scholarly journals Assessment of PI3K/mTOR/AKT Pathway Elements to Serve as Biomarkers and Therapeutic Targets in Penile Cancer

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2323
Author(s):  
Anita Thomas ◽  
Sascha Reetz ◽  
Philipp Stenzel ◽  
Katrin Tagscherer ◽  
Wilfried Roth ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Lines ◽  
Penile Cancer ◽  
Multivariate Regression Analysis ◽  
Clinicopathological Characteristics ◽  
Akt Pathway ◽  
Akt Inhibitor ◽  
Free Survival ◽  
Kaplan Meier ◽  
Treatment Naïve

The PI3K/mTOR/AKT pathway might represent an intriguing option for treatment of penile cancer (PeCa). We aimed to assess whether members of this pathway might serve as biomarkers and targets for systemic therapy. Tissue of primary cancer from treatment-naïve PeCa patients was used for tissue microarray analysis. Immunohistochemical staining was performed with antibodies against AKT, pAKT, mTOR, pmTOR, pS6, pPRAS, p4EBP1, S6K1 and pp70S6K. Protein expression was correlated with clinicopathological characteristics as well as overall survival (OS), disease-specific survival (DSS), recurrence-free survival (RFS) and metastasis-free survival (MFS). AKT inhibition was tested in two primarily established, treatment-naïve PeCa cell lines by treatment with capivasertib and analysis of cell viability and chemotaxis. A total of 76 patients surgically treated for invasive PeCa were included. Higher expression of AKT was significantly more prevalent in high-grade tumors and predictive of DSS and OS in the Kaplan–Meier analysis, and an independent predictor of worse OS and DSS in the multivariate regression analysis. Treatment with pan-AKT inhibitor capivasertib in PeCa cell lines induced a significant downregulation of both total AKT and pAKT as well as decreased cell viability and chemotaxis. Selected protein candidates of the mTOR/AKT signaling pathway demonstrate association with histological and survival parameters of PeCa patients, whereas AKT appears to be the most promising one.

Rituximab-Mediated Inhibition of the PI3K-Akt Survival Signaling Pathway in B-NHL Cell Lines Leading to Downregulation of Bclxl Expression and Chemosensitization.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2830-2830
Author(s):  
Eriko Suzuki ◽  
Ali R. Jazirehi ◽  
Benjamin Bonavida
Keyword(s):  
Cell Survival ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Kinase Inhibitor ◽  
Akt Pathway ◽  
Akt Inhibitor ◽  
Drug Induced ◽  
Similar Time ◽  
Cell Lysates ◽  
Induced Apoptosis

Abstract Rituximab (chimeric anti-CD20 monoclonal antibody) has been used in the treatment of B-NHL. We have reported in vitro that rituximab treatment signals B-NHL cell lines Ramos and Daudi and inhibits both the ERK 1/2 MAPK and NF-κB signaling pathways leading to selective inhibition of Bclxl expression and sensitization to drug-induced apoptosis. The inhibition of the NF-κB signaling pathway by rituximab was shown to be due, in part, to the induction of the Raf Kinase Inhibitor Protein (RKIP) (Jazirehi, et al., 2005 Cancer Research 65:264–276). The PI3K-Akt signaling pathway is a key regulator of cell survival and aberrant activation of the PI3K-Akt pathway has been implicated in both drug resistance and resistance to apoptosis-inducing stimuli. Akt can promote cell survival by indirectly activating the proximal transcription factor NF-κB through the phosphorylation of I-kappa B kinase (I-κB) (Ozes et. al. Nature401:82–85, 1999). This study investigated whether NF-κB inhibition by rituximab and downregulation of Bclxl expression was also the result of rituximab-mediated inhibition of the PI3K-Akt pathway. Ramos and Daudi B-NHL cell lines were treated with rituximab (20 ug/ml) and cell lysates were prepared and both Akt and phospho-Akt (p-Akt) expression were examined by western blot. The findings demonstrate that both cell lines show constitutively activated p-Akt and treatment with rituximab significantly inhibited p-Akt but not Akt. Time kinetics analysis demonstrated that inhibition of p-Akt was first detected at 3–6 hours following rituximab treatment and inhibition was maintained up to 24 hours. Concomitantlly, a similar time kinetics revealed inhibition of NF-κB activity as assessed by EMSA. Since the inhibition of NF-kB activity resulted in significant downregulation of Bclxl expression, we also examined the role of the Akt pathway in the regulation of Bclxl expression. Tumor cells were treated with the Akt inhibitor LY294002 and analysis of cell lysates showed significant downregulation of Bclxl expression. Rituximab was previously shown to sensitize B-NHL cells to drug-induced apoptosis via inhibition of NF-κB activity and Bclxl expression. We examined if inhibition of the Akt pathway also chemosensitized the cells. Treatment of Ramos cells with the Akt inhibitor LY294002 significantly sensitized the cells to CDDP-induced apoptosis and synergy was achieved. Altogether, these findings demonstrate, for the first time, that rituximab inhibits the Akt pathway and that this pathway is involved in the regulation of tumor- cell resistance to chemotherapeutic drugs. This study also proposes that the Akt pathway is a potential targeting pathway for therapeutic intervention in the treatment of rituximab and drug-resistant B-NHL.

scholarly journals Transarterial Chemoembolization Combined with Radiofrequency Ablation in the Treatment of Stage B1 Intermediate Hepatocellular Carcinoma

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Furong Liu ◽  
Minshan Chen ◽  
Jie Mei ◽  
Li Xu ◽  
Rongping Guo ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Radiofrequency Ablation ◽  
Transarterial Chemoembolization ◽  
Progression Free Survival ◽  
Intermediate Stage ◽  
Multivariate Regression Analysis ◽  
Rank Test ◽  
Free Survival ◽  
Kaplan Meier ◽  
Tace Group

Background. Due to the heterogeneity of patients with Barcelona clinic liver cancer (BCLC) intermediate-stage hepatocellular carcinoma (HCC), Bolondi criteria were proposed and patients were divided into four substages. The purpose of this study was to compare the survival of substage B1 patients who were initially treated with a combination of transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) (TACE-RFA) or TACE alone. Methods. 404 patients with stage B1 HCC were retrospectively analyzed from January 2005 to December 2012. 209 patients received TACE-RFA, and 195 received TACE alone as initial treatment. The overall survival (OS) and progression-free survival (PFS) rates were estimated by the Kaplan–Meier method and compared by the log-rank test. Results. 1-, 3-, and 5-year OS rates were 83.7%, 45.8%, and 24.8% in the TACE-RFA group and 80.7%, 26.4%, and 16.7% in the TACE group, respectively (P=0.003). The corresponding PFS rates were 71.8%, 26.6%, and 13.0% and 59.1%, 11.0%, and 2.2% in the TACE-RFA group and TACE group, respectively (P<0.001). Multivariate regression analysis indicated that tumor size (OS: hazard ratio (HR) = 0.683, P=0.001; PFS: HR = 0.761, P=0.013), along with treatment allocation (OS: HR = 0.701, P=0.003; PFS: HR = 0.620, P<0.001), was the independent prognostic factor for both OS and PFS. Conclusions. Combination TACE and RFA treatment yielded better survival than TACE alone for patients with stage B1 HCC according to the Bolondi criteria.

scholarly journals Transient Receptor Potential Mucolipin-1 Channels in Glioblastoma: Role in Patient’s Survival

Cancers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 525 ◽  
Author(s):  
Maria Beatrice Morelli ◽  
Consuelo Amantini ◽  
Daniele Tomassoni ◽  
Massimo Nabissi ◽  
Antonella Arcella ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Lines ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
U251 Cell ◽  
Mediated Effects ◽  
Kaplan Meier ◽  
Negative Prognostic Factor ◽  
Carbonyl Cyanide ◽  
Transient Receptor

A link between mucolipin channels and tumors has been recently suggested. Herein, we aim to investigate the transient receptor potential mucolipin (TRPML)-1 relevance in glioblastoma. The expression of this channel was evaluated via qRT-PCR and immunohistochemistry in biopsies from 66 glioblastoma patients and two human glioblastoma cell lines and compared to normal human brain, astrocytes, and epileptic tissues. The subcellular distribution of TRPML-1 was examined via confocal microscopy in the glioma cell lines. Then, to assess the role of TRPML-1, cell viability assays have been conducted in T98 and U251 cell lines treated with the specific TRPML-1 agonist, MK6-83. We found that MK6-83 reduced cell viability and induced caspase-3-dependent apoptosis. Indeed, the TRPML-1 silencing or the blockage of TRPML-1 dependent [Ca2+]i release abrogated these effects. In addition, exposure of glioma cells to the reactive oxygen species (ROS) inducer, carbonyl cyanide m-chlorophenylhydrazone (CCCP), stimulated a TRPML-1-dependent autophagic cell death, as demonstrated by the ability of the autophagic inhibitor bafilomycin A, the TRPML-1 inhibitor sphingomyelin, and the TRPML-1 silencing to completely inhibit the CCCP-mediated effects. To test a possible correlation with patient’s survival, Kaplan–Meier, univariate, and multivariate analysis have been performed. Data showed that the loss/reduction of TRPML-1 mRNA expression strongly correlates with short survival in glioblastoma (GBM) patients, suggesting that the reduction of TRPML-1 expression represents a negative prognostic factor in GBM patients.

Constitutive Activation of AKT Contributes to the Pathogenesis and Survival of Blastoid Variants of Mantle Cell Lymphoma.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1908-1908
Author(s):  
Martina Rudelius ◽  
Stefania Pittaluga ◽  
Trinh H.-T. Pham ◽  
Thomas Fountaine ◽  
Leticia Quintanilla-Martinez ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Kinase ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Regulatory Proteins ◽  
Akt Pathway ◽  
Akt Inhibitor ◽  
Akt Activation ◽  
Constitutive Activation ◽  
Mantle Cell

Abstract The serine/threonine protein kinase AKT [protein kinase B (PKB)] plays a pivotal role in the tumorigenesis of many human malignancies, including hematopoietic neoplasms. AKT mediates cancer cell survival and cell growth through the phosphorylation of key regulatory proteins such as FRKHL-1, MDM2 and p27. We wished to determine whether the AKT signaling pathway might be involved in the pathogenesis of mantle cell lymphoma (MCL).The activated form of AKT (pAKT) and phosphorylation of several AKT targets, including FRKHL-1, MDM2 and p27 as well as the upstream modulators PTEN and TCL-1 were analyzed by immunoblotting in 31 MCL cases (16 classic MCL and 15 MCL of the blastoid variant) and in four MCL cell lines (Granta 519, NCEB, REC-1 and Z138). PI3KCA mutation analysis at two hotspot regions (Exons 9 and 20) were completed for all cases and cell lines. Subsequently, inhibition of the PIK3/AKT-pathway with LY294002, Wortmannin and AKT-inhibitor was performed in the four cell lines. pAKT was expressed in all 15 blastoid variants of MCL and in the 4 cell lines, with high expression in 13/15 cases and low expression in 2/15 cases. In contrast, only 2/16 typical MCL expressed pAKT, at low levels. Furthermore, pAKT expression in the blastoid variants and cell lines was accompanied by the phosphorylation of multiple downstream targets of activated AKT, including the cell cycle regulatory proteins p27, FRKHL-1, MDM-2 and the apoptosis associated protein bad. 42% of the blastoid MCL cases showed loss of PTEN, while only 2 (12%) of the typical cases showed diminished PTEN expression.TCL-1 expression levels were not correlated with AKT activation and no mutations of PI3KCA were detected. Functional studies of all four MCL lines demonstrated that the phosphorylation of the downstream effectors were regulated by activated AKT:Inhibition of the PI3K/AKT pathway by both 20 μM LY294002 and 8 μM Wortmannin or 40 μM AKT-inhibitor abrogated the phosphorylation of AKT, p27, FRKHL-1, bad and MDM2 after 24 to 48 hours of treatment, and resulted in G1 arrest after 24 hours of treatment and measurable apoptosis by 48 hours. We conclude that constitutive activation of AKT contributes to the pathogenesis of the blastoid variants of MCL. One possible mechanism of AKT activation is the loss of PTEN expression. The inhibition of the PIK3/AKT pathway in MCL cell lines leads to induction of cell cycle arrest and apoptosis, raising the possibility that PI3K/AKT inhibitors may be effective in the treatment of aggressive (blastoid) variants of MCLs.

Perifosine, an Oral Bioactive Novel Akt Inhibitor, Induces In Vitro and In Vivo Antitumor Activity in Waldenstrom Macroglobulinemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2488-2488 ◽  
Author(s):  
Xavier Leleu ◽  
Xiaoying Jia ◽  
Anne-Sophie Moreau ◽  
Evdoxia Hatjiharisi ◽  
Hai Ngo ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Antitumor Activity ◽  
Dna Synthesis ◽  
Cell Lines ◽  
Akt Pathway ◽  
Low Grade ◽  
Akt Inhibitor ◽  
Induced Apoptosis

Abstract Background: Waldenstrom’s Macroglobulinemia (WM) is a low-grade lymphoplasmacytic lymphoma with limited options of therapy. The PI3k/Akt pathway is a critical regulator of cell survival. Our previous studies using proteomic analysis have demonstrated upregulation of members of the PI3k/Akt pathway in WM. We examined whether the new Akt inhibitor perifosine (NSC 639966; Keryx, NY) induces cytotoxicity in WM. Methods: WM cell lines (BCWM1 and WSU-WM) and IgM secreting low-grade lymphoma cell lines (MEC1, RL) were used. Primary CD19+ malignant cells were obtained from patients after informed consent. Inhibition of proliferation was measured using the MTT assay; DNA synthesis was measured using the thymidine uptake assay and apoptosis using Apo2.7 flow cytometry. Bone marrow stromal cells (BMSC) confer growth and resistance to conventional treatments. We therefore, tested the effect of perifosine on WM cells co-cultured with BMSC. Immunoblotting for signaling pathways was performed at different time (30 minutes to 16 hrs) and doses of therapy. In vivo activity of perifosine was assessed using a SCID-irradiated model with subcutaneous tumors in which perifosine was administered by oral gavage daily (35 mg/kg/day). A two-sided t-test was used to determine statistical differences. Results: Perifosine inhibited phosphorylation of Akt in a dose- and time- dependent fashion, as well as downstream GSK3a/b and ribosomal phospho-S6. Perifosine inhibited Akt activity as confirmed by Akt kinase assay. Perifosine induced significant cytotoxicity and inhibition of DNA synthesis with an IC50 of 5-20uM in all cell lines tested. Similar effects were observed in primary CD19+ patient WM cells. Perifosine induced apoptosis in WM cells as demonstrated by flow cytometry. The mechanism of apoptosis induced by perifosine was through activation of SAPK/JNK pathway, followed by caspase-8, -9 and PARP cleavage. The JNK inhibitor SP600125 abrogated perifosine-induced apoptosis. The growth inhibitory effects of perifosine were significant even in the presence of BMSC, IL-6 and IGF-1, which induce resistance to conventional therapies. Importantly, perifosine did not induce cytotoxicity in healthy donor peripheral blood mononuclear cells or in hematopietic stem cells in a methylcellulose colony forming cell assay, indicating lack of toxicity on normal cells. Interestingly, MAPK members such as MEK/ERK were activated by perifosine. The MEK inhibitor U0126 significantly enhanced perifosine-induced cytotoxicity in WM cells, indicating that this combination may be synergistic in vivo. Finally, perifosine induced significant reduction in WM tumor growth in vivo, as compared to control cohort treated with vehicle only at week 6 (p=0.05). Conclusion: Perifosine has significant antitumor activity in WM both in vitro and in vivo. These results provide the framework for clinical evaluation of perifosine in WM. Supported in part by the Leukemia and Lymphoma Society, the Lymphoma Research Foundation and an American Society of Hematology Scholar Award. * XL and XJ are co-first authors.

Analysis of PKB/Akt-Signaling and Oncogenic Ras in Multiple Myeloma.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 831-831
Author(s):  
Torsten Steinbrunn ◽  
Thorsten Stühmer ◽  
Manik Chatterjee ◽  
Stefan Gattenlöhner ◽  
Ralf C Bargou
Keyword(s):  
Multiple Myeloma ◽  
Cell Line ◽  
Cell Lines ◽  
Annexin V ◽  
Akt Pathway ◽  
Akt Inhibitor ◽  
Mutation Status ◽  
Ras Mutations ◽  
Constitutive Activation ◽  
Oncogenic Ras

Abstract Abstract 831 Introduction: Dysregulated signaling pathways contribute to cell growth, survival and drug resistance in multiple myeloma (MM). In about 50 percent of primary MM samples the protein kinase B (PKB)/Akt pathway appears to be constitutively active and its blockade strongly impairs survival, thus defining Akt-dependent versus Akt-independent MM. Because illegitimate activation of survival pathways can be a consequence of oncogenic Ras mutations, we analyzed the role of Ras in Akt-dependent primary MM samples. Methods: Primary MM samples from different patients (n=35) were tested for cell death induction with the small molecule Akt-inhibitor Akti 1/2 and the sensitivity was correlated to the mutation status of N- or K-Ras in these samples, which was obtained by RT-PCR. Immunohistochemistry was used to demonstrate the presence of phosphorylated Akt in corresponding patient biopsies. Apoptosis was measured by flow cytometry with Annexin V-APC or Annexin V-FITC and propidium-iodide staining. We further analyzed the consequences of Ras depletion with regard to Akt activation in a Ras wildtype (AMO-1) versus a K-Ras mutated (MM.1s) and an N-Ras mutated (INA-6) myeloma cell line using siRNA knockdown and Western blotting. Isoform specificity of the siRNAs was confirmed through the effects on ectopically expressed HA-tagged Ras proteins. Results: Of the 35 primary MM samples tested 17 (48.6%) showed sensitivity to pharmacologic inhibition of Akt and thus constituted the Akt-dependent myeloma subgroup. Activating mutations of either K-Ras (n=7) or N-Ras (n=7) were found in 14 samples (40%). However, we did not observe any obvious correlation between the mutation status of Ras and sensitivity to the Akt inhibitor, suggesting that oncogenic Ras is not a prerequisite for the constitutive activation of Akt. We extended our analysis to MM cell lines and performed isoform-specific siRNA mediated Ras knockdown. Depletion of K-Ras induced apoptosis selectively in K-Ras mutated MM.1s cells, while N-Ras mutated INA-6 cells were most sensitive to N-Ras knockdown. Contrarily, knockdown of either of these isoforms had no effect on survival in the Ras wildtype cell line AMO-1. Ras knockdown did not lead to a notable decrease in Akt(Ser473) phosphorylation, again indicating that oncogenic Ras signaling may not be mediated through the PKB/Akt-pathway in MM. Conclusion: Whereas MM cell survival might well be promoted by activating Ras mutations, oncogenic Ras does not appear to be instrumental in the constitutive activation of the PKB/Akt pathway in primary MM. Targeting Ras isoforms themselves can, however, lead to apoptosis in Ras mutated MM cell lines. Thus, even though oncogenic mutated Ras is currently not a druggable target, these experiments underscore that it is nonetheless desirable to develop ways to specifically block its function in MM. Disclosures: No relevant conflicts of interest to declare.

High Expression of NEK2 Induces Drug Resistance by Inhibiting Premature Senescence Through Activation of the PI3K/Akt Pathway in Myeloma and Other Cancers,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3923-3923
Author(s):  
Fenghuang Zhan ◽  
Fang Xiao ◽  
Maurizio Zangari ◽  
Hongwei Xu ◽  
Guido J. Tricot
Keyword(s):  
Drug Resistance ◽  
Mouse Model ◽  
Cancer Cells ◽  
Cell Lines ◽  
Conflicts Of Interest ◽  
Autologous Transplantation ◽  
Akt Pathway ◽  
Proliferative Potential ◽  
Premature Senescence ◽  
Akt Inhibitor

Abstract Abstract 3923 Background: Autologous transplantation in combination with the newer drugs has significantly prolonged survival of patients with myeloma (MM). However, the majority of patients still relapses. Our previous study has shown that NEK2, a chromosomal instability (CIN) gene, is up-regulated in many types of cancer cells and is highly related to drug resistance. Recently, premature senescence has been determined to be an indicator of the efficacy of anti-cancer drugs. In this study, we investigate the correlation between the inhibition of premature senescence and NEK2 induced drug resistance. Materials and Methods: Four MM cell lines (Δ47, KMS28PE, ARP1 and U266) and 2 other cancer cell lines (MCF7, H1299) over- and under-expressing NEK2 using a lentiviral delivery system were studied. NEK2 induced drug resistance was evaluated by colonogenic and standard apoptotic assays. The phenotypic changes of premature senescence were determined by using SA β-galactosidase (SA β-gal) staining. The mechanisms of NEK2-induced anti-senescence activity were studied in vitro and in the 5TGM1 murine MM mouse model. Results: Over-expression of NEK2 stimulated cancer cells into increased S and G2/M phase, resulting in polyploidy. All NEK2 over-expressing cancer cells were able to override doxorubicin-induced premature senescence and to maintain their proliferative potential. Mechanistic studies revealed that NEK2 activated the PI3K/Akt pathway. This was confirmed by the use of a specific PI3K/Akt inhibitor, KP372-1, which abrogated NEK2-induced drug resistance by decreasing clonogenicity of NEK2 over-expressing cells and by decreasing tumor burden and extending mouse survival in the 5TGM1 myeloma mouse model even better than bortezomib. In contrast, knockdown NEK2 by shRNA also induced premature senescence. We determined that NEK2 activates PI3K/Akt pathway by directly interacting with pp1. And the Akt down-stream targets GSK-3, MDM2, NF-kB and the tumor suppressor genes p53, p21, p27, the pro-apoptotic and pro-survival genes of the Bcl-2 family as well as the ABC transporters that related to drug resistance were identified to contribute to the inhibition of premature senescence resulting in drug resistance. Conclusion: NEK2 inhibits doxorubicin-induced premature senescence, resulting in increased drug resistance by activating the PI3K/Akt pathway. Alternatively, down regulation of NEK2 by shRNA inhibits cell proliferation and decreases drug resistance. Thus, targeting PI3K/Akt pathway should eliminate NEK2 induced drug resistance by re-establishing drug-induced premature senescence. Disclosures: No relevant conflicts of interest to declare.

Preclinical modeling of the AKT inhibitor MK2206 and topotecan in small cell lung cancer (SCLC).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e17537-e17537
Author(s):  
William S. Holland ◽  
Danielle C. Chinn ◽  
Primo Lara ◽  
David R. Gandara ◽  
Philip C Mack ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Antitumor Activity ◽  
Small Cell Lung Cancer ◽  
Cell Lines ◽  
Single Agent ◽  
Small Cell ◽  
Akt Pathway ◽  
Wild Type ◽  
Small Cell Lung ◽  
Akt Inhibitor

e17537 Background: Extensive-stage small cell lung cancer (SCLC) is an aggressive and lethal tumor. Despite its exquisite chemosensitivity, median survival is only 9-11 months. Topotecan is the only approved drug for relapsed SCLC and new treatments with demonstrated antitumor activity are urgently needed. Defects in PTEN and PI3KCA are common to SCLC (identified in 10-15% of tumor specimens), suggesting that inhibitors of the PI3K/AKT pathway should be evaluated. MK-2206 is a first- in-class oral allosteric AKT inhibitor that is both potent and highly selective against all AKT isoforms. Our aim is to determine if MK-2206 plus topotecan has superior anticancer activity compared to either agent alone in SCLC cell lines. Methods: Three SCLC cell lines (H526- PTEN/PI3K wild type; H69- PTEN wild type/PI3K mutated; H2196- PTEN mutated/PI3K wild type) were treated with MK2206, topotecan or the combination. Median Effect Analysis was conducted using proliferation assays to test the combination for synergy. Immunoblotting was performed to explore the targeted effect on the PI3K/AKT pathway while flow cytometry was used to determine cell cycle effects. Results: H526 cells were refractory to selective AKT inhibition, but sensitive to topotecan. In contrast, H69 cells were responsive to single-agent MK2206, but two orders of magnitude less sensitive to topotecan. The H2196 cell line was sensitive to both agents. All cell lines showed decreased phosphoAKT (S473) with MK2206. In the combination experiments, additive to moderately synergistic interactions were detected in all cell lines with the greatest synergism observed in the H69 cells. Increased PARP cleavage was observed in response to the combination treatment compared to single-agent topotecan suggesting that AKT inhibition improved the activity of topotecan. In H69, a prolonged G1/S-phase arrest was observed in the combination compared to single-agent treatment. Conclusions: MK2206 demonstrated antitumor activity in SCLC cell lines harboring PI3K or PTEN mutations and enhanced the activity of topotecan in wild type and mutant cell lines. Based on this data, a SWOG clinical trial of topotecan plus MK2206 versus topotecan in relapsed SCLC is in development.

scholarly journals Therapeutic targeting of ARID1A and PI3K/AKT pathway alterations in cholangiocarcinoma

PeerJ ◽  
2022 ◽  
Vol 10 ◽  
pp. e12750
Author(s):  
Supharada Tessiri ◽  
Anchalee Techasen ◽  
Sarinya Kongpetch ◽  
Achira Namjan ◽  
Watcharin Loilome ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Genomics ◽  
Genetic Alterations ◽  
Control Treatment ◽  
Akt Pathway ◽  
Missense Mutations ◽  
Akt Inhibitor ◽  
Western Blots ◽  
Increased Sensitivity ◽  
Induced Apoptosis

Background Genetic alterations in ARID1A were detected at a high frequency in cholangiocarcinoma (CCA). Growing evidence indicates that the loss of ARID1A expression leads to activation of the PI3K/AKT pathway and increasing sensitivity of ARID1A-deficient cells for treatment with the PI3K/AKT inhibitor. Therefore, we investigated the association between genetic alterations of ARID1A and the PI3K/AKT pathway and evaluated the effect of AKT inhibition on ARID1A-deficient CCA cells. Methods Alterations of ARID1A, PI3K/AKT pathway-related genes, clinicopathological data and overall survival of 795 CCA patients were retrieved from cBio Cancer Genomics Portal (cBioPortal) databases. The association between genetic alterations and clinical data were analyzed. The effect of the AKT inhibitor (MK-2206) on ARID1A-deficient CCA cell lines and stable ARID1A-knockdown cell lines was investigated. Cell viability, apoptosis, and expression of AKT signaling were analyzed using an MTT assay, flow cytometry, and Western blots, respectively. Results The analysis of a total of 795 CCA samples revealed that ARID1A alterations significantly co-occurred with mutations of EPHA2 (p < 0.001), PIK3CA (p = 0.047), and LAMA1 (p = 0.024). Among the EPHA2 mutant CCA tumors, 82% of EPHA2 mutant tumors co-occurred with ARID1A truncating mutations. CCA tumors with ARID1A and EPHA2 mutations correlated with better survival compared to tumors with ARID1A mutations alone. We detected that 30% of patients with PIK3CA driver missense mutations harbored ARID1A-truncated mutations and 60% of LAMA1-mutated CCA co-occurred with truncating mutations of ARID1A. Interestingly, ARID1A-deficient CCA cell lines and ARID1A-knockdown CCA cells led to increased sensitivity to treatment with MK-2206 compared to the control. Treatment with MK-2206 induced apoptosis in ARID1A-knockdown KKU-213A and HUCCT1 cell lines and decreased the expression of pAKTS473 and mTOR. Conclusion These findings suggest a dependency of ARID1A-deficient CCA tumors with the activation of the PI3K/AKT-pathway, and that they may be more vulnerable to selective AKT pathway inhibitors which can be used therapeutically.

M2 Macrophages, but Not M1 Macrophages, Support Megakaryopoiesis Via up-Regulating PI3K-AKT Pathway

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 1-1
Author(s):  
Hong-Yan Zhao ◽  
Qi Wen ◽  
Zhong-Shi Lyu ◽  
Shu-Qian Tang ◽  
Yuan-Yuan Zhang ◽  
...  
Keyword(s):  
Platelet Count ◽  
Cell Lines ◽  
Conflicts Of Interest ◽  
Polarization State ◽  
Graft Function ◽  
Underlying Mechanism ◽  
Akt Pathway ◽  
Monocyte Subsets ◽  
Akt Inhibitor ◽  
Cd34 Cells

Background Megakaryopoiesis and platelets production intensely depend on bone marrow(BM) microenvironment. Our previous studies found that impaired BM microenvironment and dysfunctional megakaryopoiesis are responsible for the occurrence of prolonged isolated thrombocytopenia (PT), which is defined as the engraftment of all peripheral blood cell lines other than a platelet count less than 20×109/L or a dependence on platelet transfusions for more than 60 days following allo-HSCT(BBMT 2014; BBMT 2017; Brit J Haematol 2018; Am J Hematol 2018). As an important component of the BM microenvironment, macrophages (MՓs) are heterogeneous and polarized into classically activated (M1) MՓs and alternatively activated (M2) MՓs with distinct phenotypes and function. Although inconsistent effect of BM MՓs was reported on megakaryopoiesis, the functional role of M1 and M2 MՓs and related pathway in regulating megakaryopoiesis and its effect on PT patients post-allotransplant remain to be elucidated. Aims To address the roles of M1 MФs and M2 MФs in regulating megakaryopoiesis as well as PI3K-AKT pathway in the process. Moreover, polarization status and the function of BM MФs in regulating megakaryopoiesis were evaluated in PT patients. Methods This prospective nested case-control study enrolled 12 patients with PT, 24 matched patients with good graft function (GGF), defined as persistent successful engraftment after allotransplant, and 12 healthy donors (HD). BM standard monocyte subsets and M1/M2 MՓs polarization state were analyzed by flow cytometry. To generate M1 and M2 MՓs, both primary BM MՓs and THP1 cell lines were treated with LPS and IFN-γ or with IL-4 and IL-13. The functions of BM MՓs were evaluated by migration, phagocytosis and cytokine secretion assay. The sorted CD34+ cells from HD were co-cultured with BM MՓs from PT and GGF patients or M1 and M2 MՓs respectively for megakaryopoiesis. The quantification of the megakaryocytes(MKs), MKs apoptosis, MKs polyploidy distribution, colony-forming unit MK(CFU-MK) efficiency, and platelet production were analyzed in the coculture system. To understand the underlying mechanism of MՓs polarization in regulating MKs, RNA-seq analyses were performed in BM MՓs from PT and GGF patients. In addition, M1 and M2 MՓs were treated with the chemical inhibitors and lentivirus for PI3K-AKT pathway. Results Elevated intermediate and non-classical monocyte subsets were found in PT patients when compared with those in GGF patients. Moreover, PT patients displayed increased M1 and reduced M2 MՓs, resulting an unbalanced M1/M2 polarization, compared with GGF and HD. BM MՓs from PT patients, with high TNF-α levels and low TGF-β levels, showed decreased megakaryopoiesis-supporting ability. No significant differences in migration and phagocytosis function of MՓs among the three groups. RNA sequencing of BM MՓs showed down-regulated PI3K-AKT pathway in MՓs of PT patients compared with GGF. Consistently, the phosphorylation levels of AKT decreased significantly in MՓs of PT patients, suggesting that PI3K-AKT pathway may functionally regulate megakaryopoiesis-supporting ability of MՓs. Subsequently, BM-M2 and THP1-M2 showed superior effect on megakaryopoiesis-supporting ability compared with BM-M1 and THP1-M1. Specifically, the BM CD34+ cells cocultured with M2 MՓs demonstrated significant increased percentages of MKs and MK polyploidy, CFU-MK efficiency, and platelet count compared with those cocultured with M1 MՓs. Preventing PI3K-AKT pathway by PI3K inhibitor or Akt inhibitor significantly reduced the megakaryopoiesis-supporting ability of M2 MՓs. Moreover, knockdown of AKT1 induced the impairment of megakaryopoiesis-supporting ability via suppressing M2 MՓs polarization, which could be attenuated by AKT1 overexpression complementarily. Summary/Conclusion The current study demonstrated the polarization status of MՓs modulates their ability to support megakaryopoiesis. M2 MՓs, but not M1 MՓs, support megakaryopoiesis via up-regulating PI3K-AKT pathway. Defective M2 MՓs polarization via down-regulating PI3K-AKT pathway may be responsible for the pathogenesis of PT post-allotransplant, which provides a promising therapeutic target for PT patients. Disclosures No relevant conflicts of interest to declare.

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