Hepatocellular carcinoma (HCC) tumor microenvironment is more suppressive than colorectal cancer liver metastasis (CRLM) tumor microenvironment

Comprehensive structural investigation of a potent and selective CXCR4 antagonist via crosslink modification

Macrocyclization presents a valuable strategy for enhancing the pharmacokinetic and pharmacodynamic profiles of short bioactive peptides. The exploration of various macrocyclic characteristics, such as crosslinking tethers, ring size, and orientation, is generally conducted during the early stages of development. Herein, starting from a potent and selective C-X-C chemokine receptor 4 (CXCR4) cyclic heptapeptide antagonist mimicking the N-terminal region of CXCL12, we demonstrated that the disulfide bridge could be successfully replaced with a side-chain to side-chain lactam bond, which is commonly not enlisted among the conventional disulfide mimetics. An extensive investigation was carried out to explore the chemical space of the resulting peptides, including macrocyclization width, stereochemical configuration, and lactam orientation, all of which were correlated with biochemical activity. We identified a novel heptapeptide that fully replicates the pharmacological profile of the parent peptide on CXCR4, including its potency, selectivity, and antagonistic activity, while demonstrating enhanced stability in a reductive environment. At this stage, computational studies were instructed to shed light on how the lactam cyclization features influenced the overall structure of 21 and, in turn, its ability to interact with the receptor. We envisage that these findings can give new momentum to the use of lactam cyclization as a disulfide bond mimetic and contribute to the enhancement of the repertoire for peptide-based drug development, thereby paving the way for novel avenues in therapeutic innovation.

Multicompartment Polyion Complex Micelles Based on Triblock Polypept(o)ides Mediate Efficient siRNA Delivery to Cancer-Associated Fibroblasts for Antistromal Therapy of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent type of primary liver cancer and the third leading cause for cancer-related death worldwide. The tumor is difficult-to-treat due to its inherent resistance to chemotherapy. Antistromal therapy is a novel therapeutic approach, targeting cancer-associated fibroblasts (CAF) in the tumor microenvironment. CAF-derived microfibrillar-associated protein 5 (MFAP-5) is identified as a novel target for antistromal therapy of HCC with high translational relevance. Biocompatible polypept(o)ide-based polyion complex micelles (PICMs) constructed with a triblock copolymer composed of a cationic poly(l-lysine) complexing anti-MFAP-5 siRNA (siMFAP-5) via electrostatic interaction, a poly(γ-benzyl-l-glutamate) block loading cationic amphiphilic drug desloratatine (DES) via π-π interaction as endosomal escape enhancer and polysarcosine poly(N-methylglycine) for introducing stealth properties, are generated for siRNA delivery. Intravenous injection of siMFAP-5/DES PICMs significantly reduces the hepatic tumor burden in a syngeneic implantation model of HCC, with a superior MFAP-5 knockdown effect over siMFAP-5 PICMs or lipid nanoparticles. Transcriptome and histological analysis reveal that MFAP-5 knockdown inhibited CAF-related tumor vascularization, suggesting the anti-angiogenic effect of RNA interference therapy. In conclusion, multicompartment PICMs combining siMFAP-5 and DES in a single polypept(o)ide micelle induce a specific knockdown of MFAP-5 and demonstrate a potent antitumor efficacy (80% reduced tumor burden vs untreated control) in a clinically relevant HCC model.

Immunotherapy in liver cancer: overcoming the tolerogenic liver microenvironment

Liver cancer is a major global health concern, ranking among the top causes of cancer-related deaths worldwide. Despite advances in medical research, the prognosis for liver cancer remains poor, largely due to the inherent limitations of current therapies. Traditional treatments like surgery, radiation, and chemotherapy often fail to provide long-term remission and are associated with significant side effects. Immunotherapy has emerged as a promising avenue for cancer treatment, leveraging the body's immune system to target and destroy cancer cells. However, its application in liver cancer has been limited. One of the primary challenges is the liver's unique immune microenvironment, which can inhibit the effectiveness of immunotherapeutic agents. This immune microenvironment creates a barrier, leading to drug resistance and reducing the overall efficacy of treatment. Recent studies have focused on understanding the immunological landscape of liver cancer to develop strategies that can overcome these obstacles. By identifying the specific factors within the liver that contribute to immune suppression and drug resistance, researchers aim to enhance the effectiveness of immunotherapy. Prospective strategies include combining immunotherapy with other treatments, using targeted therapies to modulate the immune microenvironment, and developing new agents that can bypass or counteract the inhibitory mechanisms in the liver. These advancements hold promise for improving outcomes in liver cancer treatment.

Immune effect and prognosis of transcatheter arterial chemoembolization and tyrosine kinase inhibitors therapy in patients with hepatocellular carcinoma

BACKGROUND

The combination of transcatheter arterial chemoembolization (TACE) and tyrosine kinase inhibitors (TKIs) has shown broad prospects in prolonging the survival of patients with hepatocellular carcinoma (HCC). TACE and TKIs can affect the immune microenvironment in patients with HCC.

AIM

To determine the overall effects and differences between TACE and different TKIs combinations on the immune microenvironment.

METHODS

Data and immune cell profile test results from 213 HCC patients treated with TACE combined with apatinib, lenvatinib, sorafenib, or donafenib before and after 3 wk of treatment were collected. Monocytes were co-cultured with LM3 liver cancer cells, and their ability to inhibit cancer cell growth was analyzed using the MTT method and a nude mouse subcutaneous tumorigenesis experiment. Simulated combined therapy was done using an in situ liver cancer C57BL/6 male mouse model, and the immune response of tumor tissues was analyzed using immunohistochemistry.

RESULTS

Compared to before combination therapy, the proportion of programmed cell death protein 1 (PD-1)+ mononuclear cells and the number of CD4+ T cells decreased in the TACE + apatinib group, while the number of absolute count of CD4+ and CD8+ T cells increased in the TACE + lenvatinib group. Furthermore, the number of regulatory cells decreased in the TACE + donafenib group, whereas the number of CD8+ T and natural killer cells increased. Additionally, monocytes in the TACE combined with donafenib or lenvatinib groups had a stronger ability to inhibit cancer cell growth than those in the other groups. Combining TACE with donafenib or lenvatinib increased CD8+ T cell infiltration into the tumor tissue. In addition, the proportion of PD-1+ in CD8+ cells, absolute CD8+ T lymphocyte count, and regulatory T cells proportion were independent prognostic factors affecting the survival time of patients with HCC.

CONCLUSION

TACE, in combination with different TKIs, produces different immune responses. Specifically, TACE combined with donafenib or lenvatinib may induce strong anti-tumor immune responses.

Targeting CXCR4 impaired T regulatory function through PTEN in renal cancer patients

BACKGROUND

Tregs trafficking is controlled by CXCR4. In Renal Cell Carcinoma (RCC), the effect of the new CXCR4 antagonist, R54, was explored in peripheral blood (PB)-Tregs isolated from primary RCC patients.

METHODS

PB-Tregs were isolated from 77 RCC patients and 38 healthy donors (HDs). CFSE-T effector-Tregs suppression assay, IL-35, IFN-γ, IL-10, TGF-β1 secretion, and Nrp-1+Tregs frequency were evaluated. Tregs were characterised for CTLA-4, PD-1, CD40L, PTEN, CD25, TGF-β1, FOXP3, DNMT1 transcriptional profile. PTEN-pAKT signalling was evaluated in the presence of R54 and/or triciribine (TCB), an AKT inhibitor. Methylation of TSDR (Treg-Specific-Demethylated-Region) was conducted.

RESULTS

R54 impaired PB-RCC-Tregs function, reduced Nrp-1+Tregs frequency, the release of IL-35, IL-10, and TGF-β1, while increased IFN-γ Teff-secretion. The CXCR4 ligand, CXCL12, recruited CD25+PTEN+Tregs in RCC while R54 significantly reduced it. IL-2/PMA activates Tregs reducing pAKT+Tregs while R54 increases it. The AKT inhibitor, TCB, prevented the increase in pAKT+Tregs R54-mediated. Moreover, R54 significantly reduced FOXP3-TSDR demethylation with DNMT1 and FOXP3 downregulation.

CONCLUSION

R54 impairs Tregs function in primary RCC patients targeting PTEN/PI3K/AKT pathway, reducing TSDR demethylation and FOXP3 and DNMT1 expression. Thus, CXCR4 targeting is a strategy to inhibit Tregs activity in the RCC tumour microenvironment.

The Safety and Efficacy of Hepatic Arterial Infusion Chemotherapy Combined with PD-(L)1 Inhibitors and Molecular Targeted Therapies for the Treatment of Intermediate and Advanced Hepatocellular Carcinoma Unsuitable for Transarterial Chemoembolization

Objective

To investigate the efficacy and safety of hepatic arterial infusion chemotherapy (HAIC) combined with PD-(L)1 inhibitors and molecular targeted therapies (MTT) for intermediate and advanced HCC that are unsuitable for transarterial chemoembolization (TACE).

Methods

We conducted a retrospective analysis of data from patients with TACE-unsuitable HCC who were receiving triple therapy from January 2020 to December 2021 at two medical centers. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS), objective response rates (ORR), disease control rates (DCR), and incidence of adverse events (AEs).

Results

A total of 55 patients were enrolled in the study with median treatment periods of 4 and 6 for HAIC and PD-(L)1 inhibitors, respectively. The median OS and PFS were 15.0 and 10.0 months, respectively, with a median follow-up of 11.0 months (range: 4.0-27.5 months). According to the mRECIST criteria, the optimal ORR was 43.6% (24/55) and the DCR was 61.8% (34/55). The incidence of AEs was 58.2%, with grade 3 and above accounting for 20.0%; elevated AST (18.2%), hyperbilirubinemia (16.4%), and thrombocytopenia (16.4%) were most common. There were no treatment-related fatalities and all AEs were effectively managed. Multifactorial analysis showed that NLR > 3.82 (HR 2.380, 95% CI 1.116-2-5.079, P = 0.025), ECOG 1 (HR 2.906, 95% CI 1.373-6.154, P = 0.005), and extrahepatic metastases (HR 8.373, 95% CI 3.492-20.078, P < 0.001) were associated with the median OS.

Conclusion

Triple therapy with HAIC, PD-(L)1 inhibitors, and MTT was safe and effective for patients with intermediate and advanced HCC for TACE-unsuitability.