Resilience in Lower Grade Glioma Patients

Current data show that resilience is an important factor in cancer patients’ well-being. We aim to explore the resilience of patients with lower grade glioma (LGG) and the potentially influencing factors. We performed a cross-sectional assessment of adult patients with LGG who were enrolled in the LoG-Glio registry. By phone interview, we administered the following measures: Resilience Scale (RS-13), distress thermometer, Montreal Cognitive Assessment Test for visually impaired patients (MoCA-Blind), internalized stigmatization by brain tumor (ISBI), Eastern Cooperative Oncological Group performance status (ECOG), patients’ perspective questionnaire (PPQ) and typical clinical parameters. We calculated correlations and multivariate regression models. Of 74 patients who were assessed, 38% of those showed a low level of resilience. Our results revealed significant correlations of resilience with distress (p < 0.001, −0.49), MOCA (p = 0.003, 0.342), ECOG (p < 0.001, −0.602), stigmatization (p < 0.001, −0.558), pain (p < 0.001, −0.524), and occupation (p = 0.007, 0.329). In multivariate analyses, resilience was negatively associated with elevated ECOG (p = 0.020, β = −0.383) and stigmatization levels (p = 0.008, β = −0.350). Occupation showed a tendency towards a significant association with resilience (p = 0.088, β = −0.254). Overall, low resilience affected more than one third of our cohort. Low functional status is a specific risk factor for low resilience. The relevant influence of stigmatization on resilience is a novel finding for patients suffering from a glioma and should be routinely identified and targeted in clinical routine.

The cohesin-interacting protein, precocious dissociation of sisters 5A/sister chromatid cohesion protein 112, is up-regulated in human astrocytic tumors

Glioblastoma multiforme (GBM) is the most prevalent, highly malignant, invasive and difficult-to-treat primary brain tumor in adults. At the genetic level, it is characterized by a high degree of chromosomal instability and aneuploidy. It has been shown that defects in the mitotic spindle checkpoint could lead to the development of aneuploidy as well as tumorigenesis. Additional proteins regulating sister chromatid cohesion could also be involved in maintaining the fidelity of chromosome segregation. One such protein is the precocious dissociation of sisters 5A (Pds5A), also known as sister chromatid cohesion protein 112. It is a nuclear protein, expressed from the S right through to the mitotic phase. It is highly conserved from yeast to man and plays a role in the establishment, maintenance and dissolution of sister chromatid cohesion. The mutation of Pds5A orthologs in lower organisms results in chromosome missegregation, aneuploidy and DNA repair defects. It is considered that such defects can cause either cell death or contribute to the development of cancer cells. Indeed, altered expression levels of Pds5A have been observed in tumors of the breast, kidney, oesophagus, stomach, liver and colon. Malignant gliomas, however, have not been analysed so far. Herein, we report on the cloning of Rattus norvegicus Pds5A and on the analysis of its expression pattern in rat tissue. We also show that Pds5A is significantly overexpressed at both the mRNA and protein level and that this overexpression correlates positively with the WHO grade of human gliomas. However, functional assays show that the siRNA-mediated knockdown of Pds5A affects sister chromatid cohesion but does not influence mitotic checkpoint function or the proliferation and survival of GBM cells. Although the mechanism by which Pds5A functions in GBM cells remains unclear, its overexpression in high grade gliomas implies that it could play a pivotal role during the development and progression of astrocytic tumors.

Specificity of antibodies directed against Env protein of human endogenous retroviruses in patients with germ cell tumors

We report here that 85% of the patients with germ cell tumors (GCTs) produce antibodies directed against Env protein of human endogenous retroviruses. Individuals that received antitumor treatment showed a decrease with time in their antibody titers. Importantly, of the rare cases of non-GCT individuals with Env-antibodies (n= 15, 0.8%), none produced antibodies directed against the transmembrane domain (TM), whereas all tested Env-positive GCT patients (n= 49) generated such antibodies at high titers. TM is required for Env to be expressed at the cell surface. Thus, anti-TM antibodies constitute highly specific markers for GCT and may hint at a function of Env during tumorigenesis.

Characterization of the human endogenous retrovirus K proteinase

The proteinase of the human endogenous retrovirus K (HERV-K) shows similarity to retrovirus aspartic proteinases. It is translated from a transcript composed of gag and prt. The proteinase was expressed either as full-length native protein or as truncated protein in Escherichia coli. Functional protein was demonstrated by its autocatalytic cleavage into an 18 kDa fragment recognized by a polyclonal antiserum. This autocatalytic cleavage was specifically inhibited by a human immunodeficiency virus type 1 proteinase inhibitor. The HERV-K proteinase expressed in E. coli was capable of cleaving HERV-K Gag translated in vitro. Major protein fragments of 39 and 30 kDa, and minor protein fragments of 26, 22 and 21 kDa were obtained. Similar fragments are also observed in the human teratocarcinoma cell line Tera1. Our data suggest that the HERV-K proteinase is functionally equivalent to other retrovirus proteinases and thus probably functions in the processing of Gag precursor protein.

Human endogenous retroviral element k10 (HERV-K10): chromosomal localization by somatic hybrid mapping and fluorescence in situ hybridization

The human endogenous retrovirus K10 (HERV-K10) was mapped to human chromosomes using HERV-K10 specific PCR primers on a somatic hybrid mapping panel. A non-random chromosomal location was demonstrated with PCR signals on chromosomes 1, 3, 4, 5, 6, 7, 10, 11, 12, 14, 15, 19, 20, 21, 22 and Y. There was a lack of PCR products on the other chromosomes, even after hybridization with a HERV-K10 specific probe. To further localize the HERV-K10 sequence we used fluorescence in situ hybridization. Chromosomes 1, 3, 6, 7, 10, 11, 12 and 22 were found to contain several HERV-K10 sequences in different regions. The presence of several integration sites on some chromosomes is consistent with previous studies demonstrating 30-50 copies of the HERV-K10 sequence per haploid genome. The mapping information reported in this study will assist the analysis of the biological significance of the HERV-K10 sequence.

Human endogenous retrovirus K10: expression of Gag protein and detection of antibodies in patients with seminomas

The human endogenous retrovirus K10 (HERV-K10) has been identified in the human genome by its homology to retroviruses of other vertebrates (M. Ono, T. Yasunaga, T. Miyata, and H. Ushikubo, J. Virol. 60:589-598, 1986). Using PCR amplification, DNA cloning, sequencing, and procaryotic expression, we were able to demonstrate that HERV-K10 encodes a 73-kDa protein which was processed by a HERV-K10-encoded protease to yield proteins p22/p26, p30, and p15/16. Analysis of the teratocarcinoma cell line Tera 1 or tumor tissues by immunoblotting demonstrated that the 80-kDa polyprotein of HERV-K10 gag and a processed protein of 39 kDa were expressed. In addition, a major protein of 39 kDa and additional species of 30, 22, 19, and 17 kDa could be detected in the supernatant of Tera 1 cells, suggesting that HERV-K10 Gag proteins are either secreted or processed to probably incomplete viral particles. In addition, the gag gene of HERV-K10 was expressed in the baculovirus system. Using this recombinant system to test antisera from patients with different diseases and healthy individuals, we were able to detect antibodies against the N-terminal part of HERV-K10 Gag in 2 to 4% of groups of tumor patients with titers ranging between 1:80 and 1:640, while approximately 0.1 to 0.5% of healthy individuals exhibited antibodies with lower titers. In contrast, patients with seminoma had antibody titers in the range of 1:2,560 at the time when the tumor was detected. Immunohistochemistry using specific rabbit sera or monoclonal antibodies against HERV-K10 Gag revealed that the Gag protein is expressed in the cytoplasm of the tumor cells. Furthermore, an 80-kDa protein corresponding to the HERV-K10 Gag polyprotein could be detected in tumor biopsies. For the first time, these data indicate that HERV-K10 Gag proteins are synthesized in seminoma cells and tumors exhibit relatively high antibody titers against Gag. So far, no information on which role HERV-K10 plays in the development of this tumor exists.