Strategies for improving the efficacy of immunotherapy in hepatocellular carcinoma

Predictive value of circulating immune cell changes in response to PD-1 blockade and TKI therapy in patients with hepatocellular carcinoma

PURPOSE

This study investigated the dynamic changes in circulating immune cells following immune checkpoint inhibitors (ICIs), tyrosine kinase inhibitors (TKIs), and interventional therapy in hepatocellular carcinoma (HCC).

METHODS

HCC patients undergoing transarterial chemoembolization (TACE), TKI, and ICI treatment were included in the treatment group. Peripheral blood samples were collected from these patients before each cycle of PD-1 blockade treatment. Flow cytometry analysis was conducted to assess the composition of peripheral immune cells and identify PD-1-expressing T cells.

RESULTS

The treatment group showed a median time-to-tumor progression (TTP) of 8 months and an overall survival (OS) of 19 months. In comparison, the control group had 6 months and 15 months respectively. These differences were statistically significant (P = 0.029 for TTP and P = 0.020 for OS). In HCC patients receiving Lenvatinib, more circulating natural killer (NK) cells were noted. After 1-2 cycles of PD-1 antibody treatment, a general decline in the proportion of circulating PD-1+T cells was found, indicating individual variations in response.

CONCLUSION

Circulating immune cells have the potential to serve as indicators of the response to immunotherapy, providing a means to monitor dynamic changes and optimize treatment for HCC.

Immunosuppressive tumor microenvironment and immunotherapy of hepatocellular carcinoma: current status and prospectives

Hepatocellular carcinoma (HCC) is a major health concern worldwide, with limited therapeutic options and poor prognosis. In recent years, immunotherapies such as immune checkpoint inhibitors (ICIs) have made great progress in the systemic treatment of HCC. The combination treatments based on ICIs have been the major trend in this area. Recently, dual immune checkpoint blockade with durvalumab plus tremelimumab has also emerged as an effective treatment for advanced HCC. However, the majority of HCC patients obtain limited benefits. Understanding the immunological rationale and exploring novel ways to improve the efficacy of immunotherapy has drawn much attention. In this review, we summarize the latest progress in this area, the ongoing clinical trials of immune-based combination therapies, as well as novel immunotherapy strategies such as chimeric antigen receptor T cells, personalized neoantigen vaccines, oncolytic viruses, and bispecific antibodies.

Development and Validation of a Novel Nomogram Integrated with Hypoxic and Lactate Metabolic Characteristics for Prognosis Prediction in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Accumulating evidence indicates that hypoxia and lactate metabolism play critical roles in tumor progression and therapeutic efficacy. This study aimed to construct a hypoxia- and lactate metabolism-related prognostic model (HLPM) to evaluate survival and treatment responses for HCC patients and develop a nomogram integrated with HLPM and clinical characteristics for prognosis prediction in HCC.

Methods

Expression profile and clinical data of HCC were obtained from TCGA and ICGC databases. The univariate, LASSO and stepwise multivariate Cox analyses were used to identify the hypoxia- and lactate metabolism-related biomarkers, whose expression levels were then validated in 14 pairs tissue samples and single-cell RNA sequencing dataset. Kaplan-Meier survival curves were utilized to assess the prognostic values of biomarkers or models. Analyses of ImmuCellAI, TIDE and drug sensitivity were conducted to evaluate the therapeutic responses of patients. Furthermore, the nomogram integrated with hypoxic and lactate metabolic characteristics was established through univariate and multivariate Cox analyses. ROC curves, C-index, and calibration curves were depicted to evaluate the performance of the nomogram.

Results

Five hypoxia- and lactate metabolism-related biomarkers (KIF20A, IRAK1, ADM, PPARGC1A and EPO) were used to construct HLPM. The expression of five prognostic biomarkers was validated in 14 pairs tissue samples and single-cell RNA sequencing dataset. Analyses of ImmuCellAI, TIDE and drug sensitivity implied that patients with low-risk score were more sensitive to immunotherapy and major chemotherapeutic agents. The nomogram that contained age, histological grade and risk score of HLPM was developed and exhibited a better capacity in prognosis prediction than HLPM only.

Conclusion

A novel nomogram integrated with hypoxic and lactate metabolic characteristics was developed and validated for prognosis prediction in HCC, providing insight into personalized decision-making in clinical management.

Deficiency in SLC25A15, a hypoxia-responsive gene, promotes hepatocellular carcinoma by reprogramming glutamine metabolism

BACKGROUND & AIMS

The role of solute carrier family 25 member 15 (SLC25A15), a critical component of the urea cycle, in hepatocellular carcinoma (HCC) progression remains poorly understood. This study investigated the impact of SLC25A15 on HCC progression and its mechanisms.

METHODS

We systematically investigated the function of SLC25A15 in HCC progression using large-scale data mining and cell, animal, and organoid models. Furthermore, we analyzed its involvement in reprogramming glutamine metabolism.

RESULTS

SLC25A15 expression was significantly decreased in HCC tissues, and patients with low SLC25A15 levels had a poorer prognosis. Hypoxia-exposed HCC cells or tissues had lower SLC25A15 expression. A positive correlation between HNF4A, a transcription factor suppressed by hypoxia, and SLC25A15 was observed in both HCC tissues and cells. Modulating HNF4A levels altered SLC25A15 mRNA levels. SLC25A15 upregulated SLC1A5, increasing glutamine uptake. The reactive metabolic pathway of glutamine was increased in SLC25A15-deficient HCC cells, providing energy for HCC progression through additional lipid synthesis. Ammonia accumulation due to low SLC25A15 levels suppressed the expression of OGDHL (oxoglutarate dehydrogenase L), a switch gene that mediates SLC25A15 deficiency-induced reprogramming of glutamine metabolism. SLC25A15-deficient HCC cells were more susceptible to glutamine deprivation and glutaminase inhibitors. Intervening in glutamine metabolism increased SLC25A15-deficient HCC cells' response to anti-PD-L1 treatment.

CONCLUSION

SLC25A15 is hypoxia-responsive in HCC, and low SLC25A15 levels result in glutamine reprogramming through SLC1A5 and OGDHL regulation, promoting HCC progression and regulating cell sensitivity to anti-PD-L1. Interrupting the glutamine-derived energy supply is a potential therapeutic strategy for treating SLC25A15-deficient HCC.

IMPACT AND IMPLICATIONS

We first demonstrated the tumor suppressor role of solute carrier family 25 member 15 (SLC25A15) in hepatocellular carcinoma (HCC) and showed that its deficiency leads to reprogramming of glutamine metabolism to promote HCC development. SLC25A15 can serve as a potential biomarker to guide the development of precision therapeutic strategies aimed at targeting glutamine deprivation. Furthermore, we highlight that the use of an inhibitor of glutamine utilization can enhance the sensitivity of low SLC25A15 HCC to anti-PD-L1 therapy.

Combined Administration of Escitalopram Oxalate and Nivolumab Exhibits Synergistic Growth-Inhibitory Effects on Liver Cancer Cells through Inducing Apoptosis

Liver cancer is one of the most lethal malignant cancers worldwide. However, the therapeutic options for advanced liver cancers are limited and reveal scant efficacy. The current study investigated the effects of nivolumab (Niv) and escitalopram oxalate (Esc) in combination on proliferation of liver cancer cells both in vitro and in vivo. Significantly decreased viability of HepG2 cells that were treated with Esc or Niv was observed in a dose-dependent manner at 24 h, 48 h, and 72 h. Administration of Esc (50 μM) + Niv (20 μM), Esc (75 μM) + Niv (5 μM), and Esc (75 μM) + Niv (20 μM) over 24 h exhibited synergistic effects, inhibiting the survival of HepG2 cells. Additionally, treatment with Esc (50 μM) + Niv (1 μM), Esc (50 μM) + Niv (20 μM), and Esc (75 μM) + Niv (20 μM) over 48 h exhibited synergistic effects, inhibiting the survival of HepG2 cells. Finally, treatment with Esc (50 μM) + Niv (1 μM), Esc (50 μM) + Niv (20 μM), and Esc (75 μM) + Niv (20 μM) for 72 h exhibited synergistic effects, inhibiting HepG2 survival. Com-pared with controls, HepG2 cells treated with Esc (50 μM) + Niv (20 μM) exhibited significantly increased sub-G1 portion and annexin-V signals. In a xenograft animal study, Niv (6.66 mg/kg) + Esc (2.5 mg/kg) significantly suppressed the growth of xenograft HepG2 tumors in nude mice. This study reports for the first time the synergistic effects of combined administration of Niv and Esc for inhibiting HepG2 cell proliferation, which may provide an alternative option for liver cancer treatment.

Comparison of diagnostic performance of AFP, DCP and two diagnostic models in hepatocellular carcinoma: a retrospective study

INTRODUCTION AND OBJECTIVES

Hepatocellular carcinoma (HCC) may be diagnosed using the GAAP and ASAP models; our goal was to verify and evaluate their diagnostic effectiveness compared to AFP, DCP, and AFP & DCP for both HCC and HCC caused by the hepatitis B virus (HBV).

PATIENTS AND METHODS

GAAP and ASAP models were validated and compared using a retrospective investigation of 938 patients from our hospital between July 2020 and July 2021.

RESULTS

Both the GAAP and ASAP models had better diagnostic efficacy than AFP, DCP, AFP & DCP. The GAAP model achieved better performance in section A for the detection of HCC and in section C for the detection of HBV-HCC than the ASAP model. The Hosmer-Lemeshow test showed that the GAAP and ASAP models were well-calibrated for the diagnoses of these two groups. To be more specific, the AUC of the GAAP model for HCC detection in section A was 0.862 [95% confidence interval (CI): 0.838-0.883], and that of the ASAP model was 0.850 [95% CI: 0.826-0.872]. The AUC of the GAAP model for HBV-HCC detection in section C was 0.897 [95% CI: 0.872-0.918], and that of the ASAP model was 0.878 [95% CI: 0.852-0.902].

CONCLUSIONS

The GAAP model was more accurate and reliable than the AFP, DCP, AFP and DCP, as well as the ASAP model in section A for the detection of HCC and in section C for the detection of HBV-HCC.

Sirolimus improves the prognosis of liver recipients with hepatocellular carcinoma: A single-center experience

BACKGROUND

Tumor recurrence after liver transplantation (LT) for selective patients diagnosed with hepatocellular carcinoma (HCC) in the setting of cirrhosis is the greatest challenge effecting the prognosis of these patients. The aim of this study was to evaluate the efficacy of sirolimus on the prognosis for these recipients.

METHODS

The data from 193 consecutive HCC patients who had undergone LT from January 2015 to December 2019 were retrospectively analyzed. These patients were divided into the sirolimus group [patients took sirolimus combined with calcineurin inhibitors (CNIs) (n = 125)] and non-sirolimus group [patients took CNI-based therapy without sirolimus (n = 68)]. Recurrence-free survival (RFS) and overall survival (OS) were compared between the two groups. The prognostic factors and independent risk factors for RFS and OS were further evaluated.

RESULTS

Non-sirolimus was an independent risk factor for RFS (HR = 2.990; 95% CI: 1.050-8.470; P = 0.040) and OS (HR = 3.100; 95% CI: 1.190-8.000; P = 0.020). A higher proportion of patients beyond Hangzhou criteria was divided into the sirolimus group (69.6% vs. 80.9%, P = 0.030). Compared with the non-sirolimus group, the sirolimus group had significantly better RFS (P < 0.001) and OS (P < 0.001). Further subgroup analysis showed similar results.

CONCLUSIONS

This study demonstrated that sirolimus significantly decreased HCC recurrence and prolonged RFS and OS in LT patients with different stage of HCC.

The Tumor Microenvironment of Hepatocellular Carcinoma: Untying an Intricate Immunological Network

HCC, the most prevalent form of primary liver cancer, is prototypically an inflammation-driven cancer developing after years of inflammatory insults. Consequently, the hepatic microenvironment is a site of complex immunological activities. Moreover, the tolerogenic nature of the liver can act as a barrier to anti-tumor immunity, fostering cancer progression and resistance to immunotherapies based on immune checkpoint inhibitors (ICB). In addition to being a site of primary carcinogenesis, many cancer types have high tropism for the liver, and patients diagnosed with liver metastasis have a dismal prognosis. Therefore, understanding the immunological networks characterizing the tumor microenvironment (TME) of HCC will deepen our understanding of liver immunity, and it will underpin the dominant mechanisms controlling both spontaneous and therapy-induced anti-tumor immune responses. Herein, we discuss the contributions of the cellular and molecular components of the liver immune contexture during HCC onset and progression by underscoring how the balance between antagonistic immune responses can recast the properties of the TME and the response to ICB.

Oncogenic Wnt3a is a promising sensitive biomarker for monitoring hepatocarcinogenesis

BACKGROUND

The effective treatment for hepatocellular carcinoma (HCC) depends on early diagnosis. Previously, the abnormal expression of Wnt3a as the key signaling molecule in the Wnt/β-catenin pathway was found in HCC cells and could be released into the circulation. In this study, we used rat model of hepatocarcinogenesis to dynamically investigate the alteration of oncogenic Wnt3a and to explore its early monitor value for HCC.

METHODS

Sprague-Dawley rats (SD) were fed with diet 2-fluorenylacetamide (2-FAA, 0.05%) for inducing hepatocarcinogenesis, and grouped based on liver morphological alteration by Hematoxylin & Eosin (H&E) staining; rats fed with normal chow were used as normal control (NC). Total RNA and protein were purified from rat livers. Differently expressed genes (DEGs) or Wnt3a mRNA, cellular distribution, and Wnt3a protein levels were analyzed by whole genome microarray with signal logarithm ratio (SLR log₂^cy5/cy3), immunohistochemistry, and enzyme-linked immunosorbent assay, respectively.

RESULTS

Models of rat hepatocarcinogenesis were successfully established based on liver histopathological H&E staining. Rats were divided into the cell degeneration (rDeg), precancerosis (rPre-C) and HCC (rHCC) groups. Total numbers of the up- and down-regulated DEGs with SLR ≥ 8 were 55 and 48 in the rDeg group, 268 and 57 in the rPre-C group, and 312 and 201 in the rHCC group, respectively. Significantly altered genes were involved in cell proliferation, signal transduction, tumor metastasis, and apoptosis. Compared with the NC group, Wnt3a mRNA was increased by 4.6 folds (P < 0.001) in the rDeg group, 7.4 folds (P < 0.001) in the rPre-C group, and 10.4 folds (P < 0.001) in the rHCC group; the positive rates of liver Wnt3a were 66.7% (P = 0.001) in the rDeg group, 100% (P < 0.001) in the rPre-C group, and 100% (P < 0.001) in the rHCC group, respectively. Also, there were significant differences of liver Wnt3a (P < 0.001) or serum Wnt3a (P < 0.001) among different groups.

CONCLUSIONS

Overexpression of Wnt3a was associated with rat hepatocarcinogenesis and it should be expected to be a promising monitoring biomarker for HCC occurrence at early stage.