Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
56 result(s) for "Macias, Rocio I. R."
Sort by:
Drug-Resistant Cholangiocarcinoma Cell Lines for Therapeutic Evaluation of Novel Drugs
The pharmacological treatment of cholangiocarcinoma (CCA) is often hampered by tumor resistance. Improving our understanding of this issue is crucial for developing strategies that can overcome drug refractoriness. We have established and characterized two novel human cell sublines derived from extrahepatic CCA EGI-1 cells that are resistant to cisplatin and 5-fluorouracil (5-FU). Migration and proliferation were analyzed using holographic microscopy. The expression of genes involved in drug uptake and efflux was determined by RT-qPCR. Cross-resistance to commonly used antitumor drugs was assayed using the MTT test. EGI-1 sublines resistant to cisplatin (CR) or 5-FU (FR) exhibited more than a three-fold increase in resistance to cisplatin and 5-FU, respectively, and showed reduced proliferation, migration, and colony-formation rates, along with an altered cell cycle compared to wild-type cells, while retaining tumorigenic capacity. The analysis of the transportome showed downregulation of uptake transporters and upregulation of the export pumps MRP3/4. EGI-1 cells with acquired resistance to 5-FU demonstrated cross-resistance to irinotecan and gemcitabine, while cisplatin-resistant cells showed decreased sensitivity to 5-FU and platinum derivatives. These resistant cell lines offer valuable models for investigating the molecular basis of chemoresistance in CCA, providing a robust platform for the development and evaluation of novel therapeutic strategies.
Lacking Immunotherapy Biomarkers for Biliary Tract Cancer: A Comprehensive Systematic Literature Review and Meta-Analysis
Background: Immunotherapy has recently been incorporated into the spectrum of biliary tract cancer (BTC) treatment. The identification of predictive response biomarkers is essential in order to identify those patients who may benefit most from this novel treatment option. Here, we propose a systematic literature review and a meta-analysis of PD-1, PD-L1, and other immune-related biomarker expression levels in patients with BTC. Methods: Prisma guidelines were followed for this systematic review and meta-analysis. Eligible studies were searched on PubMed. Studies published between 2017 and 2022, reporting data on PD-1/PD-L1 expression and other immune-related biomarkers in patients with BTC, were considered eligible. Results: A total of 61 eligible studies were identified. Despite the great heterogeneity between 39 studies reporting data on PD-L1 expression, we found a mean PD-L1 expression percentage (by choosing the lowest cut-off per study) of 25.6% (95% CI 21.0 to 30.3) in BTCs. The mean expression percentages of PD-L1 were 27.3%, 21.3%, and 27.4% in intrahepatic cholangiocarcinomas (iCCAs—15 studies), perihilar–distal CCAs (p/dCCAs—7 studies), and gallbladder cancer (GBC—5 studies), respectively. Furthermore, 4.6% (95% CI 2.38 to 6.97) and 2.5% (95% CI 1.75 to 3.34) of BTCs could be classified as TMB-H and MSI/MMRd tumors, respectively. Conclusion: From our analysis, PD-L1 expression was found to occur approximately in 26% of BTC patients, with minimal differences based on anatomical location. TMB-H and MSI molecular phenotypes occurred less frequently. We still lack a reliable biomarker, especially in patients with mismatch-proficient tumors, and we must need to make an effort to conceive new prospective biomarker discovery studies.
Cholangiocarcinoma 2020: the next horizon in mechanisms and management
Cholangiocarcinoma (CCA) includes a cluster of highly heterogeneous biliary malignant tumours that can arise at any point of the biliary tree. Their incidence is increasing globally, currently accounting for ~15% of all primary liver cancers and ~3% of gastrointestinal malignancies. The silent presentation of these tumours combined with their highly aggressive nature and refractoriness to chemotherapy contribute to their alarming mortality, representing ~2% of all cancer-related deaths worldwide yearly. The current diagnosis of CCA by non-invasive approaches is not accurate enough, and histological confirmation is necessary. Furthermore, the high heterogeneity of CCAs at the genomic, epigenetic and molecular levels severely compromises the efficacy of the available therapies. In the past decade, increasing efforts have been made to understand the complexity of these tumours and to develop new diagnostic tools and therapies that might help to improve patient outcomes. In this expert Consensus Statement, which is endorsed by the European Network for the Study of Cholangiocarcinoma, we aim to summarize and critically discuss the latest advances in CCA, mostly focusing on classification, cells of origin, genetic and epigenetic abnormalities, molecular alterations, biomarker discovery and treatments. Furthermore, the horizon of CCA for the next decade from 2020 onwards is highlighted.Cholangiocarcinoma (CCA) comprises heterogeneous biliary malignant tumours, and their incidence is increasing worldwide. This expert Consensus Statement, endorsed by the ENS-CCA, summarizes the latest advances in CCA, including classification, genetics and treatment, and provides recommendations for CCA management and priorities across basic, translational and clinical research.
Impact of Aberrant β-Catenin Pathway on Cholangiocarcinoma Heterogeneity
The poor prognosis of most cases of advanced cholangiocarcinoma (CCA) constitutes a severe problem in modern oncology, which is aggravated by the fact that the incidence of this liver cancer is increasing worldwide and is often diagnosed late, when surgical removal is not feasible. The difficulty of dealing with this deadly tumor is augmented by the heterogeneity of CCA subtypes and the complexity of mechanisms involved in enhanced proliferation, apoptosis avoidance, chemoresistance, invasiveness, and metastasis that characterize CCA. Among the regulatory processes implicated in developing these malignant traits, the Wnt/β-catenin pathway plays a pivotal role. Alteration of β-catenin expression and subcellular localization has been associated with worse outcomes in some CCA subtypes. This heterogeneity, which also affects cellular and in vivo models commonly used to study CCA biology and anticancer drug development, must be taken into account for CCA investigation to more accurately extrapolate basic laboratory research to the clinical situation. A better understanding of the altered Wnt/β-catenin pathway in relationship with the heterogeneous forms of CCA is mandatory for developing novel diagnostic tools and therapeutic strategies for patients suffering from this lethal disease.
Molecular Bases of Drug Resistance in Hepatocellular Carcinoma
The poor outcome of patients with non-surgically removable advanced hepatocellular carcinoma (HCC), the most frequent type of primary liver cancer, is mainly due to the high refractoriness of this aggressive tumor to classical chemotherapy. Novel pharmacological approaches based on the use of inhibitors of tyrosine kinases (TKIs), mainly sorafenib and regorafenib, have provided only a modest prolongation of the overall survival in these HCC patients. The present review is an update of the available information regarding our understanding of the molecular bases of mechanisms of chemoresistance (MOC) with a significant impact on the response of HCC to existing pharmacological tools, which include classical chemotherapeutic agents, TKIs and novel immune-sensitizing strategies. Many of the more than one hundred genes involved in seven MOC have been identified as potential biomarkers to predict the failure of treatment, as well as druggable targets to develop novel strategies aimed at increasing the sensitivity of HCC to pharmacological treatments.
The role of reduced intracellular concentrations of active drugs in the lack of response to anticancer chemotherapy
A major difficulty in the treatment of cancers is the poor response of many tumors to pharmacological regimens. This situation can be accounted for by the existence of a variety of complex mechanisms of chemoresistance (MOCs), leading to reduced intracellular concentrations of active agents, changes in the molecular targets of the drugs, enhanced repair of drug-induced modifications in macromolecules, stimulation of anti-apoptotic mechanisms, and inhibition of pro-apoptotic mechanisms. The present review focuses on alterations in the expression and appearance of the genetic variants that affect the genes involved in reducing the amount of active agents inside tumor cells. These alterations can occur through two mechanisms: either by lowering uptake or enhancing efflux (so-called MOC-1a and MOC-1b, respectively), or by decreasing the activation of prodrugs or enhancing inactivation of active agents through their biotransformation (MOC-2). The development of chemosensitizers that are useful in implementing the pharmacological manipulation of these processes constitutes a challenge to modern pharmacology. Nevertheless, the important physiological roles of the most relevant genes involved in MOC-1a, MOC-1b, and MOC-2 make it difficult to prevent the side effects of chemosensitizers. A more attainable goal in this area of pharmacological enquiry is the identification of proteomic profiles that will permit oncologists to accurately predict a lack of response to a given regimen, which would be useful for adapting treatment to the personal situation of each patient.
Role of macrophages in bile acid-induced inflammatory response of fetal lung during maternal cholestasis
Infant respiratory distress syndrome (iRDS) in babies born from women with intrahepatic cholestasis of pregnancy (ICP) has been associated with intrauterine exposure to high bile acid levels. Here, we have investigated the role of macrophages in hypercholanemia-induced changes in maternal and fetal lung. Obstructive cholestasis in pregnant rats (OCP) was maintained from day 14 of gestation to term. Gene expression was determined by RT-QPCR, Western blot, and immunofluorescence. The maternal-fetal bile acid pool was radiolabelled using [ 3 H]-taurocholate. OCP resulted in increased bile acids in maternal and fetal organs, including lungs. This was accompanied by structural changes in lung tissue, more marked in fetuses (peribronchial edema, collapse of alveolar spaces and deposits of hyaline material in the alveolar lumen), and infiltration of lung tissue by inflammatory cells. The abundance of macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) was also increased in OCP group. Phospholipase A2-IIA (PLA2), the key enzyme in surfactant degradation, was mainly immunodetected in macrophages, which also expressed the bile acid receptor TGR5. The overall expression of PLA2 was markedly enhanced in maternal and fetal lungs of OCP group and in control maternal BALF cells incubated with bile acids. In neonates born from OCP mothers, the enhanced expression of erythropoietin suggested the presence of hypoxia due to iRDS. In conclusion, these results indicate that the accumulation of bile acids due to maternal cholestasis triggers an inflammatory response in the maternal and fetal lungs together with enhanced macrophage-associated PLA2 expression, which may play an important role in iRDS development. Key Messages Maternal cholestasis causes respiratory distress syndrome in rat neonates. Cholestasis in pregnant rats causes bile acid accumulation in the fetal lung. This induces lung macrophages infiltration and inflammatory response. Alveolar macrophages co-express phospholipase A2-IIA and TGR5, but not FXR. Bile acid accumulation stimulates phospholipase A2-IIA, but not TGR5, expression.
Criteria for preclinical models of cholangiocarcinoma: scientific and medical relevance
Cholangiocarcinoma (CCA) is a rare malignancy that develops at any point along the biliary tree. CCA has a poor prognosis, its clinical management remains challenging, and effective treatments are lacking. Therefore, preclinical research is of pivotal importance and necessary to acquire a deeper understanding of CCA and improve therapeutic outcomes. Preclinical research involves developing and managing complementary experimental models, from in vitro assays using primary cells or cell lines cultured in 2D or 3D to in vivo models with engrafted material, chemically induced CCA or genetically engineered models. All are valuable tools with well-defined advantages and limitations. The choice of a preclinical model is guided by the question(s) to be addressed; ideally, results should be recapitulated in independent approaches. In this Consensus Statement, a task force of 45 experts in CCA molecular and cellular biology and clinicians, including pathologists, from ten countries provides recommendations on the minimal criteria for preclinical models to provide a uniform approach. These recommendations are based on two rounds of questionnaires completed by 35 (first round) and 45 (second round) experts to reach a consensus with 13 statements. An agreement was defined when at least 90% of the participants voting anonymously agreed with a statement. The ultimate goal was to transfer basic laboratory research to the clinics through increased disease understanding and to develop clinical biomarkers and innovative therapies for patients with CCA.Preclinical research is required to improve our understanding of cholangiocarcinoma (CCA). In this Consensus Statement, a task force of experts provides recommendations on the criteria for preclinical models of CCA to increase disease understanding and help to develop novel therapeutic approaches.
Learning from Other Tumors: Pathways for Progress and Overcoming Challenges in Cholangiocarcinoma
Cholangiocarcinoma (CCA) is a group of complex and heterogeneous tumors originating from the epithelial cells of bile ducts that can occur in intrahepatic, perihilar, or distal localizations [...].Cholangiocarcinoma (CCA) is a group of complex and heterogeneous tumors originating from the epithelial cells of bile ducts that can occur in intrahepatic, perihilar, or distal localizations [...].
Expression of Chemoresistance-Associated ABC Proteins in Hepatobiliary, Pancreatic and Gastrointestinal Cancers
Hepatobiliary, pancreatic, and gastrointestinal cancers account for 36% of the ten million deaths caused by cancer worldwide every year. The two main reasons for this high mortality are their late diagnosis and their high refractoriness to pharmacological treatments, regardless of whether these are based on classical chemotherapeutic agents, targeted drugs, or newer immunomodulators. Mechanisms of chemoresistance (MOC) defining the multidrug resistance (MDR) phenotype of each tumor depend on the synergic function of proteins encoded by more than one hundred genes classified into seven groups (MOC1-7). Among them, the efflux of active agents from cancer cells across the plasma membrane caused by members of the superfamily of ATP-binding cassette (ABC) proteins (MOC-1b) plays a crucial role in determining tumor MDR. Although seven families of human ABC proteins are known, only a few pumps (mainly MDR1, MRP1-6, and BCRP) have been associated with reducing drug content and hence inducing chemoresistance in hepatobiliary, pancreatic, and gastrointestinal cancer cells. The present descriptive review, which compiles the updated information on the expression of these ABC proteins, will be helpful because there is still some confusion on the actual relevance of these pumps in response to pharmacological regimens currently used in treating these cancers. Moreover, we aim to define the MOC pattern on a tumor-by-tumor basis, even in a dynamic way, because it can vary during tumor progression and in response to chemotherapy. This information is indispensable for developing novel strategies for sensitization.