Etiology-independent activation of the LTß-LTßR-RELB axis drives aggressiveness and predicts poor prognosis in HCC.

BACKGROUND AND AIMS: HCC is the most common primary liver tumor, with an increasing incidence worldwide. HCC is a heterogeneous malignancy and usually develops in a chronically injured liver. The NF-κB signaling network consists of a canonical and a noncanonical branch. Activation of canonical NF-κB in HCC is documented. However, a functional and clinically relevant role of noncanonical NF-κB and its downstream effectors is not established. APPROACH AND RESULTS: Four human HCC cohorts (total n = 1462) and 4 mouse HCC models were assessed for expression and localization of NF-κB signaling components and activating ligands. In vitro , NF-κB signaling, proliferation, and cell death were measured, proving a pro-proliferative role of v-rel avian reticuloendotheliosis viral oncogene homolog B (RELB) activated by means of NF-κB-inducing kinase. In vivo , lymphotoxin beta was identified as the predominant inducer of RELB activation. Importantly, hepatocyte-specific RELB knockout in a murine HCC model led to a lower incidence compared to controls and lower maximal tumor diameters. In silico , RELB activity and RELB-directed transcriptomics were validated on the The Cancer Genome Atlas HCC cohort using inferred protein activity and Gene Set Enrichment Analysis. In RELB-active HCC, pathways mediating proliferation were significantly activated. In contrast to v-rel avian reticuloendotheliosis viral oncogene homolog A, nuclear enrichment of noncanonical RELB expression identified patients with a poor prognosis in an etiology-independent manner. Moreover, RELB activation was associated with malignant features metastasis and recurrence. CONCLUSIONS: This study demonstrates a prognostically relevant, etiology-independent, and cross-species consistent activation of a lymphotoxin beta/LTßR/RELB axis in hepatocarcinogenesis. These observations may harbor broad implications for HCC, including possible clinical exploitation.

Longitudinal therapy monitoring of ALK-positive lung cancer by combined copy number and targeted mutation profiling of cell-free DNA.

BACKGROUND: Targeted therapies (TKI) have improved the prognosis of ALK-rearranged lung cancer (ALK+ NSCLC), but clinical courses vary widely. Early identification and molecular characterisation of treatment failure have key importance for subsequent therapies. We performed copy number variation (CNV) profiling and targeted panel sequencing from cell-free DNA (cfDNA) to monitor ALK+ NSCLC. METHODS: 271 longitudinal plasma DNA samples from 73 patients with TKI-treated metastatic ALK+ NSCLC were analysed by capture-based targeted (average coverage 4,100x), and shallow whole genome sequencing (sWGS, 0.5x). Mutations were called using standard algorithms. CNVs were quantified using the trimmed median absolute deviation from copy number neutrality (t-MAD). FINDINGS: cfDNA mutations were identified in 58% of patients. They included several potentially actionable alterations, e.g. in the genes BRAF, ERBB2, and KIT. sWGS detected CNVs in 18% of samples, compared to 6% using targeted sequencing. Several of the CNVs included potentially druggable targets, such as regions harboring EGFR, ERBB2, and MET. Circulating tumour DNA (ctDNA) mutations and t-MAD scores increased during treatment, correlated with markers of higher molecular risk, such as the EML4-ALK variant 3 and/or TP53 mutations, and were associated with shorter patient survival. Importantly, t-MAD scores reflected the tumour remission status in serial samples similar to mutant ctDNA allele frequencies, and increased with disease progression in 79% (34/43) of cases, including those without detectable single nucleotide variant (SNV). INTERPRETATION: Combined copy number and targeted mutation profiling could improve monitoring of ALK+ NSCLC. Potential advantages include the identification of treatment failure, in particular for patients without detectable mutations, and broader detection of genomic changes acquired during therapy, especially in later treatment lines and in high-risk patients. FUNDING: This work was supported by the German Center for Lung Research (DZL), by the German Cancer Consortium (DKTK), by the Heidelberg Center for Personalized Oncology at the German Cancer Research Center (DKFZ-HIPO), and by Roche Sequencing Solutions (Pleasanton, CA, USA).

Serial liquid biopsies for detection of treatment failure and profiling of resistance mechanisms in KLC1-ALK-rearranged lung cancer.

Genetic rearrangements involving the anaplastic lymphoma kinase (ALK) gene confer sensitivity to ALK tyrosine kinase inhibitors (TKIs) and superior outcome in non-small-cell lung cancer (NSCLC). However, clinical courses vary widely, and recent studies suggest that molecular profiling of ALK+ NSCLC can provide additional predictors of therapy response that could assist further individualization of patient management. As repeated tissue biopsies often pose technical difficulties and significant procedural risk, analysis of tumor constituents circulating in the blood, including ctDNA and various proteins, is increasingly recognized as an alternative method of tumor sampling ("liquid biopsy"). Here, we report the case of a KLC1-ALK-rearranged NSCLC patient responding to crizotinib treatment and demonstrate how analysis of plasma and serum biomarkers can be used to identify the ALK fusion partner and monitor therapy over time. Results of ctDNA sequencing and copy-number alteration profiling as well as serum protein concentrations at various time points during therapy reflected the current remission status and could predict the subsequent clinical course. At the time of disease progression, we identified four distinct secondary mutations in the ALK gene in ctDNA potentially causing treatment failure, accompanied by rising levels of CEA and CYFRA 21-1. Moreover, several copy-number variations were detected at the end of the treatment, including an amplification of a region on Chromosome 12 encompassing the TP53 regulator MDM2 In summary, our findings illustrate the utility of noninvasive longitudinal molecular profiling for assessing remission status, exploring mechanisms of treatment failure, predicting subsequent clinical course, and dissecting dynamics of drug-resistant clones in ALK+ lung cancer.