Role of RT-PCR and FISH in diagnosis and monitoring of acute promyelocytic leukemia

Molecular biomarkers in acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. The pathophysiology of this disease is just beginning to be understood at the cellular and molecular level, and currently cytogenetic markers are the most important for risk stratification and treatment of AML patients. However, with the advent of new technologies, the detection of other molecular markers such as point mutations and characterization of epigenetic and proteomic profiles, have begun to play an important role in how the disease is approached. Recent evidence shows that the identification of new AML biomarkers contributes to a better understanding of the molecular basis of the disease, is significantly useful in screening, diagnosis, prognosis and monitoring of AML, as well as the possibility of predicting each individual's response to treatment. This review summarizes the most relevant molecular (genetic, epigenetic, and protein) biomarkers associated with acute myeloid leukemia and discusses their clinical importance in terms of risk prediction, diagnosis and prognosis.

Cytogenetic Profile of De Novo B lineage Acute Lymphoblastic Leukemia: Determination of Frequency, Distribution Pattern and Identification of Rare and Novel Chromosomal Aberrations in Indian Patients

BACKGROUND

Chromosomal aberrations identified in acute lymphoblastic leukemia (ALL) have an important role in disease diagnosis, prognosis and management. Information on karyotype and associated clinical parameters are essential to physicians for planning cancer control interventions in different geographical regions.

MATERIALS AND METHODS

In this study, we present the overall frequency and distribution patterns of chromosomal aberrations in both children and adult de novo B lineage ALL Indian patients using conventional cytogenetics, interphase FISH and multiplex RT-PCR.

RESULTS

Among the 215 subjects, cytogenetic results were achieved in 172 (80%) patients; normal karyotype represented 37.2% and abnormal 62.8% with a distribution as follows: 15.3% hypodiploidy; 10.3% hyperdiploidy; 15.8% t(9;22); 9.8% t(1;19); 3.7% t(12;21); 2.8% t(4;11); 2.8% complex karyotypes. Apart from these, we observed several novel, rare and common chromosomal rearrangements. Also, FISH studies using LSI extra-signal dual-color probes revealed additional structural or numerical changes.

CONCLUSIONS

These results demonstrate cytogenetic heterogeneity of ALL and confirm that the incidence of chromosomal abnormalities varies considerably. To the best of our knowledge, this is one of the largest reported series of cytogenetic investigations in Indian B-lineage ALL cases. In addition, ongoing cytogenetic studies are warranted in larger groups of B-lineage ALL cases to identify newly acquired chromosomal abnormalities that may contribute to disease diagnosis and management.

Expression of EBV encoded viral RNA 1, 2 and anti-inflammatory cytokine (interleukin-10) in FFPE lymphoma specimens: a preliminary study for diagnostic implication in Pakistan

Background

Epstein Barr Virus (EBV) plays a significant role as a cofactor in the process of tumorigenesis and has consistently been associated with a variety of malignancies. EBV encoded RNAs (EBER1 and EBER2) are the most abundant viral transcripts in latently EBV-infected cells and their role in viral infection is still unclear. Formalin Fixed Paraffin Embedded (FFPE) tissues of surgically removed carcinoma biopsies are widely available form but have never been exploited for expressional studies previously in Pakistan. Immunohistochemistry (IHC) and in situ hybridization (ISH) in FFPE biopsy tissues remains the gold standard for proving EBV relationship in a histopathological lesion but their reagents associated limitations confines their reliability in some applications. Recently introduced targeted drug delivery systems induce viral lytic gene expression and therefore require more sensitive method to quantify viral as well as cellular gene expression.

Methods

Eight (8) lymphoma samples were screened to detect the EBV genome. Qualitative and quantitative expression of EBV Encoded RNAs (EBER1, EBER2) and anti-inflammatory cytokine (interleukin-10) in FFPE EBV positive lymphoma tissue samples were then analysed by using Reverse transcriptase Polymerase Chain Reaction (RT-PCR) and Real Time Polymerase Chain Reaction (qRT-PCR), respectively.

Results

In this study we have successfully quantified elevated expressional levels of both cellular and viral transcripts, namely EBER1, EBER2 and anti-inflammatory cytokine (IL-10) in the FFPE Burkitt's lymphoma (BL) specimens of Pakistani origin.

Conclusions

These results indicate that FFPE samples may retain viral as well as cellular RNA expression information at detectable level. To our knowledge, this is first study which represents elevated expressional levels of EBER1, EBER2 and IL-10 in FFPE tissue samples of Burkitt's lymphoma in Pakistan. These observations will potentially improve current lacunas in clinical as well as diagnostic practices in Pakistan and can be further exploited to develop new strategies for studying cellular and/or viral gene expression.