LINC00963 Promotes Cisplatin Resistance in Esophageal Squamous Cell Carcinoma by Interacting with miR-10a to Upregulate SKA1 Expression.

Long non-coding RNA (lncRNA) is associated with a large number of tumor cellular functions together with chemotherapy resistance in a variety of tumors. LINC00963 was identified to regulate the malignant progression of various cancers. However, whether LINC00963 affects drug resistence in esophageal squamous cell carcinoma (ESCC) and the relevant molecular mechanisms have never been reported. This study aims to investigate the effect of LINC00963 on cisplatin resistance in ESCC. After detecting the level of LINC00963 in human esophageal squamous epithelial cells (HET-1 A), ESCC cells (TE-1) and cisplatin resistant cells of ESCC (TE-1/DDP), TE-1/DDP cell line and nude mouse model that interfered with LINC00963 expression were established. Then, the interaction among LINC00963, miR-10a, and SKA1 was clarified by double luciferase and RNA immunoprecipitation (RIP) assays. Meanwhile, the biological behavior changes of TE-1/DDP cells with miR-10a overexpression or SKA1 silencing were observed by CCK-8, flow cytometry, scratch, Transwell, and colony formation tests. Finally, the biological function of the LINC00963/SKA1 axis was elucidated by rescue experiments. LINC00963 was upregulated in TE-1 and TE-1/DDP cell lines. LINC00963 knockdown inhibited SKA1 expression of both cells and impaired tumorigenicity. Moreover, LINC00963 has a target relationship with miR-10a, and SKA1 is a target gene of miR-10a. MiR-10a overexpression or SKA1 silencing decreased the biological activity of TE-1/DDP cells and the expression of SKA1. Furthermore, SKA1 overexpression reverses the promoting effect of LINC00963 on cisplatin resistance of ESCC. LINC00963 regulates TE-1/DDP cells bioactivity and mediates cisplatin resistance through interacting with miR-10a and upregulating SKA1 expression.

Knockdown of DEAD-box 51 inhibits tumor growth of esophageal squamous cell carcinoma via the PI3K/AKT pathway.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent malignancies that seriously threaten people's health worldwide. DEAD-box helicase 51 (DDX51) is a member of the DEAD-box (DDX) RNA helicase family, and drives or inhibits tumor progression in multiple cancer types. AIM: To determine whether DDX51 affects the biological behavior of ESCC. METHODS: The expression of DDX51 in ESCC tumor tissues and adjacent normal tissues was detected by Immunohistochemistry (IHC) analyses and quantitative PCR (qPCR). We knocked down DDX51 in ESCC cell lines by using a small interfering RNA (siRNA) transfection. The proliferation, apoptosis, and mobility of DDX51 siRNA-transfected cells were detected. The effect of DDX51 on the phosphoinositide 3-kinase (PI3K)/AKT pathway was investigated by western blot analysis. A mouse xenograft model was established to investigate the effects of DDX51 knockdown on ESCC tumor growth. RESULTS: DDX51 exhibited high expression in ESCC tissues compared with normal tissues and represented a poor prognosis in patients with ESCC. Knockdown of DDX51 induced inhibition of ESCC cell proliferation and promoted apoptosis. Moreover, DDX51 siRNA-expressing cells also exhibited lower migration and invasion rates. Investigations into the underlying mechanisms suggested that DDX51 knockdown induced inactivation of the PI3K/AKT pathway, including decreased phosphorylation levels of phosphate and tensin homolog, PI3K, AKT, and mammalian target of rapamycin. Rescue experiments demonstrated that the AKT activator insulin-like growth factor 1 could reverse the inhibitory effects of DDX51 on ESCC malignant development. Finally, we injected DDX51 siRNA-transfected TE-1 cells into an animal model, which resulted in slower tumor growth. CONCLUSION: Our study suggests for the first time that DDX51 promotes cancer cell proliferation by regulating the PI3K/AKT pathway; thus, DDX51 might be a therapeutic target for ESCC.

Prognostic value and functional bioinformatic analysis of spindle- and kinetochore-associated protein 1 in stage IIA esophageal squamous cell carcinoma.

BACKGROUND: As one of the most common malignant tumors of the digestive tract, esophageal squamous cell carcinoma (ESCC) is an advanced metastatic cancer with an extremely high mortality rate and the highest prevalence rate in China. Spindle- and kinetochore-associated protein 1 (SKA1), an essential member involved in chromosome separation during mitosis, has been indicated as a potential biomarker in the pathogenesis and development of various types of malignant tumors; however, the exact functions of SKA1 in ESCC are still unclear. PATIENTS AND METHODS: SKA1 expression was explored in stage IIA ESCC and corresponding healthy esophageal mucosa tissues through immunohistochemistry and reverse transcription-quantitative polymerase chain reaction and was further validated using The Cancer Genome Atlas (TCGA) database of the online tool UALCAN. Then, the clinicopathological correlations of SKA1 were analyzed based on the follow-up data. Furthermore, using the online tool LinkedOmics, the correlation test, gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of SKA1 were analyzed using high-throughput sequencing data of ESCC patients from TCGA dataset. RESULTS: The expression level of SKA1 was markedly upregulated in ESCC tissues. Upregulation of SKA1 significantly correlated with higher pathological T stage (P = 0.003) and poorer overall survival (P = 0.013). GO and pathway enrichment analyses of SKA1 in ESCC revealed that SKA1 was involved in a number of classical cell cycle-related pathways that contribute to special biological processes in tumorigenesis and development of ESCC. CONCLUSION: The results of this study demonstrate that SKA1 may act as a prognostic biomarker for stage IIA ESCC. Combined with the bioinformatic analysis, SKA1 could potentially serve as a therapeutic target for ESCC. CONCLUSION: The results coming from the present study demonstrated that SKA1 may act as a prognostic biomarker for stage IIA ESCC. Combined with the bioinformatic analysis, SKA1 could serve as a potential therapeutic target for ESCC.

SKA1 overexpression is associated with the prognosis of esophageal squamous cell carcinoma and regulates cell proliferation and migration.

Spindle and kinetochore­associated protein 1 (SKA1), a microtubule­binding subcomplex of the outer kinetochore, is essential for complete chromosomal separation. SKA1 has been suggested as a potential biomarker for various types of cancer. However, the exact role of SKA1 in esophageal squamous cell carcinoma (ESCC) remains unclear. The present study investigated whether SKA1 affects the biological behavior of ESCC. The expression of SKA1 in ESCC tissues was measured using immunohistochemistry and reverse transcription­quantitative polymerase chain reaction. In addition, a SKA1­silencing lentivirus was constructed, which was transfected into TE­1 cells to establish stable SKA1­knockdown TE­1 cells. Proliferation was analyzed using a Celigo image cytometer and a MTS assay. Cell cycle progression and apoptosis were analyzed by flow cytometry, while cell migration was assessed using a Transwell assay. SKA1 was significantly overexpressed in ESCC tissues, and SKA1 overexpression was significantly associated with differentiation, pathological N stage and pathological tumor­node­metastasis stage. SKA1 was determined to be an independent prognostic factor for ESCC. Furthermore, SKA1 was significantly overexpressed in ESCC cells, and SKA1­silencing inhibited cell proliferation and migration, arrested the cell cycle and promoted cell apoptosis. In summary, SKA1 may serve as a potential therapeutic target and prognostic biomarker for ESCC.

Functional cross-linked hemoglobin bis-tetramers: geometry and cooperativity.

Hemoglobin-based oxygen carriers have been sought as stable, sterile alternatives to red cells in transfusions. Problems in clinical trials using cross-linked tetramers have led to proposals that larger assemblies of tetramers may alleviate some of the problems. A study of such assemblies requires materials with defined structures and physical properties. Evaluation of cross-linked bis-tetramers with inflexible linear links between the tetramers revealed that these have very low cooperativity in oxygen binding and would thus be inefficient as oxygen carriers. New, more flexible reagents were designed to cross-link and connect tetramers in two modes: with angular connectors that permit torsional movement (1-3) and with linear connectors that resemble previously studied systems (4-6). The resulting cross-linked bis-tetramers were produced in high yield and were isolated and characterized. Digest mapping showed that modifications were specifically introduced as expected at amino groups in the 2,3-bisphosphoglycerate binding sites within beta subunits. Circular dichroism showed that the secondary structure of the globin chains is maintained while the microenvironment of the hemes is altered. The bis-tetramers derived from 1-3 have oxygen affinity (P(50) = 3.6-4.7) and cooperativity (n(50) = 2.2-2.7) that appear to be suitable for efficient oxygen delivery to hypoxic regions along with increased mass that is expected to minimize extravasation.

Clinicopathologic significance of HMGA2 expression's correlation with prognosis of esophageal squamous cell carcinoma after Ivor Lewis esophagectomy.

UNLABELLED: BACKGROUNDː The main reason for the commonly poor prognosis of esophageal squamous cell carcinoma (ESCC) after surgery is the high recurrence rate. For patients at high risk of recurrence, it may be of value to seek indicators of recurrence, which would be useful for further treatment. High-mobility group A2 (HMGA2) is a small non-histone chromosomal protein, highly expressed in many epithelial tissue malignant tumors and closely correlated with the occurrence, development and prognosis of tumor. Its aberrant expression in various cancers was detected, while its expression and significance in ESCC is still unclear. METHODSː We enrolled 127 patients with ESCC who had undergone Ivor-Lewis esophagectomy. The expression profile of HMGA2 was examined by immunohistochemistry. RESULTS: The result showed that the high expression of HMGA2 correlated with a higher T stage (P=0.007), lower differentiation degree (P=0.008), lymph node metastasis (P<0.01), recurrence status (P=0.005) and TNM stage (P=0.006). The Cox regression analysis showed that the TNM stage (P=0.006), differentiation degree (P=0.003) and high HMGA2 expression (P=0.048) were independent risk factors of survival. CONCLUSIONSː Our data indicated that HMGA2 expression level associates with key clinicopathological features and could be an effective biomarker to predict the prognosis of ESCC.

High expression of cyclooxygenase 2 is an indicator of prognosis for patients with esophageal squamous cell carcinoma after Ivor Lewis esophagectomy.

BACKGROUND: The poor prognosis of esophageal squamous cell carcinoma (ESCC) is attributed to a high recurrence rate after surgery. Cyclooxygenase 2 (COX2) is an important regulator of cell growth, differentiation, apoptosis, and transformation. COX2 overexpression is significantly associated with the tumorigenesis and progression of diverse cancers; however, its expression and significance in ESCC remains unclear. METHODS: We enrolled 118 patients with ESCC who had undergone Ivor-Lewis esophagectomy. The expression profile of COX2 was examined by immunohistochemistry. RESULTS: A high expression of COX2 correlated with a higher T staging (P = 0.014), lower differentiation degree (P = 0.002), lymph node metastasis (P = 0.009), recurrence status (P = 0.004), and tumor node metastasis (TNM) stage (P = 0.001). Cox regression analysis showed that TNM stage (P = 0.001), differentiation degree (P = 0.001), and high COX2 expression (P = 0.004) were independent risk factors of prognosis. CONCLUSION: Our data indicated that COX2 expression level is associated with key clinicopathological features and could be an effective biomarker to predict ESCC prognosis.

Efficient generation of dendritic arrays of cross-linked hemoglobin: symmetry and redundancy.

Chemically connected protein arrays have significant diverse applications including the production of red cell substitutes, bioconjugate drug delivery, and protein therapies. In order to make materials of defined structure, there is a need for efficient and accessible reagents. While chemical cross-linking with a multi-subunit protein can be achieved in high yield, connecting proteins to one another in a dendritic assembly along with concurrent cross-linking has met with limited success. This has now been overcome through the design and implementation of a readily prepared reagent with added reaction sites that compensate for competing hydrolysis. N,N',N''-Tris[bis(sodium methyl phosphate)isophthalyl]-1,3,5-benzenetricarboxamide (1), a hexakis(methyl phosphate) isophthalyl trimesoyl tris-amide, was designed and synthesized in high yield in three stages from a reactive trimesoyl core. This material has three pairs of coplanar cross-linking reaction sites in a symmetrical array. The presence of three sets of sites greatly increases the probability that at least two sets will produce cross-links within hemoglobin tetramers (in competition with hydrolysis) and thereby connect two cross-linked tetramers at the same time. Reaction of 1 with deoxyhemoglobin at pH 8.5 gives a material that contains two cross-linked hemoglobin tetramers connected to one another and to a constituent alphabeta dimer. Products were characterized by SDS-PAGE, MS, enzyme digestion and HPLC. The isolated dendritic-hemoglobin with 2.5 tetrameric components has the same oxygen affinity as native hemoglobin (P50 = 5.0 torr) and retains cooperativity (n50 = 2.0). Analysis of circular dichroism spectra indicates that the assembly retains proper folding of the globin chains while the hemes are in an altered environment.