p38 kinase is crucial for osteopontin-induced furin expression that supports cervical cancer progression

The role of NF-κB in carcinogenesis of cervical cancer: opportunities and challenges

The nuclear factor-κB (NF-κB) family, consisting of several transcription factors, has been implicated in the regulation of cell proliferation and invasion, as well as inflammatory reactions and tumor development. Cervical cancer (CC) results from long-term interactions of multiple factors, among which persistent high-risk human papillomavirus (hrHPV) infection is necessary. During different stages from early to late after HPV infection, the activity of NF-κB varies and plays various roles in carcinogenesis and progress of CC. As the center of the cell signaling transduction network, NF-κB can be activated through classical and non-classical pathways, and regulate the expression of downstream target genes involved in regulating the tumor microenvironment and acquiring hallmark traits of CC cells. Targeting NF-κB may help treat CC and overcome the resistance to radiation and chemotherapy. Even though NF-κB inhibitors have not been applied in clinical treatment as yet, due to limitations such as dose-restrictive toxicity and poor tumor-specificity, it is still considered to have significant therapeutic potential and application prospects. In this review, we focus on the role of NF-κB in the process of CC occurrence and hallmark capabilities acquisition. Finally, we summarize relevant NF-κB-targeted treatments, providing ideas for the prevention and treatment of CC.

The route of autophagy regulation by osteopontin: a review on the linking mechanisms

Autophagy is a dynamic intracellular process of protein degradation, which is mostly triggered by nutrient deprivation. This process initiates with the formation of autophagosomes, which they capture cytosolic material that is then degraded upon fusion with the lysosome. Several factors have been found to be associated with autophagy modulation, of which extracellular matrix (ECM) components has attracted the attention of recent studies. Osteopontin (OPN) is an important extracellular matrix component that has been detected in a wide range of tumor cells, and is involved in cancer cell invasion and metastasis. Recently, a number of studies have focused on the relationship of OPN with autophagy, by delineating the intracellular signaling pathways that connect OPN to the autophagy process. We will summarize signaling pathways and cell surface receptors, through which OPN regulates the process of autophagy.

COVID-19 Molecular Pathophysiology: Acetylation of Repurposing Drugs

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces immune-mediated type 1 interferon (IFN-1) production, the pathophysiology of which involves sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1) tetramerization and the cytosolic DNA sensor cyclic-GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. As a result, type I interferonopathies are exacerbated. Aspirin inhibits cGAS-mediated signaling through cGAS acetylation. Acetylation contributes to cGAS activity control and activates IFN-1 production and nuclear factor-κB (NF-κB) signaling via STING. Aspirin and dapsone inhibit the activation of both IFN-1 and NF-κB by targeting cGAS. We define these as anticatalytic mechanisms. It is necessary to alleviate the pathologic course and take the lag time of the odds of achieving viral clearance by day 7 to coordinate innate or adaptive immune cell reactions.

Could a Lower Toll-like Receptor (TLR) and NF-κB Activation Due to a Changed Charge Distribution in the Spike Protein Be the Reason for the Lower Pathogenicity of Omicron?

The novel SARS-CoV-2 Omicron variant B.1.1.529, which emerged in late 2021, is currently active worldwide, replacing other variants, including the Delta variant, due to an enormously increased infectivity. Multiple substitutions and deletions in the N-terminal domain (NTD) and the receptor binding domain (RBD) in the spike protein collaborate with the observed increased infectivity and evasion from therapeutic monoclonal antibodies and vaccine-induced neutralizing antibodies after primary/secondary immunization. In contrast, although three mutations near the S1/S2 furin cleavage site were predicted to favor cleavage, observed cleavage efficacy is substantially lower than in the Delta variant and also lower compared to the wild-type virus correlating with significantly lower TMPRSS2-dependent replication in the lungs, and lower cellular syncytium formation. In contrast, the Omicron variant shows high TMPRSS2-independent replication in the upper airway organs, but lower pathogenicity in animal studies and clinics. Based on recent data, we present here a hypothesis proposing that the changed charge distribution in the Omicron’s spike protein could lead to lower activation of Toll-like receptors (TLRs) in innate immune cells, resulting in lower NF-κB activation, furin expression, and viral replication in the lungs, and lower immune hyper-activation.

Biological and Clinicopathological Characteristics of OPN in Cervical Cancers

Background: Cervical cancer (CC) is the most common gynecological malignancy. Recently, an increasing number of studies have indicated that osteopontin (OPN) is a promising diagnostic and prognostic biomarker for CC. However, the biological role and detailed mechanism of OPN in CC remain unclear.

Methods: The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets and a clinical sample microarray were used in our study. To identify the clinicopathological characteristics of OPN in CC, we compared the expression of OPN between normal and CC tissue samples and analyzed the correlations between OPN expression and multiple clinicopathological features. To identify biological processes involving OPN, OPN-associated genes were screened with Pearson correlation analysis and applied in hallmark gene set enrichment analysis (GSEA). Additionally, leukocyte infiltration was evaluated based on OPN expression. Finally, OPN-related signaling pathways were identified by GSEA.

Results: OPN expression was higher in CC samples than in normal tissue samples and positively correlated with age, FIGO stage, tumor size, lymphovascular invasion and an unfavorable prognosis. OPN-associated genes were mainly enriched in the immune response, and increased OPN expression was accompanied by increased M2 macrophage infiltration. Additionally, OPN was correlated with hypoxia, high glycolytic metabolism, apoptosis, angiogenesis, epithelial-mesenchymal transition and multiple signaling pathways (the p53 pathway, the PI3K/Akt pathway, IL6/STAT3 signaling, mTORC1 signaling and KRAS signaling).

Conclusion: Our study showed that OPN is involved in immunological activities and multiple tumor processes, identifying it as a potential therapeutic target and useful prognostic factor in CC patients.

p38 MAPK priming boosts VSMC proliferation and arteriogenesis by promoting PGC1α-dependent mitochondrial dynamics

Vascular smooth muscle cell (VSMC) proliferation is essential for arteriogenesis to restore blood flow after artery occlusion, but the mechanisms underlying this response remain unclear. Based on our previous findings showing increased VSMC proliferation in the neonatal aorta of mice lacking the protease MT4-MMP, we aimed at discovering new players in this process. We demonstrate that MT4-MMP absence boosted VSMC proliferation in vitro in response to PDGF-BB in a cell-autonomous manner through enhanced p38 MAPK activity. Increased phospho-p38 in basal MT4-MMP-null VSMCs augmented the rate of mitochondrial degradation by promoting mitochondrial morphological changes through the co-activator PGC1α as demonstrated in PGC1α^−/− VSMCs. We tested the in vivo implications of this pathway in a novel conditional mouse line for selective MT4-MMP deletion in VSMCs and in mice pre-treated with the p38 MAPK activator anisomycin. Priming of p38 MAPK activity in vivo by the absence of the protease MT4-MMP or by anisomycin treatment led to enhanced arteriogenesis and improved flow recovery after femoral artery occlusion. These findings may open new therapeutic opportunities for peripheral vascular diseases.

Periodontitis promotes the expression of gingival transmembrane serine protease 2 (TMPRSS2), a priming protease for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Objectives

The oral cavity is one of the main entry sites for SARS-CoV-2. Gingival keratinocytes express transmembrane serine protease 2 (TMPRSS2), responsible for priming the SARS-CoV-2 spike protein. We investigated whether periodontitis increased the expression of TMPRSS2.

Methods

To investigate gene expression in periodontitis, we analyzed the expression of specific genes from (1) the Gene Expression Omnibus (GEO) dataset of 247 human gingival tissues and (2) an experimentally-induced periodontitis mouse model. Human gingival tissues with or without periodontitis were immunohistochemically stained using an anti-TMPRSS2 antibody. Analysis of the TMPRSS2 promoter was performed using a ChIP-Atlas dataset. TMPRSS2 expression was detected in cultured human keratinocytes using quantitative reverse transcription (qRT)-PCR and Western blot analysis.

Results

GEO dataset analysis and an experimentally-induced periodontitis model revealed increased expression of TMPRSS2 in periodontitis gingiva. The keratinocyte cell membrane in periodontitis gingiva was strongly immunohistochemically stained for TMPRSS2. Using ChIP-Atlas and GEO datasets, we screened for transcription factors that bind to the TMPRSS2 promoter region. We found one candidate, estrogen receptor 1 (ESR1), highly expressed in periodontitis gingiva. Analysis of the GEO dataset revealed a correlation between ESR1 and TMPRSS2 expression in gingival tissues. An ESR1 ligand induced TMPRSS2 expression in cultured keratinocytes.

Conclusions

Periodontitis increases TMPRSS2 expression in the cell membrane of gingival keratinocytes.

Exogenous interleukin-1 beta promotes the proliferation and migration of HeLa cells via the MEK/ERK signaling pathway

OBJECTIVE

Interleukin-1 beta (IL-1β) is a crucial cytokine that has been implicated in cancer and metastasis development. However, its possible mechanistic role in cervical cancer remains unclear. This study aimed to investigate the functions of exogenous IL-1β in cervical cancer cell proliferation and migration.

METHODS

HeLa cell proliferation and migration were measured using MTT and Transwell assays. A lentivirus-mediated packaging system was used to construct an IL-1β overexpressing cell line. MEK/ERK signal transduction was inhibited by pretreatment with the MEK inhibitor PD98059. qRT-PCR and Western blotting were used to test the expression of relevant genes.

RESULTS

Exogenous IL-1β promoted the proliferation and migration of HeLa cells. In addition, overexpression of IL-1β in HeLa cells promoted cell proliferation. Mechanistically, exogenous IL-1β increased the phosphorylated MEK and ERK levels in HeLa cells and the expression of JUN, RELB, and NF-κB2. Alternatively, blockade of MEK inhibited the promoting proliferation effects of IL-1β and the expression of JUN, RELB, and NF-κB2.

CONCLUSIONS

Our data suggest that exogenous IL-1β regulates HeLa cell functions by regulating the MEK/ERK signaling pathway and by targeting JUN, RELB, and NF-κB2. Our study uncovered a potential association across IL-1β, cervical tumor development, and cancer progression.

Dissection of the MKK3 Functions in Human Cancer: A Double-Edged Sword?

The role played by MKK3 in human cancer is controversial. MKK3 is an evolutionarily conserved protein kinase that activates in response to a variety of stimuli. Phosphorylates, specifically the p38MAPK family proteins, contribute to the regulation of a plethora of cellular processes such as proliferation, differentiation, apoptosis, invasion, and cell migration. Genes in carcinogenesis are classified as oncogenes and tumor suppressors; however, a clear distinction is not always easily made as it depends on the cell context and tissue specificity. The aim of this study is the examination of the potential contribution of MKK3 in cancer through a systematic analysis of the recent literature. The overall results reveal a complex scenario of MKK3’s involvement in cancer. The oncogenic functions of MKK3 were univocally documented in several solid tumors, such as colorectal, prostate cancer, and melanoma, while its tumor-suppressing functions were described in glioblastoma and gastric cancer. Furthermore, a dual role of MKK3 as an oncogene as well as tumor a suppressor has been described in breast, cervical, ovarian, liver, esophageal, and lung cancer. However, overall, more evidence points to its role as an oncogene in these diseases. This review indicates that the oncogenic and tumor-suppressing roles of MKK3 are strictly dependent on the tumor type and further suggests that MKK3 could represent an efficient putative molecular target that requires contextualization within a specific tumor type in order to adequately evaluate its potential effectiveness in designing novel anticancer therapies. 

The unfavorable clinical outcome of COVID-19 in smokers is mediated by H3K4me3, H3K9me3 and H3K27me3 histone marks

Smoking could predispose individuals to a more severe COVID-19 by upregulating a particular gene known as mdig, which is mediated through a number of well-known histone modifications. Smoking might regulate the transcription-activating H3K4me3 mark, along with the transcription-repressing H3K9me3 and H3K27me3 marks, in a way to favor SARS-CoV-2 entry by enhancing the expression of ACE2, NRP1 and NRP2, AT1R, CTSD and CTSL, PGE2 receptors 2-4, SLC6A20 and IL-6, all of which interact either directly or indirectly with important receptors, facilitating viral entry in COVID-19.

Furin-responsive triterpenine-based liposomal complex enhances anticervical cancer therapy through size modulation

The accumulation and penetration of antitumor drugs in tumor tissues are directly related to their antitumor effects. The particle size of the nanodrug delivery system is one of the most important factors for the accumulation and penetration of antitumor drugs within tumor tissues. Generally, nanodelivery systems of intermediate size (100–120 nm) are capable of efficient accumulation owing to prolonged circulation and enhanced permeability and retention (EPR) effect; however, smaller ones (20–40 nm) are effective for deep penetration within tumor tissue. Currently a conventional drug delivery system cannot possess two types of optimal sizes, simultaneously. To solve this and to enhance cervical cancer treatment, a furin-responsive triterpenine-based liposomal complex (PEGcleavable Tf-CTM/L), with Tf-CTM (transferrin-modified tripterine-loaded coix seed oil microemulsion) in core, coated with a thermo-sensitive lipid and a kind of PEG shell modified with a furin-cleavable peptide was developed to improve tumor-specific accumulation and penetration. Herein, PEGcleavable Tf-CTM/L was capable of efficient accumulation because of EPR effect. The PEG shells could timely detach under stimulation of overexpressed furin protein to solve the problem of the steric hindrance dilemma. The small-sized Tf-CTM released under stimulation of tumor microthermal environment in cervical cancer, which was efficient with regards to deep penetration at tumor sites. Notably, compared to the use of triterpenine alone, PEGcleavable Tf-CTM/L promoted anticervical efficacy and displayed diminished systemic toxicity by efficient accumulation and deep penetration of antitumor drugs within tumor tissues. Our study provides a new strategy, and holds promising potential for anticervical cancer treatment.

Proliferative Vascular Smooth Muscle Cells Stimulate Extracellular Matrix Production via Osteopontin/p38 MAPK Signaling Pathway

INTRODUCTION

Extracellular matrix disorder and cellular phenotype transformation are the major histopathological features associated with ascending aortic aneurysms. Rare studies have investigated the relationship between cellular phenotype transformation and the abnormalities of the matrix constituents. In this study, we investigated whether the cellular phenotype transformation resulted in the extracellular matrix disorder.

METHODS

Aortic samples were obtained from 20 patients undergoing operations for ascending aortic aneurysms. Control aortic samples were obtained from 15 patients who underwent coronary artery bypass graft. The protein levels of osteopontin (OPN), collagen, and elastin were examined using Western blot, and quantitative reverse transcriptase-PCR was used to analyze the mRNA expression of collagen and elastin. In vitro experiment, vascular smooth muscle cells (VSMCs) were treated with recombinant human OPN (rh-OPN) or p38 MAPK inhibitor (SB203580) to investigate whether OPN and p38 MAPK regulated the expression of collagen and elastin.

RESULTS

The protein level of OPN and collagen III increased in ascending aortic aneurysm samples, compared with controls (p < 0.05). There was no difference in the protein level of elastin between aneurysm tissues and the controls. VSMCs treated with rh-OPN increased the collagen III and elastin protein level and mRNA expression (p < 0.05). Cells treated with SB203580 decreased the collagen III and elastin protein level and mRNA expression (p < 0.05). Furthermore, VSMCs incubated with SB203580 reduced the rh-OPN-induced production of collagen III and elastin (p < 0.05).

CONCLUSION

OPN, the proliferative VSMCs maker, increased the expression of extracellular matrix. OPN/p38 MAPK signaling pathways may protect against ascending aortic aneurysm progression.

p38β - MAPK11 and its role in female cancers

Background

The p38MAPK family of Mitogen Activated Protein Kinases are a group of signalling molecules involved in cell growth, survival, proliferation and differentiation. The widely studied p38α isoform is ubiquitously expressed and is implicated in a number of cancer pathologies, as are p38γ and p38δ. However, the mechanistic role of the isoform, p38β, remains fairly elusive. Recent studies suggest a possible role of p38β in both breast and endometrial cancer with research suggesting involvement in bone metastasis and cancer cell survival. Female tissue specific cancers such as breast, endometrial, uterine and ovary account for over 3,000,000 cancer related incidents annually; advancements in therapeutics and treatment however require a deeper understanding of the molecular aetiology associated with these diseases. This study provides an overview of the MAPK signalling molecule p38β (MAPK11) in female cancers using an in-silico approach.

Methods

A detailed gene expression and methylation analysis was performed using datasets from cBioportal, CanSar and MEXPRESS. Breast, Uterine Endometrial, Cervical, Ovarian and Uterine Carcinosarcoma TCGA cancer datasets were used and analysed.

Results

Data using cBioportal and CanSAR suggest that expression of p38β is lower in cancers: BRCA, UCEC, UCS, CESC and OV compared to normal tissue. Methylation data from SMART and MEXPRESS indicate significant probe level variation of CpG island methylation status of the gene MAPK11. Analysis of the genes’ two CpG islands shows that the gene was hypermethylated in the CpG1 with increased methylation seen in BRCA, CESC and UCEC cancer data sets with a slight increase of expression recorded in cancer samples. CpG2 exhibited hypomethylation with no significant difference between samples and high levels of expression. Further analysis from MEXPRESS revealed no significance between probe methylation and altered levels of expression. In addition, no difference in the expression of BRCA oestrogen/progesterone/HER2 status was seen.

Conclusion

This data provides an overview of the expression of p38β in female tissue specific cancers, showing a decrease in expression of the gene in BRCA, UCEC, CESC, UCS and OV, increasing the understanding of p38β MAPK expression and offering insight for future in-vitro investigation and therapeutic application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00834-9.

Tumor-derived osteopontin drives the resident fibroblast to myofibroblast differentiation through Twist1 to promote breast cancer progression

Tumor-stroma interactions are important determinants for the disease course in cancer. While stromal influence has been known to often play a tumor-promoting role, incomplete mechanistic insight into this phenomenon has prevented its therapeutic targeting. Stromal fibroblasts can be activated by tumor cells to differentiate into cancer-associated fibroblasts (CAFs), that exhibit the traits of myofibroblasts, and in turn, they increase cancer aggressiveness. Here, we report the crosstalk between the cancer cells and stromal fibroblasts that leads to tumor progression. The process is initiated by secretion of a chemokine like protein, osteopontin (OPN) from the cancer cells that differentiates the fibroblasts to myofibroblasts. Tumor-derived OPN achieves this transition by engaging CD44 and αvβ3 integrins on the fibroblast surface, which mediates signaling via Akt and ERK to induce Twist1-dependent gene expression. The OPN-driven CAFs then secrete CXCL12, which in turn triggers epithelial to mesenchymal transition (EMT) in the tumor cells. OPN, produced by the cancer cells, and CXCL12, secreted by activated fibroblasts, are necessary and sufficient to perpetuate the crosstalk. Knocking out OPN in carcinogen-induced mammary tumors or knocking down OPN in cancer cells and fibroblast co-implanted xenografts abrogates myofibroblast differentiation, Twist1, and CXCL12 expression. OPN expression is correlated with CAF-specific gene signature as shown by breast tumor tissue microarray consisting of 100 patient specimens. Bioinformatics analyses have confirmed that the expression of OPN is significantly correlated with the expression of myofibroblast-specific markers as demonstrated in human breast carcinoma dataset of 2509 patients. Our findings describe OPN and CXCL12 act as compelling targets to curb the tumor-promoting features of the stromal components and further suggested that OPN-regulated CXCL12 network might act as potential therapeutic target for the management of CAF-mediated breast cancer progression.

Cellular CARD11 Inhibits the Fusogenic Activity of Newcastle Disease Virus via CBM Signalosome-Mediated Furin Reduction in Chicken Fibroblasts

Newcastle disease virus (NDV) causes an infectious disease that poses a major threat to poultry health. Our previous study identified a chicken brain-specific caspase recruitment domain-containing protein 11 (CARD11) that was upregulated in chicken neurons and inhibited NDV replication. This raises the question of whether CARD11 plays a role in inhibiting viruses in non-neural cells. Here, chicken fibroblasts were used as a non-neural cell model to investigate the role. CARD11 expression was not significantly upregulated by either velogenic or lentogenic NDV infection in chicken fibroblasts. Viral replication was decreased in DF-1 cells stably overexpressing CARD11, while viral growth was significantly increased in the CARD11-knockdown DF-1 cell line. Moreover, CARD11 colocalized with the viral P protein and aggregated around the fibroblast nucleus, suggesting that an interaction existed between CARD11 and the viral P protein; this interaction was further examined by suppressing viral RNA polymerase activity by using a minigenome assay. Viral replication was inhibited by CARD11 in fibroblasts, and this result was consistent with our previous report in chicken neurons. Importantly, CARD11 was observed to reduce the syncytia induced by either velogenic virus infection or viral haemagglutinin-neuraminidase (HN) and F cotransfection in fibroblasts. We found that CARD11 inhibited the expression of the host protease furin, which is essential for cleavage of the viral F protein to trigger fusogenic activity. Furthermore, the CARD11-Bcl10-MALT1 (CBM) signalosome was found to suppress furin expression, which resulted in a reduction in the cleavage efficiency of the viral F protein to further inhibit viral syncytia. Taken together, our findings mainly demonstrated a novel CARD11 inhibitory mechanism for viral fusogenic activity in chicken fibroblasts, and this mechanism explains the antiviral roles of this molecule in NDV pathogenesis.

Complementary Chinese Herbal Medicine Therapy Improves Survival in Patients With Pemphigus: A Retrospective Study From a Taiwan-Based Registry

Pemphigus is a life-threatening and skin-specific inflammatory autoimmune disease, characterized by intraepidermal blistering between the mucous membranes and skin. Chinese herbal medicine (CHM) has been used as an adjunct therapy for treating many diseases, including pemphigus. However, there are still limited studies in effects of CHM treatment in pemphigus, especially in Taiwan. To more comprehensively explore the effect of long-term CHM treatment on the overall mortality of pemphigus patients, we performed a retrospective analysis of 1,037 pemphigus patients identified from the Registry for Catastrophic Illness Patients database in Taiwan. Among them, 229 and 177 patients were defined as CHM users and non-users, respectively. CHM users were young, predominantly female, and had a lesser Charlson comorbidity index (CCI) than non-CHM users. After adjusting for age, sex, prednisolone use, and CCI, CHM users had a lower overall mortality risk than non-CHM users (multivariate model: hazard ratio (HR): 0.422, 95% confidence interval (CI): 0.242–0.735, p = 0.0023). The cumulative incidence of overall survival was significantly higher in CHM users than in non-users (p = 0.0025, log rank test). Association rule mining and network analysis showed that there was one main CHM cluster with Qi–Ju–Di–Huang–Wan (QJDHW), Dan–Shen (DanS; Radix Salviae miltiorrhizae; Salvia miltiorrhiza Bunge), Jia–Wei–Xiao–Yao-–San (JWXYS), Huang–Lian (HL; Rhizoma coptidis; Coptis chinensis Franch.), and Di–Gu–Pi (DGP; Cortex lycii; Lycium barbarum L.), while the second CHM cluster included Jin–Yin–Hua (JYH; Flos lonicerae; Lonicera hypoglauca Miq.) and Lian–Qiao (LQ; Fructus forsythiae; Forsythia suspensa (Thunb.) Vahl). In Taiwan, CHMs used as an adjunctive therapy reduced the overall mortality to approximately 20% among pemphigus patients after a follow-up of more than 6 years. A comprehensive CHM list may be useful in future clinical trials and further scientific investigations to improve the overall survival in these patients.

The Potential Role of Osteopontin and Furin in Worsening Disease Outcomes in COVID-19 Patients with Pre-Existing Diabetes

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the ongoing coronavirus disease 2019 (COVID-19) pandemic, with more than 50 million cases reported globally. Findings have consistently identified an increased severity of SARS-CoV-2 infection in individuals with diabetes. Osteopontin, a cytokine-like matrix-associated phosphoglycoprotein, is elevated in diabetes and drives the expression of furin, a proprotein convertase implicated in the proteolytic processing and activation of several precursors, including chemokines, growth factors, hormones, adhesion molecules, and receptors. Elevated serum furin is a signature of diabetes mellitus progression and is associated with a dysmetabolic phenotype and increased risk of diabetes-linked premature mortality. Additionally, furin plays an important role in enhancing the infectivity of SARS-CoV-2 by promoting its entry and replication in the host cell. Here, we hypothesize that diabetes-induced osteopontin and furin protein upregulation results in worse outcomes in diabetic patients with SARS-CoV-2 infection owing to the roles of these protein in promoting viral infection and increasing metabolic dysfunction. Thus, targeting the osteopontin-furin axis may be a plausible strategy for reducing mortality in SARS-CoV-2 patients with diabetes.

Osteopontin level and promoter polymorphism in patients with metastatic breast cancer

Background

Cancer initiation typically occurs when a proto-oncogene's coding region undergoes mutation, resulting in uncontrollable cell growth and division, or when a tumour suppressor gene's coding region is affected by a mutation that inhibits activity of the resulting gene product. The pathophysiologic result is, respectively, exaggerated cell-cycle growth or deficient programmed cell death. Osteopontin (opn) is an integrin-binding phosphoprotein that is expressed on the surface of normal cells. Osteopontin has a major role in diverse tumour components, especially those implicated in invasion and metastasis. In the present study, we aimed to illustrate the value of opn as a possible contributor in breast cancer (bca).

Methods

This prospective study included 115 patients newly diagnosed with bca and distant metastasis who were recruited from the Oncology Center, Mansoura University, and the Department of Clinical Oncology and Nuclear Medicine, Mansoura University Hospital, Egypt. The patients recruited had been diagnosed with disseminated visceral metastasis (visceral crisis), with or without bone metastasis; patients with cranial metastasis were excluded from the study. All patients received first-line chemotherapy with docetaxel 75 mg/m2 plus cisplatin 75 mg/m2 or carboplatin 6 auc (area under the curve) on day 1 every 21 days for a maximum of 6 cycles or till development of toxicity. Trastuzumab (in cases of her2-positive disease) was given whenever possible (if government assistance or personal finances permitted). Serum levels of opn were assessed by enzyme-linked immunosorbent assay (elisa) before treatment was started. A group of 30 matched healthy women whose median serum opn level was 15 ng/dL were included, and that level was therefore defined as the cut-off value. In addition, opn gene mutation was determined by polymerase chain reaction (pcr). Correlations of pretreatment serum opn and opn gene mutation with various patient clinicopathologic variables, response to the treatment, progression-free survival (pfs), and overall survival (os) were assessed.

Results

Mean serum opn was highest in her2-amplified bca (64.4 ± 42.3 ng/dL), and then in triple-negative bca (55.9 ± 34.7 ng/dL), followed by the luminal B and A subtypes (38.4 ± 33.1 ng/dL and 36.3 ± 32.2 ng/dL respectively, p = 0.017). Testing by pcr revealed that opn gene mutation was highest in triple-negative bca (85% opn mutant vs. 15% non-mutant), and then in her2-overexpressed bca (80% opn mutant vs. 20% non-mutant), followed by luminal B bca (61.9% opn mutant vs. 38.1% non-mutant); the least expression was detected in luminal A bca (57.9% opn mutant vs. 42.1% non-mutant). Interestingly, patients with high serum opn and opn gene mutation experienced both poor pfs (median: 12 months vs. 14 months; p = 0.001) and poor os (median: 14 months vs. 18 months; p = 0.001). Moreover, participants with opn gene mutation experienced a poor response: of those with progressive disease, 74% had opn mutation and 26% had unmutated opn (p = 0.04). Additionally, high pretreatment serum opn was correlated with poor treatment response: 49.1 ± 33.8 ng/dL in patients with progressive disease and 35.5 ± 34.3 ng/dL in those who achieved a complete response, a partial response, or stable disease (p = 0.05). Strong concordance was found between high serum opn and opn gene mutation in 69 tumours (79.3%), and strong concordance was detected between normal or low serum opn and non-mutant opn in 28 tumours (60.8%).

Conclusions

The current prospective work helps to highlight opn as a valid prognostic biomarker for patients with metastatic bca and reveals that high pretreatment serum opn and opn gene mutation are both strongly linked with poor response and survival. Concordance between elisa and pcr results indicates that either method can be used for the evaluation of opn. Increased opn gene mutation in triple-negative bca could assist in tailoring the treatment response in this very aggressive tumour subtype and could be considered a targetable molecule in future studies.

A five-mRNA signature associated with post-translational modifications can better predict recurrence and survival in cervical cancer

High mortality of patients with cervical cancer (CC) stresses the imperative of prognostic biomarkers for CC patients. Additionally, the vital status of post‐translational modifications (PTMs) in the progression of cancers has been reported by numerous researches. Therefore, the purpose of this research was to dig a prognostic signature correlated with PTMs for CC. We built a five‐mRNA (GALNTL6, ARSE, DPAGT1, GANAB and FURIN) prognostic signature associated with PTMs to predict both disease‐free survival (DFS) (hazard ratio [HR] = 3.967, 95% CI = 1.985‐7.927; P < .001) and overall survival (HR = 2.092, 95% CI = 1.138‐3.847; P = .018) for CC using data from The Cancer Genome Atlas database. Then, the robustness of the signature was validated using GSE44001 and the Human Protein Atlas (HPA) database. CIBERSORT algorithm analysis displayed that activated CD4 memory T cell was also an independent indicator for DFS (HR = 0.426, 95% CI = 0.186‐0.978; P = .044) which could add additional prognostic value to the signature. Collectively, the PTM‐related signature and activated CD4 memory T cell can provide new avenues for the prognostic predication of CC. These findings give further insights into effective treatment strategies for CC, providing opportunities for further experimental and clinical validations.

Proprotein convertases: Key players in inflammation-related malignancies and metastasis

Many cancers occur from locations of inflammation due to chronic irritation and/or infection. Tumor microenvironment contains various different inflammatory cells and mediators that orchestrate diverse neoplastic processes, including proliferation, survival, adhesion and migration. In parallel, tumor cells have adapted some of the signaling molecules used by inflammatory cells, such as selectins and chemokines as well as their receptors for invasion, extravasation and subsequently metastasis. Expression and/or activation of the majority of these molecules is mediated by the proprotein convertases (PCs); proteases expressed by both tumor cells and inflammatory cells. This review analyzes the potential role of these enzymatic system in inflammation-associated cancer impacting on the malignant and metastatic potential of cancer cells, describing the possible use of PCs as a new anti-inflammatory therapeutic approach to tumor progression and metastasis.

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Proteins maturation by the proprotein convertases plays important role in inflammation-related cancer and metastasis.

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Protein precursors require the proprotein convertases for the induction of inflammation.

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Understanding of the molecular mechanism linking the proprotein convertases to inflammation will allow novel therapies.

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Inhibitors of the proprotein convertases constitute great potential for cancer treatment.

SPP1 inhibition improves the cisplatin chemo-sensitivity of cervical cancer cell lines

PURPOSE

Cisplatin (DDP)-based chemotherapy is a standard strategy for cervical cancer, while chemoresistance remains a huge challenge. In the present study, we aimed to explore the effects of SPP1 on the proliferation and apoptosis rate of the HeLa cervical cancer cell line with cisplatin (DDP) resistance.

METHODS

Microarray analysis was employed to select differentially expressed genes in cervical cancer tissues and adjacent tissues. Then, we established a DDP-resistant HeLa cell line (res-HeLa). Western blotting was used to detect SPP1 expression in both tissue and cells. After the transfection with si-SPP1 and pcDNA3.1-SPP1, colony formation and MTT assays were applied to detect cell proliferation changes. Flow cytometry was employed to detect the cell apoptosis rate. Western blotting was performed to verify the activation of PI3K/Akt signal pathway proteins related to DDP resistance.

RESULTS

SPP1 was overexpressed in cervical cancer tissues and cell lines. Compared to normal HeLa cells, expression of SPP1 was significantly enhanced in res-HeLa cells. SPP1 knockdown resulted in repressed proliferation and enhanced apoptosis of res-HeLa cells, which could be reversed by SPP1 overexpression in HeLa cells. Additionally, downregulation of SPP1 improved the DDP sensitivity of HeLa by inhibiting the PI3K/Akt signaling pathway.

CONCLUSION

SPP1 inhibition could suppress proliferation, induce apoptosis and increase the DDP chemo-sensitivity of HeLa cells.

RIT1 suppresses esophageal squamous cell carcinoma growth and metastasis and predicts good prognosis

Ras-like without CAAX1 (RIT1) protein is a member of Ras family, which plays critical roles in signaling pathways and cellular process regulation. However, the role of RIT1 in esophageal squamous cell carcinoma (ESCC) is unclear. In this study, we found that the expression of RIT1 is downregulated in ESCC compared to corresponding non-tumor tissues. The low-level expression of RIT1 was correlated with poorer prognosis. Then we showed that RIT1 inhibited proliferation, invasion, and migration of ESCC cells, and silencing RIT1 by shRNA promoted tumorigenicity and metastasis in nude mice. We further demonstrated that RIT1 inhibited the malignant behaviors of ESCC through inhibiting the PI3K/AKT and MAPK pathway and epithelial–mesenchymal transition in ESCC cells. Our study also revealed that RIT1 increased drug sensitivity to cisplatin (CDDP), and this function could be carried out through downregulating stemness of ESCC. In conclusion, our study indicates for the first time that RIT1 displays tumor-suppressing functions in ESCC, and these functions were carried out by inhibiting MAPK and PI3K/AKT signaling pathway, inhibiting EMT, and downregulating cancer stemness of ESCC cells.

Pharmacological targeting of p38 MAP-Kinase 6 (MAP2K6) inhibits the growth of esophageal adenocarcinoma

Drug repurposing with a better understanding of the underlying mechanism has provided new avenues to find treatment for malignancies. Esophageal adenocarcinoma (EAC) is a rapidly increasing cancer with a dismal 5-year survival rate of <15%. Lack of efficient treatment options contributes to the high mortality rate of EAC. To find new therapy against EAC we performed unbiased drug screening of an FDA-approved drug library and identified that the cardiac glycosides including Ouabain, Digoxin and Digitoxin efficiently inhibit the proliferation of EAC cell lines (OE33 and OE19) both in vitro and in vivo. RNA-Sequencing analysis combined with RNAi screening revealed that Ouabain suppresses the proliferation of EAC cells through downregulation of p38 MAP-Kinase 6 (MAP2K6, also known as MKK6). Consistently, shRNA-mediated knockdown of MKK6 reduced the proliferation of EAC cells and tumor growth. Further analysis demonstrated that MKK6 inhibition leads to the reduced levels of the transcription factor SOX9. In line with this finding, deletion of SOX9 with CRISPR/Cas9 resulted in decreased proliferation of EACs in 3D organoid culture and reduced tumor growth. Together these findings establish a druggable axis that can be harnessed for therapeutic gain against EAC.

Insights of Crosstalk between p53 Protein and the MKK3/MKK6/p38 MAPK Signaling Pathway in Cancer

TP53 is universally recognized as a pivotal protein in cell-cycle fate and apoptotic induction and, unsurprisingly, it is one of the most commonly hijacked control mechanisms in cancer. Recently, the kinase MKK3 emerged as a potential therapeutic target in different types of solid tumor being linked to mutant p53 gain-of-function. In this review, we summarize the delicate relationship among p53 mutational status, MKK3/MKK6 and the downstream activated master kinase p38MAPK, dissecting a finely-tuned crosstalk, in a potentially cell-context dependent scenario that urges towards a deeper characterization of the different molecular players involved in this signaling cascade and their interactions.

Cancer stem cells (CSCs), cervical CSCs and targeted therapies

Accumulating evidence has shown that cancer stem cells (CSCs) have a tumour-initiating capacity and play crucial roles in tumour metastasis, relapse and chemo/radio-resistance. As tumour propagation initiators, CSCs are considered to be promising targets for obtaining a better therapeutic outcome. Cervical carcinoma is the most common gynaecological malignancy and has a high cancer mortality rate among females. As a result, the investigation of cervical cancer stem cells (CCSCs) is of great value. However, the numbers of cancer cells and corresponding CSCs in malignancy are dynamically balanced, and CSCs may reside in the CSC niche, about which little is known to date. Therefore, due to their complicated molecular phenotypes and biological behaviours, it remains challenging to obtain “purified” CSCs and continuously culture CSCs for further in vitro studies without the cells losing their stem properties. At present, CSC-related markers and functional assays are used to purify, identify and therapeutically target CSCs both in vitro and in vivo. Nevertheless, CSC-related markers are not universal to all tumour types, although some markers may be valid in multiple tumour types. Additionally, functional identifications based on CSC-specific properties are usually limited in in vivo studies. Furthermore, an optimal method for identifying potential CCSCs in CCSC studies has not been previously published, and these techniques are currently of great importance. This article updates our knowledge on CSCs and CCSCs, reviews potential stem cell markers and functional assays for identifying CCSCs, and describes the potential of targeting CCSCs in the treatment of cervical carcinoma.

The role of osteopontin in the progression of solid organ tumour

Osteopontin (OPN) is a bone sialoprotein involved in osteoclast attachment to mineralised bone matrix, as well as being a bone matrix protein, OPN is also a versatile protein that acts on various receptors which are associated with different signalling pathways implicated in cancer. OPN mediates various biological events involving the immune system and the vascular system; the protein plays a role in processes such as immune response, cell adhesion and migration, and tumorigenesis. This review discusses the potential role of OPN in tumour cell proliferation, angiogenesis and metastasis, as well as the molecular mechanisms involved in these processes in different cancers, including brain, lung, kidney, liver, bladder, breast, oesophageal, gastric, colon, pancreatic, prostate and ovarian cancers. The understanding of OPN’s role in tumour development and progression could potentially influence cancer therapy and contribute to the development of novel anti-tumour treatments.

Epoxyazadiradione suppresses breast tumor growth through mitochondrial depolarization and caspase-dependent apoptosis by targeting PI3K/Akt pathway

Background

Breast cancer is one of the most commonly diagnosed invasive cancers among women around the world. Among several subtypes, triple negative breast cancer (TNBC) is highly aggressive and chemoresistant. Treatment of TNBC patients has been challenging due to heterogeneity and devoid of well-defined molecular targets. Thus, identification of novel effective and selective agents against TNBC is essential.

Methods

We used epoxyazadiradione to assess the cell viability, mitochondrial potential, ROS level, cell migration, apoptosis and protein expression in cell culture models of TNBC MDA-MB-231 and ER+ MCF-7 breast cancer cells. The molecular mechanism was examined in two different type of breast cancer cells in response to epoxyazadiradione. We have also analyzed the effect of epoxyazadiradione on breast tumor growth using in vivo mice model.

Results

In this study, we for the first time investigated that out of 10 major limonoids isolated from Azadirachta indica, epoxyazadiradione exhibits most potent anti-cancer activity in both TNBC and ER+ breast cancer cells. Epoxyazadiradione induces apoptosis and inhibits PI3K/Akt-mediated mitochondrial potential, cell viability, migration and angiogenesis. It also inhibits the expression of pro-angiogenic and pro-metastatic genes such as Cox2, OPN, VEGF and MMP-9 in these cells. Furthermore, epoxyazadiradione attenuates PI3K/Akt-mediated AP-1 activation. Our in vivo data revealed that epoxyazadiradione suppresses breast tumor growth and angiogenesis in orthotopic NOD/SCID mice model.

Conclusion

Our findings demonstrate that epoxyazadiradione inhibits PI3K/Akt-dependent mitochondrial depolarisation, induces apoptosis and attenuates cell migration, angiogenesis and breast tumor growth suggesting that this compound may act as a potent therapeutic agent for the management of breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3876-2) contains supplementary material, which is available to authorized users.

Osteopontin is a multi-faceted pro-tumorigenic driver for central nervous system lymphoma

Osteopontin (OPN) is the most upregulated gene in primary central nervous system lymphoma (PCNSL) compared to non-CNS diffuse large B cell lymphoma (DLBCL). We show here that OPN is a key mediator of intracerebral tumor growth, invasion, and dissemination in CNS lymphoma, and that these effects depend upon activation of NF-κB. We further show that activation of NF-κB by OPN occurs through a unique mechanism in which intracellular OPN (iOPN) causes transcriptional downregulation of the NF-κB inhibitors, A20/TNFAIP3 and ABIN1/TNIP1, and secretory OPN (sOPN) promotes receptor-mediated activation of NF-κB. We also identify NF-κB-mediated induction of matrix metalloproteinase-8 (MMP-8) as a specific feature of OPN-mediated tissue invasion. These results implicate OPN as a candidate for development of targeted therapy for patients with PCNSL.

The Roles of Matricellular Proteins in Oncogenic Virus-Induced Cancers and Their Potential Utilities as Therapeutic Targets

Matricellular proteins differ from other classical extracellular matrix proteins; for instance, they are transiently expressed as soluble proteins rather than being constitutively expressed in pathological conditions, such as acute viral infections. Accumulating studies have revealed that matricellular proteins, including osteopontin and tenascin-C, both of which interact with integrin heterodimers, are involved in inflammatory diseases, autoimmune disorders, and cancers. The concentrations of these matricellular proteins are elevated in the plasma of patients with certain types of cancers, indicating that they play important roles in oncogenesis. Chronic viral infections are associated with certain cancers, which are distinct from non-viral cancers. Viral oncogenes play critical roles in the development and progression of such cancers. It is vital to investigate the mechanisms of tumorigenesis and, particularly, the mechanism by which viral proteins induce tumor progression. Viral proteins have been shown to influence not only the viral-infected cancer cells, but also the stromal cells and matricellular proteins that constitute the extracellular matrix that surrounds tumor tissues. In this review, we summarize the recent progress on the involvement of matricellular proteins in oncogenic virus-induced cancers to elucidate the mechanism of oncogenesis and consider the possible role of matricellular proteins as therapeutic targets in virus-induced cancers.

p38 predicts depression and poor outcome in esophageal cancer

p38 mitogen-activated protein kinase (MAPK) signaling has been implicated in the cancer development and progression. However, the precise mechanism of this association remains unknown. The aim of the present study was to evaluate the association between p38 and cancer progression, including investigations into the effects on cell proliferation, resistance to thalidomide, indoleamine 2,3-dioxygenase (IDO) expression and prognosis in patients with esophageal cancer. The present retrospective study included patients with stage I–III esophageal cancer. A total of 228 patients with esophageal cancer were recruited to analyze the expression of phosphorylated (p)-p38 and IDO in tumor, and normal tissues through immunohistochemistry. Depression status was measured using the Zung Self-Rating Depression Scale. P38 cDNA was transfected into esophageal cancer cells to assess tumor cell viability, sensitivity to thalidomide treatment and IDO gene expression. Western blotting and flow cytometry was used to analyze protein expression alterations, and apoptosis in esophageal cancer cells. P-p38 protein was expressed in 68.9% of cancer tissues, and was significantly associated with depressive symptoms, tumor recurrence and poor survival of patients. In vitro experiments revealed that the expression of p-p38 induced esophageal cancer Eca-109 and TE-1 cell viability, and resistance to thalidomide treatment, as well as in the expression of IDO without the application of lipopolysaccharides. Further follow-up of patients revealed that depression was also an independent factor for early recurrence and overall survival rate. Altered p38 MAPK expression was associated with poor outcome in patients with esophageal cancer. p38 may be a potential biomarker for the prediction of depressive symptoms and prognosis in patients with esophageal cancer.

Crosstalk between Signaling Pathways in Pemphigus: A Role for Endoplasmic Reticulum Stress in p38 Mitogen-Activated Protein Kinase Activation?

Pemphigus consists of a group of chronic blistering skin diseases mediated by autoantibodies (autoAbs). The dogma that pemphigus is caused by keratinocyte dissociation (acantholysis) as a distinctive and direct consequence of the presence of autoAb targeting two main proteins of the desmosome—desmoglein (DSG) 1 and/or DSG3—has been put to the test. Several outside-in signaling events elicited by pemphigus autoAb in keratinocytes have been described, among which stands out p38 mitogen-activated protein kinase (p38 MAPK) engagement and its apoptotic effect on keratinocytes. The role of apoptosis in the disease is, however, debatable, to an extent that it may not be a determinant event for the occurrence of acantholysis. Also, it has been verified that compromised DSG trans-interaction does not lead to keratinocyte dissociation when p38 MAPK is inhibited. These examples of conflicting results have been followed by recent work revealing an important role for endoplasmic reticulum (ER) stress in pemphigus’ pathogenesis. ER stress is known to activate the p38 MAPK pathway, and vice versa. However, this relationship has not yet been studied in the context of activated signaling pathways in pemphigus. Therefore, by reviewing and hypothetically connecting the role(s) of ER stress and p38 MAPK pathway in pemphigus, we highlight the importance of elucidating the crosstalk between all activated signaling pathways, which may in turn contribute for a better understanding of the role of apoptosis in the disease and a better management of this life-threatening condition.

Matrine inhibits the metastatic properties of human cervical cancer cells via downregulating the p38 signaling pathway

Matrine is a traditional Chinese herbal medicine that shows antitumor efficacy for many types of cancer. The present study evaluated the antitumor efficacy of matrine on cervical cancer and to investigate the underlying mechanisms. We performed MTT assays, and in vitro invasion and migration assays, and P1 L6 found that matrine significantly inhibited cervical cancer cell growth by inducing apoptosis, and suppressed the invasion and migration ability of cervical cancer cells in vitro in a concentration-dependent manner. Mechanistically, we found that matrine decreased the expression and activity of the extracellular matrix factors, matrix metalloproteinases-2 (MMP-2) and MMP-9 via the suppression of p38 signaling pathway. In addition, when cervical cancer cells were grown as xenografts in nude mice, intraperitoneal (i.p.) injection of matrine induced a significant dose-dependent decrease in tumor growth. Taken together, these findings suggest that a potential mechanism by which matrine inhibits the growth and metastasis of cervical cancer through downregulating the p38 signaling pathway.

The proprotein convertase furin in tumour progression

Proprotein convertases are proteases that have been implicated in the activation of a wide variety of proteins. These proteins are generally synthesised as precursor proteins and require limited proteolysis for conversion into their mature bioactive counterparts. Many of these proteins, including metalloproteases, growth factors and their receptors or adhesion molecules, have been shown to facilitate tumour formation and progression. Hence, this review will focus on the proprotein convertase furin and its role in cancer. The expression of furin has been confirmed in a large spectrum of cancers such as head and neck squamous cell carcinoma, breast cancer and rhabdomyosarcoma. Functional studies modulating furin activity uncovered its importance for the processing of many cancer-related substrates and strongly indicate that high furin activity promotes the malignant phenotype of cancer cells. In this review, we summarise the expression and function of furin in different cancer types, discuss its role in processing cancer-related proproteins and give examples of potential therapeutic approaches that take advantage of the proteolytic activity of furin in cancer cells.

Suppression of osteopontin inhibits chemically induced hepatic carcinogenesis by induction of apoptosis in mice

Previous clinical reports have found elevated osteopontin (OPN) levels in tumor tissues to be indicative of greater malignancy in human hepatocellular carcinoma (HCC). However, the role of OPN on carcinogenesis and its underlying mechanism remain unclear. In the present study, we investigated the oncogenic role of OPN in diethylnitrosamine (DEN)-induced hepatic carcinogenesis in mice. The overall incidence of hepatic tumors at 36 weeks was significantly lower in OPN knockout (KO) mice than in wild-type (WT) mice. Apoptosis was significantly enhanced in OPN KO mice, and was accompanied by the downregulation of epidermal growth factor receptor (EGFR). In the in vitro study, OPN suppression also led to lower mRNA and protein levels of EGFR associated with the downregulation of c-Jun in Hep3B and Huh7 human HCC cells lines, which resulted in increased apoptotic cell death in both cell lines. Moreover, a positive correlation was clearly identified between the expression of OPN and EGFR in human HCC tissues. These data demonstrate that the OPN deficiency reduced the incidence of chemically induced HCC by suppressing EGFR-mediated anti-apoptotic signaling. An important implication of our findings is that OPN positively contributes to hepatic carcinogenesis.

Tumor-derived osteopontin isoforms cooperate with TRP53 and CCL2 to promote lung metastasis

The lungs are ubiquitous receptacles of metastases originating from various bodily tumors. Although osteopontin (SPP1) has been associated with tumor dissemination, the role of its isoforms in lung-directed metastasis is incompletely understood. We employed syngeneic mouse models of spontaneous and induced lung-targeted metastasis in C57BL/6 mice competent and deficient in both Spp1 alleles. Tumor-derived osteopontin expression was modulated using either stable anti-Spp1 RNA interference, or forced overexpression of intracellular and secreted Spp1 isoforms. Identified osteopontin's downstream partners were validated using lung adenocarcinoma cells conditionally lacking the Trp53 gene and Ccr2-deficient mice. We determined that host-derived osteopontin was dispensable for pulmonary colonization by different tumor types. Oppositely, tumor-originated intracellular osteopontin promoted tumor cell survival by preventing tumor-related protein 53-mediated apoptosis, while the secretory osteopontin functioned in a paracrine mode to accelerate lung metastasis by enhancing tumor-derived C-C-motif chemokine ligand 2 signaling to cognate host receptors. As new ways to target osteopontin signaling are becoming available, the cytokine may constitute an important therapeutic target against pulmonary involvement by cancers of other organs.

Role of osteopontin in lung cancer evolution and heterogeneity

Patients with lung cancer still have high mortality, recurrence rate after adjuvant treatment, and poor five-year survival rates, despite of advances in multidisciplinary anti-cancer therapies, e.g. chemotherapy, radiotherapy and targeted therapies, It depends upon the presence of intratumoral heterogeneity and complexity of lung cancer. There is growing evidence to suggest that osteopontin (OPN) may play a critical role in tumor progression and metastasis. The present review briefly describes the structure and molecular biology of OPN, highlights the role of OPN in the development and metastasis of lung cancer, and summarizes potential mechanisms of OPN heterogeneity in tumor to underline some of these inconsistencies. The article will emphasize the importance to understand the role of OPN in cancer evolution and heterogeneity and explore the potential of OPN as a therapeutic target.

Notch1-MAPK Signaling Axis Regulates CD133+ Cancer Stem Cell-Mediated Melanoma Growth and Angiogenesis

Functional characterization and understanding of the intricate signaling mechanisms in stem-like cells is crucial for the development of effective therapies in melanoma. We have studied whether melanoma cells are phenotypically distinct and hierarchically organized according to their tumorigenic nature. We report that melanoma-specific CD133⁺ cancer stem cells exhibit increased tumor-initiating potential, tumor-endothelial cell interaction, and lung metastasis. These cells are able to transdifferentiate into an endothelial-like phenotype when cultured under endothelial differentiation-promoting conditions. Mechanistically, Notch1 upregulates mitogen-activated protein kinase activation through CD133, which ultimately controls vascular endothelial growth factor and matrix metalloproteinase expression in CD133⁺ stem cells leading to melanoma growth, angiogenesis, and lung metastasis. Blockade or genetic ablation of Notch1 and mitogen-activated protein kinase pathways abolishes melanoma cell migration and angiogenesis. Chromatin immunoprecipitation and reporter assays revealed that Notch1 intracellular domain regulates CD133 expression at the transcriptional level. Andrographolide inhibits Notch1 intracellular domain expression, Notch1 intracellular domain-dependent CD133-mediated mitogen-activated protein kinase and activator protein-1 activation, and epithelial to mesenchymal-specific gene expression, ultimately attenuating melanoma growth and lung metastasis. Human malignant melanoma specimen analyses revealed a strong correlation between Notch1 intracellular domain, CD133, and p-p38 mitogen-activated protein kinase expression and malignant melanoma progression. Thus, targeting Notch1 and its regulated signaling network may have potential therapeutic implications for the management of cancer stem cell-mediated melanoma progression.

PACE4 inhibitors and their peptidomimetic analogs block prostate cancer tumor progression through quiescence induction, increased apoptosis and impaired neovascularisation

Prostate cancer is the leading cancer in North American men. Current pharmacological treatments are limited to anti-androgen strategies and the development of new therapeutic approaches remains a challenge. As a fundamentally new approach, we propose the inhibition of PACE4, a member of the proprotein convertases family of enzymes, as a therapeutic target in prostate cancer. We developed an inhibitor named the Multi-Leu peptide, with potent in vitro anti-proliferative effects. However, the Multi-Leu peptide has not been tested under in vivo conditions and its potency under such conditions is most likely limited, due to the labile characteristics of peptides in general. Using a peptidomimetic approach, we modified the initial scaffold, generating the analog Ac-[DLeu]LLLRVK-Amba, which demonstrates increased inhibitory potency and stability. The systemic administration of this peptidomimetic significantly inhibits tumor progression in the LNCaP xenograft model of prostate cancer by inducing tumor cell quiescence, increased apoptosis and neovascularization impairment. Pharmacokinetic and biodistribution profiles of this inhibitor confirm adequate tumor delivery properties of the compound. We conclude that PACE4 peptidomimetic inhibitors could result in stable and potent drugs for a novel therapeutic strategy for prostate cancer.

Acylglycerol kinase is over-expressed in early-stage cervical squamous cell cancer and predicts poor prognosis

Acylglycerol kinase (AGK) had been shown to contribute to cancer progression and unfavorable clinical outcomes of patients. Our study aimed to investigate the expression pattern and clinical significance of AGK in patients with early-stage cervical squamous cell cancer (CSCC). The protein and messenger RNA (mRNA) expression of AGK was analyzed in six cervical cancer cell lines and four paired early-stage CSCC specimens and normal cervical tissues (NCT), using Western blotting and real-time PCR (RT-PCR). And we investigated the AGK protein expression in paraffin-embedded specimens from 140 patients with early-stage CSCC and 30 cases of NCT by immunohistochemistry (IHC). Statistical analyses were performed to evaluate the clinicopathological significance of AGK expression. The expressions of AGK protein and mRNA were significantly up-regulated in cervical cancer cell lines and cancer tissues. IHC analyses revealed that AGK was highly expressed in 93 (66.4 %) of 140 early-stage CSCC specimens, but in none of the NCT. Moreover, AGK expression in early-stage CSCC was significantly correlated with tumor stage (P < 0.001), tumor size (P < 0.001), and tumor type (P < 0.001). Early-stage CSCC patients with high AGK expression level had shorter progress-free survival (PFS) and overall survival (OS) time compared with patients with low AGK expression levels. Univariate and multivariate analyses identified AGK expression level as an independent prognostic factor for survival of early-stage CSCC patients. We showed that AGK was over-expressed in cervical cancer cell lines and clinical tissues, and over-expression of AGK was associated with poor survival outcomes of early-stage CSCC patients. AGK can be used as an independent prognostic marker for early-stage CSCC.

[Advances in Research of Osteopontion and Its Receptor CD44v in Tumor Invasion and Metastasis]

Osteopontin (OPN) is a multifunctional, extracellular matrix-associated, secretory, glyco-protein. It can be used as an adhesion protein involved in tumor cell adhesion,migration; but also as a cytokine, promoting tumor angiogenesis, evading immune surveillance and inhibiting cellular apoptosis. CD44v glycoprotein, is one of the cell surface adhesion molecule that mediates cell-matrix and cell-cell interactions. Extensive research has suggested the important role of OPN in regulating signaling pathways that contribute to tumor progression and metastasis, and the serum level is associated with the prognosis of various malignancies. Therefore, clarifying OPN in the molecular mechanisms of tumor progression and its signaling pathway contributes to seeking a novel anti-cancer therapy.

Molecular mechanisms involved in HIV-1 Tat-mediated induction of IL-6 and IL-8 in astrocytes

Background

HIV-associated neurocognitive disorders (HAND) exist in approximately 50% of infected individuals even after the introduction of highly active antiretroviral therapy. HIV-1 Tat has been implicated in HIV-associated neurotoxicity mediated through production of pro-inflammatory cytokines like IL-6 and IL-8 by astrocytes among others as well as oxidative stress. However, the underlying mechanism(s) in the up-regulation of IL-6 and IL-8 are not clearly understood. The present study was designed to determine the mechanism(s) responsible for IL-6 and IL-8 up-regulation by HIV-1 Tat.

Methods

SVG astrocytes were transiently transfected with a plasmid encoding HIV-1 Tat. The HIV-1 Tat-mediated mRNA and protein expression levels of both IL-6 and IL-8 in SVG astrocytes were quantified using real time RT-PCR and multiplex cytokine assay respectively. We also employed immunocytochemistry for staining of IL-6 and IL-8. The underlying signaling mechanism(s) were identified using pharmacological inhibitors and siRNA for different intermediate steps involved in PI3K/Akt, p38 MAPK and JNK MAPK pathways. Appropriate controls were used in the experiments and the effect of pharmacological antagonists and siRNA were observed on both mRNA expression and protein levels.

Results

Both IL-6/IL-8 mRNA and protein showed peak expressions at 6 hours and 96 hours post-transfection, respectively. Elevated levels of IL-6/IL-8 were also confirmed by immunocytochemistry. Our studies indicated that both NF-kB and AP-1 transcription factors were involved in IL-6 and IL-8 expression mediated by HIV-1 Tat; however, AP-1 was differentially activated for either cytokine. In the case of IL-6, p38δ activated AP-1 whereas JNK but not p38 MAPK was involved in AP-1 activation for IL-8 production. On the other hand both PI3K/Akt and p38 MAPK (β subunit) were found to be involved in activation of NF-κB that led to IL-6 and IL-8 production.

Conclusion

Our results demonstrate HIV-1 Tat-mediated induction of both IL-6 and IL-8 in a time-dependent manner in SVG astrocytes. Furthermore, we also showed the involvement of NF-κB and AP-1 transcription factors regulated by PI3/Akt, p38 MAPK and JNK MAPK upstream signaling molecules. These results present new therapeutic targets that could be used in management of HAND.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-014-0214-3) contains supplementary material, which is available to authorized users.

Osteopontin is expressed in the mouse uterus during early pregnancy and promotes mouse blastocyst attachment and invasion in vitro

Embryo implantation into the maternal uterus is a decisive step for successful mammalian pregnancy. Osteopontin (OPN) is a member of the small integrin-binding ligand N-linked glycoprotein family and participates in cell adhesion and invasion. In this study, we showed that Opn mRNA levels are up-regulated in the mouse uterus on day 4 and at the implantation sites on days 5 and 8 of pregnancy. Immunohistochemistry localized the OPN protein to the glandular epithelium on day 4 and to the decidual zone on day 8 of pregnancy. OPN mRNA and proteins are induced by in vivo and in vitro decidualization. OPN expression in the endometrial stromal cells is regulated by progesterone, a key regulator during decidualization. As a secreted protein, the protein level of OPN in the uterine cavity is enriched on day 4, and in vitro embryo culturing has indicated that OPN can facilitate blastocyst hatching and adhesion. Knockdown of OPN attenuates the adhesion and invasion of blastocysts in mouse endometrial stromal cells by suppressing the expression and enzymatic activity of matrix metalloproteinase-9 in the trophoblast. Our data indicated that OPN expression in the mouse uterus during early pregnancy is essential for blastocyst hatching and adhesion and that the knockdown of OPN in mouse endometrial stroma cells could lead to a restrained in vitro trophoblast invasion.

Role of osteopontin in the pathophysiology of cancer

Osteopontin (OPN) is a multifunctional cytokine that impacts cell proliferation, survival, drug resistance, invasion, and stem like behavior. Due to its critical involvement in regulating cellular functions, its aberrant expression and/or splicing is functionally responsible for undesirable alterations in disease pathologies, specifically cancer. It is implicated in promoting invasive and metastatic progression of many carcinomas. Due to its autocrine and paracrine activities OPN has been shown to be a crucial mediator of cellular cross talk and an influential factor in the tumor microenvironment. OPN has been implicated as a prognostic and diagnostic marker for several cancer types. It has also been explored as a possible target for treatment. In this article we hope to provide a broad perspective on the importance of OPN in the pathophysiology of cancer.

TBLR1 is a novel prognostic marker and promotes epithelial-mesenchymal transition in cervical cancer

BACKGROUND

Invasion and metastasis remain a critical issue in cervical cancer. However, the underlying mechanism of it in cervical cancer remains unclear. The newly discovered protein, TBLR1, plays a crucial role in regulating various key cellular functions.

METHODS

In this study, western blot, real-time RT-PCR, immunohistochemical staining, 3D morphogenesis Matrigel culture, wound healing and Boyden chamber invasion assays, xenografted tumour model, luciferase assays, and chromatin immunoprecipitation assays were used.

RESULTS

The expression of TBLR1 in cervical cancer cell lines and tissues was significantly upregulated at both the RNA and protein levels compared with that in normal cervical cells. Statistical analysis suggested that TBLR1 as an independent prognostic factor was significantly correlated with the clinical stage, survival time and recurrence. Moreover, overexpression of TBLR1 in Hela and Siha cell lines promoted invasion in vitro and in vivo with the increases of the mesenchymal factors vimentin and fibronectin and decreases of the epithelial marker α-catenin. In contrast, RNAi-mediated knockdown of TBLR1 inhibited epithelial-mesenchymal transition in vitro and in vivo. Further study indicated that this might be mediated via the NF-κB and Wnt/β-Catenin signalling pathway, and involve regulation of Snail and Twist.

CONCLUSIONS

The TBLR1 protein may be a prognostic marker in cervical cancer and play an important role in the invasion and metastasis of human cervical cancer.

Semaphorin 3A upregulates FOXO 3a-dependent MelCAM expression leading to attenuation of breast tumor growth and angiogenesis

Semaphorin 3A (Sema 3A), a member of semaphorin family, serves as a guidance clue during embryonic development and is known as a candidate tumor suppressor that attenuates breast tumor progression by binding with its co-receptor, neuropilin-1 (NRP-1). However, the underlying mechanism by which Sema 3A suppresses breast tumor growth is still unexplored. In this study, we report that Sema 3A regulates phosphorylation and nuclear translocation of phosphatase and tensin homolog (PTEN) and FOXO 3a. Moreover, Sema 3A controls NRP-1-mediated PTEN-dependent FOXO 3a activation. Overexpression of PTEN and FOXO 3a enhances Sema 3A-induced attenuation of breast cancer cell migration. Chromatin immunoprecipitation and electrophoretic mobility shift assay data revealed that FOXO 3a regulates MelCAM at the transcriptional level. Furthermore, Sema 3A induces NRP-1-mediated MelCAM expression through PTEN and FOXO 3a. The data also showed that vascular endothelial growth factor-induced angiogenesis is inhibited by Sema 3A. Loss of or gain in function study revealed that Sema 3A modulates phosphorylation of PTEN and FOXO 3a and expression of MelCAM, leading to suppression of tumor growth and angiogenesis using in vivo mice model. Clinical specimen analysis revealed that reduced expression of Sema 3A and p-PTEN are correlated with enhanced breast cancer progression, further strengthening our in vitro and in vivo findings. Correlation of relapse-free survival of breast cancer patients (n=2878) with expression levels of Sema 3A, NRP-1, FOXO 3a and MelCAM were studied by Kaplan-Meier analysis. Statistical analysis revealed a close association between reduced expression of Sema 3A and MelCAM with that of poor patient's survival. Our study demonstrated a novel mechanism of regulation of tumor suppression by Sema 3A in coordination with a chain of tumor-suppressor genes, which in turn inhibits breast cancer cell migration, tumor growth and angiogenesis.