Integrative analysis of differential circular RNA and long non-coding RNA profiles and associated competing endogenous RNA networks in esophageal squamous cell carcinoma.

Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) play vital roles in the tumorigenesis of esophageal squamous cell carcinoma (ESCC). Nevertheless, the mechanism and regulatory network associated with this process remain largely unknown. In this study, we performed a comprehensive analysis of the expression of mRNAs, lncRNAs, and circRNAs by RNA-seq. A total of 3265 mRNAs, 1084 lncRNAs, and 38 circRNAs were found to be differentially expressed. Among these, 269 mRNAs were found to encode transcription factors (TFs). Functional enrichment analysis indicated that the dysregulated TFs are associated with the Hedgehog, Jak-STAT, TGF-beta, and MAPK signaling pathways. Furthermore, we constructed co-expression networks to screen the core lncRNAs and circRNAs involved in the regulation of transcription factors in these four pathways. Finally, we constructed a competing endogenous RNA (ceRNA) network of ESCC based on the abovementioned pathways. Our findings provide important insight into the role of lncRNAs and circRNAs in ESCC; the differentially expressed lncRNAs and circRNAs may represent potential targets for ESCC diagnosis and therapy.

Clinical characteristics and prognosis of ground-glass opacity nodules in young patients.

BACKGROUND: The detection rate of ground-glass opacity (GGO) in young patients has increased year by year with the increasingly widespread use of high-resolution computed tomography (HRCT) and the increased resolution of HRCT imaging. However, no scholars have reported the clinical characteristics and prognosis of GGO in young patients systematically. The purpose of this study is to investigate the clinical characteristics and prognosis presenting as GGO in young patients. METHODS: Clinical data of 127 young patients who were diagnosed as GGO and who underwent video-assisted thoracoscopic surgery (VATS) and had routine pathological examination were collected from January 2016 to January 2017. Nodules were classified according to benign and malignant: 26 benign nodules (Group A) and 115 malignant nodules (Group B). The pathological types, nodules size, surgical methods were analyzed, and the clinical characteristics and prognosis were evaluated. RESULTS: The results of pathological examination of 91 pure ground-glass opacities (pGGOs) revealed 16 adenocarcinoma in situs (AISs), 42 micro invasive adenocarcinomas (MIAs), 13 invasive adenocarcinomas (IAs), 8 atypical adenomatous hyperplasias (AAHs), 1 inflammatory granuloma, 2 pulmonary inflammatory pseudotumors (IPTs) and 9 other benign nodules. The results of pathological examination of 50 mixed ground-glass opacities (mGGOs) revealed 6 AISs, 29 MIAs, 9 IAs, 1 AAH, 2 inflammatory granulomas and 3 other benign nodules. All patients had no lymph nodes invasion. The rates of perioperative complications were 6.30%, compared to 7.63% for long-term complications. None of the patients with GGO experienced a recurrence and death [2-year recurrence-free survival (RFS), 100%; 2-year overall survival (OS), 100%]. CONCLUSIONS: The GGO in young patients that received VATS has a high proportion of malignant, its prognosis is satisfied.

Significance of Fas and FasL protein expression in cardiac carcinoma and local lymph node tissues.

OBJECTIVE: To investigate the relation of Fas and Fas ligand (FasL) protein expression with carcinogenesis and metastasis of cardiac carcinoma. METHODS: Immunohistochemistry was used to detect Fas and FasL protein expression in 64 cardiac carcinoma tissue samples and 20 normal gastric tissue samples. Relation between FasL and Fas expression, age and gender of gastric cancer patients, and pathological subtype and lymph node metastasis of gastric cancer was analyzed. RESULTS: The Fas expression level was significantly higher in normal gastric tissue samples than in cardiac carcinoma tissue samples (85.0% vs. 25.0%, P<0.001), while the FasL expression level was significantly lower in normal gastric tissue samples than in cardiac carcinoma tissue samples (30.0% vs. 81.3%, P<0.001). The Fas expression level was significantly higher in invasive lymph nodes than in non-invasive lymph nodes (82.9% vs. 56.5%, P<0.003) and in well-differentiated gastric carcinoma tissue samples than in poorly-differentiated cardiac carcinoma tissue samples (50.0% vs. 18.0%, P=0.015). The FasL expression level was significantly lower in well-differentiated cardiac carcinoma tissue samples than in poorly- differentiated cardiac carcinoma tissue samples (42.9% vs. 84.0%, P=0.021). The Fas and FasL expression levels (25.0% and 81.3%) were significantly different in cardiac carcinoma tissue samples (P<0.001), but had a non-linear correlation (P=0.575). CONCLUSION: Abnormal Fas and FasL expressions in cardiac carcinoma and lymph node tissues are involved in carcinogenesis and metastasis of gastric cancer.

Relationship of Fas, FasL, p53 and bcl-2 expression in human non-small cell lung carcinomas.

OBJECTIVE: Lack of surface Fas expression is a main route for apoptotic resistance which is considered an important mechanism of tumorigenesis and tumor progression. Fas and FasL expression in 110 non-small cell lung carcinomas (NSCLCs) were investigated to evaluate their roles in pulmonary carcinogenesis and to examine the clinicopathologic significance of Fas expression with its relationship with p53 and bcl-2 over- expression. METHODS: Immunohistochemical analysis using tissue microarray demonstrated that a large proportion of NSCLC patients (60%) showed lack of membranous Fas expression. The Fas-negative cases revealed the significantly lower survival rate than Fas-positive ones. Also, the loss of Fas receptor expression was found more frequently in advanced stage and higher nodal status. FasL protein was increased in most NSCLCs (89%) compared to normal lungs. RESULTS: p53 and bcl-2 overexpression showed no association with Fas expression. Conclusively, reduced membranous Fas expression as a mechanism of apoptotic resistance is considered to play an important part of the pulmonary carcinogenesis, which may predict poor survival and have a negative prognostic influence. CONCLUSION: Increased FasL expression is thought to be a basis for the immune evasion in NSCLCs. The rare bcl-2 overexpression suggests that this anti-apoptotic protein is unlikely to play a role in the apoptotic resistance of NSCLCs.

Adenovirus-mediated IL-24 confers radiosensitization to human lung adenocarcinoma in vitro and in vivo.

The current paper aims to study the effect of adenovirus-mediated IL-24 (Ad-IL-24) on human lung adenocarcinoma in vitro and in vivo and determine its possible mechanism of action. The growth-suppressing and apoptosis-inducing effects of Ad-IL-24, radiotherapy, and Ad-IL-24+ radiotherapy (hereinafter referred to as the joint group) on SPC-A1 lung carcinoma cells were assessed by using 3-(4,5-dimethyliazolyl-2)-2,5-diphnyltetrazolium bromide and flow cytometry. A human lung model was established with SPC-A1 cells in nude mice. Groups of mice were subjected to multi-point injections to their tumors. Gross tumor volumes were measured dynamically. The ratios of tumor suppression and radiosensitization effect were evaluated according to the method of probability sum Q values. The expressions of Bax, Bcl-2, Survivin, and Caspase-3 in tumor samples were detected by immunohistochemistry. The ratios of inhibition and apoptosis in the joint group were higher than those in the individual Ad-IL-24 and radiotherapy groups. In vitro, the joint group suppressed tumor growth conspicuously, showing a weight inhibition rate of about 64 %. The expressions of FasL, Bax and Caspase-3 were upregulated in the joint group, while the expressions of Cox,Bcl-2,VEGF,CD34 and Survivin were downregulated. The current study proves that Ad-IL-24 suppresses growth of SPC-A1 cells both in vitro and in vivo. Its functions appear to be related to cell apoptosis and antiangiogenesis.

Clinical outcomes of downregulation of E-cadherin gene expression in non-small cell lung cancer.

OBJECTIVE: To investigate the promoter methylation status of the E-cadherin gene in non-small cell lung cancer (NSCLC) and its association with clinical pathological parameters, and to explore the relationship between downregulation of E-cadherin gene expression and the methylation status of its promoter region. METHODS: Nested methylation-specific PCR was performed to examine CpG methylation within the 5' CpG island of the E-cadherin gene in lung cancer and para-cancerous tissue from 37 patients with primary non-small cell lung cancer. Quantitative real-time PCR was performed to measure the level of E-cadherin mRNA. RESULTS: Of thirty-seven cases, 12 (32.4%) samples showed aberrant CpG methylation in tumor tissues compared with the corresponding normal tissues. In addition, a reduction in E-cadherin mRNA levels was observed in 11 of the 12 (91.7%) tumor tissues carrying a methylated E-cadherin gene. However, only 10 (43.5%) cases displayed reduced mRNA levels in tumor tissues from the remaining 23 cases (excluding 2 samples from which mRNA was unavailable) without methylation events. Downregulation of E-cadherin gene expression significantly correlated with the promoter methylation status of this gene. CONCLUSION: These results provide strong evidence that the methylation status of E-cadherin gene contributes to a reduction in the expression of E-cadherin mRNA, and may play a role in the development and progression of NSCLC.

Anticancer effect and apoptosis induction by quercetin in the human lung cancer cell line A-549.

The aim of the present study was to investigate the anticancer effect of quercetin (QC) in the human lung cancer cell line A-549 and further study the mechanism of apoptosis induction by QC. Low differentiation potential A-549 human lung cancer cells were treated with QC at different doses and for different times, and the growth inhibitory rates were detected by MTT assay. Apoptosis induced by QC in A-549 cells was observed by Annexin V/PI double staining and flow cytometric assay. The relative tumor growth ratio of the treated/control tumors (T/C) (%) was chosen to represent the tumor growth inhibition of A-549 cell nude mouse xenografts by QC. Apoptosis of the nude mouse xenografts was observed by Annexin V/PI double staining and flow cytometric assay and DNA fragmentation assay. To further determine the molecular mechanism of apoptosis induced by QC, changes in the expression of bcl-2 and bax genes were detected by RT-PCR. Following incubation with QC, the cell growth of the low differentiation potential A-549 human lung cancer cells was dramatically inhibited in a dose-dependent manner. After the cells were exposed to QC for 24, 48 and 72 h, the IC50 value was 1.02 ± 0.05, 1.41 ± 0.20 and 1.14 ± 0.19 µmol/l, respectively. Apoptosis in the A-549 cells induced by QC was noted. The apoptotic subpopulation of A-549 cells was approximately 12.96 and 24.58%, respectively, when cells were incubated with 1.2 µmol/l QC for 48 and 72 h. T/C (%) of A-549 nude mouse xenografts was 44.3, when the nude mice were treated with QC (8 mg/kg). Meanwhile, apoptosis induced by QC was observed in the A-549 nude mouse xenografts. Increased expression of the bax gene and decreased expression of the bc1-2 gene were noted using RT-PCR. Our results provide further evidence of the growth inhibition of the A-549 human lung adenocarcinoma cancer cell line by QC. This effect is associated with the induction of apoptosis in A-549 cells and the molecular mechanism may be related to the reduction in expression of the apoptosis-regulating gene bcl-2, and increase in expression of the apoptosis-regulating gene bax. These results were also confirmed in vivo.

Anti-gastric cancer active immunity induced by FasL/B7-1 gene-modified tumor cells.

AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL(+)/B7-1(+)SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P<0.01). SGC-7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC-7901 cells (z = 2.06-44.30, P<0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1+/-2.4% vs 30.5+/-2.3%, P<0.05). CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.

Adenovirus-mediated FasL gene transfer into human gastric carcinoma.

AIM: To evaluate the possible value of FasL in gastric cancer gene therapy by investigating the effects of FasL expression on human gastric cancer cell line. METHODS: An adenoviral vector encoding the full-length human FasL cDNA was constructed and used to infect a human gastric cancer (SGC-7901) cell line. FasL expression was confirmed by X-gal staining, flow cytometric analysis and RT-PCR. The effect of FasL on cell proliferation was determined by clonogenic assay, cytotoxicity was detected by MTT assay, and cell viability was measured by trypan blue exclusion. The therapeutic efficiency of Ad-FasL in vivo was investigated with a xenograft tumor model in nude mice. RESULTS: SGC-7901 cells infected with Ad-FasL showed increased expression of FasL, resulting in significantly decreased cell growth and colony-forming activity when compared with control adenovirus-infected cells. The cytotoxicity of anti-Fas antibody (CH-11) in gastric cancer cells was stronger than that of ActD (91+/-8 vs 60+/-5, P<0.01), and the cytotoxicity of Ad-FasL was stronger than that of CH-11 (60+/-5 vs 50+/-2, P<0.05). In addition, G1-phase arrest (67.75+/-0.39 vs 58.03+/-2.16, P<0.05) and apoptosis were observed in Ad-FasL-infected SGC-7901 cells, and the growth of SGC-7901 xenografts in nude mice was retarded after intra-tumoral injection with Ad-FasL (54% vs 0%, P<0.0001). CONCLUSION: Infection of human gastric carcinoma cells with Ad-FasL induces apoptosis, indicating that this target gene might be of potential value in gene therapy for gastric cancer.