Promoter hypomethylation and reactivation of MAGE-A1 and MAGE-A3 genes in colorectal cancer cell lines and cancer tissues

AIM: To verify the expression and methylation status o the MAGE-A1 and MAGE-A3 genes in colorectal cance tissues and cancer cell lines. METHODS: We evaluated promoter demethylation status of the MAGE-A1 and MAGE-A3 genes by RT-PCR analysis and methylation-specific PCR (MS-PCR), as we as sequencing analysis, after sodium bisulfite modifica tion in 32 colorectal cancer cell lines and 87 cancer tis sues. RESULTS: Of the 32 cell lines, MAGE-A1 and MAGE-A3 expressions were observed in 59% and 66%, respective ly. Subsequent to sodium bisulfite modification and MS PCR analysis, the promoter hypomethylation of MAGE-A1 and MAGE-A3 was confirmed in both at 81% each Promoter hypomethylation of MAGE-A1 and MAGE-A3 in colorectal cancer tissues was observed in 43% and 77% respectively. Hypomethylation of MAGE-A1 and MAGE-A3 genes in corresponding normal tissues were observed in 2% and 6%, respectively. CONCLUSION: The promoter hypomethylation of MAGE genes up-regulates its expression in colorectal carcino mas as well as in gastric cancers and might play a signif icant role in the development and progression of human colorectal carcinomas.

Promoter hypermethylation and loss of CD133 gene expression in colorectal cancers

AIM: To understand CD133 promoter hypermethyl-ation and expression in 32 colorectal cancer cell lines. METHODS: Nucleic acid was isolated from 32 colorectal cancer cell lines and CD133 expression levels were measured by reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR. Promoter methylation status of the CD133 gene was analyzed with a methylation-specific PCR after sodium-bisulfi te modification and by clonal sequencing analysis. The correlation between expression and promoter methylation of CD133 gene was confirmed with treatment of 5-aza-2’-deoxycytidine. RESULTS: We measured CD133 expression levels in 32 colorectal cancer cell lines. RT-PCR analysis showed undetectable or low levels of CD133 expression in 34.4%of cell lines. To verify the relation between CD133 expression and methylation status of the CD133 gene promoter in colorectal carcinogenesis, CD133 gene promoter hypermethylation was analyzed in 32 cancer cell lines. Promoter hypermethylation was detected in 13 (40.6%) of the cell lines using methylation specificPCR and confirmed by bisulfite sequencing analysis. Treatment of 11 of the cell lines with the demethylation agent 5-aza-2’-deoxycytidine recovered CD133 expression in most of them. CONCLUSION: Transcriptional repression of CD133 is caused by promoter hypermethylation of the CD133 CpG islands in some of colorectal cancer cell lines. The study may contribute to the understanding of the role of CD133 inactivation in the progression of colorectal cancers.

An optimized procedure for plant recovery from somatic embryos significantly facilitates the genetic improvement of Vitis

Plant regeneration from grapevine(Vitis spp.)via somatic embryogenesis typically is poor.Recovery of plants from Vitis rotundifolia Michx.(muscadine grape)is particularly problematic due to extremely low efficiency,including extended culture durations required for embryo–plant conversion.Poor plant recovery is an obstacle to the selection of improved genetically modified lines.Somatic embryos(SEs)of V.rotundifolia cultivar Delicious(Del-HS)and Vitis vinifera L cultivar Thompson Seedless(TS)were used to identify culture media and conditions that promoted embryo differentiation and plant conversion;this resulted in a two-step culture system.In comparative culture experiments,C2D medium containing 6%sucrose was the most effective,among four distinct formulae tested,for inducing precocious SE germination and cell differentiation.This medium,further supplemented with 4 mM 6-benzylaminopurine(C2D4B),was subsequently determined to enhance post-germinative growth of SE.MS medium supplemented with 0.5 mM 1-naphthaleneacetic acid(MSN)was then utilized to stimulate root and shoot growth of germinated SE.An average of 35%and 80%‘Del-HS’and‘TS’SE,respectively,developed into plants.All plants developed robust root and shoot systems and exhibited excellent survival following transfer to soil.Over 150 plants of‘Del-HS’were regenerated and established within 2.5 months,which is a dramatic reduction from the 6-to 12-month time period previously required.Similarly,88‘TS’plant lines were obtained within the same time period.Subsequently,seven out of eight Vitis cultivars exhibited significantly increased plant conversion percentages,demonstrating broad application of the two-step culture system to produce the large numbers of independent plant lines needed for selection of desired traits.

Sarcomatoid carcinoma of the pancreas—multimodality imaging findings with serial imaging follow-up:A case report and review of literature

BACKGROUND Sarcomatoid carcinoma of the pancreas is extremely rare and has an extremely poor prognosis.Although a few cases of sarcomatoid carcinoma of pancreas have been reported,most are focused on a histopathological review.To the best of our knowledge,there are no reports documenting multimodality imaging characteristics and chronological changes with emphasis on radiologic features.CASE SUMMARY A 64-year-old woman was admitted to Chungnam National University Hospital with acute appendicitis.Contrast-enhanced computed tomography of the abdomen revealed a 2.6 cm×2.8 cm multilobular cystic mass in the pancreatic tail.The pancreatic lesion showed suspected mural nodules and thin septa.Hence,mucinous cystic neoplasm of pancreas was considered.After 7 mo,the patient was readmitted for repeated epigastric abdominal pain and nausea.Follow-up contrast-enhanced computed tomography of the abdomen and magnetic resonance imaging revealed a marked enlargement(5.4 cm×4 cm),with a predominant internal solid component.The mass showed low signal intensity on a T1-weighted image and heterogeneously intermediate high signal intensity on a T2-weighted image. It showed diffusion restriction and peripheral rimenhancement on an arterial phase image, and progressive enhancement on portalvenous and delayed phase images. Distal pancreatectomy was performed. Basedon the morphology and immunohistochemical staining of the specimen,pancreatic sarcomatoid carcinoma was diagnosed.CONCLUSIONWe present the computed tomography, magnetic resonance imaging, and positronemission tomography computed tomography findings, pathologic features, andchronological changes for preoperative diagnosis.