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W. Jungraithmayr



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    P1.02 - Biology/Pathology (ID 614)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P1.02-015 - Comparison of Study Models of Lung Cancer   (ID 9318)

      09:30 - 16:00  |  Author(s): W. Jungraithmayr

      • Abstract

      Background:
      Lung cancer is the most prominent cancer in human with high mortality rate. Although chemo-radiation therapies have been improved, the patient survival is still poor. Thus, not only developing therapeutic medications, but also biomarkers of early diagnosis have been desired. Several models of primary lung cancer research are in use, however, systematic evaluation and characterization of models are required to have suitability and relevance based on study aims. To provide research environment for lung cancer, we reappraise relevant models for lung cancer.

      Method:
      Three concepts of primary lung cancer models were evaluated: (I) Urethane induced lung tumor. (II) Cell line induced tumor model via intravenous (iv) or subcutaneous (sc) injection. (III) ex vivo 3D primary cell culture model. 20 weeks after urethane injection, the animals were harvested to analyze tumor incidence and tumor immunity. Lewis Lung Carcinoma (LLC) cell line was employed for the orthotopic development of lung tumor in 2 weeks after the injection. Hanging drop method was used for the 3D culture of primary cells from LLC sc induced tumor. Immunohistochemistry (IHC) of proliferation markers (pH3 and Ki67), tumor immunity (CD4, CD8, B220, F4/80, NKp46, and PDL-1) were performed for a finer characterization of tumors.

      Result:
      Urethane and iv injection of LLC cell line developed heterogeneously distributed tumors in lung. sc injection stably developed single tumor nodule. 3D cultured primary cells formed spheroids within 5 days. IHC revealed that all tumors were consistently proliferating with less extend in urethane and 3D model. F4/80[+ ]cells and CD4[+] cells infiltrated into tumors significantly more than CD8[+], B220[+], or NKp46[+] cells. T cell populations (CD4[+] and CD8[+]) were much more prominent in LLC iv model than other models. Interestingly the expression of PDL-1 was found only in 3D model.

      Conclusion:
      The urethane-induced primary lung tumor is reliable with a high rate of development, but needs longer time period to develop tumor compared to iv and sc models. iv injection model develops lung tumor in the original location. With relatively more convenience, sc model allows the analysis of tumor without adjacent tissue bias. 3D primary cell culture model enable for conferring characterization of individual tumor and strategic design of therapy, namely personalized medicine. The involvement and characteristics of immune cells found within tumors were comparable across all models. Injections by i.v. or s.c. of cell line to mouse can be considered as an alternative yet convenient model to develop various different types of lung cancers.

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    P1.17 - Thymic Malignancies/Esophageal Cancer/Other Thoracic Malignancies (ID 703)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Thymic Malignancies/Esophageal Cancer/Other Thoracic Malignancies
    • Presentations: 1
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      P1.17-016 - Immunohistochemical Markers as Prognostic Factors in Malignant Thymic Epithelial Tumors (ID 10338)

      09:30 - 16:00  |  Author(s): W. Jungraithmayr

      • Abstract

      Background:
      Thymic epithelial tumors (TET) are rare neoplasms with inconsistent treatment strategies. When researching for molecular pathways to find new therapies, the correlation between specific molecular markers and outcome has been rarely investigated. The aim of this study was to investigate the correlation between survival, metastatic potential and invasiveness of aggressive subtypes of TET and immunohistochemical markers.

      Method:
      We performed retrospective analysis on patients with WHO type B2/B3 mixed type thymoma (MT), thymoma type B3 (B3) and thymic carcinoma (TC) who underwent surgery from 1998 to 2013. Overall survival (OS), disease-free survival (DFS), progression-free survival (PFS) and metastasis-free survival (MFS) were examined. Tumor specimens were stained using a tissue microarray (TMA) (CD117, CD5, p63, p40, p21, p27, p53, Bcl-2, Ki67, podoplanin, synaptophysin, PTEN and Pax8). Invasive behavior of primary tumors and the presence of extrathoracic metastases were assessed.

      Result:
      In 23 patients included into this study (four MT, ten B3, nine TC), we found (I) p21 expression in the cytoplasm significantly correlated with a decrease of OS (P=0.016), PFS (P=0.034) and MFS (P=0.005); (II) MFS was significantly shorter when the combination of p21-low p27-low p53-high was present (P=0.029); and (III) nuclear p27 (P=0.042), Ki-67 (P=0.024) and podoplanin (P=0.05) expression correlated with the presence of extrathoracic metastases.

      Conclusion:
      The main finding of this study is that cytoplasmic p21 expression negatively influences the outcome of malignant TETs and correlates with metastatic activity. Additionally, selected immunohistochemical markers correlate with the distant metastatic potential of TETs. These results may contribute to the stratification of diagnosis and improvement of treatment strategies for thymic malignancies. ​

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    P2.02 - Biology/Pathology (ID 616)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P2.02-036 - The Expression Pattern of CD26/DPP4 in Human Lung Cancer (ID 9319)

      09:30 - 16:00  |  Author(s): W. Jungraithmayr

      • Abstract

      Background:
      Lung cancer is the leading cause of death among cancers. Despite improved surgical and novel radiation improvements, the overall prognosis remains poor. CD26/dipeptidyl peptidase 4 (DPP4) is a ubiquitously expressed transmembrane exopeptidase on the cell surfaces of many different cells including malignancies of breast, colon, and mesothelioma. Phase I data in mesothelioma with a specific antibody showed tolerability in mesothelioma patients.Our group found previously that the activity of CD26/DPP4 of lung adenocarcinoma (Adeno-CA) patients is four times higher than in normal tissue and the inhibition of CD26/DPP4 decreased the growth of lung tumors in experimental models. These data prompted us to analyze the expression of CD26/DPP4 in samples from lung cancer patients to unravel the role of CD26/DPP4 as a biomarker for lung cancer and a target for inhibition to reduce lung cancer burden. burden.

      Method:
      To identify CD26/DPP4 by immunohistochemistry (IHC), we tested four antibodies from Abcam, R/D systems, and Cell signaling technology on multi-organ tissue micro array (TMA) and human lung Adeno-CA cell lines (A549, H460, Gon8, Mai9) derived from advanced stage (IV) of human Adeno-CA. We selected the antibody from Cell signaling technology against CD26/DPP4. For the analysis of CD26/DPP4 by IHC in lung cancer samples, TMAs constructed from non-small cell lung cancer patients were used. The cohort consisted of 475 patients (Adeno-CA: 223; Squamous carcinoma: 252). The intensity of the staining was scored from 0 to 3 in a blinded manner. To quantify CD26/DPP4 in the supernatant of human lung Adeno-CA cell lines in vitro, ELISA was performed.

      Result:
      IHC scores revealed that Adeno-CA expresses significantly more CD26/DPP4 compared to squamous carcinoma (p<0.0001). Consistent with our previous findings, early stage cancer (IA) scores significantly higher than other stages IIB (p=0.0012), IIIA (p=0.0019), and IV (p=0.02) among Adeno-CA samples. We could not find CD26/DPP4 expression on human Adeno-CA cell lines by IHC, but the secretion of the protein in supernatant stays high (A549: 20pg/ml; H460: 161pg/ml; Gon8: 74pg/ml; Mai9: 648pg/ml).

      Conclusion:
      CD26/DPP4 expression was significantly higher at early stages of Adeno-CA samples when compared to advanced stages, supporting our previous findings. From the human cell line data, we suggest that advanced cancer secretes CD26/DPP4 more actively than early stage cancers. CD26/DPP4 seems to be a substantial target for inhibition of human Adeno-CA.