MDM2 gene amplification and protein expressions in colon carcinoma: is targeting MDM2 a new therapeutic option?

The aim of this study was to investigate murine double minute-2 (MDM2) gene copy number changes in colon carcinoma and to correlate these findings with an immunohistochemical analysis of MDM2 protein expression and histopathologic prognostic indicators of the tumors. The study included 80 cases of sporadic colon carcinomas. MDM2 protein expression was assessed by immunohistochemistry, and MDM2 gene status by fluorescence in situ hybridization. MDM2 gene amplification was detected in 18% of the 80 cases examined. A strong correlation was found between MDM2 gene amplification and the presence, intensity, and staining proportion of cytoplasmic MDM2 protein expression (p = 0.01). No correlation was found between MDM2 gene amplification and the well-established histopathologic prognostic factors. Given the correlation with gene amplification, we clearly demonstrated that cytoplasmic expression of MDM2 protein is true and relevant and that this finding has to be taken into account when immunohistochemistry would be used as a screening for MDM2 gene amplification in the near future. Targeting MDM2 could be a new approach in colon cancer therapy. The amplification status could be a predictive factor of the response to MDM2-targeted therapy.     

The loss and progressive recovery of voiding after spinal cord interruption in rats is associated with simultaneous changes in autonomous contractile bladder activity

Background

Autonomous contractile activity (ACA) is a well-known phenomenon in isolated bladders from different species and seems to be important in the physiology of both normal and dysfunctional voiding.

Objective

To determine whether ACA is changed in bladders from paraplegic rats at different periods post–spinal cord injury (post-SCI).

Design, setting, and participants

ACA was studied in bladders (at least six per group) from normal and paraplegic female Wister rats at different times post-SCI (2 h, 24 h, 1 wk, and 3 wk). A group of normal rats was used as a control group. For measurements bladders were incubated in organ baths under standardised conditions.

Measurements

ACA was measured as pressure change, which was defined as either a transient change or a spiked change according to its characteristics. The effects of intravesical volume load and muscarinic agonists were studied.

Results and limitations

Following spinal cord injury (SCI) a clear evolution in ACA was observed. In bladders from SCI rats in the acute areflexive voiding phase (1 wk post-SCI), we observed decreased ACA associated with a highly increased compliance and a changed response to muscarinic agonists. ACA in bladders from SCI rats with renewed voiding reflexes (3 wk post-SCI) was increased, together with a moderately increased compliance and a (moderately) changed response to muscarinic agonists.

Conclusions

From these observations it is apparent that SCI leads to alterations in the behaviour and muscarinic response of ACA in the isolated bladder. These changes in ACA may play an important role in the pathophysiology of overactive bladder disease (OAB), and interacting with changed ACA might be promising in the search for newer treatments for OAB.     

The human CMV-UL86 peptide 981-1003 shares a crossreactive T-cell epitope with the encephalitogenic MOG peptide 34-56, but lacks the capacity to induce EAE in rhesus monkeys

Rhesus monkeys immunized with MOG(34-56), a dominant T-cell epitope from myelin/oligodendrocyte glycoprotein, develop an acute neurological disease resembling acute disseminated encephalomyelitis (ADEM) in humans. The typical large demyelinated lesions and mononuclear infiltrates in the monkey brains are caused by MOG(34-56) T-cells. We show that MOG(34-56)-reactive CD4+ and CD8+ T-cells are induced in monkeys immunized with a peptide from the human CMV major capsid protein (UL86; 981-1003), that shares sequence similarity with MOG(34-56). Monkeys sensitized against the viral peptide and subsequently challenged with MOG(34-56) display histological signs of encephalitis, but do not show overt neurological signs.     

Neonatal screening for congenital hypothyroidism in the Netherlands: cognitive and motor outcome at 10 years of age

CONTEXT: Patients with thyroidal congenital hypothyroidism (CH-T) born in The Netherlands in 1981-1982 showed persistent intellectual and motor deficits during childhood and adulthood, despite initiation of T(4) supplementation at a median age of 28 d after birth. OBJECTIVE: The present study examined whether advancement of treatment initiation to 20 d had resulted in improved cognitive and motor outcome. DESIGN/SETTING/PATIENTS: In 82 Dutch CH-T patients, born in 1992 to 1993 and treated at a median age of 20 d (mean, 22 d; range, 2-73 d), cognitive and motor outcome was assessed (mean age, 10.5 yr; range, 9.6-11.4 yr). Severity of CH-T was classified according to pretreatment free T(4) concentration. MAIN OUTCOME MEASURE: Cognitive and motor outcome of the 1992-1993 cohort in comparison to the 1981 to 1982 cohort was the main outcome measure. RESULTS: Patients with severe CH-T had lower full-scale (93.7), verbal (94.9), and performance (93.9) IQ scores than the normative population (P < 0.05), whereas IQ scores of patients with moderate and mild CH-T were comparable to those of the normative population. In all three severity subgroups, significant motor problems were observed, most pronounced in the severe CH-T group. No correlations were found between starting day of treatment and IQ or motor outcome. CONCLUSIONS: Essentially, findings from the 1992-1993 cohort were similar to those of the 1981-1982 cohort. Apparently, advancing initiation of T(4) supplementation from 28 to 20 d after birth did not result in improved cognitive or motor outcome in CH-T patients.     

Generation of monoclonal antibodies to the AML1-ETO fusion protein: strategies for overcoming high homology

The chromosomal translocation t(8;21) often found in acute myeloid leukemia generates an oncogenic fusion protein AML1-ETO. This chimeric oncoprotein disrupts wild-type AML1 function and dysregulates genes important for normal myelopoiesis. Monoclonal antibodies that can capture and detect the AML1-ETO fusion protein would help with early diagnosis and treatment prognosis of acute myeloid leukemia. We report the development of murine monoclonal antibodies (MAbs) that specifically bind epitopes encoded by either AML1 or ETO. Since alignment to the human ETO protein indicated almost 100% homology to the mouse ortholog, a strategy was needed to instruct humoral immunity in mice to focus and respond to self-epitopes. Our strategy to develop capture/detector reagents involved producing MAbs that would bind to epitopes within the non-fused myelopic protein (i.e., either AML1 or ETO). This included a process to select antibodies for their ability to also recognize the translocated chromosomal AML1-ETO fusion protein and to identify complementary capture/detector antibody pairs. Construction of a peptide hapten-carrier complex and use of a rapid immunization protocol resulted in IgM-IgG ETO specific MAbs. These MAbs bound specifically to a recombinant form of AML1-ETO fusion protein expressed in HEK and to an endogenous AML1-ETO form of the fusion protein expressed in Kasumi-1. We report the development of murine hybridoma MAbs derived from immunizations with a peptide "self-epitope." Our findings provide a potential strategy to instruct humoral immunity in mice to focus and respond to self-epitopes. This strategy has been validated with the oncogenic fusion protein AML1-ETO involved in acute myeloid leukemia.