Glucocorticoids and natural killer cells: A suppressive relationship.

Glucocorticoids exert their pharmacological actions by mimicking and amplifying the function of the endogenous glucocorticoid system's canonical physiological stress response. They affect the immune system at the levels of inflammation and adaptive and innate immunity. These effects are the basis for therapeutic use of glucocorticoids.

Glucocorticoid and PD-1 Cross-Talk: Does the Immune System Become Confused?

Programmed cell death protein 1 (PD-1) and its ligands, PD-L1/2, control T cell activation and tolerance. While PD-1 expression is induced upon T cell receptor (TCR) activation or cytokine signaling, PD-L1 is expressed on B cells, antigen presenting cells, and on non-immune tissues, including cancer cells. Importantly, PD-L1 binding inhibits T cell activation.

Bcl-xL overexpression decreases GILZ levels and inhibits glucocorticoid-induced activation of caspase-8 and caspase-3 in mouse thymocytes.

Glucocorticoids promote thymocyte apoptosis and modulate transcription of numerous regulators of thymic apoptosis. Among these, glucocorticoid-induced leucine zipper (GILZ) is strongly upregulated in the thymus. We have previously demonstrated that GILZ decreases Bcl-xL expression, activates caspase-8 and caspase-3, and augments apoptosis in mice thymocytes.

L-GILZ binds and inhibits nuclear factor κB nuclear translocation in undifferentiated thyroid cancer cells.

Proto-oncogene mutations and abnormal activation of mitogen-activated protein kinase (MAPK) signalling are recurrently found in thyroid cancers. Some thyroid neoplasms respond to drugs that inhibit MAPK pathway activation. Previously, we showed that pharmacological inhibition of MAPK in thyroid cancer cells inhibits cell proliferation and upregulates L-GILZ (long glucocorticoid-induced leucine zipper), a protein with anti-oncogenic and antiproliferative activity, and that L-GILZ is partially responsible for the antiproliferative activity of MAPK inhibitors.

Fusarubin and Anhydrofusarubin Isolated from A Species Inhibit Cell Growth in Human Cancer Cell Lines.

species are endophytic fungi that grow on organic matter and are considered food contaminants. The anti-microbial and anti-tumor naphthoquinones fusarubin (FUS) and anhydrofusarubin (AFU) were isolated using column chromatography from a species residing inside leaves. The impact of FUS and AFU on cell growth was assessed in acute myeloid leukemia (OCI-AML3) and other hematologic tumor cell lines (HL-60, U937, and Jurkat).