A diagnostic and prognostic value of blood-based circulating long non-coding RNAs in Thyroid, Pancreatic and Ovarian Cancer

The lncRNA TPTEP1 suppresses PI3K/AKT signalling and inhibits ovarian cancer progression by interacting with PTBP1

The expression of the long noncoding RNA (lncRNA) TPTE pseudogene 1 (TPTEP1) is significantly downregulated in ovarian cancer (OC). However, the function and mechanism of the lncRNA TPTEP1 in OC have not been identified. To investigate the expression of the lncRNA TPTEP1, we analysed a publicly available dataset and 20 pairs of OC and normal ovarian samples tissue from the First Affiliated Hospital of Anhui Medical University. Functional assays were used to determine the role of the lncRNA TPTEP1 in OC progression. Furthermore, Western blot, FISH, RNA pull-down, mass spectrometry and RNA immunoprecipitation approaches were used to determine the mechanism by which the lncRNA TPTEP1 affects OC progression. Animal experiments were used to determine the role of the lncRNA TPTEP1 in ovarian tumorigenicity in vivo. The expression of the lncRNA TPTEP1 in OC tissues was significantly lower than that in normal tissues and low expression of the lncRNA TPTEP1 was significantly correlated with advanced FIGO stage and the presence of malignant ascites in OC patients. In vitro and in vivo, regulation of the expression of the lncRNA TPTEP1 caused changes in OC cell proliferation, migration, invasion and apoptosis. Mechanistically, we found that TPTEP1 directly binds to the polypyrimidine tract-binding protein 1 (PTBP1) protein and inhibits PI3K/AKT signalling. The lncRNA TPTEP1 inhibits PI3K/AKT signalling by directly binding PTBP1, possibly indicating the molecular mechanism underlying its biological function. With further research, these findings may aid in the development of clinically useful strategies for the treatment of OC.

Circulating long non-coding RNA EWSAT1 acts as a liquid biopsy marker for esophageal squamous cell carcinoma: A pilot study

The widespread public health problem of esophageal squamous cell carcinoma (ESCC) is the cause of an increasing number of deaths each year due to delayed diagnosis. Therefore, we require specific and sensitive new biomarkers to manage ESCC better. The detection of diseases, such as cancer, can now be achieved through non-invasive circulating blood-based methods. Blood-based circulating non-coding RNAs, such as miRNA and lncRNA, have been extensively used as valuable markers for lung, esophageal, and breast cancer diagnostic purposes, as quoted in our previous research. Herein, we investigated the role of novel long non-coding RNA EWSAT1 as a blood-based liquid biopsy biomarker for the ESCC. Our findings indicate that EWSAT1 lncRNA has an increased tumor suppressive activity in ESCC, as it reduces by ∼2.59-fold relative to healthy controls. Moreover, we established that EWSAT1 expression can significantly distinguish between clinicopathological characteristics, including age, gender, and lifestyle choices such as smoking, alcohol consumption, and drinking hot beverages among patients with ESCC and healthy individuals. In addition, the expression levels of lncRNA EWSAT1 could distinguish between individuals with more advanced ESCC cancer and those without it, as illustrated by the ROC curve (AUC = 0.7174, 95 % confidence intervals = 0.5901 to 0.8448, p-value = 0.001). Our in-silico prediction methods demonstrated that miR-873-5p is the direct target of EWSAT1, which competes with the tumor suppressor candidate 3 (TUSC3) and EGL-9 family hypoxia-inducible factor 3 (EGLN3) mRNAs through a sponging mechanism, creating the EWSAT1/miR-873-5p/mRNA axis. We have analyzed the role of EWSAT1 in various cellular processes and signaling pathways, including mTOR, Wnt, and MAPK signaling pathways. Circulating EWSAT1 can be used as a liquid biopsy marker for diagnosis of ESCC and has the potential to serve as an effective therapeutic biomarker, according to this pilot study.

Insight on Non-Coding RNAs from Biofluids in Ovarian Tumors

Ovarian tumors are the most frequent adnexal mass, raising diagnostic and therapeutic issues linked to a large spectrum of tumors, with a continuum from benign to malignant. Thus far, none of the available diagnostic tools have proven efficient in deciding strategy, and no consensus exists on the best strategy between "single test", "dual testing", "sequential testing", "multiple testing options" and "no testing". In addition, there is a need for prognostic tools such as biological markers of recurrence and theragnostic tools to detect women not responding to chemotherapy in order to adapt therapies. Non-coding RNAs are classified as small or long based on their nucleotide count. Non-coding RNAs have multiple biological functions such as a role in tumorigenesis, gene regulation and genome protection. These ncRNAs emerge as new potential tools to differentiate benign from malignant tumors and to evaluate prognostic and theragnostic factors. In the specific setting of ovarian tumors, the goal of the present work is to offer an insight into the contribution of biofluid non-coding RNAs (ncRNA) expression.

LINC00324 promotes cell proliferation and metastasis of esophageal squamous cell carcinoma through sponging miR-493-5p via MAPK signaling pathway

Long non-coding RNAs have been demonstrated to promote proliferation and metastasis via regulating the miRNA/mRNA regulatory axis in various malignancies. Based on our preliminary study, we investigated the mechanism of LINC00324 through miR-493-5p/MAPK1 in esophageal squamous cell carcinoma (ESCC) pathogenesis. Herein, we confirmed that LINC00324 is significantly upregulated in ESCC primary cells and esophageal squamous cell carcinoma cell line KYSE-70. Silencing of LINC00324 modulates cell proliferation markers, p21, p27, c-Myc, and Cyclin D1 and epithelial-to-mesenchymal transition markers, slug, snail, ZEB1, vimentin, ZO-1, and E-cadherin protein expression in ESCC. Through bioinformatics and dual luciferase reporter assays, we identified miR-493-5p as the direct target molecule of LINC00324. We further revealed that LINC00324 negatively regulates miR-493-5p expression in ESCC. Moreover, our multiple gain-and loss-of-functional experiments proved that a combination of miR-493-5p and LINC00324 significantly rescued ESCC cell proliferation and metastatic phenotypes. Mechanistically, LINC00324 promotes ESCC pathogenesis by acting as a competing endogenous RNA and sponges miR-493-5p activity thereby activating MAPK1 during ESCC progression. We believe that targeting LINC00324 /miR-493-5p/MAPK1 axis may provide new therapeutic avenues for ESCC.

Natural flavonoids exhibit potent anticancer activity by targeting microRNAs in cancer: A signature step hinting towards clinical perfection

Cancer prevalence and its rate of incidence are constantly rising since the past few decades. Owing to the toxicity of present-day antineoplastic drugs, it is imperative to explore safer and more effective molecules to combat and/or prevent this dreaded disease. Flavonoids, a class of polyphenols, have exhibited multifaceted implications against several diseases including cancer, without showing significant toxicity towards the normal cells. Shredded pieces of evidence suggest that flavonoids can enhance drug sensitivity and suppress proliferation, metastasis, and angiogenesis of cancer cells by modulating several oncogenic or oncosuppressor microRNAs (miRNAs, miRs). They play pivotal roles in regulation of various biological and pathological processes, including various cancers. In the present review, the structure, chemistry and miR targeting efficacy of quercetin, luteolin, silibinin, genistein, epigallocatechin gallate, and cyanidin against several cancer types are comprehensively discussed. miRs are considered as next-generation medicine of recent times, and their targeting by naturally occurring flavonoids in cancer cells could be deemed as a signature step. We anticipate that our compilations related to miRNA-mediated regulation of cancer cells by flavonoids might catapult the clinical investigations and affirmation in the future.

miR-590-5p: A double-edged sword in the oncogenesis process

Accumulating evidence suggests the critical role of miR-590-5p in various aspects of cellular homeostasis, including cancer. Furthermore, we and others have recently demonstrated that miRNA-590-5p acts as an oncogene in some cancers while it acts as a tumor-suppressor in others. However, the role of miR-590-5p in oncogenesis is more complex, like a double-edged sword. Thus, this systematic review introduces the concept, mechanism, and biological function of miR-590-5p to resolve this apparent paradox. We have also described the involvement of miR-590-5p in crucial cancer-hallmarks processes like proliferation, invasion, metastasis, and chemo radioresistance. Finally, we have presented the possible genes/pathways targets of miR-590-5p through bioinformatics analysis. This review may help in designing better biomarkers and therapeutic targets for cancers.

Annotation and functional characterization of long noncoding RNAs deregulated in pancreatic adenocarcinoma

PURPOSE

Transcriptome analysis of pancreatic ductal adenocarcinoma (PDAC) has been useful to identify gene expression changes that sustain malignant phenotypes. Yet, most studies examined only tumor tissues and focused on protein-coding genes, leaving long non-coding RNAs (lncRNAs) largely underexplored.

METHODS

We generated total RNA-Seq data from patient-matched tumor and nonmalignant pancreatic tissues and implemented a computational pipeline to survey known and novel lncRNAs. siRNA-mediated knockdown in tumor cell lines was performed to assess the contribution of PDAC-associated lncRNAs to malignant phenotypes. Gene co-expression network and functional enrichment analyses were used to assign deregulated lncRNAs to biological processes and molecular pathways.

RESULTS

We detected 9,032 GENCODE lncRNAs as well as 523 unannotated lncRNAs, including transcripts significantly associated with patient outcome. Aberrant expression of a subset of novel and known lncRNAs was confirmed in patient samples and cell lines. siRNA-mediated knockdown of a subset of these lncRNAs (LINC01559, LINC01133, CCAT1, LINC00920 and UCA1) reduced cell proliferation, migration and invasion. Gene co-expression network analysis associated PDAC-deregulated lncRNAs with diverse biological processes, such as cell adhesion, protein glycosylation and DNA repair. Furthermore, UCA1 knockdown was shown to specifically deregulate co-expressed genes involved in DNA repair and to negatively impact DNA repair following damage induced by ionizing radiation.

CONCLUSIONS

Our study expands the repertoire of lncRNAs deregulated in PDAC, thereby revealing novel candidate biomarkers for patient risk stratification. It also provides a roadmap for functional assays aimed to characterize novel mechanisms of action of lncRNAs in pancreatic cancer, which could be explored for therapeutic development.