miR-497 induces apoptosis by the IRAK2/NF-κB axis in the canine mammary tumour.

Since companion dogs have the same living environment as humans, they are a good animal model for the study of human diseases; this is especially true of canine spontaneous mammary tumours models. A better understanding of the natural history and molecular mechanisms of canine mammary tumour is of great significance in comparative medicine. Here, we collected canine mammary tumour cases and then assayed the clinical cases by pathological examination and classification by HE staining and IHC. miRNA-497 family members (miR-497, miR-16, miR-195 and miR-15) were positively correlated with the breast cancer marker genes p63 and PTEN. Modulation of the expression of miR-497 in the canine mammary tumour cell lines CMT1211 and CMT 7364 induced apoptosis and inhibited cell proliferation. Mechanistically, IRAK2 was shown to be a functional target of miR-497 that affects the characteristics of cancer cells by inhibiting the activity of the NF-κB pathway. Overall, our work reveals the miR-497/IRAK2/NF-κB axis as a vital mechanism of canine mammary tumour progression and suggests this axis as a target in breast cancer.

Alpinetin inhibits breast cancer growth by ROS/NF-κB/HIF-1α axis.

Alpinetin, the main active ingredient in the Chinese medicinal herb Alpinia katsumadai Hayata, has been found to have anticancer activity. However, the therapeutic efficacy of signalling cascades modulated by alpinetin remains unknown. Here, we showed that alpinetin provoked mitochondria-associated apoptosis in a dose-dependent manner in breast cancer cells. Mechanistic investigations revealed that alpinetin dampens hypoxia-inducible factor-1α (HIF-1α) signalling due to a lack of NF-κB activation through reduced mitochondrial reactive oxygen species (ROS) production, decreasing HIF-1α transcription. In vivo, we also found alpinetin led to significant tumour regression by inhibiting NF-κB pathway. Overall, our work uncovers a ROS/NF-κB/HIF-1α axis-dependent mechanism underlying the anticancer effects of alpinetin and suggests that alpinetin could act as a novel therapeutic agent against breast cancer.

Erratum to: Catalpol ameliorates LPS-induced endometritis by inhibiting inflammation and TLR4/NF-κB signaling.

Erratum to: J Zhejiang Univ-Sci B (Biomed & Biotechnol) 2019 2019 20(10):816-827. https://doi.org/10.1631/jzus.B1900071. The original version of this article unfortunately contained a mistake. In p.823, Figs. 8c and 8d were in-correct, and the obvious pathological changes were mistakenly placed in the picture. The correct versions should be as follows.

MicroRNA-188-5p promotes apoptosis and inhibits cell proliferation of breast cancer cells via the MAPK signaling pathway by targeting Rap2c.

Breast cancer is a common malignancy that is highly lethal with poor survival rates and immature therapeutics that urgently needs more effective and efficient therapies. MicroRNAs are intrinsically involved in different cancer remedies, but their mechanism in breast cancer has not been elucidated for prospective treatment. The function and mechanism of microRNA-188-5p (miR-188) have not been thoroughly investigated in breast cancer. In our study, we found that the expression of miR-188 in breast cancer tissues was obviously reduced. Our findings also revealed the abnormal overexpression of miR-188 in 4T1 and MCF-7 cells significantly suppressed cell proliferation and migration and also enhanced apoptosis. miR-188 induced cell cycle arrest in the G1 phase. To illuminate the molecular mechanism of miR-188, Rap2c was screened as a single target gene by bioinformatics database analysis and was further confirmed by dual-luciferase assay. Moreover, Rap2c was found to be a vital molecular switch for the mitogen-activated protein kinase signaling pathway in tumor progression by decreasing apoptosis and promoting proliferation and migration. In conclusion, our results revealed that miR-188 is a cancer progression suppressor and a promising future target for breast cancer therapy.

Hyperoside Induces Breast Cancer Cells Apoptosis via ROS-Mediated NF-κB Signaling Pathway.

Hyperoside (quercetin 3-o-ß-d-galactopyranoside) is one of the flavonoid glycosides with anti-inflammatory, antidepressant, and anti-cancer effects. But it remains unknown whether it had effects on breast cancer. Here, different concentrations of hyperoside were used to explore its therapeutic potential in both breast cancer cells and subcutaneous homotransplant mouse model. CCK-8 and wound healing assays showed that the viability and migration capability of Michigan Cancer Foundation-7 (MCF-7) and 4T1 cells were inhibited by hyperoside, while the apoptosis of cells were increased. Real-time quantitative PCR (qRT-PCR) and western blot analysis were used to detect mRNA and the protein level, respectively, which showed decreased levels of B cell lymphoma-2 (Bcl-2) and X-linked inhibitor of apoptosis (XIAP), and increased levels of Bax and cleaved caspase-3. After exploration of the potential mechanism, we found that reactive oxygen species (ROS) production was reduced by the administration of hyperoside, which subsequently inhibited the activation of NF-κB signaling pathway. Tumor volume was significantly decreased in subcutaneous homotransplant mouse model in hyperoside-treated group, which was consistent with our study in vitro. These results indicated that hyperoside acted as an anticancer drug through ROS-related apoptosis and its mechanism included activation of the Bax-caspase-3 axis and the inhibition of the NF-κB signaling pathway.

Catalpol ameliorates LPS-induced endometritis by inhibiting inflammation and TLR4/NF-κB signaling.

Catalpol is the main active ingredient of an extract from Radix rehmanniae, which in a previous study showed a protective effect against various types of tissue injury. However, a protective effect of catalpol on uterine inflammation has not been reported. In this study, to investigate the protective mechanism of catalpol on lipopolysaccharide (LPS)-induced bovine endometrial epithelial cells (bEECs) and mouse endometritis, in vitro and in vivo inflammation models were established. The Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway and its downstream inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), western blot (WB), and immunofluorescence techniques. The results from ELISA and qRT-PCR showed that catalpol dose-dependently reduced the expression of pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1ß, and IL-6, and chemokines such as C-X-C motif chemokine ligand 8 (CXCL8) and CXCL5, both in bEECs and in uterine tissue. From the experimental results of WB, qRT-PCR, and immunofluorescence, the expression of TLR4 and the phosphorylation of NF-κB p65 were markedly inhibited by catalpol compared with the LPS group. The inflammatory damage to the mouse uterus caused by LPS was greatly reduced and was accompanied by a decline in myeloperoxidase (MPO) activity. The results of this study suggest that catalpol can exert an anti-inflammatory impact on LPS-induced bEECs and mouse endometritis by inhibiting inflammation and activation of the TLR4/NF-κB signaling pathway.

Methylseleninic Acid Suppresses Breast Cancer Growth via the JAK2/STAT3 Pathway.

Previous studies show that methylseleninic acid (MSA), which is the most common selenium derivative used as a drug in humans, exerts specific cytotoxic effects in several cancer cell types. However, the complex mechanism of these effects has not been fully elucidated. Here, we demonstrate by Cell Counting Kit-8 in mouse breast cancer cell line 4T1 that MSA inhibits cell viability in a concentration-dependent (5, 10, 20 µmol/L) and time-dependent (6, 12, 24 hours) manner. Flow cytometry, Western blot, and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) analyses indicated that MSA inhibits cancer cell invasion and induces apoptosis by the activation of caspase-3, poly ADP ribose polymerase 1 (PARP1), and BCL2-associated X. Furthermore, MSA demonstrated anticancer activity by inhibiting the Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) pathway. The MSA treatment for 24 hours decreased the phosphorylation of JAK2 and STAT3 in 4T1 cells by Western blot. We also confirmed this with the use of a JAK2 chemical inhibitor, AG490, as a positive control. In a 4T1 orthotopic allograft model, morphological and TdT-mediated dUTP nick-end labeling analyses showed that MSA treatment (1.5 mg/kg/weight) for 28 days inhibits tumor growth consistent with the clinical anticancer drug cyclophosphamide. Our observations demonstrate that MSA is a potent anticancer drug in breast cancer and uncovered a key role of the JAK2/STAT3 pathway in modulating tumor growth.