Northern blot analysis for detection and quantification of RNA in pancreatic cancer cells and tissues

2008 ◽  
Vol 4 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Sylvia Streit ◽  
Christoph W Michalski ◽  
Mert Erkan ◽  
Jörg Kleeff ◽  
Helmut Friess
2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15727-e15727
Author(s):  
Sunanda Singh ◽  
Genoveva Murillo ◽  
Avani Singh ◽  
Samara Singh ◽  
Meenakshi S Parihar ◽  
...  

e15727 Background: Over 90% of pancreatic cancers have KRAS mutations and hyper-expression of P-STAT3 oncoproteins, which if specifically targeted may help treatment of pancreatic cancers. Singh Biotechnology’s proprietary technology engineered SBT-100, a single domain antibody that is bispecific for KRAS & STAT3, which can cross the cell membranes and bind to these intracellular oncoproteins. Combining this targeted therapy with an established chemotherapy, such as gemcitabine, may improve patient’s response to treatment. Methods: Human pancreatic cancer cells (PANC-1 and BX-PC3) were used. Biacore assay demonstrates SBT-100 binding to KRAS, KRAS (G12D), and STAT3. Immunoprecipitation (IP) and western blot analysis confirmed binding to STAT3 by SBT-100. Pancreatic cancer cells were treated at varying doses of SBT-100 ranging from 0µg/ml to 200µg/ml ± gemcitabine, and after 72 hours growth inhibition was determined by a MTT assay. PANC-1 tumors were grown in athymic nude mice, divided into four groups and staged to a range of 100-150mm3 before treatment. Groups were: vehicle only, SBT-100, gemcitabine, and SBT-100 & gemcitabine. Animals received treatments for 14 days, then monitored for 7 days. Results: Biacore study shows SBT-100 binds KRAS with an affinity of 10-9M, KRAS (G12D) with 10-8M, and STAT3 with 10-8M. IP and western blot analysis demonstrates that SBT-100 binds P-STAT3. MTT assay demonstrates SBT-100 inhibits the growth of PANC-1 and BX-PC3 (p < 0.001). In PANC1 cells a combination of SBT-100 & gemcitabine demonstrates synergism in inhibiting growth of PANC-1, even at 1/8th the gemcitabine IC50 concentration. PANC-1 xenograft study demonstrates that combination therapy of SBT-100 & gemcitabine is superior to either SBT-100 or gemcitabine alone. Compared to the vehicle group, SBT-100 & gemcitabine is far superior (p < 0.001) and gives statistically significant suppression of pancreatic cancer growth in vivo. Conclusions: Targeted therapy for KRAS and P-STAT3 expressing tumors with SBT-100 & gemcitabine is synergistic for the treatment of pancreatic cancer. This study suggests that synergism maybe achieved with lower doses of gemcitabine, thereby reducing toxicity in patients.


2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 216-216
Author(s):  
J. G. Trevino ◽  
S. R. Pillai ◽  
S. P. Chellappan

216 Background: The signaling pathways contributing to DNA-binding protein inhibitor Id1 expression and chemoresistance in pancreatic cancer remain unknown. Id1 plays a role in pancreatic tumor progression with tumor-promoting effects of nicotine regulating protein tyrosine kinase Src activation and Id1 expression, both associated with chemoresistance in other systems. We hypothesize Id1 expression regulates chemoresistance in pancreatic cancer through a nicotine-promoting Src-dependent pathway. Methods: We probed pancreatic cancer cell lines (L3.6pl, PANC-1, Mia-PaCa-2) for innate gemcitabine chemoresistance with cell viability MTT assay and western blot analysis of PARP cleavage programmed cell death. Gemcitabine-sensitive cells were exposed to rising gemcitabine concentrations to establish a resistant subtype, L3.6plGemRes. Protein analysis and mRNA expression were determined by western blot analysis and RT-PCR respectively. Induction of Src phosphorylation or Id1 expression was performed with nicotine (1 μM). Results: Inhibition of c-Src expression was performed with short-interfering RNA (siRNA). Nicotine-induced Src phosphorylation and Id1 expression. Inhibition of Src by siRNA resulted in decreased nicotine-induced Id1 expression. Inhibition of Src and Id1 expression by siRNA in innate or established gemcitabine resistant pancreatic cancer cells resulted in gemcitabine sensitization. To determine if nicotine contributes to gemcitabine chemoresistance, we exposed gemcitabine-sensitive cells to nicotine with subsequent exposure to gemcitabine IC50, 250 ng/ml, and cell viability assays confirmed a 2-fold increase in cell prolilferation and a 4.5-fold reduction in apoptosis. Further, nicotine induced phosphorylation of key signaling enzymes involved in proliferation and apoptosis, Erk1/2 and Akt respectively. Conclusions: In summary, we demonstrate that Id1, through a nicotine-promoting Src-dependent pathway, is necessary for establishment of a chemoresistant phenotype in pancreatic cancer cells. Understanding the signaling pathways involved in pancreatic tumor chemoresistance will lead to therapies resulting in improved tumor responses. No significant financial relationships to disclose.


2021 ◽  
Author(s):  
Yang Liu ◽  
Yongjie Xie ◽  
Jinsheng Ding ◽  
Liangliang Wu

Abstract Purpose: Pancreatic cancer is one of the most malignant cancers with rapid disease progression. Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% in exocrine pancreatic cancer. DDX31 is one of the Asp-Glu-Ala-Asp (DEAD)-box RNA helicases (DDX) family member, which has never been reported in pancreatic ductal adenocarcinoma. Through comprehensive analysis of bioinformatics screening, clinical pathological data and experiment results verification, we found DDX31 may be a promising oncogene.Patients and methods: The potential correlation between DDX3 expression and clinical feature of PDAC was analyzed, which revealed that patients with high DDX31 expression may have a poor prognosis. Elevated expression levels of DDX31 in PDAC compared with adjacent normal tissues were determined by immunohistochemical and Western blot analyses. Western blot analysis of N-cadherin, Snail, transwell, and wound healing assays was carried out to evaluate the pro-metastasis effects of DDX31 in PDAC. In vitro experiments included colony formation assay. Edu labeling assay, CCK-8, western blot analysis of Ki67, PCNA, and an in vivo subcutaneous mouse model were used to analyze the role of DDX31 in PDAC proliferation.Results: In our research, integrated bioinformatics analysis of the TCGA and GEO databases was performed to identify the metastasis and proliferation-related differentially expressed genes (DEG). DDX31 predicts strong metastasis and proliferation capacity of PDAC, was finally screened. Then, the clinical data identified that highexpression-DDX31 was correlated with pancreatic tumor size, pathological grade, and lymph node metastasis. The in vitro and vivo experiments revealed that overexpression-DDX31 promoted the migration, proliferation and cell viability of pancreatic cancer cells, these functions of DDX31 had also been proved in the knockdown results. Moreover, the EMT related markers and proliferation markers were identified to be positively regulated by DDX31 in pancreatic cancer cells.Conclusion: Thus, our work uncovered that DDX31 promotes migration and proliferation in PDAC and might be a promising therapeutic target in pancreatic cancer.


Author(s):  
Amit Khanna ◽  
Kulandaivelu Mahalingam ◽  
Debarshi Chakrabarti ◽  
Giridharan Periyasamy

AbstractGemcitabine, a novel pyrimidine nucleoside analog, has become the standard chemotherapeutic agent for pancreatic cancer patients. The clinical impact of gemcitabine remains modest owing to the high degree of inherent and acquired resistance. There are various lines of evidence that confirm the role of Ets-1, a proto-oncoprotein, in tumor invasion, progression, and chemoresistance. This study examines a hypothesis that implicates Ets-1 in the development of gemcitabine-resistance in pancreatic cancer cells. Ets-1 protein expression was assessed in parental pancreatic cancer cells and their gemcitabine-resistant clones. Western blot analysis revealed elevated levels of Ets-1 protein expression in gemcitabine-resistant PANC1GemRes (4.8-fold increase; P < 0.05), MIA PaCa2GemRes (3.2-fold increase; P < 0.05), and Capan2GemRes (2.1-fold increase; P < 0.05) cells as compared to their parental counterparts. A time course analysis was conducted to determine the change in Ets-1 expression in the parental cells after incubation with gemcitabine. Reverse transcriptase quantitative real-time PCR (RT-qPCR) and Western blot analysis revealed a significant increase in Ets-1 expression. All the three parental cells incubated with gemcitabine showed elevated Ets-1 protein expression at 6 h. By 24 h, the expression level had decreased. Using small interfering RNA (siRNA) against Ets-1 in gemcitabine-resistant cells, we demonstrated a reversal in gemcitabine chemosensitivity and also detected a marked reduction in the expression of the Ets-1 target genes MMP1 and uPA. Our novel finding demonstrates the significance of Ets-1 in the development of gemcitabine chemoresistance in pancreatic cancer cells. Based on these results, a new siRNA-based therapeutic strategy targeting the Ets-1 genes can be designed to overcome chemoresistance.


1999 ◽  
Vol 17 (8) ◽  
pp. 2419-2419 ◽  
Author(s):  
Zhaowen Zhu ◽  
Helmut Friess ◽  
Fabio F. diMola ◽  
Arthur Zimmermann ◽  
Hans U. Graber ◽  
...  

PURPOSE: The reasons for the high frequency of perineural invasion and the presence of pain in pancreatic cancer are still not clear. Nerve growth factor (NGF) and its high-affinity receptor TrkA are involved in stimulating epithelial cancer cell growth and perineural invasion, as well as in pain generation in chronic benign disorders. PATIENTS AND METHODS: NGF and TrkA were examined by Northern blot analysis, in situ hybridization, and immunohistochemistry in 27 normal and 37 pancreatic cancer tissue samples. The molecular findings were correlated with the degree of perineural invasion, pain, and histopathologic tumor characteristics. RESULTS: Northern blot analysis indicated that NGF and TrkA mRNA levels were increased 2.7-fold and 5.6-fold, respectively (P < .05 and P < .05), in pancreatic cancer tissues compared with the normal pancreas tissue. As shown by in situ hybridization and immunohistochemistry, NGF was strongly present in the cytoplasm of pancreatic cancer cells. TrkA was intensely present in the perineurium of pancreatic nerves but not in the cancer cells. There was no difference in NGF and TrkA expression between early (stages I and II) and advanced (stage III) tumor stages and between well-/moderately differentiated (grades 1 and 2) and poorly differentiated (grade 3) tumors. However, tumors with high NGF/TrkA expression levels exhibited more frequent perineural invasion (P < .01). Furthermore, increased NGF/TrkA expression levels were associated with a higher degree of pain (P < .01). CONCLUSION: Enhanced expression of the NGF/TrkA system may influence perineural invasion and may contribute to the pain syndrome in human pancreatic cancer.


Gut ◽  
1998 ◽  
Vol 43 (3) ◽  
pp. 414-421 ◽  
Author(s):  
H Friess ◽  
Z Lu ◽  
H U Graber ◽  
A Zimmermann ◽  
G Adler ◽  
...  

Background—bcl-2and bax belong to thebcl-2-related gene family, which marks a new class of genes that influence apoptosis. Thebcl-2 oncogene acts as a broad antiapoptotic factor and extends both normal and tumour cell survival. In contrast, the bax gene is a promoter of apoptosis.Aims—To analyse the expression of bcl-2 andbax in pancreatic cancer and correlate the results with clinical parameters.Patients—Pancreatic cancer tissue samples were obtained from 28 female and 32 male patients (median age 63, range 43–79 years) having surgery for pancreatic cancer. Normal pancreatic tissues obtained from 18 previously healthy organ donors served as controls.Methods—The levels ofbcl-2 and baxmRNA expression were analysed by northern blot and the exact site of mRNA transcription was determined by in situ hybridisation. The presence of the corresponding proteins was determined by immunohistochemistry.Results—Northern blot analysis indicated that, in comparison with the normal pancreas,bcl-2 mRNA was overexpressed in 30% andbax mRNA in 61% of the pancreatic cancer samples. Concomitant overexpression ofbcl-2 and bax was present in 26% of the cancer samples. Pancreatic adenocarcinomas exhibited 3.7-fold and 5.4-fold increases (p<0.001) inbcl-2 and baxmRNA levels respectively. In situ hybridisation showed that bothbcl-2 and baxmRNA were expressed in the cancer cells. Immunohistochemical analysis showed positive Bcl-2 and Bax immunostaining in 28 and 83% of the cancer samples respectively. In multivariate analysis (Cox regression model), bax expression was found to be a strong indicator of survival (p<0.001). Patients whose tumours exhibited Bax immunostaining lived significantly longer (12 months) than those whose tumours were Bax negative (five months) (p<0.039). In contrast, no relation was found between Bcl-2 and survival time.Conclusions—The data indicate that genes that are involved in the regulation of apoptosis are upregulated in human pancreatic cancer cells. Prolonged survival times in patients in whom apoptosis promoting factors are upregulated indicate that apoptotic pathways are of biological significance in pancreatic cancer.


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