Pancreatic Adenocarcinoma Up-regulated Factor Research Articles

Pancreatic Adenocarcinoma Up-Regulated Factor (PAUF) Transforms Human Monocytes into Alternative M2 Macrophages with Immunosuppressive Action.

Tumor-associated macrophages (TAMs) in the tumor microenvironment (TME) promote immune evasion, cancer cell proliferation, and metastasis. Ongoing research is focused on finding ways to prevent tumor growth by inhibiting TAM polarization, which has shown a correlation with unfavorable prognosis in clinical studies. Pancreatic adenocarcinoma up-regulated factor (PAUF) is a protein secreted from pancreatic cancer (PC) and acts as a TME modulator that affects the TME by acting on not only cancer cells but also stromal cells and immune cells. Tumor cells can evade the immune system by PAUF binding to Toll-like receptor (TLR) in monocytes, as this research shows. In this study, the examination centered around the recruitment of human monocytes by PAUF and the subsequent differentiation into macrophages. In an in vitro chemotaxis assay, PAUF induced chemotactic migration of TLR2-mediated monocytes. In addition, PAUF induced differentiation of monocytes into M2 macrophages, which was verified based on expressing surface markers and cytokines and morphological analysis. The inhibition of T cell proliferation and function was observed in differentiated M2 macrophages. To conclude, these findings indicate that PAUF functions as a promoter of cancer progression by regulating the recruitment and differentiation of macrophages within TMEs, ultimately causing immunosuppression.

TGF-β-Induced PAUF Plays a Pivotal Role in the Migration and Invasion of Human Pancreatic Ductal Adenocarcinoma Cell Line Panc-1.

Pancreatic adenocarcinoma upregulated factor (PAUF) was initially identified as a secreted protein that is substantially expressed in pancreatic ductal adenocarcinoma (PDAC). PAUF also affects invasiveness, motility, and the proliferation of cells in several types of cancer. Recently, PAUF was reported to play a pivotal role in the TLR4-mediated migration and invasion of PDAC cells. However, the mechanism inducing PAUF expression and its functional role in TGF-β-stimulated PDAC cells have not yet been studied. Thus, we first assessed whether TGF-β regulates PAUF expression in several PDAC cell lines and found a significant increase in PAUF expression in Smad signaling-positive Panc-1 cells treated with TGF-β. We also found that the PAUF promoter region contains a Smad-binding element. TGF-β-treated Panc-1 cells showed an increase in PAUF promoter activity, but this effect was not observed in TGF-β-stimulated Smad4-null BxPC-3 cells. Restoring Smad4 expression increased the PAUF promoter activity and expression in Smad4-overexpressing BxPC-3 cells treated with TGF-β. We further found that PAUF aggravated the TGF-β-induced epithelial-mesenchymal transition (EMT) in Panc-1 and BxPC-3 cells via the activation of MEK-ERK signaling. These results indicate that TGF-β/Smad signaling-mediated upregulation of PAUF plays a crucial role in EMT progression by activating the TGF-β-mediated MEK-ERK signaling pathway.

PBP1510, a novel monoclonal antibody targeting pancreatic adenocarcinoma upregulated factor (PAUF): Phase 1/2a monotherapy and combination with gemcitabine in patients with advanced/metastatic pancreatic cancer.

e16296 Background: PAUF, a protein overexpressed in pancreatic cancer but not in non-cancerous tissues, plays a key role in cancer progression and metastasis. PBP1510 is a novel first-in-class humanized IgG1 monoclonal antibody that binds to and neutralizes PAUF with high specificity and affinity. PAUF-I (NCT05141149) is a first-in-human, multicenter, open-label study in patients with advanced/metastatic pancreatic cancer. Early Phase 1 results are presented here. Methods: Key eligibility criteria for Phase 1 include: locally advanced/metastatic pancreatic cancer; at least 1 previous line of chemotherapy; ECOG 0-1; and measurable disease by RECIST v1.1. A 3+3 dose escalation design is planned for 5 dose levels of intravenous PBP1510 (doses of 1, 3, 6, 10, and 15 mg/kg), either alone (monotherapy cohorts) or in combination with gemcitabine at a dose of 1000 mg/m2 (combination cohorts), in 28-day cycles. Tumor assessments are performed every 8 weeks from the first dose of PBP1510. Dose is escalated following a safety review committee meeting, if all patients in a cohort complete the dose-limiting toxicity (DLT) observation period (28 days from first dose) without any DLTs. Primary endpoints are safety parameters including treatment emergent adverse events (TEAEs) and laboratory findings. Results: As of January 2024, 6 patients (4 males, 2 females), aged 54-71 years, were enrolled. All patients had stage IV ductal adenocarcinoma and had received at least 2 prior lines of chemotherapy. Five patients received 2 cycles of PBP1510 each at 1 mg/kg or 3 mg/kg based on their cohort. One patient received 1 cycle of PBP1510 at 3 mg/kg. Seventeen TEAEs were assessed to be related to study treatment. The most frequently reported treatment-related TEAE was asthenia (n = 7). Most treatment-related TEAEs were NCI-CTCAE Grade 1 in severity (n = 14). Five serious TEAEs not related to study treatment were reported in 2 patients. There was 1 death reported due to disease progression. No patient discontinued treatment due to TEAEs. No clinically significant abnormalities in ECG, LVEF, and clinical laboratory assessments were reported during the DLT observation period. All patients in the first 2 monotherapy cohorts completed the DLT observation period without any DLTs. Conclusions: PBP1510 was well tolerated by all patients at 1 mg/kg or 3 mg/kg in the first 2 monotherapy cohorts. The next monotherapy (PBP1510, 6 mg/kg) and combination (PBP1510, 1 mg/kg; gemcitabine 1000 mg/m2) cohorts are open for recruitment. Clinical trial information: NCT05141149 .

Abstract CT083: A first-in-human phase 1/2a study of a novel anti-PAUF monoclonal antibody PBP1510 in patients with advanced/metastatic pancreatic cancer

Abstract Background Pancreatic Adenocarcinoma Up-regulated Factor (PAUF) is a protein overexpressed in pancreatic cancer but not in non-cancerous tissues and plays an important role in carcinogenesis and metastasis. PBP1510 is a first-in-class, anti-PAUF humanized immunoglobulin G1 monoclonal antibody developed for treatment of pancreatic cancer. PBP1510 demonstrated promising pancreatic cancer growth inhibition efficacies in in vivo patient-derived xenograft studies and is being evaluated in humans for the first time in the ongoing PAUF-I study. Methods PAUF-I (NCT05141149) is an open-label, multi-center, Phase 1/2a study in advanced/metastatic pancreatic cancer patients. Eligible patients must have a tumor that has progressed on standard chemotherapy, with at least 1 measurable lesion per RECIST v1.1 criteria, an ECOG performance status score of 0 or 1, a life expectancy of ≥ 3 months, and adequate baseline organ function to enroll. PBP1510 is administered as a 90-minute intravenous infusion in 28-day cycles and tumor assessments are performed every 8 weeks from the first dose. Phase 1 uses a 3 + 3 dose-escalation design to assess the safety, tolerability, pharmacokinetics (PK), and immunogenicity of ascending doses of PBP1510 as a single agent or in combination with gemcitabine (Table 1). The observation period for dose-limiting toxicities (DLT) is 28 days. ORR and pre- and post-treatment PAUF levels in tumor tissue will be explored in the analyses. A recommended phase 2 dose (RP2D) will be selected based on PK, safety, and efficacy data from Phase 1. Phase 2a is the dose expansion phase which aims to evaluate the safety, tolerability, PK, immunogenicity, and efficacy of PBP1510 administered at RP2D in combination with gemcitabine. As of January 2024, 6 patients have been enrolled. The 1M cohort (1 mg/kg) was completed without any report of DLT. Dose escalation is in progress and DLT evaluation is ongoing for the 2nd and 3rd patients in the 2M cohort. TABLE 1: NAND Dose escalation and cohorts (Phase 1) Monotherapy Combination Cohort PBP1510 Dose (mg/kg) Gemcitabine Dose (mg/m2) Cohort PBP1510 Dose (mg/kg) Gemcitabine Dose (mg/m2) 1M 1 - 1C 1 1000 2M 3 - 2C 3 1000 3M 6 - 3C 6 1000 4M 10 - 4C 10 1000 5M 15 - 5C 15 1000 Citation Format: Jaime Feliu Batlle, Daniel A. King, Jamie Kim, Sumita Pradhan, Yun-Yong Park, Kedar Diwakar Mandakhalikar, Wei Qi Loh. A first-in-human phase 1/2a study of a novel anti-PAUF monoclonal antibody PBP1510 in patients with advanced/metastatic pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT083.

Abstract 3611: PAUF induces migration of human pancreatic cancer cells exclusively via the TLR4/MyD88/NF-κB signaling pathway

Abstract Background: Pancreatic adenocarcinoma up-regulated factor (PAUF) is a cancer-secreted protein which is overexpressed on pancreatic cancer (PC) cells and promotes tumor growth in an autocrine way. However, the receptor of PAUF on PC cells has yet to be identified. Meanwhile, it is known that PAUF, as a tumor microenvironment (TME) modulator, plays a role in immune evasion and suppression through toll-like receptors notably TLR4 which are mainly expressed on immune cells. Previous studies show that TLR4 is also highly expressed in PC tumor tissues, compared to normal tissues, and activation of TLR4 signaling pathway induces the migration and invasion of PC cells. Objective: This study aimed to investigate if TLR4 expressed on cancer cells can act as a receptor for PAUF to mediate its tumor promoting effects. Methods and Results: We tested the TLR4 expression in six PC cell lines and one normal pancreatic cell line. And confirmed that TLR4 is expressed in all PC cell lines at variable levels, but not in the normal pancreatic cell line.Next, we found that a chemical TLR4-specific inhibitor TAK-242 significantly reduced the migration of PC cells with high TLR4 expression (BxPC-3), but it did not impact the migration of PC cells with low TLR4 expression (Panc-1). This experiment suggests that some endogenous ligands of TLR4 may have mediated PC cell migration.Using TLR4 overexpressed and knockout PC cell lines, we showed that treatment with recombinant PAUF increased the migration and invasion of TLR4 overexpressed PC cells, but not in the TLR4 knockout cells. Likewise, treatment of anti-PAUF antibody reduced the migration and invasion of TLR4 overexpressed PC cells, but not in the TLR4 knockout cells. These results shows that PAUF’s migration and invasion promoting effects of PC cells is TLR4 dependent.To further understand the molecular mechanism of PAUF-induced metastasis (migration/invasion)-promoting effects via TLR4, we conducted a series of in vitro studies including immunoprecipitation (IP), western blot analysis, flow cytometry, and luciferase reporter assay. We demonstrated that PAUF activates TLR4/MyD88 signaling pathway, but not TLR4/TRIF pathway. Conclusions: In conclusion, for the first time this study demonstrates that TLR4 expressed on PC cell surfaces functions as a receptor of PAUF to mediate its metastasis-promoting effects, which are exclusively through the MyD88/NF-κB signaling pathway. This study also suggests TLR4 as a potential biomarker for identification of optimal patients, and a new therapeutic target to treat PC. Anti-PAUF antibody used in this study is currently evaluated by clinical trials in France, Spain, and US FDA. Citation Format: Fen Jiang, So Eun Youn, Da Eun Hong, Tae Heung Kang, Hye Yun Won, Yun Yong Park, Sang Seok Koh. PAUF induces migration of human pancreatic cancer cells exclusively via the TLR4/MyD88/NF-κB signaling pathway. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3611.

First-in-class monoclonal antibody (mAb) PBP1510 targeting pancreatic adenocarcinoma upregulated factor (PAUF) for pancreatic cancer (PC) treatment: Preclinical perspectives.

e16274 Background: PAUF has been shown to induce PC cell proliferation, angiogenesis and evasion of immune surveillance, thereby promoting tumour progression and metastasis. PBP1510, a novel humanized IgG1 mAb developed by Prestige Biopharma Limited, Singapore, binds to and neutralizes PAUF with high specificity and affinity. With no available targeted therapies against PAUF, the first in its class, PBP1510, has been granted Orphan Drug Designation by EMA, US FDA and Korea MFDS. Methods: To assess inhibition of migration and invasion of PC in vitro, PC cell lines (CFPAC-1 and BxPC-3) with high expression levels of PAUF, and primary PC cells extracted from patients were treated with PBP1510 or human IgG (negative control). Suitability of cynomolgus monkey as animal model for pharmacokinetic (PK) and toxicity studies was verified by comparing binding affinities of PBP1510 to human and monkey PAUF. PK characteristics and immunogenicity of PBP1510 (up to 20 mg/kg), were examined in single dose studies in 6 monkeys. A 4-week repeated dose toxicity study was also conducted in 32 monkeys with PBP1510 (up to 40 mg/kg). An in vitro tissue cross-reactivity study was also conducted in a full panel of normal human tissues, to assess potential toxicity in humans. Results: PBP1510 suppressed the proliferation of the PC cell lines compared to negative control. The migration and invasion of PBP1510 treated PC cell lines as well as the primary tumour cells from patients was significantly reduced compared to the respective control groups in vitro. Similarity in binding affinity of PBP1510 to human PAUF and monkey PAUF, and amino acid sequence homology between human and monkey PAUF, suggest that monkey is an appropriate animal species for toxicity and PK studies of PBP1510. In monkey studies, a dose-proportional increase in systemic exposure was observed at low and high doses. PBP1510 at doses up to 40 mg/kg was well tolerated by study animals and no notable local or systemic toxicity was observed. Low immunogenic profile of PBP1510 was indicated by an absence of anti-PBP1510 antibodies till up to 57 days (8 doses and 28-day recovery period). These data are used to simulate human PK profile and to derive the starting dose and maximum escalated dose for the upcoming Phase 1 clinical studies. Cross-reactivity results did not reveal non-specific binding of PBP1510 in the human tissues except in the cytoplasm of acinar and duct epithelium in the salivary gland which is not expected to be of major toxicologic significance. Conclusions: The efficacy and safety data presented here, along with the data from in vivo mouse studies demonstrating superior anti-tumour activity of PBP1510 treatment, support further clinical development of PBP1510 as a novel anti-cancer agent to treat PAUF-positive PC. The pivotal step of advancing PBP1510 into initial human studies is now in progress.

PAUF as a Target for Treatment of High PAUF-Expressing Ovarian Cancer.

Pancreatic adenocarcinoma up-regulated factor (PAUF) plays an important role in tumor growth, metastasis, and immune evasion in the pancreatic tumor microenvironment, and recent studies suggest an association between PAUF expression and poor prognosis in ovarian cancer patients. The current study aimed 1) to characterize the potential tumor-promoting role of PAUF in ovarian cancer, using in vitro and in vivo models, including a PAUF-knockout OVCAR-5 cell line, and 2) to explore the potential therapeutic effects of an anti-PAUF antibody for ovarian cancer. Recombinant PAUF significantly increased tumor metastatic capacity (migration, invasion, and adhesion) in all the ovarian cancer cell lines tested, except for the OVCAR-5 cell line which expresses PAUF at a much higher level than the other cells. PAUF-knockout in the OVCAR-5 cell line led to apparently delayed tumor growth in vitro and in vivo. Furthermore, the administration of an anti-PAUF antibody exhibited notable sensitizing and synchronizing effects on docetaxel in mice bearing the OVCAR-5 xenograft tumors. Taken together, this study shows that the expression level of PAUF is an independent factor determining malignant behaviors of ovarian cancer and, for the first time, it suggests that PAUF may be a promising therapeutic target for high PAUF-expressing ovarian cancer.

3P Targeting pancreatic adenocarcinoma upregulated factor (PAUF) to treat pancreatic cancer (PC): In vivo efficacy and safety of PBP1510, a first in class monoclonal antibody (mAb)

PAUF plays a key role in PC tumour progression and metastasis by inducing cancer cell proliferation, angiogenesis and evasion of immune surveillance. PBP1510 developed by Prestige Biopharma Limited, is a novel humanized IgG1 mAb that binds to and neutralizes PAUF with high specificity and affinity. There are no targeted therapies against PAUF, making PBP1510 the first in this class.

Knockdown of pancreatic adenocarcinoma upregulated factor (PAUF) suppresses proliferation, migration, invasion, and cancer stem cell properties in lung cancer cells


 
 
 
 Purpose: To investigate the role of pancreatic adenocarcinoma up-regulated factor (PAUF) in lung cancer.
 Method: Proliferation of lung cancer cell lines (A549 and H1299) was determined using MTS and Edu staining assays. Wound healing and transwell assays were performed to evaluate cell migration and invasion abilities. Lung cancer stem cell (CSC) marker expressions, including CD133, CD44, ALDH1, SOX2, and Oct4, were determined by western blot assay.
 Results: Knockdown of PAUF significantly inhibited A459 and H1299 cell proliferation (p < 0.01). The wound healing and transwell assay results indicated that depletion of PAUF markedly suppressed H1299 and A549 cell migration and invasion, compared with the control cells (p < 0.01). Knockdown of PAUF reduced distinct CSC marker expression, suggesting inhibition of CSC phenotypes, and reduced phosphorylated focal adhesion kinase (FAK), phosphorylated Src, and phosphorylated extracellular signal-regulated kinase (ERK), but not total FAK, Src, and ERK. These results suggested that knockdown of PAUF deactivated the FAK/Src/ERK signal pathway.
 Conclusion: Knockdown of PAUF inhibits lung cancer cell proliferation, migration, invasion, and CSC properties via deactivation of FAK/Src/ERK signal pathway. These results may provide a novel strategy for the development of lung cancer therapeutics.
 
 
 

Pancreatic cancer induces muscle wasting by promoting the release of pancreatic adenocarcinoma upregulated factor

Cancer cachexia is a highly debilitating condition characterized by weight loss and muscle wasting that contributes significantly to the morbidity and mortality of pancreatic cancer. The factors that induce cachexia in pancreatic cancer are largely unknown. We previously showed that pancreatic adenocarcinoma upregulated factor (PAUF) secreted by pancreatic cancer cells is responsible for tumor growth and metastasis. Here, we analyzed the relation between pancreatic cancer-derived PAUF and cancer cachexia in mice and its clinical significance. Body weight loss and muscle weight loss were significantly higher in mice with Panc-1/PAUF tumors than in those with Panc-1/Mock tumors. Direct administration of rPAUF to muscle recapitulated tumor-induced atrophy, and a PAUF-neutralizing antibody abrogated tumor-induced muscle wasting in Panc-1/PAUF tumor-bearing mice. C2C12 myotubes treated with rPAUF exhibited rapid inactivation of Akt-Foxo3a signaling, resulting in Atrogin1/MAFbx upregulation, myosin heavy chain loss, and muscle atrophy. The neutrophil-to-lymphocyte ratio and body weight loss were significantly higher in pancreatic cancer patients with high PAUF expression than in those with low PAUF expression. Analysis of different pancreatic cancer datasets showed that PAUF expression was significantly higher in the pancreatic cancer group than in the nontumor group. Analysis of The Cancer Genome Atlas data found associations between high PAUF expression or a high DNA copy number and poor overall survival. Our data identified tumor-secreted circulating PAUF as a key factor of cachexia, causing muscle wasting in mice. Neutralizing PAUF may be a useful therapeutic strategy for the treatment of pancreatic cancer-induced cachexia.

PAUF/ZG16B promotes colorectal cancer progression through alterations of the mitotic functions and the Wnt/β-catenin pathway.

Pancreatic adenocarcinoma upregulated factor (PAUF), also known as ZG16B, was previously found in the secretome of metastatic colorectal cancer cells. Here, we demonstrated the presence of PAUF at the intracellular level and its multiple effects on cancer progression. An initial decline of PAUF expression was observed at early stages of colorectal cancer followed by an increase at the metastatic site. PAUF was located at different cellular compartments: membrane-associated vesicles, endosomes, microtubule-associated vesicles, cell growth cones and the cell nucleus. PAUF loss in two colorectal cancer cell lines caused severe alterations in the cell phenotype and cell cycle, including tetraploidy, extensive genomic alterations, micronuclei and increased apoptosis. An exhaustive analysis of the PAUF interactome using different proteomic approaches revealed the presence of multiple components of the cell cycle, mitotic checkpoint, Wnt pathway and intracellular transport. Among the interacting proteins we found ZW10, a moonlighting protein with a dual function in membrane trafficking and mitosis. In addition, PAUF silencing was associated to APC loss and increased β-catenin nuclear expression. Altogether, our results suggest that PAUF depletion increases aneuploidy, promotes apoptosis and activates the Wnt/β-catenin pathway in colorectal cancer cells facilitating cancer progression. In summary, PAUF behaves as a multifunctional protein, with different roles in cancer progression according to the extra- or intracellular expression, suggesting a therapeutic value for colorectal cancer.

Elevated expression of pancreatic adenocarcinoma upregulated factor (PAUF) is associated with poor prognosis and chemoresistance in epithelial ovarian cancer

Pancreatic adenocarcinoma upregulated factor (PAUF) is a ligand of toll-like receptors (TLRs) and has been reported to be involved in pancreatic tumor development. However, the significance of PAUF expression in epithelial ovarian cancer remains unclear. We aimed to investigate the possible clinical significance of PAUF in epithelial ovarian cancer. We examined the link between PAUF and TLR4 in ovarian cancer cell lines. Recombinant PAUF induced cell activation and proliferation in ovarian cancer cell lines, whereas PAUF knockdown inhibited these properties. Subsequently, we assessed PAUF and TLR4 expression by immunohistochemistry on tissue microarray of 408 ovarian samples ranging from normal to metastatic. PAUF expression positively correlated with TLR4 expression. Overexpression of PAUF was associated with high-grade tumor (p = 0.014) and chemoresistant tumor (p = 0.017). Similarly, high expression of TLR4 correlated with advanced tumor stage (p = 0.002) and chemoresistant tumor (p = 0.001). Multivariate analysis indicated that PAUFhigh, TLR4high, and PAUFhigh/TLR4high expression are independent prognostic factor for progression-free survival, while TLR4high and PAUFhigh/TLR4high expression were independent prognostic factors for overall survival. Our results suggest that PAUF has a role in ovarian cancer progression and is a potential prognostic marker and novel chemotherapeutic target for ovarian cancer.

DCPP1 is the mouse ortholog of human PAUF that possesses functional analogy in pancreatic cancer

Pancreatic adenocarcinoma upregulated factor (PAUF) overexpressed in pancreatic ductal adenocarcinoma (PDAC) plays a major role in tumor progression and metastasis by autocrine and paracrine manners. However, underlying molecular mechanism of PAUF functioning in pancreatic cancer are not fully understood yet. The objective of this study was to evaluate the potential of demilune cell and parotid protein 1 (DCPP1) as a putative mouse ortholog of human PAUF by sequence alignment and functional studies. Overexpression of mouse DCPP1 in Chinese hamster ovary (CHO) cells or pancreatic cancer cells increased cell proliferation, migration, invasion, and adhesion ability in vitro. Treatment of human pancreatic cancer cells with recombinant mouse DCPP1 elevated cell growth, motility, invasiveness, and adhesiveness. Mouse DCPP1 exerted its function on pancreatic cancer cells by activating intracellular signaling pathways involved in aggressive cancer phenotype of human pancreatic cancer cells. Moreover, subcutaneous injection of mice with DCPP1-overexpressing CHO cells increased tumor sizes. Taken together, we conclude that mouse DCPP1 is a multifunctional promoter of tumor growth through functional activation of pancreatic cancer cells, suggesting it to be an ortholog of human PAUF.

Suppression of pancreatic adenocarcinoma upregulated factor (PAUF) increases the sensitivity of pancreatic cancer to gemcitabine and 5FU, and inhibits the formation of pancreatic cancer stem like cells.

Pancreatic cancer stem cells (CSCs) play a crucial role in tumorigenesis and chemoresistance of pancreatic ductal adenocarcinoma. Pancreatic adenocarcinoma up-regulated factor (PAUF), a novel secretory protein, has been shown to contribute to cancer progression and metastasis. Because the clinical relationship between PAUF and pancreatic CSCs is largely unknown, we investigated the associations between the functional role of PAUF and pancreatic CSCs. Pancreatic cancer sphere cultured from the CFPAC-1 cells showed elevated expression of PAUF and pluripotent stemness genes (Oct4, Nanog, Stat3, and Sox2), and the mRNA of PAUF were increased in CD44+CD24+ESA+ pancreatic CSCs. PAUF knockdown (shPAUF) CFPAC-1 diminished the number of spheres and decreased stemness genes and CSC surface markers (CD133, c-MET and ALDH1). In addition, siPAUF CFPAC-1 decreased the mRNA expression of multidrug resistant protein 5 (MRP5) and ribonucleotide reductase M2 (RRM2) and were more vulnerable to gemcitabine and 5-FU than negative control (p<0.05). In conclusion, PAUF was increased in pancreatic CSCs and the suppression of PAUF enhances chemotherapeutic response to gemcitabine and 5FU by decreasing MRP5 and RRM2 in pancreatic cancer cells.

Silencing pancreatic adenocarcinoma up-regulated factor increases the sensitivity of pancreatic cancer cell line to gemcitabine

Objective To observe the influence on the sensitivity of pancreatic cancer cell line BxPC-3 to gemcitabine of silencing PAUF gene. Methods BxPC-3 cells, which overexpress PAUF, was stably transfected with PAUF-shCtrl and PAUF-shRNA to establish BxPC-3_shCtrl and BxPC-3_shPAUF cells as control and experiment group. Then the mRNA and protein expression level of PAUF in these two cell lines were detected by RT-PCR and western blot, respectively. The growth inhibition rates of these two cell lines treated with different concentrations of gemcitabine (0, 3.1, 6.25, 12.5, 25, 50, 100, 200 nmol/L) were detected by MTT. Apoptosis rates in the cells treated with different concentrations of gemcitabine (0, 75, 100 nmol/L) were then observed by flow cytometry. Results The relative PAUF mRNA expression level in BxPC-3_shCtrl and BxPC-3 cells were 1.00±0.06 and 0.83±0.07, which were significantly higher than that in BxPC-3_shPAUF cells (0.25±0.02; both P<0.05). The relative PAUF protein expression level in BxPC-3_shCtrl and BxPC-3 cells were 0.89±0.07 and 0.95±0.04, which were significantly higher than that in BxPC-3_shPAUF cells (0.31±0.03; both P<0.05). The IC50 value of gemcitabine to BxPC-3_shCtrl cell was (22.88±2.43) nmol/L, which was significantly higher than that of BxPC-3_shPAUF cells [(1.06±0.02) nmol/L; P<0.05]; apoptosis rate of BxPC-3_shPAUF cells treated by gemcitabine increased faster than that of BxPC-3_shCtrl cells. Conclusion PAUF silencing could greatly enhance the sensitivity of BxPC-3 cells to gemcitabine. Key words: Pancreatic cancer cell line; Pancreatic adenocarcinoma up-regulated factor; Gemcitabine; Drug sensitization

Pancreatic adenocarcinoma up-regulated factor has oncogenic functions in oral squamous cell carcinoma.

Pancreatic adenocarcinoma up-regulated factor (PAUF) is a novel secretory protein which promotes tumour progression, metastasis and poor prognosis in pancreatic, cervical and colorectal carcinoma. It is also associated with gemcitabine resistance in pancreatic cancer cells. However, the expression and function of PAUF in oral squamous cell carcinoma (OSCC) remain unknown. We performed an immunohistochemical analysis of PAUF in 222 clinicopathologically characterized cases of OSCC. We also investigated the growth, invasion, apoptosis induction and cisplatin resistance of OSCC cells under PAUF knockdown treatment. PAUF was localized in normal salivary glands. In OSCC, immunostaining for PAUF was found in 52 of 222 patients (23.4%), and correlated with nodal metastasis (P < 0.0001) and poor prognosis (P < 0.0001). Multivariate analysis using the Cox proportional hazards model identified that PAUF expression was an independent predictor of disease-free survival in OSCC (P < 0.0001). The down-regulation of PAUF in OSCC cells suppressed cell growth and invasion and induced apoptosis and cisplatin sensitivity. Our results suggest that PAUF has tumour-promoting functions in OSCC. It may thus be a useful diagnostic and therapeutic marker for OSCC.

Pancreatic adenocarcinoma up-regulated factor (PAUF) enhances the accumulation and functional activity of myeloid-derived suppressor cells (MDSCs) in pancreatic cancer.

Pancreatic cancer is characterized by an immunosuppressive tumor microenvironment (TME) with a profound immune infiltrate populated by a significant number of myeloid-derived suppressor cells (MDSCs). MDSCs have been increasingly recognized for their role in immune evasion and cancer progression as well as their potential as a target for immunotherapy. However, not much is known about the mechanisms regulating their behavior and function in the pancreatic TME. Here we report that pancreatic adenocarcinoma up-regulated factor (PAUF), a soluble protein involved in pancreatic tumorigenesis and metastasis, plays a role as an enhancer of tumor-infiltrating MDSC and its functional activity. We show that PAUF enhanced the accumulation of MDSCs in the spleen and tumor tissues of PAUF-overexpressing tumor cell-injected mice. In addition, PAUF was found to enhance the immunosuppressive function of MDSCs via the TLR4-mediated signaling pathway, which was demonstrated by PAUF-induced increased levels of arginase, nitric oxide (NO), and reactive oxygen species (ROS). The role of PAUF in modulating the functional properties of MDSCs was further demonstrated by the use of a PAUF-neutralizing antibody that caused a decreased number of tumor-infiltrating MDSCs and reduced MDSC immunosuppressive activity. The observations made in mice were confirmed in human pancreatic cancer patient-derived MDSCs, supporting the clinical relevance of our findings. Collectively, we conclude that the PAUF is a powerful and multifunctional promoter of tumor growth through increase and functional activation of MDSCs, suggesting therapeutic potential for targeting PAUF in pancreatic cancers.

Silencing pancreatic adenocarcinoma upregulated factor (PAUF) increases the sensitivity of pancreatic cancer cells to gemcitabine.

Pancreatic adenocarcinoma upregulated factor (PAUF) is a new oncogene that activates signaling pathways that play a critical role in resistance to gemcitabine. We thus speculated that PAUF also plays a role in resistance to gemcitabine of pancreatic cancer cells. We established BxPC-3 cell lines with stable PAUF knockdown (BxPC-3_shPAUF) and controls (BxPC-3_shCtrl) and evaluated sensitivity to gemcitabine in vitro by MTT and flow cytometry. We established a xenograft model of human pancreatic cancer to examine PAUF function in gemcitabine resistance in vivo. Gene chip microarrays were performed to identify differentially expressed genes in BxPC-3_shPAUF and BxPC-3_shCtrl cells. Silencing PAUF increased the sensitivity of BxPC-3 cells to gemcitabine in vitro and in vivo. PAUF-knockdown BxPC-3 cell lines treated with gemcitabine showed increased proliferation inhibition and apoptosis compared with controls. Gemcitabine exhibited a more pronounced effect on reduction of BxPC-3_shPAUF tumors than BxPC-3_shCtrl tumors. Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL) assays confirmed a significantly higher apoptotic rate of BXPC-3_shPAUF tumors compared with BXPC-3_shCtrl tumors. Gene array showed that PAUF function in gemcitabine sensitivity might involve MRP2, MRP3, MDR1, PIK3R1, and NFkB2 genes. PAUF could be considered as a key molecular target for sensitizing pancreatic cancer cells to gemcitabine.

CARTS biogenesis requires VAP-lipid transfer protein complexes functioning at the endoplasmic reticulum-Golgi interface.

Vesicle-associated membrane protein-associated protein (VAP) is an endoplasmic reticulum (ER)-resident integral membrane protein that controls a nonvesicular mode of ceramide and cholesterol transfer from the ER to the Golgi complex by interacting with ceramide transfer protein and oxysterol-binding protein (OSBP), respectively. We report that VAP and its interacting proteins are required for the processing and secretion of pancreatic adenocarcinoma up-regulated factor, whose transport from the trans-Golgi network (TGN) to the cell surface is mediated by transport carriers called "carriers of the trans-Golgi network to the cell surface" (CARTS). In VAP-depleted cells, diacylglycerol level at the TGN was decreased and CARTS formation was impaired. We found that VAP forms a complex with not only OSBP but also Sac1 phosphoinositide phosphatase at specialized ER subdomains that are closely apposed to the trans-Golgi/TGN, most likely reflecting membrane contact sites. Immobilization of ER-Golgi contacts dramatically reduced CARTS production, indicating that association-dissociation dynamics of the two membranes are important. On the basis of these findings, we propose that the ER-Golgi contacts play a pivotal role in lipid metabolism to control the biogenesis of transport carriers from the TGN.

Pancreatic adenocarcinoma upregulated factor serves as adjuvant by activating dendritic cells through stimulation of TLR4.

Dendritic cell (DC) based cancer vaccines represent a promising immunotherapeutic strategy against cancer. To enhance the modest immunogenicity of DC vaccines, various adjuvants are often incorporated. Particularly, most of the common adjuvants are derived from bacteria. In the current study, we evaluate the use of a human pancreatic cancer derived protein, pancreatic adenocarcinoma upregulated factor (PAUF), as a novel DC vaccine adjuvant. We show that PAUF can induce activation and maturation of DCs and activate NFkB by stimulating the Toll-like receptor signaling pathway. Furthermore, vaccination with PAUF treated DCs pulsed with E7 or OVA peptides leads to generation of E7 or OVA-specific CD8+ T cells and memory T cells, which correlate with long term tumor protection and antitumor effects against TC-1 and EG.7 tumors in mice. Finally, we demonstrated that PAUF mediated DC activation and immune stimulation are dependent on TLR4. Our data provides evidence supporting PAUF as a promising adjuvant for DC based therapies, which can be applied in conjunction with other cancer therapies. Most importantly, our results serve as a reference for future investigation of human based adjuvants.