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

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

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

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 investigate the frequency of large fragment aberrations of MSH2 and MLH1 genes from Chinese colorectal cancer (CRC) patients with family history.

METHODSSixteen exons of MSH2, nineteen exons of MLH1 and seven DNA sequences from the other genes of the samples were screened and checked by multiplex ligation dependent probe amplification (MLPA). First, the methodology was confirmed by testing the positive and negative control samples. Then, 32 CRC or hereditary nonpolyposis colorectal cancer (HNPCC) patients with family history and 20 cases of sporadic CRC were applied to investigate for the large fragment aberrations of MSH2 and MLH1 genes.

RESULTSThe genomic DNA fragment deletions of all positive controls were identified and verified by MLPA. Three cases of 32 familial (hereditary) CRC/HNPCC were detected and identified to be the germline heterozygous deletions of MSH2 gene, of which exons 1-7 were deleted from patient No.3, exon 11 from No.25 and exons 2-6 from No.11. However, no genomic DNA fragment aberration of either MSH2 or MLH1 gene was uncovered from 20 sporadic CRC.

CONCLUSIONLarge DNA fragment aberrations of MSH2 gene was a frequent cause of Chinese HNPCC and CRC patients with family history, and the identification of those aberrations should be included in the regular genetic analysis for CRC/HNPCC patients.

Adaptor Proteins, Signal Transducing ; genetics ; Asian Continental Ancestry Group ; genetics ; Base Pair Mismatch ; China ; Colorectal Neoplasms, Hereditary Nonpolyposis ; ethnology ; genetics ; DNA Mutational Analysis ; Humans ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; Mutation ; Nuclear Proteins ; genetics

OBJECTIVESTo determine the germ-line mutations of hMSH2 and hMLH1 genes in Chinese hereditary nonpolyposis colorectal cancer (HNPCC) families' probands or in patients fulfilling different clinical criteria or guidelines; to clarify the nature and distribution of the mutations; to evaluate the sensitivity of different clinical criteria in mutation prediction.

METHODSThe entire coding regions (35 exons including exon-intron boundaries) of hMSH2 and hMLH1 genes were directly sequenced in 24 Amsterdam criteria (AC) probands, 15 Japanese criteria (JC) probands (except AC kindreds) and 19 Bethesda guidelines (BG) patients (except two former groups). All available affected and unaffected members from families of those with mutations were screened for mutation.

RESULTSIn 16 unrelated families selected by the different clinical criteria, 17 germ-line mutations were found with 11 (64.7%) of hMLH1 and 6 (35.3%) of hMSH2. Two mutations were identified in one of the families. Among the 17 germ-line mutations, 12 had not been reported previously. A diversified mutation spectrum was found, but 6 hMLH1 mutations were found to be concentrated in the region encompassing exon 14, 15 and 16. There was a wide spectrum of mutation type including frame shift, nonsense, splice site mutation, in frame insertion or deletion and missense mutations. The mutation detection rate of hMSH2 and hMLH1 in the AC group was significantly higher than that in the JC group (12/24 vs. 3/15). On the other hand, a low mutation rate (1/19) was detected in 19 BG patients. The mutation cosegregated with disease. Besides, three different genotypes in tumors from probands of mutation-positive families were found.

CONCLUSIONShMSH2 and hMLH1 mutations in Chinese HNPCC families show a wide spectrum. It seems that hMLH1 gene is involved more frequently than hMSH2 gene in Chinese HNPCC families. Different clinical criteria predict mutations with different sensitivities. The Amsterdam Criteria are most sensitive, while Japanese Criteria are highly practical and the Bethesda Guidelines are also practical to some extent. Gene mutations cosegregate with the disease phenotype. Carriers with no symptom in HNPCC families are most vulnerable groups, follow-ups are required for this group to get early diagnosis and to prevent the development of CRCs.

Adaptor Proteins, Signal Transducing ; Carrier Proteins ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; DNA-Binding Proteins ; Germ-Line Mutation ; Humans ; Microsatellite Repeats ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; Neoplasm Proteins ; genetics ; Nuclear Proteins ; Pedigree ; Proto-Oncogene Proteins ; genetics

OBJECTIVETo identify the MLH1 and MSH2 gene mutation in two hereditary nonpolyposis colorectal cancer (HNPCC) families.

METHODSPolymerase chain reaction and DNA sequencing were used to screen for MLH1 and MSH2 gene mutation, and PCR-restriction fragment length polymorphism and DNA sequencing were performed to confirm the mutation.

RESULTSBy DNA sequencing, a novel mutation of c.243_244insA located at the exon 3 of MLH1 gene was detected in family A, while c.1215_1218dupCCGA mutation located at the exon 7 of MSH2 gene was detected in family B. These two mutations can cause the formation of premature proteins.

CONCLUSIONThe novel mutations c.243_244insA in MLH1 gene and c.1215_1218dupCCGA in MSH2 gene were the disease-causing mutations in the two HNPCC families.

Adaptor Proteins, Signal Transducing ; genetics ; Asian Continental Ancestry Group ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; Female ; Humans ; Male ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; Mutation ; Nuclear Proteins ; genetics ; Pedigree ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length