Hmgb3 Induces the Differentiation of Uterine Stromal Cells Through Targeting Ptn

HMGB3 inhibition by miR-142-3p/sh-RNA modulates autophagy and induces apoptosis via ROS accumulation and mitochondrial dysfunction and reduces the tumorigenic potential of human breast cancer cells

AIMS

High mobility group box (HMGB) family proteins, HMGB1, HMGB2, HMGB3, and HMGB4 are oncogenic. The oncogenic nature of HMGB1 is characterized by its association with autophagy, ROS, and MMP. Since HMGB3 is its paralog, we hypothesized that it might also modulate autophagy, ROS, and MMP. Hence, we targeted HMGB3 using its shRNA or miR-142-3p and assessed the changes in autophagy, ROS, MMP, and tumorigenic properties of human breast cancer cells.

MAIN METHODS

Cell viability was assessed by resazurin staining and annexin-V/PI dual staining was used for confirming apoptosis. Colony formation, transwell migration, invasion and luciferase reporter (for miRNA-target validation) assays were also performed. ROS and MMP were detected using DHE and MitoTracker dyes, respectively. A zebrafish xenograft model was used to assess the role of miR-142-3p on in vivo metastatic potential of breast cancer cells.

KEY FINDINGS

Breast cancer tissues from Indian patients and TCGA samples exhibit overexpression of HMGB3. miR-142-3p binds to 3' UTR of HMGB3, leading to its downregulation that subsequently inhibits colony formation and induces apoptosis involving increased ROS accumulation and decreased MMP, phospho-mTOR and STAT3. Our findings show that HMGB3 is directly involved in the miR-142-3p-mediated disruption of autophagy and induction of apoptotic cell death via modulation of LC3, cleaved PARP and Bcl-xL. In addition, miR-142-3p inhibited migration, invasion and metastatic potential of breast cancer cells.

SIGNIFICANCE

Our findings highlighted the role of HMGB3, for the first time, in the modulation of autophagy and apoptosis in human breast cancer cells, and these results have therapeutic implications.

High-mobility group box 3 (HMGB3) silencing inhibits non-small cell lung cancer development through regulating Wnt/β-catenin pathway

It has been reported that high-mobility group box 3 is overexpressed in various cancers. This study aimed to explore its function in non-small cell lung cancer (NSCLC). A546 and H460 cell lines were used for in vivo experiments, scratch healing tests, transwell migration and invasion experiments. It was first found that HMGB3 was highly expressed in tumor tissues in the patients and associated with NSCLC stage. Silencing of HMGB3 significantly slowed the growth, proliferation and invasion of NSCLC in vitro, and repressed cell growth in vivo. Mechanistic studies suggest that the observed effects were mediated by inhibiting the expression of β-catenin/MMP7/c-Myc in Wnt pathway. Our study highlights the role of HMGB3 in NSCLC, which may provide a therapeutic target for the treatment of NSCLC.

Screening of Potential Key Genes Related to Tubal Factor Infertility Based on Competitive Endogenous RNA Network

Background: The molecular biological mechanism of tubal factor infertility (TFI) is still unclear. Long noncoding RNAs (lncRNAs) are considered a major part of the competitive endogenous RNA (ceRNA) network and have attracted growing attention. Our study aimed to explore the regulatory mechanisms of lncRNAs associated with TFI and screen potential key genes related to TFI. Materials and Methods: Differentially expressed lncRNAs (DELs) and differentially expressed genes (DEGs) were identified by comparing normal and TFI expression patterns of lncRNAs and mRNAs in eutopic endometrial tissues obtained from 3 normal and 3 TFI patients during implantation. These data were used to develop a protein-protein interaction (PPI) network of DEGs using the STRING online software. The identified DELs and DEGs were then used to construct a ceRNA network, and the Network Analyzer Tool Kit in Cytoscape was used to analyze the ceRNA network topology and stability. Finally, the overlapping genes present in both the ceRNA and PPI networks were selected as the potential key genes related to TFI. Results: Ninety-six DEGs (59 up and 37 down) and 45 DELs (28 up and 17 down) were identified. Thirty-four DEGs were mapped in a PPI network. A ceRNA network, including two lncRNAs (LINC00305 and DLX6-AS1), four microRNAs (hsa-miR-20b-5p, hsa-miR-17-5p, hsa-miR-107, and hsa-miR-24-3p), and four mRNAs (MAP3K3, HMGB3, FAM103A1, and TMEM209), was successfully constructed. Importantly, a potential key gene (TMEM209) related to TFI was identified. Conclusion: The construction of a ceRNA network related to TFI may help elucidate the regulatory mechanism by which genes and lncRNAs function as ceRNA networks. Importantly, TMEM209 may be further evaluated as potential therapeutic targets for TFI.

The role of high mobility group protein B3 (HMGB3) in tumor proliferation and drug resistance

The high mobility group protein B (HMGB) family (including HMGB1, HMGB2, HMGB3, and HMGB4) can regulate the mechanisms of DNA replication, transcription, recombination, and repair, and act as cytokines to mediate responses to infection, injury, and inflammation. HMGB1/2/3 has a high similarity in sequence and structure, while HMGB4 has no acidic C-terminal tail. Among them, HMGB3 can regulate the self-renewal and differentiation of normal hematopoietic stem cell population, but the decrease of its expression is easy to induce leukemia. Up-regulation of its expression promotes tumor development and chemotherapy resistance through a variety of mechanisms, and non-coding RNA can regulate to promote tumor cell proliferation, invasion, and migration and inhibit cancer cell apoptosis.