NVP-BEZ235, a dual PI3K/mTOR inhibitor synergistically potentiates the antitumor effects of cisplatin in bladder cancer cells

Prognostic analysis of anoikis-related genes in bladder cancer: An observational study

Anoikis is proved to play a crucial role in the development of cancers. However, the impact of anoikis on the prognosis of bladder cancer (BLCA) is currently unknown. Thus, this study aimed to find potential effect of anoikis in BLCA. The Cancer Genome Atlas (TCGA)-BLCA and GSE13507 cohorts were downloaded from TCGA and the Gene Expression Omnibus (GEO) databases, respectively. Differentially expressed genes (DEGs) were screened between BLCA and normal groups, which intersected with anoikis-related genes to yield anoikis-related DEGs (AR DEGs). Univariate COX, rbsurv, and multivariate COX analyses were adopted in order to build a prognostic risk model. The differences of risk score in the different clinical subgroups and the relevance between survival rate and clinical characteristics were explored as well. Finally, chemotherapy drug sensitivity in different risk groups was analyzed. In total, 78 AR DEGs were acquired and a prognostic signature was build based on the 6 characteristic genes (CALR, FASN, CSPG4, HGF, INHBB, SATB1), where the patients of low-risk group had longer survival time. The survival rate of BLCA patients was significantly differential in different groups of age, stage, smoking history, pathologic-T, and pathologic-N. The IC50 of 56 drugs showed significant differences between 2 risk groups, such as imatinib, docetaxel, and dasatinib. At last, the results of real time quantitative-polymerase chain reaction (RT-qPCR) demonstrated that the expression trend of CALR, HGF, and INHBB was consistent with the result obtained previously based on public databases. Taken together, this study identified 6 anoikis-related characteristic genes (CALR, FASN, CSPG4, HGF, INHBB, SATB1) for the prognosis of BLCA patients, providing a scientific reference for further research on BLCA.

Landscape of targeted therapies for advanced urothelial carcinoma

Bladder cancer (BC) is the tenth most common malignancy globally. Urothelial carcinoma (UC) is a major type of BC, and advanced UC (aUC) is associated with poor clinical outcomes and limited survival rates. Current options for aUC treatment mainly include chemotherapy and immunotherapy. These options have moderate efficacy and modest impact on overall survival and thus highlight the need for novel therapeutic approaches. aUC patients harbor a high tumor mutation burden and abundant molecular alterations, which are the basis for targeted therapies. Erdafitinib is currently the only Food and Drug Administration (FDA)-approved targeted therapy for aUC. Many potential targeted therapeutics aiming at other molecular alterations are under investigation. This review summarizes the current understanding of molecular alterations associated with aUC targeted therapy. It also comprehensively discusses the related interventions for treatment in clinical research and the potential of using novel targeted drugs in combination therapy.

Mechanism of anticancer effect of ETP-45658, a PI3K/AKT/mTOR pathway inhibitor on HT-29 Cells

The PI3K pathway plays a crucial role in tumor cell proliferation across various cancers, including colon cancer, making it a promising treatment target. This study aims to investigate the antiproliferative activity of ETP-45658, a PI3K/AKT/mTOR pathway inhibitor, on colon cancer and elucidate the underlying mechanisms. HT-29 colon cancer cells were treated with varying doses of ETP 45658 and its cytotoxic effect assessed using the XTT cell viability assay.ELISA was also used to measure TAS, TOS, Bax, BCL-2, cleaved caspase 3, cleaved PARP, and 8-oxo-dG levels. Flow cytometry was performed to investigate apoptosis, cell cycle, caspase 3/7 activity, and mitochondrial membrane potential. Additionally, following the administration of DAPI (4,6-diamidino-2-phenylindole) dye, the cells were visualized using an immunofluorescence microscope. It was observed that ETP-45658 exerted a dose-dependent and statistically significant antiproliferative effect on HT-29 colon cancer cells. Further investigations using the IC50 dose showed that ETP-45658 decreased TAS levels and increased TOS levels and revealed that it upregulated apoptotic proteins while downregulating anti-apoptotic proteins. Our findings also showed that it increased Annexin V binding, arrested the cell cycle at G0/G1 phase, induced caspase 3/7 activity, impaired mitochondrial membrane potential, and ultimately triggered apoptosis in HT-29 cells. ETP-45658 shows promise against colon cancer by inducing cell death, and oxidative stress, and arresting the cell cycle. Targeting the PI3K/AKT/mTOR pathway with ETP-45658 offers exciting potential for colon cancer treatment.

Anti-tumor effect of AZD8055 against bladder cancer and bladder cancer-associated macrophages

The increased activity of the mTOR pathway in bladder cancer has been extensively studied, but no satisfactory mTOR inhibitor has been found in bladder cancer. The role of AZD8055, a second-generation mTOR inhibitor, has not been reported in bladder cancer. Herein, we investigated the effects of AZD8055 on bladder cells and their interaction with macrophages in vivo and in vitro. In four bladder cancer cell lines, the phosphorylation of mTOR, AKT and S6K1 was suppressed by AZD8055. AZD8055 inhibited proliferation and induced G1 cell-cycle arrest and apoptosis of bladder cancer cells in a concentration-dependent manner. AZD8055 also inhibits the migration and invasion of bladder cancer cells by blocking EMT and MMP9. In addition, AZD8055 inhibited chemotaxis and M2 phenotype of macrophage after co-culture with bladder cancer cells. These anti-tumor effects of AZD8055 were verified in vivo. Our findings collectively demonstrated that low-dose AZD8055 induces cytotoxicity and apoptosis, and inhibits the Akt/mTOR activation, invasion and migration of bladder cancer. These findings also demonstrate that AZD8055 partially blocked the interactions of bladder cancer cells and macrophages. In conclusion, AZD8055 is a promising mTOR inhibitor for bladder cancer.

Emerging Roles for Mammalian Target of Rapamycin (mTOR) Complexes in Bladder Cancer Progression and Therapy

The mammalian target of rapamycin (mTOR) pathway regulates important cellular functions. Aberrant activation of this pathway, either through upstream activation by growth factors, loss of inhibitory controls, or molecular alterations, can enhance cancer growth and progression. Bladder cancer shows high levels of mTOR activity in approximately 70% of urothelial carcinomas, suggesting a key role for this pathway in this cancer. mTOR signaling initiates through upstream activation of phosphatidylinositol 3 kinase (PI3K) and protein kinase B (AKT) and results in activation of either mTOR complex 1 (mTORC1) or mTOR complex 2 (mTORC2). While these complexes share several key protein components, unique differences in their complex composition dramatically alter the function and downstream cellular targets of mTOR activity. While significant work has gone into analysis of molecular alterations of the mTOR pathway in bladder cancer, this has not yielded significant benefit in mTOR-targeted therapy approaches in urothelial carcinoma to date. New discoveries regarding signaling convergence onto mTOR complexes in bladder cancer could yield unique insights the biology and targeting of this aggressive disease. In this review, we highlight the functional significance of mTOR signaling in urothelial carcinoma and its potential impact on future therapy implications.

Recent Advances in the Development of Noble Metal NPs for Cancer Therapy

With the development of nanotechnology, noble metal nanoparticles are widely used in the treatment of cancer due to their unique optical properties, excellent biocompatibility, surface effects, and small size effects. In recent years, researchers have designed and synthesized a large number of nanomedicines that can be used for cancer treatment based on the morphology, physical and chemical properties, mechanism of action, and toxicological studies of noble metal nanoparticles. Furthermore, the integration of diagnosis and treatment, hyperthermia, cytotoxicity research, and drug delivery system based on the study of noble metal nanoparticles can be used as effective means for cancer treatment. This article focuses on the analysis of noble metal nanoparticles that are widely used in the treatment of cancer, such as gold nanoparticles, silver nanoparticles, platinum nanoparticles, and palladium nanoparticles. The various methods and mechanisms of action of noble metal nanoparticles in the treatment of cancer are objectively summarized in detail. Based on the research on the therapeutic safety and toxicity of noble metal nanoparticles, the development prospect of noble metal nanoparticles in the future clinical application is prospected.

The Anti-Proliferative Effect of PI3K/mTOR and ERK Inhibition in Monolayer and Three-Dimensional Ovarian Cancer Cell Models

Simple Summary

In ovarian cancer patients the PI3K/AKT/mTOR and RAS/RAF/MEK/ERK kinase signaling pathways are frequently dysregulated, making them potential targets of therapeutic inhibitors. In this study, we used four human ovarian cancer cell lines grown in two- and three-dimensional models to investigate the potential efficacy of combining two inhibitors, which target these pathways, against ovarian cancer. The inhibitor combination was found to have cell line- and model-dependent synergistic antiproliferative effect.

Abstract

Most ovarian cancer patients are diagnosed with advanced stage disease, which becomes unresponsive to chemotherapeutic treatments. The PI3K/AKT/mTOR and the RAS/RAF/MEK/ERK kinase signaling pathways are attractive targets for potential therapeutic inhibitors, due to the high frequency of mutations to PTEN, PIK3CA, KRAS and BRAF in several ovarian cancer subtypes. However, monotherapies targeting one of these pathways have shown modest effects in clinical trials. This limited efficacy of the agents could be due to upregulation and increased signaling via the adjacent alternative pathway. In this study, the efficacy of combined PI3K/mTOR (BEZ235) and ERK inhibition (SCH772984) was investigated in four human ovarian cancer cell lines, grown as monolayer and three-dimensional cell aggregates. The inhibitor combination reduced cellular proliferation in a synergistic manner in OV-90 and OVCAR8 monolayers and in OV-90, OVCAR5 and SKOV3 aggregates. Sensitivity to the inhibitors was reduced in three-dimensional cell aggregates in comparison to monolayers. OV-90 cells cultured in large spheroids were sensitive to the inhibitors and displayed a robust synergistic antiproliferative response to the inhibitor combination. In contrast, OVCAR8 spheroids were resistant to the inhibitors. These findings suggest that combined PI3K/mTOR and ERK inhibition could be a useful strategy for overcoming treatment resistance in ovarian cancer and warrants further preclinical investigation. Additionally, in some cell lines the use of different three-dimensional models can influence cell line sensitivity to PI3K/mTOR and RAS/RAF/MEK/ERK pathway inhibitors.

Autophagy Modulation and Cancer Combination Therapy: A Smart Approach in Cancer Therapy

The autophagy pathway is the process whereby cells keep cellular homeostasis and respond to stress via recycling their damaged cellular proteins, organelles, and other cellular components. In the context of cancer, autophagy is a dual-edge sword pro- and anti-tumorigenic role depending on the oncogenic context and stage of tumorigenesis. Cancer cells have a higher dependency on autophagy compared with normal cells because of cellular damages and high demands for energy. The carbon, nitrogen, and molecular oxygen are building blocks for highly proliferative cancer cells which extremely depend on glutaminolysis and aerobic glycolysis; when a cancer cell is restricted to glucose and glutamine, it initiates to activate a stress response pathway using autophagy. Oncogenic tyrosine kinases (OncTKs) and receptor tyrosine kinases (RTKs) activation result in autophagy modulation through activation of the PI3K/AKT/mTORC1 and RAS/MAPK signaling pathways. Targeted inhibition of tyrosine kinases (TKs) and RTKs have recently been considered as cancer therapy but drug resistance and cancer relapse continue to be a major limitation of tyrosine kinase inhibitors (TKIs). Manipulation of autophagy pathway along with TKIs may be a promising strategy to circumvent unknown existing drug-resistance mechanisms that may emerge in a treated patient. In this way, clinical trials are ongoing to modulate autophagy to treat cancer. This review aims to summarize the combination therapy of autophagy affecting compounds with anticancer drugs which target cell signaling pathways, metabolism mechanisms, and epigenetics modification to improve therapeutic efficacy against cancers.

Antitumor Activity of Nanoparticles Loaded with PHT-427, a Novel AKT/PDK1 Inhibitor, for the Treatment of Head and Neck Squamous Cell Carcinoma

Currently, new treatments are required to supplement the current standard of care for head and neck squamous cell carcinoma (HNSCC). The phosphatidylinositol3-kinase (PI3K) signaling pathway is commonly altered and activated in HNSCC. PHT-427 is a dual PI3K-mammalian target of the AKT/PDK1 inhibitor; however, to the best of our knowledge, the effect of the PHT-427 inhibitor on HNSCC has not been investigated. This study aims to evaluate the antitumoral effect of PHT-427-loaded polymeric nanoparticles based on α-tocopheryl succinate (α-TOS). The in vitro activity of PHT-427 was tested in hypopharynx carcinoma squamous cells (FaDu) to measure the cell viability, PI3KCA/AKT/PDK1 gene expression, and PI3KCA/AKT/PDK1 levels. Apoptosis, epidermal growth factor receptor (EGFR), and reactive oxygen species (ROS) were also measured. The presence of PHT-427 significantly enhances its antiproliferative and proapoptotic activity by inactivating the PI3K/AKT/PDK1 pathway. Nanoparticles (NPs) effectively suppress AKT/PDK1 expression. Additionally, NPs loaded with PHT-427 produce high oxidative stress levels that induce apoptosis. In conclusion, these results are promising in the use of this nanoformulation as a PHT-427 delivery system for effective HNSCC treatment.

Quinoline-based Compounds with Potential Activity against Drugresistant Cancers

Drug resistance is the major cause of the failure of cancer chemotherapy, so one of the most important features in developing effective cancer therapeutic strategies is to overcome drug resistance. Quinoline moiety has become one of the most privileged structural motifs in anticancer agent discovery since its derivatives possess potent activity against various cancers including drug-resistant cancers. Several quinoline-based compounds which are represented by Anlotinib, Bosutinib, Lenvatinib, and Neratinib have already been applied in clinical practice to fight against cancers, so quinoline-based compounds are potential anticancer agents. The present short review article provides an overview of the recent advances of quinoline-based compounds with potential activity against drug-resistant cancers. The structure-activity relationship and mechanisms of action are also discussed.

Enhanced Sensitivity to NVP-BEZ235 by Inhibition of p62/SQSTM1 in Human Bladder Cancer KoTCC-1 Cells Both In Vitro and In Vivo

BACKGROUND/AIM

The prognosis of patients with invasive bladder cancer remains poor. The objective of this study was to evaluate the efficacy of NVP-BEZ235 (NVP), a dual PI3K/mTOR inhibitor, combined with the inactivation of p62/SQSTM1 (p62) in a human bladder cancer KoTCC-1 model.

MATERIALS AND METHODS

An expression plasmid with short hairpin RNA targeted against p62 was transfected into KoTCC-1 cells (KoTCC-1/sh-p62). The antitumor effects of NVP on KoTCC-1/sh-p62 were investigated in comparison with those on KoTCC-1 transfected with a control plasmid alone (KoTCC-1/C).

RESULTS

KoTCC-1/sh-p62 showed significantly higher sensitivity to NVP than KoTCC-1/C. Treatment of both cell lines with NVP markedly inactivated the PI3K/Akt/mTOR signaling pathway. However, NVP treatment stimulated the autophagic pathway in KoTCC-1/C, but not in KoTCC-1/sh-p62. Furthermore, compared with KoTCC-1/C, NVP treatment induced apoptosis of KoTCC-1/sh-p62 cells, which was accompanied by significant downregulation of c-IAP-1 and XIAP as well as upregulation of Bax. Moreover, the in vivo growth of KoTCC-1/sh-p62 tumors was significantly suppressed by treatment with NVP compared to KoTCC-1/C tumors.

CONCLUSION

Inhibition of p62 expression combined with NVP may represent an effective therapeutic approach for patients with invasive bladder cancer.

Novel Combination Therapies for the Treatment of Bladder Cancer

Bladder cancer is the ninth most frequently diagnosed cancer world-wide and ranks 13th in cancer-related deaths. Two tremendous breakthroughs in bladder cancer therapy over the last decades are the approval of immune checkpoint inhibitors(ICIs)and the fibroblast growth factor receptor tyrosine kinase inhibitor (FGFR-TKI) erdafitinib for treating this deadly disease. Despite the beneficial effects of these approaches, the low response rate and the potential resistance of the cancer are major concerns. Hence, novel combination therapies to overcome these limitations have been investigated. In this context, combining immunotherapy with targeted drugs is an appealing therapeutic option to improve response and reduce the emergence of resistance in the management of bladder cancer. In this review, the rationale of using different therapeutic combinations is discussed according to the mechanistic differences, emphasizing the efficacy and safety based on evidence collected from preclinical and clinical studies. Finally, we highlight the limitations of these combinations and provide suggestions for further efforts in this challenging field.

Synergistic antitumor effect of dual PI3K and mTOR inhibitor NVP-BEZ235 in combination with cisplatin on drug-resistant non-small cell lung cancer cell

Cisplatin resistance is an obstacle for the effective treatment of non-small cell lung cancer (NSCLC). The combined use of two or more chemotherapeutic agents displays advantages for the clinical treatment of drug-resistant lung cancer. The present study aimed to assess the synergy of the dual PI3K/Akt/mTOR signaling pathway inhibitor NVP-BEZ235 and cisplatin, a chemotherapeutic agent, on proliferation, apoptosis, cell cycle arrest and protein expression in cisplatin-resistant NSCLC A549/diamminedichloroplatinum resistance (DDP) cells. Cell proliferation was determined by performing Cell Counting Kit 8 and colony formation assays. Combination index (CI) was used to assess the combinatorial effects of NVP-BEZ235 and cisplatin. Cellular apoptosis and cell cycle arrest were detected via flow cytometry. Western blotting was performed to evaluate protein expression levels relative to β-actin. Cisplatin and NVP-BEZ235 displayed the strongest synergy (CI₅₀=0.23) at the mass ratio of 10:1. The half inhibitory concentrations of cisplatin and NVP-BEZ235 at 10:1 were 1.53 and 0.15 µg/ml, respectively. Compared with the control group, the combination of cisplatin and NVP-BEZ235 induced cell apoptosis and inhibited colony formation. Furthermore, compared with the control group, phosphorylation of Akt and p70S6 Kinase was significantly inhibited and cell cycle was arrested at G₀G₁ phase in the combination treatment group. The expression levels of drug efflux proteins, such as multidrug resistance-associated protein 1 and ATP-binding cassette sub-family G member 2, were significantly decreased when A549/DDP cells were treated with a combination of cisplatin and NVP-BEZ235 compared with the control group. Collectively, the present study indicated that the combined treatment of cisplatin and NVP-BEZ235 displayed synergistic antitumor effects on drug-resistant A549/DDP cells, by which the antiproliferative effects may occur via inhibition of the PI3K/Akt/mTOR signaling pathway and downregulation of drug efflux.

Synergistic Antitumor Effects of Combined Treatment with HSP90 Inhibitor and PI3K/mTOR Dual Inhibitor in Cisplatin-Resistant Human Bladder Cancer Cells

PURPOSE

The current study aimed to investigate the synergistic antitumor effect of combined treatment with 17-DMAG (HSP90 inhibitor) and NVP-BEZ235 (PI3K/mTOR dual inhibitor) on cisplatin-resistant human bladder cancer cells.

MATERIALS AND METHODS

Human bladder cancer cells exhibiting cisplatin resistance (T24R2) were exposed to escalating doses of 17-DMAG (2.5-20 nM) with or without NVP-BEZ236 (0.5-4 μM) in combination with cisplatin. Antitumor effects were assessed by CCK-8 analysis. Based on the dose-response study, synergistic interactions between the two regimens were evaluated using clonogenic assay and combination index values. Flow cytometry and Western blot were conducted to analyze mechanisms of synergism.

RESULTS

Dose- and time-dependent antitumor effects for 17-DMAG were observed in both cisplatin-sensitive (T24) and cisplatin-resistant cells (T24R2). The antitumor effect of NVP-BEZ235, however, was found to be self-limiting. The combination of 17-DMAG and NVP-BEZ235 in a 1:200 fixed ratio showed a significant antitumor effect in cisplatin-resistant bladder cancer cells over a wide dose range, and clonogenic assay showed compatible results with synergy tests. Three-dimensional analysis revealed strong synergy between the two drugs with a synergy volume of 201.84 μM/mL²%. The combination therapy resulted in G1-phase cell cycle arrest and caspase-dependent apoptosis confirmed by the Western blot.

CONCLUSION

HSP90 inhibitor monotherapy and in combination with the PI3K/mTOR survival pathway inhibitor NVP-BEZ235 shows a synergistic antitumor effect in cisplatin-resistant bladder cancers, eliciting cell cycle arrest at the G1 phase and induction of caspase-dependent apoptotic pathway.

Analysis of pulsed cisplatin signalling dynamics identifies effectors of resistance in lung adenocarcinoma

The identification of clinically viable strategies for overcoming resistance to platinum chemotherapy in lung adenocarcinoma has previously been hampered by inappropriately tailored in vitro assays of drug response. Therefore, using a pulse model that closely mimics the in vivo pharmacokinetics of platinum therapy, we profiled cisplatin-induced signalling, DNA-damage and apoptotic responses across a panel of human lung adenocarcinoma cell lines. By coupling this data to real-time, single-cell imaging of cell cycle and apoptosis we provide a fine-grained stratification of response, where a P70S6K-mediated signalling axis promotes resistance on a TP53 wildtype or null background, but not a mutant TP53 background. This finding highlights the value of in vitro models that match the physiological pharmacokinetics of drug exposure. Furthermore, it also demonstrates the importance of a mechanistic understanding of the interplay between somatic mutations and the signalling networks that govern drug response for the implementation of any consistently effective, patient-specific therapy.

Lung adenocarcinoma is the most common type of lung cancer, and it emerges because of a variety of harmful genetic changes, or mutations. Two lung cancer patients – or indeed, two different sets of cancerous cells within a patient – may therefore carry different damaging mutations.

A group of drugs called platinum-based chemotherapies are currently the most effective way to treat lung adenocarcinoma. Yet, only 30% of patients actually respond to the therapy. Many studies conducted in laboratory settings have tried to understand why most cases are resistant to treatment, with limited success.

Here, Hastings, Gonzalez-Rajal et al. propose that previous research has been inconclusive because studies done in the laboratory do not reflect how the treatment is actually administered. In patients, platinum-based drugs are cleared from the body within a few hours, but during experiments, the treatment is continually administered to cells growing in a dish.

Hastings, Gonzalez-Rajal et al. therefore developed a laboratory method that mimics the way cells are exposed to platinum-based chemotherapy in the body. These experiments showed that the lung adenocarcinoma cells which resisted treatment also carried high levels of a protein known as P70S6K. Pairing platinum-based chemotherapy with a drug that blocks the activity of P70S6K killed these resistant cells. This combination also treated human lung adenocarcinoma tumours growing under the skin of mice. However, it was ineffective on cancerous cells that carry a mutation in a protein called p53, which is often defective in cancers.

Overall, this work demonstrates the need to refine how drugs are tested in the laboratory to better reflect real-life conditions. It also underlines the importance of personalizing drug combinations to the genetic background of each tumour, a concept that will be vital to consider in future clinical trials.

Emerging Roles of Cancer Stem Cells in Bladder Cancer Progression, Tumorigenesis, and Resistance to Chemotherapy: A Potential Therapeutic Target for Bladder Cancer

Bladder cancer (BC) is a complex and highly heterogeneous stem cell disease associated with high morbidity and mortality rates if it is not treated properly. Early diagnosis with personalized therapy and regular follow-up are the keys to a successful outcome. Cancer stem cells (CSCs) are the leading power behind tumor growth, with the ability of self-renewal, metastasis, and resistance to conventional chemotherapy. The fast-developing CSC field with robust genome-wide screening methods has found a platform for establishing more reliable therapies to target tumor-initiating cell populations. However, the high heterogeneity of the CSCs in BC disease remains a large issue. Therefore, in the present review, we discuss the various types of bladder CSC heterogeneity, important regulatory pathways, roles in tumor progression and tumorigenesis, and the experimental culture models. Finally, we describe the current stem cell-based therapies for BC disease.

Wogonin Increases Cisplatin Sensitivity in Ovarian Cancer Cells Through Inhibition of the Phosphatidylinositol 3-Kinase (PI3K)/Akt Pathway

Background

Wogonin (5,7-dihydroxy-8-methoxyflavone), one of flavonoids isolated from the Scutellaria baicalensis, has been regarded as an anticancer candidate because of its maximal efficacy in cancer cells. This study aimed to explore the possible mechanism that wogonin uses to enhance the sensitivity of ovarian cancer cells to cisplatin chemotherapy.

Material/Methods

The growth inhibition rates of ovarian cancer cells SKOV3/DDP and C13* were assessed by Cell Counting Kit-8 (CCK-8) assay. The apoptosis was assessed under a fluorescence microscope following staining with Hoechst. We further analyzed the expression of Bcl-2, cleaved caspases-3, cleaved-PARP, and phospho-Akt by western blotting.

Results

In the present study, we found that wogonin reduced proliferation of ovarian cancer cells SKOV3, SKOV3/DDP, OV2008, and C13* in dose- and time-dependent manners and it sensitized cisplatin-induced cytotoxicity. Moreover, treatment with wogonin also increased cisplatin-resistant SKOV3/DDP and C13* cells to low dose cisplatin-induced cell apoptosis. Additionally, such treatment resulted in a significant decrease in phosphorylated Akt.

Conclusions

Wogonin could significantly increase the sensitivity of cisplatin-resistant ovarian cancer cells to cisplatin by downregulating the PI3K/Akt pathway.

Bioinformatics analysis of microRNA expression between patients with and without latent tuberculosis infections

Tuberculosis (TB) is a globally prevalent infectious disease. The mechanisms of latent TB infection (LTBI) remain to be fully elucidated and may provide novel approaches for diagnosis. As therapeutic targets and molecular diagnostic markers, microRNAs (miRs) have been studied and utilized in various diseases. In the present study, the differentially expressed miRs (DEMs) in LTBI were screened and analyzed to determine the underlying mechanisms and identify potential biomarkers, thereby contributing to the diagnosis of LTBI. The GSE25435 and GSE29190 datasets from Gene Expression Omnibus were selected for analysis. The 2 datasets were analyzed individually using the Bioconductor package to screen the DEMs with specific cut-off criteria [P<0.01 and |log (fold change)|≥1]. Target gene prediction and interaction network construction were performed using Targetscan, the Search Tool for the Retrieval of Interacting Genes and Proteins and Cytoscape individually, and were merged using the latter tool. The hub genes were finally selected based on their degree of connectivity (DC). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the KEGG and GENCLIP. A total of 144 DEMs were identified from the 2 datasets. By exploring the overlapping miRs in the two datasets, Homo sapiens (hsa)-miR-29a and hsa-miR-15b were identified to be decreased, while hsa-miR-576-5p, hsa-miR-500 and hsa-miR-155 were identified to be upregulated. hsa-miR-500a-3p and hsa-miR-29a-3p, as well as 4 genes, namely cell division cycle (CDC)42, actin α1, skeletal muscle (ACTA1), phosphatase and tensin homolog (PTEN) and fos proto-oncogene (FOS), were selected as the key factors in this regulatory network. A total of 9 signaling pathways, including phosphoinositide-3 kinase (PI3K)/AKT and 11 biological processes, were identified to be associated with LTBI. In conclusion, the present analysis identified hsa-miR-500a-3p and hsa-miR-29a-3p, as well as CDC42, ACTA1, PTEN and FOS, as the most promising biomarkers and therapeutic candidates for LTBI. The PI3K/AKT signaling pathway is the key signaling pathway implicated in LTBI, and an in-depth investigation of the efficiency of PI3K/AKT signaling inhibitors may be used to prevent a chronic state of infection in LTBI.

Casticin-Induced Inhibition of Cell Growth and Survival Are Mediated through the Dual Modulation of Akt/mTOR Signaling Cascade

The Akt/mTOR signaling cascade is a critical pathway involved in various physiological and pathological conditions, including regulation of cell proliferation, survival, invasion, and angiogenesis. In the present study, we investigated the anti-neoplastic effects of casticin (CTC), identified from the plant Vitex rotundifolia L., alone and/or in combination with BEZ-235, a dual Akt/mTOR inhibitor in human tumor cells. We found that CTC exerted a significant dose-dependent cytotoxicity and reduced cell proliferation in a variety of human tumor cells. Also, CTC effectively blocked the phosphorylation levels of Akt (Ser473) and mTOR (Ser2448) proteins as well as induced substantial apoptosis. Additionally treatment with CTC and BEZ-235 in conjunction resulted in a greater apoptotic effect than caused by either agent alone thus implicating the anti-neoplastic effects of this novel combination. Overall, the findings suggest that CTC can interfere with Akt/mTOR signaling cascade involved in tumorigenesis and can be used together with pharmacological agents targeting Akt/mTOR pathway.

NVP-BEZ235 Attenuated Cell Proliferation and Migration in the Squamous Cell Carcinoma of Oral Cavities and p70S6K Inhibition Mimics its Effect

NVP-BEZ235 or BEZ235 is a dual inhibitor of adenosine triphosphate (ATP)-competitive phosphoinositide 3-kinase (PI3K)/mammalian-target-of-rapamycin (mTOR) and is promising for cancer treatment. Because it targets more than one downstream effector, a dual approach is promising for cancer treatment. The aim of this study was to evaluate the efficacy of NVP-BEZ235 in treating oral cavity squamous cell carcinoma (OSCC). Two human OSCC cell lines, SCC-4 and SCC-25, were used in this study. PI3K-AKT signaling, proliferation, and cell migratory and invasion capabilities of OSCC cells were examined. In NVP-BEZ235-treated SCC-4 and SCC-25 cells, the phosphorylation of 70-kDa ribosomal S6 kinase (p70S6K), but not mTOR, decreased within 24 h. NVP-BEZ235 inhibited OSCC-cell proliferation, migration, and invasion possibly by directly deregulating the phosphorylation of p70S6K. The phospho-p70S6K inhibitor mimicked the effects of NVP-BEZ235 for preventing proliferation and weakening the migratory and invasion abilities of SCC-4 and SCC-25 cells. This study further confirmed the effect of NVP-BEZ235 on OSCC cells and provided a new strategy for controlling the proliferation, migration, and invasion of OSCC cells using the phopho-p70S6K inhibitor.

Repression of GRIM19 expression potentiates cisplatin chemoresistance in advanced bladder cancer cells via disrupting ubiquitination-mediated Bcl-xL degradation

OBJECTIVE

The mainstay of treatment for advanced bladder cancer (BC) is cisplatin (CDDP)-based systematic chemotherapy. However, acquired chemoresistance induced by as yet unidentified mechanisms is encountered frequently and often results in treatment failure and disease progression. The present study was designed to elucidate the expression and potential role of the gene associated with retinoid-interferon-induced mortality-19 (GRIM19) in the pathogenesis of CDDP resistance in BC.

METHODS

RT-qPCR and immunoblotting were employed to evaluate the expression profile of GRIM19 in clinical BC samples and in different BC cells. Using cell viability assay, apoptotic ELISA, xenografts mouse model, and Transwell assay, the effects of GRIM19 inhibition or GRIM19 overexpression on CDDP resistance were determined in different BC cells. Lastly, using co-immunoprecipitation, we provided the molecular evidence for the interaction between GRIM19 and Bcl-xL.

RESULTS

Expression levels of GRIM19 were significantly down-regulated in recurrent BC specimens, and in experimentally induced CDDP-resistant BC cells. Functionally, overexpression of the exogenous GRIM19 potentiated CDDP sensitivity and suppressed the survival and invasion of BC cells in the presence of CDDP challenge. Mechanistically, the compromised CDDP chemosensitization induced by GRIM19 loss was at least partially attributed to the attenuation of Bcl-xL polyubiquitination and subsequent degradation, because (1) GRIM19 colocalized with Bcl-xL in the mitochondria of BC cells and (2) GRIM19 overexpression promoted the ubiquitination of Bcl-xL, and this event could be effectively reversed by pretreatment with inhibitors of p38-MAPK and JNK pathways, indicating that GRIM19 overexpression-induced Bcl-xL ubiquitination may achieve in a p38/JNK-dependent manner. Using the UMUC-3 cells stably depleted of endogenous GRIM19, we further show that inhibition of Bcl-xL rectified GRIM19 deficiency-caused CDDP resistance in BC cells. In addition, BCL2L1 mRNA levels were negatively correlated with GRIM19 mRNA levels in CDDP-associated clinical BC tissues.

CONCLUSIONS

Disruption of GRIM19/Bcl-xL is a key mechanism of CDDP resistance in advanced BC. Therapeutically, enhancement of GRIM19 expression or employment of p38/JNK inhibitors may serve as resensitizing therapies for subgroups of CDDP-resistant or refractory BC patients.

NVP-BEZ235, a dual PI3K-mTOR inhibitor, suppresses the growth of FaDu hypopharyngeal squamous cell carcinoma and has a synergistic effect with Cisplatin

NVP-BEZ235 is a dual phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) inhibitor. A dual approach targeting more than one downstream effector is a promising strategy for treating cancers. The aim of this study was to evaluate the effect of NVP-BEZ235 in treating FaDu hypopharyngeal squamous cell carcinoma (HSCC), either alone or in combination with cisplatin. We found mTOR expression was higher in patients with HSCC. In the in vitro study, treatment with NVP-BEZ235 alone attenuated cell proliferation and suppressed p-p70S6K and p-4E-BP1 expression in FaDu cells. When NVP-BEZ235 was combined with Cisplatin, apoptosis was induced more effectively than with either drug alone. In mice with a FaDu xenograft, cotreatment with NVP-BEZ235 and Cisplatin engendered synergistic effects and produced a greater antitumor response than did treatment with either drug alone. Resected tumor samples also showed decreased p-p70S6K expression. Collectively, these data demonstrate that NVP-BEZ235 inhibits HSCC growth through phospho-p70S6K suppression and has a synergistic effect with Cisplatin in treating HSCC. The data also provide a strategy for more effective HSCC treatment.

Dual mTOR/PI3K inhibition limits PI3K-dependent pathways activated upon mTOR inhibition in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the development of kidney cysts leading to kidney failure in adulthood. Inhibition of mammalian target of rapamycin (mTOR) slows polycystic kidney disease (PKD) progression in animal models, but randomized controlled trials failed to prove efficacy of mTOR inhibitor treatment. Here, we demonstrate that treatment with mTOR inhibitors result in the removal of negative feedback loops and up-regulates pro-proliferative phosphatidylinositol 3-kinase (PI3K)-Akt and PI3K-extracellular signal-regulated kinase (ERK) signaling in rat and mouse PKD models. Dual mTOR/PI3K inhibition with NVP-BEZ235 abrogated these pro-proliferative signals and normalized kidney morphology and function by blocking proliferation and fibrosis. Our findings suggest that multi-target PI3K/mTOR inhibition may represent a potential treatment for ADPKD.

Colorectal cancer lung metastasis treatment with polymer-drug nanoparticles

Colorectal cancer (CRC) is the second leading cause of cancer deaths in the United States; the predominant cause for mortality is metastasis to distant organs (e.g., lung). A major problem limiting the success of chemotherapy in metastatic CRC is the inability to target tumor tissues selectively and avoid severe side effects to normal tissues and organs. Here, we demonstrate polymeric nanoparticles (PNPs) entrapping chemotherapeutic agents provide a new therapeutic option for treating CRC that has metastasized to the lung. PNPs assembled from FDA approved biocompatible block copolymer accumulated predominantly in lung tissue. PNPs showed negligible accumulation in liver, spleen and kidneys, which was confirmed by fluorescent nanoparticle imaging and analysis of PI3K inhibition in the organs. PNPs entrapping PI3K inhibitors (i.e., wortmannin and PX866) suppressed CRC lung metastasis growth, and SN-38-loaded PNPs completely eliminated CRC lung metastasis. Our results demonstrate that polymer-drug nanoparticles offer a new approach to reduce toxicity of cancer therapy and has the potential to improve outcomes for patients with lung metastasis.

Targeting the PI3K/AKT/mTOR Pathway in Bladder Cancer

The PI3K/AKT/mTOR signaling pathway shows frequent molecular alterations and increased activity in cancer. Given its role in the regulation of cell growth, survival and metastasis, molecules within this pathway are promising targets for pharmacologic intervention. Metastatic bladder cancer (BLCA) continues to have few treatment options. Although various molecular alterations in PI3K/AKT/mTOR signaling have been described in BLCA, clinical trials with small molecule inhibitors have not met their endpoints. In this article, we summarize results from preclinical studies and clinical trials that examined PI3K pathway inhibitors in BLCA focusing on technical challenges that might result in contradictory findings in preclinical studies. Based on published data from our group, we also address challenges that need to be overcome to optimize PI3K inhibition in BLCA and enable its successful translation into the clinic.

GSK3β-dependent cyclin D1 and cyclin E1 degradation is indispensable for NVP-BEZ235 induced G0/G1 arrest in neuroblastoma cells

Cyclin D1 and cyclin E1, as vital regulatory factors of G1-S phase cell cycle progression, are frequently constitutive expressed and associated with pathogenesis and tumorigenesis in most human cancers and they have been regarded as promising targets for cancer therapy. In this study, we established NVP-BEZ235, a potent dual kinase inhibitor, could induce neuroblastoma cells proliferation inhibition without apoptosis activation. Moreover, we showed NVP-BEZ235 could induce neuroblastoma cells arrested at G0/G1 phase accompanied with significant reduction of the cyclin D1 and E1 proteins in a dose dependent manner at nanomole concentration. Additionally we found that GSK3β was dephosphorylated and activated by NVP-BEZ235 and then triggered cyclin D1 and cyclin E1 degradation through ubiquitination proteasome pathway, based on the evidences that NVP-BEZ235 induced downregulation of cyclin D1 and cyclin E1 were obviously recovered by proteasome inhibitor and the blockade of GSK3β contributed to remarkable rescue of cyclin D1 and cyclin E1. Analogous results about its anti-proliferation effects and molecular mechanism were observed on neuroblastoma xenograft mouse model in vivo. Therefore, these results indicate that NVP-BEZ235-induced cyclin D1 and cyclin E1 degradation, which happened through activating GSK3β, and GSK3β-dependent down-regulation of cyclin D1 and cyclin E1 should be available for anticancer therapeutics.

Inhibition of PI3K/Akt/mTOR overcomes cisplatin resistance in the triple negative breast cancer cell line HCC38

Background

Widely established targeted therapies directed at triple negative breast cancer (TNBC) are missing. Classical chemotherapy remains the systemic treatment option. Cisplatin has been tested in TNBC but bears the disadvantage of resistance development. The purpose of this study was to identify resistance mechanisms in cisplatin-resistant TNBC cell lines and select targeted therapies based on these findings.

Methods

The TNBC cell lines HCC38 and MDA-MB231 were subjected to intermittent cisplatin treatment resulting in the 3.5-fold cisplatin-resistant subclone HCC38CisR and the 2.1-fold more resistant MDA-MB231CisR. Activation of pro-survival pathways was explored by immunostaining of phospho-receptor tyrosine kinases. Targeted therapies (NVP-AEW541, lapatinib and NVP-BEZ235) against activated pathways were investigated regarding cancer cell growth and cisplatin sensitivity.

Results

In HCC38CisR and MDA-MB231CisR, phosphorylation of epidermal growth factor receptor (EGFR) and insulin-like growth factor 1 receptor (IGF1R) was observed. In HCC38CisR, treatment with NVP-AEW541 increased potency of lapatinib almost seven-fold, but both compounds could not restore cisplatin sensitivity. However, the dual phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitor NVP-BEZ235 acted synergistically with cisplatin in HCC38CisR and fully restored cisplatin sensitivity. Similarly, NVP-BEZ235 increased cisplatin potency in MDA-MB231CisR. Furthermore, NVP-AEW541 in combination with lapatinib restored cisplatin sensitivity in MDA-MB231CisR.

Conclusion

Simultaneous inhibition of EGFR and IGF1R in cisplatin-resistant TNBC cell lines was synergistic regarding inhibition of proliferation and induction of apoptosis. Co-treatment with NVP-BEZ235 or with a combination of NVP-AEW541 and lapatinib restored cisplatin sensitivity and may constitute a targeted treatment option for cisplatin-resistant TNBC.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3695-5) contains supplementary material, which is available to authorized users.

Targeted inhibition of the phosphoinositide 3-kinase impairs cell proliferation, survival, and invasion in colon cancer

Background

Colon cancer is the third most common cancer in the world, and its metastasis and drug resistance are challenging for its effective treatment. The PI3K/Akt/mTOR pathway plays a crucial role in the pathogenesis of colon cancer. The aim of this study was to investigate the targeting of PI3K in colon cancer cells HT-29 and HCT-116 in vitro.

Methods

In HT-29 and HCT-116 cells, BEZ235, a dual inhibitor of PI3K/mTOR, and shRNAtarget to PI3KCA were used to inhibit PI3K/Akt/mTOR pathway. The inhibition efficiency of PI3K/Akt/mTOR pathway was detected by RT-PCR and Western blot. Cell proliferation, migration, invasion, and apoptosis were evaluated by Cell Counting Kit-8, Transwell, and flow cytometry assays. The expression of apoptosis-related proteins (cleavage caspase 3, Bcl-2, Bax, and Bim) were also detected.

Results

We found that in HT-29 and HCT-116 cells, the treatment of BEZ235 (1 μM) and PI3KCA knockdown inhibited the activation of PI3K/Akt/mTOR pathway and significantly suppressed cell proliferation, migration, and invasion of HT-29 and HCT-116 cells. In addition, we confirmed that knockdown of BEZ235 and PI3KCA induced cell apoptosis through the upregulated levels of cleavage caspase 3 and Bax and downregulated expression of Bcl-2 and Bim.

Conclusion

Our results indicated that targeted inhibition of the PI3K/Akt/mTOR pathway impaired cell proliferation, survival, and invasion in human colon cancer.

Interleukin-27 augments the inhibitory effects of sorafenib on bladder cancer cells

Both sorafenib and interleukin-27 (IL-27) are antineoplastic drugs. This study aimed to investigate the synergistic effect of these two drugs on bladder cancer cells. HTB-9 and T24 cells were stimulated with IL-27 (50 ng/mL), sorafenib (2 μM) or the synergistic action of these two drugs. The cells without treatment acted as control. Cell proliferation, apoptosis and invasion were measured by bromodeoxyuridine assay, flow cytometry and modified Boyden chamber, respectively. Simultaneously, both modified Boyden chamber and scratch assay were used to assess cell migration. Finally, the phosphorylation levels of key kinases in the Akt/mechanistic target of rapamycin (mTOR)/mitogen-activated protein kinase (MAPK) pathway, and expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 were detected by western blot analysis. Stimulation with IL-27 or sorafenib repressed proliferation, migration and invasion but promoted apoptosis, and the effects were all enhanced by the combination of these two drugs in HTB-9 cells. The effect of the combined treatment on bladder cancer cells was verified in T24 cells. Additionally, the phosphorylation levels of AKT, mTOR and MAPK as well as the expression levels of MMP-2 and MMP-9 were all decreased by a single treatment of IL-27 or sorafenib, and further decreased by the combined treatment of these two drugs. The combination of IL-27 and sorafenib inhibited proliferation, migration and invasion and promoted apoptosis of bladder cancer cells compared with mono-drug treatment. Additionally, the AKT/mTOR/MAPK pathway might be implicated in the functional effects by down-regulations of MMP-2 and MMP-9.

Effects of endoplasmic reticulum stress on the autophagy, apoptosis, and chemotherapy resistance of human breast cancer cells by regulating the PI3K/AKT/mTOR signaling pathway

Nowadays, although chemotherapy is an established therapy for breast cancer, the molecular mechanisms of chemotherapy resistance in breast cancer remain poorly understood. This study aims to explore the effects of endoplasmic reticulum stress on autophagy, apoptosis, and chemotherapy resistance in human breast cancer cells by regulating PI3K/AKT/mTOR signaling pathway. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect the cell viability of six human breast cancer cell lines (MCF-7, ZR-75-30, T47D, MDA-MB-435s, MDA-MB-453, and MDA-MB-231) treated with tunicamycin (5 µM), after which MCF-7 cells were selected for further experiment. Then, MCF-7 cells were divided into the control (without any treatment), tunicamycin (8 µ), BEZ235 (5 µ), and tunicamycin + BEZ235 groups. Cell viability of each group was testified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Western blotting was applied to determine the expressions of endoplasmic reticulum stress and PI3K/AKT/mTOR pathway-related proteins and autophagy- and apoptosis-related proteins. Monodansylcadaverine and Annexin V-fluorescein isothiocyanate/propidium iodide staining were used for determination of cell autophagy and apoptosis. Furthermore, MCF-7 cells were divided into the control (without any treatment), tunicamycin (5 µM), cisplatin (16 µM), cisplatin (16 µM) + BEZ235 (5 µM), tunicamycin (5 µM) + cisplatin (16 µM), and tunicamycin (5 µM) + cisplatin (16 µM) + BEZ235 groups. Cell viability and apoptosis were also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Annexin V-fluorescein isothiocyanate/propidium iodide staining. In MCF-7 cells treated with tunicamycin, cell viability decreased significantly, but PEAK, eIF2, and CHOP were upregulated markedly and p-PI3K, p-AKT, and p-MTOR were downregulated in dose- and time-dependent manners. In the tunicamycin + BEZ235 group, the cell viability was lower and the apoptosis rate was higher than those of the control and monotherapy groups. Compared with the cisplatin group, the tunicamycin + cisplatin group showed a relatively higher growth inhibition rate; the growth inhibition rate substantially increased in the tunicamycin + cisplatin + BEZ235 group than the tunicamycin + cisplatin group. The apoptosis rate was highest in tunicamycin + cisplatin + BEZ235 group, followed by tunicamycin + cisplatin group and then cisplatin group. Our study provide evidence that endoplasmic reticulum stress activated by tunicamycin could promote breast cancer cell autophagy and apoptosis and enhance chemosensitivity of MCF-7 cells by inhibiting the PI3K/AKT/mTOR signaling pathway.

Design, synthesis and pharmaco-toxicological assessment of 5-mercapto-1,2,4-triazole derivatives with antibacterial and antiproliferative activity

The extensive biochemical research of multiple types of cancer has revealed important enzymatic signaling pathways responsible for tumor occurrence and progression, thus compelling the need for the discovery of new means with which to block these signaling cascades. The phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway, which plays an important role in maintaining relevant cellular functions, exhibits various alterations in common human cancers, thus representing a suitable target in cancer treatment. Molecules bearing the 1,2,4-triazole moiety are known to possess multiple biological activities, including anticancer activity. The current study used molecular docking in the design of 5-mercapto-1,2,4-triazole derivatives with antiproliferative activity targeting the PI3K/AKT pathway. Three structures emerged as the result of this method, which indicated for these a highly favorable accommodation within the active binding site of PI3K protein, thus acting as potential PI3K inhibitors, and hence interfering with the above-mentioned pathway. The molecules were synthesized and their chemical structure was confirmed. The antiproliferative activity of these compounds was tested on 4 cancer cell lines (A375, B164A5, MDA-MB-231 and A549) and on normal human keratinocytes (HaCaT) by in vitro alamarBlue assay. The 3 compounds revealed antitumor activity against the breast cancer cell line (MDA-MB-231) and reduced toxicity on the normal cell line. The antibacterial activity of the compounds was also tested in vitro on Gram-positive and Gram-negative bacterial strains, revealing moderate activity.

Gambogenic acid synergistically potentiates bortezomib-induced apoptosis in multiple myeloma

Background: Although the introduction of protease inhibitor bortezomib (BTZ) and immunomodulatory agent lenalidomide has led to improved outcomes in patients with multiple myeloma (MM), the disease remains incurable. Gambogenic acid (GNA), a polyprenylated xanthone isolated from the traditional Chinese medicine gamboge, has been reported to have potent antitumor activity and can effectively inhibit the survival and proliferation of cancer. In this study, we hypothesized that GNA could synergistically potentiate BTZ-induced apoptosis of MM cells and that combining BTZ and GNA may provide a more effective approach to treat MM. Hence, we investigate the in vitro and in vivo effects of BTZ and GNA, alone or in combination, against myeloma MM.1S cells.

Methods: Cell counting kit-8 (CCK-8) assay, combination index (CI) isobologram, flow cytometry, western blot, xenograft tumor models, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunochemistry were used in this study.

Results: The results showed that BTZ and GNA combination treatment resulted in a strong synergistic action against the MM.1S cell line. Increased G2/M phase cells were triggered by BTZ, GNA and the combined treatment. The combined treatment could induce more markedly apoptosis of MM.1S cells via the activation of PARP cleavage, P53, Caspase-3 cleavage and Bax and inhibition of Bcl-2 expression. An increased antitumor effects of combination therapy of BTZ and GNA on MM.1S xenograft models were observed, and combining BTZ and GNA was found to be superior to a single agent.

Conclusions: Our data support that a synergistic antitumor activity exists between BTZ and GNA, and provide a rationale for successful utilization of dual BTZ and GNA in MM chemotherapy in the future.

Simultaneous Targeting of Bladder Tumor Growth, Survival, and Epithelial-to-Mesenchymal Transition with a Novel Therapeutic Combination of Acetazolamide (AZ) and Sulforaphane (SFN)

BACKGROUND

Current chemotherapies for advanced stage metastatic bladder cancer often result in severe side effects, and most patients become drug resistant over time. Thus, there is a need for more effective therapies with minimal side effects.

OBJECTIVE

The acid/base balance in tumor cells is essential for tumor cell functioning. We reasoned that simultaneous targeting of pH homeostasis and survival pathways would improve therapeutic efficacy. We evaluated the effectiveness of targeting pH homeostasis with the carbonic anhydrase inhibitor acetazolamide (AZ) in combination with the survival pathway targeting isothiocyanate sulforaphane (SFN) on the HTB-9 and RT112(H) human bladder tumor cell lines.

MATERIALS AND METHODS

We assessed viability, proliferation, and survival in vitro and effect on xenografts in vivo.

RESULTS

Combination AZ + SFN treatment induced dose-dependent suppression of growth, produced a potent anti-proliferative and anti-clonogenic effect, and induced apoptosis through caspase-3 and PARP activation. The anti-proliferative effect was corroborated by significant reductions in Ki-67, pHH3, cyclin D1, and sustained induction of the cell cycle inhibitors, p21 and p27. Both active p-Akt (Ser473) and p-S6 were significantly downregulated in the AZ + SFN combination treated cells with a concomitant inhibition of Akt kinase activity. The inhibitory effects of the AZ + SFN combination treatment showed similar efficacy as the dual PI3K/mTOR pathway inhibitor NVP-BEZ235, albeit at an expected higher dose. In terms of the effect on the metastatic potential of these bladder cancers, we found downregulated expression of carbonic anhydrase 9 (CA9) concomitant with reductions in both E-cadherin, N-cadherin, and vimentin proteins mitigating the epithelial-to-mesenchymal transition (EMT), suggesting negation of this program.

CONCLUSION

We suggest that reductions in these components could be linked with downregulation of the survival mediated Akt pathway and suggested an active role of the Akt pathway in bladder cancer. Altogether, our in vitro and pre-clinical model data support the potential use of an AZ + SFN combination for the treatment of bladder cancer.

NHERF1 Enhances Cisplatin Sensitivity in Human Cervical Cancer Cells

Cervical cancer is one of the most common female malignancies, and cisplatin-based chemotherapy is routinely utilized in locally advanced cervical cancer patients. However, resistance has been the major limitation. In this study, we found that Na⁺/H⁺ Exchanger Regulatory Factor 1 (NHERF1) was downregulated in cisplatin-resistant cells. Analysis based on a cervical cancer dataset from The Cancer Genome Atlas (TCGA) showed association of NHERF1 expression with disease-free survival of patients received cisplatin treatment. NHERF1 overexpression inhibited proliferation and enhanced apoptosis in cisplatin-resistant HeLa cells, whereas NHERF1 knockdown had inverse effects. While parental HeLa cells were more resistant to cisplatin after NHERF1 knockdown, NHERF1 overexpression in CaSki cells promoted cisplatin sensitivity. Overexpression and knockdown studies also showed that NHERF1 significantly inhibited AKT and extracellular signal–regulated kinase (ERK) signaling pathways in cisplatin-resistant cells. Taken together, our results provide the first evidence that NHERF1 can sensitize cisplatin-refractory cervical cancer cells. This study may help to increase understanding of the molecular mechanisms underlying cisplatin resistance in tumors.

Downregulation of DOCK1 sensitizes bladder cancer cells to cisplatin through preventing epithelial-mesenchymal transition

During the past several decades, resistance to single or multiple anticancer agents has posed a great challenge in cancer therapy. Dedicator of cytokinesis 1 (DOCK1), the first identified member in DOCK family, plays diverse roles in cellular processes, including tumorigenesis. In this study, we explored the biological role of DOCK1 in the chemotherapeutic resistance in bladder cancer and its underlying mechanism. Our results showed that the bladder cancer cell lines UM-UC-3 and J82 with higher DOCK1 are more resistant to cisplatin, whereas B87 cells with the lowest expression of DOCK1 exhibited the highest sensitivity to cisplatin. Down-regulation of DOCK1 with small interfering RNA (siRNA) increased the cisplatin sensitivity in bladder cancer cells. Moreover, treatment with cisplatin induced epithelial–mesenchymal transition (EMT), while transfection with Twist siRNA restored the chemosensitivity to cisplatin. In addition, we found that downregulation of DOCK1 reversed EMT program in bladder cancer cells. However, cotransfection with DOCK1 siRNA could not further enhance the cisplatin sensitivity and cellular phenotypic changes in tumor cells. Taken together, these results demonstrate that downregulation of DOCK1 could increase the chemosensitivity in bladder cancer cells via preventing cisplatin-induced EMT, suggesting that DOCK1 may serve as a potential therapeutic target in bladder cancer.

Isoquercitrin inhibits bladder cancer progression in vivo and in vitro by regulating the PI3K/Akt and PKC signaling pathways

Bladder cancer is the most common malignancy of the urinary system and is also one of the 10 most common cancers of the human body. Currently, clinical treatment of bladder cancer mainly utilizes partial or total cystectomy, supplemented by conventional chemotherapy. However, such treatment has not fully improved the prognosis of patients and is associated with various side effects. Studies have found that flavonoids extracted from plants can be used in radiotherapy and chemotherapy for the prevention of postoperative recurrence and metastasis but also alone for the treatment of advanced tumors. Both applications can ameliorate clinical symptoms, improve the quality of life, and prolong the survival of patients. Based on the above information, the present study investigated the effect of isoquercitrin, a type of flavonoid found in Bidens pilosa L. extracts, on bladder cancer progression, with the goal of understanding the biological characteristics of isoquercitrin by which it participates in bladder cancer progression. Using in vitro experiments, we found that therapeutic doses of isoquercitrin significantly inhibited cell proliferation and induced apoptosis in human bladder cancer cells and that the cell cycle was arrested in the G1 phase. Isoquercitrin inhibited phosphatidylinositol 3-kinase (PI3K) and Akt phosphorylation expression levels, thus inhibiting proliferation and inducing apoptosis in the cancer cells. In addition, we found that isoquercitrin reduced protein kinase C (PKC) protein expression levels in the human bladder cancer cell lines. We also showed via in vivo experiments that isoquercitrin inhibited xenograft tumor growth in nude mice. In conclusion, our study confirmed that isoquercitrin inhibits bladder cancer progression in vivo and demonstrated that the molecular mechanism of this inhibition may be closely associated with the PI3K/Akt and PKC signaling pathways.

Blockage of Autophagy Rescues the Dual PI3K/mTOR Inhibitor BEZ235-induced Growth Inhibition of Colorectal Cancer Cells

Molecular targeting for the altered signaling pathways has been proven to be effective for the treatment ofmany types of human cancer, including colorectal cancer (CRC). The dual phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitor BEZ235 has shown to exhibit potent antitumor activity against solid tumors. Autophagy is a cellular lysosomal catabolic process to maintain metabolic homeostasis, which has been known to be induced in response to many therapeutic agents in cancer cells. This process is negatively regulated by mTOR and often acts as prosurvival or prodeath mechanism following cancer therapeutics. The current study was designed to investigate the antiproliferation activity of BEZ235 and to evaluate the role of autophagy induced by BEZ235 using HCT15 CRC cells bearing ras oncogene mutation. We found that BEZ235 decreases cell viability, which was mostly dependent on G1 arrest of cell cycle via suppression of cyclin A expression. BEZ235 affects PI3K/Akt/mTOR signaling pathway by increasing the phosphorylation of AKT at Ser(473) and RAS/RAF/MEK/ERK pathway by decreasing the phosphorylation of ERK at Tyr(204). BEZ235 also stimulated autophagy induction as evidenced by the increased expression of LC3-II and abundant acidic vesicular organelles (AVOs) in the cytoplasm. In addition, the combination of BEZ235 with autophagy inhibitor chloroquine, a known antagonist of autophagy, counteracted the antiproliferation effect of BEZ235. Thus, our study indicates that autophagy induced in response to BEZ235 treatment appears to act as cell death mechanism in HCT15 CRC cells.

Phase II study of dual phosphoinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitor BEZ235 in patients with locally advanced or metastatic transitional cell carcinoma

OBJECTIVE

To assess, in a multicentre phase II trial, the safety and efficacy of BEZ235, an oral pan-class I phosphoinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) complex1/2 inhibitor, in locally advanced or metastatic transitional cell carcinoma (TCC) after failure of platinum-based therapy.

PATIENTS AND METHODS

Patients with locally advanced or metastatic TCC progressing after platinum therapy were prospectively stratified by PI3K/Akt/mTOR pathway alterations, defined as PTEN loss and PIK3CA mutation. All patients received BEZ235 until progressive disease or unacceptable toxicity. The primary endpoint was the progression-free survival (PFS) rate at 16 weeks. This study was, however, closed prematurely because BEZ235 was withdrawn from further development.

RESULTS

A total of 20 patients (18 without and two with PI3K/Akt/mTOR alterations) were enrolled and received BEZ235. One partial response (5%) and two cases of stable disease (10%) were observed, all in patients without PI3K/mTOR pathway alterations. The PFS rate at 8 and 16 weeks was 15 and 10%, respectively; the median (range) PFS was 62 (38-588) days (95% confidence interval [CI] 53-110); and the median (range) overall survival was 127 (41-734) days (95% CI 58-309). Among the 90% of patients who experienced drug-related adverse events of any grade, 50% experienced grade 3-4 adverse events, including stomatitis (15%), fatigue (5%), nausea (5%), diarrhoea (5%), renal failure (5%), cutaneous rash (5%), hepatotoxicity (5%) and hypertension (5%).

CONCLUSION

BEZ235 showed modest clinical activity and an unfavourable toxicity profile in patients with advanced and pretreated TCC; however, a minority of patients experienced a clinical benefit, suggesting that a complete blockade of the PI3K/mTOR axis could improve outcome in some specific patients. Furthermore, this study showed that molecular stratification of patients for personalized medicine before treatment is feasible.

miR-222 attenuates cisplatin-induced cell death by targeting the PPP2R2A/Akt/mTOR Axis in bladder cancer cells

Increased miR-222 levels are associated with a poor prognosis in patients with bladder cancer. However, the role of miR-222 remains unclear. In the present study, we found that miR-222 enhanced the proliferation of both the T24 and the 5637 bladder cancer cell lines. Overexpression of miR-222 attenuated cisplatin-induced cell death in bladder cancer cells. miR-222 activated the Akt/mTOR pathway and inhibited cisplatin-induced autophagy in bladder cancer cells by directly targeting protein phosphatase 2A subunit B (PPP2R2A). Blocking the activation of Akt with LY294002 or mTOR with rapamycin significantly prevented miR-222-induced proliferation and restored the sensitivity of bladder cancer cells to cisplatin. These findings demonstrate that miR-222 modulates the PPP2R2A/Akt/mTOR axis and thus plays a critical role in regulating proliferation and chemotherapeutic drug resistance. Therefore, miR-222 may be a novel therapeutic target for bladder cancer.

Inhibition of epithelial-mesenchymal transition in bladder cancer cells via modulation of mTOR signalling

Mounting evidence suggests that signalling cross-talk plays a significant role in the regulation of epithelial-mesenchymal transition (EMT) in cancer cells. However, the complex network regulating the EMT in different cancer types has not been fully described yet which affects the development of novel therapeutic strategies. In the present study, we investigated the signalling pathways involved in EMT of bladder cancer cells and demonstrated the effects of two novel agents in the regulation of EMT. Myrtucommulone-A (MC-A) and thymoquinone (TQ) have been shown to possess anti-cancer properties. However, their targets in the regulation of cancer cell behavior are not well defined. Here, we defined the effects of two putative anti-cancer agents on bladder cancer cell migration and their possible intracellular targets in the regulation of EMT. Our results suggest that MC-A or TQ treatment affected N-cadherin, Snail, Slug, and β-catenin expressions and effectively attenuated mTOR activity. The downstream components in mTOR signalling were also affected. MC-A treatment resulted in the concomitant inhibition of extracellular matrix-regulated protein kinases 1 and 2 (ERK 1/2), p38 mitogen-activated protein kinase (MAPK) and Src activity. On the other hand, TQ treatment increased Src activity while exerting no effect on ERK 1/2 or p38 MAPK activity. Given the stronger inhibition of EMT-related markers in MC-A-treated samples, we concluded that this effect might be due to collective inhibition of multiple signalling pathways which result in a decrease in their cross-talk in bladder cancer cells. Overall, the data in this study proposes novel action mechanisms for MC-A or TQ in bladder cancer cells and highlights the potential use of these active compounds in the regulation of EMT.

Muscle-invasive urothelial bladder cancer: an update on systemic therapy

Urothelial carcinoma is a common malignancy that carries a poor prognosis when the disease includes muscle invasion. Metastatic urothelial carcinoma is almost uniformly fatal. The evidence behind treatment options in the neoadjuvant, adjuvant and metastatic settings are discussed in this manuscript, with a focused review of standard and investigational cytotoxic, targeted, and immunotherapy approaches. We have focused especially on neoadjuvant cisplatin-based therapy (supported by level one evidence) and on novel immunotherapy agents such as checkpoint inhibitors, which have shown great promise in early clinical studies.

Targeted Inhibition of Phosphoinositide 3-Kinase/Mammalian Target of Rapamycin Sensitizes Pancreatic Cancer Cells to Doxorubicin without Exacerbating Cardiac Toxicity

Pancreatic cancer has the lowest 5-year survival rate of all major cancers despite decades of effort to design and implement novel, more effective treatment options. In this study, we tested whether the dual phosphoinositide 3-kinase/mechanistic target of rapamycin inhibitor BEZ235 (BEZ) potentiates the antitumor effects of doxorubicin (DOX) against pancreatic cancer. Cotreatment of BEZ235 with DOX resulted in dose-dependent inhibition of the phosphoinositide 3-kinase/mechanistic target of rapamycin survival pathway, which corresponded with an increase in poly ADP ribose polymerase cleavage. Moreover, BEZ cotreatment significantly improved the effects of DOX toward both cell viability and cell death in part through reduced Bcl-2 expression and increased expression of the shorter, more cytotoxic forms of BIM. BEZ also facilitated intracellular accumulation of DOX, which led to enhanced DNA damage and reactive oxygen species generation. Furthermore, BEZ in combination with gemcitabine reduced MiaPaca2 cell proliferation but failed to increase reactive oxygen species generation or BIM expression, resulting in reduced necrosis and apoptosis. Treatment with BEZ and DOX in mice bearing tumor xenographs significantly repressed tumor growth as compared with BEZ, DOX, or gemcitabine. Additionally, in contrast to the enhanced expression seen in MiaPaca2 cells, BEZ and DOX cotreatment reduced BIM expression in H9C2 cardiomyocytes. Also, the Bcl-2/Bax ratio was increased, which was associated with a reduction in cell death. In vivo echocardiography showed decreased cardiac function with DOX treatment, which was not improved by combination treatment with BEZ. Thus, we propose that combining BEZ with DOX would be a better option for patients than current standard of care by providing a more effective tumor response without the associated increase in toxicity.

MicroRNA-H4-5p encoded by HSV-1 latency-associated transcript promotes cell proliferation, invasion and cell cycle progression via p16-mediated PI3K-Akt signaling pathway in SHSY5Y cells

Herpes simplex virus 1 (HSV-1) microRNAs (miRNAs) mostly located in transcription-associated transcript (LAT) region have been identified that play critical roles in the intricate host-pathogen interaction networks. Increasing evidences throw new insight into the role of miRNA-mediated miRNA-mRNA cross-talk in HSV-1 latent or acute infection. In the present study, we found that hsv-1 miR-H4-5p (here termed as miR-H4b) can down-regulate the expression of cyclin-dependent kinase inhibitor 2A (CDKN2A, p16) in neuroblastoma (SHSY5Y) cell lines. Decreased expression of miR-H4b was directly related to attenuated cell proliferation and invasion as well as malfunction of cell cycle in recombinant SHSY5Y cells that stably expressing miR-H4b. Bioinformatics analysis and luciferase assays demonstrated miR-H4b can directly target p16 mRNA. MiR-H4b exerts its pro-proliferation function through inhibition of the p16-related PI3K-Akt pathways. Our findings provide, for the first time, significant clues regarding the role of herpesvirus-encoded miRNAs as a viral modulator to host cells.

Dual blockade of PI3K/AKT/mTOR (NVP-BEZ235) and Ras/Raf/MEK (AZD6244) pathways synergistically inhibit growth of primary endometrioid endometrial carcinoma cultures, whereas NVP-BEZ235 reduces tumor growth in the corresponding xenograft models

OBJECTIVES

Endometrial carcinoma (EC) is the most common gynecological cancer in the Western World. Treatment options are limited for advanced and recurrent disease. Therefore, new treatment options are necessary. Inhibition of the PI3K/AKT/mTOR and/or the Ras/Raf/MEK pathways is suggested to be clinically relevant. However, the knowledge about the effect of combination targeted therapy in EC is limited. The aim of this study was to investigate the effect of these therapies on primary endometrioid EC cell cultures in vitro and in vivo.

METHODS

Primary endometrioid EC cell cultures were incubated with Temsirolimus (mTORC1 inhibitor), NVP-BKM120 (pan-PI3K inhibitor), NVP-BEZ235 (pan-PI3K/mTOR inhibitor), or AZD6244 (MEK1/2 inhibitor) as single treatment. In vitro, the effect of NVP-BEZ235 with or without AZD6244 was determined for cell viability, cell cycle arrest, apoptosis induction, and cell signaling. In vivo, the effect of NVP-BEZ35 was investigated for 2 subcutaneous xenograft models of the corresponding primary cultures.

RESULTS

NVP-BEZ235 was the most potent PI3K/AKT/mTOR pathway inhibitor. NVP-BEZ235 and AZD6244 reduced cell viability and induced cell cycle arrest and apoptosis, by reduction of p-AKT, p-S6, and p-ERK levels. Combination treatment showed a synergistic effect. In vivo, NVP-BEZ235 reduced tumor growth and inhibited p-S6 expression. The effects of the compounds were independent of the mutation profile of the cell cultures used.

CONCLUSIONS

A synergistic antitumor effect was shown for NVP-BEZ235 and AZD6244 in primary endometrioid EC cells in vitro. In addition, NVP-BEZ235 induced reduction of tumor growth in vivo. Therefore, targeted therapies seem an interesting strategy to further evaluate in clinical trials.

Activity of the novel dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor NVP-BEZ235 against osteosarcoma

Recent studies have identified that constitutively active phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling is an important feature of osteosarcoma, where it promotes cell proliferation, survival, and chemo-resistance. Here, we studied the therapeutic potential of NVP-BEZ235, a novel dual PI3K/mTOR dual inhibitor, on osteosarcoma cells in vivo and in vitro. NVP-BEZ235 was cytotoxic and cytostatic to a panel of osteosarcoma lines (MG-63, U2OS and SaOs-2), where it induce apoptosis and cell-cycle arrest. At the molecular level, NVP-BEZ235 inhibited PI3K-AKT-mTORC1 activation and downregulated cyclin D1/cyclin B1 expressions, while increasing MEK/Erk phosphorylation in osteosarcoma cells. MEK/Erk inhibitors PD98059 and MEK-162 increased NVP-BEZ235 activity on osteosarcoma cells. In vivo, oral NVP-BEZ235 inhibited U2OS xenograft in SCID mice, and its anti-tumor efficiency was further enhanced by MEK-162 co-administration. Taken together, our findings indicate that dual inhibition of PI3K and mTOR with NVP-BEZ235, either alone or in combination with MEK/Erk inhibitors, may be an efficient treatment for osteosarcoma.

MicroRNA-199a-3p suppresses glioma cell proliferation by regulating the AKT/mTOR signaling pathway

Glioma has been investigated for decades, but the prognosis remains poor because of rapid proliferation, its aggressive potential, and its resistance to chemotherapy or radiotherapy. The mammalian target of rapamycin (mTOR) is highly expressed and regulates cellular proliferation and cell growth. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene transcription and translation via up-regulating or down-regulating the levels of miRNAs. This study was conducted to explore the molecular functions of miR-199a-3p in glioma. We detected the expression of miR-199a-3p in glioma samples by quantitative PCR (qPCR). Then, we transfected the U87 and U251 cell lines with miR-199a-3p. Cellular proliferation, invasion, and apoptosis were assessed to explain the function of miR-199a-3p. PCR confirmed that the expression of miR-199a-3p was lower in glioma samples combined with normal brain tissues. The over-expression of miR-199a-3p might target mTOR and restrained cellular growth and proliferation but not invasive and apoptosis capability. Results indicated that cellular proliferation was inhibited to regulate the AKT/mTOR signaling pathway by elevating levels of miR-199a-3p. MiR-199a-3p in glioma cell lines has effects similar to the tumor suppressor gene on cellular proliferation via the AKT/mTOR signaling pathway.