Association of long non-coding RNAs and ABO blood groups with acute lymphoblastic leukemia in Egyptian children

Acute lymphoblastic leukemia (ALL) is the most prevailing cancer among children. Despite extensive studies, ALL etiology is still an unsolved puzzle. Long non-coding RNAs (lncRNAs) emerged as key mediators in cancer etiology. Several lncRNAs are dysregulated in ALL, leading to oncogenic or tumor-suppressive activities. Additionally, a relation between ABO blood groups and hematological malignancies was proposed. The current study intended to explore the association of lncRNAs, ANRIL and LINC-PINT, and their downstream targets, CDKN2A and heme oxygenase-1 (HMOX1), with the incidence of ALL and treatment response, and to determine the distribution of blood groups across different childhood ALL phenotypes. Blood samples were taken from 66 ALL patients (at diagnosis and at the end of remission induction phase) and 39 healthy children. Whole blood was used for blood group typing. Expression of ANRIL, LINC-PINT and CDKN2A was analyzed in plasma by qRT-PCR. Serum HMOX1 was measured using ELISA. ANRIL and CDKN2A were upregulated, while LINC-PINT and HMOX1 were downregulated in newly diagnosed patients. All of which showed remarkable diagnostic performance, where HMOX1 was superior. HMOX1 was independent predictor of ALL as well. LINC-PINT and HMOX1 were significantly upregulated after treatment. Notably, ANRIL and LINC-PINT were associated with poor outcome. No significant difference in the distribution of ABO blood groups was observed between patients and controls. In conclusion, our results suggested an association of ANRIL and LINC-PINT with childhood ALL predisposition, at least in part, through altering CDKN2A and HMOX1 production. Furthermore, the impact of remission induction treatment was newly revealed.

Long non-coding RNA LINC-PINT as a novel prognostic biomarker in human cancer: a meta-analysis and machine learning

Long intergenic non-protein coding RNA, P53 induced transcript (LINC-PINT) exhibits different expression patterns in the majority of tumors, yet its relationship with cancer prognosis remains a subject of debate. This study aims to comprehensively investigate the prognostic significance of LINC-PINT in diverse human cancer. A systematic search was conducted in PubMed, Embase, Cochrane Library, and Web of Science databases to identify pertinent studies exploring the correlation between LINC-PINT expression and cancer patients. Moreover, bioinformatics analysis and in vitro validation were used to validate the results of the meta-analysis and to investigate the potential oncogenic mechanism of LINC-PINT. The meta-analysis encompassed 8 studies, involving 911 patients. The pooled analysis demonstrated a significant association between upregulation of LINC-PINT expression and better survival (P = 0.002) during the cancers. Meanwhile, its downregulation was correlated with advanced tumor staging (P = 0.04) and tumor differentiation (P = 0.03). Additionally, bioinformatics analysis showed that LINC-PINT expression was observed to be linked with Tumor Mutational Burden (TMB) and Microsatellite Instability (MSI) in tumors, the results of bioinformatics were verified by qRT-PCR. And functional enrichment analysis hinted at its involvement in tumorigenesis and tumor progression. Dysregulated LICN-PINT expression is associated with the clinical prognostic and pathological features of various cancers, exhibiting substantial potential as a novel prognostic biomarker.

LINC-PINT suppresses breast cancer cell proliferation and migration via MEIS2/PPP3CC/NF-κB pathway by sponging miR-576-5p

BACKGROUND

Breast cancer (BCa) is the most frequent malignant tumor in women. Long non-coding RNAs (lncRNAs) have been acknowledged to exert critical regulating functions in various cancers. Long intergenic non-protein coding RNA, p53 induced transcript (LINC-PINT) has been reported to be a chemosensitizer and a tumor suppressor in BCa. However, its downstream molecular mechanism contributing to its tumor-suppressing role remains to be explored in BCa.

METHODS

LINC-PINT expression in BCa tissues and cells was measured using quantitative real-time polymerase chain reaction (RT-qPCR). The proliferation of transfected BCa cells was examined by counting kit-8 (CCK-8) and EdU assay. The migrating ability of indicate BCa cells was assessed by wound healing assays. Bioinformatics analysis and mechanism experiments such as RNA immunoprecipitation (RIP), RNA pull down assay, and luciferase reporter assay, were applied to demonstrate the downstream targets of LINC-PINT.

RESULTS

LINC-PINT was downregulated in BCa tissues and cell lines. Overexpression of LINC-PINT suppressed BCa cell proliferation and migration. LINC-PINT could interact with miR-576-5p to upregulate Meis homeobox 2 (MEIS2) that positively regulated protein phosphatase 3 catalytic subunit gamma (PPP3CC) by inactivating the nuclear factor-κB (NF-κB) pathway.

CONCLUSIONS

These findings elucidated the anti-tumor role of LINC-PINT in BCa via the miR-576-5p/MEIS2/PPP3CC/NF-κB axis, which suggested that LINC-PINT might serve as a potential therapeutic target for BCa.

Association of LINC-PINT polymorphisms with lumbar disc herniation risk among Chinese Han population: a case control study

BACKGROUND

Lumbar disc herniation (LDH) is a complex spinal disease, with multiple genetic polymorphisms being related to its risk. Nevertheless, the role of LINC-PINT polymorphisms in LDH risk has remained unknown. Therefore, this study aimed to investigate the association between LINC-PINT polymorphisms and LDH risk.

METHODS

DNA was extracted from 504 LDH patients and 500 healthy controls. Three single nucleotide polymorphisms (SNPs) in LINC-PINT were selected and genotyped using Agena MassARRAY. We used logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) under multiple genetic models to evaluate the association between LINC-PINT polymorphisms and LDH risk. Haploview 4.2 and SNPStats software were used to evaluate the linkage strength of SNPs and the correlation between haplotypes and LDH risk. The impact of SNP-SNP interactions on LDH risk was analyzed using multi-factor dimensionality reduction (MDR).

RESULTS

Results showed that rs157916 (G vs. A: OR = 1.23, FDR-p = 0.029) and rs7801029 (G vs. C: OR = 1.39, FDR-p = 0.006; GG vs. CC: OR = 2.34, FDR-p = 0.038; recessive: OR = 2.13, FDR-p = 0.045; additive: OR = 1.39, FDR-p = 0.030) were associated with an increased risk of LDH. Furthermore, LINC-PINT rs157916 and rs780129 were found to be significantly associated with LDH risk in males. The "GGG" haplotype was associated with increased LDH risk (OR = 1.41, FDR-p = 0.006). MDR analysis indicated that the interaction between rs7801029 and rs16873842 was associated with an increased risk of LDH (OR = 1.47, p = 0.004). Additionally, there were significant differences in C-reactive protein levels among different genotypes of rs157916 and rs780129 (p < 0.05).

CONCLUSION

This study suggests that LINC-PINT gene polymorphisms (rs157916 and rs7801029) are considered risk factors for LDH in the Chinese Han population and provide a scientific basis for early screening, prevention, and diagnosis of LDH.

Effects of genetic polymorphisms of LINC-PINT gene on liver cancer susceptibility in the Chinese Han population

Objective: Liver cancer (LC) is the most common cause of cancer mortality. This study aimed to explore the impact of LINC-PINT polymorphisms on LC. Materials & methods: The authors recruited 591 LC patients and 592 healthy controls. The association between LINC-PINT polymorphisms and susceptibility to LC was determined by logistic regression analysis. Results: The authors found that rs157916 and rs16873842 reduced susceptibility to LC. rs157916 decreased LC risk in patients aged <55 years, nondrinkers and those with BMI <24. rs16873842 had a protective role against LC in patients aged ≥55 years, women, nonsmokers and those with BMI ≥24. rs7801029 decreased LC risk in patients with BMI <24. rs28662387 increased LC risk in women. Conclusion: LINC-PINT polymorphisms exert a protective effect against LC.

PINTology: A short history of the lncRNA LINC-PINT in different diseases

LINC-PINT is a p53-induced long intergenic noncoding transcript that plays a crucial role in many diseases, especially cancer. This long noncoding RNA (lncRNA) gene produces in total 102 (LNCipedia) alternatively spliced variants (LINC-PINT:1 to LINC-PINT:102). The functions of known variants include RNA transcripts, host transcripts for circular RNA (circRNA) generation and as sources for the translation of short peptides. In most human tumors, LINC-PINT is down-regulated where it serves as a tumor suppressor. However, the diversity of its functions in other maladies signifies its general clinical importance. Current LINC-PINT molecular functions include RNA-protein interactions, miRNA sponging and epigenetic modulation with these mechanisms operating in different cellular contexts to exert effects on biological processes ranging from DNA damage responses, cell cycle and growth arrest, senescence, cell migration and invasion, and apoptosis. Genetic polymorphisms in LINC-PINT have also been functionally associated with cancer and other pathologies including the autoimmune diseases pemphigus foliaceus and arthritis. Hence, LINC-PINT shows great potential as a clinical biomarker, especially for the diagnosis and prognosis of cancer. In this review, we explore the current knowledge highlighting the distinctive molecular functions of LINC-PINT in specific cancers and other disease states. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Up regulation of long non-coding RNAs BACE1 and down regulation of LINC-PINT are associated with CRC clinicopathological characteristics

BACKGROUND

Long non-coding RNAs (LncRNAs) are known to have regulatory consequences for aberrant gene expression in cancers. The aim of this study was to evaluate the expression levels of long non-encoding RNAs, BACE1 (β-secretase1) and LINC-PINT (Long Intergenic Non-Protein Coding RNA, P53 Induced Transcript), in colorectal cancer (CRC) with clinicopathological parameters.

METHODS AND RESULTS

Bioinformatics analysis defining effectual signalling pathways Wnt. A total of 130 tissue samples (50 fresh CRC tissues with parallel adjacent normal tissues (ADJ) accompanied with 30 normal healthy control tissue samples) were collected from the Iranian population. mRNA expression analysis was performed via Real Time Q-PCR. Statistical analysis for comparing CRC expression levels with ADJ and normal healthy tissues were carried out using Kruskal-Wallis tests. The Receiver Operating Characteristic (ROC) curve was plotted for each LNC, separately. We discovered that PINT and BACE1 expression levels were decreased and increased respectively in CRC tumour samples compared with ADJ normal and healthy tissues. Clinicopathological parameter assessment revealed a significant relationship between PINT expression, tumour location, staging and distant metastasis (p < 0.009, p < 0.014, p < 0.008, respectively). Also, BACE1 over expression was significantly associated with tumour site (p < 0.009), metastasis (p < 0.017) and histological differentiation (p < 0.028) and staging (p < 0.017). Furthermore, ROC curve plotting showed LINC-PINT LNC-BACE1 may distinguish between early and late-stage of CRC, highlighting the value of both BACE1 and PINT as CRC progression biomarkers.

CONCLUSION

We investigated two LNCRNAs (PINT and BACE1) as potential CRC prognostic biomarkers, which are imperative for early and effective medical intervention in CRC. Expression levels of PINT and BACE1 in CRC tissue samples may serve to identify metastasis earlier, increasing patient survival rates and expediating clinical treatment options.

Long intragenic non-coding RNA p53-induced transcript (LINC-PINT) as a novel prognosis indicator and therapeutic target in cancer

Cancer involves complex etiology factors, multiple stages, and intricate gene mutations. Long non-coding RNAs (lncRNAs) are implicated as molecular mechanisms underlying human genomic activity in various physiologic and pathophysiologic conditions. However, the sophisticated modifications and regulatory processes linking lncRNAs to cancer initiation and progression have not yet been fully explored. Long intragenic non-coding RNA p53-induced transcript (LINC-PINT) is an lncRNA that functions as a tumor suppressor gene involved in various tumors and malignant activities. LINC-PINT is downregulated in nasopharyngeal cancer, renal carcinoma, non-small cell lung cancer, glioblastoma, thyroid cancer, retinoblastoma, ovarian cancer, breast cancer, esophageal squamous cell carcinoma, osteosarcoma, melanoma, and gastric cancer. Furthermore, decreased LINC-PINT expression predicts poor prognosis and advanced clinical tumor stages. Together, these studies indicate that LINC-PINT could serve as a diagnostic and prognostic indicator in cancer. The specific lncRNA regulatory mechanism of LINC-PINT may also be a novel target for cancer therapies.

Association between LINC-PINT and LINC00599 gene polymorphism and the risk of steroid-induced osteonecrosis of the femoral head in the population of northern China

BACKGROUND

Steroid-induced osteonecrosis of the femoral head (ONFH) is a complex disease affected by genetics. LncRNA LINC-PINT and LINC00599 have been proved to be associated with susceptibility to a variety of diseases, however it is not clear whether they are related to steroid-induced ONFH. Therefore, this study was aimed at investigating the correlation between the polymorphisms of LINC-PINT and LINC00599 genes and steroid-induced ONFH in the population of northern China.

METHODS

A case-control study including 199 patients and 725 controls was designed. The Agena MassARRAY platform was used for the detection of single nucleotide polymorphisms (SNPs) in LINC-PINT and LINC00599 genes. Chi-square test and logistic regression were used to evaluate the association between the above SNPs and steroid-induced ONFH in allelic and genetic models. Besides, one-way ANOVA was used to study the relationship between these SNPs and partial lipid levels.

RESULTS

In the LINC00599 gene, two sites are related to steroid-induced ONFH. Among them, rs2272026 increased the risk of the disease in co-dominant (heterozygous) and dominant models. And rs1962430 is a risk factor for this disease in the allelic, co-dominance (heterozygous), dominant and additive model. whereas in women with steroid-induced ONFH, three sites in the LINC-PINT gene are related to the disease. Thereinto, rs157916 reduces the risk of the disease in allelic, co-dominant (homozygous), recessive and additive models. Rs16873842 is related to the reduced risk of the disease in allele, dominant and additive models. And rs7781295 is a protective factor for steroid-induced ONFH in the allelic and additive model.

CONCLUSION

Our study suggests that the polymorphisms of LINC-PINT and LINC00599 genes are related to the susceptibility of steroid-induced ONFH in Chinese Han population.

LINC-PINT Inhibited Malignant Progression of Bladder Cancer by Targeting miR-155-5p

BACKGROUND

This study mainly explored the expression level of LINC-PINT in bladder cancer and its relationship with prognosis. Meanwhile, the effect of LINC-PINT on the biological function of bladder cancer was also explored.

METHODS

The expression levels of LINC-PINT and miR-155-5p were detected by qRT-PCR. The prognostic significance of LINC-PINT in bladder cancer was studied by the Kaplan-Meier curve and Log rank test. CCK-8 and Transwell assays were used to analyze the proliferation, migration, and invasion ability. The targeting relationship between LINC-PINT and miR-155-5p was analyzed using bioinformatics and dual-luciferase reporter assays.

RESULTS

The expression of LINC-PINT was downregulated in bladder cancer tissues and cell lines, and miR-155-5p showed the opposite trend in bladder cancer tissues. Kaplan-Meier curve proved that the patients with low LINC-PINT expression had a lower five-year survival rate and the Log rank test displayed that LINC-PINT was a prognostic factor of BC. CCK-8 and Transwell results showed that LINC-PINT could inhibit the ability of proliferation, migration, and invasion. LINC-PINT was proved to target miR-155-5p in bladder cancer. Dual-luciferase reporter gene assay showed that the relative luciferase activity of overexpression miR-155-5p co-transfected with LINC-PINT-wt was significantly lower. LINC-PINT was negatively correlated with miR-155-5p.

CONCLUSION

LINC-PINT is a potential prognostic marker of bladder cancer, and the up-regulation of Lin-PINT can inhibit the proliferation, invasion, and migration of bladder cancer cells by targeting miR-155-5p.

Genome-wide analysis identifies a novel LINC-PINT splice variant associated with vascular amyloid pathology in Alzheimer's disease

Cerebral amyloid angiopathy (CAA) contributes to accelerated cognitive decline in Alzheimer’s disease (AD) dementia and is a common finding at autopsy. The APOEε4 allele and male sex have previously been reported to associate with increased CAA in AD. To inform biomarker and therapeutic target discovery, we aimed to identify additional genetic risk factors and biological pathways involved in this vascular component of AD etiology. We present a genome-wide association study of CAA pathology in AD cases and report sex- and APOE-stratified assessment of this phenotype. Genome-wide genotypes were collected from 853 neuropathology-confirmed AD cases scored for CAA across five brain regions, and imputed to the Haplotype Reference Consortium panel. Key variables and genome-wide genotypes were tested for association with CAA in all individuals and in sex and APOEε4 stratified subsets. Pathway enrichment was run for each of the genetic analyses. Implicated loci were further investigated for functional consequences using brain transcriptome data from 1,186 samples representing seven brain regions profiled as part of the AMP-AD consortium. We confirmed association of male sex, AD neuropathology and APOEε4 with increased CAA, and identified a novel locus, LINC-PINT, associated with lower CAA amongst APOEε4-negative individuals (rs10234094-C, beta = −3.70 [95% CI −0.49—−0.24]; p = 1.63E-08). Transcriptome profiling revealed higher LINC-PINT expression levels in AD cases, and association of rs10234094-C with altered LINC-PINT splicing. Pathway analysis indicates variation in genes involved in neuronal health and function are linked to CAA in AD patients. Further studies in additional and diverse cohorts are needed to assess broader translation of our findings.

LncRNA LINC-PINT Inhibits Malignant Behaviors of Laryngeal Squamous Cell Carcinoma Cells via Inhibiting ZEB1

Objective: Laryngeal squamous cell carcinoma (LSCC) belongs to head and neck squamous cell carcinoma (HNSCC), with dismal prognosis. Here, this study aims to disclose the role of LINC-PINT in cancer development, which may contribute to improving the clinical outcomes of LSCC treatment.

Methods: LINC-PINT expression in LSCC tissues and in TU-177 and Hep-2 cells was quantified, and subsequently, the association between LINC-PINT and LSCC malignancies was analyzed. pcDNA3.1-LINC-PINT or pcDNA3.1-EZH2 was introduced into Hep-2 and TU-177 cells. qRT-PCR and Western blot analyses examined the levels of proteins related to the AKT/mTOR pathway and their phosphorylated proteins in Hep-2 and TU-177 cells. The viability as well as migration and invasion abilities of Hep-2 and TU-177 cells were determined. Also, the distribution of LINC-PINT in Hep-2 cells was investigated as well as the interplay between LINC-PINT and EZH2. The downstream genes that might interact with EZH2 were screened.

Results: LINC-PINT expression was inhibited in LSCC tissues and in Hep-2 and TU-177 cells, whose downregulation was associated with unsatisfactory prognosis. LINC-PINT overexpression suppressed the proliferative, migratory and invasive capacities of Hep-2 and TU-177 cells. LINC-PINT, mainly expressing in nuclei, could enrich EZH2 to silence ZEB1. In Hep-2 and TU-177 cells, the inhibition of LINC-PINT or overexpression of ZEB1 could enhance cell proliferation, migration and invasion. The phosphorylated levels of proteins related to the AKT/mTOR pathway were declined in cells with LINC-PINT overexpression, and the levels of these phosphorylated proteins were increased in cells with LINC-PINT inhibition.

Conclusion: LINC-PINT enriches EZH2 to silence ZEB1 and thus inhibits the proliferative, migratory, and invasive capacities of Hep-2 and TU-177 cells. In addition, LINC-PINT might exert its biological function through the AKT/mTOR pathway.

Genetic variability of immune-related lncRNAs: polymorphisms in LINC-PINT and LY86-AS1 are associated with pemphigus foliaceus susceptibility

Pemphigus foliaceus (PF) is an autoimmune blistering disease of the skin, clinically characterized by erosions and, histopathologically, by acantholysis. PF is endemic in the Brazilian Central-Western region. Numerous single nucleotide polymorphisms (SNPs) have been shown to affect the susceptibility for PF, including SNPs at long non-coding RNA (lncRNA) genes, which are known to participate in many physiological and pathogenic processes, such as autoimmunity. Here, we investigated whether the genetic variation of immune-related lncRNA genes affects the risk for endemic and sporadic forms of PF. We analysed 692 novel SNPs for PF from 135 immune-related lncRNA genes in 227 endemic PF patients and 194 controls. The SNPs were genotyped by Illumina microarray and analysed by applying logistic regression at additive model, with correction for sex and population structure. Six associated SNPs were also evaluated in an independent German cohort of 76 sporadic PF patients and 150 controls. Further, we measured the expression levels of two associated lncRNA genes (LINC-PINT and LY86-AS1) by quantitative PCR, stratified by genotypes, in peripheral blood mononuclear cells of healthy subjects. We found 27 SNPs in 11 lncRNA genes associated with endemic PF (p < .05 without overlapping with protein-coding genes). Among them, the LINC-PINT SNP rs10228040*A (OR = 1.47, p = .012) was also associated with increased susceptibility for sporadic PF (OR = 2.28, p = .002). Moreover, the A+ carriers of LY86-AS1*rs12192707 mark lowest LY86-AS1 RNA levels, which might be associated with a decreasing autoimmune response. Our results suggest a critical role of lncRNA variants in immunopathogenesis of both PF endemic and sporadic forms.

Long Noncoding RNA LINC-PINT Suppresses Cell Proliferation, Invasion, and EMT by Blocking Wnt/β-Catenin Signaling in Glioblastoma

Background: Glioblastoma (GBM) represents the most aggressive glioma with high invasive potential. Recent studies proved the involvement of epithelial-mesenchymal transition (EMT) process in increasing the malignancy and invasiveness of GBM. LncRNAs have been verified to play pivotal roles in human disease including GBM. However, the molecular mechanisms of lncRNA-mediated EMT in GBM remain largely unknown. LINC-PINT, a LncRNA which has never been studied in GBM before, was predicted to be negatively associated with EMT in GBM. This study aimed to explore the biological function and the EMT relevance of LINC-PINT in GBM and further explore the molecular mechanism.

Methods: The bioinformatic prediction data of LINC-PINT in GBM was derived from The Cancer Genome Atlas (TCGA) database by R software and GEPIA website. qRT-PCR assay was performed to detect the expression level of LINC-PINT in GBM cell lines. Cell counting kit-8 (CCK8), clone formation, transwell, and wound healing assays were performed to determine the biological function of LINC-PINT in vivo. Tumor xenograft experiment and tumor peritoneal metastasis experiments were performed to verify the in vivo function. Western blot and immunofluorescence staining assays were carried out to detect the relevance of LINC-PINT with EMT and Wnt/β-catenin signaling. Rescue assays were performed to check the regulation mechanism of LINC-PINT/Wnt signaling/EMT axis in GBM.

Results: LINC-PINT was downregulated in GBM cell lines. LINC-PINT suppressed cell progression, invasion, and EMT in GBM. LINC-PINT blocked Wnt/β-catenin signaling in GBM.

Conclusion: LINC-PINT suppressed cell proliferation, invasion, and EMT by blocking Wnt/β-catenin signaling in GBM.

Long non-coding RNA LINC-PINT attenuates paclitaxel resistance in triple-negative breast cancer cells via targeting the RNA-binding protein NONO

The treatment of triple-negative breast cancer (TNBC) relies largely on chemotherapies. However, it is frequent that TNBC patients develop resistance to the chemotherapy drugs. Generation of drug-resistant cell lines facilitates the identification of drug resistance. Here, we established two paclitaxel (PTX)-resistant TNBC cancer cell lines using an intermittent and stepwise method and found that long non-coding RNA long intergenic non-protein-coding RNA p53-induced transcript (LINC-PINT) was significantly decreased in PTX-resistant cancer cells. Ectopic expression of LINC-PINT sensitized both PTX-resistant TNBC and wild-type TNBC to PTX. Moreover, RNA immunoprecipitation showed that LINC-PINT bound to RNA-binding protein NONO. Overexpression of LINC-PINT resulted in the degradation of NONO in a proteasome-dependent manner and vice versa. Knockdown of NONO with siRNA sensitized TNBC to PTX. We further analyzed the expression level of LINC-PINT and NONO in patient samples via online database and found that LINC-PINT and NONO may function antagonistically in all types of breast cancers. Taken together, our data illustrated a tumor suppressor role of LINC-PINT in sensitizing TNBC to chemotherapies via destabilizing NONO.

LINC-PINT suppresses tumour cell proliferation, migration and invasion through targeting miR-374a-5p in ovarian cancer

LncRNA LINC-PINT acts as an important regulator in the development of many cancers. The current study aimed to explore the role of LINC-PINT in the progression of ovarian cancer (OC). LINC-PINT expression level in different FIGO stages of OC and its adjacent tissues, normal HOSE and OC cell lines (A2780, SKOV3, OVCAR3 and HO-8910) was determined by qRT-PCR. Survival analysis on LINC-PINT and OC patients was conducted by Kaplan-Meier. CCK-8, flow cytometry, wound-healing, Transwell assays and western blot were performed to detect the effects of LINC-PINT on proliferation, apoptosis, migration, invasion and EMT process in OC cells. Target gene of LINC-PINT was predicted by Starbase and verified by dual-luciferase reporter assay. The expression of miR-374a-5p in normal and OC tissues, LINC-PINT- or siLINC-PINT-modified OC cells was determined. Moreover, rescue assay was carried out to confirm whether LINC-PINT contributes to the development of OC cells through targeting miR-374a-5p. Low expression of LINC-PINT was observed in OC tissues and cells, noticeably, LINC-PINT expression was even lower in OC tissues with higher FIGO stage. Increased LINC-PINT expression significantly inhibited cell proliferation, promoted apoptosis and suppressed migration, invasion and EMT process, while silencing of LINC-PINT caused the opposite results. Moreover, LINC-PINT sponged miR-374a-5p and overexpressed miR-374a-5p attenuated the effect of up-regulated LINC-PINT on cell viability, migration, invasion and apoptosis. LINC-PINT acts as a tumour suppressor, as it could inhibit cell proliferation, migration, invasion and EMT process, and promote cell apoptosis through down-regulating miR-374a-5p. SIGNIFICANCE OF THE STUDY: Ovarian cancer (OC), which is a frequently diagnosed tumour in female reproductive organs, has a high incidence rate behind cervical cancer and endometrial cancer. LncRNA LINC-PINT acts as an important regulator in the development of many cancers. The current study aimed to explore the role of LINC-PINT in the progression of ovarian cancer (OC) and found that LINC-PINT inhibited cell proliferation, migration invasion and EMT process of OC cell via regulating miR-374a-5p; it might be a potential target for OC treatment.

LINC-PINT Suppresses the Aggressiveness of Thyroid Cancer by Downregulating miR-767-5p to Induce TET2 Expression

Long noncoding RNA (lncRNA) long intergenic nonprotein-coding RNA, p53-induced transcript (LINC-PINT) has shown anti-invasive activity in lung and colon cancer cells. However, the role of LINC-PINT in thyroid cancer is unclear. In the present work, we explored the expression of LINC-PINT in 60 paired thyroid cancer and adjacent normal tissues. The clinical significance and biological function of LINC-PINT in thyroid cancer were determined. LINC-PINT expression was downregulated in thyroid cancer relative to adjacent normal tissues (p = 0.0002). Low expression of LINC-PINT was significantly associated with advanced tumor node metastasis (TNM) stage (p = 0.0306) and lymph node metastasis (p = 0.0359). Ectopic expression of LINC-PINT suppressed the proliferation, invasion, and tumorigenesis of thyroid cancer cells. Mechanistically, LINC-PINT associated with and downregulated microRNA (miR)-767-5p. Moreover, LINC-PINT overexpression relieved miR-767-5p-mediated repression of ten-eleven translocation 2 (TET2). miR-767-5p promoted aggressiveness of thyroid cancer, which was reversed by overexpression of TET2. Coexpression of miR-767-5p or depletion of TET2 rescued the inhibitory effect of LINC-PINT on thyroid cancer cell proliferation and invasion. In addition, there was a negative correlation between miR-767-5p and LINC-PINT in thyroid cancer (r = -0.34772, p = 0.01789). Taken together, LINC-PINT functions as a tumor suppressor in thyroid cancer via the miR-767-5p/TET2 axis, representing a potential therapeutic target for thyroid cancer.

Downregulation of lncRNA LINC-PINT Participates in the Recurrence of Esophageal Squamous Cell Carcinoma Possibly by Interacting miRNA-21

Backgrounds: LncRNA long intergenic non-protein coding RNA p53 induced transcript (LINC-PINT) is downregulated in multiple types of cancer cells. The authors explored the possible involvement of LINC-PINT in esophageal squamous cell carcinoma (ESCC). Materials and Methods: Sixty-two patients with early-stage ESCC were included in this study. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect gene expression in plasma from ESCC patients and healthy controls. Diagnostic analysis was performed by receiver operating characteristic (ROC) curve. Transfections were performed to analyze gene interactions. Cell invasion and migration were analyzed by Transwell assays. Results: Plasma LINC-PINT was downregulated and microRNA (miRNA)-21 was upregulated in early-stage ESCC patients. Diagnostic analysis by ROC curve revealed that downregulation of lncRNA LINC-PINT distinguished ESCC patients from healthy controls. Plasma levels of LINC-PINT and miRNA-21 were negatively correlated in ESCC patients. After surgical resection, only local recurrence was observed during 3-years of follow-up. LINC-PINT expression was further downregulated in recurrent patients but not in nonrecurrent patients. ROC curve analysis revealed that plasma levels of LINC-PINT at 12 months before recurrence can be used to distinguish ESCC patients from healthy controls. Overexpression of LINC-PINT could inhibit the expression of miRNA-21 in human ESCC cells, whereas LINC-PINT expression was not altered by miR-21 overexpression. Conclusion: Therefore, downregulation of LINC-PINT participated in the recurrence of ESCC possibly by interacting with miRNA-21.

A lncRNA survey finds increases in neuroprotective LINC-PINT in Parkinson's disease substantia nigra

Recent reports highlight regulatory functions of long noncoding RNAs (lncRNAs) in neurodegeneration and aging, but biomedical implications remain limited. Here, we report an rRNA‐depletion‐based long RNA‐Sequencing Resource of 65 substantia nigra, amygdala, and medial temporal gyrus samples from Parkinson's disease (PD) and matched control brains. Using a lncRNA‐focused analysis approach to identify functionally important transcripts, we discovered and prioritized many lncRNAs dysregulated in PD. Those included pronounced elevation of the P53‐induced noncoding transcript LINC‐PINT in the substantia nigra of PD patients, as well as in additional models of oxidative stress and PD. Intriguingly, we found that LINC‐PINT is a primarily neuronal transcript which showed conspicuous increases in maturing primary culture neurons. LINC‐PINT also accumulated in several brain regions of Alzheimer's and Huntington's disease patients and decreased with healthy brain aging, suggesting a general role in aging and neurodegeneration for this lncRNA. RNAi‐mediated depletion of LINC‐PINT exacerbated the death of cultured N2A and SH‐SY5Y cells exposed to oxidative stress, highlighting a previously undiscovered neuroprotective role for this tumor‐inducible lncRNA in the brains of patients with neurodegenerative disorders.

Long Non-coding RNA LINC-PINT Suppresses Cell Proliferation and Migration of Melanoma via Recruiting EZH2

Long non-coding RNAs (lncRNAs) have been identified as crucial regulators in many human cancers. Many lncRNAs show aberrant expression in cancer, and some of them play critical roles in tumor proliferation, invasion, and metastasis. However, the regulatory functions of lncRNAs in melanoma progression remain to be elucidated. We utilized the Real-time PCR methodology to determine the expression of LINC-PINT in melanoma cell lines. To evaluate the effect of LINC-PINT on tumorigenesis of melanoma, we used Cell Counting Kit-8 (CCK8) and colony formation assay. Flow cytometry assay was used to detect the function of LINC-PINT on cell cycle status. PINT-interacting proteins were identified by chromatin isolation using RNA purification (ChIRP). Microarray assay and bioinformatics analysis were used to find the potential target genes of LINC-PINT and the status of LINC-PINT target gene candidate was verified using chromatin immunoprecipitation assay (ChIP). LINC-PINT plays a role in suppressing the tumorigenicity of melanoma, which was further determined by xenograft model assay. LINC-PINT was significantly downregulated in melanoma tissues and cell lines. The overexpression of LINC-PINT in tumor cells resulted in significant tumor growth reduction and migration inhibition in A375, Mum2B and CRMM1 cells. Results based on the in vivo xenograft model were further consistent with the in vitro findings that LINC-PINT impeded growth and metastasis of melanoma cells. Microarray assay and bioinformatics analysis indicated that CDK1, CCNA2, AURKA, and PCNA were potential targets of LINC-PINT. In conclusion, LINC-PINT inhibits the tumorigenicity of melanoma through recruiting EZH2 to the promoter of its target genes, leading to H3K27 trimethylation and epigenetic silencing of target genes. LINC-PINT may serve as a novel diagnostic and therapeutic target for melanoma.

Long noncoding RNA LINC-PINT promotes proliferation through EZH2 and predicts poor prognosis in clear cell renal cell carcinoma

Background: Renal cell carcinoma (RCC) is one of the most common types of urological malignant tumors. Despite recent advances in diagnosis and management of RCC, its prognosis remains poor. Emerging evidence has shown that long noncoding RNAs (lncRNAs) play crucial regulatory roles in cancer biology.

Materials and methods: The most abundant transcript of long intergenic non-protein coding RNA p53 induced transcript (LINC-PINT) in clear cell RCC (ccRCC) was determined by RT-PCR. Quantitative real-time PCR was performed to examine LINC-PINT expression in paired ccRCC samples and cell lines. The relationship of LINC-PINT expression with clinicopathologic characteristics and clinical outcome was analyzed. The biological function of LINC-PINT was studied by MTS and colony formation. The flow cytometry was used to analyze cell cycle distribution and apoptosis. The subcelluar fractionation and RIP assay was performed to explore the molecular mechanism of LINC-PINT. Western blotting and immunofluorescence was carried out to examine EZH2 and p53.

Results: We found that the LINC-PINT was frequently upregulated in ccRCC samples. Furthermore, we observed that the level of LINC-PINT depended on gender as well as on pT and TNM stage of patients with ccRCC. Moreover, patients with high LINC-PINT expression had poor disease-free survival and overall survival. Functionally, overexpression of LINC-PINT promoted ccRCC cell proliferation, induced cell cycle progression, and inhibited apoptosis. LINC-PINT was primarily located in cell nuclei and interacted with EZH2. When EZH2 was knocked down in 769P and OS-RC-2 cells overexpressing LINC-PINT, the effect of LINC-PINT on cell proliferation, cell cycle, and apoptosis was partially reversed. Additionally, inducing p53 by doxorubicin (Dox) promoted LINC-PINT expression.

Conclusion: Collectively, our results provide novel insights into the important role of LINC-PINT in ccRCC development and indicate that LINC-PINT may serve as a valuable prognostic biomarker for ccRCC.

Long noncoding RNA LINC-PINT regulates laryngeal carcinoma cell stemness and chemoresistance through miR-425-5p/PTCH1/SHH axis

Functional, noncoding RNA of about 200 nucleotides in length are known as long noncoding RNA (lncRNA). Advances in -omics have revolutionized the information with respect to the coding and noncoding regions of the genome. Several studies have illustrated the role of lncRNA in cell growth and cancer. Profiling and bioinformatic studies of laryngeal cancer has identified LINC-PINT as one of the lncRNA. However, the functional aspects of the deregulation have not been studied in laryngeal tumors. In this study, LINC-PINT expression in normal and tumor tissues were studied. Using a bioinformatic approach, microRNA (miRNA) targets of LINC-PINT and gene targets of the miRNA were determined. The impact of LINC-PINT on cell proliferation and chemoresistance was determined. Further through a set of silencing and re-expression studies phenotype rescue was studied. LINC-PINT expression was downregulated in laryngeal tumors. LINC-PINT targeted miR-425-5p by three sites. miR-425-5p also targeted PTCH1 a protein of the Hedgehog pathway. Downregulation of LINC-PINT was associated with increased cancer stemness and chemoresistance to cisplatin. Our results indicate a probable role of LINC-PINT in the pathology of laryngeal tumors. LINC-PINT re-expression in laryngeal tumors may be explored for reversion of cancer cell stemness and also for rescue of drug resistance phenotype.