lncRNA-encoded pep-AP attenuates the pentose phosphate pathway and sensitizes colorectal cancer cells to Oxaliplatin.

Oxaliplatin (L-OHP) is a standard treatment for colorectal cancer (CRC), but chemoresistance is a considerable challenge. L-OHP shows dose-dependent toxicity, and potential approaches that sensitize cancer cells to L-OHP could reduce the dosage. With the development of translatomics, it was found that some lncRNAs encode short peptides. Here, we use ribosome footprint profiling combined with lncRNA-Seq to screen 12 lncRNAs with coding potential, of which lnc-AP encodes the short peptide pep-AP, for their role in L-OHP resistance. Co-IP and LC-MS/MS data show that the TALDO1 protein interacts with pep-AP and that pep-AP suppresses the expression of TALDO1. The pep-AP/TALDO1 pathway attenuates the pentose phosphate pathway (PPP), reducing NADPH/NADP+ and glutathione (GSH) levels and causing ROS accumulation and apoptosis, which sensitizes CRC cells to L-OHP in vitro and in vivo. pep-AP thus might become a potential anticancer peptide for future treatments of L-OHP-resistant CRC.

nhKcr: a new bioinformatics tool for predicting crotonylation sites on human nonhistone proteins based on deep learning.

Lysine crotonylation (Kcr) is a newly discovered type of protein post-translational modification and has been reported to be involved in various pathophysiological processes. High-resolution mass spectrometry is the primary approach for identification of Kcr sites. However, experimental approaches for identifying Kcr sites are often time-consuming and expensive when compared with computational approaches. To date, several predictors for Kcr site prediction have been developed, most of which are capable of predicting crotonylation sites on either histones alone or mixed histone and nonhistone proteins together. These methods exhibit high diversity in their algorithms, encoding schemes, feature selection techniques and performance assessment strategies. However, none of them were designed for predicting Kcr sites on nonhistone proteins. Therefore, it is desirable to develop an effective predictor for identifying Kcr sites from the large amount of nonhistone sequence data. For this purpose, we first provide a comprehensive review on six methods for predicting crotonylation sites. Second, we develop a novel deep learning-based computational framework termed as CNNrgb for Kcr site prediction on nonhistone proteins by integrating different types of features. We benchmark its performance against multiple commonly used machine learning classifiers (including random forest, logitboost, naïve Bayes and logistic regression) by performing both 10-fold cross-validation and independent test. The results show that the proposed CNNrgb framework achieves the best performance with high computational efficiency on large datasets. Moreover, to facilitate users' efforts to investigate Kcr sites on human nonhistone proteins, we implement an online server called nhKcr and compare it with other existing tools to illustrate the utility and robustness of our method. The nhKcr web server and all the datasets utilized in this study are freely accessible at http://nhKcr.erc.monash.edu/.

Exosomal miR-208b related with oxaliplatin resistance promotes Treg expansion in colorectal cancer.

Oxaliplatin resistance is a challenge in the treatment of colorectal cancer (CRC) patients. Regulatory T cells (Tregs) are well known for their immunosuppressive roles, and targeting Tregs is an effective way to improve chemosensitivity. Exosome-delivered microRNA (miRNA) might be used as a potential biomarker for predicting chemosensitivity. However, the relationship between Tregs and exosomal miRNAs remains largely unknown. TaqMan low-density array was performed to screen the differentially expressed serum miRNAs from pooled serum of patients who had FOLFOX treatment. Differential expression was validated using qRT-PCR in individual samples. Exosomes were isolated by sequential differential centrifugation, and they were verified by transmission electron microscopy. The RNA and protein levels were determined by quantitative real-time PCR and western blotting. A mouse xenograft model was adopted to evaluate the correlation between exosome-derived miR-208b and Tregs in vivo. We demonstrated that circulating miR-208b is a non-invasive marker for predicting FOLFOX sensitivity in CRC. miR-208b in colon cancer was secreted by tumor cells in the pattern of exosomes, and oxaliplatin-resistant cells showed the most obvious phenomenon of miR-208b increase. Colon cancer cell-secreted miR-208b was sufficiently delivered into recipient T cells to promote Treg expansion by targeting programmed cell death factor 4 (PDCD4). Furthermore, in vivo studies indicated that Treg expansion mediated by cancer cell-secreted miR-208b resulted in tumor growth and oxaliplatin resistance. Our results demonstrate that tumor-secreted miR-208b promotes Treg expansion by targeting PDCD4, and it may be related to a decrease of oxaliplatin-based chemosensitivity in CRC. These findings highlight a potential role of exosomal miR-208b as a predictive biomarker for oxaliplatin-based therapy response, and they provide a novel target for immunotherapy.

Imbalance of TGF-ß1/BMP-7 pathways induced by M2-polarized macrophages promotes hepatocellular carcinoma aggressiveness.

The transforming growth factor-beta (TGF-ß) signaling pathway is the predominant cytokine signaling pathway in the development and progression of hepatocellular carcinoma (HCC). Bone morphogenetic protein (BMP), another member of the TGF-ß superfamily, has been frequently found to participate in crosstalk with the TGF-ß pathway. However, the complex interaction between the TGF-ß and BMP pathways has not been fully elucidated in HCC. We found that the imbalance of TGF-ß1/BMP-7 pathways was associated with aggressive pathological features and poor clinical outcomes in HCC. The induction of the imbalance of TGF-ß1/BMP-7 pathways in HCC cells could significantly promote HCC cell invasion and stemness by increasing inhibitor of differentiation 1 (ID1) expression. We also found that the microRNA (miR)-17-92 cluster, originating from the extracellular vesicles (EVs) of M2-polarized tumor-associated macrophages (M2-TAMs), stimulated the imbalance of TGF-ß1/BMP-7 pathways in HCC cells by inducing TGF-ß type II receptor (TGFBR2) post-transcriptional silencing and inhibiting activin A receptor type 1 (ACVR1) post-translational ubiquitylation by targeting Smad ubiquitylation regulatory factor 1 (Smurf1). In vivo, short hairpin (sh)-MIR17HG and ACVR1 inhibitors profoundly attenuated HCC cell growth and metastasis by rectifying the imbalance of TGF-ß1/BMP-7 pathways. Therefore, we proposed that the imbalance of TGF-ß1/BMP-7 pathways is a feasible prognostic biomarker and recovering the imbalance of TGF-ß1/BMP-7 pathways might be a potential therapeutic strategy for HCC.

Gastric cancer derived exosomes mediate the delivery of circRNA to promote angiogenesis by targeting miR-29a/VEGF axis in endothelial cells.

Accumulating evidence has been found that circular RNA (circRNA) plays a critical role in the initiation and development of various diseases by modulating gene expression in the cytoplasm. However, the role of circ_0044366 (termed circ29) in gastric cancer (GC) has yet to be elusive. We detected that exosomal circ29 was confirmed to be highly expressed in GC and can significantly impair the proliferation, migration, tube formation of HUVEC by exosomal communication. Interestingly, this effect could be blocked by the effect of miR-29a. In brief, we confirmed that circ29, as a sponge of miR-29a, plays a responsible role in the occurrence and development of GC by regulating the VEGF pathway. Therefore, it may be used as a potential target for the treatment of GC.

CAF secreted miR-522 suppresses ferroptosis and promotes acquired chemo-resistance in gastric cancer.

BACKGROUND: Ferroptosis is a novel mode of non-apoptotic cell death induced by build-up of toxic lipid peroxides (lipid-ROS) in an iron dependent manner. Cancer-associated fibroblasts (CAFs) support tumor progression and drug resistance by secreting various bioactive substances, including exosomes. Yet, the role of CAFs in regulating lipid metabolism as well as ferroptosis of cancer cells is still unexplored and remains enigmatic. METHODS: Ferroptosis-related genes in gastric cancer (GC) were screened by using mass spectrum; exosomes were isolated by ultra-centrifugation and CAF secreted miRNAs were determined by RT-qPCR. Erastin was used to induce ferroptosis, and ferroptosis levels were evaluated by measuring lipid-ROS, cell viability and mitochondrial membrane potential. RESULTS: Here, we provide clinical evidence to show that arachidonate lipoxygenase 15 (ALOX15) is closely related with lipid-ROS production in gastric cancer, and that exosome-miR-522 serves as a potential inhibitor of ALOX15. By using primary stromal cells and cancer cells, we prove that exosome-miR-522 is mainly derived from CAFs in tumor microenvironment. Moreover, heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) was found to mediate miR-522 packing into exosomes, and ubiquitin-specific protease 7 (USP7) stabilizes hnRNPA1 through de-ubiquitination. Importantly, cisplatin and paclitaxel promote miR-522 secretion from CAFs by activating USP7/hnRNPA1 axis, leading to ALOX15 suppression and decreased lipid-ROS accumulation in cancer cells, and ultimately result in decreased chemo-sensitivity. CONCLUSIONS: The present study demonstrates that CAFs secrete exosomal miR-522 to inhibit ferroptosis in cancer cells by targeting ALOX15 and blocking lipid-ROS accumulation. The intercellular pathway, comprising USP7, hnRNPA1, exo-miR-522 and ALOX15, reveals new mechanism of acquired chemo-resistance in GC.

Identification of HGF as a novel target of miR-15a/16/195 in gastric cancer.

Background Gastric malignancy is the third most frequently encountered cancer globally and have been documented to confer extremely poor prognosis, given their limited treatment options. The up-regulation of hepatocyte growth factor (HGF) has been found in various tumor tissues, including GC tissue, and has been linked with tumor development. Nevertheless, the pathways leading to HGF upregulation have yet to be fully explored. Methods Immunohistochemistry (IHC) assay was used to detect HGF expression in human gastric tumor tissues, while western blotting allowed quantification of protein levels. Bioinformatics tools were used to predict potential miRNA that may target HGF mRNA. Relative levels of miR-15a/16/195 as well as the target mRNA levels were analyzed with qRT-PCR. Direct targeting between miRNA and mRNA was then validated by luciferase assay. Finally, a mouse xenograft tumor model was selected to demonstrate the in vivo effects of miR-15a/16/195. Results HGF protein expressions were markedly raised, while miR-15a/16/195 levels were dramatically down-regulated in tumor tissues of GC. miR-15a/16/195 were shown to directly bind with the 3'-UTR of HGF mRNA. This study demonstrated that HGF can be repressed by overexpressed miR-15a/16/195, which resulted in the suppression of GC cell proliferation and migration. Furthermore, in the xenograft mouse model, miR-15a/16/195 were also found to have a tumor growth suppression effect. Conclusions miR-15a/16/195 suppresses tumorigenesis by targeting HGF and may have a potential therapeutic application in the clinical treatment of GC.

Exosomal circRNA derived from gastric tumor promotes white adipose browning by targeting the miR-133/PRDM16 pathway.

Cancer-related cachexia is a metabolic syndrome characterized by a wasting disorder of adipose and skeletal muscle and is accompanied by body weight loss and systemic inflammation. The treatment options for cancer cachexia are limited, and the molecular mechanism remains poorly understood. Circular RNAs (circRNAs) are a novel family of endogenous noncoding RNAs that have been proposed to regulate gene expression in mammals. Exosomes are small vesicles derived from cells, and recent studies have shown that circRNAs are stable in exosomes. However, little is known about the biological role of circRNAs in exosomes. In our study, we showed that circRNAs in plasma exosomes have specific expression features in gastric cancer (GC), and ciRS-133 is linked with the browning of white adipose tissue (WAT) in GC patients. Exosomes derived from GC cells deliver ciRS-133 into preadipocytes, promoting the differentiation of preadipocytes into brown-like cells by activating PRDM16 and suppressing miR-133. Moreover, knockdown of ciRS-133 reduced cancer cachexia in tumor-implanted mice, decreasing oxygen consumption and heat production. Thus, exosome-delivered circRNAs are involved in WAT browning and play a key role in cancer-associated cachexia.

MiR-181a, a new regulator of TGF-ß signaling, can promote cell migration and proliferation in gastric cancer.

Transforming growth factor-beta (TGF-ß) signaling pathway plays pivotal roles in various types of cancer. TGF-ß receptor 2 (TGFßR2) contains a kinase domain that phosphorylates and activates the downstream of the TGF-ß signaling pathway. Our previous microarray analysis revealed marked changes in miR-181a expression in gastric cancers, and the bioinformatics analysis suggested that miR-181a negatively regulated TGFßR2. In order to verify the effect of miR-181a on TGFßR2 and clarify the influence of miR-181a on the migration and proliferation of gastric cancer, studies in gastric cancer cell lines and xenograft mouse models were carried out. We found that a reduced expression of TGFßR2 and an increased expression miR-181a in gastric cancer tissues compared to adjacent noncancerous tissues. A luciferase reporter assay confirmed that TGFßR2 was a target of miR-181a. In addition, we found that miR-181a mimics, which increased the level of miR-181a, downregulated the expression of TGFßR2 in the gastric cancer cell line SGC-7901. Moreover, both the overexpression of miR-181a and the downregulation of TGFßR2 promoted the migration and proliferation of SGC-7901 cells. Conversely, SGC-7901 cell migration and proliferation were inhibited by the downregulation of miR-181a and the overexpression of TGFßR2. Furthermore, the increased expression of miR-181a and the decreased expression of TGFßR2 also enhanced the tumor growth in mice bearing gastric cancer. Our results herein indicated that miR-181a promoted the migration and proliferation of gastric cancer cells by downregulating TGFßR2 at the posttranscriptional level. The present study suggests that miR-181a is a novel negative regulator of TGFßR2 in the TGF-ß signaling pathway and thus represents a potential new therapeutic target for gastric cancer.

Exosomes Serve as Nanoparticles to Deliver Anti-miR-214 to Reverse Chemoresistance to Cisplatin in Gastric Cancer.

Chemoresistance is one of the causes of adverse effects in gastric cancer, including a poor response to cisplatin (DDP). Exosomes loaded with microRNA (miRNA), mRNA, and other non-coding RNAs could regulate drug resistance. Exo-anti-214 was extracted and verified. A Cell Counting Kit-8 (CCK-8) cell viability assay, flow cytometry, and transwell and immunofluorescence assays were performed to determine whether exo-anti-214 could sensitize cells to DDP in vitro. A combination of intravenously injected exo-anti-214 and intraperitoneal DDP was utilized in vivo. Additionally, potential targets of miR-214 were screened by mass spectrometry (MS) and confirmed via western blotting (WB). The levels of miR-214 in the human immortalized gastric epithelial cell line ges-1 and the human gastric adenocarcinoma cell lines SGC7901 and SGC7901/DDP gradually increased. Exo-anti-214 could fuse with cells and regulate potential targets, reducing cell viability, suppressing migration, and promoting apoptosis in vitro. Caudally injected exo-anti-214 was applied to reverse chemoresistance and repress tumor growth in vivo due to the downregulation of miR-214 and overexpression of possible target proteins in tumors. Exo-anti-214 could reverse the resistance to DDP in gastric cancer, which might serve as a potential alternative for the treatment of cisplatin-refractory gastric cancer in the future.

Glutathione reductase mediates drug resistance in glioblastoma cells by regulating redox homeostasis.

Glutathione (GSH) and GSH-related enzymes constitute the most important defense system that protects cells from free radical, radiotherapy, and chemotherapy attacks. In this study, we aim to explore the potential role and regulatory mechanism of the GSH redox cycle in drug resistance in glioblastoma multiforme (GBM) cells. We found that temozolomide (TMZ)-resistant glioma cells displayed lower levels of endogenous reactive oxygen species and higher levels of total antioxidant capacity and GSH than sensitive cells. Moreover, the expression of glutathione reductase (GSR), the key enzyme of the GSH redox cycle, was higher in TMZ-resistant cells than in sensitive cells. Furthermore, silencing GSR in drug-resistant cells improved the sensitivity of cells to TMZ or cisplatin. Conversely, the over-expression of GSR in sensitive cells resulted in resistance to chemotherapy. In addition, the GSR enzyme partially prevented the oxidative stress caused by pro-oxidant L-buthionine -sulfoximine. The modulation of redox state by GSH or L-buthionine -sulfoximine regulated GSR-mediated drug resistance, suggesting that the action of GSR in drug resistance is associated with the modulation of redox homeostasis. Intriguingly, a trend toward shorter progress-free survival was observed among GBM patients with high GSR expression. These results indicated that GSR is involved in mediating drug resistance and is a potential target for improving GBM treatment.

MicroRNA-155 promotes gastric cancer growth and invasion by negatively regulating transforming growth factor-ß receptor 2.

Gastric cancer (GC) is one of the most common malignancies worldwide and has high morbidity and mortality rates. It is essential to elucidate the molecular events of GC proliferation and invasion, which will provide new therapeutic targets for GC. The inactivation of transforming growth factor-ß receptor 2 (TGFßR2) correlates with cancer cell growth and metastasis, but the mechanisms underlying the downregulation of TGFßR2 expression remain unknown. MicroRNAs (miRNAs) act as post-transcriptional regulators and play a key role in the development of cancers. Bioinformatics analysis and luciferase reporter assays have shown that miR-155 directly binds to the 3'-UTR of TGFßR2 mRNA. In this study, we found that the TGFßR2 protein levels, but not mRNA levels, were downregulated in GC tissues, and the levels of miR-155 were significantly increased in GC tissues. We deduced that miR-155 was inversely correlated with TGFßR2 in GC cells. In vitro studies showed that overexpression of miR-155 in SGC7901 inhibited the expression of TGFßR2 and then promoted GC cell proliferation and migration, whereas miR-155 inhibitor showed opposite effects. In addition, the tumor-suppressing function of TGFßR2 was verified by using siRNA and TGFßR2 overexpressing plasmids. The results showed that miR-155 promotes cell growth and migration by negatively regulating TGFßR2. Thus, miR-155-regulated TGFßR2 as a potential therapeutic target in GC.

Exosomes serve as nanoparticles to suppress tumor growth and angiogenesis in gastric cancer by delivering hepatocyte growth factor siRNA.

Exosomes derived from cells have been found to mediate signal transduction between cells and to act as efficient carriers to deliver drugs and small RNA. Hepatocyte growth factor (HGF) is known to promote the growth of both cancer cells and vascular cells, and the HGF-cMET pathway is a potential clinical target. Here, we characterized the inhibitory effect of HGF siRNA on tumor growth and angiogenesis in gastric cancer. In addition, we showed that HGF siRNA packed in exosomes can be transported into cancer cells, where it dramatically downregulates HGF expression. A cell co-culture model was used to show that exosomes loaded with HGF siRNA suppress proliferation and migration of both cancer cells and vascular cells. Moreover, exosomes were able to transfer HGF siRNA in vivo, decreasing the growth rates of tumors and blood vessels. The results of our study demonstrate that exosomes have potential for use in targeted cancer therapy by delivering siRNA.

miR-26a/b Inhibit Tumor Growth and Angiogenesis by Targeting the HGF-VEGF Axis in Gastric Carcinoma.

BACKGROUND/AIMS: Abnormal expression of HGF is found in various cancers and correlates with tumor proliferation, metastasis and angiogenesis. However, the regulatory mechanism of the HGF-VEGF axis remains unclear. METHODS: The expression characteristic of HGF in human gastric cancer tissues was shown by an immunohistochemistry assay, and the expression levels of target protein were detected by Western blot. The relative levels of miR-26a/b and target mRNA were examined by qRT-PCR. We used bioinformatics tools to search for miRNAs that can potentially target HGF. A luciferase assay was used to confirm direct targeting. Furthermore, the functions of miR-26a/b and HGF were evaluated by cell proliferation and migration assays in vitro and by the mouse xenograft tumor model in vivo. RESULTS: We found that the HGF protein was clearly increased while miR-26a/b were dramatically down-regulated in gastric cancer. miR-26a/b directly bind to the 3'-UTR of HGF mRNA at specific targeting sites. We demonstrated that the repression of the HGF-VEGF pathway by miR-26a/b overexpression suppressed gastric cancer cell proliferation and migration. Furthermore, miR-26a/b also showed an anti-tumor effect in the xenograft mouse model by suppressing tumor growth and angiogenesis. CONCLUSIONS: miR-26a/b could suppress tumor tumorigenesis and angiogenesis by targeting the HGF-VEGF axis and could serve as a potential treatment modality for targeted therapy in the clinical treatment of gastric cancer.

miR-221 and miR-222 synergistically regulate hepatocyte growth factor activator inhibitor type 1 to promote cell proliferation and migration in gastric cancer.

Gastric cancer is a common malignancy with limited treatment options and poor prognosis. Introduction of novel pathways of gastric cancer will provide candidates for target therapy. Hepatocyte growth factor activator inhibitor type 1 is an integral-membrane proteinase inhibitor. Hepatocyte growth factor activator inhibitor type 1 abnormality is found in various cancers and correlates with tumor progression and metastasis. However, the mechanisms underlying the dysregulation of hepatocyte growth factor activator inhibitor type 1 expression in gastric cancer remain unclear. Although microRNAs have been reported to be involved in the development of cancer, the roles of miR-221 and miR-222 in gastric cancer have not been reported yet. In this study, we showed that hepatocyte growth factor activator inhibitor type 1 protein was downregulated, while miR-221 and miR-222 were significantly increased in gastric cancer tissues. Bioinformatic predictions and luciferase assay verified that the 3'-untranslated region of the HAI-1 gene is a direct target site for miR-221 and miR-222. Overexpression of miR-221 and miR-222 in MGC-803 cells leads to the inhibition of hepatocyte growth factor activator inhibitor type 1 protein expression, thus promoting cell proliferation and migration; whereas knockdown of miR-221 and miR-222 showed opposite effects. Moreover, we found that the expression level of hepatocyte growth factor activator protein was increased when hepatocyte growth factor activator inhibitor type 1 was knocked down in MGC-803 cells. Thus, gastric cancer is probably an autocrine tumor, and the antitumor mechanism of hepatocyte growth factor activator inhibitor type 1 in vitro might be mediated by regulating the expression of hepatocyte growth factor activator protein. Therefore, our data illustrated a novel pathway comprising miR-221and miR-222 and hepatocyte growth factor activator inhibitor type 1 in gastric cancer, which is a potential target for future clinical use.

MiR-520b/e Regulates Proliferation and Migration by Simultaneously Targeting EGFR in Gastric Cancer.

BACKGROUND: MicroRNAs (miRNAs) have been demonstrated to play a crucial role in tumorigenesis. Previous studies have shown that miR-520b/e acts as a tumor suppressor in several tumors. Other studies indicated that epidermal growth factor receptor (EGFR) is highly expressed in many tumors, and involved in the development of tumors, such as cell proliferation, migration, angiogenesis and apoptosis. However, the correlation of miRNAs and EGFR in gastric cancer (GC) has not been adequately investigated. Our aim was to explore the relationship. METHODS: The expression levels of EGFR and miR-520b/e were examined by RT-PCR and Western blot. We also investigated the relationship between EGFR and miR-520b/e in GC cell lines by relevant experiments. RESULTS: In this study, we found that miR-520b/e inhibits the protein expression of EGFR by directly binding with the 3'-untranslated region (3'-UTR). And it was shown that the down-regulation of miR-520b/e promotes cell proliferation and migration by negative regulation of the EGFR pathway, while over-expression of miR-520b/e inhibits these properties. In addition, the biological function of EGFR in GC cell lines was validated by silencing and over-expression assays respectively. CONCLUSIONS: Taken together, our results demonstrate that miR-520b/e acts as a tumor suppressor by regulating EGFR in GC, and provide a novel marker and insight for the potential therapeutic target of GC.

Direct targeting of HGF by miR-16 regulates proliferation and migration in gastric cancer.

MicroRNAs (miRNAs) have been reported to be involved in each stage of tumor development in various types of cancers. We have previously showed that miR-16 is downregulated in cancer and acts as a tumor suppressor. Other studies indicated that hepatocyte growth factor (HGF)/c-Met is implicated in proliferation, migration, and other pathophysiological processes. However, little is known about the relationship between miR-16 and HGF/c-Met in gastric cancer (GC). In the present study, we used bioinformatics tools and related experiments to search for miRNAs targeting HGF. Here, we found that miR-16 suppressed HGF protein expression by directly targeting 3'-untranslated region (UTR) of HGF mRNA. Subsequently, it was illustrated the downregulation of miR-16 promotes, while overexpressed of miR-16 significantly inhibits cell proliferation and migration by negatively regulating HGF/c-Met pathway. Moreover, the biological role of HGF in GC cells was determined by using HGF siRNA and HGF-overexpressing plasmid, respectively. To conclude, our results provide a potential target by using miR-16 for the future clinical treatment of GC.

Prognostic nomogram for previously untreated patients with esophageal squamous cell carcinoma after esophagectomy followed by adjuvant chemotherapy.

OBJECTIVE: The aim of the study was to establish an effective prognostic nomogram for esophageal squamous cell carcinoma after radical esophagectomy followed by adjuvant chemotherapy in those previously untreated patients. METHODS: The clinicopathological data from 328 patients who underwent radical esophagectomy followed by adjuvant chemotherapy or not at the Tianjin Medical University Cancer Institute and Hospital between 2006 and 2010 were retrospectively studied. Nomograms which predicted survival of esophageal squamous cell carcinoma were established based on the Cox proportional hazards regression model. To determine its predictive accuracy and discriminatory capacity, the concordance index and calibration curve were calculated after bootstrapping in the internal validation. An external validation of 76 patients in 2011 was prospectively studied at the same institution. To verify the performance of the nomogram, the comparison between the nomogram and Tumor-Node-Metastasis staging system was conducted. RESULTS: The 5-year overall survival was 43.1% in the primary cohort. Based on multivariate analyses, five independent prognostic variables including gender, tumor length, T stage, N stage and chemotherapy cycles were selected to build the nomograms to predict disease-free survival and overall survival. The concordance index of the nomogram to predict overall survival was 0.71 (95% confidence interval, 0.63-0.79), which was superior to the predictive power of Tumor-Node-Metastasis staging system (0.64) in the primary cohort. Meanwhile, the calibration curve showed good accuracy between predictive and actual overall survival. In the validation cohort, the concordance index (0.77) and calibration plot displayed favorable performances. The other nomogram to predict disease-free survival also performed well. CONCLUSIONS: The prognostic nomogram provided individualized risk estimate of survival in patients after esophagectomy followed by adjuvant chemotherapy.