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A highlight on Sonic hedgehog pathway
by
Carballo, Gabriela Basile
,
Spohr, Tania Cristina Leite de Sampaio e
,
de Lopes, Giselle Pinto Farias
in
Analysis
,
Antineoplastic Agents - therapeutic use
,
Biomedical and Life Sciences
2018
Hedgehog (Hh) signaling pathway plays an essential role during vertebrate embryonic development and tumorigenesis. It is already known that Sonic hedgehog (Shh) pathway is important for the evolution of radio and chemo-resistance of several types of tumors. Most of the brain tumors are resistant to chemotherapeutic drugs, consequently, they have a poor prognosis. So, a better knowledge of the Shh pathway opens an opportunity for targeted therapies against brain tumors considering a multi-factorial molecular overview. Therefore, emerging studies are being conducted in order to find new inhibitors for Shh signaling pathway, which could be safely used in clinical trials. Shh can signal through a canonical and non-canonical way, and it also has important points of interaction with other pathways during brain tumorigenesis. So, a better knowledge of Shh signaling pathway opens an avenue of possibilities for the treatment of not only for brain tumors but also for other types of cancers. In this review, we will also highlight some clinical trials that use the Shh pathway as a target for treating brain cancer.
Journal Article
Signal Transduction Pathways of EMT Induced by TGF-β, SHH, and WNT and Their Crosstalks
2016
Epithelial-to-mesenchymal transition (EMT) is a key step in development, wound healing, and cancer development. It involves cooperation of signaling pathways, such as transformation growth factor-β (TGF-β), Sonic Hedgehog (SHH), and WNT pathways. These signaling pathways crosstalk to each other and converge to key transcription factors (e.g., SNAIL1) to initialize and maintain the process of EMT. The functional roles of multi-signaling pathway crosstalks in EMT are sophisticated and, thus, remain to be explored. In this review, we focused on three major signal transduction pathways that promote or regulate EMT in carcinoma. We discussed the network structures, and provided a brief overview of the current therapy strategies and drug development targeted to these three signal transduction pathways. Finally, we highlighted systems biology approaches that can accelerate the process of deconstructing complex networks and drug discovery.
Journal Article
Molecular Targeted Therapies: Time for a Paradigm Shift in Medulloblastoma Treatment?
by
Gatto, Lidia
,
Brandes, Alba Ariela
,
Franceschi, Enrico
in
Adults
,
Chemotherapy
,
Clinical trials
2022
Medulloblastoma is a rare malignancy of the posterior cranial fossa. Although until now considered a single disease, according to the current WHO classification, it is a heterogeneous tumor that comprises multiple molecularly defined subgroups, with distinct gene expression profiles, pathogenetic driver alterations, clinical behaviors and age at onset. Adult medulloblastoma, in particular, is considered a rarer “orphan” entity in neuro-oncology practice because while treatments have progressively evolved for the pediatric population, no practice-changing prospective, randomized clinical trials have been performed in adults. In this scenario, the toughest challenge is to transfer the advances in cancer genomics into new molecularly targeted therapeutics, to improve the prognosis of this neoplasm and the treatment-related toxicities. Herein, we focus on the recent advances in targeted therapy of medulloblastoma based on the new and deeper knowledge of disease biology.
Journal Article
Adult Medulloblastoma: Updates on Current Management and Future Perspectives
by
Gatto, Lidia
,
Franceschi, Enrico
,
Pajtler, Kristian W.
in
Adults
,
Central nervous system
,
Chemotherapy
2022
Medulloblastoma (MB) is a malignant embryonal tumor of the posterior fossa belonging to the family of primitive neuro-ectodermic tumors (PNET). MB generally occurs in pediatric age, but in 14–30% of cases, it affects the adults, mostly below the age of 40, with an incidence of 0.6 per million per year, representing about 0.4–1% of tumors of the nervous system in adults. Unlike pediatric MB, robust prospective trials are scarce for the post-puberal population, due to the low incidence of MB in adolescent and young adults. Thus, current MB treatments for older patients are largely extrapolated from the pediatric experience, but the transferability and applicability of these paradigms to adults remain an open question. Adult MB is distinct from MB in children from a molecular and clinical perspective. Here, we review the management of adult MB, reporting the recent published literature focusing on the effectiveness of upfront chemotherapy, the development of targeted therapies, and the potential role of a reduced dose of radiotherapy in treating this disease.
Journal Article
Molecular Stratification of Medulloblastoma: Clinical Outcomes and Therapeutic Interventions
by
RONECKER, JENNIFER S.
,
MOHAN, AVINASH L.
,
JHANWAR-UNIYAL, MEENA
in
Brain cancer
,
Cerebellar Neoplasms - genetics
,
Cerebellar Neoplasms - therapy
2022
Medulloblastoma (MB) is the most common malignant pediatric posterior fossa tumor. Recent genetic, epigenetic, and transcriptomic analyses have classified MB into three subgroups, Wingless Type (WNT), Sonic Hedgehog (SHH), and non-WNT/non-SHH (originally termed Group 3 and Group 4), with discrete patient profiles and prognoses. WNT is the least common subgroup with the best prognosis, characterized by nuclear β-catenin expression, mutations in Catenin beta-1 (CTNNB1), and chromosome 6 monosomy. SHH tumors contain mutations and alterations in GLI1, GLI2, SUFU, and PTCH1 genes, which constitutively activate the SHH pathway. Originally, the presence of TP53 gene alterations and/or MYC amplifications was considered the most reliable prognostic factor. However, recent molecular analyses have subdivided SHH MB into several subtypes with distinct characteristics such as age, TP53 mutation, MYC amplification, presence of metastases, TERT promoter alterations, PTEN loss, and other chromosomal alterations as well as SHH pathway-related gene mutations. The third non-WNT/non-SHH MB (Group3/4) subgroup is genetically highly heterogeneous and displays several molecular patterns, including MYC and OTX2 amplification, GFI1B activation, KBTBD4 mutation, GFI1 rearrangement, PRDM6 enhancer hijacking, KDM6A mutation, LCA histology, chromosome 10 loss, isochromosome 17q, SNCAIP duplication, and CDK6 amplification. However, based on molecular profiling and methylation patterns, additional non-WNT/non-SHH MB subtypes have been described. Recent WHO (2021) guidelines stratified MB into four molecular subgroups with four and eight further subgroups for SHH and non-WNT/non-SHH MB, respectively. In this review, we discuss advancements in genetics, epigenetics, and transcriptomics for better characterization, prognostication, and treatment of MB using precision medicine.
Journal Article
TERT promoter mutations are highly recurrent in SHH subgroup medulloblastoma
2013
Telomerase reverse transcriptase
(
TERT
) promoter mutations were recently shown to drive telomerase activity in various cancer types, including medulloblastoma. However, the clinical and biological implications of
TERT
mutations in medulloblastoma have not been described. Hence, we sought to describe these mutations and their impact in a subgroup-specific manner. We analyzed the
TERT
promoter by direct sequencing and genotyping in 466 medulloblastomas. The mutational distributions were determined according to subgroup affiliation, demographics, and clinical, prognostic, and molecular features. Integrated genomics approaches were used to identify specific somatic copy number alterations in
TERT
promoter-mutated and wild-type tumors. Overall,
TERT
promoter mutations were identified in 21 % of medulloblastomas. Strikingly, the highest frequencies of
TERT
mutations were observed in SHH (83 %; 55/66) and WNT (31 %; 4/13) medulloblastomas derived from adult patients. Group 3 and Group 4 harbored this alteration in <5 % of cases and showed no association with increased patient age. The prognostic implications of these mutations were highly subgroup-specific.
TERT
mutations identified a subset with good and poor prognosis in SHH and Group 4 tumors, respectively. Monosomy 6 was mostly restricted to WNT tumors without
TERT
mutations. Hallmark SHH focal copy number aberrations and chromosome 10q deletion were mutually exclusive with
TERT
mutations within SHH tumors.
TERT
promoter mutations are the most common recurrent somatic point mutation in medulloblastoma, and are very highly enriched in adult SHH and WNT tumors.
TERT
mutations define a subset of SHH medulloblastoma with distinct demographics, cytogenetics, and outcomes.
Journal Article
Risk stratification of childhood medulloblastoma in the molecular era: the current consensus
by
André, Nicolas
,
Doz, Francois
,
Dufour, Christelle
in
Adolescent
,
Biomarkers
,
Biomarkers, Tumor - genetics
2016
Historical risk stratification criteria for medulloblastoma rely primarily on clinicopathological variables pertaining to age, presence of metastases, extent of resection, histological subtypes and in some instances individual genetic aberrations such as
MYC
and
MYCN
amplification. In 2010, an international panel of experts established consensus defining four main subgroups of medulloblastoma (WNT, SHH, Group 3 and Group 4) delineated by transcriptional profiling. This has led to the current generation of biomarker-driven clinical trials assigning WNT tumors to a favorable prognosis group in addition to clinicopathological criteria including
MYC
and
MYCN
gene amplifications. However, outcome prediction of non-WNT subgroups is a challenge due to inconsistent survival reports. In 2015, a consensus conference was convened in Heidelberg with the objective to further refine the risk stratification in the context of subgroups and agree on a definition of risk groups of non-infant, childhood medulloblastoma (ages 3–17). Published and unpublished data over the past 5 years were reviewed, and a consensus was reached regarding the level of evidence for currently available biomarkers. The following risk groups were defined based on current survival rates: low risk (>90 % survival), average (standard) risk (75–90 % survival), high risk (50–75 % survival) and very high risk (<50 % survival) disease. The WNT subgroup and non-metastatic Group 4 tumors with whole chromosome 11 loss or whole chromosome 17 gain were recognized as low-risk tumors that may qualify for reduced therapy. High-risk strata were defined as patients with metastatic SHH or Group 4 tumors, or
MYCN
-amplified SHH medulloblastomas. Very high-risk patients are Group 3 with metastases or SHH with
TP53
mutation. In addition, a number of consensus points were reached that should be standardized across future clinical trials. Although we anticipate new data will emerge from currently ongoing and recently completed clinical trials, this consensus can serve as an outline for prioritization of certain molecular subsets of tumors to define and validate risk groups as a basis for future clinical trials.
Journal Article
Prognostic value of microRNA-125a expression status in molecular groups of pediatric medulloblastoma
by
Sharafeldin, Hend A.
,
Hamam, Soheir M.
,
Nassra, Rasha A.
in
Biomarkers, Tumor - genetics
,
Biomarkers, Tumor - metabolism
,
Brain Neoplasms
2023
Purpose
Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Current treatment allows decent survival rates but often with life-long morbidity. Molecular classification provides a base for novel therapeutic approaches. However, these groups are heterogeneous. MicroRNA-125a has a tumor suppressor function. It is downregulated in several tumors. The expression of microRNA-125a in MB patients remains unclear. Therefore, this study was designed to evaluate the expression of microRNA-125a in molecular groups of pediatric MB patients in Egyptian population and its clinical significance.
Methods
Formalin-fixed, paraffin-embedded tissue blocks from 50 pediatric MB patients were retrospectively collected. Immunohistochemistry for β-catenin, GAB1, YAP1, and p53 was done for molecular classification. MicroRNA-125a expression analysis was done using qRT-PCR. Follow-up data were obtained from patients’ records.
Results
MicroRNA-125a expression was significantly lower in MB patients showing large cell/anaplastic (LC/A) histology and in the non-WNT/non-SHH group. Lower levels of microRNA-125a showed a tendency toward poor survival rates; however, difference was not significant. Infants and larger preoperative tumor size were significantly associated with lower survival rates. On a multivariate analysis, preoperative tumor size was an independent prognostic factor.
Conclusion
MicroRNA-125a expression was significantly lower in categories of pediatric MB patients with worse prognosis namely LC/A histology and the non-WNT/non-SHH group suggesting a pathogenetic role. MicroRNA-125a expression could represent a promising prognostic factor and a potential therapeutic target in the non-WNT/non-SHH group which represents the most common and the most heterogeneous group of pediatric MBs coupled with the highest rates of disseminated disease. Preoperative tumor size represents an independent prognostic factor.
Journal Article
Association of cardiometabolic index with all-cause and cardiovascular mortality among middle-aged and elderly populations
2025
The Cardiometabolic Index (CMI) is a well-recognized risk factor for a range of cardiovascular diseases and diabetes mellitus. However, the population-level characteristics of CMI and its potential association with mortality risk among individuals over 40 years of age have not been investigated. This study aims to assess the association between CMI and both all-cause and cardiovascular mortality among the middle-aged and elderly population. This cohort study utilized data from 3752 American adults extracted from the Sleep Heart Health Study (SHHS) conducted from 1995 to 2011. The CMI was calculated using the waist-to-height ratio, triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C). The primary outcomes were all-cause mortality and cardiovascular mortality, with mortality data sourced from the SHHS Linked Mortality File. Kaplan-Meier survival curves and Cox regression models were employed to assess the prognostic value of the CMI. Among the 3752 American adults, the mean (SD) age was 65.9 (10.1) years, and 1969 (52.5%) were women. The mean (SD) CMI was 0.914 ± 0.939. Over an average follow-up period of 10.7 years, there were 926 all-cause deaths and 289 cardiovascular deaths. Participants were categorized into three groups based on their CMI levels: tertile (T) 1: 0.315 ± 0.0994; T2: 0.680 ± 0.128; T3: 1.75 ± 1.23. Multivariate Cox proportional hazards analysis showed that elevated CMI was significantly associated with all-cause mortality (HR 1.215, 95% CI 1.032–1.43 for T2; HR 1.309, 95% CI 1.115–1.537 for T3) and cardiovascular mortality (HR 1.305, 95% CI 0.971–1.755 for T2; HR 1.457, 95% CI 1.091–1.947 for T3). After adjusting for confounders, elevated CMI remained significantly associated with all-cause mortality (HR 1.315, 95% CI 1.098–1.575 for T3) and cardiovascular mortality (HR 1.562, 95% CI 1.124–2.17 for T3). Kaplan-Meier survival curves indicated significantly worse outcomes for participants in the higher CMI tertiles for both all-cause mortality (log-rank
p
= 0.0035) and cardiovascular mortality (log-rank
p
= 0.035). This national cohort study found that CMI is significantly associated with both all-cause and cardiovascular mortality among American adults aged over 40. These findings suggest that CMI could be a valuable tool for identifying high-risk individuals, thereby aiding in the implementation of targeted preventive strategies.
Journal Article
Molecular subgroups of medulloblastoma: the current consensus
by
Remke, Marc
,
Cho, Yoon-Jae
,
Eberhart, Charles G.
in
Biology
,
Cancer research
,
Cerebellar Neoplasms - classification
2012
Medulloblastoma, a small blue cell malignancy of the cerebellum, is a major cause of morbidity and mortality in pediatric oncology. Current mechanisms for clinical prognostication and stratification include clinical factors (age, presence of metastases, and extent of resection) as well as histological subgrouping (classic, desmoplastic, and large cell/anaplastic histology). Transcriptional profiling studies of medulloblastoma cohorts from several research groups around the globe have suggested the existence of multiple distinct molecular subgroups that differ in their demographics, transcriptomes, somatic genetic events, and clinical outcomes. Variations in the number, composition, and nature of the subgroups between studies brought about a consensus conference in Boston in the fall of 2010. Discussants at the conference came to a consensus that the evidence supported the existence of four main subgroups of medulloblastoma (Wnt, Shh, Group 3, and Group 4). Participants outlined the demographic, transcriptional, genetic, and clinical differences between the four subgroups. While it is anticipated that the molecular classification of medulloblastoma will continue to evolve and diversify in the future as larger cohorts are studied at greater depth, herein we outline the current consensus nomenclature, and the differences between the medulloblastoma subgroups.
Journal Article