Detection of CD44 splice variants in formalin‐fixed, paraffin‐embedded specimens of human skin cancer

The standard form of CD44 (CD44s) and CD44 isoforms, containing sequences encoded by one or several of 10 different variant CD44 exons (v1‐v10), are thought to play a crucial role in the growth and metastasis of certain human tumors. Recently, monoclonal antibodies (mAbs) directed against all CD44 isoforms (panCD44), or against epitopes encoded by specific variant exons (CD44v) have been developed, which unfortunately only stain cryopreserved tissues. We wished to develop a technique to unmask chemically CD44s and CD44v epitopes in paraffin‐embedded specimens of human skin cancers, so that they would be accessible for these mAbs. To address this issue, CD44s and CD44v expression was compared in cryopreserved and in formalin‐fixed, paraffin‐embedded biopsies obtained from the same basal cell carcinomas (BCC), squamous cell carcinomas (SCC), primary malignant melanomas (PMM) and metastatic malignant melanomas (MMM). Formalin‐fixed tumors were de‐paraffinized and treated briefly with an antigen retrieval fluid (TUF™) at 95°C or left untreated. In untreated paraffin‐embedded tissues, no CD44s or CD44v staining was detected. In contrast, in antigen retrieval fluid‐treated biopsies CD44s and CD44v expression was identical to that in cryopreserved specimens of the same tumor with the exception of mAbs detecting v7/8 and v10. We conclude that antigen retrieval unmasks certain epitopes in formalin‐fixed, paraffin‐embedded tissues, thus facilitating future research on the relevance of CD44s and CD44v expression for human skin carcinogenesis.

[1]  P. Herrlich,et al.  Expression of CD44 isoforms in human skin cancer. , 1996, European journal of cancer.

[2]  A. Ariza,et al.  CD44 and melanocytic tumors: a possible role for standard CD44 in the epidermotropic spread of melanoma , 1996, Journal of cutaneous pathology.

[3]  B. Haynes,et al.  Distribution of CD44 variant isoforms in human skin: differential expression in components of benign and malignant epithelia , 1995, Journal of cutaneous pathology.

[4]  E. Danen,et al.  Expression of cd44 splice variants in human cutaneous melanoma and melanoma cell lines is related to tumor progression and metastatic potential , 1995, International journal of cancer.

[5]  E. Danen,et al.  Glycoconjugate profile and cd44 expression in human melanoma cell lines with different metastatic capacity , 1995, International journal of cancer.

[6]  K. Bennett,et al.  CD44 isoforms containing exon V3 are responsible for the presentation of heparin-binding growth factor , 1995, The Journal of cell biology.

[7]  M. Furue,et al.  CD44 Expression in Normal Human Skin and Skin Tumors , 1995, The Journal of dermatology.

[8]  J. Sleeman,et al.  The role of CD44 splice variants in human metastatic cancer. , 1995, Ciba Foundation symposium.

[9]  T. Ryken,et al.  Craniocervical intradural neurenteric cysts. , 1995, Pediatric neurosurgery.

[10]  P. Herrlich,et al.  Surface protein expression and messenger RNA-splicing analysis of CD44 in uterine cervical cancer and normal cervical epithelium. , 1994, Cancer research.

[11]  A. Bateman,et al.  immunocytochemistry: a study of 80 antibodies , 2022 .

[12]  R. Cote,et al.  Strategies for improving the immunohistochemical staining of various intranuclear prognostic markers in formalin-paraffin sections: androgen receptor, estrogen receptor, progesterone receptor, p53 protein, proliferating cell nuclear antigen, and Ki-67 antigen revealed by antigen retrieval techniques , 1994, Human pathology.

[13]  P. Hersey,et al.  Immunohistological Examination Of The Relationship Between Metastatic Potential And Expression Of Adhesion Molecules And ‘Selectins’ On Melanoma Cells , 1994, Pathology.

[14]  F M van den Berg,et al.  Expression of CD44 variant proteins in human colorectal cancer is related to tumor progression. , 1993, Cancer research.

[15]  Johannes Gerdes,et al.  Antigen unmasking on formalin‐fixed, paraffin‐embedded tissue sections , 1993, The Journal of pathology.

[16]  P. Herrlich,et al.  CD44 splice variants: metastases meet lymphocytes. , 1993, Immunology today.

[17]  B. Giannotti,et al.  Adhesion molecule profile and malignancy of melanocytic lesions. , 1993, Melanoma research.

[18]  A. Feller,et al.  Constant detection of surface and cytoplasmic immunoglobulin heavy and light chain expression in formalin‐fixed and paraffin‐embedded material , 1993, The Journal of pathology.

[19]  P. Herrlich,et al.  Activated human lymphocytes and aggressive non-Hodgkin's lymphomas express a homologue of the rat metastasis-associated variant of CD44 , 1993, The Journal of experimental medicine.

[20]  P. Herrlich,et al.  Splicing choice from ten variant exons establishes CD44 variability. , 1993, Nucleic acids research.

[21]  P. Herrlich,et al.  A human homologue of the rat metastasis-associated variant of CD44 is expressed in colorectal carcinomas and adenomatous polyps , 1993, The Journal of cell biology.

[22]  J. Sleeman,et al.  Cd44 and Splice Variants of Cd44 in Normal Differentiation and Tumor Progression , 1993 .

[23]  J. Bell,et al.  Genomic structure of DNA encoding the lymphocyte homing receptor CD44 reveals at least 12 alternatively spliced exons. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[24]  D. Tarin,et al.  Significance of CD44 gene products for cancer diagnosis and disease evaluation , 1992, The Lancet.

[25]  M. Key,et al.  Antigen retrieval in formalin-fixed, paraffin-embedded tissues: an enhancement method for immunohistochemical staining based on microwave oven heating of tissue sections. , 1991, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[26]  Martin Hofmann,et al.  A new variant of glycoprotein CD44 confers metastatic potential to rat carcinoma cells , 1991, Cell.