MIA PaCa-2 Pancreatic Carcinoma Cells Research Articles

MEK inhibitors and DA-Raf, a dominant-negative antagonist of the Ras-ERK pathway, prevent the migration and invasion of KRAS-mutant cancer cells.

The Ras-induced ERK pathway (Raf-MEK-ERK signaling cascade) regulates a variety of cellular responses including cell proliferation, survival, and migration. Activating mutations in RAS genes, particularly in the KRAS gene, constitutively activate the ERK pathway, resulting in tumorigenesis, cancer cell invasion, and metastasis. DA-Raf1 (DA-Raf) is a splicing isoform of A-Raf and contains the Ras-binding domain but lacks the kinase domain. Consequently, DA-Raf antagonizes the Ras-ERK pathway in a dominant-negative manner and can serve as a tumor suppressor that targets mutant Ras protein-induced tumorigenesis. We show here that MEK inhibitors and DA-Raf interfere with the in vitro collective cell migration and invasion of human KRAS-mutant carcinoma cell lines, the lung adenocarcinoma A549, colorectal carcinoma HCT116, and pancreatic carcinoma MIA PaCa-2 cells. DA-Raf expression was silenced in these cancer cell lines. All these cell lines had high collective migration abilities and invasion properties in Matrigel, compared with nontumor cells. Their migration and invasion abilities were impaired by suppressing the ERK pathway with the MEK inhibitors U0126 and trametinib, an approved anticancer drug. Expression of DA-Raf in MIA PaCa-2 cells reduced the ERK activity and hindered the migration and invasion abilities. Therefore, DA-Raf may function as an invasion suppressor protein in the KRAS-mutant cancer cells by blocking the Ras-ERK pathway when DA-Raf expression is induced in invasive cancer cells.

Abstract 1605: Oncolytic hsv-1(vc2) gm-csf regulates the proinflammatory profile suggestive of an immunomodulatory effect in PDAC cells

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease that is projected to be the second leading cause of cancer-associated deaths by 2030. Owing to its intrinsic immune evasive tumor microenvironment (TME), PDAC is regarded as an immunologically “cold” tumor with a significant therapeutic challenge. Although 5-fluorouracil or gemcitabine-based chemotherapy is considered as standard of care, harnessing immunological pathways may potentially convert PDAC to a “hot” tumor, thereby providing survival advantage to patients. Lately, the use of oncolytic virus has proven to be an alternative strategy to activate the innate immune response within the TME coupled with its cytotoxic effect against the cancer cells. The FDA approval of T-VEC for the treatment of stage IIIB/IV melanoma validates the preceding argument. In this study, we have investigated the effect of herpes simplex virus type-1 (HSV-1) (VC2) overexpressing granulocyte-macrophage colony-stimulating factor (GMCSF), HSV-1VC2GM-CSF in the murine KRAS, p53, and Cre (KPC), and human MIA PaCa-2 pancreatic carcinoma cells. Following a 24h infection of the KPC and MIA PaCa-2 cells with the HSV-1VC2GM-CSF, the observed cytopathic effects (CPE) included cell rounding, detachment, and aggregation as compared to the wild-type HSV-1VC2 treated or the uninfected control cells. The CPE effect of HSV-1VC2GM-CSF was proven to be a more direct and dynamic response against these cells. In the next steps, the viral titers were determined to be 9.6E7 pfu/ml, 1.26E7 pfu/ml for HSV-1VC2 and VC2GM-CSF respectively. The infection of VC2GM-CSF 0.1, 1.0 and 10 MOI in KPC cells resulted in a significant increase in the expression of proinflammatory markers including interleukin 10 (IL-10), cyclooxygenase -2 (COX-2) and iNOS at the gene level in contrast to the uninfected controls. This was coupled with an increase in the expression of Fas ligand (FasL) in the treated cells. Intriguingly, the treated cells showed a significant upregulation of programmed death ligand (PD-L1). Interestingly, in a 3D-coculture of KPC and RAW264.7 cells the expression of PD-L1 was significantly upregulated. Based on the evidence presented here, it is speculated that VC2GM-CSF-induced proinflammatory profile in KPC and Mia PaCa-2 cells converts to an immunomodulatory one characterized by the regulation of FasL and PD-L1. The effect of VC2GM-CSF in a PDAC organoid model to understand the interplay between the tumor and the stromal cells in response to the virus is currently underway. Citation Format: Naveen Chintala Ramulu, Shilpa Thota, Brent Stanfield, Konstantin Kousoulas, Joseph Francis. Oncolytic hsv-1(vc2) gm-csf regulates the proinflammatory profile suggestive of an immunomodulatory effect in PDAC cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1605.

PW06 suppresses cancer cell metastasis in human pancreatic carcinoma MIA PaCa-2 cells via the inhibitions of p-Akt/mTOR/NF-κB and MMP2/MMP9 signaling pathways in vitro.

PW06 [(E)-3-(9-ethyl-9H-carbazol-3-yl)-1-(2,5-dimethoxyphenyl) prop-2-en-1-one], a kind of the carbazole derivative containing chalcone moiety, inducedcell apoptosisin human pancreatic carcinoma in vitro. There is no investigation to show that PW06 inhibits cancer cell metastasis in human pancreatic carcinoma in vitro. Herein, PW06 (0.1-0.8 μM) significantly exists in the antimetastatic activities of human pancreatic carcinoma MIA PaCa-2 cells in vitro. Wound healing assay shows PW06 at 0.2 μM suppressed cell mobility by 7.45 and 16.55% at 6 and 24 hours of treatments. PW06 at 0.1 and 0.2 μM reduced cell mobility by 14.72 and 21.8% for 48 hours of treatment. Transwell chamber assay indicated PW06 (0.1-0.2 μM) suppressed the cell migration (decreased 26.67-35.42%) and invasion (decreased 48.51-68.66%). Atomic force microscopy assay shows PW06 (0.2 μM) significantly changed the shape of cell morphology. The gelatin zymography assay indicates PW06 decreased MMP2's and MMP9's activitiesat 48 hours of treatment. Western blotting assay further confirms PW06 reduced levels of MMP2 and MMP9 and increased protein expressions of EGFR, SOS1, and Ras. PW06 also increased the p-JNK, p-ERK, and p-p38. PW06 increased the expression of PI3K, PTEN, Akt, GSK3α/β, and E-cadherin. Nevertheless, results also show PW06 decreased p-Akt, mTOR, NF-κB, p-GSK3β, β-catenin, Snail, N-cadherin, and vimentin in MIA PaCa-2 cells. The confocal laser microscopy examination shows PW06 increased E-cadherin but decreased vimentin in MIA PaCa-2 cells. Together, our findings strongly suggest that PW06 inhibited the p-Akt/mTOR/NF-κB/MMPs pathways, increased E-cadherin, and decreased N-cadherin/vimentin, suppressing the migration and invasion in MIA PaCa-2 cells in vitro.

PW06 Triggered Fas-FADD to Induce Apoptotic Cell Death In Human Pancreatic Carcinoma MIA PaCa-2 Cells through the Activation of the Caspase-Mediated Pathway.

Pancreatic cancer has higher incidence and mortality rates worldwide. PW06 [(E)-3-(9-ethyl-9H-carbazol-3-yl)-1-(2,5-dimethoxyphenyl) prop-2-en-1-one] is a carbazole derivative containing chalcone moiety which was designed for inhibiting tumorigenesis in human pancreatic cancer. This study is aimed at investigating PW06-induced anticancer effects in human pancreatic cancer MIA PaCa-2 cells in vitro. The results showed PW06 potent antiproliferative/cytotoxic activities and induced cell morphological changes in a human pancreatic cancer cell line (MIA PaCa-2), and these effects are concentration-dependent (IC50 is 0.43 μM). Annexin V and DAPI staining assays indicated that PW06 induced apoptotic cell death and DNA condensation. Western blotting indicated that PW06 increased the proapoptotic proteins such as Bak and Bad but decreased the antiapoptotic protein such as Bcl-2 and Bcl-xL. Moreover, PW06 increased the active form of caspase-8, caspase-9, and caspase-3, PARP, releasing cytochrome c, AIF, and Endo G from mitochondria in MIA PaCa-2 cells. Confocal laser microscopy assay also confirmed that PW06 increased Bak and decreased Bcl-xL. Also, the cells were pretreated with inhibitors of caspase-3, caspase-8, and caspase-9 and then were treated with PW06, resulting in increased viable cell number compared to PW06 treated only. Furthermore, PW06 showed a potent binding ability with hydrophobic interactions in the core site of the Fas-Fas death domains (FADD). In conclusion, PW06 can potent binding ability to the Fas-FADD which led to antiproliferative, cytotoxic activities, and apoptosis induction accompanied by the caspase-dependent and mitochondria-dependent pathways in human pancreatic cancer MIA PaCa-2 cells.

MicroRNA-23a acts as an oncogene in pancreatic carcinoma by targeting TFPI-2.

Pancreatic carcinoma (PC) is a rapidly progressive, fatal malignant tumor with the poorest prognosis among all major carcinoma types. MicroRNAs (miRNAs/miRs) have been indicated to be key post-transcriptional regulatory factors, which are involved in cancer development. The present study was designed to investigate the effect of miR-23a on PC cell proliferation, metastasis and apoptosis. The expression of miR-23a was detected in a normal pancreatic ductal epithelial cell line and three PC cell lines, and miR-23a inhibitor or mimics were transfected into the Panc-1 and MiaPaCa2 PC cells. The association between miR-23a and tissue factor pathway inhibitor (TFPI)-2 was examined using a luciferase reporter assay. MTT and flow cytometry assays were used to assess cell viability and apoptosis, respectively. Furthermore, wound-healing, Transwell and Matrigel assays were used to evaluate cell migration and invasion abilities, and the protein expression level of TFPI-2 was determined using western blot analysis. The results of the present study revealed that miR-23a was upregulated in PC cells. Furthermore, TFPI-2 was identified as a downstream target of miR-23a, and TFPI-2 expression was found to be increased following miR-23a knockdown. In addition, functional assays revealed that downregulation of miR-23a decreased PC cell proliferation, migration and invasiveness and promoted cell apoptosis, while miR-23a overexpression exerted the opposite effects. Furthermore, TFPI-2 knockdown rescued the biological effects on PC cells, which were induced by miR-23a knockdown. The results of the present study indicated that miR-23a negatively modulated TFPI-2 expression in vitro and enhanced the malignant phenotypes of PC cells. Therefore, miR-23a may be a potential marker and/or target for the diagnosis and treatment of PC.

Cascade therapy with doxorubicin and survivin-targeted tailored nanoparticles: An effective alternative for sensitization of cancer cells to chemotherapy

Chemotherapy frequently involves combination treatment protocols to maximize tumor cell killing. Unfortunately these intensive chemotherapeutic regimes, often show disappointing results due to the development of drug resistance and higher nonspecific toxicity on normal tissues. In cancer treatment, it is critically important to minimize toxicity while preserving efficacy. We have previously addressed this issue and proposed a nanoparticle-based combination therapy involving both a molecularly targeted therapy and chemotherapeutic agent for neutralizing antiapoptotic survivin (BIRC5) to potentiate the efficacy of doxorubicin (DOX). Although the particles exhibited strong anticancer effect on the lung carcinoma A549 and the cervical carcinoma HeLa cells, there were lower-level therapeutic outcomes on the colon carcinoma HCT-116, the leukemia Jurkat and the pancreatic carcinoma MIA PaCa-2 cells. Since targeted therapies are one of the key approaches for overcoming drug resistance, tailoring the treatment of cancer cells with distinct characteristics is necessary to improve the therapeutic outcome of cancer therapy and to minimize potential pharmacokinetic interactions of drugs. In the light of this issue, this study examined whether a cascade therapy with low-dose DOX and survivin-targeted tailored nanoparticles is more effective at sensitizing HCT-116, Jurkat and MIA PaCa-2 cancer cells to DOX-chemotherapy than simultaneous combination therapy. The results demonstrated that the sequential therapy with the protocol comprising addition of the nanoparticles after incubation of cells with DOX clearly advanced the therapeutic outcome of related cancer cells, whereas the reverse protocol resulted in a reduction or delay in apoptosis, emphasizing the critical importance of formulating synergistic drug combinations in cancer therapy.

Apoferritin encapsulation of cysteine protease inhibitors for cathepsin L inhibition in cancer cells.

Cysteine proteases play a key role in tumorigenesis causing protein degradation and promoting invasive tumour growth. Cathepsin L is overexpressed in cancer cells and could provide a specific target for delivery of anticancer agents. We encapsulated novel dipeptidyl nitrile based cysteine protease inhibitors (Neq0551, Neq0554 and Neq0568) into biocompatible apoferritin (AFt) protein nanocages to achieve specific delivery to tumours and pH-induced drug release. AFt-encapsulated Neq0554 demonstrated ∼3-fold enhanced in vitro activity (GI50 = 79 μM) compared to naked agent against MiaPaCa-2 pancreatic carcinoma cells. Selectivity for cancer cells was confirmed by comparing their activity to non-tumourigenic human fibroblasts (GI50 > 200 μM). Transferrin receptor (TfR-1) expression, detected only in lysates prepared from carcinoma cells, may contribute to the cancer-selectivity. The G1 cell cycle arrest caused by AFt-Neq0554 resulting in cytostasis was corroborated by clonogenic assays. Superior and more persistent inhibition of cathepsin L up to 80% was achieved with AFt-encapsulated agent in HCT-116 cells following 6 h exposure to 50 μM agent. The selective anticancer activity of AFt-encapsulated cysteine protease inhibitor Neq0554 reported here warrants further preclinical in vivo evaluation.

Cell-specific pattern of berberine pleiotropic effects on different human cell lines

The natural alkaloid berberine has several pharmacological properties and recently received attention as a potential anticancer agent. In this work, we investigated the molecular mechanisms underlying the anti-tumor effect of berberine on glioblastoma U343 and pancreatic carcinoma MIA PaCa-2 cells. Human dermal fibroblasts (HDF) were used as non-cancer cells. We show that berberine differentially affects cell viability, displaying a higher cytotoxicity on the two cancer cell lines than on HDF. Berberine also affects cell cycle progression, senescence, caspase-3 activity, autophagy and migration in a cell-specific manner. In particular, in HDF it induces cell cycle arrest in G2 and senescence, but not autophagy; in the U343 cells, berberine leads to cell cycle arrest in G2 and induces both senescence and autophagy; in MIA PaCa-2 cells, the alkaloid induces arrest in G1, senescence, autophagy, it increases caspase-3 activity and impairs migration/invasion. As demonstrated by decreased citrate synthase activity, the three cell lines show mitochondrial dysfunction following berberine exposure. Finally, we observed that berberine modulates the expression profile of genes involved in different pathways of tumorigenesis in a cell line-specific manner. These findings have valuable implications for understanding the complex functional interactions between berberine and specific cell types.

In Vivo Observation of Endothelial Cell-Assisted Vascularization in Pancreatic Cancer Xenograft Engineering.

In this study, for better understanding of patient-derived xenograft (PDX) generation, angiogenic characteristics during PDX cancerous tissue generation was investigated with different initial cell seeding conditions in the hydrogel. We monitored the angiogenic changes during the formation of in vivo cancer cell line xenografts induced by endothelial cells. Our in vivo cancer tissue formation system was designed with the assistance of tissue engineering technology to mimic patient-derived xenograft formation. Endothelial cells and MIA PaCa-2 pancreatic carcinoma cells were encapsulated in fibrin gel at different mixing configurations and subcutaneously implanted into nude mice. To investigate the effect of the initial cancerous cell distribution in the fibrin gel, MIA PaCa-2 cells were encapsulated as a homogeneous cell distribution or as a cell aggregate, with endothelial cells homogeneously distributed in the fibrin gel. Histological observation of the explanted tissues after different implantation periods revealed three different stages: isolated vascular tubes, leaky blood vessels, and mature cancerous tissue formation. The in vivo engineered cancerous tissues had leaky blood vessels with low expression of the vascular tight junction marker CD31. Under our experimental conditions, complex cancer-like tissue formation was most successful when tumorous cells and endothelial cells were homogeneously mixed in the fibrin gel. The present study implies that tumorous xenograft tissue formation can be achieved with a low number of initial cells and that effective vascularization conditions can be attained with a limited volume of patient-derived cancer tissue. Endothelial cell-assisted vascularization can be a potent choice for the effective development of vascularized cancerous tissues for studying patient-derived xenografts, cancer angiogenesis, cancer metastasis, and anticancer drugs.

A new HDAC inhibitor cinnamoylphenazine shows antitumor activity in association with intensive macropinocytosis.

Previous studies have shown that intensive macropinocytosis occurs in cancer cells and neutral red (NR) is noted for its capability to enter into the cell massively through a process mimetic to macropinocytosis. In addition, trans-cinnamic acid (tCA) has been found to be an inhibitor of histone deacetylase (HDAC). In the present study, cinnamoylphenazine (CA-PZ) that consists of NR and tCA moieties was synthesized and evaluated. As shown, CA-PZ massively entered into colon carcinoma HT-29 cells and pancreatic carcinoma MIA PaCa-2 cells and this entry was blocked by 5-(N-ethyl-N-isopropyl) amiloride (EIPA, an inhibitor of macropinocytosis), indicating a macropinocytosis-mediated uptake. Furthermore, CA-PZ markedly increased the protein expression levels of acetyl-H3, acetyl-H4 and p21 in HT-29 cells and MIA PaCa-2 cells. CA-PZ significantly inhibited the growth of colon carcinoma HT-29 and pancreatic carcinoma MIA PaCa-2 xenografts. By in vivo imaging, CA-PZ displayed prominent accumulation in the tumor xenografts. The study indicates that the newly synthesized CA-PZ acts as an HDAC inhibitor in association with intensive macropinocytosis-mediated intracellular delivery in cancer cells. The use of neutral red for preparation of chimeric molecules with the attribute of macropinocytosis-mediated intracellular delivery might open an alternative way for development of HDAC inhibitors.

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

The 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). The 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. Low-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. Our 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.

Synthesis and characterization of multifunctional hybrid-polymeric nanoparticles for drug delivery and multimodal imaging of cancer.

In this study, multifunctional hybrid-polymeric nanoparticles were prepared for the treatment of cultured multicellular tumor spheroids (MCTS) of the PANC-1 and MIA PaCa-2 pancreatic carcinoma cell lines. To synthesize the hybrid-polymeric nanoparticles, the poly lactic-co-glycolic acid core of the particles was loaded with Rhodamine 6G dye and the chemotherapeutic agent, Paclitaxel, was incorporated into the outer phospholipid layer. The surface of the nanoparticles was coated with gadolinium chelates for magnetic resonance imaging applications. This engineered nanoparticle formulation was found to be suitable for use in guided imaging therapy. Specifically, we investigated the size-dependent therapeutic response and the uptake of nanoparticles that were 65 nm, 85 nm, and 110 nm in size in the MCTS of the two pancreatic cancer cell lines used. After 24 hours of treatment, the MCTS of both PANC-1 and MIA PaCa-2 cell lines showed an average increase in the uptake of 18.4% for both 65 nm and 85 nm nanoparticles and 24.8% for 110 nm nanoparticles. Furthermore, the studies on therapeutic effects showed that particle size had a slight influence on the overall effectiveness of the formulation. In the MCTS of the MIA PaCa-2 cell line, 65 nm nanoparticles were found to produce the greatest therapeutic effect, whereas 12.8% of cells were apoptotic of which 11.4% of cells were apoptotic for 85 nm nanoparticles and 9.79% for 110 nm nanoparticles. Finally, the study conducted in vivo revealed the importance of nanoparticle size selection for the effective delivery of drug formulations to the tumors. In agreement with our in vitro results, excellent uptake and retention were found in the tumors of MIA PaCa-2 tumor-bearing mice treated with 110 nm nanoparticles.

Apoptotic activity and antitumor efficacy of PEGylated TNF-related apoptosis-inducing ligand (TRAIL) in a Mia Paca-2 cell-xenografted mouse model

The purpose of this study was to demonstrate the apoptotic activity and antitumor effect of PEGylated tumor necrosis factor-related apoptosis-inducing ligand (PEG-TRAIL) in pancreatic carcinoma Mia Paca-2 cells and in Mia Paca-2 cell-xenografted mice. PEG-TRAIL was prepared using mPEG-aldehyde (Mw 5 kDa). The apoptosis induced by PEG-TRAIL in Mia Paca-2 cells and in the tumors of Mia Paca-2 cell-xenografted mice was quantified by FACS analysis and using a TUNEL assay. Mia Paca-2 cell-xenografted BALB/c nu/nu mice were administered intratumoral injections of PEG-TRAIL (50 μg/mouse/injection) every 3 days from day 0 (~4 weeks after xenografting) to day 15. Tumor volumes were measured every 3 days from day 0 to day 27. PEG-TRAIL displayed obvious apoptotic activity in Mia Paca-2 cells; the FACS signal was shifted to the apoptotic area and the cells exhibited green fluorescence indicating apoptosis in the TUNEL assay. Furthermore, PEG-TRAIL was found to suppress tumors in Mia Paca-2 cell-xenografted mice (tumor volumes: 183.9±134.1 for PEG-TRAIL vs. 1827.3±264.5 mm(3) for saline control). In addition, in vivo TUNEL assays of tumor tissues showed that the antitumor effect of PEG-TRAIL was due apoptosis. Our findings provide clear in vivo evidence of the antitumor potential of PEG-TRAIL in a Mia Paca-2 cell-xenografted mouse model based of pancreatic cancer.

Effect of ABTL0812, a safe dual inhibitor of mTORC1/C2 and dihydrofolate reductase, on gemcitabine and docetaxel cytotoxicity in pancreatic and lung cancer cells.

e13526 Background: We have previously described that ABTL0812 has oral anticancer properties. The action is exerted through a mechanism of action involving the inhibition of mTORC1 and mTORC2 (mammalian target of rapamycin) pathways and dihydrofolate reductase (DHFR) expression. Administration of ABTL0812 reduced tumor volume similarly or more than standards of care (SOC) in A549 or MiaPaca2 xenografts in mice. Moreover, a 28-day rat toxicity study has shown very low toxicity (NOAEL=500 mg/Kg) good bioavailability and pharmacokinetic linearity, suggesting a broad therapeutic window. A FiM phase I clinical trial in patients with advanced cancer is scheduled to start in June 2013. Methods: Cellular assays were performed in A549 lung adenocarcinoma, and MiaPaca-2 pancreatic carcinoma cells. Cell proliferation was carried out by bromodeoxyuridine (BrdU) incorporation, cell viability by MTT, and protein expression and phosphorylation by immunoblotting. Cellular apoptosis was assessed both by caspase 3 immunoblot and Hoechst 3342 nuclear staining and quantification of nuclei; and autophagy by LC3-II lipidation assay in immunoblots. All studies were performed with ABTL0812 either alone or in combination with SOC. Results: ABTL0812 potentiated the cytotoxic effects of gemcitabine and docetaxel in MiaPaCa-2 and A549 cancer cells, respectively. In MTT assays, the IC50’s of gemcitabine and docetaxel decreased 7 and 80 times in MiaPaca-2 and A549 cells, respectively, when cells were co-incubated with non-cytotoxic ABTL0812 concentrations. Analysis of the activity (Chou and Talalay’s method) revealed that ABTL0812 synergizes with gemcitabine and docetaxel to promote cytotoxicity. We also present data showing the effects of gemcitabine and docetaxel on the molecular targets of ABTL0812 such as Akt and ribosomal S6 phosphorylation, DHFR expression and cellular autophagy. Conversely, we also show the effects of ABTL0182 on cellular apoptosis induced by gemcitabine and docetaxel. Conclusions: ABTL0812 synergistically potentiates the cytotoxic effect of gemcitabine and docetaxel in pancreatic and lung cancer cell models.

Cytotoxic activity and apoptosis-inducing potential of di-spiropyrrolidino and di-spiropyrrolizidino oxindole andrographolide derivatives.

Anticancer role of andrographolide is well documented. To find novel potent derivatives with improved cytotoxicity than andrographolide on cancer cells, two series of di-spiropyrrolidino- and di-spiropyrrolizidino oxindole andrographolide derivatives prepared by cyclo-addition of azomethine ylide along with sarcosine or proline (viz. sarcosine and proline series respectively) and substitution of different functional groups (-CH3, -OCH3 and halogens) were examined for their cytotoxic effect on a panel of six human cancer cell lines (colorectal carcinoma HCT116 cells, pancreatic carcinoma MiaPaCa-2 cells, hepatocarcinoma HepG2 cells, cervical carcinoma HeLa cells, lung carcinoma A549 and melanoma A375 cells). Except halogen substituted derivatives of proline series (viz. CY2, CY14 and CY15 for Br, Cl and I substitution respectively), none of the other derivatives showed improved cytotoxicity than andrographolide in the cancer cell lines examined. Order of cytotoxicity of the potent compounds is CY2>CY14>CY15>andrographolide. Higher toxicity was observed in HCT116, MiaPaCa-2 and HepG2 cells. CY2, induced death of HCT116 (GI50 10.5), MiaPaCa-2 (GI50 11.2) and HepG2 (GI50 16.6) cells were associated with cell rounding, nuclear fragmentation and increased percentage of apoptotic cells, cell cycle arrest at G1 phase, ROS generation, and involvement of mitochondrial pathway. Upregulation of Bax, Bad, p53, caspases-3,-9 and cleaved PARP; downregulation of Bcl-2, cytosolic NF-κB p65, PI3K and p-Akt; translocation of P53/P21, NF-κB p65 were seen in CY2 treated HCT116 cells. Thus, three halogenated di-spiropyrrolizidino oxindole derivatives of andrographolide are found to be more cytotoxic than andrographolide in some cancer cells. The most potent derivative, CY2 induced death of the cancer cells involves ROS dependent mitochondrial pathway like andrographolide.

Increased radiosensitivity and radiothermosensitivity of human pancreatic MIAPaCa-2 and U251 glioblastoma cell lines treated with the novel Hsp90 inhibitorNVP-HSP990

Background and purposeHeat shock Protein 90 (Hsp90) is a molecular chaperone that folds, stabilizes, and functionally regulates many cellular proteins involved in oncogenic signaling and in the regulation of radiosensitivity. It is upregulated in response to stress such a heat. Hyperthermia is a potent radiosensitizer, but induction of Hsp90 may potentially limit its efficacy. Our aim was to investigate whether the new Hsp90 inhibitor NVP-HSP990 increases radiosensitivity, thermosensitivity and radiothermosensitivity of human tumor cell lines.Material and methodsU251 glioblastoma and MIA PaCa-2 pancreatic carcinoma cells were used. To determine clonogenic survival, colony forming assays were performed. Cell viability and proliferation were assesed by Trypan blue staining. Cell cycle and apoptosis analyses were performed by flow cytometry. DAPI staining was used to detect mitotic catastrophe.ResultsNVP-HSP990 increased the thermosensitivity, radiosensitivity and radio-thermosensitivity of both cell lines in clonogenic assays. 72 hours after irradiation with 4 Gy, a significant reduction in cell number associated with considerable G2/M acumulation and mitotic catastrophe as well as cell death by apoptosis/necrosis was observed.ConclusionsTreatment with NVP-HSP990 strongly sensitized U251 and MIA PaCa-2 cells to hyperthermia and ionizing radiation or combination thereof through augmentation of G2/M arrest, mitotic catastrophe and associated apoptosis.

Development of a Novel Preclinical Pancreatic Cancer Research Model: Bioluminescence Image- Guided Focal Irradiation and Tumor Monitoring of Orthotopic Xenografts

We report on a novel preclinical pancreatic cancer research model that uses bioluminescence imaging (BLI)-guided irradiation of orthotopic xenograft tumors, sparing of surrounding normal tissues, and quantitative, noninvasive longitudinal assessment of treatment response. Luciferase-expressing MiaPaCa-2 pancreatic carcinoma cells were orthotopically injected in nude mice. BLI was compared to pathologic tumor volume, and photon emission was assessed over time. BLI was correlated to positron emission tomography (PET)/computed tomography (CT) to estimate tumor dimensions. BLI and cone-beam CT (CBCT) were used to compare tumor centroid location and estimate setup error. BLI and CBCT fusion was performed to guide irradiation of tumors using the small animal radiation research platform (SARRP). DNA damage was assessed by γ-H2Ax staining. BLI was used to longitudinally monitor treatment response. Bioluminescence predicted tumor volume (R = 0.8984) and increased linearly as a function of time up to a 10-fold increase in tumor burden. BLI correlated with PET/CT and necropsy specimen in size (P < .05). Two-dimensional BLI centroid accuracy was 3.5 mm relative to CBCT. BLI-guided irradiated pancreatic tumors stained positively for γ-H2Ax, whereas surrounding normal tissues were spared. Longitudinal assessment of irradiated tumors with BLI revealed significant tumor growth delay of 20 days relative to controls. We have successfully applied the SARRP to a bioluminescent, orthotopic preclinical pancreas cancer model to noninvasively: 1) allow the identification of tumor burden before therapy, 2) facilitate image-guided focal radiation therapy, and 3) allow normalization of tumor burden and longitudinal assessment of treatment response.

Bioluminescence image-guided irradiation and tumor monitoring in a preclinical pancreatic cancer mouse model.

192 Background: Preclinical pancreatic cancer animal models for radiation research are far from optimal because they utilize nonlocalized, single-beam irradiation of large fields due to lack of accurate targeting and delivery. We report on a novel preclinical pancreatic cancer research model that utilizes bioluminescence imaging (BLI)-guided irradiation (RT) of orthotopic xenograft tumors, sparing of surrounding normal tissues and quantitative, noninvasive longitudinal assessment of treatment response. Methods: In accordance with institutional guidelines, luciferase-expressing MiaPaCa-2 pancreatic carcinoma cells were used to generate orthotopic pancreatic tumors in nude mice. BLI of tumors were correlated to PET/CT and necropsy specimens using Pearson correlation. BLI was compared to cone-beam CT (CBCT) to determine the location of the tumor centroid and estimate an appropriate margin for radiation planning. Off-line fusion of BLI with CBCT was performed to guide radiation delivery to tumors using our small animal radiation research platform (SARRP). RT-induced DNA damage was assessed by γ-H2Ax and p-ATM foci. BLI was used to longitudinally monitor radiation treatment response and was correlated to necropsy specimen. Results: BLI accurately predicted tumor volume (R2 = 0.9961) and correlated well with PET/CT imaging of tumors (R2 = 0.97). BLI centroid accuracy was 3.5 mm relative to that of the CBCT. Irradiated pancreatic tumors stained positively for γ-H2Ax and p-ATM, while surrounding organs were spared. Longitudinal assessment of irradiated (5 Gy) tumors with BLI revealed a significant tumor growth delay of 20 days relative to untreated controls. This was also confirmed pathologically as mean tumor volume of irradiated mice was 30.2% that of unirradiated mice (p &lt; 0.05). Conclusions: We have developed a bioluminescent, orthotopic preclinical pancreas cancer model that allows noninvasive 1) normalizing of pretreatment tumor burden; 2) treatment planning and image-guided focal RT therapy; and 3) longitudinal assessment of treatment response. This unique translational model offers a means to investigate targeted and systemic agents with focused RT for pancreatic cancer. No significant financial relationships to disclose.

Study on Irradiated Injury of Human Pancreatic Carcinoma Cell Line MIA PaCa-2 Induced by High Dose per Fraction

Objective:To initially observe the cellular irradiated injury by high dose per fraction.Methods:We cultivated human pancreatic carcinoma MIA PaCa-2 cells and and divided them into 0,2,5,10,and 17 Gy groups.Cultivated cells were radiated by 6MV-X ray in one fraction with medical processing accelerator.We observed cellular morphous by histological technology after 24 hours.The degree of injury of DNA detected by comet assay instantly after radiation and by DNA ladder test at 6 and 12 hours after radiation.Changes in cell cycle were explored by flow cytometry at 0,6,12,24, and 36 hours after radiation.Results:After X-ray radiation,human pancreatic carcinoma cell line (MIA PaCa-2) were swelling. With the increase of radiation dose (less than 10 Gy),apoptotic necrosis and G2/M blockage of cell cycle was more obvious. When radiation dose was more than 10 Gy,the peak of apoptotic necrosis appeared early and obvious.The degree of DNA injury was most obvious when radiation dose was 10 Gyand was decreased when radiation dose was 17 Gy.When radiation dose was less than 10Gy,DNA ladder was single electrophoresis band.When radiation dose was 10Gy group, DNA ladder detection showed multiple typical ladder band.When radiation dose was more than 10Gy,vague irregular bands were observed.Conclusion:Different from conventional dose-fraction radiation,high dose per fraction causes oncotic necrosis as the main cell death type.

Abstract 5505: A genome-wide siRNA screen for novel regulators of HIF-1α activity in normoxia and hypoxia

Abstract The ability to survive hypoxic stress is an essential component of tumor development. Many rapidly proliferating solid tumors outgrow their vasculature while the abnormal tumor vasculature leads to small, transient pockets of hypoxic cells. In addition to being deprived of oxygen, these cells are also deprived of nutrients and unable to export harmful byproducts of cellular metabolism out of their immediate environment. One mechanism cancer cells employ to survive hypoxic stress is the stabilization and activation of the transcription factor hypoxia inducible factor 1α (HIF-1α), which translocates to the nucleus and induces pro-survival genes such as VEGF, Glut-1, and glycolytic enzymes. MiaPaCa-2 pancreatic carcinoma cells stably transfected with a 5X hypoxia response element (HRE) promoter regulating the firefly luciferase gene were generated, and shown to express luciferase only when HIF-1α was stabilized in hypoxia(1% O2). Using these cells, a genome wide siRNA screen was performed using the Dharmacon 22,000 gene siRNA library under the conditions of normoxia, 16hr and 72 hr hypoxia, to discover novel effectors of the HIF-1α pathway. Luciferase expression was corrected for cell number using a WST-1 cell proliferation assay prior to luciferase detection. Several hits were identified including genes which, when silenced, both increased and decreased HIF-1α transcriptional activity. Genes whose inhibition increased HIF-1α transcriptional activity in normoxia, in some cases up to 19 fold, include members of the E3 ubiquitin ligase complex which bind to and degrade HIF-1α under normal oxygen tensions, and also a number of other genes with uncharacterized function. There were also genes whose inhibition decreased hypoxia induced HIF-1α activity. Many were not well characterized, but there were a number of genes belonging to the MAP kinase pathway; the DNA repair pathway; the NF-κB pathway; and glycolysis genes, that were identified as necessary for HIF-1α transcriptional activity. Hits in these pathways were validated by secondary siRNAs and Western blots. It was discovered that silencing key genes involved in glycolysis inhibited HIF-1α transcriptional activity due to a decrease in HIF-1α protein levels. They include hexokinase-1, pyruvate dependent kinases-1,2 and 3, and 6-phosphofructo-1-kinase(M). These results suggest that increased glycolysis found in many tumors under aerobic conditions (the Warburg effect), which has been suggested to be caused by increased Myc expression, mutant Ras, mutant p53 and PI-3-kinase signaling, has an important role in increasing HIF-1α expression and activity. This stabilization and increase in activity then further induces the expression of target glycolytic genes and glycolytic activity in a feed-forward loop. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5505.