Response of head and neck squamous cell carcinoma cells carrying PIK3CA mutations to selected targeted therapies.

IMPORTANCE: The PIK3CA mutation is one of the most common mutations in head and neck squamous cell carcinoma (HNSCC). Through this research we attempt to elicit the role of oncogene dependence and effects of targeted therapy on this PIK3CA mutation. OBJECTIVES: (1) To determine the role of oncogene dependence on PIK3CA-one of the more common and targetable oncogenes in HNSCC, and (2) to evaluate the consequence of this oncogene on the effectiveness of newly developed targeted therapies. DESIGN, SETTING, AND PARTICIPANTS: This was a cell culture-based, in vitro study performed at an academic research laboratory assessing the viability of PIK3CA-mutated head and neck cell lines when treated with targeted therapy. EXPOSURES: PIK3CA-mutated head and neck cell lines were treated with 17-AAG, GDC-0941, trametinib, and BEZ-235. MAIN OUTCOMES AND MEASURES: Assessment of cell viability of HNSCC cell lines characterized for PIK3CA mutations or SCC25 cells engineered to express the PIK3CA hotspot mutations E545K or H1047R. RESULTS: Surprisingly, in engineered cell lines, the hotspot E545K and H1047R mutations conferred increased, rather than reduced, IC50 assay measurements when treated with the respective HSP90, PI3K, and MEK inhibitors, 17-AAG, GDC-0941, and trametinib, compared with the SCC25 control cell lines. When treated with BEZ-235, H1047R-expressing cell lines showed increased sensitivity to inhibition compared with control, whereas those expressing E545K showed slightly increased sensitivity of unclear significance. CONCLUSIONS AND RELEVANCE: (1) The PIK3CA mutations within our engineered cell model did not lead to enhanced oncogene-dependent cell death when treated with direct inhibition of the PI3K enzyme yet did show increased sensitivity compared with control with dual PI3K/mTOR inhibition. (2) Oncogene addiction to PIK3CA hotspot mutations, if it occurs, is likely to evolve in vivo in the context of additional molecular changes that remain to be identified. Additional study is required to develop new model systems and approaches to determine the role of targeted therapy in the treatment of PI3K-overactive HNSCC tumors.

Otolaryngology and medical malpractice: A review of the past decade, 2001-2011.

OBJECTIVES/HYPOTHESIS: To better understand the causes and outcomes of lawsuits involving otolaryngologists in the past decade by analyzing malpractice litigation trends to prevent future litigation and improve physician education. STUDY DESIGN: Analysis of a national database for all US civil trials. METHODS: The Westlaw database was reviewed from 2001 to 2011. Data were compiled on the demographics of the plaintiffs, use of expert witnesses, procedures, nature of the injury, legal allegations, verdicts, and indemnities. RESULTS: One hundred ninety-eight cases met inclusion criteria. Verdicts for the defendant/otolaryngologist predominated (58%), whereas the average award when the verdict favored the plaintiff was $1,782,514. When otolaryngologists were used as expert witnesses by the defense, the verdict outcome statistically favored the defendant. Two of the most commonly cited legal allegations were improper performance and failure to diagnose and treat. Fifty-one cases involved allegations of wrongful death, with the overall outcome favoring the plaintiffs (51%). The average indemnities in these cases were significantly higher for plaintiff verdicts at $2,552,580 versus settlements at $992,896. Forty-two cases involved malignancy, with the two most common allegations being failure to diagnose and treat (79%) and delay in diagnosis (74%). CONCLUSIONS: Our study reveals that in the past decade, in significant malpractice litigations, overall outcomes favored otolaryngologists. The average awards was significantly higher when cases involved malignancy. Our analysis reveals the importance of meticulous surgical techniques and thorough preoperative evaluations. Last, when otolaryngologists are defendants in litigation, our review reiterates the value of the otolaryngologist as the defense's expert witnesses.

RNA interference of transforming growth factor-ß 2 in human respiratory fibroblasts.

OBJECTIVE: Transforming growth factor-ß2 (TGF-ß2) is a principal cytokine of interest in the pathogenesis of scar formation and is a potential target for future molecular-based adjunctive therapies. The authors hypothesize that interfering RNA (RNAi) can be used to modulate TGF-ß2 production in cultured human respiratory fibroblasts. STUDY DESIGN: Basic science. Setting. Laboratory. SUBJECTS AND METHODS: RNAi constructs targeted to the TGF-ß2 transcript were complexed with microsomal lipids and applied to human fibroblasts in cell culture. Transfection efficiency and cell viability were measured by fluorescence microscopy. Messenger RNA (mRNA) for TGF-ß2 was measured 48 hours posttransfection using real-time quantitative PCR. The quantity of TGF-ß2 protein produced with increasing concentrations of RNAi was measured using enzyme-linked immunosorbent assay. The function of RNAi-treated fibroblasts was tested using a wound-healing assay. RESULTS: Transfection efficiency of more than 80% was achieved with minimal induced cell death. Treated cells showed selective knockdown of 80% of TGF-ß2 mRNA, which was confirmed with negative controls. As the concentration of RNAi was increased, an incremental decrease in TGF-ß2 protein was measured. CONCLUSION: RNAi technology is an effective means of localized and transient gene silencing in cultured human fibroblasts. Transfection can be achieved using microsome complexed RNAi with minimal induced cell death. This preliminary result shows promise for future in vitro studies.

Role of the otolaryngologist in the treatment of struma ovarii.

Struma ovarii, a rare germ cell tumor of the ovary composed of >50% thyroid tissue, is traditionally managed by gynecologic surgeons. Although struma ovarii is typically cured by simple excision, otolaryngology-head and neck surgeons may play a critical role in caring for these patients. In this article, we present two cases of struma ovarii and discuss the role of the otolaryngologist.

Efficacy of telavancin in the treatment of methicillin-resistant Staphylococcus aureus osteomyelitis: studies with a rabbit model.

OBJECTIVES: Staphylococcus aureus is the most common pathogen isolated in osteomyelitis. This study evaluated the efficacies of telavancin (an investigational, rapidly bactericidal lipoglycopeptide with a multifunctional mechanism of action against Gram-positive bacteria), vancomycin and linezolid in a rabbit methicillin-resistant S. aureus (MRSA) osteomyelitis model. METHODS: Localized osteomyelitis was induced in New Zealand White rabbits by percutaneous injection of 10(6) cfu of MRSA clinical isolate 168-1 into the intramedullary cavity. Two weeks post-infection, rabbits with radiographically confirmed, localized proximal tibial osteomyelitis were randomized into four groups (n = 15 per group): untreated controls; vancomycin 30 mg/kg subcutaneously every 12 h; linezolid 60 mg/kg orally every 8 h; and telavancin 30 mg/kg subcutaneously every 12 h. After 4 weeks of antibiotic treatment, animals were left untreated for 2 weeks. Rabbits were then euthanized and the tibias harvested. Bone matrix and marrow from each tibia were cultured and bacterial counts determined. RESULTS: For MRSA isolate 168-1, the MIC was 0.25 mg/L for telavancin, 0.5 mg/L for vancomycin and 0.5 mg/L for linezolid. Tibial cultures were positive for MRSA in 9 of 15 (60%) untreated controls, and 3 of 15 (20%) telavancin-treated, 3 of 15 (20%) vancomycin-treated and 4 of 14 (29%) linezolid-treated rabbits. CONCLUSIONS: Telavancin has comparable efficacy to vancomycin and linezolid in a rabbit model of MRSA osteomyelitis.