Fine mapping of an imprinted gene for familial nonchromaffin paragangliomas, on chromosome 11q23
AMERICAN JOURNAL OF HUMAN GENETICS
Authors: Baysal, BE; Farr, JE; Rubinstein, WS; Galus, RA; Johnson, KA; Aston, CE; Myers, EN; Johnson, JT; Carrau, R; Kirkpatrick, SJ; Myssiorek, D; Singh, D; Saha, S; Gollin, SM; Evans, GA; James, MR; Richard, CW
Abstract
Hereditary nonchromaffin paragangliomas (PGL; glomus tumors; MIM 168000) are mostly benign, slow-growing tumors of the head and neck region, inherited from carrier fathers in an autosomal dominant fashion subject to genomic imprinting. Genetic linkage analysis in two large, unrelated Dutch families assigned PGL loci to two regions of chromosome 11, at 11q23 (PGL1) and 11q13.1 (PGL2). We ascertained a total of 11 North American PGL families and confirmed maternal imprinting (inactivation). In three of six families, linkage analysis provided evidence of linkage to the PGL1 locus at 11q23. Recombinants narrowed the critical region to an similar to 4.5-Mb interval flanked by markers D11S1647 and D11S622. Partial allelic loss of strictly maternal origin was detected in 5 of 19 tumors. The greatest degree of imbalance was detected at 11q23, distal to D11S1327 and proximal to CD3D. Age at onset of symptoms was significantly different between fathers and children (Wilcoxon rank-sum test, P < .002). Affected children had an earlier age at onset of symptoms in 39 of 57 father-child pairs (chi(2) = 7.74, P < .006). However, a more conservative comparison of the number of pairs in which a child had greater than or equal to 5 years earlier age at onset (n = 33) vis-a-vis that of complementary pairs (n = 24) revealed no significant difference (chi(2) = 1.42, P > .2). Whether these data represent genetic anticipation or ascertainment bias can be addressed only by analysis of a larger number of father-child pairs.
Changes in Expression of Genes Representing Key Biologic Processes after Neoadjuvant Chemotherapy in Breast Cancer, and Prognostic Implications in Residual Disease
CLINICAL CANCER RESEARCH
Authors: Klintman, Marie; Buus, Richard; Cheang, Maggie Chon U.; Sheri, Amna; Smith, Ian E.; Dowsett, Mitch
Abstract
Purpose: The primary aim was to derive evidence for or against the clinical importance of several biologic processes in patients treated with neoadjuvant chemotherapy (NAC) by assessing expression of selected genes with prior implications in prognosis or treatment resistance. The secondary aim was to determine the prognostic impact in residual disease of the genes' expression. Experimental Design: Expression levels of 24 genes were quantified by NanoString nCounter on formalin-fixed paraffin-embedded residual tumors from 126 patients treated with NAC and 56 paired presurgical biopsies. The paired t test was used for testing changes in gene expression, and Cox regression and penalized elastic-net Cox Regression for estimating HRs. Results: After NAC, 12 genes were significantly up-and 8 downregulated. Fourteen genes were significantly associated with time to recurrence in univariable analysis in residual disease. In a multivariable model, ACACB, CD3D, MKI67, and TOP2A added prognostic value independent of clinical ER+, PgR(-) and HER2(-) tatus. In ER+/HER2(-) patients, ACACB, PAWR, and ERBB2 predicted outcome, whereas CD3D and PAWR were prognostic in ER+/HER2(-) patients. By use of elastic-net analysis, a 6-gene signature (ACACB, CD3D, DECORIN, ESR1, MKI67, PLAU) was identified adding prognostic value independent of ER, PgR, and HER2. Conclusions: Most of the tested genes were significantly enriched or depleted in response to NAC. Expression levels of genes representing proliferation, stromal activation, metabolism, apoptosis, stemcellness, immunologic response, and Ras-ERK activation predicted outcome in residual disease. Themultivariable gene models identified could, if validated, be used to identify patients needing additional post-neoadjuvant treatment to improve prognosis. (C) 2016 AACR.