Frequent activation of AKT2 and induction of apoptosis by inhibition of phosphoinositide-3-OH kinase/Akt pathway in human ovarian cancer

Targeting Ion Channels: Blockers Suppress Calcium Signals and Induce Cytotoxicity Across Medulloblastoma Cell Models

Medulloblastoma (MB) groups 3 and 4 lack targeted therapies despite their dismal prognoses. Ion channels and pumps have been implicated in promoting MB metastasis and growth; however, their roles remain poorly understood. In this study, we repurposed FDA-approved channel blockers and modulators to investigate their potential anti-tumor effects in MB cell lines (DAOY and D283) and primary cell cultures derived from a patient with MB. For the first time, we report spontaneous calcium signaling in MB cells. Spontaneous calcium signals were significantly reduced by mibefradil (calcium channel blocker), paxilline (calcium-activated potassium channel blocker), and thioridazine (potassium channel blocker). These drugs induced dose-dependent cytotoxicity in both the DAOY and D283 cell lines, as well as in primary cell cultures of a patient with group 3 or 4 MB. In contrast, digoxin and ouabain, inhibitors of the Na/K pump, reduced the calcium signaling by over 90% in DAOY cells and induced approximately 90% cell death in DAOY cells and 80% cell death in D283 cells. However, these effects were significantly diminished in the cells derived from a patient with MB, highlighting the variability in drug sensitivity among MB models. These findings demonstrate that calcium signaling is critical for MB cell survival and that the targeted inhibition of calcium pathways suppresses tumor cell growth across multiple MB models.

Functional genomic imaging (FGI), a virtual tool for visualization of functional gene expression modules in heterogeneous tumor samples

Advances in sequencing technologies are reshaping clinical diagnostics, prompting the development of new software tools to decipher big data. To this end, we developed functional genomic imaging (FGI), a visualization tool designed to assist clinicians in interpreting RNA-Seq results from patient samples. FGI uses weighted gene co-expression network analysis (WGCNA), followed by a modified Phenograph clustering algorithm to identify co-expression gene clusters. These gene modules were annotated and projected onto a t-SNE map for visualization. Annotation of FGI gene clusters revealed three categories: tissue-specific, functional, and positional. These clusters may be used to build tumor subtypes with pre-annotated functions. At the multi-cancer cohort level, tissue-specific clusters are enriched, whereas at the single cancer level, such as in lung cancer or ovarian cancer, positional clusters can be more prominent. Moreover, FGI analysis could also reveal molecular tumor subtypes not documented in clinical records and generated a more detailed co-expression gene cluster map. Based on different levels of FGI modeling, each individual tumor sample can be customized to display various types of information such as tissue origin, molecular subtypes, immune activation status, stromal signaling pathways, cell cycle activity, and potential amplicon regions which can aid in diagnosis and guide treatment decisions. Our results highlight the potential of FGI as a robust visualization tool for personalized medicine in molecular diagnosis.

Potential of Natural Products in the Treatment of Glioma: Focus on Molecular Mechanisms

Despite the waning of traditional treatments for glioma due to possible long-term issues, the healing possibilities of substances derived from nature have been reignited in the scientific community. These natural substances, commonly found in fruits and vegetables, are considered potential alternatives to pharmaceuticals, as they have been shown in prior research to impact pathways surrounding cancer progression, metastases, invasion, and resistance. This review will explore the supposed molecular mechanisms of different natural components, such as berberine, curcumin, coffee, resveratrol, epigallocatechin-3-gallate, quercetin, tanshinone, silymarin, coumarin, and lycopene, concerning glioma treatment. While the benefits of a balanced diet containing these compounds are widely recognized, there is considerable scope for investigating the efficacy of these natural products in treating glioma.

CRLF1 bridges AKT and mTORC2 through SIN1 to inhibit pyroptosis and enhance chemo-resistance in ovarian cancer

Ovarian cancer, the second most leading cause of gynecologic cancer mortality worldwide, is challenged by chemotherapy resistance, presenting a significant hurdle. Pyroptosis, an inflammation-linked programmed cell death mediated by gasdermins, has been shown to impact chemoresistance when dysregulated. However, the mechanisms connecting pyroptosis to chemotherapy resistance in ovarian cancer are unclear. We found that cytokine receptor-like factor 1 (CRLF1) is a novel component of mTORC2, enhancing AKT Ser473 phosphorylation through strengthening the interaction between AKT and stress-activated protein kinase interacting protein 1 (SIN1), which in turn inhibits the mitogen-activated protein kinase kinase kinase 5 (ASK1)-JNK-caspase-3-gasdermin E pyroptotic pathway and ultimately confers chemoresistance. High CRLF1-expressing tumors showed sensitivity to AKT inhibition but tolerance to cisplatin. Remarkably, overexpression of binding-defective CRLF1 variants impaired AKT-SIN1 interaction, promoting pyroptosis and chemosensitization. Thus, CRLF1 critically regulates chemoresistance in ovarian cancer by modulating AKT/SIN1-dependent pyroptosis. Binding-defective CRLF1 variants could be developed as tumor-specific polypeptide drugs to enhance chemotherapy for ovarian cancer.

Cross-species analysis of transcriptome emphasizes a critical role of TNF-α in mediating MAP2K7/AKT2 signaling in zearalenone-induced apoptosis

Zearalenone (ZEN) is a widespread and transgenerational toxicant that can cause serious reproductive health risks, which poses a potential threat to global agricultural production and human health; its estrogenic activity can lead to reproductive toxicity through the induction of granulosa cell apoptosis. Herein, comparative transcriptome analysis, single-cell transcriptome analysis, and weighted gene co-expression network analysis (WGCNA) combined with gene knockout in vivo and RNA interference in vitro were used to comprehensively describe the damage caused by ZEN exposure on ovarian granulosa cells. Comparative transcriptome analysis and WGCNA suggested that the tumor necrosis factor (TNF)-α-mediated mitogen-activated protein kinase 7 (MAP2K7)/ AKT serine/threonine kinase 2 (AKT2) axis was disordered after ZEN exposure in porcine granulosa cells (pGCs) and mouse granulosa cells (mGCs). In vivo gene knockout and in vitro RNA interference verified that TNF-α-mediated MAP2K7/AKT2 was the guiding signal in ZEN-induced apoptosis in pGCs and mGCs. Moreover, single-cell transcriptome analysis showed that ZEN exposure could induce changes in the TNF signaling pathway in offspring. Overall, we concluded that the TNF-α-mediated MAP2K7/AKT2 axis was the main signaling pathway of ZEN-induced apoptosis in pGCs and mGCs. This work provides new insights into the mechanism of ZEN toxicity and provides new potential therapeutic targets for the loss of livestock and human reproductive health caused by ZEN.

Discovery and Characterization of PROTACs Targeting Tissue Transglutaminase (TG2)

Tissue transglutaminase (TG2) is a multifunctional enzyme involved in the cross-linking of extracellular matrix proteins, formation of complexes with fibronectin (FN) and integrins, and GTP hydrolysis. TG2 is activated in several pathological conditions, including cancer. We recently described a novel series of ligands that bind to TG2 and inhibit its interaction with FN. Because TG2 acts via multiple mechanisms, we set out to pursue a targeted protein degradation strategy to abolish TG2's myriad functions. Here, we report the synthesis and characterization of a series of VHL-based degraders that reduce TG2 in ovarian cancer cells in a proteasome-dependent manner. Degradation of TG2 resulted in significantly reduced cancer cell adhesion and migration in vitro in scratch-wound and migration assays. These results strongly indicate that further development of more potent and in vivo efficient TG2 degraders could be a new strategy for reducing the dissemination of ovarian and other cancers.

Investigation of cytotoxic and apoptotic effects of disodium pentaborate decahydrate on ovarian cancer cells and assessment of gene profiling

After revealing the anti-cancer properties of boron, which is included in the category of essential elements for human health by the World Health Organization, the therapeutic potential of boron compounds has been begun to be evaluated, and its molecular effect mechanisms have still been among the research subjects. In ovarian cancer, mutations or amplifications frequently occur in the PI3K/Akt/mTOR pathway components, and dysregulation of this pathway is shown among the causes of treatment failure. In the present study, it was aimed to investigate the anti-cancer properties of boron-containing DPD in SKOV3 cells, which is an epithelial ovarian cancer model, through PI3K/AKT/mTOR pathway. The cytotoxic activity of DPD in SKOV3 cells was evaluated by WST-1 test, apoptotic effect by Annexin V and JC-1 test. The gene expressions associated with PI3K/AKT/mTOR pathway were determined by real-time qRT-PCR. In SKOV3 cells, the IC₅₀ value of DPD was found to be 6.7 mM, 5.6 mM, and 5.2 mM at 24th, 48th and 72nd hour, respectively. Compared with the untreated control group, DPD treatment was found to induce apoptosis 2.6-fold and increase mitochondrial membrane depolarization 4.5-fold. DPD treatment was found to downregulate PIK3CA, PIK3CG, AKT2, IGF1, IRS1, MAPK3, HIF-1, VEGFC, CAB39, CAB39L, STRADB, PRKAB2, PRKAG3, TELO2, RICTOR, MLST8, and EIF4B genes and upregulate TP53, GSK3B, FKBP8, TSC2, ULK1, and ULK2 genes. These results draw attention to the therapeutic potential of DPD, which is frequently exposed in daily life, in epithelial ovarian cancer and show that it can be a candidate compound in combination with chemotherapeutics.

The Outside-In Journey of Tissue Transglutaminase in Cancer

Tissue transglutaminase (TG2) is a member of the transglutaminase family that catalyzes Ca²⁺-dependent protein crosslinks and hydrolyzes guanosine 5′-triphosphate (GTP). The conformation and functions of TG2 are regulated by Ca²⁺ and GTP levels; the TG2 enzymatically active open conformation is modulated by high Ca²⁺ concentrations, while high intracellular GTP promotes the closed conformation, with inhibition of the TG-ase activity. TG2’s unique characteristics and its ubiquitous distribution in the intracellular compartment, coupled with its secretion in the extracellular matrix, contribute to modulate the functions of the protein. Its aberrant expression has been observed in several cancer types where it was linked to metastatic progression, resistance to chemotherapy, stemness, and worse clinical outcomes. The N-terminal domain of TG2 binds to the 42 kDa gelatin-binding domain of fibronectin with high affinity, facilitating the formation of a complex with β-integrins, essential for cellular adhesion to the matrix. This mechanism allows TG2 to interact with key matrix proteins and to regulate epithelial to mesenchymal transition and stemness. Here, we highlight the current knowledge on TG2 involvement in cancer, focusing on its roles translating extracellular cues into activation of oncogenic programs. Improved understanding of these mechanisms could lead to new therapeutic strategies targeting this multi-functional protein.

Network medicine in ovarian cancer: topological properties to drug discovery

Network medicine provides network theoretical tools, methods and properties to study underlying laws governing human interactome to identify disease states and disease complexity leading to drug discovery. Within this framework, we investigated the topological properties of ovarian cancer network (OCN) and the roles of hubs to understand OCN organization to address disease states and complexity. The OCN constructed from the experimentally verified genes exhibits fractal nature in the topological properties with deeply rooted functional communities indicating self-organizing behavior. The network properties at all levels of organization obey one parameter scaling law which lacks centrality lethality rule. We showed that $\langle k\rangle $ can be taken as a scaling parameter, where, power law exponent can be estimated from the ratio of network diameters. The betweenness centrality $C_B$ shows two distinct behaviors one shown by high degree hubs and the other by segregated low degree nodes. The $C_B$ power law exponent is found to connect the exponents of distributions of high and low degree nodes. OCN showed the absence of rich-club formation which leads to the missing of a number of attractors in the network causing formation of weakly tied diverse functional modules to keep optimal network efficiency. In OCN, provincial and connector hubs, which includes identified key regulators, take major responsibility to keep the OCN integrity and organization. Further, most of the key regulators are found to be over expressed and positively correlated with immune infiltrates. Finally, few potential drugs are identified related to the key regulators.

Genomic Analyses for Predictors of Response to Chemoradiation in Stage III Non-Small Cell Lung Cancer

Background

Radiation with platinum-based chemotherapy is the standard of care for unresectable stage III non-small cell lung cancer (NSCLC). Despite aggressive treatment, progression-free survival and overall survival remain poor. It is unclear whether any tumor genetic mutations are associated with response to chemoradiation therapy.

Methods

We retrospectively reviewed clinical outcomes of patients with stage III NSCLC treated with definitive radiation who had undergone tumor molecular profiling through a next-generation DNA sequencing platform. Cox proportional hazards model was used to investigate associations between clinical outcomes and genetic mutations detected by next-generation sequencing.

Results

110 patients were identified with stage III NSCLC and underwent definitive radiation between 2013 and 2017 and tumor molecular profiling. Concurrent or sequential chemotherapy was given in 104 patients (95%). Unbiased genomic analyses revealed a significant association between AKT2 mutations and decreased local-regional tumor control and overall survival (hazard ratios [HR] 12.5 and 13.7, P = .003 and P = .003, respectively). Analyses restricted to loss-of-function mutations identified KMT2C and KMT2D deleterious mutations as negative prognostic factors for overall survival (HR 13.4 and 7.0, P < .001 and P < .001, respectively). Deleterious mutations in a panel of 38 DNA damage response and repair pathway genes were associated with improved local-regional control (HR 0.32, P = .049).

Conclusions

This study coupled multiplexed targeted sequencing with clinical outcome and identified mutations in AKT2, KMT2C, and KMT2D as negative predictors of local-regional control and survival, and deleterious mutations in damage response and repair pathway genes were associated with improved local-regional disease control after chemoradiation therapy. These findings will require validation in a larger cohort of patients with prospectively collected and detailed clinical information.

Identification of a prognostic signature of epithelial ovarian cancer based on tumor immune microenvironment exploration

This study aims to develop an immune-related genes (IRGs) prognostic signature to stratify the epithelial ovarian cancer (EOC) patients. We identified 332 up- and 154 down-regulated EOC-specific IRGs. As a result, candidate IRGs were idendified to construct prognostic models respectivy for overall survial and progression-free survival. The risk score was validated as a risk factor for prognosis and was used to built a combined nomogram. According to the IRG-related prognostic model, EOC patients were divided into high- and low- risk group and were further explored their association with tumor immune microenvironment (TME). CIBERSORT algorithm showed higher macrophages M1 cell, T cells follicular helper cell and plasma cells infiltrating levels in the low-risk group. In addition, the low-risk group was found with higher immunophenoscore and distinct mutation signatures compared with the high-risk group. These findings may shed light on the development of novel immune biomarkers and target therapy of EOC.

Transcriptomic evidence that insulin signalling pathway regulates the ageing of subterranean termite castes

Insulin is a protein hormone that controls the metabolism of sugar, fat and protein via signal transduction in cells, influencing growth and developmental processes such as reproduction and ageing. From nematodes to fruit flies, rodents and other animals, glucose signalling mechanisms are highly conserved. Reproductive termites (queens and kings) exhibit an extraordinarily long lifespan relative to non-reproductive individuals such as workers, despite being generated from the same genome, thus providing a unique model for the investigation of longevity. The key reason for this molecular mechanism, however, remains unclear. To clarify the molecular mechanism underlying this phenomenon, we sequenced the transcriptomes of the primary kings (PKs), primary queens (PQs), male (WMs) and female (WFs) workers of the lower subterranean termite Reticulitermes chinensis. We performed RNA sequencing and identified 33 insulin signalling pathway-related genes in R. chinensis. RT-qPCR analyses revealed that EIF4E and RPS6 genes were highly expressed in WMs and WFs workers, while mTOR expression was lower in PKs and PQs than in WMs and WFs. PQs and PKs exhibited lower expression of akt2-a than female workers. As the highly conserved insulin signalling pathway can significantly prolong the healthspan and lifespan, so we infer that the insulin signalling pathway regulates ageing in the subterranean termite R. chinensis. Further studies are recommended to reveal the biological function of insulin signalling pathway-related genes in the survival of termites to provide new insights into biomolecular homeostasis maintenance and its relationship to remarkable longevity.

Long Noncoding RNA NEAT1 Promotes Cell Proliferation And Invasion And Suppresses Apoptosis In Hepatocellular Carcinoma By Regulating miRNA-22-3p/akt2 In Vitro And In Vivo

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most aggressive cancers that is associated with cirrhosis and other chronic liver diseases. Although remarkable progress has been made in past decades, it is still necessary to continue exploring the pathology and development of HCC.

OBJECTIVE

In this study, we elucidated the effect of long noncoding RNA (lncRNA) NEAT1 on HCC development and underlying mechanisms.

METHODS

Clinicopathological features of HCC patients were collected and the correlations with NEAT1 expression were assessed. To determine cell activities, CCK-8, flow cytometry, invasion assays, and TUNEL assays were performed. Real-time PCR, Western blot, and luciferase reporter assays were performed to investigate the related mechanism of HCC.

RESULTS

The results revealed that NEAT1 expression was associated with tumor size and differentiation where NEAT1 was upregulated in both HCC tissues and cell lines. Overexpression of NEAT1 promoted proliferation and invasion while inhibited apoptosis in HCC cells, which was opposite to the effect of NEAT1 knockdown. Also, AKT2 was increased in HCC tissues. Downregulation of AKT2 was associated with reduced cell proliferation and invasion while increased apoptosis, while overexpression of AKT2 exerted opposite roles. In addition, the expression of miRNA-22-3p displayed an inverse association with NEAT1. miRNA-22-3p mimic and inhibitor suppressed and promoted HCC development, respectively. The luciferase assay revealed that both NEAT1 and AKT2 were direct target genes of miRNA-22-3p. Furthermore, knockdown and overexpression of NEAT1 suppressed and promoted tumor growth in the HCC mouse model, which were abolished by the miRNA-22-3p inhibitor and mimic, respectively.

CONCLUSION

In conclusion, the results demonstrate that NEAT1 promotes the development of HCC, both in vitro and in vivo, through regulating miRNA-22-3p/AKT2, and provides insight into developing a new strategy for HCC treatment.

TSPAN8 serves as a prognostic marker involving Akt/MAPK pathway in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a common epithelial carcinoma with high occurrence and metastatic rates in Southern China. To date, the molecular mechanisms of metastasis for NPC remains unclear. The aim of this study was to discover the underlying mechanism of NPC and to elucidate novel genes that may play important roles in NPC progression and metastasis.

METHODS

We carry out mRNA expression profiling, Arraystar Human mRNA Expression Profiling Service Report based on polymerase chain reaction (PCR) using four pairs of tumor tissues and their corresponding benign adjacent tissues from NPC patients.

RESULTS

We found that 1,787 genes were differentially expressed, among them, 8 genes were identified as highly upregulated in NPC patients. Within these 8 genes, only TSPAN8 was consistently over-expressed in poorly differentiated CNE2 cell line and highly-metastatic subclone S18 cell line. TSPAN8 mRNA and protein levels were increased in primary carcinoma tissues compared to their corresponding adjacent benign tissues. Knockdown of TSPAN8 by siRNA resulted in inhibition of NPC cell migration and invasion, while overexpression of TSPAN8 promoted NPC cell migration, invasion and proliferation. To explore the potential metastasis pathway mechanism for NPC, TSPAN8 were silenced in CNE2 cell. From the Tumor Metastasis Pathway Finder PCR array, knockdown of TSPAN8 led to the down-regulation of IL-1β, which showed the most down-regulation among identified genes. IL-1β is a regulating factor of the Akt/MAPK pathway, which is involved in the cancer cell migration regulation. Furthermore, the down-regulation of TSPAN8 in CNE2 cell was associated with inhibition of the Akt/MAPK pathway. Immunohistochemistry (IHC) indicated that TSPAN8 level was increased in NPC tumors, which was associated with shorter overall survival and metastasis free survival (MFS).

CONCLUSIONS

The data indicated that TSPAN8 acting as a tumor migration marker and may be a prognostic factor or therapeutic target for NPC.

Sustainability of coral reefs are affected by ecological light pollution in the Gulf of Aqaba/Eilat

As human populations grow and lighting technologies improve, artificial light gradually alters natural cycles of light and dark that have been consistent over long periods of geological and evolutionary time. While considerable ecological implications of artificial light have been identified in both terrestrial and aquatic habitats, knowledge about the physiological and molecular effects of light pollution is vague. To determine if ecological light pollution (ELP) impacts coral biological processes, we characterized the transcriptome of the coral Acropora eurystoma under two different light regimes: control conditions and treatment with light at night. Here we show that corals exposed to ELP have approximately 25 times more differentially expressed genes that regulate cell cycle, cell proliferation, cell growth, protein synthesis and display changes in photo physiology. The finding of this work confirms that ELP acts as a chronic disturbance that may impact the future of coral reefs.

Mining Featured Biomarkers Linked with Epithelial Ovarian CancerBased on Bioinformatics

Epithelial ovarian cancer (EOC) is the18th most common cancer worldwide and the 8th most common in women. The aim of this study was to diagnose the potential importance of, as well as novel genes linked with, EOC and to provide valid biological information for further research. The gene expression profiles of E-MTAB-3706 which contained four high-grade ovarian epithelial cancer samples, four normal fallopian tube samples and four normal ovarian epithelium samples were downloaded from the ArrayExpress database. Pathway enrichment and Gene Ontology (GO) enrichment analysis of differentially expressed genes (DEGs) were performed, and protein-protein interaction (PPI) network, microRNA-target gene regulatory network and TFs (transcription factors) -target gene regulatory network for up- and down-regulated were analyzed using Cytoscape. In total, 552 DEGs were found, including 276 up-regulated and 276 down-regulated DEGs. Pathway enrichment analysis demonstrated that most DEGs were significantly enriched in chemical carcinogenesis, urea cycle, cell adhesion molecules and creatine biosynthesis. GO enrichment analysis showed that most DEGs were significantly enriched in translation, nucleosome, extracellular matrix organization and extracellular matrix. From protein-protein interaction network (PPI) analysis, modules, microRNA-target gene regulatory network and TFs-target gene regulatory network for up- and down-regulated, and the top hub genes such as E2F4, SRPK2, A2M, CDH1, MAP1LC3A, UCHL1, HLA-C (major histocompatibility complex, class I, C), VAT1, ECM1 and SNRPN (small nuclear ribonucleoprotein polypeptide N) were associated in pathogenesis of EOC. The high expression levels of the hub genes such as CEBPD (CCAAT enhancer binding protein delta) and MID2 in stages 3 and 4 were validated in the TCGA (The Cancer Genome Atlas) database. CEBPD andMID2 were associated with the worst overall survival rates in EOC. In conclusion, the current study diagnosed DEGs between normal and EOC samples, which could improve our understanding of the molecular mechanisms in the progression of EOC. These new key biomarkers might be used as therapeutic targets for EOC.

Deciphering the Nutraceutical Potential of Raphanus sativus-A Comprehensive Overview

Raphanus sativus (Radish) belongs to the Brassicaceae family and is a widely consumed root vegetable all around the world. The nutritional and medicinal values of radishes have been proven by several researches. Extracts prepared from the aerial and underground parts of radishes have been used in the treatment of stomach disorders, urinary infections, hepatic inflammation, cardiac disorders and ulcers in folk medicine since the ancient times. The pharmaceutical potential of radishes is attributed to the presence of its beneficial secondary metabolites, such as glucosinolates, polyphenols and isothiocyanates. The present review has focused on the impact of radish extract administration under pathological complications, such as cancer, diabetes, hepatic inflammation and oxidative stress. In addition, a comprehensive view of molecular mechanism behind the regulation of molecular drug targets associated with different types of cancers and diabetes by the bioactive compounds present in the radish extracts have been discussed in detail.

siRNA-Conjugated Nanoparticles to Treat Ovarian Cancer

Ovarian cancer is the fifth-most lethal cancer among women due to a lack of early detection and late-stage treatment options, and it is responsible for more than 14,000 deaths each year in the United States. Recently, there have been advances in RNA interference therapy, specifically with small interfering RNA (siRNA), to reduce tumor burden for ovarian cancer via gene down-regulation. However, delivery of siRNA poses its own challenges, as siRNA is unstable in circulation, is unable to be effectively internalized by cells, and may cause toxicity in off-target sites. To address such challenges, nanoparticle carriers have emerged as delivery platforms for the biocompatible, targeted delivery of siRNA-based therapies. Several preclinical studies have shown the promising effects of siRNA therapy to reduce chemotherapy resistance and proliferation of ovarian cancer cells. This review evaluates the recent advances, clinical applications, and future potential of nanoparticle-mediated delivery of siRNA therapeutics to target genes implicated in ovarian cancer.

A Recombinant Affinity Reagent Specific for a Phosphoepitope of Akt1

The serine/threonine-protein kinase, Akt1, plays an important part in mammalian cell growth, proliferation, migration and angiogenesis, and becomes activated through phosphorylation. To monitor phosphorylation of threonine 308 in Akt1, we developed a recombinant phosphothreonine-binding domain (pTBD) that is highly selective for the Akt1 phosphopeptide. A phage-display library of variants of the Forkhead-associated 1 (FHA1) domain of yeast Rad53p was screened by affinity selection to the phosphopeptide, 301-KDGATMKpTFCGTPEY-315, and yielded 12 binding clones. The strongest binders have equilibrium dissociation constants of 160–180 nanomolar and are phosphothreonine-specific in binding. The specificity of one Akt1-pTBD was compared to commercially available polyclonal antibodies (pAbs) generated against the same phosphopeptide. The Akt1-pTBD was either equal to or better than three pAbs in detecting the Akt1 pT308 phosphopeptide in ELISAs.

Interleukin-33 enhanced the migration and invasiveness of human lung cancer cells

Aim

Interleukin-33 (IL-33), belonging to IL-1 family cytokines, has been reported to participate in cancer growth and metastasis. The clinical values of IL-33 in lung cancer have been previously investigated. We aimed to elucidate the probable role of IL-33 in the migration and invasion of lung cancer cells.

Methods

Cell migration and invasiveness were tested by Transwell assay. Western blotting analysis was performed to detect protein expression.

Results

We found that IL-33 treatment in human lung A549 cells dose-dependently enhanced their migratory and invasive ability, accompanied by elevated expression of matrix metallo-proteinase (MMP) 2 and MMP9. Meanwhile, IL-33-induced cell migration and invasion were significantly abolished by small interfering RNA-targeting ST2, the specific receptor of IL-33. Furthermore, IL-33 exposure induced the phosphorylation of AKT. Pretreatment with an AKT inhibitor LY294002 markedly attenuated IL-33-induced cell migration and invasion.

Conclusion

IL-33/ST2 promoted the migration and invasiveness of lung cancer cells through AKT pathway. Our findings strongly suggest that IL-33 may serve as a promising therapeutic strategy for lung cancer.

Dysregulation of AKT3 along with a small panel of mRNAs stratifies high-grade serous ovarian cancer from both normal epithelia and benign tumor tissues

Screening methods of High-Grade Serous Ovarian Cancer (HGSOC) lack specificity and sensitivity, partly due to benign tumors producing false-positive findings. We utilized a differential expression analysis pipeline on malignant tumor (MT) and normal epithelial (NE) samples, and also filtered the results to discriminate between MT and benign tumor (BT). We report that a panel of 26 dysregulated genes stratifies MT from both BT and NE. We further validated our findings by utilizing unsupervised clustering methods on two independent datasets. We show that the 26-genes panel completely distinguishes HGSOC from NE, and produces a more accurate classification between HGSOC and BT. Pathway analysis reveals that AKT3 is of particular significance, because of its high fold change and appearance in the majority of the dysregulated pathways. mRNA patterns of AKT3 suggest essential connections with tumor growth and metastasis, as well as a strong biomarker potential when used with 3 other genes (PTTG1, MND1, CENPF). Our results show that dysregulation of the 26-mRNA signature panel provides an evidence of malignancy and contribute to the design of a high specificity biomarker panel for detection of HGSOC, potentially in an early more curable stage.

miR-608 regulates apoptosis in human lung adenocarcinoma via regulation of AKT2

Lung cancer remains a major health problem with a low 5-year survival rate of patients. Recent studies have shown that dysregulation of microRNAs (miRNAs) are prevalent in lung cancer and these aberrations play a significant role in the progression of tumour progression. In the present study, bioinformatics analyses was employed to predict potential miR-608 targets, which are associated with signaling pathways involved in cancer. Luciferase reporter assay identified AKT2 as a novel target of miR-608, and suppression of its protein levels was validated through western blot analysis. Zebrafish embryos were microinjected with cells transfected with miR-608 to elucidate the role of miR-608 in vivo, and immunostained with antibodies to detect activated caspase-3. We present the first evidence that miR-608 behaves as a tumour suppressor in A549 and SK-LU-1 cells through the regulation of AKT2, suggesting that selective targeting of AKT2 via miR-608 may be developed as a potential therapeutic strategy for miRNA-based non-small cell lung cancer (NSCLC) therapy.

The down-regulation of TAPP2 inhibits the migration of esophageal squamous cell carcinoma and predicts favorable outcome

Tandem pH domain-containing proteins TAPP1 and TAPP2 are adaptor proteins that specifically bind to phosphatidylinositol-3,4-bisphosphate, or PI(3,4)P2, a product of phosphoinositide 3-kinases (PI3K). Although PI3K enzymes have multiple functions in cell biology, including cell migration, the functions of PI (3, 4) P2 and its binding proteins are not well understood. Previously studies found that TAPP2 is highly expressed in primary leukemic B cells that have strong migratory capacity. However, the function and underlying mechanisms of TAPP2 in ESCC remain largely unknown. In the present study, we investigated the level of TAPP2 in human esophageal squamous cell carcinoma (ESCC) tissues and in corresponding adjacent non-tumor tissues by immunohistochemistry (IHC) and western blot analyses. TAPP2 protein level was increased in ESCC tissues compared with corresponding adjacent non-tumor tissues. In vitro experiments showed that under-expression of TAPP2 reduced ESCC cell TE1 migration by wound-healing assays and transwell migration assays, and it was concurrent with the decreased expression of the phosphorylation of AKT. Taken together, these findings suggested that TAPP2 serves as oncogenic gene in ESCC and may serve as a new target for ESCC therapy.

Targeting the AKT pathway: Repositioning HIV protease inhibitors as radiosensitizers

Cellular resistance in tumour cells to different therapeutic approaches has been a limiting factor in the curative treatment of cancer. Resistance to therapeutic radiation is a common phenomenon which significantly reduces treatment options and impacts survival. One of the mechanisms of acquiring resistance to ionizing radiation is the overexpression or activation of various oncogenes like the EGFR (epidermal growth factor receptor), RAS (rat sarcoma) oncogene or loss of PTEN (phosphatase and tensin homologue) which in turn activates the phosphatidyl inositol 3-kinase/protein kinase B (PI3-K)/AKT pathway responsible for radiation resistance in various tumours. Blocking the pathway enhances the radiation response both in vitro and in vivo. Due to the differential activation of this pathway (constitutively activated in tumour cells and not in the normal host cells), it is an excellent candidate target for molecular targeted therapy to enhance radiation sensitivity. In this regard, HIV protease inhibitors (HPIs) known to interfere with PI3-K/AKT signaling in tumour cells, have been shown to sensitize various tumour cells to radiation both in vitro and in vivo. As a result, HPIs are now being investigated as possible radiosensitizers along with various chemotherapeutic drugs. This review describes the mechanisms by which PI3-K/AKT pathway causes radioresistance and the role of HIV protease inhibitors especially nelfinavir as a potential candidate drug to target the AKT pathway for overcoming radioresistance and its use in various clinical trials for different malignancies.

MicroRNAs driving invasion and metastasis in ovarian cancer: Opportunities for translational medicine (Review)

Epithelial ovarian cancer is the fifth most frequent cause of cancer death in women. In spite of the advantages in early detection and treatment options, overall survival rates have improved only slightly in the last decades. Therefore, alternative therapeutic approaches need to overcome resistance and improve the patient survival and outcome. MicroRNAs are evolutionary conserved small non-coding RNAs that function as negative regulators of gene expression by inhibiting translation or inducing degradation of messenger RNAs. In cancer, microRNAs are aberrantly expressed thus representing potential prognostic biomarkers and novel therapeutic targets. The knowledge of novel and unexpected functions of microRNAs is rapidly evolving and the advance in the elucidation of potential clinical applications deserves attention. Recently, a specific set of microRNAs dubbed as metastamiRs have been shown to initiate invasion and metastasis in diverse types of cancer. We reviewed the current status of microRNAs in development and progression of ovarian cancer with a special emphasis on tumor cells invasion and metastasis. Also, we show an update of microRNA functions in oncogenic pathways and discuss the current scenario for potential applications in clinical and translational research in ovarian cancer.

Evaluation of PIK3CA mutations as a biomarker in Chinese breast carcinomas from Western China

BACKGROUND

PIK3CA gene encodes the p110 α catalytic subunit of the oncoprotein phosphatidylinositol 3-kinase (PI3 K) which regulates many biological processes such as cell proliferation, differentiation, migration and survival through the activation of various signaling pathways.

OBJECTIVE

In this study, we have investigated the possible somatic mutations in PIK3CA gene in invasive ductal breast carcinomas of Chinese women from Western China.

METHODS

Genomic DNA was extracted from the formalin-fixed paraffin-embedded (FFPE) tissue samples. The hotspot mutations in PIK3CA gene of exon 9 and exon 20 were studied by pyrosequencing.

RESULTS

The sequencing identified two hotspot mutations in exon 20 of one cancer samples at p. H1047L (c. 3140A > T) and eight cancer sample at p. H1047R (c. 3140A > G). No mutation in exon 9 of PIK3CA gene was found in these breast cancer tissue samples. PIK3CA mutations showed surprising clinicopathological features in breast cancer patients, as incidence of lymph node invasiveness is increased in the patients with PIK3CA mutation. In addition, all the patients showed tumor size bigger than 3 cm in diameter. It is important that for early detection and early treatment for BC in developing countries or areas like Western China, and for people to provide popularization education using scientific knowledge in cancer fields.

CONCLUSIONS

This study identified PIK3CA mutations in breast carcinoma patients of Western China that will enable a more rapid molecular diagnosis, and provide a stronger rationale evidence for development of precision therapeutic approaches as well as promising therapeutic targets for breast cancer treatment or patient management.

HPIP promotes epithelial-mesenchymal transition and cisplatin resistance in ovarian cancer cells through PI3K/AKT pathway activation

PURPOSE

Hematopoietic PBX interacting protein (HPIP), a scaffold protein, is known to regulate the proliferation, migration and invasion in different cancer cell types. The aim of this study was to assess the role of HPIP in ovarian cancer cell migration, invasion and epithelial-mesenchymal transition (EMT), and to unravel the mechanism by which it regulates these processes.

METHODS

HPIP expression was assessed by immunohistochemistry of tissue microarrays containing primary ovarian tumor samples of different grades. OAW42, an ovarian carcinoma-derived cell line exhibiting a high HPIP expression, was used to study the role of HPIP in cell migration, invasion and EMT. HPIP knockdown in these cells was achieved using a small hairpin RNA (shRNA) approach. Cell migration and invasion were assessed using scratch wound and transwell invasion assays, respectively. The extent of EMT was assessed by determining the expression levels of Snail, Vimentin and E-cadherin using Western blotting. The effect of HPIP expression on AKT and MAPK activation was also investigated by Western blotting. Cell viabilities in response to cisplatin treatment were assessed using a MTT assay, whereas apoptosis was assessed by determining caspase-3 and PARP cleavage in ovarian carcinoma-derived SKOV3 cells.

RESULTS

We found that HPIP is highly expressed in high-grade primary ovarian tumors. In addition, we found that HPIP promotes the migration, invasion and EMT in OAW42 cells and induces EMT in these cells via activation of the PI3K/AKT pathway. The latter was found to lead to stabilization of the Snail protein and to repression of E-cadherin expression through inactivation of GSK-3β. We also found that HPIP expression confers cisplatin resistance to SKOV3 cells after prolonged exposure and that its subsequent knockdown decreases the viability of these cells and increases caspase-3 activation and PARP proteolysis in these cells following cisplatin treatment.

CONCLUSIONS

From these results we conclude that HPIP expression is associated with high-grade ovarian tumors and may promote their migration, invasion and EMT, a process that is associated with metastasis. In addition, we conclude that HPIP may serve as a potential therapeutic target for cisplatin resistant ovarian tumors.

IWR-1 inhibits epithelial-mesenchymal transition of colorectal cancer cells through suppressing Wnt/β-catenin signaling as well as survivin expression

Aberrant activation of Wnt/β-catenin signaling is frequently observed in patients with colorectal cancer (CRC) and is considered a major determinant of CRC pathogenesis. CRC pathogenesis is particularly accompanied by epithelial-mesenchymal transition (EMT) and survivin expression. Here, we investigated the potential and mechanism of a novel Wnt/β-catenin inhibitor IWR-1 to suppress tumor metastasis in relation with EMT and survivin expression. We first determined the EMT reversal effects of IWR-1 in in vitro (HCT116 and HT29 cells) and ex vivo (specimens of CRC patients) CRC models. It was shown that IWR-1 inhibited cell proliferation and EMT even in the presence of TNF-α-induced cancer cell stimulation. IWR-1 also significantly suppressed cell migration, invasion, and matrix metalloproteinase activities of CRC cell lines. Furthermore, we showed the evidence that IWR-1 provides EMT reversal effects by directly suppressing survivin expression by the followings: 1) IWR-1 could not completely inhibit EMT in survivin-overexpressing HCT116 cells, 2) EMT reversal effects of IWR-1 were more pronounced in survivin-suppressed cells, and 3) Survivin promoter assay directly identified the survivin promoter region responsible for inhibition of survivin transcription by IWR-1. Taken altogether, our results demonstrate that IWR-1 has the potential to suppress tumor metastasis by inhibiting Wnt/β-catenin pathway as well as survivin expression. Therefore, IWR-1 could be considered for future clinical use as a therapeutic agent to treat CRC.

MK-2206 sensitizes BRCA-deficient epithelial ovarian adenocarcinoma to cisplatin and olaparib

BACKGROUND

Platinum resistance is a major obstacle in the treatment of epithelial ovarian cancer (EOC). Activation of the AKT pathway promotes platinum resistance while inhibition of AKT sensitizes chemoresistant cells. Patients with BRCA mutant EOC, and thus a defect in the homologous recombination (HR) repair pathway, demonstrate greater clinical response to platinum and olaparib therapy than patients with BRCA wild-type EOC. MK-2206, an allosteric inhibitor of AKT phosphorylation, sensitizes a variety of cell types to various anticancer agents and is currently undergoing phase II trials as monotherapy for platinum-resistant ovarian, fallopian tube, and peritoneal cancer. This study examines the differential effects of AKT inhibition with cisplatin and olaparib therapy in BRCA1/2-deficient versus wild-type EOC.

METHODS

PEO1, a chemosensitive BRCA2-mutant serous ovarian adenocarcinoma, and PEO4, a reverted BRCA2-proficient line from the same patient after the development of chemotherapeutic resistance, were primarily used for the study. In PEO1, MK-2206 demonstrated moderate to strong synergism with cisplatin and olaparib at all doses, while demonstrating antagonism at all doses in PEO4.

RESULTS

Baseline phospho-AKT activity in untreated cells was upregulated in both BRCA1- and 2-deficient cell lines. MK-2206 prevented cisplatin- and olaparib-induced AKT activation in the BRCA2-deficient PEO1 cells. We propose that BRCA-deficient EOC cells upregulate baseline AKT activity to enhance survival in the absence of HR. Higher AKT activity is also required to withstand cytotoxic agent-induced DNA damage, leading to strong synergism between MK-2206 and cisplatin or olaparib therapy in BRCA-deficient cells.

CONCLUSIONS

MK-2206 shows promise as a chemosensitization agent in BRCA-deficient EOC and merits clinical investigation in this patient population.

Gene expression profiling analysis of ovarian cancer

As a gynecological oncology, ovarian cancer has high incidence and mortality. To study the mechanisms of ovarian cancer, the present study analyzed the GSE37582 microarray. GSE37582 was downloaded from Gene Expression Omnibus and included data from 74 ovarian cancer cases and 47 healthy controls. The differentially-expressed genes (DEGs) were screened using linear models for microarray data package in R and were further screened for functional annotation. Next, Gene Ontology and pathway enrichment analysis of the DEGs was conducted. The interaction associations of the proteins encoded by the DEGs were searched using the Search Tool for the Retrieval of Interacting Genes, and the protein-protein interaction (PPI) network was visualized by Cytoscape. Moreover, module analysis of the PPI network was performed using the BioNet analysis tool in R. A total of 284 DEGs were screened, consisting of 145 upregulated genes and 139 downregulated genes. In particular, downregulated FBJ murine osteosarcoma viral oncogene homolog (FOS) was an oncogene, while downregulated cyclin-dependent kinase inhibitor 1A (CDKN1A) was a tumor suppressor gene and upregulated cluster of differentiation 44 (CD44) was classed as an 'other' gene. The enriched functions included collagen catabolic process, stress-activated mitogen-activated protein kinases cascade and insulin receptor signaling pathway. Meanwhile, FOS (degree, 15), CD44 (degree, 9), B-cell CLL/lymphoma 2 (BCL2; degree, 7), CDKN1A (degree, 7) and matrix metallopeptidase 3 (MMP3; degree, 6) had higher connectivity degrees in the PPI network for the DEGs. These genes may be involved in ovarian cancer by interacting with other genes in the module of the PPI network (e.g., BCL2-FOS, BCL2-CDKN1A, FOS-CDKN1A, FOS-CD44, MMP3-MMP7 and MMP7-CD44). Overall, BCL2, FOS, CDKN1A, CD44, MMP3 and MMP7 may be correlated with ovarian cancer.

Inhibition of Phospho-S6 Kinase, a Protein Involved in the Compensatory Adaptive Response, Increases the Efficacy of Paclitaxel in Reducing the Viability of Matrix-Attached Ovarian Cancer Cells

OBJECTIVE

To identify the proteins involved the compensatory adaptive response to paclitaxel in ovarian cancer cells and to determine whether inhibition of the compensatory adaptive response increases the efficacy of paclitaxel in decreasing the viability of cancer cells.

METHODS

We used a reverse-phase protein array and western blot analysis to identify the proteins involved in the compensatory mechanism induced by paclitaxel in HeyA8 and SKOV3 ovarian cancer cells. We used a cell viability assay to examine whether inhibition of the proteins involved in the compensatory adaptive response influenced the effects of paclitaxel on cancer cell viability. All experiments were performed in three-dimensional cell cultures.

RESULTS

Paclitaxel induced the upregulation of pS6 (S240/S244) and pS6 (S235/S236) in HeyA8 and SKOV3 cells, and pPRAS40 (T246) in HeyA8 cells. BX795 and CCT128930 were chosen as inhibitors of pS6 (S240/S244), pS6 (S235/S236), and pPRAS40 (T246). BX795 and CCT128930 decreased pS6 (S240/S244) and pS6 (S235/S236) expression in HeyA8 and SKOV3 cells. However, pPRAS40 (T246) expression was inhibited only by BX795 and not by CCT128930 in HeyA8 cells. Compared with paclitaxel alone, addition of BX795 or CCT128930 to paclitaxel was more effective in decreasing the viability of HeyA8 and SKOV3 cells.

CONCLUSION

Addition of BX795 or CCT128930 to inhibit pS6 (S240/S244) or pS6 (S235/S236) restricted the compensatory adaptive response to paclitaxel in HeyA8 and SKOV3 cells. These inhibitors increased the efficacy of paclitaxel in reducing cancer cell viability.

Methanolic Extract of Pien Tze Huang Induces Apoptosis Signaling in Human Osteosarcoma MG63 Cells via Multiple Pathways

Pien Tze Huang (PZH) is a well-known traditional Chinese formulation and has long been used as an alternative remedy for cancers in China and Southeast Asia. Recently, antitumor activity of PZH on several tumors have been increasingly reported, but its antitumor activity and the possible action mechanism on osteosarcoma remains unclear. After treatment with PZH, cell viability of MG-63 cells was dose-dependently inhibited compared to control cells. Moreover, a DNA ladder characteristic of apoptosis was observed in the cells treated with PZH, especially 500 μg/mL, 750 μg/mL. Further investigation showed that PZH treatments led to activation of caspase cascades and changes of apoptotic mediators Bcl2, Bax, and Bcl-xL expression. In addition, our results suggested that PZH activated PI3K/Akt signal pathway, and the phosphorylation of Akt and ERK1/2 were associated with the induction of apoptotic signaling. These results revealed that PZH possesses antitumoral activity on human osteosarcoma MG63 cells by manipulating apoptotic signaling and multiple pathways. It is suggested that PZH alone or combined with regular antitumor drugs may be beneficial as osteosarcoma treatments.

Coumestrol suppresses proliferation of ES2 human epithelial ovarian cancer cells

Coumestrol, which is predominantly found in soybean products as a phytoestrogen, has cancer preventive activities in estrogen-responsive carcinomas. However, effects and molecular targets of coumestrol have not been reported for epithelial ovarian cancer (EOC). In the present study, we demonstrated that coumestrol inhibited viability and invasion and induced apoptosis of ES2 (clear cell-/serous carcinoma origin) cells. In addition, immunoreactive PCNA and ERBB2, markers of proliferation of ovarian carcinoma, were attenuated in their expression in coumestrol-induced death of ES2 cells. Phosphorylation of AKT, p70S6K, ERK1/2, JNK1/2, and p90RSK was inactivated by coumestrol treatment in a dose- and time-dependent manner as determined in western blot analyses. Moreover, PI3K inhibitors enhanced effects of coumestrol to decrease phosphorylation of AKT, p70S6K, S6, and ERK1/2. Furthermore, coumestrol has strong cancer preventive effects as compared to other conventional chemotherapeutics on proliferation of ES2 cells. In conclusion, coumestrol exerts chemotherapeutic effects via PI3K and ERK1/2 MAPK pathways and is a potentially novel treatment regimen with enhanced chemoprevention activities against progression of EOC.

Androgen receptor-mediated non-genomic regulation of prostate cancer cell proliferation

Androgen receptor (AR)-mediated signaling is necessary for prostate cancer cell proliferation and an important target for therapeutic drug development. Canonically, AR signals through a genomic or transcriptional pathway, involving the translocation of androgen-bound AR to the nucleus, its binding to cognate androgen response elements on promoter, with ensuing modulation of target gene expression, leading to cell proliferation. However, prostate cancer cells can show dose-dependent proliferation responses to androgen within minutes, without the need for genomic AR signaling. This proliferation response known as the non-genomic AR signaling is mediated by cytoplasmic AR, which facilitates the activation of kinase-signaling cascades, including the Ras-Raf-1, phosphatidyl-inositol 3-kinase (PI3K)/Akt and protein kinase C (PKC), which in turn converge on mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) activation, leading to cell proliferation. Further, since activated ERK may also phosphorylate AR and its coactivators, the non-genomic AR signaling may enhance AR genomic activity. Non-genomic AR signaling may occur in an ERK-independent manner, via activation of mammalian target of rapamycin (mTOR) pathway, or modulation of intracellular Ca²⁺ concentration through plasma membrane G protein-coupled receptors (GPCRs). These data suggest that therapeutic strategies aimed at preventing AR nuclear translocation and genomic AR signaling alone may not completely abrogate AR signaling. Thus, elucidation of mechanisms that underlie non-genomic AR signaling may identify potential mechanisms of resistance to current anti-androgens and help developing novel therapies that abolish all AR signaling in prostate cancer.

Highly efficient Gab2 siRNA delivery to ovarian cancer cells mediated by chitosan–polyethyleneimine nanoparticles

Malignant bowel obstruction (MBO) is a serious complication which causes high death rate and low quality of life (QOL) for patients diagnosed at an advanced stage of ovarian cancer.

miR-203 promotes proliferation, migration and invasion by degrading SIK1 in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is among the most lethal human cancers and it is insensitive to many chemotherapeutic drugs. The molecular basis of pancreatic cancer remains to be elucidated. Investigations into the molecular mechanism involved in the development and progression as well as drug resistance of the disease may be useful to understand the pathogenesis and progression of the disease and offer new targets for effective therapies. In the present study, we showed that salt-inducible kinase 1 (SIK1) was downregulated and loss of SIK1 was associated with gemcitabine resistance in pancreatic cancer. In pancreatic cancer cells, SIK1 inhibited proliferation, migration and invasion. An analysis of potential microRNA target sites was performed using the prediction algorithms, miRanda, TargetScan and PicTar. The three algorithms predicted that miR-203 is capable of targeting 3'UTR of SIK1. Subsequent experiments confirmed the prediction. In addition, the results showed that miR-203 promotes proliferation, migration and invasion in pancreatic cancer cells, whereas the restoration of SIK1 abrogated the regulation of pre-miR‑203-mediated proliferation, migration and invasion.

The relevance of molecular biomarkers in cervical cancer patients treated with radiotherapy

BACKGROUND

Radiotherapy (RT) plays an integral role in the combined-modality management of cervical cancer. Various molecular mechanisms have been implicated in the adaptive cellular response to RT. Identification of these molecular processes may permit the prediction of treatment outcome and enhanced radiation-induced cancer cell killing through tailoring of the management approach, and/or the employment of selective inhibitors of these pathways.

METHODS

PubMed was searched for studies presenting biomarkers of cervical cancer radioresistance validated in patient studies or in laboratory experimentation.

RESULTS

Several biomarkers of cervical cancer radioresistance are validated by patient survival or recurrence data. These biomarkers fall into categories of biological function including hypoxia, cell proliferation, cell-cell adhesion, and evasion of apoptosis. Additional radioresistance biomarkers have been identified in exploratory experiments.

CONCLUSIONS

Biomarkers of radioresistance in cervical cancer may allow molecular profiling of individual tumors, leading to tailored therapies and better prognostication and prediction of outcomes.

Alcohol and Apoptosis: Friends or Foes?

Alcohol abuse causes 79,000 deaths stemming from severe organ damage in the United States every year. Clinical manifestations of long-term alcohol abuse on the cardiac muscle include defective contractility with the development of dilated cardiomyopathy and low-output heart failure; which has poor prognosis with less than 25% survival for more than three years. In contrast, low alcohol consumption has been associated with reduced risk of cardiovascular disease, however the mechanism of this phenomenon remains elusive. The aim of this study was to determine the significance of apoptosis as a mediating factor in cardiac function following chronic high alcohol versus low alcohol exposure. Adult rats were provided 5 mM (low alcohol), 100 mM (high alcohol) or pair-fed non-alcohol controls for 4–5 months. The hearts were dissected, sectioned and stained with cresyl violet or immunohistochemically for caspase-3, a putative marker for apoptosis. Cardiomyocytes were isolated to determine the effects of alcohol exposure on cell contraction and relaxation. High alcohol animals displayed a marked thinning of the left ventricular wall combined with elevated caspase-3 activity and decreased contractility. In contrast, low alcohol was associated with increased contractility and decreased apoptosis suggesting an overall protective mechanism induced by low levels of alcohol exposure.

The MRTF-A/B function as oncogenes in pancreatic cancer

Despite evidence that MRTF-A/B, co-activators of serum response factor (SRF), promotes tumor cell invasion and metastasis in cancer, there are no studies describing MRTF-A/B in pancreatic cancer. To clarify involvement of MRTF-A/B expression in pancreatic cancer, we used quantitative reverse transcription-polymerase chain reaction and western blot analysis to detect MRTF-A/B in pancreatic cancer, intraductal papillary mucinous neoplasm (IPMN) and non-neoplastic pancreata. MRTF-A/B expression differs significantly between cancer and non-neoplastic tissues as well as between non-neoplastic tissues and IPMN bulk tissues. Next, we studied the roles of MRTF-A/B in vitro. Overexpression of MRTF-A/B promoted epithelial-mesenchymal transition (EMT) and generated stem cell-like cells in normal pancreatic cells. We performed quantitative reverse transcription-polymerase chain reaction to detect the level of MRTF-A/B in 19 pancreatic cancer cell lines. We found that their expression was associated with gemcitabine resistance. Like in normal pancreatic cells, MRTF-A/B also promoted EMT and promoted formation of stem cell-like cells in pancreatic cancer and they could regulate microRNA expression associated with EMT and CICs. Finally, to further demonstrate the roles of MRTF-A/B in vivo, we performed nude mouse model of s.c. xenograft and found that overexpression of MRTF-A and MRTF-B promoted pancreatic cancer growth. Elucidating the roles of MRTF-A/B will help us to further understand molecular basis of the disease and offer new gene targets for effective therapies.

Frequent and increased expression of human METCAM/MUC18 in cancer tissues and metastatic lesions is associated with the clinical progression of human ovarian carcinoma

OBJECTIVES

Human METCAM/MUC18 (huMETCAM/MUC18), a cell adhesion molecule, plays an important role in the progression of several epithelial cancers; however, its role in the progression of epithelial ovarian cancers is unknown. To initiate the study we determined expression of this protein in normal and cancerous ovarian tissues, cystadenomas, metastatic lesions, and ovarian cancer cell lines.

MATERIALS AND METHODS

Immunoblotting and immunohistochemical (IHC) methods were used to determine huMETCAM/MUC18 expression in lysates of frozen and formalin-fixed, paraffin-embedded tissue sections of normal human ovaries, and ovarian (benign) cystadenomas, carcinomas and metastatic lesions. We also determined expression levels of several downstream effectors of METCAM/MUC18 in these tissues.

RESULTS

HuMETCAM/MUC18 levels in ovarian carcinomas and metastatic lesions were significantly higher than in normal tissues and cystadenomas. IHC results showed that expression of huMETCAM/MUC18 in normal tissues and cystadenomas was mostly absent from epithelial cells, but in carcinomas and metastatic lesions it was localized to epithelial cells. In higher pathological grades of ovarian cancer and metastatic lesions, the percentage of cells stained in IHC was increased. Thirty percent of normal tissues weakly expressed the huMETCAM/MUC18 antigen, but 70% of cancer tissues and 100% of metastatic lesions expressed the antigen. Expression levels of several downstream effectors of huMETCAM/MUC18, Bcl2, PCNA and VEGF, were elevated in cancerous tissues, however, not that of Bax. The phospho-AKT/AKT ratio was elevated in metastatic lesions.

CONCLUSION

Upexpression of huMETCAM/MUC18 may be a marker for the malignant potential of ovarian carcinomas. Progression of ovarian cancer may involve increased signaling in anti-apoptosis, proliferation, survival/proliferation pathway, and angiogenesis.

The Akt isoforms, their unique functions and potential as anticancer therapeutic targets

Akt (also known as protein kinase B or PKB) is the major downstream nodal point of the PI3K signaling pathway. This pathway is a promising anticancer therapeutic target, because constitutive activation of the PI3K-Akt pathway is correlated with tumor development, progression, poor prognosis, and resistance to cancer therapies. The Akt serine/threonine kinase regulates diverse cellular functions including cell growth, proliferation, glucose metabolism, and survival. Although all three known Akt isoforms (Akt1-3) are encoded by separate genes, their amino acid sequences show a high degree of similarity. For this and other reasons, it has long been assumed that all three Akt isoforms are activated in the same way, and their functions largely overlap. However, accumulating lines of evidence now suggest that the three Akt isoforms might have unique modes of activation and many distinct functions. In particular, it has recently been found that the Akt isoforms are localized at different subcellular compartments in both adipocytes and cancer cells. In this review, we highlight the unique roles of each Akt isoform by introducing published data obtained from both in vitro and in vivo studies. We also discuss the significant potential of the Akt isoforms as effective anticancer therapeutic targets.

Functional specificity of Akt isoforms in cancer progression

Akt/PKB kinases are central mediators of cell homeostasis. There are three highly homologous Akt isoforms, Akt1/PKBα, Akt2/PKBβ and Akt3/PKBγ. Hyperactivation of Akt signaling is a key node in the progression of a variety of human cancer, by modulating tumor growth, chemoresistance and cancer cell migration, invasion and metastasis. It is now clear that, to understand the mechanisms on how Akt affects specific cancer cells, it is necessary to consider the relative importance of each of the three Akt isoforms in the altered cells. Akt1 is involved in tumor growth, cancer cell invasion and chemoresistance and is the predominant altered isoform found in various carcinomas. Akt2 is related to cancer cell invasion, metastasis and survival more than tumor induction. Most of the Akt2 alterations are observed in breast, ovarian, pancreatic and colorectal carcinomas. As Akt3 expression is limited to some tissues, its implication in tumor growth and resistance to drugs mostly occurs in melanomas, gliomas and some breast carcinomas. To explain how Akt isoforms can play different or even opposed roles, three mechanisms have been proposed: tissue-specificity expression/activation of Akt isoforms, distinct effect on same substrate as well as specific localization through the cyto-skeleton network. It is becoming clear that to develop an effective anticancer Akt inhibitor drug, it is necessary to target the specific Akt isoform which promotes the progression of the specific tumor.

Immunohistochemical characterization of the mTOR pathway in stage-I non-small-cell lung carcinoma

BACKGROUND

Dysregulation of mammalian target of rapamycin (mTOR) pathway has been linked with malignant tumorigenesis. This study explored the expression profiles of proteins involved in the mTOR pathway and their relationships with clinicopathologic characteristics in stage-I non-small-cell lung carcinoma (NSCLC).

METHODS

The protein expression profiles of PTEN, p-Akt, p-mTOR, p-S6, and eIF4E were examined using immunohistochemical staining and tissue microarray method in 408 patients with stage-I NSCLC (250 adenocarcinomas [ADC] and 158 squamous cell carcinomas).

RESULTS

Retained PTEN expression (P<0.001), p-mTOR expression (P<0.001), and p-S6 expression (P=0.007) were associated with ADC histology. Expression of PTEN (P=0.001), p-Akt (P=0.005), p-mTOR (P=0.007), p-S6 (P<0.001) were correlated with lower pathologic T stage. PTEN loss was correlated with male gender and smoking history and p-mTOR expression was inversely correlated with these factors (P<0.001). Subgroup analysis of ADCs indicated that male gender, high pT stage, lymphovascular invasion, and PTEN loss were poor prognostic factors. Multivariate analysis revealed that the PTEN(-)/p-Akt(+)/p-mTOR(+) combination more effectively determined the prognosis of ADC (hazard ratio=2.2, P=0.004) than PTEN alone.

CONCLUSIONS

Activation of the mTOR pathway in early-stage ADCs suggests a significant role for the mTOR axis in early carcinogenesis. The combination of PTEN(-)/p-Akt(+)/p-mTOR(+) expression was correlated with poor overall survival in patients with stage-I lung ADC.

Low levels of IGFBP7 expression in high-grade serous ovarian carcinoma is associated with patient outcome

BACKGROUND

Insulin-like growth factor binding protein 7 (IGFBP7) has been suggested to act as a tumour suppressor gene in various human cancers, yet its role in epithelial ovarian cancer (EOC) has not yet been investigated. We previously observed that IGFBP7 was one of several genes found significantly upregulated in an EOC cell line model rendered non-tumourigenic as consequence of genetic manipulation. The aim of the present study was to investigate the role of IGFBP7 in high-grade serous ovarian carcinomas (HGSC), the most common type of EOC.

METHODS

We analysed IGFBP7 gene expression in 11 normal ovarian surface epithelial cells (NOSE), 79 high-grade serous ovarian carcinomas (HGSC), and seven EOC cell lines using a custom gene expression array platform. IGFBP7 mRNA expression profiles were also extracted from publicly available databases. Protein expression was assessed by immunohistochemistry of 175 HGSC and 10 normal fallopian tube samples using tissue microarray and related to disease outcome. We used EOC cells to investigate possible mechanisms of gene inactivation and describe various in vitro growth effects of exposing EOC cell lines to human recombinant IGFBP7 protein and conditioned media.

RESULTS

All HGSCs exhibited IGFBP7 expression levels that were significantly (p = 0.001) lower than the mean of the expression value of NOSE samples and that of a whole ovary sample. IGFBP7 gene and protein expression were lower in tumourigenic EOC cell lines relative to a non-tumourigenic EOC cell line. None of the EOC cell lines harboured a somatic mutation in IGFBP7, although loss of heterozygosity (LOH) of the IGFBP7 locus and epigenetic methylation silencing of the IGFBP7 promoter was observed in two of the cell lines exhibiting loss of gene/protein expression. In vitro functional assays revealed an alteration of the EOC cell migration capacity. Protein expression analysis of HGSC samples revealed that the large majority of tumour cores (72.6%) showed low or absence of IGFBP7 staining and revealed a significant correlation between IGFBP7 protein expression and a prolonged overall survival (p = 0.044).

CONCLUSION

The low levels of IGFPB7 in HGSC relative to normal tissues, and association with survival are consistent with a purported role in tumour suppressor pathways.

Recurrent BCAM-AKT2 fusion gene leads to a constitutively activated AKT2 fusion kinase in high-grade serous ovarian carcinoma

High-grade serous ovarian cancer (HGSC) is among the most lethal forms of cancer in women. Excessive genomic rearrangements, which are expected to create fusion oncogenes, are the hallmark of this cancer. Here we report a cancer-specific gene fusion between BCAM, a membrane adhesion molecule, and AKT2, a key kinase in the PI3K signaling pathway. This fusion is present in 7% of the 60 patient cancers tested, a significant frequency considering the highly heterogeneous nature of this malignancy. Further, we provide direct evidence that BCAM-AKT2 is translated into an in-frame fusion protein in the patient's tumor. The resulting AKT2 fusion kinase is membrane-associated, constitutively phosphorylated, and activated as a functional kinase in cells. Unlike endogenous AKT2, whose activity is tightly regulated by external stimuli, BCAM-AKT2 escapes the regulation from external stimuli. Moreover, a BCAM-AKT2 fusion gene generated via chromosomal translocation using the CRISPR/Cas9 system leads to focus formation in both OVCAR8 and HEK-293T cell lines, suggesting that BCAM-AKT2 is oncogenic. Together, the results indicate that BCAM-AKT2 expression is a new mechanism of AKT2 kinase activation in HGSC. BCAM-AKT2 is the only fusion gene in HGSC that is proven to translate an aberrant yet functional kinase fusion protein with oncogenic properties. This recurrent genomic alteration is a potential therapeutic target and marker of a clinically relevant subtype for tailored therapy of HGSC.

Discovery of Akt kinase inhibitors through structure-based virtual screening and their evaluation as potential anticancer agents

Akt acts as a pivotal regulator in the PI3K/Akt signaling pathway and represents a potential drug target for cancer therapy. To search for new inhibitors of Akt kinase, we performed a structure-based virtual screening using the DOCK 4.0 program and the X-ray crystal structure of human Akt kinase. From the virtual screening, 48 compounds were selected and subjected to the Akt kinase inhibition assay. Twenty-six of the test compounds showed more potent inhibitory effects on Akt kinase than the reference compound, H-89. These 26 compounds were further evaluated for their cytotoxicity against HCT-116 human colon cancer cells and HEK-293 normal human embryonic kidney cells. Twelve compounds were found to display more potent or comparable cytotoxic activity compared to compound H-89 against HCT-116 colon cancer cells. The best results were obtained with Compounds a46 and a48 having IC₅₀ values (for HCT-116) of 11.1 and 9.5 µM, respectively, and selectivity indices (IC₅₀ for HEK-293/IC₅₀ for HCT-116) of 12.5 and 16.1, respectively. Through structure-based virtual screening and biological evaluations, we have successfully identified several new Akt inhibitors that displayed cytotoxic activity against HCT-116 human colon cancer cells. Especially, Compounds a46 and a48 may serve as useful lead compounds for further development of new anticancer agents.