Project description:Hepatoblastoma remains one of the most difficult childhood tumors to treat and is alarmingly understudied. Over half of patients initially present with locally advanced or metastatic disease and the prognosis for this cohort remains dismal. In addition, many of these children have disease that is resistant to standard therapies and will require novel and targeted therapies to effectively treat or manage their disease. We previously demonstrated that Proviral Insertion site in Maloney murine leukemia virus (PIM) kinases, specifically PIM3, are overexpressed in human hepatoblastoma cells and function to promote tumorigenesis. We aimed to use CRISPR/Cas9 gene editing technology with dual gRNAs to introduce large inactivating deletions in the PIM3 gene and achieve stable PIM3 knockout (KO) in the human hepatoblastoma cell line, HuH6. PIM3 KO of hepatoblastoma cells led to significantly decreased proliferation, viability, and motility, inhibited cell-cycle progression, decreased tumor growth in a xenograft murine model, and increased animal survival. Analysis of RNA sequencing data revealed that PIM3 KO downregulated expression of pro-migratory and pro-invasive genes and upregulated expression of genes involved in apoptosis and differentiation. Furthermore, PIM3 KO decreased hepatoblastoma cancer cell stemness as evidenced by decreased tumorsphere formation, decreased mRNA abundance of stemness markers, and decreased cell surface expression of CD133, a marker of hepatoblastoma stem cell-like cancer cells. Reintroduction of PIM3 into PIM3 KO cells rescued the malignant phenotype. These findings emphasize the role of PIM3 in promoting hepatoblastoma tumorigenesis and provide evidence that targeting PIM3 may offer a novel therapeutic approach for children with hepatoblastoma.
Project description:Background & Aims: Extracellular vesicles (EVs) play a pivotal role in connecting tumor cells and their local and distant microenvironment. Here, we aimed to understand the role and molecular basis of patient-derived EVs in modulating cancer stemness and tumorigenesis in the context of hepatocellular carcinoma (HCC). Methods: EVs were isolated, quantified and characterized from patients’ sera. EVs were tested vigorously, both in vitro and in vivo, by various functional assays. Proteomic analysis was performed to identify the functional components of EVs. The expression level of polymeric immunoglobulin receptor (pIgR) in circulating EVs, tumor and non-tumorous tissues of HCC patients was determined by ELISA, immunoblotting, immunohistochemistry and quantitative PCR. The functional role and underlying mechanism of EVs with an enhanced pIgR expression was elucidated. Blockage of EV-pIgR with neutralizing antibody was performed in nude mice implanted with patient-derived tumor xenograft (PDTX). Results: Circulating EVs of late-stage HCC (L-HCC) patient had significantly elevated pIgR expression when compared to the EVs released by control individuals. The augmenting effect of L-HCC patient in cancer stemness and tumorigenesis was hindered by anti-pIgR antibody. EVs enriched with pIgR consistently promoted cancer stemness and cancerous phenotypes in the recipient cells. Mechanistically, EV-pIgR-induced cancer aggressiveness was abrogated by Akt and β-catenin inhibitors, ascertaining the role of EV-pIgR through the activation of PDK1/Akt/GSK3β/β-catenin signaling axis. Furthermore, anti-pIgR neutralizing antibody attenuated the tumor growth in mice implanted with PDTX. Conclusion: The study illustrates an unrevealed role of EV-pIgR in regulating cancer stemness and aggressiveness, in which EV-pIgR activates PDK1/Akt/GSK3β/β-catenin signaling cascades. The blockage of intercellular communications mediated by EV-pIgR in the tumor microenvironment may provide a new therapeutic strategy for cancer patients.
Project description:We identify a new mechanism by which OLZ ameliorates chronic stress-enhanced tumorigenesis and chemoresistance. OLZ reversed chronic stress-enhanced lung tumorigenesis and anxiety-like behaviors by suppressing neuro-activity in the mPFC and reducing norepinephrine (NE) releasing. To investigate the mechanism of NE in cancer stemness we performed RNA-seq of the NCI-H1299 cells under NE treatment and found that NE activated β2-adrenoceptor (ADRB2)-mediated cAMP-PKA-CREB pathway to transactivate CLOCK that further sustains cancer stemness.
Project description:PurposeHepatoblastoma is the most common primary liver cancer of childhood and has few prognostic indicators. We have previously shown that Proviral Integration site for Moloney murine leukemia virus (PIM3) kinase decreased hepatoblastoma tumorigenicity. We sought to determine the effect of PIM3 overexpression on hepatoblastoma cells and whether expression of PIM3 correlated with patient/tumor characteristics or survival.MethodsThe hepatoblastoma cell line, HuH6, and patient-derived xenograft, COA67, were utilized. Viability, proliferation, migration, sphere formation, and tumor growth in mice were assessed in PIM3-overexpressing cells. Immunohistochemistry was performed for PIM3 on patient samples. Correlation between stain score and clinical/pathologic characteristics was assessed.ResultsPIM3 overexpression rescued the anti-proliferative effect observed with PIM3 knockdown. Sphere formation was increased in PIM3 overexpressing cells. Cells with PIM3 overexpression yielded larger tumors than those with empty vector. Seventy-four percent of samples expressed PIM3. There was no statistical difference in patient characteristics between subjects with strong versus weak PIM3 staining, but patients with strong PIM3 staining had decreased survival.ConclusionsPIM3 expression plays a role in hepatoblastoma tumorigenesis. PIM3 was present in the majority of hepatoblastomas and higher PIM3 expression correlated with decreased survival. PIM3 warrants investigation as a therapeutic target and prognostic marker for hepatoblastoma.
Project description:The mechanisms underlying hepatoblastoma are not well defined. To address this, we generated transcriptomic profiles of normal, background, and hepatoblastoma liver samples from patients aged 0.01 months to 6 years, using RNA-sequencing. Hepatoblasoma was histologically confirmed. Here we focus on the elevation of stem cell markers and the loss of tumor suppressor proteins leading to the development of hepatoblastoma in very young children.
Project description:Endothelial cells (ECs) form a tissue-specific barrier for disseminating cancer cells in distant organs. However, the molecular regulation of the ECs in the metastatic niche is poorly understood. Here, we analyzed the transcriptional reprogramming of ECs in the lung metastatic niche six hours after the arrival of melanoma cells in the niche. We discovered a novel EC cluster derived from venous capillaries in response to infiltrating cancer cells, which was enriched for cell-cell communication pathways, including the Dll4, Vegf and Il6-Jak-Stat pathways. The Jak-Stat activated oncogenic Pim3 kinase was a marker of the cancer responding ECs, being upregulated in spontaneous metastasis models and in ECs of human cancer. Notably, PIM inhibition increased vascular leakage and metastatic colonization in vivo and impaired the EC barrier via decreased junctional Cadherin-5 and catenins a, b and d. Thus, PIM3 protects the EC barrier in the metastatic niche, which may impair the efficacy of PIM inhibitors in cancer therapies.
Project description:Endothelial cells (ECs) form a tissue-specific barrier for disseminating cancer cells in distant organs. However, the molecular regulation of the ECs in the metastatic niche is poorly understood. Here, we analyzed the transcriptional reprogramming of ECs in the lung metastatic niche six hours after the arrival of melanoma cells in the niche. We discovered a novel EC cluster derived from venous capillaries in response to infiltrating cancer cells, which was enriched for cell-cell communication pathways, including the Dll4, Vegf and Il6-Jak-Stat pathways. The Jak-Stat activated oncogenic Pim3 kinase was a marker of the cancer responding ECs, being upregulated in spontaneous metastasis models and in ECs of human cancer. Notably, PIM inhibition increased vascular leakage and metastatic colonization in vivo and impaired the EC barrier via decreased junctional Cadherin-5 and catenins a, b and d. Thus, PIM3 protects the EC barrier in the metastatic niche, which may impair the efficacy of PIM inhibitors in cancer therapies.
Project description:Endothelial cells (ECs) form a tissue-specific barrier for disseminating cancer cells in distant organs. However, the molecular regulation of the ECs in the metastatic niche is poorly understood. Here, we analyzed the transcriptional reprogramming of ECs in the lung metastatic niche six hours after the arrival of melanoma cells in the niche. We discovered a novel EC cluster derived from venous capillaries in response to infiltrating cancer cells, which was enriched for cell-cell communication pathways, including the Dll4, Vegf and Il6-Jak-Stat pathways. The Jak-Stat activated oncogenic Pim3 kinase was a marker of the cancer responding ECs, being upregulated in spontaneous metastasis models and in ECs of human cancer. Notably, PIM inhibition increased vascular leakage and metastatic colonization in vivo and impaired the EC barrier via decreased junctional Cadherin-5 and catenins a, b and d. Thus, PIM3 protects the EC barrier in the metastatic niche, which may impair the efficacy of PIM inhibitors in cancer therapies.