Skullcapflavone I suppresses proliferation of human lung cancer cells via down-regulating microRNA-21.

Lung cancer is the most leading cause of cancer-related deaths worldwide. Skullcapflavone I is a flavone compound extracted from Scutellaria baicalensis Georgi (Wogon). The present study investigated the effects of skullcapflavone I on human lung cancer cell proliferation, as well as underlying possible mechanism. Cell proliferation was detected using Trypan blue assay. Cell viability was measured using cell counting kit 8 (CCK-8) assay. Quantitative reverse transcription PCR (qRT-PCR) was performed to assess microRNA-21 (miR-21) expression. Cell transfection was conducted to enhance the levels of miR-21 and protein phosphatase 2A (PP2A). Western blotting was used to evaluate the expressions of proliferation cell nuclear antigen (PCNA), Cyclin D1, PP2A, phosphatidylinositol 3-kinase (PI3K), protein kinase 3 (AKT), mechanistic target of rapamycin (mTOR) and p70S6K. Skullcapflavone I significantly suppressed the viability and proliferation of A549 and H1975 cells. The expressions of miR-21 in A549 and H1975 cells were drastically decreased after skullcapflavone I treatment. Overexpression of miR-21 remarkably reversed the skullcapflavone I-induced A549 cell viability inhibition. Moreover, skullcapflavone I enhanced the expression of PP2A in A549 cells. Skullcapflavone I inactivated PI3K/AKT/mTOR signaling pathway in A549 cells via up-regulating PP2A. Besides, skullcapflavone I treatment had no significant influence on human normal bronchial epithelial 16HBE cell viability, proliferation and apoptosis. Skullcapflavone I exerted anti-cancer effect on lung cancer cells by down-regulating miR-21 expression, up-regulating PP2A expression and then inactivating PI3K/AKT/mTOR signaling pathway.

Yang Y ，An R ，Feng T ，Qin X ，Zhang J ，Bo Y ，Niu B ... -  《-》

Kaempferol inhibits proliferation, migration, and invasion of liver cancer HepG2 cells by down-regulation of microRNA-21.

Zhu G ，Liu X ，Li H ，Yan Y ，Hong X ，Lin Z ... -  《-》

microRNA-383 suppresses the PI3K-AKT-MTOR signaling pathway to inhibit development of cervical cancer via down-regulating PARP2.

This study aims to evaluate the effect of the regulatory relationship between microRNA-383 (miR-383) and PARP2 in the cell migration and invasion in human with cervical cancer (CC) via the PI3K-AKT-MTOR signaling pathway. Cancerous tissues and corresponding paracancerous tissues were collected from 115 patients with CC. The positive expression rate of PARP2 was detected by immunohistochemistry. HeLa cells with highest miR-383 expression were selected and assigned into the blank, negative control (NC), miR-383 mimic, miR-383 inhibitor, si-PARP2, and miR-383 inhibitor + si-PARP2 groups. qRT-PCR and Western blot were performed to evaluate the expression of miR-383, PI3K, AKT, mTOR, PARP2, and p70S6K. MTT assay were utilized to measure cell viability. Transwell assay were applied to evaluate cell invasion and metastasis. Dual luciferase reporter assay identified that PARP2 is a target gene of miR-383. Cancerous tissues manifested higher expression of PI3K, AKT, mTOR, PARP2, and p70S6K but lower miR-383 expression than paracancerous tissues. Compared with the blank and NC groups, the miR-383 mimic and si-PARP2 groups had decreased expression of PI3K, AKT, mTOR, PARP2, and p70S6K mRNA and protein. In the miR-383 mimic and si-PARP2 groups, the cell viability, migration, and invasion were descended, in comparison to the blank and NC groups. All above parameters showed an opposite trend in the miR-383 inhibitor group when compared with the blank and NC groups. This study demonstrates that miR-383 could down-regulate PARP2 to protect against CC by inhibiting PI3K-AKT-MTOR signaling pathway.

Teng P ，Jiao Y ，Hao M ，Tang X ... -  《-》

Effect of microRNA-135a on Cell Proliferation, Migration, Invasion, Apoptosis and Tumor Angiogenesis Through the IGF-1/PI3K/Akt Signaling Pathway in Non-Small Cell Lung Cancer.

This study explored the ability of microRNA-135a (miR-135a) to influence cell proliferation, migration, invasion, apoptosis and tumor angiogenesis through the IGF-1/PI3K/Akt signaling pathway in non-small cell lung cancer (NSCLC). NSCLC tissues and adjacent normal tissues were collected from 138 NSCLC patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-135a and IGF-1, PI3K, Akt, VEGF, bFGF and IL-8 mRNA; western blotting was used to determine the expression levels of IGF-1, PI3K and Akt protein; and enzyme-linked immunosorbent assay (ELISA) was used to analyze the expression levels of VEGF, bFGF and IL-8 protein. Human NSCLC cell lines (A549, H460, and H1299) and the human bronchial epithelial cell line (HBE) were selected. A549 cells were assigned to blank, negative control (NC), miR-135a mimics, miR-135a inhibitors, IGF-1 siRNA and miR-135a inhibitors + IGF-1 siRNA groups. The following were performed: an MTT assay to assess cell proliferation, a scratch test to detect cell migration, a Transwell assay to measure cell invasion, and a flow cytometry to analyze cell apoptosis. The expression level of miR-135a was lower while those of IGF-1, PI3K and Akt mRNA were higher in NSCLC tissues than in the adjacent normal tissues. Dual-luciferase reporter assay indicated IGF-1 as a target of miR-135a. The in vitro results showed that compared with the blank group, cell proliferation, migration and invasion were suppressed, mRNA and protein levels of IGF-1, PI3K, Akt, VEGF, bFGF and IL-8 were reduced, and cell apoptosis was enhanced in the miR-135a mimics and IGF-1 siRNA groups. Compared with the IGF-1 siRNA group, cells in the miR-135a inhibitors + IGF-1 siRNA group demonstrated increased cell proliferation, migration and invasion, elevated mRNA and protein levels of IGF-1, PI3K, Akt, VEGF, bFGF and IL-8 and reduced cell apoptosis. These findings indicated that miR-135a promotes cell apoptosis and inhibits cell proliferation, migration, invasion and tumor angiogenesis by targeting IGF-1 gene through the IGF-1/PI3K/Akt signaling pathway in NSCLC.

Zhou Y ，Li S ，Li J ，Wang D ，Li Q ... -  《-》

MicroRNA-99b suppresses human cervical cancer cell activity by inhibiting the PI3K/AKT/mTOR signaling pathway.

Cervical cancer is common cancer among women with high morbidity. MicroRNAs (miRs) are involved in the progression and development of cervical cancer. This study aimed to explore the effect of miR-99b-5p (miR-99b) on invasion and migration in cervical cancer through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway. The microarray-based analysis was used to screen out differentially expressed miRNAs. Expression of miR-99b, PI3K, AKT, mTOR, and ribosomal protein S6 kinase (p70S6K) was determined in both cervical cancer tissues and paracancerous tissues. Next, alteration of miR-99b expression in cervical cancer was conducted to evaluate levels of PI3K, AKT, mTOR, p70S6K matrix metallopeptidase 2, epithelial cell adhesion molecule, and intercellular adhesion molecule 1, as well as the effect of miR-99b on cell proliferation, invasion, migration, cell cycle distribution, and apoptosis. The results demonstrated that miR-99b expression was decreased and levels of PI3K, AKT, mTOR, and p70S6K were elevated in cervical cancer tissues. More important, overexpressed miR-99b repressed the PI3K/AKT/mTOR signaling pathway, inhibited cell proliferation, invasion, and migration, blocked cell cycle entry, and promoted apoptosis in cervical cancer. These results indicate that miR-99b attenuates the migration and invasion of human cervical cancer cells through downregulation of the PI3K/AKT/mTOR signaling pathway, which provides a therapeutic approach for cervical cancer treatment.

Li YJ ，Wang Y ，Wang YY 《-》