Utility of progranulin and serum leukocyte protease inhibitor as diagnostic and prognostic biomarkers in ovarian cancer

Progranulin Oncogenic Network in Solid Tumors

Progranulin is a pleiotropic growth factor with important physiological roles in embryogenesis and maintenance of adult tissue homeostasis. While-progranulin deficiency is associated with a broad range of pathological conditions affecting the brain, such as frontotemporal dementia and neuronal ceroid lipofuscinosis, progranulin upregulation characterizes many tumors, including brain tumors, multiple myeloma, leiomyosarcoma, mesothelioma and epithelial cancers such as ovarian, liver, breast, bladder, adrenal, prostate and kidney carcinomas. The increase of progranulin levels in tumors might have diagnostic and prognostic significance. In cancer, progranulin has a pro-tumorigenic role by promoting cancer cell proliferation, migration, invasiveness, anchorage-independent growth and resistance to chemotherapy. In addition, progranulin regulates the tumor microenvironment, affects the function of cancer-associated fibroblasts, and modulates tumor immune surveillance. However, the molecular mechanisms of progranulin oncogenic function are not fully elucidated. In bladder cancer, progranulin action relies on the activation of its functional signaling receptor EphA2. Notably, more recent data suggest that progranulin can also modulate a functional crosstalk between multiple receptor-tyrosine kinases, demonstrating a more complex and context-dependent role of progranulin in cancer. Here, we will review what is currently known about the function of progranulin in tumors, with a focus on its molecular mechanisms of action and regulation.

Can serum progranulin level be used as a prognostic biomarker in non-small cell lung cancer?

Progranulin has been considered to be a poor prognostic biomarker for some types of malignancies. However, the clinical significance of serum progranulin level and the prognostic value are still not explored in advanced stages of lung cancer.  The current study investigates the prognostic significance of progranulin serum levels in advanced-stage non-small cell lung cancer (NSCLC) patients. This study involved 94 subjects (70 advanced-stage NSCLC patients and 24 healthy controls). Serum progranulin level was measured by enzyme-linked immunosorbent assay (ELISA) and was correlated with patient outcome. The association between circulating progranulin level and clinicopathological parameters was detected. Serum progranulin cut-off level predicting six-month survival was determined. Serum progranulin level was found significantly elevated in NSCLC patients than in the control group (p<0.001). We did not determine a significant difference between stage IIIB and stage IV NSCLC patients for serum progranulin levels (p=0.166). When we evaluated the laboratory parameters, only serum LDH level was found significantly correlated with serum progranulin level (p=0.043), also bone and liver metastasis showed a significant correlation with progranulin level (p=0.008 and p = 0.024, respectively). The cut-off level of serum progranulin in predicting six months of survival was determined as 16.03 ng/ml (AUC = 0.973, 95%Cl: 0.903-0.997, p<0.001) with 97.06% sensitivity and 88.89% specificity. Overall survival was determined shorter in patients with progranulin level ≥16 ng/ml than those with <16 ng/ml (p<0.001). Also, in the multivariate analysis using the Cox regression model serum progranulin level was found as an independent prognostic factor for NSCLC (p=0.001). Serum progranulin level may be a useful biomarker for predicting poor survival in advanced-stage NSCLC patients.

Roles of Antimicrobial Peptides in Gynecological Cancers

Antimicrobial peptides (AMPs) are essential components of the mucosal barrier of the female reproductive tract (FRT) and are involved in many important physiological processes, including shaping the microbiota and maintaining normal reproduction and pregnancy. Gynecological cancers seriously threaten women's health and bring a heavy burden to society so that new strategies are needed to deal with these diseases. Recent studies have suggested that AMPs also have a complex yet intriguing relationship with gynecological cancers. The expression level of AMPs changes during tumor progression and they may act as promising biomarkers in cancer detection and prognosis prediction. Although AMPs have long been considered as host protective, they actually play a "double-edged sword" role in gynecological cancers, either tumorigenic or antitumor, depending on factors such as AMP and cancer types, as well as AMP concentrations. Moreover, AMPs are associated with chemoresistance and regulation of AMPs' expression may alter sensitivity of cancer cells to chemotherapy. However, more work is needed, especially on the identification of molecular mechanisms of AMPs in the FRT, as well as the clinical application of these AMPs in detection, diagnosis and treatment of gynecological malignancies.

A narrative review of multiple mechanisms of progranulin in cancer: a potential target for anti-cancer therapy

Progranulin (PGRN) is an autocrine growth factor and has important effects on regulation of cell growth, motility, tissue repair and embryonic development. Recent years, several researches found the expression of PGRN was at higher levels in a number of cancer cells and its high levels are associated with poor outcome of patients. More and more studies investigated the role of PGRN in cancer and found PGRN exerted various biological functions in cancer cells, such as promoting proliferation, inhibiting apoptosis, inducing migration and invasion of cells, accelerating angiogenesis and enhancing the effectiveness of chemoresistance and radiation. Now the effects of PGRN have been demonstrated in several cancers, including breast cancer, lung cancer, and bladder cancer. In addition, several signaling pathways and molecules are involved in the effects of PGRN on cancer cells, including Akt, mitogen-activated protein kinase (MAPK), vascular endothelial growth factor (VEGF) and cyclin D1. Therefore, PGRN is probably a significant diagnostic and prognostic biomarker for cancer and may be a potential target for anti-cancer therapy. Here, we reviewed the advancing field of PGRN in cancer as well as several signaling pathways activated by PGRN and confirmed PGRN is a key role in cancer. Moreover, future studies are still necessary to elucidate the biological functions and signaling pathways of PGRN in cancer.

Serum GP88 as a predictive biomarker for hepatocellular carcinoma in patients with viral hepatitis C after direct-acting antiviral agents

BACKGROUND

Progranulin (GP88) is an 88-kDa glycoprotein growth factor with important biological effects in tumorigenesis and tumour survival. We investigated the usefulness of measuring serum GP88 concentrations as a predictive biomarker for hepatocellular carcinoma in patients with viral hepatitis C after treatment with direct-acting antiviral agents.

METHODS

We measured the serum GP88 concentrations by using a sandwich enzyme-linked immunoassay from 67 healthy control subjects and 29 patients (20 patients who did not develop hepatocellular carcinoma and 9 patients who developed hepatocellular carcinoma after treatment) with viral hepatitis C after treatment with asunaprevir and daclatasvir.

RESULTS

The serum GP88 concentrations of patients with chronic hepatitis C prior to antiviral treatment were significantly higher than those of healthy control subjects. After antiviral treatment, the serum GP88 concentrations of patients who eventually developed hepatocellular carcinoma were significantly higher than those who did not develop hepatocellular carcinoma. The changes in the serum GP88 concentrations before and after treatment in patients who developed hepatocellular carcinoma were significantly lower than those in patients who did not develop hepatocellular carcinoma. The cumulative incidence of hepatocellular carcinoma was significantly higher in either patients with high serum GP88 concentrations after treatment or those with small changes of serum GP88 concentrations pre- and post-treatment.

CONCLUSIONS

Sustained high concentrations of serum GP88 in patients treated with direct-acting antiviral agents are correlated with the risk of developing hepatocellular carcinoma.

WFDC Protein: A Promising Diagnosis Biomarker of Ovarian Cancer

An initial diagnosis of cancer is usually based on symptoms, abnormal physical examination and imaging tests. Ovarian cancer is difficult to be diagnosed timely due to the nonspecific symptoms, thus resulting in the high-risk mortality. Despite of the various diagnostic methods, there is still no reliable diagnostic test. Clinically, carbohydrate antigen 125(CA125) is widely recognized as a diagnosis biomarker of ovary cancer. However, CA125 is not sensitive to detect the ovary cancer at the early stage. It is essential to explore other potential biomarkers. Human epididymis protein 4 (HE4) in the whey/four-disulfide core (WFDC) proteins family shows satisfactory sensitivity in the early diagnosis of ovary cancer. In this present review, we summarized the important effects of WFDC family proteins on the proliferation, apoptosis and migration of ovary cancer and intended to provide more evidence to explore the possibility of WFDC protein as a diagnosis biomarker.

PGRN exacerbates the progression of non-small cell lung cancer via PI3K/AKT/Bcl-2 antiapoptotic signaling

Progranulin (PGRN) is a growth factor that is involved in the progression of multiple tumors. However, the effects and molecular mechanisms by which PGRN induces lung cancer remain unclear. The expression level of PGRN was analyzed by conducting immunohistochemistry of the histological sections of lung tissues from non-small-cell lung carcinoma (NSCLC) patients. The proliferation, apoptosis, migration, and invasion of NSCLC cells were assessed by the MTT assay, Western blot, degree of wound healing, and Transwell assays. A nude mouse xenograft model was used to validate the role of PGRN in vivo. The expression level of PGRN was higher in male patients with lung adenocarcinoma than in those with lung squamous cell carcinoma; by contrast, no difference was observed in female patients. The overexpression of PGRN promoted the proliferation and anti-apoptosis of H520 (derived from lung squamous cell carcinoma) cells, whereas knockdown of PGRN inhibited the proliferation and anti-apoptosis of A549 (derived from lung adenocarcinoma) cells. Copanlisib (targeting PI3K) inhibited the increase in the expression of cell anti-apoptosis marker Bcl-2 induced by rhPGRN protein; the PI3K agonist 740 Y–P partially reversed the decrease in Bcl-2 expression induced by PGRN deficiency in both A549 and H520 cells. PGRN increased the expression of Ki-67, PCNA, and Bcl-2 in vivo. PGRN inhibited cell apoptosis depending on the PI3K/Akt/Bcl-2 signaling axis; PGRN positivity correlated with lung adenocarcinoma. PGRN is a potential biomarker for the treatment and diagnosis of NSCLC, especially in lung adenocarcinoma.

GP88/PGRN Serum Levels Are Associated with Prognosis for Oral Squamous Cell Carcinoma Patients

Simple Summary

An oral squamous cell carcinoma (OSCC) is a tumor of the oral cavity that has a five-year survival rate of only around 50%. As this rate has not increased in recent decades, despite improvements in diagnosis and therapy, novel, easily accessible biomarkers for prognosis assessment are still needed. In our study, we measured the growth factor protein progranulin/GP88 in the serum of OSCC patients and demonstrated that an increased serum GP88 level is associated with a better prognosis for the OSCC patients in our study group. Furthermore, serum GP88 levels were not significantly associated with age, sex, or the tumor’s histological features, indicating that serum GP88 levels may be an independent predictor of an individual OSCC patient’s prognosis. These findings may help to improve therapy management of an OSCC in personalized medicine.

Abstract

Progranulin (PGRN)/GP88 is a growth factor that is expressed in a wide range of tumor tissues. The secreted form is involved in various biological processes including proliferation and inflammation. In several tumor types, the serum GP88 level is associated with a patient’s prognosis; however, data for oral squamous cell carcinomas (OSCCs) have not yet been reported. We measured the serum GP88 levels in 96 OSCC patients by an enzyme immunosorbent assay (EIA) and correlated these data with clinicopathological parameters and patient outcomes. The GP88 levels in the serum of OSCC patients and healthy volunteers were comparable. In OSCC patients, the levels did not correlate with age, sex, or TNM status. In a Kaplan–Meier survival analysis, a serum GP88 level < 68 ng/mL was significantly associated with worsened survival (p = 0.0005, log-rank-test) as well as in uni- and multivariate Cox regression analyses (RR = 4.6 [1.6–12.9], p = 0.004 and RR = 4.2 [1.2–12.0], p = 0.008). This effect was predominant in OSCC patients older than 60.5 years (p = 0.027), while in younger patients no significant association between serum GP88 levels and prognosis could be observed. Altogether, lower serum GP88 levels are significantly associated with a worsened outcome for an OSCC and may be an interesting candidate for risk stratification during OSCC therapy.

Role of exosomes in the immune microenvironment of ovarian cancer

Exosomes are excretory vesicles that can deliver a variety of bioactive cargo molecules to the extracellular environment. Accumulating evidence demonstrates exosome participation in intercellular communication, immune response, inflammatory response and they even play an essential role in affecting the tumor immune microenvironment. The role of exosomes in the immune microenvironment of ovarian cancer is mainly divided into suppression and stimulation. On one hand exosomes can stimulate the innate and adaptive immune systems by activating dendritic cells (DCs), natural killer cells and T cells, allowing these immune cells exert an antitumorigenic effect. On the other hand, ovarian cancer-derived exosomes initiate cross-talk with immunosuppressive effector cells, which subsequently cause immune evasion; one of the hallmarks of cancer. Exosomes induce the polarization of macrophages in M2 phenotype and induce apoptosis of lymphocytes and DCs. Exosomes further activate additional immunosuppressive effector cells (myeloid-derived suppressor cells and regulatory T cells) that induce fibroblasts to differentiate into cancer-associated fibroblasts. Exosomes also induce the tumorigenicity of mesenchymal stem cells to exert additional immune suppression. Furthermore, besides mediating the intercellular communication, exosomes carry microRNAs (miRNAs), proteins and lipids to the tumor microenvironment, which collectively promotes ovarian cancer cells to proliferate, invade and tumors to metastasize. Studying proteins, lipids and miRNAs carried by exosomes could potentially be used as an early diagnostic marker of ovarian cancer for designing treatment strategies.

Secretory Leukocyte Protease Inhibitor (SLPI) in mucosal tissues: Protects against inflammation, but promotes cancer

The immune system is continuously challenged with large quantities of exogenous antigens at the barriers between the external environment and internal human tissues. Antimicrobial activity is essential at these sites, though the immune responses must be tightly regulated to prevent tissue destruction by inflammation. Secretory Leukocyte Protease Inhibitor (SLPI) is an evolutionarily conserved, pleiotropic protein expressed at mucosal surfaces, mainly by epithelial cells. SLPI inhibits proteases, exerts antimicrobial activity and inhibits nuclear factor-kappa B (NF-κB)-mediated inflammatory gene transcription. SLPI maintains homeostasis at barrier tissues by preventing tissue destruction and regulating the threshold of inflammatory immune responses, while protecting the host from infection. However, excessive expression of SLPI in cancer cells may have detrimental consequences, as recent studies demonstrate that overexpression of SLPI increases the metastatic potential of epithelial tumors. Here, we review the varied functions of SLPI in the respiratory tract, skin, gastrointestinal tract and genitourinary tract, and then discuss the mechanisms by which SLPI may contribute to cancer.

The interaction of smoking habit, SLPI and AnxA2 in HPV associated head and neck and other cancers

Six own studies confirm a correlation between smoking, expression of the secretory leukocyte protease inhibitor (SLPI, an antileukoproteinase) and expression of Annexin A2 (AnxA2), and their influence on human papilloma virus (HPV)-infections. SLPI and HPV are ligands of AnxA2. This correlation was tested on 928 tissue samples from 892 patients in six independent studies [squamous cell carcinoma of the head and neck (HNSCC), n = 522; non-neoplastic tonsils n = 214; clinically normal mucosa, n = 93 (of these n = 57 were obtained from patients treated for non-malignant diseases and n = 36 were obtained from HNSCC-patients) and vulvar squamous cell carcinoma (VSCC) n = 99]. HPV-DNA-status was determined by GP5+/GP6+-PCR, followed in case of HPV-positivity by Sanger sequencing and RT-PCR using HPV-type specific primers. SLPI- and AnxA2-gene-expression was determined by RT-q-PCR; SLPI-protein-expression was additionally determined by immunohistochemistry (IHC); the data were correlated with each other and with patient characteristics. Smoking results in increased SLPI-gene- and protein- and AnxA2-gene-expression with significantly higher SLPI- than AnxA2-gene-expression. SLPI is decreased in non-smokers with a continuous AnxA2-surplus. HPV-status correlates with smoking habit, with smokers being mostly HPV-negative and non-smokers HPV-positive. We hypothesize that smoking leads to SLPI-overexpression with SLPI-binding to AnxA2. Thus, HPV cannot bind to AnxA2 but this seems pivotal for HPV-cell-entry. Smoking favors SLPI-expression resulting in HPV-negative carcinomas, while HPV-positive carcinomas are more common in non-smokers possibly due to a surplus of unbound AnxA2. In addition, the hypothesis may contribute to understand why smokers show increased oral HPV-prevalence in natural history studies but do not necessarily develop HPV-associated lesions.

A GRN Autocrine-Dependent FAM135B/AKT/mTOR Feedforward Loop Promotes Esophageal Squamous Cell Carcinoma Progression

Esophageal squamous cell carcinoma (ESCC) is one of the most common and deadly diseases. In our previous comprehensive genomics study, we found that family with sequence similarity 135 member B (FAM135B) was a novel cancer-related gene, yet its biological functions and molecular mechanisms remain unclear. In this study, we demonstrate that the protein levels of FAM135B are significantly higher in ESCC tissues than in precancerous tissues, and high expression of FAM135B correlates with poorer clinical prognosis. Ectopic expression of FAM135B promoted ESCC cell proliferation in vitro and in vivo, likely through its direct interaction with growth factor GRN, thus forming a feedforward loop with AKT/mTOR signaling. Patients with ESCC with overexpression of both FAM135B and GRN had worse prognosis; multivariate Cox model analysis indicated that high expression of both FAM135B and GRN was an independent prognostic factor for patients with ESCC. FAM135B transgenic mice bore heavier tumor burden than wild-type mice and survived a relatively shorter lifespan after 4-nitroquinoline 1-oxide treatment. In addition, serum level of GRN in transgenic mice was higher than in wild-type mice, suggesting that serum GRN levels might provide diagnostic discrimination for patients with ESCC. These findings suggest that the interaction between FAM135B and GRN plays critical roles in the regulation of ESCC progression and both FAM135B and GRN might be potential therapeutic targets and prognostic factors in ESCC. SIGNIFICANCE: These findings investigate the mechanisms of FAM135B in promoting ESCC progression and suggest new potential prognostic biomarkers and therapeutic targets in patients with ESCC.

Serum Adiponectin and Progranulin Level in Patients with Benign Thyroid Nodule or Papillary Thyroid Cancer

BACKGROUND

Obesity is associated with thyroid cancer risk. Adiponectin has insulin-sensitizing and anti-inflammatory effects, while progranulin is associated with inflammation and tumorigenesis. We investigated serum adiponectin and progranulin levels in patients with benign thyroid nodule (benign group) and papillary thyroid cancer (PTC; PTC group). The associations between these levels and the clinicopathological features of PTC were evaluated.

METHODS

We included 157 patients who underwent thyroid surgery (17% of benign and 83% of PTC group). Clinicopathological features including size, lymph node metastasis, extrathyroidal extension (ETE), multifocality, American Thyroid Association risk stratification were evaluated.

RESULTS

The age was 42.0 years, and 69% were female. Serum adiponectin and progranulin levels were 6.3 μg/mL and 101.5 ng/mL in the benign group and 5.4 μg/mL and 106.1 ng/mL in the PTC group, respectively (P=0.6 and P=0.4, respectively). Serum adiponectin levels showed no significant differences according to clinicopathological features of PTC. The proportions of patients with primary tumor size &gt;1 cm were 3%, 5%, 8%, and 8% according to serum progranulin level quartiles, respectively (P=0.03). The proportions of patients with microscopic/gross ETE were 8%/0%, 9%/1%, 11%/1%, and 11%/2% according to serum progranulin level quartiles, respectively. Median serum progranulin level was significantly higher in patients with PTC &gt;1 cm than in patients with papillary thyroid microcarcinoma (P=0.04, 115.3 ng/mL and 104.7 ng/mL, respectively).

CONCLUSION

Serum adiponectin and progranulin levels showed no significant difference between benign and PTC groups. Increased serum progranulin levels were significantly associated with PTC &gt;1 cm and microscopic and gross ETE.

Prognostic significance of serum progranulin level in de novo adult acute lymphoblastic leukemia patients

Increased expression of progranulin (PGRN) has been reported in some hematological cancers, but limited information regarding its significance in acute lymphoblastic leukemia (ALL) is available. This study involved 60 subjects (40 de novo adult ALL patients and 20 controls). Serum PGRN level was measured by enzyme-linked immunosorbent assay and was correlated with patient outcome. Serum PGRN level was significantly higher in patients than controls. Serum PGRN level did not correlate with age, total leukocytic count, hemoglobin, platelets, absolute blast count in peripheral blood, lactate dehydrogenase, percent of blasts in bone marrow, gender, comorbidities, the presence of central nervous system infiltration, ALL phenotype, cytogenetics and risk of the disease. High serum PGRN level was not associated with inferior overall survival (OS) on univariate analysis. Regarding cumulative incidence of relapse (CIR) and disease-free survival (DFS), high PGRN level was associated with poor results on univariate analysis. Moreover, it tended to be independent risk factor on multivariate analysis for CIR but was not an independent predictor of inferior DFS. Serum PGRN level is significantly elevated in de novo adult ALL patients and may be used as a predictor of increased relapse risk.

The prognostic relevance and expression of progranulin in adult patients with acute myeloid leukemia

Progranulin (PGRN) is a secreted protein that can regulate cell cycle progression, cell motility, and tumorigenesis. The PGRN expression in hematological malignancies is limited to multiple myeloma, but its expression and survival prognostic role in acute myeloid leukemia (AML) is still controversial.To evaluate the PGRN expression and estimate its survival prognostic role in AML patients.In this study, all patients were divided into three groups, which included 38 newly diagnosed adult AML patients, 33 complete remissions (CR-AML) patients, and 60 healthy control (HC) patients. The endpoints were relapse-free survival (RFS) and overall survival (OS). We investigated plasma PGRN levels by using enzyme-linked immunosorbent assay.Plasma PGRN levels in AML patients were higher than that in CR-AML and HC groups. After two chemo cycles, 16 patients had complete remission (CR). The level of plasma PGRN in non-CR patients compared to CR patients was obviously different (median 44.19 vs 21.10 ng/mL) (P = .025). In non-M3 (French-American-British classification) patients, 70% (21/30) patients relapsed in 1 year and 80% (24/80) patients died in the observed time. Using the value (median 19.95) as a "cut-off" value, we have divided non-M3 patients into low- and high-PGRN expression groups. High-PGRN expression patients had a poorer RFS with a median of 5.4 months (95% CI 3.7-7.1) and low-PGRN expression patients had a good RFS with a median of 8.9 months (95% CI 6.3-11.5; P = .027). In the survival analyses, high-PGRN expression of AML patients had shorter OS than low-PGRN expression of AML patients (6.2 vs 20.5 months, P = .008).PGRN is overexpressed in AML, which is a convenient and independent prognostic marker that is measured easily in AML patients.

Inhibition of PI3K/AKT/mTOR and MAPK signaling pathways decreases progranulin expression in ovarian clear cell carcinoma (OCCC) cell line: a potential biomarker for therapy response to signaling pathway inhibitors

Patients with advanced stage ovarian clear cell carcinoma (OCCC) have a poor prognosis due to resistance to conventional platinum chemotherapy. Recent studies have demonstrated that PI3K/AKT/mTOR and ERK1/2 signaling pathways are involved in this chemoresistance. Progranulin (PGRN) overexpression contributes to cisplatin resistance of epithelial ovarian cancer cell lines. Also, PGRN expression is regulated by AKT/mTOR and ERK1/2 signaling pathways in different cell types. Thus, the present study was designed to identify if PGRN expression is regulated by AKT, mTOR, and ERK1/2 signaling pathways in the OCCC cell line TOV-21G. Cultured TOV-21G cells were incubated with different concentrations of pharmacological cell signaling inhibitors. PGRN expression and phosphorylation of ERK1/2, AKT, and mTOR were assessed by Western blotting. Inhibition of AKT, mTOR, and ERK1/2 significantly reduced PGRN expression. Cell viability was not affected, while cell proliferation significantly decreased with all inhibitors used in this study. These observations demonstrated that inhibition of PI3K/AKT/mTOR and ERK1/2 signaling pathways reduces PGRN expression in TOV-21G cells. Thus, PGRN could be considered as a candidate for explaining the high resistance to platinum-based treatment and a potential biomarker for therapy response to cell signaling inhibitors in patients with OCCC.

Progranulin promotes melanoma progression by inhibiting natural killer cell recruitment to the tumor microenvironment

Progranulin (PGRN) is a growth factor with significant biological effects in different types of cancer. However, its role in melanoma progression has not been explored. In this study, we first analyze clinical datasets and show that high PGRN expression levels are correlated with poor prognosis of melanoma patients. Further, we demonstrate in a transplanted murine melanoma model in which the endogenous Grn gene encoding PGRN has been deleted that tumor-derived, not host-derived PGRN, promotes melanoma growth and metastasis. Immunological analyses reveal an enhanced infiltration of natural killer cells, but not T lymphocytes, into PGRN-deficient tumors compared to the wild type control. Antibody-mediated depletion confirms the critical role of NK cells in controlling B16 tumor growth. RNA-seq analysis reveals that several chemokines including CCL5 are strongly upregulated in PGRN-deficient tumor. Silencing CCL5 expression in PGRN-deficient tumor reduces NK cell recruitment and restores tumor growth to the control level. Lastly, we show that PGRN inhibits Ccl5 gene expression at the transcriptional level. This study highlights a novel and critical role of PGRN in melanoma growth and metastasis and suggests that it may represent a potential therapeutic target.

Progranulin: A conductor of receptors orchestra, a chaperone of lysosomal enzymes and a therapeutic target for multiple diseases

Progranulin (PGRN), a widely expressed glycoprotein with pleiotropic function, has been linked to a host of physiological processes and diverse pathological states. A series of contemporary preclinical disease models and clinical trials have evaluated various therapeutic strategies targeting PGRN, highlighting PGRN as a promising therapeutic target. Herein we summarize available knowledge of PGRN targeting in various kinds of diseases, including common neurological diseases, inflammatory autoimmune diseases, cancer, tissue repair, and rare lysosomal storage diseases, with a focus on the functional domain-oriented drug development strategies. In particular, we emphasize the role of extracellular PGRN as a non-conventional, extracellular matrix bound, growth factor-like conductor orchestrating multiple membrane receptors and intracellular PGRN as a chaperone/co-chaperone that mediates the folding and traffic of its various binding partners.

Granulin epithelin precursor promotes colorectal carcinogenesis by activating MARK/ERK pathway

Background

Granulin epithelin precursor (GEP) is reported to function as a growth factor stimulating proliferation and migration, and conferring chemoresistance in many cancer types. However, the expression and functional roles of GEP in colorectal cancer (CRC) remain elusive. The aim of this study was thus to investigate the clinical significance of GEP in CRC and reveal the molecular mechanism of GEP in CRC initiation and progression.

Methods

The mRNA expression of GEP in CRC cell lines were detected by qRT-PCR. The GEP protein expression was validated by immunohistochemistry in tissue microarray (TMA) including 190 CRC patient samples. The clinicopathological correlation analysis were achieved by GEP expression on TMA. Functional roles of GEP were determined by MTT proliferation, monolayer colony formation, cell invasion and migration and in vivo studies through siRNA/shRNA mediated knockdown assays. The cancer signaling pathway identification was acquired by flow cytometry, western blot and luciferase activity assays.

Results

The mRNA expression of GEP in CRC was significantly higher than it in normal colon tissues. GEP protein was predominantly localized in the cytoplasm and most of the CRC cases demonstrated abundant GEP protein compared with non-tumorous tissues. GEP overexpression was associated with non-rectal location, advanced AJCC stage, regional lymph node and distant metastasis. By Kaplan–Meier survival analysis, GEP abundance served as a prognostic marker for worse survival in CRC patients. GEP knockdown exhibited anti-cancer effect such as inhibiting cell proliferation, monolayer colony formation, cell invasion and migration in DLD-1 and HCT 116 cells and decelerating xenograft formation in nude mice. siGEP also induced G1 cell cycle arrest and apoptosis. Luciferase activity assays further demonstrated GEP activation was involved in MAPK/ERK signaling pathway.

Conclusion

In summary, we compressively delineate the oncogenic role of GEP in colorectal tumorigenesis by activating MAPK/ERK signaling pathway. GEP might serve as a useful prognostic biomarker and therapeutic target for CRC.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1530-7) contains supplementary material, which is available to authorized users.

Pinin interacts with C-terminal binding proteins for RNA alternative splicing and epithelial cell identity of human ovarian cancer cells

Unlike many other human solid tumors, ovarian tumors express many epithelial markers at a high level for cell growth and local invasion. The phosphoprotein Pinin plays a key role in epithelial cell identity. We showed that clinical ovarian tumors and ovarian cancer cell lines express a high level of Pinin when compared with normal ovarian tissues and immortalized normal ovarian surface epithelial cell lines. Pinin co-localized and physically interacted with transcriptional corepressor C-terminal binding proteins, CtBP1 and CtBP2, in the nuclei of cancer cells. Knockdown of Pinin in ovarian cancer cells resulted in specific reduction of CtBP1 protein expression, cell adhesion, anchorage-independent growth, and increased drug sensitivity. Whole transcriptomic comparison of next-generation RNA sequencing data between control ovarian cancer cell lines and cancer cell lines with respective knockdown of Pinin, CtBP1, and CtBP2 expression also showed reduced expression of CtBP1 mRNA in the Pinin knockdown cell lines. The Pinin knockdown cell lines shared significant overlap of differentially expressed genes and RNA splicing aberrations with CtBP1 knockdown and in a lesser degree with CtBP2 knockdown cancer cells. Hence, Pinin and CtBP are oncotargets that closely interact with each other to regulate transcription and pre-mRNA alternative splicing and promote cell adhesion and other epithelial characteristics of ovarian cancer cells.

Progranulin and its biological effects in cancer

Cancer cells have defects in regulatory mechanisms that usually control cell proliferation and homeostasis. Different cancer cells share crucial alterations in cell physiology, which lead to malignant growth. Tumorigenesis or tumor growth requires a series of events that include constant cell proliferation, promotion of metastasis and invasion, stimulation of angiogenesis, evasion of tumor suppressor factors, and avoidance of cell death pathways. All these events in tumor progression may be regulated by growth factors produced by normal or malignant cells. The growth factor progranulin has significant biological effects in different types of cancer. This protein is a regulator of tumorigenesis because it stimulates cell proliferation, migration, invasion, angiogenesis, malignant transformation, resistance to anticancer drugs, and immune evasion. This review focuses on the biological effects of progranulin in several cancer models and provides evidence that this growth factor should be considered as a potential biomarker and target in cancer treatment.

Clinical implications of progranulin in gastric cancer and its regulation via a positive feedback loop involving AKT and ERK signaling pathways

In previous years, progranulin (PGRN) has attracted increasing attention due to its oncogenic roles in several types of tumor. However, the clinical relevance of PGRN in gastric cancer remains to be elucidated. In the present study, 120 retrospective tissue samples were obtained from patients with primary gastric cancer, and the expression of PGRN was detected using immunohistochemistry. The results showed that 71 cases exhibited a high expression of PGRN, which was markedly higher than the 49 cases with a low expression of PGRN. Subsequent χ2 analysis confirmed for the first time, to the best of our knowledge, that a high level of PGRN was positively correlated with lymph node metastasis (P=0.048), lymphatic invasion (P=0.018) and advanced clinical stage (P=0.027). Survival analysis showed that PGRN was positively correlated with poorer overall survival (OS; P=0.0043) and progression‑free survival (PFS; P=0.0022). Univariate and multivariate Cox regression analysis showed that PGRN and clinical stage had a significant effect on the OS and PFS of the patients with gastric cancer. In addition, cell experiments confirmed that extracellular PGRN promoted the intracellular expression of PGRN in a concentration‑dependent manner in gastric cancer cells. The AKT and extracellular signal‑regulated kinase signaling pathways were involved in the upregulation of intracellular PGRN induced by extracellular PGRN in MKN‑45 and MGC‑803 gastric cancer cells. Taken together, the results of the present study suggested that PGRN may be important in the progression and prognosis of gastric cancer, and that the expression of PGRN was regulated in a positive feedback loop. These findings enhance current knowledge regarding PGRN in tumors.

miRNA-expression in tonsillar squamous cell carcinomas in relation to HPV infection and expression of the antileukoproteinase SLPI

The aim of this study was to determine if micro-(mi-)RNAs are involved in the previously reported inverse correlation between the antileukoproteinase SLPI, HPV, and smoking habit of head and neck squamous cells carcinoma (HNSCC) patients. HPV-status and SLPI-protein expression were determined in tonsillar SCC (TSCC; n=126). Differentially expressed miRNAs dependent on HPV-status and SLPI-expression were detected by microarray; possible binding-sites in SLPI- and HPVE6-mRNAs were determined in silico. Survival rates were estimated testing prognostic values of HPV-status, SLPI- and miRNA-expression. miRNA-array identified 24 up-regulated and 10 down-regulated miRNAs in HPV-positive versus HPV-negative TSCC (p<0.01; HPV-positivity: 42.1%). HPV-positivity resulted in two up-regulated miRNAs in SLPI-positive TSCC. Of 16 further miRNAs, eight miRNAs were up- and eight were down-regulated in SLPI-negative TSCC. RT-q-PCR-validation of the four most differentially expressed miRNAs showed that miR-363 is expressed strongest in SLPI-negative/HPV-positive TSSC. In silico-analysis of all differentially expressed miRNAs identified miR-363, miR-210, miR-130a, and miR-181a with possible binding sites in the HPV16-E6-mRNA, but none were predicted in the SLPI-mRNA. HPV-positivity, low SLPI-levels and high miR-363-levels are significantly associated with better survival rates. The data presented here show that miR-363 is associated with HPV-positive/SPLI-negative TSCC. The prognostic value of miR-363 suggests a role in the assumed inverse correlation of smoking and SPLI-expression in the mode of HPV-infections in tonsillar but possibly also other HNSCC.

Progranulin and short-term outcome in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

Stroke is a leading cause of death and severe disability worldwide. Serum biomarkers play a critical role in the assessment of the severity and prognosis in stroke patients.

METHODS

In this prospective cohort study, the measurement of serum progranulin (PGRN) was conducted in 316 participants, including 216 patients with an identified diagnosis of acute ischaemic stroke and 100 normal control subjects. The primary end-point was defined as all-cause mortality for a short-term follow-up of 6 months. Adverse functional outcome (modified Rankin Scale score ≥3) was considered as the secondary end-point.

RESULTS

The median value of serum PGRN for patients with acute ischaemic stroke was 64.2 ng/ml (interquartile range 54.6-73.7), which was significantly higher than the control group [59.7 (54.4-64.4) ng/ml; P < 0.001]. Multivariable linear regression suggested that PGRN levels were significantly correlated with body mass index, alcohol consumption, fasting blood glucose, total cholesterol, National Institutes of Health Stroke Scale (NIHSS) score and high-density lipoprotein cholesterol. Serum PGRN concentrations were independently associated with increased risks of all-cause mortality and adverse functional outcome after adjustment for clinical variables. In Cox proportional hazards models, PGRN levels were associated with the risk of mortality (hazard ratio 1.090, 95% confidence interval 1.033-1.150, P = 0.002). The net reclassification improvement of the model with added PGRN was 0.1902 (P = 0.0234) after adjustment for the variables in the Cox regression model for predicting all-cause mortality, and the integrated discrimination improvement was 0.1052 (P < 0.001).

CONCLUSIONS

Serum PGRN levels independently predicted all-cause mortality and adverse functional outcome in the short term in stroke patients. The discriminative power was improved by PGRN on the basis of NIHSS score.

Mechanisms of Progranulin Action and Regulation in Genitourinary Cancers

The growth factor progranulin has emerged in recent years as a critical regulator of transformation in several cancer models, including breast cancer, glioblastomas, leukemias, and hepatocellular carcinomas. Several laboratories, including ours, have also demonstrated an important role of progranulin in several genitourinary cancers, including ovarian, endometrial, cervical, prostate, and bladder tumors, where progranulin acts as an autocrine growth factor thereby modulating motility and invasion of transformed cells. In this review, we will focus on the mechanisms of action and regulation of progranulin signaling in genitourinary cancers with a special emphasis on prostate and bladder tumors.

Progranulin promotes colorectal cancer proliferation and angiogenesis through TNFR2/Akt and ERK signaling pathways

Progranulin (PGRN) has been shown to be involved in the process of inflammation, wound healing, and cartilage development; and its role in the progression of breast and ovarian cancer is also well established. However, the expression status of PGRN in colorectal cancers (CRCs) and its molecular mechanisms responsible for tumorigenesis have not been addressed so far. Herein, we demonstrated that PGRN was highly expressed and had clinical relevance with CRCs since its overexpression was associated with advanced stages of CRCs, poorer patients' prognosis, and increased expression of proliferation and angiogenesis markers. PGRN up-regulation significantly promoted the expression of Ki67 and vascular endothelial growth factor A (VEGF-A) as well as the growth rate in CRC cell lines, while PGRN down-regulation had the opposite effects. Strikingly, PGRN derived from CRCs could directly induce proliferation, migration, tubule formation, as well as VEGF-A expression in human umbilical vein endothelial cells (HUVECs). Furthermore, we provided mechanistic evidences that the regulation of Ki67 and VEGF-A expression by PGRN was mediated by tumor necrosis factor receptor 2 (TNFR2)/Akt and the ERK signaling pathways in both CRC cells and HUVECs. Taken together, these findings suggested that PGRN could promote proliferation and angiogenesis through TNFR2/Akt and ERK signaling pathways in CRCs, providing the new insight into the mechanism of PGRN in tumor proliferation and angiogenesis.

The antileukoprotease secretory leukocyte protease inhibitor (SLPI) and its role in the prevention of HPV-infections in head and neck squamous cell carcinoma

Recently, we demonstrated a significant inverse correlation between HPV-infection and SLPI-expression suggesting that SLPI protects against HPV-infection of HNSCC. Here we analyzed in a single lab setting 307 formalin-fixed paraffin-embedded HNSCC cases (tonsillar n = 135; non-tonsillar: n = 172) from eight health care centers. Samples were analyzed for SLPI gene- and protein-expression. Annexin A2, its heterotetramer A2t, putatively facilitating HPV- and SLPI-cell entry, was measured to study the correlation between SLPI and annexin A2. Data were correlated with tobacco consumption and HPV-status. Overall, HPV-DNA prevalence was 23.5% (72/307); attributed to: 43.7% (59/135) tonsillar and 7.6% (13/172) non-tonsillar cases. Smoking resulted in 6.44-fold increased and HPV-infection in 3.46-fold decreased SLPI-gene expression in all HNSCC with similar significant results obtained in tonsillar and non-tonsillar SCC separately. Correlating annexin A2- and SLPI-gene expression showed a significant surplus of annexin A2 in HPV-positive tumors (4.21× more annexin A2) and 6.72× more annexin A2 than SLPI in nonsmokers in all HNSCCs and similar significant results for both tumor entities separately. The surplus of annexin A2 in non-smokers and HPV-positive patients supports our hypothesis that decreased SLPI levels facilitate HPV-infection i.e., increased SLPI-expression may protect against HPV-infection of tonsillar and non-tonsillar SCC.

Secretory leukocyte protease inhibitor is a proliferation and survival factor for pancreatic cancer cells

OBJECTIVES

A variety of inflammatory cytokines have been demonstrated to participate in tumorigenesis and progression. Secretory leukocyte protease inhibitor (SLPI) has been demonstrated to show a broad-spectrum of anti-inflammatory effects. This study investigates the expression of SLPI in human pancreatic cancer tissues and cells as well as its biological effects in human pancreatic cancer cells.

METHODS

Reverse transcription-polymerase chain reaction, immunohistochemistry, and Western blot were used to detect SLPI mRNA and protein levels in human pancreatic cancer tissues, adjacent tissues, and pancreatic cancer Bxpc-3 and Panc-1 cells. Knockout of SLPI expression was established by recombinant viral vector expressing short hairpin RNA (shRNA) targeting SLPI. Cell viability was analyzed by MTT assay. Cell apoptosis was detected by Hochest33258 staining and flow cytometry assay.

RESULTS

Higher SLPI expression was observed in pancreatic tissues, Bxpc-3 cells, and Panc-1 cells compared to the peritumoral tissues (p < 0.01). SLPI expression in Bxpc-3 and Panc-1 cells was effectively silenced by shRNA (p < 0.001). Silencing of SLPI expression significantly reduced cell viability, inhibited cell proliferation, and induced cell apoptosis (p < 0.001).

CONCLUSIONS

Abnormal over-expression of SLPI in pancreatic cancer cells may be associated with the development of disease through its roles in promoting cancer cell survival and proliferation as well as anti-apoptosis. SLPI can be used as a target for developing targeted therapy of pancreatic cancer.

The role of PGRN in musculoskeletal development and disease

Progranulin (PGRN) is a growth factor that has been implicated in wound healing, inflammation, infection, tumorigenesis, and is most known for its neuroprotective and proliferative properties in neurodegenerative disease. This pleiotropic growth factor has been found to be a key player and regulator of a diverse spectrum of multi-systemic functions. Its critical anti-inflammatory role in rheumatoid arthritis and other inflammatory disease models has allowed for the propulsion of research to establish its significance in musculoskeletal diseases, including inflammatory conditions involving bone and cartilage pathology. In this review, we aim to elaborate on the emerging role of PGRN in the musculoskeletal system, reviewing its particular mechanisms described in various musculoskeletal diseases, with special focus on osteoarthritis and inflammatory joint disease patho-mechanisms and potential therapeutic applications of PGRN and its derivatives in these and other musculoskeletal diseases.