Circ_100395 impedes malignancy and glycolysis in papillary thyroid cancer: involvement of PI3K/AKT/mTOR signaling pathway

Reprogramming of Thyroid Cancer Metabolism: from Mechanism to Therapeutic Strategy

Thyroid cancer as one of the most prevalent malignancies of endocrine system, has raised public concern and more research on its mechanism and treatment. And metabolism-based therapies have advanced rapidly, for the exclusive metabolic profiling of thyroid cancer. In thyroid cancer cells, plenty of metabolic pathways are reprogrammed to accommodate tumor microenvironment. In this review, we initiatively summarize recent progress in the full-scale thyroid cancer metabolic rewiring and the interconnection of various metabolites. We also discuss the efficacy and prospect of metabolic targeted detection as well as therapy. Comprehending metabolic mechanism and characteristics of thyroid cancer roundly will be highly beneficial to managing individual patients.

METTL3-Induced m6A Modification Enhances Hsa_Circ_0136959 Expression to Impair the Tumor Characteristics of Papillary Thyroid Carcinoma via Accelerating Ferroptosis

The number of cases of papillary thyroid cancer (PTC) has gone up significantly in recent years, with high recurrence. Numerous reports have highlighted the participation of circular RNAs (circRNAs) in regulating the advancement of cancers, including PTC. Furthermore, recent studies suggest that N6-methyladenosine (m6A) modified circRNAs play pivotal roles in cancer progression. Hence, we studied the potential role of a novel circRNA, hsa_circ_0136959, and its regulatory mechanism on m6A modification by methyltransferase-like 3 (METTL3) in the tumor characteristics of PTC. The expressions of hsa_circ_0136959 and METTL3 were evaluated in PTC samples and cell lines via quantitative real-time polymerase chain reaction. The effect of hsa_circ_0136959 on the malignant properties of PTC was analyzed by performing Cell Counting Kit-8, colony formation, and transwell assays. In addition, its effects on the levels of markers related to ferroptosis (reactive oxygen species, Fe2+, and iron) in PTC cells were also assessed. Bioinformatics analysis was done to determine the hsa_circ_0136959 expression and m6A modification sites on it in PTC. The m6A level of hsa_circ_0136959 was analyzed through methylated (m6A) RNA immunoprecipitation. The hsa_circ_0136959 was observed to be downregulated in both PTC samples and cells. In vitro experiments showed that its overexpression impeded the malignant properties of PTC cells. Moreover, hsa_circ_0136959 overexpression increased the levels of ferroptosis-related markers in PTC cells. We also found that METTL3 was notably reduced in PTC samples and was positively correlated with hsa_circ_0136959. Mechanistically, METTL3 enhanced hsa_circ_0136959 expression through m6A modification. Our results demonstrate that METTL3-mediated m6A modification elevated hsa_circ_0136959 expression and subsequently restricted the tumor characteristics of PTC by accelerating ferroptosis.

Emerging roles of non-coding RNAs in modulating the PI3K/Akt pathway in cancer

Cancer progression results from the dysregulation of molecular pathways, each with unique features that can either promote or inhibit tumor growth. The complexity of carcinogenesis makes it challenging for researchers to target all pathways in cancer therapy, emphasizing the importance of focusing on specific pathways for targeted treatment. One such pathway is the PI3K/Akt pathway, which is often overexpressed in cancer. As tumor cells progress, the expression of PI3K/Akt increases, further driving cancer advancement. This study aims to explore how ncRNAs regulate the expression of PI3K/Akt. NcRNAs are found in both the cytoplasm and nucleus, and their functions vary depending on their location. They can bind to the promoters of PI3K or Akt, either reducing or increasing their expression, thus influencing tumorigenesis. The ncRNA/PI3K/Akt axis plays a crucial role in determining cell proliferation, metastasis, epithelial-mesenchymal transition (EMT), and even chemoresistance and radioresistance in human cancers. Anti-tumor compounds can target ncRNAs to modulate the PI3K/Akt axis. Moreover, ncRNAs can regulate the PI3K/Akt pathway both directly and indirectly.

Midkine promotes thyroid cancer cell migration and invasion by activating the phosphatidylinositol 3 kinase/protein kinase B/mammalian target of rapamycin pathway

Objective

Thyroid cancer (TC) therapy, which is routinely used at present, can improve patients' survival rates. However, lymph node metastasis results in a higher degree of TC malignancy in patients who experience recurrence and/or death. The elucidation of new mechanisms of TC metastasis can help identify new therapeutic targets. Midkine (MDK) is expressed aberrantly in various cancers. However, the regulatory mechanisms of MDK in TC remain largely unknown. Hence, this study mainly explores the effect and molecular function of MDK in TC.

Material and Methods

MDK gene expression and protein levels were analyzed using the Gene Expression Profiling Interactive Analysis and the Human Protein Atlas online databases. MDK messenger RNA (mRNA) in TC was analyzed by quantitative real-time polymerase chain reaction. MDK, phosphatidylinositol 3 kinase (PI3K), phosphorylated AKT (p-AKT), and phosphorylated mammalian target of rapamycin (p-mTOR) protein in TC were analyzed by Western blotting. Transwell and wound healing assays were performed to evaluate TC cell metastasis.

Results

MDK mRNA was significantly highly expressed in most patients with TC (P < 0.05). Moreover, MDK gene expression levels correlated with different TC stages. MDK protein was negative in normal tissues and positive in TC tissues. MDK mRNA and protein were significantly highly expressed in TC cells (P < 0.01). Compared with metastasis in the control group, that in the MDK group is significantly suppressed by MDK knockdown (P < 0.001). MDK knockdown also significantly inhibited PI3K, p-AKT, and p-mTOR protein expression in TPC-1 and K1 cells (P < 0.001). The activation of PAmT-P significantly enhanced the PI3K, p-AKT, and p-mTOR protein expression in TPC-1 and K1 cells (P < 0.001) and promoted metastasis (P < 0.001), thereby disrupting the inhibitory effect of the MDK knockdown.

Conclusion

Our findings confirmed that MDK promotes TC migration and invasion by activating PAmT-P. MDK is a novel molecular target for the treatment of patients with metastatic TC.

The role of genetic and epigenetic modifications as potential biomarkers in the diagnosis and prognosis of thyroid cancer

Thyroid cancer (TC) is the most common endocrine cancer, which contributes to more than 43,600 deaths and 586,000 cases worldwide every year. Among the TC types, PTC and FTC comprise 90% of all TCs. Genetic modifications in genes are responsible for encoding proteins of mitogen-associated protein kinase cascade, which is closely related with numerous cellular mechanisms, including controlling programmed cell death, differentiation, proliferation, gene expression, as well as in genes encoding the PI3K (phosphatidylinositol 3-kinase)/protein kinase B (AKT) cascade, which has contribution in controlling cell motility, adhesion, survival, and glucose metabolism, have been associated with the TC pathogenesis. Various genetic modifications including BRAF mutations, RAS mutations, RET mutations, paired-box gene 8/peroxisome proliferator-activated receptor-gamma fusion oncogene, RET/PTC rearrangements, telomerase reverse transcriptase mutations, neurotrophic tyrosine receptor kinase fusion genes, TP53 mutations, and eukaryotic translation initiation factor 1A X-linked mutations can effectively serve as potential biomarkers in both diagnosis and prognosis of TC. On the other hand, epigenetic modifications can lead to aberrant functions or suppression of a range of signalling cascades, which can ultimately result in cancer. Various studies have observed the link between epigenetic modification and multiple cancers including TC. It has been reported that several epigenetic alterations including histone modifications, aberrant DNA methylation, and epigenetic modulations of non-coding RNAs can play significant roles as potential biomarkers in the diagnosis and prognosis of TC. Therefore, a good understanding regarding the genetic and epigenetic modifications is not only essential for the diagnosis and prognosis of TC, but also for the development of novel therapeutics. In this review, most of the major TC-related genetic and epigenetic modifications and their potential as biomarkers for TC diagnosis and prognosis have been extensively discussed.

Circular RNAs: characteristics, functions, mechanisms, and potential applications in thyroid cancer

Thyroid cancer (TC) is one of the most common endocrine malignancies, and its incidence has increased globally. Despite extensive research, the underlying molecular mechanisms of TC remain partially understood, warranting continued exploration of molecular markers for diagnostic and prognostic applications. Circular RNAs (circRNAs) have recently garnered significant attention owing to their distinct roles in cancers. This review article introduced the classification and biological functions of circRNAs and summarized their potential as diagnostic and prognostic markers in TC. Further, the interplay of circRNAs with PI3K/Akt/mTOR, Wnt/β-catenin, MAPK/ERK, Notch, JAK/STAT, and AMPK pathways is elaborated upon. The article culminates with an examination of circRNA's role in drug resistance of TC and highlights the challenges in circRNA research in TC.

Circ_PRDM5/miR-25-3p/ANKRD46 axis is associated with cell malignant behaviors in subjects with breast cancer evaluated by ultrasound

Circular RNAs (circRNAs) are key RNA molecules in cancer biology. CircRNA PR/SET domain 5 (circ_PRDM5, hsa_circ_0005654) was downregulated in breast cancer (BC) tissues. This study is designed to investigate the functional mechanism of circ_PRDM5 in BC. Ultrasound examinations were performed to evaluate BC patients and normal individuals. Circ_PRDM5, miR-25-3p, and Ankyrin repeat domain 46 (ANKRD46) level detection was carried out by reverse transcription-quantitative polymerase chain reaction. 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay was used for cell viability examination. Cell proliferation was evaluated by ethynyl-2'-deoxyuridine assay and colony formation assay. The protein levels were examined using western blot. Cell migration and invasion abilities were assessed via transwell assay. Target interaction was analyzed via dual-luciferase reporter assay. The role of circ_PRDM5 in vivo was explored via xenograft tumor assay. Circ_PRDM5 expression was downregulated in BC tissues and cells. Overexpression of circ_PRDM5 suppressed proliferation and motility but enhanced apoptosis of BC cells. Circ_PRDM5 served as a sponge of miR-25-3p. Circ_PRDM5 impeded BC cell malignant development via sponging miR-25-3p. Circ_PRDM5 induced ANKRD46 upregulation by targeting miR-25-3p. Inhibition of miR-25-3p retarded BC progression by increasing the ANKRD46 level. Circ_PRDM5 repressed BC tumorigenesis in vivo through mediating the miR-25-3p/ANKRD46 axis. This study evidenced that circ_PRDM5 inhibited cell progression and tumor growth in BC via interacting with mir-25-3p/ANKRD46 network.

Network pharmacology-based prediction and experimental verification of the involvement of the PI3K/Akt pathway in the anti-thyroid cancer activity of crocin

Crocin, a unique water-soluble carotenoid extracted from saffron, is known to exert anticancer activity against various cancer types, including thyroid cancer (TC). However, the detailed mechanism underlying the anticancer effect of crocin in TC needs further exploration. Targets of crocin and targets associated with TC were acquired from public databases. Gene Ontology (GO) and KEGG pathway enrichment analyses were performed using DAVID. Cell viability and proliferation were assessed using MMT and EdU incorporation assays, respectively. Apoptosis was assessed using TUNEL and caspase-3 activity assays. The effect of crocin on phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) was explored by western blot analysis. A total of 20 overlapping targets were identified as candidate targets of crocin against TC. GO analysis showed that these overlapping genes were significantly enriched in the positive regulation of cell proliferation. KEGG results showed that the PI3K/Akt pathway was involved in the effect of crocin against TC. Crocin treatment inhibited cell proliferation and promoted apoptosis in TC cells. Moreover, we found that crocin inhibited the PI3K/Akt pathway in TC cells. 740Y-P treatment reversed the effects of crocin on TC cells. In conclusion, crocin suppressed proliferation and elicited apoptosis in TC cells via inactivation of the PI3K/Akt pathway.

Research progress of circRNA in malignant tumour metabolic reprogramming

Cancer is a multi-factor systemic malignant disease, which has seriously threatened human health and created a heavy burden on the world economy. Metabolic reprogramming, one of the important signs of malignant tumours, provides necessary nutrition for tumorigenesis and cancer development; thus, it has recently become a research hot spot, even though the metabolic mechanism is quite intricate. Circular RNA (circRNA) affects cancer cell metabolism through various molecular mechanisms, playing an important role in promoting or suppressing cancer. Because of the structure characteristics, circRNA is quite stable, and can be utilized as biomarkers. In this review, we analysed and summarized the characteristics and biological functions of circRNA and comprehensively reviewed and discussed the important role of circRNA in cancer metabolic reprogramming. This review will provide new ideas for developing new anti-cancer therapeutic targets, mining cancer diagnostic and prognostic markers, and will provide guidance for other researchers to design circRNA-related experiments and develop anti-tumour drugs.

The Emerging Roles of circRNAs in Papillary Thyroid Carcinoma: Molecular Mechanisms and Biomarker Potential

Papillary thyroid carcinoma (PTC) is a common endocrine malignant tumor. The incidence of PTC has increased in the past decades and presents a younger trend. Accumulating evidence indicates that circular RNAs (circRNAs), featured with non-linear, closed-loop structures, play pivotal roles in tumorigenesis and regulate cell biological processes, such as proliferation, migration, and invasion, by acting as microRNA (miRNA) sponges. Additionally, due to their unique stability, circRNAs hold promising potential as diagnostic biomarkers and effective therapeutic targets for PTC treatment. In this review, we systematically arrange the expression level of circRNAs, related clinical characteristics, circRNA-miRNA-mRNA regulatory network, and molecular mechanisms. Furthermore, related signaling pathways and their potential ability of diagnostic biomarkers and therapeutic targets are discussed, which might provide a new strategy for PTC diagnosis, monitoring, and prognosis.

Long Noncoding RNAs and Circular RNAs Regulate AKT and Its Effectors to Control Cell Functions of Cancer Cells

AKT serine-threonine kinase (AKT) and its effectors are essential for maintaining cell proliferation, apoptosis, autophagy, endoplasmic reticulum (ER) stress, mitochondrial morphogenesis (fission/fusion), ferroptosis, necroptosis, DNA damage response (damage and repair), senescence, and migration of cancer cells. Several lncRNAs and circRNAs also regulate the expression of these functions by numerous pathways. However, the impact on cell functions by lncRNAs and circRNAs regulating AKT and its effectors is poorly understood. This review provides comprehensive information about the relationship of lncRNAs and circRNAs with AKT on the cell functions of cancer cells. the roles of several lncRNAs and circRNAs acting on AKT effectors, such as FOXO, mTORC1/2, S6K1/2, 4EBP1, SREBP, and HIF are explored. To further validate the relationship between AKT, AKT effectors, lncRNAs, and circRNAs, more predicted AKT- and AKT effector-targeting lncRNAs and circRNAs were retrieved from the LncTarD and circBase databases. Consistently, using an in-depth literature survey, these AKT- and AKT effector-targeting database lncRNAs and circRNAs were related to cell functions. Therefore, some lncRNAs and circRNAs can regulate several cell functions through modulating AKT and AKT effectors. This review provides insights into a comprehensive network of AKT and AKT effectors connecting to lncRNAs and circRNAs in the regulation of cancer cell functions.