Linc-pint inhibits early stage pancreatic ductal adenocarcinoma growth through TGF-β pathway activation

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.

Exosomal LINC00460/miR-503-5p/ANLN positive feedback loop aggravates pancreatic cancer progression through regulating T cell-mediated cytotoxicity and PD-1 checkpoint

BACKGROUND

Long non-coding RNA (lncRNA) LINC00460 is an onco-lncRNA in a variety of cancers, including pancreatic cancer (PC). This study is aimed to investigate the regulatory mechanisms of LINC00460 in PC.

METHODS

The tumor and adjacent normal tissues were collected from 73 PC patients. The expression of LINC00460, miR-503-5p, and ANLN was detected using qRT-PCR. We then analyzed the proliferation, migration, invasion, and apoptosis/cell cycle of PC cells by performing the MTT/EdU, transwell, and flow cytometry assays, respectively. The xenograft tumor model were utilized to confirm the effect of LINC00460 knockdown on PC through anti-PD-1 therapy in vivo, and the sensitivity of PANC-1 cells to the cytotoxicity of CD8⁺ T cells in vitro. Western blotting was used to determine the protein levels. A co-culture model was utilized to explore the effects of exosomes on macrophages.

RESULTS

LINC00460 was up-regulated in PC tissues and cells. LINC00460 knockdown suppressed cell proliferation, migration, and invasion, facilitated cell apoptosis and G0/G1 phase arrest, and inhibited the tumor growth through anti-PD-1 therapy. Both miR-503-5p down-regulation and ANLN up-regulation reversed the effects of LINC00460 knockdown on inhibiting the proliferation, migration and invasion, and on promoting the apoptosis, G0/G1 phase arrest, and the sensitivity of PC cells to the cytotoxicity of CD8⁺ T cells. Exosomes were uptaken by the ambient PC cells. PANC-1 cells-derived exosomal LINC00460-induced M2 macrophage polarization accelerates the cell migration and invasion.

CONCLUSIONS

LINC00460 silencing attenuates the development of PC by regulating the miR-503-5p/ANLN axis and exosomal LINC00460-induced M2 macrophage polarization accelerates the migration and invasion of PANC-1 cells, thus LINC00460 may act as a possible therapeutic target for treating PC.

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.

Long Non-Coding RNAs in Pancreatic Cancer: Biologic Functions, Mechanisms, and Clinical Significance

Despite tremendous efforts devoted to research in pancreatic cancer (PC), the mechanism underlying the tumorigenesis and progression of PC is still not completely clear. Additionally, ideal biomarkers and satisfactory therapeutic strategies for clinical application in PC are still lacking. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) might participate in the pathogenesis of diverse cancers, including PC. The abnormal expression of lncRNAs in PC is considered a vital factor during tumorigenesis that affects tumor cell proliferation, migration, invasion, apoptosis, angiogenesis, and drug resistance. With this review of relevant articles published in recent years, we aimed to summarize the biogenesis mechanism, classifications, and modes of action of lncRNAs and to review the functions and mechanisms of lncRNAs in PC. Additionally, the clinical significance of lncRNAs in PC was discussed. Finally, we pointed out the questions remaining from recent studies and anticipated that further investigations would address these gaps in knowledge in this field.

LncRNA CCDC144NL-AS1 Serves as a Prognosis Biomarker for Non-small Cell Lung Cancer and Promotes Cellular Function by Targeting miR-490-3p

This study revealed the prognostic significance of long non-coding RNA (lncRNA) CCDC144NL-AS1 in NSCLC patients and discussed the effect and mechanism of proliferation, migration, and invasion of non-small cell lung cancer (NSCLC) cells. 128 pairs of NSCLC tissues and paracancerous tissues were collected, and qRT-PCR was used to detect the differential expression of lncRNA CCDC144NL-AS1 in all tissues and cells lines. Kaplan-Meier analysis and Cox proportional hazards model analysis were used to estimate the prognostic value of lncRNA CCDC144NL-AS1. CCK-8 and Transwell assays confirmed the effect of lncRNA CCDC144NL-AS1 on the proliferation, migration, and invasion of NSCLC. Bioinformatics was used to predict the microRNAs that lncRNA CCDC144NL-AS1 might bind to miR-490-3p. The regulation of lncRNA CCDC144NL-AS1 on miR-490-3p was verified by luciferase activity assay with wide type or mutation. The expression of lncRNA CCDC144NL-AS1 was enhanced in both NSCLC tissues and cell lines. Patients with overexpression of lncRNA CCDC144NL-AS1 have a poor prognosis, and lncRNA CCDC144NL-AS1 is an independent prognostic factor for NSCLC. Increased the relative expression level of lncRNA CCDC144NL-AS1 can promote the proliferation, migration, and invasion of NSCLC cells. LncRNA CCDC144NL-AS1 might target miR-490-3p. LncRNA CCDC144NL-AS1 can be used as an oncogene of NSCLC to predict patient prognosis and promote tumor proliferation, migration, and invasion by targeting miR-490-3p.

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.

LINC-PINT impedes DNA repair and enhances radiotherapeutic response by targeting DNA-PKcs in nasopharyngeal cancer

Radioresistance continues to be the leading cause of recurrence and metastasis in nasopharyngeal cancer. Long noncoding RNAs are emerging as regulators of DNA damage and radioresistance. LINC-PINT was originally identified as a tumor suppressor in various cancers. In this study, LINC-PINT was significantly downregulated in nasopharyngeal cancer tissues than in rhinitis tissues, and low LINC-PINT expressions showed poorer prognosis in patients who received radiotherapy. We further identified a functional role of LINC-PINT in inhibiting the malignant phenotypes and sensitizing cancer cells to irradiation in vitro and in vivo. Mechanistically, LINC-PINT was responsive to DNA damage, inhibiting DNA damage repair through ATM/ATR-Chk1/Chk2 signaling pathways. Moreover, LINC-PINT increased radiosensitivity by interacting with DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and negatively regulated the expression and recruitment of DNA-PKcs. Therefore, these findings collectively support the possibility that LINC-PINT serves as an attractive target to overcome radioresistance in NPC.

Emerging roles of long non-coding RNAs in the p53 network

Transcription factor p53 is activated in response to numerous stress stimuli in order to promote repair and survival or death of abnormal cells. For decades, regulatory mechanisms and downstream targets that execute the many biological functions of tumour suppressor p53 largely focused on the products of protein-coding genes. Recently, an entirely new class of molecules, termed long non-coding RNAs (lncRNAs), were discovered as key regulatory players in shaping p53 activity and biological outcomes. Many p53-regulated lncRNAs are now reported to either directly or indirectly intervene in p53-regulatory networks, generally in fine-tuning p53's tumour surveillance programme. Recent studies reveal that signals that converge upon p53 to regulate its activity, and molecules that implement downstream p53-response include both proteins and lncRNAs. In this review, we discuss the non-proteomic component of p53-regulatory networks, focusing on lncRNAs regulated by p53 and/or that regulate p53 activity, and their impact on biological outcomes.

Non-coding RNAs in Pancreatic Ductal Adenocarcinoma

Non-coding RNAs (ncRNAs) are reported to be expressed in human cancers, including pancreatic ductal adenocarcinoma (PDAC). These ncRNAs affect the growth, migration and invasion of tumor cells by regulating cell cycle and apoptosis, as well as playing important roles in epigenetic processes, transcription and post-transcriptional regulation. It is still unclear whether alterations in ncRNAs influence PDAC development and progression. Because of this, analysis based on existing data on ncRNAs, which are crucial for modulating pancreatic tumorigenesis, will be important for future research on PDAC. Here, we summarize ncRNAs with tumor-promoting functions: HOTAIR, HOTTIP, MALAT1, lncRNA H19, lncRNA PVT1, circ-RNA ciRS-7, circ-0030235, circ-RNA_100782, circ-LDLRAD3, circ-0007534, circRHOT1, circZMYM2, circ-IARS, circ-RNA PDE8A, miR-21, miR-155, miR-221/222, miR-196b, miR-10a. While others including GAS5, MEG3, and lncRNA ENST00000480739, has_circ_0001649, miR-34a, miR-100, miR-217, miR-143 inhibit the proliferation and invasion of PDAC. Hence, we summarize the functions of ncRNAs in the occurrence, development and metastasis of PDAC, with the goal to provide guidance in the clinical diagnosis and treatment of PDAC.

LINC-PINT alleviates lung cancer progression via sponging miR-543 and inducing PTEN

Long intergenic nonprotein coding RNA p53‐induced transcript (LINC‐PINT) has been reported to participate in various cancers. Here, we investigated the effects of LINC‐PINT on lung cancer progression. Firstly, in our study, we implied that LINC‐PINT was obviously decreased in NSCLC. Thereafter, in A549 and H1299 cells, LINC‐PINT was upregulated via transfecting LV‐LINC‐PINT. As exhibited, LINC‐PINT repressed cell proliferation and cell colony formation of A549 and H1299 cells. Subsequently, flow cytometry evidenced that A549 and H1299 cell apoptosis was obviously triggered and the cell cycle was arrested in G1 phase. Then, migration and transwell invasion experiments were carried out to detect the cell migration and invasion capacity. We found A549 and H1299 cell migration and invasion capacity were restrained by the upregulation of LINC‐PINT. Meanwhile, we predicted that miR‐543 could function as the target of LINC‐PINT and the association was verified. Moreover, we exhibited that miR‐543 was remarkably increased in lung cancer, which could be regulated by LINC‐PINT negatively. Furthermore, PTEN could act as the downstream target of miR‐543 and upregulation of miR‐543 repressed PTEN, which was reversed by LV‐PINT in A549 and H1299 cells. Finally, xenografts were utilized to confirm the function of LINC‐PINT on lung cancer. All these findings concluded that LINC‐PINT exerted crucial biological roles in NSCLC through sponging miR‐543 and inducing PTEN.

TGF-β-Mediated Epithelial-Mesenchymal Transition and Cancer Metastasis

Transforming growth factor β (TGF-β) is a secreted cytokine that regulates cell proliferation, migration, and the differentiation of a plethora of different cell types. Consistent with these findings, TGF-β plays a key role in controlling embryogenic development, inflammation, and tissue repair, as well as in maintaining adult tissue homeostasis. TGF-β elicits a broad range of context-dependent cellular responses, and consequently, alterations in TGF-β signaling have been implicated in many diseases, including cancer. During the early stages of tumorigenesis, TGF-β acts as a tumor suppressor by inducing cytostasis and the apoptosis of normal and premalignant cells. However, at later stages, when cancer cells have acquired oncogenic mutations and/or have lost tumor suppressor gene function, cells are resistant to TGF-β-induced growth arrest, and TGF-β functions as a tumor promotor by stimulating tumor cells to undergo the so-called epithelial-mesenchymal transition (EMT). The latter leads to metastasis and chemotherapy resistance. TGF-β further supports cancer growth and progression by activating tumor angiogenesis and cancer-associated fibroblasts and enabling the tumor to evade inhibitory immune responses. In this review, we will consider the role of TGF-β signaling in cell cycle arrest, apoptosis, EMT and cancer cell metastasis. In particular, we will highlight recent insights into the multistep and dynamically controlled process of TGF-β-induced EMT and the functions of miRNAs and long noncoding RNAs in this process. Finally, we will discuss how these new mechanistic insights might be exploited to develop novel therapeutic interventions.