ABSTRACT
BACKGROUND: Acute myeloid leukemia (AML) results from sequential genetic alterations in a normal hematopoietic stem cell or its progenitors giving rise to an autonomous clone that dominates the bone marrow leading to marrow failure. MicroRNAs are short non-coding nucleic acid sequences that regulate post-transcriptional gene expression by base-pairing with their target mRNAs. MiRNAs can be secreted into extracellular fluids and carried to target cells by vesicles or bound to proteins. Intracellular and circulating miRNAs are believed to be useful markers in the diagnosis, prognosis, and treatment of various cancers. Practically, circulating miRNAs are more stable at room temperatures and extreme conditions. PURPOSE: This study aimed to compare the expression of miR-126-3p and miR-423-5p in patients and normal subjects and correlate their expression with response to induction therapy and with their 2-year overall survival rate. PATIENTS AND METHODS: Circulating miR-126-3p and miR-423-5p was measured in the plasma of 43 adult AML patients and 35 age- and sex-matched controls by quantitative reverse transcriptase PCR. The fold change in differential expression for each gene was calculated using the comparative cycle threshold method. RESULTS: There was an increase in the expression of the studied miRNAs in patients compared to the control group. The average expression fold change of miR-126-3p was 3.02 (p= 0.010). The average expression fold change of miR-423-5p was 4.09 (p= 0.003). No significant correlation was found between the expression of miR-126-3p and miR-423-5p in the studied AML patients (r = 0.094, p = 0.22). Furthermore, no relationship was found between the expression of the studied miRNAs and response to induction therapy or the 2-year survival rate. CONCLUSION: Although further studies are needed, our findings highlight the studied circulating miRNAs as possible diagnostic markers for AML.
ABSTRACT
BACKGROUND: The human epidermal growth factor receptor 2(HER2) proto-oncogene is overexpressed or amplified in approximately 15%-25% of invasive breast cancers. Approximately 35% of HER2-amplified breast cancers have coamplification of the topoisomerase II-alpha (TOP2A) gene encoding an enzyme that is a major target of anthracyclines. Hence, the determination of genetic alteration (amplification or deletion) of both genes is considered as an important predictive factor that determines the response of breast cancer patients to treatment. The aims of this study are to determinate TOP2A status gene amplification in a set of Iraqi patients with breast cancer that have had an equivocal (2+) and positive HER2/neu by immunohistochemistry (IHC) and to compare the results with estrogen receptor (ER) and progesterone receptor (PR) and HER2/neu status. PATIENTS AND METHODS: A cross-sectional prospective study done on 53 patients with invasive breast carcinoma. Twenty-six out of total 53 cases were positive HER2/neu (3+), the remaining 27 equivocal HER2-IHC (2+) cases reanalyzed using dual-color chromogenic in situ hybridization (ZytoVision) probe kit for further identification of HER2/neu gene amplification. Using chromogenic in situ hybridization (CISH), TOP2A gene status determination was done for all cases. RESULTS: There is a direct significant correlation between TOP2A gene amplification and HER2/neu positivity, P < 0.05 in that 15 (39.4%) out of 38 positive HER2/neu cases were associated with topoisomerase gene amplification. Regarding relation of topoisomerase gene to hormone receptor status (ER and PR), there was a significant negative relationship between the gene and ER receptor status. The higher level of gene amplification was noticed in ER and PR negative cases in about 13 (43.3%) and 14 (48.2%) for ER and PR, respectively. CONCLUSION: TOP2A gene status has a significantly positive correlation with HER2/neu status while it has a significantly negative correlation with hormone receptor status.
