Detección y significado clínico de la enfermedad mínima residual o micrometástasis en tumores sólidos

[Resumen] La detección de células tumorales circulantes (CTC) y diseminadas (CTD) podría ser importante para evaluar el pronóstico en pacientes con cáncer. No se ha definido el perfil molecular asociado con diseminación tumoral. Los microRNAs desempeñan un papel clave. En el primer artículo, se investiga la presencia de CTD en médula ósea en cáncer colorrectal (CCR), gástrico (CG) y pancreático y su asociación con el perfil de microRNAs. Los resultados muestran que las CTD y el incremento de miR-17-92 son potenciales marcadores pronósticos independientes. A continuación, el objetivo fue identificar nuevos biomarcadores de mRNA y miRNA. En el segundo artículo, se analizó el valor diagnóstico y pronóstico de AGR2 y LGR5 en sangre en CCR. Los resultados indican que AGR2 y LGR5 pueden reflejar la presencia de CTC, incluyendo células progenitoras. Los incrementos de AGR2 y LGR5 se asociaron con peor pronóstico. En los dos últimos artículos, se analiza si microRNAs circulantes de la familia miR- 200s podrían constituir biomarcadores en CG y cáncer de mama. La familia miR- 200s regula la migración y la invasión. Se encontró que el nivel de miR-200c circulante estaba desregulado en estos tumores en comparación con controles, siendo además, un factor pronóstico independiente en ambos tipos tumorales.[Resumo] A detección de células tumorais circulantes (CTC) e diseminadas (CTD) podería ser importante para avaliar a prognose en doentes con cancro. O perfil molecular asociado á diseminación tumoral, onde os microRNAs desenvolven un rol clave, aínda non foi definido. No primeiro artigo foi investigada a presenza de DTC na médula ósea e a súa asociación co perfil de microRNA nos tumores colorrectais (CRC), gástricos (CG) e de páncreas. Os resultados indican que o incremento de CTD e miR-17-92 son potenciais marcadores prognósticos independentes. A continuación, o obxectivo foi identificar novos biomarcadores de mRNA e microRNA. No segundo artigo, foi avaliado o valor diagnóstico e prognóstico de AGR2 e LGR5 no sangue en doentes con CCR. Os resultados indican que AGR2 e LGR5 poden reflectir a presenza de CTC, incluidas células proxenitoras. Os aumentos de AGR2 e LGR5 foron asociados cun peor prognóstico. Nos dous últimos artigos, analizouse se os microRNAs circulantes da familia mir- 200s poderían ser biomarcadores no CG e cancro de mama. A familia miR-200s regula a migración e a invasión. Encontrouse que o nivel de miR-200c circulante estaba desregulado nestes cancros en comparación cos controis, sendo ademais, un factor pronóstico independente en ámbolos dous tipos tumorais.Abstract Detection of circulating and disseminated tumor cells (CTC and DTC) could be important to evaluate the prognosis in cancer patients. However, the molecular profile associated with tumor dissemination has yet to be defined. MicroRNAs play key roles in cancer. In the first article, we investigated in patients with colorectal, gastric and pancreatic cancer whether the presence of DTC in bone marrow (BM) were associated with microRNA tumor profile. Our results suggest the presence of BM-DTC and the upregulation of miR-17-92 cluster are both significant but independent prognostic markers. Next, we aim to identify novel mRNA and miRNA biomarkers. In the second article, we estimated the diagnostic and prognostic values of AGR2 and LGR5 mRNAs in blood in colorectal cancer. Our findings indicate AGR2 and LGR5 might reflect the presence of CTC, including stem cell CTC. Increased AGR2 and LGR5 were associated to poor prognostic. In the last two articles, we hypothesized the quantitative PCR of the miR-200 family in the blood could be useful biomarkers for gastric and breast cancers. The miR-200s regulate invasiveness and migration. Circulating miR-200c levels were deregulated in cancer patients comparing to healthy controls. Furthermore, blood miR-200c levels were independent prognostic factors in gastric and breast cancers

Posttranscriptional regulation by RNA-binding proteins during epithelial-to-mesenchymal transition

Review[Abstract] Epithelial-to-mesenchymal transition (EMT), one of the crucial steps for carcinoma cells to acquire invasive capacity, results from the disruption of cell–cell contacts and the acquisition of a motile mesenchymal phenotype. Although the transcriptional events controlling EMT have been extensively studied, in recent years, several posttranscriptional mechanisms have emerged as critical in the regulation of EMT during tumor progression. In this review, we highlight the regulation of posttranscriptional events in EMT by RNA-binding proteins (RBPs). RBPs are responsible for controlling pre-mRNA splicing, capping, and polyadenylation, as well as mRNA export, turnover, localization, and translation. We discuss the most relevant aspects of RBPs controlling the metabolism of EMT-related mRNAs, and describe the implication of novel posttranscriptional mechanisms regulating EMT in response to different signaling pathways. Novel insight into posttranscriptional regulation of EMT by RBPs is uncovering new therapeutic targets in cancer invasion and metastasis.Xunta de Galicia; 10CSA916023PRXunta de Galicia; REGICC, CN2012/21

Multiple biomarker tissue arrays: a computational approach to identifying protein-protein interactions in the EGFR/ERK signalling pathway

[Abstract] Background. Many studies have demonstrated genetic and environmental factors that lead to renal cell carcinoma (RCC) and that occur during a protracted period of tumourigenesis. It appears suitable to identify and characterise potential molecular markers that appear during tumourigenesis and that might provide rapid and effective possibilities for the early detection of RCC. EGFR activation induces cell cycle progression, inhibition of apoptosis and angiogenesis, promotion of invasion/metastasis, and other tumour promoting activities. Over-expression of EGFR is thought to play an important role in tumour initiation and progression of RCC because up-regulation of EGFR has been associated with high grade cancers and a worse prognosis. Methods. Characterisation of the protein profile interacting with EGFR was performed using the following: an immunohistochemical (IHC) study of EGFR, a comprehensive computational study of EGFR protein-protein interactions, an analysis correlating the expression levels of EGFR with other significant markers in the tumourigenicity of RCC, and finally, an analysis of the utility of EGFR for prognosis in a cohort of patients with renal cell carcinoma. Results. The cases that showed a higher level of this protein fell within the clear cell histological subtype (p = 0.001). The EGFR significance statistic was found with respect to a worse prognosis. In vivo significant correlations were found with PDGFR-β, Flk-1, Hif1-α, proteins related to differentiation (such as DLL3 and DLL4 ligands), and certain metabolic proteins such as Glut5. In silico significant associations gave us a panel of 32 EGFR-interacting proteins (EIP) using the APID and STRING databases. Conclusions. This work summarises the multifaceted role of EGFR in the pathology of RCC, and it identifies EIPs that could help to provide mechanistic explanations for the different behaviours observed in tumours

Effect of a microtubule-targeting drug on cell–cell contacts in bladder epithelial tumour cells

Póste

Colorectal Cancer Classification and Cell Heterogeneity: A Systems Oncology Approach

Colorectal cancer is a heterogeneous disease that manifests through diverse clinical scenarios. During many years, our knowledge about the variability of colorectal tumors was limited to the histopathological analysis from which generic classifications associated with different clinical expectations are derived. However, currently we are beginning to understand that under the intense pathological and clinical variability of these tumors there underlies strong genetic and biological heterogeneity. Thus, with the increasing available information of inter-tumor and intra-tumor heterogeneity, the classical pathological approach is being displaced in favor of novel molecular classifications. In the present article, we summarize the most relevant proposals of molecular classifications obtained from the analysis of colorectal tumors using powerful high throughput techniques and devices. We also discuss the role that cancer systems biology may play in the integration and interpretation of the high amount of data generated and the challenges to be addressed in the future development of precision oncology. In addition, we review the current state of implementation of these novel tools in the pathological laboratory and in clinical practice.This work was supported by the “Galician Network for Colorectal Cancer Research (REGICC)”, funded by “Xunta de Galicia” (Ref. R2014/039), Spain. Federico Garrido would like to thank the financial support from the following institutions: “Instituto de Salud Carlos III” (CP03/0111, PI12/02031, PI08/1265, PI11/01022, PI11/01386, RETIC RD06/020, RD09/0076/00165, and PT13/0010/0039 projects; all actions co-funded with the European Regional Development Fund, FEDER), Spain; “Junta de Andalucía, Consejería de Salud e Innovación” (PI09/0382 project and CTS143 Research group), Spain; and European Commission (ENACT project: European Network for identification and validation of antigens and biomarkers in cancer and their application in clinical tumour immunology, LSHC-CT-2004-503306)

Clinical implications of epithelial cell plasticity in cancer progression

Mini-review[Abstract] In the last few years, the role of epithelial cell plasticity in cancer biology research has gained increasing attention. This concept refers to the ability of the epithelial cells to dynamically switch between different phenotypic cellular states. This programme is particularly relevant during the epithelial-to-mesenchymal transition (EMT) in cancer progression. During colonization, epithelial cells first activate the EMT programme to disseminate from a primary tumour to reach a distant tissue site. During this process, cells are transported into the circulation and are able to escape the immune system of the host. Then, a reverse process called mesenchymal-to-epithelial transition (MET) occurs on cells that settle in the distant organs. Although epithelial cell plasticity has an important impact on tumour biology, the clinical relevance of this concept remains to be recapitulated. In this review, we will update the current state of epithelial cell plasticity in cancer progression and its clinical implications for the design of therapeutic strategies, the acquisition of multidrug resistance, and future perspectives for the management of cancer patients.Instituto de Salud Carlos III; PI13/00250Xunta de Galicia; 10CSA916023PRXunta de Galicia; PS09/2

Origin of renal cell carcinomas

[Abstract] Cancer is a heritable disorder of somatic cells: environment and heredity are both important in the carcinogenic process. The primal force is the “two hits” of Knudson’s hypothesis, which has proved true for many tumours, including renal cell carcinoma. Knudson et al. [1, 2] recognised that familial forms of cancer might hold the key to the identification of important regulatory elements known as tumour-suppressor genes. Their observations (i.e., that retinoblastoma tend to be multifocal in familial cases and unifocal in sporadic presentation) led them to propose a two-hit theory of carcinogenesis. Furthermore, Knudson postulated that patients with the familial form of the cancer would be born with one mutant allele and that all cells in that organ or tissue would be at risk, accounting for early onset and the multifocal nature of the disease. In contrast, sporadic tumours would develop only if a mutation occurred in both alleles within the same cell, and, as each event would be expected to occur with low frequency, most tumours would develop late in life and in a unifocal manner [3, 4]. The kidney is affected in a variety of inherited cancer syndromes. For most of them, both the oncogene/tumour-suppressor gene involved and the respective germline mutations have been identified. Each of the inherited syndromes predisposes to distinct types of renal carcinoma. Families with hereditary predisposition to cancer continue to provide a unique opportunity for the identification and characterisation of genes involved in carcinogenesis. A surprising number of genetic syndromes predispose to the development of renal cell carcinoma, and genes associated with five of these syndromes have been already identified: VHL, MET, FH, BHD and HRPT2. Few cancers have as many different types of genetic predisposition as renal cancer, although to date only a small proportion of renal cell cancers can be explained by genetic predisposition

A randomised phase 2 study comparing different dose approaches of induction treatment of regorafenib in previously treated metastatic colorectal cancer patients (REARRANGE trial)

Colorectal cancer; Metastasis; RegorafenibCàncer colorectal; Metàstasi; RegorafenibCáncer colorrectal; Metástasis; RegorafenibPurpose: The purpose of this article is to evaluate the safety of two regorafenib dose-escalation approaches in refractory metastatic colorectal cancer (mCRC) patients. Patients and methods: Patients with mCRC and progression during or within 3 months following their last standard chemotherapy regimen were randomised to receive the approved dose of regorafenib of 160 mg QD (arm A) or 120 mg QD (arm B) administered as 3 weeks of treatment followed by 1 week off, or 160 mg QD 1 week on/1 week off (arm C). The primary end-point was the percentage of patients with G3/G4 treatment-related adverse events (AEs) in each arm. Results: There were 299 patients randomly assigned to arm A (n = 101), arm B (n = 99), or arm C (n = 99); 297 initiated treatments (arm A n = 100, arm B n = 98, arm C n = 99: population for safety analyses). G3/4 treatment-related AEs occurred in 60%, 55%, and 54% of patients in arms A, B, and C, respectively. The most common G3/4 AEs were hypertension (19, 12, and 20 patients), fatigue (20, 14, and 15 patients), hypokalemia (11, 7, and 10 patients), and hand-foot skin reaction (8, 7, and 3 patients). Median overall survival was 7.4 (IQR 4.0-13.7) months in arm A, 8.6 (IQR 3.8-13.4) in arm B, and 7.1 (IQR 4.4-12.4) in arm C. Conclusions: The alternative regorafenib dosing schedules were feasible and safe in patients with mCRC who had been previously treated with standard therapy. There was a higher numerical improvement on the most clinically relevant AEs in the intermittent dosing arm, particularly during the relevant first two cycles

New insights into molecular mechanisms of sunitinib-associated side effects

Review[Abstract] The introduction of targeted therapy represents a major advance in the treatment of tumor progression. Targeted agents are a novel therapeutic approach developed to disrupt different cellular signaling pathways. The tyrosine kinase inhibitor sunitinib specifically blocks multiple tyrosine kinase receptors that are involved in the progression of many tumors. Sunitinib is the current standard of care in first-line treatment of advanced renal cell carcinoma, and it is approved in imatinib-intolerant and imatinib-refractory gastrointestinal stromal tumors. However, it is increasingly evident that sunitinib may display collateral effects on other proteins beyond its main target receptors, eliciting undesirable and unexpected adverse events. A better understanding of the molecular mechanisms underlying these undesirable sunitinib-associated side effects will help physicians to maximize efficacy of sunitinib and minimize adverse events. Here, we focus on new insights into molecular mechanisms that may mediate sunitinib-associated adverse events

Hakai reduces cell-substratum adhesion and increases epithelial cell invasion

BACKGROUND: The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and normal tissue architecture. E-cadherin is the prototype and best-characterized protein member of adherens junctions in mammalian epithelial cells. Regarded as a tumour suppressor, E-cadherin loss is associated with poor prognosis in carcinoma. The E3 ubiquitin-ligase Hakai was the first reported posttranslational regulator of the E-cadherin complex. Hakai specifically targetted E-cadherin for internalization and degradation and thereby lowered epithelial cell-cell contact. Hakai was also implicated in controlling proliferation, and promoted cancer-related gene expression by increasing the binding of RNA-binding protein PSF to RNAs encoding oncogenic proteins. We sought to investigate the possible implication of Hakai in cell-substratum adhesions and invasion in epithelial cells. METHODS: Parental MDCK cells and MDCK cells stably overexpressing Hakai were used to analyse cell-substratum adhesion and invasion capabilities. Western blot and immunofluoresecence analyses were performed to assess the roles of Paxillin, FAK and Vinculin in cell-substratum adhesion. The role of the proteasome in controlling cell-substratum adhesion was studied using two proteasome inhibitors, lactacystin and MG132. To study the molecular mechanisms controlling Paxillin expression, MDCK cells expressing E-cadherin shRNA in a tetracycline-inducible manner was employed. RESULTS: Here, we present evidence that implicate Hakai in reducing cell-substratum adhesion and increasing epithelial cell invasion, two hallmark features of cancer progression and metastasis. Paxillin, an important protein component of the cell-matrix adhesion, was completely absent from focal adhesions and focal contacts in Hakai-overexpressing MDCK cells. The expression of Paxillin was found to be regulated by a proteasome-independent mechanism, possibly due to the decreased abundance of E-cadherin. CONCLUSIONS: Taken together, these results suggest that Hakai may be involved in two hallmark aspects of tumour progression, the lowering cell-substratum adhesion and the enhancement of cell invasion