Mediation of estrogen mitogenic effect in human breast cancer MCF-7 cells by PC-cell-derived growth factor (PCDGF/granulin precursor)

PGR-KITLG signaling drives a tumor-mast cell regulatory feedback to modulate apoptosis of breast cancer cells

The immune microenvironment constructed by tumor-infiltrating immune cells and the molecular phenotype defined by hormone receptors (HRs) have been implicated as decisive factors in the regulation of breast cancer (BC) progression. Here, we found that the infiltration of mast cells (MCs) informed impaired prognoses in HR(+) BC but predicted improved prognoses in HR(-) BC. However, molecular features of MCs in different BC remain unclear. We next discovered that HR(-) BC cells were prone to apoptosis under the stimulation of MCs, whereas HR(+) BC cells exerted anti-apoptotic effects. Mechanistically, in HR(+) BC, the KIT ligand (KITLG), a major mast cell growth factor in recruiting and activating MCs, could be transcriptionally upregulated by the progesterone receptor (PGR), and elevate the production of MC-derived granulin (GRN). GRN attenuates TNFα-induced apoptosis in BC cells by competitively binding to TNFR1. Furthermore, disruption of PGR-KITLG signaling by knocking down PGR or using the specific KITLG-cKIT inhibitor iSCK03 potently enhanced the sensitivity of HR(+) BC cells to MC-induced apoptosis and exerted anti-tumor activity. Collectively, these results demonstrate that PGR-KITLG signaling in BC cells preferentially induces GRN expression in MCs to exert anti-apoptotic effects, with potential value in developing precision medicine approaches for diagnosis and treatment.

Effects of Non-Ablative Solid-State Vaginal Laser (SSVL) for the Treatment of Vulvovaginal Atrophy in Breast Cancer Survivors after Adjuvant Aromatase Inhibitor Therapy: Preliminary Results

BACKGROUND

One of the side effects of anti-estrogen treatments in breast cancer survivors (BCSs), especially with aromatase inhibitor (AI) treatment, is the frequent appearance of vulvo-vaginal atrophy (VVA). We aim to evaluate the efficacy, safety and feasibility of a new type of non-ablative Solid-State Vaginal Laser (SSVL) treatment in BCSs with VVA.

METHODS

A total of 30 BCSs with a history of AI use and symptoms of VVA were treated with a non-ablative SSVL (LASEmaR 1500™-EUFOTON)in this non-randomized pilot study. The effects of the laser have been evaluated at baseline, 10 wk and 24 wk using a visual analogue scale (VAS), the Vaginal Health Index (VHI), the Vulvar Health Index (VuHI), the Female Sexual Function Index (FSFI), the EORTC QLQ-BR23, the Vaginal Maturation Index (VMI) and vaginal pH.

RESULTS

At 10-week follow-up vs. baseline there were no statistically significant differences in FSFI, lubrication and EORTC QLQ-BR23. In all the subjective (dyspareunia, VHI, VuHI, FSFI, QLQ) and objective parameters (VMI and pH) there was a statistically significant improvement at the 6-month follow-up. Satisfaction was very high (4.7 out of 5), with 95.7% of patients being satisfied, more than or very satisfied.

CONCLUSIONS

Preliminary results of SSVL treatment of VVA and dyspareunia in BCSs after AI treatment suggest clinical improvement, without relevant side effects and with a high degree of satisfaction.

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.

Granulin as an important immune molecule involved in lamprey tissue repair and regeneration by promoting cell proliferation and migration

Progranulin (PGRN) is an autocrine growth factor that regulates cell proliferation, migration, wound healing, and tissue repair in mammals. Lamprey is the most primitive of the extant vertebrates and is regarded as the survivor of a once flourishing group of paleozoic vertebrates, with a history of more than 500 million years. To date, the evolutionary dynamics and the underlying function of the PGRNs remain largely unclear in lamprey. Here, we screened four genes encoding PGRNs from the genomes of Lethenteron reissneri and Petromyzon marinus, including one long form (named Lr-PGRN-L) and three short forms (named Lr-PGRN-S1, Lr-PGRN-S2, and Lr-PGRN-S3), and performed phylogenetic tree, functional domain, and synteny analyses to identify the evolutionary history of the four Lr-PGRNs. In addition, the expressions of the four Lr-pgrn family genes and the immune response against various pathogenic challenges were also investigated. We found that these genes were widely distributed in various tissues of lamprey and performed a variety of functions. Moreover, our results suggest that Lr-PGRN-S1 induces cell migration and proliferation, and is involved in repair after skin and spinal cord injury under appropriate conditions. Our findings are valuable because they improve the understanding of the evolutionary relationship of vertebrate pgrn genes, as well as providing new insights into the diverse and important roles of Lr-PGRNs.

Upregulation of neuronal progranulin mediates the antinociceptive effect of trimetazidine in paclitaxel-induced peripheral neuropathy: Role of ERK1/2 signaling

Neuronal progranulin (PGRN) overexpression is an endogenous adaptive pain defense following nerve injury. It allows the survival of injured neurons to block enhanced nociceptive responses. Trimetazidine (TMZ) is widely used by cardiac patients as an anti-anginal drug, reflecting its anti-ischemic property. TMZ promotes axonal regeneration of sciatic nerves after crush injury. This study explored the interplay between PGRN and extracellular signal-regulated kinases (ERK1/2) to address mechanisms underlying neuropathic pain alleviation following paclitaxel (PTX) administration. Rats were given four injections of PTX (2 mg/kg, i.p.) every other day. Two days after the last dose, rats received TMZ (25 mg/kg) with or without the ERK inhibitor, PD98059, daily for 21 days. TMZ preserved the integrity of myelinated nerve fibers, as evidenced by an obvious reduction in axonal damage biomarkers. Accordingly, it alleviated PTX-evoked thermal, cold, and mechanical hyperalgesia/allodynia. TMZ also promoted ERK1/2 phosphorylation with a profound upsurge in PGRN content. These effects were associated with a substantial increase in Notch1 receptor gene expression and a prominent anti-inflammatory effect with a marked increase in mRNA expression of secretory leukocyte protease inhibitor. Further, TMZ decreased oxidative stress and caspase-3 activity in the sciatic nerve. Conversely, co-administration of PD98059 completely abolished these beneficial effects. Thus, the robust antinociceptive effect of TMZ is largely attributed to upregulating PGRN and Notch1 receptors via ERK1/2 activation.

In Silico and in Vitro Evaluation of Alkaloids from Goniothalamus elegans Ast. for Breast Cancer Treatment

Breast cancer is the leading cause of cancer mortality in women. In this study, liriodenine and lysicamine from Goniothalamus elegans Ast. were investigated for their anti-breast cancer activity based on their molecular interactions with three proteins related to breast cancer. Liriodenine had predicted binding affinities for BRCA1, BRCA2, and estrogen receptor alpha of −6.2, −7.9, and −8.3 kcal/mol, respectively. Lysicamine had predicted binding affinities of −5.8, −7.2, and 7.6 kcal/mol. To evaluate the biological activity of liriodenine and lysicamine, we studied their in vitro cytotoxic effects on MCF-7 cells. These alkaloids showed significant inhibitory effects with IC50 values of 33.31 and 70.03 µM. These results suggest that Goniothalamus elegans could be a promising medical plant for breast cancer treatment. Further studies are needed to understand the molecular mechanisms and improve the toxicity of liriodenine and lysicamine for clinical use.

Progranulin promotes hippocampal neurogenesis and alleviates anxiety-like behavior and cognitive impairment in adult mice subjected to cerebral ischemia

Aims

Cerebral ischemia can lead to anxiety and cognitive impairment due to the loss of hippocampal neurons. Facilitation of endogenous neurogenesis in the hippocampus is a potential therapeutic strategy for alleviating ischemia‐induced anxiety and cognitive impairment. Progranulin (PGRN), a secretory glycoprotein, has been reported to have a mitogentic effect on many cell types. However, it is not clear whether PGRN enhances hippocampal neurogenesis and promotes functional recovery.

Methods

Adult male C57BL/6 mice were subjected to permanent middle cerebral artery occlusion (pMCAO) and injected intracerebroventricularly with recombinant mouse PGRN 30 min after pMCAO. Anxiety‐like behavior was detected by the open field and the elevated plus maze tests, and spatial learning and memory abilities were evaluated by Morris water maze. Neurogenesis was examined by double labeling of BrdU and neural stem cells or neurons markers. For mechanism studies, the level of ERK1/2 and AKT phosphorylation were assessed by western blotting.

Results

Progranulin significantly alleviated anxiety‐like behavior and spatial learning and memory impairment induced by cerebral ischemia in mice. Consistent with the functional recovery, PGRN promoted neural stem cells (NSCs) proliferation and neuronal differentiation in the dentate gyrus (DG) after cerebral ischemia. PGRN upregulated the expression of phosphorylated ERK1/2 and Akt in the DG after cerebral ischemia.

Conclusions

Progranulin alleviates ischemia‐induced anxiety‐like behavior and spatial learning and memory impairment in mice, probably via stimulation of hippocampal neurogenesis mediated by activation of MAPK/ERK and PI3K/Akt pathways. PGRN might be a promising candidate for coping with ischemic stroke‐induced mood and cognitive impairment in clinic.

Progranulin mediates immune evasion of pancreatic ductal adenocarcinoma through regulation of MHCI expression

Immune evasion is indispensable for cancer initiation and progression, although its underlying mechanisms in pancreatic ductal adenocarcinoma (PDAC) are not fully known. Here, we characterize the function of tumor-derived PGRN in promoting immune evasion in primary PDAC. Tumor- but not macrophage-derived PGRN is associated with poor overall survival in PDAC. Multiplex immunohistochemistry shows low MHC class I (MHCI) expression and lack of CD8⁺ T cell infiltration in PGRN-high tumors. Inhibition of PGRN abrogates autophagy-dependent MHCI degradation and restores MHCI expression on PDAC cells. Antibody-based blockade of PGRN in a PDAC mouse model remarkably decelerates tumor initiation and progression. Notably, tumors expressing LCMV-gp33 as a model antigen are sensitized to gp33-TCR transgenic T cell-mediated cytotoxicity upon PGRN blockade. Overall, our study shows a crucial function of tumor-derived PGRN in regulating immunogenicity of primary PDAC.

Immune responses to pancreatic ductal adenocarcinoma can be inhibited by cancer cells. Here the authors show that high levels of progranulin in PDAC inhibits immune responses by reducing MHC class I antigen presentation through enhanced degradation of MHC class I via autophagy.

Circulating Biomarkers in Breast Cancer

Breast cancer management has progressed immensely over the decades, but the disease is still a major source of morbidity and mortality worldwide. Even with enhanced imaging detection and tissue biopsy capabilities, disease can progress on an ineffective treatment before additional information is obtained through standard methods of response evaluation, including the RECIST 1.1 criteria, widely used for assessment of treatment response and benefit from therapy.⁶ Circulating biomarkers have the potential to provide valuable insight into disease progression and response to therapy, and they can serve to identify actionable mutations and tumor characteristics that can direct therapy. These biomarkers can be collected at higher frequencies than imaging or tissue sampling, potentially allowing for more informed management. This review will evaluate the roles of circulating biomarkers in breast cancer, including the serum markers Carcinoembryonic antigen CA15-3, CA27-29, HER2 ECD, and investigatory markers such as GP88; and the components of the liquid biopsy, including circulating tumor cells, cell free DNA/DNA methylation, circulating tumor DNA, and circulating microRNA.

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.

AZP2006, a new promising treatment for Alzheimer's and related diseases

Progranulin (PGRN) is a protein with multiple functions including the regulation of neuroinflammation, neuronal survival, neurite and synapsis growth. Although the mechanisms of action of PGRN are currently unknown, its potential therapeutic application in treating neurodegenerative diseases is huge. Thus, strategies to increase PGRN levels in patients could provide an effective treatment. In the present study, we investigated the effects of AZP2006, a lysotropic molecule now in phase 2a clinical trial in Progressive Supranuclear Palsy patients, for its ability to increase PGRN level and promote neuroprotection. We showed for the first time the in vitro and in vivo neuroprotective effects of AZP2006 in neurons injured with Aβ1-42 and in two different pathological animal models of Alzheimer's disease (AD) and aging. Thus, the chronic treatment with AZP2006 was shown to reduce the loss of central synapses and neurons but also to dramatically decrease the massive neuroinflammation associated with the animal pathology. A deeper investigation showed that the beneficial effects of AZP2006 were associated with PGRN production. Also, AZP2006 binds to PSAP (the cofactor of PGRN) and inhibits TLR9 receptors normally responsible for proinflammation when activated. Altogether, these results showed the high potential of AZP2006 as a new putative treatment for AD and related diseases.

Granulin: An Invasive and Survival-Determining Marker in Colorectal Cancer Patients

Background: Granulin is a secreted, glycosylated peptide—originated by cleavage from a precursor protein—which is involved in cell growth, tumor invasion and angiogenesis. However, the specific prognostic impact of granulin in human colorectal cancer has only been studied to a limited extent. Thus, we wanted to assess the expression of granulin in colorectal cancer patients to evaluate its potential as a prognostic biomarker. Methods: Expressional differences of granulin in colorectal carcinoma tissue (n = 94) and corresponding healthy colon mucosa were assessed using qRT-PCR. Immunohistochemistry was performed in colorectal cancer specimens (n = 97), corresponding healthy mucosa (n = 47) and colorectal adenomas (n = 19). Subsequently, the results were correlated with histopathological and clinical patients’ data. HCT-116 cells were transfected with siRNA for invasion and migration assays. Results: Immunohistochemistry and qRT-PCR revealed tumoral over expression of granulin in colorectal cancer specimens compared to corresponding healthy colon mucosa and adenomas. Tumoral overexpression of granulin was associated with a significantly impaired overall survival. Moreover, downregulation of granulin by siRNA significantly diminished the invasive capacities of HCT-116 cells in vitro. Conclusion: Expression of granulin differs in colorectal cancer tissue, adenomas and healthy colon mucosa. Furthermore, granulin features invasive and migrative capabilities and overexpression of granulin correlates with a dismal prognosis. This reveals its potential as a prognostic biomarker and granulin could be a worthwhile molecular target for individualized anticancer therapy.

A zebrafish model of granulin deficiency reveals essential roles in myeloid cell differentiation

Granulin is a pleiotropic protein involved in inflammation, wound healing, neurodegenerative disease, and tumorigenesis. These roles in human health have prompted research efforts to use granulin to treat rheumatoid arthritis and frontotemporal dementia and to enhance wound healing. But how granulin contributes to each of these diverse biological functions remains largely unknown. Here, we have uncovered a new role for granulin during myeloid cell differentiation. We have taken advantage of the tissue-specific segregation of the zebrafish granulin paralogues to assess the functional role of granulin in hematopoiesis without perturbing other tissues. By using our zebrafish model of granulin deficiency, we revealed that during normal and emergency myelopoiesis, myeloid progenitors are unable to terminally differentiate into neutrophils and macrophages in the absence of granulin a (grna), failing to express the myeloid-specific genes cebpa, rgs2, lyz, mpx, mpeg1, mfap4, and apoeb. Functionally, macrophages fail to recruit to the wound, resulting in abnormal healing. Our CUT&RUN experiments identify Pu.1, which together with Irf8, positively regulates grna expression. In vivo imaging and RNA sequencing experiments show that grna inhibits the expression of gata1, leading to the repression of the erythroid program. Importantly, we demonstrated functional conservation between the mammalian granulin and the zebrafish ortholog grna. Our findings uncover a previously unrecognized role for granulin during myeloid cell differentiation, which opens a new field of study that can potentially have an impact on different aspects of human health and expand the therapeutic options for treating myeloid disorders such as neutropenia or myeloid leukemia.

Anti-progranulin/GP88 antibody AG01 inhibits triple negative breast cancer cell proliferation and migration

BACKGROUND

Triple negative breast cancer (TNBC) is characterized by invasiveness and short survival. Identifying novel TNBC-targeted therapies, to potentiate standard of care (SOC) therapy, is an unmet need. Progranulin (PGRN/GP88) is a biological driver of tumorigenesis, survival, and drug resistance in several cancers including breast cancer (BC). PGRN/GP88 tissue expression is an independent prognostic factor of recurrence while elevated serum PGRN/GP88 level is associated with poor outcomes. Since PGRN/GP88 expression is elevated in 30% TNBC, we investigated the involvement of progranulin on TNBC.

METHODS

The effect of inhibiting PGRN/GP88 expression in TNBC cells by siRNA was investigated. The effects of a neutralizing anti-human PGRN/GP88 monoclonal antibody AG01 on the proliferation and migration of two TNBC cell lines expressing PGRN/GP88 were then examined in vitro and in vivo.

RESULTS

Inhibition of GP88 expression by siRNA and AG01 treatment to block PGRN/GP88 action reduced proliferation and migration in a dose-dependent fashion in MDA-MB-231 and HS578-T cells. Western blot analysis showed decreased expression of phosphorylated protein kinases p-Src, p-AKT, and p-ERK upon AG01 treatment, as well as inhibition of tumor growth and Ki67 expression in vivo.

CONCLUSION

PGRN/GP88 represents a therapeutic target with companion diagnostics. Blocking PGRN/GP88 with antibody treatment may provide novel-targeted solutions in TNBC treatment which could eventually address the issue of toxicity and unresponsiveness associated with SOC.

Progranulin depletion inhibits proliferation via the transforming growth factor beta/SMAD family member 2 signaling axis in Kasumi-1 cells

Progranulin is an autocrine growth factor that promotes proliferation, migration, invasion, and chemoresistance of various cancer cells. These mechanisms mainly depend on the protein kinase B (Akt)/mechanistic target of rapamycin (mTOR) pathway. Recent studies have shown that patients with hematopoietic cancer have elevated serum progranulin levels. Thus, the current study aimed to investigate the role of progranulin in hematopoietic cancer cells and how it modulates their proliferation. Both knockdown of progranulin and progranulin neutralizing antibody treatment inhibited proliferation in several human hematopoietic cancer cell lines. Moreover, progranulin depletion not only decreases the phosphorylation level of the Akt/mTOR pathway but also, surprisingly, increases the expression of transforming growth factor-beta (TGF-β) and phosphorylation of mothers against decapentaplegic homolog 2 (SMAD2) in Kasumi-1 cell. Furthermore, LY2109761, an inhibitor of TGF-β receptor type I/II kinase, and TGF-β neutralizing antibody blocked the inhibition of proliferation induced by progranulin depletion. These data provide new insights that progranulin alters cell proliferation via the TGF-β axis and progranulin could be a new therapeutic target for hematopoietic cancers.

Lysosomal Dysfunction and Other Pathomechanisms in FTLD: Evidence from Progranulin Genetics and Biology

It has been more than a decade since heterozygous loss-of-function mutations in the progranulin gene (GRN) were first identified as an important genetic cause of frontotemporal lobar degeneration (FTLD). Due to the highly diverse biological functions of the progranulin (PGRN) protein, encoded by GRN, multiple possible disease mechanisms have been proposed. Early work focused on the neurotrophic properties of PGRN and its role in the inflammatory response. However, since the discovery of homozygous GRN mutations in patients with a lysosomal storage disorder, investigation into the possible roles of PGRN and its proteolytic cleavage products granulins, in lysosomal function and dysfunction, has taken center stage. In this chapter, we summarize the GRN mutational spectrum and its associated phenotypes followed by an in-depth discussion on the possible disease mechanisms implicated in FTLD-GRN. We conclude with key outstanding questions which urgently require answers to ensure safe and successful therapy development for GRN mutation carriers.

Progranulin/GP88, A Complex and Multifaceted Player of Tumor Growth by Direct Action and via the Tumor Microenvironment

Investigation of the role of progranulin/GP88 on the proliferation and survival of a wide variety of cells has been steadily increasing. Several human diseases stem from progranulin dysregulation either through its overexpression in cancer or its absence as in the case of null mutations in some form of frontotemporal dementia. The present review focuses on the role of progranulin/GP88 in cancer development, progression, and drug resistance. Various aspects of progranulin identification, biology, and signaling pathways will be described. Information will be provided about its direct role as an autocrine growth and survival factor and its paracrine effect as a systemic factor as well as via interaction with extracellular matrix proteins and with components of the tumor microenvironment to influence drug resistance, migration, angiogenesis, inflammation, and immune modulation. This chapter will also describe studies examining progranulin/GP88 tumor tissue expression as well as circulating level as a prognostic factor for several cancers. Due to the wealth of publications in progranulin, this review does not attempt to be exhaustive but rather provide a thread to lead the readers toward more in-depth exploration of this fascinating and unique protein.

Molecular docking simulation and in vitro studies on estrogenic activities of flavonoids from leaves of Carya cathayensis Sarg

The main purpose of this study was to evaluate the estrogenic properties of total flavonoids (TFs) and five flavonoid monomers (cardamonin (Car), pinostrobin chalcone (PC), wogonin (Wo), chrysin (Chr) and Pinocembrin (PI)) from leaves of Carya cathayensis Sarg (LCC). TFs from LCC were isolated and determined using HPLC. The 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were performed to assess the effects of flavonoids on cell proliferation and cell cycle, respectively. The molecular docking technique was applied to investigate binding conformations of the monomers from LCC to the estrogen receptor ERα and ERβ. Gene and protein expression patterns were assessed using quantitative real-time PCR (qRT-PCR) and western blot, respectively. The results showed that TFs, Car, PC, Wo and Chr promoted proliferation of MCF-7 cells and cell transition from the G1 to S phase, and inhabitation of MCF-7 cell proliferation was observed after the treatment of PI. Molecular docking studies confirmed ERs as molecular targets for the monomers. TFs, Car, PC, Wo and Chr from LCC promoted gene expression of ERα, ERβ, progesterone receptor (PR) and pS2. Our collective results demonstrated that TFs and monomers from LCC may exert ER agonist activity through competitively bind to ER, inducing ER upregulation and active ER to estrogen response element (ERE)- independent gene regulation. As an abundant natural product, LCC may provide a novel medicinal source for treatment of diseases caused by estrogen deficiency.

MicroRNA-107 enhances radiosensitivity by suppressing granulin in PC-3 prostate cancer cells

Prostate cancer is the second leading cause of cancer-related death worldwide. Radiotherapy is often applied for the treatment, but radioresistance is a challenge in some patients. MicroRNAs have been reported to be involved in the DNA damage response induced by ionizing radiation and recent studies have reported microRNA-mediated radiosensitivity. In the present study, we found microRNA-107 (miR-107) enhanced radiosensitivity by regulating granulin (GRN) in prostate cancer (PC-3) cells. MiR-107 was downregulated and GRN was upregulated in response to ionizing radiation in PC-3 cells. Overexpression of miR-107 and knockdown of GRN promoted the sensitivity of PC3 cells to ionizing radiation. By rescue experiments of GRN, we revealed that radiosensitivity enhanced by miR-107 can be attenuated by GRN overexpression in PC-3 cells. Furthermore, we showed miR-107 enhanced radiation-induced G1/S phase arrest and G2/M phase transit, and identify delayed apoptosis by suppressing p21 and phosphorylation of CHK2. Collectively, these results highlight an unrecognized mechanism of miR-107-mediated GRN regulation in response to ionizing radiation and may advance therapeutic strategies for the treatment of prostate cancer.

Association of Serum Progranulin Levels With Disease Progression, Therapy Response and Survival in Patients With Metastatic Breast Cancer

BACKGROUND

Progranulin (GP88) is a critical player in breast tumorigenesis. GP88 tumor expression is associated with increased recurrence and mortality, whereas GP88 circulating levels are elevated in patients with breast cancer compared with healthy individuals. We examined here the correlation between serum GP88 levels in patients with metastatic breast cancer (MBC) with overall survival and disease status determined as response to therapy or progression of disease.

PATIENTS AND METHODS

An institutional review board (IRB)-approved study prospectively enrolled 101 patients with MBC at the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center. GP88 serum levels were correlated with patients' disease status determined by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria and survival outcomes by Kaplan-Meier analysis and log rank statistics.

RESULTS

Patients' survival was stratified by serum GP88 level. Patients with serum GP88 < 55 ng/mL had a 4-fold increased survival compared with patients with GP88 > 55 ng/mL. Examination of GP88 serum levels in association with disease status showed a statistically significant association between serum GP88 levels and disease progression or response to therapy while CA15-3 level was only associated to progression.

CONCLUSION

The association of serum GP88 level with survival and disease status suggests the potential of using the serum GP88 test for monitoring disease status in patients with MBC. Measurement of serum GP88 levels in patients with MBC may have clinical value as a cost-effective adjunct to the management of patients with MBC with imaging.

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.

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.

Generation of a novel HEK293 luciferase reporter cell line by CRISPR/Cas9-mediated site-specific integration in the genome to explore the transcriptional regulation of the PGRN gene

Progranulin has multiple functions in several physiological and pathological processes, including embryonic development, wound repair, tumorigenesis, inflammation and neurodegeneration. To investigate the transcriptional regulation of the PGRN gene, a luciferase knock-in reporter system was established in HEK293 cells by integrating luciferase gene in the genome controlled by the endogenous PGRN promoter using CRISPR/Cas9. PCR results demonstrated the site-specific integration of the exogenous luciferase gene into the genome. To validate the novel luciferase knock-in system, a CRISPR/Cas9 transcription activation/repression system for the PGRN gene was constructed and applied to the knock-in system. In addition, phorbol ester (phorbol 12-myristate, 13-acetate), previously reported as activating the expression of PGRN, was applied to the system. The results indicated that luciferase activity was directly correlated with the activity of the PGRN endogenous promoter. This novel system will be a useful tool for investigating the transcriptional regulation of PGRN, and it has great potential in screening the drugs targeting PGRN.

Determination and analysis of agonist and antagonist potential of naturally occurring flavonoids for estrogen receptor (ERα) by various parameters and molecular modelling approach

Most estrogen receptor α (ERα) ligands target the ligand binding domain (LBD). Agonist 17β-estradiol (E₂) and tamoxifen (TM, known SERM), bind to the same site within the LBD. However, structures of ligand-bound complexes show that E₂ and TM induce different conformations of helix 12 (H12). During the molecular modelling studies of some naturally occurring flavonoids such as quercetin, luteolin, myricetin, kaempferol, naringin, hesperidin, galangin, baicalein and epicatechin with human ERα (3ERT and 1GWR), we observed that most of the ligands bound to the active site pocket of both 3ERT and 1GWR. The docking scores, interaction analyses, and conformation of H12 provided the data to support for the estrogenic or antiestrogenic potential of these flavonoids to a limited degree. Explicit molecular dynamics for 50 ns was performed to identify the stability and compatibility pattern of protein-ligand complex and RMSD were obtained. Baicalein, epicatechin, and kaempferol with 1GWR complex showed similar RMSD trend with minor deviations in the protein backbone RMSD against 1GWR-E₂ complex that provided clear indications that ligands were stable throughout the explicit molecular simulations in the protein and outcome of naringin-3ERT complex had an upward trend but stable throughout the simulations and all molecular dynamics showed stability with less than overall 1 Å deviation throughout the simulations. To examine their estrogenic or antiestrogenic potential, we studied the effect of the flavonoids on viability, progesterone receptor expression and 3xERE/3XERRE-driven reporter gene expression in ERα positive and estrogen responsive MCF-7 breast cancer cells. Epicatechin, myricetin, and kaempferol showed estrogenic potential at 5 µM concentration.

The lysosomal function of progranulin, a guardian against neurodegeneration

Progranulin (PGRN), encoded by the GRN gene in humans, is a secreted growth factor implicated in a multitude of processes ranging from regulation of inflammation to wound healing and tumorigenesis. The clinical importance of PGRN became especially evident in 2006, when heterozygous mutations in the GRN gene, resulting in haploinsufficiency, were found to be one of the main causes of frontotemporal lobar degeneration (FTLD). FTLD is a clinically heterogenous disease that results in the progressive atrophy of the frontal and temporal lobes of the brain. Despite significant research, the exact function of PGRN and its mechanistic relationship to FTLD remain unclear. However, growing evidence suggests a role for PGRN in the lysosome-most striking being that homozygous GRN mutation leads to neuronal ceroid lipofuscinosis, a lysosomal storage disease. Since this discovery, several links between PGRN and the lysosome have been established, including the existence of two independent lysosomal trafficking pathways, intralysosomal processing of PGRN into discrete functional peptides, and direct and indirect regulation of lysosomal hydrolases. Here, we summarize the cellular functions of PGRN, its roles in the nervous system, and its link to multiple neurodegenerative diseases, with a particular focus dedicated to recent lysosome-related mechanistic developments.

A Brief Overview of Progranulin in Health and Disease

The purpose of this brief overview of the progranulin protein is to provide a sense of the range and extent of the roles of progranulin in normal physiology and pathology. Progranulin has received attention due to its role in neurodegeneration, where mutation of a single copy of GRN, the gene encoding progranulin, results in frontotemporal dementia, whereas viral delivery of progranulin to the brains of mice exhibiting Parkinson's or Alzheimer's disease phenotypes inhibits the progression of the neurodegenerative phenotypes. Of equal importance, progranulin protects tissues against the harmful effects of poorly controlled inflammation and promotes tissue regeneration after injury at a multitude of sites throughout the body. Progranulin is overexpressed by many types of cancer and contributes to their progression. Given suitable analytical methods and model systems, progranulin offers a wealth of research possibilities.

Progranulin: a new avenue towards the understanding and treatment of neurodegenerative disease

Progranulin, a secreted glycoprotein, is encoded in humans by the single GRN gene. Progranulin consists of seven and a half, tandemly repeated, non-identical copies of the 12 cysteine granulin motif. Many cellular processes and diseases are associated with this unique pleiotropic factor that include, but are not limited to, embryogenesis, tumorigenesis, inflammation, wound repair, neurodegeneration and lysosome function. Haploinsufficiency caused by autosomal dominant mutations within the GRN gene leads to frontotemporal lobar degeneration, a progressive neuronal atrophy that presents in patients as frontotemporal dementia. Frontotemporal dementia is an early onset form of dementia, distinct from Alzheimer's disease. The GRN-related form of frontotemporal lobar dementia is a proteinopathy characterized by the appearance of neuronal inclusions containing ubiquitinated and fragmented TDP-43 (encoded by TARDBP). The neurotrophic and neuro-immunomodulatory properties of progranulin have recently been reported but are still not well understood. Gene delivery of GRN in experimental models of Alzheimer's- and Parkinson's-like diseases inhibits phenotype progression. Here we review what is currently known concerning the molecular function and mechanism of action of progranulin in normal physiological and pathophysiological conditions in both in vitro and in vivo models. The potential therapeutic applications of progranulin in treating neurodegenerative diseases are highlighted.

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.

MiR-145 mediates zebrafish hepatic outgrowth through progranulin A signaling

MicroRNAs (miRs) are mRNA-regulatory molecules that fine-tune gene expression and modulate both processes of development and tumorigenesis. Our previous studies identified progranulin A (GrnA) as a growth factor which induces zebrafish hepatic outgrowth through MET signaling. We also found that miR-145 is one of potential fine-tuning regulators of GrnA involved in embryonic hepatic outgrowth. The low level of miR-145 seen in hepatocarinogenesis has been shown to promote pathological liver growth. However, little is known about the regulatory mechanism of miR-145 in embryonic liver development. In this study, we demonstrate a significant decrease in miR-145 expression during hepatogenesis. We modulate miR-145 expression in zebrafish embryos by injection with a miR-145 mimic or a miR-145 hairpin inhibitor. Altered embryonic liver outgrowth is observed in response to miR-145 expression modulation. We also confirm a critical role of miR-145 in hepatic outgrowth by using whole-mount in situ hybridization. Loss of miR-145 expression in embryos results in hepatic cell proliferation, and vice versa. Furthermore, we demonstrate that GrnA is a target of miR-145 and GrnA-induced MET signaling is also regulated by miR-145 as determined by luciferase reporter assay and gene expression analysis, respectively. In addition, co-injection of GrnA mRNA with miR-145 mimic or MO-GrnA with miR-145 inhibitor restores the liver defects caused by dysregulation of miR-145 expression. In conclusion, our findings suggest an important role of miR-145 in regulating GrnA-dependent hepatic outgrowth in zebrafish embryonic development.

A clinical guide to the management of genitourinary symptoms in breast cancer survivors on endocrine therapy

There is increasing attention and concern about managing the adverse effects of adjuvant endocrine therapy for women with early breast cancer as the side effects of therapy influence compliance and can impair quality of life (QoL). Most side effects associated with tamoxifen (TAM) and aromatase inhibitors (AIs) are directly related to estrogen deprivation, and the symptoms are similar to those experienced during natural menopause but appear to be more severe than that seen in the general population. Prolonged estrogen deprivation may lead to atrophy of the vulva, vagina, lower urinary tract and supporting pelvic structures, resulting in a range of genitourinary symptoms that can in turn lead to pain, discomfort, impairment of sexual function and negatively impact on multiple domains of QoL. The genitourinary side effects may be prevented, reduced and managed in most cases but this requires early recognition and appropriate treatment. We provide an overview of practical clinical approaches to understanding the pathophysiology and the management of genitourinary symptoms in postmenopausal women receiving adjuvant endocrine therapy for breast cancer.

Signaling Pathway of GP88 (Progranulin) in Breast Cancer Cells: Upregulation and Phosphorylation of c-myc by GP88/Progranulin in Her2-Overexpressing Breast Cancer Cells

Her2 is a receptor tyrosine kinase overexpressed in 25% of breast tumors. We have shown that the 88 kDa autocrine growth and survival factor GP88 (progranulin) stimulated Her2 phosphorylation and proliferation and conferred Herceptin resistance in Her2-overexpressing cells. Herein, we report that GP88 stimulates c-myc phosphorylation and upregulates c-myc levels in Her2-overexpressing cells. c-myc phosphorylation and upregulation by GP88 were not observed in non-Her2-overexpressing breast cancer cells. c-myc activation was inhibited upon treatment with ERK, PI3 kinase, and c-src pathway inhibitors, U0126, LY294002, and PP2. GP88 also stimulated c-src phosphorylation, a known upstream regulator of c-myc. Thus, we describe here a signaling pathway for GP88 in Her2-overexpressing cells, with GP88 stimulating Src phosphorylation, followed by phosphorylation and upregulation of c-myc. These data would suggest that targeting GP88 could provide a novel treatment approach in breast cancer.

Wound healing and cancer progression in Opisthorchis viverrini associated cholangiocarcinoma

Infection with the human liver fluke Opisthorchis viverrini induces cancer of the bile ducts, cholangiocarcinoma (CCA). It was shown previously that O. viverrini-secreted proteins accelerate wound resolution in human cholangiocytes. Recombinant Ov-GRN-1 (O. viverrini-derived gene encoding granulin-like growth factor) induced angiogenesis and accelerated mouse wound healing. Given the striking similarities of wound healing and cancer progression, here we discuss the major implications of this finding for an infection-induced cancer of major public health significance in the developing world.

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.

Increased serum GP88 (Progranulin) concentrations in rheumatoid arthritis

GP88 (Progranulin; PGRN) is a secreted glycosylated protein with important functions in several processes, including immune response and cancer growth. Recent reports have shown that PGRN is a therapeutic target for rheumatoid arthritis (RA) because of its capability to bind with tumor necrosis factor receptor (TNFR). However, the serum PGRN level in RA patients has not been investigated. We used enzyme-linked immunosorbent assay (ELISA) to quantify the serum levels of PGRN in 417 healthy subjects, 56 patients with RA and 31 patients with osteoarthritis (OA). In RA patients, we also measured the serum TNF-α and sTNFR concentration. Immunohistochemical staining of PGRN was performed using synovectomy tissue of RA patients. The serum PGRN normal range was established as 40.1 ± 8.7 ng/ml. PGRN levels were not influenced by sex or age. A significant increase in serum PGRN levels was observed in RA (50.2 ± 11.1 ng/ml) and OA (45.4 ± 6.6 ng/ml) groups compared to those in age-matched healthy controls (40.4 ± 9.9 ng/ml) (p<0.05, Tukey). Further, PGRN levels in the synovial fluid of RA patients (68.4 ± 3.4 ng/ml) were found to be significantly higher than those in OA patients (35.9 ± 16.8 ng/ml). Immunohistochemical staining of PGRN revealed that the highest positive signal was detected in macrophages. Circulating PGRN in RA patients was weakly associated with TNF-α and sTNFR 2 concentration. Furthermore, PGRN/TNF-α ratio was correlated the stage of the disease in RA patients. The concentrations of serum PGRN in RA were found to be significantly higher than those in age-matched healthy controls, although it remains to be clarified how blood PGRN is related to the pathogenesis of RA. Our results showed that the serum PGRN may be a useful approach to monitor the disease activity in RA patients.

17β-estradiol induces stearoyl-CoA desaturase-1 expression in estrogen receptor-positive breast cancer cells

Background

To sustain cell growth, cancer cells exhibit an altered metabolism characterized by increased lipogenesis. Stearoyl-CoA desaturase-1 (SCD-1) catalyzes the production of monounsaturated fatty acids that are essential for membrane biogenesis, and is required for cell proliferation in many cancer cell types. Although estrogen is required for the proliferation of many estrogen-sensitive breast carcinoma cells, it is also a repressor of SCD-1 expression in liver and adipose. The current study addresses this apparent paradox by investigating the impact of estrogen on SCD-1 expression in estrogen receptor-α-positive breast carcinoma cell lines.

Methods

MCF-7 and T47D mammary carcinomas cells and immortalized MCF-10A mammary epithelial cells were hormone-starved then treated or not with 17β-estradiol. SCD-1 activity was assessed by measuring cellular monounsaturated/saturated fatty acid (MUFA/SFA) ratios, and SCD-1 expression was measured by qPCR, immunoblot, and immunofluorescence analyses. The role of SCD-1 in cell proliferation was measured following treatment with the SCD-1 inhibitor A959372 and following SCD-1 silencing using siRNA. The involvement of IGF-1R on SCD-1 expression was measured using the IGF-1R antagonist AG1024. The expression of SREBP-1c, a transcription factor that regulates SCD-1, was measured by qPCR, and by immunoblot analyses.

Results

17β-estradiol significantly induced cell proliferation and SCD-1 activity in MCF-7 and T47D cells but not MCF-10A cells. Accordingly, 17β-estradiol significantly increased SCD-1 mRNA and protein expression in MCF-7 and T47D cells compared to untreated cells. Treatment of MCF-7 cells with 4-OH tamoxifen or siRNA silencing of estrogen receptor-α largely prevented 17β-estradiol-induced SCD-1 expression. 17β-estradiol increased SREBP-1c expression and induced the mature active 60 kDa form of SREBP-1. The selective SCD-1 inhibitor or siRNA silencing of SCD-1 blocked the 17β-estradiol-induced cell proliferation and increase in cellular MUFA/SFA ratios. IGF-1 also induced SCD-1 expression, but to a lesser extent than 17β-estradiol. The IGF-1R antagonist partially blocked 17β-estradiol-induced cell proliferation and SCD-1 expression, suggesting the impact of 17β-estradiol on SCD-1 expression is partially mediated though IGF-1R signaling.

Conclusions

This study illustrates for the first time that, in contrast to hepatic and adipose tissue, estrogen induces SCD-1 expression and activity in breast carcinoma cells. These results support SCD-1 as a therapeutic target in estrogen-sensitive breast cancer.

GP88 (progranulin): a novel tissue and circulating biomarker for non-small cell lung carcinoma

GP88 (progranulin) is a growth and survival factor implicated in tumorigenesis and drug resistance. Previous studies showed that GP88 was expressed in breast cancer tissue in inverse correlation with survival. This study evaluates GP88 tissue expression in localized/locally advanced lung cancer and GP88 serum levels in advanced disease. GP88 expression was determined by immunohistochemistry in tumor tissue from non-small cell lung carcinoma (NSCLC) patients, 85 with localized (stage I-II), and 40 with locally advanced disease (stage IIIa) and correlated with clinical outcome. Serum GP88 levels from stage IIIb/IV patients, quantified by enzyme immunoassay were compared with GP88 levels from patients with chronic obstructive pulmonary disease and healthy individuals. GP88 was expressed in more than 80% adenocarcinoma and squamous cell carcinoma in contrast to normal lung or small cell lung cancer. There was a statistically significant inverse association of GP88 expression (GP88 immunohistochemistry score, 3+ versus < 3+) with survival for patients with localized resected NSCLC with hazard ratio (HR) = 2.28 (P = .0076) for disease-free survival and HR = 2.17 (P = .014) for overall survival. A statistically significant decrease in progression-free survival (HR = 2.9; P = .022) for GP88 scores of 3+ versus less than 3+ was observed for stage IIIa after chemoradiotherapy. In addition, serum GP88 was significantly elevated in stage IIIb/IV NSCLC compared with control subjects (49.9 ng/mL versus 28.4 ng/mL; P < .0001). This is the first study demonstrating GP88 tissue and serum expression as a prognostic biomarker in localized and advanced disease. Future research will determine utility of monitoring GP88 and the potential of GP88 expression as a predictive marker for anti-GP88 therapeutics.

Growth factor progranulin contributes to cervical cancer cell proliferation and transformation in vivo and in vitro

OBJECTIVE

The growth factor progranulin (PGRN) is overexpressed in a number of tumors. We aimed to investigate the expression and role of PGRN in cervical cancer tumorigenesis.

METHODS

PGRN expression and secretion was assessed in cells and normal and cancerous cervical tissues by Western blot analysis, ELISA or immunohistochemistry. The role of PGRN in cervical carcinogenesis was explored by cell-proliferation, colony-formation and tumor-growth assays. We assessed the role of PGRN-mediated signaling in the cervical cell with specific inhibitors.

RESULTS

PGRN expression was upregulated in cervical cancer cell lines and tissue. PGRN promoted the transformation of human cervical mucosa epithelial H8 cells in vitro and tumor formation in vivo. Knockdown of PGRN expression in cervical cancer cells in vivo decreased cell proliferation and slowed tumor growth. PGRN stimulated cervical cell proliferation, and transformation was mediated, at least in part, by Akt and Erk signaling.

CONCLUSIONS

PGRN is overexpressed in cervical cancer and promotes the malignant growth and transformation of cervical cells. Therefore, PGRN plays a critical role in carcinogenesis of cervical cancer and shows promise for therapeutic strategies for cervical cancer.

Osteoblastic cell secretome: a novel role for progranulin during risedronate treatment

It is well established that osteoblasts, the key cells involved in bone formation during development and in adult life, secrete a number of glycoproteins harboring autocrine and paracrine functions. Thus, investigating the osteoblastic secretome could yield important information for the pathophysiology of bone. In the present study, we characterized for the first time the secretome of human Hobit osteoblastic cells. We discovered that the secretome comprised 89 protein species including the powerful growth factor progranulin. Recombinant human progranulin (6nM) induced phosphorylation of mitogen-activated protein kinase in both Hobit and osteocytic cells and induced cell proliferation and survival. Notably, risedronate, a nitrogen-containing bisphosphonate widely used in the treatment of osteoporosis, induced the expression and secretion of progranulin in the Hobit secretome. In addition, our proteomic study of the Hobit secretome revealed that risedronate induced the expression of ERp57, HSP60 and HSC70, three proteins already shown to be associated with the prevention of bone loss in osteoporosis. Collectively, our findings unveil novel targets of risedronate-evoked biological effects on osteoblast-like cells and further our understanding of the mechanisms of action of this currently used compound.

Progranulin protects vascular endothelium against atherosclerotic inflammatory reaction via Akt/eNOS and nuclear factor-κB pathways

Objective

Atherosclerosis is considered a chronic inflammatory disease, initiated by activation and dysfunction of the endothelium. Recently, progranulin has been regarded as an important modulator of inflammatory processes; however, the role for prgranulin in regulating inflammation in vascular endothelial cells has not been described.

Method and Results

Signaling pathways mediated by progranulin were analyzed in human umbilical vein endothelial cells (HUVECs) treated with progranulin. Progranulin significantly induced Akt and endothelial nitric oxide synthase (eNOS) phosphorylation in HUVECs, an effect that was blocked with Akt inhibitor. Furthermore, nitric oxide (NO) level, the end product of Akt/eNOS pathway, was significantly upregulated after progranulin treatment. Next, we showed that progranulin efficiently inhibited lipopolysaccharide (LPS)-mediated pro-inflammatory signaling. LPS-induced phosphorylation of IκB and nuclear factor-κB (NF-κB) levels decreased after progranulin treatment. Also, progranulin blocked translocation of NF-κB from the cytosol to the nucleus. In addition, progranulin significantly reduced the expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) by inhibiting binding of NF- κB to their promoter regions and blocked attachment of monocytes to HUVECs. Progranulin also significantly reduced the expression of tumor necrosis factor receptor-α (TNF-α) and monocyte chemo-attractant protein-1 (MCP-1), the crucial inflammatory molecules known to aggravate atherosclerosis.

Conclusion

Progranulin efficiently inhibited LPS-mediated pro-inflammatory signaling in endothelial cells through activation of the Akt/eNOS pathway and attenuation of the NF-κB pathway, suggesting its protective roles in vascular endothelium against inflammatory reaction underlying atherosclerosis.

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

BACKGROUND

Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer-related death in females and leading gynecologic cause of cancer-related death. Despite the identification of a number of serum biomarkers, methods to identify early-stage disease and predict prognosis remain scarce. We have evaluated two biologically connected serum biomarkers, serum leukocyte protease inhibitor (SLPI) and progranulin (PGRN).

METHODS

Two-hundred frozen plasma samples were acquired from the Mayo Clinic Biospecimen Repository for Ovarian Cancer Research. Samples were obtained from 50 patients with benign conditions, 50 with American Joint Committee on Cancer (AJCC) stage I and II EOC, and 100 with AJCC stage III and IV EOC. Samples were obtained before surgical resection of a mass and were analyzed for absolute levels of SLPI and PGRN using ELISA assays. Receiver-operator characteristic curves were generated for SLPI and PGRN. Median follow-up was 48 months.

RESULTS

Absolute levels of SLPI were significantly elevated in patients with EOC compared with benign disease and predicted the presence of EOC (AUC of 0.812; P = 0.04); SLPI remained elevated in the subset of patients with normal CA-125. PGRN levels were not significantly increased in patients with early-stage or late-stage EOC as a whole, but an increase in PGRN levels was associated with decreased overall survival in advanced EOC.

CONCLUSIONS

SLPI levels are elevated in EOC, and SLPI shows promise as a diagnostic biomarker for patients with both elevated and normal CA-125 levels. An increase in PGRN is associated with decreased overall survival.

IMPACT

SLPI is elevated in EOC and warrants investigation in a screening study in women at risk for EOC.

Mechanisms of granulin deficiency: lessons from cellular and animal models

The identification of causative mutations in the (pro)granulin gene (GRN) has been a major breakthrough in the research on frontotemporal dementia (FTD). So far, all FTD-associated GRN mutations are leading to neurodegeneration through a “loss-of-function” mechanism, encouraging researchers to develop a growing number of cellular and animal models for GRN deficiency. GRN is a multifunctional secreted growth factor, and loss of its function can affect different cellular processes. Besides loss-of-function (i.e., mostly premature termination codons) mutations, which cause GRN haploinsufficiency through reduction of GRN expression, FTD-associated GRN missense mutations have also been identified. Several of these missense mutations are predicted to increase the risk of developing neurodegenerative diseases through altering various key biological properties of GRN-like protein secretion, proteolytic processing, and neurite outgrowth. With the use of cellular and animal models for GRN deficiency, the portfolio of GRN functions has recently been extended to include functions in important biological processes like energy and protein homeostasis, inflammation as well as neuronal survival, neurite outgrowth, and branching. Furthermore, GRN-deficient animal models have been established and they are believed to be promising disease models as they show accelerated aging and recapitulate at least some neuropathological features of FTD. In this review, we summarize the current knowledge on the molecular mechanisms leading to GRN deficiency and the lessons we learned from the established cellular and animal models. Furthermore, we discuss how these insights might help in developing therapeutic strategies for GRN-associated FTD.

Frontotemporal lobar degeneration: epidemiology, pathology, diagnosis and management

Frontotemporal lobar degeneration (FTLD) describes a spectrum of clinically, pathologically and genetically heterogeneous neurodegenerative disorders of unknown aetiology. FTLD spectrum disorders collectively represent a leading cause of early-onset dementia, with most cases presenting between 45 and 64 years of age. FTLD is characterized by progressive changes in behaviour, executive dysfunction and/or language impairment and can be differentiated clinically into three frontotemporal dementia (FTD) syndromes as follows: (i) behavioural variant (bvFTD); (ii) semantic dementia (SD); and (iii) progressive nonfluent aphasia (PNFA). Additionally, there is a significant clinical, pathological and genetic overlap between FTD and motor neuron disease/amyotrophic lateral sclerosis (FTD-ALS) and the atypical parkinsonian syndromes, progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). bvFTD is characterized by progressive behavioural impairment and a decline in executive function with frontal lobe-predominant atrophy, SD by a loss of object knowledge with prominent anomia and asymmetrical atrophy of the anterior temporal lobes and PNFA by expressive or motor speech deficits with predominantly left peri-sylvian atrophy. Recent advances in molecular biology and immunohistochemical staining techniques have further classified the FTLD spectrum disorders based upon the predominant neuropathological protein into three main categories: (i) microtubule-associated protein tau (FTLD-TAU); (ii) TAR DNA-binding protein-43 (FTLD-TDP); and (iii) fused in sarcoma protein (FTLD-FUS). Up to 40% of FTD patients report a family history of neurodegenerative illness, and one-third to one-half of familial cases of FTD follow an autosomal dominant inheritance pattern. Mutations in MAPT, PGRN, TARDBP, VCP and CHMP2B have been described, along with a recently identified C9ORF72 hexanucleotide repeat expansion. To date, there are no US FDA-approved treatments or disease-modifying therapies for FTD. Pharmacological strategies have focused on neurotransmitter replacement and modulation for the treatment of behavioural, motor and cognitive symptoms of FTD, and include selective serotonin reuptake inhibitors (SSRIs), atypical antipsychotics, acetylcholinesterase inhibitors and glutamate NMDA receptor antagonists. At present, adequate management of FTD symptoms involves a combination of pharmacological therapy with behavioural, physical and environmental modification techniques.

Circulating progranulin levels in women with gestational diabetes mellitus and healthy controls during and after pregnancy

OBJECTIVE

Progranulin (PGRN) was recently introduced as a novel marker of chronic inflammatory response in obesity and type 2 diabetes capable of directly affecting the insulin signaling pathway. This study aimed to investigate the role of PGRN in gestational diabetes mellitus (GDM), which is regarded as a model for early type 2 diabetes.

METHODS

PGRN serum levels were measured in 90 pregnant women (45 GDM and 45 normal glucose tolerance (NGT)). In addition, PGRN was measured during a 2-h, 75 g oral glucose tolerance test in 20 pregnant women (ten GDM and ten NGT) and in 16 of them post partum (ten GDM and six NGT).

RESULTS

PGRN concentrations were significantly higher in pregnant women compared with post partum levels (536.79 ± 31.81 vs 241.53 ± 8.86, P<0.001). Multivariate regression analyses showed a strong positive correlation of PGRN with estrogen and progesterone. The insulinogenic index, a marker of early insulin secretion, displayed a positive correlation with PGRN, both during and after pregnancy (R=0.47, P=0.034; R=0.63, P=0.012). HbA1c and the oral glucose insulin sensitivity index showed significant post partum associations with PGRN (R=0.43, P=0.049; R=-0.65, P=0.009).

CONCLUSIONS

PGRN concentrations are markedly lower after pregnancy regardless of the gestational glucose tolerance state. PGRN levels per se do not discriminate between mild GDM and NGT in pregnant women. Therefore, the development of GDM appears to be due to impaired β-cell function that is not related to PGRN effect.

Zoledronic acid effectiveness against breast cancer metastases - a role for estrogen in the microenvironment?

Zoledronic acid (ZA) is an imidazole-containing bisphosphonate that has been extensively studied as an osteoclast inhibitor. ZA decreases bone turnover and has been effective in limiting osteolysis in metastatic cancers, including breast cancer. Recent clinical trials that demonstrated enhancement of disease-free survival by bisphosphonates have prompted interest in bisphosphonates as anti-cancer agents. ZA, for example, increased disease-free survival in postmenopausal and in premenopausal, hormone-suppressed breast cancer patients. Intriguingly, however, there was a lack of an anti-cancer effect of ZA in premenopausal women without ovarian suppression. These observations have prompted the conjecture that anti-cancer effects of ZA are limited to estrogen-poor environments. This review explores possible mechanisms compatible with differences in ZA activity in premenopausal women compared with postmenopausal (or hormone-suppressed) women.

Progranulin (GP88) tumor tissue expression is associated with increased risk of recurrence in breast cancer patients diagnosed with estrogen receptor positive invasive ductal carcinoma

Introduction

GP88 (progranulin) has been implicated in tumorigenesis and resistance to anti-estrogen therapies for estrogen receptor positive (ER⁺) breast cancer. Previous pathological studies showed that GP88 is expressed in invasive ductal carcinoma (IDC), but not in normal mammary epithelial tissue, benign lesions or lobular carcinoma. Based on these results, the present study examines GP88 prognostic significance in association with recurrence and death risks for ER⁺ IDC patients.

Methods

Two retrospective multi-site clinical studies examined GP88 expression by immunohistochemistry (IHC) analysis of paraffin-embedded breast tumor tissue sections from ER⁺ IDC patients (lymph node positive and negative, stage 1 to 3) in correlation with patients' survival outcomes. The training study established a GP88 cut-off value associated with decreased disease-free (DFS) and overall (OS) survivals. The validation study verified the GP88 cut-off value and compared GP88 prognostic information with other prognostic factors, particularly tumor size, grade, disease stage and lymph node status in multivariate analysis.

Results

GP88 expression is associated with a statistically significant increase in recurrence risk for ER⁺ IDC patients. The training study established that GP88 3+ score was associated with decreased DFS (P = 0.0004) and OS (P = 0.0036). The independent validation study verified that GP88 3+ score was associated with a 5.9-fold higher hazard of disease recurrence and a 2.5-fold higher mortality hazard compared to patients with tumor GP88 < 3+. GP88 remained an independent risk predictor after considering age, ethnicity, nodal status, tumor size, tumor grade, disease stage, progesterone receptor expression and treatments.

Conclusions

The survival factor GP88 is a novel prognostic biomarker, predictive of recurrence risk and increased mortality for non-metastatic ER⁺ IDC patients. Of importance, our data show that GP88 continues to be a prognostic factor even after five years. These results also provide evidence that GP88 provides prognostic information independent of tumor and clinical characteristics and would support prospective study to examine whether GP88 expression could help stratify patients with ER⁺ tumors for adjuvant therapy.