Acquired dysfunction of CFTR underlies cystic fibrosis-like disease of the canine gallbladder.

Mucocele formation in dogs is a unique and enigmatic muco-obstructive disease of the gallbladder caused by amassment of abnormal mucus that bears striking pathological similarity to cystic fibrosis. We investigated the role of CFTR in the pathogenesis of this disease. The location and frequency of disease-associated variants in the coding region of CFTR was compared using whole genome sequence data from 2,642 dogs representing breeds at low-risk, high-risk, or with confirmed disease. Expression, localization, and ion transport activity of CFTR was quantified in control and mucocele gallbladders by NanoString, Western blotting, immunofluorescence imaging, and studies in Ussing chambers. Our results establish significant loss of CFTR-dependent anion secretion by mucocele gallbladder mucosa. A significantly lower quantity of CFTR protein was demonstrated relative to E-cadherin in mucocele compared to control gallbladder mucosa. Immunofluorescence identified CFTR along the apical membrane of epithelial cells in control gallbladders but not in mucocele gallbladder epithelium. Decreases in mRNA copy number for CFTR was accompanied by decreases in mRNA for the Cl-/HCO3- exchanger SLC26A3, K+ channels (KCNQ1, KCNN4), and vasoactive intestinal polypeptide receptor (VIPR1) which suggest a driving force for change in secretory function of gallbladder epithelial cells in the pathogenesis of mucocele formation. There were no significant differences in CFTR gene variant frequency, type, or predicted impact comparing low risk, high risk, and definitively diagnosed groups of dogs. This study describes a unique, naturally occurring muco-obstructive disease of the canine gallbladder, with uncanny similarity to cystic fibrosis, and driven by underlying failure of CFTR function.

Antitumour effect of the mitochondrial complex III inhibitor Atovaquone in combination with anti-PD-L1 therapy in mouse cancer models.

Immune checkpoint blockade (ICB) provides effective and durable responses for several tumour types by unleashing an immune response directed against cancer cells. However, a substantial number of patients treated with ICB develop relapse or do not respond, which has been partly attributed to the immune-suppressive effect of tumour hypoxia. We have previously demonstrated that the mitochondrial complex III inhibitor atovaquone alleviates tumour hypoxia both in human xenografts and in cancer patients by decreasing oxygen consumption and consequently increasing oxygen availability in the tumour. Here, we show that atovaquone alleviates hypoxia and synergises with the ICB antibody anti-PD-L1, significantly improving the rates of tumour eradication in the syngeneic CT26 model of colorectal cancer. The synergistic effect between atovaquone and anti-PD-L1 relied on CD8+ T cells, resulted in the establishment of a tumour-specific memory immune response, and was not associated with any toxicity. We also tested atovaquone in combination with anti-PD-L1 in the LLC (lung) and MC38 (colorectal) cancer syngeneic models but, despite causing a considerable reduction in tumour hypoxia, atovaquone did not add any therapeutic benefit to ICB in these models. These results suggest that atovaquone has the potential to improve the outcomes of patients treated with ICB, but predictive biomarkers are required to identify individuals likely to benefit from this intervention.

Small-Molecule Polθ Inhibitors Provide Safe and Effective Tumor Radiosensitization in Preclinical Models.

PURPOSE: DNA polymerase theta (Polθ, encoded by the POLQ gene) is a DNA repair enzyme critical for microhomology mediated end joining (MMEJ). Polθ has limited expression in normal tissues but is frequently overexpressed in cancer cells and, therefore, represents an ideal target for tumor-specific radiosensitization. In this study we evaluate whether targeting Polθ with novel small-molecule inhibitors is a feasible strategy to improve the efficacy of radiotherapy. EXPERIMENTAL DESIGN: We characterized the response to Polθ inhibition in combination with ionizing radiation in different cancer cell models in vitro and in vivo. RESULTS: Here, we show that ART558 and ART899, two novel and specific allosteric inhibitors of the Polθ DNA polymerase domain, potently radiosensitize tumor cells, particularly when combined with fractionated radiation. Importantly, noncancerous cells were not radiosensitized by Polθ inhibition. Mechanistically, we show that the radiosensitization caused by Polθ inhibition is most effective in replicating cells and is due to impaired DNA damage repair. We also show that radiosensitization is still effective under hypoxia, suggesting that these inhibitors may help overcome hypoxia-induced radioresistance. In addition, we describe for the first time ART899 and characterize it as a potent and specific Polθ inhibitor with improved metabolic stability. In vivo, the combination of Polθ inhibition using ART899 with fractionated radiation is well tolerated and results in a significant reduction in tumor growth compared with radiation alone. CONCLUSIONS: These results pave the way for future clinical trials of Polθ inhibitors in combination with radiotherapy.

Personalized Radiation Attenuating Materials for Gastrointestinal Mucosal Protection.

Cancer patients undergoing therapeutic radiation routinely develop injury of the adjacent gastrointestinal (GI) tract mucosa due to treatment. To reduce radiation dose to critical GI structures including the rectum and oral mucosa, 3D-printed GI radioprotective devices composed of high-Z materials are generated from patient CT scans. In a radiation proctitis rat model, a significant reduction in crypt injury is demonstrated with the device compared to without (p < 0.0087). Optimal device placement for radiation attenuation is further confirmed in a swine model. Dosimetric modeling in oral cavity cancer patients demonstrates a 30% radiation dose reduction to the normal buccal mucosa and a 15.2% dose reduction in the rectum for prostate cancer patients with the radioprotectant material in place compared to without. Finally, it is found that the rectal radioprotectant device is more cost-effective compared to a hydrogel rectal spacer. Taken together, these data suggest that personalized radioprotectant devices may be used to reduce GI tissue injury in cancer patients undergoing therapeutic radiation.

Características sócio-demográficas e reprodutivas de adolescentes atendidas no pós-parto no Instituto da Criança da Universidade de São Paulo / Socio-demographic and reproductive characteristics of adolescent mothers who attended an inpatient clinic linked to the adolescent unit of public hospital

Tendo em vista os problemas inerentes à gravidez na adolescência e a importância de direcionar ações de sáude para essa população a Unidade de Adolescentes do Instituto da Criança do Hospital das Clínicas da USP estendeu o atendimento, oferecendo atenção integral para mães adolescentes e seus filhos que freqüentaram o pré-natal na Disciplina de Obstetrícia da FMUSP. Este estudo visou identificar algumas características do modo de vida das mães adolescentes que freqüentam esse serviço. A população amostral foi constituída pelas 81 jovens que freqüentavam o ambulatório no período de estudo. Verificou-se que 76,5 por cento delas não planejaram a gestação. Mesmo assim, com o apoio familiar e da instituição, planejavam mais filhos em data futura. A maioria delas convivia com o companheiro que, algumas vezes, assumiu também a chefia da família da adolescente. Grande parte delas, 54,3 por cento abandonou os estudos e, das 59 mães que trabalhavam, 38 deixaram de fazê-lo. As atividades de lazer foram modificadas e cerca de metade das jovens deixou de participar de qualquer atividade de lazer. O estudo permite ressaltar as repercussões da maternidade na vida das jovens e evidencia a importância do pré-natal e de serviços que proporcionem atendimento pós-parto, enfocando a saúde de uma forma global, beneficiando as adolescentes e seus filhos.

Caracterizaçäo nutricional de um populaçäo de mäes adolescentes / Nutritional status characterization of adolescent mothers' population

Objetivo: Caracterizar o estado nutricional e identificar alguns aspectos econômicos, sociais, alimentares e biológicos de uma populaçäo de mäes que tiveram seus filhos na adolescência. Metodologia: A populaçäo amostral foi constituída pelas 81 mäes, que freqüentaram ambulatório vinculado à Unidade de Adolescentes do ICr-HCFMUSP, no período de fevereiro a julho de 1999. Foram levantadas informaçöes sobre características pessoais, lazer, ingestäo alimentar e estado nutricional. Analisou-se a adequaçäo do consumo de energia, cálcio, ferro e vitamina A. O estado nutricional foi avaliado segundo indicadores de altura para a idade (A/I), peso para a idade (P/I) e índice de massa corporal (IMC). Resultados: 76,5 por cento näo planejaram a gravidez, 39,5 por cento näo concluiram o 1§ grau, 54,3 por cento abandonaram os estudos e 49,0 por cento näo trabalhavam. As jovens relataram diminuiçäo na participaçäo em atividades de lazer, durante e após a gravidez. O consumo energético e dos demais nutrientes mostrou-se abaixo do recomendado. Cerca de 6 por cento da populaçäo apresentou baixa estatura e 13 por cento baixo peso. Pelo IMC, 21 por cento encontrava-se com sobrepeso näo sendo registrados casos de desnutriçäo. Conclusöes: O estudo aponta para as repercussöes da maternidade na vida destas jovens e para inadequaçöes importantes do hábito alimentar. Evidencia a importância do pré-natal e de serviços que proporcionem atendimento após o parto, enfocando de forma eficaz a alimentaçäo e a saúde de uma forma global, para beneficiar estas jovens e seus filhos.