Use of hecate-chorionic gonadotropin beta conjugate in therapy of lutenizing hormone receptor expressing gonadal somatic cell tumors

Improvement of cancer treatment is a major challenge of medical research. Despite the immense efforts made in the improvement of diagnosis and treatment, cancer remains a major concern and cause of morbidity and mortality. Most of the modern anti-neoplastic therapies have severe side effects, and tumor cells often develop drug resistance. There is promise in the new generation of treatments (gene therapy, immunotherapy, vaccines, etc.) that are under development, but the efficacies and side effects of such therapies have so far been disappointing. Receptor-based therapies are not new, but many normal cells also present the same receptors reducing the specificity of such approaches. Several lytic peptides have been investigated because of they appear to kill cancer cells due to changes of their membrane potential. Thus, linking receptor-specific ligands to lytic peptides is expected to augment the specificity of targeting and decrease the toxicity of lytic peptides on normal cells. One such polypeptide is hecate (an analogue to the bee venom main component, melittin) that preferentially kills cancer cells at low doses. When this peptide is fused with the 81-95 amino acid fragment of chorionic gonadotropin-beta (CGbeta) subunit (hecate-CGbeta), it targets cells expressing luteinizing hormone receptor (LHR), even at very low doses, or when LHR is expressed at low level. Our recent data showed that this peptide conjugate is efficient in destroying LHR-positive cells in xenografts and more importantly in transgenic mouse models developing LHR-positive somatic cell tumors in gonads. The mechanism of action of hecate-CGbeta after binding to LHR is destruction of cell membranes resulting in rapid cell death by necrosis with minimal side effects. This review summarizes our findings on the action of this novel peptide and considers the future potential of this family of targeting peptides in the treatment of neoplasias.

Length polymorphism of PCR-amplified genomic fragments of the Pregnancy-Associated Glycoprotein (PAG) gene family in the pig and some other domestic and wild mammals

Porcine pregnancy-associated glycoprotein genes (pPAG) are known as a multigene family, in which five members have been cloned and sequences of their cDNAs identified. Porcine PAG1 and pPAG3 genes, belonging to the pPAG1-like subfamily, both encode enzymatically inactive precursors. In contrast, cDNAs of pPAG2, pPAG4 and pPAG6 represent the pPAG2-like gene subfamily, encoding enzymatically active precursors. The objective of this study was to investigate the polymorphism of both pPAG-like gene subfamilies in the pig in comparison to other domestic species, including cattle, sheep and goat (Artiodactyla), their wild relatives (red deer and wild pig) and horse (Perissodactyla). This is the first paper indicating the polymorphism of the pPAG gene family, examined by lengths of amplified genomic fragments (PCR). Obtained PCR products were analysed in relation to five characterised cDNAs of pPAGs (pPAG1-like and/or pPAG2-like subfamilies) and according to one recognised structural exon-intron organisation of the pPAG2 gene, among at least eight pPAG2-like genes expected in the porcine genome. The highest polymorphism frequency of both pPAG1- and pPAG2-like gene subfamilies was found in the second region, exons 5 and 6 (with intron E). The length of PCR-amplified genomic fragments was approximately: 1043, 700, 600 and 193 bp. A high polymorphism frequency was found in the 3'-terminal fragment, corresponding to exons 7-9 (with introns G and H), more frequent the pPAG2-like gene subfamily. The length of PCR-amplified genomic fragments was approximately: 733, 650 and 356 bp. In contrast, PAG polymorphism was not detected in another region, encompassing exons 2-4 (with introns B and C). The length of PCR-amplified genomic fragments was approximately 279 bp in all examined genomes. In conclusion, amplification of various regions of the PAG gene family presents a relatively inexpensive PCR method of animal pre-selection with different genotypes. Such a pre-selection of animals is helpful for further gene number inquiry of the PAG gene family in each animal, then in related generations. The obtained results provide a useful background for a genetic marker preparation (by Southern analysis of the PAG family) that will presumably enable an economical early selection of young animals for effective reproduction.

[Autologous peripheral blood stem cell transplantation as an effective treatment for recurrent Hodgkin's disease]

Autologous peripheral blood stem cell transplantation (APBSCT) is a method used analogically to autologous bone marrow transplantation (ABMT) to obtain hematological reconstitution following myeloablative therapy in patients with hematological malignancies. We have now applied this procedure in two patients with recurrent high risk Hodgkin's disease. Collection of circulating stem cells mobilised with cyclophosphamide/G-CSF was performed by several leukaphereses on Fenwal 3000, with access through inferior vena cava. Nucleated cells were separated by dextran sedimentation, cryopreserved, and stored at (-) 196 degrees C. Additional marrow collection was performed in one patient. Conditioning regimen consisted of BCNU, etoposide and cyclophosphamide delivered at days -3 and -2. Collected material containing on average 3.6 x 10(8)/kg nucleated cells and 8.0 x 10(6)/kg CD34(+) cells was transfused at day 0. G-CSF was administered following transplantation to one patient to hasten the recovery. Hematological recovery was relatively quick. Neither serious adverse events nor signs of relapse were observed following transplantation. Our results supported by other's reports indicate, that APBSCT enables hematological recovery similarly to ABMT in Hodgkin's disease. The advantage of APBSCT is a possibility to collect material in patients with marrow involvement, hypoplasia or fibrosis. Outcomes obtained following APBSCT are at least as good as following ABMT. High-dose chemotherapy followed by APBSCT or ABMT should be considered in all patients with recurrent Hodgkin's disease sensitive to chemotherapy.

[Excretion of beta-2-microglobulin and Tamm-Horsfall protein in patients undergoing a conditioning regimen before bone marrow transplantation]

This study aimed assess function of renal tubules in patients undergoing conditioning regimen before bone marrow transplantation. The examined group comprised 19 patients. 13 of them underwent autologuous bone marrow transplantation (ABMT), or autologuous peripheral blood stem cells transplantation (APBSCT). These patients were treated with Cyclophosphamide (Cy) (120 mg/kg), Etoposide (1.6-1.8 g/m2) and Carmustine (400-450 mg/m2). The remaining 6 patients underwent allogenic bone marrow transplantation (BMT). They were treated with Cy 200 mg/kg or with Cy 120 mg/kg and Busulfan 16 mg/kg (doses given are the total amount or respective drugs were administered during the whole conditioning regimen). Urinary excretion of beta-2MB and THP was assessed a) before the conditioning regimen was started, b) one day before completion of it, and c) one day before bone marrow transplantation. In ABMT/APBSCT patients urinary excretion of beta-2-MG was significantly higher before and during conditioning regimen as compared with baseline value (3309 +/- 1123.7 vs 3919 +/- 1417.8 vs 246.7 +/- 50.3 mg/24h, respectively, p < 0.05). Urinary excretion of THP in these patients was significantly higher only during the conditioning regimen (90.6 +/- 14.3 vs. 30.4 +/- 6.24 mg/24h, p < 0.0002). In BMT patients conditioning regimen was followed by similar but less marked changes of urinary excretion of beta-2-MG and THP as compared with ABMT/APBSCT patients.

CONCLUSIONS

1. Conditioning regimen do influence significantly function of proximal and distal renal tubules. 2. The extent of disturbed function of renal tubules seems to depend on kind of medication that is given during the conditioning regimen.

[A favorable result of immunosuppressive therapy combined with the use of cyclosporine in a case of particularly severe Wegener's granuloma]

A case of a 38-year male patient treated for severe Wegener's granuloma has been presented. Immunosuppressive therapy including cyclophosphamide and prednisone produced a 4-week improvement followed by relapsed with advanced organ involvement (severe cardio-respiratory and renal failure). Intensive therapy with cyclosporine A and prednisone (given intravenously and next orally) carried out for 4 months produced a favourable response with complete regression of organ involvement. Actually, the patient is living in a complete remission since 4 years, and takes no drugs since 1 year.