Patent US4980281A successfully refreshed from Google Patents.
US4980281A
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Method of screening for protein inhibitors and activators
Assignee: Housey Pharmaceuticals Inc
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Filing: 1988-02-10
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Granted: 1990-12-25
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Expires: 2008-02-10
Abstract
Abstract Inhibitors and activators of a protein whose expression affects a phenotypic characteristic of the cell, especially a cultural or morphological characteristic, are identified by their more pronounced effect on cells producing higher, usually non-naturally occurring, levels of the protein, than on cells producing little or none of the protein. In a preferred assay, the effect is observable with the naked eye. By this method, tamoxifen is identified as an inhibitor of PKC activity in cell culture.
Inventors
- 👤 Gerard M. Housey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:38
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/5005; G01N33/5008; G01N33/5011; C; C12; C12N; C12N9/00; C12N9/10; C12N9/12; G01N33/5014; G01N33/5017; G01N33/502; G01N33/5023; G01N33/5026
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
141 words
A method of determining whether a substance is an inhibitor or activator of a protein whose production by a cell evokes a responsive change in a phenotypic characteristic other than the level of said protein in said cell per se, which comprises: (a) providing a first cell line which produces said protein and exhibits said phenotypic response to the protein; (b) providing a second cell line which produces the protein at a lower level than the first cell line, or does not produces the protein at all, and which exhibits said phenotypic response to the protein to a lesser degree or not at all; (c) incubating the substance with the first and second cell lines; and (d) comparing the phenotypic response of the first cell line to the substance with the phenotypic response of the second cell line to the substance.
Claim 2
Independent Claim
141 words
A method of determining whether a substance is an inhibitor or activator of a protein whose production by a cell evokes a responsive change in a phenotypic characteristic other than the level of said protein in said cell per se, which comprises: (a) providing a first cell line which produces said protein and exhibits said phenotypic response to the protein; (b) providing a second cell line which produces the protein at a lower level than the first cell line, or does not produces the protein at all, and which exhibits said phenotypic response to the protein to a lesser degree or not at all; (c) incubating the substance with the first and second cell lines; and (d) comparing the phenotypic response of the first cell line to the substance with the phenotypic response of the second cell line to the substance.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein the response is one observable with the naked eye.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the response is a change in a cultural or morphological characteristic of the cell.
Claim 5
Dependent Claim
24 words
The method of claim 1 wherein the response is a change in the ability of the cell line to grow in an anchorage-independent fashion.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein the response is a change in the ability of the cell line to grow on soft agar.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein the response is a change in foci formation in cell culture.
Claim 8
Dependent Claim
22 words
The method of claim 1 wherein the response is a change the ability of the cells to take up a selected stain.
Claim 9
Dependent Claim
12 words
The method of claim 1 in which the protein is an enzyme.
Claim 10
Dependent Claim
16 words
The method of claim 8 wherein increased activity of the enzyme is correlated with increased tumorigenesis.
Claim 11
Dependent Claim
30 words
The method of claim 9 in which the enzyme is a protein kinase C enzyme or a fragment, domain, or subunit of a receptor which has protein kinase C activity.
Claim 12
Dependent Claim
11 words
The method of claim 9 wherein the enzyme is ornithine decarboxylase.
Claim 13
Dependent Claim
16 words
The method of claim 9 in which the protein is the expression product of an oncogene.
Claim 14
Dependent Claim
20 words
The method of claim 1 in which the substance is a suspected inhibitor of the biological activity of the protein.
Claim 15
Dependent Claim
20 words
The method of claim 1 in which the substance is a suspected activator of the biological activity of the protein.
Claim 16
Dependent Claim
44 words
The method of claim 1, wherein said first cell line is obtained by introducing a gene encoding the protein of interest into a host cell, said gene being under the control of a promoter functional in the host cell, whereby said gene is expressed.
Claim 17
Dependent Claim
62 words
The method of claim 15, wherein the gene is introduced into the host cell by means of a first genetic vector into which the gene has been inserted, and said second cell line is obtained by introducing into a similar host cell a second genetic vector essentially identical to the first genetic vector except that it does not bear said gene insert.
Claim 18
Dependent Claim
20 words
The method of claim 15 wherein the gene is introduced into the host cell by means of a retroviral vector.
Claim 19
Dependent Claim
17 words
The method of claim 15 in which the host cell line essentially does not produce the protein.
Claim 20
Dependent Claim
17 words
The method of claim 15 in which the host cell line is a rat-6 fibroblast cell line.
Claim 21
Dependent Claim
19 words
The method of claim 3 in which the response is a change in the differentiation state of the cell.
Claim 22
Dependent Claim
18 words
The method of claim 1 wherein the response is a change in an antigenic characteristic of the cell.
Claim 23
Dependent Claim
99 words
A test kit for determining whether a substance is an inhibitor or activator of a protein whose production evokes a responsive change in a phenotypic characteristic other than level of said protein in said cell per se, which comprises: (a) a first animal cell line which produces the protein and exhibits said phenotypic response thereto; and (b) a second animal cell line which produces the protein at a lower level than the first animal cell line, or does not produce the protein, and which exhibits said phenotypic response to the protein to a lesser degree or not at all.
Claim 24
Dependent Claim
99 words
A test kit for determining whether a substance is an inhibitor or activator of a protein whose production evokes a responsive change in a phenotypic characteristic other than level of said protein in said cell per se, which comprises: (a) a first animal cell line which produces the protein and exhibits said phenotypic response thereto; and (b) a second animal cell line which produces the protein at a lower level than the first animal cell line, or does not produce the protein, and which exhibits said phenotypic response to the protein to a lesser degree or not at all.
Claim 25
Dependent Claim
35 words
The test kit of claim 22, wherein the level of production of the protein in the first cell line is at least five times the level of production of the protein in the second line.
Claim 26
Dependent Claim
41 words
The test kit of claim 22, wherein the phenotypic response to expression of the protein is selected from the group consisting of changes in growth rate, saturation density, plating efficiency in soft agar, colony size in soft agar, and combinations thereof.
References Cited (Backward Citations)
US4480038A
Cited
US4532204A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |