Natural killer cells inhibit pulmonary metastasis of hepatocellular carcinoma in nude mice

Liver, Tumor and Viral Hepatitis: Key Players in the Complex Balance Between Tolerance and Immune Activation

Liver cancer is the third most common cause of cancer related death in the World. From an epidemiological point of view the risk factors associated to primary liver cancer are mainly viral hepatitis infection and alcohol consumption. Even though there is a clear correlation between liver inflammation, cirrhosis and cancer, other emerging liver diseases (like fatty liver) could also lead to liver cancer. Moreover, the liver is the major site of metastasis from colon, breast, ovarian and other cancers. In this review we will address the peculiar status of the liver as organ that has to balance between tolerance and immune activation. We will focus on macrophages and other key cellular components of the liver microenvironment that play a central role during tumor progression. We will also discuss how current and future therapies may affect the balance toward immune activation.

The role of natural killer cells in hepatocellular carcinoma development and treatment: A narrative review

A major obstacle for treatment of HCC is the inadequate efficacy and limitation of the available therapeutic options. Despite the recent advances in developing novel treatment options, HCC still remains one of the major causes of cancer morbidity and mortality around the world. Achieving effective treatment and eradication of HCC is a challenging task, however recent studies have shown that targeting Natural Killer cells, as major regulators of immune system, can help with the complete treatment of HCC, restoration of normal liver function and subsequently higher survival rate of HCC patients. Studies have shown that decrease in the frequency of NK cells, their dysfunction due to several factors such as dysregulation of receptors and their ligands, and imbalance of different types of inhibitory and stimulating microRNA expression is associated with higher rate of HCC progression and development, and poor survival outcome. Here in our review, we mainly focused on the importance of NK cells in HCC development and treatment.

Complete response of hepatocellular carcinoma with right atrium and pulmonary metastases treated by combined treatments (a possible treatment effect of natural killer cell): A case report and literature review

RATIONALE

Hepatocellular carcinomas (HCCs) with metastases to the right atrium (RA) and lungs are rare, with a poor prognosis. Furthermore, the treatment outcomes in patients with advanced HCCs remain unsatisfactory.

PATIENT CONCERNS

A 46-year-old man presented to our hospital for dyspnea on exertion and abdominal pain.

DIAGNOSES

HCC and extra-hepatic metastases to the lung and RA.

INTERVENTIONS

Multidisciplinary treatment including radiotherapy (RT), transarterial chemoembolization (TACE), and sorafenib. During a follow-up evaluation computed tomography, he experienced a radio-contrast-induced anaphylaxis. After the event, treatment such as RT, TACE, and sorafenib were continued.

OUTCOMES

His tumor burden decreased, finally leading to a complete response as per the modified Response Evaluation Criteria in Solid Tumors. The patient is still alive, 30 months after the episode. Subsequent blood tests showed increased natural killer (NK) cell activity, which was significantly higher than that seen in other age-matched HCC patients with an identical stage of the tumor, receiving sorafenib. This suggests that the increase in NK cells induced by anaphylaxis influenced the tumor burden.

LESSONS

We report here a rare case of long-term survival of an HCC patient with multiple metastases treated with multidisciplinary modalities, in which high NK cell activity was observed after a radio-contrast-induced anaphylactic reaction during follow-up investigations.

Antitumor effect of antibiotic resistance gene-free plasmids encoding interleukin-12 in canine melanoma model

The electrotransfer of interleukin-12 (IL-12) has been demonstrated as an efficient and safe treatment for tumors in veterinary oncology. However, the plasmids used encode human or feline IL-12 and harbor the gene for antibiotic resistance. Therefore, our aim was to construct plasmids encoding canine IL-12 without the antibiotic resistance genes driven by two different promoters: constitutive and fibroblast-specific. The results obtained in vitro in different cell lines showed that following gene electrotransfer, the newly constructed plasmids had cytotoxicity and expression profiles comparable to plasmids with antibiotic resistance genes. Additionally, in vivo studies showed a statistically significant prolonged tumor growth delay of CMeC-1 tumors compared to control vehicle-treated mice after intratumoral gene electrotransfer. Besides the higher gene expression obtained by plasmids with constitutive promoters, the main difference between both plasmids was in the distribution of the transgene expression. Namely, after gene electrotransfer, plasmids with constitutive promoters showed an increase of serum IL-12, whereas the gene expression of IL-12, encoded by plasmids with fibroblast-specific promoters, was restricted to the tumor. Furthermore, after the gene electrotransfer of plasmids with constitutive promoters, granzyme B-positive cells were detected in the tumor and spleen, indicating a systemic effect of the therapy. Therefore, plasmids with different promoters present valuable tools for focused therapy with local or systemic effects. The results of the present study demonstrated that plasmids encoding canine IL-12 under constitutive and fibroblast-specific promoters without the gene for antibiotic resistance provide feasible tools for controlled gene delivery that could be used for the treatment of client-owned dogs.

Adoptive natural killer cell therapy is effective in reducing pulmonary metastasis of Ewing sarcoma

The survival of patients with metastatic or relapsed Ewing sarcoma (ES) remains dismal despite intensification of combination chemotherapy and radiotherapy, precipitating the need for novel alternative therapies with minimal side effects. Natural killer (NK) cells are promising additions to the field of cellular immunotherapy. Adoptive NK cell therapy has shown encouraging results in hematological malignancies. Despite these initial promising successes, however, NK cell therapy for solid tumors remains to be investigated using in vivo tumor models. The purpose of this study is to evaluate the efficacy of ex vivo expanded human NK cells in controlling primary and metastatic ES tumor growth in vitro and in vivo. Using membrane-bound IL-21 containing K562 (K562-mbIL-21) expansion platform, we were able to obtain sufficient numbers of expanded NK (eNK) cells that display favorable activation phenotypes and inflammatory cytokine secretion, along with a strong in vitro cytotoxic effect against ES. Furthermore, eNK therapy significantly decreased lung metastasis without any significant therapeutic effect in limiting primary tumor growth in an in vivo xenograft model. Our data demonstrate that eNK may be effective against pulmonary metastatic ES, but challenges remain to direct proper trafficking and augmenting the cytotoxic function of eNK to target primary tumor sites.

Overexpression of Interferon Regulatory Factor 7 (IRF7) Reduces Bone Metastasis of Prostate Cancer Cells in Mice

The purpose of this study was to identify the role of interferon regulatory factor 7 (IRF7) in the bone metastasis of prostate cancer. Herein we demonstrated the lower expression of IRF7 in bone metastases of prostate cancer. Overexpression of IRF7 in prostate cancer cells had a marked effect on inhibiting bone metastases but not on tumor growth in xenograft nude mice. While in vitro, upregulation of IRF7 had little effect on the malignant phenotype of prostate cancer cells including proliferation, apoptosis, migration, and invasion. However, prostate cancer cells overexpressing IRF7 significantly enhanced the activity of NK cells, which resulted in the cytolysis of prostate cancer target cells. The underlying mechanism may be relevant to the increasing expression of IFN-β induced by IRF7, as the downregulation of which could inversely inhibit the activity of NK cells. In conclusion, our findings indicate that IRF7 plays a role in reducing bone metastasis of prostate cancer by IFN-β-mediated NK activity.