Unraveling the Mechanism of Radiosensitization by Gemcitabine: The Role of TP53

Pauwels, Bea; Korst, A.E.C.; Andriessen, Veronique; Baay, Marc; Pattyn, G; Lambrechts, Hilde; Pooter, Christel M J De; Lardon, Filip; Vermorken, Jan B.

doi:10.1667/rr3445.1

Cited by 29 publications

(22 citation statements)

References 38 publications

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“…Our data also demonstrated that gemcitabine had genotoxic effects regardless of the status of TP53 because the two cell lines evaluated displayed an increased amount of DNA damage after treatment. These findings are in accordance with those obtained in the lung cancer cell line A549, in which a relationship between gemcitabine genotoxicity and TP53 status was not observed (Paulwels et al, 2005). Previously, we reported that the gemcitabine activity on cell cycle arrest was not influenced by TP53 status, although the apoptosis indexes have been different in the RT4 (wild-type TP53) and 5637 (mutated TP53) cell lines (Da Silva et al, 2010).…”

Section: Discussionsupporting

confidence: 91%

No Relationship between the Amount of DNA Damage and the Level of hMLH1 and RASSF1A Gene Expression in Bladder Cancer Cells Treated with Cisplatin and Gemcitabine

Camargo

Silva²,

Gobette³

et al. 2013

Asian Pacific Journal of Cancer Prevention

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Tumor response to antineoplastic drugs is not always predictable. This is also true for bladder carcinoma, a highly recurrent neoplasia. Currently, the combination of cisplatin and gemcitabine is well accepted as a standard protocol for treating bladder carcinoma. However, in some cases, this treatment protocol causes harmful side effects. Therefore, we investigated the roles of the genes TP53, RASSF1A (a tumor suppressor gene) and hMLH1 (a gene involved in the mismatch repair pathway) in cell susceptibility to cisplatin/gemcitabine treatment. Two bladder transitional carcinoma cell (TCC) lines, RT4 (wild-type TP53) and 5637 (mutated TP53), were used in this study. First, we evaluated whether the genotoxic potential of cisplatin/gemcitabine was dependent on TP53 status. Then, we evaluated whether the two antineoplastic drugs modulated RASSF1A and hMLH1 expression in the two cell lines. Increased DNA damage was observed in both cell lines after treatment with cisplatin or gemcitabine and with the two drugs simultaneously, as depicted by the comet assay. A lack of RASSF1A expression and hypermethylation of its promoter were observed before and after treatment in both cell lines. On the other hand, hMLH1 downregulation, unrelated to methylation status, was observed in RT4 cells after treatment with cisplatin or with cisplatin and gemcitabine simultaneously (wild-type TP53); in 5637 cells, hMLH1 was upregulated only after treatment with gemcitabine. In conclusion, the three treatment protocols were genotoxic, independent of TP53 status. However, cisplatin was the most effective, causing the highest level of DNA damage in both wild-type and mutated TP53 cells. Gemcitabine was the least genotoxic agent in both cell lines. Furthermore, no relationship was observed between the amount of DNA damage and the level of hMLH1 and RASSF1A expression. Therefore, other alternative pathways might be involved in cisplatin and gemcitabine genotoxicity in these two bladder cancer cell lines.

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Section: Discussionsupporting

confidence: 91%

No Relationship between the Amount of DNA Damage and the Level of hMLH1 and RASSF1A Gene Expression in Bladder Cancer Cells Treated with Cisplatin and Gemcitabine

Camargo

Silva²,

Gobette³

et al. 2013

Asian Pacific Journal of Cancer Prevention

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“…In RT112 cells, GTC produced a different effect on cell-cycle phase distribution. Cells accumulated at the G 1 /S border suggesting involvement of the replication check-point and resembling the effect of gemcitabine alone in squamous lung cancer cell lines (36). The pattern of cell cycle distribution in GTC-treated RT112 cells may indicate that this line acquired additional genetic lesions in the ATM/Chk2/Cdc25A/Cdk2 pathway leading to the escape from inter-S phase checkpoint control.…”

Section: Discussionmentioning

confidence: 90%

“…To date, eleven ErbB ligands, growth factors containing EGF-like domains, have been characterised. ErbB-2, a preferential partner for all other receptors (16), has INTERNATIONAL JOURNAL OF ONCOLOGY 34: 1155-1163, 2009 Lapatinib, a dual inhibitor of ErbB-1/-2 receptors, enhances effects of combination chemotherapy in bladder cancer cells …”

mentioning

confidence: 99%

Lapatinib, a dual inhibitor of ErbB-1/-2 receptors, enhances effects of combination chemotherapy in bladder cancer cells

et al. 2009

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Abstract. Survival rate of patients diagnosed with the invasive form of bladder cancer is low suggesting an urgent need to implement novel treatments. GTC (gemcitabine, paclitaxel and cisplatin) is a new chemotherapeutic regimen, which has shown promise in clinical trials. Given that receptor tyrosine kinases of the ErbB family are overexpressed in a high proportion of metastatic bladder tumours, approaches involving small-molecule inhibitors of ErbB receptors in combination with conventional cytostatic drugs are of potential interest. Here, we show that the dual inhibitor of ErbB receptors, lapatinib, enhances cytostatic and induces cytotoxic effects of GTC in two bladder cancer cell lines which differ with regard to expression levels of proteins taking part in the ErbB pathway. Lapatinib inhibited phosphorylation of ErbB receptors and also reduced the level of phosphorylated AKT. Flow cytometry analysis demonstrated that GTC treatment affects cell cycle distribution differently in the presence or absence of lapatinib. In RT112 cells, which express high levels of ErbB receptors and harbour wild-type p53, combined GTC/lapatinib treatment resulted in the phosphorylation of p53 at Ser46 and accumulation of sub-G 1 cell populations. Our data indicate that a combinatorial approach involving GTC and lapatinib may have therapeutic potential in a subset of bladder tumours depending on the genetic context. IntroductionBladder cancer is a worldwide disease with poor clinical outcome, especially among patients with the muscle invasive form of the disease (1). Several combinations of chemotherapeutic agents are used in treatment of metastatic transitional cell carcinoma (TCC) of the bladder. The combination of methotrexate, vinblastine, doxorubicin and cisplatin was previously considered the 'gold standard' chemotherapy treatment of TCC, although the median survival was only one year (2). Administration of the gemcitabine and cisplatin regimen has resulted in decreased toxicity, but has not improved survival rates (3). At present, a combination of gemcitabine, paclitaxel (taxol) and cisplatin (GTC) with median survival of 22 months is considered as a promising approach (4). In view of the continuing modest survival rates, novel targeted therapies for the treatment of advanced TCC of the bladder are urgently required. Much interest currently centres on modifying the activity of epidermal growth factor receptor (EGFR) family members (5-7). This family, which has been implicated in human cancers, comprises four receptors, ErbB-1 (HER1, EGFR), ErbB-2 (HER2), ErbB-3 (HER3) and ErbB-4 (HER4) (8). High expression of ErbB-1/ErbB-2, which has been described in TCC of the bladder, is an independent predictor of reduced survival (9-12). In contrast, high expression of ErbB-3/ErbB-4 is associated with favourable clinical outcome in TCC patients (13,14).The ErbB receptors are composed of an extracellular ligand-binding region, transmembrane domain, and a cytoplasmic region containing a tyrosine kinase domain and autophosphorylation sit...

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“…At different time points after radiation, both adherent and detached cells were collected by trypsinisation; 10 6 cells were washed with PBS and resuspended in 100 ml laemmli sample buffer (Bio-Rad, Nazareth, Belgium). Western blotting and immunodetection were performed as described earlier (Pauwels et al, 2005b). Primary antibodies were 1/100 anti-caspase 8 (Ab-3) (Calbiochem, Leuven, Belgium), 1/100 anti-caspase 9 (Ab-2) (Calbiochem), 1/1000 anti-Bid and truncated Bid (tBid) (Bioké, Leiden, The Netherlands).…”

Section: Western Blot and Immunodetectionmentioning

confidence: 99%

The role of apoptotic cell death in the radiosensitising effect of gemcitabine

et al. 2009

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BACKGROUND: The aim of this study was to evaluate the radiosensitising effect of gemcitabine, in terms of cell-cycle progression, induction of apoptosis, and to investigate the molecular events regulating apoptosis. METHODS: Tumour cells were treated with gemcitabine, radiation, or the combination. 0 -72 h after treatment, cells were collected for cell-cycle analysis and apoptosis determination. Caspase 8 and 9, Bid and tBid expression were determined by western blot. The mitochondrial membrane potential was determined using flow cytometry. An RT 2 Profiler PCR Array for human apoptotic genes was performed after the combination or TRAIL treatment. RESULTS: Gemcitabine and radiation resulted in an early S-phase block immediately after treatment, after which the cells moved synchronously through the cell cycle. When cell-cycle distribution returned to pre-treatment levels, an increased induction of apoptosis was observed with activation of caspase 8 and 9 and a reduction of the mitochondrial membrane potential. Gene expression after treatment with radiosensitising conditions was comparable with expression after the TRAIL treatment. CONCLUSION: A role for the cell-cycle perturbations and the induction of apoptosis could be attributed to the radiosensitising effect of gemcitabine. Apoptosis induction was comparable with the apoptotic pathway observed after the TRAIL treatment, that is the involvement of the extrinsic apoptosis pathway.

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Unraveling the Mechanism of Radiosensitization by Gemcitabine: The Role of TP53

Cited by 29 publications

References 38 publications

No Relationship between the Amount of DNA Damage and the Level of hMLH1 and RASSF1A Gene Expression in Bladder Cancer Cells Treated with Cisplatin and Gemcitabine

No Relationship between the Amount of DNA Damage and the Level of hMLH1 and RASSF1A Gene Expression in Bladder Cancer Cells Treated with Cisplatin and Gemcitabine

Lapatinib, a dual inhibitor of ErbB-1/-2 receptors, enhances effects of combination chemotherapy in bladder cancer cells

The role of apoptotic cell death in the radiosensitising effect of gemcitabine

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