The role of post-translation regulation of Twist expression in the tumor progression of squamous cell carcinoma of head and neck

Squamous cell carcinoma of head and neck (SCCHN) is the tenth most common cancer in the world. Unfortunately, the survival of patients with SCCHN has not improved in the last 40 years. Therefore new targets for therapy are needed, and to this end we are studying signaling pathways activated by IL-6 which we have found stimulates cell migration and soft agar growth in SCCHN. Our data show that IL-6 increases TWIST expression in a transcription-independent mechanism in many SCCHN cell lines. Further investigation reveals TWIST can be phosphorylated upon IL-6 treatment. By computation prediction (http://scansite.mit.edu/motifscan_seq.phtml ), we found that TWIST has a putative phosphorylation site for casein kinase 2 (CK2) suggesting that this kinase could serve as a link between IL-6 stimulation and Twist stability. To test this hypothesis, we used a CK2 inhibitor and shRNA to CK2 and found that these interventions inhibited IL-6 stimulation of TWIST stability. In addition, mutation of the putative CK2 phosphorylation site (S18/S20A) in TWIST decreased the amount of phospho-ATP incorporated by TWIST in an in vitro kinase assay, and altered TWIST stability. In Boyd chamber migration assay and wound-healing assay, the CK2 inhibitor, DMAT, was found to decrease the motility of IL-6 stimulated SCCHN cells and over expression of either a wild-type or the hyperphosphorylated mimicking mutant S18/20D –Twist rather than the hypo-phosphorylated mimicking mutant S18/20A-Twist can promote SCCHN cell motility.To our knowledge, this is the first report to identify the importance of IL-6 stimulated CK2 phosphorylation of TWIST in SCCHN. As CK2 inhibitors are currently under phase I clinical trials, our findings indicate that CK2 may be a viable therapeutic target in SCCHN. Therefore, further pre-clinical studies of this inhibitor are underway.

Attitudes and other barriers to the utilization of clinical research findings by American physicians: A systematic review

Background: The Institute of Medicine estimates that only a maximum of 25% of clinical research findings are incorporated into practice by physicians. To improve clinical practice, efforts have been made to promote evidence-based medicine and the use of clinical guidelines. Despite these efforts, the gap between research and clinical practice remains wide.^ Objective: To systematically review the literature describing the factors which influence the use of clinical research recommendations by American physicians.^ Hypothesis: Barriers exist in the application of clinical research into clinical practice, and are multifactorial. The establishment of the Clinical and Translational Awards (CTSA; special federal grants awarded to selected institutions to support clinical and translational research) has reduced the effect of these barriers and improved the process of clinical research translation into practice among American physicians.^ Aims: Identify barriers and facilitators of the use of research findings in clinical practice by American physicians. Contrast studies published six years before and after the creation of the CTSA.^ Methods: The sources of data include published literature from Medline, PubMed and PsycINFO. Selected studies must be qualitative, a survey of American clinicians, based on evidence-based medicine practice, clinical guidelines or treatment pathways. Systematic reviews and reports were excluded, as well as studies with less than 100 respondents.^ Results: In total, 1036 abstracts were reviewed; 115 full text potential articles were identified and reviewed, and a total of 31 studies met all criteria for inclusion in the final review.^ Conclusions: The barriers against the application of clinical research findings, in the forms of clinical guidelines, evidence-based medicine guides and clinical pathways, can be divided broadly into physician barriers, practice/system barriers and patient barriers. Physician barriers are the most common barriers, especially the lack of familiarity with guidelines and the lack of time. Of the factors which improve the use of research based guidelines, physician factors such as younger age, lower duration of clinical practice, specialty training, and practice in large group Health Maintenance Organization (HMO) settings with fewer patients seen were the most commonly cited.^