowadays it is known that WNT ligands can also induce a multitude of β-catenin-independent cellular pathways. Traditionally, these comprise WNT/planar cell polarity (PCP) and WNT/Ca²⁺ signaling. In addition, signaling via the receptor tyrosine kinase-like orphan receptors (RORs) has gained increasing attention in cancer research due to their overexpression in a multitude of tumor entities. Active WNT/ROR signaling has been linked to processes driving tumor development and progression, such as cell proliferation, survival, invasion, or therapy resistance. In adult tissue, the RORs are largely absent, which has spiked the interest in them for targeted cancer therapy. Promising results in preclinical and initial clinical studies are beginning to unravel the great potential of such treatment approaches. In this review, we summarize seminal findings on the structure and expression of the RORs in cancer, their downstream signaling, and its output in regard to tumor cell function. Furthermore, we present the current clinical anti-ROR treatment strategies and discuss the state-of-the-art, as well as the challenges of the different approaches.

Ovarian Cancer Stem Cells: Characterization and Role in Tumorigenesis

Ovarian cancer is a heterogenous disease with variable clinicopathological and molecular mechanisms being responsible for tumorigenesis. Despite substantial technological improvement, lack of early diagnosis contributes to its highest mortality. Ovarian cancer is considered to be the most lethal female gynaecological cancer across the world. Conventional treatment modules with platinum- and Taxane-based chemotherapy can cause an initial satisfactory improvement in ovarian cancer patients. However, approximately 75-80% patients of advanced stage ovarian cancer, experience relapse and nearly 40% have overall poor survival rate. It has been observed that a subpopulation of cells referred as cancer stem cells (CSCs), having self renewal property, escape the conventional chemotherapy because of their quiescent nature. Later, these CSCs following its interaction with microenvironment and release of various inflammatory cytokines, chemokines and matrix metalloproteinases, induce invasion and propagation to distant organs of the body mainly peritoneal cavity. These CSCs can be enriched by their specific surface markers such as CD44, CD117, CD133 and intracellular enzyme such as aldehyde dehydrogenase. This tumorigenicity is further aggravated by the epithelial to mesenchymal transition of CSCs and neovascularisation via epigenetic reprogramming and over-expression of various signalling cascades such as Wnt/β-catenin, NOTCH, Hedgehog, etc. to name a few. Hence, a comprehensive understanding of various cellular events involving interaction between cancer cells and cancer stem cells as well as its surrounding micro environmental components would be of unmet need to achieve the ultimate goal of better management of ovarian cancer patients. This chapter deals with the impact of ovarian cancer stem cells in tumorigenesis which would help in the implementation of basic research into the clinical field in the form of translational research in order to reduce the morbidity and mortality in ovarian cancer patients through amelioration of diagnosis and impoverishment of therapeutic resistance.

The involvement of noncanonical Wnt signaling in cancers

Wnt signaling is one of the key cascades regulating normal tissue development and has been tightly associated with cancer. The Wnt signaling can be subdivided into two categories: canonical & noncanonical. Noncanonical Wnt signaling pathways mainly include Wnt/PCP (planar cell polarity) signaling and Wnt-cGMP (cyclic guanosine monophosphate) /Ca2+ signaling. It has been well studied by previous researches that noncanonical Wnt signaling regulates multiple cell functions including proliferation, differentiation, adhesion, polarity, motility, and migration. The aberrant activation or inhibition of noncanonical Wnt signaling is crucial in cancer progression, exerting both oncogenic and tumor-suppressive effects. Recent studies show the involvement of noncanonical Wnt in regulating cancer cell invasion, metastasis, metabolism, and inflammation. Here, we review current insights into novel components of non-canonical signalings and describe their involvement in various cancer types. We also summarize recent biological and clinical discoveries that outline non-canonical Wnt signaling in tumorigenesis. Finally, we provide an overview of current strategies to target non-canonical Wnt signaling in cancer and challenges that are associated with such approaches.

Functional and clinical significance of ROR1 in lung adenocarcinoma

Background

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is normally detectable in embryonic tissues and absent in adult tissues. ROR1 was shown to inhibit apoptosis, potentiate EGFR signaling and reported to be overexpressed and associated with poor prognosis in several tumor models. This study aimed to assess the expression of ROR1 in lung adenocarcinoma (AC) patients.

Methods

We analyzed ROR1 expression by quantitative real-time PCR (qRT-PCR) in 56 histologically confirmed lung AC, stage I to IV, in addition we evaluated its association with TTF-1 (thyroid transcription factor-1) expression and the main molecular alterations involved in lung cancerogenesis.

Results

ROR1 overexpression was observed in 28.6% of the entire cohort, using a cut-off of 1, or in 51.8% of the cases using the median value as threshold. Among patients without any genetic alteration, ROR1 overexpression was observed in 34.8% considering a cut-off of 1 and 52.2% considering the median value. The distribution of ROR1 was homogeneous among the different molecular categories: we found no association of ROR1 expression and the presence of gene mutations/rearrangements or the expression of TTF-1.

Conclusions

ROR1 overexpression could constitute a potential therapeutic target because altered in a consistent number of lung AC, especially in cases without druggable genetic alterations. ROR1 expression is independent of classical lung cancer molecular alterations and not correlated, in a Caucasian cohort, to TTF-1 expression.

Glucocorticoids induce differentiation and chemoresistance in ovarian cancer by promoting ROR1-mediated stemness

Glucocorticoids are routinely used in the clinic as anti-inflammatory and immunosuppressive agents as well as adjuvants during cancer treatment to mitigate the undesirable side effects of chemotherapy. However, recent studies have indicated that glucocorticoids may negatively impact the efficacy of chemotherapy by promoting tumor cell survival, heterogeneity, and metastasis. Here, we show that dexamethasone induces upregulation of ROR1 expression in ovarian cancer (OC), including platinum-resistant OC. Increased ROR1 expression resulted in elevated RhoA, YAP/TAZ, and BMI-1 levels in a panel of OC cell lines as well as primary ovarian cancer patient-derived cells, underlining the translational relevance of our studies. Importantly, dexamethasone induced differentiation of OC patient-derived cells ex vivo according to their molecular subtype and the phenotypic expression of cell differentiation markers. High-throughput drug testing with 528 emerging and clinical oncology compounds of OC cell lines and patient-derived cells revealed that dexamethasone treatment increased the sensitivity to several AKT/PI3K targeted kinase inhibitors, while significantly decreasing the efficacy of chemotherapeutics such as taxanes, as well as anti-apoptotic compounds such as SMAC mimetics. On the other hand, targeting ROR1 expression increased the efficacy of taxane drugs and SMAC mimetics, suggesting new combinatorial targeted treatments for patients with OC.

Ectopic expression of ROR1 prevents cochlear hair cell loss in guinea pigs with noise-induced hearing loss

Noise-induced hearing loss (NIHL) is one of the most frequent disabilities in industrialized countries. Evidence shows that hair cell loss in the auditory end organ is responsible for the majority of various ear pathological conditions. The functional roles of the receptor tyrosine kinase ROR1 have been underscored in various tumours. In this study, we evaluated the ability of ROR1 to influence cochlear hair cell loss of guinea pigs with NIHL. The NIHL model was developed in guinea pigs, with subsequent measurement of the auditory brainstem response (ABR). Gain-of-function experiments were employed to explore the role of ROR1 in NIHL. The interaction between ROR1 and Wnt5a and their functions in the cochlear hair cell loss were further analysed in response to alteration of ROR1 and Wnt5a. Guinea pigs with NIHL demonstrated elevated ABR threshold and down-regulated ROR1, Wnt5a and NF-κB p65. The up-regulation of ROR1 was shown to decrease the cochlear hair cell loss and the expression of pro-apoptotic gene (Bax, p53) in guinea pig cochlea, but promoted the expression of anti-apoptotic gene (Bcl-2) and the fluorescence intensity of cleaved-caspase-3. ROR1 interacted with Wnt5a to activate the NF-κB signalling pathway through inducing phosphorylation and translocation of p65. Furthermore, Wnt5a overexpression decreased the cochlear hair cell loss. Collectively, this study suggested the protection of overexpression of ROR1 against cochlear hair cell loss in guinea pigs with NIHL via the Wnt5a-dependent NF-κB signalling pathway.

Monoclonal Antibody Against ROR1 Induces Apoptosis in Human Bladder Carcinoma Cells

BACKGROUND

Receptor tyrosine kinase-like Orphan Receptor 1 (ROR1) is one of the promising cell surface antigens for targeting cancer cells. The aim of this study was to evaluate ROR1 cell surface expression in bladder cancer cells using a murine anti-ROR1 monoclonal antibody (mAb) called 5F1-B10 as well as investigate its potential in apoptosis induction.

METHODS

Expression of ROR1 in two human bladder cell lines, 5637 and EJ138, as well as a non-cancerous human cell line, Human Fetal Foreskin Fibroblast (HFFF), was examined by flow cytometry and immunocytochemistry. Immunohistochemical staining of cancer and normal bladder tissues was also performed.

RESULTS

The flow cytometry results showed that 5F1-B10 mAb could recognize ROR1 molecules in 86.1% and 45.6% of 5637 and EJ138 cells, respectively. The expression level of ROR1 was 5.49% in HFFF cells. The immunocytochemistry and immunohistochemistry staining results also confirmed the presence of ROR1 on the surface of both bladder cancer cells and tissues, respectively. The obtained data from apoptosis assay demonstrated that 5F1-B10 mAb could induce apoptosis in both 5637 and EJ138 cell lines.

CONCLUSION

Taken together, our finding indicates the role of ROR1 in bladder cancer cell survival and suggests this receptor might be a promising target for developing novel therapeutic agents against bladder carcinoma.

Analyzing the factors that influence occult metastasis in oral tongue cancer

Objectives

We accessed the various clinico-histopathological factors, and their association with occult metastasis (OM) in oral tongue squamous cell carcinoma (OTSCC).

Materials and Methods

One hundred-nine patients with OTSCC were divided into the elective neck dissection (END) group and the watchful waiting (WW) group. Age, sex, T-stage, depth of invasion and differentiation were evaluated to determine the correlation between clinico-histopathological factors and OM. For immunohistochemical analysis, paraffin-embedded blocks of 41 OTSCC specimens were examined with antibodies (VEGF-c, c-Met, and ROR1).

Results

The group with tumor thickness of oral tongue cancer ≥3 mm had higher incidence of OM than those with a thickness of <3 mm. The depth of invasion was statistically correlated with OM (P=0.022). Immunohistochemical analysis showed that high expression of VEGF-c (P=0.043), c-Met (P=0.009), and ROR-1 (P=0.003) were statistically correlated with OM.

Conclusion

The analysis of these clinico-histopathological and immunohistochemical factors can help to determine neck dissection in clinically negative (cN0) patients.

Two cancer stem cell-targeted therapies in clinical trials as viewed from the standpoint of the cancer stem cell model

A key implication of the cancer stem cell model is that for a cancer therapy to be curative, it is imperative to eliminate the cancer stem cells (CSCs) that drive tumor progression. The California Institute for Regenerative Medicine is supporting two novel approaches that target CSCs, one an antibody‐mediated immunotherapy targeting CD47 and the other an antibody targeting ROR1. This article summarizes the evidence that CSCs are targeted and discusses the results of early clinical trials within the context of the CSC model.

Progesterone receptor inhibits the proliferation and invasion of endometrial cancer cells by up regulating Krüppel-like factor 9

Background

Krüppel-like factor 9 (KLF9) is one of the most important members of the KLF family, and is abnormally expressed in many tumors. However, the detailed function of KLF9 in endometrial cancer (EC) was barely investigated.

Methods

In this study, a total of 52 paired EC tissues were recruited to detect the KLF9 expression. Then a serial of phenotypic experiments and mechanism researches were performed.

Results

The results showed that KLF9 expression was decreased in EC tissues, and the reduced expression of KLF9 is associated with highly metastatic capacity of EC cells. KLF9 could inhibit the proliferation and invasion of EC cells by inhibiting the Wnt/β-catenin signaling pathway. Progesterone receptor (PR) could bind to KLF9 promoter and a positive correlation between KLF9 and PR expression was witnessed.

Conclusions

Taken together, the reduction of KLF9 induced by PR might participate in the development of EC and targeting KLF9 may provide a novel strategy for EC management.

WNT signaling inducing activity in ascites predicts poor outcome in ovarian cancer

High grade serous carcinoma of the ovary, fallopian tube, and peritoneum (HGSC) is the deadliest gynecological disease which results in a five-year survival rate of 30% or less. HGSC is characterized by the early and rapid development of metastases accompanied by a high frequency of ascites i.e. the pathological accumulation of fluid in peritoneum. Ascites constitute a complex tumor microenvironment and contribute to disease progression by largely unknown mechanisms. Methods: Malignant ascites obtained from HGSC patients who had undergone cytoreductive surgery were tested for their ability to induce WNT signaling in the Kuramochi cell line, a novel and clinically relevant in vitro model of HGSC. Next, cancer spheroids (the main form of metastatic cancer cells in ascites) were evaluated with respect to WNT signaling. Kuramochi cells were used to determine the role of individual WNT signaling branches in the adoption of metastatic stem cell-like behavior by HGSC cells. Furthermore, we analyzed genomic and transcriptomic data on WNT/Planar Cell Polarity (PCP) components retrieved from public cancer databases and corroborated with primary patient samples and validated antibodies on the protein level. Results: We have shown that ascites are capable of inducing WNT signaling in primary HGSC cells and HGSC cell line, Kuramochi. Importantly, patients whose ascites cannot activate WNT pathway present with less aggressive disease and a considerably better outcome including overall survival (OS). Functionally, the activation of non-canonical WNT/PCP signaling by WNT5A (and not canonical WNT/β-catenin signaling by WNT3A) promoted the metastatic stem-cell (metSC) like behavior (i.e. self-renewal, migration, and invasion) of HGSC cells. The pharmacological inhibition of casein kinase 1 (CK1) as well as genetic ablation (dishevelled 3 knock out) of the pathway blocked the WNT5A-induced effect. Additionally, WNT/PCP pathway components were differentially expressed between healthy and tumor tissue as well as between the primary tumor and metastases. Additionally, ascites which activated WNT/PCP signaling contained the typical WNT/PCP ligand WNT5A and interestingly, patients with high levels of WNT5A protein in their ascites exhibited poor progression-free survival (PFS) and OS in comparison to patients with low or undetectable ascitic WNT5A. Together, our results suggest the existence of a positive feedback loop between tumor cells producing WNT ligands and ascites that distribute WNT activity to cancer cells in the peritoneum, in order to promote their pro-metastatic features and drive HGSC progression. Conclusions: Our results highlight the role of WNT/PCP signaling in ovarian cancerogenesis, indicate a possible therapeutic potential of CK1 inhibitors for HGSC, and strongly suggest that the detection of WNT pathway inducing activity ascites (or WNT5A levels in ascites as a surrogate marker) could be a novel prognostic tool for HGSC patients.

ROR2 induces cell apoptosis via activating IRE1α/JNK/CHOP pathway in high-grade serous ovarian carcinoma in vitro and in vivo

Background

Epithelial ovarian cancer (EOC) is the most lethal cancer in female genital tumors. New disease markers and novel therapeutic strategies are urgent to identify considering the current status of treatment. Receptor tyrosine kinases family plays critical roles in embryo development and disease progression. However, ambivalent research conclusions of ROR2 make its role in tumor confused and the underlying mechanism is far from being understood. In this study, we sought to clarify the effects of ROR2 on high-grade serous ovarian carcinoma (HGSOC) cells and reveal the mechanism.

Methods

Immunohistochemistry assay and western-blot assay were used to detect proteins expression. ROR2 overexpression adenovirus and Lentivirus were used to create ROR2 overexpression model in vitro and in vivo, respectively. MTT assay, colony formation assay and transwell assay were used to measure the proliferation, invasion and migration ability of cancer cells. Flow cytometry assay was used to detect cell apoptosis rate. Whole transcriptome analysis was used to explore the differentially expressed genes between ROR2 overexpression group and negative control group. SiRNA targeted IRE1α was used to knockdown IRE1α. Kira6 was used to inhibit phosphorylation of IRE1α.

Results

Expression of ROR2 was significantly lower in HGSOC tissues compared to normal fallopian tube epithelium or ovarian surface epithelium tissues. In HGSOC cohort, patients with advanced stages or positive lymph nodes were prone to express lower ROR2. Overexpression of ROR2 could repress the proliferation of HGSOC cells and induce cell apoptosis. RNA sequencing analysis indicated that ROR2 overexpression could induce unfold protein response. The results were also confirmed by upregulation of BIP and phosphorylated IRE1α. Furthermore, pro-death factors like CHOP, phosphorylated JNK and phosphorylated c-Jun were also upregulated. IRE1α knockdown or Kira6 treatment could reverse the apoptosis induced by ROR2 overexpression. Finally, tumor xenograft experiment showed ROR2 overexpression could significantly repress the growth rate and volume of transplanted tumors.

Conclusions

Taken together, ROR2 downregulation was associated with HGSOC development and progression. ROR2 overexpression could repress cell proliferation and induce cell apoptosis in HGSOC cells. And the underlying mechanism might be the activation of IRE1α/JNK/CHOP pathway induced by ROR2.

A crucial role of fibroblast growth factor 2 in the differentiation of hair follicle stem cells toward endothelial cells in a STAT5-dependent manner

Fibroblast growth factor (FGF2) is reported to affect the proliferation, differentiation, and survival abilities of stem cells. In this study, we hypothesize that FGF2 might promote the differentiation of hair follicle stem cell (HFSCs) into endothelial cells (ECs), in a manner dependent on STAT5 activation. We first treated human HFSCs with recombinant human FGF2 to determine the involvement of FGF2 in the differentiation of HFSCs. Then the expression of EC-specific markers including von Willebrand factor (vWF), VE-cadherin, CD31, FLT-1, KDR and Tie2 was evaluated using immunofluorescence and flow cytometry, while the expression of HFSC-specific markers such as K15, K19, Lgr5, Sox9 and Lhx2 was determined by flow cytometry. Next, in vitro tube formation was performed to confirm the function of FGF2, and low-density lipoprotein (LDL) uptake by ECs and HFSCs was studied by Dil-acetylated LDL assay. In addition, we transduced FGF2-treated HFSCs with constitutive-active or dominant-negative STAT5A adenovirus vectors. FGF2 up-regulated the expression of EC-specific markers, and promoted the differentiation of HFSCs into ECs, tube formation and LDL uptake. The phosphorylated STAT5 was translocated into the nucleus of HFSCs after FGF2 treatment, but this translocation was blocked by the dominant-negative STAT5A mutant. FGF2 increased the differentiation potential through the activation of STAT5 in vivo. Taken together, we find that FGF2 promotes the differentiation of HFSCs into ECs via activated STAT5, which gives a new perspective on the role of FGF2 in the development of ischemic vascular disease.

Wnt5a induces ROR1 to recruit cortactin to promote breast-cancer migration and metastasis

ROR1 is a conserved oncoembryonic surface protein expressed in breast cancer. Here we report that ROR1 associates with cortactin in primary breast-cancer cells or in MCF7 transfected to express ROR1. Wnt5a also induced ROR1-dependent tyrosine phosphorylation of cortactin (Y421), which recruited ARHGEF1 to activate RhoA and promote breast-cancer-cell migration; such effects could be inhibited by cirmtuzumab, a humanized mAb specific for ROR1. Furthermore, treatment of mice bearing breast-cancer xenograft with cirmtuzumab inhibited cortactin phosphorylation in vivo and impaired metastatic development. We established that the proline at 841 of ROR1 was required for it to recruit cortactin and ARHGEF1, activate RhoA, and enhance breast-cancer-cell migration in vitro or development of metastases in vivo. Collectively, these studies demonstrate that the interaction of ROR1 with cortactin plays an important role in breast-cancer-cell migration and metastasis.

MAGE-A1 in lung adenocarcinoma as a promising target of chimeric antigen receptor T cells

BACKGROUND

Cancer/testis antigens (CTAs) are a special type of tumor antigen and are believed to act as potential targets for cancer immunotherapy.

METHODS

In this study, we first screened a rational CTA MAGE-A1 for lung adenocarcinoma (LUAD) and explored the detailed characteristics of MAGE-A1 in LUAD development through a series of phenotypic experiments. Then, we developed a novel MAGE-A1-CAR-T cell (mCART) using lentiviral vector based on our previous MAGE-A1-scFv. The anti-tumor effects of this mCART were finally investigated in vitro and in vivo.

RESULTS

The results showed striking malignant behaviors of MAGE-A1 in LUAD development, which further validated the rationality of MAGE-A1 as an appropriate target for LUAD treatment. Then, the innovative mCART was successfully constructed, and mCART displayed encouraging tumor-inhibitory efficacy in LUAD cells and xenografts.

CONCLUSIONS

Taken together, our data suggest that MAGE-A1 is a promising candidate marker for LUAD therapy and the MAGE-A1-specific CAR-T cell immunotherapy may be an effective strategy for the treatment of MAGE-A1-positive LUAD.

A fully chimeric IgG antibody for ROR1 suppresses ovarian cancer growth in vitro and in vivo

BACKGROUND

Over-expression of Receptor-tyrosine-kinase-like Orphan Receptor 1 (ROR1) in cancer cells has been reported in the context of several tumors (including ovarian cancer) and is associated with poor prognosis. The aim of this study was to construct a fully chimeric anti-ROR1 IgG antibody (ROR1-IgG) and investigate its antitumor activity against ovarian cancer cells, bothin vitro and in vivo.

METHODS

A fully chimeric anti-ROR1 IgG antibody (ROR1-IgG) eukaryotic expression vector was constructed and ROR1-IgG antibody was expressed in CHO cells. The characteristics of ROR1-IgG were investigated by ELISA, SPR, Western blotting, FACS and fluorescence staining analyses. CCK8 and wound healing assays were performed to determine inhibition and migration capacity of ovarian cancer cells after treatment with ROR1-IgGin vitro. Further, the antitumor activity of ROR1-IgG was assessed in vivo using tumor-mice xenograft model.

RESULTS

The results showed that ROR1-IgG could specifically bind to ROR1-positive cells (HO8910 and A2780) with a high affinity. Functional studies revealed that ROR1-IgG inhibited the malignant behavior of ROR1-positive cells (HO8910 and A2780) in a time- and dose-dependent manner. These effects were not observed in ROR1-negative lose386 cells. The tumor inhibition rates following treatment with low, medium, and high concentrations of ROR1-IgG were approximately 47.72%, 53.79%, and 60.51%, respectively. In addition, the expression of Bcl-2 was obviously reduced while that of Bax was distinctly elevated in xenografts.

CONCLUSIONS

Collectively, our findings suggest that ROR1-IgG may be a novel therapeutic agent for patients with ROR1-positive ovarian cancer.

High-Expression HBO1 Predicts Poor Prognosis in Gastric Cancer

OBJECTIVES

Our goal was to assess the expression of histone acetyltransferase binding to origin recognition complex 1 (HBO1) in gastric cancer and the effect on prognosis for the patients.

METHODS

We used quantitative reverse transcription polymerase chain reaction, Western blot, and tissue microarray immunohistochemistry to investigate the expressions of HBO1 messenger RNA (mRNA) and protein in gastric cancer tissues. Online resources, including Oncomine and Kaplan-Meier Plotter, were used to further assess the correlation between HBO1 expression and the prognosis of the patients with gastric cancer.

RESULTS

HBO1 mRNA and protein expressions in gastric cancer tissues were both significantly higher than those in normal tissues. The correlations between high HBO1 expression and differentiation, invasive depth (T), lymph node metastasis (N), distant metastasis (M), TNM staging, and serum carcinoembryonic antigen levels were positive. High HBO1 expression was negatively correlated with survival time in patients with gastric cancer.

CONCLUSIONS

HBO1 might be a valuable biomarker to evaluate the prognosis of patients with gastric cancer.

ROR1 and ROR2-novel targets for neuroblastoma

Background: Despite advances in immunotherapeutic strategies for neuroblastoma (NBL), relapse remains a significant cause of mortality for high risk patients. The discovery of novel tumor associated antigens to improve efficacy and minimize the toxicities of immunotherapy is therefore warranted. Receptor Tyrosine Kinase-like Orphan Receptor-1 and 2 (ROR1 and ROR2) have been found to be expressed in several malignancies with limited expression in healthy tissues. Objectives: Given their role in tumor migration and proliferation and the fact that they were originally cloned from a NBL cell line, we hypothesized that ROR1 and ROR2 could serve as potential targets for anti-ROR1 and anti-ROR2 based immunotherapies in NBL. Methods: We characterized the mRNA and protein expression of ROR1 and ROR2 in NBL cell lines and tissue microarrays of patient samples. To explore the potential of ROR1 targeting, we performed in vitro cytotoxicity assays against NBL using NK92 cells as effector cells. Results: Both ROR1 and ROR2 are expressed across all stages of NBL. In patients with non-MYC amplified tumors, expression of ROR1/ROR2 correlated with survival and prognosis. Moreover, in a proof-of-concept experiment, pretreatment of NBL cell line with anti-ROR1 antibody showed additive cytotoxicity with NK92 cells. Conclusions: ROR1 and ROR2 could serve as novel targets for immunotherapy in NBL. The additive effect of anti-ROR1 antibodies with NK cells needs to be explored further to evaluate the possibility of combining anti-ROR1 antibodies with immune effectors such as NK92 cells as a potential off-the shelf immunotherapy for NBL and other ROR1 expressing malignancies.

Molecular Mechanisms Associated with ROR1-Mediated Drug Resistance: Crosstalk with Hippo-YAP/TAZ and BMI-1 Pathways

Signaling via the Wnt-related receptor tyrosine kinase-like orphan receptor 1 (ROR1) triggers tumorigenic features associated with cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT), while aberrant expression of ROR1 is strongly linked to advanced disease progression and chemoresistance. Several recent studies have shown that Wnt5a binding to ROR1 promotes oncogenic signaling by activating multiple pathways such as RhoA/Rac1 GTPases and PI3K/AKT, which in turn could induce transcriptional coactivator YAP/TAZ or polycomb complex protein BMI-1 signaling, respectively, to sustain stemness, metastasis and ultimately drug-resistance. These data point towards a new feedback loop during cancer development, linking Wnt5a-ROR1 signaling activation to YAP/TAZ or BMI-1 upregulation that could play an important role in disease progression and treatment resistance. This review focuses on the crosstalk between Wnt5a-ROR1 and YAP/TAZ or the BMI-1 signaling network, together with the current advancements in targeted strategies for ROR1-positive cancers.

Identification of a 3-mRNA signature as a novel potential prognostic biomarker in patients with ovarian serous cystadenocarcinoma in G2 and G3

The use of mRNAs as biomarkers serves to diagnose, treat, as well as aid the prognosis of cancer. The present study involved an analysis of mRNAs in the cell cycle at the G2 and G3 tumor grades for the prognosis of ovarian serous cystadenocarcinoma (OSC) using 364 clinical samples (G2:G3=42:322). Statistics aided the identification of NPFFR2, XPNPEP2 and CELA3B; the 3-mRNA model that allows for classification of patients into high- and low-risk groups using a median value of 0.9580745. The rates of survival varied (P=0.00149) and the independent detection of stratification of the risk of this disease was validated with success using the 3-mRNA signature, which was demonstrated to be more successful than the weight model. This approach was revealed to provide the prognosis of grade G2 and G3 in patients with OSC compared with factors used traditionally. Compared with traditional factors, this 3-mRNA model was demonstrated to be the only and independent prognostic factor for patients with G2 and G3 stage OSC. A literature survey was also performed in the present study in order to assess the role of the 3 genes and indirectly prove their effectiveness. The establishment of this new genetic model will enhance prospective prognosis and treatment for patients with OSC.

Presence and role of stem cells in ovarian cancer

Ovarian cancer is the deadliest gynecological malignancy. It is typically diagnosed at advanced stages of the disease, with metastatic sites disseminated widely within the abdominal cavity. Ovarian cancer treatment is challenging due to high disease recurrence and further complicated pursuant to acquired chemoresistance. Cancer stem cell (CSC) theory proposes that both tumor development and progression are driven by undifferentiated stem cells capable of self-renewal and tumor-initiation. The most recent evidence revealed that CSCs in terms of ovarian cancer are not only responsible for primary tumor growth, metastasis and relapse of disease, but also for the development of chemoresistance. As the elimination of this cell population is critical for increasing treatment success, a deeper understanding of ovarian CSCs pathobiology, including epithelial-mesenchymal transition, signaling pathways and tumor microenvironment, is needed. Finally, before introducing new therapeutic agents for ovarian cancer, targeting CSCs, accurate identification of different ovarian stem cell subpopulations, including the very small embryonic-like stem cells suggested as progenitors, is necessary. To these ends, reliable markers of ovarian CSCs should be identified. In this review, we present the current knowledge and a critical discussion concerning ovarian CSCs and their clinical role.

Solution structure, dynamics and function investigation of Kringle domain of human receptor tyrosine kinase-like orphan receptor 1

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) has been recently proposed as a potential target for cancer treatment. It was suggested that monoclonal antibodies (mAb) against the Kringle (KNG) domain of ROR1 could induce apoptosis of chronic lymphocytic leukemia cells. Here, we reported the determination of the solution structure of human ROR1-KNG (hROR1-KNG), investigation of its dynamic properties and potential binding interface by NMR spectroscopy. The obtained NMR structure of hROR1-KNG exhibits an open form at Asn47-His50 and shows obvious differences from other canonical KNGs at the corresponding lysine binding site, which implies that hROR1-KNG may interact with some non-canonical ligands. Dynamics analysis of hROR1-KNG reveal a faster local motion around the α-turn and 3₁₀-helix, which may provide flexibility to protect the proximal hydrophobic core in solution or facilitate the binding of other molecules. The intermediate-to-slow conformational exchange of Cys77-Ile79 may influence the conformation determination of disulfide bond Cys53-Cys77. Binding interface of hROR1-KNG for mAb R11 was analyzed and compared with the epitope for the functional mAbs. Previous study implies that hROR1-KNG may be involved in mediating the heterooligomerization between ROR1 and ROR2 in vivo. However, apparently, no direct interaction between hROR1-KNG and hROR2-KNG was observed from chemical shift perturbation experiment. Our work lays foundation to further functional study on interactions of hROR1-KNG with other biological relevant partners.Communicated by Ramaswamy H. Sarma.

Prognostic value of receptor tyrosine kinase-like orphan receptor (ROR) family in cancer: A meta-analysis

INTRODUCTION

Identification of membrane proteins expressed exclusively on tumor cells is a goal for cancer drug development. The receptor tyrosine kinase-like orphan receptor type 1 and 2 (ROR1/2), are type-I transmembrane proteins expressed in cancer but not in adult normal tissue. Here, we explore the prognostic role ROR1/2 expression on patient outcome.

METHODS

A systematic search of electronic databases identified publications exploring the effect of ROR1/2 on overall survival (OS). Hazard ratios (HR) from collected data were pooled in a meta-analysis using generic inverse-variance and random effects modeling. Subgroup analyses were conducted based on disease site or tumor type.

RESULTS

Twenty five studies met the inclusion criteria. ROR1 was associated with worse overall survival (HR 2.13, 95% confidence interval (CI) 1.62-2.80; P < 0.001) with subgroup analysis showing the strongest association between ROR1 and OS was in lung cancer. There was no significant difference between solid tumors and hematological malignancies (HR 2.15, 95% CI 1.52-3.06 vs. HR 2.02, 95% CI 1.46-2.84; subgroup difference P = 0.80). ROR2 was also associated with worse OS (HR 1.84, 95% CI 1.43-2.38; P < 0.001). There was no significant difference between disease sites although the highest association seen was in head and neck cancers (HR 3.19, 95% CI 1.13-8.97) and the lowest in gynecological cancers (HR 1.19, 95% CI 0.71-2.00; subgroup difference P = 0.10).

CONCLUSIONS

ROR1 and ROR2 expression is associated with adverse outcome in several tumors. ROR1/2 warrants study as a target for developmental therapeutics.

ROR1 associates unfavorable prognosis and promotes lymphoma growth in DLBCL by affecting PI3K/Akt/mTOR signaling pathway

The receptor-tyrosine-kinase (RTK)-like orphan receptor 1 (ROR1) is a transmembrane glycoprotein regarded as a tumor-associated antigen. ROR1 plays an important role in cancer development, but the detailed function of ROR1 in diffuse large B-cell lymphoma (DLBCL) remains unclear. In this study, we first detected ROR1 expression and evaluated the relationship between ROR1 expression and the clinicopathological characteristics of DLBCL patients. Next we employed shRNA-mediated knockdown of ROR1 in DLBCL cell line to explore the characteristics of ROR1 in DLBCL development both in vitro and in vivo. The results showed a significantly higher level of ROR1 in DLBCL tissues than in lymphatic hyperplasia tissues. High ROR1 expression was correlated with unfavorable prognosis in DLBCL patients. Furthermore, ROR1 knockdown inhibited the growth and induced the apoptosis in DLBCL cells and xenografts. In addition, shROR1 inhibited activation of the PI3K/Akt/mTOR signaling pathway, both in vitro and in vivo. Taken together, our results suggest that ROR1 is a novel prognostic marker for DLBCL survival and ROR1 significantly promotes DLBCL tumorigenesis by regulating the PI3K/Akt/mTOR signaling pathway. Targeting ROR1 may provide a promising strategy for DLBCL treatment. © 2019 BioFactors, 45(3):416-426, 2019.