Atorvastatin sensitizes human non-small cell lung carcinomas to carboplatin via suppression of AKT activation and upregulation of TIMP-1

Identification of biomarkers, pathways, and therapeutic targets for EGFR-TKI resistance in NSCLC

This study aimed to map the hub genes and potential pathways that might be involved in the molecular pathogenesis of EGFR-TKI resistance in NSCLC. We performed bioinformatics analysis to identify differentially expressed genes, their function, gene interactions, and pathway analysis between EGFR-TKI-sensitive and EGFR-TKI-resistant patient-derived xenotransplantation samples based on Gene Expression Omnibus database. Survival analysis was performed via the GEPIA database (GEO). The relationship between the key gene ITGAM and the therapeutic candidates was retrieved from DGIdb. A total of 1,302 differentially expressed genes were identified based on GEO. The PPI network highlighted 10 potential hub genes. Only ITGAM was linked to poor DSF in NSCLC patients. A total of 10 drugs were predicted to be potential therapeutics for NSCLC with EGFR-TKI resistance. This study indicates the hub genes related to EGFR-TKI resistance in NSCLC through bioinformatics technologies which can improve the understanding of the mechanisms of EGFR-TKI resistance and provide novel insights into therapeutics.

Prediction and validation of common targets in atherosclerosis and non-small cell lung cancer influenced by atorvastatin

BACKGROUND

Cardiovascular disease and cancer are the main causes of morbidity and mortality worldwide. Studies have shown that these two diseases may have some common risk factors. Atorvastatin is mainly used for the treatment of atherosclerosis in clinic. A large number of studies show that atorvastatin may produce anti-tumor activities. This study aimed to predict the common targets of atorvastatin against atherosclerosis and non-small cell lung cancer (NSCLC) based on network pharmacology.

METHODS

The target genes of atherosclerosis and NSCLC were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The disease-target-component model map and the core network were obtained using Cytoscape 3.7.1. The MTS and wound healing assay were used to detect the effect of atorvastatin on cell viability and migration of A549 cells. The expression of potential common target genes of atorvastatin against atherosclerosis and NSCLC were confirmed in A549 cells and lung cancer tissues of patients.

RESULTS

We identified 15 identical pathogenic genes, and four of which (MMP9, MMP12, CD36, and FABP4) were considered as the key target genes of atorvastatin in anti-atherosclerosis and NSCLC. The MTS and wound healing assays revealed that atorvastatin decreased A549 cells migration significantly. Atorvastatin markedly decreased the expression of MMP9, MMP12, CD36, and FABP4 in A549 cells and patients were treated with atorvastatin.

CONCLUSIONS

This study demonstrated 15 common pathogenic genes in both atherosclerosis and NSCLC. And verified that MMP 9, MMP 12, CD 36 and FABP 4 might be the common target genes of atorvastatin in anti-atherosclerosis and NSCLC.

Antitumor Effects of Ononin by Modulation of Apoptosis in Non-Small-Cell Lung Cancer through Inhibiting PI3K/Akt/mTOR Pathway

Lung cancer is a leading global cause of cancer-related death in both males and females. Non-small-cell lung cancer (NSCLC) is the most commonly diagnosed cancer type that can be difficult to control with conventional chemotherapeutic and surgical approaches resulting in a poor prognosis. Paclitaxel (PTX) is a commonly used chemotherapeutic drug for NSCLC, which can cause tissue injury in healthy cells and affect the quality of life in patients with cancer. In order to treat NSCLC, alternative medications with minimal or no side effects are highly needed. Ononin is an isoflavone glycoside extracted from Astragali Radix (AR) that has various pharmacological activities. Therefore, this study investigated whether ononin inhibits NSCLC progression and promotes apoptosis synergistically with PTX both in vitro and in vivo. Antitumorigenic properties of ononin were determined by MTT assay, colony formation assay, migratory capacity, and apoptotic marker expression in A549 and HCC827 cells. The combination of ononin with PTX increased the expression of apoptotic markers and ROS generation and inhibited cell proliferation through the PI3K/Akt/mTOR signaling pathways. Furthermore, ononin prevented the translocation of NF-κB from cytosol to the nucleus. Also, we used the xenograft NSCLC mice model to confirm the in vivo antitumorigenic efficacies of ononin by reduction of CD34 and Ki67 expressions. Based on the histological analysis, the cotreatment of PTX and ononin reduced PTX-induced liver and kidney damage. Overall, our findings suggested that the therapeutic index of PTX-based chemotherapy could be improved by reducing toxicity with increasing antitumor capabilities when combined with ononin.

The role of statins in lung cancer

Lung cancer is one of the most common causes of cancer-related mortality in the 21^st century. Statins as inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase not only reduce the cholesterol levels in the blood and decrease the risk of cardiovascular disease but may also play an important role in the prevention and treatment of lung cancer. Statins have several antitumor properties including the ability to reduce cell proliferation and angiogenesis, decrease invasion and synergistic suppression of lung cancer progression. Statins induce tumor cell apoptosis by inhibition of downstream products such as small GTP-binding proteins, Rho, Ras and Rac, which are dependent on isoprenylation. Statins reduce angiogenesis in tumors by down-regulation of pro-angiogenic factors, such as vascular endothelial growth factor. In this review, the feasibility and efficacy of statins in the prevention and treatment of lung cancer are discussed.

Integrated Transcriptomic Analysis Revealed Hub Genes and Pathways Involved in Sorafenib Resistance in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), a high mortality malignancy, has become a worldwide public health concern. Acquired resistance to the multikinase inhibitor sorafenib challenges its clinical efficacy and the survival benefits it provides to patients with advanced HCC. This study aimed to identify critical genes and pathways associated with sorafenib resistance in HCC using integrated bioinformatics analysis. Differentially expressed genes (DEGs) were identified using four HCC gene expression profiles (including 34 sorafenib-resistant and 29 sorafenib-sensitive samples) based on the robust rank aggregation method and R software. Gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool. A protein–protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING), and small molecules reversing sorafenib resistance were searched for using the connectivity map (CMAP) database. Pearson correlation and survival analyses of hub genes were performed using cBioPortal and Gene Expression Profiling and Interactive Analysis (GEPIA). Finally, the expression levels of hub genes in sorafenib-resistant HCC cells were verified using quantitative polymerase chain reaction (q-PCR). A total of 165 integrated DEGs (66 upregulated and 99 downregulated in sorafenib resistant samples compared sorafenib sensitive ones) primarily enriched in negative regulation of endopeptidase activity, extracellular exosome, and protease binding were identified. Some pathways were commonly shared between the integrated DEGs. Seven promising therapeutic agents and 13 hub genes were identified. These findings provide a strategy and theoretical basis for overcoming sorafenib resistance in HCC patients.

The potential of Atorvastatin for chronic lung diseases therapy

Atorvastatin (ATO) is of the statin class and is used as an orally administered lipid-lowering drug. ATO is a reversible synthetic competitive inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase thus leading to a reduction in cholesterol synthesis. It has recently been demonstrated that ATO has different pharmacological actions, which are unrelated to its lipid-lowering effects and has the ability to treat chronic airway diseases. This paper reviews the potential of ATO as an anti-inflammatory, antioxidant, and anti-proliferative agent after oral or inhaled administration. This paper discusses the advantages and disadvantages of using ATO under conditions associated with those found in the airways. This treatment could potentially be used to support the formulating of ATO as an inhaler for the treatment of chronic respiratory diseases.

A Prospective, Randomized, Placebo-Controlled Study of a Combination of Simvastatin and Chemotherapy in Metastatic Breast Cancer

Preclinical studies support the anticancer activity of statins; however, the existing clinical evidence is inconsistent and not definitive. Our study aimed at evaluating a postulated cancer chemo-sensitizing effect of statin (simvastatin) in a cohort of metastatic breast cancer (MBC) patients. We designed a prospective, single-centered, randomized, double blinded, placebo-controlled trial that encompassed MBC patients with an ECOG Performance Status Scale ≤2 and scheduled to be treated with a chemotherapy regimen consisting of carboplatin and vinorelbine every 3 weeks at Al-Baironi Hospital, Damascus, Syria. Patients were enrolled between August 2011 and July 2012 and randomly allocated to receive a 15-day course of either simvastatin (40 mg) or placebo seven days prior to the first day of each chemotherapy cycle and then continued for eight days in each individual cycle. Primary endpoints were objective response rate (ORR) and toxicity, and the secondary endpoint was overall survival (OS). Eighty-two patients met the inclusion criteria and consented. ORR (35% vs. 32.5%) and predominant toxicity and grade ≥3 neutropenia (occurred in 30% vs. 40% of the patients) were not significantly different between simvastatin and placebo groups, respectively. Over a median follow-up of 44 months (range, 10-60), median OS was 15 months in the simvastatin group and 17 the in placebo group (hazard ratio (HR) = 1.16, 95% CI (0.70-1.91), P=0.57). Elevated baseline values of high-sensitivity C-reactive protein (hsCRP >10 mg/l), lactate dehydrogenase (LDH >480 U/L), and chemotherapy being ≥2^nd line were significantly associated with shorter OS for the total cohort in both Univariate and multivariate analyses. Our data prove a safe profile of simvastatin at 40 mg per day combined with carboplatin and vinorelbine in MBC patients but without any beneficial increase of tumor sensitivity to chemotherapy. Moreover, we demonstrated a strong clinical advantage of baseline values of hsCRP and LDH as useful prognostic tools in MBC patients. This trial is registered with ISRCTN12964275.

Attenuation of the pro-inflammatory signature of lung cancer-derived mesenchymal stromal cells by statins

Solid tumor growth triggers a dynamic host response, which recapitulates wound healing and defines the tumor microenvironment (TME). In addition to the action of the tumor cells themselves, the TME is maintained by a myriad of immune and stromal cell-derived soluble mediators and extracellular matrix components whose combined action supports tumor progression. However, therapeutic targeting of the TME has proven challenging because of incomplete understanding of the tumor-host crosstalk at the molecular level. Here, we investigated the crosstalk between mesenchymal stromal cells (MSCs) and primary cancer cells (PCCs) from human squamous cell lung carcinoma (SCC). We discovered that PCCs secrete CCL3 and stimulate IL-6, CCL2, ICAM-1 and VCAM-1 expression in MSCs and that the MSC-PCC crosstalk can be disrupted by the lipid-lowering drug simvastatin, which displays pleiotropic effects on cell metabolism and suppresses IL-6 and CCL2 production by MSCs and CCL3 secretion by PCCs. In addition, simvastatin inhibited spheroid formation by PCCs and negatively affected PCC survival. Our observations demonstrate that commonly used statins may be repurposed to target the TME in lung carcinoma.

Luteolin inhibits proliferation and induces apoptosis of human melanoma cells in vivo and in vitro by suppressing MMP-2 and MMP-9 through the PI3K/AKT pathway

Since the incidence rate of malignant melanoma is increasing annually, development of drugs against melanoma cell metastasis has become more urgent. Luteolin, a naturally occurring flavonoid, is abundant in our daily dietary intake and exhibits a wide spectrum of pharmacological properties. However, the potential anti-cancer role of luteolin in melanoma cells has not been fully investigated. In this study, we have explored whether luteolin inhibits the migration and invasion of A375 human melanoma cells and further elucidated the underlying anti-cancer molecular mechanism of luteolin in melanoma cells. A proliferation assay, flow cytometry and an apoptosis assay were applied to detect the effect of luteolin on the growth and apoptosis of A375 cells. Wound healing assay and transwell invasion assay were used to explore the impact of luteolin on the migration and invasion of A375 cells. Real-time quantitative PCR, western blot and immunofluorescence analysis were used to investigate the effects of luteolin on the expressions of MMP-2, MMP-9 and PI3K/AKT1 in A375 cells. A xenograft tumor animal model was used to investigate the anti-cancer effect of luteolin on the growth of the A375 cells in vivo. Our data indicated that luteolin significantly inhibited the proliferation, migration and invasion of A375 cells and induced the apoptosis of A375 cells in a concentration-dependent manner. Moreover, luteolin reduced the expressions of MMP-2 and MMP-9 and increased the expression of TIMP-1 and TIMP-2. Furthermore, luteolin significantly inhibited the tumor growth of A375 cells in a xenograft mouse model. The immunofluorescence and immunoblotting assays indicated that luteolin inhibited the phosphorylation of AKT1 and PI3K. In conclusion, both in vivo and in vitro studies showed that luteolin inhibited the proliferation and induced the apoptosis of A375 human melanoma cells by reducing the expressions of MMP-2 and MMP-9 through the PI3K/AKT pathway. Overall, luteolin can be considered as a promising anti-cancer agent for the treatment of human melanoma.

Statin use and prognosis of lung cancer: a systematic review and meta-analysis of observational studies and randomized controlled trials

Background

Previous clinical studies reported inconsistent results on the associations of statins with the mortality and survival of lung cancer patients. This review and meta-analysis summarized the impact of statins on mortality and survival of lung cancer patients.

Materials and methods

Eligible papers of this meta-analysis were searched by using PubMed, EMBASE, and Cochrane until July 2017. Primary end points were the mortality (all-cause mortality and cancer-specific mortality) and survival (progression-free survival and overall survival) of patients with statin use. Secondary end points were overall response rate and safety. The random-effects model was used to calculate pooled HRs and 95% CIs.

Results

Seventeen studies involving 98,445 patients were included in the meta-analysis. In observational studies, the pooled HR indicated that statins potentially decreased the cancer-specific mortality and promoted the overall survival of lung cancer patients. Statins showed an association with decreased all-cause mortality in cohort studies (HR =0.77, 95% CI: 0.59–0.99), but not in case-control studies (HR =0.75, 95% CI: 0.50–1.10). However, statin use showed no impact on mortality and overall survival in randomized controlled trials. Meanwhile, this meta-analysis indicated that statin use did not affect the progression-free survival of lung cancer patients in observational studies and randomized controlled trials. In addition, statins potentially enhanced the effects of tyrosine kinase inhibitors (HR=0.86, 95% CI: 0.76–0.98) and chemotherapy (HR=0.86, 95% CI: 0.81–0.91) on the overall survival of patients with non-small-cell lung cancer, but did not increase overall response rate and toxicity.

Conclusion

Statins were potentially associated with the decreasing risk of mortality and the improvement of overall survival in observational studies but not in randomized controlled trials.

Perturbing the Dynamics and Organization of Cell Membrane Components: A New Paradigm for Cancer-Targeted Therapies

Cancer is a multi-process disease where different mechanisms exist in parallel to ensure cell survival and constant adaptation to the extracellular environment. To adapt rapidly, cancer cells re-arrange their plasma membranes to sustain proliferation, avoid apoptosis and resist anticancer drugs. In this review, we discuss novel approaches based on the modifications and manipulations that new classes of molecules can exert in the plasma membrane lateral organization and order of cancer cells, affecting growth factor signaling, invasiveness, and drug resistance. Furthermore, we present azurin, an anticancer protein from bacterial origin, as a new approach in the development of therapeutic strategies that target the cell membrane to improve the existing standard therapies.

Beneficial effect of additional treatment with widely available anticancer agents in advanced small lung cell carcinoma: A case report

Small-cell lung carcinoma is a type of lung cancer characterized by very poor prognosis, as the majority of the patients have already developed metastases at initial diagnosis. Small-cell lung cancer accounts for ~15% of all lung cancer cases. The present study reports the case of a female patient with advanced-stage small-cell lung cancer. The patient received the standard treatments (6 cycles of platinum and etoposide chemotherapy followed by Gamma Knife treatment of suspicious mediastinal lymphnodes); in addition, naturally derived agents (curcumin, parthenolide, betuline, sulforaphane, withanolides, lactoferrin, pomegranate fruit extract, flaxseed and dioscorea) were alternately administered at increased doses, while previously prescribed medications for other comorbidities (metformin and atorvastatin) were continued. Complete regression of the tumour was observed, and the patient remains in full remission and cancer-free for >7 years. Moreover, no treatment-related side effects and no drug interactions were observed.

The Effect of Statin Added to Systemic Anticancer Therapy: A Meta-Analysis of Randomized, Controlled Trials

Preclinical studies have demonstrated that statins have anticancer properties and act in an additive or synergistic way when combined with anticancer therapy. We conducted this meta-analysis of randomized, controlled phase II or III trials to evaluate the effect of statins added to systemic anticancer therapy in patients with solid cancer. A systematic literature search was performed to identify all randomized trials that were designed to investigate the effect of statins in patients with cancer using PubMed, EMBASE, Google Scholar, and Web of Science (up to August 2018). From eight randomized controlled trials, 1760 patients were included in the pooled analyses of odds ratios (ORs) with 95% confidence intervals (CIs) for grade 3–5 adverse events (AEs) and overall response rate (ORR) and hazard ratios (HRs) with 95% CIs for progression-free survival (PFS) and overall survival (OS). The addition of statin to anticancer agents did not significantly increase the incidence of grade 3–5 AEs (OR = 1.03, 95% CI: 0.81–1.29, p = 0.78). However, the combination of statin and anticancer agents did not improve ORR (OR = 0.96, 95% CI: 0.77–1.20, p = 0.72) compared with that of anticancer therapy alone. In addition, statins added to systemic anticancer therapy failed to prolong PFS (HR = 0.99, 95% CI: 0.90–1.10, p = 0.92) and OS (HR = 0.91, 95% CI: 0.76–1.11, p = 0.52). In conclusion, this meta-analysis of randomized controlled trials does not support clinical benefits of statins added to systemic anticancer therapy in patients with solid cancer.

The Anti-Angiogenic Effect of Atorvastatin in Glioblastoma Spheroids Tumor Cultured in Fibrin Gel: in 3D in Vitro Model

Purpose:

Glioblastoma multiform (GBM) is the most aggressive glial neoplasm. Researchers have exploited the fact that GBMs are highly vascularized tumors. Anti-angiogenic strategies including those targeting VEGF pathway have been emerged for treatment of GBM. Previously, we reported the anti-inflammatory effect of atorvastatin on GBM cells. In this study, we investigated the anti-angiogenesis and apoptotic activity of atorvastatin on GBM cells.

Methods:

Different concentrations of atorvastatin (1, 5, 10µM) were used on engineered three-dimensional (3D) human tumor models using glioma spheroids and Human Umbilical Vein Endothelial cells (HUVECs) in fibrin gel as tumor models. To reach for these aims, angiogenesis as tube-like structures sprouting of HUVECs were observed after 24 hour treatment with different concentrations of atorvastatin into the 3-D fibrin matrix and we focused on it by angiogenesis antibody array. After 48 hours exposing with different concentrations of atorvastatin, cell migration of HUVECs were investigated. After 24 and 48 hours exposing with different concentrations of atorvastatin VEGF, CD31, caspase-3 and Bcl-2 genes expression by real time PCR were assayed.

Results:

The results showed that atorvastatin has potent anti-angiogenic effect and apoptosis inducing effect against glioma spheroids. Atorvastatin down-regulated the expression of VEGF, CD31 and Bcl-2, and induced the expression of caspase-3 especially at 10µM concentration. These effects are dose dependent.

Conclusion:

These results suggest that this biomimetic model with fibrin may provide a vastly applicable 3D culture system to study the effect of anti-cancer drugs such as atorvastatin on tumor malignancy in vitro and in vivo and atorvastatin could be used as agent for glioblastoma treatment.

Expression of the Hippo signalling effectors YAP and TAZ in canine mammary gland hyperplasia and malignant transformation of mammary tumours

Canine mammary tumours (CMTs) are common neoplasms in dogs that feature many of the clinical, genetic and molecular characteristics of human breast cancer. Despite their high metastatic potential, few adjuvant chemotherapeutic treatment options exist for malignant CMTs, and the development of novel, targeted pharmacological approaches will require a better understanding of their pathogenesis. As recent evidence suggests that dysregulated Hippo signalling is involved in the development and progression of breast cancer, we sought to determine if this pathway could also play a role in CMT. The expression of the Hippo signalling effectors YAP and TAZ was analysed by immunoblotting and immunohistochemistry in samples including normal mammary gland, lobular hyperplasia, benign tumours and malignant tumours of all grades. We found a significant increase in TAZ (but not YAP) expression occurred in lobular hyperplasia relative to normal mammary gland, suggesting a role for TAZ in non-neoplastic epithelial proliferation. Nuclear expression of both TAZ and YAP were significantly higher in malignant tumours than in benign ones, suggesting that Hippo dysregulation could play a role in CMT malignant transformation. No differences in YAP or TAZ expression were detected between grades of malignant tumours. Together, our results indicate that alterations in Hippo signalling may play a role in the pathogenesis of CMT, in a manner similar to breast cancer. Hippo pathway components may therefore represent targets for the development of novel chemotherapeutic agents that could be useful for the treatment of both the human and canine diseases.

Multicenter, Phase III, Randomized, Double-Blind, Placebo-Controlled Trial of Pravastatin Added to First-Line Standard Chemotherapy in Small-Cell Lung Cancer (LUNGSTAR)

Purpose Treating small-cell lung cancer (SCLC) remains a therapeutic challenge. Experimental studies show that statins exert additive effects with agents, such as cisplatin, to impair tumor growth, and observational studies suggest that statins combined with anticancer therapies delay relapse and prolong life in several cancer types. To our knowledge, we report the first large, randomized, placebo-controlled, double-blind trial of a statin with standard-of-care for patients with cancer, specifically SCLC. Patients and Methods Patients with confirmed SCLC (limited or extensive disease) and performance status 0 to 3 were randomly assigned to receive daily pravastatin 40 mg or placebo, combined with up to six cycles of etoposide plus cisplatin or carboplatin every 3 weeks, until disease progression or intolerable toxicity. Primary end point was overall survival (OS), and secondary end points were progression-free survival (PFS), response rate, and toxicity. Results Eight hundred forty-six patients from 91 United Kingdom hospitals were recruited. The median age of recruited patients was 64 years of age, 43% had limited disease, and 57% had extensive disease. There were 758 deaths and 787 PFS events. No benefit was found for pravastatin, either in all patients or in several subgroups. For pravastatin versus placebo, the 2-year OS rate was 13.2% (95% CI, 10.0 to 16.7) versus 14.1% (95% CI, 10.9 to 17.7), respectively, with a hazard ratio of 1.01 (95% CI, 0.88 to 1.16; P = .90. The median OS was 10.7 months v 10.6 months, respectively. The median PFS was 7.7 months v 7.3 months, respectively. The median OS (pravastatin v placebo) was 14.6 months in both groups for limited disease and 9.1 months versus 8.8 months, respectively, for extensive disease. Adverse events were similar between groups. Conclusion Pravastatin 40 mg combined with standard SCLC therapy, although safe, does not benefit patients. Our conclusions are the same as those found in all four much smaller, randomized, placebo-controlled trials specifically designed to evaluate statin therapy in patients with cancer.

Synergistic chemopreventive effects of nobiletin and atorvastatin on colon carcinogenesis

Different cancer chemopreventive agents may act synergistically and their combination may produce enhanced protective effects against carcinogenesis than each individual agent alone. Herein, we investigated the chemopreventive effects of nobiletin (NBT, a citrus polymethoxyflavone) and atorvastatin (ATST, a lipid-lowering drug) in colon cancer cells/macrophages and an azoxymethane (AOM)-induced colon carcinogenesis rat model. The results demonstrated that co-treatments of NBT/ATST produced enhanced growth inhibitory and anti-inflammatory effects on the colon cancer cells and macrophages, respectively. Isobologram analysis confirmed that these interactions between NBT and ATST were synergistic. NBT/ATST co-treatment also synergistically induced extensive cell cycle arrest and apoptosis in colon cancer cells. Oral administration of NBT (0.1%, w/w in diet) or ATST (0.04%, w/w in diet) significantly decreased colonic tumor incidence and multiplicity in AOM-treated rats. Most importantly, co-treatment of NBT/ATST at their half doses (0.05% NBT + 0.02% ATST, w/w in diet) resulted in even stronger inhibitory effects on colonic tumor incidence and multiplicity than did NBT or ATST alone at higher doses. Statistical analysis confirmed that the enhanced chemopreventive activities against colon carcinogenesis in rats by the NBT/ATST combination were highly synergistic. Our results further demonstrated that NBT/ATST co-treatment profoundly modulated key cellular signaling regulators associated with inflammation, cell proliferation, cell cycle progression, apoptosis, angiogenesis and metastasis in the colon of AOM-treated rats. In conclusion, for the first time, our results demonstrated a strong synergy in inhibiting colon carcinogenesis produced by the co-treatment of NBT and ATST, which provided a scientific basis for using NBT in combination with ATST for colon cancer chemoprevention in humans.

Therapeutic Effects of Repurposed Therapies in Non-Small Cell Lung Cancer: What Is Old Is New Again

The recent emergence of targeted and immunotherapeutic agents has dramatically changed the management for patients with non-small cell lung cancer (NSCLC). Despite these advances, lung cancer is not exempt from the challenges facing oncology drug development, including the huge financial cost and the time required for drug implementation. Repositioning noncancer therapies with potential antineoplastic properties into new therapeutic niches is an alternative treatment strategy offering the possibility of saving money and time and improving outcomes. The goal of such a strategy is to deliver an effective drug with a favorable toxicity profile at a reduced cost. Preclinical models and observational data have demonstrated promising activity for many of these agents, and they are now being studied in prospective trials. We review the relevant published data regarding the therapeutic effects of metformin, statins, nonsteroidal anti-inflammatory drugs, β-blockers, and itraconazole in NSCLC, with a focus on the putative mechanisms of action and clinical data. As these drugs are increasingly being tested in clinical trials, we aim to highlight the salient challenges and future strategies to optimize this approach.

Cecropin suppresses human hepatocellular carcinoma BEL- 7402 cell growth and survival in vivo without side-toxicity

Conventional chemotherapy against hepatocellular carcinoma typically causes various side effects. Our previous study showed that cecropin of Musca domestica can induce apoptosis in human hepatocellular carcinoma BEL-7402 cells in vitro. However, whether cecropin inhibits BEL-7402 cell in vivo and the question of possible side effects remained undentified. The present study confirmed tumor-inhibitory effects of cecropin in vivo, and furthermore strongly suggested that cecropin cytotoxicity in BEL-7402 cells in vivo may be mainly derived from its pro-apoptotic action. Specifically, we found that cecropin exerted no obvious side effects in tumor-bearing mice as it had no significant hematoxicity as well as visceral toxicity. Therefore, cecropin may be a potential candidate for further investigation as an antitumor agent against hepatocellular carcinoma.

Dasatinib enhances cisplatin sensitivity in human esophageal squamous cell carcinoma (ESCC) cells via suppression of PI3K/AKT and Stat3 pathways

The clinical efficacy of cisplatin in esophageal squamous cell carcinoma (ESCC) treatment remains undesirable. Src, a non-receptor tyrosine kinase involved in multiple fields of tumorigenesis, recently has been indicated as a promising therapeutic target in the treatment of solid tumors including ESCC. However, whether inhibition of Src activity can increase cisplatin efficacy in ESCC cells remains unknown. The present study found that inhibition of Src by its inhibitor-dasatinib sensitized ESCC cells to cisplatin in vitro. Our data also suggest a likely mechanism for this synergy that dasatinib reduces expression of critical oncogenic members of the signaling pathways, such as AKT or Stat3, and cisplatin-resistant molecules, such as ERCC1 and BRCA1, under the control of Src. Furthermore, dasatinib could sensitize ESCC cells to another platin-based agent, carboplatin. Therefore, this study provides a potential target for improving cisplatin efficacy in ESCC therapy.

Enoxaparin sensitizes human non-small-cell lung carcinomas to gefitinib by inhibiting DOCK1 expression, vimentin phosphorylation, and Akt activation

Gefitinib is widely used for the treatment of lung cancer in patients with sensitizing epidermal growth factor receptor mutations, but patients tend to develop resistance after an average of 10 months. Low molecular weight heparins, such as enoxaparin, potently inhibit experimental metastasis. This study aimed to determine the potential of combined enoxaparin and gefitinib (enoxaparin + gefitinib) treatment to inhibit tumor resistance to gefitinib both in vitro and in vivo. A549 and H1975 cell migration was analyzed in wound closure and Transwell assays. Akt and extracellular signal-related kinase 1/2 signaling pathways were identified, and a proteomics analysis was conducted using SDS-PAGE/liquid chromatography-tandem mass spectrometry analysis. Molecular interaction networks were visualized using the Cytoscape bioinformatics platform. Protein expression of dedicator of cytokinesis 1 (DOCK1) and cytoskeleton intermediate filament vimentin were identified using an enzyme-linked immunosorbent assay, Western blot, and small interfering RNA transfection of A549 cells. In xenograft A549-luc-C8 tumors in nude mice, enoxaparin + gefitinib inhibited tumor growth and reduced lung colony formation compared with gefitinib alone. Furthermore, the combination had stronger inhibitory effects on cell migration than either agent used individually. Additional enoxaparin administration resulted in better effective inhibition of Akt activity compared with gefitinib alone. Proteomics and network analysis implicated DOCK1 as the key node molecule. Western blot verified the effective inhibition of the expression of DOCK1 and vimentin phosphorylation by enoxaparin + gefitinib compared with gefitinib alone. DOCK1 knockdown confirmed its role in cell migration, Akt expression, and vimentin phosphorylation. Our data indicate that enoxaparin sensitizes gefitinib antitumor and antimigration activity in lung cancer by suppressing DOCK1 expression, Akt activity, and vimentin phosphorylation.

c-Met targeting enhances the effect of irradiation and chemical agents against malignant colon cells harboring a KRAS mutation

Although EGFR-targeted therapy has been beneficial to colorectal cancer patients, several studies have showed this clinical benefit was restricted to patients with wild-type KRAS exon 2 colorectal cancer. Therefore, it is crucial to explore efficient treatment strategies in patients with KRAS mutations. c-Met is an emerging target for the development of therapeutics against colorectal cancer. In this study, we first used the SW620 cell line, which has an activating KRAS mutation, to generate a stable cell line with conditional regulation of c-Met, which is an essential gene for growth and an oncogene. Using this approach, we evaluated the benefits of combined c-Met-targeted therapy with irradiation or chemical agents. In this cell line, we observed that the proliferation and migration of SW620 cells were reduced by the induction of c-Met shRNA. Furthermore, c-Met knockdown enhanced the anti-proliferative effects of 5-FU and Taxol but not cisplatin, irinotecan or sorafenib. These enhancements were also observed in another colon cancer cells line HCT-116, which also has a KRAS mutation. The response of SW620 cells to irradiation was also enhanced by c-Met knockdown. This method and obtained data might have important implications for exploring the combinatory effects of targeted therapies with conventional medications. Moreover, the data suggested that the combination of c-Met-targeted therapy with chemotherapy or irradiation might be an effective strategy against colorectal cancer harboring a KRAS mutation.

Oxysterols synergize with statins by inhibiting SREBP-2 in ovarian cancer cells

OBJECTIVE

Determine mechanisms responsible for enhanced statin efficacy in a novel statin combination we name STOX (STatin-OXysterol).

METHODS

Ovarian cancer cell lines were treated with combinations of statins and oxysterols. Cell viability was determined by a modified MTT assay. Apoptosis was evaluated by immunoblotting of PARP and DAPI-mediated visualization of apoptotic nuclei. STOX effects on the expression of genes of the mevalonate pathway were assessed by real-time qPCR and immunoblotting. siRNA-mediated gene silencing was used to test the involvement of oxysterol-mediated repression of SREBP-2 in STOX synergy. The impact of statin-mediated inhibition of protein prenylation and on cholesterol homeostasis was evaluated.

RESULTS

Oxysterols dramatically enhance cytotoxicity of statins in ovarian cancer cells through increased apoptosis. Decreased expression of SREBP-2 down-regulates the mevalonate pathway and prevents the active statin-induced sterol feedback, enhancing statin toxicity. Comparison of two ovarian cancer cell lines reveals two distinct mechanisms of statin induced toxicity, namely, dependence on protein geranylgeranylation and/or perturbation of cellular cholesterol levels.

CONCLUSIONS

We provide evidence of statins' mechanisms of cytotoxicity in different ovarian cancer cells and discovered a new approach to significantly enhance the anti-tumor activity of statins. These observations provide a potential new path to improve statins as a treatment against ovarian cancer with obtainable dosages.

Novel prospects of statins as therapeutic agents in cancer

Statins are well known competitive inhibitors of hydroxymethylglutaryl-CoA reductase enzyme (HMG-CoA reductase), thus traditionally used as cholesterol-lowering agents. In recent years, more and more effects of statins have been revealed. Nowadays alterations of lipid metabolism have been increasingly recognized as a hallmark of cancer cells. Consequently, much attention has been directed toward the potential of statins as therapeutic agents in the oncological field. Accumulated in vitro and in vivo clinical evidence point out the role of statins in a variety of human malignancies, in regulating tumor cell growth and anti-tumor immune response. Herein, we summarize and discuss, in light of the most recent observations, the anti-tumor effects of statins, underpinning the detailed mode of action and looking for their true significance in cancer prevention and treatment, to determine if and in which case statin repositioning could be really justified for neoplastic diseases.

HtrA1 downregulation induces cisplatin resistance in lung adenocarcinoma by promoting cancer stem cell-like properties

Cisplatin (CDDP) resistance usually develops during lung adenocarcinoma (LAC) therapy. However, the comprehensive mechanisms remain largely unclear. In this study, we first established a CDDP-resistant LAC cell line-A549/CDDP from its parental cell line-A549. The results showed that CDDP resistance in A549/CDDP cells correlates with acquirement of cancer stem cell-like properties (increased percentage of CD133-expressing subpopulation, sphere formation and levels of some pluripotency-associated markers). HtrA1 expression at both mRNA and protein levels was reduced in CDDP-resistant A549/CDDP cells compared with that in A549 cells. Ectopic expression of HtrA1 in A549/CDDP cells reversed cancer stem cell-like properties and CDDP resistance. In A549 cells, stable knockdown of HtrA1 expression promoted cancer stem cell-like properties and CDDP insensitivity, however, these effects were blocked by inhibition of PI3K/Akt pathway using LY294002. Furthermore, HtrA1 knockdown could significantly stimulate PI3K/Akt signaling in A549 cells. In vivo studies, HtrA1 knockdown promoted tumorigenesis and conferred CDDP resistance in xenograft A549 tumors, which were reversed by intraperitoneal injection of LY294002. In conclusion, these results indicate that HtrA1 downregulation confers CDDP resistance by inducing cancer stem cell-like properties via PI3K/Akt-dependent pathway in A549 cells. Therefore, HtrA1 may be a potential target for overcoming CDDP resistance in LAC.

Atorvastatin overcomes gefitinib resistance in KRAS mutant human non-small cell lung carcinoma cells

The exact influence of statins on gefitinib resistance in human non-small cell lung cancer (NSCLC) cells with KRAS mutation alone or KRAS/PIK3CA and KRAS/PTEN comutations remains unclear. This work found that transfection of mutant KRAS plasmids significantly suppressed the gefitinib cytotoxicity in Calu3 cells (wild-type KRAS). Gefitinib disrupted the Kras/PI3K and Kras/Raf complexes in Calu3 cells, whereas not in Calu3 KRAS mutant cells. These trends were corresponding to the expression of pAKT and pERK in gefitinib treatment. Atorvastatin (1 μM) plus gefitinib treatment inhibited proliferation, promoted cell apoptosis, and reduced the AKT activity in KRAS mutant NSCLC cells compared with gefitinib alone. Atorvastatin (5 μM) further enhanced the gefitinib cytotoxicity through concomitant inhibition of AKT and ERK activity. Atorvastatin could interrupt Kras/PI3K and Kras/Raf complexes, leading to suppression of AKT and ERK activity. Similar results were also obtained in comutant KRAS/PTEN or KRAS/PIK3CA NSCLC cells. Furthermore, mevalonate administration reversed the effects of atorvastatin on the Kras/Raf and Kras/PI3K complexes, as well as AKT and ERK activity in both A549 and Calu1 cells. The in vivo results were similar to those obtained in vitro. Therefore, mutant KRAS-mediated gefitinib insensitivity is mainly derived from failure to disrupt the Kras/Raf and Kras/PI3K complexes in KRAS mutant NSCLC cells. Atorvastatin overcomes gefitinib resistance in KRAS mutant NSCLC cells irrespective of PIK3CA and PTEN statuses through inhibition of HMG-CoA reductase-dependent disruption of the Kras/Raf and Kras/PI3K complexes.