Anti-STK11 (C-terminal) polyclonal antibody

Objectives: KRAS mutations are one of the most prevalent alterations in non-small cell lung cancer. However, patients with this driver alteration present heterogeneous clinical outcomes. In this study, we have explored the potential clinical impact of coexisting alterations in this subset of patients. Materials and methods: Samples from a cohort of 69 lung adenocarcinoma patients homogenously treated with platinum doublet as first-line therapy were evaluated using targeted next generation sequencing (NGS). Mutations and copy number alterations were assessed in 37 advanced KRAS-mutant (KRASm) and in 32 KRAS wild-type (KRASwt). Results: TP53 was the most frequent additional alteration found in both cohorts. Interestingly, TP53 mutations were more frequent in KRASwt than in KRASm patients (80 % vs. 34 %; p < 0.05) as well as STK11 mutations (17 % vs 8 %, p = NS). FGFR3 mutations were only found concomitantly with KRASm (11 %). No genomic co-alteration had an impact on overall survival within the KRASm patients treated with chemotherapy. Conclusions: KRAS mutated lung adenocarcinoma is a heterogeneous entity and comprehensive characterization of co-alterations using NGS may lead to more accurate patient stratification.

Background: Phosphatase and tensin homolog (PTEN) is one of the most frequently inactivated tumor suppressors in breast cancer. While PTEN itself is not considered a druggable target, PTEN synthetic-sick or synthetic-lethal (PTEN-SSL) genes are potential drug targets in PTEN-deficient breast cancers. Therefore, with the aim of identifying potential targets for precision breast cancer therapy, we sought to discover PTEN-SSL genes present in a broad spectrum of breast cancers. Methods: To discover broad-spectrum PTEN-SSL genes in breast cancer, we used a multi-step approach that started with (1) a genome-wide short interfering RNA (siRNA) screen of similar to 21,000 genes in a pair of isogenic human mammary epithelial cell lines, followed by (2) a short hairpin RNA (shRNA) screen of similar to 1200 genes focused on hits from the first screen in a panel of 11 breast cancer cell lines; we then determined reproducibility of hits by (3) identification of overlaps between our results and reanalyzed data from 3 independent gene-essentiality screens, and finally, for selected candidate PTEN-SSL genes we (4) confirmed PTEN-SSL activity using either drug sensitivity experiments in a panel of 19 cell lines or mutual exclusivity analysis of publicly available pan-cancer somatic mutation data. Results: The screens (steps 1 and 2) and the reproducibility analysis (step 3) identified six candidate broad-spectrum PTEN-SSL genes (PIK3CB, ADAMTS20, AP1M2, HMMR, STK11, and NUAK1). PIK3CB was previously identified as PTEN-SSL, while the other five genes represent novel PTEN-SSL candidates. Confirmation studies (step 4) provided additional evidence that NUAK1 and STK11 have PTEN-SSL patterns of activity. Consistent with PTEN-SSL status, inhibition of the NUAK1 protein kinase by the small molecule drug HTH-01-015 selectively impaired viability in multiple PTEN-deficient breast cancer cell lines, while mutations affecting STK11 and PTEN were largely mutually exclusive across large pan-cancer data sets. Conclusions: Six genes showed PTEN-SSL patterns of activity in a large proportion of PTEN-deficient breast cancer cell lines and are potential specific vulnerabilities in PTEN-deficient breast cancer. Furthermore, the NUAK1 PTEN-SSL vulnerability identified by RNA interference techniques can be recapitulated and exploited using the small molecule kinase inhibitor HTH-01-015. Thus, NUAK1 inhibition may be an effective strategy for precision treatment of PTEN-deficient breast tumors.