Comparative transcriptome analysis reveals the key genes and pathways involved in drought stress response of two wheat (Triticum aestivum L) varieties.

Drought stress results in significant yield losses in wheat production. Although studies have reported a number of wheat drought tolerance genes, a deeper understanding of the tolerance mechanisms is required for improving wheat tolerance against drought stress. In this study, we found that "Deguo 2" exhibited higher tolerance to drought than "Truman". Transcriptomics analysis enabled identification of 6084 and 7146 differentially expressed genes (DEGs), mainly mapping flavonoid biosynthesis, plant hormone, phenolamides and antioxidant pathways and revealed altered expression levels of about 700 genes. Exogenous melatonin application enhanced wheat tolerance against drought stress. Co-expression analysis showed that bHLH and bZIP transcription factors may be involved in the regulation of various pathway genes. Take together, these results provide new insights for us on exploring the crosstalk between phytohormones and secondary metabolites, and will deepen the understanding of the complex tolerance mechanisms against drought stress in wheat.

Bioengineering Approaches for the Pancreatic Tumor Organoids Research and Application.

Pancreatic cancer is a highly lethal form of digestive malignancy that poses significant health risks to individuals worldwide. Chemotherapy-based comprehensive treatment is the primary therapeutic approach for midlife and late-life patients. Nevertheless, the heterogeneity of the tumor and individual genetic backgrounds result in substantial variations in drug sensitivity among patients, rendering a single treatment regimen unsuitable for all patients. Conventional pancreatic cancer tumor organoid models are capable of emulating the biological traits of pancreatic cancer and are utilized in drug development and screening. However, these tumor organoids can still not mimic the tumor microenvironment (TME) in vivo, and the poor controllability in the preparation process hinders translation from essential drug screening to clinical pharmacological therapy. In recent years, many engineering methods with remarkable results have been used to develop pancreatic cancer organoid models, including bio-hydrogel, co-culture, microfluidic, and gene editing. Here, this work summarizes and analyzes the recent developments in engineering pancreatic tumor organoid models. In addition, the future direction of improving engineered pancreatic cancer organoids is discussed for their application prospects in clinical treatment.

Primary Human Pancreatic Cancer Cells Cultivation in Microfluidic Hydrogel Microcapsules for Drug Evaluation.

Chemotherapy is an essential postoperative treatment for pancreatic cancer, while due to the lack of effective drug evaluation platforms, the therapeutic outcomes are hampered by tumor heterogeneity among individuals. Here, a novel microfluidic encapsulated and integrated primary pancreatic cancer cells platform is proposed for biomimetic tumor 3D cultivation and clinical drug evaluation. These primary cells are encapsulated into hydrogel microcapsules of carboxymethyl cellulose cores and alginate shells based on a microfluidic electrospray technique. Benefiting from the good monodispersity, stability, and precise dimensional controllability of the technology, the encapsulated cells can proliferate rapidly and spontaneously form 3D tumor spheroids with highly uniform size and good cell viability. By integrating these encapsulated tumor spheroids into a microfluidic chip with concentration gradient channels and culture chambers, dynamic and high-throughput drug evaluation of different chemotherapy regimens could be realized. It is demonstrated that different patient-derived tumor spheroids show different drug sensitivity on-chip, which is significantly consistent with the clinical follow-up study after the operation. The results demonstrate that the microfluidic encapsulated and integrated tumor spheroids platform has great application potential in clinical drug evaluation.

Zinc finger protein 91 accelerates tumour progression by activating ß-catenin signalling in pancreatic cancer.

OBJECTIVES: ZFP91, an E3 ligase, has been reported to possess cancer-promoting functions. This study aimed to elucidate the exact role of ZFP91 in tumour progression of pancreatic cancer and underlying mechanisms. MATERIALS AND METHODS: We analysed the correlation between ZFP91 expression and pancreatic cancer through TCGA and GEO data sets. Growth curve, colony formation, wound healing and transwell invasion assays were conducted to evaluate proliferation, migration and invasion of lentivirus transfected pancreatic cancer cells. GSEA and Western blot analysis were performed to validate the regulatory effect of ZFP91 on ß-catenin. Drug response curve and orthotopic implantation model reflected the sensitivity of chemotherapies. RESULTS: ZFP91 overexpression is prevalent in pancreatic cancer and negatively correlated with overall survival. ZFP91 knock-down attenuated proliferation, migration and invasion of pancreatic cancer cells. ß-catenin was a downstream gene of ZFP91, and its agonist could reverse the phenotype. ZFP91 promoted EMT and chemoresistance in pancreatic cancer. CONCLUSIONS: We demonstrated that ZFP91 promoted pancreatic cancer proliferation, migration and invasion through activating ß-catenin signalling. EMT and chemoresistance were also regulated by ZFP91. ZFP91 might be a potential therapeutic target for pancreatic cancer.

Fluctuation of ROS regulates proliferation and mediates inhibition of migration by reducing the interaction between DLC1 and CAV-1 in breast cancer cells.

The aim of our present study was to elucidate the effects of up-regulation and down-regulation of intracellular reactive oxygen species (ROS) level on proliferation, migration, and related molecular mechanism. Breast cancer cells were treated by catalase or H2O2. MTT, colony formation assay, and Hoechst/PI staining were used to evaluate proliferation and apoptosis. The level of intracellular ROS was measured by dichlorodihydrofluorescein diacetate probes. The ability of migration was detected by wound healing. Western blotting and coimmunoprecipitation (co-IP) were used to determine the expression of DLC1 and CAV-1 and their interaction. Our data indicated that up-regulation of intracellular ROS induced by H2O2 significantly inhibited proliferation and induced apoptosis accompanying G1 cell cycle arrest and elevated expression of p53. For cell migration, either up-regulation or down-regulation of ROS induced migration inhibition with reduction of interaction between DLC1 and CAV-1. Our results suggested that up-regulation of intracellular ROS inhibited proliferation by promoting expression of p53 and induced G1 cycle arrest and apoptosis. Fluctuation of ROS inhibited migration through reducing the interaction between DLC1 and CAV-1.

Flavone inhibits migration through DLC1/RhoA pathway by decreasing ROS generation in breast cancer cells.

Tumor suppressor protein deleted in liver cancer 1 (DLC1) is a RhoGTPase-activating protein (RhoGAP) and inhibits cancer cell migration by inactivating downstream target protein RhoA. A few studies have reported the regulations of reactive oxygen species (ROS) on RhoGAP. In this study, we investigated flavone (the core structure of flavonoids)-induced regulation on ROS generation and DLC1/RhoA pathway in MCF-7 and MDA-MB-231 breast cancer cells and explored whether flavone-induced upregulation of DLC1 is mediated by ROS. Our results showed that flavone decreased ROS production and inhibited cell migration through DLC1/RhoA pathway. To further investigate the role of ROS in flavone-induced regulation on DLC1/RhoA pathway, hydrogen peroxide was added to restore the ROS levels. Flavone-induced upregulation of DLC1 expression, downregulation of RhoA activity, and inhibition of cell migration were all restrained by hydrogen peroxide. We also found that flavone increased DLC1 stability by inhibiting DLC1 protein degradation in breast cancer cells. In summary, our study demonstrated that flavone inhibited cell migration through DLC1/RhoA pathway by decreasing ROS generation and suppressed DLC1 degradation in MCF-7 and MDA-MB-231 breast cancer cells.

Resveratrol Attenuates Oxidative Stress and Extends Life Span in the Annual Fish Nothobranchius guentheri.

Resveratrol is a natural polyphenol derived mainly from the skin of grapes and from red wine. Resveratrol prolongs life span in several invertebrates, but this function is not found in mice. Our recently published paper demonstrated that resveratrol prolonged longevity of the annual fish Nothobranchius guentheri, a promising vertebrate model for anti-aging research. However, the anti-aging process by resveratrol remains largely unexplored, and little is known about its effects on oxidative stress. In this study, by long-term supplementation of resveratrol from sexual maturity onward in the annual fish, we detected survivorship and oxidative stress at three different developmental stages in vivo. A total of 112 fish were fed with resveratrol in the concentration of 200 µg/gram food and 111 fish without resveratrol from 16 weeks of age until to the end of their lives. The mean and maximum life spans of the fish treated with resveratrol were extended by 17.34% and 17.66%, respectively, compared to the fish in control group. The markers of oxidative stress, such as the levels of reactive oxygen species (ROS), the activities of anti-oxidant enzymes, and the degree of oxidative damage, were detected at 6, 9, and 12 months, respectively. The results showed that levels of ROS and oxidative damage increased and activities of anti-oxidant enzymes appeared to decrease with age. Resveratrol treatment significantly attenuated the increase of ROS and oxidative damage and up-regulated the decrease of anti-oxidant enzyme activities induced by aging. Our results demonstrated that resveratrol decreased oxidative stress and extended life span in this short-lived fish.

H2O2 inhibits proliferation and mediates suppression of migration via DLC1/RhoA signaling in cancer cells.

BACKGROUND: RhoGTPase-activating proteins (RhoGAPs) regulate RhoGTPases in cells, but whether individual reactive oxygen species (ROS) regulate RhoGAPs is unknown. Our previous published papers have shown that deleted in liver cancer 1 (DLC1) inhibits cancer cell migration by its RhoGAP activity. The present study was designed to explore the role of H2O2 in regulation of DLC1. MATERIALS AND METHODS: We treated cells with H2O2 for 24h and phenotypic changes were analyzed by MTT, RT-PCR, Western blotting, immunofluorescence staining and wound healing assays. RESULTS: H2O2 downregulated cyclin D1 and cyclin E to inhibit proliferation, and upregulated BAX to induce apoptosis in MCF-7 cells. Compared with non-tumorigenic cells, H2O2 increased expression of DLC1 and reduced activity of RhoA in cancer cells. Stress fiber production and migration were also suppressed by H2O2 in MDA-MB-231 cells. CONCLUSIONS: Our study suggests that H2O2 inhibits proliferation through modulation of cell cycle and apoptosis-related genes, and inhibits migration by decreasing stress fibers via DLC1/RhoA signaling.