PI3Kα inhibitor GNE-493 triggers antitumor immunity in murine lung cancer by inducing immunogenic cell death and activating T cells

Phosphatidylinositol 3-kinase (PI3K) is frequently hyperactivated in cancer, playing pivotal roles in the pathophysiology of both malignant and immune cells. The impact of PI3K inhibitors on the tumor microenvironment (TME) within lung cancer remains largely unknown. In this study, we explored the regulatory effects of GNE-493, an innovative dual inhibitor of PI3K and mammalian target of rapamycin (mTOR), on the TME of lung cancer. First, through the analysis of The Cancer Genome Atlas-lung squamous cell carcinoma (LUSC) cohort, we found PIK3CA to be related to CD8 T cells, which may affect the overall survival rate of patients by affecting CD8 function. We herein demonstrated that GNE-493 can significantly inhibit tumor cell proliferation and promote cell apoptosis while increasing the expression of the immunogenic death-related molecules CRT and HSP70 using in vitro cell proliferation and apoptosis experiments on the murine KP lung cancer cell line and human A549 lung cancer cell line. Next, through the establishment of an orthotopic tumor model in vivo, it was found that after GNE-493 intervention, the infiltration of CD4+ and CD8+ T cells in mouse lung tumor was significantly increased, and the expression of CRT in tumors could be induced to increase. To explore the mechanisms underlying PI3K inhibition-induced changes in the TME, the gene expression differences of T cells in the control group versus GNE-493-treated KP tumors were analyzed by RNA-seq, and the main effector pathway of anti-tumor immunity was identified. The IFN/TNF family molecules were significantly upregulated after GNE-493 treatment. In summary, our findings indicate that GNE-493 promotes immunogenic cell death in lung cancer cells, and elucidates its regulatory impact on molecules associated with the adaptive immune response. Our study provides novel insights into how PI3K/mTOR inhibitors exert their activity by modulating the tumor-immune interaction.

Ketoglutaric acid can reprogram the immunophenotype of triple-negative breast cancer after radiotherapy and improve the therapeutic effect of anti-PD-L1

BACKGROUND

Great progress has been made in applying immunotherapy to the clinical treatment of tumors. However, many patients with triple-negative breast cancer (TNBC) cannot benefit from immunotherapy due to the immune desert type of TNBC, which is unresponsive to immunotherapy. DMKG, a cell-permeable derivative of α-KG, has shown potential to address this issue.

METHOD

We investigated the effects of combining DMKG with radioimmunotherapy on TNBC. We assessed the ability of DMKG to promote tumor cell apoptosis and immunogenic death induced by radiotherapy (RT), as well as its impact on autophagy reduction, antigen and inflammatory factor release, DC cell activation, and infiltration of immune cells in the tumor area.

RESULT

Our findings indicated that DMKG significantly promoted tumor cell apoptosis and immunogenic death induced by RT. DMKG also significantly reduced autophagy in tumor cells, resulting in increased release of antigens and inflammatory factors, thereby activating DC cells. Furthermore, DMKG promoted infiltration of CD8 + T cells in the tumor area and reduced the composition of T-regulatory cells after RT, reshaping the tumor immune microenvironment. Both DMKG and RT increased the expression of PD-L1 at immune checkpoints. When combined with anti-PD-L1 drugs (α-PD-L1), they significantly inhibited tumor growth without causing obvious side effects during treatment.

CONCLUSION

Our study underscores the potential of pairing DMKG with radioimmunotherapy as an effective strategy for treating TNBC by promoting apoptosis, immunogenic death, and remodeling the tumor immune microenvironment. This combination therapy could offer a promising therapeutic avenue for TNBC patients unresponsive to conventional immunotherapy.

Evidence of immunogenic cancer cell death induced by honey-processed Astragalus polysaccharides in vitro and in vivo

Honey-processed Astragalus is a dosage form of Radix Astragalus mixed with honey by a traditional Chinese medicine processing method which improves immune activity. This pharmacological activity of honey-processed Astragalus polysaccharide (HP-APS) might be due to structural changes during the honey roasting process. Previously, we have prepared and characterized HP-APS and preliminarily found its anti-inflammatory effects. However, whether the pharmacodynamic activity of HP-APS induces tumor cell apoptosis and the mechanisms responsible for the immunogenic death (ICD) have not been elucidated. Here, A549, MC38 and B16 cells were used to evaluate the cells viability, apoptosis and cell cycles, respectively. Cellular immunogenic cell death-related molecules calreticulin (CRT), Heat Shock Proteins (HSP)70, major histocompatibility complex I (MHC-I), and co-stimulator molecules CD80/CD86 were determined by flow cytometry. The extracellular ATP release was also detected. B16-OVA and MC38-OVA cells were treated with HP-APS and co-cultivated with OT1 mouse of CD3+T cells for assessment of proliferation, in mice model, and the establishment of C57BL/B6 mouse model bearing B16 cells for assessment of HP-APS the regulation of immune activity in vivo. Our results showed that HP-APS has an inhibitory effect on tumor cell proliferation, which induces tumor cell apoptosis, preventing cells-transforming from G1 phase to S phase in cell cycles. Furthermore, HP-APS could effectively increase the expression of HSP70, CRT, MHC-I, CD86, CD80 and ATP release. T cell proliferation index is significantly improved. CD3 cell proliferation in OT1 mice was significantly increased from the 4th generation to the 5th generation. Moreover, the results have also shown that HP-APS could inhibit tumor growth by increasing immune cell infiltration in the tumor tissues. In the mouse melanoma model with HP-APS treatment, the tumor weight and volume were significantly reduced, and the growth of melanoma was inhibited. CD8⁺ T is significantly increased. The ratio of CD4⁺ T and CD8⁺ T cells numbers are also significantly increased in mouse spleen, but it is less than PD-1 alone treatment separately. Altogether, these findings suggest that HP-APS exerts anti-tumor effects, and that its underlying mechanisms might be associated with the expression of immunogenicity cell death related molecules and the immunomodulatory effects of immune cells.

[The anti-tumor immune response in breast cancer: Update and therapeutic perspectives]

The role of the immune response in breast cancer is now well recognized and increasingly taken in account. The goal of this article is, in the first part, to underline its prognostic impact and to precise the immunosurvelliance, immunoselection and the immunosubversion concepts involved in the control and evasion of breast carcinoma. In the second part, therapeutic strategies for the restauration of anti-tumor immunity are developed. Vaccination strategies and checkpoints inhibitors blockade strategies are discussed as well as the immunogenic death linked to the conventional treatments of breast cancer.