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Chile has two certified origin olive products: Extra-Virgin Olive Oil (EVOO) from Huasco valley and the Azapa variety table olive from the Azapa valley. However, efficient methodologies are needed to determine the varieties and raw materials involved in the end products. In this study, we assessed the size of alleles from ten microsatellites in 20 EVOOs and in leaves and fruits of 16 olive varieties cultivated in Chile to authenticate their origins. The identification of varieties relied on specific allele sizes derived from microsatellites markers UDO99-011 and DCA18-M found in leaves and fruit mesocarp. While most Chilean single-variety EVOOs matched the variety declared on the label, inconsistencies were observed in single-variety EVOOs containing multiple varieties. Our findings confirm that microsatellites serve as a valuable as diagnostic tools for ensuring the quality control of Geographical Indication certification for Azapa olives and EVOO with Designation of Origin from Huasco.
Chile cuenta con dos productos de oliva de origen certificado: El aceite de oliva virgen extra (AOVE) del valle del Huasco y la aceituna de mesa de la variedad Azapa del valle de Azapa. Sin embargo, se necesitan metodologías eficientes para determinar las variedades y materias primas involucradas en los productos finales. En este estudio, evaluamos el tamaño de los alelos de diez microsatélites en 20 AOVEs y en hojas y frutos de 16 variedades de aceituna cultivadas en Chile para autentificar sus orígenes. La identificación de las variedades se basó en los tamaños alélicos específicos derivados de los marcadores microsatélites UDO99-011 y DCA18-M encontrados en las hojas y el mesocarpio de los frutos. Aunque la mayoría de los AOVEs chilenos monovarietales coincidían con la variedad declarada en la etiqueta, se observaron incoherencias en los AOVEs monovarietales que contenían múltiples variedades. Nuestros hallazgos confirman que los microsatélites sirven como valiosas herramientas de diagnóstico para asegurar el control de calidad de la certificación de Indicación Geográfica para aceitunas de Azapa y AOVE con Denominación de Origen de Huasco.
Subject(s)
Olive Oil/chemistry , Geography , Plant Extracts/chemistry , Chile , Plant Structures/chemistryABSTRACT
Context: Globally, colorectal carcinoma (CRC) ranks the third most commonly diagnosed malignant disease, one of the leading causes of cancer deaths. Aims: To study the spectrum of clinicopathological characteristics of sporadic colorectal carcinoma and to assess mismatch repair gene deficiency by the expression pattern of the proteins assessed by immunohistochemistry. Setting and Design: Observational study conducted in a tertiary care hospital in West Bengal. Materials and Methods: Fifty-two surgically resected specimens of CRC received from January 2018 to May 2019 were studied for clinical, morphological, MSI status. Statistical Analysis Used: IBM SPSS 23. Results: A total of 50% of the cases belonged to younger and 50% to the older population, with male predominance being 53.8%. The most common histologic type was adenocarcinoma (88.5%). The majority was found to be well-differentiated carcinoma (50%). The majority cases were of the T3 stage accounting to 38.5%. A total of 24 out of 52 cases (46.15%) had an absent expression of at least one mismatch repair (MMR) protein. A significant correlation was found between the young age group and microsatellite instability (MSI) with a P value of 0.001. A significant association was found between MSI and tumor differentiation with P value of 0.018. A significant association was found between MSH6 and histological type with P value of 0.012. A significant association was found between MSI and tumor stage with P value of 0.032. Conclusions: This study shows a significantly higher number of sporadic colon cancers involving the young age group, and younger cases showed significant association with MSI. This alarming trend needs validation by studies involving larger populations and can be helpful prognostically as well as in formulating chemotherapeutic regimens.
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OBJECTIVE To evaluate the clinical efficacy and safety of XELOX chemotherapy （oxaliplatin+capecitabine） combined with antiangiogenic agent （apatinib） and immunotherapy （camrelizumab） in patients with inoperable metastatic colorectal cancer （CRC）of microsatellite stable （MSS） type. METHODS Clinical medical records of 40 patients with inoperable metastatic CRC of MSS type treated in Lishui People’s Hospital from January 2020 to January 2021 were retrospectively collected. According to the treatment plan， the patients were divided into control group （20 cases） and observation group （20 cases）. Control group was given XELOX+apatinib regimen， while observation group was given XELOX+apatinib+camrelizumab regimen. Every 3 weeks was a treatment cycle， and the treatment lasted for 2 consecutive cycles. The objective response rate （ORR）， disease control rate （DCR）， progression-free survival （PFS）， overall survival （OS） and adverse events （AEs） were recorded for all patients. RESULTS The ORR and DCR of observation group were 65.0% and 85.0%， respectively； and the ORR and DCR of control group were 35.0% and 75.0%， respectively， with no statistical significance between 2 groups （P＞0.05）. The median PFS of observation group and control groups were 16.0 months and 8.0 months， respectively； and the median OS were 19.0 months and 12.5 months， respectively， with statistical significance between 2 groups （P＜0.05）. Each patient in both groups had at least one AEs， and the incidences of reactive skin capillary hyperplasia and hyperthyroidism in observation group （40.0%， 20.0%） were significantly higher than those in control group （both were 0） （P＜0.05）. The incidence of nausea and vomiting in control group （90%） was significantly higher than observation group （10%） （P＜0.05）. There were 14 cases （70.0%） of patients with grade 3 or above AEs in observation group， and only 5 cases （25.0%） in control group， with statistical significance between 2 groups （P＜0.05）. However， no severe AEs that could not be tolerated or fatal occurred in the two groups， which could be alleviated after drug withdrawal or treatment. CONCLUSIONS The efficacy of XELOX chemotherapy combined with apatinib and camrelizumab in inoperable metastatic CRC patients of MSS type is comparable to that of XELOX chemotherapy combined with apatinib， but it has certain advantages in ORR， PFS and OS， and controllable safety.
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Objective:To investigate the predictive value of multimodal magnetic resonance imaging (MRI) based radiomics model for microsatellite instability (MSI) of rectal cancer.Methods:The retrospective cohort study was conducted. The clinicopathological data of 117 patients with rectal cancer who were admitted to 2 medical centers, including 74 in Ningbo Urology & Nephrology Hospital and 43 in the First Affiliated Hospital of Zhejiang University School of Medicine, from January 2020 to December 2022 were collected. There were 73 males and 44 females, aged (63±5)years. Based on random number table, all 117 patients were divided into the training dataset of 70 cases and the test dataset of 47 cases with a ratio of 7:3. All patients underwent pelvic MRI exami-nation. Observation indicators: (1) construction of radiomics prediction model and analysis of charac-teristics; (2) analysis of factors influencing MSI of rectal cancer in the training dataset; (3) construc-tion and evaluation of the prediction model for MSI of rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and compari-son between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test. Univariate analysis was conducted using the one way ANOVA and multivariate analysis was conducted using the Logistic regression model with forward method. The receiver operating characteristic curve was drawn, and the area under the curve (AUC), decision curve, calibration curve and Delong test were used to evaluate the predictive ability of prediction model. Results:(1) Construction of radiomics prediction model and analysis of characteristics. Five thousand five hundred and eighty radiomics features were finally extracted from the 117 patients. Based on the feature selection using the maximum correlation minimum redundancy method, and the least absolute shrinkage and selection operator fitting algorithm, 9 radiomics features were finally selected. The radiomics prediction model was constructed based on calculation of the radiomics score. (2) Analysis of factors influencing MSI of rectal cancer in the training dataset. Results of multivariate analysis showed that platelet count was an independent influencing factor for MSI of rectal cancer [ odds ratio=1.13, 95% confidence interval ( CI) as 1.06-1.21, P<0.05]. (3) Construction and evaluation of the prediction model for MSI of rectal cancer. The clinical prediction model and clinical-radiomics combined prediction model were constructed based on the results of multivariate analysis. The AUC of clinical prediction model, radiomics prediction model, clinical-radiomics combined prediction model in the training dataset was 0.94 (95% CI as 0.86-0.98), 0.96 (95% CI as 0.88-0.99), 0.99 (95% CI as 0.93-1.00), respectively, with the sensitivity and specificity as 90.7%, 91.2%, 96.9% and 85.0%, 88.9%, 94.3%. Results of Delong test showed that there was a significant difference in the predictive performance between the clinical-radiomics combined prediction model and the clinical prediction model ( Z=2.20, P<0.05), and there was no significant difference between the radiomics prediction model and the clinical-radiomics combined prediction model or the clinical prediction model ( Z=1.94, 0.60, P>0.05). The AUC of clinical prediction model, radiomics prediction model, clinical-radiomics combined prediction model in the test dataset was 0.97 (95% CI as 0.88-1.00), 0.86 (95% CI as 0.73-0.95), 0.97(95% CI as 0.87-1.00), respectively, with the sensitivity and specificity as 99.3%, 95.8%, 99.3% and 85.7%, 73.9%, 90.5%. Results of Delong test showed that there was a significant difference in the predictive performance between the clinical-radiomics combined prediction model and the radiomics prediction model ( Z=2.21, P<0.05), and there was no significant difference between the clinical prediction model and the clinical-radiomics combined prediction model or the radiomics prediction model ( Z=0.17, 1.82, P>0.05). Results of calibration curve showed that clinical prediction model, radiomics prediction model, clinical-radiomics combined prediction model had good ability in predicting the MSI status of rectal cancer. Results of decision curve showed that compared to clinical prediction model and radiomics prediction model, clinical-radiomics combined prediction model had greatest net gain in predicting the MSI of rectal cancer. Conclusion:The prediction model based on 9 radiomics features after selecting can effectively predict the MSI status of rectal cancer, and the clinical-radiomics combined prediction model has a better prediction efficiency.
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Colorectal cancer (CRC) is one of the most common gastrointestinal cancers. The incidence and mortality of CRC are still rising in China. It is of great importance to explore the molecular mechanisms of the development and progression of CRC. Microsatellites are short tandem repeats that are distributed throughout the genome. Detection of microsatellite instability (MSI) is of great value in the diagnosis and treatment of CRC. MSI detection is an important method for Lynch syndrome screening. For patients with stage Ⅱ CRC, MSI status is an influencing factor for post-operative recurrence and an important reference for adjuvant therapy. For patients with stage Ⅳ CRC, MSI status is an important indicator for screening potential patients suitable for treatment of immune checkpoint inhibitors. However, there are still problems concerning the application of MSI. The detection methods of MSI have not been fully unified. The requirement of MSI detection in CRC patients are universal but not precise. MSI is not a valid predictor for the prognosis of CRC patients, and it could not effectively predict the efficacy of chemotherapy and immunotherapy. Moreover, with the application of other molecular markers, such as programmed death-1, programmed death-ligand 1, tumor mutation burden and immunoscore, the value of MSI in CRC is being challenged and remains to be unveiled with more studies. The authors investigate the problems in MSI detection and application, in order to provide reference for clinical practice.
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Pancreatic cancer (PC) is a malignant digestive tract tumor with poor prognosis. Most of patients with PC are insensitive to traditional strategies of chemotherapy, targeted therapy and immunotherapy. PC with microsatellite instability-high/deficient mismatch repair (MSI-H/dMMR) is rare in clinic, which has distinctive clinicopathological characteristics and better prognosis from conventional PC. Reasonable acquisition of pancreatic tumor biopsy and accurate assessment of MSI-H/dMMR status are helpful for accurate diagnosis of such patients. Individualized treatment strategy based on immunotherapy can significantly improve the prognosis of patients with MSI-H/dMMR PC. Based on relevant literatures of domestic and foreign, the authors discuss the current status and research hotspots of diagnosis and treatment for MSI-H/dMMR PC.
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In recent years, immunotherapy, especially immune checkpoint inhibitors, has shown obvious advantages in prolonging the survival of patients with advanced tumors, and the tumor microenvironment is one of the important factors affecting the efficacy of immunity. Patients with microsatellite-stable colorectal cancer exhibit immune responses in combination with immune checkpoint inhibitor therapy. In-depth exploration of the tumor microenvironment characteristics of microsatellite-stable colorectal cancer and the application of combined immune checkpoint inhibitor therapy can provide new ideas and directions for colorectal cancer immunotherapy.
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OBJECTIVE@#To analyze the differences and characteristics of microsatellite instability (MSI) in endometrial cancer (EMC), by using colorectal cancer (CRC) as control.@*METHODS@#In the study, 228 cases of EMC were collected. For comparative analysis, 770 cases of CRC were collected. Mismatch repair (MMR) expression was detected by immunohistochemistry (IHC), and microsatellite instability (MSI) was analyzed by PCR and capillary electrophoresis fragment analysis (MSI-PCR). MSI-PCR was detected using five mononucleotide repeat markers: BAT-25, BAT-26, NR-21, NR-24, and MONO-27.@*RESULTS@#In EMC, we found 27.19% (62/228) of deficient mismatch repair (dMMR) using IHC, significantly higher than CRC (7.79%, 60/770). Meanwhile, subclonal expression of MMR protein was found in 4 cases of dMMR-EMC and 2 cases of dMMR-CRC. According to the criteria of major micro-satellite shift, we found 16.23% (37/228) of MSI-high (MSI-H), 2.63% (6/228) of MSI-low (MSI-L), and 81.14% (185/228) of microsatellite stability (MSS) in EMC using MSI-PCR. The discor-dance rate between MMR-IHC and MSI-PCR in EMC was 11.84% (27/228). In CRC, we found 8.05% (62/770) of MSI-H, 0.13% (1/770) of MSI-L, and 91.82% (707/770) of MSS. The discordance rate between MMR-IHC and MSI-PCR in CRC was only 0.52% (4/770). However, according to the criteria of minimal microsatellite shift, 12 cases of EMC showed minimal microsatellite shift including 8 cases of dMMR/MSS and 4 cases of dMMR/MSI-L and these cases were ultimately evaluated as dMMR/MSI-H. Then, 21.49% (49/228) of EMC showed MSI-H and the discordance rate MMR-IHC and MSI-PCR in EMC decreased to 6.58% (15/228). No minimal microsatellite shift was found in CRC. Compared with EMC group with major microsatellite shift, cases with minimal microsatellite shift showed younger age, better tumor differentiation, and earlier International Federation of Gynecology and Obstetrics (FIGO) stage. There were significant differences in histological variant and FIGO stage between the two groups (P < 0.001, P=0.006).@*CONCLUSION@#EMC was more prone to minimal microsatellite shift, which should not be ignored in the interpretation of MSI-PCR results. The combined detection of MMR-IHC and MSI-PCR is the most sensitive and specific method to capture MSI tumors.
Subject(s)
Female , Humans , Microsatellite Instability , Colorectal Neoplasms , Microsatellite Repeats , Endometrial Neoplasms , DNA Mismatch RepairABSTRACT
The exploration of biomarkers predicting response to immune checkpoint inhibitors in microsatellite stability colorectal cancer can enable more patients to benefit from immunotherapy. Tumor mutational burden (TMB), POLE/POLD1 mutation, CMS classifications, MGMT methylation, and other indicators own the potential and value of predicting response to immune checkpoint inhibitors in microsatellite stability colorectal cancer. In this paper, we reviewed the related research on predictive biomarkers of immune checkpoint inhibitors in microsatellite stability colorectal cancer, provide a reference for the best treatment strategy for microsatellite stability colorectal cancer.
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ABSTRACT BACKGROUND: Part of colorectal cancer cases occurs due to modifications in the DNA mismatch repair system, which are responsible for microsatellite instability. This alteration results in an unconventional phenotypic pattern of colorectal cancer. AIMS: To describe the epidemiological, histopathological and molecular profiles of patients with colorectal cancer who underwent surgical treatment in a reference hospital. METHODS: This is a cross-sectional, retrospective study with a quantitative approach, that included a review of patients' medical records who underwent oncological surgery for colorectal cancer. RESULTS: A total of 122 colorectal cancer cases were identified, with microsatellite instability detected in 8.2% of the sample. The gender distribution was similar, with 52.46% males, and the weighted average age was 63 years (standard deviation±11.65). However, in the microsatellite instability group, the predominant age was below 60 years. Regarding the histological type, adenocarcinoma not otherwise specified accounted for 80.33% of the cases, being the most prevalent in both groups, with the mucinous type being more frequent among the instability cases. The pT3 pathological staging (46.72%) was the most predominant. The topography was more prevalent on the left (60.66%), but there was a significant difference when compared to the group with microsatellite instability, in which 80% of the neoplasms were located on the right (p=0.006). CONCLUSIONS: Differences in age and neoplastic topography found in microsatellite instability samples highlight the distinctive presentation pattern of the disease. Recognizing these characteristics is essential for developing prevention strategies, in addition to early and accurate diagnosis of colorectal cancer.
RESUMO RACIONAL: Parte dos casos de câncer colorretal ocorre devido a alterações nas enzimas de reparo do DNA, responsáveis pela instabilidade de microssatélites. Esta alteração resulta em um padrão fenotípico não convencional de câncer colorretal. OBJETIVOS: Descrever os aspectos epidemiológicos, histopatológicos e moleculares dos pacientes com câncer colorretal submetidos a tratamento cirúrgico em hospital de referência. MÉTODOS: Trata-se de um estudo transversal, retrospectivo com abordagem quantitativa, com revisão de prontuários médicos de pacientes submetidos a cirurgia oncológica por câncer colorretal. RESULTADOS: Foram registrados 122 casos de câncer colorretal, com instabilidade de microssatélites detectada em 8,2% da amostra. A distribuição por sexo foi semelhante, sendo 52,46% do sexo masculino, e média ponderada de idade de 63 anos (±11,65), contudo no grupo com instabilidade, a faixa etária predominante foi abaixo de 60 anos. Em relação ao tipo histológico, o adenocarcinoma sem outra especificação representou 80,33% dos casos, sendo o mais prevalente em ambos os grupos, mas com maior frequência do tipo mucinoso em caso de instabilidade. O estadiamento patológico pT3 (46,72%) foi predominante. A topografia da neoplasia foi mais prevalente à esquerda (60,66%), mas houve diferença significativa em relação ao grupo com instabilidade de microssatélites, no qual 80% das neoplasias localizavam-se à direita (p=0,006019). CONCLUSÕES: As diferenças de idade e topografia neoplásica encontradas nas amostras com instabilidade de microssatélites destacam o padrão não habitual de apresentação da doença. O conhecimento, portanto, dessas distinções é necessário para o desenvolvimento de estratégias de prevenção, além de diagnóstico precoce e preciso do câncer colorretal.
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Objective To investigate the clinical efficacy and safety of fruquintinib combined with sintilimab in the treatment of advanced microsatellite stable (MSS) colorectal cancer. Methods A retrospective study of 44 patients with MSS colorectal cancer treated with fruquintinib and sintilimab was conducted.The patients were divided into the fruquintinib alone (n=22) and fruquintinib combined with sintilimab (n=22) groups.The treatment regimen was as follows: The patients in the fruquintinib alone group consumed oral fruquintinib capsules at 5 mg/d once for three consecutive weeks with a one week stop in 28 day cycles.The patients in the fruquintinib combined sintilimab group were injected intravenously with sintilimab (200 mg) once per three weeks, and fruquintinib was used in the same manner as the fruquintinib alone group. Results The objective response rate (ORR) of the fruquintinib alone group was 9.09%, the disease control rate (DCR) of the fruquintinib alone group was 45.45%.The ORR of the fruquintinib combined with sintilimab group was 18.18%, and the DCR was 63.64%.The median PFS of the fruquintinib alone and fruquintinib combined with sintilimab groups were 4.4 months (IQR: 2.1-8.2) and 6.7 months (IQR: 3.9-12.6), respectively (χ2=4.372, P=0.037).Most of the adverse reactions during the treatment of the two groups were grades 1-2.In addition, no significant difference in the incidence of adverse reactions was found between two groups (P > 0.05). Conclusion Compared with fruquintinib alone, fruquintinib combined with sintilimab in the treatment of patients with MSS colorectal cancer after the failure of standard treatment has better clinical efficacy, and adverse drug reactions can be controlled.
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Objective:To explore the status of microsatellite instability (MSI) and its relationship with clinicopathological characteristics of patients with endometrial carcinoma.Methods:The clinical data of 365 patients with endometrial carcinoma who received surgery in Shanxi Province Cancer Hospital between January 2020 and December 2021 were retrospectively analyzed. Immunohistochemistry was used to detect the expressions of 4 DNA mismatch repair (MMR) proteins (MLH1, MSH2, MHS6, and PMS2), estrogen receptor (ER), progesterone receptor (PR), and p53 mutant protein in postoperative cancer tissue samples from 365 patients with endometrial carcinoma. All patients were divided into MSI group (1 or more non-expression of MMR protein) and microsatellite stability (MSS) group (4 proteins were all expressed), and the clinicopathological characteristics of patients in both groups were compared. φ efficient was used to analyze the correlation of MSI with ER, PR, p53 mutant protein expressions. Results:There were 72 cases (19.7%) in MSI group and 293 cases (80.3%) in MSS group; and the age of all patients was (53±19) years (21-83 years). There were statistically significant differences in the proportion of MSI patients in endometrial carcinoma patients with different age [>50 years vs. ≤50 years: 22.1% (61/276) vs. 12.4% (11/89)], tumor diameter [≤2 cm vs. > 2 cm: 25.9% (30/116) vs. 16.8% (42/249)], International Federation of Gynecology and Obstetrics (FIGO) staging [stage Ⅲ-Ⅳ vs. stage Ⅰ-Ⅱ: 31.1% (14/45) vs. 18.1% (58/320)], histological type [type Ⅰ vs. type Ⅱ: 21.7% (71/327) vs. 2.6% (1/38)] (all P < 0.05). There were no statistically significant differences in the proportion of MSI patients with different depth of invasion, degree of differentiation, lymph node metastasis, vascular involvement, and lesion location (all P > 0.05). Among 327 cases of type Ⅰendometrial carcinoma, 1 case was mucinous adenocarcinoma (MSS status), and the other 326 cases were endometrioid adenocarcinoma. Of the 72 patients with MSI, 71 cases were endometrioid carcinoma and the other was 1 of 3 mixed carcinomas in type Ⅱ endometrial carcinoma. There was a negative correlation between MSI and mutant p53 ( φ coefficient was -0.11, P = 0.031), and φ coefficient of the correlation of MSI with ER and PR was -0.03 and -0.06, while there were no statistically significant differences ( P value was 0.578 and 0.255, respectively). Conclusions:Endometrioid adenocarcinoma is the main type of endometrial cancer patients with MSI. MSI in endometrial cancer is correlated with age, FIGO staging, tumor diameter and histological type of patients, while negatively correlated with mutant p53.
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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 investigate the relationship between microsatellite instability (MSI) , and clinicopathological features ,prognosis in patients with stage Ⅱ and Ⅲ colon cancer.Methods:Patients undergoing surgical resection for stage Ⅱ and Ⅲ colonic tumor in the Affiliated Hospital of Qingdao University from Dec 2016 to Nov 2018 were enrolled. All the 292 patients were with stage Ⅱ and Ⅲ colon cancer and MSI status. Propensity score matching method was used to match the two groups of patients according to 1:1. χ 2 analysis, Logistic Regression and COX regression was used to analyse the relationship between MSI status, the clinicopathological features and prognosis. Results:The risk of MSI-H in young patients ( OR=0.340, 95% CI: 0.126~0.921, P=0.034), right-sided colon cancer ( OR=7.985, 95% CI: 3.040-20.973, P<0.001), mucinous adenocarcinoma ( OR=4.285, 95% CI: 1.495-12.284, P=0.007), poorer differentiation ( OR=4.848, 95% CI: 1.597-14.716, P=0.005), N0 staging ( OR=0.235 , 95% CI: 0.077-0.719, P=0.011) increased . The total OS of colon cancer patients in the MSS group (66.7%) and the MSI-H group (86.9%) were statistically different( P=0.003). The MSI status ( HR=0.367, 95% CI: 0.151-0.891, P=0.027) is an independent factor affecting the prognosis of patients. Conclusions:In stage Ⅱ and Ⅲ colon cancer, patients with MSI-H have a better prognosis. MSI status is prognosis relevant factor for colon cancer patients.
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Abstract Introduction: The natural ecosystems of northern Mato Grosso, Brazil, are in process of fragmentation, mainly due to population growth and the expansion of agriculture. This endangers the palm Euterpe precatoria (locally known as açaí), used for construction, palm hearts, juices and ice cream. Objective: To evaluate the local diversity and genetic structure in native populations of E. precatoria. Methods: We collected leaves from 106 fruiting palms from five populations in Mato Grosso State, for analysis of microsatellite markers with Polymerase Chain Reaction. Results: The five SSR loci revealed a total of 30 alleles, ranging from 5 (EE23 and EE43) to 7 (EE2 and EE15), with an average of 6 alleles per locus. The mean PIC was 0.74 and confirmed low heterozygosity and inbreeding. The UPGMA dendrogram produced two groups and molecular variance revealed greater genetic differentiation within populations. The high levels of homozygous microsatellite loci indicate low genetic diversity. Conclusions: These populations have low gene diversity, high average number of alleles per locus, and rare and exclusive alleles. We recommend the establishment of permanent conservation units with corridors among them.
Resumen Introducción: Los ecosistemas naturales del norte de Mato Grosso, Brasil, están en proceso de fragmentación, principalmente debido al crecimiento de la población y la expansión de la agricultura. Esto pone en peligro la palma Euterpe precatoria (localmente conocida como açaí), utilizada para la construcción, extracción de palmito, preparación de jugos y helados. Objetivo: Evaluar la diversidad local y estructura genética en poblaciones nativas de E. precatoria. Métodos: Recolectamos hojas de 106 palmas fructíferas de cinco poblaciones en el estado de Mato Grosso, para análisis de marcadores microsatélites con el método de Reacción en Cadena de la Polimerasa (PCR). Resultados: Los cinco loci SSR revelaron un total de 30 alelos, que van desde 5 (EE23 y EE43) hasta 7 (EE2 y EE15), con un promedio de 6 alelos por locus. El PIC medio fue de 0.74 y confirmó baja heterocigosidad y endogamia en las poblaciones. El dendrograma UPGMA produjo dos grupos y la varianza molecular reveló una mayor diferenciación genética dentro de las poblaciones. Los loci de microsatélites presentaron un alto nivel de homocigotos lo que indica una baja diversidad genética. Conclusiones: Estas poblaciones tienen baja diversidad genética, alto promedio de alelos por locus y alelos raros y únicos. Recomendamos el establecimiento de unidades de conservación permanentes con corredores entre ellas.
Subject(s)
Arecaceae/classification , Euterpe/classification , BrazilABSTRACT
Background and Objective: Plantain (Musa paradisiaca L) remains one of themost important staple food crop and perhaps, one of the oldest cultivated fruit tree crop in the humid tropics of Africa, Central Asia, South America and the West Indies.Fourteen (14) elite plantain cultivars were evaluated for genetic diversity using agro-morphological yield related attributes and simple sequence repeat (SSR) markers. Materials and Methods: Six (6) microsatellite markers that showed distinct fragments varying from 50 bp to 3.0 Kbp in size of polymorphic bands were selected and used for molecular characterization and fingerprinting, while agro-morphological (yield杛elated) attributes assessed included bunch weight, number of hands/bunch, number of fingers/hands, number of fingers/bunch, harvest interval, length of plant cycle, pulp hardness and pulp to skin weight ratio of the elite plantain cultivars. Results: The total number of amplified bands (TNB), mean percentage polymorphism (%P), mean polymorphic information content (PIC), average marker index (MI) and mean gene diversity for the SSR assay were 59, 70.24%, 0.79, 3.74 and 0.832 respectively. Results of agro-morphological fingerprint study revealed a significant variations in terms of the bunch weight, number of finger per hands/bunch, number of fingers per hand, number of fingers /bunch, harvest interval, length of crop cycle, pulp hardness and pulp/wt. ratio all showed significant variations among the cultivars. The distribution of the elite cultivars along with the principal components showed cluster pattern of distribution within the study location. Principal component analysis revealed four principal components contributing 99.91% to the observed morphological variations while analysis of molecular variance revealed 96.00% contributed by molecular characteristics to observed variations. The yield displayed revealed significant contributions of bunch weight, fingers/hand and fingers/bunch as the main indices for plantain yield. The dendrograms for both morphological and molecular characteristics delineated the cultivars into four distinct cluster groups and subgroups each varying in genetic distance. Conclusion: These good cultivars can be exploited for the improvement of low yielding cultivars in other region to increase and improve plantain yield, promote food security and income generation especially under the present economic realities where food security is threatened by the global food crises and declining crop productivity.
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RESUMEN A partir de visualización por electroforesis capilar de 9 regiones micro-satélites amplificadas con cebadores fluoromarcados se determinó el polimorfismo de los marcadores Hmct5, 102, HV 30, 548, HV 15, 416, m574, 103 y 358 identificados en el ADN de muestras de tejido foliar de 12 clones de caucho (Hevea brasiliensis) conservados en jardines clonales de AGROSAVIA en Colombia y 25 clones en jardines clonales de origen en Brasil. Con base en los resultados del análisis se consolidó una base de datos que permite corroborar la identidad por conformidad de clones de caucho a partir de muestras foliares. El protocolo establecido consiste en una aproximación metodológica para la amplificación de dichas regiones micro-satélites por PCR punto final y la visualización de los fragmentos obtenidos de este procedimiento por electroforesis capilar multiplexada, reduciendo costos y optimizando el tiempo en laboratorio. Adicionalmente se encontraron discrepancias entre el perfil electroforético obtenido del clon FX 3864 muestreado en Colombia con el obtenido en Brasil. Se propone considerar la necesidad de corroborar la identidad de los clones reproducidos en jardines clonales para su comercialización en Colombia, utilizando metodologías sensibles y reproducibles, como la estandarizada en este estudio.
ABSTRACT The polymorphism of 9 regions identified in the DNA of leaf tissue sampled from 12 rubber clones conserved in clonal gardens of AGROSAVIA in Colombia and 25 clones in clonal gardens of origin in Brazil was visualized by capillary electrophoresis after amplification with the fluorolabeled primer microsatellite markers Hmct5, 102, HV 30, 548, HV 15, 416, m574, 103 and 358. Upon the results analysis, a database was consolidated that allows to corroborate the genetical identity by conformity with 37 rubber clones from leaf samples. The established protocol is a methodological approach using end-point PCR towards the amplification by multiplexed capillary electrophoresis of micro-satellite regions and their visualization, reducing costs and optimizing time in the laboratory. Additionally, discrepancies were found between the electrophoretic profile obtained from clone FX 3864 sampled in Colombia with that obtained in Brazil. It is proposed to consider the need to corroborate the identity of the clones reproduced in clonal gardens for their commercialization in Colombia, using sensitive and reproducible methodologies, such as the one standardized in this study.
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RESUMEN La materia prima del fitomejoramiento es la variabilidad genética, que se presenta baja, en especies en proceso de domesticación, que no han sido sometidas a selección, como en Solanum betaceum. Una de las tecnologías para incrementar la variabilidad genética es la inducción de mutagénesis. El objetivo del estudio fue evaluar, a través de marcadores RAMs, las variaciones moleculares presentes en plántulas de S. betaceum, provenientes de semillas sometidas a diferentes concentraciones del agente mutante dietil sulfato (DES). Los loci polimórficos oscilaron entre 87,5 y 100 % y el número de alelos efectivos (Ne), entre 1,0 y 1,99. Los loci más polimórficos se observaron en TG, AG, ACA y CGA, que mostraron una heterosis media insesgada entre 0,34 y 0,51, que permite establecer que estos marcadores sean útiles para obtener mayor discriminación entre mutantes en S. betaceum. Las distancias genéticas oscilaron entre 0,30 y 1,0. El 81,28 % de estos registros se dieron entre 0,60 y 0,90; esto revela bajo nivel de cambios, debido al DES. Estos pequeños cambios contribuyeron a enriquecer la variabilidad genética de la muestra tratada con DES. Los marcadores RAMs fueron útiles para detectar cambios entre plantas provenientes de semillas tratadas con DES y plantas normales. La variabilidad genética entre tratamientos con DES fueron más altos que tratamientos sin DES. Las similitudes genéticas fueron bajas entre plantas tratadas y no tratadas y fueron altas, entre no tratadas. Los cambios producidos por DES fueron de baja magnitud; sin embargo, produjeron cambios en los niveles de variabilidad genética.
ABSTRACT The raw material for plant breeding is genetic variability, which is low in species in the process of domestication that have not been subjected to selection, as is the case with Solanum betaceum. One of the technologies to increase genetic variability is mutagenesis induction. The objective was to evaluate, through RAMs markers, the molecular variations present in S. betaceum seedlings from seeds previously subjected to different concentrations of the mutant agent diethyl sulfate (DES). The polymorphic loci ranged from 87.5 to 100%, number of effective alleles (Ne) between 1.0 and 1.99. The most polymorphic loci were observed in TG, AG, ACA, and CGA, which showed a mean unbiased heterosis between 0.34 and 0.51 with an average of 0.44, which allows establishing that these markers are useful to obtain greater discrimination between mutants in S. betaceum. Genetic distances ranged from 0.30 to 1.0. The 81.28% of these records were between 0.60 and 0.90. This reveals a low level of changes due to DES. These small changes contribute to enriching the genetic variability of the DES-treated sample. The RAMs markers were useful for detecting changes between plants from DES treated seeds and normal plants. Genetic variability between DES treatments was higher than non-DES treatments. Genetic similarities were low between treated and untreated plants and were high among untreated plants. The changes produced by DES were of low magnitude, however, they produced changes in the levels of genetic variability.
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The main objective of this study is to investigate the patterns of genetic diversity and phylogenetic relationships within populations of Detarium microcarpum (Fabaceae) relative to different spatial conditions. Seventy-eight (78) accessions of D. microcarpum belonging to six populations (Phytogeographic districts) were sampled. In order to have very good quality DNA for molecular analysis, an optimization of the DNA isolation protocol was made. The molecular analysis of the accessions was carried out using 7 chloroplast microsatellite markers. The polymorphism rate (P) is 85.71% and the Polymorphism Information Content (PIC) was in the range of 0.43 (Ntcp_9) to 0.73 (Ccmp_2) with an average of 0.59. Allelic richness (A) ranged from 1.41 to 2.85 with an average of 2.04. The observed heterozygosity (Ho) ranged from 0.23 to 0.60 with an average of 0.39. The expected heterozygosity (He) ranged from 0.43 to 0.60 with a mean of 0.50. Wright's fixation index (FIS) ranged from -0.17 to 0.47. The effective allele (Ae) is between 1.77 and 2.53 with an average of 2.02. Wright differentiation index (FST) was 0.024. Phylogenetic analysis revealed that the NST value was significantly higher than the GST value (NST = 0.452; GST = 0.190; p <0.05). A relatively low hd haplotype diversity is obtained (Hd = 0.320). AMOVA analysis showed that 17.35% of the variation existed within populations but 45.80% among populations within the species. Neighbor-Joining phylogenetic tree of D. microcarpum revealed three non-distinct clusters haplotypes showing the existence of gene flow between populations of the species. Our findings of genetic structure and gene flow of D. microcarpum populations based on different spatial conditions is caused by evolutionary forces such as scattering and pollination.
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Introducción. El cáncer colorrectal tiene una alta incidencia en la población mundial. Diversas vías moleculares están involucradas en su desarrollo, entre ellas, la inestabilidad cromosómica, la inestabilidad microsatelital y la epigenética. Objetivo. Hacer la caracterización molecular de 44 individuos con cáncer colorrectal esporádico. Materiales y métodos. El análisis de mutaciones en los genes APC, KRAS, TP53 y BRAF se hizo mediante secuenciación de Sanger; la inestabilidad microsatelital se determinó mediante electroforesis capilar utilizando cinco marcadores de repetición corta en tándem (Short Tandem Repeat) y el estado de metilación del promotor del gen MLH1 se hizo con la técnica MS-PCR (Methylation-Specific PCR). Resultados. La frecuencia de mutación de los genes APC, KRAS y TP53 fue del 18,1, 25 y 4,5 %, respectivamente; las mutaciones detectadas se localizaron con mayor frecuencia en el colon derecho. La frecuencia de inestabilidad microsatelital fue del 27,2 % y el 73,1 % en los tumores con metilación en el gen MHL1, y el 91,6 % de los tumores con inestabilidad microsatelital presentaba metilación en el gen MLH1. En el grupo de tumores con estabilidad microsatelital, las mutaciones en los genes APC, KRAS y TP53 fueron más frecuentes que en el grupo de tumores con inestabilidad microsatelital. La metilación del gen MLH1 fue la alteración más predominante. Conclusiones. En los pacientes con cáncer colorrectal evaluados se demostró la presencia de alteraciones moleculares en las diferentes vías genéticas, las cuales son comunes en su carcinogénesis. Los pacientes presentaron un perfil de mutaciones diferente al de otras poblaciones. Los hallazgos obtenidos en este estudio confirman la heterogeneidad molecular descrita en el desarrollo del cáncer colorrectal.
Introduction: Colorectal cancer has a high incidence in the world population. Different molecular pathways, such as chromosomal instability, microsatellite instability, and epigenetics are involved in its development. Objective: To perform molecular characterization in 44 individuals with sporadic colorectal cancer. Materials and methods: We conducted mutation analyses of the APC, KRAS, TP53 y BRAF genes using Sanger sequencing techniques; microsatellite instability was determined by capillary electrophoresis with five STR genetic markers while the methylation status of the MHL1 promotor gene was analyzed using methylation-specific PCR. Results: APC, KRAS, and TP53 genes mutation frequency was 18.1%, 25%, and 4.5%, respectively; the somatic mutations detected were located more frequently in the right colon. The frequency of microsatellite instability was 27.2% and 73.1% of the tumors had the MHL1 gene methylated while 91.6% of microsatellite instability-positive tumors had the methylated MLH1 gene. The mutation profile of microsatellite stability tumors APC, KRAS, and TP53 genes was more frequent than in the microsatellite instability-positive tumors. The methylation of the MLH1 gene was the most predominant molecular alteration. Conclusions: We identified molecular alterations in different genetic pathways of the colorectal cancer patients evaluated, which are common in the carcinogenesis of this cancer. These patients showed a different mutational profile compared to other populations. Our findings confirm the molecular heterogeneity described in the development of colorectal cancer.