The distribution of drug-efflux pumps, P-gp, BCRP, MRP1 and MRP2, in the normal blood-testis barrier and in primary testicular tumours

The drug-efflux pumps P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) are present in the blood-testis barrier (BTB) and may hamper the delivery of cytotoxic drugs to the testis. The precise localisation of P-gp and MRP1 in testicular tissue and the presence of the efflux pumps MRP2 and breast cancer resistance protein (BCRP) in the BTB are unknown. We therefore studied the localisation of these pumps in the BTB in normal testis (n = 12), in non-seminoma (n = 10) seminoma (n = 10), and testicular lymphoma (n = 9). Slides were scored semi-quantitatively for P-gp, MRP1, MRP2 and BCRP and blood vessels with factor VIII antibody. In normal testis, P-gp and BCRP were strongly expressed by myoid cells and luminal capillary endothelial wall and P-gp also by Leydig cells. MRP1 was observed at the basal side of Sertoli cells and on Leydig cells. MRP2 was only weakly expressed by myoid cells. Seminomas and non-seminomas expressed P-gp and/or BCRP and/or MRP1, lymphomas strongly expressed P-gp, weakly expressed BCRP and did not or showed weak expression of MRP1. There was very little staining for MRP2 in the tumours. Newly formed vessels in all tumours only expressed P-gp and BCRP. P-gp, BCRP and MRP1 are present in different cell layers of the normal testis, suggesting the optimal protection of spermatogenesis. In germ cell tumours, this expression pattern may explain the chemoresistance observed to P-gp, BCRP and MRP1 substrates. In germ cell tumours and testicular lymphomas, P-gp and BCRP expression by tumour cells and by newly formed vessels may also contribute to chemoresistance. These findings underscore the importance of removing the affected testis in cases of primary germ cell tumours and testicular lymphomas, irrespective of whether the patient has already undergone chemotherapy.

Portal and systemic serum growth factor and acute-phase response after laparotomy or partial hepatectomy in patients with colorectal liver metastases: a prognostic role for C-reactive protein and hepatocyte growth factor

BACKGROUND

Growth factors play a role in wound healing and tumour growth. The aim of this study was to compare the effect of partial hepatectomy (PH) and laparotomy on serum levels of growth factors and acute-phase proteins in patients with colorectal liver metastases and to correlate these levels with prognosis after PH.

METHODS

Epidermal growth factor (EGF), hepatocyte growth factor (HGF), insulin like growth factor-I (IGF-I), insulin, interleukin-6 (IL-6), C-reactive protein (CRP) and serum amyloid-A (SAA) were determined in portal and systemic serum in 24 PH patients and 9 laparotomy patients.

RESULTS

No differences were found in the clinicopathological characteristics of PH and laparotomy patients with the exception of the number of metastases, blood loss and operation time. The response of SAA, CRP and IGF-I was lower in PH patients than in laparotomy patients (P < 0.02). PH was associated with a higher IL-6 (P = 0.02) and HGF (P = 0.055) response than laparotomy. A higher HGF and CRP response was associated with a poorer prognosis. Total IGF-I was negatively correlated with the resected liver volume (r = -0.48, P < 0.05).

CONCLUSIONS

PH is associated with a lower acute-phase and total IGF-I response and a higher HGF and IL-6 response compared with laparotomy. HGF and CRP responses had an influence on the prognosis.

The happy destiny of frozen haematopoietic stem cells: from immature stem cells to mature applications

Forty years ago, van Putten described in the European Journal of Cancer (see this issue) quantitative studies on the optimal storage techniques of mouse and monkey bone marrow suspensions. Survival of the animals after irradiation following injection with stored bone marrow cell suspensions was the endpoint. He observed some species differences, but based on the data obtained considered a careful trial of the glycerol-polyvinylpyrrolide (PVP) combination for storage of marrow in man was indicated. In spite of this, dimethyl sulphoxide has become the 'standard' cryopreservant for human marrow stem cells. Over the last 40 years, there has been a tremendous increase in knowledge about haematopoietic stem cells and their use in the clinic. Haematopoietic stem cells are now known to travel between the bone marrow and peripheral blood and are the best-characterised adult stem cells. These cells are currently widely used for transplantations in the clinic and are obtained from a wide variety of sources. These include the bone marrow, peripheral blood, cord blood, autologous as well as allogeneic stem cells from related or unrelated donors. Increasingly, data has become available that adult haematopoietic stem cells can generate differentiated cells belonging to other cell types, a process called "developmental plasticity". Thus, they may contribute to non-haematopoietic tissue repair in multiple organ systems. This has created a whole new potential therapeutic armamentarium for the application of haematopoietic stem cells outside of the area of malignancies and haematopoietic disorders.

Endothelial cell effects of cytotoxics: balance between desired and unwanted effects

Since Folkman defined angiogenesis more than 25 years ago as the most important process in tumour growth and metastasis, specific anti-angiogenic agents have been developed. One obvious route to block this process was until recently overlooked, however. Tumour endothelial cells are different from normal endothelial cells and may respond differently to conventional cytotoxics. Chemotherapeutic-induced vascular toxicity has been observed in various clinical studies and seems to be based on endothelial cell damage as seen in vitro in human umbilical vein endothelial cells (HUVEC) models with protracted low-dose cytostatic exposure. Translated into the clinical setting, such "metronomically" administered chemotherapy could lead to anti-angiogenesis enhancing anti-tumour efficacy of cytostatic drugs. This paper reviews the desired anti-tumour endothelial activity versus the unwanted general vascular toxicity of cytostatic drugs. Several ways to enhance the anti-tumour activity and to circumvent the unwanted vascular toxicity of these "accidental" anti-angiogenic drugs will be discussed.

A phase I study with MAG-camptothecin intravenously administered weekly for 3 weeks in a 4-week cycle in adult patients with solid tumours

In MAG-camptothecin (MAG-CPT), the topoisomerase inhibitor camptothecin is linked to a water-soluble polymer. Preclinical experiments showed enhanced antitumour efficacy and limited toxicity compared to camptothecin alone. Prior phase I trials guided the regimen used in this study. The objectives were to determine the maximum tolerated dose, dose-limiting toxicities, safety profile, and pharmacokinetics of weekly MAG-CPT. Patients with solid tumours received MAG-CPT intravenously administered weekly for 3 weeks in 4-week cycles. At the starting dose level (80 mg x m(-2) week(-1)), no dose-limiting toxicities occurred during the first cycle (n=3). Subsequently, three patients were enrolled at the second dose level (120 mg x m(-2) week(-1)). Two of three patients at the 80 mg x m(-2) week(-1) cohort developed haemorrhagic cystitis (grade 1/3 dysuria and grade 2/3 haematuria) during the second and third cycles. Next, the 80 mg x m(-2) week(-1) cohort was enlarged to a total of six patients. One other patient at this dose level experienced grade 1 haematuria. At 120 mg x m(-2) week(-1), grade 1 bladder toxicity occurred in two of three patients. Dose escalation was stopped at 120 mg x m(-2) week(-1). Cumulative bladder toxicity was dose-limiting toxicity at 80 mg x m(-2) week(-1). Pharmacokinetics revealed highly variable urinary camptothecin excretion, associated with bladder toxicity. Due to cumulative bladder toxicity, weekly MAG-CPT is not a suitable regimen for treatment of patients with solid tumours.

Mitoxantrone resistance in a small cell lung cancer cell line is associated with ABCA2 upregulation

The aim of this study was to find factors that could explain the accumulation difference of mitoxantrone in the BCRP1-negative GLC4-MITO cell line compared to GLC4. Comparative genomic hybridisation (CGH) was applied to determine chromosomal differences between GLC4 and GLC4-MITO. Comparative genomic hybridisation analysis revealed gain of 2q, 6p, 9q, 13q, 14q, 15q, 19q and Xp and loss of 1p, 2q, 3p, 3q, 4q, 6q, 8q, 11p, 16p, 17q, 18p, 20p and Xq. In the over-represented chromosomal areas, seven transporter genes were identified: ABCB6, ABCB2 (TAP1), ABCB3 (TAP2), ABCF1 (ABC50), ABCC10 (MRP7), ABCA2 (ABC2) and ABCC4 (MRP4). No RNA or protein upregulation was observed for ABCB6, ABCF1, ABCC10, ABCC4, ABCB2 and ABCB3, but an increased expression was detected for ABCA2 mRNA in GLC4-MITO. ABCA2 is known to be involved in resistance to estramustine. In the MTT assay, GLC4-MITO was two-fold resistant to estramustine compared to GLC4. Coincubation with estramustine and mitoxantrone increased mitoxantrone accumulation in GLC4-MITO, while this was not affected in GLC4. This suggests that estramustine is able to block mitoxantrone efflux in GLC4-MITO cells. These data reveal that cellular reduction of mitoxantrone in a mitoxantrone-resistant cell line is associated with overexpression of ABCA2.

Factors influencing haematological recovery following high-dose chemotherapy and peripheral stem-cell transplantation for haematological malignancies

Peripheral blood counts and factors influencing haematological recovery in 98 patients with a relapse-free survival of > or =1 year treated with high-dose chemotherapy (HDC) and peripheral stem-cell transplantation (PSCT) for haematological malignancies were analysed. One year after PSCT full haematological recovery was demonstrated for haemoglobin (Hb) in 47% of patients, for the white blood cell count (WBC) in 94%, and for platelets in 64%; 39% had a trilineage recovery. In the multivariate analysis, recovery was influenced by age (P=0.002), number of reinfused CD34+ cells (P=0.016), Hb at start of HDC (P=0.001), and platelets at start of HDC (P=0.008). One year following PSCT, 61% of patients still have subnormal values in one or more haematopoietic cell lineage, suggesting a limited bone-marrow reserve. Long-term recovery is highly dependent on age, blood counts at start of HDC and number of reinfused CD34+ cells without a threshold, all reflecting the residual function of bone marrow before HDC. Reinfusing more CD34+ cells can accelerate long-term haematological recovery.

Chemotherapy induces death receptor 5 in epithelial ovarian carcinoma

OBJECTIVES

Defects in the apoptotic pathway are a general cause for drug resistance. Chemotherapy in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has proven to be an effective strategy to induce apoptosis in vitro in ovarian tumor cells. Systemic TRAIL administration might be a therapeutic option, since no toxicity was observed in nonhuman primates. In the present study, expression of TRAIL and its apoptosis-inducing death receptors (DR4 and DR5) and inhibitory decoy receptor (DcR1) was studied in normal ovaries and in malignant ovarian tumors before and after chemotherapy to investigate the therapeutic potential of TRAIL.

METHODS

DR4, DR5, DcR1, and TRAIL were studied immunohistochemically in 5 normal ovaries, 15 stages I/II, and 26 stages III/IV primary ovarian cancers, including 19 paired tumor samples (pre- and post-chemotherapy).

RESULTS

Surface epithelium of normal ovaries expressed TRAIL and its receptors; ovarian stromal cells expressed only DcR1. Of the ovarian cancers, 73% expressed DR4, 51% DR5, 46% DcR1, and 34% TRAIL. Most primary ovarian cancers (88%) expressed at least one death receptor. TRAIL expression was lower in stage III/IV than in stage I/II tumors (P<0.05). In paired samples, DR5 immunostaining was more frequently (P=0.05) and stronger (P<0.01) expressed in residual tumors.

CONCLUSION

Early stage tumors expressed TRAIL more frequently than advanced stage tumors. Most primary and residual ovarian tumors expressed at least one TRAIL death receptor, while in residual tumors following chemotherapy, DR5 was more frequently expressed. Therefore, human recombinant TRAIL administration might be an interesting treatment option.

Development of an optimal sampling strategy for clinical pharmacokinetic studies of the novel anthracycline disaccharide analogue MEN-10755

AIM

MEN-10755 is a novel anthracycline analogue that has shown an improved therapeutic efficacy over doxorubicin in animal models, especially in gynaecological and lung cancers and is currently under clinical development for the treatment of solid tumours. The aim of the project was to develop an optimal sampling strategy for MEN-10755 to provide an efficient basis for future pharmacokinetic/pharmacodynamic investigations.

METHODS

Data from 24 patients who participated in a phase I clinical pharmacokinetic study of MEN-10755 administered as a short i.v. infusion were included. Individual pharmacokinetic values were calculated by fitting the plasma concentration data to a two-compartment model using nonlinear least-squared regression (KINFIT, Ed 3.5). Population pharmacokinetic analysis was carried out using (a) the traditional standard two-stage method (STS) based on all data (KINFIT-ALL), (b) the iterative two-stage Bayesian (IT(2)B) population modelling algorithm (KINPOP), and (c) the STS method using KINFIT and using four optimally timed plasma concentrations (KINFIT-OSS4). Determinant (D) optimal sampling strategy (OSS) was used to evaluate the four most information-rich sampling times. The pharmacokinetic parameters V(c) (l), k(el) (h(-1)), k(12) (h(-1)) and k(21) (h(-1)) calculated using KINPOP served as a model for calculation of four D-optimal sampling times. D-optimal sampling data sets were analysed using KINFIT-OSS4 and compared with the population model obtained by the traditional standard two-stage approach for all data sets (KINFIT-ALL).

RESULTS

The optimal sampling times were: the end of the infusion, and 1.5 h, 3.8 h and 24 h after the start of the infusion. The four-point D-optimal sampling design determined in this study gave individual parameter estimates close to the basic standard estimates using the full data set.

CONCLUSION

Because accurate estimates of pharmacokinetic parameters were achieved, the four-point D-optimal sampling design may be very useful in future studies with MEN-10755.

An in vitro model for purging of tumour cells from ovarian tissue

BACKGROUND

Cryopreservation and autografting of ovarian tissue may preserve fertility after cancer treatment, but could be hampered by tumour cell contamination. Epithelial tumour cell lysis can be obtained with cytotoxic T cell retargeting through the bispecific antibody BIS-1, with combined affinity for the T-cell receptor and epithelial glycoprotein-2 (EGP-2). Our aim was to study the concept of tumour cell purging in the setting of a suspension of ovarian tissue.

METHODS

Human ovarian tissue was brought into suspension by mechanical and enzymatic treatment. Cells of the MCF-7 breast cancer cell line and activated human lymphocytes were co- incubated for 4 h with or without BIS-1 and with or without ovarian suspension. After incubation, MCF-7 cell death and cell growth were evaluated by fluorescent cell detection and MTT assay, respectively. Ovarian tissue morphology was evaluated immunohistochemically.

RESULTS

MCF-7 cell death and cell growth inhibition increased with increasing ratios of lymphocytes to MCF-7 cells. BIS-1 addition gave further augmentation, with a maximum depletion of growing MCF-7 cells of 89% (SD 11%) versus without BIS-1, 23% (SD 15%; P < 0.001). Follicles remained morphologically intact.

CONCLUSIONS

Purging of added epithelial tumour cells from ovarian tissue with BIS-1 is possible in vitro. Morphologically, follicles remain intact after this procedure. This method may contribute to safer replacement of ovarian tissue in female cancer survivors.

Continuously infused carboplatin used as radiosensitizer in locally unresectable non-small-cell lung cancer: a multicenter phase III study

PURPOSE

To determine the radiosensitizing effect of prolonged exposure of carboplatin in patients with locally unresectable non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with histologically proven NSCLC, performance score <2, weight loss <10%, and normal organ functions were randomized between carboplatin 840 mg/m2 administered continuously during 6 weeks of radiotherapy or thoracic radiotherapy alone (both 60 Gy). Toxicity was evaluated with National Cancer Institute Common Toxicity Criteria (NCI CTC) and the Radiation Therapy Oncology Group (RTOG) criteria. Quality of life was measured with European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30/LC13 questionnaires.

RESULTS

One-hundred and sixty patients were included. Pathologically confirmed persistent tumor was present in 53% of patients in the combination arm versus 58% in the radiotherapy alone arm (P=0.5). Median survival in the combination arm was 11.8 [95% confidence interval (CI) 9.3-14.2] months and in the radiotherapy alone arm 11.7 (95% CI 8.1-15.5) months; progression-free survival was not different between arms [6.8 and 7.5 months, respectively (P=0.28)]. Acute toxicity was mild, late toxicity was radiation-induced cardiomyopathy (three patients) and pulmonary fibrosis (five patients). Quality of life was not different between arms, but in all measured patients cough and dyspnea improved, pain became less, and slight paresthesia developed 3 months after treatment.

CONCLUSION

Addition of continuously administered carboplatin as radiosensitizer for locally unresectable NSCLC does not improve local tumor control or overall survival.

Long-term survivors of ovarian malignancies after cisplatin-based chemotherapy

Male germ cell tumour patients treated with cisplatin-based chemotherapy frequently develop cardiovascular risk factors and disease, but sparse information is available about long-term complications of this type of chemotherapy in women. We investigated the prevalence of cardiovascular risk factors and vascular damage in 21 women (median age 39 years; range 26-57 years) with an epithelial or germ cell tumour of the ovary cured by cisplatin-based chemotherapy after a median follow-up of 14 years (range 3-21 years). Hypercholesterolaemia was present in 62%, obesity in 24%, hypertension in 14%, insulin resistance in 14%, and microalbuminuria in 24% of patients. Microalbuminuria was more frequent in long-term cancer survivors than in a female background population with a similar age (23.8 versus 3.2%; P<0.05). A substantial portion of young female patients cured by cisplatin-based chemotherapy are likely to develop cardiovascular risk factors and signs of endothelial damage at an early stage.

Assessment of apoptosis by M30 immunoreactivity and the correlation with morphological criteria in normal colorectal mucosa, adenomas and carcinomas

AIMS

To investigate the monoclonal antibody M30 for the assessment of apoptosis in colorectal tissues. Although Terminal deoxyribonucleotidyl transferase mediated nick end labelling (TUNEL) and in-situ end labelling (ISEL) are the methods most often used to demonstrate and quantify apoptosis in histological tissue sections, the interpretation and specificity of these techniques have been controversial. Immunohistochemistry using the monoclonal antibody M30 that recognizes caspase-cleaved cytokeratin 18 is considered to be a promising alternative but has yet to be validated against a generally accepted standard.

METHODS AND RESULTS

Paraffin sections of normal colonic mucosa (n = 30), normal mucosa obtained from resection margins from carcinomas (n = 30), colorectal adenomas (n = 84) and carcinomas (n = 40) were studied. Apoptosis of epithelial cells was assessed by M30 immunoreactivity and morphological criteria and expressed as a proportion of the total number of cells counted (apoptotic index). Mean apoptotic indices using M30 were 0.18 +/- 0.04% in normal mucosa, 0.42 +/- 0.04% in adenomas and 1.97 +/- 0.24% in carcinomas. Using morphological criteria, these indices were 0.23 +/- 0.03%, 0.62 +/- 0.06% and 1.78 +/- 0.19%, respectively. Apoptotic counts were higher in normal mucosa obtained from resection margins than in genuinely normal mucosa using the M30 antibody. Apoptotic indices obtained by M30 immunoreactivity and morphological criteria were positively correlated (r = 0.71, P < 0.01).

CONCLUSION

Assessment of apoptotic cells by M30 immunoreactivity correlates well with morphological criteria. Apoptotic indices increase in the course of the adenoma-carcinoma sequence. Apoptosis in normal mucosa obtained from resection margins differs from genuinely normal mucosa necessitating caution when interpreting studies of apoptosis in normal colonic mucosa. Our findings support the use of the M30 method in the study of apoptosis in colorectal tissues.

Paclitaxel and carboplatin concurrent with radiotherapy for primary cervical cancer

BACKGROUND

Concurrent radiochemotherapy is currently considered the new standard treatment in locally advanced cervical cancer.

PATIENTS AND METHODS

Eight women with cervical cancer stage IB2-IVA were treated with standard radiation therapy in combination with standard carboplatin (AUC=2, once weekly, x 6) and escalating doses of paclitaxel (60 mg/m2, once weekly, x 4, then x 5 and x 6).

RESULTS

At the lowest dose level, four weekly paclitaxel cycles in six patients, three developed grade III diarrhoea and one severe radiation enteritis several weeks after radiotherapy. Two patients did not achieve complete remission and underwent additive salvage hysterectomy. All patients remained free of local recurrence, but one patient had distant metastases after 13 months. The median disease-free survival was 25 months with a median follow-up of 26 months.

CONCLUSION

Standard pelvic radiotherapy in combination with weekly carboplatin and paclitaxel is poorly tolerated due to dose-limiting diarrhoea.

Successful treatment of metastatic esthesioneuroblastoma

This case report describes a patient with a metastasised olfactorial esthesioneuroblastoma Hyams grade 4 who has been treated with debulking surgery and radiotherapy. After relapse in lymph node, lung and brain, he received additional irradiation and six cycles of carboplatin, vincristine and cyclophosphamide intravenously every three weeks. The patient has now been disease free for 7.8 years. Our data suggest that metastatic esthesioneuroblastoma is sensitive to platinum-based chemotherapy. This patient illustrates that this tumour is very sensitive to platinum-based chemotherapy and that durable complete response can be achieved, even in a metastatic ENB.

Acute and long-term toxicity following radiotherapy alone or in combination with chemotherapy for locally advanced cervical cancer

Randomised studies in locally advanced cervical cancer patients showed that cisplatin should be given concurrently with radiotherapy, because of a better long-term survival compared to radiotherapy alone. This increases the relevance of treatment related toxicity. This review summarises the acute and long-term toxicity of radiotherapy given with or without chemotherapy for cervical cancer. Acute toxicity (all grades) of radiotherapy is reported in 61% of the patients in the rectosigmoid, in 27% as urological, in 27% as skin and in 20% as gynaecological toxicity. Moderate and severe morbidity consists of 5% to 7% gastrointestinal and 1% to 4% genitourinary toxicity. Adding chemotherapy to radiotherapy increases acute haematological toxicity to 5% to 37% of the patients and nausea and vomiting in 12% to 14%. Late effects of radiotherapy include gastrointestinal, urological, female reproductive tract, skeletal and vascular toxicity, secondary malignancies and quality of life issues. For at least 20 years after treatment, new side effects may develop. Gastrointestinal toxicity usually occurs in the first 2 years after treatment in about 10% of the patients. The incidence of moderate and severe urological toxicity can increase up to 10% and rises over time. Gynaecological toxicity usually occurs shortly after treatment while skeletal and vascular toxicity can occur years to decades later. Thus far, no increase in late toxicity has been observed after the addition of cisplatin to radiotherapy. Finally, methods to prevent or decrease late toxicity and therapeutical options are discussed. However, most randomised studies still have a limited follow-up period.

First-line gemcitabine with cisplatin or epirubicin in advanced non-small-cell lung cancer: a phase III trial

The purpose of our study was to compare progression-free survival and quality of life (QOL) after cisplatin–gemcitabine (CG) or epirubicin–gemcitabine (EG) in chemotherapy-naive patients with unresectable non-small-cell lung cancer. Patients (n=240) were randomised to receive gemcitabine 1125 mg m⁻² (days 1 and 8) plus either cisplatin 80 mg m⁻² (day 2) or epirubicin 100 mg m⁻² (day 1) every 3 weeks for a maximum of five cycles. Eligible patients had normal organ functions and Eastern Cooperative Oncology Group performance status ⩽2. QOL was measured with European Organisation for Research and Treatment of Cancer QLQ-C30 and LC13 questionnaires. There were no significant differences in median progression-free survival (CG 26 weeks, EG 23 weeks), median overall survival (CG 43 weeks, EG 36 weeks), or tumour response rates (CG 46%, EG 36%). Toxicity was mainly haematologic. In the EG arm granulocytopenia occurred more frequently, leading to more febrile neutropenia. Also, elevation of serum transaminases, mucositis, fever, and decline in LVEF were more common in the EG arm. In the CG arm, more patients experienced elevated serum creatinine levels, sensory neuropathy, nausea, and vomiting. Global QOL was not different in both arms. Progression-free survival, overall survival, response rate, and QOL were not different between both arms; however, overall toxicity was more severe in the EG arm.

Dysplasia in fundic gland polyps is associated with nuclear beta-catenin expression and relatively high cell turnover rates

BACKGROUND

Fundic gland polyps (FGPs) occur in both syndromic and sporadic form. Syndromic FGPs arise through mutations in the adenomatous polyposis coli (APC) gene, whereas sporadic FGPs are caused by beta-catenin gene mutations. Dysplasia in sporadic FGPs, found less often than in syndromic FGPs, was recently associated with APC rather than beta-catenin mutations. These data suggest different functional consequences of APC and beta-catenin mutations. To investigate this hypothesis, we examined proliferative activity, degree of apoptosis, beta-catenin expression and p53 expression in syndromic and sporadic FGPs.

METHODS

Syndromic FGPs (n = 9) from familial adenomatous polyposis (FAP) patients and sporadic FGPs (n = 18) were studied. Proliferative activity, apoptotic cell death and expression of beta-catenin and p53 were examined by immunohistochemistry. In FGPs containing dysplasia, areas with and without dysplasia were compared.

RESULTS

Syndromic and sporadic FGPs without dysplasia exhibited similar proliferative activity, degree of apoptosis, beta-catenin and p53 expression. Dysplasia was observed more often in syndromic (4/9) than in sporadic FGPs (1/18). Within FGPs containing dysplasia, dysplastic areas showed abnormal nuclear beta-catenin staining in 3/5 cases and higher rates of cell proliferation and apoptosis than non-dysplastic areas. Overexpression of p53 was not observed.

CONCLUSION

The finding of similar rates of proliferation and apoptosis in syndromic and sporadic FGPs does not support the hypothesis that APC and beta-catenin gene mutations have different functional consequences in FGPs. The association of dysplasia with relatively high cell turnover rates and nuclear expression of beta-catenin indicates activation of the Wnt-APC-beta-catenin pathway in dysplasia. The finding of dysplasia in some but not all syndromic FGPs suggests the involvement of other genes in addition to the APC gene in the development of dysplasia in FGPs.

Differential modulation of the TRAIL receptors and the CD95 receptor in colon carcinoma cell lines

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) and CD95 ligand (CD95L) are potent inducers of apoptosis in various tumour cell types. Death receptors DR4 and DR5 can induce and decoy receptors DcR1 and DcR2 can inhibit TRAIL-mediated apoptosis. The study aim was to investigate whether anticancer agents can modulate similarly TRAIL-receptor and CD95 membrane expression and TRAIL and CD95L sensitivity. Three colon carcinoma cell lines (Caco-2, Colo320 and SW948) were treated with 5-fluorouracil (5-FU), cisplatin or interferon-gamma. TRAIL-receptor and CD95 membrane expression was determined flow cytometrically. Sensitivity to TRAIL or CD95L agonistic anti-CD95 antibody was determined with cytotoxicity and apoptosis assays. SW948 showed highest TRAIL sensitivity. The protein synthesis inhibitor cycloheximide decreased FLICE-like inhibitory protein levels in all cell lines, and the TRAIL-resistant cell lines Caco-2 and Colo320 became sensitive for TRAIL. Exposure of the cell lines to 5-FU, cisplatin and interferon-gamma left TRAIL-receptor membrane expression and TRAIL sensitivity unaffected. CD95 membrane expression and anti-CD95 sensitivity was, however, modulated by the same drugs in all lines. Cisplatin and interferon-gamma raised CD95 membrane levels 6-8-fold, interferon-gamma also increased anti-CD95 sensitivity. These results indicate that the CD95 and TRAIL pathways use different mechanisms to respond to various anticancer agents. Induced CD95 membrane upregulation was associated with increased anti-CD95 sensitivity, whereas no upregulation of TRAIL-receptor membrane expression or TRAIL sensitisation could be established. For optimal use of TRAIL-mediated apoptosis for cancer therapy in certain tumours, downregulation of intracellular inhibiting factors may be required.

Neuropsychological investigation into the carcinoid syndrome

RATIONALE

In patients suffering from metastatic carcinoid tumors, chronic disturbances of serotonergic metabolism are frequently present. Serotonin is supposed to influence a range of cognitive functions.

OBJECTIVES

The present study evaluated the cognitive performance of carcinoid patients.

METHODS

In 14 patients with proven carcinoid syndrome, neuropsychological functioning was studied. Visual search, sustained attention, set shifting ability and spatial working memory were assessed using tests from the CANTAB neuropsychological battery. This was compared with the performance of matched healthy controls.

RESULTS

Plasma tryptophan levels were lower than controls. Patients showed an enhanced ability to learn new stimulus-response associations. Sustained visual attention, however, was impaired.

CONCLUSION

Cognitive patterns were different from those found in depressive patients and partly mimicked those found in tryptophan depletion experiments. Further investigation has to point out the role of serotonergic changes in the accomplishment of affective states.

Loss of drug-induced activation of the CD95 apoptotic pathway in a cisplatin-resistant testicular germ cell tumor cell line

Testicular germ cell tumors (TGCTs) are unusually sensitive to cisplatin. In the present study the role of the CD95 death pathway in cisplatin sensitivity of TGCT cells was studied in Tera and its in vitro acquired cisplatin-resistant subclone Tera-CP. Cisplatin induced an increase in CD95 membrane expression, which preceded the onset of apoptosis. Cisplatin-induced apoptosis was efficiently blocked by caspase-8 inhibitor zIETD-fmk in Tera cells, but only partially in Tera-CP cells. In addition, cisplatin induced FADD and caspase-8 recruitment to the CD95 receptor in Tera cells, which was not noticed in Tera-CP cells. Moreover, overexpression of vFLIP reduced apoptosis induction by cisplatin in Tera cells. CD95L-blocking experiments revealed the involvement of CD95/CD95L interactions in cisplatin-induced apoptosis of Tera cells as well as cisplatin-sensitive 833KE TGCT cells. Tera and 833KE cells, treated with low doses of cisplatin, were sensitive for an apoptosis-inducing anti-CD95 antibody. In contrast, CD95L blocking had no effect on cisplatin-induced apoptosis in Tera-CP or Scha, an intrinsic resistant TGCT cell line, nor did anti-CD95 antibody induce additional apoptosis in cisplatin-treated Tera-CP or Scha cells. Taken together, these results show that (1) cisplatin sensitivity of TGCT cells is dependent on the activation of the CD95 death pathway and (2) loss of cisplatin-induced activation of this CD95 signaling pathway may result in resistance to cisplatin.

Outcome in patients with differentiated thyroid cancer with negative diagnostic whole-body scanning and detectable stimulated thyroglobulin

BACKGROUND

Management of patients with differentiated thyroid carcinoma with negative diagnostic radioiodide scanning and increased serum thyroglobulin (Tg) concentrations is a widely debated problem. High-dose iodine-131 treatment of patients who have a negative (131)I diagnostic whole-body scan (WBS) is advocated. However, the therapeutic benefit of this "blind" treatment is not clear.

OBJECTIVE

To investigate the course of serum Tg during thyroid hormone suppression therapy (Tg-on) and clinical outcome in patients with negative diagnostic (131)I scanning and increased serum Tg concentrations during thyroid hormone withdrawal (Tg-off), after treatment with high-dose (131)I.

DESIGN

Retrospective single-center study.

METHODS

Fifty-six patients were treated with a blind therapeutic dose of 150 mCi (131)I. Median follow-up from this treatment until the end of observation was 4.2 Years (range 0.5-13.5 Years).

RESULTS

The post-treatment WBS revealed (131)I uptake in 28 patients, but none in the remaining 28 patients. In this study the Tg-on values did not change after treatment in either the positive or the negative post-treatment WBS group. During follow-up, 18 of the 28 patients with a positive post-treatment WBS achieved complete remission, compared with 10 of the 28 patients with a negative post-treatment WBS. Nine patients in the negative group died, but no patients died in the positive post-treatment group (P=0.001).

CONCLUSIONS

High-dose iodine treatment in diagnostically negative patients who have a negative post-treatment scan seems to confer no additional value for tumor reduction and survival. In patients with a positive post-treatment scan, high-dose iodine treatment can be used as a diagnostic tool to identify tumor location, and a therapeutic effect may be present in individual cases.

Oral mucositis and selective elimination of oral flora in head and neck cancer patients receiving radiotherapy: a double-blind randomised clinical trial

Mucositis is an acute inflammation of the oral mucosa because of radiotherapy and/or chemotherapy. All patients receiving radiotherapy in the head and neck region develop oral mucositis. The aim of this study was to analyse the effects of selective oral flora elimination on radiotherapy-induced oral mucositis, in a double-blind, randomised, placebo-controlled trial. Sixty-five patients with a malignant tumour in the head and neck regions to be treated with primary curative or postoperative radiotherapy participated in this study. The patients received either the active lozenges of 1 g containing polymyxin E 2 mg, tobramycin 1.8 mg and amphotericin B 10 mg (PTA) (33 patients) or the placebo lozenges (32 patients), four times daily during the full course of radiotherapy. Mucositis, changes in the oral flora, quality of feeding and changes of total body weight were assessed. Mucositis score did not differ between the groups during the first 5 weeks of radiotherapy. Nasogastric tube feeding was needed in six patients (19%) of the placebo group and two patients (6%) of the PTA group (P=0.08). Mean weight loss after 5 weeks of radiation was less in the PTA group (1.3 kg) (s.d.: 3.0) than in the placebo group (2.8 kg) (s.d.: 2.9) (P=0.05). Colonisation index of Candida species and Gram-negative bacilli was reduced in the PTA group and not in the placebo group (P<0.05). No effect on other microorganisms was detected. In conclusion, selective oral flora elimination in head and neck irradiation patients does not prevent the development of severe mucositis.

Changes in apoptosis during the development of colorectal cancer: a systematic review of the literature

The development of colorectal cancer is characterised by an accumulation of molecular genetic alterations causing disorders in cell growth, differentiation and apoptosis. Although changes in apoptosis with colorectal cancer development have been studied extensively, a clear consensus of opinion has not yet emerged. In this review, the literature about changes in the frequency and distribution of apoptosis in tissue sections of normal and neoplastic colorectal tissues was reviewed systematically. Using a PUBMED search, 53 relevant articles were identified. Data from these studies are discussed with respect to the following aspects: methods used to detect apoptotic cell death; frequency and locoregional distribution of apoptosis in normal mucosa, adenomas and carcinomas; the correlation between levels of apoptosis and proliferation and the prognostic significance of the degree of apoptosis in colorectal cancer. Possible underlying mechanisms of dysregulation of apoptosis are discussed briefly. Finally, possible therapeutic implications of knowledge of the molecular regulation of apoptosis are discussed and potential options for further research are suggested.

Modulation of death receptor pathways in oncology

Chemotherapeutic efficacy is hampered by occurrence of drug resistance. Several mechanisms cause this phenomenon. A final common factor is the reduced capacity of resistant cells to go into apoptosis following treatment with DNA-damaging agents. It is therefore interesting to search for ways to facilitate this apoptotic process following use of chemotherapeutic drugs. The death receptor ligands tumor necrosis factor (TNF), FasL and TNF-related apoptosis-inducing ligand (TRAIL) might be interesting candidates as they are able to induce apoptosis by binding to their cell membrane receptors. Recombinant forms of these ligands potentiate chemotherapeutic drug effects in preclinical models. For the clinical application of TNF, FasL and TRAIL, it is of primary importance that their safety be guaranteed. RhTNF is the only ligand currently used in humans. However, systemic rhTNF has shown low antitumor activity and higher doses induce severe sepsis-like toxicity. Perfusion setting aimed at limb preservation with rhTNF plus melphalan is currently used in sarcoma patients. A number of options have been tested in the preclinical setting that might allow circumvention of TNF toxicity in the clinic. Systemic rhFasL administration in humans is not yet feasible because of observed severe liver toxicity in mice due to Fas-mediated apoptosis of hepatocytes. Measures to circumvent liver toxicity have not yet been exploited. Another option for using FasL in the clinic may be to identify an alternative route of administration. In the animal model, FasL appeared to be less toxic for the liver compared with anti-Fas antibodies when administered intraperitoneally. There are relatively nontoxic modulators of the Fas death pathway, such as interferon and nonsteroidal antiinflammatory drugs (NSAIDs), which might prove interesting in combination with chemotherapy. Finally, it may be possible to produce a modified FasL with a reduced toxicity profile. TRAIL, produced as soluble, zinc-stabilized rhTRAIL seems to be without preclinical toxicity. Agonistic DR4 and DR5 antibodies against their TRAIL death receptor are being studied as another potential clinical option to induce apoptosis. Due to the synergistic effect observed in the preclinical setting between death receptor ligands and other modulators of the death receptor pathways and chemotherapy, it may well be that this approach is especially of value in the clinic when combined with chemotherapy. Ideally, choices for specific (modified) death receptor ligands for the treatment of patients can be rationally made based on tumor characteristics.