scholarly journals KRT18 Modulates Alternative Splicing of Genes Involved in Proliferation and Apoptosis Processes in Both Gastric Cancer Cells and Clinical Samples

2021 ◽  
Vol 12 ◽  
Author(s):  
Biao Chen ◽  
Ximing Xu ◽  
Dan-dan Lin ◽  
Xin Chen ◽  
Yang-tao Xu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Alternative Splicing ◽  
Quantitative Polymerase Chain Reaction ◽  
Expression Level ◽  
Clinical Samples ◽  
Rna Seq ◽  
Ags Cells ◽  
Proliferation And Apoptosis ◽  
Posttranscriptional Level

Keratin 18 (KRT18), one of the most abundant keratins in epithelial and endothelial cells, has been reported to be aberrantly expressed in many malignancies and extensively regarded as a biomarker and important regulator in multiple cancers, including gastric cancer (GC). But the molecular regulatory mechanisms of KRT18 in GC patients and cells are largely unknown. In the present study, we analyzed the expression level of KRT18 in 450 stomach adenocarcinoma tissue samples from TCGA database and found a significantly higher expression level in tumor tissues. We then explored the potential functions of KRT18 in AGS cells (human gastric adenocarcinoma cell line) by KRT18 knockdown using siRNA and whole transcriptome RNA-seq analysis. Notably, KRT18 selectively regulates expression of cell proliferation and apoptotic genes. Beyond this, KRT18 affects the alternative splicing of genes enriched in apoptosis, cell cycle, and other cancer-related pathways, which were then validated by reverse transcription–quantitative polymerase chain reaction approach. We validated KRT18-KD promoted apoptosis and inhibited proliferation in AGS cells. We then used RNA-seq data of GC samples to further demonstrate the modulation of KRT18 on alternative splicing regulation. These results together support the conclusion that KRT18 extensively modulates diverse alternative splicing events of genes enriched in proliferation and apoptosis processes. And the dysregulated splicing factors at transcriptional or posttranscriptional level by KRT18 may contribute to the alternative splicing change of many genes, which expands the functional importance of keratins in apoptotic and cell cycle pathways at the posttranscriptional level in GC.

OSI-027 alleviates oxaliplatin chemoresistance in gastric cancer cells by suppressing P-gp induction

2020 ◽  
Vol 20 ◽  
Author(s):  
En Xu ◽  
Hao Zhu ◽  
Feng Wang ◽  
Ji Miao ◽  
Shangce Du ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Cancer Cells ◽  
Mammalian Target Of Rapamycin ◽  
Cell Counting ◽  
Gastric Cancer Cells ◽  
Ags Cells ◽  
Dual Inhibitor ◽  
Induced Apoptosis

: Gastric cancer is one of the most common malignancies worldwide and the third leading cause of cancer-related death. In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin complex 1/2 (mTOR1/2) dual inhibitor, alone or in combination with oxaliplatin against gastric cancer cells in vitro. Cell counting kit-8 assays and EdU staining were performed to examine the proliferation of cancer cells. Cell cycle and apoptosis were detected by flow cytometry. Western blot was used to detect the elements of the mTOR pathway and Pgp in gastric cancer cell lines. OSI-027 inhibited the proliferation of MKN-45 and AGS cells by arresting the cell cycle in the G0/G1 phase. At the molecular level, OSI-027 simultaneously blocked mTORC1 and mTORC2 activation, and resulted in the downregulation of phosphor-Akt, phpspho-p70S6k, phosphor-4EBP1, cyclin D1, and cyclin-dependent kinase4 (CDK4). Additionally, OSI-027 also downregulated P-gp, which enhanced oxaliplatin-induced apoptosis and suppressed multidrug resistance. Moreover, OSI-027 exhibited synergistic cytotoxic effects with oxaliplatin in vitro, while a P-gp siRNA knockdown significantly inhibited the synergistic effect. In summary, our results suggest that dual mTORC1/mTORC2 inhibitors (e.g., OSI-027) should be further investigated as a potential valuable treatment for gastric cancer.

scholarly journals LncRNA CRNDE attenuates chemoresistance in gastric cancer via SRSF6-regulated alternative splicing of PICALM

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Feifei Zhang ◽  
Hui Wang ◽  
Jiang Yu ◽  
Xueqing Yao ◽  
Shibin Yang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Alternative Splicing ◽  
Noncoding Rna ◽  
De Novo ◽  
Acquired Resistance ◽  
Genetic Alterations ◽  
Clinical Samples ◽  
Autophagy Flux ◽  
Resistance To Chemotherapy

AbstractDe novo and acquired resistance, which are mainly mediated by genetic alterations, are barriers to effective routine chemotherapy. However, the mechanisms underlying gastric cancer (GC) resistance to chemotherapy are still unclear. We showed that the long noncoding RNA CRNDE was related to the chemosensitivity of GC in clinical samples and a PDX model. CRNDE was decreased and inhibited autophagy flux in chemoresistant GC cells. CRNDE directly bound to splicing protein SRSF6 to reduce its protein stability and thus regulate alternative splicing (AS) events. We determined that SRSF6 regulated the PICALM exon 14 skip splice variant and triggered a significant S-to-L isoform switch, which contributed to the expression of the long isoform of PICALM (encoding PICALML). Collectively, our findings reveal the key role of CRNDE in autophagy regulation, highlighting the significance of CRNDE as a potential prognostic marker and therapeutic target against chemoresistance in GC.

scholarly journals Transformer 2β Regulates the Alternative Splicing of Cell Cycle Regulator Genes to Promote Ovarian Cancer Cell Progression

2021 ◽  
Author(s):  
Peiying Fu ◽  
Ting Zhou ◽  
Dong Chen ◽  
ShiXuan Wang ◽  
Ronghua Liu
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Alternative Splicing ◽  
Cancer Progression ◽  
Poor Prognosis ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Expression Level

Abstract Background: Late-stage ovarian cancer (OV) has a poor prognosis and a high metastasis rate, but the underlying molecular mechanism is ambiguous. RNA binding proteins (RBPs) play important roles in posttranscriptional regulation in the contexts of neoplasia and tumor metastasis. Results: In this study, we explored the molecular functions of a canonical RBP, TRA2B, in cancer cells. TRA2B knockdown in HeLa cells and whole-transcriptome sequencing (RNA-seq) experiments revealed that the TRA2B-regulated alternative splicing (AS) profile was tightly associated with the mitotic cell cycle, apoptosis, and several cancer pathways. Moreover, hundreds of genes were regulated by TRA2B at the expression level, and their functions were enriched in cell proliferation, cell adhesion and angiogenesis, which are related to cancer progression. We also observed that AS regulation and expression regulation occurred independently by integrating the alternatively spliced and differentially expressed genes. We then explored and validated the carcinogenic functions of TRA2B by knocking down its expression in OV cells. In vivo, a high expression level of TRA2B was associated with a poor prognosis in OV patients. Conclusions: We demonstrated the important roles of TRA2B in ovarian neoplasia and OV progression and identified the underlying molecular mechanisms, facilitating the targeted treatment of OV in the future.

scholarly journals Hsa_Circular RNA_0001013 Exerts Oncogenice Effects in Gastric Cancer Via the microRNA-136/TWSG1 Axis

2022 ◽  
Author(s):  
Zhaofeng Gao ◽  
Lingyu Hu ◽  
Fei Chen ◽  
Chunhua He ◽  
Biwen Hu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Microarray Analysis ◽  
Nude Mice ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Clinical Samples ◽  
Circular Rnas

Abstract Background：Gastric cancer (GC) is one of the most principle malignant cancers in the digestive system. Moreover, the critical role of circular RNAs (circRNAs) has been identified in GC development. Methods：In this context, the purpose of research was to explore the regulatory mechanism circ_0001013, a novel circRNAs predicted by our research, in GC. The differential circRNAs and related mechanism in GC were predicted by microarray analysis. Circ_0001013, miR-136, and TWSG1 expression in GC clinical samples and cells was detected by RT-qPCR. The relationship among circ_0001013, miR-136, and TWSG was assessed by dual-luciferase reporter assay, biotin coupled probe pull-down assay, and biotin coupled miRNA capture. After gain- and loss-of-function assays in GC cells, cell proliferation, migration, invasion, and cell cycle and apoptosis were measured by EdU assay, scratch test, Transwell assay, and flow cytometry respectively. The effect of circ_0001013 on tumor growth was detected by xenograft tumor in nude mice. Results ：Microarray analysis predicted a novel circRNA, circ_0001013, was upregulated in GC, which was confirmed by RT-qPCR detection in GC tissues and cells. Besides, miR-136 was downregulated but TWSG1 was highly expressed in GC tissues. Mechanically, circ_0001013 could bind to miR-136, and miR-136 negatively targeted TWSG1 in GC cells. Silencing circ_0001013 or TWSG1 or overexpressing miR-136 decreased GC cell proliferation, migration, invasion, and cell cycle arrest and accelerated cell apoptosis. Circ_0001013 silencing decreased TWSG1 expression and inhibited transplanted tumor growth in nude mice. Conclusion：Circ_0001013 elevated TWSG1 expression by binding to miR-136, thereby exerting oncogenic effect in GC.

scholarly journals Hsa_Circular RNA_0001013 Exerts Oncogenice Effects in Gastric Cancer via the MicroRNA-136/TWSG1 Axis

2021 ◽  
Author(s):  
Zhaofeng Gao ◽  
Lingyu Hu ◽  
Fei Chen ◽  
Chunhua He ◽  
Biwen Hu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Microarray Analysis ◽  
Nude Mice ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Clinical Samples ◽  
Circular Rnas

Abstract Background：Gastric cancer (GC) is one of the most principle malignant cancers in the digestive system. Moreover, the critical role of circular RNAs (circRNAs) has been identified in GC development. Methods：In this context, the purpose of research was to explore the regulatory mechanism circ_0001013, a novel circRNAs predicted by our research, in GC. The differential circRNAs and related mechanism in GC were predicted by microarray analysis. Circ_0001013, miR-136, and TWSG1 expression in GC clinical samples and cells was detected by RT-qPCR. The relationship among circ_0001013, miR-136, and TWSG was assessed by dual-luciferase reporter assay, biotin coupled probe pull-down assay, and biotin coupled miRNA capture. After gain- and loss-of-function assays in GC cells, cell proliferation, migration, invasion, and cell cycle and apoptosis were measured by EdU assay, scratch test, Transwell assay, and flow cytometry respectively. The effect of circ_0001013 on tumor growth was detected by xenograft tumor in nude mice. Results ：Microarray analysis predicted a novel circRNA, circ_0001013, was upregulated in GC, which was confirmed by RT-qPCR detection in GC tissues and cells. Besides, miR-136 was downregulated but TWSG1 was highly expressed in GC tissues. Mechanically, circ_0001013 could bind to miR-136, and miR-136 negatively targeted TWSG1 in GC cells. Silencing circ_0001013 or TWSG1 or overexpressing miR-136 decreased GC cell proliferation, migration, invasion, and cell cycle arrest and accelerated cell apoptosis. Circ_0001013 silencing decreased TWSG1 expression and inhibited transplanted tumor growth in nude mice. Conclusion：Circ_0001013 elevated TWSG1 expression by binding to miR-136, thereby exerting oncogenic effect in GC.

Effect of upregulation of ANGPT2 by DARPP-32 on angioenesis in gastric cancer.

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 34-34
Author(s):  
Zheng Chen ◽  
Shoumin Zhu ◽  
Jun Hong ◽  
Abbes Belkhiri ◽  
Wael El-Rifai
Keyword(s):  
Gastric Cancer ◽  
Umbilical Vein ◽  
Quantitative Polymerase Chain Reaction ◽  
Mrna Level ◽  
Gastric Cancer Tissue ◽  
Cancer Tissue ◽  
Ags Cells ◽  
Tissue Samples ◽  
Over Expression ◽  
Tnf Α

34 Background: Gastric cancer is the second most frequent cause of cancer-related death worldwide. We have previously shown that Dopamine and cAMP regulated phosphoprotein MW 32 kDa (DARPP-32) and its truncated form (t-DARPP) are overexpressed in two-thirds of gastric adenocarcinomas. Angiopoietin 2 (ANGPT2) -TIE2 signaling is a secreted protein that acts as a key regulator of adult vascular homeostasis and blood vessel formation. Methods: The expression of DARPP-32 in the multi-step carcinogenesis cascade was examined using IHC analysis on 533 samples. ANGPT2 mRNA level was detected by real-time quantitative polymerase chain reaction (PCR) in 30 gastric cancer tissue samples and 30 normal gastric tissues. DARPP-32 and t-DARPP were over expressed using stable and transient expression in AGS and MKN-28 gastric cancer cell lines, lacking endogenous DARPP-32 to investigate the induction of ANGPT2 by DARPP-32 and t-DARPP. Results: We found that ANGPT2 was higher expressed in cancer samples than normal tissues from RT-PCR. We also found gastric cancer tissue samples expressed higher DARPP-32 and t-DARPP mRNA than normal gastric tissues. Over expression of DARPP-32 and t-DARPP led to a significant increase of the mRNA and protein levels of ANGPT2 as compared to empty vector control. Consistent with these findings, the condition media from DARPP-32 and t-DARRP expressing cells showed high levels of secreted ANGPT-2. TNF-α treatment induced the levels of ANGPT2 further in DARPP-32 and t-DARPP expressing cells as compared to control. Of note, this increase in NF-κB activity was significantly higher in DARPP-32 and t-DARPP expressing cells as compared to control. To confirm the angiogenic potential, we used condition media from DARPP-32 and t-DARPP expressing AGS cells and demonstrated its ability to stimulate tube formation on human umbilical vein endothelial cells (HUVEC) models than the condition medium from control cells. Conclusions: Our results suggest that DARPP-32 and t-DARPP over expression may participate in the angiogenesis of gastric cancer. The in vitro studies indicate that DARPP-32 and t-DARPP play a role in up regulation of ANGPT2 in gastric cancer cells by enhancing the TNF-α induced activation of NF-κB signaling pathway.

Bone Marrow Microenvironment Affects The Pathogenesis Of Multiple Myeloma Through Downregulation Of Alternative Splicing Factor Fox2 In Myeloma Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3085-3085
Author(s):  
Weihua Song ◽  
Chaolin Zhang ◽  
Yiguo Hu ◽  
Maria Gkotzamanidou ◽  
Parantu Shah ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Alternative Splicing ◽  
Cell Lines ◽  
Actin Polymerization ◽  
Bone Marrow Microenvironment ◽  
Splicing Factor ◽  
Expression Level ◽  
Rna Seq ◽  
Alternate Splicing

Abstract Alternate splicing is an important post translational change that alters specificity of gene function. Misregulation of alternative splicing has been implicated in number of disease processes including cancer. We have analyzed alternate splicing in myeloma using high throughput GeneChip Human Exon 1.0 ST Arrays in 170 uniformly treated patients and identified pattern of splicing as well as their impact on both overall and event free survival in myeloma. We have now further analyzed this data and identified Fox2, a RNA alternative splicing regulator, as one of the most important genes predicting clinical outcome in these patients. We observe that the expression level of Fox2 correlates with the frequency of RNA splicing and disease prognosis in MM patients. We have now further investigated the molecular role of Fox2 in myeloma. Fox2 expression was detected in all 10 MM cell lines tested at both RNA and protein levels. Immunohistochemistry staining showed a predominant nuclear localization of Fox2. We next evaluated impact of IL-6 on Fox2 expression in MM1S and RPMI8226 MM cell lines and observed dose-dependent reduction in Fox2 expression. Importantly, MM cell - bone marrow stromal cells (BMSC) interaction also led to significant inhibition of Fox2 expression in MM1S and RPMI8226 cells. Similar response was also observed using BMSC supernatants. On the other hand, IGF-1 stimulation showed slight upregulation of Fox2 in MM cell lines. We have also evaluated impact of IL-6 on Fox2 and splicing using genomewide RNA-seq and confirmed the results. Fox2 was downregulated 33% in MM1S and 37% in RPMI8226 at gene expression level. To study its role in MM, we knocked down the expression of Fox2 in MM1S and RPMI8226 cell lines by using Fox2-directed siRNA. Compared to control cell lines, Fox2 knockdown in MM cell lines did not affect the cell proliferation and survival, as measured by cell titer glo luminescent cell viability assay and annexin V and PI staining respectively. Since Fox2 has been described to plays a role in the maintenance of cell cytoskeleton, we therefore evaluated whether Fox2 might influence the migration and adhesion in MM cells. Transwell migration assay showed enhanced migration rate of Fox2-knocking down- MM1S and RPMI8226 cells versus controls. We also observed the increased cell adhesion to fibronetin in both cell lines upon Fox2 knockdown. Actin polymerization evaluated by Alexa488-conjugated phalloidin staining and confocal microscope analysis showed Fox2 knocking down cells with increased actin polymerization in both MM1S and RPMI8226 cell lines. Currently, RNA seq data following Fox2 knock down in MM cell lines is being evaluated to define the molecular mechanisms of bone marrow microenvironment-mediated Fox2-regualted alternative splicing events in MM. In summary, our results identify Fox2 as a biologically important splicing factor with essential function and potential clinical implications in multiple myeloma. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Dehydroabietic Acid Is a Novel Survivin Inhibitor for Gastric Cancer

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1047
Author(s):  
Won-Jin Kim ◽  
Woong Kim ◽  
Jang-Mi Bae ◽  
Jungsoo Gim ◽  
Seok-Jun Kim
Keyword(s):  
Gastric Cancer ◽  
Anticancer Drugs ◽  
Survivin Expression ◽  
Inhibitory Effect ◽  
Dehydroabietic Acid ◽  
Rna Seq ◽  
Gastric Cancer Cells ◽  
Ags Cells ◽  
Induce Cell Cycle Arrest ◽  
Incidence And Mortality

Gastric cancer is a malignant tumor with a high incidence and mortality rate worldwide. Nevertheless, anticancer drugs that can be used for gastric cancer treatment are limited. Therefore, it is important to develop targeted anticancer drugs for the treatment of gastric cancer. Dehydroabietic acid (DAA) is a diterpene found in tree pine. Previous studies have demonstrated that DAA inhibits gastric cancer cell proliferation by inducing apoptosis. However, we did not know how DAA inhibits the proliferation of gastric cancer cells through apoptosis. In this study, we attempted to identify the genes that induce cell cycle arrest and cell death, as well as those which are altered by DAA treatment. DAA-regulated genes were screened using RNA-Seq and differentially expressed genes (DEGs) analysis in AGS cells. RNA-Seq analysis revealed that the expression of survivin, an apoptosis inhibitor, was significantly reduced by DAA treatment. We also confirmed that DAA decreased survivin expression by RT-PCR and Western blotting analysis. In addition, the ability of DAA to inhibit survivin was compared to that of YM-155, a known survivin inhibitor. DAA was found to have a stronger inhibitory effect in comparison with YM-155. DAA also caused an increase in cleaved caspase-3, an apoptosis-activating protein. In conclusion, DAA is a potential anticancer agent for gastric cancer that inhibits survivin expression.

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