Recent advances in oncolytic virus therapy for hepatocellular carcinoma

oHSV2-mGM repolarizes TAMs and cooperates with αPD1 to reprogram the immune microenvironment of residual cancer after radiofrequency ablation

BACKGROUND

Due to the size and location of the tumor, incomplete radiofrequency ablation (iRFA) of the target tumor inhibits tumor immunity. In this study, a murine herpes simplex virus (oHSV2-mGM) armed with granulocyte-macrophage colony-stimulating factor (GM-CSF) was constructed to explore its effect on innate and adaptive immunity during iRFA, and the inhibitory effect of programmed cell death-1 (PD1) on tumor.

METHODS

We verified the polarization and activation of RAW264.7 cells mediated by oHSV2-mGM in vitro. Subsequently, we evaluated the efficacy of oHSV2-mGM alone and in combination with αPD1 in the treatment of residual tumors after iRFA in two mouse models. RNA-seq was used to characterize the changes of tumor microenvironment.

RESULTS

oHSV2-mGM lysate effectively stimulated RAW264.7 cells to polarize into M1 cells and activated M1 phenotypic function. In the macrophage clearance experiment, oHSV2-mGM activated the immune response of tumor in mice. The results in vivo showed that oHSV2-mGM showed better anti-tumor effect in several mouse tumor models. Finally, oHSV2-mGM combined with PD1 antibody can further enhance the anti-tumor effect of oHSV2-mGM and improve the complete remission rate of tumor in mice.

CONCLUSION

The application of oHSV2-mGM leads to the profound remodeling of the immune microenvironment of residual tumors. oHSV2-mGM also works in synergy with PD1 antibody to achieve complete remission of tumors that do not respond well to monotherapy at immune checkpoints. Our results support the feasibility of recombinant oncolytic virus in the treatment of residual tumors after iRFA, and propose a new strategy for oncolytic virus treatment of tumors.

Oncolytic virotherapy for hepatocellular carcinoma: A potent immunotherapeutic landscape

Hepatocellular carcinoma (HCC) is a systemic disease with augmented malignant degree, high mortality and poor prognosis. Since the establishment of the immune mechanism of tumor therapy, people have realized that immunotherapy is an effective means for improvement of HCC patient prognosis. Oncolytic virus is a novel immunotherapy drug, which kills tumor cells and exempts normal cells by directly lysing tumor and inducing anti-tumor immune response, and it has been extensively examined as an HCC therapy. This editorial discusses oncolytic viruses for the treatment of HCC, emphasizing viral immunotherapy strategies and clinical applications related to HCC.

Strategies to enhance the response of liver cancer to pharmacological treatments

In contrast to other types of cancers, there is no available efficient pharmacological treatment to improve the outcomes of patients suffering from major primary liver cancers, i.e., hepatocellular carcinoma and cholangiocarcinoma. This dismal situation is partly due to the existence in these tumors of many different and synergistic mechanisms of resistance, accounting for the lack of response of these patients, not only to classical chemotherapy but also to more modern pharmacological agents based on the inhibition of tyrosine kinase receptors (TKIs) and the stimulation of the immune response against the tumor using immune checkpoint inhibitors (ICIs). This review summarizes the efforts to develop strategies to overcome this severe limitation, including searching for novel drugs derived from synthetic, semisynthetic, or natural products with vectorial properties against therapeutic targets to increase drug uptake or reduce drug export from cancer cells. Besides, immunotherapy is a promising line of research that is already starting to be implemented in clinical practice. Although less successful than in other cancers, the foreseen future for this strategy in treating liver cancers is considerable. Similarly, the pharmacological inhibition of epigenetic targets is highly promising. Many novel "epidrugs," able to act on "writer," "reader," and "eraser" epigenetic players, are currently being evaluated in preclinical and clinical studies. Finally, gene therapy is a broad field of research in the fight against liver cancer chemoresistance, based on the impressive advances recently achieved in gene manipulation. In sum, although the present is still dismal, there is reason for hope in the non-too-distant future.

Mechanism-guided fine-tuned microbiome potentiates anti-tumor immunity in HCC

Microbiome, including bacteria, fungi, and viruses, plays a crucial role in shaping distal and proximal anti-tumor immunity. Mounting evidence showed that commensal microbiome critically modulates immunophenotyping of hepatocellular carcinoma (HCC), a leading cause of cancer-related death. However, their role in anti-tumor surveillance of HCC is still poorly understood. Herein, we spotlighted growing interests in how the microbiome influences the progression and immunotherapeutic responses of HCC via changing local tumor microenvironment (TME) upon translocating to the sites of HCC through different "cell-type niches". Moreover, we summarized not only the associations but also the deep insight into the mechanisms of how the extrinsic microbiomes interplay with hosts to shape immune surveillance and regulate TME and immunotherapeutic responses. Collectively, we provided a rationale for a mechanism-guided fine-tuned microbiome to be neoadjuvant immunotherapy in the near future.

Current Trends in Surgical Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Surgical management, including hepatic resection, liver transplantation, and ablation, offers the greatest potential for a curative approach. This review aims to discuss recent advancements in HCC surgery and identify unresolved issues in the field. Treatment selection relies on the BCLC staging system, with surgical therapies primarily recommended for early-stage disease. Recent studies have shown that patients previously considered unresectable, such as those with portal vein tumor thrombus and uncomplicated portal hypertension, may benefit from hepatic resection. Minimally invasive surgery and improved visualization techniques are also explored, alongside new techniques for optimizing future liver remnant, ex vivo resection, and advancements in hemorrhage control. Liver transplantation criteria, particularly the long-standing Milan criteria, are critically examined. Alternative criteria proposed and tested in specific regions are presented. In the context of organ shortage, bridging therapy plays a critical role in preventing tumor progression and maintaining patients eligible for transplantation. Lastly, we explore emerging ablation modalities, comparing them with the current standard, radiofrequency ablation. In conclusion, this comprehensive review provides insights into recent trends and future prospects in the surgical management of HCC, highlighting areas that require further investigation.