Through the last decade, cold atmospheric plasma (CAP) has emerged as an innovative therapeutic option for cancer treatment. Recently, we have set up a potentially safe atmospheric pressure plasma jet device that displays antitumoral properties in a preclinical model of cholangiocarcinoma (CCA), a rare and very aggressive cancer emerging from the biliary tree with few efficient treatments. In the present study, we aimed at deciphering the molecular mechanisms underlying the antitumor effects of CAP towards CCA in both an in vivo and in vitro context. In vivo, using subcutaneous xenografts into immunocompromised mice, CAP treatment of CCA induced DNA lesions and tumor cell apoptosis, as evaluated by 8-oxoguanine and cleaved caspase-3 immunohistochemistry, respectively. The analysis of the tumor microenvironment showed changes in markers related to macrophage polarization. In vitro, the incubation of CCA cells with CAP-treated culture media (i.e., plasma-activated media, PAM) led to a dose response decrease in cell survival. At molecular level, CAP treatment induced double-strand DNA breaks, followed by an increased phosphorylation and activation of the cell cycle master regulators CHK1 and p53, leading to cell cycle arrest and cell death by apoptosis. In conclusion, CAP is a novel therapeutic option to consider for CCA in the future.

The heregulin-1ß/HER3-driven pathway is implicated in several epithelial malignancies and its blockade is currently undergoing clinical investigation. Paradoxically, the status and the regulation of this pathway is poorly known in hepatocellular carcinoma (HCC). Using 85 HCC obtained after tumour resection, heregulin-1ß and HER3 expression was evaluated by real-time RT-PCR, ELISA and/or immunohistochemistry. Statistics were performed to analyze associations between gene expression and clinicopathological parameters. The effects of insulin on the heregulin-1ß/HER3 pathway was investigated in four HCC cell lines. HER3 mRNA was upregulated in 52 % of tumours, while heregulin-1ß mRNA was downregulated in 82 %. Hepatitis B and C viral infections were respectively associated with high and low HER3 mRNA expression. No association was seen between neither HER3 or heregulin-1ß mRNA and prognostic factors, survival or recurrence. Immunohistochemistry showed predominant cytoplasmic staining of HER3 in tumours but the staining was nonreproducible. HER3 mRNA and protein levels were not correlated in liver tissues. In HCC cells, insulin promoted HER3 proteasomal degradation and inhibited heregulin-1ß stimulation of cell migration. HER3 and insulin receptor co-immunoprecipitated in these cells. The loss of insulin receptor expression by RNA interference sensitized cells to heregulin-1ß-induced AKT phosphorylation. Autocrine heregulin-1ß loop is uncommon in HCC and HER3 mRNA expression is differentially influenced by hepatitis viruses. Insulin is a negative regulator of HER3 protein expression and function in HCC cells. Altogether these data may explain why HER3 and heregulin-1ß expression have no prognostic value and suggest that HCC patients are unlikely to derive benefit from HER3-targeted monotherapies.

Adipose tissue is far more than a passive reservoir for surplus energy: it is an active metabolic and endocrine organ that senses nutrient availability and orchestrates systemic energy balance. When caloric intake chronically exceeds expenditure, adipocytes become engorged with lipids and exposed to metabolic, mechanical, and hypoxic stress. To adapt, they initiate a fibro-inflammatory response that may be protective in the short term. As this response becomes chronic, adipocytes lose their metabolic flexibility, acquire a maladaptive fibro-inflammatory phenotype, and contribute to the cascade of inflammation, insulin resistance, and metabolic disease that characterizes obesity. In this review, we dissect the cellular and molecular cues that trigger fibro-inflammation, from nutrient excess and mitochondrial stress to hypoxia and immunometabolic rewiring, and highlight how these processes reshape adipocyte identity and tissue homeostasis.