PTEN mutation, loss of heterozygosity, promoter methylation and expression in colorectal carcinoma: two hits on the gene?

The phosphatase and tensin homologue (PTEN) gene is considered to be a tumour-suppressor gene in various types of cancer, colorectal carcinoma among them. According to the 'two-hit' tumour-suppressor gene concept, inactivation occurs by any combination of the following three pathogenetic processes: mutation, loss of one allele [i.e.

Autoimmune pancreatitis in MRL/Mp mice is a T cell-mediated disease responsive to cyclosporine A and rapamycin treatment.

Background: Autoimmune pancreatitis (AIP) in humans invariably responds to steroid treatment, but little is known about the underlying pathogenesis and the benefits of alternative treatments.

Objective: To study the pathogenesis, and the efficacy of alternative immunosuppressant agents in the MRL/Mp mouse model of AIP.

Design: MRL/Mp mice were pretreated for 4 weeks with polyinosinic:polycytidylic acid to induce AIP.

Single nucleotide polymorphism array analysis of microsatellite-stable, diploid/near-diploid colorectal carcinomas without the CpG island methylator phenotype.

Colorectal carcinomas are considered to progress by chromosomal instability (CIN), or microsatellite instability (MSI) and/or epigenetic gene silencing; however, in previous studies we observed a small fraction of tumours without this molecular phenotype. To further investigate these 'X-type' tumours, neoplastic glands from five tumours were isolated by laser-capture microdissection and used for single nucleotide polymorphism (SNP) array analyses. DNA from our own low-passage primary colorectal carcinoma cell lines (n=9) was used for comparison.