Emerging role of EPHX1 in chemoresistance of acute myeloid leukemia by regurlating drug‐metabolizing enzymes and apoptotic signaling

Identifying genes associated with resistance to KRAS G12C inhibitors via machine learning methods

BACKGROUND

Targeted therapy has revolutionized cancer treatment, greatly improving patient outcomes and quality of life. Lung cancer, specifically non-small cell lung cancer, is frequently driven by the G12C mutation at the KRAS locus. The development of KRAS inhibitors has been a breakthrough in the field of cancer research, given the crucial role of KRAS mutations in driving tumor growth and progression. However, over half of patients with cancer bypass inhibition show limited response to treatment. The mechanisms underlying tumor cell resistance to this treatment remain poorly understood.

METHODS

To address above gap in knowledge, we conducted a study aimed to elucidate the differences between tumor cells that respond positively to KRAS (G12C) inhibitor therapy and those that do not. Specifically, we analyzed single-cell gene expression profiles from KRAS G12C-mutant tumor cell models (H358, H2122, and SW1573) treated with KRAS G12C (ARS-1620) inhibitor, which contained 4297 cells that continued to proliferate under treatment and 3315 cells that became quiescent. Each cell was represented by the expression levels on 8687 genes. We then designed an innovative machine learning based framework, incorporating seven feature ranking algorithms and four classification algorithms to identify essential genes and establish quantitative rules.

RESULTS

Our analysis identified some top-ranked genes, including H2AFZ, CKS1B, TUBA1B, RRM2, and BIRC5, that are known to be associated with the progression of multiple cancers.

CONCLUSION

Above genes were relevant to tumor cell resistance to targeted therapy. This study provides important insights into the molecular mechanisms underlying tumor cell resistance to KRAS inhibitor treatment.

6-(7-Nitro-2,1,3-benzoxadiazol-4-ylthio) Hexanol Inhibits Proliferation and Induces Apoptosis of Endometriosis by Regulating Glutathione S-Transferase Mu Class 4

Endometriosis is a chronic disease associated with a disrupted oxidative balance and chronic inflammation. In this study, we investigated the role of glutathione S-transferase Mu class 4 (GSTM4) in endometriosis and determined whether 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio) hexanol (NBDHEX) regulates GSTM4 expression to affect cellular functions and oxidative stress. GSTM4 expression was detected by immunohistochemistry in endometrium from 15 endometriosis patients and 15 healthy controls. Western blotting was used to detect the expression of GSTM4, proliferating cell nuclear antigen (PCNA), matrix metalloproteinase-9 (MMP-9), Survivin, B-cell lymphoma-extra-large (Bcl-XL), Bax, kelch-like ECH-associated protein 1 (Keap1), and nuclear factor-erythroid 2-related factor 2 (Nrf2) in primary endometrial stromal cells with endometriosis (EESC) and normal endometrial stromal cells (NESC). The effects of NBDHEX on cell proliferation, migration, and invasion were evaluated using Cell Counting Kit-8 (CCK8) and Transwell assays. Apoptosis was detected by flow cytometry. The expression of GSTM4 was significantly increased in endometrium from endometriosis patients. Upon NBDHEX treatment, ESC exhibited reduced proliferation, migration and invasion abilities, and increased apoptosis. NBDHEX decreased the expression of endometriosis prognostic markers (PCNA and MMP-9) and anti-apoptotic proteins (Survivin and Bcl-xl), while it increased the expression of the apoptotic protein Bax. It had no effect on Keap1 expression, and it decreased the expression of Nrf2. The effect of siRNA-mediated knockdown of GSTM4 was similar to that of suppressing GSTM4 expression with NBDHEX treatment. These results indicate that GSTM4 is highly expressed in endometriosis and its expression is inhibited by NBDHEX. Decreased expression of GSTM4 inhibits cell growth, migration, and invasion, and negatively regulates Nrf2 to affect oxidative stress-induced apoptosis. Our results suggest that GSTM4 may play a role in ameliorating the progression of endometriosis. NBDHEX may have therapeutic potential in the treatment of endometriosis.

Evaluation and Application of Drug Resistance by Biomarkers in the Clinical Treatment of Liver Cancer

Liver cancer is one of the most lethal cancers in the world, mainly owing to the lack of effective means for early monitoring and treatment. Accordingly, there is considerable research interest in various clinically applicable methods for addressing these unmet needs. At present, the most commonly used biomarker for the early diagnosis of liver cancer is alpha-fetoprotein (AFP), but AFP is sensitive to interference from other factors and cannot really be used as the basis for determining liver cancer. Treatment options in addition to liver surgery (resection, transplantation) include radiation therapy, chemotherapy, and targeted therapy. However, even more expensive targeted drug therapies have a limited impact on the clinical outcome of liver cancer. One of the big reasons is the rapid emergence of drug resistance. Therefore, in addition to finding effective biomarkers for early diagnosis, an important focus of current discussions is on how to effectively adjust and select drug strategies and guidelines for the treatment of liver cancer patients. In this review, we bring this thought process to the drug resistance problem faced by different treatment strategies, approaching it from the perspective of gene expression and molecular biology and the possibility of finding effective solutions.

Effects of nanoplastic exposure on the immunity and metabolism of red crayfish (Cherax quadricarinatus) based on high-throughput sequencing

Previous studies have shown that nanoplastics (NPs) are harmful pollutants that threaten aquatic organisms and ecosystems, however, less research has been conducted on the hazards of NPs for aquaculture animals. In this study, Cherax quadricarinatus was used as an experimental model to evaluate the possible effects of three concentrations (25, 250 and 2500 μg/L) of NPs on red crayfish. The toxicological effects of NPs on this species were investigated based on transcriptomics and microbiome. A total of 67,668 genes were obtained from the transcriptome. The annotation rate of the four major libraries (Nr, KEGG, KOG, Swissprot) was 40.17 %, and the functions of differential genes were mainly related to antioxidant activity, metabolism and immune processes. During the experiment, the activities of superoxide dismutase (SOD) and catalase (CAT) in the high concentration group were significantly decreased, while the concentration of malondialdehyde (MDA) increased after nanoplastics (NPs) exposure, and SOD1, Jafrac1 were significantly reduced at high concentrations. expression is inhibited. The immune genes LYZ and PPO2 were highly expressed at low concentrations and suppressed at high concentrations. After 14 days of exposure to NPs, significant changes in gut microbiota were observed, such as decreased abundances of Actinobacteria, Bacteroidetes, and Firmicutes. NPs compromise host health by inducing changes in microbial communities and the production of beneficial bacterial metabolites. Overall, these results suggest that NPs affect immune-related gene expression and antioxidant enzyme activity in red crayfish and cause redox imbalance in the body, altering the composition and diversity of the gut microbiota.

Immunosuppressive landscape in hepatocellular carcinoma revealed by single-cell sequencing

Background/Aims

Hepatocellular carcinoma (HCC), accounting for 75-85% of primary liver cancer cases, is the third leading cause of cancer-related death worldwide. The purpose of this research was to examine the tumor immune microenvironment (TIME) in HCC.

Methods

We investigated the HCC TIME by integrated analysis of single-cell and bulk-tissue sequencing data to reveal the landscape of major immune cell types.

Results

Regulatory T(Treg) cells were found to be specifically distributed in the TIME of HCC. Several immune checkpoints, including TNFRSF4, TIGIT and CTLA4, were found to be uniquely overexpressed in Treg cells, and the glycolysis/gluconeogenesis pathway was enriched in Treg cells. We also discovered the presence of two NK-cell subsets with different cytotoxic capacities, one in an activated state with antitumor effects and another with an exhausted status. In addition, memory B cells in HCC were found to exist in a unique state, with high proliferation, low differentiation, and low activity, which was induced by overexpression of PRAP1 and activation of the MIF-CD74 axis.

Conclusions

We revealed the TIME landscape in HCC, highlighting the heterogeneity of major immune cell types and their potential mechanisms in the formation of an immunosuppressive environment. Hence, blocking the formation of the TIME could be a useful therapeutic strategy for HCC.

Multiple transcriptomic profiling: potential novel metabolism-related genes predict prepubertal testis damage caused by DEHP exposure

The toxic effect of di(2-ethylhexyl) phthalate (DEHP) on prepubertal testes was examined in this study. We treated 3-week-old male mice with 4.8 mg/kg/day (milligram/kilogram/day) (no observed adverse effect level), 30 mg/kg/day (high exposure dose relative to humans), 100 mg/kg/day (level causing a reproductive system disorder), and 500 mg/kg/day (dose causing a multigenerational reproductive system disorder) of DEHP via gavage. Obvious abnormalities in the testicular organ coefficient, spermatogenic epithelium, and testosterone levels occurred in the 500 mg/kg DEHP group. Ribonucleic acid sequencing (RNA-seq) showed that differentially expressed genes (DEGs) in each group could enrich reproduction and reproductive process terms according to the gene ontology (GO) results, and coenrichment of metabolism pathway was observed by the Reactome pathway analysis. Through the analysis of common genes in the metabolism pathway, we discovered that DEHP exposure at 4.8 to 500 mg/kg or 100 mg/kg caused the same damages to the prepubertal testis. In general, we identified two key transcriptional biomarkers (fatty acid binding protein 3 (Fabp3) and carboxylesterase (Ces) 1d), which provided new insight into the gene regulatory mechanism associated with DEHP exposure and will contribute to the prediction and diagnosis of prepuberty testis injury caused by DEHP.

STAT5: From Pathogenesis Mechanism to Therapeutic Approach in Acute Leukemia

BACKGROUND

Based on the results of multiple studies, multiple signaling pathways is a major cause of resistence to chemotherapy in leukemia cells. Signal transducer and activator of transcription 5 (STAT5) is among these factors; it plays an essential role in proliferation of leukemic cells.

METHODS

We obtained the materials used in our study via PubMed search from 1996 through 2019. The key search terms included "STAT5," "acute leukemia," "leukemogenesis," and "mutation."

RESULTS

On activation, STAT5 not only inhibits apoptosis of leukemic cells via activating the B-cell lymphoma 2 (BCL-2) gene but also inhibits resistance to chemotherapy by enhancing human telomerase reverse transcriptase (hTERT) expression and maintaining telomere length in cells. It has also been shown that a number of mutations in the STAT5 gene and in related genes alter the expression of STAT5.

CONCLUSION

The identification of STAT5 and the factors activated in its up- or downstream expression, affecting its function, contribute to better treatments such as targeted therapy rather than chemotherapy, improving the quality of life patients.

The Multifaceted Role of Epoxide Hydrolases in Human Health and Disease

Epoxide hydrolases (EHs) are key enzymes involved in the detoxification of xenobiotics and biotransformation of endogenous epoxides. They catalyze the hydrolysis of highly reactive epoxides to less reactive diols. EHs thereby orchestrate crucial signaling pathways for cell homeostasis. The EH family comprises 5 proteins and 2 candidate members, for which the corresponding genes are not yet identified. Although the first EHs were identified more than 30 years ago, the full spectrum of their substrates and associated biological functions remain partly unknown. The two best-known EHs are EPHX1 and EPHX2. Their wide expression pattern and multiple functions led to the development of specific inhibitors. This review summarizes the most important points regarding the current knowledge on this protein family and highlights the particularities of each EH. These different enzymes can be distinguished by their expression pattern, spectrum of associated substrates, sub-cellular localization, and enzymatic characteristics. We also reevaluated the pathogenicity of previously reported variants in genes that encode EHs and are involved in multiple disorders, in light of large datasets that were made available due to the broad development of next generation sequencing. Although association studies underline the pleiotropic and crucial role of EHs, no data on high-effect variants are confirmed to date.

Deciphering the Therapeutic Resistance in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a clonal hematopoietic disorder characterized by abnormal proliferation, lack of cellular differentiation, and infiltration of bone marrow, peripheral blood, or other organs. Induction failure and in general resistance to chemotherapeutic agents represent a hindrance for improving survival outcomes in AML. Here, we review the latest insights in AML biology concerning refractoriness to therapies with a specific focus on cytarabine and daunorubicin which still represent milestones agents for inducing therapeutic response and disease eradication. However, failure to achieve complete remission in AML is still high especially in elderly patients (40-60% in patients >65 years old). Several lines of basic and clinical research have been employed to improve the achievement of complete remission. These lines of research include molecular targeted therapy and more recently immunotherapy. In terms of molecular targeted therapies, specific attention is given to DNMT3A and TP53 mutant AML by reviewing the mechanisms underlying epigenetic therapies' (e.g., hypomethylating agents) resistance and providing critical points and hints for possible future therapies overcoming AML refractoriness.