Jessica Wang-Rodriguez

ROR1 Is Expressed in Human Breast Cancer and Associated with Enhanced Tumor-Cell Growth

Receptor-tyrosine-kinase-like orphan receptor 1 (ROR1) is expressed during embryogenesis and by certain leukemias, but not by normal adult tissues. Here we show that the neoplastic cells of many human breast cancers express the ROR1 protein and high-level expression of ROR1 in breast adenocarcinoma was associated with aggressive disease. Silencing expression of ROR1 in human breast cancer cell lines found to express this protein impaired their growth in vitro and also in immune-deficient mice. We found that ROR1 could interact with casein kinase 1 epsilon (CK1ε) to activate phosphoinositide 3-kinase-mediated AKT phosphorylation and cAMP-response-element-binding protein (CREB), which was associated with enhanced tumor-cell growth. Wnt5a, a ligand of ROR1, could induce ROR1-dependent signaling and enhance cell growth. This study demonstrates that ROR1 is expressed in human breast cancers and has biological and clinical significance, indicating that it may be a potential target for breast cancer therapy.

Male breast carcinoma: correlation of ER, PR, Ki-67, Her2-Neu, and p53 with treatment and survival, a study of 65 cases.

Male breast cancer is rare, and experience of it in any single institution is limited. Our current understanding regarding its biology, natural history, and treatment strategies has been extrapolated from its female counterpart. The aim of this study is to evaluate the expression patterns of estrogen receptor (ER), progesterone receptor (PR), MiB1 (Ki67), Her-2/neu (c-erbB2), and p53 and to correlate them with the prognosis, presentation, staging, management, and survival/outcome in male breast carcinoma identified through the Veterans Administration nationwide cancer registry. Sixty-five cases of male breast cancer were reviewed for classification. Tumor blocks were requested from each institution for immunohistochemical staining and evaluation of ER, PR, p53, Her2-neu, and MiB1. Seventeen age- and disease-matched male veteran patients with breast gynecomastia were used as controls. Traditional prognostic data were collected for comparison with female breast cancers (i.e., age, lymph node status, clinical staging, tumor size, histological grade, and disease-free and overall survival). Male breast carcinoma had worse disease-free survival than controls (P = .03). The clinical stage regardless of tumor size or lymph node metastasis was the single most significant prognostic factor (P < .0001). ER-positive patients appeared to have a better survival than did ER-negative patients (P = .03, univariate; P not significant in multivariate) and did not benefit from treatment with tamoxifen (P = .0027, univariate; P = .42, multivariate). MiB1 and PR expressions did not correlate with treatment or survival, and p53 was associated with shorter disease free survival (P = .07, univariate; P = .047, multivariate). Stage for stage, Her2-neu was associated with shorter disease-free survival (P < .0001) and correlated with positive lymph nodes (P = .08). Surgery alone versus surgery with adjuvant treatments (chemotherapy, radiotherapy, tamoxifen, or combination) did not show any survival difference. Adjuvant therapy seemed to be associated with worse outcome. In the Veterans Administration hospital setting, the clinical stage and the expressions of p53 and Her2-neu in male breast carcinoma may be prognostically useful markers in guiding future treatment in prospective studies, whereas ER, PR, and MiB1 expressions are of limited value.

Expression of Protein Tyrosine Kinases in Head and Neck Squamous Cell Carcinomas

Protein tyrosine kinases (TKs) are overexpressed in many carcinomas and sarcomas. We studied the expression of the following TKs in head and neck squamous cell carcinoma (HNSCC): platelet-derived growth factor receptor (PDGFR), c-kit, epidermal growth factor receptor (EGFR), and a serine-threonine kinase, Akt. Formalin-fixed, paraffin-embedded tumor blocks from 44 consecutive patients with primary HNSCC and 5 specimens of benign pharyngeal and laryngeal mucosa were retrieved for immunohistochemical analysis. Of the specimens, 38 had enough material to stain for all 4 antibodies. The study included 21 pharyngeal (base of tongue, 14; tonsil, 6; soft palate, 1), 16 laryngeal, and 1 floor of the mouth carcinoma. All 4 kinases in the tumor samples were expressed highly (PDGFR, 95%-100%; EGFR, 38%-43%; c-kit, 50%-86%; p-Akt, 57%-81%), with EGFR, c-kit, and p-Akt significantly higher than in benign samples. None of the kinase expressions correlated with disease-free survival. The expression of the kinases raises the possibility of treatment of HNSCC by tyrosine and serine-threonine kinase inhibitors.

Profiling alternatively spliced mRNA isoforms for prostate cancer classification

BackgroundProstate cancer is one of the leading causes of cancer illness and death among men in the United States and world wide. There is an urgent need to discover good biomarkers for early clinical diagnosis and treatment. Previously, we developed an exon-junction microarray-based assay and profiled 1532 mRNA splice isoforms from 364 potential prostate cancer related genes in 38 prostate tissues. Here, we investigate the advantage of using splice isoforms, which couple transcriptional and splicing regulation, for cancer classification.ResultsAs many as 464 splice isoforms from more than 200 genes are differentially regulated in tumors at a false discovery rate (FDR) of 0.05. Remarkably, about 30% of genes have isoforms that are called significant but do not exhibit differential expression at the overall mRNA level. A support vector machine (SVM) classifier trained on 128 signature isoforms can correctly predict 92% of the cases, which outperforms the classifier using overall mRNA abundance by about 5%. It is also observed that the classification performance can be improved using multivariate variable selection methods, which take correlation among variables into account.ConclusionThese results demonstrate that profiling of splice isoforms is able to provide unique and important information which cannot be detected by conventional microarrays.

EGFR regulates the side population in head and neck squamous cell carcinoma.

Objective: To identify the presence of side population (SP) cells in established head and neck squamous carcinoma cell (HNSCC) lines and to determine the role of EGFR in the regulation of the side population of these cells.

The Onco-Embryonic Antigen ROR1 Is Expressed by a Variety of Human Cancers

ROR1 is an orphan-receptor tyrosine-kinase-like surface antigen that is expressed by many tissues during embryogenesis, some B-cell malignancies, and various cancer cell lines but not by virtually all normal adult tissues. Here, we report that large proportions of many different human cancers also express ROR1, particularly those cancers that have high-grade histology. Primary cancers that expressed ROR1 more commonly expressed high levels of phosphorylated AKT (p-AKT) and phosphorylated cAMP response element binding-factor (p-CREB) than similar cancers that lacked expression of ROR1. Induced expression of ROR1 could enhance basal p-AKT and p-CREB levels and could promote the growth of a cancer cell line, MEC1. Conversely, silencing ROR1 resulted in lower levels of p-AKT and p-CREB, which was associated with impaired tumor cell growth. In summary, this study found that many different human cancers express ROR1 and that ROR1 may play a functional role in promoting tumor cell growth, suggesting that this orphan-receptor tyrosine-kinase-like protein may be a potential target for therapy directed against a variety of human cancers.

The signaling adapter protein PINCH is up-regulated in the stroma of common cancers, notably at invasive edges†

PINCH is an LIM (double zinc finger domain) protein that functions as an adapter at a key convergence point for integrin and growth factor signal transduction. Because no information is available regarding its expression in vivo in human tissues, this study evaluated the distribution and abundance of PINCH in patients with breast, prostate, lung, colon, and skin carcinomas.

Electronic cigarettes induce DNA strand breaks and cell death independently of nicotine in cell lines

OBJECTIVES Evaluate the cytotoxicity and genotoxicity of short- and long-term e-cigarette vapor exposure on a panel of normal epithelial and head and neck squamous cell carcinoma (HNSCC) cell lines. MATERIALS AND METHODS HaCaT, UMSCC10B, and HN30 were treated with nicotine-containing and nicotine-free vapor extract from two popular e-cigarette brands for periods ranging from 48 h to 8 weeks. Cytotoxicity was assessed using Annexin V flow cytometric analysis, trypan blue exclusion, and clonogenic assays. Genotoxicity in the form of DNA strand breaks was quantified using the neutral comet assay and γ-H2AX immunostaining. RESULTS E-cigarette-exposed cells showed significantly reduced cell viability and clonogenic survival, along with increased rates of apoptosis and necrosis, regardless of e-cigarette vapor nicotine content. They also exhibited significantly increased comet tail length and accumulation of γ-H2AX foci, demonstrating increased DNA strand breaks. CONCLUSION E-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent. Further assessment of the potential carcinogenic effects of e-cigarette vapor is urgently needed.

EGFR Kinase Promotes Acquisition of Stem Cell-Like Properties: A Potential Therapeutic Target in Head and Neck Squamous Cell Carcinoma Stem Cells

Members of the EGFR/ErbB family of tyrosine kinases are found to be highly expressed and deregulated in many cancers, including head and neck squamous cell carcinoma (HNSCC). The ErbB family, including EGFR, has been demonstrated to play key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these characteristics have been linked to a small subpopulation of cells classified as cancer stem cells (CSCs) which are believed to be responsible for tumor initiation and maintenance. In this study, we investigated the possible role of EGFR as a regulator of “stemness” in HNSCC cells. Activation of EGFR by the addition of EGF ligand or ectopic expression of EGFR in two established HNSCC cell lines (UMSCC-22B and HN-1) resulted in the induction of CD44, BMI-1, Oct-4, NANOG, CXCR4, and SDF-1. Activation of EGFR also resulted in increased tumorsphere formation, a characteristic ability of cancer stem cells. Conversely, treatment with the EGFR kinase inhibitor, Gefinitib (Iressa), resulted in decreased expression of the aforementioned genes, and loss of tumorsphere-forming ability. Similar trends were observed in a 99.9% CD44 positive stem cell culture derived from a fresh HNSCC tumor, confirming our findings for the cell lines. Additionally, we found that these putative cancer stem cells, when treated with Gefitinib, possessed a lower capacity to invade and became more sensitive to cisplatin-induced death in vitro. These results suggest that EGFR plays critical roles in the survival, maintenance, and function of cancer stem cells. Drugs that target EGFR, perhaps administered in combination with conventional chemotherapy, might be an effective treatment for HNSCC.

Detection of chimerism and early engraftment after allogeneic peripheral blood stem cell or bone marrow transplantation by short tandem repeats

Chimerism can be monitored after HLA‐matched allogeneic bone marrow transplantation (BMT) or allogeneic peripheral blood stem cell transplantation (PBSCT) by detecting polymorphisms in short tandem repeats (STR). The purpose of our study was to document early complete chimerism in BMT and PBSCT recipients using STR, and to determine whether the initial WBC recovery correlated with the days required to attain complete chimerism. A total of 5 patients (2 PBSCT and 3 BMT) were followed by STR after transplantation. Peripheral blood obtained prior to transplantation was used to determine the 2 most informative STR probes for each donor/recipient pair. STR were amplified by polymerase chain reaction (PCR) with 8 commercial probes, and PCR products were visualized with silver staining. Peripheral blood was evaluated daily post‐transplantation for WBC counts and to identify the presence of mixed or full chimerism by STR. The sensitivity of the STR technique varied from 0.05 to 1%, depending on the probe. Full chimerism was documented between day 9 and 14 in PBSCT recipients and on day 14 and 16 in BMT recipients. The initial rise in WBC occurred within 3 days of the onset of full chimerism, indicating that full chimerism is a more sensitive indicator of early engraftment. Periodic recipient monitoring using STR after complete chimerism identifies those patients who revert to mixed chimeras. The STR method may be useful in future studies to determine the significance of early engraftment and the clinical implications of sustained complete chimerism or mixed chimerism.