Anti-Myeloma Effects of the Janus Kinase 2 (JAK2) Inhibitor SAR503 Alone and in Combination Treatment

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4986-4986
Author(s):  
Haiming Chen ◽  
Mingjie Li ◽  
Jennifer Li ◽  
Kevin Delijani ◽  
Danielle Rauch ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Cell ◽  
Cell Viability ◽  
Tumor Cells ◽  
Cell Lines ◽  
Drug Exposure ◽  
Single Agent ◽  
Janus Kinase ◽  
Gm Csf ◽  
Jak2 Inhibitor

Abstract Abstract 4986 Background: Janus kinase 2 (JAK2) is a cytoplasmic tyrosine kinase that carries out a series of cascading signals via signal transducer and activator of transcription (STAT)s, mitogen-activated protein kinase (MAPK), and phosphorylation of PI3K. Activation of the JAK2 pathway plays an important role in both normal and malignant hematopoiesis. The JAK pathway ha been shown to play a key role in multiple myeloma (MM). JAK2 has been specifically implicated in signaling by members of the type II cytokine receptor family (interferon [IFN] receptor), GM-CSF receptor (IL-3R, IL-5R, and GM-CSF-R), gp130 receptor family interleukin-6 (IL-6R) and single chain receptors (Epo-R, Tpo-R, GH-R, and PRL-R). IFN-α inhibits MM cell proliferation in association with cell cycle arrest at G1 and limits the clonogenic growth of both MM cell lines and primary MM patient specimens. SAR503 (Sanofi-Aventis) is a potent, highly selective JAK2 inhibitor. Thus, we evaluated the anti-MM effects of SAR503 as a single agent and in combination with other anti-MM drugs and evaluated gene and protein expression in MM cells exposed to these drugs. Experiment design: The MM cell lines RPMI8226, U266, and MM1s were cultured in RPMI1640 with standard nutrition supplements. Bone marrow aspirates were obtained from MM patients following informed consent. Bone marrow mononuclear cells (BMMCs) were isolated by using density-gradient centrifugation with Histopaque-1077 (Sigma, St Louis). Cells were plated in 96 well plates at a concentration of 6 × 104 cells/100 ml/well, and incubated for 24 hours prior to drug treatment, after which time the drugs were added in replicates of six for 48 hours. BMMCs were incubated in the presence of media, SAR503, doxorubicin, melphalan, dexamethasone, bortezomib, or IFN-α alone or the combination of SAR503 with one of these anti-MM agents. Following the 48-hour drug incubation, cell viability was assessed utilizing the cell proliferation MTS assay. For gene expression studies, total RNA was isolated MM tumor cells with or without drug exposure. RNA was reverse-transcribed into cDNA and amplified using the Thermo-Script RT-PCR System and PCR performed again using the GeneAmp PCR System 9700. Protein phosphorylation of MM tumor cells with or without drug exposure was determined with Western blot analysis. Results: SAR503 alone inhibited MM tumor cell proliferation in a concentration-dependent fashion. The 50% growth inhibition (IC50) of cells from MM cell lines at 48 hours varied (IC50: RPMI8226 1mM; U266 0. 5mM; MM1s 10mM). IC50 of primary MM tumor cells treated with SAR503 ranged from approximately 5 to 10mM in different patients. Notably, the combination of SAR503 and either doxorubicin or melphalan showed markedly reduced cell viability compared to either drug alone in all three MM cell lines and primary tumor cells from MM patients. Since this effect may have resulted from decreased cell proliferation due to inhibition of the JAK2 pathway and cell cycle arrest or increased cell death, we further determined cell apoptosis of MM tumor cells treated with SAR503 alone by using flow cytometric analysis to detect Annexin V and propidium iodide (PI) staining. Our data showed SAR503 increased MM tumor cell apoptosis in a concentration-dependent fashion. The combination of SAR503 and dexamethasone or bortezomib only slightly reduced tumor cell viability in both MM cell lines and primary MM tumor cells more than single agent treatment, and the combination of SAR503 with IFN-α did not enhance the anti-MM effects compared to single drug treatment. Notably, RT-PCR results showed marked decreases in both AKT1 and mTOR gene expression in MM tumor cells treated with SAR503. Conclusion: The combination of the JAK2 inhibitor SAR503 with doxorubicin or melphalan markedly reduces MM tumor cell viability more than single agent treatment. The results from these studies suggest that enhanced anti-MM activity may be observed when SAR503 is combined with conventional treatment for MM. We are currently evaluating the anti-MM effects of SAR503 in these combination treatments in vivo using our MM xenograft models. Disclosures: Berenson: Onyx: Consultancy, Honoraria, Speakers Bureau.

Defibrotide (DF) Targets Tumor-Microenvironmental Interactions and Sensitizes Multiple Myeloma and Solid Tumor Cells to Cytotoxic Chemotherapeutics.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 286-286 ◽  
Author(s):  
Constantine S. Mitsiades ◽  
Cecile Rouleau ◽  
Krishna Menon ◽  
Beverly Teicher ◽  
Massimo Iacobelli ◽  
...  
Keyword(s):  
Stem Cell ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Solid Tumor ◽  
Single Agent ◽  
Conventional Chemotherapy ◽  
Adhesive Properties

Abstract Introduction: Defibrotide (DF) is a polydisperse oligonucleotide with anti-thrombotic, thrombolytic, anti-ischemic, and anti-adhesive properties, which selectively targets the microvasculature and has minimal hemorrhagic risk. DF is an effective treatment for veno-occlusive disease (VOD), an important regimen-related toxicity in stem cell transplantation characterized by endothelial cell injury. DF also augments stem cell mobilization by modulating adhesion in vivo. Because of its cytoprotective effect on the endothelium, we specifically investigated whether DF protects tumor cells from cytotoxic anti-tumor agents. Further, because of its broad anti-adhesive properties, we evaluated whether DF modulates the interaction of MM cells with bone marrow stromal cells (BMSCs), which confers growth, survival and drug resistance in the BM milieu. Methods: In vitro studies in isogenic dexamethasone (Dex)-sensitive and resistant MM cell lines (MM-1S and MM1R, respectively) showed that DF does not attenuate the sensitivity of MM cells to Dex, the proteasome inhibitor bortezomib (PS-341), melphalan (MEL), vinca alkaloids (vincristine, vinblastine), taxanes (paclitaxel) or platinum (cisplatin), but does decrease their sensitivity to doxorubicin. These selective effects in vitro of DF in protecting tumor cells against doxorubicin and modestly sensitizing MM cells to platinum was also confirmed in solid tumor breast (MCF-7) and colon (HT-29) carcinoma cell lines. Although DF had minimal in vitro inhibitory effect on MM or solid tumor cell growth in vitro, it showed in vivo activity as a single agent and enhanced the responsiveness of MM tumors to cytotoxic chemotherapeutics, such as MEL or cyclophosphamide, in human MM xenografts in SCID/NOD mice. The in vivo single-agent activity and chemosensitizing properties of DF, coupled with its lack of major in vitro activity, suggested that DF may not directly target tumor cells, but rather modulate tumor cell interaction with BMSCs. In an ex vivo model of co-culture of primary MM tumor cells with BMSCs (which protects MM cells against conventional chemotherapy), DF alone had a only modest effect on tumor cell viability, but it significantly enhanced MM cell sensitivity to cytotoxic chemotherapy (e.g. MEL), suggesting that a major component of the biological effects of DF may be attributable not to direct targeting of tumor cells, but to modulation of the interactions that tumor cells develop with the local stromal milieu. Conclusion: Our studies show that DF mediates in vivo anti-MM activity by abrogating interactions of MM cells with their BM milieu, thereby enhancing sensitivity and overcoming resistance to conventional chemotherapy. These data support future clinical trials of DF, in combination with both conventional and novel therapies, to improve patient outcome in MM.

Anti-Myeloma Activity by the Combination of the JAK2 Inhibitor Ruxolitinib with Lenalidomide and Corticosteroids

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2114-2114 ◽  
Author(s):  
Haiming Chen ◽  
Eric Sanchez ◽  
Mingjie Li ◽  
Cathy Wang ◽  
Abby Gillespie ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cell Viability ◽  
Tumor Cells ◽  
Cell Lines ◽  
Scid Mice ◽  
M Protein ◽  
Cytotoxic Effects ◽  
Jak2 Inhibitor

Abstract Introduction: The JAK2 inhibitor ruxolitinib (RUX) is an inhibitor of the Janus kinase family of protein tyrosine kinases (JAKs) that is effective for the treatment of myeloproliferative diseases. Immunomodulatory drugs (IMiDs) including lenalidomide (LEN) and corticosteroids have shown efficacy for the treatment of multiple myeloma (MM). The JAK-STAT signaling pathway plays key roles in the growth and survival of malignant plasma cells in MM. In this study, we evaluated the preclinical anti-MM effects of RUX in combination with LEN and corticosteroids, both in vitro and in vivo, and in a patient with MM and polycythemia rubra vera (PRV). Methods: The human MM cell lines U266, RPMI8226 and MM1S cells were derived from ATCC. Primary MM tumor cells were isolated from MM patients’ bone marrow aspirates. The cells were seeded at105 cells/100ul/well in 96-well plates and incubated for 24 h in the presence of vehicle, RUX, LEN or dexamethasone (DEX) alone, RUX + LEN, RUX + DEX, or all three drugs together for 48 h. Cell viability was quantified using the MTS cell proliferation assay. In vitro, synergy between ruxolitinib and lenalidomide or dexamethasone was assessed using the median effect method of Chou and Talalay. For the in vivo studies, the human myeloma tumors (LAGκ-1A or LAGκ-2) were surgically implanted into the left superficial gluteal muscle of anaesthetized naive SCID mice. Mice were blindly assigned to one of the experimental groups, and treatment was initiated 7–21 d after tumor implantation. LEN was administered via oral gavage daily (30 mg/kg). RUX (3 mg/kg) was given via intraperitoneal (IP) injection twice daily. Dexamethasone was administered daily (1.5mg/kg) via IP injection. An 88 year old MM patient with PRV who developed MM on RUX alone and then progressed on LEN+DEX was treated with the combination of all three drugs. Results: In vitro, RUX induced concentration-dependent inhibition of viability in all three MM cell lines (U266, RPMI8226 and MM1S) at RUX 50 mM and inhibition of primary MM tumor cells at a higher concentration (100 mM). In contrast, RUX had negligible cytotoxic effects on normal peripheral blood mononuclear cells (PBMCs). We next examined cell viability in the presence of RUX plus LEN or DEX. First, U266 cells were incubated with a fixed concentration of LEN (30 mM) or DEX (40 mM) with increasing concentrations of RUX (0.1–100 mM) for 48 h. At RUX 50 mM, the cytotoxic effects of LEN were enhanced and at RUX 1 mM, the anti-myeloma effect of DEX was increased. Moreover, the cytotoxic effects of RUX, LEN and DEX were greater than RUX in combination with either LEN or DEX in U266 cells. Similar results were obtained using the RPMI8226 and MM1S cell lines as well as primary MM tumor cells. Next, we evaluated RUX in combination with lenalidomide and dexamethasone in vivo using SCID mice bearing either the human LAGκ-1A or LAGκ-2 MM xenografts. RUX (3mg/kg), LEN (15mg/kg) or DEX (1mg/kg) alone did not inhibit tumor growth in either mice bearing LAGκ-1A or LAGκ-2. In contrast, the combination of RUX with DEX but not LEN slightly decreased tumor volume. However, the combination of all three drugs at the same doses showed a marked reduction of tumor size and delay of tumor growth in both human MM xenograft models. In addition, a patient with MM and PRV experienced sustained and ongoing reductions in his serum M-protein, IgG, and 24-urine M-protein with achievement of a partial response on low doses of RUX (2.5 mg twice daily), LEN (2.5 mg daily), and methylprednisolone (20 mg daily) that has been ongoing for more than 12 months after developing MM on RUX alone and then progressing on the combination of LEN and methylprednisolone. Conclusion: This study illustrates that the combination of the JAK2 inhibitor RUX, LEN and corticosteroids shows both preclinical and promising clinical results for the treatment of MM. Disclosures No relevant conflicts of interest to declare.

scholarly journals B7-H6, an immunoligand for the natural killer cell activating receptor NKp30, reveals inhibitory effects on cell proliferation and migration, but not apoptosis, in cervical cancer derived-cell lines

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Nehla Banu ◽  
Annie Riera-Leal ◽  
Jesse Haramati ◽  
Pablo Cesar Ortiz-Lazareno ◽  
Sandeep Surendra Panikar ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Flow Cytometry ◽  
Cell Proliferation ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cellular Localization ◽  
Cell Proliferation And Migration ◽  
And Migration ◽  
Proliferation And Migration

Abstract Background Although great progress has been made in treatment regimens, cervical cancer remains as one of the most common cancer in women worldwide. Studies focusing on molecules that regulate carcinogenesis may provide potential therapeutic strategies for cervical cancer. B7-H6, an activating immunoligand expressed by several tumor cells, is known to activate NK cell-mediated cytotoxicity once engaged with its natural receptor NKp30. However, the opposite, that is, the effects in the tumor cell triggered by B7-H6 after interacting with NKp30 has not yet been well explored. Methods In this study, we evaluated the surface expression of B7-H6 by flow cytometry. Later, we stimulated B7-H6 positive cervical cancer derived-cell lines (HeLa and SiHa) with recombinant soluble NKp30 (sNKp30) protein and evaluated biological effects using the impedance RTCA system for cell proliferation, the scratch method for cell migration, and flow cytometry for apoptosis. Cellular localization of B7-H6 was determined using confocal microscopy. Results Notably, we observed that the addition of sNKp30 to the cervical cancer cell lines decreased tumor cell proliferation and migration rate, but had no effect on apoptosis. We also found that B7-H6 is selectively maintained in tumor cell lines, and that efforts to sort and purify B7-H6 negative or positive cells were futile, as negative cells, when cultured, regained the expression of B7-H6 and B7-H6 positive cells, when sorted and cultivated, lost a percentage of B7-H6 expression. Conclusions Our results suggest that B7-H6 has an important, as of yet undescribed, role in the biology of the cervical tumor cells themselves, suggesting that this protein might be a promising target for anti-tumor therapy in the future.

ADAMTS13 Expressed In Glioblastoma and Astrocytoma Cells Can Modulate Endothelial Cell Migration

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2306-2306 ◽  
Author(s):  
Manfai Lee ◽  
Courtney Hoyt ◽  
George M Rodgers
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Brain Tumor ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Tumor Cell Proliferation ◽  
Glioblastoma Cells ◽  
Cell Lysates ◽  
Brain Tumor Cells

Abstract ADAMTS13, the von Willebrand factor (vWF) cleaving protease, regulates platelet aggregation and microthrombi formation by cleaving high-molecular weight vWF multimers. It is expressed primarily in hepatic stellate cells, but is also found in endothelial cells. Recently, ADAMTS13 was reported to be expressed and regulated in astrocytes, microglial, neuroblastoma, and adult human brain endothelial cells. Previous in vitro studies by our group with human umbilical vein endothelial cells (HUVEC) showed that ADAMTS13 can promote angiogenesis via upregulating the secretion of VEGF and phosphorylation of VEGFR2, suggesting that ADAMTS13 may also be involved in physiological processes unrelated to vWF cleavage (Lee, M., et al. Microvasc Res. 2012, 84, 109-115). Herein, we report an additional possible role of ADAMTS13 secreted by brain tumor cells to modulate tumor cell angiogenesis. Using a human ADAMTS13 immunoassay, we detected ADAMTS13 in U-87 and LN-229 glioblastoma cell lysates, SW-1088 astrocytoma cell lysates, as well as in the supernatants of all cell lines (> 2.0 ng/mL). Co-incubation of U-87, LN-229, and SW-1088 tumor cell conditioned media with recombinant vWF indicated that brain tumor-secreted ADAMTS13 is biologically active in cleaving vWF multimers (measured by ELISA). Secretion of VEGF was upregulated in LN-229 and SW-1088 cell lines by ADAMTS13. 939 pg/mL and 674 pg/mL of VEGF were measured in LN-229 and SW-1088 cell lysates, respectively, after incubation with 100 ng/mL ADAMTS13. Incubation of LN-229 glioblastoma cells with 10 – 500 ng/mL rh-ADAMTS13 or 50 ng/mL VEGF165 did not affect tumor cell proliferation. No change in tumor cell proliferation was observed when LN-229 cells were incubated with a polyclonal antibody against ADAMTS13 in serum free media supplemented with 10 ng/mL ADAMTS13 or media supplemented with 5% FBS, suggesting that ADAMTS13 secreted by brain tumor cells may be involved in extracellular signaling of endothelial cells. Brain tumor cell secreted-ADAMTS13 induced HUVEC migration in a Matrigel invasion assay. Using a modified Boyden chamber fitted with a Matrigel-coated polycarbonate membrane, LN-229 glioblastoma cells increased HUVEC migration by 83%. LN-229 cells supplemented with 10 ng/mL ADAMTS13 further increased HUVEC migration by 190%, suggesting that tumor cell-secreted ADAMTS13 may modulate EC migration (Fig. 1). Combined with our previous findings suggesting that recombinant ADAMTS13 modulates EC angiogenesis, brain tumor-secreted ADAMTS13 may also be a regulator for tumor vasculature angiogenesis. Disclosures: No relevant conflicts of interest to declare.

Essential experimental steps and estimates of renal carcinoma initiating cells.

2014 ◽  
Vol 32 (15_suppl) ◽  
pp. 11127-11127
Author(s):  
Craig Gedye ◽  
Danylo Sirskyj ◽  
Nazleen Carol Lobo ◽  
Ella Hyatt ◽  
Andrew Evans ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Viability ◽  
Tumor Cells ◽  
Cell Lines ◽  
Stromal Cells ◽  
Ex Vivo ◽  
Rock Inhibitor ◽  
Cell Renal Cell Carcinoma ◽  
Cell Potential

11127 Background: Rare cancer stem cells (CSC), proposed to be solely responsible for tumor propagation and re-initiation, are functionally identified as tumor-initiating cells (TIC) from ex vivo tumors using xenotransplantation and clonogenic limiting dilution assays (LDA). TIC have not previously been described from ex vivohuman clear cell renal cell carcinoma (ccRCC). Methods: Primary human ccRCC samples (n=120) from patients undergoing nephrectomy were processed and implanted as subcapsular fragments or cell suspension injection LDAs with Matrigel in NOD/SCID/IL2Rγ-/- (NSG) mice, and observed for at least 6 months. In vitro clonogenic LDAs assays were performed from primary cell suspensions and ccRCC cell lines. LDAs were supplemented with human stromal cells and proteins, and the Y-26732 ROCK inhibitor. Multiparametric flow cytometry and immunofluorescence were used to investigate tumor heterogeneity and cell viability. Results: ccRCC TIC appeared rare from injected suspensions, but xenografts engrafted frequently from tiny fragments, and clonogenic frequencies were 103-104greater than TIC frequencies, suggesting that LDAs underestimated ccRCC tumor cell potential. We systematically identified multiple methodological steps that distort quantitation and identification of ccRCC TIC. For example cell viability was highly variable prior to processing, disaggregation itself destroyed up to 99% of tumor cells, standard assays substantially overestimated tumor cell viability in suspensions, and supplementation with human extracellular cells or proteins, or inhibition of anoikis by Y-26732 increased clonogenic and TIC frequencies in cell lines and primary ccRCC suspensions. Annexin-V staining revealed that tumor cells were more apoptotic then normal stromal cells, and that tumor cells positive for CD44 (a putative CSC marker) were more viable than CD44- tumor cells. Conclusions: We describe multiple, unappreciated and largely unavoidable observational errors in essential methods used to study TIC in ccRCC. ccRCC TIC may be more common than appreciated. Re-examination of the CSC hypothesis in other solid tumors is warranted in view of these previously unexplored methodological biases.

scholarly journals MicroRNA-215-5p Inhibits the Proliferation and Migration of Wilm’s Tumor Cells by Targeting CRK

2021 ◽  
Vol 20 ◽  
pp. 153303382110365
Author(s):  
Wang Li ◽  
Li Lingdi ◽  
Dang Xiqiang ◽  
Liu Jiheng ◽  
Tan Xin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Luciferase Reporter ◽  
Tumor Cell Lines ◽  
Wilm's Tumor ◽  
And Migration ◽  
Wilm’S Tumor ◽  
Proliferation And Migration

Objective: Wilm’s tumor is a common renal malignancy in childhood with unsatisfactory prognosis. microRNA-215-5p (miR-215-5p) has been reported as a tumor-suppressive miRNA in different types of human cancers, but rarely in the Wilm’s tumor. In light of this, we tried to investigate the regulatory role and underlying mechanism of miR-215-5p in the Wilm’s tumor. Methods: After sample collection and cell culture, the expression of miR-215-5p and CT10 Regulator of Kinase (CRK) was detected. Then rhabdoid tumor cell lines (formerly classified as Wilms’ tumor cell lines), G401 and WT-CLS1 cells were transfected with pcDNA3.1, pcDNA3.1-CRK, sh-NC, sh-CRK, agomir NC, miR-215-5p agomir, antagomir NC or miR-215-5p antagomir to explore the function of miR-215-5p and CRK in the Wilm’s tumor cell proliferation and migration. Moreover, the relationship between miR-215-5p and CRK was analyzed by dual luciferase reporter gene assay. Results: Lowly-expressed miR-215-5p and highly-expressed CRK were observed in the Wilm’s tumor tissues and cells. Transfection of pcDNA3.1-CRK or miR-215-5p antagomir could promote G401 and WT-CLS1 cell proliferation and enhance migration ability, while transfection of sh-CRK or miR-215-5p agomir led to opposite results. Additionally, miR-215-5p may bind to CRK. Moreover, transfection of pcDNA3.1-CRK in G401 and WT-CLS1 cells could partially reverse the inhibitory effect of miR-215-5p agomir on the proliferation and migration of Wilm’s tumor cells. Conclusion: Our study highlighted that miR-215-5p could suppress the proliferation and migration of Wilm’s tumor cells by regulating the expression of CRK, providing new ideas for molecular targeted therapy for Wilm’s tumor.

scholarly journals Oncogenic K-Ras Activates p38 to Maintain Colorectal Cancer Cell Proliferation during MEK Inhibition

2010 ◽  
Vol 32 (4) ◽  
pp. 245-257
Author(s):  
Winan J. van Houdt ◽  
Menno T. de Bruijn ◽  
Benjamin L. Emmink ◽  
Danielle Raats ◽  
Frederik J. H. Hoogwater ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Rna Interference ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Colorectal Tumor ◽  
Erk Pathway ◽  
Mek Inhibition

Background: Colon carcinomas frequently contain activating mutations in the K-ras proto-oncogene. K-ras itself is a poor drug target and drug development efforts have mostly focused on components of the classical Ras-activated MEK/ERK pathway. Here we have studied whether endogenous oncogenic K-ras affects the dependency of colorectal tumor cells on MEK/ERK signaling.Methods: K-ras mutant colorectal tumor cell lines C26, HCT116 and L169 were used. K-ras or components of the MEK/ERK and p38 pathway were suppressed by RNA interference (RNAi). MEK was inhibited by U0126. p38 was inhibited by SB203850.Results: MEK inhibition, or suppression of MEK1/2 or ERK1/2 by RNA interference, reduced the proliferation rate of all colorectal cancer cell lines. However, cell proliferation returned to normal after two weeks of chronic inhibition, despite the continued suppression of MEK or ERK. In contrast, K-ras-suppressed tumor cells entered an irreversible senescent-like state following ERK pathway inhibition. MEK inhibition or ERK1/2 suppression caused activation of p38α in a K-ras-dependent manner. Inhibition or suppression of p38α prevented the recovery of K-ras mutant tumor cells during prolonged MEK inhibition.Conclusions: Oncogenic K-ras activates p38α to maintain cell proliferation during MEK inhibition. MEK-targeting therapeutics can create an acquired tumor cell dependency on p38α.

scholarly journals Metformin and sodium dichloroacetate effects on proliferation, apoptosis, and metabolic activity tested alone and in combination in a canine prostate and a bladder cancer cell line

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257403
Author(s):  
Katharina Klose ◽  
Eva-Maria Packeiser ◽  
Petra Müller ◽  
José Luis Granados-Soler ◽  
Jan Torben Schille ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Line ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Metabolic Activity ◽  
Single Agent ◽  
Bladder Cancer Cell Line ◽  
Apoptosis Resistance ◽  
Quantitative Hplc

An important approach in tumor therapy is combining substances with different action mechanisms aiming to enhance the antineoplastic effect, decrease the therapeutic dosage, and avoid resistance mechanisms. Moreover, evaluating compounds already approved for the treatment of non-neoplastic diseases is promising for new antineoplastic therapies. Sodium dichloroacetate (DCA) reactivates oxidative phosphorylation in the cancer cell mitochondria, reducing apoptosis resistance in cancer cells. Furthermore, metformin inhibits the proliferation of tumor cells and CD133+ cancer -stem-like cells. In the present study, we evaluated the independent and synergistic effect of metformin and DCA on the metabolic activity, cell proliferation, and apoptosis of a canine prostate adenocarcinoma (Adcarc1258) and a transitional cell carcinoma cell line (TCC1506) in comparison to a primary canine fibroblast culture. Determining metformin uptake in tumor cells was performed by quantitative HPLC. Depending on the dosage, metformin as a single agent inhibited the metabolic activity and cell proliferation of the tumor cells, showing only minor effects on the fibroblasts. Furthermore, 1 mM metformin increased apoptosis over 96 h in the tumor cell lines but not in fibroblasts. Additionally, metformin uptake into the tumor cells in vitro was measurable by quantitative HPLC. Synergistic effects for the combination therapy were observed in both neoplastic cell lines as well as in the fibroblasts. Based on these results, metformin might be a promising therapeutic agent for canine urogenital tumors. Further studies on kinetics, toxicology, bioavailability, and application of metformin in dogs are necessary.

Accessory Cells From Diverse Tissue Microenvironments Alter Tumor Cell Responses to Multitargeted Kinase Inhibitors: Therapeutic Implications From a Large-Scale Systematic Evaluation.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2469-2469
Author(s):  
Ana Acuña-Villaorduña ◽  
Douglas W. McMillin ◽  
Constantine S. Mitsiades
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Research Funding ◽  
Kinase Inhibitors ◽  
Accessory Cell ◽  
Tumor Cell Lines ◽  
Jak2 Inhibitor ◽  
Accessory Cells ◽  
Anti Tumor Activity

Abstract Abstract 2469 Introduction: Kinases are integral components of diverse signaling cascades which can mediate microenvironment-derived resistance of tumor cells to apoptosis. We thus hypothesized that tumor cell-microenvironment interactions alter the anti-tumor activity of multi-targeted kinase inhibitors and could contibute to discordant efficacy results in conventional preclinical models which do not account for these interactions vs. in clinical studies. Methods: We evaluated 6 multi-targeted kinase inhibitors initially developed to target IGF1R (XL-228), Akt/p70S6K (EXEL-6075), B-/C-RAF(EXEL-0094), CHK1/2 (XL844), met/VEGFR2(EXEL-6323) and JAK2 (XL019). Compounds were tested (0–20 μM, 48 hrs) against luciferase-expressing human multiple myeloma (MM) (n=8), mantle cell lymphoma (n=2) and breast cancer (n=1) cell lines. For each of these treatments, tumor cells were cultured in isolation or co-cultured with immortalized human bone marrow stromal cells (BMSCs, n=2); lung fibroblasts; hepatocytes; or brain astrocytes. Tumor cell viability was quantified by tumor cell compartment-specific bioluminescence imaging (CS-BLI). For each compound and tumor cell line, the area under the dose-response curve (AUC) was calculated as % of the AUC that corresponds to 100% tumor cell viability at all doses, to provide cumulative measure of drug activity across the range of tested drug concentrations. Differences in % AUCs in presence vs. absence of accessory cells were compared by 2-tailed paired t-test. The average value and skewness of distribution for log(10)IC50 of enzymatic activity for each kinase and inhibitor tested were calculated for quantitative comparison of multi-targeted nature of these compounds. Results: Co-culture of most tumor cell lines with accessory cells triggered resistance for 5 of 6 compounds tested, as evidenced by statistically significant (p<0.001 for all tests) increases in %AUC with vs. without co-culture with accessory cells (average %AUC differences of 4.7%, 23.4%, 6.2%, 9.7% and 10.8% for IGF1R, Akt/p70S6K, B-/C-RAF, CHK1/2; and met/VEGFR2 inhibitors, respectively, with corresponding 95% C.I. of 2.0–7.5%, 18.2–28.6%, 2.0–10.4%, 5.3–14.1%, and 3.9–17.6%). In contrast, co-culture with accessory cells increased the response of most tumor cell lines to JAK2 inhibitor (average AUC decrease of 13.8%, 95%CI 1.9–16.4, p<0.001). Results were consistent and statistically significant when analysis was restricted to MM cell lines only. For some inhibitors, heterogeneous responses of different tumor cells to accessory cells were noted. For example, for met/VEGFR2 and CHK1/2 inhibitors, 58.0% (40/69) and 60.0% (36/60) of experimental conditions, respectively, showed co-culture-induced resistance, while 31.9% (22/69) and 18.0% (11/60) of cocultures, respectively, showed sensitization to these inhibitors. High frequency of sensitization was observed in co-cultures of a bortezomib/Dex-resistant subline of MM1S cells treated with met/VEGFR2 inhibitor (63.6%, 7/11 of co-cultures tested), and in co-cultures with BMSCs treated with CHK1/2 inhibitor (29.6% of co-cultures tested). The degree of sensitization or resistance by accessory cells (%AUC difference with vs. without co-culture) did not correlate with quantitative measures of multi-targeted nature for each inhibitor. Conclusions: Accessory cells from different tissues significantly modulated tumor cell responses to diverse multi-targeted kinase inhibitors. Co-cultures enhanced the anti-tumor activity of JAK2 inhibitor, but decreased the activity of the other compounds tested. These different responses did not correlate with how multitargeted each inhibitor was. The sensitization to the JAK inhibitor may specifically reflect increased dependency on JAK signaling for tumor cells when they interact with accessory cells. Accessory cell-induced resistance to some kinase inhibitors (e.g. IGF1R, Akt, CHK1–2) may account for observed differences in their preclinical vs. clinical efficacy. These results provide a rationale for preclinical testing of compounds against large panels of tumor cell lines and clinically-relevant accessory cell types to help develop therapeutics against tumors localized in specific tissue microenvironmental niches. Disclosures: McMillin: Axios Biosciences: Equity Ownership. Mitsiades:Millennium Pharmaceuticals: Honoraria; Celgene: Honoraria; Novartis Pharmaceuticals: Honoraria; Bristol-Myers Squibb: Honoraria; Merck &Co.: Honoraria; Centocor: Honoraria; Arno Therapeutics: Honoraria; Amgen: Research Funding; AVEO Pharma: Research Funding; OSI: Research Funding; EMD Serono: Research Funding; Sunesis: Research Funding; Johnson & Johnson: Research Funding; PharmaMar: Licensing royalties Other; Axios Biosciences: Uncompensated Role as advisor, Uncompensated Role as advisor Other.

Selective reduction of JAK2V617F-dependent cell growth by siRNA/shRNA and its reversal by cytokines

Blood ◽  
2009 ◽  
Vol 114 (9) ◽  
pp. 1842-1851 ◽  
Author(s):  
Abire Jedidi ◽  
Caroline Marty ◽  
Charleen Oligo ◽  
Laurence Jeanson-Leh ◽  
Jean-Antoine Ribeil ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Clinical Trials ◽  
Cell Lines ◽  
Small Molecule ◽  
Cell Cycle Progression ◽  
Selective Reduction ◽  
Myeloproliferative Disorders ◽  
Janus Kinase ◽  
Small Interfering Rnas ◽  
Jak2 Inhibitor

The JAKV617F mutation is responsible for the majority of breakpoint cluster region (BCR)/Abelson (ABL)–negative myeloproliferative disorders. Ongoing clinical trials of Janus kinase 2 (JAK2) inhibitors in myeloproliferative disorder patients use small molecules targeting both wild-type and mutated JAK2. To selectively target malignant cells, we developed JAK2V617F-specific small interfering RNAs or short hairpin RNAs. Expression of these RNAs in cell lines or CD34+ cells from patients reduced JAK2V617F-driven autonomous cell proliferation. Mechanisms of inhibition involved selective JAK2V617F protein down-regulation, and consequently, decrease in signal transducer and activator of transcription 5 phosphorylation, cell-cycle progression, and cell survival. However, the addition of high concentrations of cytokines to cell lines or erythropoietin to patient cells greatly reduced growth inhibition. Similarly, the efficacy of a JAK2 small molecule inhibitor on cell line and patient cell proliferation dose dependently decreased with the addition of cytokines. Our results demonstrate that it is possible to specifically target JAK2V617F by RNA interference (RNAi) strategies. In addition, cytokines partially reverse the inhibition induced by both RNAi and small molecule approaches. This strongly suggests that patient cytokine levels in current JAK2 inhibitor clinical trials modulate the outcome of these therapies.

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