Long non-coding RNAs (lncRNAs) are essential factors that regulate tumor development and metastasis via diverse molecular mechanisms in a broad type of cancers. However, the pathological roles of ...lncRNAs in gallbladder carcinoma (GBC) remain largely unknown. Here we discovered a novel lncRNA termed lncRNA Highly expressed in GBC (lncRNA-HGBC) which was upregulated in GBC tissue and aimed to investigate its role and regulatory mechanism in the development and progression of GBC.
The expression level of lncRNA-HGBC in GBC tissue and different cell lines was determined by quantitative real-time PCR. The full length of lncRNA-HGBC was obtained by 5' and 3' rapid amplification of the cDNA ends (RACE). Cellular localization of lncRNA-HGBC was detected by fluorescence in situ hybridization (FISH) assays and subcellular fractionation assay. In vitro and in vivo assays were preformed to explore the biological effects of lncRNA-HGBC in GBC cells. RNA pull-down assay, mass spectrometry, and RNA immunoprecipitation (RIP) assay were used to identify lncRNA-HGBC-interacting proteins. Dual luciferase reporter assays, AGO2-RIP, and MS2-RIP assays were performed to verify the interaction between lncRNA-HGBC and miR-502-3p.
We found that lncRNA-HGBC was upregulated in GBC and its upregulation could predict poor survival. Overexpression or knockdown of lncRNA-HGBC in GBC cell lines resulted in increased or decreased, respectively, cell proliferation and invasion in vitro and in xenografted tumors. LncRNA-HGBC specifically bound to RNA binding protein Hu Antigen R (HuR) that in turn stabilized lncRNA-HGBC. LncRNA-HGBC functioned as a competitive endogenous RNA to bind to miR-502-3p that inhibits target gene SET. Overexpression, knockdown or mutation of lncRNA-HGBC altered the inhibitory effects of miR-502-3p on SET expression and downstream activation of AKT. Clinically, lncRNA-HGBC expression was negatively correlated with miR-502-3p, but positively correlated with SET and HuR in GBC tissue.
Our study demonstrates that lncRNA-HGBC promotes GBC metastasis via activation of the miR-502-3p-SET-AKT cascade, pointing to lncRNA-HGBC as a new prognostic predictor and a therapeutic target.
Baicalein, a widely used Chinese herbal medicine, has multiple pharmacological activities. However, the precise mechanisms of the anti-proliferation and anti-metastatic effects of baicalein on ...gallbladder cancer (GBC) remain poorly understood. Therefore, the aim of this study was to assess the anti-proliferation and anti-metastatic effects of baicalein and the related mechanism(s) on GBC. In the present study, we found that treatment with baicalein induced a significant inhibitory effect on proliferation and promoted apoptosis in GBC-SD and SGC996 cells, two widely used gallbladder cancer cell lines. Additionally, treatment with baicalein inhibited the metastasis of GBC cells. Moreover, we demonstrated for the first time that baicalein inhibited GBC cell growth and metastasis via down-regulation of the expression level of Zinc finger protein X-linked (ZFX). In conclusion, our studies suggest that baicalein may be a potential phytochemical flavonoid for therapeutics of GBC and ZFX may serve as a molecular marker or predictive target for GBC.
The lysine succinylation (Ksucc) is involved in many core energy metabolism pathways and affects the metabolic process in mitochondria, making this modification highly valuable for studying diseases ...related to mitochondrial disorders. In this paper, we used liquid chromatography with tandem mass spectrometry (LC‐MS/MS) to perform the first global profiling of succinylation in human lungs under normal physiological conditions. Using an MS‐based platform, we identified 1485 Ksucc sites in 568 proteins. We then compared these sites with those previously identified in human succinylome studies to investigate specific succinylated proteins and identify their possible functions in the lung and to explore the substrate preferences of succinylation modifiers in different cell lines and at different subcellular localizations. Our work expands the succinylation database and supplementary materials on the human succinylome and will thus help in further study of the function of Ksucc and regulation under related physiological and pathological conditions.
Direct myocardial and vascular injuries due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-driven inflammation is the leading cause of acute cardiac injury associated with ...coronavirus disease 2019 (COVID-19). However, in-depth knowledge of the injury characteristics of the heart affected by inflammation is lacking. In this study, using a quantitative spatial proteomics strategy that combines comparative anatomy, laser-capture microdissection, and histological examination, we establish a region-resolved proteome map of the myocardia and microvessels with obvious inflammatory cells from hearts of patients with COVID-19. A series of molecular dysfunctions of myocardia and microvessels is observed in different cardiac regions. The myocardia and microvessels of the left atrial are the most susceptible to virus infection and inflammatory storm, suggesting more attention should be paid to the lesion and treatment of these two parts. These results can guide in improving clinical treatments for cardiovascular diseases associated with COVID-19.
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•Spatial proteome maps of COVID-19 myocardia and microvessels are established•SARS-CoV-2-driven inflammation leads to region-resolved dysfunction of the heart•Mechanisms of dysregulated contraction, conduction, and circulation are elaborated•Myocardia and microvessels of the left atrium are affected by inflammation the most
Leng et al. establish a region-resolved proteome map of the inflammatory myocardia and microvessels of COVID-19 hearts. The myocardia and microvessels of the left atrium are the most affected by inflammation storm. These results could provide guidance in improvement of clinical treatments for cardiovascular diseases associated with COVID-19.
Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA (lncRNA), is associated with metastasis and is an independent prognostic factor for lung cancer. Recent studies ...have demonstrated that MALAT1 plays an important role in other malignancies. However, little is known about the role of MALAT1 in gallbladder carcinoma (GBC), which is the most common cancer of the biliary tract and has an extremely poor prognosis. In this study, we focused on the expression, biological functions and mechanism of MALAT1 in GBC and found that MALAT1 was significantly upregulated in GBC tissues compared with corresponding non-cancerous tissues. Knockdown of MALAT1 in GBC cell lines using lentivirus-mediated RNA interference significantly inhibited the proliferation and metastasis of the GBC cells both in vitro and in vivo. Furthermore, ERK/MAPK pathway was found to be inactivated in the GBC cell lines after MALAT1 knockdown. These results indicated that MALAT1 might serve as an oncogenic lncRNA that promotes proliferation and metastasis of GBC and activates the ERK/MAPK pathway
The 2-hydroxyglutarate (2-HG) has been reported to result from mutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) genes and to function as an “oncometabolite.” To evaluate the clinical ...significance of serum 2-HG levels in hematologic malignancies, acute myeloid leukemia (AML) in particular, we analyzed this metabolite in distinct types of human leukemia and lymphoma and established the range of serum 2-HG in appropriate normal control individuals by using gas chromatograph–time-of-flight mass spectrometry. Aberrant serum 2-HG pattern was detected in the multicenter group of AML, with 62 of 367 (17%) patients having 2-HG levels above the cutoff value (2.01, log ₂-transformed from 4.03 μg/mL). IDH1/2 mutations occurred in 27 of 31 (87%) AML cases with very high 2-HG, but were observed only in 9 of 31 (29%) patients with moderately high 2-HG, suggesting other genetic or biochemical events may exist in causing 2-HG elevation. Indeed, glutamine-related metabolites exhibited a pattern in favor of 2-HG synthesis in the high 2-HG group. In AML patients with cytogenetically normal AML (n = 234), high 2-HG represented a negative prognostic factor in both overall survival and event-free survival. Univariate and multivariate analyses confirmed high serum 2-HG as a strong prognostic predictor independent of other clinical and molecular features. We also demonstrated distinct gene-expression/DNA methylation profiles in AML blasts with high 2-HG compared with those with normal ones, supporting a role that 2-HG plays in leukemogenesis.
Mutations in
are considered to be the main drivers of acquired resistance to epidermal growth factor receptor (EGFR) blockade in patients with metastatic colorectal cancer (mCRC). However, the ...potential role of other genes downstream of the EGFR signaling pathway in conferring acquired resistance has not been extensively investigated.
Using circulating tumor DNA (ctDNA) from patients with mCRC and with acquired cetuximab resistance, we developed a targeted amplicon ultra-deep sequencing method to screen for low-abundance somatic mutations in a panel of genes that encode components of the EGFR signaling pathway. Mutations with significantly increased variant frequencies upon disease progression were selected by using quartile analysis. The functional consequences of the identified mutations were validated in cultured cells.
We analyzed 32 patients with acquired cetuximab resistance in a development cohort. Of them, seven (22%) carried five novel
mutations, whereas eight (25%) carried previously reported
mutations. Functional studies showed that novel
mutations (all in exon 19; p.K944N, p.F930S, p.V955G, p.V955I, and p.K966E) promote cell viability in the presence of cetuximab. Only one novel
mutation (p.K944N) was verified in one of the 27 patients with acquired resistance in a validation cohort, simultaneous
and
hotspot mutations were detected in two patients. Among the above 59 acquired resistance patients, those with
or
mutations detected in ctDNA showed a pronounced decrease in progression-free survival than patients with no mutation.
The
mutations may potentially contribute to acquired cetuximab resistance in patients with mCRC.
.
Fitness cost is a common phenomenon in rice blast disease-resistance breeding. MiR396 is a highly conserved microRNA (miRNA) family targeting
Growth Regulating Factor
(
OsGRF
) genes. Mutation at the ...target site of miR396 in certain
OsGRF
gene or blocking miR396 expression leads to increased grain yield. Here we demonstrated that fitness cost can be trade-off in miR396-
OsGRF
s module via balancing growth and immunity against the blast fungus. The accumulation of miR396 isoforms was significantly increased in a susceptible accession, but fluctuated in a resistant accession upon infection of
Magnaporthe oryzae
. The transgenic lines over-expressing different miR396 isoforms were highly susceptible to
M. oryzae
. In contrast, overexpressing target mimicry of miR396 to block its function led to enhanced resistance to
M. oryzae
in addition to improved yield traits. Moreover, transgenic plants overexpressing
OsGRF6
,
OsGRF7
,
OsGRF8
, and
OsGRF9
exhibited enhanced resistance to
M. oryzae
, but showed different alteration of growth. While overexpression of
OsGRF7
led to defects in growth, overexpression of
OsGRF6
,
OsGRF8
, and
OsGRF9
resulted in better or no significant change of yield traits. Collectively, our results indicate that miR396 negatively regulates rice blast disease- resistance via suppressing multiple
OsGRF
s, which in turn differentially control growth and yield. Therefore, miR396-
OsGRFs
could be a potential module to demolish fitness cost in rice blast disease-resistance breeding.
Growing evidence indicates that deregulation of microRNAs (miRNAs) contributes to tumorigenesis. Down‐regulation of miR‐195 has been observed in various types of cancers. However, the biological ...function of miR‐195 is still largely unknown. In this study we aimed to elucidate the pathophysiologic role of miR‐195. Our results showed that miR‐195 expression was significantly reduced in as high as 85.7% of hepatocellular carcinoma (HCC) tissues and in all of the five HCC cell lines examined. Moreover, introduction of miR‐195 dramatically suppressed the ability of HCC and colorectal carcinoma cells to form colonies in vitro and to develop tumors in nude mice. Furthermore, ectopic expression of miR‐195 blocked G1/S transition, whereas inhibition of miR‐195 promoted cell cycle progression. Subsequent investigation characterized multiple G1/S transition‐related molecules, including cyclin D1, CDK6, and E2F3, as direct targets of miR‐195. Silencing of cyclin D1, CDK6, or E2F3 phenocopied the effect of miR‐195, whereas overexpression of these proteins attenuated miR‐195‐induced G1 arrest. In addition, miR‐195 significantly repressed the phosphorylation of Rb as well as the transactivation of downstream target genes of E2F. These results imply that miR‐195 may block the G1/S transition by repressing Rb‐E2F signaling through targeting multiple molecules, including cyclin D1, CDK6, and E2F3. Conclusion: Our data highlight an important role of miR‐195 in cell cycle control and in the molecular etiology of HCC, and implicate the potential application of miR‐195 in cancer therapy. (HEPATOLOGY 2009.)
New Findings
What is the central question of this study?
The central goal of this study was to elucidate the role of magnesium in the regulation of pulmonary vascular reactivity in relationship to ...hypoxic pulmonary hypertension.
What is the main finding and its importance?
We found that magnesium is essential for normal vasoreactivity of the pulmonary artery. Increasing the magnesium concentration attenuates vasoconstriction and improves vasodilatation via release of nitric oxide. Pulmonary hypertension is associated with endothelial dysfunction resulting in the suppression of magnesium modulation of vasodilatation. These results provide evidence that magnesium is important for the modulation of pulmonary vascular function.
Pulmonary hypertension (PH) is characterized by enhanced vasoreactivity and sustained pulmonary vasoconstriction, arising from aberrant Ca2+ homeostasis in pulmonary arterial (PA) smooth muscle cells. In addition to Ca2+, magnesium, the most abundant intracellular divalent cation, also plays crucial roles in many cellular processes that regulate cardiovascular function. Recent findings suggest that magnesium regulates vascular functions by altering the vascular responses to vasodilator and vasoactive agonists and affects endothelial function by modulating endothelium‐dependent vasodilatation in hypertension. Administration of magnesium also decreased pulmonary arterial pressure and improved cardiac output in animal models of PH. However, the role of magnesium in the regulation of pulmonary vascular function related to PH has not been studied. In this study, we examined the effects of magnesium on endothelin‐1 (ET‐1)‐induced vasoconstriction, ACh‐induced vasodilatation and the generation of NO in PAs of normoxic mice and chronic hypoxia (CH)‐treated mice. Our data showed that removal of extracellular magnesium suppressed vasoreactivity of PAs to both ET‐1 and ACh. A high concentration of magnesium (4.8 mm) inhibited ET‐1‐induced vasoconstriction in endothelium‐intact or endothelium‐disrupted PAs of normoxic and CH‐treated mice, and enhanced the ACh‐induced production of NO in PAs of normoxic mice. Moreover, magnesium enhanced ACh‐induced vasodilatation in PAs of normoxic mice, and the enhancement was completely abolished after exposure to CH. Hence, in this study we demonstrated that increasing the magnesium concentration can attenuate the ET‐1‐induced contractile response and improve vasodilatation via release of NO from the endothelium. We also demonstrated that chronic exposure to hypoxia can cause endothelial dysfunction resulting in suppression of the magnesium‐dependent modulation of vasodilatation.
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