Loss of Reelin suppresses cell survival and mobility in non-Hodgkin lymphoma

Beyond the brain: Reelin's emerging role in cancer pathways

The glycoprotein Reelin is essential for neuronal migration during embryonic development and is involved in various cellular processes. It interacts with specific lipoprotein receptors to regulate neuronal migration and synaptic plasticity. Recent research has expanded our understanding of Reelin's functions, revealing its involvement in processes such as cell proliferation, activation, migration, platelet aggregation, and vascular development. Reelin's influence extends beyond neurodevelopment, with abnormal expression observed in several cancer types. This suggests a potential connection between Reelin dysregulation and tumor formation. Altered Reelin levels correlate with increased tumor aggressiveness, metastatic potential, and poor patient outcomes. In cancer, Reelin affects key cellular processes including proliferation, migration, and invasion. Evidence indicates that Reelin modulates important signaling pathways like PI3K/Akt and MAPK, contributing to the development of cancer hallmarks. Its interactions with integrins and matrix metalloproteinases imply a role in shaping the tumor microenvironment, thereby influencing cancer progression. These findings highlight Reelin's dual significance in neurodevelopment and cancer biology. Further investigation into Reelin's complex functions could lead to new diagnostic tools and therapeutic approaches, potentially advancing cancer treatment through targeted research on its signaling mechanisms. This review provides a condensed overview of Reelin's multifaceted roles in both neurodevelopment and cancer.

EZB-type diffuse large B-cell lymphoma cell lines have superior migration capabilities compared to MCD-type

Diffuse large B-cell lymphoma (DLBCL) represents the most prevalent aggressive B-cell lymphoma. The group is heterogeneous and the outcome is variable. A variety of approaches have been employed with the objective of improving the stratification of DLBCL patients according to their prognosis, based on the cell of origin. Recently, distinct genetic subtypes of DLBCL have been identified. Given the importance of cell migration in immune cells, the objective of this study was to ascertain whether different genetic subtypes of DLBCL exhibit disparate migration abilities. MCD- and EZB-type DLBCL cell lines were subjected to testing to ascertain their basal velocity in straight microchannels and their ability to overcome tight constrictions of 2 μm. The EZB-type cell lines showed superior basal migration velocity and constriction passage time, and a similar trend was observed in live cell imaging of native human DLBCL tissue. In addition, MCD-type DLBCL exhibited significantly elevated levels of nuclear lamin A/C, which is responsible for the stiffness of the nuclear envelope and could thus explain the disparate migration behaviours observed among these subtypes. Our study suggests that different genetic subtypes of DLBCL may not only influence the outcome after therapy but also the motility of the tumour cells.

The emerging role of miR-653 in human cancer

MicroRNAs (miRNAs) refer to a family of non-coding RNA with ~22 nucleotides in length. A high number of studies show evidence that deregulation in miRNAs expression could be implicated in the processes of many pathologies such as cancer, hypoxia, and stroke. Herein, we aimed to summarize the miR-653 expression level and molecular mechanisms through which it functions in human cancer. It was found that variations in miR-653 expression are linked to tumor aggressiveness and unfavorable prognosis in human cancer, and it plays an inhibitory effect in some types of cancer, such as breast, cervical, liver, renal, and lung cancers. In contrast, it plays an acceleratory impact in some other cancers, such as bladder and prostate cancers. In gastric cancer, the role played by miR-653 is still controversial and will need to be elucidated in future studies. Future studies could definitely establish targeting miR-653 as a novel strategy in human cancer, from diagnosis to effective treatment.

Tumor suppressor immune gene therapy to reverse immunotherapy resistance

BACKGROUND

While immune checkpoint inhibitors are becoming a standard of care for multiple types of cancer, the majority of patients do not respond to this form of immunotherapy. New approaches are required to overcome resistance to immunotherapies.

METHODS

We investigated the effects of adenoviral p53 (Ad-p53) gene therapy in combination with immune checkpoint inhibitors and selective IL2 or IL15 CD122/132 agonists in the aggressive B16F10 tumor model resistant to immunotherapies. To assess potential mechanisms of action, pre- and post- Ad-p53 treatment biopsies were evaluated for changes in gene-expression profiles by Nanostring IO 360 assays.

RESULTS

The substantial synergy of "triplet" Ad-p53 + CD122/132 + anti-PD-1 therapy resulted in potential curative effects associated with the complete tumor remissions of both the primary and contralateral tumors. Interestingly, contralateral tumors, which were not injected with Ad-p53 showed robust abscopal effects resulting in statistically significant decreases in tumor size and increased survival (p < 0.001). None of the monotherapies or doublet treatments induced the complete tumor regressions. Ad-p53 treatment increased interferon, CD8⁺ T cell, immuno-proteosome antigen presentation, and tumor inflammation gene signatures. Ad-p53 treatment also decreased immune-suppressive TGF-beta, beta-catenin, macrophage, and endothelium gene signatures, which may contribute to enhanced immune checkpoint inhibitor (CPI) efficacy. Unexpectedly, a number of previously unidentified, strongly p53 downregulated genes associated with stromal pathways and IL10 expression identified novel anticancer therapeutic applications.

CONCLUSIONS

These results imply the ability of Ad-p53 to induce efficacious local and systemic antitumor immune responses with the potential to reverse resistance to immune checkpoint inhibitor therapy when combined with CD122/132 agonists and immune checkpoint blockade. Our findings further imply that Ad-p53 has multiple complementary immune mechanisms of action, which support future clinical evaluation of triplet Ad-p53, CD122/132 agonist, and immune checkpoint inhibitor combination treatment.

Functional Heterogeneity of Reelin in the Oral Squamous Cell Carcinoma Microenvironment

Background

Reelin, an extracellular glycoprotein, is expressed on neuronal cells and participates in neuronal migration during brain development. Recently, Reelin also has a vital role in carcinogenesis. However, its role in oral squamous cell carcinoma (OSCC) remains to be explored. The purpose of this study was to explore the roles of Reelin in OSCC.

Methods

The expression of Reelin in cancer-associated fibroblasts (Reelin^CAF) and tumor cells (Reelin^TC) was analyzed by the Gene Expression Omnibus (GEO) database. Immunohistochemistry (IHC) was used to detect the spatial pattern of Reelin in 75 OSCCs. The diagnostic and prognostic values of Reelin were evaluated and also verified by The Cancer Genome Atlas (TCGA) database. Primary CAFs from 13 OSCC patients were isolated to confirm Reelin expression. Thirty-nine OSCC peripheral blood samples were used to analyze the change of immunocytes based on Reelin levels by flow cytometry. The relationship between Reelin and tumor immune microenvironment in head and neck squamous cell carcinoma (HNSCC) tissues was determined by TISIDB and the Tumor Immune Estimation Resource (TIMER) database.

Results

In breast cancer, pancreatic cancer and rectal cancer, Reelin in CAFs was significantly upregulated compared with Reelin in TCs. The IHC results in OSCC also showed that Reelin levels were higher in CAFs. Upregulated Reelin^TC was related to a decreased pN stage and distant metastasis. Strikingly, patients with enhanced Reelin^CAF had a high risk of lymph node metastasis, poor worst pattern of invasion (WPOI), and distant metastasis, but showed comparable Ki-67 level in all OSCC patients, resulting in shorter overall survival (OS) and disease-specific survival (DSS). Unexpectedly, Reelin in tumor-infiltrating lymphocytes (Reelin^TIL) was correlated with postoperative relapse. Patients with high Reelin^TIL, but not Reelin^TC and Reelin^CAF, had poor cytotoxicity of CD8⁺ T cells and higher ratio of CD4/CD8 in peripheral blood. However, Reelin was positively associated with tissue-resident B cells and NK cells in the tumor microenvironment.

Conclusion

Reelin has a versatile function in distinct cell types during the development of OSCC via governing tumor cell and stroma microenvironment.

Reelin depletion alleviates multiple myeloma bone disease by promoting osteogenesis and inhibiting osteolysis

Extracellular matrix glycoprotein Reelin is associated with tumor metastasis and prognosis in various malignancies. However, its effects on multiple myeloma (MM) are not fully understood. Here, we investigated the regulatory effects of Reelin on MM and its underlying pathogenic mechanisms. Lentivirus plasmid containing short hairpin RNA targeting Reelin (LV3-Reln) was transfected into SP2/0 cells to knockdown Reelin expression. Flow cytometry assay analyzed cell cycle and apoptosis while Transwell assay evaluated invasiveness. BALB/c mice were inoculated with LV3-Reln-transfected SP2/0 cells to establish MM model. Primary myeloma cells and osteoblasts/osteoclast were isolated from tumor tissue and limb long bones respectively. ELISA examined serum biomarkers and immunohistochemistry detected immunoglobulin light chain expression. Morphological changes and osteoclast/osteoblast differentiation were observed by histological staining. mRNA and proteins expression were determined by qPCR and WB. In vitro studies showed that Reelin depletion regulated osteolysis and osteogenesis balance, cell cycle, invasiveness, and apoptosis in SP2/0 cells. In LV3-Reln mice, tumor growth and invasiveness were suppressed, meanwhile, reduced osteoclast activation and enhanced osteoblast activity were observed. Reelin knockdown alleviated extramedullary morbidity and inhibited spleen immune cell apoptosis by down-regulating CDK5, IL-10, and Cyto-C expression. Furthermore, reduced Reelin expression restrained osteoclast differentiation while promoted osteogenesis in the bone of LV3-Reln mice. This was further supported by down-regulation of osteolytic specific mRNAs and proteins (Trap, Mmp9, Ctsk, Clcn7) and up-regulation of osteogenic specific ones (COL-1, Runx2, β-Catenin). Reelin exerted important impacts on myeloma development through rebalancing osteolysis and osteogenesis, thus might be a potential therapeutic target for MM.

The depletion of Circ-PRKDC enhances autophagy and apoptosis in T-cell acute lymphoblastic leukemia via microRNA-653-5p/Reelin mediation of the PI3K/AKT/mTOR signaling pathway

A range of circular (Circ) RNAs have been demonstrated to be of therapeutic significance for the treatment of acute lymphoblastic leukemia (ALL). Here, we investigated the mechanisms underlying the action of Circ-PRKDC and the microRNA-653-5p/Reelin (miR-653-5p/RELN) axis in T-cell ALL (T-ALL).Clinical specimens were obtained from patients with T-ALL (n = 39) and healthy controls (n = 30). In each specimen, we determined the expression levels of Circ-PRKDC, miR-653-5p, and RELN. Human T-ALL cells (Jurkat) were transfected with Circ-PRKDC- or miR-653-5p-related sequences to investigate cell proliferation, apoptosis, and autophagy. We also determined the levels of Circ-PRKDC, miR-653-5p, RELN, and signaling proteins related to phosphoinositide 3-kinase (PI3K), AKT, and mammalian target of rapamycin (mTOR). Finally, we decoded the interactions between Circ-PRKDC, miR-653-5p, and RELN. The expression levels of Circ-PRKDC and RELN were upregulated in T-ALL tissues and cells while the levels of miR-653-5p were downregulated. Thereafter, then silencing of Circ-PRKDC, or the enforced expression of miR-653-5p, repressed the expression of RELN and the activation of the PI3K/AKT/mTOR signaling pathway, thus enhancing cell autophagy and apoptosis, and disrupting cell proliferation. Circ-PRKDC acted a sponge for miR-653-5p while miR-653-5p targeted RELN. The knockdown of miR-653-5p abrogated the silencing of Circ-PRKDC-induced effects in T-ALL cells. The depletion of Circ-PRKDC elevated miR-653-5p to silence RELN-mediated PI3K/AKT/mTOR signaling activation, thereby enhancing autophagy and apoptosis in T-ALL cells.

Reelin Promotes Cisplatin Resistance by Induction of Epithelial-Mesenchymal Transition via p38/GSK3β/Snail Signaling in Non-Small Cell Lung Cancer

Background

Emerging evidence suggests the involvement of Reelin in chemoresistance in various cancers. However, its function in cisplatin (DDP) sensitivity of non-small cell lung cancer (NSCLC) needs to be investigated.

Material/Methods

Reelin expression in cisplatin-sensitive A549 cells and cisplatin-resistant NSCLC (A549/DDP) cells was analyzed by western blot analysis. qRT-PCR, western blotting, immunofluorescence, CCK-8 assays, Annexin V/propidium iodide apoptosis assay, and Transwell migration assays were carried out to determine the function of Reelin on DDP resistance.

Results

Reelin was markedly increased in A549/DDP cells relative to A549 cells. Knockdown of Reelin enhanced DDP chemosensitivity of A549/DDP cells, whereas overexpression of Reelin enhanced DDP resistance of A549, H1299, and H460 cells. Reelin induced DDP resistance in NSCLC cells via facilitating epithelial-mesenchymal transition (EMT). Furthermore, Reelin modulated p38/GSK3β signal transduction and promoted Snail (EMT-associated transcription factor) expression. Suppression of p38/Snail reversed Reelin-induced EMT and resistance of NSCLC cells to DDP.

Conclusions

These data indicated that Reelin induces DDP resistance of NSCLC by regulation of the p38/GSK3β/Snail/EMT signaling pathway and provide evidence that Reelin suppression can be an effective strategy to suppress DDP resistance in NSCLC.

Downregulation of reelin predicts poor prognosis for glioma

Aim: In the present study, we studied the relationship between RELN and prognosis in glioma. Materials & methods: Expression profiles and methylation data of RELN were obtained from bioinformatic datasets. Correlations between RELN and clinicopathological features and overall survival were respectively assessed using chi-square test and Kaplan-Meier analysis. Results: RELN was downregulated in glioma, and its downregulation correlated well with glioma malignancy and overall survival. Meanwhile, hypermethylation of RELN was significantly correlated with low RELN expression. Additionally, gene set enrichment analysis demonstrated that low expression of RELN correlated with many key cancer pathways, possibly highlighting the importance of RELN in carcinogenesis of brain. Conclusion: RELN may serve as a potential prognostic marker and promising target molecule for new therapy of glioma.

ApoER2 (Apolipoprotein E Receptor-2) Deficiency Accelerates Smooth Muscle Cell Senescence via Cytokinesis Impairment and Promotes Fibrotic Neointima After Vascular Injury

OBJECTIVE

Genome-wide studies showed that mutation in apoER2 (apolipoprotein E receptor-2) is additive with ε4 polymorphism in the APOE gene on cardiovascular disease risk in humans. ApoE or apoER2 deficiency also accelerates atherosclerosis lesion necrosis in hypercholesterolemic mice and promotes neointima formation after vascular injury. This study tests the hypothesis that apoE and apoER2 modulate vascular occlusive diseases through distinct mechanisms. Approach and Results: Carotid endothelial denudation induced robust neointima formation in both apoE-/- and apoER2-deficient Lrp8-/- mice. The intima in apoE-/- mice was rich in smooth muscle cells, but the intima in Lrp8-/- mice was cell-poor and rich in extracellular matrix. Vascular smooth muscle cells isolated from apoE-/- mice were hyperplastic whereas Lrp8-/- smooth muscle cells showed reduced proliferation but responded robustly to TGF (transforming growth factor)-β-induced fibronectin synthesis indicative of a senescence-associated secretory phenotype, which was confirmed by increased β-galactosidase activity, p16INK4a immunofluorescence, and number of multinucleated cells. Western blot analysis of cell cycle-associated proteins showed that apoER2 deficiency promotes cell cycle arrest at the metaphase/anaphase. Coimmunoprecipitation experiments revealed that apoER2 interacts with the catalytic subunit of protein phosphatase 2A. In the absence of apoER2, PP2A-C (protein phosphatase 2A catalytic subunit) failed to interact with CDC20 (cell-division cycle protein 20) thus resulting in inactive anaphase-promoting complex and impaired cell cycle exit.

CONCLUSIONS

This study showed that apoER2 participates in APC (anaphase-promoting complex)/CDC20 complex formation during mitosis, and its absence impedes cytokinesis abscission thereby accelerating premature cell senescence and vascular disease. This mechanism is distinct from apoE deficiency, which causes smooth muscle cell hyperplasia to accelerate vascular disease.

Genome reorganization in different cancer types: detection of cancer specific breakpoint regions

Background

Tumorigenesis is a multi-step process which is accompanied by substantial changes in genome organization. The development of these changes is not only a random process, but rather comprise specific DNA regions that are prone to the reorganization process.

Results

We have analyzed previously published SNP arrays from three different cancer types (pancreatic adenocarcinoma, breast cancer and metastatic melanoma) and from non-malignant control samples. We calculated segmental copy number variations as well as breakpoint regions. Some of these regions were not randomly involved in genome reorganization since we detected fifteen of them in at least 20% of all tumor samples and one region on chromosome 9 where 43% of tumors have a breakpoint. Further, the top-15 breakpoint regions show an association to known fragile sites. The relevance of these common breakpoint regions was further confirmed by analyzing SNP arrays from 917 cancer cell lines.

Conclusion

Our analyses suggest that genome reorganization is common in tumorigenesis and that some breakpoint regions can be found across all cancer types, while others exclusively occur in specific entities.

Identification of potential drugs for diffuse large b-cell lymphoma based on bioinformatics and Connectivity Map database

Diffuse large B-cell lymphoma (DLBCL) is the most main subtype in non-Hodgkin lymphoma. After chemotherapy, about 30% of patients with DLBCL develop resistance and relapse. This study was to identify potential therapeutic drugs for DLBCL using the bioinformatics method. The differentially expressed genes (DEGs) between DLBCL and non-cancer samples were downloaded from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DEGs were analyzed using the Database for Annotation, Visualization, and Integrated Discovery. The R software package (SubpathwayMiner) was used to perform pathway analysis on DEGs affected by drugs found in the Connectivity Map (CMap) database. Protein-protein interaction (PPI) networks of DEGs were constructed using the Search Tool for the Retrieval of Interacting Genes online database and Cytoscape software. In order to identify potential novel drugs for DLBCL, the DLBCL-related pathways and drug-affected pathways were integrated. The results showed that 1927 DEGs were identified from TCGA and GEO. We found 54 significant pathways of DLBCL using KEGG pathway analysis. By integrating pathways, we identified five overlapping pathways and 47 drugs that affected these pathways. The PPI network analysis results showed that the CDK2 is closely associated with three overlapping pathways (cell cycle, p53 signaling pathway, and small cell lung cancer). The further literature verification results showed that etoposide, rinotecan, methotrexate, resveratrol, and irinotecan have been used as classic clinical drugs for DLBCL. Anisomycin, naproxen, gossypol, vorinostat, emetine, mycophenolic acid and daunorubicin also act on DLBCL. It was found through bioinformatics analysis that paclitaxel in the drug-pathway network can be used as a potential novel drug for DLBCL.