scholarly journals The Role of mTOR Inhibitors for the Treatment of B-Cell Lymphomas

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Pinelopi Argyriou ◽  
Panagiota Economopoulou ◽  
Sotirios Papageorgiou
Keyword(s):  
B Cell ◽  
Mammalian Target Of Rapamycin ◽  
Treatment Strategies ◽  
Mtor Inhibitors ◽  
B Cell Lymphomas ◽  
Lymphoid Malignancies ◽  
Cellular Pathways ◽  
New Treatment ◽  
Mtor Activity

Despite the fact that the majority of lymphomas initially respond to treatment, many patients relapse and die from disease that is refractory to current regimens. The need for new treatment strategies in lymphomas has led to the investigation and evaluation of novel agents that target cellular pathways. The mammalian target of rapamycin (mTOR) is a representative pathway that may be implicated in lymphomagenesis. Rapamycin and especially its derivatives (temsirolimus, everolimus, and deforolimus) represent the first described mTOR inhibitors. These agents have shown promising results in the treatment of lymphoid malignancies. On the other hand, new ATP-competitive mTOR inhibitors that provoke a broader inhibition of mTOR activity are in early stages of clinical development. The purpose of this paper is to summarize the existing knowledge about mTOR inhibitors and their use in the treatment of B-cell lymphomas. Relevant issues regarding mTOR biology in general as well as in B-cell lymphoid neoplasms are also discussed in short.

scholarly journals Silencing of MEG3 attenuated the role of lipopolysaccharides by modulating the miR-93-5p/PTEN pathway in Leydig cells

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xu Zhou ◽  
Jingliang He ◽  
Jinbo Chen ◽  
Yu Cui ◽  
Zhenyu Ou ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Apoptosis ◽  
Leydig Cells ◽  
Treatment Strategies ◽  
Pten Expression ◽  
Luciferase Reporter ◽  
Western Blots ◽  
New Treatment ◽  
Lps Treatment

Abstract Background Leydig cells reflect the activation of inflammation, decrease of androgen production, inhibition of cell growth and promotion of cell apoptosis under orchitis. Maternally expressed gene 3 (MEG3) exerts a crucial role in various human diseases, but under orchitis, the role and underlying molecular mechanism of MEG3 in Leydig cells remain unclear. Methods Lipofectamine 2000 was used for the cell transfections. qPCR and western blots assay were applied to assess the gene expression. ELISA assay was used to measure the TNFα, IL6 and testosterone secretion. CCK8 and EdU assay was employ to test the cell viability and proliferation respectively. Luciferase reporter and RIP assay were introduced to detect the binding of miR-93-5p with MEG3 and PTEN. Results Lipopolysaccharides (LPS) induced TNFα and IL6 secretion, lowered testosterone production, inhibited cell viability and proliferation, and induced cell apoptosis in Leydig cells. MEG3 was upregulated in Leydig cells treated with LPS and that knockdown of MEG3 inhibited the role of LPS in Leydig cells. MEG3 absorbed miR-93-5p and that suppression of miR-93-5p restored the role of silenced MEG3 in Leydig cells under LPS treatment. miR-93-5p inhibited PTEN expression and that over-expressed PTEN alleviated the effect of miR-93-5p in Leydig cells treated with LPS. LPS activated the MEG3/miR-93-5p/PTEN signalling pathway in Leydig cells. Conclusions This study revealed that MEG3 serves as a molecular sponge to absorb miR-93-5p, thus leading to elevation of PTEN expression in Leydig cells under LPS treatment, offering a theoretical basis on which to establish potential new treatment strategies for orchitis.

Hepatitis C virus‐associated indolent B‐cell lymphomas: A review on the role of the new direct antiviral agents therapy

2021 ◽  
Author(s):  
Cesare Mazzaro ◽  
Luigino Dal Maso ◽  
Marcella Visentini ◽  
Anna Ermacora ◽  
Pietro Andreone ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Antiviral Agents ◽  
B Cell Lymphomas ◽  
Direct Antiviral Agents

Role of PRAS40 in Akt and mTOR signaling in health and disease

2012 ◽  
Vol 302 (12) ◽  
pp. E1453-E1460 ◽  
Author(s):  
Claudia Wiza ◽  
Emmani B. M. Nascimento ◽  
D. Margriet Ouwens
Keyword(s):  
Mammalian Target Of Rapamycin ◽  
Mtor Signaling ◽  
Cellular Growth ◽  
S6 Kinase ◽  
Binding Partners ◽  
Health And Disease ◽  
Mtor Complex 1 ◽  
Mtor Activity

The proline-rich Akt substrate of 40 kDa (PRAS40) acts at the intersection of the Akt- and mammalian target of rapamycin (mTOR)-mediated signaling pathways. The protein kinase mTOR is the catalytic subunit of two distinct signaling complexes, mTOR complex 1 (mTORC1) and mTORC2, that link energy and nutrients to the regulation of cellular growth and energy metabolism. Activation of mTOR in response to nutrients and growth factors results in the phosphorylation of numerous substrates, including the phosphorylations of S6 kinase by mTORC1 and Akt by mTORC2. Alterations in Akt and mTOR activity have been linked to the progression of multiple diseases such as cancer and type 2 diabetes. Although PRAS40 was first reported as substrate for Akt, investigations toward mTOR-binding partners subsequently identified PRAS40 as both component and substrate of mTORC1. Phosphorylation of PRAS40 by Akt and by mTORC1 itself results in dissociation of PRAS40 from mTORC1 and may relieve an inhibitory constraint on mTORC1 activity. Adding to the complexity is that gene silencing studies indicate that PRAS40 is also necessary for the activity of the mTORC1 complex. This review summarizes the regulation and potential function(s) of PRAS40 in the complex Akt- and mTOR-signaling network in health and disease.

scholarly journals Lymphoma models for B cell activation and tolerance. X. Anti-mu-mediated growth arrest and apoptosis of murine B cell lymphomas is prevented by the stabilization of myc.

1994 ◽  
Vol 179 (1) ◽  
pp. 221-228 ◽  
Author(s):  
G Fischer ◽  
S C Kent ◽  
L Joseph ◽  
D R Green ◽  
D W Scott
Keyword(s):  
Growth Inhibition ◽  
B Cell ◽  
Antisense Oligonucleotides ◽  
Growth Regulation ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
B Cell Activation ◽  
Tgf Beta ◽  
B Cell Lymphomas

Treatment of the WEHI-2131 or CH31 B cell lymphomas with anti-mu or transforming growth factor (TGF)-beta leads to growth inhibition and subsequent cell death via apoptosis. Since anti-mu stimulates a transient increase in c-myc and c-fos transcription in these lymphomas, we examined the role of these proteins in growth regulation using antisense oligonucleotides. Herein, we demonstrate that antisense oligonucleotides for c-myc prevent both anti-mu- and TGF-beta-mediated growth inhibition in the CH31 and WEHI-231 B cell lymphomas, whereas antisense c-fos has no effect. Furthermore, antisense c-myc promotes the appearance of phosphorylated retinoblastoma protein in the presence of anti-mu and prevents the progression to apoptosis as measured by propidium iodide staining. Northern and Western analyses show that c-myc message and the levels of multiple myc proteins were maintained in the presence of antisense c-myc, results indicating that myc species are critical for the continuation of proliferation and the prevention of apoptosis. These data implicate c-myc in the negative signaling pathway of both TGF-beta and anti-mu.

Lymphocyte-predominant Hodgkin lymphoma: what is the optimal treatment?

Hematology ◽  
2013 ◽  
Vol 2013 (1) ◽  
pp. 406-413 ◽  
Author(s):  
Michelle Fanale
Keyword(s):  
B Cell ◽  
Hodgkin Lymphoma ◽  
Radiation Treatment ◽  
Early Stage ◽  
B Cell Lymphoma ◽  
B Cell Lymphomas ◽  
Early Stage Disease ◽  
Stage Disease ◽  
Relapsed Disease

AbstractNodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a unique diagnostic entity, with only ∼ 500 new cases in the United States per year with a similar infrequent incidence worldwide. NLPHL also has distinctive pathobiology and clinical characteristics compared with the more common classical Hodgkin lymphoma (cHL), including CD20 positivity of the pathognomic lymphocytic and histiocytic cells and an overall more indolent course with a higher likelihood of delayed relapses. Given the limited numbers of prospective NLPHL-focused trials, management algorithms historically have typically been centered on retrospective data with guidelines often adopted from cHL and indolent B-cell lymphoma treatment approaches. Key recent publications have delineated that NLPHL has a higher level of pathological overlap with cHL and the aggressive B-cell lymphomas than with indolent B-cell lymphomas. Over the past decade, there has been a series of NLPHL publications that evaluated the role of rituximab in the frontline and relapsed setting, described the relative incidence of transformation to aggressive B-cell lymphomas, weighed the benefit of addition of chemotherapy to radiation treatment for patients with early-stage disease, considered what should be the preferred chemotherapy regimen for advanced-stage disease, and even assessed the potential role of autologous stem cell transplantation for the management of relapsed disease. General themes within the consensus guidelines include the role for radiation treatment as a monotherapy for early-stage disease, the value of large B-cell lymphoma–directed regimens for transformed disease, the utility of rituximab for treatment of relapsed disease, and, in the pediatric setting, the role of surgical management alone for patients with early-stage disease.

Critical role of multidimensional flow cytometry in detecting occult leptomeningeal disease in newly diagnosed aggressive B-cell lymphomas

2008 ◽  
Vol 32 (8) ◽  
pp. 1196-1199 ◽  
Author(s):  
R. Di Noto ◽  
G. Scalia ◽  
G. Abate ◽  
M. Gorrese ◽  
C. Pascariello ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
B Cell ◽  
Critical Role ◽  
Leptomeningeal Disease ◽  
Newly Diagnosed ◽  
B Cell Lymphomas

A comparative evaluation of conventional and pretargeted radioimmunotherapy of CD20-expressing lymphoma xenografts

Blood ◽  
2001 ◽  
Vol 98 (8) ◽  
pp. 2535-2543 ◽  
Author(s):  
Oliver W. Press ◽  
Melissa Corcoran ◽  
Krishnan Subbiah ◽  
Don K. Hamlin ◽  
D. Scott Wilbur ◽  
...  
Keyword(s):  
B Cell ◽  
Treatment Approach ◽  
Great Promise ◽  
B Cell Lymphomas ◽  
Marked Contrast ◽  
Hematopoietic Stem ◽  
Normal Organ ◽  
New Treatment ◽  
Anti Cd20 ◽  
Cell Support

Abstract Radioimmunotherapy with anti-CD20 monoclonal antibodies is a promising new treatment approach for patients with relapsed B-cell lymphomas. However, the majority of patients treated with conventional radiolabeled anti-CD20 antibodies eventually have a relapse because the low tumor-to-blood and tumor-to–normal organ ratios of absorbed radioactivity limit the dose that can be safely administered without hematopoietic stem cell support. This study assessed the ability of a streptavidin-biotin “pretargeting” approach to improve the biodistribution of radioactivity in mice bearing Ramos lymphoma xenografts. A pretargeted streptavidin-conjugated anti-CD20 1F5 antibody was infused, followed 24 hours later by a biotinylated N-acetylgalactosamine–containing “clearing agent” and finally 3 hours later by 111In-labeled DOTA-biotin. Tumor-to-blood ratios were 3:1 or more with pretargeting, compared with 0.5:1 or less with conventional 111In-1F5. Tumor-to–normal organ ratios of absorbed radioactivity up to 56:1 were observed with pretargeting, but were 6:1 or less with conventional 111In-1F5. Therapy experiments demonstrated that 400 μCi (14.8 MBq) or more of conventional 90Y-1F5 was required to obtain major tumor responses, but this dose was associated with lethal toxicity in 100% of mice. In marked contrast, up to 800 μCi (29.6 MBq)90Y-DOTA-biotin could be safely administered by the pretargeting approach with only minor toxicity, and 89% of the mice were cured. These data suggest that anti-CD20 pretargeting shows great promise for improving current therapeutic options for B-cell lymphomas and warrants further preclinical and clinical testing.

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