Cytogenetic and growth factor gene analysis of a renal carcinoma cell line.

Although there are many studies analyzing cytogenetic or molecular alterations of human renal primary tumors, there have only been a few reports addressing both questions on renal cell carcinoma (RCC) cell lines. We have therefore investigated an RCC cell line, namely KTCTL-26A, by banding techniques and simultaneous growth factor gene expression analysis. KTCTL-26A represents a well-defined stemline and sidelines in the near-diploid range with clonal aberrations involving chromosomes 2, 3, 5, 7, 9, 13, 16, 21, 22, and Y in structure and/or number. The predominant karyotypic changes were a partial loss of chromosome 3p (ie, 3p14) and a gain of copies of chromosome 7 (trisomy or partial tetrasomy). By Northern analysis, in KTCTL-26A we found underexpression of the proEGF-gene (located on chromosome 4) and overexpression of the genes for proTGF-alpha and the EGF-receptor, which are located on chromosomes 2 and 7, respectively. By Southern blot analyses there was no evidence for an amplification in the case of the EGF-R and proTGF-alpha genes. Because these changes of gene expression were observed in both the cell line and in primary kidney tumor samples, they seem to be of constitutive (and not adaptive) nature. Hence, KTCTL-26A can serve as a model for the study of the origin of these molecular alterations and as a preclinical model for their genetic manipulation (e.g., by using antisense-oligonucleotides) for therapeutic purposes.

Prenatal diagnosis by amniocentesis in 82 pregnancies after in vitro fertilization.

We report on the outcome of 82 amniocenteses (AC) carried out during pregnancies after in vitro fertilization (IVF) from 1-1-1985 to 31-12-1989. The main indication for amniocentesis was a maternal age of greater than or equal to 35 years. In 48 cases, we found an anterior placenta and assumed that this was related to the position in which the uterine embryo transfer was performed. In six pregnancies, we found an abnormal karyotype, including two cases of trisomy 21; the two couples decided for abortion. Four aberrations in the fetal karyotypes were also present in either the mother or the father, the resulting children are healthy. The further course of pregnancies after IVF and AC was characterized by a higher incidence of toxemia, uterine bleeding before the 28th week of gestation, abruptio placentae, and premature deliveries, when compared to the course of pregnancies after spontaneous conception. We believe that these occurrences were not caused by AC, as the incidence was higher in all our pregnancies after IVF (without AC) and has also been reported in pregnancies after ovarian hyperstimulation without IVF. Therefore, we see no reason to renounce AC after IVF. However, the special risks inherent in pregnancies after IVF must always be discussed with the couple.

[Initial experiences with amniocentesis for prenatal diagnosis in pregnancy following in-vitro fertilization]. / Erste Erfahrungen mit der Amniozentese zur pränatalen Diagnostik bei Graviditäten nach In-vitro-Fertilisation.

We report on first experiences with amniocentesis in 63 pregnancies after IVF treatment over a period of 3 years. It is shown, that there is no increased risk through amniocentesis; it does not require special precautions. Above average number of aberrations could be found in amniotic cultures in cases where it could be identified additionally in one parent. It remains to be seen, whether the small number and sterility causes were coincidental or manifest themselves in future, especially, if the sterility concerned can be classified as idiopathic. The occurrence of trisomy 21 in accordance with the frequency is to be expected in the group of persons over 35 years of age and no increased risk through IVF treatment can be found.

Cell culture studies on neurofibromatosis (von Recklinghausen). V. Monosomy 22 and other chromosomal anomalies in cultures from peripheral neurofibromas.

Cell cultures grown from peripheral neurofibromas of three patients suffering from sporadic peripheral neurofibromatosis (NF) were analysed cytogenetically at early in vitro passages. The NF-cultures exhibited a 6.7-fold higher frequency of aneuploid mitoses, including pseudodiploids, than the control cultures derived from the skin of three healthy donors. The predominant numerical anomaly was monosomy 22. Several, as yet unidentified marker chromosomes occurred in the NF-cultures, which also showed a much higher level of unstable chromosomal anomalies. The role of monosomy 22 in tumorigenesis of meningiomas and neurofibromas is discussed.