Metastasis risk stratification and response prediction through dynamic viable circulating tumor cell counts for rectal cancer in a neoadjuvant setting.

PURPOSE: Distant metastasis (DM) and neoadjuvant treatment response prediction remain critical challenges in the management of locally advanced rectal cancer (LARC). The aim of this study was to investigate the clinical relevance of viable circulating tumor cells (CTCs) for DM or response in patients with LARC in a neoadjuvant setting. METHODS: The detection of viable CTCs at different stages of treatment was planned for consecutive patients from a prospective trial. The Kaplan-Meier method, Cox proportional hazards model, and logistic regression model were utilized to analyze factors associated with DM or pathological complete response (pCR) and clinical complete response (cCR). RESULTS: Between December 2016 and July 2018, peripheral blood samples from 83 patients were collected before any treatment (median follow-up time, 49.3 months). CTCs were present in 76 of 83 patients (91.6%) at baseline, and more than three CTCs detected in the blood sample was considered high risk. Only the CTC risk group was significantly associated with 3-year metastasis-free survival (MFS) (high risk vs. low risk, 57.1% (95% CI, 41.6-72.6) vs. 78.3% (95% CI, 65.8-90.8), p = 0.018, log-rank test). When all the important variables were entered into the Cox model, the CTC risk group remained the only significant independent factor for DM (hazard ratio (HR), 2.74; 95% CI, 1.17-6.45, p = 0.021). The pCR and continuous cCR rates were higher in patients with a decreased number of CTCs of more than one after radiotherapy (HR, 4.00; 95% CI, 1.09-14.71, P = 0.037). CONCLUSIONS: The dynamic detection of viable CTCs may strengthen pretreatment risk assessment and postradiotherapy decision making for LARC. This observation requires further validation in a prospective study.

Copy number changes of 4-gene set may predict early relapse in advanced epithelial ovarian cancer after initial platinum-paclitaxel chemotherapy.

For advanced epithelial ovarian cancer (EOC), time to recurrence (TTR) is an important indicator to gauge the therapeutic efficacy of postoperative adjuvant chemotherapy. Our objective was to determine the genes that could potentially distinguish patients with short versus long TTR after initial administration of platinum-paclitaxel combination chemotherapy in advanced EOC. Tumor samples of 159 patients were obtained during the primary cytoreduction. Array comparative genomic hybridization (CGH) was carried with genomic DNA from 17 EOC samples (8 with TTR > 15 months and 9 with TTR ≤ 6 months) to screen candidate gene set, copy-number changes (CNC) of which were significantly different between early and late relapse cases. Seventeen candidate genes were identified by array CGH. The analysis of consistency between real-time PCR and array CGH revealed that 4 genes displayed consistent results, namely GSTT1, ISG20L1, STARD5 and FREM1. In a 142-case validation set, CNC of 4 candidate genes was evaluated and verified by real-time PCR. Sixty five point five percent of the patients were correctly divided into early (TTR ≤ 10 months) and late (TTR > 10 months) recurrent group by CNC of the 4 genes using discriminant analysis. The results showed that CNC of 4-gene set could potentially determine early (TTR ≤ 10 months) or late relapse (TTR > 10 months) after initial platinum-paclitaxel combination chemotherapy in advanced EOC.

Genomic alterations with impact on survival in esophageal squamous cell carcinoma identified by array comparative genomic hybridization.

Risk assessment of esophageal squamous cell carcinoma (ESCC) is currently based on clinicopathological parameters. To identify genomic markers that can predict overall survival in ESCC, we performed array comparative genomic hybridization (array CGH) on a screening set of 35 tumor samples from ESCC patients. Prognosis association of the genes selected on the basis of the array CGH results was further validated by real-time PCR in two independent sample sets (n = 151 and 84). Genomic analysis revealed seven high-level amplifications and two homozygous deletions. Gain of 11q13.2 and loss of 7q34 and 18q21.1-q23 were associated with poor outcome. Gain of 11q13.2 was an independent prognostic factor and was selected for further validation. In both validation sets of samples, copy number increase of CPT1A in 11q13.2 was correlated with short overall survival (P = 0.015, n = 151 and P = 0.044, n = 84). Multivariate analysis confirmed that CPT1A gain provided prognostic information in ESCC (HR, 1.643; 95% CI: 1.076-2.509; P = 0.022; HR, 2.488; 95% CI: 1.235-5.013; P = 0.011). Immunohistochemistry showed significant correlation between strong expression of CPT1A protein and poor outcome of ESCC patients (P = 0.018, n = 73). Our data suggest that gain of CPT1A may be a candidate prognostic factor.

[DNA microarrays-based microRNA expression profiles derived from formalin-fixed paraffin-embedded tissue blocks of squammous cell carcinoma of larynx].

OBJECTIVE: To establish DNA microarrays-based microRNA (miRNA) expression profiles of squamous cell carcinoma of larynx, using archived formalin-fixed paraffin-embedded tissue blocks, and to screen out and identify the differentially expressed miRNAs associated with the biological characteristics of this malignant disease. METHODS: Total RNA was prepared from the formalin-fixed paraffin-embedded tissue blocks. After quality identification and fluorescent labeling, the RNA samples were hybridized with the Agilent human miRNA microarrays which contains 723 probes for human miRNAs. The data was processed with the softwares GeneSpring GX and R-Project. RESULTS: From the formalin-fixed paraffin-embedded tumor blocks collected, 24 RNA samples were obtained with the quality accorded to the requirement of miRNA microarray analysis, and both the hybridization and consequent data processing were accomplished. A total of 319 miRNAs were identified and among them 96 were detected in all the 24 formalin-fixed paraffin-embedded blocks of laryngeal carcinoma; and 5 differentially expressed miRNAs (false discovery rate < 0.05) were found to be associated significantly with the lymphatic metastasis of laryngeal squamous cell carcinoma (P < 0.05), including miR-23a(*), miR-28-5p, miR-15a, miR-16 and miR-425. CONCLUSIONS: Histopathological archives of well-annotated formalin-fixed paraffin-embedded tissue specimens are the valuable resources for miRNA study including to collect RNA samples for miRNA microarray analysis. A panel of differentially expressed miRNAs (miR-23a(*), miR-28-5p, miR-15a, miR-16 and miR-425) derived from the miRNA expression profile may serve as the potential molecular biomarkers for the prediction of metastasis development in laryngeal squamous cell carcinoma.

Integrative analysis and validation of robust gene signature in lung cancer.

We studied robust gene signature (RGS) in lung cancer by using an approach of integrating a highly diverse collection of cancer genome-wide datasets, which were six public microarray datasets, one pair of Suppression Subtractive Hybridization EST library, one pair of Serial Analysis of Gene Expression (SAGE) experiments, and 191 Loss of Heterozygosity (LOH) reports obtained from 388 publications. Among the 109 RGS genes identified from our study, 14 of the 15 reported differentially expressed genes (DEGs) based on literature verification were consistent with our predictions. Out of the remaining 94 genes that were not reported as DEGs in lung cancer by any publication, we randomly picked eight and verified their expression in lung cancer versus normal tissues by semi-quantitative RT-PCR amplification, and all showed consistent expression pattern with our findings. System assessment analysis revealed that our integrative method had an accuracy of 95% and a correlation coefficients value of 0.92.

[Regulatory effect of Smad7 gene on MAPK signal pathway in malignant transformation of immortalized human bronchial epithelial BEP2D cells].

BACKGROUND & OBJECTIVE: Smad7 is an inhibitor of transforming growth factor-beta (TGF-beta) signal pathway. TGF-beta could induce the expression of several genes through activating SMAD and ras/MEK/ERK pathways. This study was to determine whether Smad7 is involved in regulating mitogen-activated protein kinase (MAPK) signal pathway with TGF-beta in malignant transformation of human bronchial epithelial BEP2D cells. METHODS: Immortalized BEP2D cells and malignant BERP35T2 cells were co-transfected with full-length Smad7 cDNA constructed pCISmad7.neo or Smad7 siRNA, transactivator vector pTet-Elk or pTet-Jun, and reporter vector pTRE-Luc, and stimulated with TGF-beta. The regulatory effect of Smad7 on MAPK signal pathway was investigated by standard luciferase assay. RESULTS: In BEP2D cells, when treated with TGF-beta1, phosphorylated activities of Elk and Jun were up-regulated (P(Elk)=0.033, P(Jun)=0.016); after co-transfection of Elk or Jun with pCISmad7.neo, phosphorylated activity of Elk was increased, and that of Jun was decreased (P(Elk)=0.017, P(Jun)=0.028); after co-transfection of Elk or Jun with Smad7 siRNA, phosphorylated activity of Elk was decreased, and that of Jun was increased (P(Elk)=0.018, P(Jun)=0.005). In BERP35T2 cells, when treated with TGF-beta1, phosphorylated activity of Elk was up-regulated (P=0.006); after co-transfection of Elk and Smad7 siRNA, phosphorylated activity of Elk was decreased (P=0.000); no activity of Jun was detected in BERP35T2 cells. CONCLUSIONS: In the process of malignant transformation of BEP2D cells, the intervention of Smad7 in MAPK signal pathway leads to the activity imbalance between extracellular signal-related protein kinase (ERK) and c-Jun NH2-terminal kinase (JNK), which in turn promotes cell proliferation. All these could contribute to further malignant transformation of these cells.

[Effect of overexpression of Smad7 gene on cell proliferation].

OBJECTIVE: To study the effect of overexpression of Smad7 gene on cell proliferation in human bronchial epithelial cell lines. METHODS: Human bronchial epithelial cell lines, BEP2D and BERP35T2 cells, were cotransfected with the mammalian expression vectors PCISmad7.neo and pMyc-SEAP, the latter was ac-myc cis-acting enhancer element fused with alkaline phosphatase (SEAP) reporter gene. Expression of c-myc, p15 and p21 mRNA was detected by RT-PCR before and after stable transfection of Smad7 into BEP2D and BERP35T2 cells in order to study the regulation of TGF-beta-mediated growth inhibition. RESULTS: After BEP2D and BERP35T2 cells transfected with Smad7, the transcriptional activity of c-myc was significantly increased. Smad7 overexpressing cells showed upregulation of c-myc expression and downregulation of p15 and p21 expression, which contributed to the loss of TGF-beta responses in these cells. CONCLUSION: Overexpression of Smad7 may facilitate cell proliferation by antagonizing TGF-beta-mediated antiproliferative gene responses.

[Expression and clinical significance of methylthioadenosine phosphorylase gene in patients with non-small cell lung cancer].

OBJECTIVE: To investigate the change of expression of methylthioadenosine phosphorylase (MTAP) gene in patients with non-small cell lung cancer and its clinical significance. METHODS: Thirty fresh samples of cancer with adjacent tissues were collected from 15 patients with lung cancer, 12 males and 8 females, aged 53.6 (38 approximately 72), 8 with squamous cell carcinoma and 7 with adenocarcinoma. The expressions of MTAP mRNA and of its protein were analyzed by RT-PCR and Western blotting. RESULTS: In 11 out of the 15 tumor samples (73.3%) MTAP mRNA was not expressed or expressed only after the additional 5 circulations. However, the MTAP mRNA expression rate was 93.3% (14/15) in the adjacent tissues. The result in the 11 samples with none or low MTAP mRNA expression was confirmed by Western blot analysis. The low expression rates were not significantly different between lung adenocarcinoma and squamous cell carcinoma. But the low expression rate of MTAP in intermediate and poorly differentiated lung cancer was significantly higher than that in well-differentiated cancer. CONCLUSION: The low expression or loss of MTAP gene may be relevant closely to the differentiation degree in lung cancer.

[Proteomics-based identification of Maspin differential expression in bronchial epithelial immortalized cells and malignant transformation cells].

BACKGROUND & OBJECTIVE: Maspin, a serepin inhibitor, plays a key role in tumor growth and metastasis. The aim of this study was to identify the differential expression of Maspin in malignant transformation process of bronchial epithelial cells by proteomics. METHODS: Functional proteomics analysis of Maspin on bronchial epithelial immortalized cells and malignant transformation cells was carried out using immobilized pH gradient (IPG) two-dimensional electrophoresis, peptide mass fingerprinting (PMF), and post source decay (PSD) of bio-mass spectrometry. RESULTS: Nearly 1500 expressed proteins profile on bronchial epithelial immortalized cells and malignant transformation cells were obtained in the range of MW 14.4-94 kDa, PI 3-10. Image analysis showed that Maspin was down-regulated in malignant transformation cells compared with that in immortalized cells. Northern blot analysis showed that the mRNA abundance of Maspin in malignant transformation cells was much lower than that in immortalized cells. CONCLUSION: Alteration expression of Maspin at transcription and translation levels might be involved in carcinogenesis of lung.

[Regulation of Smad7 gene by TGF-beta 1 in process of malignant transformation].

BACKGROUND & OBJECTIVE: Escape from transforming growth factor-beta(TGF-beta)-induced inhibition of growth and proliferation may contribute to tumorigenesis. Smad7 is inhibitory Smads of TGF-beta s signal transduction pathway and prevents TGF-beta signaling. The disorder of Smad7 may lead to the perturbation of TGF-beta signal pathway. In this study, The authors analyzed the expression of Smad7 mRNA and the regulation of Smad7 gene by TGF-beta 1 in the process of malignant transformation of BEP2D cells to investigate the mechanism of cells malignant transformation. METHODS: Cells were cultured and stimulated with TGF-beta 1 followed by RNA extraction. Purified total RNA from TGF-beta 1 treated cells and untreated controls and performed an expression analysis with a human Smad7-specific probe applying Northern blot. As a loading control for the Northern experiment, the membrane was hybridized with a human glyceraldehyde-3-phosphate dehydrogenase(GAPDH) probe. Proteins were extracted from BEP2D and BERP35T-2 cells, then perform Western blot to examine the expression level of TGF-beta 1. RESULTS: Before stimulation with TGF-beta 1, the expression level of Smad7 in the BERP35T-2 cells were higher than that in the BEP2D cells. When stimulated with TGF-beta 1, Smad7 expression levels was upregulated evidently in BEP2D cells, but not significant in BERP35T-2 cells. The expression level of endogenetic TGF-beta 1, BERP35T-2 cells was a little higher than BEP2D cells. CONCLUSION: Over expression of Smad7 mRNA and down-regulation of the cells' responsiveness to TGF-beta 1 in human lung cancer cell line which induced by alpha-particles should be one of the mechanism of radiation induced lung cancer.