Cerebrospinal fluid amounts of HLA-G in dimeric form are strongly associated to patients with MRI inactive multiple sclerosis

Background:

The relevance of human leukocyte antigen (HLA)-G in dimeric form in multiple sclerosis (MS) is still unknown.

Objective:

To investigate the contribution of cerebrospinal fluid (CSF) HLA-G dimers in MS pathogenesis.

Methods:

CSF amounts of 78-kDa HLA-G dimers were measured by western blot analysis in 80 MS relapsing–remitting MS (RRMS) patients and in 81 inflammatory and 70 non-inflammatory controls.

Results:

CSF amounts of 78kDa HLA-G dimers were more frequent in RRMS than in inflammatory ( p<0.01) and non-inflammatory controls ( p<0.001) and in magnetic resonance imaging (MRI) inactive than in MRI active RRMS ( p<0.00001).

Conclusion:

Our findings suggest that HLA-G dimers may be implicated in termination of inflammatory response occurring in MS.

A network of PUF proteins and Ras signaling promote mRNA repression and oogenesis in C. elegans

Cell differentiation requires integration of gene expression controls with dynamic changes in cell morphology, function, and control. Post-transcriptional mRNA regulation and signaling systems are important to this process but their mechanisms and connections are unclear. During C. elegans oogenesis, we find that two groups of PUF RNA binding proteins (RNABPs), PUF-3/11 and PUF-5/6/7, control different specific aspects of oocyte formation. PUF-3/11 limits oocyte growth, while PUF-5/6/7 promotes oocyte organization and formation. These two PUF groups repress mRNA translation through overlapping but distinct sets of 3' untranslated regions (3'UTRs). Several PUF-dependent mRNAs encode other mRNA regulators suggesting both PUF groups control developmental patterning of mRNA regulation circuits. Furthermore, we find that the Ras-MapKinase/ERK pathway functions with PUF-5/6/7 to repress specific mRNAs and control oocyte organization and growth. These results suggest that diversification of PUF proteins and their integration with Ras-MAPK signaling modulates oocyte differentiation. Together with other studies, these findings suggest positive and negative interactions between the Ras-MAPK system and PUF RNA-binding proteins likely occur at multiple levels. Changes in these interactions over time can influence spatiotemporal patterning of tissue development.

E2F1 induces pituitary tumor transforming gene (PTTG1) expression in human pituitary tumors

Rb/E2F is dysregulated in murine and human pituitary tumors. Pituitary tumor transforming gene (PTTG1), a securin protein, is required for pituitary tumorigenesis, and PTTG1 deletion attenuates pituitary tumor development in Rb(+/-) mice. E2F1 and PTTG1 were concordantly overexpressed in 29 of 46 Rb(+/-) murine pituitary tissues and also in 45 of 80 human pituitary tumors (P < 0.05). E2F1 specifically bound the hPTTG1 promoter as assessed by chromatin immunoprecipitation and biotin-streptavidin pull-down assay, indicating that hPTTG1 may act as a direct E2F1 target. Transfection of E2F1 and its partner DP1 dose-dependently activated hPTTG1 transcription up to 3-fold in p53-devoid H1299 cells but not in p53-replete HCT116 cells. E2F1 overexpression enhanced endogenous hPTTG1 mRNA and protein levels up to 3-fold in H1299 cells. The presence of endogenous p53/p21 constrained the induction, whereas knocking down either p53 or p21 in HCT116 cells restored E2F1-induced hPTTG1 transactivation and expression. Moreover, suppressing Rb by small interfering RNA concordantly elevated E2F1 and hPTTG1 protein levels. In contrast, transfection of E2F1 small interfering RNA lowered hPTTG1 levels 24 h later in HCT116 than in H1299 cells, indicating that p53 delays E2F1 action on hPTTG1. These results elucidate a mechanism for abundant tumor hPTTG1 expression, whereby Rb inactivation releases E2F1 to induce hPTTG1. This signaling pathway may underlie the requirement of PTTG1 for pituitary tumorigenesis.

Rat prolactinoma cell growth regulation by epidermal growth factor receptor ligands

Epidermal growth factor (EGF) regulates pituitary development, hormone synthesis, and cell proliferation. Although ErbB receptor family members are expressed in pituitary tumors, the effects of EGF signaling on pituitary tumors are not known. Immunoprecipitation and Western blot confirmed EGF receptor (EGFR) and p185(c-neu) protein expression in GH3 lacto-somatotroph but not in adrenocorticotropic hormone-secreting AtT20 pituitary tumor cells. EGF (5 nmol/L) selectively enhanced baseline ( approximately 4-fold) and serum-induced (>6-fold) prolactin (PRL) mRNA levels, whereas gefitinib, an EGFR antagonist, suppressed serum-induced cell proliferation and Pttg1 expression, blocked PRL gene expression, and reversed EGF-mediated somatotroph-lactotroph phenotype switching. Downstream EGFR signaling by ERK, but not phosphoinositide-3-kinase or protein kinase C, mediated the gefitinib response. Tumors in athymic mice implanted s.c. with GH3 cells resulted in weight gain accompanied by increased serum PRL, growth hormone, and insulin growth factor 1. Gefitinib decreased tumor volumes and peripheral hormone levels by approximately 30% and restored normal mouse body weight patterns. Mice treated with gefitinib exhibited decreased tumor tissue ERK1/2 phosphorylation and down-regulated tumor PRL and Pttg1 mRNA abundance. These results show that EGFR inhibition controls tumor growth and PRL secretion in experimental lacto-somatotroph tumors. EGFR inhibitors could therefore be useful for the control of PRL secretion and tumor load in prolactinomas resistant to dopaminergic treatment, or for those prolactinomas undergoing rare malignant transformation.

The impact of primary Gleason pattern on survival following brachytherapy for Gleason score 7 prostate cancer

15588

Background: A recent radical prostatectomy series reported lower rates of biochemical control and cause-specific survival in Gleason score 7 patients with primary Gleason pattern 4. In this study, we evaluated the impact of Gleason 4+3 versus 3+4 on cause-specific, biochemical progression-free and overall survival in patients managed with permanent prostate brachytherapy. Methods: From April 1995 to June 2003, 530 prostate cancer patients underwent brachytherapy for clinical stage T1b-T3c (2002 AJCC) prostate cancer with Gleason score 3+4 (n=300) or Gleason score 4+3 (n=230) histology. All patients underwent brachytherapy more than three years prior to analysis. The mean and median follow-up was 6.0 and 5.7 years, respectively (range 3.2–11.2 years). Of the evaluated cohort, 412 (77.7%) received supplemental XRT and 177 (33.4%) received androgen deprivation therapy. No statistical differences were discerned between the use of XRT, however, Gleason 4+3 patients were more likely (37.4% versus 30.3%, p=0.002) to receive ADT. Multiple clinical, treatment and dosimetric parameters were evaluated as predictors of cause-specific, biochemical progression-free and overall survival. Results: At 10 years, primary Gleason 3+4 versus 4+3 did not predict for cause-specific survival (96.7% versus 93.3%, p=0.506), biochemical progression-free (97.0 versus 92.9%, p=0.085) or overall survival (77.0% versus 78.0%, p=0.9333). Cox linear regression analysis demonstrated no significant predictors for cause-specific survival while pre-treatment PSA, prostate volume and clinical stage predicted for biochemical progression-free survival. Patient age, tobacco use and diabetes were the strongest predictor for overall survival. To date, 57 patients have died (25 with Gleason 4+3 and 32 with Gleason 3+4). Of the deaths, 76% were due to cardiovascular events or second malignancies. To date, 4 patients (2 in each cohort) have died of metastatic prostate cancer. Conclusions: Following brachytherapy, the primary Gleason pattern did not impact cause-specific, biochemical progression-free or overall survival in Gleason score 7 prostate cancer. Cardiovascular disease and second malignancies were responsible for 9 times more deaths than prostate cancer.

No significant financial relationships to disclose.

Prostate cancer distribution in patients diagnosed by transperineal template-guided saturation biopsy: Implications for brachytherapy treatment planning

15533

Background: Prostate cancer remains undetected in approximately one-third of patients following standard transrectal ultrasound-guided biopsy. In this study, we evaluated prostate cancer incidence, anatomic distribution, Gleason score profile and tumor burden in patients diagnosed by transperineal template-guided saturation biopsy (TTSB). Methods: One hundred and seventeen patients underwent TTSB. TTSB was performed under general anesthesia. All but one patient had undergone at least one prior negative TRUS biopsy. Criteria for inclusion included an elevated PSA and/or the diagnosis of ASAP or high-grade PIN on prior biopsy. The prostate gland was divided into 24 regional biopsy locations with 1–3 biopsies per region. The median number of biopsy cores was 50. Multiple clinical parameters were evaluated as predictors for prostate cancer diagnosis. Results: The mean patient age was 64.8 years with a mean PSA of 9.1 ng/mL and a prostate volume of 78.6 cm3. On average, patients had undergone 2.1 prior negative TRUS biopsies with a mean of 22.4 core biopsies. Prostate cancer was diagnosed in 49 patients (41.9%) with a Gleason score distribution of 6–9. Patients with a prostate volume of = 60 cm3 had a higher rate of cancer diagnosis compared to patients with larger glands (66% vs. 30%). Although no anatomic region of the prostate gland was spared of cancer, there was a preponderance of anterior-based malignancies. In patients with prostate cancer, an average of 9.9 cores were involved. In multivariate analysis, pre-saturation biopsy diagnosis and prostate volume were the best predictors for prostate cancer diagnosis. Conclusions: Transperineal template-guided saturation biopsy diagnosed prostate cancer in 41.9% of previously biopsied patients. Considerable anatomic variability in prostate cancer distribution was documented. Based on this and other reports, cancer eradication will be dependent on treatment of the entire prostate gland.

No significant financial relationships to disclose.

Prediction of PSA spikes by isotope and patient age following permanent prostate brachytherapy

15535

Background: To evaluate prostate specific antigen (PSA) spikes (bounces) following permanent prostate brachytherapy in low-risk patients randomized to Pd-103 or I-125. Methods: The study population consisted of 164 prostate cancer patients who were part of a prospective randomized trial comparing Pd-103 with I-125 for low-risk disease. Sixty-one patients (37.2%) received short course cytoreductive androgen deprivation therapy (ADT). No patient received supplemental XRT. The median follow-up was 5.4 years. All patients were implanted at least 3 years prior to analysis. On average, 10.1 post-treatment PSA’s were obtained per patient. Biochemical disease-free survival was defined as a PSA = 0.40 ng/mL after nadir. A PSA spike was defined as a rise of = 0.2 ng/mL followed by a durable decline to pre- spike levels. Multiple clinical, treatment and dosimetric parameters were evaluated as predictors for a PSA spike. Results: Forty- four patients (26.9%) developed a PSA spike including 45.7% (21/46) of the hormone naïve I-125 patients and 14.0% (8/57) of the hormone naïve Pd-103 patients. In hormone naïve patients, the mean time between implant and spike was 22.6 months and 18.7 months for I-125 and Pd-103 patients, respectively. In patients receiving neoadjuvant ADT, the incidence of spikes was comparable between isotopes (28.1% for I- 125 and 20.7% for Pd-103). The incidence of spikes was substantially different in patients < 65 vs = 65 years of age (16.3% vs. 38.5%). In multivariate Cox regression analysis, patient age at implant (p < 0.001) and isotope (p = 0.002) were significant predictors for spike. Conclusions: In low-risk prostate cancer patients, PSA spikes are most common in patients implanted with I-125 and/or younger than 65 years of age. Differences in isotope-related spikes are most pronounced in hormone naïve patients.

No significant financial relationships to disclose.

Pituitary tumor transforming gene overexpression facilitates pituitary tumor development

Intrinsic and extrinsic stimuli result in profound pituitary growth changes ranging from hypoplasia to hyperplasia. Pituitary tumor transforming gene (PTTG) abundance correlates with pituitary trophic status. Mice with Pttg inactivation exhibit pituitary hypoplasia, whereas targeted pituitary PTTG overexpression driven by alpha-subunit glycoprotein (alphaGSU) promoter results in focal pituitary hyperplasia. To test the impact of pituitary hyperplasia on tumor development, we crossbred alphaGSU.PTTG with Rb+/- mice, which develop pituitary tumors with high penetrance. Pituitary glands of resulting bitransgenic alphaGSU.PTTGxRb+/- mice were compared with monotransgenic alphaGSU.PTTG, Rb+/-, and wild-type mice. Confocal microscopy showed that PTTG-overexpressing cells have enlarged nuclei and marked redistribution of chromatin, and electron microscopy of alphaGSU.PTTG pituitaries showed enlarged gonadotrophs with prominent Golgi complexes and numerous secretory granules. These morphological findings were even more remarkable in alphaGSU.PTTGxRb+/- pituitaries. Mice from all four genotypes were sequentially imaged by magnetic resonance imaging to evaluate pituitary volume, and glands from alphaGSU.PTTGxRb+/- mice were the largest as early as 2 months of age (P = 0.0003). Cumulative incidence of pituitary tumors visualized by magnetic resonance imaging did not differ between Rb+/- and alphaGSU.PTTGxRb+/- mice. However, anterior lobe tumors determined after necropsy were 3.5 times more frequent in alphaGSU.PTTGxRb+/- than in Rb+/- mice (P = 0.0036), whereas the frequency of intermediate lobe tumors was similar. In summary, alphaGSU.PTTGxRb+/- pituitary glands exhibit enhanced cellular activity, increased volume, and higher prevalence of anterior pituitary tumors, indicating that changes in pituitary PTTG content directly relate to both pituitary trophic status and tumorigenic potential.

The role of Food and Drug Administration regulation of in vitro diagnostic devices--applications to genetics testing

The Food and Drug Administration (FDA) has been involved in the regulation of in vitro diagnostic devices (IVDs or laboratory tests) since the introduction of the Medical Device Amendments of 1976. IVDs developed as kits or systems intended for use in multiple laboratories require review by the FDA before being marketed to ensure appropriate performance and labeling. IVDs developed as in-house, or so-called "home-brew", tests or laboratory test services are considered medical devices, but historically have not been subject to premarket review as a matter of enforcement discretion. FDA recently established a new regulatory paradigm for in-house tests based on classification of the active ingredients or building blocks of these tests as analyte-specific reagents (ASRs). ASRs are exempt from premarket review but subject to both manufacturing and labeling controls. Currently, genetic tests are received and reviewed by the FDA in the same manner as other in vitro diagnostic tests. The FDA currently is in the process of chartering a new genetics advisory panel to provide the agency with outside expertise to deal with genetic testing issues. We are also continuing to work with other agencies within the Department of Health and Human Services to determine how we can cooperatively help foster this important new area of testing.

Food and Drug Administration (FDA)'s impact on laboratory performance: FDA's perspective

The Division of Clinical Laboratory Devices is responsible for the premarket review of in vitro diagnostic devices (laboratory tests). We currently process >1000 diverse applications per year. New versions of old devices are handled as premarket notifications, so-called 510(k) submissions. The review objective is to establish that the new product is "substantially equivalent" to its predicate. Fundamentally new devices are handled as premarket applications. The review objective is to establish de novo that the product is ¿safe and effective.¿ A central regulatory issue over the past several years has been the development of a standardized model for scientific review. The Food and Drug Administration contributes to the quality of in vitro diagnostic devices by providing oversight and objective review, by setting thresholds for product safety and effectiveness, and by ensuring that organized data and appropriate labeling is present in support of a device's intended use.

Food and Drug Administration (FDA)'s impact on laboratory performance: FDA's perspective

The Division of Clinical Laboratory Devices is responsible for the premarket review of in vitro diagnostic devices (laboratory tests). We currently process &gt;1000 diverse applications per year. New versions of old devices are handled as premarket notifications, so-called 510(k) submissions. The review objective is to establish that the new product is "substantially equivalent" to its predicate. Fundamentally new devices are handled as premarket applications. The review objective is to establish de novo that the product is ¿safe and effective.¿ A central regulatory issue over the past several years has been the development of a standardized model for scientific review. The Food and Drug Administration contributes to the quality of in vitro diagnostic devices by providing oversight and objective review, by setting thresholds for product safety and effectiveness, and by ensuring that organized data and appropriate labeling is present in support of a device's intended use.

The effect of in vivo glucose administration on human erythrocyte Ca2+-ATPase activity and on enzyme responsiveness in vitro to thyroid hormone and calmodulin

To characterize endogenous control mechanisms for human erythrocyte membrane Ca2+-ATPase ("calcium pump") activity, we studied the effect of changes in blood glucose concentration in vivo within the physiologic range on Ca2+-ATPase activity in red cells. Red cells obtained in the course of induced hyperglycemia were also studied to determine susceptibility of membrane Ca2+-ATPase to stimulation in vitro by thyroid hormone and calmodulin, both of which have been shown previously to enhance Ca2+-ATPase activity. Oral glucose administration (75 g) to eight healthy, adult subjects induced predictable increases in concentrations of blood glucose and immunoreactive insulin. Basal levels of activity of Ca2+-ATPase in red cells obtained after glucose ingestion fell 55% (P less than 0.025) by 30 min after glucose with recovery of enzyme activity to levels not significantly different from basal by 60 min. Activity of red cell Ca2+-ATPase at time zero was significantly stimulated in vitro by thyroxine (T4, 10(-10) M), triiodo-L-thyronine (T3, 10(-10) M), and calmodulin (100 ng/mg membrane protein). In vivo glucose administration led to depression of red cell enzyme responsiveness in vitro to T4 and T3; recovery from this effect did not occur by 120 min after oral administration of glucose. Calmodulin responsiveness of the enzyme in vitro was less significantly reduced in red cells obtained after glucose ingestion. Intravenous (i.v.) glucose administration (20 g) to five subjects also led to decreased basal enzyme activity (61% of fasting level at 20 min). A significant decrease in response of enzyme to T4 was achieved by 8 min after glucose administration (P less than 0.02), with recovery by 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of end-stage renal disease on responsiveness to calmodulin and thyroid hormone of calcium-ATPase in human red blood cells

Red blood cell membrane Ca2+-ATPase, a calcium-pump-associated enzyme, has been studied in a series of 10 patients with ESRD and in a group of normal volunteers. Basal enzyme activity was significantly reduced in cells from ESRD patients (0.189 +/- 0.018 vs. controls, 0.274 +/- 0.021 mumoles of Pi per milligram of membrane protein per 90 min; P less than 0.001). Calcium efflux from intact red cells, a functional correlate of Ca2+-ATPase activity, was also decreased in ESRD patients. Normal erythrocytes have recently been shown to have membrane Ca2+-ATPase activity that can be stimulated in vitro by physiologic concentrations of thyroid hormone (10(-10) M). In the present studies, ESRD red cell membrane Ca2+-ATPase activity was found to be unresponsive to thyroid hormone. In addition, calcium efflux from intact ESRD cells, in contrast to normal red cells, could not be stimulated by thyroid hormone. ESRD membrane Ca2+-ATPase was also poorly-responsive in vitro to purified calmodulin, the activator protein of the enzyme. This reduction in activity of Ca2+-ATPase in ESRD red cells is similar to previously described alterations in sodium-potassium-ATPase, another membrane-linked cation pump.