Apoptosis induction mediated through PI3-kinase/AKT/mTOR pathway using anti-ROR1 monoclonal antibody in chronic lymphocytic leukemia cells.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 7087-7087
Author(s):  
Amir Hossein Daneshmanesh ◽  
Mohammad Hojat Farsangi ◽  
Ali Moshfegh ◽  
Salam Khan ◽  
Anders Österborg ◽  
...  

7087 Background: The PI3K/AKT/mTOR is a central pathway activated in many types of cancer. Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase regulating cell growth, proliferation and survival. In CLL cells PI3K pathway is constitutively activated leading to AKT activation with subsequent phosphorylation of other downstream signaling molecules. ROR1 is a type I transmembrane RTK, overexpressed and constitutively phosphorylated in CLL. A unique anti-ROR1 mAb directed against CRD region of ROR1 was capable of inducing direct apoptosis as well as dephosphorylating the ROR1 molecule. Here, we investigated the apoptotic effect of the anti-ROR1 mAb and effects on the PI3K/AKT/mTOR pathway using primary CLL cells. Methods: Apoptosis was detected by the MTT assay and Annexin V/PI methods in a 24 h assay. Antibody untreated and treated cell lysates were prepared and subjected to Western blot analysis for identification of the signaling molecules involved in apoptosis induced by the ROR1 mAb. We analysed total and phosphorylated levels of the following signaling proteins: AKT, p-AKT, PI3K, p-PI3K, mTOR, p-mTOR, ERK, p-ERK, PKC and p-PKC. Phosphoproteins were measured before incubation with the mAb and after 20 min-24 h. Results: ROR1 detection on surface of the CLL cells was 80-85% and apoptotic frequency 45-50%. Western blot analysis showed decreased levels of p-AKT, p85 isoform of p-PI3K and p-mTOR in treated compared to untreated samples. No changes in the phosphorylation levels of ERK and PKC proteins were seen. Conclusions: Incubation of CLL cells with the anti-ROR1 mAb induced apoptosis of CLL cells. Apoptosis was preceded by dephosphorylation of PI3K, AKT and mTOR proteins indicating deactivation of these proteins by the ROR1 mAb. In untreated CLL cells no effect was noted. Furthermore no dephosphorylation of PKC or ERK was seen. We suggest that activation of mTOR might occur via the PI3K/AKT pathway and may be a survival signal in CLL cells associated with the aberrant expression of ROR1. Further studies are warranted to understand better the signaling pathways associated with ROR1 and the downstream signaling effects of ROR1 targeting drugs.

2021 ◽  
Author(s):  
Yanyan Han ◽  
Jinfeng Yang ◽  
Yan Sun ◽  
Shujun Fan ◽  
Ying Lu ◽  
...  

Abstract Background: Breast cancer is an aggressive malignancy that is unresponsive to conventional therapies. Parthenolide has been demonstrated to have anticancer effects against various types of cancer, including breast cancer. The aim of the present study was to investigate the effect and underlying mechanism of parthenolide in human breast cancer. Methods: Autophagy was measured through immunofluorescence and western blotting. DAPI staining and flow cytometry analysis were used to measure apoptosis. Western blot analysis was used to investigate the mechanism of autophagy induced by parthenolide on the expression levels of phosphoinositide 3‑kinase (PI3K), AKT, phosphorylated (p‑) AKT, mammalian target of rapamycin (mTOR), ATG13 and ATG14. Furthermore, apoptosis was confirmed via western blot analysis. Conclusion: Parthenolide inhibits breast cancer cell proliferation and induces autophagy and apoptosis, and suggested that the PI3K/AKT/mTOR pathway serves an important role in autophagy and apoptosis.


Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 323 ◽  
Author(s):  
Hyun Jung ◽  
Dae-Sung Lee ◽  
Seong Park ◽  
Jung Choi ◽  
Won-Kyo Jung ◽  
...  

Nasal polyps (NPs) are a multifactorial disorder associated with a chronic inflammatory state of the nasal mucosa. Fucoxanthin (Fx) is a characteristic orange carotenoid obtained from brown algae and has diverse immunological properties. The present study investigated whether Fx inhibits fibrosis-related effects in nasal polyp-derived fibroblasts (NPDFs) and elucidated the molecular signaling pathways involved. The production of collagen type I (Col-1) was investigated in NP tissue via immunohistochemistry and western blot analysis. NPDFs were treated with transforming growth factor (TGF)-β1 (1 ng/mL) in the presence or absence of Fx (5–30 µM). The levels of α-smooth muscle actin (α-SMA), Col-1, and phosphorylated (p)-Smad 2/3, signal protein-1 (SP-1), MAPKs (mitogen-activated protein kinases), and Akt were measured by western blot analysis. The expression of Col-1 was detected in NP tissues. TGF-β1 stimulated the production of α-SMA and Col-1, and stimulated the contraction of collagen gel. However, pretreatment with Fx attenuated these effects. Furthermore, these inhibitory effects were mediated through modulation of both Smad 2/3 and Akt/SP-1 signaling pathways in TGF-β1-induced NPDFs. The results from the present study suggest that Fx may be a novel anti-fibrotic agent for the treatment of NP formation.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1769-1769
Author(s):  
Amir Hossein Daneshmanesh ◽  
Mohammad Hojjat-Farsangi ◽  
Asa Sandin ◽  
Abdul Salam Khan ◽  
Ali Moshfegh ◽  
...  

Abstract Abstract 1769 Background: Phosphoinositide 3-kinase (PI3K)/AKT cascade regulates cell survival, proliferation and differentiation in a variety of cells. In CLL cells PI3K pathway is constitutively activated leading to AKT activation and phosphorylation of cAMP response element-binding protein (CREB). CREB is a transcription factor overexpressed and constitutively phosphorylated in a variety of cancers and seems to have a role in tumor pathobiology. There is a great need to develop novel strategies for targeted therapy in CLL. Monoclonal antibodies (mAbs) specifically targeting leukemic cells might be a rewarding approach. ROR1 is a type I transmembrane receptor tyrosine kinase belonging to one of the twenty families of receptor tyrosine kinases (RTKs). ROR1 is overexpressed on CLL cells but not in white blood cells of healthy donors. ROR1 is constitutively phosphorylated in CLL and siRNA transfection induced apoptosis. We have developed a unique anti-ROR1 mAb directed against CRD (cysteine-rich domain) of the extracellular region of ROR1 capable of inducing direct apoptosis of primary CLL cells. Our anti-CRD mAb induced dephosphorylation of the ROR1 molecule. Aims: To study the apoptotic effect of an anti-ROR1 CRD mAb and effects on downstream signaling pathways involved in CLL, specially the PI3-kinase/AKT/CREB pathway using primary CLL cells. Methods: Using a peptide-based mouse mAb generation method we produced several mAbs against the three extracellular domains of ROR1. In the current study we used one of the best anti-ROR1 antibodies, an anti-CRD mAb raised against the CRD region of ROR1 (Daneshmanesh et al., Leukemia. 2012 Jun;26(6):1348-55). Flow cytometry was used for surface staining of ROR1. Primary CLL cells were incubated with the anti-ROR1 CRD mAb and apoptosis was detected by the MTT assay and Annexin V/propidium iodide (flow cytometry) methods in a 24 h assay. Antibody untreated and treated cell lysates were prepared and subjected to Western blot analysis for identification of signaling molecules involved in apoptosis induced by the anti-ROR1 CRD mAb. We analysed total and phosphorylated levels of the following signaling proteins: AKT, p-AKT, PI3K, p-PI3K, CREB, p-CREB, ERK, p-ERK, PKC and p-PKC. Phosphoproteins were measured before incubation with the mAb and after 20 min-2 h. Results: ROR1 surface expression was detected on 80–85% of the CLL cells. The frequency of apoptotic cells induced by the anti-CRD mAb was in the range of 45–50% which is in accordance with our previous reports (see above). Time kinetics experiments using anti-ROR1 CRD mAb incubated with primary CLL cells revealed dephosphorylation of ROR1 downstream signaling molecules. We analysed the following molecules known to be involved in CLL: PKC, PI3-kinase and ERK1/2. After co-culturing CLL cells with the anti-ROR1 CRD mAb, Western blot analysis showed decreased level of phosphorylated AKT in treated compared to untreated samples. No changes in the phosphorylation levels of ERK1/2 and PKC proteins were seen. Furthermore, we analysed the PI3-kinase protein which is upstream of AKT, and noticed that in CLL cells treated with the anti-ROR1 CRD mAb, the phosphorylation intensity of PI3-kinase p85 isoform has decreased but not p55 isoforrn. Moreover, we also studied the CREB phosphorylation in treated and untreated CLL samples and detected dephosphorylation of CREB in treated as compared to untreated samples. Conclusion: Incubation of CLL cells with an anti-ROR1 CRD mAb induced apoptosis of primary CLL cells. Apoptosis was preceded by dephosphorylation within 2 h of PI3-kinase, AKT and CREB proteins indicating deactivation of these signaling proteins by the anti-ROR1 mab. In untreated CLL cells no effect on phosphorylation of these proteins was noted. Furthermore our ROR1 mAb did not dephosphorylate PKC or ERK. Our data may suggest that activation of CREB molecule might occur via the PI3K/AKT pathway and may be a survival signal in CLL cells associated with the aberrant expression of ROR1. The constitutive phosphorylation of PKC and ERK1/2 seen in CLL might not be related to the overexpression of ROR1. Further studies are warranted for a better understanding of signaling pathways associated with ROR1 and the downstream signaling effects of ROR1 targeting drugs. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ruihong Wang ◽  
Dawei Luo ◽  
Zhiwei Li ◽  
Huimin Han

Background. Oxidative stress, inflammation, and nucleus pulposus cells (NPCs) apoptosis are involved in pathogenesis of intervertebral disc (IVD) degeneration (IVDD). Dimethyl fumarate (DMF) has been found to effectively depress oxidative stress and inflammation via the Nrf2 pathway. Hence, this project was designed to explore the underlying mechanisms of how DMF protects NPCs from damage by LPS challenge. Methods and Results. CCK8 assay and flow cytometry of apoptosis indicated that DMF treatment attenuated LPS-induced NPC damage. Western blot analysis demonstrated that DMF enhanced the expressions of nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in LPS-challenged NPCs. DMF treatment significantly decreased the accumulation of ROS, downregulated inflammatory cytokines (p-NF-κB, IL-1β, and TNF-α), and ER stress-associated apoptosis proteins (Bip, calpain-1, caspase-12, caspase-3, and Bax) in LPS-challenged NPCs. The level of antiapoptotic protein Bcl-2 was promoted by DMF treatment in LPS-challenged NPCs. Glutathione (GSH) assay showed that DMF treatment improved reduced to oxidized glutathione ratio in LPS-challenged NPCs. Furthermore, the results of western blot analysis indicated that in LPS-challenged NPCs, DMF treatment ameliorated the elevated levels of matrix degradation enzymes (MMP-13, aggrecanase 1) and type I collagen and the reduced levels of matrix composition (type II collagen and ACAN). However, Nrf2 knockdown abolished these protective effects of DMF. Conclusion. Our data suggested that treatment with DMF mitigated LPS-induced oxidative stress, inflammation, and ER stress-associated apoptosis in NPCs via the Nrf2/HO-1 signaling pathway, thus reliving LPS-induced dysfunction of NPCs, which offered a novel potential pharmacological treatment strategy for IVDD.


2020 ◽  
Vol 20 (4) ◽  
pp. 429-436
Author(s):  
Roghayeh Ijabi ◽  
Parisa Roozehdar ◽  
Reza Afrisham ◽  
Hemen Moradi-Sardareh ◽  
Saeed Kaviani ◽  
...  

Introduction: Parallel with the progression of Chronic Lymphocytic Leukemia (CLL), the levels of 78KDa Glucose-Regulated Protein (GRP78) and Hypoxia-Inducible Factor 1 alpha (HIF-1α) are increased as they may activate the induction of anti-apoptotic proteins such as BCL2 Associated Athanogene 3 (BAG3). Previous studies have indicated that there is a positive correlation among GRP78, HIF-1α and BAG3. Objective: This study aimed to evaluate the effect of metabolic factors involved in invasive CLL on apoptotic factors. Methods: A case-control study was conducted on 77 patients diagnosed with CLL along with 100 healthy individuals. Cell blood count was performed for all participants. According to Binet's classification, CLL patients were divided into different groups. B cells were isolated from the peripheral blood of CLL patients by binding to anti-CD19 beads. The expression of BAG3, GRP78 and HIF-1α genes was analyzed using the RT-PCR method. To confirm the results of RT-PCR, western blot analysis was carried out. Results: The results showed that there was a strong association among the expression of BAG3, GRP78 and HIF-1α. The stage of CLL in patients was highly correlated with the expression rate of each gene (p<0.001). Accordingly, the western blot analysis indicated that the concentrations of GRP78 and HIF-1α were significantly higher than the expression of BAG3, considering the stage of CLL. Conclusion: It was shown that increased expression of GRP78 and HIF-1α could result in the elevation of BAG3, as well as the disease progression. Therefore, the role of these metabolic factors might be more pronounced compared with the anti-apoptotic agents to monitor disease progression in CLL patients.


2000 ◽  
Vol 113 (7) ◽  
pp. 1189-1198 ◽  
Author(s):  
W. Bursch ◽  
K. Hochegger ◽  
L. Torok ◽  
B. Marian ◽  
A. Ellinger ◽  
...  

Programmed cell death comprises several subtypes, as revealed by electron microscopy. Apoptosis or type I programmed cell death is characterized by condensation of cytoplasm and preservation of organelles, essentially without autophagic degradation. Autophagic cell death or type II programmed cell death exhibits extensive autophagic degradation of Golgi apparatus, polyribosomes and endoplasmatic reticulum, which precedes nuclear destruction. In the present study, we analysed the fate of cytokeratin and F-actin during autophagic cell death in the human mammary carcinoma cell line MCF-7 because recent studies suggest that an intact cytoskeleton is necessary for autophagocytosis. Programmed cell death was induced by 10(-)(6) M tamoxifen. For quantitative light microscopic analysis, autophagic vacuoles were visualized by monodansyl cadaverin, which stains autophagic vacuoles as distinct dot-like structures. In control cultures, the number of monodansylcadaverin-positive cells did not exceed 2%. Tamoxifen induced a dramatic increase 2–4 days after treatment to a maximum of 60% monodansylcadaverin-positive cells between days 5 and 7. Cell death, as indicated by nuclear condensation, increased more gradually to about 18% of all cells on day 7. In cells with pyknotic nuclei cytokeratin appeared disassembled but retained its immunoreactivity; actin was still polymerized to filaments, as demonstrated by its reaction with phalloidin. Western blot analysis showed no significant cleavage of the monomeric cytokeratin fraction. For comparison, apoptotic or type I cell death was studied using the human colon cancer cell HT29/HI1 treated with the tyrosine kinase inhibitor tyrphostin A25 as a model. Cleavage of cytokeratin was already detectable in early morphological stages of apoptosis. F-actin was found to depolymerize; its globular form could be detected by antibodies; western blot analysis revealed no products of proteolytic cleavage. In conclusion, in our model of apoptosis, early stages are associated with depolymerization of actin and degradation of intermediate filaments. In contrast, during autophagic cell death intermediate and microfilaments are redistributed, but largely preserved, even beyond the stage of nuclear collapse. The present data support the concept that autophagic cell death is a separate entity of programmed cell death that is distinctly different from apoptosis.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4381-4381
Author(s):  
Kyu-Tae Kim ◽  
Obdulio Piloto ◽  
Donald Small

Abstract Receptor tyrosine kinase FLT3 plays an important role in leukemogenesis, especially in acute myeloid leukemia (AML). Tyrosine kinase inhibitors (TKI) targeting wild-type and mutant FLT3 have been developed and shown to have activity in clinical trials. However, as seen with Gleevac in CML, prolonged incubation with TKIs can select for resistant clones that may contribute to disease progression. To study resistance to TKIs against FLT3 we developed FLT3 inhibitor resistant cell lines by co-culturing MOLM14 and BaF3/ITD cells, expressing FLT3/ITD mutants with increasing concentrations of the FLT3 inhibitor CEP-701. The resulting cell lines, MOLM14(R) and BaF3/ITD(R) are resistant to CEP-701 induced cytotoxicity. MOLM14(R) is also resistant to other selective FLT3 TKIs including CEP-5214 and PKC412. In contrast, BaF3/ITD(R) cells were still sensitive to CEP5214 and PKC412. Western blot analysis reveals that CEP-701, CEP-5214 and PKC412 all still inhibit FLT3 in MOLM14(R) cells implying selection of a clone no longer dependent on FLT3 signaling. FLT3 phosphorylation is not inhibited by CEP-701 in BaF3/ITD(R) cells but is still inhibited by CEP-5214 and PKC412. Thus the BaF3/ITD(R) cells appear to remain FLT3-dependent. Sequencing of FLT3 from the resistant clones showed that the resistance was not the result of drug resistance mutations in FLT3/ITD. To investigate possible mechanisms of resistance in FLT3-dependent and FLT3-independent FLT3 inhibitor resistant cells, we examined pathways downstream of FLT3. Previously, we and others reported that constitutive FLT3 activation results in specific changes in gene expression in myeloid leukemic cells. As expected for cells with continued FLT3/ITD activation, Western blot analysis of BaF3/ITD(R) cells treated with CEP-701 show that they maintain activation of Erk/MAPK, Akt, and STAT5 pathways and induction of FLT3 dependent genes including Pim-1 and cMyc. In the apparently FLT3-independent MOLM-14(R) clones, inhibition of FLT3 activity resulted in decreased phosphorylation of downstream Akt and Stat5. However, we found Erk/MAPK phosphorylation and cMyc expression were not decreased in response to FLT3 TKI. This implies that whatever pathway has been selected for the ability to grow in this inhibitor is still feeding into this part of the downstream signaling pathway normally activated by FLT3/ITD. Thus, BaF3/ITD(R) FLT3-dependent and MOLM-14(R) FLT3 independent cells differ in response to several FLT3 inhibitors that results from the differences in their mechanisms of resistance.


2021 ◽  
Vol 22 (10) ◽  
pp. 5074
Author(s):  
Rosalba Siracusa ◽  
Ramona D’Amico ◽  
Daniela Impellizzeri ◽  
Marika Cordaro ◽  
Alessio Filippo Peritore ◽  
...  

Endometriosis is a gynecological condition affecting patients in reproductive age. The aim of this paper was to assess the effects of the autophagy and mitophagy induction in a rat model of endometriosis. Endometriosis was induced by the injection of uterine fragments, and rapamycin (0. 5 mg/kg) was administered once per week. One week from the induction, rats were sacrificed, and laparotomy was performed to collect the endometriotic implants and to further process them for molecular analysis. Western blot analysis was conducted on explanted lesions to evaluate the autophagy pathway during the pathology. Elevated phospho-serine/threonine kinase (p-AKT) and mammalian target of rapamycin (mTOR) expressions were detected in vehicle-treated rats, while Beclin and microtubule-associated protein 1A/1B-light chain 3 II (LC3II) expressions were low. Additionally, samples collected from vehicle groups indicated low Bnip3, Ambra1, and Parkin expressions, demonstrating impaired autophagy and mitophagy. Rapamycin administration reduced p-AKT and mTOR expressions and increased Beclin and LC3II, Bnip3, Ambra1, and Parkin expressions, activating both mechanisms. We also evaluated the impact of the impaired autophagy and mitophagy pathways on apoptosis and angiogenesis. Rapamycin was administered by activating autophagy and mitophagy, which increased apoptosis (assessed by Western blot analysis of Bcl-2, Bax, and Cleaved-caspase 3) and reduced angiogenesis (assessed by immunohistochemical analysis of vascular endothelial grow factor (VEGF) and CD34) in the lesions. All of these mechanisms activated by the induction of the autophagy and mitophagy pathways led to the reduction in the lesions’ volume, area and diameter.


2007 ◽  
Vol 131 (1) ◽  
pp. 50-56
Author(s):  
Graham W. Slack ◽  
Juanita Wizniak ◽  
Laith Dabbagh ◽  
Xinzhe Shi ◽  
Pascal Gelebart ◽  
...  

Abstract Context.—Expression of ZAP-70 in chronic lymphocytic leukemia (CLL) predicts worse clinical outcome in patients with early-stage disease. It has become important to include ZAP-70 in the immunophenotyping panel used to diagnose CLL, commonly performed by flow cytometry (FC). Nevertheless, the methodology used to detect ZAP-70 by FC has not been extensively evaluated. Objective.—To describe our FC method for detecting ZAP-70 in CLL and assess whether this assay is useful in estimating the ZAP-70 protein level in CLL cells. Design.—ZAP-70 expression was assessed by FC in 45 consecutive newly diagnosed CLL patients, and the results were correlated with those of immunocytochemistry and Western blot analysis. Results.—With &gt;25% ZAP-70–positive B cells as the cutoff, the FC results had a perfect concordance with those of immunocytochemistry (39/39, 100%) and Western blot analysis (7/7, 100%). The use of autofluorescence controls was found to be superior to other alternatives. Overall, 19 (42%) of 45 cases were ZAP-70 positive in our series. Since only 7 cases (16%) had &gt;20% to 30% ZAP-70–positive B cells, the cutoff of &gt;25% readily separated CLL into positive and negative groups in most cases. ZAP-70 positivity was significantly associated with atypical morphology but not other laboratory parameters evaluated. Conclusions.—With proper specimen processing and the use of directly fluorescence-conjugated anti–ZAP-70 antibody, one can readily incorporate ZAP-70 into the routine FC study panel for CLL. Our data suggest that FC is a rapid and useful method to estimate the ZAP-70 protein expression level in CLL.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Yang Zhang ◽  
Xiang Li ◽  
Xiao-Xue Li ◽  
Ashley L Pitzer ◽  
Pin-Lan Li

Retinoic acid-inducible gene-I (RIG-I) is a putative RNA helicase and recently identified as a cytosolic RNA receptor in mammalian cells. The role of RIG-I in the regulation of vascular function under physiological and pathological conditions is unknown. The present study tested whether RIG-I activation triggers inflammasome formation, turning on inflammation in mouse endothelial cells (EOMA cell line). By real time RT-PCR and Western blot analysis, transfection of mouse ECs with RIG-I specific agonist, 5’-triphosphate double-stranded RNA (3pRNA, 0.5 mg/L) increased RIG-I mRNA level by 106% and protein level by 81% compared to those in control double-stranded RNA (dsRNA) transfected ECs. ELISA analyses showed that 3pRNA significantly increased release of type I IFN alpha by 31 folds and IL-1 beta (a prototype cytokine from inflammasome activation) by 8 folds in these ECs. Proatherogenic stimulation of mouse ECs with cholesterol crystals or 7-ketocholesterol also markedly increased protein expression of RIG-I, but had no effect on RIG-I mRNA levels. Measurements of active caspase-1, an inflammasome activation marker using FLICA fluorescent probe that specifically binds to cleaved caspase-1, demonstrated that 3pRNA doubled FLICA positive cells compared to that in control dsRNA transfected ECs. Interestingly, cholesterol crystals significantly increased FLICA positive cells by 3 folds. This activation of caspase-1 in ECs by cholesterol crystals was further confirmed by increase in cleaved caspase-1 (p10) using Western blot analysis and by enhanced IL-1 beta release as detected by ELISA. In the presence of 3pRNA, cholesterol crystal-induced inflammasome activation was not further augmented. These data indicate that increased expression and activity of RIG-I activate IL-1 beta producing inflammasomes in ECs, which may represent an early molecular mechanism mediating vascular inflammation or injury upon atherogenic stimulations.


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