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Martin P Barr
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MA 04 - Advocacy: Listen to the Patients (ID 655)
- Event: WCLC 2017
- Type: Mini Oral
- Track: Patient Advocacy
- Presentations: 1
- Moderators:Rudolf M Huber, C.L. Dégi
- Coordinates: 10/16/2017, 11:00 - 12:30, Room 313 + 314
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MA 04.10 - An Assessment of the Willingness to Provide Serial Bio-Specimens: Experience from an Irish Tertiary Cancer Centre (ID 10076)
12:00 - 12:05 | Author(s): Martin P Barr
- Abstract
- Presentation
Background:
The rising imperative to improve our understanding of cancer heterogeneity and individualised drug response has led to a high demand for biopsy material. With improvements in technologies, there is now a move away from more traditional tissue based sampling to liquid based biopsies. ‘Liquid biopsies’ provide a non-invasive means for molecularly profiling patients with cancer, thus benefiting patients and clinicians in terms of treatment choice and shared decision-making. We assessed the willingness of patients to undergo repeated tissue and/or ‘liquid’ based sampling.
Method:
Detailed questionnaires, assessing patients’ perceptions of, and willingness to undergo serial biopsies were distributed to ambulatory patients at a tertiary cancer referral centre (St. James’s Hospital, Dublin). Multivariate analysis was performed using ordinal logistic regression analysis.
Result:
The questionnaire response rate was 97% (247/255). Respondents were primarily female (73%), aged between 51-70 yrs (51%), with breast (39%), colorectal (16%), oesophagogastric (13%), and lung cancer (12%). Of those that responded, repeat biopsy of an easily accessible lesion was acceptable to 203 (82%) patients if recommended by an oncologist. However this reduced to 102 (41%) patients, if the purpose was solely for clinical trial. Acceptability decreased to 168 (68%) and 81 (33%) patients respectively for more invasive biopsies. Additionally, 79 (32%) patients were willing to undergo additional biopsy for research purposes only, with 54 (21%) patients uncertain of its utility in research. Lower performance status (OR=0.44, p=0.04) and the belief that biopsy was unimportant for research (OR=0.74, p=0.04) negatively impacted on willingness to undergo biopsy, while a prior invasive biopsy increased acceptance (OR=1.02, p=0.02). In terms of blood sampling, 82% of patients would consent to repeated blood sampling over the course of their treatment, with >5 samples considered acceptable by 51.5% of patients. Patients with lung cancer had 3.38 greater odds (OR=3.38, p=0.047) of consenting to a repeated blood sample for purely research purposes (compared to any other type of cancer); however their willingness to undergo repeat biopsy was similar to that of other patients (OR=1.99, p=0.129). Data analysis is currently on-going.
Conclusion:
Patients with cancer are willing to participate in serial sampling of blood and urine but are less likely to consent to repeated tissue biopsies. Patients with lung cancer were particularly amenable to repeated blood sampling compared to patients with other cancer types. This is significant given the recent data supporting the use of ‘liquid’ biopsy for real-time monitoring of resistance mutations and treatment response dynamics in patients with lung cancer.
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P1.02 - Biology/Pathology (ID 614)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Biology/Pathology
- Presentations: 3
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.02-011 - XRCC6BP1: A Key Player in the DNA Repair of Cisplatin Resistant NSCLC Cells (ID 10225)
09:30 - 09:30 | Presenting Author(s): Martin P Barr
- Abstract
Background:
Alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating resistance to chemotherapeutic agents.
Method:
DNA Repair Pathway RT[2 ]Profiler Arrays were used to elucidate key DNA repair genes implicated in chemoresistant NSCLC cells using cisplatin resistant (CisR) and corresponding parental (PT) H460 cells previously established in our laboratory. DNA repair genes significantly altered in CisR cells were validated at the mRNA and protein level, using RT-PCR and Western blot analysis, respectively. The translational relevance of differentially expressed genes was examined in a cohort of chemo-naïve matched normal and tumour lung tissues from NSCLC patients. Loss of function studies were carried out using siRNA technology. The effect of XRCC6BP1 gene knockdown on apoptosis was assessed by FACS using Annexin-V/PI staining. Cellular expression and localisation of XRCC6BP1 protein and H2AX foci in response to cisplatin were examined by immunofluorescence using the Cytell Imaging System. To investigate a role for XRCC6BP1 in lung cancer stem cells, Side Population (SP) studies were used to characterise stem-like cells in a panel of chemoresistant cell lines. XRCC6BP1 mRNA analysis was also examined in ALDH1[+] and ALDH1[- ]subpopulations. Immunohistochemistry analysis was carried out on a cohort of resected lung tumour tissues (n=20) and XRCC6BP1 expression was correlated with clinicopathological parameters.
Result:
We identified a number of critical DNA repair genes that were differentially regulated between H460 PT and CisR NSCLC cells, where XRCC6BP1 mRNA and protein expression was significantly increased (mRNA; 19.4-fold) in H460 CisR cells relative to their PT counterparts. Relative to matched normal lung tissues, XRCC6BP1 mRNA was significantly increased in lung adenocarcinoma patients. Gene silencing of XRCC6BP1 induced significant apoptosis of CisR cells and reduced the DNA repair capacity of these cells relative to scrambled (negative) controls. Immunofluorescence studies showed an increase in XRCC6BP1 protein expression and H2AX foci in CisR cells relative to their PT counterparts. While SP analysis revealed a significantly higher stem cell population in CisR cells, XRCC6BP1 mRNA expression was considerably increased in SKMES-1, H460 and H1299 ALDH1[+] CisR cells compared to ALDH1[-] cells. Data analysis of XRCC6BP1 immunohistochemistry is currently ongoing.
Conclusion:
We identified XRCC6BP1 as key DNA repair gene implicated in cisplatin resistant NSCLC. Our data highlight the potential of targeting components of the DNA repair pathway in chemoresistant lung cancer, in particular XRCC6BP1, either alone or in combination with conventional cytotoxic therapies.
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P1.02-071a - Targeting Human Single Stranded DNA Binding Protein (hSSB) 1, a Novel Prognostic Factor, in Non-Small Cell Lung Cancer (ID 9210)
09:30 - 09:30 | Author(s): Martin P Barr
- Abstract
Background:
Lung cancer is the leading cause of cancer death worldwide. The hallmark of all malignant disease is genomic instability leading to tissue invasion, metastasis and resistance to chemotherapy, notably cisplatin. hSSB1 is a guardian of the genome with a key role in the detection and repair of DNA double-strand breaks, replication fork arrest and oxidative stress damage. Recently we have shown that hSSB1 is directly phosphorylated by DNA-PK at serine residue 134 in response to replication stress to promote cellular survival. We hypothesized that hSSB1 may play a role in the pathogenesis of non-small cell lung cancer (NSCLC) and in the mechanism of resistance to cisplatin based chemotherapy observed for (NSCLC). Therefore we evaluated the role of hSSB1 as a prognostic factor and as a potential new target for therapy.
Method:
We analyzed the prognostic significance of hSSB1 mRNA expression from public on line databases and through assessment of protein expression in an NSCLC tissue macro-array (TMA) using immunohistochemistry. hSSB1 mRNA levels were analyzed in matched normal:tumour adenocarcinoma and squamous cell tumour samples, and in a platinum sensitive vs resistant cells. We also explored the impact of hSSB1 expression on NSCLC cell lines sensitivity to cisplatin (measured by cell proliferation) by over-expressing a Flag tagged hSSB1 or depleting hSSB1 with specific small interfering (si)RNA.
Result:
hSSB1 expression was associated with poor prognosis for lung cancer, high levels of mRNA and protein expression correlating with a worse overall survival. hSSB1 mRNA levels were prognostic in adenocarcinomas only. hSSB1 mRNA was also significantly increased in both adenocarcinoma and squamous cell carcinoma compared to matched normal tissue. Furthermore, we observed that hSSB1 was upregulated in H460 cisplatin resistant cells as compared to the parental line. Knockdown of hSSB1 in H460 cells was associated with a significant increase in sensitivity to cisplatin.
Conclusion:
Our results establish hSSB1 as a prognostic factor in non-small cell lung cancer. Moreover, targeting hSSB1 may prove an effective method of reversing platinum resistance. Evaluation of the potential role of DNA-PK inhibition in inhibiting hSSB1 activation and reversing cisplatin and radiotherapy resistance in tumours with high levels of hSSB1 expression is currently ongoing.
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P1.02-071b - SASH1 Is a Prognostic Indicator and Future Target in NSCLC (ID 9591)
09:30 - 09:30 | Author(s): Martin P Barr
- Abstract
Background:
Lung cancer is the most commonly diagnosed cancer in the world and the fifth most common in Australia, where it is responsible for almost one in five cancer deaths. SASH1 (SAM and SH3 domain-containing protein 1) is a tumor suppressor functioning to control of apoptosis and cellular proliferation. Previously SASH1 has been shown to be down-regulated in approximately 90% of lung cancers, however little is known about the role of SASH1 in the pathogenesis of the disease. Cytotoxic platinum based chemotherapy two-drug regimens remain a cornerstone NSCLC patient care, however, resistance to these agents is almost inevitable. The re-sensitisation of these cancer cells to chemotherapeutics is a key to improving patient survival. We hypothesised that modulation of SASH1 expression may alter cisplatin sensitivity.
Method:
A panel of lung cancer cell lines depleted of SASH1 (siRNA) or overexpressing SASH1 were analysed for protein levels via immunoblotting, cell proliferation, and survival/death assays. Treatment of lung cancer cells with the SASH1 protein stabilising compound chloropyramine (0-50 μM) and/or cisplatin (0-10 μM) was performed followed by immunoblotting for SASH1, cell proliferation, and survival/death assays. SASH1 IHC staining of adenocarcinoma and Squamous cell carcinomas was correlated with patient survival.
Result:
We demonstrated that SASH1 depletion results in a significant increase in cellular proliferation of NSCLC cancer cells. The depletion of SASH1 within lung cancer cell lines was associated with a significant increase in cisplatin resistance. Transfection of SASH1 into NSCLC cell lines induced cell death. The treatment of cells with the SASH1 protein stabilising compound chloropyramine increased SASH1 levels, reduced proliferation and induced apoptosis. Furthermore, chloropyramine increased cisplatin sensitivity. The relationship between SASH1 protein expression with overall survival was accessed in a NSCLC TMA panel. This showed that high SASH1 protein levels were associated with a poor prognosis in adenocarcinomas but were non-prognostic in squamous cell disease. Interestingly high SASH1 mRNA levels were associated with a favourable prognosis in adenocarcinoma but were not prognostic in squamous cell cancer. In a panel of cancer cell lines we observed no correlation between mRNA and protein levels that may explain this discrepancy.
Conclusion:
Agents that upregulate SASH1, or SASH1 gene therapy, are potential novel approaches to the management of NSCLC. Further preclinical and clinical studies of chloropyramine in combination with chemotherapy are justified in NSCLC.
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P1.03 - Chemotherapy/Targeted Therapy (ID 689)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Chemotherapy/Targeted Therapy
- Presentations: 4
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.03-039 - Therapeutic Inhibition of the Cancer Stem Cell Marker, ALDH1, a Promising Mechanism by Which Cisplatin Sensitivity Can Be Restored in NSCLC (ID 9909)
09:30 - 09:30 | Presenting Author(s): Martin P Barr
- Abstract
Background:
Cisplatin remains the cornerstone of current chemotherapeutic combination startegies in the treatment of NSCLC. Despite initial cisplatin sensitivity tumours develop resistance, which in turn undermines the efficacy of cisplatin as a therapuetic agent. Numerous mechanisms, signalling pathways and theories have been suggested and elucidated in terms of cisplatin resistance and in the development of it, however, to date the clinical issue of resistance has not been overcome. A current avenue of interest is the cancer stem cell (CSC) hypothesis, in which the survival and expansion of highly resistant CSCs during chemotherapeutic treatment are thought to be a contributing factor of resistance and recurrence. Specific inhibition of key CSC markers in combination with chemotherapy may undermine the inherent resistance of the CSC population and sensitise these cells to the cytotoxic effects of therapy. One such CSC marker observed across numerous tumours is aldehyde dehydrogenase 1 (ALDH1), our hypothesis suggests that inhibition of the ALDH1-positive CSC population within cisplatin resistant NSCLC will resensitise the cellls to the cytotoxic effects of cisplatin.
Method:
Using an isogenic panel of matched parent (PT) and cisplatin resistant (CisR) NSCLC cell lines ALDH1 was identified as a CSC marker present within the CisR sublines of each NSCLC histology and characterised as CSCs. ALDH1 was inhibited using two pharmacological ALDH1 inhibitors, diethlylaminobenzaldehyde (DEAB) and disulfiram (commercially known as Antabuse used in the treatment of alcoholism). ALDH1 inhibition was confirmed by flow cytometry. PT and CisR cell lines were treated with inhibitor alone and in combination with cisplatin and assessed in terms of proliferation, clonogenic survival and apoptosis relative to cisplatin-only treatment.
Result:
Both DEAB and the FDA-approved disulfiram significantly decreased the presence of the ALDH1-positive CSC subpopulation across all CisR cell lines. DEAB and disulfiram in combination with cisplatin induced a significant decrease in proliferation and clonogenic survival as well as significant increases in cisplatin-induced apoptosis across CisR sublines when compared to cisplatin alone.
Conclusion:
DEAB and disulfiram significantly reduced the presence of the highly resistant ALDH1-positive CSC subpopulation. This pharmacological CSC depletion in conjunction with cisplatin was associated with the resensitisation of cisplatin resistant cells to the cytotoxic effects of cisplatin, thus restoring cytotoxic efficacy. The resensitisation effect of the disulfiram-based combination strategy, as well as its FDA-approval and extentsive safety profile highlights this strategy as one of great promise. In summary, these data suggest a role for ALDH1 inhibition in the resensitisation and possible circumvention of cisplatin resistance.
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P1.03-041 - Exploitation of the Cancer Stem Cell Marker ALDH1 Within the Vitamin a/Retinoic Acid Axis Promotes Re-Sensitisation of Cisplatin Resistant NSCLC (ID 9938)
09:30 - 09:30 | Presenting Author(s): Martin P Barr
- Abstract
Background:
Despite significant advances in personalised medicine in recent decades, cisplatin remains the mainstay chemotherapy in the treatment of NSCLC. The major clinical challenge facing NSCLC today is the development of pan-resistance to platinum agents. Novel drug design, preclinical and clinical trials working toward the approval of new drugs is a lengthy and costly process and in the interim of the drug indentifcation and commercialisation research has turned its focus to two avenues of interest; overcoming cisplatin resistance and the repurposing of approved therapeutics with new indications. Cancer stem cells (CSCs) have been hypothesised to be the initiating cells of therapeutic resistance and tumour recurrence. An ALDH1-positive cell subset has been identified as a key CSC subpopulation present within cisplatin resistant NSCLC sublines. ALDH1 is involved in the metabolism of retinol (vitamin A) and the catalytic conversion of retinal to retinoic acid, where retinoic acid induces cell differentiation. All-trans retinoic acid (ATRA) is a well-established chemotherapeutic agent in the treatment of acute promyelocytic leukaemia; it induces the terminal differentiation of immature cells. We hypothesise that treatment of the cisplatin resistant NSCLC sublines with retinol or ATRA will deplete the ALDH1-positive population and subsequently increase or restore cisplatin sensitivity.
Method:
Flow cytometry on a panel of matched parent (PT) and cisplatin resistant (CisR) NSCLC cell lines revealed the greater presence of ALDH1-positive CSC subpopulations within the CisR sublines of each NSCLC histology relative to PT lines. Cells were treated with retinol (substrate of the retinoic acid pathway) or ATRA (product of the retinoic acid pathway) and the presence of the ALDH1-positive CSC subset reanalysed by flow cytometry. Following treatment of the PT and CisR cells with retinol or ATRA alone and in combination with cisplatin the functional parameters of proliferation, clonogenic survival and apoptosis were reassessed relative to cisplatin alone.
Result:
Treatment of the CisR sublines with retinol (1μM) or ATRA (5μM) significantly reduced the presence of the ALDH1-positive CSC subset across CisR sublines. Both retinol and ATRA when used in combination with cisplatin significantly reduced the proliferative and survival capacity of each CisR subline while significantly increasing apoptotic cell death compared to cisplatin alone.
Conclusion:
Exploitation of the vitamin A/retinoic acid pathway in combination with cisplatin re-sensitised resistant cells to the cytotoxic effects of cisplatin. These data suggest vitamin A supplementation or the addition of FDA-approved ATRA to the cisplatin-based chemotherapeutic regimen may be of clinical benefit in overcoming tumour recurrence and cisplatin resistance.
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P1.03-042 - BBI608, a Small Molecule Stemness Inhibitor, Circumvents Cisplatin Resistance in NSCLC (ID 9947)
09:30 - 09:30 | Presenting Author(s): Martin P Barr
- Abstract
Background:
The cancer stem cell (CSC) hypothesis is now a well-established and widely investigated field within oncology. It hypothesises that there is a robustly resistant stem-like population of cells that survive and thrive initial chemotherapeutic treatment. These surviving CSCs contribute to the recapitulation of a heterogeneous tumour via a combination of asymmetric and symmetric cell division, subsequently resulting in relapse and therapeutic resistance. BBI608 is a small molecule inhibitor of cancer stemness; it targets STAT3, leading to the inhibition of critical genes required for the maintenance of cancer stemness. Following initial in vitro and in vivo preclinical promise of BBI608 reported in the literature, phase II and III clinical trials are underway and are at various stages of recruitment, progress and completion to investigate BBI608 across a number of advanced malignancies and in combination with numerous chemotherapeutic agents.
Method:
Aldefluor (Stemcell Technologies) staining and flow cytometry analysis of a panel of matched parent (PT) and cisplatin resistant (CisR) NSCLC cell lines identified the ALDH1-positive (ALDH1+ve) subpopulation of cells as an omnipresent CSC subset across cisplatin resistant NSCLC sublines. PT and CisR cell lines were treated with BBI608 (1μM) and the presence of the ALDH1+ve CSC population was reassessed by flow cytometry and expression of stemness factors (Nanog, Oct-4, Sox-2, Klf4 and cMyc) were examined by reverse transcriptase PCR. The functional parameters of proliferation, clonogenic survival and apoptosis were investigated with increasing concentrations of cisplatin in the presence and absence of 1μM BBI608.
Result:
The NSCLC CisR sublines showed a significantly greater ALDH1+ve CSC population relative to their PT counterparts. Treatment of the CisR sublines with 1μM BBI608 significantly depleted the ALDH1+ve CSC population and decreased gene expression of stemness markers. BBI608 significantly decreased the proliferative capacity and clonogenic survival of the CisR sublines when in combination with cisplatin relative to cisplatin alone. Cisplatin in combination with BBI608 significantly increased cisplatin-induced apoptosis in the CisR sublines indicating restoration of cisplatin sensitivity.
Conclusion:
To date, BBI608 has not been investigated in terms of a cisplatin resistant ALDH1+ve CSC population in lung cancer. BBI608, via the inhibition of STAT3, pharmacologically depleted the CSC subpopulation and stemness expression while simultaneously restoring cisplatin sensitivity. There are currently a number of clinical trials in various stages of completion to further investigate BBI608. These data suggest a promising role for BBI608 in the treatment of non-responsive or recurrent NSCLC.
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P1.03-048 - miR-34a and the Micromanagement of Cancer Stemness and Resistance in NSCLC. Does It Hold Therapeutic Benefit? (ID 9968)
09:30 - 09:30 | Presenting Author(s): Martin P Barr
- Abstract
Background:
The capacity of microRNAs to post-transcriptionally regulate a myriad of genes has extended their remit into the realm of stemness and furthermore cancer stemness regulation. Disruption of Dicer-1, a crucial component of microRNA biogenesis, has been shown to completely deplete the stem cell pool in early development, indicating a potential role for microRNAs in the maintenance of stem cells. Such logic has led microRNAs to be investigated in the context of cancer stem cells (CSCs). Studies have revealed that microRNAs play a role in CSC self-renewal, differentiation, drug resistance and metastasis. With this, our hypothesis suggests that microRNAs associated with cisplatin resistance and CSC maintenance may be a key target by which the CSC root of cisplatin resistance could be overcome.
Method:
MicroRNA expression within a panel of age-matched parent (PT) and cisplatin resistant (CisR) NSCLC sublines was profiled using the 7[th] generation miRCURY LNA arrays (Exiqon) and validated by qPCR. Cell lines were stained for the presence of the CSC marker, aldehyde dehydrogenase 1 (ALDH1) and FACS was used to isolate the ALDH1-positive CSC population from the ALDH1-negative bulk cell population. Expression of the panel of cisplatin resistance-associated microRNAs was investigated within the ALDH1-positive CSC population relative to their negative counterparts by qPCR. Significantly altered miRNAs were inhibited in the CisR subline using antagomirs (Exiqon) and the presence of the ALDH1-positive subset reassessed by flow cytometry and expression of stemness genes (Nanog, Oct-4, Sox-2, Klf4, cMyc) determined. The presence of the cisplatin-associated miRNAs was investigated in FFPE murine tumours within a xenograft model of CSCs, in which 1x10[3] ALDH1-positive and negative subsets were injected into NOD/SCID mice.
Result:
Upon validation, a 5-miR signature was identified across NSCLC histologies to be associated with cisplatin resistance. When this panel was further investigated within the ALDH1-positive CSC subpopulation, it was observed that there was a significant up-regulation of miR-34a-5p relative to corresponding ALDH1-negative populations. Interestingly, the ALDH1-positive subpopulations showed significantly greater miR-34a-5p expression when compared to the CisR sublines from which they were isolated. This up-regulation was also observed within the FFPE xenograft tumours. However, inhibition of miR-34a-5p with antagomiRs did not significantly alter the presence of the ALDH1-positive CSC population, or the expression of stemness-associated genes.
Conclusion:
These data suggest that miR-34a-5p while significantly up-regulated in cisplatin resistance and CSCs may not play a functional role in CSC maintenance and further investigation is required to fully elucidate the role of miR-34a-5p in cancer stemness.
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P1.09 - Mesothelioma (ID 695)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Mesothelioma
- Presentations: 1
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.09-007 - Targeting MET/TAM Receptors in Mesothelioma: Are Multi-TKIs Superior to Specific TKI? (ID 9959)
09:30 - 09:30 | Author(s): Martin P Barr
- Abstract
Background:
Malignant pleural mesothelioma (MPM) is an aggressive inflammatory cancer associated with exposure to asbestos, and most patients die within 24 months of diagnosis. There is an urgent need to identify new therapies for treating MPM patients. Targeting “addicted” receptor tyrosine kinase (RTK) signalling networks has become a critical therapy option in cancer therapy. RTK hetero-dimerization may however, be a key element in the development of resistance to such therapy. As such Tyrosine kinase inhibitors (TKIs) with the ability to target multiple receptors may have superior efficacy to those targeting individual receptors. We and others have identified c-MET, MST1R (also known as RON), Axl and Tyro3 as RTKs frequently overexpressed and activated in MPM, making these attractive candidate targets. Several agents have been developed which target these. LCRF0004 specifically targets MST1R, whereas BMS-777607, RXDX-106 or Merestinib (LY2801653) are orally bioavailable small molecule inhibitors which inhibit c-MET, MST1R, Axl and Tyro3 at nM concentrations. These drugs may therefore have clinical utility in the treatment/management of MPM.
Method:
Expression of RON/MET/TAM and associated ligands were assessed in a cohort of patient samples and MPM cell lines comprising benign, epithelial, biphasic, and sarcomatoid histologies. In vitro and in vivo experiments were undertaken to determine the efficacy of single and multi RTK targeting agents (LCRF0004, RXDX-106, BMS-777607). The effects of LCRF0004 and BMS-777607 were subsequently examined in an in vivo SQ xenograft tumour model.
Result:
mRNA expression of the RON/MET/TAM family and associated ligands (MSP, GAS6) was detected in a large panel of normal pleural and MPM cell lines. In a cohort of patient samples, mRNA levels of c-MET, Axl, Tyro3 and various isoforms of MST1R (flRON, sfRON, t-ΔRON) and MSP but not Gas6 or MERTK were increased in tumours compared with benign pleural samples (p<0.05). No MET Exon 14 skipping mutations were detected. RTK targeting agents displayed in vitro efficacy in terms of reduced proliferation. In vivo, the multi-target TKI (BMS-777607) demonstrated superior anti-tumour activity compared with LCRF0004 (MST1R specific compound). IHC analysis of the xenograft tumours showed high cytoplasmic expression of Vimentin, Cytokeratin and Calretinin, with significant necrosis in many.
Conclusion:
Our data suggests that a multi-TKI, targeting the RON/MET/TAM signalling network, is superior to selective RTK inhibition as an interventional strategy in MPM.
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P2.02 - Biology/Pathology (ID 616)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Biology/Pathology
- Presentations: 3
- Moderators:
- Coordinates: 10/17/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P2.02-048 - Survival Correlation Between TP53 Gene and PD-L1 Tumour Expression in Resected Non-Small Cell Lung Carcinoma (ID 10272)
09:30 - 09:30 | Author(s): Martin P Barr
- Abstract
Background:
Tumour suppressor gene TP53 mutation is common in human cancers, especially playing an important role in lung cancer tumourgenesis. Some clinical studies have shown that TP53 alterations in non-small cell lung carcinoma (NSCLC) carry a worse prognosis and may relatively more resistant to chemotherapy and radiation. We conducted this study to evaluate the impact of TP53 assessed by limited targeted profiling, correlating with PD-L1 tumour expression and clinicopathological variables in resected NSCLC.
Method:
NSCLC patients who underwent curative resection between 1998 and 2006 at our institution were included. PD-L1 status was assessed using Ventana SP142 antibody on archival FFPE surgical tumour specimens, arrayed on tissue microarrays (TMAs) with triplicate 0.6 mm cores. PD-L1 was scored as positive if membranous staining was present in >1% of tumour cells aggregated across the replicate cores to address heterogeneity. In collaboration with the Lung Cancer Genomics Ireland Study, a targeted panel of 49 genes was assessed by Sequenom MassArray including TP53 and genes in MAPK and PI3K pathways. Clinicopathological data was obtained from hospital electronic database.
Result:
Seventy-two patients were included, of which 40 (58.0%) were males, with a median age of 66.0 years (range: 51.0 – 82.6). 54.2%, n=39 with adenocarcinoma histological subtypes, 45.8%, n=33 were ex-smoker and 42.9%, n=30 had Stage IB disease. Most patients had T2 stage (71.4%, n=50), N0 nodal disease (55.2%, n=37) and grade 2 differentiation (65.7%, n=46). Presence of TP53 mutation was identified in 22 patients (30.5%). Five patients had co-presence of TP53 mutation and PD-L1 positivity. There was no correlation between PD-L1 positivity with TP53 status, KRAS, PTPN11, PHLPP2, PIK3CA, MET and PIK3R1. The median disease-free survival in TP53 mutation with PD-L1 positivity was not reached. In univariate/unadjusted analysis, co-presence of TP53 mutation and PD-L1 positivity appear to have superior disease-free survival over TP53 wild-type and PD-L1 negativity, HR 0.17 (95%CI 0.01-0.78, p=0.018). A trend was seen with overall survival but not statistically significant (TP53 mutant, PD-L1 positive vs TP53 wild-type, PD-L1 negative: NR vs 23.1 months, HR 0.34 (95% CI: 0.0.5-1.11, p=0.079). Independent PD-L1 positivity appears to be associated with better prognosis: DFS HR 0.36 (95% CI 0.11-0.90, p=0.0272) and OS HR 0.47 (95% CI 0.19-0.98, p=0.0427).
Conclusion:
In our cohort, co-presence of TP53 mutation and PD-L1 expression was not associated with poorer survival among resected NSCLC patients. Independently, PD-L1 expression was associated with better survival, a finding which warrants further investigations as potential biomarker.
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P2.02-064 - A Novel 5-miR Signature Shows Potential as a Diagnostic Tool and as a Predictive Biomarker of Cisplatin Response in NSCLC (ID 9957)
09:30 - 09:30 | Presenting Author(s): Martin P Barr
- Abstract
Background:
MicroRNAs are a class of small non-coding RNAs that range in size from 19-25 nucleotides. They have been shown to regulate a number of processes within tumour biology, including metastasis, invasion and angiogenesis. More recently, miRNAs have been linked to chemoresistance in solid tumours, including lung cancer. Their role in cisplatin resistance has yet to be determined.
Method:
MicroRNA expression within a panel of age-matched parent (PT) and cisplatin resistant (CisR) NSCLC cell lines was profiled using the 7[th] generation miRCURY LNA arrays (Exiqon) and subsequently validated by qPCR. Significantly altered miRNAs within the CisR sublines were manipulated using antagomirs (Exiqon) and Pre-miRs (Ambion) and functional studies were carried out in the presence and absence of cisplatin. To examine the translational relevance of these miRNAs, their expression was examined in a cohort of chemo-naïve patient-matched normal and lung tumour tissue and serum from NSCLC patients of different histologies. A xenograft model of cisplatin resistance was carried out in which 1x10[3] H460 PT or CisR cells were injected into 5-7week old NOD/SCID mice. Tumour volume was measured over time and harvested once the tumour mass measured 500mm[3] and formalin-fixed and paraffin embedded (FFPE). Expression of the 5-miR signature was analysed within FFPE murine tumours and compared between PT and CisR tumours.
Result:
Profiling and subsequent validation revealed a 5-miR signature associated with our model of cisplatin resistance (miR-30a-3p, miR-30b-5p, miR-30c-5p, miR-34a-5p, miR-4286). Inhibition of the miR-30 family and miR-34a-5p reduced clonogenic survival of CisR cells when treated cisplatin. Expression of the miRNA signature was significantly altered in both adenocarcinoma (AD) and squamous cell carcinoma (SCC) relative to matched normal lung tissue and between SCC and AD tissue. miR-4286 was significantly up-regulated in SCC sera compared to normal control and AD sera. Similarly to the cell line expression of the miRNAs, the miR-30 family members and miR-34a-5p were up-regulated in the CisR xenograft FFPE tissue relative to PT.
Conclusion:
A novel miRNA signature associated with cisplatin resistance was identified in vitro, genetic manipulation of which altered clonogenic response to cisplatin. The 5-miR signature showed both diagnostic and prognostic biomarker potential across a number of diagnostically relevant biological media.
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P2.02-069 - Targeting Neuropilin-1 in NSCLC (ID 10205)
09:30 - 09:30 | Presenting Author(s): Martin P Barr
- Abstract
Background:
Neuropilin-1 (NP1) is expressed by a wide variety of human tumour cell lines and diverse human neoplasms, and is implicated in mediating the effects of VEGF on the proliferation, survival and migration of cancer cells. It is extensively expressed in tumour vasculature, where NP1 over-expression is associated with tumour progression and poor clinical outcome. In this study, we examined the effects of targeting NP1 in NSCLC both in vitro and in vivo.
Method:
A panel of NSCLC cell lines (H460, H647, A549 and SKMES) were screened for NP1 at the mRNA and protein levels by RT-PCR and Western blotting, respectively. Cellular expression and localisation of NP1 was further examined by immunocytochemistry, while a panel of retrospective resected lung tumours and matched normal tissues were stained by immunohistochemistry. The effects of targeting NP1 on cell proliferation (BrdU ELISA), apoptosis (FACS, HCS) and downstream survival signalling pathways (Western Blot) were examined under normoxic and hypoxic (0.1% O~2~) cell growth using anti-NP1 neutralising antibodies. Cell survival was assessed in response to treatment of NSCLC cells with a range of chemotherapeutic agents in combination with NP1 neutralising antibodies. Using a human xenograft model, tumour growth studies were carried out in nude mice following subcutaneous injection of NP1 over-expressing cells relative to empty vector controls.
Result:
All lung cancer cell lines examined expressed NP1 with the exception of the H460 cell line. Immunocytochemistry analysis confirmed cellular expression and localisation of this receptor, particularly in the leading edges of migrating cells, suggesting a possible role in cell migration. In a small cohort of resected NSCLC patients, tumour expression of NP1 was high relative to their matched normal lung tissues in adenocarcinoma, squamous cell and large cell neuroendocrine carcinomas. Cell proliferation and apoptosis were significantly altered in NSCLC cells expressing NP1. While hypoxia induced the expression of NP1, treatment of cells with NP1 neutralising antibodies reduced hypoxia-mediated cell proliferation and decreased expression of PI3K and MAPK signalling pathways. In a preliminary study, treatment with NP1 neutralising antibodies sensitised NSCLC cells to the cytotoxic effects of chemotherapy. In vivo, H460 cells over-expressing NP1 significantly increased tumour growth in NOD/SCID mice relative to empty vector controls.
Conclusion:
These data suggest a role for the Neuropilin-1 receptor in promoting cell survival and tumour growth in NSCLC and may offer potential as a therapeutic biological strategy in lung cancer.
