Biochim Biophys Acta Mol Basis Dis
October 2021
Emerging data show a rise in colorectal cancer (CRC) incidence in young men and women that is often chemoresistant. One potential risk factor is an alteration in the microbiome. Here, we investigated the role of TGF-β signaling on the intestinal microbiome and the efficacy of chemotherapy for CRC induced by azoxymethane and dextran sodium sulfate in mice.
View Article and Find Full Text PDFOver 90% of hepatocellular carcinoma (HCC) occurs against a background of chronic liver disease or cirrhosis induced from viral hepatitis to alcohol injury. One third of patients with cirrhosis will develop HCC during their lifetime, with a 3-5% annual incidence. However, little is known about the key mechanisms by which toxins mediate DNA damage in the liver.
View Article and Find Full Text PDFWe present an integromic analysis of gene alterations that modulate transforming growth factor β (TGF-β)-Smad-mediated signaling in 9,125 tumor samples across 33 cancer types in The Cancer Genome Atlas (TCGA). Focusing on genes that encode mediators and regulators of TGF-β signaling, we found at least one genomic alteration (mutation, homozygous deletion, or amplification) in 39% of samples, with highest frequencies in gastrointestinal cancers. We identified mutation hotspots in genes that encode TGF-β ligands (BMP5), receptors (TGFBR2, AVCR2A, and BMPR2), and Smads (SMAD2 and SMAD4).
View Article and Find Full Text PDFColorectal cancer (CRC) accounts for ~9% of all cancers in the Veteran population, a fact which has focused a great deal of the attention of the VA's research and development efforts. A field-based meeting of CRC experts was convened to discuss both challenges and opportunities in precision medicine for CRC. This group, designated as the VA Colorectal Cancer Cell-genomics Consortium (VA4C), discussed advances in CRC biology, biomarkers, and imaging for early detection and prevention.
View Article and Find Full Text PDFCancer stem cells have established mechanisms that contribute to tumor heterogeneity as well as resistance to therapy. Over 40% of hepatocellular carcinomas (HCCs) are considered to be clonal and arise from a stem-like/cancer stem cell. Moreover, HCC is the second leading cause of cancer death worldwide, and an improved understanding of cancer stem cells and targeting these in this cancer are urgently needed.
View Article and Find Full Text PDFUnlabelled: Exposure to genotoxins such as ethanol-derived acetaldehyde leads to DNA damage and liver injury and promotes the development of cancer. We report here a major role for the transforming growth factor β/mothers against decapentaplegic homolog 3 adaptor β2-Spectrin (β2SP, gene Sptbn1) in maintaining genomic stability following alcohol-induced DNA damage. β2SP supports DNA repair through β2SP-dependent activation of Fanconi anemia complementation group D2 (Fancd2), a core component of the Fanconi anemia complex.
View Article and Find Full Text PDFDisruption of the TGF-β pathway is associated with liver fibrosis and suppression of liver tumorigenesis, conditions associated with low Vitamin D (VD) levels. However, potential contributions of VD to liver tumor progression in the context of TGF-β signaling remain unexplored. Our analyses of VD deprivation (VDD) in in vivo models of liver tumor formation revealed striking three-fold increases in tumor burden in Smad3(+/-) mice, with a three-fold increase in TLR7 expression compared to controls.
View Article and Find Full Text PDFMutational processes and signatures that drive early tumorigenesis are centrally important for early cancer prevention. Yet, to date, biomarkers and risk factors for polyps (adenomas) that inordinately and rapidly develop into colon cancer remain poorly defined. Here, we describe surprisingly high mutational profiles through whole-genome sequence (WGS) analysis in 2 of 4 pairs of benign colorectal adenoma tissue samples.
View Article and Find Full Text PDFNon-alcoholic fatty liver disease (NAFLD) is being recognized as an increasingly important contributor to the burden of hepatocellular carcinoma (HCC) worldwide. It is often accompanied by obesity and diabetes mellitus and is believed to be the hepatic representation of the metabolic syndrome. HCC development in NAFLD is multifactorial and complex.
View Article and Find Full Text PDFHereditary cancer syndromes provide powerful insights into dysfunctional signaling pathways that lead to sporadic cancers. Beckwith-Wiedemann syndrome (BWS) is a hereditary human cancer stem cell syndrome currently linked to deregulated imprinting at chromosome 11p15 and uniparental disomy. However, causal molecular defects and genetic models have remained elusive to date in the majority of cases.
View Article and Find Full Text PDFUnlabelled: We have previously demonstrated that 40%-70% of elf(+/-) mice spontaneously develop hepatocellular cancer (HCC) within 15 months, revealing the importance of the transforming growth factor-beta (TGF-beta) signaling pathway in suppressing tumorigenesis in the liver. The current study was carried out to investigate mechanisms by which embryonic liver fodrin (ELF), a crucial Smad3/4 adaptor, suppresses liver tumor formation. Histological analysis of hyperplastic liver tissues from elf(+/-) mice revealed abundant newly formed vascular structures, suggesting aberrant angiogenesis with loss of ELF function.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2008
Cancer stem cells (CSCs) are critical for the initiation, propagation, and treatment resistance of multiple cancers. Yet functional interactions between specific signaling pathways in solid organ "cancer stem cells," such as those of the liver, remain elusive. We report that in regenerating human liver, two to four cells per 30,000-50,000 cells express stem cell proteins Stat3, Oct4, and Nanog, along with the prodifferentiation proteins TGF-beta-receptor type II (TBRII) and embryonic liver fodrin (ELF).
View Article and Find Full Text PDFThe mammalian forebrain subependyma contains neural stem cells and other proliferating progenitor cells. Recent studies have shown the importance of TGF-beta family members and their adaptor proteins in the inhibition of proliferation in the nervous system. Previously, we have demonstrated that TGF-beta induces phosphorylation and association of ELF (embryonic liver fodrin) with Smad3 and Smad4 resulting in nuclear translocation.
View Article and Find Full Text PDFTGF-beta/Smads regulate a wide variety of biological responses through transcriptional regulation of target genes. ELF, a beta-spectrin, plays a key role in the transmission of TGF-beta-mediated transcriptional response through Smads. ELF was originally identified as a key protein involved in endodermal stem/progenitor cells committed to foregut lineage.
View Article and Find Full Text PDFUnlabelled: Modulation of fibrogenesis, epithelial, and mesenchymal cell fates are prominent effects of transforming growth factor-beta (TGF-beta) signaling by Smad proteins. We have previously shown that Smad2 and Smad3 insufficiency leads to a loss of bile ducts. In addition, Smad3/4 activity is mediated by embryonic liver fodrin (ELF), a beta-Spectrin.
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