Daniela Bianconi

Integrins in the Spotlight of Cancer

Integrins are heterodimeric cell surface receptors that bind to different extracellular ligands depending on their composition and regulate all processes which enable multicellular life. In cancer, integrins trigger and play key roles in all the features that were once described as the Hallmarks of Cancer. In this review, we will discuss the contribution of integrins to these hallmarks, including uncontrolled and limitless proliferation, invasion of tumor cells, promotion of tumor angiogenesis and evasion of apoptosis and resistance to growth suppressors, by highlighting the latest findings. Further on, given the paramount role of integrins in cancer, we will present novel strategies for integrin inhibition that are starting to emerge, promising a hopeful future regarding cancer treatment.

Integrin beta-3 genetic variants and risk of venous thromboembolism in colorectal cancer patients

Background Integrin β3 is involved in tumor and endothelial cell biology as well as in platelet aggregation. Herein, we evaluated the predictive potential of three germline single nucleotide polymorphisms (SNPs) in the integrin β3 gene (rs3809865, rs5918 and rs4642) to predict the risk of venous thromboembolism (VTE) in colorectal cancer (CRC) patients, which is one of the leading causes of death among cancer patients. Methods 112 patients diagnosed with CRC enrolled in the prospective Vienna Cancer and Thrombosis Study (CATS) were assessed with a median follow-up of 46 months. DNA was isolated from venous blood samples and SNPs were analyzed by the PCR-RFLP method. Results VTE occurred in 12% (n = 13) of all patients. The SNPs rs5918 and rs4642 were not associated with VTE risk. For rs3809565, 23% (n = 11) of patients had the A/A genotype, 4% (n = 2) had the A/T genotype, but none (0%) had the T/T genotype. In the univariate analysis, patients with the A/A genotype had a significantly higher risk to develop VTE compared to the other polymorphisms (P = 0.0005 after Fine and Gray). In the multivariable analysis, the predictive value remained significant. Conclusions This study identified the rs3809865 A/A genotype as an independent risk factor for VTE in CRC patients. Our findings would help identify high risk patients and would be essential for tailored anticoagulant prophylaxis.

Effects of cilengitide in osteoclast maturation and behavior.

Bone metastasis is a common burden in many types of cancer and has a severe impact on the quality of life in patients. Hence, specific therapeutic strategies inhibiting tumor induced osteolysis are urgently needed. In this study, we aimed to interfere with integrin adhesion receptors, which are central players of the bone resorption process. For this purpose, we used cilengitide, a cyclic RGD peptide, which blocks integrin αVβ3 and αVβ5-ligand binding. Our results revealed that cilengitide blocked osteoclast maturation in a dose-dependent manner. In detail, pre-osteoclasts treated with cilengitide exhibited reduced cell spreading, cell migration and cell adhesion on RGD-containing matrix proteins, which are ligands of integrin αV. The activation of the most upstream signal transduction molecules of the integrin receptor-initiated pathway, FAK and c-Src, were consistently blocked by cilengitide. First evidence suggests that cilengitide might interfere with metastatic bone disease in vivo and this study describes a potential underlying mechanism of the inhibitory effect of cilengitide on αV-integrin expressing pre-osteoclasts by blocking integrin ligand binding and interfering with osteoclast maturation and cell behavior. In conclusion, our findings suggest that cilengitide, which interferes with αV-integrins on osteoclasts, may represent a novel therapeutic strategy in the treatment of malignant bone disease.

Biochemical and genetic predictors of overall survival in patients with metastatic pancreatic cancer treated with capecitabine and nab-paclitaxel.

Pancreatic cancer is a dismal disease with a mortality rate almost similar to its incidence rate. To date, there are neither validated predictive nor prognostic biomarkers for this lethal disease. Thus, the aim of the present study was to retrospectively investigate the capability of biochemical parameters and molecular profiles to predict survival of patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) who participated in a phase II clinical trial to test the safety and efficacy of the combination treatment of capecitabine plus nab-paclitaxel. Herein, we investigated the association of 18 biochemical parameters obtained from routine diagnosis and the clinical outcome of the 30 patients enrolled in the clinical trial. Furthermore, we analysed formalin-fixed paraffin-embedded (FFPE) tumour tissue to identify molecular biomarkers via RNA seq and the Illumina TruSeq Amplicon Cancer panel which covers 48 hotspot genes. Our analysis identified SERPINB7 as a novel transcript and a DNA mutation signature that might predict a poor outcome of disease. Moreover, we identified the bilirubin basal level as an independent predictive factor for overall survival in our study cohort.

SERPINB7 Expression Predicts Poor Pancreatic Cancer Survival Upon Gemcitabine Treatment

Stratification of patients with pancreatic ductal adenocarcinoma (PDAC) remains a key challenge in the field of clinical oncology. No predictive biomarkers have yet been found for any available treatment options. Previously, we identified SERPINB7 as a putative biomarker for PDAC and thus, herein, we aimed to validate our previous findings and assessed the predictive value of SERPINB7. Patients who underwent surgery and received gemcitabine (gem) or gemcitabine plus nab-paclitaxel (gem/nab) as adjuvant therapy, between 2011 and 2017, were included in this study (n = 57). Expression level of SERPINB7 was assessed in tumor tissue by immunohistochemistry (IHC) and RNA in situ hybridization (RNA ISH). Its association with disease-free survival (DFS) and overall survival (OS) was investigated. While IHC did not show any correlation between survival and the protein level of SERPINB7, RNA ISH revealed that expression of SERPINB7 was associated with a poor DFS (P = .01) and OS (P = .002) in the gem group but not in the gem/nab. Adjusted Cox-regression analysis confirmed the independent predictive value of SERPINB7 on OS (P = .006, HR: 3.47; 95% CI: 1.49–8.09) in the gem group. In conclusion, SERPINB7 was identified as the first predictive RNA biomarker for PDAC. This study suggests that patients who expressed SERPINB7 might receive another treatment than gem alone.

Analysis of 10 Adrenocortical Carcinoma Patients in the Cohort of the Precision Medicine Platform MONDTI

Objective: Adrenocortical carcinoma (ACC) is a rare disease with a dismal prognosis. We aimed to evaluate if a personalized medicine approach may be useful for matching patients with ACC to targeted therapies. Methods: This is an analysis of 10 molecularly profiled ACCs that were progressing under standard of care treatment. The profile consisted of a 50-gene next-generation sequencing panel, immunohistochemistry (IHC), and fluorescence in situ hybridization for several proteins or chromosomal aberrations. Results: In 6 (60%) tumor samples, no somatic mutation was detected, while in 3 (30%) tumors 1 mutation was detected and in 1 (10%) tumor 2 mutations were detected. These mutations were CTNNB1 (2 samples), TP53 (1 sample), RB1 (1 sample) and APC (1 sample). Expression of phospho-mTOR and of EGFR was commonly detected by IHC (87.5 and 62.5%). In 4 (50%) samples, IHC revealed a weak expression of progesterone receptor. Less frequent alterations were expression of PDGFR-α, c-KIT, and estrogen receptor, each in 1 case. Conclusions: Based on the molecular profile, no recommendation for targeted therapy was made by the multi-disciplinary team. Currently, ACC might not be suitable for a precision medicine approach according to our tests.

Optimizing Treatment Sequence for Late-line Metastatic Colorectal Cancer Patients Using Trifluridine/Tipiracil and Regorafenib

Micro‐Abstract Regorafenib and thymidine‐based nucleoside trifluridine/tipiracil (TAS‐102) treatment sequencing for patients with refractory metastatic colorectal cancer (mCRC) is highly debated. A total of 85 patients with mCRC were included. Survival and the treatment response were evaluated and confirmed the efficacy of TAS‐102 and regorafenib in the real‐life setting. Background Treatment sequencing for patients with refractory metastatic colorectal cancer (mCRC) has been highly debated. The thymidine‐based nucleoside trifluridine/tipiracil (TAS‐102) and the multikinase inhibitor regorafenib have demonstrated clinical benefits in randomized phase III trials compared with placebo. However, limited data are available on the most optimal therapy sequence involving TAS‐102 and regorafenib. Patients and Methods In the present retrospective, observational, real‐life study, clinical data on mCRC patients treated with TAS‐102 or an alternative salvage treatment at the Medical University of Vienna and University Hospital Zurich were collected from January 2013 to December 2016. Results A total of 85 patients whose disease had progressed during fluoropyrimidine‐based therapy (FBT) with or without an antibody were included. The disease control rate in patients treated with TAS‐102 after FBT‐based treatment was 24% compared with 35% in patients treated with regorafenib after FBT‐based treatment (adjusted odds ratio, 1.75; 95% confidence interval, 0.41‐7.47; P = .449). The progression‐free survival (PFS) and overall survival (OS) for patients treated with TAS‐102 was 2.8 months (quartile, 2.0‐4.8 months) and 15.9 months, respectively. When the data were analyzed according to the subgroups of patients with or without an FBT‐free period, the TAS‐102–treated patients with a previous FBT‐free interval had a PFS of 3.1 months and OS of 17.7 months compared with a PFS of 2.2 months and OS of 8.1 months for patients who received TAS‐102 immediately after FBT. Conclusion Our results have confirmed the efficacy of TAS‐102 and regorafenib in the real‐life setting. The treatment sequence analysis showed a tendency for longer PFS and OS for TAS‐102–treated patients after an FBT‐free interval. Prospective randomized data are needed to gain more information about the most beneficial therapy sequence in the salvage treatment of mCRC.

Nab-paclitaxel as alternative treatment regimen in advanced cholangiocellular carcinoma.

BACKGROUND Advanced cholangiocellular carcinoma has a poor prognosis with limited therapeutic options. Nab-paclitaxel has recently been described to be beneficial in metastatic pancreatic cancer improving overall and progression free survival (PFS). The potential antitumor activity of nab-paclitaxel in cholangiocellular carcinoma is hitherto unknown. METHODS We retrospectively analyzed an institutional cholangiocellular carcinoma registry to determine the potential biological activity of nab-paclitaxel in advanced intrahepatic cholangiocellular carcinoma. Disease control rate (DCR), PFS and overall survival (OS) upon nab-paclitaxel based treatment, after failure of platinum-containing first-line combination chemotherapy, was assessed. RESULTS Twelve patients were identified. Five of 12 patients (42%) received nab-paclitaxel as second line, and 7 patients (56%) as third-line treatment. The objective DCR with nab-paclitaxel was 83% (10/12 patients). One patient had a complete remission (CR), two patients had a partial remission (PR) and 7 patients had stable disease (SD). Disease was rated progressive in two patients. In all 12 patients receiving nab-paclitaxel the median time to progression was 6 months (range, 2.1-19.5 months). Median OS after initiation of nab-paclitaxel treatment was 9 months (2.1-28.4 months). The median time of survival after diagnosis of advanced disease was 21.5 months, whereby 3 patients were alive at the date of censoring (04/01/2015). CONCLUSIONS This is the first report suggesting substantial antitumor activity of nab-paclitaxel in advanced cholangiocellular carcinoma. In this small series, nab-paclitaxel based salvage chemotherapy appears to have a biological activity by controlling the disease and positively affecting survival. Randomized trials in this disease entity and subgroup of patients are urged.

Abstract 406: Effects of an RGD peptide in osteoclast maturation and behavior as a therapeutic option for metastatic bone disease

Metastatic bone disease is a common feature of many types of cancer and has a severe impact on the quality of life of patients. Hence, specific therapeutic strategies inhibiting tumor induced osteolysis are urgently needed. In this study, we aimed to interfere with integrin adhesion receptors, which are central players of the bone resorption process, including osteoclastogenesis as well as osteoclast/bone matrix interaction. For this purpose, we used a cyclic RGD peptide which blocks integrin aVâ3 and aVâ5-ligand binding. Our results revealed that the RGD peptide blocked osteoclast maturation in a dose-dependent manner. In detail, pre-osteoclasts treated with the RGD peptide exhibited reduced cell spreading, migration and adhesion on RGD-containing matrix proteins, such as osteopontin and fibrinogen, which are ligands of integrin aVâ3. The activation of the most upstream signal transduction molecules of the integrin receptor-initiated pathway, such as FAK and c-Src, were consistently blocked by the RGD peptide. First evidence has suggested that the RGD peptide might interfere with metastatic bone disease in vivo and the evidence presented herein describes the underlying mechanisms of the inhibitory effect of the RGD peptide on aV-integrin expressing pre-osteoclasts by blocking integrin ligand binding and interfering with osteoclast maturation and cell behavior. In conclusion, our findings suggest that using an RGD peptide to interfere with aV-integrins on osteoclasts may represent a novel therapeutic strategy in the treatment of malignant bone disease. Citation Format: Gerald Prager, Daniela Bianconi, Anastasia Chilla, Alexandra Dorda, Nisha Geetha, Matthias Unseld, Despoina Sykoutri, Marina Poettler, Kurt Redlich, Christoph Zielinski. Effects of an RGD peptide in osteoclast maturation and behavior as a therapeutic option for metastatic bone disease. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 406. doi:10.1158/1538-7445.AM2015-406

556PINTEGRIN BETA-3 GENETIC VARIANTS PREDICT THE RISK OF THROMBO-EMBOLIC EVENTS IN PATIENTS WITH COLORECTAL CANCER

ABSTRACT Aim: Colorectal cancer patients are at increased risk for venous thromboembolism (VTE). Beta-3 integrin adhesion receptors play a central role in tumor cell biology, platelet aggregation and endothelial cell behavior. Therefore, we hypothesized that the germline single nucleotide polymorphisms (SNPs) rs3809865, which is thought to affect integrin expression, might predict the risk of VTE in colorectal cancer patients. Methods: 114/139 colorectal cancer patients were assessable for integrin beta-3 germline SNPs rs3809865 characterization within the study population recruited into the Vienna Cancer and Thrombosis Study (CATS) (Ay, C et al; JCO 2011 vol. 29 no. 15), an ongoing prospective observational cohort study initiated in October 2003 at the Medical University of Vienna. Whole blood samples were analyzed using PCR-RFLP or direct DNA-sequencing. VTE events were statistical analyzed using one-way Anova testing. Results: The patients demographics and tumor characteristics were balanced between groups. In 14 patients (12.28%) VTE occurred. 12 (25%) of 48 colorectal cancer patients with an rs3809865 A/A allele profile experienced a VTE, representing a statistical significant (p = 0.0015) increased risk of VTE when compared to other subgroups. Only 2 of 52 patients (3.85%) harboring an A/T allele VTE was of diagnosed and none (0%) of the T/T subgroup had any VTE. Other SNPs of the integrin beta-3 gene revealed no predictive value for VTE. In multivariable analysis including age, sex, chemotherapy, and anti-VEGF therapy rs3809865 A/A allele profile remained a statistical significant risk factor for VTE. Conclusions: This study identifies the germline polymorphisms in integrin beta-3 gene rs3809865 as independent prognostic markers for VTE in colorectal cancer. These data may help to select subgroups of patients who may benefit from an enforced prophylaxis of venous thromboembolism (VTE). Disclosure: All authors have declared no conflicts of interest.