LIN28B and Let-7 in Diffuse Midline Glioma: A Review.

Diffuse midline glioma (DMG) is the most lethal of all childhood cancers. DMGs are driven by histone-tail-mutation-mediated epigenetic dysregulation and partner mutations in genes controlling proliferation and migration. One result of this epigenetic and genetic landscape is the overexpression of LIN28B RNA binding protein. In other systems, LIN28B has been shown to prevent let-7 microRNA biogenesis; however, let-7, when available, faithfully suppresses tumorigenic pathways and induces cellular maturation by preventing the translation of numerous oncogenes. Here, we review the current literature on LIN28A/B and the let-7 family and describe their role in gliomagenesis. Future research is then recommended, with a focus on the mechanisms of LIN28B overexpression and localization in DMG.

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population.

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications.

Docetaxel targets aggressive methylation profiles and serves as a radiosensitizer in high-risk meningiomas.

BACKGROUND: Meningioma is the most common primary intracranial tumor in adults. A subset of these tumors recur and invade the brain, even after surgery and radiation, resulting in significant disability. There is currently no standard-of-care chemotherapy for meningiomas. As genomic DNA methylation profiling can prognostically stratify these lesions, we sought to determine whether any existing chemotherapies might be effective against meningiomas with high-risk methylation profiles. METHODS: A previously published dataset of meningioma methylation profiles was used to screen for clinically significant CpG methylation events and associated cellular pathways. Based on these results, patient-derived meningioma cell lines were used to test candidate drugs in vitro and in vivo, including efficacy in conjunction with radiotherapy. RESULTS: We identified 981 genes for which methylation of mapped CpG sites was related to progression-free survival in meningiomas. Associated molecular pathways were cross-referenced with FDA-approved cancer drugs, which nominated Docetaxel as a promising candidate for further preclinical analyses. Docetaxel arrested growth in 17 meningioma cell sources, representing all tumor grades, with a clinically favorable IC50 values ranging from 0.3 nM to 10.7 mM. The inhibitory effects of this medication scaled with tumor doubling time, with maximal benefit in fast-growing lesions. The combination of Docetaxel and radiation therapy increased markers of apoptosis and double-stranded DNA breaks, and extended the survival of mice engrafted with meningioma cells relative to either modality alone. CONCLUSIONS: Global patterns of DNA methylation may be informative for the selection of chemotherapies against meningiomas, and existing drugs may enhance radiation sensitivity in high-risk cases.

Histone tail analysis reveals H3K36me2 and H4K16ac as epigenetic signatures of diffuse intrinsic pontine glioma.

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) is an aggressive pediatric brainstem tumor. Most DIPGs harbor a histone H3 mutation, which alters histone post-translational modification (PTM) states and transcription. Here, we employed quantitative proteomic analysis to elucidate the impact of the H3.3K27M mutation, as well as radiation and bromodomain inhibition (BRDi) with JQ1, on DIPG PTM profiles. METHODS: We performed targeted mass spectrometry on H3.3K27M mutant and wild-type tissues (n = 12) and cell lines (n = 7). RESULTS: We found 29.2 and 26.4% of total H3.3K27 peptides were H3.3K27M in mutant DIPG tumor cell lines and tissue specimens, respectively. Significant differences in modification states were observed in H3.3K27M specimens, including at H3K27, H3K36, and H4K16. In addition, H3.3K27me1 and H4K16ac were the most significantly distinct modifications in H3.3K27M mutant tumors, relative to wild-type. Further, H3.3K36me2 was the most abundant co-occurring modification on the H3.3K27M mutant peptide in DIPG tissue, while H4K16ac was the most acetylated residue. Radiation treatment caused changes in PTM abundance in vitro, including increased H3K9me3. JQ1 treatment resulted in increased mono- and di-methylation of H3.1K27, H3.3K27, H3.3K36 and H4K20 in vitro. CONCLUSION: Taken together, our findings provide insight into the effects of the H3K27M mutation on histone modification states and response to treatment, and suggest that H3K36me2 and H4K16ac may represent unique tumor epigenetic signatures for targeted DIPG therapy.

Tuberculosis infection and lung adenocarcinoma: Mendelian randomization and pathway analysis of genome-wide association study data from never-smoking Asian women.

We investigated whether genetic susceptibility to tuberculosis (TB) influences lung adenocarcinoma development among never-smokers using TB genome-wide association study (GWAS) results within the Female Lung Cancer Consortium in Asia. Pathway analysis with the adaptive rank truncated product method was used to assess the association between a TB-related gene-set and lung adenocarcinoma using GWAS data from 5512 lung adenocarcinoma cases and 6277 controls. The gene-set consisted of 31 genes containing known/suggestive associations with genetic variants from previous TB-GWAS. Subsequently, we followed-up with Mendelian Randomization to evaluate the association between TB and lung adenocarcinoma using three genome-wide significant variants from previous TB-GWAS in East Asians. The TB-related gene-set was associated with lung adenocarcinoma (p = 0.016). Additionally, the Mendelian Randomization showed an association between TB and lung adenocarcinoma (OR = 1.31, 95% CI: 1.03, 1.66, p = 0.027). Our findings support TB as a causal risk factor for lung cancer development among never-smoking Asian women.

Therapeutic targeting of tumor-associated myeloid cells synergizes with radiation therapy for glioblastoma.

Tumor-associated myeloid cells (TAMCs) are key drivers of immunosuppression in the tumor microenvironment, which profoundly impedes the clinical response to immune-dependent and conventional therapeutic modalities. As a hallmark of glioblastoma (GBM), TAMCs are massively recruited to reach up to 50% of the brain tumor mass. Therefore, they have recently been recognized as an appealing therapeutic target to blunt immunosuppression in GBM with the hope of maximizing the clinical outcome of antitumor therapies. Here we report a nano-immunotherapy approach capable of actively targeting TAMCs in vivo. As we found that programmed death-ligand 1 (PD-L1) is highly expressed on glioma-associated TAMCs, we rationally designed a lipid nanoparticle (LNP) formulation surface-functionalized with an anti-PD-L1 therapeutic antibody (αPD-L1). We demonstrated that this system (αPD-L1-LNP) enabled effective and specific delivery of therapeutic payload to TAMCs. Specifically, encapsulation of dinaciclib, a cyclin-dependent kinase inhibitor, into PD-L1-targeted LNPs led to a robust depletion of TAMCs and an attenuation of their immunosuppressive functions. Importantly, the delivery efficiency of PD-L1-targeted LNPs was robustly enhanced in the context of radiation therapy (RT) owing to the RT-induced up-regulation of PD-L1 on glioma-infiltrating TAMCs. Accordingly, RT combined with our nano-immunotherapy led to dramatically extended survival of mice in 2 syngeneic glioma models, GL261 and CT2A. The high targeting efficiency of αPD-L1-LNP to human TAMCs from GBM patients further validated the clinical relevance. Thus, this study establishes a therapeutic approach with immense potential to improve the clinical response in the treatment of GBM and warrants a rapid translation into clinical practice.

Impact of menopausal status and HER-2/neu protein on efficacy of EGFR-TKI in EGFR mutant patients with non-small cell lung cancer.

Clinical studies have confirmed epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) used in lung cancer patients with EGFR mutations can obtain a better result, but still part of the patients with poor efficacy. EGFR mutation is highly related to female, nonsmoking and adenocarcinoma. Thus, we hypothesize that estrogen and circulating HER-2/neu protein might influence the efficacy of EGFR-TKIs in EGFR mutant patients with non-small cell lung cancer. HER-2/neu expression level of 357 eligible patients in its peripheral serum was determined using ELISA. The median progression-free survival (PFS) in five groups (premenopausal group, perimenopause group, peri to postmenopausal group, postmenopausal group and control group) was statistically difference (P = 0.025). Premenopausal group could predict the efficacy of EGFR-TKI (HR = 2.45, 95% CI = 1.42-4.23, P = 0.001). No statistical significance was found in median overall survival (OS) among five groups. Optimal diagnostic cut off value of HER-2/neu was set at 47.5 ng/ml, with P = 0.0607. As the cutoff value to 47.5 ng/ml division, concentrations and menopausal status was of no significant difference (P = 0.874). PFS of the group below 47.5 ng/ml was significantly longer than that of the group over 47.5 ng/ml (P = 0.000). HER-2/neu concentration was positively correlated with optimal efficacy (P = 0.042). HER-2/neu concentration over than 47.5 ng/ml was a risk factor of EGFR-TKI prognosis. Premenopausal status is an independent predictor of EGFR-TKI curative effect and circulating HER-2/neu protein is an independent prognostic factor in patients with advanced NSCLC.

Caspase-11-mediated endothelial pyroptosis underlies endotoxemia-induced lung injury.

Acute lung injury is a leading cause of death in bacterial sepsis due to the wholesale destruction of the lung endothelial barrier, which results in protein-rich lung edema, influx of proinflammatory leukocytes, and intractable hypoxemia. Pyroptosis is a form of programmed lytic cell death that is triggered by inflammatory caspases, but little is known about its role in EC death and acute lung injury. Here, we show that systemic exposure to the bacterial endotoxin lipopolysaccharide (LPS) causes severe endothelial pyroptosis that is mediated by the inflammatory caspases, human caspases 4/5 in human ECs, or the murine homolog caspase-11 in mice in vivo. In caspase-11-deficient mice, BM transplantation with WT hematopoietic cells did not abrogate endotoxemia-induced acute lung injury, indicating a central role for nonhematopoietic caspase-11 in endotoxemia. Additionally, conditional deletion of caspase-11 in ECs reduced endotoxemia-induced lung edema, neutrophil accumulation, and death. These results establish the requisite role of endothelial pyroptosis in endotoxemic tissue injury and suggest that endothelial inflammatory caspases are an important therapeutic target for acute lung injury.

Association between GWAS-identified lung adenocarcinoma susceptibility loci and EGFR mutations in never-smoking Asian women, and comparison with findings from Western populations.

To evaluate associations by EGFR mutation status for lung adenocarcinoma risk among never-smoking Asian women, we conducted a meta-analysis of 11 loci previously identified in genome-wide association studies (GWAS). Genotyping in an additional 10,780 never-smoking cases and 10,938 never-smoking controls from Asia confirmed associations with eight known single nucleotide polymorphisms (SNPs). Two new signals were observed at genome-wide significance (P < 5 × 10-8), namely, rs7216064 (17q24.3, BPTF), for overall lung adenocarcinoma risk, and rs3817963 (6p21.3, BTNL2) which is specific to cases with EGFR mutations. In further sub-analyses by EGFR status, rs9387478 (ROS1/DCBLD1) and rs2179920 (HLA-DPB1) showed stronger estimated associations in EGFR-positive compared to EGFR-negative cases. Comparison of the overall associations with published results in Western populations revealed that the majority of these findings were distinct, underscoring the importance of distinct contributing factors for smoking and non-smoking lung cancer. Our results extend the catalogue of regions associated with lung adenocarcinoma in non-smoking Asian women and highlight the importance of how the germline could inform risk for specific tumour mutation patterns, which could have important translational implications.

PAR1 Scaffolds TGFßRII to Downregulate TGF-ß Signaling and Activate ESC Differentiation to Endothelial Cells.

We studied the function of the G-protein-coupled receptor PAR1 in mediating the differentiation of mouse embryonic stem cells (mESCs) to endothelial cells (ECs) that are capable of inducing neovascularization. We observed that either deletion or activation of PAR1 suppressed mouse embryonic stem cell (mESC) differentiation to ECs and neovascularization in mice. This was mediated by induction of TGFßRII/TGFßRI interaction, forming an active complex, which in turn induced SMAD2 phosphorylation. Inhibition of TGF-ß signaling in PAR1-deficient mESCs restored the EC differentiation potential of mESCs. Thus, PAR1 in its inactive unligated state functions as a scaffold for TGFßRII to downregulate TGF-ß signaling, and thereby promote ESC transition to functional ECs. The PAR1 scaffold function in ESCs is an essential mechanism for dampening TGF-ß signaling and regulating ESC differentiation.

Blockade of Hedgehog Signaling Synergistically Increases Sensitivity to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-Small-Cell Lung Cancer Cell Lines.

Aberrant activation of the hedgehog (Hh) signaling pathway has been implicated in the epithelial-to-mesenchymal transition (EMT) and cancer stem-like cell (CSC) maintenance; both processes can result in tumor progression and treatment resistance in several types of human cancer. Hh cooperates with the epidermal growth factor receptor (EGFR) signaling pathway in embryogenesis. We found that the Hh signaling pathway was silenced in EGFR-TKI-sensitive non-small-cell lung cancer (NSCLC) cells, while it was inappropriately activated in EGFR-TKI-resistant NSCLC cells, accompanied by EMT induction and ABCG2 overexpression. Upregulation of Hh signaling through extrinsic SHH exposure downregulated E-cadherin expression and elevated Snail and ABCG2 expression, resulting in gefitinib tolerance (P < 0.001) in EGFR-TKI-sensitive cells. Blockade of the Hh signaling pathway using the SMO antagonist SANT-1 restored E-cadherin expression and downregulate Snail and ABCG2 in EGFR-TKI-resistant cells. A combination of SANT-1 and gefitinib markedly inhibited tumorigenesis and proliferation in EGFR-TKI-resistant cells (P < 0.001). These findings indicate that hyperactivity of Hh signaling resulted in EGFR-TKI resistance, by EMT introduction and ABCG2 upregulation, and blockade of Hh signaling synergistically increased sensitivity to EGFR-TKIs in primary and secondary resistant NSCLC cells. E-cadherin expression may be a potential biomarker of the suitability of the combined application of an Hh inhibitor and EGFR-TKIs in EGFR-TKI-resistant NSCLCs.

Polymorphism of rs9387478 correlates with overall survival in female nonsmoking patients with lung cancer.

BACKGROUND: Our previous study identified rs9387478 as a new susceptibility locus associated with lung cancer in never-smoking women in Asia; however, the clinical and prognostic significance of this finding is not known. METHODS: We analyzed the relationship between the rs9387478 single nucleotide polymorphism and i) clinical parameters and ii) overall survival time in 505 female nonsmoking lung cancer patients, using the chi-square test and Kaplan-Meier analysis with the log-rank test, respectively. We further established the epidermal growth factor receptor (EGFR) mutation status and assessed its association with rs9387478 genotypes as well as the efficacy of EGFR tyrosine kinase inhibitors. RESULTS: The frequency of the AA genotype was significantly higher in the EGFR-mutation-negative group than in the EGFR-mutation-positive group (32% vs. 16%, χ2 = 13.025, p = 0.011). Patients with the CC genotype had a better overall survival time than patients with the AA/AC genotype (median survival time: 54.2 vs. 32.9 months, χ2 = 4.593, p = 0.032). The distribution of rs9387478 genotypes differed according to the clinical disease stage. CONCLUSIONS: This study indicates that the rs9387478 genotype was associated with overall survival in nonsmoking female patients with lung cancer, although it was not significant after adjusting for multiple testing. The identification of the location of the rs9387478 single nucleotide polymorphism in the genomic interval containing the DCBLD1 and ROS1 genes, together with the finding that the rs9387478 polymorphism correlates with EGFR mutation status, may have important implications for therapeutic approaches targeting EGFR or ROS1 in patients with lung cancer.

miR-23a binds to p53 and enhances its association with miR-128 promoter.

Apoptosis plays an important role in cardiac pathology, but the molecular mechanism by which apoptosis regulated remains largely elusive. Here, we report that miR-23a promotes the apoptotic effect of p53 in cardiomyocytes. Our results showed that miR-23a promotes apoptosis induced by oxidative stress. In exploring the molecular mechanism by which miR-23a promotes apoptosis, we found that it sensitized the effect of p53 on miR-128 regulation. It promoted the association of p53 to the promoter region of miR-128, and enhanced the transcriptional activation of p53 on miR-128 expression. miR-128 can downregulate prohibitin expression, and subsequently promote apoptosis. Our data provides novel evidence revealing that miR-23a can stimulate transcriptional activity of p53.

Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for Thirteen Cancer Types.

BACKGROUND: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. METHODS: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. RESULTS: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. CONCLUSION: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.

Single nucleotide polymorphisms of MAGE-A3 gene and its clinical implications in Chinese patients with non-small cell lung cancer (NSCLC).

BACKGROUND: Available study revealed advanced tumors have a higher expression rate of MAGE-A3 gene which has a lot of single nucleotide polymorphism (SNP) loci with polymorphisms. This study aimed to analyze the allele frequency of SNP loci in MAGE-A3 gene and investigate the relationship between MAGE-A3 gene polymorphisms and clinical factors. METHODS: Tumor samples of a cohort of 191 NSCLC patients were collected. EGFR mRNA expression were detected by qRT-PCR. SNPs in whole length of MAGE-A3 gene were detected by direct sequencing. Frequencies of the SNPs were correlated to gene expression, mutation status of EGFR and clinical factors. RESULTS: Sequencing analysis confirmed that allele frequencies of genotypes on SNP loci rs5970360, rs5925210, rs5970361, rs5925211 and rs35123853 were CC (0.681)/CT (0.319), CC (0.660)/CG (0.340), CC (0.681)/CA (0.319), AA (0.984)/AT (0.016) and GG (1.000)/GA (0.000), respectively, which were different from the frequencies and genotypes of MAGE-A3 in SNP database. Chi-square tests showed the EGFR mRNA expression level had significant correlation with the genotypes of SNP loci rs5970360 and rs5925210. But all frequencies of each MAGE-A3 SNPs were not found significantly different between EGFR mutant and wild type patients. MAGE-A3 gene polymorphisms had no significant effects on survival of NSCLC patients. CONCLUSIONS: Chinese patients with NSCLC had different SNP patterns of MAGE-A3 in comparison with those in international SNP database. These MAGE-A3 SNP loci might have not prognostic significance. MAGE-A3 SNP loci rs5970360 and rs5925210 might be predictive for EGFR mRNA expression levels and helpful to the selection of patients for epidermal growth factor receptor (EGFR) targeted immunotherapy.

Genetic variants associated with longer telomere length are associated with increased lung cancer risk among never-smoking women in Asia: a report from the female lung cancer consortium in Asia.

Recent evidence from several relatively small nested case-control studies in prospective cohorts shows an association between longer telomere length measured phenotypically in peripheral white blood cell (WBC) DNA and increased lung cancer risk. We sought to further explore this relationship by examining a panel of seven telomere-length associated genetic variants in a large study of 5,457 never-smoking female Asian lung cancer cases and 4,493 never-smoking female Asian controls using data from a previously reported genome-wide association study. Using a group of 1,536 individuals with phenotypically measured telomere length in WBCs in the prospective Shanghai Women's Health study, we demonstrated the utility of a genetic risk score (GRS) of seven telomere-length associated variants to predict telomere length in an Asian population. We then found that GRSs used as instrumental variables to predict longer telomere length were associated with increased lung cancer risk (OR = 1.51 (95% CI = 1.34-1.69) for upper vs. lower quartile of the weighted GRS, p value = 4.54 × 10(-14) ) even after removing rs2736100 (p value = 4.81 × 10(-3) ), a SNP in the TERT locus robustly associated with lung cancer risk in prior association studies. Stratified analyses suggested the effect of the telomere-associated GRS is strongest among younger individuals. We found no difference in GRS effect between adenocarcinoma and squamous cell subtypes. Our results indicate that a genetic background that favors longer telomere length may increase lung cancer risk, which is consistent with earlier prospective studies relating longer telomere length with increased lung cancer risk.

MicroRNA-21 Down-regulates Rb1 Expression by Targeting PDCD4 in Retinoblastoma.

Retinoblastoma (RB) is a children's ocular cancer caused by mutated retinoblastoma 1 (Rb1) gene on both alleles. Rb1 and other related genes could be regulated by microRNAs (miRNA) via complementarily pairing with their target sites. MicroRNA-21 (miR-21) possesses the oncogenic potential to target several tumor suppressor genes, including PDCD4, and regulates tumor progression and metastasis. However, the mechanism of how miR-21 regulates PDCD4 is poorly understood in RB. We investigated the expression of miRNAs in RB cell lines and identified that miR-21 is one of the most deregulated miRNAs in RB. Using qRT-PCR, we verified the expression level of several miRNAs identified by independent microarray assays, and analyzed miRNA expression patterns in three RB cell lines, including Weri-Rb1, Y79 and RB355. We found that miR-19b, -21, -26a, -195 and -222 were highly expressed in all three cell lines, suggesting their potential role in RB tumorigenesis. Using the TargetScan program, we identified a list of potential target genes of these miRNAs, of which PDCD4 is one the targets of miR-21. In this study, we focused on the regulatory mechanism of miR-21 on PDCD4 in RB. We demonstrated an inverse correlation between miR-21 and PDCD4 expression in Weri-Rb1 and Y79 cells. These data suggest that miR-21 down-regulates Rb1 by targeting PDCD4 tumor suppressor. Therefore, miR-21 could serve as a therapeutic target for retinoblastoma.

miR-638 mediated regulation of BRCA1 affects DNA repair and sensitivity to UV and cisplatin in triple-negative breast cancer.

INTRODUCTION: Triple-negative breast cancer (TNBC) represents 15 to 20% of all types of breast cancer; however, it accounts for a large number of metastatic cases and deaths, and there is still no effective treatment. The deregulation of microRNAs (miRNAs) in breast cancer has been widely reported. We previously identified that miR-638 was one of the most deregulated miRNAs in breast cancer progression. Bioinformatics analysis revealed that miR-638 directly targets BRCA1. The aim of this study was to investigate the role of miR-638 in breast cancer prognosis and treatment. METHODS: Formalin-fixed, paraffin-embedded (FFPE) breast cancer samples were microdissected into normal epithelial and invasive ductal carcinoma (IDC) cells, and total RNA was isolated. Several breast cancer cell lines were used for the functional analysis. miR-638 target genes were identified by TARGETSCAN-VERT 6.2 and miRanda. The expression of miR-638 and its target genes was analyzed by real-time qRT-PCR and Western blotting. Dual-luciferase reporter assay was employed to confirm the specificity of miR-638 target genes. The biological function of miR-638 was analyzed by MTT chemosensitivity, matrigel invasion and host cell reactivation assays. RESULTS: The expression of miR-638 was decreased in IDC tissue samples compared to their adjacent normal controls. The decreased miR-638 expression was more prevalent in non-TNBC compared with TNBC cases. miR-638 expression was significantly downregulated in breast cancer cell lines compared to the immortalized MCF-10A epithelial cells. BRCA1 was predicted as one of the direct targets of miR-638, which was subsequently confirmed by dual-luciferase reporter assay. Forced expression of miR-638 resulted in a significantly reduced proliferation rate as well as decreased invasive ability in TNBC cells. Furthermore, miR-638 overexpression increased sensitivity to DNA-damaging agents, ultraviolet (UV) and cisplatin, but not to 5-fluorouracil (5-FU) and epirubicin exposure in TNBC cells. Host cell reactivation assays showed that miR-638 reduced DNA repair capability in post UV/cisplatin-exposed TNBC cells. The reduced proliferation, invasive ability, and DNA repair capabilities are associated with downregulated BRCA1 expression. CONCLUSIONS: Our findings suggest that miR-638 plays an important role in TNBC progression via BRCA1 deregulation. Therefore, miR-638 might serve as a potential prognostic biomarker and therapeutic target for breast cancer.

Lung cancer treatment disparities in China: a question in need of an answer.

BACKGROUND: Substantial progress has been made in the treatment of malignancies in the People's Republic of China in recent years. The goal of this study was to identify the extent to which national treatment guidelines are being used to customize patient care in lung cancer and to analyze the reasons for treatment disparities. METHODS: Patient characteristics and treatments were investigated retrospectively for the period from October 2004 to January 2013 using the outpatient database of the Guangdong Lung Cancer Institute (GLCI) in China. RESULTS: A total of 2,535 outpatients with lung cancer were studied in this retrospective analysis. The treatment disparity was 45.3%. Overall, 20.6% of patients with stage I non-small cell lung cancer (NSCLC) were overtreated, and 20.1% of stage II patients were undertreated. Only 19.6% of stage IIIA patients and 30.7% of stage IIIB patients underwent the recommended combination of chemotherapy and radiotherapy, respectively. For advanced NSCLC, the greatest treatment disparity appeared in the second-line setting and beyond. Patients who were positive for epidermal growth factor receptor (EGFR) and receiving EGFR tyrosine kinase inhibitors experienced significant prolongation of survival compared with patients who were EGFR negative or whose EGFR mutation status was unknown (hazard ratio: 0.79; p = .037). The treatment disparities were significantly larger among patients aged younger than 65 years and in patients from developing regions compared with patients aged 65 years and older and from developed regions, respectively (p < .001, p = .046). The difference in treatment disparity was statistically significant between GLCI and other hospitals (p < .001). CONCLUSION: This retrospective study of a large number of patients from an outpatient oncology database demonstrated large disparities in the treatment of lung cancer in China. It is important to develop a new guideline for recommendations that are based on resource classification.

Detecting the spectrum of multigene mutations in non-small cell lung cancer by Snapshot assay.

As molecular targets continue to be identified and more targeted inhibitors are developed for personalized treatment of non-small cell lung cancer (NSCLC), multigene mutation determination will be needed for routine oncology practice and for clinical trials. In this study, we evaluated the sensitivity and specificity of multigene mutation testing by using the Snapshot assay in NSCLC. We retrospectively reviewed a cohort of 110 consecutive NSCLC specimens for which epidermal growth factor receptor (EGFR) mutation testing was performed between November 2011 and December 2011 using Sanger sequencing. Using the Snapshot assay, mutation statuses were detected for EGFR, Kirsten rate sarcoma viral oncogene homolog (KRAS), phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA), v-Raf murine sarcoma viral oncogene homolog B1 (BRAF), v-ras neuroblastoma viral oncogene homolog (NRAS), dual specificity mitogen activated protein kinase kinase 1 (MEK1), phosphatase and tensin homolog (PTEN), and human epidermal growth factor receptor 2 (HER2) in patient specimens and cell line DNA. Snapshot data were compared to Sanger sequencing data. Of the 110 samples, 51 (46.4%) harbored at least one mutation. The mutation frequency in adenocarcinoma specimens was 55.6%, and the frequencies of EGFR, KRAS, PIK3CA, PTEN, and MEK1 mutations were 35.5%, 9.1%, 3.6%, 0.9%, and 0.9%, respectively. No mutation was found in the HER2, NRAS, or BRAF genes. Three of the 51 mutant samples harbored double mutations: two PIK3CA mutations coexisted with KRAS or EGFR mutations, and another KRAS mutation coexisted with a PTEN mutation. Among the 110 samples, 47 were surgical specimens, 60 were biopsy specimens, and 3 were cytological specimens; the corresponding mutation frequencies were 51.1%, 41.7%, and 66.7%, respectively (P = 0.532). Compared to Sanger sequencing, Snapshot specificity was 98.4% and sensitivity was 100% (positive predictive value, 97.9%; negative predictive value, 100%). The Snapshot assay is a sensitive and easily customized assay for multigene mutation testing in clinical practice.