Evaluation of the prognostic potential of EGFL7 in pilocytic astrocytomas.

Pilocytic astrocytoma (PA) is the most frequent solid neoplasm in childhood. It has a good 5-year overall survival (90% in childhood and 52% in adults). However, up to 20% of patients experience residual tumor growth, recurrence, and death. Although the main genetic alteration of PAs, including KIAA1549:BRAF fusion, involves chromosome 7q34, we previously found frequent loss in chr9q34.3 locus in a small subset of these tumors. Among the genes present in this locus, EGFL7 is related to poor prognosis in several tumor types. In this study, we aimed to assess EGFL7 expression through immunohistochemistry, and to evaluate its prognostic value in a series of 64 clinically and molecularly well-characterized pilocytic astrocytomas. We found high expression of EGFL7 in 71.9% of patients. Low EGFL7 expression was associated with older patients, the mean age mainly older than 11 years (P = 0.027). EGFL7 expression was not associated with presence of KIAA1549:BRAF fusion, BRAF mutation, FGFR1 mutation, nor FGFR1 duplication. Moreover, high EGFL7 expression was associated with high FGFR1 (P = 0.037) and 5'-deoxy-5'-methyltioadenosine phosphorylase (MTAP) (P = 0.005) expression, and with unfavorable outcome of patients (P = 0.047). Multivariate analysis revealed low EGFL7 expression related to older patients and high EGFL7 expression related to retained expression of MTAP. In addition, we found a borderline significance of unfavorable outcome and high EGFL7 expression. Finally, EGFL7 expression was not associated with overall or event-free survival of PA patients. Our findings point to EGFL7 expression as a novel candidate prognostic marker in PA, which should be further investigated.

Significance of Chr9p22.1-p21.3 Deletion in Cancer Development: A Pan-cancer In Silico Analysis.

BACKGROUND/AIM: Deletions in chr9p22.1-21.3 locus have been related to the development of several types of cancer, mainly due to the presence of CDKN2A and CDKN2B genes. However, there are several other genes in the region with potential importance in tumorigenesis. We, therefore, aimed to analyze in silico the potential prognostic significance of alterations in copy number and expression of genes present in the chr9p22.1-21.3 locus in 33 TCGA datasets (approximately 10,000 patients). MATERIALS AND METHODS: We analyzed which of the 27 genes are expressed in the datasets. Additionally, we associated the deletion of the locus with survival (log rank analysis) and hazard ratio (HR) (univariate cox regression). Finally, we performed univariate, multivariate, and overall survival analyses in 13 datasets considering the expression of 10 genes present in the locus. RESULTS: We identified 10 genes of the chr9p22.1-21.3 locus expressed in the datasets (MLLT3, FOCAD, PTPLAD2, KLHL9, IFNE, MTAP, CDKN2A, CDKN2B, DMRTA1 and ELAVL2). Moreover, we found that deletion in at least 1 of these genes was associated with poor survival and increased HR in 13 datasets: adrenocortical carcinoma (ACC), glioblastoma (GBM), head and neck squamous cell carcinoma (HNSC), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), low-grade glioma (LGG), lung adenocarcinoma (LUAD), mesothelioma (MESO), pancreatic adenocarcinoma (PAAD), prostate adenocarcinoma (PRAD), rectum adenocarcinoma (READ), sarcoma (SARC) and uterine corpus endometrial carcinoma (UCEC). Finally, we found an association of survival/HR and altered expression of MLLT3 in the MESO dataset, of FOCAD in the READ dataset, of PTPLAD2 in the KIRP dataset, of KLHL9 in the LGG and UCEC datasets, of IFNE in ACC, GBM, KIRC and LUAD datasets, of MTAP in LGG, LUAD and MESO datasets, of CDKN2A in the HNSC, KIRC and MESO datasets, of CDKN2B in the LGG and READ datasets, of DMRTA1 in SARC datasets and of ELAVL2 in the LGG dataset (p<0.01 for all associations). CONCLUSION: Besides CDKN2A and CDKN2B, numerous other genes are possibly related to cancer development, requiring further investigation.