Mesenchymal-epithelial signalling in tumour microenvironment: role of high-mobility group Box 1

Prognostic value of RNA methylation-related genes in gastric adenocarcinoma based on bioinformatics

Background

Gastric cancer (GC) is a malignant tumor that originates from the epithelium of the gastric mucosa and has a poor prognosis. Stomach adenocarcinoma (STAD) covers 95% of total gastric cancer. This study aimed to identify the prognostic value of RNA methylation-related genes in gastric cancer.

Methods

In this study, The Cancer Genome Atlas (TCGA)-STAD and GSE84426 cohorts were downloaded from public databases. Patients were classified by consistent cluster analysis based on prognosis-related differentially expressed RNA methylation genes Prognostic genes were obtained by differential expression, univariate Cox and least absolute shrinkage and selection operator (LASSO) analyses. The prognostic model was established and validated in the training set, test set and validation set respectively. Independent prognostic analysis was implemented. Finally, the expression of prognostic genes was affirmed by reverse transcription quantitative PCR (RT-qPCR).

Results

In total, four prognostic genes (ACTA2, SAPCD2, PDK4 and APOD) related to RNA methylation were identified and enrolled into the risk signature. The STAD patients were divided into high- and low-risk groups based on the medium value of the risk score, and patients in the high-risk group had a poor prognosis. In addition, the RNA methylation-relevant risk signature was validated in the test and validation sets, and was authenticated as a reliable independent prognostic predictor. The nomogram was constructed based on the independent predictors to predict the 1/3/5-year survival probability of STAD patients. The gene set enrichment analysis (GSEA) result suggested that the poor prognosis in the high-risk subgroup may be related to immune-related pathways. Finally, the experimental results indicated that the expression trends of RNA methylation-relevant prognostic genes in gastric cancer cells were in agreement with the result of bioinformatics.

Conclusion

Our study established a novel RNA methylation-related risk signature for STAD, which was of considerable significance for improving prognosis of STAD patients and offering theoretical support for clinical therapy.

The crosstalk among the physical tumor microenvironment and the effects of glucose deprivation on tumors in the past decade

The occurrence and progression of tumors are inseparable from glucose metabolism. With the development of tumors, the volume increases gradually and the nutritional supply of tumors cannot be fully guaranteed. The tumor microenvironment changes and glucose deficiency becomes the common stress environment of tumors. Here, we discuss the mutual influences between glucose deprivation and other features of the tumor microenvironment, such as hypoxia, immune escape, low pH, and oxidative stress. In the face of a series of stress responses brought by glucose deficiency, different types of tumors have different coping mechanisms. We summarize the tumor studies on glucose deficiency in the last decade and review the genes and pathways that determine the fate of tumors under harsh conditions. It turns out that most of these genes help tumor cells survive in glucose-deprivation conditions. The development of related inhibitors may bring new opportunities for the treatment of tumors.

RAGE Inhibitors for Targeted Therapy of Cancer: A Comprehensive Review

The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin family that is overexpressed in several cancers. RAGE is highly expressed in the lung, and its expression increases proportionally at the site of inflammation. This receptor can bind a variety of ligands, including advanced glycation end products, high mobility group box 1, S100 proteins, adhesion molecules, complement components, advanced lipoxidation end products, lipopolysaccharides, and other molecules that mediate cellular responses related to acute and chronic inflammation. RAGE serves as an important node for the initiation and stimulation of cell stress and growth signaling mechanisms that promote carcinogenesis, tumor propagation, and metastatic potential. In this review, we discuss different aspects of RAGE and its prominent ligands implicated in cancer pathogenesis and describe current findings that provide insights into the significant role played by RAGE in cancer. Cancer development can be hindered by inhibiting the interaction of RAGE with its ligands, and this could provide an effective strategy for cancer treatment.

Comparison of Diagnostic Reliability of p63 and Smooth Muscle Actin in Salivary Gland Neoplasms

Salivary gland neoplasms pose considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types and variants & similar histological features with other tumor entities. Myoepithelial and basal cells play a significant role in the pathogenesis of salivary gland neoplasm. p63 and smooth muscle actin are more reliable markers for identifying these cells and not studied much comparing their reliability in the diagnosis of salivary gland neoplasms. Hence, the aim of this study is to evaluate and compare the diagnostic reliability of immunohistochemical markers such as p63 and smooth muscle actin (SMA) in the diagnosis of various benign and malignant salivary gland neoplasms. The study comprises of 18 samples categorized into two groups: Group I comprised 9 cases, of which 4 cases were Pleomorphic adenoma, 2 cases were Myoepithelioma, 2 cases of Basal cell adenoma and 1 case was Warthin's tumor; and Group II consisted of 9cases, of which 3 was Mucoepidermoid carcinoma, 1 cases were Myoepithelial carcinoma and 5 cases were Adenoid cystic carcinoma. The selected cases were subjected to immunohistochemistry (IHC) procedure to assess the expression pattern of p63 and smooth muscle actin. The obtained data was analysed statistically by using Mann-Whitney test. In SMA, strong positivity for epithelial and connective tissue components of benign salivary neoplasm is about 22.2%respectively. In malignant salivary neoplasm, SMA was strongly positive for the epithelial and connective tissue component of about 77.7% and 88.8% cases respectively. The difference in the connective tissue components was found to be statistically significant (U = 24, P = 0.032). P63 was strongly positive for the epithelial and connective tissue component of benign salivary neoplasm of about 33.3% and 11.1% cases respectively.In malignant salivary neoplasm, p63 was strongly positive for the epithelial component of about 66.6% cases and connective tissue is completely negative. Alpha-SMA can be utilized as reliable IHC markers for salivary gland neoplasms due to its diagnostic importance in tumors with myoepithelial origin indicative of the histogenesis of salivary gland tumors and even p63 can be used as specific markers for differentiation of malignant salivary gland tumors.

Diabetes and Colorectal Cancer Risk: Clinical and Therapeutic Implications

Several epidemiological studies have identified diabetes as a risk factor for colorectal cancer (CRC). The potential pathophysiological mechanisms of this association include hyperinsulinemia, insulin-like growth factor (IGF) axis, hyperglycemia, inflammation induced by adipose tissue dysfunction, gastrointestinal motility disorder, and impaired immunological surveillance. Several studies have shown that underlying diabetes adversely affects the prognosis of patients with CRC. This review explores the novel anticancer agents targeting IGF-1R and receptor for advanced glycation end products (RAGE), both of which play a vital role in diabetes-induced colorectal tumorigenesis. Inhibitors of IGF-1R and RAGE are expected to become promising therapeutic choices, particularly for CRC patients with diabetes. Furthermore, hypoglycemic therapy is associated with the incidence of CRC. Selection of appropriate hypoglycemic agents, which can reduce the risk of CRC in diabetic patients, is an unmet issue. Therefore, this review mainly summarizes the current studies concerning the connections among diabetes, hypoglycemic therapy, and CRC as well as provides a synthesis of the underlying pathophysiological mechanisms. Our synthesis provides a theoretical basis for rational use of hypoglycemic therapies and early diagnosis and treatment of diabetes-related CRC.

Biological functions and theranostic potential of HMGB family members in human cancers

The high mobility group box (HMGB) protein family consists of four members: HMGB1, 2, 3, and 4. They share similar amino acid sequences and identical functional regions, especially HMGB1, 2, and 3. The homology in structure may lead to similarity in function. In fact, though their targets may be different, they all possess the fundamental function of binding and distorting target DNAs. However, further research confirmed they are distributed differently in tissues and involved in various distinct physiological and pathological cellular processes, including cell proliferation, division, migration, and differentiation. Recently, the roles of HMGB family members in carcinogenesis has been widely investigated; however, systematic discussion on their functions and clinical values in malignant tumors is limited. In this review, we mainly review and summarize recent advances in knowledge of HMGB family members in terms of structure, distribution, biochemical cascades, and specific mechanisms regarding tumor progression. Importantly, the diagnostic, prognostic, and therapeutic value of these proteins in cancers is discussed. Finally, we envisage the orientation and challenges of this field in further studies.

Receptor for Advanced Glycation End Products Acts as a Fuel to Colorectal Cancer Development

Receptor for advanced glycation end-products (RAGE) is a multiligand binding and single-pass transmembrane protein taken in diverse chronic inflammatory conditions. RAGE behaves as a pattern recognition receptor, which binds and is engaged in the cellular response to a variety of damage-associated molecular pattern molecules, as well as HMGB1, S100 proteins, and AGEs (advanced glycation end-products). The RAGE activation turns out to a formation of numerous intracellular signaling mechanisms, resulting in the progression and prolongation of colorectal carcinoma (CRC). The RAGE expression correlates well with the survival of colon cancer cells. RAGE is involved in the tumorigenesis, which increases and develops well in the stressed tumor microenvironment. In this review, we summarized downstream signaling cascade activated by the multiligand activation of RAGE, as well as RAGE ligands and their sources, clinical studies, and tumor markers related to RAGE particularly in the inflammatory tumor microenvironment in CRC. Furthermore, the role of RAGE signaling pathway in CRC patients with diabetic mellitus is investigated. RAGE has been reported to drive assorted signaling pathways, including activator protein 1, nuclear factor-κB, signal transducer and activator of transcription 3, SMAD family member 4 (Smad4), mitogen-activated protein kinases, mammalian target of rapamycin, phosphoinositide 3-kinases, reticular activating system, Wnt/β-catenin pathway, and Glycogen synthase kinase 3β, and even microRNAs.

Role and Mechanisms of RAGE-Ligand Complexes and RAGE-Inhibitors in Cancer Progression

Interactions of the receptor for advanced glycation end product (RAGE) and its ligands in the context of their role in diabetes mellitus, inflammation, and carcinogenesis have been extensively investigated. This review focuses on the role of RAGE-ligands and anti-RAGE drugs capable of controlling cancer progression. Different studies have demonstrated interaction of RAGE with a diverse range of acidic (negatively charged) ligands such as advanced glycation end products (AGEs), high-mobility group box1 (HMGB1), and S100s, and their importance to cancer progression. Some RAGE-ligands displayed effects on anti- and pro-apoptotic proteins through upregulation of the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), mitogen-activated protein kinases (MAPKs), matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and nuclear factor kappa B (NF-κB) pathways, while downregulating p53 in cancer progression. In addition, RAGE may undergo ligand-driven multimodal dimerization or oligomerization mediated through self-association of some of its subunits. We conclude our review by proposing possible future lines of study that could result in control of cancer progression through RAGE inhibition.

HMGB1: an overview of its versatile roles in the pathogenesis of colorectal cancer

BACKGROUND

In recent years, the high mobility group box-1 (HMGB1) protein, a damage-associated molecular pattern (DAMP) molecule, has been found to play multifunctional roles in the pathogenesis of colorectal cancer. Although much attention has been given to the diagnostic and prognostic values of HMGB1 in colorectal cancer, the exact functional roles of the protein as well as the mechanistic pathways involved have remained poorly defined. This systematic review aims to discuss what is currently known about the roles of HMGB1 in colorectal cancer development, growth and progression, and to highlight critical areas for future investigations. To achieve this, the bibliographic databases Pubmed, Scopus, Web of Science and ScienceDirect were systematically screened for articles from inception till June 2018, which address associations of HMGB1 with colorectal cancer.

CONCLUSIONS

HMGB1 plays multiple roles in promoting the pathogenesis of colorectal cancer, despite a few contradicting studies. HMGB1 may differentially regulate disease-related processes, depending on the redox status of the protein in colorectal cancer. Binding of HMGB1 to various protein partners may alter the impact of HMGB1 on disease progression. As HMGB1 is heavily implicated in the pathogenesis of colorectal cancer, it is crucial to further improve our understanding of the functional roles of HMGB1 not only in colorectal cancer, but ultimately in all types of cancers.

Utility of smooth muscle actin and CD117 as reliable markers in the diagnosis of salivary gland neoplasms

Objective:

The aim of this study is to analyze the utility of immunohistochemical markers such as CD117 and smooth muscle actin (SMA) in the diagnosis of various benign and malignant salivary gland neoplasms.

Materials and Methods:

The study comprises 17 samples categorized into three groups: Group I consisted of 5 histopathologically normal salivary gland tissue; Group II comprised 7 cases, of which 3 cases were pleomorphic adenoma, 3 cases were myoepithelioma and 1 case was Warthin's tumor; and Group III consisted of 5 cases, of which 1 was mucoepidermoid carcinoma and 4 cases were adenoid cystic carcinoma. The selected cases were subjected to immunohistochemistry (IHC) procedure to assess the expression pattern of CD117 and SMA.

Results:

In SMA, 85.8% showed severe-to-moderate intense expression among the tumor cells in benign salivary gland tumor. All the 5 malignant tumors showed the expression of SMA and 3 cases demonstrated severe expression among the tumor cells. An intense expression pattern of SMA was observed in both benign and malignant neoplasms in the periphery and stromal components of the tumor. Only two cases were positive for CD117, and connective tissue components were completely negative in both malignant and benign salivary gland neoplasms.

Conclusion:

Alpha-SMA can be utilized as reliable IHC markers for salivary gland neoplasms due to its diagnostic importance in tumors with myoepithelial origin indicative of the histogenesis of salivary gland tumors.

Translationally controlled tumor protein affects colorectal cancer metastasis through the high mobility group box 1-dependent pathway

Recently, accumulating evidence from clinical and experimental researches have suggested that translationally controlled tumor protein (TCTP) and high mobility group box 1 (HMGB1) are implicated in colorectal cancer (CRC) metastasis. However, whether there is an interconnection between these two tumor-promoting proteins and how they affect CRC metastasis remain to be fully elucidated. In the present study, the expression level of TCTP in CRC tissues was assessed by immunohistochemical staining and immunoblotting, and the serum concentration of HMGB1 in patients with CRC was detected by enzyme-linked immunosorbent assay. In vitro, following the modulation of TCTP expression in colon cancer LoVo cells, the translocation behavior of HMGB1 was observed by immunofluorescence assay. Furthermore, the activity of nuclear factor-κB (NF-κB) in LoVo cells was evaluated by immunoblotting and luciferase assay, and the invasion ability of LoVo cells after different treatments was determined using cell invasion assay. In vivo, xenograft tumor model was established and the correlation of TCTP and HMGB1 expression in xenografted tumors was studied by immunohistochemical examination. The results revealed that the expression level of TCTP in CRC tissue and the serum concentration of HMGB1 in patients with CRC were significantly increased, and there was a strong positive correlation between them. In vitro experiments showed that the overexpression of TCTP on LoVo cells resulted in the release of HMGB1 from the nucleus to the cytoplasm and into the extracellular space. In addition, the overexpression of TCTP led to the activation of NF-κB in LoVo cells, and this effect was reversed by treatment with antibodies targeting HMGB1 or to its receptors Toll-like receptor 4 (TLR4) and receptor for advanced glycation end products advanced glycation end products (RAGE). Furthermore, inhibition of the HMGB1-TLR4/RAGE-NF-κB pathway significantly inhibited the TCTP-stimulated invasion of LoVo cells. In vivo experiments demonstrated that the over-expression of TCTP in nude mice promoted the development and spread of xenografted tumors, and concurrently enhanced the expression of HMGB1 in tumor tissues. Collectively, these findings suggested that TCTP promotes CRC metastasis through regulating the behaviors of HMGB1 and the downstream activation of the NF-κB signaling pathway.

HPV-transformed cells exhibit altered HMGB1-TLR4/MyD88-SARM1 signaling axis

Cervical cancer is one of the leading causes of cancer death in women worldwide. Persistent infection with high-risk human papillomavirus (HPV) types is the main risk factor for the development of cervical cancer precursor lesions. HPV persistence and tumor development is usually characterized by innate immune system evasion. Alterations in Toll-like receptors (TLR) expression and activation may be important for the control of HPV infections and could play a role in the progression of lesions and tumors. In the present study, we analyzed the mRNA expression of 84 genes involved in TLR signaling pathways. We observed that 80% of the differentially expressed genes were downregulated in cervical cancer cell lines relative to normal keratinocytes. Major alterations were detected in genes coding for several proteins of the TLR signaling axis, including TLR adaptor molecules and genes associated with MAPK pathway, NFκB activation and antiviral immune response. In particular, we observed major alterations in the HMGB1-TLR4 signaling axis. Functional analysis also showed that HMGB1 expression is important for the proliferative and tumorigenic potential of cervical cancer cell lines. Taken together, these data indicate that alterations in TLR signaling pathways may play a role in the oncogenic potential of cells expressing HPV oncogenes.

Disorders noticed during development of pancreatic cancer: potential opportunities for early and effective diagnostics and therapy

Pancreatic cancer, with a total five-year survival rate below 5%, represents a disease with a high level of malignancy. Some of the pancreatic cancer bad prognosis factors are nutrition disorders. Malnutrition, neither recognized nor properly referred to by the healthcare system, leads to well-documented negative health consequences in hospitalized patients including their impaired immunity, delayed post-surgery wound healing, a high risk of infectious complications, morbidity and mortality. There are numerous factors contributing to the development of pancreatic cancer, including telomerases, inflammation, angiogenesis, epigenetics and genetics factors, miRNA, pancreatic cancer stem cells. On the basis of molecular analyses, it has been established that precursor injuries may trigger pancreatic cancer when added to genetic alterations. Perhaps, combination of few presently used methods, like signal transduction modulated by K-ras, STAT3 activation, HMGB1 releasing, presence of oxidative stress and free radicals secretion, genes for proangiogenic growth factors activation or tissue-specific miRNA genes expression - will solve the problem of inadequate diagnostics.

Detection of RACK1 and CTNNBL1‑induced activation of mouse splenocytes using an immunoprecipitation‑based technique

Tumor cell lysates (TCLs) have been reported to induce antitumor immunity; however, it remains unclear which elements serve a role in this process. The present study identified 768 proteins that were upregulated in TCL prepared from Lewis lung cancer cells compared with the lysate from type II alveolar epithelial cells. Among the proteins that were upregulated in TCL, receptor for activated C kinase 1 (RACK1) and catenin β‑like 1 (CTNNBL1) are closely associated with cell proliferation and the inhibition of apoptosis. To determine the role of these proteins in TCL, a protein extraction method was designed, which was based on immunoprecipitation. Using this method, RACK1 and CTNNBL1 were extracted, whereas the other proteins within the TCL were not affected. The modified TCL exhibited a stronger ability to induce splenocyte apoptosis, whereas the ability to promote cell activation was reduced. These findings suggested that the TCL depends on RACK1 and CTNNBL1 to activate mouse immunocytes, including monocytes and B lymphocytes, and inhibit apoptosis. Therefore, the present study may provide information regarding the composition of TCLs and their positive regulatory effect on immunocytes.

Paeonol Inhibits Lipopolysaccharide-Induced HMGB1 Translocation from the Nucleus to the Cytoplasm in RAW264.7 Cells

Transport of high-mobility group box 1 (HMGB1), a highly conserved non-histone DNA-binding protein, from the nucleus to the cytoplasm is induced by lipopolysaccharide (LPS). Secretion of HMGB1 appears to be a key lethal factor in sepsis, so it is considered to be a therapeutic target. Previous studies have suggested that paeonol (2'-hydroxy-4'-methoxyacetophenone), an active compound of Paeonia lactiflora Pallas, exerts anti-inflammatory effects. However, the effect of paeonol on HMGB1 is unknown. Here, we investigated the effect of paeonol on the expression, location, and secretion of HMGB1 in LPS-induced murine RAW264.7 cells. ELISA revealed HMGB1 supernatant concentrations of 615 ± 30 ng/mL in the LPS group and 600 ± 45, 560 ± 42, and 452 ± 38 ng/mL in cells treated with 0.2, 0.6, or 1 mM paeonol, respectively, suggesting that paeonol inhibits HMGB1 secretion induced by LPS. Immunohistochemistry and Western blotting revealed that paeonol decreased cytoplasmic HMGB1 and increased nuclear HMGB1. Chromatin immunoprecipitation microarrays suggested that HMGB1 relocation to the nucleus induced by paeonol might depress the action of Janus kinase/signal transducers and activators of transcription, chemokine, and mitogen-activated protein kinase pro-inflammatory signaling pathways. Paeonol was also found to inhibit tumor necrosis factor-α promoter activity in a dose-dependent manner. These results indicate that paeonol has the potential to be developed as a novel HMGB1-targeting therapeutic drug for the treatment of inflammatory diseases.

The plasticity of germ cell cancers and its dependence on the cellular microenvironment

So far, the understanding of germ cell cancer (GCC) pathogenesis is based on a model, where seminomas and non‐seminomas represent distinct entities although originating from a common precursor termed germ cell neoplasia in situ (GCNIS). Embryonal carcinomas (ECs), the stem cell population of the non‐seminomas, is pluri‐ to totipotent and able to differentiate into cells of all three germ layers, giving rise to teratomas or tumours mimicking extraembryonic tissues (yolk sac tumours, choriocarcinomas). With regard to gene expression, (epi)genetics and histology, seminomas are highly similar to GCNIS and primordial germ cells, but limited in development. It remains elusive, whether this block in differentiation is controlled by cell intrinsic mechanisms or by signals from the surrounding microenvironment. Here, we reviewed the recent literature emphasizing the plasticity of GCCs, especially of seminomas. We propose that this plasticity is controlled by the microenvironment, allowing seminomas to transit into an EC or mixed non‐seminoma and vice versa. We discuss several mechanisms and routes of reprogramming that might be responsible for this change in the cell fate. We finally integrate this plasticity into a new model of GCC pathogenesis, allowing for an alternative view on the dynamics of GCC development and progression.