Detection of serum transforming growth factor-alpha in patients of primary epithelial ovarian cancers by enzyme immunoassay

The issues and challenges with cancer biomarkers

A biomarker is a measurable indicator used to distinguish precisely/objectively either normal biological state/pathological condition/response to a specific therapeutic intervention. The use of novel molecular biomarkers within evidence-based medicine may improve the diagnosis/treatment of disease, improve health outcomes, and reduce the disease's socio-economic impact. Presently cancer biomarkers are the backbone of therapy, with greater efficacy and better survival rates. Cancer biomarkers are extensively used to treat cancer and monitor the disease's progress, drug response, relapses, and drug resistance. The highest percent of all biomarkers explored are in the domain of cancer. Extensive research using various methods/tissues is carried out for identifying biomarkers for early detection, which has been mostly unsuccessful. The quantitative/qualitative detection of various biomarkers in different tissues should ideally be done in accordance with qualification rules laid down by the Early Detection Research Network (EDRN), Program for the Assessment of Clinical Cancer Tests (PACCT), and National Academy of Clinical Biochemistry. Many biomarkers are presently under investigation, but lacunae lie in the biomarker's sensitivity and specificity. An ideal biomarker should be quantifiable, reliable, of considerable high/low expression, correlate with the outcome progression, cost-effective, and consistent across gender and ethnic groups. Further, we also highlight that these biomarkers' application remains questionable in childhood malignancies due to the lack of reference values in the pediatric population. The development of a cancer biomarker stands very challenging due to its complexity and sensitivity/resistance to the therapy. In past decades, the cross-talks between molecular pathways have been targeted to study the nature of cancer. To generate sensitive and specific biomarkers representing the pathogenesis of specific cancer, predicting the treatment responses and outcomes would necessitate inclusion of multiple biomarkers.

How low can you go?

Extremely low numbers of active epidermal growth factor receptors are sufficient to drive tumor growth.

Human retinal transmitochondrial cybrids with J or H mtDNA haplogroups respond differently to ultraviolet radiation: implications for retinal diseases

Background

It has been recognized that cells do not respond equally to ultraviolet (UV) radiation but it is not clear whether this is due to genetic, biochemical or structural differences of the cells. We have a novel cybrid (cytoplasmic hybrids) model that allows us to analyze the contribution of mitochondrial DNA (mtDNA) to cellular response after exposure to sub-lethal dose of UV. mtDNA can be classified into haplogroups as defined by accumulations of specific single nucleotide polymorphisms (SNPs). Recent studies have shown that J haplogroup is high risk for age-related macular degeneration while the H haplogroup is protective. This study investigates gene expression responses in J cybrids versus H cybrids after exposure to sub-lethal doses of UV-radiation.

Methodology/Principal Findings

Cybrids were created by fusing platelets isolated from subjects with either H (n = 3) or J (n = 3) haplogroups with mitochondria-free (Rho⁰) ARPE-19 cells. The H and J cybrids were cultured for 24 hours, treated with 10 mJ of UV-radiation and cultured for an additional 120 hours. Untreated and treated cybrids were analyzed for growth rates and gene expression profiles. The UV-treated and untreated J cybrids had higher growth rates compared to H cybrids. Before treatment, J cybrids showed lower expression levels for CFH, CD55, IL-33, TGF-A, EFEMP-1, RARA, BCL2L13 and BBC3. At 120 hours after UV-treatment, the J cybrids had decreased CFH, RARA and BBC3 levels but increased CD55, IL-33 and EFEMP-1 compared to UV-treated H cybrids.

Conclusion/Significance

In cells with identical nuclei, the cellular response to sub-lethal UV-radiation is mediated in part by the mtDNA haplogroup. This supports the hypothesis that differences in growth rates and expression levels of complement, inflammation and apoptosis genes may result from population-specific, hereditary SNP variations in mtDNA. Therefore, when analyzing UV-induced damage in tissues, the mtDNA haplogroup background may be important to consider.

Significance of tyrosine kinase activity on malign transformation of ovarian tumors: a comparison between EGF-R and TGF-alpha

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are members of the polypeptide growth factor family. The epidermal growth factor-receptor (EGF-R) is a receptor tyrosine kinase of the ErbB family. Many types of cancer, including ovarian cancer, display enhanced EGF-R immunoreactivity on their cell surface membranes. Also, an increase in TGF-alpha synthesis and secretion usually occurs in human carcinoma cell lines. In this study, we compared the immunoreactivities of TGF-alpha and EGF-R in ovarian tumors and related immunohistochemical findings to the histological type of the tumors. Formalin-fixed, paraffin wax-embedded tissue sections from 40 patients who had serous-mucinous borderline tumor and serous-mucinous adenocarcinoma of the ovary (n=10 each) were stained with hematoxylin-eosin and labeled for binding of primary antibodies against TGF-alpha and EGF-R using an avidin-biotin-peroxidase method. A semi-quantitative grading system was used to compare immunohistochemical labeling intensities. Increased immunoreactivity of EGF-R and moderate immunoreactivity of TGF-alpha was detected in adenocarcinomas. There was no significant difference in the immunoreactivity of TGF-alpha among the histologic types of ovarian tumors. The results of this study support the hypothesis that EGF-R may be a more useful marker than TGF-alpha in epithelial ovarian tumors.

Alteration of the serum levels of the epidermal growth factor receptor and its ligands in patients with non-small cell lung cancer and head and neck carcinoma

Serum levels of the soluble epidermal growth factor receptor (sEGFR) and its ligands epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and amphiregulin (AR) were measured in healthy donors and patients with non-small cell lung cancer (NSCLC) and head and neck carcinoma (HNC). In NSCLC, we found sEGFR and EGF levels significantly lowered in patients with respect to healthy donors. In HNC patients, significantly diminished levels were found in the case of sEGFR, EGF and also AR. In both malignancies, no significant association was found between the serum levels of the molecules and the patients' gender, age or smoking habit. Only a significant association was found between the decrease of sEGFR and the absence of distant metastasis in NSCLC and the tumour stage in HNC. The most interesting result was that combining sEGFR and EGF, sensitivities of 88% in NSCLC and 100% in HNC were reached without losing specificity (97.8% in both cases). The use of discriminant analysis and logistic regression improved the sensitivity for NSCLC and the specificity for HNC. These data demonstrate a potentially interesting value of the serum levels of sEGFR and EGF, especially when combined, as markers for NSCLC and HNC.

A list of candidate cancer biomarkers for targeted proteomics

We have compiled from literature and other sources a list of 1261 proteins believed to be differentially expressed in human cancer. These proteins, only some of which have been detected in plasma to date, represent a population of candidate plasma biomarkers that could be useful in early cancer detection and monitoring given sufficiently sensitive specific assays. We have begun to prioritize these markers for future validation by frequency of literature citations, both total and as a function of time. The candidates include proteins involved in oncogenesis, angiogenesis, development, differentiation, proliferation, apoptosis, hematopoiesis, immune and hormonal responses, cell signaling, nucleotide function, hydrolysis, cellular homing, cell cycle and structure, the acute phase response and hormonal control. Many have been detected in studies of tissue or nuclear components; nevertheless we hypothesize that most if not all should be present in plasma at some level. Of the 1261 candidates only 9 have been approved as "tumor associated antigens" by the FDA. We propose that systematic collection and large-scale validation of candidate biomarkers would fill the gap currently existing between basic research and clinical use of advanced diagnostics.

Angiogenesis in gynecological oncology-mechanism of tumor progression and therapeutic targets

The purpose of this article is to review the current literature pertaining to various angiogenic stimulators and angiogenesis inhibitors in gynecological malignancies and the relevance of these markers in the prognosis of these diseases. We also summarize the antiangiogenic drugs currently in development and in clinical use in gynecological oncology. The information was obtained from a computer search of MEDLINE for studies published in the English language regarding angiogenesis and angiogenesis inhibitors in gynecological malignancies between 1970 and December 2003; additional sources were identified through cross-referencing. In ovarian cancer, various different angiogenic activators have been found to correlate with microvessed density (MVD), stage, lymph node and peritoneal metastasis, and survival. In cervical cancer, correlation has been seen between increased angiogenic markers and stage, grade, tumor size, and survival. Studies in endometriat cancer show correlation of angiogenic markers with stage, grade, MVD, and survival. Whereas, in gestational trophoblastic neoplasm (GTD) only few markers have been studied, and some correlated with progression. Information on anti angiogenic drugs currently in ongoing and upcoming trials in gynecological malignancies is also presented. Angiogenesis factors may have a prognostic role to play in patients with gynecological cancers and should continue to be investigated as clinically useful tumor markers. Antiangiogenic-targeted therapies offer an attractive strategy for clinical investigation in gynecologic oncology.

Ovarian surface epithelium: biology, endocrinology, and pathology

The epithelial ovarian carcinomas, which make up more than 85% of human ovarian cancer, arise in the ovarian surface epithelium (OSE). The etiology and early events in the progression of these carcinomas are among the least understood of all major human malignancies because there are no appropriate animal models, and because methods to culture OSE have become available only recently. The objective of this article is to review the cellular and molecular mechanisms that underlie the control of normal and neoplastic OSE cell growth, differentiation, and expression of indicators of neoplastic progression. We begin with a brief discussion of the development of OSE, from embryonic to the adult. The pathological and genetic changes of OSE during neoplastic progression are next summarized. The histological characteristics of OSE cells in culture are also described. Finally, the potential involvement of hormones, growth factors, and cytokines is discussed in terms of their contribution to our understanding of the physiology of normal OSE and ovarian cancer development.

Detection of transforming growth factor-alpha in the serum of gastric carcinoma patients

Transforming growth factor-alpha (TGF-alpha) is a ligand for epidermal growth factor receptor (EGFR) and it is overexpressed in various malignancies including lung, esophageal, colorectal, ovarian and gastric carcinomas. In patients with gastric carcinoma, its overexpression may be associated with advanced stage or poor prognosis. We have recently demonstrated that the mean serum level for EGFR in gastric carcinoma patients was significantly elevated compared with that of healthy controls. Using the enzyme-linked immunosorbent assay, the levels of TGF-alpha were determined in serum from 40 patients with gastric carcinoma (5 patients with stage I, 2 stage II, 4 stage III, and 29 stage IV patients) and 33 healthy controls. The mean serum level for TGF-alpha in the gastric carcinoma patients was significantly elevated as compared with that of healthy controls (104 +/- 235 vs. 22 +/- 16 pg/ml; p = 0.03). Eleven patients with gastric carcinoma (27.5%) showed elevated serum TGF-alpha levels above the cutoff value of 54 pg/ml (defined as 2 standard deviations above the mean of the control group). No significant association was noted between the positivity of TGF-alpha and clinicopathologic characteristics including gender, age and stage. However, poorly differentiated adenocarcinoma showed a higher positivity of serum TGF-alpha (43.8%) compared with other histologic types, which was marginally significant (p = 0.06). These results suggest that serum TGF-alpha could be useful as a tumor marker of gastric carcinoma for predicting prognosis and follow-up after surgery in patients whose initial serum TGF-alpha levels are elevated.