Edgar Selzer

Impact of hemoglobin level and use of recombinant erythropoietin on efficacy of preoperative chemoradiation therapy for squamous cell carcinoma of the oral cavity and oropharynx

PURPOSE We assessed the influence of hemoglobin level and r-HuEPO administration on response to chemoradiotherapy, locoregional tumor control, and overall survival in patients treated with neoadjuvant chemoradiotherapy and surgery for a squamous cell carcinoma of the oral cavity or oropharynx. METHODS AND MATERIALS The 191 study patients were treated with mitomycin C (15 mg/m(2) day 1), 5-fluorouracil (750 mg/m(2)/day, days 1-5), and radiotherapy (50 Gy in 25 fractions weeks 1-5), followed by resection of the primary tumor bed and neck dissection at the General Hospital Vienna, Austria, between November 1989 and October 1998 for a T2-4, N0-3, M0 SCC of the oral cavity or oropharynx. Starting in May 1996, patients with a low hemoglobin (Hgb) before or during chemoradiotherapy received r-HuEPO 10,000 IU/kg s.c. 3-6 times/week until the week of surgery. RESULTS On multivariate analysis, Hgb level and use of r-HuEPO were independent prognostic factors for response to chemoradiotherapy and locoregional tumor control (p < 0.01). Pathologic response to neoadjuvant therapy was also predictive of locoregional control (p < 0.001). Patients with a pretreatment Hgb > or = 14.5 g/dL had significantly higher complete response, locoregional control, and survival rates than the patients with a pretreatment Hgb < 14.5 g/dL who did not receive r-HuEPO (p < 0.05). The response, control, and survival rates in patients with a pretreatment Hgb < 14.5 g/dL given r-HuEPO were significantly higher than in low Hgb patients not given r-HuEPO (p < or = 0.001) and equivalent to patients with a pretreatment Hgb > 14.5 g/dL (p > or = 0.3). CONCLUSION Low pretreatment Hgb is a negative prognostic factor for oral cavity and oropharyngeal SCCA patients, but was completely abrogated by r-HuEpo administration during neoadjuvant chemoradiotherapy. Randomized trials of radiation and/or chemotherapy with or without r-HuEPO for patients whose Hgb level is either low at the start of therapy or is anticipated to become low during therapy are indicated.

Identification of Heme Oxygenase-1 As a Novel BCR/ABL-Dependent Survival Factor in Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is a stem cell disease in which BCR/ABL promotes the survival of leukemic cells. Heme oxygenase-1 (HO-1) is an inducible stress protein that catalyzes the degradation of heme and has recently been implicated in the regulation of growth and survival of various neoplastic cells. In the present study, we analyzed the expression and role of HO-1 in CML cells. As assessed by Northern and Western blot analysis as well as immunostaining, primary CML cells were found to express HO-1 mRNA and the HO-1 protein in a constitutive manner. Exposure of these cells to the BCR/ABL tyrosine kinase inhibitor STI571 resulted in decreased expression of HO-1 mRNA and protein. In addition, BCR/ABL was found to up-regulate HO-1 promoter activity, mRNA levels, and protein levels in Ba/F3 cells. To investigate the role of HO-1 for survival of primary CML cells, the HO-1 inducer hemin was used. Hemin-induced expression of HO-1 was found to protect CML cells from STI571-induced cell death. In addition, inhibition of HO-1 by zinc-(II)-deuteroporphyrin-IX-2,4-bisethyleneglycol resulted in a substantial decrease of cell viability. Furthermore, overexpression of HO-1 in the CML-derived cell line K562 was found to counteract STI571-induced apoptosis. Together, our data identify HO-1 as a novel BCR/ABL-driven survival molecule and potential target in leukemic cells in patients with CML. The pathogenetic and clinical implications of this observation remain to be elucidated.

Expression of the target receptor CD33 in CD34+/CD38-/CD123+ AML stem cells.

Background  CD33 (Siglec‐3) is becoming increasingly important as a target of antibody‐mediated therapy in acute myeloid leukaemia (AML). In normal myelopoiesis, expression of CD33 is restricted to advanced stages of differentiation, whereas primitive stem cells do not express CD33. In the present study, we asked whether leukaemic stem cells in patients with AML express CD33.

The Role of Non‐Deletional Tolerance Mechanisms in a Murine Model of Mixed Chimerism with Costimulation Blockade

Peripheral and central clonal deletion are important tolerance mechanisms in models using bone marrow transplantation (BMT) with costimulation blockade (CB). However, since tolerance can be found before peripheral deletion is complete and since elimination of recipient CD4+ cells at the time of BMT prevents tolerance induction, we investigated the potential roles of regulation and anergy in such a murine model. We found that transient elimination of CD25+ cells or neutralization of IL2 immediately after BMT and CB prevented the induction of skin graft tolerance. Cotransfer into SCID mice of CD4+ cells taken from chimeras early after BMT, together with naïve recipient‐type CD4+ cells significantly prolonged donor skin graft survival. In contrast, cotransfer of CD4+ cells harvested from chimeras late after BMT did not prolong donor skin graft survival. Besides, depletion of CD25+ cells in established chimeras several months post‐BMT did not break tolerance. In vivo administration of recombinant IL2 inhibited chimerism and tolerance neither early nor late post‐BMT, arguing against a decisive role for classical anergy. Thus, CD4 cell‐mediated regulation contributes significantly to tolerance induction early after BMT, but appears to have no critical role in the maintenance of tolerance.

Impact of multiple HPV infection on response to treatment and survival in patients receiving radical radiotherapy for cervical cancer

To obtain information on the incidence and the clinical significance of infection with various types of the human papillomavirus (HPV) in cancer of the uterine cervix, we retrospectively examined the HPV status of 106 patients who had received radical radiotherapy for cervical cancer stages IB to IIIB. DNA was extracted from formalin‐fixed, paraffin‐embedded biopsies and PCR was carried out to identify HPV types 16, 18, 31, 35, 33 and 45. To detect additional HPV types, consensus PCR products were cloned and sequenced. A catalyzed signal‐amplified colorimetric in situ hybridization was carried out in 84 of 106 specimens as a positive control. Response to therapy, progression‐free survival (PFS) and cervical cancer‐specific survival (CCSS) were the statistical endpoints. Survival analysis was carried out using univariate and multivariate analysis (Cox regression). Ninety‐six patients (90.6%) were HPV‐positive and 42/96 (43.7%) were positive for multiple HPV types. Eight patients had persistent disease after radiotherapy. From these 8 patients, 7 were infected with multiple HPV types and only 1 patient had an infection with a single HPV type. After a median follow up period of 50 months, patients with multiple HPV infection had a significantly shorter PFS and CCSS compared to those with single HPV infection (24.8% and 34.9% vs. 64% and 60.8%, Log rank, p < 0.01 and 0.04). In multivariate analysis, the presence of multiple HPV types (RR 1.9), node status (RR 2.3), tumor size (RR 3.2) and histologic type (RR 4.8) were independent prognostic factors of CCSS. Our results demonstrate that the presence of multiple HPV types is associated with poor response and with reduced survival in cervical cancer patients who receive radiotherapy as the primary treatment.

Betulinic acid: a new cytotoxic compound against malignant head and neck cancer cells.

A new compound, betulinic acid, has been found to be cytotoxic against a variety of tumor cells originating from the neural crest. Its efficacy against head and neck squamous cellular carcinoma cell lines has so far not been tested.

Mcl-1 Is a Novel Therapeutic Target for Human Sarcoma: Synergistic Inhibition of Human Sarcoma Xenotransplants by a Combination of Mcl-1 Antisense Oligonucleotides with Low-Dose Cyclophosphamide

Purpose: Little is known about the role that Mcl-1, an antiapoptotic Bcl-2 family member, plays in solid tumor biology and susceptibility to anticancer therapy. We observed that the Mcl-1 protein is widely expressed in human sarcoma cell lines of different histological origin (n = 7). Because the expression of antiapoptotic Bcl-2 family proteins can significantly contribute to the chemoresistance of human malignancies, we used an antisense strategy to address this issue in sarcoma. Experimental Design: SCID mice (n = 6/group) received s.c. injections of SW872 liposarcoma cells. After development of palpable tumors, mice were treated by s.c.-implanted miniosmotic pumps prefilled with saline or antisense or universal control oligonucleotides (20 mg/kg/day for 2 weeks). On days 2, 6, and 10, mice were treated with low-dose cyclophosphamide (35 mg/kg i.p) or saline control. During the experiments, tumor weight was assessed twice weekly by caliper measurements. On day 14, animals were sacrificed. Tumors were weighed and fixed in formalin for immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling analysis. Results: Mcl-1 antisense oligonucleotides specifically reduced Mcl-1 protein expression but produced no reduction in tumor weight compared with saline-treated control animals. Cyclophosphamide monotreatment caused only modest tumor weight reduction compared with saline control. However, use of Mcl-1 antisense oligonucleotides combined with cyclophosphamide clearly enhanced tumor cell apoptosis and significantly reduced tumor weight by more than two-thirds compared with respective control treatments. Conclusion: A combination of Mcl-1 antisense oligonucleotides with low-dose cyclophosphamide provides a synergistic antitumor effect and might qualify as a promising strategy to overcome chemoresistance in human sarcoma.

On the way to targeted therapy of mast cell neoplasms: identification of molecular targets in neoplastic mast cells and evaluation of arising treatment concepts

Several emerging treatment concepts for myeloid neoplasms are based on novel drugs targeting cell surface antigens, signalling pathways, or critical effector molecules. Systemic mastocytosis is a haematopoietic neoplasm that behaves as an indolent myeloproliferative disease in most patients, but can also present as aggressive disease or even as an acute leukaemia. In patients with aggressive disease or mast cell leukaemia, the response to conventional therapy is poor in most cases, and the prognosis is grave. Therefore, a number of attempts have been made to define novel treatment strategies for these patients. One promising approach may be to identify novel targets and to develop targeted drug therapies. In this article, we support the notion that neoplastic mast cells indeed express a number of potential molecular targets including immunoreactive CD antigens, the microphthalmia transcription factor (MITF), and members of the Bcl‐2 family. In addition, the tyrosine kinase receptor KIT and downstream signalling pathways have been proposed as targets of a specific pharmacological intervention. A particular challenge is the disease‐related D816V‐mutated variant of KIT, which is resistant against diverse tyrosine kinase inhibitors including STI571, but may be sensitive to more recently developed targeted compounds. The therapeutic potential of target‐specific approaches in malignant mast cell disorders should be evaluated in forthcoming clinical trials in the near future.

Antiinflammatory effects of tumor necrosis factor on hematopoietic cells in a murine model of erosive arthritis

OBJECTIVE To investigate the mechanisms leading to the influx of inflammatory hematopoietic cells into the synovial membrane and the role of tumor necrosis factor receptor I (TNFRI) and TNFRII in this process in an animal model of rheumatoid arthritis (RA). METHODS We performed bone marrow transplantations in human TNF-transgenic mice using hematopoietic cells from wild-type, TNFRI(-/-), TNFRII(-/-), and TNFRI/II(-/-) mice as donors and assessed the severity of arthritis histologically. Generation of osteoclasts from the different genotypes was analyzed in vitro and in vivo. Apoptosis was analyzed using annexin V staining as well as TUNEL assays. RESULTS Despite lacking responsiveness to TNF in their hematopoietic compartment, mice not only developed full-blown erosive arthritis but even showed increased joint destruction when compared with mice with a TNF-responsive hematopoietic compartment. We demonstrated different roles of the 2 different TNFRs in the regulation of these processes. The absence of TNFRI on hematopoietic cells did not affect joint inflammation but markedly attenuated erosive bone destruction via reduced synovial accumulation of osteoclast precursors. In contrast, the absence of TNFRII on hematopoietic cells increased joint inflammation as well as erosive bone destruction via the regulation of osteoclast precursor apoptosis. CONCLUSION Our findings indicate that selective blockade of TNFRI, leaving the antiinflammatory effects of TNFRII unaltered instead of unselectively blocking TNF, might be advantageous in patients with RA.

Serum VEGF levels in patients undergoing primary radiotherapy for cervical cancer: impact on progression-free survival

Vascular endothelial growth factor (VEGF) plays an important role in the regulation of tumour growth and metastasis. It was the aim of this study to examine the impact of serum VEGF levels on the likelihood of response to radiotherapy and on the disease-free survival in patients with cervical cancer. Blood was taken before commencing treatment and serum VEGF was assessed by quantitative ELISA in 23 patients with cervical cancer stage IB-IVA undergoing primary radiotherapy. Serum VEGF levels were correlated with clinical and histopathologic factors as well as with response to radiotherapy and time to progression. Nineteen of the 23 patients had a complete response and four patients had persistent disease at 3 months. The median follow-up was 25 months (95% confidence interval: 23.5-26.5 months). At the time of analysis, eight patients were tumour-free and 15 patients had tumour progression; 12 of these 15 patients died of disease. Overall, the median serum VEGF level was 244 pg/ml (range 31.9-817.6 pg/ml). All four patients with local failure had VEGF levels >244 pg/ml, whereas 11 of the 19 patients with complete response had serum VEGF of < or =244 pg/ml (P=0.035). The median time to progression was 5 months in patients with VEGF of >244 pg/ml compared to 19 months in patients with VEGF of < or = 244 pg/ml (log rank, P=0.003). In multivariate analysis, serum VEGF, tumour size and histological type, but not the patients age, stage and grade of histological differentiation influenced the progression-free survival. Elevated pre-therapeutic serum VEGF levels are associated with poor response and a shorter time to progression in patients with cervical cancer undergoing primary radiotherapy.