[Prognostic importance of selected molecular genetic immunohistochemical markers and DNA ploidy in endometrial cancer]

OBJECTIVE

The aim of the study was the analysis of the new molecular genetic immunomarkers (p53, c-erbB-2, Ki 67, bcl-2) hormonal receptors (ER, PR) and ploidy disturbances and their relation to the most important prognostic factors for endometrial cancer.

DESIGN

Prospective study.

SETTING

Dept. of Gynaecology and Obsterics, Laboratory of Experimental Medicine, Institute of Pathology, Institute of Molecular and Transplational Medicine, Medical Faculty and University Hospital, Olomouc.

METHODS

The study group consisted of 88 endometrial cancer patients. The biopsies of the tumours obtained at operations were routinely histopathologically examined. Subsequently, the immunohistochemical tumormarkers were determined. The same biopsies were examined by microdissection and flow cytometric ploidy analysis and karyotyping. The findings were compared with the most important prognostic factors for endometrial cancer, mainly with clinical stage of the disease, grade and histopathological type.

RESULTS

Aneuploidy was found in 71% in the group of poorly differentiated endometrial cancers (G3) in contrast to 47% in the group of G1 and G2 tumours. High expression of p53, Ki 67, c-erbB-2 and low rate of sex hormone receptors was found in the prognostically unfavourable group (G3).

CONCLUSIONS

Aneuploidy seems to be an important prognostical factor for endometrial cancer patients. Identification of p53, Ki 67, c-erbB-2, ER a PR is a useful tool to specify a group of prognostically unfavourable patients.

Anticancer activity of natural cytokinins: a structure-activity relationship study

Cytokinin ribosides (N(6)-substituted adenosine derivatives) have been shown to have anticancer activity both in vitro and in vivo. This study presents the first systematic analysis of the relationship between the chemical structure of cytokinins and their cytotoxic effects against a panel of human cancer cell lines with diverse histopathological origins. The results confirm the cytotoxic activity of N(6)-isopentenyladenosine, kinetin riboside, and N(6)-benzyladenosine and show that the spectrum of cell lines that are sensitive to these compounds and their tissues of origin are wider than previously reported. The first evidence that the hydroxylated aromatic cytokinins (ortho-, meta-, para-topolin riboside) and the isoprenoid cytokinin cis-zeatin riboside have cytotoxic activities is presented. Most cell lines in the panel showed greatest sensitivity to ortho-topolin riboside (IC(50)=0.5-11.6 microM). Cytokinin nucleotides, some synthesized for the first time in this study, were usually active in a similar concentration range to the corresponding ribosides. However, cytokinin free bases, 2-methylthio derivatives and both O- and N-glucosides showed little or no toxicity. Overall the study shows that structural requirements for cytotoxic activity of cytokinins against human cancer cell lines differ from the requirements for their activity in plant bioassays. The potent anticancer activity of ortho-topolin riboside (GI(50)=0.07-84.60 microM, 1st quartile=0.33 microM, median=0.65 microM, 3rd quartile=1.94 microM) was confirmed using NCI(60), a standard panel of 59 cell lines, originating from nine different tissues. Further, the activity pattern of oTR was distinctly different from those of standard anticancer drugs, suggesting that it has a unique mechanism of activity. In comparison with standard drugs, oTR showed exceptional cytotoxic activity against NCI(60) cell lines with a mutated p53 tumour suppressor gene. oTR also exhibited significant anticancer activity against several tumour models in in vivo hollow fibre assays.

6-(Het)aryl-7-deazapurine ribonucleosides as novel potent cytostatic agents

A series of novel 7-deazapurine ribonucleosides bearing an alkyl, aryl, or hetaryl group in position 6 and H, F, or Cl atom in position 7 has been prepared either by Pd-catalyzed cross-coupling reactions of the corresponding protected 6-chloro-(7-halogenated-)7-deazapurine ribonucleosides with alkyl- or (het)arylorganometallics followed by deprotection, or by single-step aqueous phase cross-coupling reactions of unprotected 6-chloro-(7-halogenated-)7-deazapurine ribonucleosides with (het)arylboronic acids. Significant cytostatic effect was detected with a substantial proportion of the prepared compounds. The most potent were 7-H or 7-F derivatives of 6-furyl- or 6-thienyl-7-deazapurines displaying cytostatic activity in multiple cancer cell lines with a geometric mean of 50% growth inhibition concentration ranging from 16 to 96 nM, a potency comparable to or better than that of the nucleoside analogue clofarabine. Intracellular phosphorylation to mono- and triphosphates and the inhibition of total RNA synthesis was demonstrated in preliminary study of metabolism and mechanism of action studies.

Functional p53 in cells contributes to the anticancer effect of the cyclin-dependent kinase inhibitor roscovitine

Inhibitors of cyclin-dependent kinases (CDKs) undergoing clinical trials as anticancer agents usually target several CDKs in cells. Some of them are also able to increase cellular levels of p53 protein and to activate p53-regulated transcription. To define the role of p53 in the anticancer effect of selective CDK inhibitors, two related compounds roscovitine and olomoucine II were studied. Roscovitine differs functionally from its congener olomoucine II only in the selectivity towards transcriptional CDK9. Action of both compounds on proliferation, cell-cycle progression, and apoptosis was examined in RPMI-8226 cells expressing the temperature-sensitive mutant of p53 and in MCF-7 cells with wild-type p53. Both compounds blocked proliferation, decreased phosphorylation of RNA polymerase II, downregulated antiapoptotic protein Mcl-1 in both cell lines in a dose-dependent manner, and also activated p53 in MCF-7 cells. Moreover, we showed that the anticancer efficiency of CDK inhibitors was enhanced by active p53 in RPMI-8226 cells kept at permissive temperature, where downregulation of Mcl-1, fragmentation of PARP-1, and increased caspase-3 activity was detected with lower doses of the compounds. The results confirm that functional p53 protein may enhance the anticancer activity of roscovitine that could be beneficial for anticancer therapy.

Cyclocondensation reaction of heterocyclic carbonyl compounds. Part XIII: synthesis and cytotoxic activity of some 3,7-diaryl-5-(3,4,5-trimethoxyphenyl)pyrazolo[4,3-e][1,2,4]triazines

A series of the 3,7-diaryl-5-(3,4,5-trimethoxyphenyl)pyrazolo[4,3-e][1,2,4]triazines have been synthesized in five steps. The cytotoxic activity of all of the newly synthesized compounds has been tested in vitro against five cancer cell lines. Several compounds demonstrated significant broad cytotoxic activity in low micromolar range, while others were selectively active against lung adenocarcinoma cell line A549.

4-arylazo-3,5-diamino-1H-pyrazole CDK inhibitors: SAR study, crystal structure in complex with CDK2, selectivity, and cellular effects

In a routine screening of our small-molecule compound collection we recently identified 4-arylazo-3,5-diamino-1H-pyrazoles as a novel group of ATP antagonists with moderate potency against CDK2-cyclin E. A preliminary SAR study based on 35 analogues suggests ways in which the pharmacophore could be further optimized, for example, via substitutions in the 4-aryl ring. Enzyme kinetics studies with the lead compound and X-ray crystallography of an inhibitor-CDK2 complex demonstrated that its mode of inhibition is competitive. Functional kinase assays confirmed the selectivity toward CDKs, with a preference for CDK9-cyclin T1. The most potent inhibitor, 4-[(3,5-diamino-1H-pyrazol-4-yl)diazenyl]phenol 31b (CAN508), reduced the frequency of S-phase cells of the cancer cell line HT-29 in antiproliferation assays. Further observed cellular effects included decreased phosphorylation of the retinoblastoma protein and the C-terminal domain of RNA polymerase II, inhibition of mRNA synthesis, and induction of the tumor suppressor protein p53, all of which are consistent with inhibition of CDK9.

New derivatives of silybin and 2,3-dehydrosilybin and their cytotoxic and P-glycoprotein modulatory activity

Large series of O-alkyl derivatives (methyl and benzyl) of silybin and 2,3-dehydrosilybin was prepared. Selective alkylation of the silybin molecule was systematically investigated. For the first time we present here, for example, preparation of 19-nor-2,3-dehydrosilybin. All prepared silybin/2,3-dehydrosilybin derivatives were tested for cytotoxicity on a panel of drugs sensitive against multidrug resistant cell lines and the ability to inhibit P-glycoprotein mediated efflux activity. We have identified effective and relatively non-cytotoxic inhibitors of P-gp derived from 2,3-dehydrosilybin. Some of them were more effective inhibitors at concentrations lower than a standard P-gp efflux inhibitor cyclosporin A. Another group of 2,3-dehydrosilybin derivatives also had better inhibitory effects on P-gp efflux but a cytotoxicity comparable with that of parent 2,3-dehydrosilybin. Structural requirements for improving inhibitory activity and reducing toxicity of 2,3-dehydrosilybin were established. Effect of E-ring substitution as well as an influence of the substituent size at the C-7-OH position of A-ring on P-gp-inhibitory activity was evaluated for the first time in this study.

New Lupane Derived Compounds with Pro-Apoptotic Activity in Cancer Cells: Synthesis and Structure−Activity Relationships

Cellular screening of various synthetic triterpenoid compounds formally derived from lupane has identified a number of analogues as potential anticancer drug candidates. Here we describe the synthesis and structure-activity relationships of betulin and betulinic acid derivatives containing an E-ring modified with different oxygen functions. Thus compounds containing the lup-18-en-21-one, lup-18-ene-21,22-dione, 18,19-secolupane, and the highly oxygenated 18,19-secolupane systems, as well as des-E-lupane derivatives, were prepared from the readily available natural pentacyclic triterpene betulin using oxidative procedures. These compounds were named betulinines. We demonstrate that only selected compounds, particularly those containing a lupane E-ring-derived unsaturated ketone or diketone function, possessed in vitro cytotoxic activity against tumor cell lines, suggesting a structure-activity relationship.

[Tumor biopsy--a trivial matter or a basic procedure?]

The surgeon is frequently faced with the task of bioptic sampling of tissues from patients with tumourous diseases. The importance of such frequently minor procedures is incorrectly underrated. The importance of biopsy is in the foreground in particular at present at a time of individualization of treatment of malignant tumours, based on the development of new diagnostic-therapeutic methods. The bioptic specimen is the fundamental link in the basic decision--benignity or malignity--and also a unique source for assessment of prognostic and predictive factors on the basis of which we select the optimal therapeutic procedure. Contrary to current histopathological examination where the principles of correct collection of tissues specimens are generally known, in recent years the importance of molecular examinations is increasing where the surgeon must respect certain different principles to make the sampling successful. The authors working in a department of surgical oncology along with authors from specialized laboratories formulate rules of correct implementation of biopsies and transport of biological material in conjunction with recent laboratory methods, and based on examples of their own practice, they demonstrate how the initial approach of the surgeon can influence in a decisive way the correct diagnosis and therapeutic procedure in oncological patients.