Lipocalin2 as a plasma marker for tumors with hypoxic regions

Melanoma extracellular vesicles membrane coated nanoparticles as targeted delivery carriers for tumor and lungs

Targeting is the most challenging problem to solve for drug delivery systems. Despite the use of targeting units such as antibodies, peptides and proteins to increase their penetration in tumors the amount of therapeutics that reach the target is very small, even with the use of nanoparticles (NPs). Nature has solved the selectivity problem using a combination of proteins and lipids that are exposed on the cell membranes and are able to recognize specific tissues as demonstrated by cancer metastasis. Extracellular vesicles (EVs) have a similar ability in target only certain organs or to return to their original cells, showing home behavior. Here we report a strategy inspired by nature, using a combination of NPs and the targeting cell membranes of EVs. We implement the EV membranes, extracted by the EVs produced by melanoma B16-BL6 cells, as a coating of organosilica porous particles with the aim of targeting tumors and lung metastasis, while avoiding systemic effects and accumulation of the NPs in undesired organs. The tissue-specific fingerprint provided by the EVs-derived membranes from melanoma cells provides preferential uptake into the tumor and selective targeting of lungs. The ability of the EVs hybrid systems to behave as the natural EVs was demonstrated in vitro and in vivo in two different tumor models. As a proof of concept, the loading and release of doxorubicin, was investigated and its accumulation demonstrated in the expected tissues.

Lipocalin 2 (LCN2) confers acquired resistance to almonertinib in NSCLC through LCN2-MMP-9 signaling pathway

Almonertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is highly selective for EGFR-activating mutations as well as the EGFR T790M mutation in patients with advanced non-small cell lung cancer (NSCLC). However, the development of resistance inevitably occurs and poses a major obstacle to the clinical efficacy of almonertinib. Therefore, a clear understanding of the mechanism is of great significance to overcome drug resistance to almonertinib in the future. In this study, NCI-H1975 cell lines resistant to almonertinib (NCI-H1975 AR) were developed by concentration-increasing induction and were employed for clarification of underlying mechanisms of acquired resistance. Through RNA-seq analysis, the HIF-1 and TGF-β signaling pathways were significantly enriched by gene set enrichment analysis. Lipocalin-2 (LCN2), as the core node in these two signaling pathways, were found to be positively correlated to almonertinib-resistance in NSCLC cells. The function of LCN2 in the drug resistance of almonertinib was investigated through knockdown and overexpression assays in vitro and in vivo. Moreover, matrix metalloproteinases-9 (MMP-9) was further identified as a critical downstream effector of LCN2 signaling, which is regulated via the LCN2-MMP-9 axis. Pharmacological inhibition of MMP-9 could overcome resistance to almonertinib, as evidenced in both in vitro and in vivo models. Our findings suggest that LCN2 was a crucial regulator for conferring almonertinib-resistance in NSCLC and demonstrate the potential utility of targeting the LCN2-MMP-9 axis for clinical treatment of almonertinib-resistant lung adenocarcinoma.

Depletion of slow-cycling PDGFRα+ADAM12+ mesenchymal cells promotes antitumor immunity by restricting macrophage efferocytosis

The capacity to survive and thrive in conditions of limited resources and high inflammation is a major driver of tumor malignancy. Here we identified slow-cycling ADAM12+PDGFRα+ mesenchymal stromal cells (MSCs) induced at the tumor margins in mouse models of melanoma, pancreatic cancer and prostate cancer. Using inducible lineage tracing and transcriptomics, we demonstrated that metabolically altered ADAM12+ MSCs induced pathological angiogenesis and immunosuppression by promoting macrophage efferocytosis and polarization through overexpression of genes such as Gas6, Lgals3 and Csf1. Genetic depletion of ADAM12+ cells restored a functional tumor vasculature, reduced hypoxia and acidosis and normalized CAFs, inducing infiltration of effector T cells and growth inhibition of melanomas and pancreatic neuroendocrine cancer, in a process dependent on TGF-β. In human cancer, ADAM12 stratifies patients with high levels of hypoxia and innate resistance mechanisms, as well as factors associated with a poor prognosis and drug resistance such as AXL. Altogether, our data show that depletion of tumor-induced slow-cycling PDGFRα+ MSCs through ADAM12 restores antitumor immunity.

Biosynthesis of vanillic acid by Ochrobactrum anthropi and its applications

Vanillic acid has always been in high-demand in pharmaceutical, cosmetic, food, flavor, alcohol and polymer industries. Present study achieved highly pure synthesis of vanillic acid from vanillin using whole cells of Ochrobactrum anthropi strain T5_1. The complete biotransformation of vanillin (2 g/L) in to vanillic acid (2.2 g/L) with 95 % yield was achieved in single step in 7 h, whereas 5 g/L vanillin was converted to vanillic acid in 31 h. The vanillic acid thus produced was validated using LC-MS, GC-MS, FTIR and NMR. Further, vanillic acid was evaluated for in vitro anti-tyrosinase and cytotoxic properties on B16F1 skin cell line in dose dependent manner with IC₅₀ values of 15.84 mM and 9.24 mM respectively. The in silico Swiss target study predicted carbonic acid anhydrase IX and XII as key targets of vanillic acid inside the B16F1 skin cell line and revealed the possible mechanism underlying cell toxicity. Molecular docking indicated a strong linkage between vanillic acid and tyrosinase through four hydrogen and several hydrophobic bonds, with ΔG of -3.36 kJ/mol and Ki of 3.46 mM. The bioavailability of vanillic acid was confirmed by the Swiss ADME study with no violation of Lipinski's five rules.

Tocopheryl Phosphate Inhibits Rheumatoid Arthritis-Related Gene Expression In Vitro and Ameliorates Arthritic Symptoms in Mice

Anti-rheumatoid arthritis (RA) effects of α-tocopherol (α-T) have been shown in human patients in a double-blind trial. However, the effects of α-T and its derivatives on fibroblast-like synoviocytes (FLS) during the pathogenesis of RA remain unclear. In the present study, we compared the expression levels of genes related to RA progression in FLS treated with α-T, succinic ester of α-T (TS), and phosphate ester of α-T (TP), as determined via RT-PCR. The mRNA levels of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), matrix metalloproteinase (MMP)-3, and MMP-13 were reduced by treatment with TP without cytotoxicity, while α-T and TS did not show such effects. Furthermore, intraperitoneal injection of TP ameliorated the edema of the foot and joint and improved the arthritis score in laminarin-induced RA model mice. Therefore, TP exerted anti-RA effects through by inhibiting RA-related gene expression.

LCN2 Is a Potential Biomarker for Radioresistance and Recurrence in Nasopharyngeal Carcinoma

Background

Radioresistance-induced local failure, which can result in residual or recurrent tumors, remains one of the major causes of treatment failure in nasopharyngeal carcinoma (NPC). Lipocalin 2 (LCN2) is known to play important roles in cancer initiation, progression, and treatment responses. However, its role in the radioresistance of NPC remains unclear.

Methods

Microarray data from the Gene Expression Omnibus (GEO) was screened for candidate biomarkers relating to the radioresistance of NPC. The expression of LCN2 in NPC cell lines was verified by quantitative real-time PCR (RT-qPCR) and western blotting. The effects of knockdown or overexpression of LCN2 on NPC radiosensitivity were examined using a soft agar colony formation assay and a γH2AX assay. LCN2 expression in NPC specimens was evaluated by immunohistochemistry. Survival outcomes were analyzed. A possible correlation between LCN2 and hypoxia-inducible factor 1-alpha (HIF-1A) was examined by western blotting and a tissue microarray.

Results

LCN2 was highly expressed in the radioresistant NPC cell line CNE2R. Knocking down LCN2 enhanced the radiosensitivity of NPC cells by impairing their ability to repair DNA damage or proliferate, while ectopic expression of LCN2 conferred additional radioresistance to NPC cells. Immunohistochemical analysis of 100 NPC specimens revealed that LCN2 expression was significantly upregulated in radioresistant NPC tissues and was associated with NPC recurrence. Furthermore, a significant correlation between the expression of LCN2 and HIF-1A was detected.

Conclusion

LCN2 is associated with radioresistance and recurrence in NPC and may facilitate the development of a radioresistant phenotype through interacting with HIF-1A. Our data indicate that LCN2 is a promising target for predicting and overcoming radioresistance in NPC.

Elevated plasma level of neutrophil gelatinase-associated lipocalin (NGAL) in patients with breast cancer

Background: Neutrophil gelatinase‑associated lipocalin (NGAL), also known as lipocalin 2, siderocalin, 24p3 or uterocalin, plays a key role in inflammation and in different types of cancer. In this study, we investigated whether plasma NGAL levels were altered in patients with breast cancer. The relationship between plasma NGAL levels and pretreatment hematologic profile was also explored. Methods: Plasma NGAL concentrations were measured using ELISA in breast cancer patients and control subjects. A total of 75 patients with breast cancer and 65 age- and body mass index-matched control subjects were studied. All of the study subjects were female. Results: Plasma NGAL level was found to be elevated in the patients with breast cancer compared to the control subjects (94.3 ng/mL (interquartile range 39.3-207.6) vs. 55.0 ng/mL (interquartile range 25.8-124.7), p = 0.007). Multiple logistic regression analysis revealed that NGAL was independently associated with breast cancer, even after adjusting for known biomarkers. Furthermore, NGAL level was elevated in the breast cancer patients who were negative progesterone receptor status, had a histologic grade ≥ 2, clinical stage III, and pathologic stage T2+T3+T4. In addition, NGAL level was significantly correlated with white blood cell (WBC) count, monocyte count, neutrophil count, and platelet count (all p < 0.01). Moreover, WBC count, neutrophil count, monocyte count, lymphocyte count, platelet count, and NGAL level gradually increased as the stage progressed. Conclusions: Increased plasma NGAL levels were associated with breast cancer independently of risk factors, and were correlated with inflammatory biomarkers. These results suggest that NGAL may act through inflammatory reactions to play an important role in the pathogenesis of breast cancer.

White matter T2 hyperintensities and blood-brain barrier disruption in the hyperacute stage of subarachnoid hemorrhage in male mice: The role of lipocalin-2

AIMS

The current study examined whether white matter injury occurs in the hyperacute (4 hours) phase after subarachnoid hemorrhage (SAH) and the potential role of blood-brain barrier (BBB) disruption and an acute phase protein, lipocalin 2 (LCN2), in that injury.

METHODS

Subarachnoid hemorrhage was induced by endovascular perforation in adult mice. First, wild-type (WT) mice underwent MRI 4 hours after SAH to detect white matter T2 hyperintensities. Second, changes in LCN2 expression and BBB disruption associated with the MRI findings were examined. Third, SAH-induced white matter injury at 4 hours was compared in WT and LCN2 knockout (LCN2 KO) mice.

RESULTS

At 4 hours, most animals had uni- or bilateral white matter T2 hyperintensities after SAH in WT mice that were associated with BBB disruption and LCN2 upregulation. However, some disruption and LCN2 upregulation was also found in mice with no T2-hyperintensity lesion. In contrast, there were no white matter T2 hyperintensities in LCN2 KO mice after SAH. LCN2 deficiency also attenuated BBB disruption, myelin damage, and oligodendrocyte loss.

CONCLUSIONS

Subarachnoid hemorrhage causes very early BBB disruption and LCN2 expression in white matter that is associated with and may precede T2 hyperintensities. LCN2 deletion attenuates MRI changes and pathological changes in white matter after SAH.

Hypoxia Induces Astrocyte-Derived Lipocalin-2 in Ischemic Stroke

Ischemic stroke causes rapid hypoxic damage to the core neural tissue which is followed by graded chronological tissue degeneration in the peri-infarct zone. The latter process is mainly triggered by neuroinflammation, activation of inflammasomes, proinflammatory cytokines, and pyroptosis. Besides microglia, astrocytes play an important role in the fine-tuning of the inflammatory network in the brain. Lipocalin-2 (LCN2) is involved in the control of innate immune responses, regulation of excess iron, and reactive oxygen production. In this study, we analyzed LCN2 expression in hypoxic rat brain tissue after ischemic stroke and in astrocyte cell cultures receiving standardized hypoxic treatment. Whereas no LCN2-positive cells were seen in sham animals, the number of LCN2-positive cells (mainly astrocytes) was significantly increased after stroke. In vitro studies with hypoxic cultured astroglia revealed that LCN2 expression is significantly increased after only 2 h, then further increased, followed by a stepwise decline. The expression pattern of several proinflammatory cytokines mainly followed that profile in wild type (WT) but not in cultured LCN2-deficient astrocytes. Our data revealed that astrocytes are an important source of LCN2 in the peri-infarct region under hypoxic conditions. However, we must also stress that brain-intrinsic LCN2 after the initial hypoxia period might come from other sources such as invaded immune cells and peripheral organs via blood circulation. In any case, secreted LCN2 might have an influence on peripheral organ functions and the innate immune system during brain hypoxia.

Up-regulated lipocalin-2 in pediatric thyroid cancer correlated with poor clinical characteristics

BACKGROUND

The incidence of thyroid cancer is fast increasing in both adults and children. The pediatric thyroid cancer had often already progressed to a more advanced stage of the disease at diagnosis. Early detection of pediatric thyroid cancer has been a problem for many years. Lipocalin-2 (Lcn2) has been reported to be over-expressed in cancers of diverse histological origin and it facilitates tumorigenesis by promoting survival, growth, and metastasis.

METHODS

The plasma Lcn2 concentration of 28 Chinese papillary thyroid cancer (PTC) children and 24 healthy controls was measured. Immunostaining for Ki-67 of tumor tissue from PTC children was performed. The expression levels of Lcn2 and NFκB in PTC tissue and peri-carcinoma tissue of PTC children were measured through Western blot.

RESULTS

The plasma concentration of Lcn2 was significantly elevated in pediatric PTC patients compared with healthy controls. Besides, the plasma Lcn2 concentration significantly correlated with clinical characteristics, NFκB level, and Ki-67 positive rate of nucleus in tissue of PTC.

CONCLUSION

This is the first study to evaluate the plasma Lcn2 in pediatric PTC patients. It is possible that the plasma Lcn2 may be a new biomarker of pediatric thyroid cancer. Further studies are needed to explore the definite role and mechanism of Lcn2 in thyroid cancer, which will help to explore novel diagnostic or therapeutic strategies.

Lack of adrenomedullin in mouse endothelial cells results in defective angiogenesis, enhanced vascular permeability, less metastasis, and more brain damage

Adrenomedullin (AM) is a vasodilating peptide involved in the regulation of circulatory homeostasis and in the pathophysiology of certain cardiovascular diseases. AM plays critical roles in blood vessels, including regulation of vascular stability and permeability. To elucidate the autocrine/paracrine function of AM in endothelial cells (EC) in vivo, a conditional knockout of AM in EC (AM(EC-KO)) was used. The amount of vascularization of the matrigel implants was lower in AM(EC-KO) mice indicating a defective angiogenesis. Moreover, ablation of AM in EC revealed increased vascular permeability in comparison with wild type (WT) littermates. In addition, AM(EC-KO) lungs exhibited significantly less tumor growth than littermate WT mice using a syngeneic model of metastasis. Furthermore, following middle cerebral artery permanent occlusion, there was a significant infarct size decrease in animals lacking endothelial AM when compared to their WT counterparts. AM is an important regulator of EC function, angiogenesis, tumorigenesis, and brain response to ischemia. Studies of AM should bring novel approaches to the treatment of vascular diseases.

Epigenetic induction of epithelial to mesenchymal transition by LCN2 mediates metastasis and tumorigenesis, which is abrogated by NF-κB inhibitor BRM270 in a xenograft model of lung adenocarcinoma

Tumor initiating cancer stem-like cells (TICSCs) have recently become the object of intensive study. Human-Lipocalin-2 (hLCN2) acts as a biomarker for cancers. The aim of the present study was to explore new insights regarding the potential role of LCN2 in inducing epithelial to mesenchymal transition (EMT) by transfecting LCN2 into CD133+-A549-TICSCs and its cross-talk with the NF-κB signaling pathway in adenocarcinoma of the lung. Furthermore, EMT was confirmed by transcriptomic analysis, immunoblotting and immunocyto/histochemical analyses. Tumorigenesis and metastasis were confirmed by molecular therapeutics tracer 2DG infrared optical probe in BALB/cSIc-nude mice. It was observed that the CD133+-expressing-LCN2-A549 TICSCs population increased in adenocarcinoma of the lung compared to the normal lung tissue. The expressions of genes involved in stemness, adhesion, motility and drug efflux was higher in these cells than in their non-LCN2 expressing counterparts. The present study revealed that elevated expression of LCN2 significantly induced metastasis via EMT. Overexpression of LCN2 significantly increased stemness and tumor metastasis by modulating NF-κB cellular signaling. BRM270, a novel inhibitor of NF-κB plays a significant role in the EMT reversal. BRM270, a naturaceutical induces cell shrinkage, karyorrhexis and programmed cell death (PCD) which were observed by Hoechst 33342 staining while flow cytometry analysis showed significant (P<0.05) decrease in cell population from G0-G1 phases. Also, 2DG guided in vivo model revealed that BRRM270 significantly (P<0.0003) reduced tumor metastasis and increased percent survival in real-time with complete resection. An elaborate study on the novel concept with respect to linking of naturaceutics as selective and potential anticancer agent that eliminates the elevated LCN2 induced EMT and tumor dissemination through cooperation with the NF-κB signaling as the baseline data for the planning of new therapeutic strategies was conducted for the first time. Our results also illustrate a molecular mechanistic approach for 2DG-guided molecular imaging-based cancer therapy using BRM270 as a novel cancer therapeutic drug to enhance the effect of doxorubicin (Dox)-resistant LCN2 induced metastasis of solid tumors in nude mice.