Hepatic Artery Embolization Enhances Expression of Programmed Cell Death 1 Ligand 1 in an Orthotopic Rat Hepatocellular Carcinoma Model: In Vivo and in Vitro Experimentation

Transarterial Embolization Enhances Programmed Cell Death Ligand 1 Expression and Influences CD8+T Lymphocytes Cytotoxicity in an Orthotopic Hepatocellular Carcinoma Rat Model

PURPOSE

To investigate the influence of transarterial embolization (TAE) on programmed cell death-ligand 1(PD-L1) expression and CD8+T tumour infiltrative lymphocyte cytotoxicity in the Sprague-Dawley (SD) rat model of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

An orthotopic HCC model was established in twenty SD rats treated with TAE (lipiodol, n = 10) or sham (normal saline, n = 10) using homologous N1S1 hepatoma cells. Rats were euthanized 1 week after embolization. Flow cytometry was used to assess the proportion of CD4+T, CD8+T and programmed cell death-1+(PD-1+) CD8+T lymphocytes in the spleens and tumours. Distribution of CD8+T, granzyme-B+CD8+T lymphocytes and PD-L1+ cells was assessed by immunohistochemistry (IHC) or multiplex IHC. p value < 0.05 was considered statistically significant.

RESULTS

The CD4/CD8 ratio and PD-1+CD8+ T lymphocytes exhibited higher values in TAE-treated tumours compared to sham-treated tumours (p = 0.021 and p = 0.071, respectively). Conversely, the number of CD8+T lymphocytes was decreased in TAE-treated tumours (p = 0.043), especially in the central region (p = 0.045). However, more CD8+T lymphocytes were found infiltrating the marginal region than central region in TAE-treated tumours (p = 0.046). The proportion of granzyme-B+CD8+T lymphocytes and the PD-L1 positive areas was elevated in tumours that treated with TAE (p all < 0.05). There was a negative correlation between PD-L1 expression and the number of infiltration of CD8+ T lymphocytes (p = 0.036).

CONCLUSIONS

Immune cells are distributed unevenly in the tumours after TAE. The intrinsic induction state of the tumour after embolization may be insufficient to elicit a maximal response to PD-1/PD-L1 inhibitors.

Transarterial Chemoembolization Combined with Tyrosine Kinase Inhibitors Plus Immune Checkpoint Inhibitors Versus Tyrosine Kinase Inhibitors Plus Immune Checkpoint Inhibitors in Unresectable Hepatocellular Carcinoma with First- or Lower-Order Portal Vein Tumor Thrombosis

PURPOSE

To compare the efficacy of transarterial chemoembolization (TACE) combined with tyrosine kinase inhibitors (TKIs) plus immune checkpoint inhibitors (ICIs) (TACE-TKI-ICI) versus TKIs plus ICIs (TKI-ICI) for unresectable hepatocellular carcinoma (HCC) with first- or lower-order portal vein tumor thrombosis (PVTT).

MATERIALS AND METHODS

A retrospective study was performed in HCC patients with first- or lower-order PVTT receiving TKIs (Lenvatinib or sorafenib) plus ICIs (camrelizumab, sintilimab, or atezolizumab) with or without TACE from four institutions between January 2019 and January 2022. Propensity score-based method was performed to minimize bias by confounding factors. Tumor response, progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were evaluated and compared between the two groups.

RESULTS

After inverse probability of treatment weighting, two balanced pseudopopulations were created: 106 patients in the TACE-TKI-ICI group and 109 patients in the TKI-ICI group. The objective response rate was higher in the TACE-TKI-ICI group (50.9% vs. 28.4%, P < 0.001). The median PFS and OS were significantly longer in the TACE-TKI-ICI group than in the TKI-ICI group (PFS: 9.1 vs. 5.0 months, P = 0.005; OS: 19.1 vs. 12.7 months, P = 0.002). In Cox regression, TACE-TKI-ICI treatment was an independent predictor of favorable OS. Treatment-related grade 3/4 AEs were comparable between the two groups (22.6% vs. 17.9%, P = 0.437).

CONCLUSION

TACE-TKI-ICI therapy contributed to better tumor control, PFS and OS than TKI-ICI therapy in unresectable HCC patients with first- or lower-order PVTT.

Role of Transarterial Chemoembolization in the Era of Tyrosine Kinase Inhibitor and Immune Checkpoint Inhibitor Combination Therapy for Unresectable Hepatocellular Carcinoma: A Retrospective Propensity Score Matched Analysis

RATIONALE AND OBJECTIVES: As an effective locoregional therapy, transarterial chemoembolization (TACE) can induce vascular endothelial growth factor and PD-1/PDL-1 upregulation, accompanied by a reduction in tumor burden. The present study aimed to compare the efficacy of TACE combined with tyrosine kinase inhibitors (TKIs) plus immune checkpoint inhibitors (ICIs) (TACE-TKI-ICIs) versus TKIs plus ICIs (TKI-ICIs) in patients with unresectable hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

The clinical data of 198 patients diagnosed with unresectable HCC who received a TKI (lenvatinib or sorafenib) plus an ICI (sintilimab or camrelizumab) with or without TACE were retrospectively reviewed between October 2019 and April 2022. Baseline characteristics of the TACE-TKI-ICI group and the TKI-ICI group were matched by propensity score matching in a 1:1 ratio. The tumor response, progression-free survival (PFS), and overall survival (OS) were evaluated and compared between the two groups.

RESULTS

After matching, 54 patients were enrolled in each group. The objective response rate (ORR) and disease control rate (DCR) were higher in the TACE-TKI-ICI group (ORR: 63.0% vs. 29.6%, P < 0.001; DCR: 85.2% vs. 53.7%, P < 0.001). The median PFS was significantly longer in the TACE-TKI-ICI group (9.9 vs. 5.8 months; P = 0.026). The median OS between the two groups also reached a significant difference (not reached vs. 18.5 months; P = 0.003).

CONCLUSION

In this retrospective study, the results indicated that the addition of TACE to TKI-ICI therapy could contribute to better tumor control, PFS, and OS benefits in patients with unresectable HCC.

Utility and predictive value of the CRAFITY score in advanced hepatocellular carcinoma treated with transarterial chemoembolization plus tyrosine kinase inhibitors and PD-1 inhibitor

BACKGROUND

The prognostic significance of the CRAFITY score (CRP and AFP in ImmunoTherapY) has been demonstrated in hepatocellular carcinoma (HCC) patients receiving immunotherapy. The purpose of this study was to investigate the utility and the predictive value of CRAFITY score in HCC after transarterial chemoembolization (TACE) in combination with tyrosine kinase inhibitors (TKIs) and immunotherapy.

MATERIALS AND METHODS

Data from patients with advanced HCC treated with TACE plus TKIs and PD-1 inhibitor from January 2019 to June 2022 were collected and analyzed retrospectively. Patients with AFP ≥ 100 ng/mL and those with CRP ≥ 1 mg/dL were assigned a CRAFITY score of 1 point. Patients were divided into three groups according to their CRAFITY score (CRAFITY-low, 0 points; CRAFITY-intermediate, 1 point; and CRAFITY-high, 2 points). The differences in overall survival (OS), progression-free survival (PFS) and adverse events (AEs) were compared among the three groups. Tumor response was evaluated at 3, 6 and 12 months after the first combination treatment. Risk factors for OS and PFS were assessed.

RESULTS

A total of 70 patients were included. The patients were assigned CRAFITY scores of 0 points (CRAFITY-low, n = 25 [35.71%]), 1 point (CRAFITY-intermediate, n = 29 [41.42%]), and 2 points (CRAFITY-high, n = 16 [22.81%]). Multivariate analysis showed that lower CRAFITY score was an independent factor for the improved OS (P =.045) and PFS (P <.001). TACE session was also associated with the OS (P =.048) in the multivariate analysis. The CRAFITY-low cohort achieved a higher objective response rate (ORR) at the 3-month evaluation of tumor response. However, there was no significant difference in ORR and disease control rate (DCR) observed at the 6-month follow-up. DCR showed a statistically significant difference among three groups during the 12-month follow-up period. The percentage of patients with protein urea was highest in the CRAFITY-high group. No significance differences were observed in grade ≥ 3 AEs in three groups.

CONCLUSION

The CRAFITY score is simple and could be useful for predicting treatment outcomes, tumor response and AEs of the HCC patients receiving TACE plus TKIs and PD-1 inhibitor therapy.

The current status and future of PD-L1 in liver cancer

The application of immunotherapy in tumor, especially immune checkpoint inhibitors (ICIs), has played an important role in the treatment of advanced unresectable liver cancer. However, the efficacy of ICIs varies greatly among different patients, which has aroused people's attention to the regulatory mechanism of programmed death ligand-1 (PD-L1) in the immune escape of liver cancer. PD-L1 is regulated by multiple levels and signaling pathways in hepatocellular carcinoma (HCC), including gene variation, epigenetic inheritance, transcriptional regulation, post-transcriptional regulation, and post-translational modification. More studies have also found that the high expression of PD-L1 may be the main factor affecting the immunotherapy of liver cancer. However, what is the difference of PD-L1 expressed by different types of cells in the microenvironment of HCC, and which type of cells expressed PD-L1 determines the effect of tumor immunotherapy remains unclear. Therefore, clarifying the regulatory mechanism of PD-L1 in liver cancer can provide more basis for liver cancer immunotherapy and combined immune treatment strategy. In addition to its well-known role in immune regulation, PD-L1 also plays a role in regulating cancer cell proliferation and promoting drug resistance of tumor cells, which will be reviewed in this paper. In addition, we also summarized the natural products and drugs that regulated the expression of PD-L1 in HCC.

Lenvatinib Mitigates Transarterial Embolization-Induced Polarization of Tumor-Associated Macrophages in a Rat Hepatocellular Carcinoma Model

PURPOSE

To investigate the effect of transarterial embolization (TAE) on macrophage polarization and the modulatory effect of lenvatinib when used in combination with TAE in a rat hepatocellular carcinoma model.

MATERIALS AND METHODS

A N1S1-bearing orthotopic rat model was subjected to TAE and administered 5 mg/kg of lenvatinib. CD8+, CD68+, and CD206+ cells were examined in 4 groups: sham (n = 5), lenvatinib (n = 5), TAE (n = 5), and combination of TAE and lenvatinib (n = 5). Transcriptome analysis was performed to assess gene expression related to macrophage polarization in the sham, TAE, and combination groups. An in vitro coculture experiment with bone marrow-derived macrophages was performed to identify lenvatinib target in macrophage polarization.

RESULTS

There were no significant differences in the number of CD8+ and CD68+ cells among the 4 groups. Tumor-associated macrophage positivity for CD206 was significantly higher in the TAE group (58.1 ± 20.9) than in the sham (11.2 ± 14.3; P < .001) and combination (27.1 ± 19.7; P = .003) groups. In the transcriptome analysis, compared with the genes in the sham group, 5 macrophage polarization-related genes, including St6gal1, were upregulated by more than 1.5 fold in the TAE group and downregulated by more than 1.5 fold in the combination group. The coculture experiment showed that lenvatinib did not affect macrophages but affected N1S1 cells, leading to macrophage polarization.

CONCLUSIONS

TAE-induced M2 macrophage polarization. Lenvatinib administration with TAE could reprogram macrophage polarization, improving tumor immune microenvironment.

PD-L1 and HIF-2α Upregulation in Head and Neck Paragangliomas after Embolization

Hypoxia activates pathways associated with tumor progression, metastatic spread, and alterations in the immune microenvironment leading to an immunosuppressive phenotype. In particular, the upregulation of PD-L1, a target for therapy with checkpoint inhibitors, is well-studied in several tumors. However, the relationship between hypoxia and PD-L1 regulation in pheochromocytomas and paragangliomas (PPGL), and especially in paragangliomas treated with embolization, is still largely unexplored. We investigated the expression of the hypoxia-marker HIF-2α and of PD-L1 in a PPGL-cohort with and without embolization as potential biomarkers that may predict the response to treatment with HIF-2α and checkpoint inhibitors. A total of 29 tumor samples from 25 patients who were operated at a single center were included and analyzed utilizing immunohistochemistry (IHC) for PD-L1 and HIF-2α. Embolization prior to surgery was performed in seven (24%) tumors. PD-L1 expression in tumor cells of head and neck paragangliomas (HNPGLs) receiving prior embolization (median PD-L1 positivity: 15%) was significantly higher as compared to PD-L1 expression in HNPGLs without prior embolization (median PD-L1 positivity: 0%) (p = 0.008). Consistently, significantly more HNPGLs with prior embolization were positive for HIF-2α (median nuclear HIF-2α positivity: 40%) as compared to HNPGLs without prior embolization (median nuclear HIF-2α positivity: 0%) (p = 0.016). Our results support the hypothesis that embolization with subsequent hypoxia leads to the upregulation of both PD-L1 and HIF-2α in HNPGLs, and could thus facilitate targeted treatment with HIF-2α and checkpoint inhibitors in the case of inoperable, locally advanced, or metastatic disease.

Nrf2-siRNA Enhanced the Anti-Tumor Effects of As2O3 in 5-Fluorouracil-Resistant Hepatocellular Carcinoma by Inhibiting HIF-1α/HSP70 Signaling

Purpose

Chemoresistance is a major factor contributing to the failure of cancer treatment. The conventional chemotherapy agent 5-fluorouracil (5-FU) has been used for cancer treatment for decades. However, its use is limited in the treatment of hepatocellular carcinoma (HCC) due to acquired resistance. Nrf2 (NF-E2-related factor 2) is known to be associated with drug resistance across a wide range of cancer types. Also, since arsenic trioxide (As₂O₃) showed antitumor effects on HCC, the purpose of this study was to determine whether As₂O₃ and Nrf2-siRNA could inhibit HCC synergistically.

Methods

We generated two separate 5-FU-resistant HCC cell lines (SNU-387/5-FU and Hep3B/5-FU). Western blotting was used to determine protein levels. An efficient lentiviral delivery system was used to establish stable knockdown or overexpression of Nrf2 and HIF-1α. In vitro and in vivo analyses of the effects of Nrf2 gene knockdown and As₂O₃ on 5-FU-resistant HCC cells were conducted.

Results

The expression of Nrf2 was higher in the 5-FU-resistant HCC cell lines than in the parental cell lines. When coupled with Nrf2 knockdown, As₂O₃ treatment significantly decreased 5-FU-resistant SNU-387 and Hep3B cell viability, migration, and invasion, inactivated HIF-1α/HSP70 signaling, inhibited anti-apoptotic B-cell lymphoma (Bcl-2) activity, and increased the expression of pro-apoptotic Bcl-2-associated X protein (BAX) along with caspase-3. The synergistic effect was also confirmed using a 5-FU-resistant Hep3B mouse xenograft model in vivo.

Conclusion

Nrf2 knockdown could improve the effect of As₂O₃ on reversing drug resistance in 5-FU-resistant HCC cells.

Safety and Efficacy of Transarterial Chemoembolization and Immune Checkpoint Inhibition with Camrelizumab for Treatment of Unresectable Hepatocellular Carcinoma

Background

The clinical outcomes of hepatocellular carcinoma (HCC) patients who receive transarterial chemoembolization (TACE) and immunotherapy are not well characterized. The present study evaluates the safety and efficacy of TACE in combination with immune checkpoint inhibitor treatment for unresectable HCC.

Methods

A retrospective analysis of 34 HCC patients who received TACE and treatment with the immune checkpoint inhibitor (ICI), Camrelizumab, between July 2019 and May 2021, was performed. This included 21 patients who developed progressive disease and eight who remained stable after several sessions of TACE, along with five patients who were initially diagnosed with advanced HCC. Adverse events (AEs), objective response rate (ORR) according to modified response evaluation criteria in solid tumors, progression-free survival (PFS), and overall survival (OS) were evaluated.

Results

The median follow-up from ICI initiation was 10.6 months (range: 2.4–25.0 months). Grade I/II and grade III/IV AEs from ICI treatment occurred in 20 (58.8%) and 2 patients (5.9%), respectively. Two to three months after ICI therapy, the ORR was 35.3% (12/34) and the median PFS and OS was 6.1 months (range: 1.1–19.3 months) and 13.3 months (range: 2.4–25.0 months), respectively.

Conclusion

TACE in combination with ICI could be a promising treatment approach for unresectable HCC patients.

The role of PD-L1 in the immune dysfunction that mediates hypoxia-induced multiple organ injury

Hypoxia is a pathological condition common to many diseases, although multiple organ injuries induced by hypoxia are often overlooked. There is increasing evidence to suggest that the hypoxic environment may activate innate immune cells and suppress adaptive immunity, further stimulating inflammation and inhibiting immunosurveillance. We found that dysfunctional immune regulation may aggravate hypoxia-induced tissue damage and contribute to secondary injury. Among the diverse mechanisms of hypoxia-induced immune dysfunction identified to date, the role of programmed death-ligand 1 (PD-L1) has recently attracted much attention. Besides leading to tumour immune evasion, PD-L1 has also been found to participate in the progression of the immune dysfunction which mediates hypoxia-induced multiple organ injury. In this review, we aimed to summarise the role of immune dysfunction in hypoxia-induced multiple organ injury, the effects of hypoxia on the cellular expression of PD-L1, and the effects of upregulated PD-L1 expression on immune regulation. Furthermore, we summarise the latest information pertaining to the involvement, diagnostic value, and therapeutic potential of immunosuppression induced by PD-L1 in various types of hypoxia-related diseases, including cancers, ischemic stroke, acute kidney injury, and obstructive sleep apnoea. Video Abstract.