👤 Mark Travis

Hepatoid lung carcinomas, similar to hepatoid carcinomas of other sites, are defined as extrahepatic tumors exhibiting divergent hepatocellular differentiation. Uniquely, hepatoid carcinomas of lung origin are reported to commonly express only hepatocyte paraffin 1 (HepPar1)-a hepatocellular marker, which recognizes mitochondrial enzyme carbamoyl-phosphate synthetase-1 (CPS1). Recently, HepPar1/CPS1 was found to accumulate in lung adenocarcinomas (LUADs) harboring STK11mutations, presumably as a genotype-associated metabolic adaptation. The impact of these insights on the concept of hepatoid lung carcinoma has not been explored. Here, we performed a detailed clinicopathologic and genomic analysis of carcinomas prospectively regarded as hepatoid with isolated HepPar1 expression (n = 17). We found that although robustly positive for HepPar1, these tumors were entirely negative for an extended panel of other hepatocellular markers (alpha-fetoprotein, Arginase1, Glypican3, and albumin-in situ hybridization). Morphologically, tumors exhibited solid-trabecular architecture with expanded granular-vacuolated-clear cytoplasm, thus evoking hepatoid morphology; however, focal-to-moderate intracytoplasmic mucin was consistently present, and hepatoid resemblance was variable. Pneumocytic markers (TTF1 and Napsin A) were entirely negative (except for cytoplasmic TTF1), commonly leading to diagnostic challenges at metastatic sites. Remarkably, next-generation sequencing revealed invariable STK11 mutations/loss (P < .00001 vs unselected LUAD, n > 2.5K). Patient survival was dismal (median, 5.8 vs 25 months for stage-matched LUAD, P = .0002). Tumors harbored high mitochondrial content by electron microscopy and other methods. For comparison, we reviewed conventional, predominantly acinar LUAD with HepPar1 expression (n = 22) and found that they also lacked any other hepatocellular markers, had invariable STK11 mutations/loss, increased granular cytoplasm, lower TTF1, and poor prognosis. We conclude that isolated HepPar1 expression in LUAD reflects mitochondrial adaptation to STK11 mutations rather than bona fide hepatocellular differentiation, and that HepPar1-expressing solid and granular adenocarcinomas represent an undifferentiated (solid, TTF1 negative) variant in this spectrum of tumors. Recognition of these tumors is warranted due to their exceptionally aggressive behavior, distinct pathogenomic features, and common association with diagnostic challenges. Show less

Childhood cancer survivors (CCS) exhibit significantly increased chronic diseases and premature death. Abnormalities in DNA methylation are associated with development of chronic diseases and reduced life expectancy. We investigated the hypothesis that anti-cancer treatments are associated with long-term DNA methylation changes that could be key drivers of adverse late health effects. Genome-wide DNA methylation was assessed using MethylationEPIC arrays in paired samples (before/after therapy) from 32 childhood cancer patients. Separately, methylation was determined in 32 samples from different adult CCS (mean 22-years post-diagnosis) and compared with cancer-free controls (n = 284). Widespread DNA methylation changes were identified post-treatment in childhood cancer patients, including 146 differentially methylated regions (DMRs), which were consistently altered in the 32 post-treatment samples. Analysis of adult CCS identified matching methylation changes at 107/146 of the DMRs, suggesting potential long-term retention of post-therapy changes. Adult survivors also exhibited epigenetic age acceleration, independent of DMR methylation. Furthermore, altered methylation at the DUSP6 DMR was significantly associated with early mortality, suggesting altered methylation may be prognostic for some late adverse health effects in CCS. These novel methylation changes could serve as biomarkers for assessing normal cell toxicity in ongoing treatments and predicting long-term health outcomes in CCS. Show less

Cisplatin is a first-line chemotherapeutic for many cancers, but causes neurotoxicity including hearing loss, tinnitus, and peripheral sensory neuropathy. However, no study has comprehensively characterized risk factors for developing multiple (>1) severe neurotoxicities. The relationship between multiple severe neurotoxicities and age, cumulative cisplatin dose, medical history, and lifestyle/behavioral factors was evaluated in 300 cisplatin-treated testicular cancer survivors using logistic regression. Case-control genome-wide association study (GWAS; cases, Age at clinical examination ( Certain survivors are more susceptible to cisplatin-induced neurotoxicity, markedly increasing likelihood of developing numerous neuro-otological symptoms that affect quality of life. Genome-wide analysis identified genetic variation in Show less

Spectraplakins are large actin-microtubule linker molecules implicated in various processes, including gastrulation, wound healing, skin blistering and neuronal degeneration. Expression data for the mammalian spectraplakin ACF7 and genetic analyses of the Drosophila spectraplakin Short stop (Shot) suggest an important role during neurogenesis. Using three parallel neuronal culture systems we demonstrate that, like Shot, ACF7 is essential for axon extension and describe, for the first time, their subcellular functions during axonal growth. Firstly, both ACF7 and Shot regulate the organisation of neuronal microtubules, a role dependent on both the F-actin- and microtubule-binding domains. This role in microtubule organisation is probably the key mechanism underlying the roles of Shot and ACF7 in growth cone advance. Secondly, we found a novel role for ACF7 and Shot in regulating the actin cytoskeleton through their ability to control the formation of filopodia. This function in F-actin regulation requires EF-hand motifs and interaction with the translational regulator Krasavietz/eIF5C, indicating that the underlying mechanisms are completely different from those used to control microtubules. Our data provide the basis for the first mechanistic explanation for the role of Shot and ACF7 in the developing nervous system and demonstrate their ability to coordinate the organisation of both actin and microtubule networks during axonal growth. Show less