Hypothyroidism reduces the risk of lung cancer through oxidative stress response and the PI3K/Akt signaling pathway: An RNA-seq and Mendelian randomization study.

Hypothyroidism has been suggested to play a role in tumor progression. However, the causal association between hypothyroidism and lung cancer remains unknow. To elucidate the potential association between hypothyroidism and lung cancer risk, we employ a Mendelian randomization (MR) approach. MR was performed to analyze pooled data from the International Lung Cancer Consortium (11,348 cases and 15,861 controls; European ancestry) to determine the causal relationship between hypothyroidism and lung cancer. We used 36, 83, and 14 single nucleotide polymorphisms as instrumental variables for hypothyroidism/myxoedema, hypothyroidism, and exercise, respectively. We further investigated the mechanisms involved in transcriptome analysis using data from The Cancer Genome Atlas and Genotype-Tissue Expression database. We conducted an initial validation of intermediary factor using a two-step MR analysis. Genetically predicted hypothyroidism was significantly related to the risk of overall lung cancer, specifically the risk of lung squamous cell cancer (LSCC) but not with the risk of lung adenocarcinoma (LUAD) as assessed using the inverse-variance weighted (IVM) method. A similar causal association was found between hypothyroidism/myxoedema and the risk of lung cancer, LSCC, and LUAD. Transcriptome analysis showed that genes associated with hypothyroidism, lung cancer, and LSCC were enriched in the PI3K/Akt signaling pathway and oxidative stress response. However, genes related to hypothyroidism and LUAD did not exhibit enrichment in these pathways. Hypothyroidism was significantly associated with strenuous sports or other exercises. Moreover, genetically predicted exercise was significantly related to the risk of overall lung cancer, and LSCC, but not LUAD. We detected no horizontal pleiotropy using the MR-PRESSO and MR Egger regression intercept. Hypothyroidism was causally associated with a lower risk of lung cancer, and these effects might be mediated by the oxidative stress response and the PI3K/Akt signaling pathway. Therefore, our study suggests that the potential factors and viable etiologies of hypothyroidism that contributed to lung cancer risk deserve further investigation.

Macrophage migration inhibitory factor may contribute to the occurrence of multiple primary lung adenocarcinomas.

BACKGROUND: This study aimed to identify the key genes involved in the development of multiple primary lung cancers. METHODS: Differential expression analysis was performed, followed by comparing the infiltration levels of 22 immune cell types between multiple and single primary lung adenocarcinomas. Marker genes for epithelial cells with different proportions between the two types of lung adenocarcinomas were identified. The common genes between the marker genes and differentially expressed genes were identified. Finally, the effects of the key genes were tested on the in vitro proliferation, migration and morphology. RESULTS: The infiltration levels of helper follicular T cells, resting NK cells, activated NK cells, M2 macrophages and resting mast cells were higher in the patients with multiple than in those with single primary lung adenocarcinomas. A total of 1553 differentially expressed genes and 4414 marker genes of epithelial cells were identified. Logistic regression analysis was performed on the 164 resulting genes. The macrophage migration inhibitory factor expression was positively associated with the occurrence of multiple primary lung adenocarcinomas. Moreover, its signalling pathway was the key pathway among the epithelial cells and multiple and single primary lung adenocarcinoma cells, and it was upregulated in lung adenocarcinoma cells. It also increased the expression of lung cancer markers, including NES and CA125, induced morphological changes in alveolar epithelial type II cells, and promoted their proliferation, migration and invasion. CONCLUSIONS: Multiple and single primary lung adenocarcinomas have different tumour immune microenvironments, and migration inhibitory factor may be a key factor in the occurrence of multiple primary lung adenocarcinomas.

Methylation of N6 adenosine-related long noncoding RNA: effects on prognosis and treatment in 'driver-gene-negative' lung adenocarcinoma.

The improvement of treatment for patients with 'driver-gene-negative' lung adenocarcinoma (LUAD) remains a critical problem to be solved. We aimed to explore the role of methylation of N6 adenosine (m6A)-related long noncoding RNA (lncRNA) in stratifying 'driver-gene-negative' LUAD risk. Patients negative for mutations in EGFR, KRAS, BRAF, HER2, MET, ALK, RET, and ROS1 were identified as 'driver-gene-negative' cases. RNA sequencing was performed in 46 paired tumors and adjacent normal tissues from patients with 'driver-gene-negative' LUAD. Twenty-three m6A regulators and relevant lncRNAs were identified using Pearson's correlation analysis. K-means cluster analysis was used to stratify patients, and a prognostic nomogram was developed. The CIBERSORT and pRRophetic algorithms were employed to quantify the immune microenvironment and chemosensitivity. We identified two clusters highly consistent with the prognosis based on their unique expression profiles for 46 m6AlncRNAs. A risk model constructed from nine m6A lncRNAs could stratify patients into high- and low-risk groups with promising predictive power (C-index = 0.824), and the risk score was an independent prognostic factor. The clusters and risk models were closely related to immune characteristics and chemosensitivity. Additional pan-cancer analysis using the nine m6AlncRNAs showed that the expression of DIO3 opposite strand upstream RNA (DIO3OS) is closely related to the immune/stromal score and tumor stemness in a variety of cancers. Our results show that m6AlncRNAs are a reliable prognostic tool and can aid treatment decision-making in 'driver-gene-negative' LUAD. DIO3OS is associated with the development of various cancers and has potential clinical applications.

Oxidative stress genes in patients with esophageal squamous cell carcinoma: construction of a novel prognostic signature and characterization of tumor microenvironment infiltration.

BACKGROUND: Oxidative stress plays an important role in the progression of various types of tumors. However, its role in esophageal squamous cell carcinoma (ESCC) has seldom been explored. This study aimed to discover prognostic markers associated with oxidative stress in ESCC to improve the prediction of prognosis and help in the selection of effective immunotherapy for patients. RESULTS: A consensus cluster was constructed using 14 prognostic differentially expressed oxidative stress-related genes (DEOSGs) that were remarkably related to the prognosis of patients with ESCC. The infiltration levels of neutrophils, plasma cells, and activated mast cells, along with immune score, stromal score, and estimated score, were higher in cluster 1 than in cluster 2. A prognostic signature based on 10 prognostic DEOSGs was devised that could evaluate the prognosis of patients with ESCC. Calculated risk score proved to be an independent clinical prognostic factor in the training, testing, and entire sets. P53 signaling pathway was highly enriched in the high-risk group. The calculated risk score was positively related to the infiltration levels of resting mast cells, memory B cells, and activated natural killer (NK) cells and negatively associated with the infiltration levels of M1 and M2 macrophages. The relationship between clinical characteristics and risk score has not been certified. The half-maximal inhibitory concentration (IC50) values for sorafenib and gefitinib were lower for patients in the low-risk group. CONCLUSION: Our prognostic signature based on 10 prognostic DEOSGs could predict the disease outcomes of patients with ESCC and had strong clinical value. Our study improves the understanding of oxidative stress in tumor immune microenvironment (TIME) and provides insights for developing improved and efficient immunotherapy strategies.

Thymic epithelial tumors: examining the GTF2I mutation and developing a novel prognostic signature with LncRNA pairs to predict tumor recurrence.

BACKGROUND: General transcription factor IIi (GTF2I) mutations are very common in thymic epithelial tumors (TETs) and are related to a more favorable prognosis in TET patients. However, limited research has been conducted on the role of GTF2I in the tumor immune microenvironment (TIME). Further, long non-coding RNAs (lncRNAs) have been associated with the survival of patients with TETs. Therefore, this study aimed to explore the relationship between GTF2I mutations and TIME and build a new potential signature for predicting tumor recurrence in the TETs. Research data was downloaded from The Cancer Genome Atlas database and the CIBERSORT algorithm was used to evaluate TIME differences between GTF2I mutant and wild-type TETs. Relevant differentially expressed lncRNAs based on differentially expressed immune-related genes were identified to establish lncRNA pairs. We constructed a signature using univariate and multivariate Cox regression analyses. RESULTS: GTF2I is the most commonly mutated gene in TETs, and is associated with an increased number of early-stage pathological types, as well as no history of myasthenia gravis or radiotherapy treatment. In the GTF2I wild-type group, immune score and immune cell infiltrations with M2 macrophages, activated mast cells, neutrophils, plasma, T helper follicular cells, and activated memory CD4 T cells were higher than the GTF2I mutant group. A risk model was built using five lncRNA pairs, and the 1-, 3-, and 5-year area under the curves were 0.782, 0.873, and 0.895, respectively. A higher risk score was related to more advanced histologic type. CONCLUSION: We can define the GTF2I mutant-type TET as an immune stable type and the GTF2I wild-type as an immune stressed type. A signature based on lncRNA pairs was also constructed to effectively predict tumor recurrence.

A novel signature based on immune-related gene pairs and clinical features to predict prognosis and treatment effect in "driver gene negative" lung adenocarcinoma.

OBJECTIVE: Examining the role of immune-related genes (IRGs) in "driver gene negative" lung adenocarcinoma (LUAD) may provide new ideas for the treatment and study for this LUAD subgroup. We aimed to find the hub immune-related gene pairs can stratify the risk of "driver-gene-negative" LUAD. MATERIALS AND METHODS: IRGs were identified according to ImmPort database based on RNA sequencing results of tumors and normal tissues from 46 patients with "driver gene negative" LUAD at The First Affiliated Hospital of Sun Yat-sen University and cyclically singly paired as immune-related gene pairs (IRGPs). Multivariate Cox analysis was used to construct an immune risk model and a prognostic nomogram combining was also been developed. Immune microenvironment landscape described by CIBERSORT and drug sensitivity calculated by pRRophetic algorithm were used to explore possible treatment improvements. RESULTS: A novel immune risk model with 5-IRGPs (CD1A|CXCL135, CD1A|S100A7L2, IFNA7|CMTM2, IFNA7|CSF3, CAMP|TFR2) can accurately distinguish patients in the high- and low-risk groups. Risk score act as an independent prognostic factor and is related to clinical stage. There are significant differences in tumor immune microenvironment and PD-1/PD-L1/CTLA-4 expression between groups. The low-risk patient may benefit more from the commonly used chemotherapy regimens such as gemcitabine and paclitaxel. CONCLUSION: This study constructed 5-IRGPs as a reliable prognostic tool and may represent genes pairs that are potential rationale for choice of treatment for "driver gene negative" LUAD.

A Novel Ras--Related Signature Improves Prognostic Capacity in Oesophageal Squamous Cell Carcinoma.

Oesophageal squamous cell carcinoma (ESCC) remains a clinically challenging disease with high morbidity rates and poor prognosis. ESCC is also the most common pathological type of oesophageal cancer (EC) in China. Ras-related genes are one of the most frequently mutated gene families in cancer and regulate tumour development and progression. Given this, we investigated the Ras-related gene expression profiles and their values in ESCC prognosis, using data from the Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) databases. We found that we could identify three distinct oesophageal cancer clusters based on their unique expression profile for 11 differentially expressed Ras-related genes with each of these demonstrating some prognostic value when, evaluated using univariate Cox analysis. We then used multivariate Cox analysis to identify relevant independent prognostic indicators and used these to build a new prognostic prediction model for oesophageal cancer patients using these three Ras-related genes. These evaluations produced an area under the curve (AUC) of 0.932. We found that our Ras-related signatures could also act as independent factors in ESCC prognosis and that patients with low Ras scores showed a higher overall expression levels of various immune checkpoint genes, including TNFSF4, TNFRSF8, TNFRSF9, NRP1, CD28, CD70, CD200, CD276, METTL16, METTL14, ZC3H13, YTHDF3, VIRMA, FTO, and RBM15, as well as a higher CSMD3, FLG, DNAH5, MUC4, PLCO, EYS, and ZNF804B mutation rates, and better sensitivity to drugs such as erlotinib, paclitaxel, and gefitinib. In conclusion, we were able to use the unique expression profiles of several Ras-related genes to produce a novel disease signature which might facilitate improved prognosis in ESCC, providing new insight into both diagnosis and treatment in these cancers.

Predicting response to immunotherapy plus chemotherapy in patients with esophageal squamous cell carcinoma using non-invasive Radiomic biomarkers.

OBJECTIVES: To develop and validate a radiomics model for evaluating treatment response to immune-checkpoint inhibitor plus chemotherapy (ICI + CT) in patients with advanced esophageal squamous cell carcinoma (ESCC). METHODS: A total of 64 patients with advance ESCC receiving first-line ICI + CT at two centers between January 2019 and June 2020 were enrolled in this study. Both 2D ROIs and 3D ROIs were segmented. ComBat correction was applied to minimize the potential bias on the results due to different scan protocols. A total of 788 features were extracted and radiomics models were built on corrected/uncorrected 2D and 3D features by using 5-fold cross-validation. The performance of the radiomics models was assessed by its discrimination, calibration and clinical usefulness with independent validation. RESULTS: Five features and support vector machine algorithm were selected to build the 2D uncorrected, 2D corrected, 3D uncorrected and 3D corrected radiomics models. The 2D radiomics models significantly outperformed the 3D radiomics models in both primary and validation cohorts. When ComBat correction was used, the performance of 2D models was better (p = 0.0059) in the training cohort, and significantly better (p < 0.0001) in the validation cohort. The 2D corrected radiomics model yielded the optimal performance and was used to build the nomogram. The calibration curve of the radiomics model demonstrated good agreement between prediction and observation and the decision curve analysis confirmed the clinical utility. CONCLUSIONS: The easy-to-use 2D corrected radiomics model could facilitate noninvasive preselection of ESCC patients who would benefit from ICI + CT.

Surgical treatment to multiple primary lung cancer patients: a systematic review and meta-analysis.

BACKGROUND: As there is no consensus on the optimal surgery strategy for multiple primary lung cancer (MPLC), we conducted this study to address this issue by comparing the prognosis of MPLC patients underwent different surgical strategies including sublobar resection and the standard resection through a systemic review and meta-analysis. METHODS: Relevant literature was obtained from three databases including PubMed, Embase and Web of Science. Inclusion and exclusion criteria were set for the screening of articles to be selected for further conduction of systemic review and meta-analysis. The HRs of OS of the sublobar group compared with standard resection group were extracted directly or calculated indirectly from included researches. RESULTS: Ten researches published from 2000 to 2017 were included in this study, with 468 and 445 MPLC cases for the standard resection group and sublobar resection group respectively. The result suggested that OS of MPLC patients underwent sublobar resection (segmentectomy or wedge resection for at least one lesion) was comparable with those underwent standard resection approach (lobectomy or pneumonectomy for all lesions), with HR 1.07, 95% CI 0.67-1.71, p = 0.784. Further analysis found no difference in subgroups of synchronous and metachronous (from second metachronous lesion), different population region and dominant sex type. CONCLUSIONS: This study may reveal that sublobar resection is acceptable for patients with MPLC at an early stage, because of the equivalent prognosis to the standard resection and better pulmonary function preservation. Further research is needed to validate these findings.

RIT1 suppresses esophageal squamous cell carcinoma growth and metastasis and predicts good prognosis.

Ras-like without CAAX1 (RIT1) protein is a member of Ras family, which plays critical roles in signaling pathways and cellular process regulation. However, the role of RIT1 in esophageal squamous cell carcinoma (ESCC) is unclear. In this study, we found that the expression of RIT1 is downregulated in ESCC compared to corresponding non-tumor tissues. The low-level expression of RIT1 was correlated with poorer prognosis. Then we showed that RIT1 inhibited proliferation, invasion, and migration of ESCC cells, and silencing RIT1 by shRNA promoted tumorigenicity and metastasis in nude mice. We further demonstrated that RIT1 inhibited the malignant behaviors of ESCC through inhibiting the PI3K/AKT and MAPK pathway and epithelial-mesenchymal transition in ESCC cells. Our study also revealed that RIT1 increased drug sensitivity to cisplatin (CDDP), and this function could be carried out through downregulating stemness of ESCC. In conclusion, our study indicates for the first time that RIT1 displays tumor-suppressing functions in ESCC, and these functions were carried out by inhibiting MAPK and PI3K/AKT signaling pathway, inhibiting EMT, and downregulating cancer stemness of ESCC cells.

Graphene oxide-hydroxyapatite nanocomposites effectively deliver HSV-TK suicide gene to inhibit human breast cancer growth.

Gene therapy with herpes simplex virus thymidine kinase gene (HSV-TK), which is also known as "suicide" gene therapy, is effective in various tumor models. The lack of a safe and efficient gene delivery system has become a major obstacle to "suicide" gene therapy. In this study, the cytotoxicity and transfection efficiency of graphene oxide-hydroxyapatite (GO-Hap) were analyzed by MTS and flow cytometry, respectively. A series of assays were performed to evaluate the effects of GO-HAp/p-HRE/ERE-Sur-TK combined with ganciclovir treatment on growth of human breast normal and cancer cells. The results showed that GO-HAp nanocomposites effectively transfected cells with minimum toxicity. GO-HAp/p-HRE/ERE-Sur-TK combined with ganciclovir treatment inhibited the proliferation and induced cell apoptosis in cancer cells, while the cytotoxic effects are tolerable in normal breast cells. We conclude that the GO-HAp nanocomposites have significant potential as a gene delivery vector for cancer therapy.

Effects of Glycogen Synthase Kinase-3ß Inhibitor TWS119 on Proliferation and Cytokine Production of TILs From Human Lung Cancer.

The canonical Wnt-ß-catenin signaling pathway arrests the differentiation of T cells and plays an important role in phenotypic maintenance of naive T cells and stem cell-like memory T cells in human peripheral blood, but its effect on tumor-infiltrating lymphocytes (TILs) from non-small cell lung cancer is little known. In this study, we showed that glycogen synthase kinase-3ß inhibitor TWS119 has different effects on CD4 and CD8 T cells in TILs. TWS119 preserved the expansion of naive T cell and CD8 stem cell-like memory T cells, and induced CD8 effector T-cell proliferation in TILs. To further determine whether TWS119 impaired the effector function of TILs, TILs were stimulated with polyclonal stimulation, IL-2 and IFN-γ production were detected. Our data showed that TWS119 does not affect the production of IFN-γ in TILs compared with the control group; whereas TWS119 inhibited IFN-γ secretion of T cells from healthy donor. IL-2 production in CD4 central memory T cells and CD4 effector memory T cells from TILs was significantly increased with the TWS119 treatment; TWS119 also promoted the secretion of IL-2 in all cell subsets of CD8 TILs. These findings reveal that TWS119 has a distinct effect on the proliferation and cytokine production of TILs, and provide new insights into the clinical application of TILs with TWS119 treatment for the adoptive immunotherapy.

Exogenous H2S promotes cancer progression by activating JAK2/STAT3 signaling pathway in esophageal EC109 cells.

Hydrogen sulfide (H2S) plays an important role in diverse physiological and pathophysiological processes in cancer cells both in vitro and in vivo. We have previously shown that exogenous H2S exerts its biological effects on hepatoma, glioma, and esophageal cancer cells through the activation of NF-κB, p38-MAPK/ERK1/2-COX-2, and HSP90 pathways. However, the role of H2S and the underlying mechanism in esophageal squamous cell carcinoma remain unclear. Here we investigated whether exogenous H2S contributes to the biological behavior of esophageal squamous cancer cell line EC109, through the activation of JAK2/STAT3 signaling pathway. EC109 cells were treated with NaHS (a donor of H2S) and AG490 (a specific inhibitor of JAK2/STAT3 signaling pathway). The expression levels of p-JAK2, p-STAT3, caspase-3/9/12, Bax, Bcl-2, MMP-2/9, and VEGFR were measured by western blot analysis. Cell viability was detected by CCK-8 and quantified by direct counting of cells under a microscope. Cell migration was analyzed by the scratch-wound assay, while the level of VEGF was measured by ELISA. Cells treated with NaHS for 24 h showed significant upregulation of p-JAK2, and p-STAT3 expression, as well as increased cell viability when compared to the control cells. The expression levels of caspase-3/9/12 and Bax decreased, while those of Bcl-2, MMP-2/9, VEGFR, and VEGF increased. NaHS induced the migration of EC109 cells. However, co-treatment with NaHS and AG490 significantly inhibited these effects. Thus, JAK2/STAT3 signaling pathway may contribute to H2S-induced cell proliferation, anti-apoptosis, migration, and angiogenesis in EC109 cells.

Preoperative serum fibrinogen is an independent prognostic factor in operable esophageal cancer.

In order to fully elucidate the association between serum fibrinogen and prognosis of esophageal cancer, we examined serum fibrinogen concentrations in 1512 patients who underwent esophagectomy by the Clauss method. The impact of fibrinogen on overall survival and disease-free survival was analyzed using the Kaplan-Meier method and Cox proportional hazard models. Hyperfibrinogenemia was significantly associated with older age, male gender, smoking, alcohol consumption, weight loss, advanced pathological T stage and lymph node metastasis. Patients with hyperfibrinogenemia exhibited poor OS (HR=1.20, 95%CI: 1.04-1.38, P=0.012) and DFS (HR=1.18, 95%CI: 1.03-1.35, P=0.019). Subgroup analysis further exhibited an significant association between hyperfibrinogenemia and poor OS (P<0.001), DFS (P<0.001) in esophageal squamous cell carcinoma (P<0.001) and early pathological stage (I-II) (P=0.001). Collectively, this study indicates that preoperative serum fibrinogen is an independent prognostic factor for survival in esophageal cancer.

Effect of mir-16 on proliferation and apoptosis in human A549 lung adenocarcinoma cells.

OBJECTIVE: To investigate the expression of mir-16 in lung adenocarcinoma cancer line and to observe the effect of mir-16 on the biological behaviors of human lung adenocarcinoma cancer A549 cell. Methods the expression of mir-16 in A549 cells was examined by quantitative real-time (qRT)-PCR. mir-16 minics was chemically synthesized and transfected into A549 cells by Lipofectamine 2000. The cell cycle and apoptosis changes were assayed by flow cytometry, the cell proliferation was measured by MTS assay. The wild-type and mutant wip1 3'-UTR luciferase reporter rectors were constructed. The relative activity of renila luciferase was detected to confirm the binding site of mir-16 on wip1 mRNA. Results, the expression of mir-16 is reduced in A549 cell compared with the normal bronchial epithelial cell. Transfection of mir-16 minics significantly suppressed the luciferase reporter containing wild type not mutant wip1 3'-UTR. Furthermore enforced expression of mir-16 lead to reduced A549 cell proliferation and promote apoptosis. Conclusion Therapeutic strategies to resume miRNA-16 expression may be benefit to patients with NSCLC in the feature.

The co-expression of ERß2 and IL-12Rß2 is better prognostic factor in non-small-cell lung cancer progression.

Estrogens and IL-12 play a pivotal role in the development and progression of non-small-cell lung cancer (NSCLC); at the same time, estrogen receptor ß2 and (interleukin-12 receptor ß2)IL-12Rß2 are their important receptors, respectively. With the functions of ERß2 and IL-12Rß2 explored further in NSCLC, some questions on the relation between ERß2 and IL-12Rß2 expression need to be solved. In this study, our aim is to elucidate relationship and roles of ERß2 and IL-12Rß2 in NSCLC. The expression of estrogen receptors ß2 and IL-12Rß2 was confirmed by Western blot and RT-PCR analysis in frozen tissues. The correlation between their expression levels and clinical characteristics was evaluated by Mann-Whitney and Kruskal-Wallis test. Using Kaplan-Meier plots and Cox proportional hazard models analyses, overall survival (OS) was evaluated. In contrast to benign pulmonary, ERß2 and IL-12Rß2 were over-expressed in NSCLC (p = 0.000). IHC results showed significant correlation between ERß2 and IL-12Rß2 (R = 0.382, p = 0.005). By analyzing the relation between ERß2, IL-12Rß2 mRNA expression levels and clinical characteristics, it was revealed that ERß2 and IL-12Rß2 were significant correlated with regional lymph node metastasis, T stage and clinical stage (p = 0.000/0.000; 0.001/0.000; 0.031/0.003 respectively), and both protein expression levels were lower with TNM stage being higher. In a Kaplan-Meier analysis, compared to both ERß2 and IL-12Rß2 or one low expression, high expression levels of ERß2 and IL-12Rß2 were identified in a group of patients with the longest overall survival (OS). Cox proportional hazard models revealed that ERß2 and IL-12Rß5 had longer OS. This is the first study to uncover that both ERß2 and IL-12Rß2 were over-expressed and further show that they were co-expressed in NSCLC. Moreover, we found that high expression levels of ERß2 and IL-12Rß2 may be positively correlated with OS and have prognostic values for the progression of NSCLC.

[Notch1 expression in esophageal squamous cell carcinoma and its relation with microvascular angiogenesis].

OBJECTIVE: To observe Notch1 expression in esophageal squamous cell carcinoma (ESCC) and investigate its relation with microvascular angiogenesis in the tumor. METHODS: Tissue slices of 40 cases ESCC (cancer group) and 8 cases normal esophagus tissues (normal group) were obtained to analyze the expression of Notch1 and vascular endothelial growth factor (VEGF) using immunohistochemistry and estimate the microvessel density (MVD) in the tumor. RESULTS: Notch1 expression was significantly lower in the cancer group than in the normal group (P<0.05). In the cancer group, Notch1 expression was higher in highly differentiated than in poorly differentiated tumors (P<0.05) regardless of tumor infiltration or lymph nodes metastasis (P>0.05). VEGF expression and MVD were significantly higher in cancer group than in normal group, and showed significant differences between tumors with different differentiation degrees, infiltration and lymph node metastasis (P<0.05). Correlation analysis showed that Notch1 expression was inversely correlated to VEGF expression. CONCLUSION: Notch1 may be an anti-oncogene in ESCC and affects cell differentiation in early stage of the malignancy. Abnormally low expression of Notch1 in ESCC may be one of the upstream factors to induce high expression of VEGF and increased MVD. The Notch1 pathway might play a key role in microvascular angiogenesis in ESCC.