Growth inhibitory effects of pegylated IFN alpha-2b on human liver cancer cells in vitro and in vivo

Anti-PD-L1 antibodies promote cellular proliferation by activating the PD-L1-AXL signal relay in liver cancer cells

BACKGROUND

Immune checkpoint inhibitors (ICIs) are emerging treatments for advanced hepatocellular carcinoma (HCC); however, evidence has shown they may induce hyperprogressive disease via unexplained mechanisms.

METHODS

In this study, we investigated the possible stimulative effect of ICIs on programmed cell death-ligand 1 (PD-L1)-harboring liver cancer cells under immunocompetent cell-free conditions.

RESULTS

The sarcomatous HAK-5 cell line displayed the highest expression of PD-L1 among 11 human liver cancer cell lines used in this study. HLF showed moderate expression, while HepG2, Hep3B, and HuH-7 did not show any. Moreover, sarcomatous HCC tissues expressed high levels of PD-L1. We observed approximately 20% increase in cell proliferation in HAK-5 cells treated with anti-PD-L1 antibodies, such as durvalumab and atezolizumab, for 48 h compared with that of those treated with the control IgG and the anti-PD-1 antibody pembrolizumab. No response to durvalumab or atezolizumab was shown in PD-L1-nonexpressing cells. Loss-of-function and gain-of-function experiments for PD-L1 in HAK-5 and HepG2 cells resulted in a significant decrease and increase in cell proliferation, respectively. Phosphorylated receptor tyrosine kinase array and immunoprecipitation revealed direct interactions between PD-L1 and AXL in tumor cells. This was stabilized by extrinsic anti-PD-L1 antibodies in a glycosylated PD-L1-dependent manner. Activation of AXL, triggering signal relay to the Akt and Erk pathways, boosted tumor cell proliferation both in vitro and in xenografted tumors in NOD/SCID mice.

CONCLUSION

Collectively, this suggests that anti-PD-L1 antibodies stimulate cell proliferation via stabilization of the PD-L1-AXL complex in specific types of liver cancer, including in HCC with mesenchymal components.

SIGNIFICANCE

Therapeutic anti-PD-L1 antibodies promote cell proliferation by stabilizing the PD-L1-AXL complex in PD-L1-abundant neoplasms, including in HCC with mesenchymal components. Such a mechanism may contribute to the development of hyperprogressive disease.

Direct and indirect effects of IFN-α2b in malignancy treatment: not only an archer but also an arrow

Interferon-α2b (IFN-α2b) is a highly active cytokine that belongs to the interferon-α (IFN-α) family. IFN-α2b has beneficial antiviral, antitumour, antiparasitic and immunomodulatory activities. Direct and indirect antiproliferative effects of IFN-α2b have been found to occur via multiple pathways, mainly the JAK-STAT pathway, in certain cancers. This article reviews mechanistic studies and clinical trials on IFN-α2b. Potential regulators of the function of IFN-α2b were also reviewed, which could be utilized to relieve the poor response to IFN-α2b. IFN-α2b can function not only by enhancing the systematic immune response but also by directly killing tumour cells. Different parts of JAK-STAT pathway activated by IFN-α2b, such as interferon alpha and beta receptors (IFNARs), Janus kinases (JAKs) and IFN‐stimulated gene factor 3 (ISGF3), might serve as potential target for enhancing the pharmacological action of IFN-α2b. Despite some issues that remain to be solved, based on current evidence, IFN-α2b can inhibit disease progression and improve the survival of patients with certain types of malignant tumours. More efforts should be made to address potential adverse effects and complications.

Interferons: role in cancer therapy

Interferons (IFNs) are a group of signaling cytokines, secreted by host cells to induce protection against various disorders. IFNs can directly impact on tumor cells or indirectly induce the immune system to protect host cells. The expression levels of IFNs and its functions of are excellently modulated in a way to protect host cells from probable toxicities caused by extreme responses. The efficacy of anticancer therapies is correlated to IFNs signaling. Although IFN signaling is involved in induction of antitumor responses, chronic stimulation of the IFN signaling pathway can induce resistance to various antineoplasm therapies. Hence, IFNs are expressed by both cancer and immune cells, and modulate their biological function. Understanding this mechanism of action might be a key target of combination therapies.

Adjuvant pegylated interferon therapy improves the survival outcomes in patients with hepatitis-related hepatocellular carcinoma after curative treatment: A meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common cancers and the second leading cause of cancer-related deaths in men worldwide. Surgical resection of HCC remains the mainstay treatment procedure. As a result of hepatitis viral infection, the postoperative survival outcome in patients with HCC is not satisfactory. Recently, studies have reported that due to its treatment effect on hepatitis infection, pegylated interferon (Peg-IFN)-based therapy could improve the survival outcome after the treatment of hepatitis-related HCC. However, the postoperative effect of this regimen on the survival outcomes in patients with hepatitis-related HCC remains debatable. The present study conducted a meta-analysis to evaluate the effects of adjuvant Peg-IFN-based therapy on the survival outcomes in patients with hepatitis-related HCC after the curative treatment.

METHODS

A systematic search was conducted to identify studies on the survival outcomes in patients with hepatitis-related HCC after a curative treatment with adjuvant Peg-IFN. PubMed, EmBase, and Cochrane Library databases were searched until September 20, 2017. The retrieved studies were independently assessed by 2 reviewers, to identify the potentially eligible studies and extract data of interest. STATA software (Version 10.0, STATA Corporation, College Station, Texas) software was used for all statistical analyses.

RESULTS

The pooled results showed that adjuvant Peg-IFN-based therapy improved the 3- and 5-year recurrence-free survival (RFS) rates of patients with hepatitis-related HCC (3-year RFS, HR = 0.80; 95% CI: 0.64-0.99, P = .04; P = .81 for heterogeneity; 5-year RFS, HR = 0.82; 95% CI: 0.67-0.99, P = .04; P = .84 for heterogeneity). For the 5-year overall survival (OS) outcomes of Peg-IFN therapy for hepatitis-related HCC after the curative treatment, the pooled results showed a significant difference between the 2 groups (HR = 0.67; 95% CI: 0.47-0.97, P = .03; P = .99 for heterogeneity).

CONCLUSIONS

Adjuvant Peg-IFN-based therapy could improve the RFS and OS outcomes in patients after curative treatment of hepatitis-related HCC, with no severe adverse effects.

Immunomodulatory and antitumor effects of type I interferons and their application in cancer therapy

During the last decades, the pleiotropic antitumor functions exerted by type I interferons (IFNs) have become universally acknowledged, especially their role in mediating interactions between the tumor and the immune system. Indeed, type I IFNs are now appreciated as a critical component of dendritic cell (DC) driven T cell responses to cancer. Here we focus on IFN-α and IFN-β, and their antitumor effects, impact on immune responses and their use as therapeutic agents. IFN-α/β share many properties, including activation of the JAK-STAT signaling pathway and induction of a variety of cellular phenotypes. For example, type I IFNs drive not only the high maturation status of DCs, but also have a direct impact in cytotoxic T lymphocytes, NK cell activation, induction of tumor cell death and inhibition of angiogenesis. A variety of stimuli, including some standard cancer treatments, promote the expression of endogenous IFN-α/β, which then participates as a fundamental component of immunogenic cell death. Systemic treatment with recombinant protein has been used for the treatment of melanoma. The induction of endogenous IFN-α/β has been tested, including stimulation through pattern recognition receptors. Gene therapies involving IFN-α/β have also been described. Thus, harnessing type I IFNs as an effective tool for cancer therapy continues to be studied.

Effects of antiviral therapy for hepatitis C following treatment of hepatocellular carcinoma: survey findings of the Japanese Red Cross Liver Study Group

AIM

To investigate, in a large number of cases at multiple institutions, the effects and limitations of antiviral therapy for hepatitis C following treatment of hepatocellular carcinoma (HCC) in clinical practice.

METHODS

Retrospective analysis was performed of 112 patients who had received interferon (IFN) for treating hepatitis C following treatment of HCC and were registered with the Japanese Red Cross Liver Study Group. Factors that may influence recurrence and survival rates were investigated.

RESULTS

Factors involved in prevention of recurrence were: surgical resection as HCC treatment, platelet and α-fetoprotein (AFP) levels prior to IFN administration, IFN adherence and post-IFN AFP level. Multivariate analysis showed post-IFN AFP level to be an independent factor. Factors involved in prolonging survival were: IFN adherence, IFN response (sustained viral response), pre-IFN alanine aminotransferase and AFP levels, post-IFN AFP level and absence of recurrence. Multivariate analysis showed absence of recurrence to be an independent factor. Although IFN adherence was involved in recurrence and survival, ribavirin adherence was not. IFN was suggested to be involved in preventing recurrence and improving survival due not only to its anti-viral effect, but also its antitumor effect.

CONCLUSION

Although complete prevention of HCC recurrence is difficult, the most important factor affecting first recurrence is the AFP level at 6 months after the conclusion of antiviral treatment. The survival rate improves dramatically if the hepatitis C virus is eliminated, but the most important factor for improving survival is absence of recurrence.

Interferon-α and cyclooxygenase-2 inhibitor cooperatively mediates TRAIL-induced apoptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. Interferon-alpha (IFN-α) has recently been recognized to harbor therapeutic potential in the prevention and treatment of HCC, but it remains controversial as to whether IFN-α exerts direct cytotoxicity against HCC. Cyclooxygenase-2 (COX-2) is overexpressed in HCC and is considered to play a role in hepatocarcinogenesis. Therefore, we aimed to elucidate the combined effect of a COX-2 inhibitor, celecoxib, and IFN-α on in vitro growth suppression of HCC using the hepatoma cell line HLCZ01 and the in vivo nude mouse xenotransplantation model using HLCZ01 cells. Treatment with celecoxib and IFN-α synergistically inhibited cell proliferation in a dose- and time-dependent manner. Apoptosis was identified by 4׳,6-diamidino-2-phenylindole dihydrochloride and fluorescent staining. IFN-α upregulated the expression of TRAIL, while celecoxib increased the expression of TRAIL receptors. The combined regimen with celecoxib and IFN-α reduced the growth of xenotransplanted HCCs in nude mice. The regulation of IFN-α- and COX-2 inhibitor-induced cell death is impaired in a subset of TRAIL-resistant cells. The molecular mechanisms of HCC cells resistant to TRAIL-induced apoptosis were explored using molecular biological and immunological methods. Interferon-α and the COX-2 inhibitor celecoxib synergistically increased TRAIL-induced apoptosis in hepatocellular carcinoma. These data suggest that IFN-α and celecoxib may offer a novel role with important implications in designing new therapeutics for TRAIL-resistant tumors.

Pegylated interferon-α2a inhibits proliferation of human liver cancer cells in vitro and in vivo

Purpose

We investigated the effects of pegylated interferon-α2a (PEG-IFN-α2a) on the growth of human liver cancer cells.

Methods

The effect of PEG-IFN-α2a on the proliferation of 13 liver cancer cell lines was investigated invitro. Cells were cultured with medium containing 0–4,194 ng/mL of PEG-IFN-α2a, and after 1, 2, 3, or 4 days of culture, morphologic observation and growth assay were performed. After hepatocellular carcinoma (HCC) cells (HAK-1B and KIM-1) were transplanted into nude mice, various doses of PEG-IFN-α2a were subcutaneously administered to the mice once a week for 2 weeks, and tumor volume, weight, and histology were examined.

Results

PEG-IFN-α2a inhibited the growth of 8 and 11 cell lines in a time- and dose-dependent manner, respectively, although the 50% growth inhibitory concentrations of 7 measurable cell lines on Day 4 were relatively high and ranged from 253 ng/mL to 4,431 ng/mL. Various levels of apoptosis induction were confirmed in 8 cell lines. PEG-IFN-α2a induced a dose-dependent decrease in tumor volume and weight, and a significant increase of apoptotic cells in the tumor. Subcutaneous administration of clinical dose for chronic hepatitis C (3 μg/kg, 0.06 μg/mouse) was effective and induced about 30-50% reduction in the tumor volume and weight as compared with the control.

Conclusions

Although invitro anti-proliferative effects of PEG-IFN-α2a were relatively weak, PEG-IFN-α2a induced strong anti-tumor effects on HCC cells invivo. The data suggest potential clinical application of PEG-IFN-α2a for the prevention and treatment of HCC.

A systematic review and meta-analysis of adjuvant interferon therapy after curative treatment for patients with viral hepatitis-related hepatocellular carcinoma

The efficacy of adjuvant interferon treatment for the management of patients with viral hepatitis-related hepatocellular carcinoma (HCC) following curative treatment is controversial. We have conducted a systematic review with meta-analysis to assess the effects of adjuvant interferon therapy on survival outcomes. Randomized and nonrandomized studies (NRSs) comparing adjuvant interferon treatment with the standard of care for viral hepatitis-related HCC after curative treatment were included. CENTRAL, Medline, EMBASE and the Science Citation Index were searched with complementary manual searches. The primary outcomes were recurrence-free survival (RFS) and overall survival (OS). Nine randomized trials and 13 NRSs were included in the meta-analysis. These nine randomized trials included 942 participants, of whom, 490 were randomized to the adjuvant interferon treatment group and 452 to the control group. The results of meta-analysis showed unexplained heterogeneity for both RFS and OS. The 13 NRSs included 2214 participants, of whom, 493 were assigned to the adjuvant interferon treatment group and 1721 to the control group. The results of meta-analysis showed that, compared with controls, adjuvant interferon treatment significantly improved the RFS [hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.52-0.84, I(2) = 29%] and OS (HR 0.43, 95% CI 0.34-0.56, I(2) = 0%) of patients with hepatitis C virus-related HCC following curative treatment. There was little evidence for beneficial effects on patients with hepatitis B virus-related HCC. Future research should be aimed at clarifying whether the effects of adjuvant interferon therapy are more prominent in hepatitis C patients with sustained virological responses.

Interferon-α enhances 5'-deoxy-5-fluorouridine-induced apoptosis by ERK-dependant upregulation of thymidine phosphorylase

5-Florouracil (5-FU) is the basic agent used in the treatment of gastric cancer. Capecitabine, a prodrug of 5-FU, displays increased antitumor efficacy compared with 5-FU in the clinic. 5′-Deoxy-5-fluorouracil (5′-DFUR), the metabolite of capecitabine, is converted to 5-FU by the enzyme thymidine phosphorylase (TP), which is present at high concentrations in human tumors. In this study, we investigated the effect of interferon-α (IFN-α) on the sensitivity of gastric cancer cells to treatment with 5′-DFUR and its relationship with TP expression. Preincubation of gastric cancer cells with IFN-α enhanced 5′-DFUR-induced apoptosis via IFN-α-mediated upregulation of TP. The depletion of TP with small interfering RNA (siRNA) obviously inhibited IFN-α-induced upregulation of TP expression and thus prevented apoptosis induced by IFN-α and 5′-DFUR. Treatment with IFN-α and combined IFN-α and 5′-DFUR treatment were also associated with concomitant activation of ERK signaling. Treatment with the ERK inhibitor PD98059 or depletion of ERK with siRNA partially reversed IFN-α-induced upregulation of TP expression, thus partially preventing apoptosis induced by IFN-α and 5′-DFUR. Taken together, our study shows that IFN-α enhanced 5′-DFUR-induced apoptosis in gastric cancer cells by upregulation of TP expression, which is partially regulated by activation of ERK signaling.

Safety and efficacy of adjuvant pegylated interferon therapy for metastatic tumor antigen 1-positive hepatocellular carcinoma

BACKGROUND

Metastatic tumor antigen 1 (MTA1) overexpression is closely associated with postoperative recurrence of hepatocellular carcinoma (HCC). It has been suggested that pegylated interferon (Peg-IFN) can prevent the occurrence of HCC in patients who have chronic viral hepatitis. In this study, the authors examined whether postoperative adjuvant Peg-IFN therapy can reduce the recurrence of MTA1-positive HCC after curative surgical resection.

METHODS

In this case-control study, 93 patients with MTA1-positive HCC who underwent curative surgical resection were prospectively enrolled. The median patient age was 53 years (range, 27-78); there were 65 men and 28 women; the etiology was hepatitis B virus (HBV) in 77 patients, hepatitis C virus (HCV) in 6 patients, and non-HBV/non-HCV in 10 patients; 31 patients received Peg-IFN (Peg-INTRON) subcutaneously at a dose of 50 μg per week for 12 months (the Peg-IFN group); and the remaining 62 patients were followed only and did not receive any adjuvant therapies (control group). Patients were followed every 1 to 3 months for a median of 24 months.

RESULTS

HCC recurred postoperatively in 26 of 93 patients (28%), and 9 patients (10%) died during follow-up. The overall cumulative recurrence rates were significantly lower in the Peg-IFN group than in the control group (7% and 14% vs. 24% and 34% at 1 year and 2 years, respectively; P < .05). In addition, the 1-year and 2-year cumulative survival rates were higher in the Peg-IFN group compared with the control group (100% vs. 93% and 100% vs. 87%, respectively; P < .05). In multivariate analysis, the receipt of adjuvant Peg-IFN therapy, in addition to having a lower Cancer of the Liver Italian Program score and being a woman, was an independent, favorable factor for a lower risk of postoperative recurrence.

CONCLUSIONS

The current data indicate that adjuvant Peg-IFN therapy may reduce the recurrence of HCC in patients who have MTA1-positive HCC after curative surgical resection.

Antiproliferative effects of sorafenib and pegylated IFN‑α2b on human liver cancer cells in vitro and in vivo

Novel therapeutic strategies are needed to treat patients with advanced hepatocellular carcinoma (HCC). Combination therapy of sorafenib and type I interferon (IFN) has substantial activity in patients with metastatic renal cell carcinoma. We investigated the antiproliferative effects of sorafenib in combination with pegylated interferon-α2b (PEG-IFN-α2b) on human hepatocellular carcinoma (HCC) cells in vitro and in vivo. A poorly differentiated HCC cell line derived from a patient with hepatitis C virus infection, HAK-1B and the moderately differentiated HCC cell line KIM-1 were used in this study. We demonstrated a synergistic antiproli ferative effect of combination therapy on HAK-1B cells in vitro. In the in vivo study, a significant reduction of tumor volume and weight were observed in the combination group in both HAK-1B and KIM1 tumors, although synergistic effects were not clearly observed. The density of CD34-positive microvessels was significantly lower and cleaved caspase-3-positive apoptotic cell numbers were higher, in the sorafenib group and the combination group compared to the control or PEG-IFN-α2b group in both HAK-1B and KIM-1 tumors. Ki67 labeling index was significantly lower in the combination group compared to the control group in KIM-1 tumors. In conclusion, our results suggest that the combination therapy may be more effective for the treatment of HCC cases with variable sensitivity to antitumor effects of single therapy with either sorafenib or PEG-IFN-α2b.

Anticarcinogenic impact of interferon therapy on the progression of hepatocellular carcinoma in patients with chronic viral infection

Hepatocellular carcinoma (HCC) is mainly caused by a persistent infection due to the hepatitis B or hepatitis C virus. The number of HCC cases is increasing in Asian and African countries, as well as in European and American countries. Interferon (IFN) therapy, used for type B chronic liver diseases, inhibits hepatic carcinogenesis in patients with compensated cirrhosis. However, there is insufficient evidence that IFN therapy inhibits hepatic carcinogenesis in patients with chronic hepatitis B. There are few cases of HCC due to chronic hepatitis B, and long-term follow-up periods verifying the inhibitory effect of IFN on hepatic carcinogenesis have not been obtained. To improve the prognosis of type B chronic liver diseases, it is important that hepatitis treatment follows guidelines in which a patient's age and the extent of hepatic fibrosis are taken into account. As for chronic hepatitis C, since a sustained virological response (SVR) in IFN therapy inhibits hepatic carcinogenesis and improves prognosis, treatment that aims for an SVR while taking into consideration host-sided and virus-sided factors is recommended for patients with type C chronic liver diseases. In areas with low incidence of HCC (e.g. USA), a large number of cases and a long-term follow-up period are needed before it can be accepted that IFN therapy inhibits hepatic carcinogenesis. After locally curative treatment of HCC, IFN therapy suppresses recurrence and improves survival rates.

Adjuvant therapy after curative treatment for hepatocellular carcinoma

It is widely accepted that hepatocellular carcinoma (HCC) has an annual recurrence rate of approximately 15-20% even after potentially curative treatment, with the 5-year recurrence rate reaching 80-90%. This recurrence rate is also known to be similar after various curative treatments including resection, percutaneous ethanol injection therapy, and radiofrequency ablation. Generally, in treating patients with HCC associated with hepatitis C or liver cirrhosis, aggressive efforts to prevent secondary carcinogenesis are necessary rather than simply observing the clinical course after treatment. Presently, a combination of peg-interferon and ribavirin is known to be highly effective in patients with difficult-to-treat hepatitis C with a high viral load and genotype I virus. Therefore, indications of these treatments must be considered to prevent secondary carcinogenesis in patients with hepatitis C. Recently, long-term follow-up of low-dose, long-term maintenance therapy using pegylated interferon-α2a for cirrhotic patients clearly showed a preventive effect on HCC occurrence and recurrence. Preventing secondary carcinogenesis by suppressing inflammation employing the same treatment as that against primary carcinogenesis is also important. The molecular targeted agent sorafenib markedly suppresses the serine/threonine kinases of Raf in the MAP kinase cascade and inhibits the tyrosine kinases of angiogenesis factor receptors such as vascular endothelial growth factor and platelet-derived growth factor receptors. It thus simultaneously prevents the proliferation of tumors and inhibits angiogenesis. A clinical trial to examine the recurrence-preventing effect of sorafenib by administration of it after curative treatment such as resection or ablation is in progress (STORM trial: http://clinicaltrials.gov.com, NCT00692770). Treatments to prevent recurrence (including intrahepatic metastasis and multicentric carcinogenesis) as well as early detection and early curative treatment are extremely important to improve the prognosis of patients with HCC. Thus, further research on this issue should be carried out, especially in relation to molecular targeted therapy.

Antiviral therapy in patients after treatment for hepatitis C-related hepatocellular carcinoma

BACKGROUND/AIMS

Despite great progress, antiviral treatment for chronic hepatitis C in patients with prior hepatocellular carcinoma (HCC) has been rarely investigated. We evaluated the efficacy and safety of antiviral therapy following treatment for hepatitis C-related HCC.

METHODS

Thirteen patients (age 34 to 60 years) who were treated with peginterferon plus ribavirin after treatment for HCC were reviewed.

RESULTS

There were 6 patients with genotype 1 and 7 patients with genotype 2. All patients showed advanced fibrosis (≥F3) but belonged to the Child-Pugh class A. Treatment was stopped in 2 patients because of recurrent HCC and in 1 patient due to a lack of early virologic response. Seven patients achieved sustained virologic response and three patients relapsed. The sustained virologic response rate was 54% overall, 17% in genotype 1, and 86% in genotype 2. No significant adverse events were reported.

CONCLUSIONS

Antiviral therapy should not be excluded in patients who were previously treated with HCC with genotype 2 chronic hepatitis C, in which an efficacious antiviral treatment for chronic hepatitis C was feasible. Additional study is needed to prove the validity of antiviral therapy in patients with genotype 1 hepatitis C-related HCC.

Long-term interferon therapy after radiofrequency ablation is effective in treating patients with HCV-associated hepatocellular carcinoma

PURPOSE

This study investigates the usefulness of long-term interferon (IFN) therapy following radiofrequency ablation (RFA) for HCV-associated hepatocellular carcinoma (HCC).

METHODS

This is a retrospective observational study. Patients underwent pegylated IFN-α/ribavirin combination therapy for 48 weeks and then were maintained on IFN-α administration on average for 68 weeks (mean total duration 116 weeks). Patients who underwent IFN monotherapy were maintained on IFN administration on average for 78 weeks.

RESULTS

There were biases in the background factors between the IFN and non-IFN groups. Therefore, a covariate adjustment was performed using the propensity score. An analysis of 20-matched patients from each group showed the 5-year cumulative survival rate was higher in the IFN group than in the non-IFN group (100 and 76%, respectively), and the 3-year cumulative recurrence rate was significantly lower in the IFN group than in the non-IFN group (38.0 and 64.2%, respectively). In 14 patients (i.e., IFN responders), the serum alanine aminotransferase (ALT) level remained normalized at 30 IU/mL or lower, regardless of disappearance of serum HCV RNA. In these patients, the cumulative recurrence rate was low, the hazard ratio was 0.158 (95% confidence interval = 0.045-0.561, P = 0.004), and the serum albumin level was retained.

CONCLUSION

These results show the importance of maintaining the liver function and suggest that long-term IFN administration after RFA inhibits recurrence and contributes to an improved outcome in patients (in particular, IFN responders) who initially develop HCC.

Effects of pegylated interferon α2b on metastasis of hepatocellular carcinoma

OBJECTIVE

Interferon (IFN) has an anti-tumor activity in hepatocellular carcinoma (HCC) via anti-angiogenesis and induction of apoptosis. We have previously reported anti-metastatic effects of IFN combined chemotherapy on the outcome of HCC patients. The aim of this study was to investigate anti-metastatic effects of IFN.

METHODS

In vitro, pegylated interferon α2b (PEG-IFN-α2b) was administered to mouse MH134 cells (mouse HCC cell line, MH134), and anti-implantation effects were examined by evaluating the inhibition of cell invasion and cell proliferation. Expressions of vascular endothelial growth factor (VEGF) mRNA were also measured. In vivo, PEG-IFN-α2b was subcutaneously administered into MH134 cells and tumor growth was evaluated. In distant metastasis models, PEG-IFN-α2b was subcutaneously administered and MH134 cells were injected into the spleen. The number of liver metastases and microvessel densities (MVD) were counted.

RESULTS

In vitro, the proliferation of MH134 cells was significantly suppressed by PEG-IFN-α2b dose-dependently. MH134 cells added with PEG-IFN-α2b exhibited significantly lower levels of invasion potential. In vivo, tumor size in mice treated with PEG-IFN-α2b significantly suppressed compared with control mice (mean 0.5 versus 5.0 cm, in diameter, P < 0.05) and also decreased number of liver metastases (19.3 versus 6.0, P < 0.05). Moreover, PEG-IFN-α2b significantly suppressed angiogenesis compared with the control.

CONCLUSION

PEG-IFN-α2b in itself had remarkable anti-metastatic effects via inhibition of angiogenesis and cell adhesions.

Hepatic arterial infusion chemotherapy for advanced hepatocellular carcinoma: Is the addition of subcutaneous interferon-alpha-2b beneficial?

AIM

We previously reported the benefits of hepatic arterial infusion chemotherapy (HAIC) using cisplatin (CDDP), 5-fluorouracil (5-FU) [low-dose FP], and leucovorin/isovorin for advanced hepatocellular carcinoma (HCC). In this study, we investigated the efficacy of combination therapy with HAIC and subcutaneous interferon (IFN)- alpha-2b in patients with advanced HCC.

METHODS

Of the 48 patients, 31 received low-dose FP with leucovorin/isovorin (HAIC group) and 17 received combination therapy comprising low-dose FP with isovorin and subcutaneous IFN-alpha-2b (combination group). Prognostic factors were evaluated by univariate and multivariate analyses of the patient and the disease characteristics.

RESULTS

There were no significant differences in the response rate (patients with complete or partial response/all patients; P = 0.736) and survival (P = 0.399) between both groups. Univariate analysis revealed that IFN therapy was not a significant prognostic factor. Multivariate analysis showed 3 variables, namely, Child-Pugh score (P = 0.010), alpha-fetoprotein level (P = 0.0047), and additional therapy (P = 0.002), to be significant prognostic factors.

CONCLUSIONS

We considered that combination therapy with HAIC and subcutaneous interferon (IFN)-alpha-2b was not beneficial for advanced HCC.

Evaluation of newly developed combination therapy of intra-arterial 5-fluorouracil and systemic pegylated interferon alpha-2b for advanced hepatocellular carcinoma with portal venous invasion: preliminary results

AIM

Prognosis is extremely poor for advanced hepatocellular carcinoma (HCC) in patients with portal invasion. The present study evaluated the efficacy of combined intra-arterial 5-fluorouracil (5-FU) and systemic pegylated interferon (PEG-IFN)alpha-2b in patients with advanced HCC.

METHODS

The subjects comprised nine HCC patients with portal vein thrombosis treated using subcutaneous administration of PEG-IFNalpha-2b (50-100 microg on day 1 of every week, for 4 weeks) and intra-arterial infusion of 5-FU (250 mg/day for 5 h on days 1-5 of every week, for 4 weeks). For four patients with hepatitis C virus (HCV) infection, oral administration of ribavirin (400-800 mg/day) was added. At the end of every cycle, response to therapy was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) guidelines.

RESULTS

Partial response (PR) was observed in seven of nine patients, with stable or progressive disease in the remaining two patients. Tumors were resectable in three patients displaying PR after treatment. Tumor markers decreased significantly after therapy. Serum HCV-RNA titers were markedly decreased and became undetectable in all patients with HCV infection. National Cancer Institute-Common Toxicity Criteria: version 3.0 (NCI-CTC) grade 3 thrombocytopenia was seen in one case at the end of treatment, but was resolved with cessation of treatment. Other adverse effects were manageable.

CONCLUSION

Combination therapy with intra-arterial 5-FU and systemic PEG-IFNalpha-2b may be useful as a palliative treatment for patients with advanced HCC. A prospective controlled trial using a larger population of patients with advanced HCC is needed to evaluate this new combination therapy.

Hepatitis C virus infection and apoptosis

Apoptosis is central for the control and elimination of viral infections. In chronic hepatitis C virus (HCV) infection, enhanced hepatocyte apoptosis and upregulation of the death inducing ligands CD95/Fas, TRAIL and TNFα occur. Nevertheless, HCV infection persists in the majority of patients. The impact of apoptosis in chronic HCV infection is not well understood. It may be harmful by triggering liver fibrosis, or essential in interferon (IFN) induced HCV elimination. For virtually all HCV proteins, pro- and anti-apoptotic effects have been described, especially for the core and NS5A protein. To date, it is not known which HCV protein affects apoptosis in vivo and whether the infectious virions act pro- or anti-apoptotic. With the availability of an infectious tissue culture system, we now can address pathophysiologically relevant issues. This review focuses on the effect of HCV infection and different HCV proteins on apoptosis and of the corresponding signaling cascades.

Growth inhibitory effects of IFN-beta on human liver cancer cells in vitro and in vivo

We investigated the effects of interferon-beta (IFN-beta) on the growth of human liver cancer cells. The effects of IFN-beta with or without 5-fluorouracil (5-FU) on the proliferation of 13 liver cancer cell lines were investigated in vitro. Chronologic change in IFN-alpha receptor 2 (IFNAR-2) expression was monitored in hepatocellular carcinoma (HCC) cells (HAK-1B) cultured with IFN-beta. After HAK-1B cells were transplanted into nude mice, various doses of IFN-beta were administered, and the tumor volume, weight, histology, tumor blood vessel, and angiogenesis factor expression were examined. IFN-beta inhibited the growth of 11 cell lines with apoptosis in a dose-dependent and time-dependent manner. With IFN-beta, IFNAR-2 expression in HAK-1B cells was significantly downregulated from 6 to 12 h. IFN-beta induced a dose-dependent decrease in tumor volume and weight and a significant increase of apoptosis in the tumor. Both basic fibroblast growth factor (bFGF) and blood vessel number in the tumor decreased only in mice receiving the lowest dose (1000 IU) of IFN-beta. IFN-beta with 10 muM of 5-FU frequently induced synergistic antiproliferative effects. IFN-beta with or without 5-FU induces strong antitumor effects in HCC cells, and we conclude that IFN-beta is useful for the prevention and treatment of HCC.

Effects of IFN-alpha on alpha-fetoprotein expressions in hepatocellular carcinoma cells

We investigated the effects of pegylated (PEG)-IFN-alpha2b on alpha-fetoprotein (AFP) expression as demonstrated by protein and mRNA levels in six human hepatocellular carcinoma (HCC) cell lines. The number of KIM-1 cells in culture with PEG-IFN-alpha2b decreased between 24 amd 240 h, whereas the levels of intracellular and secreted AFP per cellular protein increased (except at 192 h), with levels 1.9-fold and 2.9-fold higher at maximum, respectively, than cells without PEG-IFN-alpha2b (control). The mRNA level increased between 72 and 192 h, when the level was 3-fold higher than that of the control. In the 72-h culture with 40-5000 IU/mL PEG-IFN-alpha2b, there were dose-dependent increases in AFP protein and mRNA expression and dose-dependent decrease in cell number resulting from apoptosis and blockage of the cell cycle at the S-phase. The rate of fucosylated AFP in the cell lysate decreased in a dose-dependent and time-dependent manner. In the PEG-IFN-alpha2b culture of the other five HCC cell lines, cell proliferation was suppressed, but the expressions of AFP protein and mRNA increased in only two cell lines, and suppression of cell proliferation was not related to the increase in AFP expressions. Our findings demonstrated that PEG-IFN-alpha2b induces an increase in AFP expression at both the protein and mRNA levels.