FAP Serves as a Prognostic Biomarker in Head and Neck Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) poses significant challenges with poor survival rates and limited therapeutic strategies. Our study, using The Cancer Genome Atlas (TCGA) data, assesses cancer-associated fibroblast (CAF) gene signatures' clinical relevance. In our analysis across TCGA tumor types, differential gene expression analysis revealed that fibroblast activation protein (FAP) is upregulated in tumor tissues and associated with poorer survival rates in HNSCC. Furthermore, mechanistic studies employing gene-silencing techniques substantiated that FAP knockout led to a significant decrease in cellular proliferation, invasion, and migration in HNSCC cell lines. Through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses, we established that high FAP expression correlates with vital biological processes such as extracellular matrix organization, angiogenesis, and cellular motility. Importantly, FAP was found to regulate these processes by promoting the expression of key proteins involved in epithelial-mesenchymal transition-related pathways. Additionally, our analysis revealed a significant correlation between FAP expression and the expression profiles of immune checkpoint molecules, underscoring its potential role in immune modulation. Collectively, our findings illuminate FAP's pivotal role in HNSCC pathogenesis and its potential as a prognostic biomarker and therapeutic target. This research lays the groundwork for understanding the multifaceted roles and regulatory mechanisms of CAFs in HNSCC, thereby offering valuable perspectives for the development of targeted therapeutic strategies aimed at improving patient outcomes.

Antitumor efficacy and potential mechanism of FAP-targeted radioligand therapy combined with immune checkpoint blockade.

Radiotherapy combined with immune checkpoint blockade holds great promise for synergistic antitumor efficacy. Targeted radionuclide therapy delivers radiation directly to tumor sites. LNC1004 is a fibroblast activation protein (FAP)-targeting radiopharmaceutical, conjugated with the albumin binder Evans Blue, which has demonstrated enhanced tumor uptake and retention in previous preclinical and clinical studies. Herein, we demonstrate that 68Ga/177Lu-labeled LNC1004 exhibits increased uptake and prolonged retention in MC38/NIH3T3-FAP and CT26/NIH3T3-FAP tumor xenografts. Radionuclide therapy with 177Lu-LNC1004 induced a transient upregulation of PD-L1 expression in tumor cells. The combination of 177Lu-LNC1004 and anti-PD-L1 immunotherapy led to complete eradication of all tumors in MC38/NIH3T3-FAP tumor-bearing mice, with mice showing 100% tumor rejection upon rechallenge. Immunohistochemistry, single-cell RNA sequencing (scRNA-seq), and TCR sequencing revealed that combination therapy reprogrammed the tumor microenvironment in mice to foster antitumor immunity by suppressing malignant progression and increasing cell-to-cell communication, CD8+ T-cell activation and expansion, M1 macrophage counts, antitumor activity of neutrophils, and T-cell receptor diversity. A preliminary clinical study demonstrated that 177Lu-LNC1004 was well-tolerated and effective in patients with refractory cancers. Further, scRNA-seq of peripheral blood mononuclear cells underscored the importance of addressing immune evasion through immune checkpoint blockade treatment. This was emphasized by the observed increase in antigen processing and presentation juxtaposed with T cell inactivation. In conclusion, our data supported the efficacy of immunotherapy combined with 177Lu-LNC1004 for cancer patients with FAP-positive tumors.

Cancer-associated fibroblasts expressing fibroblast activation protein and podoplanin in non-small cell lung cancer predict poor clinical outcome.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are a dominant cell type in the stroma of non-small cell lung cancer (NSCLC). Fibroblast heterogeneity reflects subpopulations of CAFs, which can influence prognosis and treatment efficacy. We describe the subtypes of CAFs in NSCLC. METHODS: Primary human NSCLC resections were assessed by flow cytometry and multiplex immunofluorescence for markers of fibroblast activation which allowed identification of CAF subsets. Survival data were analysed for our NSCLC cohort consisting of 163 patients to understand prognostic significance of CAF subsets. RESULTS: We identified five CAF populations, termed CAF S1-S5. CAF-S5 represents a previously undescribed population, and express FAP and PDPN but lack the myofibroblast marker αSMA, whereas CAF-S1 populations express all three. CAF-S5 are spatially further from tumour regions then CAF-S1 and scRNA data demonstrate an inflammatory phenotype. The presence of CAF-S1 or CAF-S5 is correlated to worse survival outcome in NSCLC, despite curative resection, highlighting the prognostic importance of CAF subtypes in NSCLC. TCGA data suggest the predominance of CAF-S5 has a poor prognosis across several cancer types. CONCLUSION: This study describes the fibroblast heterogeneity in NSCLC and the prognostic importance of the novel CAF-S5 subset where its presence correlates to worse survival outcome.

Probiotic Potential and Safety Assessment of Lactiplantibacillus plantarum cqf-43 and Whole-Genome Sequence Analysis.

This study reports the whole-genome sequence of Lactiplantibacillus plantarum cqf-43 isolated from healthy sow feces. Based on genomic analysis, we performed a comprehensive safety assessment of strain cqf-43, using both in vitro and in vivo experiments, and explored its probiotic potential. The total genome length measures 3,169,201 bp, boasting a GC content of 44.59%. Through phylogenetic analyses, leveraging both 16S rRNA gene and whole-genome sequences, we confidently categorize strain cqf-43 as a member of Lactiplantibacillus. Genome annotation using Prokka unveiled a total of 3141 genes, encompassing 2990 protein-coding sequences, 71 tRNAs, 16 rRNAs, and 1 tmRNA. Functional annotations derived from COG and KEGG databases highlighted a significant abundance of genes related to metabolism, with a notable emphasis on carbohydrate utilization. The genome also revealed the presence of prophage regions and CRISPR-Cas regions while lacking virulence and toxin genes. Screening for antibiotic resistance genes via the CARD database yielded no detectable transferable resistance genes, effectively eliminating the potential for harmful gene transfer. It is worth highlighting that the virulence factors identified via the VFDB database primarily contribute to bolstering pathogen resilience in hostile environments. This characteristic is particularly advantageous for probiotics. Furthermore, the genome is devoid of menacing genes such as hemolysin, gelatinase, and biogenic amine-producing genes. Our investigation also unveiled the presence of three unannotated secondary metabolite biosynthetic gene clusters, as detected by the online tool antiSMASH, suggesting a great deal of unknown potential for this strain. Rigorous in vitro experiments confirmed tolerance of strain cqf-43 in the intestinal environment, its antimicrobial efficacy, sensitivity to antibiotics, absence of hemolysis and gelatinase activity, and its inability to produce biogenic amines. In addition, a 28-day oral toxicity test showed that the strain cqf-43 did not pose a health hazard in mice, further establishing it as a safe strain.

A Theranostic Approach for CAR-T Cell Therapy.

Fibroblast activation protein (FAP) is frequently expressed in the tumor stroma, whereas expression by normal organs is highly restricted. Despite these promising features, FAP-targeted therapies have shown limited success so far. FAP imaging offers new opportunities to select patients for FAP-targeted therapies and monitor tumor response. See related article by Lee et al., p. 5330.

Legionella bononiensis sp. nov., isolated from a hotel water distribution system in northern Italy.

Legionella-like isolates, strains 27fs60, 30fs61 and 30cs62T, were isolated from a hotel water distribution system in the Emilia-Romagna region, Italy. Isolates were Gram- and Ziehl Neelsen-stain-negative, rod-shaped, with transitory flagella presence and able to grow at 32-37 °C (with an optimum at 32 °C) on buffered charcoal-yeast extract agar with l-cysteine, glycine-vancomycin-polymyxin B-cycloheximide agar and Wadowsky-Yee medium agar. The strains showed positive reactions for oxidase, hippurate and gelatinase and a weakly positive reaction for catalase. Based on the EUCAST cut-off, strain 30cs62T was resistant to ciprofloxacin (5 mg l-1). The mip and rpoB gene sequences of the three strains showed close matches to those of Legionella quateirensis ATCC 49507T with similarity values of 98.2 and 94.5 %, respectively. Whole genome sequencing of the three strains was performed, resulting in G+C contents of 39.0, 39.1 and 39.0 mol%, respectively. The identity percentage measured by average nucleotide identity between the three strains and their respective closest strains were: 91.32 % L. quateirensis NCTC 12376T, 91.45 % L. quateirensis ATCC 49507T and 91.45 % L. quateirensis ATCC 49507T, respectively. The digital DNA-DNA hybridization analysis demonstrated how the isolates were separated from the most related phylogenetic Legionella species (L. quateirensis ATCC 49507T, ≤40.10 % DNA-DNA relatedness). The concatenated phylogenetic tree based on 16S rRNA, mip, rpoB and rnpB genes, shows a close relationship with L. quateirensis ATCC 49507T. The results obtained confirm the status of an independent species. The name proposed for this species is Legionella bononiensis sp. nov. with 30cs62T (=ATCC TSD-262T=DSM 112526T) as the type strain.

Relationship between MMP-9 Gene Polymorphism and Intracranial Aneurysm.

Matrix metalloproteinase-9 (MMP-9) is a gelatinase, which is a member of the MMPs family. We know that MMP-9 is not only an important gelatinase to regulate the extracellular matrix balance, but also one of the most closely related proteases to the pathogenesis of intracranial aneurysm. The purpose of this study is to investigate the relationship between MMP-9 gene polymorphism and intracranial aneurysm. In this paper, 98 patients who were admitted to a hospital from 2018 to 2019 were selected as the experimental group and the control group according to the relevant standards of intracranial aneurysms. The MMP-9 positive and MMP-9 absorbance values between the two groups were compared, so as to determine the concentration of MMP-9 between the two groups. In addition, the gene distribution and gene frequency analysis of the C-1562T promoter region of MMP-9 were carried out. The results showed that in the control group, the gene distribution frequency of CC type was 67% that of CT type was 31% that of TT type was 2%, that of the experimental group was 52%, and that of CT type was 44%. The results showed that there was a correlation between MMP-9 gene polymorphism and intracranial aneurysm.

The Phosphatase Bph and Peptidyl-Prolyl Isomerase PrsA Are Required for Gelatinase Expression and Activity in Enterococcus faecalis.

Enterococcus faecalis is a common commensal bacterium in the gastrointestinal tract as well as a frequent nosocomial pathogen. The secreted metalloprotease gelatinase (GelE) is an important E. faecalis virulence factor that contributes to numerous cellular activities, such as autolysis, biofilm formation, and biofilm-associated antibiotic resistance. Expression of gelE has been extensively studied and is regulated by the Fsr quorum sensing system. Here, we identify two additional factors regulating gelatinase expression and activity in E. faecalis OG1RF. The Bph phosphatase is required for expression of gelE in an Fsr-dependent manner. Additionally, the membrane-anchored protein foldase PrsA is required for GelE activity, but not fsr or gelE gene expression. Disrupting prsA also leads to increased antibiotic sensitivity in biofilms independent of the loss of GelE activity. Together, our results expand the model for gelatinase production in E. faecalis, which has important implications for fundamental studies of GelE function in Enterococcus and also E. faecalis pathogenesis. IMPORTANCE In Enterococcus faecalis, gelatinase (GelE) is a virulence factor that is also important for biofilm formation and interactions with other microbes as well as the host immune system. The long-standing model for GelE production is that the Fsr quorum sensing system positively regulates expression of gelE. Here, we update that model by identifying two additional factors that contribute to gelatinase production. The biofilm-associated Bph phosphatase regulates the expression of gelE through Fsr, and the peptidyl-prolyl isomerase PrsA is required for production of active GelE through an Fsr-independent mechanism. This provides important insight into how regulatory networks outside of the fsr locus coordinate expression of gelatinase.

Fsr quorum sensing system modulates the temporal development of Enterococcus faecalis biofilm matrix.

Quorum sensing (QS) is a cell-to-cell communication process that regulates major pathogenic attributes in bacteria including biofilm formation, secretion of virulence factors, and antimicrobial resistance. The two-component Fsr-QS system of the nosocomial pathogen Enterococcus faecalis controls the production of extracellular gelatinase that contributes to biofilm development by enhancing the release of nucleic acids into the biofilm matrix. However, the contribution of this system to the deposition of other biofilm matrix components such as polysaccharides and proteins remains unknown. Using wild type and mutant strains, we discovered that biofilm formation was attenuated by inactivation of the Fsr system or its downstream gelatinase production. Inactivation of the Fsr system caused a modest, yet significant reduction in biofilm metabolic activity without affecting cell counts. Inactivation of the QS-signal sensor FsrC and response regulator FsrA resulted in decreased extracellular polysaccharides and proteins in biofilms in a temporal manner. Irrespective of biofilm age, eDNA levels were reduced in the gelatinase mutant strain. Our results collectively suggest that the Fsr system contributes to the temporal deposition of polysaccharides and proteins into the extracellular polymeric matrix (EPS) of E. faecalis biofilm, without affecting bacterial viability. This understanding of the role of the Fsr-QS system in biofilm development may reveal a novel target to develop effective antibiofilm agents to tackle E. faecalis-mediated infections such as in dental root canals, heart valves, and surgical sites.

Possibility for Transcriptional Targeting of Cancer-Associated Fibroblasts-Limitations and Opportunities.

Cancer-associated fibroblasts (CAF) are attractive therapeutic targets in the tumor microenvironment. The possibility of using CAFs as a source of therapeutic molecules is a challenging approach in gene therapy. This requires transcriptional targeting of transgene expression by cis-regulatory elements (CRE). Little is known about which CREs can provide selective transgene expression in CAFs. We hypothesized that the promoters of FAP, CXCL12, IGFBP2, CTGF, JAG1, SNAI1, and SPARC genes, the expression of whose is increased in CAFs, could be used for transcriptional targeting. Analysis of the transcription of the corresponding genes revealed that unique transcription in model CAFs was characteristic for the CXCL12 and FAP genes. However, none of the promoters in luciferase reporter constructs show selective activity in these fibroblasts. The CTGF, IGFBP2, JAG1, and SPARC promoters can provide higher transgene expression in fibroblasts than in cancer cells, but the nonspecific viral promoters CMV, SV40, and the recently studied universal PCNA promoter have the same features. The patterns of changes in activity of various promoters relative to each other observed for human cell lines were similar to the patterns of activity for the same promoters both in vivo and in vitro in mouse models. Our results reveal restrictions and features for CAF transcriptional targeting.

Gene expression of microbial gelatinase activity for porcine gelatine identification.

In order to invent a porcine gelatine detection device using microbial resources, bacterial enzymes with a preference towards porcine gelatine and their candidate genes were evaluated. Five (n = 5) bacterial strains isolated from hot spring water and wet clay, Malaysia were screened for their gelatinase activity. The gelatinase enzyme was extracted and purified using ammonium sulphate precipitation prior to performing gelatinase assay on porcine, bovine and fish gelatine medium substrates. The G2 strain or Enterobacter aerogenes (Strain EA1) was selected for whole genome sequenced after showing a consistent trend of preference towards porcine gelatine. The gelatinase candidate gene gelEA1_9 was cloned and expressed. Based on one-way analysis of variance (ANOVA) with POST-HOC Duncan test (α = 0.05), the final product of gelEA1_9 was identified as a novel gelatinase. This gelatinase presented no significant difference in activity towards porcine gelatine. Hence, the present study demonstrated an enzyme-substrate interaction for porcine gelatine identification.

High expression of fibroblast activation protein (FAP) predicts poor outcome in high-grade serous ovarian cancer.

BACKGROUND: High-grade serous ovarian cancer (HGSOC) is a fatal form of ovarian cancer. Previous studies indicated some potential biomarkers for clinical evaluation of HGSOC prognosis. However, there is a lack of systematic analysis of different expression genes (DEGs) to screen and detect significant biomarkers of HGSOC. METHODS: TCGA database was conducted to analyze relevant genes expression in HGSOC. Outcomes of candidate genes expression, including overall survival (OS) and progression-free survival (PFS), were calculated by Cox regression analysis for hazard rates (HR). Histopathological investigation of the identified genes was carried out in 151 Chinese HGSOC patients to validate gene expression in different stages of HGSOC. RESULTS: Of all 57,331 genes that were analyzed, FAP was identified as the only novel gene that significantly contributed to both OS and PFS of HGSOC. In addition, FAP had a consistent expression profile between carcinoma-paracarcinoma and early-advanced stages of HGSOC. Immunological tests in paraffin section also confirmed that up-regulation of FAP was present in advanced stage HGSOC patients. Prediction of FAP network association suggested that FN1 could be a potential downstream gene which further influenced HGSOC survival. CONCLUSIONS: High-level expression of FAP was associated with poor prognosis of HGSOC via FN1 pathway.

The role of fibroblast activation protein in health and malignancy.

Fibroblast activation protein-α (FAP) is a type-II transmembrane serine protease expressed almost exclusively to pathological conditions including fibrosis, arthritis, and cancer. Across most cancer types, elevated FAP is associated with worse clinical outcomes. Despite the clear association between FAP and disease severity, the biological reasons underlying these clinical observations remain unclear. Here we review basic FAP biology and FAP's role in non-oncologic and oncologic disease. We further explore how FAP may worsen clinical outcomes via its effects on extracellular matrix remodeling, intracellular signaling regulation, angiogenesis, epithelial-to-mesenchymal transition, and immunosuppression. Lastly, we discuss the potential to exploit FAP biology to improve clinical outcomes.

FAP-specific PET signaling shows a moderately positive correlation with relative CBV and no correlation with ADC in 13 IDH wildtype glioblastomas.

OBJECTIVES: Targeting Fibroblast Activation Protein (FAP) is a new approach for glioblastoma imaging. In a recent pilot study glioblastomas showed elevated tracer uptake with high intratumoral heterogeneity in projection on the corresponding T2w/FLAIR and contrast enhanced MRI lesions. In this study, we correlated FAP-specific signaling with apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) signals in MRI to further characterize the significance of FAP uptake. METHODS: Clinical PET/CT scans of 13 glioblastoma patients were performed post i. v. administration of 68Ga-labelled-FAP-specific tracer molecules. PET- and corresponding MRI-scans were co-registrated. 3d volumetric segmentations were performed of T2w/FLAIR lesions and contrast enhancing lesions within co-registrated MRI slides. Signal intensity values of FAP-specific PET signaling, ADC and rCBV were analyzed for their pixel wise correlation in each patient. Pooled estimates of the correlation coefficients were calculated by using the Fisher z-transformation. RESULTS: FAP-specific PET signals showed a moderately positive correlation with rCBV values which is more pronounced within the T2w/FLAIR lesion (pooled correlation 0,229) than in the contrast enhancing tumor region (pooled correlation 0.09). FAP-specific PET signals showed no correlation with ADC values. CONCLUSIONS: The moderately positive correlation of FAP-specific signals with rCBV values in MRI indicates that FAP-signaling is not independent from perfusion, but also does not only reflect intratumoral perfusion differences. The missing correlation of FAP-specific signals with ADC indicates that FAP-specific imaging does not reflect cell density, but the spot-like expression of FAP in glioblastomas. The clinical value of FAP-specific imaging needs further investigation.

MiR-30a suppresses metastasis of gastric adenocarcinoma via targeting FAPα.

BACKGROUND: Gastric cancer is one of the leading causes of death worldwide. MicroRNA-30a (miR-30a) has been demonstrated to be involved in several types of cancer development. OBJECTIVE: We aimed to identify the molecular mechanism of miR-30a in gastric cancer. METHODS: We investigated the expression of miR-30a in gastric cancer tissues by qRT-PCR. The role of miR-30a on the metastasis and proliferation of gastric cancer was evaluated by cell migration assay, CCK-8 assay and tumor peritoneal dissemination model. The target of miR-30a in gastric cancer was identified. RESULTS: We discovered that miR-30a was significantly downregulated in gastric cancer tissues compared with adjacent nonmalignant tissues. The expression of miR-30a was inversely correlated with progression of gastric cancer. Gain- and loss-of function revealed that miR-30a acted as a potent tumor suppressor in gastric cancer. Re-expressed miR-30a inhibited gastric cancer cells migration, knock down miR-30a have the opposite effects. Furthermore, overexpression of miR-30a suppressed tumor peritoneal dissemination in vivo. We identified that fibroblast activation protein α (FAPα) was a direct target of miR-30a. The relative expression of FAPα was significantly higher in gastric cancer tissues compared with adjacent nonmalignant tissues. Inhibition of FAPα could recapitulate the effects of miR-30a, and overexpression of FAPα could abrogate the effect of miR-30a. CONCLUSION: MiR-30a inhibited gastric cancer metastasis by targeting FAPα, suggesting that miR-30a may function as a novel tumor suppressor in gastric cancer.

Whole Exome Sequencing Reveals a Novel Damaging Mutation in Human Fibroblast Activation Protein in a Family with Esophageal Squamous Cell Carcinoma.

PURPOSE: Esophageal squamous cancer cell (ESCC), with late diagnosis and poor rate of survival, is a significant cause of mortality in the developing countries. The hypothesis of rare high penetrance with mutations in new genes may explain the underlying predisposition in some of these familial cases. METHODS: Exome sequencing was performed in the patients with ESCC with strong disease aggregation, two sisters with ESCC cancer, and one with breast cancer. Data analysis selected only very rare variants (0-0.1%) located in genes with a role compatible with cancer. In addition, the homology modeling of the novel mutation (A459D) discovered in FAP gene was performed by using the online Swiss-Prot server for automated modeling and the resulted structure has been modified and analyzed by using bioinformatics software to thoroughly study the structural deficiencies caused by the novel mutation. RESULTS: Ten final candidate variants were selected and six genes validated by Sanger sequencing. Correct family segregation and somatic studies were used to categorize the most interesting variants in FAP, BOD1L, RAD51, Gasdermin D, LGR5, and CERS4. A novel, human mutation C1367A encoding Ala459 Asp (accession number: KT988039), occurring in the blade of the ß propeller domain, was identified in two sisters with ESCC. CONCLUSIONS: We identified novel mutations in three drug delivery genes, a tumor suppressor and also a stem cell marker of esophageal that may have a role in cancer treatment and are involved in cellular pathways, which supports their putative involvement in germ-line predisposition to this neoplasm.

Anti-tumour effects of a xenogeneic fibroblast activation protein-based whole cell tumour vaccine in murine tumour models.

The clinical benefit of cancer immunotherapy, including tumour vaccines, is influenced by immunosuppressive factors in the tumour microenvironment. Among these factors, cancer-associated fibroblasts (CAFs) and their products, such as fibroblast activation protein-α (FAPα), greatly affect tumourigenesis, development, metastasis and treatment tolerance, which make them promising immunotherapy targets for cancer patients. Our previous study reported that a whole cell tumour vaccine (WCTV) expressing FAPα inhibited tumour growth by simultaneously attacking cancer cells and CAFs. This study aimed to improve WCTVs with xenoantigens to end immune tolerance and to further activate the adaptive immune system. In the present study, we designed a WCTV by transducing a vector encoding human FAPα (hFAPα) into murine tumour cells and evaluated its efficacy in multiple solid tumour models. Immunotherapy with this WCTV effectively delayed tumour growth and prevented recurrence. The anti-tumour responses were clearly linked to antigen-specific cytotoxic T cells, whereas CD4(+) T lymphocytes also played a role. Humoural immune responses were activated because the adoptive transfer of immunoglobulins induced abscopal anti-tumour effects, and autoantibodies against FAPα were specifically detected in the sera of immunized mice. Moreover, an increased number of apoptotic tumour cells along with a reduced number of CAFs within the tumours suggest that xenogeneic FAPα-based WCTV has the potential to drive T cell and antibody responses against cancer cells and CAFs. This finding could offer an advanced strategy to treat multiple solid tumours with individualized cancer immunotherapy techniques.

Fibroblastic FAP promotes intrahepatic cholangiocarcinoma growth via MDSCs recruitment.

Desmoplasia is a hallmark of intrahepatic cholangiocarcinoma (ICC), which constitutes a barrier to infiltration of lymphocyte, but not myeloid cells. Given that dense desmoplastic stroma has been reported to be a barrier to infiltration of lymphocyte, but not myeloid cells. We here investigated whether fibroblastic FAP influenced ICC progression via non-T cell-related immune mechanisms. We demonstrated fibroblastic FAP expression was critical for STAT3 activation and CCL2 production, and ICC-CAFs were the primary source of CCL2 in human ICC microenvironment by using ICC-Fbs from six ICC patients. Fibroblastic knockdown of FAP significantly impaired the ability of ICC-CAFs to promote ICC growth, MDSCs infiltration and angiogenesis, which was restored by adding exogenous CCL2. Furthermore, interestingly, the tumor-promoting effect of fibroblastic FAP is dependent on MDSCs via secretion of CCL2, as depletion of Gr-1+ cells reversed the restoring effects of exogenous CCL2 on tumor growth and angiogenesis. In vitro migration assay confirmed that exogenous CCL2 could rescue the impaired ability of ICC-Fbs to attract Gr-1+ cells caused by fibroblastic FAP knockdown. In contrast, fibroblastic FAP knockdown had no effect on ICC cell proliferation and apoptotic resistance. Depletion MDSCs by anti-Gr-1 monoclonal antibody in subcutaneous transplanted tumor model abrogated tumor promotion by ICC-CAFs suggested that the pro-tumor function of Fibroblastic FAP relied on MDSCs. Mechanical, flow cytometry and chamber migration assay were conducted to find Fibroblastic FAP was required by the ability of ICC-CAFs to promote MDSC migration directly. Moreover, fibroblastic FAP knockdown had no effect on cell proliferation and apoptotic resistance. Here, we revealed the T-cell independent mechanisms underlying the ICC-promoting effect of fibroblastic FAP by attracting MDSCs via CCL2, which was mainly attributed to the ability of FAP to attract MDSCs and suggests that specific targeting fibroblastic FAP may represent a promising therapeutic strategy against ICC.

Bioluminescent Probe for Monitoring Endogenous Fibroblast Activation Protein-Alpha.

Fibroblast activation protein-α (FAP), as a crucial member of cell surface glycoprotein, highly expresses in reactive fibroblasts of tumors and several fibrosis diseases. It is a potential target for drug design and also reported as a prodrug strategy to increase the therapeutic window of some anticancer agents. In this work, we developed the first bioluminogenic probe for FAP with a limit-of-detection of 0.254 ng/mL, which could be applied to evaluate the FAP inhibitors in vitro. The experiments of transgenic mice and tumor-bearing nude mice validated our probe 1 could reflect the endogenous FAP level in vivo. Furthermore, this probe was successfully used to reflect FAP up-regulation in the lung homogenates of the bleomycin-induced idiopathic pulmonary fibrosis mice.

Transcripto-based network analysis reveals a model of gene activation in tongue squamous cell carcinomas.

BACKGROUND: Tongue squamous cell carcinoma (TSCC) is the most common malignant tumor derived from the oral cavity, yet its specific molecular mechanisms have not been fully clarified. The aim of this study was to evaluate the association between potential genes and clinical features through constructing gene co-expression networks. METHODS: The weighted gene co-expression network analysis was used to construct gene co-expression networks and to identify candidate key modules and hub genes. The gene expression profiles of GSE31056 obtained from the Gene Expression Omnibus (GEO) database was used to construct co-expression networks. RESULTS: Five hub genes (FAP, AGTRAP, PLOD1, POSTN, and TSHZ3) were identified and validated at transcriptional levels. Moreover, the protein levels of these five hub genes were also found significantly higher in tumor tissues. Among them, FAP was most associated with immune infiltration. CONCLUSIONS: These five candidate biomarkers and therapeutic targets are worthy of further investigation and discussion.