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 analyze the expression of mismatch repair (MMR) protein and the EB virus infection in gastric adenocarcinoma, and to examine the association of MMR expression and EB virus infection with clinicopathological parameters. Methods: A case-control study was performed. Clinicopathological data of patients who was pathologically diagnosed as gastric adenocarcinoma, received radical gastrectomy and had complete clinicopathological data from August 2017 to April 2020 in Tianjin Medical University Cancer Institute and Hospital were retrospectively collected and analyzed. The immunohistochemistry (IHC) of MMR proteins and in situ hybridization (ISH) of Epstein-Barr virus encoded RNA (EBER) were reviewed. The associations of MMR and EBER results with clinicopathological parameters were analyzed. The main observations of the study were MMR and EBER expression, and association of MMR and EBER results with clinicopathological parameters. Results: Eight hundred and eighty-six patients were enrolled, including 98 patients who received preoperative neoadjuvant chemoradiotherapy. Of 886 patients, 613 (69.2%) were males and the median age was 60 (22-83) years; 831 (93.8%) were mismatch repair proficiency (pMMR), and 55 (6.2%) were mismatch repair deficiency (dMMR). In dMMR group, 47 cases (85.5%) had the deficiency of both MLH1 and PMS2, 1 case (1.8%) had the deficiency of both MSH2 and MSH6, 4 cases (7.3%) had the deficiency only in PMS2, 2 cases (3.6%) had the deficiency only in MSH6, and 1 case (1.8%) had the deficiency only in MSH2. The deficiency rates of PMS2, MLH1, MSH6 and MSH2 were 5.8% (51/886), 5.3% (47/886), 0.3% (3/886) and 0.2% (2/886), respectively. Among the 871 cases with EBER results, 4.9% (43/871) were positive EBER. Univariate analysis showed that dMMR was more frequently detected in female patients (χ(2)=10.962, P=0.001), cancer locating in the antrum (χ(2)=9.336,P=0.020), Lauren intestinal type (χ(2)=9.718, P=0.018), stage T3 (χ(2)=25.866, P<0.001) and TNM stage II (χ(2)=15.470, P=0.002). The ratio of dMMR was not significantly associated with age, tumor differentiation, histological type, lymph node metastasis, distant metastasis or Her-2 immunohistochemical score (all P>0.05). Compared with negative EBER, positive EBER was more frequent in male patients (χ(2)=9.701, P=0.002), cancer locating in gastric fundus and corpus (χ(2)=17.964, P<0.001), gastric cancer with lymphoid stroma (χ(2)=744.073, P<0.001) and poorly differentiated cancer (χ(2)=13.739, P=0.010). Positive EBER was not significantly associated with age, depth of invasion, lymph node metastasis, distant metastasis, TNM stage or Her-2 immunohistochemical score (all P>0.05). In addition, all dMMR cases were EBER negative, and all cases of positive EBER were pMMR. Conclusions: The positive EB virus status is mutually exclusive with dMMR, indicating that different molecular subtypes of gastric adenocarcinoma are involved in different molecular pathways in tumorigenesis and progression. The overlapping of dMMR or positive EBER status and positive Her-2 expression is found in some cases of gastric adenocarcinoma. Patients with gastric adenocarcinoma after radical surgery should be tested for MMR status if they are female, the tumor locates in gastric antrum, the TNM staging is stage II or T3, or if the Lauren classification is intestinal type. And if patients are male, the tumor locates in the gastric fundus and corpus, the cancer is lymphoid stroma, or poor differentiated, the expression of EBER should be detected. Results of our study may provide evidence for further decision-making of clinical treatment.
Adenocarcinoma ; Case-Control Studies ; DNA Mismatch Repair ; Epstein-Barr Virus Infections ; Female ; Herpesvirus 4, Human ; Humans ; Male ; Middle Aged ; Mismatch Repair Endonuclease PMS2/metabolism* ; MutL Protein Homolog 1/genetics* ; MutS Homolog 2 Protein/metabolism* ; Retrospective Studies ; Stomach Neoplasms

OBJECTIVETo investigate the expression of cyclooxygenase-2 (COX-2), human mut-l homologue 1 (hMLH1) and human mut-s homologue 2 (hMSH2) proteins in human paired gastric carcinoma (GC) and adjacent normal mucosa, and analyze their relationship with microsatellite instability (MSI).

METHODSThe protein expressions were examined by western blotting. Five MSI loci were assessed by PCR.

RESULTSIn 30 surgically excised GC tissues, the overexpression rate of COX-2, the low expression rate of hMLH1 and hMSH2 were 66.7%, 40% and 33.3%, respectively. Significant differences were found when compared with those of adjacent normal mucosa (P < 0.05). MSI was detected in 13 GC. The number of MSI-H (MSI-High, > or = 2 loci), MSI-L (MSI-Low, only one locus), and MSS (microsatellite stable) were 9, 4 and 17, respectively. The number of low expression rates of COX-2, hMLH1 and hMSH2 in MSI-H were 6, 8 and 5, respectively. There were significant differences compared to that of MSS (P < 0.05).

CONCLUSIONThe results suggest that microsatellite instability pathway is probably involved in the carcinogenesis of gastric carcinoma, which is frequently accompanied by low expression of hMLH1 and hMSH2, and may be also by low expression of COX-2.

Adaptor Proteins, Signal Transducing ; biosynthesis ; genetics ; Cyclooxygenase 2 ; biosynthesis ; genetics ; Humans ; Microsatellite Repeats ; genetics ; MutL Protein Homolog 1 ; MutL Proteins ; Neoplasm Proteins ; biosynthesis ; genetics ; Nuclear Proteins ; biosynthesis ; genetics ; Stomach Neoplasms ; genetics ; metabolism

Objective: To investigate the molecular classification and clinicopathological features of endometrial carcinoma(EC). Methods: One hundred cases of EC diagnosed in the Department of Pathology, Tianjin Central Hospital of Gynecology and Obstetrics from November 2020 to November 2021 were selected. Sanger sequencing and immunohistochemical staining were used for molecular classification according to the 5th WHO classification. The clinicopathological characteristics of each molecular subtype was analyzed. Results: The 100 EC patients had a mean age of 53 years (range 26 to 72 years). There were 10 cases of POLE mutation (POLE mut), including two cases (2/10) of "binary-classifier" EC, two cases (2/10) of FIGO Grade 3 endometrioid endometrial carcinoma (G3-EEC), and three cases (3/10) of other high-grade subtypes. There were 38 cases of mismatch repair deficiency (dMMR), including one case (1/38, 2.6%) of "binary-classifier" EC and 36 cases (36/38, 94.7%) were EEC. Twenty-one cases (21/38, 55.3%) showed simultaneous loss of expression of MLH1 and PMS2, and 20 cases (20/21, 95.2%) were positive for MLH1 methylation, indicating that they were sporadic EC. Six patients (6/38, 15.8%) were tested for germline detection of Lynch syndrome (LS) related genes, and one patient was LS-related EC. There were 44 cases of non-specific molecular profile (NSMP), including 34 cases (34/44, 77.3%) of G1-2 EEC and seven cases (7/44, 15.9%) of G3-EEC. There were eight cases of p53 abnormality (p53 abn), including four cases (4/8) of G3-EEC, two cases (2/8) of other high-grade subtypes, and one patient had hereditary breast cancer and ovarian cancer syndrome. Conclusions: Correct interpretation of POLE mutation, MMR and p53 immunohistochemistry is the key of molecular classification. The interpretation must strictly follow standard diagnostic procedures and specifications to ensure the accuracy of molecular classification.
Adult ; Aged ; Carcinoma, Endometrioid/genetics* ; Colorectal Neoplasms, Hereditary Nonpolyposis/pathology* ; DNA Mismatch Repair ; Endometrial Neoplasms/pathology* ; Female ; Humans ; Middle Aged ; Mismatch Repair Endonuclease PMS2/metabolism* ; MutL Protein Homolog 1/metabolism* ; Tumor Suppressor Protein p53/metabolism*

OBJECTIVETo explore whether the abnormality of hMLH1 gene may be an early event of carcinogenesis in rectal carcinoma, and to evaluate the diagnostic value in differentiation between intraepithelial neoplasm and early stage of colorectal carcinoma.

METHODSThe expression of hMLH1 protein in 28 cases with early invasive rectal carcinoma(EIRC), 36 cases with rectal intraepithelial neoplasm(RIEN), and 30 cases with normal rectal mucosa(NRM) which were collected through surgical operations were detected by PV-9000 immunohistochemical method.

RESULTSThe positive expression rates of hMLH1 protein were 100%(30/30), 77.8%(28/36), and 39.3%(11/28) in NRM, RIEN, and EIRC respectively. The difference was statistically significant between RIEN and EIRC(P=0.002), and the difference was also statistically significant between RIEN and NRM(P=0.006). The positive expression of hMLH1 was not related to age, gender, tumor maximum diameter, dysplasia, tumor types, and distance from the anal verge in RIEV group(P>0.05). In EIRC group, hMLH1 was associated with tumor differentiation(P<0.05).

CONCLUSIONhMLH1 gene deletion may be an early event during carcinogenesis of rectal carcinoma, which may be useful in differentiation of intraepithelial neoplasm from early rectal carcinoma.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adult ; Aged ; Aged, 80 and over ; Carcinoma in Situ ; diagnosis ; metabolism ; Early Detection of Cancer ; Female ; Humans ; Male ; Middle Aged ; MutL Protein Homolog 1 ; Nuclear Proteins ; genetics ; metabolism ; Rectal Neoplasms ; diagnosis ; metabolism

OBJECTIVE: To investigate the role of Human MutL homologue 1 (hMLH1) gene promoter methylation in the occurrence and development of osteoarthritis (OA). METHODS: General DNA was dealt with sodium bisulfite. The methylation of hMLH1 promoter was detected by methylation-specific PCR (MSP). hMLH1 protein expression in joint cartilage was detected by immunohistochemical method. RESULTS: The positive percent of hMLH1 promoter methylation in OA patients was higher than that in healthy persons (χ(2)=30.634, P<0.001); the positive percent of hMLH1 protein in OA patients was significantly lower than that in healthy persons (χ(2)=37.724, P<0.001); prmoter methylation and protein expression level of hMLH1 gene showed negative correlation (rs=-0.554, P<0.001). CONCLUSION hMLH1 promoter is hypermethlated in joint cartilage cells of OA patients. Hypermethylation may affect the protein expression of hMLH1, which might play a role in the occurrence and development of OA.
Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adolescent ; Adult ; Cartilage, Articular ; metabolism ; Child ; DNA Methylation ; Female ; Humans ; Male ; MutL Protein Homolog 1 ; Nuclear Proteins ; genetics ; metabolism ; Osteoarthritis ; genetics ; metabolism ; Promoter Regions, Genetic ; genetics ; Young Adult

OBJECTIVETo evaluate the application of mismatch repair (MMR) genes proteins expression to screen for Lynch syndrome in colorectal cancer patients.

METHODSOne hundred consecutive colorectal cancers cases collected from 2012 to 2013 were tested immunohistochemically for the protein expression of MLH1, MSH2, MSH6 and PMS2, and also by the ARMS method for the mutation status of BRAF genes in those cases lacking protein expression for MLH1.

RESULTSThe result of MMR immunocytochemistry showed that nine of 100 cases lacked MMR protein expression, including three cases each that were MLH1-/PMS2- and MSH2-/MSH6- respectively, two cases were MLH6- and one case was PMS2-; overall, the majority of these cases lacked protein expression of MLH1 and MSH2. The BRAF genes mutation test showed one case of mutation, indicating that the patient might have MLH1 gene methylation as a result of the mutation of BRAF genes, and that was a sporadic case. The age of onset for patients lacking MMR protein expression was lower than patients with sporadic colorectal cancer (P = 0.011). Colorectal cancers associated with the lack of MMR protein expression mostly occurred in the right colon (P = 0.001), and histomorphologically were often accompanied by mucinous adenocarcinoma (P = 0.010) and tumor lymphocytic infiltration.

CONCLUSIONImmunohistochemical staining for MMR proteins in patients with colorectal cancer, accompanied by testing for BRAF genes mutation, may be an effective approach to screen for Lynch syndrome.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Colorectal Neoplasms, Hereditary Nonpolyposis ; diagnosis ; genetics ; DNA Mismatch Repair ; Humans ; Immunohistochemistry ; MutL Protein Homolog 1 ; Mutation ; Nuclear Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins B-raf ; genetics ; metabolism

OBJECTIVETo investigate the expression of DNA mismatch repair (MMR) genes (MLH1, MSH2, MSH6 and PMS2) in endometrial adenocarcinoma (EC) of patients under 50 years and to explore the relationship between MMR expression and clinicopathological features including body mass index (BMI), histological grade and pathological stage of EC.

METHODSMMR gene expression was investigated by immunohistochemical S-P method in endometrial adenocarcinomas of patients under age of 50. The control groups included complexity atypical hyperplasia endometrium (CAHE), simple hyperplasia endometrium (SHE), normal endometrium (NE) of patients under age of 50 and EC of patients older than 65 years.

RESULTSTwenty seven of 40 EC (67.5%) lost at least one MMR protein expression. Loss of at least one MMR protein expression was seen in 5/15 cases of CAHE, 1/13 SHE and 1/11 NE, respectively (P < 0.01). The rates of loss of expression of MLH1, MSH2, MSH and PMS2 proteins in EC were 52.5%, 12.5%, 35.0%, and 30.0%, respectively. The difference between MLH1 and MSH6 expression among the four groups were significant (P < 0.05), but the expression of MSH2 showed no significant difference among the groups (P = 0.295). The expression of MMR protein had no relationship with histological grade and pathological stage, although loss of MSH6 was more frequently seen in patients of higher BMI.

CONCLUSIONSAbnormal expression of MMR proteins is correlated with the development of EC from complex atypical hyperplasia. With the exception of the correlation of MSH6 expression with higher BMI, the expression of MMR proteins in EC has no significant relationship with histological grade and pathological stage.

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; genetics ; metabolism ; pathology ; Adenosine Triphosphatases ; metabolism ; Adult ; Body Mass Index ; DNA Mismatch Repair ; DNA Repair Enzymes ; metabolism ; DNA-Binding Proteins ; metabolism ; Endometrial Neoplasms ; genetics ; metabolism ; pathology ; Female ; Humans ; Immunohistochemistry ; Middle Aged ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasm Grading ; Neoplasm Staging ; Nuclear Proteins ; metabolism

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adenosine Triphosphatases ; genetics ; metabolism ; DNA Mismatch Repair ; DNA Repair Enzymes ; genetics ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Endometrial Neoplasms ; etiology ; genetics ; metabolism ; pathology ; Female ; Genetic Predisposition to Disease ; Humans ; Lynch Syndrome II ; complications ; genetics ; metabolism ; pathology ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; metabolism ; Mutation ; Nuclear Proteins ; genetics ; metabolism

OBJECTIVETo investigate the expression and clinical significance of mismatch repair genes hMLH1 and hMSH2 in sporadic colorectal carcinoma tissues.

METHODSThe expression of hMLH1 and hMSH2 proteins was detected in the 63 sporadic colorectal carcinoma samples by immunohistochemical staining, including tumor tissue, adjacent tissue at 3 cm from the carcinoma, and normal tissue at 10 cm away from the tumor.

RESULTSThe positive rate of hMLH1 protein expression in the 63 normal colorectal tissues, adjacent tissues and sporadic colorectal carcinoma tissues was 95.2%, 85.7% and 81.0%, respectively. The positive rate of hMLH1 protein expression was significantly lower in the tumor than in normal colorectal tissues (P < 0.05). The positive rate of hMSH2 protein in the 63 normal colorectal tissues, adjacent tissues and sporadic colorectal carcinoma tissues were 76.2%, 66.7% and 52.4%, respectively. The positive rate of hMSH2 protein expression was significantly lower in the tumor than in normal colorectal tissues (P < 0.01). The positive rate of hMLH1 protein expression was significantly higher in the tumor tissue of patients aged younger than 60 years (100%) than that in patients ≥ 60 years (75.0%, P < 0.05). The positive rate of hMLH1 protein expression in the tumor tissue accompanied by lymphatic metastasis was 50.0%, significantly lower than that (93.3%) in tumors without lymphatic metastasis (P < 0.05). The positive rate of hMSH2 protein expression in the tumor tissue of patients aged younger than 60 years was 80.0%, significantly higher than that (43.8%) in the cases ≥ 60 years (P < 0.05). The positive rate of hMSH2 protein expression in the tumor tissues with invasion reaching to the intestinal serosa (61.5%) was significantly higher than that (37.5%) in the tumors invading to submucosa or muscular layer (P < 0.05). There was a positive correlation between the expressions of hMLH1 and hMSH2 proteins in the sporadic colorectal carcinomas.

CONCLUSIONThere is a certain loss of expression of hMLH1 and hMSH2 proteins in sporadic colorectal carcinoma, and is correlated with the age of patients, lymphatic metastasis and different depth of cancer invasion. HMLH1 and hMSH2 may be used as a useful laboratory marker in clinical judgement of occurrence and development of sporadic colorectal carcinoma.

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; metabolism ; pathology ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; metabolism ; Colonic Neoplasms ; metabolism ; pathology ; Female ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasm Invasiveness ; Nuclear Proteins ; metabolism ; Rectal Neoplasms ; metabolism ; pathology