Long Noncoding RNA PCAT6 Regulates Cell Proliferation and Migration in Human Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is the sixth most common cancer type in East Asian countries. Mounting evidences illustrated that long noncoding RNAs (lncRNAs) play important roles in a variety of human cancers, including ESCC. LncRNA PCAT6 has been identified as a tumor promoter in multiple cancers. However, the roles and underlying mechanism of PCAT6 in ESCC remain largely unclear. In the current study, we discovered that lncRNA PCAT6, which was aberrantly upregulated in ESCC tumor tissues, significantly promoted cell proliferation and migration in ESCC cell lines Eca-109 and Kyse-30 cells. Flow cytometry assays showed that PCAT6 knockdown promoted the apoptosis of ESCC cells. Mechanistically, RNA-seq and Gene Ontology analyses indicated that PCAT6 knockdown influenced the expression of genes that participated in cell proliferation and migration. Furthermore, real-time PCR and western blot assays validated that knockdown of PCAT6 could increase the levels of GDF15 and DUSP4 in Eca-109 and Kyse-30 cells. In brief, our findings reveal that lncRNA PCAT6 plays an oncogenic role in the progression of ESCC by inhibiting the expression of genes related to cell proliferation and migration.

[Assessment of the Accuracy of Modified Inflation-deflation Methods for Distinguishing the Intersegmental Border].

BACKGROUND: For early-stage lung cancer, segmentectomy can get the same oncological benefits as lobectomy. Accurate identification of the intersegmental border is the key to segmentectomy. This study used extended segmentectomy and extended subsegmentectomy to treat lung intersegmental and intersubsegmental ground-glass nodules (GGN) by utilizing modified inflation-deflation methods to distinguish the intersegmental and intersubsegmental borders. The accuracy of modified inflation-deflation methods and the effectiveness of extended resection to guarantee a safe surgical margin were evaluated. METHODS: A retrospective analysis of 83 cases of extended segmentectomy and extended subsegmentectomy was conducted. Preoperative three-dimensional computed tomography bronchography and angiography (3D-CTBA) revealed that nodules were involved in intersegmental or intersubsegmental veins. Based on preoperative three-dimensional reconstruction, the surgery was designed to extendedly remove the dominant lung segment or subsegment with nodules involved. When the dominant lung segment or subsegment could not be identified, the simpler lung segment or subsegment was selected for the resection. After the target vessel and bronchus were cut off during the operation, modified inflation-deflation method was used to determine the border, and a stapler was used to resect the adjacent lung segment or subsegment tissue by 2 cm-3 cm around the inflation-deflation boundary line. Then, the relationship between the inflation-deflation boundary line and the nodule and the width of the surgical margin were measured. Clinical data were collected during the perioperative period. RESULTS: 56 extended segmentectomies and 27 extended subsegmentectomies were performed. The average diameter of pulmonary nodules was (0.9±0.3) cm. There were 79 cases with clearly inflation-deflation boundary lines. The average time needed for the appearance of the lines was (13.6±6.5) min. In 55 cases, the nodules were involved with the inflation-deflation boundary lines. Meanwhile, the remaining 24 cases revealed an average minimum distance of (0.6±0.3) cm between nodules and the boundary lines. The average width of surgical margin was (2.1±0.3) cm in these 79 cases. No deaths or major complications appeared during 30 d after operation. CONCLUSIONS: The modified inflation-deflation method can effectively define the intersegmental and intersubsegmental borders, and guarantee the safe surgical margins of extended segmentectomy and extended subsegmentectomy to treat intersegmental and intersubsegmental small lung tumors.

Systematic analysis of genetic variants in cancer-testis genes identified two novel lung cancer susceptibility loci in Chinese population.

Cancer-testis (CT) genes played important roles in the progression of malignant tumors and were recognized as promising therapeutic targets. However, the roles of genetic variants in CT genes in lung cancer susceptibility have not been well depicted. This study aimed to evaluate the associations between genetic variants in CT genes and lung cancer risk in Chinese population. A total of 22,556 qualified SNPs from 268 lung cancer associated CT genes were initially evaluated based on our previous lung cancer GWAS (Genome-wide association studies) with 2,331 cases and 3,077 controls. As a result, 17 candidate SNPs were further genotyped in 1,056 cases and 1,053 controls using Sequenom platform. Two variants (rs6941653, OPRM1, T > C, screening: OR = 1.24, 95%CI: 1.12-1.38, P = 2.40×10-5; validation: OR = 1.18, 95%CI: 1.01-1.37, P = 0.039 and rs402969, NLRP8, C > T, screening: OR = 1.15, 95%CI: 1.04-1.26, P = 0.006; validation: OR = 1.16, 95%CI: 1.02-1.33, P = 0.028) were identified as novel lung cancer susceptibility variants. Stratification analysis indicated that the effect of rs6941653 was stronger in lung squamous cell carcinoma (OR = 1.36) than that in lung adenocarcinoma (OR = 1.15, I2 = 77%, P = 0.04). Finally, functional annotations, differential gene expression analysis, pathway and gene ontology analyses were performed to suggest the potential functions of our identified variants and genes. In conclusion, this study identified two novel lung cancer risk variants in Chinese population and provided deeper insight into the roles of CT genes in lung tumorigenesis.

Systematic cancer-testis gene expression analysis identified CDCA5 as a potential therapeutic target in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies with poor prognosis. Cancer-testis genes (CTGs) have been vigorously pursued as targets for cancer immunotherapy, but the expressive patterns and functional roles of CTGs remain unclear in ESCC. METHODS: A systematic screening strategy was adopted to screen CTGs in ESCC by integrating multiple public databases and RNA expression microarray data from 119 ESCC subjects. For the newly identified ESCC prognosis-associated CTGs, an independent cohort of 118 patients with ESCC was recruited to validate the relationship via immunohistochemistry. Furthermore, functional assays were performed to determine the underlying mechanisms. FINDINGS: 21 genes were recognized as CTGs, in particular, CDCA5 was aberrantly upregulated in ESCC tissues and significantly associated with poor prognosis (HR = 1.85, 95%CI: 1.14-3.01, P = .013). Immunohistochemical staining confirmed that positive CDCA5 expression was associated with advanced TNM staging and a shorter overall survival rate (45.59% vs 28.00% for CDCA5-/+ subjects, P = 1.86 × 10-3). H3K27 acetylation in CDCA5 promoter might lead to the activation of CDCA5 during ESCC tumorigenesis. Functionally, in vitro assay of gain- and loss-of-function of CDCA5 suggested that CDCA5 could promote ESCC cells proliferation, invasion, migration, apoptosis resistance and reduce chemosensitivity to cisplatin. Moreover, in vivo assay showed that silenced CDCA5 could inhibit tumor growth. Mechanistically, CDCA5 knockdown led to an arrest in G2/M phase and changes in the expression of factors that played fundamental roles in the cell cycle pathway. INTERPRETATION: CDCA5 contributed to ESCC progression and might serve as an attractive target for ESCC immunotherapy. FUND: This work was supported by the Natural Science Foundation of Jiangsu Province (No. BK20181083 and BK20181496), Jiangsu Top Expert Program in Six Professions (No. WSW-003 and WSW-007), Major Program of Science and Technology Foundation of Jiangsu Province (No. BE2016790 and BE2018746), Jiangsu Medical Young Talent Project (No. QNRC2016566), the Program of Jiangsu Medical Innovation Team (No. CXTDA2017006), Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX18_1487) and Jiangsu Province 333 Talents Project (No. BRA2017545).

Genome-wide copy number variation analysis identified ANO1 as a novel oncogene and prognostic biomarker in esophageal squamous cell cancer.

Copy number variations (CNVs) represent one of the most common genomic alterations. This study aimed to evaluate the roles of genes within highly aberrant genome regions in the prognosis of esophageal squamous cell cancer (ESCC). Exome sequencing data from 81 paired ESCC tissues were used to screen aberrant genomic regions. The associations between CNVs and gene expression were evaluated using gene expression data from the same individuals. Then, an RNA expression array profile from 119 ESCC samples was adopted for differential gene expression and prognostic analyses. Two independent ESCC cohorts with 315 subjects were further recruited to validate the prognostic value using immunohistochemistry tests. Finally, we explored the potential mechanism of our identified novel oncogene in ESCC. In total, 2003 genes with CNVs were observed, of which 76 genes showed recurrent CNVs in more than three samples. Among them, 32 genes were aberrantly expressed in ESCC tumor tissues and statistically correlated with CNVs. Strikingly, 4 (CTTN, SHANK2, INPPL1 and ANO1) of the 32 genes were significantly associated with the prognosis of ESCC patients. Patients with a positive expression of ANO1 had a poorer prognosis than ANO1 negative patients (overall survival rate: 42.91% versus 26.22% for ANO1-/+ samples, P < 0.001). Functionally, ANO1 promoted ESCC cell proliferation, migration and invasion by activating transforming growth factor-ß pathway. Knockdown of ANO1 significantly inhibited tumor progression in vitro and in vivo. In conclusion, ANO1 is a novel oncogene in ESCC and may serve as a prognostic biomarker for ESCC.