PaCa-2 Pancreatic Cancer Cell Lines Research Articles

The marine natural product Scalarin inhibits the receptor for advanced glycation end products (RAGE) and autophagy in the PANC-1 and MIA PaCa-2 pancreatic cancer cell lines.

Pancreatic cancer, the fourth leading cause of cancer death in the United States, has a negative prognosis because metastasis occurs before symptoms manifest. Although combination therapies are showing improvements in treatment, the survival rate for pancreatic cancer five years post diagnosis is only 8%, stressing the need for new treatments. The receptor for advanced glycation end products (RAGE) has recently emerged as a chemotherapeutic target in KRAS driven pancreatic cancers both for treatment and in chemoprevention. RAGE appears to be an important regulator of inflammatory, stress and survival pathways that lead to carcinogenesis, resistance to chemotherapy, enhanced proliferation and the high metastatic potential of pancreatic cancer. RAGE expression has been demonstrated in pancreatic cancer tumors but not in adjacent epithelial tissues. Its presence is associated with increased proliferation and metastasis. In an effort to identify novel inhibitors of RAGE among our collection of marine-derived secondary metabolites, a cell-based screening assay utilizing flow cytometry was developed. This effort led to the identification of scalarin as the active compound in a marine sponge identified as Euryspongia cf. rosea. Scalarin is a sesterterpene natural product isolated previously from a different marine sponge. Scalarin reduces the levels of RAGE and inhibits autophagy in the PANC-1 and MIA PaCa-2 pancreatic cancer cell lines. Its IC50 for cytotoxicity ranges between 20 and 30μM in the AsPC-1, PANC-1, MIA PaCa-2 and BxPC-3 pancreatic cancer cell lines. Inhibition of autophagy limits tumor growth and tumorigenesis in pancreatic cancer, making scalarin an interesting compound that may merit further study.

Functional relationship of PMCA4 and glycolytic enzyme in MIA PaCa-2 pancreatic cancer cell line

Functional relationship of PMCA4 and glycolytic enzyme in MIA PaCa-2 pancreatic cancer cell line

In vitro and in vivo cytotoxicity of troglitazone in pancreatic cancer

BackgroundTroglitazone (TGZ) is a peroxisome proliferator-activated receptor gamma (PPARγ) agonist that has been investigated as a potential chemopreventive and chemotherapeutic agent. However, the antitumor efficacy and mechanisms of TGZ in pancreatic cancer have not been extensively investigated. This study was performed to investigate the in vitro and in vivo effects of TGZ against pancreatic cancer cell lines, as well as its action mechanisms in terms of PPARγ dependency and the Akt and mitogen-activated protein kinase (MAPK) pathways. We also evaluated the effects of TGZ on cell invasion and migration.MethodsMIA Paca2 and PANC-1 human pancreatic cancer cell lines were used. Cell viability and caspase-3 activity were detected using fluorescent reagents, and chromatin condensation was observed after staining the cells with Hoechst 33342. Protein expression levels were detected by western blot analysis. Invasion and migration assays were performed using 24-well chambers. The in vivo antitumor effects of TGZ were investigated in nude mice inoculated with MIA Paca2 cells. Mice were orally administered TGZ (200 mg/kg) every day for 5 weeks, and tumor volumes were measured bi-dimensionally.ResultsTGZ showed dose-dependent cytotoxicity against both cell lines, which was not attenuated by a PPARγ inhibitor. Further, TGZ induced chromatin condensation, elevated caspase-3 activity, and increased Bax/Bcl-2 relative expression in MIA Paca2 cells. TGZ also increased phosphorylation of Akt and MAPK (ERK/p38/JNK) in both cell lines, and a JNK inhibitor significantly increased the viability of MIA Paca2 cells. TGZ moderately inhibited cell migration. Tumor growth in the MIA Paca2 xenograft model was inhibited by TGZ administration, while mouse body weights in the treated group were not different from those of the vehicle administration group.ConclusionWe demonstrated for the first time the in vivo antitumor effects of TGZ in pancreatic cancer without marked adverse effects. TGZ induced mitochondria-mediated apoptosis in MIA Paca2 cells, and its cytotoxic effects were PPARγ-independent and occurred via the JNK pathway. Our results indicate that TGZ is a potential approach for the treatment of pancreatic cancer and warrants further studies regarding its detailed mechanisms and clinical efficacy.

Search for KPNA7 cargo proteins in human cells reveals MVP and ZNF414 as novel regulators of cancer cell growth

Karyopherin alpha 7 (KPNA7) belongs to a family of nuclear import proteins that recognize and bind nuclear localization signals (NLSs) in proteins to be transported to the nucleus. Previously we found that KPNA7 is overexpressed in a subset of pancreatic cancer cell lines and acts as a critical regulator of growth in these cells. This characteristic of KPNA7 is likely to be mediated by its cargo proteins that are still mainly unknown. Here, we used protein affinity chromatography in Hs700T and MIA PaCa-2 pancreatic cancer cell lines and identified 377 putative KPNA7 cargo proteins, most of which were known or predicted to localize to the nucleus. The interaction was confirmed for two of the candidates, MVP and ZNF414, using co-immunoprecipitation, and their transport to the nucleus was hindered by siRNA based KPNA7 silencing. Most importantly, silencing of MVP and ZNF414 resulted in marked reduction in Hs700T cell growth. In conclusion, these data uncover two previously unknown human KPNA7 cargo proteins with distinct roles as novel regulators of pancreatic cancer cell growth, thus deepening our understanding on the contribution of nuclear transport in cancer pathogenesis.

ImmunoPET Imaging of Insulin-Like Growth Factor 1 Receptor in a Subcutaneous Mouse Model of Pancreatic Cancer.

The role of insulin-like growth factor-1 receptor (IGF-1R) in cancer tumorigenesis was established decades ago, yet there are limited studies evaluating the imaging and therapeutic properties of anti-IGF-1R antibodies. Noninvasive imaging of IGF-1R may allow for optimized patient stratification and monitoring of therapeutic response in patients. Herein, this study reports the development of a Zirconium-89 (89Zr)-labeled anti-IGF-1R antibody (89Zr-Df-1A2G11) for PET imaging of pancreatic cancer. Successful chelation and radiolabeling of the antibody resulted in a highly stable construct that could be used for imaging IGF-1R expressing tumors in vivo. Western blot and flow cytometry studies showed that MIA PaCa-2, BxPC-3, and AsPC-1 pancreatic cancer cell lines expressed high, moderate, and low levels of IGF-1R, respectively. These three pancreatic cancer cell lines were subcutaneously implanted into mice. By employing the PET imaging technique, the tumor accumulation of 89Zr-Df-1A2G11 was found to be dependent on the level of IGF-1R expression. Tumor accumulation of 89Zr-Df-1A2G11 was 8.24 ± 0.51, 5.80 ± 0.54, and 4.30 ± 0.42 percentage of the injected dose (%ID/g) in MIA PaCa-2, BxPC-3, and AsPC-1-derived tumor models at 120 h postinjection, respectively (n = 4). Biodistribution studies and ex vivo immunohistochemistry confirmed these findings. In addition, 89Zr-labeled nonspecific human IgG (89Zr-Df-IgG) displayed minimal uptake in IGF-1R positive MIA PaCa-2 tumor xenografts (3.63 ± 0.95%ID/g at 120 h postinjection; n = 4), demonstrating that 89Zr-Df-1A2G11 accumulation was highly specific. This study provides initial evidence that our 89Zr-labeled IGF-1R-targeted antibody may be employed for imaging a wide range of malignancies. Antibodies may be tracked in vivo for several days to weeks with 89Zr, which may enhance image contrast due to decreased background signal. In addition, the principles outlined in this study can be employed for identifying patients that may benefit from anti-IGF-1R therapy.

Evaluation of low-dose proton beam radiation efficiency in MIA PaCa-2 pancreatic cancer cell line vitality and H2AX formation

Background and objectiveThe aim of this study was to evaluate the efficiency of proton beam irradiation in pancreatic cancer cell line MIA PaCa-2 and its role in the cell cycle, apoptosis, and formation of histone γH2AX in different reparation times (72-h follow-up). Material and methodsThe MIA PaCa-2 pancreatic carcinoma cell line was irradiated with 1.6-Gy proton beam. After irradiation, cell viability was measured colorimetrically, and the cell cycle, apoptosis, and γH2AX expression were evaluated on a FACScan cytometer. ResultsLow-dose proton beam irradiation had an effect on the MIA PaCa-2 tumor cell line already 1h after exposure, but maximal lethality was reached after 72h postirradiation with a cell viability rate of 24%. The cell cycle went into partial G1/0 arrest, and was released after 72h. The expression of γH2AX was strong and its levels were significantly elevated as late as 48h post radiation. The apoptosis levels increased with post radiation incubation time to reach 79% after 72h. ConclusionsOur data demonstrate that low-doses proton beam irradiation had an effect on MIA PaCa-2 pancreatic carcinoma cell line. Full extent of irradiation had an impact only 24h postirradiation, triggering DNA arrested cell cycle in G1/0 phase. Formed DNA DSBs were found to be repaired via the NHEJ pathway mechanism within 72h. Unsuccessful repaired DSBs induced apoptotic cell death. After 72h reparation processes were completed, and cell cycle was released from arrest in G1/0 phase.

5-Lipoxygenase and cyclooxygenase inhibitory dammarane triterpenoid 1 from Borassus flabellifer seed coat inhibits tumor necrosis factor-α secretion in LPSInduced THP-1 human monocytes and induces apoptosis in MIA PaCa-2 pancreatic cancer cells.

Phospholipase A2 (PLA2), Cyclooxygenase (COX) and 5-Lipoxygenase (5-LOX) are arachidonic acid metabolizing enzymes and their inhibitors have been developed as therapeutic molecules for cancer and inflammation related disorders. In the present study, PLA2, COX 1&2 and 5-LOX inhibitory studies of Borassus flabellifer seed coat extract were carried out and substantial 5-LOX inhibitory activity was found. Dammarane triterpenoid 1 (Dammara-20,23-diene-3,25-diol) was isolated according to 5-LOX activity guided isolation, and screened for COX (1 & 2) inhibitory activities. Dammarane triterpenoid 1 inhibited carrageenan-induced rat paw edema and TNF-α secretion levels in lipopolysaccharide (LPS)-induced THP-1 human monocytes. Anticancer activity studies demonstrated the antiproliferative effect of dammarane triterpenoid 1 on various cancer cell lines including MIA PaCa-2 pancreatic, DU145 prostate, HL-60 leukemia and Caco-2 colon cancers. Dammarane triterpenoid 1 showed good antiproliferative activity on MIA PaCa-2 pancreatic cancer cell line with IC50 of 12.36±0.33 µM, among other tested cell lines. Apoptosis inducing activity of dammarane triterpenoid 1 was confirmed based on increased sub-G0 phase cell population in cell cycle analysis, loss of mitochondrian membrane potential, elevated levels of cytochrome c, nuclear morphological changes and DNA fragmentation in MIA PaCa-2 pancreatic cancer cells. Therefore, dammarane triterpenoid skeleton may raise the hope of developing novel anti-inflammatory and anticancer drugs in the future.

Abstract 1330: The influence of anticancer agents and heat treatment on PD-L1 expression on human and murine pancreatic cancer cell lines

Abstract Background: Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal malignancies. Currently conducted chemotherapy for PDA didn't get the sufficient clinical results, so we need to get new strategy for PDA therapy immediately. For breaking through this situation, the inhibitors of immune checkpoint PD-1/PD-L1 are hopeful candidates because PD-1/PD-L1 inhibitors relatively got the good results for some advanced malignancies including PDA, but the sole therapy doesn't result in good outcome. In murine model, the combination therapy of PD-L1 inhibitor and gemcitabine has been reported to show a synergistic effect on PDA compared to each sole therapy. But the mechanism of the synergistic effect is not well understood. On the other hand, we have previously demonstrated the efficacy of the combined therapy of regional heat treatment and gemcitabine in advanced PDA patients, but the effect of heat treatment on immune checkpoint is also unknown. Then, for future combination therapy of anticancer agents, immune check point inhibitor and heat treatment, we analyzed the influence of some anticancer agents and heat treatment on the expression of PD-L1 on pancreatic cancer cell lines. Methods: Human pancreatic cancer cell lines MIA PaCA-2, AsPC-1 and murine pancreatic cancer cell line Pan02 were used in this study. These cells were adjusted to 1.0 × 105 / ml and incubated with anticancer agents such as gemcitabine, paclitaxel and 5-fluorouracil at 37°C for 24 - 72 hours. For checking the influence of anticancer agents on the expression of PD-L1, their expression of PD-L1 was examined by flow cytometry and qRT-PCR. Next, before exposing cancer cells to gemcitabine, MIA PaCA-2 and AsPC-1 were incubated at 43°C as heat treatment. After the heat treatment, PD-L1 expression was analyzed using flow cytometry. Results: In AsPC-1 and Pan02, PD-L1 expression was enhanced with all three anticancer agents in concentration dependency by both flow cytometry and qRT-PCR. In MIA PaCA-2, PD-L1 expression was enhanced with all three anticancer agents by flow cytometry analysis, but the result of qRT-PCR could not show the difference. PD-L1 expression on MIA PaCA-2 and AsPC-1 with heat treatment was suppressed compared to only anticancer agent treatment. Conclusion: The stimulation of anticancer agents tends to lead to an enhancement of PD-L1 expression on both human and murine pancreatic cancer cell lines. The synergistic effect of PD-L1 inhibitor and gemcitabine has the possibility to be brought about by PD-L1 up-regulation. On the other hand, heat treatment has the possibility to suppress PD-L1 expression and this mechanism might lead to cancel out the immune tolerance caused by anticancer agent administration with up-regulation of PD-L1. For future, we need to further examine the most effective timing and method of combined therapy of anticancer agent, PD-L1 inhibitor and heat treatment. Citation Format: Toshifumi Doi, Tetsuya Okayama, Takeshi Ishikawa, Kaname Oka, Naoyuki Sakamoto, Tomoyo Yasuda, Yuji Naito, Yoshito Itoh. The influence of anticancer agents and heat treatment on PD-L1 expression on human and murine pancreatic cancer cell lines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1330. doi:10.1158/1538-7445.AM2015-1330

The marine natural product microsclerodermin A is a novel inhibitor of the nuclear factor kappa B and induces apoptosis in pancreatic cancer cells.

Pancreatic cancer, the 4th leading cause of cancer death in the US, is highly resistant to all current chemotherapies, and its growth is facilitated by chronic inflammation. An important mediator of inflammation is the nuclear factor kappa B (NFκB), a transcription factor that regulates over 500 genes including the regulation of anti-apoptotic proteins, cell cycle progression and cytokine production. NFκB is constitutively activated in pancreatic cancer cells contributing to their resistance to apoptosis and high metastatic potential. Although many small molecules that inhibit NFκB have been identified, none are currently used in the clinic, perhaps due to their lack of specificity. To identify novel inhibitors of NFκB, the HBOI library of enriched fractions from marine organisms was screened using a reporter cell line that produces luciferin under the transcriptional control of NFκB. Fractions from the sponge Amphibleptula were active in this screen and contained the antifungal cyclic peptide microsclerodermin A. Microsclerodermin A is shown here to inhibit NFκB transcriptional activity in a reporter cell line, to reduce levels of phosphorylated (active) NFκB in the AsPC-1 cell line, to have an IC50 for cytotoxicity in the low micromolar range against the AsPC-1, BxPC-3, MIA PaCa-2 and PANC-1 pancreatic cancer cell lines, and to induce significant apoptosis in the AsPC-1, BxPC-3 and the PANC-1 cell lines. Treatment of AsPC-1 cells with microsclerodermin A also resulted in an increase in IL-8 production without apparent induction of angiogenic factors and there is the possibility that inhibition of NFκB by microsclerodermin A is mediated by the glycogen synthase kinase 3β pathway.

Synthesis, of Novel Piperine Analogs of Dipeptidyl Boronic Acid as Antimicrobial and Anticancer Agents

In the present study three piperine analogs of dipeptidyl boronic acid (1 to 3) were synthesized and evaluated the antimicrobial and anticancer activities. Chemical structures of the synthesized compounds were characterized by 1H, 13C and mass spectral studies. All the compounds were screened for their antineoplastic activity on HeLa cervical, MCF-7 breast and MIA PaCa-2 pancreatic cancer cell lines and antimicrobial activity against seven bacterial and five fungal species. In vitro results showed that most of the compounds displayed moderate to good inhibitory activity on the tested cancer cell lines, among them compound 1 showed good anticancer activity where as Compound 3 was found to be potent antimicrobial agent against Asperigillus fumigates at a concentration of 62 μg/mL than other tested compounds and the parent molecule piperine. All the compounds were subjected to molecular docking studies on Leucyl-tRNA synthase as well as for 20S proteasome inhibition. In silico molecular docking results demonstrated that all compounds had low binding energy toward the active pocket and thus they may act as a good Leucyl-tRNA synthase inhibitor.

Structure-Based Design and Evaluation of Naphthalene Diimide G-Quadruplex Ligands As Telomere Targeting Agents in Pancreatic Cancer Cells

Tetra-substituted naphthalene diimide (ND) derivatives with positively charged termini are potent stabilizers of human telomeric and gene promoter DNA quadruplexes and inhibit the growth of human cancer cells in vitro and in vivo. The present study reports the enhancement of the pharmacological properties of earlier ND compounds using structure-based design. Crystal structures of three complexes with human telomeric intramolecular quadruplexes demonstrate that two of the four strongly basic N-methyl-piperazine groups can be replaced by less basic morpholine groups with no loss of intermolecular interactions in the grooves of the quadruplex. The new compounds retain high affinity to human telomeric quadruplex DNA but are 10-fold more potent against the MIA PaCa-2 pancreatic cancer cell line, with IC50 values of ~10 nM. The lead compound induces cellular senescence but does not inhibit telomerase activity at the nanomolar dosage levels required for inhibition of cellular proliferation. Gene array qPCR analysis of MIA PaCa-2 cells treated with the lead compound revealed significant dose-dependent modulation of a distinct subset of genes, including strong induction of DNA damage responsive genes CDKN1A, DDIT3, GADD45A/G, and PPM1D, and repression of genes involved in telomere maintenance, including hPOT1 and PARP1.

Ammosamide D, an Oxidatively Ring Opened Ammosamide Analog from a Marine-Derived Streptomyces variabilis

Ammosamide D (1), an oxidized analog of the ammosamide family, was isolated from a marine-derived Streptomyces variabilis. Pyrroloquinoline containing alkaloids are a growing class of natural products, with 1 being the first example of an oxidized analog resulting in a 5,6-dioxo-5,6-dihydroquinoline ring system. Attempts at chemical conversion of ammosamide B to ammosamide D revealed that a strong chemical oxidant is required. Ammosamide D has modest cytotoxicity to the MIA PaCa-2 pancreatic cancer cell line.

Abstract 1632: Novel naproxen, resveratrol and sulforaphane (NRS) combinations demonstrate synergistic decrease in cell viability of human colon and pancreatic cancer cell lines

Abstract Gastrointestinal cancers, in particular colon and pancreatic cancer, account for almost 100,000 deaths each year in the United States, ranking third and fourth respectively, in the most common cause of cancer related deaths. Our lab has been focused on developing strategies for chemoprevention rather than treatment after diagnosis. For pancreatic cancer, the prognosis is usually poor with high mortality rates after diagnosis. Thus, the objective of this work was to study the effects of chemopreventive combination regimens of a non-steroidal anti-inflammatory drug (NSAID) naproxen (N), in combination with resveratrol (R, an antioxidant) and sulforaphane (S, a broccoli extract) on human colon (HT-29 and HCT-116) and pancreatic (MIA PaCa-2 and Panc-1) cancer cell lines. MTS cell proliferation assay was conducted on all cell lines. For the MTS assay, upon 75 % confluence, 100µL of 2.5X103 cells each of HT-29, HCT116 and MIA PaCa-2 and 4X10 3 cells Panc-1 cells were transferred into each well of 96-well plates. The NRS chemopreventive agents alone, or in combination, were added to the cells and incubated for 72 h. The plates were then incubated for 1-4 h at 37°C in a humidified, 5% CO2 atmosphere. Absorbance was recorded at 490 nm using an ELISA plate reader. For HT-29 and HCT 116 colon cancer cell lines, the combinations of naproxen (500µM/L) with resveratrol (50µM/L) and sulforaphane (5µM/L) showed reduction in cell viability of 56.74% and 52.9%, respectively. The IC50 values for NRS were 1.46 mM/L,104.54µM/L and 17.81µM/L respectively on HT-29 cell line. Similarly, for MIA PaCa-2 and Panc-1 pancreatic cancer cell lines, combinations of naproxen (500µM/L) with resveratrol (6µM/L) and sulforaphane (5µM/L) showed reduction in cell viability of 66.67% and 58.8% respectively. The IC50 values for NRS were 778µM/L, 74.8µM/L and 11.82µM/L respectively, on MIA Paca-2 cell line. When used individually, none of the chemopreventive agents at the above concentrations demonstrated any decrease in cell viability, however when combined together, a synergistic effect was observed. Our results demonstrate that NRS drug combinations at low concentrations exhibit significant decrease in cell proliferation in both human colon and pancreatic cancer cell lines. This data provides compelling evidence of the potential of these combination regimens for the chemoprevention of colon and pancreatic cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1632. doi:1538-7445.AM2012-1632

Generation of a Focused Poly(amino ether) Library: Polymer-mediated Transgene Delivery and Gold-Nanorod based Theranostic Systems

A focused library of twenty-one cationic poly(amino ethers) was synthesized following ring-opening polymerization of two diglycidyl ethers by different oligoamines. The polymers were screened in parallel for plasmid DNA (pDNA) delivery, and transgene expression efficacies of individual polymers were compared to those of 25 kDa polyethylenimine (PEI), a current standard for polymer-mediated transgene delivery. Seven lead polymers that demonstrated higher transgene expression than PEI in pancreatic and prostate cancer cells lines were identified from the screen. All seven lead polymers showed highest transgene expression at a polymer:pDNA weight ratio of 5:1 in the MIA PaCa-2 pancreatic cancer cell line. Among the conditions studied, transgene expression efficacy correlated with minimal polymer cytotoxicity but not polyplex sizes. In addition, this study indicated that methylene spacing between amine centers in the monomers, amine content, and molecular weight of the polymers are all significant factors and should be considered when designing polymers for transgene delivery. A lead effective polymer was employed for coating gold nanorods, leading to theranostic nanoassemblies that possess combined transgene delivery and optical imaging capabilities, leading to potential theranostic systems.

Insig2 is overexpressed in pancreatic cancer and its expression is induced by hypoxia

A hypoxic microenvironment is a characteristic feature of pancreatic cancer, and induces the expressions of various genes involved in malignant behaviors. Insulin-induced gene 2 (Insig2) has recently been shown to be correlated with cellular invasion in colon cancer. However, there have been no reports regarding its expression in pancreatic cancer. In this study, we evaluated Insig2 mRNA expression and the biological function of Insig2 in pancreatic cancer. We measured Insig2 mRNA expression in cultured pancreatic cancer cell lines and invasive ductal carcinoma (IDC) cells, normal pancreatic epithelial cells, and pancreatic intraepithelial neoplasia cells obtained by laser-capture microdissection. We also investigated the effects of Insig2-targeting siRNAs on the cell proliferation and cell invasion of pancreatic cancer cell lines. All pancreatic cancer cell lines expressed Insig2 mRNA. The PANC-1 and MIA PaCa-2 pancreatic cancer cell lines showed >2-fold higher Insig2 mRNA expression levels under hypoxic conditions (1% O2) than under normoxic conditions (21% O2 ). Cell proliferation was significantly decreased in SUIT-2 cells and cell invasion was significantly decreased in SUIT-2, Capan-2, and CFPAC-1 cells after transfection of the Insig2-targeting siRNAs. In analyses of microdissected cells, cells from IDC tissues expressed significantly higher levels of Insig2 mRNA than normal pancreatic cells (P < 0.001) and pancreatic intraepithelial neoplasia cells (P = 0.082). In analyses of IDC cells, the levels of Insig2 mRNA expression were significantly higher in late-stage patients than in early-stage patients. The present data suggest that Insig2 is associated with the malignant potential of pancreatic cancer under hypoxic conditions.

Abstract 4591: Comparison of the inhibitory effects of unmodified and modified combinations of chemopreventive agents on MIA PaCa-2 and Panc-1 human pancreatic cancer cell lines

Abstract Pancreatic cancer is the fourth leading cause of death in the United States with approximately 40,000 estimated deaths in 2010. The objective of our study was to compare the effectiveness of chemopreventive combination regimens of aspirin, curcumin and sulforaphane (ACS) administered in unmodified (free drug) and in modified forms, encapsulated within solid lipid nanoparticles (SLNs), on the MIA PaCa-2 and Panc-1 human pancreatic cancer cell lines. MTS cell proliferation and apoptosis assay studies were conducted on cultured cells. For the MTS assay, upon 75 % confluence, 2.5 × 103 cells for MIA PaCa-2 and 4 × 103 cells for Panc-1 were transferred into each well of 96-well plates. The ACS chemopreventive agents alone or in combination were added to the cells and incubated for 72 h. Absorbance was recorded at 490 nm using an ELISA plate reader. For the apoptosis assay, 3 × 105 cells were cultured in 6-well plates for both Panc-1 and MIA PaCa-2 cell-lines. ACS, individual or combinations, were added and the plates were incubated for 72 h. Cells were analyzed using flow cytometry, measuring the fluorescence emission at 530 nm (FL1) and &amp;gt;575 nm (FL3). IC50 values obtained for the respective unmodified and modified forms of aspirin were (2.05mM/L; 66.08µM/L), curcumin (16.05µM/L; 4.93µM/L) and free sulforaphane at 11.82 µM/L for MIA PaCa-2 cells. Similarly, for Panc-1 cells, the IC50 values for unmodified and modified aspirin were (2.42mM/L; 90.23µM/L), curcumin (24.01 µM/L; 7.5µM/L) respectively and free sulforaphane at 17.81µM/L. For MIA PaCa-2 cell line, unmodified combinations of aspirin (1mM/L) with curcumin (10µM/L) and sulforaphane (5µM/L) showed significant reduction in cell viability of &amp;gt;60% using MTS assay. In comparison, aspirin SLN (25µM/L), curcumin SLN (2.5µM/L) and free sulforaphane (5µM/L) mixtures showed cell viability of &amp;gt;55%. Flow cytometry analysis demonstrated apoptosis of 63% (unmodified) and 50% (modified) for the combinations, at the same concentration ranges as above. For the Panc-1 cell line, treatment with similar concentrations of unmodified and modified SLN combinations showed a &amp;gt;75% and &amp;gt;60% decrease in cell viability (MTS assay) and 63% and 54% induction of apoptosis cells, respectively. Our results demonstrated that the drugs when encapsulated in SLNs at lower concentrations exhibited decreasing cell proliferation and increased induction of apoptosis within the pancreatic cancer cell lines. This data provides compelling evidence of the potential of the SLN carrier system in designing in-vivo studies for the pancreatic cancer chemoprevention. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4591. doi:10.1158/1538-7445.AM2011-4591

Abstract 1724: Inhibition of the PI3K and mTOR pathways reverses gemcitabine resistance in pancreatic cancer

Abstract BACKGROUND: Despite chemotherapy, survival for most patients with pancreatic cancer is less than one year. These dismal statistics reflect the lack of effective therapy. Understanding the molecular pathways that drive cancer growth may help target our therapy. Over 90% of pancreatic cancers are K-ras mutant which activates the PI3K/AKT pathway and signals downstream to mTOR leading to cell growth, proliferation and survival. We explored the combination of gemcitabine and BEZ235, a novel dual PI3K/mTOR inhibitor, in pancreatic cancer cell lines. METHODS: Cytotoxicity assays were performed utilizing the CellTiter-96-Aqueous-One-Solution-Cell-Proliferation-Assay-(MTS) from Promega in K-ras mutant MIA PaCa-2 pancreatic cancer cell lines. We generated gemcitabine resistant cell lines by serial passage of cells with increasing concentrations of drug. We utilized the CalcuSyn program by Biosoft to quantify synergism or antagonism with drug combinations. We also collected cells 6 hours after drug treatment for analysis of phosphorylated proteins. RESULTS: MIA PaCa-2 wild-type and gemcitabine resistant cells were treated with 100, 50 and 25 nM of either gemcitabine, BEZ235 or the combination of both. At the 100 nM dose, cell viability of the wild-type cells was 66%, 55% and 39% respectively. In the gemcitabine resistant cells, cell viability was 84%, 63% and 44%. The combination index was 0.51 in the wild-type cells and 0.46 in the gemcitabine resistant cells indicating synergy in both cell lines. In both cell lines, p-S6K and p-AKT levels increased with gemcitabine treatment which was abrogated by treatment with BEZ-235. Interestingly, in the gemcitabine resistant cells, there appeared to be significantly increased levels of p-MEK1 compared to control. CONCLUSION: Because pancreatic cancer remains resistant to current therapies despite recent advances in the development of molecular targeted therapies, there is an urgency to understand these pathways. We showed that the combination of gemcitabine and BEZ235 is synergistic in both cell lines but cell viability still remains high at 39% and 44% respectively. Combination with a MEK inhibitor may help to increase cell apoptosis and studies are on-going. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1724. doi:10.1158/1538-7445.AM2011-1724

Abstract 2456: External uPA overexpresses and interacts with Lhx-2 and induces a pancreatic cancer stem cell phenotype

Abstract Although the body of knowledge surrounding the molecular profile of pancreatic cancer has substantially increased, survival rates have not changed for over four decades. Previous studies have demonstrated that urokinase plasminogen activator (uPA) is frequently present in a higher concentration in the serum of pancreatic cancer patients. uPA is involved in extracellular matrix (ECM) degradation and has been correlated with the malignant transformation of cancer cells. Additionally, recent reports have also shown the translocation of uPA to the nucleus without binding to uPAR. However, its role in the nucleus is still unclear. Existing evidence suggest that a hypoxic environment forces cancer cells to acquire stem cell characteristics, causing recurrence after chemotherapy and radiation. In the present study, we have attempted to correlate the roles of uPA and hypoxia in cancer stem cell transformation. Initially, to determine the interaction of uPA with Lhx-2, we conducted immunoprecipitation and immunolocalization studies in MIA PaCa-2 and PANC-1 pancreatic cancer cell lines. Further, to determine the role of exogenous uPA on Lhx-2 expression in an uPA-null background, cells were downregulated for uPA and followed by supplementation with purified uPA under normoxic as well as hypoxic conditions. To further resolve whether Lhx-2 is involved in the activation of CD133 and STRO-1 expression in pancreatic cells, uPA and/or Lhx-2 were knocked down under normoxic or hypoxic conditions and the expression levels of CD133 and STRO-1 were determined. In addition, cell lysates were screened for stem cell markers using stem cell-specific antibody arrays. To determine the role of uPA in tumorigenicity after hypoxia, MIA PaCa-2 or PANC-1 hypoxic cells were subcutaneously implanted in nude mice followed by injection of siRNA for uPA or Lhx-2 and 100 nM of uPA at the tumor site, and tumor growth was determined. From the immunoprecipitation and immunolocalization studies, we observed that uPA interacts with Lhx-2 both in the cytoplasm and the nucleus of MIA PaCa-2 and PANC-1 pancreatic cancer cells. Further, we observed that the addition of external uPA caused an increase in the expression of Lhx-2. The addition of uPA under hypoxic conditions resulted in increased expression of CD133 and STRO-1 whereas suppression of Lhx-2 retarded the overexpression of CD133 and STRO-1. Antibody array analysis indicated that hypoxic cells had increased expression of stem cell markers when supplemented with uPA, which was abolished by suppression of Lhx-2. From the animal studies, we observed that hypoxic MIA PaCa-2 or PANC-1 cells supplemented with external uPA were able to form subcutaneous tumors within 30 days of implantation. Taken together, our results demonstrate that in a hypoxic environment, uPA activates the expression of stem cell markers mediated by the expression of Lhx-2. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2456. doi:10.1158/1538-7445.AM2011-2456

Expression of organic anion-transporting polypeptides 1B3, 1B1, and 1A2 in human pancreatic cancer reveals a new class of potential therapeutic targets

Background:Organic anion-transporting polypeptides (OATPs) are influx transporters that mediate intracellular uptake of selective endogenous and xenobiotic compounds. Identification of new molecular targets and discovery of novel targeted therapies is top priority for pancreatic cancer, which lacks any effective therapy.Materials and methods:We studied expression of OATP 1A2, 1B1, and 1B3 in pancreatic cancer tissue and in cell lines. Formalin-fixed paraffin-embedded biopsy material of 12 human pancreatic cancers was immunohistochemically assessed for protein expression of the three studied influx transporters. Immunohistochemistry was evaluated by experienced pathologists and quantified by use of an automated image analysis system. BxPC-3 and MIA PaCa-2 pancreatic cancer cell lines were used to quantify transcripts of OATP 1B1 and 1B3.Results:OATP 1A2, 1B1, and 1B3 proteins were found ubiquitously expressed in all studied cases. Quantification performed by HistoQuest system revealed that mean intensity was 53 for 1A2, 45 for 1B1, and 167 for OATP 1B1/1B3 on a range scale 0–250 units. At mRNA level, 1B1 and 1B3 were overexpressed in both studied cancer cell lines but not in normal pancreatic tissue.Conclusion:OATPs 1A2, 1B1, and 1B3 are highly expressed in pancreatic adenocarcinoma. We suggest that expression of these transporters in pancreatic cancer justify research efforts towards discovery of novel therapeutics targeting OATPs.

Study of Apoptosis Induction and Deoxycytidine Kinase/Cytidine Deaminase Modulation in the Synergistic Interaction of a Novel Ceramide Analog and Gemcitabine in Pancreatic Cancer Cells

This study investigated the interaction between the novel ceramide analog AL6 and gemcitabine in MIA PaCa-2 and PANC-1 pancreatic cancer cell lines, harboring different polymorphic variants of the gemcitabine catabolism enzyme cytidine deaminase (CDA). AL6 dose-dependently inhibited cell growth, induced apoptosis and synergistically enhanced the cytotoxic activity of gemcitabine. Moreover, it triggered apoptosis, which was significantly enhanced by the combination, and increased the ratio between gene expression of the activating enzyme deoxycytidine kinase (dCK) and CDA, potentially favoring gemcitabine activity. In conclusion, AL6 displays synergistic cytotoxic activity, enhances apoptosis, and favorably modulates enzymes involved in gemcitabine metabolism, supporting future investigation of this combination in pancreatic cancer.