Expression of lysyl oxidase is correlated with lymph node metastasis and poor prognosis in esophageal squamous cell carcinoma

RNA sequencing reveals the implication of the circRNA-associated ceRNA network in oesophageal squamous cell carcinoma

Circular RNAs (circRNAs) have attracted increasing attention in cancer research. However, there are few studies about the high-throughput sequencing for clinical cohorts focussing on the expression characteristics and regulatory networks of circRNAs in oesophageal squamous cell carcinoma (ESCC) until now. Present study aim to comprehensively recognize the functional and mechanistic patterns of circRNA through constructing a circRNA-related competing endogenous RNA (ceRNA) network in ESCC. Summarily, RNA high-throughput sequencing was adopted to assess the circRNA, miRNA and mRNA expression profiles in ESCC. Through bioinformatics methods, a circRNA-miRNA-mRNA coexpression network was constructed and hub genes was identified. Finally, cellular function experiments combined with bioinformatics analysis were conducted to verify the identified circRNA was involved in the progression of ESCC through ceRNA mechanism. In this study, we established a ceRNA regulatory network, including 5 circRNAs, 7 miRNAs and 197 target mRNAs, and 20 hub genes were screened and identified to exert important roles in the progression of ESCC. As a verification, hsa_circ_0002470 (circIFI6) was revealed to be highly expressed in ESCC and regulate the expression of hub genes by absorbing miR-497-5p and miR-195-5p through ceRNA mechanism. Our results further indicated that silencing of circIFI6 repressed proliferation and migration of ESCC cells, highlighting the tumour promotion effects of circIFI6 in ESCC. Collectively, our study contributes a new insight into the progression of ESCC from the perspective of the circRNA-miRNA-mRNA network, shedding light on the circRNA research in ESCC.

Comparison of Immunohistochemical Markers in Oral Submucous Fibrosis and Oral Submucous Fibrosis Transformed to Oral Squamous Cell Carcinoma-A Systematic Review and Meta-Analysis

The objective of the study was to compare the expression of immunohistochemical (IHC) markers of oral submucous fibrosis (OSMF) (non-transformed group) to those of oral squamous cell carcinoma (OSCC) transformed from OSMF (transformed group). The search for comparative cross-sectional studies was carried out in PubMed and Scopus abiding to the PICO criteria, where expression of IHC markers in OSMF were compared with that of OSCC transformed from OSMF. The cellular distribution, number of positive cases, staining intensity, and mean immunoreactive score (IRS) of each IHC marker were evaluated in both groups. A total of 14 studies were included in the systematic review, in which immunoexpression of 15 epithelial and 4 connective tissue biomarkers were evaluated. Expression of β1-integrin, OCT-3, CD1a, CD207, survivin, Dickkopf-1, COX-2, hTERT, CTGF, MDM2, Ki-67, and α-SMA were increased during transformation of OSMF to OSCC. Conversely, expression of PTEN and lysyl oxidase decreased during transformation of OSMF to OSCC. Expression of a group of epithelial markers, such as COX2, hTERT, CTGF, survivin, MDM2, and p53, was 38 times lower in the non-transformed group cases compared to transformed group cases (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Meta-analysis of all markers involved in cell metabolism/apoptosis, which included β1-integrin along with the above markers also suggested 42 times lower expression in the non-transformed group as compared to the transformed group (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Sub-group analyses on cytoplasmic and nuclear epithelial markers were inconclusive. Meta-analysis of connective tissue markers was also inconclusive. No publication bias was found. Instead of delving into numerous markers without a strong basis for their use, it is advisable to further study the markers identified in this study to explore their clinical utility.

LOX and Its Methylation Impact Prognosis of Diseases and Correlate with TAM Infiltration in ESCA

Background

ESCA is one of the digestive tract tumors with a high fatality. It is implicated in an intricate gene regulation process, but the pathogenesis remains ambiguous.

Methods

The study used the packages of Limma from R software to analyze DEGs of ESCA in the GEO database and TCGA database. We employed the DAVID website for enrichment analysis, and the string database constructed the PPI network. Hub genes were identified from ESCA DEGs with Cytoscape MCODE. We evaluated the clinical relevance of LOX expression and its DNA methylation in the cBioPortal database and explored the roles of LOX in ESCA immunity, especially immune cell infiltration levels and immune checkpoint expression, by immunedeconv package of R software.

Conclusions

The overexpression of LOX in ESCA is regulated by DNA hypomethylation; LOX overexpression or LOX hypomethylation can predict a worse prognosis in patients with ESCA. Besides, LOX may be involved in TIME regulation, promoting the infiltration levels and function of TAM. Hence, high LOX expression affected by DNA hypomethylation has an essential role in patients with ESCA, which may become an effective prognostic marker and therapeutic target.

Expression of LOX Suggests Poor Prognosis in Gastric Cancer

Background: Lysyl oxidase (LOX) is a key enzyme for the cross-linking of collagen and elastin in the extracellular matrix. This study evaluated the prognostic role of LOX in gastric cancer (GC) by analyzing the data of The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) dataset. Methods: The Wilcoxon rank-sum test was used to calculate the expression difference of LOX gene in gastric cancer and normal tissues. Western blot and immunohistochemical staining were used to evaluate the expression level of LOX protein in gastric cancer. Kaplan-Meier analysis was used to calculate the survival difference between the high expression group and the low expression group in gastric cancer. The relationship between statistical clinicopathological characteristics and LOX gene expression was analyzed by Wilcoxon or Kruskal-Wallis test and logistic regression. Univariate and multivariate Cox regression analysis was used to find independent risk factors affecting the prognosis of GC patients. Gene set enrichment analysis (GSEA) was used to screen the possible mechanisms of LOX and GC. The CIBERSORT calculation method was used to evaluate the distribution of tumor-infiltrating immune cell (TIC) abundance. Results: LOX is highly expressed in gastric cancer tissues and is significantly related to poor overall survival. Wilcoxon or Kruskal-Wallis test and Logistic regression analysis showed, LOX overexpression is significantly correlated with T-stage progression in gastric cancer. Multivariate Cox regression analysis on TCGA and GEO data found that LOX (all p < 0.05) is an independent factor for poor GC prognosis. GSEA showed that high LOX expression is related to ECM receptor interaction, cancer, Hedgehog, TGF-beta, JAK-STAT, MAPK, Wnt, and mTOR signaling pathways. The expression level of LOX affects the immune activity of the tumor microenvironment in gastric cancer. Conclusion: High expression of LOX is a potential molecular indicator for poor prognosis of gastric cancer.

Lysyl Oxidase Mechanisms to Mediate Gastrointestinal Cancer Progression

Background

Malignancy is a complex process resulting from different changes such as extracellular matrix (ECM) remodeling and stiffness. One of the important enzymes that contribute to ECM remodeling is lysyl oxidase (Lox) that is overexpressed in different types of human cancers. Because of the high prevalence and poor survival of gastrointestinal (GI) malignancies in this review, we discuss the association between Lox activity and the progression of GI cancers. Lox proteins are a group of extracellular enzymes that catalyzed the cross-linking of collagen and elastin, so they have important roles in the control of structure and homeostasis of ECM. Abnormal activation and expression of the Lox family of proteins lead to changes in the ECM toward increased rigidity and fibrosis. Stiffness of ECM can contribute to the pathogenesis of cancers.

Summary

Dysregulation of Lox expression is a factor in both fibrotic diseases and cancer. ECM stiffness by Lox overactivity creates a physical barrier against intratumoral concentration of chemotherapeutic drugs and facilitates cancer inflammation, angiogenesis, and metastasis.

Key Message

Because of the roles of Lox in GI cancers, development targeting Lox protein isotypes may be an appropriate strategy for treatment of GI cancers and improvement in survival of patients.

Increased expression of IFI16 predicts adverse prognosis in multiple myeloma

Multiple myeloma (MM) is a malignancy of terminally differentiated plasma cells and does not have sufficient prognostic indicators. Interferon gamma inducible protein 16 (IFI16) plays a crucial role in B-cell differentiation. Several studies have shown that IFI16 predicted prognosis in many cancers. However, the relationship between MM prognosis and IFI16 expression has not been studied. In our study, we analyzed the prognostic role of IFI16 expression and explored the possible mechanism in MM progression by using 4498 myeloma patients and 52 healthy donors from 13 independent gene expression omnibus (GEO) datasets. The IFI16 expression increased with myeloma progression, ISS stage, 1q21 amplification, and relapse (all P < 0.01). MM patients with higher IFI16 expression had shorter survival in six datasets (all P < 0.05). Furthermore, multivariate analysis indicated that enhanced IFI16 expression was an independent poor prognostic factor for EFS and OS (P = 0.007, 0.009, respectively). And PPI, GO, KEGG, and GSEA also confirmed that IFI16 promoted MM progression by participating in tumor-related pathways. In conclusion, our study confirmed that IFI16 was a poor prognostic biomarker in MM.

Significance of HIF-1α Expression and LOXL-2 Localization in Progression of Oral Squamous Cell Carcinoma

Backgroud: In the microenvironment of Oral Squamous Cell Carcinoma (OSCC), Hypoxia-inducible transcription factor 1 (HIF-1) is a very important chemical mediator in the microenvironment of OSCC through which cells respond to hypoxia. LOXL-2 participates in ECM remodelling, and also in regulating epithelial-to-mesenchymal transition, epithelial cell polarity and differentiation. Aim/material and methods: The present study was conducted on 90 histopathologically proven cases of OSCC to ascertain the role of HIF-1α and LOXL-2 in OSCC. Immunoexpression of both HIF-1α and LOXL-2 was analyzed both quantitatively and qualitatively and compared with tumor stage, nodal stage, clinical stage, and histological grade. Results: Tumor stages and nodal stages had significant correlation with HIF-1α expression and localization of LOXL-2 immunoexpression respectively. Conclusion: This is probably the first study to analyze LOXL-2 localization in OSCC. Alteration in the immunoexpression of LOXL-2 from nuclear to cytoplasmic and HIF-1α immunoexpression might be an important factor in progression of OSCC.

Targeting Lysyl Oxidase Family Meditated Matrix Cross-Linking as an Anti-Stromal Therapy in Solid Tumours

Simple Summary

To improve efficacy of solid cancer treatment, efforts have shifted towards targeting both the cancer cells and the surrounding tumour tissue they grow in. The lysyl oxidase (LOX) family of enzymes underpin the fibrotic remodeling of the tumour microenvironment to promote both cancer growth, spread throughout the body and modulate response to therapies. This review examines how the lysyl oxidase family is involved in tumour development, how they can be targeted, and their potential as diagnostic and prognostic biomarkers in solid tumours.

Abstract

The lysyl oxidase (LOX) family of enzymes are a major driver in the biogenesis of desmoplastic matrix at the primary tumour and secondary metastatic sites. With the increasing interest in and development of anti-stromal therapies aimed at improving clinical outcomes of cancer patients, the Lox family has emerged as a potentially powerful clinical target. This review examines how lysyl oxidase family dysregulation in solid cancers contributes to disease progression and poor patient outcomes, as well as an evaluation of the preclinical landscape of LOX family targeting therapeutics. We also discuss the suitability of the LOX family as a diagnostic and/or prognostic marker in solid tumours.

Transcriptome Analysis of the Inhibitory Effect of Sennoside A on the Metastasis of Hepatocellular Carcinoma Cells

Sennoside A (SA) is a bioactive component of Rheum officinale Baill. with an activity of irritant laxative, which has been reported to possess therapeutic potential in various diseases or conditions including obesity, insulin resistance, liver steatosis, prostate cancer and pancreatic cancer progression. However, whether SA has therapeutic potential in hepatocellular carcinoma (HCC) treatment remains elusive. In this study, we treated two HCC cell lines, HepG2 and SMMC-7721 with SA and found that SA selectively inhibited the growth of HCC cells by proliferation assay. SA has a good inhibitory effect on proliferation of HepG2 cells in a concentration dependent manner, but there was no effect on SMMC-7721 cells. Then we conducted transwell assays and transcriptome analysis in HCC cells and examined the effects of SA on HCC in vivo. The results showed that SA significantly inhibited the migration and invasion of HCC. Comparison of RNA-seq transcriptome profiles from control groups and SA-treated groups identified 171 and 264 differentially expressed genes (DEGs) in HepG2 and SMMC-7721 cells respectively, in which includes 2 overlapping up-regulated DEGs and 12 overlapping down-regulated DEGs between HepG2 and SMMC-7721 cells. The qPCR were applied to investigate the transcriptional level of 9 overlapping down-regulated DEGs related to cancer metastasis, and the results were consistent with RNA-seq data. The dominate pathways including Wnt signaling pathway, TNF signaling pathway, VEGF signaling pathway, and NF-κB signaling pathway were strongly inhibited by SA, which are involved in regulating cancer metastasis. Finally, we confirmed that the downregulation of KRT7 and KRT81 could inhibit HCC metastasis. This study has provided new insight into the understanding of the inhibitory effects and potential targets of SA on the metastasis of HCC.

Lysyl oxidases: Emerging biomarkers and therapeutic targets for various diseases

Therapeutic targeting of extracellular proteins has attracted huge attention in treating human diseases. The lysyl oxidases (LOXs) are a family of secreted copper-dependent enzymes which initiate the covalent crosslinking of collagen and elastin fibers in the extracellular microenvironment, thereby facilitating extracellular matrix (ECM) remodeling and ECM homeostasis. Apart from ECM-dependent roles, LOXs are also involved in other biological processes such as epithelial-to-mesenchymal transition (EMT) and transcriptional regulation, especially following hypoxic stress. Dysregulation of LOXs is found to underlie the onset and progression of multiple pathologies, such as carcinogenesis and cancer metastasis, fibrotic diseases, neurodegeneration and cardiovascular diseases. In this review, we make a comprehensive summarization of clinical and experimental evidences that support roles of for LOXs in disease pathology and points out LOXs as promising therapeutic targets for improving prognosis. Additionally, we also propose that LOXs reshape cell-ECM interaction or cell-cell interaction due to ECM-dependent and ECM-independent roles for LOXs. Therapeutic intervention of LOXs may have advantages in the maintenance of communication between ECM and cell or intercellular signaling, finally recovering organ function.

Evolving roles of lysyl oxidase family in tumorigenesis and cancer therapy

The lysyl oxidase (LOX) family is comprised of LOX and four LOX-like proteins (LOXL1, LOXL2, LOXL3, and LOXL4), and mainly functions in the remodeling of extracellular matrix (ECM) and the cross-linking of collagen and elastic fibers. Recently, a growing body of research has demonstrated that LOX family is critically involved in the regulation of cancer cell proliferation, migration, invasion and metastasis. In this review, we discuss the roles of LOX family members in the development and progression of different types of human cancers. Furthermore, we also describe the potential inhibitors of LOX family proteins and highlight that LOX family might be an important therapeutic target for cancer therapy.

Esophageal Microenvironment: From Precursor Microenvironment to Premetastatic Niche

Esophageal cancer (EC) is the sixth most deadly cancer, and its incidence is still increasing year by year. Although the researches on the molecular mechanisms of EC have been widely carried out and incremental progress has been made, its overall survival rate is still low. There is cumulative evidence showing that the esophageal microenvironment plays a vital role in the development of EC. In precancerous lesions of the esophagus, high-risk environmental factors can promote the development of precancerous lesions by inducing the production of inflammatory factors and the recruitment of immune cells. In the tumor microenvironment, tumor-promoting cells can inhibit anti-tumor immunity and promote tumor progression through a variety of pathways, such as bone marrow-derived suppressor cells (MDSCs), tumor-associated fibroblasts (CAFs), and regulatory T cells (Tregs). The formation of extracellular hypoxia and acidic microenvironment and the change of extracellular matrix stiffness are also important factors affecting tumor progression and metastasis. Simultaneously, primary tumor-derived cytokines and bone marrow-derived immune cells can also promote the formation of pre-metastasis niche of EC lymph nodes, which are beneficial to EC lymph node metastasis. Further research on the specific mechanism of these processes in the occurrence, development, and metastasis of each EC subtype will support us to grasp the overall pre-cancerous prevention, targeted treatment, and metastatic assessment of EC.

Tumor dormancy in bone

Background

Bone marrow is a common site of metastasis for a number of tumor types, including breast, prostate, and lung cancer, but the mechanisms controlling tumor dormancy in bone are poorly understood. In breast cancer, while advances in drug development, screening practices, and surgical techniques have dramatically improved survival rates in recent decades, metastatic recurrence in the bone remains common and can develop years or decades after elimination of the primary tumor.

Recent Findings

It is now understood that tumor cells disseminate to distant metastatic sites at early stages of tumor progression, leaving cancer survivors at a high risk of recurrence. This review will discuss mechanisms of bone lesion development and current theories of how dormant cancer cells behave in bone, as well as a number of processes suspected to be involved in the maintenance of and exit from dormancy in the bone microenvironment.

Conclusions

The bone is a complex microenvironment with a multitude of cell types and processes. Many of these factors, including angiogenesis, immune surveillance, and hypoxia, are thought to regulate tumor cell entry and exit from dormancy in different bone marrow niches.

Lysyl oxidase impacts disease outcomes and correlates with global DNA hypomethylation in esophageal cancer

Abnormal function of human body enzymes and epigenetic alterations such as DNA methylation have been shown to lead to human carcinogenesis. Lysyl oxidase (LOX) enzyme has attracted attention due to its involvement in tumor progression in various cancers. The purpose of this study was to clarify the clinical importance of LOX expression and its epigenetic regulation in the pathogenesis of esophageal squamous cell carcinoma (ESCC). Using a database of 284 ESCCs, we examined LOX expression and its prognostic characteristics. The functional role of LOX was assessed by in vitro growth, migration, and invasion assays. The relationship between LOX expression, global DNA hypomethylation (ie, LINE‐1 methylation), and LOX promoter methylation was evaluated by using mRNA expression arrays and pyrosequencing technology. High LOX expression cases had a significantly shorter overall survival and cancer‐specific survival (log‐rank, P < .001). The prognostic effect of LOX expression was not significantly modified by other clinical variables. Silencing and enzymatic inhibition of LOX suppressed growth and reduced the invasion and migration ability of ESCC cell lines along with the downregulation of AKT and MMP2. An integrated gene analysis in tissues and cell lines revealed that LOX was the most highly upregulated gene in LINE‐1 hypomethylated tumors. In vitro, LOX expression was upregulated following DNA demethylation. LOX promoter methylation was not associated with LOX expression. Conclusively LOX expression was associated with poor prognosis in ESCC and was regulated epigenetically by genome‐wide hypomethylation. It could serve as a prognostic biomarker in ESCC patients, and therapeutically targeting LOX could reverse the progression of esophageal cancer.

Silencing of lysyl oxidase‑like 2 inhibits the migration, invasion and epithelial‑to‑mesenchymal transition of renal cell carcinoma cells through the Src/FAK signaling pathway

The aim of the present study was to investigate the effects of lysyl oxidase-like 2 (LOXL2) on the invasion, migration and epithelial-to-mesenchymal transition (EMT) of renal cell carcinoma (RCC) cells through the steroid receptor coactivator (Src)/focal adhesion kinase (FAK) signaling pathway. RCC tissues and adjacent normal tissues were collected from 80 patients with RCC. Immunohistochemistry was used to determine the positive expression rate of the LOXL2 protein. The expression levels of LOXL2 in the HK-2, 786-O, ACHN, Caki1 and A498 cell lines were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The high LOXL2-expressing 786-O cells were selected for gene silencing experiments, whereas Caki1 cells, which exhibited low LOXL2 expression, were used for overexpression experiments. RT-qPCR and western blot analysis were applied to determine the expression of LOXL2, FAK, Src, matrix metalloproteinase (MMP)-9, epithelial (E)-cadherin, neuronal (N)-cadherin and vimentin. A MTT assay, a Transwell assay, a wound healing assay and flow cytometry were performed to detect cell proliferation, invasion, migration, cell cycle distribution and apoptosis, respectively. The protein expression rate of LOXL2 in RCC tissues was higher compared with that in adjacent normal tissues. Compared with adjacent normal tissues, the mRNA and protein expression levels of LOXL2, FAK, Src, MMP-9, N-cadherin and vimentin and the levels of FAK and Src phosphorylation were increased, while the mRNA and protein expression levels of E-cadherin were decreased in RCC tissues. Following the transfection of 786-O cells with small interfering (si) RNA against LOXL2, the mRNA and protein expression levels of FAK, Src, MMP-9, N-cadherin and vimentin and the levels of phosphorylated FAK and Src were notably decreased in the si-LOXL2 and PP2 inhibitor treated groups, while that of E-cadherin was substantially increased. Additionally, cell proliferation, invasion, migration and the percentage of RCC cells in the G1 phase were reduced, and cell apoptosis was increased. Additionally, Caki1 cells transfected with LOXL2 exhibited an opposite trend. In summary, these results indicate that LOXL2 silencing inhibits the invasion, migration and EMT in RCC cells through inhibition of the Src/FAK signaling pathway.

Divergent roles of lysyl oxidase family members in ornithine decarboxylase- and RAS-transformed mouse fibroblasts and human melanoma cells

We have previously shown that proto-oncoprotein c-Jun is activated in ornithine decarboxylase (ODC)- and RAS-transformed mouse fibroblasts, and that the transformed morphology of these cells can be reversed by expressing the transactivation domain deletion mutant of c-Jun (TAM67). Here, we found that lysyl oxidase (Lox), encoding an extracellular matrix-modifying enzyme, is downregulated in a c-Jun-dependent manner in ODC-transformed fibroblasts (Odc cells). In addition to Lox, the Lox family members Lox-like 1 and 3 (Loxl1 and Loxl3) were found to be downregulated in Odc as well as in RAS-transformed fibroblasts (E4), whereas Lox-like 4 (Loxl4) was upregulated in Odc and downregulated in E4 cells compared to normal N1 fibroblasts. Tetracycline-regulatable LOX re-expression in Odc cells led to inhibition of cell growth and invasion in three-dimensional Matrigel in an activity-independent manner. On the contrary, LOX and especially LOXL2, LOXL3, and LOXL4 were found to be upregulated in several human melanoma cell lines, and LOX inhibitor B-aminopropionitrile inhibited the invasive growth of these cells particularly when co-cultured with fibroblasts in Matrigel. Knocking down the expression of LOX and especially LOXL2 in melanoma cells almost completely abrogated the invasive growth capability. Further, LOXL2 was significantly upregulated in clinical human primary melanomas compared to benign nevi, and high expression of LOXL2 in primary melanomas was associated with formation of metastases and shorter survival of patients. Thus, our studies reveal that inactive pro-LOX (together with Lox propeptide) functions as a tumor suppressor in ODC- and RAS-transformed murine fibroblasts by inhibiting cell growth and invasion, and active LOX and LOXL2 as tumor promoters in human melanoma cells by promoting their invasive growth.

Mutual Expression of ALDH1A1, LOX, and Collagens in Ovarian Cancer Cell Lines as Combined CSCs- and ECM-Related Models of Drug Resistance Development

A major contributor leading to treatment failure of ovarian cancer patients is the drug resistance of cancer cell. CSCs- (cancer stem cells) and ECM (extracellular matrix)-related models of drug resistance are described as independently occurring in cancer cells. Lysyl oxidase (LOX) is another extracellular protein involved in collagen cross-linking and remodeling of extracellular matrix and has been correlated with tumor progression. The expression of LOX, COL1A2, COL3A1, and ALDH1A1 was performed in sensitive (A2780, W1) and resistant to paclitaxel (PAC) (A2780PR1 and W1PR2) and topotecan (TOP) (W1TR) cell lines at the mRNA (real-time PCR analysis) and protein level (Western blot and immunofluorescence analysis). The ALDH1A1 activity was measured with the ALDEFLUOR test and flow cytometry analysis. The protein expression in ovarian cancer tissues was determined by immunohistochemistry. We observed an increased expression of LOX and collagens in PAC and TOP resistant cell lines. Subpopulations of ALDH1A1 positive and negative cells were also noted for examined cell lines. Additionally, the coexpression of LOX with ALDH1A1 and COL1A2 with ALDH1A1 was observed. The expression of LOX, collagens, and ALDH1A1 was also detected in ovarian cancer lesions. In our study LOX, ALDH1A1 and collagens were found to be coordinately expressed by cells resistant to PAC (LOX, ALDH1A1, and COL1A2) or to TOP (LOX and ALDH1A1). This represents the study where molecules related with CSCs (ALDH1A1) and ECM (LOX, collagens) models of drug resistance are described as occurring simultaneously in ovarian cancer cells treated with PAC and TOP.

Different expression profiles of the lysyl oxidases and matrix metalloproteinases in human ACL fibroblasts after co-culture with synovial cells

Purposes The anterior cruciate ligament (ACL) has poor functional healing response. The synovial tissue surrounding ACL ligament might be a major regulator of the microenvironment in the joint cavity after ACL injury, thus affecting the repair process. Using transwell co-culture, this study explored the direct influence of human synovial cells (HSCs) on ACL fibroblasts (ACLfs) by characterizing the differential expression of the lysyl oxidase family (LOXs) and matrix metalloproteinases (MMP-1, -2, -3), which facilitate extracellular matrix (ECM) repair and degradation, respectively. Methods The mRNA expression levels of LOXs and MMP-1, -2, -3 were analyzed by semi-quantitative PCR and quantitative real-time PCR. The protein expression levels of LOXs and MMP-1, -2, -3 were detected by western blot. Results We found that co-culture resulted in an increase in the mRNAs of LOXs in normal ACLfs and differentially regulated the expression of MMPs. Then we applied 12% mechanical stretch on ACLfs to induce injury and found the mRNA expression levels of LOXs in injured ACLfs were decreased in the co-culture group relative to the mono-culture group. Conversely, the mRNA expression levels of MMPs in injured ACLfs were promoted in the co-culture group compared with the mono-culture group. At translational level, we found that LOXs were lower while MMPs were highly expressed in the co-culture group compared to the mono-culture group. Conclusions The co-culture of ACLfs and HSCs, which mimicked the cell-to-cell contact in a micro-environment, could contribute to protein modulators for wound healing, inferring the potential reason for the poor self-healing of injured ACL.

Engineering Breast Cancer Microenvironments and 3D Bioprinting

The extracellular matrix (ECM) is a critical cue to direct tumorigenesis and metastasis. Although two-dimensional (2D) culture models have been widely employed to understand breast cancer microenvironments over the past several decades, the 2D models still exhibit limited success. Overwhelming evidence supports that three dimensional (3D), physiologically relevant culture models are required to better understand cancer progression and develop more effective treatment. Such platforms should include cancer-specific architectures, relevant physicochemical signals, stromal-cancer cell interactions, immune components, vascular components, and cell-ECM interactions found in patient tumors. This review briefly summarizes how cancer microenvironments (stromal component, cell-ECM interactions, and molecular modulators) are defined and what emerging technologies (perfusable scaffold, tumor stiffness, supporting cells within tumors and complex patterning) can be utilized to better mimic native-like breast cancer microenvironments. Furthermore, this review emphasizes biophysical properties that differ between primary tumor ECM and tissue sites of metastatic lesions with a focus on matrix modulation of cancer stem cells, providing a rationale for investigation of underexplored ECM proteins that could alter patient prognosis. To engineer breast cancer microenvironments, we categorized technologies into two groups: (1) biochemical factors modulating breast cancer cell-ECM interactions and (2) 3D bioprinting methods and its applications to model breast cancer microenvironments. Biochemical factors include matrix-associated proteins, soluble factors, ECMs, and synthetic biomaterials. For the application of 3D bioprinting, we discuss the transition of 2D patterning to 3D scaffolding with various bioprinting technologies to implement biophysical cues to model breast cancer microenvironments.

Charting the unexplored extracellular matrix in cancer

The extracellular matrix (ECM) is present in all solid tissues and considered a master regulator of cell behaviour and phenotype. The importance of maintaining the correct biochemical and biophysical properties of the ECM, and the subsequent regulation of cell and tissue homeostasis, is illustrated by the simple fact that the ECM is highly dysregulated in many different types of disease, especially cancer. The loss of tissue ECM homeostasis and integrity is seen as one of the hallmarks of cancer and typically defines transitional events in progression and metastasis. The vast majority of cancer studies place an emphasis on exploring the behaviour and intrinsic signalling pathways of tumour cells. Their goal was to identify ways to target intracellular pathways regulating cancer. Cancer progression and metastasis are powerfully influenced by the ECM and thus present a vast, unexplored repository of anticancer targets that we are only just beginning to tap into. Deconstructing the complexity of the tumour ECM landscape and identifying the interactions between the many cell types, soluble factors and extracellular-matrix proteins have proved challenging. Here, we discuss some of the emerging tools and platforms being used to catalogue and chart the ECM in cancer.

Expression of Lysyl Oxidase Predictive of Distant Metastasis of Laryngeal Cancer

Objective

To investigate the prognostic significance of lysyl oxidase (LOX) expression in laryngeal cancer.

Study Design

Retrospective chart review and histologic analysis.

Setting

Tertiary referral academic center.

Subjects and Methods

Patients (N = 100) underwent surgical treatment for laryngeal cancer and had tissue specimens available. Immunohistochemical staining for LOX was performed on laryngeal cancer tissue microarrays, and the proportion and intensity of staining were evaluated. Patients with LOX scores ≤6 were classified into the low LOX group, while those with scores >6 were classified into the high LOX group. We analyzed the correlation between LOX expression and clinical factors as well as prognosis.

Results

LOX was predominantly expressed in the cytoplasm and nuclei of tumor cells. Kaplan-Meier analysis revealed that the high LOX group had worse overall survival and recurrence-free survival rates than the low LOX group ( P < .05). LOX expression exhibited marginally significant correlation with lymph node metastasis. In the Cox regression analysis, LOX expression and lymph node metastasis were significant factors correlated with overall survival rate (odds ratio [OR] = 3.92, 95% confidence interval [95% CI]: 1.35-11.37, P = .012; OR = 1.96, 95% CI: 0.93-1.43, P = .024, respectively). LOX expression was related to distant metastasis free survival rate (OR = 7.72, 95% CI: 1.02-19.18, P = .048).

Conclusion

A high expression level of LOX is associated with lymph node and distant metastasis as well as poor prognosis among patients with laryngeal cancer.

Inhibition of nuclear factor-kappa B enhances the tumor growth of ovarian cancer cell line derived from a low-grade papillary serous carcinoma in p53-independent pathway

Background

NF-kB can function as an oncogene or tumor suppressor depending on cancer types. The role of NF-kB in low-grade serous ovarian cancer, however, has never been tested. We sought to elucidate the function of NF-kB in the low-grade serous ovarian cancer.

Methods

The ovarian cancer cell line, HOC-7, derived from a low-grade papillary serous carcinoma. Introduction of a dominant negative mutant, IkBαM, which resulted in decrease of NF-kB function in ovarian cancer cell lines. The transcription ability, tumorigenesis, cell proliferation and apoptosis were observed in derivative cell lines in comparison with parental cells.

Results

Western blot analysis indicated increased expression of the anti-apoptotic proteins Bcl-xL and reduced expression of the pro-apoptotic proteins Bax, Bad, and Bid in HOC-7/IĸBαM cell. Further investigations validate this conclusion in KRAS wildtype cell line SKOV3. Interesting, NF-kB can exert its pro-apoptotic effect by activating mitogen-activated protein kinase (MAPK) phosphorylation in SKOV3 ovarian cancer cell, whereas opposite changes detected in p-MEK in HOC-7 ovarian cancer cell, the same as some chemoresistant ovarian cancer cell lines. In vivo animal assay performed on BALB/athymic mice showed that injection of HOC-7 induced subcutaneous tumor growth, which was completely regressed within 7 weeks. In comparison, HOC-7/IĸBαM cells caused sustained tumor growth and abrogated tumor regression, suggesting that knock-down of NF-kB by IĸBαM promoted sustained tumor growth and delayed tumor regression in HOC-7 cells.

Conclusion

Our results demonstrated that NF-kB may function as a tumor suppressor by facilitating regression of low grade ovarian serous carcinoma through activating pro-apoptotic pathways.

Characterization of clear cell renal cell carcinoma by gene expression profiling

OBJECTIVES

Use global gene expression to characterize differences between high-grade and low-grade clear cell renal cell carcinoma (ccRCC) compared with normal and benign renal tissue.

METHODS

Tissue samples were collected from patients undergoing surgical resection for ccRCC. Affymetrix gene expression arrays were used to examine global gene expression patterns in high- (n = 16) and low-grade ccRCC (n = 13) as well as in samples from normal kidney (n =14) and benign kidney disease (n = 6). Differential gene expression was determined by analysis of variance with a false discovery rate of 1% and a 2-fold cutoff.

RESULTS

Comparing high-grade ccRCC with each of normal and benign kidney resulted in 1,833 and 2,208 differentially expressed genes, respectively. Of these, 930 were differentially expressed in both comparisons. In order to identify genes most related to progression of ccRCC, these differentially expressed genes were filtered to identify genes that showed a pattern of expression with a magnitude of change greater in high-grade ccRCC in the comparison to low-grade ccRCC. This resulted in the identification of genes such as TMEM45A, ceruloplasmin, and E-cadherin that were involved in cell processes of cell differentiation and response to hypoxia. Additionally changes in HIF1α and TNF signaling are highly represented by changes between high- and low-grade ccRCC.

CONCLUSIONS

Gene expression differences between high-grade and low-grade ccRCC may prove to be valuable biomarkers for advanced ccRCC. In addition, altered signaling between grades of ccRCC may provide important insight into the biology driving the progression of ccRCC and potential targets for therapy.

Epigenetic Therapy for Solid Tumors: Highlighting the Impact of Tumor Hypoxia

In the last few decades, epigenetics has emerged as an exciting new field in development and disease, with a more recent focus towards cancer. Epigenetics has classically referred to heritable patterns of gene expression, primarily mediated through DNA methylation patterns. More recently, it has come to include the reversible chemical modification of histones and DNA that dictate gene expression patterns. Both the epigenetic up-regulation of oncogenes and downregulation of tumor suppressors have been shown to drive tumor development. Current clinical trials for cancer therapy include pharmacological inhibition of DNA methylation and histone deacetylation, with the aim of reversing these cancer-promoting epigenetic changes. However, the DNA methyltransferase and histone deacetylase inhibitors have met with less than promising results in the treatment of solid tumors. Regions of hypoxia are a common occurrence in solid tumors. Tumor hypoxia is associated with increased aggressiveness and therapy resistance, and importantly, hypoxic tumor cells have a distinct epigenetic profile. In this review, we provide a summary of the recent clinical trials using epigenetic drugs in solid tumors, discuss the hypoxia-induced epigenetic changes and highlight the importance of testing the epigenetic drugs for efficacy against the most aggressive hypoxic fraction of the tumor in future preclinical testing.

Lysyl oxidase in cancer research

Metastasis is the main reason for cancer-associated deaths and therapies are desperately needed to target the progression of cancer. Lysyl oxidase (LOX) plays a pivotal role in cancer progression, including metastasis, and is therefore is an attractive therapeutic target. In this review we will breakdown the process of cancer progression and the various roles that LOX plays has in the advancement of cancer. We will highlight why LOX is an exciting therapeutic target for the future.

LOX expression and functional analysis in astrocytomas and impact of IDH1 mutation

Lysyl oxidase (LOX) is involved in vital biological processes such as cell motility, cell signaling and gene regulation. Deregulation of this protein can contribute to tumor formation and progression. Although it is known that LOX is involved in invasion, proliferation and tumor migration in other types of tumors, studies of LOX in astrocytomas of different grades are scarce. The purpose of our study was to characterize LOX, BMP1 and HIF1A expression by real-time PCR in astrocytomas with WHO grades I to IV compared to non-neoplastic brain tissue. IDH1 mutational status was determined by PCR and sequencing. LOX protein expression was also analyzed by immunohistochemistry. LOX functional analyses were performed using siRNA knockdown and the specific inhibitor BAPN in two glioblastoma cell lines. The expression levels of LOX, BMP1 and HIF1A were correlated and analyzed according to IDH1 mutation status and to the clinical end-point of overall survival of glioblastoma patients. The results demonstrate that increased expression and activity of LOX, BMP1 and HIF1A were positively correlated with the malignant grade of astrocytomas. LOX protein expression also increased according to the degree of malignancy, with localization in the cytoplasm and nucleus and staining observed in endothelial cells. Glioblastoma with a mutation in IDH1 expressed lower levels of LOX in the nucleus, and IDH1-mutated cases showed lower LOX expression levels when compared to wild-type IDH1 cases. LOX knockdown and inhibition by BAPN in U87MG and A172 cell lines affected migration, invasion and soft agar colony formation. Taken together, these results corroborate the role of LOX in the migration, invasion and angiogenesis of astrocytomas. Furthermore, LOX expression is influenced by IDH1 mutational status. This work provides new insights for researchers aiming to design targeted therapies to control astrocytomas.

High expression of glucose transporter 1 on primary lesions of esophageal squamous cell carcinoma is associated with hematogenous recurrence

PURPOSE

Glucose transporter type 1 (Glut1) plays a crucial role in cancer-specific metabolism to adapt to the rapid growth and tumor microenvironment in diverse malignant tumors. This study examined the clinical, pathological, and prognostic features of Glut1 expression on primary lesions of esophageal squamous cell carcinoma.

METHODS

Immunohistochemical staining of Glut1 and CD34 was performed using paraffin-embedded sections of tissues obtained from 145 resectable esophageal squamous cell carcinoma patients without preoperative treatment. Microvessel density was calculated from CD34 staining.

RESULTS

Glut1 positivity was observed in 41 patients (28.2 %) and associated with depth of invasion [odds ratio (OR) 2.984; 95 % confidence interval (CI) 1.208-7.371; P = 0.018] and vascular invasion (OR 2.771; 95 % CI 1.118-6.871; P = 0.028) in multivariate analysis. Glut1 positivity was a significant disadvantage to both relapse-free survival [hazard ratio (HR) 2.021; 95 % CI 1.100-3.712; P = 0.023] and esophageal cancer-specific survival (HR 2.223; 95 % CI 1.121-4.411; P = 0.022) in univariate Cox hazard analysis, but was not independently associated with relapse-free survival or cancer-specific survival in multivariate analysis. The relationship between Glut1 expression and first relapse site was investigated. Glut1 positivity was not associated with lymph node recurrence (HR 1.009; 95 % CI 0.402-2.530; P = 0.985) but was significantly associated with hematogenous recurrence (HR 3.701; 95 % CI 1.655-8.273; P = 0.001) in univariate Cox hazard analysis. Microvessel density was calculated to evaluate angiogenesis, and it was observed that Glut1 positivity was significantly associated with high microvessel density (P < 0.001).

CONCLUSIONS

Glut1 expression was associated with hematogenous recurrence. The findings provide evidence of the significance of Glut1 expression as a biomarker.

Transcriptional profiling identifies upregulated genes following induction of epithelial-mesenchymal transition in squamous carcinoma cells

During the progression of head and neck squamous cell carcinoma (HNSCC), the induction of an epithelial-mesenchymal transition (EMT) program may play a critical role in the dissemination of cells from the primary tumor to distant metastatic foci. The process of EMT involves the activation of several important genes and pathways to help maintain survival and growth and evolve into highly invasive and metastatic variants. In this study, expression microarray analysis identified a set of 145 upregulated genes in EMT-like HNSCC cells. Some of the strongly upregulated transcripts include genes that are reportedly involved in invasion and metastasis, such as DOCK10, LOX, ROBO1 and SRGN. Importantly, the Tbx3 gene, a member of the T-box transcription factor, was strongly upregulated in SCC cells displaying an EMT-like phenotype compared to cells with an epitheloid, non-EMT behavior. Tbx3 was also found to be strongly upregulated at the protein and gene expression level in an experimental model of snail-induced EMT cells. In addition, siRNA-induced Tbx3 depletion modestly suppressed cell invasion while enhancing Tbx3-mediated resistance to anoikis. Our findings provide evidence that Tbx3 overexpression promotes SCC cell survival displaying an EMT phenotype. This set of newly identified genes that are modulated during EMT-like conversion may be important diagnostic biomarkers during the process of HNSCC progression.

Berberine inhibits pulmonary metastasis through down-regulation of MMP in metastatic B16F-10 melanoma cells

The present study demonstrated the potential antimetastatic and antiinvasive effect of berberine using both in vivo mouse lung metastasis and in vitro models. Administration of berberine resulted in significant suppression of B16F-10 melanoma induced tumor nodule formation and enhanced the survival of tumor-bearing mice. Berberine treatment also decreased various biochemical parameters associated with lung metastasis. These inhibitory actions may be due to the significant suppression of several signaling molecules such as ERK1/2, NF-κB, ATF-2 and CREB involved in the transcription signaling pathways for MMP gene expression. It could also inhibit the migration and invasion of highly metastatic murine melanoma cells in a dose-dependent manner in vitro. The results clearly show that berberine could significantly inhibit experimental lung metastasis produced by intravenous injection of B16F-10 melanoma cells and this effect could be linked to the down-regulation of metastasis-related signaling molecules.

Deregulation of FoxM1b leads to tumour metastasis

The forkhead box M1b (FoxM1b) transcription factor is over-expressed in human cancers, and its expression often correlates with poor prognosis. Previously, using conditional knockout strains, we showed that FoxM1b is essential for hepatocellular carcinoma (HCC) development. However, over-expression of FoxM1b had only marginal effects on HCC progression. Here we investigated the effect of FoxM1b expression in the absence of its inhibitor Arf. We show that transgenic expression of FoxM1b in an Arf-null background drives hepatic fibrosis and metastasis of HCC. We identify novel mechanisms of FoxM1b that are involved in epithelial–mesenchymal transition, cell motility, invasion and a pre-metastatic niche formation. FoxM1b activates the Akt-Snail1 pathway and stimulates expression of Stathmin, lysyl oxidase, lysyl oxidase like-2 and several other genes involved in metastasis. Furthermore, we show that an Arf-derived peptide, which inhibits FoxM1b, impedes metastasis of the FoxM1b-expressing HCC cells. The observations indicate that FoxM1b is a potent activator of tumour metastasis and that the Arf-mediated inhibition of FoxM1b is a critical mechanism for suppression of tumour metastasis.

Prognostic significance of CD151 expression in esophageal squamous cell carcinoma with aggressive cell proliferation and invasiveness

BACKGROUND

CD151 is a member of the tetraspanins and has recently been reported as a promoter of the malignant progression of cancer. The purpose of this study was to clarify the clinicopathological outcome and prognostic significance of the immunohistochemical expression of CD151 in esophageal squamous cell carcinoma (ESCC).

METHODS

We evaluated the significance of CD151 expression by immunohistochemistry in 138 surgically resected ESCC and the association of CD151 expression with clinicopathological features.

RESULTS

Seventy-five (51.7%) ESCC showed a positive expression of CD151, which indicated a significant association with tumor depth (P = 0.004), lymph node metastasis (P = 0.002), distant metastasis (P = 0.025), and lymphatic invasion (P = 0.046), as well as the Ki-67 labeling index (P = 0.011). The 5-year survival rate of ESCC patients with CD151-positive expression was significantly lower than with CD151-negative expression (positive, 43.1%; negative, 63.8%; P = 0.003). Multivariate analysis showed that positive CD151 expression was not an independent factor for poor survival (P = 0.096).

CONCLUSIONS

CD151 expression is associated with tumor proliferation and invasiveness in ESCC.

Hypoxia, inflammation, and the tumor microenvironment in metastatic disease

Metastasis, the leading cause of cancer deaths, is an intricate process involving many important tumor and stromal proteins that have yet to be fully defined. This review discusses critical components necessary for the metastatic cascade, including hypoxia, inflammation, and the tumor microenvironment. More specifically, this review focuses on tumor cell and stroma interactions, which allow cell detachment from a primary tumor, intravasation to the blood stream, and extravasation at a distant site where cells can seed and tumor metastases can form. Central players involved in this process and discussed in this review include integrins, matrix metalloproteinases, and soluble growth factors/matrix proteins, including the connective tissue growth factor and lysyl oxidase.