Tripartite motif protein 11 (TRIM11), an oncogene for human lung cancer via the DUSP6-mediated ERK1/2 signaling pathway.

Evidence suggests that Tripartite Motif Containing 11 (TRIM11) has pro-tumor activity in human non-small cell lung cancer (NSCLC). However, the roles and underlying mechanisms of TRIM11 in NSCLC have not yet been fully elucidated. In this work, human lung cancer cell lines (A549, H446, and H1975) were transfected with siRNA or lentiviruses to knockdown or overexpress TRIM11 and dual-specificity phosphatase 6 (DUSP6). The cell tumor response was assessed by determining the rate of proliferation, apoptosis, the uptake of 2-[N-(7-nitrobenz-2-oxa-1, 3-diaxol-4-yl) amino]-2-deoxyglucose (2-NBDG), and the secretion of lactic acid (LD). Dominant-negative (dn)-MEK1 was used to block the ERK1/2 pathway. The mechanism was investigated by assessing the protein levels of pyruvate kinase isozymes M2 (PKM2) and DUSP6, as well as the activation of ERK1/2 pathway. Our data confirmed the anti-cancer effect of siTRIM11 in human lung cancer by demonstrating inhibition of cancer cell proliferation, induction of apoptosis, prevention of 2-NBDG uptake, suppression of LD production, and prevention of lung cancer cell (A549) tumorigenicity in nude mice. The underlying mechanism involved the up-regulation of DUSP6 and the inhibition of ERK1/2 activity. Overexpression of TRIM11 induced tumorigenesis of NSCLC in vitro, and the activation of ERK1/2 was significantly reversed by DUSP6 overexpression or additional dn-MEK1 treatment. Interestingly, we confirmed TRIM11 as a deubiquitinase that regulated DUSP6 accumulation, indicating that lung cancer progression is regulated via the DUSP6-ERK1/2 pathway. In conclusion, TRIM11 is an oncogene in NSCLC, likely through the DUSP6-mediated ERK1/2 signaling pathway.

What is the optimal radiation dose for non-operable esophageal cancer? Dissecting the evidence in a meta-analysis.

The standard radiation dose 50.4 Gy with concurrent chemotherapy for localized inoperable esophageal cancer as supported by INT-0123 trail is now being challenged since a radiation dose above 50 Gy has been successfully administered with an observable dose-response relationship and insignificant untoward effects. Therefore, to ascertain the treatment benefits of different radiation doses, we performed a meta-analysis with 18 relative publications. According to our findings, a dose between 50 and 70 Gy appears optimal and patients who received ≥ 60 Gy radiation had a significantly better prognosis (pooled HR = 0.78, P = 0.004) as compared with < 60 Gy, especially in Asian countries (pooled HR = 0.75, P = 0.003). However, contradictory results of treatment benefit for ≥ 60 Gy were observed in two studies from Western countries, and the pooled treatment benefit of ≥ 60 Gy radiation was inconclusive (pooled HR = 0.86, P = 0.64). There was a marginal benefit in locoregional control in those treated with high dose (> 50.4/51 Gy) radiation when compared with those treated with low dose (≤ 50.4/51 Gy) radiation (pooled OR = 0.71, P = 0.06). Patients that received ≥ 60 Gy radiation had better locoregional control (OR = 0.29, P = 0.001), and for distant metastasis control, neither the > 50.4 Gy nor the ≥ 60 Gy treated group had any treatment benefit as compared to the groups that received ≤ 50.4 Gy and < 60 Gy group respectively. Taken together, a dose range of 50 to 70 Gy radiation with CCRT is recommended for non-operable EC patients. A dose of ≥ 60 Gy appears to be better in improving overall survival and locoregional control, especially in Asian countries, while the benefit of ≥ 60 Gy radiation in Western countries still remains controversial.

[The negative enrichment by immunomagnetic beads for tumor cells from malignant pleural effusions].

OBJECTIVE: To establish a method (negative enrichment by immunomagnetic beads) for detection of tumor cells in pleural effusions and to evaluate the sensitivity and specificity of the method for clinical application. METHODS: Five, 10, 20, 50 and 100 A549 (lung adenocarcinoma) cells were labeled with DAPI and added into 20 ml pleural effusions [containing (1 - 10)×10(6)cells] from heart failure patients, followed by immunomagnetic negative enrichment method. Recovered cancer cells were enumerated using a fluorescent microscope. Tumor cells were enriched from pleural effusion samples by means of density gradient centrifugation and negative enrichment by immunomagnetic beads method, followed by identification with cytology analysis (Wright's Giemsa's staining), immunofluorescence staining (IF) and fluorescence in situ hybridization (FISH) using centromere DNA probes of chromosome 7 and 8. Cytology, IF and FISH evaluations were performed in 53 pleural effusion samples, including 36 cases of malignant disease (25 male and 11 female patients aging 40 to 78 years, mean age (63 ± 9) and 17 cases of benign disease (8 male and 9 female patients aging 25 to 81 years, mean age (53 ± 18). RESULTS: After DAPI staining and mixing with pleural effusions from heart failure patients, the cell recovery rates of A549 cells evaluated under fluorescence microscope were 75%, 78%, 82%, 85%, 88%, and the average recovery rate was 81.6%. Using negative enrichment method and density gradient centrifugation combined with cytology analysis, the positive rates of tumor cells in 36 malignant pleural effusion samples were 81% (29/36) and 61% (22/36), respectively (χ(2) = 4.00, P = 0.039). Using negative enrichment method combined with IF, the positive rate of CK18(+), DAPI(+), CD(45)(-) cells was 100%. Moreover, using negative enrichment method combined with FISH analysis, the positive rate of tumor cells was 86% (31/36), much higher than that using density gradient centrifugation combined with cytology analysis (χ(2) = 5.818, P = 0.012). In 17 cases of benign pleural effusions, using negative enrichment method combined with IF, the positive rate was 100%. But other methods didn't find cancer cells from benign pleural effusions. CONCLUSIONS: It was applicable to enrich tumor cells from pleural effusions using negative enrichment method by immunomagnetic beads. This method combined with cytology analysis or FISH significantly enhanced the sensitivity and specificity of tumor cell detection in pleural effusions. But it was difficult to distinguish cancer cells from mesothelial cells using immunofluorescence staining with CK18, DAPI and CD(45) label. More specific markers were needed to recognize tumor cells from pleural effusions.