BACKGROUND: Long noncoding RNAs (lncRNAs) play pivotal roles in various malignant tumors. Epidermal growth factor receptor (EGFR) signaling is associated with the pathogenesis of cutaneous squamous cell carcinoma (cSCC). This study aimed to explore the role of LINC00520 in the development of cSCC via EGFR and phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) signaling pathways. METHODS: A microarray analysis was applied to screen differentially expressed lncRNAs in cSCC samples. The A431 cSCC cell line was transfected and assigned different groups. The expression patterns of LINC00520, EGFR, and intermediates in the PI3K/Akt pathway were characterized using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis. Cell proliferation, migration, and invasion were detected using the MTT assay, scratch test, and Transwell assay, respectively. Cell-based experiments and a tumorigenicity assay were conducted to assess the effect of LINC00520 on cSCC progression. This study was ended in September 2017. Comparisons between two groups were analyzed with t-test and comparisons among multiple groups were analyzed using one-way analysis of variance. The nonparametric Wilcoxon rank sum test was used to analyze skewed data. The enumerated data were analyzed using the chi-square test or Fisher exact test. RESULTS: Data from chip GSE66359 revealed depletion of LINC00520 in cSCC. Cells transfected with LINC00520 vector and LINC00520 vector + si-EGFR showed elevated LINC00520 level but decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the si-LINC00520 group showed opposite trends (all P < 0.05). Compared with the LINC00520 vector group, the LINC00520 vector + si-EGFR group showed decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the LINC00520 vector + EGFR vector group showed opposite results (all P < 0.05). CONCLUSION Based on our results, LINC00520-targeted EGFR inhibition might result in the inactivation of the PI3K/Akt pathway, thus inhibiting cSCC development.
Animals ; Carcinoma, Squamous Cell ; pathology ; prevention & control ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Disease Progression ; ErbB Receptors ; antagonists & inhibitors ; Female ; Humans ; Lymphatic Metastasis ; Mice ; Neoplasm Invasiveness ; Phosphatidylinositol 3-Kinases ; physiology ; Proto-Oncogene Proteins c-akt ; physiology ; RNA, Long Noncoding ; physiology ; Signal Transduction ; physiology ; Skin Neoplasms ; pathology ; prevention & control

Advanced prostate cancer, especially at the castration-resistant stage, remains incurable clinically and, therefore, urgently requires new therapeutics for the patients. PI3K is a family of critical cell signal transduction molecules and their over-activation is an important factor in cancer development and progression. It has been demonstrated that class IA PI3K p110 is drastically overexpressed in prostate cancer and involved in androgen receptor-mediated gene expression and castration-resistant progression and regarded as a potential therapeutic target for prostate cancer. Several p110-specific inhibitors have been reported recently and two of them, GSK2636771 and AZD8186, are being tested in clinical trials.
Aniline Compounds ; therapeutic use ; Chromones ; therapeutic use ; Humans ; Imidazoles ; therapeutic use ; Male ; Morpholines ; therapeutic use ; Neoplasm Proteins ; antagonists & inhibitors ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphoinositide-3 Kinase Inhibitors ; Prostatic Neoplasms, Castration-Resistant ; drug therapy ; enzymology ; Protein Kinase Inhibitors ; therapeutic use

β3-adrenoceptor (β3-AR) has been shown to promote myocardial apoptosis. However, the exact physiological role and importance of this receptor in the human myocardium, and its underlying mode of action, have not been fully elucidated. The present study aimed to determine the effects of β3-AR on the promotion of myocardial apoptosis and on norepinephrine (NE) injury. We analyzed NE-induced cardiomyocyte (CM) apoptosis by using a TUNEL and an annexin V/propidium iodide apoptosis assay. Furthermore, we investigated the NE-induced expression of the apoptosis marker genes Akt and p38MAPK, their phosphorylated counterparts p-Akt and p-p38MAPK, caspase-3, Bcl-2, and Bax. In addition, we determined the effect of a 48-h treatment with a β3-AR agonist and antagonist on expression of these marker genes. β3-AR overexpression was found to increase CM apoptosis, accompanied by an increased expression of caspase-3, bax/bcl-2, and p-p38MAPK. In contrast, the β3-blocker reduced apoptosis of CMs and the associated elevated Akt expression. We identified a novel and potent anti-apoptosis mechanism via the PI3K/Akt pathway and a pro-apoptosis pathway mediated by p38MAPK.
Adrenergic Agonists ; pharmacology ; Adrenergic Antagonists ; pharmacology ; Animals ; Apoptosis ; Cells, Cultured ; Myocytes, Cardiac ; drug effects ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, beta-3 ; genetics ; metabolism ; Signal Transduction ; p38 Mitogen-Activated Protein Kinases ; metabolism

Cancer stem cells (CSCs) have tumor initiation, self-renewal, metastasis and chemo-resistance properties in various tumors including colorectal cancer. Targeting of CSCs may be essential to prevent relapse of tumors after chemotherapy. Phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) signals are central regulators of cell growth, proliferation, differentiation, and apoptosis. These pathways are related to colorectal tumorigenesis. This study focused on PI3K and mTOR pathways by inhibition which initiate differentiation of SW620 derived CSCs and investigated its effect on tumor progression. By using rapamycin, LY294002, and NVP-BEZ235, respectively, PI3K and mTOR signals were blocked independently or dually in colorectal CSCs. Colorectal CSCs gained their differentiation property and lost their stemness properties most significantly in dual-blocked CSCs. After treated with anti-cancer drug (paclitaxel) on the differentiated CSCs cell viability, self-renewal ability and differentiation status were analyzed. As a result dual-blocking group has most enhanced sensitivity for anti-cancer drug. Xenograft tumorigenesis assay by using immunodeficiency mice also shows that dual-inhibited group more effectively increased drug sensitivity and suppressed tumor growth compared to single-inhibited groups. Therefore it could have potent anti-cancer effects that dual-blocking of PI3K and mTOR induces differentiation and improves chemotherapeutic effects on SW620 human colorectal CSCs.
AC133 Antigen/genetics/metabolism ; Animals ; Antineoplastic Agents/pharmacology/therapeutic use ; Cell Differentiation/*drug effects ; Cell Line, Tumor ; Cell Survival/drug effects ; Chromones/pharmacology/therapeutic use ; Colorectal Neoplasms/drug therapy/metabolism/pathology ; Humans ; Imidazoles/pharmacology/therapeutic use ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Morpholines/pharmacology/therapeutic use ; Neoplastic Stem Cells/cytology/drug effects/metabolism ; Paclitaxel/pharmacology/therapeutic use ; Phosphatidylinositol 3-Kinases/*antagonists & inhibitors/metabolism ; Quinolines/pharmacology/therapeutic use ; SOXB1 Transcription Factors/genetics/metabolism ; Signal Transduction/*drug effects ; Sirolimus/pharmacology/therapeutic use ; TOR Serine-Threonine Kinases/*antagonists & inhibitors/metabolism ; Xenograft Model Antitumor Assays

The phosphatidylinositol 3 kinase (PI3K) pathway is frequently altered in cancer, including ovarian cancer (OC). Unfortunately, despite a sound biological rationale and encouraging activity in preclinical models, trials of first-generation inhibitors of mammalian target of rapamycin (mTOR) in OC have demonstrated negative results. The lack of patient selection as well as resistance to selective mTOR complex-1 (mTORC1) inhibitors could explain the disappointing results thus far. Nonetheless, a number of novel agents are being investigated, including dual mTORC1/mTORC2, Akt, and PI3K inhibitors. Although it is likely that inhibition of the PI3K/Akt/mTOR pathway may have little effect in unselected OC patients, certain histological types, such as clear cell or endometrioid OC with frequent phosphatidylinositol-4,5-biphosphate 3-kinase, catalytic subunit alpha (PIK3CA) and/or phosphatase and tensin homolog (PTEN) alterations, may be particularly suited to this approach. Given the complexity and redundancy of the PI3K signaling network, PI3K pathway inhibition may be most useful in combination with either chemotherapy or other targeted therapies, such as MEK inhibitors, anti-angiogenic therapy, and hormonal therapy, in appropriately selected OC patients. Here, we discuss the relevance of the PI3K pathway in OC and provide an up-to-date review of clinical trials of novel PI3K inhibitors alone or in combination with cytotoxics and novel therapies in OC. In addition, the challenges of drug resistance and predictive biomarkers are addressed.
Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Drug Resistance, Neoplasm ; Female ; Humans ; Ovarian Neoplasms ; drug therapy ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; physiology ; Proto-Oncogene Proteins c-akt ; antagonists & inhibitors ; physiology ; Signal Transduction ; drug effects ; TOR Serine-Threonine Kinases ; antagonists & inhibitors ; physiology

OBJECTIVETo investigate the effect of CAL-101, a selective inhibitor of PI3Kδ, in combination with bortezomib on the proliferation and apoptosis in human mantle cell lymphoma cell lines Z138, HBL-2 and Jeko-1 in vitro, to explore its mechanisms and provide the foundation for effective treatment strategies against mantle cell lymphoma.

METHODSMTT assay was applied to detect the inhibitory effects of CAL-101 and bortezomib either alone or combined on Z138, HBL-2 and Jeko-1 cells. Calcusyn software was used to analyze the synergistic cytotoxicity. Western blot was used to detect the expression of PI3K-p110σ and p-Akt, Akt, p-ERK and ERK proteins after the cells were exposed to different concentrations of CAL-101. Flow cytometry was employed to assess the apoptosis rate. NF-κB kit was used to determine the changes of location of NF-κB P65, and Western blot was applied to detect the level of caswpase-3 and the phosphorylation of Akt in different groups.

RESULTSCAL-101 and BTZ inhibited the proliferation of Z138, HBL-2 and Jeko-1 cells in a dose- and time-dependent manner. CAL-101/BTZ combination induced significantly synergistic cytotoxicity in the MCL cells. The results of Western blot assay showed that CAL-101 significantly blocked the phosphorylation of Akt and ERK in the MCL cell lines. In addition, CAL-101 combined with BTZ induced pronounced apoptosis (P < 0.01). For example, after the Z138 cells exposed to the drugs for 48 h, the apoptosis rates of the control, CAL-101, BTZ and CAL-101 + BTZ groups were: (2.6 ± 1.8)%, (40.0 ± 3.0)%, (34.0 ± 1.0)%, and (67.4 ± 1.0)%, respectively; and when drug treatment was given to HBL-2 cells over 96 h, the apoptosis rates of these four cell groups were (7.4 ± 0.6)%, (30.7 ± 5.7)%, (12.0 ± 1.0)%, and (85.0 ± 4.0)%, respectively. The combination therapy contributed to the enhanced inactivity of nuclear factor-κB (NF-κB) and Akt inactivation in the MCL cell lines (P < 0.05), however, the casepase-3 activity was up-regulated.

CONCLUSIONSThe combination of CAL-101 and bortezomib is muchmore effective in inhibiting proliferation and promoting apoptosis of mantle cell lymphoma cell lines (Z138, HBL-2 and Jeko-1), which may be mediated through inhibiting PI3K/Akt signaling pathway and the transcription of NF-κB.

Antineoplastic Agents ; pharmacology ; Antineoplastic Combined Chemotherapy Protocols ; pharmacology ; Apoptosis ; drug effects ; Blotting, Western ; Boronic Acids ; Bortezomib ; pharmacology ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Class Ia Phosphatidylinositol 3-Kinase ; antagonists & inhibitors ; Dose-Response Relationship, Drug ; Drug Synergism ; Formazans ; Humans ; Lymphoma, Mantle-Cell ; drug therapy ; pathology ; MAP Kinase Signaling System ; drug effects ; NF-kappa B ; metabolism ; Neoplasm Proteins ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Purines ; administration & dosage ; pharmacology ; Pyrazines ; Quinazolinones ; administration & dosage ; pharmacology ; Signal Transduction ; Software ; Tetrazolium Salts

To study the regulation of androgen receptor (AR) expression in human prostate cancer LNCaP cells by triptolide (TP) and the possible mechanism, by using qRT-PCR and Western blot, the AR mRNA and protein levels in TP treated LNCaP cells were detected, and the AR protein level in TP and NF-κB inhibitor treated LNCaP cells was also detected; a series of pGL3-AR promoter reporter gene vectors were built using restriction-free cloning method, and the vectors were employed to investigate the effects of TP on the transcriptional activity of AR promoter in LNCaP cells; the upstream proteins which may play regulatory roles were detected using western blot assay. After treated LNCaP cells with TP for 48 h, AR mRNA and protein expressions decreased with increasing TP concentration. The expression of AR target gene PART1 and prostate specific antigen (PSA) was also downregulated by TP treatment; a series of pGL3-AR promoter reporter vectors were constructed and validated by sequencing and luciferase activity; the results of dual luciferase reporter assay showed that TP downregulated AR at the transcriptional level; PI3K/AKT/NF-κB pathway which is associated with AR promoter activity was drowregulated by TP. In conclusion, our results demonstrated that the transcriptional activity of AR in LNCAP cells was downregulated by TP, and PI3K/AKT/NF-κB pathway may be involved in the regulation mechanism.
Cell Line, Tumor ; Diterpenes ; pharmacology ; Down-Regulation ; Epoxy Compounds ; pharmacology ; Genetic Vectors ; Humans ; Male ; NF-kappa B ; antagonists & inhibitors ; Phenanthrenes ; pharmacology ; Phosphatidylinositol 3-Kinases ; metabolism ; Promoter Regions, Genetic ; Prostate-Specific Antigen ; metabolism ; Prostatic Neoplasms ; metabolism ; RNA, Messenger ; Receptors, Androgen ; metabolism ; Signal Transduction ; Transcriptional Activation

Humans ; Leukemia ; drug therapy ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; Proto-Oncogene Proteins c-akt ; antagonists & inhibitors ; TOR Serine-Threonine Kinases ; antagonists & inhibitors

An F-box protein, beta-TrCP recognizes substrate proteins and destabilizes them through ubiquitin-dependent proteolysis. It regulates the stability of diverse proteins and functions as either a tumor suppressor or an oncogene. Although the regulation by beta-TrCP has been widely studied, the regulation of beta-TrCP itself is not well understood yet. In this study, we found that the level of beta-TrCP1 is downregulated by various protein kinase inhibitors in triple-negative breast cancer (TNBC) cells. A PI3K/mTOR inhibitor PI-103 reduced the level of beta-TrCP1 in a wide range of TNBC cells in a proteasome-dependent manner. Concomitantly, the levels of c-Myc and cyclin E were also downregulated by PI-103. PI-103 reduced the phosphorylation of beta-TrCP1 prior to its degradation. In addition, knockdown of beta-TrCP1 inhibited the proliferation of TNBC cells. We further identified that pharmacological inhibition of mTORC2 was sufficient to reduce the beta-TrCP1 and c-Myc levels. These results suggest that mTORC2 regulates the stability of beta-TrCP1 in TNBC cells and targeting beta-TrCP1 is a potential approach to treat human TNBC.
Cell Line, Tumor ; Cell Proliferation ; Cell Survival/drug effects ; Cyclin E/genetics/metabolism ; Dose-Response Relationship, Drug ; Female ; Furans/pharmacology ; Gene Knockdown Techniques ; Humans ; Models, Biological ; Multiprotein Complexes/antagonists & inhibitors ; Phosphatidylinositol 3-Kinases/*antagonists & inhibitors ; Phosphorylation/drug effects ; Protein Kinase Inhibitors/*pharmacology ; Proteolysis/drug effects ; Proto-Oncogene Proteins c-myc/genetics/metabolism ; Pyridines/pharmacology ; Pyrimidines/pharmacology ; TOR Serine-Threonine Kinases/*antagonists & inhibitors ; Triple Negative Breast Neoplasms/genetics/*metabolism ; beta-Transducin Repeat-Containing Proteins/genetics/*metabolism

PURPOSE: To investigate the effects of resveratrol on the expression of hypoxia-inducible factor 1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) in human adult retinal pigment epithelial (ARPE-19) cells, and on experimental choroidal neovascularization (CNV) in mice. MATERIALS AND METHODS: ARPE-19 cells were treated with different concentrations of resveratrol and then incubated under hypoxic conditions with subsequent evaluation of cell viability, expression of HIF-1alpha, and expression of VEGF. The effects of resveratrol on the synthesis and degradation of hypoxia-induced HIF-1alpha were evaluated using inhibitors of the PI3K/Akt/mTOR and the ubiquitin proteasome pathways. In animal studies, CNV lesions were induced in C57BL/6 mice by laser photocoagulation. After 7 days of oral administration of resveratrol or vehicle, which began one day after CNV induction, image analysis was used to measure CNV areas on choroidal flat mounts stained with isolectin IB4. RESULTS: In ARPE-19 cells, resveratrol significantly inhibited HIF-1alpha and VEGF in a dose-dependent manner, by blocking the PI3K/Akt/mTOR signaling pathway and by promoting proteasomal HIF-1alpha degradation. In mice experiments, orally administered resveratrol significantly inhibited CNV growth in a dose-dependent manner. CONCLUSION: Resveratrol may have therapeutic value in the management of diseases involving pathological neovascularization.
Adult ; Animals ; Anoxia/metabolism/physiopathology ; Cell Survival/drug effects ; Choroidal Neovascularization/*metabolism/pathology ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/*drug effects/metabolism ; Mice ; Mice, Inbred C57BL ; Phosphatidylinositol 3-Kinases/antagonists & inhibitors/*physiology ; Proteasome Endopeptidase Complex ; Proto-Oncogene Proteins c-akt/antagonists & inhibitors/*physiology ; Retinal Pigment Epithelium/*drug effects/metabolism ; Signal Transduction ; Stilbenes/administration & dosage/*pharmacology ; TOR Serine-Threonine Kinases/antagonists & inhibitors/*physiology ; Ubiquitin ; Vascular Endothelial Growth Factor A/*drug effects/metabolism