Tumor cells and lung cells both express the pyruvate kinase isoenzyme type M2.

However, the M2-PK isoenzyme found in normal lung tissues is always tetrameric whereas the M2-PK isoenzyme found in tumor cells is mainly dimeric.

The dimeric form of M2-PK is termed Tumor M2-PK.

Differentation between lung M2-PK and Tumor M2-PK

Staining of a moderately to poorly differentiated,
non-small cell carcinoma of the left lung lobe
with monoclonal antibodies which specifically recognize
the dimeric form of M2-PK (Tumor M2-PK)
 

Tumor cells show a clear cytoplasmatic Tumor M2-PK staining. Non-malignant cells are not stained with the Tumor M2-PK specific antibody.

Enlargement with intravasal tumor cells
 

The intravascular Tumor M2-PK staining indicates vascular dissemination of the tumor.
From: Joachim Schneider, Shaker-Verlag Aachen (2003), pp 1-202, ISBN 3-8322-1381-3.

Vmax activities of pyruvate kinase
in homogenates
of normal lung and lung tumor tissues

Vmax activities were measured spectrophotometrically according to the following
reaction:

Tumor M2-PK concentrations
in homogenatesof normal lung and lung tumor tissues

In solid lung tumors pyruvate kinase activities as well as the amount of Tumor M2-PK (dimeric form) increase.

Vmax activities and Tumor M2-PK concentrations in lung control and lung tumor homogenates are part of the doctoral thesis of Anette Beitz, Veterinary Faculty, University of Giessen.
 

Tumor M2-PK concentrations
in EDTA plasma samples
from patients with lung tumors
Correlation between Tumor M2-PK values and staging
 

From: J. Schneider (Tumor Markers, AACC Press, Washington, Chapter 47: 471-475).
 

Tumor M2-PK concentrations
in EDTA-plasma samples
Follow-up study of a patient with an adenocarcimoma of the lung
 

From: Schneider et al.: Anticancer Res. (2000), 20: 5053-5058.
 

Tumor M2-PK concentrations
in EDTA-plasma samples
Follow-up study of a patient suffering from small cell carcinoma
 

T: radiological tumor size in X-ray
From: Schneider et al.: Anticancer Res. (2002), 22: 311-318.

Tumor M2-PK measurements in EDTA-plasma samples : Joachim Schneider

Tumor M2-PK concentrations were measured with a sandwich ELISA from
ScheBo Biotech AG, Giessen, Germany.

References

Tumor M2-PK: clinical relevance for metabolic profiling of tumors

Metabolic tools for tumor diagnosis

Pyruvate kinase isoenzymes: M2-PK