Pancreatic Cancer Metastasis Research Articles

Mechanisms of ginseng in pancreatic cancer metastasis

It has been shown that ginsenosides can inhibit proliferation, migration, and invasion of pancreatic cancer (PC) cells, and promote apoptosis of PC cells. However, the potential mechanisms of ginseng in treating PC metastasis (PCM) have not been fully elucidated. In this study, we employed an integrated bioinformatics approach of network pharmacology analysis. By selecting common targets of diseases and drugs, a drug-component-target-disease network was constructed to analyze the biological functions and signaling pathways involved in the targets. A total of 6 PC samples were includedd, which were divided into primary PC group (PANC-1, n=3) and metastatic PC group. A total of 9263 differentially expressed genes (DEGs) and 14 PC target genes were identified. According to the network pharmacology analysis, we found that ginsenoside Rg3 was associated with the treatment of PCM and identified 6 potential targets. Among them, CD44, EGFR, KRAS, and PRNP were the main DEGs related to the treatment of PC by ginsenoside Rg3. These genes were mainly enriched in the Proteoglycans in Cancer pathway, and KRAS, EGFR, and CD44 were upregulated in the pathway, which may be affected by the ginsenoside Rg3. This provides a new direction for further research on the mechanisms of ginseng in PCM.

Mechanisms of ginseng in pancreatic cancer metastasis

It has been shown that ginsenosides can inhibit proliferation, migration, and invasion of pancreatic cancer (PC) cells, and promote apoptosis of PC cells. However, the potential mechanisms of ginseng in treating PC metastasis (PCM) have not been fully elucidated. In this study, we employed an integrated bioinformatics approach of network pharmacology analysis. By selecting common targets of diseases and drugs, a drug-component-target-disease network was constructed to analyze the biological functions and signaling pathways involved in the targets. A total of 6 PC samples were includedd, which were divided into primary PC group (PANC-1, n=3) and metastatic PC group. A total of 9263 differentially expressed genes (DEGs) and 14 PC target genes were identified. According to the network pharmacology analysis, we found that ginsenoside Rg3 was associated with the treatment of PCM and identified 6 potential targets. Among them, CD44, EGFR, KRAS, and PRNP were the main DEGs related to the treatment of PC by ginsenoside Rg3. These genes were mainly enriched in the Proteoglycans in Cancer pathway, and KRAS, EGFR, and CD44 were upregulated in the pathway, which may be affected by the ginsenoside Rg3. This provides a new direction for further research on the mechanisms of ginseng in PCM.

Liver metastasis composed of pure squamous cell carcinoma component from pancreatic pure ductal adenocarcinoma: a case report

BackgroundLiver metastasis of pure squamous cell carcinoma (SCC) from pancreatic ductal adenocarcinoma has not been previously reported.Case presentationA 66-year-old man underwent a computed tomography scan 3 years after surgery for pancreatic head cancer, and the scan revealed a mass lesion in the right lobe of the liver. A liver tumor biopsy was performed, and SCC was diagnosed. Whole sections of the pancreatic head cancer were re-evaluated, but no areas of SCC-like differentiation were identified. Although the pathology differed between the pancreas and liver, metastasis of adenosquamous carcinoma was considered. Three courses of gemcitabine plus nab-paclitaxel were administered to treat the liver metastasis of pancreatic cancer, but no response was attained. Therefore, primary SCC of the liver was considered and hepatic resection was performed. The tumor had invaded the diaphragm, and S5/6 partial hepatic resection with right diaphragm resection was performed. Pathological examination showed pure SCC of the liver, which differed from the pancreatic cancer. KRAS mutations were evaluated in the pancreatic and liver tumor specimens, and Q61R mutation was identified in both specimens. This pure SCC of the liver was diagnosed as metastasis from pancreatic cancer not by histology but by genetic analysis.ConclusionsThis is the first reported case of pure SCC liver metastasis from pancreatic cancer without a squamous cell component in the primary tumor. Evaluation of KRAS mutations in both specimens was useful for diagnosis.

S100A2 induces epithelial–mesenchymal transition and metastasis in pancreatic cancer by coordinating transforming growth factor β signaling in SMAD4-dependent manner

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor and is associated with a poor prognosis. Treatment strategies for PDAC are largely ineffective primarily because of delay in its diagnosis and limited efficacy of systematic treatment. S100A2 is associated with the proliferation, migration, and differentiation of several tumors; however, its effects on PDAC and the associated molecular mechanisms remain to be explored. We studied the mechanisms underlying the effect of S100A2 on epithelial–mesenchymal transition (EMT) and metastasis in PDAC cells. We found that the level of S100A2 remarkably increased and was associated with poor PDAC prognosis. The overexpression of S100A2 in PANC-1 cells also induced EMT, in addition to increasing the invasion and migration of PDAC cells, whereas the knockdown of S100A2 markedly inhibited cell metastasis. Furthermore, S100A2 was found to enhance metastatic abilities in vivo. The overexpression of S100A2 increased SMAD4 expression, whereas the knockdown of S100A2 reduced SMAD4 expression. SMAD4 overexpression could effectively rescue the effects of S100A2 knockdown on EMT. S100A2 mechanistically activated the transforming growth factor (TGF)-β/Smad2/3 signaling pathway, upregulated SMAD4 expression, induced EMT, and increased PANC-1 cell metastasis. In conclusion, the S100A2/SMAD4 axis modulates EMT to accelerate PDAC development. Our results supplement and enrich the understanding of the pathogenesis underlying PDAC and provide a new theoretical basis and strategy targeting S100A2 for the diagnosis and treatment of PDAC.

Heterogeneity analysis of pancreatic cancer and identification of molecular subtypes of tumor cells based on CEACAM5, LGALS1 and CENPF gene expression

To explore the heterogeneity of pancreatic cancer and new methods for tumor cell molecular subtyping and identify the signature genes in pancreatic cancer progression. Based on the single-cell sequencing data of 16 pancreatic cancer tissues from the GSE155698 dataset, the single pancreatic cancer cells were classified according to EPCAM gene expression after preliminary clustering, re-clustering, and subgrouping to identify the signature genes, followed by pathway enrichment analysis and pseudo-time analysis. The key genes identified were validated using the clinical and tissue gene and protein expression data from 179 pancreatic cancer patients and 171 healthy controls. The impact of CEACAM5, LGALS1, and CENPF on proliferation, migration and invasion of pancreatic cancer cells were analyzed. Analysis of 48 570 cells from 16 pancreatic cancer samples revealed a total of 22 clusters, including 5 clusters of pancreatic cancer cells, which were classified into Subtype 1, Subtype 2, and Subtype 3, each exhibiting distinct gene expression patterns and functions. The signature genes were enriched in negatively regulated protein metabolic processes, ferroptosis, and antigen processing and presentation-related pathways in Subtype 1 pancreatic cancer cells; in peptide synthesis processes, translation, and ribosome-related pathways in Subtype 2; and in ATP metabolic processes, glycolysis/gluconeogenesis, and cell cyclerelated pathways in Subtype 3. Subtypes 2 and 3 were potentially derived from Subtype 1, and Subtype 3 possibly represented the final developmental stage of pancreatic cancer cells. The key signature genes (CEACAM5, LGALS1, and CENPF) also exhibited different expression patterns in the developmental trajectory and showed high expressions in pancreatic cancer in association with poor prognoses. In pancreatic cancer cells, downregulation of CEACAM5, LGALS1, and CENPF significantly inhibited the proliferation, migration, and invasion abilities of the cells (P<0.05). Pancreatic cancer cells exhibit significant heterogeneity, and CEACAM5, LGALS1, and CENPF gene expressions, which affect pancreatic cancer cell proliferation, invasion, and metastasis, can be used to identify distinct molecular subtypes during tumor cell development.

A Long-Term and Sustainable Response to Orapali in a BRCA2 Mutant Advanced Pancreatic Cancer: A Case Report

Pancreatic cancer is a highly malignant cancer characterized by high mutation rates of oncogenes and tumor suppressor genes and genomic instability. It has a poor prognosis owing to early metastasis and rapid growth. Therefore, new drugs or treatments are urgent to be required. Poly ADP-Ribose polymerase (PARP) inhibitors have shown therapeutic efficacy in pancreatic cancer driven by defects in homologous recombinant (HRD). Here we report a case of advanced pancreatic cancer with BRCA2 mutation. The patient came to our hospital due to abnormal enlargement of the left supraclavicular lymph node. Further examination revealed pancreatic cancer with multiple retroperitoneal lymph nodes metastases and lung metastases. Pathological and immunohistochemical results of supraclavicular lymph node confirmed it was pancreatic cancer metastasis. Next generation sequencing (NGS) demonstrated that BRCA2 germline mutation. Subsequently, gemcitabine combined with cisplatin as first line therapy was commenced for the patient. The tumors were significant reduced after 6 cycles of treatment. Then, the patient was given orapali (PARP inhibitors) to maintain treatment. Surprisingly, the efficacy has lasted for about 20 months (from Dec 2021 to Aug 2023) and no signs of disease progression have been found. Our case shows that orapali provides a more efficient and low-toxic treatment for patient with BRCA2 mutation advanced pancreatic cancer, which is expected to change the treatment pattern of advanced pancreatic cancer.

Advancement of single-cell sequencing for clinical diagnosis and treatment of pancreatic cancer.

Single-cell sequencing is a high-throughput technique that enables detection of genomic, transcriptomic, and epigenomic information at the individual cell level, offering significant advantages in detecting cellular heterogeneity, precise cell classification, and identifying rare subpopulations. The technique holds tremendous potential in improving the diagnosis and treatment of pancreatic cancer. Moreover, single-cell sequencing provides unique insights into the mechanisms of pancreatic cancer metastasis and cachexia, paving the way for developing novel preventive strategies. Overall, single-cell sequencing has immense potential in promoting early diagnosis, guiding personalized treatment, and preventing complications of pancreatic cancer. Emerging single-cell sequencing technologies will undoubtedly enhance our understanding of the complex biology of pancreatic cancer and pave the way for new directions in its clinical diagnosis and treatment.

MiR-33a-3p regulates METTL3-mediated AREG stability and alters EMT to inhibit pancreatic cancer invasion and metastasis

Recent studies have shown that amphoteric regulatory protein (AREG), a member of the epidermal growth factor (EGF) family, is expressed in many cancers and is an independent prognostic indicator for patients with pancreatic cancer, but whether AREG is regulated at the epigenetic level to promote the development of pancreatic cancer (PC) has not been elucidated. Our results support the notion that AREG is overexpressed in pancreatic cancer tissues and cell lines. Functionally, the deletion of AREG impedes pancreatic cancer (PC) cell proliferation, migration, and invasion. In addition, we identified and validated that methyltransferase-like 3 (METTL3) induced the m6A modification on AREG and facilitated the stability of AREG mRNA after sequencing. Additionally, we obtained experimental evidence that miR-33a-3p targets and inhibits METTL3 from taking action, as predicted by using the miRDB and RNAinter. Remediation experiments showed that miR-33a-3p inhibits PC progression through METTL3. In summary, this research reveals that miR-33a-3p inhibits m6A-induced stabilization of AREG by targeting METTL3, which plays a key role in the aggressive progression of PC. AREG could be a potential target for PC treatment.

Multi-targeting liposomal codelivery of cisplatin and rapamycin inhibits pancreatic cancer growth and metastasis through stromal modulation

Pancreatic cancer treatment faces challenges due to drug resistance as well as liver metastasis. As a new strategy for treating pancreatic cancer, combination therapy is now available, but the dense mesenchymal barrier in the tumor tissue blocks drug delivery and impairs its therapeutic efficacy. To address this issue, we prepared an ATF peptide-decorated liposomal co-loaded with cisplatin and rapamycin (ATF@Pt/Rapa Lps), which targets both tumor cells and cancer-associated fibroblasts that express uPAR receptors. In tumor sphere penetration experiments, ATF peptide modified liposomes significantly enhanced deep penetration. More importantly, the ATF@Pt/Rapa Lps disrupted the stroma, as demonstrated by the downregulation of ɑ-SMA, I collagen, and fibronectin protein in vivo and in vitro. In this way, highly effective drug delivery to tumor cells can be achieved. As expected, there was a stronger inhibition of cell proliferation and migration by ATF@Pt/Rapa Lps in vitro compared to free Pt/Rapa and Pt/Rapa Lps. Furthermore, ATF@Pt/Rapa Lps showed greater therapeutic effects in PANC02 transplanted tumor mice and liver metastasis mice models. Ultimately, multi-targeting nanomedicines co-loaded with Rapa and cisplatin may provide a new approach to treating metastatic pancreatic cancer.

MRI with DWI improves detection of liver metastasis and selection of surgical candidates with pancreatic cancer: a systematic review and meta-analysis.

To perform a systematic review and meta-analysis to evaluate if magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI) adds value compared to contrast-enhanced computed tomography (CECT) alone in the preoperative evaluation of pancreatic cancer. MEDLINE, EMBASE, and Cochrane databases were searched for relevant published studies through October 2022. Studies met eligibility criteria if they evaluated the per-patient diagnostic performance of MRI with DWI in the preoperative evaluation of newly diagnosed pancreatic cancer compared to CECT. Our primary outcome was the number needed to treat (NNT) to prevent one futile surgery using MRI with DWI, defined as those in which CECT was negative and MRI with DWI was positive for liver metastasis (i.e., surgical intervention in metastatic disease missed by CECT). The secondary outcomes were to determine the diagnostic performance and the NNT of MRI with DWI to change management in pancreatic cancer. Nine studies met the inclusion criteria with a total of 1121 patients, of whom 172 had liver metastasis (15.3%). The proportion of futile surgeries reduced by MRI with DWI was 6.0% (95% CI, 3.0-11.6%), yielding an NNT of 16.6. The proportion of cases that MRI with DWI changed management was 18.1% (95% CI, 9.9-30.7), corresponding to an NNT of 5.5. The per-patient sensitivity and specificity of MRI were 92.4% (95% CI, 87.4-95.6%) and 97.3% (95% CI, 96.0-98.1). MRI with DWI may prevent futile surgeries in pancreatic cancer by improving the detection of occult liver metastasis on preoperative CECT with an NNT of 16.6. MRI with DWI complements the standard preoperative CECT evaluation for liver metastasis in pancreatic cancer, improving the selection of surgical candidates and preventing unnecessary surgeries. • The NNT of MRI with DWI to prevent potential futile surgeries due to occult liver metastasis on CECT, defined as those in which CECT was negative and MRI with DWI was positive for liver metastasis, in patients with pancreatic cancer was 16.6. • The higher performance of MRI with DWI to detect liver metastasis occult on CECT can be attributed to an increased detection of subcentimeter liver metastasis.

Hypoxia induces immunosuppression, metastasis and drug resistance in pancreatic cancers

Pancreatic cancer is one of the common malignant tumors of the digestive system and is known as the “king of cancers”. It is extremely difficult to diagnose at an early stage, the disease progresses rapidly, and the effect of chemotherapy and radiotherapy is poor, so the prognosis of pancreatic cancer patients is very poor. Numerous studies have suggested that hypoxia is closely related to the development and progression of pancreatic cancer. Inadequate blood supply and desmoplasia in the microenvironment of pancreatic cancer can result in its extreme hypoxia. This hypoxic microenvironment can further contribute to angiogenesis and desmoplasia. Hypoxia is mediated by the complex hypoxia inducible factor (HIF) signaling pathway and plays an important role in the formation of a highly immunosuppressive microenvironment and the metastasis of pancreatic cancer. Further work on the hypoxic microenvironment will help clarify the specific mechanisms of the role of hypoxia in pancreatic cancer and provide a basis for the realization of hypoxia-targeted therapeutic and diagnostic strategies.

The ALOX5 inhibitor Zileuton regulates tumor-associated macrophage M2 polarization by JAK/STAT and inhibits pancreatic cancer invasion and metastasis.

5-lipoxygenase (encoded by ALOX5) plays an important role in immune regulation. Zileuton is currently the only approved ALOX5 inhibitor. However, the mechanisms of ALOX5 and Zileuton in progression of pancreatic cancer remain unclear. Therefore, we investigated the effects of Zileuton on tumor-associated macrophage M2 polarization and pancreatic cancer invasion and metastasis, both in vivo and in vitro. In bulk RNA sequencing (RNA-seq) and single-cell RNA sequencing (scRNA-seq) analyses, we found a significant association between elevated levels of ALOX5 and poor survival, adverse stages, M2 macrophage infiltration, and the activation of JAK/STAT pathways in macrophages. In clinical samples, immunofluorescence, quantitative real-time PCR and immunohistochemical results verified the high expression of ALOX5 in pancreatic cancer, primarily in macrophages. We constructed PANC-1 human pancreatic cancer cells and macrophages overexpressing ALOX5 using lentivirus. In PANC-1 pancreatic cancer cells, low-dose Zileuton inhibited PANC-1 cell invasion and migration by blocking ALOX5. In macrophages, ALOX5 induced the M2-like phenotype through the JAK/STAT pathway and promoted the chemotaxis of macrophages towards PANC-1 cells, while Zileuton can inhibit these effects. We constructed the nude mouse model of in situ transplantation tumor of pancreatic cancer. After treatment with Zileuton, the mice showed increased survival rates and reduced liver metastasis. These findings indicate that ALOX5 regulates tumor-associated macrophage M2 polarization via the JAK/STAT pathway and promotes invasion and metastasis in pancreatic cancer. Zileuton can inhibit these effects by inhibiting ALOX5. These results provide a theoretical basis for the potential use of Zileuton in the treatment of pancreatic cancer.

Metabolic stress-induced reciprocal loop of long noncoding RNA ZFAS1 and ZEB1 promotes epithelial-mesenchymal transition and metastasis of pancreatic cancer cells.

Pancreatic cancer (PC) development faces significant metabolic stress due to metabolic reprogramming and a distinct hypovascular nature, often leading to glucose and glutamine depletion. However, the adaption mechanisms by which PC adapts to these metabolic challenges have not yet been completely explored. Here, we found that metabolic stress induced by glucose and glutamine deprivation led to an overexpression of ZNFX1 antisense RNA 1 (ZFAS1). This overexpression played a significant role in instigating PC cell epithelial-mesenchymal transition (EMT) and metastasis. Mechanistically, ZFAS1 enhanced the interaction between AMPK, a key kinase, and ZEB1, the primary regulator of EMT. This interaction resulted in the phosphorylation and subsequent stabilization of ZEB1. Interestingly, ZEB1 also reciprocally influenced the transcription of ZFAS1 by binding to its promoter. Furthermore, when ZFAS1 was depleted, the nutrient deprivation-induced EMT of PC cells and lung metastasis in nude mice were significantly inhibited. Our investigations also revealed that ZFAS1-rich exosomes released from cells suffering glucose and glutamine deprivation promoted the EMT and metastasis of recipient PC cells. Corroborating these findings, a correlated upregulation of ZFAS1 and ZEB1 expression was observed in PC tissues and was associated with a poor overall survival rate for patients. Our findings highlight the involvement of a long noncoding RNA-driven metabolic adaptation in promoting EMT and metastasis of PC, suggesting ZFAS1 as a promising novel therapeutic target for PC metabolic treatment.

Knockdown of NF-κB activating protein promotes pancreatic cancer growth and metastasis through mTOR signaling pathway.

NF-κB activating protein (NKAP) acts as a transcriptional suppressor in the Notch signaling pathway, It plays a role in hematopoiesis maintenance, immune cell development, maturation, and functional competency acquisition. NKAP has been found to act as an oncogene in many tumors, but it has not been reported in PAAD.The purpose of this study was to investigate the effect of NKAP on the growth and metastasis of pancreatic adenocarcinoma(PAAD). In this study, western blot and qRT-PCR showed that highly expressed NKAP was found in PAAD cell lines, and small interfering RNA (siRNA) was employed to reduce the expression of NKAP in PAAD cell lines. The results of CCK-8, clony formation, Transwell and flow cytometry showed that knockdown of NKAP significantly inhibited biological function of PAAD cells, and increased cell apoptosis. Study also observed that knockdown of NKAP inhibited the expression levels of apoptosis proteins and cyclin in PAAD cells. In addition, mTOR's degree of phosphorylation and the expression of its downstream target p70S6K can both be activated by NKAP. This effect was also confirmed in salvage experiments performed with Rapamycin(RaPa), an inhibitor of mTOR. At the end of the experiment, It was investigated how NKAP affected the drug sensitivity of gemcitabine used to treat PAAD. The results showed that knocking down NKAP could increase the drug sensitivity of gemcitabine. NKAP as an oncogene regulates the development of PAAD cells. The research found that the mTOR signaling pathway is engaged in the oncogenic role of NKAP in PAAD for the first time.

Molecular profile of metastasis, cell plasticity and EMT in pancreatic cancer: a pre-clinical connection to aggressiveness and drug resistance.

The metastasis is a multistep process in which a small proportion of cancer cells are detached from the colony to enter into blood cells for obtaining a new place for metastasis and proliferation. The metastasis and cell plasticity are considered major causes of cancer-related deaths since they improve the malignancy of cancer cells and provide poor prognosis for patients. Furthermore, enhancement in the aggressiveness of cancer cells has been related to the development of drug resistance. Metastasis of pancreatic cancer (PC) cells has been considered one of the major causes of death in patients and their undesirable prognosis. PC is among the most malignant tumors of the gastrointestinal tract and in addition to lifestyle, smoking, and other factors, genomic changes play a key role in its progression. The stimulation of EMT in PC cells occurs as a result of changes in molecular interaction, and in addition to increasing metastasis, EMT participates in the development of chemoresistance. The epithelial, mesenchymal, and acinar cell plasticity can occur and determines the progression of PC. The major molecular pathways including STAT3, PTEN, PI3K/Akt, and Wnt participate in regulating the metastasis of PC cells. The communication in tumor microenvironment can provide by exosomes in determining PC metastasis. The components of tumor microenvironment including macrophages, neutrophils, and cancer-associated fibroblasts can modulate PC progression and the response of cancer cells to chemotherapy.

High-throughput functional screen identifies YWHAZ as a key regulator of pancreatic cancer metastasis

Pancreatic cancer is a leading cause of cancer death due to its early metastasis and limited response to the current therapies. Metastasis is a complicated multistep process, which is determined by complex genetic alterations. Despite the identification of many metastasis-related genes, distinguishing the drivers from numerous passengers and establishing the causality in cancer pathophysiology remains challenging. Here, we established a high-throughput and piggyBac transposon-based genetic screening platform, which enables either reduced or increased expression of chromosomal genes near the incorporation site of the gene search vector cassette that contains a doxycycline-regulated promoter. Using this strategy, we identified YWHAZ as a key regulator of pancreatic cancer metastasis. We demonstrated that functional activation of Ywhaz by the gene search vector led to enhanced metastatic capability in mouse pancreatic cancer cells. The metastasis-promoting role of YWHAZ was further validated in human pancreatic cancer cells. Overexpression of YWHAZ resulted in more aggressive metastatic phenotypes in vitro and a shorter survival rate in vivo by modulating epithelial-to-mesenchymal transition. Hence, our study established a high-throughput screening method to investigate the functional relevance of novel genes and validated YWHAZ as a key regulator of pancreatic cancer metastasis.

Retracted] P21 activated kinase2 promotes pancreatic cancer growth and metastasis.

[This retracts the article DOI: 10.3892/ol.2019.10040.].

NSUN2 stimulates tumor progression via enhancing TIAM2 mRNA stability in pancreatic cancer

NSUN2 is a nuclear RNA methyltransferase which catalyzes 5-methylcytosine (m5C), a posttranscriptional RNA modification. Aberrant m5C modification has been implicated in the development of multiple malignancies. However, its function in pancreatic cancer (PC) needs to be elucidated. Herein, we determined that NSUN2 was overexpressed in PC tissues and related to aggressive clinical features. Silence of NSUN2 by lentivirus weakened the capability of proliferation, migration and invasion of PC cells in vitro and inhibited the growth and metastasis of xenograft tumors in vivo. Contrarily, overexpression of NSUN2 stimulated PC growth and metastasis. Mechanistically, m5C-sequencing (m5C-seq) and RNA-sequencing (RNA-seq) were carried out to identify downstream targets of NSUN2 and results showed that loss of NSUN2 led to decreased m5C modification level concomitant with reduced TIAM2 mRNA expression. Further validation experiments proved that NSUN2 silence accelerated the decay of TIAM2 mRNA in a YBX1-dependent manner. Additionally, NSUN2 exerted its oncogenic function partially through enhancing TIAM2 transcription. More importantly, disruption of the NSUN2/TIAM2 axis repressed the malignant phenotype of PC cells through blocking epithelial-mesenchymal transition (EMT). Collectively, our study highlighted the critical function of NSUN2 in PC and provided novel mechanistic insights into NSUN2/TIAM2 axis as promising therapeutic targets against PC.

DUSP2 recruits CSNK2A1 to suppress AKT1-mediated apoptosis resistance under hypoxic microenvironment in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by hypoxic tumor microenvironment (TME), which aids tumor progression, drug resistance, and immune evasion. Dual-specificity phosphatase 2 (DUSP2), a member of the mitogen-activated protein kinase phosphatase family, regulates pancreatic cancer metastasis. However, its role in the hypoxic TME in PDAC remains unknown. We explored the role of DUSP2 by simulating the hypoxic TME. DUSP2 significantly promoted apoptosis in PDAC both in vitro and in vivo, mainly through AKT1 rather than ERK1/2. Mechanistically, DUSP2 competed with AKT1 to bind to casein kinase 2 alpha 1 (CSNK2A1) and inhibited the phosphorylation of AKT1, which plays a crucial role in apoptosis resistance. Interestingly, aberrant activation of AKT1 resulted in an increase in the ubiquitin E3 ligase tripartite motif-containing 21 (TRIM21), which binds to and mediates the ubiquitination-dependent proteasomal degradation of DUSP2. Overall, we identified CSNK2A1 as a novel binding partner of DUSP2 that promotes PDAC apoptosis through CSN2KA1/AKT1 in an ERK1/2-independent manner. Activation of AKT1 also mediated proteasomal degradation of DUSP2 via the AKT1/TRIM21 positive feedback loop. We propose increasing the level of DUSP2 as a potential therapeutic strategy for PDAC.

Epigenetic reprogramming-induced guanidinoacetic acid synthesis promotes pancreatic cancer metastasis and transcription-activating histone modifications

BackgroundPancreatic ductal adenocarcinoma (PDAC) tends to undergo distant metastasis, especially liver metastasis, leading to a poor prognosis. Metabolic remodelling and epigenetic reprogramming are two important hallmarks of malignant tumours and participate in regulating PDAC tumorigenesis and metastasis. However, the interaction between these two processes during PDAC metastasis has not been fully elucidated.MethodsWe performed metabolomics analysis to identify the critical metabolites associated with PDAC liver metastasis and focused on guanidinoacetic acid (GAA). Intracellular GAA content was significantly increased in liver metastatic PDAC cells compared to primary cancer cells in mouse xenograft tumour models. The effects of GAA supplementation and glycine amidinotransferase (GATM) knockdown on PDAC metastasis were assessed by analysing cell migration, filopodia formation, epithelial-mesenchymal transition (EMT), and in vivo metastasis in different cell and animal models. Next, ChIP‒qPCR, 3C‒qPCR, and CRISPRi/dCas9-KRAB experiments were used to validate the “epigenome-metabolome" mechanism. Finally, the results of in vitro approaches, including RNA-seq, CUT&RUN, RT‒qPCR, and western blot analyses, as well as luciferase reporter gene assay and transwell assay, revealed the GAA-c-Myc-HMGA axis and transcription-activating histone modifications reprogramming.ResultsA high level of intracellular GAA was associated with PDAC liver metastasis. GAA could promote the migration, EMT, and liver metastasis of pancreatic cancer cells in vitro and in vivo. Next, we explored the role of GATM-mediated de novo GAA synthesis in pancreatic cancer metastasis. High expression of GATM was positively correlated with advanced N stage in PDAC. Knockdown of GATM significantly reduced the intracellular level of GAA, suppressed EMT, and inhibited PDAC liver metastasis, and these effects were attenuated by GAA supplementation. Mechanistically, we identified the active enhancers looped to the Gatm gene locus that promoted GATM expression and PDAC liver metastasis. Furthermore, we found that GAA promoted cell migration and EMT by regulating c-Myc-mediated high mobility group AT-hook protein expression. Moreover, GAA increased the H3K4me3 modification level by upregulating histone methyltransferases, which induced the transcription of metastasis-related genes, including Myc.ConclusionsThese findings revealed the critical role of the epigenome-metabolome interaction in regulating PDAC liver metastasis and suggested potential therapeutic strategies targeting GAA metabolism and epigenetic regulatory mechanisms.