Hypoxic tumor-derived exosomal miR-4488 induces macrophage M2 polarization to promote liver metastasis of pancreatic neuroendocrine neoplasm through RTN3/FABP5 mediated fatty acid oxidation.

Tumor-associated macrophages (TAMs) represent a predominant cellular component within the tumor microenvironment (TME) of pancreatic neuroendocrine neoplasms (pNENs). There is a growing body of evidence highlighting the critical role of exosomes in facilitating communication between tumor cells and TAMs, thereby contributing to the establishment of the premetastatic niche. Nonetheless, the specific mechanisms through which exosomes derived from tumor cells influence macrophage polarization under hypoxic conditions in pNENs, and the manner in which these interactions support cancer metastasis, remain largely unexplored. Recognizing the capacity of exosomes to transfer miRNAs that can modify cellular behaviors, our research identified a significant overexpression of miR-4488 in exosomes derived from hypoxic pNEN cells. Furthermore, we observed that macrophages that absorbed circulating exosomal miR-4488 underwent M2-like polarization. Our investigations revealed that miR-4488 promotes M2-like polarization by directly targeting and suppressing RTN3 in macrophages. This suppression of RTN3 enhances fatty acid oxidation and activates the PI3K/AKT/mTOR signaling pathway through the interaction and downregulation of FABP5. Additionally, M2 polarized macrophages contribute to the formation of the premetastatic niche and advance pNENs metastasis by releasing MMP2, thereby establishing a positive feedback loop involving miR-4488, RTN3, FABP5, and MMP2 in pNEN cells. Together, these findings shed light on the role of exosomal miRNAs from hypoxic pNEN cells in mediating interactions between pNEN cells and intrahepatic macrophages, suggesting that miR-4488 holds potential as a valuable biomarker and therapeutic target for pNENs.

Small extracellular vesicle piR-hsa-30937 derived from pancreatic neuroendocrine neoplasms upregulates CD276 in macrophages to promote immune evasion.

The role of PIWI-interacting RNAs (piRNAs) in small extracellular vesicles (sEV) derived from pancreatic neuroendocrine neoplasms (PNEN) in the tumor microenvironment (TME) remains unexplored. We used multiplex immunohistochemistry (mIHC) to analyze the expression of CD68, CD276 (B7H3) and CD3 on PNEN. CD276+ tumor-associated macrophages (TAMs) were more abundant in tumor tissues than nontumor tissues and negatively correlated with T-cell infiltration. Serum sEV piRNA sequencing was performed to identify piRNAs enriched in PNEN patients. We then investigated the function and mechanism of sEV piR-hsa-30937 in the crosstalk between tumor cells and macrophages in the PNEN TME. PNEN-derived sEV piR-hsa-30937 targeted PTEN to activate the AKT pathway and drive CD276 expression. CD276+ macrophages inhibited T-cell proliferation and IFN- production. piR-hsa-30937 knockdown and anti-CD276 treatment suppressed progression and metastasis in a preclinical model of PNEN by enhancing T-cell immunity. Thus, our data show that PNEN-derived sEV piR-hsa-30937 promotes CD276 expression in macrophages through the PTEN/AKT pathway and that CD276+ TAMs suppress T-cell antitumor immunity. sEV piR-hsa-30937 and CD276 are potential therapeutic targets for immunotherapy of PNEN.

Hypoxia upregulating ACSS2 enhances lipid metabolism reprogramming through HMGCS1 mediated PI3K/AKT/mTOR pathway to promote the progression of pancreatic neuroendocrine neoplasms.

BACKGROUND: Pancreatic neuroendocrine neoplasms (pNENs) are relatively rare. Hypoxia and lipid metabolism-related gene acetyl-CoA synthetase 2 (ACSS2) is involved in tumor progression, but its role in pNENs is not revealed. This study showed that hypoxia can upregulate ACSS2, which plays an important role in the occurrence and development of pNENs through lipid metabolism reprogramming. However, the precise role and mechanisms of ACSS2 in pNENs remain unknown. METHODS: mRNA and protein levels of ACSS2 and 3-hydroxy-3-methylglutaryl-CoA synthase1 (HMGCS1) were detected using quantitative real-time PCR (qRT-PCR) and Western blotting (WB). The effects of ACSS2 and HMGCS1 on cell proliferation were examined using CCK-8, colony formation assay and EdU assay, and their effects on cell migration and invasion were examined using transwell assay. The interaction between ACSS2 and HMGCS1 was verified by Co-immunoprecipitation (Co-IP) experiments, and the functions of ACSS2 and HMGCS1 in vivo were determined by nude mouse xenografts. RESULTS: We demonstrated that hypoxia can upregulate ACSS2 while hypoxia also promoted the progression of pNENs. ACSS2 was significantly upregulated in pNENs, and overexpression of ACSS2 promoted the progression of pNENs and knockdown of ACSS2 and ACSS2 inhibitor (ACSS2i) treatment inhibited the progression of pNENs. ACSS2 regulated lipid reprogramming and the PI3K/AKT/mTOR pathway in pNENs, and ACSS2 regulated lipid metabolism reprogramming through the PI3K/AKT/mTOR pathway. Co-IP experiments indicated that HMGCS1 interacted with ACSS2 in pNENs. Overexpression of HMGCS1 can reverse the enhanced lipid metabolism reprogramming and tumor-promoting effects of knockdown of ACSS2. Moreover, overexpression of HMGCS1 reversed the inhibitory effect of knockdown of ACSS2 on the PI3K/AKT/mTOR pathway. CONCLUSION: Our study revealed that hypoxia can upregulate the lipid metabolism-related gene ACSS2, which plays a tumorigenic effect by regulating lipid metabolism through activating the PI3K/AKT/mTOR pathway. In addition, HMGCS1 can reverse the oncogenic effects of ACSS2, providing a new option for therapeutic strategy.

Bioinspired structural hydrogels with highly ordered hierarchical orientations by flow-induced alignment of nanofibrils.

Natural structural materials often possess unique combinations of strength and toughness resulting from their complex hierarchical assembly across multiple length scales. However, engineering such well-ordered structures in synthetic materials via a universal and scalable manner still poses a grand challenge. Herein, a simple yet versatile approach is proposed to design hierarchically structured hydrogels by flow-induced alignment of nanofibrils, without high time/energy consumption or cumbersome postprocessing. Highly aligned fibrous configuration and structural densification are successfully achieved in anisotropic hydrogels under ambient conditions, resulting in desired mechanical properties and damage-tolerant architectures, for example, strength of 14 ± 1 MPa, toughness of 154 ± 13 MJ m-3, and fracture energy of 153 ± 8 kJ m-2. Moreover, a hydrogel mesoporous framework can deliver ultra-fast and unidirectional water transport (maximum speed at 65.75 mm s-1), highlighting its potential for water purification. This scalable fabrication explores a promising strategy for developing bioinspired structural hydrogels, facilitating their practical applications in biomedical and engineering fields.

FOXA2-initiated transcriptional activation of INHBA induced by methylmalonic acid promotes pancreatic neuroendocrine neoplasm progression.

Pancreatic neuroendocrine neoplasms (PanNENs) are a group of highly heterogeneous neoplasms originating from the endocrine islet cells of the pancreas with characteristic neuroendocrine differentiation, more than 60% of which represent metastases when diagnosis, causing major tumor-related death. Metabolic alterations have been recognized as one of the hallmarks of tumor metastasis, providing attractive therapeutic targets. However, little is known about the molecular mechanism of metabolic changes regulating PanNEN progression. In this study, we first identified methylmalonic acid (MMA) as an oncometabolite for PanNEN progression, based on serum metabolomics of metastatic PanNEN compared with non-metastatic PanNEN patients. One of the key findings was the potentially novel mechanism of epithelial-mesenchymal transition (EMT) triggered by MMA. Inhibin ßA (INHBA) was characterized as a key regulator of MMA-induced PanNEN progression according to transcriptomic analysis, which has been validated in vitro and in vivo. Mechanistically, INHBA was activated by FOXA2, a neuroendocrine (NE) specific transcription factor, which was initiated during MMA-induced progression. In addition, MMA-induced INHBA upregulation activated downstream MITF to regulate EMT-related genes in PanNEN cells. Collectively, these data suggest that activation of INHBA via FOXA2 promotes MITF-mediated EMT during MMA inducing PanNEN progression, which puts forward a novel therapeutic target for PanNENs.

Serum Lipid Level in Evaluating Chinese Pancreatic Neuroendocrine Neoplasms: A Retrospective Study.

BACKGROUND: Pancreatic neuroendocrine neoplasms (p-NENs) are relatively rare and highly heterogeneous. Dyslipidemia may be related to the risk of developing p-NENs, although dyslipidemia in patients with p-NENs is rarely reported. In this study, the clinical characteristics of p-NENs patients with different lipid levels and their prognostic value in p-NENs patients were evaluated. METHODS: Patients (n=211) with p-NENs hospitalized at Jiangsu Neuroendocrine Tumor Centre of Jiangsu Province Hospital from December 2018 to December 2022 were enrolled. Clinical data related to p-NENs were collected. Based on the EGA database, the related lipoprotein, low-density lipoprotein receptor (LDLR) and high-density lipoprotein binding protein (HDLBP) mRNA in p-NENs and paratumoral tissues and the follow-up information of p-NENs were evaluated. RESULTS: A total of 175 p-NENs patients ultimately met the inclusion criteria. The ki67 index was higher in p-NENs patients with elevated lipid with the proportion of≥5, and in those with AJCC stage III and stage IV than p-NENs patients with low-level lipid. In p-NENs patients, the expression of HDLBP mRNA was downregulated in p-NENs tissues compared to the paratumoral tissues. Survival analysis showed that serum lipids had no effect on the prognosis of p-NENs; however, high LDLR level p-NENs were at the risk of poor survival. CONCLUSION: Serum lipid level in p-NENs can affect the grading and staging, but the correlation with the prognosis of p-NENs is not significant. However, dyslipidemia may be a potential predictor of p-NENs.

ALKBH5 enhances lipid metabolism reprogramming by increasing stability of FABP5 to promote pancreatic neuroendocrine neoplasms progression in an m6A-IGF2BP2-dependent manner.

The process of post-transcriptional regulation has been recognized to be significantly impacted by the presence of N6-methyladenosine (m6A) modification. As an m6A demethylase, ALKBH5 has been shown to contribute to the progression of different cancers by increasing expression of several oncogenes. Hence, a better understanding of the key targets of ALKBH5 in cancer cells could potentially lead to the development of new therapeutic targets. However, the specific role of ALKBH5 in pancreatic neuroendocrine neoplasms (pNENs) remains largely unknown. Here, we demonstrated that ALKBH5 was up-regulated in pNENs and played a critical role in tumor growth and lipid metabolism. Mechanistically, ALKBH5 over-expression was found to increase the expression of FABP5 in an m6A-IGF2BP2 dependent manner, leading to disorders in lipid metabolism. Additionally, ALKBH5 was found to activate PI3K/Akt/mTOR signaling pathway, resulting in enhanced lipid metabolism and proliferation abilities. In conclusion, our study uncovers the ALKBH5/IGF2BP2/FABP5/mTOR axis as a mechanism for aberrant m6A modification in lipid metabolism and highlights a new molecular basis for the development of therapeutic strategies for pNENs treatment.

Transcatheter arterial embolization in patients with neuroendocrine neoplasms related to liver metastasis with different blood supplies.

PURPOSE: Liver metastasis is one of the most important factors affecting the prognosis of patients with neuroendocrine neoplasms (NENs). Transhepatic artery embolization (TAE) is the main local treatment of NENs with liver metastasis (NENLM). This study aimed to elucidate the differences between pancreatic and rectal NENLM with a discrepancy in blood supply. METHODS: A total of 32 patients with NENLM of different primary sites received 102 TAE treatments at our hospital. Clinical features, such as age, sex, World Health Organization (WHO) tumour grade and progression-free survival (PFS), were compared between patients with pancreatic and rectal NENLM with different blood supplies. The total follow-up time is 1-5 years. RESULTS: There were 12 cases with tumours originating from the rectum or pancreas, respectively. Other tumour-originated sites included the duodenum (two cases, 6.25%), the thymus and lung (four cases, 12.5%), and the unknown (two cases, 6.25%). The average age of patients was 51.59 years, and 17 (53.1%) were men. WHO grade 1, 2 or 3 tumours occurred in three (9.4%), 23 (71.9%) and six (18.7%) patients, respectively. Hepatic tumour burdens of low (<25%), middle (25%-50%) and high (>50%) levels were found in 13 (40.6%), eight (25%) and 11 (34.4%) patients, respectively. There were more patients with hypervascular pancreatic NENLM than with hypovascular rectal NENLM (p = 0.005). Tumour shrinkage in all cases with NENLM was 50% with an objective response rate of 37.5%, disease control rate of 75% and PFS of 12 months. Disease progression (p = 0.09), tumour shrinkage (p = 0.07) and death (p = 0.19) were more prominent in the pancreatic NENLM group than in the rectal NENLM group. Progression-free survival was not reached in the pancreatic NENLM group, which was more prominent than in the rectal NENLM group (7 months; hazard ration, 0.22; 95% confidence interval, 0.07-0.76; p = 0.016). The main adverse events were abdominal pain (71.9%) and transaminase elevation (50%), which were more common in pancreatic NENLM than in rectal NENLM. CONCLUSIONS: Transhepatic artery embolization treatment is markedly effective and safe for treating NENLM, especially pancreatic NENLM.

Down-regulated FTO and ALKBH5 co-operatively activates FOXO signaling through m6A methylation modification in HK2 mRNA mediated by IGF2BP2 to enhance glycolysis in colorectal cancer.

BACKGROUND: N6-methyladenosine (m6A) modification is the most abundant reversible methylation modification in eukaryotes, and it is reportedly closely associated with a variety of cancers progression, including colorectal cancer (CRC). This study showed that activated lipid metabolism and glycolysis play vital roles in the occurrence and development of CRC. However, only a few studies have reported the biological mechanisms underlying this connection. METHODS: Protein and mRNA levels of FTO and ALKBH5 were measured using western blot and qRT-PCR. The effects of FTO and ALKBH5 on cell proliferation were examined using CCK-8, colony formation, and EdU assays, and the effects on cell migration and invasion were tested using a transwell assay. m6A RNA immunoprecipitation (MeRIP) and RNA-seq was used to explore downstream target gene. RIP was performed to verify the interaction between m6A and HK2. The function of FTO and ALKBH5 in vivo was determined by xenograft in nude mice. RESULTS: In this study, FTO and ALKBH5 were significantly down-regulated in CRC patients and cells both in vivo and in vitro in a high-fat environment. Moreover, FTO and ALKBH5 over-expression hampered cell proliferation both in vitro and in vivo. Conversely, FTO and ALKBH5 knockdown accelerated the malignant biological behaviors of CRC cells. The mechanism of action of FTO and ALKBH5 involves joint regulation of HK2, a key enzyme in glycolysis, which was identified by RNA sequencing and MeRIP-seq. Furthermore, reduced expression of FTO and ALKBH5 jointly activated the FOXO signaling pathway, which led to enhanced proliferation ability in CRC cells. IGF2BP2, as a m6A reader, positively regulated HK2 mRNA in m6A dependent manner. Additionally, down-regulation of FTO/ALKBH5 increased METTL3 and decreased METTL14 levels, further promoting CRC progression. CONCLUSION: In conclusion, our study revealed the FTO-ALKBH5/IGF2BP2/HK2/FOXO1 axis as a mechanism of aberrant m6A modification and glycolysis regulation in CRC.

FAM201A encodes small protein NBASP to inhibit neuroblastoma progression via inactivating MAPK pathway mediated by FABP5.

Increasing evidence indicates that long non-coding RNA (lncRNA) is one of the most important RNA regulators in the pathogenesis of neuroblastoma (NB). Here, we found that FAM201A was low expressed in NB and a variety of gain and loss of function studies elucidated the anti-tumor effects of FAM201A on the regulation of proliferation, migration and invasion of NB cells. Intriguingly, we identified the ability of FAM201A to encode the tumor-suppressing protein, NBASP, which interacted with FABP5 and negatively regulated its expression. In vivo assays also revealed NBASP repressed NB growth via inactivating MAPK pathway mediated by FABP5. In conclusion, our findings demonstrated that NBASP encoded by FAM201A played a tumor-suppressor role in NB carcinogenesis via down-regulating FABP5 to inactivate the MAPK pathway. These results extended our understanding of the relationship of lncRNA-encoded functional peptides and plasticity of tumor progression.

WTAP activates MAPK signaling through m6A methylation in VEGFA mRNA-mediated by YTHDC1 to promote colorectal cancer development.

N6-methyladenosine modification, especially Wilms tumor 1-associated protein (WTAP), is reportedly associated with a variety of cancers, including colorectal cancer (CRC). Angiogenesis also plays an important role in the occurrence and development of CRC. However, only a few studies have reported the biological mechanisms underlying this connection. Therefore, tissue microarray and public database were used to explore WTAP levels in CRC. Then, WTAP was down-regulated and over-expressed, respectively. CCK8, EdU, colony formation, and transwell experiments were performed to study the role of WTAP in CRC. Combined RNA sequencing and m6A RNA immunoprecipitation (MeRIP) sequencing, we found downstream molecules VEGFA. Moreover, a tube formation assay was executed for tumor angiogenesis. Finally, a subcutaneous tumorigenesis assay in nude mice was used to examine the tumor-promoting effect of WTAP in vivo. In the present study, WTAP was significantly upregulated in CRC cells and patients with CRC. Moreover, higher WTAP expression was observed in the TCGA and CPATC databases in CRC tissues. WTAP over-expression exacerbates cell proliferation, migration, invasion, and angiogenesis. Conversely, WTAP knockdown inhibited the malignant biological behavior of CRC cells. Mechanistically, WTAP positively regulated VEGFA, as identified using RNA sequencing and MeRIP sequencing. Moreover, we identified YTHDC1 as a downstream effector of the YTHDC1-VEGFA axis in CRC. Furthermore, increased WTAP expression activated the MAPK signaling pathway, which led to enhanced angiogenesis. In conclusion, our study revealed that the WTAP/YTHDC1/VEGFA axis promotes CRC development, especially angiogenesis, suggesting that it may act as a potential biomarker of CRC.

Methylmalonic acid promotes colorectal cancer progression via activation of Wnt/ß-catenin pathway mediated epithelial-mesenchymal transition.

BACKGROUND: It has been manifested in several studies that age-related metabolic reprogramming is associated with tumor progression, in particular, colorectal cancer (CRC). Here we investigated the role of upregulated metabolites of the aged serum, including methylmalonic acid (MMA), phosphoenolpyruvate (PEP), and quinolinate (QA), in CRC. METHODS: Functional assays including CCK-8, EdU, colony formation and transwell experiments were used to ascertain which upregulated metabolite of elderly serum was related to tumor progression. RNA-seq analysis was conducted to explore the potential mechanisms of MMA-induced CRC progression. Subcutaneous tumorigenesis and metastatic tumor models were constructed to verify the function of MMA in vivo. RESULTS: Among three consistently increased metabolites of the aged sera, MMA was responsible for tumorigenesis and metastasis in CRC, according to functional assays. The promotion of Epithelial-mesenchymal transition (EMT) was observed in CRC cells treated with MMA, on the basis of protein expression of EMT markers. Moreover, combined with transcriptome sequencing, Wnt/ß-catenin signaling pathway was activated in CRC cells treated with MMA, which was verified by western blot and qPCR experiments. Furthermore, animal assays demonstrated the pro-proliferation and promotion of metastasis role of MMA in vivo. CONCLUSION: We have identified that age-dependent upregulation of MMA in serum promoted the progression of CRC via Wnt/ß-catenin signaling pathway mediated EMT. These collective findings provide valuable insights into the vital role of age-related metabolic reprogramming in CRC progression and propose a potential therapeutic target for elderly CRC.

FABP5 suppresses colorectal cancer progression via mTOR-mediated autophagy by decreasing FASN expression.

Lipid metabolism plays an important role in the occurrence and development of cancer, in particular, digestive system tumors such as colon cancer. Here, we investigated the role of the fatty acid-binding protein 5 (FABP5) in colorectal cancer (CRC). We observed marked down-regulation of FABP5 in CRC. Data from functional assays revealed inhibitory effects of FABP5 on cell proliferation, colony formation, migration, invasion as well as tumor growth in vivo. In terms of mechanistic insights, FABP5 interacted with fatty acid synthase (FASN) and activated the ubiquitin proteasome pathway, leading to a decrease in FASN expression and lipid accumulation, moreover, suppressing mTOR signaling and facilitating cell autophagy. Orlistat, a FASN inhibitor, exerted anti-cancer effects both in vivo and in vitro. Furthermore, the upstream RNA demethylase ALKBH5 positively regulated FABP5 expression via an m6A-independent mechanism. Overall, our collective findings offer valuable insights into the critical role of the ALKBH5/FABP5/FASN/mTOR axis in tumor progression and uncover a potential mechanism linking lipid metabolism to development of CRC, providing novel therapeutic targets for future interventions.

Orlistat Induces Ferroptosis in Pancreatic Neuroendocrine Tumors by Inactivating the MAPK Pathway.

Background: Orlistat is an antiobesity drug approved by the US Food and Drug Administration (FDA) with potential antitumor activity against a few malignant tumors, however, whether orlistat affects the progression of pancreatic neuroendocrine tumors (pNETs) remains unknown. Methods: Protein and mRNA levels of FASN were measured using western blotting (WB) and qRT-PCR. The effects of FASN and orlistat on cell proliferation were examined using CCK-8, colony formation, and EdU assays. The effects of FASN and orlistat on cell migration and invasion were tested using a transwell assay. A lipid peroxidation assay was used to explore the effects of orlistat on ferroptosis. The function of orlistat in vivo was determined by xenograft in nude mice. Results: Based on the results of WB and qRT-PCR, FASN was significantly up-regulated in pNET cell lines and public database indicated increased expression of FASN correlated with poor prognosis for patients with pNET. CCK-8, colony formation, and EdU assays showed that knockdown of FASN or treatment with orlistat suppressed the proliferation of pNET cells. The transwell assay indicated that the knockdown of FASN or treatment with orlistat inhibited the migration and invasion of pNET cells. WB and the peroxidation assay showed that orlistat induced ferroptosis in pNET cells. Moreover, orlistat was also found to inhibit the MAPK pathway in pNETs. Furthermore, orlistat showed excellent anti-tumor effects in xenografts in nude mice. Conclusion: Altogether, our study demonstrates that orlistat inhibits the progression of pNETs by inducing ferroptosis mediated by inactivation of the MAPK signaling pathway. Therefore, orlistat is a promising candidate for the treatment of pNETs.

Efficacy and safety of modified endoscopic submucosal tunnel dissection for superficial esophageal circumferential lesions.

To evaluate the efficacy and safety of intra-tunnel dissection using hemostatic forceps and needle-type device for patients with esophageal circumferential lesions (ECLs). Patients with ECLs were enrolled in the study and underwent endoscopic submucosal tunnel dissection (ESTD) or hemostatic forceps-based ESTD (ESFTD). All patients were divided into three subgroups according to longitudinal length of the lesions (LLLs): >8 cm, 4-8 cm and < 4 cm. The clinical data such as gender, age, length of lesions and operating time were collected. A total of 152 patients were included in this study and comprised 80 cases of ESFTD and 72 cases of ESTD. The procedure time was markedly shorter in the ESFTD group than in the ESTD group (P < 0.001). Moreover, ESFTD significantly increased the rate of complete resection and reduced specimen injury in LLLs >8 cm and 4-8 cm subgroup compared with ESTD (P < 0.001), but not in <4 cm subgroup (P > 0.05). The perforation and infection rate were similar in ESFTD and ESTD group (P > 0.05). However, ESFTD effectively decreased the muscular injury rate' the duration of chest pain and the time from endoscopic surgery to first occurrence of esophageal stenosis compared with ESTD group (P < 0.01). ESFTD has better efficacy and safety than ESTD in the treatment of ECLs, especially for large lesions. ESFTD could be recommended for patients with ECLs.

FABP5 regulates lipid metabolism to facilitate pancreatic neuroendocrine neoplasms progression via FASN mediated Wnt/ß-catenin pathway.

Pancreatic neuroendocrine neoplasms (pNENs) are among the most frequently occurring neuroendocrine neoplasms (NENs) and require targeted therapy. High levels of fatty acid binding protein 5 (FABP5) are involved in tumor progression, but its role in pNENs remains unclear. We investigated the mRNA and protein levels of FABP5 in pNEN tissues and cell lines and found them to be upregulated. We evaluated changes in cell proliferation using CCK-8, colony formation, and 5-ethynyl-2'-deoxyuridine assays and examined the effects on cell migration and invasion using transwell assays. We found that knockdown of FABP5 suppressed the proliferation, migration, and invasion of pNEN cell lines, while overexpression of FABP5 had the opposite effect. Co-immunoprecipitation experiments were performed to clarify the interaction between FABP5 and fatty acid synthase (FASN). We further showed that FABP5 regulates the expression of FASN via the ubiquitin proteasome pathway and both proteins facilitate the progression of pNENs. Our study demonstrated that FABP5 acts as an oncogene by promoting lipid droplet deposition and activating the WNT/ß-catenin signaling pathway. Moreover, the carcinogenic effects of FABP5 can be reversed by orlistat, providing a novel therapeutic intervention option.

Novel insights into the interplay between m6A modification and programmed cell death in cancer.

N6-methyladenosine (m6A) methylation, the most prevalent and abundant RNA modification in eukaryotes, has recently become a hot research topic. Several studies have indicated that m6A modification is dysregulated during the progression of multiple diseases, especially in cancer development. Programmed cell death (PCD) is an active and orderly method of cell death in the development of organisms, including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis. As the study of PCD has become increasingly profound, accumulating evidence has revealed the mutual regulation of m6A modification and PCD, and their interaction can further influence the sensitivity of cancer treatment. In this review, we summarize the recent advances in m6A modification and PCD in terms of their interplay and potential mechanisms, as well as cancer therapeutic resistance. Our study provides promising insights and future directions for the examination and treatment of cancers.

ROS-responsive ADPH nanoparticles for image-guided surgery.

In recent years, organic fluorescent probes with tumor microenvironment (TME)-responsive fluorescence turn-on properties have been increasingly used in imaging-guided tumor resection due to their higher signal-to-noise ratio for tumor imaging compared to non-responsive fluorescent probes. However, although researchers have developed many organic fluorescent nanoprobes responsive to pH, GSH, and other TME, few probes that respond to high levels of reactive oxygen species (ROS) in the TME have been reported in imaging-guided surgery applications. In this work, we prepared Amplex® Red (ADHP) with excellent ROS response performance as an ROS-responsive nanoprobe and studied its application in image-guided tumor resection for the first time. To confirm whether the nanoprobe can be used as an effective biological indicator to distinguish tumor sites, we first detected 4T1 cells with the ADHP nanoprobe, demonstrating that the probe can utilize ROS in tumor cells for responsive real-time imaging. Furthermore, we conducted fluorescence imaging in vivo in 4T1 tumor-bearing mice, and the ADHP probe can rapidly oxidize to form resorufin in response to ROS, which can effectively reduce the background fluorescence signal compared with the single resorufin probe. Finally, we successfully carried out image-guided surgery of 4T1 abdominal tumors under the guidance of fluorescence signals. This work provides a new idea for developing more TME-responsive fluorescent probes and exploring their application in image-guided surgery.

Ferroptosis-induced anticancer effect of resveratrol with a biomimetic nano-delivery system in colorectal cancer treatment.

Ferroptosis is a novel form of programmed cell death impelled by iron-dependent lipid peroxidation, which may be a potential strategy for cancer therapy. Here we demonstrated for the first time that Resveratrol (RSV), a traditional Chinese medicine (TCM) chemical monomer, could effectually inhibit the growth of colon cancer cells through the ROS-dependent ferroptosis pathway. Mechanistically, RSV evoked the increase of reactive oxygen species and lipid peroxidation in colorectal cancer cells, and eventually lead to ferroptosis. Furthermore, RSV could promote ferroptosis by downregulating the expression of the channel protein solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4). To improve the delivery efficiency of RSV, a biomimetic nanocarrier was developed by coating RSV-loaded poly(ε-caprolactone)-poly(ethylene glycol) (PCL-PEG) nanoparticles with erythrocyte membrane (RSV-NPs@RBCm). The RSV-NPs@RBCm provide the possibility to escape macrophage phagocytosis and have a long circulation effect. In addition, when coupled with a tumor-penetrating peptide iRGD, which could trigger enhanced tissue penetration tumor-specifically, the delivery of RSV-NPs@RBCm into tumors would be significantly improved results from the in vivo study demonstrated an excellent treatment efficacy for CRC. Altogether, our study highlighted the therapeutic potential of RSV as a ferroptosis-inducing anticancer agent and when loaded into a biomimetic nanoplatform, it might pave the way for the application of RSV loaded nanosystems for colorectal cancer treatment.

A ferroptosis associated gene signature for predicting prognosis and immune responses in patients with colorectal carcinoma.

Background: Colorectal carcinoma (CRC) is one of the most prevalent malignancies globally. Ferroptosis, a novel type of cell death, is critical in the development and treatment of tumors. Objective: This study was designed to establish a genetic signature for ferroptosis which has a predictive effect on the outcomes and immunotherapeutic response of CRC. Methods: Data of CRC patients were retrieved from TCGA and GEO databases. The genes associated with ferroptosis were obtained from GeneCards. The genetic signature for ferroptosis was identified by performing Cox regression analysis. Kaplan-Meier and ROC analysis were performed to assess the prognosis role of the genetic signature. CIBERSORT tool was used to identify a potential association of the genetic signature with the immune cells. The potential immunotherapeutic signatures and drug sensitivity prediction targeting this signature were also discussed. Immunohistochemistry was used to detect expression of ferroptosis-associated genes in CRC tissues and adjacent tissues. Results: A ferroptosis-associated gene signature comprised of three genes (CDKN2A, FDFT1, and ACSL6) was developed for prediction of prognosis and evaluation of immune responses in CRC. Patients in the high-risk group tended to have a poor prognosis. In CRC, the ferroptosis-associated gene signature may function as independent predictors. Additionally, the expressional levels of the immune checkpoint proteins PD-L1 and CTLA-4 were substantially increased in the high-risk group. Moreover, we can distinguish between patients based on their immunotherapeutic responses more effectively if we categorize them by this signature. Additionally, candidate compounds were identified for the differentiation of CRC subtypes. Conclusion: The ferroptosis-associated gene signature identified in this study is effective in predicting the prognosis and evaluating immunotherapeutic response in CRC patients, and provides us with novel insights into the potential effect of ferroptosis targeted treatment on CRC.