Next-generation sequencing of non-small cell lung cancer using a customized, targeted sequencing panel: Emphasis on small biopsy and cytology.

BACKGROUND: Next-generation sequencing (NGS) with a multi-gene panel is now available for patients with lung adenocarcinoma, but the performance characteristics and clinical utility of this testing are not well-described. We present the results of an extended 467 gene panel in a series of advanced, highly selected nonsmall cell lung cancer (NSCLC) patients using a range of specimens, including predominantly small biopsy and cytology specimens. MATERIALS AND METHODS: A retrospective review of 22 NSCLC biopsies sent for NGS using an extended gene panel from January 2014 to July 2015. The customized NGS panel sequences 467 cancer-associated genes with exonic and intronic sequences obtained from purified tumor DNA. Genomic alterations, patient characteristics, and success of testing were determined. RESULTS: The majority of samples tested were metastatic lung adenocarcinoma on final pathology. Of the 22 specimens tested, 5 (22.7%) were surgical resections and 17 (77.3%) were small biopsy and cytology specimens. Twenty-one (95%) of the specimens were adequate for full sequencing and yielded a total of 204 genomic alterations (average 8.9 per tumor), of which 17 (average 0.81 per tumor) were actionable and/or clinically relevant. Genomic alterations were found most commonly in the TP53, EGFR, EPHB1, MLL3, APC, SETD2, KRAS, DNMT3A, RB1, CDKN2A, ARID1A, EP300, KDM6B, RAD50, STK11, and BRCA2 genes. CONCLUSIONS: NGS using a comprehensive gene panel was performed successfully in 95% of all NSCLC cases in this series, including 94% small biopsy and cytology specimens and 100% surgical resections. This custom assay was performed on a range of tumor specimens and demonstrates that small specimens are able to provide a similar depth of information as larger ones. As many patients present at an advanced stage and only small specimens are obtained, the information these provide has the potential for guiding treatment in highly selected patients with advanced lung adenocarcinoma.

A novel role of the N terminus of budding yeast histone H3 variant Cse4 in ubiquitin-mediated proteolysis.

Regulating levels of centromeric histone H3 (CenH3) variant is crucial for genome stability. Interaction of Psh1, an E3 ligase, with the C terminus of Cse4 has been shown to contribute to its proteolysis. Here, we demonstrate a role for ubiquitination of the N terminus of Cse4 in regulating Cse4 proteolysis for faithful chromosome segregation and a role for Doa1 in ubiquitination of Cse4.