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

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 construct a hMSH2/hMSH6 protein interaction system, and to use it for evaluating missense mutations detected in hMSH2 gene.

METHODSRecombinant plasmids pGADT7-hMSH2, pGBKT7-hMSH6 and 7 recombinant pGBKT7 plasmids with different hMSH6 domains were constructed through genetic engineering. Subsequently, site-directed mutagenesis was used to construct 10 mutant pGADT7-hMSH2 plasmids, which were transformed into yeast AH109. The growth of transformants was observed on a histidine-deficient culture.

RESULTSBoth hMSH6 MutSII-V and MutSIII-V could interact with hMSH2 in yeast AH109. Yeast two-hybrid transformants pGADT7-hMSH2/pGBKT7-hMSH6 MutSII-V were used to construct a hMSH2/hMSH6 protein interaction system. Compared with wild-type hMSH2, yeast two-hybrid transformants c.505A>G, c.1168C>T, c.1255C>A, c.1261C>A could grow normally, c.1223A>G, c.1886A>G, c.2108C>A and c.2516A>G grew slowly, c.518T>G and c.1664 delA could not grow in a histidine-deficient medium in yeast AH109.

CONCLUSIONA hMSH2/hMSH6 protein interaction system has been constructed with yeast two-hybrid system, which has been used for functional evaluation of hMSH2 gene missense mutations. c.518T>G is a pathological mutation. c.1223A>G, c.1886A>G, c.2108C>A, c.2516A>G may in part affect the hMSH2 function. And c.505A>G, c.1168C>T, c.1255C>A, c.1261C>A were innocuous variants.

Amino Acid Motifs ; Base Sequence ; DNA-Binding Proteins ; chemistry ; genetics ; metabolism ; Humans ; Molecular Sequence Data ; MutS Homolog 2 Protein ; chemistry ; genetics ; metabolism ; Mutation, Missense ; Protein Binding ; Saccharomyces cerevisiae ; genetics ; metabolism ; Two-Hybrid System Techniques

OBJECTIVE: To study the expression and significance of hMSH2 protein in laryngeal squamous cell carcinoma. METHOD: The expression of hMSH2 protein were detected by immunohistochemistry SP method in 51 cases of laryngeal squamous cell carcinoma, the control group included 30 cases of atypical hyperplasia tissue of vocal fold and 16 cases of normal laryngeal tissue. RESULT: The expression rates of hMSH2 in laryngeal squamous cell carcinoma, atypical hyperplasia tissue of vocal fold and normal laryngeal tissue were 58.8%, 73.3%, 87.5% respectively. There was significant difference among them (P < 0. 05). The expression of hMSH2 in laryngeal carcinoma was not associated with location and T stage (P > 0.05), but the expression was related with metastasis of lymph node and differentiation level (P < 0.05). CONCLUSION The deletion of hMSH2 maybe participate the early occurrence of laryngeal carcinoma; hMSH2 protein maybe delay and suppress oncogenesis and development of laryngeal carcinoma.
Carcinoma, Squamous Cell ; metabolism ; pathology ; Case-Control Studies ; Head and Neck Neoplasms ; metabolism ; pathology ; Humans ; Hyperplasia ; Immunohistochemistry ; Laryngeal Neoplasms ; metabolism ; pathology ; MutS Homolog 2 Protein ; metabolism ; Squamous Cell Carcinoma of Head and Neck

OBJECTIVETo explore the expression and sequence of human MutS homologue 2 (hMSH2) during different stages of human bronchial epithelial (16HBE) cells induced by cadmium chloride (CdCl2).

METHODSReverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical staining (SP method) were used to measure the hMSH2 mRNA and protein expression in 16HBE cells and its different passage cells treated by CdCl2 (the 5th, 15th, 35th passage, and neoplasm cells from nude mice's tumor tissue). hMSH2 exon 6, hMSH2 exon 7, hMSH2 exon 8, hMSH2 exon 9, hMSH2 exon 12 of the 16HBE cells and neoplasm cells from nude mice's tumor tissue were amplified by polymerase chain reactions (PCR). The amplified DNA strips were purified. Then the exons were detected by DNA analysis.

RESULTSDuring the passages of 16HBE cells treated with CdCl2, the expression of hMSH2 gene were decreased gradually. The hMSH2 gene mRNA and protein expression levels of the CdCl2 transformed 35th 16HBE cells and tumorigenic cells of nude mice significant decreased compared with non-transformed 16HBE cells (P < 0.01). In the tumorigenic cells of nude mice induced by CdCl2, there were thymine (T) deletion in 1st, 2nd and 7th site of hMSH2 exon 8, there were adenine (A) deletion in 20th and 182th site of hMSH2 exon 9, there were adenine (A) insertion in 241st site of hMSH2 exon 12. All the mutations were frame shift mutation.

CONCLUSIONThe expression decreased and the mutation of hMSH2 gene may be the possible carcinogenic mechanism for CdCl2.

Animals ; Bronchi ; cytology ; Cadmium Chloride ; toxicity ; Cell Line ; Cell Transformation, Neoplastic ; chemically induced ; genetics ; metabolism ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Humans ; Mice ; Mice, Nude ; MutS Homolog 2 Protein ; genetics ; metabolism ; Mutation ; RNA, Messenger ; genetics

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 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

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

OBJECTIVETo study the value of screening hereditary nonpolyposis colorectal cancer (HNPCC) kindreds by detecting the expressions of hMLH1/hMSH2 with tissue microarray.

METHODSA tissue microarray with 22 colorectal cancers from HNPCC families and 15 sporadic colorectal cancers was established, and the expressions of hMLH1/hMSH2 were detected by immunohistochemistry (IHC).

RESULTSThe expressions of hMLH1 or hMSH2 were negative in 15 of 22 HNPCC and 1 of 15 sporadic colorectal cancers in routine IHC. The expressions of hMLH1 or hMSH2 were negative in 17 of 22 HNPCC and 2 of 15 sporadic colorectal cancers in tissue microarray. The examination of hMSH2 expression yielded same results between routine IHC and tissue microarray. There were no difference on the hMLH1 expressions between routine IHC and tissue microarray.

CONCLUSIONTissue microarray is a high-throughput way to detect the expressions of hMLH1/hMSH2 and is applicable to screen HNPCC kindreds.

Adaptor Proteins, Signal Transducing ; metabolism ; Adult ; Aged ; Colorectal Neoplasms, Hereditary Nonpolyposis ; diagnosis ; genetics ; metabolism ; DNA Methylation ; Female ; Gene Frequency ; Genetic Testing ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Nuclear Proteins ; metabolism ; Pedigree ; Protein Array Analysis ; methods