Expression of periostin in human breast cancer

Periostin drives extracellular matrix degradation, stemness, and chemoresistance by activating the MAPK/ERK signaling pathway in triple-negative breast cancer cells

BACKGROUND

Adipose tissue, which is mainly composed of adipocytes, is a crucial component of the tumor microenvironment, particularly in breast cancer. Adipocytes surround breast cancer cells and may participate in cell‒cell interactions in the breast microenvironment. However, little is currently known about how adipocytes influence the biological behavior of the surrounding breast cancer cells. Hence, this study sought to investigate the role and underlying mechanisms of periostin in triple-negative breast cancer (TNBC) cells cocultured with adipogenic conditioned medium (ACM) and palmitic acid (PA).

METHODS

Human TNBC cell lines (MDA‒MB‒231 and SUM159PT) were treated with ACM and PA, then the expression of periostin, matrix metalloproteinases (MMPs) and stemness-related molecules were assessed by Western blotting and RT‒qPCR. The cellular viability was assessed using CCK‒8 assay. Plasmid transfection, RNA sequencing, and pathway inhibitor were used to explore the specific mechanisms of periostin.

RESULTS

ACM and PA elevated the expression of both MMPs and stemness-related molecules in TNBCs. MMPs can promote tumor cell infiltration and migration by degrading the extracellular matrix, and stemness expression increases the development of tumor chemoresistance. Additionally, ACM and PA increased periostin expression, while inhibiting periostin disrupted the involvement of ACM and PA in promoting extracellular matrix degradation, stemness, and chemoresistance in TNBCs. Furthermore, this study found that periostin promoted TNBC progression by activating the MAPK/ERK signaling pathway and that inhibition of MAPK/ERK signaling reduced the phenotype caused by periostin upregulation in TNBCs treated with ACM or PA. Finally, the present results showed that the high expression of POSTN, which encodes periostin, was substantially related to worse survival in TNBC patients.

CONCLUSIONS

The results of the study elucidated for the first time how periostin is the key protein secreted in TNBCs in response to the adipocyte-regulated tumor microenvironment, while periostin-neutralizing antibodies may serve as potential therapeutic agents in relation to TNBC progression.

Periostin derived from cancer-associated fibroblasts promotes esophageal squamous cell carcinoma progression via ADAM17 activation

Periostin (POSTN) is a matricellular protein that was originally identified in osteoblasts. Past studies have shown that POSTN is also preferentially expressed in cancer-associated fibroblasts (CAFs) in various types of cancer. We previously demonstrated that the increased expression of POSTN in stromal tissues is associated with an unfavorable clinical outcome in esophageal squamous cell carcinoma (ESCC) patients. In this study, we aimed to elucidate the role of POSNT in ESCC progression and its underlying molecular mechanism. We found that POSTN is predominantly produced by CAFs in ESCC tissues, and that CAFs-cultured media significantly promoted the migration, invasion, proliferation, and colony formation of ESCC cell lines in a POSTN-dependent manner. In ESCC cells, POSTN increased the phosphorylation of ERK1/2 and stimulated the expression and activity of a disintegrin and metalloproteinase 17 (ADAM17), which is critically involved in tumorigenesis and tumor progression. The effects of POSTN on ESCC cells were suppressed by interfering with the binding of POSTN to integrin αvβ3 or αvβ5 using neutralizing antibody against POSTN. Taken together, our data show that CAFs-derived POSTN stimulates ADAM17 activity through activation of the integrin αvβ3 or αvβ5-ERK1/2 pathway and thereby contributes to the progression of ESCC.

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.

Tumor- and Osteoblast-Derived Periostin in Prostate Cancer bone Metastases

Exploring the biological function of periostin (POSTN) in prostate cancer (PCa) bone metastasis is of importance. It was observed that the expression of POSTN was high in PCa, especially highest in PCa metastasized to bone. In this study, we found that inhibiting POSTN in PCa cells could significantly alleviate PCa bone metastasis in vivo, suggesting POSTN is a promising therapeutic target. Since, due to the secreted expression of POSTN in osteoblasts and PCa, we hypothesized the positive feedback loop between osteoblasts and PCa mediated by POSTN in PCa bone metastasis. The in vitro experiments demonstrated that osteoblast-derived POSTN promoted PCa cell proliferation and invasion and PCa cell-derived POSTN promotes proliferation of osteoblasts. Furthermore, we found that POSTN regulated PCa and osteoblast function through integrin receptors. Finally, ¹⁸F-Alfatide II was used as the molecule probe of integrin αvβ3 in PET-CT, revealing high intake in metastatic lesions. Our findings together indicate that targeting POSTN in PCa cells as well as in the osteoblastic may be an effective treatment for PCa bone metastasis.

Expression of Periostin in Mammary Cancer Cells of Female Dogs

BACKGROUND/AIM

Periostin (POSTN) has a significant role in proliferation and migration of tumour cells as well as tumour progression. This study aimed to determinate POSTN expression in cancer cells in malignant and benign tumours of the mammary gland in female dogs.

MATERIALS AND METHODS

All together 83 cancers, 24 adenomas and 7 unchanged fragments of the mammary glands of bitches were investigated. Immunohistochemistry was performed using anti-POSTN, Ki-67 and HER2 antibodies.

RESULTS

POSTN expression was observed in cancer cells in 31.3% of malignancies and 12.5% of benign tumours. A significantly positive correlation between expression of POSTN in cancer cells and the degree of histological malignancy, expression of Ki-67 antigen and expression of POSTN in CAFs was found.

CONCLUSION

The obtained results suggest the possible participation of POSTN in the process of carcinogenesis and progression of mammary tumors in bitches.

Comprehensive genomic analysis contrasting primary colorectal cancer and matched liver metastases

Recent studies have revealed that colorectal cancer (CRC) displays intratumor genetic heterogeneity, and that the cancer microenvironment plays an important role in the proliferation, invasion and metastasis of CRC. The present study performed genomic analysis on paired primary CRC and synchronous colorectal liver metastasis (CRLM) tissues collected from 22 patients using whole-exome sequencing, cancer gene panels and microarray gene expression profiling. In addition, immunohistochemical analysis was used to confirm the protein expression levels of genes identified as highly expressed in CRLM by DNA microarray analysis. The present study identified 10 genes that were highly expressed in CRLM compared with in CRC, from 36,022 probes obtained from primary CRC, CRLM and normal liver tissues by gene expression analysis with DNA microarrays. Of the 10 genes identified, five were classified as encoding 'matricellular proteins' [(osteopontin, periostin, thrombospondin-2, matrix Gla protein (MGP) and glycoprotein nonmetastatic melanoma protein B (GPNMB)] and were selected for immunohistochemical analysis. Osteopontin was strongly expressed in CRLM (6 of 22 cases: 27.3%), but not in CRC (0 of 22: 0%; P=0.02). Periostin also exhibited strong immunoreactivity in CRLM (17 of 22: 68.2%) compared with in CRC (7 of 22: 31.8%; P=0.006). Thrombospondin-2 exhibited strong immunoreactivity in both CRC and CRLM (54.5% in CRC, 45.5% in CRLM; P=0.55). GPNMB and MGP were rarely positive for both CRC and CRLM. A comparison of immunoreactive positive factors for these five genes revealed the complexities of gene expression in CRLM. Of the cases examined, 16 (72.7%) cases of CRC showed zero or only one positive immunoreactive factor. By contrast, CRLM showed more frequent and multiple immunoreactive factors; for example, 16 cases (72.7%) shared two or more factors, which was statistically more frequent than in CRC (P=0.007). The present study revealed the genomic heterogeneity between paired primary CRC and CRLM, in terms of cancer cell microenvironment. This finding may lead to novel diagnostic and therapeutic targets in the era of genome-guided personalized cancer treatment.

Development of an engineered peptide antagonist against periostin to overcome doxorubicin resistance in breast cancer

Background

Chemoresistance is one of the main problems in treatment of cancer. Periostin (PN) is a stromal protein which is mostly secreted from cancer associated fibroblasts in the tumor microenvironment and can promote cancer progression including cell survival, metastasis, and chemoresistance. The main objective of this study was to develop an anti-PN peptide from the bacteriophage library to overcome PN effects in breast cancer (BCA) cells.

Methods

A twelve amino acids bacteriophage display library was used for biopanning against the PN active site. A selected clone was sequenced and analyzed for peptide primary structure. A peptide was synthesized and tested for the binding affinity to PN. PN effects including a proliferation, migration and a drug sensitivity test were performed using PN overexpression BCA cells or PN treatment and inhibited by an anti-PN peptide. An intracellular signaling mechanism of inhibition was studied by western blot analysis. Lastly, PN expressions in BCA patients were analyzed along with clinical data.

Results

The results showed that a candidate anti-PN peptide was synthesized and showed affinity binding to PN. PN could increase proliferation and migration of BCA cells and these effects could be inhibited by an anti-PN peptide. There was significant resistance to doxorubicin in PN-overexpressed BCA cells and this effect could be reversed by an anti-PN peptide in associations with phosphorylation of AKT and expression of survivin. In BCA patients, serum PN showed a correlation with tissue PN expression but there was no significant correlation with clinical data.

Conclusions

This finding supports that anti-PN peptide is expected to be used in the development of peptide therapy to reduce PN-induced chemoresistance in BCA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07761-w.

Periostin

Rationale:

POSTN (Periostin) is an ECM (extracellular matrix) protein involved in tissue remodeling in response to injury and a contributing factor in tumorigenesis, suggesting that POSTN plays a role in the pathogenesis of pulmonary hypertension (PH).

Objective:

We aimed to gain insight into the mechanistic contribution of POSTN in experimental mouse models of PH and correlate these findings with PH in humans.

Methods and Results:

We used genetic epistasis approaches in human pulmonary artery endothelial cells (hPAECs), human pulmonary artery smooth muscle cells, and experimental mouse models of PH (Sugen 5416/hypoxia or chronic hypoxia) to discern the role of POSTN and its relationship to HIF (hypoxia-inducible factor)-1α signaling. We found that POSTN expression was correlated with the extent of PH in mouse models and in humans. Decreasing POSTN improved hemodynamic and cardiac responses in PH mice, blunted the release of growth factors and HIF-1α, and reversed the downregulated BMPR (bone morphogenetic protein receptor)-2 expression in hPAECs from patients with PH, whereas increasing POSTIN had the opposite effects and induced a hyperproliferative and promigratory phenotype in both hPAECs and human pulmonary artery smooth muscle cells. Overexpression of POSTN-induced activation of HIFs and increased the production of ET (endothelin)-1 and VEGF (vascular endothelial growth factor) in hPAECs. SiRNA-mediated knockdown of HIF-1α abolished the proangiogenic effect of POSTN. Blockade of TrkB (tyrosine kinase receptor B) attenuated the effect of POSTN on HIF-1α expression, while inhibition of HIF-1α reduced the expression of POSTN and TrkB. These results suggest that hPAECs produce POSTN via a HIF-1α-dependent mechanism.

Conclusions:

Our study reveals that POSTN expression is increased in human and animal models of PH and fosters PH development via a positive feedback loop between HIF-1α and POSTN during hypoxia. We propose that manipulating POSTIN expression may be an efficacious therapeutic target in the treatment of PH. Our results also suggest that POSTN may serve as a biomarker to estimate the severity of PH.

Serum and placental periostin levels in women with early pregnancy loss

OBJECTIVES

Periostin is secreted from the placenta in the embryonic period and it is emphasized that it may be involved in endometrial implantation. In this study, we aimed to investigate periostin serum levels and placental tissue expression in first trimester pregnancy losses.

STUDY DESIGN

In this prospective case-control study, 30 patients who underwent dilatation and curettage with first trimester spontaneous abortion (<10 weeks of gestation) were included in the study group and 30 patients who had voluntary pregnancy termination (<10 gestational weeks) were included in the control group. Serum samples collected from the study and control groups were analyzed usingenzyme-linkedimmunosorbent assay (ELISA), and trophoblastic and decidual tissues were examined using immunohistochemical staining with streptavidin-biotin-peroxidase techniques.

RESULTS

There were no significant differences between the groups in terms of age, gravida status, parity number, gestational week, and number of previous abortions. In the spontaneous abortion group, the serum level of periostin was significantly lower than in the voluntary termination group (6.56 ± 4.16 pg/mLvs. 9.51 ± 4.52 pg/mL, p = 0.03). There was no significant difference between the two groups in terms of periostin expression in decidual and trophoblastic tissue (p = 0.617, p = 0.274, p = 0.497).

CONCLUSION

Periostin serum levels were significantly reduced in patients with spontaneous pregnancy loss. Periostin can be used as a predictive marker for the success of endometrial implantation.

Tissue engineering applications in breast cancer

In Iran, breast cancer (BC) is the most prevalent cancer among women. The standard treatment for this cancer is partial or total removal of breast tissue, followed by chemotherapy and radiation. Tissue engineering (TE) has made new treatments for tissue loss in these patients by creating functional substitutes in the laboratory. In addition, cancer biology combined with TE provides a new strategy for evaluation of anti-BC therapy. Several innovations in TE have led to the design of scaffold or matrix based culture systems that more closely mimic the native extracellular matrix (ECM). Currently, engineered three-dimensional (3D) cultures are being developed for modelling of the tumour microenvironment. These 3D cultures fulfil the need for in vitro approaches that allow an accurate study of the molecular mechanisms and a better analysis of the drugs effect. In the present study, we review recent developments in utilising of TE in BC. Moreover, this review describes achievements of Iranian researchers in the field of breast TE.

High serum levels of periostin are associated with a poor survival in breast cancer

PURPOSE

Periostin is a secreted extracellular matrix protein, which was originally described in osteoblasts. It supports osteoblastic differentiation and bone formation and has been implicated in the pathogenesis of several human malignancies, including breast cancer. However, little is known about the prognostic value of serum periostin levels in breast cancer.

METHODS

In this study, we analyzed serum levels of periostin in a cohort of 509 primary, non-metastatic breast cancer patients. Disseminated tumor cell (DTC) status was determined using bone marrow aspirates obtained from the anterior iliac crests. Periostin levels were stratified according to several clinical parameters and Pearson correlation analyses were performed. Kaplan-Meier survival curves were assessed by using the log-rank (Mantel-Cox) test. To identify prognostic factors, multivariate Cox regression analyses were used.

RESULTS

Mean serum levels of periostin were 505 ± 179 pmol/l. In older patients (> 60 years), periostin serum levels were significantly increased compared to younger patients (540 ± 184 pmol/l vs. 469 ± 167 pmol/l; p < 0.0001) and age was positively correlated with periostin expression (p < 0.0001). When stratifying the cohort according to periostin serum concentrations, the overall and breast cancer-specific mortality were significantly higher in those patients with high serum periostin (above median) compared to those with low periostin during a mean follow-up of 8.5 years (17.7% vs. 11.4% breast cancer-specific death; p = 0.03; hazard ratio 1.65). Periostin was confirmed to be an independent prognostic marker for breast cancer-specific survival (p = 0.017; hazard ratio 1.79). No significant differences in serum periostin were observed when stratifying the patients according to their DTC status.

CONCLUSIONS

Our findings emphasize the relevance of periostin in breast cancer and reveal serum periostin as a potential marker for disease prediction, independent on the presence of micrometastases.

Periostin induces epithelial‑to‑mesenchymal transition via the integrin α5β1/TWIST‑2 axis in cholangiocarcinoma

Periostin (PN) (also known as osteoblast-specific factor OSF-2) is a protein that in humans is encoded by the POSTN gene and has been correlated with a reduced survival of cholangiocarcinoma (CCA) patients, with the well-known effect of inducing epithelial-to-mesenchymal transition (EMT). The present study investigated the effect of PN, through integrin (ITG)α5β1, in EMT-mediated CCA aggressiveness. The alterations in EMT-related gene and protein expression were investigated by real-time PCR, western blot analysis and zymogram. The effects of PN on migration and the level of TWIST-2 were assessed in CCA cells with and without siITGα5 transfection. PN was found to induce CCA cell migration and EMT features, including increments in Twist-related protein 2 (TWIST-2), zinc finger protein SNAI1 (SNAIL-1), α-smooth muscle actin (ASMA), vimentin (VIM) and matrix metallopeptidase 9 (MMP-9), and a reduction in cytokeratin 19 (CK-19) together with cytoplasmic translocation of E-cadherin (CDH-1). Additionally, PN markedly induced MMP-9 activity. TWIST-2 was significantly induced in PN-treated CCA cells; this effect was attenuated in the ITGα5β1-knockdown cells and corresponded to reduced migration of the cancer cells. These results indicated that PN induced CCA migration through ITGα5β1/TWIST-2-mediated EMT. Moreover, clinical samples from CCA patients showed that higher levels of TWIST-2 were significantly correlated with shorter survival time. In conclusion, the ITGα5β1-mediated TWIST-2 signaling pathway regulates PN-induced EMT in CCA progression, and TWIST-2 is a prognostic marker of poor survival in CCA patients.

The Tumor Microenvironment: Focus on Extracellular Matrix

The extracellular matrix (ECM) regulates the development and maintains tissue homeostasis. The ECM is composed of a complex network of molecules presenting distinct biochemical properties to regulate cell growth, survival, motility, and differentiation. Among their components, proteoglycans (PGs) are considered one of the main components of ECM. Its composition, biomechanics, and anisotropy are exquisitely tuned to reflect the physiological state of the tissue. The loss of ECM's homeostasis is seen as one of the hallmarks of cancer and, typically, defines transitional events in tumor progression and metastasis. In this chapter, we discuss the types of proteoglycans and their roles in cancer. It has been observed that the amount of some ECM components is increased, while others are decreased, depending on the type of tumor. However, both conditions corroborate with tumor progression and malignancy. Therefore, ECM components have an increasingly important role in carcinogenesis and this leads us to believe that their understanding may be a key in the discovery of new anti-tumor therapies. In this book, the main ECM components will be discussed in more detail in each chapter.

Expression of Osteoblast-Specific Factor 2 (OSF-2, Periostin) Is Associated with Drug Resistance in Ovarian Cancer Cell Lines

One of the main obstacles to the effective treatment of ovarian cancer patients continues to be the drug resistance of cancer cells. Osteoblast-Specific Factor 2 (OSF-2, Periostin) is a secreted extracellular matrix protein (ECM) expressed in fibroblasts during bone and teeth development. Expression of OSF-2 has been also related to the progression and drug resistance of different tumors. The present study investigated the role of OSF-2 by evaluating its expression in the primary serous ovarian cancer cell line, sensitive (W1) and resistant to doxorubicin (DOX) (W1DR) and methotrexate (MTX) (W1MR). The OSF-2 transcript (real-time PCR analysis), protein expression in cell lysates and cell culture medium (western blot), and expression of the OSF-2 protein in cell lines (immunofluorescence) were investigated in this study. Increased expression of OSF-2 mRNA was observed in drug-resistant cells and followed by increased protein expression in cell culture media of drug-resistant cell lines. A subpopulation of ALDH1A1-positive cells was noted for W1DR and W1MR cell lines; however, no direct co-expression with OSF-2 was demonstrated. Both drugs induced OSF-2 expression after a short period of exposure of the drug-sensitive cell line to DOX and MTX. The obtained results indicate that OSF-2 expression might be associated with the development of DOX and MTX resistance in the primary serous W1 ovarian cancer cell line.

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 overexpression is associated with worse prognosis in nasopharyngeal carcinoma from endemic area: a cohort study

Purpose

Nasopharyngeal carcinoma (NPC) is a heterogeneous disease. We searched for genes that function in cell adhesion in GSE12452, a published transcriptomic database. We found that POSTN, which encodes periostin (POSTN), was significantly upregulated in NPC tumorigenesis. Herein, we sought to analyze the expression of POSTN and its prognostic significances in patients with NPC.

Materials and methods

In this single-institution retrospective study, we determined and analyzed POSTN expression by immunohistochemistry and H-score method, respectively, in 124 patients with NPC. The results indicated that POSTN expression was correlated with the clinicopathologic features, disease-specific survival (DSS), distant metastasis-free survival (DMFS), and local recurrence-free survival (LRFS) of NPC. We performed univariate and multivariate analyses to determinate the statistical significance.

Results

High POSTN expression was significantly associated with lymph node metastasis (p=0.004) and advanced American Joint Committee on Cancer (AJCC) stage (p=0.006). In univariate analysis, high POSTN expression served as a significant prognostic factor for worse DSS (p=0.0002), DMFS (p=0.0138), and LRFS (p=0.0028). In multivariate Cox regression analyses, which was adjusted for AJCC stages, POSTN expression was independently associated with cancer-related death (HR: 2.311; 95% CI: 1.327-4.027; p=0.003) and local tumor recurrence (HR: 3.187; 95% CI: 1.108-4.408; p=0.024).

Conclusion

High POSTN expression is associated with tumor aggressiveness and worse clinical outcomes in NPC, indicating that it may be a potential prognostic biomarker and a therapeutic target.

The Role of Periostin in Capsule Formation on Silicone Implants

Although silicone implants are widely used in breast and other reconstructive surgeries, the limited biocompatibility of these materials leads to severe complications, including capsular contracture. Here, we aimed to clarify the relationship between periostin and the process of capsule formation after in vivo implantation. Seven-week-old wild-type (WT) C57BL/6 mice and periostin-deficient mice were used. Round silicone implants were inserted into a subcutaneous pocket on the dorsum of the mice. After 8 weeks, the fibrous capsule around the implant was harvested and histologically examined to estimate capsular thickness and the number of inflammatory cells. Additionally, immunohistochemical analysis (periostin, α-SMA, and collagen type I) and western blotting (CTGF, TGF-β, VEGF, and MPO) were performed for a more detailed analysis of capsule formation. The capsules in periostin-knockout mice (PN-KO) were significantly thinner than those in WT mice. PN-KO mice showed significantly lower numbers of inflammatory cells than WT mice. Fibrous tissue formation markers (α-SMA, periostin, collagen type I, and CTGF) were significantly reduced in PN-KO mice. We also confirmed that inflammatory reaction and angiogenesis indicators (TGF-β, MPO, and VEGF) had lower expression in PN-KO mice. Inhibition of periostin could be important for suppressing capsule formation on silicone implants after in vivo implantation.

Charting the unexplored extracellular matrix in cancer

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

The interplay between extracellular matrix remodelling and kinase signalling in cancer progression and metastasis

The extracellular matrix (ECM) is a master regulator of cellular phenotype and behaviour. It plays a crucial role in both normal tissue homeostasis and complex diseases such as cancer. The interplay between the intrinsic factors of cancer cells themselves, including their genotype and signalling networks; and the extrinsic factors of the tumour stroma, such as the ECM and ECM remodelling; together determine the fate and behaviour of cancer cells. As a consequence, tumour progression, metastatic spread and response to therapy are ultimately controlled by ECM-driven fine-tuning of intracellular kinase signalling. The ability to target and uncouple this interaction presents an emerging and promising potential in the treatment of cancer.

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.

p73 promotes glioblastoma cell invasion by directly activating POSTN (periostin) expression

Glioblastoma Multiforme is one of the most highly metastatic cancers and constitutes 70% of all gliomas. Despite aggressive treatments these tumours have an exceptionally bad prognosis, mainly due to therapy resistance and tumour recurrence. Here we show that the transcription factor p73 confers an invasive phenotype by directly activating expression of POSTN (periostin, HGNC:16953) in glioblastoma cells. Knock down of endogenous p73 reduces invasiveness and chemo-resistance, and promotes differentiation in vitro. Using chromatin immunoprecipitation and reporter assays we demonstrate that POSTN, an integrin binding protein that has recently been shown to play a major role in metastasis, is a transcriptional target of TAp73. We further show that POSTN overexpression is sufficient to rescue the invasive phenotype of glioblastoma cells after p73 knock down. Additionally, bioinformatics analysis revealed that an intact p73/POSTN axis, where POSTN and p73 expression is correlated, predicts bad prognosis in several cancer types. Taken together, our results support a novel role of TAp73 in controlling glioblastoma cell invasion by regulating the expression of the matricellular protein POSTN.

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.

Role and underlying mechanisms of the interstitial protein periostin in the diagnosis and treatment of malignant tumors

Invasion and metastasis are the major characteristics of malignant tumors and are complex processes involving multiple genes. Gene regulation is a precise, large and complex biological control system, and its underlying mechanisms remain to be elucidated. Mesenchymal-specific genes are expressed primarily by mesenchymal cells, and the expression products of these genes are molecules with various structures and functions, including secreted proteins and extracellular matrix proteins. The periostin gene has been newly identified as a mesenchymal-specific gene and an extracellular-matrix secreted protein. Periostin is able to bind to various subtypes of integrin receptors on the surface of the cell membrane. This triggers relevant signal transduction pathways to alter the microenvironment of cancer cells in order to facilitate their survival, invasion, metastasis and angiogenesis as well as enhance the tolerance to hypoxia and chemicals. Therefore, periostin is associated with the grade of malignancy, level of invasion and prognosis of malignant tumors. The in-depth study of periostin may provide an effective marker for tumor diagnosis and prognosis, as well as a novel treatment target.

Periostin promotes migration and invasion of renal cell carcinoma through the integrin/focal adhesion kinase/c-Jun N-terminal kinase pathway

Periostin (POSTN) is an extracellular matrix protein which is overexpressed in a variety of cancers and has been related to tumorigenesis of renal cell carcinoma. However, the involvement of POSTN in renal cell carcinoma migration, invasion, and their underlying mechanisms has not been established. In this study, renal cell carcinoma cell lines stably overexpressing POSTN were established using a lentiviral vector, and the effects of POSTN on renal cell carcinoma cell migration and invasion were investigated. POSTN overexpression increased the migration and invasion capabilities of renal cell carcinoma cell lines as well as activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. Integrin α_vβ₃ and α_vβ₅ antibodies inhibited POSTN overexpression or recombinant POSTN-induced focal adhesion kinase activation, cell migration, and invasion. Furthermore, lentivirus-mediated focal adhesion kinase knockdown and c-Jun N-terminal kinase inhibitor reduced POSTN-enhanced phosphorylation of c-Jun N-terminal kinase, matrix metalloproteinase-9 and matrix metalloproteinase-2 expressions, cell migration, and invasion. Our research thus indicates that POSTN promotes renal cell carcinoma cell migration and invasion through interaction with integrins α_vβ₃ and α_vβ₅ and subsequent activation of the focal adhesion kinase/c-Jun N-terminal kinase pathway. These results suggest that POSTN plays a critical role in renal cell carcinoma metastasis and may represent a potential target for novel therapeutic approaches against renal cell carcinoma.

Targeted proteomics driven verification of biomarker candidates associated with breast cancer aggressiveness

Breast cancer is the most common and molecularly relatively well characterized malignant disease in women, however, its progression to metastatic cancer remains lethal for 78% of patients 5years after diagnosis. Novel markers could identify the high risk patients and their verification using quantitative methods is essential to overcome genetic, inter-tumor and intra-tumor variability and translate novel findings into cancer diagnosis and treatment. We recently identified 13 proteins associated with estrogen receptor, tumor grade and lymph node status, the key factors of breast cancer aggressiveness, using untargeted proteomics. Here we verified these findings in the same set of 96 tumors using targeted proteomics based on selected reaction monitoring with mTRAQ labeling (mTRAQ-SRM), transcriptomics and immunohistochemistry and validated in 5 independent sets of 715 patients using transcriptomics. We confirmed: (i) positive association of anterior gradient protein 2 homolog (AGR2) and periostin (POSTN) and negative association of annexin A1 (ANXA1) with estrogen receptor status; (ii) positive association of stathmin (STMN1), cofilin-1 (COF1), plasminogen activator inhibitor 1 RNA-binding protein (PAIRBP1) and negative associations of thrombospondin-2 (TSP2) and POSTN levels with tumor grade; and (iii) positive association of POSTN, alpha-actinin-4 (ACTN4) and STMN1 with lymph node status. This study highlights a panel of gene products that can contribute to breast cancer aggressiveness and metastasis, the understanding of which is important for development of more precise breast cancer treatment.

Aptamers: Promising Tools for the Detection of Circulating Tumor Cells

Circulating tumor cells (CTCs) are cells that shed from a primary tumor and freely circulate in the blood, retaining the ability to initiate metastasis and form a secondary tumor in distant organs in the body. CTCs reflect the molecular profile of the primary tumor, therefore studying CTCs can allow for an understanding of the mechanism of metastasis, and an opportunity to monitor the prognosis of cancer. Unfortunately, the detection of CTCs is a considerable challenge due to their low abundance in the bloodstream and the lack of consistent markers present to recognize these cells. The aim of this review is to summarize some of the aptamer-based affinity methods for the detection of CTCs. The basic biological concept of how metastasis occurs and the role of CTCs in this process are presented. Some methods of CTC detection employing antibodies or peptides are mentioned here for comparison. The review of present literature suggests that aptamers are emerging as competitive technology in the detection of CTCs, especially due to their unique properties, but there still remain several challenges to be met, including the need to improve the throughput and sensitivity of such methods.

Phosphoinositide 3-kinase/protein kinase B/periostin mediated platelet-derived growth factor-induced cell proliferation and extracellular matrix production in lupus nephritis

In the present study, the effect and mechanism of periostin on renal proliferation and extracellular matrix accumulation of lupus mice were investigated. MRL /lpr mice, known as lupus mice, were revealed to show enhanced periostin, proliferating cell nuclear antigen (PCNA), and extracellular matrix accumulation in the kidney accompanied by increased serum platelet-derived growth factor (PDGF). Again, cultured mouse mesangial cells (MMCs) were treated with PDGF, then periostin, and PCNA and secreted fibronectin were detected. The results showed that intracellular periostin and PCNA were respectively enhanced by 2.691 and 2.308 times in PDGF-treated MMC cells at 6 h after stimulation. In addition, secreted fibronectin was increased by 1.442 times. Next, the transfection of periostin shRNA vector in PDGF-stimulated MMC cells effectively suppressed periostin, PCNA and secreted fibronectin by 45.27%, 47.75%, and 39.95%, compared with PDGF-stimulated cells transfected with control vector. Furthermore, it was found that PDGF increased the expression of phospho-Akt (Ser 473) from 30 min to 6 h in MMCs. LY294002 effectively inhibited phospho-Akt (Ser 473) expression caused by PDGF stimulation. Then, periostin, PCNA, and fibronectin were respectively decreased by 69.61%, 46.00%, and 46.20%. In the end, phosphoinositide 3-kinase/protein kinase B/periostin was suggested to mediate PDGF-induced cell proliferation and extracellular matrix production in lupus nephritis.

Periostin expression in cancer-associated fibroblasts of invasive ductal breast carcinoma

Periostin (POSTN) is a secreted cell adhesion glycoprotein that plays an important role in proliferation, adhesion and migration processes, as well as in regulation of mechanisms related to epithelial-mesenchymal transition (EMT). It also plays a key role in angio- and lymphangiogenesis and in formation of distant metastases. The aim of this work was to determine expression of POSTN in invasive ductal breast carcinoma (IDC) and in non-invasive ductal carcinoma in situ (DCIS) and to correlate its expression with clinicopathological parameters. Material for immunohistochemical studies (IHC) comprise of 70 IDC cases, 44 DCIS cases and 21 cases of fibrocystic change (FC). Frozen (-80˚C) fragments of tumours taken from 41 patients with IDC were used for molecular studies (real-time PCR), including 11 cases of IDC subjected to laser capture microdissection (LCM). POSTN expression was shown mainly in tumour stromal cells, i.e. cancer-associated fibroblasts (CAFs). Statistically significant higher level of POSTN expression in CAFs in IDC as compared to FC (p<0.0001) was observed. Additionally, statistically elevated expression level of POSTN in CAFs in IDC relative to DCIS (p<0.0001) and significantly increased expression of POSTN in CAFs in DCIS in comparison to FC (p=0.0158) was also shown. High level of POSTN expression in CAFs in IDC (>8 IRS points) was significantly correlated with tumour malignancy grade (G) (p=0.0070). Moreover, higher POSTN expression by CAFs was associated with patient shorter overall survival. Significant increase of POSTN expression on mRNA and protein level in CAFs in IDC with the growing malignancy grade of the tumours (G) was shown. Furthermore, with the use of LCM method, statistically significant higher expression of mRNA POSTN in stromal cells relative to cancer cells (p<0.001) was noted. POSTN might be a factor playing an important role in the mechanism of IDC progression.

Stromal Fibrosis and Expression of Matricellular Proteins Correlate With Histological Grade of Intraductal Papillary Mucinous Neoplasm of the Pancreas

OBJECTIVE

The aim of the study was to clarify the correlation between the microenvironmental factors and histological grade in intraductal papillary mucinous neoplasm (IPMN).

METHODS

We investigated 65 IPMNs resected at Yamagata University Hospital between 2000 and 2011, and all cases were categorized to low-inter (including low- and intermediate-grade dysplasia) and high-inv (including high-grade dysplasia and IPMN with an associated invasive carcinoma) groups. We compared between the 2 groups pathologically with regard to fibrosis and the expression of alpha-smooth muscle actin (α-SMA), periostin, and galectin-1 in the periductal stroma of IPMN.

RESULTS

There were 41 low-inter and 24 high-inv. The subtype was categorized as 22 main duct type (MD-IPMN) and 43 branch duct type (BD-IPMN). The degree of fibrosis and the expression of α-SMA, periostin, and galectin-1 were significantly higher in high-inv than in low-inter within BD-IPMNs. Multivariate logistic regression analysis indicated that high expression of α-SMA (odds ratio, 13.802; 95% confidence interval, 1.108-171.893; P = 0.0414) was a significant independent related factor of high-inv in BD-IPMN.

CONCLUSIONS

Stromal fibrosis and expression of α-SMA, periostin, and galectin-1 are more marked in high-inv than in low-inter within BD-IPMNs, and they could become new markers for determining the indications for surgery in BD-IPMN.

Identification of CD20, ECM, and ITGA as Biomarkers for Osteosarcoma by Integrating Transcriptome Analysis

Background

Osteosarcoma is the most frequent primary bone cancer derived from primitive mesenchymal cells. The aim of this study was to explore the molecular mechanism of the development and progression of osteosarcoma.

Material/Methods

The gene expression profiles of osteosarcoma from 17 specimens (3 normal and 14 osteosarcoma) were downloaded from the GEO database. The differentially expressed genes were identified by use of the Limma package. DAVID and Enrichment Map were used to perform GO and KEGG pathways enrichment analysis and to integrate enrichment results of differentially expressed genes (DEGs). Protein-protein interaction network was constructed and analyzed to screen out the potential regulatory proteins using the STRING online tools.

Results

A total of 417 DEGs were screened, including 215 up-regulated and 202 down-regulated ones, accounting for 51.56% and 48.4%, respectively. In GO term, a total of 12 up-regulated expression genes were enriched in Cellular Component. The up-regulated DEGs were enriched in 6 KEGG pathways while the down-regulated expression genes were enriched in 2 KEGG pathways. The constructed PPI network was aggregated with 1006 PPI relationships and 238 nodes, accounting for 57.07% of DEGs. We found that CD20, MCM, and CCNB1 (down-regulated) in cell cycle and ECM, ITGA, RTKin (up-regulated) in focal adhesion had important roles in the progression of osteosarcoma.

Conclusions

The identified DEGs and their enriched pathways provide references for the exploration of the molecular mechanism of the development and progression of osteosarcoma. Moreover, the key genes (CD20, ECM, and ITGA) may be useful in treatment and diagnosis of osteosarcoma.

The prognostic value of stromal and epithelial periostin expression in human breast cancer: correlation with clinical pathological features and mortality outcome

Background

PN is a secreted cell adhesion protein critical for carcinogenesis. In breast cancer, it is overexpressed compared to normal breast, and a few reports suggest that it has a potential role as a prognostic marker.

Methods

Tumour samples obtained at the time of mastectomy from 200 women followed for a median time of 18.7 years (range 0.5–29.5 years) were investigated through IHC with a polyclonal anti-PN antibody using tissue microarrays. Epithelial and stromal PN expression were scored independently according to the percentage of coloured cells; the 60^th percentile of PN epithelial expression, corresponding to 1 %, and the median value of PN stromal expression, corresponding to 90 %, were used as arbitrary cut-offs. The relationships between epithelial and stromal PN expression and clinical-pathological features, tumour phenotype and the risk of mortality following surgery were analysed. Appropriate statistics, including the Fine and Gray competing risk proportional hazard regression model, were used.

Results

The expression of PN in tumour epithelial cells was significantly lower than that which was observed in stromal cells (p < 0.000). No specific association between epithelial or stromal PN expression and any of the clinical-pathological parameters analysed was found as it was observed in respect to mortality when these variables were analysed individually. However, when both variables were considered as a function of the other one, the expression of PN in the stromal cells maintained a statistically significant predictive value with respect to both all causes and cancer-specific mortality only in the presence of high epithelial expression levels. No significant differences in either all causes or BCa-specific mortality rates were shown according to epithelial expression for tumours displaying higher stromal PN expression rates. However, the trends were opposite for the higher stromal values and the patients with high epithelial expression levels denoted the group with the worst prognosis, while higher epithelial values in patients with lower stromal expression levels denoted the group with the best prognosis, suggesting that PN epithelial/stromal interactions play a crucial role in breast carcinogenesis, most likely due to functional cross-talk between the two compartments. On the basis of PN expression in both compartments, we defined 4 subgroups of patients with different mortality rates with the group of patients characterized by positive epithelial and low stromal PN expression cells showing the lowest mortality risk as opposed to the groups of patients identified by a high PN expression in both cell compartments or those identified by a low or absent PN expression in both cell compartments showing the worst mortality rates. The differences were highly statistically significant and were also retained after multiparametric analysis. Competing risk analysis demonstrated that PN expression patterns characterizing each of previous groups are specifically associated with cancer-specific mortality.

Conclusions

Although they require further validation through larger studies, our findings suggest that the patterns of expression of PN in both compartments can allow for the development of IHC “signatures” that maintain a strong independent predictive value of both all causes and, namely, of cancer-specific mortality.

The extracellular matrix in breast cancer

The extracellular matrix (ECM) is increasingly recognized as an important regulator in breast cancer. ECM in breast cancer development features numerous changes in composition and organization when compared to the mammary gland under homeostasis. Matrix proteins that are induced in breast cancer include fibrillar collagens, fibronectin, specific laminins and proteoglycans as well as matricellular proteins. Growing evidence suggests that many of these induced ECM proteins play a major functional role in breast cancer progression and metastasis. A number of the induced ECM proteins have moreover been shown to be essential components of metastatic niches, promoting stem/progenitor signaling pathways and metastatic growth. ECM remodeling enzymes are also markedly increased, leading to major changes in the matrix structure and biomechanical properties. Importantly, several ECM components and ECM remodeling enzymes are specifically induced in breast cancer or during tissue regeneration while healthy tissues under homeostasis express exceedingly low levels. This may indicate that ECM and ECM-associated functions may represent promising drug targets against breast cancer, providing important specificity that could be utilized when developing therapies.

Novel highly specific anti-periostin antibodies uncover the functional importance of the fascilin 1-1 domain and highlight preferential expression of periostin in aggressive breast cancer

Periostin (POSTN), a secreted homodimeric protein that binds integrins αvβ3, αvβ5, and α6β4, was originally found to be expressed in fetal tissues and in the adult upon injury particularly bone fractures due to its role in remodelling and repair. Recently it was found to be over-expressed in human breast cancer and a variety of other tumour types including head and neck squamous cell carcinoma, where its overexpression correlates with increased tumour invasion. Progress in studying its functional role in tumour pathogenesis has been hampered by the paucity of antibodies for its specific and sensitive detection. It has proven very difficult to obtain monoclonal antibodies (mAbs) against this highly conserved protein but we report here that combining infection of mice with lactate dehydrogenase elevating virus (LDV), a B cell activating arterivirus, with conjugation of human POSTN to ovalbumin as an immunogenic carrier, enabled us to develop six mAbs recognizing both human and mouse POSTN and inhibiting its binding to αvβ3 integrin. Two of the mAbs, MPB4B1 and MPC5B4, were tested and found to inhibit POSTN-induced migration of human endothelial colony forming cells. All six mAbs recognized amino acids 136-51 (APSNEAWDNLDSDIRR) within the POSTN fascilin (FAS) 1-1 domain revealing the functional importance of this motif; this was further highlighted by the ability of aa 136-151 peptide to inhibit integrin-mediated cell migration. Immunohistochemistry using MPC5B4, indicated that breast tumour cell POSTN expression was a strong prognostic indicator, along with tumour size, lymph node, and human epidermal growth factor receptor 2 (HER2) status.

Targeting ECM Disrupts Cancer Progression

Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings, the extracellular matrix (ECM). Many ECM proteins are significantly deregulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread is summarized. In addition, we highlight the promising (pre-)clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression.

Epithelial cell-derived periostin functions as a tumor suppressor in gastric cancer through stabilizing p53 and E-cadherin proteins via the Rb/E2F1/p14ARF/Mdm2 signaling pathway

Periostin is usually considered as an oncogene in diverse human cancers, including breast, prostate, colon, esophagus, and pancreas cancers, whereas it acts as a tumor suppressor in bladder cancer. In gastric cancer, it has been demonstrated that periglandular periostin expression is decreased whereas stromal periostin expression is significantly increased as compared with normal gastric tissues. Moreover, periostin produced by stromal myofibroblasts markedly promotes gastric cancer cell growth. These observations suggest that periostin derived from different types of cells may play distinct biological roles in gastric tumorigenesis. The aim of this study was to explore the biological functions and related molecular mechanisms of epithelial cell-derived periostin in gastric cancer. Our data showed that periglandular periostin was significantly down-regulated in gastric cancer tissues as compared with matched normal gastric mucosa. In addition, its expression in metastatic lymph nodes was significantly lower than that in their primary cancer tissues. Our data also demonstrated that periglandular periostin expression was negatively associated with tumor stage. More importantly, restoration of periostin expression in gastric cancer cells dramatically suppressed cell growth and invasiveness. Elucidation of the mechanisms involved revealed that periostin restoration enhanced Rb phosphorylation and sequentially activated the transcription of E2F1 target gene p14(ARF), leading to Mdm2 inactivation and the stabilization of p53 and E-cadherin proteins. Strikingly, these effects of periostin were abolished upon Rb deletion. Collectively, we have for the first time demonstrated that epithelial cell-derived periostin exerts tumor-suppressor activities in gastric cancer through stabilizing p53 and E-cadherin proteins via the Rb/E2F1/p14(ARF)/Mdm2 signaling pathway.

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.

Imaging of Secreted Extracellular Periostin, an Important Marker of Invasion in the Tumor Microenvironment in Esophageal Cancer

Periostin, an extracellular matrix protein, plays key role in cell adhesion and motility within the tumor microenvironment and is correlated with tumor invasion. We developed and characterized a PET tracer that specifically targets periostin and evaluated the probe in preclinical models of esophageal squamous cell carcinoma (ESCC).

METHODS

The Institutional Animal Care and Use Committee approved all animal studies. Antiperiostin-F(ab')2 was generated from a monoclonal antibody by enzymatic digestion, conjugated to DOTA, and labeled with (64)Cu. Human ESCC cell lines, TE-11 with high and TT with minimal periostin expression, were implanted in nu/nu mice to generate the positive and control tumor models, respectively. PET/CT imaging was performed at 6, 12, and 24 h and organ-specific biodistribution at 24 h after probe injection. Additionally the probe was tested in a genetically engineered mouse model of periostin-expressing distal esophageal/forestomach ESCC. Tissue microarrays of esophageal neoplasms and ESCC as well as extracted tumor samples were stained for periostin.

RESULTS

We generated a (64)Cu-DOTA-anti-periostin-F(ab')2 with a dissociation constant of 29.2 ± 3.0 nM. PET/CT images and biodistribution studies showed significantly higher tracer uptake in TE-11 than TT tumors (maximum standardized uptake value, 24 h: 0.67 ± 0.09 vs. 0.36 ± 0.03, P < 0.0005; percentage injected dose per gram, 24 h: 3.24 ± 0.65 vs. 1.63 ± 0.49, P < 0.0001). In genetically engineered mouse models, ESCC high periostin tracer uptake anatomically correlated with the (18)F-FDG uptake at the gastroesophageal junction. All of the ESCC cores and 96.2% of adenocarcinoma stained positive for periostin, with most stained strongly (67.3% and 69.3%, respectively).

CONCLUSION

We demonstrated that specific imaging of extracellular matrix periostin in ESCC is feasible using a targeted PET tracer. Detection of periostin in the tumor microenvironment may help with early detection, postsurgical follow-up, and in situ characterization of primary and metastatic lesions.

Loss of periostin/OSF-2 in ErbB2/Neu-driven tumors results in androgen receptor-positive molecular apocrine-like tumors with reduced Notch1 activity

INTRODUCTION

Periostin (Postn) is a secreted cell adhesion protein that activates signaling pathways to promote cancer cell survival, angiogenesis, invasion, and metastasis. Interestingly, Postn is frequently overexpressed in numerous human cancers, including breast, lung, colon, pancreatic, and ovarian cancer.

METHODS

Using transgenic mice expressing the Neu oncogene in the mammary epithelium crossed into Postn-deficient animals, we have assessed the effect of Postn gene deletion on Neu-driven mammary tumorigenesis.

RESULTS

Although Postn is exclusively expressed in the stromal fibroblasts of the mammary gland, Postn deletion does not affect mammary gland outgrowth during development or pregnancy. Furthermore, we find that loss of Postn in the mammary epithelium does not alter breast tumor initiation or growth in mouse mammary tumor virus (MMTV)-Neu expressing mice but results in an apocrine-like tumor phenotype. Surprisingly, we find that tumors derived from Postn-null animals express low levels of Notch protein and Hey1 mRNA but increased expression of androgen receptor (AR) and AR target genes. We show that tumor cells derived from wild-type animals do not proliferate when transplanted in a Postn-null environment but that this growth defect is rescued by the overexpression of active Notch or the AR target gene prolactin-induced protein (PIP/GCDFP-15).

CONCLUSIONS

Together our data suggest that loss of Postn in an ErbB2/Neu/HER2 overexpression model results in apocrine-like tumors that activate an AR-dependent pathway. This may have important implications for the treatment of breast cancers involving the therapeutic targeting of periostin or Notch signaling.

Periostin is a novel therapeutic target that predicts and regulates glioma malignancy

BACKGROUND

Periostin is a secreted matricellular protein critical for epithelial-mesenchymal transition and carcinoma metastasis. In glioblastoma, it is highly upregulated compared with normal brain, and existing reports indicate potential prognostic and functional importance in glioma. However, the clinical implications of periostin expression and function related to its therapeutic potential have not been fully explored.

METHODS

Periostin expression levels and patterns were examined in human glioma cells and tissues by quantitative real-time PCR and immunohistochemistry and correlated with glioma grade, type, recurrence, and survival. Functional assays determined the impact of altering periostin expression and function on cell invasion, migration, adhesion, and glioma stem cell activity and tumorigenicity. The prognostic and functional relevance of periostin and its associated genes were analyzed using the TCGA and REMBRANDT databases and paired recurrent glioma samples.

RESULTS

Periostin expression levels correlated directly with tumor grade and recurrence, and inversely with survival, in all grades of adult human glioma. Stromal deposition of periostin was detected only in grade IV gliomas. Secreted periostin promoted glioma cell invasion and adhesion, and periostin knockdown markedly impaired survival of xenografted glioma stem cells. Interactions with αvβ3 and αvβ5 integrins promoted adhesion and migration, and periostin abrogated cytotoxicity of the αvβ3/β5 specific inhibitor cilengitide. Periostin-associated gene signatures, predominated by matrix and secreted proteins, corresponded to patient prognosis and functional motifs related to increased malignancy.

CONCLUSION

Periostin is a robust marker of glioma malignancy and potential tumor recurrence. Abrogation of glioma stem cell tumorigenicity after periostin inhibition provides support for exploring the therapeutic impact of targeting periostin.

The expression and immunohistochemical localization of periostin in odontogenic tumors of mixed epithelial/mesenchymal origin

OBJECTIVE

The object of this study was to determine the expression and localization of periostin in the major mixed odontogenic tumors and to correlate any differential staining of the mesenchymal components to the interrelationship of these tumors.

STUDY DESIGN

Five ameloblastic fibromas, 8 ameloblastic fibro-odontomas and 10 odontomas were assessed immunohistochemically for periostin staining. Because mesenchymal tissues were consistently present in all studied cases, these tissues were selected for statistical analysis of differential periostin staining.

RESULTS

Periostin was variably localized to the mesenchymal component of the tumors as well as to preameloblasts and ameloblasts. Analysis of the mesenchymal staining intensity was statistically significantly different between ameloblastic fibro-odontomas and odontomas (P < .001; Dunn multiple comparisons test).

CONCLUSIONS

Our results document periostin staining in human mixed odontogenic tumors. Statistical analysis of differential stromal staining supports the concept that the ameloblastic fibroma is a histogenetically distinct neoplasm as compared to ameloblastic fibro-odontoma and odontoma.

Overexpression of periostin predicts poor prognosis in non-small cell lung cancer

The periostin protein, encoded by the POSTN gene, is a component of the extracellular matrix, which is expressed by fibroblasts and has been observed in a variety of human malignancies. The present study aimed to detect the expression of periostin in the tissues of non-small cell lung cancer (NSCLC) patients and benign lung tumors, and to correlate the results with the clinicopathological data of the subjects, in order to evaluate periostin as a potential prognostic marker. In total, 49 NSCLC patients and 6 benign lung tumors were included in this study. The protein level of periostin was detected in paired normal/paratumor/cancer tissues by a western blot analysis and the mRNA level in paired normal/cancer tissues was detected by quantitative polymerase chain reaction (qPCR). The results were then correlated with established biological and prognostic factors. Immunohistochemistry was used to confirm the location of periostin in the NSCLC tissues. Uni- and multivariate analyses were performed using Cox's proportional hazards regression model. The protein level of periostin was elevated in the cancer tissue of the NSCLC patients compared with the normal (P=0.017) and paratumor (P=0.000) tissues. The expression level in the male patients was much higher than in the female patients at the protein (P=0.001) and mRNA (P=0.010) levels. The mRNA level in the non-adenocarcinoma (non-ADC) patients was much higher than in the adenocarcinoma (ADC) patients (P=0.029). Periostin was demonstrated higher expression at the protein level in the pseudotumors and tuberculosis patients than in the adjacent (P=0.016) and surrounding tissues (P=0.001). Immunostaining indicated that high levels of periostin were present in the mesenchymal areas, but not in the cancer cells themselves. The patients with tumors exhibiting high-level periostin expression showed a significantly shorter survival time (P=0.036, log-rank test). The 3-year survival rate was 81.5% for patients with low-level periostin expression (periostin-L; n=27) and 45.4% for patients with high-level periostin expression (periostin-H; n=22). Similarly, pathological node (pN) status was a significant prognostic marker in the univariate Cox survival analysis. Notably, periostin-H expression was also identified as an independent prognostic factor by the multivariate analysis (P=0.011). These results showed that the overexpression of periostin predicts a poor prognosis, therefore it may be regarded as a novel molecule in the progression and development of NSCLC. The results provide an additional target for the adjuvant treatment of NSCLC.

Periostin cooperates with mutant p53 to mediate invasion through the induction of STAT1 signaling in the esophageal tumor microenvironment

Periostin (POSTN), a matricellular protein, has been reported to be important in supporting tumor cell dissemination. However, the molecular mechanisms underlying POSTN function within the tumor microenvironment are poorly understood. In this study, we observe that the inducible knockdown of POSTN decreases esophageal squamous cell carcinoma (ESCC) tumor growth in vivo and demonstrate that POSTN cooperates with a conformational missense p53 mutation to enhance invasion. Pathway analyses reveal that invasive esophageal cells expressing POSTN and p53(R175H) mutation display activation of signal transducer and activator of transcription 1 (STAT1) target genes, suggesting that the induction of STAT1 and STAT1-related genes could foster a permissive microenvironment that facilitates invasion of esophageal epithelial cells into the extracellular matrix. Genetic knockdown of STAT1 in transformed esophageal epithelial cells underscores the importance of STAT1 in promoting invasion. Furthermore, we find that STAT1 is activated in ESCC xenograft tumors, but this activation is attenuated with inducible knockdown of POSTN in ESCC tumors. Overall, these results highlight the novel molecular mechanisms supporting the capacity of POSTN in mediating tumor invasion during ESCC development and have implications of therapeutic strategies targeting the tumor microenvironment.

Clear cell renal cell carcinoma induces fibroblast-mediated production of stromal periostin

OBJECTIVES

Increase in periostin (PN) was reported in clear cell renal cell carcinoma (ccRCC). But how PN contributes to ccRCC pathogenesis remains unclear. This research will investigate the underlying mechanism.

METHODS

The PN protein in 37 adjacent non-tumour kidney (ANK) tissues, their respective ccRCCs, 16 cases of metastasised ccRCC and xenograft tumours was analysed by immunohistochemistry. PN expression in ccRCC cells and NIH3T3 fibroblasts was examined by real time PCR (polymerase chain reaction) and western blot.

RESULTS

PN was detected at low levels in the tubular epithelial cells of ANKs. PN was robustly increased in the ccRCC-associated stroma of both organ-confined and metastasised ccRCCs. Furthermore, despite A498 ccRCC cells and their-derived xenograft tumour cells expressing a low level of PN, a strong presence of stromal PN was observed especially in the boundary region between xenograft tumour mass and non-tumour tissue. Collectively, these results suggest that the ccRCC-associated PN was derived from stroma instead of tumours. This notion was supported by the co-existence of PN with α-smooth muscle actin (αSMA), a marker of activated fibroblasts, in both local and metastasised ccRCC. Furthermore, co-culture of NIH3T3 mouse fibroblasts with either human A498 or 786-0 ccRCC cells dramatically enhanced PN transcription only in NIH3T3 cells as well as NIH3T3 cell-mediated accumulation of extracellular PN. In return, extracellular PN significantly enhanced A498 cell attachment. Elevation of PN promotes NIH3T3 cell proliferation and enhanced AKT activation.

CONCLUSIONS

ccRCC induces fibroblast-mediated accumulation of stromal PN; stromal PN enhances ccRCC cell attachment and fibroblast proliferation.

Periostin-binding DNA aptamer inhibits breast cancer growth and metastasis

Periostin is an extracellular matrix (ECM) protein that is overexpressed in a variety of human cancers, and its functions appear to be linked to tumor growth, metastasis, and angiogenesis. Recent clinical evidence suggests that aberrant periostin expression is correlated with poor outcome in patients with breast cancer. To identify novel tools to regulate the functional role of periostin, we generated benzyl-d(U)TP-modified DNA aptamers that were directed against human periostin (PNDAs) and characterized their functional roles in breast cancer progression. PNDA-3 selectively bound to the FAS-1 domain of periostin with nanomolar affinity and disrupted the interaction between periostin and its cell surface receptors, αvβ3 and αvβ5 integrins. PNDA-3 markedly antagonized the periostin-induced adhesion, migration, and invasion of breast cancer cells and blocked the activation of various components of the αvβ3 and αvβ5 integrin signal transduction pathways. In a 4T1 orthotopic mouse model, PNDA-3 administration significantly reduced primary tumor growth and distant metastasis. Thus, our results demonstrated that periostin-integrin signaling regulates breast cancer progression at multiple levels in tumor cells and the tumor microenvironment. DNA aptamers targeting periostin may potentially be used to inhibit breast cancer progression.

Periostin is a systemic biomarker of eosinophilic airway inflammation in asthmatic patients

BACKGROUND

Eosinophilic airway inflammation is heterogeneous in asthmatic patients. We recently described a distinct subtype of asthma defined by the expression of genes inducible by T(H)2 cytokines in bronchial epithelium. This gene signature, which includes periostin, is present in approximately half of asthmatic patients and correlates with eosinophilic airway inflammation. However, identification of this subtype depends on invasive airway sampling, and hence noninvasive biomarkers of this phenotype are desirable.

OBJECTIVE

We sought to identify systemic biomarkers of eosinophilic airway inflammation in asthmatic patients.

METHODS

We measured fraction of exhaled nitric oxide (Feno), peripheral blood eosinophil, periostin, YKL-40, and IgE levels and compared these biomarkers with airway eosinophilia in asthmatic patients.

RESULTS

We collected sputum, performed bronchoscopy, and matched peripheral blood samples from 67 asthmatic patients who remained symptomatic despite maximal inhaled corticosteroid treatment (mean FEV(1), 60% of predicted value; mean Asthma Control Questionnaire [ACQ] score, 2.7). Serum periostin levels are significantly increased in asthmatic patients with evidence of eosinophilic airway inflammation relative to those with minimal eosinophilic airway inflammation. A logistic regression model, including sex, age, body mass index, IgE levels, blood eosinophil numbers, Feno levels, and serum periostin levels, in 59 patients with severe asthma showed that, of these indices, the serum periostin level was the single best predictor of airway eosinophilia (P = .007).

CONCLUSION

Periostin is a systemic biomarker of airway eosinophilia in asthmatic patients and has potential utility in patient selection for emerging asthma therapeutics targeting T(H)2 inflammation.

Periostin activates integrin α5β1 through a PI3K/AKT‑dependent pathway in invasion of cholangiocarcinoma

Periostin (PN) is mainly produced from stromal fibroblasts in cholangiocarcinoma (CCA) and shows strong impact in cancer promotion. This work aimed to investigate the mechanism that PN uses to drive CCA invasion. It was found that ITGα5β1 and α6β4 showed high expression in non-tumorigenic biliary epithelial cells and in almost all CCA cell lines. PN had preferential binding to CCA cells via ITGα5β1 and blocking this receptor by either neutralizing antibody or siITGα5 could attenuate PN-induced invasion. After PN-ITGα5β1 binding, intracellular pAKT was upregulated whereas there was no change in pERK. Moreover, PN could not activate AKT in condition of treatment with a PI3K inhibitor. These data provide evidence that PN-activated invasion of CCA cells is through the ITGα5β1/PI3K/AKT pathway. Strategies aimed to inhibit this pathway may, thus, provide therapeutic benefits.

Periostin, a stroma-associated protein, correlates with tumor invasiveness and progression in nasopharyngeal carcinoma

Recently, the tumor microenvironment is increasingly recognized as playing an important role in cancer proliferation, invasion, and metastasis. To screen stroma-associated proteins involved in nasopharyngeal carcinoma (NPC) carcinogenesis, laser capture microdissection (LCM) and quantitative proteomic analysis were employed to assess different protein expression of the stroma between NPC and normal nasopharyngeal mucosa (NNM). In this study, periostin was identified to be significantly up-regulated in NPC stroma compared with NNM stroma and the result was further confirmed by Western blotting. Immunohistochemistry showed that over-expression of periostin was frequently observed in the stroma of NPC and matched lymph node metastases (LNM) compared with the stroma of NNM. Statistical analysis showed over-expression of periostin was significantly associated with advanced clinical stage (P < 0.001) and lymph node metastasis (P < 0.001) and decreased overall survival (P < 0.001) in NPC. Cox regression analysis indicated over-expression of periostin was an independent prognostic factor. Furthermore, ectopic expression of periostin was used to examine its effect on invasiveness of NPC cell in vitro and the result showed that periostin was able to promote invasiveness of NPC cell. In conclusion, periostin expression is correlated with tumor stage, lymph node metastasis, and patient survival. Periostin is a potential biomarker for the differentiation and prognosis of NPC, and it might play an important role in the progression of NPC.