IGF2BP3 drives gallbladder cancer progression by m6A-modified CLDN4 and inducing macrophage immunosuppressive polarization

Role, mechanism, and application of N6-methyladenosine in hepatobiliary carcinoma

Hepatobiliary carcinoma is a frequently occurring and highly invasive cancer within the digestive tract, known for its rapid progression. Due to its difficult diagnosis and treatment in clinical practice, hepatobiliary carcinoma is a serious threat to human life and health. In recent years, the incidence of hepatobiliary carcinoma has gradually increased. N6-methyladenosine (m6A) modification, as a reversible post-transcriptional modification of the adenosine N6 site, is one of the most important RNA modifications in eukaryotes. Emerging research indicates that m6A affects the biological process of cells through the regulation of gene expression. m6A modification also plays a key role in the occurrence and development of various cancers. This review summarizes the role and mechanism of m6A modification in hepatobiliary carcinoma, and discussed its potential clinical application, so as to provide a theoretical reference for the individualized treatment of hepatobiliary carcinoma.

FOXM1-activated IGF2BP3 promotes cell malignant phenotypes and M2 macrophage polarization in hepatocellular carcinoma by inhibiting ferroptosis via stabilizing RRM2 mRNA in an m6A-dependent manner

BACKGROUND

Ferroptosis has a crucial role in human carcinogenesis. N6-methyladenosine (m6A) reader insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) suppresses ferroptosis of hepatocellular carcinoma (HCC) cells. Here, we examined the effects and molecular determinants of IGF2BP3-mediated ferroptosis on malignant behaviors of HCC cells.

METHODS

Ferroptosis was evaluated by measuring the levels of malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), and lipid ROS. HCC cell malignant phenotypes were evaluated by colony formation assay, wound healing assay, and transwell invasion assay. The CD206+ M2-like macrophages were assessed by flow cytometry. m6A RNA immunoprecipitation (MeRIP) was applied to assess the m6A modification of ribonucleotide reductase regulatory subunit M2 (RRM2). RNA immunoprecipitation (RIP) assay was performed to evaluate the interaction of IGF2BP3 and RRM2. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were conducted to confirm the interaction between forkhead box M1 (FOXM1) and IGF2BP3.

RESULTS

Human HCC tumors showed increased expression of IGF2BP3 compared with adjacent normal tissues. Disruption of IGF2BP3 promoted cell ferroptosis. Moreover, disruption of IGF2BP3 hindered HCC cell growth, invasiveness, and motility and impeded THP1-derived macrophage M2 polarization and migration by inducing ferroptosis. Additionally, IGF2BP3 disruption repressed xenograft growth in vivo. Mechanistically, IGF2BP3 enhanced RRM2 mRNA stability and elevated its protein expression by reading its m6A modification. Overexpression of RRM2 reversed sh-IGF2BP3-mediated ferroptosis and weakened sh-IGF2BP3-mediated suppression of HCC cell malignant phenotypes and macrophage M2 polarization. Furthermore, IGF2BP3 was a downstream target of FOXM1, and knockdown of FOXM1 induced ferroptosis and inhibited cell malignant phenotypes by downregulating IGF2BP3.

CONCLUSION

FOXM1-induced IGF2BP3 upregulation promotes HCC cell malignant behaviors and macrophages M2 polarization by repressing ferroptosis via m6A-dependent regulation of RRM2 mRNA. Targeting FOXM1/IGF2BP3/RRM2 to enhance ferroptosis might be exploited as a potent therapeutic strategy for HCC.

Licochalcone A decreases cancer cell proliferation and enhances ferroptosis in acute myeloid leukemia through suppressing the IGF2BP3/MDM2 cascade

Licochalcone A (Lico A), a naturally bioactive flavonoid, has shown antitumor activity in several types of cancers. However, few studies have focused on its effect on acute myeloid leukemia (AML). Cell viability and colony formation potential were detected by CCK-8 assay and colony formation assay, respectively. Cell cycle distribution and apoptosis were assessed by flow cytometry. Ferroptosis was assessed by measuring reactive oxygen species (ROS), lipid ROS, malondialdehyde (MDA), and glutathione (GSH). Protein expression levels were determined by immunoblotting and immunohistochemistry (IHC), and mRNA expression was detected by real-time qPCR. The m6A modification of MDM2 mRNA was verified by methylated RNA immunoprecipitation (MeRIP) assay, and the interaction of IGF2BP3 and MDM2 mRNA was analyzed by RIP assay. Actinomycin D was used to evaluate mRNA stability. The efficacy of Lico A in vivo was examined by a murine xenograft model. Lico A suppressed cell proliferation and induced ferroptosis in MOLM-13 and U-937 in vitro, and slowed the growth of xenograft tumors in vivo. IGF2BP3 was highly expressed in human AML specimens and cells, and Lico A suppressed IGF2BP3 expression in AML cells. Lico A exerted the anti-proliferative and pro-ferroptosis effects by downregulating IGF2BP3. Moreover, IGF2BP3 enhanced the stability and expression of MDM2 mRNA through an m6A-dependent manner. Downregulation of IGF2BP3 impeded AML cell proliferation and enhanced ferroptosis via repressing MDM2. Furthermore, Lico A could affect the MDM2/p53 pathway by downregulating IGF2BP3 expression. Lico A exerts the anti-proliferative and pro-ferroptosis activity in AML cells by affecting the IGF2BP3/MDM2/p53 pathway, providing new evidence for Lico A as a promising agent for the treatment of AML.

Role of N6-methyladenosine RNA modification in cancer

N6-methyladenosine (m6A) is the most abundant modification of RNA in eukaryotic cells. Previous studies have shown that m6A is pivotal in diverse diseases especially cancer. m6A corelates with the initiation, progression, resistance, invasion, and metastasis of cancer. However, despite these insights, a comprehensive understanding of its specific roles and mechanisms within the complex landscape of cancer is still elusive. This review begins by outlining the key regulatory proteins of m6A modification and their posttranslational modifications (PTMs), as well as the role in chromatin accessibility and transcriptional activity within cancer cells. Additionally, it highlights that m6A modifications impact cancer progression by modulating programmed cell death mechanisms and affecting the tumor microenvironment through various cancer-associated immune cells. Furthermore, the review discusses how microorganisms can induce enduring epigenetic changes and oncogenic effect in microorganism-associated cancers by altering m6A modifications. Last, it delves into the role of m6A modification in cancer immunotherapy, encompassing RNA therapy, immune checkpoint blockade, cytokine therapy, adoptive cell transfer therapy, and direct targeting of m6A regulators. Overall, this review clarifies the multifaceted role of m6A modification in cancer and explores targeted therapies aimed at manipulating m6A modification, aiming to advance cancer research and improve patient outcomes.

The Role of m6A Methylation in Tumor Immunity and Immune-Associated Disorder

N6-methyladenosine (m6A) represents the most prevalent and significant internal modification in mRNA, with its critical role in gene expression regulation and cell fate determination increasingly recognized in recent research. The immune system, essential for defense against infections and maintaining internal stability through interactions with other bodily systems, is significantly influenced by m6A modification. This modification acts as a key post-transcriptional regulator of immune responses, though its effects on different immune cells vary across diseases. This review delineates the impact of m6A modification across major system-related cancers-including those of the respiratory, digestive, endocrine, nervous, urinary reproductive, musculoskeletal system malignancies, as well as acute myeloid leukemia and autoimmune diseases. We explore the pathogenic roles of m6A RNA modifications within the tumor immune microenvironment and the broader immune system, highlighting how RNA modification regulators interact with immune pathways during disease progression. Furthermore, we discuss how the expression patterns of these regulators can influence disease susceptibility to immunotherapy, facilitating the development of diagnostic and prognostic models and pioneering new therapeutic approaches. Overall, this review emphasizes the challenges and prospective directions of m6A-related immune regulation in various systemic diseases throughout the body.

Establishment and characterization of the gemcitabine-resistant human gallbladder cancer cell line NOZ GemR

BACKGROUND

Patients with gallbladder cancer (GBC) generally receive gemcitabine as the standard treatment; however, its efficacy is often limited owing to the development of resistance.

METHODS

To identify the mechanisms underlying gemcitabine resistance in GBC, a gemcitabine-resistant GBC cell line (NOZ GemR) was established by exposing the parental NOZ cell line to increasing concentrations of gemcitabine. Morphological changes, growth rates, and migratory and invasive capabilities were evaluated. Protein expression was detected using western blotting.

RESULTS

The results demonstrated that the IC50 of NOZ and NOZ GemR was 0.011 and 4.464 μM, respectively, and that the resistance index ratio was 405.8. In comparison, NOZ GemR cells grew slower and had significantly lower migration and invasion abilities than NOZ cells. There were altered levels of epithelial-mesenchymal transformation markers in NOZ GemR cells, as well as increased levels of the Akt/mTOR pathway protein.

CONCLUSION

The NOZ GemR cell line could be used as an effective in vitro model to improve our understanding of gemcitabine resistance in GBC.

New trends in diagnosis and management of gallbladder carcinoma

Gallbladder (GB) carcinoma, although relatively rare, is the most common biliary tree cholangiocarcinoma with aggressiveness and poor prognosis. It is closely associated with cholelithiasis and long-standing large (> 3 cm) gallstones in up to 90% of cases. The other main predisposing factors for GB carcinoma include molecular factors such as mutated genes, GB wall calcification (porcelain) or mainly mucosal microcalcifications, and GB polyps ≥ 1 cm in size. Diagnosis is made by ultrasound, computed tomography (CT), and, more precisely, magnetic resonance imaging (MRI). Preoperative staging is of great importance in decision-making regarding therapeutic management. Preoperative staging is based on MRI findings, the leading technique for liver metastasis imaging, enhanced three-phase CT angiography, or magnetic resonance angiography for major vessel assessment. It is also necessary to use positron emission tomography (PET)-CT or 18F-FDG PET-MRI to more accurately detect metastases and any other occult deposits with active metabolic uptake. Staging laparoscopy may detect dissemination not otherwise found in 20%-28.6% of cases. Multimodality treatment is needed, including surgical resection, targeted therapy by biological agents according to molecular testing gene mapping, chemotherapy, radiation therapy, and immunotherapy. It is of great importance to understand the updated guidelines and current treatment options. The extent of surgical intervention depends on the disease stage, ranging from simple cholecystectomy (T1a) to extended resections and including extended cholecystectomy (T1b), with wide lymph node resection in every case or IV-V segmentectomy (T2), hepatic trisegmentectomy or major hepatectomy accompanied by hepaticojejunostomy Roux-Y, and adjacent organ resection if necessary (T3). Laparoscopic or robotic surgery shows fewer postoperative complications and equivalent oncological outcomes when compared to open surgery, but much attention must be paid to avoiding injuries. In addition to surgery, novel targeted treatment along with immunotherapy and recent improvements in radiotherapy and chemotherapy (neoadjuvant-adjuvant capecitabine, cisplatin, gemcitabine) have yielded promising results even in inoperable cases calling for palliation (T4). Thus, individualized treatment must be applied.