High expression of ROR2 in cancer cell correlates with unfavorable prognosis in colorectal cancer

miR-124-3p and miR-194-5p regulation of the PI3K/AKT pathway via ROR2 in medulloblastoma progression

Medulloblastoma (MB), a prevalent pediatric central nervous system tumor, is influenced by microRNAs (miRNAs) that impact tumor initiation and progression. However, the specific involvement of miRNAs in MB tumorigenesis remains unclear. Using single-cell RNA sequencing, we identified ROR2 expression in normal human fetal cerebellum. Subsequent analyses, including immunofluorescence, quantitative real-time PCR (qRT-PCR), and Western blot, assessed ROR2 expression in MB tissues and cell lines. We investigated miR-124-3p and miR-194-5p and their regulatory role in ROR2 expression through the dual-luciferase reporter, qRT-PCR, and western blot assays. Mechanistic insights were gained through functional assays exploring the impact of miR-124-3p, miR-194-5p, and ROR2 on MB growth in vitro and in vivo. We observed significantly reduced miR-124-3p and miR-194-5p expression and elevated ROR2 expression in MB tissues and cell lines. High ROR2 expression inversely correlated with overall survival in WNT and SHH subgroups of MB patients. Functionally, overexpressing miR-124-3p and miR-194-5p and inhibiting ROR2 suppressed in vitro malignant transformation and in vivo tumorigenicity. Mechanistically, miR-124-3p and miR-194-5p synergistically regulated the ROR2/PI3K/Akt pathway, influencing MB progression. Our findings indicate that miR-124-3p and miR-194-5p function as tumor suppressors, inhibiting MB progression via the ROR2/PI3K/Akt axis, suggesting a key mechanism and therapeutic targets for MB patients.

Multifactor dimensionality reduction method identifies novel SNP interactions in the WNT protein interaction networks that are associated with recurrence risk in colorectal cancer

Background

Interactions among genetic variants are rarely studied but may explain a part of the variability in patient outcomes.

Objectives

In this study, we aimed to identify 1 to 3 way interactions among SNPs from five Wnt protein interaction networks that predict the 5-year recurrence risk in a cohort of stage I-III colorectal cancer patients.

Methods

423 patients recruited to the Newfoundland Familial Colorectal Cancer Registry were included. Five Wnt family member proteins (Wnt1, Wnt2, Wnt5a, Wnt5b, and Wnt11) were selected. The BioGRID database was used to identify the proteins interacting with each of these proteins. Genotypes of the SNPs located in the interaction network genes were retrieved from a genome-wide SNP genotype data previously obtained in the patient cohort. The GMDR 0.9 program was utilized to examine 1-, 2-, and 3-SNP interactions using a 5-fold cross validation step. Top GMDR 0.9 models were assessed by permutation testing and, if significant, prognostic associations were verified by multivariable logistic regression models.

Results

GMDR 0.9 has identified novel 1, 2, and 3-way SNP interactions associated with 5-year recurrence risk in colorectal cancer. Nine of these interactions were multi loci interactions (2-way or 3-way). Identified interaction models were able to distinguish patients based on their 5-year recurrence-free status in multivariable regression models. The significance of interactions was the highest in the 3-SNP models. Several of the identified SNPs were eQTLs, indicating potential biological roles of the genes they were associated with in colorectal cancer recurrence.

Conclusions

We identified novel interacting genetic variants that associate with 5-year recurrence risk in colorectal cancer. A significant portion of the genes identified were previously linked to colorectal cancer pathogenesis or progression. These variants and genes are of interest for future functional and prognostic studies. Our results provide further evidence for the utility of GMDR models in identifying novel prognostic biomarkers and the biological importance of the Wnt pathways in colorectal cancer.

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.

Identification of potential and novel target genes in pituitary prolactinoma by bioinformatics analysis

Pituitary prolactinoma is one of the most complicated and fatally pathogenic pituitary adenomas. Therefore, there is an urgent need to improve our understanding of the underlying molecular mechanism that drives the initiation, progression, and metastasis of pituitary prolactinoma. The aim of the present study was to identify the key genes and signaling pathways associated with pituitary prolactinoma using bioinformatics analysis. Transcriptome microarray dataset GSE119063 was downloaded from Gene Expression Omnibus (GEO) database. Limma package in R software was used to screen DEGs. Pathway and Gene ontology (GO) enrichment analysis were conducted to identify the biological role of DEGs. A protein-protein interaction (PPI) network was constructed and analyzed by using HIPPIE database and Cytoscape software. Module analyses was performed. In addition, a target gene-miRNA regulatory network and target gene-TF regulatory network were constructed by using NetworkAnalyst and Cytoscape software. Finally, validation of hub genes by receiver operating characteristic (ROC) curve analysis. A total of 989 DEGs were identified, including 461 up regulated genes and 528 down regulated genes. Pathway enrichment analysis showed that the DEGs were significantly enriched in the retinoate biosynthesis II, signaling pathways regulating pluripotency of stem cells, ALK2 signaling events, vitamin D3 biosynthesis, cell cycle and aurora B signaling. Gene Ontology (GO) enrichment analysis showed that the DEGs were significantly enriched in the sensory organ morphogenesis, extracellular matrix, hormone activity, nuclear division, condensed chromosome and microtubule binding. In the PPI network and modules, SOX2, PRSS45, CLTC, PLK1, B4GALT6, RUNX1 and GTSE1 were considered as hub genes. In the target gene-miRNA regulatory network and target gene-TF regulatory network, LINC00598, SOX4, IRX1 and UNC13A were considered as hub genes. Using integrated bioinformatics analysis, we identified candidate genes in pituitary prolactinoma, which might improve our understanding of the molecular mechanisms of pituitary prolactinoma.

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.

The physiological role of Wnt pathway in normal development and cancer

Over the decades, many studies have illustrated the critical roles of Wnt signaling pathways in both developmental processes as well as tumorigenesis. Due to the complexity of Wnt signaling regulation, there are still questions to be addressed about ways cells are able to manipulate different types of Wnt pathways in order to fulfill the requirements for normal or cancer development. In this review, we will describe different types of Wnt signaling pathways and their roles in both normal developmental processes and their role in cancer development and progression. Additionally, we will briefly introduce new strategies currently in clinical trials targeting Wnt signaling pathway components for cancer therapy.

HCCR-1 is a Novel Prognostic Indicator for Gastric Cancer and Promotes Cell Proliferation

The role of the human cervical cancer oncogene (HCCR-1) in the development of various tumors has been elucidated; however, its expression and function in gastric cancer remains largely unknown. Accordingly, the expression of HCCR-1 and epidermal growth factor (EGF) were detected in paired gastric cancer tissues and cell lines by western blotting (WB) and immunohistochemistry (IHC). Furthermore, the correlations between HCCR-1 expression in 209 gastric cancer tissues and the clinicopathological features and disease prognosis were analyzed. A stable HCCR-1 overexpression cell line was established, and the influence of increased HCCR-1 expression on the growth of gastric cancer cells was observed in vivo and in vitro. The expression of HCCR-1 generally increased in gastric cancer tissues. Further, increased HCCR-1 expression in gastric cancer tissues was associated with tumor T stage and was an independent factor that influenced poor postoperative prognosis in gastric cancer patients. A positive correlation was also detected between the expression of EGF and HCCR-1 in a time- and dose-dependent manner. The overexpression of HCCR-1 might enhance the growth rate of gastric cancer cells in vitro, increase the number of colony forming units, and promote the growth, volume, and weight of subcutaneous tumors in nude mice. In conclusion, HCCR-1 is a gastric cancer oncogene, and its increased expression plays a critical role in the occurrence and development of gastric cancer. Hence, HCCR-1 could serve as a valuable marker for the postoperative prognostic assessment of gastric cancer patients.

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.

HAX-1 promotes the migration and invasion of hepatocellular carcinoma cells through the induction of epithelial-mesenchymal transition via the NF-κB pathway

The expression of HS-1-associated protein X-1 (HAX-1) plays a major role in the development of hepatocellular carcinoma (HCC). However, the function of HAX-1 in HCC metastasis is unclear. Quantitative real-time PCR and western blotting were used to examine HAX-1 expression in HCC cell lines with different metastatic potential, and in tumor tissues with or without intrahepatic metastasis. HCC tissue arrays (n = 144) were used to assess correlations between clinicopathological parameters and HAX-1 expression. We also examined the effect of HAX-1 on promoting HCC cell metastasis in vivo and in vitro. The results showed that the expression levels of HAX-1 were higher in metastatic HCC cell lines than in non-metastatic HCC cell lines. HAX-1 was also significantly upregulated in primary HCC tissues with intrahepatic metastasis compared with those without intrahepatic metastasis. HCC in patients with high HAX-1 expression is more likely to metastasize. HAX-1 expression was associated with malignant progression and poor prognosis, and HAX1 silencing inhibited HCC cell migration and invasion in vitro and decreased HCC cell lung metastasis in vivo, whereas HAX-1 overexpression had the inverse effect. Moreover, HAX-1 increased HCC cell metastasis by promoting the epithelial-mesenchymal transition (EMT) process. Finally, we revealed that HAX-1 modulated EMT in HCC cells by increasing NF-κB/p65 nuclear translocation. In conclusion, HAX-1 promotes HCC metastasis by EMT through activating the NF-κB pathway, suggesting that HAX-1 could be a potential therapeutic target for HCC treatment.

Intraflagellar transport 20 promotes collective cancer cell invasion by regulating polarized organization of Golgi-associated microtubules

Collective invasion is an important strategy of cancers of epithelial origin, including colorectal cancer (CRC), to infiltrate efficiently into local tissues as collective cell groups. Within the groups, cells at the invasive front, called leader cells, are highly polarized and motile, thereby providing the migratory traction that guides the follower cells. However, its underlying mechanisms remain unclear. We have previously shown that signaling emanating from the receptor tyrosine kinase Ror2 can promote invasion of human osteosarcoma cells and that intraflagellar transport 20 (IFT20) mediates its signaling to regulate Golgi structure and transport. Herein, we investigated the role of Ror2 and IFT20 in collective invasion of CRC cells, where Ror2 expression is either silenced or nonsilenced. We show by cell biological analyses that IFT20 promotes collective invasion of CRC cells, irrespective of expression and function of Ror2. Intraflagellar transport 20 is required for organization of Golgi‐associated, stabilized microtubules, oriented toward the direction of invasion in leader cells. Our results also indicate that IFT20 promotes reorientation of the Golgi apparatus toward the front side of leader cells. Live cell imaging of the microtubule plus‐end binding protein EB1 revealed that IFT20 is required for continuous polarized microtubule growth in leader cells. These results indicate that IFT20 plays an important role in collective invasion of CRC cells by regulating organization of Golgi‐associated, stabilized microtubules and Golgi polarity in leader cells.

Novel Antibody Drug Conjugates Targeting Tumor-Associated Receptor Tyrosine Kinase ROR2 by Functional Screening of Fully Human Antibody Libraries Using Transpo-mAb Display on Progenitor B Cells

Receptor tyrosine kinase-like orphan receptor 2 (ROR2) has been identified as a highly relevant tumor-associated antigen in a variety of cancer indications of high unmet medical need, including renal cell carcinoma and osteosarcoma, making it an attractive target for targeted cancer therapy. Here, we describe the de novo discovery of fully human ROR2-specific antibodies and potent antibody drug conjugates (ADCs) derived thereof by combining antibody discovery from immune libraries of human immunoglobulin transgenic animals using the Transpo-mAb mammalian cell-based IgG display platform with functional screening for internalizing antibodies using a secondary ADC assay. The discovery strategy entailed immunization of transgenic mice with the cancer antigen ROR2, harboring transgenic IgH and IgL chain gene loci with limited number of fully human V, D, and J gene segments. This was followed by recovering antibody repertoires from the immunized animals, expressing and screening them as full-length human IgG libraries by transposon-mediated display in progenitor B lymphocytes ("Transpo-mAb Display") for ROR2 binding. Individual cellular "Transpo-mAb" clones isolated by single cell sorting and capable of expressing membrane-bound as well as secreted human IgG were directly screened during antibody discovery, not only for high affinity binding to human ROR2, but also functionally as ADCs using a cytotoxicity assay with a secondary anti-human IgG-toxin-conjugate. Using this strategy, we identified and validated 12 fully human, monoclonal anti-human ROR2 antibodies with nanomolar affinities that are highly potent as ADCs and could be promising candidates for the therapy of human cancer. The screening for functional and internalizing antibodies during the early phase of antibody discovery demonstrates the utility of the mammalian cell-based Transpo-mAb Display platform to select for functional binders and as a powerful tool to improve the efficiency for the development of therapeutically relevant ADCs.

Upregulation of Spondin-2 protein expression correlates with poor prognosis in hepatocellular carcinoma

OBJECTIVE

The aim of this study was to measure the extracellular matrix protein Spondin-2 (SPON2) in hepatocellular carcinoma (HCC) tissues and to determine its potential value as a prognostic indicator by assessing its correlation with clinicopathological variables and survival.

METHODS

SPON2 mRNA expression was assessed in 20 matched pairs of HCC and non-cancerous liver tissues by quantitative reverse transcription-polymerase chain reaction analysis. SPON2 protein expression was determined in 107 matched pairs of HCC and normal liver tissue by immunohistochemical staining of tissue microarrays.

RESULTS

Analysis of patient tissues and Oncomine datasets showed that SPON2 mRNA and SPON2 protein expression were both significantly upregulated in HCC tissues, compared with non-cancerous liver tissue; moreover, both correlated significantly with tumor size. Kaplan-Meier analysis revealed that HCC patients who showed high levels of cytoplasmic SPON2 protein had poorer survival following curative resection, compared with HCC patients who exhibited low protein expression levels. Multivariate Cox regression analysis showed that tumor thrombus and SPON2 protein expression both independently correlated with reduced survival in HCC patients.

CONCLUSION

Upregulated expression of SPON2 protein in tumor tissue could be an effective prognostic indicator for patients with HCC.

ROR2 receptor promotes the migration of osteosarcoma cells in response to Wnt5a

Background

We have reported that the phosphatidylinositol-3 kinase (PI3K)/Akt/RhoA signaling pathway mediates Wnt5a-induced cell migration of osteosarcoma cells. However, the specific receptors responding to Wnt5a ligand remain poorly defined in osteosarcoma metastasis.

Methods

Wound healing assays were used to measure the migration rate of osteosarcoma cells transfected with shRNA or siRNA specific against ROR2 or indicated constructs. We evaluated the RhoA activation in osteosarcoma MG-63 and U2OS cells with RhoA activation assay. A panel of inhibitors of PI3K and Akt treated osteosarcoma cells and blocked kinase activity. Western blotting assays were employed to measure the expression and activation of Akt. Clonogenic assays were used to measure the cell proliferation of ROR2-knockdown or ROR2-overexpressed osteosarcoma cells.

Results

Wnt5a-induced osteosarcoma cell migration was largely abolished by shRNA or siRNA specific against ROR2. Overexpression of RhoA-CA (GFP-RhoA-V14) was able to rescue the Wnt5a-induced cell migration blocked by ROR2 knockdown. The Wnt5a-induced activation of RhoA was mostly blocked by ROR2 knockdown, and elevated by ROR2 overexpression, respectively. Furthermore, we found that Wnt5a-induced cell migration was significantly retarded by RhoA-siRNA transfection or pretreatment of HS-173 (PI3Kα inhibitor), MK-2206 (Akt inhibitor), A-674563 (Akt1 inhibitor), or CCT128930 (Akt2 inhibitor). The activation of Akt was upregulated or downregulated by transfected with ROR2-Flag or ROR2-siRNA, respectively. Lastly, Wnt5a/ROR2 signaling does not alter the cell proliferation of MG-63 osteosarcoma cells.

Conclusions

Taken together, we demonstrate that ROR2 receptor responding to Wnt5a ligand activates PI3K/Akt/RhoA signaling and promotes the migration of osteosarcoma cells.

Distinct Patterns of Stromal and Tumor Expression of ROR1 and ROR2 in Histological Subtypes of Epithelial Ovarian Cancer

OBJECTIVE

The ROR1 and ROR2 receptor tyrosine kinases have both been implicated in ovarian cancer progression and have been shown to drive migration and invasion. There is an increasing importance of the role of stroma in ovarian cancer metastasis; however, neither ROR1 nor ROR2 expression in tumor or stromal cells has been analyzed in the same clinical cohort.

AIM

To determine ROR1 and ROR2 expression in ovarian cancer and surrounding microenvironment and examine associations with clinicopathological characteristics.

METHODS

Immunohistochemistry for ROR1 and ROR2 was used to assess receptor expression in a cohort of epithelial ovarian cancer patients (n=178). Results were analyzed in relation to clinical and histopathological characteristics and survival. Matched patient sample case studies of normal, primary, and metastatic lesions were used to examine ROR expression in relation to ovarian cancer progression.

RESULTS

ROR1 and ROR2 are abnormally expressed in malignant ovarian epithelium and stroma. Higher ROR2 tumor expression was found in early-stage, low-grade endometrioid carcinomas. ROR2 stromal expression was highest in the serous subtype. In matched patient case studies, metastatic samples had higher expression of ROR2 in the stroma, and a recurrent sample had the highest expression of ROR2 in both tumor and stroma.

CONCLUSION

ROR1 and ROR2 are expressed in tumor-associated stroma in all histological subtypes of ovarian cancer and hold potential as therapeutic targets which may disrupt tumor and stroma interactions.

Wnt/Planar Cell Polarity Signaling: New Opportunities for Cancer Treatment

Cancer cells are addicted to a large spectrum of extracellular cues implicated in initiation, stem cell renewal, tumor growth, dissemination in the body, and resistance to treatment. Wingless/Int-1 (Wnt) ligands and their associated signaling cascades contribute to most of these processes, paving the way for opportunities in therapeutic development. The developmental Wnt/planar cell polarity (PCP) pathway is the most recently described branch of Wnt signaling strongly implicated in cancer development at early and late stages. We describe here some of the latest knowledge accumulated on this pathway and the pending questions, present the most convincing findings about its role in cancer, and review the most promising strategies currently designed to target its components.

Low expression of RASSF10 is associated with poor survival in patients with colorectal cancer

The RASSF10 has been identified as a tumor suppressor in human colorectal cancer (CRC). However, the expression of RASSF10 in patients with CRC has not been evaluated for its potential use as a biomarker in the diagnosis and prognosis assessment of CRC. We analyzed the expression of RASSF10 mRNA (n=30) and protein (n=205) in CRC and matched noncancerous colon tissue samples to explore the relationships among RASSF10 expression, clinicopathological factors, and prognosis in patients with CRC. Our results showed that the expression of RASSF10 mRNA and protein in CRC-adjacent tissues was higher than that in CRC tissues. Low RASSF10 expression was associated with the T stage (P=.037, odds ratio, 0.664; 95% confidence interval, 0.452-0.975) and the N stage (P<.001, odds ratio, 0.318; 95% confidence interval, 0.184-0.549) of the tumors. In addition, univariate analysis revealed that patients with CRC with lower RASSF10 expression had poorer overall survival (OS; P<.001) and disease-free survival (DFS; P<.001). The 5-year OS and DFS rates were 48.2% and 28.3%, respectively, in patients with low RASSF10 expression and 82.2% and 62.6%, respectively, in patients with high RASSF10 expression. Multivariate Cox regression analysis revealed that the strongest predictors of OS and DFS were RASSF10 expression (P<.001 and P<.001, respectively), T stage (P=.003 and P=.009, respectively), and N stage (P=.005 and P=.026, respectively). These results demonstrate that low expression of RASSF10 in CRC tissues is significantly correlated with poor survival after curative resection and may serve as a useful biomarker predictive of CRC prognosis.

LAMP1 expression is associated with malignant behaviours and predicts unfavourable prognosis in laryngeal squamous cell carcinoma

Lysosome-associated membrane protein-1 (LAMP1) has been suggested to play complicated roles in cancer development and metastasis. The aim of this study was to explore the expression of LAMP1 in laryngeal squamous cell carcinoma (LSCC) and investigate the relationship between LAMP1 expression and clinicopathological characteristics in LSCC patients. One-step quantitative reverse transcription PCR (qPCR) tests (20 fresh LSCC and non-cancerous tissue samples) and immunohistochemistry (IHC) analyses (137 paraffin-embedded LSCC and non-cancerous tissue samples) were performed to evaluate the LAMP1 expression in both mRNA and protein levels. Results showed that the expression of LAMP1 in LSCC tissues was significantly higher than that in non-cancerous tissues. Furthermore, the expression level of LAMP1 protein was statistically associated with lymph node metastasis and TNM stage. Results of Kaplan-Meier survival and Cox regression analyses revealed that LSCC patients with high LAMP1 cytoplasmic expression (p=0.044), high cytoplasmic+low mesenchymal expression of LAMP1 (H+L) (p=0.015) and histopathological grade (p=0.014) encountered poor overall survival. The data implied that high LAMP1 expression is associated with unfavourable prognosis in LSCC patients, and LAMP1 may be identified as a novel prognostic biomarker.

RASSF10 is an epigenetically inactivated tumor suppressor and independent prognostic factor in hepatocellular carcinoma

Methylation of the Ras-association domain family 10 (RASSF10) promoter region correlates with clinicopathological characteristics and poor prognosis in several human cancers. Here, we examined RASSF10 expression in hepatocellular carcinoma (HCC) and its role in hepatocarcinogenesis. RASSF10 mRNA and protein levels were downregulated in both HCC cell lines and patient tissue samples. In patient tissues, low RASSF10 levels correlated with hepatocirrhosis, poor tumor differentiation, tumor thrombus and Barcelona Clinic Liver Cancer stage, and were indicative of increased tumor recurrence and reduced patient survival. Low RASSF10 expression was associated with promoter hypermethylation, which was in turn associated with polycyclic aromatic hydrocarbon and aflatoxin B1 exposure, but not DNA methyltransferase expression. Overexpression of RASSF10 in HCC cell lines suppressed cell growth and colony formation, and induced apoptosis by up- or down-regulating specific Bcl-2 family proteins. RASSF10 overexpression increased pro-apoptotic Bax and Bad levels, but decreased anti-apoptotic Bcl-2 and Bcl-xl expression. Overexpression also inhibited tumor formation in nude mice and reduced cell migration and invasion by inhibiting the epithelial-mesenchymal transition. RASSF10 knockdown promoted cell growth. Our results show that RASSF10 is frequently hypermethylated and down-regulated in HCC and can potentially serve as a useful biomarker predictive of HCC patient prognosis.

Validation of specificity of antibodies for immunohistochemistry: the case of ROR2

The Wnt signalling receptor receptor tyrosine kinase-like orphan receptor 2 (ROR2) is implicated in numerous human cancers. However, there have been conflicting reports regarding ROR2 expression, some studies showing upregulation and others downregulation of ROR2 in the same cancer type. The majority of these studies used immunohistochemistry (IHC) to detect ROR2 protein, without validation of the used antibodies. There appears to be currently no consensus on the antibody best suited for ROR2 detection or how ROR2 expression changes in various cancer types. We examined three commercially available ROR2 antibodies and found that only one bound specifically to ROR2. Another antibody cross-reacted with other proteins, and the third failed to detect ROR2 at all. ROR2 detection by IHC on 107 patient samples using the ROR2 specific antibody showed that the majority of colorectal cancers show loss of ROR2 protein. We found no association between ROR2 staining and poor patient survival, as had been previously reported. These results question the previously reported association between ROR2 and poor patient survival in colorectal cancer. Future studies should use fully validated antibodies when detecting ROR2 protein, as non-specific staining can lead to irrelevant observations and misinterpretations.

WNT5A and Its Receptors in the Bone-Cancer Dialogue

Wnt signaling is critical for tumorigenesis and skeletal remodeling. However, its contribution to the formation of metastatic bone lesions remains poorly defined. One major challenge of unraveling its role in cancer progression is the high complexity of Wnt signaling, which includes numerous ligands, receptors, and inhibitors, with intricate biological effects and specific signaling pathways depending on the cellular context. In this perspective, we summarize the role of the noncanonical Wnt ligand WNT5A in the development and metastatic process of osteotropic cancer entities. We focus on its tumor-suppressive function in breast cancer, tumor promoting effects in melanoma, and ambiguous role in prostate cancer, and discuss potential challenges and opportunities that may be associated with targeting Wnt signaling for cancer therapy and treatment of bone metastases. © 2016 American Society for Bone and Mineral Research.

ROR2 is epigenetically inactivated in the early stages of colorectal neoplasia and is associated with proliferation and migration

BACKGROUND

Colorectal cancer (CRC) is closely linked to Wnt signalling, with 94 % of cases exhibiting a Wnt related mutation. ROR2 is a receptor tyrosine kinase that is thought to repress β-catenin dependent Wnt signalling. Our study aims to determine if ROR2 is epigenetically silenced in CRC and determine if in vitro silencing of ROR2 potentiates Wnt signalling, and alters the proliferative, migratory or invasive potential of cells.

METHODS

ROR2 expression was examined in CRC cell lines and patient adenomas using qRT-PCR, while COBRA and bisulphite sequencing was used to analyse ROR2 promoter methylation. 258 patient primary tumour samples from publicly available databases were also examined for ROR2 expression and methylation. In addition, the functional effects of ROR2 modulation were investigated in HCT116 cells following ROR2 siRNA knockdown and in RKO and SW620 cells following ectopic ROR2 expression.

RESULTS

Reduced ROR2 expression was found to correlate with ROR2 promoter hypermethylation in colorectal cancer cell lines, carcinomas and adenomas. ROR2 expression was downregulated in 76.7 % (23/30) of CRC cell lines with increasing ROR2 promoter hypermethylation correlating with progressively lower expression. Analysis of 239 primary tumour samples from a publicly available cohort also found a significant correlation between reduced ROR2 expression and increased promoter methylation. Methylation analysis of 88 adenomas and 47 normal mucosa samples found greater percentage of adenoma samples to be methylated. Additional analysis also revealed that adenoma samples with reduced ROR2 expression also possessed ROR2 promoter hypermethylation. ROR2 knockdown in the CRC cell line HCT116 significantly decreased expression of the β-catenin independent Wnt targets genes JNK and NFATC1, increased cellular proliferation and migration but decreased invasion. When ROR2 was ectopically expressed in RKO and SW620 cells, there was no significant change to either cellular proliferation or migration.

CONCLUSION

ROR2 is frequently epigenetically inactivated by promoter hypermethylation in the early stages of colorectal neoplasia and this may contribute to colorectal cancer progression by increasing cellular proliferation and migration.

Low expression of fibulin-1 correlates with unfavorable prognosis in gastric cancer

The tumor-suppressing role of fibulin-1 has been described in several types of cancers. However, the expression and role of fibulin-1 in the development and progression of gastric cancer (GC) remain largely unknown. In this study, RT-PCR and immunochemistry were used to detect the fibulin-1 expression in GC samples. We have found that the fibulin-1 protein and mRNA levels were downregulated in GC. When investigating the correlation between fibulin-1 expression and clinicopathological characteristics, we have found that low fibulin-1 protein expression was associated with poor tumor differentiation and advanced N stage. Low fibulin-1 protein expression was also an independent prognostic factor for patient survival. To clarify the reason of fibulin-1 downregulation in GC, the mRNA expression and methylation status of fibulin-1 were examined in GC fresh tissue samples (n = 36). We found that the transcriptional expression of fibulin-1 was negatively associated with fibulin-1 promoter hypermethylation, and fibulin-1 hypermethylation was associated with Helicobacter pylori infection. Finally, the effects of fibulin-1 overexpression on cell proliferation and apoptosis were examined. We have found that fibulin-1 overexpression suppressed the growth of GC both in vitro and in vivo and induced apoptosis by increasing cleaved caspase-3 expression. In conclusion, fibulin-1 acts as a tumor suppressor gene, is frequently hypermethylated in GC, and can potentially serve as a useful biomarker for patient prognosis.

Functional Crosstalk Between WNT Signaling and Tyrosine Kinase Signaling in Cancer

Extensive molecular characterization of tumors has revealed that the activity of multiple signaling pathways is often simultaneously dampened or enhanced in cancer cells. Aberrant WNT signaling and tyrosine kinase signaling are two pathways that are frequently up- or downregulated in cancer. Although signaling pathways regulated by WNTs, tyrosine kinases, and other factors are often conceptualized as independent entities, the biological reality is likely much more complex. Understanding the mechanisms of crosstalk between multiple signal transduction networks is a key challenge for cancer researchers. The overall goals of this review are to describe mechanisms of crosstalk between WNT and tyrosine kinase pathways in cancer and to discuss how understanding intersections between WNT and tyrosine kinase signaling networks might be exploited to improve current therapies.

Ror2 as a therapeutic target in cancer

Ror2 is a signaling receptor for Wnt ligands that is known to play important roles in limb development, but having no essential roles known in adult tissues. Recent evidence has implicated Ror2 in mediating both canonical and non-canonical signaling pathways. Ror2 was initially found to be highly expressed in osteosarcoma and renal cell carcinomas, and has recently been found in an increasingly long list of cancers currently including melanoma, colon cancer, melanoma, squamous cell carcinoma of the head and neck, and breast cancer. In the majority of these cancer types, Ror2 expression is associated with more aggressive disease states, consistent with a role mediating Wnt signaling regardless of the canonical or noncanonical signal. Because of the pattern of tissue distribution, the association with high-risk diseases, and the cell surface localization of this receptor, Ror2 has been identified as a potential high value target for therapeutic development. However, the recent discovery that Ror2 may function through non-kinase activities challenges this strategy and opens up opportunities to target this important molecule through alternative means.

Expression of Ror2 mediates invasive phenotypes in renal cell carcinoma

Ror2 is a Wnt ligand receptor that is overexpressed in a variety of tumors including clear cell renal cell carcinoma (ccRCC). Here we demonstrate that expression of wild type Ror2 results in increased tumorigenic properties in in vitro cell culture and in vivo xenograft models. In addition, Ror2 expression produced positive changes in both cell migration and invasion, which were dependent on matrix metalloprotease 2 (MMP2) activity. Mutations in key regions of the kinase domain of Ror2 resulted in the abrogation of increased tumor growth, cell migration, and cell invasion observed with expression of wild-type Ror2. Finally, we examined Ror2 expression as a prognostic biomarker for ccRCC utilizing the TCGA ccRCC dataset. High expression of Ror2 showed a significant correlation with higher clinical stage, nuclear grade, and tumor stage. Furthermore, high expression of Ror2 in ccRCC patients correlated with significant lower overall survival, cancer specific survival, and recurrence free survival. Together, these findings suggest that Ror2 plays a central role in influencing the ccRCC phenotype, and can be considered as a negative prognostic biomarker and potential therapeutic target in this cancer.