scholarly journals Genetic transformation of apical meristematic shoots in the banana cultivar ‘Williams’

Bionatura ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 1462-1465
Author(s):  
Liliana Villao ◽  
José Flores ◽  
Efrén Santos-Ordóñez

Bananas and plantains (Musa spp.) are among the most critical socioeconomic crops globally, being a staple food for millions of people in the tropics and an essential component for the export market, including the subtropics. Besides conventional breeding, genetic improvement of bananas and plantains could be performed through genetic engineering and new breeding techniques. Furthermore, plant tissue culture is essential for these technologies, including developing embryogenic cell suspensions and in vitro plants. The transient and stable genetic transformation could be performed from in vitro plants, shortening Musa transgenic lines development compared to genetic transformation while using embryogenic cell suspension. In this study, a genetic transformation protocol was established from banana apical meristems for the ‘Williams’ cultivar (genotype AAA). The protocol was based on the co-cultivation of the explants (whole in vitro plants or bisected meristematic tissues derived from in vitro plants) with Agrobacterium tumefaciens strain LBA4404 harboring two binary vectors denominated pLVCIBE1 (cassette: MabHIPP promoter::luc2::Tnos, P35S::hpt::Tnos) and pLVCIBE2 (cassette: P35S::luc2::Tnos, P35S::hpt::Tnos), independently. The stable genetic transformation was obtained by subculturing in vitro banana plants in selection medium (12.5µg/mL of hygromycin) for 8 weeks from bisected meristematic tissue transformation. Genetic transformation was confirmed in vivo with the use of the luciferase reporter gene system. Furthermore, PCR was performed on DNA extracted from leaves of regenerated transgenic in vitro plants after 8 weeks of selection, confirming stable genetic transformation. Therefore, genetic transformation was achieved in the apical meristematic tissue of in vitro banana plants with co-cultivation of Agrobacterium tumefaciens.

Tumor Biology ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 11-26
Author(s):  
Maike Busch ◽  
Natalia Miroschnikov ◽  
Jaroslaw Thomas Dankert ◽  
Marc Wiesehöfer ◽  
Klaus Metz ◽  
...  

BACKGROUND: Retinoblastoma (RB) is the most common childhood eye cancer. Chemotherapeutic drugs such as etoposide used in RB treatment often cause massive side effects and acquired drug resistances. Dysregulated genes and miRNAs have a large impact on cancer progression and development of chemotherapy resistances. OBJECTIVE: This study was designed to investigate the involvement of retinoic acid receptor alpha (RARα) in RB progression and chemoresistance as well as the impact of miR-138, a potential RARα regulating miRNA. METHODS: RARα and miR-138 expression in etoposide resistant RB cell lines and chemotherapy treated patient tumors compared to non-treated tumors was revealed by Real-Time PCR. Overexpression approaches were performed to analyze the effects of RARα on RB cell viability, apoptosis, proliferation and tumorigenesis. Besides, we addressed the effect of miR-138 overexpression on RB cell chemotherapy resistance. RESULTS: A binding between miR-138 and RARα was shown by dual luciferase reporter gene assay. The study presented revealed that RARα is downregulated in etoposide resistant RB cells, while miR-138 is endogenously upregulated. Opposing RARα and miR-138 expression levels were detectable in chemotherapy pre-treated compared to non-treated RB tumor specimen. Overexpression of RARα increases apoptosis levels and reduces tumor cell growth of aggressive etoposide resistant RB cells in vitro and in vivo. Overexpression of miR-138 in chemo-sensitive RB cell lines partly enhances cell viability after etoposide treatment. CONCLUSIONS: Our findings show that RARα acts as a tumor suppressor in retinoblastoma and is downregulated upon etoposide resistance in RB cells. Thus, RARα may contribute to the development and progression of RB chemo-resistance.


2021 ◽  
Author(s):  
Feng Ying Zhang ◽  
Xia Li ◽  
Ting Ting Huang ◽  
Mei Ling Xiang ◽  
Lin Lin Sun ◽  
...  

Abstract Background Long intergenic non-coding RNA 00839 (LINC00839) has been verified as a cancer-promoting gene in malignancies. However, the significance of LINC00839 in nasopharyngeal carcinoma (NPC) has yet to be elaborated, as well as its underlying mechanism.Methods LINC00839 and miR-454-3p relative expression levels in NPC cells were examined by qRT-PCR. The growth of cells was examined by CCK-8 and colony formation assays. Cell migration and invasion were examined by wound healing and Transwell experiment, respectively. The binding sequence of LINC00839 and miR-454-3p was confirmed by the luciferase reporter gene experiment. The regulatory function of LINC00839 and miR-454-3p on c-Met was investigated by western blot.Results Here, we revealed that LINC00839 was elevated in NPC. Both LINC00839 knockdown and upregulation of miR-454-3p suppressed NPC cells proliferation, invasive capacity and EMT in vitro. Besides, LINC00839 was validated as a miR-454-3p “sponge”, and upregulation of LINC00839 could reverse miR-454-3p-mediated functions in NPC C666-1 and SUNE-1 cells. Furthermore, c-Met was determined to be targeted by miR-454-3p. Notably, c-Met was downregulated by LINC00839 knockdown through sponging miR-454-3p. In vivo, LINC00839 knockdown resulted in a slower tumor growth.Conclusions Altogether, knockdown of LINC00839 inhibits the aggressive properties of NPC cells via sponging miR-454-3p and regulating c-Met.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jiajia Jiang ◽  
Rong Li ◽  
Junyi Wang ◽  
Jie Hou ◽  
Hui Qian ◽  
...  

Circular RNA CDR1as has been demonstrated to participate in various cancer progressions as miRNA sponges. The exact underlying mechanisms of CDR1as on gastric cancer (GC) metastasis remain unknown. Here, we found that CDR1as knockdown facilitated GC cell migration and invasion while its overexpression inhibited the migration and invasion abilities of GC cells in vitro and in vivo. Moreover, epithelial-mesenchymal transition- (EMT-) associated proteins and MMP2 and MMP9 were downregulated by CDR1as. Bioinformatics analysis combined with dual-luciferase reporter gene assays, western blot, RT-qPCR analysis, and functional rescue experiments demonstrated that CDR1as served as a miR-876-5p sponge and upregulated the target gene GNG7 expression to suppress GC metastasis. In summary, our findings indicate that CDR1as suppresses GC metastasis through the CDR1as/miR-876-5p/GNG7 axis.


Author(s):  
Zhihui Huang ◽  
Wenming Ma ◽  
Jinhuai Xiao ◽  
Xiaoyu Dai ◽  
Weiqi Ling

Abstract The dysregulation of circular RNAs (circRNAs) has been identified in various human diseases. Here, we probed into the potential mechanism of circRNA_0092516 in osteoarthritis (OA). The expression of circRNA_0092516 was tested by quantitative real-time PCR. MTT, flow cytometry and western blot were applied to confirm the functions of circRNA_0092516 in vitro. Besides, RNA pull-down and dual-luciferase reporter gene experiments were applied to probe into the mechanism. circRNA_0092516 was raised in the tissues of OA patients and chondrocytes stimulated by IL-1β. The potential mechanism analysis expounded that circRNA_0092516 bound to miR-337-3p, and the interference with circRNA_0092516 boosted chondrocyte proliferation and restrained cell apoptosis through the miR-337-3p/phosphatase and tensin homolog (PTEN) axis, thereby improving OA. In-vivo experiments expounded that circRNA_0092516 regulated cartilage production through miR-337-3p. Overall, our data expounded that the interference with circRNA_0092516 boosted chondrocyte proliferation and restrained cell apoptosis through the miR-337-3p/PTEN axis, eventually slowed down the progress of OA.


2015 ◽  
Vol 37 (5) ◽  
pp. 1956-1966 ◽  
Author(s):  
Shiping Liu ◽  
Peng Feng

Background/Aims: Increasing evidence has shown that miR-203 plays important role in human cancer progression. However, little is known about the function of miR-203 in osteosarcoma (OS). Methods: The expression of miR-203 in OS tissues and cell lines were examined by qRT-PCR. The biological role of miR-20 in OS cell proliferation was examined in vitro and in vivo. The targets of miR-203 were identified by a luciferase reporter gene assay. Results: miR-203 was down regulated in OS tissues and cell lines; decreased miR-203 was associated with a poor overall survival in OS patients. Restoration of miR-203 expression reduced cell growth in vitro and suppressed tumorigenicity in vivo. In contrast, inhibition of miR-203 stimulated OS cell growth both in vitro and in vivo. In addition, TANK binding kinase 1 (TBK1) was identified as a direct target of miR-203; overexpression of TBK1 partly reversed the suppressive effects of miR-203. Furthermore, TBK1 was found up-regulated and inversely correlated with miR-203 in OS tissues. Conclusion: Taken together, these findings suggest that miR-203 acts as a tumor suppressor via regulation of TBK1 expression in OS progression, and miR-203 may be a promising therapeutic target for OS.


1996 ◽  
Vol 16 (7) ◽  
pp. 3789-3798 ◽  
Author(s):  
X Huet ◽  
J Rech ◽  
A Plet ◽  
A Vié ◽  
J M Blanchard

Transcription of the gene coding for cyclin A, a protein required for S-phase transit, is cell cycle regulated and is restricted to proliferating cells. To further explore transcriptional regulation linked to cell division cycle control, a genomic clone containing 5' flanking sequences of the murine cyclin A gene was isolated. When it was fused to a luciferase reporter gene, it was shown to function as a proliferation-regulated promoter in NIH 3T3 cells. Transcription of the mouse cyclin A gene is negatively regulated by arrest of cell proliferation. A mutation of a GC-rich sequence conserved between mice and humans is sufficient to relieve transcriptional repression, resulting in a promoter with constitutively high activity. In agreement with this result, in vivo footprinting reveals a protection of the cell cycle-responsive element in G0/early G1 cells which is not observed at later stages of the cell cycle. Moreover, the footprint is present in dimethyl sulfoxide-induced differentiating and not in proliferating Friend erythroleukemia cells. Conversely, two other sites, which in vitro bind ATF-1 and NF-Y, respectively, are constitutively occupied throughout cell cycle progression.


2021 ◽  
Author(s):  
Han Wang ◽  
Yingying Zhou ◽  
Siyang Zhang ◽  
Ya Qi ◽  
Min Wang

Abstract Background Small nucleolar RNA host gene 16 (SNHG16) and pre-mRNA processing factor 6(PRPF6) play vital roles in regulatory mechanisms of multiple cancers, but the mechanisms in ovarian cancer (OC) remains poorly understood. Methods The expression of SNHG16 transcripts-SNHG16-L/S in OC tissues were analyzed by real-time PCR (RT-PCR). The expression of PRPF6 in OC tissues were detected by Immunohistochemistry (IHC). Tumorigenesis, epithelial-to-mesenchymal transition (EMT) and PTX-resistance were detected by western blot, transwell, CCK-8 assays, colony formation assays and flow cytometry analyses. Molecular interactions were examined by dual-luciferase reporter gene assay, RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP). Results The results indicated the expression of SNHG16-L/S was opposite in chemo-resistance and chemo-sensitivity tissues of OC. And SNHG16-L/S had different effects on the progression and PTX-resistance of OC cells. SNHG16-L inhibited GATA binding protein 3 (GATA3) transcription through CCAAT/enhancer-binding protein b (CEBPB) to further promote tumorigenesis, EMT and PTX-resistance of OC. Moreover, PRPF6 was upregulated in chemo-resistance tissues of OC. PRPF6 promoted tumorigenesis and PTX-resistance in vitro and in vivo. Mechanistically, PRPF6 induced the alternative splicing of SNHG16 to downregulate SNHG16-L, which further mediated progression and PTX-resistance through upregulating GATA3 in OC. Conclusions Totally, the results demonstrated that PRPF6 promoted progression and PTX-resistance in OC through SNHG16-L/CEBPB/GATA3 axis. Thus, PRPF6 may become a valuable target for OC therapy.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Xiaofei Ma ◽  
Baoyi Yin ◽  
Shuai Guo ◽  
Talha Umar ◽  
Junfeng Liu ◽  
...  

Background. Persistent endometritis caused by bacterial infections has lethal effects on the reproductive performance of dairy cattle, which compromises animal welfare and delays or prevents pregnancy. The microRNA (miRNA) miR-34 family plays a pivotal role in the inflammatory process; however, the precise mechanism of miR-34a in endometritis has not been thoroughly elucidated to date. Methods. In this study, the endometrium of cows diagnosed with endometritis was harvested for bacterial culture and Gram staining to evaluate bacterial contamination of the uterus. Based on this, a bovine endometrial epithelial cell (BEND) inflammation model and a mouse model stimulated with lipopolysaccharide (LPS) in vitro and in vivo were constructed. Cell viability was assessed by CCK-8, trypan blue staining, and flow cytometry. H&E was applied to histopathological analysis. Immunohistochemical, immunofluorescence, qRT-PCR, and western blot assays were performed to measure the mRNA and protein expression of relevant genes. Online databases, plasmid construction, and dual-luciferase reporter gene assays were used to predict and validate the interaction between miR-34a and its target gene LGR4. Finally, mice were injected vaginally with a local antagomir to validate the role of miR-34a in murine uterine inflammation. Results. In this study, we observed that Gram-negative bacteria, represented by Escherichia coli, are the predominant pathogenic agents responsible for the recurrent occurrence of endometritis in dairy cows. Further, miR-34a was found to repress the expression of LGR4 by targeting the 3 ′ untranslated region (3 ′ UTR) of LGR4. miR-34a was upregulated in bovine uterine tissues and bovine endometrial epithelial cells stimulated with LPS. miR-34a induced the release of the proinflammatory cytokines IL-1β, IL-6, and TNF-α by activating the phosphorylation of NF-κB p65. Furthermore, IL-1β upregulated miR-34a transcription and downregulated LGR4 expression in an IL-1β-dependent manner. Conclusions. Taken together, our study confirmed that miR-34a is regulated by IL-1β and suppresses the level of the LGR4 3 ′ UTR, which in turn exacerbates the inflammatory response. Thus, the knockdown of miR-34a might be a new direction for the treatment of endometritis.


2021 ◽  
Author(s):  
Zhang Jieling ◽  
Li Kai ◽  
Zheng Huifen ◽  
Zhu Yiping

Abstract Background: MicroRNAs play an important role in the genesis and progression of tumors, including colorectal cancer (CRC), which has a high morbidity and mortality rate. In this research, the role of miR-495-3p and HMGB1 in CRC was investigated.Methods: We performed qRT-PCR to detect the expression of miR-495-3p in colorectal cancer tissues and cell lines. Functional experiments such as CCK-8 assay, EDU assay, Transwell assay and apoptosis assay were conducted to explore the effects of miR-495-3p on the proliferation, migration and apoptosis of CRC cells in vitro. Then, the use of database prediction, dual-luciferase reporter gene assay and functional experiments verified the role of miR-495-3p target gene HMGB1 in CRC. Finally, rescue experiments was performed to investigate whether overexpression of HMGB1 could reverse the inhibitory effect of miR-495-3p on CRC cell proliferation in vivo and in vitro.Results: miR-495-3p was down-regulated in colorectal cancer tissues and cell lines, and could inhibit the proliferation and migration of colorectal cancer cells, and promote cell apoptosis. The database prediction and dual-luciferase reporter gene assay showed that HMGB1 was the downstream target gene of miR-495-3p. We finally demonstrated that miR-495-3p inhibited CRC cell proliferation by targeting HMGB1 in vitro and in vivo.Conclusion: Our research shows that miR-495-3p inhibits the progression of colorectal cancer by down-regulating the expression of HMGB1, which indicates that miR-495-3p may become a potential therapeutic target for colorectal cancer.


2021 ◽  
Author(s):  
Jian Zhang ◽  
Yao Lu ◽  
Yangming Mao ◽  
Yue Yu ◽  
Tianyu Wu ◽  
...  

Abstract Background: Mesenchymal stem cells (MSCs) activated with IFN-γ elicit more powerful physical effects. Exosomes (Exos) secreted from MSCs have protective against myocardial injury. The aim of this study was to investigate whether Exsos derived from IFN-γ-pretreated MSCs exhibit more potent cardioprotective function and the underlying mechanisms. Methods: Exos were isolated from MSCs (Ctrl-Exo) and IFN-γ-primed MSCs (IFN-γ-Exo) and were then delivered to H9c2 cells or human umbilical vein endothelial cells (HUVECs) in vitro under oxygen and glucose deprivation (OGD) condition or in vivo in an infarcted rat heart. RNA sequencing was to identify the different expressed functional transcription factor (TF). Quantitative reverse transcription-PCR (qPCR) was to confirm the upregulated TF and miRNA in IFN-γ-primed MSCs. Dual-luciferase reporter gene assay were to analyze the transcriptional regulation of miRNAs by STAT1. The target of miR-21-5p (miR-21) was disclosed by luciferase reporter assays and qPCR. The function of BTG2 was verified in vitro under OGD condition.Result: IFN-γ-Exo accelerated migration, tube-like structure formation, and prevented H9c2 from OGD-induced apoptosis. Similarly, IFN-γ-Exo leaded to further reduction in fibrosis size, reduced cardiomyocyte apoptosis and improved cardiac function compared to Ctrl-Exo. miR-21 was significantly upregulated in both IFN-γ-primed MSCs and IFN-γ-Exo. STAT1 transcriptionally induced miR-21 expression. Up-regulated miR-21 can inhibit the expression of BTG2. BTG2 promoted H9c2 cells apoptosis and reversed the protective effect of miR-21 under OGD environment.Conclusion: IFN-γ-Exo have enhanced therapeutic efficacy against acute MI possibly through promoting angiogenesis and anti-apoptotic effect through increasing the level of miR-21, which directly targeted on BTG2.


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