Degradation of Mcl-1 through GSK-3ß Activation Regulates Apoptosis Induced by Bufalin in Non-Small Cell Lung Cancer H1975 Cells.

BACKGROUND/AIMS: Mcl-1, an anti-apoptotic Bcl-2 family member, is often overexpressed in non-small cell lung cancer (NSCLC). Bufalin has been reported to induce apoptosis in various tumor cells. However, there is no report showing that bufalin could downregulate Mcl-1 expression in NSCLC. METHODS: Cell proliferation was analyzed by cell counting kit-8 (CCK-8) assay in H1975 cells. Cell apoptosis was detected by flow cytometry. Mcl-1 mRNA was detected by RT-PCR. The expression of apoptosis-associated proteins in H1975 cells was detected by western blotting. The levels of Mcl-1 ubiquitination and NOXA were analyzed by Immunoprecipitation assay. RESULTS: Cell growth was inhibited by bufalin in a time and dose-dependent manner. Bufalin induced apoptosis in NSCLC cells by activating caspase cascades and downregulating Mcl-1 expression. However, overexpression of Mcl-1 diminished bufalin-induced apoptosis. Furthermore, bufalin did not reduce Mcl-1 mRNA expression in H1975 cells, but strongly promoted Mcl-1 protein degradation. Proteasome inhibitor MG132 markedly prevented the degradation of Mcl-1 and blocked bufalin-induced Mcl-1 reduction. Bufalin did not significantly affect NOXA protein levels, but downregulated the expression of p-GSK-3ß. GSK-3 inhibitor and GSK-3ß siRNA resulted in increased levels of Mcl-1 and reversed the bufalin-induced Mcl-1 degradation. CONCLUSION: Bufalin induced cell apoptosis in H1975 cells may be through downregulation of Mcl-1. Proteasomal degradation of Mcl-1 via GSK-3ß activation was involved in bufalin-induced apoptosis.

Nomogram for predicting the preoperative lymph node metastasis in resectable pancreatic cancer.

BACKGROUND: Lymph node metastasis (LNM) is a critical prognostic factor in resectable pancreatic cancer (PC) patients, determining treatment strategies. This study aimed to develop a clinical model to adequately and accurately predict the risk of LNM in PC patients. METHODS: 13,200 resectable PC patients were enrolled from the SEER (Surveillance, Epidemiology, and End Results) database, and randomly divided into a training group and an internal validation group at a ratio of 7:3. An independent group (n = 62) obtained from The First Affiliated Hospital of Xinxiang Medical University was enrolled as the external validation group. The univariate and multivariate logistic regression analyses were used to screen independent risk factors for LNM. The minimum Akaike's information criterion (AIC) was performed to select the optimal model parameters and construct a nomogram for assessing the risk of LNM. The performance of the nomogram was assessed by the receiver operating characteristics (ROC) curve, calibration plot, and decision curve analysis (DCA). In addition, an online web calculator was designed to assess the risk of LNM. RESULT: A total of six risk predictors (including age at diagnosis, race, primary site, grade, histology, and T-stage) were identified and included in the nomogram. The areas under the curves (AUCs) [95% confidential interval (CI)] were 0.711 (95%CI: 0.700-0.722), 0.700 (95%CI: 0.683-0.717), and 0.845 (95%CI: 0.749-0.942) in the training, internal validation and external validation groups, respectively. The calibration curves showed satisfied consistency between nomogram-predicted LNM and actual observed LNM. The concordance indexes (C-indexes) in the training, internal, and external validation sets were 0.689, 0.686, and 0.752, respectively. The DCA curves of the nomogram demonstrated good clinical utility. CONCLUSION: We constructed a nomogram model for predicting LNM in pancreatic cancer patients, which may help oncologists and surgeons to choose more individualized clinical treatment strategies and make better clinical decisions.

[Analysis of prognostic factors in 68 patients with cancer of unknown primary site].

OBJECTIVE: The aim of this study was to analyze the clinical characteristics and prognostic factors in patients with cancer of unknown primary site (CUP). METHODS: The clinical and follow-up data of 68 CUP patients (46 adenocarcinoma patients, 22 squamous cell carcinoma patients), were retrospectively analyzed. Univariate and multivariate analysis were conducted to determine the correlation of survival with clinical features, tumor markers, blood test, liver function and so on. RESULTS: The median survival time of the 68 CUP patients was 123 days. The results from univariate Cox regression analysis showed that the prognostic factors were related to a performance status, presence or absence of liver metastases, the number of metastatic sites, carcinoembryonic antigen (CEA), lactate dehydrogenase (LDH), hypoalbuminemia, hypohemoglobinemia and lymphocyte count. Multivariate Cox regression analysis of the clinical factors identified that a performance status (PS) ≥ 2, liver metastasis, elevated serum carcinoembryonic antigen (CEA) and lactate dehydrogenase (LDH) levels, hypoalbuminemia (< 35 g/L) and lymphopenia (≤ 0.7 × 10(9)/L) were significant independent unfavorable predictive factors. Based on the number of the unfavorable predictive factors, we divided all the patients into three subgroups: subgroup involving 0-1 unfavorable factor, subgroup involving 2 - 3 unfavorable factors and subgroup involving 4 - 6 unfavorable factors. The median survival time was 390 days, 138 days and 77 days, respectively, in the 3 subgroups. Compared with the other two groups, the survival of the subgroup involving 0 - 1 unfavorable factor was significantly longer (P < 0.05), the survival between the subgroup involving 2 - 3 unfavorable factors and subgroup involving 4 - 6 unfavorable factors was not significantly different (P > 0.05). CONCLUSIONS: A performance status ≥ 2, liver metastasis, elevated serum carcinoembryonic antigen and lactate dehydrogenase levels, hypoalbuminemia and lymphopenia are independent unfavorable prognostic factors in patients with cancer of unknown primary site. The patients who had more than 2 unfavorable prognostic factors have a worse prognosis.

Effects of silencing the ATP-binding cassette protein E1 gene by electroporation on the proliferation and migration of EC109 human esophageal cancer cells.

In the present study, the gene expression of ATP-binding cassette protein E1 (ABCE1) in the EC109 human esophageal cancer cell line was silenced using electroporation to examine the effect if the ABCE1 gene on the growth migration and cell cycle of cancer cells. The small interference (si)RNA sequence of ABCE1 was designed and synthesized to transfect the EC109 cells by electroporation. The mRNA and protein expression levels of ABCE1 were then detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The analysis of the cell cycle and apoptosis was performed using flow cytometry. The effect of silencing the ABCE1 gene on the proliferation, migration and invasive ability of the EC109 human esophageal cancer cells were assessed using a Cell counting kit-8 (CCK-8) and with proliferation, wound-healing and cell invasion assays. The mRNA and protein expression levels of ABCE1 were significantly lower in the experimental group compared with the control group (P<0.05). The apoptotic rate of the experimental group was markedly higher than the control group and blank group (P<0.01). The CCK-8 proliferation assay revealed that, compared with the control and blank groups, the proliferation of the EC109 cells in the experimental group was significantly inhibited (P<0.05). The wound healing assay revealed that the migration capacity of the cells in the experimental group was significantly decreased (P<0.05). The Transwell chamber assay demonstrated that the invasive ability of the EC109 cells in the experimental group was significantly decreased (P<0.01). These results revealed that ABCE1 is closely associated with cell proliferation, invasion and migration in esophageal cancer and silencing the ABCE1 gene by electroporation can significantly reduce the proliferation, invasion and migration capacity of EC109 cells in vitro.

Radiosensitivity enhancement by arsenic trioxide in conjunction with hyperthermia in the EC-1 esophageal carcinoma cell line.

OBJECTIVE: To explore the effect on radiosensitivity of arsenic trioxide (As203) in conjunction with hyperthermia on the esophageal carcinoma EC-1 cell line. METHOD: Inhibition of EC-1 cell proliferation at different concentrations of As203 was assessed using the methyl thiazolyl blue colorimetric method (MTT method), with calculation of IC50 value and choice of 20% of the IC50 as the experimental drug concentration. Blank control, As203, hyperthermia, radiotherapy group, As203 + hyperthermia, As203 + radiotherapy, hyperthermia + radiotherapy and As203 + hyperthermia + radiotherapy groups were established, and the cell survival fraction (SF) was calculated from flat panel colony forming analysis, and fitted by the 'multitarget click mathematical model'. Flow cytometry (FCM) was used to detect changes in cell apoptosis and the cell cycle. RESULTS: As203 exerted inhibitory effects on proliferation of esophageal carcinoma EC-1 cells, with an IC50 of 18.7 µmol/L. After joint therapy of As203 + hyperthermia + radiotherapy, the results of FCM showed that cells could be arrested in the G2/M phase, and as the ratio of cells in G0/G1 and S phases decreased, cell death became more pronounced. CONCLUSION: As203 and hyperthermia exert radiosensitivity effects on esophageal carcinoma EC-1 cells, with synergy in combination. Mechanistically, As203 and hyperthermia mainly influence the cell cycle distribution of EC-1 esophageal carcinoma cells, decreasing the repair of sublethal damage and inducing apoptosis, thereby enhancing the killing effects of radioactive rays.