GNA14 and GNAQ somatic mutations cause spinal and intracranial extra-axial cavernous hemangiomas.

Extra-axial cavernous hemangiomas (ECHs) are complex vascular lesions mainly found in the spine and cavernous sinus. Their removal poses significant risk due to their vascularity and diffuse nature, and their genetic underpinnings remain incompletely understood. Our approach involved genetic analyses on 31 tissue samples of ECHs employing whole-exome sequencing and targeted deep sequencing. We explored downstream signaling pathways, gene expression changes, and resultant phenotypic shifts induced by these mutations, both in vitro and in vivo. In our cohort, 77.4% of samples had somatic missense variants in GNA14, GNAQ, or GJA4. Transcriptomic analysis highlighted significant pathway upregulation, with the GNAQ c.626A>G (p.Gln209Arg) mutation elevating PI3K-AKT-mTOR and angiogenesis-related pathways, while GNA14 c.614A>T (p.Gln205Leu) mutation led to MAPK and angiogenesis-related pathway upregulation. Using a mouse xenograft model, we observed enlarged vessels from these mutations. Additionally, we initiated rapamycin treatment in a 14-year-old individual harboring the GNAQ c.626A>G (p.Gln209Arg) variant, resulting in gradual regression of cutaneous cavernous hemangiomas and improved motor strength, with minimal side effects. Understanding these mutations and their pathways provides a foundation for developing therapies for ECHs resistant to current therapies. Indeed, the administration of rapamycin in an individual within this study highlights the promise of targeted treatments in treating these complex lesions.

GNA14 stimulation of KLF7 promotes malignant growth of endometrial cancer through upregulation of HAS2.

BACKGROUND: Endometrial cancer (UCEC) is one of the most common gynecological malignancies. We previously found that overexpression of G protein α subunit 14 (GNA14) promoted UCEC growth. Krüppel-like factor 7 (KLF7) acts as an oncogene in various cancer types, whereas the connection between GNA14 and KLF7 in UCEC is unclear. We herein explored the involvement of GNA14/KLF7 in UCEC development. METHODS: Clinical relevance of GNA14, KLF7 and HAS2 in UCEC was analyzed from TCGA and by immunohistochemical staining. Knockdown and overexpression of indicated genes were conducted by transfecting the cells with siRNAs and lentivirus, respectively. mRNA and protein expression was detected by qRT-PCR and Western blot. CCK8, colony formation, cell cycle, apoptosis, transwell and wound healing were performed to check cell biology function in vitro. Tumor growth in nude mice was conducted to check in vivo function. RNA sequencing was used to determine dys-regulated genes. RESULTS: We demonstrated that GNA14 stimulated the expression of KLF7 in UCEC cells. There was a positive correlation between GNA14 and KLF7 in normal and UCEC tissues. In vitro, KLF7 promoted cell proliferation, colony formation, cell cycle progression, and migration of UCEC cells. Apoptosis was inhibited by KLF7. Xenografted tumorigenesis of UCEC cells was suppressed by KLF7 knockdown. Furthermore, RNA sequencing results showed that KLF7 regulated the expression of a large amount of genes, among which hyaluronan synthase 2 (HAS2) was downregulated in KLF7 knockdown cells. Based on TCGA database and immunoblotting assays, KLF7 positively regulated HAS2 in UCEC cells and tissues. Lastly, knockdown of HAS2 reversed the oncogenic role of KLF7 on UCEC cell proliferation, migration, and xenografted tumor development. CONCLUSION: Taken together, we reveal that GNA14/KLF7/HAS2 signaling cascade exerts tumor promoting function during UCEC development.

G Protein α Subunit 14 Mediates Fibroblast Growth Factor 2-Induced Cellular Responses in Human Endothelial Cells.

During pregnancy, a tremendous increase in fetoplacental angiogenesis is associated with elevated blood flow. Aberrant fetoplacental vascular function may lead to pregnancy complications including pre-eclampsia. Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGFA) are crucial regulators of fetoplacental endothelial function. G protein α subunit 14 (GNA14), a member of Gαq/11 subfamily is involved in mediating hypertensive diseases and tumor vascularization. However, little is known about roles of GNA14 in mediating the FGF2- and VEGFA-induced fetoplacental endothelial function. Using human umbilical vein endothelial cells (HUVECs) cultured under physiological chronic low oxygen (3% O2 ) as a cell model, we show that transfecting cells with adenovirus carrying GNA14 complementary DNA (cDNA; Ad-GNA14) increases (p < 0.05) protein expression of GNA14. GNA14 overexpression blocks (p < 0.05) FGF2-stimulated endothelial migration, whereas it enhances (p < 0.05) endothelial monolayer integrity (maximum increase of ~35% over the control at 24 hr) in response to FGF2. In contrast, GNA14 overexpression does not significantly alter VEGFA-stimulated cell migration, VEGFA-weakened cell monolayer integrity, and intracellular Ca++ mobilization in response to adenosine triphosphate (ATP), FGF2, and VEGFA. GNA14 overexpression does not alter either FGF2- or VEGFA-induced phosphorylation of ERK1/2. However, GNA14 overexpression time-dependently elevates (p < 0.05) phosphorylation of phospholipase C-ß3 (PLCß3) at S1105 in response to FGF2, but not VEGFA. These data suggest that GNA14 distinctively mediates fetoplacental endothelial cell migration and permeability in response to FGF2 and VEGFA, possibly in part by altering activation of PLCß3 under physiological chronic low oxygen.

Subcellular distribution patterns and elevated expression of GNA11 and GNA14 proteins in the lungs of humans with pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH), a progressive and devastating disease, is characterized by abnormal proliferation of pulmonary artery endothelial and smooth muscle cells. GTP-binding protein subunits, GNA11 and GNA14, transmembrane and intracellular signaling molecules, participate in the regulating endothelial function and vascular development. We followed the expression of GNA11 and GNA14 in human lungs in control and PAH patients using immunohistochemical and Western blot analyses. Both GNA11 and GNA14 were expressed in lung tissue, primarily in artery endothelial and smooth muscle cells. Expression was more pronounced in PAH lung tissues compared with controls. Using immunocytochemistry and laser scanning confocal microscopy, the subcellular distribution of GNA11 and GNA14 in human pulmonary arterial endothelial (HPAECs) and smooth muscle (HPASMCs) cells in culture was investigated. GNA11 was predominantly localized in the cytoplasm and nucleus of HPASMCs, but it was only found in the cytoplasm of HPAECs. On the other hand, GNA14 immunolocalized to the nucleus and cytoplasm of both HPAECs and HPASMCs. Based on bioinformatic analyses, nuclear localization signal and transmembrane topology confirm the different subcellular distributions of GNA11 and GNA14. The data suggest that GNA11 and GNA14 are related to PAH pathogenesis, and help further functional studies of these proteins in this severe disease.

Tumor-Promoting Role of GNA14 in Colon Cancer Development.

Recent studies have shown that mutations in members of the G-protein α family contribute to the onset and progression of cancer. However, the role of GNA14 in CRC remains unknown. In this study, we examined the effect of GNA14 on CRC through genetic approaches in vitro and in vivo. We found that GNA14 knockdown by small interfering RNA (siRNA) inhibited the proliferation of CRC cells SW403 and HT29. Gna14 knockout mice developed normally without obvious abnormalities. However, the number of polyps in the small intestine was significantly reduced in Gna14 knockout mice compared to control mice after mating with ApcMin mice, a representative CRC mouse model. In particular, deletion of the Gna14 inhibited polyp growth, especially in the distal end of the small intestine. Histological examination showed that Gna14 knockout mice suppressed malignant tumor progression due to decreased proliferation and increased apoptosis in polyps compared to controls. In addition, GNA14 knockdown in CRC cells resulted in downregulation of ERK phosphorylation and ß-catenin and ß-catenin phosphorylation at S675. Similarly, ERK phosphorylation and phospho-ß-catenin phosphorylation at S675 were decreased in polyps of Gna14 knockout mice. Collectively, these analyses show that GNA14 may accelerate CRC cell proliferation and malignant tumor progression through ERK and ß-catenin pathways.

Hypermethylation of GNA14 and its tumor-suppressive role in hepatitis B virus-related hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide, and its specific mechanism has not been fully elucidated. Inactivation of tumor suppressors may contribute to the occurrence, progression, and recurrence of HCC. DNA methylation is a crucial mechanism involved in regulating the occurrence of HCC. Herein, we aimed to identify the key methylation-related tumor suppressors as well as potential biomarkers and therapeutic targets in HCC. Methods: Combined analysis of TCGA and GEO databases was performed to obtain potential methylation-related tumor suppressors in HCC. Methyl-target sequencing was performed to analyze the methylation level of the GNA14 promoter. The diagnostic value of GNA14 as a predictor of HCC was evaluated in HCC tumor samples and compared with normal tissues. The functional role of GNA14 and its upstream and downstream regulatory factors were investigated by gain-of-function and loss-of-function assays in vitro. Subcutaneous tumorigenesis, lung colonization, and orthotopic liver tumor model were performed to analyze the role of GNA14 in vivo.Results: The expression of GNA14 was found to be downregulated in HCC and it was negatively correlated with hepatitis B virus (HBV) infection, vascular invasion, and prognosis of HCC. DNA methylation was demonstrated to be responsible for the altered expression of GNA14 and was regulated by HBV-encoded X protein (HBx). GNA14 regulated the RB pathway by promoting Notch1 cleavage to inhibit tumor proliferation, and might inhibit tumor metastasis by inhibiting the expression of JMJD6. Conclusion: GNA14 could be regulated by HBx by modulating the methylation status of its promoter. We identified GNA14 as a potential biomarker and therapeutic target for HCC.

Downregulation of GNA14 in hepatocellular carcinoma indicates an unfavorable prognosis.

Guanine nucleotide-binding protein subunit α14 (GNA14) knockdown was demonstrated to inhibit the proliferation of endometrial carcinoma cells in a recent study; however, its role in hepatocellular carcinoma (HCC) is unknown. In the present study, the clinical significance of GNA14 in HCC was assessed using a dataset of patients with HCC from The Cancer Genome Atlas database. The Integrative Molecular Database of Hepatocellular Carcinoma and Oncomine databases were also used to identify the expression levels of GNA14 in HCC tissues. The association between GNA14 expression levels and clinicopathological features was assessed using the Wilcoxon signed-rank test and logistic regression analysis. Kaplan-Meier curves and Cox regression analysis were applied to evaluate the independent risk factors for clinical outcomes. The present study determined GNA14 DNA methylation levels and tumor-infiltrating immune cells, as well as used Gene Set Enrichment Analysis (GSEA) in HCC. GNA14 mRNA expression levels were lower in HCC compared with normal tissues. Downregulation of GNA14 in HCC was significantly associated with tumor grade, clinical stage and T stage. Furthermore, low expression of GNA14 was an independent predictor for survival outcomes. GNA14 expression levels were partially correlated with the infiltration of B cells and macrophages. Additionally, GSEA analysis revealed that the expression levels of GNA14 were associated with multiple signaling pathways, such as translation, DNA replication, and homologous recombination. In conclusion, low GNA14 expression may be a novel biomarker for diagnosis and prognosis prediction for patients with HCC.

Retinoid X receptor modulates olfactory attraction through Gα signaling in the migratory locusts.

Animals communicate with each other in aggregating for survival and adaptation. Solitary locusts show an olfactory transition from repulsion to attraction in aggregation. However, the molecular mechanism underlying this transition is less well known. In this study, we explored differentially expressed transcripts (DETs) during locust aggregation and identified that a functional class of general metabolism encompassed the largest number of DETs among all analyzed gene classes. Within this functional class of general metabolism, oxidoreductase mediates synthesis of retinoic acid (RA) from vitamin A and other metabolites derived from carbohydrates. The expression levels of retinaldehyde hydroxylase 1 (raldh1) and retinoid X receptor (rxr), which are two crucial genes for RA synthesis and signaling, were upregulated during 4 h of crowding. Knockdown of raldh1 and rxr by RNA interference (RNAi) in the brains resulted in the loss of olfactory attraction. Moreover, inhibition of RXR by RNAi resulted in downregulated expression of Gna14, a member of the Gα subfamily that transduces signals in G protein-coupled receptor (GPCR) pathways. Abrogating RXR signaling and Gna14 by RNAi knockdown inhibited the function of dopamine receptor 1 (DopR1) and octopamine receptor α1 (OctαR1) in modulating olfactory attraction. RXR signaling is essential for DopR1 and OctαR1 to mediate olfactory attraction. This study showed that RXR signaling mediates attraction by Gα signaling and confirmed a novel link between nuclear receptor RXR and the membrane receptor GPCRs in modulating olfactory attraction.

GNA11 joins GNAQ and GNA14 as a recurrently mutated gene in anastomosing hemangioma.

Anastomosing hemangioma (AH) is a distinct benign vascular tumor that may be histologically confused with an angiosarcoma. Recently, recurrent GNAQ and GNA14 mutations were identified in AH. GNA11, another paralogue of GNAQ and the one that shows the highest degree of homology to GNAQ, has not yet been found to be mutated in AH. In this study, we investigated the clinicopathological and molecular features of 26 AHs. By Sanger sequencing and MassARRAY analysis, mutually exclusive mutations in exon 5 of GNAQ, GNA11, and GNA14 were identified in 10, 5, and 5 tumors, respectively, of the 22 investigated tumors, with an overall mutation rate of 91%. No notable differences in the clinicopathological features were observed between GNAQ-, GNA11-, or GNA14-mutated tumors. Our results implicated GNA11 mutations, as well as previously known mutations of its paralogues GNAQ and GNA14, as essential drivers in the pathogenesis of AH.

Genetic investigation of childhood vascular tumor biology reveals pathways for therapeutic intervention.

Vascular tumors are neoplasms of endothelial cells, a significant number of which present in childhood. Recent studies have examined the mutational landscape of many subtypes of vascular tumors, identifying mutations primarily within the Ras-mitogen-activated protein kinase (MAPK) pathway and providing a unique opportunity to consider targeted therapeutics. This review will summarize the current understanding of childhood vascular tumor pathobiology.

GNA14 silencing suppresses the proliferation of endometrial carcinoma cells through inducing apoptosis and G2/M cell cycle arrest.

Endometrial carcinoma is the most common gynecological malignancy. The pathological factors triggering this disease are largely unknown. Although the role of guanine nucleotide-binding protein subunit α (GNA) 11 (GNA11) in melanoma has been described, the involvement of GNA14 in endometrial carcinoma remains to be determined. Here, we found that GNA14 expression was increased in endometrial carcinoma tissues compared with simple hyperplasia tissues. Based on lentivirus-mediated knockdown assay, we showed that GNA14 silencing significantly suppressed the proliferation of both HEC-1-A and Ishikawa cells. The caspase 3/caspase 7 activity and apoptosis were enhanced by GNA14 knockdown. GNA14 depletion led to cell cycle arrest at the G2/M phase. In addition, Apoptosis Array analysis revealed that caspase-3 and Fas were up-regulated by GNA14 knockdown. Our study suggests that GNA14 silencing blunts endometrial carcinoma cell proliferation. Targetting GNA14 may bring help for the patients of endometrial carcinoma.