Downregulation of B7-H4 suppresses tumor progression of hepatocellular carcinoma

B7H4 Role in Solid Cancers: A Review of the Literature

Anti-cancer immunotherapies entirely changed the therapeutic approach to oncological patients. However, despite the undeniable success of anti-PD-1, PD-L1, and CTLA-4 antibody treatments, their effectiveness is limited either by certain types of malignancies or by the arising problem of cancer resistance. B7H4 (aliases B7x, B7H4, B7S1, VTCN1) is a member of a B7 immune checkpoint family with a distinct expression pattern from classical immune checkpoint pathways. The growing amount of research results seem to support the thesis that B7H4 might be a very potent therapeutic target. B7H4 was demonstrated to promote tumour progression in immune "cold" tumours by promoting migration, proliferation of tumour cells, and cancer stem cell persistence. B7H4 suppresses T cell effector functions, including inflammatory cytokine production, cytolytic activity, proliferation of T cells, and promoting the polarisation of naïve CD4 T cells into induced Tregs. This review aimed to summarise the available information about B7H4, focusing in particular on clinical implications, immunological mechanisms, potential strategies for malignancy treatment, and ongoing clinical trials.

Cooperative Treatment of Gastric Cancer Using B7-H7 siRNA and Docetaxel; How Could They Modify Their Effectiveness?

Purpose

Despite the high prevalence of gastric cancer (GC), drug resistance is a major problem for effective chemotherapy. B7-H7 is a novel member of the B7 superfamily and is expressed in most common cancers. However, the role of B7-H7 on the aggressiveness of GC and chemosensitivity has remained unknown. Therefore, this study was designed to assess the effect of B7-H7 suppression using small interference RNA (siRNA) in combination with docetaxel on GC cells.

Methods

MTT test was applied to determine the IC50 of docetaxel and the combined effect of B7-H7 siRNA and docetaxel on the viability of the MKN-45 cells. To determine B7-H7, BCL-2, BAX, and caspase-3-8-9 genes expression, qRT-PCR was performed. Furthermore, flow cytometry was applied to evaluate apoptosis and the cell cycle status. Finally, to evaluate the effect of this combination therapy on migratory capacity and colony-forming ability, wound healing assay and colony formation test were employed, respectively.

Results

B7-H7 suppression increased the chemo-sensitivity of MKN-45 cells to docetaxel. The expression of B7-H7 mRNA was reduced after using B7-H7 siRNA and docetaxel in MKN-45 GC cells. Also, B7-H7 suppression alongside docetaxel reduced cell migration and colony formation rate, arrested the cell cycle at the G2-M phase, and induced apoptosis by modulating the expression of apoptotic target genes.

Conclusion

B7-H7 plays a significant role in the chemo-sensitivity and pathogenesis of GC. Therefore, B7-H7 suppression, in combination with docetaxel, may be a promising therapeutic approach in treating GC.

Integrated Bioinformatic Analysis of DNA Methylation and Immune Infiltration in Endometrial Cancer

Background

Endometrial cancer greatly threatens the health of female. Emerging evidences have demonstrated that DNA methylation and immune infiltration are involved in the occurrence and development of endometrial cancer. However, the mechanism and prognostic biomarkers of endometrial cancer are still unclear. In this study, we assess DNA methylation and immune infiltration via bioinformatic analysis.

Methods

The latest RNA-Seq, DNA methylation data, and clinical data related to endometrial cancer were downloaded from the UCSC Xena dataset. The methylation-driven genes were selected, and then the risk score was obtained using “MethylMix” and “corrplot” R packages. The connection between methylated genes and the expression of screened driven genes were explored using “survminer” and “beeswarm” packages, respectively. Finally, the role of VTCN1in immune infiltration was analyzed using “CIBERSORT” package.

Results

In this study, 179 upregulated genes, and 311 downregulated genes were identified and found to be related to extracellular matrix organization, cell–cell junctions, and cell adhesion molecular binding. The methylation-driven gene VTCN1 was selected, and patients classified to the hypomethylation and high expression group displayed poor prognosis. The VTCN1 gene exhibited highest correlation coefficient between methylation and expression. More importantly, the hypomethylation of promoter of VTCN1 led to its high expression, thereby induce tumor development by inhibiting CD8+ T cell infiltration.

Conclusions

Overall, our study was the first to reveal the mechanism of endometrial cancer by assessing DNA methylation and immune infiltration via integrated bioinformatic analysis. In addition, we found a pivotal prognostic biomarker for the disease. Our study provides potential targets for the diagnosis and prognosis of endometrial cancer in the future.

HIF inhibitor 32-134D eradicates murine hepatocellular carcinoma in combination with anti-PD1 therapy

Hepatocellular carcinoma (HCC) is a major cause of cancer mortality worldwide and available therapies, including immunotherapies, are ineffective for many patients. HCC is characterized by intratumoral hypoxia, and increased expression of hypoxia-inducible factor 1α (HIF-1α) in diagnostic biopsies is associated with patient mortality. Here we report the development of 32-134D, a low-molecular-weight compound that effectively inhibits gene expression mediated by HIF-1 and HIF-2 in HCC cells, and blocks human and mouse HCC tumor growth. In immunocompetent mice bearing Hepa1-6 HCC tumors, addition of 32-134D to anti-PD1 therapy increased the rate of tumor eradication from 25% to 67%. Treated mice showed no changes in appearance, behavior, body weight, hemoglobin, or hematocrit. Compound 32-134D altered the expression of a large battery of genes encoding proteins that mediate angiogenesis, glycolytic metabolism, and responses to innate and adaptive immunity. This altered gene expression led to significant changes in the tumor immune microenvironment, including a decreased percentage of tumor-associated macrophages and myeloid-derived suppressor cells, which mediate immune evasion, and an increased percentage of CD8⁺ T cells and natural killer cells, which mediate antitumor immunity. Taken together, these preclinical findings suggest that combining 32-134D with immune checkpoint blockade may represent a breakthrough therapy for HCC.

Pan-Tissue Aging Clock Genes That Have Intimate Connections with the Immune System and Age-Related Disease

In our recent transcriptomic meta-analysis, we used random forest machine learning to accurately predict age in human blood, bone, brain, heart, and retina tissues given gene inputs. Although each tissue-specific model utilized a unique number of genes for age prediction, we found that the following six genes were prioritized in all five tissues: CHI3L2, CIDEC, FCGR3A, RPS4Y1, SLC11A1, and VTCN1. Since being selected for age prediction in multiple tissues is unique, we decided to explore these pan-tissue clock genes in greater detail. In the present study, we began by performing over-representation and network topology-based enrichment analyses in the Gene Ontology Biological Process database. These analyses revealed that the immunological terms "response to protozoan," "immune response," and "positive regulation of immune system process" were significantly enriched by these clock inputs. Expression analyses in mouse and human tissues identified that these inputs are frequently upregulated or downregulated with age. A detailed literature search showed that all six genes had noteworthy connections to age-related disease. For example, mice deficient in Cidec are protected against various metabolic defects, while suppressing VTCN1 inhibits age-related cancers in mouse models. Using a large multitissue transcriptomic dataset, we additionally generate a novel, minimalistic aging clock that can predict human age using just these six genes as inputs. Taken all together, these six genes are connected to diverse aspects of aging.

High membrane expression of CMTM6 in hepatocellular carcinoma is associated with tumor recurrence

CKLF-like MARVEL transmembrane domain-containing protein 6 (CMTM6) maintains membrane PD-L1 expression by controlling its endosomal recycling. However, in patients with hepatocellular carcinoma (HCC), the correlation among CMTM6, B7 family ligands, and CD8-positive cytotoxic T lymphocytes (CTLs), and the molecular function of CMTM6 in HCC have not been established. We performed immunohistochemistry to evaluate the relationships among CMTM6 expression, clinicopathological factors, B7 family ligands expression, and CTL infiltration in HCC samples. Moreover, we established CMTM6-knockout human HCC cell lines to evaluate the function of human CMTM6 in immune regulation and tumor viability. CMTM6 expression was positively associated with membrane B7 family ligands expression and CTL infiltration in HCC samples. High CMTM6 expression in HCC tissues was associated with the expression of the proliferation marker Ki-67 and shorter recurrence-free survival. In vitro analysis showed the downregulation of membrane B7 family ligands and proliferation potency in the CMTM6-knockout human HCC cell line. High membrane CMTM6 expression was associated with tumor recurrence and proliferation via the regulation of membranous B7 family ligands expression. Thus, CMTM6 might be a biomarker to predict the risk of HCC recurrence and a therapeutic target to suppress tumor growth and increase CTL activity.

Immune Checkpoints, Inhibitors and Radionuclides in Prostate Cancer: Promising Combinatorial Therapy Approach

Emerging research demonstrates that co-inhibitory immune checkpoints (ICs) remain the most promising immunotherapy targets in various malignancies. Nonetheless, ICIs have offered insignificant clinical benefits in the treatment of advanced prostate cancer (PCa) especially when they are used as monotherapies. Current existing PCa treatment initially offers an improved clinical outcome and overall survival (OS), however, after a while the treatment becomes resistant leading to aggressive and uncontrolled disease associated with increased mortality and morbidity. Concurrent combination of the ICIs with radionuclides therapy that has rapidly emerged as safe and effective targeted approach for treating PCa patients may shift the paradigm of PCa treatment. Here, we provide an overview of the contextual contribution of old and new emerging inhibitory ICs in PCa, preclinical and clinical studies supporting the use of these ICs in treating PCa patients. Furthermore, we will also describe the potential of using a combinatory approach of ICIs and radionuclides therapy in treating PCa patients to enhance efficacy, durable cancer control and OS. The inhibitory ICs considered in this review are cytotoxic T-lymphocyte antigen 4 (CTLA4), programmed cell death 1 (PD1), V-domain immunoglobulin suppressor of T cell activation (VISTA), indoleamine 2,3-dioxygenase (IDO), T cell Immunoglobulin Domain and Mucin Domain 3 (TIM-3), lymphocyte-activation gene 3 (LAG-3), T cell immunoreceptor with Ig and ITIM domains (TIGIT), B7 homolog 3 (B7-H3) and B7-H4.

Inhibition of B7-H4 promotes hepatocellular carcinoma cell apoptosis and autophagy through the PI3K signaling pathway

B7-H4 and autophagy can regulate or be induced by the PI3K signaling pathway. However, the association between B7-H4 and autophagy in hepatocellular carcinoma (HCC)remains unclear. The aim of this work was to investigate whether B7-H4 regulates autophagy via the PI3K signaling pathway in HCC cells. Here, western blotting was used to measure the expression of the related proteins involved in changes in of autophagy and apoptosis, such as LC3, P62, cleaved caspase 3, cleaved PARP, BCL-2, and BAX in Huh7 and Hep3B cells. Additionally, PI3K/AKT/mTOR signaling pathway proteins were measured. Cell counting kit-8 and flow cytometry were used to analyze the effects of B7-H4 siRNA interference on cell proliferation with the interference of B7-H4 siRNA. We found that B7-H4 siRNA increased HCC cell apoptosis and autophagy, and reduced cell proliferation. Moreover, the apoptosis-related proteins cleaved caspase 3, cleaved PARP and BAX were increased and Bcl-2 was decreased after B7-H4 siRNA interference. The expression level of the autophagy-related protein LC3Ⅱ was upregulated, while expression of the autophagy adaptor P62 expression was decreased in B7-H4 siRNA-pretreated cells. Furthermore, our data revealed that B7-H4 regulated apoptosis and autophagy through the PI3K signaling pathway in HCC cells. Therefore, these results suggested that B7-H4 plays an important role in HCC progression by affecting cell apoptosis and autophagy.