The KRAS/Lin28B axis maintains stemness of pancreatic cancer cells via the let-7i/TET3 pathway

LIN28B induced PCAT5 promotes endometrial cancer progression and glycolysis via IGF2BP3 deubiquitination

Endometrial cancer (EC) cells exhibit abnormal glucose metabolism, characterized by increased aerobic glycolysis and decreased oxidative phosphorylation. Targeting cellular glucose metabolism in these cells could be an effective therapeutic approach for EC. This study aimed to assess the roles of LIN28B, PCAT5, and IGF2BP3 in the glucose metabolism, proliferation, migration, and invasion of EC cells. LIN28B highly expressed in EC, binds and stabilizes PCAT5. PCAT5, overexpressed in EC, and its 1485-2288nt region can bind to the KH1-2 domain of IGF2BP3 to prevent MKRN2 from binding to the K294 ubiquitination site of IGF2BP3, thus stabilizing IGF2BP3. Finally, IGF2BP3 promotes the aerobic glycolysis, proliferation, migration and invasion of EC cells by stabilizing the key enzymes of glucose metabolism HK2 and PKM2. Taken together, our data reveal that the LIN28B/PCAT5/IGF2BP3 axis is critical for glucose reprogramming and malignant biological behavior in EC cells. Therefore, targeting this axis may contribute to the development of a novel therapeutic strategy for EC metabolism.

Revealing neuropilin expression patterns in pancreatic cancer: From single‑cell to therapeutic opportunities (Review)

Pancreatic cancer, one of the most fatal types of human cancers, includes several non-epithelial and stromal components, such as activated fibroblasts, vascular cells, neural cells and immune cells, that are involved in different cancers. Vascular endothelial cell growth factor 165 receptors 1 [neuropilin-1 (NRP-1)] and 2 (NRP-2) play a role in the biological behaviors of pancreatic cancer and may appear as potential therapeutic targets. The NRP family of proteins serve as co-receptors for vascular endothelial growth factor, transforming growth factor β, hepatocyte growth factor, fibroblast growth factor, semaphorin 3, epidermal growth factor, insulin-like growth factor and platelet-derived growth factor. Investigations of mechanisms that involve the NRP family of proteins may help develop novel approaches for overcoming therapy resistance in pancreatic cancer. The present review aimed to provide an in-depth exploration of the multifaceted roles of the NRP family of proteins in pancreatic cancer, including recent findings from single-cell analysis conducted within the context of pancreatic adenocarcinoma, which revealed the intricate involvement of NRP proteins at the cellular level. Through these efforts, the present study endeavored to further reveal their relationships with different biological processes and their potential as therapeutic targets in various treatment modalities, offering novel perspectives and directions for the treatment of pancreatic cancer.

Exploring Lin28 proteins: Unravelling structure and functions with emphasis on nervous system malignancies

Cancer and stem cells share many characteristics related to self-renewal and differentiation. Both cell types express the same critical proteins that govern cellular stemness, which provide cancer cells with the growth and survival benefits of stem cells. LIN28 is an example of one such protein. LIN28 includes two main isoforms, LIN28A and LIN28B, with diverse physiological functions from tissue development to control of pluripotency. In addition to their physiological roles, LIN28A and LIN28B affect the progression of several cancers by regulating multiple cancer hallmarks. Altered expression levels of LIN28A and LIN28B have been proposed as diagnostic and/or prognostic markers for various malignancies. This review discusses the structure and modes of action of the different LIN28 proteins and examines their roles in regulating cancer hallmarks with a focus on malignancies of the nervous system. This review also highlights some gaps in the field that require further exploration to assess the potential of targeting LIN28 proteins for controlling cancer.

Identification of potential pseudogenes for predicting the prognosis of hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) remains a highly deadly malignant tumor with high recurrence and metastasis rates. Cancer stem cells (CSCs) are involved in tumor metastasis, recurrence, and resistance to drugs, which have attracted widespread attention in recent years. Research has shown that pseudogenes may regulate stemness to promote the progression of HCC, but its specific mechanisms and impact on prognosis remain unclear.

METHODS

In this study, clinical prognosis information of HCC was first downloaded from The Cancer Genome Atlas (TCGA) database. Then we calculated the mRNA expression-based stemness index (mRNAsi) of HCC. We also screened the differentially expressed pseudogene (DEPs) and conducted univariate Cox regression analysis to investigate their effect on the prognosis of HCC. Further, genomic mutation frequency analysis and weighted gene co-expression network analysis (WGCNA) were performed to compare the role of pseudogenes and stemness in promoting the progression of HCC. Finally, we conducted the correlation analysis to examine the potential mechanism of pseudogenes regulating stemness to promote the progression of HCC and detected the possible pathways through the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis.

RESULTS

Herein, we revealed that the high stemness of HCC correlated with an unfavorable prognosis. We obtained 31 up-regulated and 8 down-regulated DEPs in HCC and screened CTB-63M22.1, a poor prognostic indicator of HCC. In addition, CTB-63M22.1 had a mutation frequency similar to mRNAsi and acted in a module similar to that of mRNAsi on HCC. We then screened two RNA-binding proteins (RBPs) LIN28B and NOP56 with the highest correlation with stemness. We also discovered that they were primarily enriched in the biological process as examples of mitotic nuclear division and cell cycle.

CONCLUSIONS

Collectively, these results revealed that pseudogenes CTB-63M22.1 may regulate cancer stemness by regulating RBPs, suggesting that CTB-63M22.1 may serve as an innovative therapeutic target and a reliable prognostic marker for HCC.

Dual mechanism of Let-7i in tumor progression

Let-7i regulates tumors primarily by binding to the 3' untranslated region (3' UTR) of mRNA, which indirectly regulates post-transcriptional gene expression. Let-7i also has an epigenetic function via modulating DNA methylation to directly regulate gene expression. Let-7i performs a dual role by inducing both the promotion and inhibition of various malignancies, depending on its target. The mechanism of Let-7i action involves cancer cell proliferation, migration, invasion, apoptosis, epithelial-mesenchymal transition, EV transmission, angiogenesis, autophagy, and drug resistance sensitization. Let-7i is closely related to cancer, and hence, is a potential biomarker for the diagnosis and prognosis of various cancers. Therapeutically, it can be used to promote an anti-cancer immune response by modifying exosomes, thus exerting a tumor-suppressive effect.

The novel oncogenic factor TET3 combines with AHR to promote thyroid cancer lymphangiogenesis via the HIF-1α/VEGF signaling pathway

BACKGROUND

Lymphangiogenesis has been reported to play crucial roles in the metastasis of thyroid cancer (THCA), but despite the significant research on lymphangiogenesis in THCA, the precise regulatory mechanism remains unclear.

METHODS

Public databases including the Cancer Genome Atlas (TCGA), TIMER, and UALCAN were used to analyze and visualize the expression of TET3 and AHR in THCA, and the correlation between these molecules were used by TIMER. Additionally, RT-PCR and Western Blot were performed to determine the mRNA and protein expression of related proteins. Plate colony formation, wound healing, cell cycle, apoptosis, angiogenesis and transwell assay were used to examine the ability of proliferation, movement, lymphangiogenesis, migration and invasion of THCA cells.

RESULTS

Analysis of the TCGA database revealed higher expression levels of TET3 and AHR in tumor tissue compared to normal tissue in THCA. Additionally, a strong correlation was observed between TET3 and AHR. UALCAN database demonstrated that high expression of TET3 and AHR was associated with advanced THCA TNM stages in THCA patients. Furthermore, TET3 activation accelerated THCA cell proliferation by inducing G2/M phase arrest and suppressing apoptosis, while AHR inactivation reduced THCA cell proliferation by decreasing G2/M phase arrest and promoting apoptosis in vitro. Notably, both TET3 and AHR significantly enhanced THCA cell lymphangiogenesis, migration and invasion. Moreover, TET3 activation and AHR inactivation regulated HIF-1α/VEGF signaling pathway, which ultimately, blocked the HIF-1α/VEGF in THCA cells and impaired their movement, migration and invasion abilities.

CONCLUSIONS

The combined action of TET3 and AHR to promote lymphangiogenesis in THCA through the HIF-1α/VEGF signaling pathway, and targeting them might provide a potential treatment strategy for THCA.

Let7i A key player and a promising biomarker in diseases

MicroRNAs (miRNAs) are endogenous non-coding single-stranded small RNAs that regulate gene expression by recognizing homologous sequences and interfering with transcriptional, translational or epigenetic processes. MiRNAs are involved in a variety of disease processes, and regulate the physiological and pathological status of diseases by modulating target cell activity, migration, invasion, apoptosis, autophagy and other processes. Among them, let-7i is highly expressed in various systems, which participates in the process of tumors, cardiovascular and cerebrovascular diseases, fibrotic diseases, inflammatory diseases, neurodegenerative diseases and other diseases, and plays a positive or negative regulatory role in these diseases through different signal pathways and key molecules. Moreover, it can be used as an early diagnosis and prognostic marker for a variety of diseases and become a potential therapeutic target. As a biomarker, let-7i is frequently tested in combination with other miRNAs to diagnose multiple diseases and evaluate the clinical treatment or prognosis.

LIN28B and Let-7 in Diffuse Midline Glioma: A Review

Diffuse midline glioma (DMG) is the most lethal of all childhood cancers. DMGs are driven by histone-tail-mutation-mediated epigenetic dysregulation and partner mutations in genes controlling proliferation and migration. One result of this epigenetic and genetic landscape is the overexpression of LIN28B RNA binding protein. In other systems, LIN28B has been shown to prevent let-7 microRNA biogenesis; however, let-7, when available, faithfully suppresses tumorigenic pathways and induces cellular maturation by preventing the translation of numerous oncogenes. Here, we review the current literature on LIN28A/B and the let-7 family and describe their role in gliomagenesis. Future research is then recommended, with a focus on the mechanisms of LIN28B overexpression and localization in DMG.

The role of LIN28B in tumor progression and metastasis in solid tumor entities

LIN28B is an RNA-binding protein that targets a broad range of microRNAs and modulates their maturation and activity. Under normal conditions, LIN28B is exclusively expressed in embryogenic stem cells, blocking differentiation and promoting proliferation. In addition, it can play a role in epithelial-to-mesenchymal transition by repressing the biogenesis of let-7 microRNAs. In malignancies, LIN28B is frequently overexpressed, which is associated with increased tumor aggressiveness and metastatic properties. In this review, we discuss the molecular mechanisms of LIN28B in promoting tumor progression and metastasis in solid tumor entities and its potential use as a clinical therapeutic target and biomarker.

miR-488-5p mitigates hepatic stellate cell activation and hepatic fibrosis via suppressing TET3 expression

BACKGROUND AND AIMS

Numerous studies have demonstrated that hepatic fibrosis, a progressive condition as an endpoint of multiple chronic hepatic diseases, is largely characterized with the extensive activation of hepatic stellate cells (HSCs). The precise effect of miR-488-5p in HSCs during hepatic fibrosis has not been elucidated.

METHODS

In our study, qRT-PCR was applied to assess the level of miR-488-5p in activated HSCs stimulated by TGF-β1. We built murine liver fibrosis models with carbon tetrachloride (CCl4), high-fat diet (HFD) and bile duct ligation (BDL). In vitro, the effects of miR-488-5p in HSCs were examined through cell proliferation assay and apoptosis. Luciferase reporter assay was applied to identify the underlying target of miR-488-5p. In vivo, the effects of miR-488-5p were explored through mouse liver fibrosis models.

RESULTS

The reduction of miR-488-5p in the activated HSCs induced by TGF-β1 and three mouse hepatic fibrosis models were identified. The in vitro functional experimentations verified that miR-488-5p restrained expression of fibrosis-related markers and proliferative capacity in HSCs. Mechanically, we identified that miR-488-5p inhibited tet methylcytosine dioxygenase 3 (TET3) expression via straightly binding onto the 3' UTR of its mRNA, which sequentially restrained the TGF-β/Smad2/3 pathway. TET3 inhibition induced by the overexpression of miR-488-5p reduced extracellular matrix deposition, which contributed to mitigating mouse liver fibrosis.

CONCLUSION

We highlight that miR-488-5p restrains the activation of HSCs and hepatic fibrosis via targeting TET3 which is involved in the TGF-β/Smad2/3 signaling pathway. Collectively, miR-488-5p is identified as a potential therapeutic target for hepatic fibrosis.

Associations of selenoprotein expression and gene methylation with the outcome of clear cell renal carcinoma

Selenoproteins are a ubiquitous class of proteins defined by having a selenocysteine amino acid residue. While many of the selenoproteins have been well characterized with important roles in oxidation-reduction reactions and hormone synthesis among others, there exist some whose biological roles are not as well understood as denoted by the "SELENO" root. In this study, we explored associations between the reported RNA levels of "SELENO" proteins and clear cell renal cell carcinoma (ccRCC), the most common subtype of renal carcinoma in the US. Utilizing The Cancer Genome Atlas (TCGA) alongside other in silico tools, we discovered higher mRNA expression of Selenoprotein I, T, and P was associated with better overall survival outcomes and differential expression of other selenoproteins based on tumor stage. Additionally, we uncovered relative hypomethylation among selenoproteins in primary ccRCC tumor samples compared to normal tissue. Network and enrichment analysis showed numerous genes through which selenoproteins may modulate cancer progression and outcomes such as DERL1, PNPLA2/3, MIEN1, and FOXO1 which have been well-described in other cancers. In light of our findings highlighting an association of selenoprotein methylation and expression patterns with ccRCC outcome, further wet lab research is warranted.

5mC modification patterns provide novel direction for early acute myocardial infarction detection and personalized therapy

Background

Most deaths from coronary artery disease (CAD) are due to acute myocardial infarction (AMI). There is an urgent need for early AMI detection, particularly in patients with stable CAD. 5-methylcytosine (5mC) regulatory genes have been demonstrated to involve in the progression and prognosis of cardiovascular diseases, while little research examined 5mC regulators in CAD to AMI progression.

Method

Two datasets (GSE59867 and GSE62646) were downloaded from Gene Expression Omnibus (GEO) database, and 21 m5C regulators were extracted from previous literature. Dysregulated 5mC regulators were screened out by "limma." The least absolute shrinkage and selection operator (LASSO) and support vector machine recursive feature elimination (SVM-RFE) algorithm were employed to identify hub 5mC regulators in CAD to AMI progression, and 43 clinical samples (Quantitative real-time PCR) were performed for expression validation. Then a logistic model was built to construct 5mC regulator signatures, and a series of bioinformatics algorithms were performed for model validation. Besides, 5mC-associated molecular clusters were studied via unsupervised clustering analysis, and correlation analysis between immunocyte and 5mC regulators in each cluster was conducted.

Results

Nine hub 5mC regulators were identified. A robust model was constructed, and its prominent classification accuracy was verified via ROC curve analysis (area under the curve [AUC] = 0.936 in the training cohort and AUC = 0.888 in the external validation cohort). Besides, the clinical effect of the model was validated by decision curve analysis. Then, 5mC modification clusters in AMI patients were identified, along with the immunocyte infiltration levels of each cluster. The correlation analysis found the strongest correlations were TET3-Mast cell in cluster-1 and TET3-MDSC in cluster-2.

Conclusion

Nine hub 5mC regulators (DNMT3B, MBD3, UHRF1, UHRF2, NTHL1, SMUG1, ZBTB33, TET1, and TET3) formed a diagnostic model, and concomitant results unraveled the critical impact of 5mC regulators, providing interesting epigenetics findings in AMI population vs. stable CAD.

Vitamin C Sensitizes Pancreatic Cancer Cells to Erastin-Induced Ferroptosis by Activating the AMPK/Nrf2/HMOX1 Pathway

Ferroptosis is a type of regulated cell death that displays a promising therapeutic pathway for drug-resistant tumor cells. However, some pancreatic cancer (PC) cells are less sensitive to erastin-induced ferroptosis, and normal pancreatic cells are susceptible to this newly discovered cell death. Therefore, there is an urgent need to find drugs to enhance the sensitivity of these PC cells to erastin while limiting side effects. Here, we found that the oxidized form of vitamin C-dehydroascorbic acid (DHA) can be transported into PC cells expressing high levels of GLUT1, resulting in ferroptosis. Moreover, pharmacological vitamin C combined with erastin can synergistically induce ferroptosis of PC cells involving glutathione (GSH) reduction and ferrous iron accumulation while inhibiting the cytotoxicity of normal cells. Mechanistically, as a direct system Xc^- inhibitor, erastin can directly suppress the synthesis of GSH, and the recycling of vitamin C and DHA is performed through GSH consumption, which is denoted as the classical mode. Furthermore, oxidative stress induced by erastin and vitamin C could enhance the expression of HMOX1 via the AMP-activated protein kinase (AMPK)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway to increase the labile iron level, which is named the nonclassical mode. In vivo experiments showed that erastin and vitamin C can significantly slow tumor growth in PC xenografts. In summary, the combination of erastin and vitamin C exerts a synergistic effect of classical and nonclassical modes to induce ferroptosis in PC cells, which may provide a promising therapeutic strategy for PC.

The Role of Feedback Loops in Targeted Therapy for Pancreatic Cancer

Pancreatic cancer is the leading cause of cancer-related deaths worldwide, with limited treatment options and low long-term survival rates. The complex and variable signal regulation networks are one of the important reasons why it is difficult for pancreatic cancer to develop precise targeted therapy drugs. Numerous studies have associated feedback loop regulation with the development and therapeutic response of cancers including pancreatic cancer. Therefore, we review researches on the role of feedback loops in the progression of pancreatic cancer, and summarize the connection between feedback loops and several signaling pathways in pancreatic cancer, as well as recent advances in the intervention of feedback loops in pancreatic cancer treatment, highlighting the potential of capitalizing on feedback loops modulation in targeted therapy for pancreatic cancer.

LINC01094 promotes pancreatic cancer progression by sponging miR-577 to regulate LIN28B expression and the PI3K/AKT pathway

The leading cause of death in pancreatic cancer (PC) patients is the progression of cancer metastasis. Recently, long non-coding RNAs (lncRNAs) have been shown to play an important role in regulating cancer cell proliferation and metastasis; however, its molecular basis in PC remains to be explored. In this study, we observed that LINC01094 was markedly overexpressed in PC tissues and was associated with poor patient prognosis. Downregulation of LINC01094 decreased the proliferation and metastasis of PC cells and inhibited tumorigenesis and metastasis in mouse xenografts. Mechanically, LINC01094 acted as an endogenous miR-577 sponge to increase the expression of its target gene, the RNA-binding protein lin-28 homolog B (LIN28B), by decoying the miR-577, thereby activating the PI3K/AKT pathway. Our findings suggest that LINC01094 plays critical roles in proliferation and metastasis of PC, implying that LINC01094 can be regarded as a new biomarker or therapeutic target for the treatment of PC.

The Roles of the Let-7 Family of MicroRNAs in the Regulation of Cancer Stemness

Cancer has long been viewed as a disease of normal development gone awry. Cancer stem-like cells (CSCs), also termed as tumor-initiating cells (TICs), are increasingly recognized as a critical tumor cell population that drives not only tumorigenesis but also cancer progression, treatment resistance and metastatic relapse. The let-7 family of microRNAs (miRNAs), first identified in C. elegans but functionally conserved from worms to human, constitutes an important class of regulators for diverse cellular functions ranging from cell proliferation, differentiation and pluripotency to cancer development and progression. Here, we review the current state of knowledge regarding the roles of let-7 miRNAs in regulating cancer stemness. We outline several key RNA-binding proteins, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) involved in the regulation of let-7 biogenesis, maturation and function. We then highlight key gene targets and signaling pathways that are regulated or mutually regulated by the let-7 family of miRNAs to modulate CSC characteristics in various types of cancer. We also summarize the existing evidence indicating distinct metabolic pathways regulated by the let-7 miRNAs to impact CSC self-renewal, differentiation and treatment resistance. Lastly, we review current preclinical studies and discuss the clinical implications for developing let-7-based replacement strategies as potential cancer therapeutics that can be delivered through different platforms to target CSCs and reduce/overcome treatment resistance when applied alone or in combination with current chemo/radiation or molecularly targeted therapies. By specifically targeting CSCs, these strategies have the potential to significantly improve the efficacy of cancer therapies.

Mutations of p53 associated with pancreatic cancer and therapeutic implications

Pancreatic adenocarcinoma is a malignancy with rising incidence and grim prognosis. Despite improvements in therapeutics for treating metastatic pancreatic cancer, this disease is invariably fatal with survival time less than a few years. New molecular understanding of the pathogenesis of pancreatic adenocarcinoma based on efforts led by The Cancer Genome Atlas and other groups has elucidated the landscape of this disease and started to produce therapeutic results, leading to the first introduction of targeted therapies for subsets of pancreatic cancers bearing specific molecular lesions such as BRCA mutations. These efforts have highlighted that subsets of pancreatic cancers are particularly sensitive to chemotherapy. The most common molecular lesions in pancreatic adenocarcinomas are mutations in an oncogene KRAS and the TP53 gene that encodes for tumor suppressor protein p53. This paper will review the landscape of pancreatic cancers, focusing on mutations of p53, a major tumor suppressor protein, in pancreatic cancers and possible therapeutic repercussions.