The Role of Bitter Taste Receptors in Cancer: A Systematic Review

Background: Since it is known that bitter taste receptors (TAS2Rs) are expressed and functionally active in various extra-oral cells, their genetic variability and functional response initiated by their activation have become of broader interest, including in the context of cancer. Methods: A systematic research was performed in PubMed and Google Scholar to identify relevant publications concerning the role of TAS2Rs in cancer. Results: While the findings on variations of TAS2R genotypes and phenotypes and their association to the risk of developing cancer are still inconclusive, gene expression analyses revealed that TAS2Rs are expressed and some of them are predominately downregulated in cancerous compared to non-cancerous cell lines and tissue samples. Additionally, receptor-specific, agonist-mediated activation induced various anti-cancer effects, such as decreased cell proliferation, migration, and invasion, as well as increased apoptosis. Furthermore, the overexpression of TAS2Rs resulted in a decreased tumour incidence in an in vivo study and TAS2R activation could even enhance the therapeutic effect of chemotherapeutics in vitro. Finally, higher expression levels of TAS2Rs in primary cancerous cells and tissues were associated with an improved prognosis in humans. Conclusion: Since current evidence demonstrates a functional role of TAS2Rs in carcinogenesis, further studies should exploit their potential as (co-)targets of chemotherapeutics.

Download Full-text

Bitter Taste Receptors as Regulators of Abdominal Muscles Contraction

Physiological Research ◽

10.33549/physiolres.934156 ◽

2019 ◽

pp. 991-995

Author(s):

P. Zagorchev ◽

G.V. Petkov ◽

H.S. Gagov

Keyword(s):

Skeletal Muscles ◽

Bitter Taste ◽

Specific Inhibitor ◽

Electrical Field Stimulation ◽

Inhibitory Effect ◽

Abdominal Muscles ◽

Taste Receptors ◽

Bitter Taste Receptors

Bitter taste receptors (TAS2R) are expressed in many non-sensor tissues including skeletal muscles but their function remains unexplored. The aim of this study is to investigate the role of TAS2R in rat abdominal skeletal muscles contractions using denatonium, a TAS2R agonist. Low concentration of denatonium (0.01 mmol/l) caused a significant decrease of amplitudes of the electrical field stimulation (EFS)-induced contractions in abdominal skeletal muscles preparations in vitro. This inhibitory effect was significantly reduced when the preparations were pre-incubated with gentamicin (0.02 mmol/l) used as a non-specific inhibitor of IP3 formation or with BaCl(2) (0.03 mmol/l) applied to block the inward-rectifier potassium current. All experiments were performed in the presence of pipecuronium in order to block the nerve stimulation of the contractions. The data obtained suggest that denatonium decreases the force of rat abdominal muscles contractions mainly via activation of TAS2R, phosphatidylinositol 4,5-biphosphate and its downstream signal metabolites.

Download Full-text

Splicing factor SRSF1 promotes breast cancer progression via oncogenic splice switching of PTPMT1

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-01978-8 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Jun-Xian Du ◽

Yi-Hong Luo ◽

Si-Jia Zhang ◽

Biao Wang ◽

Cong Chen ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Progression ◽

High Risk Group ◽

Clinical Samples ◽

Binding Motif ◽

Ki 67 ◽

Tissue Samples

Abstract Background Intensive evidence has highlighted the effect of aberrant alternative splicing (AS) events on cancer progression when triggered by dysregulation of the SR protein family. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods We conducted a comprehensive analysis of the expression and clinical correlation of SRSF1 in BRCA based on the TCGA dataset, Metabric database and clinical tissue samples. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and their binding motifs were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. PTPMT1 exon 3 (E3) AS was identified to partially mediate the oncogenic role of SRSF1 by the P-AKT/C-MYC axis. Finally, the expression and clinical significance of these AS events were validated in clinical samples and using the TCGA database. Results SRSF1 expression was consistently upregulated in BRCA samples, positively associated with tumor grade and the Ki-67 index, and correlated with poor prognosis in a hormone receptor-positive (HR+) cohort, which facilitated proliferation, cell migration and inhibited apoptosis in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of splice switching of PTPMT1. Furthermore, PTPMT1 splice switching was regulated by SRSF1 by binding directly to its motif in E3 which partially mediated the oncogenic role of SRSF1 by the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients and using the TCGA database. The high-risk group, identified by AS of PTPMT1 and expression of SRSF1, possessed poorer prognosis in the stage I/II TCGA BRCA cohort. Conclusions SRSF1 exerts oncogenic roles in BRCA partially by regulating the AS of PTPMT1, which could be a therapeutic target candidate in BRCA and a prognostic factor in HR+ BRCA patient.

Download Full-text

Bitter Taste Receptors Expression in Human Granulosa and Cumulus Cells: New Perspectives in Female Fertility

Cells ◽

10.3390/cells10113127 ◽

2021 ◽

Vol 10 (11) ◽

pp. 3127

Author(s):

Bianca Semplici ◽

Francesca Paola Luongo ◽

Sofia Passaponti ◽

Claudia Landi ◽

Laura Governini ◽

...

Keyword(s):

Reproductive System ◽

Bitter Taste ◽

Receptor Activation ◽

Female Fertility ◽

Human Reproduction ◽

Receptor Subtype ◽

Taste Receptors ◽

Female Reproductive System ◽

Bitter Taste Receptors

Bitter taste receptors (TAS2RS) expression is not restricted to the oral cavity and the presence of these receptors in the male reproductive system and sperm provides insights into their possible role in human reproduction. To elucidate the potential role of TAS2Rs in the female reproductive system, we investigated the expression and localization of bitter taste receptors and the components of signal transduction cascade involved in the pathway of taste receptors in somatic follicular cells obtained from women undergoing assisted reproductive techniques. We found that TAS2R genes are expressed in both cumulus (CCs) and granulosa (GCs) cells, with TAS2R14 being the most highly expressed bitter receptor subtype. Interestingly, a slight increase in the expression of TAS2R14 and TAS2R43 was shown in both GCs and CCs in young women (p < 0.05), while a negative correlation may be established between the number of oocytes collected at the pickup and the expression of TAS2R43. Regarding α-gustducin and α-transducin, two Gα subunits expressed in the taste buds on the tongue, we provide evidence for their expression in CCs and GCs, with α-gustducin showing two additional isoforms in GCs. Finally, we shed light on the possible downstream transduction pathway initiated by taste receptor activation in the female reproductive system. Our study, showing for the first time the expression of taste receptors in the somatic ovarian follicle cells, significantly extends the current knowledge of the biological role of TAS2Rs for human female fertility.

Download Full-text

circATP2A2 promotes osteosarcoma progression by upregulating MYH9

Open Medicine ◽

10.1515/med-2021-0370 ◽

2021 ◽

Vol 16 (1) ◽

pp. 1749-1761

Author(s):

Xin Cao ◽

Xianfeng Meng ◽

Peng Fu ◽

Lin Wu ◽

Zhen Yang ◽

...

Keyword(s):

Cell Proliferation ◽

Area Under Curve ◽

Prognostic Biomarker ◽

Migration And Invasion ◽

Promising Target ◽

Repressive Effect ◽

Cell Malignancy

Abstract Osteosarcoma (OS) is a highly metastatic primary malignant tumor. CircRNA hsa_circ_0028173 (circATP2A2) has been uncovered to be related to the advancement of OS. However, the biological role of circATP2A2 in OS has not been validated. circATP2A2 and MYH9 were upregulated while miR-335-5p was downregulated in OS. OS patients with high circATP2A2 expression displayed a shorter overall survival and the area under curve of circATP2A2 was 0.77, manifesting that circATP2A2 might be a diagnostic and prognostic biomarker. circATP2A2 silencing repressed OS cell proliferation and glycolysis in vivo and constrained OS cell proliferation, glycolysis, migration, and invasion in vitro. circATP2A2 regulated MYH9 expression through sponging miR-335-5p. MiR-335-5p inhibitor reversed the repressive effect of circATP2A2 knockdown on OS cell malignancy and glycolysis. MYH9 overexpression overturned miR-335-5p upregulation-mediated OS cell malignancy and glycolysis. circATP2A2 accelerated OS cell malignancy and glycolysis through upregulating MYH9 via sponging miR-335-5p, offering a promising target for OS treatment.

Download Full-text

Has-miR-875-5p Inhibits Tumorigenesis by Targeting USF2 via TGF-β Signaling Pathway in Gastric Cancer

10.21203/rs.3.rs-885737/v1 ◽

2021 ◽

Author(s):

Shenshuo Gao ◽

Zhikai Zhang ◽

Xubin Wang ◽

Yan Ma ◽

Chensheng Li ◽

...

Keyword(s):

Gastric Cancer ◽

Signaling Pathway ◽

Research Direction ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Gastric Cancer Cells ◽

New Research

Abstract Background: Gastric cancer (GC) is one of the most common malignancies, and more and more evdiences show that the pathogenesis is regulated by various miRNAs.In this study, we investigated the role of miR-875 in GC. Methods:The expression of miR-875-5p was detected in human GC specimens and cell lines by miRNA RT-PCR. The effect of miR-875-5p on GC proliferation was determined by CCK-8 proliferation assay and EDU assay. Migration and invasion were examined by transwell migration and invasion assay and wound healing assay. The interaction between miR-875-5p and its target gene USF2 was verified by a dual luciferase reporter assay. The effects of miR-875-5p in vivo were studied in xenograft nude mice models.Related proteins were detected by Western blot.Results:The results showed that miR-875-5p inhibited the proliferation, migration and invasion of gastric cancer cells in vitro, and inhibited tumorigenesis in vivo. USF2 proved to be a direct target of miR-875-5p. Knockdown of USF2 partially counteracts the effects of miR-875-5p inhibitors.Overexpression of miR-875-5p can inhibit proliferation, migration, and invasion through the TGF-β signaling pathway by down-regulation of USF2 in GC, providing a new research direction for the diagnosis and targeted therapy of GC.Conclusions: MiR-875-5pcan inhibited the progression of GC by directly targeting USF2 and negatively regulating TGF-β signaling pathway.In the future, miR-875-5p is expected to be used as a potential therapeutic target for GC therapy.

Download Full-text

NUSAP1 Promotes Gastric Cancer Progression Through Regulation of Yap Stability

10.21203/rs.3.rs-33883/v1 ◽

2020 ◽

Author(s):

Hui Guo ◽

Jianping Zou ◽

Ling Zhou ◽

Yan He ◽

Miao Feng ◽

...

Keyword(s):

Gastric Cancer ◽

Cancer Progression ◽

Target Genes ◽

Hippo Pathway ◽

Critical Role ◽

Xenograft Model ◽

Migration And Invasion

Abstract Background:Nucleolar and spindle associated protein (NUSAP1) is involved in tumor initiation, progression and metastasis. However, there are limited studies regarding the role of NUSAP1 in gastric cancer (GC). Methods: The expression profile and clinical significance of NUSAP1 in GC were analysed in online database using GEPIA, Oncomine and KM plotter, which was further confirmed in clinical specimens.The functional role of NUSAP1 were detected utilizing in vitro and in vivo assays. Western blotting, qRT-PCR, the cycloheximide-chase, immunofluorescence staining and Co-immunoprecipitaion (Co-IP) assays were performed to explore the possible molecular mechanism by which NUSAP1 stabilizes YAP protein. Results:In this study, we found that the expression of NUSAP1 was upregulated in GC tissues and correlates closely with progression and prognosis. Additionally, abnormal NUSAP1 expression promoted malignant behaviors of GC cells in vitro and in a xenograft model. Mechanistically, we discovered that NUSAP1 physically interacts with YAP and furthermore stabilizes YAP protein expression, which induces the transcription of Hippo pathway downstream target genes. Furthermore, the effects of NUSAP1 on GC cell growth, migration and invasion were mainly mediated by YAP. Conclusions:Our data demonstrates that the novel NUSAP1-YAP axis exerts an critical role in GC tumorigenesis and progression, and therefore could provide a novel therapeutic target for GC treatment.

Download Full-text

The short third intracellular loop and cytoplasmic tail of bitter taste receptors provide functionally relevant GRK phosphorylation sites in TAS2R14

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.016056 ◽

2020 ◽

pp. jbc.RA120.016056

Author(s):

Donghwa Kim ◽

Maria Castaño ◽

Lauren K Lujan ◽

Jung A. Woo ◽

Stephen B. Liggett

Keyword(s):

Bitter Taste ◽

Taste Receptors ◽

Intracellular Loop ◽

Early Endosomes ◽

Bitter Taste Receptors ◽

Novel Target ◽

Intracellular Loops ◽

G Protein Coupled ◽

Gst Fusion Proteins

For most GPCRs, the third intracellular loops (IL3) and C-terminal tails (CT) are sites for GRK-mediated phosphorylation, leading to b-arrestin binding and agonist-specific desensitization. These regions of the G protein-coupled bitter taste receptors (TAS2Rs) are short compared to the superfamily, and their functional role is unclear. TAS2R14 expressed on human airway smooth muscle (HASM) cells relax the cell, suggesting a novel target for bronchodilators. To assess IL3 and CT in agonist-promoted TAS2R14 desensitization (tachyphylaxis), we generated GST-fusion proteins of both the WT sequence and Ala substituted for Ser/Thr in the IL3 and CT sequences. In vitro, activated GRK2 phosphorylated both WT IL3 and WT CT proteins but not Ala-substituted forms. Next, TAS2R14s with mutations in IL3 (IL-5A), CT (CT-5A) and in both regions (IL/CT-10A) were expressed in HEK-293T cells. IL/CT-10A and CT-5A failed to undergo desensitization of the [Ca2+]i response compared to WT, indicating functional desensitization by GRK-phosphorylation is at residues in the CT. Short-term desensitization of TAS2R14 was blocked by GRK2 knockdown in HASM cells. Receptor:b-arrestin binding was absent with IL/CT-10A and CT-5A, but was also reduced in IL-5A, indicating a role for IL3 phosphorylation in the b-arrestin interaction for this function. Agonist-promoted internalization of IL-5A and CT-5A receptors was impaired and these receptors failed to colocalize with early endosomes. These results show that agonist-promoted functional desensitization of TAS2R14 occurs by GRK phosphorylation of CT residues and b-arrestin binding. However, b-arrestin function in the internalization and trafficking of the receptor requires cooperative GRK phosphorylation of IL3 and CT residues.

Download Full-text

KIF4A Regulates the Progression of Pancreatic Ductal Adenocarcinoma through Proliferation and Invasion

BioMed Research International ◽

10.1155/2021/8249293 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Jing Chen ◽

Cui-Cui Zhao ◽

Fei-Ran Chen ◽

Guo-Wei Feng ◽

Fei Luo ◽

...

Keyword(s):

Pancreatic Cancer ◽

Cell Proliferation ◽

Pancreatic Ductal Adenocarcinoma ◽

Disease Free Survival ◽

High Expression ◽

Ductal Adenocarcinoma ◽

Migration And Invasion

Background. Pancreatic cancer is a malignant tumor of the digestive tract, which is difficult to diagnose and treat due to bad early diagnosis. We aimed to explore the role of kinesin superfamily 4A (KIF4A) in pancreatic ductal adenocarcinoma (PDAC). Methods. We first used the bioinformatic website to screen the data of pancreatic cancer in TCGA, and KIF4A protein was detected among the 86 specimens of patients in our hospital combined with clinic-pathological characteristics and survival analysis. KIF4A loss-expression cell lines were established by RNA interference (RNAi). In addition, we performed in vitro cell assays to detect the changes in cell proliferation, migration, and invasion. The proteins involved in the proliferation and metastasis of cancer cells were also detected by western blot. The above results could be proved in vivo. Further, the correlation between KIF4A and CDC5L was analyzed by TCGA and IHC data. Results. We first found a high expression of KIF4A in pancreatic cancer, suggesting a role of KIF4A in the development of pancreatic cancer. KIF4A was found to be differentially expressed ( P < 0.05 ) among the 86 specimens of patients in our hospital and was significantly associated with PDAC TNM stages and tumor size. High KIF4A expression also significantly worsened overall survival (OS) and disease-free survival rate (DFS) ( P < 0.05 , respectively). In addition, cell proliferation, migration, and invasion were inhibited by the KIF4A-shRNA group compared with the control ( P < 0.05 , respectively). In the end, knockdown of KIF4A could inhibit tumor development and metastasis in vivo. Further, the positive correlation between KIF4A and CDC5L existed, and KIF4A might promote pancreatic cancer proliferation by affecting CDC5L expression. Conclusion. In conclusion, the high expression level of KIF4A in PDAC was closely related to poor clinical and pathological status, lymphatic metastasis, and vascular invasion. KIF4A might be involved in promoting the development of PDAC in vitro and in vivo, which might be a new therapeutic target of PDAC.

Download Full-text

Abstract 237: PRMT1-p53-Slug Axis Regulates Epicardial EMT and Ventricular Development

Circulation Research ◽

10.1161/res.121.suppl_1.237 ◽

2017 ◽

Vol 121 (suppl_1) ◽

Author(s):

Olan Jackson-Weaver ◽

Jian Wu ◽

Yongchao Gou ◽

Yibu Chen ◽

Meng Li ◽

...

Keyword(s):

Blood Vessels ◽

Heart Development ◽

Cultured Cells ◽

Migration And Invasion ◽

P53 Expression ◽

Epicardial Cells ◽

Coronary Blood Vessels

Rationale: Epicardial epithelial-to-mesenchymal trasition (EMT) is a vital process in embryonic heart development. During EMT, epicardial cells acquire migratory and invasive properties, and differentiate into new cell types, including cardiac fibroblasts and coronary smooth muscle cells. Non-histone protein methylation is an emerging modulator of cell signaling. We have recently established a role for protein arginine methyltransferase-1 (PRMT1) in TGF-β-induced EMT in cultured cells. Objective: To determine the role of PRMT1 in epicardial EMT. Methods and Results: We investigated the role of PRMT1 in epicardial EMT in mouse epicardial cells. Embryonic day 9.5 (E9.5) tamoxifen administration of WT1-Cre ERT ;PRMT1 fl/fl ;ROSA-YFP fl/fl mouse embryos was used to delete PRMT1 in the epicardium. Epicardial PRMT1 deletion led to reduced epicardial migration into the myocardium, a thinner compact myocardial layer, and dilated coronary blood vessels at E15.5. Using the epicardial cell line MEC1, we found that PRMT1 siRNA prevented the increase in mesenchymal proteins Slug and Fibronectin and the decrease in epithelial protein E-Cadherin during TGF-β treatment-induced EMT. PRMT1 siRNA also reduced the migration and invasion of MEC1 cells. We further identified that PRMT1 siRNA also increased the expression of p53, a key regulator of the Slug degradation pathway. PRMT1 siRNA increases p53 expression by decreasing p53 degradation, and shifted p53 localization to the cytoplasm. In vitro methylation assays further demonstrated that PRMT1 methylates p53. Knockdown of p53 increased Slug levels and enhanced EMT, establishing p53 as a regulator of epicardial EMT through controlling Slug expression. Furthermore, RNAseq experiments in MEC1 cells demonstrated that 40% (545/1,351) of TGF-β-induced transcriptional changes were prevented by PRMT1 siRNA. Furthermore, when p53 and PRMT1 were simultaneously knocked down, TGF-β induced transcriptional control of 37% (201/545) of these PRMT1-dependent genes was restored. Conclusions: The PRMT1-p53-Slug pathway is necessary for epicardial EMT in cultured MEC1 cells as well as in the epicardium in vivo . Epicardial PRMT1 is required for the development of compact myocardium and coronary blood vessels.

Download Full-text

LINC01006 facilitates cell proliferation, migration and invasion in prostate cancer through targeting miR-34a-5p to up-regulate DAAM1

Cancer Cell International ◽

10.1186/s12935-020-01577-1 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Enhui Ma ◽

Qianqian Wang ◽

Jinhua Li ◽

Xinqi Zhang ◽

Zhenjia Guo ◽

...

Keyword(s):

Prostate Cancer ◽

Prostate Gland ◽

Inhibitory Effect ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Protein Coding ◽

Novel Target

Abstract Background Prostate cancer (PCa) is a kind of malignancy occurring in the prostate gland. Substantial researches have proved the major role of long noncoding RNAs (lncRNAs) in PCa. However, the role of long intergenic non-protein coding RNA 1006 (LINC01006) in PCa has not been investigated yet. Methods RT-qPCR was used to examine the expression levels of LINC01006 and its downstream targets. The function of LINC01006 in PCa was tested by in vitro and in vivo assays. With application of RNA pull down, RNA immunoprecipitation (RIP) and luciferase reporter assays, the interaction among LINC01006, miR-34a-5p and disheveled associated activator of morphogenesis 1 (DAAM1) were verified. Results LINC01006 expression presented high in PCa cell lines. LINC01006 silencing suppressed cell proliferative, migratory, invasive capacities while accelerated apoptotic rate. Besides, LINC01006 knockdown also suppressed tumor growth and metastasis in vivo. Furthermore, miR-34a-5p, a tumor suppressor in PCa, was sponged by LINC01006. Moreover, DAAM1 was targeted by miR-34a-5p and promoted PCa progression. More intriguingly, rescue assays suggested that the inhibitory effect of LINC01006 knockdown on PCa development was offset by DAAM1 overexpression. Conclusions LINC01006 promoted PCa progression by sponging miR-34a-5p to up-regulate DAAM1, providing a novel target for PCa therapy.

Download Full-text