Evaluation of Parent- and Metabolite-Induced Mitochondrial Toxicities Using CYP-Introduced HepG2 cells

GP73-mediated secretion of PKM2 and GP73 promotes angiogenesis and M2-like macrophage polarization in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Abnormally high expression of Golgi protein 73 (GP73) and pyruvate kinase M2 (PKM2) is intimately associated with HCC progression. However, as secreted proteins, the role of their extracellular secretions in HCC progression remains unclear. Here, we demonstrated that the expression of extracellular GP73 was positively correlated with extracellular PKM2. GP73 interacted with PKM2 to promote SUMO1 modification of PKM2, which in turn enhanced the interaction of GP73 and PKM2. This process continuously promoted the transfer of PKM2 from the cytoplasm to the membrane in HCC cells, and finally secretion. Extracellular PKM2 and GP73 synergistically promoted angiogenesis and polarization of M2-type macrophages, thereby leading to malignant progression and sorafenib resistance in HCC. Sorafenib combined with shikonin, a specific inhibitor of PKM2, has a strong anti-tumor effect. This study reveals the role of GP73 in enhancing PKM2 and GP73 secretion in promoting HCC progression, providing a theoretical basis and drug targets for HCC therapy.

A novel diphenylbutenoid-type compound from the rhizomes of Zingiber montanum (J.Koenig) Link ex A.Dietr. (Zingiberaceae)

From the EtOAc-soluble extract of the rhizomes of Zingiber montanum (J.Koenig) Link ex A.Dietr., a novel diphenylbutenoid, montadinin A (1) and a previously unreported phenylbutenoid compound, 1-(3,4-dimethoxyphenyl)but-3-en-2-ol (7), in natural source were isolated. Additionally, seven known phenylbutenoids were also identified. The structures of all compounds were elucidated through NMR spectroscopic interpretation. Compounds cis-3-(3,4-dimethoxyphenyl)-4-[(E)-3,4-dimethoxystyryl]cyclohex-1-ene (2), cis-4-[(E)-3,4-dimethoxystyryl]-3-(2,4,5-trimethoxyphenyl)cyclohex-1-ene (3), trans-3-(3,4,-dimethoxyphenyl)-4-[(E)-2,4,5-trimethoxystyryl]cyclohex-1-ene (5), and cis-3-(3,4-dimethoxyphenyl)-4-[(Z)-2,4,5-trimethoxylstyryl]cyclohex-1-ene (6) showed weak cytotoxicity against HepG2 cells with IC50 values of 122.9, 127.3, 257.5, and 168.5 µM, respectively.

New in vitro screening system to detect drug-induced liver injury using a culture plate with low drug sorption and high oxygen permeability

Drug-induced liver injury (DILI) is a major factor underlying drug withdrawal from the market. Therefore, it is important to predict DILI during the early phase of drug discovery. Metabolic activation and mitochondrial toxicity are good indicators of the potential for DILI. However, hepatocyte function, including drug-metabolizing enzyme activity and mitochondrial function, reportedly decreases under conventional culture conditions; therefore, these conditions fail to precisely detect metabolic activation and mitochondrial toxicity-induced cell death. To resolve this issue, we employed a newly developed cell culture plate with high oxygen permeability and low drug sorption (4-polymethyl-1-pentene [PMP] plate). Under PMP plate conditions, cytochrome P450 (CYP) activity and mitochondrial function were increased in primary rat hepatocytes. Following l-buthionine-sulfoximine-induced glutathione depletion, acetaminophen-induced cell death significantly increased under PMP plate conditions. Additionally, 1-aminobenzotriazole reduced cell death. Moreover, mitochondrial toxicity due to mitochondrial complex inhibitors (ketoconazole, metformin, and phenformin) increased under PMP plate conditions. In summary, PMP plate conditions could improve CYP activity and mitochondrial function in primary rat hepatocytes and potentially detect metabolic activation and mitochondrial toxicity.

Hydroxylation markedly alters how the polychlorinated biphenyl (PCB) congener, PCB52, affects gene expression in human preadipocytes

Polychlorinated biphenyls (PCBs) accumulate in adipose tissue and are linked to obesity and diabetes. The congener, PCB52 (2,2',5,5'-tetrachorobiphenyl), is found at high levels in school air. Hydroxylation of PCB52 to 4-OH-PCB52 (4-hydroxy-2,2',5,5'-tetrachorobiphenyl) may increase its toxicity. To understand PCB52's role in causing adipose dysfunction, we exposed human preadipocytes to PCB52 or 4-OH-PCB52 across a time course and assessed transcript changes using RNAseq. 4-OH-PCB52 caused considerably more changes in the number of differentially expressed genes as compared to PCB52. Both PCB52 and 4-OH-PCB52 upregulated transcript levels of the sulfotransferase SULT1E1 at early time points, but cytochrome P450 genes were generally not affected. A set of genes known to be transcriptionally regulated by PPARα were consistently downregulated by PCB52 at all time points. In contrast, 4-OH-PCB52 affected a variety of pathways, including those involving cytokine responses, hormone responses, focal adhesion, Hippo, and Wnt signaling. Sets of genes known to be transcriptionally regulated by IL17A or parathyroid hormone (PTH) were found to be consistently downregulated by 4-OH-PCB52. Most of the genes affected by PCB52 and 4-OH-PCB52 were different and, of those that were the same, many were changed in an opposite direction. These studies provide insight into how PCB52 or its metabolites may cause adipose dysfunction to cause disease.

The Curious Case of the HepG2 Cell Line: 40 Years of Expertise

Liver cancer is the third leading cause of cancer death worldwide. Representing such a dramatic impact on our lives, liver cancer is a significant public health concern. Sustainable and reliable methods for preventing and treating liver cancer require fundamental research on its molecular mechanisms. Cell lines are treated as in vitro equivalents of tumor tissues, making them a must-have for basic research on the nature of cancer. According to recent discoveries, certified cell lines retain most genetic properties of the original tumor and mimic its microenvironment. On the other hand, modern technologies allowing the deepest level of detail in omics landscapes have shown significant differences even between samples of the same cell line due to cross- and mycoplasma infection. This and other observations suggest that, in some cases, cell cultures are not suitable as cancer models, with limited predictive value for the effectiveness of new treatments. HepG2 is a popular hepatic cell line. It is used in a wide range of studies, from the oncogenesis to the cytotoxicity of substances on the liver. In this regard, we set out to collect up-to-date information on the HepG2 cell line to assess whether the level of heterogeneity of the cell line allows in vitro biomedical studies as a model with guaranteed production and quality.

The Curious Case of the HepG2 Cell Line: 40 Years of Expertise

Liver cancer is the third leading cause of cancer death worldwide. Representing such a dramatic impact on our lives, liver cancer is a significant public health concern. Sustainable and reliable methods for preventing and treating liver cancer require fundamental research on its molecular mechanisms. Cell lines are treated as in vitro equivalents of tumor tissues, making them a must-have for basic research on the nature of cancer. According to recent discoveries, certified cell lines retain most genetic properties of the original tumor and mimic its microenvironment. On the other hand, modern technologies allowing the deepest level of detail in omics landscapes have shown significant differences even between samples of the same cell line due to cross- and mycoplasma infection. This and other observations suggest that, in some cases, cell cultures are not suitable as cancer models, with limited predictive value for the effectiveness of new treatments. HepG2 is a popular hepatic cell line. It is used in a wide range of studies, from the oncogenesis to the cytotoxicity of substances on the liver. In this regard, we set out to collect up-to-date information on the HepG2 cell line to assess whether the level of heterogeneity of the cell line allows in vitro biomedical studies as a model with guaranteed production and quality.

The Curious Case of the HepG2 Cell Line: 40 Years of Expertise

Liver cancer is the third leading cause of cancer death worldwide. Representing such a dramatic impact on our lives, liver cancer is a significant public health concern. Sustainable and reliable methods for preventing and treating liver cancer require fundamental research on its molecular mechanisms. Cell lines are treated as in vitro equivalents of tumor tissues, making them a must-have for basic research on the nature of cancer. According to recent discoveries, certified cell lines retain most genetic properties of the original tumor and mimic its microenvironment. On the other hand, modern technologies allowing the deepest level of detail in omics landscapes have shown significant differences even between samples of the same cell line due to cross- and mycoplasma infection. This and other observations suggest that, in some cases, cell cultures are not suitable as cancer models, with limited predictive value for the effectiveness of new treatments. HepG2 is a popular hepatic cell line. It is used in a wide range of studies, from the oncogenesis to the cytotoxicity of substances on the liver. In this regard, we set out to collect up-to-date information on the HepG2 cell line to assess whether the level of heterogeneity of the cell line allows in vitro biomedical studies as a model with guaranteed production and quality.