Comparison of immunohistochemistry and RT‐PCR for detection of CD44v‐expression, a new prognostic factor in human breast cancer

Abstract

In different human tumors, splice variants of the surface glycoprotein CD44 (CD44v) are correlated with advanced stages of tumor growth and metastatic potential. In breast cancer and colon cancer, expression of epitopes encoded by exon v6 on primary tumors is an independent prognostic factor for poor patient survival. Two different screening methods for the detection of CD44 variants in tumors have been applied: immunohistochemistry (IHC) and semi-quantitative reverse transcription PCR (RT-PCR). In this study, we have compared the predictive capacity and the applicability of both approaches, using 31 human breast-tissue specimens (normal and neoplastic). IHC reveals lack of expression of CD44v on normal ductal epithelial cells but strong expression on myoepithelial cells. The majority of tumors express CD44 epitopes encoded by several variant exons. RT-PCR detects splice variants in normal epithelium, probably derived from RNA expressed in the myoepithelium. In tumors, RT-PCR reveals expression of a wide range of splice variants, including new ones that are not detected in normal breast tissue, e.g. ones that contain all variant exons. The conclusion of this comparison is that IHC is the better method for breast-tumor sample screening but that the increased sensitivity of RT-PCR can help to distinguish CD44v-positive from CD44v-negative tumors in cases where only a few tumor cells express variants or where epitopes are masked.

Alternatively spliced variants of the cell adhesion molecule CD44 and tumour progression in colorectal cancer

“…Several studies have suggested an important biological role for CD44 in tumour progression and metastasis, and the potential for the use of CD44 variant expression as a clinicopathological marker of disease progression in colorectal (Wielenga et al, 1993), breast (Dall et al, 1995), pancreatic (Takada et al, 1994) and gastric cancers . The finding of a relationship between CD44 variant expression and colorectal cancer progression has not been uniform however (see Finke et al, 1995) (Mulder et al, 1995) (92% vs 67%).…”

CD44v3 and v6 variant isoform expression correlates with poor prognosis in early-stage vulvar cancer

“…However. in recent studies an excellent correlation between the detection of CD44 isoforms by immrunohistochemistrs and reverse transcription PCR was reported (Dall et al 1995 (Tempfer et al 1996a. b).…”

“…breast. cervical and colorectal cancer (Mulder et al 1994: Kainz et al 1995: Kauffmann et al 1995 al (1996) have reported PFSR to be strongly correlated with high CD44 expression. Therefore.…”

“…colorectal cancer and gastrointestinal lvmphoma (Joensuu et al 1993: Mulder et al 1994: Kauffmann et al 1995 …”

Inhibition of MT-450 rat mammary tumour growth by antibodies recognising subtypes of blood group antigen B

“…Rat tissues were ®xed in 4% paraformaldehyde then embedded in para n wax. Five mm sections were immunostained as described (Dall et al, 1995). For immuno¯uorescence studies, adherent cells were grown on eight well chamber slides (Nunc) and suspension cultures were a xed to silane treated slides using a Cytospin centrifuge (Shandon Southern).…”