Bionano Genomics, Inc. (NASDAQ:BNGO) today announced the publication of a study of optical genome mapping (OGM) in hereditary breast and ovarian cancer (HBOC) syndrome showing that when tumors exhibited higher overall numbers of structural variations (SVs) they tended to have more mutated genes and altered signaling pathways, which may correlate with poor prognosis, tumor progression and chemotherapy resistance. Researchers also found that OGM was able to detect chromothripsis events and novel gene fusions in cancer tissues with high accuracy, including novel gene fusions that were not detected by other methods.
HBOC syndrome is estimated to cause 5-10% of all breast cancers and is commonly characterized by harmful germline mutations in the BRCA1 or BRCA2 genes. Due to limitations inherent in common methods of genome analysis, researchers have limited knowledge regarding the potential impact of structural abnormalities and SV heterogeneity in HBOC-related cancers. The study authors selected OGM for this analysis due to its ability to detect multiple classes of SVs with genome-wide coverage, high resolution and accuracy.
Study authors categorized the HBOC-related breast cancer samples into two groups, SVhigh and SVlow, based on the number of SVs detected by OGM, high or low Ki-67 expression, and the number of mutated genes and altered signaling pathways. The authors noted that SVhigh samples were associated with higher Ki-67 expression and higher homologous recombination deficiency (HRD) scores, indicating that genetic alterations may have potential predictive and therapeutic significance. The SVhigh samples also showed higher numbers of chromothripsis events and novel gene fusions than the SVlow samples. Eight novel gene fusions were identified by OGM, including three that had not previously been detected by other methods of analysis. These gene fusions may be involved in drug resistance and tumor development.
"We are pleased to see the publication of this study, which highlights OGM as a promising tool for detecting novel variants in HBOC-related breast cancer that have oncogenic potential. We believe the comprehensive assessment of the role SVs play in breast cancers with abnormal DNA repair functions might expand our current understanding of disease progression and precision medicine in breast cancer," commented Erik Holmlin, PhD, president and chief executive officer of Bionano.