BUB1 and BUBR1 inhibition decreases proliferation and colony formation, and enhances radiation sensitivity in pediatric glioblastoma cells

Purpose

Glioblastoma (GBM) is a very aggressive and lethal brain tumor with poor prognosis. Despite new treatment strategies, patients’ median survival is still lower than 1 year in most cases. The expression of the BUB gene family has demonstrated to be altered in a variety of solid tumors, pointing to a role as putative therapeutic target. The purpose of this study was to determine BUB1, BUB3, and BUBR1 gene expression profiles in glioblastoma and to analyze the effects of BUB1 and BUBR1 inhibition combined or not with Temozolomide and radiation in the pediatric SF188 GBM cell line.

Methods

For gene expression analysis, 8 cell lines and 18 tumor samples were used. The effect of BUB1 and BUBR1 inhibition was evaluated using siRNA. Apoptosis, cell proliferation, cell cycle kinetics, micronuclei formation, and clonogenic capacity were analyzed after BUB1 and BUBR1 inhibition. Additionally, combinatorial effects of gene inhibition and radiation or Temozolomide (TMZ) treatment were evaluated through proliferation and clonogenic capacity assays.

Results

We report the upregulation of BUB1 and BUBR1 expression and the downregulation of BUB3 in GBM samples and cell lines when compared to white matter samples (p?<?0.05). Decreased cell proliferation and colony formation after BUB1 and BUBR1 inhibition were observed, along with increased micronuclei formation. Combinations with TMZ also caused cell cycle arrest and increased apoptosis. Moreover, our results demonstrate that BUB1 and BUBR1 inhibition sensitized SF188 cells to γ-irradiation as shown by decreased growth and abrogation of colony formation capacity.

Conclusion

BUB1 and BUBR1 inhibition decreases proliferation and shows radiosensitizing effects on pediatric GBM cells, which could improve treatment strategies for this devastating tumor. Collectively, these findings highlight the potentials of BUB1 and BUBR1 as putative therapeutic targets for glioblastoma treatment.     

Combined Immunodeficiency Evolving into Predominant CD4+ Lymphopenia Caused by Somatic Chimerism in JAK3

Purpose

Idiopathic CD4 lymphopenia constitutes a heterogeneous group of immunodeficiencies with characteristically low CD4+ T-cell counts with largely unknown genetic etiology. We here sought to determine the underlying molecular cause in an index family with two patients suffering from combined immunodeficiency that evolved into predominant CD4+ lymphopenia. The more severely affected index patient also presented with selective antibody deficiency against bacterial polysaccharide antigens.

Methods

For the genetic analysis, we used combined homozygosity mapping and exome sequencing. Functional assays included immunoblot analysis, flow cytometry and TCR Vβ spectratyping.

Results

A novel homozygous missense mutation was revealed in the kinase domain of JAK3 (c.T3196C, p.Cys1066Arg). Further analysis showed revertant chimerism in CD8+ T-cells in both patients. The additional presence of revertant CD4+ T-cells was associated with a milder clinical and immunological phenotype in the second patient, although the role somatic chimerism plays in amelioration of disease phenotype is uncertain, as presence of revertant cells had no effect on residual CD4 cell JAK3 signaling function. Residual activity of JAK3-dependent STAT3 and STAT5 signaling was also found in immortalized B-cell lines indicating a hypomorphic nature of the described mutation which likely contributes to the milder clinical phenotype.

Conclusions

We here present the first case of revertant mosaicism in JAK3 deficiency, manifesting as combined immunodeficiency evolving into predominant CD4+ lymphopenia. Revertant chimerism or hypomorphic mutations in genes typically associated with more severe T-cell deficiency should be considered when assessing patients with milder forms of combined immunodeficiencies.     

Prevalence of Altered Passive Eruption in Orthodontically Treated and Untreated Patients

Background: Some authors have reported that after orthodontic treatment (OT), a “gummy smile” might develop. Nevertheless, there are no studies in the literature that investigate whether OT increases the presence of altered passive eruption (APE). The primary aim of this cross‐sectional study is to evaluate the prevalence of APE after OT (OT group) and compare it with patients who never received OT (control group). A secondary aim is to identify which variables are related to APE. Methods: The study population consisted of 190 patients (95 patients each in the control and OT groups), providing 1,140 anterior teeth for the clinical examination. The following clinical parameters were assessed: presence or absence of APE, clinical crown length, and gingival biotype, which was divided into three categories: thin‐scalloped, thick‐flat, and thick‐scalloped. Results: Twenty‐eight patients (29.5%) were diagnosed with APE in the control group and 40 (42.1%) in the OT group, although this difference was not statistically significant (P = 0.07). Furthermore, 34 (75.6%) patients with thick‐flat biotype were diagnosed with APE, whereas 30 (31.3%) and four (8.2%) with thick‐scalloped and thin‐scalloped biotypes, respectively, had APE. These differences were statistically significant (P <0.001). Conclusions: It was concluded that: 1) the prevalence of APE is higher after OT but not to a statistically significant degree and 2) APE is more common in individuals with a thick‐flat gingival biotype.     

Prognostic Value of Serum Neutrophil Gelatinase-Associated Lipocalin in Metastatic and Nonmetastatic Colorectal Cancer

Background

Neutrophil gelatinase-associated lipocalin (NGAL) expression is increased in epithelial cancer patients, but studies showing its relation to prognosis are scarce. We aimed to test the ability of preoperative serum NGAL levels (pNGAL) to predict recurrence in metastatic and nonmetastatic colorectal cancer (CRC) patients.

Methods

This retrospective study determined pNGAL levels in 60 healthy individuals, 47 patients with nonmetastatic CRC, and 70 patients with metastatic CRC undergoing curative neoplastic resection. Patients were divided into low- and high-pNGAL groups using a median series-based cutoff.

Results

The mean ± SD pNGAL in CRC patients (nonmetastatic and metastatic) was 102.3 ± 66.6 (median 91.4). Nonmetastatic CRC and metastatic CRC patients had higher pNGAL than healthy controls (88 ± 64 and 112 ± 67 vs. 0.6 ± 0.3, respectively, both p < 0.0001). Nonmetastatic CRC patients with deeper tumor invasion and metastatic CRC patients with shorter disease-free interval after CRC resection had higher pNGAL. pNGAL levels correlated with neoplastic tissue volume. CRC patients with recurrence had higher pNGAL than those without recurrence (118 ± 64 vs. 88 ± 66, p = 0.013), and high-pNGAL patients had a higher recurrence rate (59.3 vs. 36.2 %, p = 0.016). Median pNGAL-based risk classification had a sensitivity of 62.5 % for predicting neoplastic progression in CRC patients and 74.3 % for predicting neoplastic progression during the first year after metastatic CRC resection.

Conclusions

pNGAL is higher in CRC patients than in the healthy population, which indicates a potential screening role. High-pNGAL levels are associated with higher neoplastic tissue volume, characteristics of neoplastic invasion, and recurrence, showing a prognostic utility mainly in metastatic CRC patients.     

Unexpectedly high mortality in Pacific herring embryos exposed to the 2007 Cosco Busan oil spill in San Francisco Bay

In November 2007, the container ship Cosco Busan released 54,000 gallons of bunker fuel oil into San Francisco Bay. The accident oiled shoreline near spawning habitats for the largest population of Pacific herring on the west coast of the continental United States. We assessed the health and viability of herring embryos from oiled and unoiled locations that were either deposited by natural spawning or incubated in subtidal cages. Three months after the spill, caged embryos at oiled sites showed sublethal cardiac toxicity, as expected from exposure to oil-derived polycyclic aromatic compounds (PACs). By contrast, embryos from the adjacent and shallower intertidal zone showed unexpectedly high rates of tissue necrosis and lethality unrelated to cardiotoxicity. No toxicity was observed in embryos from unoiled sites. Patterns of PACs at oiled sites were consistent with oil exposure against a background of urban sources, although tissue concentrations were lower than expected to cause lethality. Embryos sampled 2 y later from oiled sites showed modest sublethal cardiotoxicity but no elevated necrosis or mortality. Bunker oil contains the chemically uncharacterized remains of crude oil refinement, and one or more of these unidentified chemicals likely interacted with natural sunlight in the intertidal zone to kill herring embryos. This reveals an important discrepancy between the resolving power of current forensic analytical chemistry and biological responses of keystone ecological species in oiled habitats. Nevertheless, we successfully delineated the biological impacts of an oil spill in an urbanized coastal estuary with an overlapping backdrop of atmospheric, vessel, and land-based sources of PAC pollution.