Commensal Cutibacterium acnes induce epidermal lipid synthesis important for skin barrier function.

Lipid synthesis is necessary for formation of epithelial barriers and homeostasis with external microbes. An analysis of the response of human keratinocytes to several different commensal bacteria on the skin revealed that Cutibacterium acnes induced a large increase in essential lipids including triglycerides, ceramides, cholesterol, and free fatty acids. A similar response occurred in mouse epidermis and in human skin affected with acne. Further analysis showed that this increase in lipids was mediated by short-chain fatty acids produced by Cutibacterium acnes and was dependent on increased expression of several lipid synthesis genes including glycerol-3-phosphate-acyltransferase-3. Inhibition or RNA silencing of peroxisome proliferator-activated receptor-α (PPARα), but not PPARß and PPARγ, blocked this response. The increase in keratinocyte lipid content improved innate barrier functions including antimicrobial activity, paracellular diffusion, and transepidermal water loss. These results reveal that metabolites from a common commensal bacterium have a previously unappreciated influence on the composition of epidermal lipids.

Using feasibility dose-volume histograms to reduce intercampus plan quality variability for head-and-neck cancer.

The purpose of this work is to objectively assess variability of intercampus plan quality for head-and-neck (HN) cancer and to test utility of a priori feasibility dose-volume histograms (FDVHs) as planning dose goals. In this study, 109 plans treated from 2017 to 2019 were selected, with 52 from the main campus and 57 from various regional centers. For each patient, the planning computed tomography images and contours were imported into a commercial program to generate FDVHs with a feasibility value (f-value) ranging from 0.0 to 0.5. For 10 selected organs-at-risk (OARs), we used the Dice similarity coefficient (DSC) to quantify the overlaps between FDVH and clinically achieved DVH of each OAR and determined the f-value associated with the maximum DSC (labeled as f-max). Subsequently, 10 HN plans from the regional centers were replanned with planning dose goals guided by FDVHs. The clinical and feasibility-guided auto-planning (FgAP) plans were evaluated using our institutional criteria. Among plans from the main campus and regional centers, the median f-max values were statistically significantly different (p < 0.05) for all OARs except for the left parotid (p = 0.622), oral cavity (p = 0.057), and mandible (p = 0.237). For the 10 FgAP plans, the median values of f-max were 0.21, compared to 0.37 from the clinical plans. With comparable dose coverage to the tumor volumes, the significant differences (p < 0.05) in the median f-max and corresponding dose reduction (shown in parenthesis) for the spinal cord, larynx, supraglottis, trachea, and esophagus were 0.27 (8.5 Gy), 0.3 (7.6 Gy), 0.19 (5.9 Gy), 0.19 (8.9 Gy), and 0.12 (4.0 Gy), respectively. In conclusion, the FDVH prediction is an objective quality assurance tool to evaluate the intercampus plan variability. This tool can also provide guideline in planning dose goals to further improve plan quality.

FGF1 and insulin control lipolysis by convergent pathways.

Inexorable increases in insulin resistance, lipolysis, and hepatic glucose production (HGP) are hallmarks of type 2 diabetes. Previously, we showed that peripheral delivery of exogenous fibroblast growth factor 1 (FGF1) has robust anti-diabetic effects mediated by the adipose FGF receptor (FGFR) 1. However, its mechanism of action is not known. Here, we report that FGF1 acutely lowers HGP by suppressing adipose lipolysis. On a molecular level, FGF1 inhibits the cAMP-protein kinase A axis by activating phosphodiesterase 4D (PDE4D), which separates it mechanistically from the inhibitory actions of insulin via PDE3B. We identify Ser44 as an FGF1-induced regulatory phosphorylation site in PDE4D that is modulated by the feed-fast cycle. These findings establish the FGF1/PDE4 pathway as an alternate regulator of the adipose-HGP axis and identify FGF1 as an unrecognized regulator of fatty acid homeostasis.

Evaluation of Automated Treatment Planning and Organ Dose Prediction for Lung Stereotactic Body Radiotherapy.

PURPOSES: To evaluate whether the auto-planning (AP) module can achieve clinically acceptable treatment plans for lung stereotactic body radiotherapy (SBRT) and to evaluate the effectiveness of a dose prediction model. METHODS: Twenty lung SBRT cases planned manually with 50 Gy in five fractions were replanned using the Pinnacle (Philips Radiation Oncology Systems, Fitchburg, WI) AP module according to the dose constraint tables from the Radiation Therapy Oncology Group (RTOG) 0813 protocol. Doses to the organs at risk (OAR) were compared between the manual and AP plans. Using a dose prediction model from a commercial product, PlanIQ (Sun Nuclear Corporation, Melbourne, FL), we also compared OAR doses from AP plans with predicted doses. RESULTS: All manual and AP plans achieved clinically required dose coverage to the target volumes. The AP plans achieved equal or better OAR sparing when compared to the manual plans, most noticeable in the maximum doses of the spinal cord, ipsilateral brachial plexus, esophagus, and trachea. Predicted doses to the heart, esophagus, and trachea were highly correlated with the doses of these OARs from the AP plans with the highest correlation coefficient of 0.911, 0.823, and 0.803, respectively. CONCLUSION: Auto-planning for lung SBRT improved OAR sparing while keeping the same dose coverage to the tumor. The dose prediction model can provide useful planning dose guidance.

American Brachytherapy Society (ABS) consensus statement for soft-tissue sarcoma brachytherapy.

PURPOSE: Growing data supports the role of radiation therapy in the treatment of soft tissue sarcoma (STS). Brachytherapy has been used for decades in the management of STS and can be utilized as monotherapy or as a boost to external beam radiation. We present updated guidelines from the American Brachytherapy Society regarding the utilization of brachytherapy in the management of STS. METHODS AND MATERIALS: Members of the American Brachytherapy Society with expertise in STS and STS brachytherapy created an updated clinical practice guideline including step-by-step details for performing STS brachytherapy based on a literature review and clinical experience. RESULTS: Brachytherapy monotherapy should be considered for lower-recurrence risk patients or after a local recurrence following previous external beam radiation; a brachytherapy boost can be considered in higher-risk patents meeting implant criteria. Multiple dose/fractionation regimens are available, with determination based on tumor location and treatment intent. Techniques to limit wound complications are based on the type of wound closure; wound complication can be mitigated with a delay in the start of brachytherapy with immediate wound closure or by utilizing a staged reconstruction technique, which allows an earlier treatment start with a delayed wound closure. CONCLUSIONS: These updated guidelines provide clinicians with data on indications for STS brachytherapy as well as guidelines on how to perform and deliver high quality STS brachytherapy safely with minimal toxicity.

Serine restriction alters sphingolipid diversity to constrain tumour growth.

Serine, glycine and other nonessential amino acids are critical for tumour progression, and strategies to limit their availability are emerging as potential therapies for cancer1-3. However, the molecular mechanisms driving this response remain unclear and the effects on lipid metabolism are relatively unexplored. Serine palmitoyltransferase (SPT) catalyses the de novo biosynthesis of sphingolipids but also produces noncanonical 1-deoxysphingolipids when using alanine as a substrate4,5. Deoxysphingolipids accumulate in the context of mutations in SPTLC1 or SPTLC26,7-or in conditions of low serine availability8,9-to drive neuropathy, and deoxysphinganine has previously been investigated as an anti-cancer agent10. Here we exploit amino acid metabolism and the promiscuity of SPT to modulate the endogenous synthesis of toxic deoxysphingolipids and slow tumour progression. Anchorage-independent growth reprogrammes a metabolic network involving serine, alanine and pyruvate that drives the endogenous synthesis and accumulation of deoxysphingolipids. Targeting the mitochondrial pyruvate carrier promotes alanine oxidation to mitigate deoxysphingolipid synthesis and improve spheroid growth, similar to phenotypes observed with the direct inhibition of SPT or ceramide synthesis. Restriction of dietary serine and glycine potently induces the accumulation of deoxysphingolipids while decreasing tumour growth in xenograft models in mice. Pharmacological inhibition of SPT rescues xenograft growth in mice fed diets restricted in serine and glycine, and the reduction of circulating serine by inhibition of phosphoglycerate dehydrogenase (PHGDH) leads to the accumulation of deoxysphingolipids and mitigates tumour growth. The promiscuity of SPT therefore links serine and mitochondrial alanine metabolism to membrane lipid diversity, which further sensitizes tumours to metabolic stress.

The lipid elongation enzyme ELOVL2 is a molecular regulator of aging in the retina.

Methylation of the regulatory region of the elongation of very-long-chain fatty acids-like 2 (ELOVL2) gene, an enzyme involved in elongation of long-chain polyunsaturated fatty acids, is one of the most robust biomarkers of human age, but the critical question of whether ELOVL2 plays a functional role in molecular aging has not been resolved. Here, we report that Elovl2 regulates age-associated functional and anatomical aging in vivo, focusing on mouse retina, with direct relevance to age-related eye diseases. We show that an age-related decrease in Elovl2 expression is associated with increased DNA methylation of its promoter. Reversal of Elovl2 promoter hypermethylation in vivo through intravitreal injection of 5-Aza-2'-deoxycytidine (5-Aza-dc) leads to increased Elovl2 expression and rescue of age-related decline in visual function. Mice carrying a point mutation C234W that disrupts Elovl2-specific enzymatic activity show electrophysiological characteristics of premature visual decline, as well as early appearance of autofluorescent deposits, well-established markers of aging in the mouse retina. Finally, we find deposits underneath the retinal pigment epithelium in Elovl2 mutant mice, containing components found in human drusen, a pathologic hallmark of age related macular degeneration. These findings indicate that ELOVL2 activity regulates aging in mouse retina, provide a molecular link between polyunsaturated fatty acids elongation and visual function, and suggest novel therapeutic strategies for the treatment of age-related eye diseases.

Modern Approaches for Breast Brachytherapy.

Breast brachytherapy represents a radiation technique that can be utilized as both monotherapy and as a tumor bed boost following breast conserving surgery. As monotherapy, the rationale for brachytherapy is that the majority of residual disease and therefore recurrences occur in close proximity to the lumpectomy cavity; for boost treatment, brachytherapy represents a technique that provided a more conformal approach prior to 3D treatment planning, and more recently can be used in conjunction with oncoplastic surgery. Multiple guidelines are available to assist clinicians with patient selection for accelerated partial breast irradiation (APBI), and recent guidelines support brachytherapy as an appropriate technique to deliver APBI. Modern breast brachytherapy can be performed with interstitial or applicator-based brachytherapy with multilumen and strut devices offering the ability to provide greater skin, chest wall, and normal breast sparing than previous devices. Novel strategies are being evaluated, including high dose rate perioperative/intraoperative radiotherapy, permanent breast seed implants, and noninvasive breast brachytherapy. Additionally, studies are evaluating shorter courses of brachytherapy. Multiple Level I studies are now available supporting interstitial brachytherapy to deliver APBI while prospective data and the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 trial are available with applicator brachytherapy and provide standardized prescriptions, target volume definitions, and dosimetric goals.

Spine radiosurgery in adolescents and young adults: early outcomes and toxicity in patients with metastatic Ewing sarcoma and osteosarcoma.

OBJECTIVE: There are limited data on spine stereotactic radiosurgery (SRS) in treating adolescent and young adult (AYA) patients. SRS has the advantages of highly conformal radiation dose delivery in the upfront and retreatment settings, means for dose intensification, and administration over a limited number of sessions leading to a decreased treatment burden. In this study, the authors report the oncological and toxicity outcomes for AYA patients with metastatic sarcoma treated with spine radiosurgery and provide clinicians a guide for considerations in dose, volume, and fractionation. METHODS: An institutional review board-approved database of patients treated with SRS in the period from October 2014 through December 2018 was queried. AYA patients, defined by ages 15-29 years, who had been treated with SRS for spine metastases from Ewing sarcoma or osteosarcoma were included in this analysis. Patients with follow-ups shorter than 6 months after SRS were excluded. Local control, overall survival, and toxicity were reported. RESULTS: Seven patients with a total of 11 treated lesions were included in this study. Median patient age was 20.3 years (range 15.1-26.1 years). Three patients had Ewing sarcoma (6 lesions) and 4 patients had osteosarcoma (5 lesions). The median dose delivered was 35 Gy in 5 fractions (range 16-40 Gy, 1-5 fractions). The median follow-up was 11.1 months (range 6.8-26.0 months). Three local failures were observed within the follow-up period. No acute grade 3 or greater toxicity was observed. One patient developed late grade 3 toxicity consisting of radiation enteritis. This patient had previously received radiation to an overlapping volume with conventional fractionation. SRS re-irradiation for this patient was also performed concurrently with chemotherapy administration. No late grade 4 or higher toxicities were observed. No pain flare or vertebral compression fracture was observed. Three patients died within the follow-up period. CONCLUSIONS: SRS for spine metastases from Ewing sarcoma and osteosarcoma can be considered as a treatment option in AYA patients and is associated with acceptable toxicity rates. Further studies must be conducted to determine long-term local control and toxicity for this treatment modality.

Stereochemistry of Linoleic Acid Esters of Hydroxy Linoleic Acids.

The syntheses of linoleic acid esters of hydroxy linoleic acids (LAHLAs) present in oat oil and human serum have been achieved, providing access to material for testing and the determination of the stereochemistry of the natural compounds. While 9- and 13-LAHLAs were found to be a mixture of enantiomers 15-LAHLA is generated in a single optical form in oat oil. The stereochemistry of 15-LAHLA in oat oil was found to be opposite to that reported for digalactosyldiacylglycerol that possesses an embedded 15-LAHLA.

Linoleic acid esters of hydroxy linoleic acids are anti-inflammatory lipids found in plants and mammals.

Fatty acid esters of hydroxy fatty acids (FAHFAs) are a recently discovered class of biologically active lipids. Here we identify the linoleic acid ester of 13-hydroxy linoleic acid (13-LAHLA) as an anti-inflammatory lipid. An oat oil fraction and FAHFA-enriched extract from this fraction showed anti-inflammatory activity in a lipopolysaccharide-induced cytokine secretion assay. Structural studies identified three LAHLA isomers (15-, 13-, and 9-LAHLA) as being the most abundant FAHFAs in the oat oil fraction. Of these LAHLAs, 13-LAHLA is the most abundant LAHLA isomer in human serum after ingestion of liposomes made of fractionated oat oil, and it is also the most abundant endogenous LAHLA in mouse and human adipose tissue. As a result, we chemically synthesized 13-LAHLA for biological assays. 13-LAHLA suppresses lipopolysaccharide-stimulated secretion of cytokines and expression of pro-inflammatory genes. These studies identify LAHLAs as an evolutionarily conserved lipid with anti-inflammatory activity in mammalian cells.

The American Brachytherapy Society consensus statement on intraoperative radiation therapy.

PURPOSE: Although radiation therapy has traditionally been delivered with external beam or brachytherapy, intraoperative radiation therapy (IORT) represents an alternative that may shorten the course of therapy, reduce toxicities, and improve patient satisfaction while potentially lowering the cost of care. At this time, there are limited evidence-based guidelines to assist clinicians with patient selection for IORT. As such, the American Brachytherapy Society presents a consensus statement on the use of IORT. METHODS: Physicians and physicists with expertise in intraoperative radiation created a site-directed guideline for appropriate patient selection and utilization of IORT. RESULTS: Several IORT techniques exist including radionuclide-based high-dose-rate, low-dose-rate, electron, and low-energy electronic. In breast cancer, IORT as monotherapy should only be used on prospective studies. IORT can be considered in the treatment of sarcomas with close/positive margins or recurrent sarcomas. IORT can be considered in conjunction with external beam radiotherapy for retroperitoneal sarcomas. IORT can be considered for colorectal malignancies with concern for positive margins and in the setting of recurrent gynecologic cancers. For thoracic, head and neck, and central nervous system malignancies, utilization of IORT should be evaluated on a case-by-case basis. CONCLUSIONS: The present guidelines provide clinicians with a summary of current data regarding IORT by treatment site and guidelines for the appropriate patient selection and safe utilization of the technique. High-dose-rate, low-dose-rate brachytherapy methods are appropriate when IORT is to be delivered as are electron and low-energy based on the clinical scenario.

Author Correction: Blocking Zika virus vertical transmission.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Principles and practice of high-dose rate penile brachytherapy: Planning and delivery techniques.

PURPOSE: To allow for organ preservation, high-dose rate (HDR) brachytherapy may be used in the treatment of localized penile cancer. Penile cancer is a rare malignancy that accounts for <1% of cancers in men in the United States. The standard treatment for localized disease is partial amputation of the penis. However, patients with T1b or T2 disease <4 cm in maximum dimension and confined to the glans penis may be treated with brachytherapy as an organ-sparing approach. Previous works have described the technique involved for low-dose rate brachytherapy; however, we detail the techniques involved with HDR brachytherapy. METHODS AND MATERIALS: Circumcision should precede brachytherapy. Interstitial brachytherapy needles are placed in the operating room under general anesthesia with the goal to allow for appropriate target coverage. Target definition is done via computed tomography-based simulation and planning. Radiation is delivered using a prescription dose of 3840 cGy in 12 fractions twice daily over a course of 6 days. RESULTS: Acute toxicities peak upon completion of the radiation therapy and may include dermatitis, sterile urethritis, and adhesions in the urethra. These toxicities are reversible and generally take 2 to 3 months to heal. The two most common and significant late complications of radiation therapy for penile cancer are soft tissue necrosis and meatal stenosis. An increased risk of necrosis has been reported with T3 tumors and higher-volume implants (>30 cm3). Erectile function is generally maintained because the erectile tissues including the penile shaft and corpora have not been irradiated. CONCLUSIONS: Organ preservation is feasible using HDR brachytherapy with favorable acute and late toxicities.

Faster Protocol for Endogenous Fatty Acid Esters of Hydroxy Fatty Acid (FAHFA) Measurements.

Fatty acid esters of hydroxy fatty acids (FAHFAs) are a recently discovered class of endogenous lipids with antidiabetic and anti-inflammatory activities. Interest in these lipids is due to their unique biological activites and the observation that insulin-resistant people have lower palmitic acid esters of hydroxystearic acid (PAHSA) levels, suggesting that a FAHFA deficiency may contribute to metabolic disease. Rigorous testing of this hypothesis will require the measurement of many clinical samples; however, current analytical workflows are too slow to enable samples to be analyzed quickly. Here we describe the development of a significantly faster workflow to measure FAHFAs that optimizes the fractionation and chromatography of these lipids. We can measure FAHFAs in 30 min with this new protocol versus 90 min using the older protocol with comparable performance in regioisomer detection and quantitation. We also discovered through this optimization that oleic acid esters of hydroxystearic acids (OAHSAs), another family of FAHFAs, have a much lower background signal than PAHSAs, which makes them easier to measure. Our faster workflow was able to quantify changes in PAHSAs and OAHSAs in mouse tissues and human plasma, highlighting the potential of this protocol for basic and clinical applications.

Palmitic Acid Hydroxystearic Acids Activate GPR40, Which Is Involved in Their Beneficial Effects on Glucose Homeostasis.

Palmitic acid hydroxystearic acids (PAHSAs) are endogenous lipids with anti-diabetic and anti-inflammatory effects. PAHSA levels are reduced in serum and adipose tissue of insulin-resistant people and high-fat diet (HFD)-fed mice. Here, we investigated whether chronic PAHSA treatment enhances insulin sensitivity and which receptors mediate PAHSA effects. Chronic PAHSA administration in chow- and HFD-fed mice raises serum and tissue PAHSA levels ∼1.4- to 3-fold. This improves insulin sensitivity and glucose tolerance without altering body weight. PAHSA administration in chow-fed, but not HFD-fed, mice augments insulin and glucagon-like peptide (GLP-1) secretion. PAHSAs are selective agonists for GPR40, increasing Ca+2 flux, but not intracellular cyclic AMP. Blocking GPR40 reverses improvements in glucose tolerance and insulin sensitivity in PAHSA-treated chow- and HFD-fed mice and directly inhibits PAHSA augmentation of glucose-stimulated insulin secretion in human islets. In contrast, GLP-1 receptor blockade in PAHSA-treated chow-fed mice reduces PAHSA effects on glucose tolerance, but not on insulin sensitivity. Thus, PAHSAs activate GPR40, which is involved in their beneficial metabolic effects.

Pharmacological activation of REV-ERBs is lethal in cancer and oncogene-induced senescence.

The circadian clock imposes daily rhythms in cell proliferation, metabolism, inflammation and DNA damage response. Perturbations of these processes are hallmarks of cancer and chronic circadian rhythm disruption predisposes individuals to tumour development. This raises the hypothesis that pharmacological modulation of the circadian machinery may be an effective therapeutic strategy for combating cancer. REV-ERBs, the nuclear hormone receptors REV-ERBα (also known as NR1D1) and REV-ERBß (also known as NR1D2), are essential components of the circadian clock. Here we show that two agonists of REV-ERBs-SR9009 and SR9011-are specifically lethal to cancer cells and oncogene-induced senescent cells, including melanocytic naevi, and have no effect on the viability of normal cells or tissues. The anticancer activity of SR9009 and SR9011 affects a number of oncogenic drivers (such as HRAS, BRAF, PIK3CA and others) and persists in the absence of p53 and under hypoxic conditions. The regulation of autophagy and de novo lipogenesis by SR9009 and SR9011 has a critical role in evoking an apoptotic response in malignant cells. Notably, the selective anticancer properties of these REV-ERB agonists impair glioblastoma growth in vivo and improve survival without causing overt toxicity in mice. These results indicate that pharmacological modulation of circadian regulators is an effective antitumour strategy, identifying a class of anticancer agents with a wide therapeutic window. We propose that REV-ERB agonists are inhibitors of autophagy and de novo lipogenesis, with selective activity towards malignant and benign neoplasms.

Blocking Zika virus vertical transmission.

The outbreak of the Zika virus (ZIKV) has been associated with increased incidence of congenital malformations. Although recent efforts have focused on vaccine development, treatments for infected individuals are needed urgently. Sofosbuvir (SOF), an FDA-approved nucleotide analog inhibitor of the Hepatitis C (HCV) RNA-dependent RNA polymerase (RdRp) was recently shown to be protective against ZIKV both in vitro and in vivo. Here, we show that SOF protected human neural progenitor cells (NPC) and 3D neurospheres from ZIKV infection-mediated cell death and importantly restored the antiviral immune response in NPCs. In vivo, SOF treatment post-infection (p.i.) decreased viral burden in an immunodeficient mouse model. Finally, we show for the first time that acute SOF treatment of pregnant dams p.i. was well-tolerated and prevented vertical transmission of the virus to the fetus. Taken together, our data confirmed SOF-mediated sparing of human neural cell types from ZIKV-mediated cell death in vitro and reduced viral burden in vivo in animal models of chronic infection and vertical transmission, strengthening the growing body of evidence for SOF anti-ZIKV activity.

Stapled peptide inhibitors of RAB25 target context-specific phenotypes in cancer.

Recent evidence has established a role for the small GTPase RAB25, as well as related effector proteins, in enacting both pro-oncogenic and anti-oncogenic phenotypes in specific cellular contexts. Here we report the development of all-hydrocarbon stabilized peptides derived from the RAB-binding FIP-family of proteins to target RAB25. Relative to unmodified peptides, optimized stapled peptides exhibit increased structural stability, binding affinity, cell permeability, and inhibition of RAB25:FIP complex formation. Treatment of cancer cell lines in which RAB25 is pro-oncogenic with an optimized stapled peptide, RFP14, inhibits migration, and proliferation in a RAB25-dependent manner. In contrast, RFP14 treatment augments these phenotypes in breast cancer cells in which RAB25 is tumor suppressive. Transcriptional profiling identified significantly altered transcripts in response to RAB25 expression, and treatment with RFP14 opposes this expression profile. These data validate the first cell-active chemical probes targeting RAB-family proteins and support the role of RAB25 in regulating context-specific oncogenic phenotypes.The Ras-family small GTPase RAB25 can exert both pro- and anti-oncogenic functions. Here, the authors develop all-hydrocarbon stabilized peptides targeting RAB25 and influencing the context-specificity phenotypes in cancer cell lines.