Lianmei Zhao

The tumor-suppressive function of miR-1 by targeting LASP1 and TAGLN2 in esophageal squamous cell carcinoma.

This study determined the expression of microRNA‐1 in esophageal squamous cell carcinoma (ESCC) tissue and cell lines to evaluate its effects on clinicopathological parameters and its target genes LASP1 and TAGLN2.

Ethanol extract of Forsythia suspensa root induces apoptosis of esophageal carcinoma cells via the mitochondrial apoptotic pathway

Forsythia suspensa root is used in the treatment of fever and jaundice in Traditional Chinese Medicine. In the present study, the anti-tumor activity of the ethanolic extract of Forsythia suspensa root (FSREE) against esophageal carcinoma cells was investigated in vitro and in vivo and its anti-cancer mechanism was examined. The results revealed that FSREE, rather than Forsythia suspensa ethanolic extracts from the leaf (FSLEE) and fruit (FSFEE) exhibited marked anti-tumor activity towards human esophageal cancer cells. FSREE induced cancer cell apoptosis and growth arrest by downregulating B-cell lymphoma (Bcl)-2, Bcl-extra large and myeloid cell leukemia 1, while upregulating Bcl-2-associated X protein, Bcl-2 antagonist of cell death and phorbol-12-myristate-13-acetate-induced protein 1. This led to the activation of poly(ADP ribose) polymerase, caspase-3 and caspase-9, but not caspase-8. Furthermore, the anti-cancer activity of FSREE was associated with a decreased level of phosphorylated Janus kinase/signal transducer and activator of transcription 3 and extracellular-signal-regulated kinase signaling activity. It was also observed that the levels of cytochrome c were elevated in the cytoplasm, accounting for the loss of mitochondrial membrane potential in the TE-13 cells upon treatment with FSEER. In addition, FSEER inhibited the growth of esophageal cancer cells in xenograft models and no detectable toxicity was present in the lung or liver tissues. These observations provided further evidence of the anti-tumor effect of FSEER and may be of importance to further examine the potential role of Forsythia suspensa root as a therapeutic agent in esophageal carcinoma therapy.

An ester extract of Cochinchina momordica seeds induces differentiation of melanoma B16 F1 cells via MAPKs signaling.

Cochinchina momordica seeds (CMS) have been widely used due to antitumor activity by Mongolian tribes of China. However, the details of the underlying mechanisms remain unknown. In the present study, we found that an EtOAc (ethyl ester) extract of CMS (CMSEE) induced differentiation and caused growth inhibition of melanoma B16 F1 cells. CMSEE at the concentration of 5-200 μg/ml exhibited strongest anti-proliferative effects on B16 F1 cells among other CMS fractions (water or petroleum ether). Moreover, CMSEE induced melanoma B16 F1 cell differentiation, characterized by dendrite-like outgrowth, increasing melanogenesis production, as well as enhancing tyrosinase activity. Western blot analysis showed that sustained phosphorylation of p38 MAP accompanied by decrease in ERK1/2 and JNK dephosphorylation were involved in CMSEE-induced B16 F1 cell differentiation. Notably, 6 compounds that were isolated and identified may be responsible for inducing differentiation of CMSEE. These results indicated that CMSEE contributes to the differentiation of B16 F1 cells through modulating MAPKs activity, which may throw some light on the development of potentially therapeutic strategies for melanoma treatment.

Prevention effects of Schisandra polysaccharide on radiation-induced immune system dysfunction.

In this study, we investigate the efficacy of SP (Schisandra polysaccharide) in prevention of radiation-induced immune dysfunction and discussed the underlying mechanisms with a Bal/bc mouse model. The data demonstrated that SP could reverse the decreases in the number of white blood cells and lymphocytes in peripheral blood. In addition, the immunoglobulin G (IgG) and complement C3 in blood serum were all decreased after radiation and SP could restore this radiation disorder. Furthermore, SP could reverse the deregulation of CD3(+)CD4(+) and CD3(+)CD8(+) T cell subsets in peripheral blood and thymus of mice after radiotherapy. We also performed terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and Immunohistochemistry (IHC) to investigate the apoptosis and underlying mechanisms of SP in thymus. Data showed that radiation-induced apoptosis of thymocytes could be reversed by SP through inducing upregulation of Bcl-2 expression and downregulation of Fas and Bax levels. Furthermore, SP has no any side-effects on immunity of normal mice. In conclusion, our results indicated that SP could effectively prevent immune injury during radiotherapy by protecting the immune system. This valuable information should be of assistance in choosing a rational design for therapeutic interventions of prevention immune system damage in the radiation treatment.

P-Hydroxycinnamaldehyde Induces B16-F1 Melanoma Cell Differentiation via the RhoA-MAPK Signaling Pathway

Background/Aims: Due to its antitumor and gastroprotective properties, cochinchina momordica seed (CMS), has been widely used to treat cancer patients in Asia. Our previous reports have shown that CMS is able to induce the differentiation of B16-F1 melanoma cells. However, its functional component and mechanism remain unclear and are addressed in this study. Methods and Results: CMSP (p-hydroxycinnamaldehyde isolated from CMS) inhibited the proliferation, migration and invasiveness of B16-F1 cells both in vivo and in vitro. CMSP also induced the differentiation of B16-F1 cells, as characterized by dendrite-like outgrowth, increased melanogenesis and enhanced tyrosinase activity. Furthermore, CMSP treatment reduced the level of malignant markers of melanoma, specifically S-100B and melanoma-derived growth regulatory protein precursor (MIA), in a concentration-dependent manner. According to a western blot analysis, B16-F1 cells treated with CMSP exhibited a sustained increase in p-P38 and decreased activities of ERK and JNK. Our data further indicated that the downregulation of GTP-RhoA, which was mediated by increased cAMP release, was involved in CMSP-induced changes in MAPK, while LPA (Lysophosphatidic acid) partially reversed CMSP-induced B16 cell differentiation. Conclusion: These results demonstrated that CMSP-induced differentiation of B16F1 cells may occur through the RhoA-MAPK axis, which suggests a new potential strategy for melanoma treatment.

Periplocin Extracted from Cortex Periplocae Induced Apoptosis of Gastric Cancer Cells via the ERK1/2-EGR1 Pathway

Background/Aims: Periplocin is extracted from the traditional herbal medicine cortex periplocae, which has been reported to suppress the growth of cancer cells. However, little is known about its effect on gastric cancer cells. Methods: Gastric cancer cells were treated with periplocin, and cell viability was assessed using MTS assay. Flow cytometry and TUNEL staining were performed to evaluate apoptosis, and protein expression was examined by western blotting. Microarray analysis was used to screen for changes in related genes. Results: We found that periplocin had an inhibitory effect on gastric cancer cell viability in a dose-dependent manner. Periplocin inhibited cell viability via the ERK1/2-EGR1 pathway to induce apoptosis. Periplocin also inhibited the growth of tumor xenografts and induced apoptosis in vivo. Conclusion: Our results show that periplocin inhibits the proliferation of gastric cancer cells and induces apoptosis in vitro and in vivo, indicating its potential to be used as an antitumor drug.

Mda-7/IL-24 enhances sensitivity of B cell lymphoma to chemotherapy drugs

Interleukin-24 (IL-24) is a cytokine encoded by a tumor suppressor gene of the IL-10 family, also known as the melanoma differentiation associated gene-7 (Mda-7) and first discovered in human melanoma cells. Mda-7/IL-24 has been shown to inhibit the proliferation of various human tumor cell lines, but its effect on the sensitivity of B cell lymphoma to chemotherapy agents is not yet clear. The present study investigated the effects of Mda-7/IL-24 overexpression on the sensitivity of human B cell lymphoma cells to chemotherapy, as well as its mechanism of action. The sensitivity of stable Mda-7/IL-24 overexpressing Raji and Daudi cells to cis-diamminedichloroplatinum (CDDP), epirubicin and vinblastine (VCR) were assessed by the MTS method, and the IC50 value calculated. Cell apoptosis and the intracellular accumulation of Rhodamine-123 were assayed by flow cytometry. The expression of multidrug resistance gene 1 (MDR1), B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI1), topoisomerase II (Topo II) and multidrug resistance-related protein 1 (MRP1) mRNA and protein were analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting, respectively. In addition, western blot analysis was also used to investigate the effect of Mda-7/IL-24 on activity of GTP-RhoA-ERK signaling pathway in Raji and Daudi cells. Growth inhibition and apoptosis rates of Mda-7/IL-24 overexpressing Raji and Daudi cells were higher than those of non-transfected cells and cells transfected with vector alone when treated with CDDP, epirubicin and VCR. The IC50 values of CDDP, epirubicin and VCR were lower for Mda-7/IL-24-overexpressing Raji and Daudi cells than for non-transfected cells and cells transfected with empty vector. Intracellular accumulation of Rhodamine-123 and the expression of Topo II were higher, while the levels of MDR1, BMI and MRP1 mRNA and protein were lower, in Mda-7/IL-24 overexpressing Raji and Daudi cells. Furthermore, the activities of GTP-RhoA-ERK signaling pathway in Raji and Daudi cells were suppressed. These results indicated that Mda-7/IL-24 enhanced the sensitivity of B lymphoma cells to chemotherapy agents by altering the expression of multidrug-resistance genes via downregulating GTP-RhoA-ERK signaling pathway, suggesting that treatment of B cell lymphomas with Mda-7/IL-24 could avoid MDR.

C/D-Box Snord105b Promotes Tumorigenesis in Gastric Cancer via ALDOA/C-Myc Pathway

Background/Aims: Small nucleolar RNAs (snoRNAs) play an important role in carcinogenesis. In this study, we identified a C/D box snoRNA, snord105b, and further investigated the function and mechanism of the snord105b in gastric cancer (GC). Methods: The expression level of snord105b in GC tissures, sera and cell lines were detected by qRT-PCR. Cell viability was assessed using MTS assay. Transwell and wound healing assay were performed to evaluate migration and invasion, and protein expression was examined by western blotting. ChIRP and MS analysis was used to seek for the special binding protein of snord105b. Results: The snord105b was upregulated and associated with tumor size, differentiation, and pathological stage in GC. Snord105b affected proliferation, migration and invasion in multiple GC cell lines. The oncoqenic activity of snord105b was also confirmed with in vivo data. Mechanistically, snord105b specifically bound to ALDOA and affected C-myc, which plays a key role in carcinogenesis and tumor development. Conclusion: Snord105b appears to be a novel oncogene and is clinically and functionally involved in the development of GC. Targeting snord105b and its pathway may provide new biomarkers or potential treatments for patients with GC.

miR-200c inhibits TGF-β-induced-EMT to restore trastuzumab sensitivity by targeting ZEB1 and ZEB2 in gastric cancer

Gastric cancer is the fifth most common malignancy in the world, with Eastern Asia as one of areas with the highest incidence rates. Trastuzumab, a HER2-targeting antibody, combined with chemotherapy has been successfully employed for the gastric cancer patients with HER2 overexpression/amplification. However, trastuzumab resistance is a major problem in clinical practice. Here we observed that the trastuzumab-resistant gastric cancer cell line NCI-N87/TR expressed high levels of epithelial–mesenchymal transition factors and demonstrated increased migration and invasion capability compared with NCI-N87 cells. Downregulated E-cadherin and increased N-cadherin, TGF-β, ZEB1, ZEB2, TWIST1, and Snail were detected in NCI-N87/TR cells. We also found that miR-200c was downregulated in NCI-N87/TR cells compared with parental cells NCI-87 by qRT-PCR. Treatment with TGF-β downregulated the expression of miR-200c and upregulated ZEB2, and significantly decreased the trastuzumab sensitivity of NCI-N87 cells. miR-200c restored trastuzumab sensitivity and inhibited migration and invasion through suppressing ZEB1 and ZEB2. In summary, TGF-β/ZEB2 axis plays an encouraging role in trastuzumab resistance of gastric cancer, while miR-200c overexpression downregulates ZEB1/ZEB2 and resensitizes drugs resistance. Our findings might provide a potential therapeutic strategy for trastuzumab resistance of gastric cancer.

Mda‑7/IL‑24 induces the differentiation of B cell lymphoma via activation of the P38 mitogen activated protein kinase signaling pathway

Interleukin 24 (IL‑24) is a unique cytokine encoded by the melanoma differentiation associated gene‑7 (Mda‑7), and was first discovered inhuman melanoma cells. Exogenous Mda‑7/IL‑24 has been shown to inhibit the proliferation and invasion of a broad spectrum of human cancer cells, but its effect on the differentiation of B cell lymphoma is not yet clear. To the best of our knowledge, the present study demonstrated for the first time that overexpressing Mda‑7/IL‑24 can induce differentiation in human B cell lymphomacells, and the underlying mechanism was investigated. The proliferation of stable Mda‑7/IL‑24 overexpressing Raji and Daudi cells was assessed by the MTS method. The immunophenotype, apoptosis level and cell cycle distribution of Raji and Daudi cells were analyzed by flow cytometry. The expression of PR domain zinc finger protein 1 (Blimp1) and B‑cell lymphoma 6 (Bcl6) were analyzed by western blotting. Additionally, western blotting assay was also performed to study the effect of Mda‑7/IL‑24 on the activity of the P38 mitogen activated protein kinase (MAPK) signaling pathway in Raji and Daudi cells. Proliferation of Raji and Daudi cells overexpressing Mda‑7/IL‑24 was inhibited significantly, compared with those of parent cells and cells transfected with the empty vector alone. Apoptosis was not involved in the proliferation inhibition, while the cell cycle was arrested in G1 phase in the Raji and Daudi cells overexpressing Mda‑7/IL‑24. Overexpressing Mda‑7/IL‑24 resulted in a significantly decreased expression of cluster of differentiation (CD)10, and increased expression of CD45 and CD138 in the cell surface of Raji and Daudi cells. The expression of Blimp1 was upregulated, while the levels of Bcl6 protein was downregulated, in Raji and Daudi cells overexpressing Mda‑7/IL‑24. Furthermore, the activities of the P38 MAPK signaling pathway in lymphoma cells were upregulated. These results indicated that Mda‑7/IL‑24 could induce terminal differentiation of B lymphoma cells by regulating the expression of Blimp1 and Bcl6 via altering the P38 MAPK signaling pathway, suggesting that Mda‑7/IL‑24 may therefore be a potential differentiation therapeutic agent to be applied in clinical treatment of B cell lymphoma.