Enhancing antitumor efficacy of oncolytic virus M1 via albendazole-sustained CD8+ T cell activation.

The immune response plays a crucial role in the functionality of oncolytic viruses. In this study, Albendazole, an antihelminthic drug known to modulate the immune checkpoint PD-L1, was combined with the oncolytic virus M1 (OVM1) to treat mice with either prostate cancer (RM-1) or glioma (GL261) tumors. This combination therapy enhanced anti-tumor effects in immunocompetent mice, but not in immunodeficient ones, without increasing OVM1 replication. Instead, it led to an increase in the number of CD8+ T cells within the tumor, downregulated the expression of PD1 on CD8+ T cells, and upregulated activation markers such as Ki67, CD44, and CD69 and the secretion of cytotoxic factors including interferon (IFN)-γ, granzyme B, and tumor necrosis factor (TNF)-α. Consistently, it enhanced the in vitro tumor-killing activity of lymphocytes from tumor-draining lymph nodes or spleens. The synergistic effect of Albendazole on OVM1 was abolished by depleting CD8+ T cells, suggesting a CD8+ T cell-dependent mechanism. In addition, Albendazole and OVM1 therapy increased CTLA4 expression in the spleen, and the addition of CTLA4 antibodies further enhanced the anti-tumor efficacy in vivo. In summary, Albendazole can act synergistically with oncolytic viruses via CD8+ T cell activation, and the Albendazole/OVM1 combination can overcome resistance to CTLA4-based immune checkpoint blockade therapy.

TUBB2B facilitates progression of hepatocellular carcinoma by regulating cholesterol metabolism through targeting HNF4A/CYP27A1.

Cholesterol metabolism plays a critical role in the progression of hepatocellular carcinoma (HCC), but it is not clear how cholesterol metabolism is regulated. The tubulin beta class I genes (TUBBs) are associated with the prognosis of many different cancers. To confirm the function of TUBBs in HCC, the Kaplan-Meier method and Cox analyses were performed using TCGA and GSE14520 datasets. A higher expression of TUBB2B is an independent prognostic factor for shorter over survival in HCC patients. Deletion of TUBB2B in hepatocytes inhibits proliferation and promotes tumor cell apoptosis, while over-expression of TUBB2B has the opposite function. This result was confirmed in a mouse xenograft tumor model. Mechanistically, TUBB2B induces the expression of CYP27A1, an enzyme responsible for the conversion of cholesterol to 27-hydroxycholesterol, which leads to the up-regulation of cholesterol and the progression of HCC. In addition, TUBB2B regulates CYP27A1 via human hepatocyte nuclear factor 4alpha (HNF4A). These findings indicated that TUBB2B functions as an oncogene in HCC, and plays a role in promoting cell proliferation and anti-apoptosis through targeting HNF4A/CYP27A1/cholesterol.

Differential regulation of H3K9/H3K14 acetylation by small molecules drives neuron-fate-induction of glioma cell.

Differentiation therapy using small molecules is a promising strategy for improving the prognosis of glioblastoma (GBM). Histone acetylation plays an important role in cell fate determination. Nevertheless, whether histone acetylation in specific sites determines GBM cells fate remains to be explored. Through screening from a 349 small molecule-library, we identified that histone deacetylase inhibitor (HDACi) MS-275 synergized with 8-CPT-cAMP was able to transdifferentiate U87MG GBM cells into neuron-like cells, which were characterized by cell cycle arrest, rich neuron biomarkers, and typical neuron electrophysiology. Intriguingly, acetylation tags of histone 3 at lysine 9 (H3K9ac) were decreased in the promoter of multiple oncogenes and cell cycle genes, while ones of H3K9ac and histone 3 at lysine 14 (H3K14ac) were increased in the promoter of neuron-specific genes. We then compiled a list of genes controlled by H3K9ac and H3K14ac, and proved that it is a good predictive power for pathologic grading and survival prediction. Moreover, cAMP agonist combined with HDACi also induced glioma stem cells (GSCs) to differentiate into neuron-like cells through the regulation of H3K9ac/K14ac, indicating that combined induction has the potential for recurrence-preventive application. Furthermore, the combination of cAMP activator plus HDACi significantly repressed the tumor growth in a subcutaneous GSC-derived tumor model, and temozolomide cooperated with the differentiation-inducing combination to prolong the survival in an orthotopic GSC-derived tumor model. These findings highlight epigenetic reprogramming through H3K9ac and H3K14ac as a novel approach for driving neuron-fate-induction of GBM cells.

Disruption of ß-catenin-mediated negative feedback reinforces cAMP-induced neuronal differentiation in glioma stem cells.

Accumulating evidence supports the existence of glioma stem cells (GSCs) and their critical role in the resistance to conventional treatments for glioblastoma multiforme (GBM). Differentiation therapy represents a promising alternative strategy against GBM by forcing GSCs to exit the cell cycle and reach terminal differentiation. In this study, we demonstrated that cAMP triggered neuronal differentiation and compromised the self-renewal capacity in GSCs. In addition, cAMP induced negative feedback to antagonize the differentiation process by activating ß-catenin pathway. Suppression of ß-catenin signaling synergized with cAMP activators to eliminate GSCs in vitro and extended the survival of animals in vivo. The cAMP/PKA pathway stabilized ß-catenin through direct phosphorylation of the molecule and inhibition of GSK-3ß. The activated ß-catenin translocated into the nucleus and promoted the transcription of APELA and CARD16, which were found to be responsible for the repression of cAMP-induced differentiation in GSCs. Overall, our findings identified a negative feedback mechanism for cAMP-induced differentiation in GSCs and provided potential targets for the reinforcement of differentiation therapy for GBM.

Identification of the receptor of oncolytic virus M1 as a therapeutic predictor for multiple solid tumors.

Over the last decade, oncolytic virus (OV) therapy has shown its promising potential in tumor treatment. The fact that not every patient can benefit from it highlights the importance for defining biomarkers that help predict patients' responses. As particular self-amplifying biotherapeutics, the anti-tumor effects of OVs are highly dependent on the host factors for viral infection and replication. By using weighted gene co-expression network analysis (WGCNA), we found matrix remodeling associated 8 (MXRA8) is positively correlated with the oncolysis induced by oncolytic virus M1 (OVM). Consistently, MXRA8 promotes the oncolytic efficacy of OVM in vitro and in vivo. Moreover, the interaction of MXRA8 and OVM studied by single-particle cryo-electron microscopy (cryo-EM) showed that MXRA8 directly binds to this virus. Therefore, MXRA8 acts as the entry receptor of OVM. Pan-cancer analysis showed that MXRA8 is abundant in most solid tumors and is highly expressed in tumor tissues compared with adjacent normal ones. Further study in cancer cell lines and patient-derived tumor tissues revealed that the tumor selectivity of OVM is predominantly determined by a combinational effect of the cell membrane receptor MXRA8 and the intracellular factor, zinc-finger antiviral protein (ZAP). Taken together, our study may provide a novel dual-biomarker for precision medicine in OVM therapy.

Cytotoxic T lymphocyte-associated protein 4 antibody aggrandizes antitumor immune response of oncolytic virus M1 via targeting regulatory T cells.

Oncolytic virotherapies are perceived as remarkable immunotherapies coming into view and represent highly promising cancer treatments, yet to figure out its specific immune responses and underlying barriers remains critical. Albeit recent studies have demonstrated that oncolytic viruses (OVs) could fine tune tumor microenvironment (TME) to elicit tumor suppression mainly due to effective T-cell responses, the interaction between suppressive T cells and OVs is barely undetermined. Herein, we found that regulatory T cells (Treg cells) were increased in the TME following systemic administration of oncolytic virus M1 along with the higher expression of relative cytokines and chemokines in both mouse RM-1 prostatic carcinoma model and mouse B16F10 melanoma model. Besides, Treg cells expressed high levels of CD25 post-M1 treatment, and its suppressive effect on CD8+ T cells was also elevated. Depletion of Treg cells in M1-treated groups significantly reinforced antitumor effect of M1. Specific targeting of Treg cells using cytotoxic T lymphocyte-associated protein 4 (CTLA-4) antibody (Ab) in combination with M1 treatment elicited a more profound tumor suppression and longer overall survival time than M1 alone in both tumor models. Moreover, CTLA-4 Ab further aggrandized antitumor immune response elicited by M1, including increased infiltration of CD45+ immune cells and CD8+ or CD4+ T lymphocytes, decreased ratio of Treg cells to CD4+ T lymphocytes, the intensified lymphocytotoxicity and elevated secretion of cytotoxic cytokines like interferon-γ, granzyme B and perforin. Therefore, our findings constituted a suggestive evidence that targeting Treg cells in M1-based oncolytic virotherapy may achieve a highly response in clinical cancer research.

Effects of Differentiation and Antisenescence from BMSCs to Hepatocy-Like Cells of the PAAm-IGF-1/TNF-α Biomaterial.

Aiming at the cells' differentiation phenomenon and senescence problem in liver tissue engineering, this work is designed to synthesize three different chargeable polymers (polypropylene acid (PAAc), polyethylene glycol (PEG), and polypropylene amine (PAAm)) coimmobilized by the insulin-like growth factor 1 (IGF-1) and tumor necrosis factor-α (TNF-α). We explore the hepatocyte differentiation effect and the antisenecence effect of PSt-PAAm-IGF-1/TNF-α biomaterial which was selected from the three different chargeable polymers in bone marrow mesenchymal stem cells (BMSCs). Our work will establish a model for studying the biochemical molecular regulation mechanism and signal transduction pathway of cell senescence in liver tissue engineering, which provide a molecular basis for developing biomaterials for liver tissue engineering.