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Objective:To study the clinical characteristics of Lynch syndrome-associated endometrial cancer in elderly patients and the relationship of the disease with MSH2 gene mutations in patients' families.Methods:Clinical data of 473 elderly patients with endometrial cancer admitted to our hospital between January 2016 and January 2021 were retrospectively analyzed.MSH2 gene mutations were detected and verified by DNA sequence analysis, real-time quantitative PCR and reverse transcription PCR.Patients were divided into a Lynch syndrome group and a non-Lynch syndrome group, and the clinicopathological features of the two groups were compared.Results:Of 473 endometrial carcinoma patients, 46(9.7%)had embryogenic mutations of the MMR gene and were diagnosed with Lynch syndrome, with 18, 6, 24 and 10 patients carrying MLH1, PMS2, MSH2 and MSH6 mutations, respectively.There were 3 mutations in the MSH2 gene, including exon 7 1380C>A, exon 12 2011A>G and exon 13 2756A→AC.The proportions of patients with G3 grade endometrioid adenocarcinoma, lower uterine segment involvement and a history of Lynch syndrome-associated malignant tumors in the Lynch syndrome group were significantly higher than those in the non-Lynch syndrome group( χ2=8.935, 8.303, 9.770, all P<0.05). Conclusions:Poorly differentiated endometrioid adenocarcinoma, predisposition to lower uterine segment involvement and familial inheritance are the main clinical manifestations of Lynch syndrome-associated endometrial carcinoma in elderly patients, with the most common mutations seen in the MSH2 gene.
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O câncer colorretal (CCR) é o terceiro tipo de câncer mais comum no mundo e a segunda causa de morte por câncer. Dados atuais apontam que o câncer de reto (CaRe) contribui para a maior incidência de CCR observada em pacientes jovens e é responsável por um aumento destes tumores em cerca de 75% nos últimos 40 anos. As variantes germinativas são reportadas em 14 a 16% dos indivíduos jovens com CCR, independente de história familiar de câncer. Ainda assim, a causa do desenvolvimento de CCR na maioria dos casos de indivíduos jovens ou famílias com múltiplos indivíduos afetados permanece desconhecida. Neste estudo, foram investigadas variantes germinativas em 76 pacientes com CaRe incluindo 29 classificados pelos critérios de Amsterdam I/II para a Síndrome de Lynch (Grupo 1) e 47 pacientes com idade igual ou inferior 40 anos (Grupo 2). O objetivo principal foi identificar variantes em 93 genes relacionados ao câncer que possam contribuir para o risco de desenvolvimento da doença usando sequenciamento de alto desempenho. Quinze variantes foram selecionadas e avaliadas em membros de oito famílias. Foram identificadas 153 variantes envolvendo 65 genes. Pacientes com câncer de reto apresentaram alta frequência de variantes germinativas em ATM (19%), APC (10%) e BRCA2 (9%). Variantes patogênicas ou likely-patogênicas foram identificadas em genes de alta (MSH2, MSH6, MLH1, MUTYH e BRCA2), moderada (ATM) e baixa (MTHFR e NOTCH1) penetrância, em 18% (14/76) dos pacientes, concordante com dados da literatura. Variantes características da Síndrome de Lynch foram identificadas em seis pacientes (6/76) e variantes associadas à polipose no gene MUTYH, em dois pacientes (2/76). Variantes patogênicas ou likely-patogênicas foram identificadas em 17% (8/47) dos pacientes jovens, especialmente em MUTYH (3/47), MTHFR (2/47), ATM, MSH6 e MLH1 (1/47 cada). Dentre estes, dois de 14 pacientes não reportaram câncer na família e seis tiveram pelo menos um caso de câncer na família, mas não preencheram os critérios clínicos para síndrome de predisposição hereditária ao câncer. Este estudo revelou 25 variantes novas (não identificadas em bancos de dados públicos ou reportadas em literatura). Em adição, foram observadas variantes germinativas em diferentes genes das vias MMR e de recombinação homóloga, incluindo ATM, BRCA2 e POLD1. Foram identificadas 15 variantes candidatas e ou associadas ao fenótipo nos genes ATM, APC, MSH2, MTHFR, CDKN2A, MUTYH e POLD1. Essas variantes foram avaliadas em 20 indivíduos de 8 famílias, sendo confirmadas nos probandos e identificadas em mais de um membro das famílias investigadas. A identificação de genes associados à predisposição ao CaRe tem potencial importância para o delineamento de estratégias mais eficientes de diagnóstico e aconselhamento genético em famílias com um alto risco de desenvolver este tumor (AU)
Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. Recent studies suggest that rectal cancer (ReCa) contributes to the higher CRC incidence observed in young patients, and it is responsible for 75% of the increased incidence in colorectal tumors over the last 40 years. Germline variants have been reported in 14-16% of patients with early-onset CRC, regardless of family history of cancer. Nonetheless, the causes of CRC onset in most young patients or families with multiple affected cases remain unknown. We investigated germline variants in 76 ReCa patients, including 29 cases classified by the Amsterdam I/II criteria for Lynch Syndrome (Group 1) and 47 early-onset ReCa patients (≤40 years old, Group 2). The main objective was to identify variants in 93 cancer-related genes that can contribute to increased risk of the disease development using next-generation sequencing. Fifteen candidate variants were evaluated in eight selected families. Next-generation sequencing revealed 153 variants involving 65 genes. ReCa patients showed high frequency of germline variants in ATM (19%), APC (10%) and BRCA2 (9%). Pathogenic or likely-pathogenic variants were observed in high (MSH2, MSH6, MLH1, MUTYH, and BRCA2), moderate (ATM) and low (MTHFR and NOTCH1) penetrance genes, in 18% (14/76) of the patients, consistent with the literature data. Variants associated with Lynch Syndrome were identified in six patients (6/76), and variants involved in MUTYH-associated polyposis in two patients (2/76). Pathogenic or likely-pathogenic variants were identified in 17% (8/47) of early-onset patients, especially in the MUTYH (3/47), MTHFR (2/47), ATM, MSH6, and MLH1 (1/47 each) genes. Among these, two of fourteen patients had no family history of cancer and six reported at least one case of cancer in the family, but none of them met clinical criteria for the hereditary cancer syndrome. This study revealed 25 new variants (not reported in public databases or previous studies). In addition, germline variants were observed in several genes involved in MMR and homologous recombination (HR) pathways, including ATM, BRCA2 and POLD1. Fifteen candidates and associated to the phenotype variants were identified in the ATM, APC, MSH2, MTHFR, CDKN2A, MUTYH, and POLD1 genes. These variants were evaluated in 20 individuals (8 families), being confirmed in the index cases and identified in more than one relative of the evaluated families. The identification of genes associated with ReCa predisposition is crucial for outlining more efficient diagnostic strategies and for improving genetic counseling for families with high risk to develop this tumor type (AU)
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Humans , Male , Female , Middle Aged , DNA , Colorectal Neoplasms/genetics , Heredity , Early Detection of Cancer , Pathology, Molecular , High-Throughput Nucleotide SequencingABSTRACT
Objective@#To investigate the associations between genetic variations in DNA mismatch repair genes and sensitivity as well as prognosis to preoperative chemoradiotherapy in patients with locally advanced rectal cancer.@*Methods@#Fourteen haplotype-tagging single nucleotide polymorphisms (htSNPs) of MLH1, MLH3 and MSH2 genes were genotyped by Sequenom MassARRAY method in 146 patients with locally advanced rectal cancer who received preoperative chemoradiotherapy. The associations between genotypes and response to capecitabine-based neoadjuvant chemoradiotherapy (nCRT) were measured by odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for sex, age, clinical stages and karnofsky performance score (KPS) by unconditional logistic regression model. The survival analyses were performed by the hazard ratios (HRs) and 95% CIs by Cox proportional regression model.@*Results@#Among 146 cases, 64 patients were nCRT responders with a response rate of 43.8%. MLH3 rs175057 C>T and MSH2 rs13019654 G>T loci were associated with the sensitivity to preoperative chemoradiotherapy. Compared with the rs175057 CC genotype, the adjusted OR for patients with CT and TT genotypes was 0.42 (95% CI: 0.19-0.91; P=0.029). Moreover, for rs13019654, the adjusted OR for patients with the GT or TT genotypes was 0.49 (95% CI: 0.24-0.98; P=0.047) than those with GG genotype. The remaining 12 SNPs, including rs1540354, rs4026175, rs1981929, rs2042649, rs2303428, rs3771273, rs4608577, rs4952887, rs6544991, rs6544997, rs10188090 and rs10191478, were not significantly associated with therapeutic response to preoperative chemoradiotherapy. Meanwhile, MLH3 rs175057 C>T locus was also associated with longer overall survival time in locally advanced rectal cancer (HR=0.44, 95% CI: 0.20-0.96, P=0.038), whereas MSH2 rs3771273 T>A, rs10188090 A>G and rs10191478 T>G loci were associated with shorter overall survival time (HR=1.74, 95% CI: 1.06-2.84, P=0.028; HR=1.64, 95% CI: 1.01-2.66, P=0.046; HR=1.71, 95% CI: 1.01-2.91, P=0.047, respectively). The remaining 10 SNPs, including rs1540354, rs4026175, rs1981929, rs2042649, rs2303428, rs4608577, rs4952887, rs6544991, rs6544997 and rs13019654, were not significantly associated with prognosis.@*Conclusions@#Genetic polymorphisms of MLH3 rs175057 and MSH2 rs13019654 loci can predict the nCRT response, while MLH3 rs175057 as well as MSH2 rs3771273, rs10188090 and rs10191478 may predict prognosis in patients with locally advanced rectal cancer who received preoperative chemoradiotherapy. Therefore, these SNPs could be used as potential genetic markers in the personalized therapy of rectal cancer.
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Objective: To investigate the expressions of mismatch repair gene MutL homolog 1 (MLH1) and MutS homolog 2 (MSH2) in stage II-III sporadic colorectal adenocarcinoma tissues and their clinical signifiance. Methods: The specimens and follow-up data of 490 patients with sporadic colorectal cancer were collected after surgery from January 2014 to April 2016 in Nanjing Hospital of Chinese Medicine. The expressions of MLH1 and MSH2 in colorectal cancer were detected by immunohistochemistry. The relationships of MLH1 and MSH2 expressions with the clinical characteristics and prognosis of patients with colorectal cancer were analyzed. Results: The deletion rate of MLH1/MSH2 expression in colorectal cancer tissues was 20.41% (100/490). The MLH1/MSH2 deletion was correlated with tumor differentiation, location, mucus and lymph node metastasis (all P < 0.05). MLH1/MSH2 deletion mainly occurred in the patients with poorly differentiation, right colon, mucus, and 1-3 lymph nodes metastasis. The disease-free survival (DFS) time of patients with MLH1/MSH2 deletion was longer than that of patients with MLH1/MSH2 normal expression (33.9 months vs 30.4 months, P < 0.001). The prognosis of patients with right colon tumor, poor differentiation, TNM stage III, metastatic lymph nodes more than four, mucus, positive margin and MLH1/MSH2 normal expression was poor (all P < 0.05). The tumor differentiation, tumor location, mucus, surgical margin and expression of MLH1/MSH2 were independent prognostic factors for the patients with stage II - III sporadic colorectal cancer. Conclusion: There is MLH1/MSH2 deletion in stage II - III sporadic colorectal cancer tissues, and it is an independent prognostic factor in patients with colorectal cancer.
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Objective To explore the lethal action and possible mechanism of RI-1, a RAD51 inhibitor, on MSH2 deficient colorectal cancer cells.Methods The expression of MSH2 protein level was assessed by Western blot, and the sensibility of human colorectal cancer cells to RI-1 (10, 20, 30, 40 and 50 μmol/L)was measured by MTT method.Lentivirus vectors MSH2-shRNA and Neg-shRNA (negative control) were constructed and transfected into HT29 cell.Apoptosis and DNA damage of cells treated with RI-1(40 μmol/L)were detected by flow cytometry and Single cell gel electrophoresis respectively.In addition, the formation of γ-H2AX foci was analyzed by immunofluorescence.Results Compared with control, MSH2-deficient HCT8 cells had obviously apoptosis(P<0.01);in HCT8 and HT29 Shmsh2 cells, tail DNA%, tail length, tail moment and olive tail moment were markedly increased(P<0.05),and the number of γ-H2AX focus were increased(P<0.01).Conclusions RAD51 inhibitor RI-1 selectively kills MSH2 deficient colorectal cancer cells by increasing DNA damage.
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Recently, certain endometrial carcinomas have been found to be associated with mismatch repair (MMR) protein defects/deficiency. A 39-year-old female presented with cough, decreased appetite and significant weight loss since 2 months. Earlier, she had undergone total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH-BSO) for endometrioid adenocarcinoma. Imaging disclosed an 8 cm-sized adrenal mass that was surgically excised. Histopathology of the adrenal tumor, endocervical tumor, and endometrial biopsy revealed Federation of Gynecology and Obstetrics (FIGO) Grade II to III endometrioid adenocarcinoma. By immunohistochemistry, tumor cells were positive for cytokeratin 7, epithelial membrane antigen, PAX8, MLH1 and PMS2 while negative for estrogen receptor (ER), progesterone receptor (PR), MSH2 and MSH6. She underwent adjuvant radiotherapy and chemotherapy. A 34-year-old lady presented with vaginal bleeding since 9 months. She underwent TAH-BSO, reported as FIGO Grade III endometrioid adenocarcinoma. By immunohistochemistry, tumor cells were negative for ER, PR, MLH1, and PMS2 while positive for MSH2 and MSH6. She underwent adjuvant radiotherapy and chemotherapy. However, she developed multiple nodal and pericardial metastases and succumbed to the disease within a year post-diagnosis. Certain high-grade endometrioid adenocarcinomas occurring in younger women are MMR protein deficient and display an aggressive clinical course. Adrenal metastasis in endometrial carcinomas is rare.
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OBJECTIVE: The hereditary nonpolyposis colorectal cancer is inherited syndrome characterized by the development of cancers in various organ system; these includes colorectum, endometrium, and less frequently, small bowel, stomach, urinary tract, ovaries, and brain. We aimed to investigate the clinicopathologic characteristics of hereditary nonpolyposis colorectal cancer patients who had both endometrial and colorectal cancers. METHODS: Between January 2004 and December 2013, 12 women diagnosed with endometrial and colorectal cancers in a single institution were included in this analysis. For these patients, clinical and molecular findings were analyzed retrospectively. RESULTS: All 12 women undertook microsatellite instability analysis, and 9 (75%) were confirmed of having microsatellite instability-high. Among 9 cases with immunohistochemical staining for MLH1 and MSH2, 6 were positive for the loss of mismatch repair protein. Mutational analyses for MLH1 and MSH2 were performed in 3 out of 12 patients; all of them showed germline mutation. CONCLUSION: This study suggests that there is a genetic background in patients with double primary malignancies in their endometrium and colorectum when analyzed with microsatellite instability studies, immunohistochemistry staining, and mutation studies. This finding supports the necessity of re-defining the high-risk groups in endometrial cancers clinically. This will also help diagnose malignancies in such patients in early stages, as well as counsel other family members.
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Female , Humans , Brain , Colorectal Neoplasms , Colorectal Neoplasms, Hereditary Nonpolyposis , DNA Mismatch Repair , Endometrial Neoplasms , Endometrium , Germ-Line Mutation , Immunohistochemistry , Microsatellite Instability , Microsatellite Repeats , Ovary , Retrospective Studies , Stomach , Urinary TractABSTRACT
Objective To observe the effects of MSH2 gene re expression on estrogen-induced apoptosis of colon cancer cells LOVO,and to explore its mechanisms.Methods According to different plasmid and whether with estradiol intervention,colon cancer LOVO cells were divided into empty plasmid with ethanol group,empty plasmid with estradiol group,MSH2 with ethanol group,MSH2 with estradiol group,estrogen receptor (ER) β with ethanol group,ERβ with estradiol group,ERβ with MSH2 and ethanol group and ERβ with MSH2 and estradiol group,and received corresponding treatment.The expression of MSH2,ERβ protein and apoptosis related caspase 3 protein were detected by Western blotting.Cell viability was measured by cell counting kit-8.Cell DNA fragments of each group were isolated with apoptosis DNA fragments isolation kit.And the DNA ladder was observed.The rate of apoptosis was detected by flow cytometer.Single factor variance analysis was performed for comparison among multiple groups,and t test was used for comparison between the two groups.Results After transfection,the expression of the MSH2 and ERβ at protein level in LOVO cells significantly increased and neither of their expression was effected by estradiol.The expression levels of caspase 3 cleavaged active fragments of ERβ with estradiol group and ERβ with MSH2 and ethanol group were higher than other groups,and there was no significant difference between these two groups.The LOVO cell viability of empty plasmid with ethanol group,empty plasmid with estradiol group,MSH2 with ethanol group,MSH2 with estradiol group,ERβ with ethanol group,ERβ with estradiol group,ERβ with MSH2 and ethanol group and ERβ with MSH2 and estradiol group was 1.72 ±0.25,1.74 ± 0.31,1.77 ± 0.35,1.74±0.33,1.70±0.34,1.02±0.48,1.71±0.31 and 1.07±0.18,respectively,and the differences between the groups were statistically significant (F=3.791,P＜0.05).Among them,the LOVO cell viability of ERβ with estradiol group was lower than that of ERβ with ethanol group,accordingly,that of ERβ with MSH2 and estradiol group was lower than that of ERβ with MSH2 and ethanol group,that of ERβ with estradiol group was lower than that of empty plasmid with estradiol group,that of ERβ with MSH2 and estradiol group was lower than that of MSH2 with estradiol group,and the differences were statistically significant (t=3.158,3.075,3.648,3.253,all P＜0.05).DNA ladder formed from DNA fragments of apoptosis cells was seen in ERβ with estradiol group and ERβ with MSH2 and estradiol group.The apoptosis rate of empty plasmid with ethanol group,empty plasmid with estradiol group,MSH2 with ethanol group,MSH2 with estradiol group,ERβ with ethanol group,ERβ with estradiol group,ERβ with MSH2 and ethanol group and ERβ with MSH2 and estradiol group was 7.86±0.19,7.87±0.39,8.39±1.02,9.05±1.54,7.54±0.99,19.77±2.35,7.76±1.32 and 19.30±1.75,respectively,and the differences between groups were statistically significant (F=45.436,P＜0.05).Among them,the apoptosis rate of ERβ with ethanol group was lower than that of ERβ with estradiol group,that of ERβ with MSH2 and ethanol group was lower than that of ERβ with MSH2 and estradiol group,that of empty plasmid with estradiol group was lower than that of ERβ with estradiol group,that of ERβ with MSH2 and estradiol group was lower than that of MSH2 with estradiol group,and the differences were statistically significant (t =8.260,9.133,8.596,7.617,all P＜ 0.05).Conclusions Estrogen may promote colon cancer cell apoptosis through ERβ pathway.The process of apoptosis maybe related with caspase protein,MSH2 may not be involved in the regulation of this signal pathway.
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A Síndrome de Lynch (SL) ou Câncer Colorretal Hereditário Não -Poliposo (HNPCC) é uma doença autossômica dominante associada a mutaçõesna linhagem germinativa nos genes do Sistema Mismatch Repair (MMR)de reparo do DNA e é responsável por aproximadamente 5% de todos os casos de câncer colorretal (CCR). A maioria das mutações ocorre nos genes MSH2 (50%) e MLH1 (40%), e gera uma proteína truncada e não funcional. Mais de 513 alterações diferentes nos genes de reparo foram relatadas, sendo que 10% das encontradas no gene MSH2envolvem a substituição de um aminoácido. O sistema de reparo MMR corrige erros de pareamento base base, além de inserções e deleções que ocorrem durante a síntese do DNA, melhorando a fidelidade do mecanismo de replicação, além de estar envolvido nos processos de ecombinação, na geração da diversidade imune e na resposta celular a danos específicos a o DNA. A inativação mutacional dos genes MMR leva a um reparo insuficiente do DNA e ao desenvolvimento de tumores caracterizados pelos altos níveis MSI...
Lynch syndrome (SL) or Colorectal Cancer Hereditary nonpolyposis (HNPCC) is an autosomal dominant disease associated with germline mutations in the MMR genes of the DNA repair system and it is responsible for approximately 5% of all cases of colorectal cancer (CCR). Most of the mutations occur in the MSH2 (50%) and MLH1 genes (40%), and generates a truncated, nonfunctional protein. More than 513 different changes in repair genes have been reported, and 10% of those mutations can be found in the MSH2 gene causing substitution of one amino acid. The repair system MMR corrects mismatched nucleotides, insertions and deletions that occur during DNA synthesis, improving the fidelity of replication mechanism and it is also involved in the process of recombination in the generation of immune diversity and specific cellular response to DNA damage. Mutational inactivation of MMR genes leads to insufficient DNA repair and the development of tumors characterized by high levels of MSI. SL patients often develop colorectal cancer at an early age, and they also have an increased risk of developing extra colonic tumors. The main objective of this study was to identify sequence variants in the MSH2 gene in selected patients for Lynch syndrome according to the criteria of Amsterdam or modified Bethesda, assessing the sensitivity and specificity for the presence of the mutation... .
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Male , Female , Colorectal Neoplasms, Hereditary NonpolyposisABSTRACT
O câncer colorretal tem importância elevada frente a sua incidência e morbidade. Dentre os casos hereditários, o câncer colorretal hereditário sem polipose (HNPCC), ou Síndrome de Lynch, é responsável por cerca de 5% do total de casos. No HNPCC, a alteração genética herdada é a inativação de um dos alelos dos genes envolvidos em reparo do DNA, sendo os principais os genes hMLH1 e hMSH2. O objetivo deste trabalho foi investigar, em indivíduos com diagnóstico clínico de HNPCC, a presença de mutações nos genes MLH1 e MSH2, associar as variáveis clínicas com o gene mutado e investigar os familiares de portadores de HNPCC aos quais tivemos acesso, com relação a mutações germinativas. A investigação das mutações foi realizada por meio de sequenciamento direto dos éxons, região promotora e regiões de junção. Foram analisados 65 indivíduos divididos em três grupos, sendo (I) 46 pacientes portadores de câncer colorretal inclusos nos Critérios de Amsterdã, (II) dois familiares portadores de câncer colorretal e (III) 17 familiares sem câncer, todos da região metropolitana de Campinas, atendidos no Hospital de Clínicas da UNICAMP. Em 21 (45,65%) dos pacientes foram encontradas mutações deletérias. As mutações deletérias nos genes MLH1 e MSH2 estavam na proporção de 34,78% (16 pacientes) e 10,86% (5 pacientes), respectivamente. As mutações não deletérias nos genes MLH1 e MSH2 estavam na proporção de 65,22% dos pacientes (30 alterações) e 50% dos pacientes (23 alterações), respectivamente...
Colorectal cancer has high importance because of its incidence and morbidity. Among the hereditary cases, the hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome, accounts for about 5% of cases. In HNPCC, the genetic alteration inherited is the inactivation of one of the alleles of genes involved in the DNA repair, being hMSH2 and hMLH1 the main genes. The objective of this study is to investigate the presence of mutations in MLH1 and MSH2 in patients with clinical diagnosis of HNPCC, correlate clinical variables with the mutated gene, and investigate the relatives of patients with HNPCC who we had access to, in relation to germline mutations. Investigation of the mutations was performed by éxons direct sequencing, the promoter and junction regions. Sixty-five individuals, divided into three groups, were studied: (I) 46 patients with colorectal cancer included in the Amsterdam Criteria, (II) two family members of colorectal cancer patients and (III) 17 relatives without cancer, all of them treated at Hospital das Clínicas at UNICAMP and living in the Campinas metropolitan area. Deleterious mutations were found in 21 patients (45.65%). The ratio of deleterious mutations in MLH1 and MSH2 was 34.78% (16 patients) and 10.86% (5 patients) respectively. The ratio of non deleterious mutations in genes MLH1 and MSH2 was 65.22% of patients (30 alterations) and 50% of patients (23 alterations) respectively. Among patients with HNPCC, 23 potentially deleterious mutations were identified, via sequences of MLH1 and MSH2 with a 50% detection rate. It doesn't seem to appear variations in the clinical characteristics of the tumor when a germline mutation occurs in MLH1 or MSH2, with the exception of the relationship between the presence of mutation in the MLH1 gene and age of disease onset. As it occurs throughout the world, the disease present a his molecular extremely heterogeneoty, where only two mutations were repeated in two patients...
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Humans , Male , Female , Young Adult , Middle Aged , Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis , Clinical Diagnosis , Genes , MutationABSTRACT
Objective To explore the relationship between the expression of MutS homolog2 (MSH2) and CyclinD1 proteins in breast cancer and their clinical significance.Methods Expression of MSH2 and CyclinD1 proteins was detected in 67 cases of invasive ductal carcinoma of the breast by immunohistochemistry.Results The positive expression rate of MSH2 and CyclinD1 proteins was 53.7％ (36/67)and 47.8％ (32/67)respectively.The expression of MSH2 and CyclinD1 protein was closely related to lymph nodes metastasis(P ＜ 0.05).Expression of MSH2 and CyclinD1 protein was negatively correlated with each other in breast cancer(r =-0.251,P =0.040).Conclusion CyclinD1 may play a role in DNA mismatch repair(MMR) system by downregulating the expression of MSH2 and thus influences the tumorigenesis and progression of breast cancer.
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Aim: To obtain clinicopathological characteristics of colorectal cancer among young native Indonesians and to assess MLH1, MSH2, and SMAD4 protein expressions, comparing them with a matched population of colorectal cancer patients aged 60 years old and older. Methods: Medical records of colorectal cancer patients aged 40 years or younger and 60 years or older from several hospitals in three Indonesian cities – Jakarta, Makassar, and Bandung - were reviewed. The “native” ethnic groups were selected from those originating from Java, Makassar (South Celebes), Miinangkabau (West Sumatra). Ethnicity of 121 colorectal carcinoma patients was confirmed by fulfilling requirements in a questionnaire. Tumor specimens of those patients underwent evaluation for histopathology, tumor grading as well as immunohistochemical analysis to assess MLH1, MSH2 protein expressions to detect microsatellite instability mutation pathway and SMAD4 protein expression to reconfirm that the specimens were not microsatellite instability origin. Results: There were 121 colorectal carcinoma cases of Sundanese, Javanese, Macassarese and Minangkabau ethnic group. This study indicated that colorectal cancer has statistically different grade (p = 0.001) between the young and the older patients. Immunohistochemical staining for MSH2 protein and MLH1 were done for 92 and 97 specimens respectively. There was no significant difference between the expressions of MLH1 and MSH2 on tumor grading, indicated there was no correlation between microsatellite instability and tumor grading in this study. Conclusion: Colorectal cancer in young native Indonesian patients (40 years old or less) was not different in clinicopathological characteristics compared to older patients (60 years old or more) in similar ethnic groups. There was also no difference in MSH2 and MLH1 protein expressions, important indicators of microsatellite instability and.
Subject(s)
Colorectal Neoplasms , Microsatellite InstabilityABSTRACT
Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch Syndrome is an autosomic dominant syndrome involving 596-1096 of colorectal cancer patients. Mutations in MLH1 and MSH2 genes account for most cases. These two genes particípate in the DNA mismatch repair pathway. Therefore mutation carriers show microsatellite instability (MSI) in tumors. This syndrome is characterized by the early development of colorectal cancer (before 50 years) and an increased incidence of cancer in other organs. We report four siblings from a family diagnosed with HNPCC. All of them were subjected to colonic surgery for colorectal cancer Moreover, one patient developed an ampulloma after her colon surgery. The molecular-genetic analysis revealed three brothers with microsatellite instability in the tumor tissue, the absence of the MLH1 protein, and the presence of a germ Une mutation localized in introm 15 ofthe MLH1 gene.
Subject(s)
Adult , Female , Humans , Male , Adenocarcinoma/genetics , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , Mutation/genetics , Siblings , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Microsatellite Instability , Microsatellite Repeats , /genetics , /metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , PedigreeABSTRACT
Objective To investigate the role of methylated DNA mismatch repair gene MLH1 and MSH2 in the acquired multidrug-resistance of human small cell lung cancer cells H446.Methods The reverse transcription polymerase chain reaction(RT-PCR)and Western blot were applied to measure MLH1 and MSH2 mRNA and protein expressions of the multidrug-resistant cells H446/DDP and its parental cells H446.The promoter methylation status of the genes was assessed by methylation-specific PCR(MSP).Results The expressions of MLH1 and MSH2 significantly decreased both in mRNA level and protein level.Promoter methylation of MLH1 was observed in H446/DDP cells but not in H446 cells.Promoter semi-methylation of MSH2 in H446 cells was transformed to methylation in H446/DDP cells.Conclusion The downregulation of DNA mismatch repair gene MLH1 and MSH2 induced by its promoter methylation may play an important role in the acquired multidrug resistance of human small cell lung cancer.