Expression of PIM kinases in Reed-Sternberg cells fosters immune privilege and tumor cell survival in Hodgkin lymphoma.

Reed-Sternberg (RS) cells of classical Hodgkin lymphoma (cHL) express multiple immunoregulatory proteins that shape the cHL microenvironment and allow tumor cells to evade immune surveillance. Expression of certain immunoregulatory proteins is modulated by prosurvival transcription factors, such as NFκB and STATs. Because these factors also induce expression of the oncogenic PIM1/2/3 serine/threonine kinases, and as PIMs modulate transcriptional activity of NFκB and STATs, we hypothesized that these kinases support RS cell survival and foster their immune privilege. Here, we investigated PIM1/2/3 expression in cHL and assessed their role in developing RS cell immune privilege and survival. PIM1/2/3 were ubiquitously expressed in primary and cultured RS cells, and their expression was driven by JAK-STAT and NFκB activity. Genetic or chemical PIM inhibition with a newly developed pan-PIM inhibitor, SEL24-B489, induced RS cell apoptosis. PIM inhibition decreased cap-dependent protein translation, blocked JAK-STAT signaling, and markedly attenuated NFκB-dependent gene expression. In a cHL xenograft model, SEL24-B489 delayed tumor growth by 95.8% (P = .0002). Furthermore, SEL24-B489 decreased the expression of multiple molecules engaged in developing the immunosuppressive microenvironment, including galectin-1 and PD-L1/2. In coculture experiments, T cells incubated with SEL24-B489-treated RS cells exhibited higher expression of activation markers than T cells coincubated with control RS cells. Taken together, our data indicate that PIM kinases in cHL exhibit pleiotropic effects, orchestrating tumor immune escape and supporting RS cell survival. Inhibition of PIM kinases decreases RS cell viability and disrupts signaling circuits that link these cells with their niches. Thus, PIM kinases are promising therapeutic targets in cHL.

[The effects of di-n-butyl phthalate on the somatic cells of laboratory mice]. / Wplyw ftalanu di-n-butylu (DBP) na komórki somatyczne myszy laboratoryjnych.

Phthalates are widely used as a plasticizers in manufacture of synthetic materials and as solvents in sanitary products, cosmetics and pharmaceutical products. Dibutylphthalate (DBP) is used as a plasticizers and as a textile lubricating agent and as solvent in printing ink. The study aimed the evaluation of the magnitude of DNA damage in liver and bone marrow cells and estimation of dibutyl phthalate (DBP) concentration in peripheral blood following prolonged exposure to DBP. Experiments were conducted an the Pzh:Sfis male mice. Animals were exposed 8 weeks, 3 days per week per os to DBP suspension in oil in doses of 500 mg/kg bw (1/16 LD50) and 2000 mg/kg bw (1/4 LD50). Following groups of mice were sacrificed 4 and 8 weeks after the start of exposure and 4 weeks after the end of exposure. Decreased body weight of mice and statistically significant decreased liver and relative liver weights were observed following 8-weeks exposure to 2000 mg/kg bw DBP. In the same time higher however not statistically significant level of DNA damage measured by Comet assay in liver cells were noted. DBP did not induce enhanced frequency of DNA damage in bone marrow cells. Following 8-weeks exposure to the dose of 2000 mg/kg bw DBP the increased level of DBP in peripheral blood was observed. Enhanced levels of DBP were still noted 4 weeks after the termination of exposure. Results confirmed that DBP acts as a weak mutagen for DNA of somatic cells. However, following prolonged exposure this compound seems to undergo slower metabolism and was reaching temporarily higher levels in peripheral blood.

Radiation-induced micronucleus frequencies in female peripheral blood lymphocytes collected during the first and second half of the menstrual cycle.

Biological dosimetry relies on the assessment of dose in peripheral blood lymphocytes (PBL) of a victim. Variability in the individual radiosensitivity of PBL has an impact on the precision of dose estimate and radiation-induced micronuclei show a strong individual variability. A factor which can influence the radiosensitivity of PBL is the hormonal status of female donors, which shows a regular pattern during the menstrual cycle. The aim of the present investigation was to verify whether the position within the menstrual cycle has an impact on the level of micronuclei in PBL. Blood was collected from 19 donors during the first and second half of the menstrual cycle and exposed to 2 Gy. Although statistically significant differences between the MN frequencies in PBL collected during the different time points were observed in the case of some donors, no reproducible trend that could find application in biological dosimetry could be detected.