TP63 truncating mutation causes increased cell apoptosis and premature ovarian insufficiency by enhanced transcriptional activation of CLCA2

BACKGROUND

Premature ovarian insufficiency (POI) is a severe disorder leading to female infertility. Genetic mutations are important factors causing POI. TP63-truncating mutation has been reported to cause POI by increasing germ cell apoptosis, however what factors mediate this apoptosis remains unclear.

METHODS

Ninety-three patients with POI were recruited from Beijing Obstetrics and Gynecology Hospital, Capital Medical University. Whole-exome sequencing (WES) was performed for each patient. Sanger sequencing was used to confirm potential causative genetic variants. A minigene assay was performed to determine splicing effects of TP63 variants. A TP63-truncating plasmid was constructed. Real-time quantitative PCR, western blot analyses, dual luciferase reporter assays, immunofluorescence staining, and cell apoptosis assays were used to study the underlying mechanism of a TP63-truncating mutation causing POI.

RESULTS

By WES of 93 sporadic patients with POI, we found a 14-bp deletion covering the splice site in the TP63 gene. A minigene assay demonstrated that the 14-bp deletion variant led to exon 13 skipping during TP63 mRNA splicing, resulting in the generation of a truncated TP63 protein (TP63-mut). Overexpression of TP63-mut accelerated cell apoptosis. Mechanistically, the TP63-mut protein could bind to the promoter region of CLCA2 and activate the transcription of CLCA2 several times compared to that of the TP63 wild-type protein. Silencing CLCA2 using a specific small interfering RNA (siRNA) or inhibiting the Ataxia Telangiectasia Mutated (ATM) pathway using the KU55933 inhibitor attenuated cell apoptosis caused by TP63-mut protein expression.

CONCLUSION

Our findings revealed a crucial role for CLCA2 in mediating apoptosis in POI pathogenesis, and suggested that CLCA2 is a potential therapeutic target for POI.

Succinylation of CTBP1 mediated by KAT2A suppresses its inhibitory activity on the transcription of CDH1 to promote the progression of prostate cancer

CTBP1 has been demonstrated as a co-repressor in the transcriptional regulation of downstream genes and is involved in various cell process. However, the mechanism of CTBP1 in the progression of prostate cancer is still unclear. Here, we aim to investigate how CTBP1 exerts its role in prostate cancer progression, especially how CTBP1 was regulated by the upstream genes. We found that CTBP1 was highly expressed in prostate cancer and promoted the cell viability, migration, invasion and glycolysis of prostate cancer cells. CDH1 was verified to be the target of CTBP1. We determined that CTBP1 could directly bind with SP1 to inhibit the transcription of CDH1. Moreover, succinylation of CTBP1 was found to be up-regulated in prostate cancer cell. Further studies demonstrated that KAT2A promotes the succinylation of CTBP1 and mediates the transcription suppressing activity of it. In addition, the K46 and K280 was confirmed to be the two sites that regulated by KAT2A. In vivo studies further indicated that CTBP1 could promote the growth of prostate cancer, and this effect of CTBP1 could be partially reversed by KAT2A knockdown. Taken together, we found that succinylation of CTBP1 mediated by KAT2A suppresses the inhibitory activity of CTBP1 on the transcription of CDH1, thus act as an oncogene.

Genomic and expressional dynamics of ovarian cancer cell lines in PARPi treatment revealed mechanisms of acquired resistance

BACKGROUND

Patients with epithelial ovarian cancer (EOC) can benefit from poly- (ADP ribose) polymerase inhibitors (PARPi) therapy. However, PARPi resistance has become a challenge in clinical practice, and its mechanism requires further exploration.

METHODS

We established three PARPi-resistant cell strains following olaparib exposure. CCK-8, clonogenic survival, transwell, wound healing, cell cycle, RT-qPCR and western blot assays were performed to explore the functional phenotype of the resistant cells. Whole-exome sequencing and RNA-sequencing were performed to identify the altered genes. Stable knockdown and overexpression were used to investigate the role of EP300, an upstream regulator of E-cadherin and epithelial-mesenchymal transition (EMT), in cell lines. We further validated the finding in clinical ovarian cancer samples by immunohistochemistry.

RESULTS

We combined public datasets to obtain an integrated PARPi sensitivity profile in EOC cells, which indicated that primary PARPi resistance could not be fully explained by mutations in BRCA1/2 or homologous recombination deficiency related genes. Genomic and transcriptome analyses revealed distinct mechanisms between primary and acquired resistance. Long-term PARPi treatment induced accumulation of de novo single nucleotide variants (SNV), and the complete frame-shift deletion of PARP1 was detected in the A2780 resistant strain. Additionally, the depressed histone acetyltransferase of EP300 could cause resistant phenotype through activated EMT process in vitro, and associated with PARPi-resistance in EOC patients.

CONCLUSION

Long-term PARPi treatment led to evolutionary genomic and transcriptional alterations that were associated with acquired resistance, among which depressed EP300 partly contributed to the resistant phenotype.

Hsa-miR-133a-3p, miR-1-3p, GOLPH3 and JUP combination results in a good biomarker to distinguish between prostate cancer and non-prostate cancer patients

The incidence and mortality of Prostate Cancer (PCa) worldwide correlate with age and bad dietary habits. Previously, we investigated the mRNA/miRNA role on PCa development and progression using high fat diet (HFD) fed mice. Here our main goal was to investigate the effect of HFD on the expression of PCa-related miRNAs and their relevance in PCa patients. We identified 6 up- and 18 down-regulated miRNAs in TRAMP-C1 mice prostate tumors under HFD conditions using miRNA microarrays. Three down-regulated miRNAs: mmu-miR-133a-3p, -1a-3p and -29c-3p were validated in TRAMP-C1 mice prostate tumor by stem-loop RT-qPCR. Hsa-miR-133a-3p/1-3p expression levels were significantly decreased in PCa compared to normal tissues while hsa-miR-133a-3p was found to be further decreased in metastatic prostate cancer tumors compared to non-metastatic PCa. We examined the promoter region of hsa-miR-133a-3p/1-3p genes and compared methylation at these loci with mature miRNA expression. We found that hsa-miR-1-2/miR-133a-1 cluster promoter hypermethylation decreased hsa-miR-133a-3p/1-3p expression in PCa. GOLPH3 and JUP, two hsa-miR-133a-3p and miR-1-3p predicted target genes, were up-regulated in PCa. ROC analysis showed that the combination of hsa-miR-133a-3p, miR-1-3p, GOLPH3 and JUP is a promising panel biomarker to distinguish between PCa and normal adjacent tissue (NAT). These results link PCa aggressiveness to the attenuation of hsa-miR-133a-3p and miR-1-3p expression by promoter hypermethylation. Hsa-miR-133a-3p and miR-1-3p down-regulation may enhance PCa aggressiveness in part by targeting GOLPH3 and JUP.

CLCA2 overexpression suppresses epithelial-to-mesenchymal transition in cervical cancer cells through inactivation of ERK/JNK/p38-MAPK signaling pathways

Cervical cancer is an important malignant tumor threatening the physical and mental health of women in the world. As a new calcium activated chloride channel protein, calcium activated chloride channel (CLCA2) plays an important role in tumorigenesis and development. But its role and exact regulatory mechanism in cervical cancer are still unclear. In our study, we found CLCA2 was significantly decreased in cervical cancer cells, and overexpression of CLCA2 inhibited the proliferation, migration and invasion, and promotes apoptosis of cervical cancer cells, and CLCA2 inhibited EMT (Epithelial-mesenchymal transition) through an p38 / JNK / ERK pathway. The results in vivo were consistent with those in vitro. In conclusion, overexpression of CLCA2 inhibited the progression of cervical cancer in vivo and in vitro. This may provide a theoretical basis for CLCA2 as a new indicator of clinical diagnosis and prognosis of cervical cancer or as a potential target of drug therapy.

Lipid metabolism-related lncRNA SLC25A21-AS1 promotes the progression of oesophageal squamous cell carcinoma by regulating the NPM1/c-Myc axis and SLC25A21 expression

BACKGROUND

Obesity alters metabolic microenvironment and is thus associated with several tumours. The aim of the present study was to investigate the role, molecular mechanism of action, and potential clinical value of lipid metabolism-related long non-coding RNA (lncRNA) SLC25A21-AS1 in oesophageal squamous cell carcinoma (ESCC).

METHODS

A high-fat diets (HFDs)-induced obesity nude mouse model was established, and targeted metabolomics analysis was used to identify critical medium-long chain fatty acids influencing the growth of ESCC cells. Transcriptomic analysis of public dataset GSE53625 confirmed that lncRNA SLC25A21-AS1 was a lipid metabolism-related lncRNA. The biological function of lncRNA SLC25A21-AS1 in ESCC was investigated both in vivo and in vitro. Chromatin immunoprecipitation(ChIP)assay, RNA-pull down, mass spectrometry, co-IP, and RNA IP(RIP) were performed to explore the molecular mechanism. Finally, an ESCC cDNA microarray was used to determine the clinical prognostic value of SLC25A21-AS1 by RT-qPCR.

RESULTS

Palmitic acid (PA) is an important fatty acid component of HFD and had an inhibitory effect on ESCC cell lines. LncRNA SLC25A21-AS1 expression was downregulated by PA and associated with the proliferation and migration of ESCC cells in vitro and in vivo. Mechanistically, SLC25A21-AS1 interacted with nucleophosmin-1 (NPM1) protein to promote the downstream gene transcription of the c-Myc in the nucleus. In the cytoplasm, SLC25A21-AS1 maintained the stability of SLC25A21 mRNA and reduced the intracellular NAD+ /NADH ratio by influencing tryptophan catabolism. Finally, we demonstrated that high expression of SLC25A21-AS1 promoted resistance to cisplatin-induced apoptosis and was correlated with poor tumour grade and overall survival.

CONCLUSIONS

HFD/PA has an inhibitory effect on ESCC cells and SLC25A21-AS1 expression. SLC25A21-AS1 promotes the proliferation and migration of ESCC cells by regulating the NPM1/c-Myc axis and SLC25A21 expression. In addition, lncRNA SLC25A21-AS1 may serve as a favourable prognostic biomarker and a potential therapeutic target for ESCC.

Circular RNA (circ)_0129047 upregulates bone morphogenetic protein receptor type 2 expression to inhibit lung adenocarcinoma progression by sponging microRNA (miR)-1206

Circular RNAs (circRNAs) play significant roles in the tumorigenesis and progression of various cancers, including lung adenocarcinoma (LAC). However, their underlying biological functions in LAC remain unclear. Here, we investigated the tumor suppressor role of the newly identified circRNA, circ_0129047, in LAC tumorigenesis and progression. The expression levels of circ_0129047, microRNA (miR)-1206, and bone morphogenetic protein receptor type 2 (BMPR2) mRNA in LAC cells and tissues were monitored using reverse transcription-quantitative polymerase chain reaction. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were used to confirm the targeting relationships among circ_0129047, miR-1206, and BMPR2 mRNA. Functional experiments for A549 and PC9 cells were performed using cell counting kit-8, bromodeoxyuridine enzyme-linked immunosorbent, caspase-3 activity, cell adhesion, wound healing, and transwell assays. Circ_0129047 expression levels were reduced in LAC cells and tissues. Mechanistically, we discovered that circ_0129047 could sponge miR-1206, and miR-1206 could directly target BMPR2. In addition, circ_0129047 or BMPR2 knockdown facilitated the viability, proliferation, adhesion, migration, and invasion, while inhibiting the apoptosis of LAC cells. Furthermore, the inhibitory effects of circ_0129047 or BMPR2 overexpression on the malignant phenotype of LAC cells could be reversed by the overexpression of miR-1206. In conclusion, circ _0129047 was found to play a tumor suppressive role in LAC progression; it upregulated BMPR2 expression to inhibit LAC progression by sponging miR-1206.

Abbreviations: non-small cell lung cancer (NSCLC); small cell lung cancer (SCLC); lung adenocarcinoma (LAC); Circular RNA (circRNA); MicroRNA (miRNA); bone morphogenetic protein (BMP); squamous cell lung cancer (SCC); RNA immunoprecipitation (RIP)

Dysregulation of E-cadherin in pulmonary cell damage related with COPD contributes to emphysema

Air pollution, especially at chronic exposure to high concentrations, is a respiratory risk factor for the development of chronic obstructive pulmonary disease (COPD). E-cadherin, a cell–cell adhesion protein, is involved in the integrity of the alveolar epithelium. Causes of E-cadherin decreases in emphysematous areas with pulmonary cell damage related to COPD are not well understood. We aimed to determine the molecules causing the decrease of E-cadherin and interactions between these molecules. In emphysematous and non-emphysematous areas of lungs from COPD patients (n = 35), levels of E-cadherin, HDACs, Snail, Zeb1, active-β-catenin, p120ctn, and Kaiso were determined by using Western Blot. The interactions of HDAC1, HDAC2, and p120ctn with transcription co-activators and Kaiso were examined by co-immunoprecipitation experiments. The methylation status of the CDH1 promoter was investigated. E-cadherin, Zeb1, Kaiso, and active-β-catenin were decreased in emphysema, while HDAC1, HDAC2, and p120ctn2 were increased. Snail, Zeb1, Twist, active-β-catenin, Kaiso, and p120ctn co-precipitated with HDAC1 and HDAC2. E-cadherin, Kaiso, and active-β-catenin co-precipitated with p120ctn. HDAC1–Snail and HDAC2–Kaiso interactions were increased in emphysema, but p120ctn-E-cadherin interaction was decreased. The results show that HDAC1–Snail and HDAC2–Kaiso interactions are capable of decreasing the E-cadherin in emphysema. The decreased interaction of p120ctn/E-cadherin leads to E-cadherin destruction. The decreased E-cadherin and its induced degradation in pneumocytes cause impaired repair and disintegrity of the epithelium. Approaches to suppress HDAC1–Snail and HDAC2–Kaiso interactions may help the protection of alveolar epithelial integrity by increasing the E-cadherin stability in pneumocytes.

Comprehensive Analyses of Glucose Metabolism in Glioma Reveal the Glioma-Promoting Effect of GALM

Glioma is the most common tumor with the worst prognosis in the central nervous system. Current studies showed that glucose metabolism could affect the malignant progression of tumors. However, the study on the dysregulation of glucose metabolism in glioma is still limited. Herein, we firstly screened 48 differentially expressed glucose metabolism-related genes (DE-GMGs) by comparing glioblastomas to low-grade gliomas. Then a glucose metabolism-related gene (GMG)-based model (PC, lactate dehydrogenase A (LDHA), glucuronidase beta (GUSB), galactosidase beta 1 (GLB1), galactose mutarotase (GALM), or fructose-bisphosphatase 1 (FBP1)) was constructed by a protein-protein interaction (PPI) network and Lasso regression. Thereinto, the high-risk group encountered a worse prognosis than the low-risk group, and the M2 macrophage was positively relevant to the risk score. Various classical tumor-related functions were enriched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Since protein GALM was rarely studied in glioma, we detected high expression of GALM by western blot and immunohistochemistry in glioma tissues. And experiments in vitro showed that GALM could promote the epithelial-to-mesenchymal transition (EMT) process of glioma cells and could be regulated by TNFAIP3 in glioma cells. Overall, our study revealed the critical role of glucose metabolism in the prognosis of patients with glioma. Furthermore, we demonstrated that GALM was significantly related to the malignancy of glioma and could promote glioma cells' EMT process.

Microenvironment Stiffness Amplifies Post-ischemia Heart Regeneration in Response to Exogenous Extracellular Matrix Proteins in Neonatal Mice

The cardiogenesis of the fetal heart is absent in juveniles and adults. Cross-transplantation of decellularized extracellular matrix (dECM) can stimulate regeneration in myocardial infarct (MI) models. We have previously shown that dECM and tissue stiffness have cooperative regulation of heart regeneration in transiently regenerative day 1 neonatal mice. To investigate underlying mechanisms of mechano-signaling and dECM, we pharmacologically altered heart stiffness and administered dECM hydrogels in non-regenerative mice after MI. The dECM combined with softening exhibits preserved cardiac function, LV geometry, increased cardiomyocyte mitosis and lowered fibrosis while stiffening further aggravated ischemic damage. Transcriptome analysis identified a protein in cardiomyocytes, CLCA2, confirmed to be upregulated after MI and downregulated by dECM in a mechanosensitive manner. Synthetic knock-down of CLCA2 expression induced mitosis in primary rat cardiomyocytes in the dish. Together, our results indicate that therapeutic efficacy of extracellular molecules for heart regeneration can be modulated by heart microenvironment stiffness in vivo.

MiR-106b-5p: A Master Regulator of Potential Biomarkers for Breast Cancer Aggressiveness and Prognosis

Breast cancer (BCa) is the leading cause of death by cancer in women worldwide. This disease is mainly stratified in four subtypes according to the presence of specific receptors, which is important for BCa aggressiveness, progression and prognosis. MicroRNAs (miRNAs) are small non-coding RNAs that have the capability to modulate several genes. Our aim was to identify a miRNA signature deregulated in preclinical and clinical BCa models for potential biomarker discovery that would be useful for BCa diagnosis and/or prognosis. We identified hsa-miR-21-5p and miR-106b-5p as up-regulated and hsa-miR-205-5p and miR-143-3p as down-regulated in BCa compared to normal breast or normal adjacent (NAT) tissues. We established 51 shared target genes between hsa-miR-21-5p and miR-106b-5p, which negatively correlated with the miRNA expression. Furthermore, we assessed the pathways in which these genes were involved and selected 12 that were associated with cancer and metabolism. Additionally, GAB1, GNG12, HBP1, MEF2A, PAFAH1B1, PPP1R3B, RPS6KA3 and SESN1 were downregulated in BCa compared to NAT. Interestingly, hsa-miR-106b-5p was up-regulated, while GAB1, GNG12, HBP1 and SESN1 were downregulated in aggressive subtypes. Finally, patients with high levels of hsa-miR-106b-5 and low levels of the abovementioned genes had worse relapse free survival and worse overall survival, except for GAB1.

CTBP1 strengthens the cisplatin resistance of gastric cancer cells by upregulating RAD51 expression

Drug resistance is a key factor affecting the treatment of gastric cancer. The resistance of gastric cancer cells to anticancer drugs, such as cisplatin (DDP), remains a major challenge to patient recovery. The present study aimed to investigate the roles of C-terminal-binding protein 1 (CTBP1) in the DDP resistance of gastric cancer cells and to determine its regulatory effect on DNA repair protein RAD51 homolog 1 (RAD51). The DDP-resistant human gastric cancer AGS and HGC cell lines, AGS/DDP and HGC-27/DDP, respectively, were established and CTBP1 expression was detected by western blotting. In addition, Cell Counting Kit-8, colony formation and flow cytometry assays were performed to detect the proliferation and apoptosis of these two cell lines following CTBP1 knockdown. The expression levels of apoptosis-related proteins were detected by western blotting. In addition, RAD51 was overexpressed in CTBP1 knockdown cells, and proliferation and apoptosis were subsequently determined using the aforementioned methods. The results demonstrated that CTBP1 expression was notably increased in DDP-resistant gastric cancer cells. Furthermore, CTBP1 knockdown suppressed the proliferation and induced the apoptosis of AGS/DDP and HGC-27/DDP cells. Notably, CTBP1 promoted RAD51 expression in DDP-resistant gastric cancer cells. Overexpression of RAD51 in CTBP1 knockdown AGS/DDP and HGC-27/DDP cells rescued the proliferation and alleviated the apoptosis of these cells. Taken together, the results of the present study suggested that CTBP1 may enhance the DDP resistance of gastric cancer cells by activating RAD51 expression, thus providing a potential novel therapy (CTBP1 knockdown) for the clinical treatment of patients with gastric cancer.

Role of ZEB family members in proliferation, metastasis and chemoresistance of prostate cancer cells: Revealing signaling networks

Prostate cancer (PCa) is one of the leading causes of death worldwide. A variety of strategies including surgery, chemotherapy, radiotherapy and immunotherapy are applied for PCa treatment. PCa cells are responsive towards therapy at early stages, but they can obtain resistance in the advanced stage. Furthermore, their migratory ability is high in advanced stages. It seems that genetic and epigenetic factors play an important in this case. Zinc finger E-box-binding homeobox (ZEB) is a family of transcription with two key members including ZEB1 and ZEB2. ZEB family members are known due to their involvement in promoting cancer metastasis via EMT induction. Recent studies have shown their role in cancer proliferation and inducing therapy resistance. In the current review, we focus on revealing role of ZEB1 and ZEB2 in PCa. ZEB family members that are able to significantly promote proliferation and viability of cancer cells. ZEB1 and ZEB2 enhance migration and invasion of PCa cells via EMT induction. Overexpression of ZEB1 and ZEB2 is associated with poor prognosis of PCa. ZEB1 and ZEB2 upregulation occurs during PCa progression and can provide therapy resistance to cancer cells. PRMT1, Smad2, and non-coding RNAs can function as upstream mediators of the ZEB family. Besides, Bax, Bcl-2, MRP1, N-cadherin and E-cadherin can be considered as downstream targets of ZEB family in PCa.

The calcium-activated chloride channel-associated protein rCLCA2 is expressed throughout rat epidermis, facilitates apoptosis and is downmodulated by UVB

The rodent chloride channel regulatory proteins mCLCA2 and its porcine and human homologues pCLCA2 and hCLCA2 are expressed in keratinocytes but their localization and significance in the epidermis have remained elusive. hCLCA2 regulates cancer cell migration, invasion and apoptosis, and its loss predicts poor prognosis in many tumors. Here, we studied the influences of epidermal maturation and UV-irradiation (UVR) on rCLCA2 (previous rCLCA5) expression in cultured rat epidermal keratinocytes (REK) and correlated the results with mCLCA2 expression in mouse skin in vivo. Furthermore, we explored the influence of rCLCA2 silencing on UVR-induced apoptosis. rClca2 mRNA was strongly expressed in REK cells, and its level in organotypic cultures remained unchanged during the epidermal maturation process from a single cell layer to fully differentiated, stratified cultures. Immunostaining confirmed its uniform localization throughout the epidermal layers in REK cultures and in rat skin. A single dose of UVR modestly downregulated rClca2 expression in organotypic REK cultures. The immunohistochemical staining showed that CLCA2 localized in basal and spinous layers also in mouse skin, and repeated UVR induced its partial loss. Interestingly, silencing of rCLCA2 reduced the number of apoptotic cells induced by UVR, suggesting that by facilitating apoptosis, CLCA2 may protect keratinocytes against the risk of malignancy posed by UVB-induced corrupt DNA.

Adipose tissue from metabolic syndrome mice induces an aberrant miRNA signature highly relevant in prostate cancer development

Prostate cancer (PCa) remains an important public health concern in Western countries. Metabolic syndrome (MeS) is a cluster of pathophysiological disorders with increasing prevalence in the general population that is a risk factor for PCa. Several studies have determined that a crosstalk between white adipose tissue (WAT) and solid tumors favors cancer aggressiveness. In this work, our main goal was to investigate the interaction between WAT and PCa cells through microRNAs (miRNAs), in MeS mice. We developed a MeS‐like disease model using C57BL/6J mice chronically fed with high‐fat diet (HFD) that were inoculated with TRAMP‐C1 PCa cells. A group of five miRNAs (mmu‐miR‐221‐3p, 27a‐3p, 34a‐5p, 138‐5p, and 146a‐5p) were increased in gonadal WAT (gWAT), tumors, and plasma of MeS mice compared to control animals. Three of these five miRNAs were detected in the media from gWAT and TRAMP‐C1 cell cocultures, and significantly increased in MeS context. More importantly, hsa‐miR‐221‐3p, 146a‐5p, and 27a‐3p were increased in bloodstream of PCa patients compared to healthy donors. Using miRNA microarrays, we found that 121 miRNAs were differentially released to the coculture media between HFD‐gWAT and tumor cells compared to control diet‐gWAT and tumor cells. Target genes for the 66 most deregulated miRNAs were involved in common pathways, mainly related to fatty acid metabolism, ER protein processing, amino acid degradation, PI3K AKT signaling, and PCa. Our findings show for the first time a signature of five miRNAs as important players involved in the interaction between WAT and PCa in MeS mice. Further research will be necessary to track these miRNAs in the interaction between these tissues as well as their role in PCa patients with MeS.

LINC01426 contributes to clear cell renal cell carcinoma progression by modulating CTBP1/miR-423-5p/FOXM1 axis via interacting with IGF2BP1

Increasing evidence suggests that long noncoding RNAs (lncRNAs) are pivotal regulators in oncogenesis. However, the role of numerous lncRNAs has never been unmasked in clear cell renal cell carcinoma (ccRCC). Presently, we investigated the function of long intergenic nonprotein coding RNA 1426 (LINC01426) in ccRCC, as The Cancer Genome Atlas data indicated that LINC01426 was highly expressed in ccRCC tissues and its overexpression was correlated with disappointing prognosis. First, we verified that LINC01426 was indeed upregulated in ccRCC cell lines and its depletion restrained ccRCC cell proliferation and migration. Besides, we proved that LINC01426 facilitated ccRCC tumorigenesis via forkhead box M1 (FOXM1). Moreover, it was revealed that miR-423-5p was downregulated and directly targeted FOXM1 in ccRCC, and that LINC01426 positively regulated FOXM1 via its inhibition on miR-423-5p. Notably, we also uncovered that miR-423-5p was transcriptionally silenced by CTBP1 and HDAC2. Of importance, LINC01426 was certified to distribute both in the cytoplasm and the nucleus of ccRCC cells, and it increased CTBP1 expression through recruiting insulin like growth factor 2 mRNA binding protein 1 (IGF2BP1) in cytoplasm whereas interacted with CTBP1 protein to improve the transcriptional repression on miR-423-5p in nucleus. Jointly, our observations unveiled that LINC01426 aggravates ccRCC progression via IGF2BP1/CTBP1/HDAC2/miR-423-5p/FOXM1 axis, highlighting LINC01426 as a novel promising target for ccRCC treatment.

Diffuse bone and soft tissue angiomatosis with GNAQ mutation

We describe a unique case of skeletal and extraskeletal angiomatosis complicated by Kasabach-Merritt syndrome. The patient was a 3-year-old boy, who presented with involvement of both femurs and left tibia, as well as with soft tissue lesions of the left thigh. At birth, multiple hemangiomas of the soft tissues of the frontal and parietal scalp had been identified, together with a space-occupying lesion of the lung. Histologically, the skeletal and soft tissue lesions consisted of a proliferation of thin-walled, dilated blood vessels, with an endothelial lining devoid of atypia and exhibiting immunoreactivity for CD31 and CD34, while podoplanin and GLUT1 were negative. Whole exome sequencing performed on samples from the lesion of the femur, the tibia and the skin of the thigh, showed a GNAQ (c.286A>T:p.T96S) variant in all specimens, that was confirmed with digital droplet PCR. This case expands the clinical and pathologic spectrum of vascular proliferations showing similar molecular biology, characterized by GNAQ, GNA11 or GNA14 mutations.

miR-196b-5p-mediated downregulation of TSPAN12 and GATA6 promotes tumor progression in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide and non-small cell lung cancer (NSCLC) accounts for over 80% of lung cancer cases. The RNA binding protein, QKI, belongs to the STAR family and plays tumor-suppressive functions in NSCLC. QKI-5 is a major isoform of QKIs and is predominantly expressed in NSCLC. However, the underlying mechanisms of QKI-5 in NSCLC progression remain unclear. We found that QKI-5 regulated microRNA (miRNA), miR-196b-5p, and its expression was significantly up-regulated in NSCLC tissues. Up-regulated miR-196b-5p promotes lung cancer cell migration, proliferation, and cell cycle through directly targeting the tumor suppressors, GATA6 and TSPAN12. Both GATA6 and TSPAN12 expressions were down-regulated in NSCLC patient tissue samples and were negatively correlated with miR-196b-5p expression. Mouse xenograft models demonstrated that miR-196b-5p functions as a potent onco-miRNA, whereas TSPAN12 functions as a tumor suppressor in NSCLC in vivo. QKI-5 bound to miR-196b-5p and influenced its stability, resulting in up-regulated miR-196b-5p expression in NSCLC. Further analysis showed that hypomethylation in the promoter region enhanced miR-196b-5p expression in NSCLC. Our findings indicate that QKI-5 may exhibit novel anticancer mechanisms by regulating miRNA in NSCLC, and targeting the QKI5∼miR-196b-5p∼GATA6/TSPAN12 pathway may enable effectively treating some NSCLCs.

Downregulation of miR-542-3p promotes osteogenic transition of vascular smooth muscle cells in the aging rat by targeting BMP7

Background

Aging is believed to have a close association with cardiovascular diseases, resulting in various pathological alterations in blood vessels, including vascular cell phenotypic shifts. In aging vessels, the microRNA(miRNA)-mediated mechanism regulating the vascular smooth muscle cell (VSMC) phenotype remains unclarified. MiRNA microarray was used to compare the expressions of miRNAs in VSMCs from old rats (oVSMCs) and young rats (yVSMCs). Quantitative reverse transcription real-time PCR (qRT-PCR) and small RNA transfection were used to explore the miR-542-3p expression in oVSMCs and yVSMCs in vitro. Calcification induction of yVSMCs was conducted by the treatment of β-glycerophosphate (β-GP). Alizarin red staining was used to detect calcium deposition. Western blot and qRT-PCR were used to investigate the expression of the smooth muscle markers, smooth muscle 22α (SM22α) and calponin, and the osteogenic markers, osteopontin (OPN), and runt-related transcription factor 2 (Runx2). Lentivirus was used to overexpress miR-542-3p and bone morphogenetic protein 7 (BMP7) in yVMSCs. Luciferase reporter assay was conducted to identify the target of miR-542-3p.

Results

Compared with yVSMCs, 28 downregulated and 34 upregulated miRNAs were identified in oVSMCs. It was confirmed by qRT-PCR that oVSMC expressed four times lower miR-542-3p than yVSMCs. Overexpressing miR-542-3p in yVSMCs suppressed the osteogenic differentiation induced by β-GP. Moreover, miR-542-3p targets BMP7 and overexpressing BMP7 in miR-542-3p–expressing yVSMCs reverses miR-542-3p’s inhibition of osteogenic differentiation.

Conclusions

miR-542-3p regulates osteogenic differentiation of VSMCs through targeting BMP7, suggesting that the downregulation of miR-542-3p in oVSMCs plays a crucial role in osteogenic transition in the aging rat.

Identification of aberrantly methylated‑differentially expressed genes and gene ontology in prostate cancer

Prostate cancer (PCa) is the most frequent urological malignancy in men worldwide. DNA methylation has an essential role in the etiology and pathogenesis of PCa. The purpose of the present study was to identify the aberrantly methylated-differentially expressed genes and to determine their potential roles in PCa. The important node genes identified were screened by integrated analysis. Gene expression microarrays and gene methylation microarrays were downloaded and aberrantly methylated-differentially expressed genes were obtained. Enrichment analysis and protein-protein interactions (PPI) were obtained, their interactive and visual networks were created, and the node genes in the PPI network were validated. A total of 105 hypomethylation-high expression genes and 561 hypermethylation-low expression genes along with their biological processes were identified. The top 10 node genes obtained from the PPI network were identified for each of the two gene groups. The methylation and gene expression status of node genes in TCGA database, GEPIA tool, and the HPA database were generally consistent with those of our results. In conclusion, the present study identified 20 aberrantly methylated-differentially expressed genes in PCa by combining bioinformatics analyses of gene expression and gene methylation microarrays, and concurrently, the survival of these genes was analyzed. Notably, methylation is a reversible biological process, which makes it of great biological significance for the diagnosis and treatment of prostate cancer using bioinformatics technology to determine abnormal methylation gene markers. The present study provided novel therapeutic targets for the treatment of PCa.

Long noncoding RNA LINC00629 restrains the progression of gastric cancer by upregulating AQP4 through competitively binding to miR-196b-5p

Gastric cancer continues to be a common cancer in the world with high incidence and mortality. Accumulating evidence has implicated long noncoding RNAs (lncRNAs) in gastric cancer progression. Here, this study identified the potential role of a novel lncRNA, LINC00629 in gastric cancer and to elucidate the underlying mechanism. Initially, microarray-based gene expression profiling of gastric cancer was employed to identify differentially expressed genes. Next, the expression of LINC00629, microRNA-196b-5p (miR-196b-5p) and aquaporin 4 (AQP4) in clinical gastric cancer tissues was determined and the cell line presenting with the lowest LINC00629 expression was selected. The interaction among LINC00629, miR-196b-5p, and AQP4 was identified. Expression of LINC00629, miR-196b-5p, and AQP4 in gastric cancer cells were altered and then biological behaviors of gastric cancer cells were assessed by 5-ethynyl-2'-deoxyuridine and Transwell assays. Tumor formation in vivo was evaluated in nude mice. In gastric cancer, expression of LINC00629 and AQP4 was downregulated, and expression of miR-196b-5p was upregulated. Proliferation, invasion, and migration of gastric cancer cells were reduced after overexpression of LINC00629. LINC00629 competitively bound to miR-196b-5p, while AQP4 was a target of miR-196b-5p. Either downregulating miR-196b-5p or upregulating AQP4 could restrain the development of gastric cancer in vitro. LINC00629 overexpression repressed the growth of transplanted tumors in vivo. Taken together, LINC00629 competitively bound to miR-196b-5p to upregulate AQP4 expression, thereby inhibiting gastric cancer progression. Therefore, understanding of this mechanism may help to improve gastric cancer treatment.

Emerging roles for multifunctional ion channel auxiliary subunits in cancer

Several superfamilies of plasma membrane channels which regulate transmembrane ion flux have also been shown to regulate a multitude of cellular processes, including proliferation and migration. Ion channels are typically multimeric complexes consisting of conducting subunits and auxiliary, non-conducting subunits. Auxiliary subunits modulate the function of conducting subunits and have putative non-conducting roles, further expanding the repertoire of cellular processes governed by ion channel complexes to processes such as transcellular adhesion and gene transcription. Given this expansive influence of ion channels on cellular behaviour it is perhaps no surprise that aberrant ion channel expression is a common occurrence in cancer. This review will focus on the conducting and non-conducting roles of the auxiliary subunits of various Ca2+, K+, Na+ and Cl- channels and the burgeoning evidence linking such auxiliary subunits to cancer. Several subunits are upregulated (e.g. Cavβ, Cavγ) and downregulated (e.g. Kvβ) in cancer, while other subunits have been functionally implicated as oncogenes (e.g. Navβ1, Cavα2δ1) and tumour suppressor genes (e.g. CLCA2, KCNE2, BKγ1) based on in vivo studies. The strengthening link between ion channel auxiliary subunits and cancer has exposed these subunits as potential biomarkers and therapeutic targets. However further mechanistic understanding is required into how these subunits contribute to tumour progression before their therapeutic potential can be fully realised.

CTBP1 depletion on prostate tumors deregulates miRNA/mRNA expression and impairs cancer progression in metabolic syndrome mice

About 20% of prostate cancer (PCa) patients progress to metastatic disease. Metabolic syndrome (MeS) is a pathophysiological disorder that increases PCa risk and aggressiveness. C-terminal binding protein (CTBP1) is a transcriptional corepressor that is activated by high-fat diet (HFD). Previously, our group established a MeS/PCa mice model that identified CTBP1 as a novel link associating both diseases. Here, we integrated in vitro (prostate tumor cell lines) and in vivo (MeS/PCa NSG mice) models with molecular and cell biology techniques to investigate MeS/CTBP1 impact over PCa progression, particularly over cell adhesion, mRNA/miRNA expression and PCa spontaneous metastasis development. We found that CTBP1/MeS regulated expression of genes relevant to cell adhesion and PCa progression, such as cadherins, integrins, connexins, and miRNAs in PC3 xenografts. CTBP1 diminished PCa cell adhesion, membrane attachment to substrate and increased filopodia number by modulating gene expression to favor a mesenchymal phenotype. NSG mice fed with HFD and inoculated with CTBP1-depleted PC3 cells, showed a decreased number and size of lung metastases compared to control. Finally, CTBP1 and HFD reduce hsa-mir-30b-5p plasma levels in mice. This study uncovers for the first time the role of CTBP1/MeS in PCa progression and its molecular targets.

CTBP1/CYP19A1/estradiol axis together with adipose tissue impacts over prostate cancer growth associated to metabolic syndrome

Metabolic syndrome (MeS) increases prostate cancer (PCa) risk and aggressiveness. C-terminal binding protein 1 (CTBP1) is a transcriptional co-repressor of tumor suppressor genes that is activated by low NAD⁺ /NADH ratio. Previously, our group established a MeS and PCa mice model that identified CTBP1 as a novel link associating both diseases. We found that CTBP1 controls the transcription of aromatase (CYP19A1), a key enzyme that converts androgens to estrogens. The aim of this work was to investigate the mechanism that explains CTBP1 as a link between MeS and PCa based on CYP19A1 and estrogen synthesis regulation using PCa cell lines, MeS/PCa mice and adipose co-culture systems. We found that CTBP1 and E1A binding protein p300 (EP300) bind to CYP19A1 promoter and downregulate its expression in PC3 cells. Estradiol, through estrogen receptor beta, released CTBP1 from CYP19A1 promoter triggering its transcription and modulating PCa cell proliferation. We generated NSG and C57BL/6J MeS mice by chronically feeding animals with high fat diet. In the NSG model, CTBP1 depleted PCa xenografts showed an increase in CYP19A1 expression with subsequent increment in intratumor estradiol concentrations. Additionally, in C57BL/6J mice, MeS induced hypertrophy, hyperplasia and inflammation of the white adipose tissue, which leads to a proinflammatory phenotype and increased serum estradiol concentration. Thus, MeS increased PCa growth and Ctbp1, Fabp4 and IL-6 expression levels. These results describe, for the first time, a novel CTBP1/CYP19A1/Estradiol axis that explains, in part, the mechanism for prostate tumor growth increase by MeS.