Cathepsin B-independent abrogation of cell death by CA-074-OMe upstream of lysosomal breakdown.
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Amino Acid Chloromethyl Ketones↗
Biomedical subjects
B Szende
Publications and source records attributed to B Szende.
Pharmacological aspects of (-)-deprenyl.
Deprenyl, the selective irreversible inhibitor of monoamine oxidase-B (MAO-B), has been synthesised as a potential antidepressant, however, due to its dopamine potentiating capacity, became a registered drug in the treatment of Parkinson's disease. Deprenyl possesses a wide range of pharmacological activities; some of them are not related to its MAO-B inhibitory potency. Beside its dopamine potentiating effect, it renders protection against a number of dopaminergic, cholinergic and noradrenergic neurotoxins with a complex mechanism of action. By inducing antioxidant enzymes and decreasing the formation of reactive oxygen species, deprenyl is able to combat an oxidative challenge implicated as a common causative factor in neurodegenerative diseases. In a dose substantially lower than required for MAO-B inhibition (10(-9)-10(-13) M), deprenyl interferes with early apoptotic signalling events induced by various kinds of insults in cell cultures of neuroectodermal origin, thus protecting cells from apoptotic death. Deprenyl requires metabolic conversion to a hitherto unidentified metabolite to exert its antiapoptotic effect, which serves to protect the integrity of the mitochondrion by inducing transcriptional and translational changes. Pharmacokinetic and metabolism studies have revealed that deprenyl undergoes intensive first pass metabolism, and its major metabolites also possess pharmacological activities. The ratio of the parent compound and its metabolites reaching the systemic circulation and the brain are highly dependent on the routes of administration. Therefore, in the treatment of neurodegenerative diseases, reconsideration of the dosing schedule, by lowering the dose of deprenyl and choosing the most appropriate route of administration, would diminish undesired adverse effects, with unaltered neuroprotective potency.
Animals↗
Effect of a novel somatostatin analogue combined with cytotoxic drugs on human tumour xenografts and metastasis of B16 melanoma.
A novel somatostatin analogue, TT-232 (which inhibits the proliferation of various cell cultures and transplantable mouse tumours), was examined regarding its effect on human melanoma and lymphoma xenografts as a single treatment or in combination with DTIC (dacarbazine) and etoposide. TT-232 inhibited the growth of HT-18 melanoma xenografts, a dose of 5 mg kg(-1) being the most effective. Combination of 1 mg kg(-1) TT-232 with 30 or 60 mg kg(-1) DTIC (administered daily) resulted in a stronger inhibitory effect compared to TT-232 or DTIC as a single modality. Antimetastatic effect of TT-232 treatment combined with DTIC was studied using the B16 mouse melanoma muscle - lung metastasis model. The number of lung metastases of B16 melanoma could be decreased by the daily administration of 1 mg kg(-1) TT-232 or 60 mg kg(-1), but not of 30 mg kg(-1) DTIC. TT-232, combined with 30 or 60 mg kg(-1) DTIC decreased the lung metastasis number significantly lower than the control. Nearly 50% growth inhibition of HT-58 lymphoma was achieved by daily treatment with 1 mg kg(-1) TT-232. 5 mg kg(-1) etoposide, administered daily, resulted in a similar effect. The combination of 1 mg kg(-1) TT-232 and 5 mg kg(-1) etoposide was significantly more effective than TT-232 or etoposide as a single treatment. The very strong tumour growth inhibitory effect of 10 mg kg(-1) etoposide could even be increased by combination with TT-232. These experimental data suggest that TT-232 may be an effective new tool in the combination chemotherapy of malignant tumours like melanoma and lymphoma.
Animals↗
Malignant myoepithelioma. Clinicopathological and immunohistochemical characteristics.
A malignant myoepithelioma arising in the submucosal accessory glands of the oral cavity of a 23-year-old woman is reported. The patient was very young compared to the cases in the literature, and the tumour had an unusual vestibular location. A false diagnosis of pleomorphic adenoma had been made by fine needle aspiration biopsy. The surgery comprised a wide tumour excision, but neck dissection was not indicated. The final histologic diagnosis was malignant myoepithelioma. Immunohistochemically putative myoepithelial markers were highly expressed.
Actins↗
TT-232: a somatostatin structural derivative as a potent antitumor drug candidate.
TT-232 (D-Phe-Cys-Tyr-D-Trp-Lys-Cys-Thr-NH2) has been developed as an antitumor somatostatin analog. TT-232 has no growth hormone release inhibitory effect and does not inhibit the secretion of gastric acid. This analog induces apoptosis in and exerts pronounced antiproliferative effects on various human tumors (colon, pancreas, lymphoma, leukemia, melanoma, hepatoma) cell lines. The growth of human xenografts (prostate, breast carcinoma, lymphoma, melanoma) and animal tumors (colon-26, P-388, S-180, B16, MXT) was inhibited by TT-232 (dose range: 30-750 microg/kg/day) in 54-98% of cases. Continuous long-term infusion proved to be the most effective way of administration. TT-232 combined with decarbazine or etoposide treatment enhanced the antitumor activity of these drugs on human melanoma and lymphoma xenografts, respectively. Regarding the mode of action, TT-232 activates cell cycle inhibitors via SSTR receptors, inhibits tyrosine kinases through interfering with the proliferative signaling cascades, and interacts with an intracellular receptor and an enzyme involved in glycolysis causing translocation of this enzyme to the nucleus, thus inducing apoptosis. TT-232 may be a promising candidate in the therapy of human malignancies.
Animals↗
Digital slide and virtual microscopy based routine and telepathology evaluation of routine gastrointestinal biopsy specimens.
AIMS: To evaluate a recently developed digital slide and virtual microscope system, and to compare this method with optical microscopy on routine gastrointestinal biopsy specimens in both local and remote access modes. METHODS: A fully computer controlled commercial microscope was used. The scanning program included object detection, autofocus, and image compression algorithms. The overall hard disk space for a gastric biopsy was between 30 and 50 MB and the scanning time was between 20 and 40 minutes. Haematoxylin and eosin stained routine gastric (61) and colon (42) biopsy specimens were selected, scanned, and evaluated by two specialists on an optical (OM) and virtual microscope (VM). RESULTS: The overall concordance of VM and OM with the consensus diagnosis was 95.1% and 97%, respectively. Clinically important concordance was 96.1% and 98% for VM and OM, respectively. The two methods showed concordance in 92% of cases and clinically important concordance in 94.1% of cases. The reasons for discordance were image quality (one case), interpretation difference (three cases), and insufficient clinical information (three cases). Remote evaluation of the digital slides through the Internet has the advantages of the previously used static and dynamic telepathology methods. CONCLUSIONS: Diagnostic concordance was found between OM and VM. The digital slide and the virtual microscope can be alternative techniques in the computerisation of the histology laboratory and in teleconsultation services after further evaluation of time and storage constraints.
Algorithms↗
Pro-apoptotic and anti-apoptotic molecules affecting pathways of signal transduction.
Selective inhibition of the "false" proliferative signals via targeting tyrosine kinases resulting in the induction of apoptosis by depletion of the "survival factors" is one of the most studied and widely accepted concepts of modern chemotherapy. We have synthesized a series of potent tyrosine kinase inhibitors and tested these compounds for apoptosis induction. Some of the tyrosine kinase inhibitors caused either apoptotic or cytoplasmic vacuolar cell death in various tumor cell cultures. The somatostatin analogue oligopeptide TT-232, which indirectly inhibits tyrosine kinases, exerted a dose-dependent apoptosis-inducing effect. The tumor growth-inhibitory effect of TT-232 and some tyrosine kinase inhibitors has also been proven by in vivo experiments, using human tumor xenografts. On the other hand, a dose-dependent pro- or anti-apoptotic activity of (-)-deprenyl has been shown in melanoma cell cultures, the lower doses inhibiting and the higher doses inducing apoptosis. Various metabolites of (-)-deprenyl are responsible for these actions. The effect of (-)-deprenyl is connected with depolarization of mitochondrial membranes. The kinase inhibitors act on the growth factor receptor signaling pathways (survival factor pathways) and initiate the caspase cascade. The key enzyme for the action of both pro-apoptotic and anti-apoptotic compounds is caspase 3.
Animals↗
Changes in apoptotic and mitotic index, bcl2, and p53 expression in rectum carcinomas after short-term cytostatic treatment.
Twenty patients with rectal adenocarcinoma were endoscopically biopsied and given short-term cytostatic therapy [5-fluorouracil (5-FU) (600 mg/m(2)) and Ca-folinate (60 mg/m(2)) for 2 days]. Seven days later, the tumor was resected or a second biopsy was performed. Apoptotic and mitotic indices as well as (mutant) p53 and bcl(2) expression were determined in the tumor tissue before and after the short-term chemotherapy. The patients were treated thereafter with long-term, intermittent 5-FU administration and followed up clinically for 7-26 months. Six patients showed progression of the disease and died, whereas 14 improved or showed no tumor progression. Significant increase of the apoptotic index and nonsignificant decrease of the mitotic index after the short-term cytostatic treatment were seen in the tumor tissue of responder cases. Nonresponders showed no change in both mitotic activity and apoptotic activity. Both survivors and deceased showed high mutant p53 expression, and the changes after short-term 5-FU treatment were not significant. Expression of bcl(2) was present in only 5 cases, with the postchemotherapy changes being not significant. These findings suggest that apoptotic response to short-term cytostatic therapy may be an additional predictive factor in rectal adenocarcinoma.
Aged↗
Apoptosis in prostate carcinomas after short-term treatment with decapeptyl.
Altogether, 40 patients with advanced prostate cancer received the LH-RH analog, Decapeptyl (D), as monotherapy for 1 month. The dose of D was 3.75 mg/month, intramuscularly in microcapsules. Needle biopsy was taken from the prostate of 20 patients at 24 hours, of 10 patients at 7 days, and of 10 patients at 30 days after the injection. The biopsy samples were investigated for mitotic and apoptotic indices as well as expression of p53 and Ki67 in the tumor cells. The effect of the LH-RH analog was manifested in very low and even absent mitotic activity in all points in time. The expression of mutant p53 was high (above 80%) in all 1-day and 7-day samples and in 8 of 10 samples taken 30 days after the start of the therapy. In 2 cases, the ratio of p53-expressing tumor cells was 2% and 5%. At day 30, the previously high ratio of Ki67-positive tumor cells decreased to 2-10% in 8 cases and showed focally higher values (70-90%) in 2 cases. Extremely high (90-100%) apoptosis could be registered in scattered foci of the tumor tissue in all samples taken 1 and 7 days after D injection. The other parts of the tumor tissue showed lower (1-5%) apoptotic activity. At day 30 after the injection, the same phenomenon was observed in 4 cases, but in 6 cases the apoptotic ratio became diffusely low (1-2%). Focal increase of apoptosis observed in the 1- and 7-day samples may be attributed to the direct effect of the LH-RH analog on tumor cells. The findings at day 30 indicate a considerable decrease in proliferating activity and, in the majority of cases, also in apoptotic activity, reflecting the effect of D on the pituitary-gonadal axis.
Aged↗
Antitumor effect of lysine-isopeptides.
Isopeptides (ϵ-peptides) of lysine, with a given Mw and low polydispersity (10-400 units), were synthesized to study the relationship between their chemical structure and biological effect. The designed compounds were of high purity, low polydispersity and high stereochemical purity. The effect of the compounds was tested on a human erythroleukemia cell line (K-562) and on four transplantable mouse tumors (L1210 lymphoid leukemia, P38 macrophage derived tumor, Ehrlich ascites carcinoma, Lewis lung tumor /LLT/). In case of the L1210 and P388 tumors and the Ehrlich carcinoma, survival of the animals was used as an indicator of the effect. In case of the Lewis lung tumor, the number and size of metastases in the lung and/or liver of treated and untreated mice were used as indicators. The polymers of polymerisation degree 80-120 (Mw 10.2-15.4 KD) showed the strongest antiproliferative effect both on K562 cells and the tumors growing in vivo. This effect was manifest with a significantly higher survival rate as compared to the control (L1210, P38, Ehrlich ascites), furthermore, by a decrease in the number and size of liver and lung metastases (LLT).
Journal Article↗
Changes in apoptosis, mitosis, Her-2, p53 and Bcl2 expression in breast carcinomas after short-term tamoxifen treatment.
The short-term (7 days) effect of tamoxifen on apoptosis and mitosis index, p53, Bcl2 and Her-2/neu/c-erb2 expression in invasive ductal mammary carcinoma was studied histologically in the diagnostic biopsy and surgically removed tumor tissue of 10 patients. Following tamoxifen treatment expression of HER-2 and p53 decreased but Bcl2 remained unchanged. Mitotic activity decreased slightly, but not significantly. Apoptotic activity increased in six cases in the second sample compared to the values measured of the first biopsy. These changes may be attributed to the effect of antiestrogen therapy.
Antineoplastic Agents, Hormonal↗
[The role of perisinusoidal (Ito) cells in the course of hepatocellular carcinoma: light and electron microscopic data to the pathogenesis of hepatocellular carcinoma].
The clinical history of a 49 year old female patient suggested a multifocal, rapidly progressive liver disease of one month duration, apparently due to metastatic tumour. An open needle biopsy of the liver revealed a primary hepatocellular carcinoma of low grade malignancy; the diagnosis was confirmed by histological, immunohistochemical and electron microscopic studies. Besides the ultrastructural examination of the liver biopsy disclosed an unusually marked proliferation of perisinusoidal (Ito)-cells. The authors assume that the myofibroblast proliferation and transformation of Ito-cells in the noncirrhotic liver led to the formation of multifocal areas. The perisinusoidal cell proliferation was presumably due to vitamin A intoxication caused by an extreme vegetarian diet (daily consumption of large amounts of carrot juice for years, as disclosed by a retrospectively obtained history). It is assumed that the vitamin A abuse, and perisinusoidal cell proliferation may have promoted the unusually rapid progression of the multifocal, but histologically low grade hepatocellular tumour. Spectacular clinical improvement could be observed after chemotherapy, combined with local hyperthermic treatment. Presumably, the change in diet (cessation of excessive retinol and carotene intake) also may have had a beneficial effect. After one year the clinical course suggests a slower progression of tumour growth which would be more in keeping with the prognosis based on the histologic appearance of the low grade hepatocellular carcinoma. This patient's case illustrates the importance of electron microscopy supplementing diagnostic histological and immunohistochemical examinations.
Carcinoma, Hepatocellular↗
Repeated biopsies in evaluation of therapeutic effects in prostate carcinoma.
BACKGROUND: Apoptosis is one of the major events following total androgen blockade (TAB). The aim of this study was to determine the predictive value of some histological parameters including apoptosis and gene products which influence apoptosis, based on repeated biopsies taken from the same patients. METHODS: At the time of diagnosis by needle biopsy TNM stage, serum PSA, Gleason's grade, apoptotic and mitotic index, Ki67, p53, and bcl(2) expression were investigated in 60 prostate carcinoma patients. Antiandrogen therapy supplemented with surgical or chemical castration was administered. Serum PSA-test and needle biopsy were repeated 13-14 weeks after starting the therapy, simultaneously with determination of the apoptotic and mitotic index, Ki67, p53, and bcl(2) expression. RESULTS: Forty-seven patients were alive at the end of the study, 13 patients died. Decrease in mitotic, increase in apoptotic index predicted favourable long-term response to antiandrogen therapy. Lower Ki67 and (mutant) p53 expression in the first and also in the second biopsy pointed to favourable effect of antiandrogen treatment. Since the ratio between Ki67 and apoptotic index strongly decreased in the survivors upon therapy, changes in Ki67/apoptosis ratio is recommended as a histologically detectable predictive factor. bcl(2) expression did not show significant correlation with the outcome of the disease. CONCLUSIONS: Histological evaluation of mitotic and apoptotic index, Ki67, and p53 expression in repeated biopsies contributes to predicting the value of the actual treatment and may be useful to institute alterations in therapy.
Age Factors↗
Induction of apoptosis in MDR1 expressing cells by daunorubicin with combinations of suboptimal concentrations of P-glycoprotein modulators.
The application of most agents with the capacity to reverse multidrug resistance (MDR) via modulation of the multidrug transporter P-glycoprotein (Pgp) was shown to be associated with toxic side-effects. For this reason, we have investigated the effect of combinations of suboptimal concentrations of Pgp blockers on the induction of apoptosis and growth arrest in daunorubicin (D) treated, MDR1 gene transfected cells. We used verapamil, PSC833 and Cremophor EL as Pgp modulators, which affect the function of Pgp by different mechanisms. Treatment of NIH3T3/MDR1 cells with combinations of suboptimal concentrations of Pgp modulators in the presence of D caused apoptosis and G(2) arrest to the same extent as optimal concentrations of singly used blockers. We conclude that combinations of suboptimal concentrations of Pgp modulators may cause effective sensitization of resistant tumor cells, and at the same time, may avoid the frequently observed toxic effects experienced in clinical trials with a single modifier applied at the optimal dose.
3T3 Cells↗
[Ferenc Keresztúry: from student at Sárospatak Russian medical professor (1735-1811)].
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Anatomy↗
Renal tubular cell necrosis and apoptosis in transplanted kidneys.
Renal wedge biopsies were taken from donors' kidneys immediately at the end of cold ischaemia and 30 min after transplantation in 11 cases. Five renal grafts showed immediate and six showed delayed renal function clinically. The ratio of apoptotic and necrotic renal tubular cells and Ki67 activity was determined in both biopsies. Necrotic and apoptotic as well as proliferating renal tubular cells were seen in all samples. Both apoptotic and proliferative activity was decreased in samples taken 30 min after transplantation in cases of immediate renal function compared to the samples taken before transplantation. This phenomenon was not observed in cases of delayed renal function.
Apoptosis↗
Apoptotic and mitotic activity in squamous cell carcinoma cells after combined modality treatment with gamma-irradiation and dibromodulcitol.
A-431 squamous cell carcinoma cells were treated in vitro with either 4 Gy radiation of 15 (or 45) microg/ml dibromodulcitol (DBD), as well as with combined 4 Gy irradiation and DBD, with the latter as either a pretreatment or post-treatment. DBD alone or in combination with radiation had a greater effect on cell proliferation than the effect of radiation alone. The difference is due to a higher level of apoptosis induced by DBD, especially in conjunction with radiation. Such a combination may therefore be useful in the treatment of squamous cell carcinoma, which in general responds poorly to radiation therapy.
Antineoplastic Agents, Alkylating↗
Anti-apoptotic and apoptotic action of (-)-deprenyl and its metabolites.
The mode of cytoprotective action of the monoamine oxydase B inhibitor (-)-deprenyl was studied using A-2058 human melanoma cells in culture. Serum deprivation caused apoptosis of the cultured cells, which could be decreased by administration of 10(-9) - 10(-13)M (-)-deprenyl. The known metabolites of (-)-deprenyl, (-)-desmethyl-deprenyl, (-)- and (+)-methylamphetamine failed to exert the same effect. The anti-apoptotic activity of (-)-deprenyl was prevented by the simultaneous application of the microsomal drug-metabolizing enzyme inhibitor SKF-525A. These results show that (-)-deprenyl needs metabolic conversion in order to be anti-apoptotic, but the effective metabolite is still unknown. On the other hand, higher dose (10(-13)M) of (-)-deprenyl, (-)-desmethyl-deprenyl, (-)- and (+)-methylamphetamine induced apoptosis in the non-serum-deprived A-2058 cell culture. SKF-525A did not prevent the apoptosis-inducing effect of (-)-deprenyl, which means that no metabolic changes are needed for this activity. High dose (10(-3)M) of (-)-deprenyl induced very high Caspase 3 activity in non-serum-deprived A-2058 cell culture, low doses (10(-9) - 10(-3) M) of (-)-deprenyl maintained Caspase 3 activity on control level in case of serum-deprivation.
Adrenergic Agents↗