High-mobility group box 2 promoted proliferation of cervical cancer cells by activating AKT signaling pathway

Cervical cancer is one of the leading killers for female worldwide. Nevertheless, the less knowledge of molecular mechanism for cervical cancer limited the improvement of treatment effects. High-mobility group box 2 (HMGB2) belongs to the HMGB family, which could play diverse roles in cell proliferation. This work mainly aimed to study the functions of HMGB2 on cervical cancer cells proliferation. HMGB2 was highly expressed in cervical cancer tissue. The results of real-time polymerase chain reaction and Western blot analysis showed that HMGB2 was expressed in all the five cervical cancer cells (HeLa, CaSki, SiHa, C-33A, and C4-1 cells). In addition, HMGB2 overexpression obviously improved cell viability and promoted cell cycle progression, which suggested that HMGB2 could promote proliferation of cervical cancer cells. Moreover, HMGB2 overexpression increased the level of p-AKT and reduced the levels of p21 and p27. However, HMGB2 downregulation had contrary influences on cell proliferation, cell cycle distribution and the levels of p-AKT, p21, and p27. Notably, LY294002, as an inhibitor of AKT signaling pathway, could significantly weaken the effects of HMGB2 overexpression, which indicated that HMGB2 might promote cell proliferation by activating AKT signaling pathway. Therefore, HMGB2 was hopeful to be a candidate as a new biomarker and therapy target for cervical cancer.     

Silencing of RHEB inhibits cell proliferation and promotes apoptosis in colorectal cancer cells via inhibition of the mTOR signaling pathway

Colorectal cancer (CRC) is commonly known as one of the most prominent reasons for cancer-related death in China. Ras homolog enriched in brain (RHEB) and the mammalian target activity of rapamycin (mTOR) signaling pathway were found correlated with CRC, but their specific interaction in CRC was still to be investigated. Therefore, we explored whether RHEB gene silencing affected the cell proliferation, differentiation, and apoptosis by directly targeting the mTOR signaling pathway in cells previously harvested from CRC patients. A microarray analysis was subsequently conducted to investigate the relationship between RHEB and mTOR. Eighty-three adjacent normal tissues and CRC tissues were selected. Immunohistochemistry was carried out to detect the positive expression rates of RHEB and Ki-67 in the CRC tissues. Cells were then transfected with different siRNAs to investigate the potential effects RHEB would have on CRC progression. The expressions of RHEB, 4EBP1, ribosomal protein S6 kinase (p70S6K), proliferating cell nuclear antigen (PCNA), B cell lymphoma 2 (bcl-2), and bcl-2-associated X protein (bax) were determined and then the cell cycle, cell proliferation, and apoptotic rate were also measured. We identified RHEB and mTOR as upregulated genes in CRC. Cells treated with RHEB silencing showed a decreased extent of mTOR, p70S6K, 4EBP1 phosphorylation and expression of RHEB, Ki-67, mTOR, p70S6K, 4EBP1, bcl-2, and PCNA as well as decreased activity of cell proliferation and differentiation; although, the expression of bax was evidently higher. Collectively, our data propose the idea that RHEB gene silencing might repress cell proliferation and differentiation while accelerating apoptosis via inactivating the mTOR signaling pathway.     

Retracted: Sapylin inhibits lung cancer cell proliferation and promotes apoptosis by attenuating PI3K/AKT signaling

Sapylin (OK-432) revealed biological properties in cancers. In this study, the effect of sapylin on lung cancer cell A549 was investigated. A549 cell lines were treated with sapylin (0.1, 0.5, and 1 KE/mL) for different time intervals. A549 cell proliferation and apoptosis was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide/Ki67 assay and flow cytometry, respectively. Western blot was used to determine the expressions of proteins involved in proliferation, apoptosis, and phosphoinositide 3-kinase/serine/threonine kinase (PI3K/AKT), Wnt3a/β-catenin signaling pathway. Level of intracellular reactive oxygen species (ROS) was insured by using the ROS kit. Sapylin inhibited A549 cell viability and the expressions of proliferation-related proteins (cyclin E1 and D1) in dose- and time-dependent manners. Sapylin promoted apoptosis in a dose- and time-dependent manners. Sapylin also promoted the expressions of apoptotic proteins (cleaved caspase-3 and 8) in dose- and time-dependent manners. Furthermore, sapylin increased the intracellular concentration of ROS in a dose-dependent manner. Besides, the high expression of ROS level might induce inhibition of cell viability and increase cell apoptosis. The mechanistic study revealed that sapylin inactivated the PI3K/AKT and Wnt3a/β-catenin signaling pathways. Our findings suggest that sapylin inhibits proliferation and promotes apoptosis in lung cancer cells, thus providing a new theoretical basis for the treatment of lung cancer.     

MCM7 silencing promotes cutaneous melanoma cell autophagy and apoptosis by inactivating the AKT1/mTOR signaling pathway

Cutaneous melanoma (CM) has become a major public health concern. Studies illustrate that minichromosome maintenance protein 7 (MCM7) participate in various diseases including skin disease. Our study aimed to study the effects of MCM7 silencing on CM cell autophagy and apoptosis by modulating the AKT threonine kinase 1 (AKT1)/mechanistic target of rapamycin kinase (mTOR) signaling pathway. Initially, microarray analysis was used to screen the CM-related gene expression data as well as differentially expressed genes. Subsequently, MCM7 expression vector and lentivirus RNA used for MCM7 silencing (LV-shRNA-MCM7) were constructed, and these vectors, dimethyl sulfoxide (DMSO) and AKT activator SC79 were then introduced into CM cell line SK-MEL-2 to validate the role of MCM7 in cell autophagy, viability, apoptosis, cell cycle, migration, and invasion. To further investigate the regulatory mechanisms of MCM7 in CM progress, the expression of MCM7, AKT1, mTOR, cyclin D1, as well as autophagy and apoptosis relative factors, such as LC3B, SOD2, DJ-1, p62, Bcl-2, Bax, and caspase-3 in melanoma cells was determined. MCM7 might mediate the AKT1/mTOR signaling pathway to influence the progress of melanoma. MCM7 silencing contributed to the increased expression of Bax, capase-3, and autophagy-related genes (LC3B, SOD2, and DJ-1), but decreased the expression of Bcl-2, which suggested that MCM7 silencing promoted autophagy and cell apoptosis. At the same time, MCM7 silencing also attenuated cell viability, invasion, and migration, and reduced the cyclin D1 expression and protein levels of p-AKT1 and p-mTOR. Taken together, MCM7 silencing inhibited CM via inactivation of the AKT1/mTOR signaling pathway.     

PLS3 predicts poor prognosis in pancreatic cancer and promotes cancer cell proliferation via PI3K/AKT signaling

Plastin-3 plays a key role in cancer cell proliferation and invasion, but its prognostic value in pancreatic cancer (PACA) remains poorly defined. In this study, we show that PLS3 messenger RNA is overexpressed in PACA tissue compared with normal tissue. We accumulated 207 cases of PACA specimens to perform immunohistochemical analysis and demonstrated that PLS3 levels correlate with T-classification (p < .001) and pathology (p < .001). Furthermore, overall survival rates (p < .001) in tumors with high PLS3 expression were poor, as assessed through Kaplan–Meier survival analysis. PLS3 was found to be an independent prognostic factor for PACA through multivariate Cox regression analysis. Moreover, we found that PLS3 enhances the proliferation and invasion of tumor cells as assessed through Cell Counting Kit-8, wounding healing assays, and Transwell assays. The upregulation of PLS3 also led to enhanced phosphatidylinositol-3 kinase/protein kinase B signaling in PACA cells. These data suggest that PLS3 is a biomarker to estimate PACA progression and represents a molecular target for PACA therapy.     

VLX1570 regulates the proliferation and apoptosis of human lung cancer cells through modulating ER stress and the AKT pathway

The ubiquitin‐proteasome system (UPS) possesses unique functions in tumorigenesis and has great potential for targeting tumours. The effectiveness of inhibitors targeting UPS in solid tumours remains to be studied. We screened a library of inhibitors targeting the ubiquitination system and found the highly potent, low‐concentration inhibitor molecule VLX1570 that specifically killed lung cancer cells. VLX1570 is an inhibitor of deubiquitinating enzyme activity and has also shown potential for preclinical cancer treatment. We found that VLX1570 significantly inhibited lung cancer cells proliferation and colony formation. VLX1570 induced a G2/M cell cycle arrest by downregulating CDK1 and CyclinB1. Moreover, VLX1570 significantly promoted the mitochondrial‐associated apoptosis. Mechanistically speaking, VLX1570 activated the PERK/IRE1/ATF6 pathway and induced ER stress in lung cancer cell lines. The inhibition of ER stress by tauroursodeoxycholic acid sodium or 4‐phenylbutyric acid enhanced VLX1570‐induced apoptosis. In addition, VLX1570 treatment led to the inactivation of Akt signalling and inhibited the proliferation of lung cancer cells by downregulating the Akt pathway. Moreover, combined treatment with VLX1570 and Afatinib or Gefitinib induced synergistic anti‐lung cancer activity. Our present study demonstrated a novel therapy using VLX1570, which inhibited the proliferation and increased apoptosis in human lung cancer.     

Knockdown of interferon-induced transmembrane protein 1 inhibited proliferation,induced cell cycle arrest and apoptosis,and suppressed MAPK signaling pathway in pancreatic cancer cells

ABSTRACT

Pancreatic cancer (PC), highly malignant, is one of the most lethal cancers. Interferon-induced transmembrane protein 1 (IFITM1) has recently been regarded as a new molecular marker in human cancers. However, the role of IFITM1 in PC remains unclear. In this study, a short hairpin RNA (shRNA) was constructed to assess the effect of IFITM1 on PANC-1 and ASPC-1 cells. The level of IFITM1 was downregulated in cells transfected with shRNA targeting IFITM1 (sh-IFITM1). Silencing of IFITM1 significantly decreased cell viability, downregulated the level of Ki-67, arrested cell at G1/S phase, reduced the number of cells in S phase, and decreased cyclinD1, cyclinE, CDK2, and CDK4 levels. Moreover, Hoechst staining and Western blotting analysis showed that cell apoptosis was induced by IFITM1. IFITM1 knockdown suppressed the MAPK signaling pathway by downregulation of p-ERK, p-P38, and p-JNK levels. These findings suggested that IFITM1 could be considered a potential therapeutic target for PC.     

miR-21 promotes proliferation and inhibits apoptosis of hepatic stellate cells through targeting PTEN/PI3K/AKT pathway

Abstract

To investigate the effect of microRNA 21 (miR-21) on hepatic stellate cells (HSCs) proliferation and apoptosis, and further to study its potential mechanisms. LX-2 cells were divided into miR-21 mimic group (Mimic), miR-21 mimic negative control group (NM), miR-21 inhibitor group (Inhibitor), miR-21 inhibitor negative control group (NC), and blank control group (Control). The cell proliferation was detected by CCK-8 assay and the cell migration and invasion were detected by scratch and transwell assay. Cell cycle and apoptosis were detected by flow cytometry. The levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β1 were detected by enzyme-linked immunosorbent assay (ELISA). Proliferation, apoptosis, and phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway related genes and proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. The cells proliferation, migration, and invasion were promoted in Mimic group. The levels of IL-6, TNF-α, and TGF-β1 were increased after miR-21 administration. The expression of α-smooth muscle actin (SMA) and collagen 1 (Colla1) were increased, while Bax/B-cell lymphoma (Bcl)-2 ratio and programed cell death 4 (PDCD4) were reduced after miR?21 treatment. Meanwhile, the mRNA and protein expression of PTEN were reduced and PI3K/AKT pathway been promoted. Our study demonstrated that miR-21 could promote proliferation and inhibit apoptosis of HSCs, and its mechanism may be related to PTEN/PI3K/AKT pathway.     

TGF-beta2 inhibits AKT activation and FGF-2-induced corneal endothelial cell proliferation

The corneal endothelial cells form a boundary layer between anterior chamber and cornea. This single cell layer is important to maintain cornea transparency by eliciting net fluid transport into the anterior chamber. Injuries of the corneal endothelial layer in humans lead to corneal swelling and translucence. This hindrance is thought to be due to limited proliferative capacity of the endothelial layer. Fibroblast growth factor 2 (FGF-2) and transforming growth factor-beta 2 (TGF-beta2) are both found in aqueous humor, and these two cytokines promote and inhibit cell growth, respectively. The intracellular signaling mechanisms by which TGF-beta2 suppresses the mitogenic response to FGF-2, however, remain unclear. We have addressed this question by investigating potential crosstalk between FGF-2-induced and TGF-beta2-regulated intracellular signaling events in cultured bovine corneal endothelial (BCE) cells. We found that TGF-beta2 and FGF-2 oppositely affect BCE cell proliferation and TGF-beta2 can override the stimulating effects of FGF-2 by increasing COX-2 expression in these cells. Consistent with these findings, overexpression of COX-2 significantly reduced FGF-2-induced cell proliferation whereas a COX-2 specific inhibitor NS398 reversed the effect of TGF-beta2 on FGF-2-induced cell proliferation. The COX-2 product prostaglandin E2 (PGE-2) blocks FGF-2-induced cell proliferation. Whereas FGF-2 stimulates cell proliferation by activating the AKT pathway, TGF-beta2 and PGE-2 both inhibit this pathway. In accordance with the effect of PGE-2, cAMP also inhibits FGF-2-induced AKT activation. These findings suggest that the mitogenic response to FGF-2 in vivo in the corneal endothelial layer may be inhibited by TGF-beta2-induced suppression of the PI3-kinase/AKT signaling pathway.     

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.     

The lncRNA SNHG15/miR-18a-5p axis promotes cell proliferation in ovarian cancer through activating Akt/mTOR signaling pathway

Here, we report the expression pattern, function and regulatory mechanism of SNHG15 together with miR-18a-5p micro RNA in ovarian cancer (OC) for the first time. We recruited 20 patients and took normal ovarian tissues and ovarian tumor tissues from them. We used cell culture, transfection, in vivo tumor xenograft assay, and multiple types of detection assays to investigate the expression and regulation of long noncoding RNA (lncRNA) SNHG15/miR-18a-5p in ovarian tissues and cells. Results: We found that the messenger RNA expression level of SNHG15 was significantly higher and miR-18 was decreased in ovarian cancer tissues and in OC cells. Functional experiments showed that SNHG15 overexpression potentiated the migration and invasion of OC cells, while SNHG15 inhibition reduced the tumor proliferation, which was restored via overexpression of miR-18a. SNHG15 was found to directly target and suppress the expression of miR-18a. Our results illustrate the possible molecular mechanism of lncRNA SNHG15/miR-18a-5p functions in cell proliferation in OC. SNHG15/miR-18a promoted the progression of OC cells via the protein kinase B/mammalian target of rapamycin signaling pathway.     

Ropivacaine inhibits proliferation and invasion and promotes apoptosis and autophagy in bladder cancer cells via inhibiting PI3K/AKT pathway

Application of a certain concentration of local anesthetics during tumor resection inhibits the progression of tumor. The effects of ropivacaine in bladder cancer (BC) have never been explored. We explored the effects of ropivacaine on the progression of BC in vitro and in vivo. CCK8 assay and EDU staining was conducted to examine cell proliferation. Flow cytometry and transwell assay were performed to evaluate apoptosis and invasion, respectively. Expression of light chain 3 (LC3) was observed through immunofluorescence. Furthermore, the xenograft tumor model of BC was built to detect the effects of ropivacaine in vivo. IHC and TUNEL assay were conducted to detect cell proliferation and apoptosis in vivo. Ropivacaine inhibited the proliferation of T24 and 5639 cells with the 50% inhibitory concentration (IC50) of 20.08 and 31.86 µM, respectively. Ropivacaine suppressed the invasion ability and induces the apoptosis of cells. Besides, ropivacaine triggers obvious autophagy in BC cells. Moreover, ropivacaine blocks the PI3K/AKT signal pathway in BC cells. The impact of ropivacaine on cell viability, motility, and autophagy was reversed by 740 Y-P, the activator of PI3K/AKT signal pathway. The in vivo experiments demonstrated that ropivacaine inhibited the proliferation and mobility of BC. Ropivacaine has anti-carcinoma effects in BC via inactivating PI3K/AKT pathway, providing a new theoretical reference for the use of local anesthetics in the treatment of BC.