Lactoferrin Receptor Research Articles

Dexamethasone and lactoferrin induced PMN-MDSCs relieved inflammatory adverse events of anti-cancer therapy without tumor promotion

In this era of immune checkpoint inhibitors, inflammatory adverse events of anti-cancer therapies continue to pose a major challenge. Glucocorticoids, as the mainstay, were limited by serious side effects. Glucocorticoids induce myeloid-derived suppressor cells (MDSCs), and lactoferrin-induced polymorphonuclear MDSCs (PMN-MDSCs) were shown to relieve inflammatory conditions. Combined treatment with dexamethasone (DXM) and lactoferrin increased the generation of PMN-MDSCs in vitro (DXM/lactoferrin PMN-MDSCs) compared to DXM or lactoferrin treatment alone. DXM/lactoferrin PMN-MDSCs were distinct from tumor PMN-MDSCs in vivo with regard to gene expression profiles. DXM upregulated the myeloid cell response to lactoferrin by inducing the lactoferrin receptor Lrp1. DXM/lactoferrin PMN-MDSCs presented anti-bacterial capability, increased PGE2 production, increased survival capability, and decreased tumor tissue homing. Transfer of DXM/lactoferrin PMN-MDSCs relieved cisplatin-induced acute kidney failure, bleomycin-induced interstitial pneumonia, and allergic pneumonitis effectively without promoting tumor development. Our study shows that DXM/lactoferrin PMN-MDSCs are a promising cell therapy for inflammatory adverse events of anti-cancer therapies.

Abstract 6236: Mil protein-shelled gold nanoparticle to treat glioblastoma multiform

Abstract Gold nanoparticle (AuNP) as a photothermal therapy (PTT) agent has been reported in various application due to its physical properties. If gold nanoparticle can be orally absorbed, its application may be extended. Unfortunately, it has low absorption efficiency from the gastrointestinal (GI) tract to blood stream. To overcome its limitation orally, here we newly synthesized lactoferrin (Lf; a milk protein)-conjugated gold nanoparticles (Lf-AuNP). Interestingly, this Lf-AuNP could be orally absorbed and targeted to the brain cancer cells due to its interaction with lactoferrin receptor (Lf-R) on the intestinal cells, Blood-Brain Barrier (BBB) and cancer cells. Based on these findings, the Lf-AuNP was orally absorbed with higher bioavailability and targeted to the brain cancer cells (U87MG cells) that was orthotopic animal model. Fortunately, when specified wavelength of laser was noninvasively irradiated to the head of orthotopic animals, the Lf-AuNP made the higher temperature to the head, thereby killing the brain cancer cells. Collectively this milk protein-based oral delivery of AuNP could be a promising strategy as a platform technology. Citation Format: Hyungshik Kim, In-Kyu Park, Kang-Moo Huh, Dong-Yun Lee. Mil protein-shelled gold nanoparticle to treat glioblastoma multiform [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6236.

The Lactoferrin Receptor Is Differentially Expressed in Different Regions of Brain and Responds to LF Intervention in Piglets

Abstract Objectives To molecular characterize the expression levels of lactoferrin receptor (LfR) in different regions of brain and its response to lactoferrin (LF) intervention in piglets. Methods 3-day-old male piglets were randomly allocated to groups (Grp) 1 fed milk replacer supplemented with LF 1.1 g/L (n = 16) and Grp 2 0.06 g/L (n = 16) as control. Piglets were euthanised at 38 days of age. Gene and protein expression of LfR was analysed using we published methods (1). Study protocol has been approved by animal ethic committee of Xiamen University. Results Our results showed that the cellular levels of mRNA coding for LfR was differentially expressed in ten sub-regions of piglet's brain. The highest expression level of LfR gene was found in the prefrontal cortex (PF, 20.45 ± 2.11) following by the parietal lobe (PL), brainstem (BS), occipital lobe (OL), sub ventricular zone (SVZ), olfactory bulb (OB), hippocampus (Hip), amygdala (Amy), cerebellum (CE) and thalamus (THA) respectively. The mRNA expression of LfR in the PF was ∼15% time higher than that of thalamus (THA, 1.38 ± 0.549). Overall differences between sub-regions of brain were highly significant. There was a positive correlation between expression level of mRNA and protein of the tested tissues. LfR expression in different regions of brain significantly responded to dietary LF intervention in piglets (P < 0.05). Conclusions We demonstrated that LfR differentially expressed in different regions of brain and responded to dietary LF intervention in pigleta, an animal model of human infant. The cellular abundance of LfR in ten subregions of piglet brain is regulated at the level of transcription. The role of LfR in neurodevelopment is under investigation. Funding Sources Medical School of Xiamen University.

Osteogenic activity of lactoferrin and its application in contemporary dentistry

AbstractIntroduction: Lactoferrin (Lf) is a protein in the transfer-rin family with many biological functions. One novel activity of lactoferrin described recently is its regulatory function in bone morphogenesis. Lactoferrin has been shown to promote the growth, development, and differentiation of osteoblasts as well as to decrease osteoclast survival. Lactoferrin receptors (LfRs) mediate the multiple functions of lactoferrin. This review focuses on LfRs associated with bone and the intestines. The best known LfR is small intestine LfR (intelectin), which facilitates iron absorption and iron metabolism in humans. Many data fromin vitroandin vivostudies have indicated that lactoferrin promotes bone formation by increasing the proliferation of osteoblasts and the ability of cells to synthesize and mineralize the bone matrix. Lactoferrin additionally inhibits osteoclastogenesis, reducing the number of osteoclasts and thus bone resorption. Lactoferrin, with its numerous antimicrobial, anti-inflammatory, and also osteogenic properties has found a number of applications in contemporary dentistry, especially in dental surgery, in periodontology, and in pedodontics.Summary: This review presents andin vivo in vitrostudies demonstrating the osteogenic and anti-inflammatory activity of Lf and its practical application in oral surgery and dentistry.

Small-sized gadolinium oxide based nanoparticles for high-efficiency theranostics of orthotopic glioblastoma

Glioblastoma (GBM) is one of the most malignant tumors with poor prognosis and outcomes. Although smaller particle size can lead to higher blood-brain barrier (BBB)-permeability of the nanomaterials, most of the reported BBB-crossable nanomaterials for targeted GBM therapy are larger than 24 nm. To realize theranostics of GBM, co-loading of therapeutic and diagnostic agents on the same nanomaterials further results in larger particle size. In this study, we developed a kind of novel BBB-transportable nanomaterials smaller than 14 nm for high-efficiency theranostics of GBM (i.e., high contrast magnetic resonance imaging (MRI) and radiosensitization of GBM). Typically, poly(acrylic acid) (PAA) stabilized extremely small gadolinium oxide nanoparticles with modification of reductive bovine serum albumin (ES-GON-rBSA) was synthesized in water phase, resulting in excellent water-dispersibility. RGD dimer (RGD2, Glu-{Cyclo[Arg-Gly-Asp-(D-Phe)-Lys]}2) and lactoferrin (LF) were then conjugated to the ES-GON-rBSA to obtain composite nanoparticle ES-GON-rBSA-LF-RGD2 with extraordinary relaxivities (r1 = 60.8 mM−1 s−1, r2/r1 = 1.1). The maximum signal enhancement (ΔSNR) for T1-weighted MRI of tumors reached up to 423 ± 42% at 12 h post-injection of ES-GON-rBSA-LF-RGD2, which is much higher than commercial Gd-chelates (<80%). ES-GON-rBSA-LF-RGD2 exhibited high biocompatibility and can transport across the in vitro BBB model and the in vivo BBB of mice due to its small particle size (dh = 13.4 nm) and LF receptor mediated transcytosis. Orthotopic GBM studies reinforce that ES-GON-rBSA3-LF-RGD2 can accumulate in the orthotopic GBM and enhance the radiation therapy of GBM as an effective radiosensitizing agent.

The bovine Lactoferrin-Osteopontin complex increases proliferation of human intestinal epithelial cells by activating the PI3K/Akt signaling pathway

Lactoferrin (LF) and osteopontin (OPN), multifunctional proteins involved in cell proliferation, can form a complex. LF binds iron, whereas OPN binds calcium. We investigated whether iron- and calcium-binding influences complex formation and the pro-proliferation property of the LF-OPN complex, and the mechanism behind this effect. LF-OPN complexes were prepared using bovine milk LF and OPN, and effects on proliferation of human intestinal epithelial cells (HIECs) were evaluated using a BrdU proliferation assay. Of the four complexes formed by apo- and holo-LF/OPN, the apo-Lf&holo-OPN complex (AH) exhibited the strongest pro-proliferative effect on HIECs, and we therefore focused on AH. AH was resistant to in vitro gastrointestinal digestion, co-localized with both LF and OPN receptors as revealed by confocal microscopy, and stimulated proliferation of HIECs by activating PI3K/Akt signaling. In conclusion, forming a LF-OPN complex may help both proteins to resist digestion and increase the capacity to promote intestinal development in infants.

The N125S polymorphism in the cathepsin G gene (rs45567233) is associated with susceptibility to osteomyelitis in a Spanish population.

Osteomyelitis is a bone infection, most often caused by Staphylococcus aureus, in which neutrophils play a key role. Cathepsin G (CTSG) is a bactericidal serine protease stored in the neutrophil azurophilic granules. CTSG regulates inflammation, activating matrix metalloproteinases (MMPs), and coagulation. Lactoferrin (LF), a neutrophil glycoprotein, increases CTSG catalytic activity and induces inflammation. The aim of this study was to analyze a potential association between a CTSG gene polymorphism (Asn125Ser or N125S, rs45567233), that modifies CTSG activity, and could affect susceptibility to, or outcome of, bacterial osteomyelitis. CTSG N125S polymorphism was genotyped in 329 osteomyelitis patients and 415 controls), Blood coagulation parameters, serum CTSG activity, LF, MMP-1, MMP-13, and soluble receptor activator for nuclear factor κ B ligand (sRANKL) levels were assessed in carriers of the different CTSG genotypes. CTSG N125S (AG) genotype was significantly more frequent among osteomyelitis patients than controls (15.5% vs. 9.4%, p = 0.014). CTSG N125S variant G allele (AG +GG) was also more frequent among osteomyelitis patients (8.1% vs. 4.7%, p = 0.01). Serum CTSG activity and LF levels were significantly higher in osteomyelitis patients carrying the G allele compared to those with the AA genotype, (p<0.04). Serum MMP-1 was lower in the G allele carriers (p = 0.01). There was no association between these genotypes and clinical characteristics of osteomyelitis, or coagulation parameters, MMP-13, and sRANKL serum levels. Differences in the CTSG gene might enhance osteomyelitis susceptibility by increasing CTSG activity and LF levels.

The Effects of the Combination of Oral Lactoferrin and Iron Injection on Iron Homestasis, Antioxidative Abilities and Cytokines Activities of Suckling Piglets.

Simple SummaryPrevious studies have shown that an iron injection alleviates iron deficiency in suckling piglets, but decreases the fractional iron absorption and causes acute poisoning with poor efficiency of antioxidant system, and has other undesirable side effects. Lactoferrin is a critical regulator of iron absorption and oxidative stress. The present results showed that the combination of oral lactoferrin and iron injection is a more effective method to improve iron level, enhance antioxidant ability and modulate the cytokine activity in the suckling piglets.Iron deficiency is considered a common nutritional problem for suckling piglets. The aim of this study was to evaluate the effects of the combination of oral lactoferrin and iron injection on iron levels, antioxidant ability and cytokine activity in suckling piglets. A total of sixty suckling piglets taken from six sows (10 piglets per litter) with a similar parity were chosen. The lactoferrin (LF) group was orally administrated with lactoferrin solution (0.5 g/kg body weight per day) for a week, the CON group was orally administrated with the same dose of physiological saline. Each piglet (all groups) was given 100 mg of iron dextran (FeDex) by intramuscular injection at the third day of age. Six piglets (n = 6) from each group were euthanized on days 8 and 21. The oral lactoferrin improved the iron level of suckling piglets by increasing the concentrations of serum hemoglobin and hepatic iron on day 8. Gene expression of lactoferrin receptor (LFR) was significantly increased in the LF group piglets on day 8, while duodenal protein expression of the divalent metal transporter 1 (DMT1) was significantly reduced in the LF group on day 8. In addition, oral lactoferrin enhanced serum T-AOC activities and duodenal SOD activities on day 21. The LF piglets had a significantly increased serum concentration of IL-10 on day 8. These results indicated that a combination of oral lactoferrin and iron injection is a more effective method of improving the iron level by up-regulating the expression of the LFR gene, enhancing the antioxidant ability and modulating the cytokine activity in the suckling piglets.

Dual-Targeted Lactoferrin Shell-Oily Core Nanocapsules for Synergistic Targeted/Herbal Therapy of Hepatocellular Carcinoma.

Herein, both strategies of synergistic drug combination together with dual active tumor targeting were combined for effective therapy of hepatocellular carcinoma (HCC). Therefore, based on the tumor sensitizing action, the herbal quercetin (QRC) was co-delivered with the targeted therapeutic drug sorafenib (SFB), preformulated as phospholipid complex, via protein shell-oily core nanocapsules (NCs). Inspired by the targeting action of lactoferrin (LF) via binding to LF receptors overexpressed by HCC cells, LF shell was electrostatically deposited onto the drug-loaded oily core to elaborate LF shell-oily core NCs. For dual tumor targeting, lactobionic acid (LA) or glycyrrhetinic acid (GA) was individually coupled to LF shell for binding to asialoglycoprotein and GA receptors on liver cancer cells, respectively. Compared to LF and GA/LF NCs, the dual-targeted LA/LF-NCs showed higher internalization into HepG2 cells with 2-fold reduction in half-maximal inhibitory concentration compared to free combination therapy after 48 h. Moreover, dual-targeted LF-NCs showed powerful in vivo antitumor efficacy. It was revealed as significant downregulation of the mRNA expression levels of nuclear factor-kappa B and tumor necrosis factor α as well as suppression of Ki-67 protein expression level in diethylnitrosamine (DEN)-induced HCC mice (P < 0.05). Furthermore, dual-targeted LF-NCs attenuated the liver toxicity induced by DEN in animal models. Overall, this study proposes dual-targeted LF-NCs for combined delivery of SFB and QRC as a potential therapeutic HCC strategy.

Cellular Uptake and Release of Intact Lactoferrin and Its Derivatives in an Intestinal Enterocyte Model of Caco-2 Cells.

An Intact form of lactoferrin (LF) is known to be absorbed from the small intestine and transported into the blood circulation. We reevaluated the cellular uptake and release of LF using an enterocyte model of human small intestinal cells derived from the Caco-2 cell line. In contrast to a previous report, we observed that intact bovine LF was taken up into seven and 21 d-cultured Caco-2 cells and successfully released back into the culture medium, even though the human intestinal LF receptor, intelectin-1, was not immunochemically detectable. Similar observations were made for human LF and its derivatives (the N-terminal half of LF designated N-lobe and Fc fusions). These observations regarding the uptake and release of intact LF in Caco-2 cells were consistent with in vivo observations. Therefore, we propose that the uptake and release of intact LF by Caco-2 cells should be assessed as a potential in vitro model of in vivo LF absorption in human intestines.

Lactoferrin promotes hair growth in mice and increases dermal papilla cell proliferation through Erk/Akt and Wnt signaling pathways

Hair loss affects men and women of all ages. Dermal papilla (DP) plays a crucial role in regulating the growth and cycling of hair follicles. Lactoferrin (LF) exhibits a wide range of biological functions, including antimicrobial activity and growth regulation. However, its effect on DP and its role in hair growth remain unknown. In this study, we found that bovine LF (bLF) promoted the proliferation of DP cells and enhanced the phosphorylation of Erk and Akt. The bLF-mediated proliferation was significantly blocked by the Erk phosphorylation inhibitor PD98059 or the Akt phosphorylation inhibitor LY294002. Moreover, biotin-labeled bLF could bind to DP cells, and the binding was independent of lipoprotein receptor-related protein 1, a known LF receptor. Importantly, bLF stimulated hair growth in both young and aged mice. Moreover, we also found that bLF significantly induced the expression of Wnt signaling-related proteins, including Wnt3a, Wnt7a, Lef1, and β-catenin. The bLF-mediated DP cell proliferation could be significantly reversed by the Wnt pathway inhibitor XAV939. Our findings suggest that bLF promotes hair growth in mice and stimulates proliferation of DP cells through Erk/Akt and Wnt signaling pathways. This study highlights a great potential of the use of bLF in developing drugs to treat hair loss.

CARMUSTINE LOADED LACTOFERRIN NANOPARTICLES DEMONSTRATES AN ENHANCED ANTIPROLIFERATIVE ACTIVITY AGAINST GLIOBLASTOMA IN VITRO

Objective: Despite sophisticated treatment regimens, there is no significant improvement in the mortality rates of glioblastoma due to insufficient dosage delivery, reoccurrence of tumors, higher systemic toxicity, etc. Since brain endothelial cells and glioblastoma cells express lactoferrin receptors, a target-specific drug delivery vehicle was developed using lactoferrin itself as a matrix, into which carmustine was loaded. The objective was to use carmustine loaded lactoferrin nanoparticles (CLN) to achieve higher therapeutic efficacy and target specificity compared to free carmustine.Methods: CLN were prepared using the Sol-oil method. The nanoparticles prepared were characterized for their size, shape, polydispersity, and stability using FESEM and DLS methods. Drug loading and drug releasing efficiencies were also estimated. Further, cellular uptake of nanoparticles and their antiproliferative efficacy against glioblastoma cells were evaluated.Results: Characterization of CLN showed that they were spherical with ≤ 41 nm diameter and exhibited homogeneously dispersed stable distribution. Loading efficiency of carmustine in CLN was estimated to be 43±3.7 %. Drug release from the nanoparticles was pH dependent with the maximum observed at pH 5. At physiological and gastric pH, drug release was lower, whereas maximum release was observed at endocytotic vesicular and around tumor extracellular pH. Confocal microscopic studies showed an active cellular uptake of nanoparticles. Results of antiproliferative analysis substantiated a higher antiproliferative effect for CLN compared to free carmustine.Conclusion: The results of the study demonstrated that CLN serves as a vital tool, in designing an effective treatment strategy for targeted drug delivery to glioblastoma.

Lactoferrin Promotes Osteogenesis through TGF-β Receptor II Binding in Osteoblasts and Activation of Canonical TGF-β Signaling in MC3T3-E1 Cells and C57BL/6J Mice

Lactoferrin (LF), as a major functional protein in dairy products, is known to modulate bone anabolic effects. However, the underlying molecular mechanisms remain unclear; the receptor of LF in osteoblast differentiation has not been identified. The aims of the study were to 1) illuminate whether the receptor of LF in osteoblast differentiation is transforming growth factor-β (TGF-β) receptor (TβR) II and 2) determine whether the TGF-β signaling pathway is activated by LF in promoting osteogenesis in vitro and in vivo, in addition to P38 and extracellular signal-regulated kinase (ERK) pathways. We utilized co-immunoprecipitation to detect any binding of LF to TβRII. Subsequently, the role of the TGF-β signaling pathway involved in LF-induced osteoblast proliferation and differentiation was determined by inhibition of TβRI activity by inhibition and knockout of TβRII expression by small guide RNA (sgRNAs) in MC3T3-E1 cells. In addition, 4-wk-old male C57BL/6J mice were orally administered 100 mg LF/kg body weight for 16 wk, after which any activation of the TGF-β signaling pathway in vivo was measured by Western blots. LF was shown to directly interact with the TβRII protein and to activate the TGF-β signaling pathway in MC3T3-E1 cells. Inhibition of TβRI activity and knockout TβRII expression both attenuated the stimulation of LF in osteoblast proliferation and differentiation by 30-50%. LF-induced activation of TGF-β canonical signaling resulted in upregulation of osteogenic factors. Moreover, the expression of phosphorylated-drosophila mothers against decapentaplegic protein 2 (SMAD2) was increased by 1-fold after LF treatment in the femoral tissue of mice. This study provides evidence identifying TβRII as an LF receptor in LF-induced osteoblast differentiation. In addition, the TβRII-dependent TGF-β canonical signaling pathways were proven to play an important role in mediating LF-induced osteogenesis both in MC3T3-E1 cells and in C57BL/6J mice.

Are lactoferrin receptors in Gram-negative bacteria viable vaccine targets?

A number of important Gram-negative pathogens that reside exclusively in the upper respiratory or genitourinary tract of their mammalian host rely on surface receptors that specifically bind host transferrin and lactoferrin as a source of iron for growth. The transferrin receptors have been targeted for vaccine development due to their critical role in acquiring iron during invasive infection and for survival on the mucosal surface. In this study, we focus on the lactoferrin receptors, determining their prevalence in pathogenic bacteria and comparing their prevalence in commensal Neisseria to other surface antigens targeted for vaccines; addressing the issue of a reservoir for vaccine escape and impact of vaccination on the microbiome. Since the selective release of the surface lipoprotein lactoferrin binding protein B by the NalP protease in Neisseria meningitidis argues against its utility as a vaccine target, we evaluated the release of outer membrane vesicles, and transferrin and lactoferrin binding in N. meningitidis and Moraxella catarrhalis. The results indicate that the presence of NalP reduces the binding of transferrin and lactoferrin by cells and native outer membrane vesicles, suggesting that NalP may impact all lipoprotein targets, thus this should not exclude lactoferrin binding protein B as a target.

Cloning and characterization of the human lactoferrin receptor gene promoter.

Lactoferrin (Lf) is a major protein in human milk. Multiple biological functions of Lf are postulated to be mediated by a Lf receptor (LfR). The Lf receptor (LfR) plays an important role in absorption of Lf and Lf-bound iron by intestinal epithelial cells. Here, we cloned and characterized the promoter from a~3.1kb 5'-flanking region of the human LfR gene. Neither a TATA box nor a CCAAT box is found at the typical positions. The transcription start site was identified as 298bp upstream of the translation start codon (+1) by 5' RLM-RACE. A series of deletions of 5'-flanking sequences of the human LfR gene were cloned into a promoter-less pGL3 luciferase reporter and transiently transfected into an intestinal enterocyte model (Caco-2 cells). A fragment of -299/+63 elicited the maximal promoter activity in transfected Caco-2 cells, suggesting that functional transcription factor binding sites appear in the region of -299/+63. Bioinformatics analysis indicates that the -299/+63 fragment contains two putative Sp1 binding sites. The promoter activity was significantly decreased when the Sp1 binding sites were mutated by site-directed mutagenesis. Additionally, the promoter activity was dramatically inhibited by treating cells with an Sp1 inhibitor. Binding of Sp1 to the promoter was confirmed by EMSA. Moreover, after Sp1 expression was significantly suppressed by RNA interference, LfR was significantly decreased at both RNA and protein levels. In conclusion, the LfR gene promoter contains downstream core promoter elements, and the Sp1 binding sites play critical roles in transcriptional regulation of the LfR gene.

Regression of prostate tumors after intravenous administration of lactoferrin-bearing polypropylenimine dendriplexes encoding TNF-α, TRAIL, and interleukin-12

The possibility of using gene therapy for the treatment of prostate cancer is limited by the lack of intravenously administered delivery systems able to safely and selectively deliver therapeutic genes to tumors. Given that lactoferrin (Lf) receptors are overexpressed on prostate cancer cells, we hypothesized that the conjugation of Lf to generation 3-diaminobutyric polypropylenimine dendrimer would improve its transfection and therapeutic efficacy in prostate cancer cells. In this study, we demonstrated that the intravenous administration of Lf-bearing DAB dendriplexes encoding TNFα resulted in the complete suppression of 70% of PC-3 and 50% of DU145 tumors over one month. Treatment with DAB-Lf dendriplex encoding TRAIL led to tumor suppression of 40% of PC-3 tumors and 20% of DU145 tumors. The treatment was well tolerated by the animals. Lf-bearing generation 3-polypropylenimine dendrimer is therefore a highly promising delivery system for non-viral gene therapy of prostate cancer.

Receptor-mediated targeted delivery of DNA using Lactoferrin nanoparticles

Efficient gene delivery facilitated by non-viral vectors, is comparatively safer alternative than viral carriers. Current approaches to gene delivery largely depends on methods that overcome cellular and tissue barriers impeding efficient DNA delivery. While the conventional delivery systems have the drawback of low cellular uptake and off target effects, the receptor-mediated gene delivery system has shown remarkable breakthrough. In that context exploiting the specific receptor targeting properties of lactoferrin protein, we have developed pDNA loaded lactoferrin protein nanoparticles (pDNA-LfNPs). pDNA-LfNPs were spherical in shape within the size range of 140±20nm. They were found to be resistant against nuclease digestion and stable under long storage. Additionally, LfNPs were biocompatible and have targeting ability to facilitate gene uptake by receptor mediated internalization in lactoferrin receptor expressing cell lines. It is also evident from our studies that Lf nanoparticles did not exhibit any cytotoxicity even at the highest concentration. Here we first time report the use of lactoferrin nanoparticles as a gene delivery carrier with targeting abilities.

Lactoferrin promotes autophagy via AMP-activated protein kinase activation through low-density lipoprotein receptor-related protein 1

Lactoferrin (LF) is a multifunctional, iron-binding glycoprotein in mammalian secretions, such as breast milk, and has several beneficial effects for human health. However, how these effects are exerted at the cellular level is still largely unknown. In this study, we investigated the effects of LF on autophagy activity in NIH/3T3 mouse fibroblasts. LF from bovine milk was found to increase LC3-I to LC3-II conversion and LC3-positive cytosolic punctate structures because of increased autophagy flux. Knockdown of the putative LF receptor low-density receptor-related protein 1 (LRP1) completely abolished LC3 conversion in cells by LF treatment. Moreover, exposure to LF increased the phosphorylation levels of AMPK in cells, and treatment of dorsomorphin, a pharmacological inhibitor of AMPK signaling, attenuated LC3 conversion by LF. Therefore, we concluded that the beneficial effects of LF might be due to an increase of autophagy activity via AMPK signaling through the LRP1 receptor. These findings provide a novel insight into the physiological role of LF for the maintenance of cellular and tissue homeostasis.

Lactoferrin-induced growth factors and cytokines expression profile in pre-osteoblast MC3T3-E1 cell and LRP1 stable knockdown MC3T3-E1 cell

Lactoferrin (LF) has been reported to exert beneficial effects on bone health, however, the underlying mechanisms are still not fully understood. Here, we used antibody array to explore the growth factors and cytokines secretion profile in LF-stimulated MC3T3-E1 cell as well as low-density lipoprotein receptor related protein 1 (LRP1) stable knockdown cell. We detected 83 growth factors and cytokines secreted by LF-treated osteoblast, and the levels of Thrombospondin-2 (THBS-2), Interleukin-6 (IL-6), Fibroblast growth factor-basic (FGF-basic), Cysteine-rich angiogenic inducer 61 (Cyr61), Serine protease inhibitor (Serpin) E1, Monocyte chemotactic protein 1 (MCP-1) and Platelet-derived growth factor AA (PDGF-AA) were up-regulated while the Serpin F1 was down-regulated. LF receptor LRP1 only partially involved in LF’s effect on THBS-2 and FGF-basic. This study will contribute to a more comprehensive understanding of the mechanisms by which LF exert beneficial effects on bone cells through the orchestration of cytokines and growth factors network.

Abstract 4661: Omentin as an adjunct to CA-125 in detecting recurrent ovarian cancer

Abstract Omentin (Intestinal Lactoferrin Receptor ITLN1) is an adipokine that is mainly secreted by the mesothelial cells lining visceral adipose tissues. It has been shown in previous studies that ovarian cancer cells down-regulate omentin which allows increased proclivity to spread to the omentum. Levels of serum omentin are decreased in patients with high-grade serous ovarian cancer (HGSOC) compared with patients with benign gynecologic diseases. Moreover, survival correlation studies showed that patients with lower serum omentin level at the time of first treatment experienced significantly shorter survival times than those with higher levels of omentin. CA-125 is currently the only biomarker used to monitor progression and re-occurrence of ovarian cancer. To our best knowledge, the relationship between omentin and CA-125 has not been investigated previously. We hypothesize that omentin may be a clinically useful adjunct to CA-125 in detecting recurrent ovarian cancer. 92 serum samples were collected prospectively from 27 HGSOC patients during the postoperative period until recurrence was detected. Patients had an average of 3.37 follow up visits and CA-125 levels were concurrently established. Recurrence was determined by imaging or an increase from baseline in CA-125 level. Samples were stored frozen at -80 degrees Celsius until use for this study. Circulating omentin levels were quantified using commercially available enzyme-linked immunosorbent assay (ELISA) kits. The results showed that 24 patients experienced a rise in CA-125 level during the postoperative period and 12 of these patients had an associated decrease in serum omentin level (average = 127.8 ng/mL). A significant negative correlation between omentin and CA-125 levels was observed (p = 0.02). This study provides the first evidence that omentin may be a clinically useful adjunct to CA-125 in detecting recurrent ovarian cancer and warrants further investigation. Citation Format: Kelsey Lewis, Chi Lam Au Yeung, Samuel Mok, Karen Lu. Omentin as an adjunct to CA-125 in detecting recurrent ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4661. doi:10.1158/1538-7445.AM2017-4661