Related Experiment Videos
Expression of MaTu-MN protein in human tumor cultures and in clinical specimens
J Závada1, Z Závadová, S Pastoreková
1Institute of Virology, Slovak Academy of Sciences, Bratislava.
Abstract:
MaTu is a novel agent which may be of relevance in human oncogenesis, and has 2 components. One of them, the exogenous MX (coding for protein p58X), is transmissible to human fibroblasts, to HeLa and to HeLa x fibroblast (H/F) hybrids. The other component, MN, is a cellular gene. Its product, the protein p54/58N, is inducible by infecting HeLa cells with MX or by growing them in dense cultures. This p54/58N appears to be a tumor-associated antigen: it is expressed in HeLa and in tumorigenic cells (H/F-T), but not in fibroblasts or in nontumorigenic hybrid cells (H/F-N). Proteins related to p54/58N were also found on immunoblots prepared from human carcinomas of ovary, endometrium and uterine cervix, but not from normal tissues from corresponding organs or from placenta. Using genetically engineered MN protein, we developed a radioimmunoassay for MN-specific antibodies, and for quantitative determination of MN proteins in cell extracts. In HeLa cells infected with MX we observed conspicuous ultrastructural alterations: formation of abundant filaments on the cell surface and amplification of mitochondria. Using immunogold-staining, we visualized the p54/58N on the surface microvilli and in the nucleus, particularly in nucleoli.
Insights
The novel agent MaTu, comprising exogenous MX and cellular MN, influences human oncogenesis. The MN protein (p54/58N) acts as a tumor antigen, found in carcinomas but not normal tissues.
Area of Science:
- Oncology
- Molecular Biology
- Cell Biology
Background:
- MaTu is a novel agent with two components: exogenous MX and cellular MN.
- The MX component codes for protein p58X and is transmissible to human cells.
- The MN component is a cellular gene producing protein p54/58N.
Purpose of the Study:
- To investigate the role of MaTu components in human oncogenesis.
- To characterize the expression and localization of the MN protein (p54/58N).
- To develop diagnostic tools for MN-specific antibodies and proteins.
Main Methods:
- Infection of human fibroblasts, HeLa cells, and hybrids with MX.
- Induction of MN protein in HeLa cells via MX infection or dense culture.
- Analysis of protein expression in various cell lines and human carcinoma tissues using immunoblots.
- Development of a radioimmunoassay for MN-specific antibodies and protein quantification.
- Ultrastructural analysis of HeLa cells infected with MX using immunogold-staining.
Main Results:
- The MN protein (p54/58N) is identified as a tumor-associated antigen, expressed in HeLa and tumorigenic hybrid cells (H/F-T), but absent in fibroblasts and non-tumorigenic hybrids (H/F-N).
- Proteins related to p54/58N are detected in human ovarian, endometrial, and cervical carcinomas, but not in normal tissues or placenta.
- MX infection induces significant ultrastructural changes in HeLa cells, including surface filaments and mitochondrial amplification.
- Immunogold-staining localizes p54/58N to the cell surface microvilli and within the nucleus, particularly nucleoli.
Conclusions:
- The MN protein (p54/58N) is a potential biomarker for human carcinomas.
- The MaTu agent, through its components MX and MN, influences cellular characteristics relevant to oncogenesis.
- Further research into MaTu's mechanism of action and diagnostic potential is warranted.