Diagnostic Assays : Cancer


Biomarkers for Detecting Prostate Cancer

UW–Madison researchers have identified eight genetic markers, or biomarkers, for prostate cancer. They can be detected in histologically normal prostate samples and/or the bodily fluids of men with no history of prostate cancer.

The biomarkers act as red flags, exhibiting abnormal methylation levels when cancer is present in peripheral prostate tissue (this is called cancer ‘field defect’). These changes are believed to represent early stages of the cancer process.

The biomarkers are associated with the genes CAV1, EVX1, MCF2L, FGF1, WNT2, NCR2, EXT1 and SPAG4.

Detecting Ovarian Cancer and Risk

A UW–Madison researcher and others have developed a new ovarian cancer screening method that measures total or ionized serum calcium levels in blood samples. Women exhibiting elevated levels may be up to three times more likely to be diagnosed with ovarian cancer.

Serum calcium can be detected and quantified using standard techniques, including absorption spectrometry, ion selective electrode, fluorescent detection, etc. The measured levels can be incorporated into an overall risk score, identifying women who should undergo further CA125 and ultrasound screening.

Circulating Tumor Cell Assay Using Simple Blood Draw

The researchers now have developed the first fully integrated CTC assay that could eliminate the need for painful biopsies. The device leverages verIFAST technology to capture, purify and molecularly analyze CTCs from a single blood sample.

The sample is deposited in a first well and then magnetically drawn through a second well containing an isolation buffer like oil or wax. The increasingly purified cells are drawn into a final well for extraction or further treatment.

The device includes new technical features and is combined with downstream techniques for staining rare cells like CTCs.

Muc16 Bound to Immune Cells Provides an Improved Indicator for Ovarian Cancer and Preeclampsia

UW-Madison researchers now have discovered a new prognostic and diagnostic indicator for ovarian cancer and preeclampsia.   CA125 is a peptide epitope from a large glycosylated protein called Mucin 16 (Muc16).  The researchers found that levels of Muc16 bound to immune cells provide a more specific indicator of ovarian cancer regression or recurrence.  Because Muc16 binds to specific subsets of immune cells that express Siglec-9, measuring the amount of Siglec-9 expressed on the immune cells also provides a method of detecting ovarian cancer. 

In addition, Muc16 and Siglec-9 may serve as indicators of preeclampsia in pregnant women.  They can be used to detect preeclampsia and to distinguish women with ovarian cancer from healthy pregnant women and women with preeclampsia.

Novel Splice Variants of PIPKIgamma Provide Biomarkers for Breast Cancer Diagnosis and Prognosis

UW-Madison researchers have identified novel variants of PIPKIgamma that could be used to monitor breast cancer progression and determine prognosis.  The variants correlate with key markers of breast cancer progression, including the loss of E-cadherin and increased HER1 or HER2 expression.

HPV-Positive Biomarkers for Cervical and Head and Neck Cancers

UW-Madison researchers have identified three potential biomarkers that are specific for HPV-positive cancers in cervical and head and neck tumors: testicular cell adhesion molecule 1 (TCAM1), synaptonemal complex protein 2 (SYCP2) and stromal antigen 3 (STAG3).  These biomarkers can be used to detect cervical or head and neck cancer.  TCAM1 and SYCP2 also can be used to detect precancerous lesions.

TCAM1, SYCP2 and STAG3 are testis-specific human genes.  The inventors have shown that mRNA from these genes is expressed in HPV-positive head and neck and cervical cancers but cannot be detected in normal somatic tissues or HPV-negative head and neck cancers.

Additionally, the TCAM1 protein likely is expressed on the cell surface, which would make it an accessible, easily-assayed biomarker for HPV-positive cells in cancers and precancerous lesions.  TCAM1 also may provide a useful target for therapies against HPV-positive cancers and precancerous lesions.

Prostate Cancer and Melanoma Screening

UW-Madison researchers have developed a minimally invasive method of screening for prostate cancer or melanoma. They identified a number of antigens to which patients with prostate cancer or melanoma have developed antibody immune responses. The antigens may provide clinicians with new tools for the diagnosis and monitoring of prostate cancer or melanoma. A blood sample from a patient can be tested against a panel of the prostate cancer or melanoma antigens. An immune reaction to any member of the panel might indicate the patient needs further examination.

The researchers also developed a method for determining if an anti-cancer immune therapy is effective. Anti-tumor vaccines stimulate the immune system to form antibodies against tumor cells, delaying the onset or progression of cancer. The panel of antigens can be used to determine if an immune therapy, either antigen-specific or non-antigen-specific, has elicited responses to other antigens and might therefore be an effective therapy. In addition, the antigens themselves may serve as targets for antigen-specific immune therapies.

Method of Analyzing Breast Cancer Susceptibility

UW-Madison researchers have developed a method of analyzing breast cancer susceptibility based on a subject’s DNA. They used quantitative trait locus (QTL) mapping, a method of matching genes to expressed traits, to identify several loci that are correlated with breast cancer susceptibility. If certain alleles are present at those loci, the risk of breast cancer may be increased or decreased up to 19 percent. To determine an individual’s risk of developing breast cancer, a sample of their DNA is genotyped to identify the presence of any of those alleles.

MiR-155 Assay Provides a Diagnostic Test Indicative of B-Cell Lymphoma

UW-Madison researchers have developed a method of using the amount of a particular miRNA to diagnose B-cell lymphoma and determine a patient’s prognosis. They identified a correlation between miR-155 and clinically important types of lymphoma. Clinical isolates of several types of B-cell lymphomas, including diffuse large B-cell lymphoma (DLBCL), have 10- to 30-fold higher copy numbers of miR-155 than do normal circulating B-cells. In addition, significantly higher levels of miR-155 are present in DLBCLs with an activated B-cell phenotype, which is associated with a poorer clinical prognosis.

B-cell lymphoma can be diagnosed in a patient by determining the amount of miR-155 in a biopsy sample of the patient’s B-cells; a high level in the patient’s sample indicates lymphoma. The patient’s sample can also be compared to samples of DLBCL cells with a non-activated germinal center phenotype. More miR-155 in the patient’s sample indicates an activated B-cell phenotype and poorer prognosis.

Early Detection of Hemangiosarcoma and Angiosarcoma

UW-Madison researchers have developed a simple, sensitive and specific test for detecting hemangiosarcoma in its early stages in dogs at risk. The inventors discovered that the “primitive” endothelial cells associated with hemangiosarcoma or angiosarcoma, a similar tumor that affects humans, express a specific combination of proteins on their surface. To diagnose hemangiosarcoma or angiosarcoma, multiparameter flow cytometry can be used to detect cells that express these proteins.

Estrogen-Related Receptor Gamma, a Breast Cancer Biomarker and Target for Treatment

UW-Madison researchers have developed methods for using ERR-gamma as both a breast cancer biomarker and a target for treatment. As a biomarker, it provides a method of determining a patient’s breast cancer prognosis. Expression levels of ERR-gamma are analyzed along with the status of other genes related to breast cancer to help breast cancer patients and their doctors make treatment choices. A high level of ERR-gamma in breast cancer cells indicates good prognosis and a high likelihood of being sensitive to hormonal blockade therapy such as tamoxifen therapy. The receptor also provides a target for treating breast cancer, which involves decreasing the activity of ERR-gamma in breast cancer cells.

Marker Sequences for Liver and Other Cancers

UW-Madison researchers have identified polypeptides whose expression is upregulated in liver tumor cells and cells from pre-neoplastic foci in liver tissue. These polypeptides may be overexpressed in tumor and pre-neoplastic cells in general; the researchers have so far demonstrated their overexpression in human breast, colon and kidney cancer cell lines, in addition to liver tumors.

Liver Tumor Marker Sequences

UW-Madison researchers have developed novel polypeptides and nucleic acids that are differentially expressed in liver tumors relative to normal liver tissues. The researchers initially isolated these sequences by using representational difference analysis (RDA), and then cloned the entire coding region of the genes. One polypeptide they identified is CRG-L1, which includes seven putative transmembrane domains. CRG-L1 is over-expressed in liver tumors, but expressed at fairly low levels in normal liver tissues.

The C-myc Coding Region Determinant Binding Protein (CRD-BP) and Its Nucleic Acid Sequence

A UW-Madison researcher has identified a coding region determinant binding protein (CRD-BP) that stabilizes c-myc mRNA by binding to the coding region determinant (CRD) on c-myc, thereby increasing the abundance of c-myc protein. Several properties of the CRD-BP link it to human cancer, including a recent study where 15 out of 21 colon cancer specimens were positive for CRD-BP expression. The cancer-related protein can be detected by examining patient tissue and comparing the expression level with control levels.

hMREII Antiserum for the Detection of DNA Damage

A UW-Madison researcher has now isolated such a homolog by using a two-hybrid system to determine which proteins interact with the repair enzyme, DNA ligase I. The gene, termed hMREII, maps to human chromosome 11q21 in a region frequently associated with cancer-related chromosomal abnormalities.

The researcher cloned a 1900 base pair portion of the hMREII gene into a bacterial expression vector and used the bacterially produced and purified hMREII to immunize rabbits. The resulting antiserum detects the hMre11 protein, which has been shown to associate with radiation-induced double stranded DNA breaks, as well as human telomeres. Congenitally acquired defects in hMre11 and its binding partner, Nbs1, result in cancer predisposition and ionizing radiation sensitivity; in these diseases, the localization of hMre11 to DNA breaks is compromised. Thus, the antiserum is useful for detecting DNA damage and assessing the functional status of hMre11 and its associated proteins. The Mre11 complex, consisting of these proteins, is a central mediator of DNA damage responses in all eukaryotic cells.