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.

Two generation reproductive and developmental toxicity following subchronic exposure of pubescent male mice to di(2-ethylhexyl)phthalate.

Di-(2-ethylhexyl)phthalate (DEHP) is widely present in the human environment. The study aimed at the investigation of potential genotoxic effects induced by subchronic exposure to DEHP in germ cells of male mice in the first period of puberty, and to check if the transmission of mutation to the next generation via the sperm is possible. 8-weeks exposure to 2,000 mg/kg and 8,000 mg/kg of DEHP diminished sperm count and quality, leading to a reduced percentage of pregnant females mated to exposed males. A slight increase in the frequency of prenatal deaths and dominant lethal mutations, as well as a significantly increased percentage of abnormal skeletons among the F1 offspring of males exposed to 8,000 mg/kg of DEHP, were observed. Exposure of the fathers did not cause a delay in the postnatal development of the offspring, except for fur development in the group of 8,000 mg/kg of DEHP. Gametes of male offspring of exposed fathers showed reduced motility. The results may suggest that diminished spermaozoa quality induced by DEHP may be coincidental with mutations leading to intrauterine deaths and skeletal abnormalities in the offspring.

[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.

Is concentration and motility of male gametes related to DNA damage measured by comet assay?

Approximately 8 percent of couples in the World have problem with offspring production. Male infertility, which is the reason of the half of reproduction failures, is connected with diminished sperm production and deterioration of its quality. One important factor which affects fertility is the appearance of DNA damage in germ cells leading to enhanced frequency of mutations. This study aimed to compare the frequency of DNA damage in human spermatozoa in samples of different sperm concentration and motility. The anonymous sperm sample donors were men aged from 20-44 years, couples of pregnant females. Sperm concentration, motility and DNA damage measured by Comet assay were estimated. The following parameters were chosen for analysis of DNA damage: percent of DNA in comet head, comet tail length, tail moment. There were no differences in the mean DNA damage in male gametes between different age groups of donors, nor between samples of different sperm motility. The correlation between low sperm concentration in ejaculate and enhanced level of DNA damage was observed. The highest DNA damage was noted in samples with low sperm concentration. In gametes from this group, the lowest percent of DNA in comet head, the highest mean tail length, and the highest tail moment were observed.

The effects of di-n-butyl phthalate on the germ cells of laboratory mice.

Phthalate are found in the environmental samples due to their wide use in the industry as plasticizers. Di-n-butylphthalate (DBP) is mainly used in nitrocellulose and polyvinyl acetate products as well as in personal-care products. This study was performed to investigate the influence of exposure to DBP on the quantity and quality (motility, morphology) and DNA damage (induction of micronuclei and DNA strand breaks) of male mice gametes. The estimation of DBP residues was also done. Eight weeks exposure to DBP (500 mg/kg bw and 2000 mg/kg bw) did not significantly affect testes and epididymes weights as well as sperm count. DBP clearly diminished sperm motility, enhanced frequency of abnormal sperm heads and not significantly increased DNA strand breaks in germ cells as well as frequency of micronuclei in spermatids. There were no bioacumulation of DBP in mice. Results suggest that DBP may affect the male mice germ cells.

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.

[Effects of subchronic exposure of laboratory mice to benzylbutyl phthalate (BBP) on the quantity and quality of male germ cells]. / Badanie wplywu ftalanu butylobenzylu (BBP) na ilosc i jakosc gamet meskich przy subchronicznym narazeniu myszy laboratoryjnych.

The aim of the study was to investigate the effect of 8-weeks exposure of male mice to benzyl butyl phthalate (BBP) on the sperm count and quality of gametes. Pzh:Sfis male mice exposed per os to 450 mg/kg bw (1/16 LD50) and to 1800 mg/kg bw (1/4 LD50) of BBP in olive oil were used in the study. Control mice were treated with olive oil only. Groups of animals were killed 4 and 8 weeks after the start of exposure and 4 weeks after he end of exposure. Sperm count, motility, morphology and DNA damage in gametes were estimated in the study. Sperm counts were diminished 4 and 8 weeks after the start of exposure to BBP. In the same time decrease in sperm motility and dose-dependent increase in the frequency of abnormal sperm heads and slight increase in DNA damage were noted. 4 weeks after the end of exposure, slight decrease in sperm counts in the group of 1/4 LD50 was observed, only. Correlation between sperm count and testes and epididymes weight were noted. Themost sensitive to BBP exposure occurred spermatozoa and spermatids.