Heat shock protein (Hsp)90 is frequently over-expressed in pancreas carcinomas and protects a number of cell-cycle regulators such as the proto-oncogene Cdc25A.
Accordingly, TFF1 expression is absent in normal human colon crypts but is induced in correlation with Cdc25a and b transcript levels and tumor grade in familial and sporadic colon adenomas and carcinomas.
The cdc25B2 splicing variant was detected in 27 carcinomas (79%) but only in 9 normal samples (26%) and was associated with the grade of the differentiation of the tumors. cdc25A mRNA was overexpressed in four tumors (12%) and cdc25C1 mRNA was overexpressed in nine tumors (26%).
The expression levels of CDC25B were generally higher than those of CDC25A and C. Of the 40 gastric carcinomas, 70% of the tumors expressed CDC25B mRNA at higher levels than the corresponding normal mucosas, while 38% overexpressed CDC25A mRNA.