Dedifferentiated liposarcoma arising from the sigmoid mesocolon： A case report

Dedifferentiated liposarcoma is a variant of liposarcoma with a more aggressive course. It occurs most commonly in the retroperitoneum and rarely in other anatomic locations. In the present report, we describe a case of dedifferentiated liposarcoma that occurred in an unusual location, sigmoid mesocolon, which has not yet been documented.     

Potential role of p53 mutation in chemical hepatocarcinogenesis of rats

AIM: Inactivation of p53 gene is one of the most frequent genetic alterations in carcinogenesis. The mutation status of p53 gene was analyzed, in order to understand the effect of p53 mutation on chemical hepatocarcinogenesis of rats. METHODS: During hepatocarcinogenesis of rats induced by 3‘-methyl-4- dimethylaminoazobenzene (3‘-Me-DAB),prehepatocarcinoma and hepatocarcinoma foci were collected by laser capture microdissection (LCM), and quantitatively analyzed for levels of p53 mRNA by LightCyclerTM real-time RT-PCR and for mutations in p53 gene exons 5-8 by direct sequencing. RESULTS: Samples consisting of 44 precancerous foci and 24 cancerous foci were collected by LCM. A quantitative analysis of p53 mRNA showed that p53 mRNA peaked at an early stage (week 6) in the prehepatocarcinoma lesion, more than ten times that of adjacent normal tissue, and gradually decreased from week 6 to week 24. The expression of p53 mRNA in adjacent normal tissue was significantly lower than that in prehepatocarcinoma. Similar to prehepatocarcinoma,p53 mRNA in cancer was markedly higher than that in adjacent normal tissue at week 12, and was closer to normal at week 24. Direct p53 gene sequencing showed that 35.3%(24/68) (9 precancer, 15 cancer) LCM samples exhibited point mutations, 20.5% of prehepatocarcinoma LCM samples presented missense mutations at exon 6/7 or/and 8, and was markedly lower than 62.5% of hepatocarcinoma ones(P<0.01). Mutation of p53 gene formed the mutant hot spots at 5 codons. Positive immunostaining for p53 protein could be seen in prehepatocarcinoma and hepatocarcinoma foci at 24 weeks. CONCLUSION: p53 gene mutation is present in initial chemical hepatocarcinogenesis, and the mutation of p53 gene induced by 3‘-Me-DAB is an important factor of hepatocarcinogenesis.     

Potential role of p53 mutation in chemical hepatocarcinogenesis of rats

AIM:Inactivation of p53 gene is one of the most frequentgenetic alterations in carcinogenesis.The mutation statusof p53 gene was analyzed,in order to understand theeffect of p53 mutation on chemical hepatocarcinogenesisof rats.METHODS:During hepatocarcinogenesis of rats inducedby 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB),prehepatocarcinoma and hepatocarcinoma loci werecollected by laser capture microdissection (LCM),andquantitatively analyzed for levels of p53 mRNA byLightCycler~(TM) real-time RT-PCR and for mutations in p53 geneexons 5-8 by direct sequencing.RESULTS:Samples consisting of 44 precancerous foci and24 cancerous foci were collected by LCM.A quantitativeanalysis of p53 mRNA showed that p53 mRNA peaked at anearly stage (week 6) in the prehepatocarcinoma lesion,morethan ten times that of adjacent normal tissue,and graduallydecreased from week 6 to week 24.The expression of p53mRNA in adjacent normal tissue was significantly lower thanthat in prehepatocarcinoma.Similar to prehepatocarcinoma,p53 mRNA in cancer was markedly higher than that inadjacent normal tissue at week 12,and was closer to normalat week 24.Direct p53 gene sequencing showed that 35.3%(24/68) (9 precancer,15 cancer) LCM samples exhibitedpoint mutations,20.5% of prehepatocarcinoma LCM samplespresented missense mutations at exon 6/7 or/and 8,andwas markedly lower than 62.5% of hepatocarcinoma ones(P<0.01).Mutation of p53 gene formed the mutant hot spotsat 5 codons.Positive immunostaining for p53 protein couldbe seen in prehepatocarcinoma and hepatocarcinoma fociat 24 weeks.CONCLUSION:p53 gene mutation is present in initialchemical hepatocarcinogenesis,and the mutation of p53gene induced by 3'-Me-DAB is an important factor ofhepatocarcinogenesis.     

The point mutation of p53 gene exon7 in hepatocellular carcinoma from Anhui Province,a non HCC prevalent area in China

AIM：In hepatocellular carcinoma(HCC)prevalent areas of China,the point mutation of p53 exon7 is highly correlated with hepatitis B virus(HBV)infection and aflatoxin B intake While in non-HCC_prevalent areas of China,these factors are not so important in the etiology of HCC.Therefore,the point mutation of p53 exon7 may also be different than that in HCC-pervalent areas of China.The aim of this study is to investigate the status and carcinogenic role of the point mutation of p53 gene exon7 in hepatocellular carcinoma from Anhui Province,a non-HCC-prevalent area in China.METHODS:RCR,PCR-SSCP and PCR-RFLP were applied to analyze the homozygous deletion and point mutation of p53 exon7 in HCC samples from Anhui,which were confimed by DNA sequencing and Genbak comparison.RESULTS:In the 38 samples of hepatocellular carcinoma,no homozygous deletion of p53 exon7 was detected and point mutations of p53 exon7 were found in 4 cases,which were found to be heterozygous mutation of codon 249 with a mutation rate of 10.53%(4/38).The third base mutation(G→T)of p53 codon 249 was found by DNA sequencing and Genbank comparison.CONCLUSION:The incidence of point mutation of p53 codon 249 is lower in hepatocellular carcinoma and the heterozygous mutation of p53 exon7 found in these patients only indicate that they have genetic susceptibility to HCC p53 codon 249 is a hotspot of p53 exon7 point mutation suggesting that the point mutation of p53 exon 7 may not play a majuor role in the carcinogenesis of HCC in Anhui Province,a non-HCC-prevalent area in China.     

Co-mutation of p53, K-ras genes and accumulation of p53 protein and its correlation to clinicopathological features in rectal cancer

AIM: To determine bhe accuracy of p53 gene mutations predicted by overexpression of p53 protein immunohistochemically,and to investigate the co-mutation of p53 and K-ras genes in rectal cancer and its effect on promoting malignant biologic behaviors of tumors.METHODS: Ninety-seven specimens of rectal cancer were surgically resected in our hospital from August 1996 to October 1997. The hot mutation areas of p53 gene (in exons 5-8) and K-rasgene (in codon 5/12 and 13) were detected with polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), and overexpression of p53 protein was detected with immunohistochemistry (IHC) in the 97 specimens of rectal cancer. Correlation between gene mutations and tumor clinicopathologic factors was studied, and survival analysis was penfomed as well.RESULTS: There were 36 cases of p53 gene mutations in 61 p53 protein positive cases, and 21 cases of p53 gene non-mutation in 36 p53 protein negative cases respectively.The coincidence rate of p53 gene mutation by IHC method with PCR-SSCP method was 58.8% (57/97). The mutation rate of p53 gene was 52.6% (51/97), while K-ras gene mutation was observed in codons 12 and 13 in 61 cases with a mutation rate of 62.9% (61/97). Single gene mutation of p53 or K-raswas found in 32 cases. Both p53 and K-ras gene mutation were found in 48 cases. Statistical analysis showed that p53 and K-ras gene mutations were not related to the dinicopathologic factors, including tumor size, gross tumor type, histological dassification, differentiation, invasion to intestinal veins, lymphatics and nerves, invasive depth to.wall, lymph node metastasis, and Dukes‘ stages (P&gt;0.05).The survival in patients with no gene mutation, single gene mutation and both gene mutations were similar (P&gt;0.05).CONCLUSION: IHC has a certain false positive and false negative rate in detecting p53 gene mutations. Malignant biological behaviours of rectal cancer are not enhanced by p53 and K-rasgene mutations. Co-mutation of p53 and K-ras gene has neither synergic carcinogenesis-promoting effect,nor prognostic effect on rectal cancer.     

Liposarcoma of the stomach： A rare case report

Liposarcoma is the most common soft tissue sarcoma and accounts for 15%-20% of all mesenchymal malignancies. The tumor occurs most frequently in the limbs, retroperitoneum and rarely has a visceral location. We report a case of a gastric liposarcoma in a male patient. A 68 years old male patient was admitted to hospital for abdominal discomfort and fullness lasting for a month. He reported rare episodes of vomiting. The CT examination revealed a large epigastric mass （8 cm × 4 cm） involving the lesser curvature of the stomach, in contact with the pancreas and gallbladder. Fatty areas within the mass were evident. A total gastrectomy together with cholecystectomy was performed. The histopathological diagnosis was a well differentiated liposarcoma. The patient did not undergo any adjuvant treatment, he is under close follow up and two years later he is disease free. We report this case due to the rarity of this tumor in the stomach （nine cases reported in the literature）.     

Codon 249 mutation in exon 7 of p53 gene in plasma DNA： maybe a new early diagnostic marker of hepatocellular carcinoma in Qidong risk area, China

AIM: One of the characteristics of hepatocellular cardnoma(HCC) in Qidong area is the selective mutation resulting in a serine substitution at codon 249 of the p53 gene (1,20),and it has been identified as a “hotspot” mutation in heptocellular carcinomas occurring in populations exposed to afiatoxin and with high prevalence of hepatitis B virus carriers (2, 3, 9, 10, 16, 24). We evaluated in this paper whether this “hotspot” mutation could be detected in cellfree DNA drculating in plasma of patients with hepatocellular carcinoma and drrhosis in Qidong, China, and tried to illustrate the significance of the detection of this molecular biomarker.METHODS: We collected blood samples from 25 hepatocellular carcinoma patients, 20 cirrhotic patients and 30 healthy controls in Qidong area. DNA was extracted and purified from 200μl of plasma from each sample. The 249^Ser p53 mutation was detected by restriction digestion analysis and direct sequencing of exon-7 PCR products.RESULTS: We found in exon 7 of p53 gene G---T transversion at the third base of codon 249 resulting 249^Arg→249^Ser mutation in 10/25 (40%) hepatocellular carcinoma cases,4/20 (20%) cirrhotics, and 2/30 (7%) healthy controls.The adjusted odds ratio for having the mutation was 22.1(95% CI, 3.2-91.7) for HCC cases compared to controls.CONCLUSION: These data show that the 249^Ser p53 mutation in plasma is strongly associated with hepatocellular carcinoma in Qidong patients. We found this mutation was also detected, although it was at a much lower frequency,in plasma DNA of Qidong cirrhotics and healthy controls;We consider that these findings, together with the usual method of HCC diagnosis, will give more information in early diagnosis of HCC, and 249^Ser p53 mutation should be developed to a new early diagnostic marker for HCC.     

Induction of Apoptosis by Octreotide in Human Gastric Cancer Cells

Parvovirus H-1 has been a promising vector in human gene therapy of tumor. With a vector, pSHll8, a mutation was performed down the site of p38 promoter to change ATG codon into ACG, which leaves the NS 1 protein intact and ensures correct expression of the downstream report genes, such as enhanced green fluorescent protein (GFP) gene and wt p53 cDNA, in newly constructed H1 based vectors (pH1EG and pHI/p53). The vector, pH1EG,     

Mad2 and p53 expression profiles in colorectal cancer and its clinical significance

AIM: To investigate the expression of tumor suppressor gene p53 and spindle checkpoint gene Mad2, and to demonstrate their expression difference in colorectal cancer and normal mucosa and to evaluate its clinical significance.METHODS: Westemn blot and immunohistochemistry methods were used to analyze the expression of Mad2 in colorectal cancer and its corresponding normal mucosa. The expression of p53 was detected by immunohistochemistry method in colorectal cancer and its corresponding normal mucosa.RESULTS: Mad2 was significantly overexpressed in colorectal cancer compared with corresponding normal mucosa (P＜0.001), and it was not related to the differentiation of adenocarcinoma and other dinical factors (P＞0.05).The ratio of Mad2 protein in cancer tissue (C) to that in its normal mucosa tissue (N) was higher than 2, which was more frequently observed in patients with lymph gland metastasis (P＜0.05). p53 protein expression was not observed in normal mucosa. The rate of p53 positive expression in adenocarcinomas was 52.6%. There was a significant difference between adenocarcinomas and normal mucosa(P＜0.001), which was not related to the differentiation degree of adenocarcinoma and other clinical factors (P＞0.05).CONCLUSION: Defect of spindle checkpoint gene Mad2and mutation of p53 gene are involved mainly in colorectal carcinogenesis and C/N＞2 is associated with prognosis of colorectal cancer.     

Dedifferentiated liposarcoma of the rectum: A case report

Liposarcoma is one of the most common soft tissue sarcomas found in adults, and it usually occurs in the retroperitoneum and the extremities. Here, we describe a case of dedifferentiated liposarcoma originating from a well-differentiated liposarcoma of the mesorectum that presented as a protruding mass in the rectal lumen. Hartmann’s operation with total mesorectal excision was performed and the tumor was removed radically. No management guidelines are currently available for liposarcoma of the rectum. We propose that complete surgical resection be required for the treatment of rectal liposarcoma and that a long-term detailed follow up is necessary.     

肺癌患者肺组织和痰标本p53基因突变检测及其临床意义

目的　探讨肺癌患者支气管肺活检组织和痰标本中p5 3基因突变检测在肺癌诊断中意义。方法　应用聚合酶链反应 (PCR) 单链多肽性 (SSCP) 银染法检测 12 0例肺癌和 40例良性肺疾病支气管肺活检组织和痰标本p5 3基因第 5～ 8外显子突变情况。结果　 60例肺癌患者癌组织、癌旁组织和对侧支气管组织p5 3基因突变检出率分别为 60 % (3 6/ 60 )、17% (10 / 60 )和 5 % (3 / 60 ) ,三组间比较差异有显著性 (P <0 .0 0 5 )。 2 0例良性肺疾病支气管肺组织p5 3基因突变检出率为 5 %。故活检组织p5 3基因突变检出肺癌的敏感性为 60 % ,特异性为 95 % ;另外 60例肺癌痰标本p5 3基因突变检出的敏感性为 43 % (2 6/ 60 ) ,特异性为 10 0 %。肺癌痰标本p5 3基因突变联合细胞学检测使肺癌的诊断率从单纯细胞学的 48% (2 9/ 60 )提高到 68% (41/ 60 )。结论　痰标本p5 3基因检测联合细胞学检查可提高肺癌的诊断率     

Mutations of the p53 gene in adult T-cell leukemia.

The p53 tumor suppressor gene was examined by direct sequencing of polymerase chain reaction-amplified DNA from fresh tumor cells of 10 patients with adult T-cell leukemia (ATL). Samples included nine patients with acute or lymphomatous ATL, and one patient in whom samples were examined in both his acute and chronic stages of ATL. Four missense mutations and one silent point mutation in the coding region of the p53 gene were found in cells from five patients with either acute or lymphomatous ATL. The missense mutations were homozygous and occurred in evolutionarily highly conserved regions of p53. One patient had no p53 mutation in his leukemic cells during chronic phase of ATL, but had a homozygous point mutation at codon 273 (Arg to His) when he progressed to acute ATL. In summary, we show that p53 is frequently mutated in the acute phase of ATL and one informative case suggests that p53 mutations may be associated with the transition from chronic to acute ATL.     

p53、K-ras基因对大肠癌血管生成的调控作用

目的　探讨p53、K ras基因对大肠癌血管生成的调控作用。方法　用PCR 单链构像多态性分析 (SSCP)和免疫组织化学的方法研究 68例大肠癌和癌旁组织以及 2 0例正常组织p53、K ras基因突变及血管内皮生长因子 (VEGF)和微血管密度的表达情况。结果　大肠癌组中p53、K ras基因突变率及VEGF的表达明显高于癌旁组 ,2组的阳性率分别为 47 1 % ,44 1 % ,55 9% (32 /68,30 /68,38/68) ;1 3 2 % ,7 4% ,1 1 8% (9/68,5/68,8/68)。 2 0例正常组织中未检出p53、K ras基因突变及VEGF的阳性表达。VEGF的表达与大肠癌的血管生成和转移显著相关 (r =0 82 0 ,P <0 0 1 )。p53、K ras均与VEGF表达显著相关 (P <0 0 1 )。结论　p53、K ras基因可上调VEGF的表达 ,p53、K ras基因在调控大肠癌血管形成方面起重要作用     

Nonhereditary p53 mutations in T-cell acute lymphoblastic leukemia are associated with the relapse phase

We have previously reported that greater than 60% of human leukemic T- cell lines possess mutations in the p53 tumor suppressor gene. To determine whether T-cell acute lymphoblastic leukemia (T-ALL) patient samples possess p53 mutations, we screened peripheral blood-and bone marrow-derived leukemia samples, taken at diagnosis and at relapse, for p53 mutations. Exons 4 through 9 and selected intron regions of the p53 gene were analyzed using polymerase chain reaction-single-strand conformation polymorphism and direct sequencing. p53 mutations were found in 0 of 15 T-ALL diagnosis samples, as compared with 10 of 36 (28%) T-ALL relapse samples. To determine whether p53 mutations play a role in the recurrence (relapse) of T-ALL, two special groups of T-ALL patients were studied: (1) a group of 8 relapse patients whose disease was refractory to chemotherapeutic treatment, and (2) a group of 6 "paired" T-ALL cell samples from patients for whom we possess both diagnosis and relapse samples. Three of 8 relapsed patients (37.5%) whose disease was refractory to the reinduction of remission by chemotherapy possessed missense mutations of the p53 gene. All 3 cases had mutations in exon 5. Among the paired samples, 3 of 6 patients harbored p53 mutations at disease recurrence, but possessed only wild- type p53 alleles at diagnosis. One case had mutation on exon 4, 1 case in exon 5, and 1 case in exon 8 with loss of heterozygosity. These data clearly indicate that recurrence of T-ALL is associated with missense mutations in p53. Our results indicate that (1) mutations of p53 do occur in T-ALL in vivo, and such mutations are associated with the relapse phase of the disease; and (2) p53 mutation is involved in the progression of T-ALL. This conclusion is supported by our observation that the introduction of T-ALL-derived mutant p53 expression constructs into T-ALL cell lines further increases their growth rate in culture, enhances cell cloning in methylcellulose, and increases tumor formation in nude mice.     

Identification of a germ-line mutation in the p53 gene in a patient with an intracranial ependymoma.

We detected a germ-line mutation of the p53 gene in a patient with a malignant ependymoma of the posterior fossa. This mutation, which was found at codon 242, resulted in an amino acid substitution in a highly conserved site of exon 7 of the p53 gene; the same mutation was found in both the germ-line and the tumor tissue. This is the most common region of previously described somatic p53 mutations in tumor specimens and of the germ-line p53 mutations in patients with the Li-Fraumeni cancer syndrome. Evaluation of the patient's family revealed several direct maternal and paternal relatives who had died at a young age from different types of cancer. The association of a germ-line p53 mutation with an intracranial malignancy and a strong family history of cancer suggests that p53 gene mutations predispose a person to malignancy and, like retinoblastoma mutations, may be inherited.     

腹膜后伴有异源性分化的去分化脂肪肉瘤病例分析及文献复习

目的：探讨腹膜后伴有异源性横纹肌肉瘤和神经内分泌分化的去分化脂肪肉瘤分子遗传学特征、临床病理特点、诊断和鉴别诊断。方法回顾性分析1例伴有异源性横纹肌肉瘤和神经内分泌分化的去分化脂肪肉瘤临床病理过程、免疫组织化学、组织形态学特点、诊断,并结合文献复习。结果光镜下肿瘤由两种不同分化成分和形态结构组成,分化成分为分化良好的脂肪瘤样脂肪肉瘤及炎症性、黄色肉芽肿性成分;去分化成分为高度恶性的多形性未分化肉瘤及低度恶性的侵袭性纤维瘤病和黏液纤维肉瘤样成分。去分化成分中可见异源性横纹肌肉瘤及神经内分泌分化。免疫组化：Viment （＋）;CD68（＋）;CDK4（＋）;FLi-1（＋）;MyOD1（＋）;Myogenin（＋）;NSE （＋）;CD56（＋）;CgA （＋/-）;Syn （＋/-）;Bcl-2（＋）;S-100（＋/-）;CD99（＋/-）;Desim（＋）;CD34（-）;LCA（-）;MDM2（-）;CK-AE1/AE3（-）;Ki-67阳性增殖指数＞60％。结论发生在腹膜后的巨大肿瘤,在同一肿瘤内存在两种不同分化成分和形态结构,并伴有异源性成分分化,其复杂性、多形性常造成诊断困难。因此,掌握临床病理及免疫组化特点对该病的诊断和鉴别诊断具有重要意义。     

Detection of human papillomavirus DNA and p53 gene mutations in esophageal cancer samples and adjacent normal mucosa

BACKGROUND/AIM: There is evidence of a possible etiological role of human papillomaviruses (HPVs) in the development of esophageal tumors. Loss of function of the wild-type p53 tumor suppressor gene product by binding to E6 oncoproteins of high-risk HPVs is considered an important event in tumor development. The aim of this study was to verify the prevalence of HPV infection and p53 mutation in esophageal tumor tissue samples and in the adjacent normal mucosa in patients from a high-risk area in Italy. METHODS: DNA from 33 biopsy specimens (17 tumor sample biopsies and 16 samples of adjacent normal mucosa) was screened for HPV DNA using two polymerase chain reaction based procedures. Restriction fragment length polymorphism analysis was used for typing. Screening of p53 mutations was performed with polymerase chain reaction-single strand conformation polymorphism analysis and DNA sequencing. RESULTS: Overall, 8 of 17 patients presented HPV DNA; HPV 16 was detected in 4 of 8 samples. Samples from tumors and adjacent mucosa were positive for mucosal HPVs in 7 of 17 and 4 of 16 cases, respectively. In 1 case, HPV DNA was detected in the normal mucosa only. None of the samples contained HPVs of the epidermodysplasia verruciformis or cutaneous groups. Mutations of p53 were detected in two HPV DNA negative samples. In both cases, the mutation was present in the tumor only. CONCLUSIONS: Our results are in favor of the involvement of both aberrant p53 expression and HPV infection in the development of esophageal tumors. The high HPV infection rate in patients from a high-risk region suggests that subjects harboring HPVs (in particular HPV 16) in the esophagus should be considered at risk of esophageal malignancies.     

Molecular and biological analysis of carcinoma of the small intestine: beta-catenin gene mutation by interstitial deletion involving exon 3 and replication error phenotype

The genetic mechanisms of carcinomas of the small intestine are not well understood. We report the results of analysis of genetic alterations in a case of small intestinal carcinoma. A tumor in the terminal ileum was resected in a 59-yr-old woman. Histologically, the tumor was classified as well-differentiated adenocarcinoma. We screened for genetic alterations in adenomatous polyposis coli (APC), beta-catenin, K-ras, and p53 genes, as well as microsatellite instability, which are known to be involved in colorectal tumorigenesis. The tumor exhibited somatic interstitial deletion of 425-bp, which included the entire exon 3 in beta-catenin gene. Immunohistochemical staining confirmed accumulation of aberrant beta-catenin protein in the cytoplasm and nuclei of the malignant tissue. Furthermore, a frameshift mutation in the transforming growth factor beta receptor type II gene with replication error phenotype was detected in the tumor DNA. In contrast, no genetic alterations were found in the APC, K-ras, and p53 genes. Our results suggested that both beta-catenin gene mutation and replication error phenotype might contribute to carcinogenesis of the small intestinal tumor in our case. This is the first report that activation of beta-catenin gene by somatic gene mutation is involved in the development of carcinoma of the small intestine.