ABSTRACT
Laryngeal squamous cell carcinoma (LSCC) is the most common type of head and neck squamous cell carcinoma (HNSCC) worldwide. Protein phosphatase 2A (PP2A) dysfunction has been widely reported in a broad range of malignancies due to its distinctive role in miscellaneous cellular processes. However, it is poorly understood whether aberrant alterations of PP2A are involved in the network of oncogenic events in LSCC. Here, we detected a panel of PP2A-associated proteins using western blot in both laryngeal squamous cell carcinoma tissues and paired adjacent normal tissues from patients (Data S1). We found that phospho-PP2A/C (Y307), α4, cancerous inhibitor of protein phosphatase 2A (CIP2A), Akt, ezrin, phospho-ezrin (T567), 14-3-3, and focal adhesion kinase (FAK) showed increased expression levels in carcinoma tissues relative to normal tissues, while phospho-Akt (T308) showed decreased levels. Our study, thus, provides a rationale for targeting PP2A to develop novel therapies and proposes a combination of interrelated biomarkers for the diagnostic evaluation and prognosis prediction in LSCC.
Subject(s)
Humans , Autoantigens/metabolism , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/metabolism , Case-Control Studies , Cytoskeletal Proteins/metabolism , Focal Adhesion Kinase 1/metabolism , Gene Expression Profiling , Gene Expression Regulation , Gene Expression Regulation, Neoplastic , Intracellular Signaling Peptides and Proteins/metabolism , Laryngeal Neoplasms/metabolism , Larynx/metabolism , Membrane Proteins/metabolism , Phosphorylation , Protein Phosphatase 2/metabolismABSTRACT
Sirtuin 1 (SIRT1) is a protein deacetylase, which regulates various physiological activities by deacetylating different protein substrates. An increasing number of studies have revealed critical roles of SIRT1 in different aspects of cancers including metabolism, proliferation, genomic instability, and chemotherapy resistance. Depending on the protein targets in a certain oncogenic context, SIRT1 may play a unique role in each individual blood cancer subtype. Our previous work showed that activation of SIRT1 in primitive leukemia cells of acute myeloid leukemia (AML) and chronic myelogenous leukemia (CML) promotes disease maintenance. On the other hand, an SIRT1 agonist was shown to disrupt maintenance of myelodysplastic syndrome (MDS) stem cells and holds promise as a potential therapeutic approach. Herein, we present a concise summary of the different functions of SIRT1 in hematologic malignancies.