Chapter 18
Southwestern Histochemistry
KO KOMUT A, T AKASHI KANEMA TSU AND T AKEHIKO KOJI
Introduction
Abnormal expression of oncogenes or proto-oncogenes are frequently related with cancer development. The epidermal growth
factor receptor (EGFR) gene has been found to be amplified and/
or expressed at high levels in various types of tumor cells including A431 human epidermoid carcinoma cells [1,2,3]. Although
the over-production of EGFR protein generally correlates with
an elevated level of its mRNA, it does not always accompany
EGFR gene amplification [4,S].Therefore, to understand the abnormal nature of cancer growth, the analysis of their gene expression at the transcriptional level as well as the transcript level
is. required.
The method, named southwestern histochemistry, may enable us to analyze the expression of transcription regulatory factors as specific DNA binding proteins at individual cell level.
Principle of Southwestern histochemistry
The principle of Southwestern histochemistry is almost the same
as with Southwestern analysis. We synthesized the set of ( + ) and
(-) oligo-DNAs consisted of specific resposive element on an
automated DNA synthesizer. These synthesized oligo-DNAs
were purified and labeled. The ( + ) and (- ) strands of each synthesized oligo-DNAs were mixed, denatured and annealed. We reCorrespondence to Ko Komuta, Takashi Kanematsu, Nagasaki University
School of Medicine, Department of Surgery II, 1-12-4, Sakamoto, Nagasaki,
852, Japan; Takehiko Koji, Nagasaki University School of Medicine, Department of Histology and Cell Biology, 1-12-4, Sakamoto, Nagasaki, 852, Japan
Southwestern Histochemistry
KO KOMUT A, T AKASHI KANEMA TSU AND T AKEHIKO KOJI
Introduction
Abnormal expression of oncogenes or proto-oncogenes are frequently related with cancer development. The epidermal growth
factor receptor (EGFR) gene has been found to be amplified and/
or expressed at high levels in various types of tumor cells including A431 human epidermoid carcinoma cells [1,2,3]. Although
the over-production of EGFR protein generally correlates with
an elevated level of its mRNA, it does not always accompany
EGFR gene amplification [4,S].Therefore, to understand the abnormal nature of cancer growth, the analysis of their gene expression at the transcriptional level as well as the transcript level
is. required.
The method, named southwestern histochemistry, may enable us to analyze the expression of transcription regulatory factors as specific DNA binding proteins at individual cell level.
Principle of Southwestern histochemistry
The principle of Southwestern histochemistry is almost the same
as with Southwestern analysis. We synthesized the set of ( + ) and
(-) oligo-DNAs consisted of specific resposive element on an
automated DNA synthesizer. These synthesized oligo-DNAs
were purified and labeled. The ( + ) and (- ) strands of each synthesized oligo-DNAs were mixed, denatured and annealed. We reCorrespondence to Ko Komuta, Takashi Kanematsu, Nagasaki University
School of Medicine, Department of Surgery II, 1-12-4, Sakamoto, Nagasaki,
852, Japan; Takehiko Koji, Nagasaki University School of Medicine, Department of Histology and Cell Biology, 1-12-4, Sakamoto, Nagasaki, 852, Japan