Electronic Library of Scientific Literature


Volume 46 / No. 4 / 1999


Diazenes: modificators of tumor cell resistance to cisplatin

M. Osmak, T. Bordukalo, J. Koąmrlj, M. Kvajo, Z. Marijanović, D. Eljuga, S. Polanc

Department of Molecular Genetics, Ruđer Boąković Institute, 10 000 Zagreb, Croatia;
Faculty of Natural Sciences, University of Zagreb, Croatia;
Faculty of Chemistry and Chemical Technology, Ljubljana, Slovenia;
Department of Gynecology, University Hospital for Tumors, Zagreb, Croatia

Most studies indicate that modulation of glutathione metabolism may be one of the most promissing means of reversing clinical drug resistance. Five new diazene compounds have been synthesized: JK-279, JK-835, JK-913, JK-925 and LV-57 that should, according to their structure and biochemical properties, lower the GSH concentration. In the present study, we examined the influence of diazenes on cisplatin resistance in human cervical (HeLa) and laryngeal carcinoma (HEp2) cells as well as in their cisplatin-resistant sublines (HeLaCA and CK2, respectively). Intracellular GSH content was examined spectrophotometrically by the procedure developed by Tietze. The cell sensitivity to drugs was determined using a modified colorimetric MTT assay. Results show that all examined diazenes lowered GSH concentration. This decrease was insignificant for JK-835 and JK-925 in HeLa and HeLaCA cells, and JK-925 in CK2 cells. In human cervical carcinoma HeLa and HeLaCA cells, JK-279 was mostly active in sensitizing the cells to cisplatin, especially in drug-resistant cells. JK-913, JK-835 and LV-57 reverted partially resistance to cisplatin in HEp2 cells, while none of the diazenes was active in CK2 cells. In conclusion, diazene JK-279 may be useful in the combined treatment (cisplatin + diazene) for the certain type of cancer.

Key words: Drug resistance, diazenes, tumor cells, glutathione, cisplatin.
NEOPLASMA, 46, 4, 1999, pp. 201-206

Achiral and chiral HPLC analysis of norverapamil and its metabolites in microsomal samples

E.Brandąteterová, I.W.Wainer, T.Tracy

Department of Analytical Chemistry, Slovak Technical University, Radlinského 9, 812 37 Bratislava, Slovak Republic;
School of Medicine, Georgetown University, Washington D.C., USA;
VWU School of Pharmacy, Morgantown, USA

Achiral and chiral HPLC (high performance liquid chromatography) were developed for monitoring norverapamil and its two metabolites in in vitro microsomal samples. Norverapamil is a chiral drug with the same ability as verapamil in reversing MDR (multi-drug resistance) against some cytostatics. R(+) norverapamil is less cardiotoxic as S(-) enantiomer and so it could be applied in higher concentrations.
HPLC conditions were worked out for both achiral and chiral assays and very simple and effective preseparation procedure (SPE - solid phase extraction) was used for microsomal sample as clean-up step before HPLC analysis.
The total concentrations of norverapamil and its metabolites were calculated from achiral chromatograms and the ratio of enantiomers were determined from chiral separations. The complete assay could be used for both in vitro and in vivo experiments.

Key words: Norverapamil, achiral HPLC, chiral HPLC, microsomal samples.
NEOPLASMA, 46, 4, 1999, pp. 207-211

Expression of p21 and MDM-2 proteins on tumor cells in responding and non-responding patients with Hodgkin's disease

P. Smolewski, H. Niewiadomska, E. Krykowski, T. Robak

Department of Hematology, Medical University of ŁódĽ, 93-513 ŁódĽ, Poland;
Department of Oncology, Medical University of ŁódĽ, ŁódĽ, Poland

Since the prevention of apoptosis can produce resistance to chemotherapy, abnormal expression of oncoproteins engaged in the regulation of this phenomenon in tumor cells may give some prognostic information in patients with neoplasma. To assess this problem in Hodgkin's disease (HD), the cellular expression of two p53 downstreams proteins p21 and MDM-2 was evaluated in the lymph nodes specimens obtained from 68 patients at the time of diagnosis, and compared with some clinical and pathological data. Positive immunoreaction for p21 and MDM-2 on Reed-Sternberg/Hodgkin's (R-S/H) cells was found in a majority of cases (58.8 and 63.2%, respectively). High expression of p21 protein correlated with poor response to the first-line treatment and disease free survival in both univariate and multivariate regression analysis, whereas expression of MDM-2 did not give prognostic information in patients with HD. Expression of p21 and MDM-2 was also compared with p53 protein immunoreactivity of R-S/H cells. The p21+/p53+ immunophenotype occurred to give particularly negative prognostic information in patients with HD. Diversity of p21/MDM-2/p53 patterns of R-S/H cells observed in particular patients may reflect heterogeneity of apoptosis regulatory mechanisms, as well as differences in p53 gene status.

Key words: Apoptosis, oncoproteins expression, Hodgkin's disease, prognostic factors.
NEOPLASMA, 46, 4, 1999, pp. 212-218

Changes in apoptotic and mitotic activity in rectal carcinoma after short-term cytostatic therapy as possible predictive factors

E. Farczádi, J. Szántó, I. Kaszás, I. Benyó, Zs. Bodnár, J. Szlobodnyik, B. Szende

Oncology Department, St Margit Hospital, Budapest, Hungary;
Pathology Department, St Margit Hospital, Budapest, Hungary;
Surgical Department, St Margit Hospital, Budapest, Hungary;
Surgical Department, Ferencz Toldi Hospital, Cegléd, Hungary;
1stInstitute of Pathology and Experimental Cancer Research, Semmelweis University of Medicine and Molecular Pathology Research Group of the Hungarian Academy of Sciences, H-1085, Budapest, Hungary

Fifteen patients with rectal adenocarcinoma were endoscopically biopsied and given short-term [5 fluorouracil (5FU) (600 mg/m2) and Ca-Folinate (60 mg/m2) for two days] cytostatic therapy. Seven days later the tumor was resected or a second biopsy was performed. Apoptotic and mitotic indices 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 4-13 months. Three patients showed progression of the disease, twelve improved or showed no tumor progression. An increase of the apoptotic index and decrease of the mitotic index after the short-term cytostatic treatment were seen in the tumor tissue of responder cases. Non-responders showed increase or no change in mitotic activity, and decrease or no change in apoptotic activity. These findings suggest that apoptotic and mitotic response to short-term cytostatic therapy may be additional predictive factor in rectal adenocarcinoma.

Key words: Apoptosis, mitotic activity, rectal adenocarcinoma, cytostatic therapy.
NEOPLASMA, 46, 4, 1999, pp. 219-223

Lyophilized whole human melanoma cells stimulate human PBMC proliferation and enhance suppressive action of PBMC toward survival of the same malignant cell line in vitro

Z.D. Juranić, T.P. Stanojković, N. Stanojević-Bakić, D. Miloąević, S. Radulović, I.O. Juranić

Institute for Oncology and Radiology of Serbia, 11 000 Belgrade, Yugoslavia;
Faculty of Chemistry, University of Belgrade, Belgrade, Yugoslavia

The goal of this work was to determine: a) do lyophilized human melanoma BG or Fem-X cells affect the proliferative capacity of normal human peripheral blood mononuclear cells (PBMC) and b) does the PBMC six-days preincubation in nutrient medium with FBS with, or without lyophilized human melanoma BG or Fem-x cells, affect their suppressive action on the survival of the same malignant cell line in vitro. In the aim to avoid any stimulating effect of FBS, other group of experiments were done in nutrient medium with human AB serum in order to determine: c) does the PBMC six-day-preincubation with lyophilized human melanoma BG or Fem-x cells affect their antiproliferative action on the corresponding malignant cell line in vitro and d) does the PBMC six-day preincubation with lyophilized normal PBMC, obtained from healthy volunteer (as a source of allogenous, but not of tumor antigens), affect their suppressive action on the survival of both melanoma BG and Fem-x cell lines in vitro.
Results obtained in the presence of FBS in nutrient medium, showed that lyophilized BG cells induced a proliferation of the healthy PBMC, depending on the number of stimulating lyophilized cells. Lyophilized Fem-x cells induced healthy PBMC proliferation in lesser degree than lyophilized BG cells. This stimulation was almost constant, not dependent on the number of stimulating lyophilized Fem-x cells. Six-day stimulation in vitro by both lyophilized melanoma cells enhanced the suppressive action of PBMC on the survival of the corresponding malignant cell line.
Experiments done in nutrient medium with normal human AB serum showed that six-day stimulation with lyophilized melanoma cells enhanced, again, the suppressive action of PBMC on the survival of the corresponding malignant cell line. Contrary, six day preincubation of normal PBMC with the lyophilized healthy PBMC (obtained from other healthy person) inhibited their suppressive action on the survival of both malignant cell lines in vitro.

Key words: Immunostimulation, Fem-x cells, BG cells, human PBMC, MTT.
NEOPLASMA, 46, 4, 1999, pp. 224-230

Separation of structurally related flavonoids by GC/MS technique and determination of their polarographic parameters and potential carcinogenicity

L. Novotný, A.Vachálková, T. Al-Nakib, N. Mohanna, D. Veselá, V. Suchý

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, Safat 13110, Kuwait;
Department of Experimental Therapy, Cancer Research Institute, Slovak Academy of Sciences, Bratislava, Slovak Republic;
Department of Pharmacology and Toxicology, Faculty of Medicine, Kuwait University, Safat, Kuwait;
Institute of Natural Drugs, Faculty of Pharmacy, Veterinary and Pharmaceutical University, Brno, Czech Republic

The present study deals with the investigation of the naturally occurring derivatives of the benzo[b]pyran-4-one - flavonoids - chrysin, tectochrysin and galangin, and with the effect of minor changes in their chemical structure on their separation using GC/MS. In the relation to their close chemical structure, their basic polarographic parameters were also investigated. Their potential carcinogenicity index tg alpha was determined by DC polarography experiments in the presence of alpha-lipoic acid. The tg alpha values for chrysin, tectochrysin and galangin were all under 0.180. This indicates a very minor carcinogenic potential that does not prevent the use of the investigated flavonoids in human.

Key words: Chrysin, tectochrysin, galangin, gas chromatography/mass spectroscopy, DC polarography, carcinogenicity.
NEOPLASMA, 46, 4, 1999, pp. 231-236

Combined effect of lipoic acid and doxorubicin in murine leukemia

I. Dovinová, L. Novotný, P. Rauko, P. Kvasnička

Cancer Research Institute, Slovak Academy of Sciences, 833 91 Bratislava, Slovak Republic;
Faculty of Farmacy, Kuwait University, SAFAT, Kuwait;
Faculty of Mathematics and Physics, Bratislava, Slovak Republic

Our experiments indicate that administration of a toxic drug with high rate of free-radical formation (doxorubicin, DOX) combined with an antioxidant (alpha-lipoic acid, LA) may lead to a decrease in drug-toxicity. However, the effects of antioxidant may be concentration-dependent and it is therefore crucial to choose its appropriate dosage. LA at a low concentration (1 ?mol/l) acts as a growth factor and at a higher concentration (100 ?mol/l) acts as an antiproliferation agent. Both concentrations of LA in combination with DOX were examined in cytotoxic and antitumor effects in L1210 mouse leukemia cells employing a MTT chemosensitivity assay. In most concentration combinations, DOX and LA effect were antagonistic and synergistic action was only found at the higher concentration of both agents (DOX 2.5 ?mol/l and LA 100 ?mol/l).
Use of LA in doxorubicin therapy lead to an increase (though marginally significant) in survival of animals. Combined single-dose administration of DOX (5 mg/kg) and LA (16 mg/kg) lead to super-additive effect of the combination on survival of leukemic mice.

Key words: Doxorubicin, lipoic acid, antioxidant, cytotoxicity.
NEOPLASMA, 46, 4, 1999, pp. 237-241

Evaluation of 2-(methylaminosulfonyl)-1-(arylsulfonyl)hydrazines as anticancer agents

M. Ghosh, S. Dutta, U. Sanyal

Department of Anticancer Drug Development and Chemotherapy, Chittaranjan National Cancer Institute, Calcutta ? 700 026, India

Seven new 2-(methylaminosulfonyl)-1-(arylsulfonyl)hydrazines were prepared and evaluated as potential antitumor agents in vivo against murine Ehrlich ascites carcinoma (EAC). Borderline in vivo activity in EAC was exhibited by two compounds. All of them were screened in vitro against a battery of human tumor cell lines at the National Cancer Institute (NCI), USA. One of them, namely compound 2f (NSC No. 649 752) displayed highly significant specificity in two different cell lines as non-small cell lung cancer line HOP-18 and in CNS cancer line SNB-19. The compounds assessed in vitro for anti-HIV activity also at the NCI, however, have not reached the criteria of significant activity. The alkylating activity of the compounds was determined by measuring the absorbance of the alkylated product of 4-(4-nitrobenzyl)pyridine. It was found that they are capable of acting as chemical alkylating agents.

Key words: New anticancer agents, mice, screening, Ehrlich ascites carcinoma, human tumor lines.
NEOPLASMA, 46, 4, 1999, pp. 242-245

Pentavalent Tc-99m dimercaptosuccinic acid imaging of hepatocellular carcinoma

S.J. Wang, W.Y. Lin, S.P. Wey, L.H. Shen, G. Ting

Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung, 407 Taiwan, R.O.C.;
Institute of Nuclear Energy Research, Lung-Tan, Taiwan

Tc-99m (V)-dimercaptosuccinic acid (DMSA) has been used to image various kinds of tumors. However, from a review of the literature, it has never been applied to hepatocellular carcinoma (HCC). Low uptake of Tc-99m (V)-DMSA has been demonstrated in normal liver tissue, thus, Tc-99m (V)-DMSA may be useful for the detection of HCC.
Nine male patients with focal nodular HCC were studied with sequential X-ray CT, Tc-99m (V)-DMSA and Tc-99m phytate liver scan. Our data showed that eight patients had increased uptake of Tc-99m (V) DMSA in HCC. Four cases demonstrated higher Tc-99m (V) DMSA uptake in HCC than in adjacent liver, and four cases demonstrated HCC uptake equal to liver uptake. One case showed no uptake of Tc-99m (V) DMSA in HCC. The detection sensitivity of Tc-99m (V)-DMSA was 88.9%. From our early results, Tc-99m (V)-DMSA is a readily available tumor imaging agent that appears to accumulate in HCC.

Key words: Dimercaptosuccinic acid, hepatocellular carcinoma, tumor imaging, Tc-99m phytate liver scan.
NEOPLASMA, 46, 4, 1999, pp. 246-248

Doppler flowmetry in the differentiation of biological characteristics of ovarian cancer

V. Lehotská, J. ©vec, A. Ďurkovský, A. ©uhajdová, Ą. ©evčíková

Clinic of Oncology, Faculty of Medicine, Comenius University, 812 01 Bratislava, Slovak Republic;
Department of Radiodiagnostics, St. Elisabeth Institute of Oncology, Bratislava, Slovak Republic;
Department of Radiotherapy, St. Elisabeth Institute of Oncology, Bratislava, Slovak Republic

On basis of ultrasonographic structural criteria and Doppler flowmetry in a group of 76 patients with ovarian cancer, benign lesions were discovered in 59 patients and malignant lesions in 17 patients (77.6% and 22.4%, respectively). Surgical intervention was indicated according to the clinical findings and following of the trend of organ-specific oncomarkers in 32 out of 76 patients (42.1%). The stratification involved 17 patients with sonomorphologically/Doppler-flowmetry - diagnosed malignancy as well as 15 patients with sonographically diagnosed benign ovarian tumor. The clinical findings were histologically verified in all 32 patients. Histology confirmed malignant tumor in 16 patients, 1 histologically borderline malignancy and 15 benign tumors. The Doppler-flowmetry showed 94.1% sensitivity, 93.3% specificity, 93.3% positive predictive value, and 93.75% accuracy.

Key words: Ovarian cancer, Doppler flowmetry, angioneogenesis.
NEOPLASMA, 46, 4, 1999, pp. 249-252

Relevance of the Doppler flowmetry in the diagnosis of pathological alterations in the post-menopausal endometrium

V. Lehotská, J. ©vec, A. Ďurkovský, A. ©uhajdová, Ą. ©evčíková

Clinic of Oncology, Faculty of Medicine, Comenius University, 812 01 Bratislava, Slovak Republic;
Department of Radiodiagnostics, St. Elisabeth Institute of Oncology, Bratislava, Slovak Republic;
Department of Radiotherapy, St. Elisabeth Institute of Oncology, Bratislava, Slovak Republic

The sonopathomorphology of the menopausal endometrium was investigated by measuring the endometrium thickness using the Doppler flowmetry technique. The endometrium thickness extending five millimeters has been considered critical, indicating possible neoplastic disorders. Such clinical status has been discovered in 21 out of 58 post-menopausal patients inspected (36.2%). Furthermore, the Doppler blood-flow analysis, based on the evaluation of the resistance indices (RI) in the ascendent branches of uterine arteries bilaterally, and - in case of the vascularization analysis - in the edometrial and perimetrial regions, has been performed. These investigations brought evidence indicating full capacity of the method in detecting blood flow through the uterine arteries, while significant differences in the endometrial flow-through parameters were detected only in 14 (66.7%) patients. In all 21 patients with endometrium thickness extending 5 millimeters, bioptic examination followed by histology confirmed endometrial cancer in 9 patients, epidermoid cancer in 3 patients, and cystic hyperplasia in 3 patients, respectively. The remaining 6 patients showed either secretory or quiet endometrium (5 cases), or necrotic endometrial regions (1 case). In all 12 cases of malignant endometrial cancer and in 2 out of 3 cases of histologically verified benign hyperplasia, intra- and periendometrial vascularization has been confirmed. It is to note that the mean RI values measured in the intra- and periendometrial vessels in case of endometrial cancer were significantly lower than in patients with benign cystic hyperplasia of the endometrium. Our results brought evidence indicating that the estimation of differences in the RI values in patients with detectable intra- and periendometrial vascularization has a significant relevance in the distinction of endometrial cancer from nonmalignant endometrial lesions, predominantly the benign atypical hyperplasia. The reliability of the test was 100%, however - in case of malignant disorders - a significant decrease in the RI values has been seen in the intratumoral vs. peritumoral vascularization.

Key words: Doppler flowmetry, postmenopausal endometrium, endometrial cancer, benign atypic hyperplasia.
NEOPLASMA, 46, 4, 1999, pp. 253-256