Targeting LEF1-mediated epithelial-mesenchymal transition reverses lenvatinib resistance in hepatocellular carcinoma.

Acquired resistance is a significant hindrance to clinical application of lenvatinib in unresectable hepatocellular carcinoma (HCC). Further in-depth investigation of resistance mechanisms can help to develop additional therapeutic strategies to overcome or delay resistance. In our study, two lenvatinib-resistant (LR) HCC cell lines were established by treatment with gradient increasing concentration of lenvatinib, named Hep3B-LR and HepG2-LR. Interestingly, continuous lenvatinib treatment reinforced epithelial-mesenchymal transition (EMT), cell migration, and cell invasion. Gene set enrichment analysis (GSEA) enrichment analysis of RNA-sequencing from Hep3B-LR and corresponding parental cells revealed that activation of Wnt signaling pathway was involved in this adaptive process. Active ß-catenin and its downstream target lymphoid enhancer binding factor 1 (LEF1) were significantly elevated in LR HCC cells, which promoted lenvatinib resistance through mediating EMT-related genes. Data analysis based on Gene Expression Omnibus (GEO) and the Cancer Genome Atlas Program (TCGA) databases suggests that LEF1, as a key regulator of EMT, was a novel molecular target linked to lenvatinib resistance and poor prognosis in HCC. Using a small-molecule specific inhibitor ICG001 and knocking down LEF1 showed that targeting LEF1 restored the sensitivity of LR HCC cells to lenvatinib. Our results uncover upregulation of LEF1 confers lenvatinib resistance by facilitating EMT, cell migration, and invasion of LR HCC cells, indicating that LEF1 is a novel therapeutic target for overcoming acquired lenvatinib resistance.

ETV4 facilitates angiogenesis in hepatocellular carcinoma by upregulating MMP14 expression.

Abnormal vascularization plays a crucial role in cell proliferation, tumor invasion and metastasis of hepatocellular carcinoma (HCC). It has been reported that ETV4 functions as an oncogenic gene in driving the carcinogenesis and progression, and promoting invasion and metastasis of HCC. However, the function of ETV4 on angiogenesis in HCC remains unclear. In the current study, immunohistochemistry showed that knockdown of ETV4 reduced angiogenesis in HCC xenograft tumor tissues. In vitro, tube formation assay verified that ETV4 expression promoted angiogenesis through simulating the angiogenic environment in HCC cells. Transcriptome sequencing indicated that MMP14 was one of the differentially expressed genes enriched in angiogenesis process. Subsequently, it was confirmed that MMP14 was regulated by ETV4 at the transcription level in HCC cells, clinical tissue samples and online databases. Further, we demonstrated that MMP14 induced angiogenesis in ETV4-mediated HCC microenvironment. Collectively, this research further reveals the biological mechanism of ETV4 in promoting the migration and invasion of HCC, and provides novel mechanistic insights and strategic guidance for anti-angiogenic therapy in HCC.

Asparagus officinalis combined with paclitaxel exhibited synergistic anti-tumor activity in paclitaxel-sensitive and -resistant ovarian cancer cells.

PURPOSE: Although paclitaxel is a promising first-line chemotherapeutic drug for ovarian cancer, acquired resistance to paclitaxel is one of the leading causes of treatment failure, limiting its clinical application. Asparagus officinalis has been shown to have anti-tumorigenic effects on cell growth, apoptosis, cellular stress and invasion of various types of cancer cells and has also been shown to synergize with paclitaxel to inhibit cell proliferation in ovarian cancer. METHODS: Human ovarian cancer cell lines MES and its PTX-resistant counterpart MES-TP cell lines were used and were treated with Asparagus officinalis and paclitaxel alone as well as in combination. Cell proliferation, cellular stress, invasion and DMA damage were investigated and the synergistic effect of a combined therapy analyzed. RESULTS: In this study, we found that Asparagus officinalis combined with low-dose paclitaxel synergistically inhibited cell proliferation, induced cellular stress and apoptosis and reduced cell invasion in paclitaxel-sensitive and -resistant ovarian cancer cell lines. The combined treatment effects were dependent on DNA damage pathways and suppressing microtubule dynamics, and the AKT/mTOR pathway and microtubule-associated proteins regulated the inhibitory effect through different mechanisms in paclitaxel-sensitive and -resistant cells. CONCLUSION: These findings suggest that the combination of Asparagus officinalis and paclitaxel have potential clinical implications for development as a novel ovarian cancer treatment strategy.

Comparative Analysis of the Endophytic Bacterial Diversity of Populus euphratica Oliv. in Environments of Different Salinity Intensities.

Populus euphratica Oliv. has a high tolerance for drought, salinity, and alkalinity. The main purpose of this study is to explore the effects of environments of different salinity intensities on endophytic community structure and the possible roles of endophytes in the tolerance of host plants. The characterization of endogenous bacteria in diversity has been investigated by using the Illumina high-throughput sequencing technique. The research showed that endophytic bacteria of P. euphratica in an extremely saline environment had low species diversity, especially in sap tissue. The dominant phyla in all groups were Proteobacteria, Actinobacteria, and Bacteroidetes. Notably, Firmicutes (relative abundance >5%) was a different dominant phylum in the samples from the high-saline environment compared with the relatively low-saline-environment group. The linear discriminant analysis effect size (LEfSe) analysis found that there were significant differences in different saline environments of Cytophagaceae (family), Rhodobacteraceae (family), and Rhodobacterales (order). These results indicated that the composition of the endogenous bacterial community was related to the growth environment of host plants. The predictive analysis of KEGG pathways and enzymes showed that the abundance of some enzymes and metabolic pathways of endophytes of P. euphratica increased with the increase of soil salinity, and most of the enzymes were related to energy metabolism and carbohydrate metabolism. These findings suggested that the endogenous bacteria of the host plant had different expression mechanisms under different degrees of stress, and this mechanism was very obvious in the distribution of endophytes, while the function of the endogenous bacteria needs to be further explored. IMPORTANCE Euphrates poplar (Populus euphratica Oliv.), as the only tree species that grows in the desert, has tenacious vitality with the characteristics of cold tolerance, drought tolerance, salt-alkali tolerance, and wind-sand resistance. P. euphratica has a long growth cycle and a high growth rate, which can break wind, fix sand, green the environment, and protect farmland, making it an important afforestation tree species in arid and semiarid areas. The area of P. euphratica in Xinjiang accounts for 91.1% of its area in China. Studying the endophytic bacteria of P. euphratica can give people a systematic understanding of it and the adaptability of the endogenous flora to the host and special environments. In this study, by analyzing the endophytic bacteria of P. euphratica in different saline-alkali regions of Xinjiang, it was found that the bacteria in different tissues of P. euphratica changed with the change of soil salinity. Especially in the sap tissue of P. euphratica under extremely high salinity, the diversity of endogenous bacteria was significantly lower than that in other tissues. These differential bacteria under different salinities were mostly related to the stress resistance of themselves and the host. Not only that, we also selected a strain of Bacillus with high stress resistance from the tissues of P. euphratica, which can survive under the extreme conditions of 10% NaCl and pH 11. We obtained a genome completion map of this strain, named it Bacillus haynesii P19 (GenBank accession no. PRJNA648288), and tried to use it for fermentation but in a different work, so as to develop it into a promising industrial fermentation chassis bacterium. Therefore, this study was of great significance for the understanding of endophytic bacteria in P. euphratica and the acquisition of extremophilic microbial resources.

Asparagus officinalis Exhibits Anti-Tumorigenic and Anti-Metastatic Effects in Ovarian Cancer.

Ovarian cancer is one of the leading causes of female cancer death. Emerging evidence suggests that many dietary natural products have anti-tumorigenic activity, including that of asparagus officinalis. The current study aimed to assess the anti-tumorigenic and anti-metastatic effects of asparagus officinalis on serous ovarian cancer cell lines and a transgenic mouse model of high grade serous ovarian cancer. Asparagus officinalis decreased cellular viability, caused cell cycle G1 phase arrest and induced apoptosis in the OVCAR5 and SKOV3 cells. Induction of apoptosis and inhibition of cell proliferation was rescued by the pan-caspase inhibitor, Z-VAD-FMK, implying that its cytotoxic effects were mainly dependent on caspase pathways. Asparagus officinalis increased levels of ROS and decreased mitochondrial membrane potential with corresponding increases in PERK, Bip, Calnexin PDI and ATF4 in both cell lines. Treatment with asparagus officinalis also reduced ability of adhesion and invasion through epithelial-mesenchymal transition and reduction of VEGF expression. The combination of Asparagus officinalis with paclitaxel had synergistic anti-proliferative activity. Furthermore, Asparagus officinalis significantly inhibited tumor growth and reduced serum VEGF in a genetically engineered mouse model of ovarian cancer under obese and lean conditions, accompanied with a decrease in the expression of Ki67, VEGF and phosphorylated S6, and in an increase in phosphorylation of AMPK in the ovarian tumor tissues. Overall, our data provide a pre-clinical rationale for asparagus officinalis in the prevention and treatment of ovarian cancer as a novel natural product.

Perivascular cell-derived extracellular vesicles stimulate colorectal cancer revascularization after withdrawal of antiangiogenic drugs.

Antiangiogenic tyrosine kinase inhibitors (AA-TKIs) have become a promising therapeutic strategy for colorectal cancer (CRC). In clinical practice, a significant proportion of cancer patients temporarily discontinue AA-TKI treatment due to recurrent toxicities, economic burden or acquired resistance. However, AA-TKI therapy withdrawal-induced tumour revascularization frequently occurs, hampering the clinical application of AA-TKIs. Here, this study demonstrates that tumour perivascular cells mediate tumour revascularization after withdrawal of AA-TKI therapy. Pharmacological inhibition and genetic ablation of perivascular cells largely attenuate the rebound effect of CRC vascularization in the AA-TKI cessation experimental settings. Mechanistically, tumour perivascular cell-derived extracellular vehicles (TPC-EVs) contain Gas6 that instigates the recruitment of endothelial progenitor cells (EPCs) for tumour revascularization via activating the Axl pathway. Gas6 silence and an Axl inhibitor markedly inhibit tumour revascularization by impairing EPC recruitment. Consequently, combination therapy of regorafenib with the Axl inhibitor improves overall survival in mice metastatic CRC model by inhibiting tumour growth. Together, these data shed new mechanistic insights into perivascular cells in off-AA-TKI-induced tumour revascularization and indicate that blocking the Axl signalling may provide an attractive anticancer approach for sustaining long-lasting angiostatic effects to improve the therapeutic outcomes of antiangiogenic drugs in CRC.

A Meta-Surface Antenna Array Decoupling (MAAD) Method for Mutual Coupling Reduction in a MIMO Antenna System.

In this paper, a method to reduce the inevitable mutual coupling between antennas in an extremely closely spaced two-element MIMO antenna array is proposed. A suspended meta-surface composed periodic square split ring resonators (SRRs) is placed above the antenna array for decoupling. The meta-surface is equivalent to a negative permeability medium, along which wave propagation is rejected. By properly designing the rejection frequency band of the SRR unit, the mutual coupling between the antenna elements in the MIMO antenna system can be significantly reduced. Two prototypes of microstrip antenna arrays at 5.8 GHz band with and without the metasurface have been fabricated and measured. The matching bandwidths of antennas with reflection coefficient smaller than -15 dB for the arrays without and with the metasurface are 360 MHz and 900 MHz respectively. Using the meta-surface, the isolation between elements is increased from around 8 dB to more than 27 dB within the band of interest. Meanwhile, the total efficiency and peak gain of each element, the envelope correlation coefficient (ECC) between the two elements are also improved by considerable amounts. All the results demonstrate that the proposed method is very efficient for enhancing the performance of MIMO antenna arrays.

Structural analysis and anti-complement activity of polysaccharides from Kjellmaniella crsaaifolia.

Two polysaccharides, named KCA and KCW, were extracted from Kjellmaniella crassifolia using dilute hydrochloric acid and water, respectively. Composition analysis showed that these polysaccharides predominantly consisted of fucose, with galactose, mannose and glucuronic acid as minor components. After degradation and partial desulfation, electrospray ionization mass spectrometry (ESI-MS) was performed, which showed that the polysaccharides consisted of sulfated fucooligosaccharides, sulfated galactofucooligosaccharides and methyl glycosides of mono-sulfated/multi-sulfated fucooligosaccharides. The structures of the oligomeric fragments were further characterized by electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS2 and ESI-CID-MS3). Moreover, the activity of KCA and KCW against the hemolytic activity of both the classical and alternative complement pathways was determined. The activity of KCA was found to be similar to KCW, suggesting that the method of extraction did not influence the activity. In addition, the degraded polysaccharides (DKCA and DKCW) displayed lower activity levels than the crude polysaccharides (KCA and KCW), indicating that molecular weight had an effect on activity. Moreover, the desulfated fractions (ds-DKCA and ds-DKCW) showed less or no activity, which confirmed that sulfate was important for activity. In conclusion, polysaccharides from K. crassifolia may be good candidates for the treatment of diseases involving the complement pathway.