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Biomedical subjects

J Zwiebel

Publications and source records attributed to J Zwiebel.

7 recordsLinked to original sources
PubMed2001

Replication-selective virotherapy for cancer: Biological principles, risk management and future directions.

In the search for novel cancer therapies that can be used in conjunction with existing treatments, one promising area of research is the use of viral vectors and whole viruses. This review describes the underlying biological principles and current status of the field, outlines approaches for improving clinical effectiveness and discusses the unique safety and regulatory issues surrounding viral therapies.

Biological Therapy↗
PubMed1994

p53Val135 temperature sensitive mutant suppresses growth of human breast cancer cells.

One common step in the malignant progression of a wide variety of human cancers seems to be inactivation of the p53 gene, via point mutation or deletion or both; or overexpression of mutated protein with dominant transforming activity. This study shows a suppressive effect of wild type p53 on the growth of human breast cancer cells. Introduction of wild type p53 versus mutant into five human breast cancer cell lines containing mutant p53 resulted in a marked reduction in colony formation. Two of these were transfected with human wt p53 expression vectors and the other three were infected with retroviruses packaging human wt p53, both showing similar reduction in the number of surviving colonies, suggesting a role for wt p53 in suppression of breast cancer cell growth. Direct evidence for growth suppression was obtained by introduction of the temperature sensitive p53Val135 into Hs578T human breast cancer cells containing a mutant p53. This murine mutant allele p53Val135 functions as an oncogene at 37 degrees C as a tumor suppressor at 32 degrees C. The cell line generated was strongly growth inhibited at the restrictive temperature (31.5 degrees C), at which temperature the suppressor form is expressed. This inhibition of proliferation was reversible upon a temperature upshift. Analysis of the cell cycle distribution shows these growth suppressed cells to be inhibited in the G1 phase of the cell cycle. Thus wt p53 may have an important role in breast cancer tumorigenesis.

3T3 Cells↗
PubMed1993

Fibroblast growth factor 4 transfection of MCF-7 cells produces cell lines that are tumorigenic and metastatic in ovariectomized or tamoxifen-treated athymic nude mice.

Successful antiestrogen treatment in patients with tamoxifen-responsive breast tumors is often followed by an outgrowth of tumors cells that are antiestrogen resistant, implying that estrogen-dependent tumors can become estrogen-independent. In an effect to mimic this progression, we have transfected fibroblast growth factor 4 into MCF-7 cells, a human breast carcinoma cell line that is estrogen-dependent for growth in nude mice. This transfection results in cell lines that form progressively growing, metastatic tumors when injected s.c. into untreated or tamoxifen-treated ovariectomized nude mice. In contrast to the parental cell line, growth of transfected cells in ovariectomized nude mice is stimulated by tamoxifen treatment and inhibited by estrogen treatment of the mice. Parental MCF-7 cells were transfected with an expression vector for beta-galactosidase, conferring the ability to convert the chromogenic substrate, 5-bromo-4-chloro-3-indoyl-beta-galactoside, to a blue color and allowing the detection of their presence within tumors developing after coinoculation with fibroblast growth factor 4-transfected cells. The fibroblast growth factor 4-transfected cells could support growth and metastasis of the beta-galactosidase-expressing parental cell line when both lines were coinjected into the same site in untreated or tamoxifen-treated, ovariectomized mice. These data suggest a possible role for fibroblast growth factors in the progression of breast tumors to an estrogen-independent, antiestrogen-resistant, metastatic phenotype. They also support a role for paracrine factors in mixed populations of tumor cells of differing states of malignant progression.

Animals↗