Induction of p53-dependent p21 limits proliferative activity of rat hepatocytes in the presence of hepatocyte growth factor.

BACKGROUND: Hepatocyte growth factor (HGF), a potent mitogen for hepatocytes, enhances hepatocyte function without stimulating proliferation, depending on the physiological conditions. p53, a transcription factor, suppresses the cell proliferation by expressing p21(WAF1/CIP1) in various tissues. AIM: To investigate the mechanism through which the hepatocytes maintain mitotically quiescent even in the presence of HGF. METHODS: We studied the relationship between p53 and p21 expression and the effect of p53-p21 axis on hepatocyte proliferation in primary cultured rat hepatocytes stimulated by HGF. Hepatic p21 levels are determined serially after partial hepatectomy or sham operation in rats. RESULTS: DNA synthesis was markedly increased by HGF addition in rat hepatocytes cultured at low density but not at high density. Cellular p53 levels increased in the hepatocytes cultured at both the densities. p21 levels were increased and correlated with cellular p53 levels in hepatocytes cultured at high density but not at low density. When the activity of p53 was suppressed by a chemical inhibitor for p53, cellular p21 levels were reduced, and DNA synthesis was increased. Similarly, p21 antisense oligonucleotide increased the DNA synthesis. In rats after partial hepatectomy, transient elevation of hepatic p21 levels was observed. In contrast, in sham-operated rats, hepatic p21 levels were increased on sustained time scales. CONCLUSION: p53-related induction of p21 may suppress hepatocyte proliferation in the presence of HGF in the setting that mitogenic activity of HGF is not elicitable

Therapeutic efficacy of lenvatinib for patients with unresectable hepatocellular carcinoma based on the middle-term outcome.

AIM:This study sought to clarify the usefulness of lenvatinib for patients with unresectable hepatocellular carcinoma (HCC). METHODS:The subjects were 69 patients with HCC receiving lenvatinib; the median age was 73 years, and 14 and 67 patients had been previously treated with regorafenib and/or sorafenib and therapies without molecular-targeted agents, respectively. Therapeutic efficacy was evaluated using contrast-enhanced CT images obtained 4-8 weeks after the start of lenvatinib and the middle-term outcome using Kaplan-Meier method. RESULTS:The baseline Child-Pugh scores were 5, 6 and 7 in 31, 32 and 6 patients, respectively, and the modified albumin-bilirubin (mALBI) grades were 1, 2a and 2b in 20, 20 and 29 patients, respectively. The Barcelona Clinic Liver Cancer (BCLC) stages following downsizing after prior treatment were A, B and C in 17, 22 and 30 patients, respectively. The therapeutic efficacy was evaluated in 54 patients, and the percentages of patients achieving CR, PR, SD and PD were 3.7%, 44.4%, 37.0%, and 14.8%, respectively. The ALBI scores deteriorated significantly between 4 and 12 weeks after the start of therapy, compared with the baseline. The cumulative survival rates at 48 weeks were significantly higher among patients achieving CR/PR (95.5%) than among those showing no response (54.3%). Multivariate analyses revealed that the BCLC stages and the serum AFP levels were significantly associated with therapeutic efficacy, while the mALBI grade was associated with the middle-term outcome. CONCLUSIONS:A favorable middle-term outcome was obtained in patients with HCC receiving lenvatinib, especially in those manifesting grades 1/2a mALBI at baseline, despite the deterioration in ALBI scores during treatment

Cellular p53 and p21 levels in hepatocytes treated with HGF.

<p>Rat hepatocytes were cultured in WE containing 10% FCS and various concentrations of HGF for 18 hours. Open circles denote hepatocytes cultured in the absence of HGF. Dotted open circles denote hepatocytes cultured with 2.5 ng/mL HGF. Dotted closed circles denote hepatocytes cultured with 5 ng/mL HGF. Closed circles denote hepatocytes cultured with 10 ng/mL HGF. (A) Hepatocytes cultured at high density. (B) Hepatocytes cultured at low density.</p

Changes in DNA synthesis of hepatocytes after HGF treatment.

<p>Rat hepatocytes were cultured in WE containing 10% FCS, 10 ng/mL HGF and 0.1 mmol/L BrdU, and were harvested serially. Closed circles denote hepatocytes cultured at high density. Open circles denote hepatocytes cultured at low density. Data are mean ± SEM of eight dishes. *p<0.01 compared with the values cultured for 0 hours.</p

Serum asunaprevir concentrations showing correlation with the extent of liver fibrosis as a factor inducing liver injuries in patients with genotype-1b hepatitis C virus receiving daclatasvir plus asunaprevir therapy.

AIMS:Liver injury can occur during antiviral therapies with direct-acting antivirals (DAAs), potentially necessitating discontinuation of the therapies, with consequent worsening of the sustained viral response (SVR) rates, in patients with hepatitis C virus (HCV). To clarify the mechanisms involved in serum transaminase level elevation, we performed a retrospective evaluation of the serum concentrations of daclatasvir and asunaprevir, both classified as DAAs, in patients receiving treatment with a combination of the two drugs. METHODS:Subjects were 278 Japanese patients with genotype-1b HCV who received daclatasvir plus asunaprevir therapy for more than 4 weeks. Serum concentrations of both the DAAs were measured at 4 weeks after the initiation of therapy. RESULT:Liver injuries including serum AST and/or ALT level elevation to 150 U/L or over were found in 34 patients (12.2%). Multivariate logistic regression analysis identified serum asunaprevir concentrations as being significantly associated with developing liver injury, with an odds ratio of 1.046 (95% confidence interval 1.011-1.082, p<0.05). Serum asunaprevir concentrations showed correlation with the extent of liver fibrosis, estimated by peripheral platelets counts and serum albumin levels and baseline and FIB4 index and serum Mac-2 binding protein glycosylation isomer (M2BPGi) levels at 4 weeks of the therapy; the concentrations were significantly higher among patients showing 3.0 or more of M2BPGi levels than among those with the levels less than 3.0; on the other hand, no such correlation/difference was found in serum daclatasvir concentrations. CONCLUSION:High serum concentrations of serum asunaprevir, which were associated with the extent of liver fibrosis, appear to provoke the occurrence of liver injury in patients with genotype-1b HCV receiving combined daclatasvir plus asunaprevir therapy

Cellular p53 levels in hepatocytes treated with HGF.

<p>Rat hepatocytes were cultured in WE containing 10% FCS and various concentration of HGF for 18 hours. Closed bars denote hepatocytes cultured at high density. Open bars denote hepatocytes cultured at low density. Data are mean ± SEM of four dishes. *p<0.01 compared with the values in the absence of HGF.</p

The effect of pifithrin-α on DNA synthesis of hepatocytes in the presence of HGF.

<p>Rat hepatocytes were cultured at high density in the same medium as described in the legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0078346#pone-0078346-g006" target="_blank">Figure 6</a>, except that the medium contained 1 mmol/L BrdU, for 24 hours. An open bar denotes hepatocytes cultured in the absence of HGF. Closed bars denote hepatocytes cultured with pifithrin-α in the presence of 10 ng/mL HGF. A dotted bar denotes hepatocytes cultured with DMSO in the presence of 10 ng/mL HGF. Data are mean ± SEM of eight dishes. *p<0.01 compared with the values treated only with HGF or values treated with HGF and DMSO.</p