Regulation of PDE5 expression in normal prostate, benign prostatic hyperplasia, and adenocarcinoma.

BACKGROUND: Type 5 phosphodiesterase (PDE5) expression in the normal and pathological prostate is controversial. OBJECTIVES: This study aimed at identifying the cell type/s, if any, expressing PDE5 in human healthy or pathological prostate sections in order to further validate the rationale of PDE5 inhibitor (PDE5i) treatment of benign prostatic hyperplasia (BPH) and their safety in the treatment of erectile dysfunction following prostate cancer (PCa) surgery. MATERIALS AND METHODS: By immunohistochemical analysis, we studied PDE5 expression in tissue microarrays containing sections obtained from healthy, BPH, and PCa samples. RESULTS: Our results showed that PDE5 is barely expressed in the epithelial or stromal compartment of normal human prostates, but it is highly expressed in the stromal compartment of BPH sections. We also found that a low but significant number of PCa samples (22%) expressed PDE5 in the epithelial cancer cells but not in stromal cells and that such expression was not correlated with the tumor aggressiveness, according to their Gleason score. DISCUSSION AND CONCLUSION: PDE5 overexpression in the stromal compartment of BPH samples supports the rationale of PDE5 as a target in lower urinary tract symptoms of BPH. PDE5 expression in a significant percentage of PCa samples but the lack of correlation with the Gleason score suggests that this enzyme is not correlated with tumor aggressiveness; however, a role of PDE5 in the minimal residual disease of PCa cannot be excluded.

Sox2 is not required for melanomagenesis, melanoma growth and melanoma metastasis in vivo.

Melanoma is a dangerous form of skin cancer derived from the malignant transformation of melanocytes. The transcription factor SOX2 is not expressed in melanocytes, however, it has been shown to be differentially expressed between benign nevi and malignant melanomas and to be essential for melanoma stem cell maintenance and expansion in vitro and in xenograft models. By using a mouse model in which BRafV600E mutation cooperates with Pten loss to induce the development of metastatic melanoma, we investigated if Sox2 is required during the process of melanomagenesis, melanoma growth and metastasis and in the acquisition of resistance to BRAF inhibitors (BRAFi) treatments. We found that deletion of Sox2 specifically in Pten null and BRafV600E-expressing melanocytes did not prevent tumor formation and did not modify the temporal kinetics of melanoma occurrence compared to Sox2 wt mice. In addition, tumor growth was similar between Sox2 wt and Sox2 deleted (del) melanomas. By querying publicly available databases, we did not find statistically significant differences in SOX2 expression levels between benign nevi and melanomas, and analysis on two melanoma patient cohorts confirmed that Sox2 levels did not significantly change between primary and metastatic melanomas. Melanoma cell lines derived from both Sox2 genotypes showed a similar sensitivity to vemurafenib treatment and the same ability to develop vemurafenib resistance in long-term cultures. Development of vemurafenib resistance was not dependent on SOX2 expression also in human melanoma cell lines in vitro. Our findings exclude an oncogenic function for Sox2 during melanoma development and do not support a role for this transcription factor in the acquisition of resistance to BRAFi treatments.

Activated c-Kit receptor in the heart promotes cardiac repair and regeneration after injury.

The role of endogenous c-Kit receptor activation on cardiac cell homeostasis and repair remains largely unexplored. Transgenic mice carrying an activating point mutation (TgD814Y) in the kinase domain of the c-Kit gene were generated. c-Kit(TgD814Y) receptor was expressed in the heart during embryonic development and postnatal life, in a similar timing and expression pattern to that of the endogenous gene, but not in the hematopoietic compartment allowing the study of a cardiac-specific phenotype. c-Kit(TgD814Y) mutation produced a constitutive active c-Kit receptor in cardiac tissue and cells from transgenic mice as demonstrated by the increased phosphorylation of ERK1/2 and AKT, which are the main downstream molecular effectors of c-Kit receptor signaling. In adult transgenic hearts, cardiac morphology, size and total c-Kit(+) cardiac cell number was not different compared with wt mice. However, when c-Kit(TgD814Y) mice were subjected to transmural necrotic heart damage by cryoinjury (CI), all transgenic survived, compared with half of wt mice. In the sub-acute phase after CI, transgenic and wt mice showed similar heart damage. However, 9 days after CI, transgenic mice exhibited an increased number of c-Kit(+)CD31(+) endothelial progenitor cells surrounding the necrotic area. At later follow-up, a consistent reduction of fibrotic area, increased capillary density and increased cardiomyocyte replenishment rate (as established by BrdU incorporation) were observed in transgenic compared with wt mice. Consistently, CD45(-)c-Kit(+) cardiac stem cells isolated from transgenic c-Kit(TgD814Y) mice showed an enhanced endothelial and cardiomyocyte differentiation potential compared with cells isolated from the wt. Constitutive activation of c-Kit receptor in mice is associated with an increased cardiac myogenic and vasculogenic reparative potential after injury, with a significant improvement of survival.

Fgf9 inhibition of meiotic differentiation in spermatogonia is mediated by Erk-dependent activation of Nodal-Smad2/3 signaling and is antagonized by Kit Ligand.

Both fibroblast growth factor 9 (Fgf9) and Kit Ligand (Kl) signal through tyrosine kinase receptors, yet they exert opposite effects on meiotic differentiation in postnatal spermatogonia, Fgf9 acting as a meiosis-inhibiting substance and Kl acting as a promoter of the differentiation process. To understand the molecular mechanisms that might underlie this difference, we tried to dissect the intracellular signaling elicited by these two growth factors. We found that both Fgf9 and Kl stimulate Erk1/2 activation in Kit+ (differentiating) spermatogonia, even though with different time courses, whereas Kl, but not Fgf9, elicits activation of the Pi3k-Akt pathway. Sustained Erk1/2 activity promoted by Fgf9 is required for induction of the autocrine Cripto-Nodal-Smad2/3 signaling loop in these cells. Nodal signaling, in turn, is essential to mediate Fgf9 suppression of the meiotic program, including inhibition of Stra8 and Scp3 expression and induction of the meiotic gatekeeper Nanos2. On the contrary, sustained activation of the Pi3k-Akt pathway is required for the induction of Stra8 expression elicited by Kl and retinoic acid. Moreover, we found that Kl treatment impairs Nodal mRNA expression and Fgf9-mediated Nanos2 induction, reinforcing the antagonistic effect of these two growth factors on the meiotic fate of male germ cells.

SOHLH1 and SOHLH2 directly down-regulate STIMULATED BY RETINOIC ACID 8 (STRA8) expression.

As the name implies, Stimulated by Retinoic Acid 8 is an early retinoic acid (RA) responsive gene pivotal for the beginning of meiosis in female and male germ cells. Its expression is strictly time-dependent and cell-specific (pre-meiotic germ cells) and likely requires a complex mechanism of regulation. In this study, we demonstrate a direct negative control of SOHLH1 and SOHLH2, 2 germ cell specific bHLH transcription factors, on Stra8 expression. We observed a negative correlation between STRA8 and SOHLH1 expression in prepuberal differentiating mouse KIT(+) spermatogonia and found that SOHLH1 and SOHLH2 were able to directly and cooperatively repress STRA8 expression in cell lines in vitro through binding to its promoter. We also identified 2 canonical E-Box motives in the Stra8 promoter that mediated the negative regulation of SOHLH1 and SOHLH2 on these gene both in the cell lines and KIT(+) spermatogonia. We hypothesize that this novel negative activity of SOHLH1 and SOHLH2 in male cooperates with that of other transcription factors to coordinate spermatogonia differentiation and the RA-induced meiosis and in female ensures STRA8 down-regulation at mid-end stages of meiotic prophase I.

Role of the multidisciplinary team in breast cancer management: results from a large international survey involving 39 countries.

BACKGROUND: The optimal management of patients with breast cancer (BC) requires the expertise of specialists from different disciplines. This has led to the evolution of multidisciplinary teams (MDTs), allowing all key professionals to jointly discuss individual patients and to contribute independently to clinical decisions. Data regarding BC MDTs in different regions and countries are scarce. METHODS: The investigators of a large global phase III adjuvant BC trial being conducted by the Breast International Group were invited to respond to a questionnaire about the extent, structure, and function of BC MDTs. RESULTS: One hundred and fifty-two responses from 39 countries were received, and remarkable differences were noted in different geographic regions. Sixty-five percent of the respondents from eastern Europe, 63% from western Europe, 35% from Asia, and 25% from South America declared that MDT was a mandatory part of BC care in their country. Ninety percent of the respondents from Europe stated their MDTs met weekly, compared with only half of the respondents from Asia. CONCLUSION: This survey is perhaps the first large-scale effort to collect information regarding BC MDTs from different parts of the world and provides objective information of frequency, composition, function, and working mechanism of BC MDTs.

Is risk of central nervous system (CNS) relapse related to adjuvant taxane treatment in node-positive breast cancer? Results of the CNS substudy in the intergroup Phase III BIG 02-98 Trial.

BACKGROUND: Breast cancer central nervous system (CNS) metastases are an increasingly important problem because of high CNS relapse rates in patients treated with trastuzumab and/or taxanes. PATIENTS AND METHODS: We evaluated data from 2887 node-positive breast cancer patients randomised in the BIG 02-98 trial comparing anthracycline-based adjuvant chemotherapy (control arms) to anthracycline-docetaxel-based sequential or concurrent chemotherapy (experimental arms). After a median follow-up of 5 years, 403 patients had died and detailed information on CNS relapse was collected for these patients. RESULTS: CNS relapse occurred in 4.0% of control patients and 3.7% of docetaxel-treated patients. CNS relapse occurred in 27% of deceased patients in both treatment groups. CNS relapse was usually accompanied by neurologic symptoms (90%), and 25% of patients with CNS relapse died without evidence of extra-CNS relapse. Only 20% of patients survived 1 year from the diagnosis of CNS relapse. Prognosis of CNS relapse was worse for patients with meningeal carcinomatosis when compared with brain metastases. Unexpected findings included a higher rate of positive cerebrospinal fluid cytology (8% versus 3%) and more frequent use of magnetic resonance imaging for diagnosis (47% versus 30%) in the docetaxel-treated patients. CONCLUSION: There is no evidence that adjuvant docetaxel treatment is associated with an increased frequency of CNS relapse.

Molecular biology tools for dissecting sexual behavior.

The tools of molecular biology have just begun to demonstrate the role of genes in controlling sexual behavior and how hormones can influence sexual and reproductive motivation by controlling gene expression. In this review article the use of the new term "molecular sexology" is proposed to indicate the growing evidence that molecular biology techniques can be a useful tool not only to understand the genetic bases of the animal (and soon human) sexual behavior, but also in order to provide the rationale of the use of advanced therapeutic approaches, such as gene transfer, to the symptoms and diseases of sexuality.

Molecular mechanisms utilized by alternative c-kit gene products in the control of spermatogonial proliferation and sperm-mediated egg activation.

The c-kit proto-oncogene plays a dual role in the control of male fertility in mice through two alternative gene products: (1). c-kit [the transmembrane tyrosine kinase receptor for stem cell factor (SCF)], which is expressed and functional in differentiating spermatogonia of the postnatal testis, in which c-kit is essential for pre-meiotic proliferation; and (2). tr-kit, an intracellular protein which is specifically accumulated during spermiogenesis through the use of an alternative intronic promoter, and which is able to trigger mouse egg activation when microinjected into the cytoplasm of metaphase II arrested oocytes. Here, we summarize the most recent findings about the molecular pathways through which c-kit regulates cell cycle progression in mitotic germ cells, and those through which sperm-derived tr-kit triggers parthenogenetic completion of meiosis II and pronuclear formation in microinjected mouse eggs.

The feasibility of classical cyclophosphamide, methotrexate, 5-fluorouracil (CMF) for pre- and post-menopausal node-positive breast cancer patients in a Belgian multicentric trial: a study of consistency in relative dose intensity (RDI) and cumulative doses across institutions.

BACKGROUND: Classical cyclophosphamide, methotrexate, 5-fluorouracil (CMF) including oral cyclophosphamide is still considered an important adjuvant chemotherapy regimen in patients with early breast cancer (BC). Concern has been raised regarding the feasibility of this regimen, especially in postmenopausal patients. PATIENTS AND METHODS: 254 pre- and post-menopausal node-positive BC patients aged < or = 70 years received six cycles of CMF in the context of a Belgian multicentric phase III trial of adjuvant chemotherapy. CMF dose and schedule were as follows: cyclophosphamide 100 mg/m2 p.o. on days 1 to 14, methotrexate 40 mg/m2 intravenously (i.v.) on days 1 and 8, 5-fluorouracil 600 mg/ml i.v. on days 1 and 8; cycles q. 28 days. The relative dose intensity (RDI) was calculated as the ratio between the delivered DI and the planned DI. We also analysed the RDI in two subgroups of patients with age > or = 50 years or < 50 years. RESULTS: Overall, the percentage of patients ending the six cycles of the planned CMF regimen was 90%. The mean RDI achieved in the population of 254 patients was 90% (range 8% to 129%). The subgroup analysis of patients aged > or = 50 years and < 50 years showed that 81% and 76% of patients, respectively, received > or = 80% of the planned chemotherapy dose intensity (P = 0.33). No statistically significant difference was found between the percentage of patients who received a RDI < 80% and the participating institutions (P = 0.50). CONCLUSIONS: The classical CMF regimen was a feasible regimen in the context of a multicentric trial, in which academic institutions as well as community hospitals participated. No substantial differences in RDI and cumulative doses were found in relation to a patient's age and the participating institution.

HER-2 and topo-isomerase IIalpha as predictive markers in a population of node-positive breast cancer patients randomly treated with adjuvant CMF or epirubicin plus cyclophosphamide.

BACKGROUND: The predictive role of HER-2 in node-positive breast cancer patients receiving CMF or an anthracycline-based adjuvant therapy remains unclear. In addition, topo-isomerase II alpha (topo IIalpha), as the cellular target of anthracyclines, might have value as a predictive marker. PATIENTS AND METHODS: Four hundred eighty-one archival primary tumor samples were collected among 777 patients entered into a multicenter phase III trial comparing classical CMF with epirubicin cyclophosphamide (HEC) as adjuvant therapy of node-positive breast cancer. HER-2 was evaluated by immunohistochemistry (IHC) using different antibodies (Abs). Topo IIalpha was evaluated by IHC using the Ab KiS 1. In each subgroup of patients identified by HER-2 and topo IIalpha, adjusted hazard ratios for event-free survival (EFS) and the corresponding 95% confidence intervals have been calculated for the different study comparisons. An interaction test has been performed to investigate the role of HER-2 and topo IIalpha as predictive markers. RESULTS: When HER-2 was evaluated by CB-11 and 4D5 mAbs, the EFS adjusted hazard ratios (HR) for the main study comparison HEC vs. CMF were: HER-2 positive: 0.33 (95% confidence interval (95% CI): 0.09 1.27, P = 0.08), HER-2 negative: 1.16 (95%, CI: 0.71-1.90, P = 0.56); the P-value for the interaction test was 0.10. When HER-2 was evaluated by TAB-250 + pAbl Abs, the adjusted HR for the same comparison were: HER-2 positive: 1.06 (95% CI: 0.45-2.52, P = 0.90), HER-2 negative: 0.99 (95% CI: 0.58-1.68, P = 0.97); the P-value for the interaction test was 0.84. With regard to topo IIalpha, the adjusted HR for the EFS comparison HEC vs. CMF were: topo IIalpha positive: 0.66 (95% CI: 0.32-1.36, P = 0.25), topo IIalpha negative: 1.26 (95% CI: 0.63-2.50, P = 0.51); the P-value for the interaction test was 0.13. CONCLUSIONS: This study suggests that in node-positive breast cancer patients randomly treated with CMF or an epirubicin-based regimen, the predictive value of HER-2 may vary according to the Abs used in the immunohistochemistry assay. In addition, the study supports the concept that topo IIalpha might be involved in the determination of tumor responsiveness to an anthracycline-based adjuvant therapy.

Signaling through extracellular signal-regulated kinase is required for spermatogonial proliferative response to stem cell factor.

In vitro addition of stem cell factor (SCF) to c-kit-expressing A(1)-A(4) spermatogonia from prepuberal mice stimulates their progression into the mitotic cell cycle and significantly reduces apoptosis in these cells. SCF addition results in a transient activation of extracellular signal-regulated kinases (Erk)1/2 as well as of phosphatidylinositol 3-kinase (PI3K)-dependent Akt kinase. These events are followed by a rapid re-distribution of cyclin D3, which becomes predominantly nuclear, whereas its total cellular amount does not change. Nuclear accumulation of cyclin D3 is coupled to transient activation of the associated kinase activity, assayed using the retinoblastoma protein (Rb) as a substrate. These events were followed by a transient accumulation of cyclin E, stimulation of the associated histone H1-kinase activity, a delayed accumulation of cyclin A2, and Rb hyper-phosphorylation. All the events associated with SCF-induced cell cycle progression are inhibited by the addition of either a PI3K inhibitor or a mitogen-activated protein-kinase kinase (MEK) inhibitor, indicating that both MEK and PI3K are essential for c-kit-mediated proliferative response. On the contrary, the anti-apoptotic effect of SCF is not influenced by the separate addition of either MEK or PI3K inhibitors. Thus, SCF effects on mitogenesis and survival in c-kit expressing spermatogonia rely on different signal transduction pathways.

Evaluation of HER2, p53, bcl-2, topoisomerase II-alpha, heat shock proteins 27 and 70 in primary breast cancer and metastatic ipsilateral axillary lymph nodes.

BACKGROUND: Breast cancer is a heterogeneous disease. Predictive biological markers (BM) of responsiveness to therapy need to be identified. Evaluation of BM is mainly done at the primary site. However, in the adjuvant therapy of breast cancer, the main goal is control of micrometastases. It is still unknown whether heterogeneity in the expression of BM between the primary site and its micrometastases exists. OBJECTIVE: To evaluate the expression of some BM with potential predictive value from the primary breast cancer site and metastatic ipsilateral axillary lymph nodes. PATIENTS AND METHODS: Focality (percentage of positive cells) and intensity staining scores were evaluated for each marker. Freshly cut sections (4 microm) from embedded blocks of breast cancer fixed in formalin or bouin were put onto superfrost slides (Menzel-Gläser). Protein expression was evaluated immunohistochemically (IHC) using monoclonal antibodies against: topo II-alpha (clone KiS1, 1 microg/ml, Roche) with a trypsine pre-treatment (P); HSP27 (clone G3.1, 1/60, Biogenex), HSP70 (clone BRM.22, 1/80, Biogenex) and HER2 (clone CB11, 1/40, Novocastra; without P); p53 (clone D07, 1/750, Dako) and bcl-2 (clone 124, 1/60, Dako) with citrate buffer as P. RESULTS: Overall, the percentage of discordant marker status in the primary tumour and its metastatic lymph nodes was 2% for HER2, 6% for p53, 15% for bcl-2, 19% for topoisomerase II-alpha, 24% for HSP27 and 30% for HSP70. For the subgroup of patients with positive BM in the primary tumour, the percentage of discordance was 6% for HER2, 7% for p53, 14% for bcl-2, 19% for HSP70, 21% for topoisomerase II-alpha and 36% for HSP27. For the subgroup of patients with positive BM in the lymph nodes, the percentage of discordance was 9% for bcl-2, 15% for HER2 and p53, 21% for topoisomerase II-alpha, 22% for HSP27 and 25% for HSP70. CONCLUSIONS: 1) No biological marker had 100% concordant results. 2) Although some discordant cases might be explained by the limitations of the IHC technique, future studies aiming to evaluate the predictive value of BM in the adjuvant therapy of breast cancer should take into account a possible difference in BM expression between the primary and the metastatic sites.

Intermittent catheterization with a prelubricated catheter in spinal cord injured patients: a prospective randomized crossover study.

PURPOSE: We compared the safety and patient acceptance of a conventional Nélaton and a prelubricated nonhydrophilic catheter in 18 spinal cord injured patients on intermittent catheterization. MATERIALS AND METHODS: In a prospective crossover study each catheter was used for 7 weeks and the initial course was randomized. Urinalysis and urine culture were performed at 2, 4 and 7 weeks. Urethral trauma was evaluated by urethral cell count on the surface of each catheter used on the last day of each study period. Patient satisfaction was assessed at the end of the study by a questionnaire using multiple visual analog scales. RESULTS: Urinary tract infection was identified in 12 and 4 patients on a Nélaton and a prelubricated nonhydrophilic catheter (p = 0.03), while asymptomatic bacteruria was identified in 18 and 8 (p = 0.0244), respectively. The mean urethral cell count plus or minus standard deviation on the catheter surface was 6.7 +/- 2.8 x 10(4) and 15.1 +/- 8.9 x 10(4) for the prelubricated nonhydrophilic and the Néelaton catheter, respectively (p = 0.01). The prelubricated nonhydrophilic catheter resulted in a better mean satisfaction score than the Nélaton catheter (2.33 +/- 1.06 versus 4.72 +/- 2.13, p = 0.022). Urethral bleeding was reported in 2 patients during the study period while using the Nélaton catheter. CONCLUSIONS: The prelubricated nonhydrophilic catheter is a safe, effective and comfortable option in spinal cord injured patients on intermittent self-catheterization.

Phase III trial comparing two dose levels of epirubicin combined with cyclophosphamide with cyclophosphamide, methotrexate, and fluorouracil in node-positive breast cancer.

PURPOSE: To compare a full-dose epirubicin-cyclophosphamide (HEC) regimen with classical cyclophosphamide, methotrexate, and fluorouracil (CMF) therapy and with a moderate-dose epirubicin-cyclophosphamide regimen (EC) in the adjuvant therapy of node-positive breast cancer. PATIENTS AND METHODS: Node-positive breast cancer patients who were aged 70 years or younger were randomly allocated to one of the following treatments: CMF for six cycles (oral cyclophosphamide); EC for eight cycles (epirubicin 60 mg/m(2), cyclophosphamide 500 mg/m(2); day 1 every 3 weeks); and HEC for eight cycles (epirubicin 100 mg/m(2), cyclophosphamide 830 mg/m(2); day 1 every 3 weeks). RESULTS: Two hundred fifty-five, 267, and 255 eligible patients were treated with CMF, EC, and HEC, respectively. Patient characteristics were well balanced among the three arms. One and three cases of congestive heart failure were reported in the EC and HEC arms, respectively. Three cases of acute myeloid leukemia were reported in the HEC arm. After 4 years of median follow-up, no statistically significant differences were observed between HEC and CMF (event-free survival [EFS]: hazards ratio [HR] = 0.96, 95% confidence interval [CI], 0.70 to 1.31, P =.80; distant-EFS: HR = 0.97, 95% CI, 0.70 to 1.34, P =.87; overall survival [OS]: HR = 0.97, 95% CI, 0.65 to 1.44, P =.87). HEC is more effective than EC (EFS: HR = 0.73, 95% CI, 0.54 to 0.99, P =.04; distant-EFS: HR = 0.75, 95% CI, 0.55 to 1.02, P =.06; OS HR = 0.69, 95% CI, 0.47 to 1.00, P =.05). CONCLUSION: This three-arm study does not show an advantage in favor of an adequately dosed epirubicin-based regimen over classical CMF in the adjuvant therapy of node-positive pre- and postmenopausal women with breast cancer. Moreover, this study confirms that there is a dose-response curve for epirubicin in breast cancer adjuvant therapy.

Doxorubicin followed by docetaxel versus docetaxel followed by doxorubicin in the adjuvant treatment of node positive breast cancer: results of a feasibility study.

BACKGROUND: Doxorubicin (A) and Docetaxel (T) are amongst the most active agents in breast cancer treatment. The impact of drug sequencing is an issue still under evaluation. OBJECTIVE: To evaluate the feasibility and tolerability of two A and T-based sequential regimens, in which the sequence of drug administration was reversed. METHODS: The study included patients pts aged < or = 70 years, with operable node positive breast cancer. Two consecutive groups of patients received one of the following regimens: 1) Sequential A-->T-->CMF: Doxorubicin 75 mg/m2, i.v., day 1, q3wks x 3 cycles, followed by Docetaxel 100 mg/m2, i.v., day 1, q3wks x 3 cycles, followed by i.v. CMF days 1 and 8 q4wks x 3 cycles. 2) Sequential T-->A-->CMF: same doses for Doxorubicin and Docetaxel but reverse sequence of administration, followed by oral CMF (CPA 100 mg/m2, oral, days 1-14 + MTX 40 mg/m2, i.v., days 1 and 8 + 5FU 600 mg/m2, i.v., days 1 and 8, q4wks). An analysis of treatment administration and toxicity was performed for the first six cycles of CT, in the two treatment groups. RESULTS: Group 1 with 20 patients and group 2 with 14 patients were balanced in terms of patient and tumour characteristics. There was one early treatment discontinuation in each group due to toxicity (one allergic and one skin reaction to docetaxel). Median relative dose intensity was 100% for both drugs in both groups. The most relevant side effects were (overall incidence, group 1 vs group 2): Myalgia: 45% vs 72%; Arthralgia: 15% vs 57%; Skin: 35% vs 57%; Neurosensory: 55% vs 64%; Stomatitis 65% vs 36%; conjunctivitis 25% vs 57%; Neutropenic Fever 20% vs 21% and Fatigue 80% vs 93%. Grade 3/4 adverse events' rate was low in the two groups. CONCLUSIONS: 1) Both sequences were estimated feasible due to the optimal treatment administration and limited incidence of G3-G4 side effects. 2) The concomitant use of lenograstin might partially explain the reported incidence of myalgia and arthralgia. 3) No conclusion can be drawn on the most tolerable regimen due to the limited number of patients.

Role of c-kit in mammalian spermatogenesis.

The tyrosine-kinase receptor c-kit and its ligand, stem cell factor (SCF), are essential for the maintenance of primordial germ cells (PGCs) in both sexes. However, c-kit and a post-meiotic-specific alternative c-kit gene product play important roles also during post-natal stages of spermatogenesis. In the adult testis, the c-kit receptor is re-expressed in differentiating spermatogonia, but not in spermatogonial stem cells, whereas SCF is expressed by Sertoli cells under FSH stimulation. SCF stimulates DNA synthesis in type A spermatogonia cultured in vitro, and injection of anti-c-kit antibodies blocks their proliferation in vivo. A point mutation in the c-kit gene, which impairs SCF-mediated activation of phosphatidylinositol 3-kinase, does not cause any significant reduction in PGCs number during embryonic development, nor in spermatogonial stem cell populations. However males are completely sterile due to a block in the initial stages of spermatogenesis, associated to abolishment of DNA-synthesis in differentiating A1-A4 spermatogonia. With the onset of meiosis c-kit expression ceases, but a truncated c-kit product, tr-kit, is specifically expressed in post-meiotic stages of spermatogenesis, and is accumulated in mature spermatozoa. Microinjection of tr-kit into mouse eggs causes their parthenogenetic activation, suggesting that it might play a role in the final function of the gametes, fertilization.

The role of stem cell factor and of alternative c-kit gene products in the establishment, maintenance and function of germ cells.

The c-kit gene plays a fundamental role during the establishment, the maintenance and the function of germ cells. In the embryonal gonad the c-kit tyrosine kinase receptor and its ligand Stem Cell Factor (SCF) are required for the survival and proliferation of primordial germ cells. In the postnatal animal, c-kit/SCF are required for the production of the mature gametes in response to gonadotropic hormones, i.e. for the survival and/or proliferation of the only proliferating germ cells of the testis, the spermatogonia, and for the growth and maturation of the oocytes. Finally, a truncated c-kit product, tr-kit, specifically expressed in post-meiotic stages of spermatogenesis and present in mature spermatozoa, causes parthenogenetic activation when microinjected into mouse eggs, suggesting that it might play a role in the final function of the gametes, fertilization.

A feasibility study evaluating docetaxel-based sequential and combination regimens in the adjuvant therapy of node-positive breast cancer.

BACKGROUND AND PURPOSE: Docetaxel is an active agent in the treatment of metastatic breast cancer. We evaluated the feasibility of docetaxel-based sequential and combination regimens as adjuvant therapies for patients with node-positive breast cancer. PATIENTS AND METHODS: Three consecutive groups of patients with node-positive breast cancer or locally-advanced disease, aged < or = 70 years, received one of the following regimens: a) sequential A-->T-->CMF: doxorubicin 75 mg/m2 q 3 weeks x 3, followed by docetaxel 100 mg/m2 q 3 weeks x 3, followed by i.v. CMF days 1 + 8 q 4 weeks x 3; b) sequential accelerated A-->T-->CMF: A and T were administered at the same doses q 2 weeks; c) combination therapy: doxorubicin 50 mg/m2 + docetaxel 75 mg/m2 q 3 weeks x 4, followed by CMF x 4. When indicated, radiotherapy was administered during or after CMF, and tamoxifen started after the end of CMF. RESULTS: Seventy-nine patients have been treated. Median age was 48 years. A 30% rate of early treatment discontinuation was observed in patients receiving the sequential accelerated therapy (23% during A-->T), due principally to severe skin toxicity. Median relative dose-intensity was 100% in the three treatment arms. The incidence of G3-G4 major toxicities by treated patients, was as follows: skin toxicity a: 5%; b: 27%; c: 0%; stomatitis a: 20%; b: 20%; c: 3%. The incidence of neutropenic fever was a: 30%; b: 13%; c: 48%. After a median follow-up of 18 months, no late toxicity has been reported. CONCLUSIONS: The accelerated sequential A-->T-->CMF treatment is not feasible due to an excess of skin toxicity. The sequential non accelerated and the combination regimens are feasible and under evaluation in a phase III trial of adjuvant therapy.

Glial cell line-derived neutrotrophic factor and neurturin can act as paracrine growth factors stimulating DNA synthesis of Ret-expressing spermatogonia.

Glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) are related growth factors which exert trophic effects on several neuronal populations and developing kidney. GDNF-family ligands interact with membrane receptors designated GFRalphas which, in turn, mediate stimulation of the Ret receptor tyrosine kinase. Here we show that Ret, GFRalpha-1 (the GDNF receptor), and GFRalpha-2 (the NTN receptor) are expressed by testicular germ cells, while GDNF and NTN are expressed by Sertoli cells. Both GDNF and NTN stimulate DNA synthesis in spermatogonia. Furthermore, Ret, ligands and co-receptors are expressed in germ cell tumors. Thus, GDNF-family ligands may act as paracrine factors in spermatogenesis and this circuit may be active in germ cell tumors.