Colorectal Neoplasia Differentially Expressed (CRNDE), a Novel Gene with Elevated Expression in Colorectal Adenomas and Adenocarcinomas.

An uncharacterized gene locus (Chr16:hCG_1815491), now named colorectal neoplasia differentially expressed (gene symbol CRNDE), is activated early in colorectal neoplasia. The locus is unrelated to any known protein-coding gene. Microarray analysis of 454 tissue specimens (discovery) and 68 previously untested specimens (validation) showed elevated expression of CRNDE in >90% of colorectal adenomas and adenocarcinomas. These findings were confirmed and extended by exon microarray studies and RT-PCR assays. CRNDE transcription start sites were identified in CaCo2 and HCT116 cells by 5'-RACE. The major transcript isoforms in colorectal cancer (CRC) cell lines and colorectal tissue are CRNDE-a, -b, -d, -e, -f, -h, and -j. Except for CRNDE-d, the known CRNDE splice variants are upregulated in neoplastic colorectal tissue; expression levels for CRNDE-h alone demonstrate a sensitivity of 95% and specificity of 96% for adenoma versus normal tissue. A quantitative RT-PCR assay measuring CRNDE-h RNA levels in plasma was (with a threshold of 2(-ΔCt) = 2.8) positive for 13 of 15 CRC patients (87%) but only 1 of 15 healthy individuals (7%). We conclude that individual CRNDE transcripts show promise as tissue and plasma biomarkers, potentially exhibiting high sensitivity and specificity for colorectal adenomas and cancers.

Relaxant effect of Levosimendan on human uterine contractility in vitro.

OBJECTIVE: Levosimendan, a compound that exerts effects on calcium sensitivity and intracellular free calcium, in addition to opening ATP-sensitive K-channels, is widely used in the treatment of heart failure. Because of its dual mechanism of action, we hypothesized that it would modulate human uterine contractility. STUDY DESIGN: Biopsies of human myometrium were obtained at elective cesarean section (n = 16). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous and oxytocin-induced contractions, were exposed to cumulative additions of levosimendan in the concentration range of 1 nmol/L to 100 mmol/L. In separate experiments, the effects of prior exposure to the K-ATP antagonist glibenclmide (100 mmol) on the effects of levosimendan on myometrial contractility were evaluated. Simultaneous controls were performed for all experiments. RESULTS: Levosimendan exerted an inhibitory effect on spontaneous and agonist induced contractions, when compared with control strips. The mean maximal inhibition (MMI) values were as follows: 45.34% +/- 5.92% for spontaneous contractions (n = 6; P < .05), and 41.88% +/- 5.40% for oxytocin-induced contractions (n = 6; P < .05). The inhibitory effect of levosimendan was significantly antagonized by glibenclamide, resulting in the mean maximal inhibition for levosimendan reduced to 19.04% +/- 3.61% for spontaneous contractions (n = 6; P < .05), and 16.53% +/- 4.08% for oxytocin induced contractions (n = 6; P < .05). CONCLUSION: Levosimendan exerted a potent relaxant effect on spontaneous and agonist-induced human uterine contractility in vitro. This effect was reduced in the presence of K-ATP blockade. Because of the putative role of levosimendan in inflammatory conditions, the findings here may have implications for its future use as therapy for preterm labor.

Expression and modulation of TUB by insulin and thyroid hormone in primary rat and murine 3T3-L1 adipocytes.

tub encodes a protein of poorly understood function, but one implicated strongly in the control of energy balance and insulin sensitivity. Whilst tub expression is particularly prominent in neurones it is also detectable in extraneuronal tissues. We show here, for the first time, expression of TUB protein in rat adipocytes and the murine adipocyte model 3T3-L1 and demonstrate that insulin induces its tyrosine phosphorylation and association with the insulin receptor. TUB expression is regulated developmentally during adipogenic differentiation of 3T3-L1 cells and in response to cell treatment with thyroid hormone or induction of insulin resistance. TUB was upregulated 5- to 10-fold in adipocytes from obese Zucker rats and 3T3-L1 adipocytes that had been rendered insulin resistant, a response that could be antagonised by rosiglitasone, an insulin-sensitising drug. Our data are consistent with a previously unforeseen role for TUB in insulin signalling and fuel homeostasis in adipocytes.

Umbilical artery tone in maternal obesity.

BACKGROUND: The increasing prevalence of obesity constitutes a major health problem in obstetrics with implications for feto-maternal growth and wellbeing. This study investigated and compared the contractile properties of umbilical arteries excised from obese women, with those excised from women with a normal body mass index (BMI). METHODS: Sections of umbilical artery were obtained from umbilical cord samples immediately after delivery and mounted for isometric recording in organ tissue baths under physiological conditions. Cumulative additions of 5-Hydroxytryptamine (5-HT) and Prostaglandin F-2alpha (PgF2alpha) were added in the concentration range of 1 nmol/L to 10 micromol/L. Control vessels were exposed to Krebs physiological salt solution (PSS) only. The resultant effects of each drug addition were measured using the Powerlab hardware unit. RESULTS: 5-HT exerted a significant effect on human umbilical artery tone at concentrations of 100 nmol/L, 1 micromol/L, and 10 micromol/L in normal (n = 5; P < 0.05) and obese (n = 5; P < 0.05) women. The contractile effect was significantly greater in vessels from obese women {Mean Maximum Tension (MMT) = 4.2532 g} than in those from women of normal BMI (MMT = 2.97 g; P < 0.05). PgF2alpha exerted a significant contractile effect on vessels at 1 micromol/L and 10 micromol/L concentrations when compared with controls (n = 5; P < 0.05). There was a non-significant trend towards an enhanced tone response in vessels from obese women (MMT = 3.02 g; n = 5), in comparison to vessels from women of a normal BMI (MMT = 2.358 g; n = 5; P > 0.05). CONCLUSION: These findings support the hypothesis that endogenous regulation of umbilical artery tone is altered in association with maternal obesity. This may be linked to the cardiovascular effects of secretory products of adipose tissue, with implications for the feto-maternal circulation.

Histone deacetylase inhibitors and a functional potent inhibitory effect on human uterine contractility.

OBJECTIVE: This study was undertaken to investigate the effects of 3 histone deacetylase inhibitors on human uterine contractility. STUDY DESIGN: Biopsy specimens of human myometrium were obtained at elective cesarean section (n = 18). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous, and oxytocin-induced contractions, were subjected to cumulative additions of 3 histone deacetylase inhibitors: trichostatin A, suberic bishydroxamate (1 nmol/L-10 micromol/L) and valproic acid (100 nmol/L--1 mmol/L). Control experiments were run simultaneously. Integrals of contractile activity were measured by using the PowerLab hardware unit and Chart v3.6 software. Data were analyzed by using 1-way analysis of variance, followed by post hoc analysis. RESULTS: All 3 histone deacetylase inhibitor compounds exerted a potent and cumulative inhibitory effect on spontaneous (n = 18) and oxytocin-induced (n =18) contractility. The mean maximal inhibition values for the 3 compounds were as follows: trichostatin A, 46-54% (P < .05); valproic acid, 35-36% (P < .05); and suberic bishydroxamate, 53-65% (P < .05). CONCLUSION: The histone deacetylase inhibitors trichostatin A, valproic acid, and suberic bishydroxamate exerted a potent inhibitory effect on human uterine contractions. This raises the possibility that this new class of compounds may have tocolytic potential, in addition to their current clinical indications. We speculate that this inhibitory effect may be linked, at least in part, to the ability of histone deacetylase inhibitors to induce the expression of genes involved in maintaining myometrial quiescence via epigenetic mechanisms but may also potentially involve nonepigenetic pathways.

The relaxant effect of nifedipine in human uterine smooth muscle and the BK(Ca) channel.

OBJECTIVE: The purpose of this study was to investigate the effects of K+ channel blockade on the uterorelaxant effects of nifedipine in human myometrium during pregnancy. STUDY DESIGN: Biopsies of human myometrium were obtained at elective cesarean section (n = 24). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous and oxytocin-induced contractions, were subjected to K+ channel blockade using tetraethylammonium (TEA) or iberiotoxin (IbTX) followed by cumulative additions of nifedipine (1 nmol/L-10 micromol/L). Control experiments were run simultaneously. Integrals of contractile activity were measured using the PowerLab hardware unit and Chart v3.6 software. Data were analyzed using one-way analysis of variance (ANOVA) followed by post hoc analysis. RESULTS: Nifedipine exerted a potent and cumulative inhibitory effect on spontaneous contractions and oxytocin-induced contractions in human myometrium in vitro, in comparison to control measurements (P < .05, n = 6). Incubation of strips with TEA or IbTX, prior to addition of nifedipine, significantly attenuated the relaxant effect exerted by nifedipine (P < .05, n = 6). CONCLUSION: This study demonstrates that the uterorelaxant effect of nifedipine is attenuated by potassium channel (K+) blockade. This suggests that K+ channel conductance, and particularly the BK(Ca) channel, plays a role in the potent relaxant effect of nifedipine, hitherto presumed to act solely through L-gated calcium channels.

Inhibitory effect of leptin on human uterine contractility in vitro.

OBJECTIVE: The purpose of this study was to investigate the effects of leptin on human uterine contractility in vitro. STUDY DESIGN: Biopsies of human myometrium were obtained at elective cesarean section (n = 18). Dissected myometrial strips suspended under isometric conditions, undergoing spontaneous and oxytocin-induced contractions, were exposed to cumulative additions of leptin in the concentration range of 1 nmol/L to 1 micromol/L. Control strips were run simultaneously. Integrals of contractile activity were measured using the PowerLab hardware unit and Chart v3.6 software. RESULTS: Leptin exerted a potent and cumulative inhibitory effect on spontaneous and oxytocin-induced contractions compared to control strips. The mean maximal inhibition values were as follows: 46.794 +/- 5.133% (n = 6; P < .001) for spontaneous contractions and 42.323 +/- 3.692% (n = 6; P < .001) for oxytocin-induced contractions. There was an apparent reduction in both frequency and amplitude of contractions. CONCLUSION: This physiologic inhibitory effect of leptin on uterine contractility may play a role in the dysfunctional labor process associated with maternal obesity, and the resultant high cesarean section rates.