Colorectal cancer is the third most common cancer and a major cause of cancer-related deaths. Early detection of colonic lesions can reduce the incidence and mortality of colorectal cancer. ...Colonoscopy is the screening test for colorectal cancer with the highest efficacy, but its acceptance in the general public is rather low. To identify suitable tumor-derived markers that could detect colorectal cancer in blood samples, we analyzed the methylation status of a panel of genes in sera of affected patients.
Using methylation-specific quantitative PCR, we analyzed the methylation of ten marker genes in sera of healthy individuals and patients with colorectal cancer.
Only HLTF, HPP1/TPEF, and NEUROG1 DNA methylation was detectable in at least 50% of patients with colorectal cancers. Whereas HLTF and HPP1/TPEF preferentially detected advanced and metastasized colorectal cancers, NEUROG1 methylation was detectable in UICC stages I-IV at a similar rate. Compared with other methylation markers, such as ALX4, SEPT9, and vimentin, NEUROG1 shows a higher sensitivity for colorectal cancer at UICC stages I and II. At a specificity of 91%, NEUROG1 reached a sensitivity of 61% (confidence interval, 50.4-70.6%) for the detection of colorectal cancers. Furthermore, detection of NEUROG1 methylation was independent of age and gender.
Methylation of the NEUROG1 gene is frequently found in sera of patients with colorectal cancers independent of tumor stage. The quantitative detection of NEUROG1 DNA methylation in serum is a suitable approach for the non-invasive screening for asymptomatic colorectal cancer.
To investigate the role of DRO1 in obesity and adipogenesis in vivo, we generated a constitutive Dro1 knockout mouse model and analyzed the effect of DRO1 loss on body growth under standard and high ...fat diet feeding conditions. Loss of DRO1 resulted in a significant increase in body weight which was accompanied by a substantial expansion of white adipose tissue depots. The obese phenotype could be further enhanced by a high fat dietary challenge which also resulted in impaired glucose metabolism and the development of hepatosteatosis in Dro1 knockout mice. To study the role of DRO1 in adipocyte differentiation, primary stromal-vascular (SV) cells were isolated from inguinal white fat pads of knockout and control mice. In primary SV cells, depletion of DRO1 significantly promoted adipogenesis with upregulation of markers for adipogenesis (Cebpa, Pparg, Adipoq) and lipid metabolism (Dgat1, Dgat2). Our results demonstrate that DRO1 is a crucial regulator of energy homeostasis in vivo and functions as an inhibitor of adipogenesis in primary cells.
•DRO1 regulates body weight and body fat mass.•Inactivation of DRO1 results in obesity and increased lean mass.•Adiposity upon DRO1 loss can further be enhanced by high fat diet.•DRO1 is a potent inhibitor of adipogenesis.
Wnt/β‐catenin signaling plays a crucial role in the regulation of colon tissue regeneration and the development of colon tumors. Under physiological conditions, β‐catenin activity is tightly ...controlled. However, the majority of sporadic forms of colorectal cancer are characterized by inactivation of the tumor suppressor gene APC due to loss of heterozygosity (LOH), resulting in deregulation of the protein β‐catenin. Apart from known β‐catenin target genes like MYC, OPG, and DKK4, the gene TNFRSF19, a member of the TNF receptor superfamily, is regulated by β‐catenin in mesenchymal stem cells (hMSC). We found that TNFRSF19 is frequently overexpressed in colorectal cancer cell lines and primary colorectal carcinomas. Further characterization revealed that both isoforms of TNFRSF19, TNFRSF19.1 and TNFRSF19.2, are regulated in a β‐catenin dependent manner. The transcript TNFRSF19.2 encodes a 417 amino acid long protein containing a TRAF‐binding site that links the TNFRSF19.2 to NF‐κB signaling, whereas the isoform TNFRSF19.1 lacks this TRAF‐binding site. Nevertheless both isoform 1 and 2 induced the activity of an NF‐κB reporter gene. NF‐κB signaling is important for inflammatory processes and chronic inflammatory diseases like ulcerative colitis and Crohn's disease, which are associated with increased risk for developing colorectal cancer. The observation that TNFRSF19 is a β‐catenin target gene and TNFRSF19 receptor molecules activate NF‐κB signaling shows that β‐catenin regulates NF‐κB activity via TNFRSF19, suggesting that TNFRSF19 may contribute to the development of colorectal tumors with deregulated β‐catenin activity.
What's new?
Dozens of proteins work together to keep cell proliferation and other functions running smoothly. Altering one protein's expression impacts many other molecules, and discovering how they interact can suggest strategies for righting the disrupted cellular processes that cause cancer. Sporadic colorectal cancer frequently involves deactivation of the APC gene, which leads to loss of regulation of the protein beta‐catenin. In this study, the authors investigated a target of beta‐catenin called TNFRSF19, a member of the tumor necrosis factor receptor superfamily. They discovered that TNFRSF19 is overexpressed in colorectal cancers, and that it activates NF‐kB signaling. Identifying this link between β‐catenin and NF‐kB signaling implies a pathway by which loss of control over beta‐catenin could lead to cancer, as NF‐kB is well known for its regulatory role in cell proliferation.
Detection of methylated free‐circulating DNA (mfcDNA) for hyperplastic polyposis 1 (HPP1) in blood is correlated with a poor prognosis for patients with metastatic colorectal cancers (mCRC). Here, we ...analyzed the plasma levels of HPP1 mfcDNA in mCRC patients treated with a combination therapy containing a fluoropyrimidine, oxaliplatin and bevacizumab to test whether HPP1 mfcDNA is a suitable prognostic and response biomarker. From 467 patients of the prospective clinical study AIO‐KRK‐0207, mfcDNA was isolated from plasma samples at different time points and bisulfite‐treated mfcDNA was quantified using methylation specific PCR. About 337 of 467 patients had detectable levels for HPP1 mfcDNA before start of treatment. The detection was significantly correlated with poorer overall survival (OS) (HR = 1.86; 95%CI 1.37–2.53). About 2–3 weeks after the first administration of combination chemotherapy, HPP1 mfcDNA was reduced to non‐detectable levels in 167 of 337 patients. These patients showed a better OS compared with patients with continued detection of HPP1 mfcDNA (HR HPP1(sample 1: pos/ sample 2: neg) vs. HPP1(neg/neg) = 1.41; 95%CI 1.00–2.01, HPP1(neg,pos/pos) vs. HPP1(neg/neg) = 2.60; 95%CI 1.86–3.64). Receiver operating characteristic analysis demonstrated that HPP1 mfcDNA discriminates well between patients who do (not) respond to therapy according to the radiological staging after 12 or 24 weeks (AUC = 0.77 or 0.71, respectively). Detection of HPP1 mfcDNA can be used as a prognostic marker and an early marker for response (as early as 3–4 weeks after start of treatment compared with radiological staging after 12 or 24 weeks) to identify patients who will likely benefit from a combination chemotherapy with bevacizumab.
What's new?
Tumor cells of primary tumors and metastases are constantly turned over with their DNA being released into blood circulation. Here the authors quantified circulating DNA of the hyperplastic polyposis 1 (HPP1) gene, which is frequently methylated in colorectal tumors, in a prospective clinical study of combination chemotherapy in patients with metastatic colorectal cancer. They confirmed their previous finding that HPP1 methylated free‐circulating DNA (mfcDNA) is a prognostic marker for progression‐free and overall survival in these patients. In addition, HPP1 mfcDNA served as a marker differentiating between chemotherapy responders and non‐responders, underscoring the usefulness of DNA‐based biomarkers in cancer treatment.
This study demonstrates DRO1 to be a strong tumor suppressor in chemically induced colon carcinogenesis. Loss of DRO1 increases multiplicity of preneoplastic aberrant crypt foci and colonic tumors ...upon administration of AOM. Combined treatment with AOM and DSS leads to increased colonic tumor number and promotes formation of adenocarcinoma in the colon. Moreover, Dro1 inactivation aggravates clinical and histological signs of acute and chronic DSS-induced colitis, indicating a novel putative role for DRO1 in inflammatory bowel disease.
Abstract
Colorectal carcinogenesis is a progressive multistep process involving the sequential accumulation of genetic alterations in tumor suppressor genes and oncogenes. Downregulated by oncogenes 1 (Dro1/Ccdc80) has been shown to be a potent tumor suppressor of colorectal carcinogenesis in the genetic ApcMin/+ mouse model. In ApcMin/+ mice, loss of DRO1 strongly increases colonic tumor multiplicity and leads to the regular formation of adenocarcinoma in the colon. To investigate DRO1's role in chemically induced as well as inflammation-associated colorectal carcinogenesis, the effect of Dro1 inactivation was studied in mice subjected to the carcinogen azoxymethane (AOM) and upon combined treatment with AOM and the proinflammatory agent dextran sodium sulfate (DSS), respectively. Loss of DRO1 increases multiplicity of preneoplastic aberrant crypt foci and colonic tumors upon administration of AOM. Combined treatment with AOM and DSS leads to increased colonic tumor number and promotes formation of adenocarcinoma in the colon. Moreover, Dro1 inactivation aggravates histological signs of acute and chronic DSS-induced colitis, strongly enlarges the size of ulcerative lesions in the intestinal lining, and exacerbates clinical signs and morbidity by DSS. Our results demonstrate DRO1 to be a strong tumor suppressor in the chemically induced colon carcinogenic mouse model. Additionally, we demonstrate DRO1 to inhibit colitis-associated colon cancer formation and uncover a novel putative role for DRO1 in inflammatory bowel disease.
Fibroblast growth factor receptors are expressed in diverse cell types. They play a critical role in tumor development. Their activation promotes cell-cycle progression, angiogenesis, and cell ...survival by induction/suppression of the expression of proteins involved.
Non-small cell lung cancer (NSCLC) cells (line H1581) were treated with NVP-BGJ398 to evaluate effects on growth by western blot, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay and cell-cycle analysis.
NVP-BGJ398 induced cell death in H1581 cells by activating caspase-dependent mitochondrial and non-mitochondrial pathways. Caspase-independent apoptosis was also activated. Cells were found to be arrested in the G0/G1 phase. Furthermore, the expression of the tumor-suppressor gene programmed cell death 4 (PDCD4) was up-regulated with suppression of angiopoietin 2 (ANG2). This represents an additional mechanism by which NVP-BGJ389 inhibits tumor growth.
Various pathways induce apoptosis in NSCLC cells by employing NVP-BGJ398. These data reflect the potential of cancer treatment utilizing small FGFR inhibitors.
Purpose
γ-Catenin is a protein closely related to β-catenin. While the overexpression of β-catenin has been linked with impaired prognosis and survival in various malignancies, both oncogenic and ...tumor suppressor functions have been described for γ-catenin. Thus, its role in cancer remains controversial. In this study, we examined the impact of γ-catenin expression on the malignant potential of colorectal cancer cells.
Methods
γ-Catenin was knocked down by short interfering RNA in the γ-catenin-proficient DLD-1 cell line and stably overexpressed in the γ-catenin-deficient cell line RKO. The effects of these molecular manipulations on the malignant potential of the cell lines were tested in vitro and in vivo in a xenograft tumor model.
Results
γ-Catenin contributed to Wnt signaling independent of the cellular context. Unlike its sister molecule β-catenin, γ-catenin inhibited cellular invasion and anoikis in cells endogenously expressing γ-catenin. In line with this tumor suppressor function, its de novo expression in RKO cells inhibited proliferation via cell cycle arrest. In a xenograft tumor model, overexpression of γ-catenin starkly reduced tumor growth in vivo.
Conclusions
This is the first report demonstrating a tumor-suppressive effect of γ-catenin in colorectal cancer both in vitro and in vivo. Detailed in vitro analysis revealed that effects of γ-catenin differ in γ-catenin proficient and deficient cells, indicating that its function in colorectal cancer is dependent on the cellular context. This finding adds to our understanding of γ-catenin and may have implications for future studies of catenin/Wnt targeted cancer therapies.
Tumors are composed of the tumor cells and the surrounding microenvironment. Both are closely interwoven and interact by a complex and multifaceted cross-talk which plays an integral part in tumor ...initiation, growth, and progression.
has been shown to be a potent suppressor of colorectal cancer and ubiquitous inactivation of
strongly promoted colorectal carcinogenesis in
mice and in a chemically-induced colorectal cancer model. The aim of the present study was to investigate whether
's tumor suppressive function is tumor-cell-autonomous. Expression of
in cancer cells had no effect on both colon tumor development in
mice and formation of xenograft tumors. In contrast, DRO1/CCDC80 loss in the microenvironment strongly increased tumor growth in xenograft models, inhibited cancer cell apoptosis, and promoted intestinal epithelial cell migration. Moreover, stromal
inactivation facilitated formation of intestinal epithelial organoids. Expression analyses showed
to be significantly down-regulated in murine gastric cancer associated fibroblasts, in
colon tumor primary stromal cells and in microdissected stroma from human colorectal cancer compared to normal, non-tumor stroma. Our results demonstrate epithelial derived DRO1/CCDC80 to be dispensable for intestinal tissue homeostasis and identify Dro1/Ccdc80 as tumor suppressor in the tumor microenvironment.
Purpose gamma-Catenin is a protein closely related to beta-catenin. While the overexpression of beta-catenin has been linked with impaired prognosis and survival in various malignancies, both ...oncogenic and tumor suppressor functions have been described for gamma-catenin. Thus, its role in cancer remains controversial. In this study, we examined the impact of gamma-catenin expression on the malignant potential of colorectal cancer cells. Methods gamma-Catenin was knocked down by short interfering RNA in the gamma-catenin-proficient DLD-1 cell line and stably overexpressed in the gamma-catenin-deficient cell line RKO. The effects of these molecular manipulations on the malignant potential of the cell lines were tested in vitro and in vivo in a xenograft tumor model. Results gamma-Catenin contributed to Wnt signaling independent of the cellular context. Unlike its sister molecule beta-catenin, gamma-catenin inhibited cellular invasion and anoikis in cells endogenously expressing gamma-catenin. In line with this tumor suppressor function, its de novo expression in RKO cells inhibited proliferation via cell cycle arrest. In a xenograft tumor model, overexpression of gamma-catenin starkly reduced tumor growth in vivo. Conclusions This is the first report demonstrating a tumor-suppressive effect of gamma-catenin in colorectal cancer both in vitro and in vivo. Detailed in vitro analysis revealed that effects of gamma-catenin differ in gamma-catenin proficient and deficient cells, indicating that its function in colorectal cancer is dependent on the cellular context. This finding adds to our understanding of gamma-catenin and may have implications for future studies of catenin/Wnt targeted cancer therapies.
Carcinoembryonic antigen (CEA) is the only established serum biomarker for colorectal cancer (CRC). To facilitate therapy decisions and improve the overall survival of CRC patients, prognostic ...biomarkers are required.
We studied the prognostic value of five different cell free circulating DNA (fcDNA) fragments. The potential markers were ALU115, ALU247, LINE1-79, LINE1-300 and ND1-mt.
The copy numbers of the DNA fragments were measured in the peripheral blood serum of 268 CRC patients using qPCR, the results were compared to common and previously described markers.
We found that ALU115 and ALU247 fcDNA levels correlate significantly with several clinicopathological parameters. An increased amount of ALU115 and ALU247 fcDNA fragments coincides with methylation of HPP1 (P< 0.001; P< 0.01), which proved to be a prognostic marker itself in former studies and also with increased CEA level (both P< 0.001). ALU115 and ALU247 can define patients with poor survival in UICC stage IV (ALU115: HR = 2.9; 95% Cl 1.8-4.8, P< 0.001; ALU247: HR = 2.2; 95% Cl 1.3-3.6; P= 0.001). Combining ALU115 and HPP1, the prognostic value in UICC stage IV is highly significant (P< 0.001).
This study shows that an increased level of ALU fcDNA is an independent prognostic biomarker for advanced colorectal cancer disease.
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