Eosinophils regulate intra-adipose axonal plasticity.

Sympathetic innervation regulates energy balance, and the nerve density in the adipose tissues changes under various metabolic states, resulting in altered neuronal control and conferring resilience to metabolic challenges. However, the impact of the immune milieu on neuronal innervation is not known. Here, we examined the regulatory role on nerve plasticity by eosinophils and found they increased cell abundance in response to cold and produced nerve growth factor (NGF) in the white adipose tissues (WAT). Deletion of Ngf from eosinophils or depletion of eosinophils impairs cold-induced axonal outgrowth and beiging process. The spatial proximity between sympathetic nerves, IL-33-expressing stromal cells, and eosinophils was visualized in both human and mouse adipose tissues. At the cellular level, the sympathetic adrenergic signal induced calcium flux in the stromal cells and subsequent release of IL-33, which drove the up-regulation of IL-5 from group 2 innate lymphoid cells (ILC2s), leading to eosinophil accretion. We propose a feed-forward loop between sympathetic activity and type 2 immunity that coordinately enhances sympathetic innervation and promotes energy expenditure.

Synergistic induction of tertiary lymphoid structures by chemoimmunotherapy in bladder cancer.

BACKGROUND: A substantial number of patients with bladder cancer fail to benefit from immune checkpoint inhibitors (ICIs). We aim to investigate whether the addition of other therapeutic modalities into immunotherapy may augment the immune reactivity, thereby improving the overall response rate. METHODS: We conducted a comprehensive assessment of the immunological changes following immunotherapy and chemotherapy, employing both single-cell RNA sequencing and bulk RNA sequencing analyses. RESULTS: The bladder cancer patient treated with ICIs exhibited a higher abundance of B cells and T follicular helper cells compared to the treatment-naïve patient. Analysis of public datasets and the in-house RJBLC-I2N003 cohort revealed the induction of tertiary lymphoid structure (TLS) neogenesis and maturation by immunotherapy. The IMvigor 210 study suggested that TLS could serve as a predictor of immunotherapy response and patient prognosis. In addition, genome-wide transcriptome data unveiled a shift towards the immune-enriched subtype over the desert subtype in patients receiving neoadjuvant chemotherapy. Notably, the proportions of CD20 + B cells, T follicular helper cells, and TLSs were significantly increased. In patients treated with a combination of neoadjuvant chemotherapy and ICIs, TLS positivity and maturity were improved compared to the baseline. Furthermore, neoadjuvant chemoimmunotherapy resulted in a higher rate of pathological complete response compared to monotherapies. CONCLUSIONS: This work pinpointed the individual effect of immunotherapy and chemotherapy in fostering TLS development, and underscored the superior effectiveness of combined modalities in enhancing TLS maturation and response rates.

Integrated longitudinal circulating tumor DNA profiling predicts immunotherapy response of metastatic urothelial carcinoma in the POLARIS-03 trial.

Non-invasive biomarkers for immunotherapy response remain a compelling unmet medical need. POLARIS-03 is a multicenter phase II trial to evaluate the safety and efficacy of toripalimab (anti-programmed cell death 1) in refractory metastatic urothelial carcinoma (mUC). We assessed the predictive utility of longitudinal circulating tumor DNA (ctDNA) analysis from a single-institution biomarker cohort. Twenty-seven mUC patients receiving toripalimab (3 mg/kg Q2W) at Ren Ji Hospital were enrolled. Serial plasma specimens were obtained at baseline and then every two cycles during treatment. The 600-gene panel (PredicineATLAS™) liquid biopsy assay was applied to probe somatic variants and cancer cell fraction (CCF). Low-pass whole genome sequencing was used to determine the copy number abnormality (CNA) score. Across the entire cohort, we observed different degrees of concordance between somatic aberrations detected by ctDNA and those inferred by matched tumor samples. Although the baseline CCF or CNA had limited predictive value, early ctDNA response at week 8 was associated with toripalimab efficacy and prolonged patient survival. Integrating CCF and CNA decrease achieved a superior accuracy of 90.5% in classifying responders and non-responders and predicted long-term benefit from toripalimab. Dynamic changes in the CCF and CNA in blood exquisitely reflected radiographic assessment of malignant lesions, including those with FGFR3-TACC3 gene fusion or microsatellite instability. This study demonstrates the feasibility and effectiveness of integrated longitudinal ctDNA profiling as a potential biomarker in mUC patients undergoing immunotherapy and supports further clinical evaluation of minimally invasive liquid biopsy assays for treatment stratification and therapy monitoring. © 2023 The Pathological Society of Great Britain and Ireland.

A phosphoglycerate mutase 1 allosteric inhibitor overcomes drug resistance to EGFR-targeted therapy via disrupting IL-6/JAK2/STAT3 signaling pathway in lung adenocarcinoma.

Resistance to epidermal growth factor receptor (EGFR) inhibitors, from the first-generation erlotinib to the third generation osimertinib, is a clinical challenge in the treatment of patients with EGFR-mutant lung adenocarcinoma. Our previous work found that a novel allosteric inhibitor of phosphoglycerate mutase 1 (PGAM1), HKB99, restrains erlotinib resistance in lung adenocarcinoma cells. However, the role of HKB99 in osimertinib resistance and its underlying molecular mechanism remains to be elucidated. Herein, we found that IL-6/JAK2/STAT3 signaling pathway is aberrantly activated in both erlotinib and osimertinib resistant cells. Importantly, HKB99 significantly blocks the interaction of PGAM1 with JAK2 and STAT3 via the allosteric sites of PGAM1, which leads to inactivation of JAK2/STAT3 and thereby disrupts IL-6/JAK2/STAT3 signaling pathway. Consequently, HKB99 remarkably restores EGFR inhibitor sensitivity and exerts synergistic tumoricidal effect. Additionally, HKB99 alone or in combination with osimertinib down-regulated the level of p-STAT3 in xenograft tumor models. Collectively, this study identifies PGAM1 as a key regulator in IL-6/JAK2/STAT3 axis in the development of resistance to EGFR inhibitors, which could serve as a therapeutic target in lung adenocarcinoma with acquired resistance to EGFR inhibitors.

APOBEC3B stratifies ovarian clear cell carcinoma with distinct immunophenotype and prognosis.

BACKGROUND: Ovarian clear cell carcinoma (OCCC) is a challenging disease due to its intrinsic chemoresistance. Immunotherapy is an emerging treatment option but currently impeded by insufficient understanding of OCCC immunophenotypes and their molecular determinants. METHODS: Whole-genome sequencing on 23 pathologically confirmed patients was employed to depict the genomic profile of primary OCCCs. APOBEC3B expression and digital pathology-based Immunoscore were assessed by performing immunohistochemistry and correlated with clinical outcomes. RESULTS: An APOBEC-positive (APOBEC+) subtype was identified based on the characteristic mutational signature and prevalent kataegis events. APOBEC + OCCC displayed favourable prognosis across one internal and two external patient cohorts. The improved outcome was ascribable to increased lymphocytic infiltration. Similar phenomena of APOBEC3B expression and T-cell accumulation were observed in endometriotic tissues, suggesting that APOBEC-induced mutagenesis and immunogenicity could occur early during OCCC pathogenesis. Corroborating these results, a case report was presented for an APOBEC + patient demonstrating inflamed tumour microenvironment and clinical response to immune checkpoint blockade. CONCLUSIONS: Our findings implicate APOBEC3B as a novel mechanism of OCCC stratification with prognostic value and as a potential predictive biomarker that may inform immunotherapeutic opportunities.

Consolidation radiographic morphology can be an indicator of the pathological basis and prognosis of partially solid nodules.

BACKGROUND: Part-solid nodules (PSNs) have gradually shifted to defining special clinical subtypes. Commonly, the solid portions of PSNs show various radiological morphologies, of which the corresponding pathological basis and prognosis are unclear. We conducted a radiological-pathological evaluation to determine the histopathologic basis of different consolidation radiographic morphologies related to prognosis. MATERIALS AND METHODS: A cohort of 275 patients with a surgical pathological diagnosis of lung adenocarcinoma were enrolled. Preoperative computed tomography (CT) images of the PSNs were recorded and assessed. A panel of 103 patients with complete pathological specimens was selected to examine the radiological-pathological associations, and follow-up was performed to identify the prognosis. RESULTS: Of the 275 patients, punctate consolidation was observed radiologically in 43/275 (15.7%), stripe consolidation in 68/275 (24.7%), and irregular consolidation in 164/275 (59.6%) patients. The radiological morphology of the solid components was significantly associated with the histopathological subtypes (P < 0.001). Visual punctate solid components on CT correlated with tertiary lymphoid structures, stripe solid components on CT correlated with fibrotic scar, and irregular solid components on CT correlated with invasion. PSNs with regular consolidation had a better prognosis than those with irregular consolidation. CONCLUSION: Radiological morphology of solid components in PSNs can indicate the pathological basis and is valuable for prognosis. In particular, irregular solid components in PSNs usually indicate serious invasive growth, which should be taken with caution during assessment.

Baseline immunity and impact of chemotherapy on immune microenvironment in cervical cancer.

BACKGROUND: We aimed to comprehensively evaluate the immunologic landscape at baseline and upon chemotherapy in cervical cancer. The information should aid ongoing clinical investigations of checkpoint blockade immunotherapies in this disease setting. METHODS: A series of 109 cervical carcinoma patients was retrospectively assayed before and after neoadjuvant chemotherapy. Tumour-infiltrating immune markers (CD3, CD4, CD8, CD20, CD56, CD68, PD-1, PD-L1) were assessed by immunohistochemistry. RNA sequencing analysis was performed on matched pre- and post-treatment fresh-frozen tissues. RESULTS: At diagnosis, diverse immune cell types including CD20+ B cells, CD3+ T cells, CD56+ natural killer (NK) cells, and CD68+ macrophages were detected in different proportions of cervical carcinoma. Unsupervised hierarchical clustering evidently showed that CD4+ and CD8+ T cell abundance correlated with PD-L1 expression. Based on the immune infiltration patterns, the patients could be stratified into four groups with prognostic relevance, namely, 'immuno-active', 'immuno-medial', 'immuno-NK', and 'immuno-deficient'. Neoadjuvant chemotherapy was associated with increased CD4, CD8, CD20, and CD56 signals, most prominently in good responders. Transcriptomic data corroborated the improved anticancer immunity and identified immunosuppressive CD200 upregulation following chemotherapeutic intervention. CONCLUSIONS: A subset of cervical cancer harbours active immune microenvironment, and chemotherapy treatment may further exert locoregional immunostimulation. Immune checkpoint inhibitors as combination or maintenance therapies warrant future exploration in clinic.

Urinary Molecular Pathology for Patients with Newly Diagnosed Urothelial Bladder Cancer.

PURPOSE: Next-generation sequencing (NGS)-based profiling of both urinary tumor DNA (utDNA) and circulating tumor DNA (ctDNA) shows promise for noninvasive detection and surveillance of urothelial bladder cancer (UBC). However, the analytical performance of these assays remains undefined in the real-world setting. Here, we sought to evaluate the concordance between tumor DNA (tDNA) profiling and utDNA or ctDNA assays using a UBC patient cohort from the intended-use population. MATERIALS AND METHODS: Fifty-nine cases with pathologically confirmed disease and matching tissue/urine pairs were prospectively enrolled. Baseline peripheral blood mononuclear cell and plasma specimens were collected during clinic visits. The PredicineCARETM NGS assay was applied for ultra-deep targeted sequencing and somatic alteration identification in tDNA, utDNA and ctDNA. RESULTS: Diverse quantitative metrics including cancer cell fraction, variant allele frequency and tumor mutation burden were invariably concordant between tDNA and utDNA, but not ctDNA. The mutational landscapes captured by tDNA or utDNA were highly similar, whereas a considerable proportion of ctDNA aberrations stemmed from clonal hematopoiesis. Using tDNA-informed somatic events as reference, utDNA assays achieved a specificity of 99.3%, a sensitivity of 86.7%, a positive predictive value of 67.2%, a negative predictive value of 99.8% and a diagnostic accuracy of 99.1%. Higher preoperative utDNA or tDNA abundance correlated with worse relapse-free survival. Actionable variants including FGFR3 alteration and ERBB2 amplification were identified in utDNA. CONCLUSIONS: Urine-based molecular pathology provides a valid and complete genetic profile of bladder cancer, and represents a faithful surrogate for genotyping and monitoring newly diagnosed UBC.

Radiographic features and prognosis of early- and late-onset non-small cell lung cancer immune checkpoint inhibitor-related pneumonitis.

BACKGROUND: Immunotherapy is becoming a standard of care for non-small cell lung cancer (NSCLC). Checkpoint inhibitor-associated pneumonia (CIP) is a rare and potentially life-threatening event that can occur at any time during tumor immunotherapy. However, there may be differences in the radiological patterns and prognosis of CIP during different periods. This study aimed to investigate the radiographic features and prognosis of early- and late-onset immune-related pneumonitis. METHODS: We retrospectively analyzed the clinical data of 677 NSCLC patients receiving immunotherapy to identify 32 patients with CIP, analyzed the clinical and radiographic data, and summarized the radiological features and prognosis of early- and late-onset CIP. RESULTS: CIP had an incidence of 4.7%, a median onset time of 10 weeks, and a mortality of 28.1%. Among these, CIP included 14 early-onset cases, where grade ≥ 3 CIP accounted for 92.9%, main radiographic pattern was organizing pneumonia (OP)-like pattern, and mortality was 50.0%. We also identified 18 late-onset CIPs, where grade ≥ 3 CIP accounted for 50.0%, main radiographic pattern was nonspecific interstitial pneumonia (NSIP)-like pattern, and mortality was 11.1%. The overall survival rate of the early-onset group was significantly lower than that of the late-onset group (P < 0.05). CONCLUSION: Early-onset CIP cases were higher in the Common Terminology Criteria for Adverse Events (CTCAE v5.0) grade and mainly presented with an OP-like radiographic pattern; whereas, late-onset CIP cases were lower in CTCAE grade and mainly presented with an NSIP-like radiographic pattern. Finally, the prognosis of the early-onset CIP group was poorer than that of the late-onset CIP group. We believe that this study will be helpful for clinicians for making early diagnosis and deciding treatment modalities for patients with CIP.

T-cell exhaustion interrelates with immune cytolytic activity to shape the inflamed tumor microenvironment.

Direct quantification of exhausted T cells in human cancer is lacking, and its predictive value for checkpoint-based treatment remains poorly investigated. We sought to systematically characterize the pan-cancer landscape and molecular hallmarks of T-cell dysfunction for the purpose of precision immunotherapy. Here, we defined a transcriptional signature for T-cell exhaustion through analyzing differential gene expression between PD-1-high and PD-1-negative CD8+ T lymphocytes from primary non-small cell lung cancer (NSCLC), followed by positive correlation tests with PDCD1 in TCGA lung carcinomas. A 78-gene signature for exhausted CD8+ T cells (GET) was identified and validated to reflect dysfunctional immune state spanning different species and disease models. We discovered that GET estimation significantly correlated with intratumoral immune cytolytic activity (CYT) and T-cell-inflamed gene expression profile (GEP) across 30 solid tumor types. Miscellaneous tumor-intrinsic and -extrinsic properties, in particular leukocyte proportions, genomic abnormalities, specific mutational signatures, and signaling pathways, were notably associated with GET levels. Furthermore, higher GET expression predicted an increased likelihood of clinical response to immune checkpoint inhibitors. These findings highlight the interrelation between T-cell exhaustion and immune cytolytic activity at the pan-cancer scale. The resulting inflamed tumor microenvironment may further crosstalk with other molecular and clinicopathological factors, which should be properly considered during immunotherapy biomarker development. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

HKB99, an allosteric inhibitor of phosphoglycerate mutase 1, suppresses invasive pseudopodia formation and upregulates plasminogen activator inhibitor-2 in erlotinib-resistant non-small cell lung cancer cells.

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as erlotinib, remains a major challenge in the targeted therapy of non-small cell lung cancer (NSCLC). HKB99 is a novel allosteric inhibitor of phosphoglycerate mutase 1 (PGAM1) that preferentially suppresses cell proliferation and induces more apoptosis in acquired erlotinib-resistant HCC827ER cells compared with its parental HCC827 cells. In this study we identified the molecular biomarkers for HKB99 response in erlotinib-resistant HCC827ER cells. We showed that HCC827ER cells displayed enhanced invasive pseudopodia structures as well as downregulated plasminogen activator inhibitor-2 (PAI-2). Meanwhile, PAI-2 knockdown by siPAI-2 candidates decreased the sensitivity of HCC827 parental cells to erlotinib. Moreover, HKB99 (5 µM) preferentially inhibited the invasive pseudopodia formation and increased the level of PAI-2 in HCC827ER cells. Collectively, this study provides new insight into the role of PAI-2 in regulating the sensitivity of erlotinib resistant NSCLC cells to PGAM1 inhibitor. Furthermore, PAI-2 level might be considered as a potential biomarker for predicting the efficacy of the PGAM1 allosteric inhibitor on the erlotinib resistant NSCLC cells.

Multiregion whole-genome sequencing depicts intratumour heterogeneity and punctuated evolution in ovarian clear cell carcinoma.

BACKGROUND: Ovarian clear cell carcinoma (OCCC) arises from endometriosis and represents a difficult-to-treat gynaecological malignancy, in part, because its spatial intratumour heterogeneity and temporal evolutionary trajectories have not been explicitly defined. METHODS: We performed whole-genome sequencing on six pathologically confirmed patients with OCCC. An R package named KataegisPortal was developed to identify and annotate loci of localised hypermutations. Immunohistochemical staining was conducted on a tissue microarray containing 143 OCCC specimens. RESULTS: Multiregion analysis demonstrated considerable degrees of subclonal diversification, ascribable to dynamic mutagenic processes, as well as macroevolutionary events including the acquisition of aneuploidy and chromoplexy. KataegisPortal unveiled APOBEC-mediated kataegis in the early phases of OCCC pathogenesis. We further showed evidence that APOBEC3A and APOBEC3B were frequently expressed in OCCC and possibly regulated by the MAPK pathway. Notably, APOBEC3B-expressing OCCC displayed favourable prognosis and appreciable immunogenicity manifested by marked cytotoxic T-cell infiltration. CONCLUSIONS: These results point to an appealing model of punctuated tumour evolution underlying OCCC neoplastic transformation and progression, which may pose formidable challenges of early detection and intervention, and indicate the intratumour heterogeneity of cancer-driving alterations, yielding important implications for molecular diagnosis and targeted treatment of this lethal disease.

Clinicopathological, microenvironmental and genetic determinants of molecular subtypes in KEAP1/NRF2-mutant lung cancer.

Somatic KEAP1-NRF2 pathway alterations are frequently detected in both lung adenocarcinomas and squamous cell carcinomas. However, the biological characteristics and molecular subtypes of KEAP1/NRF2-mutant lung cancer remain largely undefined. Here, we performed a stepwise, integrative analytic and experimental interrogation of primary tumors and cancer cell lines harboring KEAP1 or NFE2L2 (encoding NRF2) gene mutations. First, we discovered that KEAP1/NRF2-mutant lung cancer presented APOBEC-mediated mutational signatures, impaired tumor angiogenesis, elevated hypoxic stress and deficient immune-cell infiltrates. Second, gene expression-based subtyping revealed three molecular subsets of KEAP1/NRF2-mutant lung adenocarcinomas and two molecular subsets of KEAP1/NRF2-mutant lung squamous cell carcinomas, each associated with distinguishing genetic, differentiation, immunological and clinicopathological properties. Third, single-sample prediction allowed for de novo identification of KEAP1/NRF2-active tumors within KEAP1/NRF2-wild-type samples. Our data demonstrate that KEAP1/NRF2-mutant lung cancer is a microenvironmentally distinct, biologically heterogeneous, and clinically underestimated disease. These new pathological and molecular insights may accelerate the development of efficacious therapeutic strategies against human malignancies featured by KEAP1-NRF2 pathway activation.

Prevalence and clonality of synchronous primary carcinomas in the bladder and prostate.

Incidental prostate adenocarcinoma (IPCa) has been frequently discovered during postoperative histopathological evaluation of radical cystoprostatectomy specimens in patients with bladder cancer (BCa). However, there is currently no conclusive study addressing the clinical significance of IPCa and the clonal relatedness of IPCa and BCa. Here, we performed a retrospective single-center review of 919 BCa cases and an additional meta-analysis including a total of 19 868 individuals who underwent radical cystectomy for bladder cancer. IPCa, mostly clinically insignificant, was detected in 67 of 919 BCa patients (7.3%) and was significantly associated with greater age. In the meta-analysis, a lower prevalence was observed in Asian than in non-Asian countries (19% versus 32%), presumably due to their different rates of prostate cancer occurrence. Whole-exome sequencing on matched BCa and IPCa samples unambiguously revealed independent clonal origins of the synchronous tumors. BCa and IPCa lesions from each patient displayed distinctive genomic abnormalities and largely unrelated mutational signatures of single nucleotide variations, indicating disparate mutational processes underlying bladder and prostate oncogenesis. These findings provide important insights into the incidental nature of prostate adenocarcinoma in patients with bladder cancer, and suggest that the two concurrent diseases can be managed separately. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A candidate gastric stem/progenitor cell marker revealed by genome-wide analysis.

Despite the important role of the gastric stem cell in tissue homeostasis and gastric carcinogenesis, its residence and identity remain poorly understood. In a recent paper in The Journal of Pathology, Vange et al suggest ASPM as a candidate stem/progenitor cell marker for oxyntic glands. Identification of ASPM was achieved by genome-wide gene expression analysis of the micro-dissected isthmus zone, where the majority of stem/progenitor cells are believed to reside. ASPM-positive cells, scattered in the proliferative isthmus region, do not express most differentiated cell markers and are largely quiescent. Together with ASPM, 11 other genes that are uniquely expressed in the isthmus zone constitute a regulatory network downstream of the core transcription factor E2F1. The authors further demonstrated that up-regulation of E2F1 and ASPM is associated with gastric cancers. This study provides novel candidates for future lineage-tracing experiments that will lead to the ultimate discovery of bona fide gastric stem cell markers. Additionally, the E2F1-ASPM axis may represent a new mechanism for gastric carcinogenesis.

Tumour-secreted miR-9 promotes endothelial cell migration and angiogenesis by activating the JAK-STAT pathway.

Angiogenesis plays a crucial role during tumorigenesis and much progress has been recently made in elucidating the role of VEGF and other growth factors in the regulation of angiogenesis. Recently, microRNAs (miRNAs) have been shown to modulate a variety of physiogical and pathological processes. We identified a set of differentially expressed miRNAs in microvascular endothelial cells co-cultured with tumour cells. Unexpectedly, most miRNAs were derived from tumour cells, packaged into microvesicles (MVs), and then directly delivered to endothelial cells. Among these miRNAs, we focused on miR-9 due to the strong morphological changes induced in cultured endothelial cells. We found that exogenous miR-9 effectively reduced SOCS5 levels, leading to activated JAK-STAT pathway. This signalling cascade promoted endothelial cell migration and tumour angiogenesis. Remarkably, administration of anti-miR-9 or JAK inhibitors suppressed MV-induced cell migration in vitro and decreased tumour burden in vivo. Collectively, these observations suggest that tumour-secreted miRNAs participate in intercellular communication and function as a novel pro-angiogenic mechanism.

Oncogenic RAS pathway activation promotes resistance to anti-VEGF therapy through G-CSF-induced neutrophil recruitment.

Granulocyte-colony stimulating factor (G-CSF) promotes mobilization of CD11b(+)Gr1(+) myeloid cells and has been implicated in resistance to anti-VEGF therapy in mouse models. High G-CSF production has been associated with a poor prognosis in cancer patients. Here we show that activation of the RAS/MEK/ERK pathway regulates G-CSF expression through the Ets transcription factor. Several growth factors induced G-CSF expression by a MEK-dependent mechanism. Inhibition of G-CSF release with a MEK inhibitor markedly reduced G-CSF production in vitro and synergized with anti-VEGF antibodies to reduce CD11b(+)Ly6G(+) neutrophil mobilization and tumor growth and led to increased survival in animal models of cancer, including a genetically engineered mouse model of pancreatic adenocarcinoma. Analysis of biopsies from pancreatic cancer patients revealed increased phospho-MEK, G-CSF, and Ets expression and enhanced neutrophil recruitment compared with normal pancreata. These results provide insights into G-CSF regulation and on the mechanism of action of MEK inhibitors and point to unique anticancer strategies.

Lin28B promotes melanoma growth by mediating a microRNA regulatory circuit.

It has been increasingly recognized that microRNAs (miRNAs) are often dysregulated in various human malignancies and can function as oncogenes or tumor-suppressors. However, the potential roles of miRNAs and components of the miRNA biogenesis pathway remain poorly defined in melanoma. Here, we systematically profiled miRNA expression in human melanocytes and melanoma cells, and identified a prominent function of miR-125a-5p in suppressing melanoma growth. Mechanistically, we discovered that Lin28B, a well-characterized inhibitor of let-7 miRNA biogenesis, was a direct target of miR-125a-5p in melanoma. We showed that the Lin28B was aberrantly expressed in a large proportion of melanoma patients and was functionally required for melanoma progression. We further demonstrated the involvement of let-7-dependent mechanism downstream of Lin28B, resulting in the activation of transforming growth factor-ß signaling cascade. Collectively, our data implicate Lin28B as a novel oncogene in melanomagenesis by mediating a miRNA regulatory circuit.

Expression of a functional VEGFR-1 in tumor cells is a major determinant of anti-PlGF antibodies efficacy.

PlGF, one of the ligands for VEGFR-1, has been implicated in tumor angiogenesis. However, more recent studies indicate that genetic or pharmacological inhibition of PlGF signaling does not result in reduction of microvascular density in a variety of tumor models. Here we screened 12 human tumor cell lines and identified 3 that are growth inhibited by anti-PlGF antibodies in vivo. We found that efficacy of anti-PlGF treatment strongly correlates with VEGFR-1 expression in tumor cells, but not with antiangiogenesis. In addition, PlGF induced VEGFR-1 signaling and biological responses in tumor cell lines sensitive to anti-PlGF, but not in refractory tumor cell lines or in endothelial cells. Also, genetic ablation of VEGFR-1 signaling in the host did not affect the efficacy of PlGF blockade. Collectively, these findings suggest that the role of PlGF in tumorigenesis largely consists of promoting autocrine/paracrine growth of tumor cells expressing a functional VEGFR-1 rather than stimulation of angiogenesis.

Sympathetic nerve-enteroendocrine L cell communication modulates GLP-1 release, brain glucose utilization, and cognitive function.

Glucose homeostasis is controlled by brain-gut communications. Yet our understanding of the neuron-gut interface in the glucoregulatory system remains incomplete. Here, we find that sympathetic nerves elevate postprandial blood glucose but restrict brain glucose utilization by repressing the release of glucagon-like peptide-1 (GLP-1) from enteroendocrine L cells. Sympathetic nerves are in close apposition with the L cells. Importantly, sympathetic denervation or intestinal deletion of the adrenergic receptor α2 (Adra2a) augments postprandial GLP-1 secretion, leading to reduced blood glucose levels and increased brain glucose uptake. Conversely, sympathetic activation shows the opposite effects. At the cellular level, adrenergic signaling suppresses calcium flux to limit GLP-1 secretion upon sugar ingestion. Consequently, abrogation of adrenergic signal results in a significant improvement in learning and memory ability. Together, our results reveal a sympathetic nerve-enteroendocrine unit in constraining GLP-1 secretion, thus providing a therapeutic nexus of mobilizing endogenous GLP-1 for glucose management and cognitive improvement.