Senolytic Cocktail Dasatinib+Quercetin (D+Q) Does Not Enhance the Efficacy of Senescence-Inducing Chemotherapy in Liver Cancer.

Kristina Kovacovicova,Illar Pata,Pille Pata,Jiri Bartek,Marianna Skolnaja,Manlio Vinciguerra,Mihkel Heinmaa,Martin Mistrik

doi:10.3389/fonc.2018.00459

Abstract

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death, which develops in the context of fibrosis and cirrhosis caused by chronic inflammation, in turn due to non-alcoholic fatty liver disease (NAFLD), alcohol consumption and/or hepatitis viral infection. An increased number of senescent cells are associated with age-related tissue degeneration during NAFLD-induced HCC, or during chemotherapeutic treatment. Senolytic agents target selectively senescent cells. A combination of the senolytic drugs dasatinib and quercetin (D+Q) reduced hepatic lipid accumulation and alleviated age-associated physical dysfunction in mice. However, whether D+Q can impact the treatment of HCC, at the end-stage of the NAFLD inflammatory spectrum, is unknown. Here, using two well-established HCC cell lines (HepG2, Huh-7), we demonstrate that the maximal cytostatic doses for D and/or Q (1 + 1 μM) lacked efficacy in removing doxorubicin-induced β-gal-positive senescent cells. Moreover, D+Q did not affect doxorubicin-dependent induction of flattened morphology, activation of p16, expression of SASP-associated genes or formation of γH2AX foci. We then investigated the antitumor efficacy of doxorubicin, D+Q, or the combination, in xenograft studies conducted with HCC cells inoculated in athymic nude mice. Doxorubicin reduced tumor growth by 30% compared to control mice, while D+Q was ineffective in synergizing with doxorubicin and in clearing doxorubicin-induced HCC senescent cells. Unexpectedly, D+Q alone appeared to have acute pro-tumorigenic effects in control mice. While our data need to be confirmed in animal models that fully recapitulate NAFLD, we demonstrate that these compounds are ineffective, alone or in synergy with senescence-inducing chemotherapy, against experimental HCC.

Highlights

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death in the world [1]
DOX was washed out after 24 h and cells were incubated in normal medium for seven additional days, before analyses; [3] dasatinib and quercetin (D+Q), cells were treated with 1 μM D + 1 μM Q for 24 h; [4] D+Q, DOX; cells were treated with 100 nM doxorubicin for 24 h
Four experimental groups of balb/c nude mice (n = 11 per group) implanted with Huh-7-eqFP650 were created as it follows: [1] CTL, control mice i.p. injected with vehicle alone (PBS); [2] DOX, mice injected with 4 mg/kg doxorubicin at days 7 and 14 postimplantation; [3] D+Q, mice administered with Dasatinib (D, 5 mg/kg) + Quercetin (Q, 50 mg/kg) by oral gavage, at days 9 and 16 post-implantation; [4] D+Q + DOX, mice injected with 4 mg/kg doxorubicin at days 7 and 14 post-implantation, and simultaneously administered with D+Q by oral gavage, at days 9 and 16 post-implantation (Figure 2A)

Summary

Introduction

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death in the world [1]. An increased number of senescent cells is associated to age-related tissue degeneration during NAFLD-induced HCC [7, 8]. Doxorubicin was washed out after 24 h and cells were incubated in normal medium for six additional days, before treatment with D+Q for additional 24 h (Figure 1A).

Results

Conclusion