Osteopontin is involved in TLR4 pathway contributing to ovarian cancer cell proliferation and metastasis

Osteopontin promotes gastric cancer progression via phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

BACKGROUND

Gastric cancer (GC) is one of the most common malignant tumors. Osteopontin (OPN) is thought to be closely related to the occurrence, metastasis and prognosis of many types of tumors.

AIM

To investigate the effects of OPN on the proliferation, invasion and migration of GC cells and its possible mechanism.

METHODS

The mRNA and protein expression of OPN in the GC cells were analyzed by real-time quantitative-reverse transcription polymerase chain reaction and western blotting, and observe the effect of varying degree expression OPN on the proliferation and other behaviors of GC. Next, the effects of OPN knockdown on GC cells migration and invasion were examined. The short hairpin RNA (shRNA) and negative control shRNA targeting OPN-shRNA were transfected into the cells according to the manufacturer's instructions. Non transfected cells were classified as control in the identical transfecting process. 24 h after RNA transfection cell proliferation activity was detected by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide assay, and cell invasiveness and migration were detected by Trans well assay. Meanwhile, the expression of protein kinase B (AKT), matrix metalloproteinase 2 (MMP-2) and vascular endothelial growth factor (VEGF) in the human GC cell lines was detected by reverse transcription polymerase chain reaction and western blotting.

RESULTS

The results of this study revealed that OPN mRNA and protein expression levels were highly expressed in SGC-7901 cells. OPN knockdown by specific shRNA noticeably reduced the capabilities of proliferation, invasion and migration of SGC-7901 cells. Moreover, in the experiments of investigating the underlying mechanism, results showed that OPN knockdown could down-regulated the expression of MMP-2 and VEGF, it also decreased the phosphorylation of AKT. Meanwhile, the protein expression levels of MMP-2, VEGF and phosphorylated AKT was noticeable lower than that in control group in the GC cells after they were added to phosphatidylinositol-3-kinase (PI3K) inhibitor (LY294002).

CONCLUSION

These results suggested that OPN though PI3K/AKT/mammalian target of rapamycin signal pathway to up-regulate MMP-2 and VEGF expression, which contribute SGC-7901 cells to proliferation, invasion and migration. Thus, our results demonstrate that OPN may serve as a novel prognostic biomarkers as well as a potential therapeutic targets for GC.

Identification of the Immune Signatures for Ovarian Cancer Based on the Tumor Immune Microenvironment Genes

Ovarian cancer (OV) is a deadly gynecological cancer. The tumor immune microenvironment (TIME) plays a pivotal role in OV development. However, the TIME of OV is not fully known. Therefore, we aimed to provide a comprehensive network of the TIME in OV. Gene expression data and clinical information from OV patients were obtained from the Cancer Genome Atlas Program (TCGA) database. Non-negative Matrix Factorization, NMFConsensus, and nearest template prediction algorithms were used to perform molecular clustering. The biological functions of differentially expressed genes (DEGs) were identified using Metascape, gene set enrichment analysis (GSEA), gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The copy number variations (CNVs), single nucleotide polymorphisms (SNPs) and tumor mutation burden were analyzed using Gistic 2.0, R package maftools, and TCGA mutations, respectively. Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data and CIBERSORT were utilized to elucidate the TIME. Moreover, external data from the International Cancer Genome Consortium (ICGC) and ArrayExpress databases were used to validate the signature. All 361 samples from the TCGA OV dataset were classified into Immune Class and non-Immune Class with immune signatures. By comparing the two classes, we identified 740 DEGs that accumulated in immune-related, cancer-related, inflammation-related biological functions and pathways. There were significant differences in the CNVs between the Immune and non-Immune Classes. The Immune Class was further divided into immune-activated and immune-suppressed subtypes. There was no significant difference in the top 20 genes in somatic SNPs among the three groups. In addition, the immune-activated subtype had significantly increased proportions of CD4 memory resting T cells, T cells, M1 macrophages, and M2 macrophages than the other two groups. The qRT-PCR results indicated that the mRNA expression levels of RYR2, FAT3, MDN1 and RYR1 were significantly down-regulated in OV compared with normal tissues. Moreover, the signatures of the TIME were validated using ICGC cohort and the ArrayExpress cohort. Our study clustered the OV patients into an immune-activated subtype, immune-suppressed subtype, and non-Immune Class and provided potential clues for further research on the molecular mechanisms and immunotherapy strategies of OV.

Endocrine regulation and metabolic mechanisms of osteopontin in the development and progression of osteosarcoma, metastasis and prognosis

Osteosarcoma is the most common type of malignant bone tumor, occurring in adolescents and patients over 60. It has a bimodal onset and a poor prognosis, and its development has not yet been fully explained. Osteopontin (OPN) is a high protein consisting of 314 amino acid residues with a negative charge and is involved in many biological activities. OPN is not only an essential part of the regulation of the nervous system and endocrine metabolism of skeletal cells. Still, it is also involved in several other important biological activities, such as the division, transformation, and proliferation of skeletal cells and their associated cells, such as bone tumor cells, including bone marrow mesenchymal stem cells, hematopoietic stem cells, osteoblasts, and osteoclasts. Osteoblasts and osteocytes. Recent studies have shown a strong correlation between OPN and the development and progression of many skeletal diseases, such as osteosarcoma and rheumatoid arthritis. This review aims to understand the mechanisms and advances in the role of OPN as a factor in the development, progression, metastasis, and prognosis of osteosarcoma in an attempt to provide a comprehensive summary of the mechanisms by which OPN regulates osteosarcoma progression and in the hope of contributing to the advancement of osteosarcoma research and clinical treatment.

Design and optimisation of a small-molecule TLR2/4 antagonist for anti-tumour therapy

In anti-tumour therapy, the toll-like receptor 2/4 (TLR2/4) signalling pathway has been a double-edged sword. TLR2/4 agonists are commonly considered adjuvants for immune stimulation, whereas TLR2/4 antagonists demonstrate more feasibility for anti-tumour therapy under specific chronic inflammatory situations. In individuals with cancer retaliatory proliferation and metastasis after surgery, blocking the TLR2/4 signalling pathway may produce favourable prognosis for patients. Therefore, here, we developed a small-molecule co-inhibitor that targets the TLR2/4 signalling pathway. After high-throughput screening of a compound library containing 14 400 small molecules, followed by hit-to-lead structural optimisation, we finally obtained the compound TX-33, which has effective inhibitory properties against the TLR2/4 signalling pathways. This compound was found to significantly inhibit multiple pro-inflammatory cytokines released by RAW264.7 cells. This was followed by TX-33 demonstrating promising efficacy in subsequent anti-tumour experiments. The current results provide a novel understanding of the role of TLR2/4 in cancer and a novel strategy for anti-tumour therapy.

Osteopontin Regulates Endometrial Stromal Cell Migration in Endometriosis through the PI3K Pathway : Osteopontin Regulates Endometrial Cell Migration in Endometriosis

Endometriosis is generally characterized as a tumor-like disease because of its potential for distant metastasis and local tissue invasion, while whether osteopontin (OPN) plays a role in the pathogenesis of endometriosis has not been thoroughly investigated. We investigated the expression of OPN, urokinase plasminogen activator (uPA), phosphatidylinositol 3 kinase (PI3K), and phospho-PI3 kinase (p-PI3K) in endometrial stromal cells (ESCs). The serum concentration of OPN was determined by enzyme-linked immunosorbent assays (ELISA). OPN was downregulated to explore the corresponding change of uPA, p-PI3K, F-actin, and α-tubulin. The expression of OPN, uPA, PI3K, and p-PI3K was evaluated by western blot and quantitative real-time PCR (RT-qPCR) and the expression of F-actin and α-tubulin was confirmed by immunofluorescence assay. The proliferation and migration abilities of ESCs were investigated by CCK8, transwell, and wound scratch assays. Endometrial OPN, p-PI3K, and uPA expressions and serum OPN levels were increased in patients with endometriosis compared with the control. The expressions of p-PI3K, uPA, and α-tubulin were decreased by siRNA-OPN interference in ectopic ESCs. Activation and inhibition of the PI3K pathway apparently upregulate and downregulate uPA expression. Knockdown of OPN and inhibition of the PI3K pathway remarkably inhibited cell migration in ectopic ESCs. Meanwhile, activation of the PI3K pathway promoted the migration ability of ectopic ESCs. OPN may regulate the expression of uPA through the PI3K signal pathway to affect the migration ability of ESCs, indicating that OPN, uPA, and the PI3K pathway may be potential targets for interrupting development of endometriosis.

Protective Innate Immune Variants in Racial/Ethnic Disparities of Breast and Prostate Cancer

Individuals of African descent are disproportionately affected by specific complex diseases, such as breast and prostate cancer, which are driven by both biological and nonbiological factors. In the case of breast cancer, there is clear evidence that psychosocial factors (environment, socioeconomic status, health behaviors, etc.) have a strong influence on racial disparities. However, even after controlling for these factors, overall phenotypic differences in breast cancer pathology remain among groups of individuals who vary by geographic ancestry. There is a growing appreciation that chronic/reoccurring inflammation, primarily driven by mechanisms of innate immunity, contributes to core functions associated with cancer progression. Germline mutations in innate immune genes that have been retained in the human genome offer enhanced protection against environmental pathogens, and protective innate immune variants against specific pathogens are enriched among populations whose ancestors were heavily exposed to those pathogens. Consequently, it is predicted that racial/ethnic differences in innate immune programs will translate into ethnic differences in both pro- and antitumor immunity, tumor progression, and prognosis, leading to the current phenomenon of racial/ethnic disparities in cancer. This review explores examples of protective innate immune genetic variants that are (i) distributed disproportionately among racial populations and (ii) associated with racial/ethnic disparities of breast and prostate cancer.

The role of Toll-like receptor 4 signaling pathway in ovarian, cervical, and endometrial cancers

Toll-like receptors (TLRs) are critical sensors related to inflammation and tumorigenesis. Among all subtypes, the TLR4 is a highly described transmembrane protein involved in the inflammatory process. The TLR4/myeloid differentiation factor 88 (MyD88) signaling pathway has been implicated in oncogenic events in several tissues and is associated with survival of patients. Through activation, TLR4 recruits adaptor proteins, i.e., MyD88 or TRIF, to triggers canonical and non-canonical signaling pathways that result in distinct immune responses. In most cancer cells, uncontrolled TLR4 signaling modifies the tumor microenvironment to proliferate and evade immune surveillance. By contrast, TLR4 activation can produce antitumor activities, thereby inhibiting tumor growth and enhancing the proper immune response. We review herein recent approaches on the role of the TLR4 signaling pathway and discuss potential candidates for gynecological cancer therapies; among these agents, natural and synthetic compounds have been tested both in vitro and in vivo. Since TLR4 ligands have been investigated as effective immune-adjuvants in the context of these aggressive malignancies, we described how TLR4 signaling controls part of the tumor-related inflammatory process and which are the new targeting molecules implicated in the regulation of tumorigenicity in ovarian, cervical, and endometrial cancers.

Toll-like receptor 6 expression, sequence variants, and their association with colorectal cancer risk

This is the first study to examine the potential correlation of the rs3796508 and rs5743810 SNPs of the TLR6 gene in patients with colorectal cancer (CRC) in a subset of the Saudi population. TLR6 gene expression was studied by real-time PCR assaysin 10 matching normal and cancer colon tissues. TLR6 expression at the protein level was determined by immunohistochemistry. A case-control search was conductedon 115 case patients and 102 controls. All samples were genotyped with the TaqMan assay for the TLR6 gene. Odds ratios and 95% confidence interval were computed from logistic regression models after adjusting for age, sex, and tumor localization. Our findings showed a decrease in TLR6 expression (p <0.001) in colon cancer tissues when compared to normal colon tissues. Global analysis revealed no significant association between the TLR6 rs3796508 and rs5743810 and CRC in this population. However, the Val/Met genotype of rs3796508 had a significantly higher frequency in the control group than in the cases for the male group (OR= 0.095, and p= 0.03385) or the volunteers aged more than 57 years OR= 0.152; and p= 0.04069, respectively). Two non-synonymous single nucleotide polymorphisms (SNP; S249P and V327M) were common in a few patients and were predicted as damaging by SIFT and Polyphen and were further analyzed for their protein stability and function using advanced bioinformatics tools. The results suggest that TLR6 rs3796508 has a crucial role as a protective factor against colorectal cancer in the older Saudi male population.

Osteopontin as a biomarker for osteosarcoma therapy and prognosis

Osteosarcoma (OS) is the most common bone malignancy, and is particularly prevalent in children and adolescents. OS is an aggressive tumor with a tendency to metastasize and invade to para-carcinoma tissues. The primary treatment for this tumor is a combination of surgery and chemotherapy. However, the prognosis remains poor due to chemoresistance and early metastasis. Osteopontin (OPN), a multifunctional secreted protein, has emerged as an important potential biomarker for diagnosing and treating cancer. The overexpression of OPN has been found in numerous malignant tumors, including breast, lung, gastric and ovarian cancer, as well as melanoma. Recent studies have suggested that OPN may provide an important function in the diagnosis and treatment of OS. The present review summarizes current knowledge and progress in understanding the potential role of OPN as a biomarker in OS.

The activation of Toll-like receptor 4 reverses tumor differentiation in human glioma U251 cells via Notch pathway

Toll-like receptors (TLRs) are closely related to cancer. However, the mechanism for TLR regulation of cancer is not fully understood. Our previous studies demonstrated that toll-like receptor (TLR) 4 functions to maintain the un-differential stem cell phenotypes of human endothelial progenitor cells. In this study, we found that human glioma cells expressed several TLRs. The activation of TLR4 by LPS in glioma U251 cells induced the expression of cytokines, including IL-1β, IL-6, IL-8, and TNFα, suggesting the functional expression of TLR4. Nude mouse in vivo studies showed that LPS treatment promoted tumor growth, and decreased mouse survival. But LPS treatment did not promote tumor cell proliferation in vitro. Meanwhile, we found that LPS treatment down-regulated the expression of glial fibrillary acidic protein (GFAP), an important differentiation maker of glioma, at both mRNA and protein levels. TLR4 activation also down-regulated GFAP in glioma Hs683 cells. LPS did not induce the activation of MAPKs, but induced the activation of NF-κB. However, pharmacological inhibition of NF-κB signaling did not reverse the down-regulation of GFAP. Furthermore, we found that LPS induced the activation of Notch pathway, which was MyD88-dependent, and Notch inhibition reversed the down-regulation of GFAP. In addition, LPS treatment up-regulated stem cell makers, including CD34 and CD133. Taken together, these results suggested that in human glioma U251 cells, TLR4 functions to reverse tumor differentiation, and it may be a target for glioma prevention and therapy.

Resistin facilitates metastasis of lung adenocarcinoma through the TLR4/Src/EGFR/PI3K/NF-κB pathway

Metastasis is the main cause of lung cancer‐related death. The tumor microenvironment greatly contributes to tumor metastasis. Resistin, mainly secreted by tumor‐associated macrophages in tumor tissues, is a 12.5‐kDa cysteine‐rich secretory protein that is found at significantly higher levels in the serum or plasma of cancer patients compared with healthy controls. In this study, we explored the expression and role of resistin in lung adenocarcinoma. Our study showed that resistin was strongly expressed in lung adenocarcinoma tissues and promoted the migration and invasion of lung adenocarcinoma cells in a dose‐dependent manner. Toll‐like receptor 4 (TLR4) was the functional receptor of resistin for migration and invasion in A549 cells. Src/epidermal growth factor receptor (EGFR) was involved in resistin‐induced migration and invasion. Resistin increased the phosphorylation of EGFR through the TLR4/Src pathway. We also found that PI3K/nuclear factor (NF)‐κB were the intracellular downstream effectors mediating resistin‐induced migration and invasion. Taken together, our results suggested that resistin promoted lung adenocarcinoma metastasis through the TLR4/Src/EGFR/PI3K/NF‐κB pathway.