A recurrent NTRK1 tyrosine kinase domain mutation pair is characteristic in a subset of dedifferentiated liposarcomas.

INTRODUCTION: Dedifferentiated liposarcoma (DDLPS) is a common form of liposarcoma with challenging treatment modalities. Pan-TRK immunopositivity can be often observed without NTRK gene fusion in soft tissue sarcomas with myogenic differentiation. Expression and the role of NTRK in DDLPS are under-studied. We sought to identify activating mutations of the NTRK genes. MATERIALS AND METHODS: 131 DDLPS patients were selected for pan-TRK immunohistochemistry and positive cases were analyzed by Sanger sequencing for NTRK1, NTRK2 and NTRK3 genes. Functional assays were performed using a lentiviral transduction system to study the effect of NTRK variants in fibroblast, immortalized fibroblast, and dedifferentiated liposarcoma cell lines. RESULTS: Out of the 131 DDLPS cases, 75 immunohistochemical staining positive cases, 46 were successfully Sanger sequenced. A recurrent somatic mutation pair in cis position (NGS) of the NTRK1 c.1810C>T (p.H604Y) and c.1838G>T (p.G613V) was identified in six cases (13%) that have never been reported in DDLPS. NTRK fusions were excluded in all six cases by FISH and NGS. The phospho-AKT immunopositivity among the six mutated cases suggested downstream activation of the NTRK signaling pathway. Functional assays showed no transforming effects, but resistance to first- and second-line TRK inhibitors of the p.G613V and p.H604Y variant. CONCLUSIONS: We detected (de novo/somatic) missense mutation variants in cis position of the NTRK1 gene in a subset of DDLPS indicating modifying mutations that may contribute to tumorigenesis in a subset of DDLPS. These variants beget resistance to TRK inhibitors indicating an interesting biomarker for other studies with TRK inhibitors.

The Activation of PDGFRß on Mononuclear Stromal/Tumor Cells in Giant Cell Tumor of Bone After Denosumab Treatment. An Immunohistochemical Study of Five Cases.

Due to the relatively high recurrence rate and the destructive nature of the tumor, the treatment of giant cell tumor is still a challenge. Denosumab appeared to be a promising candidate as a therapeutic drug. However, several studies have reported that tumors can recur during/after treatment with denosumab. Based on activated receptor tyrosine kinase signaling pattern of the stromal/tumor cells, a combination treatment with denosumab and sunitinib has recently been proposed to inhibit recurrences. This prompted us to investigate the PDGFRß expression of five denosumab treated cases using both primary and recurrent tumors during and after denosumab treatment. In addition, to recognise morphological changes, immunohistochemical analysis of H3F3A and PDGFRß was also performed. As an effect of denosumab treatment, the permanent absence of giant cells associated with severe to mild fibrosis was the most consistent morphological change, but H3F3A positive stromal/tumor cells were observed in all cases. Furthermore, an increased immunopositivity of PDGFRß in stromal/tumor cells was evident in all recurrent cases during denosumab treatment. Upon tumor recurrence (after the discontinuation of denosumab treatment) the intensity of PDGFRß immunostaining in stromal/tumor cells was restored/decreased. Our results confirm (for the first time) the activation of PDGFRß on mononuclear stromal/tumor cells at protein level as an effect of denosumab treatment, which has so far only been demonstrated by phosphoprotein array analysis (protein lysates). The decreased PDGFRß activity after the discontinuation of denosumab treatmeant and the increased PDGFRß activity during denosumab treatment underlines the need for denosumab and sunitinib combination therapy.

Nodular fasciitis: a comprehensive, time-correlated investigation of 17 cases.

The self-limited nature of nodular fasciitis (NF) is well-known but its precise mechanism has not yet been clarified. We observed that "young" NF (preoperative duration <1 month) consistently contains a higher percentage (~80%) of USP6 break-apart FISH signals than "old" NF (preoperative duration >3 months) (~20%). Thus, we hypothesized that our original observation may reflect a connection with the self-limited nature of NF. Seventeen cases with reliable data concerning the onset were selected, thus approximating the lifetime of each tumor. Besides the USP6 interphase FISH examination, we also checked the most common MYH9-USP6 fusion using RT-PCR. Because of the known pathways of the tumorigenesis of NF, the mRNA level of USP6, TRAIL, IFN-beta, JAK1, STAT1, STAT3, JUN, and CDKN2A was measured using qRT-PCR. Regarding proteins, USP6, p16, p27, TRAIL, and IFN-beta were examined using immunohistochemistry. Targeted gene panel next-generation sequencing (NGS) of three cases was additionally performed. We found a strong negative correlation (p = 0.000) between the lifetime and percentage of USP6 break-apart signals and a strong positive relationship (p = 0.000) between USP6 break-apart signals and mitotic counts. Results of immunostainings, along with qRT-PCR results, favored the previously-suggested USP6-induced negative feedback mechanism through activation of TRAIL and IFN-beta, likely resulting in apoptosis and senescence of tumor cells harboring USP6 fusions. Targeted-NGS resulted in the detection of several variants, but no additional recurrent changes in the pathogenesis of these tumors. We revealed on a cellular level the USP6-induced negative feedback mechanism. In conclusion, we emphasize that in "old" NF, the percentage of USP6 break-apart FISH signals can be as low as 14-27% which can be very important from a differential diagnostic point of view. We emphasize that a careful examination and interpretation of the NGS data is needed before clinical decision-making on treatment.

Evaluation of osteoarthritis knee and hip quality of life (OAKHQoL): adaptation and validation of the questionnaire in the Hungarian population.

BACKGROUND: At least 17% of the population suffers from osteoarthritis (OA) in Hungary, according to the European Health Interview Survey. In Hungary, until now there was no OA-specific questionnaire available for the lower limb, in order to monitor the health-related quality of life (HRQoL). This gap gave the relevance of this research. The aim of the study was to perform the Hungarian cross-cultural adaptation and validation of the French-developed Osteoarthritis Knee and Hip Quality of Life (OAKHQoL) questionnaire. METHODS: The five-step translation procedure of the original OAKHQoL was performed by the expert panel and the translators. The created Hungarian version (OAKHQoL-HUN) was tested in six different geographical areas of Hungary. The validity and the reliability of this adapted tool was analyzed by our research group. RESULTS: A total of 99 patients completed the questionnaires (78 women and 21 men), with the average age of 66.6 years (standard deviation (SD) 12.1), living with OA for more than 10 years. Excellent internal consistency was observed in the following domains: physical activity (α = 0.93), mental health (α = 0.91) and pain (α = 0.89). Good correlation was determined between physical subscales (r = 0.615-0.676) and mental subscales (r = 0.633-0.643) compared to generic quality of life instruments (World Health Organization Quality of life - BREF questionnaire and EQ-5D-3L). CONCLUSION: The OAKHQoL-HUN is the first valid and reliable tool for measuring the Hungarian lower limb OA patients' quality of life. TRIAL REGISTRATION: This study is registered (24950-3/2016/EKU) by the National Ethics Committee: the Hungarian Medical Research Council.

[Investigation of the genetic background of complex diseases]. / Komplex jellegek genetikai hátterének elemzése.

Although the Human Genome Project discovered the sequence of the human genetic information 15 years ago, genetic background of the diseases - primarily that of complex disorders - is still not known. The sum of the not yet discovered inherited risk factors is termed the missing heritability; the identification of these genetic components is, however, essential, as it is the base of the understanding of the molecular pathomechanism of diseases. It is not only of theoretical importance: this knowledge can be used in the clinical practice, as it offers the possibility of improvement of diagnostics, prevention as well as targeted and individualized therapy. Application of novel and more efficient molecular biological tools contribute to the discovery of unknown genetic factors, the complete goal can only be achieved, however, by re-conceptualization of several clinical and genetic points. Our knowledge was established by genome-wide studies, however, further knowledge must be acquired according to the following points: (1) genotype and association analysis of repeat variations (VNTRs and CNVs) besides SNPs, (2) investigation of gene-gene and gene-environment interactions, (3) epigenetic studies, (4) assessing the biological function of polymorphisms, (5) application of biologically relevant diagnostic categories and endophenotypes. Although it is only 1.2% of the whole genome that codes for proteins, however, as much as 90% is transcribed to RNA, consequently it can be hypothesized that gene expression analyses might offer promising starting points for further studies, as they can shed light on the molecular processes that contribute to the development of diseases. Orv Hetil. 2018; 159(31): 1254-1261.

[Neurorehabilitation, neurology, rehabilitation medicine]. / Neurorehabilitáció, neurológia, rehabilitácios medicina.

We have read several publications of great authority on the neurological profession in the last two years in which were expressed assessments of the current situation combined with opinions about neurology and the necessity to reorganize neurological patient care. These articles took up the question of neurorehabilitation too. The authors, who on a daily basis, deal with the rehabilitation of people with disabilities as a consequence of neurological conditions, summarize some important definitions of rehabilitation medicine and the present system of neurological rehabilitation, as it is defined by the rehabilitation profession.