Initiation of ovarian stimulation independent of the menstrual cycle: a case-control study

PURPOSE

In the GnRH-antagonist protocol, ovarian stimulation with gonadotropins typically commences on cycle day 2 or 3. Initiation of ovarian stimulation with a spontaneously occurring menstruation, however, poses significant organizational challenges for treatment centres and patients alike. It has previously been demonstrated in the context of fertility preservation that initiation of stimulation in the luteal phase is feasible in terms of retrieval of mature oocytes for cryopreservation. Herein, we report the extension of this concept to a routine IVF setting with the aim of establishing an ovarian stimulation protocol, which can be utilized independent of menstruation. Because of asynchrony of endometrium and embryo in such a setting, all fertilized oocytes have to be cryopreserved for a later transfer.

METHODS

This was a prospective, case-control study (trial registration: NCT00795041) on the feasibility of starting ovarian stimulation in a GnRH-antagonist protocol in the luteal phase. Inclusion criteria were: IVF or ICSI; 18-36 years; ≤3 previous IVF/ICSI attempts; BMI 20-30 kg/m(2); regular cycle (28-35 days); luteal phase progesterone >7 ng/ml at initiation of stimulation. Exclusion criteria were: PCOS, endometriosis ≥AFS III°, unilateral ovary, expected poor response. Stimulation was performed with highly purified uFSH (Bravelle®) 300 IU/day and 0.25 mg/day GnRH-antagonist starting on cycle day 19-21 of a spontaneous menstrual cycle and commencing until hCG administration when three follicles ≥17 mm were present. All 2PN stage oocytes were vitrified for later transfers in programmed cycles. Feasibility was defined as the achievement of ongoing pregnancies progressing beyond the 12th gestational week in at least 2/10 study subjects (primary outcome). Secondary outcomes were gonadotropin consumption per oocyte obtained, stimulation duration, and fertilization rates. Study subjects were matched in a 1:3 ratio with concomitantly treated control cases of similar age, BMI, and duration of infertility who were treated in a conventional GnRH-antagonist protocol with 150-225 rFSH or HP-HMG/day.

RESULTS

The study group consisted of ten subjects, mean age 31.4 years, BMI 25.4 kg/m(2), of which one had fertilization failure. Mean stimulation duration was 11.7 (SD 1.6) vs. 9.1 (SD 1.3) days, mean cumulative FSH dose was 3,495.0 (SD 447.5) vs. 2,040.5 (SD 576.2) IU, and mean number of oocytes was 8.8 (SD 5.0) vs. 10.0 (SD 5.4) in study vs. control group, respectively. Per follicle ≥10 mm, the cumulative FSH dose was 274.5 (SD 130.8) IU vs. 245.2 (SD 232.3) IU in study and control groups, respectively. Cumulative ongoing pregnancy rates were 1/10 (10 %) and 6/30 (20.0 %) in study and control group, respectively (difference: 10 %, 95 % confidence interval of the difference: -29.2-22.2 %, p = 0.47). Fertilization rate was similar between groups, with 63.5 % (SD 32.9) in the study and 61.3 % (SD 26.7) in the control group, respectively. Serum estradiol levels were significantly lower on the day of triggering final oocyte maturation with 1,005.3 (SD 336.2) vs. 1,977.4 pg/ml (SD 1,106.5) in study and control group, respectively. Similarly, peak estradiol biosynthesis per growing follicle ≥10 mm was lower in the study group (134 pg/ml, SD 158.4 vs. 186.7 pg/ml, SD 84.7).

CONCLUSIONS

Per retrieved oocyte, a nearly threefold higher dose of FSH had to be administered when ovarian stimulation had been initiated in the luteal phase. Furthermore, the present study casts doubt on the efficacy of initiating ovarian stimulation in the luteal phase in terms of pregnancy achievement. Thus, this concept is currently not feasible for routine use, and it should also be explored further before using it at larger scale in the context of emergency stimulation for fertility preservation.

Serum 25-hydroxyvitamin D levels in patients with vulvar cancer

BACKGROUND

The anticarcinogenic potential of vitamin D 25(OH)D has been attributed to the inhibition of proliferation of cells from different carcinomas. Reduced serum levels of 25(OH)D are associated with an increased incidence of various types of cancer. The influence of serum 25(OH)D on the incidence and outcome of patients with vulvar cancer is unknown.

PATIENTS AND METHODS

The serum 25(OH)D levels in 24 patients with vulvar cancer and 24 age-matched cancer-free patients was investigated. The blood samples were collected between October 2009 and September 2010 and time of blood collection of each patient and control was matched to avoid seasonal variations between the pairs.

RESULTS

The median 25(OH)D serum levels in the under 50 year old group of patients were significantly lower in the vulvar cancer group than the controls. The younger cancer group also had an age-related trend of lower median serum level than the older population. In the control population the trend was vice versa, yet this finding was not statistically significant.

CONCLUSION

Serum 25(OH)D has a possible role in the pathogenesis and progression of vulvar cancer, but further investigations of the association of vitamin D and vulvar cancer as well as regarding its influence on patient survival and quality of life are warranted in the future.

Expression of prostaglandin- and vitamin D-metabolising enzymes in benign and malignant breast cells

BACKGROUND

Cyclooxygenase-2 (COX-2) plays a crucial role in prognosis of malignancy and has been associated with carcinogenesis, particularly neoangiogenesis and tumor progression. 15-Hydroxyprostaglandin dehydrogenase (15-PGDH) is described as a tumour suppressor in cancer. The antiproliferative effects of calcitriol [1,25(OH)(2)D(3)] mediated via the vitamin D receptor (VDR) render vitamin D a promising target in breast cancer therapy.

MATERIALS AND METHODS

The expression of prostaglandin (PG)-metabolizing enzymes, vitamin D-metabolising enzymes and VDR were determined in benign and malignant breast cell lines using western blot analysis.

RESULTS

We detected an inverse correlation between the two types of metabolism, a reduced VDR expression in the malignant breast cell lines, and therefore an insufficient induction of 24-hydroxylase in the malignant cells.

CONCLUSION

We suggest the possibility of dysregulation of vitamin D-metabolizing enzymes in malignant breast cell lines.

Correlation of prostaglandin metabolizing enzymes and serum PGE2 levels with vitamin D receptor and serum 25(OH)2D3 levels in breast and ovarian cancer

BACKGROUND

Vitamin D and its active form calcitriol have multiple effects in cancer cells, such as anti-proliferative effects, induction of apoptosis and cell cycle arrest. There is a link between vitamin D metabolism and inflammatory processes, which should be considered in cancer therapy. An association between these two types of metabolism is also observed in breast and ovarian cancer. These inflammatory processes are based on an increase of cyclooxygenase-2 (COX-2) activity. The current study aimed to evaluate the expression of prostaglandin-metabolising enzymes COX-2 and 15-hydroxyprostaglandin-dehydrogenase (15-PGDH) along with the vitamin D receptor (VDR) in benign and malignant breast and ovarian tissues.

PATIENTS AND METHODS

VDR, COX-2, 15-PGDH and prostanoid receptor E2/E4 expression were measured in tissues by western blot analysis. Additionally, plasma 25(OH)(2)D(3) and PGE(2) levels were measured in healthy patients and cancer patients.

RESULTS

We detected an elevated COX-2 and inversely a lowered VDR expression in cancer patients compared to healthy women. Breast cancer patients diagnosed during wintertime had a significantly lower serum level of 25(OH)(2)D(3); PGE(2) serum levels were higher in both types of cancer.

CONCLUSION

These results support the idea of a link between prostaglandin and vitamin D metabolism in regards to their influences on breast and ovarian cancer.

Vitamin D receptor expression in patients with vulvar cancer

The anticarcinogenic potential of vitamin D is attributed to antiproliferative and prodifferentiative effects on cells for a wide variety of carcinomas. The biological effects of 1,25(OH)(2)D (calcitriol) are mediated through a soluble receptor protein termed vitamin D receptor (VDR). However, thus far there have been no studies evaluating the association between VDR expression and vulvar cancer. Using immunohistochemical analysis, VDR expression was evaluated separately in the nucleus, cytoplasm and membrane, in vulvar cancer samples and adjacent non-pathological vulvar tissue from 48 squamous cell carcinoma patients with no prior therapy, and the association between VDR and overall survival was investigated. Overall, among the 48 vulvar cancer cases, nuclear and cytoplasmic VDR expression was present in 47 (97.9%) and 23 (47.9%) cases respectively. The median nuclear VDR expression was significantly higher as compared to the cytoplasmic VDR in the vulvar cancer tissue. No significant correlation between VDR values and the age of the patients was detected. Nuclear and cytoplasmatic VDR in the vulvar cancer tissue were also compared according to the tumor size, and no significant association between mean tumor VDR and tumor size was detected. There was no association between cytoplasmatic VDR expression and OS, but better OS was observed in patients with reduced nuclear VDR expression as compared to those with high VDR expression. VDR may be considered as a useful pathological marker.

Influence of calcitriol on prostaglandin- and vitamin D-metabolising enzymes in benign and malignant breast cell lines

BACKGROUND

Cyclooxygenase-2 (COX-2) is a potential molecular prognostic factor for breast cancer, and calcitriol [1,25(OH)(2)D(3)], the biologically active form of vitamin D, is a promising target in breast cancer therapy.

MATERIALS AND METHODS

The influence of calcitriol on the proliferation and the effects of calcitriol on the expression of prostaglandin- and vitamin D-metabolising enzymes were examined in benign and malignant breast cells.

RESULTS

Calcitriol inhibited the proliferation of MCF-10F and MCF-7 cells but not of invasive MDA-MB-231 cells and reduced the expression of COX-2 and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in the benign breast cell line MCF-10F. Furthermore, dysregulation in vitamin D-metabolising proteins was detected, especially in MDA-MB-231 cells.

CONCLUSION

These results suggest dysregulation of vitamin D metabolism and a lack of a possible influence of calcitriol on the metabolism of prostaglandins in the malignant breast cell lines.

P5-07-02: Could the Combination of COX-2 Inhibitor and Calcitriol Be a New Chemopreventive Approach To Decrease the Incidence of Breast Cancer?

Background

COX-2 is a potential molecular prognostic factor for breast cancer and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is described as a tumour suppressor in cancer. The antiproliferative effects of calcitriol (1,25(OH)2D3) mediated via the vitamin D receptor (VDR) render vitamin D a promising target in breast cancer therapy.

Material and Methods: The expression of the prostaglandin (PG) metabolising enzymes (COX-2, 15-PGDH), the PG receptors, the vitamin D metabolising enzymes (1-alpha-hydroxylase, 24-hydroxylase) and the VDR were determined in benign and malignant breast cell lines as well as in normal and malignant breast tissue. Measurement of PGE2 and 25(OH)2D3 serum level in healthy women and breast cancer patients was performed in winter and summertime. Additionally, the influence of calcitriol on cell proliferation was determined. In addition we examined the effect of calcitriol on the enzyme expression.

Results: We found an inverse correlation between the expression of the PG metabolising enzymes with the VDR as well as with the vitamin D metabolising enzymes by investigating the tissue samples. Moreover, we detected an inverse correlation between the PGE2 and 25(OH)2D3 serum level in breast cancer patients during wintertime. Furthermore the PG receptors were associated with an increased carcinogenesis. The breast cell experiments presented a dysregulated vitamin D metabolism, especially in the invasive breast cell line. Calcitriol showed an antiproliferative effect only in the benign but not in the malignant cell lines, and the expression of COX-2 and 15-hydroxyprostaglandindehydrogenase was influenced by calcitriol only in the benign breast cell line.

Conclusions: These results suggest a link between vitamin D and PG metabolism and therefore a possible synergism between COX-2 inhibition and calcitriol in breast cancer cells. For the first time, we could show an inverse correlation between the two metabolisms in breast cancer on different levels. Thus, the chemopreventive combination of calcitriol and/or vitamin D analogue with a COX-2 inhibitor might decrease the incidence of breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-07-02.

Vitamin D, calcidiol and calcitriol regulate vitamin D metabolizing enzymes in cervical and ovarian cancer cells

BACKGROUND

The vitamin D metabolizing enzymes 25-, 1α- and 24-hydroxylase are expressed in malignant cells of the cervix and the ovaries. The aim of this study was to obtain further information about the regulation of the aforementioned enzymes by vitamin D, calcidiol and calcitriol in cervical and ovarian cancer.

MATERIALS AND METHODS

The human cervical adenocarcinoma cell line HeLa and the human ovarian adenocarcinoma cell line OVCAR-3 were incubated with vitamin D, calcidiol and calcitriol. The influence of vitamin D and its metabolites on the expression of 25-, 1α- and 24-hydroxylase was assessed by real-time RT-PCR.

RESULTS

Calcitriol significantly increased the 24-hydroxylase mRNA levels in HeLa and OVCAR-3 cells. The expression of 25- and 1α-hydroxylase was not regulated in a statistically significant manner.

CONCLUSION

These results suggest that in HeLa as well as OVCAR-3 cell lines, the metabolism of vitamin D is regulated via the expression of the catabolizing 24-hydroxylase.

Vitamin D-1alpha-hydroxylase and vitamin D-24-hydroxylase in benign and malign breast tissue

BACKGROUND

It is known that 1,25(OH)2D3 can be metabolized to 1,24(OH)2D3 in breast tissue. This tissue-specific expression of 24-OHase may act as a pivotal link between vitamin D status (25(OH)D3 level) and the anticancer effects of 1,25(OH)2D3. Different expressions of the enzymes of vitamin D metabolism are found in breast cancer cells and tissues, and alternative splicing may play a role in biological functions and may cause tissue-specific variations. We describe the expression of vitamin D-1alpha-hydroxylase and vitamin D-24-hydroxylase in benign and malign breast tissues. We estimated that alternative splicing of the enzymes would lead to a catalytically dysfunctional product and may lead to a lower reduction of the target protein.

MATERIAL AND METHODS

Expression of 1alpha-OHase and 24-OHase RNA and protein was assessed using a real-time polymerase chain reaction (RT-PCR) and on protein level by Western blot in benign and malign breast tissue samples.

RESULTS

In breast cancer tissue the expression of 1alpha-OHase and 24-OHase were reduced significantly compared to benign breast tissue.

CONCLUSION

The results described above do not support results of previous studies. Alternative splicing of 1alpha-OHase and 24-OHase may regulate the levels of active enzyme but is more likely due to different cell types in samples with the result of testing a variety of tissue samples not purified benign and malign breast cancer cells. The significance of smaller variants in cells has not been clarified either, but it is known that they are not able to use 25(OH)D3 as a substrate to generate 1,25(OH),D3.

Die Diagnostik der männlichen Infertilität – ein wichtiger Bestandteil der Reproduktionsmedizin

Aufgrund des erheblichen Anteils der männlichen Infertilität an der ungewollten Kinderlosigkeit müssen Andrologen in jedes reproduktionsmedizinische Team integriert sein, so dass die Kinderwunschbehandlung und -diagnostik immer eine interdisziplinäre Aufgabe ist. Aufgrund der spontanen Schwangerschaften auch bei infertilen Paaren ist es die Hauptaufgabe der reproduktionsmedizinischen Diagnostik die weitere therapeutische Weichenstellung auf eine solide diagnostische Basis zu stellen. Anerkannte Richtlinien für die standardisierte Diagnostik der männlichen Infertilität fehlen meist. Eine minimale andrologische Diagnostik sollte bei allen infertilen Paaren nach spätestens einem Jahr ungeschützten Geschlechtverkehrs erfolgen bzw. gegebenenfalls früher, falls andrologische oder gynäkologische Risikofaktoren für eine Infertilität vorliegen. Bestandteile der minimalen andrologischen Diagnostik sind die Erhebung der reproduktionsmedizinischen Anamnese und eine zweimalige Ejakulatuntersuchung nach den aktuell gültigen WHO-Kriterien. Eine komplette andrologische Untersuchung durch einen Andrologen sollte grundsätzlich erfolgen, insbesondere bei Patienten mit einer auffälligen andrologischen Anamnese, bei Auffälligkeiten in der Ejakulatanalyse, bei idiopathischer Paarinfertilität und bei Patienten mit einem behandelten weiblichen Faktor und persistierender ­Infertilität. Elementarer Bestandteil einer kompletten andrologischen Untersuchung ist die Durchführung einer kompletten körperlichen und genitalen Untersuchung. Basierend auf den Ergebnissen dieser Untersuchungen sollten gegebenenfalls weitere diagnostische Maßnahmen durchgeführt werden, wie Hormonuntersuchungen, eine sonographische Untersuchung der Skrotalorgane und der Prostata und Samenblasen, die Durchführung genetischer Untersuchungen sowie eine diagnostisch/therapeutische Hodenbiopsie. Diese Untersuchungsgänge führen zu einer Diagnose, auf der das therapeutische Vorgehen basieren muss.

25-Hydroxyvitamin D3 1alpha-hydroxylase splice variants in benign and malignant ovarian cell lines and tissue

Calcitriol is judged to have a positive effect on control of the immune system, cell growth and differentiation and therefore, the prevention of cancer genesis. The aim of this study was to detect any possible differences in the 25-hydroxyvitamin D-1alpha-hydroxylase (1alphaOHase)-expression between benign and malignant ovarian tissue and cell lines. The analysis was conducted quantitatively, by means of nested "touchdown" PCR and Western blot, and qualitatively, with the use of real-time PCR and Western blot. The gene structure was sequenced. Compared to the benign cell line, the malignant cell lines showed a significantly higher expression of 1alphaOHase at the RNA level. A statistically lower expression of the 1alphaOHase protein was found in the malignant tissue. In the malignant cell lines and tissues, divergent bands were detected, which led to various splice variants on sequencing. Their increased expression in malignancy is possibly bound to the reduction of enzyme activity, which may lead to the genesis of ovarian cancer. In the future, preventive and therapeutic activities may result from these findings.

Expression of prostaglandin metabolising enzymes COX-2 and 15-PGDH and VDR in human granulosa cells

BACKGROUND

Prostaglandins (PGs) within the periovulatory follicle are essential for various female reproductive functions such as follicular development and maturation. In animal models, granulosa cells express the PG synthesizing enzyme cyclooxygenase-2 (COX-2) and the PG inactivating enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH). First references suggest a correlation between vitamin D and prostaglandin metabolism through the impact of 1,25(OH)2D3 (calcitriol) on the expression of COX-2 and 15-PGDH.

MATERIALS AND METHODS

The expression of COX-2, 15-PGDH and the vitamin D receptor (VDR) in human granulosa cells (COV434, hGC and HGL5), which were originally isolated from different stages of follicular maturation, was determined by real-time PCR (RT-PCR) and Western blot analysis.

RESULTS

A positive correlation of COX-2 and VDR protein was found in the COV434 and HGL5 cells and an inverse correlation of 15-PGDH and VDR protein levels in all the investigated cell types.

CONCLUSION

There may be a link between VDR, associated target genes and prostaglandin metabolism in human follicular maturation and luteolysis.

Expression of 25-hydroxyvitamin D3-24-hydroxylase in benign and malignant ovarian cell lines and tissue

Calcitriol (1,25-dihydroxyvitamin D3, 1,25(OH)2D3) plays a pivotal role in maintaining calcium and phosphate homeostasis. Aside from that, it supports the native and attenuates the acquired immune system and has positive effects on cell growth, differentiation and the prevention of carcinogenesis. The goal of this study was to detect possible differences in the expression of the calcitriol-degrading enzyme 24-hydroxylase (24-OHase) between malignant and benign ovarian cell lines and tissue. The analyses were based on real-time PCR, nested touchdown PCR and Western blot. When compared to benign granulose GLZ cells, the malignant HGL5 cells showed a significantly higher 24-OHase expression at the protein level (p<0.01). In the malignant ovarian tissue, the expression was significantly higher in RNA (p<0.001), but lower at the protein level (p<0.01). An increased 24-OHase expression could indicate a decrease in available calcitriol.

Vitamin D-24-hydroxylase in benign and malignant breast tissue and cell lines

Tissue-specific expression of 25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-OHase) and vitamin D-hydroxylase (24-OHase) may act as the pivotal link between 25-hydroxyvitamin D3 (25(OH)D3) serum levels and the anticancer effects of 1,25-dihydoxyvitamin D3 (1,25(OH)2D3) and alternative splicing of the enzymes may regulate their biological function. The expression of 24-OHase in cells and breast tissue was investigated and its splice variants were detected. The expression of 24-OHase RNA and protein was assessed by RT-PCR followed by Western blot. The expression of 24-OHase was reduced by about 57% in MCF-7 breast cancer cells, compared to MCF-10F benign breast cells. In the Western blot, a signal at 56 kDa was found and further bands were detected at 42 and 44 kDa. In the breast cancer tissue, the expression of 24-OHase was reduced by about 58% compared to benign tissue. However, in the Western blot, only one signal was found in the benign tissue at 56 kDa, while in malignant tissue, a further band was detected at 40 kDa. Alternative splicing of 24-OHase may lead to a catalytically dysfunctional enzyme and may lead to less reduction of the target protein.

Prostaglandin metabolizing enzymes in correlation with vitamin D receptor in benign and malignant breast cell lines

BACKGROUND

The antiproliferative effects of calcitriol (1,25(OH)2D3) mediated via the vitamin D receptor (VDR), render the biologically active form of vitamin D a promising target in breast cancer therapy. Furthermore, breast cancer is associated with inflammatory processes based on an up-regulation of cyclooxygenase-2 (COX-2) expression, the prostaglandin E2 (PGE2) synthesizing enzyme. The PGE2 metabolizing enzyme, 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is described as a tumor suppressor in cancer. First references suggest a correlation between vitamin D and prostaglandin metabolism through the impact of 1,25(OH)2D3 on the expression of COX-2 and 15-PGDH.

MATERIALS AND METHODS

The expression of VDR, COX-2 and 15-PGDH in benign MCF-10F and malignant MCF-7 breast cells was determined by real-time PCR (RT-PCR) and Western blot analysis.

RESULTS

Although the RT-PCR data were divergent from those obtained from the Western blot analysis, the COX-2 protein expression was MCF-7 2-fold higher in the MCF-7 compared to the MCF-10F cells. Moreover, a correlation of 15-PGDH to VDR by RT-PCR was found in both cell lines. The VDR protein levels were inversely correlated to the 15-PGDH protein levels and revealed that the MCF-10F cells had the highest VDR expression.

CONCLUSION

A possible link between VDR-associated target genes and prostaglandin metabolism is suggested.

Tartrate-resistant acid phosphatase (TRAP) as a serum marker for bone resorption in breast cancer patients with bone metastases

BACKGROUND

A novel immunoassay specific for the osteoclast-produced tartrate-resistant acid phosphatase TRAP isoform 5b was developed some years ago. By means of this assay, the usefulness of serum TRAP in monitoring the response to palliative treatment with clodronate in breast cancer patients with bone metastases was studied. Serum TRAP was examined for correlation with the activity of bone osteoclasts in these patients.

MATERIALS AND METHODS

Seventeen patients took part in this study taking 1600 mg clodronate daily as a tablet for five months. Eleven of these patients were evaluated.

RESULTS

TRAP activity correlated well with the grade of bone metastases and with the number of locations in the body. During the therapy with clodronate, TRAP activity in serum decreased.

CONCLUSIONS

We conclude that the measurement of TRAP is useful in monitoring treatment with bisphosphonate clodronate in patients with bone metastatic breast cancer.

25-Hydroxyvitamin D3 1alpha-hydroxylase splice variants in breast cell lines MCF-7 and MCF-10

BACKGROUND

It is known that 25(OH)D3 can be metabolized to 1,25(OH)2 D3 by 1alpha-OHase in breast tissue. This tissue-specific expression of 1alpha-OHase may act as the pivotal link between vitamin D status (25(OH)D3 levels) and the anticancer effects of 1,25(OH)2 D3. Alternative splicing frequently occurs in breast cancer cells; different splice variants of a given protein can display different biological functions and may cause tissue-specific variations. With this study it is the first time that expression and alternative splicing of 1alpha-OHase in the human breast cancer cell line MCF-7 and thebenign breast cell line MCF-10A are described.

MATERIALS AND METHODS

Expression of 1alpha-OHase RNA and protein was assessed using a real-time polymerase chain reaction (RT-PCR). The expression of 1alpha-OHase splice variants was detected by a highly specific PCR that combines nested and touchdown PCR. To determine which variants are translated in protein western blot analysis was carried out.

RESULTS

The expression of 1alpha-OHase was found to be 1.25-fold higher in MCF-7 compared to MCF-10A cells. In MCF-10A cells, at least 6 splice variants were detected whereas MCF-7 showed no or marginal expression levels of these variants. In MCF-7 cells the antibody detected a signal at 56 kDa corresponding to the size of normal 1alpha-OHase protein. In MCF-10A cells this signal was weaker. In western blot analysis at least two smaller variants at 45 kDa were found in MCF-7 cells. In MCF-10A cells at least 6 proteins between 37 and 56 kDa were detected with an only faint signal.

CONCLUSION

We propose that alternative splicing of 1alpha-OHase can regulate the level of active enzyme. Splice variants may lead to a reduction of the protein. The significance of the smaller variants in MCF-7 cells has not been clarified either, but it is known that they are not able to use 25(OH)D3 as a substrate to generate 1,25(OH)D3. In MCF10A cells, more splice variants were identified, it may be that malignant cells contain inactive variants. How far they show a reduced activity remains unclear as no activity measurements were performed.

Expression of splice variants of 1alpha-hydroxylase in mcf-7 breast cancer cells

1,25-Dihydroxyvitamin D(3) (calcitriol) is the most active natural metabolite of Vitamin D(3). It has strong antiproliferative and differentiating effects on various cell types including breast cancer cells. 25-Hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase, CYP27B1) is one of the key enzymes in the formation of calcitriol. It has been found in breast cancer cells suggesting an autocrine regulation of formation of calcitriol in these cells. Alternative splicing of the encoding genes for this enzyme can possibly play a role in regulating the enzyme level and can explain tissue specific variations of 1alpha-hydroxylase activity. Splice variants containing intron 1 may encode for truncated proteins with deletion of protein domains which are essential for its enzymatic activity. In order to obtain more information on the abundance of 1alpha-hydroxylase splice variants, we performed a highly specific nested touchdown PCR in MCF-7 cells. The full-length sequence of 1alpha-hydroxylase and two different splice variants of this enzyme containing intron 1 were isolated. By Western blot technique we then confirmed the protein products of the full-length enzyme and its splice variants. We hypothesize that that the expression of splice variants can lead to a quantitatively lower expression of the mRNA of the full-length enzyme. The abundance of less active 1alpha-hydroxylase protein variants can alter the local synthesis of calcitriol in the cells and may explain variations of enzymatic activity in different cells and tissues.

Expression of 25 hydroxyvitamin D3-1alpha-hydroxylase in human endometrial tissue

1,25(OH)(2)D(3) (calcitriol) has been shown to play an important role in cell proliferation, differentiation and immune responsiveness. The enzyme responsible for calcitriol synthesis 25 hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-OHase) has been reported in many human tissues. The aim of this study was to investigate the expression of 1alpha-OHase in gynaecological tissues. Using a highly specific nested touchdown PCR we examined the expression of 1alpha-OHase in normal and malignant endometrial tissue and in human endometrial Ishikawa cells. In addition, we analyzed the protein expression of 1alpha-OHase by Western blot. The expression of 1alpha-OHase in normal and malignant endometrial tissue and Ishikawa cells was detected and splice variants of the enzyme in Ishikawa cells were identified. These data suggest an alternative splicing of 1alpha-OHase in malignant endometrial tissue and cells. We postulate that the expression of 1alpha-OHase gene variants may contribute to the antiproliferative effects of calcitriol. In conclusion, the modulation of the 1alpha-OHase opens up a new target for vitamin D(3) related therapies in endometrial cancer.

Feasibility and efficacy of chemotherapy with gemcitabine mono and with paclitaxel/mitoxantron in gynaecological cancers

In this prospective study 32 patients with advanced gynaecologic tumours were treated with different schemes of chemotherapy: 15 received a combination of paclitaxel (100 mg/m2/week)/mitoxantron (6 mg/m2/every second week). Seventeen patients were treated with gemcitabine (100 mg/m2) in two different schedules, and the time of infusion was 2,2-3,3 hours or 30 minutes, respectively. Tolerability and efficacy were observed. The most common reason for reduction of the dosage or for cycle delay in the combined scheme was neutropenia. The response rate was 82%. The median overall survival was 30 weeks since beginning of the chemotherapy and 15 weeks after the last infusion. Gemcitabine in the shorter scheme led to a higher median dose rate. Toxic skin effects and hematological adverse events led to dose reduction and cycle delay in 90% of the infusions in the longer scheme. The response rate was 76%. The overall survival was one to 69 weeks with a median survival of 22 weeks. The advantages of the shorter scheme were confirmed.

Metabolism of vitamin D3 in the placental tissue of normal and preeclampsia complicated pregnancies and premature births

The aim of this study was to analyze the hormonal basis for low 1,25(OH)2D3 circulating levels in patients with preeclampsia and/or preterm deliveries. The activity and expression of the 1 alphaOHase, 25-OHase, 24-OHase and VDR in the placental tissue of normal pregnancies, preeclampsia-complicated pregnancies and premature births were investigated. The mRNA of the enzymes was detected in the placental tissue from preeclamptic pregnancies and compared to those of normal placental tissue. Real time PCR analysis showed a significant increased 1 alpha-OHase gene expression in preeclamptic patients, and the gene expression of 24-OHase was significantly decreased. With regard to the 25-OHase the median value of the normal placental tissue was significantly higher than in the placental tissue of preeclamptic patients. The real time analysis of all target genes also showed significant differences in normal placental tissue compared to placental tissue from premature births (VDR: p = 0.041; 1 alpha-OHase: p = 0.013; 24-OHase: p = 0.007; 25-OHase p = 0.027). Our observation of reduced VDR expression on mRNA level in placental tissue indicates a possible dependence of the modulation of VDR expression from proliferation and differentiation processes. It can be speculated whether the down-regulation of VDR in the examined placenta cells was the result of an altered production of calcitriol by these cells. We found a significantly higher 1 alpha-OHase-expression in the placental tissue of pregnant women with preeclampsia or preterm birth compared to healthy pregnant women, whereas the expression of 25-OHase was significantly reduced. These results correlate with other studies and support the significance of the placenta regarding metabolism malfunctions as they were observed in the calcium metabolism for preeclampsia. That a placenta with preeclampsia expresses less 1 alpha-OHase-mRNA and shows less 1 alpha-OHase-activity than in placental samples of inconspicuous placentae, can be granted as a specific alteration in the placental ability to synthesize adequate amounts of 1,25(OH)2D3.

Modulation of MAPK ERK1 and ERK2 in VDR-positive and -negative breast cancer cell lines

1alpha-25-Dihydroxyvitamin D3 (calcitriol), the biologically active metabolite of vitamin D, is known to regulate calcium and phosphate levels in bone metabolism. It is also known to influence proliferation and differentiation in carcinoma cells mediated by the vitamin D receptor (VDR). The antiproliferative effects of calcitriol are believed to be mediated by the nuclear pathway via binding the activated receptor to vitamin D-responsive elements. This induces the vitamin D-responsive genes. Another possible pathway might be the MAPK-cascade or rapid response pathway. The interaction of calcitriol and the MAP-kinase-cascade was evaluated on VDR-positive MCF-7 cells and VDR-negative MDA-MB-231 breast cancer cells. The cells were incubated with calcitriol solution at 10(-7) M and 10(-9) M, or ethanol as controls, for up to 48 h. The effects of calcitriol were measured by semi-quantitative Western blotting. Calcitriol stimulated the MAP-kinases ERK1 and ERK2. A biphasic activation was found for calcitriol in VDR-positive cells after incubation for 5 to 20 min and from 2 to 24 h. However, early activation of ERK1 and ERK2 was also demonstrated in VDR-negative cells. In the controls, ethanol also induced the MAPK-cascade at 5 to 10 min. Calcitriol induction was demonstrated after incubation from 2 to 24 h. In conclusion, it seems that the early induction of the MAPK-cascade was independent of the VDR. A calcitriol-induced MAPK activation was shown after 4 h, which may have been caused by activation of the nuclear receptor pathway.

Vitamin D--metabolism in the human breast cancer cell line MCF-7

BACKGROUND

The three main vitamin D metabolizing enzymes, vitamin D3-25-hydroxylase (25-OHase, 25-hydroxylase), 25-hydroxyvitamin D3-1alpha-hydroxylase (1alpha-OHase, 1alpha-hydroxylase) and 25-hydroxyvitamin D3-24-hydroxylase (24-OHase, 24-hydroxylase), have been described in malignant breast tissue. This in vitro study aimed to obtain more information regarding the regulation of these enzymes in the human breast cancer cell line MCF-7.

MATERIALS AND METHODS

Vitamin D receptor (VDR)- positive MCF-7 cells in culture were stimulated with the vitamin D metabolites vitamin D3, 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 for 24, 48; 72 and 96 hours in physiological and supraphysiological concentrations. The expressions of 25-hydroxylase, 1alpha-hydroxylase and 24-hydroxylase and their changes after stimulation were assessed by real-time PCR.

RESULTS

The expression of 25-hydroxylase was slightly influenced by vitamin D3. The expression of 1alpha-hydroxylase was induced after stimulation with vitamin D3 and 25-hydroxyvitamin D3. Stimulation with 1,25-dihydroxyvitamin D3 markedly increased the expression of 24-hydroxylase time- and dose-dependently.

CONCLUSION

Our results demonstrated that MCF-7 cells are able to regulate the expression of 24-hydroxylase. This might be a mechanism for these tumor cells to protect themselves against the antiproliferative and apoptosis-inducing effects of calcitriol.

Analysis of 25-hydroxyvitamin D3-1alpha-hydroxylase in normal and malignant breast tissue

BACKGROUND

The presence of extra-renal 25-hydroxyvitamin D3 [25(OH)D3]-1alpha-hydroxylase (1alpha-OHase) has been reported in several cell types including prostate and colon cancer cells. Additionally, alterations in the local production of 1alpha,25-dihydroxyvitamin D [1alpha,25(OH)2D3] have been implicated in the tumorigenesis of these malignancies. The aim of this study was to analyze whether normal breast tissue or breast cancer cells expressed 1alpha-OHase and to evaluate whether breast tissue possessed the capacity to produce 1alpha,25(OH)2D3 from 25(OH)D3.

MATERIALS AND METHODS

Total RNA was extracted from normal breast tissue (n = 11), breast carcinomas (n = 12) and cultured MCF-7 breast cancer cells for real-time (LightCycler using specific hybridization probes) and conventional PCR analysis.

RESULTS

mRNA for 1alpha-OHase was detected in breast cancer tissue and in MCF-7 breast cancer cells. Interestingly, the mRNA levels for 1alpha-OHase were significantly increased in breast cancer compared to normal breast tissue. When the MCF-7 cells were treated with 1alpha,25(OH)2D3, cell proliferation was inhibited in a dose-dependent manner. Incubation of the MCF-7 cells with [3H]-25(OH)D3 resulted in its conversion to [3H]-1,25(OH)2D3. The 1alpha-OHase activity in the MCF-7 cells was blocked by a specific cytochrome P450 inhibitor, clotrimazole.

CONCLUSION

The data suggest that at least breast cancer cells expressed 1alpha-OHase mRNA and, therefore, might have the ability to synthesize 1alpha,25(OH)2D3 within the cells. The local production of 1alpha,25(OH)2D3 might play an important role in regulating the proliferation and differentiation of breast cells. We hypothesize that alterations in the local production of 1alpha,25(OH)2D3 may be involved in the tumorigenesis of breast cancer. Additionally, breast cancer may be a target for treatment with precursors of biologically-active vitamin D analogs.

Presentation of splice variants of 1-alpha-hydroxylase in MCF-7 breast cancer cells

20097

Background: Calcitriol (1,25-dihydroxyvitamin D3) is the most active metabolite of vitamin D. It is known for its antiproliferative and differentiating effects on many cell populations including MCF-7 and other breast cancer cells. 1α-hydroxylase (CYP27B1) one of the key enzymes has been found in breast cancer cells suggesting an autocrine regulation of producing calcitriol. An alternative splicing of the encoding genes for the1α-hydroxylase might play a role in regulating enzyme levels and can explain tissue specific variations of the enzyme activity. Splice variants containing intron 1 may encode for truncated proteins with deletion of protein domains which are essential for its enzymatic activity. Methods: In order to obtain more information on the abundance of 1α-hydroxylase splice variants, we performed a highly specific nested touchdown PCR in MCF-7 cells. The protein products of the full length enzyme and its slice variants were confirmed by Western Blot. Results: The full length sequence of 1α-hydroxylase and two different splice variants including intron 1 were isolated. Conclusion: We hypothesize that the expression of the splice variants can lead to a quantitatively lower expression the mRNA of the full length enzyme. The abundance of less active 1α-hydroxylase protein products can alter the local synthesis of calcitriol in the cells and may explain variations of enzymatic activity in different cells and tissues.

No significant financial relationships to disclose.

Endometrial stromal sarcomas--a retrospective analysis of 11 patients

BACKGROUND

Endometrial stromal sarcoma (ESS) is a malignant tumour with its origin in the endometrial stroma. Little is known about the pathogenesis, risk factors, optimal therapy or outcome of this disease.

PATIENTS AND METHODS

Eleven patients with ESS, treated between 1972 and 1996, are reported on. The hospital records of all the patients, including pathology and operative reports, were reviewed and information on treatment, recurrence and survival was obtained.

RESULTS

The mean age of our patients was 56.6 years. The main symptom was abnormal vaginal bleeding. Most patients were diagnosed at FIGO stage I. Treatment modalities were surgery, radiation and, in one patient, chemotherapy. The median follow-up time was 42.1 months; 27.3% of the patients had local recurrence. The 1-year, 2-year and 5-year survival rates were 36.3%, 18.1% and 9.1%, respectively.

CONCLUSION

ESS is a uterine sarcoma with a difficult differential diagnosis. Patients are frequently diagnosed in an early tumour stage but still experience local or distant recurrence. The prognosis is poor, with early recurrence and low long-time survival rates. The treatment includes surgery and adjuvant radiation, with endocrine therapy being a promising new approach. In order to obtain more information about the pathogenesis of the tumour and to find the optimal therapy, it is necessary that studies, even with small numbers of patients, are undertaken.

[Metastatic breast cancer: options for metastasectomy]

Usually, the therapy of metastatic breast cancer consists of chemotherapy or endocrine therapy, because even in the case of isolated metastases in one organ, diffuse tumor cell dissemination exists, so that local surgical treatment does not seem sensible. Particurlarly in patients with hepatic or pulmonary metastases the indication for hepatic or pulmonary metastasectomy should be individualized, as hepatic or pulmonary metastases usually develop during a phase of disease, when extrahepatic or -pulmonary metastases also can be detected. Only in patients with long disease-free interval, with isolated hepatic or pulmonary metastases, and the possibility of R0-resection is hepatic or pulmonary metastasectomy a therapeutic option in selected cases.