Novel PAK4 inhibitors for pancreatic cancer therapy.

2014 ◽  
Vol 32 (3_suppl) ◽  
pp. 233-233 ◽  
Author(s):  
Asfar S. Azmi ◽  
William Senapedis ◽  
Erkan Baloglu ◽  
Yosef Landesman ◽  
Ori Kalid ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Rna Interference ◽  
Cell Lines ◽  
Gene Copy Number ◽  
Maximum Tolerated Dose ◽  
Gene Copy ◽  
Allosteric Modulator ◽  
Ras Signaling ◽  
Mice Model ◽  
P21 Activated Kinase

233 Background: Pancreatic cancer (PC) is a deadly disease in urgent need of novel molecularly targeted drugs. Gene copy number amplification studies in PC patient cohorts has shown amplification of the p21-activated kinase (PAK) family member PAK4. PAK4 acts as a key effector of the Rho family GTPases downstream of Ras signaling. Moreover, PAK4 protein is over-expressed in PC cell lines but not in normal human pancreatic ductal epithelial (HPDE) cells. Most importantly, RNA interference of PAK4 has been shown to suppress PC cell proliferation. These studies clearly make PAK4 an attractive therapeutic target especially because direct targeting of Kras has been a failure. Methods: We have identified a new class of PAK4 allosteric modulators that show anti-proliferative activity against several PC cell lines (IC50s <250nM) while sparing normal HPDE (IC50s5 fold higher). Results: Cell growth inhibition is concurrent with apoptosis induction and suppression of colony formation in the PC cell lines (and not in HPDE cells). Our small molecule PAK4 allosteric modulator, KPT-7189, suppresses PAK4 protein expression and caused reversal of anti-apoptotic signaling. PAK4 RNA interference enhances KPT-7189 activity, and co-immunoprecipitation experiments showed disruption of PAK4 binding partners. KPT-7189 also inhibited spheroid forming ability of highly resistant PC cells carrying markers of cancer stem cells (CSCs;triple positive for CD33+CD44+EpCAM+) consistent with epithelial-to-mesenchymal (EMT) phenotype. Molecular analyses of KPT-7189 treated CD33+CD44+EpCAM+ spheroids showed suppression of EMT and CSC markers with re-expression of epithelial phenotype markers. Another potent PAK allosteric modulator in the same series, KPT-7651 showing good oral bioavailability (%F = 95%) was well tolerated by mice with a maximum tolerated dose of 60 mg/kg following oral administration. Pre-clinical animal efficacy trial in sub-cutaneous, orthotopic and LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre transgenic mice model is currently under investigation. Conclusions: This is the first proof of concept study demonstrating the development of a PAK4-targeted drug for the treatment of PC, and thus further pre-clinical and clinical investigations are warranted.

scholarly journals An Efficient Photodynamic Therapy Treatment for Human Pancreatic Adenocarcinoma

2020 ◽  
Vol 9 (1) ◽  
pp. 192 ◽  
Author(s):  
Alexandre Quilbe ◽  
Olivier Moralès ◽  
Martha Baydoun ◽  
Abhishek Kumar ◽  
Rami Mustapha ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Photodynamic Therapy ◽  
Immune System ◽  
Cancer Cells ◽  
Pancreatic Adenocarcinoma ◽  
Cell Lines ◽  
Folate Receptor ◽  
Mice Model ◽  
Gene And Protein Expression ◽  
The Impact

To date, pancreatic adenocarcinoma (ADKP) is a devastating disease for which the incidence rate is close to the mortality rate. The survival rate has evolved only 2–5% in 45 years, highlighting the failure of current therapies. Otherwise, the use of photodynamic therapy (PDT), based on the use of an adapted photosensitizer (PS) has already proved its worth and has prompted a growing interest in the field of oncology. We have developed a new photosensitizer (PS-FOL/PS2), protected by a recently published patent (WO2019 016397-A1, 24 January 2019). This photosensitizer is associated with an addressing molecule (folic acid) targeting the folate receptor 1 (FOLR1) with a high affinity. Folate binds to FOLR1, in a specific way, expressed in 100% of ADKP or over-expressed in 30% of cases. The first objective of this study is to evaluate the effectiveness of this PS2-PDT in four ADKP cell lines: Capan-1, Capan-2, MiapaCa-2, and Panc-1. For this purpose, we first evaluated the gene and protein expression of FOLR1 on four ADKP cell lines. Subsequently, we evaluated PS2’s efficacy in our cell lines and we assessed the impact of PDT on the secretome of cancer cells and its impact on the immune system. Finally, we evaluate the PDT efficacy on a humanized SCID mouse model of pancreatic cancer. In a very interesting way, we observed a significant increase in the proliferation of activated-human PBMC when cultured with conditioned media of ADKP cancer cells subjected to PDT. Furthermore, to evaluate in vivo the impact of this new PS, we analyzed the tumor growth in a humanized SCID mice model of pancreatic cancer. Four conditions were tested: Untreated, mice (nontreated), mice with PS (PS2), mice subjected to illumination (Light only), and mice subjected to illumination in the presence of PS (PDT). We noticed that the mice subjected to PDT presented a strong decrease in the growth of the tumor over time after illumination. Our investigations have not only suggested that PS2-PDT is an effective therapy in the treatment of PDAC but also that it activates the immune system and could be considered as a real adjuvant for anti-cancer vaccination. Thus, this new study provides new treatment options for patients in a therapeutic impasse and will provide a new arsenal in the fight against PDAC.

Mathematical models of gene amplification with applications to cellular drug resistance and tumorigenicity.

Genetics ◽  
1990 ◽  
Vol 125 (3) ◽  
pp. 633-644
Author(s):  
M Kimmel ◽  
D E Axelrod
Keyword(s):  
Mathematical Models ◽  
Cell Lines ◽  
Gene Amplification ◽  
Dihydrofolate Reductase ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Published Data ◽  
Reductase Gene ◽  
Double Minute ◽  
Double Minute Chromosomes

Abstract An increased number of copies of specific genes may offer an advantage to cells when they grow in restrictive conditions such as in the presence of toxic drugs, or in a tumor. Three mathematical models of gene amplification and deamplification are proposed to describe the kinetics of unstable phenotypes of cells with amplified genes. The models differ in details but all assume probabilistic mechanisms of increase and decrease in gene copy number per cell (gene amplification/deamplification). Analysis of the models indicates that a stable distribution of numbers of copies of genes per cell, observed experimentally, exists only if the probability of deamplification exceeds the probability of amplification. The models are fitted to published data on the loss of methotrexate resistance in cultured cell lines, due to the loss of amplified dihydrofolate reductase gene. For two mouse cell lines unstably resistant to methotrexate the probabilities of amplification and deamplification of the dihydrofolate reductase gene on double minute chromosomes are estimated to be approximately 2% and 10%, respectively. These probabilities are much higher than widely presumed. The models explain the gradual disappearance of the resistant phenotype when selective pressure is withdrawn, by postulating that the rate of deamplification exceeds the rate of amplification. Thus it is not necessary to invoke a growth advantage of nonresistant cells which has been the standard explanation. For another analogous process, the loss of double minute chromosomes containing the myc oncogene from SEWA tumor cells, the growth advantage model does seem to be superior to the amplification and deamplification model. In a more theoretical section of the paper, it is demonstrated that gene amplification/deamplification can result in reduction to homozygosity, such as is observed in some tumors. Other applications are discussed.

scholarly journals Genome-wide gene copy number and expression analysis of primary gastric tumors and gastric cancer cell lines

BMC Cancer ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Siina Junnila ◽  
Arto Kokkola ◽  
Marja-Liisa Karjalainen-Lindsberg ◽  
Pauli Puolakkainen ◽  
Outi Monni
Keyword(s):  
Gastric Cancer ◽  
Cell Lines ◽  
Cancer Cell ◽  
Expression Analysis ◽  
Copy Number ◽  
Gastric Cancer Cell ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Genome Wide ◽  
Gastric Cancer Cell Lines

Identification of chromosomal regions that harbor novel genes important for pancreatic cancer pathogenesis by genome-wide screening methods

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15609-e15609
Author(s):  
S. Thieltges ◽  
T. Kalinina ◽  
A. Krohn ◽  
R. Simon ◽  
M. Moeller-Krull ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Signaling Pathways ◽  
Cell Lines ◽  
Expression Profile ◽  
Gene Copy ◽  
Fish Analysis ◽  
Rna Expression ◽  
Tumor Type ◽  
Primary Tumors ◽  
Genome Wide

e15609 Background: Pancreatic adenocarcinoma is a genetically highly complex and heterogenous tumor type with strong genetic instability which makes it resistant to therapy. Known amplifications of oncogenes such as KRAS or MYC and deletions of tumor suppresor genes such as CDKN2A and SMAD4 have demonstrated the importance of genetic alteration in this tumor type. Methods: We report the use of an Affymetrix Genome-Wide Human single nucleotide polymorphism (SNP) Array 6.0 (906,600 SNPs) to screen for gene copy number changes and allelic imbalances in 8 microdissected primary pancreatic tumors and 7 established pancreatic cancer cell lines. Gene Chip Human Genome U133 2.0 Array was used to make an RNA expression profile. Mutation analysis of KRAS and M-FISH analysis of cell lines was performed. Results: SNP arrays confirmed the presence of previously reported cytogenetic abnormalities in the cell lines and primary tumor probes, including MYC amplifikation at 8q24, gain of 17q12 (ERBB2/HER2), 7p12 (EGFR) and 12p12.1 (KRAS). KRAS mutation was seen in 71% of cell lines (5/7). We identified several alterations in signaling pathways such as Wnt/Notch Signaling and KRAS signaling. A sizeable subset ( 7 of 15 cases; 47%) showed an amplikon at 19q13.1–13.2 in which the serine/threonine kinase Mirk/Dyrk1B is localized, a downstream effector of oncogenic k-ras. There was also strong concordance between primary tumors and cell lines with respect to gains on 8q, 12p and 18q. Analysis of gene expression was used to localize potential target genes. M-FISH analysis showed complex karyotypes with chromosomal deletions in 9p and 18q, regions that are known to harbor tumor suppressor genes (CDKN2A, SMAD4 and TP53). Conclusions: Several signaling pathways mediate tumor cell survival. Analysis of gene amplification and RNA expression profile provide molecular biological characteristics and an individual gene signature of the tumor which allow us to choose more efficient drugs to an individualized treatment. Pathways activated by KRAS such as DYRK1B may offer new therapeutic targets. Further functional characterization is needed to provide evidence for the actual role of any putative target gene. No significant financial relationships to disclose.

scholarly journals Endogenous RNA interference is driven by copy number

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Cristina Cruz ◽  
Jonathan Houseley
Keyword(s):  
Rna Interference ◽  
Transposable Elements ◽  
Copy Number ◽  
Defense Mechanism ◽  
Gene Copy Number ◽  
Single Copy ◽  
Gene Copy ◽  
Protein Coding ◽  
Endogenous Loci ◽  
Pervasive Transcription

A plethora of non-protein coding RNAs are produced throughout eukaryotic genomes, many of which are transcribed antisense to protein-coding genes and could potentially instigate RNA interference (RNAi) responses. Here we have used a synthetic RNAi system to show that gene copy number is a key factor controlling RNAi for transcripts from endogenous loci, since transcripts from multi-copy loci form double stranded RNA more efficiently than transcripts from equivalently expressed single-copy loci. Selectivity towards transcripts from high-copy DNA is therefore an emergent property of a minimal RNAi system. The ability of RNAi to selectively degrade transcripts from high-copy loci would allow suppression of newly emerging transposable elements, but such a surveillance system requires transcription. We show that low-level genome-wide pervasive transcription is sufficient to instigate RNAi, and propose that pervasive transcription is part of a defense mechanism capable of directing a sequence-independent RNAi response against transposable elements amplifying within the genome.

Role of EGFR but not HER2 or HER3 gene copy number in predicting sensitivity of head and neck squamous cell carcinoma (SCCHN) cell lines to EGFR tyrosine kinase inhibitors

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 6063-6063
Author(s):  
M. Varella-Garcia ◽  
K. Acheson ◽  
G. B. Marshall ◽  
R. M. McCormack ◽  
A. Ryan ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cell Lines ◽  
Copy Number ◽  
Kinase Inhibitors ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Sensitive Cell ◽  
Egfr Gene ◽  
Egfr Tyrosine Kinase Inhibitors ◽  
Egfr Tkis

6063 Background: EGFR gene copy number has previously been reported to predict for improved overall survival in NSCLC patients treated with gefitinib (IRESSA) or erlotinib compared with placebo [JCO 2006;24:5034–42 & N Engl J Med 2005;353:133–44]. The utility of EGFR gene copy number as a predictive biomarker in other tumour types such as squamous cell carcinoma of the head and neck (SCCHN) is currently under clinical investigation. The present study examined a panel of 20 SCCHN cell lines to identify potential biomarkers predicting in vitro sensitivity to EGFR tyrosine kinase inhibitors (TKIs). Methods: A panel of 20 SCCHN cell lines was screened for sensitivity to gefitinib, vandetanib or erlotinib using a viable cell number endpoint, with G150 values determined for each cell line (inhibitor concentration required to give 50% growth inhibition). Cell lines were blinded and assessed for EGFR, HER2 and HER3 protein expression by ELISA, mutation status by dye-terminator sequencing, and gene copy number by fluorescence in situ hybridisation (FISH). Results: A broad range in sensitivity was observed for all compounds across the panel of 20 SCCHN cell lines (G150 ranging from 0.001uM to =10uM). 12 cell lines were positive for EGFR genomic gain. Sensitivity (GI50 <1uM) to all EGFR TKIs was seen in 11 lines and resistance (GI50 >8uM) in 5 lines. Of the sensitive cell lines, 9 were positive for EGFR genomic gain compared with only 1 of the resistant lines. Furthermore, EGFR protein expression also had a direct association with EGFR TKI sensitivity. In contrast, only 4 cell lines were positive for HER2 or HER3 genomic gain and there was no correlation with sensitivity. The most sensitive cell line was positive for EGFR genomic gain and was the only line to have an EGFR TK mutation (S768I in exon 20). Conclusions: EGFR gene copy number and protein expression appeared to have predictive value in identifying SCCHN cell lines sensitive to EGFR TKIs. No significant financial relationships to disclose.

The synthesis of ribosomal proteins S16 and L32 is not autogenously regulated during mouse myoblast differentiation

1987 ◽  
Vol 7 (12) ◽  
pp. 4464-4471
Author(s):  
L H Bowman
Keyword(s):  
Cell Lines ◽  
Rna Processing ◽  
Copy Number ◽  
Ribosomal Proteins ◽  
Protein Gene ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Myoblast Differentiation ◽  
Myoblast Cell ◽  
Mouse Myoblast

A series of mouse myoblast cell lines was constructed that contain 1 to 34 extra copies of either the S16 or the L32 ribosomal protein (r-protein) gene. The metabolism of the S16 and L32 r-proteins and mRNAs was examined in myoblasts and fibers of these cell lines to determine whether the synthesis of these r-proteins is autogenously regulated. The incorporation of extra copies of these r-protein genes into the genome resulted in the accumulation of the corresponding mRNAs to levels that were directly proportional to the gene copy number. The levels of the overproduced mRNAs decreased after the differentiation of mouse myoblasts into fibers in parallel to the decrease in the levels of the endogenous r-protein mRNAs. These results indicate that the synthesis of these r-proteins is not autogenously regulated at the level of transcription, RNA processing, or mRNA stability. To determine whether the synthesis of these r-proteins is regulated at the level of translation, the translational efficiencies of the overproduced mRNAs were inferred from their distribution in polysomal gradients. The translational efficiencies of these overproduced r-protein mRNAs in myoblasts are similar to those of the endogenous r-protein mRNAs. After myoblast differentiation, the translational efficiencies of the overproduced r-protein mRNAs decrease exactly like those of the endogenous r-protein mRNAs. Examination of the synthesis and stability of r-proteins in one of the L32-overproducing cell lines demonstrated that the overproduced L32 r-protein degrades shortly after its synthesis. The synthesis and stability of the other r-proteins were unaffected in this cell line. Thus, the synthesis of S16 and L32 r-proteins is not autogenously regulated at any level in either myoblasts or fibers.

Sign in / Sign up

Export Citation Format

Share Document