Search

Background: Gastric cancer is the third leading cause of cancer-related death. Determining molecular and histopathologic tumor features, which may contribute to the development or progression of gastric cancer, can improve the prognosis. Expression patterns of DNA repair proteins such as MLH1, MSH2, MSH6, and PMS2 that are associated with microsatellite instability (MSI) are some of the markers that are useful in predicting the prognosis of gastric cancer. Purpose: The purpose was to determine the immunohistochemical expression pattern of MLH1, MSH2, MSH6, and PMS2 in tumor specimens of Iranian gastric carcinoma patients. Methods: In this prospective cohort, 186 consecutive patients with gastric cancer, attending Taleghani Hospital, were enrolled. The immunohistochemical expression patterns of MLH1, MSH2, MSH6, and PMS2 in tumor specimens among them were determined. Results: The results of this study demonstrated that 91.4% of our gastric cancer patients were negative for MSI, and 8.6% of them were MSI positive. The positive MSI was seen in 5.9% and 15.7% of male and female subjects, respectively, with a significant difference (P = 0.043). The other variables were not related to MSI results (P > 0.05). Conclusion: According to the obtained results, the expression of MLH1, MSH2, MSH6, and PMS2 in tumor specimens is positive in 8.6% of the total Iranian gastric cancer sample size, which is mainly positive in female subjects. However, it is not related to the location and stage of the tumor. [ABSTRACT FROM AUTHOR]

Objectives Despite numerous studies in order to determine the allele frequency and clinical impact of DNA methyltransferase 3 A (DNMT3A) gene mutations in acute myeloid leukemia (AML), reports about the expression analysis of this gene are rare and between the available, differences are evident. Methods In this study, we decided to investigate DNMT3A possible expression changes with regard to their mutation and cytogenetic status in a series of 96 AML patients. Results Mutations were founded in 17 of the 96 patients (17.7%) and associated with higher age and white blood cell count (P < 0.001). Our mutants have had shorter overall survival (OS) (P < 0.001) and relapse-free survival (RFS) (P = 0.011) than those without. Multivariate analysis showed that DNMT3A mutation is an independent prognostic indicator for OS and RFS (P < 0.001). In relation to expression results, we had over and under expression for our favorable and unfavorable cytogenetic subgroups, respectively (P = 0.005 and P < 0.001, respectively). In intermediate subgroup, total DNMT3A expression did not alter (P = 0.575). Interestingly, we noticed similar expression results for DNMT3A transcript 2, to that of the total. Discussion and conclusion In relation to DNMT3A expression, from the perspective of diagnostic application and its biological significance, it is difficult to accept its primacy over cytogenetic value in favorable and unfavorable subgroups and if so, we did not address this issue in our study due to sample size limitation. In intermediate subgroup, particularly in normal karyotype-AML, given the lack of convincing results, it seems unlikely that DNMT3A expression analysis could attract attention in diagnostic workup and risk prediction of AML. [ABSTRACT FROM AUTHOR]

Background: Breast cancer is a leading cause of morbidity and mortality in women worldwide. About 70 % of breast cancers are estrogen receptor (ER) positive. Blocking estrogen action by tamoxifen has been the treatment of choice in ER positive breast cancers for more than 30 years. In the past, several studies have revealed associations between gene copy number alterations and responsiveness to tamoxifen therapy, but so far no single gene copy number alteration could completely explain the response variation observed between individual breast cancer patients. Here, we set out to perform a simultaneous analysis of copy number alterations of several genes involved in the prognosis and response to therapy by multiplex ligation-dependent probe amplification (MLPA). Methods: A case-control study was designed encompassing 170 non-metastatic ER positive breast cancer patients (case group = 85, control group = 85). All patients in the control group had received standard adjuvant tamoxifen treatment for 5 years without any evidence of recurrence. Patients in the case group had experienced early recurrences while receiving tamoxifen treatment. 76 % of the patients of the case group and 73 % of the patients of the control group had received anthracycline-based adjuvant chemotherapy. Gene copy number alterations detected by MLPA in both groups were compared. Results: Amplification of CCND1 (OR = 3.13; 95 % CI = 1.35 to 7.26; p = 0.006) and TOP2A (OR = 3.05; 95 % CI = 1.13 to 8.24; p = 0.022) were significantly more prevalent in the case group, compared to the control group. In a multivariate analysis CCND1 ( p = 0.01) and TOP2A ( p = 0.041) amplifications remained significant predictors of recurrence. Conclusions: Our results indicate that CCND1 amplification may serve as a useful biomarker for hormone responsiveness, and that TOP2A amplification may serve as a useful prognostic biomarker. [ABSTRACT FROM AUTHOR]