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Asian Pacific Journal of Cancer... Jan 2024Breast cancer is one of the most common cancers in the world and leading cause of cancer-related death among women. Several studies indicated that Arg188His (rs3218536)... (Meta-Analysis)
Meta-Analysis
Breast cancer is one of the most common cancers in the world and leading cause of cancer-related death among women. Several studies indicated that Arg188His (rs3218536) polymorphism of X-ray repair cross-complementing 2 (XRCC2) may be associated with breast cancer risk. However, this association remains ambiguous. Thus, we performed a meta-analysis to provide more precise conclusion on this issue. A comprehensive search in PubMed, Google Scholar and ISI Web of Science was performed to select all relevant studies. Odds ratios (OR) with corresponding 95% confidence intervals (CI) were applied to assess the strength of the relationships. A total of 17 studies with 5694 breast cancer cases and 6450 healthy subjects were identified. The pooled data revealed that XRCC2 Arg188His polymorphism was marginally with susceptibility to breast cancer globally under the heterozygote contrast (OR = 0.929, 95% CI = 0.873-0.987, p=0.018). Moreover, subgroup analysis by ethnicity revealed that this polymorphism was associated with breast cancer risk among Caucasians. On the whole, the present study demonstrates that the XRCC2 Arg188His polymorphism may contribute to an increased risk of breast cancer.
Topics: Female; Humans; Breast Neoplasms; Case-Control Studies; DNA-Binding Proteins; Genetic Predisposition to Disease; Polymorphism, Single Nucleotide; X-Rays
PubMed: 38285766
DOI: 10.31557/APJCP.2024.25.1.43 -
Frontiers in Endocrinology 2024Well-differentiated pancreatic neuroendocrine tumors (PNETs) can be non-functional or functional, e.g. insulinoma and glucagonoma. The majority of PNETs are sporadic,... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Well-differentiated pancreatic neuroendocrine tumors (PNETs) can be non-functional or functional, e.g. insulinoma and glucagonoma. The majority of PNETs are sporadic, but PNETs also occur in hereditary syndromes, primarily multiple endocrine neoplasia type 1 (MEN1). The Knudson hypothesis stated a second, somatic hit in as the cause of PNETs of MEN1 syndrome. In the recent years, reports on genetic somatic events in both sporadic and hereditary PNETs have emerged, providing a basis for a more detailed molecular understanding of the pathophysiology. In this systematic review and meta-analysis, we made a collation and statistical analysis of aggregated frequent genetic alterations and potential driver events in human grade G1/G2 PNETs.
METHODS
A systematic search was performed in concordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) reporting guidelines of 2020. A search in Pubmed for published studies using whole exome, whole genome, or targeted gene panel (+400 genes) sequencing of human G1/G2 PNETs was conducted at the 25 of September 2023. Fourteen datasets from published studies were included with data on 221 patients and 225 G1/G2 PNETs, which were divided into sporadic tumors, and hereditary tumors with pre-disposing germline variants, and tumors with unknown germline status. Further, non-functioning and functioning PNETs were distinguished into two groups for pathway evaluation. The collated genetical analyses were conducted using the 'maftools' R-package.
RESULTS
Sporadic PNETs accounted 72.0% (162/225), hereditary PNETs 13.3% (30/225), unknown germline status 14.7% (33/225). The most frequently altered gene was , with somatic variants and copy number variations in overall 42% (95/225); hereditary PNETs (germline variations in , , , , , , and/or ) 57% (16/30); sporadic PNETs 36% (58/162); unknown germline status 64% (21/33). The point mutations/indels were distributed throughout . Overall, (16%, 37/225) and -variants (12%, 27/225) were also abundant with missense mutations clustered in mutational hotspots associated with histone binding, and translocase activity, respectively. mutations occurred more frequently in PNETs with mutations, p<0.05. While functioning PNETs shared few variated genes, non-functioning PNETs had more recurrent variations in genes associated with the Phosphoinositide 3-kinase, Wnt, NOTCH, and Receptor Tyrosine Kinase-Ras signaling onco-pathways.
DISCUSSION
The somatic genetic alterations in G1/G2 PNETs are diverse, but with distinct differences between sporadic vs. hereditary, and functional vs. non-functional PNETs. Increased understanding of the genetic alterations may lead to identification of more drivers and driver hotspots in the tumorigenesis in well-differentiated PNETs, potentially giving a basis for the identification of new drug targets. (Funded by Novo Nordisk Foundation, grant number NNF19OC0057915).
Topics: Humans; Pancreatic Neoplasms; Neuroendocrine Tumors; Sequence Analysis, DNA; Mutation
PubMed: 38868744
DOI: 10.3389/fendo.2024.1351624 -
World Journal of Stem Cells May 2024Gliomas pose a significant challenge to effective treatment despite advancements in chemotherapy and radiotherapy. Glioma stem cells (GSCs), a subset within tumors,...
BACKGROUND
Gliomas pose a significant challenge to effective treatment despite advancements in chemotherapy and radiotherapy. Glioma stem cells (GSCs), a subset within tumors, contribute to resistance, tumor heterogeneity, and plasticity. Recent studies reveal GSCs' role in therapeutic resistance, driven by DNA repair mechanisms and dynamic transitions between cellular states. Resistance mechanisms can involve different cellular pathways, most of which have been recently reported in the literature. Despite progress, targeted therapeutic approaches lack consensus due to GSCs' high plasticity.
AIM
To analyze targeted therapies against GSC-mediated resistance to radio- and chemotherapy in gliomas, focusing on underlying mechanisms.
METHODS
A systematic search was conducted across major medical databases (PubMed, Embase, and Cochrane Library) up to September 30, 2023. The search strategy utilized relevant Medical Subject Heading terms and keywords related to including "glioma stem cells", "radiotherapy", "chemotherapy", "resistance", and "targeted therapies". Studies included in this review were publications focusing on targeted therapies against the molecular mechanism of GSC-mediated resistance to radiotherapy resistance (RTR).
RESULTS
In a comprehensive review of 66 studies on stem cell therapies for SCI, 452 papers were initially identified, with 203 chosen for full-text analysis. Among them, 201 were deemed eligible after excluding 168 for various reasons. The temporal breakdown of studies illustrates this trend: 2005-2010 (33.3%), 2011-2015 (36.4%), and 2016-2022 (30.3%). Key GSC models, particularly U87 (33.3%), U251 (15.2%), and T98G (15.2%), emerge as significant in research, reflecting their representativeness of glioma characteristics. Pathway analysis indicates a focus on phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (mTOR) (27.3%) and Notch (12.1%) pathways, suggesting their crucial roles in resistance development. Targeted molecules with mTOR (18.2%), CHK1/2 (15.2%), and ATP binding cassette G2 (12.1%) as frequent targets underscore their importance in overcoming GSC-mediated resistance. Various therapeutic agents, notably RNA inhibitor/short hairpin RNA (27.3%), inhibitors ( LY294002, NVP-BEZ235) (24.2%), and monoclonal antibodies ( cetuximab) (9.1%), demonstrate versatility in targeted therapies. among 20 studies (60.6%), the most common effect on the chemotherapy resistance response is a reduction in temozolomide resistance (51.5%), followed by reductions in carmustine resistance (9.1%) and doxorubicin resistance (3.0%), while resistance to RTR is reduced in 42.4% of studies.
CONCLUSION
GSCs play a complex role in mediating radioresistance and chemoresistance, emphasizing the necessity for precision therapies that consider the heterogeneity within the GSC population and the dynamic tumor microenvironment to enhance outcomes for glioblastoma patients.
PubMed: 38817336
DOI: 10.4252/wjsc.v16.i5.604