Antagonistic Roles of the Tumor Suppressor miR-210-3p and Oncomucin MUC4 Forming a Negative Feedback Loop in Pancreatic Adenocarcinoma

miR-210 Mediated Hypoxic Responses in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one among the most lethal malignancies due to its aggressive behavior and resistance to conventional therapies. Hypoxia significantly contributes to cancer progression and therapeutic resistance of PDAC. microRNAs (miRNAs/miRs) have emerged as critical regulators of various biological processes. miR-210 is known as the "hypoxamir" due to its prominent role in cellular responses to hypoxia. In this study, we investigated the multifaceted role of miR-210 in PDAC using miR-210 knockout (KO) cellular models to elucidate its functions under hypoxic conditions. Hypoxia-inducible factor-1α (HIF1-α), a key transcription factor activated in response to low oxygen levels, upregulates miR-210. miR-210 maintains cancer stem cell (CSC) phenotypes and promotes epithelial-mesenchymal transition (EMT), which is essential for tumor initiation, metastasis, and therapeutic resistance. Our findings demonstrate that miR-210 regulates the expression of CSC markers, such as CD24, CD44, and CD133, and EMT markers, including E-cadherin, Vimentin, and Snail. Specifically, depletion of miR-210 reversed EMT and CSC marker expression levels in hypoxic Panc-1 and MiaPaCa-2 PDAC cells. These regulatory actions facilitate a more invasive and treatment-resistant PDAC phenotype. Understanding the regulatory network involving miR-210 under hypoxic conditions may reveal new therapeutic targets for combating PDAC and improving patient outcomes. Our data suggest that miR-210 is a critical regulator of HIF1-α expression, EMT, and the stemness of PDAC cells in hypoxic environments.

Ginsenoside 20(S)-Rg3 Hinders Esophageal Squamous Cell Carcinoma Cells Malignant Behaviors by miR-210-3p/B4GALT5 Axis

Ginsenoside 20(S)-Rg3 (20(S)-Rg3) belongs to a natural chemical with an anti-tumor function, but its potential function and underlying mechanism in esophageal squamous cell carcinoma (ESCC) are unknown. Several reports have manifested that microRNA (miRNA) miR-210-3p functions as a tumor repressor in tumors, but its biofunction in ESCC remains obscure. Herein, the role and interaction of 20(S)-Rg3 and miR-210-3p in ESCC cells were investigated. We performed a series of functional experiments to validate that 20(S)-Rg3 notably restrained ESCC cell proliferation and migration while promoting cell apoptosis. Besides, miR-210-3p was found to be lowly expressed in ESCC cells. Overexpressing miR-210-3p suppressed the malignant behaviors of ESCC cells. More importantly, 20(S)-Rg3 could upregulate miR-210-3p expression in ESCC cells. MiR-210-3p knockdown offset the inhibitive impacts of 20(S)-Rg3 treatment on ESCC cell growth and migration. Furthermore, through luciferase reporter assay, beta-1,4-galactosyltransferase 5 (B4GALT5) was certified to be targeted by miR-210-3p. B4GALT5 upregulation neutralized the suppressive function of 20(S)-Rg3 on ESCC progression. Overall, 20(S)-Rg3 attenuated malignant behaviors of ESCC cells by modulating miR-210-3p/B4GALT5 axis, indicating 20(S)-Rg3 has therapeutic potential for ESCC.

Autophagy and the pancreas: Healthy and disease states

Macroautophagy/autophagy is an intracellular degradation pathway that has an important effect on both healthy and diseased pancreases. It protects the structure and function of the pancreas by maintaining organelle homeostasis and removing damaged organelles. A variety of pancreas-related diseases, such as diabetes, pancreatitis, and pancreatic cancer, are closely associated with autophagy. Genetic studies that address autophagy confirm this view. Loss of autophagy homeostasis (lack or overactivation) can lead to a series of adverse reactions, such as oxidative accumulation, increased inflammation, and cell death. There is growing evidence that stimulating or inhibiting autophagy is a potential therapeutic strategy for various pancreatic diseases. In this review, we discuss the multiple roles of autophagy in physiological and pathological conditions of the pancreas, including its role as a protective or pathogenic factor.

Resistance to Gemcitabine in Pancreatic Ductal Adenocarcinoma: A Physiopathologic and Pharmacologic Review

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor with a poor prognosis and inadequate response to treatment. Many factors contribute to this therapeutic failure: lack of symptoms until the tumor reaches an advanced stage, leading to late diagnosis; early lymphatic and hematic spread; advanced age of patients; important development of a pro-tumoral and hyperfibrotic stroma; high genetic and metabolic heterogeneity; poor vascular supply; a highly acidic matrix; extreme hypoxia; and early development of resistance to the available therapeutic options. In most cases, the disease is silent for a long time, andwhen it does become symptomatic, it is too late for ablative surgery; this is one of the major reasons explaining the short survival associated with the disease. Even when surgery is possible, relapsesare frequent, andthe causes of this devastating picture are the low efficacy ofand early resistance to all known chemotherapeutic treatments. Thus, it is imperative to analyze the roots of this resistance in order to improve the benefits of therapy. PDAC chemoresistance is the final product of different, but to some extent, interconnected factors. Surgery, being the most adequate treatment for pancreatic cancer and the only one that in a few selected cases can achieve longer survival, is only possible in less than 20% of patients. Thus, the treatment burden relies on chemotherapy in mostcases. While the FOLFIRINOX scheme has a slightly longer overall survival, it also produces many more adverse eventsso that gemcitabine is still considered the first choice for treatment, especially in combination with other compounds/agents. This review discusses the multiple causes of gemcitabine resistance in PDAC.

Circular RNA coiled-coil domain containing 66 regulates malignant development of papillary thyroid carcinoma by upregulating La ribonucleoprotein 1 via the sponge effect on miR-129-5p

Circular RNAs (circRNAs) play vital roles in the development and progression of various diseases. CircRNA coiled-coil domain containing 66 (circ-CCDC66) has been reported to be involved in several cancers, but its biological function and underlying mechanism in papillary thyroid carcinoma (PTC) remain unclear. We detected the relative expression level of circ-CCDC66 in PTC specimens and cell lines using real-time reverse transcription PCR. In addition, EdU assay, transwell assay, and xenograft analysis were performed to measure the effect of circ-CCDC66 on the proliferative, migratory, and invasive capacities of PTC cells. We also investigated the potential mechanism of circ-CCDC66 by bioinformatics analysis, RNA immunoprecipitation, and dual-luciferase reporter assay. We observed that circ-CCDC66 expression was upregulated in PTC specimens and cell lines and was correlated with poor clinical characteristics of PTC patients. Moreover, in vitro experiments demonstrated that knockdown of circ-CCDC66 markedly suppressed the proliferative, migratory, and invasive capacities of PTC cells. Mechanistically, miR-129-5p was a target gene of circ-CCDC66 and was downregulated in PTC tissues. LARP1, a downstream target of miR-129-5p, was upregulated in PTC tissues. In addition, we confirmed that inhibition of circ-CCDC66 could repress xenograft tumor growth. Circ-CCDC66 promoted PTC proliferation, migration, invasion, and tumor growth by sponging miR-129-5p and promoting LARP1 expression.