Secretory Trefoil Factor 1 (TFF1) promotes gemcitabine resistance through chemokine receptor CXCR4 in Pancreatic Ductal Adenocarcinoma.

Gemcitabine is the first-line treatment option for patients with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, the frequent adoption of resistance to gemcitabine by cancer cells poses a significant challenge in treating this aggressive disease. In this study, we focused on analyzing the role of trefoil factor 1 (TFF1) in gemcitabine resistance in PDAC. Analysis of PDAC TCGA and cell line datasets indicated an enrichment of TFF1 in the gemcitabine-resistant classical subtype and suggested an inverse correlation between TFF1 expression and sensitivity to gemcitabine treatment. The genetic ablation of TFF1 in PDAC cells enhanced their sensitivity to gemcitabine treatment in both in vitro and in vivo tumor xenografts. The biochemical studies revealed that TFF1 contributes to gemcitabine resistance through enhanced stemness, increasing migration ability of cancer cells, and induction of anti-apoptotic genes. We further pursued studies to predict possible receptors exerting TFF1-mediated gemcitabine resistance. Protein-protein docking investigations with BioLuminate software revealed that TFF1 binds to the chemokine receptor CXCR4, which was supported by real-time binding analysis of TFF1 and CXCR4 using SPR studies. The exogenous addition of TFF1 increased the proliferation and migration of PDAC cells through the pAkt/pERK axis, which was abrogated by treatment with a CXCR4-specific antagonist AMD3100. Overall, the present study demonstrates the contribution of the TFF1-CXCR4 axis in imparting gemcitabine resistance properties to PDAC cells.

Shah A ，Jahan R ，Kisling SG ，Atri P ，Natarajan G ，Nallasamy P ，Cox JL ，Macha MA ，Sheikh IA ，Ponnusamy MP ，Kumar S ，Batra SK ... -  《-》

G3BP2 promotes tumor progression and gemcitabine resistance in PDAC via regulating PDIA3-DKC1-hENT in a stress granules-dependent manner.

Pancreatic ductal adenocarcinoma (PDAC) is distinguished by its aggressive malignancy, limited treatment avenues and a tendency towards chemotherapy resistance, underscoring the critical need for advanced research to uncover new therapeutic approaches. Stress granules (SGs) that is implicated in cellular self-protection mechanism, along with its associated family molecules have shown pro-cancer effects and are closely related to tumor chemotherapy resistance. In this study we investigated the relationship between Ras GTPase-activating protein-binding proteins 2 (G3BP2), a core component of SGs, and the malignancy of PDAC as well as its resistance to the chemotherapy drug gemcitabine. Analyzing TCGA dataset revealed that the expression of G3BP1 and G3BP2 was significantly upregulated in PDAC compared with adjacent normal pancreatic tissues, and the high expression of G3BP2 rather than G3BP1 was significantly associated with poorer overall survival (OS) in PDAC patients. We demonstrated that knockdown of G3BP2 inhibited the proliferation and invasion of PANC-1 and CFPAC-1 cells in vitro and in vivo. By analyzing the differentially expressed genes in G3BP2 knockdown and overexpressed PANC-1 cells, we identified DKC1 that was associated with RNA stability and regulation as the target of G3BP2. We demonstrated that G3BP2 bound to PDIA3 mRNA and recruited them into SGs, increasing the stability of PDIA3 mRNA and attenuating its translation efficiency, thereby promoting DKC1 expression. Furthermore, DKC1 could bind to hENT mRNA and inhibited its expression, which enhanced gemcitabine resistance of PDAC. Therefore, we propose a novel mechanism wherein G3BP2 facilitates PDAC's resistance to chemotherapy by modulating PDIA3-DKC1-hENT in a SGs-dependent way, suggesting G3BP2 SGs a protentional therapeutic target for the treatment in PDAC.

Xing FL ，Li BR ，Fang YJ ，Liang C ，Liu J ，Wang W ，Xu J ，Yu XJ ，Qin Y ，Zhang B ... -  《-》

FOXM1-Driven CKS1B Upregulation Promotes Pancreatic Cancer Progression and Therapeutic Resistance.

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal malignancy with limited treatment options. Investigating novel therapeutic targets and understanding mechanisms of chemoresistance are crucial for improving patient outcomes. This study investigated the role of CKS1B in PDAC carcinogenesis, stemness and chemoresistance, and explores the underlying mechanisms driving its upregulation. The findings may provide novel therapeutic insights and potential strategies for the treatment of PDAC. Methods: CKS1B expression was analyzed in PDAC tissues and cell lines, its impact on cell proliferation, migration, apoptosis, stemness and chemosensitivity were evaluated by using in vitro and in vivo models, and its underlying mechanistic connection to transcription factor FOXM1 was explored by using molecular biology methods. Results: CKS1B was significantly upregulated in PDAC tissues and correlated with poor patient survival. CKS1B promoted PDAC cell proliferation, migration, and inhibited apoptosis. Expression of CKS1B enhanced the stemness properties of pancreatic cancer. CKS1B knockdown sensitized PDAC cells to the treatment of gemcitabine and oxaliplatin. Mechanistically, CKS1B is transcriptionally regulated by FOXM1, establishing a novel FOXM1-CKS1B signaling axis that regulates carcinogenesis, proliferation, migration, stemness, apoptosis, and drug resistance in PDAC. Conclusions: Our findings strongly suggest that CKS1B plays a critical role in PDAC progression, stemness and chemoresistance. Targeting the FOXM1-CKS1B axis represents a promising therapeutic strategy for PDAC patients.

Zhang L ，Wei F ，Sun Q ，Huang X ，Zou Q ，Jiang M ，Su Y ，Li S ，Li X ，Xie K ，He J ... -  《International Journal of Biological Sciences》

In vitro and in silico study of the synergistic anticancer effect of alpinumisoflavone with gemcitabine on pancreatic ductal adenocarcinoma through suppression of ribonucleotide reductase subunit-M1.

A highly aggressive neoplastic disease, pancreatic ductal adenocarcinoma (PDAC) is documented as the third chief cause of cancer-associated mortality in both sexes combined in the United States. For decades, gemcitabine-based chemotherapy has been embraced as a cornerstone drug for the treatment of PDAC. However, there have been several unsolved problems, including cytotoxicity, and chemoresistance. Gemcitabine efficacy was attributed to the attenuation of ribonucleotide reductase subunit-M1 (RRM1). Overexpression of RRM1 in PDAC is highly correlated with gemcitabine resistance and reduced gemcitabine sensitivity, resulting in a poor survival rate even after gemcitabine treatment. Moreover, the status of TP53, a tumor suppressor gene, assumes a decisive role in the response of PDAC to gemcitabine. Therefore, targeting RRM1 and P53 might be a therapeutic strategy for strengthening gemcitabine efficacy and cytotoxicity against PDAC. Alpinumisoflavone (AIF) is a prenylated isoflavone originated in Cudrania tricuspidate with versatile bioactive properties, including anticancer activity. However, there was no report whether AIF can exert anticancer effect and exhibit synergistic effect with gemcitabine against PDAC. Therefore, the anticancer properties of AIF were assessed with PANC-1 and MIA PaCa-2. In addition, synergism between AIF and gemcitabine were analyzed. Moreover, the contribution of P53 and RRM1 expression to gemcitabine resistance was assessed by comparing their protein levels in PDAC cells and normal pancreatic cells. The interactions of AIF with RRM1 protein were confirmed by molecular docking and dynamics simulation. Therefore, AIF enhances gemcitabine efficacy against PDAC through the regulation of P53 and RRM1.

Lee W ，Song G ，Bae H 《-》

Epigenetic Activation of the CMTM6-IGF2BP1-EP300 Positive Feedback Loop Drives Gemcitabine Resistance in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with a dismal prognosis. Gemcitabine-based chemotherapy has emerged as a first-line treatment for PDAC. However, the development of gemcitabine resistance often results in therapeutic failure. In order to uncover the underlying mechanisms of gemcitabine resistance, gemcitabine-resistant PDAC cell lines and patient-derived xenograft (PDX) models are established and subjected to RNA sequencing. It is found that CMTM6 is closely related to gemcitabine resistance in PDAC. Multi-omics analysis revealed that EP300-mediated H3K27ac modification is involved in the transcriptional activation of CMTM6, which maintains IGF2BP1 expression by preventing its ubiquitination. The m6A reader IGF2BP1 stabilizes the EP300 and MYC mRNAs by recognizing m6A modifications, forming a positive feedback loop that enhances tumor stemness and ultimately contributes to PDAC resistance. The combined application of the EP300 inhibitor inobrodib and gemcitabine exerts a synergistic effect on PDAC. Overall, these findings reveal that the EP300-CMTM6-IGF2BP1 positive feedback loop facilitates gemcitabine resistance via epigenetic reprogramming and the combined use of inobrodib and gemcitabine represents a promising strategy for overcoming chemoresistance in PDAC, warranting further investigation in clinical trials.

Zhu YQ ，Huang Y ，Shi YH ，Huang CS ，Zhao GY ，Liu ZD ，Ma MJ ，Ye JY ，Xu X ，Liu Q ，Huang XT ，Wang JQ ，Xu QC ，Yin XY ... -  《Advanced Science》