Expression of the embryonic stem cell marker SOX2 in early-stage breast carcinoma

<p>Abstract</p> <p>Background</p> <p>The SRY-related HMG-box family of transcription factors member <it>SOX2 </it>has been mainly studied in embryonic stem cells as well as early foregut and neural development. More recently, SOX2 was shown to participate in reprogramming of adult somatic cells to a pluripotent stem cell state and implicated in tumorigenesis in various organs. In breast cancer, SOX2 expression was reported as a feature of basal-like tumors. In this study, we assessed SOX2 expression in 95 primary tumors of postmenopausal breast cancer patients.</p> <p>Methods</p> <p>Samples from 95 patients diagnosed and treated at the University of Tuebingen Institute of Pathology and Women's Hospital were analyzed by immunohistochemistry for SOX2 expression in the primary tumor samples and in corresponding lymph node metastasis, where present. Furthermore, SOX2 amplification status was assessed by FISH in representative samples. In addition, eighteen fresh frozen samples were analyzed for <it>SOX2</it>, <it>NANOG </it>and <it>OCT4 </it>gene expression by real-time PCR.</p> <p>Results</p> <p>SOX2 expression was detected in 28% of invasive breast carcinoma as well as in 44% of ductal carcinoma in situ (DCIS) lesions. A score of SOX2 expression (score 0 to 3) was defined in order to distinguish SOX2 negative (score 0) from SOX2 positive samples (score 1-3) and among latter the subgroup of SOX2 high expressors (score 3 > 50% positive cells). Overall, the incidence of SOX2 expression (score 1-3) was higher than previously reported in a cohort of lymph node negative patients (28% versus 16.7%). SOX2 expression was detected across different breast cancer subtypes and did not correlate with tumor grading. However, high SOX2 expression (score 3) was associated with larger tumor size (p = 0.047) and positive lymph node status (0.018). Corresponding metastatic lymph nodes showed higher SOX2 expression and were significantly more often SOX2 positive than primary tumors (p = 0.0432).</p> <p>Conclusions</p> <p>In this report, we show that the embryonic stem cell factor SOX2 is expressed in a variety of early stage postmenopausal breast carcinomas and metastatic lymph nodes. Our data suggest that SOX2 plays an early role in breast carcinogenesis and high expression may promote metastatic potential. Further studies are needed to explore whether SOX2 can predict metastatic potential at an early tumor stage.</p

ERG rearrangement in small cell prostatic and lung cancer

AIMS: Small cell prostatic cancer is a rare but aggressive disease. Currently, its histogenetic origin is unclear and its distinction from metastatic small cell lung cancer is challenging. The aim of our study was to determine whether the ERG rearrangement commonly observed in acinar prostatic cancer can distinguish small cell prostatic cancer from small cell lung cancer samples. METHODS AND RESULTS: We assessed 15 small cell prostatic cancers and 22 small cell lung cancers for ERG rearrangement using fluorescence in situ hybridization. Commonly used and novel immunohistochemical markers (i.e. androgen receptor, calcium activated nucleotidase 1, Golgi phosphoprotein 2, prostate-specific antigen, prostate-specific membrane antigen, CD56, epithelial membrane antigen, thyroid transcription factor 1, chromogranin A, synaptophysin and Ki67) were further studied. ERG rearrangement occurred in 86% of small cell prostatic cancers but in none of the small cell lung cancers and was the best marker to differentiate between both tumours (P < 0.0001). CONCLUSIONS: The ERG rearrangement is commonly observed in small cell prostatic cancer, supporting the hypothesis that ERG rearrangement occurs in aggressive prostatic cancers. Furthermore, the ERG rearrangement is the most significant marker to differentiate between small cell prostatic cancer and small cell lung cancer. Moreover, our data suggest that small cell prostatic cancer is not a tumour entity on its own, but a dedifferentiated variant of common acinar prostatic cancer

Frequency and clinicopathologic correlates of KRAS amplification in non-small cell lung carcinoma

KRAS amplification is a common molecular alteration in NSCLC, characterizing ∼15% of tumors. This alteration is associated with indicators of local aggressiveness, and may act synergistically with KRAS mutations to promote tumor progression

SOX2 amplification is a common event in squamous cell carcinomas of different organ sites

Acquired chromosomal aberrations, including gene copy number alterations, are involved in the development and progression of human malignancies. SOX2, a transcription factor-coding gene located at 3q26.33, is known to be recurrently and specifically amplified in squamous cell carcinomas of the lung, the esophagus, and the oral cavity. In these organs, the SOX2 protein plays an important role in tumorigenesis and tumor survival. The aim of this study was to determine whether SOX2 amplification is also found in squamous cell carcinomas in other organs commonly affected by this tumor entity. In addition, we examined a large spectrum of lung cancer entities with neuroendocrine differentiation (ie, small cell cancers, large cell cancers, typical and atypical carcinoids) for SOX2 and TTF1 copy number gains to reveal potential molecular ties to squamous cell carcinomas or adenocarcinomas of the lung. Applying fluorescence in situ hybridization, we assessed squamous cell carcinomas of the cervix uteri (n = 47), the skin (n = 57), and the penis (n = 53) for SOX2 copy number alterations and detected amplifications in 28%, 28%, and 32% of tumors, respectively. Furthermore, we performed immunohistochemical SOX2 staining and found that SOX2 amplification is significantly associated with overexpression of the corresponding protein in squamous cell carcinomas (P < .001). Of the lung cancer entities with neuroendocrine differentiation, only small cell cancers and large cell cancers exhibited SOX2 or TTF1 amplifications at significant frequencies, indicating that at least a subset of these might be dedifferentiated forms of squamous cell carcinomas or adenocarcinomas of the lung. We conclude that SOX2 amplification and consequent SOX2 protein overexpression may represent important mechanisms of tumor initiation and progression in a considerable subset of squamous cell carcinomas