Reelin is involved in transforming growth factor-β1-induced cell migration in esophageal carcinoma cells

iPSC-Derived Astrocytes and Neurons Replicate Brain Gene Expression, Epigenetic, Cell Morphology and Connectivity Alterations Found in Autism

Excessive inflammatory reactions and oxidative stress are well-recognized molecular findings in autism and these processes can affect or be affected by the epigenetic landscape. Nonetheless, adequate therapeutics are unavailable, as patient-specific brain molecular markers for individualized therapies remain challenging.

METHODS

We used iPSC-derived neurons and astrocytes of patients with autism vs. controls (5/group) to examine whether they replicate the postmortem brain expression/epigenetic alterations of autism. Additionally, DNA methylation of 10 postmortem brain samples (5/group) was analyzed for genes affected in PSC-derived cells.

RESULTS

We found hyperexpression of TGFB1, TGFB2, IL6 and IFI16 and decreased expression of HAP1, SIRT1, NURR1, RELN, GPX1, EN2, SLC1A2 and SLC1A3 in the astrocytes of patients with autism, along with DNA hypomethylation of TGFB2, IL6, TNFA and EN2 gene promoters and a decrease in HAP1 promoter 5-hydroxymethylation in the astrocytes of patients with autism. In neurons, HAP1 and IL6 expression trended alike. While HAP1 promoter was hypermethylated in neurons, IFI16 and SLC1A3 promoters were hypomethylated and TGFB2 exhibited increased promoter 5-hydroxymethlation. We also found a reduction in neuronal arborization, spine size, growth rate, and migration, but increased astrocyte size and a reduced growth rate in autism. In postmortem brain samples, we found DNA hypomethylation of TGFB2 and IFI16 promoter regions, but DNA hypermethylation of HAP1 and SLC1A2 promoters in autism.

CONCLUSION

Autism-associated expression/epigenetic alterations in iPSC-derived cells replicated those reported in the literature, making them appropriate surrogates to study disease pathogenesis or patient-specific therapeutics.

PI3K/mTOR is a therapeutically targetable genetic dependency in diffuse intrinsic pontine glioma

Diffuse midline glioma (DMG), including tumors diagnosed in the brainstem (diffuse intrinsic pontine glioma; DIPG), are uniformly fatal brain tumors that lack effective treatment. Analysis of CRISPR/Cas9 loss-of-function gene deletion screens identified PIK3CA and MTOR as targetable molecular dependencies across patient derived models of DIPG, highlighting the therapeutic potential of the blood-brain barrier-penetrant PI3K/Akt/mTOR inhibitor, paxalisib. At the human-equivalent maximum tolerated dose, mice treated with paxalisib experienced systemic glucose feedback and increased insulin levels commensurate with patients using PI3K inhibitors. To exploit genetic dependence and overcome resistance while maintaining compliance and therapeutic benefit, we combined paxalisib with the antihyperglycemic drug metformin. Metformin restored glucose homeostasis and decreased phosphorylation of the insulin receptor in vivo, a common mechanism of PI3K-inhibitor resistance, extending survival of orthotopic models. DIPG models treated with paxalisib increased calcium-activated PKC signaling. The brain penetrant PKC inhibitor enzastaurin, in combination with paxalisib, synergistically extended the survival of multiple orthotopic patient-derived and immunocompetent syngeneic allograft models; benefits potentiated in combination with metformin and standard-of-care radiotherapy. Therapeutic adaptation was assessed using spatial transcriptomics and ATAC-Seq, identifying changes in myelination and tumor immune microenvironment crosstalk. Collectively, this study has identified what we believe to be a clinically relevant DIPG therapeutic combinational strategy.

Connexin Expression Is Altered in Liver Development of Yotari (dab1 -/-) Mice

Disabled-1 (Dab1) protein is an intracellular adaptor of reelin signaling required for prenatal neuronal migration, as well as postnatal neurotransmission, memory formation and synaptic plasticity. Yotari, an autosomal recessive mutant of the mouse Dab1 gene is recognizable by its premature death, unstable gait and tremor. Previous findings are mostly based on neuronal abnormalities caused by Dab1 deficiency, but the role of the reelin signaling pathway in nonneuronal tissues and organs has not been studied until recently. Hepatocytes, the most abundant cells in the liver, communicate via gap junctions (GJ) are composed of connexins. Cell communication disruption in yotari mice was examined by analyzing the expression of connexins (Cxs): Cx26, Cx32, Cx37, Cx40, Cx43 and Cx45 during liver development at 13.5 and 15.5 gestation days (E13.5 and E15.5). Analyses were performed using immunohistochemistry and fluorescent microscopy, followed by quantification of area percentage covered by positive signal. Data are expressed as a mean ± SD and analyzed by one-way ANOVA. All Cxs examined displayed a significant decrease in yotari compared to wild type (wt) individuals at E13.5. Looking at E15.5 we have similar results with exception of Cx37 showing negligible expression in wt. Channels formation triggered by pathological stimuli, as well as propensity to apoptosis, was studied by measuring the expression of Pannexin1 (Panx1) and Apoptosis-inducing factor (AIF) through developmental stages mentioned above. An increase in Panx1 expression of E15.5 yotari mice, as well as a strong jump of AIF in both phases suggesting that yotari mice are more prone to apoptosis. Our results emphasize the importance of gap junction intercellular communication (GJIC) during liver development and their possible involvement in liver pathology and diagnostics where they can serve as potential biomarkers and drug targets.

Heterozygous missense mutation of the RELN gene is one of the causes of epilepsy

OBJECTIVES

Genetic factors play an important role in the onset of epilepsy, and the involvement of the RELN gene was recently discovered. This paper reports a family with a history of epilepsy caused by a heterozygous missense mutation in the RELN gene.

METHODS

After a clear diagnosis was made in the proband with a family history of epilepsy, gene sequencing was performed on the proband and his family members.

RESULTS

The proband was a 19-year-old male who presented with general convulsions during sleep lasting for about 1 min and was relieved spontaneously. His father and grandmother also experienced seizures. The gene sequencing results of the proband, his mother, and his grandmother showed that both the proband and his grandmother carried the same heterozygous missense mutation in the RELN gene (c.7909 C > T), unlike the proband's mother.

DISCUSSION

Mutations in the RELN gene can lead to the occurrence of benign epilepsy, though the specific type of seizures that it can cause is still unclear, and may increase the susceptibility to epilepsy. In addition, it may have potential anticancer effects.

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.

Identifying Critical States of Complex Diseases by Single-Sample Jensen-Shannon Divergence

MOTIVATION

The evolution of complex diseases can be modeled as a time-dependent nonlinear dynamic system, and its progression can be divided into three states, i.e., the normal state, the pre-disease state and the disease state. The sudden deterioration of the disease can be regarded as the state transition of the dynamic system at the critical state or pre-disease state. How to detect the critical state of an individual before the disease state based on single-sample data has attracted many researchers' attention.

METHODS

In this study, we proposed a novel approach, i.e., single-sample-based Jensen-Shannon Divergence (sJSD) method to detect the early-warning signals of complex diseases before critical transitions based on individual single-sample data. The method aims to construct score index based on sJSD, namely, inconsistency index (ICI).

RESULTS

This method is applied to five real datasets, including prostate cancer, bladder urothelial carcinoma, influenza virus infection, cervical squamous cell carcinoma and endocervical adenocarcinoma and pancreatic adenocarcinoma. The critical states of 5 datasets with their corresponding sJSD signal biomarkers are successfully identified to diagnose and predict each individual sample, and some "dark genes" that without differential expressions but are sensitive to ICI score were revealed. This method is a data-driven and model-free method, which can be applied to not only disease prediction on individuals but also targeted drug design of each disease. At the same time, the identification of sJSD signal biomarkers is also of great significance for studying the molecular mechanism of disease progression from a dynamic perspective.

Integrin α3β1 Represses Reelin Expression in Breast Cancer Cells to Promote Invasion

Simple Summary

Breast cancer remains the second leading cause of cancer-related deaths in women, and about 1 in 8 women in the United States develops invasive breast cancer in her lifetime. Integrin α3β1 has been linked to breast cancer progression, but mechanisms whereby it promotes tumor invasion remain unclear. The goal of our study was to determine how α3β1 drives invasion, towards exploiting this integrin as a therapeutic target for breast cancer. We found that α3β1 represses the expression of Reelin, a secreted glycoprotein that inhibits invasion and for which loss of expression is associated with poor prognosis in breast cancer. We also show that increased Reelin expression following RNAi-mediated suppression of α3β1 causes a significant decrease in breast cancer cell invasion. Our findings demonstrate a critical role for α3β1 in promoting cell invasion through repression of Reelin, highlighting the potential value of this integrin as a therapeutic target for breast cancer.

Abstract

Integrin α3β1, a cell adhesion receptor for certain laminins, is known to promote breast tumor growth and invasion. Our previous gene microarray study showed that the RELN gene, which encodes the extracellular glycoprotein Reelin, was upregulated in α3β1-deficient (i.e., α3 knockdown) MDA-MB-231 cells. In breast cancer, reduced RELN expression is associated with increased invasion and poor prognosis. In this study we demonstrate that α3β1 represses RELN expression to enhance breast cancer cell invasion. RELN mRNA was significantly increased upon RNAi-mediated α3 knockdown in two triple-negative breast cancer cell lines, MDA-MB-231 and SUM159. Modulation of baseline Reelin levels altered invasive potential, where enhanced Reelin expression in MDA-MB-231 cells reduced invasion, while RNAi-mediated suppression of Reelin in SUM159 cells increased invasion. Moreover, treatment of α3β1-expressing MDA-MB-231 cells with culture medium that was conditioned by α3 knockdown MDA-MB-231 cells led to decreased invasion. RNAi-mediated suppression of Reelin in α3 knockdown MDA-MB-231 cells mitigated this effect of conditioned-medium, identifying secreted Reelin as an inhibitor of cell invasion. These results demonstrate a novel role for α3β1 in repressing Reelin in breast cancer cells to promote invasion, supporting this integrin as a potential therapeutic target.

Calycosin induces mitochondrial-dependent apoptosis and cell cycle arrest, and inhibits cell migration through a ROS-mediated signaling pathway in HepG2 hepatocellular carcinoma cells

Calycosin is one of the main ingredients extracted from the Chinese medical herb, Radix astragali (RA). It has been shown to inhibit cell proliferation and induce apoptosis in several cancer cell lines, but the underlying mechanism remains unclear. The effects of calycosin on the proliferation and apoptosis of hepatocellular carcinoma (HCC) cells, as well as its mechanism, were investigated in this study. Cell Counting Kit-8 assay results suggested that calycosin had anti-proliferation effects on HCC in dose- and time-dependent manners, and had less cytotoxicity in normal cells. Hoechst/PI double staining and flow cytometry results showed cellular morphological changes and apoptosis after treatment of HepG2 cells with calycosin. The western blot assay showed calycosin decreased the expression of Bcl-2 and increased the expression of Bax, caspase-3, and PARP. Calycosin induced the activation of MAPK, STAT3, NF-κB, apoptosis-related proteins, and induced cell cycle arrest in the G0/G1 phase by regulating AKT. In addition, calycosin reduced the expression of TGF-β1, SMAD2/3, SLUG, and vimentin. Furthermore, phosphorylation, apoptosis, and cell migration induced by calycosin were mediated by the production of reactive oxygen species. These events could be inhibited by pretreatment with N-acetyl-L-cysteine. Calycosin resisted HCC by activating ROS-mediated MAPK, STAT3, and NF-κB signaling pathways.

Identification of Apolipoprotein E as a Potential Diagnostic Biomarker of Nasopharyngeal Carcinoma

Purpose

Apo-E, a secreted protein, is closely related to the migration and invasion of tumor cells. In this study, we aimed to analyze the expression of Apo-E in nasopharyngeal carcinoma (NPC) patients and cell lines, as well as its effects on NPC cell behavior.

Patients and Methods

Our study included 35 patients with NPC from Zhongnan Hospital. Expression levels of Apo-E in patients with NPC were examined by quantitative reverse transcription-polymerase chain reaction, Western blot, and immunohistochemical (IHC) staining. Receiver operating characteristic (ROC) curves were analyzed using the SPSS 22 software to estimate the sensitivity and specificity of the Apo-E protein in diagnosing NPC. Additionally, the level of Apo-E in NPC cell lines (NP69, 6–10B, and 5–8F) was investigated by Western blotting and IHC.

Results

Levels of Apo-E were higher in NPC patients than in controls. Moreover, ROC analysis revealed that increased Apo-E in the serum of NPC patients may act as a potential biomarker for NPC diagnosis (Area under the curve 0.917). Furthermore, similar results were also identified in NPC cancer cell lines. RNA interference technology was used to overexpress the endogenous Apo-E in the NPC cell line 6–10B. Wound healing and transwell assays indicated that the overexpression of Apo-E increased the number of cell colonies and migration ability, respectively.

Conclusion

In this study, we found that Apo-E was elevated in NPC patients and may act as a potential biomarker for NPC diagnosis. In addition, Apo-E was upregulated in NPC cell lines and promoted cell growth, migration, and invasion.

Sarcomatoid renal cell carcinoma: biology, natural history and management

Sarcomatoid dedifferentiation is an uncommon feature that can occur in most histological subtypes of renal cell carcinomas (RCCs) and carries a decidedly poor prognosis. Historically, conventional treatments for sarcomatoid RCCs (sRCCs) have shown little efficacy, and median survival is commonly 6–13 months. Despite being first described in 1968, the mechanisms driving sarcomatoid dedifferentiation remain poorly understood, and information and treatment options available to physicians and patients are limited. When diagnosed at an early stage, surgical intervention remains the treatment of choice. However, preoperative identification through routine imaging or biopsy is unreliable and most patients present with advanced disease and systemic symptoms. For these patients, the role of cytoreductive nephrectomy is disputed. The expansion of immunotherapies approved for RCCs has generated a search for biomarkers that might be indicative of treatment response in sRCCs, although a proven effective systemic agent remains elusive. PDL1 expression is increased in sarcomatoid dedifferentiated renal tumours, which suggests that patients with sRCCs could benefit from PD1 and/or PDL1 immune checkpoint blockade therapy. Treatment outcomes for sarcomatoid tumours have remained relatively consistent compared with other RCCs, but further investigation of the tumour–immune cell microenvironment might yield insights into further therapeutic possibilities.

In this Review, Blum et al. summarize the current knowledge on sarcomatoid renal cell carcinoma, a diagnosis characterized by the presence of sarcomatoid dedifferentiation and a poor prognosis. They discuss the origin, presentation, molecular biology and treatment of this disease.

Sarcomatoid dedifferentiation is not considered to be a unique histological subtype of renal cell carcinomas (RCCs); rather, it can be present within any subtype of RCCs.

Sarcomatoid dedifferentiation appears in ~4% of all RCCs, but is present in ~20% of all metastatic RCCs. According to WHO guidelines, any RCC with sarcomatoid dedifferentiation is a WHO–International Society of Urological Pathology grade 4 lesion.

Sarcomatoid dedifferentiation is often heterogeneously present within RCCs, making routine imaging and biopsy unreliable for preoperative detection. Surgical resection for localized disease is the standard of care, with subsequent close monitoring of patients following surgery.

In patients with metastatic disease, conventional therapies such as surgery and systemic agents have been ineffective and overall 5-year survival remains at 23.5–33%.

Previous genomic analyses have failed to identify definitive mutational drivers of disease. However, sarcomatoid RCCs (sRCCs) have been shown to have higher PD1 and PDL1 expression than other subtypes of RCCs. Newer combinations of immune checkpoint inhibitor immunotherapies could yield improved responses and outcomes.

Studies investigating sRCCs are limited by patient numbers owing to the low incidence of sRCCs and their advanced stage at presentation. Multi-institutional efforts to establish a consensus on treatment recommendations based on highly powered data are essential.

How Dysregulated Ion Channels and Transporters Take a Hand in Esophageal, Liver, and Colorectal Cancer

Over the last two decades, the understanding of how dysregulated ion channels and transporters are involved in carcinogenesis and tumor growth and progression, including invasiveness and metastasis, has been increasing exponentially. The present review specifies virtually all ion channels and transporters whose faulty expression or regulation contributes to esophageal, hepatocellular, and colorectal cancer. The variety reaches from Ca²⁺, K⁺, Na⁺, and Cl^- channels over divalent metal transporters, Na⁺ or Cl^- coupled Ca²⁺, HCO₃^- and H⁺ exchangers to monocarboxylate carriers and organic anion and cation transporters. In several cases, the underlying mechanisms by which these ion channels/transporters are interwoven with malignancies have been fully or at least partially unveiled. Ca²⁺, Akt/NF-κB, and Ca²⁺- or pH-dependent Wnt/β-catenin signaling emerge as cross points through which ion channels/transporters interfere with gene expression, modulate cell proliferation, trigger epithelial-to-mesenchymal transition, and promote cell motility and metastasis. Also miRs, lncRNAs, and DNA methylation represent potential links between the misexpression of genes encoding for ion channels/transporters, their malfunctioning, and cancer. The knowledge of all these molecular interactions has provided the basis for therapeutic strategies and approaches, some of which will be broached in this review.

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.

A Comprehensive Risk Assessment Model for Ovarian Cancer Patients with Phospho-STAT3 and IL-31 as Immune Infiltration Relevant Genes

Introduction

Ovarian carcinoma is a malignant tumor with a high mortality rate and a lack of effective treatment options for patients at advanced stages. For improving outcomes and helping patients with poor prognosis, choose a suitable therapy and an excellent risk assessment model and new treatment options are needed.

Materials and Methods

Ovarian cancer gene expression profile of GSE32062 was downloaded from the NCBI GEO database for screening differentially expressed genes (DEGs) between well and poor prognosis groups using limma package in R (version 3.4.1). Prognosis-related genes and clinical prognostic factors were obtained from univariate and multivariate Cox regression analyses, and a comprehensive risk assessment model was constructed using a Pathway Dysregulation Score (PDS) matrix, Cox-Proportional Hazards (Cox-PH) regression, as well as L1-least absolute shrinkage and selection operator (L1-LASSO) penalization. Then, significant DEGs were converted to pathways and optimal prognosis-related pathways were screened. Finally, risk prediction models based on pathways, genes involved in pathways, and comprehensive clinical risk factors with pathways were built. Their prognostic functions were assessed in verification sets. Besides, genes involved in immune-pathways were checked for immune infiltration using immunohistochemistry.

Results

A superior risk assessment model involving 9 optimal combinations of pathways and one clinical factor was constructed. The pathway-based model was found to be superior to the gene-based model. Phospho-STAT3 (from JAK-STAT signaling pathway) and IL-31 (from DEGs) were found to be related to immune infiltration.

Conclusion

We have generated a comprehensive risk assessment model consisting of a clinical risk factor and pathways that showed a possible bright foreground. The set of significant pathways might play as a better prognosis model which is more accurate and applicable than the DEG set. Besides, p-STAT3 and IL-31 showing correlation to immune infiltration of ovarian cancer tissues may be potential therapeutic targets for treating ovarian cancers.

The Role of TGF-β and Its Receptors in Gastrointestinal Cancers

Early detection of gastrointestinal tumors improves patient survival. However, patients with these tumors are typically diagnosed at an advanced stage and have poor prognosis. The incidence and mortality of gastrointestinal cancers, including esophageal, gastric, liver, colorectal, and pancreatic cancers, are increasing worldwide. Novel diagnostic and therapeutic agents are required to improve patient survival and quality of life. The tumor microenvironment, which contains nontumor cells, signaling molecules such as growth factors and cytokines, and extracellular matrix proteins, plays a critical role in cancer cell proliferation, invasion, and metastasis. Transforming growth factor beta (TGF-β) signaling has dual roles in gastrointestinal tumor development and progression as both a tumor suppressor and tumor promoter. Here, we review the dynamic roles of TGF-β and its receptors in gastrointestinal tumors and provide evidence that targeting TGF-β signaling may be an effective therapeutic strategy.

CaDrA: A Computational Framework for Performing Candidate Driver Analyses Using Genomic Features

The identification of genetic alteration combinations as drivers of a given phenotypic outcome, such as drug sensitivity, gene or protein expression, and pathway activity, is a challenging task that is essential to gaining new biological insights and to discovering therapeutic targets. Existing methods designed to predict complementary drivers of such outcomes lack analytical flexibility, including the support for joint analyses of multiple genomic alteration types, such as somatic mutations and copy number alterations, multiple scoring functions, and rigorous significance and reproducibility testing procedures. To address these limitations, we developed Candidate Driver Analysis or CaDrA, an integrative framework that implements a step-wise heuristic search approach to identify functionally relevant subsets of genomic features that, together, are maximally associated with a specific outcome of interest. We show CaDrA's overall high sensitivity and specificity for typically sized multi-omic datasets using simulated data, and demonstrate CaDrA's ability to identify known mutations linked with sensitivity of cancer cells to drug treatment using data from the Cancer Cell Line Encyclopedia (CCLE). We further apply CaDrA to identify novel regulators of oncogenic activity mediated by Hippo signaling pathway effectors YAP and TAZ in primary breast cancer tumors using data from The Cancer Genome Atlas (TCGA), which we functionally validate in vitro. Finally, we use pan-cancer TCGA protein expression data to show the high reproducibility of CaDrA's search procedure. Collectively, this work demonstrates the utility of our framework for supporting the fast querying of large, publicly available multi-omics datasets, including but not limited to TCGA and CCLE, for potential drivers of a given target profile of interest.

The potassium channel KCa3.1 promotes cell proliferation by activating SKP2 and metastasis through the EMT pathway in hepatocellular carcinoma

The intermediate conductance calcium-activated potassium channel (KCa3.1) plays an important role in maintaining intracellular calcium homeostasis and is involved in the tumorigenesis of many human cancers. However, it is unknown whether KCa3.1 plays a role in the genesis of hepatocellular carcinoma (HCC), one of the most common malignant tumors worldwide with a very poor prognosis. In our study, we found that the expression of KCa3.1 was significantly elevated in poorly differentiated HCC tissues compared to adjacent noncancerous tissues. In vitro and in vivo experiments showed that KCa3.1 could promote cell proliferation, migration, and invasion of HCC. Mechanistically, KCa3.1 promoted cell cycle progression and migration and invasion of HCC cells by activating S-phase protein kinase 2 (SKP2) to trigger the degradation of p21 and p27 and targeting Reelin (RELN) to induce epithelial-mesenchymal transition (EMT), respectively. Taken together, our results demonstrate that KCa3.1 plays an important role in the genesis and progression of HCC, implying that it might be a promising therapeutic target in HCC.

TGFβ1-induced cell motility but not cell proliferation is mediated through Cten in colorectal cancer

Cten (C-terminal tensin-like) is a member of the tensin protein family found in complex with integrins at focal adhesions. It promotes epithelial-mesenchymal transition (EMT) and cell motility. The precise mechanisms regulating Cten are unknown, although we and others have shown that Cten could be under the regulation of several cytokines and growth factors. Since transforming growth factor beta 1 (TGF-β1) regulates integrin function and promotes EMT/cell motility, we were prompted to investigate whether TGF-β1 induces EMT and cell motility through Cten signalling in colorectal cancer. TGF-β1 signalling was modulated by either stimulation with TGF-β1 or knockdown of TGF-β1 in the CRC cell lines SW620 and HCT116. The effect of this modulation on expression of Cten, EMT markers and on cellular function was tested. The role of Cten as a direct mediator of TGF-β1 signalling was investigated in a CRC cell line in which the Cten gene had been deleted (SW620^ΔCten ). When TGF-β1 was stimulated or inhibited, this resulted in, respectively, upregulation and downregulation of Cten expression and EMT markers (Snail, Rock, N-cadherin, Src). Cell migration and cell invasion were significantly increased following TGF-β1 stimulation and lost by TGF-β1 knockdown. TGF-β1 stimulation of the SW620^ΔCten cell line resulted in selective loss of the effect of TGF-β1 signalling pathway on EMT and cell motility while the stimulatory effect on cell proliferation was retained. These data suggested Cten may play an essential role in mediating TGF-β1-induced EMT and cell motility and may therefore play a role in metastasis in CRC.

TGF-β1 promotes cell migration in hepatocellular carcinoma by suppressing reelin expression

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is a leading cause of worldwide cancer mortality. Intrahepatic dissemination and extrahepatic metastasis are key factors in malignant growth of HCC. Reducing HCC-associated metastasis is critically dependent on uncovering molecular signaling pathways that promote HCC metastasis. In this study, we explored the effect of TGF-β1 and RELN on cell migration, and the relationship between TGF-β1 and RELN in HCC cells. The data presented that TGF-β1 and RELN showed an opposite expression pattern, and either increased expression of TGF-β1 or decreased expression of RELN increased HCC cell migration ability. We also found TGF-β1 enhanced cell migration ability was through repressing RELN expression, as overexpression of RELN impaired TGF-β1 enhanced cell migration. Our work revealed the relationship between TGF-β1 and RELN and uncovered the important role of RELN in suppressing cell migration in HCC cells.

The calcium channel proteins ORAI3 and STIM1 mediate TGF-β induced Snai1 expression

Calcium influx into cells via plasma membrane protein channels is tightly regulated to maintain cellular homeostasis. Calcium channel proteins in the plasma membrane and endoplasmic reticulum have been linked to cancer, specifically during the epithelial-mesenchymal transition (EMT), a cell state transition process implicated in both cancer cell migration and drug resistance. The transcription factor SNAI1 (SNAIL) is upregulated during EMT and is responsible for gene expression changes associated with EMT, but the calcium channels required for Snai1 expression remain unknown. In this study, we show that blocking store-operated calcium entry (SOCE) with 2-aminoethoxydiphenylborane (2APB) reduces cell migration but, paradoxically, increases the level of TGF-β dependent Snai1 gene activation. We determined that this increased Snai1 transcription involves signaling through the AKT pathway and subsequent binding of NF-κB (p65) at the Snai1 promoter in response to TGF-β. We also demonstrated that the calcium channel protein ORAI3 and the stromal interaction molecule 1 (STIM1) are required for TGF-β dependent Snai1 transcription. These results suggest that calcium channels differentially regulate cell migration and Snai1 transcription, indicating that each of these steps could be targeted to ensure complete blockade of cancer progression.

FOXC2 and CLIP4 : a potential biomarker for synchronous metastasis of ≤7-cm clear cell renal cell carcinomas

Renal cell carcinomas (RCC) smaller than 7-cm are heterogeneous and exhibit metastatic potential in approximately 15% of cases. Although large-scale characterization of mutations in clear cell RCC (ccRCC), the most common RCC subtype, has been established, the genetic alterations related to ≤7-cm ccRCCs undergoing synchronous metastasis are poorly understood. To discover biomarkers that can be used to estimate the risk of synchronous metastasis in these ccRCC patients, we performed whole exome sequencing on the formalin-fixed paraffin-embedded (FFPE) samples of 10 ccRCC patients with ≤7-cm tumors and synchronous metastasis and expanded our study using The Cancer Genome Atlas (TCGA) ccRCC dataset (n = 201). Recurrent mutations were selected according to functional prediction and statistical significance. Mutations in three candidate genes, RELN (1 out of 10), FOXC2 (1 out of 10), and CLIP4 (2 out of 10) were found in expanded analysis using a TCGA cohort. Furthermore, siRNA-mediated target gene knockdown (FOXC2 and CLIP4) and overexpression (RELN) assays showed that FOXC2 and CLIP4 significantly increased cell migration and viability in ccRCCs. Our study demonstrated that FOXC2 and CLIP4 activity correlates to the presence of ≤7-cm ccRCCs with synchronous metastasis and may be potential molecular predictors of synchronous metastasis of ≤7-cm ccRCCs.

Sarcomatoid Renal Cell Carcinoma: The Apple Doesn't Fall Far from the Tree

The most comprehensive sequencing effort of sarcomatoid renal cell carcinoma (sRCC) to date reinforces the notion that the sarcomatoid component is closely related to the epithelial component of the cancer. This work also challenges the notion that sRCC evolves from low-grade RCC and identifies potential mediators of sarcomatoid differentiation. Clin Cancer Res; 23(21); 6381-3. ©2017 AACRSee related article by Wang et al., p. 6686.

Reelin promotes adhesion of multiple myeloma cells to bone marrow stromal cells via integrin β1 signaling

The close interaction between tumor cells and bone marrow stromal cells plays a crucial role in the tumorigenesis of multiple myeloma (MM). Reelin, an extracellular matrix protein, is found expressed in myeloma cells and is negatively associated with prognosis. We examined the role of Reelin in myeloma cell adhesion to bone marrow stromal cells and the signaling pathways involved. The results revealed that Reelin promoted the adhesion of myeloma cells to HS-5, a bone marrow stromal cell line, via the activation of β1 integrin. The resulting phosphorylation of focal adhesion kinase (FAK) led to the activation of Syk/STAT3 and Akt. Reelin's high affinity receptor ApoER2 indirectly modulated the adhesion of myeloma cells by promoting Reelin expression via Sp1. These findings indicate an important role for Reelin/integrin-β1-induced myeloma cell adhesion to bone marrow stromal cells and highlight the therapeutic potential of targeting Reelin/integrin/FAK axis.

RNA sequencing-based cell proliferation analysis across 19 cancers identifies a subset of proliferation-informative cancers with a common survival signature

Despite advances in cancer diagnosis and treatment strategies, robust prognostic signatures remain elusive in most cancers. Cell proliferation has long been recognized as a prognostic marker in cancer, but the generation of comprehensive, publicly available datasets allows examination of the links between cell proliferation and cancer characteristics such as mutation rate, stage, and patient outcomes. Here we explore the role of cell proliferation across 19 cancers (n = 6,581 patients) by using tissue-based RNA sequencing data from The Cancer Genome Atlas Project and calculating a 'proliferative index' derived from gene expression associated with Proliferating Cell Nuclear Antigen (PCNA) levels. This proliferative index is significantly associated with patient survival (Cox, p-value < 0.05) in 7 of 19 cancers, which we have defined as "proliferation-informative cancers" (PICs). In PICs, the proliferative index is strongly correlated with tumor stage and nodal invasion. PICs demonstrate reduced baseline expression of proliferation machinery relative to non-PICs. Additionally, we find the proliferative index is significantly associated with gross somatic mutation burden (Spearman, p = 1.76 x 10-23) as well as with mutations in individual driver genes. This analysis provides a comprehensive characterization of tumor proliferation indices and their association with disease progression and prognosis in multiple cancer types and highlights specific cancers that may be particularly susceptible to improved targeting of this classic cancer hallmark.

Extracellular matrix protein Reelin promotes myeloma progression by facilitating tumor cell proliferation and glycolysis

Reelin is an extracellular matrix protein that is crucial for neuron migration, adhesion, and positioning. We examined the expression of Reelin in a large cohort of multiple myeloma patients recorded in Gene Expression Omnibus (GEO) database and used over-expression and siRNA knockdown of Reelin to investigate the role of Reelin in myeloma cell growth. We find that Reelin expression is negatively associated with myeloma prognosis. Reelin promotes myeloma cell proliferation in vitro as well as in vivo. The Warburg effect, evidenced by increased glucose uptake and lactate production, is also enhanced in Reelin-expressing cells. The activation of FAK/Syk/Akt/mTOR and STAT3 pathways contributes to Reelin-induced cancer cell growth and metabolic reprogramming. Our findings further reveal that activated Akt and STAT3 pathways induce the upregulation of HIF1α and its downstream targets (LDHA and PDK1), leading to increased glycolysis in myeloma cells. Together, our results demonstrate the critical contributions of Reelin to myeloma growth and metabolism. It presents an opportunity for myeloma therapeutic intervention by inhibiting Reelin and its signaling pathways.

Astrocyte-induced Reelin expression drives proliferation of Her2+ breast cancer metastases

Breast cancer metastasis to the brain develops after a clinical latency of years to even decades, suggesting that colonization of the brain is the most challenging step of the metastatic cascade. However, the underlying mechanisms used by breast cancer cells to successfully colonize the brain's microenvironment remain elusive. Reelin is an archetypal extracellular glycoprotein that regulates migration, proliferation, and lamination of neurons. It is epigenetically silenced in various cancers, and its expression in multiple myelomas is linked to poor patient survival. We found that Reelin expression was low in primary breast cancer tissue. However, its expression was significantly higher in Her2⁺ breast cancers metastasizing to the brain. In particular, Reelin was highly expressed in the tumor periphery adjacent to surrounding astrocytes. This augmented Reelin expression was seen in Her2⁺ metastases, but not in triple negative (TN) primary tumors or in TN breast to brain metastasis cells co-cultured with astrocytes. Furthermore, the elevated expression was sustained in Her2⁺ cells grown in the presence of the DNA methyltransferase inhibitor 5-azacytidine, indicating epigenetic regulation of Reelin expression. The relative growth and rate of spheroids formation derived from Her2⁺ primary and BBM cells co-cultured with astrocytes were higher than those of TN primary and BBM cells, and knockdown of both Reelin and Her2 suppressed the astrocyte-induced growth and spheroid forming ability of Her2⁺ cells. Collectively, our results indicate that within the neural niche, astrocytes epigenetically regulate Reelin expression and its interaction with Her2 leading to increased proliferation and survival fitness.

Reelin promotes the adhesion and drug resistance of multiple myeloma cells via integrin β1 signaling and STAT3

Reelin is an extracellular matrix (ECM) protein that is essential for neuron migration and positioning. The expression of reelin in multiple myeloma (MM) cells and its association with cell adhesion and survival were investigated. Overexpression, siRNA knockdown, and the addition of recombinant protein of reelin were used to examine the function of reelin in MM cells. Clinically, high expression of reelin was negatively associated with progression-free survival and overall survival. Functionally, reelin promoted the adhesion of MM cells to fibronectin via activation of α5β1 integrin. The resulting phosphorylation of Focal Adhesion Kinase (FAK) led to the activation of Src/Syk/STAT3 and Akt, crucial signaling molecules involved in enhancing cell adhesion and protecting cells from drug-induced cell apoptosis. These findings indicate reelin's important role in the activation of integrin-β1 and STAT3/Akt pathways in multiple myeloma and highlight the therapeutic potential of targeting reelin/integrin/FAK axis.

Nonneuronal roles for the reelin signaling pathway

The reelin signaling pathway has been established as an important regulator of cell migration during development of the central nervous system, and disruptions in reelin signaling alter the positioning of many types of neurons. Reelin is a large extracellular matrix glycoprotein and governs cell migration through activation of multiple intracellular signaling events by means of the receptors ApoE receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR), and the intracellular adaptor protein Disabled-1 (Dab1). Earlier studies reported expression of reelin in nonneuronal tissues, but the functions of this signaling pathway outside of the nervous system have not been studied until recently. A large body of evidence now suggests that reelin functions during development and disease of multiple nonneuronal tissues. This review addresses recent advances in the field of nonneuronal reelin signaling. Developmental Dynamics 246:217-226, 2017. © 2016 Wiley Periodicals, Inc.

DNA methylation profile of triple negative breast cancer-specific genes comparing lymph node positive patients to lymph node negative patients

Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype with no targeted treatment available. Our previous study identified 38 TNBC-specific genes with altered expression comparing tumour to normal samples. This study aimed to establish whether DNA methylation contributed to these expression changes in the same cohort as well as disease progression from primary breast tumour to lymph node metastasis associated with changes in the epigenome. We obtained DNA from 23 primary TNBC samples, 12 matched lymph node metastases, and 11 matched normal adjacent tissues and assayed for differential methylation profiles using Illumina HumanMethylation450 BeadChips. The results were validated in an independent cohort of 70 primary TNBC samples. The expression of 16/38 TNBC-specific genes was associated with alteration in DNA methylation. Novel methylation changes between primary tumours and lymph node metastases, as well as those associated with survival were identified. Altered methylation of 18 genes associated with lymph node metastasis were identified and validated. This study reveals the important role DNA methylation plays in altered gene expression of TNBC-specific genes and lymph node metastases. The novel insights into progression of TNBC to secondary disease may provide potential prognostic indicators for this hard-to-treat breast cancer subtype.

Reelin-Dab1 signaling system in human colorectal cancer

Reelin is an extracellular matrix protein that plays a critical role in neuronal migration. Here we show that the mucosa of human colon expresses reelin, its receptors ApoER2 and VLDLR, and its effector protein Dab1. Immunohistochemical analyses reveal that reelin expression is restricted to pericryptal myofibroblasts; Dab1 is detected at myofibroblasts, the apical domain of surface epithelial and crypt cells, and a strong linear staining is observed at the basement membrane; VLDLR and ApoER2 are in the cytoplasm of surface epithelium and myofibroblasts, and VLDLR is also detected in the cytoplasm of the crypt cells. Human colorectal cancer downregulates reelin without change in vimentin or N-cadherin mRNA levels. Decreased Reelin mRNA expression is accompanied by decreased HIC1 mRNA levels, increased mRNA levels of ApoER2 and DNMT1, increased reelin hypermethylation and no change in either Cask or TGF-β1 mRNAs, suggesting that reelin repression results from a DNMT1-mediated hypermethylation of the reelin gene promoter. Decreased HIC1 expression may repress reelin transcription via increasing ApoER2 transcription. We conclude that the mucosa of human colon expresses the reelin-Dab1 signaling system and that reelin is repressed in colorectal cancer before epithelial-mesenchymal transition has occurred. The significant down-regulation of reelin expression makes this gene a promising biomarker for colorectal cancers. © 2016 Wiley Periodicals, Inc.

MicroRNA-17/20a impedes migration and invasion via TGF-β/ITGB6 pathway in esophageal squamous cell carcinoma

Patients with esophageal squamous cell carcinoma (ESCC) have an overall poor prognosis due to invasion and metastasis. Although it has been studied extensively, the metastatic mechanisms of ESCC remains largely unclear. Here, we evaluated microRNA expression in ESCC cell sublines with distinct motility and found that microRNA-17 and microRNA-20a (miR-17/20a) dramatically impeded cell migration and invasion of ESCC in vitro and decreased pulmonary arrest in vivo. Furthermore, we identified that TGF-β receptor 2 (TGFBR2) and Smad anchor for receptor activation (SARA) served as genuine miR-17/20a targets, which are both implicated in TGF-β pathway. TGF-β treatment promoted the motility of ESCC cells, and miR-17/20a could attenuate the activation of TGF-β pathway by weakening the phosphorylation of Smad2/3 to reduce the expression of ITGB6, which was crucial in migration and invasion of ESCC cells. Moreover, evaluation of ESCC specimens revealed a close correlation between miR-17/20a, TGFBR2, SARA and lymph node metastasis. Together, our findings demonstrate that miR-17/20a suppresses cell migration and invasion of ESCC by modulating TGF-β/ITGB6 pathway, suggesting a promising strategy for diagnosis and therapy of ESCC invasion and metastasis.

RAS signalling through PI3-Kinase controls cell migration via modulation of Reelin expression

RAS signalling through phosphoinositide 3-kinase (PI3-Kinase) has been shown to have an essential role in tumour initiation and maintenance. RAS also regulates cell motility and tumour invasiveness, but the role of direct RAS binding to PI3-Kinase in this remains uncertain. Here, we provide evidence that disruption of RAS interaction with PI3-Kinase p110α decreases cell motility and prevents activation of Rac GTPase. Analysis of gene expression in cells lacking RAS interaction with p110α reveals increased levels of the extracellular matrix glycoprotein Reelin and activation of its downstream pathway resulting in upregulation of E-cadherin expression. Induction of the Reelin/E-cadherin axis is also observed in Kras mutant lung tumours that are regressing due to blockade of RAS interaction with PI3-Kinase. Furthermore, loss of Reelin correlates with decreased survival of lung and breast cancer patients. Reelin thus plays a role in restraining RAS and PI3-kinase promotion of cell motility and potentially tumour metastasis.

Comparative analysis of primary tumour and matched metastases in colorectal cancer patients: evaluation of concordance between genomic and transcriptional profiles

PURPOSE

Focal and temporal tumour heterogeneity can represent a major challenge for biology-guided therapies. This study proposes to investigative molecular discrepancies between primary colorectal cancer (CRC) samples and matched metastases.

EXPERIMENTAL DESIGN

Surgical samples from primary and matched metastatic tissues from 13 CRC patients along with their adjacent normal tissue were evaluated. A mutational analysis was performed using a targeted Next Generation Sequencing assay (Foundation Medicine) with a focus on known recurrent somatic mutations as surrogate of key oncogenic events. Gene expression analysis was also performed to investigate transcriptional discrepancies.

RESULTS

Among the 26 samples, 191 mutations were identified including mutations in APC (13 pts), TP53 (11 pts), and KRAS (7 pts). Global concordance rate for mutations was 78% between primary and metastatic tumours and raised to 90% for 12 known recurrent mutations in CRC. Differential gene expression analysis revealed a low number of significantly variant transcripts between primary and metastatic tumours once the tissue effect was taken into account. Only two pathways (ST_ADRENERGIC, PID_REELINPATHWAY) were differentially up-regulated in metastases among 17 variant pathways. A common profile in primary and metastatic tumours revealed conserved pathways mostly involved in cell cycle regulation. Only two pathways were significantly down regulated compared to normal control, including regulation of autophagy (KEGG_REGULATION_OF_AUTOPHAGY).

CONCLUSION

These results suggest that profiles of primary tumour can identify key alterations present in matched CRC metastases at first metastatic progression. Gene expression analysis identified mainly conserved pathways between primary tumour and matched liver metastases.

Peritoneal tumor carcinomatosis: pharmacological targeting with hyaluronan-based bioconjugates overcomes therapeutic indications of current drugs

Peritoneal carcinomatosis still lacks reliable therapeutic options. We aimed at testing a drug delivery strategy allowing a controlled release of cytotoxic molecules and selective targeting of tumor cells. We comparatively assessed the efficacy of a loco-regional intraperitoneal treatment in immunocompromised mice with bioconjugates formed by chemical linking of paclitaxel or SN-38 to hyaluronan, against three models of peritoneal carcinomatosis derived from human colorectal, gastric and esophageal tumor cell xenografts. In vitro, bioconjugates were selectively internalized through mechanisms largely dependent on interaction with the CD44 receptor and caveolin-mediated endocytosis, which led to accumulation of compounds into lysosomes of tumor cells. Moreover, they inhibited tumor growth comparably to free drugs. In vivo, efficacy of bioconjugates or free drugs against luciferase-transduced tumor cells was assessed by bioluminescence optical imaging, and by recording mice survival. The intraperitoneal administration of bioconjugates in tumor-bearing mice exerted overlapping or improved therapeutic efficacy compared with unconjugated drugs. Overall, drug conjugation to hyaluronan significantly improved the profiles of in vivo tolerability and widened the field of application of existing drugs, over their formal approval or current use. Therefore, this approach can be envisaged as a promising therapeutic strategy for loco-regional treatment of peritoneal carcinomatosis.

Aberrant gene expression in mucosa adjacent to tumor reveals a molecular crosstalk in colon cancer

Background

A colorectal tumor is not an isolated entity growing in a restricted location of the body. The patient’s gut environment constitutes the framework where the tumor evolves and this relationship promotes and includes a complex and tight correlation of the tumor with inflammation, blood vessels formation, nutrition, and gut microbiome composition. The tumor influence in the environment could both promote an anti-tumor or a pro-tumor response.

Methods

A set of 98 paired adjacent mucosa and tumor tissues from colorectal cancer (CRC) patients and 50 colon mucosa from healthy donors (246 samples in total) were included in this work. RNA extracted from each sample was hybridized in Affymetrix chips Human Genome U219. Functional relationships between genes were inferred by means of systems biology using both transcriptional regulation networks (ARACNe algorithm) and protein-protein interaction networks (BIANA software).

Results

Here we report a transcriptomic analysis revealing a number of genes activated in adjacent mucosa from CRC patients, not activated in mucosa from healthy donors. A functional analysis of these genes suggested that this active reaction of the adjacent mucosa was related to the presence of the tumor. Transcriptional and protein-interaction networks were used to further elucidate this response of normal gut in front of the tumor, revealing a crosstalk between proteins secreted by the tumor and receptors activated in the adjacent colon tissue; and vice versa. Remarkably, Slit family of proteins activated ROBO receptors in tumor whereas tumor-secreted proteins transduced a cellular signal finally activating AP-1 in adjacent tissue.

Conclusions

The systems-level approach provides new insights into the micro-ecology of colorectal tumorogenesis. Disrupting this intricate molecular network of cell-cell communication and pro-inflammatory microenvironment could be a therapeutic target in CRC patients.

Human breast cancer metastases to the brain display GABAergic properties in the neural niche

Dispersion of tumors throughout the body is a neoplastic process responsible for the vast majority of deaths from cancer. Despite disseminating to distant organs as malignant scouts, most tumor cells fail to remain viable after their arrival. The physiologic microenvironment of the brain must become a tumor-favorable microenvironment for successful metastatic colonization by circulating breast cancer cells. Bidirectional interplay of breast cancer cells and native brain cells in metastasis is poorly understood and rarely studied. We had the rare opportunity to investigate uncommonly available specimens of matched fresh breast-to-brain metastases tissue and derived cells from patients undergoing neurosurgical resection. We hypothesized that, to metastasize, breast cancers may escape their normative genetic constraints by accommodating and coinhabiting the neural niche. This acquisition or expression of brain-like properties by breast cancer cells could be a malignant adaptation required for brain colonization. Indeed, we found breast-to-brain metastatic tissue and cells displayed a GABAergic phenotype similar to that of neuronal cells. The GABAA receptor, GABA transporter, GABA transaminase, parvalbumin, and reelin were all highly expressed in breast cancer metastases to the brain. Proliferative advantage was conferred by the ability of breast-to-brain metastases to take up and catabolize GABA into succinate with the resultant formation of NADH as a biosynthetic source through the GABA shunt. The results suggest that breast cancers exhibit neural characteristics when occupying the brain microenvironment and co-opt GABA as an oncometabolite.

Transforming growth factor beta 1 induces CXCL16 and leukemia inhibitory factor expression in osteoclasts to modulate migration of osteoblast progenitors

The processes of bone resorption and bone formation are tightly coupled in young adults, which is crucial to maintenance of bone integrity. We have documented that osteoclasts secrete chemotactic agents to recruit osteoblast lineage cells, contributing to coupling. Bone formation subsequent to bone resorption becomes uncoupled with aging, resulting in significant bone loss. During bone resorption, osteoclasts release and activate transforming growth factor beta 1 (TGF-β1) from the bone matrix; thus, elevated bone resorption increases the level of active TGF-β in the local environment during aging. In this study, we examined the influences of TGF-β1 on the ability of osteoclasts to recruit osteoblasts. TGF-β1 increased osteoclast expression of the chemokine CXCL16 to promote osteoblast migration. TGF-β1 also directly stimulated osteoblast migration; however, this direct response was blocked by conditioned medium from TGF-β1-treated osteoclasts due to the presence of leukemia inhibitory factor (LIF) in the medium. CXCL16 and LIF expression was dependent on TGF-β1 activation of Smad2 and Smad3. These results establish that TGF-β1 induces CXCL16 and LIF production in osteoclasts, which modulate recruitment of osteoblasts to restore the bone lost during the resorptive phase of bone turnover.

Interdigital cell death in the embryonic limb is associated with depletion of Reelin in the extracellular matrix

Interdigital cell death is a physiological regression process responsible for sculpturing the digits in the embryonic vertebrate limb. Changes in the intensity of this degenerative process account for the different patterns of interdigital webbing among vertebrate species. Here, we show that Reelin is present in the extracellular matrix of the interdigital mesoderm of chick and mouse embryos during the developmental stages of digit formation. Reelin is a large extracellular glycoprotein which has important functions in the developing nervous system, including neuronal survival; however, the significance of Reelin in other systems has received very little attention. We show that reelin expression becomes intensely downregulated in both the chick and mouse interdigits preceding the establishment of the areas of interdigital cell death. Furthermore, fibroblast growth factors, which are cell survival signals for the interdigital mesoderm, intensely upregulated reelin expression, while BMPs, which are proapototic signals, downregulate its expression in the interdigit. Gene silencing experiments of reelin gene or its intracellular effector Dab-1 confirmed the implication of Reelin signaling as a survival factor for the limb undifferentiated mesoderm. We found that Reelin activates canonical survival pathways in the limb mesoderm involving protein kinase B and focal adhesion kinase. Our findings support that Reelin plays a role in interdigital cell death, and suggests that anoikis (apoptosis secondary to loss of cell adhesion) may be involved in this process.

Retinoic acid suppresses the adhesion and migration of human retinal pigment epithelial cells

The study was designed to better understand how retinoic acid (RA) influenced the migration and invasion abilities of retinal pigment epithelial cells (RPE) in vitro and how the related genes of the extracellular matrix (ECM) were expressed. The inhibition effects of RA on proliferative vitreoretinopathy (PVR) formation induced by RPE cells were studied in rabbits. Wound healing and Boyden chamber assays were used to show the abilities of migration and invasion of RPE. Microarray, real-time quantitative PCR (qPCR) and Western blotting showed how RA regulated the ECM genes. RA (10(-5) M) significantly (P < 0.05) inhibited PVR membrane and traction retinal detachment formation (80%). Moreover, RA treatment significantly inhibited the migration (80%) and invasion (65%) behaviors of human RPE cells (P < 0.05) by wound healing and Boyden chamber assays, respectively. Microarray and q PCR analysis showed RA treatment did inhibit the motility of human RPE cells by inhibition of metalloproteinases (MMP) 1, 2, 9, fibronectin-1, transforming growth factor beta, thrombospondin-1, tenascin C, most collagen, integrin, laminin molecules and along enhancing E-cadherin and MMP3 genes expression. And Western blotting indicated the coincident results on protein level of MMP1, 2, 3, 9, 14; fibronectin-1; integrinαM, β2 and E-cadherin. In conclusions, RA is a vital drug to inhibit the abilities of migration and invasion of RPE and to hamper the PVR formation by regulating some genes expression of ECM.

The therapeutic function of the chemokine RANTES on the H22 hepatoma ascites model

This study aimed at analyzing the therapeutic function of the chemokine RANTES on the H22 hepatoma ascites model and preliminarily explore the mechanism of RANTES in malignant ascites to provide an important reference for applying chemokines in anti-tumor therapy. The murine H22 hepatoma ascites model was used. Three treatment groups were analyzed: a RANTES treatment group, an IL-2 control group, and an NS control group. Two regimens of early treatment and late treatment were designed, and the therapeutic effect of RANTES on malignant ascites was studied by measuring changes in mouse body weight and abdominal circumference and observing the survival time. The expression of TNF-α, IFN-γ, TGF-β1, and MCP-1 in mouse ascites was detected by ELISA, and the chemotactic function of RANTES on B lymphocytes and T lymphocytes was analyzed by flow cytometry. In the early and late treatment regimens, RANTES could effectively inhibit the increase in mouse body weight and abdominal circumference in the murine H22 hepatoma ascites model. The secretion of TNF-α and IFN-γ, which had anti-tumor effects, was higher in the RANTES treatment group than in the control groups (P < 0.05), whereas the secretion of TGF-β1 and MCP-1, which promoted tumor growth, invasion, and metastasis, was lower than in the control groups (P < 0.05). RANTES had chemotactic effects on CD4(+) and CD8(+) T lymphocytes; therefore, the percentage of CD3, CD4, and CD8 in the mouse ascites in the RANTES treatment group was significantly higher than in the NS control and IL-2 treatment groups, and the CD4/CD8 ratio was also significantly higher. RANTES can effectively inhibit the increase in body weight and abdominal circumference and significantly extend survival time in mice in the H22 hepatoma ascites model.