Gene expression analyses determine two different subpopulations in KIT-negative GIST-like (KNGL) patients

Introduction: There are limited findings available on KIT-negative GIST-like (KNGL) population. Also, KIT expression may be post-transcriptionally regulated by miRNA221 and miRNA222. Hence, the aim of this study is to characterize KNGL population, by differential gene expression, and to analyze miRNA221/222 expression and their prognostic value in KNGL patients. Methods: KIT, PDGFRA, DOG1, IGF1R, MIR221 and MIR222 expression levels were determined by qRT-PCR. We also analyzed KIT and PDGFRA mutations, DOG1 expression, by immunohistochemistry, along with clinical and pathological data. Disease-free survival (DFS) and overall survival (OS) differences were calculated using Log-rank test. Results: Hierarchical cluster analyses from gene expression data identified two groups: group I had KIT, DOG1 and PDGFRA overexpression and IGF1R underexpression and group II had overexpression of IGF1R and low expression of KIT, DOG1 and PDGFRA. Group II had a significant worse OS (p = 0.013) in all the series, and showed a tendency for worse OS (p = 0.11), when analyzed only the localized cases. MiRNA222 expression was significantly lower in a control subset of KIT-positive GIST (p < 0.001). OS was significantly worse in KNGL cases with higher expression of MIR221 (p = 0.028) or MIR222 (p = 0.014). Conclusions: We identified two distinct KNGL subsets, with a different prognostic value. Increased levels of miRNA221/222, which are associated with worse OS, could explain the absence of KIT protein expression of most KNGL tumors

Soft tissue and visceral sarcomas: ESMO-EURACAN Clinical Practice Guidelines for diagnosis, treatment and follow-up

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Gastrointestinal stromal tumours: ESMO-EURACAN-GENTURIS Clinical Practice Guidelines for diagnosis, treatment and follow-up.

Experimentele farmacotherapi

Soft tissue and visceral sarcomas: ESMO-EURACAN-GENTURIS Clinical Practice Guidelines for diagnosis, treatment and follow-up^☆.

Experimentele farmacotherapi

Bone sarcomas: ESMO-EURACAN-GENTURIS-ERN PaedCan Clinical Practice Guideline for diagnosis, treatment and follow-up.

A. Kawai43, K. Kopeckova44, D. A. Krakorova45, A. Le Cesne46, F. Le Grange1, E. Legius47, A. Leithner48, A. Lopez Pousa49, J. Martin-Broto36, O. Merimsky50, C. Messiou51, A. B. Miah52, O. Mir53, M. Montemurro54, B. Morland55, C. Morosi56, E. Palmerini57, M. A. Pantaleo58, R. Piana59, S. Piperno-Neumann60, P. Reichardt61, P. Rutkowski62, A. A. Safwat63, C. Sangalli64, M. Sbaraglia19, S. Scheipl48, P. Schoffski65, S. Sleijfer66, D. Strauss67, K. Sundby Hall13, A. Trama68, M. Unk69, M. A. J. van de Sande70, W. T. A. van der Graaf66,71, W. J. van Houdt72, T. Frebourg73x, R. Ladenstein41z, P. G. Casali2,74z &Experimentele farmacotherapi