Fermentable fiber-induced hepatocellular carcinoma in mice recapitulates gene signatures found in human liver cancer

PAARH promotes M2 macrophage polarization and immune evasion of liver cancer cells through VEGF protein

OBJECTIVE

This study aims to investigate the mechanism by which PAARH promotes M2 macrophage polarization and immune evasion of liver cancer cells through VEGF, in order to reveal its role in the progression of liver cancer.

METHODS

The expressions of PAARH, VEGF, and HIF-1α in liver cancer cells were detected using qRT-PCR and Western blot. Flow cytometry was utilized to analyze the polarization status of macrophages and assess the impact on immune evasion-related markers. The relationship between PAARH and VEGF in macrophage polarization was further explored. Additionally, a tumor-bearing mouse model was established to observe tumor growth.

RESULTS

The results show that PAARH is upregulated in liver cancer cells, and silencing PAARH significantly inhibits tumor malignancy progression. Under hypoxic conditions, overexpression of PAARH significantly increases VEGF expression, and PAARH regulates M2 macrophage polarization through VEGF. Overexpression of PAARH significantly promotes M2 macrophage polarization, increases levels of PD-L1 and Th2 immune response markers, and enhances cell proliferation, migration, and invasion; it also suppresses M1 macrophage polarization, decreases levels of PD-L2 and Th1 immune response markers, and inhibits cell apoptosis. Silencing VEGF reverses these effects. Silencing PAARH or overexpressing VEGF weakens the malignant phenotype of the cells and immune evasion. Results from the tumor-bearing mouse model indicate that silencing PAARH significantly reduces tumor size and weight, while overexpressing VEGF significantly increases tumor volume and weight.

CONCLUSION

PAARH enhances the immune evasion capability of liver cancer cells by upregulating VEGF to promote M2 macrophage polarization, suggesting that PAARH may serve as a new therapeutic target for liver cancer.

Urine-based Detection of Congenital Portosystemic Shunt in C57BL/6 Mice

Sporadic occurrence of congenital portosystemic shunt (PSS) at a rate of ∼1 out of 10 among C57BL/6 J mice, which are widely used in biomedical research, results in aberrancies in serologic, metabolic, and physiologic parameters. Therefore, mice with PSS should be identified as outliers in research. Accordingly, we sought methods to, reliably and efficiently, identify PSS mice. Serum total bile acids ≥ 40 µm is a bona fide biomarker of PSS in mice but utility of this biomarker is limited by its cost and invasiveness, particularly if large numbers of mice are to be screened. This led us to investigate if assay of urine might serve as a simple, inexpensive, noninvasive means of PSS diagnosis. Metabolome profiling uncovered that Krebs cycle intermediates, that is, citrate, α-ketoglutarate, and fumarate, were strikingly and distinctly elevated in the urine of PSS mice. We leveraged the iron-chelating and pH-lowering properties of such metabolites as the basis for 3 urine-based PSS screening tests: urinary iron-chelation assay, pH strip test, and phenol red assay. Our findings demonstrate the feasibility of using these colorimetric assays, whereby their readout can be assessed by direct observation, to diagnose PSS in an inexpensive, rapid, and noninvasive manner. Application of our urinary PSS screening protocols can aid biomedical research by enabling stratification of PSS mice, which, at present, likely confound numerous ongoing studies.

The Characteristics and Function of Internalin G in Listeria monocytogenes

In order to clarified characteristics and function of internalin G (inlG) in Listeria monocytogenes ATCC®19111 (1/2a) (LM), the immune protection of the inlG was evaluated in mice, the homologous recombination was used to construct inlG deletion strains, and their biological characteristics were studied by the transcriptomics analysis. As a result, the immunization of mice with the purified protein achieved a protective effect against bacterial infection. The deletion strain LM-AinlG was successfully constructed with genetic stability. The mouse infection test showed that the virulence of LM was decreased after the deletion of the inlG gene. The deletion strain showed enhanced adhesion to and invasion of Caco-2 cells. Compared to the wild strain, 18 genes were up-regulated, and 24 genes were down-regulated in the LM-AinlG. This study has laid a foundation for further research on the function of inlG and the pathogenesis of LM. In this study, immunization of mice with the purified inlG protein achieved a protective effect against Listeria monocytogenes infection. The virulence of LM-ΔinlG was decreased by mouse infection. However, the adhesion and invasion ability to Caco-2 cell were enhanced. Compared to the wild strain, 18 genes were up-regulated, and 24 genes were down-regulated in the LM-ΔinlG. This study has laid a foundation for further study of the function of the inlG and the listeriosis.

An integrated analysis of the effects of maternal broccoli sprouts exposure on transcriptome and methylome in prevention of offspring mammary cancer

Broccoli sprouts (BSp), a cruciferous vegetable, has shown promising effects on prevention of many types of cancer including breast cancer (BC). BC has a developmental foundation, and maternal nutrition status may influence an offspring’s risk to BC later in life. What is less understood, however, is the influence of maternal nutrition intervention on reversing epigenomic abnormalities that are essential in BC programming during early development. Our research focused on how maternal exposure to BSp diet prevents offspring BC and investigation of possible epigenetic mechanisms during these processes. Our results showed that maternal feeding of BSp can prevent mammary tumor development in the offspring of a transgenic mouse model. Through comprehensive integrated multi-omics studies on transcriptomic and methylomic analysis, we identified numerous target genes exhibiting significantly differential gene expression and DNA methylation patterns in the offspring mammary tumor. We discovered that maternal exposure to BSp diet can induce both gene and methylation changes in several key genes such as Avpr2, Cyp4a12b, Dpp6, Gria2, Pcdh9 and Tspan11 that are correlated with pivotal biological functions during carcinogenesis. In addition, we found an impact of maternal BSp treatment on DNA methyltransferase and histone deacetylases activity. Our study provides knowledgeable information regarding how maternal BSp diet influences key tumor-related gene expression and the epigenetic changes using a genome-wide perspective. Additionally, these findings provide mechanistic insights into the effectiveness of maternal BSp administration on the prevention of BC in the offspring later in life, which may lead to an early-life BC chemopreventive strategy that benefits the progenies’ long-term health.