Erste Ergebnisse der neoadjuvanten simultanen Radiochemotherapie bei fortgeschrittenen Rektumkarzinomen

Hintergrund: Bei lokal weit fortgeschrittenen Rektumkarzinomen ist das Erreichen eine R0-Resektion schwierig. Muss jedoch makroskopisch oder mikroskopisch Tumorrest zurückgelassen werden, ist die Prognose der Patienten schlecht. In den Leitlinien empfiehlt die Deutsche Krebsgesellschaft deshalb bei Patienten mit T4-Tumoren eine präoperative simultane Radiochemotherapie. Patienten und Methodik: Vom 1.5.1997 bis 30.11.1999 wurde bei 22 Patienten eine neoadjuvante Radiochemotherapie durchgeführt. Appliziert wurde eine Dosis von 45 Gy zuzüglich eines Boostes von 5,4 Gy. In der ersten und fünften Bestrahlungswoche erhielten die Patienten an fünf aufeinander folgenden Tagen eine Dosis von täglich 1000 mg/m² 5-FU als intravenöse Dauerinfusion über 24 Stunden. Bei auftretender Kardiotoxizität wurde die Chemotherapie auf 5-FU-Bolusinfusion oder Ralitrexed umgestellt. Ergebnisse: 19/22 Patienten konnten einer Operation zugeführt werden. Bei 16/19 (84%) der operierten Patienten konnte eine R0-Resektion erreicht werden. Eine funktionserhaltende Behandlung war bei 9/19 (47%) Patienten möglich. Ein Downstaging um mindestens eine T-Kategorie wurde bei 12/19 (63%) Patienten erzielt. Bei einer medianen Nachbeobachtungszeit von 16 Monaten ist bisher kein lokales Rezidiv bei den operierten Patienten aufgetreten. Das progressionsfreie Überleben der operierten Patienten (R0/R1) beträgt nach zwei Jahren 62%, die Überlebensrate 89%, bezogen auf alle Patienten 76%. Schlussfolgerung: Die präoperative simultane Radiochemotherapie kann zu einer verbesserten Rate an R0-Resektionen und sphinktererhaltenden Eingriffen betragen. Purpose: In locally advanced rectal cancer tumor-negative margins often cannot be obtained by surgery alone. Nevertheless only patients with complete tumor resection can be cured. Due to the poor prognosis of patients with R1/R2 resection the "Deutsche Krebsgesellschaft" recommends concurrent preoperative radiochemotherapy for patients with locally advanced rectal cancer. Patients and Methods: Between May 1997 and November 1999 22 patients were treated with preoperative radiochemotherapy. A total dose of 45 Gy with a small-volume boost of 5.4 Gy was delivered in conventional fractionation (single dose 1,8 Gy). On days 1 to 5 and 29 to 33 patients received concurrently 5-fluorouracil (5-FU) as continuous infusion of 1,000 mg/m². If there was any sign of cardiac toxicity chemotherapy was changed to 5-FU/folinic acid or ralitrexed. Results: Surgery following radiochemotherapy was performed in 19/22 patients. Resections with negative margins were achieved in 16/19 (84%) patients. Sphincter-conserving surgery was possible in 9/19 (47%) patients. A downstaging of at least 1 T category was found in 12/19 (63%) patients. With a median follow-up of 16 months no locoregional recurrences occurred in patients who underwent surgery. Two-year disease-free survival of resected patients is 62%, 2-year overall survival is 89%, of the whole population 76%. Conclusion: Preoperative radiochemotherapy followed by surgery is able to achieve clear resection margins in more than 70% of patients with locally advanced rectal cancer and may improve the rate of sphincter-conserving surgery.     

Expression of late cell cycle genes and an increased proliferative capacity characterize very early relapse of childhood acute lymphoblastic leukemia.

PURPOSE: In childhood acute lymphoblastic leukemia (ALL), approximately 25% of patients suffer from relapse. In recurrent disease, despite intensified therapy, overall cure rates of 40% remain unsatisfactory and survival rates are particularly poor in certain subgroups. The probability of long-term survival after relapse is predicted from well-established prognostic factors (i.e., time and site of relapse, immunophenotype, and minimal residual disease). However, the underlying biological determinants of these prognostic factors remain poorly understood. EXPERIMENTAL DESIGN: Aiming at identifying molecular pathways associated with these clinically well-defined prognostic factors, we did gene expression profiling on 60 prospectively collected samples of first relapse patients enrolled on the relapse trial ALL-REZ BFM 2002 of the Berlin-Frankfurt-Münster study group. RESULTS: We show here that patients with very early relapse of ALL are characterized by a distinctive gene expression pattern. We identified a set of 83 genes differentially expressed in very early relapsed ALL compared with late relapsed disease. The vast majority of genes were up-regulated and many were late cell cycle genes with a function in mitosis. In addition, samples from patients with very early relapse showed a significant increase in the percentage of S and G(2)-M phase cells and this correlated well with the expression level of cell cycle genes. CONCLUSIONS: Very early relapse of ALL is characterized by an increased proliferative capacity of leukemic blasts and up-regulated mitotic genes. The latter suggests that novel drugs, targeting late cell cycle proteins, might be beneficial for these patients that typically face a dismal prognosis.     

Upregulation of Bcl-2 is involved in the mediation of chemotherapy resistance in human small cell lung cancer cell lines.

Chemotherapeutic drugs eliminate cancer cells by induction of apoptosis. Resistance to chemotherapy is partly due to a decreased apoptosis rate. Here we investigated resistance to anticancer drugs in 9 small cell lung cancer (SCLC) cell lines. Apoptosis was induced by cisplatin, doxorubicin and etoposide and was found to be independent of caspase-8 expression. Since caspase-8 is essential for signal transduction of death receptor-mediated apoptosis, all known death receptor systems are thus not required for drug-induced apoptosis in SCLC. Furthermore, we found that anticancer drugs could activate the mitochondrial pathway of apoptosis without involvement of upstream caspases. Finally, by culturing 3 sensitive cell lines in subtherapeutic concentrations of etoposide, resistant cells were generated that exhibit cross-resistance to cisplatin and doxorubicin. Drug resistance was paralleled by strong upregulation of Bcl-2, which diminished apoptosis by inhibiting the loss of the mitochondrial transmembrane potential and the release of cytochrome c. The role of bcl-2 in these processes was supported by bcl-2 transfection and antisense inhibition. These results indicate that Bcl-2 contributes to drug resistance in SCLC, a finding that has profound therapeutic implications.     

Serum levels of insulin-like growth factor-I,-II and insulin-like growth factor binding proteins-2 and-3 in children with acute lymphoblastic leukaemia

Abstract The insulin-like growth factor (IGF) signaling pathway may be of importance for the proliferation of different tumours (e.g. breast cancer and Wilms tumour). The bioavailability of both IGF-I and IGF-II is regulated by specific IGF-binding proteins (IGFBPs). IGFBP-2 is the predominant binding protein during fetal life, where it is expressed in most tissues. In contrast, postnatally it is mainly released by specific cell types (hepatocytes, astroglia, kidney cells, prostate cells) and a range of tumour cell lines. Furthermore, phytohaemagglutinin stimulated normal lymphoblasts and malignant lymphoblasts express IGFBP-2. In order to investigate the IGF regulatory pathway in leukaemia serum levels of IGF-I, IGF-II, IGFBP-2 and IGFBP-3 were determined in 28 leukaemic children. Whereas serum levels of IGF-I (mean/range: –2.7/–0.1 to –6.7 SDS), IGF-II (–3.6 SDS/–1.3 to –8.7) and IGFBP-3 (–2.0/+2.2 to –7.1 SDS) were significantly decreased comparable to levels in growth hormone deficiency, IGFBP-2 levels (+4.0/–0.45 to +7.4 SDS) were found to be markedly elevated and inversely correlated to IGF-I (r=–0.51,P=0.013). After haematological remission upon chemotherapy all four parameters had normalized in the 16 re-investigated children. Similar findings have been observed in one boy with a relapse including CNS leukaemia.Conclusion This study demonstrates that the proliferation of malignant lymphoblasts (at diagnosis vs treatment) occurs in the presence of decreased serum levels of IGF-I, IGF-II and IGFBP-3 and that diminished production of these peptides may contribute to impaired growth. It further indicates that serum levels of IGFBP-2 may be directly related to the proliferation of lymphoblasts.     

In-vitro Cell Culture Models of the Nasal Epithelium: A Comparative Histochemical Investigation of Their Suitability for Drug Transport Studies

Purpose. To evaluate different in-vitro cell culture models for their suitability to study drug transport through cell monolayers. Methods. Bovine turbinate cells (BT; ATCC CRL 1390), human nasal septum tumor cells (RPMI, 2650; ATCC CCL 30), and primary cell cultures of human nasal epithelium were characterized morphologically and histochemically by their lectin binding properties. The development of tight junctions in culture was monitored by actin staining and transepithelial electrical resistance measurements. Results. The binding pattern of thin-sections of excised human nasal respiratory epithelium was characterized using a pannel of fluorescently-labelled lectins. Mucus in goblet cells was stained by PNA, WGA and SBA, demonstrating the presence of terminal N-acetylglucosamine, N-acetylgalactosamine and galactose residues respectively in the mucus of human nasal cells. Ciliated cells revealed binding sites for N-acetylglucosamine, stained by WGA, whereas Con A, characteristic for mannose moieties, labelled the apical cytoplasm of epithelial cells. Binding sites for DBA were not present in this tissue. Comparing three different cell culture models: BT, RPMI 2650, and human nasal cells in primary culture using three lectins (PNA, WGA, Con A) as well as intracellular actin staining and transepithelial electrical resistance measurements we found, that only human nasal epithelial cells in primary culture showed differentiated epithelial cells, ciliated nasal cells and mucus producing goblet cells, which developed confluent cell monolayers with tight junctions. Conclusions. Of the in-vitro cell culture models studied, only human nasal cells in primary culture appears to be suitable for drug transport studies.     

Der in vitro-Effekt der Hyperthermie auf den Einbau von Nucleinsäurevorläufern in Tumoren und normale Gewebe

Zusammenfassung Die Inkorporation von Präkursoren der Nucleinsäuresynthese wie ³H-Thymidin und ³H-Uridin in Zellen schnell proliferierender Gewebe kann in vitro durch Erhöhung der Temperatur im Inkubationsansatz auf 39,0° C und 41,0° C gehemmt werden. Tumorgewebe, embryonale Gewebe und regenerierende Leber verhalten sich dabei gleichartig. Die Hemmwirkung ist bei allen diesen Geweben proportional sowohl zum Ausmaß als auch zur Dauer der Temperaturerhöhung. Unsere Befunde sprechen außerdem für eine individuelle Wärmesensibilität der untersuchten Tumoren und der anderen rasch proliferierenden Gewebe. Die gleichzeitige Anwendung von Wärme und Bleomycin führt weder beim Jensen Sarkom noch beim Tumor GW-39 zu einem Additionseffekt. Dagegen zeigen Hydroxyharnstoff und Wärme gleichzeitig angewendet eine additive Hemmwirkung auf den ³H-Thymidineinbau in den Tumor GW-39.Da entsprechende Temperatureinflüsse bei ruhenden Geweben nicht nachzuweisen sind, scheint es sich bei der beobachteten Temperaturempfindlichkeit um eine Besonderheit proliferierender Zellsysteme zu handeln. Es ist daher zu klären, ob sie nur unter den Bedingungen des in vitro-Versuches zum Ausdruck kommt oder, ob sie als Indiz einer allgemeinen Thermosensibilität der Nucleinsäurebiosynthese bei schnell proliferierenden Zellverbänden angesehen werden muß.

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In vitro effect of hyperthermia on the incorporation rate of nucleic acid precursors in tumours and normal tissues

Summary The incorporation of precursors of the nucleic acid synthesis, such as ³H-thymidine and ³H-uridine, in cells of rapidly proliferating tissues can be inhibited in vitro by increasing the temperature in the early stages of incubation from 37–39° C and to 41° C. Tumour tissues, embryo tissues and regenerating liver react to this in the same way. The degree of inhibition in all these tissues is proportionate to both the extent and the duration of the increase in temperature. Our findings also speak for an individual sensitivity to heat among the tumours tested and among other rapidly proliferating tissues. The simultaneous application of heat and Bleomycin leads to no additive effect either with Jensen's sarcoma or with tumour GW-39. On the other hand, hydroxyurea and heat applied simultaneously show an additive inhibitory effect on the incorporation of ³H-thymidine in tumour GW-39.As no corresponding influences of temperature are to be proved with non-proliferating tissues, the observed sensitivity to temperature appears to be a peculiarity of proliferating cell systems. The question must therefore be clarified as to whether this sensitivity is expressed only under the conditions of the in vitro experiment or whether it is to be regarded as evidence of a general sensitivity to heat in the nucleic acid biosynthesis of rapidly proliferating groups of cells.

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Mit Unterstützung der Deutschen Forschungsgesellschaft.     

Latent membrane protein 1 of Epstein-Barr virus coordinately regulates proliferation with control of apoptosis

Latent membrane protein 1 (LMP1), an oncoprotein encoded by Epstein-Barr virus (EBV), is an integral membrane protein, which acts like a constitutively active receptor. LMP1 is critical for some facet of EBV's induction and maintenance of proliferation of infected B cells. It, in part, mimics signaling by the CD40 receptor and has been implicated in regulating proliferation, survival, or both properties of EBV-infected cells. We established a conditional LMP1 allele in the context of the intact EBV genome to define the immediate-early cellular target genes regulated by LMP1 in order to assess its contributions to infected human B cells. The functional analysis of this conditional system indicated that LMP1 specifically induces mitogenic B-cell activation through c-myc and Jun/AP1 family members and confirms its direct role in upregulating expression of multiple genes with opposing activities involved in cell survival. LMP1's signals were found to be essential for the G1/S transition in human B cells; cells lacking LMP1's signals are cell cycle arrested and survive quiescently. LMP1's activities are therefore not required to maintain survival in nonproliferating cells. LMP1 does induce both pro- and antiapoptotic genes whose balance seems to permit survival during LMP1's induction and maintenance of proliferation.     

German populations with infrequent CHEK2*1100delC and minor associations with early-onset and familial breast cancer

CHEK2*1100delC is associated with a twofold increased breast cancer risk. This was shown in a collaborative analysis of European populations, but not in other populations from Europe and the US. Accordingly, there is a need to clarify the role of CHEK2*1100delC in breast cancer.We established its prevalence in two German populations GENICA (Northrhine-Westphalia, n = 724) and KORA (Bavaria, n = 600) and in women with breast cancer. The latter included cases (n = 688) from the GENICA breast cancer case-control study, patients with early-onset breast cancer (n = 86) and patients with familial breast cancer (n = 71). The latter patient groups were previously investigated for BRCA1/2-mutations and tested negative. Mutation analysis was performed by combined PCR/DHPLC methodology.CHEK2*1100delC was found in 0.9% of GENICA controls and was absent in the KORA controls indicating a significant difference between the two populations (P = 0.03). The frequency of CHEK2*1100delC in age-matched cases of the GENICA collection was 0.8% and thus not different from controls (OR 0.88, 95% CI 0.21–3.50). In patients with early-onset disease CHEK2*1100delC was found at a frequency of 2.3% referring to an increased breast cancer risk of 2.56 (95% CI 0.25–14.58). In patients with familial disease the frequency was 1.4% referring to an increased risk of 1.53 (95% CI 0.03–12.93).Our data showed variations in CHEK2*1100delC prevalence within German populations suggesting possible inaccuracies in breast cancer risk assessments from non population-based studies. In patients with a high-risk profile however, CHEK2*1100delC was indicative for this risk and highest for early-onset breast cancer.