Optimization of cancer immunotherapy on the basis of programmed death ligand-1 distribution and function

NUAK1 acts as a novel regulator of PD-L1 via activating GSK-3β/β-catenin pathway in hepatocellular carcinoma

BACKGROUND

NUAK1 is associated with metastasis and drug resistance in hepatocellular carcinoma (HCC). However, little is known about the immune functions of NUAK1 in HCC. Therefore, the aim of this study was to elucidate the novel role of NUAK1 in facilitating immune evasion in HCC and to investigate the mechanisms underpinning this process.

METHOD

The levels of NUAK1 expression and the infiltration of CD8+ T cells were assessed in tumor tissues from HCC patients and mice xenograft model. HCC cell lines were used to validate the role of NUAK1 in regulating the transcription of PD-L1, the diethylnitrosamine-induced HCC model was established and the expression levels of NUAK1 and PD-L1 proteins in the rat livers were detected. Western blotting, immunofluorescence, real time PCR, and immunohistochemical staining were used to investigate the underlying mechanisms by which NUAK1 regulates PD-L1 expression in hepatocellular carcinoma.

RESULTS

NUAK1 expression was negatively correlated with CD8+ T cell infiltration in tumor tissues from HCC patients and mice xenograft model. Both gain and loss of functions have identified NUAK1 promoted PD-L1 expression at transcriptional level in HCC cells. The increased expression of NUAK1 and PD-L1 proteins were observed in the rat livers of diethylnitrosamine-induced HCC model. Moreover, overexpression of NUAK1 promotes GSK3β Ser9 phosphorylation, β-catenin expression and nuclear accumulation in HCC cells. By contrast, knockdown of NUAK1 has opposite effects. Inhibition of GSK3β activity significantly promoted β-catenin expression and PD-L1 expression in HCC cells. IHC analyses of tumor tissues from HCC patients suggested that the levels of p-GSK3β and β-catenin were positively correlated with NUAK1 expression. Knockdown of β-catenin also reversed NUAK1-mediated PD-L1 expression in HCC cells.

CONCLUSIONS

This study revealed a novel role for NUAK1, which promotes the transcriptional expression of PD-L1 by activating GSK3β/β-catenin signaling pathway, leading to immune escape of hepatocellular carcinoma. Registry and the registration no. of the study/trial: Not applicable.

Steven-Johnson Syndrome/Toxic Epidermal Necrolysis is Associated with PD-1/PD-L1 Inhibitors Usage: A Case Series

Aims/Background The increasing adoption of inhibitors of programmed cell death-1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1), in the treatment of multiple cancer types in China has started to garner broader attention due to the occurrence of immune-related adverse events (irAEs), especially life-threatening skin reactions such as Steven-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). Isolated case reports have described SJS/TEN associated with PD-1/PD-L1 inhibitors usage. In this paper, we presented a series of cases of SJS/TEN following the use of PD-1/PD-L1 inhibitors in a dermatology hospital located in Zhejiang Province of China in the past several years, summarizing characteristics of these cases and providing a reference of management. Methods We retrospectively reviewed all the medical records of inpatients diagnosed with SJS/TEN in the Hangzhou Third People's Hospital from 2012 to 2024. We analyzed and compared the situation of SJS/TEN onset, types of PD-1/PD-L1 inhibitors used, score of severity, laboratory findings, and essential therapies of the patients who had received PD-1/PD-L1. Results We identified 12 SJS/TEN patients who had been treated with PD1/PD-L1 inhibitors: sintilimab had been used in six patients; tislelizumab in two cases; toripalimab, keytruda and cadonilimab each in one case; and an unknown prescription in one case. The longest duration between the first PD-1/PD-L1 inhibitor dose and the SJS/TEN diagnosis recorded was nine months whereas the shortest was 11 days. Half of the selected patients received chemotherapy at the same time. More than two types of therapies were applied to the cases, except for two cases with mild SJS. Conclusion This study unveils a potential, under-recognized cause of SJS/TEN in the cancer patients after analyzing the cases of SJS/TEN in cancer patients with prior exposure to PD-1/PD-L1 inhibitors. This paper also provides clue about the prominent features of SJS/TEN aforesaid, offering insights on the effective management measures for optimizing clinical safety.

Role of ursolic acid in preventing gastrointestinal cancer: recent trends and future perspectives

Gastrointestinal malignancies are one of the major worldwide health concerns. In the present review, we have assessed the plausible therapeutic implication of Ursolic Acid (UA) against gastrointestinal cancer. By modulating several signaling pathways critical in cancer development, UA could offer anti-inflammatory, anti-proliferative, and anti-metastatic properties. However, being of low oral bioavailability and poor permeability, its clinical value is restricted. To deliver and protect the drug, liposomes and polymer micelles are two UA nanoformulations that can effectively increase medicine stability. The use of UA for treating cancers is safe and appropriate with low toxicity characteristics and a predictable pharmacokinetic profile. Although the bioavailability of UA is limited, its nanoformulations could emerge as an alternative to enhance its efficacy in treating GI cancers. Further optimization and validation in the clinical trials are necessary. The combination of molecular profiling with nanoparticle-based drug delivery technologies holds the potential for bringing UA to maximum efficacy, looking for good prospects with GI cancer treatment.

Reducing PD-L1 Expression by Degraders and Downregulators as a Novel Strategy to Target the PD-1/PD-L1 Pathway

Targeting the programmed cell death protein-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway has evolved into one of the most promising strategies for tumor immunotherapy. Thus far, multiple monoclonal antibody drugs have been approved for treating a variety of tumors, while the development of small-molecule PD-1/PD-L1 inhibitors has lagged far behind, with only a few small-molecule inhibitors entering clinical trials. In addition to antibody drugs and small-molecule inhibitors, reducing the expression levels of PD-L1 has attracted extensive research interest as another promising strategy to target the PD-1/PD-L1 pathway. Herein, we analyze the structures and mechanisms of molecules that reduce PD-L1 expression and classify them as degraders and downregulators according to whether they directly bind to PD-L1. Moreover, we discuss the potential prospects for developing PD-L1-targeting drugs based on these molecules. It is hoped that this perspective will provide profound insights into the discovery of potent antitumor immunity drugs.

Advancing the PD-L1 CPS test in metastatic TNBC: Insights from pathologists and findings from a nationwide survey

Pembrolizumab has received approval as a first-line treatment for unresectable/metastatic triple-negative breast cancer (mTNBC) with a PD-L1 combined positive score (CPS) of ≥ 10. However, assessing CPS in mTNBC poses challenges. Firstly, it represents a novel analysis for breast pathologists. Secondly, the heterogeneity of PD-L1 expression in mTNBC further complicates the assessment. Lastly, the lack of standardized assays and staining platforms adds to the complexity. In KEYNOTE trials, PD-L1 expression was evaluated using the IHC 22C3 pharmDx kit as a companion diagnostic test. However, both the 22C3 pharmDx and VENTANA PD-L1 (SP263) assays are validated for CPS assessment. Consequently, assay-platform choice, staining conditions, and scoring methods can significantly impact the testing outcomes. This consensus paper aims to discuss the intricacies of PD-L1 CPS testing in mTNBC and provide practical recommendations for pathologists. Additionally, we present findings from a nationwide Italian survey elucidating the state-of-the-art in PD-L1 CPS testing in mTNBC.

Bispecific antibody targeting TGF-β and PD-L1 for synergistic cancer immunotherapy

The PD-1/PD-L1 signaling pathway plays a crucial role in cancer immune evasion, and the use of anti-PD-1/PD-L1 antibodies represents a significant milestone in cancer immunotherapy. However, the low response rate observed in unselected patients and the development of therapeutic resistance remain major obstacles to their clinical application. Accumulating studies showed that overexpressed TGF-β is another immunosuppressive factor apart from traditional immune checkpoints. Actually, the effects of PD-1 and TGF-β pathways are independent and interactive, which work together contributing to the immune evasion of cancer cell. It has been verified that blocking TGF-β and PD-L1 simultaneously could enhance the efficacy of PD-L1 monoclonal antibody and overcome its treatment resistance. Based on the bispecific antibody or fusion protein technology, multiple bispecific and bifunctional antibodies have been developed. In the preclinical and clinical studies, these updated antibodies exhibited potent anti-tumor activity, superior to anti-PD-1/PD-L1 monotherapies. In the review, we summarized the advances of bispecific antibodies targeting TGF-β and PD-L1 in cancer immunotherapy. We believe these next-generation immune checkpoint inhibitors would substantially alter the cancer treatment paradigm, especially in anti-PD-1/PD-L1-resistant patients.

Breast Cancer with Brain Metastasis: Molecular Insights and Clinical Management

Breast cancer is the most frequently diagnosed malignancy worldwide and the leading cause of cancer-related death among women. Brain metastases are a primary contributor to mortality, as they often go undetected until late stages due to their dormant nature. Moreover, the clinical management of brain metastases is complicated by the relevant issue of blood-brain barrier penetration. The molecular pathways involved in the formation, progression, and colonization of primary breast tumors and subsequent brain metastases are diverse, posing significant hurdles due to the heterogeneous nature of breast cancer subtypes. Despite advancements in primary breast cancer treatments, the prognosis for patients with brain metastases remains poor. In this review, we aim to highlight the biological mechanisms of breast cancer brain metastases by evaluating multi-step genetic pathways and to discuss currently available and emerging treatment strategies to propose a prospective overview of the management of this complex disease.