BackgroundBreast cancer brain metastases (BCBM) develop in about 20–30% of breast cancer (BC) patients. BCBM are associated with dismal prognosis not at least due to lack of valuable molecular therapeutic targets. The aim of the study was to identify new molecular biomarkers and targets in BCBM by using complementary state-of-the-art techniques.MethodsWe compared array expression profiles of three BCBM with 16 non-brain metastatic BC and 16 primary brain tumors (prBT) using a false discovery rate (FDR) p < 0.05 and fold change (FC) > 2. Biofunctional analysis was conducted on the differentially expressed probe sets. High-density arrays were employed to detect copy number variations (CNVs) and whole exome sequencing (WES) with paired-end reads of 150 bp was utilized to detect gene mutations in the three BCBM.ResultsThe top 370 probe sets that were differentially expressed between BCBM and both BC and prBT were in the majority comparably overexpressed in BCBM and included, e.g. the coding genes BCL3, BNIP3, BNIP3P1, BRIP1, CASP14, CDC25A, DMBT1, IDH2, E2F1, MYCN, RAD51, RAD54L, and VDR. A number of small nucleolar RNAs (snoRNAs) were comparably overexpressed in BCBM and included SNORA1, SNORA2A, SNORA9, SNORA10, SNORA22, SNORA24, SNORA30, SNORA37, SNORA38, SNORA52, SNORA71A, SNORA71B, SNORA71C, SNORD13P2, SNORD15A, SNORD34, SNORD35A, SNORD41, SNORD53, and SCARNA22. The top canonical pathway was entitled, role of BRCA1 in DNA damage response. Network analysis revealed key nodes as Akt, ERK1/2, NFkB, and Ras in a predicted activation stage. Downregulated genes in a data set that was shared between BCBM and prBT comprised, e.g. BC cell line invasion markers JUN, MMP3, TFF1, and HAS2. Important cancer genes affected by CNVs included TP53, BRCA1, BRCA2, ERBB2, IDH1, and IDH2. WES detected numerous mutations, some of which affecting BC associated genes as CDH1, HEPACAM, and LOXHD1.ConclusionsUsing complementary molecular genetic techniques, this study identified shared and unshared molecular events in three highly aberrant BCBM emphasizing the challenge to detect new molecular biomarkers and targets with translational implications. Among new findings with the capacity to gain clinical relevance is the detection of overexpressed snoRNAs known to regulate some critical cellular functions as ribosome biogenesis.Electronic supplementary materialThe online version of this article (10.1186/s12967-017-1370-x) contains supplementary material, which is available to authorized users.

BCR/ABL fluorescent in situ hybridization study of chronic myeloid leukemia (CML) and Philadelphia ؉ (Ph ؉ ) acute lymphoid leukemia (ALL) indicated that approximately 9% of patients exhibited an atypical hybridization pattern consistent with a submicroscopic deletion of the 5 region of ABL and the 3 region of the BCR genes on the 9q ؉ chromosome. The CML patients with deletions had a shorter survival time and a high relapse rate following bone marrow transplant. Since deletions are associated with both Ph ؉ CML and ALL, it seemed probable that other leukemia-associated genomic rearrangements may also have submicroscopic deletions. This hypothesis was confirmed by the detection of deletions of the 3 regions of the CBFB and the MLL genes in AML M4 patients with inv(16) and in patients with ALL and AML associated with MLL gene translocations, respectively. In contrast, analysis of the AML M3 group of patients and AML M2 showed that similar large deletions were not frequently associated with the t(15; 17) or t(8;21) translocations. Analysis of sequence data from each of the breakpoint regions suggested that large submicroscopic deletions occur in regions with a high overall density of Alu sequence repeats. These findings are the first to show that the process of deletion formation is not disease specific in leukemia and also implicate that the presence of repetitive DNA in the vicinity of breakpoint regions may facilitate the generation of submicroscopic deletions. Such deletions could lead to the loss of one or more genes, and the associated haploinsufficiency may result in the observed differences in clinical behavior. IntroductionSince the discovery of the Philadelphia (Ph) chromosome in patients with chronic myelogenous leukemia (CML), it has become evident that specific chromosomal rearrangements are consistently associated with hematologic malignancies. 1 Although it is well established that such recurrent chromosome translocations generate several different types of pathognomic fusion oncogenes, the precise details of the molecular processes leading to these rearrangements in leukemias are poorly understood.The Ph chromosome arises from a reciprocal translocation of the long arms of chromosomes 9 and 22 that transposes the 3Ј segment of the ABL gene from 9q34 to the 5Ј segment of the BCR gene on 22q11. The resulting BCR-ABL gene is transcribed into a chimeric messenger RNA and then translated into fusion proteins of varying size (p190 bcr-abl , p210 bcr-abl , and p230 bcr-abl ), depending on the location of the breakpoint of the genes involved. Although these BCR/ABL chimeric fusion proteins play a central role in the pathogenesis of CML, it is unclear whether these fusion oncoproteins alone are sufficient to explain the full range of clinical responses to the disease process. 2 Recently it was proposed that extensive submicroscopic deletions, 5Ј of ABL and 3Ј of BCR, on the derivative chromosome 9 could often accompany BCR/ABL rearrangement and that the disease associated with a deletion was more refractil...

Mechanisms underlying prostate cancer (CaP) initiation and progression are poorly understood. A chromosomal instability mechanism leading to the generation of numerical and structural chromosomal changes has been implicated in the preneoplastic and neoplastic stages of CaP. Telomere dysfunction is one potential mechanism associated with the onset of such instability. To determine whether there was alteration in telomere length and chromosome number, 15 paraffin-embedded prostatectomy specimens were investigated using quantitative peptide nucleic acid (PNA) FISH analysis of representative foci of carcinoma, putative precancerous lesions (high-grade prostatic intraepithelial neoplasia, HPIN) and nondysplastic prostate epithelium. A significant decrease in telomere length was shown in both HPIN and CaP in comparison with normal epithelium. In addition, elevated rates of aneusomy suggested that increased levels of chromosomal aberrations were associated with decreased telomere length. Moreover, multiple foci of HPIN were shown to have a heterogeneous overall reduction of telomere length. This reduction was more evident in the histologic regions of the prostate containing CaP. Such observations lend support to the hypothesis that telomere erosion may be a consistent feature of CaP oncogenesis and may also be associated with the generation of chromosomal instability that characterizes this malignancy.

BackgroundHer2/neu is an oncogene that plays an important role in the pathogenesis of many cancer types. In bladder carcinoma (BC), the clinical significance of Her2/neu status remains under-investigated and poorly linked to the patients’ clinic-pathological features and survival status. Thus, the current study was conducted to assess Her2/neu status in a cohort of patients’ in Saudi Arabia, and to explore its prognostic value in BC.MethodsA total of 160 consent patients of transitional cell carcinoma (TCC) of bladder were arranged on a tissue microarray (TMA) and stained by immunohistochemistry (IHC) and bright-field dual in situ hybridization (BDISH) methods. The intensity of Her2/neu protein receptor immunostaining was evaluated, correlated to Her2/neu gene amplification status in TCC and assessed for potential clinical value by correlation measures.ResultsIHC data demonstrated that Her2/neu protein is expressed in 60 % (2+ and 3+) of our TCC patient’s cohort from Saudi Arabia. Her2/neu gene amplification is detected in 25 % by BDISH. There was a strong association between Her2/neu protein levels and lymph node invasion (p = 0.04), tumor stage (p = 0.002), vascular invasion and borderline significance with distant metastasis (p = 0.07). Amplification of Her2/neu gene was associated with tumor grade (p = 0.03) and poor disease-specific survival (p = 0.02), in that, patients with non-amplified Her2/neu gene live longer. Interestingly, there was a reasonable concordance rate (71 %) between IHC and BDISH data in the analyzed cohort.ConclusionThe study showed that 25 % of our patients’ cohort has Her2/neu over-expression. This Her2/neu (over-expression/amplification) status was concordant using either IHC or BDISH and significantly associated with disease aggressiveness and poor outcome. These findings suggested a potential impact of anti-Her2 targeted therapy in the treatment of bladder cancer with amplified/overexpressed HER2 that needs further investigation.

BackgroundIncreased mesenchymal–epithelial transition factor gene (c-MET) expression in several human malignancies is related to increased tumour progression. The aim of the present study is to explore the relationship between immunohistochemical expression of c-MET in colorectal carcinoma (CRC) and the clinicopathological characteristics and follow up data, to compare the expression of c-MET in primary CRC and its metastasis in lymph nodes and to test its validity as independent prognostic factor.MethodsHundred and thirty-five archival CRC and nodal metastases samples were collected from King Abdulaziz University Hospital, Saudi Arabia. Tissue microarrays were constructed and immunohistochemistry was done to detected c-MET protein expression. Appropriate statistical analysis was performed.ResultsHigh c-MET immunostaining was significantly associated with tumour size larger than 5 cm (p < 0.003) and in left colon subsite (p < 0.05). There was no significant correlation between c-MET protein expression and age, sex, degree of differentiation, tumour invasion, presence of nodal metastasis, lymphovascular invasion, status of surgical resection margin, or presence of distant metastasis. Furthermore, no association between c-MET protein expression and disease free survival. High protein expression of c-MET is associated with the incidence of local disease recurrence (p < 0.012).Conclusionc-MET is a new promising target that may help in understanding the pathogenesis of CRC, and to be used as independent prognostic biomarker to predict local disease recurrence in CRC. Further molecular in vitro and in vivo studies are required to pursue c-MET as potential molecular marker of metastases and test the possibility of its incorporation as a new targeted therapeutic target.

BackgroundThe molecular etiology of thyroid carcinoma (TC) and other thyroid diseases which may present malignant precursor lesions is not fully explored yet. The purpose of this study was to estimate frequency, type and clinicopathological value of BRAF exon 15 mutations in different types of cancerous and non-cancerous thyroid lesions originating in an ethnically diverse population.MethodsBRAF exon 15 was sequenced in 381 cases of thyroid lesions including Hashimoto´s thyroiditis, nodular goiters, hyperplastic nodules, follicular adenomas (FA), papillary TC (PTC), follicular variant PTC (FVPTC), microcarcinomas of PTC (micro PTC; tumor size ≤ 1 cm), follicular TC (FTC), and non-well differentiated TC (non-WDTC).ResultsWe identified BRAF mutations in one of 69 FA, 72 of 115 (63%) PTC, seven of 42 (17%) FVPTC, 10 of 56 (18%) micro PTC, one of 17 (6%) FTC, and one of eight (13%) non-WDTC. Most of the cases showed the common V600E mutation. One case each of PTC, FVPTC, and FTC harbored a K601E mutation. A novel BRAF mutation was identified in a FA leading to deletion of threonine at codon 599 (p.T599del). A rare 3-base pair insertion was detected in a stage III PTC resulting in duplication of threonine at codon 599 (p.T599dup). Patients with PTC harboring no BRAF mutation (BRAFwt) were on average younger than those with a BRAF mutation (BRAFmut) in the PTC (36.6 years vs. 43.8 years). Older age (≥ 45 years) in patients with PTC was significantly associated with tumor size ≥ 4 cm (P = 0.018), vessel invasion (P = 0.004), and distant metastasis (P = 0.001). Lymph node (LN) involvement in PTC significantly correlated with tumor size (P = 0.044), and vessel invasion (P = 0.013). Of notice, taken the whole TC group, family history of thyroid disease positively correlated with capsular invasion (P = 0.025).ConclusionsOlder age is manifold associated with unfavorable tumor markers in our series. The K601E identified in a PTC, FVPTC, and FTC seems to be more distributed among different histological types of TC than previously thought. The T599del is a yet undescribed mutation and the rare T599dup has not been reported as a mutation in PTC so far.

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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12935-017-0441-7) contains supplementary material, which is available to authorized users.

BackgroundColorectal cancer (CRC) is a heterogeneous disease with different molecular characteristics associated with many variables such as the sites from which the tumors originate or the presence or absence of chromosomal instability. Identification of such variables, particularly mutational hotspots, often carries a significant diagnostic and/or prognostic value that could ultimately affect the therapeutic outcome.MethodsHigh-throughput mutational analysis of 99 CRC formalin-fixed and paraffin-embedded (FFPE) cases was performed using the Cancer Hotspots Panel (CHP) v2 on the Ion Torrent™ platform. Correlation with survival and other Clinicopathological parameters was performed using Fisher’s exact test and Kaplan–Meier curve analysis.ResultsTargeted sequencing lead to the identification of frequent mutations in TP53 (65 %), APC (36 %), KRAS (35 %), PIK3CA (19 %), PTEN (13 %), EGFR (11 %), SMAD4 (11 %), and FBXW7 (7 %). Other genes harbored mutations at lower frequency. EGFR mutations were relatively frequent and significantly associated with young age of onset (p = 0.028). Additionally, EGFR or PIK3CA mutations were a marker for poor disease-specific survival in our cohort (p = 0.009 and p = 0.032, respectively). Interestingly, KRAS or PIK3CA mutations were significantly associated with poor disease-specific survival in cases with wild-type TP53 (p = 0.001 and p = 0.02, respectively).ConclusionsFrequent EGFR mutations in this cohort as well as the differential prognostic potential of KRAS and PIK3CA in the presence or absence of detectable TP53 mutations may serve as novel prognostic tools for CRC in patients from the Kingdom of Saudi Arabia. Such findings could help in the clinical decision-making regarding therapeutic intervention for individual patients and provide better diagnosis or prognosis in this locality.