IkappaBalpha gene therapy in tumor necrosis factor-alpha- and chemotherapy-mediated apoptosis of hepatocellular carcinomas

Regorafenib diminishes the expression and secretion of angiogenesis and metastasis associated proteins and inhibits cell invasion via NF-κB inactivation in SK-Hep1 cells

The aim of the present study was to investigate the effects of regorafenib on the nuclear factor κ-light-chain-enhancer of activated B cells (NF)-κB-modulated expression of angiogenesis- and metastasis-associated proteins and cell invasion in human hepatocellular carcinoma SK-Hep1 cells. The SK-Hep1 cells were treated with different concentrations of NF-κB inhibitor 4-N-[2-(4-phenoxyphenyl) ethyl] quinazoline-4,6-diamine (QNZ) or regorafenib for 24 or 48 h. The effects of QNZ and regorafenib on cell viability, NF-κB activation, expression and secretion levels of angiogenesis- and metastasis-associated proteins and cell invasion were evaluated with MTT assays, western blotting, ELISA, gelatin zymography and cell invasion assays. The results demonstrated that QNZ and regorafenib significantly reduced the expression and secretion levels of the angiogenesis- and metastasis-associated proteins vascular endothelial growth factor, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, matrix metalloproteinase (MMP)-2 and MMP-9, NF-κB activation and cell invasion. In conclusion, the inhibition of NF-κB activation induces anti-angiogenic and antimetastatic effects in SK-Hep1 cells. Regorafenib reduces the level of expression and secretion of angiogenesis- and metastasis-associated proteins and cell invasion through the suppression of NF-κB activation in SK-Hep1 cells.

Doxorubicin-induced death in tumour cells and cardiomyocytes: is autophagy the key to improving future clinical outcomes?

Objectives

Doxorubicin, a commonly used frontline chemotherapeutic agent for cancer, is not without side-effects. The original thinking that the drug causes necrosis in tumours has largely given way to its link with apoptosis over the past two decades.

Key findings

More recently, major biomarkers such as AMPK, p53 and Bcl-2 have been identified as important to apoptosis induction by doxorubicin. It is Bcl-2 and its interaction with Beclin-1 that has refocussed research attention on doxorubicin, albeit this time for its ability to induce autophagy. Autophagy can be either anticancerous or procancerous however, so it is critical that the reasons for which cancer cells undergo this type of cell biological event be clearly identified for future exploitation.

Summary

Taking a step back from treating patients with large doses of doxorubicin, which causes toxicity to the heart amongst other organs, and further research with this drug's molecular signalling in not only neoplastic but normal cells, may indeed redefine the way doxorubicin is used clinically and potentially lead to better neoplastic disease management.

Recombinant VP1, an Akt inhibitor, suppresses progression of hepatocellular carcinoma by inducing apoptosis and modulation of CCL2 production

Background

The application of viral elements in tumor therapy is one facet of cancer research. Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus has previously been demonstrated to induce apoptosis in cancer cell lines. Here, we aim to further investigate its apoptotic mechanism and possible anti-metastatic effect in murine models of hepatocellular carcinoma (HCC), one of the most common human cancers worldwide.

Methodology/Principal Findings

Treatment with rVP1 inhibited cell proliferation in two murine HCC cell lines, BNL and Hepa1-6, with IC₅₀ values in the range of 0.1–0.2 µM. rVP1 also induced apoptosis in these cells, which was mediated by Akt deactivation and dissociation of Ku70-Bax, and resulted in conformational changes and mitochondrial translocation of Bax, leading to the activation of caspases-9, -3 and -7. Treatment with 0.025 µM rVP1, which did not affect the viability of normal hepatocytes, suppressed cell migration and invasion via attenuating CCL2 production. The production of CCL2 was modulated by Akt-dependent NF-κB activation that was decreased after rVP1 treatment. The in vivo antitumor effects of rVP1 were assessed in both subcutaneous and orthotopic mouse models of HCC in immune-competent BALB/c mice. Intratumoral delivery of rVP1 inhibited subcutaneous tumor growth as a result of increased apoptosis. Intravenous administration of rVP1 in an orthotopic HCC model suppressed tumor growth, inhibited intra-hepatic metastasis, and prolonged survival. Furthermore, a decrease in the serum level of CCL2 was observed in rVP1-treated mice.

Conclusions/Significance

The data presented herein suggest that, via inhibiting Akt phosphorylation, rVP1 suppresses the growth, migration, and invasion of murine HCC cells by inducing apoptosis and attenuating CCL2 production both in vitro and in vivo. Recombinant protein VP1 thus has the potential to be developed as a new therapeutic agent for HCC.

Gene therapy targeting nuclear factor-kappaB: towards clinical application in inflammatory diseases and cancer

Nuclear factor (NF)-κB is regarded as one of the most important transcription factors and plays an essential role in the transcriptional activation of pro-inflammatory cytokines, cell proliferation and survival. NF-κB can be activated via two distinct NF-κB signal transduction pathways, the so-called canonical and non-canonical pathways, and has been demonstrated to play a key role in a wide range of inflammatory diseases and various types of cancer. Much effort has been put in strategies to inhibit NF-κB activation, for example by the development of pharmacological compounds that selectively inhibit NF-κB activity and therefore would be beneficial for immunotherapy of transplantation, autoimmune and allergic diseases, as well as an adjuvant approach in patients treated with chemotherapy for cancer. Gene therapy targeting NF-κB is a promising new strategy with the potential of long-term effects and has been explored in a wide variety of diseases, ranging from cancer to transplantation medicine and autoimmune diseases. In this review we discuss recent progress made in the development of NF-κB targeted gene therapy and the evolution towards clinical application.

Effect of tumour necrosis factor-alpha and irradiation alone or in combination on the viability of hepatocellular and biliary adenocarcinoma cell lines in vitro

BACKGROUND

Tumour necrosis factor alpha (TNF-alpha) may exhibit antitumoral activity and can influence the reaction of both tumour and normal tissue to radiation.

AIMS

To test the effect of TNF-alpha and/or irradiation on hepatocellular (HepG2, Hep3B, Sk-Hep1, HuH7) and cholangiocellular (Sk-chA1, Mz-chA1) tumour cell lines.

METHODS

Colony formation, apoptosis analysis and trypan blue exclusion were used to assess cell viability. Doses of radiation (2-25 Gy) and TNF-alpha (100-50,000 U) as well as their respective sequencing were varied (24 and 12 h before and 6 h after). The expression of TNF-alpha and TNF receptors 1/2 was determined using real-time polymerase chain reaction and IkappaBalpha protein expression was detected by Western blot.

RESULTS

Sole irradiation induced a reduction in colony formation in all cell lines and sole TNF-alpha in HepG2 and Sk-chA1 cells only. No difference in apoptosis induction after TNF-alpha or irradiation was observed. Cellular death induced by the combination of TNF-alpha and radiation was not superior to the use of any of the two agents alone. All cell lines revealed that radiation induced upregulation of TNF-alpha whereas the extent of TNF receptor-specific transcription did not change. Furthermore, radiation-induced changes in IkappaBalpha expression were not detectable.

CONCLUSIONS

Our data suggest that both TNF-alpha and radiation may be treatment options for hepatocellular and cholangiocellular carcinomas. Because TNF-alpha and radiation do not interact in terms of radiosensitization, anti-TNF-alpha treatment may have the potential to protect against hepatocellular injury after abdominal irradiation. However, further in vivo studies are needed to confirm that anti-TNF-alpha treatment does not compromise tumour control and actually attenuates radiation-induced liver injury.

To be, or not to be: NF-kappaB is the answer--role of Rel/NF-kappaB in the regulation of apoptosis

During their lifetime, cells encounter many life or death situations that challenge their very own existence. Their survival depends on the interplay within a complex yet precisely orchestrated network of proteins. The Rel/NF-kappaB signaling pathway and the transcription factors that it activates have emerged as critical regulators of the apoptotic response. These proteins are best known for the key roles that they play in normal immune and inflammatory responses, but they are also implicated in the control of cell proliferation, differentiation, apoptosis and oncogenesis. In recent years, there has been remarkable progress in understanding the pathways that activate the Rel/NF-kappaB factors and their role in the cell's decision to either fight or surrender to apoptotic challenge. Whereas NF-kappaB is most commonly involved in suppressing apoptosis by transactivating the expression of antiapoptotic genes, it can promote programmed cell death in response to certain death-inducing signals and in certain cell types. This review surveys our current understanding of the role of NF-kappaB in the apoptotic response and focuses on many developments since this topic was last reviewed in Oncogene 4 years ago. These recent findings shed new light on the activity of NF-kappaB as a critical regulator of apoptosis in the immune, hepatic, epidermal and nervous systems, on the mechanisms through which it operates and on its role in tissue development, homoeostasis and cancer.

Gene therapy of hepatocarcinoma: a long way from the concept to the therapeutical impact

Hepatocellular carcinoma (HCC), the most prevalent histological form of primary liver cancer is one of the most frequent cancer worldwide. This pathology still requires the development of new therapeutical approaches. Gene therapy strategies focusing on the genetic manipulation of accessory cells involved in the immune reaction against cancer cells, or on the direct transduction of tumor cells with transgenes able to "suicide" cancer cells have been largely developed for more than ten years.

Elevated expression of valosin-containing protein (p97) in hepatocellular carcinoma is correlated with increased incidence of tumor recurrence

PURPOSE

Valosin-containing protein (VCP; also known as p97) has been shown to be associated with antiapoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. In this study, association of VCP expression with recurrence of hepatocellular carcinoma (HCC) and patient survival was examined.

PATIENTS AND METHODS

VCP expression in 170 patients (139 male and 31 female) with ages ranging from 31 to 81 years (median, 61 years) was analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, in which staining intensity in tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells.

RESULTS

Immunohistochemically, 57 patients (35.2%) showed level 1, and 105 patients (64.8%) showed level 2, VCP expression. Quantitative RT-PCR analysis revealed higher VCP mRNA expression in level 2 patients (n = 7) than level 1 (n = 4) (P <.05). Patients with VCP-level 2 HCC showed higher rate of portal vein invasion in the tumor (P <.01) and poorer disease-free and overall survival (P <.0001 and P <.05, respectively) compared with level 1 patients. Multivariate analysis revealed VCP expression level, tumor multiplicity, and degree of fibrosis in the noncancerous liver tissue to be independent prognosticators for disease-free and overall survival. VCP level was an indicator for disease-free survival in each early- (I and II) and advanced- (III and IV) stage group of pathologic tumor-node-metastasis classification (P <.001 and P <.01, respectively).

CONCLUSION

VCP expression level has prognostic significance for disease-free and overall survival of patients with HCC.

Doxorubicin induces apoptosis and CD95 gene expression in human primary endothelial cells through a p53-dependent mechanism

Regulation of the homeostasis of vascular endothelium is critical for the processes of vascular remodeling and angiogenesis under physiological and pathological conditions. Here we show that doxorubicin (Dox), a drug used in antitumor therapy, triggered a marked accumulation of p53 and induced CD95 gene expression and apoptosis in proliferating human umbilical vein endothelial cells (HUVECs). Transfection and site-directed mutagenesis experiments using the CD95 promoter fused to an intronic enhancer indicated the requirement for a p53 site for Dox-induced promoter activation. Furthermore, the p53 inhibitor pifithrin-alpha (PFT-alpha) blocked both promoter inducibility and protein up-regulation of CD95 in response to Dox. Up-regulated CD95 in Dox-treated cells was functional in eliciting apoptosis upon incubation of the cells with an agonistic CD95 antibody. However, Dox-mediated apoptosis was independent of CD95/CD95L interaction. The analysis of apoptosis in the presence of PFT-alpha and benzyloxycarbonyl-Val-Ala-dl-Asp-fluoromethylketone revealed that both p53 and caspase activation are required for Dox-mediated apoptosis of HUVECs. Finally, Dox triggered Bcl-2 down-regulation, cytochrome c release from mitochondria, and the activation of caspases 9 and 3, suggesting the involvement of a mitochondrially operated pathway of apoptosis. These results highlight the role of p53 in the response of primary endothelial cells to genotoxic drugs and may reveal a novel mechanism underlying the antitumoral properties of Dox, related to its ability to induce apoptosis in proliferating endothelial cells.

Pharmacokinetics of radioimmunotherapeutic agent of direct labeling mAb 188Re-HAb18

AIM: To label anti-hepatoma monoclonal antibody (mAb) fragment HAb18 F(ab’)₂ was labeled with ¹⁸⁸Re for the pharmacokinetic model of ¹⁸⁸Re-HAb18 F(ab’)₂ and to evaluate its pharmacokinetic parameters in hepatoma-bearing nude mice.

METHODS: HAb18 F(ab’)₂ was directly labeled with ¹⁸⁸Re using 2-mercaptoethanol (2-ME) as reducing agents. Labeling efficiency and immunoreactivity of ¹⁸⁸Re-HAb18 F(ab’)₂ were evaluated by Whatman 3MM paper chromatography and live cell assay, respectively. Biodistribution analysis was also conducted in nude mice bearing human hepatoma in which animals were sacrificed at different time points (1, 4, 18, 24 and 24 h) after ¹⁸⁸Re-HAb18 F (ab’)₂ was injected through tail-vein into hepatoma-bearing nude mice. The blood and radioactivity of organs and mass were measured. The concentrations of ¹⁸⁸Re-HAb18 F(ab’)₂ were evaluated with apharmacokinetic 3P97 software.

RESULTS: The optimum labeling efficiency and immunoreactive fraction were 91.7% and 0.78% respectively. The parameters of ¹⁸⁸Re-HAb18 F(ab’)₂ were: T_1/2, 2.29 h; Vd,1.49 × 10^-9 L·Bq^-1; AUC, 20. 49 × 10⁹ Bq·h·L^-1;CL, 0.45 × 10^-3 L·h^-1. ¹⁸⁸Re-HAb18 F(ab’)₂ could locate specially in hepatoma with high selective reactivity of HAb18 F(ab’)₂. ¹⁸⁸Re-HAb18 F(ab’)₂ was mainly eliminated by kidney. The maximal tumor to blood ratio was at 48 h, and maximal tumor to liver ratio was at 18 h.

CONCLUTION: The pharmacokinetics of ¹⁸⁸Re-HAb18 F (ab’)₂ fital-compartment model.¹⁸⁸Re-HAb18 F(ab’)₂ can be uptaken selectively at the hepatoma site.

NF-kappa B activation mediates doxorubicin-induced cell death in N-type neuroblastoma cells

Neuroblastoma is the most common extracranial solid tumor of childhood. N-type neuroblastoma cells (represented by SH-SY5Y and IMR32 cell lines) are characterized by a neuronal phenotype. N-type cell lines are generally N-myc amplified, express the anti-apoptotic protein Bcl-2, and do not express caspase-8. The present study was designed to determine the mechanism by which N-type cells die in response to specific cytotoxic agents (such as cisplatin and doxorubicin) commonly used to treat this disease. We found that N-type cells were equally sensitive to cisplatin and doxorubicin. Yet death induced by cisplatin was inhibited by the nonselective caspase inhibitor z-Val-Ala-Asp-fluoromethylketone or the specific caspase-9 inhibitor N-acetyl-Leu-Glu-His-Asp-aldehyde, whereas in contrast, caspase inhibition did not prevent doxorubicin-induced death. Neither the reactive oxygen species nor the mitochondrial permeability transition appears to play an important role in this process. Doxorubicin induced NF-kappa B transcriptional activation in association with I-kappa B alpha degradation prior to loss of cell viability. Surprisingly, the antioxidant and NF-kappa B inhibitor pyrrolidine dithiocarbamate blocked doxorubicin-induced NF-kappa B transcriptional activation and provided profound protection against doxorubicin killing. Moreover, SH-SY5Y cells expressing a super-repressor form of I-kappa B were completely resistant to doxorubicin killing. Together these findings show that NF-kappa B activation mediates doxorubicin-induced cell death without evidence of caspase function and suggest that cisplatin and doxorubicin engage different death pathways to kill neuroblastoma cells.