Over-expression of low-density lipoprotein receptor-related Protein-1 is associated with poor prognosis and invasion in pancreatic ductal adenocarcinoma

LRP1 as a promising therapeutic target for gastrointestinal tumors: Inhibiting proliferation, invasion and migration of cancer cells

Gastrointestinal (GI) cancers are the most common types of tumors worldwide. The lack of cancer biomarkers and targeted drug resistance are barriers to achieving effective cancer therapy. Low-density lipoprotein receptor-related protein 1 (LRP1) is a transmembrane protein that has multiple functions due to its ability to recognize different ligands; however, the role of LRP1 in GI cancer cells remains unclear. The present study aimed to investigate the role of LRP1 in GI tumors. The Cancer Genome Atlas database was used to analyze the potential correlation between expression of LRP1 and prognosis in patients with GI cancer. Bioinformatics analysis was utilized and the expression of LRP1 was simultaneously validated in GI cancer at the cellular level through western blot experiments. LRP1 was expressed at high levels in HGC-27, HepG2 and BxPC-3 cells. LRP1 expression in GI cancer cells was knocked down using lentivirus-mediated shRNA and the effects on biological functions were observed. LRP1 knockdown suppressed the proliferation, invasion and migration of GI cancer cells. LRP1 knockdown inhibited CD36 gene expression in HepG2 and BxPC-3 cells. LRP1 knockdown inhibited the proliferation, invasion and migration of GI cancer cells, suggesting that LRP1 may be a novel target for treatment of GI tumors.

Obesity-induced changes in cancer cells and their microenvironment: Mechanisms and therapeutic perspectives to manage dysregulated lipid metabolism

Obesity has been closely related to cancer progression, recurrence, metastasis, and treatment resistance. We aim to review recent progress in the knowledge on the obese macroenvironment and the generated adipose tumor microenvironment (TME) inducing lipid metabolic dysregulation and their influence on carcinogenic processes. Visceral white adipose tissue expansion during obesity exerts systemic or macroenvironmental effects on tumor initiation, growth, and invasion by promoting inflammation, hyperinsulinemia, growth-factor release, and dyslipidemia. The dynamic relationship between cancer and stromal cells of the obese adipose TME is critical for cancer cell survival and proliferation as well. Experimental evidence shows that secreted paracrine signals from cancer cells can induce lipolysis in cancer-associated adipocytes, causing them to release free fatty acids and acquire a fibroblast-like phenotype. Such adipocyte delipidation and phenotypic change is accompanied by an increased secretion of cytokines by cancer-associated adipocytes and tumor-associated macrophages in the TME. Mechanistically, the availability of adipose TME free fatty acids and tumorigenic cytokines concomitant with the activation of angiogenic processes creates an environment that favors a shift in the cancer cells toward an aggressive phenotype associated with increased invasiveness. We conclude that restoring the aberrant metabolic alterations in the host macroenvironment and in adipose TME of obese subjects would be a therapeutic option to prevent cancer development. Several dietary, lipid-based, and oral antidiabetic pharmacological therapies could potentially prevent tumorigenic processes associated with the dysregulated lipid metabolism closely linked to obesity.

Alleviation of cognitive deficits in a rat model of glutamate-induced excitotoxicity, using an N-type voltage-gated calcium channel ligand, extracted from Agelena labyrinthica crude venom

Excitotoxicity is a common pathological process in Alzheimer's disease (AD) which is caused by the over-activity of N-Methyl-D-Aspartate receptors (NMDARs). The release of neurotransmitters depends on the activity of voltage-gated calcium channels (VGCCs). Hyper-stimulation of NMDARs can enhance the releasement of neurotransmitters through the VGCCs. This malfunction of channels can be blocked by selective and potent N-type VGCCs ligand. Under excitotoxicity condition, glutamate has negative effects on the pyramidal cells of the hippocampus, which ends in synaptic loss and elimination of these cells. These events leads to learning and memory elimination through the hippocampus circuit's dysfunction. A suitable ligand has a high affinity to receptor or channel and is selective for its target. The bioactive small proteins of venom have these characteristics. Therefore, peptides and small proteins of animal venom are precious sources for pharmacological applications. The omega-agatoxin-Aa2a was purified, and identified from Agelena labyrinthica specimens, as an N-type VGCCs ligand for this study. The effect of the omega-agatoxin-Aa2a on the glutamate-induced excitotoxicity in rats was evaluated through behavioral tests including Morris Water Maze, and Passive avoidance. The syntaxin1A (SY1A), synaptotagmin1 (SYT1), and synaptophysin (SYN) genes expression were measured via Real-Time PCR. The local expression of synaptosomal-associated protein, 25 k Da (SNAP-25) was visualized using an immunofluorescence assay for synaptic quantification. Electrophysiological amplitude of field excitatory postsynaptic potentials (fEPSPs) in the input-output and LTP curves of mossy fiber were recorded. The cresyl violet staining of hippocampus sections was performed for the groups. Our results demonstrated that the omega-agatoxin-Aa2a treatment could recover the learning, and memory impairment caused by NMDA-induced excitotoxicity in rat hippocampus.

Lipid Nanoparticles Delivering Constitutively Active STING mRNA to Stimulate Antitumor Immunity

Treating immunosuppressive tumors represents a major challenge in cancer therapies. Activation of STING signaling has shown remarkable potential to invigorate the immunologically "cold" tumor microenvironment (TME). However, we have shown that STING is silenced in many human cancers, including pancreatic ductal adenocarcinoma (PDAC) and Merkel cell carcinoma (MCC). In this study, we demonstrated that mRNA-lipid nanoparticle (LNP) technology could be used to efficiently deliver naturally occurring constitutively active STING mutant STING^R284S into these cancer cells to reactivate STING antitumor immunity and trigger robust killing of tumor cells. STING agonists are being actively pursued as cancer immunotherapies. However, traditional STING agonists can induce T cell cytotoxicity, counteracting the desired antitumor immune response. In addition, the antitumor efficacy of traditional STING agonists obligatorily depends on STING expression and does not work in STING-silenced cancers. Importantly, we found that STING^R284S mRNA-LNP does not introduce T cell cytotoxicity. Our studies demonstrated that mRNA-LNP delivery of STING^R284S can reactivate the antitumor response without introducing antiproliferative effects in lymphocytic immune cells, overcoming the toxicity and limitations of conventional STING agonists. Our work therefore identifies a novel therapeutic tool for reactivating antitumor immunity in an array of STING-silenced immunologically "cold" tumors that are refractory to current therapies.

Elevated expression of cholesterol transporter LRP-1 is crucially implicated in the pathobiology of glioblastoma

Glioblastoma (GBM) is the most common primary malignant brain tumor with a grave prognosis. The present study evaluated the expression of Cholesterol transporter [importer -Lipoprotein Receptor-related Protein-1 (LRP-1) and exporter -ATP-binding cassette transporters-1 (ABCA-1)] in GBM and their implications in tumor-biology, clinical outcome and therapeutic potentials. The mRNA and protein expression was assessed by qRT-PCR and immunohistochemistry, respectively, in 85 GBMs. For comparison, 25 lower-grade astrocytomas (IDH-mutant, grade-2/3) [LGA] 16 cases of high-grade astrocytomas (IDH-mutant, grade-4) [HGA] were also evaluated. In-vitro analysis was performed on U87MG and LN229 glioma cell line. The expression of LRP-1 (mRNA and protein) was significantly higher in GBM than LGA, HGA and normal brain (NB) [p-values 0.007, 0.003 and <0.001 for mRNA; 0.024, <0.001 and <0.001 for immunohistochemistry]. Majority of the GBMs (82.4%) showed strong immunoreactivity for LRP-1, and all tumor cases were positive while the normal brain was negative. LRP-1 immunoreactivity positively correlated with the MIB-1 labeling index (p-value-0.013). LRP-1 knockdown in-vitro was associated with decreased cell survival, proliferation, migration, invasion, and increased apoptosis. Similar effect was also demonstrated by Receptor Associated Protein (RAP), a LRP-1 inhibitory drug. The silencing of LRP-1 was also associated with decreased cholesterol level. The ABCA-1 expression was higher in GBM than LGA and NB (p-value 0.011 and <0.001), however there was no significant association with other parameters. LRP-1 showed a positive correlation with ABCA-1 and associated with decreased expression with LRP-1 knock-down in-vitro. The expression of LRP-1 and ABCA-1 didn't correlate with overall survival in GBMs. Hence, LRP-1 is crucial for the tumor cells' survival and aggressive biological behavior which is maintain through the regulation of high intracellular cholesterol import. Its expression is significantly higher in GBMs and also implicated in the regulation of ABCA-1 expression. Considering its immune-positivity only in the neoplastic cell and strong positivity in GBM it may be a useful adjunct to the diagnosis. For the first time, the present study emphasized its role as a potential therapeutic target in the form of RAP which is presently being used in other neurological diseases under clinical trials.

Secreted HSP90α-LRP1 Signaling Promotes Tumor Metastasis and Chemoresistance in Pancreatic Cancer

The extracellular heat shock protein 90α (eHSP90α) has been reported to promote cancer cell motility. However, whether pancreatic cancer (PC) cells expressed membrane-bound or secreted HSP90α, as well as its underlying mechanism for PC progression, were still unclear. Our study demonstrated that the amounts of secreted HSP90α proteins were discrepant in multiple PC cells. In addition, highly invasive Capan-2 cells have a higher level of secreted HSP90α compared with those of less invasive PL45 cells. The conditioned medium of Capan-2 cells or recombinant HSP90α treatment stimulated the migration and invasion of PC cells, which could be prevented with a neutralizing anti-HSP90α antibody. Furthermore, secreted HSP90α promoted elements of epithelial-mesenchymal transition in PL45 cells, including increases in vimentin and Snail expressions, decreases in E-cadherin expression, and changes in cell shape towards a mesenchymal phenotype, but these phenomena were reversed by the anti-HSP90α antibody in Capan-2 cells. In addition, high levels of low-density lipoprotein receptor-related protein 1 (LRP1) were associated with worsened patient survival in pancreatic adenocarcinoma. We demonstrated LRP1 as a receptor of eHSP90α for its stimulatory role in metastasis, by activating the AKT pathway. In addition, silencing LRP1 enhanced the chemosensitivity to gemcitabine and doxorubicin in Capan-2 cells. Therefore, our study indicated that blocking secreted HSP90α underlies an aspect of metastasis and chemoresistance in PC.

Antiinfective properties of ursolic acid-loaded chitosan nanoparticles against Staphylococcus aureus

The present study aimed to synthesize ursolic acid-loaded chitosan nanoparticles (UA-Ch-NPs) as an antiinfective agent against 21 Staphylococcus aureus isolates. The UA-Ch-NPs were synthesized by a simple method and then characterized by TEM, FTIR, DLS-zeta potential, and XRD analyses. According to the characterization results, highly dispersed spherical nanoparticles with a mean diameter of 258 nm and a zeta potential of + 40.1 mV were developed. The antibacterial properties of UA-Ch-NPs were investigated and their inhibitory effect on biofilm formation was demonstrated by AFM. Finally, the expression levels of icaA and icaD were measured using real-time PCR. Results indicated that the minimum inhibitory concentration (MIC) of UA and UA-Ch-NPs against S. aureus was 64 and 32 µg/mL, respectively. The treatment of bacterial cells with UA-Ch-NPs significantly decreased the expression of icaA and icaD genes which are engaged in biofilm formation. Our results indicated that UA-Ch-NPs could be a promising material for antibacterial and antibiofilm applications.

Cellular and molecular mechanisms of perineural invasion of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignant disease with a unique tumor microenvironment surrounded by an interlaced network of cancer and noncancerous cells. Recent works have revealed that the dynamic interaction between cancer cells and neuronal cells leads to perineural invasion (PNI), a clinical pathological feature of PDAC. The formation and function of PNI are dually regulated by molecular (e.g., involving neurotrophins, cytokines, chemokines, and neurotransmitters), metabolic (e.g., serine metabolism), and cellular mechanisms (e.g., involving Schwann cells, stromal cells, T cells, and macrophages). Such integrated mechanisms of PNI not only support tumor development, growth, invasion, and metastasis but also mediate the formation of pain, all of which are closely related to poor disease prognosis in PDAC. This review details the modulation, signaling pathways, detection, and clinical relevance of PNI and highlights the opportunities for further exploration that may benefit PDAC patients.

Purification of Soluble Membrane-Bound Ambystoma mexicanum Epidermal Lipoxygenase from E. coli and Its Growth Effect on Human Fetal Foreskin Fibroblast

Lipoxygenases are non-heme iron-containing lipid dioxygenases enzymes that catalyze the hydroperoxidation of lipids. The Mexican axolotl (Ambystoma mexicanum) is a prominent source of the enzyme with a regeneration capacity in limbs. It has been shown that transfected human osteosarcoma and keratinocyte cells with epidermal lipoxygenase (LOXe) have an increased rate of cell migration. In the present study, LOXe, a peripheral membrane protein, was produced in Escherichia coli. The enzyme was purified using different detergents, anionic solutions, and gel filtration chromatography. Kinetic assay of the enzyme activity was carried out by the spectroscopy method using arachidonic acid as a substrate. Finally, the enzyme was characterized and its growth effect on human fibroblast cells was examined by MTT viability assay. Enzyme kinetic parameters including K_m of 90.4 µM and V_max of 2.63 IU were determined for LOXe. The enzyme with 0.1 nM end concentration promoted the growth of 5000 cells/well human fibroblast cells up to 11% (P < 0.01). In the present study, we introduce an E. coli expression system to produce an excessive amount of soluble LOXe and the efficient purification method to provide a soluble and active form of LOXe that is effective in stimulating human fibroblast cell proliferation.

Insulin-like growth factor binding protein 3 chemosensitizes pancreatic ductal adenocarcinoma through its death receptor

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human malignancies. Gemcitabine and doxorubicin are commonly used as the chemotherapy agents, but most of PDAC tumors eventually acquired resistance to chemotherapy. Accumulating evidence indicates that Insulin-like growth factor binding protein 3 (IGFBP-3) plays a key role against tumor growth but its expression has commonly suppressed. The present study was designed to evaluate IGFBP-3 effects in chemotherapy sensitization of PDAC cells. Here, we report that the re-sensitization of chemoresistant PDAC cells was occurred by IGFBP-3 through recruitment of its death receptor (IGFBP-3R). Using gemcitabine, doxorubicin-resistant PDAC cell lines, we found that IGFBP-3 sensitized chemoresistant cells by activating apoptosis (as evaluated by Bax up-regulation, Bcl-2 down-regulation as well as Caspase-3 and Caspase 8 activation). IGFBP-3R was also found to have higher expression level in resistant AsPc-1 and MIA PaCa-2 cells in comparison to parental cells. IGFBP-3R was also highly expressed in PDAC tumor which exposed to chemotherapy in comparison to un-treated PDAC tumors. In addition, we confirmed our finding by using specific siRNA to knocking down of IGFBP-3R which prevents IGFBP-3 Chemosensitization. Taken together, the present study for the first time indicates the clinical relevance for combining IGFBP-3 with chemotherapy to reduce chemoresistance in PDAC.

LRP-1 Promotes Colon Cancer Cell Proliferation in 3D Collagen Matrices by Mediating DDR1 Endocytosis

Low density lipoprotein receptor related protein-1 (LRP-1) is a large ubiquitous endocytic receptor mediating the clearance of various molecules from the extracellular matrix. Several studies have shown that LRP-1 plays crucial roles during tumorigenesis functioning as a main signal pathway regulator, especially by interacting with other cell-surface receptors. Discoïdin Domain Receptors (DDRs), type I collagen receptors with tyrosine kinase activity, have previously been associated with tumor invasion and aggressiveness in diverse tumor environments. Here, we addressed whether it could exist functional interplays between LRP-1 and DDR1 to control colon carcinoma cell behavior in three-dimensional (3D) collagen matrices. We found that LRP-1 established tight molecular connections with DDR1 at the plasma membrane in colon cancer cells. In this tumor context, we provide evidence that LRP-1 regulates by endocytosis the cell surface levels of DDR1 expression. The LRP-1 mediated endocytosis of DDR1 increased cell proliferation by promoting cell cycle progression into S phase and decreasing apoptosis. In this study, we identified a new molecular way that controls the cell-surface expression of DDR1 and consequently the colon carcinoma cell proliferation and apoptosis and highlighted an additional mechanism by which LRP-1 carries out its sensor activity of the tumor microenvironment.

A priority oriented nutrition education program to improve nutritional and cardiometabolic status in the workplace: a randomized field trial

Background

Workplace nutrition has been identified as a priority setting that can significantly reduce cardiovascular diseases (CVD) risk factors. This study was conducted as a part of the workplace education program to improve nutritional practices and cardiometabolic status in industrial personnel.

Methods

The present research was a randomized controlled field trial conducted on employees of a regional petrochemical company. The health-related priorities of the program were defined and addressed in the study in which 104 employees with dyslipidemia were randomly divided into two groups of education and control. Data were collected pre- and post-intervention, using valid and reliable multi-session questionnaires on demographic data, nutritional knowledge, and nutritional intake. Anthropometric measures, serum FBS, HbA1C, hs-CRP and homocysteine (Hcy) were assessed in both groups. In the education group, the nutrition program included five educational workshops about healthy nutrition and regular exercise along with educational messages over a 3-month period. The controls did not receive any education during the study.

Results

There were no statistically significant differences between the two groups regarding the baseline variables. The education group significantly improved their nutritional knowledge (p < 0.001), dietary intakes (p < 0.005), serum FBS (p < 0.001) and Hcy levels (p < 0.001) and anthropometric indices.

Conclusion

Workplace nutrition education programs can improve knowledge and reduce important CVD risk factors.

Pancreatic ductal adenocarcinoma: a radiomics nomogram outperforms clinical model and TNM staging for survival estimation after curative resection

OBJECTIVES

To identify a CT-based radiomics nomogram for survival prediction in patients with resected pancreatic ductal adenocarcinoma (PDAC).

METHODS

A total of 220 patients (training cohort n = 147; validation cohort n = 73) with PDAC were enrolled. A total of 300 radiomics features were extracted from CT images. And the least absolute shrinkage and selection operator algorithm were applied to select features and develop a radiomics score (Rad-score). The radiomics nomogram was constructed by multivariate regression analysis. Nomogram discrimination, calibration, and clinical usefulness were evaluated. The association of the Rad-score and recurrence pattern in PDAC was evaluated.

RESULTS

The Rad-score was significantly associated with PDAC patient's disease-free survival (DFS) and overall survival (OS) (both p < 0.001 in two cohorts). Incorporating the Rad-score into the radiomics nomogram resulted in better performance of the survival prediction than that of the clinical model and TNM staging system. In addition, the radiomics nomogram exhibited good discrimination, calibration, and clinical usefulness in both the training and validation cohorts. There was no association between the Rad-score and recurrence pattern.

CONCLUSIONS

The radiomics nomogram integrating the Rad-score and clinical data provided better prognostic prediction in resected PDAC patients, which may hold great potential for guiding personalized care for these patients. The Rad-score was not a predictor of the recurrence pattern in resected PDAC patients.

KEY POINTS

• The Rad-score developed by CT radiomics features was significantly associated with PDAC patients' prognosis. • The radiomics nomogram integrating the Rad-score and clinical data has value to permit non-invasive, low-cost, and personalized evaluation of prognosis in PDAC patients. • The radiomics nomogram outperformed clinical model and the TNM staging system in terms of survival estimation.