CircRNA LOC729852 promotes bladder cancer progression by regulating macrophage polarization and recruitment via the miR-769-5p/IL-10 axis

CircRNAs in the tumor microenvironment: new frontiers in cancer progression and therapy

The tumor microenvironment (TME), a dynamic ecosystem which including immune cells, cancer-associated fibroblasts (CAFs), endothelial cells, pericytes and acellular components, is orchestrating cancer progression through crosstalk between malignant cells and stromal components and increasingly recognized as a therapeutic frontier. Within this intricate network, circular RNAs (circRNAs) have emerged as pivotal regulators due to their unique covalently closed structures, which confer exceptional stability and multifunctional capabilities. This regulation is mediated through multiple mechanisms, such as acting as microRNA (miRNA) sponges, interacting with proteins, and, in certain instances, encoding functional peptides. The interaction between circRNAs and the TME not only affects cancer growth and metastasis but also influences immune evasion and therapeutic resistance. Elucidating the mechanisms by which circRNAs orchestrate these interactions is essential for identifying novel diagnostic biomarkers and developing effective therapeutic strategies. Such insights are expected to bridge gaps in current cancer biology, offering promising avenues for precision oncology and ultimately improving clinical outcomes for cancer patients.

Circular RNAs: driving forces behind chemoresistance and immune evasion in bladder cancer

Bladder cancer (BCa) is characterized by recurring relapses and the emergence of chemoresistance, especially against standard treatments like cisplatin and gemcitabine. Despite its significance, the molecular mechanisms underlying chemoresistance in BCa remain elusive. Recent studies have revealed that circular RNAs (circRNAs) are pivotal regulators of cancer progression and chemoresistance. Through their function as miRNA sponges and protein sequesters, circRNAs modulate the expression of key genes, ultimately driving either drug resistance or sensitivity in BCa. The complex interplay between circRNAs and chemoresistance suggests that they may represent promising therapeutic targets for overcoming treatment resistance in patients with BCa. This review aims to summarize the current understanding of circRNAs' regulatory roles in chemoresistance and provide insights into their potential as therapeutic targets, particularly in the context of cisplatin and gemcitabine resistance. Furthermore, we explore how chemoresistance can also impact tumor immune evasion, thereby affecting the tumor microenvironment. Our findings may pave the way for the advancement of innovative treatment approaches for bladder cancer.

Recent animal models of bladder cancer and their application in drug discovery: an update of the literature

INTRODUCTION

Bladder cancer presents a significant health problem worldwide, with environmental and genetic factors contributing to its incidence. Histologically, it can be classified as carcinoma in situ, non-muscle invasive and muscle-invasive carcinoma, each one with distinct genetic alterations impacting prognosis and response to therapy. While traditional transurethral resection is commonly performed in carcinoma in situ and non-muscle invasive carcinoma, it often fails to prevent recurrence or progression to more aggressive phenotypes, leading to the frequent need for additional treatment such as intravesical chemotherapy or immunotherapy. Despite the advances made in recent years, treatment options for bladder cancer are still lacking due to the complex nature of this disease. So, animal models may hold potential for addressing these limitations, because they not only allow the study of disease progression but also the evaluation of therapies and the investigation of drug repositioning.

AREAS COVERED

This review discusses the use of animal models over the past decade, highlighting key discoveries and discussing advantages and disadvantages for new drug discovery.

EXPERT OPINION

Over the past decade animal models have been employed to evaluate new mechanisms underlying the responses to standard therapies, aiming to optimize bladder cancer treatment. The authors propose that molecular engineering techniques and AI may hold promise for the future development of more precise and effective targeted therapies in bladder cancer.

Circular RNA circ_0061183 regulates microglial polarization induced by airborne ultrafine particles in HMC3 cells via sponging miR-98-5p

Airborne ultrafine particulate matter (PM0.1) can enter the brain, induce microglia activation, and promote the development of Alzheimer's disease (AD). Circular RNAs (circRNAs) are also involved in AD pathogenesis. However, the role of AD-related circRNAs in PM0.1-induced microglia activation remains unclear. Therefore, we explore cytotoxicity, microglia activation, and AD-associated circRNA expression in human microglial HMC3 cells treated with PM0.1, and further examined circRNA expression in mice and cognitively impaired individuals. The results revealed that PM0.1 exposure decreased cell viability, increased lactate dehydrogenase activity, caused microglia activation, elevated microglial M1 maker expression, downregulated microglial M2 maker expression, and reduced AD-related circ_0061183 expression in vitro. Functionally, circ_0061183 silencing enhanced microglia activation and microglial M1 polarization, but inhibited microglial M2 polarization. Mechanistically, circ_0061183 can bind to miR-98-5p to co-regulate M2 microglial-related IL10 expression, which may affect transforming growth factor-β signaling to regulate PM0.1-inhibited microglial M2 polarization. Moreover, circ_0061183 downregulation was observed in the brain of PM2.5-exposed mice and AD mice and in the blood of cognitively impaired individuals. Furthermore, circ_0061183 was positively related to mini-mental state examination scores and amyloid-β42 peptide expression in elderly individuals. Overall, the current work offers epigenetic insights into the regulatory mechanisms of circRNAs on microglial activation caused by environmental pollutants.

Exosomal circRNAs: Deciphering the novel drug resistance roles in cancer therapy

Exosomal circular RNA (circRNAs) are pivotal in cancer biology, and tumor pathophysiology. These stable, non-coding RNAs encapsulated in exosomes participated in cancer progression, tumor growth, metastasis, drug sensitivity and the tumor microenvironment (TME). Their presence in bodily fluids positions them as potential non-invasive biomarkers, revealing the molecular dynamics of cancers. Research in exosomal circRNAs is reshaping our understanding of neoplastic intercellular communication. Exploiting the natural properties of exosomes for targeted drug delivery and disrupting circRNA-mediated pro-tumorigenic signaling can develop new treatment modalities. Therefore, ongoing exploration of exosomal circRNAs in cancer research is poised to revolutionize clinical management of cancer. This emerging field offers hope for significant breakthroughs in cancer care. This review underscores the critical role of exosomal circRNAs in cancer biology and drug resistance, highlighting their potential as non-invasive biomarkers and therapeutic targets that could transform the clinical management of cancer.

Non-coding RNAs in bladder cancer, a bridge between gut microbiota and host?

In recent years, the role of gut microbiota (GM) in bladder cancer has attracted significant attention. Research indicates that GM not only contributes to bladder carcinogenesis but also influences the efficacy of adjuvant therapies for bladder cancer. Despite this, interventions targeting GM have not been widely employed in the prevention and treatment of bladder cancer, mainly due to the incomplete understanding of the complex interactions between the host and gut flora. Simultaneously, aberrantly expressed non-coding RNAs (ncRNAs) have been frequently associated with bladder cancer, playing crucial roles in processes such as cell proliferation, invasion, and drug resistance. It is widely known that the regulation of GM-mediated host pathophysiological processes is partly regulated through epigenetic pathways. At the same time, ncRNAs are increasingly regarded as GM signaling molecules involved in GM-mediated epigenetic regulation. Accordingly, this review analyzes the ncRNAs that are closely related to the GM in the context of bladder cancer occurrence and treatment, and summarizes the role of their interaction with the GM in bladder cancer-related phenotypes. The aim is to delineate a regulatory network between GM and ncRNAs and provide a new perspective for the study and prevention of bladder cancer.

Targeting autophagy in urological system cancers: From underlying mechanisms to therapeutic implications

The urological system, including kidneys, ureters, bladder, urethra and prostate is known to be vital for blood filtration, waste elimination and electrolyte balance. Notably, urological system cancers represent a significant portion of global cancer diagnoses and mortalities. The current therapeutic strategies for early-stage cancer primarily involve resection surgery, which significantly affects the quality of life of patients, whereas advanced-stage cancer often relies on less effective chemo- or radiotherapy. Recently, accumulating evidence has revealed that autophagy, a crucial process in which excess organelles or inclusions within cells are removed to maintain cell homeostasis, has numerous links to urological system cancers. In this review, we focus on summarizing the underlying two-sided mechanisms of autophagy in urological system cancers. We also review the current clinical drugs targeting autophagy, which demonstrate significant potential in improving treatment outcomes for urological system cancers. In addition, we provide an overview of the research status of novel small molecule compounds targeting autophagy that are in the preclinical stages of investigation. Furthermore, drug combinations based on autophagy modulation strategies in urological system cancers are systematically summarized and discussed. These findings provide comprehensive new insight for the future discovery of more autophagy-related drug candidates.

Increased infiltration of M2-polarized tumour-associated macrophages is highly associated with advanced disease stage and high expression of PD-L1 in buccal mucosa carcinoma

OBJECTIVE

To assess the infiltration characteristics of tumour-associated macrophages (TAMs) in buccal mucosa carcinoma (BMC) and the correlation of these features with clinicopathological factors.

MATERIALS AND METHODS

Immunohistochemistry was used to detect the expression of TAM-related markers (CD68, CD163, CD206), CD8+ T cell markers, PD-L1, and epidermal growth factor receptor (EGFR) in 46 patients with mucosal cancer after radical surgery. In addition, the correlation between TAM infiltration and clinical characteristics, PD-L1 expression, and EGFR expression was analysed.

RESULTS

A high infiltration level of M2-polarized (CD206+) TAMs and M2-polarized (CD163+) TAMs was more common in stage T3-T4, N+, III-IV patients than in other patient groups (P < 0.05). The infiltration degree of M2-polarized (CD68+) TAMs was positively correlated with the PD-L1 TPS (P = 0.0331). The infiltration level of M2-polarized (CD206+) TAMs was higher in the EGFR high expression group than in the EGFR low expression group (P = 0.040).

CONCLUSION

High infiltration of M2-polarized TAMs is highly associated with advanced disease stage and higher expression of PD-L1 and EGFR in BMCs, suggesting that M2-polarized TAMs infiltration can serve as a potential therapeutic target.

Non-Coding RNA-Targeted Therapy: A State-of-the-Art Review

The use of non-coding RNAs (ncRNAs) as drug targets is being researched due to their discovery and their role in disease. Targeting ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), is an attractive approach for treating various diseases, such as cardiovascular disease and cancer. This seminar discusses the current status of ncRNAs as therapeutic targets in different pathological conditions. Regarding miRNA-based drugs, this approach has made significant progress in preclinical and clinical testing for cardiovascular diseases, where the limitations of conventional pharmacotherapy are evident. The challenges of miRNA-based drugs, including specificity, delivery, and tolerability, will be discussed. New approaches to improve their success will be explored. Furthermore, it extensively discusses the potential development of targeted therapies for cardiovascular disease. Finally, this document reports on the recent advances in identifying and characterizing microRNAs, manipulating them, and translating them into clinical applications. It also addresses the challenges and perspectives towards clinical application.