Systemic administration of liposome-encapsulated OK-432 prolongs the survival of rats with hepatocellular carcinoma through the induction of IFN-gamma-producing hepatic lymphocytes

Lipid Nanoparticles-Based Therapy in Liver Metastasis Management: From Tumor Cell-Directed Strategy to Liver Microenvironment-Directed Strategy

Metastasis to the liver, as one of the most frequent metastatic patterns, was associated with poor prognosis. Major drawbacks of conventional therapies in liver metastasis were the lack of metastatic-targeting ability, predominant systemic toxicities and incapability of tumor microenvironment modulations. Lipid nanoparticles-based strategies like galactosylated, lyso-thermosensitive or active-targeting chemotherapeutics liposomes have been explored in liver metastasis management. This review aimed to summarize the state-of-art lipid nanoparticles-based therapies in liver metastasis management. Clinical and translational studies on the lipid nanoparticles in treating liver metastasis were searched up to April, 2023 from online databases. This review focused not only on the updates in drug-encapsulated lipid nanoparticles directly targeting metastatic cancer cells in treating liver metastasis, but more importantly on research frontiers in drug-loading lipid nanoparticles targeting nonparenchymal liver tumor microenvironment components in treating liver metastasis, which showed promise for future clinical oncological practice.

Bacterial ghosts as adjuvant to oxaliplatin chemotherapy in colorectal carcinomatosis

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and a major cause of cancer mortality worldwide. At late stage of the disease CRC often shows (multiple) metastatic lesions in the peritoneal cavity which cannot be efficiently targeted by systemic chemotherapy. This is one major factor contributing to poor prognosis. Oxaliplatin is one of the most commonly used systemic treatment options for advanced CRC. However, drug resistance - often due to insufficient drug delivery - is still hampering successful treatment. The anticancer activity of oxaliplatin includes besides DNA damage also a strong immunogenic component. Consequently, the aim of this study was to investigate the effect of bacterial ghosts (BGs) as adjuvant immunostimulant on oxaliplatin efficacy. BGs are empty envelopes of gram-negative bacteria with a distinct immune-stimulatory potential. Indeed, we were able to show that the combination of BGs with oxaliplatin treatment had strong synergistic anticancer activity against the CT26 allograft, resulting in prolonged survival and even a complete remission in this murine model of CRC carcinomatosis. This synergistic effect was based on an enhanced induction of immunogenic cell death and activation of an efficient T-cell response leading to long-term anti-tumor memory effects. Taken together, co-application of BGs strengthens the immunogenic component of the oxaliplatin anticancer response and thus represents a promising natural immune-adjuvant to chemotherapy in advanced CRC.

Cancer vaccines and immunotherapeutic approaches in hepatobiliary and pancreatic cancers

Hepatobiliary and pancreatic cancers along with other gastrointestinal malignancies remain the leading cause of cancer-related deaths worldwide. Strategies developed in the recent years on immunotherapy and cancer vaccines in the setting of primary liver cancer as well as in pancreatic cancer are the scope of this review. Significance of orthotopic and autochthonous animal models which mimic and/or closely reflect human malignancies allowing for a prompt and trustworthy analysis of new therapeutics is underlined. Combinational approaches that on one hand, specifically target a defined cancer-driving pathway, and on the other hand, restore the functions of immune cells, which effector functions are often suppressed by a tumor milieu, are shown to have the strongest perspectives and future directions. Among combinational immunotherapeutic approaches a personalized- and individual cancer case-based therapy is of special importance.

The current status of immunotherapy in peritoneal carcinomatosis

INTRODUCTION

Peritoneal carcinomatosis (PC) is a cancer disease with an urgent need for effective treatment. Conventional chemotherapy failed to show acceptable results. Cytoreductive surgery and hyperthermic chemoperfusion (HIPEC) are only beneficial in few patients with resectable peritoneal metastasis. Immunotherapy could be attractive against PC, as all requirements for immunotherapy are available in the peritoneal cavity.

AREAS COVERED

This review analyzes the present literature for immunotherapy of PC. Advances from immune stimulators, radionucleotide-conjugated- and bispecific antibodies to future developments like adoptive engineered T-cells with chimeric receptors are discussed. The clinical development of catumaxomab, which was the first intraperitoneal immunotherapy to be approved for clinical treatment, is discussed. The requirements for future developments are illustrated. Expert commentary: Immunotherapy of peritoneal carcinomatosis is manageable, showing striking cancer cell killing. Improved profiles of adverse events by therapy-induced cytokine release, enhanced specific killing and optimal treatment schedules within multimodal treatment will be key factors.

The application of antitumor drug-targeting models on liver cancer

Hepatocarcinoma animal models, such as the induced tumor model, transplanted tumor model, gene animal model, are significant experimental tools for the evaluation of targeting drug delivery system as well as the pre-clinical studies of liver cancer. The application of antitumor drug-targeting models not only furnishes similar biological characteristics to human liver cancer but also offers guarantee of pharmacokinetic indicators of the liver-targeting preparations. In this article, we have reviewed some kinds of antitumor drug-targeting models of hepatoma and speculated that the research on this field would be capable of attaining a deeper level and expecting a superior achievement in the future.

Immunomodulatory effect of diethylcarbamazine citrate plus filarial excretory-secretory product on rat hepatocarcinogenesis

Diethylcarbamazine citrate (DEC) had a significance in anti-filarial chemotherapy, while excretory-secretory product (ES) is released from adult filarial females. The target of the current study was to examine the immunomodulatory effect of DEC, Setaria equina ES or a combination of them on rat hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN). In vitro effect of combined DEC and ES or ES alone on lipopolysaccharide (LPS)-stimulated rat peripheral blood mononuclear cells (PBMCs) was tested through IFN-γ assay in culture supernatants. In addition, single or repeated doses of DEC, ES or DEC+ES have been applied in white albino rats to test the effect on HCC. Levels of IFN-γ and anti-ES IgG antibodies in rat serum were assayed using ELISA. Hemolytic complement activity (CH50) was determined in serum while the concentration of nitric oxide (NO) was assayed in liver tissue. The infiltration of NK cells as well as the expression of MHC Iproliferating cell nuclear antigen (PCNA), inducible NO synthase (iNOS), Bcl2 and p53 were determined using immunohistochemistry. There was a dose-dependent increase in IFN-γ after in vitro exposure to DEC+ES. Repeated ES doses increased NO concentration (p<0.05) and expression of iNOS but reduced CH50 (p<0.001), while repeated DEC+ES doses could increase anti-ES IgG (p<0.01), IFN-γ level (p<0.05) and NK cell infiltration. The same treatments could also reduce the expression of MHC I expression, PCNA, Bcl2 and p53. This study has shown immunomodulatory and protective effects of DEC+ES repeated doses on rat HCC.

Intra-arterial interleukin-12 gene delivery combined with chemoembolization: anti-tumor effect in a rabbit hepatocellular carcinoma (HCC) model

BACKGROUND

Interleukin-12 (IL-12), a cytokine naturally secreted by activated dendritic cells and monocytes/macrophages, is known as a key anti-tumor agent in many tumor models, including hepatocellular carcinoma (HCC) models.

PURPOSE

To evaluate the anti-tumor effect of intra-arterial IL-12 gene delivery alone and in combination with transcatheter arterial chemoembolization (TACE) in rabbit VX2 liver cancer model.

MATERIAL AND METHODS

Rabbits with VX2 liver tumors were randomized into four groups, eight in each group. After laparotomy and insertion of a 30-gauge needle into the proper hepatic artery, the following interventional procedure protocols were applied: 0.9% saline solution (group A, control), TACE (group B, TACE alone, lipiodol + mitomycin), intra-arterial interleukin-12 gene infusion (group C, IL-12 alone), and intra-arterial interleukin-12 gene infusion in combination with TACE (group D, IL-12 plus TACE). Growth ratio was estimated by computed tomography. To analyze apoptotic index, tumor tissues were explanted for terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining, 14 days after therapy.

RESULTS

Significant differences of the relative tumor growth ratio were observed in TACE alone group and IL-12 plus TACE group in comparison with control (P < 0.05, ANOVA, Tukey's HSD correction) but not between IL-12 alone and control, or IL-12 plus TACE group and TACE alone group (P > 0.05). Significant changes of the apoptotic index were observed in group D in comparison with remaining three groups (P < 0.05). The difference between group C and group A was not significant statistically (P > 0.05).

CONCLUSION

Intra-arterial interleukin-12 gene therapy combined with TACE has a potent anti-tumor effect in rabbit VX2 liver cancer in comparison with TACE alone.

Drug-eluting stent in malignant biliary obstruction

INTRODUCTION

In unresectable malignant bile duct obstruction, endoscopic stent insertion is the treatment of choice. However, the current stent allows only mechanical palliation of the obstruction, and has no anti-tumor effect. Currently, in the vascular field, the drug-eluting stent (DES) is very highly favored.

MATERIAL AND METHODS

The requirements for a DES in a non-vascular tract, such as the bile duct, are far different from those of a DES to be used in the vascular tract. The non-vascular DES must suppress tumor proliferation as well as mucosal hyperplasia. For example, the non-vascular stent might be covered with a membrane that gradually releases a chemo-agent. We do not have much experience with DES in the bile duct. Nonetheless, we are continuously testing many anti-tumor agents in animal and human studies.

CONCLUSION

We expect and hope DES will work effectively for tumor cells in diverse ways and, more importantly, will prolong stent patency and the patients' survival periods. But considerable investigation and a clinical study of DES will be required to achieve these goals.

Orthotopic hepatocellular carcinoma model with a controlled and reproducible tumorigenicity

BACKGROUND

To explore therapeutic strategies for hepatocellular carcinoma (HCC) there is a need for a suitable and reproducible animal model. However, most models produced thus far have drawbacks such as high rates of artificial tumor dissemination and complexity of the implantation technique. To circumvent these issues, we selected an appropriate HCC cell line coupled with a simple modality to prevent unintended tumor cell dissemination.

METHOD

KDH-8 cells were inoculated into the rat liver. To prevent tumor cell leakage, a human fibrinogen/thrombin-coated collagen patch was attached on the site after withdrawal of the needle. In some animals, ligation of the hepatic artery was performed.

RESULTS

Early after injection, all rats (n = 60) developed a solitary nodule. Successful inoculation was observed in all animals with a leakage (dissemination) rate of 0%. Computed tomography (CT) demonstrated a well-demarcated low density mass accompanied with a central necrosis that mimicked a typical CT image of human HCC. Doppler ultrasonography demonstrated a vascularized property of the tumor. Tumor volumes increased with time, reaching 3299.5 +/- 290.0 mm3 at day 28 after inoculation. Thus the formed KDH-8 hepatoma was pathologically classified into a poorly differentiated HCC demarcated with surrounding connective tissue. After hepatic arterial ligation, tumor growth was impeded with an inhibition of 59.1 and 70.4% (day 21 and 28, respectively).

CONCLUSIONS

The current orthotopic hepatoma model enables a controlled and reproducible tumorigenicity and displays properties and histopathology resembling human HCC. It may be a useful tool in the investigation of antiangiogenic and anticancer therapeutics.

Local delivery system of immune modulating drug for unresectable adenocarcinoma: in vitro experimental study and in vivo animal study

The purpose of the study was to evaluate the efficacy and safety of a developed drug delivery system containing OK-432 through in vitro and animal study. An OK-432-impregnated polycarbonate/polyurethane stent membrane was used to develop a drug delivery system (DDS) enabling the locoregional release of OK-432. Polyethyleneglycol was used as a detergent and porosity generator. The stability of OK-432 in solvent, releasing kinetics of drug, and cytotoxicity of the DDS were evaluated. OK-432-impregnated DDS was implanted in mice in which a human adenocarcinoma cell line was injected and grown in their back. Flow cytometry and enzyme-linked immunosorbent assay were used for quantifying the amount of drug. OK-432 exposed to phosphate-buffered saline and OK-432 exposed to N,N-dimethylacetamide showed similar results on dot graphs and histograms. However, OK-432 exposed to tetrahydrofurane showed different dot graphs and histograms, which means that the antigenicity of the drug was changed. The release rate of OK-432 was maintained at a constant level for 6 weeks. The local delivery of OK-432 was found to have an antitumor effect on a human adenocarcinoma cell line in an animal study, but no effect on this cell line in in vitro cell culture. Histologic examination showed minimal inflammatory reaction in surrounding tissue. Our study shows that local treatment using this OK-432 release system is safe and effective in reducing adenocarcinoma in a mouse model.

Transarterial chemoembolization alone and in combination with other therapies: a comparative study in an animal HCC model

The purpose of this study is to compare transarterial chemoembolization (TACE) alone and in combination with other therapies in an animal model. Subcapsular implantation of a solid Morris hepatoma 3924A in the liver was carried out in 50 male ACI rats (day 0). Tumor volume (V1) was measured by MRI (day 13). After laparotomy and retrograde placement of a catheter into the gastroduodenal artery (day 14), the following protocols of the interventional procedure were applied: TACE (mitomycin C + lipiodol) + immunotherapy (group A: TNFalpha + IL-2, group B: OK-432 + IL-2); TACE + antiangiogenesis therapy (group C: TNP-470, group D: endostatin); TACE alone in group E (control group). Tumor volume (V2) was assessed by MRI and the mean ratio of x (V2/V1) was calculated. Data were analyzed using Dunnett's t test (comparing therapeutic groups with the control group) and the Student-Newman-Keuls test (comparing significant therapeutic groups). Multivariate analysis showed a significant reduction in the tumor growth rate (P<0.05) in groups B (x=6.53) and C (x=4.01) compared to the mean ratio of the control group E (x=9.14). Significant results were observed in group C (P<0.05) in comparison with the other therapeutic groups. TACE combined with immunotherapy (OK-432) and antiangiogenesis therapy (TNP-470) retards tumor growth compared with TACE alone in an HCC animal model.

Combined interventional therapies of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, responsible for an estimated one million deaths annually. It has a poor prognosis due to its rapid infiltrating growth and complicating liver cirrhosis. Surgical resection, liver transplantation and cryosurgery are considered the best curative options, achieving a high rate of complete response, especially in patients with small HCC and good residual liver function. In nonsurgery, regional interventional therapies have led to a major breakthrough in the management of unresectable HCC, which include transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), microwave coagulation therapy (MCT), laser-induced thermotherapy (LITT), etc. As a result of the technical development of locoregional approaches for HCC during the recent decades, the range of combined interventional therapies has been continuously extended. Most combined multimodal interventional therapies reveal their enormous advantages as compared with any single therapeutic regimen alone, and play more important roles in treating unresectable HCC.