MI-773 is a recently developed small-molecule inhibitor of the mouse double minute 2 (MDM2) proto-oncogene. Preclinical data on the anti-tumour activity of MI-773 are limited and indicate that tumour ...cell lines (CLs) with mutated TP53 are more resistant to MI-773 than wild type TP53. Here, we explored the compound's therapeutic potential in vitro using a panel of 274 annotated CLs derived from a diversity of tumours. MI-773 exhibited a pronounced selectivity and moderate potency, with anti-tumour activity in the sub-micromolar range in about 15% of the CLs. The most sensitive tumour types were melanoma, sarcoma, renal and gastric cancers, leukaemia, and lymphoma. A COMPARE analysis showed that the profile of MI-773 was similar to that of Nutlin-3a, the first potent inhibitor of p53-MDM2 interactions, and, in addition, had a superior potency. In contrast, it poorly correlates with profiles of compounds targeting the p53 pathway with another mechanism of action. OMICS analyses confirmed that MI-773 was primarily active in CLs with wild type TP53. In silico biomarker investigations revealed that the TP53 mutation status plus the aggregated expression levels of 11 genes involved in the p53 signalling pathway predicted sensitivity or resistance of CLs to inhibitors of p53-MDM2 interactions reliably. The results obtained for MI-773 could help to refine the selection of cancer patients for therapy.
Purpose
The transforming growth factor-beta (TGF-β) signaling pathway is known to play a critical role in promoting tumor growth. Consequently, blocking this pathway has been found to inhibit tumor ...growth. In order to achieve an optimal anti-tumor effect, however, it remains to be established whether blocking the TGF-β signaling pathway alone is sufficient, or whether the tumor microenvironment plays an additional, possibly synergistic, role.
Methods
To investigate the relevance of blocking TGF-β signaling in tumor cells within the context of their respective tissue microenvironments, we treated a panel of patient-derived xenografts (PDX) with the selective TGF-β receptor kinase inhibitor LY2157299 monohydrate (galunisertib) and assessed both the in vitro and in vivo effects.
Results
Galunisertib was found to inhibit the growth in an in vitro clonogenic assay in 6.3 % (5/79) of the examined PDX. Evaluation of the expression profiles of a number of genes, representing both canonical and non-canonical TGF-β signaling pathways, revealed that most PDX exhibited expression changes affecting TGF-β downstream signaling. Next, we subjected 13 of the PDX to an in vivo assessment and, by doing so, observed distinct response patterns. These results suggest that, next to intrinsic, also extrinsic or microenvironmental factors can affect galunisertib response. pSMAD2 protein expression and
TGF-βRI
mRNA expression levels were found to correlate with the in vivo galunisertib effects.
Conclusions
From our data we conclude that intrinsic, tumor-dependent TGF-β signaling does not fully explain the anti-tumor effect of galunisertib. Hence, in vivo xenograft models may be more appropriate than in vitro clonogenic assays to assess the anti-tumor activity of TGF-β inhibitors such as galunisertib.
Formation of blood vessels requires the concerted regulation of an unknown number of genes in a spatial-, time- and dosage-dependent manner. Determining genes, which drive vascular maturation is ...crucial for the identification of new therapeutic targets against pathological angiogenesis.
corrected We accessed global gene regulation throughout maturation of the chick chorio-allantoic membrane (CAM), a highly vascularized tissue, using pan genomic microarrays. Seven percent of analyzed genes showed a significant change in expression (>2-fold, FDR<5%) with a peak occurring from E7 to E10, when key morphogenetic and angiogenic genes such as BMP4, SMO, HOXA3, EPAS1 and FGFR2 were upregulated, reflecting the state of an activated endothelium. At later stages, a general decrease in gene expression occurs, including genes encoding mitotic factors or angiogenic mediators such as CYR61, EPAS1, MDK and MYC. We identified putative human orthologs for 77% of significantly regulated genes and determined endothelial cell enrichment for 20% of the orthologs in silico. Vascular expression of several genes including ENC1, FSTL1, JAM2, LDB2, LIMS1, PARVB, PDE3A, PRCP, PTRF and ST6GAL1 was demonstrated by in situ hybridization. Up to 9% of the CAM genes were also overexpressed in human organs with related functions, such as placenta and lung or the thyroid. 21-66% of CAM genes enriched in endothelial cells were deregulated in several human cancer types (P<.0001). Interfering with PARVB (encoding parvin, beta) function profoundly changed human endothelial cell shape, motility and tubulogenesis, suggesting an important role of this gene in the angiogenic process.
Our study underlines the complexity of gene regulation in a highly vascularized organ during development. We identified a restricted number of novel genes enriched in the endothelium of different species and tissues, which may play crucial roles in normal and pathological angiogenesis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Soft tissue sarcomas (STS) are rare, complex tumors with a poor prognosis. The identification of new prognostic biomarkers is needed to improve patient management. Our aim was to determine the ...methylation status of the 118 CpG sites in the PLAGL1 tumor-suppressor gene P1 CpG island promoter and study the potential prognostic impact of PLAGL1 promoter methylation CpG sites in STS. Training cohorts constituted of 28 undifferentiated sarcomas (US) and 35 leiomyosarcomas (LMS) were studied. PLAGL1 mRNA expression was investigated by microarray analysis and validated by RT-qPCR. Pyrosequencing was used to analyze quantitative methylation of the PLAGL1 promoter. Associations between global promoter or specific CpG site methylation and mRNA expression were evaluated using Pearson's product moment correlation coefficient. Cox univariate and multivariate proportional hazard models were used to assess the predictive power of CpG site methylation status. Sixteen CpG sites associated with PLAGL1 mRNA expression were identified in US and 6 in LMS. Statistical analyses revealed an association between CpG107 methylation status and both overall and metastasis-free survival in US, which was confirmed in a validation cohort of 37 US. The exhaustive study of P1 PLAGL1 promoter methylation identified a specific CpG site methylation correlated with mRNA expression, which was predictive for both metastasis-free and overall survival and may constitute the first US-specific biomarker. Such a biomarker may be relevant for identifying patients likely to derive greater benefit from treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In up to 30% of non-small cell lung cancer (NSCLC) patients, the oncogenic driver of tumor growth is a constitutively activated epidermal growth factor receptor (EGFR). Although these patients gain ...great benefit from treatment with EGFR tyrosine kinase inhibitors, the development of resistance is inevitable. To model the emergence of drug resistance, an EGFR-driven, patient-derived xenograft (PDX) NSCLC model was treated continuously with Gefitinib in vivo. Over a period of more than three months, three separate clones developed and were subsequently analyzed: Whole exome sequencing and reverse phase protein arrays (RPPAs) were performed to identify the mechanism of resistance. In total, 13 genes were identified, which were mutated in all three resistant lines. Amongst them the mutations in NOMO2, ARHGEF5 and SMTNL2 were predicted as deleterious. The 53 mutated genes specific for at least two of the resistant lines were mainly involved in cell cycle activities or the Fanconi anemia pathway. On a protein level, total EGFR, total Axl, phospho-NFκB, and phospho-Stat1 were upregulated. Stat1, Stat3, MEK1/2, and NFκB displayed enhanced activation in the resistant clones determined by the phosphorylated vs. total protein ratio. In summary, we developed an NSCLC PDX line modelling possible escape mechanism under EGFR treatment. We identified three genes that have not been described before to be involved in an acquired EGFR resistance. Further functional studies are needed to decipher the underlying pathway regulation.
Metastasis-Associated in Colon Cancer 1 (
) is a strong prognostic biomarker inducing proliferation, migration, invasiveness, and metastasis of cancer cells. The context of
dysregulation in cancers ...is, however, still poorly understood. Here, we investigated whether chromosomal instability and somatic copy number alterations (SCNA) frequently occurring in CRC contribute to
dysregulation, with prognostic and predictive impacts. Using the Oncotrack and Charité CRC cohorts of CRC patients, we showed that elevated
mRNA expression was tightly dependent on increased
gene SCNA and was associated with metastasis and shorter metastasis free survival. Deep analysis of the COAD-READ TCGA cohort revealed elevated
expression due to SCNA for advanced tumors exhibiting high chromosomal instability (CIN), and predominantly classified as CMS2 and CMS4 transcriptomic subtypes. For that cohort, we validated that elevated
mRNA expression correlated with reduced disease-free and overall survival. In conclusion, this study gives insights into the context of
expression in CRC. Increased
expression is largely driven by CIN, SCNA gains, and molecular subtypes, potentially determining the molecular risk for metastasis that might serve as a basis for patient-tailored treatment decisions.
Patient-derived xenografts (PDX) have emerged as an important translational research tool for understanding tumor biology and enabling drug efficacy testing. They are established by transfer of ...patient tumor into immune compromised mice with the intent of using them as Avatars; operating under the assumption that they closely resemble patient tumors. In this study, we established 27 PDX from 100 resected gastric cancers and studied their fidelity in histological and molecular subtypes. We show that the established PDX preserved histology and molecular subtypes of parental tumors. However, in depth investigation of the entire cohort revealed that not all histological and molecular subtypes are established. Also, for the established PDX models, genetic changes are selected at early passages and rare subclones can emerge in PDX. This study highlights the importance of considering the molecular and evolutionary characteristics of PDX for a proper use of such models, particularly for Avatar trials.
Systemic treatment is necessary for one third of patients with renal cell carcinoma. No valid biomarker is currently available to tailor personalized therapy. In this study we established a ...representative panel of patient derived xenograft (PDX) mouse models from patients with renal cell carcinomas and determined serum levels of high mobility group B1 (HMGB1) protein under treatment with sunitinib, pazopanib, sorafenib, axitinib, temsirolimus and bevacizumab. Serum HMGB1 levels were significantly higher in a subset of the PDX collection, which exhibited slower tumor growth during subsequent passages than tumors with low HMGB1 serum levels. Pre-treatment PDX serum HMGB1 levels also correlated with response to systemic treatment: PDX models with high HMGB1 levels predicted response to bevacizumab. Taken together, we provide for the first time evidence that the damage associated molecular pattern biomarker HMGB1 can predict response to systemic treatment with bevacizumab. Our data support the future evaluation of HMGB1 as a predictive biomarker for bevacizumab sensitivity in patients with renal cell carcinoma.
Abstract
In 2020, kidney cancers accounted for more than 4.1% of new cancer cases worldwide. Among these, more than 90% were renal cell carcinoma (RCC), a very heterogenous disease consisting of 3 ...major subtypes: chromophobe , papillary and clear cell. These subtypes differ in histology, genetic alterations, clinical outcome and therapeutic response. Over the last decades, great advances in the treatment of RCC have been made with additional targeting agents inhibiting RTKs, VEGFR and mTORC1. However, for local RCC surgery remains the main treatment modality whereas metastatic RCC is still difficult to treat due to chemoresistance. Antibody drug conjugates (ADC) or small molecule drug conjugates (SMDC) are emerging approaches for the treatment of cancer patients. By coupling highly potent chemotherapeutic agents to a specific antibody/small molecule, tumor cells can be selectively targeted allowing treatment with higher drug doses leading to an enhanced efficacy, while maintaining low toxicity in healthy tissues. 4HF Biotec has developed a proprietary database containing, among others, curated molecular data from tumor patient samples, preclinical models (cell lines, cell line-derived xenografts, and patient-derived xenografts) and normal tissues. Using this platform, we established a unique methodology to identify and prioritize genes that could be targeted by ADCs/SMDCs. By performing bioinformatics analyses of this molecular data, we identified genes that are differentially expressed across cancer (sub)types. We further selected those that are overexpressed in the tumor entity compared to matching normal tissue and in the tumor entity compared to all normal tissues. The overlapping genes were assessed in preclinical models to confirm their tumor-specificity. For the final selection, we investigated target druggability by curating data regarding protein function, targetability and localization. With this approach, we identified a total of 374 potential drug targets across 15 cancer (sub)types for the development of ADCs or SMDCs. Analyses of kidney cancer identified Semaphorin 5B (SEMA5B) among the top candidates. SEMA5B was significantly upregulated in patient samples of the kidney compared to other tumor entities. Comparison with normal kidney samples revealed a significant higher expression in tumor samples. In addition to the expression profiles, association between SEMA5B expression and clinical and molecular features will be presented. Furthermore, we will present curated information about protein function and structure that will facilitate antibody generation. Our findings indicate that targeting SEMA5B on tumor cells could represent a new therapeutic option in the treatment of renal cancer.
Citation Format: Alexandra Musch, Anne-Lise Peille, Hoor Al Hasani, Heinz-Herbert Fiebig, Vincent Vuaroqueaux. Identification of a promising renal cell carcinoma target using a unique in silico approach 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 LB107.
Abstract
Pancreatic cancer (PC) is the 12th most common cancer worldwide. Despite a large panel of chemo- and targeted therapeutics options, patient prognosis remains poor with a 5-years overall ...survival below 10%. Thus, there is still a critical need to develop more efficient therapeutic alternatives. Antibody drug conjugates (ADC) and small molecule drug conjugates (SMDC) combine the oncolytic activity of highly potent chemotherapies with the target specificity of an antibody or a small molecule. Both ADC and SMDC are of increasing interest for cancer treatment, as they allow more specific delivery of chemotherapies to the tumor site. Facing the clinical needs for PC treatment, here we present an in-silico analysis to reveal specific targets for further ADC/SMDC development. 4HF Biotec has developed a proprietary platform connecting large clinical, OMICS and drug sensitivity data from various sources. It includes annotation for more than 1,800 preclinical models (cell lines, cell line-derived xenografts, and patient-derived xenografts), up to 11,000 patient tumors and 22,000 normal tissues (TCGA, GTEx and various GEO datasets). For tumor target discovery purposes, we designed and implemented the platform with specific analytics tools. To identify specific targets for PC, we first decided to analyze preclinical models, to focus on genes expressed by tumor cells and not by stroma cells. This aspect is particularly important in the context of PC which often have a high stroma content. Differential gene expression analysis of 113 PC preclinical models versus 1,737 tumor models from up to 30 tumor entities revealed 327 PC specific genes potentially targetable. Then, a similar analysis was performed by testing TCGA patient tumors (179 pancreatic tumors vs 9,521 patient tumors from other entities) and revealed 1,292 pancreatic specific genes. Finally, PC patient tumors were compared to 709 samples from various normal organs allowing to identify 1,156 tumor specific genes. At the intersection of these three analyses, we identified 56 PC-specific target candidates for ADC/SMDC development. Among the top candidates, MUCL3 (mucin like 3) was one of the most promising genes. Its mRNA expression is almost exclusively restricted to pancreatic and stomach samples in both preclinical models and TCGA patient tumors. It is overall not frequently expressed by normal tissues, and restricted to subsets of stomach, esophagus, and lung samples. The gene encodes for a transmembrane protein with a long weakly glycosylated extracellular part. A detailed analysis of the protein characteristics and expression modalities will be shown. The present work demonstrates that our in silico platform helps to identify promising targets for PC treatment using ADC/SMDC approaches. Our analyses revealed MUCL3 as one of the top candidates, further analyses will be needed to determine its druggability using small molecules or antibodies.
Citation Format: Anne-Lise Peille, Alexandra Musch, Hoor Al-Hasani, Heinz-Herbert Fiebig, Vincent Vuaroqueaux. Identification of novel targets for the treatment of pancreatic cancer patients 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 1173.
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