Aggressive Salivary Malignancies at Early Stage: Outcomes and Implications for Treatment.

BACKGROUND: Few studies have examined whether the use of adjuvant treatment impacts survival for early stage high-grade salivary tumors. METHODS: A retrospective review of the SEER database between 1973 and 2012 was performed. Patients with high-grade major salivary gland tumors including salivary duct carcinoma, carcinoma ex-pleomorphic adenoma, high-grade mucoepidermoid carcinoma, or adenocarcinoma, NOS were identified. Only stage I-II tumors were included. The impact of radiation status on observed and relative survival was examined. RESULTS: Five hundred seventy-four patients with high-grade, early stage salivary tumors met inclusion criteria. Sixty-seven percent of patients received radiation therapy. There was no difference in observed or relative survival based on having received radiation. CONCLUSIONS: Adjuvant radiation is indicated for advanced stage tumors or early stage tumors with adverse features. For early stage tumors without adverse features, there was no survival benefit from radiation therapy. Adjuvant radiation should be decided on a case-by-case basis for these patients.

Management of complete esophageal stricture after treatment of head and neck cancer using combined anterograde retrograde esophageal dilation.

BACKGROUND: Complete esophageal stricture is a difficult problem to manage. There is limited literature to support clinical decision-making. To evaluate outcomes and efficacy, we performed a retrospective medical chart review of patients who received combined anterograde retrograde esophageal dilation (CARD) between 2002 and 2009 at our institution. METHODS: Fifteen patients were identified who developed a stricture requiring CARD after treatment for head and neck cancers. Outcomes were pretreatment and posttreatment diet, gastrostomy tube status, and operative complications. RESULTS: Six of 15 patients were gastrostomy tube-free at last follow-up and 11 of 15 patients were taking oral nutrition. There were 4 complications. One patient died. Two gastrostomy tube site complications occurred. One patient sustained a dental injury. CONCLUSION: CARD offers benefit to most patients. Despite risks associated with the procedure, CARD should be considered by the clinician and patient in management of complete esophageal stricture.

Nucleotide oligomerization domain-2 interacts with 2'-5'-oligoadenylate synthetase type 2 and enhances RNase-L function in THP-1 cells.

Nucleotide-binding and oligomerization domain-2 (NOD2) is an intracellular protein involved in innate immunity and linked to chronic inflammatory diseases in humans. Further characterization of the full spectrum of proteins capable of binding to NOD2 may provide new insights into its normal functioning as well as the mechanisms by which mutated forms cause disease. Using a proteomics approach to study human THP-1 cells, we have identified 2'-5'-oligoadenylate synthetase type 2 (OAS2), a dsRNA binding protein involved in the pathway that activates RNase-L, as a new binding partner for NOD2. The interaction was confirmed using over-expression of OAS2 and NOD2 in HEK cells. Further confirmation was obtained by detecting NOD2 in immunoprecipitates of endogenous OAS2 in THP-1 cells. Finally, over-expression of NOD2 in THP-1 cells led to enhanced RNase-L activity in cells treated with poly(I:C), a mimic of double-stranded RNA virus infection. These data indicate connectivity in pathways involved in innate immunity to bacteria and viruses and suggest a regulatory role whereby NOD2 enhances the function of RNase-L.

Cyclophilin D inactivation protects axons in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis.

Multiple sclerosis (MS) is the leading cause of neurological disability in young adults, affecting some two million people worldwide. Traditionally, MS has been considered a chronic, inflammatory disorder of the central white matter in which ensuing demyelination results in physical disability [Frohman EM, Racke MK, Raine CS (2006) N Engl J Med 354:942-955]. More recently, MS has become increasingly viewed as a neurodegenerative disorder in which neuronal loss, axonal injury, and atrophy of the CNS lead to permanent neurological and clinical disability. Although axonal pathology and loss in MS has been recognized for >100 years, very little is known about the underlying molecular mechanisms. Progressive axonal loss in MS may stem from a cascade of ionic imbalances initiated by inflammation, leading to mitochondrial dysfunction and energetic deficits that result in mitochondrial and cellular Ca2+ overload. In a murine disease model, experimental autoimmune encephalomyelitis (EAE) mice lacking cyclophilin D (CyPD), a key regulator of the mitochondrial permeability transition pore (PTP), developed EAE, but unlike WT mice, they partially recovered. Examination of the spinal cords of CyPD-knockout mice revealed a striking preservation of axons, despite a similar extent of inflammation. Furthermore, neurons prepared from CyPD-knockout animals were resistant to reactive oxygen and nitrogen species thought to mediate axonal damage in EAE and MS, and brain mitochondria lacking CyPD sequestered substantially higher levels of Ca2+. Our results directly implicate pathological activation of the mitochondrial PTP in the axonal damage occurring during MS and identify CyPD, as well as the PTP, as a potential target for MS neuroprotective therapies.

Properties of the permeability transition pore in mitochondria devoid of Cyclophilin D.

We have studied the properties of the permeability transition pore (PTP) in mitochondria from the liver of mice where the Ppif gene encoding for mitochondrial Cyclophilin D (CyP-D) had been inactivated. Mitochondria from Ppif-/- mice had no CyP-D and displayed a striking desensitization of the PTP to Ca2+, in that pore opening required about twice the Ca2+ load necessary to open the pore in strain-matched, wild-type mitochondria. Mitochondria lacking CyP-D were insensitive to Cyclosporin A (CsA), which increased the Ca2+ retention capacity only in mitochondria from wild-type mice. The PTP response to ubiquinone 0, depolarization, pH, adenine nucleotides, and thiol oxidants was similar in mitochondria from wild-type and Ppif-/- mice. These experiments demonstrate that (i) the PTP can form and open in the absence of CyP-D, (ii) that CyP-D represents the target for PTP inhibition by CsA, and (iii) that CyP-D modulates the sensitivity of the PTP to Ca2+ but not its regulation by the proton electrochemical gradient, adenine nucleotides, and oxidative stress. These results have major implications for our current understanding of the PTP and its modulation in vitro and in vivo.

Interaction of Ler at the LEE5 (tir) operon of enteropathogenic Escherichia coli.

The genome of enteropathogenic Escherichia coli (EPEC) encodes a global regulator, Ler (locus of enterocyte effacement [LEE]-encoded regulator), which activates expression of several polycistronic operons within the 35.6-kb LEE pathogenicity island, including the LEE2-LEE3 divergent operon pair containing overlapping -10 regions and the LEE5 (tir) operon. Ler is a predicted 15-kDa protein that exhibits amino acid similarity with the nucleoid protein H-NS. In order to study Ler-mediated activation of virulence operons in EPEC, we used a molecular approach to characterize the interactions of purified Ler protein with the upstream regulatory sequences of the LEE5 operon. We determined the cis-acting DNA sequences necessary for Ler binding at LEE5 by mobility shift and DNase I protection assays, demonstrating that Ler acts directly at LEE5 by binding sequences between positions -190 and -73 in relation to the transcriptional start site. Based on the molecular weight of Ler, the similarity to H-NS, and the extended region of protection observed in a DNase I footprint at LEE5, we hypothesized that multiple Ler proteins bind upstream of the LEE5 promoter to increase transcriptional activity from a distance. Using an hns deletion strain, we demonstrated that like the LEE2-LEE3 operon pair, H-NS represses LEE5 transcription. We describe a model in which Ler activates transcription at both divergent overlapping paired and single promoters by displacing H-NS, which results in the disruption of a repressing nucleoprotein complex.