Integrative informatics analysis identifies that ginsenoside Re improves renal fibrosis through regulation of autophagy.

We previously demonstrated that ginsenoside Re (G-Re) has protective effects on acute kidney injury. However, the underlying mechanism is still unclear. In this study, we conducted a meta-analysis and pathway enrichment analysis of all published transcriptome data to identify differentially expressed genes (DEGs) and pathways of G-Re treatment. We then performed in vitro studies to measure the identified autophagy and fibrosis markers in HK2 cells. In vivo studies were conducted using ureteric obstruction (UUO) and aristolochic acid nephropathy (AAN) models to evaluate the effects of G-Re on autophagy and kidney fibrosis. Our informatics analysis identified autophagy-related pathways enriched for G-Re treatment. Treatment with G-Re in HK2 cells reduced autophagy and mRNA levels of profibrosis markers with TGF-ß stimulation. In addition, induction of autophagy with PP242 neutralized the anti-fibrotic effects of G-Re. In murine models with UUO and AAN, treatment with G-Re significantly improved renal function and reduced the upregulation of autophagy and profibrotic markers. A combination of informatics analysis and biological experiments confirmed that ginsenoside Re could improve renal fibrosis and kidney function through the regulation of autophagy. These findings provide important insights into the mechanisms of G-Re's protective effects in kidney injuries.

Site-Selective Polyfluoroaryl Modification and Unsymmetric Stapling of Unprotected Peptides.

Peptide stapling is recognized as an effective strategy for improving the proteolytic stability and cell permeability of peptides. In this study, we present a novel approach for the site-selective unsymmetric perfluoroaryl stapling of Ser and Cys residues in unprotected peptides. The stapling reaction proceeds smoothly under very mild conditions, exhibiting a remarkably rapid reaction rate. It can furnish stapled products in both liquid and solid phases, and the presence of nucleophilic groups other than Cys thiol within the peptide does not impede the reaction, resulting in uniformly high yields. Importantly, the chemoselective activation of Ser ß-C(sp3)-H enables the unreacted -OH to serve as a reactive handle for subsequent divergent modification of the staple moiety with various therapeutic functionalities, including a clickable azido group, a polar moiety, a lipid tag, and a fluorescent dye. In our study, we have also developed a visible-light-induced chemoselective C(sp3)-H polyfluoroarylation of the Ser ß-position. This reaction avoids interference with the competitive reaction of Ser -OH, enabling the precise late-stage polyfluoroarylative modification of Ser residues in various unprotected peptides containing other highly reactive amino acid residues. The biological assay suggested that our peptide stapling strategy would potentially enhance the proteolytic stability and cellular permeability of peptides.

Microcolin H, a novel autophagy inducer, exerts potent antitumour activity by targeting PITPα/ß.

The identification of effective drug targets and the development of bioactive molecules are areas of high need in cancer therapy. The phosphatidylinositol transfer protein alpha/beta isoform (PITPα/ß) has been reported to play an essential role in integrating phosphoinositide trafficking and lipid metabolism in diverse cellular processes but remains unexplored as a potential target for cancer treatment. Herein, data analysis of clinical cancer samples revealed that PITPα/ß expression is closely correlated with the poor prognosis. Target identification by chemical proteomic methods revealed that microcolin H, a naturally occurring marine lipopeptide, directly binds PITPα/ß and displays antiproliferative activity on different types of tumour cell lines. Furthermore, we identified that microcolin H treatment increased the conversion of LC3I to LC3II, accompanied by a reduction of the level of p62 in cancer cells, leading to autophagic cell death. Moreover, microcolin H showed preeminent antitumour efficacy in nude mouse subcutaneous tumour models with low toxicity. Our discoveries revealed that by targeting PITPα/ß, microcolin H induced autophagic cell death in tumours with efficient anti-proliferating activity, which sheds light on PITPα/ß as a promising therapeutic target for cancer treatment.

HCK induces macrophage activation to promote renal inflammation and fibrosis via suppression of autophagy.

Renal inflammation and fibrosis are the common pathways leading to progressive chronic kidney disease (CKD). We previously identified hematopoietic cell kinase (HCK) as upregulated in human chronic allograft injury promoting kidney fibrosis; however, the cellular source and molecular mechanisms are unclear. Here, using immunostaining and single cell sequencing data, we show that HCK expression is highly enriched in pro-inflammatory macrophages in diseased kidneys. HCK-knockout (KO) or HCK-inhibitor decreases macrophage M1-like pro-inflammatory polarization, proliferation, and migration in RAW264.7 cells and bone marrow-derived macrophages (BMDM). We identify an interaction between HCK and ATG2A and CBL, two autophagy-related proteins, inhibiting autophagy flux in macrophages. In vivo, both global or myeloid cell specific HCK-KO attenuates renal inflammation and fibrosis with reduces macrophage numbers, pro-inflammatory polarization and migration into unilateral ureteral obstruction (UUO) kidneys and unilateral ischemia reperfusion injury (IRI) models. Finally, we developed a selective boron containing HCK inhibitor which can reduce macrophage pro-inflammatory activity, proliferation, and migration in vitro, and attenuate kidney fibrosis in the UUO mice. The current study elucidates mechanisms downstream of HCK regulating macrophage activation and polarization via autophagy in CKD and identifies that selective HCK inhibitors could be potentially developed as a new therapy for renal fibrosis.

Neurokinin-1 receptor drives PKCɑ-AURKA/N-Myc signaling to facilitate the neuroendocrine progression of prostate cancer.

The widespread application of antiandrogen therapies has aroused a significant increase in the incidence of NEPC, a lethal form of the disease lacking efficient clinical treatments. Here we identified a cell surface receptor neurokinin-1 (NK1R) as a clinically relevant driver of treatment-related NEPC (tNEPC). NK1R expression increased in prostate cancer patients, particularly higher in metastatic prostate cancer and treatment-related NEPC, implying a relation with the progression from primary luminal adenocarcinoma toward NEPC. High NK1R level was clinically correlated with accelerated tumor recurrence and poor survival. Mechanical studies identified a regulatory element in the NK1R gene transcription ending region that was recognized by AR. AR inhibition enhanced the expression of NK1R, which mediated the PKCα-AURKA/N-Myc pathway in prostate cancer cells. Functional assays demonstrated that activation of NK1R promoted the NE transdifferentiation, cell proliferation, invasion, and enzalutamide resistance in prostate cancer cells. Targeting NK1R abrogated the NE transdifferentiation process and tumorigenicity in vitro and in vivo. These findings collectively characterized the role of NK1R in tNEPC progression and suggested NK1R as a potential therapeutic target.

NaClO-Mediated Cross Installation of Indoles and Azoles Benefits Anticancer Hit Discovery.

Innovations in synthetic chemistry have a profound impact on the drug discovery process, and will always be a necessary driver of drug development. As a result, it is of significance to develop novel simple and effective synthetic installation of medicinal modules to promote drug discovery. Herein, we have developed a NaClO-mediated cross installation of indoles and azoles, both of which are frequently encountered in drugs and natural products. This effective toolbox provides a convenient synthetic route to access a library of N-linked 2-(azol-1-yl) indole derivatives, and can be used for late-stage modification of drugs, natural products and peptides. Moreover, biological screening of the library has revealed that several adducts showed promising anticancer activities against A549 and NCI-H1975 cells, which give us a hit for anticancer drug discovery.

Neurokinin-1 receptor promotes non-small cell lung cancer progression through transactivation of EGFR.

Despite the great advances in target therapy, lung cancer remains the top cause of cancer-related death worldwide. G protein-coupled receptor neurokinin-1 (NK1R) is shown to play multiple roles in various cancers; however, the pathological roles and clinical implication in lung cancer are unclarified. Here we identified NK1R as a significantly upregulated GPCR in the transcriptome and tissue array of human lung cancer samples, associated with advanced clinical stages and poor prognosis. Notably, NK1R is co-expressed with epidermal growth factor receptor (EGFR) in NSCLC patients' tissues and co-localized in the tumor cells. NK1R can crosstalk with EGFR by interacting with EGFR, transactivating EGFR phosphorylation and regulating the intracellular signaling of ERK1/2 and Akt. Activation of NK1R promotes the proliferation, colony formation, EMT, MMP2/14 expression, and migration of lung cancer cells. The inhibition of NK1R by selective antagonist aprepitant repressed cell proliferation and migration in vitro. Knockdown of NK1R significantly slowed down the tumor growth in nude mice. The sensitivity of lung cancer cells to gefitinib/osimertinib is highly increased in the presence of the selective NK1R antagonist aprepitant. Our data suggest that NK1R plays an important role in lung cancer development through EGFR signaling and the crosstalk between NK1R and EGFR may provide a potential therapeutic target for lung cancer treatment.

Inhibition of autophagy by YC-1 promotes gefitinib induced apoptosis by targeting FOXO1 in gefitinib-resistant NSCLC cells.

Non-small cell lung cancer (NSCLC) is the most common cancer in the world. Gefitinib, an inhibitor of EGFR tyrosine kinase, is highly effective in treating NSCLC patients with activating EGFR mutations (L858R or Ex19del). However, despite excellent disease control with gefitinib therapy, innate resistance and inevitable acquired resistance represent immense challenges in NSCLC therapy. Gefitinib potently induces cytoprotective autophagy, which has been implied to contribute to both innate and acquired resistance to gefitinib in NSCLC cells. Currently, abrogation of autophagy is considered a promising strategy for NSCLC therapy. In the present study, YC-1, an inhibitor of HIF-1α, was first found to significantly inhibit the autophagy induced by gefitinib by disrupting the fusion of autophagosomes and lysosomes and thereby enhancing the proapoptotic effect of gefitinib in gefitinib-resistant NSCLC cells. Furthermore, the combinational anti-autophagic and pro-apoptotic effect of gefitinib and YC-1 was demonstrated to be associated with an enhanced of forkhead box protein O1 (FOXO1) transcriptional activity which resulted from an increase in the p-FOXO1 protein level in gefitinib-resistant NSCLC cells. Our data suggest that inhibition of autophagy by targeting FOXO1 may be a feasible therapeutic strategy to overcome both innate and acquired resistance to EGFR-TKIs.

The antimicrobial peptide YD attenuates inflammation via miR-155 targeting CASP12 during liver fibrosis.

The antimicrobial peptide APKGVQGPNG (named YD), a natural peptide originating from Bacillus amyloliquefaciens CBSYD1, exhibited excellent antibacterial and antioxidant properties in vitro. These characteristics are closely related to inflammatory responses which is the central trigger for liver fibrosis. However, the therapeutic effects of YD against hepatic fibrosis and the underlying mechanisms are rarely studied. In this study, we show that YD improved liver function and inhibited the progression of liver fibrosis by measuring the serum transaminase activity and the expression of α-smooth muscle actin and collagen I in carbon tetrachloride-induced mice. Then we found that YD inhibited the level of miR-155, which plays an important role in inflammation and liver fibrosis. Bioinformatics analysis and luciferase reporter assay indicate that Casp12 is a new target of miR-155. We demonstrate that YD significantly decreases the contents of inflammatory cytokines and suppresses the NF-κB signaling pathway. Further studies show that transfection of the miR-155 mimic in RAW264.7 cells partially reversed the YD-mediated CASP12 upregulation, the downregulated levels of inflammatory cytokines, and the inactivation of the NF-κB pathways. Collectively, our study indicates that YD reduces inflammation through the miR-155-Casp12-NF-κB axis during liver fibrosis and provides a promising therapeutic candidate for hepatic fibrosis.

CPF-C1 analog with effective antimicrobial and antibiofilm activities against Staphylococcus aureus including MRSA.

The evolution of Staphylococcus aureus (S. aureus) with the ability to acquire and develop resistance to antibiotics has been described as a distinct strain emergence event. Methicillin-resistant S. aureus (MRSA) is responsible for most global S. aureus bacteremia cases. Bacterial biofilms are one of the primary reasons for drug resistance. Biofilms formed by S. aureus are the most common cause of biofilm-associated infections, which increase the difficulty of treatment. Antimicrobial peptides (AMPs) represent promising candidates for the future treatment of antibiotic-resistant bacterial and biofilm-associated infections. In this study, we designed and synthesized a series of analogs to increase the druggability of the natural antimicrobial peptide CPF-C1. Among the analogs, CPF-2 showed high antimicrobial activity against MRSA and multidrug-resistant S. aureus isolated from clinics. In the serum and physiological salt environment, CPF-2 also exhibited effective antimicrobial activity. Importantly, CPF-2 did not determine resistance and showed no hemolytic activity at the active concentration. Concerning the mechanism of action, CPF-2 produced a rapid bactericidal effect by interrupting the bacterial membranes. Even more surprisingly, CPF-2 showed an excellent ability to prevent and eradicate biofilms caused by S. aureus and MRSA not only in vitro but also in vivo. Our results suggested that CPF-2 has potential as a lead compound to treat infections caused by S. aureus and MRSA, including the associated biofilms.

YC-1 potentiates the antitumor activity of gefitinib by inhibiting HIF-1α and promoting the endocytic trafficking and degradation of EGFR in gefitinib-resistant non-small-cell lung cancer cells.

The tyrosine kinase inhibitor (TKI) gefitinib exerts good therapeutic effect on NSCLC patients with sensitive EGFR-activating mutations. However, most patients ultimately relapse due to the development of drug resistance after 6-12 months of treatment. Here, we showed that a HIF-1α inhibitor, YC-1, potentiated the antitumor efficacy of gefitinib by promoting EGFR degradation in a panel of human NSCLC cells with wild-type or mutant EGFRs. YC-1 alone had little effect on NSCLC cell survival but significantly enhanced the antigrowth and proapoptotic effects of gefitinib. In insensitive NSCLC cell lines, gefitinib efficiently inhibited the phosphorylation of EGFR but not the downstream signaling of ERK, AKT and STAT3; however, when combined with YC-1 treatment, these signaling pathways were strongly impaired. Gefitinib treatment induced EGFR arrest in the early endosome, and YC-1 treatment promoted delayed EGFR transport into the late endosome as well as receptor degradation. Moreover, the YC-1-induced reduction of HIF-1α protein was associated with the enhancement of EGFR degradation. HIF-1α knockdown promoted EGFR degradation, showing synergistic antigrowth and proapoptotic effects similar to those of the gefitinib and YC-1 combination treatment in NSCLC cells. Our findings provide a novel combination treatment strategy with gefitinib and YC-1 to extend the usage of gefitinib and overcome gefitinib resistance in NSCLC patients.

Enhanced cell selectivity of hybrid peptides with potential antimicrobial activity and immunomodulatory effect.

BACKGROUND: Hybridization is a useful strategy to bond the advantages of different peptides into novel constructions. We designed a series of AMPs based on the structures of a synthetic AMP KFA3 and a naturally-occurred host defense peptide substance P (SP) to obtain peptides retaining the high antibacterial activity of KFA3 and the immunomodulatory activity and low cytotoxicity of SP. METHODS: Two repeats of KFA and different C terminal fragments of SP were hybridized, generating a series of novel AMPs (KFSP1-8). The antibacterial activities, host cell toxicity and immunomodulation were measured. The antibacterial mechanisms were investigated. RESULTS: Hybrid peptides KFSP1-4 exerted substantial antibacterial activities against Gram-negative bacteria of standard strains and clinical drug-resistant isolates including E.coli, A.baumannii and P.aeruginosa, while showing little toxicity towards host cells. Compared with KFA3, moderate reduction in α-helix content and the interruption in α-helix continuality were indicated in CD spectra analysis and secondary-structure simulation in these peptides. Membrane permeabilization combined with time-kill studies and FITC-labeled imaging, indicated a selective membrane interaction of KFSP1 with bacteria cell membranes. By specially activating NK1 receptor, the hybrid peptides kept the ability of SP to induce intracellular calcium release and ERK1/2 phosphorylation, but unable to stimulate NF-κB phosphorylation. KFSP1 facilitated the survival of mouse macrophage RAW264.7, directly interacting with LPS and inhibiting the LPS-induced NF-κB phosphorylation and TNF-α expression. CONCLUSION: Hybridization is a useful strategy to bond the advantages of different peptides. KFSP1 and its analogs are worth of advanced efforts to explore their potential applications as novel antimicrobial agents.

Efficient synthesis of cyclic amidine-based fluorophores via 6π-electrocyclic ring closure.

Novel 10π-electron cyclic amidines with excellent fluorescence properties were synthesized by a general and efficient 6π-electrocyclic ring closure of ketenimine and imine starting from N-sulfonyl triazoles and arylamines. The photophysical properties of cyclic amidine fluorophores have been studied in detail and have shown good properties of a large Stokes shift, pH insensitivity, low cytotoxicity and higher photostability, which have great potential for biological imaging. Furthermore, this novel fluorophore was successfully applied to the localization of the NK-1 receptor in living systems.

Potent effects of amino acid scanned antimicrobial peptide Feleucin-K3 analogs against both multidrug-resistant strains and biofilms of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is particularly difficult to treat because it possesses a variety of resistance mechanisms and because it often forms biofilms. Antimicrobial peptides represent promising candidates for future templates of antibiotic-resistant bacterial infections due to their unique mechanism of antimicrobial action. In this study, we first found that the antimicrobial peptide Feleucin-K3 has potent antimicrobial activity against not only the standard strain of P. aeruginosa but also against the multidrug-resistant strains isolated from clinics. Then, the structure-activity relationship of the peptide was investigated using alanine and D-amino acid scanning. Among the analogs synthesized, FK-1D showed much more potent antimicrobial activity, superior stability, and very low toxicity, and it was able to permeabilize bacterial membranes. Furthermore, it exhibited significant anti-biofilm activity. More importantly, FK-1D showed excellent antimicrobial activity in vivo, especially against clinical multidrug-resistant bacteria, in contrast to ceftazidime. Our results suggested that FK-1D could be subjected to fixed-point modification in the first and fourth sites to further optimize its medicinal properties and potential as a lead compound for the treatment of infections caused by multidrug-resistant P. aeruginosa and the associated biofilms.

Identification and preliminary characterization of Hc-clec-160, a novel C-type lectin domain-containing gene of the strongylid nematode Haemonchus contortus.

BACKGROUND: The strongylid parasite Haemonchus contortus causes severe anemia in domestic animals worldwide. Effective preventive and therapeutical agents are lacking, because of drug resistance and that little is known about the molecular mechanism of the interaction between H. contortus and host cells. METHODS: A new gene, Hc-clec-160, was discovered with RT-PCR. Transcriptional levels of Hc-clec-160 and Ce-clec-160 throughout different growth phases of corresponding nematodes were assayed by qPCR. Immunofluorescence staining of paraffin section were performed to determine the protein localization in adult worms of H. contortus. To monitor the promoter capacity of the 5'-flanking region of Ce-clec-160, micro-injection was used. Overexpression and RNAi constructs was carried out in the N2 strain of Caenorhabditis elegans to find out the gene function of Hc-clec-160. RESULTS: The full-length cDNA of 1224 bp of Hc-clec-160 was cloned by RT-PCR. The corresponding gene contained twelve exons. Its transcripts peaked in male adult worms. Hc-CLEC-160 was predicted to have a Willebrand factor type A (vWA) domain and a C-type lectin domain. The proteins were not detected by expression in C. elegans or paraffin section experiments in adult of H. contortus. Knockdown of Ce-clec-160 expression in C. elegans by RNAi resulted in shortened body length and decreased brood size. CONCLUSIONS: In this experiment, a new gene Hc-clec-160 was obtained in H. contortus and its function was addressed using a model organism: C. elegans. Our study showed that Hc-clec-160 possesses characteristics similar to those of Ce-clec-160 and plays an important role in the growth and reproduction of this parasitic nematode.

MEL-N16: A Series of Novel Endomorphin Analogs with Good Analgesic Activity and a Favorable Side Effect Profile.

Opioid peptides are neuromodulators that bind to opioid receptors and reduce pain sensitivity. Endomorphins are among the most active endogenous opioid peptides, and they have good affinity and selectivity toward the µ opioid receptor. However, their clinical usage is hindered by their inability to cross the blood-brain barrier and their poor in vivo activity after peripheral injection. In order to overcome these defects, we have designed and synthesized a series of novel endomorphin analogs with multiple site modifications. Radioligand binding, cAMP accumulation, and ß-arrestin-2 recruitment assays were employed to determine the activity of synthesized endomorphin analogs toward opioid receptors. The blood-brain barrier permeability and antinociceptive effect of these analogs were determined in several rodent models of acute and persistent pain. In addition, the side effects of the analogs were examined. The radioligand binding assay and functional activity examination indicated that the MEL-N16 series of compounds were more active agonists against µ opioid receptor than were the parent peptides. Notably, the analogs displayed biased downstream signaling toward G-protein pathways over ß-arrestin-2 recruitment. The analogs showed highly potent antinociceptive effects in the tested nociceptive models. In comparison with endomorphins, the synthesized analogs were better able to penetrate the blood-brain barrier and exerted their pain regulatory activity in the central nervous system after peripheral injection. These analogs also have lower tendency to cause side effects than morphine does at similar or equal antinociceptive doses. The MEL-N16 compounds have highly potent and efficacious analgesic effects in various pain models with a favorable side effect profile.

Endomorphin-1 analogs containing α-methyl-ß-amino acids exhibit potent analgesic activity after peripheral administration.

This study describes the design and synthesis of endomorphin-1 analogs containing C-terminal aromatic α-methyl-ß-amino acids and an N-terminal native tyrosine or 2,6-dimethyl-tyrosine. We show that, in comparison with the parent peptide, these analogs exhibit improved bioactivity and blood-brain barrier penetration after intravenous administration, and have a lower tendency to induce constipation and sedation than morphine.

Novel antimicrobial peptide CPF-C1 analogs with superior stabilities and activities against multidrug-resistant bacteria.

As numerous clinical isolates are resistant to most conventional antibiotics, infections caused by multidrug-resistant bacteria are associated with a higher death rate. Antimicrobial peptides show great potential as new antibiotics. However, a major obstacle to the development of these peptides as useful drugs is their low stability. To overcome the problem of the natural antimicrobial peptide CPF-C1, we designed and synthesized a series of analogs. Our results indicated that by introducing lysine, which could increase the number of positive charges, and by introducing tryptophan, which could increase the hydrophobicity, we could improve the antimicrobial activity of the peptides against multidrug-resistant strains. The introduction of d-amino acids significantly improved stability. Certain analogs demonstrated antibiofilm activities. In mechanistic studies, the analogs eradicated bacteria not just by interrupting the bacterial membranes, but also by linking to DNA, which was not impacted by known mechanisms of resistance. In a mouse model, certain analogs were able to significantly reduce the bacterial load. Among the analogs, CPF-9 was notable due to its greater antimicrobial potency in vitro and in vivo and its superior stability, lower hemolytic activity, and higher antibiofilm activity. This analog is a potential antibiotic candidate for treating infections induced by multidrug-resistant bacteria.

ß-Arrestin 1 has an essential role in neurokinin-1 receptor-mediated glioblastoma cell proliferation and G2/M phase transition.

Glioblastoma is the most common malignant brain tumor and has a poor prognosis. Tachykinin receptor neurokinin-1 (NK1R) is a promising target in glioblastoma therapy because of its overexpression in human glioblastoma. NK1R agonists promote glioblastoma cell growth, whereas NK1R antagonists efficiently inhibit cell growth both in vitro and in vivo However, the molecular mechanisms involved in these effects are incompletely understood. ß-Arrestins (ARRBs) serve as scaffold proteins and adapters to mediate intracellular signal transduction. Here we show that the ARRB1-mediated signaling pathway is essential for NK1-mediated glioblastoma cell proliferation. ARRB1 knockdown significantly inhibited NK1-mediated glioblastoma cell proliferation and induced G2/M phase cell cycle arrest. ARRB1 knockdown cells showed remarkable down-regulation of CDC25C/CDK1/cyclin B1 activity. We also demonstrated that ARRB1 mediated prolonged phosphorylation of ERK1/2 and Akt in glioblastoma cells induced by NK1R activation. ERK1/2 and Akt phosphorylation are involved in regulating CDC25C/CDK1/cyclin B1 activity. The lack of long-term ERK1/2 and Akt activation in ARRB1 knockdown cells was at least partly responsible for the delayed cell cycle progression and proliferation. Moreover, we found that ARRB1-mediated ERK1/2 and Akt phosphorylation regulated the transcriptional activity of both NF-κB and AP-1, which were involved in cyclin B1 expression. ARRB1 deficiency increased the sensitivity of glioblastoma cells to the treatment of NK1R antagonists. Taken together, our results suggest that ARRB1 plays an essential role in NK1R-mediated cell proliferation and G2/M transition in glioblastoma cells. Interference with ARRB1-mediated signaling via NK1R may have potential significance for therapeutic strategies targeting glioblastoma.

Neurokinin-1 receptor mediated breast cancer cell migration by increased expression of MMP-2 and MMP-14.

Breast cancer (BC) is a common reason of cancer-associated death in female. To develop novel strategy of therapeutics, it is crucial to comprehensively understand the receptor status of BC cells on the surface and inner, because chemical messengers can bind the receptors and promote tumorigenesis. Compared with normal and benign samples, BC cell lines and malignant biopsies showed higher expression of neurokinin-1 receptor (NK1). In current work, we examined the role and mechanism of NK1 receptor signaling in BC cell migration. Human hemokinin-1 (hHK-1) was the peripheral agonist of NK1 receptor. Our results showed that by activating NK1 receptor, hHK-1 promoted the migration of BC cells. Gelatin zymography and WB experiment showed that hHK-1 enhanced the levels of MMP-2 and MMP-14; inhibition of these two MMPs blocked hHK-1-induced cell migration. We further explored the underlying mechanism. hHK-1 incuced the phosphorylation of ERK1/2, JNK and Akt through PKC or PKA pathway. The phosphorylation of these kinases further regulated the activation of transcriptional factor AP-1 and NF-κB. Inhibition of AP-1 and NF-κB reduced the up-regulation of MMP-2 and MMP-14 by hHK-1. Taken together, we showed NK1 receptor was an important regulator of human BC cell migration and a potential target for BC treatment.