Synthesis of trans-16-triazolyl-13α-methyl-17-estradiol diastereomers and the effects of structural modifications on their in vitro antiproliferative activities.

Novel 16-triazoles in the 13α-estrone series were synthesized via Cu(I)-catalyzed azide-alkyne cycloaddition of the two diastereomeric (on C-16 and on C-17) 16-azido-13α-estra-1,3,5(10)-trien-17-ol 3-benzyl ethers with substituted phenylacetylenes. The new heterocyclic derivatives were evaluated in vitro by means of MTT assays for antiproliferative activity against a panel of human adherent cancer cell lines (HeLa, MCF-7, A431, A2780, T47D, MDA-MB-231 and MDA-MB-361). The inversion of the configurations at C-16 and C-17 selectively affected the growth-inhibitory properties of the tested compounds. The 16ß,17α isomers generally proved to be potent on all cell lines, with IC50 values comparable to those of the reference agent cisplatin. Change of the substitution pattern of the phenyl group of the acetylene led to great differences in antiproliferative properties. Exclusively the p-phenyl-substituted triazoles exerted high cytostatic effects. One of the most potent compounds activated caspase-3 and caspase-9 without influencing caspase-8, confirming the induction of apoptosis via the intrinsic pathway.

Synthesis and in vitro antiproliferative evaluation of d-secooxime derivatives of 13ß- and 13α-estrone.

d-Secooximes were synthesized from the d-secoaldehydes in the 13ß- and 13α-estrone series. The oximes were modified at three sites in the molecule: the oxime function was transformed into an oxime ether, oxime ester or nitrile group, the propenyl side-chain was saturated and the 3-benzyl ether was removed in order to obtain a phenolic hydroxy function. Triazoles were formed via Cu(I)-catalysed azide-alkyne cycloaddition (CuAAC) from 3-(prop-2-yniloxy)-d-secooximes and benzyl azides. All the products were evaluated in vitro by means of MTT assays for antiproliferative activity against a panel of human adherent cell lines (HeLa, MCF-7, A2780 and A431). Some of them exhibited activities with submicromolar IC50 values, better than that of the reference agent cisplatin. The structural modifications led to significant differences in the cytostatic properties. Flow cytometry indicated that one of the most potent agents resulted in a cell cycle blockade.

A facile access to novel steroidal 17-2'-(1',3',4')-oxadiazoles, and an evaluation of their cytotoxic activities in vitro.

Novel types of 17-exo-heterocycles in the Δ(5) androstene series carrying an 1,3,4-oxadiazole moiety were efficiently synthesized via aldehyde N-acylhydrazone intermediates, obtained from the microwave-assisted condensation of 3ß-hydroxy- or 3ß-acetoxyandrost-5-ene-17ß-carbaldehyde with different acylhydrazides. The subsequent phenyl iodonium diacetate-induced oxidative cyclization proceeded under mild conditions. The synthesized compounds were subjected to in vitro pharmacological studies to investigate their antiproliferative activities on four malignant adherent cell lines (HeLa, MCF7, A2780 and A431), and exhibited the highest potency against HeLa cells, some of them revealing action comparable to that of the reference agent cisplatin.

An efficient approach to novel 17-5'-(1',2',4')-oxadiazolyl androstenes via the cyclodehydration of cytotoxic O-steroidacylamidoximes, and an evaluation of their inhibitory action on 17α-hydroxylase/C17,20-lyase.

Novel 17-exo-oxadiazoles in the androst-5-ene series were efficiently synthesized in a two-step sequence via the corresponding O-acylamidoxime intermediates (obtained from steroidal 17-carboxylic acids and amidoximes in the presence of coupling reagent), which then underwent tetrabutylammonium fluoride-induced cyclocondensation under mild reaction conditions. The synthesized compounds were subjected to in vitro pharmacological studies to investigate their inhibitory effect on rat testicular C17,20-lyase and their antiproliferative action on four malignant human adherent cell lines (HeLa, MCF7, A2780 and A431). One of the oxadiazolyl derivatives proved to exert significant enzyme-inhibitory action (IC50 = 0.60 µM), while some of the isolated O-acylated amidoxime intermediates displayed high cytotoxic activities on all examined cell lines, with IC50 values in the range 0.22-3.94 µM.

Cycloaddition of steroidal cyclic nitrones to C=N dipolarophiles: stereoselective synthesis and antiproliferative effects of oxadiazolidinones in the estrone series.

Cyclic nitrones of estrone 3-methyl or 3-benzyl ether were reacted with phenyl isocyanate or nonsubstituted phenyl isocyanates as reactive CN dipolarophiles, yielding condensed homosteroidal oxadiazolidinones. These dipolar cycloadditions were carried out under conventional heating or microwave irradiation. The chemo- and stereoselectivities of the reactions and the effects of the aromatic substituents on the reaction rates and yields were investigated and compared. The structures of the new products were determined by NMR (one- and two-dimensional) and MALDI-MS techniques, with C70 fullerenes as matrix in the latter case. The antiproliferative properties of the synthetized compounds were determined on a panel of human adherent cell lines (HeLa, MCF7, A2780 and A431) by means of MTT assays. Some of them exhibited activities comparable to that of the reference agent cisplatin. Flow cytometry indicated that one of the most potent agents (11a) resulted in a cell cycle blockade.

Genotypic analysis of two hypervariable human cytomegalovirus genes.

Most human cytomegalovirus (HCMV) genes are highly conserved in sequence among strains, but some exhibit a substantial degree of variation. Two of these genes are UL146, which encodes a CXC chemokine, and UL139, which is predicted to encode a membrane glycoprotein. The sequences of these genes were determined from a collection of 184 HCMV samples obtained from Africa, Australia, Asia, Europe, and North America. UL146 is hypervariable throughout, whereas variation in UL139 is concentrated in a sequence encoding a potentially highly glycosylated region. The UL146 sequences fell into 14 genotypes, as did all previously reported sequences. The UL139 sequences grouped into 8 genotypes, and all previously reported sequences fell into a subset of these. There were minor differences among continents in genotypic frequencies for UL146 and UL139, but no clear geographical separation, and identical nucleotide sequences were represented among communities distant from each other. The frequent detection of multiple genotypes indicated that mixed infections are common. For both genes, the degree of divergence was sufficient to preclude reliable sequence alignments between genotypes in the most variable regions, and the mode of evolution involved in generating the genotypes could not be discerned. Within genotypes, constraint appears to have been the predominant mode, and positive selection was detected marginally at best. No evidence was found for linkage disequilibrium. The emerging scenario is that the HCMV genotypes developed in early human populations (or even earlier), becoming established via founder or bottleneck effects, and have spread, recombined and mixed worldwide in more recent times.

[Possibilities of postnatal diagnosis in congenital cytomegalovirus infection]. / A congenitalis cytomegalovirus-fertózés postnatalis diagnosztikájának lehetóségei két eset kapcsán.

The authors review two cases of suspected congenital cytomegalovirus (CMV) infections in which modern laboratory approaches were applied to establish the diagnosis postnatally. In the first case, intrauterine infection was suggested by ventriculomegaly, detected by means of a head ultrasonographic scan. The postnatal cranial ultrasonography and computed tomographic scans revealed intracerebral calcifications. CMV was detected in the blood and urine of the newborn. The postnatal serological tests proved that the mother had experienced a primary CMV infection during gestation. Abnormal neurological signs developed in the infant by the age of 9 months. In the second case, the mother had had an active CMV infection at 29 weeks of gestation involving a twin pregnancy. The CMV-specific serological tests demonstrated that this was a recurrent infection. The twins were born without signs or clinical symptoms and CMV was not detected in their urine samples. At 5 months of age, one of the twins excreted CMV in his urine, which must have been a consequence of a postnatal infection. The general screening of young women by CMV serology at the beginning of gestation is recommended. This would establish a CMV serostatus and provide an opportunity for the gynecologist to provide advice concerning the avoidance of infection, especially in cases where the patient is seronegative and therefore at risk of primary CMV infection.

Mother-to-fetus transmission of cytomegalovirus. A review.

Congenital human cytomegalovirus (CMV) infection is the leading infectious cause of mental retardation, sensorineural deafness and visual impairment. It is mainly related to a primary maternal infection. The placenta should be considered the most important site of both the protection of the fetus from CMV infection and the transmission of CMV from mother to fetus. The control of the passage of CMV across the placenta probably involves a cascade of regulatory events. Roles are played by factors relating to the host immune-selective pressures, such as local cytokines and maternal CMV-specific neutralizing antibodies. The presence of other pathogens at the maternal-fetal interface also influences the outcome of CMV infection. Further investigations are needed in which clinical CMV strains are applied in in vitro studies to unravel the molecular mechanism of the intrauterine transmission of CMV and to elucidate the complex regulation that leads to prevention of the in utero transmission of CMV in vivo.