72 research outputs found
Achalasia Combined with Esophageal Cancer Treated by Concurrent Chemoradiation Therapy
Achalasia is a rare neurological deficit of the esophagus that produces an impaired relaxation of the lower esophageal sphincter and decreased motility of the esophageal body. Achalasia is generally accepted to be a pre-malignant disorder, since, particularly in the mega-esophagus, chronic irritation by foods and bacterial overgrowth may contribute to the development of dysplasia and carcinoma. We present a case of a 51-year-old man with achalasia combined with esophageal cancer who has had dysphagia symptoms for more than 20 years. Since there was a clinically high possibility of supraclavicular lymph node metastasis, concurrent chemoradiation therapy was scheduled. After the third cycle of chemoradiation therapy, transthoracic esophageolymphadenectomy was performed. Histopathological examination of the main esophagus specimen revealed no residual carcinoma. And the entire regional lymph node areas were free of carcinoma except for one azygos metastatic lymph node. In summary, achalasia is a predisposing factor for esophageal squamous cell carcinoma. Although surveillance endoscopy in achalasia patients is still controversial, periodic screening for cancer development in long-standing achalasia patients might be advisable
Expression of Epstein-Barr Virus Gene and Clonality of Infiltrated T Lymphocytes in Epstein-Barr Virus-associated Gastric Carcinoma
BACKGROUND: Epstein-Barr virus associated gastric lymphoepithelioma-like carcinoma (LELC) is characterized by the intensive infiltration of lymphoid cells, the presence of EBV, and the better prognosis over typical adenocarcinoma. Thus, it was assumable that viral latent proteins may be responsible for the recruitment of a certain T cell repertoire to EBV-associated gastric carcinoma.
METHODS: To examine above possibility, EBV gene expression in gastric carcinoma tissues and usage of TCR among the tumor infiltrating lymphocytes were analyzed.
RESULTS: EBV specific DNA and EBERs RNA were detected in 4 out of 30 patients. RT-PCR analysis revealed that all 4 of EBV-positive tumor tissues expressed EBNA1 mRNA and BARTs and LMP2a was detected only one sample out of 4. However, the EBNA2 and LMP-1 transcripts were not detected in these tissues. CD8(+) T cells were the predominant population of infiltrating lymphocytes in the EBV-positive gastric carcinoma. According to spectra type analysis of infiltrating T cells, 10 predominant bands were detected by TCR Vβ CDR3 specific RT-PCR from 4 EBV-positive tumor tissues. Sequence analysis of these bands revealed oligoclonal expansion of T cells.
CONCLUSION: These findings suggest that clonally expanded T cells in vivo might be a population of cytotoxic T cells reactive to EBV-associated gastric carcinoma.ope
Depressed-Type of Early Colon Cancer with Extensive Lymph Node Metastasis
Early colorectal cancer (ECC) is defined as invasive tumor limited to the colonic and rectal mucosa or submucosa, regardless of the presence or absence of lymph node metastasis. The incidence of lymph node metastasis in ECC ranges from 0 to 15.4%, and risk factors include depth of submucosal invasion, growth patterns (polypoid or non-polypoid), histologic subclassification, and lymphatic invasion. Of non-polypoid growth patterns, the depressed types of colorectal cancer have higher malignant potential than polypoid types, even for small sizes. Unfortunately, this type is also difficult to detect on colonoscopic examination. In this report, we describe a case of depressed type ECC with extensive lymph node metastasis without regional lymph node involvement
Needle Knife-assisted Endoscopic Polypectomy for a Large Inflammatory Fibroid Colon Polyp by Making Its Stalk into an Omega Shape Using an Endoloop
Colonic inflammatory fibroid polyp (IFP) is an uncommon benign polypoid lesion, which is composed of fibroblasts, numerous small vessels and edematous connective tissue with marked eosinophilic inflammatory cell infiltration. This condition is frequently detected in the stomach and small intestine, but uncommon in the colon. Although IFP is a benign lesion, surgical resections are performed in most colonic cases because the polyps are usually too large to resect endoscopically. Only three patients underwent endoscopic polypectomy in our literature reviews. Here, we present a case of IFP in the descending colon successful endoscopically resected using a novel technique of trapping its stalk with an endoloop, forming the stalk into an omega shape, and then dissecting the stalk with a needle knife
Selective Translational Repression of Truncated Proteins from Frameshift Mutation-Derived mRNAs in Tumors
Frameshift and nonsense mutations are common in tumors with microsatellite instability, and mRNAs from these mutated genes have premature termination codons (PTCs). Abnormal mRNAs containing PTCs are normally degraded by the nonsense-mediated mRNA decay (NMD) system. However, PTCs located within 50–55 nucleotides of the last exon–exon junction are not recognized by NMD (NMD-irrelevant), and some PTC-containing mRNAs can escape from the NMD system (NMD-escape). We investigated protein expression from NMD-irrelevant and NMD-escape PTC-containing mRNAs by Western blotting and transfection assays. We demonstrated that transfection of NMD-irrelevant PTC-containing genomic DNA of MARCKS generates truncated protein. In contrast, NMD-escape PTC-containing versions of hMSH3 and TGFBR2 generate normal levels of mRNA, but do not generate detectable levels of protein. Transfection of NMD-escape mutant TGFBR2 genomic DNA failed to generate expression of truncated proteins, whereas transfection of wild-type TGFBR2 genomic DNA or mutant PTC-containing TGFBR2 cDNA generated expression of wild-type protein and truncated protein, respectively. Our findings suggest a novel mechanism of gene expression regulation for PTC-containing mRNAs in which the deleterious transcripts are regulated either by NMD or translational repression
Protein Kinase C-delta-Mediated Recycling of Active KIT in Colon Cancer
Purpose: Abnormal signaling through receptor tyrosine kinase (RTK) moieties is important in tumorigenesis and drug targeting of colorectal cancers. Wild-type KIT (WT-KIT), a RTK that is activated upon binding with stem cell factor (SCF), is highly expressed in some colon cancers; however, little is known about the functional role of SCF-dependent KIT activation in colon cancer pathogenesis. We aimed to elucidate the conditions and roles of WT-KIT activation in colon cancer tumorigenesis.Experimental Design: Colorectal cancers with KIT expression were characterized by immunoblotting and immunohistochemistry. The biologic alterations after KIT-SCF binding were analyzed with or without protein kinase C (PKC) activation.Results: We found that WT-KIT was expressed in a subset of colon cancer cell lines and was activated by SCF, leading to activation of downstream AKT and extracellular signal-regulated kinase (ERK) signaling pathways. We also showed that KIT expression gradually decreased, after prolonged SCF stimulation, due to lysosomal degradation. Degradation of WT-KIT after SCF binding was significantly rescued when PKC was activated. We also showed the involvement of activated PKC-delta in the recycling of WT-KIT. We further showed that a subset of colorectal cancers exhibit expressions of both WT-KIT and activated PKC-delta and that expression of KIT is correlated with poor patient survival (P = 0.004).Conclusions: Continuous downstream signal activation after KIT-SCF binding is accomplished through PKC-delta-mediated recycling of KIT. This sustained KIT activation may contribute to tumor progression in a subset of colon cancers with KIT expression and might provide the rationale for a therapeutic approach targeting KIT. (C) 2013 AACR.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000030226/2SEQ:2PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000030226ADJUST_YN:YEMP_ID:A076075DEPT_CD:3344CITE_RATE:7.837DEPT_NM:생명과학부SCOPUS_YN:YCONFIRM:
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