Gain of chromosome 3q is an early and consistent genetic aberration in carcinomas of the vulva

SOX2 and squamous cancers

SOX2 is a pleiotropic nuclear transcription factor with major roles in stem cell biology and in development. Over the last 10 years SOX2 has also been implicated as a lineage-specific oncogene, notably in squamous carcinomas but also neurological tumours, particularly glioblastoma. Squamous carcinomas (SQCs) comprise a common group of malignancies for which there are no targeted therapeutic interventions. In this article we review the molecular epidemiological and laboratory evidence linking SOX2 with squamous carcinogenesis, explore in detail the multifaceted impact of SOX2 in SQC, describe areas of uncertainty and highlight areas for potential future research.

Genomic copy number analysis of a spectrum of blue nevi identifies recurrent aberrations of entire chromosomal arms in melanoma ex blue nevus

Blue nevi may display significant atypia or undergo malignant transformation. Morphologic diagnosis of this spectrum of lesions is notoriously difficult, and molecular tools are increasingly used to improve diagnostic accuracy. We studied copy number aberrations in a cohort of cellular blue nevi, atypical cellular blue nevi, and melanomas ex blue nevi using Affymetrix's OncoScan platform. Cases with sufficient DNA were analyzed for GNAQ, GNA11, and HRAS mutations. Copy number aberrations were detected in 0 of 5 (0%) cellular blue nevi, 3 of 12 (25%) atypical cellular blue nevi, and 6 of 9 (67%) melanomas ex blue nevi. None of the atypical cellular blue nevi displayed more than one aberration, whereas complex aberrations involving four or more regions were seen exclusively in melanomas ex blue nevi. Gains and losses of entire chromosomal arms were identified in four of five melanomas ex blue nevi with copy number aberrations. In particular, gains of 1q, 4p, 6p, and 8q, and losses of 1p and 4q were each found in at least two melanomas. Whole chromosome aberrations were also common, and represented the sole finding in one atypical cellular blue nevus. When seen in melanomas, however, whole chromosome aberrations were invariably accompanied by partial aberrations of other chromosomes. Three melanomas ex blue nevi harbored aberrations, which were absent or negligible in their precursor components, suggesting progression in tumor biology. Gene mutations involving GNAQ and GNA11 were each detected in two of eight melanomas ex blue nevi. In conclusion, copy number aberrations are more common and often complex in melanomas ex blue nevi compared with cellular and atypical cellular blue nevi. Identification of recurrent gains and losses of entire chromosomal arms in melanomas ex blue nevi suggests that development of new probes targeting these regions may improve detection and risk stratification of these lesions.

Gains of chromosome region 3q26 in intraepithelial neoplasia and invasive squamous cell carcinoma of the vulva are frequent and independent of HPV status

Aims:

Two different forms of vulvar intraepithelial neoplasia (VIN) are recognised: (1) usual-type (bowenoid) VIN, which is related to high-risk papillomavirus infection, and (2) differentiated (simplex) VIN, which is associated with chronic inflammation. The aim of this study was to investigate the presence of chromosome 3q26 gains in the spectrum of precancerous lesions and invasive squamous cell carcinomas (SCCs) of the vulva.

Methods:

3q26 gains were analysed using fluorescence in situ hybridisation in a series of usual-type VINs, VINs of the differentiated type and invasive squamous cell carcinomas. In addition, all cases were examined for human papillomavirus (HPV) DNA, p53 mutations, and p16 and p53 protein expression.

Results:

Gains of chromosome 3q26 were present in all VINs of the differentiated type and in 50% of the usual-type VIN lesions. 81% of SCCs were positive for 3q26 gains irrespective of the HPV status and of the associated precursor lesion. HPV-associated lesions exhibited the typical, strong cytoplasmic p16 accumulation while mutated p53 was only detected in HPV-negative VINs or SCCs, and was associated with an overexpression of p53 protein.

Conclusions:

Immunohistochemical evaluation of p16 and p53 expression aids in the differential diagnosis of squamous cell alterations of the vulva. However, detection of 3q26 imbalance is of additional diagnostic value in difficult cases of HPV-unrelated usual-type VINs and VINs of the differentiated type.