This chapter intends to introduce the new concepts that have been established in molecular biology over the last years and are being applied in translational research. The chapter is divided in four big blocks, which treat the molecular biology concepts and techniques in relation to DNA, RNA, proteins and metabolites, respectively. Moreover, we give examples of translational application of these new methodologies described.
Molecular biology has been one of the scientific disciplines in which there has been more advances in the last years. The first impulse in the study of genetic alterations came from the discovery of DNA structure, followed by elucidation of the genetic code, the discovery of restriction enzymes and subsequently the invention of PCR, not forgetting the exponential development of computer science. All of them have allowed us to know much more about our genome and its regulation than we could imagine. The impulse in proteomics has been especially in tune up of soft methods of ionization coupled with mass spectrometry. Nevertheless, this seems to be only the beginning since today there are continuous methodological advances that will increase more, without doubt, the knowledge and applications in this discipline.
OBJECTIVES: The advances in cancertranslational research, as well as the study of its changesand interactions, depend basically on the procurementof case series (individuals affected and non affectedcontrols) which supply high quality samples and otherassociated data. Biobanks have shown they areindispensable tools for the advance of uro-oncologicalresearch.METHODS: Bibliographic review based on biobankswith focus on Urology.RESULTS AND CONCLUSIONS: Well-organized, largebiobanks are a key element in research in Uro-oncology.The integration of theses resources with molecular sciencesand various “omics”, together with powerful availablebioinformatic tools enable the advance in the knowledgeof development of uro-oncological diseases, with strongimplications at the time of very advanced therapeuticstrategies. However, in Spain, these valuable collectionsof tissue material and biological fluids are usually not muchin use, mainly due to fragmentation, low accessibility,lack of proper management strategies (such as lack ofconsensus about standard operative procedures), limitedspecific policies of use and distribution, as well as lackof a comprehensive base in which the research needsare reflected under interdisciplinar and multi-institutionalfocus. We must add the frequent ignorance of the highscientific potential of these institutions in the urologicalworld. The development of the Spanish National Plan ofBiobanks brings light for the better use of these materialsby the uro-oncological community. We present a generalview on the biobank topic, which may serve as a modelfor future debates about their use in uro-oncology. Thisapproach is based in data from the literature and resultsof discussions in various international forums
The accelerated expansion of the knowledge of genetic and molecular basics of cancer, together with the recent development of molecular biology techniques, have had a significant impact in the field of oncology, among other medical disciplines. So, over the last few years, we are crossing from an empiricism-based model to an evidence-based model in which drugs are adapted depending of the molecular alterations which result crucial for tumor development (both for carcinogenesis and acquisition of an aggressive phenotype leading to tumor invasion and resistance to therapy). The molecular alterations /variations offer the possibility of being detected and used as biomarkers in clinical practice. Biomarkers may have multiple applications in the field of oncology, from determining the risk to suffer the disease to prediction of response to therapy, including diagnosis, prognosis and disease monitoring, with the final aim of performing a more personalized medicine and achieving greater efficacy for the therapies selected, diminishing each therapy`s own adverse events. Considering the importance biomarkers may get to have in clinical decision making, it is basic that their development is performed under straight evaluation and validation rules. In this article we review the various types of biomarkers and the basic methodological principles for their development, validation and subsequent clinical application.
Alterations in DNA methylation have been described in human cancer for more than thirty years now. Since the last decade DNA methylation gets more and more important in cancer research. In this review the different alterations of DNA methylation are discussed in testicular germ cell tumours, Wilms’ tumours, renal cell carcinomas, urothelial cell carcinomas of the bladder and adenocarcinomas of the prostate. Eventually, the potential use in diagnostics, prognostics and therapy are discussed.
The great number of biomarkers basic research is presenting in different clinical scenarios of prostate cancer demands the scientific community rigor in their molecular and clinical development for the selection of those which could supply diagnostic and prognostic information for the established nomograms of clinical-pathological factors. Prostate cancer, due to its prevalence and heterogeneity, needs a more directed diagnosis, characterization of malignant potential and monitoring of its multiple therapies. In this review article we try to go over the recent incorporation of new serum and urine markers in the clinical management of this tumor, emphasizing those with greater clinical development.
Prostate cancer cells express the androgen receptor (AR) and need the presence of androgens to survive. Androgen suppression is the gold standard first-line therapy for metastatic disease. Almost all prostate cancer patients initially respond to hormonal therapy, but most of them gradually develop castration-resistant progression. Recent evidence has shown that progression at the castration resistant prostate cancer (CRPC) stage is often mediated by AR signalling. Importantly, subsequent AR androgen inhibition, by abiraterone acetate or enzalutamide, has shown to improve patients´ survival. Several mechanisms that enhance AR signalling in an androgen-depleted environment have been elucidated: (1) AR mutations that allow activation by low androgen levels or by other endogenous steroids, (2) AR amplification and/or overexpression, (3) increased local intracrine synthesis of androgens, (4) changes in AR cofactors and (5) cross-talk with cytokines and growth factors. Today, there are under development a number of novel agents targeting the AR signaling pathway. This article reviews the postulated mechanisms of AR-driven resistance to androgen suppression that have contributed to the development of new hormonal therapeutic strategies in prostate cancer
Bone metastases are a frequent and devastating complication in cancer patients. Recently, significant advances in our understanding of the molecular mechanisms responsible for both osteolytic and osteoblastic bone metastases have occurred. The use of OMICS and the availability of appropriate preclinical animal models of bone metastasis have permitted the identification of factors produced by the tumor or by the host stroma in response to the tumor. These types of studies should result in a decrease of the serious skeletal morbidities associated with metastatic prostate cancer and may in the future improve overall survival. In this review the next generation of molecular targets in bone metastasis will be summarized.
Tumors constitute complex ecosystems with multiple interactions among neoplastic cells displaying various phenotypes and functions and where the tumoral niche is built with an active participation of the host environment that also impacts the malignant progression of the tumor cells. Irrespective of the cell of origin of prostate adenocarcinoma, mounting evidences support the existence of a hierarchy within neoplastic prostate cells that contributes to the heterogeneity of these tumors. At the origin of this hierarchy are small populations of tumor cells with high self-renewal potential and also capable of generating progeny tumor cells that lose selfrenewal properties as they acquire more differentiated phenotypes. These cancer stem cells (CSC) depend on active gene networks that confer them with their self-renewal capacity through symmetrical divisions whereas Arch. Esp. Urol. 2013; 66 (5): 475-486they can also undergo asymmetrical division and differentiation either as stochastic events or in response to environmental cues. Although new experimental evidences indicate that this is can be a reversible process, thus blurring the distinction between CSCs and non-CSCs, the former are considered as the drivers of tumor growth and evolution, and thus a prime target for therapeutic intervention. Of particular importance in prostate cancer, CSCs may constitute the repository population of androgen-insensitive and chemotherapy-resistant tumor cells responsible for castration-resistant and chemotherapy-insensitive tumors, thus their identification and quanti-fication in primary and metastatic neoplasms could play important roles in the management of this disease.
Bladder cancer represents a very important entity in the field of urologic oncology. At the time of diagnosis 70% of them are non muscle-invasive tumors with a very variable risk of recurrence and progression. These patients will require a periodic follow up, at least for 5 years, performing multiple cystoscopies and urine cytologies throughout their lifes. These diagnostic tests are either invasive or have a low sensitivity, a fact that has stimulated the search of non-invasive markers with high sensitivity for the diagnosis of bladder cancer. The great advantage in this neoplasia is the availability of a biologic sample such as urine, which being in close contact with the urothelium collects exfoliated cells, representing a valuable non invasive tool for the diagnosis and follow up of this neoplasias.In this article we try to perform a review of those markers for bladder cancer already marketed and under development, as well as future diagnostic perspectives.
Reliable markers for assessing therapeutic response are needed to select the most effective treatment strategy for bladder cancer patients. We analyzed the role of biomarkers predicting response of non-muscle invasive bladder cancer (NMIBC) on BCG induction, and of non-organ confined muscle invasive bladder cancer (MIBC) on neoadjuvant chemotherapy. A critical, non-structured review of the literature was conducted.Arch. Esp. Urol. 2013; 66 (5): 495-504For assessing BCG therapy outcome, measurement of urinary IL-2 levels seems to be the most potent marker of all the clinical parameters reviewed. Measurements of urinary interleukins IL-8, IL-18, and tumour necrosis factor apoptosis-inducing ligand levels seem promising as well. Immunohistochemical markers (ie, TP53, Ki-67, and Rb) display contradictory results and seem unsuitable. Gene polymorphisms need to be studied more thoroughly before their clinical relevance can be determined.Regarding assessing and predicting response of MIBC to neoadjuvant chemotherapy, a set of potent markers has been studied. However, no conclusive evidence is yet available on their additional value over the established clinicopathological variables.Prospective trials are needed to validate the clinical benefit of molecular markers to predict response to BCG (NMIBC) and neoadjuvant chemotherapy (MIBC) before predictive biomarkers can become part of clinical practice.
Renal cell carcinoma (RCC), themost common type of kidney cancer, is increasing inincidence and is the most lethal genitourinary cancer.Due to the increasing use of abdominal imaging,incidentally detected, asymptomatic small renal masses(SRMs), most of which are RCC, have become themost common presentation of kidney cancer. MostRCC SRMs initially grow slowly or not at all, but othersprogress to advanced and metastatic cancer. Severaldiagnostic and prognostic genomic, transcriptomicand proteomic studies have been completed in RCC,however signatures for SRM progression have not been identified. In the absence of useful factors to distinguishthose tumors requiring treatment for progression fromthose that can be managed by active surveillancealone, most SRMs are treated as RCC with surgery.Currently, the only prognostic factor at diagnosis istumor size. Tumor growth rate also appears to identifypotential progressive tumours. Identifying signatures forprogression and the utilization of needle biopsies will beimportant for SRM patients and will guide therapy
There has been expansion of therapeutic options in the management of metastatic renal cell carcinoma due to a better knowledge of the molecular biology of kidney cancers. There are different tumors grouped under the term renal cell carcinoma, being clear cell cancer the most frequent and accounting for 80% of kidney tumors. Mutations in the Von Hippel-Lindau gene can be identified in up to 80% of sporadic clear cell cancer, linking a genetically inheritable disease where vascular tumors are frequent, with renal cell cancer. Other histologic types present specific alterations in molecular pathways, like c-MET in papillary type I tumors, and Fumarase Hydratase in papillary type II tumors. Identification of the molecular alteration for a specific tumor may offer an opportunity for treatment selection based on biomarkers, and, in the future, for developing an engineering designed genetic treatment.
Cisplatin has been the cornerstone of germ cell testicular tumors therapy since its introduction more tan 30 years ago, and a basic part of the sche-mes given to multiple ovarian, lung, head and neck, and bladder tumors among others. Some tumors pre-sent primary resistance to this drug, others will develop it despite good initial response. In the case of testicular germ cell tumors most of them are very sensitive to this drug but up to 20% of patients with metastatic disease will present resistance, most of them secondary after a very good initial response. Cisplatin acts by binding to DNA to activate genetic damage recognition mechanis-ms and apoptosis through the mitochondrial pathway. Resistance mechanisms to cisplatin have been classiﬁed in those that happen (1) before its binding to DNA and (2) once it binds to DNA. Most advances in their dis-covery have used other neoplasias as models, mainly ovarian and lung tumors. In this review we will describe the biological mechanisms behind resistance to cisplatin from the global perspective but trying to focus in testicu-lar germ cell tumors.
Background : Upper urinary tract urothelial carcinomas (UUT-UCs) account for only 5-10% of urothelial carcinomas and the gold standard treatment is open radical nephroureterectomy. Strong differences exist regarding tumor behaviour between the upper and the lower urinary tract.Objective: To demonstrate how the current knowledge in molecular biology of UUT-UCs is likely to modify the management of these tumours.Acquisition of evidence: A MEDLINE search was performed on UUT-UC using the following terms: urinary tract cancer; urothelial carcinomas; upper urinary tract; molecular markers; renal pelvis; ureter; ureteroscopy; nephroureterectomy; adjuvant treatment; neoadjuvant treatment; recurrence; risk factors and survival.Evidence synthesis: Conservative surgery for low-risk UUT-UCs allows for preservation of the upper urinary renal unit, while sparing the patient the morbidity associated with open surgery. Such surgical strategy might be more appropriate in tumors displaying certain molecular markers: microsatellite instability, E-cadherin, MET, Aurora-A, and Ki-67. These markers could help to identify more candidates to nephron-sparing treatment without compromising the oncologic outcome. Susceptibility means an increase in risk conferred by one or more polymorphisms (allele types) of a given gene or genes, which expose the individual to the genotoxic effects of environmental carcinogens. The variant allele SULT1A1*2 with reduced sulfotransferase activity and the T allele of rs9642880 on chromosome 8q24 enhance the risk of UUT-UCs. If an at-risk genetic profile could be established, it might be possible to prevent urothelial carcinomas in some patients.Conclusions: Surgical practice is gradually moving towards minimally invasive techniques which spare the functional unity of the kidney and urinary tract. The ongoing identification of distinct carcinogenic mechanisms for UUT-UCs might open the way to specific treatments adapted to the molecular pattern of each tumor. The next era might hopefully be that of chemoprevention.