Albert Geldof

Followers

Following

Co-authors

Public Views

Interests

Uploads

Papers by Albert Geldof

Progression delay of prostate tumor skeletal metastasis effects by bisphosphonates. J Urol 148: 1270-1273

The Journal of Urology

Prostate tumor cell metastasis to the axial skeleton was induced in male Copenhagen rats using th... more Prostate tumor cell metastasis to the axial skeleton was induced in male Copenhagen rats using the intravenous injection of syngeneic metastatic R3327-MATLyLu tumor cells and concomitant caval vein clamping. The proliferation of tumor cells in the lumbar region was monitored by the progression, within 19 days post tumor cell injection, of hindleg paralysis which appeared in these animals. Histology confirmed the presence of tumor cells within the lumbar spine in 100% of cases displaying hindleg paralysis. Treatment with either of the bisphosphonate drugs, Cl2MDP or APD, suppressed and delayed the development of hind leg paralysis. Bisphosphonate treatment may be expected to delay the onset of axial skeletal metastasis effects in prostate cancer patients.

Inhibition of β-hydroxys-teroid-dehydrogenase: an approach for prostate cancer treatment

Anticancer research

ABSTRACT

Histopathological changes in rat pancreas after fasting and cassava feeding

In vivo (Athens, Greece)

Histopathological changes in rat pancreas were induced by cyclic periods of experimental malnutri... more Histopathological changes in rat pancreas were induced by cyclic periods of experimental malnutrition or by cassava (manioc) feeding for 11 weeks. Decline of body weight was correlated with decrease in testicular fat pad weight as a measure of body fat stores. A marked decrease in pancreatic weight in the cassava-fed group was correlated with shrinkage of acinar structures and degenerative features in exocrine pancreas. In the malnutrition group vacuolisation and loss of tissue architecture were observed in some parts of the organ. No signs of ductal obstruction as a tentative cause of pancreatic pathology after malnutrition could be detected. Loss of islets tissue was occasionally seen in degenerative areas. It is concluded that histopathological changes in exocrine pancreas result from malnutrition and cassava feeding differentially and precede ultimate degenerative processes of pancreas endocrine tissue. Tropical malnutrition type diabetes and low protein related diabetes may in their etiology be different entities, but may coincide in practice and aggravate each other to yield severe and irreversible morbidity.

Response of PC-3 prostate cancer cells to combination therapy using irradiation with glucocorticoids or doxorubicin

Anticancer research

We evaluated the effects of irradiation, doxorubicin and dexamethasone on human PC-3 prostate can... more We evaluated the effects of irradiation, doxorubicin and dexamethasone on human PC-3 prostate cancer cells, investigating whether dexamethasone and doxorubicin can alter the irradiation cytotoxicity of PC-3 cells. We used the human PC-3 prostate cancer cells, analyzing cell growth with trypan blue exclusion, indices of the cell cycle with flow cytometry and apoptosis with flow cytometry and analysis of DNA fragmentation on simple agarose gel. Doxorubicin (100 nM) arrested cell cycle at the G2/M phase, decreased cell growth and produced apoptosis of PC-3 cells in a time-dependent manner. Dexamethasone (100 nM) increased the distribution of PC-3 cells at G0/G1 phase in the cell cycle, exerting an inhibitory effect on the proliferation of PC-3 cells after 48 and 72 hr, but it did not produce apoptosis. Irradiation (4 Gy) initially arrested cells at the G2/M phase in the cell cycle (24 hr) which was gradually overcome and the PC-3 cells were shifted into G0/G1 phase or apoptosis after 48 and 72 hr. Irradiation decreased the PC-3 cell growth by 40-50% after 48 and 72 hr, respectively. Treatment with doxorubicin (100 nM) for 24, 48, and 72 hr after irradiation potentiated irradiation cytotoxicity of PC-3 cells. Dexamethasone treatment 24 hr before and 24, 48 and 72 hr after irradiation increased the number of surviving PC-3 cells and partially neutralized the irradiation effects on cell cycle. Doxorubicin potentiated while dexamethasone partially reversed the irradiation cytotoxicity of PC-3 cells. These data may be of clinical importance for the treatment of hormone refractory prostate cancer.

Molecular imaging of aurora kinase A (AURKA) expression: synthesis and preclinical evaluation of radiolabeled alisertib (MLN8237)

Nuclear Medicine and Biology, 2015

Survival of patients after resection of colorectal cancer liver metastasis (CRCLM) is 36%-58%. Po... more Survival of patients after resection of colorectal cancer liver metastasis (CRCLM) is 36%-58%. Positron emission tomography (PET) tracers, imaging the expression of prognostic biomarkers, may contribute to assign appropriate management to individual patients. Aurora kinase A (AURKA) expression is associated with survival of patients after CRCLM resection. We synthesized [(3)H]alisertib and [(11)C]alisertib, starting from [(3)H]methyl nosylate and [(11)C]methyl iodide, respectively. We measured in vitro uptake of [(3)H]alisertib in cancer cells with high (Caco2), moderate (A431, HCT116, SW480) and low (MKN45) AURKA expression, before and after siRNA-mediated AURKA downmodulation, as well as after inhibition of P-glycoprotein (P-gp) activity. We measured in vivo uptake and biodistribution of [(11)C]alisertib in nude mice, xenografted with A431, HCT116 or MKN45 cells, or P-gp knockout mice. [(3)H]Alisertib was synthesized with an overall yield of 42% and [(11)C]alisertib with an overall yield of 23%±9% (radiochemical purity ≥99%). Uptake of [(3)H]alisertib in Caco2 cells was higher than in A431 cells (P=.02) and higher than in SW480, HCT116 and MKN45 cells (P&lt;.01). Uptake in A431 cells was higher than in SW480, HCT116 and MKN45 cells (P&lt;.01). Downmodulation of AURKA expression reduced [(3)H]alisertib uptake in Caco2 cells (P&lt;.01). P-gp inhibition increased [(3)H]alisertib uptake in Caco2 (P&lt;.01) and MKN45 (P&lt;.01) cells. In vivo stability of [(11)C]alisertib 90min post-injection was 94.7%±1.3% and tumor-to-background ratios were 2.3±0.8 (A431), 1.6±0.5 (HCT116) and 1.9±0.5 (MKN45). In brains of P-gp knockout mice [(11)C]alisertib uptake was increased compared to uptake in wild-type mice (P&lt;.01) CONCLUSIONS: Radiolabeled alisertib can be synthesized and may have potential for the imaging of AURKA, particularly when AURKA expression is high. However, the exact mechanisms underlying alisertib accumulation need further investigation. Radiolabeled alisertib may be used for non-invasively measuring AURKA protein expression and to stratify patients for treatment accordingly.

Mastbergen SC, Duivenvoorden I, Versteegh RT, Geldof AACell cycle arrest and clonogenic tumor cell kill by divergent chemotherapeutic drugs. Anticancer Res 20: 1833-1838

Anticancer research

Regulators of cell cycle phase transitions could be important targets for cancer treatment using ... more Regulators of cell cycle phase transitions could be important targets for cancer treatment using cytostatic chemotherapy. Therefore, the extent of cell cycle arrest induced by different cytostatic agents has to be correlated with ultimate clonogenic tumor cell death. Especially the value of early cell cycle perturbations as indicators for the clinical efficacy of drugs should be a matter of investigation. In vitro PC-3 human prostate carcinoma cells were incubated for 24 hours with a panel of six different chemotherapeutic drugs in various concentrations (Aplidine, Cisplatin, Isohomohalichondrin B (IHB), Taxol, Vincristine and Vinorelbine). The short term effects on the cell cycle distribution were determined by DNA flowcytometry while the clonogenic capacity of these cells was quantitated to measure the cytotoxic treatment efficacy. Significant decreases of clonogenic survival proved to be strongly correlated with cell cycle perturbations. IHB, Taxol, Vincristine and Vinorelbine re...

Combination 186Re-HEDP and cisplatin supra-additive treatment effects in prostate cancer cells. J Nucl Med

Journal of Nuclear Medicine

Radionuclide therapy has proven to be an efficacious palliative treatment for metastatic prostate... more Radionuclide therapy has proven to be an efficacious palliative treatment for metastatic prostate cancer. Its potential therapeutic possibilities may be substantially increased by combining it with effective radiosensitizing drugs. This study explores the radiosensitizing properties of cisplatin when combined with 186Re-labeled hydroxyethylidene diphosphonate (HEDP) in the treatment of R3327-MATLyLu prostate cancer cells in vitro. A concomitant incubation during 4 d, combining various concentrations of cisplatin (0, 0.42, 0.83 and 1.67 micromol/L) and 186Re-HEDP (0, 1.84 and 3.69 MBq/mL [0, 50 and 100 microCi/mL, respectively]) was followed by the determination of the cell numbers surviving and the replating of these cells in semisolid agar. The surviving fraction of clonogenic tumor cells after combination treatment clearly showed synergism when analyzed by a panel of three different published analytical methods. In addition, analysis of variance demonstrated a significant interact...

format_quotePreliminary clinical data indicate enhanced treatment response with radiopharmaceuticals and cisplatin for hormone escape metastatic prostate cancer.format_quote

Download

Serum testosterone plays an important role in the metastatic ability of castration resistant prostate cancer

by Albert Geldof, John Jacobs, E. Meuleman, and André Vis

World Journal of Urology

PURPOSE: Prostate cells are dependent on androgens for growth and proliferation. Androgen depriva... more PURPOSE: Prostate cells are dependent on androgens for growth and proliferation. Androgen deprivation therapy is the recommended treatment for advanced/metastatic prostate cancer. Under this therapy, prostate cancer will inevitably progress to castration resistant prostate cancer (CRPC). Despite putative castration resistance, testosterone might still play a crucial role in the progression of CRPC. The goal of this study was to determine the role of testosterone in the formation of metastases of CRPC in both in vitro and in vivo settings. METHODS: In vitro, the effect of testosterone and the non-aromatizable androgen methyltrienolone on migration, invasion and proliferation of a castration-resistant prostate cancer rat cell line (Dunning R3327-MATLyLu) was assessed using a transwell assay and a sulforhodamine B assay and immunohistochemical detection of ki67. Androgen receptor status was determined using Western blot. In vivo, Copenhagen rats were divided in four groups (males, fema...

Download

Development of an in vitro model to measure bioactivity of botulinum neurotoxin A in rat bladder muscle strips

by Albert Geldof and E. Meuleman

BMC Urology

Background Botulinum toxin A (BoNT-A) is a new treatment modality in various causes of bladder dy... more Background Botulinum toxin A (BoNT-A) is a new treatment modality in various causes of bladder dysfunction; like neurogenic detrusor overactivity and overactive bladder. The best technique of administrating BoNT-A in patients is unknown. A validated in vitro model could be used to investigate newer intravesical administration techniques of BoNT-A. In this study, we describe the development and validation of in vitro model to measure inhibitory effects of BoNT-A on bladder strip contractions. Methods Rat bladder strips were mounted in organ baths filled with Krebs’ solution. The strips were stimulated chemically (80 mM potassium chloride, 1 μM carbachol) and electrically (Electrical Field Stimulation (EFS) 100 shocks, 50 V, 20 Hz, every 3 minutes). The viability of the strips was measured by carbachol stimulation at the beginning and at the end of the experiments. The strips were incubated in various concentrations of BoNT-A (0.03, 0.2, 0.3 nM). Controls were incubated in Krebs’ solu...

Download

Abstract 112: Synthesis and preclinical evaluation of radiolabeled alisertib as an investigational aurora kinase A PET tracer

Cancer Research, 2014

Eiwitten in urine-exosomen identificeren patiënten met gemetastaseerd prostaatkanker

Tijdschrift voor Urologie, 2012

Download

The ultimate radiochemical nightmare: upon radio-iodination of Botulinum neurotoxin A, the introduced iodine atom itself seems to be fatal for the bioactivity of this macromolecule

by Albert Geldof and E. Meuleman

EJNMMI research, 2015

Botulinum neurotoxin A (BoNT-A) is a highly neurotoxic drug and frequently used in patients. Know... more Botulinum neurotoxin A (BoNT-A) is a highly neurotoxic drug and frequently used in patients. Knowledge on the optimal way of administration of BoNT-A and its subsequent distribution is still rather limited. An accurate method for monitoring these processes might be the use of radiolabelled BoNT-A. In this paper, we report our feasibility study on labelling BoNT-A with high-dose iodine-125 ((125)I) via IODOGEN-coated BoNT-A method. Using cetuximab as model substrate for BoNT-A, a miniaturization of the IODOGEN-coated mAb method was developed with special attention to the minimum required amount of the oxidant IODOGEN, while the amount of substrate, reaction volume and reaction time were downsized. Labelling efficiency and radiochemical purity were determined by TLC, integrity by SDS-PAGE and HPLC and immunoreactivity by cell-binding assay. BoNT-A (50 μg) was labelled with (125)I by coating with 2.5 μg IODOGEN, in a total reaction volume of 250 μL and a reaction time of 90 s. (125)I-B...

format_quoteLabelling cetuximab with 125 I resulted in 70%-80% efficiency and >99% radiochemical purity; conditions impacted efficiency.format_quote

Download

Characterization of and protection from neurotoxicity induced by oxaliplatin, bortezomib and epothilone-B

by Abolfazl Avan, Albert Geldof, Amir Avan, and Godefridus J Peters

Anticancer research, 2014

To characterize neurotoxicity induced by oxaliplatin, bortezomib, and epothilone-B as well as pro... more To characterize neurotoxicity induced by oxaliplatin, bortezomib, and epothilone-B as well as protection against their neurotoxicity using an in vitro model. Neurotoxicity was evaluated using the neurite outgrowth method in PC12 rat pheochromo-cytoma cells differentiated towards a mature neuronal phenotype, while neuroprotection was explored by simultaneous exposure to 0.5 mM amifostine. The potential markers of neuronal differentiation, cyclin-B2 (Ccnb2) and baculoviral inhibitor of apoptosis repeat-containing 5 (Birc5), were evaluated by quantitative reverse transcription polymerase chain reaction (RT-PCR). Bortezomib, epothilone-B, and oxaliplatin reduced neurite length to 68%, 78% and 66%, respectively (p<0.05). The percentage of neurite-forming-cells (discriminating neurotoxicity from general cytotoxicity) decreased from 70% (control) to 55% (bortezomib), 46% (epothilone-B), and 51% (oxaliplatin). Amifostine was neuroprotective against oxaliplatin-induced neurotoxicity, incr...

Download

ABCC4 Decreases docetaxel and not cabazitaxel efficacy in prostate cancer cells in vitro

Anticancer research, 2013

This study aimed to investigate cabazitaxel efficacy in a model for docetaxel-resistant prostate ... more This study aimed to investigate cabazitaxel efficacy in a model for docetaxel-resistant prostate cancer cells and to evaluate the involvement of ATP-cassette binding protein 4 (ABCC4) with regard to multidrug resistance. Docetaxel and cabazitaxel sensitivity was measured in PC3 and R3327-MATLyLu (MLL) cell lines, using the sulforhodamine B (SRB) assay. ABCC4 expression was examined by western blotting and its functional involvement in drug sensitivity by blocking with MK571 inhibitor. The docetaxel-resistant MLL cells (4.5-fold compared to cabazitaxel; p<0.001) were shown to express high levels of ABCC4, while non-resistant PC3 cells had no detectable ABCC4 expression. Functional inhibition of ABCC4 in MLL cells resulted in a two-fold decrease in effective concentration of docetaxel and had no effect on toxicity of cabazitaxel. Cabazitaxel showed an improved therapeutic efficacy over docetaxel in ABCC4-expressing prostate cancer cells. ABCC4 appears to be an important determinant...

Download

A predictive role for noncancerous prostate cells: low connexin-26 expression in radical prostatectomy tissues predicts metastasis

by Albert Geldof and L. Rozendaal

British journal of cancer, Jan 4, 2012

It is important to identify markers that predict whether prostate cancer will metastasise. The ad... more It is important to identify markers that predict whether prostate cancer will metastasise. The adjacent noncancerous cells (influenced by the tumour cells) may also express potential markers. The objective of this study was to determine the influence of cancer cells on noncancerous cells and to assess the value of the cell-communication protein connexin-26 (Cx26) as a marker to predict the development of metastasis. The effect of conditioned medium (CM) from PrCa cells on in vitro noncancerous cell proliferation, migration and invasion and Cx26 expression was determined. Connexin-26 expression was investigated in prostatectomy tissues from 51 PrCa patients by immunohistochemistry and compared with various clinicopathological parameters. Proliferation, migration and invasion of noncancerous cells were influenced by CM from the PrCa cell lines. Importantly, a clear relation was found between low Cx26 expression in the noncancerous tissue in prostatectomy sections and the risk of devel...

Download

Amifostine protects against chemotherapy-induced neurotoxicity: an in vitro investigation

Anticancer research

Peripheral neurotoxicity is a dose-limiting side-effect of a number of effective chemotherapeutic... more Peripheral neurotoxicity is a dose-limiting side-effect of a number of effective chemotherapeutic agents. Neuroprotective agents may help to reduce neurotoxicity, thus allowing the intensification of cytostatic therapy in patients. In this in vitro study, using the rat pheochromocytoma cell line PC-12 neurite-outgrowth assay, the potential of amifostine to protect against cisplatin-, paclitaxel- and vincristine-induced neurotoxicity was investigated Amifostine is described as selectively protecting normal tissue and not tumour tissue. The effect of amifostine on tumour cell kill was investigated using the XTT and colony forming assay. Paclitaxel and vincristine both caused a significant reduction in the percentage of cells expressing neurites. Co-incubation with amifostine significantly increased this percentage of neurites in paclitaxel-induced neurotoxicity, but not in vincristine-induced neurotoxicity. Post-incubation of amifostine also proved to partly reverse already existing c...

Download

In vitro protection from cisplatin-induced neurotoxicity by amifostine and its metabolite WR1065

Journal of neuro-oncology, 1999

Cisplatin-induced neuropathy is a major dose-limiting toxicity. Counteraction by amifostine and i... more Cisplatin-induced neuropathy is a major dose-limiting toxicity. Counteraction by amifostine and its metabolite WR1065 may reduce peripheral neurotoxicity in a number of patients. Using the nerve growth factor (NGF)-dependent neurite outgrowth from the PC12 pheochromocytoma cell line as an in vitro assay for neurotoxicity, the protective effects of amifostine and WR1065 against cisplatin action on neurite formation by PC12 cells were studied. Cisplatin in a concentration of 10 microg/ml significantly decreased the percentage of neurite forming cells from 84% to 40%. Amifostine in doses of 0.4 and 0.8 mM proved to protect significantly against the cisplatin-induced decrease in neurite formation, when co-incubated with cisplatin. Also the metabolite WR1065 protected significantly against cisplatin neurotoxicity in a dose of 0.12 mM. Our results show a significant protection by amifostine and its main metabolite WR1065 against cisplatin-induced neurotoxicity using an in vitro model.

Download

Synergism between cisplatin and radiotherapy in an in vitro prostate tumor cell line

Anticancer research

A combination of local irradiation and systemic cytotoxic treatment could improve therapeutic eff... more A combination of local irradiation and systemic cytotoxic treatment could improve therapeutic efficacy in metastatic prostate cancer. Radiosensitization can augment the treatment response to standard doses of radiation or enable lower treatment doses to be given; thus decreasing possible side effects. Intracellular glutathione has been implicated in the mechanism of such radio- sensitizing effects. In the present study, R3327-MATLyLu prostate tumor cells were treated with cisplatin (0.0325 microM, 0.1625 microM, 0.325 microM and control "0 microM") in combination with irradiation (2, 4, 6, 8 Gy and control "0 Gy"). The survival of clonogenic tumor cells in agar was determined. In another experiment the irradiation was carried out after a 3 hours pretreatment with cisplatin concentrations (1.63 microM, 3.25 microM, 6.5 microM and control "0 microM") both in the presence and absence of Glutathione. In both experimental conditions the combination of cispla...

Vinca-alkaloid neurotoxicity measured using an in vitro model

Journal of neuro-oncology, 1998

Neurotoxicity forms a major limitation in many clinical applications of vincristine and other pow... more Neurotoxicity forms a major limitation in many clinical applications of vincristine and other powerful vinca alkaloid anticancer drugs. Using the nerve growth factor (NGF) dependent neurite outgrowth from the PC12 pheochromocytoma cell line as an in vitro assay for neurotoxicity, the effect of different concentrations of vincristine (0.55; 1.1 and 11 nM) was compared with that of vindesine and vinblastine. Vincristine in comparatively low concentration (0.55 nM) could significantly decrease the percentage of neurite forming cells from 74% to 32% within a three day incubation period. Especially the longer neurites (> 2 x cell body) proved to be extremely sensitive for vincristine effects. Vinblastine and vindesine were also able to decrease, dose dependently and significantly, the percentage of neurite forming cells. However, the effects observed were less severe than that of vincristine. The sequentially increasing level of neurotoxicity due to vinblastine, vindesine and vincrist...

Download

Exosomal ITGA3 interferes with non-cancerous prostate cell functions and is increased in urine exosomes of metastatic prostate cancer patients

by Albert Geldof and Mehrdad Lavaei

Journal of Extracellular Vesicles, 2013

Background: Cancer cells are able to change the protein expression and behavior of non-cancerous ... more Background: Cancer cells are able to change the protein expression and behavior of non-cancerous surrounding cells. Exosomes, secreted by prostate cancer (PCa) cells, may have a functional role in cancer metastasis and present a promising source for protein biomarkers. The aim of the present study was to identify which proteins in exosomes can influence non-cancerous cells, and to determine whether we can use urine exosomal proteins to identify high-risk PCa patients. Method: Exosomes were isolated by ultracentrifugation. Migration and invasion were studied by the transwell (invasion) assay. Proteomics was performed by LC-MS/MS and identified proteins were validated by Western blotting. Cellular uptake of fluorescent labeled PKH67-exosomes was measured by FACS. Results: Based on comparative protein profiling by mass spectrometry-based proteomics of LNCaP-and PC3-exosomes, we selected ITGA3 and ITGB1, involved in migration/invasion, for further analyses. Inhibition of exosomal ITGA3 reduced the migration and invasion of non-cancerous prostate epithelial cells (prEC) almost completely. Cellular uptake of exosomes by prEC was higher with PC3-exosomes compared to LNCaP exosomes. Finally, ITGA3 and ITGB1 were more abundant in urine exosomes of metastatic patients (p B0.05), compared to benign prostate hyperplasia or PCa. Conclusion: These data indicate exosomal ITGA3 and ITGB1 may play a role in manipulating non-cancerous surrounding cells and that measurement of ITGA3 and ITGB1 in urine exosomes has the potential to identify patients with metastatic PCa in a non-invasive manner.

format_quoteExosomal ITGA3 and ITGB1 could identify metastatic PCa through non-invasive urine tests, indicating their potential as biomarkers.format_quote

Download

Albert Geldof

Uploads

Papers by Albert Geldof

Log In