NEDD9/Arf6-dependent endocytic trafficking of matrix metalloproteinase 14: a novel mechanism for blocking mesenchymal cell invasion and metastasis of breast cancer.

NEDD9 is an established marker of invasive and metastatic cancers. NEDD9 downregulation has been shown to dramatically reduce cell invasion and metastasis in multiple tumors. The mechanisms by which NEDD9 regulates invasion are largely unknown. In the current study, we have found that NEDD9 is required for matrix metalloproteinase 14 (MMP14) enzymatic recovery/recycling through the late endosomes to enable disengagement of tissue inhibitor of matrix metalloproteinase 2 (TIMP2) and tumor invasion. Depletion of NEDD9 decreases targeting of the MMP14/TIMP2 complex to late endosomes and increases trafficking of MMP14 from early/sorting endosomes back to the surface in a small GTPase ADP ribosylation factor-6 (Arf6)-dependent manner. NEDD9 directly binds to Arf6-GTPase-activating protein, ARAP3 and Arf6-effector GGA3, thereby facilitating the Arf6 inactivation required for MMP14/TIMP2 targeting to late endosomes. Re-expression of NEDD9 or a decrease in Arf6 activity is sufficient to restore MMP14 activity and the invasive properties of tumor cells. Importantly, NEDD9 inhibition by Vivo-Morpholinos, an antisense therapy, decreases primary tumor growth and metastasis in xenograft models of breast cancer. Collectively, our findings uncover a novel mechanism to control tumor-cell dissemination through NEDD9/Arf6-dependent regulation of MMP14/TIMP2 trafficking, and validate NEDD9 as a clinically relevant therapeutic target to treat metastatic cancer.

Factors related to decision making and substance use in adolescent survivors of childhood cancer: a presenting clinical profile.

BACKGROUND: Adolescent survivors of childhood cancer are more vulnerable to the consequences of health risk behaviors because of the late effects of their disease and its treatment. Decision making related to risk behaviors is important as they have reached an age during which initiation of substance use risk behavior is common. OBJECTIVE: Factors associated with decision making and substance use behaviors (smoking, alcohol use, and illicit drug use) were identified among adolescent survivors of childhood cancer, the role of cognitive function was examined, and their rates of substance use behaviors were compared to a sample from the general population. METHODS: A cohort of 243 adolescent survivors, ages 14-19 years, participated who were recruited from three cancer centers (St. Jude Children's Research Hospital, Hackensack University, and Long Beach Medical Center). A cross-sectional survey was used to assess cognitive and psychosocial factors for a presenting clinical profile to predict quality decision making and substance use behaviors. Validated measures using online data entry were obtained at the time of their annual visit for evaluation of late effects of treatment. Cancer and treatment factors were abstracted from the medical record. Eight factors (nine for substance use risk behavior) were examined in two regression models, quality decision making and substance use. RESULTS: In the model to predict poor-quality decision making for this cohort, gender and risk motivation (a surrogate for resiliency to social influence) were each significant predictors, with male gender and less resiliency each associated with poor decision making. Significant predictors of lifetime substance use were older presenting age, lower resiliency to social influence, poorer abstract ability (representing executive function impairment), history of current school problems, and negative substance use risk behavior modeling by household members and closest friend; CNS-associated late effects were only marginally associated. For current substance use, three factors remained significant in this cohort: older presenting age, lower resiliency, and negative risk behavior modeling. IMPLICATIONS FOR CANCER SURVIVORS: Study results characterize a presenting clinical profile for adolescent survivors with poor-quality decision making regarding substance use risk behaviors that will be helpful to health professionals counseling teen survivors about the impact of risk behaviors on disease-and treatment-related late effects.

A comparison of developmental versus functional assessment in the rehabilitation of young children.

BACKGROUND: The purpose of this study was to explore the differences in and potential uses of information derived from developmental vs. functional assessment during the acute rehabilitation of very young children with acquired brain injury. Both methods of assessment are typically used during hospitalization in order to assist in developing individualized goals and outcome measures. With the trend of shortened hospital stays, effective assessment for determining optimal treatment goals and outcomes becomes increasingly important. The results from a developmental and a functional assessment obtained on 23 inpatient children below 6 years of age who had experienced either an acquired brain injury or encephalitis were compared. The data was collected through a retrospective chart review spanning 4 years. METHODS AND OUTCOME MEASURES: Each child received a cognitive and a language test using either the Early Learning Accomplishment Profile (E-LAP) or the Learning Accomplishment Profile Diagnostic (LAP-D) for the developmental assessment measure. The Functional Independence Measure for Children (WeeFIM) was used as a functional assessment. Summary statistics and frequencies were calculated for variables including age and diagnosis. Partial Pearson correlations and 95% confidence intervals were calculated between the functional and developmental assessments, adjusting for the amount of time between administrations of the two exams. Pearson correlations were computed between length of hospital stay and performance on the developmental and functional quotients. RESULTS: Moderate, statistically significant Pearson partial correlations were found between the E-LAP/LAP-D cognitive quotient and the WeeFIM cognitive quotient (r = 0.42, 95% CI (0, 0.72)), the E-LAP/LAP-D language quotient and the WeeFIM cognitive quotient (r = 0.55, 95% CI (0.17, 0.79)) and the E-LAP/LAP-D cognitive quotient and the WeeFIM total quotient (r = 0.50, 95% CI (0.10, 0.76)). An inverse correlation was found between the length of stay and the E-LAP/ LAP-D cognitive quotient (r = -0.68, 95% CI (-0.86, -0.34)) as well as the E-LAP/LAP-D language quotient (r = -0.61, 95% CI (-0.83, -0.23)). CONCLUSIONS: The moderate but limited correlations between developmental and functional assessments may be attributed to differences in the two forms of assessment including the test items, their administration and scoring. While both forms of assessment were thought to be useful for developing individualized treatment goals and measuring outcomes, there were advantages and disadvantages to each.

Molecular targets for tumour progression in gastrointestinal stromal tumours.

BACKGROUND AND AIMS: The distinction between benign and malignant gastrointestinal stromal tumours (GISTs) is often unclear at the clinical and histopathology levels. GISTs are believed to arise from the stem cells of Cajal. In order to define genetic biomarkers and identify target genes related to GIST progression, we analysed and compared benign and malignant GISTs with verified follow up data using cDNA expression arrays. METHODS: Eight genes were frequently overexpressed in malignant GISTs and their overexpression was confirmed using quantitative real time reverse transcription-polymerase chain reaction. These genes included ezrin (villin 2 (VIL2)), collagen 8 alpha 1 subunit (COL8A1), G2/mitotic specific cyclin B1 (CCNB1), high mobility group protein (HMG2), TSG101 tumour susceptibility protein, CENP-F kinetochore protein, protein tyrosine kinase 2 (FAK), and protein kinase DYRK2. To test these genes in a clinical setting, we obtained diagnostic samples of 16 additional GISTs that were classified at diagnosis as benign, malignant, and uncertain malignant potential (UMP). RESULTS: There was remarkable gene overexpression in all malignant GISTs. Statistical analyses revealed significant correlations between overexpression of several gene pairs in malignant GISTs. We found the strongest correlations (rho>0.70) among the significant correlations (p<0.01) between CCNB1-CENP-F (rho = 0.87) and CCNB1-FAK (rho = 0.73). Gene expression of the UMP GISTs suggested two different groups. Three UMP GISTs had gene expression consistent with malignant tumours and their follow up data revealed that indeed these patients had recurrences later on. On the other hand, UMP GISTs that had low gene expression levels continued free of disease for several years. CONCLUSIONS: These results provide insight into the oncogenesis of GISTs and suggest that testing the expression profile of a number of genes may segregate GISTs into groups of different tumour behaviour.

The relationship between plasma t-PA and PAI-1 levels is dependent on epistatic effects of the ACE I/D and PAI-1 4G/5G polymorphisms.

Thrombus formation and degradation is partly due to a complex interplay between tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1). There is accumulating evidence that plasma levels of t-PA and PAI-1 may be influenced by an interaction between the fibrinolytic and renin-angiotensin systems. The goal of this study was to conduct an exploratory data analysis to determine whether there is evidence that the relationship (i.e. correlation) between plasma t-PA and PAI-1 is influenced by interactive effects of the angiotensin converting enzyme (ACE) insertion/deletion (I/D) and plasminogen activator inhibitor 1 (PAI-1) 4G/5G polymorphisms in a sample of 50 unrelated African Americans and 117 unrelated Caucasians. In a single-locus analysis, no evidence for heterogeneity of plasma t-PA and PAI-1 correlations among either ACE I/D or PAI-1 4G/5G genotypes was detected. However, using the combinatorial partitioning method for exploratory data analysis, we identified evidence that is suggestive of heterogeneity of plasma t-PA and PAI-1 correlations among multilocus ACE I/D and PAI-1 4G/5G genotypes in African American females, Caucasian females, Caucasian males, but not African American males. From these results, we propose as a working hypothesis that the correlation between plasma t-PA and PAI-1 may be dependent on epistatic effects of the ACE I/D and PAI-1 4G/5G polymorphisms. This study supports the idea that interactions between the fibrinolytic and renin-angiotensin systems play an important role in the genetic architecture of plasma t-PA and PAI-1.