No abstract

PDAC is one of the most heterogeneous cancers with low chemotherapeutic sensitivity due to a dense stroma, a weak vasculature and significant biological aggressivity. In cancer, suppressive immune checkpoints are often hyper-activated to ensure an effective evasion of tumor cells from immune surveillance. These immune checkpoints include in part, the B7/butyrophilin-like receptors such as butyrophilin sub-family 3A/CD277 receptors (BTN3A), the B and T lymphocyte attenuator (BTLA) belonging to the B7-like receptors and the programmed death protein (PD-1) with its ligand PD-L1. We evaluated the plasma level of these markers in 32 PDAC patients (learning cohort) by ad hoc developed ELISA's and showed that there are highly correlated. We used ROC curves and univariate analysis to characterize their prognostic relevance in these patients and showed that their plasma level can serve as survival predictor. Plasma level thresholds that correlate with less than six months survival were established for sPD-1 (>8.6 ng/ml), sPD-L1 (>0.36 ng/ml), sBTLA (>1.91 ng/ml), sBTN3A1 (>6.98 ng/ml) and pan-sBTN3A (>6.92 ng/ml). These thresholds were applied in independent validation cohort composed by 27 new samples and could efficiently discriminate short versus long PDAC survivors. Our study reveals that monitoring the concentration of soluble forms of inhibitory immune checkpoints in plasma can help predict survival in PDAC patients and therefore improve their treatments.

The angiopoietin-like 4 (ANGPTL4) protein belongs to a superfamily of secreted proteins structurally related to factors modulating angiogenesis known as angiopoietins. At first, ANGPTL4 has been identified as an adipokine exclusively involved in lipid metabolism, because of its prevalent expression in liver and adipose tissue. This protein regulates lipid metabolism by inhibiting lipoprotein lipase (LPL) activity and stimulating lipolysis of white adipose tissue (WAT), resulting in increased levels of plasma triglycerides (TG) and fatty acids. Subsequently, ANGPTL4 has been shown to be involved in several nonmetabolic and metabolic conditions, both physiological and pathological, including angiogenesis and vascular permeability, cell differentiation, tumorigenesis, glucose homoeostasis, lipid metabolism, energy homeostasis, wound healing, inflammation, and redox regulation. The transcriptional regulation of ANGPTL4 can be modulated by several transcription factors, including PPARα, PPARβ/δ, PPARγ, and HIF-1α, and nutritional and hormonal conditions. Several studies showed that high levels of ANGPTL4 are associated with poor prognosis in patients with various solid tumors, suggesting an important role in cancer onset and progression, metastasis, and anoikis resistance. Here, we have discussed the potential role of ANGPTL4 in mediating the cross talk between metabolic syndromes, such as diabetes and obesity, and cancer through regulation of its expression by PPARs.

No abstract

miRNAs have the potential for better understanding of tumor biology, but could also provide clinical advancement in management and therapy of various malignancies. The possibility of miRNA detection in peripheral blood would allow an eager expansion of their application in various clinical settings for cancer. The applicability of miRNA expression profiles still needs to be defined.