Identification of a Proliferation Gene Cluster Associated with HPV E6/E7 Expression Level and Viral DNA Load in Invasive Cervical Carcinoma

Specific HPV DNA sequences are associated with more than 90% of invasive carcinomas of the uterine cervix. Viral E6 and E7 oncogenes are key mediators in cell transformation by disrupting TP53 and RB pathways. To investigate molecular mechanisms involved in the progression of invasive cervical carcinoma, we performed a gene expression study on cases selected according to viral and clinical parameters. Using Coupled Two-Way Clustering and Sorting Points Into Neighbourhoods methods, we identified a Cervical Cancer Proliferation Cluster composed of 163 highly correlated transcripts, many of which corresponded to E2F pathway genes controlling cell proliferation, whereas no primary TP53 targets were present in this cluster. The average expression level of the genes of this cluster was higher in tumours with an early relapse than in tumours with a favourable course (P=0.026). Moreover, we found that E6/E7 mRNA expression level was positively correlated with the expression level of the cluster genes and with viral DNA load. These findings suggest that HPV E6/E7 expression level plays a key role in the progression of invasive carcinoma of the uterine cervix via the deregulation of cellular genes controlling tumour cell proliferation. HPV expression level may thus correspond to a biological marker useful for prognosis assessment and specific therapy of the disease

Relationship of gene expression and chromosomal abnormalities in colorectal cancer. Cancer Res

Several studies have verified the existence of multiple chromosomal abnormalities in colon cancer. However, the relationships between DNA copy number and gene expression have not been adequately explored nor globally monitored during the progression of the disease. In this work, three types of array-generated data (expression, single nucleotide polymorphism, and comparative genomic hybridization) were collected from a large set of colon cancer patients at various stages of the disease. Probes were annotated to specific chromosomal locations and coordinated alterations in DNA copy number and transcription levels were revealed at specific positions. We show that across many large regions of the genome, changes in expression level are correlated with alterations in DNA content. Often, large chromosomal segments

Hemodynamic response imaging: a potential tool for the assessment of angiogenesis in brain tumors.

Blood oxygenation level dependence (BOLD) imaging under either hypercapnia or hyperoxia has been used to study neuronal activation and for assessment of various brain pathologies. We evaluated the benefit of a combined protocol of BOLD imaging during both hyperoxic and hypercapnic challenges (termed hemodynamic response imaging (HRI)). Nineteen healthy controls and seven patients with primary brain tumors were included: six with glioblastoma (two newly diagnosed and four with recurrent tumors) and one with atypical-meningioma. Maps of percent signal intensity changes (ΔS) during hyperoxia (carbogen; 95%O2+5%CO2) and hypercapnia (95%air+5%CO2) challenges and vascular reactivity mismatch maps (VRM; voxels that responded to carbogen with reduced/absent response to CO2) were calculated. VRM values were measured in white matter (WM) and gray matter (GM) areas of healthy subjects and used as threshold values in patients. Significantly higher response to carbogen was detected in healthy subjects, compared to hypercapnia, with a GM/WM ratio of 3.8 during both challenges. In patients with newly diagnosed/treatment-naive tumors (n = 3), increased response to carbogen was detected with substantially increased VRM response (compared to threshold values) within and around the tumors. In patients with recurrent tumors, reduced/absent response during both challenges was demonstrated. An additional finding in 2 of 4 patients with recurrent glioblastoma was a negative response during carbogen, distant from tumor location, which may indicate steal effect. In conclusion, the HRI method enables the assessment of blood vessel functionality and reactivity. Reference values from healthy subjects are presented and preliminary results demonstrate the potential of this method to complement perfusion imaging for the detection and follow up of angiogenesis in patients with brain tumors

Means and standard deviations of HRI values calculated from all healthy subjects.

<p>ΔS = percent signal intensity changes; GM = gray matter; WM = white matter; VRM = vascular reactivity mismatch.</p

HRI and rCBV values calculated at the lesion and contra lateral side VOIs.

<p>ΔS = percent signal intensity changes; rCBV = relative cerebral blood volume; CLS = contralateral side.</p>1<p>Vascular reactivity index, number of voxels (in percentages) above the defined VRM threshold.</p>2<p>Lesion crosses brain midline, thus contralateral side VOI could not be defined.</p>3<p>DSC perfusion was not performed.</p

Hemodynamic Response Imaging in the healthy brain.

<p>Representative HRI results obtained from a 29 year old healthy subject. (A) ΔS-O₂ map; (B) ΔS-CO₂ map; (C) the corresponding T₁-weighted (anatomical) image; (D) the gray and white matter masks (GM and WM, respectively); the mean time courses of the signal intensity change (%) during hyperoxic challenge (E) and hypecapnic (F) challenges, calculated from the GM VOI of this subject.</p

Patients' clinical information.

<p>y = years; M/F = male/female; RT = radiation therapy; Chemo = chemotherapy;</p

Negative

<p>Δ<b>S-O2 response.</b> Representative results obtained from a patient with recurrent GB (patient number 4), showing negative ΔS-O2 response during hyperoxic challenge observed distant from the tumor area. (A) ΔS-O₂ map; (B) T₁WI post contrast agent injection and (C) fluid attenuation inversion recovery (FLAIR) image. (D) The mean time courses of the signal intensity change (%) during hyperoxic challenge obtained from the area with negative response (VOI is marked by red rectangle on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049416#pone-0049416-g004" target="_blank">Figure 4A</a>).</p

Hemodynamic Response Imaging and pathological findings.

<p>Results obtained from a newly diagnosed patient with GB (patient number 2). Representative sagital (left), axial (center) and coronal (right) orientations taken through the tumor center of (A) T₁-weighted images; (B) ΔS-O₂ maps; (C) ΔS-CO₂ maps; (D) VRM maps (of the tumor area marked by white rectangle on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049416#pone-0049416-g003" target="_blank">figure 3B,C</a>) and (E) rCBV maps. The maps are superimposed on the anatomical images; color scales for all maps are located on the right side. Immunohistochemical staining of samples from the same tumor with: (F) Ki67 antibody for proliferation; (G) CD31 antibody for endothelial cells indicating vascularity and (H) SMA antibody for smooth muscle cells indicating vascular maturation.</p