Polyamines (spermine and spermidine) play many important roles in cellular function and are supplied from the intestinal lumen. We have shown that continuous high polyamine intake inhibits age-associated pathologies in mice. The mechanism by which polyamines elicit these effects was examined. Twenty-four week old Jc1:ICR male mice were fed one of three experimental chows containing different polyamine concentrations. Lifetime intake of high polyamine chow, which had a polyamine content approximately three times higher than regular chow, elevated polyamine concentrations in whole blood, suppressed age-associated increases in pro-inflammatory status, decreased age-associated pathological changes, inhibited age-associated global alteration in DNA methylation status and reduced the mortality in aged mice. Exogenous spermine augmented DNA methyltransferase activity in Jurkat and HT-29 cells and inhibited polyamine deficiency-induced global alteration in DNA methylation status in vitro. In addition, increased polyamine intake was associated with a decreased incidence of colon tumors in BALB/c mice after 1,2-demethylhydrazine administration; 12 mice (60%) in the low polyamine group developed tumors, compared with only 5 mice (25%) in the high polyamine group (Fisher's exact probability = 0.027, p = 0.025). However, increased polyamine intake accelerated the growth of established tumors; maximal tumor diameter in the Low and High groups was 3.85±0.90 mm and 5.50±1.93 mm, respectively (Mann-Whitney test, p = 0.039). Spermine seems to play important roles in inhibiting age-associated and polyamine-deficient induced abnormal gene methylation as well as pathological changes including tumorigenesis.
Some colon cancer (CC) patients present synchronous cancers at diagnosis and others develop metachronous neoplasms, but the risk factors are unclear for non-hereditary CC. We showed previously that global DNA demethylation increased with aging and correlated with genomic damage in CC, and we show now that preferentially associates to CCs with wild-type p53. This study aimed to elucidate the extent of DNA hypomethylation in patients with single and multiple CC, its relationship with aging, and its potential as predictive tool. We compared by real-time methylation-specific PCR the relative demethylation level (RDL) of long interspersed nucleotide element-1 (LINE-1) sequences in matched cancer tissues and non-cancerous colonic mucosa (NCM) from patients with single and multiple right-sided CCs. Although no RDL difference was found in NCM from single CC patients and healthy volunteers (P =0.5), there was more demethylation (higher RDL) in NCM from synchronous cancer patients (P =1.1 × 10−5) multiple CCs also were more demethylated than single CCs (P =0.0014). High NCM demethylation was predictive for metachronous neoplasms (P =0.003). In multivariate logistic regression analyses RDL was the only independent predictor for metachronous (P =0.02) and multiple (P =4.9 × 10−5) tumors. The higher LINE-1 demethylation in NCM from patients with multiple (synchronous and metachronous) tumors (P =9.6 × 10−7) was also very significant in patients with tumors without (P =3.8 × 10−6), but not with (P =0.16) microsatellite instability. NCM demethylation increased with aging in patients with single tumors, but decreased in those with multiple tumors. Moreover, the demethylation difference between patients with single vs multiple tumors appeared higher in younger (P =3.6 × 10−4) than in older (P =0.0016) patients. These results predict that LINE-1 hypomethylation in NCM can be used as an epigenetic predictive biomarker for multiple CC risk. The stronger association of demethylation in NCM with multiple CC risk from younger patients also suggests an inherited predisposition for the apparent field cancerization effect of somatic demethylation.
BackgroundRecent work led to recognize sessile serrated adenomas (SSA) as precursor to many of the sporadic colorectal cancers with microsatellite instability (MSI). However, comprehensive analyses of DNA methylation in SSA and MSI cancer have not been conducted.MethodsWith an array-based methylation sensitive amplified fragment length polymorphism (MS-AFLP) method we analyzed 8 tubular (TA) and 19 serrated (SSA) adenomas, and 14 carcinomas with (MSI) and 12 without (MSS) microsatellite instability. MS-AFLP array can survey relative differences in methylation between normal and tumor tissues of 9,654 DNA fragments containing all NotI sequences in the human genome.ResultsUnsupervised clustering analysis of the genome-wide hypermethylation alterations revealed no major differences between or within these groups of benign and malignant tumors regardless of their location in intergenic, intragenic, promoter, or 3′ end regions. Hypomethylation was less frequent in SSAs compared with MSI or MSS carcinomas. Analysis of variance of DNA methylation between these four subgroups identified 56 probes differentially altered. The hierarchical tree of this subset of probes revealed two distinct clusters: Group 1, mostly composed by TAs and MSS cancers with KRAS mutations; and Group 2 with BRAF mutations, which consisted of cancers with MSI and MLH1 methylation (Group 2A), and SSAs without MLH1 methylation (Group 2B). AXIN2, which cooperates with APC and β-catenin in Wnt signaling, had more methylation alterations in Group 2, and its expression levels negatively correlated with methylation determined by bisulfite sequencing. Within group 2B, low and high AXIN2 expression levels correlated significantly with differences in size (P = 0.01) location (P = 0.05) and crypt architecture (P = 0.01).ConclusionsSomatic methylation alterations of AXIN2, associated with changes in its expression, stratify SSAs according to some clinico-pathological differences. We conclude that hypermethylation of MLH1, when occurs in an adenoma cell with BRAF oncogenic mutational activation, drives the pathway for MSI cancer by providing the cells with a mutator phenotype. AXIN2 inactivation may contribute to this tumorigenic pathway either by mutator phenotype driven frameshift mutations or by epigenetic deregulation contemporary with the unfolding of the mutator phenotype.
INTRODUCTIONFew reports detail adequate surgical management of giant pelvic tumors that traverse the sciatic foramen.PRESENTATION OF CASEWe present a case of a giant retroperitoneal pelvic lipoma that presented with a dumbbell shape on imaging, occupying the entire lesser pelvis and protruding to the gluteus through the sciatic foramen. Surgery was performed for en bloc resection of the tumor.DISCUSSIONA parasacral approach with the patient in the prone position was necessary to dissect the tumor in the buttock, manipulate around the sciatic foramen and preserve collateral blood flow for the gluteal muscle. An abdominal approach was also essential to ligate the internal iliac vessels involved in the tumor. Accordingly changings the position of the patient during the operation were required. Division of the sacrotuberous and sacrospinous ligaments and packing of the soft tumor into a plastic bag were useful to pass the buttock portion through the foramen without the tumor breaking off.CONCLUSIONThe asynchronous abdomino-parasacral approach with several turnings of the patient's body and plastic bag packing of the tumor were advantageous to manage en bloc resection of the giant pelvic lipoma presented in this case study.
Wandering spleen is a rare clinical entity, and its chronic torsion of the vascular pedicle result in splenic vein occlusion leading to gastric varices. Here, we present a case of wandering spleen complicating gastric varices in a 40-year-old female. Three-dimensional CT (3D-CT) clearly showed the disruption of the splenic vein at the origin of the vascular pedicle and collateral development of the gastric varices. The patient was electively treated with laparoscopic splenectomy. Difficulty of prediction of the splenic vein recanalization to improve the varices was the reason for the use of splenectomy versus splenopexy. The varices were successfully diminished 3 months after the surgery. After review of cases of complicating gastric varices in the literatures, splenectomy is still a secure way to treat an adult patient with wandering spleen with complicating gastric varices.
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