A preliminary study on the detection of lymph node metastasis in cervical cancer using a quantitative RT-PCR assay

OBJECTIVE

This preliminary study aimed to assess the detection accuracy of sentinel lymph node metastasis in cervical cancer using quantitative reverse transcriptase-polymerase chain reaction.

METHODS

We collected cervical cancer tissues and 70 pelvic lymph node samples from patients with cervical cancer. The quantitative reverse transcriptase-polymerase chain reaction assay was performed to investigate the expression of cytokeratin 19 mRNA in cervical cancer tissues and determine the cutoff value of cytokeratin 19 mRNA between the non-metastatic and metastatic lymph nodes.

RESULTS

The expression of cytokeratin 19 mRNA in cancer tissues was detected in all (71/71) the tumours, with a median copy number of 7.56 × 105/μl of RNA by quantitative reverse transcriptase-polymerase chain reaction. Sixteen lymph nodes were diagnosed as positive by pathological examination. The median copy numbers of cytokeratin 19 mRNA for positive and negative lymph nodes were 43.3 × 104/μl and 121.1/μl, respectively. The expression of cytokeratin 19 mRNA in pathologically positive lymph nodes was higher than that in the negative lymph nodes (P < 0.0001) by quantitative reverse transcriptase-polymerase chain reaction analysis. Using a receiver operating characteristic plot, the maximum sensitivity (100%) and specificity (94.4%) were obtained when the cutoff value was set at 1169 copies/μl.

CONCLUSIONS

After setting the cutoff value at 1169 copies/μl, a quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA showed high accuracy in detecting lymph node metastasis in cervical cancer. We believe that the quantitative reverse transcriptase-polymerase chain reaction assay using cytokeratin 19 mRNA may be acceptable for lymph node metastasis detection in patients with cervical cancer.

Quantitative RT-PCR Assay for Detecting Lymph Node Metastasis in Endometrial Cancer: A Preliminary Study

OBJECTIVE

The detection accuracy of sentinel lymph node (SLN) metastasis by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) for endometrial cancer (EC) remains unclear and was assessed in this preliminary study.

METHODS

We studied primary cancer tissues and pelvic lymph nodes (PLN) from 105 patients with EC. qRT-PCR assay was performed to determine the copy numbers of CK19 mRNA in EC tissues, and negative and positive LN samples. Further, qRT-PCR results were compared with pathological findings.

RESULTS

CK19 mRNA expression was detected in 98% (104/106) of the tumors, with a median copy number of 3.0 × 105/μL. Twelve LN were diagnosed as positive by pathological examination. The median copy number of CK19 mRNA for positive and negative LN was 8.1 × 104/μL and 90.4/µL, respectively. CK19 mRNA expression was higher in pathologically positive LN than in pathologically negative LN (p < 0.01); the pathological and qRT-PCR findings showed no discrepancy. When the cutoff value was set at 4,500 copies/µL, qRT-PCR assay using CK19 mRNA exhibited high sensitivity and specificity.

CONCLUSIONS

Our results demonstrated that qRT-PCR assay, using CK19 mRNA, exhibits a high accuracy for detecting LN metastasis in EC and represents a useful alternative to conventional pathological diagnosis of EC.

Radixin knockdown by RNA interference suppresses human glioblastoma cell growth in vitro and in vivo

Radixin, a member of the ERM (ezrin-radixin-moesin) family, plays important roles in cell motility, invasion and tumor progression. It is expressed in a variety of normal and neoplastic cells, including many types of epithelial and lymphoid examples. However, its function in glioblastomas remains elusive. Thus, in this study, radixin gene expression was first examined in the glioblastoma cells, then suppressed with a lentivirus-mediated short-hairpin RNA (shRNA) method.We found that there were high levels of radixin expression in glioblastoma U251cells. Radixin shRNA caused down-regulation of radixin gene expression and when radixin-silenced cells were implanted into nude mice, tumor growth was significantly inhibited as compared to blank control cells or non- sense shRNA cells. In addition, microvessel density in the tumors was significantly reduced. Thrombospondin-1 (TSP-1) and E-cadherin were up-regulated in radixin- suppressed glioblastoma U251 cells. In contrast, MMP9 was down-regulated. Taken together, our findings suggest that radixin is involved in GBM cell migration and invasion, and implicate TSP-1, E-cadherin and MMP9 as metastasis-inducing factors.

Immunohistochemical characterization of neoplastic cells of breast origin

Background

After skin cancer, breast cancer is the most common malignancy in women. Tumors of unknown origin account for 5-15% of malignant neoplasms, with 1.5% being breast cancer. An immunohistochemical panel with conventional and newer markers, such as mammaglobin, was selected for the detection of neoplastic cells of breast origin. The specific objectives are: 1) to determine the sensitivity and specificity of the panel, with a special emphasis on the inclusion of the mammaglobin marker, and 2) to compare immunohistochemistry performed on whole tissue sections and on Tissue Micro-Array.

Methods

Twenty-nine metastatic breast tumors were included and assumed as tumors of unknown origin. Other 48 biopsies of diverse tissues were selected and assumed as negative controls. Tissue Micro-Array was performed. Immunohistochemistry for mammaglobin, gross cystic disease fluid protein-15, estrogen receptor, progesterone receptor and cytokeratin 7 was done.

Results

Mammaglobin positive staining was observed in 10/29 cases, in 13/29 cases for gross cystic disease fluid protein-15, in 20/29 cases for estrogen receptor, in 9/29 cases for progesterone receptor, and in 25/29 cases for cytokeratin 7. Among the negative controls, mammaglobin was positive in 2/48, and gross cystic disease fluid protein-15 in 4/48.

Conclusions

The inclusion of MAG antibody in the immunohistochemical panel for the detection of tumors of unknown origin contributed to the detection of metastasis of breast cancer. The diagnostic strategy with the highest positive predictive value (88%) included hormone receptors and mammaglobin in serial manner.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1366310812718988

Down-regulation of the oncogene cyclin D1 increases migratory capacity in breast cancer and is linked to unfavorable prognostic features

The oncogene cyclin D1 is highly expressed in many breast cancers and, despite its proliferation-activating properties, it has been linked to a less malignant phenotype. To clarify this observation, we focused on two key components of malignant behavior, migration and proliferation, and observed that quiescent G(0)/G(1) cells display an increased migratory capacity compared to cycling cells. We also found that the down-regulation of cyclin D1 in actively cycling cells significantly increased migration while also decreasing proliferation. When analyzing a large set of premenopausal breast cancers, we observed an inverse proliferation-independent link between cyclin D1 and tumor size and recurrence, suggesting that this protein might abrogate infiltrative malignant behavior in vivo. Finally, gene expression analysis after cyclin D1 down-regulation by siRNA confirmed changes in processes associated with migration and enrichment of our gene set in a metastatic poor prognosis signature. This novel function of cyclin D1 illustrates the interplay between tumor proliferation and migration and may explain the attenuation of malignant behavior in breast cancers with high cyclin D1 levels.

Implications of cancer-associated systemic inflammation for biomarker studies

Highly sensitive molecular technologies provide new capacities for cancer biomarker research, but with sensitivity improvements marker specificity is significantly decreased, and too many false-positive results should disqualify the measurement from clinical use. Hence, of the thousands of potential cancer biomarkers only a few have found their way to clinical application. Differentiating false-positive results from true-positive (cancer-specific) results can indeed be difficult, if validation of a marker is performed against inadequate controls. We present examples of accumulating evidence that not only local but also systemic inflammatory reactions are implicated in cancer development and progression and interfere with the molecular image of cancer disease. We analyze several modern strategies of tumor marker discovery, namely, proteomics, metabonomics, studies on circulating tumor cells and circulating free nucleic acids, or their methylation degree, and provide examples of scarce, methodologically correct biomarker studies as opposed to numerous methodologically flawed biomarker studies, that examine cancer patients' samples against those of healthy, inflammation-free persons and present many inflammation-related biomarker alterations in cancer patients as cancer-specific. Inflammation as a cancer-associated condition should always be considered in cancer biomarker studies, and biomarkers should be validated against their expression in inflammatory conditions.

Molecular markers of breast axillary lymph node metastasis

In breast cancer, axillary lymph node status is one of the most important prognostic variables and a crucial component to the staging system. Several clinico-histopathological parameters are considered to be strong predictors of metastasis; however, they fail to accurately classify breast tumors according to their clinical behavior and to predict which patients will have disease recurrence. Methods based on genome-wide microarray analyses have been used to identify molecular markers with respect to the development of axillary lymph node metastasis. Most of these markers can be detected in the primary tumors, which can potentially lead to the ability to identify patients at the time of diagnosis who are at high risk for lymph node metastasis, allowing for early intervention and more suitable adjuvant treatments.