Approach For Treatment Of Pancreatic Cancer Research Articles

Umbelliprenin induces autophagy and apoptosis while inhibits cancer cell stemness in pancreatic cancer cells.

Umbelliprenin is a sesquiterpene coumarin isolated from Artemisia absinthium L. and shows antitumor effects in various cancers by inducing apoptosis. However, the antitumor effect of umbelliprenin in human pancreatic cancer has not been clarified. The antitumor effects were determined by MTT and AnnexinV/PI double staining assay in vitro and xenograft mice in vivo. Autophagy was determined via immunofluorescence analysis. Apoptotic or autophagic related proteins were measured by immunoblotting. The pancreatic cancer cell stemness were determined by mammosphere formation and ALDEFLUOR assay. It revealed that umbelliprenin inhibited pancreatic cancer cell proliferation in vitro and pancreatic cancer tumor growth in vivo. Moreover, umbelliprenin induced pancreatic cancer cell BxPC3 apoptosis and autophagy as evidenced by upregulated apoptosis and autophagy- related protein expression (p < 0.01). Blocking autophagy by 3-MA or Atg7 knockout enhanced umbelliprenin-induced apoptosis (p < 0.05). Umbelliprenin also reduced pancreatic cancer cell stemness by reducing Oct4, Nanog, and Sox2 mRNA levels (p < 0.01). Mechanistically, umbelliprenin greatly inhibited Akt/mTOR and Notch1 signal pathway. Umbelliprenin may be a novel therapeutic approach for pancreatic cancer treatment.

Targeting KRASG12V mutations with HLA class II-restricted TCR for the immunotherapy in solid tumors.

KRAS mutation is a significant driving factor of tumor, and KRASG12V mutation has the highest incidence in solid tumors such as pancreatic cancer and colorectal cancer. Thus, KRASG12V neoantigen-specific TCR-engineered T cells could be a promising cancer treatment approach for pancreatic cancer. Previous studies had reported that KRASG12V-reactive TCRs originated from patients' TILs could recognized KRASG12V neoantigen presented by specific HLA subtypes and remove tumor persistently in vitro and in vivo. However, TCR drugs are different from antibody drugs in that they are HLA-restricted. The different ethnic distribution of HLA greatly limits the applicability of TCR drugs in Chinese population. In this study, we have identified a KRASG12V-specific TCR which recognized classII MHC from a colorectal cancer patient. Interestingly, we observed that KRASG12V-specific TCR-engineered CD4+ T cells, not CD8+ T cells, demonstrated significant efficacy in vitro and in xenograft mouse model, exhibiting stable expression and targeting specificity of TCR when co-cultured with APCs presenting KRASG12V peptides. TCR-engineered CD4+ T cells were co-cultured with APCs loaded with neoantigen, and then HLA subtypes were identified by the secretion of IFN-γ. Collectively, our data suggest that TCR-engineered CD4+ T cells can be used to target KRASG12V mutation presented by HLA-DPB1*03:01 and DPB1*14:01, which provide a high population coverage and are more suitable for the clinical transformation for Chinese, and mediate tumor killing effect like CD8+ T cells. This TCR hold promise for precision therapy in immunotherapy of solid tumors as an attractive candidate.

Exosomal miR-485-3p derived from pancreatic ductal epithelial cells inhibits pancreatic cancer metastasis through targeting PAK1.

Cell competition is an important feature in pancreatic cancer (PC) progression, but the underlying mechanism remains elusive. This study aims to explore the role of exosomes derived from normal pancreatic ductal epithelial cells involved in PC progression. PC cells and pancreatic stellate cells (PSCs) were treated with exosomes isolated from pancreatic ductal epithelial cells. Cell proliferation was assessed by CCK8 assays. Cell migration and invasion were assessed by Transwell assays. PC and matched adjacent non-tumor tissue specimens were obtained from 46 patients pathologically diagnosed with PC at Peking University First Hospital from 2013 to 2017. Tissue miR-485-3p and p21-activated kinase-1 (PAK1) expression was examined by real-time polymerase chain reaction (RT-PCR), and the relationship of the two was analyzed using Pearman's product-moment correlation. The clinical significance of miR-485-3p was analyzed using the Chi-square test, Wilcoxon rank-sum test, and Fisher exact probability, respectively. The binding of miR-485-3p to PAK1 5'-untranslated region (5'-UTR) was examined by luciferase assay. PC cells were xenografted into nude mice as a PC metastasis model. Exosomes from pancreatic ductal epithelial cells suppressed PC cell migration and invasion as well as the secretion and migration of PSCs. MiR-485-3p was enriched in the exosomes of pancreatic ductal epithelial cells but deficient in those of PC cells and PSCs, in accordance with the lower level in PSCs and PC cells than that in pancreatic ductal cells. And the mature miR-485-3p could be delivered into these cells by the exosomes secreted by normal pancreatic duct cells, to inhibit PC cell migration and invasion. Clinical data analysis showed that miR-485-3p was significantly decreased in PC tissues (P < 0.05) and was negatively associated with lymphovascular invasion (P = 0.044). As a direct target of miR-485-3p, PAK1 was found to exert an inhibitory effect on PC cells, and there was a significantly negative correlation between the expression levels of miR-485-3p and PAK1 (r = -0.6525, P < 0.0001) in PC tissues. Moreover, miR-485-3p could suppress PC metastasis in vivo by targeting p21-activated kinase-1. Exosomal miR-485-3p delivered by normal pancreatic ductal epithelial cells into PC cells inhibits PC metastasis by directly targeting PAK1. The restoration of miR-485-3p by exosomes or some other vehicle might be a novel approach for PC treatment.

Abstract 3950: Targeting ribosome biogenesis is a novel strategy to suppress the growth of pancreatic cancer

Abstract Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States with limited therapeutic approaches. Dysregulation of the ribosome biogenesis process was observed in various cancer including pancreatic cancer. Therefore, strategically targeting ribosome biogenesis could be a novel approach for pancreatic cancer treatment. One such approach is to target ribosome biogenesis is via small molecule inhibitors of RNA Polymerase I as these inhibitors have shown promising anti-cancer activity in pre-clinical and clinical studies. We observed differential constitutive expression of various ribosomal proteins including RPA-194 in human PanCa cells when compared with normal HPDE cells. Therefore, we hypothesized that targeting RNA pol I will inhibit the growth of pancreatic cancer. In this study, we for the first time evaluated the therapeutic effect of a novel RNA polymerase I inhibitor (BMH-21) against PanCa in pre-clinical model systems. BMH-21 significantly inhibited the ribosome biogenesis process in various pancreatic cancer cells (Panc-1, AsPC1, BxPC3, MiaPaCa-2) as determined by inhibition of rRNA synthesis and POL I occupancy on rDNA. BMH-21 treatment of pancreatic cancer cells significantly degraded RPA194 protein as determined by Western blot and confocal microscopy analysis. BMH-21 treatment (0.25-5µM) showed differential IC50 in various pancreatic cancer cells which were correlated with the expression of its target proteins RPA194 and RPA135 expression. In our flow cytometry experiment, we observed a significant G0/G1 cell cycle arrest and increase Annexin V and Annexin V7-AAD positive cells in BMH-21 treated pancreatic cancer cells as compared to the vehicle treatment group suggesting its apoptosis-inducing potential in pancreatic cancer cells. BMH-21 treatment inhibited growth and metastatic phenotypes of various PanCa cells as analyzed by various functional assays (colony formation and atomic force microscopy analyses). We also evaluated the effect of BMH-21 on various kinases, which regulate ribosome biogenesis. Interestingly, we observed BMH-21 significantly (P&amp;lt;0.01) downregulated the phosphorylation of AKT (Ser473) and WNK-1 (Thr60) kinases and Stat3 phosphorylation at Ser727 and upregulates pChk2 kinase in PanCa cells. BMH-21 (2 mg/kg i.p) significantly (P&amp;lt;0.01) inhibited the growth of pancreatic tumor in an orthotopic xenograft mouse model. Excised tumor tissues of BMH-21 treated mice showed decreased expression of various ribosomal proteins including RPA194 and RPA195 along with various cell proliferative markers (ki67 and PCNA) as compared to vehicle-treated group. Taken together, our results demonstrated that targeting the ribosome biogenesis process is a novel therapeutic strategy for the management of pancreatic cancer and BMH-21 could be used as a potential therapeutic agent for the treatment of advanced pancreatic cancer. Citation Format: Carlos Perez, Mudassier Ahmad, Andrew Massey, Asif Shahriar, Emmanuel Anning, Vivek Kashyap, Neeraj Chauhan, Anupam Dhasmana, Manish Tripathi, Subhash Chauhan, Bilal Hafeez. Targeting ribosome biogenesis is a novel strategy to suppress the growth of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3950.

Evaluation of a Combination of an HDAC Inhibitor and a Cell Cycle Inhibitor in Pancreatic Cancer Cells

Pancreatic cancer is one of the deadliest cancers with 5‐year survival rate of ~ 10 percent. Late diagnosis, early metastasis, and resistance to therapeutics necessitate a better treatment approach for pancreatic cancer. Alterations in epigenetic profile through DNA and histone modifications enable tumor growth and metastasis. Evading the control of growth suppressors that regulate cell cycle is also a major hallmark of cancer pathophysiology. We aimed to study a combination therapeutic targeting histone deacetylase (HDAC) and key cell cycle regulator cyclin‐dependent kinase (CDK) in pancreatic cancer. We used panobinostat, a pan‐HDAC inhibitor approved for multiple myeloma and abemaciclib, an FDA‐approved CDK4/6 inhibitor for breast cancer. Our preliminary in vitro data in pancreatic cancer cells depicts synergistic cytotoxicity when treated in combination. In addition, combination treatment resulted in a significant decrease in proliferation and clonogenic survival of pancreatic cancer cells. Our mechanistic studies on the effects of this potent combination on histone modifications, gene expression, and cell cycle regulation will provide insights on drug synergy in pancreatic cancer cells. The results of our in vitro studies show that combining drugs that pharmacologically target two critical aspects of pancreatic cancer proliferation has a high potential for treating this lethal disease and as such merits further investigation.

Advances in Targeted Therapy and Immunotherapy for Pancreatic Cancer.

Pancreatic cancer is a highly aggressive malignancy with an overall 5-year survival rate of <6%due to therapeutic resistance and late-stage diagnosis. These statistics have not changed despite 50 years of research and therapeutic development. Pancreatic cancer is predicted to become the second leading cause of cancer mortality by the year 2030. Currently, the treatment options for pancreatic cancer are limited. This disease is usually diagnosed at a late stage, which prevents curative surgical resection. Chemotherapy is the most frequently used approach for pancreatic cancer treatment and has limited effects. In many other cancer types, targeted therapy and immunotherapy have made great progress and have been shown to be very promising prospects; these treatments also provide hope for pancreatic cancer. The need for research on targeted therapy and immunotherapy is pressing due to the poor prognosis of pancreatic cancer, and in recent years, there have been some breakthroughs for targeted therapy and immunotherapy in pancreatic cancer. This review summarizes the current preclinical and clinical studies of targeted therapy and immunotherapy for pancreatic cancer and ends by describing the challenges and outlook.

Author Correction: Combination of ERK and autophagy inhibition as a treatment approach for pancreatic cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Remodeling tumor immune microenvironment via targeted blockade of PI3K-γ and CSF-1/CSF-1R pathways in tumor associated macrophages for pancreatic cancer therapy

Immunotherapy has exhibited great potential in cancer treatment. However, for immunosuppressive tumors such as pancreatic cancer, immunotherapy is far from satisfactory. PI3K-γ and colony stimulating factor-1/colony stimulating factor-1 receptor (CSF-1/CSF-1R) pathways are involved in the infiltration and polarization of immunosuppressive cells including M2 tumor associated macrophages (M2 TAMs), causing a suppressive tumor immune microenvironment (TIME) in pancreatic cancer. Herein, a M2 TAM targeting nanomicelle was developed to co-deliver PI3K-γ inhibitor NVP-BEZ 235 and CSF-1R-siRNA for specific TAMs reprogramming and antitumor immune responses activation. M2 TAM targeting peptide M2pep was modified on a mixed micelle, which was potent to co-encapsulate BEZ 235 and CSF-1R siRNA. The formulated nanomicelle increased M2 TAM targeting efficiency both in vitro and in vivo. Compared with single pathway blockade, dual blockade of PI3k-γ and CSF-1R demonstrated enhanced TAM remodeling effects by reducing M2 TAM level and elevating M1 TAM level, and also suppressed tumor infiltration of myeloid-derived suppressor cells (MDSCs). Consequently, the M2 TAM targeting reprogramming system activated antitumor immune responses and achieved enhanced anti-pancreatic tumor effects via PI3K-γ blockade and downregulation of CSF-1R. The M2pep modified nanomicelle provides a promising method for co-delivery of siRNA and small molecule inhibitor to M2 TAM. Dual inhibition of both PI3K-γ and CSF-1R can remodel TIME and activate antitumor immune responses synergistically, providing an alternative approach for pancreatic cancer treatment.

Combination of ERK and autophagy inhibition as a treatment approach for pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by KRAS- and autophagy-dependent tumorigenic growth, but the role of KRAS in supporting autophagy has not been established. We show that, to our surprise, suppression of KRAS increased autophagic flux, as did pharmacological inhibition of its effector ERK MAPK. Furthermore, we demonstrate that either KRAS suppression or ERK inhibition decreased both glycolytic and mitochondrial functions. We speculated that ERK inhibition might thus enhance PDAC dependence on autophagy, in part by impairing other KRAS- or ERK-driven metabolic processes. Accordingly, we found that the autophagy inhibitor chloroquine and genetic or pharmacologic inhibition of specific autophagy regulators synergistically enhanced the ability of ERK inhibitors to mediate antitumor activity in KRAS-driven PDAC. We conclude that combinations of pharmacologic inhibitors that concurrently block both ERK MAPK and autophagic processes that are upregulated in response to ERK inhibition may be effective treatments for PDAC.

Abstract 3878: Drug-loaded microparticles as a treatment approach for pancreatic cancer

Abstract Pancreatic cancer is the fourth leading cause of cancer death in the United States with only 7% of diagnosed patients surviving 5 years. Most pancreatic cancer patients are not surgical candidates due to advanced stage at diagnosis. Also, current systemic chemotherapies have not been very effective at decreasing tumor burden. Poly(lactic-co-glycolic acid)-based (PLGA) microparticles (MPs) are a promising tool for localized drug delivery within the tumor due to their biocompatibility, flexibility in drug encapsulation and extended drug release. The present study investigated whether gemcitabine-loaded microparticles (GMPs), paclitaxel-loaded microparticles (PMPs) or sequential treatment of both, in comparison with blank (no drug) MPs, systemic treatments and no treatment control, are able to promote cancer cell killing effects and modulate drug resistance in vitro and in vivo. We previously showed in vitro studies with PANC-1 cells and we were able to complete the MPs studies with a second human pancreatic cancer cell line, MIAPaCa-2. In both cases, we tested the effect of single and combination treatments on two well-known resistance markers for gemcitabine, ribonucleotide reductase catalytic subunit M1 and cytidine deaminase, as well as on the promotion of cell death measuring cleaved caspase-3 (CC3). When treated with GMPs alone, both markers went up suggesting an increase in resistance against gemcitabine. Interestingly, both cell lines treated with PMPs alone showed an increase in CC3 expression and a significant decrease in the expression of both markers. Subsequently, we tested the in vivo efficacy of MPs by direct injection into established subcutaneous MIAPaCa-2 tumors in nude mice. Following four weeks of treatment, the tumors were excised, biopsied for protein analysis and frozen in OCT to allow visualization of fluorescent MPs and detect apoptosis by immunofluorescence. We also want to evaluate reactive oxygen species production; where we expect to see an increase in the MPs treated groups. This analysis is in progress. In conclusion, we observed a decrease in cell viability and drug resistance proteins in vitro using the drug-loaded microparticles in two grade 3 (or high grade) pancreatic cancer cell lines. The described drug delivery method has the potential to be a more efficient treatment modality than systemic gemcitabine and paclitaxel against early stage and locally advanced pancreatic cancer. Citation Format: Maria Munoz-Sagastibelza, Oluwafeyikemi Okome, Jenny E. Paredes Sanchez, Albert Palileo, Catherine Burkhart, Laura Martello-Rooney. Drug-loaded microparticles as a treatment approach for pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3878.

Targeted dianthin is a powerful toxin to treat pancreatic carcinoma when applied in combination with the glycosylated triterpene SO1861.

Targeted cancer therapy provides the basis for the arrest of tumor growth in aggressive pancreatic carcinoma; however, a number of protein‐based targeted toxins lack efficacy due to insufficient endosomal escape after being endocytosed. Therefore, we tested a fusion protein of the ribosome‐inactivating protein dianthin and human epidermal growth factor in combination with a glycosylated triterpene (SO1861) that serves as an endosomal escape enhancer. In vitro investigations with the pancreatic carcinoma cell lines BxPC‐3 and MIA PaCa‐2 revealed no significant differences to off‐target cells in the half maximal inhibitory concentration (IC 50) for the fusion protein. In contrast, combination with SO1861 decreased the IC 50 for BxPC‐3 cells from 100 to 0.17 nm, whereas control cells remained unaffected. Monotherapy of BxPC‐3 xenografts in CD‐1 nude mice led to a 51.7% average reduction in tumor size (40.8 mm3) when compared to placebo; however, combined treatment with SO1861 resulted in a more than 13‐fold better efficacy (3.0 mm3 average tumor size) with complete regression in 80% of cases. Immunohistochemical analyses showed that tumor cells with lower target receptor expression are, in contrast to the combination therapy, able to escape from the monotherapy, which finally results in tumor growth. At the effective concentration, we did not observe liver toxicity and saw no other side effects with the exception of a reversible skin hardening at the SO1861 injection site, alongside an increase in platelet counts, plateletcrit, and platelet distribution width. In conclusion, combining a targeted toxin with SO1861 is proven to be a very promising approach for pancreatic cancer treatment.

HIC1 attenuates invasion and metastasis by inhibiting the IL-6/STAT3 signalling pathway in human pancreatic cancer

Hypermethylated in cancer 1 (HIC1) is a tumour suppressor gene that is frequently deleted or epigenetically silenced in many human cancers. However, the molecular function of HIC1 in pancreatic cancer has not been fully elucidated, especially in cancer invasion and metastasis. We aimed to clarify the clinical relevance of HIC1 and human pancreatic cancer and the mechanism of its effect on invasion and metastasis .HIC1 was downregulated in pancreatic cancer patient cancer tissue and pancreatic cancer cell lines. A tissue microarray analysis demonstrated that negative HIC1 expression predicted advanced pathological stages and worse patient survival. In addition, HIC1 inhibited the invasion and metastasis of pancreatic cancer cells both in vitro and in vivo. Finally, HIC1 repressed the expression of STAT3 target genes, including c-Myc, VEGF, CyclinD1, MMP2 and MMP9, by binding and interacting with STAT3 to impede its DNA-binding ability but without affecting the protein levels of STAT3 and p-STAT3. Therefore, HIC1 appears to function as a STAT3 inhibitor and may be a promising target for cancer research and for the development of an optimal treatment approach for pancreatic cancer.

Ferulic acid decreases cell viability and colony formation while inhibiting migration of MIA PaCa-2 human pancreatic cancer cells in vitro

Novel and combinatorial treatment methods are becoming sought after entities in cancer treatment and these treatments are even more valuable for pancreatic cancer. The scientists are always on the lookout for new chemicals to help them in their fight against cancer. In this study, we examine the effects of ferulic acid (FA), a phenolic compound, on gene expression, viability, colony formation and migration/invasion in the cultured MIA PaCa-2 human pancreatic cancer cell. Cytotoxic effects of FA were determined by using trypan blue dye exclusion test and Cell TiterGlo (CTG) assay. IC50 dose in MIA PaCa-2 cells was detected as 500μM/ml at the 72nd hour. Expression profiles of certain cell cycle and apoptosis genes such as CCND1 (cyclin D1),CDK4, CDK6, RB, p21, p16, p53, caspase-3, caspase-9, caspase-8, caspase-10, Bcl-2, BCL-XL,BID, DR4,DR5,FADD,TRADD,PARP, APAF, Bax, Akt, PTEN, PUMA, NOXA, MMP2, MMP9, TIMP1 and TIMP2 were determined by real-time PCR. The effect of FA on cell viability was determined by CellTiter-Glo® Luminescent Cell Viability Assay. Additionally, effects of FA on colony formation and invasion were also investigated. It was observed that FA caused a significant decrease in the expression of CCND1, CDK 4/6, Bcl2 and caspase 8 and 10 in the MIA PaCa-2 cells while causing an increase in the expression of p53, Bax, PTEN caspase 3 and 9. FA was observed to decrease colony formation while inhibiting cell invasion and migration as observed by the BioCoat Matrigel Invasion Chamber guide and colony formation assays. In conclusion, FA is thought to behave as an anti-cancer agent by affecting cell cycle, apoptotic, invasion and colony formation behavior of MIA PaCa-2 cells. Therefore, FA is placed as a strong candidate for further studies aimed at finding a better, more effective treatment approach for pancreatic cancer.

Abstract 2714: A multi-targeted approach for pancreatic cancer treatment by a novel cucurbitacin analogue

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in United States. Tremendous efforts have witnessed the failure of many chemotherapeutic regimens and the current standard-of-care therapy, gemcitabine (GEM), extends patient survival by only a few weeks. Numerous studies implicate the need for the drugs that can target multiple signaling events in pancreatic cancer. Recently, cucurbitacins, tetracyclic triterpenoid compund/molecules, belonging to a family of Cucurbitaceae have shown promising anti-cancer activities such as antiproliferation, cell cycle arrest, and apoptosis induction. Here, we report the anticancer activity of a novel analogue of cucurbitacin (Cuc D) that is able to target important signaling proteins involved in pancreatic cancer cell proliferation, invasion and metastasis. Methods: Herein, we investigated the use of Cuc D for the treatment of pancreatic cancer using a panel of pancreatic cancer cells. The effect of Cuc D on the growth of pancreatic cancer cells was determined by CellTiter 96® AQueous One Solution cell proliferation assay using six pancreatic cancer (MiaPaCa-2, CaPan-1, HPAF-II, Panc-1, BxPC-3 and AsPc-1) cells. Cell growth kinetic assay was carried out at 24, 48, 72 and 96h. The clonogenic potential of cancer cells was also studied using the colony formation assay. microRNA-21 expression levels were investigated through Real-time PCR. Immunoblotting techniques were performed to determine the effects of Cuc D at the molecular level. Results: Our results indicate the anticancer effects of Cuc D in pancreatic cancer cells. Cuc D induces concentration dependent inhibition of cell proliferation in a panel of gemcitabine sensitive/resistant pancreatic cancer cell lines at nano molar concentrations. It also inhibits colony formation and metastasis potential of pancreatic cancer cells in dose and time dependent manner. Importantly, Cuc D targets and inhibits proteins, MUC13, Bcl2 and survivin (inhibitor of apoptosis protein family member: IAP) that are involved in proliferation, metastasis and tumor progression as seen through Western blotting. Additionally, the treatment of Cuc D induces the phosphorylation of p53 (p-p53; ser-15) in pancreatic cancer cells. We also observed that Cuc D effectively inhibits miR-21 levels in pancreatic cancer, HPAF-II cells as seen through Real time PCR analysis. miR-21 is an oncogenic miRNA that is overexpressed in pancreatic cancer. Conclusion: Our findings demonstrate that Cuc D exerts multi-focal action in pancreatic cancer cells targeting multiple signaling events. Overall, this study suggests that Cuc D can be a potential and promising therapeutic modality for pancreatic cancer treatment. Citation Format: Mohammed Sikander, Mohd Saif Zaman, Neeraj Chauhan, Murali M. Yallapu, Sheema Khan, Fathi T. Halaweish, Bhavin Chauhan, Meena Jaggi, Subhash C. Chauhan. A multi-targeted approach for pancreatic cancer treatment by a novel cucurbitacin analogue. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2714. doi:10.1158/1538-7445.AM2014-2714

Antiprotease strategy in combination with gemcitabine as a putative novel therapeutic approach for pancreatic cancer treatment

Antiprotease strategy in combination with gemcitabine as a putative novel therapeutic approach for pancreatic cancer treatment

Anti-DLL4 Has Broad Spectrum Activity in Pancreatic Cancer Dependent on Targeting DLL4-Notch Signaling in Both Tumor and Vasculature Cells

We previously showed that targeting Delta-like ligand 4 (DLL4) in colon and breast tumors inhibited tumor growth and reduced tumor initiating cell frequency. In this report, we have extended these studies to pancreatic cancer and probed the mechanism of action in tumor and stromal cells involved in antitumor efficacy. Patient-derived pancreatic xenograft tumor models were used to evaluate the antitumor effect of anti-DLL4. To investigate the mechanism of action, we compared the activity of targeting DLL4 in tumor cells with an anti-human DLL4 antibody (anti-hDLL4) and in the host stroma/vasculature with an anti-mouse DLL4 antibody (anti-mDLL4). The effect of these antibodies on cancer stem cell frequency was examined by in vivo limiting dilution assays. The combination of anti-hDLL4 and anti-mDLL4 was efficacious in a broad spectrum of pancreatic tumor xenografts and showed additive antitumor activity together with gemcitabine. Treatment with either anti-hDLL4 or anti-mDLL4 delayed pancreatic tumor recurrence following termination of gemcitabine treatment, and the two together produced an additive effect. Anti-hDLL4 had a pronounced effect in reducing the tumorigenicity of pancreatic cancer cells based on serial transplantation and tumorsphere assays. In contrast, disruption of tumor angiogenesis with anti-mDLL4 alone or with anti-VEGF had minimal effects on tumorigenicity. Gene expression analyses indicated that anti-DLL4 treatment regulated genes that participate in Notch signaling, pancreatic differentiation, and epithelial-to-mesenchymal transition. Our findings suggest a novel therapeutic approach for pancreatic cancer treatment through antagonism of DLL4/Notch signaling.

Targeting the Cancer-Stroma Interaction: A Potential Approach for Pancreatic Cancer Treatment

Recent studies have demonstrated that the interaction between the cancer and the stroma, play a key role in the development of pancreatic cancer. The desmoplasia, which consists of fibroblasts, pancreatic stellate cells, lymphatic and vascular endothelial cells, immune cells, pathologic increased nerves, and the extracellular matrix (ECM), creates a complex tumor microenvironment that promotes pancreatic cancer development, invasion, metastasis, and resistance to chemotherapy. Thus, the potential approach for targeting the components of this desmoplastic reaction or the pancreatic tumor microenvironment might represent a novel therapeutic approach to advanced pancreatic carcinoma. Novel therapies that target on the pancreatic tumor microenvironment should become one of the more effective treatments for pancreatic cancer.

Targeting the RAS Pathway – A New Approach for Pancreatic Cancer Treatment

Targeting the RAS Pathway – A New Approach for Pancreatic Cancer Treatment

Parthenolide induces proliferation inhibition and apoptosis of pancreatic cancer cells in vitro

BackgroundTo explore the anti-tumor effects of parthenolide in human pancreatic cancer.MethodsBxPC-3 cell, a human pancreatic cancer, was treated with parthenolide at different concentrations. The MTT assay was used to analyze cell viability. Flow cytometry and DNA fragmentation analysis were applied to evaluate apoptosis after parthenolide treatment. The wound closure and cell invasion assay were also employed in the study. Western blotting was used to demonstrate Bad, Bcl-2, Bax, caspase-9 and pro-caspase-3 expression.ResultsThe MTT assay indicated that the pancreatic cancer growth could be dose-dependently inhibited by parthenoolide. This phenomenon was confirmed by flow cytometry and DNA fragmentation analysis. The wound closure assay and cell invasion assay showed that BxPC-3 cell was significantly suppressed by parthenolide at 7.5 μM and 15 μM. Western Blotting demonstrated the Bcl-2 and pro-caspase-3 were down-regulated while the Bax and caspase-9 were up-regulated. No alteration in Bad expression was found after treatment.ConclusionsThe parthenolide can inhibit the cell growth, migration, and induce the apoptosis in human pancreatic cancer. These findings may provide a novel approach for pancreatic cancer treatment.

1025. Efficiency, Specificity and Efficacy of Genetically-Modified Adenovirus Vector on Peritoneal Cancers

Pancreatic cancer is one of the most lethal of all major malignancies. Although pancreatic cancer only accounts for 2% of all newly diagnosed cancers in the US, annually it is responsible for 5% of cancer deaths. We are developing a treatment approach for pancreatic cancer based on the oncolytic properties of the attenuated Edmonston strain of measles virus. While MV-Edm does not cause disease in humans it can infect cells through CD46 and SLAM receptors causing cell fusion forming multi-nucleated syncytia that eventually die via apoptosis. We have demonstrated this cytopathic effect in vitro on a panel of human pancreatic cancer cell lines (BxPC-3, L3.6pl, Panc-1, SU.86.86, MiaPaCa). We have further demonstrated the efficacy of this virus in vivo with a subcutaneous tumor model of the BxPC-3 cells. Mice treated with intra-tumoral MV-therapy out-lived the control group with a median survival ratio of 1.62 (p=0.0046). To further enhance the ability of the measles virus to more specifically target pancreatic cancer cells we developed a strategy for display of scFvs by fusion to the C-terminus of the viral attachment protein H. We have recently reported the identification of mutations in MV-H that ablate CD46 and SLAM binding (481A, 533A). Using this ablated platform we subcloned the HAA displaying human anti-CD38 or anti-EGFR scFv into full length MV-eGFP and successfully rescued these viruses. The MV-GFP-HAA αEGFR virus is an exceptional therapeutic agent for pancreatic cancer because of the over expression of EGFR on these tumor cells. As a specificity control, we have used a virus displaying a scFv against CD38, a myeloma antigen. The tropisms of the new viruses were compared against the parental MV-eGFP virus on a panel of receptor positive and negative cell lines to test the accuracy and efficiency of virus-cell entry and cell-to-cell fusion. These viruses were also characterized by western blot to confirm the chimeric H-protein. When these EGFR retargeted viruses are used to infect the pancreatic cancer cell line BxPC-3 we are able to show slightly greater levels of transduction to that observed with the parent virus that enters through CD46 and SLAM. These retargeted viruses will have the significant therapeutic advantage of binding and killing only tumor cells displaying the appropriate receptor.