Related Experiment Video
Updated: Mar 7, 2026
07:17
Author Spotlight: Advancing the Detection of Low-Frequency Mutations in Cancer Tissues
Published on: August 23, 2024
1.9K
mTOR activity in AIDS-related diffuse large B-cell lymphoma.
Sara H Browne1, Julio A Diaz-Perez1, Michael Preziosi1
1Division of Infectious Diseases, Department of Medicine, University of California, San Diego, La Jolla, CA, United States of America.
Plos One
|February 14, 2017
Summary
The mTOR pathway is active in most AIDS-related diffuse large B-cell lymphomas (AR-DLBCL). Phosphorylated 70 ribosomal S6 protein-kinase (p70S6K) is a key indicator of this activity and may predict response to mTOR inhibitors.
Area of Science:
- Oncology
- Immunology
- Molecular Biology
Background:
- Patients with HIV have an increased risk of non-Hodgkin lymphomas, even with HAART.
- Acquired immunodeficiency syndrome (AIDS)-related diffuse large B-cell lymphoma (AR-DLBCL) warrants further investigation into its molecular pathways.
- The mTOR pathway is a critical regulator of cell growth and proliferation.
Purpose of the Study:
- To investigate the activity of the mTOR pathway in AR-DLBCL.
- To examine the expression of phosphorylated 70 ribosomal S6 protein-kinase (p70S6K) and phosphorylated phosphatase and tensin homolog (pPTEN) in AR-DLBCL tissues.
- To correlate these markers with clinical and histopathologic features.
Main Methods:
- Immunohistochemistry was used to analyze p70S6K, pPTEN, and phosphorylated proline-rich Akt substrate of 40kDa (pPRAS40) expression in 126 AR-DLBCL tissue samples.
- Antibodies targeting specific epitopes of p70S6K (Ser235/236 and Ser240/244) were employed.
- Expression levels were assessed and correlated with clinical data.
Main Results:
- High levels of p70S6K were detected, particularly with the Ser240/244 epitope (86% positivity).
- p70S6K levels positively correlated with pPTEN expression (p = 0.016 and p = 0.007).
- pPRAS40 was highly expressed in 64.3% of cases, but showed no correlation with pPTEN or p70S6K.
Conclusions:
- The mTOR pathway is frequently active in AR-DLBCL.
- p70S6K expression, especially via the Ser240/244 epitope, serves as a reliable biomarker for mTOR pathway activation.
- p70S6K levels are independent of HIV viral load or CD4 counts, suggesting its utility in identifying patients who may benefit from mTOR inhibitors.
Related Concept Videos
03:03mTOR Signaling and Cancer Progression
5.0K
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
5.0K
01:22PI3K/mTOR/AKT Signaling Pathway
6.0K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
6.0K