The Biofunctional Effects of Mesima as a Radiosensitizer for Hepatocellular Carcinoma

Phellinus linteus activates Treg cells via FAK to promote M2 macrophage polarization in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent malignant tumor worldwide. Within HCC's tumor microenvironment, focal adhesion kinase (FAK) plays a critical role. Regulatory T cells (Treg) modulate the polarization of tumor-associated macrophages , but the relationship between FAK, Treg cells, and macrophages remains underexplored. Phellinus linteus (PL) shows promise as a treatment for HCC due to its pharmacological effects. This study aimed to explore the relationship between FAK and Treg-macrophages and to assess whether PL could exert a protective effect through the FAK process in HCC. Initially, C57BL/6-FAK-/- tumor-bearing mice were utilized to demonstrate that FAK stimulates HCC tumor development. High dosages (200 μM) of FAK and the FAK activator ZINC40099027 led to an increase in Treg (CD4+CD25+) cells, a decrease in M1 macrophages (F4/80+CD16/32+, IL-12, IL-2, iNOS), and an increase in M2 macrophages (F4/80+CD206+, IL-4, IL-10, Arg1, TGF-β1). Additionally, FAK was found to encourage cell proliferation, migration, invasion, and epithelial-mesenchymal transition while inhibiting apoptosis in HepG2 and SMMC7721 cells. These effects were mediated by the PI3K/AKT1/Janus Kinase (JAK)/ signal transducer and activator of transcription 3 (STAT3), and mitogen-activated protein kinase (p38 MAPK)/Jun N-terminal Kinase (JNK) signaling pathways. Furthermore, PL exhibited a potent antitumor effect in vivo in a dose-dependent manner, reducing FAK, Treg cells, and M2 macrophages, while increasing M1 macrophages. This effect was achieved through the inhibition of the PI3K/AKT/JAK/STAT3, and p38/JNK pathways. Overall, our findings suggest that FAK promotes HCC via Treg cells that polarize macrophages toward the M2 type through specific signaling pathways. PL, acting through FAK, could be a protective therapy against HCC.

Salicylic acid promotes terpenoid synthesis in the fungi Sanghuangporus baumii

Sanghuangporus baumii is a medicinal fungi with anti-inflammatory, liver protection and antitumour effects. Terpenoids are one of the main medicinal ingredients of S. baumii. However, terpenoid production by wild-type S. baumii cannot meet the market demand, which affects its application in medical care. Therefore, exploring how to increase terpenoid content in S. baumii is a promising path in this research field. Salicylic acid (SA) is a secondary metabolite. In this study, a concentration of 350 μmol/L SA was added into fungal cultivations for 2 and 4 days, and then the transcriptome and metabolome of untreated mycelia and treated with SA were analysed. The expression of some genes in the terpenoids biosynthesis pathway increased in SA-induced cultivations, and the content of isopentenyl pyrophosphate (IPP) and geranylgeranyl-PP (GGPP) increased significantly as well as the contents of triterpenoids, diterpenoids, sesquiterpenoids and carotenoids. The gene FPS was considered to be a key gene regulating terpenoid biosynthesis. Therefore, FPS was overexpressed in S. baumii by Agrobacterium tumefaciens-mediated genetic transformation. The gene FPS and its downstream gene (LS) expression levels were confirmed to be increased in the FPS overexpressing transformant, and terpenoid content was 36.98% higher than that of the wild-type strain in the evaluated cultivation conditions.

Synergistic radiosensitizing effect of BR101801, a specific DNA-dependent protein kinase inhibitor, in various human solid cancer cells and xenografts

DNA-dependent protein kinase (DNA-PK), an essential component of the non-homologous end-joining (NHEJ) repair pathway, plays an important role in DNA damage repair (DDR). Therefore, DNA-PK inhibition is a promising approach for overcoming radiotherapy or chemotherapy resistance in cancers. In this study, we demonstrated that BR101801, a potent DNA-PK inhibitor, acted as an effective radiosensitizer in various human solid cancer cells and an in vivo xenograft model. Overall, BR101801 strongly elevated ionizing radiation (IR)-induced genomic instability via induction of cell cycle G₂/M arrest, autophagic cell death, and impairment of DDR pathway in human solid cancer cells. Interestingly, BR101801 inhibited not only phosphorylation of DNA-PK catalytic subunit in NHEJ factors but also BRCA2 protein level in homologous recombination (HR) factors. In addition, combination BR101801 and IR suppressed tumor growth compared with IR alone by reducing phosphorylation of DNA-PK in human solid cancer xenografts. Our findings suggested that BR101801 is a selective DNA-PK inhibitor with a synergistic radiosensitizing effect in human solid cancers, providing evidence for clinical applications.

The In Vivo Radiosensitizing Effect of Magnolol on Tumor Growth of Hepatocellular Carcinoma

BACKGROUND/AIM

Radiation (RT) induced ERK/NF-κB in hepatocellular carcinoma (HCC) has been reported in our previous works; it weakens the toxicity of RT or triggers a radioresistance effect. Thus, combining RT with a suitable NF-κB inhibitor may sensitize HCC to RT. Magnolol, a bioactive compound, was known to have anti-inflammatory and anti-tumor functions. Here, we aimed to investigate whether magnolol may enhance anti-HCC efficacy of RT in vivo.

MATERIALS AND METHODS

We established a Hep3B bearing mouse to evaluate the efficacy of the combination treatment of magnolol and RT.

RESULTS

Most significantly, tumor volume and tumor weight inhibition was found in the combination group. Tumor immunohistochemistry staining also illustrated the suppression of RT-induced ERK/NF-κB-related proteins expression by magnolol. In addition, intrinsic apoptosis-related proteins, such as caspase-3 and -9, were markedly increased in the combination group.

CONCLUSION

Magnolol may effectively enhance anti-HCC ability of RT by downregulating the expression of ERK/NF-κB-related proteins and increasing the expression of apoptosis-related proteins.

CRISPR/Cas9 library screening uncovered methylated PKP2 as a critical driver of lung cancer radioresistance by stabilizing β-catenin

Radiation resistance is a major cause of lung cancer treatment failure. Armadillo (ARM) superfamily proteins participate in various fundamental cellular processes; however, whether ARM proteins regulate radiation resistance is not fully understood. Here, we used an unbiased CRISPR/Cas9 library screen and identified plakophilin 2 (PKP2), a member of the ARM superfamily of proteins, as a critical driver of radiation resistance in lung cancer. The PKP2 level was significantly higher after radiotherapy than before radiotherapy, and high PKP2 expression after radiotherapy predicted poor overall survival (OS) and postprogression survival (PPS). Mechanistically, mass spectrometry analysis identified that PKP2 was methylated at the arginine site and interacted with protein arginine methyltransferase 1 (PRMT1). Methylation of PKP2 by PRMT1 stabilized β-catenin by recruiting USP7, further inducing LIG4, a key DNA ligase in nonhomologous end-joining (NHEJ) repair. Concomitantly, PKP2-induced radioresistance depended on facilitating LIG4-mediated NHEJ repair in lung cancer. More strikingly, after exposure to irradiation, treatment with the PRMT1 inhibitor C-7280948 abolished PKP2-induced radioresistance, and C-7280948 is a potential radiosensitizer in lung cancer. In summary, our results demonstrate that targeting the PRMT1/PKP2/β-catenin/LIG4 pathway is an effective approach to overcome radiation resistance in lung cancer.

Centipedegrass extract enhances radiosensitivity in melanoma cells by inducing G2/M cell cycle phase arrest

Melanoma is aggressive, highly metastatic, and potentially fatal. In the case of patients with advanced melanoma, it is difficult to expect a good prognosis, since this cancer has low sensitivity to chemotherapy and radiation therapy. The use of natural ingredients may enhance existing therapies. Centipedegrass extract (CGE) which contains phenolic structures and C-glycosyl flavones, has been shown to have anti-inflammatory effects and anti-cancer effects. The purpose of this study was to evaluate the radio sensitizing effects of CGE in combination with ionizing radiation (IR). Two melanoma cell lines were exposed to IR after treatment with CGE at concentrations that were not toxic alone. The effects of CGE + IR on cell survival, cell cycle, and apoptotic cell death were examined using MTT and Muse® Cell Analyzer, and fluorescence microscopy. Molecular signaling mechanisms were explored by western blots. Our findings showed that co-treatment of CGE + IR reduced the survival of melanoma cells more than IR alone. Also, cell cycle arrest in CGE-treated cells was enhanced and these cells became more radiosensitive. CGE + IR increased apoptotic cell death more than IR alone. Western blot results showed that the effect of CGE + IR involved MAPKs (ERK1/2, p38, and JNK) pathway. Our study suggests that CGE + IR treatment enhanced radio-sensitization and cell death of melanoma cells via cell cycle arrest and the MAPKs pathway.

Stereotactic Radiotherapy for Hepatocellular Carcinoma, Radiosensitization Strategies and Radiation-Immunotherapy Combination

Simple Summary

Radiotherapy is rapidly turning into a crucial component of multidisciplinary treatment for liver cancer because many patients are not surgical treatment candidates. Thanks to technical developments, radiotherapy have achieved high precision treatments, making it possible to eliminate tumor cells without severe damage to the liver and other organs. Stereotactic Body Radiation Therapy is an advanced radiotherapy technique able to eradicate malignant tumors wherever they are located in properly selected patients. The best use of radiotherapy, the most fruitful radiotherapy strategy, and the best way to combine it with other treatments for liver cancer are largely unknown. Radiosensitizers, agents that can potentiate radiotherapy, could broaden the radiotherapeutic landscape. Radiotherapy potentiation can be achieved with diverse treatments, not only drugs but also nanoparticles. In order to clear up the performance of radiotherapy in liver cancer management in the future and the best ways to potentiate its effects, considerable medical research is needed.

Abstract

Stereotactic body radiotherapy (SBRT) is an emerging ablative modality for hepatocellular carcinoma (HCC). Most patients with HCC have advanced disease at the time of diagnosis, and therefore, are not candidates for definitive-intent therapies such as resection or transplantation. For this reason, various alternative local and regional therapies have been used to prevent disease progression, palliate symptoms, and delay liver failure. Stereotactic body radiation therapy is a non-invasive technique of delivering ablative doses of radiation to tumors while sparing normal or non-tumor hepatic tissue. Incorporation of SBRT in multidisciplinary HCC management is gradual, initially applied when other liver-directed therapies have failed or are contraindicated, and tried in combination with other locoregional or systemic therapies for more unfavorable conditions by more experienced teams. In order to improve SBRT therapeutic ratio, there has been much interest in augmenting the effect of radiation on tumors by combining it with chemotherapy, molecularly targeted therapeutics, nanoparticles, and immunotherapy. This review aims to synthesize available evidence to evaluate the clinical feasibility and efficacy of SBRT for HCC, and to explore novel radio-potentiation concepts by combining SBRT with novel therapeutics. It is expected that those approaches would result in improved therapeutic outcomes, even though many questions remain with regard to the optimal way to assemble treatments. Further trials are needed to evaluate and consolidate these promising therapies for HCC.