Lenalidomide Augments the Antitumor Activities of Eps8 Peptide-Specific Cytotoxic T Lymphocytes against Multiple Myeloma

EPS-8 regulates human malignant melanoma development by activating the Hedgehog pathway via degradation of Ptch1

BACKGROUND

The epidermal growth factor receptor pathway substrate 8 (EPS-8) is a tumor-associated antigen that is frequently overexpressed in various types of human solid tumors and is associated with aggressiveness and poor prognosis. The role of EPS-8 in cutaneous malignant melanoma and its potential mechanism remains unknown.

METHODS

EPS-8 expression, mutation immune infiltration, and the tumor microenvironment in melanoma were analyzed using various databases. Clinical samples were collected and melanoma cell viability, apoptosis and protein levels were detected using cell counting kit-8, colony formation, Hoechst 33258 staining, and Western blot. Meanwhile, xenograft tumor models in nude mice were produced to evaluate the effect of EPS-8 on malignant melanoma in vivo.

RESULTS

EPS-8 levels were highly expressed in melanoma and correlated with immune-infiltrating cells, immune-related scores, and immunotherapy. Additionally, in clinical malignant melanoma samples, the EPS-8 level was significantly higher in the malignant melanoma samples compared with adjacent normal tissue, and patients with a high expression of EPS-8 had significantly poor tumor differentiation and a high clinical stage. The overexpression of EPS-8 promoted the proliferation but inhibited the apoptosis of malignant melanoma cells. The knockdown of EPS-8 markedly inhibited the activation of the Hedgehog (Hh) pathway. Notably, the knockdown of Patched-1 (Ptch1) could attenuate the changes in proteins and mRNA level, cell proliferation, apoptosis, and tumor growth induced by the knockdown of EPS-8.

CONCLUSION

The overexpression of EPS-8 had impacts on the proliferation and apoptosis of cutaneous malignant melanoma cells. The degradation of Ptch1 contributed to the activation of the Hh pathway induced by EPS-8.

Anti‐angiogenic therapy enhances cancer immunotherapy: Mechanism and clinical application

Immunotherapy, specifically immune checkpoint inhibitors, is revolutionizing cancer treatment, achieving durable control of previously incurable or advanced tumors. However, only a certain group of patients exhibit effective responses to immunotherapy. Anti‐angiogenic therapy aims to block blood vessel growth in tumors by depriving them of essential nutrients and effectively impeding their growth. Emerging evidence shows that tumor vessels exhibit structural and functional abnormalities, resulting in an immunosuppressive microenvironment and poor response to immunotherapy. Both preclinical and clinical studies have used anti‐angiogenic agents to enhance the effectiveness of immunotherapy against cancer. In this review, we concentrate on the synergistic effect of anti‐angiogenic and immune therapies in cancer management, dissect the direct effects and underlying mechanisms of tumor vessels on recruiting and activating immune cells, and discuss the potential of anti‐angiogenic agents to improve the effectiveness of immunotherapy. Lastly, we outline challenges and opportunities for the anti‐angiogenic strategy to enhance immunotherapy. Considering the increasing approval of the combination of anti‐angiogenic and immune therapies in treating cancers, this comprehensive review would be timely and important.

The long multi-epitope peptide vaccine combined with adjuvants improved the therapeutic effects in a glioblastoma mouse model

Emerging data have suggested that single short peptides have limited success as a cancer vaccine; however, extending the short peptides into longer multi-epitope peptides overcame the immune tolerance and induced an immune response. Moreover, the combination of adjuvants such as lenalidomide and anti-programmed cell death protein 1 (PD1) with a peptide vaccine showed potential vaccine effects in previous studies. Therefore, the effects of a long multi-epitope peptide vaccine in combination with lenalidomide and anti-PD1 were analyzed in this study. Long multi-epitope peptides from two MHCI peptides (BIRC597-104 and EphA2682-689) and the pan-human leukocyte antigen-DR isotype (HLA-DR) binding epitope (PADRE) were synthesized. The therapeutic effects of long multi-epitope peptides in combination with lenalidomide and anti-PD1 were confirmed in the murine GL261 intracranial glioma model. Immune cells’ distribution and responses to the long multi-epitope peptides in combination with these adjuvants were also estimated in the spleens, lymph nodes, and tumor tissues. The difference between long multi-epitope peptides and a cocktail of multi-epitope peptides combined with lenalidomide and anti-PD1 was also clarified. As a result, long multi-epitope peptides combined with lenalidomide and anti-PD1 prolonged the survival of mice according to the suppression of tumor growth in an intracranial mouse model. While long multi-epitope peptides combined with these adjuvants enhanced the percentages of activated and memory effector CD8+ T cells, the increase in percentages of regulatory T cells (Tregs) was observed in a cocktail of multi-epitope peptides combined with lenalidomide and anti-PD1 group in the tumors. Long multi-epitope peptides combined with these adjuvants also enhanced the function of immune cells according to the enhanced pro-inflammatory cytokines and cytotoxicity against GL261 cells in ex vivo. In conclusion, long multi-epitope peptides composed of MHCI peptides, BIRC5 and EphA2, and the MHCII peptide, PADRE, in combination with lenalidomide and anti-PD1 has the potential to improve the therapeutic effects of a vaccine against GBM.

Understanding the Role of T-Cells in the Antimyeloma Effect of Immunomodulatory Drugs

Immunomodulatory drugs (IMiDs) are effective treatments for patients with multiple myeloma. IMiDs have pleotropic effects including targeting the myeloma cells directly, and improving the anti-myeloma immune response. In the absence of myeloma cells, lenalidomide and pomalidomide induce CD4⁺ T cell secretion of IL-2 and indirect activation of Natural Killer (NK) cells. In the context of T cell receptor ligation, IMiDs enhance T cell proliferation, cytokine release and Th1 responses, both in vivo and in vitro. Furthermore, combination treatment of IMiDs and myeloma-targeting monoclonal antibodies eg. daratumumab (anti-CD38) and elotuzumab (anti-SLAMF7), checkpoint inhibitors, or bispecific T cell engagers showed synergistic effects, mainly via enhanced T and NK cell dependent cellular toxicity and T cell proliferation. Conversely, the corticosteroid dexamethasone can impair the immune modulatory effects of IMiDs, indicating that careful choice of myeloma drugs in combination with IMiDs is key for the best anti-myeloma therapeutic efficacy. This review presents an overview of the role for T cells in the overall anti-myeloma effects of immunomodulatory drugs.