Method for discrimination of metaplasias from neoplastic or preneoplastic lesions
The present invention relates to a method for discrimination of p16 INK4a overexpressing metaplasias from neoplastic or preneoplastic p16 INK4a overexpressing lesions by determination of the level of high risk HPV encoded gene-products such as e.g. HPV E2 and/or HPV E7 molecules in biological samples in the course of cytological testing procedures. The method thus enables for reduction of false positive results in the p16 INK4a based detection of anogenital lesions in cytological testing procedures.
1. A method for discrimination of p16 INK4a overexpressing metaplasias from p16 INK4a overexpressing neoplastic or preneoplastic lesions in a uterine cervix sample by cytological testing procedures, comprising:
(a) measuring the presence or absence of cells overexpression of p16 INK4a in said sample;
(b) measuring the presence or absence of cells expressing at least one high risk HPV gene-product in said sample, wherein said high risk HPV gene-product is a polypeptide encoded by HPV E7 gene, HPV E2 gene, HPV E6 gene, HPV L1 gene, or HPV L2 gene;
(c) assessing simultaneous presence of cells expressing the high risk HPV gene-products with cells overexpressing p16 INK4a , or assessing presence of cells overexpressing p16 INK4a alone;
(d) determining the simultaneous presence of cells expressing high risk HPV gene-products with cells overexpressing p16 INK4a as indicative of neoplastic or preneoplastic lesion; and
(e) determining the presence of cells overexpressing p16 INK4a alone as indicative of metaplasias.
2. The method according to claim 1 , wherein the high risk HPV gene-product is encoded by the HPV E7 gene.
3. The method according to claim 1 , wherein the high risk HPV gene-product is encoded by HPV E2 or or HPV E6 gene.
4. The method according to claim 1 , wherein the high risk HPV gene-product is encoded by HPV L1 or HPV L2 gene.
5. The method according to claim 1 , wherein the sample is a Pap smear or a cytological preparation of the cervix uteri.
6. The method according to claim 1 , wherein the measurements of the HPV gene-products and of p16 IMK4a are performed using antibodies specific for the HPV gene-products and p16 INK4a .
7. The method according to claim 5 , wherein the antibodies are detectably labelled.
8. The method according to claim 6 , wherein the label is selected from the group consisting of a radioisotope, a bioluminescent compound, a chemiluminescent compound, a fluorescent compound, and an enzyme.
9. The method according to claim 1 , wherein the cytological testing procedures comprise an immuno-cytochemical staining procedure.
10. The method according to claim 1 , wherein the measurements of the high-risk HPV gene-product and p16 INK4a are carried out simultaneously.
11. The method according to claim 10 , wherein overexpression of p16 INK4a and expression of at least one high risk HPV gene-product are simultaneous determined in at least one single cell.