Timp3 deficiency affects the progression of DEN-related hepatocellular carcinoma during diet-induced obesity in mice
Obesity and low-grade inflammation are associated with an increased risk of hepatocellular carcinoma (HCC), a leading cause of cancer-related death worldwide. The tissue inhibitor of metalloproteinase (TIMP) 3, an endogenous inhibitor of protease activity that represents a key mediator of inflammation, is reduced in inflammatory metabolic disorders and cancer. In contrast, Timp3-deficient mice (Timp3−/−) are highly resistant to developing HCC in response to a diethylnitrosamine (DEN); therefore, we aimed to elucidate the biological role of genetic loss of Timp3 in obesity-related hepatocarcinogenesis.
Fourteen-day-old male wild-type (wt) and Timp3−/− mice were injected with 25 mg/kg DEN or an equal volume of saline. After 4 weeks, mice were randomized into two dietary groups and fed either normal or high-fat diet and allowed to grow until 32 weeks of age. Liver histological features were analyzed, and differentially expressed genes in the liver were quantified.
In Timp3−/− mice fed with the obesogenic diet, despite the increase in liver steatosis and inflammation, both the number of tumors and the total tumor size are significantly reduced 30 weeks post-DEN injection, compared to control mice. Moreover, Timp3 deletion in hepatocarcinogenesis during obesity is associated with a reduction in FoxM1 transcriptional activity through H19/miR-675/p53 pathway.
This study suggests that Timp3 ablation leads to cell cycle perturbation, at least in part by repressing FoxM1 transcriptional activity through H19/miR-675/p53 pathway.
KeywordsHepatocellular carcinoma Obesity TIMP3 Inflammation
This manuscript was in part funded by Associazione Italiana per la Ricerca sul Cancro (Grant AIRC IG-13163), MIUR PRIN 2015MPESJS_004 and Fondazione Roma NCD 2014 to M.F., Fondazione Roma NCD 2014 and EFSD/Boehringer Ingelheim 2017 to R.M. Horizon 2020 (Grant MADIA 732678), MoDiag Grant and Regione Lazio, Bando Life 2014–2020 to M.D. and I.A.
Compliance with ethical standards
The handling of mice and experimental procedures were conducted in accordance with experimental animal guidelines. Animal studies were approved by the University of Tor Vergata Animal Care and Use Committee.
Conflict of interest
The authors declare that they have no conflict of interest.
For this type of study informed consent is not required.
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