APRIL, BCMA and TACI proteins are abnormally expressed in non-small cell lung cancer

Mechanisms for resistance to BCMA-targeted immunotherapies in multiple myeloma

Multiple myeloma (MM) remains incurable and patients eventually face the relapse/refractory dilemma. B cell maturation antigen (BCMA)-targeted immunotherapeutic approaches have shown great effectiveness in patients with relapsed/refractory MM, mainly including chimeric antigen receptor T cells (CAR-T), bispecific T cell engagers (TCEs), and antibody-drug conjugates (ADCs). However, their impact on long-term survival remains to be determined. Nonetheless, resistance to these novel therapies is still inevitable, raising a challenge that we have never met in both laboratory research and clinical practice. In this scenario, the investigation aiming to enhance and prolong the anti-MM activity of BCMA-targeted therapies has been expanding rapidly. Despite considerable uncertainty in our understanding of the mechanisms for their resistance, they have mainly been attributed to antigen-dependency, T cell-driven factors, and (immune) tumor microenvironment. In this review, we summarize the current understanding of the mechanisms for resistance to BCMA-targeted immunotherapies and discuss potential strategies for overcoming it.

The immune cells have complex causal regulation effects on cancers

BACKGROUND

There was a large body of evidence linking immune cells to cancer risk. However, the causal relationship between immune cells, cancer, and what genes play an important role is unclear.

METHODS

In this study, we performed comprehensive two-sample Mendelian randomization analysis (TSMR) to determine the causal relationship between immune cells and common cancers. We also performed Multimarker Analysis of Genomic Annotation (MAGMA) on immune cells causally associated with cancer to identify their relevant genes and used data summary-based MR (SMR) analysis to investigate the causal relationship between their gene expression, methylation, and cancer, and further used drug prediction and molecular docking to validate the medicinal value of the targets. Finally, reverse TSMR analysis was performed on cancer and immune cells to rule out reverse causality.

RESULTS

After FDR correction (PFDR < 0.05), the results showed that 2 immune cells were associated with lung cancer risk, and 1 immune cell was significantly associated with pancreatic cancer risk. The expression of OSBPL10, CHD4, SMDT1, PHETA2, and NAGA was positively and causally related to the risk of lung cancer by SMR analysis and HEIDI test. We also found that increased expression of ANP32E decreased the risk of pancreatic cancer and that the methylation level of OSBPL10, CHD4, SULF2, CENPM, and CYP2D6 had a causal association with lung cancer. The methylation level of FCGR3A was causally associated with pancreatic cancer. The results of molecular docking indicated a strong affinity between the drugs and proteins that possessed existing structural information.

CONCLUSION

This data-driven Mendelian randomization (MR) study demonstrates the causal role of immune cells in cancers. In addition, this study identifies candidate genes that may be potential anti-cancer drug targets.

Immunomodulatory effects of BAFF and APRIL cytokines in post-pulmonary infection lung cancer: Implications for drug resistance and progression

Lung cancer is a complicated and challenging disease and is one of the most common causes of cancer-related mortality worldwide. Within the lung microenvironment, specific cytokines, including the B cell activation factor (BAFF) and the A proliferation-inducing ligand (APRIL), are produce by various cells, notably airway epithelial cells, in response allergic inflammation or pulmonary infection. These cytokines play a critical role in maintaining local immune responses and fostering the survival of immune cells. The BAFF and APRIL system have been connected in a range of malignancies and have shown their potential in inducing drug resistance and promoting cancer progression. This review highlights recent studies on the involvement of BAFF and APRIL in various cancers, focusing mainly on their role in lung cancer, and discusses the possibility of these molecules in contributing to drug resistance and cancer progression following pulmonary infection. We suggest consideration the targeting BAFF and APRIL or their respective receptors as promising novel therapies for effective treatment of lung cancer, especially post pulmonary infection. However, it remains important to conduct further investigations to fully elucidate the precise mechanisms underlying how the BAFF and APRIL systems enhance cancer survival and drug resistance subsequent pulmonary infections.

The BAFF-APRIL System in Cancer

B cell-activating factor (BAFF; also known as CD257, TNFSF13B, BLyS) and a proliferation-inducing ligand (APRIL; also known as CD256, TNFSF13) belong to the tumor necrosis factor (TNF) family. BAFF was initially discovered as a B-cell survival factor, whereas APRIL was first identified as a protein highly expressed in various cancers. These discoveries were followed by over two decades of extensive research effort, which identified overlapping signaling cascades between BAFF and APRIL, controlling immune homeostasis in health and driving pathogenesis in autoimmunity and cancer, the latter being the focus of this review. High levels of BAFF, APRIL, and their receptors have been detected in different cancers and found to be associated with disease severity and treatment response. Here, we have summarized the role of the BAFF-APRIL system in immune cell differentiation and immune tolerance and detailed its pathogenic functions in hematological and solid cancers. We also highlight the emerging therapeutics targeting the BAFF-APRIL system in different cancer types.

Role of the APRIL molecule in solid tumors

The APRIL molecule, produced by immune cells, their precursors, and cancer cells, is one of the important factors that influences the process of survival and proliferation of cancer cells. In the present review, we summarize the current knowledge on the effects of APRIL on human cancer development and develop a scheme demonstrating the mechanism of the action of APRIL on solid tumors. Understanding the effects of APRIL, including the intracellular signal transduction pathway, may be key for the use of this protein as a biomarker of the cancer process. The correlations observed between APRIL levels and cancer parameters (e.g., disease stage and presence of malignant phenotypes) indicate that APRIL may play an important role, not only in the diagnostic process, but also as a therapeutic target in various cancers.

The effects of BAFF and APRIL signaling on non-small cell lung cancer cell proliferation and invasiveness

Lung cancer represents the most common type of human malignancy and is the main cause of cancer-associated mortality worldwide. To improve the effectiveness of treatment strategies, a better understanding of the mechanisms of cancer progression and invasiveness is required. Recently, B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL), two relatively newly described cytokines belonging to the tumor necrosis factor superfamily, have been shown to play a role in cancer progression. However, at present, the effects of both cytokines on lung cancer cells remain unclear. The present study aimed therefore to understand the direct effects of BAFF and APRIL on non-small cell lung cancer (NSCLC) progression. To do so, reverse transcription quantitative PCR and western blotting were used to evaluate whether A549 and H2030 NSCLC cells express receptors for both BAFF and APRIL. The results demonstrated that both investigated cell lines expressed BAFF-R (receptor specific to BAFF only) and transmembrane activator and CAML interactor (TACI; shared receptor for both cytokines). In addition, functional experiments were performed to determine the effects of BAFF and APRIL stimulation on cancer cell viability. The results demonstrated no direct effects of BAFF and APRIL on NSCLC cell proliferation and invasiveness. In summary, the present study demonstrated that NSCLC cells possess the ability to respond directly to both BAFF and APRIL. However, activation of BAFF-R and TACI signaling in cancer cells did not increase the proliferative capacity and invasiveness. Further investigation is thus required to better understand the role of BAFF and APRIL on the progression of NSCLC.

Exploring the role of BAFF as biomarker in the detection of uveal melanoma metastases

PURPOSE

While B-cell activating factor (BAFF) was identified to promote the invasion in other malignancies, its role in the progression of uveal melanoma (UM) still remains unexplored. Here, we analysed the serum level of BAFF in UM patients with regard to its significance as biomarker for the metastases.

METHODS

In this retrospective study, serum BAFF levels in 173 UM patients (36 with metastases and 137 without), and 23 healthy controls were measured with a multiplexed sandwich ELISA system and then correlated with clinicopathological characteristics such as primary tumor size, tumor location, histological cell type, sex, cancer stage, cytogenetic alterations of chromosome 3, and the metastatic burden. Immunohistochemical staining of 50 UM tissue specimens was also performed to evaluate the expression of BAFF and its receptors BAFF-R and TACI.

RESULTS

The metastatic patients were identified to have significantly higher serum BAFF levels (mean ± SD, 1520.8 ± 1182.1 pg/ml) than those without metastases (950.4 ± 494.6 pg/ml) and controls (810.3 ± 140.5 pg/ml). While no distinctions were detected with regard to tumor location, histological cell type, gender, and monosomy 3, the patients in cancer stages II, III, and IV displayed higher serum BAFF levels than those in stage I. The serum BAFF level was significantly correlated with the metastatic burden. The serum BAFF level of 1120 pg/ml was identified to have the best performance for distinguishing the metastatic patients from non-metastatic patients. In the kinetic study, we noticed that 20.8% of the analysed patients already demonstrated elevated serum BAFF concentrations before the clinical diagnosis of metastases. Positive BAFF staining was detected in the cytoplasm of single tumor cells (in 13 specimens), macrophages (in 12 specimens), and tumor-infiltrating lymphocytes (TILs) (in 13 specimens). The expressions of BAFF-R and TACI were also observed in 17 and 36 of the 50 tested UM specimens, respectively.

CONCLUSIONS

Our study first suggests that BAFF might be a promising serum marker for the detection of UM metastases.

Selective targeting of multiple myeloma by B cell maturation antigen (BCMA)-specific central memory CD8+ cytotoxic T lymphocytes: immunotherapeutic application in vaccination and adoptive immunotherapy

To expand the breadth and extent of current multiple myeloma (MM)-specific immunotherapy, we have identified various antigens on CD138⁺ tumor cells from newly diagnosed MM patients (n = 616) and confirmed B-cell maturation antigen (BCMA) as a key myeloma-associated antigen. The aim of this study is to target the BCMA, which promotes MM cell growth and survival, by generating BCMA-specific memory CD8⁺ CTL that mediate effective and long-lasting immunity against MM. Here we report the identification of novel engineered peptides specific to BCMA, BCMA_72-80 (YLMFLLRKI), and BCMA_54-62 (YILWTCLGL), which display improved affinity/stability to HLA-A2 compared to their native peptides and induce highly functional BCMA-specific CTL with increased activation (CD38, CD69) and co-stimulatory (CD40L, OX40, GITR) molecule expression. Importantly, the heteroclitic BCMA_72-80 specific CTL demonstrated poly-functional Th1-specific immune activities [IFN-γ/IL-2/TNF-α production, proliferation, cytotoxicity] against MM, which were correlated with expansion of Tetramer⁺ and memory CD8⁺ CTL. Additionally, heteroclitic BCMA_72-80 specific CTL treated with anti-OX40 (immune agonist) or anti-LAG-3 (checkpoint inhibitor) display increased immune function, mainly by central memory CTL. These results provide the framework for clinical application of heteroclitic BCMA_72-80 peptide, alone and in combination with anti-LAG3 and/or anti-OX40 therapy, in vaccination and/or adoptive immunotherapeutic strategies to generate long-lasting anti-tumor immunity in patients with MM or other BCMA expressing tumors.

Prognostic Significance of Serum BAFF, APRIL, TACI and BCMA Levels in Chronic Lymphocytic Leukemia

As chronic lymphocytic leukemia (CLL) has a variable disease course, novel prognostic markers and risk assessment models are being developed in order to identify high-risk patients who may need early treatment. The two tumor necrosis factor family proteins BAFF and APRIL and their receptors BAFF-R, TACI and BCMA are considered to play a critical role in the survival of normal B cells. In order to highlight the pathophysiological role of this complicated biological network, we aimed to analyze the potential prognostic effects of BAFF, APRIL, TACI and BCMA in CLL patients. We investigated the prognostic impact of serum BCMA, TACI, BAFF and APRIL levels in 129 newly diagnosed CLL patients [median age: 64 (39-88) years; male/female: 85/44]. Serum BAFF, TACI and BCMA levels were significantly lower in the patient group compared to the control group (p < 0.001), while serum APRIL level did not differ significantly between two groups (p > 0.05). Serum BCMA [(p = 0.029; r = 0.208)] and TACI levels [(p = 0.011; r = 0.241)] were positively correlated with serum free light chain ratio. Serum BAFF [(p = 0.008; r = - 0.236)] and BCMA [(p = 0.042; r = - 0.183)] levels were negatively correlated with Rai stage. Overall survival (OS) was relatively better in patients with low serum BAFF levels [60 (1-187) months vs 39.5 (0-256) months; p = 0.063]. Probability of OS was higher in patients with low BAFF levels when compared to patients with normal levels, without statistical significance (53.6% vs 23.6%; p > 0.05). Large prospective studies are needed to validate the prognostic role of this essential biological pathway in CLL.

Methylation Signature Genes Identification of the Lung Squamous Cell Carcinoma Occurrence and Recognition Research

DNA methylation (DNAm) is one of the most important epigenetic event effecting gene expression, and aberrant DNAm has been implicated in the initiation and progression of human cancers. To identify methylation (ME) signature genes for the pathogenesis of lung squamous cell carcinoma (LUSC), the pattern recognition method was used to analyze the genome-wide gene ME data, which were collected from the LUSC normal and cancer stage I samples in The Cancer Genome Atlas project database. A total of 102 ME signature genes were identified by means of a combination of statistical methods such as correlation, analysis of variance, and Elastic Net. The accuracy and specificity are all above 99%, sensitivity is 100%, and Matthews correlation coefficient is higher than 0.99 through the machine learning method modeling, which are higher than the previous study. The Kyoto Encyclopedia of Genes and Genomes pathway analysis and Gene Ontology enrichment analysis indicated the highly related relationship among these genes. They also indicated the immediate relationship between our signature genes and the occurrence of LUSC, which is very important to the understanding of its mechanism and to the development of new targeted therapy.

CAR T cell therapy for multiple myeloma: where are we now and where are we headed?

While recent progress has been made in the management of multiple myeloma, it remains a highly fatal malignancy especially among patients with relapsed-refractory disease. Immunotherapy with adoptive T cells targeting myeloma-associated antigens are at various stages of development and have brought about a new hope for cure. This is a review on the emerging field of adoptively transferred engineered T cell based approaches, with an in-depth focus on chimeric antigen receptors (CAR) targeting multiple myeloma. The recent results from CAR T cells targeting B cell maturation antigen are encouraging but eventual resistance to the CAR T cell therapies remain problematic. With newer approaches in therapies for multiple myeloma, the role of transplantation is evolved to form a platform for T cell therapies.