The signaling pathways activated by ROR1 in cancer

Progresses of T-cell-engaging bispecific antibodies in treatment of solid tumors

T-cell-engaging bispecific antibody (TCB) therapies have emerged as a promising immunotherapeutic approach, effectively redirecting effector T cells to selectively eliminate tumor cells. The therapeutic potential of TCBs has been well recognized, particularly with the approval of multiple TCBs in recent years for the treatment of hematologic malignancies as well as some solid tumors. However, TCBs encounter multiple challenges in treating solid tumors, such as on-target off-tumor toxicity, cytokine release syndrome (CRS), and T cell dysfunction within the immunosuppressive tumor microenvironment, all of which may impact their therapeutic efficacy. In this review, we summarize clinical data on TCBs for solid tumor treatment, highlight the challenges faced, and discuss potential solutions based on emerging strategies from current clinical and preclinical research. These solutions include TCB structural optimization, target selection, and combination strategies. This comprehensive analysis aims to guide the development of TCBs from design to clinical application, addressing the evolving landscape of cancer immunotherapy.

Exploring the anticancer mechanism of cardiac glycosides using proteome integral solubility alteration approach

BACKGROUND AND AIMS

Cardiac glycosides (CGs), traditionally used for heart failure, have shown potential as anti-cancer agents. This study aims to explore their multifaceted mechanisms in cancer cell biology using proteome integral solubility alteration (PISA), focusing on the interaction with key proteins implicated in cellular metabolism and mitochondrial function.

METHODS

We conducted lysate-based and intact-cell PISA assays on cancer cells treated with CGs (Digoxin, Digitoxin, Ouabain) to analyze protein solubility changes. This was followed by mass spectrometric analysis and bioinformatics to identify differentially soluble proteins (DSPs). Molecular docking simulations were performed to predict protein-CG interactions. Public data including gene expression changes upon CG treatment were re-analyzed for validation.

RESULTS

The PISA assays revealed CGs' broad-spectrum interactions, particularly affecting proteins like PKM2, ANXA2, SLC16A1, GOT2 and GLUD1. Molecular docking confirmed stable interactions between CGs and these DSPs. Re-analysis of public data supported the impact of CGs on cancer metabolism and cell signaling pathways.

CONCLUSION

Our findings suggest that CGs could be repurposed for cancer therapy by modulating cellular processes. The PISA data provide insights into the polypharmacological effects of CGs, warranting further exploration of their mechanisms and clinical potential.

Novel humanized monoclonal antibodies against ROR1 for cancer therapy

BACKGROUND

Overexpression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) contributes to cancer cell proliferation, survival and migration, playing crucial roles in tumor development. ROR1 has been proposed as a potential therapeutic target for cancer treatment. This study aimed to develop novel humanized ROR1 monoclonal antibodies and investigate their anti-tumor effects.

METHODS

ROR1 expression in tumor tissues and cell lines was analyzed by immunohistochemistry and flow cytometry. Antibodies from mouse hybridomas were humanized by the complementarity-determining region (CDR) grafting technique. Surface plasmon resonance spectroscopy, ELISA assay and flow cytometry were employed to characterize humanized antibodies. In vitro cellular assay and in vivo mouse experiment were conducted to comprehensively evaluate anti-tumor activity of these antibodies.

RESULTS

ROR1 exhibited dramatically higher expression in lung adenocarcinoma, liver cancer and breast cancer, and targeting ROR1 by short-hairpin RNAs significantly inhibited proliferation and migration of cancer cells. Two humanized ROR1 monoclonal antibodies were successfully developed, named h1B8 and h6D4, with high specificity and affinity to ROR1 protein. Moreover, these two antibodies effectively suppressed tumor growth in the lung cancer xenograft mouse model, c-Myc/Alb-cre liver cancer transgenic mouse model and MMTV-PyMT breast cancer mouse model.

CONCLUSIONS

Two humanized monoclonal antibodies targeting ROR1, h1B8 and h6D4, were successfully developed and exhibited remarkable anti-tumor activity in vivo.

Unlocking the potential: advancements and future horizons in ROR1-targeted cancer therapies

While receptor tyrosine kinase-like orphan receptor 1 (ROR1) is typically expressed at low levels or absent in normal tissues, its expression is notably elevated in various malignant tumors and conditions, including chronic lymphocytic leukemia (CLL), breast cancer, ovarian cancer, melanoma, and lung adenocarcinoma. This distinctive feature positions ROR1 as an attractive target for tumor-specific treatments. Currently, several targeted drugs directed at ROR1 are undergoing clinical development, including monoclonal antibodies, antibody-drug conjugates (ADCs), and chimeric antigen receptor T-cell therapy (CAR-T). Additionally, there are four small molecule inhibitors designed to bind to ROR1, presenting promising avenues for the development of PROTAC degraders targeting ROR1. This review offers updated insights into ROR1's structural and functional characteristics, embryonic development implications, cell survival signaling pathways, and evolutionary targeting strategies, all of which have the potential to advance the treatment of malignant tumors.

Discovery of Novel Receptor Tyrosine Kinase-like Orphan Receptor 1 (ROR1) Inhibitors for Cancer Treatment

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncogenic membrane protein in several malignancies and has been considered an attractive target for the treatment of human cancers. In this study, structure-based virtual screening and structure optimization were conducted to identify novel ROR1 inhibitors. Based on hit compound 2, 45 novel ROR1 inhibitors were designed and synthesized, and the detailed structure-activity relationship was investigated. Representative compound 19h potently binds ROR1 with a KD value of 0.10 μM, exhibiting antitumor activity in lung cancer and breast cancer cell lines (IC50: 0.36-1.37 μM). Additionally, a mechanism investigation demonstrated that compound 19h induces the apoptosis of tumor cells. Importantly, compound 19h significantly suppressed tumor growth in a mouse model without obvious toxicity. Overall, this work identified compound 19h as a new ROR1 inhibitor, providing a novel lead compound for the treatment of lung cancer and breast cancer.

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.

Efficiently targeting neuroblastoma with the combination of anti-ROR1 CAR NK cells and N-803 in vitro and in vivo in NB xenografts

The prognosis for children with recurrent and/or refractory neuroblastoma (NB) is dismal. The receptor tyrosine kinase-like orphan receptor 1 (ROR1), which is highly expressed on the surface of NB cells, provides a potential target for novel immunotherapeutics. Anti-ROR1 chimeric antigen receptor engineered ex vivo expanded peripheral blood natural killer (anti-ROR1 CAR exPBNK) cells represent this approach. N-803 is an IL-15 superagonist with enhanced biological activity. In this study, we investigated the in vitro and in vivo anti-tumor effects of anti-ROR1 CAR exPBNK cells with or without N-803 against ROR1+ NB models. Compared to mock exPBNK cells, anti-ROR1 CAR exPBNK cells had significantly enhanced cytotoxicity against ROR1+ NB cells, and N-803 further increased cytotoxicity. High-dimensional analysis revealed that N-803 enhanced Stat5 phosphorylation and Ki67 levels in both exPBNK and anti-ROR1 CAR exPBNK cells with or without NB cells. In vivo, anti-ROR1 CAR exPBNK plus N-803 significantly (p < 0.05) enhanced survival in human ROR1+ NB xenografted NSG mice compared to anti-ROR1 CAR exPBNK alone. Our results provide the rationale for further development of anti-ROR1 CAR exPBNK cells plus N-803 as a novel combination immunotherapeutic for patients with recurrent and/or refractory ROR1+ NB.

Wnt5a-mediated autophagy contributes to the epithelial-mesenchymal transition of human bronchial epithelial cells during asthma

BACKGROUND

The epithelial-mesenchymal transition (EMT) of human bronchial epithelial cells (HBECs) is essential for airway remodeling during asthma. Wnt5a has been implicated in various lung diseases, while its role in the EMT of HBECs during asthma is yet to be determined. This study sought to define whether Wnt5a initiated EMT, leading to airway remodeling through the induction of autophagy in HBECs.

METHODS

Microarray analysis was used to investigate the expression change of WNT5A in asthma patients. In parallel, EMT models were induced using 16HBE cells by exposing them to house dust mites (HDM) or interleukin-4 (IL-4), and then the expression of Wnt5a was observed. Using in vitro gain- and loss-of-function approaches via Wnt5a mimic peptide FOXY5 and Wnt5a inhibitor BOX5, the alterations in the expression of the epithelial marker E-cadherin and the mesenchymal marker protein were observed. Mechanistically, the Ca2+/CaMKII signaling pathway and autophagy were evaluated. An autophagy inhibitor 3-MA was used to examine Wnt5a in the regulation of autophagy during EMT. Furthermore, we used a CaMKII inhibitor KN-93 to determine whether Wnt5a induced autophagy overactivation and EMT via the Ca2+/CaMKII signaling pathway.

RESULTS

Asthma patients exhibited a significant increase in the gene expression of WNT5A compared to the healthy control. Upon HDM and IL-4 treatments, we observed that Wnt5a gene and protein expression levels were significantly increased in 16HBE cells. Interestingly, Wnt5a mimic peptide FOXY5 significantly inhibited E-cadherin and upregulated α-SMA, Collagen I, and autophagy marker proteins (Beclin1 and LC3-II). Rhodamine-phalloidin staining showed that FOXY5 resulted in a rearrangement of the cytoskeleton and an increase in the quantity of stress fibers in 16HBE cells. Importantly, blocking Wnt5a with BOX5 significantly inhibited autophagy and EMT induced by IL-4 in 16HBE cells. Mechanistically, autophagy inhibitor 3-MA and CaMKII inhibitor KN-93 reduced the EMT of 16HBE cells caused by FOXY5, as well as the increase in stress fibers, cell adhesion, and autophagy.

CONCLUSION

This study illustrates a new link in the Wnt5a-Ca2+/CaMKII-autophagy axis to triggering airway remodeling. Our findings may provide novel strategies for the treatment of EMT-related diseases.

Heterogeneous Profile of ROR1 Protein Expression across Tumor Types

The Wnt receptor ROR1 has generated increased interest as a cancer therapeutic target. Research on several therapeutic approaches involving this receptor is ongoing; however, ROR1 tissue expression remains understudied. We performed an immunohistochemistry analysis of ROR1 protein expression in a large cohort of multiple tumor and histologic types. We analyzed 12 anonymized multi-tumor tissue microarrays (TMAs), including mesothelioma, esophageal and upper gastrointestinal carcinomas, and uterine endometrioid carcinoma, among other tumor types. Additionally, we studied 5 different sarcoma types of TMAs and 6 patient-derived xenografts (PDX) TMAs developed from 19 different anatomic sites and tumor histologic types. A total of 1142 patient cases from different histologic types and 140 PDXs placed in TMAs were evaluated. Pathologists assessed the percentage of tumor cells in each case that were positive for ROR1 and the intensity of staining. For determining the prevalence of staining for each tumor type, a case was considered positive if >1% of its tumor cells showed ROR1 staining. Our immunohistochemistry assays revealed a heterogeneous ROR1 expression profile. A high prevalence of ROR1 expression was found in mesothelioma (84.6%), liposarcoma (36.1%), gastrointestinal stromal tumors (33.3%), and uterine endometrioid carcinoma (28.9%). Other histologic types such as breast, lung, renal cell, hepatocellular, urothelial carcinoma, and colon carcinomas; glioblastoma; cholangiocarcinoma; and leiomyosarcoma showed less ROR1 overall expression, ranging between 0.9 and 13%. No ROR1 expression was seen in mesenchymal chondrosarcoma, rhabdomyosarcoma, or gastric adenocarcinoma cases. Overall, ROR1 expression was relatively infrequent and low in most tumor types investigated; however, ROR1 expression was infrequent but high in selected tumor types, such as gastroesophageal GIST, suggesting that ROR1 prescreening may be preferable for those indications. Further, mesothelioma exhibited frequent and high levels of ROR1 expression, which represents a previously unrecognized therapeutic opportunity. These findings can contribute to the development of ROR1-targeted therapies.

Revolutionizing pediatric neuroblastoma treatment: unraveling new molecular targets for precision interventions

Neuroblastoma (NB) is the most frequent solid tumor in pediatric cases, contributing to around 15% of childhood cancer-related deaths. The wide-ranging genetic, morphological, and clinical diversity within NB complicates the success of current treatment methods. Acquiring an in-depth understanding of genetic alterations implicated in the development of NB is essential for creating safer and more efficient therapies for this severe condition. Several molecular signatures are being studied as potential targets for developing new treatments for NB patients. In this article, we have examined the molecular factors and genetic irregularities, including those within insulin gene enhancer binding protein 1 (ISL1), dihydropyrimidinase-like 3 (DPYSL3), receptor tyrosine kinase-like orphan receptor 1 (ROR1) and murine double minute 2-tumor protein 53 (MDM2-P53) that play an essential role in the development of NB. A thorough summary of the molecular targeted treatments currently being studied in pre-clinical and clinical trials has been described. Recent studies of immunotherapeutic agents used in NB are also studied in this article. Moreover, we explore potential future directions to discover new targets and treatments to enhance existing therapies and ultimately improve treatment outcomes and survival rates for NB patients.

De Novo Discovery of Cysteine Frameworks for Developing Multicyclic Peptide Libraries for Ligand Discovery

Conserved cysteine frameworks are essential components of disulfide-rich peptides (DRPs), which dominantly define the structural diversity of both naturally occurring and de novo-designed DRPs. However, there are only very limited numbers of conserved cysteine frameworks, and general methods enabling de novo discovery of cysteine frameworks with robust foldability are still not available. Here, we devised a "touchstone"-based strategy that relies on chasing oxidative foldability between two individual disulfide-rich folds on the phage surface to discover new cysteine frameworks from random sequences. Unique cysteine frameworks with a high degree of compatibility with phage display systems and broad sequence tolerance were successfully identified, which were subsequently exploited for the development of multicyclic DRP libraries, enabling the rapid discovery of new peptide ligands with low-nanomolar and picomolar binding affinity. This study provides an unprecedented method for exploring and exploiting the sequence and structure space of DRPs that is not readily accessible by existing strategies, holding the potential to revolutionize the study of DRPs and significantly advance the design and discovery of multicyclic peptide ligands and drugs.