A novel TOX3-WDR5-ABCG2 signaling axis regulates the progression of colorectal cancer by accelerating stem-like traits and chemoresistance.

The eradication of cancer stem cells (CSCs) with drug resistance confers the probability of local tumor control after chemotherapy or targeted therapy. As the main drug resistance marker, ABCG2 is also critical for colorectal cancer (CRC) evolution, in particular cancer stem-like traits expansion. Hitherto, the knowledge about the expression regulation of ABCG2, in particular its upstream transcriptional regulatory mechanisms, remains limited in cancer, including CRC. Here, ABCG2 was found to be markedly up-regulated in CRC CSCs (cCSCs) expansion and chemo-resistant CRC tissues and closely associated with CRC recurrence. Mechanistically, TOX3 was identified as a specific transcriptional factor to drive ABCG2 expression and subsequent cCSCs expansion and chemoresistance by binding to -261 to -141 segments of the ABCG2 promoter region. Moreover, we found that TOX3 recruited WDR5 to promote tri-methylation of H3K4 at the ABCG2 promoter in cCSCs, which further confers stem-like traits and chemoresistance to CRC by co-regulating the transcription of ABCG2. In line with this observation, TOX3, WDR5, and ABCG2 showed abnormal activation in chemo-resistant tumor tissues of in situ CRC mouse model and clinical investigation further demonstrated the comprehensive assessment of TOX3, WDR5, and ABCG2 could be a more efficient strategy for survival prediction of CRC patients with recurrence or metastasis. Thus, our study found that TOX3-WDR5/ABCG2 signaling axis plays a critical role in regulating CRC stem-like traits and chemoresistance, and a combination of chemotherapy with WDR5 inhibitors may induce synthetic lethality in ABCG2-deregulated tumors.

MED27 plays a tumor-promoting role in breast cancer progression by targeting KLF4.

The mediator complex usually cooperates with transcription factors to be involved in RNA polymerase II-mediated gene transcription. As one component of this complex, MED27 has been reported in our previous studies to promote thyroid cancer and melanoma progression. However, the precise function of MED27 in breast cancer development remains poorly understood. Here, we found that MED27 was more highly expressed in breast cancer samples than in normal tissues, especially in triple-negative breast cancer, and its expression level was elevated with the increase in pathological stage. MED27 knockdown in triple-negative breast cancer cells inhibited cancer cell metastasis and stemness maintenance, which was accompanied by downregulation of the expression of EMT- and stem traits-associated proteins, and vice versa in non-triple-negative breast cancer. Furthermore, MED27 knockdown sensitized breast cancer cells to epirubicin treatment by inducing cellular apoptosis and reducing tumorsphere-forming ability. Based on RNA-seq, we identified KLF4 as the possible downstream target of MED27. KLF4 overexpression reversed the MED27 silencing-mediated arrest of cellular metastasis and stemness maintenance capacity in breast cancer in vitro and in vivo. Mechanistically, MED27 transcriptionally regulated KLF4 by binding to its promoter region at positions -156 to +177. Collectively, our study not only demonstrated the tumor-promoting role of MED27 in breast cancer progression by transcriptionally targeting KLF4, but also suggested the possibility of developing the MED27/KLF4 signaling axis as a potential therapeutic target in breast cancer.

BPTF inhibition antagonizes colorectal cancer progression by transcriptionally inactivating Cdc25A.

As the largest subunit of the nuclear remodeling factor complex, Bromodomain PHD Finger Transcription Factor (BPTF) has been reported to be involved in tumorigenesis and development in several cancers. However, to date, its functions and related molecular mechanisms in colorectal cancer (CRC) are still poorly defined and deserve to be revealed. In this study, we uncovered that, under the expression regulation of c-Myc, BPTF promoted CRC progression by targeting Cdc25A. BPTF was found to be highly expressed in CRC and promoted the proliferation and metastasis of CRC cells through BPTF specific siRNAs, shRNAs or inhibitors. Based on RNA-seq, combined with DNA-pulldown, ChIP and luciferase reporter assay, we proved that, by binding to -178/+107 region within Cdc25A promoter, BPTF transcriptionally activated Cdc25A, thus accelerating the cell cycle process of CRC cells. Meanwhile, BPTF itself was found to be transcriptionally regulated by c-Myc. Moreover, BPTF knockdown or inactivation was verified to sensitize CRC cells to chemotherapeutics, 5-Fluorouracil (5FU) and Oxaliplatin (Oxa), c-Myc inhibitor and cell cycle inhibitor not just at the cellular level in vitro, but in subcutaneous xenografts or AOM/DSS-induced in situ models of CRC in mice, while Cdc25A overexpression partially reversed BPTF silencing-caused tumor growth inhibition. Clinically, BPTF, c-Myc and Cdc25A were highly expressed in CRC tissues simultaneously, the expression of any two of the three was positively correlated, and their expressions were highly relevant to tumor differentiation, TNM staging and poor prognosis of CRC patients. Thus, our study indicated that the targeted inhibition of BPTF alone, or together with chemotherapy and/or cell cycle-targeted therapy, might act as a promising new strategy for CRC treatment, while c-Myc/BPTF/Cdc25A signaling axis is expected to be developed as an associated set of candidate biomarkers for CRC diagnosis and prognosis prediction.

TRIP4 transcriptionally activates DDIT4 and subsequent mTOR signaling to promote glioma progression.

In spite of significant advances in the understanding of glioma biology and pathology, survival remains poor. Therefore, it is still of great significance to further explore the key factors involved in tumorigenesis and development in glioma and find potential new therapeutic targets. Here, we show that thyroid hormone receptor interactor 4 (TRIP4) is highly expressed in glioma cells and tissues. Patients of glioma with high expression of TRIP4 possess poor overall survival. Knockdown of TRIP4 inhibited tumor cell proliferation, metastasis, and apoptosis suppression, whereas overexpression of TRIP4 displays the opposite effects. Further research showed that TRIP4 promoted glioma progression through regulating DDIT4 expression and subsequent activation of mTOR signaling. DDIT4 overexpression restored the inhibition of tumor growth by TRIP4 knockdown in vitro and in vivo. Consistently, mTOR activity inhibition reversed TRIP4 overexpression-mediated tumor promotion in vitro and in vivo. Moreover, molecular mechanism exploration demonstrates that TRIP4 functions as a specific transcriptional activator to anchor at the promoter region of DDIT4 gene (-196 to -11) to regulate its transcription and such regulation was affected by HIF1α. Clinically, TRIP4 expression is positively correlated with DDIT4 expression in glioma samples based on tissue microarray analysis and both of their high expression predicts the malignancy of the disease. Altogether, our findings identify TRIP4 as a critical promoter of glioma progression by targeting DDIT4 and mTOR signaling successively and suggest that TRIP4-DDIT4 axis has potential to be a novel therapeutic target in glioma treatment.

Rosmarinic acid alleviates ethanol-induced lipid accumulation by repressing fatty acid biosynthesis.

Recent studies have demonstrated that rosmarinic acid is a valuable natural product for treatment of alcoholic liver disease. However, the mechanisms whereby rosmarinic acid improves alcoholic liver disease remain unclear. Here we performed experiments using a non-transformed mouse hepatocyte cell line (AML12). Oil-red O staining demonstrated that rosmarinic acid reduced ethanol-induced lipid accumulation. It was shown that rosmarinic acid prevented ethanol-induced elevation of the malondialdehyde level. We also found that rosmarinic acid inhibited ethanol-induced mRNA expression of tumor necrosis factor-α and interleukin 6. Metabolomics analysis revealed that rosmarinic acid ameliorated ethanol-induced fatty acid biosynthesis in the cytoplasm. In addition, palmitic acid was a candidate biomarker in cells exposed to ethanol or ethanol plus rosmarinic acid. Rosmarinic acid prevented the ethanol-induced increase in sorbitol that is a component of the polyol pathway. Moreover, we confirmed that rosmarinic acid attenuated ethanol-induced mRNA expression of fatty acid synthase, probably by modulating the AMPK/SREBP-1c pathway. Furthermore, rosmarinic acid prevented the ethanol-induced decrease in eight metabolites that are involved in mitochondrial metabolism, including glycine and succinic acid which are the components of carnitine synthesis. These results provide a crucial insight into the molecular mechanism of rosmarinic acid in alleviating ethanol-induced injury.

Myricetin Ameliorates Ethanol-Induced Lipid Accumulation in Liver Cells by Reducing Fatty Acid Biosynthesis.

SCOPE: Alcoholic liver disease is a serious threat to human health. The development of drug candidates from complementary and alternative medicines is an attractive approach. Myricetin can be found in fruit, vegetables, and herbs. This study investigates the protective effect of myricetin on ethanol-induced injury in mouse liver cells. METHODS AND RESULTS: Oil-red O staining, assays of oxidative stress and measurements of inflammatory markers in mouse AML12 liver cells collectively demonstrate that myricetin elicits a curative effect on ethanol-induced injury. Next, the role of myricetin in the metabolic regulation of ethanol pathology in liver cells is assessed by gas chromatography coupled with mass spectrometry. Myricetin inhibits ethanol-stimulated fatty acid biosynthesis. Additionally, dodecanoic acid may be proposed as a potential biomarker related to ethanol pathology or myricetin therapy. It is also observed that myricetin enhances ethanol-induced inhibition of the mitochondrial electron transport chain. Moreover, fumaric acid is found to be a candidate biomarker related to ethanol toxicity or myricetin therapy. Quantitative reverse-transcription-PCR shows that ethanol-induced fatty acid synthase and sterol regulatory element-binding protein-1c mRNA levels are alleviated by myricetin. Finally, myricetin increases ethanol-induced inhibition of phosphorylation of AMP-activated protein kinase. CONCLUSION: These results elucidate the pharmacological mechanism of myricetin on ethanol-induced lipid accumulation.

[Study on different digestion methods for determination of twelve metal elements in the plant Platycodon Grandi florum (Jacq.) A. DC. by FAAS].

In the present paper the effects of different digestion methods on determining the amount of metal elements in the plant platycodon grandi florum (Jacq.) A. DC. by flame atomic absorption spectrophotometry(FAAS) are reported. FAAS method was established for the determination of K, Mg, Ca, Cu, Zn, Mn, Fe, Co, Ni, Cd and Cr and Pb in the plant platycodon grandi florum (Jacq.) A. DC. The samples were incinerated and followed by digestion with HNO3-HClO (phi, 4 : 1) at 90-95 degrees C and normal pressure. In the meantime, the optimum parameters of FAAS and effects of solution medium on the results were discussed. The analytical results of K, Mg, Ca, Mn, Fe, Cu and Zn were 13 226.32, 922.57, 1 710.72, 9.23, 336.66, 8.75 and 19.62 microg x g(-1) respectively, while Co, Ni, Cd, Cr and Pb were not checked out in the samples. The results showed that the recovery of standard addition was 95.45Y-105.50% and the relative standard deviation (n = 9) was 0.34%-5.78%. The method is quick, simple and convenient, and the results are satisfactory.

[Determination of the amount of 13 metal elements in the rape pollen from different regions by flame atomic absorption spectrophotometry].

The objective of the present paper was to determine the amount of metal elements in the rape pollen from different regions by flame atomic absorption spectrophotometry (FAAS). FAAS method was established for the determination of K, Na, Ca, Mg, Fe, Co, Ni, Cu, Zn, Mn, Cd, Cr and Pb in the rape pollen. The samples were incinerated and then digested with HNO3-HClO4 (V : V = 4 : 1) at 90-95 degrees C and under normal pressure. In the meantime, the optimum parameters of FAAS and the effects of solution medium on the results were studied. The analytical results of K, Na, Ca, Mg, Fe, Cu, Zn and Mn rape pollen from different habitats respectively were 4 248.00, 75.77, 312.10, 856.61, 599.53, 8.78, 27.82, 22.54 microg x g(-1) and 7 585.75, 242.56, 287.88, 699.43, 1 020.65, 10.25, 40.44, 30.97 microg x g(-1), while Co, Ni, Cd, Cr and Pb were not checked out in the samples. The results showed that the recovery of standard addition was 95.22%-105.49%, and the RSD(n = 9) was 0.30%-5.00%. The characteristic method is quick, simple and convenient, and the results are satisfactory.

[Determination of six metal elements in plant Bupleurum scorzoneri folium Willd. by flame atomic absorption spectrophotometry (FAAS)].

The objective in this paper was to determine the amount of metal elements in the Plant Bupleurum scorzoneri folium Willd. by flame atomic absorption spectrophotometry (FAAS). FAAS method was established for the determination of Ca, Mg, Fe, Cu, Zn and Pb in the Plant Bupleurum scorzoneri folium Willd. after digestion with HNO3-HClO4 (V : V= 4 : 1) at 90-95 degrees C and at normal pressure. In the meantime, the optimum parameters of FAAS and the effects of solution medium on the results were studied. The analytical results of Ca, Mg, Fe, Cu and Zn were 5,588.9, 1,790.5, 869.3, 78.4, 44.3 microg x g(-1) respectively, and Pb was not checked out in the samples. The results showed that the recovery of standard addition was 99.57%-102.10%, the relative standard deviation (n= 9) was 0.18%-2.26%. The method is quick, simple and convenient, and the results are satisfactory.

[Determination of thirteen metal elements in the plant Foeniculum vulgare Mill. by flame atomic absorption spectrophotometry].

The objective of the paper is to determine the amount of metal elements of Na, K, Mg, Ca, Cu, Zn, Mn, Fe, Co, Ni, Cd, Cr and Pb in the planted Foeniculum vulgare Mill. by flame atomic absorption spectrophotometry (FAAS), after the cinefaction and the digestion with HNO3-HClO4 (phi 4:1) at 90-95 degrees C and normal pressure. The optimum parameters of FAAS and the effects of solution medium on the results were investigated. The analytical results show that the amount of Na, K, Mg, Ca, Mn, Fe, Cu, Zn and Pb was 1508.7, 27653.0, 2036.0, 4848.1, 24.8, 323.5, 15.2, 23.7 and 10.8 microg x g(-1), respectively, and that of Co, Ni, Cd and Cr was not checked out in the samples. The recovery of standard addition is 97.45%-102.50%, the relative standard deviation (n=9) was 0.34%-2.77%. The characteristic method is quick, simple and convenient and the results are satisfactory.

[Determination of fifteen metal elements in Cynomorium songaricum by flame atomic absorption spectrophotometry (FAAS)].

A FAAS method was established for the determination of Na, K, Mg, Ca, Cu, Zn, Fe, Mn, Ni, Co, Pb, Cr, Cd, Ag and Au in Cynomorium songaricum after digestion with HNO3-HClO4 (phi 4:1) at 90-95 degrees C and at normal pressure. In this paper, the parameters in FAAS were studied. The analytical results of Na, K, Mg, Ca, Fe, Zn, Cu, Mn, Pb, Ni and Ag were 13,572.0, 14,260.0, 358.3, 168.3, 238.5, 19.4, 5.9, 3.4, 2.6, 1.3 and 0.4 microg x g(-1) respectively and Co, Cr, Cd and Au were not found in the samples. The results showed that the recovery of standard addition was 97.8%-104.5%, and the relative standard deviation (n = 9) was 0.2%-5.0%. The method is fast, simple and convenient. The results were satisfactory.