APC mutations are common in adenomas but infrequent in adenocarcinomas of the non-ampullary duodenum.

BACKGROUND: Recent studies highlighted the clinicopathological heterogeneity of non-ampullary duodenal adenomas and adenocarcinomas, but the detailed process of the malignant transformation remains unclear. METHODS: We analyzed 144 adenomas and 54 adenocarcinomas of the non-ampullary duodenum for immunohistochemical phenotypes, genetic alterations, and mismatch repair (MMR) status to probe their histogenetic relationship. RESULTS: The median ages of patients with adenoma and adenocarcinoma were the same (66 years). Adenomas were histologically classified as intestinal-type adenoma (n = 124), pyloric gland adenoma (PGA, n = 10), gastric-type adenoma, not otherwise specified (n = 9), and foveolar-type adenoma (n = 1). Protein-truncating APC mutations were highly frequent in adenomas (85%), with the highest prevalence in intestinal-type adenomas (89%), but rare in adenocarcinomas (9%; P = 2.1 × 10-23). Close associations between phenotypic marker expression and genetic alterations were observed in adenomas, but not in adenocarcinomas, excluding the common association between GNAS mutations and MUC5AC expression. MMR deficiency was more frequent in adenocarcinomas (20%) than in adenomas (1%; P = 2.6 × 10-6). One MMR-deficient adenoma and three MMR-deficient adenocarcinomas occurred in patients with Lynch syndrome. Additionally, three other patients with an MMR-deficient adenocarcinoma fulfilled the revised Bethesda criteria. CONCLUSION: The discrepant APC mutation frequency between adenomas and adenocarcinomas suggests that APC-mutated adenomas, which constitute the large majority of non-ampullary duodenal adenomas, are less prone to malignant transformation. Non-ampullary duodenal adenocarcinomas frequently exhibit MMR deficiency and should be subject to MMR testing to determine appropriate clinical management, including the identification of patients with Lynch syndrome.

Acarbose improved survival for Apc+/Min mice.

Acarbose blocks the digestion of complex carbohydrates, and the NIA Intervention Testing Program (ITP) found that it improved survival when fed to mice. Yet, we do not know if lifespan extension was caused by its effect on metabolism with regard to the soma or cancer suppression. Cancer caused death for ~80% of ITP mice. The ITP found rapamycin, an inhibitor to the pro-growth mTORC1 (mechanistic target of rapamycin complex 1) pathway, improved survival and it suppressed tumors in Apc+/Min mice providing a plausible rationale to ask if acarbose had a similar effect. Apc+/Min is a mouse model prone to intestinal polyposis and a mimic of familial adenomatous polyposis in people. Polyp-associated anemia contributed to their death. To address this knowledge gap, we fed two doses of acarbose to Apc+/Min mice. Acarbose improved median survival at both doses. A cross-sectional analysis was performed next. At both doses, ACA fed mice exhibited reduced intestinal crypt depth, weight loss despite increased food consumption and reduced postprandial blood glucose and plasma insulin, indicative of improved insulin sensitivity. Dose-independent and dose-dependent compensatory liver responses were observed for AMPK and mTORC1 activities, respectively. Only mice fed the high dose diet exhibited reductions in tumor number with higher hematocrits. Because low-dose acarbose improved lifespan but failed to reduced tumors, its effects seem to be independent of cancer. These data implicate the importance of improved carbohydrate metabolism on survival.

Rapid response of stage IV colorectal cancer with APC/TP53/KRAS mutations to FOLFIRI and Bevacizumab combination chemotherapy: a case report of use of liquid biopsy.

BACKGROUND: Liquid biopsies of blood plasma cell free DNA can be used to monitor treatment response and potentially detect mutations that are present in resistant clones in metastatic cancer patients. CASE PRESENTATION: In our non-interventional liquid biopsy study, a male patient in his fifties diagnosed with stage IV colorectal cancer and polytope liver metastases rapidly progressed after completing chemotherapy and deceased 8 months after diagnosis. Retrospective cell free DNA testing showed that the APC/TP53/KRAS major clone responded quickly after 3 cycles of FOLFIRI + Bevacizumab. Retrospective exome sequencing of pre-chemotherapy and post-chemotherapy tissue samples including metastases confirmed that the APC/TP53/KRAS and other major clonal mutations (GPR50, SLC5A, ZIC3, SF3A1 and others) were present in all samples. After the last chemotherapy cycle, CT imaging, CEA and CA19-9 markers validated the cfDNA findings of treatment response. However, 5 weeks later, the tumour had rapidly progressed. CONCLUSION: As FOLFIRI+Bevacizumab has recently also been associated with sustained complete remission in a APC/TP53/KRAS triple-mutated patient, these driver genes should be tested and monitored in a more in-depth manner in future patients. Patients with metastatic disease should be monitored more closely during and after chemotherapy, ideally using cfDNA.

A sensitive fluorometric DNA nanobiosensor based on a new fluorophore for tumor suppressor gene detection.

In this study, a sensitive fluorescent DNA nanobiosensor has been developed to determine DNA sequence of a well-known tumor suppressor gene, Adenomatous Polyposis Coli (APC). The design of the nanobiosensor was carried out using a synthetic organic ligand as a new fluorophore. The response mechanism of the nanobiosensor was based on DNA hybridization. The new fluorophore was assembled on gold nanoparticles (Au NPs) to enhance the sensitivity of the nanobiosensor response. The fabricated DNA nanobiosensor showed a fluorescence emission at 477 nm by exciting wavelength of 360 nm. By addition of the ssDNA target, the fluorescent emission of the nanobiosensor enhanced linearly in the range from 3.3 × 10-10 to 1.1 × 10-9 mol L-1 with detection limit of 1.3 × 10-11 mol L-1. The proposed DNA nanobiosensor responded selectively to its complementary strand in comparison with non-complementary and three mismatched bases. The nanobiosensor had also a fast response time with acceptable repeatability. Finally, the performance of the DNA nanobiosensor in biological fluid, serum plasma, was investigated and a satisfactory results were obtained.

APC gene promoter aberrant methylation in serum as a biomarker for breast cancer diagnosis: A meta-analysis.

BACKGROUND: The aim of this study was to evaluate the clinical efficacy of APC gene promoter methylation in serum as a biomarker for breast cancer (BC) diagnosis. METHODS: Two reviewers systematically searched online resources to identify the publications relevant to APC gene promoter methylation and BC. The data of true positive, false positive, false negative, and true negative were extracted from each included study and pooled for diagnostic sensitivity, specificity, and summary receiver operating characteristic curve. RESULTS: Twelve studies finally fulfilled the inclusion criteria and were included in this meta-analysis. The diagnostic sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio, and area under the receiver operating characteristic curve were 0.20 (95% confidence interval [CI] 0.17-0.23), 0.96 (95% CI 0.93-0.97), 3.69 (95% CI 1.60-8.50), 0.83 (95% CI 0.75-0.92), 4.58 (95% CI 1.85-11.37) and 0.80, respectively. A Deeks' funnel plot and Egger's line regression test (t = 1.43, P = 0.18) indicated no publication bias was present. CONCLUSION: Because of low sensitivity, APC gene promoter methylation in serum was not suitable for BC screening. However, as specificity was very high, detection of serum APC gene promoter methylation could be used as tool to confirm BC.

Palmatine from Mahonia bealei attenuates gut tumorigenesis in ApcMin/+ mice via inhibition of inflammatory cytokines.

Mahonia bealei is a Chinese folk medicine used to treat various ailments, in particular gastrointestinal inflammation­related illnesses, and palmatine is one of its active constituents. In this study, ApcMin/+ mice, a genetically engineered model, were used to investigate the effects of palmatine on the initiation and progression of gut inflammation and tumorigenesis enhanced by a high­fat diet. The in vitro antiproliferation and anti­inflammation effects of palmatine were evaluated on HT­29 and SW­480 human colorectal cancer cell lines. The concentration­related antiproliferative effects of palmatine on both cell lines (P<0.01) were observed. Palmatine significantly inhibited lipopolysaccharide­induced increase in cytokine interleukin (IL)­8 levels in the HT­29 cells (P<0.01). In the in vivo studies with ApcMin/+ mice, after 10 or 20 mg/kg/day oral palmatine treatment, tumor numbers were significantly reduced in the small intestine and colon in a dose­dependent manner (P<0.01 compared with the model group). The results were supported by tumor distribution data, body weight changes and organ index. The effect on survival was also dose­dependent. Both the low­ and high­dose palmatine treatments significantly increased the life span of the mice (P<0.01). The gut histology from the model group showed a prominent adenomatous change along with inflammatory lesions. With palmatine treatment, however, the dysplastic changes were greatly reduced in the small intestine and colon tissue. Reverse transcription­quantitative polymerase chain reaction analysis of interleukin (IL)­1α, IL1­ß, IL­8, granulocyte­colony stimulating factor and granulocyte macrophage colony­stimulating factor in the gut tissue showed that these inflammatory cytokines were reduced significantly following treatment (all P<0.01); serum cytokine levels were also decreased. Data suggests that palmatine has a clinical value in colorectal cancer therapeutics, and this action is likely linked to the inhibition of inflammatory cytokines.

Aberrant methylation of APC and RARß2 genes in breast cancer patients.

Changes in the status of DNA methylation are one of the most common molecular alterations in human neoplasia. We aimed to identify epigenetic molecular markers in serum for early detection of breast cancer. Authors analyzed retrospectively the methylation status of RARß2 and APC genes in serum samples from 121 breast cancer patients, 79 patients with benign breast diseases, and 66 healthy volunteers using methylation-specific PCR. The methylated APC and RARß2 were significantly higher in breast cancer patients (93.4%, 95.6%) than benign (7.8%, 14.5%) but not detected in healthy volunteers (0%) at (P < 0.0001). Both methylated genes showed no significant difference among clinicopathological factors apart from triple negative breast cancer patients as all of them (χ(2) = 7.4, P = 0.007) reported to be methylated RARß2 genes. Both methylated genes were detected in all grades and stages. Both sensitivities and specificities of the methylated genes for breast cancer detection were superior to traditional tumor markers in detection of breast cancer, early stage, low grade tumors, and triple negative breast cancer patients. Thus methylated APC and RARß2 genes might be valuable serum-based molecular markers for early detection of breast cancer.

[Methylation quantification of adenomatous polyposis coli (APC) gene promoter in plasma of lung cancer patients].

BACKGROUND AND OBJECTIVE: The protein encoded by adenomatous polyposis coli (APC) gene participates in the signaling transduction pathway. Substantial studies have revealed that hypermethylation of APC gene promoter is closely related to the pathogenesis and development of cancer. This study was to develop a real-time quantitative methylation specific PCR (real-time QMSP) method, and detect the methylation of APC gene promoter in plasma of lung cancer patients. METHODS: Genomic DNA with methylated APC gene promoter was extracted from the lung cancer cell line NCI-H460 using phenol-chloroform and quantified by spectrophotometric measurements. DNA was added into 200 microL plasma samples of healthy volunteers to make 10-fold serial dilutions. Circulating DNA from simulated plasma samples, 78 lung cancer patients, 31 patients with benign lung diseases and 23 health controls was extracted using magnetic beads and modified by bisulfite. The concentration of cell-free methylated APC gene promoter in the plasma samples was quantified by the external reference method with the standard curve constructed using simulated plasma. RESULTS: The linear range of the real-time QMSP assay was 1.5x10(2)-1.5x10(5) copies/ mL and its lowest detectability was 1.5x10(2) copies per milliliter plasma. Of 78 lung cancer patients, positive methylation of the APC gene promoter was detected in tumor tissues of 40 cases. Among the 40 lung cancer patients, positive methylation of the APC gene promoter was found in the plasma of 19 patients (47.5%). The concentrations of methylated APC promoter in the 19 lung cancer patients ranged from 1.67x10(2) to 6.78x10(3) copies/mL, with a median concentration of 1.67x10(3) copies/mL. No positive methylation of the APC gene promoter was detected in the plasma of 38 lung cancer patients without APC gene methylation in tissues, 31 benign lung diseases and 23 healthy controls. CONCLUSIONS: The newly developed real-time QMSP method allows the quantitative measurement of APC gene promoter methylation in plasma. Hypermethylation of the APC gene promoter in plasma is a potential diagnostic marker for lung cancer diagnosis.

New molecular concepts of Barrett's esophagus: clinical implications and biomarkers.

Barrett's esophagus (BE) represents the most serious histological consequence of gastroesophageal reflux disease (GERD) that develops in 5-10% of patients with GERD. Given that BE is the only known precursor to esophageal adenocarcinoma (EA), a systematic endoscopic biopsy protocol can detect EAs at an early stage. However, endoscopic and histopathological evaluation of BE are not adequate for effective screening of high risk patients. Therefore, molecular abnormalities associated with BE have been considered as surrogate markers and their use as such is proposed. Flow cytometry is the most useful adjunct to histology, and ploidy status of BE is an independent risk factor. Cyclin D1 overexpression is inversely correlated with survival in EA. C-erbB2 (+) patients have poorer prognosis. High plasma adenomatous polyposis coli levels correlate with reduced patient survival. p53 expression allows patient risk for EA stratification. Nuclear factor-kappaB overexpression inversely correlates with good response to adjuvant chemotherapy and radiotherapy in EA. Patients with cyclooxygenase-2 overexpression have reduced survival rates. Increased E-cadherin staining is associated with shorter survival in EA patients who received chemoradiotherapy. Finally, existing data cannot rule out a correlation between EA and colorectal tumors. Seventeen BE molecular alterations yielded noteworthy clinical implications. Apart from endoscopy and histology, these data allow for better risk stratification for patients with BE and for more efficient and timely therapeutic approaches.