MYC and EIF3H Coamplification significantly improve response and survival of non-small cell lung cancer patients (NSCLC) treated with gefitinib

The Presence of Small-Size Circulating Tumor Cells Predicts Worse Prognosis in Non-Small Cell Lung Cancer Patients

CONTEXT.—

Most patients with non-small cell lung cancers (NSCLC) are diagnosed at advanced stages. The 5-year survival rate of patients with advanced lung cancer is less than 20%, which makes lung cancer the leading cause of cancer-related deaths worldwide.

OBJECTIVE.—

To identify indicators that can predict the prognosis of lung cancer patients.

DESIGN.—

To determine the correlation between circulating tumor cells (CTCs), circulating tumor-derived endothelial cells (CTECs), and their subtypes and the prognosis of patients with NSCLC, 80 patients with lung cancer were recruited and 48 patients who met the enrollment criteria were selected in this study. Peripheral blood was collected from the enrolled patients before any treatment and analyzed by the subtraction enrichment and immunostaining-fluorescence in situ hybridization technique to determine the correlation between CTCs and CTECs and lung cancer disease progression and to identify prognostic indicators.

RESULTS.—

In all patients, the positive rate of CTCs was 100% and the positive rate of CTECs was 81.3%. Patients with advanced or lymph node metastases had a higher rate of small-size CTC positivity than those with early or no lymph node metastases. Large-size CTEC positivity was higher in patients with advanced NSCLC than in early-stage patients (P = .03). Patients with ≥1 small-size CTC had shorter progression-free survival, and it was an independent prognostic factor.

CONCLUSIONS.—

Small-size CTCs are a reliable prognostic indicator and a probable predictor of the severity of disease in NSCLC patients.

Bone Marrow Disseminated Tumor Cell Detection Is Beneficial for the Early Finding of Bone Metastasis and Prognosis

BACKGROUND

Disseminated tumor cells (DTCs) are thought to be the initiators of tumor recurrence and metastasis. However, based on the current imaging examination methods, early detection of DTCs is extremely difficult due to their small number and dormant state.

METHODS

We used the SE-iFISH approach to detect bone marrow DTCs (mDTCs) in patients with breast or prostate cancer, and compared it with various imaging examination methods to explore its role in predicting metastasis and prognosis.

RESULTS

Fifteen patients were enrolled in this study. Among them, 11 patients showed imaging-confirmed bone metastases in different sites of the body, of which seven patients had iliac mDTCs and signs of iliac bone metastases on imaging. For the remaining four patients, imaging confirmed that the bone metastatic foci were far from the ilium, but in one patient, mDTCs were detected in the ilium. Interestedly, iliac mDTCs were also detected in two out of four patients who had no sign of bone metastases on imaging. Furthermore, the epithelial marker, CK18, was ubiquitously expressed in mDTCs, but its expression was very low in peripheral circulating tumor cells (pCTCs). The Kaplan-Meier plot suggested that CK18+ mDTCs ≥ 5 was related to poor overall survival (OS) compared with that of CK18+ mDTCs < 5 in breast cancer patients (median OS: 22.1 vs. 46.9 months; log-rank, p = 0.035).

CONCLUSIONS

SE-iFISH examination for mDTCs is more sensitive than the conventional methods used for detecting bone metastases. mDTC detection facilitated the early finding of tumor cells in the bone marrow and ≥5 CK18+ mDTCs was associated with a poor prognosis in breast cancer patients.

Dysregulation of deubiquitination in breast cancer

Breast cancer (BC) is a highly frequent malignant tumor that poses a serious threat to women's health and has different molecular subtypes, histological subtypes, and biological features, which act by activating oncogenic factors and suppressing cancer inhibitors. The ubiquitin-proteasome system (UPS) is the main process contributing to protein degradation, and deubiquitinases (DUBs) are reverse enzymes that counteract this process. There is growing evidence that dysregulation of DUBs is involved in the occurrence of BC. Herein, we review recent research findings in BC-associated DUBs, describe their nature, classification, and functions, and discuss the potential mechanisms of DUB-related dysregulation in BC. Furthermore, we present the successful treatment of malignant cancer with DUB inhibitors, as well as analyzing the status of targeting aberrant DUBs in BC.

The deubiquitinase EIF3H promotes hepatocellular carcinoma progression by stabilizing OGT and inhibiting ferroptosis

Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal human malignancies, and with quite limited treatment alternatives. The proteasome is responsible for most of the protein degradation in eukaryotic cells and required for the maintenance of intracellular homeostasis. However, its potential role in HCC is largely unknown. In the current study, we identified eukaryotic translation initiation factor 3 subunit H (EIF3H), belonging to the JAB1/MPN/MOV34 (JAMM) superfamily, as a bona fide deubiquitylase of O-GlcNAc transferase (OGT) in HCC. We explored that EIF3H was positively associated with OGT in HCC and was related to the unfavorable prognosis. EIF3H could interact with, deubiquitylate, and stabilize OGT in a deubiquitylase-dependent manner. Specifically, EIF3H was associated with the GT domain of ERα via its JAB/MP domain, thus inhibiting the K48-linked ubiquitin chain on OGT. Besides, we demonstrated that the knockdown of EIF3H significantly reduced OGT protein expression, cell proliferation and invasion, and caused G1/S arrest of HCC. We also found that the deletion of EIF3H prompted ferroptosis in HCC cells. Finally, the effects of EIF3H depletion could be reversed by further OGT overexpression, implying that the OGT status is indispensable for EIF3H function in HCC carcinogenesis. In summary, our study described the oncogenic function of EIF3H and revealed an interesting post-translational mechanism between EIF3H, OGT, and ferroptosis in HCC. Targeting the EIF3H may be a promising approach in HCC. Video Abstract.

The Role of Liquid Biopsy in the Diagnosis and Prognosis of WHO Grade 4 Astrocytoma

Liquid biopsy, as a non-invasive diagnostic tool, has recently gained significant attention in the field of oncology. It involves the analysis of various biomarkers present in bodily fluids, such as blood or cerebrospinal fluid, to provide information about the underlying cancer. In the case of WHO grade 4 astrocytomas, liquid biopsy has the potential to significantly impact the diagnosis and prognosis of this aggressive malignant brain tumor. By detecting specific genetic mutations, such as IDH1 or EGFR, and monitoring levels of circulating tumor DNA, liquid biopsy can aid in the early detection and monitoring of disease progression. This innovative approach is gradually being acknowledged as a less invasive and cost-effective procedure for cancer diagnosis and management to improve patient outcomes and quality of life. Various kinds of biomarkers circulating in cerebrospinal fluid (CSF), such as circulating tumor cells (CTC) and different types of nucleic acids like cell-free DNA (cfDNA), cell-free RNA (ctRNA), and microRNAs (miRNA), have been identified. These biomarkers, which require dependable detection methods, are comparatively simple to obtain and allow for repeated measurements, making them significantly superior for disease monitoring. This review aims to compare the latest liquid biopsy analysis tools for both CSF and plasma in the central nervous system.

EIF3H stabilizes CCND1 to promotes intrahepatic cholangiocarcinoma progression via Wnt/β-catenin signaling

Cholangiocarcinoma (CCA) is a group of tumors that arise along the human biliary duct tree, ranking second in primary hepatic malignancies. Intrahepatic CCA (iCCA) represents about 10%-20% of CCAs. There is an increasing body of evidence suggesting that iCCAs' incidence and mortality have been increasing globally over the past few decades. In this study, we found that the EIF3H expression level in iCCA tissues was significantly increased compared to the adjacent non-cancerous tissues by immunohistochemistry analysis (IHC). A similar tendency of EIF3H mRNA and protein level was confirmed in iCCA cell lines using RT-qPCR and Western blot. EIF3H has been identified as a critical molecule that plays a pro-neoplasmic role in iCCA both in vivo and in vitro, such as proliferation, migration, and anti-apoptosis. Mechanistically, we found that EIF3H knockdown can promote the degradation of CCND1 and the proteolysis of CCND1 is mediated by ubiquitin-proteasome system (UPS). Thus, we come to the conclusion that EIF3H promotes proliferation and migration of iCCAs, inhibiting apoptosis of iCCA cells at the same time by stabilizing the CCND1 protein structure. Our findings provide insights into the mechanism of tumorigenesis role of EIF3H in iCCAs and a potential therapeutic target for iCCA treatment.

Genomic signatures define three subtypes of EGFR-mutant stage II-III non-small-cell lung cancer with distinct adjuvant therapy outcomes

The ADJUVANT study reported the comparative superiority of adjuvant gefitinib over chemotherapy in disease-free survival of resected EGFR-mutant stage II–IIIA non-small cell lung cancer (NSCLC). However, not all patients experienced favorable clinical outcomes with tyrosine kinase inhibitors (TKI), raising the necessity for further biomarker assessment. In this work, by comprehensive genomic profiling of 171 tumor tissues from the ADJUVANT trial, five predictive biomarkers are identified (TP53 exon4/5 mutations, RB1 alterations, and copy number gains of NKX2-1, CDK4, and MYC). Then we integrate them into the Multiple-gene INdex to Evaluate the Relative benefit of Various Adjuvant therapies (MINERVA) score, which categorizes patients into three subgroups with relative disease-free survival and overall survival benefits from either adjuvant gefitinib or chemotherapy (Highly TKI-Preferable, TKI-Preferable, and Chemotherapy-Preferable groups). This study demonstrates that predictive genomic signatures could potentially stratify resected EGFR-mutant NSCLC patients and provide precise guidance towards future personalized adjuvant therapy.

Adjuvant gefitinib improves outcomes in non-small cell lung cancer (NSCLC) patients compared to chemotherapy, but not in all cases. Here, the authors find genomic biomarkers of response to gefitinib in NSCLC patients from the ADJUVANT trial, and propose a score to stratify them by potential benefit from the treatment.

Integrated Analysis of Weighted Gene Coexpression Network Analysis Identifying Six Genes as Novel Biomarkers for Alzheimer's Disease

BACKGROUND

Alzheimer's disease (AD) is a chronic progressive neurodegenerative disease; however, there are no comprehensive therapeutic interventions. Therefore, this study is aimed at identifying novel molecular targets that may improve the diagnosis and treatment of patients with AD.

METHODS

In our study, GSE5281 microarray dataset from the GEO database was collected and screened for differential expression analysis. Genes with a P value of <0.05 and ∣log2FoldChange | >0.5 were considered differentially expressed genes (DEGs). We further profiled and identified AD-related coexpression genes using weighted gene coexpression network analysis (WGCNA). Functional enrichment analysis was performed to determine the characteristics and pathways of the key modules. We constructed an AD-related model based on hub genes by logistic regression and least absolute shrinkage and selection operator (LASSO) analyses, which was also verified by the receiver operating characteristic (ROC) curve.

RESULTS

In total, 4674 DEGs were identified. Nine distinct coexpression modules were identified via WGCNA; among these modules, the blue module showed the highest positive correlation with AD (r = 0.64, P = 3e - 20), and it was visualized by establishing a protein-protein interaction network. Moreover, this module was particularly enriched in "pathways of neurodegeneration-multiple diseases," "Alzheimer disease," "oxidative phosphorylation," and "proteasome." Sixteen genes were identified as hub genes and further submitted to a LASSO regression model, and six genes (EIF3H, RAD51C, FAM162A, BLVRA, ATP6V1H, and BRAF) were identified based on the model index. Additionally, we assessed the accuracy of the LASSO model by plotting an ROC curve (AUC = 0.940).

CONCLUSIONS

Using the WGCNA and LASSO models, our findings provide a better understanding of the role of biomarkers EIF3H, RAD51C, FAM162A, BLVRA, ATP6V1H, and BRAF and provide a basis for further studies on AD progression.

Circulating Tumor Cells for Glioma

Liquid biopsy has entered clinical applications for several cancers, including metastatic breast, prostate, and colorectal cancer for CTC enumeration and NSCLC for EGFR mutations in ctDNA, and has improved the individualized treatment of many cancers, but relatively little progress has been made in validating circulating biomarkers for brain malignancies. So far, data on circulating tumor cells about glioma are limited, the application of circulating tumor cells as biomarker for glioma patients has only just begun. This article reviews the research status and application prospects of circulating tumor cells in gliomas. Several detection methods and research results of circulating tumor cells about clinical research in gliomas are briefly discussed. The wide application prospect of circulating tumor cells in glioma deserves further exploration, and the research on more sensitive and convenient detection methods is necessary.

Eukaryotic translation initiation factors as promising targets in cancer therapy

The regulation of the translation of messenger RNA (mRNA) in eukaryotic cells is critical for gene expression, and occurs principally at the initiation phase which is mainly regulated by eukaryotic initiation factors (eIFs). eIFs are fundamental for the translation of mRNA and as such act as the primary targets of several signaling pathways to regulate gene expression. Mis-regulated mRNA expression is a common feature of tumorigenesis and the abnormal activity of eIF complexes triggered by upstream signaling pathways is detected in many tumors, leading to the selective translation of mRNA encoding proteins involved in tumorigenesis, metastasis, or resistance to anti-cancer drugs, and making eIFs a promising therapeutic target for various types of cancers. Here, we briefly outline our current understanding of the biology of eIFs, mainly focusing on the effects of several signaling pathways upon their functions and discuss their contributions to the initiation and progression of tumor growth. An overview of the progress in developing agents targeting the components of translation machinery for cancer treatment is also provided.

Digital PCR for the Analysis of MYC Copy Number Variation in Lung Cancer

Background

MYC (v-myc avian myelocytomatosis viral oncogene homolog) is one of the most frequently amplified genes in lung tumors. For the analysis of gene copy number variations, dPCR (digital PCR) is an appropriate tool. The aim of our study was the assessment of dPCR for the detection of MYC copy number variations (CNV) in lung tissue considering clinicopathological parameters. Material and Methods. MYC status was analyzed with dPCR as well as qPCR (quantitative PCR) using gDNA (genomic DNA) from tumor and adjacent nontumor tissue samples of lung cancer patients. The performance of MYC was estimated based on the AUC (area under curve).

Results

The results of the MYC amplification correlated significantly between dPCR and qPCR (r _S = 0.81, P < 0.0001). The MYC copy number revealed by dPCR showed statistically significant differences between tumor and adjacent nontumor tissues. For discrimination, a sensitivity of 43% and a specificity of 99% were calculated, representing 55 true-positive and one false-positive tests. No statistically significant differences could be observed for age, sex, and smoking status or the clinicopathological parameters (histological subtype, grade, and stage).

Conclusion

The results of the study show that dPCR is an accurate and reliable method for the determination of MYC copy numbers. The application is characterized by high specificity and moderate sensitivity. MYC amplification is a common event in lung cancer patients, and it is indicated that the determination of the MYC status might be useful in clinical diagnostics.

EIF3H promotes aggressiveness of esophageal squamous cell carcinoma by modulating Snail stability

Background

Overexpression of eukaryotic translation initiation factor 3H (EIF3H) predicts cancer progression and poor prognosis, but the mechanism underlying EIF3H as an oncogene remains unclear in esophageal squamous cell carcinoma (ESCC).

Methods

TCGA database and the immunohistochemistry (IHC) staining of ESCC samples were used and determined the upregulation of EIF3H in ESCC. CCK8 assay, colony formation assay and transwell assay were performed to examine the ability of cell proliferation and mobility in KYSE150 and KYSE510 cell lines with EIF3H overexpression or knockdown. Xenograft and tail-vein lung metastatic mouse models of KYSE150 cells with or without EIF3H knockdown were also used to confirm the function of EIF3H on tumor growth and metastasis in vivo. A potential substrate of EIF3H was screened by co-immunoprecipitation assay (co-IP) combined with mass spectrometry in HEK293T cells. Their interaction and co-localization were confirmed using reciprocal co-IP and immunofluorescence staining assay. The function of EIF3H on Snail ubiquitination and stability was demonstrated by the cycloheximide (CHX) pulse-chase assay and ubiquitination assay. The correlation of EIF3H and Snail in clinical ESCC samples was verified by IHC.

Results

We found that EIF3H is significantly upregulated in esophageal cancer and ectopic expression of EIF3H in ESCC cell lines promotes cell proliferation, colony formation, migration and invasion. Conversely, genetic inhibition of EIF3H represses ESCC tumor growth and metastasis in vitro and in vivo. Moreover, we identified EIF3H as a novel deubiquitinating enzyme of Snail. We demonstrated that EIF3H interacts with and stabilizes Snail through deubiquitination. Therefore, EIF3H could promote Snail-mediated EMT process in ESCC. In clinical ESCC samples, there is also a positive correlation between EIF3H and Snail expression.

Conclusions

Our study reveals a critical EIF3H-Snail signaling axis in tumor aggressiveness in ESCC and provides EIF3H as a promising biomarker for ESCC treatment.

EIF3H Orchestrates Hippo Pathway-Mediated Oncogenesis via Catalytic Control of YAP Stability

EIF3H is presumed to be a critical translational initiation factor. Here, our unbiased screening for tumor invasion factors has identified an unexpected role for EIF3H as a deubiquitylating enzyme that dictates breast tumor invasion and metastasis by modulating the Hippo-YAP pathway. EIF3H catalyzed YAP for deubiquitylation, resulting in its stabilization. Structure-based molecular modeling and simulations coupled with biochemical characterization unveiled a unique catalytic mechanism for EIF3H in dissociating polyubiquitin chains from YAP through a catalytic triad consisting of Asp90, Asp91, and Gln121. Trp119 and Tyr 140 on EIF3H directly interacted with the N-terminal region of YAP1, facilitating complex formation of EIF3H and YAP1 for YAP1 deubiquitylation. Stabilization of YAP via elevated EIF3H promoted tumor invasion and metastasis. Interference of EIF3H-mediated YAP deubiquitylation blocked YAP-induced tumor progression and metastasis in breast cancer models. These findings point to a critical role for YAP regulation by EIF3H in tumor invasion and metastasis. SIGNIFICANCE: This work demonstrates that EIF3H is a novel bona fide deubiquitinase that counteracts YAP ubiquitylation and proteolysis, and stabilization of YAP by EIF3H promotes tumor invasion and metastasis.

Intrinsic cell-penetrating activity propels Omomyc from proof of concept to viable anti-MYC therapy

Inhibiting MYC has long been considered unfeasible, although its key role in human cancers makes it a desirable target for therapeutic intervention. One reason for its perceived undruggability was the fear of catastrophic side effects in normal tissues. However, we previously designed a dominant-negative form of MYC called Omomyc and used its conditional transgenic expression to inhibit MYC function both in vitro and in vivo. MYC inhibition by Omomyc exerted a potent therapeutic impact in various mouse models of cancer, causing only mild, well-tolerated, and reversible side effects. Nevertheless, Omomyc has been so far considered only a proof of principle. In contrast with that preconceived notion, here, we show that the purified Omomyc mini-protein itself spontaneously penetrates into cancer cells and effectively interferes with MYC transcriptional activity therein. Efficacy of the Omomyc mini-protein in various experimental models of non-small cell lung cancer harboring different oncogenic mutation profiles establishes its therapeutic potential after both direct tissue delivery and systemic administration, providing evidence that the Omomyc mini-protein is an effective MYC inhibitor worthy of clinical development.

Overall survival prediction of non-small cell lung cancer by integrating microarray and clinical data with deep learning

Non-small cell lung cancer (NSCLC) is one of the most common lung cancers worldwide. Accurate prognostic stratification of NSCLC can become an important clinical reference when designing therapeutic strategies for cancer patients. With this clinical application in mind, we developed a deep neural network (DNN) combining heterogeneous data sources of gene expression and clinical data to accurately predict the overall survival of NSCLC patients. Based on microarray data from a cohort set (614 patients), seven well-known NSCLC biomarkers were used to group patients into biomarker- and biomarker+ subgroups. Then, by using a systems biology approach, prognosis relevance values (PRV) were then calculated to select eight additional novel prognostic gene biomarkers. Finally, the combined 15 biomarkers along with clinical data were then used to develop an integrative DNN via bimodal learning to predict the 5-year survival status of NSCLC patients with tremendously high accuracy (AUC: 0.8163, accuracy: 75.44%). Using the capability of deep learning, we believe that our prediction can be a promising index that helps oncologists and physicians develop personalized therapy and build the foundation of precision medicine in the future.

EIF3H interacts with PDCD4 enhancing lung adenocarcinoma cell metastasis

Lung adenocarcinoma (LUAD) is a common type of lung cancer characterized by a high incidence of local invasion and metastasis. Programmed cell death factor 4 (PDCD4) is a well-recognized tumor suppressor gene involved in LUAD, however its precise regulatory mechanism remains elusive. This is the first study to report an inverse regulatory relationship between PDCD4 and eukaryotic translation initiation factor 3 subunit H (EIF3H) in LUAD. Co-immunoprecipitation assays combined with mass spectrometry and immunofluorescent co-localization indicated that PDCD4 interacted with EIF3H. Overexpression of PDCD4 in LUAD cells reduced EIF3H mRNA and protein levels by suppressing c-Jun-induced EIF3H transcription. Further, an elevated level of EIF3H protein was found in LUAD tissues compared with para-cancerous normal lung tissues, and was found to be an unfavorable factor promoting LUAD pathogenesis. Moreover, the negative correlation between PDCD4 and EIF3H protein expression was confirmed in LUAD tissues. Functional analyses showed that EIF3H overexpression promoted LUAD cell migration and invasion in vitro as well as metastasis in nude mice by activating epithelial-mesenchymal transition (EMT) signaling. Conversely, EIF3H knockdown with small interfering RNAs reversed these changes in LUAD cells. Furthermore, we discovered that introduction of PDCD4 to EIF3H-overexpressing LUAD cells abrogated the function of EIF3H, reducing migration and invasion of LUAD cells by downregulating EMT signaling. Taken together, our findings identified a previously unknown negative regulation of PDCD4 on EIF3H and confirmed EIF3H as an oncogenic factor in LUAD by enhancing EMT signaling, which was abrogated by PDCD4.

CNVScope: Visually Exploring Copy Number Aberrations in Cancer Genomes

Motivation:

DNA copy number (CN) data are a fast-growing source of information used in basic and translational cancer research. Most CN segmentation data are presented without regard to the relationship between chromosomal regions. We offer both a toolkit to help scientists without programming experience visually explore the CN interactome and a package that constructs CN interactomes from publicly available data sets.

Results:

The CNVScope visualization, based on a publicly available neuroblastoma CN data set, clearly displays a distinct CN interaction in the region of the MYCN, a canonical frequent amplicon target in this cancer. Exploration of the data rapidly identified cis and trans events, including a strong anticorrelation between 11q loss and17q gain with the region of 11q loss bounded by the cell cycle regulator CCND1.

Availability:

The shiny application is readily available for use at http://cnvscope.nci.nih.gov/, and the package can be downloaded from CRAN (https://cran.r-project.org/package=CNVScope), where help pages and vignettes are located. A newer version is available on the GitHub site (https://github.com/jamesdalg/CNVScope/), which features an animated tutorial. The CNVScope package can be locally installed using instructions on the GitHub site for Windows and Macintosh systems. This CN analysis package also runs on a linux high-performance computing cluster, with options for multinode and multiprocessor analysis of CN variant data. The shiny application can be started using a single command (which will automatically install the public data package).

Eukaryotic translation initiation factor EIF3H potentiates gastric carcinoma cell proliferation

Eukaryotic translation initiation factor 3 subunit H (EIF3H) is required for the progression of several types of cancer. However, little is known about the function of EIF3H in gastric carcinoma. To address this issue, in the present study, we investigated EIF3H genetic alterations in and expression of EIF3H in gastric cancer tissue samples using cBioPortal and Oncomine databases. Endogenous EIF3H expression was knocked down in MGC80-3 and AGS gastric cancer cell lines by lentivirus-mediated RNA interference. We confirmed the knockdown efficiency by quantitative real-time PCR and western blotting and evaluated the effects of EIF3H silencing on cell proliferation of gastric cancer with the cell viability and colony formation assays and by flow cytometry. The OncoPrint of EIF3H generated using cBioPortal indicated that EIF3H genetic alterations (mutation, deletion and amplification) were present in two gastric cancer sample sets. The Oncomine analysis revealed that EIF3H mRNA level was upregulated in gastric cancer tissues. EIF3H knockdown inhibited cell proliferation and colony formation in gastric cancer lines and led to cell cycle arrest at the G0/G1 phase, while inducing apoptosis via up- and downregulation of pro- and anti-apoptotic factors, respectively. These results indicate that EIF3H can serve as a novel therapeutic target for the clinical treatment of gastric cancer.

The function and clinical significance of eIF3 in cancer

Abnormal regulation of gene expression is essential for tumorigenesis. Several studies indicate that regulation of oncogene expression and neoplastic transformation are controlled by subunits of eukaryotic translation initiation factors (eIFs). Eukaryotic translation initiation factor 3 (eIF3) is the largest (800 kDa) and the most complex mammalian initiation factor. It is composed of 13 non-identical polypeptides designated as eIF3a-m and plays a pivotal role in protein synthesis that bridges the 43S pre-initiation complex and eIF4F-bound mRNA. However, the functional roles of individual subunits are not yet very clear. This review presents on several of aberrant expressed eIF3 subunits which are detected in various human cancers and the associated mechanisms have been acknowledged or are still not sure. Finally, identifying novel targets and biomarkers for caner is of great importance in early diagnosis and treatment of cancer. eIF3 may be a novel target molecule in drug development for cancer treatment and prevention.

Eukaryotic translation initiation factor 3H suppression inhibits osteocarcinoma cell growth and tumorigenesis

Eukaryotic translation initiation factor 3H subunit (EIF3H) is a member of the EIF3 family and exhibits a central role in translation initiation in higher eukaryotes. Although EIF3H expression is upregulated in numerous tumour types, its potential role in human osteosarcoma (OS) has not yet been investigated. In the present study, it was demonstrated that EIF3H mRNA expression was upregulated in the human OS cell lines Saos-2 and U2OS. A recombinant lentivirus harbouring short hairpin RNA targeting EIF3H was constructed and successfully infected human OS Saos-2 and U2OS cells, resulting in 95% downregulated EIF3H expression compared with the respective control groups. Knockdown of EIF3H significantly inhibited the proliferation and colony formation of OS cells in vitro, and tumour growth in nude mice in vivo. Flow cytometry analysis revealed cell cycle arrest and promotion of apoptosis in OS cells with EIF3H knocked down. In conclusion, the results strongly suggested that EIF3H is a critical factor mediating the growth of OS cells and may represent a novel therapeutic target.

Up-regulation Of EIF3e Is Associated with The Progression of Esophageal Squamous Cell Carcinoma and Poor Prognosis in Patients

Introduction: Esophageal cancer is one of the most common malignant tumors in the world. Eukaryotic translation initiation factors 3e (eIF3e) makes a notable difference in the initiation of protein synthesis and tumor progression. However, the role of eIF3e in ESCC has not been revealed yet. This study aims to investigate the bio-functional and prognostic role of eIF3e in human ESCC tissues and cells. Methods: Immunohistochemical staining and Western blot were performed to detect the eIF3e expression in ESCC patients' tissues. The Kaplan-Meier product limit method and Cox regression were conducted to analyze the association between eIF3e expression, together with other related clinical/pathological features, and patients' prognosis. In the analysis of bio-functional role of eIF3e, CCK-8 and Transwell assay were performed to compare the proliferative and migrative ability after knockdown of eIF3e. Results: Up-regulation of eIF3e were demonstrated in ESCC tissues compared with the corresponding para-cancerous tissues. Overexpression of eIF3e was associated with deep tumor depth, lymph nodes metastasis, and advanced TNM stage. Importantly, the patients with high eIF3e expression suffered shorter overall and disease-free survival. Lymph node metastasis and histological grade served as independent prognostic predictors in patients' prognosis. Knockdown of eIF3e could inhibit cell proliferation and migration, in vitro. Conclusions: The eIF3e expression, or combined with other members of eIF3 complex, might predict poor prognosis of ESCC and serve as a potential breakthrough in the multimodality therapy of ESCC.

Elevated expression of eukaryotic translation initiation factor 3H is associated with proliferation, invasion and tumorigenicity in human hepatocellular carcinoma

Aim

We studied the role of eukaryotic translation initiation factor 3 subunit H (EIF3H) in hepatocellular carcinoma (HCC) progression.

Results

High EIF3H expression was observed in 50.23% patients. Upregulation of EIF3H is an independent predictor for greater rates of cancer recurrence and shorter overall survival in HCC patients. Knockdown of EIF3H expression in HCC cells promoted apoptosis, and inhibited cell growth, colony formation, migration, as well as xenograft growth. TGF-βand MAPK pathways are potentially targeted by EIF3H.

Methods

EIF3H mRNA expression was measured in HCC tissue samples and paired non-tumor samples (N=60) and results were validated in another dataset of 215 HCC patients. Then EIF3H expression and clinical outcomes were correlated. Malignant phenotypes were studied after EIF3H expression was knocked down with siRNA in HCC cell lines. EIF3H targeted pathways were identified by microarray analysis.

Conclusion

EIF3H is frequently upregulated and is an independent prognostic marker for HCC patients and EIF3H inhibition mitigates the malignant phenotype. Our data provide novel insight into the function of EIF3H in HCC progression, and suggest that EIF3H may be a potentially valuable biomarker for HCC.

Circulating tumor cell is a common property of brain glioma and promotes the monitoring system

Brain glioma is the most common primary intracranial tumor characterized by dismal prognosis and frequent recurrence, yet a real-time and reliable biological approach to monitor tumor response and progression is still lacking. Recently, few studies have reported that circulating tumor cells (CTCs) could be detected in glioblastoma multiform (GBM), providing the possibility of its application in brain glioma monitoring system. But its application limits still exist, because the detection rate of CTCs is still low and was exclusively limited to high- grade gliomas. Here, we adopted an advanced integrated cellular and molecular approach of SE-iFISH to detect CTCs in the peripheral blood (PB) of patients with 7 different subtypes of brain glioma, uncovering the direct evidences of glioma migration. We identified CTCs in the PB from 24 of 31 (77%) patients with glioma in all 7 subtypes. No statistical difference of CTC incidence and count was observed in different pathological subtypes or WHO grades of glioma. Clinical data revealed that CTCs, to some extent, was superior to MRI in monitoring the treatment response and differentiating radionecrosis from recurrence of glioma. Conclusively, CTCs is a common property of brain gliomas of various pathological subtypes, which has provided an ultimate paradox for the hypothesis “soil and seed”. It can be used to monitor the microenvironment of gliomas dynamically, which will be a meaningful complement to radiographic imaging.

Eukaryotic translation initiation factors and cancer

Recent technological advancements have shown tremendous mechanistic accomplishments in our understanding of the mechanism of messenger RNA translation in eukaryotic cells. Eukaryotic messenger RNA translation is very complex process that includes four phases (initiation, elongation, termination, and ribosome recycling) and diverse mechanisms involving protein and non-protein molecules. Translation regulation is principally achieved during initiation step of translation, which is organized by multiple eukaryotic translation initiation factors. Eukaryotic translation initiation factor proteins help in stabilizing the formation of the functional ribosome around the start codon and provide regulatory mechanisms in translation initiation. Dysregulated messenger RNA translation is a common feature of tumorigenesis. Various oncogenic and tumor suppressive genes affect/are affected by the translation machinery, making the components of the translation apparatus promising therapeutic targets for the novel anticancer drug. This review provides details on the role of eukaryotic translation initiation factors in messenger RNA translation initiation, their contribution to onset and progression of tumor, and how dysregulated eukaryotic translation initiation factors can be used as a target to treat carcinogenesis.

EIF3D promotes gallbladder cancer development by stabilizing GRK2 kinase and activating PI3K-AKT signaling pathway

Recent evidence suggests that dysregulated eIF3d expression may be critical in various genetic disorders as well as cancer. In this study, we observed that EIF3d levels increased in gallbladder cancer (GBC) samples compared with non-tumor tissue. High eIF3d levels were associated with advanced tumor stage and metastasis and were correlated with poor prognosis in 92 patients with GBC. Depletion of EIF3d in GBC cell lines inhibited cell proliferation, colony formation and metastasis and induced apoptosis and cell cycle arrest in vitro and in vivo. In contrast, ectopic expression of eIF3d had the opposite effects. Moreover, in this study, we revealed that a novel non-translational factor function of eIF3d mediated its protumoral effects. In details, eIF3d stabilizes GRK2 protein by blocking ubiquitin-mediated degradation, consequently activates PI3K/Akt signaling, and promotes GBC cell proliferation and migration. In conclusion, eIF3d promotes GBC progression mainly via eIF3d-GRK2-AKT axis and it may be used as a prognostic factor. The therapeutic targeting of eIF3d-GRK2 axis may be a potential treatment approach for GBC.

Enhanced detection and comprehensive in situ phenotypic characterization of circulating and disseminated heteroploid epithelial and glioma tumor cells

Conventional strategy of anti-EpCAM capture and immunostaining of cytokeratins (CKs) to detect circulating tumor cells (CTCs) is limited by highly heterogeneous and dynamic expression or absence of EpCAM and/or CKs in CTCs. In this study, a novel integrated cellular and molecular approach of subtraction enrichment (SE) and immunostaining-FISH (iFISH) was successfully developed. Both large or small size CTCs and circulating tumor microemboli (CTM) in various biofluid samples including cerebrospinal fluid (CSF) of cancer patients and patient-derived-xenograft (PDX) mouse models were efficiently enriched and comprehensively identified and characterized by SE-iFISH. Non-hematopoietic CTCs with heteroploid chromosome 8 were detected in 87–92% of lung, esophageal and gastric cancer patients. Characterization of CTCs performed by CK18-iFISH showed that CK18, the dual epithelial marker and tumor biomarker, was strong positive in only 14% of lung and 24% of esophageal CTCs, respectively. Unlike conventional methodologies restricted only to the large and/or both EpCAM and CK positive CTCs, SE-iFISH enables efficient enrichment and performing in situ phenotypic and karyotypic identification and characterization of the highly heterogeneous CTC subtypes classified by both chromosome ploidy and the expression of various tumor biomarkers. Each CTC subtype may possess distinct clinical significance relative to tumor metastasis, relapse, therapeutic drug sensitivity or resistance, etc.

Effects of TMEM9 gene on cell progression in hepatocellular carcinoma by RNA interference

Hepatocellular carcinoma (HCC) is a malignant tumor that has become a global health issue. The aim of the present study was to examine the role of transmembrane protein 9 (TMEM9) in cell progression, such as cell growth, cell cycle, cell metastasis of hepatoma cells, and to discuss the TMEM9 gene‑encoding protein as a potential therapy target of hepatoma. RT-qPCR was performed to examine TMEM9 expression in tumor tissues and adjacent tissues of patients with liver cancer. siRNAs were used to interfere TMEM9 in HepG2 and 7721 cells. A CCK-8 assay was performed to evaluate cell growth at 24, 48 and 72 h. Cell cycle and apoptosis were analyzed using flow cytometry. Transwell assays were used to determine cell invasion, migration and adhesion. The results showed that TMEM9 was expressed abnormally in liver cancers. TMEM9 expression increased significantly in the 34 examined patients. TMEM9 knockdown inhibited proliferation in the HepG2 and 7721 cells. The flow cytometric analysis revealed that TMEM9 knockdown by RNA interference resulted in G1 arrest and induced apoptosis. Cell invasion, migration and adhesion ability were also decreased. Western blotting indicated that expression of the cell cycle‑related proteins CDK1, EIF3H, RPL10L, S100A10, CCNB1 and CCNB2 was significantly decreased. In conclusion, TMEM9 plays an important role in the cell growth of hepatoma cells.

Nuclear distribution of eIF3g and its interacting nuclear proteins in breast cancer cells

Eukaryotic translation initiation factor 3 subunit g (eIF3g) is a core subunit of the eukaryotic translation initiation factor 3 complex, and is important in the initiation of translation. It is also involved in caspase-mediated apoptosis, and is upregulated in multidrug-resistant cancer cells. In the present study, the nuclear distribution of eIF3g was determined by performing co-immunoprecipitation of proteins that potentially interact with eIF3g in the nucleus. Mass spectrometry characterization showed that three proteins, heterogeneous nuclear ribonucleoprotein U/scaffold attachment factor A, HSZFP36/zinc finger protein 823 and β-actin, were among the candidate eIF3g-interacting proteins in the nucleus. The protein-protein interaction was further confirmed by cross-linking and a glutathione S-transferase pull-down assay, followed by western blotting. The co-localization of these proteins was determined by confocal microscopy. These findings provide novel insight into the possible functions of eIF3g in the nucleus and serves as an important first step for further investigation of the roles of eIF3g in cancer development.

Integrated EpCAM-independent subtraction enrichment and iFISH strategies to detect and classify disseminated and circulating tumors cells

Application of tumor cell surface adhesion molecule Anti-epithelial cell adhesion molecule (EpCAM)-dependent antibody capture, and intracellular cytokeratins (CKs)-dependent immunostaining strategies to detect disseminated or circulating tumor cells (DTCs or CTCs), is limited by highly heterogeneous and dynamic expression or absence of EpCAM and/or CKs in CTCs and DTCs, particularly in their capturing and identifying CTCs/DTCs shed from diverse types of solid tumor, thus being biased and restricted to the only both EpCAM and CK positive cancer cells. Moreover, heterogeneity of chromosome and tumor biomarker of CTCs/DTCs cannot be co-examined by conventional CK/EpCAM-dependent techniques. Accordingly, a novel integrated cellular and molecular approach of EpCAM-independent subtraction enrichment (SE) and immunostaining-FISH (iFISH(®)) has recently been successfully developed. SE-iFISH(®) is able to effectively enrich, comprehensively identify and characterize both large and small size non-hematopoietic heteroploid CTCs, DTCs and circulating tumor microemboli in various biofluid specimens of either cancer patients or patient-derived-xenograft mice. Obtained tumor cells, free of anti-EpCAM perturbing and hypotonic damage, are eligible for primary tumor cell culture as well as a series of downstream analyses. Highly heterogeneous CTCs and DTCs could be classified into subtypes by in situ phenotyping protein expression of various tumor biomarkers and karyotyping of chromosome aneuploidy performed by iFISH(®). Each CTC subtype may correlate with distinct clinical significance in terms of tumor metastasis, relapse, therapeutic drug sensitivity or resistance, respectively.

MYC and human telomerase gene (TERC) copy number gain in early-stage non-small cell lung cancer

OBJECTIVES

We investigated the frequency of MYC and TERC increased gene copy number (GCN) in early-stage non-small cell lung cancer (NSCLC) and evaluated the correlation of these genomic imbalances with clinicopathologic parameters and outcome.

MATERIALS AND METHODS

Tumor tissues were obtained from 113 resected NSCLCs. MYC and TERC GCNs were tested by fluorescence in situ hybridization (FISH) according to the University of Colorado Cancer Center (UCCC) criteria and based on the receiver operating characteristic (ROC) classification.

RESULTS

When UCCC criteria were applied, 41 (36%) cases for MYC and 41 (36%) cases for TERC were considered FISH-positive. MYC and TERC concurrent FISH-positive was observed in 12 cases (11%): 2 (17%) cases with gene amplification and 10 (83%) with high polysomy. By using the ROC analysis, high MYC (mean ≥ 2.83 copies/cell) and TERC (mean ≥ 2.65 copies/cell) GCNs were observed in 60 (53.1%) cases and 58 (51.3%) cases, respectively. High TERC GCN was associated with squamous cell carcinoma (SCC) histology (P=0.001). In univariate analysis, increased MYC GCN was associated with shorter overall survival (P=0.032 [UCCC criteria] or P=0.02 [ROC classification]), whereas high TERC GCN showed no association. In multivariate analysis including stage and age, high MYC GCN remained significantly associated with worse overall survival using both the UCCC criteria (P=0.02) and the ROC classification (P=0.008).

CONCLUSIONS

Our results confirm MYC as frequently amplified in early-stage NSCLC and increased MYC GCN as a strong predictor of worse survival. Increased TERC GCN does not have prognostic impact but has strong association with squamous histology.

The role of eIF3 and its individual subunits in cancer

Specific individual subunits of eIF3 are elevated or reduced in numerous human tumors, and their ectopic overexpression in immortal cells can result in malignant transformation. The structure and assembly of eIF3 and its role in promoting mRNA and methionyl-tRNAi binding to the ribosome during the initiation phase of protein synthesis are described. Methods employed to detect altered levels of eIF3 subunits in cancers are critically evaluated in order to conclude rigorously that such subunits may cause malignant transformation. Strong evidence is presented that the individual overexpression of eIF3 subunits 3a, 3b, 3c, 3h, 3i and 3m may cause malignant transformation, whereas underexpression of subunits 3e and 3f may cause a similar outcome. Possible mechanisms to explain the malignant phenotypes are examined. The involvement of eIF3 in cancer reinforces the view that translational control plays an important role in the regulation of cell proliferation, and provides new targets for the development of therapeutic agents. This article is part of a Special Issue entitled: Translation and Cancer.

WITHDRAWN: Enhanced Detection and Phenotypic and Karyotypic in Situ Characterization of Circulating Tumor Cells

Available online October 16, 2014 This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Int6/eIF3e is essential for proliferation and survival of human glioblastoma cells

Glioblastomas (GBM) are very aggressive and malignant brain tumors, with frequent relapses despite an appropriate treatment combining surgery, chemotherapy and radiotherapy. In GBM, hypoxia is a characteristic feature and activation of Hypoxia Inducible Factors (HIF-1α and HIF-2α) has been associated with resistance to anti-cancer therapeutics. Int6, also named eIF3e, is the “e” subunit of the translation initiation factor eIF3, and was identified as novel regulator of HIF-2α. Eukaryotic initiation factors (eIFs) are key factors regulating total protein synthesis, which controls cell growth, size and proliferation. The functional significance of Int6 and the effect of Int6/EIF3E gene silencing on human brain GBM has not yet been described and its role on the HIFs is unknown in glioma cells. In the present study, we show that Int6/eIF3e suppression affects cell proliferation, cell cycle and apoptosis of various GBM cells. We highlight that Int6 inhibition induces a diminution of proliferation through cell cycle arrest and increased apoptosis. Surprisingly, these phenotypes are independent of global cell translation inhibition and are accompanied by decreased HIF expression when Int6 is silenced. In conclusion, we demonstrate here that Int6/eIF3e is essential for proliferation and survival of GBM cells, presumably through modulation of the HIFs.

Eukaryotic translation initiation factors in cancer development and progression

Eukaryotic gene expression is a complicated process primarily regulated at the levels of gene transcription and mRNA translation. The latter involves four main steps: initiation, elongation, termination and recycling. Translation regulation is primarily achieved during initiation which is orchestrated by 12 currently known eukaryotic initiation factors (eIFs). Here, we review the current state of eIF research and present a concise summary of the various eIF subunits. As eIFs turned out to be critically implicated in different oncogenic processes the various eIF members and their contribution to onset and progression of cancer are featured.

Translation initiation factor eIF3b expression in human cancer and its role in tumor growth and lung colonization

PURPOSE

Discovery transcriptomic analyses suggest eukaryotic initiation factor 3b (eIF3b) is elevated in human bladder and prostate cancer, yet its role as a prognostic factor or its requirement in the maintenance or progression of human cancer is not established. Here, we determine the therapeutic potential of eIF3b by examining the clinical relevance of its expression in human cancer tissues and its role in experimental tumor models.

EXPERIMENTAL DESIGN

We examined mRNA expression of eIF3b in bladder (N = 317) and prostate (N = 566) tissue samples and protein expression by immunohistochemistry in 143 bladder tumor samples as a function of clinicopathologic features. The impact of eIF3b depletion by siRNA in human cancer lines was evaluated in regard to in vitro cell growth, cell cycle, migration, in vivo subcutaneous tumor growth, and lung colonization.

RESULTS

eIF3b mRNA expression correlated to tumor grade, stage, and survival in human bladder and prostate cancer. eIF3b protein expression stratified survival in human bladder cancer. eIF3b depletion reduced in vitro cancer cell growth; inhibited G1-S cell-cycle transition by changing protein but not RNA expression of cyclin A, E, Rb, and p27Kip1; inhibited migration; and disrupted actin cytoskeleton and focal adhesions. These changes were associated with decreased protein expression of integrin α5. Integrin α5 depletion phenocopied effects observed with eIF3b. eIF3b-depleted bladder cancer cells formed fewer subcutaneous tumors that grew more slowly and had reduced lung colonization.

CONCLUSION

eIF3b expression relates to human bladder and prostate cancer prognosis, is required for tumor growth, and thus a candidate therapeutic target.

Diphtheria toxin-epidermal growth factor fusion protein DAB389EGF for the treatment of bladder cancer

PURPOSE

The novel fusion protein, DAB(389)EGF, is composed of both the catalytic and the translocation domains of diphtheria toxin that are fused to the human EGF, providing a targeting and a toxicity component. We tested DAB(389)EGF for antitumor activity in both in vitro and in vivo urinary bladder cancer models.

EXPERIMENTAL DESIGN

Human bladder cancer lines were treated with DAB(389)EGF and assessed for growth inhibition and clonogenic suppression. Using 6- to 8-week-old female athymic nude mice implanted orthotopically with HTB9 cells, DAB(389)EGF was administered intravesically twice weekly for 2 weeks. The response of the luciferase-expressing HTB9 cells was monitored via bioluminescence as the primary endpoint.

RESULTS

Treatment response with DAB(389)EGF was specific and robust, with an IC(50) ranging from 0.5 to 15 ng/mL in eight tested bladder cancer cell lines, but greater than 50 ng/mL in the EGF receptor (EGFR)-negative H520 control cell line. Simulating short-duration intravesical therapy used clinically, a 2-hour treatment exposure of DAB(389)EGF (10 ng/mL) produced clonogenic suppression in three selected bladder cancer cell lines. In vivo, luciferase activity was suppressed in five of six mice treated with DAB(389)EGF [70 μL (1 ng/μL) per mouse], as compared with only one of six mice treated with a control diphtheria toxin (DT) fusion protein. Histologic assessment of tumor clearance correlated with the bioluminescent changes observed with DAB(389)EGF treatment. Immunocompetent mice treated with intravesical DAB(389)EGF did not show any nonspecific systemic toxicity.

CONCLUSIONS

The intravesical delivery of targeted toxin fusion proteins is a novel treatment approach for non-muscle-invasive urinary bladder cancer. With appropriate targeting, the treatments are effective and well-tolerated in vivo.

Polymorphisms on 8q24 are associated with lung cancer risk and survival in Han Chinese

Chromosome 8q24 is commonly amplified in many types of cancer, particularly lung cancer. Polymorphisms in this region are associated with risk of different cancers. To investigate the relationship between three single nucleotide polymorphisms (SNPs) (rs1447295, rs16901979 and rs6983267) on 8q24 and lung cancer risk, we conducted an association study in two Han Chinese populations: one population was from Zhejiang Province (576 case patients and 576 control subjects), whereas the other was from Fujian Province (576 case patients and 576 control subjects). We found that rs6983267 was significantly associated with an increased risk of lung cancer in both populations. Compared with the TT genotype, the GG genotype was associated with a significant 1.555-fold increased risk of lung cancer [95% confidence interval (CI) 1.218-1.986, P = 4.0×10(-4)]. This effect was more pronounced in never-smokers [odds ratio (OR) = 2.366, 95% CI 1.605-3.488, P = 1.4×10(-5)]. Analyses stratified by histology revealed that rs6983267 GG genotype was most associated with patients with other histological types (OR = 3.012, 95% CI 1.675-5.417, P = 2.3×10(-4)). The AA genotype of rs1447295 was associated with increased risk for adenocarcinoma compared with the CC genotype (OR = 2.260, 95% CI 1.174-4.353, P = 0.015). Furthermore, the GG genotype of rs6983267 was associated with worse survival in the Zhejiang population (hazard ratio (HR) = 1.646, 95% CI 1.099-2.464, P = 0.016). No association was observed for rs16901979. These results suggest that genetic variations on 8q24 may play significant roles in the development and progression of lung cancer.

RNA interference-mediated silencing of eukaryotic translation initiation factor 3, subunit B (EIF3B) gene expression inhibits proliferation of colon cancer cells

Background

A key factor underlying the control of the cellular growth, size and proliferation involves the regulation of the total protein synthesis. Most often, the initial stages of mRNA translation are rate limiting, which involves a group of eukaryotic translation initiation factors (EIFs). Research advances focused on the inhibition of their expression and activity hold the key to the initiation and progression of tumor and tumor prognosis.

Method

We performed RNA interference (RNAi) with the lentivirus vector system to silence the EIF3B gene using the colon cancer cell strain SW1116. The negative control included the normal target cells infected with the negative control virus whereas the knockdown cells included the normal target cells transfected with the RNAi target virus. We tested the inhibition resulting from the decreased expression of EIF3B gene on the proliferation rate of SW1116 cells, including the cell cycle, apoptosis and clonability.

Results

Compared with the negative control, the impact of EIF3B gene expression in SW1116 cells on the levels of mRNA and protein in the knockdown group, was significantly inhibited (P <0.01). Furthermore, the cell proliferation rate and clonability were also significantly inhibited (P <0.01). The apoptosis rate increased significantly (P <0.05). A significant decrease in the number of cells in the G1 phase (P <0.01) and significant increases in S (P <0.01) and G2 phases (P <0.05) were observed.

Conclusions

The silencing of EIF3B gene expression inhibits the proliferation of colon cancer cells.

Essential gene profiles in breast, pancreatic, and ovarian cancer cells

Genomic analyses are yielding a host of new information on the multiple genetic abnormalities associated with specific types of cancer. A comprehensive description of cancer-associated genetic abnormalities can improve our ability to classify tumors into clinically relevant subgroups and, on occasion, identify mutant genes that drive the cancer phenotype ("drivers"). More often, though, the functional significance of cancer-associated mutations is difficult to discern. Genome-wide pooled short hairpin RNA (shRNA) screens enable global identification of the genes essential for cancer cell survival and proliferation, providing a "functional genomic" map of human cancer to complement genomic studies. Using a lentiviral shRNA library targeting ~16,000 genes and a newly developed, dynamic scoring approach, we identified essential gene profiles in 72 breast, pancreatic, and ovarian cancer cell lines. Integrating our results with current and future genomic data should facilitate the systematic identification of drivers, unanticipated synthetic lethal relationships, and functional vulnerabilities of these tumor types.

SIGNIFICANCE

This study presents a resource of genome-scale, pooled shRNA screens for 72 breast, pancreatic, and ovarian cancer cell lines that will serve as a functional complement to genomics data, facilitate construction of essential gene profiles, help uncover synthetic lethal relationships, and identify uncharacterized genetic vulnerabilities in these tumor types.

SIGNIFICANCE

This study presents a resource of genome-scale, pooled shRNA screens for 72 breast, pancreatic, and ovarian cancer cell lines that will serve as a functional complement to genomics data, facilitate construction of essential gene profiles, help uncover synthetic lethal relationships, and identify uncharacterized genetic vulnerabilities in these tumor types.

Translational control gone awry: a new mechanism of tumorigenesis and novel targets of cancer treatments

Translational control is one of primary regulation mechanisms of gene expression. Eukaryotic translational control mainly occurs at the initiation step, the speed-limiting step, which involves more than ten translation initiation factors [eIFs (eukaryotic initiation factors)]. Changing the level or function of these eIFs results in abnormal translation of specific mRNAs and consequently abnormal growth of cells that leads to human diseases, including cancer. Accumulating evidence from recent studies showed that the expression of many eIFs was associated with malignant transformation, cancer prognosis, as well as gene expression regulation. In the present paper, we perform a critical review of recent advances in understanding the role and mechanism of eIF action in translational control and cancer as well as the possibility of targeting eIFs for therapeutic development.

Translational control in cancer

Remarkable progress has been made in defining a new understanding of the role of mRNA translation and protein synthesis in human cancer. Translational control is a crucial component of cancer development and progression, directing both global control of protein synthesis and selective translation of specific mRNAs that promote tumour cell survival, angiogenesis, transformation, invasion and metastasis. Translational control of cancer is multifaceted, involving alterations in translation factor levels and activities unique to different types of cancers, disease stages and the tumour microenvironment. Several clinical efforts are underway to target specific components of the translation apparatus or unique mRNA translation elements for cancer therapeutics.

Induction of E-cadherin in lung cancer and interaction with growth suppression by histone deacetylase inhibition

INTRODUCTION

Loss of E-cadherin confers a poor prognosis in lung cancer patients and is associated with in vitro resistance to endothelial growth factor receptor inhibitors. Zinc finger E box-binding homeobox (ZEB)-1, the predominant transcriptional suppressor of E-cadherin in lung tumor lines, recruits histone deacetylases (HDACs) as co-repressors.

METHODS

NSCLC cell lines were treated with HDAC inhibitors and analyzed for E-cadherin induction, growth inhibition and apoptosis. National Cancer Institute-H157 cells expressing ectopic E-cadherin were tested for tumorigenicity in murine xenografts.

RESULTS

We found that treatment with MS-275, compared to vorinostat (SAHA), valproic acid or trichostatin A, was most effective in E-cadherin up-regulation and persistence in non-small cell lung cancers. As with other tumor types and HDAC inhibitors, MS-275 inhibited growth and induced apoptosis. Importantly, blocking E-cadherin induction by short hairpin RNA resulted in less inhibition by MS-275, implicating the epithelial to mesenchymal phenotype process as a contributing factor. In contrast to H460 and H661, H157 cells were resistant to E-cadherin up-regulation by HDAC inhibitors. However, E-cadherin was restored, in a synergistic manner, by combined knockdown of ZEB-1 and ZEB-2. In addition, H157 cells stably transfected with E-cadherin were markedly attenuated in their tumor forming ability. Lastly, combining MS-275 with the microtubule stabilizing agent, paclitaxel, or 17-(allylamino)-17-demethoxygeldanamycin, a heat shock protein 90 inhibitor, resulted in synergistic growth inhibition. Since MS-275 has no reported activity against HDAC6, which regulates both microtubule and heat shock protein 90 functions, other mechanisms of synergy are anticipated.

CONCLUSIONS

These results support the role of ZEB proteins and HDAC inhibitors in the pathogenesis and treatment of lung cancer.

Chromosomal and genomic changes in lung cancer

Lung cancer is a complex spectrum of diseases characterized by extensive genomic instability, which can be detected among both histological subtypes and different foci within a tumor. Conventional and cutting edge investigative technologies have uncovered scores of genomic changes in individual specimens that have been used to characterize specific molecular subtypes. Oncogenes with predominant roles in lung cancer include EGFR, MYC and RAS family members, PIK3CA, NKX2-1 and ALK; tumor suppressor genes include TP53, RB1, CDKN2, and a cluster of genes mapped at 3p. MicroRNA regulators also have been linked to lung cancer. The functional role of the recurrent genomic changes in lung tumors has been explored, which has led to a better understanding of cell growth, differentiation and apoptotic pathways. Additionally, this knowledge has supported the development of novel therapeutics and translational tools for selection of patients for personalized therapy.

The regulation of protein synthesis in cancer

Translational control of cancer is a multifaceted process, involving alterations in translation factor levels and activities that are unique to the different types of cancers and the different stages of disease. Translational alterations in cancer include adaptations of the tumor itself, of the tumor microenvironment, an integral component in disease, and adaptations that occur as cancer progresses from development to local disease and ultimately to metastatic disease. Adaptations include the overexpression and increased activity of specific translation factors, the physical or functional loss of translation regulatory components, increased production of ribosomes, selective mRNA translation, and alteration of signal transduction pathways to permit unfettered activation of protein synthesis. There is intense clinical interest to capitalize on the emerging new understanding of translational control in cancer by targeting specific components of the translation apparatus that are altered in disease for the development of specific cancer therapeutics. Clinical trial data are nascent but encouraging, suggesting that translational control constitutes an important new area for drug development in human cancer.