MicroRNA-200b reverses chemoresistance of docetaxel-resistant human lung adenocarcinoma cells by targeting E2F3.

BACKGROUND: MicroRNAs (miRNAs) have been identified as important posttranscriptional regulators involved in various biological and pathological processes of cells, but their association with tumor chemoresistance has not been fully understood. METHODS: We detected miRNA-200b (miR-200b) expression in different lung adenocarcinoma cell lines and then focused on its roles in regulation of docetaxel chemoresistance. We also identified E2F3 as a novel target of miR-200b. RESULTS: Based on miRNA microarray data, miR-200b was identified as the most down-regulated miRNA in docetaxel-resistant SPC-A1/DTX cells compared with parental SPC-A1 cells. Ectopic miR-200b expression reversed docetaxel chemoresistance of lung adenocarcinoma cells through cell proliferation inhibition, apoptosis enhancement, and G(2) /M cell cycle arrest. In a nude mouse xenograft model, up-regulation of miR-200b significantly enhanced response of SPC-A1/DTX cells to docetaxel. Luciferase reporters containing the 3' untranslated region sequence of E2F3 messenger RNA were used to demonstrate that miR-200b could directly target E2F3. Small interfering RNA-mediated E2F3 knockdown revealed similar effects as that of ectopic miR-200b expression. Decreased miR-200b expression was also detected in tumor tissues sampled from lung adenocarcinoma patients treated with docetaxel-based chemotherapy and was proved to be correlated with high expression of E2F3, decreased sensitivity to docetaxel, and poor prognosis. CONCLUSIONS: Our results suggest that down-regulation of miR-200b could lead to E2F3 overexpression and in turn contribute to chemoresistance of lung adenocarcinoma cells to docetaxel.

Nimotuzumab increases chemosensitivity of human lung adenocarcinoma cell lines to docetaxel.

Overexpression of epidermal growth factor receptor (EGFR) is common in non-small-cell lung cancer (NSCLC) and has been recently shown to contribute to cancer chemoresistance. It has been reported that the EGFR antibodies such as cetuximab in combination with chemotherapy could lead to an absolute benefit of overall survival (OS) compared with chemotherapy alone. In this study, we investigated the effects of nimotuzumab (h-R3), a humanized anti-EGFR antibody, in combination with docetaxel (DTX), on DTX-resistant human lung adenocarcinoma cell line SPC-A1 (SPC-A1/DTX) both in vitro and in vivo. Immunohistochemistry and FCM assays demonstrated that SPC-A1/DTX cells had a relatively higher rate of EGFR overexpression than SPC-A1 cells. Accordingly, SPC-A1/DTX cells were approximately 13.7 times resistant to DTX than SPC-A1 cells. The combined therapy of h-R3 and DTX showed strong synergistic suppressive effect on cell proliferation of SPC-A1/DTX cells in vitro. The synergistic antitumor effect was also observed in SPC-A1/DTX xenograft-bearing nude mice. Further study showed that h-R3 could lead to a significant cell arrest at G1 phase of cell cycle in both SPC-A1DTX and SPC-A1 cells. A dramatic increase of apoptosis rate was detected in h-R3-treated SPC-A1/DTX but not SPC-A1 cells. Moreover, when combined with DTX, h-R3 brought higher apoptosis rate in SPC-A1/DTX cells rather than in SPC-A1 cells. In conclusion, our results suggested that h-R3 could significantly enhance chemosensitivity of human lung adenocarcinoma cells to DTX, at least partially by induction of G1 phase arrest and cell apoptosis.

Bone metastasis of esophageal carcinoma diagnosed as a first primary tumor: a population-based study.

Background: This study aimed to explore predictors of bone metastasis (BM) of esophageal carcinoma (EC) and factors affecting the prognosis of EC with BM (ECBM). Methods: We retrospectively studied the data of EC patients from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2016. Logistic regression analysis was used to analyze the risk factors of BM. Cox regression and Fine and Gray's competing risk regression were performed to identify prognostic factors associated with all-cause and cancer-specific death, respectively. The Kaplan-Meier method was used to assess survival. Results: After exclusion, 8,916 patients were eligible, of whom 462 (5.2%) had ECBM. Independent risk factors of BM were age <65 years, male sex, stage T1, advanced N stage, and non-bone organ metastases. For EC, the median survival time (MST) was 17 months, and the 3- and 5-year survival rates were 31.6% and 23.3%, respectively; meanwhile, for BM, the MST was 5 months, and the 3- and 5-year survival rates were 2% and 1%, respectively. Adenocarcinoma, stage T2, the absence of non-bone organ metastases, and combined radiotherapy and chemotherapy were associated with a reduced risk of all-cause death in ECBM patients. Stage T2, the absence of non-bone organ metastases, and combined radiotherapy and chemotherapy were associated with a decreased risk of cancer-specific death in ECBM patients. Conclusions: Although rare, BM severely impairs the prognosis of EC. BM predictors and factors influencing the prognosis of ECBM may help distinguish high-risk patients with BM and assess survival in ECBM patients.

Development and Validation of a Clinical Prognostic Nomogram for Esophageal Adenocarcinoma Patients.

BACKGROUND: Clinical staging is essential for clinical decisions but remains imprecise. We purposed to construct a novel survival prediction model for improving clinical staging system (cTNM) for patients with esophageal adenocarcioma (EAC). METHODS: A total of 4180 patients diagnosed with EAC were extracted from the Surveillance, Epidemiology, and End Results (SEER) database and included as the training cohort. Significant prognostic variables were identified for nomogram model development using multivariable Cox regression. The model was validated internally by bootstrap resampling, and then subjected to external validation with a separate cohort of 886 patients from 2 institutions in China. The prognostic performance was measured by concordance index (C-index), Akaike information criterion (AIC) and calibration plots. Different risk groups were stratified by the nomogram scores. RESULTS: A total of six variables were determined related with survival and entered into the nomogram construction. The calibration curves showed satisfied agreement between nomogram-predicted survival and actual observed survival for 1-, 3-, and 5-year overall survival. By calculating the AIC and C-index values, our nomogram presented superior discriminative and risk-stratifying ability than current TNM staging system. Significant distinctions in survival curves were observed between different risk subgroups stratified by nomogram scores. CONCLUSION: The established and validated nomogram presented better risk-stratifying ability than current clinical staging system, and could provide a convenient and reliable tool for individual survival prediction and treatment strategy making.

[Targeted therapies for hormone-refractory prostate cancer].

Prostate cancer is one of the most common type of cancer among men after middle age. Androgen withdrawal can delay its progression in the initial stage, but it finally becomes independent of androgens in almost all the cases. The combination of docetaxel with prednisone is currently a standard first-line treatment for patients with hormone-refractory prostate cancer (HRPC), but hitherto there is no established second-line therapy. In view of the molecular pathogenesis of HRPC, this article presents an overview on several promising drugs that target specific pathways, involving angiogenesis, cell signaling, apoptosis and proliferation, and immune modulation, either as single agents or in combination with cytotoxic chemotherapy.

(18)F-DG PET/CT in detection of recurrence and metastasis of colorectal cancer.

AIM: To evaluate the value of (18)F-DG PET/CT in detecting recurrence and/or metastasis of colorectal cancer (CRC). METHODS: Combined visual analysis with semiquantitative analysis, the (18)F-DG PET/CT whole-body imaging results and the corresponding clinical data of 68 postoperative CRC patients including 48 male and 20 female with average age of 58.1 were analyzed retrospectively. RESULTS: Recurrence and/or metastasis were confirmed in 56 patients in the clinical follow-up after the PET/CT imaging. The sensitivity of PET/CT diagnosis of CRC recurrence and/or metastasis was 94.6%, and the specificity was 83.3%. The positive predictive value (PPV) was 96.4% and the negative predictive value (NPV) was 76.9%. PET/CT imaging detected one or more occult malignant lesions in 8 cases where abdominal/pelvic CT and/or ultrasonography showed negative findings, and also detected more lesions than CT or ultrasonography did in 30.4% (17/56) cases. Recurrence and/or metastasis was detected in 91.7% (22/24) cases with elevated serum CEA levels by (18)F-DG PET/CT imaging. CONCLUSION: (18)F-DG PET/CT could detect the recurrence and/or metastasis of CRC with high sensitivity and specificity.

[Advances in researches on hormonal refractory prostate cancer].

In China, the incidence of prostate cancer has been increasing in recent years. Hormonal therapy has been the mainstay of the therapeutic options for metastatic diseases for many years. But many metastatic tumors progress at a median of two to five years and become hormonal refractory prostate cancer (HRPC). This article summarizes in the advances of diagnostic criteria, molecular biological features, prediction markers, new therapeutic agents and further researches to be undertaken concerning HRPC.

[Association between the survival time and high-expression of EGFR and HER-2 in breast cancer].

OBJECTIVE: To investigate the relationship between the survival time and the high-expression of epidermal growth factor receptor (EGFR) and human epidermal receptor 2 (HER2) in breast cancer patients, and assess the feasibility of using the two markers either alone or in combination for predicting the prognosis of the patients. METHODS: Breast cancer samples were obtained from 185 patients and measured for the expressions of EGFR and HER-2 by way of immunohistochemistry, and 120 patients (64.9%) were followed up and their survival time recorded. Sixty-five patients (35.1%) failed to be followed for various reasons. RESULTS: Of the 120 patients followed up, death occurred in 28 (15%). Positive HER2 expression was detected in 57.8% and EGFR expression in 40.5% of the all the samples examined. The over-expression of either HER2 or EGFR was in inverse correlation with the survival time (P<0.05 and P<0.01, respectively), and the over-expression of both related to the survival time in similar manner (P<0.05 and P<0.01). CONCLUSION: The high expression of HER2 or/and EGFR suggests a short survival time and an unfavorable prognosis.

Clinical significance of angiopoietin-like protein 4 expression in tissue and serum of esophageal squamous cell carcinoma patients.

Angiopoietin-like protein 4 (ANGPTL4) has been reported to promote tumor growth, metastasis, and angiogenesis under certain conditions. The aim of this study was to examine ANGPTL4 expression in tumor and serum tissues from esophageal squamous cell carcinoma (ESCC) patients. A total of 78 ESCC patients treated with radical resection were enrolled in this study. Immunohistochemistry was used to detect ANGPTL4 expression in ESCC tissues. Serum ANGPTL4 levels were determined via enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristics curve was constructed to describe diagnostic specificity and sensitivity. There were 52 cases (69.2 %) showing a higher level of ANGPTL4 expression in tumor tissues than that in normal tissues, and the rate of ANGPTL4 protein high/moderate expression in ESCC and normal tissues was 55.1 % (43/78) and 6.4 % (5/78), respectively, with a significant difference (P < 0.001). Moreover, the high/moderate of ANGPTL4 protein was significantly associated with lymph metastasis, clinical stage, and adverse 2-year progression-free survival. In addition, serum ANGPTL4 level in ESCC patients was much higher than that in patients with benign esophageal disease (P < 0.001), and area under the curve was 0.94 (95 % CI 0.886390-0.978173, P < 0.001). But serum ANGPTL4 level was significantly decreased at post-operative 7-10 days (P = 0.004). ANGPTL4 upregulation may play an important role in ESCC development, and serum ANGPTL4 level may be a potential tumor marker for ESCC diagnosis and prognosis.

Epigenetic downregulation of RUNX3 by DNA methylation induces docetaxel chemoresistance in human lung adenocarcinoma cells by activation of the AKT pathway.

The RUNX3 gene has been shown to function as a tumor suppressor gene implicated in various cancers, but its association with tumor chemoresistance has not been fully understood. Here, we investigated the effect of epigenetic downregulation of RUNX3 in docetaxel resistance of human lung adenocarcinoma and its possible molecular mechanisms. RUNX3 was found to be downregulated by hypermethylation in docetaxel-resistant lung adenocarcinoma cells. Its overexpression could resensitize cells to docetaxel both in vitro and in vivo by growth inhibition, enhancement of apoptosis and G1 phase arrest. Conversely, knockdown of RUNX3 could lead to the decreased sensitivity of parental human lung adenocarcinoma cells to docetaxel by enhancing proliferative capacity. Furthermore, we showed that overexpression of RUNX3 could inactivate the AKT/GSK3ß/ß-catenin signaling pathway in the docetaxel-resistant cells. Importantly, co-transfection of RUNX3 and constitutively active Akt1 could reverse the effects of RUNX3 overexpression, while treatment with the MK-2206 (AKT inhibitor) mimicked the effects of RUNX3 overexpression in docetaxel-resistant human lung adenocarcinoma cells. Immunohistochemical analysis revealed that decreased RUNX3 expression was correlated with high expression of Akt1 and decreased sensitivity of patients to docetaxel-based chemotherapy. Taken together, our results suggest that epigenetic downregulation of RUNX3 can induce docetaxel resistance in human lung adenocarcinoma cells by activating AKT signaling and increasing expression of RUNX3 may represent a promising strategy for reversing docetaxel resistance in the future.

The role of Aurora A in hypoxia-inducible factor 1α-promoting malignant phenotypes of hepatocelluar carcinoma.

Overexpression of both hypoxia-inducible factor 1α (HIF-1α) and Aurora A has been found in hepatocellular carcinoma (HCC). However, whether HIF-1α and Aurora A synergistically promote malignant phenotypes of HCC cells is unknown. The purpose of this study was to investigate the roles and functional correlation of HIF-1α and Aurora A in HCC progression. Immunohistochemistry was performed to detect HIF-1α and Aurora A protein expression in 55 primary HCC and corresponding non-tumor tissues and their clinical significance. Gene knockout technology using short hairpin RNA (shRNA) was used to knockdown expression of HIF-1α or Aurora A and analyze their effects on malignant phenotypes of HCC cells. The transcriptional regulation of Aurora A by HIF-1α and the possible downstream molecular signaling pathways were also determined. Results showed that hypoxia could induce the increased expression of HIF-1α and Aurora A in HCC cells. Also, shRNA-mediated HIF-1α downregulation could lead to the decreased Aurora A expression and inhibition of growth or invasion in HCC cells. Moreover, HIF-1α could transcriptionally regulate Aurora A expression by binding to hypoxia-responsive elements in the Aurora A promoter and recruiting the coactivator-p300/CBP. Additionally, shRNA-mediated Aurora A knockdown could mimic the effects of HIF-1α downregulation on phenotypes of HCC cells, and overexpression of Aurora A could partially rescue the phenotypical changes of HCC cells induced by HIF-1α downregulation. Further research indicated that activation of Akt and p38-MAPK signaling pathways mediated the downstream effects of HIF-1α and Aurora A in HCC cells under hypoxic condition. Taken together, our findings indicated that Aurora A might be a key regulator of HIF-1α-promoting malignant phenotypes of HCC by activation of Akt and p38-MAPK signaling pathways.

MicroRNA-650 was a prognostic factor in human lung adenocarcinoma and confers the docetaxel chemoresistance of lung adenocarcinoma cells via regulating Bcl-2/Bax expression.

Increasing evidence shows that dysregulation of microRNAs (miRNAs) is involved in malignant transformation. We investigated the clinical significance of miR-650 and its involvement in chemoresistance to docetaxel. Our results showed that the relative expression level of miR-650 was significantly higher in LAD tissues than in corresponding nontumor tissues and high level of miR-650 expression was found to be significantly associated with high incidence of lymph node metastasis, advanced clinical stage and poor prognosis of LAD patients. Univariate and multivariate analyses indicated that high miR-650 expression was an independent prognostic factor for survival. Also, we found that the level of miR-650 in LAD tissues was correlated with the response of patients to docetaxel-based chemotherapy. Silencing of miR-650 could increase the in vitro sensitivity of docetaxel-resistant LAD cells to docetaxel, while upregulation of miR-650 decreased the sensitivity of parental LAD cells to docetaxel both in vitro and in vivo. Additionally, silencing of miR-650 could enhance the caspase-3-dependent apoptosis, which might be correlated with the decreased ratio of Bcl-2/Bax. Further researches suggested that inhibitor of growth 4 (ING4) was a direct target of miR-650. Downregulated or upregulated ING4 expression could partially rescue the effects of miR-650 inhibitor or mimics in docetaxel-resistant or parental LAD cells. Furthermore, we found that ING4 was upregulated in docetaxel-responding LAD tissues, and its expression was inversely correlated with miR-650. Thus, miR-650 is a novel prognostic marker in LAD and its expression is a potential indicator of chemosensitivity to docetaxel-based chemotherapy regimen.

Let-7c governs the acquisition of chemo- or radioresistance and epithelial-to-mesenchymal transition phenotypes in docetaxel-resistant lung adenocarcinoma.

MicroRNA (miRNA) expression and functions have been reported to contribute to phenotypic features of tumor cells. Although targets and functional roles for many miRNAs have been described in lung adenocarcinoma (LAD), their pathophysiologic roles in phenotypes of chemoresistant LAD cells are still largely unclear. Previously, docetaxel (DTX)-resistant LAD cell lines (SPC-A1/DTX and H1299/DTX) were established by our laboratory and displayed chemo- or radioresistance and mesenchymal features with enhanced invasiveness and motility. Unbiased miRNA profiling indicated that let-7c (MIRLET7C) was significantly downregulated in SPC-A1/DTX cells. Ectopic let-7c expression increased the in vitro and in vivo chemo- or radiosensitivity of DTX-resistant LAD cells through enhanced apoptosis, reversal of epithelial-to-mesenchymal phenotypes, and inhibition of in vivo metastatic potential via inactivation of Akt phosphorylation, whereas a let-7c inhibitor decreased the chemo- or radiosensitivity of parental cells. Further investigation suggested that let-7c significantly reduced the luciferase activity of a Bcl-xL 3'-UTR-based reporter, concordant with reduced Bcl-xL protein levels. Additionally, siRNA-mediated Bcl-xL knockdown mimicked the same effects of let-7c precursor, and enforced Bcl-xL expression partially rescued the effects of let-7c precursor in DTX-resistant LAD cells. Furthermore, we found that Bcl-xL was significantly upregulated in DTX-nonresponding LAD tissues, and its expression was inversely correlated with let-7c expression. This study suggests an important role for let-7c in the molecular etiology of chemoresistant lung adenocarcinoma.

Cisplatin pretreatment enhances anti-tumor activity of cytokine-induced killer cells.

AIM: To investigate whether cisplatin (DDP) enhances the anti-tumor activity of cytokine- induced killer (CIK) cells in a murine colon adenocarcinoma model. METHODS: Tumor size and weight served as indicators of therapeutic response. Immunohistochemistry was performed to observe intratumoral lymphocyte infiltration and tumor microvessel density. Changes in the percentage of regulatory T (Treg) cells within the spleens of tumor-bearing mice preconditioned with DDP were monitored using flow cytometry. RESULTS: A marked T cell-dependent, synergistic anti-tumor effect of the combined therapy was observed (1968 ± 491 mm³ vs 3872 ± 216 mm³; P = 0.003). Preconditioning chemotherapy with DDP augmented the infiltration of CD3+ T lymphocytes into the tumor mass and reduced the percentage of both intratumoral and splenic Treg cells. CONCLUSION: Preconditioning with DDP markedly enhances the efficacy of adoptively transferred CIK cells, providing a potential clinical modality for the treatment of patients with colorectal cancer.