Effective treatment of experimental U-87MG human glioblastoma in nude mice with a targeted cytotoxic bombesin analogue, AN-215.

Some brain tumours, such as glioblastomas express high levels of receptors for bombesin/gastrin releasing peptide. We investigated whether bombesin/gastrin releasing peptide receptors found in glioblastoma cell lines can be utilised for targeting of a cytotoxic bombesin analogue, AN-215 consisting of a potent derivative of doxorubicin, 2-pyrrolino-doxorubicin (AN-201) linked to a bombesin-like peptide carrier. This study reports the effect of AN-215 on the growth of U-87MG human glioblastomas xenografted into nude mice. High affinity binding of AN-215 to U-87MG tumours was characterised by an IC(50) value of 4.0+/-0.1 nM, as determined by radioreceptor assays. mRNA analyses revealed the presence of mRNA for BN receptor subtypes 1 and 2. Treatment with AN-215 significantly (P<0.05) extended tumour doubling time from 4.54+/-0.2 days to 8.18+/-1.8 days and inhibited tumour growth as demonstrated by a 69.6% reduction in final tumour volume (P<0.001) and a 64.6% decrease in tumour weight as compared to controls. Cytotoxic radical AN-201 at the same dose was ineffective. The antitumour effect of AN-215 could be blocked by pretreatment with an excess of a bombesin antagonist, indicating that the action of this cytotoxic analogue is receptor-mediated. Our results suggest that patients with inoperable brain tumours such as malignant gliomas may benefit from targeted chemotherapy based on cytotoxic bombesin analogue AN-215.

Somatic mutation of the 5' noncoding region of the BCL-6 gene is associated with intraclonal diversity and clonal selection in histological transformation of follicular lymphoma.

Follicular lymphoma (FL) is a B cell non-Hodgkin's lymphoma (NHL) that frequently displays a t(14;18) translocation. Clonal evolution and histological transformation of FL is frequently associated with the accumulation of secondary genetic alterations. It has been demonstrated that the BCL-6 gene can be altered by chromosomal rearrangements and by mutations clustering in its 5' noncoding region in a significant fraction of FL and diffuse large cell lymphoma (DLCL). To elucidate the role of the BCL-6 gene alterations in the histological transformation and clonal progression of FL, we analyzed serial biopsy specimens from 12 patients with FL. Two cases of FL showed no histological alteration in the second biopsy, and 10 cases of FL showed morphological transformation to DLCL in the second biopsy. Southern blot analysis was used to detect rearrangement of the BCL-6 gene, polymerase chain reaction-single strand conformation polymorphism and sequence analysis were performed for identification of mutations in the 5' noncoding region of the BCL-6 gene, and immunohistochemical analysis was applied to reveal the BCL-6 protein expression. No BCL-6 gene rearrangement was detected in any of the samples, but a total of 58 mutations were found in the 5' noncoding region of the BCL-6 gene in seven cases. In five cases, both the FL and the clonally related FL or DLCL, and in two cases only the DLCL samples were mutated. The mutations were identical in multiple biopsy specimens of FL that did not show morphological transformation. In six patients where FL cells underwent morphological transformation, considerable intraclonal sequence heterogeneity was observed, indicating an ongoing type of somatic mutation. Based on the pattern of shared and nonshared mutations, the genealogical relationship of neoplastic clones could be established. In all of these cases, the histological transformation of FL was associated with the emergence of a subpopulation marked by new sites of mutations in the BCL-6 5' noncoding sequences. In three of these six cases, the histological transformation is also associated with the reduced expression of the BCL-6 protein. These findings demonstrate that mutation of the 5' noncoding region of the BCL-6 gene developed in the clonal evolution of FL, and at different time points in the lymphoma evolution different clonotypes dominate.

Genetic instability is associated with histological transformation of follicle center lymphoma.

Follicle center lymphoma (FCL) is an indolent B cell non-Hodgkin's lymphoma (NHL) characterized genetically by the t(14;18) translocation. Histological transformation and clinical progression of FCLs are frequently associated with secondary genetic alterations at both nucleic acid and chromosomal levels. To determine the type and pattern of genomic instability occurring in histological transformation of FCLs and the role of DNA mismatch repair defects in this procedure, we have performed microsatellite analysis, comparative genomic hybridization (CGH) and mutational analysis of hMLH1 and hMSH2 genes on serial biopsy specimens from patients with FCL transformed to diffuse large cell lymphoma (DLCL). Paired biopsy samples of eight patients were analyzed for microsatellite instability and structural alterations for hMLH1 and hMSH2 genes, and tumor samples of five patients were subjected to CGH analysis. A high level of microsatellite instability was associated with histological transformation of two cases of FCL, but no mutations of the hMLH1 and hMSH2 genes were detected in any of the lymphoma samples. In the five cases subjected to CGH analysis, the histological transformation of FCLs was associated with genomic imbalances at 21 chromosomal regions. The genomic abnormalities found were rather heterogeneous and none of the genetic changes were overrepresented in the transformed DLCLs. These data suggest that histological transformation of FCLs to DLCL is frequently associated with genome wide instability at both nucleic acid and chromosomal levels, although mutations of the hMSH1 and hMLH2 genes are not involved in this process.

Renal angiomyolipoma: report of three cases with regional lymph node involvement and/or with renal cell carcinoma.

AIMS AND BACKGROUND: Angiomyolipomas (AMLs) are benign hamartoid tumors which frequently occur in tuberous sclerosis (TS). They may be manifest at different organ sites such as kidneys, lymph nodes, liver and lung and may be associated with renal cell carcinoma (RCC). The nature of multiple organ involvement in AML (metastasis versus multicentric synchronous tumors), the malignant transformation and the relation of AML to RCC have not been sufficiently clarified. STUDY DESIGN: Three cases of renal AMLs in patients with tuberous sclerosis associated with lymphangioleiomyomatosis of the paraaortic lymph nodes and/or with RCC are reported. The concise clinical history of the patients as well as the findings of histology, immunohistochemistry and quantitative DNA analysis are presented. RESULTS: The multicentric form of AML and coincidence of renal AML and RCC were observed in 2 patients. AML and RCC were found within the same focus in one of the cases. RCCs were either aneuploid or "near diploid", whereas one of the multicentric AMLs showed a discordant DNA ploidy pattern, namely aneuploidy in the kidney and diploidy in the lymph nodes. CONCLUSIONS: The presented cases (all of them underwent periaortic lymphadenectomy) suggest that lymph node involvement in renal AML may be more frequent than expected (1-2% of all AMLs) on the basis of the few reported cases. The discordant DNA ploidy (renal versus lymph node lesions) observed in one of the cases with multicentric AML implies synchronous tumor growth at different sites rather than metastatic disease. The intimate coexistance of RCC and AML (RCC revealed by immunohistochemistry within a larger mass of renal AML) may indicate that malignant transformation of an AML should only be accepted, if such a coincidence is unequivocally excluded.

[The significance of cytotoxic activity of maternal lymphocytes for the etiology of intrauterine growth retardation]. / Zur Bedeutung der zytotoxischen Aktivität der mütterlichen Lymphozyten für die Atiologie der intrauterinen Mangelentwicklung.

Natural lymphocyte cytotoxicity of 99 pregnant women delivering intrauterine growth retarded (IUGR) babies was compared to that of 460 women with normal pregnancies. Lymphocytes separated from maternal blood were used as effectors in the in vitro cytotoxicity test using human embryonic fibroblast cells as target. The cytotoxicity test was based on the assessment of endogenous alkaline phosphatase activity of the target cells. A definite shift towards IUGR pregnancies was observed in the distribution of patients when analyzed according to step by step increase of lymphocyte cytotoxicity values. The incidence of increased cytotoxic activity (greater than or equal to 40%) was three times higher in the group of women with IUGR pregnancies than that in the control group. Within the group of women showing increased immunoreactivity during pregnancy the participation of IUGR pregnancies was 40.4%, while only 9.7% of the women with normal cytotoxicity belonged to the IUGR group. Combined analysis of ponderal indices and cytotoxicity values suggests that increased immunoreactivity is associated with a nutritive insufficiency resulting in the disproportionate form of IUGR.

Early pregnancy loss, premature and low birth weight delivery, and increased maternal lymphocyte cytotoxicity.

Lymphocytes of 628 pregnant women were tested for natural cytotoxic activity to human embryonic fibroblast cells. The data were analyzed with regard to previous obstetric history, symptoms occurring during the present gestation, and the outcome of pregnancy. The normal rate of cytotoxicity during pregnancy was established by determining cytotoxic activity of the lymphocytes from 56 healthy pregnant women. The values higher than the mean + 2 SD of the "normal" (greater than or equal to 40%) were considered as high. Increased cytotoxicity was associated with the occurrence of previous spontaneous and missed abortions, as well as with bleeding and uterine contractions during the present pregnancy observed at the time of the test. In 15 out of 35 cases resulting in spontaneous abortion and 15 out of the 34 pregnancies resulting in missed abortion, cytotoxic activity of the lymphocytes during pregnancy was higher than normal. Similarly, in 38 and 32.7% of the pregnancies resulting in preterm (n = 121) or low birth-weight deliveries (n = 101) respectively, we found increased lymphocyte cytotoxicity, in contrast to that being found in 5.4% of uncomplicated normal pregnancies. These data suggest that at least some pregnancy failures might be immunologically mediated.

[Our experience with the IUD (contraceptive loop) inserted immediately after interruption of pregnancy]. / Terhességmegszakítással egyidôben felhelyezett IUD-val (fogamzásgátló hurok) szerzett tapasztalataink.

PIP: In Hungary, abortion seemed to be the preferred method of family planning. A study was undertaken of 426 women aged between 20 and 30 who volunteered for IUD insertion after abortion. The Hungarian nylon IUD and the 3-dimensional Organom device were employed. For a 9 month period, 5 pergnancies were reported, in 4 of which the IUD was missing from the uterus. There were 9 expulsions, and 4 removals for bleeding and pain. 93.5% of women found the IUD satisfactory.^ieng