Metabolic pathways enriched according to ERG status are associated with biochemical recurrence in Hispanic/Latino patients with prostate cancer.

BACKGROUND: The role of ERG-status molecular subtyping in prognosis of prostate cancer (PCa) is still under debate. In this study, we identified differentially expressed genes (DEGs) according to ERG-status to explore their enriched pathways and implications in prognosis in Hispanic/Latino PCa patients. METHODS: RNA from 78 Hispanic PCa tissues from radical prostatectomies (RP) were used for RNA-sequencing. ERGhigh /ERGlow tumor groups were determined based on the 1.5-fold change median expression in non-tumor samples. DEGs with a False Discovery Rate (FDR) < 0.01 and a fold change >2 were identified between ERGhigh and ERGlow tumors and submitted to enrichment analysis in MetaCore. Survival and association analyses were performed to evaluate biochemical recurrence (BCR)-free survival. RESULTS: The identification of 150 DEGs between ERGhigh and ERGlow tumors revealed clustering of most of the non-BCR cases (60%) into de ERGhigh group and most of the BCR cases (60.8%) in ERGlow group. Kaplan-Meier survival curves showed a worst BCR-free survival for ERGlow patients, and a significant reduced risk of BCR was observed for ERGhigh cases (OR = 0.29 (95%CI, 0.10-0.8)). Enrichment pathway analysis identified metabolic-related pathways, such as the renin-angiotensin system and angiotensin maturation system, the linoleic acid metabolism, and polyamines metabolism in these ERG groups. CONCLUSIONS: ERGlow tumor cases were associated with poor BCR-free survival in our Hispanic/Latino patients, with metabolism-related pathways altered in the BCR progression. IMPACT: Our findings suggest the need to dissect the role of diet, metabolism, and lifestyle as risk factors for more aggressive PCa subtypes.

Ancestry as a potential modifier of gene expression in breast tumors from Colombian women.

BACKGROUND: Hispanic/Latino populations are a genetically admixed and heterogeneous group, with variable fractions of European, Indigenous American and African ancestries. The molecular profile of breast cancer has been widely described in non-Hispanic Whites but equivalent knowledge is lacking in Hispanic/Latinas. We have previously reported that the most prevalent breast cancer intrinsic subtype in Colombian women was Luminal B as defined by St. Gallen 2013 criteria. In this study we explored ancestry-associated differences in molecular profiles of Luminal B tumors among these highly admixed women. METHODS: We performed whole-transcriptome RNA-seq analysis in 42 Luminal tumors (21 Luminal A and 21 Luminal B) from Colombian women. Genetic ancestry was estimated from a panel of 80 ancestry-informative markers (AIM). We categorized patients according to Luminal subtype and to the proportion of European and Indigenous American ancestry and performed differential expression analysis comparing Luminal B against Luminal A tumors according to the assigned ancestry groups. RESULTS: We found 5 genes potentially modulated by genetic ancestry: ERBB2 (log2FC = 2.367, padj<0.01), GRB7 (log2FC = 2.327, padj<0.01), GSDMB (log2FC = 1.723, padj<0.01, MIEN1 (log2FC = 2.195, padj<0.01 and ONECUT2 (log2FC = 2.204, padj<0.01). In the replication set we found a statistical significant association between ERBB2 expression with Indigenous American ancestry (p = 0.02, B = 3.11). This association was not biased by the distribution of HER2+ tumors among the groups analyzed. CONCLUSIONS: Our results suggest that genetic ancestry in Hispanic/Latina women might modify ERBB2 gene expression in Luminal tumors. Further analyses are needed to confirm these findings and explore their prognostic value.