OBJECTIVE: To explore the significance of hMSH2 aberrant expression in patients with sporadic colorectal cancer in Xinjiang Uygur Autonomous Region. METHODS: Clinicopathological parameters and postoperative samples of 327 patients with sporadic colorectal cancer were collected in Xinjiang Uygur Autonomous Region. Immunohistochemistry PV-9000 two-step method was performed to measure hMSH2 expression in the postoperative pathologic specimens. Prognostic value of hMSH2 expression was evaluated. RESULTS: Thirty-five (10.7%) patients showed aberrant nuclear staining of hMSH2 expression. The patients with aberrant expression of hMSH2 showed better prognosis than the normal expression group, with significant difference (P<0.05). CONCLUSION In Xinjiang, aberrant hMSH2 expression can be regarded as an independent prognostic factor in patients with sporadic colorectal cancer.
Colorectal Neoplasms ; genetics ; metabolism ; Humans ; Immunohistochemistry ; MutS Homolog 2 Protein ; genetics ; metabolism ; Prognosis

OBJECTIVETo investigate the expression difference of DNA mismatch repair gene hMLH1 and hMSH2 between schistosomiasis-associated colorectal cancer and sporadic colorectal cancer.

METHODClinical and pathological data of colorectal cancer patients receiving operations in Zhejiang Cancer Hospital between January 2008 and December 2010 were retrospectively analyzed. Patients were divided into schistosomiasis group(n=80) and sporadic group (n=258) according to the preoperative history and pathologic results. Pathological specimens were collected and tissue chips were made to analyze the expression of hMLH1 and hMSH2 by immunohistochemistr.

RESULTSCompared with sporadic group, older age [(62.2 ± 9.6) year vs. (57.2 ± 11.7) year, P=0.000)], lower platelet level [(197.0 ± 59.6) × 10(9)/L vs. (217.0 ± 84.3) × 10(9)/L, P=0.02] and lower WBC level [(5.9 ± 1.9) × 10(9)/L vs. (6.6 ± 2.8) × 10(9)/L, P=0.02] were found in schistosomiasis group. Ratio of low differentiation-undifferentiation tumor was significantly higher in schistosomiasis group [44.2% (34/77) vs. 4.9% (12/247), P<0.05]. Lower positive rate of hMLH1 expression [77.5% (62/80) vs. 98.1% (253/258), P=0.000] and hMSH2 expression [75.0% (60/80) vs. 95.3% (246/258), P=0.000] was found in schistosomiasis group compared with sporadic group. Concurrent schistosomiasis was one of the risk factors of hMLH1/hMSH2 deficiency (RR: 0.913, 95% CI: 0.836-0.997, P=0.043), but not an independent factor (RR: 0.951, 95% CI: 0.867-1.043, P=0.286).

CONCLUSIONSchistosomiasis is associated with lower positive expression of hMLH1 and hMSH2, which indicates that hMLH1/hMSH2 deficiency may be a potential mechanism of schistosomiasis inducing carcinogenesis of colorectal cancer.

Adaptor Proteins, Signal Transducing ; Colorectal Neoplasms ; DNA Mismatch Repair ; Humans ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; Nuclear Proteins ; Polymerase Chain Reaction ; Schistosomiasis

Objective: To investigate the relationship between the expression of four mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) and NTRK genetic fusions in colorectal cancer. Methods: The paraffin-embedded tissue blocks of 830 cases of colorectal cancer were collected at the Affiliated Drum Tower Hospital, Nanjing University Medical School, China, from 2015 to 2019. Immunohistochemical and fluorescence in situ hybridization(FISH) method were used respectively to detect the expression of mismatch repair proteins and the break-apart of NTRKs; and the relationship between the expression of mismatch repair proteins and the NTRK genetic fusions was analyzed. Results: The overall mismatch repair protein deficiency (dMMR) rate was 9.88% (82/830), the mismatch repair proteins proficiency (pMMR) rate was 90.12%(748/830). The total deficiency rate of MLH1 protein was 9.04% (75/830), hPMS2 protein deficiency rate was 9.04% (75/830), MSH2 protein deficiency rate was 2.53% (21/830), MSH6 protein deficiency rate was 4.10% (34/830), the deficiency rate of synchronous MLH1 and PMS2 were 8.67% (72/830) and the deficiency rate of synchronous MSH2 and MSH6 were 2.17% (18/830). The dMMR group was associated with tumor location, different histological subgroups, tumor differentiation, AJCC stage and N stage (P<0.05). There were six cases (7.32%) carrying NTRK fusion by FISH among the 82 cases of dMMR, but only seven cases (0.94%) carrying NTRK fusion among the 748 cases of PMMR. The NTRKs translocation by FISH in all 13 cases were further confirmed by next generation sequencing. Among the clinicopathological characteristics, only differentiation showed significant difference between NTRK fusion positive and negative groups (P<0.05). More importantly, NTRK fusion was enriched in dMMR group (7.32% vs. 0.94%). Conclusion: In dMMR colorectal cancer group, the prevalence of NTRK fusion is higher than that in pMMR group.
Colonic Neoplasms ; Colorectal Neoplasms/genetics* ; DNA Mismatch Repair/genetics* ; Humans ; In Situ Hybridization, Fluorescence ; Mismatch Repair Endonuclease PMS2/metabolism* ; MutL Protein Homolog 1/metabolism* ; MutS Homolog 2 Protein/metabolism*

OBJECTIVE: To determine the ratio of deficient mismatch repair (dMMR) proteins and Lynch syndrome among patients undergoing colorectal cancer resection. METHODS: From June 2014 to May 2016, immunohistochemistry for mismatch repair proteins including mutL homolog 1 (MLH1), mutS homolog 2 (MSH2), mutS homolog 6 (MSH6) and PMS1 homolog 2 (PMS2) were carried out on 207 surgically resected specimens. Samples with lost expression of MMR proteins underwent genetic testing. RESULTS: Loss of expression of MMR proteins were found among 21 patients and accounted for 10.14% of the colorectal cancers. dMMR was more common in patients ≤50 years old, or with proximal tumor at splenic flexure and mucinous adenocarcinoma. Ten patients underwent genetic testing, with three pathogenic mutations (MSH6 c.3013C>T, MLH1 c.199G>A and a novel MSH6 c.584delT) and four ambiguous mutations identified. At least 1.4% of the colorectal cancers were diagnosed as Lynch syndrome. CONCLUSION Routine screening for Lynch syndrome among patients with colorectal cancer with MMR protein immunohistochemistry as preliminary screening method and MMR gene sequencing as diagnostic method is effective and feasible. It can reduce missed diagnosis of Lynch syndrome and bring lifelong benefit to patients and their families.
Adolescent ; Colorectal Neoplasms, Hereditary Nonpolyposis ; Early Detection of Cancer ; Humans ; Immunohistochemistry ; Middle Aged ; Mismatch Repair Endonuclease PMS2 ; MutS Homolog 2 Protein

OBJECTIVETo use a hospital-based case-control study design to investigate the relationship between hepatocellular carcinoma (HCC) and the interaction of polymorphisms in the human mismatch repair gene,hMSH2,with environmental factors.

METHODSCases of new-onset,histopathology-diagnosed,and untreated (no chemotherapy or radiation therapy) HCC were enrolled between September 2009 and September 2012.A non-HCC healthy control group was also enrolled and was composed of individuals living in the same region as the cases for more than 10 years and age-/sex-matched with similar socioeconomic characteristics.All enrollees underwent hMSH2 genotyping by real-time PCR.T-test,chi-square test and unconditional logistic regression analysis was used to analyze the difference in allele frequencies among the case and control groups and the relationship between hMSH2 polymorphisms and environmental factors.

RESULTSFrequencies of hMSH2 rs2303428 CC,CT and TT genotypes in the HCC group were significantly different than in the control group (14.13% vs.8.21%,47.02% vs.49.47%,and 38.85% vs.42.32%;x 2=8.289,P =0.016).Individuals carrying the hMSH2 rs2303428 T allelic gene had a significantly increased risk compared to those with the hMSH2 rs2303428 C allelic gene (adjusted OR=1.228).Interactions were found between the hMSH2 genotype and hepatitis B surface antigen (HBsAg)-positive hepatitis infection (adjusted OR=1.865) and history of cancer (adjusted OR=5.634).There was no relation between hMSH2 gene rs4952887 and rs2059520 and liver cancer development or interaction with environmental factors.

CONCLUSIONThe hMSH2 rs2303428 genotype is positively related to risk of HCC in Chinese,with HBsAg-positive hepatitis infection starus and history of cancer increasing the risk.

Alleles ; Carcinoma, Hepatocellular ; genetics ; Case-Control Studies ; Female ; Gene Frequency ; Genotype ; Humans ; Liver Neoplasms ; genetics ; Male ; MutS Homolog 2 Protein ; genetics ; Polymorphism, Genetic ; Real-Time Polymerase Chain Reaction

The purpose of this study was to investigate the molecular mechanism by which miR-21 and its target genes mediate radiation resistance of glioblastoma cells. Real-time PCR was employed to detect miR-21 expression in normal brain tissues, glioblastoma tissues and glioblastoma cell lines (A172, T98G and U87MG). T98G cells were transfected with anti-miR-21 oligonucleotides, or plasmids containing PDCD4 or hMSH2 (PDCD4-pcDNA3 and hMSH2-pcDNA3). The survival curve was obtained to investigate the sensitivity of T98G cells to radiation. Cell apoptosis was measured by using the Caspase-3/7 kit and cell cycle by flow cytometry. Western blotting was performed to detect the expression of hMSH2 and PDCD4 in miR-21-inhibiting T98G cells. The results showed that miR-21 expression in glioblastoma cells and tissues was conversely associated with the radiation sensitivity. Over-expression of miR-21 resulted in radiation resistance, while knockdown of miR-21 led to higher sensitivity of glioblastma cells to radiation. After miR-21 knockdown, the apoptosis of T98G cells was significantly increased and the G(2) phase arrest was more significant. In addition, miR-21 knockdown increased the expression of endogenous PDCD4 and hMSH2, which contributed to the apoptosis and G(2) arrest of T98G cells. The findings suggested that miR-21 may mediate the resistance of glioblastoma cells against radiation via its target genes PDCD4 and hMSH2. MiR-21 and its target genes may be used as potential molecular targets for clinical radiotherapy sensitization in the future.
Apoptosis Regulatory Proteins ; genetics ; Cell Line, Tumor ; Glioblastoma ; genetics ; Humans ; MicroRNAs ; genetics ; MutS Homolog 2 Protein ; genetics ; RNA-Binding Proteins ; genetics ; Radiation Tolerance ; genetics

OBJECTIVE: To establish a genetic diagnosis method for a novel MSH2 mutation. METHODS: A specific primer on the mutated site of MSH2 was synthesized and PCR was conducted using the specific primer and another downstream primer. PCR products were electrophoresed and then the carriers with the novel gene mutation of the carriers or non-carriers were identified. RESULTS: MSH2 in a hereditary nonpolyposis colorectal cancer family were successfully found. CONCLUSION The method is effective and simple for genetic diagnosis of the novel mutation in MSH2.
Base Sequence ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; DNA Mutational Analysis ; methods ; Female ; Humans ; Male ; Molecular Sequence Data ; MutS Homolog 2 Protein ; genetics ; Pedigree ; Point Mutation ; Polymerase Chain Reaction

OBJECTIVETo gain an insight into large genomic deletions in mismatch repair genes MSH2 and MLH1 in Chinese hereditary nonpolyposis colorectal cancer (HNPCC) patients in order to improve genetic detections of HNPCC kindreds.

METHODSFourteen peripheral blood DNA samples were obtained from 14 unrelated HNPCC patients, and fluorescent labeled quantitative multiplex PCR was used to detect large genomic deletions in MSH2 and MLH1 genes.

RESULTSOne of the fourteen probands, a man, was found to have MSH2 exon 1-7 deletions. His cancer-distressed son was also found to have the mutations. Additionally, three normal members of the family had the same mutations.

CONCLUSIONLarge genomic deletions which mainly present to MSH2 account for 20% of general pathological sequence changes of MSH2 and MLH1 genes in Chinese HNPCC patients, and large genomic detections of mismatch repair genes should be included in the regular genetic detections of Chinese HNPCC kindreds.

Adaptor Proteins, Signal Transducing ; genetics ; Asian Continental Ancestry Group ; genetics ; China ; Colorectal Neoplasms, Hereditary Nonpolyposis ; ethnology ; genetics ; pathology ; Female ; Humans ; Male ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; Nuclear Proteins ; genetics ; Pedigree ; Polymerase Chain Reaction ; Sequence Deletion

OBJECTIVETo gain an insight into the large intragenic hMSH2 and hMLH1 deletions in Chinese hereditary nonpolyposis colorectal cancer (HNPCC) families.

METHODThe large intragenic hMSH2 and hMLH1 deletions in 17 probands of HNPCC families were detected with multiplex ligation-dependent probe Three large intragenic hMSH2 deletions of examplification (MLPA) and GeneMapper techniques.

RESULTSon 8, exon 1-6, and exon 1-7 were found in three families respectively, and no hMLH1 deletion was found. The deletions accounted for 19% of the total hMSH2 and hMLHI germline pathogenic mutations.

CONCLUSIONSThe incidence of large intragenic mismatch repair (MMR) genes deletions is relatively higher in Chinese families, and hMSH2 deletions may be more common. It is necessary to detect the large intragenic MMR genes deletions in the molecular detection of HNPCC.

Adaptor Proteins, Signal Transducing ; genetics ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; Female ; Gene Deletion ; Humans ; Male ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; Nuclear Proteins ; genetics ; Nucleic Acid Amplification Techniques ; methods ; Pedigree

OBJECTIVETo study the protein expression pattern of DNA mismatch repair genes hMSH(2), hMLH(1) and the microsatellite instability (MSI) status in the tumor tissue from hereditary nonpolyposis colorectal cancer in the Chinese.

METHODSFifty-eight families fulfilling different clinical criteria including Amsterdam Criteria (AC) (22/24 families, 38 tumors), Japanese Criteria (JC) (12/15 families, 16 tumors) and Bethesda Guidelines (BG) (12/19 patients, 13 tumors) were studied. Monoclonal antibodies against hMSH(2), hMLH(1) proteins and a panel of microsatellite markers (5 loci) including BAT26, BAT25, D2S123, D5S346 and D17S250 were used for study.

RESULTSMSI-H was identified in all 22 (100%) AC tumors, with 81.8% (18/22) showing altered hMSH(2) or hMLH(1) expression; in 14/15 (93.8%) JC cancer, 1/1 (100%) JC adenoma, with 45.5% (5/11) showing altered hMSH(2) or hMLH(1) expression; and in 7/13 (53.8%) BG tumors, with 4/7 showing loss of hMSH(2) or hMLH(1) gene expression.

CONCLUSIONThe frequency of MSI-H and loss of mismatch repair protein are different in the families fulfilling different clinical criteria. Amsterdam Criteria and Japanese Criteria are the two most useful criterion systems for identifying mismatched repair defective tumors. However, Bethesda Guidelines should also be used for detecting more such tumors. The combination of immunohistochemical methods and microsatellite instability analysis is an effective strategy to detect the mismatch repair defective tumors. A close correlation does exist between hMSH(2), hMLH(1) protein expression pattern and MSI status.

Adaptor Proteins, Signal Transducing ; Base Pair Mismatch ; Carrier Proteins ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; DNA Repair ; DNA-Binding Proteins ; Humans ; Immunohistochemistry ; Microsatellite Repeats ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; Neoplasm Proteins ; genetics ; Nuclear Proteins ; Proto-Oncogene Proteins ; genetics