Rare ovarian tumours: Epidemiology, treatment challenges in and outside a network setting.

PURPOSE OF THE REVIEW: More than 50% of all gynaecological cancers can be classified as rare tumours (defined as an annual incidence of <6 per 100,000) and such tumours represent an important challenge for clinicians. RECENT FINDINGS: Rare cancers account for more than one fifth of all new cancer diagnoses, more than any of the single common cancers alone. Reviewing the RARECAREnet database, some of the tumours occur infrequently, whilst others because of their natural history have a high prevalence, and therefore appear to be more common, although their incidence is also rare. Harmonization of medical practice, guidelines and novel trials are needed to identify rare tumours and facilitate the development of new treatments. Ovarian tumours are the focus of this review, but we comment on other rare gynaecological tumours, as the diagnosis and treatment challenges faced are similar. FUTURE: This requires European collaboration, international partnerships, harmonization of treatment and collaboration to overcome the regulatory barriers to conduct international trials. Whilst randomized trials can be done in many tumour types, there are some for which conducting even single arm studies may be challenging. For these tumours alternative study designs, robust collection of data through national registries and audits could lead to improvements in the treatment of rare tumours. In addition, concentring the care of patients with rare tumours into a limited number of centres will help to build expertise, facilitate trials and improve outcomes.

Fertility and gonadal function after adjuvant therapy in women diagnosed with a malignant ovarian germ cell tumor (MOGCT) during the "cisplatin era".

PURPOSE: By self-report and serum levels of anti-Mullerian hormone (AMH) this study aims to assess post-treatment fertility after modern treatment of women with malignant ovarian germ cell tumors (MOGCT). PATIENTS AND METHODS: In 2013 a questionnaire-based survey was performed in 61 MOGCT patients diagnosed at age <40years from 1980-2009. Forty-nine of them also attended the out-patient clinic. The event of first post-treatment pregnancy ("fertility") was documented as cumulative estimates for all 61 patients and within each of 4 treatment groups: Group 1: Surgery only (n=10); Group 2: ≤3cycles of cisplatin-based chemotherapy (CBCT) (n=20); Group 3: >3cycles of CBCT (n=15) and Group 4: other adjuvant treatment (n=16). AMH was determined in 22 women <40years at survey. Statistics were based on Kaplan Meier procedure, log-rank test and a significance level p<0.05. RESULTS: At least one post-treatment pregnancy was reported by 34 of 39 MOGCT survivors who attempted motherhood after treatment. The 15-year cumulative post-treatment fertility estimate was 28% (95% CI: 26-30) for all 61 survivors and was significantly higher in patients treated with 3 or fewer cycles of CBCT (53% [95% CI: 50-55]) than those treated with more than 3cycles (20% [95% CI: 17-22]) (P=0.03). Of 22 AMH levels, two were <3pmol/l, with one women being pregnant at survey. CONCLUSION: After fertility-sparing surgery and modern cisplatin-based chemotherapy, fertility is preserved in most MOGCT survivors though dependent on the number of cycles. AMH's role as a biomarker of gonadal function seems promising but requires further research.

Prognostic factors in malignant ovarian germ cell tumours (The Surveillance, Epidemiology and End Results experience 1978-2010).

PURPOSE: To evaluate the prognostic significance of age at diagnosis, extent of the disease (EOD) and socioeconomic (SES) and sociodemographic status (civil status, residency) on cause specific survival (CSS) in patients with malignant ovarian germ cell tumours (MOGCTs). To explore the cumulative incidence of a second cancer in 10-year MOGCT survivors. PATIENTS AND METHODS: 2541 patients with MOGCT, reported to the Surveillance, Epidemiology and End Results programme (1978-2010), were identified. The above mentioned prognostic factors were assessed separately for dysgerminoma and non-dysgerminoma, using Kaplan-Meier estimates and Cox Hazards Models, providing 95% confidence intervals (95% CI). RESULTS: Five-year CSS was 97% (95% CI, 96-98%), and 92% (95% CI, 91-93%), respectively for dysgerminoma, and non-dysgerminoma. Age >40 years at diagnosis and presence of metastases were significantly associated with cause specific mortality. Among non-dysgerminoma patients, decreasing SES (hazard ratio (HR), 1.59; 95% CI, 1.11-2.28) and treatment before 1990 (HR, 2.65; 95% CI, 1.83-3.85) increased mortality. In the adjusted analysis, patients from Michigan were almost 2.5 times more likely to die from MOGCT than patients from other states (HR, 2.48; 95% CI, 1.17-5.25). Second cancer was diagnosed in 10% of 10-year survivals who underwent radiotherapy and in 2% of survivals in non-radiotherapy group (p=.002). CONCLUSIONS: Increased attention should be directed towards the management of elderly MOGCT patients and those with non-dysgerminoma histology with low SES. Radiotherapy should be avoided as much as possible. Survival differences related to residency may occur when new cancer treatments are introduced.

Malignant ovarian germ cell tumors: presentation, survival and second cancer in a population based Norwegian cohort (1953-2009).

PURPOSE: To quantify and compare survival in women with malignant ovarian germ cell tumors (MOGCTs) in Norway before and after the introduction of cisplatin-based chemotherapy (around 1980), and to explore the association between different types of treatment and the development of a second cancer. PATIENTS AND METHODS: We identified 351 patients diagnosed with MOGCTs from 1953 to 2009 in the Cancer Registry of Norway. Ovarian cancer-specific survival was calculated separately for patients diagnosed before and after 1980. Patients were divided into subgroups by histological subtype (pure dysgerminoma, malignant teratoma, other MOGCTs) and extent of disease (localized and metastatic). We estimated the cumulative incidence of a second cancer in 10-year MOGCT survivors. Kaplan-Meier estimates were used, and p<0.05 was considered significant. RESULTS: 20-Year ovarian cancer-specific survival increased from 59% (95% CI 51% to 66%) before 1980 to 88% (95% CI 83%-93%) thereafter. Significant improvement was observed in all subgroups. No second cancer was diagnosed in any of 31 10-year MOGCT survivors treated with surgery only; second cancer was diagnosed in 23 of 139 patients who underwent cytotoxic treatment (98 radiotherapy ± chemotherapy, 41 chemotherapy only; p=0.08). Patients aged >50 years had a significantly poorer ovarian cancer-specific survival than younger patients (HR=5.98, 95% CI 3.39-10.57) after adjustment for histological subtype and stage at presentation. Our results favor the treatment of patients with metastatic MOGCTs at large cancer centers. CONCLUSION: Today women with MOGCTs have an excellent prognosis if treated according to modern therapeutic principles.

High-level production of human parathyroid hormone in Bombyx mori larvae and BmN cells using recombinant baculovirus.

A full-length cDNA encoding human parathyroid hormone (hPTH) containing the prepro region was cloned into Bombyx mori baculovirus under the control of the polyhedrin promoter and polyadenylation sequences. After transfection and generation of the recombinant baculovirus, hPTH production was examined in silkworm larvae and BmN cell cultures. The larvae synthesized and efficiently secreted the correctly processed and authentic hPTH (9.4 kDa) with no sign of internal degradation. In BmN cells, the major secreted form was the correctly sized protein, but small amounts of degraded hPTH could also be detected in the medium by immunoblotting. Unlike the situation in larvae, prepro-hPTH could also be demonstrated intracellularly in BmN cells. The concentration of hPTH in the larval hemolymph was about 70 mg/l, as compared to approx. 55 micrograms/l in the medium per 7.5 x 10(6) cells. Recombinant hPTH (re-hPTH) from the hemolymph was purified by reverse-phase HPLC and subjected to chemical and biological analyses. The authenticity of the purified re-hPTH was confirmed by N-terminal sequencing, amino acid composition and a mass of 9425 Da, close to the theoretical value. The hormone showed high-affinity receptor binding and full biological potency in increasing cellular cAMP.

Human parathyroid hormone as a secretory peptide in milk of transgenic mice.

In a transgenic mouse model we have targeted the expression of recombinant human parathyroid hormone (hPTH) to the mammary gland yielding hPTH as a secretory, soluble peptide in milk. A 2.5 kb upstream regulatory sequence of the murine whey acidic protein (WAP) directed the expression of the hPTH cDNA in a fusion gene construct (WAPPTHSV2) containing the SV40 small t-antigen intron and polyadenylation site in the 3' end. Established lines of transgenic mice secreted hPTH to milk in concentrations up to 415 ng/ml. Recombinant hPTH recovered from the milk was purified by HPLC and shown to be identical to hPTH standard as analyzed by SDS-PAGE followed by immunoblotting. Expression of the WAPPTHSV2 was limited to the mammary gland as analyzed by polymerase chain reaction (PCR) and Southern blot of reversed transcribed mRNA from different tissues. hPTH is an important bone anabolic hormone and may be a potentially important pharmaceutical for treatment of demineralization disorders such as osteoporosis. We present the transgenic animal as a possible production system for hPTH.

Expression of human parathyroid hormone in mammalian cells, Escherichia coli and Saccharomyces cerevisiae.

The entire human parathyroid hormone (hPTH) cDNA gene with its natural signal and pro-region is expressed in transfected mouse mammary tumor cells (C127I cells) and Chinese hamster lung cells (DON cells) under control of the murine metallothioneine-1 promoter in a vector in which replication functions are provided by the entire genome of bovine papilloma virus type I (BPV-1). Authentic hPTH is efficiently produced by the non-endocrine cells and secreted to the growth medium without any abberant processing. Immunoblots from SDS-PAGE gels of concentrated growth medium reveal one band corresponding to intact, undegraded hPTH. Purification by reversed-phase HPLC results in a peptide with an amino acid content and N-terminal sequence identical to hPTH. For comparison, hPTH cDNA with deleted prepro-region is also expressed as secretory proteins in Escherichia coli and in Saccharomyces cerevisiae. In E. coli the vector construct is based on the staphylococcal protein A promoter employing protein A signal sequence. In S. cerevisiae a mating factor alpha expression system containing the factor alpha-signal sequence is employed. The results show that intact hPTH is secreted in addition to proteolytically cleaved fragments in both microorganisms. Thus, the signal sequences promote efficient secretion, and correct N-terminal processing of hPTH in both mammalian, bacterial and yeast cells. However, the folding characteristics of hPTH make it susceptible to internal proteolytical cleavage which appears to be species specific in yeast and E. coli.

Translocation and processing of various human parathyroid hormone peptides in Escherichia coli are differentially affected by protein-A-signal-sequence mutations.

Two staphylococcal protein-A signal sequences were constructed and tested for function in Escherichia coli, after being linked to human parathyroid hormone (hPTH) cDNAS representing the intact form (1-84 amino acids) and two N-terminal (1-37 and 1-7 amino acids) peptides. One signal sequence was identical to the wild type, and the other signal contained a deletion of 12 bp at the 3' end. The truncated hPTH cDNAs were fused at their 3' ends to IgG-binding domains (ZZ) derived from protein A in order to facilitate purification and characterization. The expression plasmid pSPTH, containing the wild-type signal sequence, secreted efficiently the intact recombinant hPTH (1-84) into the medium. Plasmids containing the truncated hPTH genes after the wild-type signal, gave rise to hPTH-ZZ hybrid proteins which were correctly processed at the N-terminal, but the major fractions appeared in the periplasmic compartment. In contrast, the plasmid pS'PTH which harboured the 4-amino-acid signal deletion did not promote a uniform secretion of intact hPTH (1-84) to the medium, but released a non-processed form both into the periplasmic compartment and to the medium. The related plasmids pS'PTH37ZZ and pS'PTH7ZZ with the mutated signal sequence gave rise to small or trace amounts of unprocessed forms of fusion proteins in the medium and periplasm, thus the secretion competence was markedly reduced. Thus, for correct N-terminal processing, we conclude that the amino acid sequence in the signal adjacent to the expressed protein, is a key determinant. However, release into the medium or periplasmic space appeared to be dependent also on protein folding, irrespective of signal-sequence cleavage. Furthermore, we observed that the peptides with the wild-type signal sequence and correct N-terminal processing, were the only forms that showed internal cleavage of hPTH. Uncleaved signals may contribute to folding characteristics of the ensuing protein and e.g., prevent internal proteolysis.

[Growth hormone and prolactin receptors belong to a new receptor family. Biological and medical aspects]. / Reseptorene for veksthormon og prolaktin tilhører en ny reseptorfamilie. Biologiske og medisinske aspekter.

The molecular structures of the receptors of growth hormone and prolactin have recently been identified by molecular cloning, and have been characterized in a number of species and different tissues. The receptors consist of one polypeptide chain with a single transmembrane region. The extracellular region contains cysteines for disulphide bonding and potential sites for glycosylations. The intracellular part which mediates the biological actions displays considerable heterogeneity of size. A high degree of homology is demonstrated between the extracellular part of these receptors and the receptors of a number of cytokines, interferons and growth factors. Together they comprise a new family of receptors called the cytokine/growth hormone/prolactinreceptor family. Their structure is reviewed, along with the actions of growth hormone and prolactin in vivo. In spite of numerous biological effects the molecular mechanisms of actions for this class of receptors are unknown, even though they convey important cell regulatory functions. The molecular analysis of growth hormone receptor has provided new medical insight on the results of growth hormone replacement therapy in persons with deficient growth.

A method for the evaluation of the efficiency of signal sequences for secretion and correct N-terminal processing of human parathyroid hormone produced in Escherichia coli.

Expression plasmids have been constructed for evaluation of different signal sequences for secretion and correct amino terminal processing of foreign proteins expressed in Escherichia coli. cDNA representing the N-terminal region (1-37) of human parathyroid hormone was inserted between DNA coding for two different forms of the signal sequence and two IgG binding domains (ZZ) derived from Staphylococcal protein A. The expression products were secreted to the periplasm and even to the growth medium and were easily purified by affinity chromatography using the ZZ part as a specific handle. Further analyses showed that the expression products were correctly processed to the mature protein hPTH(1-37)ZZ in a construct where the wild type signal sequence of Staphylococcus protein A was used. When a mutated signal sequence which lacks the normal cleavage site was employed, the fusion protein was not cleaved. Since signal sequences seem to be processed in the correct way in this system, we conclude that the general design of this type of expression vector is well suited for studying the N-terminal processing and secretion of heterologous proteins in E. coli.

Microinjection and expression of a mouse metallothionein human growth hormone fusion gene in fertilized salmonid eggs.

Using a microinjection method (Rokkones et al. 1985) deoxyribonucleic acid was introduced into fertilized salmonid eggs. The survival rate after a 28 day period was 91% for injected eggs in comparison to non-injected controls. A gene construct containing the mouse metallothionein promoter fused to the human growth hormone structural gene was microinjected either as a supercoiled plasmid or as a linear sequence. In Southern blot analysis of both 5 and 73 day old dissected rainbow trout embryos, as well as in 1 year old Atlantic salmon, the mouse metallothionein human growth hormone gene sequence was detected together with the chromosomal DNA when micro-injected as plasmid or as linear DNA. After digestion with Bam HI restriction endonuclease, the human growth hormone gene was excised from the high molecular weight DNA fraction. Transcription into human growth hormone specific RNA, as well as translation and release of human growth hormone immunoreactive protein, could be demonstrated in early embryonic stages.