High-level expression of periostin is closely related to metastatic potential and poor prognosis of hepatocellular carcinoma

Correlation between Periostin Expression and Pro-Angiogenic Factors in Non-Small-Cell Lung Carcinoma

The role of periostin (POSTN) in remodeling the microenvironment surrounding solid tumors and its effect on the tumor cells in non-small-cell lung carcinoma (NSCLC) have not yet been fully understood. The aim of this study was to determine the relationship between POSTN expression (in tumor cells [NSCLC cells] and the tumor stroma) and pro-angiogenic factors (CD31, CD34, CD105, and VEGF-A) and microvascular density (MVD) in NSCLC. In addition, these associations were analyzed in individual histological subtypes of NSCLC (SCC, AC, and LCC) and their correlations with clinicopathological factors and prognosis were examined. Immunohistochemistry using tissue microarrays (TMAs) was used to assess the expression of POSTN (in tumor cells and cancer-associated fibroblasts [CAFs]) and the pro-angiogenic factors. A significant positive correlation was found between the expression of POSTN (in cancer cells/CAFs) and the expression of the analyzed pro-angiogenic factors (CD31, CD34, CD105, and VEGF-A) and MVD in the entire population of patients with NSCLC and individual histological subtypes (AC, SCC). In addition, this study found that POSTN expression (in tumor cells/CAFs) increased with tumor size (pT), histopathological grade (G), and lymph-node involvement (pN). In addition, a high expression of POSTN (in tumor cells and CAFs) was associated with shorter survival among patients with NSCLC. In conclusion, a high expression of POSTN (in cancer cells and CAFs) may be crucial for angiogenesis and NSCLC progression and can constitute an independent prognostic factor for NSCLC.

Crosstalk between endothelial progenitor cells and HCC through periostin/CCL2/CD36 supports formation of the pro-metastatic microenvironment in HCC

Metastasis causes most cancer-related deaths, and the role and mechanism of periostin (POSTN) in the metastasis of hepatocellular carcinoma (HCC) remain undiscovered. In this study, DEN and HTVi HCC models were performed in hepatic-specific Postn ablation and Postn knock-in mouse to reveal the role of POSTN in HCC metastasis. Furthermore, POSTN was positively correlated with circulating EPCs level and promoted EPC mobilization and tumour infiltration. POSTN also mediated the crosstalk between HCC and EPCs, which promoted metastasis ability and upregulated CD36 expression in HCC through indirect crosstalk. Chemokine arrays further revealed that hepatic-derived POSTN induced elevated CCL2 expression and secretion in EPCs, and CCL2 promoted prometastatic traits in HCC. Mechanistic studies showed that POSTN upregulated CCL2 expression in EPCs via the αvβ3/ILK/NF-κB pathway. CCL2 further induced CD36 expression via the CCR2/STAT3 pathway by directly binding to the promoter region of CD36. Finally, CD36 was verified to have a prometastatic role in vitro and to be correlated with POSTN expression, metastasis and recurrence in HCC in clinical samples. Our findings revealed that crosstalk between HCC and EPCs is mediated by periostin/CCL2/CD36 signalling which promotes HCC metastasis and emphasizes a potential therapeutic strategy for preventing HCC metastasis.

Multiple Roles of LOXL2 in the Progression of Hepatocellular Carcinoma and Its Potential for Therapeutic Targeting

LOXL2, a copper-dependent amine oxidase, has emerged as a promising therapeutic target in hepatocellular carcinoma (HCC). Increased LOXL2 expression in HCC has been linked with an aggressive phenotype and represents a poor prognostic factor. Here, we focus on the mechanisms through which LOXL2 orchestrates multiple oncogenic functions in HCC development. We performed a review of the current knowledge on the roles LOXL2 performs in the modulation of the HCC tumor microenvironment, formation of premetastatic niches, and epithelial-mesenchymal transition. We also highlighted the complex interplay between LOXL2 and hypoxia, angiogenesis, and vasculogenic mimicry in HCC. At the end of the review, we summarize the current LOXL2 inhibitors and discuss their potential in HCC precision treatment.

Association of Differentially Altered Liver Fibrosis with Deposition of TGFBi in Stabilin-Deficient Mice

Liver sinusoidal endothelial cells (LSECs) control clearance of Transforming growth factor, beta-induced, 68kDa (TGFBi) and Periostin (POSTN) through scavenger receptors Stabilin-1 (Stab1) and Stabilin-2 (Stab2). Stabilin inhibition can ameliorate atherosclerosis in mouse models, while Stabilin-double-knockout leads to glomerulofibrosis. Fibrotic organ damage may pose a limiting factor in future anti-Stabilin therapies. While Stab1-deficient (Stab1-/-) mice were shown to exhibit higher liver fibrosis levels upon challenges, fibrosis susceptibility has not been studied in Stab2-deficient (Stab2-/-) mice. Wildtype (WT), Stab1-/- and Stab2-/- mice were fed experimental diets, and local ligand abundance, hepatic fibrosis, and ligand plasma levels were measured. Hepatic fibrosis was increased in both Stab1-/- and Stab2-/- at baseline. A pro-fibrotic short Methionine-Choline-deficient (MCD) diet induced slightly increased liver fibrosis in Stab1-/- and Stab2-/- mice. A Choline-deficient L-amino acid-defined (CDAA) diet induced liver fibrosis of similar distribution and extent in all genotypes (WT, Stab1-/- and Stab2-/-). A hepatic abundance of Stabilin ligand TGFBi correlated very highly with liver fibrosis levels. In contrast, plasma levels of TGFBi were increased only in Stab2-/- mice after the CDAA diet but not the MCD diet, indicating the differential effects of these diets. Here we show that a single Stabilin deficiency of either Stab1 or Stab2 induces mildly increased collagen depositions under homeostatic conditions. Upon experimental dietary challenge, the local abundance of Stabilin ligand TGFBi was differentially altered in Stabilin-deficient mice, indicating differentially affected LSEC scavenger functions. Since anti-Stabilin-directed therapies are in clinical evaluation for the treatment of diseases, these findings bear relevance to treatment with novel anti-Stabilin agents.

The Role of Periostin in Angiogenesis and Lymphangiogenesis in Tumors

Simple Summary

Cancers are common diseases that affect people of all ages worldwide. For this reason, continuous attempts are being made to improve current therapeutic options. The formation of metastases significantly decreases patient survival. Therefore, understanding the mechanisms that are involved in this process seems to be crucial for effective cancer therapy. Cancer dissemination occurs mainly through blood and lymphatic vessels. As a result, many scientists have conducted a number of studies on the formation of new vessels. Many studies have shown that proangiogenic factors and the extracellular matrix protein, i.e., periostin, may be important in tumor angio- and lymphangiogenesis, thus contributing to metastasis formation and worsening of the prognosis.

Abstract

Periostin (POSTN) is a protein that is part of the extracellular matrix (ECM) and which significantly affects the control of intracellular signaling pathways (PI3K-AKT, FAK) through binding integrin receptors (αvβ3, αvβ5, α6β4). In addition, increased POSTN expression enhances the expression of VEGF family growth factors and promotes Erk phosphorylation. As a result, this glycoprotein controls the Erk/VEGF pathway. Therefore, it plays a crucial role in the formation of new blood and lymphatic vessels, which may be significant in the process of metastasis. Moreover, POSTN is involved in the proliferation, progression, migration and epithelial-mesenchymal transition (EMT) of tumor cells. Its increased expression has been detected in many cancers, including breast cancer, ovarian cancer, non-small cell lung carcinoma and glioblastoma. Many studies have shown that this protein may be an independent prognostic and predictive factor in many cancers, which may influence the choice of optimal therapy.

Recent Perspectives on the Mechanism of Recurrence After Ablation of Hepatocellular Carcinoma: A Mini-Review

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Hepatectomy, liver transplantation, and ablation are the three radical treatments for early-stage hepatocellular carcinoma (ESHCC), but not all patients are fit for or can tolerate surgery; moreover, liver donors are limited. Therefore, ablation plays an important role in the treatment of ESHCC. However, some studies have shown that ablation has a higher local recurrence (LR) rate than hepatectomy and liver transplantation. The specific mechanism is unknown. The latest perspectives on the mechanism of recurrence after ablation of HCC were described and summarized. In this review, we discussed the possible mechanisms of recurrence after ablation of HCC, including epithelial–mesenchymal transition (EMT), activating autophagy, changes in non-coding RNA, and changes in the tumor microenvironment. A systematic and comprehensive understanding of the mechanism will contribute to the research and development of related treatment, combined with ablation to improve the therapeutic effect in patients with ESHCC.

Anti-POSTN and Anti-TIMP1 Autoantibodies as Diagnostic Markers in Esophageal Squamous Cell Carcinoma

Esophageal cancer is one of the most commonly diagnosed malignant gastrointestinal tumors. The aim of the study was to explore the diagnostic values of anti-POSTN and anti-TIMP1 autoantibodies in esophageal squamous cell carcinoma (ESCC). Differentially expressed genes (DEGs) associated with esophageal cancer were screened out by the LIMMA method in the Gene Expression Profiling Interactive Analysis (GEPIA) platform. Search Tool for the Retrieval of Interacting Genes (STRING) was used to construct the protein-protein interaction (PPI) based on highly DEGs. The candidate hub genes were the intersection genes calculated based on degree and Maximal Clique Centrality (MCC) algorithms via Cytoscape. A total of 370 participants including 185 ESCC patients and 185 matched normal controls were enrolled in enzyme-linked immunosorbent assay (ELISA) to detect the expression levels of autoantibodies corresponding to POSTN and TIMP1 proteins. A total of 375 DEGs with high expression were obtained in esophageal cancer. A total of 20 hub genes were acquired using the cytoHubba plugin by degree and MCC algorithms. The expression levels of anti-POSTN and anti-TIMP1 autoantibodies were higher in the sera of ESCC patients (p < 0.05). Anti-POSTN autoantibody can diagnose ESCC patients with an AUC of 0.638 at the specificity of 90.27% and sensitivity of 27.57%, and anti-TIMP1 autoantibody can diagnose ESCC patients with an AUC of 0.585 at the specificity of 90.27% and sensitivity of 20.54% (p < 0.05). In addition, anti-POSTN and anti-TIMP1 autoantibodies can distinguish ESCC patients from normal controls in most clinical subgroups (p < 0.05). In conclusion, anti-POSTN and anti-TIMP1 autoantibodies may be considered the potential biomarkers in the clinical diagnosis of ESCC.

Skin atrophy caused by topical glucocorticoids is less common in patients with atopic dermatitis than in those with psoriasis

Although the long-term use of topical glucocorticoids (TGC) may induce skin atrophy including striae distensae (SD), patients with atopic dermatitis (AD) appear to have lesser degree of skin atrophy than those with psoriasis (PSO). Periostin, encoded by POSTN, is involved in tissue remodelling processes of chronic AD lesions. This study was designed to investigate the difference in the occurrence of skin atrophy in patients with AD or PSO when treated with TGC and to elucidate the association between skin atrophy and periostin. Big data analysis using Korean Health Claims Database was performed to determine the prevalence of SD in AD and PSO patients. Blood and skin eosinophils count and dermal fibrosis between AD and PSO patients were compared, and immunohistochemistry for periostin and mRNA sequencing in the dermis were performed. Animal experiments using AD and PSO murine model were conducted. Big data analysis revealed that patients with AD have significantly lesser degree of SD than patients with PSO. The ratio of the dermal fibrous tissues and eosinophil counts were significantly higher in AD patients. In AD skin, periostin was more widely distributed in the entire dermis and POSTN mRNAs were significantly upregulated. Dermal thickness and fibrosis were significantly higher in AD mice even after TGC treatment. A significant positive correlation was observed between dermal fibrosis and tissue eosinophil counts. Lesser skin atrophy in AD patients even after long-term TGC application could be resulted from skin fibrosis caused by increased tissue eosinophils and periostin deposition.

Periostin deficiency reduces diethylnitrosamine-induced liver cancer in mice by decreasing hepatic stellate cell activation and cancer cell proliferation

Periostin is a critical extracellular regulator in the pathogenesis of liver disorders such as hepatosteatosis, non-alcoholic steatohepatitis, inflammation, and fibrosis. Periostin is also involved in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanisms of periostin in hepatic stellate cell (HSC) activation and tumor cell proliferation in the pathogenesis of HCC remain largely unknown. We demonstrate that periostin is markedly upregulated in diethylnitrosamine (DEN)-induced mouse HCC tissues and that periostin knockout impairs DEN-induced HCC development. Periostin is predominantly derived from activated HSCs and periostin deficiency in HSCs impairs HSC activation and inhibits HSC-promoted HCC cell proliferation in vitro and tumor growth in vivo. Mechanistically, periostin promotes HSC activation through the integrin-FAK-STAT3-periostin pathway and augments HCC cell proliferation by activating ERK. There are positive correlations between periostin and HSC activation and cell proliferation in HCC clinical samples. Collectively, our findings demonstrate that HSC-derived periostin promotes HCC development by enhancing HSC activation through an autocrine periostin-integrin-FAK-STAT3-periostin circuit and by augmenting HCC cell proliferation via the ERK pathway in a paracrine manner. Thus, periostin is a multifaceted extracellular regulator in the development of HCC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Periostin Circulating Levels and Genetic Variants in Patients with Non-Alcoholic Fatty Liver Disease

Circulating periostin has been suggested as a possible biomarker in non-alcoholic fatty liver disease (NAFLD) in Asian studies. In the present study, we aimed to test its still controversial relevance in a Caucasian population. In patients with histologically-proven NAFLD (N. = 74; 10 with hepatocellular carcinoma, HCC) plasma periostin concentrations were analyzed. POSTN haplotype analysis was based on rs9603226, rs3829365, and rs1029728. Hepatitis C patients (N. = 81, 7 HCC) and healthy subjects (N. = 27) were used as controls. The median plasma periostin concentration was 11.6 ng/mL without differences amongst groups; it was not influenced by age, liver fibrosis or steatosis. However, possession of haplotype two (rs9603226 = G, rs3829365 = C, rs1028728 = A) was associated with lower circulating periostin compared to other haplotypes. Moreover, periostin was higher in HCC patients. At multivariate analysis, HCC remained the only predictor of high periostin. In conclusion, plasma periostin concentrations in Caucasians NAFLD patients are not influenced by the degree of liver disease, but are significantly higher in HCC. Genetically-determined differences may account for some of the variability. These data suggest extreme caution in predicting a possible future role of periostin antagonists as a rational therapeutic alternative for NAFLD, but show a potential periostin role in the management of NAFLD-associated HCC.

Blockade of periostin-dependent migration and adhesion by curcumol via inhibition of nuclear factor kappa B signaling in hepatic stellate cells

OBJECTIVES

Curcumol, a guaiane-type sesquiterpenoid hemiketal extracted from the herb Rhizoma Curcumae, exhibits multiple-pharmacological activities. We previously reported that curcumol ameliorated hepatic fibrosis by inhibiting hepatic stellate cell (HSC) activation. In this study, we aimed to investigate the effect of curcumol on HSC migration and adhesion, and reveal its regulation mechanisms.

MATERIALS AND METHODS

Cellular viability was determined by Cell Counting Kit-8. Cell migration was detected by boyden chamber and cell scratch experiment. Recombinant human periostin (rh POSTN) and adeno-associated viral (AAV)-GFP-periostin were used to achieve POSTN overexpression in vitro and in vivo, respectively. Nuclear factor kappa B (NF-κB)-p65 overexpression was achieved by using plasmid. ELISA was conducted to detect POSTN level. Immunohistochemistry, qRT-PCR, Western blotting, and immunofluorescence were performed to assess associated factor expression.

RESULTS

Curcumol suppressed HSC migration and adhesion, and reduced the secretion and expression of POSTN. By gain of function POSTN in HSCs, using rh POSTN, we found that the inhibition of HSC migration and adhesion by curcumol depended on the decrease of POSTN. Besides, curcumol protection against chronic CCl₄-caused hepatic fibrosis could be impaired by POSTN overexpression. Moreover, we showed that curcumol repressed NF-κB signaling and the production of pro-inflammatory factor. Importantly, curcumol down-regulation of POSTN was rescued by knock-in of NF-κB, as well as the inhibition of HSC migration and adhesion.

CONCLUSION

These findings reveal the molecular mechanism of curcumol-reduced HSC migration and adhesion, by which points to the possibility of using curcumol based on NF-κB dependent POSTN for the treatment of fibrogenesis.

Prognostic value of periostin in multiple solid cancers: A systematic review with meta-analysis

Previous studies have shown that the expression of periostin (POSTN) is significantly correlated with prognosis in multiple solid cancers. However, the function of POSTN in tumorigenesis and its relationship with clinical outcomes have not been systematically summarized and analyzed. Thus, a meta-analysis was performed to evaluate the prognostic pertinence of POSTN in solid cancer. We conducted a systematic search in the PubMed, EMBASE, Web of Science, and Cochrane library databases, and a total of 10 studies were used to assess the association of POSTN expression and patients' overall survival (OS) and disease-free survival (DFS). The hazard ratio (HR) or odds ratio (OR) and their corresponding 95% confidence intervals (95% CIs) were further calculated to estimate the association between POSTN and relevant clinical parameters of solid cancer patients. The pooled results indicated that POSTN overexpression was associated with poor OS (HR = 2.35, 95% CI = 1.88-2.93, p < .00001) and DFS (HR = 2.70, 95% CI = 2.00-3.65, p < .00001) in a cohort of 993 patients with cancer. Subsequent analyses showed that the positive expression ratio of POSTN was evidently higher in cancer tissues than in normal tissues (OR = 7.44, 95% CI = 3.66-13.95, p < .00001). In addition, subgroup analysis showed that POSTN was related to microvascular invasion (OR = 5.09, 95% CI = 3.07-8.44, p < .00001), tumor differentiation (OR = 2.03, 95% CI = 1.41-2.91, p = .0001), and lymph node metastasis (OR = 3.05, 95% CI = 2.01-4.64, p < .00001). These data showed that POSTN could be a credible prognostic biomarker and a potential therapeutic target in human solid cancer.

Periostin in chronic liver diseases: Current research and future perspectives

The liver is importantly metabolic and detoxifying organ in the body. When various pathogenic factors affect the liver, the normal physiological and biochemical functions are weakened, resulting in liver diseases. Liver fibrosis is a common pathological process of chronic liver disease. During hepatic fibrosis the changes in the components of the extracellular matrix (ECM) provide an environment that facilitates tissue remodeling. Among these ECM components, periostin, a glycoprotein that is predominantly secreted by osteoblasts and their precursors, playing an important role in bone formation, has attracted great attention. Periostin not only involves in bone metabolism, but also functions in modulating the cell fate determination, proliferation, inflammatory responses, even tumorigenesis of many other tissues and organs including liver. In different categories of liver disease patients, the serum and liver tissue levels of periostin were closely related to the decline of liver function, and the pathological stage. Numerous animal studies and experiments in vitro subsequently demonstrated that the abnormal expression of periostin resulted in metabolic disorders, liver inflammation, fibrosis and even tumorigenesis. Here we review the current progress on the role of periostin in pathologic pathways of liver system to explore whether periostin is a potential therapeutic target for the treatment of different liver diseases.

Periostin involved in the activated hepatic stellate cells-induced progression of residual hepatocellular carcinoma after sublethal heat treatment: its role and potential for therapeutic inhibition

BACKGROUND

Incomplete thermal ablation may induce invasiveness of hepatocellular carcinoma (HCC). Here, we investigated whether activated hepatic stellate cells (HSCs) would accelerate the progression of residual HCC after sublethal heat treatment, and thus sought to identify the potential targets.

METHODS

Hepatocellular carcinoma cells were exposed to sublethal heat treatment and then cultured with the conditioned medium from activated HSCs (HSC-CM). The cell proliferation, migration, invasion and parameters of epithelial-mesenchymal transition (EMT) were analyzed. In vivo tumor progression of heat-treated residual HCC cells inoculated with activated HSCs was studied in nude mice.

RESULTS

HSC-CM significantly enhanced the proliferation, motility, invasion, prominent EMT activation and decreased apoptosis of heat-exposed residual HCC cells. These increased malignant phenotypes were markedly attenuated by neutralizing periostin (POSTN) in HSC-CM. Furthermore, exogenous POSTN administration exerted the similar effects of HSC-CM on heat-treated residual HCC cells. POSTN induced the prominent activation of p52Shc and ERK1/2 via integrin β1 in heat-exposed residual HCC cells. Vitamin D analog calcipotriol blocked POSTN secretion from activated HSCs. Calcipotriol plus cisplatin significantly suppressed the activated HSCs-enhanced tumor progression of heat-treated residual HCC cells via the inhibited POSTN expression and the increased apoptosis.

CONCLUSIONS

Activated HSCs promote the tumor progression of heat-treated residual HCC through the release of POSTN, which could be inhibited by calcipotriol. Calcipotriol plus cisplatin could be used to thwart the accelerated progression of residual HCC after suboptimal heat treatment.

Periostin expression in neoplastic and non-neoplastic diseases of bone and joint

BACKGROUND

Periostin is a matricellular protein that is expressed in bone and joint tissues. To determine the expression of periostin in primary bone tumours and to assess whether it plays a role in tumour progression, we carried out immunohistochemistry and ELISA for periostin in a range of neoplastic and non-neoplastic bone and joint lesions.

METHODS

140 formalin-fixed paraffin-embedded sections of bone tumours and tumour-like lesions were stained by an indirect immunoperoxidase technique with a polyclonal anti-periostin antibody. Periostin expression was also assessed in rheumatoid arthritis (RA) and non-inflammatory osteoarthritis (OA) synovium and synovial fluid immunohistochemistry and ELISA respectively.

RESULTS

Periostin was most strongly expressed in osteoid/woven bone of neoplastic and non-neoplastic bone-forming lesions, including osteoblastoma, osteosarcoma, fibrous dysplasia, osteofibrous dysplasia, fracture callus and myositis ossificans, and mineralised chondroid matrix/woven bone in chondroblastoma and clear cell chondrosarcoma. Reactive host bone at the edge of growing tumours, particularly in areas of increased vascularity and fibrosis, also stained strongly for periostin. Vascular elements in RA synovium strongly expressed periostin, and synovial fluid levels of periostin were higher in RA than OA.

CONCLUSIONS

In keeping with its known role in modulating the synthesis of collagen and other extracellular matrix proteins in bone, strong periostin expression was noted in benign and malignant lesions forming an osteoid or osteoid-like matrix. Periostin was also noted in other bone tumours and was found in areas of reactive bone and increased vascularity at the edge of growing tumours, consistent with its involvement in tissue remodelling and angiogenesis associated with tumour progression.

Periostin promotes liver fibrogenesis by activating lysyl oxidase in hepatic stellate cells

Liver fibrosis arises from dysregulated wound healing due to persistent inflammatory hepatic injury. Periostin is a nonstructural extracellular matrix protein that promotes organ fibrosis in adults. Here, we sought to identify the molecular mechanisms in periostin-mediated hepatic fibrosis. Hepatic fibrosis in periostin^-/- mice was attenuated as evidenced by significantly reduced collagen fibril density and liver stiffness compared with those in WT controls. A single dose of carbon tetrachloride caused similar acute liver injury in periostin^-/- and WT littermates, and we did not detect significant differences in transaminases and major fibrosis-related hepatic gene expression between these two genotypes. Activated hepatic stellate cells (HSCs) are the major periostin-producing liver cell type. We found that in primary rat HSCs in vitro, periostin significantly increases the expression levels and activities of lysyl oxidase (LOX) and lysyl oxidase-like (LOXL) isoforms 1-3. Periostin also induced expression of intra- and extracellular collagen type 1 and fibronectin in HSCs. Interestingly, periostin stimulated phosphorylation of SMAD2/3, which was sustained despite short hairpin RNA-mediated knockdown of transforming growth factor β (TGFβ) receptor I and II, indicating that periostin-mediated SMAD2/3 phosphorylation is independent of TGFβ receptors. Moreover, periostin induced the phosphorylation of focal adhesion kinase (FAK) and AKT in HSCs. Notably, siRNA-mediated FAK knockdown failed to block periostin-induced SMAD2/3 phosphorylation. These results suggest that periostin promotes enhanced matrix stiffness in chronic liver disease by activating LOX and LOXL, independently of TGFβ receptors. Hence, targeting periostin may be of therapeutic benefit in combating hepatic fibrosis.

Periostin: A Matricellular Protein With Multiple Functions in Cancer Development and Progression

Tumor microenvironment is considered nowadays as one of the main players in cancer development and progression. Tumor microenvironment is highly complex and consists of non-tumor cells (i.e., cancer-associated fibroblast, endothelial cells, or infiltrating leukocytes) and a large list of extracellular matrix proteins and soluble factors. The way that microenvironment components interact among them and with the tumor cells is very complex and only partially understood. However, it is now clear that these interactions govern and modulate many of the cancer hallmarks such as cell proliferation, the resistance to death, the differentiation state of tumor cells, their ability to migrate and metastasize, and the immune response against tumor cells. One of the microenvironment components that have emerged in the last years with strength is a heterogeneous group of multifaceted proteins grouped under the name of matricellular proteins. Matricellular proteins are a family of non-structural matrix proteins that regulate a variety of biological processes in normal and pathological situations. Many components of this family such as periostin (POSTN), osteopontin (SPP1), or the CNN family of proteins have been shown to regulate key aspect of tumor biology, including proliferation, invasion, matrix remodeling, and dissemination to pre-metastatic niches in distant organs. Matricellular proteins can be produced by tumor cells themselves or by tumor-associated cells, and their synthesis can be affected by intrinsic and/or extrinsic tumor cell factors. In this review, we will focus on the role of POSTN in the development and progression of cancer. We will describe their functions in normal tissues and the mechanisms involved in their regulation. We will analyze the tumors in which their expression is altered and their usefulness as a biomarker of tumor progression. Finally, we will speculate about future directions for research and therapeutic approaches targeting POSTN.

Proteomic Profiling of Human Uterine Fibroids Reveals Upregulation of the Extracellular Matrix Protein Periostin

The central characteristic of uterine fibroids is excessive deposition of extracellular matrix (ECM), which contributes to fibroid growth and bulk-type symptoms. Despite this, very little is known about patterns of ECM protein expression in fibroids and whether these are influenced by the most common genetic anomalies, which relate to MED12. We performed extensive genetic and proteomic analyses of clinically annotated fibroids and adjacent normal myometrium to identify the composition and expression patterns of ECM proteins in MED12 mutation-positive and mutation-negative uterine fibroids. Genetic sequencing of tissue samples revealed MED12 alterations in 39 of 65 fibroids (60%) from 14 patients. Using isobaric tagged-based quantitative mass spectrometry on three selected patients (n = 9 fibroids), we observed a common set of upregulated (>1.5-fold) and downregulated (<0.66-fold) proteins in small, medium, and large fibroid samples of annotated MED12 status. These two sets of upregulated and downregulated proteins were the same in all patients, regardless of variations in fibroid size and MED12 status. We then focused on one of the significant upregulated ECM proteins and confirmed the differential expression of periostin using western blotting and immunohistochemical analysis. Our study defined the proteome of uterine fibroids and identified that increased ECM protein expression, in particular periostin, is a hallmark of uterine fibroids regardless of MED12 mutation status. This study sets the foundation for further investigations to analyze the mechanisms regulating ECM overexpression and the functional role of upregulated ECM proteins in leiomyogenesis.

Heterogeneous Periostin Expression in Different Histological Variants of Papillary Thyroid Carcinoma

Background

Periostin (PN) epithelial and stromal overexpression in tumor pathology has been studied according to tumor growth, angiogenesis, invasiveness, and metastasis, but a limited number of studies address PN in thyroid tumors.

Aim

Our study aimed to analyze PN expression in different histological variants of PTC and to correlate its expression with the clinicopathological prognostic factors.

Material and Methods

PN expression has been immunohistochemically assessed in 50 cases of PTC (conventional, follicular, oncocytic, macrofollicular, and tall cell variants), in tumor epithelial cells and intratumoral stroma. The association between PN expression and clinicopathological characteristics has been evaluated.

Results

Our results show that PTC presented different patterns of PN immunoreaction, stromal PN being significantly associated with advanced tumor stage and extrathyroidal extension. No correlations were found between PN overexpression in tumor epithelial cells and clinicopathological features, except for specific histological variants, the highest risk of poor outcome being registered for the conventional subtype in comparison to the oncocytic type.

Conclusions

Our study demonstrates differences in PN expression in histological subtypes of PTC. Our results plead in favor of a dominant protumorigenic role of stromal PN, while the action of epithelial PN is less noticeable.

Epithelial periostin expression is correlated with poor survival in patients with invasive breast carcinoma

Invasion and metastasis are direct causes of mortality in patients with breast cancer and require reciprocal interactions between cancer cells and the extracellular matrix (ECM). Periostin, a fasciclin-containing adhesive ECM glycoprotein, is frequently overexpressed in various types of human cancer, and its overexpression in cancer-associated stroma and/or cancer cells is usually associated with poor clinical outcomes. However, the expression of periostin in the successive steps of breast tumorigenesis and its association with outcome variables have not been well established in breast carcinoma. The present study aimed to assess the role of periostin alteration in breast tumorigenesis and evaluate the putative prognostic value of periostin as a function of its compartmentalization. Immunohistochemical staining with anti-periostin antibody was performed in a total of 300 patients (26 patients with normal breast tissues, 76 patients with ductal carcinoma in situ [DCIS], and 198 patients with invasive breast carcinoma [IBC]) using tissue microarray. Periostin immunoreactivity was assessed in both epithelial tissue and the surrounding stromal compartment. The mRNA and protein expression of periostin were analyzed in 10 paired normal/invasive cancer frozen specimens by quantitative real time-polymerase chain reaction and western blot analysis, respectively. In cancer tissues, periostin mRNA and protein expression were increased compared with adjacent normal tissues. Both epithelial and stromal periostin staining scores significantly increased in a stepwise manner with disease progression from normal breast tissue to DCIS and IBC (P = 0.000 and 0.000, respectively). High epithelial and stromal periostin expression was observed in 109/189 (57.7%) and 158/189 (83.6%) cases of IBC, respectively. High epithelial periostin expression was more frequently observed in the distant metastatic relapse-positive group than in the distant metastatic relapse-negative group (41/51 [80.4%] vs. 68/138 [49.3%] cases [P = 0.000]). Furthermore, high epithelial periostin expression was associated with reduced disease-free survival and overall survival in univariate and multivariate analysis. Periostin may play an important role in the progression of breast tumor, and epithelial periostin expression may serve as a new parameter for prediction of prognosis in patients with IBC. Further studies examining periostin expression and its potential as a target of IBC therapy are warranted.

Diagnostic and prognostic value of serum periostin in patients with non-small cell lung cancer

The periostin protein is expressed in a variety of human malignancies. The aim of this study was to explore the diagnostic and prognostic value of serum periostin levels in patients with non-small cell lung cancer (NSCLC). We measured serum periostin levels by ELISA in 296 NSCLC patients, 120 benign lung diseases (BLD) patients and 160 healthy controls. The levels of serum periostin in NSCLC patients were significantly elevated compared with those in healthy controls (P < 0.001) and BLD patients (P < 0.001). Using a cutoff value of 30.87 ng/ml, the sensitivity and specificity of periostin in differentiating between NSCLC patients and BLD patients, and between NSCLC patients and healthy controls was, 48.6 and 91.7%, and 51.4 and 97.5%, respectively. Kaplan-Meier log rank analysis revealed that the higher serum periostin levels group had a poorer progression-free survival (PFS) and overall survival (OS) compared with lower periostin group (P = 0.024, P = 0.015, respectively). Further univariate and multivariate Cox regression analysis showed that serum periostin was an independent risk factor of prognosis of NSCLC patients. In conclusion, our study suggests that serum periostin could be considered as a diagnostic and prognostic marker for NSCLC patients.

The Combination of Periostin Overexpression and Microvascular Invasion Is Related to a Poor Prognosis for Hepatocellular Carcinoma

Background/Aims

Periostin is an extracellular matrix protein and is known to be related to the metastatic potential and prognosis of cancer. However, few studies have investigated the expression level of periostin and its association with prognoses in hepatocellular carcinoma. Therefore, we analyzed periostin overexpression in hepatocellular carcinoma and its implication for prognoses.

Methods

We evaluated 149 patients who underwent surgical resection between 2006 and 2010. Tissue microarrays were constructed from hepatocellular carcinoma tissue and adjacent nontumor tissue, and immunohistochemistry was performed.

Results

A high periostin level was observed more frequently in cases of multiple tumors (odds ratio [OR], 2.826; 95% confidence interval [CI], 1.224 to 6.527; p=0.013), positive microvascular invasion (OR, 2.974; 95% CI, 1.431 to 6.181; p=0.003), and advanced stage disease (OR, 3.032; 95% CI, 1.424 to 6.452; p=0.003). Patients with high periostin expression had significantly (p=0.002) lower overall survival rates than those with low periostin expression (90.3%, 66.1%, and 56.2% vs 97.7%, 85.1%, and 77.5% at 1, 3, and 5 years).

Conclusions

We found that a combination of periostin overexpression and microvascular invasion in hepatocellular carcinoma was correlated with a poor prognosis and can be a good prognostic marker for hepatocellular carcinoma.

Clustering of patients with intrahepatic cholangiocarcinoma based on serum periostin may be predictive of prognosis

An effective serum biomarker may improve cholangiocarcinoma (CCA) management. Periostin (PN) has been demonstrated to be associated with aggressive CCA. The current study evaluated PN in blood serum for its diagnostic and prognostic potential in patients with CCA. Sera of 68 patients with CCA were collected prior to treatment, and PN levels were measured using an ELISA. Sera from 50 normal controls, 6 patients with benign liver diseases, 2 with hepatocellular carcinoma and 21 with breast cancer were analyzed. Immunohistochemistry of PN in CCA tissues was also investigated. The data were analyzed using the Mann-Whitney U test, Kaplan-Meier log rank tests, Cox proportional hazard regression models and Fisher's exact tests. The median serum PN level in patients with CCA was significantly increased compared with that in healthy controls, patients with benign liver diseases and patients with breast cancer (all P<0.05). Using an optimal threshold value of 94 ng/ml PN, the diagnostic values for CCA compared with other conditions demonstrated a sensitivity level of 0.38 [95% confidence interval (CI), 0.27-0.51], specificity of 0.90 (95% CI, 0.81-0.96), accuracy of 0.66 (95% CI, 0.58-0.74), positive predictive value of 0.76 (95% CI, 0.59-0.89) and negative predictive value of 0.63 (95% CI, 0.53-0.72) (P<0.001). Furthermore, PN stain in stromal fibroblasts in CCA tissues was associated with serum PN levels (P=0.001), and patients with CCA were classified as low (≤94 ng/ml) or high PN (>94 ng/ml) accordingly. High serum and tissue PN levels were significantly associated with reduced survival rate (P<0.001 and P=0.033, respectively). Serum PN was an independent prognostic factor with a hazard ratio of 3.197 (P=0.001). In conclusion, serum PN may be used to divide patients with intrahepatic CCA into high and low PN groups. Elevated serum PN may be utilized as a marker of poor prognosis in patients with CCA.

High-level expression of periostin is significantly correlated with tumour angiogenesis and poor prognosis in osteosarcoma

Periostin (PN), originally named as osteoblast-specific factor-2 (OSF-2), has been involved in regulating adhesion and differentiation of osteoblasts. Recently many studies have shown that high-level expression of PN is correlated significantly with tumour angiogenesis and prognosis in many kinds of human cancer. However, whether and how periostin expression influences prognosis in osteosarcoma remains unknown. This study aimed to examine the expression of PN in patients with osteosarcoma and explore the relationship of PN expression with clinicopathologic factors, tumour angiogenesis and prognosis. Immunohistochemistry was performed to determine the expression of PN in osteosarcoma and osteochondroma respectively. Vascular endothelial growth factor (VEGF) and CD34 were also examined in tissues from the osteosarcoma patients mentioned above. The results showed that PN expression was significantly (P < 0.05) higher in osteosarcoma (80.9%) than in osteochondroma (14.7%). Increased PN protein expression was associated with histological subtype (P = 0.000), Enneking stage (P = 0.027) and tumour size (P = 0.009). The result also showed that high expression of PN correlated with VEGF expression (r = 0.285; P = 0.019) and that tumours with PN-positive expression significantly had higher microvessal density (44.6 ± 13.7 vs. 20.6 ± 6.5; P = 0.000) compared to those in normal bone tissues. Additionally, the expression of PN was found to be an independent prognostic factor in osteosarcoma patients. In conclusion, our findings suggest that PN may have an important role in tumour progression and may be used as a prognostic biomarker for patients with osteosarcoma.

Periostin Facilitates the Epithelial-Mesenchymal Transition of Endometrial Epithelial Cells through ILK-Akt Signaling Pathway

Although periostin was confirmed to facilitate the pathogenesis of endometriosis by enhancing the migration, invasion, and adhesion of human endometrial stromal cells (ESCs), its effect on the endometrial epithelial cells (EECs) is still unknown. The current study aimed to determine whether periostin enhanced the epithelial-mesenchymal transition (EMT) of EECs. EECs were isolated from 12 women with endometriosis. The migration and invasion abilities of EECs were evaluated by transwell assays. Expressions of proteins were detected by western blot. After treatment with periostin, the migration and invasion abilities of EECs were enhanced. Additionally, E-cadherin and keratin were downregulated while N-cadherin and vimentin were upregulated in EECs. Simultaneously, levels of ILK, p-Akt, slug, and Zeb1 were all upregulated in EECs. After silencing the expression of ILK in EECs, levels of p-Akt, slug, Zeb1, N-cadherin, and vimentin were downregulated while E-cadherin and keratin were upregulated. Although periostin weakened the above effects in EECs after silencing the expression of ILK, it failed to induce the EMT of EECs. Thus, periostin enhanced invasion and migration abilities of EECs and facilitated the EMT of EECs through ILK-Akt signaling pathway. Playing a pivotal role in the pathogenesis of endometriosis, periostin may be a new clinical therapy target for endometriosis.

Promotion of periostin expression contributes to the migration of Schwann cells

Neuregulin ligands and their ErbB receptors are important for the development of Schwann cells, the glial cells of the peripheral nervous system (PNS). ErbB3 deficiency is characterized by a complete loss of Schwann cells along axons of the peripheral nerves, impaired fasciculation and neuronal cell death. We performed comparative gene expression analysis of dorsal root ganglia (DRG) explant cultures from ErbB3-deficient and wild-type mice in order to identify genes that are involved in Schwann cell development and migration. The extracellular matrix (ECM) gene periostin was found to exhibit the most prominent down regulation in ErbB3-deficient DRG. Expression analysis revealed that the periostin-expressing cell population in the PNS corresponds to Schwann cell precursors and Schwann cells, and is particularly high in migratory Schwann cells. Furthermore, stimulation of Schwann cells with neuregulin-1 (NRG1) or transforming growth factor β (TGFβ-1) resulted in an upregulation of periostin expression. Interestingly, DRG explant cultures of periostin-deficient mice revealed a significant reduction of the number of migrating Schwann cells. These data demonstrate that the expression of periostin is stimulated by ErbB ligand NRG1 and influences the migration of Schwann cell precursors.

Causal Modeling of Cancer-Stromal Communication Identifies PAPPA as a Novel Stroma-Secreted Factor Activating NFκB Signaling in Hepatocellular Carcinoma

Inter-cellular communication with stromal cells is vital for cancer cells. Molecules involved in the communication are potential drug targets. To identify them systematically, we applied a systems level analysis that combined reverse network engineering with causal effect estimation. Using only observational transcriptome profiles we searched for paracrine factors sending messages from activated hepatic stellate cells (HSC) to hepatocellular carcinoma (HCC) cells. We condensed these messages to predict ten proteins that, acting in concert, cause the majority of the gene expression changes observed in HCC cells. Among the 10 paracrine factors were both known and unknown cancer promoting stromal factors, the former including Placental Growth Factor (PGF) and Periostin (POSTN), while Pregnancy-Associated Plasma Protein A (PAPPA) was among the latter. Further support for the predicted effect of PAPPA on HCC cells came from both in vitro studies that showed PAPPA to contribute to the activation of NFκB signaling, and clinical data, which linked higher expression levels of PAPPA to advanced stage HCC. In summary, this study demonstrates the potential of causal modeling in combination with a condensation step borrowed from gene set analysis [Model-based Gene Set Analysis (MGSA)] in the identification of stromal signaling molecules influencing the cancer phenotype.

All living cells rely on communication with other cells to ensure their function and survival. Molecular signals are sent among cells of the same cell type and from cells of one cell type to another. In cancer, not only the cancer cells themselves are responsible for the malignancy, but also stromal (non-cancerous) cells and the molecular signals they send to cancer cells are important factors that determine the severity and outcome of the disease. Therefore, the identification of stromal signals and their influence on cancer cells is important for the development of novel treatment strategies. With a computational systems biology model of stroma-cancer cell communication, we have compiled a set of ten proteins secreted by stromal cells that shape the cancer phenotype. Most importantly, our causal analysis uncovered Pregnancy-Associated Plasma Protein A (PAPPA) as a novel paracrine inducer of the pro-tumorigenic NFκB signaling pathway. In liver cancer patients, higher levels of PAPPA protein indicate a more progressed tumor stage, confirming its clinical relevance.

Periostin in intrahepatic cholangiocarcinoma: pathobiological insights and clinical implications

Periostin is a modular glycoprotein frequently observed to be a major constituent of the extracellular milieu of mass-forming intrahepatic cholangiocarcinoma and other desmoplastic malignant tumors. In intrahepatic cholangiocarcinoma, as well as in desmoplastic pancreatic ductal adenocarcinoma, periostin is overexpressed and hypersecreted in large part, if not exclusively, by cancer-associated fibroblasts within the tumor stroma. Through its interaction with specific components of the extracellular tumor matrix, particularly collagen type I and tenascin-C, and with cell surface receptors, notably integrins leading to activation of the Akt and FAK signaling pathways, this TGF-β family-inducible matricellular protein appears to be functioning as a key extracellular matrix molecule regulating such critically important and diverse malignant tumor behaviors as tumor fibrogenesis and desmoplasia, invasive malignant cell growth, chemoresistance, and metastatic colonization. This review will discuss current evidence and basic molecular mechanisms implicating periostin as a mediator of intrahepatic cholangiocarcinoma invasive growth. In addition, its significance as a potential prognostic biomarker for intrahepatic cholangiocarcinoma patients, as well as future possibilities and challenges as a molecular target for cholangiocarcinoma therapy and/or prevention, will be critically evaluated.

Circulating periostin levels in patients with AS: association with clinical and radiographic variables, inflammatory markers and molecules involved in bone formation

OBJECTIVE

The aim of this study was to evaluate serum periostin levels in patients with AS in comparison with healthy controls as well as their association with clinical, inflammatory and radiographic parameters and molecules involved in bone formation.

METHODS

Serum samples for periostin, total Dickkopf-1 (Dkk-1), sclerostin, VEGF and inflammatory markers were obtained from 65 TNF inhibitor-naive patients with AS. The BASDAI, BASFI, modified Stoke AS Spine Score and BASRI for the spine (BASRI-s) were assessed for each patient. Serum periostin levels were also measured in 36 sex-, age- and BMI-matched controls.

RESULTS

Serum periostin levels were significantly lower in AS patients compared with controls [234.4 pg/ml (s.e.m. 7.5) vs 291.4 (s.e.m. 8.3), respectively; P < 0.001]. Periostin levels were higher in AS patients with elevated CRP (P = 0.005), high BASDAI (P = 0.014) and low BASRI-s (P = 0.033) and were correlated with BMI (r = -0.304, P = 0.014), ESR (r = 0.395, P = 0.001), CRP (r = 0.413, P = 0.001), BASRI-s (r = -0.242, P = 0.047) and sclerostin (r = -0.280, P = 0.024). In multiple regression analysis, periostin levels were an independent variable of CRP (β = 0.160, P = 0.009) and sclerostin levels (β = -0.311, P = 0.012).

CONCLUSION

Our data suggest that periostin levels are low in patients with AS. Among AS patients, periostin levels are higher in those with higher disease activity, higher systemic inflammation and less extensive radiographic damage. Periostin is independently associated with CRP and sclerostin levels.

High expression of periostin is dramatically associated with metastatic potential and poor prognosis of patients with osteosarcoma

Background

Recent studies have found that periostin (PN), as a kind of secreted glycoprotein, is closely related to the metastatic potential and prognosis of many kinds of tumors. This study aimed to examine the expression of PN in patients with osteosarcoma and explore the relationship of PN expression with clinicopathologic factors and prognosis.

Methods

PN was detected by histopathological and immunohistochemical methods in 62 cases of osteosarcoma and 62 of osteochondroma. Detailed pathological and clinical data were collected by reviewing medical records.

Results

The results showed that increased PN protein expression was prevalent in osteosarcoma and was significantly associated with pathologic subtype (P =0.000), tumor size (P =0.016) and Enneking stage (P =0.047). Additionally, expression of PN was found to be an independent prognostic factor in osteosarcoma patients. High expression of PN protein is closely correlated to the tumor progression and poor survival of osteosarcoma.

Conclusions

Our data suggest that PN is a promising biomarker for identifying individuals with poor prognostic potential and suggests its possible use as a prognostic marker in patients with osteosarcoma.

Tumor-Induced Osteomalacia: Increased Level of FGF-23 in a Patient with a Phosphaturic Mesenchymal Tumor at the Tibia Expressing Periostin

In our case, a 45-year-old male patient had multiple fractures accompanied by hypophosphatemia. FGF-23 levels were significantly increased, and total body magnetic resonance imaging (MRI) revealed a tumor mass located at the distal tibia leading to the diagnosis of tumor-induced osteomalacia (TIO). After resection of the tumor, hypophosphatemia and the increased levels of FGF-23 normalized within a few days. Subsequent microscopic examination and immunohistochemical analysis revealed a phosphaturic mesenchymal tumor mixed connective tissue variant (PMTMCT) showing a positive expression of somatostatin receptor 2A (SSTR2A), CD68, and Periostin. Electron microscopy demonstrated a poorly differentiated mesenchymal tumor with a multifocal giant cell component and evidence of neurosecretory-granules. However, the resected margins showed no tumor-free tissue, and therefore a subsequent postoperative radiotherapy was performed. The patient is still in complete remission after 34 months. Tumor resection of PMTMCTs is the therapy of choice. Subsequent radiotherapy in case of incompletely resected tumors can be an important option to avoid recurrence or metastasis even though this occurs rarely. The prognostic value of expression of Periostin has to be evaluated more precisely in a larger series of patients with TIO.

Quantitative proteomics analysis of early recurrence/metastasis of huge hepatocellular carcinoma following radical resection

BACKGROUND

Hepatic resection is the preferred treatment for huge hepatocellular carcinoma (>10 cm in diameter; H-HCC). However, the patients with H-HCC suffer from poor prognosis due to the early recurrence/metastasis. The underlying mechanism of H-HCC's early recurrence/metastasis is currently not well understood.

RESULTS

Here, we describe an Isobaric Tags for relative and absolute quantification (iTRAQ)-based quantitative proteomics approach to analyze the early recurrence/metastasis related proteins of H-HCC after radical resection through multidimensional chromatography coupled with tandem mass spectrometry (2DLC-MS/MS). The different protein expression profiles between the early recurrence/metastasis within 6 months(R/M≤6months) and late recurrence/metastasis within 6-12 months after surgery (R/M6-12months) were confirmed and might reveal different underlying molecular mechanisms. We identified 44 and 49 significantly differentially expressed proteins in the R/M≤6months group and the R/M6-12months group compared to the group who had no recurrence within 2 years post surgery (the NR/M group), respectively. Moreover, among those proteins, S100A12 and AMACR were down regulated in the R/M≤6months group but up-regulated in the R/M6-12months group; and this regulation was further confirmed in mRNA and protein level by Q-PCR, Western-Blot and Immunohistochemistry (IHC).

CONCLUSIONS

This current study presents the first proteomic profile of the early recurrence/metastasis of H-HCC. The results suggest that S100A12 and AMACR might be potential prognostic markers for predicting the early recurrence/metastasis of H-HCC after hepatectomy.

Priming cancer cells for drug resistance: role of the fibroblast niche

Conventional and targeted chemotherapies remain integral strategies to treat solid tumors. Despite the large number of anti-cancer drugs available, chemotherapy does not completely eradicate disease. Disease recurrence and the growth of drug resistant tumors remain significant problems in anti-cancer treatment. To develop more effective treatment strategies, it is important to understand the underlying cellular and molecular mechanisms of drug resistance. It is generally accepted that cancer cells do not function alone, but evolve through interactions with the surrounding tumor microenvironment. As key cellular components of the tumor microenvironment, fibroblasts regulate the growth and progression of many solid tumors. Emerging studies demonstrate that fibroblasts secrete a multitude of factors that enable cancer cells to become drug resistant. This review will explore how fibroblast secretion of soluble factors act on cancer cells to enhance cancer cell survival and cancer stem cell renewal, contributing to the development of drug resistant cancer.

High preoparative levels of serum periostin are associated with poor prognosis in patients with hepatocellular carcinoma after hepatectomy

AIMS

Periostin (POSTN) is implicated in cancer development and progression. The aim of this study was to evaluate the diagnostic and prognostic significance of serum POSTN in patients with hepatocellular carcinoma (HCC) receiving curative surgery.

METHODS

Enzyme-linked immunosorbent assay was performed to determine serum POSTN levels in 69 healthy volunteers, 30 patients with hepatolithiasis, 27 patients with cirrhosis, and 56 HCC patients. The relationships between serum POSTN and clinicopathologic features were analyzed. Receiver operating characteristics analysis was used to calculate diagnostic accuracy of serum POSTN, serum alpha-fetoprotein (AFP), and their combination. The prognostic impact of serum POSTN on overall survival (OS) and relapse-free survival (RFS) was also investigated.

RESULTS

The median serum POSTN level was significantly (P < 0.05) increased in HCC patients, compared to healthy controls, patients with hepatolithiasis, and patients with liver cirrhosis. Elevated serum POSTN was only significantly associated with Edmondson grade (P = 0.007). The combination of serum POSTN and AFP had a markedly higher area under the curve (0.805 (95% confidence interval [CI]: 0.677-0.932)) than POSTN (0.582 (95% CI: 0.427-0.736)) or AFP (0.655 (95% CI: 0.504-0.806)) alone. Kaplan-Meier analysis indicated that elevated serum POSTN was associated with OS (P = 0.031) and RFS (P = 0.027). Moreover, multivariate analysis revealed elevated serum POSTN as an independent poor prognostic marker for OS and RFS.

CONCLUSIONS

Preoperative serum POSTN has limited diagnostic value in distinguishing HCC from non-malignant liver diseases, but serves as independent prognostic biomarker in HCC patients.

Periostin mediates the increased pro-angiogenic activity of gastric cancer cells under hypoxic conditions

This study was conducted to investigate the biological role of periostin in gastric cancer (GC) under hypoxia. Western blot analysis revealed that along with an upregulation of hypoxia-inducible factor-1alpha, there was a time-dependent induction of periostin in MKN-45 cells under hypoxia (2% O2 ), increasing by eightfold as compared to normoxic cells. Pretreatment with 30 µM PD98059, an inhibitor of ERK1/2, significantly reduced hypoxia-stimulated periostin expression (P < 0.01). Periostin knockdown in MKN-45 cells was achieved by specific small interfering RNA (siRNA). The conditioned medium from periostin siRNA-transfected MKN-45 cells induced significantly less (P < 0.01) endothelial tube formation than control siRNA-transfected cells. Additionally, periostin silencing markedly decreased the mRNA expression and secretion of vascular endothelial growth factor (VEGF) in hypoxic MKN-45 cells. Thus, our data suggest that periostin is a hypoxia-response gene and mediates a cross talk between GC and endothelial cells under hypoxia, partially through regulation of the VEGF expression.