Deregulation of apoptosis-related genes is associated with PRV1 overexpression and JAK2 V617F allele burden in Essential Thrombocythemia and Myelofibrosis

<p>Abstract</p> <p>Background</p> <p>Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF) are Chronic Myeloproliferative Neoplasms (MPN) characterized by clonal myeloproliferation/myeloaccumulation without cell maturation impairment. The JAK2 V617F mutation and <it>PRV1 </it>gene overexpression may contribute to MPN physiopathology. We hypothesized that deregulation of the apoptotic machinery may also play a role in the pathogenesis of ET and PMF. In this study we evaluated the apoptosis-related gene and protein expression of BCL2 family members in bone marrow CD34⁺hematopoietic stem cells (HSC) and peripheral blood leukocytes from ET and PMF patients. We also tested whether the gene expression results were correlated with JAK2 V617F allele burden percentage, <it>PRV1 </it>overexpression, and clinical and laboratory parameters.</p> <p>Results</p> <p>By real time PCR assay, we observed that <it>A1, MCL1, BIK and BID</it>, as well as <it>A1, BCLW </it>and <it>BAK </it>gene expression were increased in ET and PMF CD34⁺cells respectively, while pro-apoptotic <it>BAX </it>and anti-apoptotic <it>BCL2 </it>mRNA levels were found to be lower in ET and PMF CD34⁺cells respectively, in relation to controls. In patients' leukocytes, we detected an upregulation of anti-apoptotic genes <it>A1, BCL2, BCL-X_L</it>and <it>BCLW</it>. In contrast, pro-apoptotic <it>BID </it>and <it>BIM_EL</it>expression were downregulated in ET leukocytes. Increased BCL-X_Lprotein expression in PMF leukocytes and decreased BID protein expression in ET leukocytes were observed by Western Blot. In ET leukocytes, we found a correlation between JAK2 V617F allele burden and <it>BAX, BIK and BAD </it>gene expression and between <it>A1, BAX </it>and <it>BIK </it>and <it>PRV1 </it>gene expression. A negative correlation between <it>PRV1 </it>gene expression and platelet count was observed, as well as a positive correlation between <it>PRV1 </it>gene expression and splenomegaly.</p> <p>Conclusions</p> <p>Our results suggest the participation of intrinsic apoptosis pathway in the MPN physiopathology. In addition, <it>PRV1 </it>and JAK2 V617F allele burden were linked to deregulation of the apoptotic machinery.</p

Genetic profile analysis of tumor stem cells in locally advanced breast cancer

BackgroundBreast carcinoma is a highly prevalent and incident disease. About half the observed cases are diagnosed in later and/or disseminated disease stages. Treatment success in advanced disease stage occurs in about 20% of cases. The identification of patients who would most benefit from neoadjunvant therapy can reduce treatment costs and avoid adverse effects in patients with low probability of response. However, is not yet possible to make such a prediction. The cancer stem cells (CSCs) paradigm relates a cell population resistant to radiotherapy, chemotherapy and cells capable of tumor initiation and recurrence. The identification and characterization of CSCs in the primary tumor can be an effective method of predicting response to neoadjuvant chemotherapy in locally advanced breast cancer.Materials and methodsWe aim to include 40 patients diagnosed with invasive ductal carcinoma, who will undergo neoadjuvant chemotherapy before surgery. We are in process of collecting tumor tissue biopsies and quantifying, by flow cytometry, and separating, by FACS, the CSCs. We will define CSCs genetic profiles and correlate them with pathological response to the treatment. Biopsies have been collected from five patients to date; from these samples, CSCs were sorted and RNA was extracted and stored. We are following patients for their clinical progress.ResultsTo date, we did not observe statistical differences in the percentage of CSCs in these five samples. We expect to find transcriptional differences between CSCs in tumors from patients who respond to neoadjuvant chemotherapy and from patients who do not respond to treatment regimens.ConclusionsAlthough our preliminary data did not show differences, we expect a slightly different percentage of CSCs in tumor samples from responders vs. non-responders, in a larger sample set. However, CSCs transcriptome differences between the two groups of patients may yield a better understanding of neoadjuvant chemotherapy resistance, preventing unnecessary and costly treatment for many patients