Her-2/neu and fibrinolytic factors in human breast-cancer.

HER-2/neu status and t-PA, u-PA, and PAI-1 cytosol content were evaluated in 88 primary breast cancer patients to determine the relationships between these parameters. HER-2/neu was amplified in 24% (20/84) of tumor samples and overexpressed in 28% (14/50). In the overall series, median t-PA, u-PA and PAI-1 contents, measured by the enzyme-linked immmunoassay (ELISA), resulted in 1.7, 1.1 and 1.0 ng/mg cytosol protein (cyt prot), respectively. HER-2/neu overexpressed cases showed higher u-PA levels than those normally expressed whereas t-PA and PAI-1 levels did not vary in HER-2/neu altered and non altered cases. The t-PA levels did not differ in cases with or without HER-2/neu alterations, when separately considering the node-negative and node-positive cases. A significant relationship between t-PA levels and HER-2/neu alterations was observed only in the ER(+) tumors: t-PA levels were lower in amplified and overexpressed cases (1.4 versus 2.5 ng/mg cyt prot in amplified and single copy gene, respectively; 1.6 versus 2.3 ng/mg cyt prot in overexpressed and normally expressed cases, respectively). Therefore, t-PA and HER-2/neu could provide additional prognostic information for ER-negative patients.

HER-2/neu, c-Myc and cyclin-A in human breast cancer.

To better understand the role of HER-2/neu, c-myc and cyclin-A which seem to be activated in different steps of tumor cell growth, we analyzed a series of breast cancers from patients subjected to radical mastectomy with regard to HER-2/neu amplification (N=171) and expression of HER-2/neu (N=114), c-myc (N=31) and cyclin-A (N=71). Molecular evaluation demonstrated that HER-2/neu was amplified in 20% of cases and overexpressed in 27%, and its alterations were associated with a higher proliferative activity (H-3-Tdr-labeling index), although not statistically significant in patients without lymph node metastases, c-myc was overexpressed in 16% of cases and was weakly correlated to proliferation activity. Cyclin-A was overexpressed in 15% of cases and was significantly correlated to the percentage of the H-3-Tdr labeled cell fraction (p=0.002). Cyclin-A alterations were also significantly associated with well-differentiated tumors, suggesting that this gene could be involved in the control of the normal cell cycle rather than to cell proliferation during tumor growth.

HER-2/neu gene in primary and local metastatic axillary lymph nodes in human breast tumors.

In order to verify whether the HER-2/neu gene is involved in the initial phases of neoplastic disease or in its progression, we evaluated the amplification and overexpression of this gene in the primary tumor and in synchronous metastatic axillary lymph nodes of 26 women with operable breast cancer. HER-2/neu was amplified in 35% and overexpressed in 33% of the primary sites; similar percentages were found in lymph nodes. The clear correlation between the two disease sites regarding gene, mRNA and protein levels, supports the hypothesis that this gene is involved in the initial and invasive phases of neoplasia. Its actual role with respect to other biological tumor characteristics during the metastatic process should be investigated further.

Immunoglobulin heavy chain gene rearrangement in B-cell non-Hodgkin's lymphomas detected by the polymerase chain reaction.

AIMS AND BACKGROUND: Immunoglobulin heavy chain gene rearrangement serves as a marker of clonality and cell lineage in B-cell lymphoproliferative disorders. In this study we used the polymerase chain reaction (PCR) to detect clonal rearrangements of the immunoglobulin heavy chain gene in a group of patients with B-cell lymphomas. METHODS: DNA was extracted from frozen tissue of 40 B-cell non-Hodgkin's lymphomas and subjected to PCR amplification using primers that recognize conserved sequences of the variable and joining regions of the immunoglobulin heavy chain gene. RESULTS: Monoclonal rearrangements were detected in 23 of 40 malignant B-cell lymphomas. No clonal rearrangements were detected in the 10 control cases. CONCLUSIONS: We conclude that this PCR-based technique may provide a simplified and rapid approach for the detection of clonal immunoglobulin heavy chain gene rearrangements in B-cell lymphomas without recourse to Southern blotting, which can be reserved for cases in which PCR is negative.

Different assays for HER-2/neu evaluation in breast cancer.

To evaluate different methodologic approaches for HER-2/neu analysis, we performed Southern, Northern, Western blot and histochemical assay on 112 samples from 86 primary tumors and 26 synchronous axillary metastatic lymph nodes of patients affected by operable breast cancer. Simultaneous statistical analysis of data obtained with the four methods (31 samples) showed that Western blot detected a higher percentage of alterations than the other assays (Cochran and Victor tests, 0.01 less than p less than 0.05). The same result was emphasized by pair analysis (McNemar, p less than 0.05), which evaluated the assay data two by two. Immunohistochemical evaluations were more in accord with immunoprecipitation data when performed on frozen or Bouin-fixed, paraffin-embedded tissues than on formalin-fixed, paraffin-embedded tissues.

The effect of fixation type on DNA extracted from paraffin-embedded tissue for PCR studies in dermatopathology.

BACKGROUND: Amplification of nucleic acids from paraffin-embedded material by the polymerase chain reaction (PCR) is widely used to detect viral genomes, clonal gene rearrangements and oncogene mutations in skin specimens. Fixation with embedding of skin tissue is a procedure that has a profound effect on its molecular arrangement. OBJECTIVE: The aim of this study was to determine the effect of different fixatives on the PCR amplification of DNA. METHODS: We fixed randomly chosen fresh pathologic skin specimens in formalin, ethanol and Histochoice for 24 and 72 h and then embedded the tissue in paraffin. DNA was extracted from the paraffin-embedded tissues and used as template for amplification, producing 530- and 760-bp fragments of the phosphoglycerokinase gene. RESULTS: Our results indicate that PCR can be performed with excellent results on ethanol- and Histochoice-fixed, paraffin-embedded skin tissue with a rate of success comparable to that using fresh tissues; formalin-fixed tissue gave slightly less satisfactory results. CONCLUSION: This investigation corroborates previous reports investigating the effect of ethanol and formalin fixation on DNA amplification by PCR. Moreover, this is the first study showing that DNA extracted from tissue fixed with Histochoice is suitable for PCR gene amplification.

Comparison of formalin, ethanol, and Histochoice fixation on the PCR amplification from paraffin-embedded breast cancer tissue.

The polymerase chain reaction (PCR) has been successfully employed for the laboratory analyses of genetic and infectious disorders using DNA extracted from paraffin-embedded tissues. However, fixative type and fixation time influenced PCR reactions and in some circumstances amplification fragments could not be efficiently generated. In this study, we determined the effects of three commonly used fixatives including ethanol, formalin and Histochoice, on the PCR amplification of DNA from paraffin-embedded breast cancer tissue. The effect of fixatives and fixation times was measured by the ability of the extracted DNA to serve as a template for the amplification of 280 and 530 base pair DNA fragments. On amplifying DNA, positive reactions were uniformly seen in the ethanol specimens. The next best fixative was Histochoice with positive results almost constantly observed in the PCR reactions performed. Formalin fixation sometimes compromised DNA amplification. Our results are consistent with previous reports investigating the effect of ethanol and formalin fixation on DNA amplification by PCR. Moreover, this is the first study showing that paraffin-embedded tissues fixed with Histochoice can be efficiently used for PCR gene amplification.