Phosphorothioate antisense oligonucleotides induce the formation of nuclear bodies

Antisense oligonucleotides are powerful tools for the in vivo regulation of gene expression. We have characterized the intracellular distribution of fluorescently tagged phosphorothioate oligodeoxynucleotides (PS-ONs) at high resolution under conditions in which PS-ONs have the potential to display antisense activity. Under these conditions PS-ONs predominantly localized to the cell nucleus where they accumulated in 20-30 bright spherical foci designated phosphorothioate bodies (PS bodies), which were set against a diffuse nucleoplasmic population excluding nucleoli. PS bodies are nuclear structures that formed in cells after PS-ON delivery by transfection agents or microinjection but were observed irrespectively of antisense activity or sequence. Ultrastructurally, PS bodies corresponded to electron-dense structures of 150-300 nm diameter and resembled nuclear bodies that were found with lower frequency in cells lacking PS-ONs. The environment of a living cell was required for the de novo formation of PS bodies, which occurred within minutes after the introduction of PS-ONs. PS bodies were stable entities that underwent noticeable reorganization only during mitosis. Upon exit from mitosis, PS bodies were assembled de novo from diffuse PS-ON pools in the daughter nuclei. In situ fractionation demonstrated an association of PS-ONs with the nuclear matrix. Taken together, our data provide evidence for the formation of a nuclear body in cells after introduction of phosphorothioate oligodeoxynucleotides

Minimally invasive techniques for head and neck malignancies: current indications, outcomes and future directions

Item does not contain fulltextThe trend toward minimally invasive surgery, appropriately applied, has evolved over the past three decades to encompass all fields of surgery, including curative intent cancer surgery of the head and neck. Proper patient and tumor selection are fundamental to optimizing oncological and functional outcomes in such a personalized approach to cancer treatment. Training, experience, and appropriate technological equipment are prerequisites for any type of minimally invasive surgery. The aim of this review was to provide an overview of currently available techniques and the evidence justifying their use. Much evidence is in favor of routine use of transoral laser resection, transoral robot-assisted surgery, transnasal endoscopic resection, sentinel node biopsy, and endoscopic neck surgery for selected malignant tumors, by experienced surgical teams. Technological advances will enhance the scope of this type of surgery in the future and physicians need to be aware of the current applications and trends