Ectopic expression of VAV1 reveals an unexpected role in pancreatic cancer tumorigenesis

Herein, we show that the hematopoietic-specific GEF VAV1 is ectopically expressed in primary pancreatic adenocarcinomas due to demethylation of the gene promoter. Interestingly, VAV1-positive tumors had a worse survival rate compared to VAV1-negative tumors. Surprisingly, even in the presence of oncogenic KRAS, VAV1 RNAi abrogates neoplastic cellular proliferation in vitro and in vivo, thus identifying Vav1 as a growth-stimulatory protein in this disease. Vav1 acts synergistically with the EGF receptor to stimulate pancreatic tumor cell proliferation. Mechanistically, the effects of Vav1 require its GEF activity and the activation of Rac1, PAK1, and NF-kappaB and involve cyclin D1 upregulation. Thus, the discovery of prooncogenic pathways regulated by Vav1 makes it an attractive target for therapeutic intervention.     

Comparison of intense pulsed light to 595-nm long-pulsed pulsed dye laser for treatment of hypertrophic surgical scars: a pilot study

BACKGROUND: The short-pulsed pulsed dye laser (PDL) has been previously reported to improve the appearance of hypertrophic scars. Prolonged purpura following treatment led to the development of the newer long-pulsed pulsed dye laser (LPDL). Intense pulsed light (IPL) has been extensively used to improve the various components of photo damage and to reduce the incidence of purpura, but its effect on scars has not been analyzed. The objective of this pilot study was to prospectively determine and compare the safety and efficacy of LPDL and IPL on surgically induced scars. METHODS: Breast reduction scars (N = 10 scars) and abdominoplasty scars (N=5 scars) were treated using both LPDL and IPL. For breast reduction scars, one side was treated with each technique. For abdominoplasty scars, one half of the scar was treated with each device. Two treatments were performed 2 months apart. Physician global assessment scores of improvement were determined by side-by-side comparison of preoperative and randomly presented postoperative photographs. Patient pain scores during treatment were also obtained and the presence of post, treatment purpura was assessed. RESULTS: Mean improvement on a 0 to 3 point scale was 2.2 (55%) after the first LPDL treatment and 3.2 (80%) after the second. Mean improvement was 1.8 (45%) after the first IPL treatment and 2.6 (65%) after the second. Differences in improvement between the LPDL and IPL sides were not statistically significant. Patients rated IPL as more painful than LPDL. The incidence of post-treatment purpura was lower with IPL. CONCLUSIONS: This pilot study suggests that LPDL and IPL are equally effective in improving the appearance of hypertrophic surgical scars. IPL offers a novel method of treating scars that minimizes the risk of purpura.     

A large 12-month extension study of an 8-week trial to evaluate the safety and efficacy of triple combination (TC) cream in melasma patients previously treated with TC cream or one of its dyads

This was a 12-month extension of a randomized, investigator-blinded, multicenter, 8-week trial with triple combination (TC) cream in facial melasma. A total of 585 patients were enrolled in the study and 569 patients received study medication. Three hundred eighty-nine patients completed 6 months of treatment and 327 patients completed 12 months of treatment. TC cream demonstrated a favorable safety profile: only 14 patients (2.5%) discontinued the study due to treatment-related adverse events (AEs). The 2 cases of skin atrophy were mild and did not lead to withdrawal. From the 23 cases of mild telangiectasia, only 2 resulted in discontinuation. All others were transient. Results confirmed those of a previous smaller study, with both physicians and patients reporting clinically significant improvements in melasma. By month 12, 80% of patients had lesions completely cleared or nearly cleared. Once daily application of TC cream applied intermittently over a long period is a safe, tolerable, and effective treatment for moderate to severe melasma of the face.     

Effects of dopamine β-hydroxylase genotype and disulfiram inhibition on catecholamine homeostasis in mice

Rationale Dopamine β-hydroxylase (DBH) converts dopamine (DA) to norepinephrine (NE), thus playing a critical role in catecholamine metabolism.Objectives/Methods We examined the effects of Dbh gene dosage and the DBH inhibitor disulfiram in mice with zero, one, or two null Dbh alleles (+/+, +/−, and −/− mice).Results DBH protein levels in adrenal and prefrontal cortex (PFC) and adrenal DBH activity were proportional to number of wild-type alleles. Adrenal DA was slightly increased in +/− mice and markedly increased (80-fold) in −/− mice compared to wild-type animals. While adrenal NE and epinephrine (EPI) were undetectable in −/− mice, adrenal concentrations of NE and EPI were similar in +/+ and +/− mice, suggesting that the increase in DA maintains the normal rate of β-hydroxylation in Dbh +/− mice. Disulfiram had little effect on adrenal catecholamine levels, regardless of genotype or dose. NE was absent in the PFC of −/− mice, but only slightly reduced in +/− animals compared to wild-type animals. PFC DA was increased twofold in +/− mice and fivefold in −/− mice, and the NE to DA ratio was reduced (∼35%) in +/− mice, compared to wild-type mice. Disulfiram significantly decreased PFC NE and increased DA in +/+ and +/− animals, with the disulfiram and genotype effects on the PFC NE to DA ratio apparently additive.Conclusions The data reveal potentially important and apparently additive effects of Dbh genotype and disulfiram administration on PFC catecholamine metabolism. These effects may have implications for genetic control of DBH activity in humans and for understanding therapeutic effects of disulfiram.B.N. Bourdélat-Parks and G.M. Anderson contributed equally to this work     

Individual and combined effects of peroxisome proliferator-activated receptor and {gamma} agonists, fenofibrate and rosiglitazone, on biomarkers of lipid and glucose metabolism in healthy nondiabetic volunteers

This open-label, randomized, placebo-controlled, incomplete-block, 3-period crossover pilot study investigated the effects of peroxisome proliferator-activated receptor alpha- and gamma-agonists on biomarkers of lipid and glucose metabolism in 12 nondiabetic subjects. Plasma samples were collected before and after each 14-day treatment with placebo, fenofibrate (201 mg/d), rosiglitazone (4 mg twice daily), and combined fenofibrate (201 mg/d) plus rosiglitazone (4 mg twice daily). Except for triglycerides (P < .042) and free fatty acids (P < .074), no significant interaction was demonstrated between fenofibrate and rosiglitazone; thus, the effect due to each drug alone was evaluated (presence/absence of drug). Fenofibrate significantly (P < .050) increased lipoprotein lipase activity (35%) and decreased apolipoproteins B (13%) and C-III (20%). Rosiglitazone significantly (P < .050) decreased fasting glucose (7.3%) and increased apolipoprotein C-III (19%) and adiponectin (137%). Fenofibrate and rosiglitazone also produced effects on triglycerides and free fatty acids, but it was not possible to determine if these effects were synergistic in nature.     

Effect of insulin treatment on tissue size of the genitourinary tract in BB rats with spontaneously developed and streptozotocin-induced diabetes

To examine the differences between spontaneous and streptozotocin (STZ)-induced diabetes, four parallel studies were performed; three studies of diabetes-prone BB (BBDP/Wor) rats maintained for 8, 16, and 32 weeks and one study of STZ-injected diabetes-resistant BB (BBDR/Wor) rats maintained for 32 weeks. Each diabetic study has three groups of rats: a control group; a euglycemic group, which received sufficient amounts of insulin; and a hyperglycemic group, which received a suboptimal dose of insulin. The extent of tissue weight changes was generally shown to be less dramatic in the euglycemic diabetic than in the hyperglycemic diabetic rats. STZ-induced diabetes increased the bladder weight more dramatically (up to 3-fold) than did spontaneous diabetes (up to 2-fold). Furthermore, a significant decrease in the size of the adrenal gland (20%) and testis (10%) is observed only with spontaneous diabetes, whereas a significant decrease in the size of the ventral prostate (30%) is observed only with STZ-induced diabetes, although the serum testosterone levels are similar in both groups. Our data demonstrate that there are differences in the effect of insulin treatment on the tissue size of the genitourinary tract between spontaneously developed and streptozotocin-induced diabetes in BB rats.     

Reproductive factors and subtypes of breast cancer defined by hormone receptor and histology

Reproductive factors are associated with reduced risk of breast cancer, but less is known about whether there is differential protection against subtypes of breast cancer. Assuming reproductive factors act through hormonal mechanisms they should protect predominantly against cancers expressing oestrogen (ER) and progesterone (PR) receptors. We examined the effect of reproductive factors on subgroups of tumours defined by hormone receptor status as well as histology using data from the NIHCD Women's Contraceptive and Reproductive Experiences (CARE) Study, a multicenter case-control study of breast cancer. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) as measures of relative risk using multivariate unconditional logistic regression methods. Multiparity and early age at first birth were associated with reduced relative risk of ER + PR + tumours (P for trend=0.0001 and 0.01, respectively), but not of ER - PR - tumours (P for trend=0.27 and 0.85), whereas duration of breastfeeding was associated with lower relative risk of both receptor-positive (P for trend=0.0002) and receptor-negative tumours (P=0.0004). Our results were consistent across subgroups of women based on age and ethnicity. We found few significant differences by histologic subtype, although the strongest protective effect of multiparity was seen for mixed ductolobular tumours. Our results indicate that parity and age at first birth are associated with reduced risk of receptor-positive tumours only, while lactation is associated with reduced risk of both receptor-positive and -negative tumours. This suggests that parity and lactation act through different mechanisms. This study also suggests that reproductive factors have similar protective effects on breast tumours of lobular and ductal origin.     

Incidence, cost, and mortality of neutropenia hospitalization associated with chemotherapy

BACKGROUND: Neutropenia is a common side effect of chemotherapy, often requiring hospitalization for treatment of severe cases. Neutropenia hospitalization (NH) rates have been reported in individual studies, but national estimates are needed. METHODS: Chemotherapy-induced NHs were identified in the 1999 hospital discharge data bases from 7 states. Cancer and chemotherapy prevalence data from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program and the National Cancer Data Base were used to calculate national NH rates for 13 cancer types. NH cost was estimated by multiplying charges by institution-specific, cost-to-charge ratios from the 1999 Centers for Medicare and Medicaid Services Hospital Cost Report. NH incidence was projected to national levels using population data from the United States Census and the Centers for Disease Control and Prevention. RESULTS: There were 20,780 discharges with documentation of cancer, chemotherapy, and neutropenia identified. Projecting to national levels, NH incidence was estimated at 60,294 cases (7.83 cases per 1000 cancer patients). The mean NH cost was 13,372 dollars. The mortality rate among patients with NH was estimated at 6.8% or 1 death for every 14 hospitalized patients. Among 13 selected cancer types, the NH rate was 34.20 cases per 1000 patients receiving chemotherapy (1 in 29 patients). NH was particularly common in patients with hematologic tumors, with an incidence of 43.3 cases per 1000 patients with such tumors (1 in 23 patients). The average NH cost for hematologic malignancies was 20,400 dollars, more than double the cost of NH for solid tumors. CONCLUSIONS: According to the current study, NH affects > 60,000 patients with cancer each year in the United States, with an average cost of 13,372 dollars per hospitalization and an associated inpatient mortality rate of 6.8%.