CEMIP-mediated hyaluronan metabolism facilitates SCLC metastasis by activating TLR2/c-Src/ERK1/2 axis.

Small-cell lung cancer (SCLC) is a highly metastatic and recalcitrant malignancy. Metastasis is the major cause of death in patients with SCLC but its mechanism remains poorly understood. An imbalance of hyaluronan catabolism in the extracellular matrix accelerates malignant progression in solid cancers due to the accumulation of low-molecular-weight HA. We previously found that CEMIP, a novel hyaluronidase, may act as a metastatic trigger in SCLC. In the present study, we found that both CEMIP and HA levels were higher in SCLC tissues than in paracancerous tissues from patient specimens and in vivo orthotopic models. Additionally, high expression of CEMIP was associated with lymphatic metastasis in patients with SCLC, and in vitro results showed that CEMIP expression was elevated in SCLC cells relative to human bronchial epithelial cells. Mechanistically, CEMIP facilitates the breakdown of HA and accumulation of LMW-HA. LMW-HA activates its receptor TLR2, and subsequently recruits c-Src to activate ERK1/2 signalling, thereby promoting F-actin rearrangement as well as migration and invasion of SCLC cells. In addition, the in vivo results verified that depletion of CEMIP attenuated HA levels and the expressions of TLR2, c-Src, and phosphorylation of ERK1/2, as well as liver and brain metastasis in SCLC xenografts. Furthermore, the application of the actin filament inhibitor latrunculin A significantly inhibited the liver and brain metastasis of SCLC in vivo. Collectively, our findings reveal the critical role of CEMIP-mediated HA degradation in SCLC metastasis and suggest its translational potential as an attractive target and a novel strategy for SCLC therapy.

Expression and Predictive Significance of FHL1 and SLIT3 in Surgically Resected Lung Adenocarcinoma.

OBJECTIVE: Lung adenocarcinoma (LUAD) is the most common type of lung cancer. However, predictive biomarkers for early efficacy and prognosis evaluation in patients with surgically resected LUAD are not completely explained. METHODS: Differentially expressed genes (DEGs), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were identified by RNA sequencing (RNA-Seq) between thirteen LUAD tissues and five normal lung tissues. The expression of DEGs was confirmed by qRT-PCR and a validated cohort from GEPIA. Protein-protein interaction (PPI) network of the top 5% DEGs was constructed by STRING and visualized in Cytoscape. Immunofluorescence results were acquired from clinical specimens from LUAD patients. The expression of FHL1 was analyzed by ImageJ. Survival analysis was performed using the GEPIA dataset. RESULTS: Consistent with the RNA-Seq data, validation of DEGs expression by qRT-PCR and GEPIA cohort showed that FHL1 and SLIT3 were down-regulated in LUAD patient tissues compared with non-tumor tissues. Moreover, FHL1 was significantly reduced in LUAD cell lines compared to the bronchial epithelium cell line (P < 0.01). However, SLIT3 was elevated in A549 and H1299 cells (wide type EGFR) (P < 0.05) while decreased in HCC827 and PC9 cells (mutant EGFR) compared to BESA-2B cells (P < 0.01). PPI network revealed the most significant cluster with 10 nodes and 43 edges. Immunofluorescent staining also showed that the expression of FHL1 was lower in LUAD tissues compared with that in normal lung tissues (P < 0.01). The expressions of SLIT3 and FHL1 were positively correlated. Specifically, the higher expression level of SLIT3 and FHL1 independently predicted a better prognosis (P < 0.01 or P < 0.05). CONCLUSION: Our findings provide two novel candidates, FHL1 and SLIT3, for prognostic evaluation and treatments after surgery.

'Two-faces' of hyaluronan, a dynamic barometer of disease progression in tumor microenvironment.

Hyaluronan (HA) is a linear polysaccharide consisting of disaccharide units which are the D-glucuronic acid and N-acetyl-D-glucosamine. As the largest component of the extracellular matrix in microenvironment, HA polymers with different molecular weights vary in properties to molecular biology function. High molecular weight HA (HMW-HA) is mainly found in normal tissue or physiological condition, and exhibits lubrication and protection properties due to its good water retention and viscoelasticity. On the other hand, an increase in HA catabolism leads to the accumulation of low molecular weight HA (LMW-HA) under pathological circumstances such as inflammation, pre-cancerous and tumor microenvironment. LMW-HA acts as extracellular signals to enhance tumorigenic and metastatic phenotype, such as energy reprogramming, angiogenesis and extracellular matrix (ECM) remodeling. This review discusses the basic properties of this simplest carbohydrate molecule in ECM with enormous potential, and its regulatory role between tumorigenesis and microenvironmental homeostasis. The extensive discoveries of the mechanisms underlying the roles of HA in various physiological and pathological processes would provide more information for future research in the fields of biomimetic materials, pharmaceutical and clinical applications.

Upregulated UCA1 contributes to oxaliplatin resistance of hepatocellular carcinoma through inhibition of miR-138-5p and activation of AKT/mTOR signaling pathway.

Hepatocellular carcinoma (HCC) inevitably developed oxaliplatin (OXA) resistance after long-term treatment, but the mechanism remains unclear. Here, we found that LncRNA UCA1 was upregulated in most of OXA-resistant HCC tissues and cells (HepG2/OXA and SMMC-7721/OXA). Follow-up analysis and online Kaplan-Meier Plotter revealed that HCC patients with high UCA1 level had a shorter survival compared with those with low expression. Overexpression of UCA1 increased OXA IC50 in HepG2 and SMMC-7721 cells, whereas knockdown of UCA1 decreased OXA IC50 in resistant counterparts. Moreover, dual luciferase reporter assay showed that co-transfection of UCA1-WT plasmid with miR-138-5p mimics enhanced fluorescence signals, whereas co-transfection of UCA1-Mut plasmid and miR-138-5p mimics did not induce any changes. Consistently, UCA1 levels in HepG2/OXA and SMMC-7721/OXA cells were downregulated after transfected with miR-138-5p mimics. UCA1 silencing or transfection of miR-138-5p mmics inhibited the activation of AKT and mTOR in HepG2/OXA and SMMC-7721/OXA cells, whereas UCA1 overexpression increased the phosphorylated AKT and mTOR levels in parental counterparts. Rapamycin or miR-138-5p mimics similarly suppressed the activation of AKT and mTOR, whereas UCA1 overexpression exert opposite roles. Interestingly, administration of rapamycin or miR-138-5p mimics apparently antagonized the effects of UCA1 on AKT and mTOR activation. Besides, depletion of UCA1 triggered more dramatic regression of HepG2 xenografts than that of HepG2/OXA xenografts with OXA treatment and impaired the p-AKT and p-mTOR levels in vivo. In conclusion, our findings provide the evidence that UCA1 may contribute to OXA resistance via miR-138-5p-mediated AK /mTOR activation, suggesting that UCA1 is a potential therapeutic target for HCC.

Identification of a novel therapeutic candidate, NRK, in primary cancer-associated fibroblasts of lung adenocarcinoma microenvironment.

PURPOSE: Lung adenocarcinoma (LUAD) accounts for approximately half of patients in lung cancer. Cancer-associated fibroblasts (CAFs) are the major component in the tumor microenvironment (TME). Targeting CAFs is a promising therapeutic strategy for cancer treatment. However, therapeutic targets of CAFs in LUAD remains largely unclear. METHODS: Seven CAFs and nine normal fibroblasts (NFs) were isolated from tumor and paratumor tissues of LUAD patients undergoing surgery, respectively. RNA-seq and bioinformatics analysis were performed to identify the differentially expressed genes (DEGs) and their functions in CAFs compared with NFs. DEGs of ten overlaying were obtained from RNA-seq, our previously reported lncRNA microarray and public datasets (E-MTAB-6149, E-MTAB-6653) and validated by RT-qPCR. Nik-related kinase (NRK) was further validated by RT-qPCR, immunofluorescence (IF), Western Blot (WB) in vitro, and in Cancer Cell Line Encyclopedia (CCLE) database. Survival analysis was performed on Kaplan-Meier plotter. RESULTS: A total of 1799 DEGs were identified, including 650 upregulated DEGs and 1149 downregulated DEGs. The upregulated and downregulated DEGs were mostly enriched in extracellular matrix (ECM) functions and in glycolysis/gluconeogenesis pathways. Interestingly, NRK was the most significantly upregulated overlaying DEGs which was rarely associated with CAFs before. NRK was predominantly expressed in CAFs, but weakly expressed in NFs, normal lung bronchial epithelial cell line BEAS-2B, LUAD cell lines A549 and H1299, as well as in the majority of 191 lung cancer cell lines including LUAD. Moreover, elevated NRK predicted poor survival in LUAD patients. CONCLUSION: Here, we first report that NRK is significantly elevated in LUAD-associated CAFs and may function as a promising therapeutic target for cancer combination treatment. Besides, modulation of ECM and glycolysis/gluconeogenesis pathways may be an efficient approach to alter CAFs functionality in LUAD.

Nicotinamide, a vitamin B3 ameliorates depressive behaviors independent of SIRT1 activity in mice.

Sirtuin 1 (SIRT1), is a nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylase and a candidate gene for depression. Nicotinamide (NAM), a form of vitamin B3, is reported as a potential inhibitor of SIRT1. Our previous study found that the 24-h-restraint stress could induce long-term depressive-like phenotypes in mice. These mice displayed increased SIRT1 activity. Here, we studied whether NAM was capable of attenuating depressive behaviors through inhibiting SIRT1 activity. Surprisingly, the application of NAM significantly reversed the depressive behaviors but increased SIRT1 activity further. In contrast, the level of adenosine triphosphate (ATP) was reduced in the restraint model for depression, and recovered by the administration of NAM. Furthermore, the Sirt1flox/flox; Nestin-Cre mice exhibited antidepressant behaviors and increased ATP levels. These data suggest that ATP plays an important role in depression pathogenesis, and NAM could be a potential treatment method for depression by regulating ATP independent of SIRT1 activity.

A novel metastatic promoter CEMIP and its downstream molecular targets and signaling pathway of cellular migration and invasion in SCLC cells based on proteome analysis.

PURPOSE: Metastasis is an unavoidable event happened among almost all small cell lung cancer (SCLC) patients. However, the molecular driven factors have not been elucidated. Recently, a novel hydrolase called cell migration inducing hyaluronidase (CEMIP) triggered both migration and invasion in many tumors but not SCLC. Therefore, in this study, we verified that CEMIP promoted migration and invasion in SCLC and applied proteomics analysis to screen out potential target profiles and the signaling pathway related to CEMIP regulation. METHOD: Immunofluorescence was conducted to exam the expression of CEMIP on SCLC and paired adjacent normal tissues among enrollment. RT-qPCR and Western blot (WB) assays were conducted to valuate cellular protein and mRNA expression of CEMIP and EMT markers. Lentivirus-CEMIP-shRNAs and CEMIP plasmid were used for expression manipulating. Changes of cellular migration and invasion were tested through transwell assays. Tandem Mass Tag (TMT) peptide labeling coupled with LC-MS/MS was used for quantifying proteins affected by reducing expression of CEMIP on H446 cells. RESULTS: The expression of CEMIP showed 1.64 ± 0.16-fold higher in SCLC tissues than their normal counterpart. Decreasing the expression of CEMIP on SCLC cells H446 regressed both cellular migration and invasion ability, whereas the promoting cellular migration and invasion was investigated through over-expressing CEMIP on H1688. Proteomic and bioinformatics analysis revealed that total 215 differentially expressed proteins (DEPs) that either their increasing or decreasing relative expression met threshold of 1.2-fold changes with p value ≤ 0.05. The dramatic up-regulated DEPs included an unidentified peptide sequence (encoded by cDNA FLJ52096) SPICE1 and CRYAB, while the expression of S100A6 was largely down-regulated. DEPs mainly enriched on caveolae of cellular component, calcium ion binding of biological process and epithelial cell migration of molecular function. KEGG enrichment indicated that DEPs mainly exerted their function on TGF-ß, GABAergic synapse and MAPK signaling pathway. CONCLUSION: It is the first report illustrating that CEMIP might be one of the metastatic triggers in SCLC. And also, it provided possible molecular mechanism cue and potential downstream target on CEMIP-induced cellular migration and invasion on SCLC.

Abnormal circadian oscillation of hippocampal MAPK activity and power spectrums in NF1 mutant mice.

Studies have implied that the circadian oscillation of mitogen-activated protein kinase (MAPK) signal pathways is crucial for hippocampus-dependent memory. NF1 mouse models (Nf1 heterozygous null mutants; Nf1 +/-) displayed enhanced MAPK activity in the hippocampus and resulted in memory deficits. We assumed a link between MAPK pathways and hippocampal rhythmic oscillations, which have never been explored in Nf1 +/- mice. We demonstrated that the level of extracellular signal-regulated kinases 1 and 2 (ERK1/2) phosphorylation in Nf1 +/- mice were significantly higher at nighttime than at daytime. Moreover, the in vivo recording revealed that for the Nf1 +/- group, the power spectral density of theta rhythm significantly decreased and the firing rates of pyramidal neurons increased. Our results indicated that the hippocampal MAPK oscillation and theta rhythmic oscillations in Nf1 +/- mice were disturbed and hinted about a possible mechanism for the brain dysfunction in Nf1 +/- mice.

CD20 Antibody-Conjugated Immunoliposomes for Targeted Chemotherapy of Melanoma Cancer Initiating Cells.

Cancer initiating cells (CIC) are tumorigenic cancer cells that have properties similar to normal stem cells. CD20 is a phenotype of melanoma CIC that is responsible for melanoma drug resistance. Vincristine (VCR) is commonly used in melanoma therapy; however, it has been found ineffective against CIC. To target CD20+ melanoma CIC, we prepared VCR-containing immunoliposomes that were conjugated to CD20 antibodies (VCR-Lip-CD20). The drug release profile and the antibody-mediated targeting of the immunoliposomes were optimized to target CD20+ melanoma CIC. The immunoliposomes had desirable particle size (163 nm), drug encapsulation efficiency (91.8%), and drug release profile. We demonstrated that these immunoliposomes could successfully target more than 55% of CD20+ Chinese Hamster Ovary cells (CHO-CD20) even when the CHO-CD20 cells accounted for only 0.1% of a mixed population of CHO-CD20 and CHO cells. After treating WM266-4 melanoma mammospheres for 96 h, the ICo values of the drug delivered in VCR-Lip-CD20, VCR-Lip (VCR liposomes), and VCR were found to be 53.42, 98.99, and 99.09 µg/mL, respectively, suggesting that VCR-Lip-CD20 was 1.85 times more effective than VCR-Lip and VCR. VCR-Lip-CD20 could almost completely remove the tumorigenic ability of WM266-4 mammospheres in vivo, and showed the best therapeutic effect in WM266-4 melanoma xenograft mice. Significantly, VCR-Lip-CD20 could selectively kill CD20+ melanoma CIC in populations of WM266-4 cells both in vitro and in vivo. We demonstrated that VCR-Lip-CD20 has the potential to efficiently target and kill CD20+ melanoma CIC.

Polymer-lipid hybrid nanoparticles conjugated with anti-EGF receptor antibody for targeted drug delivery to hepatocellular carcinoma.

AIMS: The aim of this study was to obtain adriamycin-loaded polymer-lipid hybrid nanoparticles conjugated with anti-EGF receptor antibody (PLNP-Mal-EGFR) for hepatocellular carcinoma (HCC) chemotherapy. MATERIALS & METHODS: The nanoparticles were characterized by dynamic light scattering and fluorescence spectroscopy. The in vitro and in vivo distribution and anti-tumor activity of the nanoparticles were evaluated. RESULTS & CONCLUSION: PLNP-Mal-EGFR showed significantly enhanced cellular cytotoxicity against HCC cells overexpressing EGFR compared with nontargeted nanoparticles (polymer-lipid hybrid nanoparticles [containing DSPE-PEG-Mal] and polymer-lipid hybrid nanoparticles [containing DSPE-mPEG] combined with anti-EGFR Fab´). PLNP-Mal-EGFR and nontargeted nanoparticles could significantly reduce the proportion of side-population cells in HCC cells. The in vivo accumulation of PLNP-Mal-EGFR was obviously higher than that of nontargeted nanoparticles in SMMC-7721 HCC cells overexpressing EGFR. Notably, PLNP-Mal-EGFR showed significantly enhanced anti-tumor activity against HCC in vivo compared with nontargeted nanoparticles and free adriamycin. Therefore, PLNP-Mal-EGFR may serve as an effective therapeutic approach for HCC chemotherapy.

Bispecific antibody to ErbB2 overcomes trastuzumab resistance through comprehensive blockade of ErbB2 heterodimerization.

The anti-ErbB2 antibody trastuzumab has shown significant clinical benefits in metastatic breast cancer. However, resistance to trastuzumab is common. Heterodimerization between ErbB2 and other ErbBs may redundantly trigger cell proliferation signals and confer trastuzumab resistance. Here, we developed a bispecific anti-ErbB2 antibody using trastuzumab and pertuzumab, another ErbB2-specific humanized antibody that binds to a distinct epitope from trastuzumab. This bispecific antibody, denoted as TPL, retained the full binding activities of both parental antibodies and exhibited pharmacokinetic properties similar to those of a conventional immunoglobulin G molecule. Unexpectedly, TPL showed superior ErbB2 heterodimerization-blocking activity over the combination of both parental monoclonal antibodies, possibly through steric hindrance and/or inducing ErbB2 conformational change. Further data indicated that TPL potently abrogated ErbB2 signaling in trastuzumab-resistant breast cancer cell lines. In addition, we showed that TPL was far more effective than trastuzumab plus pertuzumab in inhibiting the growth of trastuzumab-resistant breast cancer cell lines, both in vitro and in vivo. Importantly, TPL treatment eradicated established trastuzumab-resistant tumors in tumor-bearing nude mice. Our results suggest that trastuzumab-resistant breast tumors remain dependent on ErbB2 signaling and that comprehensive blockade of ErbB2 heterodimerization may be an effective therapeutic avenue. The unique potential of TPL to overcome trastuzumab resistance warrants its consideration as a promising treatment in the clinic.

Inhibition of hepatocellular carcinoma growth using immunoliposomes for co-delivery of adriamycin and ribonucleotide reductase M2 siRNA.

The chemotherapy combined with gene therapy has received great attention. We developed targeted LPD (liposome-polycation-DNA complex) conjugated with anti-EGFR (epidermal growth factor receptor) Fab' co-delivering adriamycin (ADR) and ribonucleotide reductase M2 (RRM2) siRNA (ADR-RRM2-TLPD), to achieve combined therapeutic effects in human hepatocellular carcinoma (HCC) overexpressing EGFR. The antitumor activity and mechanisms of ADR-RRM2-TLPD were investigated. The results showed that RRM2 expression was higher in HCC than in non-HCC tissue, and RRM2 siRNA inhibited HCC cell proliferation, suggesting that RRM2 is a candidate target for HCC therapy. ADR-RRM2-TLPD delivered ADR and RRM2 siRNA to EGFR overexpressing HCC cells specifically and efficiently both in vitro and in vivo, resulting in enhanced therapeutic effects (cytotoxicity, apoptosis and senescence-inducing activity) compared with single-drug loaded or non-targeted controls, including ADR-NC-TLPD (targeted LPD co-delivering ADR and negative control siRNA), RRM2-TLPD (targeted LPD delivering RRM2 siRNA) and ADR-RRM2-NTLPD (non-targeted LPD co-delivering ADR and RRM2 siRNA). Mechanism studies showed that p21 is involved in the combined therapeutic effect of ADR-RRM2-TLPD. The average weight of the orthotopic HCC in mice treated with ADR-RRM2-TLPD was significantly lighter than that of mice treated with other controls. Thus, ADR-RRM2-TLPD represents a potential strategy for combined therapy of HCC overexpressing EGFR.

Effective suppression of breast tumor growth by an anti-EGFR/ErbB2 bispecific antibody.

Despite the effectiveness of the anti-ErbB2 humanized antibody trastuzumab, less than 35% of patients with ErbB2-overexpressing breast cancer respond to the treatment. Here we engineered an anti-EGFR/ErbB2 bispecific antibody (TC-BsAb) using trastuzumab and cetuximab, an anti-EGFR chimeric antibody. TC-BsAb treatment led to internalization of both EGFR and ErbB2, whereas trastuzumab and cetuximab, either alone or in combination, failed to induce ErbB2 internalization. Both in vitro and in vivo experiments indicated that TC-BsAb was significantly more potent in inhibiting the growth of breast cancer cell lines than trastuzumab, cetuximab, and trastuzumab plus cetuximab, suggesting its potential use for treating breast cancer.

EGFR-specific PEGylated immunoliposomes for active siRNA delivery in hepatocellular carcinoma.

The development of immunoliposomes for systemic siRNA (small interfering RNA) delivery is highly desired. We reported previously the development of targeted LPD (liposome-polycation-DNA complex) conjugated with anti-EGFR (epidermal growth factor receptor) Fab' (TLPD-FCC) for siRNA delivery, which showed superior gene silencing activity in EGFR-overexpressing breast cancers. However, TLPD-FCC did not achieve satisfactory gene silencing activity in EGFR-overexpressing hepatocellular carcinoma (HCC). In this study, some modifications including increased antibody conjugation efficiency and reduced PEGylation degree were made to TLPD-FCC to increase gene silencing activity in HCC. The resultant optimized liposomes denoted as TLPD-FP75 efficiently bound and delivered to EGFR-overexpressing HCC, resulting in enhanced gene silencing activity compared to untargeted LPD (NTLPD-FP75). Tissue distribution in vivo revealed that the accumulation of TLPD-FP75 was higher than NTLPD-FP75 in orthotopic HCC model of mice. The promoted uptake of TLPD-FP75 in HCC cells was confirmed by confocal microscopy. To investigate the in vivo gene silencing activity, we administered TLPD-FP75 by intravenous injections into mice bearing orthotopic HCC. The results showed TLPD-FP75 potently suppressed luciferase expression, while little silencing was observed in NTLPD-FP75. TLPD-FP75 was demonstrated to possess potent gene silencing activity in HCC and will potentially increase the feasibility of HCC gene therapy.