Na Qiao

• University of Texas MD Anderson Cancer Center

Myeloid azurophil granules provide a rich source of intracellular leukemia antigens. Cathepsin G (CG) is a serine protease that has higher expression in acute myeloid leukemia (AML) blasts in comparison to normal myeloid progenitors. Based on the unique biology of HLA-A*0201 (HLA-A2), in which presentation of leader sequence (LS)-derived peptides i...

Myeloid azurophil granules provide a rich source of intracellular leukemia antigens. Cathepsin G (CG) is a serine protease that has higher expression in acute myeloid leukemia (AML) blasts in comparison to normal myeloid progenitors. Based on the unique biology of HLA-A*0201 (HLA-A2), in which presentation of leader sequence (LS)-derived peptides i...

Estrogen receptor–positive (ER+) breast cancer is not considered immunogenic and, to date, has been proven resistant to immunotherapy. Endocrine therapy remains the cornerstone of treatment for ER+ breast cancers. However, constitutively activating mutations in the estrogen receptor alpha (ESR1) gene can emerge during treatment, rendering tumors re...

Introduction: Myeloid azurophil granules provide a rich source of intracellular leukemia antigens. Cathepsin G (CG) is a serine protease that has higher expression in AML blasts in comparison to normal myeloid progenitors. Based on the unique biology of HLA-A*0201 (HLA-A2), in which presentation of leader sequence (LS)-derived peptides is favored,...

NeuVax is a vaccine comprised of the HER2-derived MHC class I peptide E75 (nelipepimut-S, NPS) combined with GM-CSF. We completed a randomized trial of preoperative vaccination with NeuVax versus GM-CSF alone in patients with ductal carcinoma in situ (DCIS). The primary objective was to evaluate for NPS-specific cytotoxic T lymphocyte (CTL) respons...

Background: Immunotherapy is the standard of care for many solid tumor malignancies. However, due to a paucity of known tumor antigens in non-small cell lung cancer (NSCLC) and osteosarcoma (OS), identification of novel immunogenic antigens is needed. Our group has experience with neutrophil serine proteases (NSP) derived from the azurophilic granu...

Background Pembrolizumab, an antibody that blocks programmed cell death protein 1 (PD-1), has been FDA approved for several solid tumors and hematologic malignancies. Currently, pembrolizumab is under investigation for acute myeloid leukemia (AML) in combination with hypomethylating agents. It is established that AML is highly responsive to immunot...

Background: Peptide cancer vaccines may be most effective when used in earlier stage cancers or pre-cancers where systemic and tumor microenvironmental immune suppression are less profound. Nelipepimut-S (NPS) plus granulocyte-macrophage colony-stimulating factor (GM-CSF) is a vaccine comprised of a human leukocyte antigen (HLA) restricted peptide...

HER2-targeted therapy has not benefited patients with low levels of HER2 expression; however, combination therapy may be effective. Primary analysis of a phase IIb trial investigating the HER2-derived vaccine nelipepimut-S (NPS) did not benefit the intention-to-treat population, but subset analysis showed a benefit in triple-negative breast cancer...

Cytotoxic T lymphocyte (CTL)-based cancer immunotherapies have shown great promise for inducing clinical regressions by targeting tumor-associated antigens (TAA). To expand the TAA landscape of pancreatic ductal adenocarcinoma (PDAC), we performed tandem mass spectrometry analysis of HLA class I-bound peptides from 35 PDAC patient tumors. This iden...

Immunotherapy targeting leukemia-associated antigens has shown promising results. Because of the heterogeneity of leukemia, vaccines with a single peptide have elicited only a limited immune response. Targeting several peptides together elicited peptide-specific cytotoxic T lymphocytes (CTLs) in leukemia patients, and this was associated with clini...

3135 Background: Estrogen receptor (ER)-positive breast cancer is not considered immunogenic. Standard treatment is endocrine therapy to include aromatase inhibitors (AI). However, constitutively activating mutations in estrogen receptor alpha ( ESR1) emerge with treatment making tumors resistant to AI therapy. While these mutations represent a pat...

Purpose: Preclinical data provide evidence for synergism between HER2-targeted peptide vaccines and trastuzumab. The efficacy of this combination was evaluated in HER2 low-expressing breast cancer patients in the adjuvant setting. Experimental design: A phase IIb, multicenter, randomized, single-blinded, controlled trial enrolled disease-free pa...

Purpose: Inefficient homing of adoptively transferred cytotoxic T lymphocytes (CTLs) to tumors is a major limitation to the efficacy of adoptive cellular therapy (ACT) for cancer. However, through fucosylation, a process whereby fucosyltransferases (FT) add fucose groups to cell surface glycoproteins, this challenge may be overcome. Endogenously f...

Many aggressive hematologic malignancies are exquisitely responsive to immunotherapy. While allogeneic (allo) hematopoietic stem cell transplantation (SCT) is the prime example of anti-leukemia immunotherapy, it is highly toxic, limiting its application to patients with aggressive disease and a good performance status. Although targeting leukemia-a...

In this randomized phase Ib trial, we tested combining the E39 peptide vaccine with a vaccine created from E39’, an attenuated version of E39. Patients with breast or ovarian cancer, who were disease-free after standard of care therapy, were enrolled and randomized to one of three arms. Arm EE received six E39 inoculations; arm EE’ received three E...

Cathepsin G (CG) is a myeloid azurophil granule protease that is highly expressed by acute myeloid leukemia (AML) blasts and leukemia stem cells. We previously identified CG1 (FLLPTGAEA), a human leukocyte antigen-A2-restricted nonameric peptide derived from CG, as an immunogenic target in AML. In this report, we aimed to assess the level of CG exp...

Human leukocyte antigen (HLA)-A*0201 status of UPN2. UPN2 ALL was stained with anti-HLA-A*0201 antibody (clone BB7.2) and analyzed using flow cytometry. Data demonstrate UNP2 to be HLA-A2*0201 negative. The HLA-A*0201-positive cell line, T2, was used as a positive control.

PMN-associated cathepsin G (CG) is taken up by normal B cells. Flow cytometry detected intracellular CG in the B cell population from normal donor peripheral blood mononuclear cells (PBMC) that were cocultured with irradiated whole PMN at a ratio of 3:1 overnight. PBMC were surface stained with lineage antibodies, including CD3, CD14, CD16, and CD1...

Gating strategy used to determine uptake of cathepsin G (CG) by ALL cell lines. NALM6 cells were surface stained with antibodies including CD10 (BioLegend), CD16 (BioLegend), CD19 (BD), and CD38 (BioLegend). Cells were fixed, permeabilized and intracellularly stained with anti-CG antibody. B-ALL cells were differentiated based on light scatter char...

Raji-A2 cells take up exogenous cathepsin G (CG). Raji-A2 cells were cultured with purified CG (10 μg/mL) for 24 h. Western blot analysis shows uptake of CG by Raji-A2. Western blots demonstrate CG protein in whole-cell lysates from Raji-A2. Gels were loaded with 30 μg of protein. U937 cell line was used as a positive control. Actin was used as a l...

Gating strategy used to determine CG1-CTL frequency following expansion. Cytotoxic T lymphocytes (CTLs) were stained with CG1/human leukocyte antigen (HLA)-A*0201 tetramer in addition to CD3, CD8, lineage (lin) markers CD4, 14, 16, 19, and live/dead Ghost Violet stain. Frequencies of CG1-CTL (CG1/HLA-A*0201 tetramer+) is determined from live, lin−,...

Early phase clinical trials evaluating CD8+ T cell-eliciting, HER2-derived peptide vaccines administered to HER2-positive breast cancer patients in the adjuvant setting suggest synergy between the vaccines and trastuzumab, the monoclonal antibody targeting the HER2 protein. Among 60 patients enrolled on clinical trials evaluating the E75+GM-CSF and...

Neutrophil elastase (NE) can be rapidly taken up by tumor cells that lack endogenous NE expression, including breast cancer, which results in cross-presentation of PR1, an NE-derived HLA-A2-restricted peptide that is an immunotherapy target in hematological and solid tumor malignancies. The mechanism of NE uptake, however, remains unknown. Using th...

BACKGROUND FBP is overexpressed in 20-50% of breast(B) cancers(Ca) and roughly 90% of endometrial(E) and ovarian (Ov) Ca. E39 (FBP191-199, EIWTHSYKV)+GM-CSF is an HLA-A2 restricted FBP peptide vaccine, which has been shown to generate significant immunologic response(IR) in a phase I/IIa trial in E Ca and Ov Ca patients (pts). There is a risk of in...

Introduction: We have previously reported that breast cancer cells take up the inflammatory mediator neutrophil elastase (NE) from tumor-associated neutrophils (TANs). NE uptake leads to: 1) increased cleavage of cyclin E (CCNE) to its low molecular weight isoforms and generation of the CCNE-derived immunogenic epitope CCNE144-152, 2) cross-present...

Introduction: The purpose of this study was to identify the effect of trastuzumab on the uptake and presentation of HER2-derived peptides by dendritic cells (DCs). Clinical trials for HER2-derived peptide vaccines have shown improved outcomes for patients receiving a combination of vaccine and trastuzumab suggesting potential synergy between the tw...

Neutrophil elastase (NE) is an innate immune cell-derived inflammatory mediator that we have shown increases the presentation of tumor-associated peptide antigens in breast cancer. In this study, we extend these observations to show that NE uptake has a broad effect on enhancing antigen presentation by breast cancer cells. We show that NE increases...

Introduction Immunotherapy using cytotoxic T lymphocytes (CTL) has shown efficacy in the management of leukemia. However the efficacy of CTL, whether they are engineered and adoptively transferred or administered as part of allogeneic stem cell transplantation, must be balanced by their off-target toxicities, which at times can be lethal. Fucosylat...

Fucosylation is a process by which fucose sugar groups are added to cell surface receptors. This process is mediated by fucosyl transferases that attach terminal fucose groups to acceptor molecules on the cell surface. Fucosylation of cord blood stem cells and human regulatory T cells (Treg) were shown to enhance cord blood engraftment and Treg hom...

Introduction: Neutrophil elastase (NE) is an inflammatory mediator that is taken up by breast cancer cells. We have previously shown that NE uptake increases susceptibility to lysis by cytotoxic T lymphocytes (CTL) targeting the tumor antigens PR1 and cyclin E. We investigated whether NE uptake alters adaptive immunity by affecting MHC class I anti...

Early-phase trials targeting the T-cell inhibitory molecule programmed cell death ligand 1 (PD-L1) have shown clinical efficacy in cancer. This study was undertaken to determine whether PD-L1 is overexpressed in triple-negative breast cancer (TNBC) and to investigate the loss of PTEN as a mechanism of PD-L1 regulation. The Cancer Genome Atlas (TCGA...

Introduction: Several MHC class I HER2-derived peptides have been identified that elicit a peptide-specific, cytotoxic T lymphocyte (CTL) response. We have postulated that Trastuzumab (Tz) binding may protect or modulate enzymatic cleavage sites on HER2 normally accessible by proteasomes thereby altering the cleavage pattern and resulting peptide p...

PR1 is a HLA-A2-restricted peptide that has been targeted successfully in myeloid leukemia with immunotherapy. PR1 is derived from the neutrophil granule proteases proteinase 3 (P3) and neutrophil elastase (NE), which are both found in the tumor microenvironment. We recently showed that P3 and NE are taken up and cross-presented by normal and leuke...

There is little understanding of the impact of tumor-associated neutrophils (TAN) on adaptive immunity to tumors. In this study, we report the results of an investigation of the pathobiologic basis for the prognostic significance of neutrophil elastase, a serine protease found in neutrophil granules, in a model of cyclin E (CCNE)-overexpressing bre...

Cross-presentation is an important mechanism by which exogenous tumor antigens are presented to elicit immunity. Because neutrophil elastase (NE) and proteinase-3 (P3) expression is increased in myeloid leukemia, we investigated whether NE and P3 are cross-presented by dendritic cells (DC) and B cells, and whether the NE and P3 source determines im...

We have shown that the HLA-A2-restricted nonapeptide PR1 (VLQELNVTV) is a leukemia-associated peptide derived from P3 and NE. Furthermore, immunologic and clinical responses to PR1 peptide vaccination occur in patients with acute (AML), chronic (CML) myeloid leukemia and myelodysplastic syndrome. We have also shown that PR1 expression results from...

Introduction: High level of neutrophil elastase (NE) in tumor tissue from breast cancer (BrCa) patients is associated with poor metastasis-free survival. Modest endogenous expression of NE in some BrCa cell lines has also been observed. However, because the major source of NE is from azurophil granules of activated neutrophils, we hypothesized that...

2090 We have shown that cytotoxic T lymphocytes (CTL) with specificity for the cyclin E (CCNE) derived HLA-A2-restricted peptide CCNE144-152 (ILLDWLMEV) specifically lyse myeloid and lymphoid leukemia in proportion to CCNE overexpression. Full length (FL) CCNE is also overexpressed in most solid tumors, including breast cancer where it is a poor pr...

2089 The human leukocyte antigen (HLA)-A2 restricted nonapeptide PR1 (VLQELNVTV) was shown to be immunogenic in leukemia. A phase I/II clinical trial has been initiated with PR1 peptide vaccine and to date has demonstrated clinical efficacy, including complete remission and immunologic responses in patients with acute (AML) and chronic (CML) myeloi...

HER2/neu (HER2) and cyclin E are important prognostic indicators in breast cancer. Since both are involved in cell cycle regulation we investigated whether there was a direct interaction between the two. HER2 and cyclin E expression levels were determined in 395 breast cancer patients. Patients with HER2-overexpression and high levels of cyclin E h...

Figure 1 Effect of expression of full-length and low molecular weight (LMW) cyclin E on HER2. A) MCF-7 breast cancer cells stably transfected with FLAG-tagged constructs corresponding to the full-length (EL), the EL2 and EL3 LMW isoforms (T1), or the EL5 and EL6 LMW isoforms (T2) of cyclin E. Parental MCF-7 and cells transfected with vector backbon...

Figure 3 Alteration in proliferation and cell cycle profiles after trastuzumab treatment. A) MCF-7-HER-18 and SKBr3 cells were treated with trastuzumab and cell number determined at 72 hours using MTT assays. There was a dose-dependent decrease in the number of viable trastuzumab treated cells, suggesting that decreased HER2-mediated signaling caus...

Figure 2 Increase in apoptosis following HER2 downregulation using siRNA. Apoptosis was assessed using an annexin V assay after transfection with HER2 siRNA. Experiments were repeated in triplicate and the average percent increase in apoptosis for each of the three experiments was determined. Error bars represent the standard error of the mean.

Supplemental Table 1 HER2 downregulation using siRNA does not significantly effect cyclin E transcription. A) MCF-7-HER-18 and B) SKBr3 breast cancer cells were mock transfected, transfected with a random sequence siRNA, or transfected with HER2 siRNA. To determine the effect of HER2 downregulation on cyclin E transcription, quantitative reverse tr...

Doxorubicin is a genotoxic chemotherapy agent used in treatment of a wide variety of cancers. Significant clinical side effects, including cardiac toxicity and myelosuppression, severely limit the therapeutic index of this commonly used agent and methods which improve doxorubicin efficacy could benefit many patients. Because doxorubicin cytotoxicit...

The use of Gleevec in the treatment of leukemia has been widely accepted, although resistance to Gleevec is commonly observed. Gleevec represents a new direction in the development of target-focused chemotherapeutic agents in cancer. Gleevec inhibits the tyrosine kinase activity of Bcr-Abl, which is responsible for leukemic cell survival. We have p...

Thromboxane A(2) (TXA(2)) is an arachidonic acid metabolite involved in pathologies such as stroke, myocardial infarction, and atherosclerosis. Consequently, the design of TXA(2) receptor (TP) antagonists remains of great interest in cardiovascular medicine. The actions of TXA(2) are mediated by its specific G-protein coupled receptor of which two...

We have chemically synthesized several stable analogs of the naturally occurring hepoxilins, 12-LO products derived from arachidonic acid, which we found to have promising actions in a variety of test systems of disease. The analogs, PBTs, afford chemical and biological stability to the hepoxilin molecule. This article reviews some of our latest ob...

We demonstrate herein that daily administration of PBT-3 for 8 days to NU/NU mice bearing solid tumours derived from the s.c. administration of the leukemic cell line K562 results in inhibition of growth of the tumours in vivo, and this inhibition lasts for 60 days after stopping treatment with PBT-3 before recovery of tumour growth is re-establish...

Thromboxane A2 (TXA2) is a key mediator of platelet aggregation and smooth muscle contraction. Its action is mediated by its G protein-coupled receptor of which two isoforms, termed TPalpha and TPbeta, occur in humans. TXA2 has been implicated in pathologies such as cardiovascular diseases, pulmonary embolism, atherosclerosis, and asthma. This stud...

PBT-3 is one of a family of stable chemical analogs of the hepoxilins, products derived from arachidonic acid. We previously showed that PBT-3 caused apoptosis in the chronic myelogenous leukemia (CML) cell line K-562 in vitro (Anti-cancer Res 23: 3617-3622, 2003). It was as effective as Gleevec, a novel agent that blocks tyrosine kinase activity d...

The hepoxilin analog PBT-3 [10(S)-hydroxy-11,12-cyclopropyleicosa-5Z,8Z,14Z-trienoic acid methyl ester] was previously shown to inhibit the aggregation of human platelets and to antagonize the binding of the thromboxane receptor agonist I-BOP [[1S-[1alpha,2alpha (Z),3beta(1E,3S*),4alpha]]-7-[3-[3-hydroxy-4-(4-iodophenoxy)-1-butenyl]-7-oxabicyclo[2....

Leukemia is a heterogeneous disease characterized by malignant proliferation of cells of the hematopoietic system. The use of chemotherapeutic agents is still the mainstay of anti-leukemia therapy. Despite this, significant morbidity and mortality still occurs. We describe herein novel apoptotic effects of PBT-3, one of a family of stable analogs o...