Proteomic analysis of apoptosis initiation induced byall-trans retinoic acid in human acute promyelocytic leukemia cells

Abstract

The irreversible destiny of apoptosis in its early stage might play a critical role in the apoptosis of human acute promyelocytic leukemia (APL) cell line induced by all-trans retinoic acid (ATRA). To characterize protein alterations during the apoptosis-initiation phase and to understand the metabolic status at that time, we investigated the protein profiles in the apoptosis-initiation phase of APL cell line HL-60 by proteomic analysis. ATRA-withdrawal was conducted to demonstrate that there was committed initiation phase of apoptosis triggered by 10(-6) M ATRA at day 3. Only after that time point, ATRA-treated cells irreversibly went to apoptosis. Also at that time point, the positive regulators of apoptosis such as STAT3 increased at protein level, whereas negative regulators (Bcl-2 and p-STAT3) decreased. In addition, caspase-3 also increased after that time. Furthermore, comparative proteomic analysis was utilized to examine the protein expression profiles during the initiation stage of apoptosis. Our results showed 12 upregulated and 7 downregulated proteins experiencing twofold alteration, including key regulators of signal transduction such as G-proteins and nucleic receptors, proteins related with metabolism, oxidation and reduction, proteins associated with the nucleus and cytoskeleton-related proteins. Some of them could be positive modulators to trigger apoptosis, whereas others could contribute to intracellular defense against apoptosis induced by exogenous triggers. The results above suggest that there is a subtle balance between apoptosis and the intracellular defense against apoptosis. Once the balance is disturbed, cells would irreversibly initiate to undergo the execution of apoptosis.

Expression of S100A8 in leukemic cells predicts poor survival in de novo AML patients

“…The interest and importance of proteomics in the research of prognostic markers was revealed for AML, 13,14 clinical behavior predictions in adult acute lymphoblastic leukemia 15 and therapy-related proteome variations. 16 Finally, functional proteomic profiling confirmed that specific protein expression patterns correlate with outcome and prognosis, thus providing new molecular classifications useful for predicting the risk of AML patients at diagnosis. 17 In this context, we developed a surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF)-based protein profile of leukemic cells associated with tandem MS (MALDI-TOF/TOF and nanoLC MS/MS) to identify new, specific biomarkers of high-risk AML that are present at the time of diagnosis.…”

Rho GDP Dissociation Inhibitor Protects Cancer Cells against Drug-Induced Apoptosis

“…The results presented here show that the level of RhoGDI in cancer cells regulates the apoptotic response of the cells to these two chemotherapy agents as well as to staurosporine and suggest that RhoGDI overexpression gives cancer cells a survival mechanism against these antitumor chemotherapies. Consistent with this hypothesis, treatment of myeloid leukemia cells with agents that increase cell death in response to chemotherapy drugs (all-trans retinoic acid and the cyclin-dependent kinase inhibitor bohemine treatment) was associated with down-regulation of RhoGDI levels (26,27).…”

Reverse phase protein array: validation of a novel proteomic technology and utility for analysis of primary leukemia specimens and hematopoietic stem cells

“…Attempts at the proteomic characterization of leukemic cells have mainly used matrix-assisted laser desorption/ionization-time of flight analysis after two-dimensional gel electrophoresis. The available evidence is sparse but supports the importance of proteomic analysis of leukemias, e.g., for class distinction (4), target identification (5), apoptosis initiation (6), and stem cell analysis (7). However, the proteins isolated by these technologies need to be identified and characterized by other means, and a more comprehensive profiling could not be achieved due to the excessive requirements for material to study and for the time required to perform each analysis.…”