Growth arrest DNA damage-inducible gene 45 gamma expression as a prognostic and predictive biomarker in hepatocellular carcinoma

Abstract

Growth arrest DNA damage-inducible gene 45 (GADD45) family proteins play a crucial role in regulating cellular stress responses and apoptosis. The present study explored the prognostic and predictive role of GADD45γ in hepatocellular carcinoma (HCC) treatment. GADD45γ expression in HCC cells was examined using quantitative reverse transcription-PCR (qRT-PCR) and Western blotting. The control of GADD45γ transcription was examined using a luciferase reporter assay and chromatin immunoprecipitation. The in vivo induction of GADD45γ was performed using adenoviral transfer. The expression of GADD45γ in HCC tumor tissues from patients who had undergone curative resection was measured using qRT-PCR. Sorafenib induced expression of GADD45γ mRNA and protein, independent of its RAF kinase inhibitor activity. GADD45γ induction was more prominent in sorafenib-sensitive HCC cells (Huh-7 and HepG2, IC50 6–7 μM) than in sorafenib-resistant HCC cells (Hep3B, Huh-7R, and HepG2R, IC50 12–15 μM). Overexpression of GADD45γ reversed sorafenib resistance in vitro and in vivo, whereas GADD45γ expression knockdown by using siRNA partially abrogated the proapoptotic effects of sorafenib on sorafenib-sensitive cells. Overexpression of survivin in HCC cells abolished the antitumor enhancement between GADD45γ overexpression and sorafenib treatment, suggesting that survivin is a crucial mediator of antitumor effects of GADD45γ. GADD45γ expression decreased in tumors from patients with HCC who had undergone curative surgery, and low GADD45γ expression was an independent prognostic factor for poor survival, in addition to old age and vascular invasion. The preceding data indicate that GADD45γ suppression is a poor prognostic factor in patients with HCC and may help predict sorafenib efficacy in HCC.

Antiangiogenic and antihepatocellular carcinoma activities of the Juniperus chinensis extract

“…Hep3B cells also have been reported to show lower sensitivity to curcumin and sorafinib when compared with other HCC cells [ 26 , 27 ]. Checkpoint kinase 1 (Chk1) and growth arrest DNA damage-inducible gene 45 gamma (GADD45γ) have been reported to play roles in this phenomenon respectively [ 26 , 27 ]. However, because these HCC cell lines inherit different gene heterogeneity, why Hep3B cells had the lowest sensitivity to CBT-143-S-F6F7 may be complicated.…”

Cyclin E1 Inhibition can Overcome Sorafenib Resistance in Hepatocellular Carcinoma Cells Through Mcl-1 Suppression

“…Cell viability, cell cycle, and apoptosis assays Cell viability was assessed using an MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay The cell-cycle distribution and fraction of apoptotic cells after drug treatment was assessed using flow cytometry, as previously described (7). The expression of apoptosis-related proteins after drug treatment was measured using Western blotting and the Human Apoptosis Array kit (Proteome Profiler, R&D Systems).…”

“…Sorafenib has been found to exert many "offtarget effects" that may contribute to its antitumor efficacy, in addition to the inhibition of Raf kinase signaling and tumor angiogenesis (3,4). Multiple mediators in the apoptosis regulatory pathways, including Mcl-1 and survivin, may regulate the antitumor efficacy of sorafenib in cancer cells (5)(6)(7). Identifying these pathways and molecules will greatly contribute to design strategies for overcoming sorafenib resistance (8).…”

Gamma Radiation Induced Intestinal Proteomic Modulation in Mice: A Two Dimensional Electrophoretic Analysis

“…Growth arrest and DNA-damage-inducible 45 gamma, isoform CRA_a is protein product of GADD45 or growth arrest and DNA-damage-inducible gene family. These are known to play a crucial role in regulating cellular stress responses and apoptosis 25 . The studies have reported that cancer cells repress this gene to escape cell death thereby indicating that proteins of this family promote cell death during stress conditions 26 .…”