miR-31-5p may enhance the efficacy of chemotherapy with Taxol and cisplatin in TNBC

Synthesis and Discovery of Ligustrazine–Heterocycle Derivatives as Antitumor Agents

Ligustrazine (TMP) is a natural pyrazine alkaloid extracted from the roots of Ligusticum Chuanxiong Hort, which has the potential as an antitumor agent. A series of 33 ligustrazine–heterocycle (TMPH) derivatives were designed, synthesized, and investigated via antitumor screening assays, molecular docking analysis, and prediction of drug-like properties. TMP was attached to other heterocyclic derivatives by an 8–12 methylene alkyl chain as a linker to obtain 33 TMPH derivatives. The structures were confirmed by ¹H-NMR, ¹³C-NMR, and high-resolution mass spectroscopy spectral (HR-MS) data. The antiproliferative activity against human breast cancer MCF-7, MDA-MB-231, mouse breast cancer 4T1, mouse fibroblast L929, and human umbilical vein endothelial HUVEC cell lines was evaluated by MTT assay. Compound 12–9 displayed significant inhibitory activity with IC₅₀ values in the low micromolar range (0.84 ± 0.02 µM against the MDA-MB-231 cell line). The antitumor effects of compound 12–9 were further evaluated by plate cloning, Hoechst 33 342 staining, and annexin V-FITC/PI staining. The results indicated that compound 12–9 inhibited the proliferation and apoptosis of breast cancer cells. Furthermore, molecular docking of compound 12–9 into the active site of the Bcl-2, CASP-3, and PSMB5 target proteins was performed to explore the probable binding mode. The 33 newly synthesized compounds were predicted to have good drug-like properties in a theoretical study. Overall, these results indicated that compound 12–9 inhibited cell proliferation through PSMB5 and apoptosis through Bcl-2/CASP-3 apoptotic signaling pathways and had good drug-like properties. These results provided more information, and key precursor lead derivatives, in the search for effective bioactive components from Chinese natural medicines.

miR-31-5p Promotes Oxidative Stress and Vascular Smooth Muscle Cell Migration in Spontaneously Hypertensive Rats via Inhibiting FNDC5 Expression

Oxidative stress and the migration of vascular smooth muscle cells (VSMCs) are important for vascular remodeling in a variety of vascular diseases. miR-31-5p promotes cell migration in colorectal cancer cells but inhibits cell migration in renal cell carcinoma. However, whether miR-31-5p is involved in oxidative stress and VSMC migration remains unknown. This study shows the crucial roles of miR-31-5p in oxidative stress and VSMC migration, as well as underlying mechanisms. Experiments were carried out in primary VSMCs from aortic media of Wistar–Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), as well as the A7r5 cell line. Oxidative stress was assessed by NADPH oxidase (NOX) expression, NOX activity, and reactive oxygen species (ROS) production. Cell migration was evaluated with a Boyden chamber assay and a wound healing assay. The miR-31-5p mimic and inhibitor promoted and attenuated oxidative stress and cell migration in the VSMCs of SHR, respectively. A dual-luciferase reporter assay indicated that miR-31-5p targeted the 3’UTR domain of FNDC5. The miR-31-5p level was raised and FNDC5 expression was reduced in the VSMCs of SHR compared with those of WKY. The miR-31-5p mimic reduced FNDC5 expression in the A7r5 cells and the VSMCs of both WKY and SHR, while the miR-31-5p inhibitor only increased FNDC5 expression in the VSMCs of SHR. Exogenous FNDC5 attenuated not only the oxidative stress and VSMC migration in SHR but also the roles of the miR-31-5p mimic in inducing oxidative stress and VSMC migration. These results indicate that miR-31-5p promotes oxidative stress and VSMC migration in SHR via inhibiting FNDC5 expression. The increased miR-31-5p and reduced FNDC5 in the VSMCs of SHR contribute to enhanced oxidative stress and cell migration.

Research on correlations of miR-585 expression with progression and prognosis of triple-negative breast cancer

Triple-negative breast cancer is a special type of breast cancer, characterized by younger onset age, shorter survival period, higher malignant degree, higher mortality, recurrence and metastasis. Triple-negative breast cancer is more harmful to women's life and health, compared with other types of breast cancer. This paper mainly studied the role of miR-585 in triple-negative breast cancer. Real-time quantitative PCR was used to detect the expression of miR-585 in triple-negative breast cancer cell lines and tissues. Kaplan-Meier curve and Cox proportional hazards model analysis were used to investigate the prognostic value of miR-585 in triple-negative breast cancer. CCK-8 and Transwell assays were used to detect cell proliferation, invasion and migration. miR-585 was significantly down-regulated in triple-negative breast cancer cells and tissues. The low expression of miR-585 has been shown to be significantly associated with poor prognosis in triple-negative breast cancer patients. Abnormally low expression of miR-585 can promote cell proliferation, migration and invasion. Overall, abnormally low expression of miR-585 is associated with prognosis and progression of triple-negative breast cancer. miR-585 may serve as a prognostic biomarker for patients with triple-negative breast cancer and it is expected to be a new method and strategy for the treatment of triple-negative breast cancer.

Suppression of Long Non-Coding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1) Potentiates Cell Apoptosis and Drug Sensitivity to Taxanes and Adriamycin in Breast Cancer

BACKGROUND The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is expressed highly in various types of tumors. Moreover, the tumor-initiating role of MALAT1 has been probed in the context of breast cancer. This study was set to investigate the regulatory role of MALAT1 on the chemosensitivity of breast cancer cells to taxanes (Tax) and adriamycin (Adr). MATERIAL AND METHODS Following the measurement of MALAT1 expression in patients with breast cancer by means of qRT-PCR, the connection between the MALAT1 expression pattern and the prognosis of breast cancer patients as well as the molecular typing of breast cancer patients was analyzed using Kaplan-Meier survival analysis and receiver operating characteristic (ROC) curves. Next, the analysis between the expression of MALAT1 and the clinical symptoms of breast cancer patients was carried out. Subsequently, we generated taxane-resistant MCF-7 cells (MCF-7/Tax) and purchased Adr-resistant MCF-7 cells (MCF-7/Adr). Finally, the proliferation, apoptosis and drug resistance of resistant and parental cells were evaluated after transfection of silencing MALAT1 into these cells. RESULTS MALAT1 was highly expressed in the breast cancer tissues. Moreover, patients with relative overexpression of MALAT1 had worse prognosis. MALAT1 expression was remarkably promoted in MCF-7/Tax and MCF-7/Adr cells, whose sensitivity to Tax and Adr was enhanced following MALAT1 knockdown. CONCLUSIONS MALAT1 was elevated in breast cancer tissues and MCF-7-resistant cells, relative to corresponding controls and downregulation of MALAT1 inhibited the growth and chemoresistance of breast cancer cells to Tax and Adr.

PEX5, a novel target of microRNA-31-5p, increases radioresistance in hepatocellular carcinoma by activating Wnt/β-catenin signaling and homologous recombination

Rationale: Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide, with high recurrence and metastasis rates. Although radiation is an effective treatment for tumors, it is often limited by intrinsic radioresistance in HCC. The contributions of dysregulated microRNAs, including miR-31-5p, to HCC progression have been recently reported. However, the role of miR-31-5p in the radiation response of HCC is unknown. In this study, we aimed to investigate the impact of miR-31-5p on HCC radiosensitivity.

Methods: miR-31-5p expression in HCC tissues, paired adjacent tissues, and HCC cell lines was measured using quantitative real-time polymerase chain reaction and in situ hybridization. Bioinformatic analyses, gain- and loss-of-function experiments, and luciferase reporter assays were performed to validate peroxisomal biogenesis factor 5 (PEX5) as a direct target of miR-31-5p. The biofunctions of PEX5 and miR-31-5p in HCC were determined by Transwell, wound-healing, and Cell Counting Kit-8 (CCK8) assays. A colony formation assay was used to evaluate the radiosensitivity of HCC cells. The interaction among PEX5, β-catenin, Rac1, and JNK-2 was confirmed by coimmunoprecipitation. A xenograft tumor model was established to validate the effects of miR-31-5p and PEX5 on HCC progression and radiosensitivity in vivo.

Results: Low expression of miR-31-5p in HCC specimens, as observed in this study, predicted a poor clinical outcome. However, the expression pattern of PEX5, as a direct target of miR-31-5p, was opposite that of miR-31-5p, and high PEX5 expression indicated poor prognosis in HCC patients. Ectopic expression of PEX5 increased the proliferation, migration, and invasion abilities and enhanced the radioresistance of HCC cells in vitro and in vivo; however, these phenotypes were inhibited by miR-31-5p. Mechanistically, PEX5 stabilized cytoplasmic β-catenin and facilitated β-catenin nuclear translocation to activate Wnt/β-catenin signaling. Moreover, upon radiation exposure, PEX5 reduced excessive reactive oxygen species (ROS) accumulation and activated the homologous recombination (HR) pathway, which protected HCC cells from radiation-induced damage.

Conclusions: Our findings demonstrated a novel role for PEX5 as a miR-31-5p target and a mediator of the Wnt/β-catenin signaling and HR pathways, providing new insights into studying HCC radiation responses and implicating PEX5 and miR-31-5p as potential therapeutic targets in HCC.