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Objective:To explore KRAS, NRAS, BRAF gene mutations and microsatellite instability(MSI) in colorectal cancer tissues as well as their correlation with the clinicopathological characteristics of patients.Methods:The clinicopathological data of 473 colorectal cancer patients in Shanxi Province Cancer Hospital from October 2020 to May 2021 were retrospectively analyzed. The mutation status of KRAS, NRAS and BRAF gene in the paraffin tissues were detected by using amplification refractory mutation system (ARMS) method. Polymerase chain reaction (PCR)-capillary electrophoresis was used to analyze MSI status, and the correlation of the clinicopathological characteristics of patients with gene mutations and MSI status was analyzed.Results:The mutation rates of KRAS, NRAS and BRAF were 45.03% (213/473), 2.96% (14/473) and 5.50% (26/473), respectively in 473 patients with colorectal cancer. No case harbored both 2 gene mutations was detected. The mutation rate of KRAS gene in well differentiated adenocarcinoma was higher than that in poorly differentiated adenocarcinoma [47.4% (175/369) vs. 36.5% (38/104), χ2 = 3.89, P = 0.049]. NRAS mutation rate in female was higher than that in male [5.0% (10/202) vs. 1.5% (4/271), χ2 = 4.86, P = 0.027], and the NRAS mutation rate in patients with tumor diameter ≤ 3 cm was higher than that in those with tumor diameter >3 cm [7.1% (7/98) vs. 1.9% (7/375), P = 0.013]. BRAF mutation rate of tumors located in colon was higher than that in rectum [11.7% (20/171) vs.2.0% (6/302), χ2 = 19.81, P < 0.001]; BRAF mutation rate in poorly differentiated tumor was higher than that in well differentiated tumor [10.6% (11/104) vs. 4.1% (15/369), χ2 = 6.62, P = 0.010]; BRAF mutation rate in patients with mucus was higher than that in those without mucus [10.9% (11/101) vs. 4.0% (15/372), χ2 = 7.19, P = 0.007]; BRAF mutation rate in patients with lymphatic metastasis was higher than that in patients without lymphatic metastasis [8.2% (15/182) vs.3.8% (11/291), χ2 = 4.29, P = 0.038]. The incidence of high frequency MSI (MSI-H) in 473 colorectal cancer tissues was 7.19% (34/473). The incidence of MSI-H in colon was higher than that in rectum [14.0% (24/171) vs. 3.3% (10/302), χ2 = 18.82, P < 0.001]; the incidence of MSI-H in patient with poor differentiated tumor was higher than that in those with well differentiated tumor [17.3% (18/104) vs. 4.3% (16/369), χ2 = 20.46, P < 0.001]; the incidence of MSI-H in patients with mucus was higher than that in those without mucus [11.9% (12/101) vs. 5.9% (22/372), χ2 = 4.24, P = 0.039]; and the incidence of MSI-H in patients without lymphatic metastasis was higher than that in patients with lymphatic metastasis [10.0% (29/291) vs. 2.7% (5/182), χ2 = 8.75, P = 0.003]. In addition, the incidence of MSI-H was on the rise in patients with BRAF mutation ( P < 0.001). Conclusions:KRAS, NRAS, BRAF gene mutations and MSI status are correlated with the clinicopathological characteristics of patients with colorectal cancer; there is a close relationship between MSI-H and BRAF mutation.
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Objective To assess the relationship between BRAF gene mutations and clinical phenotype of malignant melanoma.Methods Tissue specimens were collected from the lesions of 80 patients with malignant melanoma,and from the normal skin of 30 patients with trauma in the Department of Plastic Surgery or General Surgery,and subjected to paraffin embedding and DNA extraction.PCR was performed to amplify the exon 11 and 15 of BRAF gene followed by DNA sequencing.Chi-square test and Fisher's exact test were carried out to assess the relationship between BRAF gene mutations and clinical phenotypes of malignant melanoma.Results BRAF gene mutations were found in 19 (23.8％) of the 80 malignant melanoma specimens.Among the 19 mutationpositive specimens,17 (88.2％) carried mutations in exon 15 of BRAF gene with V600E as the most frequent (88.2％,15/17) mutation type,and 2 (10.5％) carried mutations in exon 11.No mutation was found in any of the normal skin tissue specimens.The average age at onset was 57.5 years in these patients.The frequency of BRAF gene mutation was significantly higher in patients younger than 60 years than in those older than 60 years (37.1％ vs.13.3％,x2=6.613,P ＜ 0.05).A significant difference was observed in the frequency of BRAF gene mutation among tissue specimens of mueosal,acral and non-aeral malignant melanoma (18.2％ (4/21) vs.14.7％(5/34) vs.41.7％ (10/24),x2=6.167,P ＜ 0.05).There was no significant association between BRAF gene mutation and gender,race or lymph node metastasis (all P ＞ 0.05).Conclusions BRAF gene is a hot spot for mutations in patients with malignant melanoma in Xinjiang Uygur Autonomous Region,with V600E point mutation in exon 15 as the most frequent mutation type.BRAF gene mutations appear to be closely correlated with the age at onset of and lesional sites in,but uncorrelated with gender and race of or lymph node metastasis in,patients with malignant melanoma.
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BACKGROUND: Recent studies reported that BRAF V600E mutation, the most prevalent genetic event found in papillary thyroid carcinoma, is an independent poor prognostic marker. Additionally, it correlates with a less differentiated tumor stage due to reduced expression of key genes involved in iodine metabolism. We previously described a patient with BRAF V600E mutation in primary tumor and a new mutation (V600E+K601del) in the matched-lymph node metastases. In the present study we report an unusual clinical behavior of PTC and correlate with BRAF mutational status and level of expression of TSHR and NIS. METHODS: Quantitative PCR (qPCR) was used to evaluate the NIS and TSHR level of expression in matched papillary thyroid carcinoma and adjacent normal tissue. RESULTS: In this study, we presented a seven-year follow up of a juvenile papillary thyroid carcinoma patient who had an aggressive tumor harboring BRAF mutation, and failed to conventional therapy. We found a markedly decrease of NIS and TSHR expression in primary PTC compared to adjacent normal thyroid tissue. CONCLUSION: Our findings suggest that BRAF mutational status and decreased NIS and TSHR expression in this patient may reduce radioiodine uptake and lead to a negative response to radioiodine therapy.
INTRODUÇÃO: Estudos recentes demonstraram que a mutação V600E no gene BRAF é o evento genético mais freqüentemente encontrado em carcinoma papilífero da tiróide e um marcador de prognóstico independente. Adicionalmente, esta alteração genética tem sido correlacionada com a redução de expressão de genes envolvidos no metabolismo do iodo. Previamente, nosso grupo descreveu uma paciente com a mutação V600E no gene BRAF no tumor primário e uma mutação nova (V600E+K601del) em metástases pareadas. Neste estudo, reportamos um carcinoma papilífero com um comportamento clínico incomum e correlacionamos com a presença de mutação no gene BRAF e os níveis de expressão de TSHR e NIS. MÉTODO: Análise de expressão dos genes NIS e receptor de TSH (TSHR) através da técnica de PCR em tempo real. RESULTADOS: Descrevemos sete anos de acompanhamento de uma paciente jovem que apresentava um tumor com comportamento agressivo e baixa resposta aos tratamentos convencionais. Uma acentuada diminuição da expressão do TSHR e a ausência de expressão de NIS foram observadas no tumor primário desta paciente quando comparada com o tecido tiroidiano normal adjacente. CONCLUSÃO: Nossos dados sugerem que as mutações encontradas nesta paciente no gene BRAF com conseqüente perda de expressão dos genes NIS e TSHR podem ter reduzido a captação de iodo radioativo e a resposta ao tratamento.