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Supplementary methods and Figures S1-S17

Supplementary Figures and Tables

Purpose:Anti-EGFR mAbs are effective in the treatment of metastatic colorectal cancer (mCRC) patients. RAS status and tumor location (sidedness) are predictive markers of patients' response to anti-EGFR mAbs. Recently, low miR-31-3p expression levels have been correlated with clinical benefit from the anti-EGFR mAb cetuximab. Here, we aimed to validate the predictive power of miR-31-3p in a prospective cohort of chemorefractory mCRC patients treated with single-agent anti-EGFR mAbs.Experimental Design:miR-31-3p was tested by in situ hybridization (ISH) in 91 pretreatment core biopsies from metastatic deposits of 45 patients with mCRC. Sequential tissue biopsies obtained before treatment, at the time of partial response, and at disease progression were tested to monitor changes in miR-31-3p expression overtreatment. miR-31-3p expression, sidedness, and RAS status in pretreatment cell-free DNA were combined in multivariable regression models to assess the predictive value of each variable alone or in combination.Results:Patients with low miR-31-3p expression in pretreatment biopsies showed better overall response rate, as well as better progression-free survival and overall survival, compared to those with high miR-31-3p expression. The prognostic effect of miR-31-3p was independent from age, gender, and sidedness. No significant changes in the expression of miR-31-3p were observed when sequential tissue biopsies were tested in long-term or poor responders to anti-EGFR mAbs. miR-31-3p scores were similar when pretreatment biopsies were compared with treatment-naïve archival tissues (often primary colorectal cancer).Conclusions:Our study validates the role of miR-31-3p as potential predictive biomarker of selection for anti-EGFR mAbs.

Junctional adhesion molecules (JAMs) play a critical role in cell permeability, polarity and migration. JAM-A, a key protein of the JAM family, is altered in a number of conditions including cancer; however, consequences of JAM-A dysregulation on carcinogenesis appear to be tissue dependent and organ dependent with significant implications for the use of JAM-A as a biomarker or therapeutic target. Here, we test the expression and prognostic role of JAM-A downregulation in primary and metastatic colorectal cancer (CRC) (n = 947). We show that JAM-A downregulation is observed in ~60% of CRC and correlates with poor outcome in four cohorts of stages II and III CRC (n = 1098). Using JAM-A knockdown, re-expression and rescue experiments in cell line monolayers, 3D spheroids, patient-derived organoids and xenotransplants, we demonstrate that JAM-A silencing promotes proliferation and migration in 2D and 3D cell models and increases tumour volume and metastases in vivo. Using gene-expression and proteomic analyses, we show that JAM-A downregulation results in the activation of ERK, AKT and ROCK pathways and leads to decreased bone morphogenetic protein 7 expression. We identify MIR21 upregulation as the cause of JAM-A downregulation and show that JAM-A rescue mitigates the effects of MIR21 overexpression on cancer phenotype. Our results identify a novel molecular loop involving MIR21 dysregulation, JAM-A silencing and activation of multiple oncogenic pathways in promoting invasiveness and metastasis in CRC.

Circulating tumour DNAs and non-coding RNAs present in body fluids have been under investigation as tools for cancer diagnosis, disease monitoring, and prognosis for many years. These so-called liquid biopsies offer the opportunity to obtain information about the molecular make-up of a cancer in a minimal invasive way and offer the possibility to implement theranostics for precision oncology. Furthermore, liquid biopsies could overcome the limitations of tissue biopsies in capturing the complexity of tumour heterogeneity within the primary cancer and among different metastatic sites. Liquid biopsies may also be implemented to detect early tumour formation or to monitor cancer relapse of response to therapy with greater sensitivity compared with the currently available protein-based blood biomarkers. Most colorectal cancers are often diagnosed at late stages and have a high mortality rate. Hence, biomolecules as nucleic acids present in liquid biopsies might have prognostic potential and could serve as predictive biomarkers for chemotherapeutic regimens. This review will focus on the role of circulating tumour DNAs and non-coding RNAs as diagnostic, prognostic, and predictive biomarkers in the context of colorectal cancer.

Non-coding RNAs represent a significant proportion of the human genome. After having been considered as 'junk' for a long time, non-coding RNAs are now well established as playing important roles in maintaining cellular homeostasis and functions. Some non-coding RNAs show cell- and tissue-specific expression patterns and are specifically deregulated under pathological conditions (e.g. cancer). Therefore, non-coding RNAs have been extensively studied as potential biomarkers in the context of different diseases with a focus on microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) for several years. Since their discovery, miRNAs have attracted more attention than lncRNAs in research studies; however, both families of non-coding RNAs have been established to play an important role in gene expression control, either as transcriptional or post-transcriptional regulators. Both miRNAs and lncRNAs can regulate key genes involved in the development of cancer, thus influencing tumour growth, invasion, and metastasis by increasing the activation of oncogenic pathways and limiting the expression of tumour suppressors. Furthermore, miRNAs and lncRNAs are also emerging as important mediators in drug-sensitivity and drug-resistance mechanisms. In the light of these premises, a number of pre-clinical and early clinical studies are exploring the potential of non-coding RNAs as new therapeutics. The aim of this review is to summarise the latest knowledge of the use of miRNAs and lncRNAs as therapeutic tools for cancer treatment.

FOLFIRINOX, a combination of chemotherapy drugs (Fluorouracil, Oxaliplatin, Irinotecan -FOI), provides the best clinical benefit in pancreatic ductal adenocarcinoma (PDAC) patients. In this study we explore the role of miRNAs (MIR) as modulators of chemosensitivity to identify potential biomarkers of response. We find that 41 and 84 microRNA inhibitors enhance the sensitivity of Capan1 and MiaPaCa2 PDAC cells respectively. These include a MIR1307-inhibitor that we validate in further PDAC cell lines. Chemotherapy-induced apoptosis and DNA damage accumulation are higher in MIR1307 knock-out (MIR1307KO) versus control PDAC cells, while re-expression of MIR1307 in MIR1307KO cells rescues these effects. We identify binding of MIR1307 to CLIC5 mRNA through covalent ligation of endogenous Argonaute-bound RNAs cross-linking immunoprecipitation assay. We validate these findings in an in vivo model with MIR1307 disruption. In a pilot cohort of PDAC patients undergoing FOLFIRONX chemotherapy, circulating MIR1307 correlates with clinical outcome., Understanding which patients will respond to FOLFIRINOX therapy is important for clinical outcome. Here, the authors show that the MIR1307 is increased pancreatic cancer cell lines and inhibition of the microRNA sensitises cells to treatment.’ stratifying patients to achieve the best clinical outcome. Here, the authors show that the MIR1307 is increased in a subgroup of human pancreatic cancers and inhibition of the microRNA in in vitro and in vivo models of pancreatic cancer sensitises cells to treatment.

Purpose Incidence and mortality of biliary tract carcinoma (BTC) are increasing, especially in South America and Asia. Such a disease often bears a dismal prognosis because of diagnosis occurring at late stages and for the frequent relapses after surgery. The aims of this review were to summarize the state of the art of the treatment of BTC and give a view at possible future prospects linked with molecular profiling, immunotherapy, and targeted therapies. Design We conducted a systematic literature search using MEDLINE and the 2018 ASCO Meeting abstract databases to identify published clinical trials, translational series, and meeting abstracts. All significant papers and abstracts available to date were included. Results For resected BTC, thanks to the BILCAP study, adjuvant chemotherapy (CT) with capecitabine should be regarded as the new standard of care. For locally advanced inoperable and metastatic diseases, the use of chemoradiotherapy and radioembolization has not been supported by any randomized Phase III study. The standard of care remains the combination of CT with gemcitabine and cisplatin, as reported by the ABC-02 trial. All targeted therapies have failed to improve the survival outcomes, either in combination with CT or as single agents and are not recommended in the treatment of BTC. Whole-exome sequencing and molecular profiling have helped in identifying genetic signatures typical of different BTC subtypes. With this support, new trials with targeted agents and immunotherapy have been designed, and results are awaited. Conclusion BTC still remains a disease with very few treatment options. Different BTC subtypes own peculiar gene mutations and pathways alterations. Therefore, molecular profiling may be the only key to enable new tailored strategies with targeted agents and immunotherapy.

Oesophageal cancer is one of the most aggressive malignancies with limited treatment options, thus resulting in a high morbidity and mortality. With 5‑year survival rates of only 5‑10%, oesophageal cancer holds a dismal prognosis for patients. In order to improve overall survival, the early diagnosis and tools for patient stratification for personalized treatment are urgent needs. A minority of oesophageal cancers belong to the spectrum of Lynch syndrome‑associated cancers and are characterized by microsatellite instability (MSI). Microsatellite instability is a consequence of defective mismatch repair protein functions and it has been well characterized in other gastrointestinal tumours, such as colorectal and gastric cancer. In the latter, high levels of MSI are associated with a better prognosis and with an increased benefit to immune‑based therapies. Therefore, similar therapeutic approaches could offer an opportunity of treatment for oesophageal cancer patients with MSI. Apart from immune checkpoint inhibitors, other immunotherapies such as adoptive T‑cell transfer, peptide vaccine and oncolytic viruses are under investigation in oesophageal cancer patients. In the present review, the rationale and current knowledge about immunotherapies in oesophageal cancer are summarised.

Pancreatic cancer is one of the most aggressive malignancies with limited treatment options thus resulting in high morbidity and mortality. Among all cancers, with a five-year survival rates of only 2–9%, pancreatic cancer holds the worst prognostic outcome for patients. To improve the overall survival, an earlier diagnosis and stratification of cancer patients for personalized treatment options are urgent needs. A minority of pancreatic cancers belong to the spectrum of Lynch syndrome-associated cancers and are characterized by microsatellite instability (MSI). MSI is a consequence of defective mismatch repair protein functions and it has been well characterized in other gastrointestinal tumors such as colorectal and gastric cancer. In the latter, high levels of MSI are linked to a better prognosis and to an increased benefit to immune-based therapies. Therefore, the same therapies could offer an opportunity of treatment for pancreatic cancer patients with MSI. In this review, we summarize the current knowledge about immune-based therapies and MSI in pancreatic cancer.

MicroRNAs are small RNA transcripts involved in fine-tuning of several cellular mechanisms and pathways crucial for maintaining cells' homeostasis like apoptosis, differentiation, inflammation and cell-cycle regulation. They act by regulation of gene expression at post-transcriptional level through fine-tuning of target proteins expression. Expression of microRNAs is cell-type specific and since their discovery they have been proven to be deregulated in various disorders including cancer. Several lines of evidence are emerging that link microRNAs to drug resistance mechanisms in tumours given their important role in modulating oncogenic and tumour suppressive mechanisms. This review will focus on latest knowledge of the roles and mechanisms of microRNAs as mediators to drug resistance and the implications for future therapies.

The main intent of secondary prevention strategies for Barrett's esophagus (BE) patients relies in the prompt identification of patients with dysplasia (or intra-epithelial neoplasia; IEN) and early-stage adenocarcinoma (Barrett's adenocarcinoma; BAc). Despite the adequate characterization of the molecular landscape characterizing Barrett's carcinogenesis, no tissue and/or circulating biomarker has been approved for clinical use. A series of 25 serum samples (12 BE, 5 HG-IEN and 8 BAc) were analyzed for comprehensive miRNA profiling and ten miRNAs were found to be significantly dysregulated. In particular seven were upregulated (i.e. miR-92a-3p, miR-151a-5p, miR-362-3p, miR-345-3p, miR-619-3p, miR-1260b, and miR-1276) and three downregulated (i.e. miR-381-3p, miR-502-3p, and miR-3615) in HG-IEN/BAc samples in comparison to non-dysplastic BE. All the identified miRNAs showed significant ROC curves in discriminating among groups with AUC values range of 0.75-0.83. Validation of the results were performed by droplet digital PCR in two out of three tested miRNAs. To understand the cellular source of circulating miR-92a-3p, we analyzed its expression in endoscopy biopsy samples by both qRT-PCR and ISH analyses. As observed in serum samples, miR-92a-3p was over-expressed in HG-IEN/BAc samples in comparison to naive esophageal squamous mucosa and BE and was mainly localized within the epithelial cells, supporting neoplastic cells as the main source of the circulating miRNA. Our data further demonstrated that circulating miRNAs are a promising mini-invasive diagnostic tool in the secondary follow-up and management of BE patients. Larger multi-Institutional studies should validate and investigate the most adequate miRNAs profile in discriminating BE patients in specific risk classes.

Aberrant changes in microRNA expression contribute to lymphomagenesis. Bromodomain and extra-terminal domain inhibitors such as OTX015 (MK-8628, birabresib) have demonstrated preclinical and clinical activity in hematologic tumors. MicroRNA profiling of diffuse large B-cell lymphoma cells treated with OTX015 revealed changes in the expression levels of a limited number of microRNAs, including miR-92a-1-5p, miR-21-3p, miR-155-5p and miR-96-5p. Analysis of publicly available chromatin immunoprecipitation sequencing data of diffuse large B-cell lymphoma cells treated with bromodomain and extra-terminal domain (BET) inhibitors showed that the BET family member BRD4 bound to the upstream regulatory regions of multiple microRNA genes and that this binding decreased following BET inhibition. Alignment of our microRNA profiling data with the BRD4 chromatin immunoprecipitation sequencing data revealed that microRNAs downregulated by OTX015 also exhibited reduced BRD4 binding in their promoter regions following treatment with another bromodomain and extra-terminal domain inhibitor, JQ1, indicating that BRD4 contributes directly to microRNA expression in lymphoma. Treatment with bromodomain and extra-terminal domain inhibitors also decreased the expression of the arginine methyltransferase PRMT5, which plays a crucial role in B-cell transformation and negatively modulates the transcription of miR-96-5p. The data presented here indicate that in addition to previously observed effects on the expression of coding genes, bromodomain and extra-terminal domain inhibitors also modulate the expression of microRNAs involved in lymphomagenesis.

Receptor tyrosine kinases (RTKs) are widely expressed transmembrane proteins that act as receptors for growth factors and other extracellular signalling molecules. Upon ligand binding, RTKs activate intracellular signalling cascades, and as such are involved in a broad variety of cellular functions including differentiation, proliferation, migration, invasion, angiogenesis, and survival under physiological as well as pathological conditions. Aberrant RTK activation can lead to benign proliferative conditions as well as to various forms of cancer. Indeed, more than 70% of the known oncogene and proto-oncogene transcripts involved in cancer code for RTKs. Consequently, these receptors are broadly studied as targets in the treatment of different tumours, and a large variety of small-molecule tyrosine kinase inhibitors (TKIs) are approved for therapy. In most cases, patients develop resistance to the TKIs within a short time. MicroRNAs are short (18-22 nucleotides) non-protein-coding RNAs that fine-tune cell homeostasis by controlling gene expression at the post-transcriptional level. Deregulation of microRNAs is common in many cancers, and increasing evidence exists for an important role of microRNAs in the development of resistance to therapies, including TKIs. In this review we focus on the role of microRNAs in mediating resistance to small-molecule TKIs in solid tumours.

Cancer organoids to model therapy response Cancer organoids are miniature, three-dimensional cell culture models that can be made from primary patient tumors and studied in the laboratory. Vlachogiannis et al. asked whether such “tumor-in-a-dish” approaches can be used to predict drug responses in the clinic. They generated a live organoid biobank from patients with metastatic gastrointestinal cancer who had previously been enrolled in phase I or II clinical trials. This allowed the authors to compare organoid drug responses with how the patient actually responded in the clinic. Encouragingly, the organoids had similar molecular profiles to those of the patient tumor, reinforcing their value as a platform for drug screening and development. Science , this issue p. 920

Background Intratumor heterogeneity (ITH) is described as the presence of various clones within one tumor, each with their own unique features in terms of morphology, inflammation, genetics or transcriptomics. Heterogeneity provides the fuel for drug resistance; therefore, an accurate assessment of tumor heterogeneity is essential for the development of effective therapies. The purpose of this study was to dissect morphologic and molecular ITH in colorectal adenocarcinoma. Materials and methods A series of 120 V600EBRAF-mutated (V600EBRAFmt) consecutive metastatic colorectal adenocarcinomas was assessed for morphologic heterogeneity. The two heterogeneous components of each specimen underwent a histopathological, immunohistochemical and molecular characterization to evaluate: histologic variant, grading, tumor-infiltrating lymphocytes (TILs), mismatch repair proteins' expression, KRAS/BRAF/NRAS mutations, microsatellite instability (MSI) status and consensus molecular subtype (CMS). Results Thirty-one out of 120 (25.8%) V600EBRAFmt primary colorectal adenocarcinomas presented a heterogeneous morphology. Among these, eight cases had adequate material for molecular profiling. Five out of the eight (62.5%) cases resulted instable at MSI testing. The majority (62.5%) of the samples showed a CMS4 phenotype based on gene expression profiling. Heterogeneity in CMS classification was observed in four out of eight cases. One out of eight cases presented significant heterogeneity in the number of TILs between the two components of the tumor. Conclusions Although the distribution of the immune infiltrate appears relatively conserved among heterogeneous areas of the same tumor, changes in gene expression profile and CMS occur in 50% of V600EBRAFmt adenocarcinoma cases in our small series and might contribute to variability in response to anticancer therapy and clinical outcomes. Assessment of morphological and molecular ITH is needed to improve colorectal cancer classification and to tailor anticancer treatments and should be included in the pathology report.

Introduction: Monoclonal antibodies against the Epidermal Growth Factor Receptor (EGFR) such as cetuximab or panitumumab are used for the treatment of metastatic colorectal cancer (mCRC) patients. Unfortunately, most patients develop resistance against these therapies within months. Several studies have shown that aberrations in the RAS pathway are responsible for resistance. However, even in metastases that are refractory to anti-EGFR treatment a significant fraction of RAS wild-type (wt) cells remain. These findings suggest a cross-talk between RAS mutant and wt cells in mediating resistance in the wt compartment. Methods: Mouse and patient-derived organoids from mCRC as well as CRC cell lines were used to test the contribution of extracellular vesicles in mediating resistance in RAS wt cells. Using conditioned media, transfection experiments and liquid biopsies (plasma and urine) from patients differential expression of the let-7g microRNA was demonstrated in microvesicles from cetuximab sensitive and resistant cells. Changes in expression of let-7g were further analyzed by in-situ hybridization in tissues. Results: Conditioned media from RAS mutant organoids rendered RAS wt organoids resistant against cetuximab treatment. Basal let-7g expression from pre-treatment plasma and urine samples of RAS wt patients correlated with clinical outcome and changes in let-7g circulating levels mirrored clinical behavior. In-situ hybridization in tissues confirmed changes in expression of the let-7g microRNA observed in plasma and urine samples. Conclusions: Our data suggest that let-7g microRNA might function as a paracrine mediator of anti-EGFR resistance and might be exploited as a non-invasive biomarker of resistance to cetuximab treatment. Further work is ongoing to characterize the molecular mechanisms underpinning let-7g mediated effect on anti-EGFR sensitivity in RAS wt CRC cells. Citation Format: Jens C. Hahne, Andrea Lampis, Michele Ghidini, Margherita Ratti, Chiara Senti, Rodolfo Passalacqua, Luciano Cascione, Chiara Braconi, Owen Sansom, Matteo Fassan, Nicola Valeri. Expression of exosomal let-7g in biofluids and outcome in colon cancer patient treated with anti-EGFR therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2373.

The association between antibiotic use and risk of cancer development is unclear, and clinical trials are lacking. We performed a systematic review and meta-analysis of observational studies to assess the association between antibiotic use and risk of cancer. PubMed, the Cochrane Library and EMBASE were searched from inception to 24 February 2019 for studies reporting antibiotic use and subsequent risk of cancer. We included observational studies of adult subjects with previous exposure to antibiotics and available information on incident cancer diagnoses. For each of the eligible studies, data were collected by three reviewers. Risk of cancer was pooled to provide an adjusted odds ratio (OR) with a 95% confidence interval (CI). The primary outcome was the risk of developing cancer in ever versus non-antibiotic users. Cancer risk&rsquo, s association with antibiotic intake was evaluated among 7,947,270 participants (n = 25 studies). Overall, antibiotic use was an independent risk factor for cancer occurrence (OR 1.18, 95%CI 1.12&ndash, 1.24, p &lt, 0.001). The risk was especially increased for lung cancer (OR 1.29, 95%CI 1.03&ndash, 1.61, p = 0.02), lymphomas (OR 1.31, 95%CI 1.13&ndash, 1.51, p &lt, 0.001), pancreatic cancer (OR 1.28, 95%CI 1.04&ndash, 1.57, p = 0.019), renal cell carcinoma (OR 1.28, 95%CI 1.1&ndash, 1.5, p = 0.001), and multiple myeloma (OR 1.36, 95%CI 1.18&ndash, 1.56, p &lt, 0.001). There is moderate evidence that excessive or prolonged use of antibiotics during a person&rsquo, s life is associated with slight increased risk of various cancers. The message is potentially important for public health policies because minimizing improper antibiotic use within a program of antibiotic stewardship could also reduce cancer incidence.

Background and Aims: Changes in single microRNA (miRNA) expression have been associated with chemo-resistance in biliary tract cancers (BTCs). However, a global assessment of the dynamic role of the microRNome has never been performed to identify potential therapeutic targets that are functionally relevant in the BTC cell response to chemotherapy. Approach and Results: High-throughput screening (HTS) of 997 locked nucleic acid miRNA inhibitors was performed in six cholangiocarcinoma cell lines treated with cisplatin and gemcitabine (CG) seeking changes in cell viability. Validation experiments were performed with mirVana probes. MicroRNA and gene expression was assessed by TaqMan assay, RNA-sequencing, and in situ hybridization in four independent cohorts of human BTCs. Knockout of microRNA was achieved by CRISPR-CAS9 in CCLP cells (MIR1249KO) and tested for effects on chemotherapy sensitivity in vitro and in vivo. HTS revealed that MIR1249 inhibition enhanced chemotherapy sensitivity across all cell lines. MIR1249 expression was increased in 41% of cases in human BTCs. In validation experiments, MIR1249 inhibition did not alter cell viability in untreated or dimethyl sulfoxide–treated cells; however, it did increase the CG effect. MIR1249 expression was increased in CD133+ biliary cancer cells freshly isolated from the stem cell niche of human BTCs as well as in CD133+ chemo-resistant CCLP cells. MIR1249 modulated the chemotherapy-induced enrichment of CD133+ cells by controlling their clonal expansion through the Wnt-regulator FZD8. MIR1249KO cells had impaired expansion of the CD133+ subclone and its enrichment after chemotherapy, reduced expression of cancer stem cell markers, and increased chemosensitivity. MIR1249KO xenograft BTC models showed tumor shrinkage after exposure to weekly CG, whereas wild-type models showed only stable disease over treatment. Conclusions: MIR1249 mediates resistance to CG in BTCs and may be tested as a target for therapeutics.

A 59-year-old patient underwent the duodenal endoscopic mucosal resection of a hyperplastic polyp. Four hours after the procedure she developed severe epigastric pain. Laboratory and imaging results were consistent with mild acute edematous pancreatitis. After several days of dietary therapy and intravenous crystalloid fluids the patient recovered, and 1 month later was asymptomatic and had no signs of pancreatic inflammation. This case illustrates a rare but clinically important complication of therapeutic upper endoscopy, which may be attributable to thermal injury of the duodenal wall and the adjacent pancreas. It also underscores the importance of the close follow up of patients who undergo invasive endoscopic procedures and the need for additional preventive measures to be taken when resecting duodenal lesions.

Trastuzumab in combination with chemotherapy represents the standard of care in HER2-positive advanced gastro-esphageal cancer (GOC), but development of resistance limits response. MicroRNAs (miRs) modulate key pathways in GOC. Identification of miRs responsible for resistance to HER2 inhibition may help stratify patients, predict response and define novel strategies to restore drug sensitivity. A high-throughput LNA™ miR-inhibitor screen in HER2-positive NCI-N87 and HER2-negative FLO-1 GOC cell lines was performed in order to identify potential miRs involved in trastuzumab sensitivity/resistance. Cells were treated with a combination of cisplatin, 5FU, and trastuzumab. MiRs were considered significant if LNAs caused >40% reduction in cell viability 72 hours post treatment relative to controls with a t-test p-value of In NCI-N87 and FLO-1 cell lines, 59 and 37 LNAs respectively caused >40% reduction in cell viability compared to controls (p Our screen identified a panel of miRs associated with GOC resistance to HER2 inhibitors in combination with chemotherapy. Inhibition of these miRs affects GOC cell viability and restores sensitivity. MiR-148a-3p emerged as a potential biomarker of resistance and further evaluation is underway in the PLATFORM trial (NCT02678182). Citation Format: Hazel Lote, Andrea Lampis, George Vlachogiannis, Jens Hahne, Sing-Yu Moorcraft, Michael Davidson, Carolin Fong, Ruwaida Begum, Matteo Fassan, Sheela Rao, David Watkins, Naureen Starling, Ian Chau, David Cunningham, Nicola Valeri. MicroRNAs as biomarkers of resistance to HER2 inhibition in combination with chemotherapy in gastro-esophageal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 258.

Non-coding RNAs are important regulators of gene expression and transcription. It is well established that impaired non-coding RNA expression especially the one of long non-coding RNAs and microRNAs is involved in a number of pathological conditions including cancer. Non-coding RNAs are responsible for the development of resistance to anticancer treatments as they regulate drug resistance-related genes, affect intracellular drug concentrations, induce alternative signaling pathways, alter drug efficiency via blocking cell cycle regulation, and DNA damage response. Furthermore, they can prevent therapeutic-induced cell death and promote epithelial–mesenchymal transition (EMT) and elicit non-cell autonomous mechanisms of resistance. In this review, we summarize the role of non-coding RNAs for different mechanisms resulting in drug resistance (e.g., drug transport, drug metabolism, cell cycle regulation, regulation of apoptotic pathways, cancer stem cells, and EMT) in the context of gastrointestinal cancers.

Gastric cancer is one of the most aggressive malignancies, with limited treatment options in both locally advanced and metastatic setting, resulting in poor prognosis. Based on genomic characterization, stomach tumour has recently been described as a heterogeneous disease composed by different subtypes, each of them with peculiar molecular aspects and specific clinical behaviour. With an incidence of 22% among all western gastric tumour cases, stomach cancer with microsatellite instability was identified as one of these subgroups. Retrospective studies and limited prospective trials reported differences between gastric cancers with microsatellite stability and those with instability, mainly concerning clinical and pathological features, but also in regard to immunological microenvironment, correlation with prognostic value, and responses to treatment. In particular, gastric cancer with microsatellite instability constitutes a small but relevant subgroup associated with older age, female sex, distal stomach location, and lower number of lymph-node metastases. Emerging data attribute to microsatellite instability status a favourable prognostic meaning, whereas the poor outcomes reported after perioperative chemotherapy administration suggest a detrimental role of cytotoxic drugs in this gastric cancer subgroup. The strong immunogenicity and the widespread expression of immune-checkpoint ligands make microsatellite instability subtype more vulnerable to immunotherapeutic approach, e.g., with anti-PD-L1 and anti-CTLA4 antibodies. Since gastric cancer with microsatellite instability shows specific features and clinical behaviour not overlapping with microsatellite stable disease, microsatellite instability test might be suitable for inclusion in a diagnostic setting for all tumour stages to guarantee the most targeted and effective treatment to every patient.

Background Following neoadjuvant chemotherapy for operable gastroesophageal cancer, lymph node metastasis is the only validated prognostic variable; however, within lymph node groups there is still heterogeneity with risk of relapse. We hypothesized that gene profiles from neoadjuvant chemotherapy treated resection specimens from gastroesophageal cancer patients can be used to define prognostic risk groups to identify patients at risk for relapse. Patients and methods The Medical Research Council Adjuvant Gastric Infusional Chemotherapy (MAGIC) trial (n = 202 with high quality RNA) samples treated with perioperative chemotherapy were profiled for a custom gastric cancer gene panel using the NanoString platform. Genes associated with overall survival (OS) were identified using penalized and standard Cox regression, followed by generation of risk scores and development of a NanoString biomarker assay to stratify patients into risk groups associated with OS. An independent dataset served as a validation cohort. Results Regression and clustering analysis of MAGIC patients defined a seven-Gene Signature and two risk groups with different OS [hazard ratio (HR) 5.1; P

KRAS mutation has been reported as a marker of radio-resistance in rectal cancer and unfavourable outcome in both colon and rectal cancer. This study suggests that a single-nucleotide polymorphism of the KRAS gene (LCS-6 variant) may predict response to neoadjuvant treatment and mitigate the poor prognosis associated with KRAS mutation in locally advanced rectal cancer., Background Lethal-7 (let-7) is a tumour suppressor miRNA which acts by down-regulating several oncogenes including KRAS. A single-nucleotide polymorphism (rs61764370, T > G base substitution) in the let-7 complementary site 6 (LCS-6) of KRAS mRNA has been shown to predict prognosis in early-stage colorectal cancer (CRC) and benefit from anti-epidermal growth factor receptor monoclonal antibodies in metastatic CRC. Patients and methods We analysed rs61764370 in EXPERT-C, a randomised phase II trial of neoadjuvant CAPOX followed by chemoradiotherapy, surgery and adjuvant CAPOX plus or minus cetuximab in locally advanced rectal cancer. DNA was isolated from formalin-fixed paraffin-embedded tumour tissue and genotyped using a PCR-based commercially available assay. Kaplan–Meier method and Cox regression analysis were used to calculate survival estimates and compare treatment arms. Results A total of 155/164 (94.5%) patients were successfully analysed, of whom 123 (79.4%) and 32 (20.6%) had the LCS-6 TT and LCS-6 TG genotype, respectively. Carriers of the G allele were found to have a statistically significantly higher rate of complete response (CR) after neoadjuvant therapy (28.1% versus 10.6%; P = 0.020) and a trend for better 5-year progression-free survival (PFS) [77.4% versus 64.5%: hazard ratio (HR) 0.56; P = 0.152] and overall survival (OS) rates (80.3% versus 71.9%: HR 0.59; P = 0.234). Both CR and survival outcomes were independent of the use of cetuximab. The negative prognostic effect associated with KRAS mutation appeared to be stronger in patients with the LCS-6 TT genotype (HR PFS 1.70, P = 0.078; HR OS 1.79, P = 0.082) compared with those with the LCS-6 TG genotype (HR PFS 1.33, P = 0.713; HR OS 1.01, P = 0.995). Conclusion This analysis suggests that rs61764370 may be a biomarker of response to neoadjuvant treatment and an indicator of favourable outcome in locally advanced rectal cancer possibly by mitigating the poor prognosis of KRAS mutation. In this setting, however, this polymorphism does not appear to predict cetuximab benefit.

Although biliary tract cancers (BTCs) are known to have an inflammatory component, a detailed characterisation of immune-related transcripts has never been performed. In these studies, nCounter PanCancer Immune Profiling Panel was used to assess the expression of 770 immune-related transcripts in the tumour tissues (TTs) and matched adjacent tissues (ATs) of resected BTCs. Cox regression analysis and Kaplan–Meier methods were used to correlate findings with relapse-free survival (RFS). The first analysis in the TT and AT of an exploratory set (n = 22) showed deregulation of 39 transcripts associated with T-cell activation. Risk of recurrence was associated with a greater number of genes deregulated in AT in comparison to TT. Analysis in the whole set (n = 53) showed a correlation between AT cytotoxic T-lymphocyte antigen-4 (CTLA4) expression and RFS, which maintained statistical significance at multivariate analysis. CTLA4 expression correlated with forkhead box P3 (FOXP3) expression, suggesting enrichment in T regulatory cells. CTLA4 is known to act by binding to the cluster of differentiation 80 (CD80). No association was seen between AT CD80 expression and RFS. However, CD80 expression differentiated prognosis in patients who received adjuvant chemotherapy. We showed that the immunomodulatory transcriptome is deregulated in resected BTCs. Our study includes a small number of patients and does not enable to draw definitive conclusions; however, it provides useful insights into potential transcripts that may deserve further investigation in larger cohorts of patients. Transcript Profiling Nanostring data have been submitted to GEO repository: GSE90698 and GSE90699., Highlights • BTCs harbour a derangement of immune-related transcripts with an important role for the cytotoxic T-lymphocyte antigen-4 (CTLA4) axis. • CTLA4 expression in the peritumoural areas correlates with outcome and represents a potential promising prognostic factor. • Our data suggest that immunotherapy may have an impact in BTCs as a mean to re-address the host immune response to the tumour.

Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. In the last 10 years, clinical trials have established multitargeted tyrosine kinase inhibitors (TKIs) as the standard first-line treatment in patients with metastatic disease. Multiple agents are now available for treatment in subsequent lines.The mammalian target of rapamycin (mTOR) inhibitors (e.g., everolimus alone or with lenvatinib) are among the most effective options. Areas covered: This paper provides a complete and updated overview on mTOR inhibitors for the treatment of advanced RCC. The authors revised the results of the most recent completed clinical trials and provided information about ongoing trials. Expert opinion: mTOR pathway still represents an important driver for RCC management. Combination of everolimus and lenvatinib is considered a category 1 choice with cabozantinib and nivolumab for subsequent therapy in metastatic RCC according to NCCN guidelines v2.2017. These three treatments (levantinib/everolimus, cabozantinib, and nivolumab) all resulted in a superior efficacy compared to everolimus alone. Moreover, mTOR inhibitors, and in particular temsirolimus for poor risk patients, are available choices for treatment in non-clear cell carcinomas together with TKIs.

Sequential profiling of plasma cell-free DNA (cfDNA) holds immense promise for early detection of patient progression. However, how to exploit the predictive power of cfDNA as a liquid biopsy in the clinic remains unclear. RAS pathway aberrations can be tracked in cfDNA to monitor resistance to anti-EGFR monoclonal antibodies in patients with metastatic colorectal cancer. In this prospective phase II clinical trial of single-agent cetuximab in RAS wild-type patients, we combine genomic profiling of serial cfDNA and matched sequential tissue biopsies with imaging and mathematical modeling of cancer evolution. We show that a significant proportion of patients defined as RAS wild-type based on diagnostic tissue analysis harbor aberrations in the RAS pathway in pretreatment cfDNA and, in fact, do not benefit from EGFR inhibition. We demonstrate that primary and acquired resistance to cetuximab are often of polyclonal nature, and these dynamics can be observed in tissue and plasma. Furthermore, evolutionary modeling combined with frequent serial sampling of cfDNA allows prediction of the expected time to treatment failure in individual patients. This study demonstrates how integrating frequently sampled longitudinal liquid biopsies with a mathematical framework of tumor evolution allows individualized quantitative forecasting of progression, providing novel opportunities for adaptive personalized therapies. Significance: Liquid biopsies capture spatial and temporal heterogeneity underpinning resistance to anti-EGFR monoclonal antibodies in colorectal cancer. Dense serial sampling is needed to predict the time to treatment failure and generate a window of opportunity for intervention. Cancer Discov; 8(10); 1270–85. ©2018 AACR. See related commentary by Siravegna and Corcoran, p. 1213. This article is highlighted in the In This Issue feature, p. 1195

Background: \ud Patients often ask oncologists how long a cancer has been present before causing symptoms or spreading to other organs. The evolutionary trajectory of cancers can be defined using phylogenetic approaches but lack of chronological references makes dating the exact onset of tumours very challenging.\ud \ud Patients and methods: \ud Here, we describe the case of a colorectal cancer (CRC) patient presenting with synchronous lung metastasis and metachronous thyroid, chest wall and urinary tract metastases over the course of 5 years. The chest wall metastasis was caused by needle tract seeding, implying a known time of onset. Using whole genome sequencing data from primary and metastatic sites we inferred the complete chronology of the cancer by exploiting the time of needle tract seeding as an in vivo ‘stopwatch’. This approach allowed us to follow the progression of the disease back in time, dating each ancestral node of the phylogenetic tree in the past history of the tumour. We used a Bayesian phylogenomic approach, which accounts for possible dynamic changes in mutational rate, to reconstruct the phylogenetic tree and effectively ‘carbon date’ the malignant progression.\ud \ud Results: \ud The primary colon cancer emerged between 5 and 8 years before the clinical diagnosis. The primary tumour metastasized to the lung and the thyroid within a year from its onset. The thyroid lesion presented as a tumour-to-tumour deposit within a benign Hurthle adenoma. Despite rapid metastatic progression from the primary tumour, the patient showed an indolent disease course. Primary cancer and metastases were microsatellite stable and displayed low chromosomal instability. Neo-antigen analysis suggested minimal immunogenicity.\ud \ud Conclusion: \ud Our data provide the first in vivo experimental evidence documenting the timing of metastatic progression in CRC and suggest that genomic instability might be more important than the metastatic potential of the primary cancer in dictating CRC fate.

The aim of the study was to collect the available data on central nervous system (CNS) metastases from esophageal and gastric cancer. A PubMed, EMBASE, SCOPUS, Web of Science, LILACS, Ovid and Cochrane Library search was performed. Thirty-seven studies including 779 patients were considered. Among the data extracted, treatment of tumor and brain metastases (BMs), time to BMs development, number and subsite, extracerebral metastases rate, median overall survival (OS) and prognostic factors were included. For esophageal cancer, the median OS from diagnosis of BMs was 4.2 months. Prognostic factors for OS included: performance status, multimodal therapy, adjuvant chemotherapy, single BM, brain only disease and surgery. For gastric cancer, median OS was 2.4 months. Prognostic factors for OS included: recursive partitioning analysis class 2, stereotactic radiosurgery (SRT) and use of intrathecal therapy. HER2-positive gastric cancer was shown to be associated with a higher risk and shorter time to CNS relapse. Patients harboring BMs from gastric and esophageal tumors, except cases with single lesions that are treated aggressively, have a poor prognosis. SRT (plus or minus surgery and whole brain radiotherapy) seems to give better results in terms of longer OS after brain relapse.

Endometrial carcinoma is the most common gynaecological malignancy. Nevertheless there is a lack of curative therapies, especially for patients diagnosed with late stage, recurrent or aggressive disease, who have a poor prognosis. Cordyceps Sinensis, Ganoderma lucidum and Agaricus Blazi Murill are three fungi widely used in traditional Chinese medicine, and effects as adjuvants in tumour therapy have been demonstrated. However, the function and effects of these fungi in regard to endometrial cancer are not known. Three endometrial cancer cell lines, Ishikawa, Hec-1A and AN3-CA (derived from endometrial cancers grade I, II and III, respectively), were used to determine the effect of the fungi extracts on endometrial cancer cell function and to analyze the molecular mechanism. All fungi extracts had an inhibitory effect on cell viability and proliferation most probably exerted through induction of autophagy. Our data suggest that these fungi extracts may be used as adjuvants in endometrial tumour therapy.

Background FOLFIRINOX-regime is a combination-chemotherapy that provides the best clinical benefit in pancreatic ductal adenocarcinoma (PDAC) patients, but is associated with severe toxicity. Aim of this study is to explore the role of miRNAs as modulators of chemosensitivity and their potential as biomarkers of sensitivity to FOLFIRINOX-therapy. Methods HTS of 997 LNA-MIR-inhibitors was performed in PDAC cell lines treated with a combination of Fluorouracil (F), Oxaliplatin (O) and Irinotecan (I) that mimics FOLFIRINOX-regime. Validation experiments were performed with miRvana probes. Apoptosis was measured by flow-cytometry and western-blotting. Knock-out of microRNA was achieved by CRISPR-CAS9 in MiaPaca2 cells. HITS-CLIP assay was used to identify MIR1307 target site. Drug sensitivity was tested in xenograft models. Plasma MIR1307 was assessed by ddPCR. Results 41 and 84 miRNA-inhibitors enhanced FOI activity by > 30% (p Conclusions We identified MIR1307 as a potential modulator of sensitivity to FOI-chemotherapy in PC. MIR1307 inhibition impairs the ability of the cells to recover from chemotherapy damage and therefore enhances its activity. Legal entity responsible for the study The authors. Funding Pancreatic Cancer UK Research Innovation Fund, Cancer Research UK. Disclosure All authors have declared no conflicts of interest.

Background Monoclonal antibodies against the Epidermal Growth Factor Receptor (EGFR) such as cetuximab or panitumumab are used for the treatment of metastatic colorectal cancer (mCRC) patients. Unfortunately, most patients develop resistance against these therapies within months. Several studies have shown that aberrations in the RAS pathway are responsible for resistance. However, even in metastases that are refractory to anti-EGFR treatment a significant fraction of RAS wild-type (wt) cells remain. These findings suggest a cross-talk between RAS mutant and wt cells in mediating resistance in the wt compartment. Methods We used mouse and patient-derived organoids from mCRC as well as CRC cell lines to test the contribution of extracellular vesicles in mediating resistance in RAS wt cells. Using conditioned media, transfection experiments and liquid biopsies (plasma and urine) from patients differential expression of the let-7g microRNA was demonstrated in microvesicles from cetuximab sensitive and resistant cells. Changes in expression of the let-7g microRNA were further analysed by in-situ hybridization in tissues. Results Basal let-7g expression from pre-treatment plasma and urine samples of RAS wt patients correlated with clinical outcome and changes in let-7g circulating levels mirrored clinical behaviour. In-situ hybridization in tissues confirmed changes in expression of the let-7g microRNA observed in plasma and urine samples. Conclusions Our data suggest that let-7g microRNA might function as a paracrine mediator of anti-EGFR resistance and might be exploited as a non-invasive biomarker of resistance to cetuximab treatment. Further work is ongoing to characterize the molecular mechanisms underpinning let-7g mediated effect on anti-EGFR sensitivity in RAS wt CRC cells. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure N. Valeri: Speaker Bureau / Expert testimony: Bayer; Speaker Bureau / Expert testimony: Eli Lilly; Speaker Bureau / Expert testimony: Pfizer; Speaker Bureau / Expert testimony: Merck. All other authors have declared no conflicts of interest.

e15566 Background: Identification of prognostic biomarkers for gastric cancer (GC) patient selection is compelling to improve survival outcomes. Microsatellite instability (MSI) is related with a positive prognostic effect in GC, whereas perioperative chemotherapy resulted detrimental in this subgroup. In metastatic GC, immunotherapy with anti-PD1/PD-L1 drugs has shown promising results. Nevertheless, in early stages, data on the relation between MSI, clinic-pathological features, PD-L1 expression and overall survival (OS) remains sparse, especially in Western population. In our study, the prognostic role of MSI, clinic-pathological features and PD-L1 expression in a cohort of Italian GC patients was examined. Methods: CP data of 148 consecutive stage I-III GC pts resected in Cremona Institute between 2010 and 2014 (mostly chemo and/or radio-naive) were collected. MSI analysis was performed on tissue samples for all cases by polymerase chain reaction. PDL-1 expression, evaluated by immunohistochemistry, was assessed in MSI group. Differences between subgroups were evaluated with Chi-square test; Kaplan-Meier method and Long Rank test were used to calculate OS. Results: Female sex (p=0.012), earlier TNM stages (p=0.011) and limited nodal involvement (p=0.29) significantly correlated with MSI status. MSI is significantly associated with better prognosis, exhibiting an advantage of 28.6 months in OS compared with microsatellite stable subgroup (p

e14545 Background: Liquid biopsies (LB) allow monitoring of genetically different and co-occurring cancer cell clones present in primary tumor and all metastatic sites in parallel. In metastatic colorectal cancer (mCRC), circulating-free DNA (cfDNA) can be relevant for monitoring treatment and identification of molecular alterations resulting in disease relapse often earlier than radiological examinations. Methods: Patients with mCRC at diagnosis and treated with chemotherapy (CT) in combination with antibodies (bevacizumab, cetuximab or panitumumab) before undergoing surgery for resectable disease were included in this study. LB were collected before therapy start, every four weeks during treatment, within ten days of radiological disease evaluation, at radiological relapse and until two months after relapse. Next generation sequencing based on plasma samples was performed (testing for mutations and copy number variations covering 77 genes). Results: From February 2016 to October 2018, 14 patients having surgery after first line treatment were included herein; median follow-up was 21.5 months. Five of them had RAS wild-type disease and received CT plus anti-EGFR treatment, while nine RAS mutated mCRC patients received bevacizumab. Surgery was radical in 10 cases, with no further treatment. In four cases, surgery was not radical and required further treatment. Disease relapse happened in seven cases, with subsequent death in three cases. In six out of seven cases, gene alterations were already detected in the pre-operative cfDNA. In the seven cases without disease relapse, gene variants were detected even after the surgery in two patients despite receiving radical resection. Median number of gene variants was two. Beside the well-established mutations in TP53 gene, both APC and ROS1 gene mutations were frequent, while further evaluations are required for the other variants detected. Conclusions: Evaluation of cfDNA mutations in LB from mCRC may be a useful tool for monitoring clinical response and predict treatment outcome. Moreover, this molecular analysis can help to subgroup patients with regard to risk of relapse after radical surgery. Indeed, cfDNA mutations present before surgery seem to be an indication for a higher risk of post-surgery disease relapse.

548 Background: RAS status in tissue and/or liquid biopsies and tumour location (sidedness) are predictive markers of patients’ response to anti-EGFR mABs. MiR-31-3p expression has been correlated with clinical benefit from anti-EGFR mABs with chemotherapy. We aimed to validate the predictive power of miR-31-3p in a prospective cohort of chemo-refractory mCRC patients treated with single agent anti-EGFR mABs in the PROSPECT-C trial (NCT02994888). Methods: MiR-31-3p was tested by in-situ hybridization in 91 pre-treatment (PT) core biopsies from 45 mCRC patients. Sequential tissue biopsies obtained PT, at time of best response and at disease progression were tested to monitor changes in miR-31-3p expression over treatment. In 34 patients miR-31-3p, gender, sidedness, previous lines of treatment and RAS status in PT cell free (cf) DNA were evaluated in multivariate Cox and logistic regression models. Results: Patients with low miR-31-3p expression in PT biopsies showed better overall response rate (ORR: 58.3% vs 22.2%), median progression free survival (mPFS: 4.21 vs 2.27 months) and overall survival (mOS: 4.21 vs 2.27 mo) compared to those with high miR-31-3p expression (Hazard Ratio for PFS high vs low: 1.96; 95% CI: 0.98-3.88; p: 0.06 and HR for OS high vs low: 2.14; 95% CI: 1.04- 4.40; p: 0.04) adjusting for age, gender and sidedness. There was significant association between ORR and miR-31-3p expression (χ2 test p: 0.029). MiR-31-3p expression was an independent predictor of response, adjusting for gender, previous treatment lines and RAS (odds ratio: 0.14; 95% CI: 0.02-1.00, p: 0.048). A trend towards improved mPFS (5.10 vs 2.27 mo) and mOS (15.23 vs 4.67 mo) was noted in miR31-3p low vs high group in cfDNA RAS wild-type patients. No significant change in miR-31-3p expression were observed in archival tissue and sequential tissue biopsies. Conclusions: Our study validates the role of miR-31-3p as potential predictive biomarker of selection for anti-EGFR mABs. Further studies are needed to test if miR-31-3p combined with cfDNA RAS test can identify best responders in specific clinical niches.

The association of folinate salts with 5-fluorouracil (5-FU) represents a gold standard in the treatment of many cancers. In several clinical trials, the simultaneous administration of calcium–folinic acid (Ca-FA) and the prolonged infusion of 5-FU resulted in a better clinical response compared with fluoropyrimidine alone and 5-FU bolus. However, the simultaneous infusion of 5-FU and Ca-FA mixed in the same infusion pump is hindered by the crystallization of calcium salts, which eventually leads to catheter obstruction and damage. The sodium salt of leucovorin-disodium levofolinate (Na-Lv) is a novel molecule with a pharmacological profile similar to Ca-FA. Owing to its higher solubility, it can be safely mixed with 5-FU in a single pump without the risk of precipitation and catheter occlusion. The efficacy and safety of Na-Lv have been widely examined in preclinical and clinical phase II studies in combination with various schedules of 5-FU and in several cancer types. PubMed, EMBASE, SCOPUS and Web of Science databases were searched from inception to November 2018 to retrieve available published phase I and II series, including Western patients. Compared with Ca-FA, Na-Lv shows a more favourable efficacy and toxicity profile in terms of overall response rate, progression-free survival, time to progression and occurrence of severe adverse events. Moreover, it allows treatment time to be shortened, decreasing the number of required human resources for drug administration and limiting the occurrence of catheter damage.

Osteopontin-1 is a well characterized protein in many tumour entities. Multiple roles in the processes invasion, metastasis and angiogenesis of tumours are attributed to osteopontin-1. The putative role of osteopontin-1 has not been characterized for endometrial cancer. We investigated multiple endometrial cancer cell lines for osteopontin-1 mRNA- and protein-expression. Osteopontin-1 dependent effects were analysed in vitro by siRNA inhibition. All endometrial cell lines expressed osteopontin-1. Expression of osteopontin-1 was successfully inhibited by specific siRNA. Cells with reduced osteopontin-1 expression showed decreased migration in the Boyden chamber assay and invasion was reduced in the wound-healing assay. Osteopontin-1 seems to play a role in apoptotic processes of endometrial cancer cells. Inhibition of osteopontin-1 expression was associated with an increased susceptibility for radiation therapy. Osteopontin-1 seems to play a role in endometrial cancer. Inhibition of osteopontin-1 expression leads to a higher susceptibility for radiation therapy. Our results suggest that a reduced expression of osteopontin-1 in endometrial cancer could inhibit the development of invasion and metastasis in these cells.

Triple negative breast cancers (TNBC) are associated with an adverse outcome, although these tumors are sensitive to chemotherapy. In part, this phenomenon could be caused by tumor immune escape. The current study investigates immunogenicity of TNBC cells in vitro and the presence of immunosuppressive factors in the tumor microenvironment (pAKT and B7H1 expression, infiltration with regulatory T cells, [Tregs]). Natural killer (NK)-cell induced lysis was evaluated in estrogen receptor (ER) positive MCF 7 breast cancers, in MDA-MB231 and MDA-MB468 and in HCC-1937 (BRCA 1 mutated) and HCC-1806 TNBC cells. Expression of pAKT, B7H1 and infiltration with Tregs were determined by immunohistochemistry in human specimens of benign and malignant breast disease. NK-cell induced lysis was significantly increased (p

Platinum-resistance is the most crucial problem for treatment of ovarian cancer. There is a clinical need for new treatment strategies which overcome platinum resistance. As survival is strongly influenced by immunological parameters, immunotherapeutic strategies appear promising. Therefore a better understanding of the interaction between ovarian tumour cells and cells of the immune system is a necessary prerequisite. In the present study we aimed to enlighten the interactions between platinum resistant and platinum sensitive ovarian cancer cells and natural-killer (NK)-cells. Modified FATAL assay was used for determining the killing efficiency of NK-cells for the parental A2780 cells and the cis-platinum resistant A2780cis human ovarian cancer cells. Expression of pro- and anti-apoptotic genes as well as ligands involved in NK-cell receptor recognition were analysed by RT-PCR and flow cytometric analysis. The efficiency of NK mediated cell lysis differs between A2780 cells and the cis-platinum-resistant A2780cis cells. A2780cis cells are less accessible for NK-cell mediated killing. Based on this observation we characterized the molecular basis for resistance mechanisms. Besides an increase in anti-apoptotic genes (especially CIAP-1 and -2) that probably render A2780cis cells more resistant against apoptosis an increased amount of soluble MICA/B seems to be responsible for the lower killing rate of platinum-resistant A2780cis cells compared to their parental A2780 cells.