Awatif Jamal

Microarray Expression Data Identify DCC as a Candidate Gene for Early Meningioma Progression.

Meningiomas are the most common primary brain tumors bearing in a minority of cases an aggressive phenotype. Although meningiomas are stratified according to their histology and clinical behavior, the underlying molecular genetics predicting aggressiveness are not thoroughly understood. We performed whole transcript expression profiling in 10 grade I and four grade II meningiomas, three of which invaded the brain. Microarray expression analysis identified deleted in colorectal cancer (DCC) as a differentially expressed gene (DEG) enabling us to cluster meningiomas into DCC low expression (3 grade I and 3 grade II tumors), DCC medium expression (2 grade I and 1 grade II tumors), and DCC high expression (5 grade I tumors) groups. Comparison between the DCC low expression and DCC high expression groups resulted in 416 DEGs (p-value < 0.05; fold change > 2). The most significantly downregulated genes in the DCC low expression group comprised DCC, phosphodiesterase 1C (PDE1C), calmodulin-dependent 70kDa olfactomedin 2 (OLFM2), glutathione S-transferase mu 5 (GSTM5), phosphotyrosine interaction domain containing 1 (PID1), sema domain, transmembrane domain (TM) and cytoplasmic domain, (semaphorin) 6D (SEMA6D), and indolethylamine N-methyltransferase (INMT). The most significantly upregulated genes comprised chromosome 5 open reading frame 63 (C5orf63), homeodomain interacting protein kinase 2 (HIPK2), and basic helix-loop-helix family, member e40 (BHLHE40). Biofunctional analysis identified as predicted top upstream regulators beta-estradiol, TGFB1, Tgf beta complex, LY294002, and dexamethasone and as predicted top regulator effectors NFkB, PIK3R1, and CREBBP. The microarray expression data served also for a comparison between meningiomas from female and male patients and for a comparison between brain invasive and non-invasive meningiomas resulting in a number of significant DEGs and related biofunctions. In conclusion, based on its expression levels, DCC may constitute a valid biomarker to identify those benign meningiomas at risk for progression.

Primary intracranial germ cell tumors

Background: Primary intracranial germ cell tumors are rare (ICGCTs) and usually localized in the pineal and suprasellar regions of the brain. They are divided into histologic types: Germinoma, teratoma choriocarcinoma, embryonal carcinoma, yolk sac tumor, and malignant mixed germ cell tumors (MMGCTs). Neuroimaging evaluation is useful to distinguish between the types of ICGCTs. Germinoma is highly sensitive to radiotherapy or/and chemotherapy, and is potentially curable without surgery. MMGCTs are treated with the combination of chemotherapy and radiation, with a poorer prognosis. ICGCTs warrant correct pre-operative diagnosis in order to decide on appropriate management. Aim: To report the clinicopathological and immunohistochemical findings in three cases of primary intracranial germ-cell tumor. Materials and Methods: Three cases of intracranial germ cell tumors inclusive of both genders and all brain regions were retrieved from the archives of the Anatomical Pathology Department at King Abdul Aziz University Hospital, Jeddah between the years, 1995-2011, through a computerized search. Results: Based on histological examination, they were respectively diagnosed as MMGCTs (two cases) and germinoma. Clinical, radiological, pathological characteristics and immunohistochemical profile of the three ICGCTs are presented along with the review of recent literature. Conclusion: ICGCTs are rare tumors affecting males more than females, and at the end of three years follow-up in the present study, treatment morbidity appears to be low with no recurrence observed among surviving patients, indicating that suprasellar and basal ganglia ICGCTs may have a favorable prognosis regardless of histological type. Pineal MMGCTs may have an aggressive course.

Pleomorphism and drug resistant cancer stem cells are characteristic of aggressive primary meningioma cell lines

BackgroundMeningioma tumors arise in arachnoid membranes, and are the most reported central nervous system (CNS) tumors worldwide. Up to 20% of grade I meningioma tumors reoccur and currently predictive cancer stem cells (CSCs) markers for aggressive and drug resistant meningiomas are scarce.MethodsMeningioma tissues and primary cell lines were investigated using whole transcriptome microarray analysis, immunofluorescence staining of CSCs markers (including CD133, Sox2, Nestin, and Frizzled 9), and drug treatment with cisplatin or etoposide.ResultsUnsupervised hierarchical clustering of six meningioma samples separated tissues into two groups. Analysis identified stem cells related pathways to be differential between the two groups and indicated the de-regulation of the stem cell associated genes Reelin (RELN), Calbindin 1 (CALB1) and Anterior Gradient 2 Homolog (AGR2). Immunofluorescence staining for four tissues confirmed stemness variation in situ. Biological characterization of fifteen meningioma primary cell lines concordantly separated cells into two functionally distinct sub-groups. Pleomorphic cell lines (NG type) grew significantly faster than monomorphic cell lines (G type), had a higher number of cells that express Ki67, and were able to migrate aggressively in vitro. In addition, NG type cell lines had a lower expression of nuclear Caspase-3, and had a significantly higher number of CSCs co-positive for CD133+ Sox2+ or AGR2+ BMI1+. Importantly, these cells were more tolerant to cisplatin and etoposide treatment, showed a lower level of nuclear Caspase-3 in treated cells and harbored drug resistant CSCs.ConclusionCollectively, analyses of tissues and primary cell lines revealed stem cell associated genes as potential targets for aggressive and drug resistant meningiomas.

The innovative safe fixative for histology, histopathology, and immunohistochemistry techniques: "pilot study using shellac alcoholic solution fixative".

The concerns over health and workplace hazards of formalin fixative, joined to its cross‐linking of molecular groups that results in suboptimal immunohistochemistry, led us to search for an innovative safe fixative. Shellac is a natural material which is used as a preservative in foods and pharmaceutical industries. This study was undertaken to evaluate the fixation adequacy and staining quality of histopathological specimens fixed in the “shellac alcoholic solution” (SAS), and also to determine the validity of immunohistochemical staining of SAS‐fixed material in comparison to those fixed in formalin. Fresh samples from 26 cases from various human tissues were collected at the frozen section room of King Abdulaziz University Hospital, and fixed in SAS fixative or in neutral buffered formaldehyde (NBF) for 12, 18, 24, and 48 h, and processed for paraffin sectioning. Deparaffinized sections were stained with hematoxylin and eosin (H&E) and immunostained for different antigens. The tissues fixed in SAS for >18 h showed best staining quality of H&E comparable to NBF‐fixed tissues. Comparison of the immunohistochemical staining of different tissues yielded nearly equivalent readings with good positive nuclear staining quality in both fixatives. These findings support the fixation and preservation adequacy of SAS. Furthermore, it was concluded that the good staining quality obtained with SAS‐fixed tissues, which was more or less comparable with the quality obtained with the formalin fixed tissues, supports the validity of this new solution as a good innovative fixative. Microsc. Res. Tech. 77:385–393, 2014.

Initial characterization of drug resistant cancer stem cells isolated from primary brain tumors (astrocytoma) cell lines generated from Saudi patients

Background The Cancer Stem Cells (CSCs) hypothesis proposes that malignant brain tumours are organized into aberrant cell hierarchies where a subset of parent CSCs replicate asymmetrically and unlimitedly to produce differentiated daughter cell [1,2]. These parent CSCs are highly adaptive and resistant to the chemotherapeutic drugs [3]. Developing new drugs that target CSCs requires a comprehensive understanding of the pharmacogenomics behavior of these cells [4,5]. Such understanding requires reliable in vitro and in vivo models that represent the beneficial patients. This project is set out to: i) Establish a collection of astrocytoma cell lines generated from Saudi patients, ii) Select drug resistant brain tumour CSCs, iii) Characterize drug resistant brain tumour CSCs individually, and iv) Deduce common features for drug resistant brain tumour CSCs.