Nonhematopoietic Tumors Research Articles

Intramedullary osteosarcoma of the mandible: a clinicoradiologic perspective.

Osteosarcoma is a non-hematopoietic primary malignant tumor of bone or mesenchymal tissue. Although osteosarcoma is not a common malignant bone tumor, accounting for approximately 20% of sarcomas, tumor of the jaw bone is uncommon, representing only about 4% of osteosarcomas of long bones. We report a case of a 72-year-old female with a swelling on the left side of the mandible and intra-oral swelling on the floor of the mouth. Conventional radiograph and advanced imaging modalities such as computed tomography and magnetic resonance imaging revealed an intramedullary osteosarcoma of the mandible. This report highlights importance of imaging modalities in the diagnosis of malignant tumors of the jaws.

CD43 Promotes Cells Transformation by Preventing Merlin-Mediated Contact Inhibition of Growth

In normal tissues, strict control of tissue size is achieved by regulating cell numbers. The mechanism that controls total cell number is known as contact inhibition of growth and it depends on the NF2/Merlin pathway. Negative regulation of this pathway by deleterious mutations or by oncogenes results in cell transformation and tumor progression. Here we provide evidence that the CD43 sialomucin cooperates with oncogenic signals to promote cell transformation by abrogating the contact inhibition of growth through a molecular mechanism that involves AKT-dependent Merlin phosphorylation and degradation. Accordingly, inhibition of endogenous CD43 expression by RNA interference in lung, cervix and colon human cancer cells impaired tumor growth in vivo. These data underscore a previously unidentified role for CD43 in non-hematopoietic tumor progression.

SWR/J mice are susceptible to alkylator-induced myeloid leukemia

SWR/J mice are susceptible to alkylator-induced myeloid leukemia

Rearrangement and expression of the immunoglobulin μ-chain gene in human myeloid cells

Immunoglobulin (Ig), a characteristic marker of B cells, has been reported to be expressed in epithelial cells, with a suggested role in their growth and survival. We have previously reported that IgG heavy chain is expressed in acute myeloid leukemia (AML), but not in the monocytes or neutrophils from patients with non-hematopoietic neoplasms or healthy controls. In the present study, we assessed IgM heavy chain expression and repertoire in human myeloid cells. We detected VHμDJHμ rearrangement and expression in 7/7 AML cell lines, 7/14 primary myeloblasts from AML patients, and interestingly, 8/20 monocytes and 3/20 neutrophils from patients with non-hematopoietic neoplasms and healthy individuals. We also found evidence of somatic hypermutation of the variable (V) gene segments in AML-derived IgM gene rearrangements but not in IgM from monocytes or neutrophils from patients with non-hematopoietic neoplasms and healthy individuals. Furthermore, IgM VHμDJHμ gene rearrangements in AML cell lines, primary myeloblasts, and monocytes and neutrophils from patients with non-hematopoietic neoplasms showed a restricted V usage and repertoire, whereas the VHμDJHμ gene rearrangements in monocytes and neutrophils from healthy individuals displayed more diversity. Anti-human IgM inhibited cell proliferation, but did not induce apoptosis in AML cell lines. Our findings suggest that AML-derived IgM might be a novel AML-related molecule that is involved in leukemogenesis and AML progression and might serve as a useful molecular marker for designing targeted therapy and monitoring minimal residual disease.

Epo Receptors Are Not Detectable in Primary Human Tumor Tissue Samples

Erythropoietin (Epo) is a cytokine that binds and activates an Epo receptor (EpoR) expressed on the surface of erythroid progenitor cells to promote erythropoiesis. While early studies suggested EpoR transcripts were expressed exclusively in the erythroid compartment, low-level EpoR transcripts were detected in nonhematopoietic tissues and tumor cell lines using sensitive RT-PCR methods. However due to the widespread use of nonspecific anti-EpoR antibodies there are conflicting data on EpoR protein expression. In tumor cell lines and normal human tissues examined with a specific and sensitive monoclonal antibody to human EpoR (A82), little/no EpoR protein was detected and it was not functional. In contrast, EpoR protein was reportedly detectable in a breast tumor cell line (MCF-7) and breast cancer tissues with an anti-EpoR polyclonal antibody (M-20), and functional responses to rHuEpo were reported with MCF-7 cells. In another study, a functional response was reported with the lung tumor cell line (NCI-H838) at physiological levels of rHuEpo. However, the specificity of M-20 is in question and the absence of appropriate negative controls raise questions about possible false-positive effects. Here we show that with A82, no EpoR protein was detectable in normal human and matching cancer tissues from breast, lung, colon, ovary and skin with little/no EpoR in MCF-7 and most other breast and lung tumor cell lines. We show further that M-20 provides false positive staining with tissues and it binds to a non-EpoR protein that migrates at the same size as EpoR with MCF-7 lysates. EpoR protein was detectable with NCI-H838 cells, but no rHuEpo-induced phosphorylation of AKT, STAT3, pS6RP or STAT5 was observed suggesting the EpoR was not functional. Taken together these results raise questions about the hypothesis that most tumors express high levels of functional EpoR protein.

Abstract 1451: Microfluidic-based unbiased enrichment (negative selection) of circulating non-hematopoietic tumor cells directly from whole blood without centrifugation.

Abstract The enumeration and analysis of circulating non-hematopoietic tumor cells (CTCs) is of increasing interest for monitoring disease progression or response to treatment, specifically as a companion diagnostic for new anti-cancer drugs, and for research into the mechanisms of disease progression and metastases. Ideally, CTCs would be enriched from very small samples, with minimal handling, high recovery, and no requirement for the expression of specific surface markers. Two technologies have been combined to meet these requirements. Hematopoietic white blood cells (WBCs) in whole blood were first cross-linked to magnetic particles using EasySep™ anti-CD45 TAC. The sample was diluted and placed in a magnet for 30 min.; an outlet in the bottom of the sample tube was then opened and the sample flowed by gravity into a microfluidic chamber containing a high-precision micro-slit membrane. Red blood cells (RBCs) flowed through the microfluidic chamber, while larger cells such as CTCs were retained in the chamber. The cells in the chamber were washed with PBS and then identified by staining with Hoechst [nuclear], anti-cytokeratin antibodies [epithelial cells], and anti-CD45 antibodies [hematopoietic cells]. CTCs were defined as Hoechst+, cytokeratin+ and CD45-. The recovery of MCF-7 breast adenocarcinoma cells spiked into normal whole blood, at 10, 30, 50, or 100 cells / 2 mL blood was 95 ± 23% (7 ± 1, n=3 for 10 cells; 24 ± 3, n=3 for 30 cells; 57 ± 3, n=3 for 50 cells; 113 ± 27, n=3 for 100 cells) and the log depletion of WBCs exceeded 2.3. The recovery of H1975 lung adenocarcinoma cells spiked into normal whole blood, at 10, 30, 50, or 100 cells / 2 mL blood was 93 ± 8% (9 ± 1, n=3 for 10 cells; 28 ± 3, n=3 for 30 cells; 48 ± 6, n=3 for 50 cells; 94 ± 2, n=3 for 100 cells), and the log depletion of WBCs exceeded 2.14. 13 patient samples [10 NSCLC and 3 CRC] were processed with this method and CTCs were detected in every sample. The number of CTC detected from 2 mL of blood ranged from 1 to 51. WBC log depletion ranged from 2.01 to 2.79. No RBCs were observed on the membrane of the microfluidic chamber. The entire process requires ∼ 60 minutes and could easily be automated. RBC depletion is essentially complete without the use of centrifugation or chemicals which may be deleterious to CTCs. The minimal sample handling permits high recovery of desired cells, allowing the detection of CTCs in much smaller samples than are currently used for clinical evaluation. CTCs are enriched without bias as to their surface antigen expression, and are not labeled with antibodies prior to detection. CTCs can be stained and visualized directly on the microfluidic chip. This unbiased enrichment approach could be used to assess the mutation status of CTC in real time. Citation Format: Carrie E. Peters, Hamizah Ahmad, Drew Kellerman, Bhuvanendran Nair Gourikutty Sajay, Chang Chia-Pin, Wong Chee Chung, Abdur Rub Abdur Rahman, Karina L. McQueen, Terry E. Thomas. Microfluidic-based unbiased enrichment (negative selection) of circulating non-hematopoietic tumor cells directly from whole blood without centrifugation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1451. doi:10.1158/1538-7445.AM2013-1451

Contribution of Multiparameter Flow Cytometry Immunophenotyping to the Diagnostic Screening and Classification of Pediatric Cancer

Pediatric cancer is a relatively rare and heterogeneous group of hematological and non-hematological malignancies which require multiple procedures for its diagnostic screening and classification. Until now, flow cytometry (FC) has not been systematically applied to the diagnostic work-up of such malignancies, particularly for solid tumors. Here we evaluated a FC panel of markers for the diagnostic screening of pediatric cancer and further classification of pediatric solid tumors. The proposed strategy aims at the differential diagnosis between tumoral vs. reactive samples, and hematological vs. non-hematological malignancies, and the subclassification of solid tumors. In total, 52 samples from 40 patients suspicious of containing tumor cells were analyzed by FC in parallel to conventional diagnostic procedures. The overall concordance rate between both approaches was of 96% (50/52 diagnostic samples), with 100% agreement for all reactive/inflammatory and non-infiltrated samples as well as for those corresponding to solid tumors (n = 35), with only two false negative cases diagnosed with Hodgkin lymphoma and anaplastic lymphoma, respectively. Moreover, clear discrimination between samples infiltrated by hematopoietic vs. non-hematopoietic tumor cells was systematically achieved. Distinct subtypes of solid tumors showed different protein expression profiles, allowing for the differential diagnosis of neuroblastoma (CD56hi/GD2+/CD81hi), primitive neuroectodermal tumors (CD271hi/CD99+), Wilms tumors (>1 cell population), rhabdomyosarcoma (nuMYOD1+/numyogenin+), carcinomas (CD45−/EpCAM+), germ cell tumors (CD56+/CD45−/NG2+/CD10+) and eventually also hemangiopericytomas (CD45−/CD34+). In summary, our results show that multiparameter FC provides fast and useful complementary data to routine histopathology for the diagnostic screening and classification of pediatric cancer.

A phase I study of oxaliplatin and doxorubicin in pediatric patients with relapsed or refractory extracranial non‐hematopoietic solid tumors

The combination of a platinum agent and anthracycline has shown activity in pediatric solid tumors. This trial evaluated the maximum tolerated dose (MTD) and dose limiting toxicities (DLT) of oxaliplatin combined with doxorubicin in pediatric patients with recurrent solid tumors. Oxaliplatin was administered on day 1 and Doxorubicin on days 1-3 of each 21 day course. The study utilized a standard 3 + 3 dose escalation design. Three dose levels were evaluated: (1) oxaliplatin 105 mg/m(2) and doxorubicin 20 mg/m(2); (2) oxaliplatin 130 mg/m(2) and doxorubicin 20 mg/m(2); and (3) oxaliplatin 130 mg/m(2) and doxorubicin 25 mg/m(2). Dexrazoxane was administered at 10 times the doxorubicin dose prior to doxorubicin infusion. Seventeen patients were enrolled. Dose level 1 was the determined MTD. Grade 2 cardiac DLT was seen in one of six patients on dose level 1, grade 4 thrombocytopenia in two of five patients on dose level 2, and one each of grade 2 cardiac and grade 4 thrombocytopenia in five patients on dose level 3. Cardiac DLT was only noted in patients with prior exposure to both anthracycline and chest radiation. No grade 3 or 4 neurotoxicity or mucositis was seen. Objective responses were noted in two patients with neuroblastoma and one each of mixed germ cell tumor, thymic neuroendocrine carcinoma, and nasopharyngeal carcinoma. Oxaliplatin 105 mg/m(2) on day 1 combined with doxorubicin 20 mg/m(2) days 1-3 was the MTD. This combination shows sufficient activity to justify further studies in select pediatric tumors.

Somatic mutation of IL7R exon 6 in acute leukemias and solid cancers

Inframe insertion and deletion/insertion (delins) mutations of the IL7R gene in exon 6 have recently been reported in childhood T-cell acute lymphoblastic leukemia (T-ALL). The recurrent nature of the IL7R mutations in the same region strongly suggests that the IL7R mutations may play an important role in the pathogenesis of childhood T-ALL. The aim of this study was to address whether IL7R exon 6 mutation occurs in other human tumors besides childhood T-ALL. For this, we analyzed 1792 tumor tissues from various origins, including 432 hematologic and 1360 nonhematopoietic tumors by single-strand conformation polymorphism analysis to detect the exon 6 mutations. Overall, we found 10 IL7R exon 6 mutations in seven hematologic malignancies (three childhood T-ALL [12%], one adult T-ALL [7%], two childhood precursor B-cell acute lymphoblastic leukemia (B-ALL) [2%] and one adult acute myelogenous leukemia (AML) [1%]) and three nonhematopoietic malignancies (one lung cancer [0.6%] and two colorectal cancer [0.5%]), but none in other tumors. IL7R mutations detected in hematologic tumors were exclusively inframe insertion and delins mutations, whereas those detected in non-hematologic tumors were missense and frameshift mutations. Our data indicate that IL7R exon 6 inframe mutations occur not only in childhood T-ALL but also other acute leukemias at slightly lower frequencies. Our data suggest that the IL7R mutations may contribute to the development of diverse types of acute leukemias, and that possible therapies targeting the IL7R exon 6 mutation should include not only childhood T-ALL but also T-ALL, childhood precursor B-ALL, and adult AML.

The antioxidant tempol reduces carcinogenesis and enhances survival in mice when administered after nonlethal total body radiation.

There is significant interest in the development of agents that can ameliorate radiation damage after exposure to radiation has occurred. Here we report that chronic supplementation of the antioxidant Tempol in the diet of mice can reduce body weight without toxicity, decrease cancer, and extend survival when administered after nonlethal total body radiation (TBI). These effects were apparent in two different strains of mice (C3H, CBA) exposed to TBI (3 Gy). Notably, delaying administration of the Tempol diet one month after TBI could also enhance survival. Tempol reduced the incidence of hematopoietic neoplasms (lymphomas) in both strains, whereas both the onset and incidence of nonhematopoietic neoplasms were reduced in CBA mice. These results encourage further study of Tempol as a chemopreventive, to reduce the incidence of radiation-induced second malignancies after a course of definitive radiation therapy. Tempol may also find applications to reduce the risk of cancers in populations exposed to nonlethal radiation due to nuclear accidents or terrorist attacks.

The protooncogene Vav1 regulates murine leukemia virus-induced T-cell leukemogenesis

Vav1 is expressed exclusively in hematopoietic cells and is required for T cell development and activation. Vav1-deficient mice show thymic hypocellularity due to a partial block during thymocyte development at the DN3 stage and between the double positive (DP) and single positive (SP) transition. Vav1 has been shown to play a significant role in several non-hematopoietic tumors but its role in leukemogenesis is unknown. To address this question, we investigated the role of Vav1 in retrovirus-induced T cell leukemogenesis. Infection of Vav1-deficient mice with the Moloney strain of murine leukemia virus (M-MuLV) significantly affected tumor phenotype without modulating tumor incidence or latency. M-MuLV-infected Vav1-deficient mice showed reduced splenomegaly, higher hematocrit levels and hypertrophic thymi. Notably, Vav1-deficient mice with M-MuLV leukemias presented with markedly lower TCRβ/CD3 levels, indicating that transformation occurred at an earlier stage of T cell development than in WT mice. Thus, impaired T cell development modulates the outcome of retrovirus-induced T cell leukemias, demonstrating a link between T cell development and T cell leukemogenesis.

Complementary methods provide evidence for the expression of CXCR7 on human B cells

PTMs of extracellular domains of membrane proteins can influence antibody binding and give rise to ambivalent results. Best proof of protein expression is the use of complementary methods to provide unequivocal evidence. CXCR7, a member of the atypical chemokine receptor family, mainly functions as scavenger for the chemokines CXCL12 and CXCL11. The expression of CXCR7 on nonhematopoietic cells and neoplasms is widely accepted, however, its expression on leukocytes was recently challenged. To solve the dissent, we thoroughly analyzed the expression of CXCR7 on human B cells. We validated the efficiency of different epitope-specific monoclonal antibodies to detect CXCR7 on transfected cells and primary human B cells. The specificity of the used antibodies was further confirmed by an experimentally independent double labeling approach. Examination of CXCR7-dependent scavenging of fluorescent-labeled CXCL12 revealed functional expression of the receptor on human B cells. Moreover, real-time PCR analysis of CXCR7 mRNA showed the presence of transcripts in human leukocytes. Finally, two CXCR7-specific peptides were identified by MS in immunoprecipitates from primary human B cells. Thus, we present a strategy based on combined proteomic and functional approaches that can be used to solve dissents on protein expression, i.e. demonstrating the expression of CXCR7 on human leukocytes.

Concurrent CD5-negative small lymphocytic lymphoma (SLL) and CD5-positive metastatic carcinoma of unknown primary in a lymph node biopsy

CD5 expression is considered a key marker for the diagnosis of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We report an unusual case of CD5-negative (CD5−) SLL with a concurrent CD5-positive (CD5+) adenocarcinoma of unknown primary involving the same lymph node. An 83-year-old woman with a history of CD5− B cell lymphoma diagnosed on a core biopsy of a cervical lymph node presented with jaundice and was found to have a 2.5-cm pancreatic mass. A fine needle aspiration of the mass revealed a CD5− monotypic B cell population. A subsequent excisional biopsy of a cervical lymph node showed morphologic findings typical for SLL, including the presence of multiple proliferation centers. However, the neoplastic lymphocytes were negative for CD5 by both flow cytometric analysis and immunohistochemistry. Interestingly, multifocal metastatic adenocarcinoma was identified and was positive for CD5. Lack of CD5 expression often leads to the exclusion of CLL/SLL, particularly in small biopsy samples. However, rare cases of CD5− CLL/SLL have been reported. In addition, CD5 is not an exclusive marker for lymphoid cells; its expression has been observed in several non-hematopoietic neoplasms. This report briefly reviewed and discussed CD5− CLL/SLL and CD5+ carcinoma reported in the literature.

Abstract 2375: Rapid unbiased enrichment (negative selection) of circulating non-hematopoietic tumor cells directly from whole blood

Abstract There is increasing interest in analyzing circulating non-hematopoietic tumor cells (CTC) in peripheral blood to evaluate disease progression or response to treatment; however, CTC enrichment is required prior to most analytic procedures. The ideal enrichment method would be rapid, permit a high recovery of viable CTC, and would be independent of the expression of specific epithelial cell surface markers, since CTCs in the peripheral blood may be undergoing EMT (epithelial mesenchymal transition) and may not express epithelial markers. RosetteSep™ CD45 depletion of hematopoietic cells directly from whole blood meets these criteria. However, RosetteSep™ enrichment of CTC involves density gradient centrifugation, which entails careful layering of the sample over the density gradient medium and careful pipetting to remove the enriched cells after centrifugation. Centrifugation must be performed with the brake off to avoid disturbing the enriched cell layer, further lengthening the process. SepMate™, a centrifugation tube with a specialized insert, was developed to minimize mixing of the sample with the density gradient medium, thus allowing rapid layering of the sample on the density gradient medium and easy pouring off of the enriched cells after centrifugation. We compared CTC enrichment using RosetteSep™ and the standard tubes and protocol with RosetteSep™ using SepMate™ tubes and reduced cocktail incubation and spin times on 5 donor whole blood samples seeded with ∼1% CAMA cells. Purity of viable (PI negative) CTC obtained with SepMate™ with RosetteSep™ was 85 ± 7%; purity of CTC obtained with RosetteSep™ alone was 91 ± 5% (no significant difference, paired t test, p=0.050). Purity of CTC obtained with density gradient centrifugation only (no RosetteSep™), either with or without SepMate™, was 4 ± 2%. There was no significant difference in the recovery of enriched CTC under any of the conditions tested (RosetteSep™ ± SepMate™, SepMate™ alone, density gradient separation alone, Tukey-Kramer test, p>0.05). CTC enrichment was accomplished in <40 min using SepMate™ with RosetteSep™. Simplifying the layering and layer removal step makes the entire process easily scalable to processing multiple samples simultaneously. Utilizing this method, CTCs can be enriched directly from whole blood without bias regarding their surface antigen expression. Large samples can be rapidly volume-reduced in preparation for detailed examination in a microfluidic device. Finally, enriched CTC are not labeled with antibodies or beads; there is nothing to interfere with subsequent further enrichment, culture, or evaluation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2375. doi:1538-7445.AM2012-2375

CRKL plays a pivotal role in tumorigenesis of head and neck squamous cell carcinoma through the regulation of cell adhesion

The signaling adapter protein CRK is an indispensable molecule involved in regulating the malignant potential of human cancers. CRK-like (CRKL) is a hematopoietic cell-dominant homologue of CRK that is reported to be phosphorylated by BCR–ABL tyrosine kinase in chronic myelogenous leukemia patients, but its biological function in non-hematopoietic tumors remains unclear. In this study, we explored the tumorigenic role of CRKL in head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. Immunoprecipitation analysis of HNSCC cell line, HSC-3 cells, showed that the dominant binding partner for C3G was CRKL, not CRK. To clarify the molecular function of CRKL, we established lentiviral shRNA-mediated CRKL-knockdown HNSCC cell lines. In CRKL-knockdown HSC-3 and HSC-4 cells, cell growth and motility were diminished compared to control cells. Cell adhesion assays showed that cell attachment onto both fibronectin- and collagen-coated dishes was significantly suppressed in CRKL-knockdown HSC-3 cells, while no significant change was observed for poly-l-lysine-coated dishes. Immunofluorescence staining revealed that focal adhesion was reduced in CRKL-knockdown HSC-3 cells. With a pulldown assay, CRKL-knockdown HSC-3 cells showed decreased amounts of active Rap1 compared to control cells. Moreover, in an in vivo assay, tumor formation of CRKL-knockdown HSC-3 cells in nude mice was significantly abrogated. Our results indicate that CRKL regulates HNSCC-cell growth, motility, and integrin-dependent cell adhesion, suggesting that CRKL plays a principal role in HNSCC tumorigenicity.

Canine non-hematopoietic gastric neoplasia

Aim of this study was to investigate epidemiologic and diagnostic characteristics of canine non-hematopoietic gastric neoplasia and to evaluate the surgical outcome of selected cases. Patient data of dogs with histologically confirmed non-hematopoietic gastric tumors were reviewed and dogs with surgical intervention were followed up. 38 dogs were included into the evaluation. Histopathologic diagnoses comprised carcinoma/adenocarcinoma (n=33), gastrointestinal stromal tumor (GIST) (n=4), and leiomyoma (n=1). Patients' median age was 10 years, median weight was 20 kg and the male:female ratio was 1.4:1. The breeds represented by most individuals were Chow Chow, Collie, Hovawart and mixed-breed. Most frequent presenting complaint was vomiting. Only a low proportion of dogs were presented with anemia, thrombocytopenia or hypoproteinemia. In 58% of cases, ultrasonographic examination led to findings that were considered compatible with gastric neoplasia. Gastric wall thickening and loss of layering were the most common sonographic findings. Most frequent endoscopic findings were mucosal thickening and reddening; ulcerations were infrequent. Computed tomography findings were compatible with gastric neoplasia in two cases in which CT was performed. Intra-operative cytology results showed accordance with histologic diagnoses in 88% of cases. Five dogs with different underlying pathology and variable disease extension underwent surgical tumor resection. In one patient, recurrence was diagnosed after 104 days. Survival times of these dogs ranged between 7 and 2326 days. Ultrasonography and, in selected cases, computed tomography aided in the diagnosis of gastric neoplasia. Intra-operative cytology possessed diagnostic value. In cases in which surgical resection was attempted, survival times varied markedly likely due to variable disease extension and underlying pathology (e.g. adenocarcinoma versus leiomyoma).

Granulocyte colony-stimulating factor and IL-6 producing carcinosarcoma of the esophagus manifesting as leukocytosis and pyrexia: a case report

Some patients with nonhematopoietic tumors show leukocytosis and pyrexia without overt inflammation. This report describes the case of a 47-year-old Japanese man who complained of persistent fever. Hematological examination showed marked leukocytosis with neutrophilia and elevation of C-reactive protein (CRP). Esophagogastroduodenoscopy demonstrated a polypoid tumor (5 cm in length) in the thoracic esophagus, which was suggested to cause high fever. After subtotal esophagectomy, leukocyte count and CRP level rapidly decreased and the high fever disappeared. Histological examination revealed a carcinosarcoma with four components: squamous cell carcinoma (SCC), basaloid carcinoma, spindle/pleomorphic cell sarcoma, and osteosarcoma. Immunohistochemically, the spindle/pleomorphic cells were positive for granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6). The patient was alive without recurrence 16 months after surgery.

Tumor suppressor p53 down-regulates expression of human leukocyte marker CD43 in non-hematopoietic tumor cells

CD43 (leukosialin, sialophorin), a cell surface protein on most hematopoietic cells, is an important regulator of immune cell function and is involved in regulation of cell adhesion and proliferation. Aberrant expression of CD43 is a common event observed in human tumors of non-hematopoietic origin suggesting a role in tumor development. We have previously shown that overexpression of CD43 causes activation of the ARF-p53 tumor-suppressor pathway and results in cell death. In a non-functional ARF-p53 background, the cells overexpressing CD43 display an increased cell growth rate due to higher survival. Here we show that p53 specifically downregulates the expression of CD43 at the protein and mRNA level. Transactivating properties of p53 are necessary to affect the expression of exogenous CD43. The downregulation of CD43 mRNA is caused by p53-dependent transrepression, at least in part, via a histone deacetylation mechanism. These studies establish that under certain conditions there exists a negative feedback loop between p53 and CD43: CD43-dependent signaling activates p53, which in turn downregulates the expression of CD43.

Cost-Effectiveness of Universal Hepatitis B Virus Screening in Patients Beginning Chemotherapy for Solid Tumors

Universal screening for chronic hepatitis B virus (HBV) infection before chemotherapy has been recommended. We evaluated the cost-effectiveness of HBV screening before chemotherapy given for nonhematopoietic solid tumors (STs). A decision-analytic model was used to compare the cost-effectiveness of universal screening conducted per professional guidelines versus no screening in hypothetical patient cohorts beginning adjuvant chemotherapy for early breast cancer or palliative chemotherapy for advanced non-small-cell lung cancer. Survival times were extrapolated using Markov models. Probabilities were derived from published studies and costs estimated from the perspective of the Australian health care system. One-way and probabilistic sensitivity analyses were performed, including with the application of an alternative HBV screening strategy. Using an incremental cost-effectiveness ratio threshold of $50,000 (Australian dollars) per life-year (LY) saved, universal HBV screening was not cost-effective for adjuvant patients ($88,224/LY, 13% probability of being cost-effective), palliative patients ($1,344,251/LY, 0%), or pooled (all) patients ($149,857/LY, 1%). Sensitivity analyses found that screening approached cost-effectiveness among adjuvant patients with the highest reported rates of undiagnosed chronic HBV (65%, $59,445/LY) or HBV reactivation with chemotherapy (41%, $56,537/LY). Cost- effectiveness was also significantly influenced by HBV population prevalence. An alternative screening strategy using hepatitis B surface antigen testing only produced the most economically favorable results, with $30,126/LY (80% probability) for adjuvant patients and $51,201/LY (43%) for the pooled cohort. Universal HBV screening conducted per current guidelines is not cost-effective in patients with STs. Screening may be economically favorable in selected patient subpopulations and/or with simplification of the screening strategy.

Abstract 788: Uptake and cross-presentation of the leukemia associated antigens neutrophil elastase (NE) and proteinase-3 (P3) increases susceptibility of solid tumors to PR1-targeted immunotherapy

Abstract 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 NE and P3 cross-presentation by B-cells and dendritic cells. Because NE and P3 are present in lung and breast cancer tumor tissue, we investigated whether uptake of NE and P3 might result in PR1 expression on solid tumors, which could induce susceptibility of non-hematopoietic tumors to PR1-targeted immunotherapy. We studied melanoma, breast, ovarian and lung cancer cell lines to determine whether NE and P3 are cross-presented. Using flow cytometry, we show that numerous malignant cell lines take up 5 to 10 °g/ml of soluble NE and P3 and was dose- and time-dependent, consistent with a receptor-mediated mechanism. In addition to soluble NE and P3, uptake of granulocyte-associated NE and P3 was also demonstrated; however, uptake of soluble NE and P3 were 3- and 2-fold higher, when compared to granulocyte-associated proteins. Within 4 hours of uptake, confocal microscopy showed that soluble P3 localized to endosomes and lysosomes, suggesting the possibility of lysosomal degradation of P3, a common pathway for MHC-I processing of cross-presented proteins. With the use of 8F4, a monoclonal antibody that is specific for a PR1/HLA-A2 conformational epitope, we show that PR1/HLA-A2 is expressed by 12-hours on P3- and NE-pulsed HLA-A2+ melanoma and breast cancer cell lines. Because 8F4 mediates complement-dependent cytotoxicity (CDC) of AML, we studied whether PR1 expression induced susceptibility of P3- and NE-pulsed tumor cells to killing by 8F4 and PR1-CTL. Twelve hours after pulsing the HLA-A2+ breast cancer cell lines MDA-MB-453 and MDA-MB-231 with P3 or NE, up to 40% and 60% of pulsed breast cancer cells were lysed by PR1-CTL and 8F4, respectively. We conclude that PR1 is cross-presented by solid tumors following receptor-mediated uptake of soluble NE and P3 at concentrations observed in tumors and inflammatory sites. Importantly, this cross-presentation increased susceptibility of embryological distinct tumors to PR1-specific immunotherapy. Together, these data suggest that cross-presentation of extracellular inflammatory proteins that are normally not expressed in the tumor may be a mechanism shared by many tumors, which could be exploited by immunotherapy strategies targeting these proteins. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 788. doi:10.1158/1538-7445.AM2011-788