Project description:In cervical cancer, an important mechanism by which tumour cells escape immune surveillance is loss of HLA class I, enabling tumours to evade recognition and lysis by cytotoxic T lymphocytes. Some tumours, however, escape from immune surveillance without accumulating defects in antigen presentation. We hypothesized that tumours with no or partial loss of HLA class I develop alternative mechanisms to prevent immune surveillance. To investigate this hypothesis, genome-wide expression profiling using Illumina arrays was performed on cervical squamous cell carcinomas showing overall loss of HLA class I, partial and normal HLA class I protein expression. Statistical analyses revealed no significant differences in gene expression between tumours with partial (n = 11) and normal HLA class I expression (n = 10). Comparison of tumours with normal/partial HLA class I expression (n = 21) with those with overall loss of HLA class I expression (n = 11) identified 150 differentially expressed genes. Most of these genes were involved in the defense response (n = 27), and, in particular, inflammatory and acute phase responses. Especially SerpinA1 and SerpinA3 were found to be upregulated in HLA positive tumours (3.6 and 8.2 fold, respectively), and this was confirmed by real-time PCR and immunohistochemistry. In a group of 117 tumours, high SerpinA1 and SerpinA3 expression in association with normal/partial HLA expression correlated significantly with poor overall survival (p = 0.035 and p = 0.05, respectively). This study shows that HLA positive tumours are characterized by a higher expression of genes associated with an inflammatory profile and that expression of the acute phase proteins SerpinA1 and SerpinA3 in HLA positive tumours is associated with worse prognosis. Keywords: Cell type comparison
Project description:Persistent infection by high-risk human papillomaviruses (HPVs) is associated with the development of cervical cancer and a subset of anogenital and head and neck squamous cell carcinomas. Abnormal expression of cellular microRNAs (miRNAs) plays an important role in the development of cancer, including HPV-related tumors. MiRNA expression profile was investigated by microrray analysis in the HPV-positive cervical cancer cell lines SiHa (HPV16-positive cell line derived from a cervical squamous cell carcinoma), CaSki (HPV16-positive cell line derived from a metastatic cervical epidermoid carcinoma), and HeLa (HPV18-positive cell line derived from a cervical adenocarcinoma) and compared with primary HFKs and C33a (HPV-negative cervical cell line).
Project description:<p>Cervical cancer is responsible for 10-15% of cancer related deaths in women worldwide. The etiological role of infection with high-risk human papilloma viruses (HPV) in carcinomas of the cervix is well established. In general, the development of cervical carcinomas follows a progression from persistent HPV infection through precancerous lesions to invasive cancer. Previous studies have implicated somatic mutations in PIK3CA, PTEN, TP53, STK11 and KRAS as well as chromosome-arm level copy number alterations in the pathogenesis of cervical carcinomas. Here, we report whole exome sequencing analysis of 118 cervical carcinoma-normal paired samples from patients in Norway and Mexico, as well as transcriptome sequencing of 80 cases and whole genome sequencing of 13 tumor-normal pairs. Novel somatic mutations include recurrent E322K substitutions in the MAPK1 gene encoding the ERK2 kinase and inactivating mutations in the HLA-B gene. In addition, recurrent somatic mutations in FBXW7, EP300, and NFE2L2 are novel in the context of primary cervical carcinomas. Analysis of HPV integration sites revealed recurrent integration into the RAD51B locus as well as co-occurrence of HPV genome integration and copy number gains within several genomic loci. These findings shed new light on the pathogenesis of cervical carcinomas and suggest potential novel therapeutic targets.</p>