Activating mutations in JAK2 and CALR differentially affect intracellular calcium flux in store operated calcium entry.

BACKGROUND: Calcium (Ca2+) signaling regulates various vital cellular functions, including integrin activation and cell migration. Store-operated calcium entry (SOCE) via calcium release-activated calcium (CRAC) channels represents a major pathway for Ca2+ influx from the extracellular space in multiple cell types. The impact of JAK2-V617F and CALR mutations which are disease initiating in myeloproliferative neoplasms (MPN) on SOCE, calcium flux from the endoplasmic reticulum (ER) to the cytosol, and related key signaling pathways in the presence or absence of erythropoietin (EPO) or thrombopoietin (TPO) is poorly understood. Thus, this study aimed to elucidate the effects of these mutations on the aforementioned calcium dynamics, in cellular models of MPN. METHODS: Intracellular Ca2+ levels were measured over a time frame of 0-1080 s in Fura-2 AM labeled myeloid progenitor 32D cells expressing various mutations (JAK2-WT/EpoR, JAK2-V617F/EpoR; CALR-WT/MPL, CALR-ins5/MPL, and del52/MPL). Basal Ca2+ concentrations were assessed from 0-108 s. Subsequently, cells were stimulated with EPO/TPO in Ca2+-free Ringer solution, measuring Ca2+ levels from 109-594 s (store depletion). Then, 2 mM of Ca2+ buffer resembling physiological concentrations was added to induce SOCE, and Ca2+ levels were measured from 595-1080 s. Fura-2 AM emission ratios (F340/380) were used to quantify the integrated Ca2+ signal. Statistical significance was assessed by unpaired Student's t-test or Mann-Whitney-U-test, one-way or two-way ANOVA followed by Tukey's multiple comparison test. RESULTS: Following EPO stimulation, the area under the curve (AUC) representing SOCE significantly increased in 32D-JAK2-V617F cells compared to JAK2-WT cells. In TPO-stimulated CALR cells, we observed elevated Ca2+ levels during store depletion and SOCE in CALR-WT cells compared to CALR-ins5 and del52 cells. Notably, upon stimulation, key components of the Ca2+ signaling pathways, including PLCγ-1 and IP3R, were differentially affected in these cell lines. Hyper-activated PLCγ-1 and IP3R were observed in JAK2-V617F but not in CALR mutated cells. Inhibition of calcium regulatory mechanisms suppressed cellular growth and induced apoptosis in JAK2-V617F cells. CONCLUSIONS: This report highlights the impact of JAK2 and CALR mutations on Ca2+ flux (store depletion and SOCE) in response to stimulation with EPO and TPO. The study shows that the JAK2-V617F mutation strongly alters the regulatory mechanism of EpoR/JAK2-dependent intracellular calcium balance, affecting baseline calcium levels, EPO-induced calcium entry, and PLCγ-1 signaling pathways. Our results reveal an important role of calcium flux in the homeostasis of JAK2-V617F positive cells.

Novel Adiponectin Receptor Agonist Inhibits Cholangiocarcinoma via Adenosine Monophosphate-activated Protein Kinase.

BACKGROUND: Cholangiocarcinoma (CCA) has a poor prognosis and only limited palliative treatment options. The deficiency of adiponectin and adenosine monophosphate-activated protein kinase (AMPK) signaling was reported in several malignancies, but the alteration of these proteins in CCA is still unclear. OBJECTIVES: This study aimed to assess the role of adiponectin and AMPK signaling in CCA. Furthermore, AdipoRon, a novel adiponectin receptor (AdipoR) agonist, was evaluated in vitro and in vivo as a new anti-tumor therapy for CCA. METHODS: The expression of AdipoR1 and p-AMPKα in human tissue microarrays (TMAs) was evaluated by immunohistochemistry staining (IHC). The effect of 2-(4-Benzoylphenoxy)-N-[1-(phenylmethyl)- 4-piperidinyl]-acetamide (AdipoRon) was investigated in vitro with proliferation, crystal violet, migration, invasion, colony formation, senescence, cell cycle and apoptosis assays and in vivo using a CCA engineered mouse model (AlbCre/LSL-KRASG12D/p53L/L). RT-qPCR and western blot methods were applied to study molecular alterations in murine tissues. RESULTS: AdipoR1 and p-AMPKα were impaired in human CCA tissues, compared to adjacent non-tumor tissue. There was a positive correlation between the AdipoR1 and p-AMPKα levels in CCA tissues. Treatment with AdipoRon inhibited proliferation, migration, invasion and colony formation and induced apoptosis in a time- and dose-dependent manner in vitro(p<0.05). In addition, AdipoRon reduced the number of CCA and tumor volume, prolonged survival, and decreased metastasis and ascites in the treated group compared to the control group (p<0.05). CONCLUSIONS: AdipoR1 and p-AMPKα are impaired in CCA tissues, and AdipoRon effectively inhibits CCA in vitro and in vivo. Thus, AdipoRon may be considered as a potential anti-tumor therapy in CCA.

Amifostine analog, DRDE-30, alleviates radiation induced lung damage by attenuating inflammation and fibrosis.

BACKGROUND: Radiotherapy of thoracic neoplasms and accidental radiation exposure often results in pneumonitis and fibrosis of lungs. Here, we investigated the potential of amifostine analogs: DRDE-07, DRDE-30, and DRDE-35, in alleviating radiation-induced lung damage. METHODS: C57BL/6 mice were exposed to 13.5 Gy thoracic irradiation, 30 min after intraperitoneal administration of the analogs, and assessed for modulation of the pathological response at 12 and 24 weeks. KEY FINDINGS: DRDE-07, DRDE-30 and DRDE-35 increased the survival of irradiated mice from 20% to 30%, 80% and 70% respectively. Reduced parenchymal opacity (X-ray CT) in the lungs of DRDE-30 pre-treated mice corroborated well with the significant decrease in Ashcroft score (p < 0.01). Two-fold increase in SOD and catalase activities (p < 0.05), coupled with a 50% increase in GSH content and a 60% decrease in MDA content (p < 0.05) suggested restoration of the antioxidant defence system. A 20% to 40% decrease in radiation-induced apoptotic and mitotic death in the lung tissue (micronuclei: p < 0.01), resulted in attenuated lung and vascular permeability (FITC-Dextran leakage) by 50% (p < 0.01), and a commensurate reduction (~50%) in leukocyte infiltration in the injured tissue (p < 0.05). DRDE-30 abrogated the activation of pro-inflammatory NF-κB and p38/MAPK signaling cascades, suppressing the release of pro-inflammatory cytokines (IL-1ß: p < 0.05; TNF-α: p < 0.05; IL-6: p < 0.05) and up-regulation of CAMs on the endothelial cell surface. Reduction in hydroxyproline content (p < 0.01) and collagen suggested inhibition of lung fibrosis which was associated with attenuation of TGF-ß/Smad pathway-mediated-EMT. CONCLUSION: DRDE-30 could be a potential prophylactic agent against radiation-induced lung injury.

Thromboinflammation in Myeloproliferative Neoplasms (MPN)-A Puzzle Still to Be Solved.

Myeloproliferative neoplasms (MPNs), a group of malignant hematological disorders, occur as a consequence of somatic mutations in the hematopoietic stem cell compartment and show excessive accumulation of mature myeloid cells in the blood. A major cause of morbidity and mortality in these patients is the marked prothrombotic state leading to venous and arterial thrombosis, including myocardial infarction (MI), deep vein thrombosis (DVT), and strokes. Additionally, many MPN patients suffer from inflammation-mediated constitutional symptoms, such as fever, night sweats, fatigue, and cachexia. The chronic inflammatory syndrome in MPNs is associated with the up-regulation of various inflammatory cytokines in patients and is involved in the formation of the so-called MPN thromboinflammation. JAK2-V617F, the most prevalent mutation in MPNs, has been shown to activate a number of integrins on mature myeloid cells, including granulocytes and erythrocytes, which increase adhesion and drive venous thrombosis in murine knock-in/out models. This review aims to shed light on the current understanding of thromboinflammation, involvement of neutrophils in the prothrombotic state, plausible molecular mechanisms triggering the process of thrombosis, and potential novel therapeutic targets for developing effective strategies to reduce the MPN disease burden.

Targeting interleukin 6 signaling by monoclonal antibody siltuximab on cholangiocarcinoma.

BACKGROUND AND AIM: Cholangiocarcinoma has an unimproved prognosis. Interleukin 6 (IL-6) has an oncogenic potential in some cancer diseases. However, the role of IL-6 in cholangiocarcinoma carcinogenesis is not well understood. The current study investigated the role of IL-6 signaling in cholangiocarcinoma carcinogenesis and efficacy of siltuximab treatment on cholangiocarcinoma in vitro and in vivo. METHODS: The expression of IL-6 was analyzed on human cholangiocarcinoma cell lines and murine and human cholangiocarcinoma tissues, using reverse transcription real-time polymerase chain reaction and immunohistochemistry. In addition, the effect of anti-IL-6 chimeric monoclonal antibody, siltuximab, was investigated in vitro by proliferation, migration, and two-dimensional and three-dimensional invasion assays and in vivo by xenograft mouse model. Western blot was applied to study the molecular alteration. RESULTS: Our result shows high expression of IL-6 in human cholangiocarcinoma cells, and IL-6 stimulants enhance cholangiocarcinoma cell proliferation. In addition, murine and human cholangiocarcinoma tissues express significantly higher levels of IL-6, compared with adjacent non-tumor tissues. On the cholangiocarcinoma engineered mouse model, IL-6 level is associated with tumor volume. Taken together, our data indicate an oncogenic potential of IL-6 in cholangiocarcinoma carcinogenesis. Siltuximab sufficiently abrogates IL-6 signaling and inhibits cholangiocarcinoma progression in vitro and in vivo. The results additionally indicate a relative alteration of IL-6 signaling and its molecular targets, such as STAT3, Wnt/ß-catenin, and mesenchymal markers. CONCLUSIONS: Interleukin 6 plays an essential role in cholangiocarcinoma carcinogenesis, and siltuximab has the potential to be considered as a new treatment option for cholangiocarcinoma patients.

Haprolid Inhibits Tumor Growth of Hepatocellular Carcinoma through Rb/E2F and Akt/mTOR Inhibition.

BACKGROUND: Hepatocellular carcinoma (HCC) represents a major health burden with limited curative treatment options. There is a substantial unmet need to develop innovative approaches to impact the progression of advanced HCC. Haprolid is a novel natural component isolated from myxobacteria. Haprolid has been reported as a potent selective cytotoxin against a panel of tumor cells in recent studies including HCC cells. The aims of this study are to evaluate the antitumor effect of haprolid in HCC and to understand its underlying molecular mechanisms. METHODS: The efficacy of haprolid was evaluated in human HCC cell lines (Huh-7, Hep3B and HepG2) and xenograft tumors (NMRI-Foxn1nu mice with injection of Hep3B cells). Cytotoxic activity of haprolid was determined by the WST-1 and crystal violet assay. Wound healing, transwell and tumorsphere assays were performed to investigate migration and invasion of HCC cells. Apoptosis and cell-cycle distribution were measured by flow cytometry. The effects of haprolid on the Rb/E2F and Akt/mTOR pathway were examined by immunoblotting and immunohistochemistry. RESULTS: haprolid treatment significantly inhibited cell proliferation, migration and invasion in vitro. The epithelial-mesenchymal transition (EMT) was impaired by haprolid treatment and the expression level of N-cadherin, vimentin and Snail was downregulated. Moreover, growth of HCC cells in vitro was suppressed by inhibition of G1/S transition, and partially by induction of apoptosis. The drug induced downregulation of cell cycle regulatory proteins cyclin A, cyclin B and CDK2 and induced upregulation of p21 and p27. Further evidence showed that these effects of haprolid were associated with Rb/E2F downregulation and Akt/mTOR inhibition. Finally, in vivo nude mice experiments demonstrated significant inhibition of tumor growth upon haprolid treatment. CONCLUSION: Our results show that haprolid inhibits the growth of HCC through dual inhibition of Rb/E2F and Akt/mTOR pathways. Therefore, haprolid might be considered as a new and promising candidate for the palliative therapy of HCC.

Hypoxia induced Sonic Hedgehog signaling regulates cancer stemness, epithelial-to-mesenchymal transition and invasion in cholangiocarcinoma.

Aberrant activation of Sonic Hedgehog (SHH) pathway has been implicated in a variety of cancers including cholangiocarcinoma (CC); however, the influencing factors are still unknown. Additionally, intratumoral hypoxia is known to contribute towards therapeutic resistance through modulatory effects on various pathways. In this study, we investigated the relationship between hypoxia and SHH pathway activation and the effect of this interplay on cancer stemness and epithelial-to- mesenchymal transition (EMT) during cholangiocarcinogenesis. Hypoxia promoted SHH pathway activation, evidenced by upregulated SHH and SMO levels, and enhanced glioma-associated oncogene homolog 1 (GLI1) nuclear translocation; whereas silencing of HIF-1α impaired SHH upregulation. Hypoxia also enhanced the expression of cancer stem cell (CSC) transcription factors (NANOG, Oct4, SOX2), CD133 and EMT markers (N-cadherin, Vimentin), thereby supporting invasion. Cyclopamine treatment suppressed hypoxia induced SHH pathway activation, consequently reducing invasiveness by downregulating the expression of CSC transcription factors, CD133 and EMT. Cyclopamine induced apoptosis in CC cells under hypoxia, suggesting that hypoxia induced activation of SHH pathway has modulatory effects on CC progression. Therefore, SHH signaling is proposed as a target for CC treatment, which is refractory to standard chemotherapy.

Amifostine Analog, DRDE-30, Attenuates Bleomycin-Induced Pulmonary Fibrosis in Mice.

Bleomycin (BLM) is an effective curative option in the management of several malignancies including pleural effusions; but pulmonary toxicity, comprising of pneumonitis and fibrosis, poses challenge in its use as a front-line chemotherapeutic. Although Amifostine has been found to protect lungs from the toxic effects of radiation and BLM, its application is limited due to associated toxicity and unfavorable route of administration. Therefore, there is a need for selective, potent, and safe anti-fibrotic drugs. The current study was undertaken to assess the protective effects of DRDE-30, an analog of Amifostine, on BLM-induced lung injury in C57BL/6 mice. Whole body micro- computed tomography (CT) was used to non-invasively observe tissue damage, while broncheo-alveolar lavage fluid (BALF) and lung tissues were assessed for oxidative damage, inflammation and fibrosis. Changes in the lung density revealed by micro-CT suggested protection against BLM-induced lung injury by DRDE-30, which correlated well with changes in lung morphology and histopathology. DRDE-30 significantly blunted BLM-induced oxidative stress, inflammation and fibrosis in the lungs evidenced by reduced oxidative damage, endothelial barrier dysfunction, Myeloperoxidase (MPO) activity, pro-inflammatory cytokine release and protection of tissue architecture, that could be linked to enhanced anti-oxidant defense system and suppression of redox-sensitive pro-inflammatory signaling cascades. DRDE-30 decreased the BLM-induced augmentation in BALF TGF-ß and lung hydroxyproline levels, as well as reduced the expression of the mesenchymal marker α-smooth muscle actin (α-SMA), suggesting the suppression of epithelial to mesenchymal transition (EMT) as one of its anti-fibrotic effects. The results demonstrate that the Amifostine analog, DRDE-30, ameliorates the oxidative injury and lung fibrosis induced by BLM and strengthen its potential use as an adjuvant in alleviating the side effects of BLM.

Silencing of Kangai 1 C-terminal interacting tetraspanin suppresses progression of cholangiocarcinoma.

Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy. CC treatment options are very limited especially for patients with distant metastasis. Kangai 1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in numerous cancers, but the role of KITENIN in CC remains unknown. Here, we have investigated for the first time the function of KITENIN in human CC cell lines (TFK-1, SZ-1), tissues and a CC mouse model (Alb-Cre/LSL-KRASG12D/p53L/L). KITENIN was expressed in 92.2% of human CC tissues, in murine CC samples and also in human CC cell lines. Knockdown of KITENIN by small interfering RNA (siRNA) effectively reduced proliferation, migration, invasion and colony formation in both intra- and extra-hepatic CC cells. The expression of epithelial-mesenchymal transition (EMT) markers like N-cadherin, Vimentin, Snail and Slug were suppressed in KITENIN knockdown CC cells. Our results indicate that KITENIN is crucial for cholangiocarcinogenesis and it might become a potential therapeutic target for human CC treatment.

Chronic Dietary Administration of the Glycolytic Inhibitor 2-Deoxy-D-Glucose (2-DG) Inhibits the Growth of Implanted Ehrlich's Ascites Tumor in Mice.

BACKGROUND: Dietary energy restriction (DER) has been well established as a potent anticancer strategy. Non-adoption of restricted diet for an extended period has limited its practical implementation in humans with a compelling need to develop agents that mimic effects similar to DER, without reduction in actual dietary intake. Glycolytic inhibitor, 2-deoxy-D-glucose (2-DG), has recently been shown to possess potential as an energy restriction mimetic agent (ERMA). In the present study we evaluated the effect of dietary 2-DG administration on a mouse tumor model, with a focus on several potential mechanisms that may account for the inhibition of tumorigenesis. METHODOLOGY/PRINCIPAL FINDINGS: Swiss albino strain 'A' mice were administered with 0.2% and 0.4% w/v 2-DG in drinking water for 3 months prior to tumor implantation (Ehrlich's ascites carcinoma; EAC) and continued till the termination of the study with no adverse effects on general physiology and animal growth. Dietary 2-DG significantly reduced the tumor incidence, delayed the onset, and compromised the tumor growth along with enhanced survival. We observed reduced blood glucose and serum insulin levels along with decreased proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine positive (BrdU+) tumor cells in 2-DG fed mice. Also, reduced levels of certain key players of metabolic pathways such as phosphatidylinositol 3-kinase (PI3K), phosphorylated-Akt and hypoxia inducible factor-1 alpha (HIF-1α) were also noted in tumors of 2-DG fed mice. Further, decrease in CD4+/CD8+ ratio and T-regulatory cells observed in 2-DG fed mice suggested enhanced antitumor immunity and T cell effector function. CONCLUSION/SIGNIFICANCE: These results strongly suggest that dietary 2-DG administration in mice, at doses easily achievable in humans, suitably modulates several pleotrophic factors mimicking DER and inhibits tumorigenesis, emphasizing the use of ERMAs as a promising cancer preventive strategy.

Nuclear anomalies, chromosomal aberrations and proliferation rates in cultured lymphocytes of head and neck cancer patients.

Head and neck cancers (HNC) are extremely complex disease types and it is likely that chromosomal instability is involved in the genetic mechanisms of its genesis. However, there is little information regarding the background levels of chromosome instability in these patients. In this pilot study, we examined spontaneous chromosome instability in short-term lymphocyte cultures (72 hours) from 72 study subjects - 36 newly diagnosed HNC squamous cell carcinoma patients and 36 healthy ethnic controls. We estimated chromosome instability (CIN) using chromosomal aberration (CA) analysis and nuclear level anomalies using the Cytokinesis Block Micronucleus Cytome Assay (CBMN Cyt Assay). The proliferation rates in cultures of peripheral blood lymphocytes (PBL) were assessed by calculating the Cytokinesis Block Proliferation Index (CBPI). Our results showed a significantly higher mean level of spontaneous chromosome type aberrations (CSAs), chromatid type aberration (CTAs) dicentric chromosomes (DIC) and chromosome aneuploidy (CANEUP) in patients (CSAs, 0.0294±0.0038; CTAs, 0.0925±0.0060; DICs, 0.0213±0.0028; and CANEUPs, 0.0308±0.0035) compared to controls (CSAs, 0.0005±0.0003; CTAs, 0.0058±0.0015; DICs, 0.0005±0.0003; and CANEUPs, 0.0052±0.0013) where p<0.001. Similarly, spontaneous nuclear anomalies showed significantly higher mean level of micronuclei (MNi), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) among cases (MNi, 0.01867±0.00108; NPBs, 0.01561±0.00234; NBUDs, 0.00658±0.00068) compared with controls (MNi, 0.00027±0.00009; NPBs, 0.00002±0.00002; NBUDs, 0.00011±0.00007).The evaluation of CBPI supported genomic instability in the peripheral blood lymphocytes showing a significantly lower proliferation rate in HNC patients (1.525±0.005552) compared to healthy subjects (1.686±0.009520 ) (p<0.0001). In conclusion, our preliminary results showed that visible spontaneous genomic instability and low rate proliferation in the cultured peripheral lymphocytes of solid tumors could be biomarkers to predict malignancy in early stages.