Programmed Death-Ligand 1 (PD-L1) as Immunotherapy Biomarker in Breast Cancer

Breast cancer constitutes the most common malignant neoplasm in women around the world. Approximately 12% of patients are diagnosed with metastatic stage, and between 5 and 30% of early or locally advanced BC patients will relapse, making it an incurable disease. PD-L1 ligation is an immune inhibitory molecule of the activation of T cells, playing a relevant role in numerous types of malignant tumors, including BC. The objective of the present review is to analyze the role of PD-L1 as a biomarker in the different BC subtypes, adding clinical trials with immune checkpoint inhibitors and their applicable results. Diverse trials using immunotherapy with anti-PD-1/PD-L1 in BC, as well as prospective or retrospective cohort studies about PD-L1 in BC, were included. Despite divergent results in the reviewed studies, PD-L1 seems to be correlated with worse prognosis in the hormone receptor positive subtype. Immune checkpoints inhibitors targeting the PD-1/PD-L1 axis have achieved great response rates in TNBC patients, especially in combination with chemotherapy, making immunotherapy a new treatment option in this scenario. However, the utility of PD-L1 as a predictive biomarker in the rest of BC subtypes remains unclear. In addition, predictive differences have been found in response to immunotherapy depending on the stage of the tumor disease. Therefore, a better understanding of tumor microenvironment, as well as identifying new potential biomarkers or combined index scores, is necessary in order to make a better selection of the subgroups of BC patients who will derive benefit from immune checkpoint inhibitors.

Update on systemic treatment in early triple negative breast cancer

Triple negative breast cancer (TNBC) is a heterogeneous disease representing about 15% of all breast cancers. TNBC are usually high-grade histological tumors, and are generally more aggressive and difficult to treat due to the lack of targeted therapies available, and chemotherapy remains the standard treatment. There is a close relationship between pathological complete response after chemotherapy treatment and higher rates of disease-free survival and overall survival. In this review of systemic treatment in early triple negative breast cancer, our purpose is to analyze and compare different therapies, as well as to highlight the novelties of treatment in this breast cancer subtype.

Veterinary education in the area of food safety (including animal health, food pathogens and surveillance of foodborne diseases)

The animal foodstuffs industry has changed in recent decades as a result of factors such as: human population growth and longer life expectancy, increasing urbanisation and migration, emerging zoonotic infectious diseases and foodborne diseases (FBDs), food security problems, technological advances in animal production systems, globalisation of trade and environmental changes. The Millennium Development Goals and the 'One Health' paradigm provide global guidelines on efficiently addressing the issues of consumer product safety, food security and risks associated with zoonoses. Professionals involved in the supply chain must therefore play an active role, based on knowledge and skills that meet current market requirements. Accordingly, it is necessary for the veterinary medicine curriculum, both undergraduate and postgraduate, to incorporate these skills. This article analyses the approach that veterinary education should adopt in relation to food safety, with an emphasis on animal health, food pathogens and FBD surveillance.

Effects of pregnancy on insulin receptor in liver, skeletal muscle and adipose tissue of rats

The mechanism responsible for insulin resistance during pregnancy remains unclear. Considerable evidence indicates that the insulin receptor plays an important role in insulin sensitivity. It seems possible that the hormonal milieu during gestation could have an effect on the insulin receptor. In the present study, measurements of tyrosine phosphorylation and protein content of the insulin receptor and expression of its gene in liver, skeletal muscle and adipose tissue indicate that during pregnancy significant changes occur in these parameters. We found that at the end of early gestation (day 10), muscle and adipose tissue are very sensitive to insulin action because the amount, phosphorylation and gene expression of insulin receptor is higher than in late gestation (days 15-20), while the tissue which is most sensitive to insulin action in late gestation is the liver. Our hypothesis is that these results are connected with changes in the concentrations of estradiol and progesterone observed during pregnancy. In conclusion, our previous and present findings seem to demonstrate that the different concentrations of gestational hormones play an important role in insulin sensitivity in this period and that each tissue responds in the most appropriate manner to guarantee the gestation in its entirety.

The effects of food restriction on maternal endocrine adaptations in pregnant rats

The aim of this study was to characterize hemodynamic, electrolytic and endocrine alterations produced by food restriction (50%) in pregnant rats for the purpose of evaluating the importance of these parameters on the plasma volume expansion and fetal growth. One hundred seventy six pregnant rats were divided into two groups, a control group (C) with an ad libitum diet and another with a restricted diet (U) (50% by weight of the diet of the control group). On days 5, 10, 15 and 20 of pregnancy, the weight of the mother, water intake, urine output, urine and plasma sodium concentration, plasma potassium concentration, blood pressure and heart rate, osmolality, plasma renin activity (PRA) and vasopressin were recorded. The number and weight of the fetuses were determined on days 15 and 20 of gestation. Food restriction results in inadequate weight gain in the mother and retardation of fetal growth. Water and sodium balance (p< or =0.001) were decreased in U group and basal PRA (p< or =0.001) was increased in U group. Food restriction did not significantly alter urine sodium excretion, plasma osmolality, plasma sodium and potassium values, blood pressure and basal vasopressin values. We conclude that the higher values of PRA, described in food restriction situations during pregnancy, seem to be caused by the adaptation to low sodium intake.

Role of 17-beta-estradiol and progesterone on glucose homeostasis: effects of food restriction (50%) in pregnant and non pregnant rats

The role of 17-beta-estradiol and progesterone on glucose homeostasis was examined in pregnant and non pregnant rats with or without food restriction (50%). Blood glucose and insulin levels were significantly decreased in food restricted pregnant (PM) compared with control pregnant (PC) and in food restricted non pregnant (M) compared with non pregnant control (C). The plasmatic level of progesterone was similar in PC and PM, while the plasmatic level of 17-beta-estradiol was significantly decreased in PM compared with PC at 15 and 20 days. In spite of food restriction, the changes in the insulin/glucose ratio throughout gestation were similar in PC and PM. A positive and significant relation between 17-beta-estradiol and the level of insulin at day 5 of gestation, and a negative and significant relation between the level of 17-beta-estradiol and level of insulin at day 15 of gestation were found in PC. A negative and significant relation between the levels of progesterone and the levels of insulin at day 5 of gestation, at day 10 this relation is positive and significative, and at day 15 a positive and significant relation exists between levels of 17-beta-estradiol and levels of insulin were found in PM. These results suggest that 17-beta-estradiol acts directly on beta-cells to control insulin secretion. Food restriction does not alter the changes in the sensitivity of tissues to the insulin action, and does modify the action of 17-beta-estradiol and progesterone on beta-cell.

Prothymosin alpha is phosphorylated by casein kinase-2

Prothymosin alpha (ProT alpha) is a 12.5 kDa acidic polypeptide that is considered to have a nuclear function related to cell proliferation. Inspection of its amino acid sequence revealed the presence of sequences that may serve as targets for phosphorylation by casein kinase-2 (CK-2). ProT alpha isolated from calf thymocytes was phosphorylated in vitro by CK-2. The phosphorylation sites are Ser and Thr residues located among the first 14 amino acid residues in the ProT alpha sequence. Another site that is theoretically suitable for phosphorylation by CK-2, at the C-terminus of the polypeptide, is not, in fact, phosphorylated. Thymosin alpha 1 (T alpha 1), a peptide whose sequence corresponds to the first 28 amino acids of ProT alpha, is also phosphorylated by CK-2 at the same phosphorylation sites as ProT alpha. In cultured splenic lymphocytes ProT alpha was phosphorylated at Thr residues located at positions 7, 12 and/or 13. Based on these observations we conclude that CK-2, or another cellular kinase with similar sequence specificity, is responsible for phosphorylation of ProT alpha in vivo.