Silencing of Nek2 suppresses the proliferation,migration and invasion and induces apoptosis of breast cancer cells by regulating ERK/MAPK signaling

Journal of Molecular Histology - Breast cancer is a frequent cancer among women. The current study investigated the biological functions of Nek2 in breast cancer and its possible mechanism. The...     

MicroRNA-185 suppresses proliferation, invasion, migration, and tumorigenicity of human prostate cancer cells through targeting androgen receptor

Previous studies have shown that androgen receptor (AR) is involved in the progression of prostate cancer (CaP) by several mechanisms. However, how AR is regulated has not been fully understood. In this study, miR-185 was found to be down-regulated in clinical CaP samples. Targets prediction revealed that AR had putative complementary sequences to miR-185, which was confirmed by the following dual luciferase reporter assay. Overexpression of miR-185 could reduce the expression of AR protein but not mRNA in LNCaP cells. The proliferation of LNCaP cells was inhibited by overexpression of miR-185. Cell cycle analysis revealed cell cycle arrest at G0/G1 phase. The invasive and migration abilities of cells could also be suppressed by miR-185. Furthermore, miR-185 inhibited tumorigenicity in a CaP xenografts model. CDC6, one target of AR and an important regulatory molecule for cell cycle, was found to be down-regulated by overexpression of miR-185. Our findings suggest that miR-185 could function as a tumor-suppressor gene in CaP by directly targeting AR, and act as a potential therapeutic target for CaP.     

Crk II silencing down-regulates IGF-IR and inhibits migration and invasion of prostate cancer cells

Crk (C10 regulator of kinase) adaptor proteins are highly expressed in many types of human cancers and often contribute to aggressive cancer phenotypes. Crk II, a member of CRK family, has been reported to regulate cell migration and metastasis in breast cancer cells. However, its role in other cancer types has not been reported. In this study, we investigated the molecular function of Crk II in prostate cancer (PCa) cells (CWR-22rv1) in vitro and using a mouse tumor model. Results showed that Crk II knockdown by shRNA-mediated silencing (Crk II-shRNA) in the PCa cells significantly inhibited both cancer cell migration and invasion in cell culture study. Crk II-shRNA cancer cells also significantly decreased colony formation in vitro, but had no significant reduction of tumor volume after 4 weeks of cancer cell xenografting in vivo when compared to the scramble control. Interestingly, Crk II-shRNA cancer cells showed a greatly reduced level of insulin-like growth factor 1 receptor (IGF-1R) and decreased signaling of the IGF-1R/PI3K/Akt axis upon IGF-1 ligand stimulation. A close interaction between Crk II and IGF-1R was demonstrated upon co-immunoprecipitation of IGF-1R with Crk II protein. Further, treatment of cells with either proteosomal degradation or protein synthesis inhibitor showed higher proportion of ubiquitin-associated IGF-1R and faster degradation of IGF-1R in Crk II-shRNA cells in comparison with that in the control cancer cells. Taken together, these data suggest that Crk II plays an important role in the regulation of IGF-1R protein stability and affects downstream of IGF-1R signaling pathways. Therefore, targeting Crk-II can block IGF-1R growth signaling and suppress cancer cell invasion and progression.     

Benzyldihydroxyoctenone,a novel anticancer agent,induces apoptosis via mitochondrial-mediated pathway in androgen-sensitive LNCaP prostate cancer cells

This study was aimed to evaluate detailed mechanisms on the apoptotic induction of benzyldihydroxyoctenone, a novel compound isolated from Streptomyces sp. KACC91015, in androgen-sensitive LNCaP prostate cancer cells. Benzyldihydroxyoctenone, designated as F3-2-5 in the current study, caused accumulation of apoptotic sub-G₁ phase in the flow cytometric analysis using propidium iodide staining. Moreover, the typical apoptotic DNA fragmentation of the LNCaP cells treated with 30 μM of F3-2-5 was confirmed using the TUNEL assay. This apoptotic induction of F3-2-5 in the LNCaP cells was associated with the cytochrome c release from mitochondria to cytosol, and the activation of procaspase-8, -9, and -3, as well as the specific proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). In addition, F3-2-5 treatment caused the down-regulation of the antiapoptotic protein, such as Bcl-2 and Bcl-X_L, but the proapoptotic protein, such as Bax, was not influenced. To investigate whether apoptotic induction by F3-2-5 is also due to the down-regulation of androgen receptor (AR), Western blot analysis and quantitative RT-PCR were conducted in F3-2-5-treated LNCaP prostate cancer cells. We found that F3-2-5 significantly inhibited the expression levels of AR and prostate-specific antigen (PSA) proteins in a time-dependent manner, as well as F3-2-5 abrogated the up-regulation of AR and PSA genes with and without DHT. Therefore, F3-2-5 has been shown to be an androgen antagonist, suggesting that F3-2-5 could be a potent agent for the treatment of both androgen-dependent and hormone-refractory prostate cancer.     

Knockdown of TMPRSS3 inhibits cell proliferation,migration/invasion and induces apoptosis of glioma cells

Transmembrane protease serine 3 (TMPRSS3) is a member of type II transmembrane serine proteases (TTSP) family, which play important roles in the development and progression of various cancers. However, the role of TMPRSS3 in glioma remains unclear. In the present study, we evaluated the expression patterns of TMPRSS3 in clinical tumor samples and glioma cell lines. The results showed that TMPRSS3 was highly expressed in both human glioma tissues and cell lines. Knockdown of TMPRSS3 in glioma cells by transfection with small interfering RNA targeting TMPRSS3 (si-TMPRSS3) significantly suppressed cell proliferation and migration/invasion. Moreover, knockdown of TMPRSS3 markedly elevated the apoptotic rate of glioma cells. Si-TMPRSS3 transfection also resulted in a remarkable increase in bax expression and a notable decrease in bcl-2 expression in glioma cells. Furthermore, TMPRSS3 knockdown markedly suppressed the expressions of Notch1 and Hes1. The results indicated that knockdown of TMPRSS3 exhibited antiglioma effect, which is associated with the inactivation of the Notch signaling pathway. These findings suggested that TMPRSS3 might be used as a therapeutic target for glioma treatment.     

Overexpression LINC01082 suppresses the proliferation,migration and invasion of colon cancer

The active form of vitamin D, 1,25-dihydroxycholecalciferol (1,25(OH)₂D₃), was reported to improve vascular function in patients with diabetes, yet the underlying mechanisms remain to be fully elucidated. Monoamine oxidase (MAO), a mitochondrial enzyme, with two isoforms (A and B) that generates hydrogen peroxide (H₂O₂) as by-product, has been recently reported to contribute to the pathogenesis of endothelial dysfunction in diabetes. The present study assessed the interaction between vitamin D and MAO in the vascular wall in the setting of type 1 experimental diabetes. To this aim, diabetes was induced in male Wistar rats via a single injection of streptozotocin (STZ, 50 mg/kg, IP) and 1 month later thoracic aortas were harvested and used for organ bath studies and H₂O₂ measurements. MAO expression was assessed by immunohistochemistry and RT-PCR. Endothelial function was evaluated in isolated aortic rings in the absence vs. presence of 1,25(OH)₂D₃ (100 nM, 24 h incubation). In diabetic animals, we found a significant reduction in the endothelial-dependent relaxation to acetylcholine and an increased expression of the MAO-A isoform, respectively. Vitamin D significantly improved vascular function, mitigated oxidative stress and decreased MAO-A expression in diabetic vascular preparations. In conclusion, MAO-A is induced in diabetic aortas and vitamin D can improve diabetes-induced endothelial dysfunction by modulating the MAO-A expression.

     

MicroRNA-335 suppresses the proliferation,migration, and invasion of breast cancer cells by targeting EphA4

MicroRNAs (miRNAs) are small noncoding RNAs that exert their functions by targeting specific mRNA sequences. Many studies have demonstrated that miRNAs are crucial for cancer progression, during which they can act as either oncogenes or tumor suppressors. Previous research has shown that miR-335 is downregulated in breast cancer, and it has been shown to be a breast cancer suppressor. In addition, emerging evidence indicates that erythropoietin-producing hepatocellular A4 (EphA4) is implicated in cancer cell proliferation, migration, and invasion. However, little is known about the relationship between miR-335 and EphA4 in breast cancer. In the present study, we used bioinformatic and biochemical analyses to demonstrate that EphA4 is a direct downstream target of miR-335 in human breast cancer MCF-7 and MDA-MB-23 cells and revealed that miR-335 negatively regulates the expression of EphA4 in these cells. Further investigation revealed that miR-335 overexpression inhibits MCF-7 and MDA-MB-231 cell proliferation and that this inhibition is attenuated by EphA4 coexpression. Similarly, miR-335 overexpression also inhibited growth and downregulated EphA4 expression in tumors in nude mice. Moreover, our results demonstrated that miR-335 overexpression suppresses migration and invasion in MCF-7 and MDA-MB-231 cells, an effect that was reversed by EphA4 overexpression. These findings confirmed that EphA4 is a direct target gene of miR-335 and that miR-335 suppresses breast cancer cell proliferation and motility in part by directly inhibiting EphA4 expression.     

TMEM106A inhibits cell proliferation,migration, and induces apoptosis of lung cancer cells

Transmembrane protein 106A (TMEM106A) has been found to function as tumor suppressor in gastric and renal cancer. However, the role of TMEM106A in nonsmall-cell lung carcinoma (NSCLC) has not been investigated. In this study, we evaluated the expression profile of TMEM106A in NSCLC tissues and cell line, and explored the roles of TMEM106A in NSCLC cell lines. Our results showed that TMEM106A expression was significantly decreased in human NSCLC tissues. In vitro assays showed that TMEM106A expression in NSCLC cell lines was much lower than that in the bronchial epithelial cell line. Besides, overexpression of TMEM106A reduced cell proliferation, migration, and invasion, while induced cell apoptosis in NSCLC cells. TMEM106A overexpression repressed epithelial-mesenchymal transition (EMT), which was illustrated by increased E-cadherin expression and decreased the expressions of N-cadherin, and vimentin. In addition, TMEM106A overexpression suppressed the activation of phosphoinositide 3-kinase/protein kinase B/nuclear factor-κB (PI3K/Akt/NF-κB) signaling pathway in NSCLC cells. Our results indicated that TMEM106A acted as a tumor suppressor in NSCLC, and could be a therapeutic target for the management of NSCLC.     

Effects of tomato paste extracts on cell proliferation, cell-cycle arrest and apoptosis in LNCaP human prostate cancer cells

Since tomato consumption is associated with decreased risk of prostate cancer, cell proliferation, cell cycle progression and apoptosis by LNCaP human prostate cancer cells might elucidate action of tomatoes. To discover possible bioactive fractions of tomatoes, whole tomato paste and its water and hexane extract were used and biomarkers of carcinogenesis were measured. After 6, 24 and 48 hr of incubation, cells were harvested and determined cell growth. Tomato paste hexane extract inhibited cell proliferation by 33% compared to the control after 48 hr incubation. Whole tomato paste and its water extract showed only modest growth inhibition. Tomato paste hexane extract at 5 microM lycopene increased G2/M-phase of the cell cycle from 13 to 28% and decreased S-phase cells from 45 to 29%. Apoptosis was observed at the 5 microM hexane extract at the late stages during 24 and 48 hr treatment. Tomato, therefore, deserves study as a potential chemopreventive/chemotherapeutic agent.     

CFTR activation suppresses glioblastoma cell proliferation,migration and invasion

The aim of this study was to investigate the function of Cystic fibrosis transmembrane conductance regulator (CFTR) in human glioblastoma (GBM) cells. Data dining results of the Human Protein Atlas showed that low CFTR expression was associated with poor prognosis for GBM patients. We found that CFTR protein expression was lower in U87 and U251 GBM cells than that in normal humane astrocyte cells. CFTR activation significantly reduced GBM cell proliferation. In addition, CFTR activation significantly abrogated migration and invasion of GBM cells. Besides, CFTR activator Forskolin treatment markedly reduced MMP-2 protein expression. These effects of CFTR activation were significantly inhibited by CFTR inhibitor CFTRinh-172 pretreatment. Our findings suggested that JAK2/STAT3 signaling was involved in the anti-glioblastoma effects of CFTR activation. Moreover, CFTR overexpression in combination with Forskolin induced a synergistic anti-proliferative response in U87?cells. Overall, our findings demonstrated that CFTR activation suppressed GBM cell proliferation, migration and invasion likely through the inhibition of JAK2/STAT3 signaling.     

Characterization of calcium release-activated apoptosis of LNCaP prostate cancer cells

Apoptosis inhibition rather than enhanced cellular proliferation occurs in prostate cancer (CaP), the most commonly diagnosed malignancy in American men. Therefore, it is important to characterize residual apoptotic pathways in CaP cells. When intracellular Ca(2+) stores are released and plasma membrane "store-operated" Ca(2+) entry channels subsequently open, cytosolic [Ca(2+)] increases and is thought to induce apoptosis. However, cells incapable of releasing Ca(2+) stores are resistant to apoptotic stimuli, indicating that Ca(2+) store release is also important. We investigated whether release of intracellular Ca(2+) stores is sufficient to induce apoptosis of the CaP cell line LNCaP. We developed a method to release stored Ca(2+) without elevating cytosolic [Ca(2+)]; this stimulus induced LNCaP cell apoptosis. We compared the apoptotic pathways activated by intracellular Ca(2+) store release with the dual insults of store release and cytosolic [Ca(2+)] elevation. Earlier processing of caspases-3 and -7 occurred when intracellular store release was the sole Ca(2+) perturbation. Apoptosis was attenuated in both conditions in stable transfected cells expressing antiapoptotic proteins Bclx(L) and catalytically inactive caspase-9, and in both scenarios inactive caspase-9 became complexed with caspase-7. Thus, intracellular Ca(2+) store release initiates an apoptotic pathway similar to that elicited by the dual stimuli of cytosolic [Ca(2+)] elevation and intracellular store release.     

Naringenin inhibits migration,invasion, induces apoptosis in human lung cancer cells and arrests tumour progression in vitro

Lung cancer is one of the major cause for high-death rate all over the world, due to increased metastasize and difficulties in diagnosis. Naringenin is naturally occurring flavonoid found in various fruits including tomatoes, citrus fruit and figs. Naringenin is known to have several therapeutic effects including anti-atherogenic, antimicrobial, anti-inflammatory, hepatoprotective, anticancer and anti-mutagenic. The present study was aimed to analyse the naringenin induced anti-proliferative and apoptosis effects in human lung cancer cells. Cells were treated with various concentrations of naringenin (10, 100 & 200 µmol/L) for 48 hours. Cisplatin (20 µg/mL) was used as positive control. Cell viability, apoptosis, migration and mRNA, and protein expression of caspase-3, matrixmetallo proteinases-2 (MMP-2) and MMP-9 were determined. The cell viability was 93.7 ± 7.5, 51.4 ± 4.4 and 32.1 ± 2.1 at 10, 100 and 200 µmol/L of naringenin respectively. Naringenin significantly increased apoptotic cells. The 100 and 200 µmol/L of naringenin significantly suppressed the larger wounds of cultured human cancer cells compared with the untreated lung cancer cells. Naringenin increased d the expression of caspase-3 and reduced the expression of MMP-2 and MMP-9. Taking all these data together, it is suggested that the naringenin was effective against human lung cancer proliferation, migration and metastasis.     

7,8-Dihydroxyflavone suppresses proliferation and induces apoptosis of human osteosarcoma cells

Recent studies suggest that 7,8-dihydroxyflavone (7,8-DHF) inhibits the development of several tumors.However,its role in osteosarcoma (OS) remains unknown.This...     

Juglone,isolated from Juglans mandshurica Maxim,induces apoptosis via down-regulation of AR expression in human prostate cancer LNCaP cells

Juglone is a natural compound which has been isolated from Juglans mandshurica Maxim. Recent studies have shown that juglone had various pharmacological effects such as anti-viral, anti-bacterial and anti-cancer. However, its anti-cancer activity on human prostate cancer LNCaP cell has not been examined. Thus, the current study was designed to elucidate the molecular mechanism of apoptosis induced by juglone in androgen-sensitive prostate cancer LNCaP cells. MTT assay was performed to examine the anti-proliferative effect of juglone. Occurrence of apoptosis was detected by Hoechst 33342 staining and flow cytometry in LNCaP cells treated with juglone for 24 h. The result shown that juglone inhibited the growth of LNCaP cells in a dose-dependent manner. Morphological changes of apoptotic body formation after juglone treatment were observed by Hoechst 33342 staining. This apoptotic induction was associated with loss of mitochondrial membrane potential, and caspase-3, -9 activation. Moreover, we found that juglone significantly inhibited the expression levels of androgen receptor (AR) and prostate-specific antigen (PSA) in a dose-dependent manner, as well as abrogated up-regulation of AR and PSA genes with and/or without dihydrotestosterone (DHT). Take together, our results demonstrated that juglone might induce the apoptosis in LNCaP cell via down-regulation of AR expression. Therefore, our results indicated that juglone may be a potential candidate of drug for androgen-sensitive prostate cancer.     

Harmine induces apoptosis and inhibits tumor cell proliferation,migration and invasion through down-regulation of cyclooxygenase-2 expression in gastric cancer

Cyclooxygenase-2 (COX-2) plays an important role in the carcinogenesis and progression of gastric cancer. Harmine is reported as a promising drug candidate for cancer therapy; however, effects and action mechanism of harmine on the human gastric cancer cells remain unclear. This study evaluated the anti-tumor effects of harmine on human gastric cancer both in vitro and in vivo. The cell proliferation was determined using MTT colorimetric assay. Apoptosis was measured by DAPI staining and flow cytometry analysis. The wound healing and transwell invasion assays were performed to evaluate the effects of harmine on the migration and invasion of gastric cancer cells. The expression of COX-2, proliferating cell nuclear antigen (PCNA), Bcl-2, Bax and matrix metalloproteinase-2 (MMP-2) was detected by Western blot analysis. Our results showed that harmine significantly inhibited cellular proliferation, migration, invasion and induced apoptosis in vitro, as well as inhibited tumor growth in vivo. In addition, harmine significantly inhibited the expression of COX-2, PCNA, Bcl-2 and MMP-2 as well as increased Bax expression in gastric cancer cells. These results collectively indicate that harmine induces apoptosis and inhibits proliferation, migration and invasion of human gastric cancer cells, which may be mediated by down-regulation of COX-2 expression.