Faculty Bibliography

The purpose of this study was to determine the role of long-chain fatty acyl-CoA synthetase 4 (ACSL4) in breast cancer. Public databases were utilized to analyze the relationship between ACSL4 mRNA expression and the presence of steroid hormone and human epidermal growth factor receptor 2 (HER2) in both breast cancer cell lines and tissue samples. In addition, cell lines were utilized to assess the consequences of either increased or decreased levels of ACSL4 expression. Proliferation, migration, anchorage-independent growth and apoptosis were used as biological end points. Effects on mRNA expression and signal transduction pathways were also monitored. A meta-analysis of public gene expression databases indicated that ACSL4 expression is positively correlated with a unique subtype of triple negative breast cancer (TNBC), characterized by the absence of androgen receptor (AR) and therefore referred to as quadruple negative breast cancer (QNBC). Results of experiments in breast cancer cell lines suggest that simultaneous expression of ACSL4 and a receptor is associated with hormone resistance. Forced expression of ACSL4 in ACSL4-negative, estrogen receptor alpha (ER)-positive MCF-7 cells resulted in increased growth, invasion and anchorage independent growth, as well as a loss of dependence on estrogen that was accompanied by a reduction in the levels of steroid hormone receptors. Sensitivity to tamoxifen, triacsin C and etoposide was also attenuated. Similarly, when HER2-positive, ACSL4-negative, SKBr3 breast cancer cells were induced to express ACSL4, the proliferation rate increased and the apoptotic effect of lapatinib was reduced. The growth stimulatory effect of ACSL4 expression was also observed in vivo in nude mice when MCF-7 control and ACSL4-expressing cells were utilized to induce tumors. Our data strongly suggest that ACSL4 can serve as both a biomarker for, and mediator of, an aggressive breast cancer phenotype.

The degree of differentiation in human cancers generally reflects the degree of malignancy, with the most undifferentiated cancer being also the highest grade and the most aggressive. High-grade serous ovarian cancers (HGSOC) are poorly differentiated and fast-growing malignancies. The molecular mechanisms underlying the poor differentiation of HGSOC has not been completely characterized. Evidence suggests that microRNAs (miRs) are dysregulated in HGSOC. Therefore, we focused on those miRs that are relevant to tumor differentiation. Expression profiling of miRs in HGSOC, indicated miR-106a and its family members were significantly upregulated. Upregulation of miR-106a was further validated by real-time RT-PCR and miR in situ hybridization in a large cohort of HGSOC specimens. Overexpression of miR-106a in benign and malignant ovarian cells significantly increased the cellular proliferation rate and expanded the side-population fraction. In particular, SKOV3 cells with miR-106a overexpression had significantly higher tumor initial/stem cell population (CD24 and CD133 positive cells) than control SKOV3 cells. Among many miR-106a predicated target genes, p130 (RBL2), an RB tumor suppressor family member, was not only confirmed as a specific target of miR-106a but also related to tumor growth and differentiation. The importance of mir-106a and RBL2 was further demonstrated in vivo, in which, SKOV3 cells overexpressing miR-106a formed poorly differentiated carcinomas and had reduced RBL2 levels. To our knowledge, this is the first study of miR-106a mediating proliferation and tumor differentiation in HGSOC. Implications: The current study suggests that the RB tumor suppressor pathway is a critical regulator of growth and differentiation in HGSOC.

The presence of glandular epithelium in urinary tract biopsies poses a diagnostic challenge. Intestinal metaplasia of the urethra may be seen in many congenital, iatrogenic, and reactive conditions, as well as in association with malignant conditions such as urethral adenocarcinoma. We present a case of a 61 year-old woman presenting with microscopic hematuria. Successive biopsies showed glandular epithelium with focal atypia in close association with inflammation, but no overt malignancy. Only on surgical resection was the associated high grade adenocarcinoma revealed. When intestinal-type mucosa is present within a urinary tract biopsy, associated malignancy may be present only focally. Thorough sampling and consideration of the differential diagnosis is imperative.

p44/MEP50/WDR77 has been identified as a coactivator of androgen receptor (AR), with distinct growth suppression and promotion function in gender specific endocrine organs and their malignancies. We dissected the functional domains of p44 for protein interaction with transcription factors, transcriptional activation, as well as the functional domains in p44 related to its growth inhibition in prostate cancer. Using a yeast two-hybrid screen, we identified a novel transcription complex AR-p44-Smad1, confirmed for physical interaction by co-immunoprecipitaion and functional interaction with luciferase assays in human prostate cancer cells. Yeast two-hybrid assay revealed that the N-terminal region of p44, instead of the traditional WD40 domain at the C-terminus, mediates the interaction among p44, N-terminus of AR and full length Smad1. Although both N and C terminal domains of p44 are necessary for maximum AR transcriptional activation, the N terminal fragment of p44 alone maintains the basic effect on AR transcriptional activation. Cell proliferation assays with N- and C- terminal deletion mutations indicated that the central portion of p44 is required for nuclear p44 mediated prostate cancer growth inhibition.

BACKGROUND: Androgen receptor (AR) expression in breast cancers may serve as a prognostic and predictive marker. We examined the expression pattern of AR and its phosphorylated forms, Ser-213 (AR-Ser[P]-213) and Ser-650 (AR-Ser[P]-650), in breast cancer and evaluated their association with clinicopathological parameters. METHODS: Immunohistochemistry was performed on primary and distant metastatic breast cancers and benign breast tissue using antibodies against AR, AR-Ser(P)-213, and AR-Ser(P)-650. The levels of cytoplasmic and nuclear expression were scored semiquantitatively using a histoscore. RESULTS: Nuclear staining of AR was observed in all benign breast tissue and 67% of cancer cases. Nuclear and cytoplasmic AR-Ser(P)-213 was increased in breast cancers 2-fold (P = .0014) and 1.7-fold (P = .05), respectively, compared with benign controls, whereas nuclear and cytoplasmic AR-Ser(P)-650 expression was decreased in tumors by 1.9-fold and 1.7-fold (both P < .0001), respectively. Increased expression of nuclear or cytoplasmic AR-Ser(P)-213 was observed in metastatic breast cancers (1.3-fold, P = .05), ER-negative (2.6-fold, P = .001), and invasive ductal carcinoma (6.8-fold, P = .04). AR-Ser(P)-650 expression was downregulated in lymph node-positive breast cancers (1.4-fold, P = .02) but was upregulated in invasive ductal carcinomas (3.2-fold, P < .0001) and metastases (1.5-fold, P = .003). Moreover, in ER-negative breast cancers, nuclear AR-Ser(P)-650 was decreased (1.4-fold, P = .005), and cytoplasmic AR-Ser(P)-650 was increased (1.4-fold, P = .003). CONCLUSIONS: AR and its phosphorylation at serines 213 and 650 are differentially expressed in breast cancer tumorigenesis and progression. Phosphorylation of AR at serines 213 and 650 is increased in ER-negative breast cancers, ductal carcinomas, and metastases and may have predictive value in breast cancer prognosis. Cancer 2013;000:000-000. (c) 2013 American Cancer Society.

AIM: To develop and validate a technique for construction of intermediate density tissue microarray (TMA) slides based on the transfer of tissue from pre-existing routine slides provided for pathology diagnosis with validation to show preservation of morphology and antigenicity of the transferred tissue. METHODS: A prostate cancer TMA was constructed using 20 cores from radical prostatectomy slides. This technique entails removal of the coverslip on each slide and reinforcement of the tissue by covering with Mount-Quick liquid mounting medium. The attached tissue with its new scaffold is 'biopsied' using a TMA needle (1.5 mm in diameter). The resultant biopsy disc is then transferred onto a recipient slide, with adhesion of the disc to the slide accomplished using heavy pressure. The preservation of morphology and antigenicity of this TMA is tested in comparison to a traditional TMA. RESULTS: After immunohistochemical staining, 35 of 39 cores (89.7%) on the patch TMA were intact compared with 39 of 40 cores (97.5%) on the traditional TMA (p>0.1). Expression patterns and density of the antigens (34betaE12, p63 and AMACR) on the patch TMA were almost identical to the traditional TMA. CONCLUSIONS: Patch TMA represents a viable alternative for tissue-based immunohistochemistry studies when paraffin blocks are unavailable. This may be a valuable tool for allowing the use of archival slide material for immunohistochemistry and enabling a standardised TMA platform to be used when the slides sent for review from other institutions are the only source of tissue available.

OBJECTIVE: To study the histopathology changes and clinical features of vesical diverticula, focusing on the neoplastic entities. MATERIALS AND METHODS: We retrieved data for 108 patients with vesical diverticula from the archives of our institute during the past 15 years (1998 to 2012) and reviewed their clinical and pathologic characteristics. RESULTS: Diverticula most often involved the lateral wall, followed by the posterolateral and posterior walls of the urinary bladder. Nonneoplastic processes were found in 70 of 108 patients (65%), including inflammation, metaplasia, and urothelial hyperplasia, with or without atypia/dysplasia. Primary carcinomas arising within the diverticula were found in 36 patients (33.3%), of which 33 were urothelial carcinoma, including 5 with divergent differentiation, 2 with squamous carcinoma, and 1 with adenocarcinoma. Patient follow-up for neoplastic diverticula (mean, 59 months; range, 1-108 months) showed that no patients died of disease progression. Concurrent or subsequent urothelial carcinoma was present in the nondiverticular bladder in 19 of 36 patients (53%). Four patients with subsequent extradiverticular urothelial carcinoma showed progression, with pathology upstaging. CONCLUSION: Inflammation, metaplasia, and dysplasia are commonly seen in vesical diverticula. In our series, which includes patients who underwent endoscopic or surgical intervention and microscopic examination, those with vesical diverticula appeared to have a significantly higher risk for development of urothelial carcinoma, which can occur synchronously or precede carcinoma of the nondiverticular bladder. Compared with their non-diverticulum-associated counterparts, a significantly higher percentage of diverticulum-associated bladder carcinomas are high-grade and invasive. Conservative approaches are suggested for tumors confined within diverticula, after extensive investigation of the nondiverticular bladder.

Mouse models of prostate cancer (PCa) are critical for understanding the biology of PCa initiation, progression, and treatment modalities. Here, we summarize recent advances in PCa mouse models that led to new insights into specific gene functions in PCa. For example, the study of transgenic mice with TMPRSS2/ERG, an androgen regulated fusion protein, revealed its role in developing PCa precursor lesions, prostate intraepithelial neoplasia (PIN) but not sufficient for PCa development. Double deficiency of Pten and Smad4 leads to a high incidence of metastatic PCa. Targeted deletion of Pten in castration-resistant Nkx3-1-expressing cells (CARNs) results in rapid carcinoma formation after androgen-mediated regeneration, indicating progenitor cells with luminal characteristics can play a role in initiation of PCa. Transgenic mice with activated oncogenes, growth factors, and steroid hormone receptors or inactivated tumor suppressors continue to provide insight for disease progression from initiation to metastasis. Further development of new PCa models with spatial and temporal regulation of candidate gene expression will likely enhance our understanding of the complex events that lead to PCa initiation and progression, thereby invoking novel strategies to combat this common disease in men.