Effect of inhibition of poly-(ADP ribose) polymerase on gemcitabine and radiation-induced cytotoxicity of pancreatic cancer cells.

203 Background: Poly-(ADP ribose) polymerases (PARPs) are DNA-binding proteins involved in DNA repair. PARP inhibition has resulted in excellent antitumor activity when used with other cytotoxic therapies. ABT-888 is a promising PARP inhibitor with excellent potency against the PARP-1/2 enzymes and good oral bioavailability. We attempt to determine whether PARP-1/2 inhibition alone, or in combination with gemcitabine, will enhance the effects of irradiation (RT) of pancreatic cancer cells. Methods: The pancreatic carcinoma cell lines, MiaPaCa-2 and Panc02, were treated with ABT-888, gemcitabine, RT, or combinations thereof. RT was delivered with a 137-Cs Gammacell in a single fraction. Cells were pre-treated once with ABT-888 and/or gemcitabine 30 minutes prior to RT. Viability was assessed through reduction of resazurin into fluorescent resorufin. Levels of apoptosis were determined by measuring caspase-3/7 activity using a luminescent assay. PARP activity was determined using a chemiluminescent PAR elisa. Results: The half maximal inhibitory concentration (IC50) of RT was 5 Gy; IC10 for ABT-888 and gemcitabine were 10 uM and 5 nM, respectively. Treatment with ABT-888 (10 uM), gemcitabine (5 nM), or combinations of the two with RT led to increasingly higher rates of cell death 8 days after treatment (p<0.001). RT dose enhancement factors were 1.5, 1.82 and 2.36 for 1, 10 and 100 uM ABT-888, respectively. Minimal cytotoxicity was noted when cells were treated with ABT-888 alone up to 100 uM. Caspase activity was not significantly increased when treated with ABT-888 (10 uM) alone (1.28 fold, p=0.077), but became significant when RT (2 Gy) was added (2.03 fold, p=0.006). This difference was further enhanced by the addition of gemcitabine (2.95 fold, p=0.004). Conclusions: ABT-888 is a potent radiosensitizer of pancreatic cancer cells with minimal cytotoxicity when used alone. Cell death is further potentiated by cotreatment with gemcitabine. Radiation-induced apoptosis was significantly enhanced by ABT-888 and gemcitabine, suggesting a synergistic mechanism of interference with DNA repair. These data are currently being validated in an orthotopic pancreatic cancer mouse model. No significant financial relationships to disclose.

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Inhibition of Radiation-Induced DNA Repair and Prosurvival Pathways Contributes to Vorinostat-Mediated Radiosensitization of Pancreatic Cancer Cells

Pancreas ◽

10.1097/mpa.0b013e3181dd63e1 ◽

2010 ◽

Vol 39 (8) ◽

pp. 1277-1283 ◽

Cited By ~ 12

Author(s):

Amit Deorukhkar ◽

Shujun Shentu ◽

Hee Chul Park ◽

Parmeswaran Diagaradjane ◽

Vinay Puduvalli ◽

...

Keyword(s):

Pancreatic Cancer ◽

Dna Repair ◽

Cancer Cells ◽

Pancreatic Cancer Cells ◽

Radiation Induced

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Abstract 1995: HuR dependent inhibition of PARG enhances PARP inhibitor therapy for DNA repair proficient and deficient pancreatic cancer cells

10.1158/1538-7445.am2016-1995 ◽

2016 ◽

Author(s):

Saswati N. Chand ◽

Mahsa Zarei ◽

Akshay R. Kamath ◽

Matthew J. Schiewer ◽

Carmella Romeo ◽

...

Keyword(s):

Pancreatic Cancer ◽

Dna Repair ◽

Cancer Cells ◽

Parp Inhibitor ◽

Inhibitor Therapy ◽

Pancreatic Cancer Cells ◽

Dependent Inhibition

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Evaluating the Sensitivity of Sporadic Pancreatic Cancer to poly(ADP-ribose) polymerase (PARP) Inhibition (Velaparib, Olaparib, AG14361) as Single Agents and as Chemo-sensitizers

10.1101/2020.03.28.013763 ◽

2020 ◽

Author(s):

J. Angel de Soto

Keyword(s):

Pancreatic Cancer ◽

Cancer Cells ◽

Cell Lines ◽

Pancreatic Cancer Cell ◽

Parp Inhibitor ◽

Parp Inhibitors ◽

Human Pancreatic Cancer ◽

Parp Inhibition ◽

Pancreatic Cancer Cells ◽

Ic50 Values

AbstractAfter resection of pancreatic cancer local recurrence occurs in 50%-80% of the cases while metastasis develops 75% of the time. Current, adjuvant therapy often consists of gemcitabine, cisplatin and/or 5-fluorouracil which add a modest increase in median survival by 4-5 months. In this study, we treated human pancreatic cancer cells with poly (ADP-ribose) polymerase (PARP) Inhibitors (AG14361, Veliparib and Olaparib) alone or with gemcitabine, cisplatin or 5 – fluorouracil. Methods: CFPAC-1 and BXPC-3, HPAC human pancreatic cancer cell lines were treated for 72 hours with PARP inhibitors alone or in combination with gemcitabine, cisplatin, or 5 – fluorouracil. Validated MTT assays were used to form dose response curves from which the IC50 values were calculated. Results: The PARP1 IC50 values for CFPAC-1, BXPC-3 and HPAC pancreatic cancer cell lines were AG14361 (14.3 μM, 12.7 μM, 38.3 μM), Veliparib (52.6 μM, 100.9 μM 102.0 μM) and Olaparib (79.5 μM, 184.8 μM, 200.2 μM). The IC50 values of cisplatin, were decreased up to 60 fold in the presence of clinically relevant amounts of PARP inhibitor while 5-flourouracil IC50 values were decreased up to 6000 fold in the presence of clinically relevant amounts of PARP inhibitor. Gemcitabine was inhibited up to 73% by PARP inhibitors. Conclusions: Sporadic human pancreatic cancer cells are sensitive to PARP inhibition. PARP inhibitors significantly enhanced the cytotoxicity of cisplatin and 5-fluorouracil while inhibiting gemcitabine. There is little correlation between endogenous PARP activity and the effectiveness of PARP inhibitors.

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ATM-deficient lung, prostate and pancreatic cancer cells are acutely sensitive to the combination of olaparib and the ATR inhibitor AZD6738

10.1101/2020.03.13.991166 ◽

2020 ◽

Author(s):

Nicholas R. Jette ◽

Suraj Radhamani ◽

Ruiqiong Ye ◽

Yaping Yu ◽

Greydon Arthur ◽

...

Keyword(s):

Lung Cancer ◽

Pancreatic Cancer ◽

Cell Death ◽

Cancer Cells ◽

Parp Inhibitor ◽

Lung Cancer Cells ◽

Ataxia Telangiectasia Mutated ◽

Pancreatic Cancer Cells ◽

Atm Protein ◽

A549 Lung

AbstractBackgroundThe ataxia telangiectasia mutated (ATM) protein kinase is mutated in several human cancers, presenting potential opportunities for targeted cancer therapy. We previously reported that the poly-ADP ribose polymerase (PARP) inhibitor olaparib induced transient G2 arrest but not cell death in ATM-deficient A549 lung cancer cells, while the combination of olaparib with the ATM-, Rad3-related (ATR) inhibitor VE-821 induced cell death. Here, we show that the clinically relevant ATR inhibitor, AZD6738, sensitizes ATM-deficient A549 lung, prostate and pancreatic cancer cells to olaparib.MethodsATM was depleted from A549 lung cancer cells, PC-3 prostate cancer cells and Panc 10.05 pancreatic cancer cells, and the effects of olaparib alone and in combination with AZD6738 were determined.ResultsThe combination of olaparib plus AZD6738 induced cell death in ATM-deficient lung, prostate and pancreatic cancer cells with little effect on their ATM-proficient counterparts.ConclusionsLung, prostate and pancreatic patients whose tumours exhibit loss or inactivation of ATM may benefit from combination of a PARP inhibitor plus an ATR inhibitor.

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Evaluating the Sensitivity of Sporadic Pancreatic Cancer to Poly(ADPribose) Polymerase (PARP) Inhibition (Velaparib, Olaparib, AG14361) as Single Agents and as Chemo-sensitizers

10.47363/jcrr/2020(2)119 ◽

2020 ◽

Vol 2 (2) ◽

pp. 1-6

Author(s):

Joseph Angel de Soto ◽

Keyword(s):

Pancreatic Cancer ◽

Cancer Cells ◽

Cell Lines ◽

Pancreatic Cancer Cell ◽

Parp Inhibitor ◽

Parp Inhibitors ◽

Human Pancreatic Cancer ◽

Parp Inhibition ◽

Pancreatic Cancer Cells ◽

Ic50 Values

After resection of pancreatic cancer local recurrence occurs in 50%-80% of the cases while metastasis develops 75% of the time. Current, adjuvant therapy often consists of gemcitabine, cisplatin and/or 5-fluorouracil which add a modest increase in median survival by 4-5 months. In this study, we treated human pancreatic cancer cells with poly (ADP-ribose) polymerase (PARP) Inhibitors (AG14361, Veliparib and Olaparib) alone or with gemcitabine, cisplatin or 5-fluorouracil. Methods: CFPAC-1 and BXPC-3, HPAC human pancreatic cancer cell lines were treated for 72 hours with PARP inhibitors alone or in combination with gemcitabine, cisplatin, or 5 – fluorouracil. Validated MTT assays were used to form dose response curves from which the IC50 values were calculated. Results: The PARP1 IC50 values for CFPAC-1, BXPC-3 and HPAC pancreatic cancer cell lines were AG14361 (14.3 µM, 12.7 µM, 38.3 µM), Veliparib (52.6 µM, 100.9 µM 102.0 µM) and Olaparib (79.5 µM, 184.8 µM, 200.2 µM). The IC50 values of cisplatin, were decreased up to 60 fold in the presence of clinically relevant amounts of PARP inhibitor while 5-flourouracil IC50 values were decreased up to 6000 fold in the presence of clinically relevant amounts of PARP inhibitor. Gemcitabine was inhibited up to 73% by PARP inhibitors. Conclusions: Sporadic human pancreatic cancer cells are sensitive to PARP inhibition. PARP inhibitors significantly enhanced the cytotoxicity of cisplatin and 5-fluorouracil while inhibiting gemcitabine. There is little correlation between endogenous PARP activity and the effectiveness of PARP inhibitors.

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Galectin-3 is modulated in pancreatic cancer cells under hypoxia and nutrient deprivation

Biological Chemistry ◽

10.1515/hsz-2019-0413 ◽

2020 ◽

Vol 401 (10) ◽

pp. 1153-1165 ◽

Cited By ~ 2

Author(s):

Antônio F. da Silva Filho ◽

Lucas B. Tavares ◽

Maira G. R. Pitta ◽

Eduardo I. C. Beltrão ◽

Moacyr J. B. M. Rêgo

Keyword(s):

Pancreatic Cancer ◽

Cell Death ◽

Mrna Expression ◽

Cancer Cells ◽

Ductal Adenocarcinoma ◽

Reverse Transcription Pcr ◽

Pancreatic Cancer Cells ◽

Through Flow ◽

Galectin 3

AbstractPancreatic ductal adenocarcinoma is one of the most aggressive tumors with a microenvironment marked by hypoxia and starvation. Galectin-3 has been evaluated in solid tumors and seems to present both pro/anti-tumor effects. So, this study aims to characterize the expression of Galectin-3 from pancreatic tumor cells and analyze its influence for cell survive and motility in mimetic microenvironment. For this, cell cycle and cell death were accessed through flow cytometry. Characterization of inside and outside Galectin-3 was performed through Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), immunofluorescence, Western blot, and ELISA. Consequences of Galectin-3 extracellular inhibition were investigated using cell death and scratch assays. PANC-1 showed increased Galectin-3 mRNA expression when cultivated in hypoxia for 24 and 48 h. After 24 h in simultaneously hypoxic/deprived incubation, PANC-1 shows increased Galectin-3 protein and secreted levels. For Mia PaCa-2, cultivation in deprivation was determinant for the increasing in Galectin-3 mRNA expression. When cultivated in simultaneously hypoxic/deprived condition, Mia PaCa-2 also presented increasing for the Galectin-3 secreted levels. Treatment of PANC-1 cells with lactose increased the death rate when cells were incubated simultaneously hypoxic/deprived condition. Therefore, it is possible to conclude that the microenvironmental conditions modulate the Galectin-3 expression on the transcriptional and translational levels for pancreatic cancer cells.

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Bak expression and cell death occur in peritumorous tissue but not in pancreatic cancer cells,

Journal of Gastrointestinal Surgery ◽

10.1016/s1091-255x(99)80012-2 ◽

1999 ◽

Vol 3 (1) ◽

pp. 74-81 ◽

Cited By ~ 12

Author(s):

H Graber

Keyword(s):

Pancreatic Cancer ◽

Cell Death ◽

Cancer Cells ◽

Pancreatic Cancer Cells

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Veliparib Is an Effective Radiosensitizing Agent in a Preclinical Model of Medulloblastoma

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.633344 ◽

2021 ◽

Vol 8 ◽

Author(s):

Jessica Buck ◽

Patrick J. C. Dyer ◽

Hilary Hii ◽

Brooke Carline ◽

Mani Kuchibhotla ◽

...

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Combination Therapy ◽

Cellular Response ◽

Molecular Subtype ◽

Parp Inhibitor ◽

Single Agent ◽

Parp Inhibition ◽

Preclinical Model ◽

Radiation Induced

Medulloblastoma is the most common malignant childhood brain tumor, and 5-year overall survival rates are as low as 40% depending on molecular subtype, with new therapies critically important. As radiotherapy and chemotherapy act through the induction of DNA damage, the sensitization of cancer cells through the inhibition of DNA damage repair pathways is a potential therapeutic strategy. The poly-(ADP-ribose) polymerase (PARP) inhibitor veliparib was assessed for its ability to augment the cellular response to radiation-induced DNA damage in human medulloblastoma cells. DNA repair following irradiation was assessed using the alkaline comet assay, with veliparib inhibiting the rate of DNA repair. Veliparib treatment also increased the number of γH2AX foci in cells treated with radiation, and analysis of downstream pathways indicated persistent activation of the DNA damage response pathway. Clonogenicity assays demonstrated that veliparib effectively inhibited the colony-forming capacity of medulloblastoma cells, both as a single agent and in combination with irradiation. These data were then validated in vivo using an orthotopic implant model of medulloblastoma. Mice harboring intracranial D425 medulloblastoma xenografts were treated with vehicle, veliparib, 18 Gy multifractionated craniospinal irradiation (CSI), or veliparib combined with 18 Gy CSI. Animals treated with combination therapy exhibited reduced tumor growth rates concomitant with increased intra-tumoral apoptosis observed by immunohistochemistry. Kaplan–Meier analyses revealed a statistically significant increase in survival with combination therapy compared to CSI alone. In summary, PARP inhibition enhanced radiation-induced cytotoxicity of medulloblastoma cells; thus, veliparib or other brain-penetrant PARP inhibitors are potential radiosensitizing agents for the treatment of medulloblastoma.

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