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S. Vicent
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P1.02 - Biology/Pathology (ID 614)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Biology/Pathology
- Presentations: 1
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.02-039 - Preventive and Therapeutic Action of Id1 Inhibition in KRAS-Mutant (KM) Lung Adenocarcinoma (LAC) Tumors in a Xenograft Murine Model (ID 9574)
09:30 - 16:00 | Author(s): S. Vicent
- Abstract
Background:
Id1 has been shown to be involved in cell viability and migration of lung cancer cell lines and confer poor prognosis in LAC-patients. The most frequently mutation in LAC is KRAS, but no targeted therapy has been successfully developed. Here we study the role of Id1 in a KM-LAC murine model.
Method:
The expression of Id1 was analyzed in a panel of human LAC cell lines by qPCR and Western-Blot. Several human cell lines with known mutations (H1792-604, H2009, H358, H1568, H1437, H1703, H2126) were selected to deplete Id1 expression by inducible short hairpin RNA (shRNA) regulated by doxycycline. Proliferation, cell cycle and apoptosis assays were performed to study the cellular mechanism underlying the effect of Id1 deficiency. Mouse xenograft models were generated by subcutaneous injection of KM-LAC cells (H1792-604 and H2009), both shId1 and shGFP cells, in flanks of immunodeficient mice treated with doxycycline (drinking water) from the time of inoculation or once the tumors were established.
Result:
Id1 overexpression was observed in 11 out of 12 cell lines as occurs in previously reported clinical data. Id1 inhibition was achieved in all cell lines compared to controls. In absence of Id1, proliferation assays showed a significant impairment of cell growth in KM-LAC cell lines [H1792-604 31.61% ± 3.96 (P < 0.001); H2009 52.73% ±4.74 (P < 0.001); H358 70.85% ± 8.01 (P < 0.001)]. In KM cells, a significant arrest in G2/M phase of cell cycle was observed when Id1 was inhibited whereas no significant changes were observed in wild type(WT) KRAS cells [KM 1.86 ± 0.28;WT 1.02 ± 0.05 (P < 0.001)]. KM-cells showed a significant apoptosis increase compared to WT-cells [KM-cells 1.66 ± 0.41;WT-cells 0.99 ± 0.13 (P = 0.001)]. In vivo, we observed a significant decrease in tumor volume in mice injected with H1792-604-shId1 cells (60% ± 32.39) compared to shGFP group (356.29% ± 115.32)(P < 0.001). Moreover, mice injected with H2009-shId1 cells did not develop tumors compared to control mice (168.35 ± 68.71)(P < 0.001). Activation of shId1 in established tumors induced a significant reduction of tumor volume in both xenograft models. The inhibition led to regression of 4 out of 10 tumors H1792-604 and all tumors in H2009 inoculated mice.
Conclusion:
These findings support a crucial role of Id1 in tumor development in KRAS-driven adenocarcinoma of the lung. Id1 targeting was proven effective in both, tumor prevention and treatment in our humanized murine model of KM LAC.
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P3.07 - Immunology and Immunotherapy (ID 723)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Immunology and Immunotherapy
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.07-007 - Blockade of the Complement C5a/C5aR1 Axis Impairs Lung Cancer Bone Metastasis (ID 8958)
09:30 - 16:00 | Author(s): S. Vicent
- Abstract
Background:
The complement system, a central part of innate immunity, is implicated in the maintenance of a favorable microenvironment for lung cancer progression. In particular, several studies have demonstrated a tumor-promoting role for the immune regulator C5a, but its direct impact on growth and dissemination of lung cancer cells is poorly understood. In this study we aimed to investigate the contribution of the C5a/C5aR1(CD88) axis to the malignant phenotype of NSCLC cells, particularly to skeletal colonization, a preferential lung metastasis site.
Method:
The association between C5aR1 expression and clinical outcome was assessed at both the mRNA and protein levels by in silico and immunohistochemistry analyses, respectively. The mRNA levels of C5aR1 were also determined in a panel of 45 cell lines representing the main lung cancer subtypes. The expression of the receptor was validated by flow cytometry. The functional significance of C5aR1 expression in NSCLC cells was evaluated using lentiviral gene silencing and drug inhibition in in vivo models of lung cancer bone metastasis. In vitro functional assays for signaling, migration, invasion, metalloprotease activity and osteoclastogenesis were also performed.
Result:
High levels of C5aR1 in primary human NSCLC tumors were significantly associated with shorter recurrence-free survival and overall survival both at the mRNA and protein levels. Many lung cancer cell lines expressed C5aR1 mRNA. C5aR1 was also detected by flow cytometry on the cell surface of representative lung cancer cell lines. Moreover, addition of C5a to cultured cells led to phosphorylation of p42/44 MAPK and translocation of NF-kB to the nucleus, demonstrating the functionality of the receptor. Silencing of C5aR1 in A549 and H460 lung cancer cells did not affect proliferation, but led to a substantial reduction in skeletal metastatic burden and osteolysis in in vivo models. C5aR1 pharmacological blockade also reduced the osseous metastatic activity of lung cancer cells in vivo. Moreover, metalloproteolytic, migratory and invasive tumor cell activities were modulated in vitro by C5aR1 stimulation or gene silencing. This effect was associated with decreased osteoclastogenic activity in vitro, which was rescued by exogenous addition of the chemokine CXCL16.
Conclusion:
Disruption of C5aR1 signaling in lung cancer cells abrogates osseous colonization through a CXCL16-mediated mechanism. This study reinforces the role played by the C5a/C5aR1 axis in lung cancer progression, and supports its potential use as a novel therapeutic target.
