The hypoxic environment of tumors dictates the phenotype of local myeloid-derived suppressor cells (MDSCs) via HIF-1a expression; hypoxia converts splenic MDSCs from specific into nonspecific suppressors.

Myeloid-derived suppressor cells (MDSC) are a major component of the immune suppressive network described in cancer and many other pathological conditions. Recent studies have demonstrated that one of the major mechanisms of MDSC-induced immune suppression is mediated by reactive oxygen species (ROS). However, the mechanism of this phenomenon remained unknown. In this study, we observed a substantial up-regulation of ROS by MDSC in all of seven different tumor models and in patients with head and neck cancer. The increased ROS production by MDSC is mediated by up-regulated activity of NADPH oxidase (NOX2). MDSC from tumor-bearing mice had significantly higher expression of NOX2 subunits, primarily p47phox and gp91phox, compared with immature myeloid cells from tumor-free mice. Expression of NOX2 subunits in MDSC was controlled by the STAT3 transcription factor. In the absence of NOX2 activity, MDSC lost the ability to suppress T cell responses and quickly differentiated into mature macrophages and dendritic cells. These findings expand our fundamental understanding of the biology of MDSC and may also open new opportunities for therapeutic regulation of these cells in cancer.

Professional antigen presenting cells, dendritic cells (DC) are responsible for initiation and maintenance of immune responses. Here, we report that a substantial proportion of DCs in tumor-bearing mice and cancer patients have increased levels of triglycerides. Lipid accumulation in DCs was caused by increased uptake of extracellular lipids due to up-regulation of scavenger receptor A. DCs with high lipid content were not able to effectively stimulate allogeneic T cells or present tumor-associated antigens. DCs with high and normal lipid levels did not differ in expression of MHC and co-stimulatory molecules. However, lipid-laden DCs had reduced capacity to process antigens. Pharmacological normalization of lipid levels in DCs with an inhibitor of acetyl-CoA carboxylase restored the functional activity of DCs and substantially enhanced the effects of a cancer vaccine. These findings support the regulation of immune responses in cancer by manipulation of lipid levels in DCs.

Objective To present 5-year outcomes from a prospective cohort of patients with obstructive sleep apnea (OSA) who were treated with upper airway stimulation (UAS) via a unilateral hypoglossal nerve implant. Study Design A multicenter prospective cohort study. Setting Industry-supported multicenter academic and clinical trial. Methods From a cohort of 126 patients, 97 completed protocol, and 71 consented to a voluntary polysomnogram. Those having continuous positive airway pressure failure with moderate to severe OSA, body mass index <32 kg/m, and no unfavorable collapse on drug-induced sleep endoscopy were enrolled in a phase 3 trial. Prospective outcomes included apnea-hypopnea index (AHI), oxygen desaturation index, and adverse events, as well as measures of sleepiness, quality of life, and snoring. Results Patients who did and did not complete the protocol differed in baseline AHI, oxygen desaturation index, and Functional Outcomes of Sleep Questionnaire scores but not in any other demographics or treatment response measures. Improvement in sleepiness (Epworth Sleepiness Scale) and quality of life was observed, with normalization of scores increasing from 33% to 78% and 15% to 67%, respectively. AHI response rate (AHI <20 events per hour and >50% reduction) was 75% (n = 71). When a last observation carried forward analysis was applied, the responder rate was 63% at 5 years. Serious device-related events all related to lead/device adjustments were reported in 6% of patients. Conclusions Improvements in sleepiness, quality of life, and respiratory outcomes are observed with 5 years of UAS. Serious adverse events are uncommon. UAS is a nonanatomic surgical treatment with long-term benefit for individuals with moderate to severe OSA who have failed nasal continuous positive airway pressure.

O bstructive sleep apnea (OSA) is a common disorder that affects sleep and quality of life. Because many people with OSA cannot or will not comply with the standard treatment with a continuous positive airway pressure (CPAP) mask, alternative treatments have been sought. Upper-airway stimulation using unilateral stimulation of the hypoglossal nerve is a possible option. This multicenter, prospective, single-group, cohort trial and a follow-up randomized therapy-withdrawal trial were performed to evaluate the clinical safety and effectiveness of upper-airway stimulation for treating moderate to severe OSA.Patients who had difficulty accepting or adhering to CPAP treatment were included and served as their own controls. After initial screening, including polysomnography, qualified patients underwent surgery to implant the upper-airway stimulation system in which a stimulation electrode was placed on the hypoglossal nerve to recruit tongue-protrusion function. The sensing lead was placed between the internal and external intercostal muscles to detect ventilatory effort, and the neurostimulator was implanted in the right ipsilateral midinfraclavicular region. A month after implantation, patients had a second baseline diagnostic polysomnographic exam before the device was activated. Patients used a controller to initiate and stop therapy each night and then were assessed at 2, 3, 6, 9, and 12 months. The primary outcome was the change in the severity of OSA as determined by the apneahypopnea index (AHI; number of apnea or hypopnea events per hour; score ≥15 indicates moderate to severe OSA) and the O 2 desaturation index (ODI; number of times per hour of sleep that the blood O 2 level drops by ≥4 percentage points from baseline). At the 12-month assessment, a response to treatment was defined as an AHI reduction of 50% or greater from baseline and a score of less than 20 events per hour along with an ODI reduction of 25% or greater from baseline. The primary efficacy objectives were response rates of 50% or greater as assessed in the AHI and ODI. Secondary outcomes were the Epworth Sleepiness Scale, the Functional Outcomes of Sleep Questionnaire (FOSQ), and the percentage of sleep time with the O 2 saturation of less than 90%. Consecutive patients with a response were included in a randomized controlled therapywithdrawal trial in which they were assigned in a 1:1 ratio to either the therapy-maintenance or therapy-withdrawal group. The withdrawal group had the device turned off for 7 days; the maintenance group continued using the device. Polysomnography was done to measure the effects of withdrawal compared with continued use of therapy. Serious adverse events were those that led to death, lifethreatening illness, permanent impairment, or new or prolonged hospitalization with serious health impairment.Of the 126 participants, 83% were men; mean age was 54.5 years, and mean body mass index was 28.4 kg/m 2 . The mean AHI score on the initial screening polysomnography was 32.0 events per hour, and the mean ODI score was ...

Long-term 3-year improvements in objective respiratory and subjective quality-of-life outcome measures are maintained. Adverse events are uncommon. UAS is a successful and appropriate long-term treatment for individuals with moderate to severe OSA.

Comorbidity and pre-existing organ dysfunction are among several important prognostic factors for patients undergoing reirradiation. For those with both comorbidity and organ dysfunction, reirradiation largely serves as a palliative therapy.

RT for MCC was associated with improved LRC and survival. RT appeared to be beneficial regardless of margin status.