The MTS1/CDKN2/p16 gene encoding the p16INK4a tumor-suppressor protein is usually inactivated by homozygous deletion or hypermethylation of the promoter in a variety of human malignancies. In choose tumor varieties, together with pancreatic adenocarcinomas, intragenic mutations are present in a big share of instances.
The immunoreactivity of mutant p16 proteins has not been comprehensively studied. Furthermore, the immunohistochemical properties of commercially obtainable antibodies haven’t been described intimately. We studied 35 pancreatic adenocarcinomas with a molecularly outlined p16 standing (16 homozygous deletions, Three hypermethylated instances, and 16 tumors with an intragenic mutation in a single allele related to lack of the second allele).
As well as, we studied 9 cell traces (three homozygous deletions, three hypermethylated traces, and three intragenic mutations). Paraffin sections of the tumors and cell blocks had been reacted with 4 totally different anti-p16 antibodies: polyclonal and monoclonal (clone G175-405) antibodies from PharMingen, monoclonal antibody DCS-50 from Oncogene Science, and monoclonal antibody ZJ11 from Neo-Markers.
Optimum staining situations had been established for every antibody. The pancreatic carcinomas with homozygous p16 deletions had been largely devoid of nuclear staining (admixed nonneoplastic cells served as inside constructive controls); just one adenocarcinoma every reacted with DCS-50 and the polyclonal antibody, and 5 had been constructive with ZJ11, suggesting that nonspecific nuclear staining can happen below sure situations.
Antibody DCS-50 produced nuclear staining in all three hypermethylated carcinomas, whereas G175-405 stained none of them. Three of the 4 antibodies produced nuclear immunoreactivity in 7 to 14 of the 16 carcinomas carrying p16 mutations; G175-405 confirmed solely weak reactivity in a single case.
Cytoplasmic staining was current in all carcinomas and cell traces and with all antibodies and subsequently can’t be thought of particular; it was strongest with G175-405. Thus, we discovered antibody G175-405 to be probably the most particular, and monoclonals DCS-50 and ZJ11 the least particular for wild-type p16. Nevertheless, the previous tends to offer stronger cytoplasmic background staining. For tumor varieties wherein p16 mutations are unusual, the PharMingen polyclonal antibody could also be an appropriate various.
The specificity and patterns of staining in human cells and tissues of p16INK4a antibodies show variant antigen binding.
The validity of the identification and classification of human most cancers utilizing antibodies to detect biomarker proteins relies upon upon antibody specificity. Antibodies that bind to the tumour-suppressor protein p16INK4a are broadly used for most cancers analysis and analysis. On this examine we examined the specificity of 4 commercially obtainable anti-p16INK4a antibodies in 4 immunological purposes.
The antibodies H-156 and JC8 detected the identical 16 kDa protein in western blot and immunoprecipitation assessments, whereas the antibody F-12 didn’t detect any protein in western blot evaluation or seize a protein that might be recognised by the H-156 antibody.
In immunocytochemistry assessments, the antibodies JC8 and H-156 detected a predominately cytoplasmic localised antigen, whose sign was depleted in p16INK4a siRNA experiments. F-12, in distinction, detected a predominately nuclear situated antigen and there was no noticeable discount on this sign after siRNA knockdown. Moreover in immunohistochemistry assessments, F-12 generated a special sample of staining in comparison with the JC8 and E6H4 antibodies.
These outcomes show that three out of 4 commercially obtainable p16INK4a antibodies are particular to, and point out a primarily cytoplasmic localisation for, the p16INK4a protein. The F-12 antibody, which has been broadly utilized in earlier research, gave totally different outcomes to the opposite antibodies and didn’t show specificity to human p16INK4a. This work emphasizes the significance of the validation of economic antibodies, apart to the beforehand reported use, for the complete verification of immunoreaction specificity.
Skinny HSIL of the Cervix: Detecting a Variant of Excessive-grade Squamous Intraepithelial Lesions With a p16INK4a Antibody.
The WHO defines skinny high-grade squamous intraepithelial lesions (HSIL) as a high-grade intraepithelial lesion of the cervix that’s often ≤9 cells thick. These lesions often develop in early metaplastic squamous epithelium with out anteceding low-grade squamous intraepithelial lesions (LSIL). The prevalence of skinny HSIL is just not effectively documented.
We evaluated totally different traits of skinny HSIL at time of remedy. We studied 25 formalin-fixed and paraffin-embedded conization specimens processed as step-serial sections. HSIL≤9 cells thick had been labeled as skinny HSIL. HSIL≥10 cells thick had been labeled as traditional HSIL. Immunohistochemical p16 staining was used to substantiate lesions of skinny HSIL.
General, 19 (76%) specimens contained each skinny HSIL and traditional HSIL, 4 (16%) contained skinny HSIL solely, 1 (4%) contained classic-type HSIL solely, and 1 (4%) contained skinny HSIL and LSIL. Skinny HSILs developed in each the columnar floor epithelium and deep cervical glandular epithelium.
Most skinny HSILs had been 5 cells thick. All HSILs (skinny and traditional) had been situated contained in the transformation zone and had a median horizontal extension of eight mm (vary, 0.Three to 21 mm). Our findings recommend that skinny HSILs are frequent findings, that they coexist with traditional HSIL, and ideally come up within the uncovered components of the transformation zone together with the glandular crypts.
An antibody to p16INK4A acknowledges a modified type of galectin-3.
Galectin-Three is a carbohydrate binding protein concerned in a number of processes together with cell-cycle regulation and apoptosis. The power of galectin-Three to guard cells from apoptosis depends upon a area of the protein often known as a BH-1 area for its homology to the anti-apoptotic protein Bcl-2. Right here, we present {that a} monoclonal antibody (MAb) to the human tumor suppressor protein p16INK4A acknowledges a post-translationally modified type of human galectin-3.
The modified type is detectable in solely a subset of cell varieties expressing galectin-3, indicating that the modification is cell-type-specific. Though there’s little amino acid sequence homology between p16INK4a and galectin-3, we present by epitope mapping that the modification straight impacts the construction of galectin-3’s BH-1 area. Elucidation of the character of this modification would possibly present additional perception into galectin-Three operate.
Using recombinant pseudotype virus-like particles harbouring inserted goal antigen to generate antibodies towards mobile marker p16INK4A.
Protein engineering gives a possibility to generate new immunogens with desired options. Beforehand, we’ve got demonstrated that hamster polyomavirus main capsid protein VP1-derived virus-like particles (VLPs) are extremely immunogenic and could be employed for the insertion of international epitopes at sure surface-exposed positions.
Within the present examine, we’ve got designed pseudotype VLPs consisting of an intact VP1 protein and VP2 protein fused with the goal antigen–cellular marker p16(INK4A)–at its N terminus. Each proteins coexpressed in yeast had been self-assembled to pseudotype VLPs harbouring the inserted antigen on the floor. The pseudotype VLPs had been used for era of antibodies towards p16(INK4A) that represents a possible biomarker for cells reworked by high-risk human papillomavirus (HPV).
The pseudotype VLPs induced in immunized mice a robust immune response towards the goal antigen. The antisera raised towards pseudotype VLPs confirmed particular immunostaining of p16(INK4A) protein in malignant cervical tissue. Spleen cells of the immunized mice had been used to generate monoclonal antibodies towards p16(INK4A) protein.
p16INK4A Antibody |
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| MBS9435662-5x01mL | MyBiosource | 5x0.1mL | EUR 1810 |
CDKN2A/p16INK4a Antibody |
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| AF5484 | Affbiotech | 200ul | EUR 420 |
CDKN2A/p16INK4a Antibody |
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| AF5484-100ul | Affinity Biosciences | 100ul | EUR 168 |
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Description: WB,IF/ICC,ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| AF5484-200ul | Affinity Biosciences | 200ul | EUR 210 |
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Description: WB,IF/ICC,ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| AF0228 | Affbiotech | 200ul | EUR 420 |
CDKN2A/p16INK4a Antibody |
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| AF0228-100ul | Affinity Biosciences | 100ul | EUR 168 |
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Description: WB,IHC,IF/ICC,ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| AF0228-200ul | Affinity Biosciences | 200ul | EUR 210 |
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Description: WB,IHC,IF/ICC,ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| AF6667 | Affbiotech | 100ul | EUR 420 |
CDKN2A/p16INK4a Antibody |
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| AF6667-100ul | Affinity Biosciences | 100ul | EUR 168 |
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Description: ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| AF6667-200ul | Affinity Biosciences | 200ul | EUR 210 |
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Description: ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| AF6898 | Affbiotech | 100ul | EUR 420 |
CDKN2A/p16INK4a Antibody |
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| AF6898-100ul | Affinity Biosciences | 100ul | EUR 168 |
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Description: ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| AF6898-200ul | Affinity Biosciences | 200ul | EUR 210 |
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Description: ELISA(peptide) |
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CDKN2A/p16INK4a Antibody |
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| MBS9613919-01mL | MyBiosource | 0.1mL | EUR 260 |
CDKN2A/p16INK4a Antibody |
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| MBS9613919-02mL | MyBiosource | 0.2mL | EUR 305 |
CDKN2A/p16INK4a Antibody |
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| MBS9613919-5x02mL | MyBiosource | 5x0.2mL | EUR 1220 |
CDKN2A/p16INK4a Antibody |
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| MBS9613688-01mL | MyBiosource | 0.1mL | EUR 260 |
CDKN2A/p16INK4a Antibody |
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| MBS9613688-02mL | MyBiosource | 0.2mL | EUR 305 |
CDKN2A/p16INK4a Antibody |
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| MBS9613688-5x02mL | MyBiosource | 5x0.2mL | EUR 1220 |
P16INK4A Antibody (IHC Gold) |
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| E36PA116 | EnoGene | 100ul | EUR 225 |
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Description: Available in various conjugation types. |
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P16INK4A Antibody (IHC Gold) |
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| MBS8580171-01mL | MyBiosource | 0.1mL | EUR 305 |
P16INK4A Antibody (IHC Gold) |
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| MBS8580171-01mLAF405L | MyBiosource | 0.1mL(AF405L) | EUR 465 |
The specificity of antibodies was confirmed by the immunostaining of HPV-transformed cells. In conclusion, the present examine demonstrates the potential of pseudotype VLPs with inserted goal antigen as a brand new kind of immunogens to generate antibodies of excessive diagnostic worth.
