Patients with biallelic truncating mutations in PALB2 have a severe form of Fanconi anaemia (FA-N), with a predisposition for developing embryonal-type tumours in infancy. Here we describe two unusual patients from a single family, carrying biallelic PALB2 mutations, one truncating, c.1676_1677delAAinsG;(p.Gln559ArgfsTer2), and the second, c.2586+1G>A; p.Thr839_Lys862del resulting in an in frame skip of exon 6 (24 amino acids). Strikingly, the affected individuals did not exhibit the severe developmental defects typical of FA-N patients and initially presented with B cell non-Hodgkin lymphoma. The expressed p.Thr839_Lys862del mutant PALB2 protein retained the ability to interact with BRCA2, previously unreported in FA-N patients. There was also a large increased chromosomal radiosensitivity following irradiation in G2 and increased sensitivity to mitomycin C. Although patient cells were unable to form Rad51 foci following exposure to either DNA damaging agent, U2OS cells, in which the mutant PALB2 with in frame skip of exon 6 was induced, did show recruitment of Rad51 to foci following damage. We conclude that a very mild form of FA-N exists arising from a hypomorphic PALB2 allele.

The androgen receptor (AR) remains a key driver of prostate cancer (PCa) progression, even in the advanced castrate-resistant stage, where testicular androgens are absent. It is therefore of critical importance to understand the molecular mechanisms governing its activity and regulation during prostate tumourigenesis. MicroRNAs (miRs) are small ∼22 nt non-coding RNAs that regulate target gene, often through association with 3′ untranslated regions (3′UTRs) of transcripts. They display dysregulation during cancer progression, can function as oncogenes or tumour suppressors, and are increasingly recognised as targets or regulators of hormonal action. Thus, understanding factors which modulate miRs synthesis is essential. There is increasing evidence for complex and dynamic bi-directional cross-talk between the multi-step miR biogenesis cascade and the AR signalling axis in PCa. This review summarises the wealth of mechanisms by which miRs are regulated by AR, and conversely, how miRs impact AR's transcriptional activity, including that of AR splice variants. In addition, we assess the implications of the convergence of these pathways on the clinical employment of miRs as PCa biomarkers and therapeutic targets.

High-grade serous ovarian cancer (HGSOC) feature widespread genomic rearrangements that alter the copy number of genes. Genes for which elevated expression is detrimental to growth may be passengers in rearrangements that increase the copy number of strongly selective driver genes.There would then be selection pressure for compensatory epigenetic silencing of such passenger genes, such as through promoter DNA methylation.We have used two independent cohorts of primary HGSOC tumour samples to provide evidence of consistent dosage-compensating promoter methylation (DCPM) genome-wide. Mapping CpG methylation to genomic copy number, we show that bias due to variable tumour cellularity of tissue samples results in false positive associations between methylation and copy number.Adjusting for this bias, we found that approximately 5-10% of all measured promoter CpGs with copy number gain showed a statistically significant increase in methylation. DCPM nullifies the association between increased copy number and increased gene expression. We confirmed a functional basis for selective pressure against over-expressing two candidate passenger genes in the 3q12 locus, as overexpressing either gene reduced spheroid formation efficiency in two HGSOC cell lines. DCPM represents a novel class of specific functional interactions between genetic and epigenetic landscapes of cancers.