Fuling Zhou

Involvement of Oxidative Stress in the Relapse of Acute Myeloid Leukemia

The aims of the present study were to determine the level of oxidative stress and the salient factors leading to the relapse of acute myeloid leukemia (AML). Oxidative stress-related parameters and the expressions of specific genes were monitored in 102 cases of AML during a pretreatment period from a primary status to a relapse status. In addition, age-matched healthy subjects were classified as controls. The activities of adenosine deaminase and xanthine oxidase were higher in the relapse condition, whereas those of glutathione peroxidase, monoamine oxidase, and superoxide dismutase, and the total antioxidant capacity (T-AOC) were lower in the primary condition and in controls. Of particular note, levels of advanced oxidation protein products, malondialdehyde, and 8-hydroxydeoxyguanosine were also significantly higher in relapse patients. Furthermore, real-time PCR with SYBR Green revealed that the expression levels of human thioredoxin (TRX) and indoleamine 2,3-dioxygenase were increased in relapse patients. Pearson correlation analysis revealed that the T-AOC was positively correlated with GSH but negatively correlated with 8-OHdG, TRX, and indoleamine 2,3-dioxygenase. Linear regression showed that a low T-AOC and up-regulated TRX expression were the independent factors correlated with relapse. A strong association between oxidative stress and the incidence of disease relapse was observed, which has potential prognosis implications. These results indicate that oxidative stress is a crucial feature of AML and probably affects the development and relapse of AML.

Stat3 Inhibitor Stattic Exhibits Potent Antitumor Activity and Induces Chemo- and Radio-Sensitivity in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignancy most common in East Asia, Africa and Alaska. Radiotherapy and cisplatin-based chemotherapy are the main treatment options. Unfortunately, disease response to concurrent chemoradiotherapy varies among patients with NPC, and many cases are resistant to cisplatin and radiotherapy. Signal transducer and activator of transcription 3 (Stat3) has been implicated in the development and progression of various solid tumors. In this study, we assessed the activation and expression of Stat3 in NPC cells. We found that Stat3 was activated and could be blocked by the small molecule inhibitor Stattic. The inhibition of Stat3 in NPC cells by Stattic decreased the expression of cyclin D1 in a dose- and time-dependent manner. Thus, Stattic was used to target Stat3 in NPC cell lines. We found that Stattic could inhibit cell viability and proliferation in NPC cells and significantly induced apoptosis. Additionally, Stat3 transfection attenuated, whereas Stat3 knockdown enhanced, the effects of Stattic upon cell viability inhibition and apoptosis induction. Furthermore, Stattic sensitized NPC cells to cisplatin and ionizing radiation (IR) by preventing cell proliferation and inducing apoptosis. Taken together, Stattic inhibit Stat3 and display antitumor effect in NPC, and enhanced chemosensitivity and radiosensitivity in NPC. Therefore, our findings provide the base for more rational approaches to treat NPC in the clinic.

Novel roles of reactive oxygen species in the pathogenesis of acute myeloid leukemia

It has become apparent that regulation of ROS is important in cell signaling and homeostasis. Accumulation of ROS triggers oxidative stress in various cell types and contributes to the development, progression, and persistence of cancer. Recent research has demonstrated that redox dysregulation caused by ROS promotes proliferation, differentiation, genomic, and epigenetic alterations; immune evasion; and survival in leukemic cells. ROS act as signaling molecules to regulate redox‐sensitive transcriptional factors, enzymes, oncogenes, and other downstream effectors. Thus, a thorough understanding the role of ROS as key mediators in leukemogenesis is likely to provide opportunities for improved pharmacological intervention. In this review, we summarize the recent findings that support a role for ROS in the pathogenesis of AML and outline innovative approaches in the implementation of redox therapies for myeloid malignancies.

Dickkopf-1 is a key regulator of myeloma bone disease: opportunities and challenges for therapeutic intervention.

Myeloma bone disease (MBD) is the most visible aspect of plasma cell myeloma (PCM), which is characterized by the displacement of hematopoiesis and the formation of osteolytic bone lesions. The secreted glycoprotein Dickkopf-1 (DKK1), an inhibitor of the Wnt signaling pathway, is broadly expressed in myeloma cells but highly restricted in normal tissues. DKK1 plays a critical role in several aspects of bone biology and actively participates in regulating MBD by inhibiting osteoblasts and by activating osteoclasts. Based on these findings, ongoing research has been targeting DKK1 to find novel therapeutic strategies for MBD, such as DKK1-neutralizing antibodies, proteasome inhibitors, and vaccines. All these strategies have produced encouraging clinical results and consequently, revealed the significance of DKK1 in MBD. This review discusses the recent advances in our understanding of the DKK1 pathway signaling and how DKK1 can be exploited in the therapeutic intervention of MBD.

Oxidative stress in depressive patients with gastric adenocarcinoma

Recent data from several studies suggest that oxidative stress is involved in the biochemical mechanisms that underlie neuropsychiatric disorders. The present study was designed to investigate oxidative stress status in depressive patients with gastric adenocarcinoma (GA) at TNM stage III. Oxidative stress, depression and expression of specific genes were monitored during a pretreatment period. Serum total antioxidant capacity, catalase, superoxide dismutase concentrations, and antisuperoxide anion capacity (A-ASC) were significantly decreased in depressive patients compared to control subjects, whereas serum malondialdehyde (MDA) levels were significantly increased. Importantly, the formation of 8-hydroxy-deoxyguanosine (8-OHdG) accumulated. Furthermore, SYBR Green real-time PCR revealed that the expression levels of human oxoguanine glycosylase 1 and APEX nuclease 1 (APEX1) were increased in depressive patients. Pearson correlation analysis revealed that depression was positively correlated with SAS, SCL-90, MDA, 8-OHdG and APEX1, but negatively correlated with A-ASC. Thus, this study confirms oxidative imbalance in depressive patients with GA, and oxidative stress may play a role in the onset and exacerbation of depression.

Serological identification and bioinformatics analysis of immunogenic antigens in multiple myeloma

Identifying appropriate tumor antigens is critical to the development of successful specific cancer immunotherapy. Serological analysis of tumor antigens by a recombinant cDNA expression library (SEREX) allows the systematic cloning of tumor antigens recognized by the spontaneous autoantibody repertoire of cancer patients. We applied SEREX to the cDNA expression library of cell line HMy2, which led to the isolation of six known characterized genes and 12 novel genes. Known genes, including ring finger protein 167, KLF10, TPT1, p02 protein, cDNA FLJ46859 fis, and DNMT1, were related to the development of different tumors. Bioinformatics was performed to predict 12 novel MMSA (multiple myeloma special antigen) genes. The prediction of tumor antigens provides potential targets for the immunotherapy of patients with multiple myeloma (MM) and help in the understanding of carcinogenesis. Crude lysate ELISA methodology indicated that the optical density value of MMSA-3 and MMSA-7 were significantly higher in MM patients than in healthy donors. Furthermore, SYBR Green real-time PCR showed that MMSA-1 presented with a high number of copy messages in MM. In summary, the antigens identified in this study may be potential candidates for diagnosis and targets for immunotherapy in MM.

Peptide-based immunotherapy for multiple myeloma: Current approaches

Multiple myeloma (MM) is a clonal B-cell malignancy with many fatal clinical sequelae. Despite extensive therapeutic approaches, cures remain rare exceptions. A recent promising area of investigation is the development of immunotherapeutic approaches that target and eliminate myeloma cells more selectively. Because of its potential to promote the destruction of cancerous cells via cytotoxic T-cell responses, peptide-based immunotherapy is one of these strategies to have attracted considerable attention. Furthermore, many studies were carried out to identify the best epitope peptides, the optimal vaccine formulation and schedule, and the preferable clinical situation for vaccination. Based on these results, various epitope peptides have been identified that may be selectively targeted by host immunity, and various approaches have been used to enhance the immune responses of peptides. This chapter focuses on reviewing previous immunotherapy trials, describing the current strategies for peptide-based immunotherapy, and discussing the achievable prospects in MM.

Serum peptidome based biomarkers searching for monitoring minimal residual disease in adult acute lymphocytic leukemia

BackgroundThe persistence of minimal residual disease (MRD) during therapy is the strongest adverse prognostic factor in acute lymphocytic leukemia (ALL). This study was to identify serum candidate peptides for monitoring MRD in adult ALL.ResultsA total of 33 peptides in the molecular weight range of 1000-10000 Da were detected using ClinProt system and statistically different between adult patients with ALL and healthy controls. Quick classifier (QC) algorithm was used to obtain a diagnostic model consisting of five peptides that could discriminate patients with ALL from controls with a high sensitivity (100%) and specificity (96.67%). The peptides in the QC model were identified as fibrinogen alpha chain (FGA), glutathione S-transferase P1 (GSTP1), isoform 1 of fibrinogen alpha chain precursor, platelet factor 4 (PF4) by high pressure/performance liquid chromatography mass spectrometry/mass spectrometry. Relative intensities of the five peptides were compared among ALL different groups for the potential importance of MRD evaluation in ALL. The peptides with increased relative intensities in newly diagnosed (ND) ALL patients were found to be decreased in their relative intensities after complete remission (CR) of adult ALL. When ALL patients were refractory & relapsed (RR), relative intensities of the peptides were elevated again. Peptides with decreased relative intensities in ND and RR ALL patients were found to be increased in their relative intensities when ALL patients achieved CR. The findings were validated by ELISA and western blot. Further linear regression analyses were performed to eliminate the influence of platelet and white blood cell counts on serum protein contents and indicated that there were no correlations between the contents of all four proteins (PF4, connective tissue active peptide III, FGA and GSTP1) and white blood cell or platelet counts in ALL different groups and healthy control.ConclusionsWe speculate the five peptides, FGA, isoform 1 of fibrinogen alpha chain precursor, GSTP1, PF4 and connective tissue active peptide III would be potential biomarkers for forecasting relapse, monitoring MRD and evaluating therapeutic response in adult ALL.

Jab1/Csn5-thioredoxin signaling in relapsed acute monocytic leukemia under oxidative stress

Purpose: High levels of ROS and ineffective antioxidant systems contribute to oxidative stress, which affects the function of hematopoietic cells in acute myeloid leukemia (AML); however, the mechanisms by which ROS lead to malignant transformation in relapsed AML-M5 are not completely understood. We hypothesized that alterations in intracellular ROS would trigger AML-M5 relapse by activating the intrinsic pathway. Experimental Design: We studied ROS levels and conducted c-Jun activation domain–binding protein-1 (JAB1/COPS5) and thioredoxin (TRX) gene expression analyses with blood samples obtained from 60 matched AML-M5 patients at diagnosis and relapse and conducted mechanism studies of Jab1′s regulation of Trx in leukemia cell lines. Results: Our data showed that increased production of ROS and a low capacity of antioxidant enzymes were characteristics of AML-M5, both at diagnosis and at relapse. Consistently, increased gene expression levels of TRX and JAB1/COPS5 were associated with low overall survival rates in patients with AML-M5. In addition, stimulating AML-M5 cells with low concentrations of hydrogen peroxide led to increased Jab1 and Trx expression. Consistently, transfection of ectopic Jab1 into leukemia cells increased Trx expression, whereas silencing of Jab1 in leukemia cells reduced Trx expression. Mechanistically, Jab1 interacted with Trx and stabilized Trx protein. Moreover, Jab1 transcriptionally regulated Trx. Furthermore, depletion of Jab1 inhibited leukemia cell growth both in vitro and in vivo. Conclusions: We identified a novel Jab1–Trx axis that is a key cellular process in the pathobiologic characteristics of AML-M5. Targeting the ROS/Jab1/Trx pathway could be beneficial in the treatment of AML-M5. Clin Cancer Res; 23(15); 4450–61. ©2017 AACR.

A novel multi‐epitope vaccine from MMSA‐1 and DKK1 for multiple myeloma immunotherapy

The identification of novel tumour‐associated antigens is urgently needed to improve the efficacy of immunotherapy for multiple myeloma (MM). In this study, we identified a membrane protein MMSA‐1 (multiple myeloma special antigen‐1) that was specifically expressed in MM and exhibited significantly positive correlation with MM. We then identified HLA‐A*0201‐restricted MMSA‐1 epitopes and tested their cytotoxic T lymphocyte (CTL) response. The MMSA‐1 epitope SLSLLTIYV vaccine was shown to induce an obvious CTL response in vitro. To improve the immunotherapy, we constructed a multi‐epitope peptide vaccine by combining epitopes derived from MMSA‐1 and Dickkopf‐1 (DKK1). The effector T cells induced by multi‐epitope peptide vaccine‐loaded dendritic cells lysed U266 cells more effectively than MMSA‐1/DKK1 single‐epitope vaccine. In myeloma‐bearing severe combined immunodeficient mice, the multi‐epitope vaccine improved the survival rate significantly compared with single‐epitope vaccine. Consistently, multi‐epitope vaccine decreased the tumour volume greatly and alleviated bone destruction. The frequencies of CD4+ and CD8+ T cells was significantly increased in mouse blood induced by the multi‐epitope vaccine, indicating that it inhibits myeloma growth by changing T cell subsets and alleviating immune paralysis. This study identified a novel peptide from MMSA‐1 and the multi‐epitope vaccine will be used to establish appropriate individualized therapy for MM.