AIM： To detect germline mutations of MLH1, and investigate microsatellite instability and expression of MLH1 in tumor tissues of hereditary non-polyposis colorectal cancer （HNPCC） with two novel germline mutations,...AIM： To detect germline mutations of MLH1, and investigate microsatellite instability and expression of MLH1 in tumor tissues of hereditary non-polyposis colorectal cancer （HNPCC） with two novel germline mutations, and further investigate the pathobiology of the two novel mutations of MLH1. METHODS： RNA was extracted from the peripheral blood of 12 patients from 12 different families that fulfilled the Amsterdam 11 Criteria for HNPCC. Germline mutations of MLH1 were determined by RT-PCR, followed by cDNA sequencing analysis. PCR-GeneScan analysis was used to investigate microsatellite instability with a panel of five microsatellite markers （BAT26, BAT25, D5S346, D2S123 and mfd15）, along with immunohistochemical staining to detect the expression of MLH1 protein in two patients＇ tumor tissues with novel mutations. RESULTS： Three germline mutations were found in four patients, one of the mutations has previously been reported, but the other two, CGC→TGC at codon 217 of exon 8 and CCG→CTG at codon 581 of exon 16, have not been reported. The two patients＇ tumor tissues with novel mutations had high-frequency microsatellite instability that showed more than two unstable loci, and both tumors lost their MLH1 protein expression. CONCLUSION： The two novel germline mutations of MLH1 in HNPCC families i.e. CGC→TGC at codon 217 of exon 8 and CCG→CTG at codon 581 of exon 16, are very likely to have pathological significance.展开更多
BACKGROUND The development of colorectal cancer(CRC) is a complicated multistep process that involves an accumulation of mutations in tumor suppressor genes and oncogenes.In the process of DNA replication, base mismat...BACKGROUND The development of colorectal cancer(CRC) is a complicated multistep process that involves an accumulation of mutations in tumor suppressor genes and oncogenes.In the process of DNA replication, base mismatch often occurs due to various factors leading to abnormal expression of mismatch repair genes(MMR),among which MLH1 and MSH2 are the most important.Recently, numerous studies indicated that MLH1/MSH2 phenotype is associated with CRC.We wanted to elucidate the role of MLH1/MSH2 in the prediction and prognosis of CRC through long-term clinical observation.AIM To evaluate the prognostic and predictive significance of MLH1/MSH2 in patients with stage Ⅱ-Ⅲ CRC using immunohistochemical analysis and GeneScan.METHODS Specimens from 681 patients with CRC(395 stage Ⅱ and 286 stage Ⅲ, 387 males and 294 females) who underwent curative surgical resection from 2013 to 2016 were tested.Immunohistochemistry was used to analyze MMR status and the microsatellite status of 133 patients was determined by GeneScan analysis.RESULTS Five hundred and fifty(80.76%) patients were MLH1/MSH2 positive and 131(19.24%) were negative by immunohistochemistry.MLH1/MSH2-positive tumors were significantly more frequent in the colon than in the rectum, and had poor differentiation and less mucin production(P < 0.05).Patients of different groups did not differ in terms of age, gender, tumor size, tumor stage, lymphocytic infiltration, or circumscribed margin.MLH1/MSH2-negative patients had a more favorable OS than MLH1/MSH2-positive patients(P < 0.001).Univariate and multivariate analyses demonstrated MLH1/MSH2 expression as an independent prognostic and predictive factor for stage Ⅱ/Ⅲ CRC.MLH1/MSH2 expression was a strong prognostic factor in all patients [P < 0.001, hazard ratio(HR) = 4.064,95%CI: 2.241–7.369].Adjuvant chemotherapy had a greater correlation with survival advantage in MLH1/MSH2-negative patients with stage Ⅲ disease(P <0.001, HR = 7.660, 95%CI: 2.974–15.883).However, patients with stage Ⅱ disease or MLH1/MSH2-positive patients with stage Ⅲ disease did not benefit from adjuvant chemotherapy.GeneScan analysis demonstrated that among 133 patients, 105(78.95%) were microsatellite stable, and 28(21.05%) had microsatellite instability(MSI), including 18(13.53%) with high MSI and 10(7.52%) with low MSI.This is consistent with the immunohistochemical results.CONCLUSION MLH1/MSH2 phenotype constitutes a pathologically and clinically distinct subtype of sporadic CRC.MLH1/MSH2 is an independent prognostic and predictive factor for outcome of stage Ⅱ-Ⅲ CRC.展开更多
BACKGROUND Lynch syndrome(LS)is an autosomal dominant hereditary disorder because of germline mutations in DNA mismatch repair genes,such as MutL homolog 1(MLH1),PMS1 homolog 2,MutS homolog 2,and MutS homolog 6.Gene m...BACKGROUND Lynch syndrome(LS)is an autosomal dominant hereditary disorder because of germline mutations in DNA mismatch repair genes,such as MutL homolog 1(MLH1),PMS1 homolog 2,MutS homolog 2,and MutS homolog 6.Gene mutations could make individuals and their families more susceptible to experiencing various malignant tumors.In Chinese,MLH1 germline mutation c.(453+1_454-1)_(545+1_546-1)del-related LS has been infrequently reported.Therefore,we report a rare LS patient with colorectal and endometrioid adenocarcinoma and describe her pedigree characteristics.CASE SUMMARY A 57-year-old female patient complained of irregular postmenopausal vaginal bleeding for 6 mo.She was diagnosed with LS,colonic malignancy,endometrioid adenocarcinoma,secondary fallopian tube malignancy,and intermyometrial leiomyomas.Then,she was treated by abdominal hysterectomy,bilateral oviduct oophorectomy,and sentinel lymph node resection.Genetic testing was performed using next-generation sequencing technology to detect the causative genetic mutations.Moreover,all her family members were offered a free genetic test,but no one accepted it.CONCLUSION No tumor relapse or metastasis was found in the patient during the 30-mo followup period.The genetic panel sequencing showed a novel pathogenic germline mutation in MLH1,c.(453+1_454-1)_(545+1_546-1)del,for LS.Moreover,cancer genetic counseling and testing are still in the initial development state in China,and maybe face numerous challenges in the further.展开更多
基金the Key Project of Shanghai Medical Subjects,No.05Ⅲ004 and Shanghai Pujiang Program,No.06PJ14019
文摘AIM： To detect germline mutations of MLH1, and investigate microsatellite instability and expression of MLH1 in tumor tissues of hereditary non-polyposis colorectal cancer （HNPCC） with two novel germline mutations, and further investigate the pathobiology of the two novel mutations of MLH1. METHODS： RNA was extracted from the peripheral blood of 12 patients from 12 different families that fulfilled the Amsterdam 11 Criteria for HNPCC. Germline mutations of MLH1 were determined by RT-PCR, followed by cDNA sequencing analysis. PCR-GeneScan analysis was used to investigate microsatellite instability with a panel of five microsatellite markers （BAT26, BAT25, D5S346, D2S123 and mfd15）, along with immunohistochemical staining to detect the expression of MLH1 protein in two patients＇ tumor tissues with novel mutations. RESULTS： Three germline mutations were found in four patients, one of the mutations has previously been reported, but the other two, CGC→TGC at codon 217 of exon 8 and CCG→CTG at codon 581 of exon 16, have not been reported. The two patients＇ tumor tissues with novel mutations had high-frequency microsatellite instability that showed more than two unstable loci, and both tumors lost their MLH1 protein expression. CONCLUSION： The two novel germline mutations of MLH1 in HNPCC families i.e. CGC→TGC at codon 217 of exon 8 and CCG→CTG at codon 581 of exon 16, are very likely to have pathological significance.
基金Supported by Medical Science and Technology Development Foundation,Nanjing Department of Health,No.YKK14140(to ShuiMing Wang)and No.ZKX15040(to Bin Jiang)Project of Administration of Traditional Chinese Medicine of Jiangsu Province of China,No.LZ11101(to Zhi-Ming Fang)
文摘BACKGROUND The development of colorectal cancer(CRC) is a complicated multistep process that involves an accumulation of mutations in tumor suppressor genes and oncogenes.In the process of DNA replication, base mismatch often occurs due to various factors leading to abnormal expression of mismatch repair genes(MMR),among which MLH1 and MSH2 are the most important.Recently, numerous studies indicated that MLH1/MSH2 phenotype is associated with CRC.We wanted to elucidate the role of MLH1/MSH2 in the prediction and prognosis of CRC through long-term clinical observation.AIM To evaluate the prognostic and predictive significance of MLH1/MSH2 in patients with stage Ⅱ-Ⅲ CRC using immunohistochemical analysis and GeneScan.METHODS Specimens from 681 patients with CRC(395 stage Ⅱ and 286 stage Ⅲ, 387 males and 294 females) who underwent curative surgical resection from 2013 to 2016 were tested.Immunohistochemistry was used to analyze MMR status and the microsatellite status of 133 patients was determined by GeneScan analysis.RESULTS Five hundred and fifty(80.76%) patients were MLH1/MSH2 positive and 131(19.24%) were negative by immunohistochemistry.MLH1/MSH2-positive tumors were significantly more frequent in the colon than in the rectum, and had poor differentiation and less mucin production(P < 0.05).Patients of different groups did not differ in terms of age, gender, tumor size, tumor stage, lymphocytic infiltration, or circumscribed margin.MLH1/MSH2-negative patients had a more favorable OS than MLH1/MSH2-positive patients(P < 0.001).Univariate and multivariate analyses demonstrated MLH1/MSH2 expression as an independent prognostic and predictive factor for stage Ⅱ/Ⅲ CRC.MLH1/MSH2 expression was a strong prognostic factor in all patients [P < 0.001, hazard ratio(HR) = 4.064,95%CI: 2.241–7.369].Adjuvant chemotherapy had a greater correlation with survival advantage in MLH1/MSH2-negative patients with stage Ⅲ disease(P <0.001, HR = 7.660, 95%CI: 2.974–15.883).However, patients with stage Ⅱ disease or MLH1/MSH2-positive patients with stage Ⅲ disease did not benefit from adjuvant chemotherapy.GeneScan analysis demonstrated that among 133 patients, 105(78.95%) were microsatellite stable, and 28(21.05%) had microsatellite instability(MSI), including 18(13.53%) with high MSI and 10(7.52%) with low MSI.This is consistent with the immunohistochemical results.CONCLUSION MLH1/MSH2 phenotype constitutes a pathologically and clinically distinct subtype of sporadic CRC.MLH1/MSH2 is an independent prognostic and predictive factor for outcome of stage Ⅱ-Ⅲ CRC.
基金Supported by the Natural Science Fund of Science and Technology Department,Jilin,No.20180101010JCJilin Provincial Department of Education,No.JJKH20201049KJ.
文摘BACKGROUND Lynch syndrome(LS)is an autosomal dominant hereditary disorder because of germline mutations in DNA mismatch repair genes,such as MutL homolog 1(MLH1),PMS1 homolog 2,MutS homolog 2,and MutS homolog 6.Gene mutations could make individuals and their families more susceptible to experiencing various malignant tumors.In Chinese,MLH1 germline mutation c.(453+1_454-1)_(545+1_546-1)del-related LS has been infrequently reported.Therefore,we report a rare LS patient with colorectal and endometrioid adenocarcinoma and describe her pedigree characteristics.CASE SUMMARY A 57-year-old female patient complained of irregular postmenopausal vaginal bleeding for 6 mo.She was diagnosed with LS,colonic malignancy,endometrioid adenocarcinoma,secondary fallopian tube malignancy,and intermyometrial leiomyomas.Then,she was treated by abdominal hysterectomy,bilateral oviduct oophorectomy,and sentinel lymph node resection.Genetic testing was performed using next-generation sequencing technology to detect the causative genetic mutations.Moreover,all her family members were offered a free genetic test,but no one accepted it.CONCLUSION No tumor relapse or metastasis was found in the patient during the 30-mo followup period.The genetic panel sequencing showed a novel pathogenic germline mutation in MLH1,c.(453+1_454-1)_(545+1_546-1)del,for LS.Moreover,cancer genetic counseling and testing are still in the initial development state in China,and maybe face numerous challenges in the further.
